v1.10.1

changelog.md

@@ -1,5 +1,97 @@
 # Changelog
 
+## 2026-03-29 - 1.10.1 - fix(test, docs, scripts)
+correct test command verbosity, shorten load test timings, and document forwarding modes
+
+- Fixes the test script by removing the duplicated verbose flag in package.json.
+- Reduces load test delays and burst sizes to keep keepalive and connection tests faster and more stable.
+- Updates the README to describe forwardingMode options, userspace NAT support, and related configuration examples.
+
+## 2026-03-29 - 1.10.0 - feat(rust-server, rust-client, ts-interfaces)
+add configurable packet forwarding with TUN and userspace NAT modes
+
+- introduce forwardingMode options for client and server configuration interfaces
+- add server-side forwarding engines for kernel TUN, userspace socket NAT, and testing mode
+- add a smoltcp-based userspace NAT implementation for packet forwarding without root-only TUN routing
+- enable client-side TUN forwarding support with route setup, packet I/O, and cleanup
+- centralize raw packet destination IP extraction in tunnel utilities for shared routing logic
+- update test command timeout and logging flags
+
+## 2026-03-29 - 1.9.0 - feat(server)
+add PROXY protocol v2 support for real client IP handling and connection ACLs
+
+- add PROXY protocol v2 parsing for WebSocket connections, including IPv4/IPv6 support, LOCAL command handling, and header read timeout protection
+- apply server-level connection IP block lists before the Noise handshake and enforce per-client source IP allow/block lists using the resolved remote address
+- expose proxy protocol configuration and remote client address fields in Rust and TypeScript interfaces, and document reverse-proxy usage in the README
+
+## 2026-03-29 - 1.8.0 - feat(auth,client-registry)
+add Noise IK client authentication with managed client registry and per-client ACL controls
+
+- switch the native tunnel handshake from Noise NK to Noise IK and require client keypairs in client configuration
+- add server-side client registry management APIs for creating, updating, disabling, rotating, listing, and exporting client configs
+- enforce client authorization from the registry during handshake and expose authenticated client metadata in server client info
+- introduce per-client security policies with source/destination ACLs and per-client rate limit settings
+- add Rust ACL matching support for exact IPs, CIDR ranges, wildcards, and IP ranges with test coverage
+
+## 2026-03-29 - 1.7.0 - feat(rust-tests)
+add end-to-end WireGuard UDP integration tests and align TypeScript build configuration
+
+- Add userspace Rust end-to-end tests that validate WireGuard handshake, encryption, peer isolation, and preshared-key data exchange over real UDP sockets.
+- Update the TypeScript build setup by removing the allowimplicitany build flag and explicitly including Node types in tsconfig.
+- Refresh development toolchain versions to support the updated test and build workflow.
+
+## 2026-03-29 - 1.6.0 - feat(readme)
+document WireGuard transport support, configuration, and usage examples
+
+- Expand the README from dual-transport to triple-transport support by adding WireGuard alongside WebSocket and QUIC
+- Add client and server WireGuard examples, including live peer management and .conf generation with WgConfigGenerator
+- Document new WireGuard-related API methods, config fields, transport modes, and security model details
+
+## 2026-03-29 - 1.5.0 - feat(wireguard)
+add WireGuard transport support with management APIs and config generation
+
+- add Rust WireGuard module integration using boringtun and route management through client/server management handlers
+- extend TypeScript client and server configuration schemas with WireGuard-specific options and validation
+- add server-side WireGuard peer management commands including keypair generation, peer add/remove, and peer listing
+- export a WireGuard config generator for producing client and server .conf files
+- add WireGuard-focused test coverage for config validation and config generation
+
+## 2026-03-21 - 1.4.1 - fix(readme)
+preserve markdown line breaks in feature list
+
+- Adds trailing spaces to the README feature list so each highlighted capability renders on its own line.
+
+## 2026-03-19 - 1.4.0 - feat(vpn transport)
+add QUIC transport support with auto fallback to WebSocket
+
+- introduces a transport abstraction in the Rust daemon so client and server can operate over WebSocket or QUIC
+- adds dual-mode server configuration with websocket, quic, and both transport modes plus QUIC idle timeout and listen address options
+- adds client transport selection with auto mode that attempts QUIC first and falls back to WebSocket
+- adds QUIC certificate hash pinning support and required Rust dependencies for QUIC and TLS
+- updates TypeScript interfaces, config validation, tests, and documentation to cover the new transport modes
+
+## 2026-03-17 - 1.3.0 - feat(tests,client)
+add flow control and load test coverage and honor configured keepalive intervals
+
+- Adds end-to-end node tests for client/server flow control, keepalive exchange, connection quality telemetry, rate limiting, concurrent clients, and disconnect tracking.
+- Adds load testing with throttled proxy scenarios to validate behavior under constrained bandwidth and repeated client churn.
+- Updates the Rust client to pass configured keepaliveIntervalSecs into the adaptive keepalive monitor instead of always using defaults.
+
+## 2026-03-15 - 1.2.0 - feat(readme)
+document QoS, telemetry, MTU, and rate limiting capabilities in the README
+
+- Expand the architecture and feature overview to cover adaptive keepalive, telemetry, QoS, rate limiting, and MTU handling
+- Update client and server examples to show new APIs such as getConnectionQuality(), getMtuInfo(), setClientRateLimit(), and getClientTelemetry()
+- Add TypeScript interface documentation for connection quality, MTU info, enriched client statistics, and per-client telemetry
+
+## 2026-03-15 - 1.1.0 - feat(rust-core)
+add adaptive keepalive telemetry, MTU handling, and per-client rate limiting APIs
+
+- adds adaptive keepalive monitoring with RTT, jitter, loss, and link health reporting to client statistics and management endpoints
+- introduces MTU overhead calculation and oversized-packet handling support, plus client MTU info APIs
+- adds token-bucket rate limiting with configurable default limits and server management commands to set, remove, and inspect per-client telemetry
+- extends TypeScript client and server interfaces with connection quality, MTU, and client telemetry methods
+
 ## 2026-02-27 - 1.0.3 - fix(build)
 add aarch64 linker configuration for cross-compilation
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@push.rocks/smartvpn",
-  "version": "1.0.3",
+  "version": "1.10.1",
   "private": false,
   "description": "A VPN solution with TypeScript control plane and Rust data plane daemon",
   "type": "module",
@@ -10,8 +10,9 @@
   "main": "dist_ts/index.js",
   "typings": "dist_ts/index.d.ts",
   "scripts": {
-    "build": "(tsbuild tsfolders --allowimplicitany) && (tsrust)",
+    "build": "(tsbuild tsfolders) && (tsrust)",
-    "test": "tstest test/ --verbose",
+    "test:before": "(tsrust)",
+    "test": "tstest test/ --verbose  --logfile --timeout 60",
     "buildDocs": "tsdoc"
   },
   "repository": {
@@ -28,15 +29,15 @@
   ],
   "license": "MIT",
   "dependencies": {
-    "@push.rocks/smartrust": "^1.3.0",
+    "@push.rocks/smartpath": "^6.0.0",
-    "@push.rocks/smartpath": "^5.0.18"
+    "@push.rocks/smartrust": "^1.3.2"
   },
   "devDependencies": {
-    "@git.zone/tsbuild": "^2.2.12",
+    "@git.zone/tsbuild": "^4.4.0",
-    "@git.zone/tsrun": "^1.3.3",
+    "@git.zone/tsrun": "^2.0.2",
-    "@git.zone/tstest": "^1.0.96",
+    "@git.zone/tsrust": "^1.3.2",
-    "@git.zone/tsrust": "^1.0.29",
+    "@git.zone/tstest": "^3.6.3",
-    "@types/node": "^22.0.0"
+    "@types/node": "^25.5.0"
   },
   "files": [
     "ts/**/*",

readme.md

@@ -1,392 +1,420 @@
 # @push.rocks/smartvpn
 
-A high-performance VPN solution with a **TypeScript control plane** and a **Rust data plane daemon**. Manage VPN connections with clean, typed APIs while all networking heavy lifting — encryption, tunneling, packet forwarding — runs at native speed in Rust.
+A high-performance VPN solution with a **TypeScript control plane** and a **Rust data plane daemon**. Enterprise-ready client authentication, triple transport support (WebSocket + QUIC + WireGuard), and a typed hub API for managing clients from code.
+
+🔐 **Noise IK** mutual authentication — per-client X25519 keypairs, server-side registry
+🚀 **Triple transport**: WebSocket (Cloudflare-friendly), raw **QUIC** (datagrams), and **WireGuard** (standard protocol)
+🛡️ **ACL engine** — deny-overrides-allow IP filtering, aligned with SmartProxy conventions
+🔀 **PROXY protocol v2** — real client IPs behind reverse proxies (HAProxy, SmartProxy, Cloudflare Spectrum)
+📊 **Adaptive QoS**: per-client rate limiting, priority queues, connection quality tracking
+🔄 **Hub API**: one `createClient()` call generates keys, assigns IP, returns both SmartVPN + WireGuard configs
+📡 **Real-time telemetry**: RTT, jitter, loss ratio, link health — all via typed APIs
+🌐 **Flexible forwarding**: TUN device (kernel), userspace NAT (no root), or testing mode
 
 ## Issue Reporting and Security
 
 For reporting bugs, issues, or security vulnerabilities, please visit [community.foss.global/](https://community.foss.global/). This is the central community hub for all issue reporting. Developers who sign and comply with our contribution agreement and go through identification can also get a [code.foss.global/](https://code.foss.global/) account to submit Pull Requests directly.
 
-## Install
+## Install 📦
 
 ```bash
-npm install @push.rocks/smartvpn
-# or
 pnpm install @push.rocks/smartvpn
+# or
+npm install @push.rocks/smartvpn
 ```
 
-## 🏗️ Architecture
+The package ships with pre-compiled Rust binaries for **linux/amd64** and **linux/arm64**. No Rust toolchain required at runtime.
+
+## Architecture 🏗️
 
 ```
-TypeScript (control plane)              Rust (data plane)
+┌──────────────────────────────┐     JSON-lines IPC     ┌───────────────────────────────┐
-┌──────────────────────────┐            ┌───────────────────────────────┐
+│    TypeScript Control Plane  │ ◄─────────────────────► │     Rust Data Plane Daemon    │
-│ VpnClient / VpnServer    │            │ smartvpn_daemon                │
+│                              │   stdio  or  Unix sock  │                               │
-│   └─ VpnBridge           │──stdio/──▶ │  ├─ management (JSON IPC)     │
+│  VpnServer / VpnClient      │                          │  Noise IK handshake           │
-│      └─ RustBridge       │  socket    │  ├─ transport (WebSocket/TLS) │
+│  Typed IPC commands          │                          │  XChaCha20-Poly1305           │
-│         (smartrust)      │            │  ├─ crypto (Noise NK + XCha)  │
+│  Config validation           │                          │  WS + QUIC + WireGuard        │
-└──────────────────────────┘            │  ├─ codec (binary framing)    │
+│  Hub: client management      │                          │  TUN device, IP pool, NAT     │
-                                        │  ├─ keepalive (app-level)     │
+│  WireGuard .conf generation  │                          │  Rate limiting, ACLs, QoS     │
-                                        │  ├─ tunnel (TUN device)       │
+└──────────────────────────────┘                          └───────────────────────────────┘
-                                        │  ├─ network (NAT/IP pool)     │
-                                        │  └─ reconnect (backoff)       │
-                                        └───────────────────────────────┘
 ```
 
-**Key design decisions:**
+**Split-plane design** — TypeScript handles orchestration, config, and DX; Rust handles every hot-path byte with zero-copy async I/O (tokio, mimalloc).
 
-| Decision | Choice | Why |
+## Quick Start 🚀
-|----------|--------|-----|
-| Transport | WebSocket over HTTPS | Works through Cloudflare and other terminating proxies |
-| Encryption | Noise NK + XChaCha20-Poly1305 | Strong forward secrecy, large nonce space (no counter needed) |
-| Keepalive | App-level (not WS pings) | Cloudflare drops WS ping frames; app-level pings survive |
-| IPC | JSON lines over stdio/Unix socket | `stdio` for dev, `socket` for production (daemon stays alive) |
-| Binary protocol | `[type:1B][length:4B][payload:NB]` | Minimal overhead, easy to parse at wire speed |
 
-## 🚀 Quick Start
+### 1. Start a VPN Server (Hub)
-
-### VPN Client
-
-```typescript
-import { VpnClient } from '@push.rocks/smartvpn';
-
-// Development: spawn the Rust daemon as a child process
-const client = new VpnClient({
-  transport: { transport: 'stdio' },
-});
-
-// Start the daemon bridge
-await client.start();
-
-// Connect to a VPN server
-const { assignedIp } = await client.connect({
-  serverUrl: 'wss://vpn.example.com/tunnel',
-  serverPublicKey: 'BASE64_SERVER_PUBLIC_KEY',
-  dns: ['1.1.1.1', '8.8.8.8'],
-  mtu: 1420,
-  keepaliveIntervalSecs: 30,
-});
-
-console.log(`Connected! Assigned IP: ${assignedIp}`);
-
-// Check status
-const status = await client.getStatus();
-console.log(status); // { state: 'connected', assignedIp: '10.8.0.2', ... }
-
-// Get traffic stats
-const stats = await client.getStatistics();
-console.log(stats); // { bytesSent, bytesReceived, packetsSent, ... }
-
-// Disconnect
-await client.disconnect();
-client.stop();
-```
-
-### VPN Server
 
 ```typescript
 import { VpnServer } from '@push.rocks/smartvpn';
 
-const server = new VpnServer({
+const server = new VpnServer({ transport: { transport: 'stdio' } });
-  transport: { transport: 'stdio' },
-});
-
-// Start the daemon and the VPN server
 await server.start({
   listenAddr: '0.0.0.0:443',
-  privateKey: 'BASE64_PRIVATE_KEY',
+  privateKey: '<server-noise-private-key-base64>',
-  publicKey: 'BASE64_PUBLIC_KEY',
+  publicKey: '<server-noise-public-key-base64>',
   subnet: '10.8.0.0/24',
-  dns: ['1.1.1.1'],
+  transportMode: 'both', // WebSocket + QUIC simultaneously
-  mtu: 1420,
+  forwardingMode: 'tun', // 'tun' (kernel), 'socket' (userspace NAT), or 'testing'
   enableNat: true,
+  dns: ['1.1.1.1', '8.8.8.8'],
 });
-
-// Generate a Noise keypair
-const keypair = await server.generateKeypair();
-console.log(keypair); // { publicKey: '...', privateKey: '...' }
-
-// List connected clients
-const clients = await server.listClients();
-// [{ clientId, assignedIp, connectedSince, bytesSent, bytesReceived }]
-
-// Disconnect a specific client
-await server.disconnectClient('some-client-id');
-
-// Get server stats
-const stats = await server.getStatistics();
-// { bytesSent, bytesReceived, activeClients, totalConnections, ... }
-
-// Stop
-await server.stopServer();
-server.stop();
 ```
 
-### Production: Socket Transport
+### 2. Create a Client (One Call = Everything)
-
-In production, the daemon runs as a system service and you connect over a Unix socket:
 
 ```typescript
-const client = new VpnClient({
+const bundle = await server.createClient({
-  transport: {
+  clientId: 'alice-laptop',
-    transport: 'socket',
+  tags: ['engineering'],
-    socketPath: '/var/run/smartvpn.sock',
+  security: {
-    autoReconnect: true,
+    destinationAllowList: ['10.0.0.0/8'],        // can only reach internal network
-    reconnectBaseDelayMs: 100,
+    destinationBlockList: ['10.0.0.99'],           // except this host
-    reconnectMaxDelayMs: 30000,
+    rateLimit: { bytesPerSec: 10_000_000, burstBytes: 20_000_000 },
-    maxReconnectAttempts: 10,
   },
 });
 
-await client.start(); // connects to existing daemon (does not spawn)
+// bundle.smartvpnConfig  → typed IVpnClientConfig, ready to use
+// bundle.wireguardConfig → standard WireGuard .conf string
+// bundle.secrets         → { noisePrivateKey, wgPrivateKey } — shown ONCE
 ```
 
-When using socket transport, `client.stop()` closes the socket but **does not kill the daemon** — exactly what you want in production.
+### 3. Connect a Client
-
-## 📋 API Reference
-
-### `VpnClient`
-
-| Method | Returns | Description |
-|--------|---------|-------------|
-| `start()` | `Promise<boolean>` | Start the daemon bridge (spawn or connect) |
-| `connect(config?)` | `Promise<{ assignedIp }>` | Connect to VPN server |
-| `disconnect()` | `Promise<void>` | Disconnect from VPN |
-| `getStatus()` | `Promise<IVpnStatus>` | Current connection state |
-| `getStatistics()` | `Promise<IVpnStatistics>` | Traffic statistics |
-| `stop()` | `void` | Kill/close the daemon bridge |
-| `running` | `boolean` | Whether bridge is active |
-
-### `VpnServer`
-
-| Method | Returns | Description |
-|--------|---------|-------------|
-| `start(config?)` | `Promise<void>` | Start daemon + VPN server |
-| `stopServer()` | `Promise<void>` | Stop the VPN server |
-| `getStatus()` | `Promise<IVpnStatus>` | Server connection state |
-| `getStatistics()` | `Promise<IVpnServerStatistics>` | Server stats (includes client counts) |
-| `listClients()` | `Promise<IVpnClientInfo[]>` | Connected clients |
-| `disconnectClient(id)` | `Promise<void>` | Kick a client |
-| `generateKeypair()` | `Promise<IVpnKeypair>` | Generate Noise NK keypair |
-| `stop()` | `void` | Kill/close the daemon bridge |
-
-### `VpnConfig`
-
-Static utility class for config validation and file I/O:
 
 ```typescript
-import { VpnConfig } from '@push.rocks/smartvpn';
+import { VpnClient } from '@push.rocks/smartvpn';
 
-// Validate (throws on invalid)
+const client = new VpnClient({ transport: { transport: 'stdio' } });
-VpnConfig.validateClientConfig(config);
+await client.start();
-VpnConfig.validateServerConfig(config);
 
-// Load/save JSON configs
+const { assignedIp } = await client.connect(bundle.smartvpnConfig);
-const config = await VpnConfig.loadFromFile<IVpnClientConfig>('/etc/smartvpn/client.json');
+console.log(`Connected! VPN IP: ${assignedIp}`);
-await VpnConfig.saveToFile('/etc/smartvpn/client.json', config);
 ```
 
-### `VpnInstaller`
+## Features ✨
 
-Generate system service units for the daemon:
+### 🔐 Enterprise Authentication (Noise IK)
+
+Every client authenticates with a **Noise IK handshake** (`Noise_IK_25519_ChaChaPoly_BLAKE2s`). The server verifies the client's static public key against its registry — unauthorized clients are rejected before any data flows.
+
+- Per-client X25519 keypair generated server-side
+- Client registry with enable/disable, expiry, tags
+- Key rotation with `rotateClientKey()` — generates new keys, returns fresh config bundle, disconnects old session
+
+### 🌐 Triple Transport
+
+| Transport | Protocol | Best For |
+|-----------|----------|----------|
+| **WebSocket** | TLS over TCP | Firewall-friendly, Cloudflare compatible |
+| **QUIC** | UDP (via quinn) | Low latency, datagram support for IP packets |
+| **WireGuard** | UDP (via boringtun) | Standard WG clients (iOS, Android, wg-quick) |
+
+The server can run **all three simultaneously** with `transportMode: 'both'` (WS + QUIC) or `'wireguard'`. Clients auto-negotiate with `transport: 'auto'` (tries QUIC first, falls back to WS).
+
+### 🛡️ ACL Engine (SmartProxy-Aligned)
+
+Security policies per client, using the same `ipAllowList` / `ipBlockList` naming convention as `@push.rocks/smartproxy`:
+
+```typescript
+security: {
+  ipAllowList: ['192.168.1.0/24'],          // source IPs allowed to connect
+  ipBlockList: ['192.168.1.100'],            // deny overrides allow
+  destinationAllowList: ['10.0.0.0/8'],      // VPN destinations permitted
+  destinationBlockList: ['10.0.0.99'],        // deny overrides allow
+  maxConnections: 5,
+  rateLimit: { bytesPerSec: 1_000_000, burstBytes: 2_000_000 },
+}
+```
+
+Supports exact IPs, CIDR, wildcards (`192.168.1.*`), and ranges (`1.1.1.1-1.1.1.100`).
+
+### 🔀 PROXY Protocol v2
+
+When the VPN server sits behind a reverse proxy, enable PROXY protocol v2 to receive the **real client IP** instead of the proxy's address. This makes `ipAllowList` / `ipBlockList` ACLs work correctly through load balancers.
+
+```typescript
+await server.start({
+  // ... other config ...
+  proxyProtocol: true,                            // parse PP v2 headers on WS connections
+  connectionIpBlockList: ['198.51.100.0/24'],     // server-wide block list (pre-handshake)
+});
+```
+
+**Two-phase ACL with real IPs:**
+
+| Phase | When | What Happens |
+|-------|------|-------------|
+| **Pre-handshake** | After TCP accept | Server-level `connectionIpBlockList` rejects known-bad IPs — zero crypto cost |
+| **Post-handshake** | After Noise IK identifies client | Per-client `ipAllowList` / `ipBlockList` checked against real source IP |
+
+- Parses the PP v2 binary header from raw TCP before WebSocket upgrade
+- 5-second timeout protects against stalling attacks
+- LOCAL command (proxy health checks) handled gracefully
+- IPv4 and IPv6 addresses supported
+- `remoteAddr` field on `IVpnClientInfo` exposes the real client IP for monitoring
+- **Security**: must be `false` (default) when accepting direct connections — only enable behind a trusted proxy
+
+### 📦 Packet Forwarding Modes
+
+SmartVPN supports three forwarding modes, configurable per-server and per-client:
+
+| Mode | Flag | Description | Root Required |
+|------|------|-------------|---------------|
+| **TUN** | `'tun'` | Kernel TUN device — real packet forwarding with system routing | ✅ Yes |
+| **Userspace NAT** | `'socket'` | Userspace TCP/UDP proxy via `connect(2)` — no TUN, no root needed | ❌ No |
+| **Testing** | `'testing'` | Monitoring only — packets are counted but not forwarded | ❌ No |
+
+```typescript
+// Server with userspace NAT (no root required)
+await server.start({
+  // ...
+  forwardingMode: 'socket',
+  enableNat: true,
+});
+
+// Client with TUN device
+const { assignedIp } = await client.connect({
+  // ...
+  forwardingMode: 'tun',
+});
+```
+
+The userspace NAT mode extracts destination IP/port from IP packets, opens a real socket to the destination, and relays data — supporting both TCP streams and UDP datagrams without requiring `CAP_NET_ADMIN` or root privileges.
+
+### 📊 Telemetry & QoS
+
+- **Connection quality**: Smoothed RTT, jitter, min/max RTT, loss ratio, link health (`healthy` / `degraded` / `critical`)
+- **Adaptive keepalives**: Interval adjusts based on link health (60s → 30s → 10s)
+- **Per-client rate limiting**: Token bucket with configurable bytes/sec and burst
+- **Dead-peer detection**: 180s inactivity timeout
+- **MTU management**: Automatic overhead calculation (IP+TCP+WS+Noise = 79 bytes)
+
+### 🔄 Hub Client Management
+
+The server acts as a **hub** — one API to manage all clients:
+
+```typescript
+// Create (generates keys, assigns IP, returns config bundle)
+const bundle = await server.createClient({ clientId: 'bob-phone' });
+
+// Read
+const entry = await server.getClient('bob-phone');
+const all   = await server.listRegisteredClients();
+
+// Update (ACLs, tags, description, rate limits...)
+await server.updateClient('bob-phone', {
+  security: { destinationAllowList: ['0.0.0.0/0'] },
+  tags: ['mobile', 'field-ops'],
+});
+
+// Enable / Disable
+await server.disableClient('bob-phone'); // disconnects + blocks reconnection
+await server.enableClient('bob-phone');
+
+// Key rotation
+const newBundle = await server.rotateClientKey('bob-phone');
+
+// Export config (without secrets)
+const wgConf = await server.exportClientConfig('bob-phone', 'wireguard');
+
+// Remove
+await server.removeClient('bob-phone');
+```
+
+### 📝 WireGuard Config Generation
+
+Generate standard `.conf` files for any WireGuard client:
+
+```typescript
+import { WgConfigGenerator } from '@push.rocks/smartvpn';
+
+const conf = WgConfigGenerator.generateClientConfig({
+  privateKey: '<client-wg-private-key>',
+  address: '10.8.0.2/24',
+  dns: ['1.1.1.1'],
+  peer: {
+    publicKey: '<server-wg-public-key>',
+    endpoint: 'vpn.example.com:51820',
+    allowedIps: ['0.0.0.0/0'],
+    persistentKeepalive: 25,
+  },
+});
+// → standard WireGuard .conf compatible with wg-quick, iOS, Android
+```
+
+### 🖥️ System Service Installation
 
 ```typescript
 import { VpnInstaller } from '@push.rocks/smartvpn';
 
-// Auto-detect platform
+const unit = VpnInstaller.generateServiceUnit({
-const platform = VpnInstaller.detectPlatform(); // 'linux' | 'macos' | 'windows' | 'unknown'
-
-// Generate systemd unit (Linux)
-const unit = VpnInstaller.generateSystemdUnit({
-  binaryPath: '/usr/local/bin/smartvpn_daemon',
-  socketPath: '/var/run/smartvpn.sock',
-  mode: 'server',
-});
-// unit.content = full systemd .service file
-// unit.installPath = '/etc/systemd/system/smartvpn-server.service'
-
-// Generate launchd plist (macOS)
-const plist = VpnInstaller.generateLaunchdPlist({
-  binaryPath: '/usr/local/bin/smartvpn_daemon',
-  socketPath: '/var/run/smartvpn.sock',
-  mode: 'client',
-});
-
-// Auto-detect and generate
-const serviceUnit = VpnInstaller.generateServiceUnit({
-  binaryPath: '/usr/local/bin/smartvpn_daemon',
-  socketPath: '/var/run/smartvpn.sock',
   mode: 'server',
+  configPath: '/etc/smartvpn/server.json',
 });
+// unit.platform  → 'linux' | 'macos'
+// unit.content   → systemd unit file or launchd plist
+// unit.installPath → /etc/systemd/system/smartvpn-server.service
 ```
 
-### Events
+## API Reference 📖
 
-Both `VpnClient` and `VpnServer` extend `EventEmitter`:
+### Classes
+
+| Class | Description |
+|-------|-------------|
+| `VpnServer` | Manages the Rust daemon in server mode. Hub methods for client CRUD. |
+| `VpnClient` | Manages the Rust daemon in client mode. Connect, disconnect, telemetry. |
+| `VpnBridge<T>` | Low-level typed IPC bridge (stdio or Unix socket). |
+| `VpnConfig` | Static config validation and file I/O. |
+| `VpnInstaller` | Generates systemd/launchd service files. |
+| `WgConfigGenerator` | Generates standard WireGuard `.conf` files. |
+
+### Key Interfaces
+
+| Interface | Purpose |
+|-----------|---------|
+| `IVpnServerConfig` | Server configuration (listen addr, keys, subnet, transport mode, forwarding mode, clients, proxy protocol) |
+| `IVpnClientConfig` | Client configuration (server URL, keys, transport, forwarding mode, WG options) |
+| `IClientEntry` | Server-side client definition (ID, keys, security, priority, tags, expiry) |
+| `IClientSecurity` | Per-client ACLs and rate limits (SmartProxy-aligned naming) |
+| `IClientRateLimit` | Rate limiting config (bytesPerSec, burstBytes) |
+| `IClientConfigBundle` | Full config bundle returned by `createClient()` |
+| `IVpnClientInfo` | Connected client info (IP, stats, authenticated key, remote addr) |
+| `IVpnConnectionQuality` | RTT, jitter, loss ratio, link health |
+| `IVpnKeypair` | Base64-encoded public/private key pair |
+
+### Server IPC Commands
+
+| Command | Description |
+|---------|-------------|
+| `start` / `stop` | Start/stop the VPN listener |
+| `createClient` | Generate keys, assign IP, return config bundle |
+| `removeClient` / `getClient` / `listRegisteredClients` | Client registry CRUD |
+| `updateClient` / `enableClient` / `disableClient` | Modify client state |
+| `rotateClientKey` | Fresh keypairs + new config bundle |
+| `exportClientConfig` | Re-export as SmartVPN config or WireGuard `.conf` |
+| `listClients` / `disconnectClient` | Manage live connections |
+| `setClientRateLimit` / `removeClientRateLimit` | Runtime rate limit adjustments |
+| `getStatus` / `getStatistics` / `getClientTelemetry` | Monitoring |
+| `generateKeypair` / `generateWgKeypair` / `generateClientKeypair` | Key generation |
+| `addWgPeer` / `removeWgPeer` / `listWgPeers` | WireGuard peer management |
+
+### Client IPC Commands
+
+| Command | Description |
+|---------|-------------|
+| `connect` / `disconnect` | Manage the tunnel |
+| `getStatus` / `getStatistics` | Connection state and traffic stats |
+| `getConnectionQuality` | RTT, jitter, loss, link health |
+| `getMtuInfo` | MTU and overhead details |
+
+## Transport Modes 🔀
+
+### Server Configuration
 
 ```typescript
-client.on('status', (status) => { /* IVpnStatus */ });
+// WebSocket only
-client.on('error', (err) => { /* { message, code? } */ });
+{ transportMode: 'websocket', listenAddr: '0.0.0.0:443' }
-client.on('exit', ({ code, signal }) => { /* daemon exited */ });
-client.on('reconnected', () => { /* socket reconnected */ });
 
-server.on('client-connected', (info) => { /* IVpnClientInfo */ });
+// QUIC only
-server.on('client-disconnected', ({ clientId, reason }) => { /* ... */ });
+{ transportMode: 'quic', listenAddr: '0.0.0.0:443' }
+
+// Both (WS + QUIC on same or different ports)
+{ transportMode: 'both', listenAddr: '0.0.0.0:443', quicListenAddr: '0.0.0.0:4433' }
+
+// WireGuard
+{ transportMode: 'wireguard', wgListenPort: 51820, wgPeers: [...] }
 ```
 
-## 🔐 Security Model
+### Client Configuration
 
-The VPN uses a **Noise NK** handshake pattern:
+```typescript
+// Auto (tries QUIC first, falls back to WS)
+{ transport: 'auto', serverUrl: 'wss://vpn.example.com' }
 
-1. **NK** = client does **N**ot authenticate, but **K**nows the server's static public key
+// Explicit QUIC with certificate pinning
-2. The client generates an ephemeral keypair, performs `e, es` (Diffie-Hellman with server's static key)
+{ transport: 'quic', serverUrl: '1.2.3.4:4433', serverCertHash: '<sha256-base64>' }
-3. Server responds with `e, ee` (Diffie-Hellman with both ephemeral keys)
-4. Result: forward-secret transport keys derived from both DH operations
 
-Post-handshake, all IP packets are encrypted with **XChaCha20-Poly1305**:
+// WireGuard
-- 24-byte random nonces (no counter synchronization needed)
+{ transport: 'wireguard', wgPrivateKey: '...', wgEndpoint: 'vpn.example.com:51820', ... }
-- 16-byte authentication tags
-- Wire format: `[nonce:24B][ciphertext:var][tag:16B]`
-
-## 📦 Binary Protocol
-
-Inside the WebSocket tunnel, packets use a simple binary framing:
-
-```
-┌──────────┬──────────┬────────────────────┐
-│ Type (1B)│ Len (4B) │ Payload (variable) │
-└──────────┴──────────┴────────────────────┘
 ```
 
-| Type | Value | Description |
+## Cryptography 🔑
-|------|-------|-------------|
-| `HandshakeInit` | `0x01` | Client → Server handshake |
-| `HandshakeResp` | `0x02` | Server → Client handshake |
-| `IpPacket` | `0x10` | Encrypted IP packet |
-| `Keepalive` | `0x20` | App-level ping |
-| `KeepaliveAck` | `0x21` | App-level pong |
-| `SessionResume` | `0x30` | Resume a dropped session |
-| `SessionResumeOk` | `0x31` | Resume accepted |
-| `SessionResumeErr` | `0x32` | Resume rejected |
-| `Disconnect` | `0x3F` | Graceful disconnect |
 
-## 🛠️ Rust Daemon CLI
+| Layer | Algorithm | Purpose |
+|-------|-----------|---------|
+| **Handshake** | Noise IK (X25519 + ChaChaPoly + BLAKE2s) | Mutual authentication + key exchange |
+| **Transport** | Noise transport state (ChaChaPoly) | All post-handshake data encryption |
+| **Additional** | XChaCha20-Poly1305 | Extended nonce space for data-at-rest |
+| **WireGuard** | X25519 + ChaCha20-Poly1305 (via boringtun) | Standard WireGuard crypto |
 
-The Rust binary supports several modes:
+## Binary Protocol 📡
 
-```bash
+All frames use `[type:1B][length:4B][payload:NB]` with a 64KB max payload:
-# Development: stdio management (JSON lines on stdin/stdout)
-smartvpn_daemon --management --mode client
-smartvpn_daemon --management --mode server
 
-# Production: Unix socket management
+| Type | Hex | Direction | Description |
-smartvpn_daemon --management-socket /var/run/smartvpn.sock --mode server
+|------|-----|-----------|-------------|
+| HandshakeInit | `0x01` | Client → Server | Noise IK first message |
+| HandshakeResp | `0x02` | Server → Client | Noise IK response |
+| IpPacket | `0x10` | Bidirectional | Encrypted tunnel data |
+| Keepalive | `0x20` | Client → Server | App-level keepalive (not WS ping) |
+| KeepaliveAck | `0x21` | Server → Client | Keepalive response with RTT payload |
+| Disconnect | `0x3F` | Bidirectional | Graceful disconnect |
 
-# Generate a Noise keypair
+## Development 🛠️
-smartvpn_daemon --generate-keypair
-```
-
-## 🔧 Building from Source
 
 ```bash
 # Install dependencies
 pnpm install
 
-# Build TypeScript + cross-compile Rust
+# Build (TypeScript + Rust cross-compile)
 pnpm build
 
-# Build Rust only (debug)
+# Run all tests (79 TS + 132 Rust = 211 tests)
-cd rust && cargo build
+pnpm test
 
-# Run Rust tests
+# Run Rust tests directly
 cd rust && cargo test
 
-# Run TypeScript tests
+# Run a specific TS test
-pnpm test
+tstest test/test.flowcontrol.node.ts --verbose
 ```
 
-## TypeScript Interfaces
+### Project Structure
 
-<details>
-<summary>Click to expand full type definitions</summary>
-
-```typescript
-// Transport options
-type TVpnTransportOptions =
-  | { transport: 'stdio' }
-  | {
-      transport: 'socket';
-      socketPath: string;
-      autoReconnect?: boolean;
-      reconnectBaseDelayMs?: number;
-      reconnectMaxDelayMs?: number;
-      maxReconnectAttempts?: number;
-    };
-
-// Client config
-interface IVpnClientConfig {
-  serverUrl: string;          // e.g. 'wss://vpn.example.com/tunnel'
-  serverPublicKey: string;    // base64-encoded Noise static key
-  dns?: string[];
-  mtu?: number;               // default: 1420
-  keepaliveIntervalSecs?: number; // default: 30
-}
-
-// Server config
-interface IVpnServerConfig {
-  listenAddr: string;         // e.g. '0.0.0.0:443'
-  privateKey: string;         // base64 Noise static private key
-  publicKey: string;          // base64 Noise static public key
-  subnet: string;             // e.g. '10.8.0.0/24'
-  tlsCert?: string;
-  tlsKey?: string;
-  dns?: string[];
-  mtu?: number;
-  keepaliveIntervalSecs?: number;
-  enableNat?: boolean;
-}
-
-// Status
-type TVpnConnectionState = 'disconnected' | 'connecting' | 'handshaking'
-                         | 'connected' | 'reconnecting' | 'error';
-
-interface IVpnStatus {
-  state: TVpnConnectionState;
-  assignedIp?: string;
-  serverAddr?: string;
-  connectedSince?: string;
-  lastError?: string;
-}
-
-// Statistics
-interface IVpnStatistics {
-  bytesSent: number;
-  bytesReceived: number;
-  packetsSent: number;
-  packetsReceived: number;
-  keepalivesSent: number;
-  keepalivesReceived: number;
-  uptimeSeconds: number;
-}
-
-interface IVpnServerStatistics extends IVpnStatistics {
-  activeClients: number;
-  totalConnections: number;
-}
-
-interface IVpnClientInfo {
-  clientId: string;
-  assignedIp: string;
-  connectedSince: string;
-  bytesSent: number;
-  bytesReceived: number;
-}
-
-interface IVpnKeypair {
-  publicKey: string;
-  privateKey: string;
-}
 ```
-
+smartvpn/
-</details>
+├── ts/                         # TypeScript control plane
+│   ├── index.ts                # All exports
+│   ├── smartvpn.interfaces.ts  # Interfaces, types, IPC command maps
+│   ├── smartvpn.classes.vpnserver.ts
+│   ├── smartvpn.classes.vpnclient.ts
+│   ├── smartvpn.classes.vpnbridge.ts
+│   ├── smartvpn.classes.vpnconfig.ts
+│   ├── smartvpn.classes.vpninstaller.ts
+│   └── smartvpn.classes.wgconfig.ts
+├── rust/                       # Rust data plane daemon
+│   └── src/
+│       ├── main.rs             # CLI entry point
+│       ├── server.rs           # VPN server + hub methods
+│       ├── client.rs           # VPN client
+│       ├── crypto.rs           # Noise IK + XChaCha20
+│       ├── client_registry.rs  # Client database
+│       ├── acl.rs              # ACL engine
+│       ├── proxy_protocol.rs   # PROXY protocol v2 parser
+│       ├── management.rs       # JSON-lines IPC
+│       ├── transport.rs        # WebSocket transport
+│       ├── quic_transport.rs   # QUIC transport
+│       ├── wireguard.rs        # WireGuard (boringtun)
+│       ├── codec.rs            # Binary frame protocol
+│       ├── keepalive.rs        # Adaptive keepalives
+│       ├── ratelimit.rs        # Token bucket
+│       ├── userspace_nat.rs    # Userspace TCP/UDP NAT proxy
+│       └── ...                 # tunnel, network, telemetry, qos, mtu, reconnect
+├── test/                       # 9 test files (79 tests)
+├── dist_ts/                    # Compiled TypeScript
+└── dist_rust/                  # Cross-compiled binaries (linux amd64 + arm64)
+```
 
 ## License and Legal Information
 

readme.plan.md

@@ -0,0 +1,253 @@
+# PROXY Protocol v2 Support for SmartVPN WebSocket Transport
+
+## Context
+
+SmartVPN's WebSocket transport is designed to sit behind reverse proxies (Cloudflare, HAProxy, SmartProxy). The recently added ACL engine has `ipAllowList`/`ipBlockList` per client, but without PROXY protocol support the server only sees the proxy's IP — not the real client's. This makes source-IP ACLs useless behind a proxy.
+
+PROXY protocol v2 solves this by letting the proxy prepend a binary header with the real client IP/port before the WebSocket upgrade.
+
+---
+
+## Design
+
+### Two-Phase ACL with Real Client IP
+
+```
+TCP accept → Read PP v2 header → Extract real IP
+  │
+  ├─ Phase 1 (pre-handshake): Check server-level connectionIpBlockList → reject early
+  │
+  ├─ WebSocket upgrade → Noise IK handshake → Client identity known
+  │
+  └─ Phase 2 (post-handshake): Check per-client ipAllowList/ipBlockList → reject if denied
+```
+
+- **Phase 1**: Server-wide block list (`connectionIpBlockList` on `IVpnServerConfig`). Rejects before any crypto work. Protects server resources.
+- **Phase 2**: Per-client ACL from `IClientSecurity.ipAllowList`/`ipBlockList`. Applied after the Noise IK handshake identifies the client.
+
+### No New Dependencies
+
+PROXY protocol v2 is a fixed-format binary header (16-byte signature + variable address block). Manual parsing (~80 lines) follows the same pattern as `codec.rs`. No crate needed.
+
+### Scope: WebSocket Only
+
+- **WebSocket**: Needs PP v2 (sits behind reverse proxies)
+- **QUIC**: Direct UDP, just use `conn.remote_address()`
+- **WireGuard**: Direct UDP, uses boringtun peer tracking
+
+---
+
+## Implementation
+
+### Phase 1: New Rust module `proxy_protocol.rs`
+
+**New file: `rust/src/proxy_protocol.rs`**
+
+PP v2 binary format:
+```
+Bytes 0-11:   Signature  \x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A
+Byte 12:      Version (high nibble = 0x2) | Command (low nibble: 0x0=LOCAL, 0x1=PROXY)
+Byte 13:      Address family | Protocol (0x11 = IPv4/TCP, 0x21 = IPv6/TCP)
+Bytes 14-15:  Address data length (big-endian u16)
+Bytes 16+:    IPv4: 4 src_ip + 4 dst_ip + 2 src_port + 2 dst_port (12 bytes)
+              IPv6: 16 src_ip + 16 dst_ip + 2 src_port + 2 dst_port (36 bytes)
+```
+
+```rust
+pub struct ProxyHeader {
+    pub src_addr: SocketAddr,
+    pub dst_addr: SocketAddr,
+    pub is_local: bool,  // LOCAL command = health check probe
+}
+
+/// Read and parse a PROXY protocol v2 header from a TCP stream.
+/// Reads exactly the header bytes — the stream is clean for WS upgrade after.
+pub async fn read_proxy_header(stream: &mut TcpStream) -> Result<ProxyHeader>
+```
+
+- 5-second timeout on header read (constant `PROXY_HEADER_TIMEOUT`)
+- Validates 12-byte signature, version nibble, command type
+- Parses IPv4 and IPv6 address blocks
+- LOCAL command returns `is_local: true` (caller closes connection gracefully)
+- Unit tests: valid IPv4/IPv6 headers, LOCAL command, invalid signature, truncated data
+
+**Modify: `rust/src/lib.rs`** — add `pub mod proxy_protocol;`
+
+### Phase 2: Server config + client info fields
+
+**File: `rust/src/server.rs` — `ServerConfig`**
+
+Add:
+```rust
+/// Enable PROXY protocol v2 parsing on WebSocket connections.
+/// SECURITY: Must be false when accepting direct client connections.
+pub proxy_protocol: Option<bool>,
+/// Server-level IP block list — applied at TCP accept time, before Noise handshake.
+pub connection_ip_block_list: Option<Vec<String>>,
+```
+
+**File: `rust/src/server.rs` — `ClientInfo`**
+
+Add:
+```rust
+/// Real client IP:port (from PROXY protocol header or direct TCP connection).
+pub remote_addr: Option<String>,
+```
+
+### Phase 3: ACL helper
+
+**File: `rust/src/acl.rs`**
+
+Add a public function for the server-level pre-handshake check:
+```rust
+/// Check whether a connection source IP is in a block list.
+pub fn is_connection_blocked(ip: Ipv4Addr, block_list: &[String]) -> bool {
+    ip_matches_any(ip, block_list)
+}
+```
+
+(Keeps `ip_matches_any` private; exposes only the specific check needed.)
+
+### Phase 4: WebSocket listener integration
+
+**File: `rust/src/server.rs` — `run_ws_listener()`**
+
+Between `listener.accept()` and `transport::accept_connection()`:
+
+```rust
+// Determine real client address
+let remote_addr = if state.config.proxy_protocol.unwrap_or(false) {
+    match proxy_protocol::read_proxy_header(&mut tcp_stream).await {
+        Ok(header) if header.is_local => {
+            // Health check probe — close gracefully
+            return;
+        }
+        Ok(header) => {
+            info!("PP v2: real client {} -> {}", header.src_addr, header.dst_addr);
+            Some(header.src_addr)
+        }
+        Err(e) => {
+            warn!("PP v2 parse failed from {}: {}", tcp_addr, e);
+            return; // Drop connection
+        }
+    }
+} else {
+    Some(tcp_addr) // Direct connection — use TCP SocketAddr
+};
+
+// Pre-handshake server-level block list check
+if let (Some(ref block_list), Some(ref addr)) = (&state.config.connection_ip_block_list, &remote_addr) {
+    if let std::net::IpAddr::V4(v4) = addr.ip() {
+        if acl::is_connection_blocked(v4, block_list) {
+            warn!("Connection blocked by server IP block list: {}", addr);
+            return;
+        }
+    }
+}
+
+// Then proceed with WS upgrade + handle_client_connection as before
+```
+
+Key correctness note: `read_proxy_header` reads *exactly* the PP header bytes via `read_exact`. The `TcpStream` is then in a clean state for the WS HTTP upgrade. No buffered wrapper needed.
+
+### Phase 5: Update `handle_client_connection` signature
+
+**File: `rust/src/server.rs`**
+
+Change signature:
+```rust
+async fn handle_client_connection(
+    state: Arc<ServerState>,
+    mut sink: Box<dyn TransportSink>,
+    mut stream: Box<dyn TransportStream>,
+    remote_addr: Option<std::net::SocketAddr>,  // NEW
+) -> Result<()>
+```
+
+After Noise IK handshake + registry lookup (where `client_security` is available), add connection-level per-client ACL:
+
+```rust
+if let (Some(ref sec), Some(addr)) = (&client_security, &remote_addr) {
+    if let std::net::IpAddr::V4(v4) = addr.ip() {
+        if acl::is_connection_blocked(v4, sec.ip_block_list.as_deref().unwrap_or(&[])) {
+            anyhow::bail!("Client {} connection denied: source IP {} blocked", registered_client_id, addr);
+        }
+        if let Some(ref allow) = sec.ip_allow_list {
+            if !allow.is_empty() && !acl::is_ip_allowed(v4, allow) {
+                anyhow::bail!("Client {} connection denied: source IP {} not in allow list", registered_client_id, addr);
+            }
+        }
+    }
+}
+```
+
+Populate `remote_addr` when building `ClientInfo`:
+```rust
+remote_addr: remote_addr.map(|a| a.to_string()),
+```
+
+### Phase 6: QUIC listener — pass remote addr through
+
+**File: `rust/src/server.rs` — `run_quic_listener()`**
+
+QUIC doesn't use PROXY protocol. Just pass `conn.remote_address()` through:
+```rust
+let remote = conn.remote_address();
+// ...
+handle_client_connection(state, Box::new(sink), Box::new(stream), Some(remote)).await
+```
+
+### Phase 7: TypeScript interface updates
+
+**File: `ts/smartvpn.interfaces.ts`**
+
+Add to `IVpnServerConfig`:
+```typescript
+/** Enable PROXY protocol v2 on incoming WebSocket connections.
+ *  Required when behind a reverse proxy that sends PP v2 headers. */
+proxyProtocol?: boolean;
+/** Server-level IP block list — applied at TCP accept time, before Noise handshake. */
+connectionIpBlockList?: string[];
+```
+
+Add to `IVpnClientInfo`:
+```typescript
+/** Real client IP:port (from PROXY protocol or direct TCP). */
+remoteAddr?: string;
+```
+
+### Phase 8: Tests
+
+**Rust unit tests in `proxy_protocol.rs`:**
+- `parse_valid_ipv4_header` — construct a valid PP v2 header with known IPs, verify parsed correctly
+- `parse_valid_ipv6_header` — same for IPv6
+- `parse_local_command` — health check probe returns `is_local: true`
+- `reject_invalid_signature` — random bytes rejected
+- `reject_truncated_header` — short reads fail gracefully
+- `reject_v1_header` — PROXY v1 text format rejected (we only support v2)
+
+**Rust unit tests in `acl.rs`:**
+- `is_connection_blocked` with various IP patterns
+
+**TypeScript tests:**
+- Config validation accepts `proxyProtocol: true` + `connectionIpBlockList`
+
+---
+
+## Key Files to Modify
+
+| File | Changes |
+|------|---------|
+| `rust/src/proxy_protocol.rs` | **NEW** — PP v2 parser + tests |
+| `rust/src/lib.rs` | Add `pub mod proxy_protocol;` |
+| `rust/src/server.rs` | `ServerConfig` + `ClientInfo` fields, `run_ws_listener` PP integration, `handle_client_connection` signature + connection ACL, `run_quic_listener` pass-through |
+| `rust/src/acl.rs` | Add `is_connection_blocked` public function |
+| `ts/smartvpn.interfaces.ts` | `proxyProtocol`, `connectionIpBlockList`, `remoteAddr` |
+
+---
+
+## Verification
+
+1. `cargo test` — all existing 121 tests + new PP parser tests pass
+2. `pnpm test` — all 79 TS tests pass (no PP in test setup, just config validation)
+3. Manual: `socat` or test harness to send a PP v2 header before WS upgrade, verify server logs real IP

rust/Cargo.toml

@@ -25,7 +25,19 @@ tun = { version = "0.7", features = ["async"] }
 bytes = "1"
 tokio-util = "0.7"
 futures-util = "0.3"
+async-trait = "0.1"
+quinn = "0.11"
+rustls = { version = "0.23", default-features = false, features = ["ring", "std"] }
+rcgen = "0.13"
+ring = "0.17"
+rustls-pki-types = "1"
+rustls-pemfile = "2"
+webpki-roots = "1"
 mimalloc = "0.1"
+boringtun = "0.7"
+smoltcp = { version = "0.13", default-features = false, features = ["medium-ip", "proto-ipv4", "socket-tcp", "socket-udp", "alloc"] }
+chrono = { version = "0.4", features = ["serde"] }
+ipnet = "2"
 
 [profile.release]
 opt-level = 3

rust/src/acl.rs

@@ -0,0 +1,302 @@
+use std::net::Ipv4Addr;
+use ipnet::Ipv4Net;
+
+use crate::client_registry::ClientSecurity;
+
+/// Result of an ACL check.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum AclResult {
+    Allow,
+    DenySrc,
+    DenyDst,
+}
+
+/// Check whether a connection source IP is in a server-level block list.
+/// Used for pre-handshake rejection of known-bad IPs.
+pub fn is_connection_blocked(ip: Ipv4Addr, block_list: &[String]) -> bool {
+    ip_matches_any(ip, block_list)
+}
+
+/// Check whether a source IP is allowed by allow/block lists.
+/// Returns true if the IP is permitted (not blocked and passes allow check).
+pub fn is_source_allowed(ip: Ipv4Addr, allow_list: Option<&[String]>, block_list: Option<&[String]>) -> bool {
+    // Deny overrides allow
+    if let Some(bl) = block_list {
+        if ip_matches_any(ip, bl) {
+            return false;
+        }
+    }
+    // If allow list exists and is non-empty, IP must match
+    if let Some(al) = allow_list {
+        if !al.is_empty() && !ip_matches_any(ip, al) {
+            return false;
+        }
+    }
+    true
+}
+
+/// Check whether a packet from `src_ip` to `dst_ip` is allowed by the client's security policy.
+///
+/// Evaluation order (deny overrides allow):
+/// 1. If src_ip is in ip_block_list → DenySrc
+/// 2. If dst_ip is in destination_block_list → DenyDst
+/// 3. If ip_allow_list is non-empty and src_ip is NOT in it → DenySrc
+/// 4. If destination_allow_list is non-empty and dst_ip is NOT in it → DenyDst
+/// 5. Otherwise → Allow
+pub fn check_acl(security: &ClientSecurity, src_ip: Ipv4Addr, dst_ip: Ipv4Addr) -> AclResult {
+    // Step 1: Check source block list (deny overrides)
+    if let Some(ref block_list) = security.ip_block_list {
+        if ip_matches_any(src_ip, block_list) {
+            return AclResult::DenySrc;
+        }
+    }
+
+    // Step 2: Check destination block list (deny overrides)
+    if let Some(ref block_list) = security.destination_block_list {
+        if ip_matches_any(dst_ip, block_list) {
+            return AclResult::DenyDst;
+        }
+    }
+
+    // Step 3: Check source allow list (if non-empty, must match)
+    if let Some(ref allow_list) = security.ip_allow_list {
+        if !allow_list.is_empty() && !ip_matches_any(src_ip, allow_list) {
+            return AclResult::DenySrc;
+        }
+    }
+
+    // Step 4: Check destination allow list (if non-empty, must match)
+    if let Some(ref allow_list) = security.destination_allow_list {
+        if !allow_list.is_empty() && !ip_matches_any(dst_ip, allow_list) {
+            return AclResult::DenyDst;
+        }
+    }
+
+    AclResult::Allow
+}
+
+/// Check if `ip` matches any pattern in the list.
+/// Supports: exact IP, CIDR notation, wildcard patterns (192.168.1.*),
+/// and IP ranges (192.168.1.1-192.168.1.100).
+fn ip_matches_any(ip: Ipv4Addr, patterns: &[String]) -> bool {
+    for pattern in patterns {
+        if ip_matches(ip, pattern) {
+            return true;
+        }
+    }
+    false
+}
+
+/// Check if `ip` matches a single pattern.
+fn ip_matches(ip: Ipv4Addr, pattern: &str) -> bool {
+    let pattern = pattern.trim();
+
+    // CIDR notation (e.g. 192.168.1.0/24)
+    if pattern.contains('/') {
+        if let Ok(net) = pattern.parse::<Ipv4Net>() {
+            return net.contains(&ip);
+        }
+        return false;
+    }
+
+    // IP range (e.g. 192.168.1.1-192.168.1.100)
+    if pattern.contains('-') {
+        let parts: Vec<&str> = pattern.splitn(2, '-').collect();
+        if parts.len() == 2 {
+            if let (Ok(start), Ok(end)) = (parts[0].trim().parse::<Ipv4Addr>(), parts[1].trim().parse::<Ipv4Addr>()) {
+                let ip_u32 = u32::from(ip);
+                return ip_u32 >= u32::from(start) && ip_u32 <= u32::from(end);
+            }
+        }
+        return false;
+    }
+
+    // Wildcard pattern (e.g. 192.168.1.*)
+    if pattern.contains('*') {
+        return wildcard_matches(ip, pattern);
+    }
+
+    // Exact IP match
+    if let Ok(exact) = pattern.parse::<Ipv4Addr>() {
+        return ip == exact;
+    }
+
+    false
+}
+
+/// Match an IP against a wildcard pattern like "192.168.1.*" or "10.*.*.*".
+fn wildcard_matches(ip: Ipv4Addr, pattern: &str) -> bool {
+    let ip_octets = ip.octets();
+    let pattern_parts: Vec<&str> = pattern.split('.').collect();
+    if pattern_parts.len() != 4 {
+        return false;
+    }
+    for (i, part) in pattern_parts.iter().enumerate() {
+        if *part == "*" {
+            continue;
+        }
+        if let Ok(octet) = part.parse::<u8>() {
+            if ip_octets[i] != octet {
+                return false;
+            }
+        } else {
+            return false;
+        }
+    }
+    true
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::client_registry::{ClientRateLimit, ClientSecurity};
+
+    fn security(
+        ip_allow: Option<Vec<&str>>,
+        ip_block: Option<Vec<&str>>,
+        dst_allow: Option<Vec<&str>>,
+        dst_block: Option<Vec<&str>>,
+    ) -> ClientSecurity {
+        ClientSecurity {
+            ip_allow_list: ip_allow.map(|v| v.into_iter().map(String::from).collect()),
+            ip_block_list: ip_block.map(|v| v.into_iter().map(String::from).collect()),
+            destination_allow_list: dst_allow.map(|v| v.into_iter().map(String::from).collect()),
+            destination_block_list: dst_block.map(|v| v.into_iter().map(String::from).collect()),
+            max_connections: None,
+            rate_limit: None,
+        }
+    }
+
+    fn ip(s: &str) -> Ipv4Addr {
+        s.parse().unwrap()
+    }
+
+    // ── No restrictions (empty security) ────────────────────────────────
+
+    #[test]
+    fn empty_security_allows_all() {
+        let sec = security(None, None, None, None);
+        assert_eq!(check_acl(&sec, ip("1.2.3.4"), ip("5.6.7.8")), AclResult::Allow);
+    }
+
+    #[test]
+    fn empty_lists_allow_all() {
+        let sec = security(Some(vec![]), Some(vec![]), Some(vec![]), Some(vec![]));
+        assert_eq!(check_acl(&sec, ip("1.2.3.4"), ip("5.6.7.8")), AclResult::Allow);
+    }
+
+    // ── Source IP allow list ────────────────────────────────────────────
+
+    #[test]
+    fn src_allow_exact_match() {
+        let sec = security(Some(vec!["10.0.0.1"]), None, None, None);
+        assert_eq!(check_acl(&sec, ip("10.0.0.1"), ip("5.6.7.8")), AclResult::Allow);
+        assert_eq!(check_acl(&sec, ip("10.0.0.2"), ip("5.6.7.8")), AclResult::DenySrc);
+    }
+
+    #[test]
+    fn src_allow_cidr() {
+        let sec = security(Some(vec!["192.168.1.0/24"]), None, None, None);
+        assert_eq!(check_acl(&sec, ip("192.168.1.50"), ip("5.6.7.8")), AclResult::Allow);
+        assert_eq!(check_acl(&sec, ip("192.168.2.1"), ip("5.6.7.8")), AclResult::DenySrc);
+    }
+
+    #[test]
+    fn src_allow_wildcard() {
+        let sec = security(Some(vec!["10.0.*.*"]), None, None, None);
+        assert_eq!(check_acl(&sec, ip("10.0.5.3"), ip("5.6.7.8")), AclResult::Allow);
+        assert_eq!(check_acl(&sec, ip("10.1.0.1"), ip("5.6.7.8")), AclResult::DenySrc);
+    }
+
+    #[test]
+    fn src_allow_range() {
+        let sec = security(Some(vec!["10.0.0.1-10.0.0.10"]), None, None, None);
+        assert_eq!(check_acl(&sec, ip("10.0.0.5"), ip("5.6.7.8")), AclResult::Allow);
+        assert_eq!(check_acl(&sec, ip("10.0.0.11"), ip("5.6.7.8")), AclResult::DenySrc);
+    }
+
+    // ── Source IP block list (deny overrides) ───────────────────────────
+
+    #[test]
+    fn src_block_overrides_allow() {
+        let sec = security(
+            Some(vec!["192.168.1.0/24"]),
+            Some(vec!["192.168.1.100"]),
+            None,
+            None,
+        );
+        assert_eq!(check_acl(&sec, ip("192.168.1.50"), ip("5.6.7.8")), AclResult::Allow);
+        assert_eq!(check_acl(&sec, ip("192.168.1.100"), ip("5.6.7.8")), AclResult::DenySrc);
+    }
+
+    // ── Destination allow list ──────────────────────────────────────────
+
+    #[test]
+    fn dst_allow_exact() {
+        let sec = security(None, None, Some(vec!["8.8.8.8", "8.8.4.4"]), None);
+        assert_eq!(check_acl(&sec, ip("10.0.0.1"), ip("8.8.8.8")), AclResult::Allow);
+        assert_eq!(check_acl(&sec, ip("10.0.0.1"), ip("1.1.1.1")), AclResult::DenyDst);
+    }
+
+    #[test]
+    fn dst_allow_cidr() {
+        let sec = security(None, None, Some(vec!["10.0.0.0/8"]), None);
+        assert_eq!(check_acl(&sec, ip("1.1.1.1"), ip("10.5.3.2")), AclResult::Allow);
+        assert_eq!(check_acl(&sec, ip("1.1.1.1"), ip("172.16.0.1")), AclResult::DenyDst);
+    }
+
+    // ── Destination block list (deny overrides) ─────────────────────────
+
+    #[test]
+    fn dst_block_overrides_allow() {
+        let sec = security(
+            None,
+            None,
+            Some(vec!["10.0.0.0/8"]),
+            Some(vec!["10.0.0.99"]),
+        );
+        assert_eq!(check_acl(&sec, ip("1.1.1.1"), ip("10.0.0.1")), AclResult::Allow);
+        assert_eq!(check_acl(&sec, ip("1.1.1.1"), ip("10.0.0.99")), AclResult::DenyDst);
+    }
+
+    // ── Combined source + destination ───────────────────────────────────
+
+    #[test]
+    fn combined_src_and_dst_filtering() {
+        let sec = security(
+            Some(vec!["192.168.1.0/24"]),
+            None,
+            Some(vec!["8.8.8.8"]),
+            None,
+        );
+        // Valid source, valid dest
+        assert_eq!(check_acl(&sec, ip("192.168.1.10"), ip("8.8.8.8")), AclResult::Allow);
+        // Invalid source
+        assert_eq!(check_acl(&sec, ip("10.0.0.1"), ip("8.8.8.8")), AclResult::DenySrc);
+        // Valid source, invalid dest
+        assert_eq!(check_acl(&sec, ip("192.168.1.10"), ip("1.1.1.1")), AclResult::DenyDst);
+    }
+
+    // ── IP matching edge cases ──────────────────────────────────────────
+
+    #[test]
+    fn wildcard_single_octet() {
+        assert!(ip_matches(ip("10.0.0.5"), "10.0.0.*"));
+        assert!(!ip_matches(ip("10.0.1.5"), "10.0.0.*"));
+    }
+
+    #[test]
+    fn range_boundaries() {
+        assert!(ip_matches(ip("10.0.0.1"), "10.0.0.1-10.0.0.5"));
+        assert!(ip_matches(ip("10.0.0.5"), "10.0.0.1-10.0.0.5"));
+        assert!(!ip_matches(ip("10.0.0.6"), "10.0.0.1-10.0.0.5"));
+        assert!(!ip_matches(ip("10.0.0.0"), "10.0.0.1-10.0.0.5"));
+    }
+
+    #[test]
+    fn invalid_pattern_no_match() {
+        assert!(!ip_matches(ip("10.0.0.1"), "not-an-ip"));
+        assert!(!ip_matches(ip("10.0.0.1"), "10.0.0.1/99"));
+        assert!(!ip_matches(ip("10.0.0.1"), "10.0.0"));
+    }
+}

rust/src/client.rs

@@ -1,16 +1,19 @@
 use anyhow::Result;
 use bytes::BytesMut;
-use futures_util::{SinkExt, StreamExt};
 use serde::Deserialize;
+use std::net::Ipv4Addr;
 use std::sync::Arc;
-use std::time::Duration;
+use tokio::sync::{mpsc, watch, RwLock};
-use tokio::sync::{mpsc, RwLock};
+use tracing::{info, error, warn, debug};
-use tokio_tungstenite::tungstenite::Message;
-use tracing::{info, error, warn};
 
 use crate::codec::{Frame, FrameCodec, PacketType};
 use crate::crypto;
+use crate::keepalive::{self, KeepaliveSignal, LinkHealth};
+use crate::telemetry::ConnectionQuality;
 use crate::transport;
+use crate::transport_trait::{self, TransportSink, TransportStream};
+use crate::quic_transport;
+use crate::tunnel::{self, TunConfig};
 
 /// Client configuration (matches TS IVpnClientConfig).
 #[derive(Debug, Clone, Deserialize)]
@@ -18,9 +21,20 @@ use crate::transport;
 pub struct ClientConfig {
     pub server_url: String,
     pub server_public_key: String,
+    /// Client's Noise IK static private key (base64) — required for authentication.
+    pub client_private_key: String,
+    /// Client's Noise IK static public key (base64) — for reference/display.
+    pub client_public_key: String,
     pub dns: Option<Vec<String>>,
     pub mtu: Option<u16>,
     pub keepalive_interval_secs: Option<u64>,
+    /// Transport type: "websocket" (default) or "quic".
+    pub transport: Option<String>,
+    /// For QUIC: SHA-256 hash of server certificate (base64) for cert pinning.
+    pub server_cert_hash: Option<String>,
+    /// Forwarding mode: "tun" (TUN device, requires root) or "testing" (no TUN).
+    /// Default: "testing".
+    pub forwarding_mode: Option<String>,
 }
 
 /// Client statistics.
@@ -65,6 +79,8 @@ pub struct VpnClient {
     assigned_ip: Arc<RwLock<Option<String>>>,
     shutdown_tx: Option<mpsc::Sender<()>>,
     connected_since: Arc<RwLock<Option<std::time::Instant>>>,
+    quality_rx: Option<watch::Receiver<ConnectionQuality>>,
+    link_health: Arc<RwLock<LinkHealth>>,
 }
 
 impl VpnClient {
@@ -75,6 +91,8 @@ impl VpnClient {
             assigned_ip: Arc::new(RwLock::new(None)),
             shutdown_tx: None,
             connected_since: Arc::new(RwLock::new(None)),
+            quality_rx: None,
+            link_health: Arc::new(RwLock::new(LinkHealth::Degraded)),
         }
     }
 
@@ -93,23 +111,85 @@ impl VpnClient {
         let stats = self.stats.clone();
         let assigned_ip_ref = self.assigned_ip.clone();
         let connected_since = self.connected_since.clone();
+        let link_health = self.link_health.clone();
 
-        // Decode server public key
+        // Decode keys
         let server_pub_key = base64::Engine::decode(
             &base64::engine::general_purpose::STANDARD,
             &config.server_public_key,
         )?;
+        let client_priv_key = base64::Engine::decode(
+            &base64::engine::general_purpose::STANDARD,
+            &config.client_private_key,
+        )?;
 
-        // Connect to WebSocket server
+        // Create transport based on configuration
-        let ws = transport::connect_to_server(&config.server_url).await?;
+        let (mut sink, mut stream): (Box<dyn TransportSink>, Box<dyn TransportStream>) = {
-        let (mut ws_sink, mut ws_stream) = ws.split();
+            let transport_type = config.transport.as_deref().unwrap_or("auto");
+            match transport_type {
+                "quic" => {
+                    let server_addr = &config.server_url; // For QUIC, serverUrl is host:port
+                    let cert_hash = config.server_cert_hash.as_deref();
+                    let conn = quic_transport::connect_quic(server_addr, cert_hash).await?;
+                    let (quic_sink, quic_stream) = quic_transport::open_quic_streams(conn).await?;
+                    info!("Connected via QUIC");
+                    (Box::new(quic_sink) as Box<dyn TransportSink>,
+                     Box::new(quic_stream) as Box<dyn TransportStream>)
+                }
+                "websocket" => {
+                    let ws = transport::connect_to_server(&config.server_url).await?;
+                    let (ws_sink, ws_stream) = transport_trait::split_ws(ws);
+                    info!("Connected via WebSocket");
+                    (Box::new(ws_sink), Box::new(ws_stream))
+                }
+                _ => {
+                    // "auto" (default): try QUIC first, fall back to WebSocket
+                    // Extract host:port from the URL for QUIC attempt
+                    let quic_addr = extract_host_port(&config.server_url);
+                    let cert_hash = config.server_cert_hash.as_deref();
 
-        // Noise NK handshake (client side = initiator)
+                    if let Some(ref addr) = quic_addr {
+                        match tokio::time::timeout(
+                            std::time::Duration::from_secs(3),
+                            try_quic_connect(addr, cert_hash),
+                        ).await {
+                            Ok(Ok((quic_sink, quic_stream))) => {
+                                info!("Auto: connected via QUIC to {}", addr);
+                                (Box::new(quic_sink) as Box<dyn TransportSink>,
+                                 Box::new(quic_stream) as Box<dyn TransportStream>)
+                            }
+                            Ok(Err(e)) => {
+                                debug!("Auto: QUIC failed ({}), falling back to WebSocket", e);
+                                let ws = transport::connect_to_server(&config.server_url).await?;
+                                let (ws_sink, ws_stream) = transport_trait::split_ws(ws);
+                                info!("Auto: connected via WebSocket (QUIC unavailable)");
+                                (Box::new(ws_sink), Box::new(ws_stream))
+                            }
+                            Err(_) => {
+                                debug!("Auto: QUIC timed out, falling back to WebSocket");
+                                let ws = transport::connect_to_server(&config.server_url).await?;
+                                let (ws_sink, ws_stream) = transport_trait::split_ws(ws);
+                                info!("Auto: connected via WebSocket (QUIC timed out)");
+                                (Box::new(ws_sink), Box::new(ws_stream))
+                            }
+                        }
+                    } else {
+                        // Can't extract host:port for QUIC, use WebSocket directly
+                        let ws = transport::connect_to_server(&config.server_url).await?;
+                        let (ws_sink, ws_stream) = transport_trait::split_ws(ws);
+                        info!("Connected via WebSocket");
+                        (Box::new(ws_sink), Box::new(ws_stream))
+                    }
+                }
+            }
+        };
+
+        // Noise IK handshake (client side = initiator, presents static key)
         *state.write().await = ClientState::Handshaking;
-        let mut initiator = crypto::create_initiator(&server_pub_key)?;
+        let mut initiator = crypto::create_initiator(&client_priv_key, &server_pub_key)?;
         let mut buf = vec![0u8; 65535];
 
-        // -> e, es
+        // -> e, es, s, ss
         let len = initiator.write_message(&[], &mut buf)?;
         let init_frame = Frame {
             packet_type: PacketType::HandshakeInit,
@@ -117,13 +197,11 @@ impl VpnClient {
         };
         let mut frame_bytes = BytesMut::new();
         <FrameCodec as tokio_util::codec::Encoder<Frame>>::encode(&mut FrameCodec, init_frame, &mut frame_bytes)?;
-        ws_sink.send(Message::Binary(frame_bytes.to_vec().into())).await?;
+        sink.send_reliable(frame_bytes.to_vec()).await?;
 
-        // <- e, ee
+        // <- e, ee, se
-        let resp_msg = match ws_stream.next().await {
+        let resp_msg = match stream.recv_reliable().await? {
-            Some(Ok(Message::Binary(data))) => data.to_vec(),
+            Some(data) => data,
-            Some(Ok(_)) => anyhow::bail!("Expected binary handshake response"),
-            Some(Err(e)) => anyhow::bail!("WebSocket error during handshake: {}", e),
             None => anyhow::bail!("Connection closed during handshake"),
         };
 
@@ -139,9 +217,9 @@ impl VpnClient {
         let mut noise_transport = initiator.into_transport_mode()?;
 
         // Receive assigned IP info (encrypted)
-        let info_msg = match ws_stream.next().await {
+        let info_msg = match stream.recv_reliable().await? {
-            Some(Ok(Message::Binary(data))) => data.to_vec(),
+            Some(data) => data,
-            _ => anyhow::bail!("Expected IP info message"),
+            None => anyhow::bail!("Connection closed before IP info"),
         };
 
         let mut frame_buf = BytesMut::from(&info_msg[..]);
@@ -161,16 +239,60 @@ impl VpnClient {
 
         info!("Connected to VPN, assigned IP: {}", assigned_ip);
 
+        // Optionally create TUN device for IP packet forwarding (requires root)
+        let tun_enabled = config.forwarding_mode.as_deref() == Some("tun");
+        let (tun_reader, tun_writer, tun_subnet) = if tun_enabled {
+            let client_tun_ip: Ipv4Addr = assigned_ip.parse()?;
+            let mtu = ip_info["mtu"].as_u64().unwrap_or(1420) as u16;
+            let tun_config = TunConfig {
+                name: "svpn-client0".to_string(),
+                address: client_tun_ip,
+                netmask: Ipv4Addr::new(255, 255, 255, 0),
+                mtu,
+            };
+            let tun_device = tunnel::create_tun(&tun_config)?;
+
+            // Add route for VPN subnet through the TUN device
+            let gateway_str = ip_info["gateway"].as_str().unwrap_or("10.8.0.1");
+            let gateway: Ipv4Addr = gateway_str.parse().unwrap_or(Ipv4Addr::new(10, 8, 0, 1));
+            let subnet = format!("{}/24", Ipv4Addr::from(u32::from(gateway) & 0xFFFFFF00));
+            tunnel::add_route(&subnet, &tun_config.name).await?;
+
+            let (reader, writer) = tokio::io::split(tun_device);
+            (Some(reader), Some(writer), Some(subnet))
+        } else {
+            (None, None, None)
+        };
+
+        // Create adaptive keepalive monitor (use custom interval if configured)
+        let ka_config = config.keepalive_interval_secs.map(|secs| {
+            let mut cfg = keepalive::AdaptiveKeepaliveConfig::default();
+            cfg.degraded_interval = std::time::Duration::from_secs(secs);
+            cfg.healthy_interval = std::time::Duration::from_secs(secs * 2);
+            cfg.critical_interval = std::time::Duration::from_secs((secs / 3).max(1));
+            cfg
+        });
+        let (monitor, handle) = keepalive::create_keepalive(ka_config);
+        self.quality_rx = Some(handle.quality_rx);
+
+        // Spawn the keepalive monitor
+        tokio::spawn(monitor.run());
+
         // Spawn packet forwarding loop
         let assigned_ip_clone = assigned_ip.clone();
         tokio::spawn(client_loop(
-            ws_sink,
+            sink,
-            ws_stream,
+            stream,
             noise_transport,
             state,
             stats,
             shutdown_rx,
-            config.keepalive_interval_secs.unwrap_or(30),
+            handle.signal_rx,
+            handle.ack_tx,
+            link_health,
+            tun_reader,
+            tun_writer,
+            tun_subnet,
         ));
 
         Ok(assigned_ip_clone)
@@ -184,6 +306,7 @@ impl VpnClient {
         *self.assigned_ip.write().await = None;
         *self.connected_since.write().await = None;
         *self.state.write().await = ClientState::Disconnected;
+        self.quality_rx = None;
         info!("Disconnected from VPN");
         Ok(())
     }
@@ -208,13 +331,14 @@ impl VpnClient {
         status
     }
 
-    /// Get traffic statistics.
+    /// Get traffic statistics (includes connection quality).
     pub async fn get_statistics(&self) -> serde_json::Value {
         let stats = self.stats.read().await;
         let since = self.connected_since.read().await;
         let uptime = since.map(|s| s.elapsed().as_secs()).unwrap_or(0);
+        let health = self.link_health.read().await;
 
-        serde_json::json!({
+        let mut result = serde_json::json!({
             "bytesSent": stats.bytes_sent,
             "bytesReceived": stats.bytes_received,
             "packetsSent": stats.packets_sent,
@@ -222,30 +346,64 @@ impl VpnClient {
             "keepalivesSent": stats.keepalives_sent,
             "keepalivesReceived": stats.keepalives_received,
             "uptimeSeconds": uptime,
-        })
+        });
+
+        // Include connection quality if available
+        if let Some(ref rx) = self.quality_rx {
+            let quality = rx.borrow().clone();
+            result["quality"] = serde_json::json!({
+                "srttMs": quality.srtt_ms,
+                "jitterMs": quality.jitter_ms,
+                "minRttMs": quality.min_rtt_ms,
+                "maxRttMs": quality.max_rtt_ms,
+                "lossRatio": quality.loss_ratio,
+                "consecutiveTimeouts": quality.consecutive_timeouts,
+                "linkHealth": format!("{}", *health),
+                "keepalivesSent": quality.keepalives_sent,
+                "keepalivesAcked": quality.keepalives_acked,
+            });
+        }
+
+        result
+    }
+
+    /// Get connection quality snapshot.
+    pub fn get_connection_quality(&self) -> Option<ConnectionQuality> {
+        self.quality_rx.as_ref().map(|rx| rx.borrow().clone())
+    }
+
+    /// Get current link health.
+    pub async fn get_link_health(&self) -> LinkHealth {
+        *self.link_health.read().await
     }
 }
 
 /// The main client packet forwarding loop (runs in a spawned task).
 async fn client_loop(
-    mut ws_sink: futures_util::stream::SplitSink<transport::WsStream, Message>,
+    mut sink: Box<dyn TransportSink>,
-    mut ws_stream: futures_util::stream::SplitStream<transport::WsStream>,
+    mut stream: Box<dyn TransportStream>,
     mut noise_transport: snow::TransportState,
     state: Arc<RwLock<ClientState>>,
     stats: Arc<RwLock<ClientStatistics>>,
     mut shutdown_rx: mpsc::Receiver<()>,
-    keepalive_secs: u64,
+    mut signal_rx: mpsc::Receiver<KeepaliveSignal>,
+    ack_tx: mpsc::Sender<()>,
+    link_health: Arc<RwLock<LinkHealth>>,
+    mut tun_reader: Option<tokio::io::ReadHalf<tun::AsyncDevice>>,
+    mut tun_writer: Option<tokio::io::WriteHalf<tun::AsyncDevice>>,
+    tun_subnet: Option<String>,
 ) {
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
+
     let mut buf = vec![0u8; 65535];
-    let mut keepalive_ticker = tokio::time::interval(Duration::from_secs(keepalive_secs));
+    let mut tun_buf = vec![0u8; 65536];
-    keepalive_ticker.tick().await; // skip first immediate tick
 
     loop {
         tokio::select! {
-            msg = ws_stream.next() => {
+            msg = stream.recv_reliable() => {
                 match msg {
-                    Some(Ok(Message::Binary(data))) => {
+                    Ok(Some(data)) => {
-                        let mut frame_buf = BytesMut::from(&data[..][..]);
+                        let mut frame_buf = BytesMut::from(&data[..]);
                         if let Ok(Some(frame)) = <FrameCodec as tokio_util::codec::Decoder>::decode(&mut FrameCodec, &mut frame_buf) {
                             match frame.packet_type {
                                 PacketType::IpPacket => {
@@ -254,6 +412,14 @@ async fn client_loop(
                                             let mut s = stats.write().await;
                                             s.bytes_received += len as u64;
                                             s.packets_received += 1;
+                                            drop(s);
+
+                                            // Write decrypted packet to TUN device (if enabled)
+                                            if let Some(ref mut writer) = tun_writer {
+                                                if let Err(e) = writer.write_all(&buf[..len]).await {
+                                                    warn!("TUN write error: {}", e);
+                                                }
+                                            }
                                         }
                                         Err(e) => {
                                             warn!("Decrypt error: {}", e);
@@ -264,6 +430,8 @@ async fn client_loop(
                                 }
                                 PacketType::KeepaliveAck => {
                                     stats.write().await.keepalives_received += 1;
+                                    // Signal the keepalive monitor that ACK was received
+                                    let _ = ack_tx.send(()).await;
                                 }
                                 PacketType::Disconnect => {
                                     info!("Server sent disconnect");
@@ -274,35 +442,93 @@ async fn client_loop(
                             }
                         }
                     }
-                    Some(Ok(Message::Close(_))) | None => {
+                    Ok(None) => {
                         info!("Connection closed");
                         *state.write().await = ClientState::Disconnected;
                         break;
                     }
-                    Some(Ok(Message::Ping(data))) => {
+                    Err(e) => {
-                        let _ = ws_sink.send(Message::Pong(data)).await;
+                        error!("Transport error: {}", e);
-                    }
-                    Some(Ok(_)) => continue,
-                    Some(Err(e)) => {
-                        error!("WebSocket error: {}", e);
                         *state.write().await = ClientState::Error(e.to_string());
                         break;
                     }
                 }
             }
-            _ = keepalive_ticker.tick() => {
+            // Read outbound packets from TUN and send to server (only when TUN enabled)
-                let ka_frame = Frame {
+            result = async {
-                    packet_type: PacketType::Keepalive,
+                match tun_reader {
-                    payload: vec![],
+                    Some(ref mut reader) => reader.read(&mut tun_buf).await,
-                };
+                    None => std::future::pending::<std::io::Result<usize>>().await,
-                let mut frame_bytes = BytesMut::new();
+                }
-                if <FrameCodec as tokio_util::codec::Encoder<Frame>>::encode(&mut FrameCodec, ka_frame, &mut frame_bytes).is_ok() {
+            } => {
-                    if ws_sink.send(Message::Binary(frame_bytes.to_vec().into())).await.is_err() {
+                match result {
-                        warn!("Failed to send keepalive");
+                    Ok(0) => {
+                        info!("TUN device closed");
+                        break;
+                    }
+                    Ok(n) => {
+                        match noise_transport.write_message(&tun_buf[..n], &mut buf) {
+                            Ok(len) => {
+                                let frame = Frame {
+                                    packet_type: PacketType::IpPacket,
+                                    payload: buf[..len].to_vec(),
+                                };
+                                let mut frame_bytes = BytesMut::new();
+                                if <FrameCodec as tokio_util::codec::Encoder<Frame>>::encode(
+                                    &mut FrameCodec, frame, &mut frame_bytes
+                                ).is_ok() {
+                                    if sink.send_reliable(frame_bytes.to_vec()).await.is_err() {
+                                        warn!("Failed to send TUN packet to server");
+                                        break;
+                                    }
+                                    let mut s = stats.write().await;
+                                    s.bytes_sent += n as u64;
+                                    s.packets_sent += 1;
+                                }
+                            }
+                            Err(e) => {
+                                warn!("Noise encrypt error: {}", e);
+                                break;
+                            }
+                        }
+                    }
+                    Err(e) => {
+                        warn!("TUN read error: {}", e);
+                        break;
+                    }
+                }
+            }
+            signal = signal_rx.recv() => {
+                match signal {
+                    Some(KeepaliveSignal::SendPing(timestamp_ms)) => {
+                        // Embed the timestamp in the keepalive payload (8 bytes, big-endian)
+                        let ka_frame = Frame {
+                            packet_type: PacketType::Keepalive,
+                            payload: timestamp_ms.to_be_bytes().to_vec(),
+                        };
+                        let mut frame_bytes = BytesMut::new();
+                        if <FrameCodec as tokio_util::codec::Encoder<Frame>>::encode(&mut FrameCodec, ka_frame, &mut frame_bytes).is_ok() {
+                            if sink.send_reliable(frame_bytes.to_vec()).await.is_err() {
+                                warn!("Failed to send keepalive");
+                                *state.write().await = ClientState::Disconnected;
+                                break;
+                            }
+                            stats.write().await.keepalives_sent += 1;
+                        }
+                    }
+                    Some(KeepaliveSignal::PeerDead) => {
+                        warn!("Peer declared dead by keepalive monitor");
                         *state.write().await = ClientState::Disconnected;
                         break;
                     }
-                    stats.write().await.keepalives_sent += 1;
+                    Some(KeepaliveSignal::LinkHealthChanged(health)) => {
+                        debug!("Link health changed to: {}", health);
+                        *link_health.write().await = health;
+                    }
+                    None => {
+                        // Keepalive monitor channel closed
+                        break;
+                    }
                 }
             }
             _ = shutdown_rx.recv() => {
@@ -313,12 +539,58 @@ async fn client_loop(
                 };
                 let mut frame_bytes = BytesMut::new();
                 if <FrameCodec as tokio_util::codec::Encoder<Frame>>::encode(&mut FrameCodec, dc_frame, &mut frame_bytes).is_ok() {
-                    let _ = ws_sink.send(Message::Binary(frame_bytes.to_vec().into())).await;
+                    let _ = sink.send_reliable(frame_bytes.to_vec()).await;
                 }
-                let _ = ws_sink.close().await;
+                let _ = sink.close().await;
                 *state.write().await = ClientState::Disconnected;
                 break;
             }
         }
     }
+
+    // Cleanup: remove TUN route if enabled
+    if let Some(ref subnet) = tun_subnet {
+        if let Err(e) = tunnel::remove_route(subnet, "svpn-client0").await {
+            warn!("Failed to remove client TUN route: {}", e);
+        }
+    }
+}
+
+/// Try to connect via QUIC. Returns transport halves on success.
+async fn try_quic_connect(
+    addr: &str,
+    cert_hash: Option<&str>,
+) -> Result<(quic_transport::QuicTransportSink, quic_transport::QuicTransportStream)> {
+    let conn = quic_transport::connect_quic(addr, cert_hash).await?;
+    let (sink, stream) = quic_transport::open_quic_streams(conn).await?;
+    Ok((sink, stream))
+}
+
+/// Extract host:port from a WebSocket URL for QUIC auto-fallback.
+/// e.g. "ws://127.0.0.1:8080" -> Some("127.0.0.1:8080")
+///      "wss://vpn.example.com/tunnel" -> Some("vpn.example.com:443")
+///      "127.0.0.1:8080" -> Some("127.0.0.1:8080") (already host:port)
+fn extract_host_port(url: &str) -> Option<String> {
+    if url.starts_with("ws://") || url.starts_with("wss://") {
+        // Parse as URL
+        let stripped = if url.starts_with("wss://") {
+            &url[6..]
+        } else {
+            &url[5..]
+        };
+        // Remove path
+        let host_port = stripped.split('/').next()?;
+        if host_port.contains(':') {
+            Some(host_port.to_string())
+        } else {
+            // Default port
+            let default_port = if url.starts_with("wss://") { 443 } else { 80 };
+            Some(format!("{}:{}", host_port, default_port))
+        }
+    } else if url.contains(':') {
+        // Already host:port
+        Some(url.to_string())
+    } else {
+        None
+    }
 }

rust/src/client_registry.rs

@@ -0,0 +1,362 @@
+use anyhow::Result;
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+
+/// Per-client rate limiting configuration.
+#[derive(Debug, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ClientRateLimit {
+    pub bytes_per_sec: u64,
+    pub burst_bytes: u64,
+}
+
+/// Per-client security settings — aligned with SmartProxy's IRouteSecurity pattern.
+#[derive(Debug, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ClientSecurity {
+    /// Source IPs/CIDRs the client may connect FROM (empty/None = any).
+    pub ip_allow_list: Option<Vec<String>>,
+    /// Source IPs blocked — overrides ip_allow_list (deny wins).
+    pub ip_block_list: Option<Vec<String>>,
+    /// Destination IPs/CIDRs the client may reach (empty/None = all).
+    pub destination_allow_list: Option<Vec<String>>,
+    /// Destination IPs blocked — overrides destination_allow_list (deny wins).
+    pub destination_block_list: Option<Vec<String>>,
+    /// Max concurrent connections from this client.
+    pub max_connections: Option<u32>,
+    /// Per-client rate limiting.
+    pub rate_limit: Option<ClientRateLimit>,
+}
+
+/// A registered client entry — the server-side source of truth.
+#[derive(Debug, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ClientEntry {
+    /// Human-readable client ID (e.g. "alice-laptop").
+    pub client_id: String,
+    /// Client's Noise IK public key (base64).
+    pub public_key: String,
+    /// Client's WireGuard public key (base64) — optional.
+    pub wg_public_key: Option<String>,
+    /// Security settings (ACLs, rate limits).
+    pub security: Option<ClientSecurity>,
+    /// Traffic priority (lower = higher priority, default: 100).
+    pub priority: Option<u32>,
+    /// Whether this client is enabled (default: true).
+    pub enabled: Option<bool>,
+    /// Tags for grouping.
+    pub tags: Option<Vec<String>>,
+    /// Optional description.
+    pub description: Option<String>,
+    /// Optional expiry (ISO 8601 timestamp).
+    pub expires_at: Option<String>,
+    /// Assigned VPN IP address.
+    pub assigned_ip: Option<String>,
+}
+
+impl ClientEntry {
+    /// Whether this client is considered enabled (defaults to true).
+    pub fn is_enabled(&self) -> bool {
+        self.enabled.unwrap_or(true)
+    }
+
+    /// Whether this client has expired based on current time.
+    pub fn is_expired(&self) -> bool {
+        if let Some(ref expires) = self.expires_at {
+            if let Ok(expiry) = chrono::DateTime::parse_from_rfc3339(expires) {
+                return chrono::Utc::now() > expiry;
+            }
+        }
+        false
+    }
+}
+
+/// In-memory client registry with dual-key indexing.
+pub struct ClientRegistry {
+    /// Primary index: clientId → ClientEntry
+    entries: HashMap<String, ClientEntry>,
+    /// Secondary index: publicKey (base64) → clientId (fast lookup during handshake)
+    key_index: HashMap<String, String>,
+}
+
+impl ClientRegistry {
+    pub fn new() -> Self {
+        Self {
+            entries: HashMap::new(),
+            key_index: HashMap::new(),
+        }
+    }
+
+    /// Build a registry from a list of client entries.
+    pub fn from_entries(entries: Vec<ClientEntry>) -> Result<Self> {
+        let mut registry = Self::new();
+        for entry in entries {
+            registry.add(entry)?;
+        }
+        Ok(registry)
+    }
+
+    /// Add a client to the registry.
+    pub fn add(&mut self, entry: ClientEntry) -> Result<()> {
+        if self.entries.contains_key(&entry.client_id) {
+            anyhow::bail!("Client '{}' already exists", entry.client_id);
+        }
+        if self.key_index.contains_key(&entry.public_key) {
+            anyhow::bail!("Public key already registered to another client");
+        }
+        self.key_index.insert(entry.public_key.clone(), entry.client_id.clone());
+        self.entries.insert(entry.client_id.clone(), entry);
+        Ok(())
+    }
+
+    /// Remove a client by ID.
+    pub fn remove(&mut self, client_id: &str) -> Result<ClientEntry> {
+        let entry = self.entries.remove(client_id)
+            .ok_or_else(|| anyhow::anyhow!("Client '{}' not found", client_id))?;
+        self.key_index.remove(&entry.public_key);
+        Ok(entry)
+    }
+
+    /// Get a client by ID.
+    pub fn get_by_id(&self, client_id: &str) -> Option<&ClientEntry> {
+        self.entries.get(client_id)
+    }
+
+    /// Get a client by public key (used during IK handshake verification).
+    pub fn get_by_key(&self, public_key: &str) -> Option<&ClientEntry> {
+        let client_id = self.key_index.get(public_key)?;
+        self.entries.get(client_id)
+    }
+
+    /// Check if a public key is authorized (exists, enabled, not expired).
+    pub fn is_authorized(&self, public_key: &str) -> bool {
+        match self.get_by_key(public_key) {
+            Some(entry) => entry.is_enabled() && !entry.is_expired(),
+            None => false,
+        }
+    }
+
+    /// Update a client entry. The closure receives a mutable reference to the entry.
+    pub fn update<F>(&mut self, client_id: &str, updater: F) -> Result<()>
+    where
+        F: FnOnce(&mut ClientEntry),
+    {
+        let entry = self.entries.get_mut(client_id)
+            .ok_or_else(|| anyhow::anyhow!("Client '{}' not found", client_id))?;
+        let old_key = entry.public_key.clone();
+        updater(entry);
+        // If public key changed, update the index
+        if entry.public_key != old_key {
+            self.key_index.remove(&old_key);
+            self.key_index.insert(entry.public_key.clone(), client_id.to_string());
+        }
+        Ok(())
+    }
+
+    /// List all client entries.
+    pub fn list(&self) -> Vec<&ClientEntry> {
+        self.entries.values().collect()
+    }
+
+    /// Rotate a client's keys. Returns the updated entry.
+    pub fn rotate_key(&mut self, client_id: &str, new_public_key: String, new_wg_public_key: Option<String>) -> Result<()> {
+        let entry = self.entries.get_mut(client_id)
+            .ok_or_else(|| anyhow::anyhow!("Client '{}' not found", client_id))?;
+        // Update key index
+        self.key_index.remove(&entry.public_key);
+        entry.public_key = new_public_key.clone();
+        entry.wg_public_key = new_wg_public_key;
+        self.key_index.insert(new_public_key, client_id.to_string());
+        Ok(())
+    }
+
+    /// Number of registered clients.
+    pub fn len(&self) -> usize {
+        self.entries.len()
+    }
+
+    /// Whether the registry is empty.
+    pub fn is_empty(&self) -> bool {
+        self.entries.is_empty()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn make_entry(id: &str, key: &str) -> ClientEntry {
+        ClientEntry {
+            client_id: id.to_string(),
+            public_key: key.to_string(),
+            wg_public_key: None,
+            security: None,
+            priority: None,
+            enabled: None,
+            tags: None,
+            description: None,
+            expires_at: None,
+            assigned_ip: None,
+        }
+    }
+
+    #[test]
+    fn add_and_lookup() {
+        let mut reg = ClientRegistry::new();
+        reg.add(make_entry("alice", "key_alice")).unwrap();
+
+        assert!(reg.get_by_id("alice").is_some());
+        assert!(reg.get_by_key("key_alice").is_some());
+        assert_eq!(reg.get_by_key("key_alice").unwrap().client_id, "alice");
+        assert!(reg.get_by_id("bob").is_none());
+        assert!(reg.get_by_key("key_bob").is_none());
+    }
+
+    #[test]
+    fn reject_duplicate_id() {
+        let mut reg = ClientRegistry::new();
+        reg.add(make_entry("alice", "key1")).unwrap();
+        assert!(reg.add(make_entry("alice", "key2")).is_err());
+    }
+
+    #[test]
+    fn reject_duplicate_key() {
+        let mut reg = ClientRegistry::new();
+        reg.add(make_entry("alice", "same_key")).unwrap();
+        assert!(reg.add(make_entry("bob", "same_key")).is_err());
+    }
+
+    #[test]
+    fn remove_client() {
+        let mut reg = ClientRegistry::new();
+        reg.add(make_entry("alice", "key_alice")).unwrap();
+        assert_eq!(reg.len(), 1);
+
+        let removed = reg.remove("alice").unwrap();
+        assert_eq!(removed.client_id, "alice");
+        assert_eq!(reg.len(), 0);
+        assert!(reg.get_by_key("key_alice").is_none());
+    }
+
+    #[test]
+    fn remove_nonexistent_fails() {
+        let mut reg = ClientRegistry::new();
+        assert!(reg.remove("ghost").is_err());
+    }
+
+    #[test]
+    fn is_authorized_enabled() {
+        let mut reg = ClientRegistry::new();
+        reg.add(make_entry("alice", "key_alice")).unwrap();
+        assert!(reg.is_authorized("key_alice")); // enabled by default
+    }
+
+    #[test]
+    fn is_authorized_disabled() {
+        let mut reg = ClientRegistry::new();
+        let mut entry = make_entry("alice", "key_alice");
+        entry.enabled = Some(false);
+        reg.add(entry).unwrap();
+        assert!(!reg.is_authorized("key_alice"));
+    }
+
+    #[test]
+    fn is_authorized_expired() {
+        let mut reg = ClientRegistry::new();
+        let mut entry = make_entry("alice", "key_alice");
+        entry.expires_at = Some("2020-01-01T00:00:00Z".to_string());
+        reg.add(entry).unwrap();
+        assert!(!reg.is_authorized("key_alice"));
+    }
+
+    #[test]
+    fn is_authorized_future_expiry() {
+        let mut reg = ClientRegistry::new();
+        let mut entry = make_entry("alice", "key_alice");
+        entry.expires_at = Some("2099-01-01T00:00:00Z".to_string());
+        reg.add(entry).unwrap();
+        assert!(reg.is_authorized("key_alice"));
+    }
+
+    #[test]
+    fn is_authorized_unknown_key() {
+        let reg = ClientRegistry::new();
+        assert!(!reg.is_authorized("nonexistent"));
+    }
+
+    #[test]
+    fn update_client() {
+        let mut reg = ClientRegistry::new();
+        reg.add(make_entry("alice", "key_alice")).unwrap();
+
+        reg.update("alice", |entry| {
+            entry.description = Some("Updated".to_string());
+            entry.enabled = Some(false);
+        }).unwrap();
+
+        let entry = reg.get_by_id("alice").unwrap();
+        assert_eq!(entry.description.as_deref(), Some("Updated"));
+        assert!(!entry.is_enabled());
+    }
+
+    #[test]
+    fn update_nonexistent_fails() {
+        let mut reg = ClientRegistry::new();
+        assert!(reg.update("ghost", |_| {}).is_err());
+    }
+
+    #[test]
+    fn rotate_key() {
+        let mut reg = ClientRegistry::new();
+        reg.add(make_entry("alice", "old_key")).unwrap();
+
+        reg.rotate_key("alice", "new_key".to_string(), None).unwrap();
+
+        assert!(reg.get_by_key("old_key").is_none());
+        assert!(reg.get_by_key("new_key").is_some());
+        assert_eq!(reg.get_by_id("alice").unwrap().public_key, "new_key");
+    }
+
+    #[test]
+    fn from_entries() {
+        let entries = vec![
+            make_entry("alice", "key_a"),
+            make_entry("bob", "key_b"),
+        ];
+        let reg = ClientRegistry::from_entries(entries).unwrap();
+        assert_eq!(reg.len(), 2);
+        assert!(reg.get_by_key("key_a").is_some());
+        assert!(reg.get_by_key("key_b").is_some());
+    }
+
+    #[test]
+    fn list_clients() {
+        let mut reg = ClientRegistry::new();
+        reg.add(make_entry("alice", "key_a")).unwrap();
+        reg.add(make_entry("bob", "key_b")).unwrap();
+        let list = reg.list();
+        assert_eq!(list.len(), 2);
+    }
+
+    #[test]
+    fn security_with_rate_limit() {
+        let mut entry = make_entry("alice", "key_alice");
+        entry.security = Some(ClientSecurity {
+            ip_allow_list: Some(vec!["192.168.1.0/24".to_string()]),
+            ip_block_list: Some(vec!["192.168.1.100".to_string()]),
+            destination_allow_list: None,
+            destination_block_list: None,
+            max_connections: Some(5),
+            rate_limit: Some(ClientRateLimit {
+                bytes_per_sec: 1_000_000,
+                burst_bytes: 2_000_000,
+            }),
+        });
+        let mut reg = ClientRegistry::new();
+        reg.add(entry).unwrap();
+        let e = reg.get_by_id("alice").unwrap();
+        let sec = e.security.as_ref().unwrap();
+        assert_eq!(sec.rate_limit.as_ref().unwrap().bytes_per_sec, 1_000_000);
+        assert_eq!(sec.max_connections, Some(5));
+    }
+}

rust/src/crypto.rs

@@ -3,8 +3,10 @@ use base64::Engine;
 use base64::engine::general_purpose::STANDARD as BASE64;
 use snow::Builder;
 
-/// Noise protocol pattern: NK (client knows server pubkey, no client auth at Noise level)
+/// Noise protocol pattern: IK (client presents static key, server authenticates client)
-const NOISE_PATTERN: &str = "Noise_NK_25519_ChaChaPoly_BLAKE2s";
+/// IK = Initiator's static key is transmitted; responder's Key is pre-known.
+/// This provides mutual authentication: server verifies client identity via public key.
+const NOISE_PATTERN: &str = "Noise_IK_25519_ChaChaPoly_BLAKE2s";
 
 /// Generate a new Noise static keypair.
 /// Returns (public_key_base64, private_key_base64).
@@ -22,18 +24,23 @@ pub fn generate_keypair_raw() -> Result<snow::Keypair> {
     Ok(builder.generate_keypair()?)
 }
 
-/// Create a Noise NK initiator (client side).
+/// Create a Noise IK initiator (client side).
-/// The client knows the server's static public key.
+/// The client provides its own static keypair AND the server's public key.
-pub fn create_initiator(server_public_key: &[u8]) -> Result<snow::HandshakeState> {
+/// The client's static key is transmitted (encrypted) during the handshake,
+/// allowing the server to authenticate the client.
+pub fn create_initiator(client_private_key: &[u8], server_public_key: &[u8]) -> Result<snow::HandshakeState> {
     let builder = Builder::new(NOISE_PATTERN.parse()?);
     let state = builder
+        .local_private_key(client_private_key)
         .remote_public_key(server_public_key)
         .build_initiator()?;
     Ok(state)
 }
 
-/// Create a Noise NK responder (server side).
+/// Create a Noise IK responder (server side).
 /// The server uses its static private key.
+/// After the handshake, call `get_remote_static()` on the HandshakeState
+/// (before `into_transport_mode()`) to retrieve the client's public key.
 pub fn create_responder(private_key: &[u8]) -> Result<snow::HandshakeState> {
     let builder = Builder::new(NOISE_PATTERN.parse()?);
     let state = builder
@@ -42,19 +49,20 @@ pub fn create_responder(private_key: &[u8]) -> Result<snow::HandshakeState> {
     Ok(state)
 }
 
-/// Perform the full Noise NK handshake between initiator and responder.
+/// Perform the full Noise IK handshake between initiator and responder.
-/// Returns (initiator_transport, responder_transport).
+/// Returns (initiator_transport, responder_transport, client_public_key).
+/// The client_public_key is extracted from the responder before entering transport mode.
 pub fn perform_handshake(
     mut initiator: snow::HandshakeState,
     mut responder: snow::HandshakeState,
-) -> Result<(snow::TransportState, snow::TransportState)> {
+) -> Result<(snow::TransportState, snow::TransportState, Vec<u8>)> {
     let mut buf = vec![0u8; 65535];
 
-    // -> e, es (initiator sends)
+    // -> e, es, s, ss (initiator sends ephemeral + encrypted static key)
     let len = initiator.write_message(&[], &mut buf)?;
     let msg1 = buf[..len].to_vec();
 
-    // <- e, ee (responder reads and responds)
+    // <- e, ee, se (responder reads and responds)
     responder.read_message(&msg1, &mut buf)?;
     let len = responder.write_message(&[], &mut buf)?;
     let msg2 = buf[..len].to_vec();
@@ -62,10 +70,16 @@ pub fn perform_handshake(
     // Initiator reads response
     initiator.read_message(&msg2, &mut buf)?;
 
+    // Extract client's public key from responder BEFORE entering transport mode
+    let client_public_key = responder
+        .get_remote_static()
+        .ok_or_else(|| anyhow::anyhow!("IK handshake did not provide client static key"))?
+        .to_vec();
+
     let i_transport = initiator.into_transport_mode()?;
     let r_transport = responder.into_transport_mode()?;
 
-    Ok((i_transport, r_transport))
+    Ok((i_transport, r_transport, client_public_key))
 }
 
 /// XChaCha20-Poly1305 encryption for post-handshake data.
@@ -135,15 +149,19 @@ mod tests {
     }
 
     #[test]
-    fn noise_handshake() {
+    fn noise_ik_handshake() {
         let server_kp = generate_keypair_raw().unwrap();
+        let client_kp = generate_keypair_raw().unwrap();
 
-        let initiator = create_initiator(&server_kp.public).unwrap();
+        let initiator = create_initiator(&client_kp.private, &server_kp.public).unwrap();
         let responder = create_responder(&server_kp.private).unwrap();
 
-        let (mut i_transport, mut r_transport) =
+        let (mut i_transport, mut r_transport, remote_key) =
             perform_handshake(initiator, responder).unwrap();
 
+        // Verify the server received the client's public key
+        assert_eq!(remote_key, client_kp.public);
+
         // Test encrypted communication
         let mut buf = vec![0u8; 65535];
         let plaintext = b"hello from client";
@@ -159,6 +177,20 @@ mod tests {
         assert_eq!(&out[..len], plaintext);
     }
 
+    #[test]
+    fn noise_ik_wrong_server_key_fails() {
+        let server_kp = generate_keypair_raw().unwrap();
+        let wrong_server_kp = generate_keypair_raw().unwrap();
+        let client_kp = generate_keypair_raw().unwrap();
+
+        // Client uses wrong server public key
+        let initiator = create_initiator(&client_kp.private, &wrong_server_kp.public).unwrap();
+        let responder = create_responder(&server_kp.private).unwrap();
+
+        // Handshake should fail because client targeted wrong server
+        assert!(perform_handshake(initiator, responder).is_err());
+    }
+
     #[test]
     fn xchacha_encrypt_decrypt() {
         let key = [42u8; 32];

rust/src/keepalive.rs

@@ -1,87 +1,464 @@
 use std::time::Duration;
-use tokio::sync::mpsc;
+use tokio::sync::{mpsc, watch};
 use tokio::time::{interval, timeout};
-use tracing::{debug, warn};
+use tracing::{debug, info, warn};
 
-/// Default keepalive interval (30 seconds).
+use crate::telemetry::{ConnectionQuality, RttTracker};
+
+/// Default keepalive interval (30 seconds — used for Degraded state).
 pub const DEFAULT_KEEPALIVE_INTERVAL: Duration = Duration::from_secs(30);
 
-/// Default keepalive ACK timeout (10 seconds).
+/// Default keepalive ACK timeout (5 seconds).
-pub const DEFAULT_KEEPALIVE_TIMEOUT: Duration = Duration::from_secs(10);
+pub const DEFAULT_KEEPALIVE_TIMEOUT: Duration = Duration::from_secs(5);
+
+/// Link health states for adaptive keepalive.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum LinkHealth {
+    /// RTT stable, jitter low, no loss. Interval: 60s.
+    Healthy,
+    /// Elevated jitter or occasional loss. Interval: 30s.
+    Degraded,
+    /// High loss or sustained jitter spike. Interval: 10s.
+    Critical,
+}
+
+impl std::fmt::Display for LinkHealth {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Healthy => write!(f, "healthy"),
+            Self::Degraded => write!(f, "degraded"),
+            Self::Critical => write!(f, "critical"),
+        }
+    }
+}
+
+/// Configuration for the adaptive keepalive state machine.
+#[derive(Debug, Clone)]
+pub struct AdaptiveKeepaliveConfig {
+    /// Interval when link health is Healthy.
+    pub healthy_interval: Duration,
+    /// Interval when link health is Degraded.
+    pub degraded_interval: Duration,
+    /// Interval when link health is Critical.
+    pub critical_interval: Duration,
+    /// ACK timeout (how long to wait for ACK before declaring timeout).
+    pub ack_timeout: Duration,
+    /// Jitter threshold (ms) to enter Degraded from Healthy.
+    pub jitter_degraded_ms: f64,
+    /// Jitter threshold (ms) to return to Healthy from Degraded.
+    pub jitter_healthy_ms: f64,
+    /// Loss ratio threshold to enter Degraded.
+    pub loss_degraded: f64,
+    /// Loss ratio threshold to enter Critical.
+    pub loss_critical: f64,
+    /// Loss ratio threshold to return from Critical to Degraded.
+    pub loss_recover: f64,
+    /// Loss ratio threshold to return from Degraded to Healthy.
+    pub loss_healthy: f64,
+    /// Consecutive checks required for upward state transitions (hysteresis).
+    pub upgrade_checks: u32,
+    /// Consecutive timeouts to declare peer dead in Critical state.
+    pub dead_peer_timeouts: u32,
+}
+
+impl Default for AdaptiveKeepaliveConfig {
+    fn default() -> Self {
+        Self {
+            healthy_interval: Duration::from_secs(60),
+            degraded_interval: Duration::from_secs(30),
+            critical_interval: Duration::from_secs(10),
+            ack_timeout: Duration::from_secs(5),
+            jitter_degraded_ms: 50.0,
+            jitter_healthy_ms: 30.0,
+            loss_degraded: 0.05,
+            loss_critical: 0.20,
+            loss_recover: 0.10,
+            loss_healthy: 0.02,
+            upgrade_checks: 3,
+            dead_peer_timeouts: 3,
+        }
+    }
+}
 
 /// Signals from the keepalive monitor.
 #[derive(Debug, Clone)]
 pub enum KeepaliveSignal {
-    /// Time to send a keepalive ping.
+    /// Time to send a keepalive ping. Contains the timestamp (ms since epoch) to embed in payload.
-    SendPing,
+    SendPing(u64),
-    /// Peer is considered dead (no ACK received within timeout).
+    /// Peer is considered dead (no ACK received within timeout repeatedly).
     PeerDead,
+    /// Link health state changed.
+    LinkHealthChanged(LinkHealth),
 }
 
-/// A keepalive monitor that emits signals on a channel.
+/// A keepalive monitor with adaptive interval and RTT tracking.
 pub struct KeepaliveMonitor {
-    interval: Duration,
+    config: AdaptiveKeepaliveConfig,
-    timeout_duration: Duration,
+    health: LinkHealth,
+    rtt_tracker: RttTracker,
     signal_tx: mpsc::Sender<KeepaliveSignal>,
     ack_rx: mpsc::Receiver<()>,
+    quality_tx: watch::Sender<ConnectionQuality>,
+    consecutive_upgrade_checks: u32,
 }
 
 /// Handle returned to the caller to send ACKs and receive signals.
 pub struct KeepaliveHandle {
     pub signal_rx: mpsc::Receiver<KeepaliveSignal>,
     pub ack_tx: mpsc::Sender<()>,
+    pub quality_rx: watch::Receiver<ConnectionQuality>,
 }
 
-/// Create a keepalive monitor and its handle.
+/// Create an adaptive keepalive monitor and its handle.
 pub fn create_keepalive(
-    keepalive_interval: Option<Duration>,
+    config: Option<AdaptiveKeepaliveConfig>,
-    keepalive_timeout: Option<Duration>,
 ) -> (KeepaliveMonitor, KeepaliveHandle) {
+    let config = config.unwrap_or_default();
     let (signal_tx, signal_rx) = mpsc::channel(8);
     let (ack_tx, ack_rx) = mpsc::channel(8);
+    let (quality_tx, quality_rx) = watch::channel(ConnectionQuality::default());
 
     let monitor = KeepaliveMonitor {
-        interval: keepalive_interval.unwrap_or(DEFAULT_KEEPALIVE_INTERVAL),
+        config,
-        timeout_duration: keepalive_timeout.unwrap_or(DEFAULT_KEEPALIVE_TIMEOUT),
+        health: LinkHealth::Degraded, // start in Degraded, earn Healthy
+        rtt_tracker: RttTracker::new(30),
         signal_tx,
         ack_rx,
+        quality_tx,
+        consecutive_upgrade_checks: 0,
     };
 
-    let handle = KeepaliveHandle { signal_rx, ack_tx };
+    let handle = KeepaliveHandle {
+        signal_rx,
+        ack_tx,
+        quality_rx,
+    };
 
     (monitor, handle)
 }
 
 impl KeepaliveMonitor {
+    fn current_interval(&self) -> Duration {
+        match self.health {
+            LinkHealth::Healthy => self.config.healthy_interval,
+            LinkHealth::Degraded => self.config.degraded_interval,
+            LinkHealth::Critical => self.config.critical_interval,
+        }
+    }
+
     /// Run the keepalive loop. Blocks until the peer is dead or channels close.
     pub async fn run(mut self) {
-        let mut ticker = interval(self.interval);
+        let mut ticker = interval(self.current_interval());
         ticker.tick().await; // skip first immediate tick
 
         loop {
             ticker.tick().await;
-            debug!("Sending keepalive ping signal");
 
-            if self.signal_tx.send(KeepaliveSignal::SendPing).await.is_err() {
+            // Record ping sent, get timestamp for payload
-                // Channel closed
+            let timestamp_ms = self.rtt_tracker.mark_ping_sent();
-                break;
+            debug!("Sending keepalive ping (ts={})", timestamp_ms);
+
+            if self
+                .signal_tx
+                .send(KeepaliveSignal::SendPing(timestamp_ms))
+                .await
+                .is_err()
+            {
+                break; // channel closed
             }
 
             // Wait for ACK within timeout
-            match timeout(self.timeout_duration, self.ack_rx.recv()).await {
+            match timeout(self.config.ack_timeout, self.ack_rx.recv()).await {
                 Ok(Some(())) => {
-                    debug!("Keepalive ACK received");
+                    if let Some(rtt) = self.rtt_tracker.record_ack(timestamp_ms) {
+                        debug!("Keepalive ACK received, RTT: {:?}", rtt);
+                    }
                 }
                 Ok(None) => {
-                    // Channel closed
+                    break; // channel closed
-                    break;
                 }
                 Err(_) => {
-                    warn!("Keepalive ACK timeout — peer considered dead");
+                    self.rtt_tracker.record_timeout();
-                    let _ = self.signal_tx.send(KeepaliveSignal::PeerDead).await;
+                    warn!(
-                    break;
+                        "Keepalive ACK timeout (consecutive: {})",
+                        self.rtt_tracker.consecutive_timeouts
+                    );
                 }
             }
+
+            // Publish quality snapshot
+            let quality = self.rtt_tracker.snapshot();
+            let _ = self.quality_tx.send(quality.clone());
+
+            // Evaluate state transition
+            let new_health = self.evaluate_health(&quality);
+
+            if new_health != self.health {
+                info!("Link health: {} -> {}", self.health, new_health);
+                self.health = new_health;
+                self.consecutive_upgrade_checks = 0;
+
+                // Reset ticker to new interval
+                ticker = interval(self.current_interval());
+                ticker.tick().await; // skip first immediate tick
+
+                let _ = self
+                    .signal_tx
+                    .send(KeepaliveSignal::LinkHealthChanged(new_health))
+                    .await;
+            }
+
+            // Check for dead peer in Critical state
+            if self.health == LinkHealth::Critical
+                && self.rtt_tracker.consecutive_timeouts >= self.config.dead_peer_timeouts
+            {
+                warn!("Peer considered dead after {} consecutive timeouts in Critical state",
+                    self.rtt_tracker.consecutive_timeouts);
+                let _ = self.signal_tx.send(KeepaliveSignal::PeerDead).await;
+                break;
+            }
+        }
+    }
+
+    fn evaluate_health(&mut self, quality: &ConnectionQuality) -> LinkHealth {
+        match self.health {
+            LinkHealth::Healthy => {
+                // Downgrade conditions
+                if quality.consecutive_timeouts >= 2 || quality.loss_ratio > self.config.loss_critical {
+                    self.consecutive_upgrade_checks = 0;
+                    return LinkHealth::Critical;
+                }
+                if quality.jitter_ms > self.config.jitter_degraded_ms
+                    || quality.loss_ratio > self.config.loss_degraded
+                    || quality.consecutive_timeouts >= 1
+                {
+                    self.consecutive_upgrade_checks = 0;
+                    return LinkHealth::Degraded;
+                }
+                LinkHealth::Healthy
+            }
+            LinkHealth::Degraded => {
+                // Downgrade to Critical
+                if quality.consecutive_timeouts >= 2 || quality.loss_ratio > self.config.loss_critical {
+                    self.consecutive_upgrade_checks = 0;
+                    return LinkHealth::Critical;
+                }
+                // Upgrade to Healthy (with hysteresis)
+                if quality.jitter_ms < self.config.jitter_healthy_ms
+                    && quality.loss_ratio < self.config.loss_healthy
+                    && quality.consecutive_timeouts == 0
+                {
+                    self.consecutive_upgrade_checks += 1;
+                    if self.consecutive_upgrade_checks >= self.config.upgrade_checks {
+                        self.consecutive_upgrade_checks = 0;
+                        return LinkHealth::Healthy;
+                    }
+                } else {
+                    self.consecutive_upgrade_checks = 0;
+                }
+                LinkHealth::Degraded
+            }
+            LinkHealth::Critical => {
+                // Upgrade to Degraded (with hysteresis), never directly to Healthy
+                if quality.loss_ratio < self.config.loss_recover
+                    && quality.consecutive_timeouts == 0
+                {
+                    self.consecutive_upgrade_checks += 1;
+                    if self.consecutive_upgrade_checks >= 2 {
+                        self.consecutive_upgrade_checks = 0;
+                        return LinkHealth::Degraded;
+                    }
+                } else {
+                    self.consecutive_upgrade_checks = 0;
+                }
+                LinkHealth::Critical
+            }
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn default_config_values() {
+        let config = AdaptiveKeepaliveConfig::default();
+        assert_eq!(config.healthy_interval, Duration::from_secs(60));
+        assert_eq!(config.degraded_interval, Duration::from_secs(30));
+        assert_eq!(config.critical_interval, Duration::from_secs(10));
+        assert_eq!(config.ack_timeout, Duration::from_secs(5));
+        assert_eq!(config.dead_peer_timeouts, 3);
+    }
+
+    #[test]
+    fn link_health_display() {
+        assert_eq!(format!("{}", LinkHealth::Healthy), "healthy");
+        assert_eq!(format!("{}", LinkHealth::Degraded), "degraded");
+        assert_eq!(format!("{}", LinkHealth::Critical), "critical");
+    }
+
+    // Helper to create a monitor for unit-testing evaluate_health
+    fn make_test_monitor() -> KeepaliveMonitor {
+        let (signal_tx, _signal_rx) = mpsc::channel(8);
+        let (_ack_tx, ack_rx) = mpsc::channel(8);
+        let (quality_tx, _quality_rx) = watch::channel(ConnectionQuality::default());
+
+        KeepaliveMonitor {
+            config: AdaptiveKeepaliveConfig::default(),
+            health: LinkHealth::Degraded,
+            rtt_tracker: RttTracker::new(30),
+            signal_tx,
+            ack_rx,
+            quality_tx,
+            consecutive_upgrade_checks: 0,
+        }
+    }
+
+    #[test]
+    fn healthy_to_degraded_on_jitter() {
+        let mut m = make_test_monitor();
+        m.health = LinkHealth::Healthy;
+        let q = ConnectionQuality {
+            jitter_ms: 60.0, // > 50ms threshold
+            ..Default::default()
+        };
+        let result = m.evaluate_health(&q);
+        assert_eq!(result, LinkHealth::Degraded);
+    }
+
+    #[test]
+    fn healthy_to_degraded_on_loss() {
+        let mut m = make_test_monitor();
+        m.health = LinkHealth::Healthy;
+        let q = ConnectionQuality {
+            loss_ratio: 0.06, // > 5% threshold
+            ..Default::default()
+        };
+        let result = m.evaluate_health(&q);
+        assert_eq!(result, LinkHealth::Degraded);
+    }
+
+    #[test]
+    fn healthy_to_critical_on_high_loss() {
+        let mut m = make_test_monitor();
+        m.health = LinkHealth::Healthy;
+        let q = ConnectionQuality {
+            loss_ratio: 0.25, // > 20% threshold
+            ..Default::default()
+        };
+        let result = m.evaluate_health(&q);
+        assert_eq!(result, LinkHealth::Critical);
+    }
+
+    #[test]
+    fn healthy_to_critical_on_consecutive_timeouts() {
+        let mut m = make_test_monitor();
+        m.health = LinkHealth::Healthy;
+        let q = ConnectionQuality {
+            consecutive_timeouts: 2,
+            ..Default::default()
+        };
+        let result = m.evaluate_health(&q);
+        assert_eq!(result, LinkHealth::Critical);
+    }
+
+    #[test]
+    fn degraded_to_healthy_requires_hysteresis() {
+        let mut m = make_test_monitor();
+        m.health = LinkHealth::Degraded;
+        let good_quality = ConnectionQuality {
+            jitter_ms: 10.0,
+            loss_ratio: 0.0,
+            consecutive_timeouts: 0,
+            srtt_ms: 20.0,
+            ..Default::default()
+        };
+
+        // Should require 3 consecutive good checks (default upgrade_checks)
+        assert_eq!(m.evaluate_health(&good_quality), LinkHealth::Degraded);
+        assert_eq!(m.consecutive_upgrade_checks, 1);
+        assert_eq!(m.evaluate_health(&good_quality), LinkHealth::Degraded);
+        assert_eq!(m.consecutive_upgrade_checks, 2);
+        assert_eq!(m.evaluate_health(&good_quality), LinkHealth::Healthy);
+    }
+
+    #[test]
+    fn degraded_to_healthy_resets_on_bad_check() {
+        let mut m = make_test_monitor();
+        m.health = LinkHealth::Degraded;
+        let good = ConnectionQuality {
+            jitter_ms: 10.0,
+            loss_ratio: 0.0,
+            consecutive_timeouts: 0,
+            ..Default::default()
+        };
+        let bad = ConnectionQuality {
+            jitter_ms: 60.0, // too high
+            loss_ratio: 0.0,
+            consecutive_timeouts: 0,
+            ..Default::default()
+        };
+
+        m.evaluate_health(&good); // 1 check
+        m.evaluate_health(&good); // 2 checks
+        m.evaluate_health(&bad);  // resets
+        assert_eq!(m.consecutive_upgrade_checks, 0);
+    }
+
+    #[test]
+    fn critical_to_degraded_requires_hysteresis() {
+        let mut m = make_test_monitor();
+        m.health = LinkHealth::Critical;
+        let recovering = ConnectionQuality {
+            loss_ratio: 0.05, // < 10% recover threshold
+            consecutive_timeouts: 0,
+            ..Default::default()
+        };
+
+        assert_eq!(m.evaluate_health(&recovering), LinkHealth::Critical);
+        assert_eq!(m.consecutive_upgrade_checks, 1);
+        assert_eq!(m.evaluate_health(&recovering), LinkHealth::Degraded);
+    }
+
+    #[test]
+    fn critical_never_directly_to_healthy() {
+        let mut m = make_test_monitor();
+        m.health = LinkHealth::Critical;
+        let perfect = ConnectionQuality {
+            jitter_ms: 1.0,
+            loss_ratio: 0.0,
+            consecutive_timeouts: 0,
+            srtt_ms: 10.0,
+            ..Default::default()
+        };
+
+        // Even with perfect quality, must go through Degraded first
+        m.evaluate_health(&perfect); // 1
+        let result = m.evaluate_health(&perfect); // 2 → Degraded
+        assert_eq!(result, LinkHealth::Degraded);
+        // Not Healthy yet
+    }
+
+    #[test]
+    fn degraded_to_critical_on_high_loss() {
+        let mut m = make_test_monitor();
+        m.health = LinkHealth::Degraded;
+        let q = ConnectionQuality {
+            loss_ratio: 0.25,
+            ..Default::default()
+        };
+        assert_eq!(m.evaluate_health(&q), LinkHealth::Critical);
+    }
+
+    #[test]
+    fn interval_matches_health() {
+        let mut m = make_test_monitor();
+        m.health = LinkHealth::Healthy;
+        assert_eq!(m.current_interval(), Duration::from_secs(60));
+        m.health = LinkHealth::Degraded;
+        assert_eq!(m.current_interval(), Duration::from_secs(30));
+        m.health = LinkHealth::Critical;
+        assert_eq!(m.current_interval(), Duration::from_secs(10));
+    }
+}

rust/src/lib.rs

@@ -5,9 +5,20 @@ pub mod management;
 pub mod codec;
 pub mod crypto;
 pub mod transport;
+pub mod transport_trait;
+pub mod quic_transport;
 pub mod keepalive;
 pub mod tunnel;
 pub mod network;
 pub mod server;
 pub mod client;
 pub mod reconnect;
+pub mod telemetry;
+pub mod ratelimit;
+pub mod qos;
+pub mod mtu;
+pub mod wireguard;
+pub mod client_registry;
+pub mod acl;
+pub mod proxy_protocol;
+pub mod userspace_nat;

rust/src/management.rs

@@ -7,6 +7,7 @@ use tracing::{info, error, warn};
 use crate::client::{ClientConfig, VpnClient};
 use crate::crypto;
 use crate::server::{ServerConfig, VpnServer};
+use crate::wireguard::{self, WgClient, WgClientConfig, WgPeerConfig, WgServer, WgServerConfig};
 
 // ============================================================================
 // IPC protocol types
@@ -93,6 +94,8 @@ pub async fn management_loop_stdio(mode: &str) -> Result<()> {
 
     let mut vpn_client = VpnClient::new();
     let mut vpn_server = VpnServer::new();
+    let mut wg_client = WgClient::new();
+    let mut wg_server = WgServer::new();
 
     send_event_stdout("ready", serde_json::json!({ "mode": mode }));
 
@@ -127,8 +130,8 @@ pub async fn management_loop_stdio(mode: &str) -> Result<()> {
         };
 
         let response = match mode {
-            "client" => handle_client_request(&request, &mut vpn_client).await,
+            "client" => handle_client_request(&request, &mut vpn_client, &mut wg_client).await,
-            "server" => handle_server_request(&request, &mut vpn_server).await,
+            "server" => handle_server_request(&request, &mut vpn_server, &mut wg_server).await,
             _ => ManagementResponse::err(request.id.clone(), format!("Unknown mode: {}", mode)),
         };
         send_response_stdout(&response);
@@ -150,6 +153,8 @@ pub async fn management_loop_socket(socket_path: &str, mode: &str) -> Result<()>
     // Shared state behind Mutex for socket mode (multiple connections)
     let vpn_client = std::sync::Arc::new(Mutex::new(VpnClient::new()));
     let vpn_server = std::sync::Arc::new(Mutex::new(VpnServer::new()));
+    let wg_client = std::sync::Arc::new(Mutex::new(WgClient::new()));
+    let wg_server = std::sync::Arc::new(Mutex::new(WgServer::new()));
 
     loop {
         match listener.accept().await {
@@ -157,9 +162,11 @@ pub async fn management_loop_socket(socket_path: &str, mode: &str) -> Result<()>
                 let mode = mode.to_string();
                 let client = vpn_client.clone();
                 let server = vpn_server.clone();
+                let wg_c = wg_client.clone();
+                let wg_s = wg_server.clone();
                 tokio::spawn(async move {
                     if let Err(e) =
-                        handle_socket_connection(stream, &mode, client, server).await
+                        handle_socket_connection(stream, &mode, client, server, wg_c, wg_s).await
                     {
                         warn!("Socket connection error: {}", e);
                     }
@@ -177,6 +184,8 @@ async fn handle_socket_connection(
     mode: &str,
     vpn_client: std::sync::Arc<Mutex<VpnClient>>,
     vpn_server: std::sync::Arc<Mutex<VpnServer>>,
+    wg_client: std::sync::Arc<Mutex<WgClient>>,
+    wg_server: std::sync::Arc<Mutex<WgServer>>,
 ) -> Result<()> {
     let (reader, mut writer) = stream.into_split();
     let buf_reader = BufReader::new(reader);
@@ -227,11 +236,13 @@ async fn handle_socket_connection(
         let response = match mode {
             "client" => {
                 let mut client = vpn_client.lock().await;
-                handle_client_request(&request, &mut client).await
+                let mut wg_c = wg_client.lock().await;
+                handle_client_request(&request, &mut client, &mut wg_c).await
             }
             "server" => {
                 let mut server = vpn_server.lock().await;
-                handle_server_request(&request, &mut server).await
+                let mut wg_s = wg_server.lock().await;
+                handle_server_request(&request, &mut server, &mut wg_s).await
             }
             _ => ManagementResponse::err(request.id.clone(), format!("Unknown mode: {}", mode)),
         };
@@ -252,38 +263,112 @@ async fn handle_socket_connection(
 async fn handle_client_request(
     request: &ManagementRequest,
     vpn_client: &mut VpnClient,
+    wg_client: &mut WgClient,
 ) -> ManagementResponse {
     let id = request.id.clone();
 
     match request.method.as_str() {
         "connect" => {
-            let config: ClientConfig = match serde_json::from_value(
+            // Check if transport is "wireguard"
-                request.params.get("config").cloned().unwrap_or_default(),
+            let transport = request.params
-            ) {
+                .get("config")
-                Ok(c) => c,
+                .and_then(|c| c.get("transport"))
-                Err(e) => {
+                .and_then(|t| t.as_str())
-                    return ManagementResponse::err(id, format!("Invalid config: {}", e));
+                .unwrap_or("");
-                }
-            };
 
-            match vpn_client.connect(config).await {
+            if transport == "wireguard" {
-                Ok(assigned_ip) => {
+                let config: WgClientConfig = match serde_json::from_value(
-                    ManagementResponse::ok(id, serde_json::json!({ "assignedIp": assigned_ip }))
+                    request.params.get("config").cloned().unwrap_or_default(),
+                ) {
+                    Ok(c) => c,
+                    Err(e) => {
+                        return ManagementResponse::err(id, format!("Invalid WG config: {}", e));
+                    }
+                };
+                match wg_client.connect(config).await {
+                    Ok(assigned_ip) => {
+                        ManagementResponse::ok(id, serde_json::json!({ "assignedIp": assigned_ip }))
+                    }
+                    Err(e) => ManagementResponse::err(id, format!("WG connect failed: {}", e)),
+                }
+            } else {
+                let config: ClientConfig = match serde_json::from_value(
+                    request.params.get("config").cloned().unwrap_or_default(),
+                ) {
+                    Ok(c) => c,
+                    Err(e) => {
+                        return ManagementResponse::err(id, format!("Invalid config: {}", e));
+                    }
+                };
+                match vpn_client.connect(config).await {
+                    Ok(assigned_ip) => {
+                        ManagementResponse::ok(id, serde_json::json!({ "assignedIp": assigned_ip }))
+                    }
+                    Err(e) => ManagementResponse::err(id, format!("Connect failed: {}", e)),
+                }
+            }
+        }
+        "disconnect" => {
+            if wg_client.is_running() {
+                match wg_client.disconnect().await {
+                    Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                    Err(e) => ManagementResponse::err(id, format!("WG disconnect failed: {}", e)),
+                }
+            } else {
+                match vpn_client.disconnect().await {
+                    Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                    Err(e) => ManagementResponse::err(id, format!("Disconnect failed: {}", e)),
                 }
-                Err(e) => ManagementResponse::err(id, format!("Connect failed: {}", e)),
             }
         }
-        "disconnect" => match vpn_client.disconnect().await {
-            Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
-            Err(e) => ManagementResponse::err(id, format!("Disconnect failed: {}", e)),
-        },
         "getStatus" => {
-            let status = vpn_client.get_status().await;
+            if wg_client.is_running() {
-            ManagementResponse::ok(id, status)
+                ManagementResponse::ok(id, wg_client.get_status().await)
+            } else {
+                let status = vpn_client.get_status().await;
+                ManagementResponse::ok(id, status)
+            }
         }
         "getStatistics" => {
-            let stats = vpn_client.get_statistics().await;
+            if wg_client.is_running() {
-            ManagementResponse::ok(id, stats)
+                ManagementResponse::ok(id, wg_client.get_statistics().await)
+            } else {
+                let stats = vpn_client.get_statistics().await;
+                ManagementResponse::ok(id, stats)
+            }
+        }
+        "getConnectionQuality" => {
+            match vpn_client.get_connection_quality() {
+                Some(quality) => {
+                    let health = vpn_client.get_link_health().await;
+                    let interval_secs = match health {
+                        crate::keepalive::LinkHealth::Healthy => 60,
+                        crate::keepalive::LinkHealth::Degraded => 30,
+                        crate::keepalive::LinkHealth::Critical => 10,
+                    };
+                    ManagementResponse::ok(id, serde_json::json!({
+                        "srttMs": quality.srtt_ms,
+                        "jitterMs": quality.jitter_ms,
+                        "minRttMs": quality.min_rtt_ms,
+                        "maxRttMs": quality.max_rtt_ms,
+                        "lossRatio": quality.loss_ratio,
+                        "consecutiveTimeouts": quality.consecutive_timeouts,
+                        "linkHealth": format!("{}", health),
+                        "currentKeepaliveIntervalSecs": interval_secs,
+                    }))
+                }
+                None => ManagementResponse::ok(id, serde_json::json!(null)),
+            }
+        }
+        "getMtuInfo" => {
+            ManagementResponse::ok(id, serde_json::json!({
+                "tunMtu": 1420,
+                "effectiveMtu": crate::mtu::TunnelOverhead::default_overhead().effective_tun_mtu(1500),
+                "linkMtu": 1500,
+                "overheadBytes": crate::mtu::TunnelOverhead::default_overhead().total(),
+                "oversizedPacketsDropped": 0,
+                "icmpTooBigSent": 0,
+            }))
         }
         _ => ManagementResponse::err(id, format!("Unknown client method: {}", request.method)),
     }
@@ -296,45 +381,92 @@ async fn handle_client_request(
 async fn handle_server_request(
     request: &ManagementRequest,
     vpn_server: &mut VpnServer,
+    wg_server: &mut WgServer,
 ) -> ManagementResponse {
     let id = request.id.clone();
 
     match request.method.as_str() {
         "start" => {
-            let config: ServerConfig = match serde_json::from_value(
+            // Check if transportMode is "wireguard"
-                request.params.get("config").cloned().unwrap_or_default(),
+            let transport_mode = request.params
-            ) {
+                .get("config")
-                Ok(c) => c,
+                .and_then(|c| c.get("transportMode"))
-                Err(e) => {
+                .and_then(|t| t.as_str())
-                    return ManagementResponse::err(id, format!("Invalid config: {}", e));
+                .unwrap_or("");
-                }
-            };
 
-            match vpn_server.start(config).await {
+            if transport_mode == "wireguard" {
-                Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                let config: WgServerConfig = match serde_json::from_value(
-                Err(e) => ManagementResponse::err(id, format!("Start failed: {}", e)),
+                    request.params.get("config").cloned().unwrap_or_default(),
+                ) {
+                    Ok(c) => c,
+                    Err(e) => {
+                        return ManagementResponse::err(id, format!("Invalid WG config: {}", e));
+                    }
+                };
+                match wg_server.start(config).await {
+                    Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                    Err(e) => ManagementResponse::err(id, format!("WG start failed: {}", e)),
+                }
+            } else {
+                let config: ServerConfig = match serde_json::from_value(
+                    request.params.get("config").cloned().unwrap_or_default(),
+                ) {
+                    Ok(c) => c,
+                    Err(e) => {
+                        return ManagementResponse::err(id, format!("Invalid config: {}", e));
+                    }
+                };
+                match vpn_server.start(config).await {
+                    Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                    Err(e) => ManagementResponse::err(id, format!("Start failed: {}", e)),
+                }
+            }
+        }
+        "stop" => {
+            if wg_server.is_running() {
+                match wg_server.stop().await {
+                    Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                    Err(e) => ManagementResponse::err(id, format!("WG stop failed: {}", e)),
+                }
+            } else {
+                match vpn_server.stop().await {
+                    Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                    Err(e) => ManagementResponse::err(id, format!("Stop failed: {}", e)),
+                }
             }
         }
-        "stop" => match vpn_server.stop().await {
-            Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
-            Err(e) => ManagementResponse::err(id, format!("Stop failed: {}", e)),
-        },
         "getStatus" => {
-            let status = vpn_server.get_status();
+            if wg_server.is_running() {
-            ManagementResponse::ok(id, status)
+                ManagementResponse::ok(id, wg_server.get_status())
+            } else {
+                let status = vpn_server.get_status();
+                ManagementResponse::ok(id, status)
+            }
         }
         "getStatistics" => {
-            let stats = vpn_server.get_statistics().await;
+            if wg_server.is_running() {
-            match serde_json::to_value(&stats) {
+                ManagementResponse::ok(id, wg_server.get_statistics().await)
-                Ok(v) => ManagementResponse::ok(id, v),
+            } else {
-                Err(e) => ManagementResponse::err(id, format!("Serialize error: {}", e)),
+                let stats = vpn_server.get_statistics().await;
+                match serde_json::to_value(&stats) {
+                    Ok(v) => ManagementResponse::ok(id, v),
+                    Err(e) => ManagementResponse::err(id, format!("Serialize error: {}", e)),
+                }
             }
         }
         "listClients" => {
-            let clients = vpn_server.list_clients().await;
+            if wg_server.is_running() {
-            match serde_json::to_value(&clients) {
+                let peers = wg_server.list_peers().await;
-                Ok(v) => ManagementResponse::ok(id, serde_json::json!({ "clients": v })),
+                match serde_json::to_value(&peers) {
-                Err(e) => ManagementResponse::err(id, format!("Serialize error: {}", e)),
+                    Ok(v) => ManagementResponse::ok(id, serde_json::json!({ "clients": v })),
+                    Err(e) => ManagementResponse::err(id, format!("Serialize error: {}", e)),
+                }
+            } else {
+                let clients = vpn_server.list_clients().await;
+                match serde_json::to_value(&clients) {
+                    Ok(v) => ManagementResponse::ok(id, serde_json::json!({ "clients": v })),
+                    Err(e) => ManagementResponse::err(id, format!("Serialize error: {}", e)),
+                }
             }
         }
         "disconnectClient" => {
@@ -349,6 +481,50 @@ async fn handle_server_request(
                 Err(e) => ManagementResponse::err(id, format!("Disconnect client failed: {}", e)),
             }
         }
+        "setClientRateLimit" => {
+            let client_id = match request.params.get("clientId").and_then(|v| v.as_str()) {
+                Some(id) => id.to_string(),
+                None => return ManagementResponse::err(id, "Missing clientId".to_string()),
+            };
+            let rate = match request.params.get("rateBytesPerSec").and_then(|v| v.as_u64()) {
+                Some(r) => r,
+                None => return ManagementResponse::err(id, "Missing rateBytesPerSec".to_string()),
+            };
+            let burst = match request.params.get("burstBytes").and_then(|v| v.as_u64()) {
+                Some(b) => b,
+                None => return ManagementResponse::err(id, "Missing burstBytes".to_string()),
+            };
+            match vpn_server.set_client_rate_limit(&client_id, rate, burst).await {
+                Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                Err(e) => ManagementResponse::err(id, format!("Failed: {}", e)),
+            }
+        }
+        "removeClientRateLimit" => {
+            let client_id = match request.params.get("clientId").and_then(|v| v.as_str()) {
+                Some(id) => id.to_string(),
+                None => return ManagementResponse::err(id, "Missing clientId".to_string()),
+            };
+            match vpn_server.remove_client_rate_limit(&client_id).await {
+                Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                Err(e) => ManagementResponse::err(id, format!("Failed: {}", e)),
+            }
+        }
+        "getClientTelemetry" => {
+            let client_id = match request.params.get("clientId").and_then(|v| v.as_str()) {
+                Some(cid) => cid.to_string(),
+                None => return ManagementResponse::err(id, "Missing clientId".to_string()),
+            };
+            let clients = vpn_server.list_clients().await;
+            match clients.into_iter().find(|c| c.client_id == client_id) {
+                Some(info) => {
+                    match serde_json::to_value(&info) {
+                        Ok(v) => ManagementResponse::ok(id, v),
+                        Err(e) => ManagementResponse::err(id, format!("Serialize error: {}", e)),
+                    }
+                }
+                None => ManagementResponse::err(id, format!("Client {} not found", client_id)),
+            }
+        }
         "generateKeypair" => match crypto::generate_keypair() {
             Ok((public_key, private_key)) => ManagementResponse::ok(
                 id,
@@ -359,6 +535,153 @@ async fn handle_server_request(
             ),
             Err(e) => ManagementResponse::err(id, format!("Keypair generation failed: {}", e)),
         },
+        "generateWgKeypair" => {
+            let (public_key, private_key) = wireguard::generate_wg_keypair();
+            ManagementResponse::ok(
+                id,
+                serde_json::json!({
+                    "publicKey": public_key,
+                    "privateKey": private_key,
+                }),
+            )
+        }
+        "addWgPeer" => {
+            if !wg_server.is_running() {
+                return ManagementResponse::err(id, "WireGuard server not running".to_string());
+            }
+            let config: WgPeerConfig = match serde_json::from_value(
+                request.params.get("peer").cloned().unwrap_or_default(),
+            ) {
+                Ok(c) => c,
+                Err(e) => {
+                    return ManagementResponse::err(id, format!("Invalid peer config: {}", e));
+                }
+            };
+            match wg_server.add_peer(config).await {
+                Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                Err(e) => ManagementResponse::err(id, format!("Add peer failed: {}", e)),
+            }
+        }
+        "removeWgPeer" => {
+            if !wg_server.is_running() {
+                return ManagementResponse::err(id, "WireGuard server not running".to_string());
+            }
+            let public_key = match request.params.get("publicKey").and_then(|v| v.as_str()) {
+                Some(k) => k.to_string(),
+                None => return ManagementResponse::err(id, "Missing publicKey".to_string()),
+            };
+            match wg_server.remove_peer(&public_key).await {
+                Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                Err(e) => ManagementResponse::err(id, format!("Remove peer failed: {}", e)),
+            }
+        }
+        "listWgPeers" => {
+            if !wg_server.is_running() {
+                return ManagementResponse::err(id, "WireGuard server not running".to_string());
+            }
+            let peers = wg_server.list_peers().await;
+            match serde_json::to_value(&peers) {
+                Ok(v) => ManagementResponse::ok(id, serde_json::json!({ "peers": v })),
+                Err(e) => ManagementResponse::err(id, format!("Serialize error: {}", e)),
+            }
+        }
+        // ── Client Registry (Hub) Commands ────────────────────────────────
+        "createClient" => {
+            let client_partial = request.params.get("client").cloned().unwrap_or_default();
+            match vpn_server.create_client(client_partial).await {
+                Ok(bundle) => ManagementResponse::ok(id, bundle),
+                Err(e) => ManagementResponse::err(id, format!("Create client failed: {}", e)),
+            }
+        }
+        "removeClient" => {
+            let client_id = match request.params.get("clientId").and_then(|v| v.as_str()) {
+                Some(cid) => cid.to_string(),
+                None => return ManagementResponse::err(id, "Missing clientId".to_string()),
+            };
+            match vpn_server.remove_registered_client(&client_id).await {
+                Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                Err(e) => ManagementResponse::err(id, format!("Remove client failed: {}", e)),
+            }
+        }
+        "getClient" => {
+            let client_id = match request.params.get("clientId").and_then(|v| v.as_str()) {
+                Some(cid) => cid.to_string(),
+                None => return ManagementResponse::err(id, "Missing clientId".to_string()),
+            };
+            match vpn_server.get_registered_client(&client_id).await {
+                Ok(entry) => ManagementResponse::ok(id, entry),
+                Err(e) => ManagementResponse::err(id, format!("Get client failed: {}", e)),
+            }
+        }
+        "listRegisteredClients" => {
+            let clients = vpn_server.list_registered_clients().await;
+            match serde_json::to_value(&clients) {
+                Ok(v) => ManagementResponse::ok(id, serde_json::json!({ "clients": v })),
+                Err(e) => ManagementResponse::err(id, format!("Serialize error: {}", e)),
+            }
+        }
+        "updateClient" => {
+            let client_id = match request.params.get("clientId").and_then(|v| v.as_str()) {
+                Some(cid) => cid.to_string(),
+                None => return ManagementResponse::err(id, "Missing clientId".to_string()),
+            };
+            let update = request.params.get("update").cloned().unwrap_or_default();
+            match vpn_server.update_registered_client(&client_id, update).await {
+                Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                Err(e) => ManagementResponse::err(id, format!("Update client failed: {}", e)),
+            }
+        }
+        "enableClient" => {
+            let client_id = match request.params.get("clientId").and_then(|v| v.as_str()) {
+                Some(cid) => cid.to_string(),
+                None => return ManagementResponse::err(id, "Missing clientId".to_string()),
+            };
+            match vpn_server.enable_client(&client_id).await {
+                Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                Err(e) => ManagementResponse::err(id, format!("Enable client failed: {}", e)),
+            }
+        }
+        "disableClient" => {
+            let client_id = match request.params.get("clientId").and_then(|v| v.as_str()) {
+                Some(cid) => cid.to_string(),
+                None => return ManagementResponse::err(id, "Missing clientId".to_string()),
+            };
+            match vpn_server.disable_client(&client_id).await {
+                Ok(()) => ManagementResponse::ok(id, serde_json::json!({})),
+                Err(e) => ManagementResponse::err(id, format!("Disable client failed: {}", e)),
+            }
+        }
+        "rotateClientKey" => {
+            let client_id = match request.params.get("clientId").and_then(|v| v.as_str()) {
+                Some(cid) => cid.to_string(),
+                None => return ManagementResponse::err(id, "Missing clientId".to_string()),
+            };
+            match vpn_server.rotate_client_key(&client_id).await {
+                Ok(bundle) => ManagementResponse::ok(id, bundle),
+                Err(e) => ManagementResponse::err(id, format!("Key rotation failed: {}", e)),
+            }
+        }
+        "exportClientConfig" => {
+            let client_id = match request.params.get("clientId").and_then(|v| v.as_str()) {
+                Some(cid) => cid.to_string(),
+                None => return ManagementResponse::err(id, "Missing clientId".to_string()),
+            };
+            let format = request.params.get("format").and_then(|v| v.as_str()).unwrap_or("smartvpn");
+            match vpn_server.export_client_config(&client_id, format).await {
+                Ok(config) => ManagementResponse::ok(id, config),
+                Err(e) => ManagementResponse::err(id, format!("Export failed: {}", e)),
+            }
+        }
+        "generateClientKeypair" => match crypto::generate_keypair() {
+            Ok((public_key, private_key)) => ManagementResponse::ok(
+                id,
+                serde_json::json!({
+                    "publicKey": public_key,
+                    "privateKey": private_key,
+                }),
+            ),
+            Err(e) => ManagementResponse::err(id, format!("Keypair generation failed: {}", e)),
+        },
         _ => ManagementResponse::err(id, format!("Unknown server method: {}", request.method)),
     }
 }

rust/src/mtu.rs

@@ -0,0 +1,314 @@
+use std::net::Ipv4Addr;
+
+/// Overhead breakdown for VPN tunnel encapsulation.
+#[derive(Debug, Clone)]
+pub struct TunnelOverhead {
+    /// Outer IP header: 20 bytes (IPv4, no options).
+    pub ip_header: u16,
+    /// TCP header: typically 32 bytes (20 base + 12 for timestamps).
+    pub tcp_header: u16,
+    /// WebSocket framing: ~6 bytes (2 base + 4 mask from client).
+    pub ws_framing: u16,
+    /// VPN binary frame header: 5 bytes [type:1B][length:4B].
+    pub vpn_header: u16,
+    /// Noise AEAD tag: 16 bytes (Poly1305).
+    pub noise_tag: u16,
+}
+
+impl TunnelOverhead {
+    /// Conservative default overhead estimate.
+    pub fn default_overhead() -> Self {
+        Self {
+            ip_header: 20,
+            tcp_header: 32,
+            ws_framing: 6,
+            vpn_header: 5,
+            noise_tag: 16,
+        }
+    }
+
+    /// Total encapsulation overhead in bytes.
+    pub fn total(&self) -> u16 {
+        self.ip_header + self.tcp_header + self.ws_framing + self.vpn_header + self.noise_tag
+    }
+
+    /// Compute effective TUN MTU given the underlying link MTU.
+    pub fn effective_tun_mtu(&self, link_mtu: u16) -> u16 {
+        link_mtu.saturating_sub(self.total())
+    }
+}
+
+/// MTU configuration for the VPN tunnel.
+#[derive(Debug, Clone)]
+pub struct MtuConfig {
+    /// Underlying link MTU (typically 1500 for Ethernet).
+    pub link_mtu: u16,
+    /// Computed effective TUN MTU.
+    pub effective_mtu: u16,
+    /// Whether to generate ICMP too-big for oversized packets.
+    pub send_icmp_too_big: bool,
+    /// Counter: oversized packets encountered.
+    pub oversized_packets: u64,
+    /// Counter: ICMP too-big messages generated.
+    pub icmp_too_big_sent: u64,
+}
+
+impl MtuConfig {
+    /// Create a new MTU config from the underlying link MTU.
+    pub fn new(link_mtu: u16) -> Self {
+        let overhead = TunnelOverhead::default_overhead();
+        let effective = overhead.effective_tun_mtu(link_mtu);
+        Self {
+            link_mtu,
+            effective_mtu: effective,
+            send_icmp_too_big: true,
+            oversized_packets: 0,
+            icmp_too_big_sent: 0,
+        }
+    }
+
+    /// Check if a packet exceeds the effective MTU.
+    pub fn is_oversized(&self, packet_len: usize) -> bool {
+        packet_len > self.effective_mtu as usize
+    }
+}
+
+/// Action to take after checking MTU.
+pub enum MtuAction {
+    /// Packet is within MTU, forward normally.
+    Forward,
+    /// Packet is oversized; contains the ICMP too-big message to write back into TUN.
+    SendIcmpTooBig(Vec<u8>),
+}
+
+/// Check packet against MTU config and return the appropriate action.
+pub fn check_mtu(packet: &[u8], config: &MtuConfig) -> MtuAction {
+    if !config.is_oversized(packet.len()) {
+        return MtuAction::Forward;
+    }
+
+    if !config.send_icmp_too_big {
+        return MtuAction::Forward;
+    }
+
+    match generate_icmp_too_big(packet, config.effective_mtu) {
+        Some(icmp) => MtuAction::SendIcmpTooBig(icmp),
+        None => MtuAction::Forward,
+    }
+}
+
+/// Generate an ICMPv4 Destination Unreachable / Fragmentation Needed message.
+///
+/// Per RFC 792: Type 3, Code 4, with next-hop MTU in bytes 6-7 (RFC 1191).
+/// Returns the complete IP + ICMP packet to write back into the TUN device.
+pub fn generate_icmp_too_big(original_packet: &[u8], next_hop_mtu: u16) -> Option<Vec<u8>> {
+    // Need at least 20 bytes of original IP header
+    if original_packet.len() < 20 {
+        return None;
+    }
+
+    // Verify it's IPv4
+    if original_packet[0] >> 4 != 4 {
+        return None;
+    }
+
+    // Parse source/dest from original IP header
+    let src_ip = Ipv4Addr::new(
+        original_packet[12],
+        original_packet[13],
+        original_packet[14],
+        original_packet[15],
+    );
+    let dst_ip = Ipv4Addr::new(
+        original_packet[16],
+        original_packet[17],
+        original_packet[18],
+        original_packet[19],
+    );
+
+    // ICMP payload: IP header + first 8 bytes of original datagram (per RFC 792)
+    let icmp_data_len = original_packet.len().min(28); // 20 IP header + 8 bytes
+    let icmp_payload = &original_packet[..icmp_data_len];
+
+    // Build ICMP message: type(1) + code(1) + checksum(2) + unused(2) + next_hop_mtu(2) + data
+    let mut icmp = Vec::with_capacity(8 + icmp_data_len);
+    icmp.push(3); // Type: Destination Unreachable
+    icmp.push(4); // Code: Fragmentation Needed and DF was Set
+    icmp.push(0); // Checksum placeholder
+    icmp.push(0);
+    icmp.push(0); // Unused
+    icmp.push(0);
+    icmp.extend_from_slice(&next_hop_mtu.to_be_bytes());
+    icmp.extend_from_slice(icmp_payload);
+
+    // Compute ICMP checksum
+    let cksum = internet_checksum(&icmp);
+    icmp[2] = (cksum >> 8) as u8;
+    icmp[3] = (cksum & 0xff) as u8;
+
+    // Build IP header (ICMP response: FROM tunnel gateway TO original source)
+    let total_len = (20 + icmp.len()) as u16;
+    let mut ip = Vec::with_capacity(total_len as usize);
+    ip.push(0x45); // Version 4, IHL 5
+    ip.push(0x00); // DSCP/ECN
+    ip.extend_from_slice(&total_len.to_be_bytes());
+    ip.extend_from_slice(&[0, 0]); // Identification
+    ip.extend_from_slice(&[0x40, 0x00]); // Flags: Don't Fragment, Fragment Offset: 0
+    ip.push(64); // TTL
+    ip.push(1); // Protocol: ICMP
+    ip.extend_from_slice(&[0, 0]); // Header checksum placeholder
+    ip.extend_from_slice(&dst_ip.octets()); // Source: tunnel endpoint (was dst)
+    ip.extend_from_slice(&src_ip.octets()); // Destination: original source
+
+    // Compute IP header checksum
+    let ip_cksum = internet_checksum(&ip[..20]);
+    ip[10] = (ip_cksum >> 8) as u8;
+    ip[11] = (ip_cksum & 0xff) as u8;
+
+    ip.extend_from_slice(&icmp);
+    Some(ip)
+}
+
+/// Standard Internet checksum (RFC 1071).
+fn internet_checksum(data: &[u8]) -> u16 {
+    let mut sum: u32 = 0;
+    let mut i = 0;
+    while i + 1 < data.len() {
+        sum += u16::from_be_bytes([data[i], data[i + 1]]) as u32;
+        i += 2;
+    }
+    if i < data.len() {
+        sum += (data[i] as u32) << 8;
+    }
+    while sum >> 16 != 0 {
+        sum = (sum & 0xFFFF) + (sum >> 16);
+    }
+    !sum as u16
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn default_overhead_total() {
+        let oh = TunnelOverhead::default_overhead();
+        assert_eq!(oh.total(), 79); // 20+32+6+5+16
+    }
+
+    #[test]
+    fn effective_mtu_for_ethernet() {
+        let oh = TunnelOverhead::default_overhead();
+        let mtu = oh.effective_tun_mtu(1500);
+        assert_eq!(mtu, 1421); // 1500 - 79
+    }
+
+    #[test]
+    fn effective_mtu_saturates_at_zero() {
+        let oh = TunnelOverhead::default_overhead();
+        let mtu = oh.effective_tun_mtu(50); // Less than overhead
+        assert_eq!(mtu, 0);
+    }
+
+    #[test]
+    fn mtu_config_default() {
+        let config = MtuConfig::new(1500);
+        assert_eq!(config.effective_mtu, 1421);
+        assert_eq!(config.link_mtu, 1500);
+        assert!(config.send_icmp_too_big);
+    }
+
+    #[test]
+    fn is_oversized() {
+        let config = MtuConfig::new(1500);
+        assert!(!config.is_oversized(1421));
+        assert!(config.is_oversized(1422));
+    }
+
+    #[test]
+    fn icmp_too_big_generation() {
+        // Craft a minimal IPv4 packet
+        let mut original = vec![0u8; 28];
+        original[0] = 0x45; // version 4, IHL 5
+        original[2..4].copy_from_slice(&1500u16.to_be_bytes()); // total length
+        original[9] = 6; // TCP
+        original[12..16].copy_from_slice(&[10, 0, 0, 1]); // src IP
+        original[16..20].copy_from_slice(&[10, 0, 0, 2]); // dst IP
+
+        let icmp_pkt = generate_icmp_too_big(&original, 1421).unwrap();
+
+        // Verify it's a valid IPv4 packet
+        assert_eq!(icmp_pkt[0] >> 4, 4); // IPv4
+        assert_eq!(icmp_pkt[9], 1); // ICMP protocol
+
+        // Source should be original dst (10.0.0.2)
+        assert_eq!(&icmp_pkt[12..16], &[10, 0, 0, 2]);
+        // Destination should be original src (10.0.0.1)
+        assert_eq!(&icmp_pkt[16..20], &[10, 0, 0, 1]);
+
+        // ICMP type 3, code 4
+        assert_eq!(icmp_pkt[20], 3);
+        assert_eq!(icmp_pkt[21], 4);
+
+        // Next-hop MTU at ICMP bytes 6-7 (offset 26-27 in IP packet)
+        let mtu = u16::from_be_bytes([icmp_pkt[26], icmp_pkt[27]]);
+        assert_eq!(mtu, 1421);
+    }
+
+    #[test]
+    fn icmp_too_big_rejects_short_packet() {
+        let short = vec![0u8; 10];
+        assert!(generate_icmp_too_big(&short, 1421).is_none());
+    }
+
+    #[test]
+    fn icmp_too_big_rejects_non_ipv4() {
+        let mut pkt = vec![0u8; 40];
+        pkt[0] = 0x60; // IPv6
+        assert!(generate_icmp_too_big(&pkt, 1421).is_none());
+    }
+
+    #[test]
+    fn icmp_checksum_valid() {
+        let mut original = vec![0u8; 28];
+        original[0] = 0x45;
+        original[2..4].copy_from_slice(&1500u16.to_be_bytes());
+        original[9] = 6;
+        original[12..16].copy_from_slice(&[192, 168, 1, 100]);
+        original[16..20].copy_from_slice(&[10, 8, 0, 1]);
+
+        let icmp_pkt = generate_icmp_too_big(&original, 1420).unwrap();
+
+        // Verify IP header checksum
+        let ip_cksum = internet_checksum(&icmp_pkt[..20]);
+        assert_eq!(ip_cksum, 0, "IP header checksum should verify to 0");
+
+        // Verify ICMP checksum
+        let icmp_cksum = internet_checksum(&icmp_pkt[20..]);
+        assert_eq!(icmp_cksum, 0, "ICMP checksum should verify to 0");
+    }
+
+    #[test]
+    fn check_mtu_forward() {
+        let config = MtuConfig::new(1500);
+        let pkt = vec![0u8; 1421]; // Exactly at MTU
+        assert!(matches!(check_mtu(&pkt, &config), MtuAction::Forward));
+    }
+
+    #[test]
+    fn check_mtu_oversized_generates_icmp() {
+        let config = MtuConfig::new(1500);
+        let mut pkt = vec![0u8; 1500];
+        pkt[0] = 0x45; // Valid IPv4
+        pkt[12..16].copy_from_slice(&[10, 0, 0, 1]);
+        pkt[16..20].copy_from_slice(&[10, 0, 0, 2]);
+
+        match check_mtu(&pkt, &config) {
+            MtuAction::SendIcmpTooBig(icmp) => {
+                assert_eq!(icmp[20], 3); // ICMP type
+                assert_eq!(icmp[21], 4); // ICMP code
+            }
+            MtuAction::Forward => panic!("Expected SendIcmpTooBig"),
+        }
+    }
+}

rust/src/proxy_protocol.rs

@@ -0,0 +1,261 @@
+//! PROXY protocol v2 parser for extracting real client addresses
+//! when SmartVPN sits behind a reverse proxy (HAProxy, SmartProxy, etc.).
+//!
+//! Spec: <https://www.haproxy.org/download/2.9/doc/proxy-protocol.txt>
+
+use anyhow::Result;
+use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};
+use std::time::Duration;
+use tokio::io::AsyncReadExt;
+use tokio::net::TcpStream;
+
+/// Timeout for reading the PROXY protocol header from a new connection.
+const PROXY_HEADER_TIMEOUT: Duration = Duration::from_secs(5);
+
+/// The 12-byte PP v2 signature.
+const PP_V2_SIGNATURE: [u8; 12] = [
+    0x0D, 0x0A, 0x0D, 0x0A, 0x00, 0x0D, 0x0A, 0x51, 0x55, 0x49, 0x54, 0x0A,
+];
+
+/// Parsed PROXY protocol v2 header.
+#[derive(Debug, Clone)]
+pub struct ProxyHeader {
+    /// Real client source address.
+    pub src_addr: SocketAddr,
+    /// Proxy-to-server destination address.
+    pub dst_addr: SocketAddr,
+    /// True if this is a LOCAL command (health check probe from proxy).
+    pub is_local: bool,
+}
+
+/// Read and parse a PROXY protocol v2 header from a TCP stream.
+///
+/// Reads exactly the header bytes — the stream is in a clean state for
+/// WebSocket upgrade afterward. Returns an error on timeout, invalid
+/// signature, or malformed header.
+pub async fn read_proxy_header(stream: &mut TcpStream) -> Result<ProxyHeader> {
+    tokio::time::timeout(PROXY_HEADER_TIMEOUT, read_proxy_header_inner(stream))
+        .await
+        .map_err(|_| anyhow::anyhow!("PROXY protocol header read timed out ({}s)", PROXY_HEADER_TIMEOUT.as_secs()))?
+}
+
+async fn read_proxy_header_inner(stream: &mut TcpStream) -> Result<ProxyHeader> {
+    // Read the 16-byte fixed prefix
+    let mut prefix = [0u8; 16];
+    stream.read_exact(&mut prefix).await?;
+
+    // Validate the 12-byte signature
+    if prefix[..12] != PP_V2_SIGNATURE {
+        anyhow::bail!("Invalid PROXY protocol v2 signature");
+    }
+
+    // Byte 12: version (high nibble) | command (low nibble)
+    let version = (prefix[12] & 0xF0) >> 4;
+    let command = prefix[12] & 0x0F;
+
+    if version != 2 {
+        anyhow::bail!("Unsupported PROXY protocol version: {}", version);
+    }
+
+    // Byte 13: address family (high nibble) | protocol (low nibble)
+    let addr_family = (prefix[13] & 0xF0) >> 4;
+    let _protocol = prefix[13] & 0x0F; // 1 = STREAM (TCP)
+
+    // Bytes 14-15: address data length (big-endian)
+    let addr_len = u16::from_be_bytes([prefix[14], prefix[15]]) as usize;
+
+    // Read the address data
+    let mut addr_data = vec![0u8; addr_len];
+    if addr_len > 0 {
+        stream.read_exact(&mut addr_data).await?;
+    }
+
+    // LOCAL command (0x00) = health check, no real address
+    if command == 0x00 {
+        return Ok(ProxyHeader {
+            src_addr: SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::UNSPECIFIED, 0)),
+            dst_addr: SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::UNSPECIFIED, 0)),
+            is_local: true,
+        });
+    }
+
+    // PROXY command (0x01) — parse address block
+    if command != 0x01 {
+        anyhow::bail!("Unknown PROXY protocol command: {}", command);
+    }
+
+    match addr_family {
+        // AF_INET (IPv4): 4 src + 4 dst + 2 src_port + 2 dst_port = 12 bytes
+        1 => {
+            if addr_data.len() < 12 {
+                anyhow::bail!("IPv4 address block too short: {} bytes", addr_data.len());
+            }
+            let src_ip = Ipv4Addr::new(addr_data[0], addr_data[1], addr_data[2], addr_data[3]);
+            let dst_ip = Ipv4Addr::new(addr_data[4], addr_data[5], addr_data[6], addr_data[7]);
+            let src_port = u16::from_be_bytes([addr_data[8], addr_data[9]]);
+            let dst_port = u16::from_be_bytes([addr_data[10], addr_data[11]]);
+            Ok(ProxyHeader {
+                src_addr: SocketAddr::V4(SocketAddrV4::new(src_ip, src_port)),
+                dst_addr: SocketAddr::V4(SocketAddrV4::new(dst_ip, dst_port)),
+                is_local: false,
+            })
+        }
+        // AF_INET6 (IPv6): 16 src + 16 dst + 2 src_port + 2 dst_port = 36 bytes
+        2 => {
+            if addr_data.len() < 36 {
+                anyhow::bail!("IPv6 address block too short: {} bytes", addr_data.len());
+            }
+            let src_ip = Ipv6Addr::from(<[u8; 16]>::try_from(&addr_data[0..16]).unwrap());
+            let dst_ip = Ipv6Addr::from(<[u8; 16]>::try_from(&addr_data[16..32]).unwrap());
+            let src_port = u16::from_be_bytes([addr_data[32], addr_data[33]]);
+            let dst_port = u16::from_be_bytes([addr_data[34], addr_data[35]]);
+            Ok(ProxyHeader {
+                src_addr: SocketAddr::V6(SocketAddrV6::new(src_ip, src_port, 0, 0)),
+                dst_addr: SocketAddr::V6(SocketAddrV6::new(dst_ip, dst_port, 0, 0)),
+                is_local: false,
+            })
+        }
+        // AF_UNSPEC or unknown
+        _ => {
+            anyhow::bail!("Unsupported address family: {}", addr_family);
+        }
+    }
+}
+
+/// Build a PROXY protocol v2 header (for testing / proxy implementations).
+pub fn build_pp_v2_header(src: SocketAddr, dst: SocketAddr) -> Vec<u8> {
+    let mut buf = Vec::new();
+    buf.extend_from_slice(&PP_V2_SIGNATURE);
+
+    match (src, dst) {
+        (SocketAddr::V4(s), SocketAddr::V4(d)) => {
+            buf.push(0x21); // version 2 | PROXY command
+            buf.push(0x11); // AF_INET | STREAM
+            buf.extend_from_slice(&12u16.to_be_bytes()); // addr length
+            buf.extend_from_slice(&s.ip().octets());
+            buf.extend_from_slice(&d.ip().octets());
+            buf.extend_from_slice(&s.port().to_be_bytes());
+            buf.extend_from_slice(&d.port().to_be_bytes());
+        }
+        (SocketAddr::V6(s), SocketAddr::V6(d)) => {
+            buf.push(0x21); // version 2 | PROXY command
+            buf.push(0x21); // AF_INET6 | STREAM
+            buf.extend_from_slice(&36u16.to_be_bytes()); // addr length
+            buf.extend_from_slice(&s.ip().octets());
+            buf.extend_from_slice(&d.ip().octets());
+            buf.extend_from_slice(&s.port().to_be_bytes());
+            buf.extend_from_slice(&d.port().to_be_bytes());
+        }
+        _ => panic!("Mismatched address families"),
+    }
+    buf
+}
+
+/// Build a PROXY protocol v2 LOCAL header (health check probe).
+pub fn build_pp_v2_local() -> Vec<u8> {
+    let mut buf = Vec::new();
+    buf.extend_from_slice(&PP_V2_SIGNATURE);
+    buf.push(0x20); // version 2 | LOCAL command
+    buf.push(0x00); // AF_UNSPEC
+    buf.extend_from_slice(&0u16.to_be_bytes()); // no address data
+    buf
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tokio::io::AsyncWriteExt;
+    use tokio::net::TcpListener;
+
+    /// Helper: create a TCP pair and write data to the client side, then parse from server side.
+    async fn parse_header_from_bytes(header_bytes: &[u8]) -> Result<ProxyHeader> {
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let addr = listener.local_addr().unwrap();
+
+        let data = header_bytes.to_vec();
+        let client_task = tokio::spawn(async move {
+            let mut client = TcpStream::connect(addr).await.unwrap();
+            client.write_all(&data).await.unwrap();
+            client // keep alive
+        });
+
+        let (mut server_stream, _) = listener.accept().await.unwrap();
+        let result = read_proxy_header(&mut server_stream).await;
+        let _client = client_task.await.unwrap();
+        result
+    }
+
+    #[tokio::test]
+    async fn parse_valid_ipv4_header() {
+        let src = "203.0.113.50:12345".parse::<SocketAddr>().unwrap();
+        let dst = "10.0.0.1:443".parse::<SocketAddr>().unwrap();
+        let header = build_pp_v2_header(src, dst);
+
+        let parsed = parse_header_from_bytes(&header).await.unwrap();
+        assert!(!parsed.is_local);
+        assert_eq!(parsed.src_addr, src);
+        assert_eq!(parsed.dst_addr, dst);
+    }
+
+    #[tokio::test]
+    async fn parse_valid_ipv6_header() {
+        let src = "[2001:db8::1]:54321".parse::<SocketAddr>().unwrap();
+        let dst = "[2001:db8::2]:443".parse::<SocketAddr>().unwrap();
+        let header = build_pp_v2_header(src, dst);
+
+        let parsed = parse_header_from_bytes(&header).await.unwrap();
+        assert!(!parsed.is_local);
+        assert_eq!(parsed.src_addr, src);
+        assert_eq!(parsed.dst_addr, dst);
+    }
+
+    #[tokio::test]
+    async fn parse_local_command() {
+        let header = build_pp_v2_local();
+        let parsed = parse_header_from_bytes(&header).await.unwrap();
+        assert!(parsed.is_local);
+    }
+
+    #[tokio::test]
+    async fn reject_invalid_signature() {
+        let mut header = build_pp_v2_local();
+        header[0] = 0xFF; // corrupt signature
+        let result = parse_header_from_bytes(&header).await;
+        assert!(result.is_err());
+        assert!(result.unwrap_err().to_string().contains("signature"));
+    }
+
+    #[tokio::test]
+    async fn reject_wrong_version() {
+        let mut header = build_pp_v2_local();
+        header[12] = 0x10; // version 1 instead of 2
+        let result = parse_header_from_bytes(&header).await;
+        assert!(result.is_err());
+        assert!(result.unwrap_err().to_string().contains("version"));
+    }
+
+    #[tokio::test]
+    async fn reject_truncated_header() {
+        // Only 10 bytes — not even the full signature
+        let result = parse_header_from_bytes(&[0x0D, 0x0A, 0x0D, 0x0A, 0x00, 0x0D, 0x0A, 0x51, 0x55, 0x49]).await;
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn ipv4_header_is_exactly_28_bytes() {
+        let src = "1.2.3.4:80".parse::<SocketAddr>().unwrap();
+        let dst = "5.6.7.8:443".parse::<SocketAddr>().unwrap();
+        let header = build_pp_v2_header(src, dst);
+        // 12 sig + 1 ver/cmd + 1 fam/proto + 2 len + 12 addrs = 28
+        assert_eq!(header.len(), 28);
+    }
+
+    #[tokio::test]
+    async fn ipv6_header_is_exactly_52_bytes() {
+        let src = "[::1]:80".parse::<SocketAddr>().unwrap();
+        let dst = "[::2]:443".parse::<SocketAddr>().unwrap();
+        let header = build_pp_v2_header(src, dst);
+        // 12 sig + 1 ver/cmd + 1 fam/proto + 2 len + 36 addrs = 52
+        assert_eq!(header.len(), 52);
+    }
+}

rust/src/qos.rs

@@ -0,0 +1,490 @@
+use std::collections::HashMap;
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+use tokio::sync::mpsc;
+
+/// Priority levels for IP packets.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[repr(u8)]
+pub enum Priority {
+    High = 0,
+    Normal = 1,
+    Low = 2,
+}
+
+/// QoS statistics per priority level.
+pub struct QosStats {
+    pub high_enqueued: AtomicU64,
+    pub normal_enqueued: AtomicU64,
+    pub low_enqueued: AtomicU64,
+    pub high_dropped: AtomicU64,
+    pub normal_dropped: AtomicU64,
+    pub low_dropped: AtomicU64,
+}
+
+impl QosStats {
+    pub fn new() -> Self {
+        Self {
+            high_enqueued: AtomicU64::new(0),
+            normal_enqueued: AtomicU64::new(0),
+            low_enqueued: AtomicU64::new(0),
+            high_dropped: AtomicU64::new(0),
+            normal_dropped: AtomicU64::new(0),
+            low_dropped: AtomicU64::new(0),
+        }
+    }
+}
+
+impl Default for QosStats {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// ============================================================================
+// Packet classification
+// ============================================================================
+
+/// 5-tuple flow key for tracking bulk flows.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+struct FlowKey {
+    src_ip: u32,
+    dst_ip: u32,
+    src_port: u16,
+    dst_port: u16,
+    protocol: u8,
+}
+
+/// Per-flow state for bulk detection.
+struct FlowState {
+    bytes_total: u64,
+    window_start: Instant,
+}
+
+/// Tracks per-flow byte counts for bulk flow detection.
+struct FlowTracker {
+    flows: HashMap<FlowKey, FlowState>,
+    window_duration: Duration,
+    max_flows: usize,
+}
+
+impl FlowTracker {
+    fn new(window_duration: Duration, max_flows: usize) -> Self {
+        Self {
+            flows: HashMap::new(),
+            window_duration,
+            max_flows,
+        }
+    }
+
+    /// Record bytes for a flow. Returns true if the flow exceeds the threshold.
+    fn record(&mut self, key: FlowKey, bytes: u64, threshold: u64) -> bool {
+        let now = Instant::now();
+
+        // Evict if at capacity — remove oldest entry
+        if self.flows.len() >= self.max_flows && !self.flows.contains_key(&key) {
+            if let Some(oldest_key) = self
+                .flows
+                .iter()
+                .min_by_key(|(_, v)| v.window_start)
+                .map(|(k, _)| *k)
+            {
+                self.flows.remove(&oldest_key);
+            }
+        }
+
+        let state = self.flows.entry(key).or_insert(FlowState {
+            bytes_total: 0,
+            window_start: now,
+        });
+
+        // Reset window if expired
+        if now.duration_since(state.window_start) > self.window_duration {
+            state.bytes_total = 0;
+            state.window_start = now;
+        }
+
+        state.bytes_total += bytes;
+        state.bytes_total > threshold
+    }
+}
+
+/// Classifies raw IP packets into priority levels.
+pub struct PacketClassifier {
+    flow_tracker: FlowTracker,
+    /// Byte threshold for classifying a flow as "bulk" (Low priority).
+    bulk_threshold_bytes: u64,
+}
+
+impl PacketClassifier {
+    /// Create a new classifier.
+    ///
+    /// - `bulk_threshold_bytes`: bytes per flow within window to trigger Low priority (default: 1MB)
+    pub fn new(bulk_threshold_bytes: u64) -> Self {
+        Self {
+            flow_tracker: FlowTracker::new(Duration::from_secs(60), 10_000),
+            bulk_threshold_bytes,
+        }
+    }
+
+    /// Classify a raw IPv4 packet into a priority level.
+    ///
+    /// The packet must start with the IPv4 header (as read from a TUN device).
+    pub fn classify(&mut self, ip_packet: &[u8]) -> Priority {
+        // Need at least 20 bytes for a minimal IPv4 header
+        if ip_packet.len() < 20 {
+            return Priority::Normal;
+        }
+
+        let version = ip_packet[0] >> 4;
+        if version != 4 {
+            return Priority::Normal; // Only classify IPv4 for now
+        }
+
+        let ihl = (ip_packet[0] & 0x0F) as usize;
+        let header_len = ihl * 4;
+        let protocol = ip_packet[9];
+        let total_len = u16::from_be_bytes([ip_packet[2], ip_packet[3]]) as usize;
+
+        // ICMP is always high priority
+        if protocol == 1 {
+            return Priority::High;
+        }
+
+        // Small packets (<128 bytes) are high priority (likely interactive)
+        if total_len < 128 {
+            return Priority::High;
+        }
+
+        // Extract ports for TCP (6) and UDP (17)
+        let (src_port, dst_port) = if (protocol == 6 || protocol == 17)
+            && ip_packet.len() >= header_len + 4
+        {
+            let sp = u16::from_be_bytes([ip_packet[header_len], ip_packet[header_len + 1]]);
+            let dp = u16::from_be_bytes([ip_packet[header_len + 2], ip_packet[header_len + 3]]);
+            (sp, dp)
+        } else {
+            (0, 0)
+        };
+
+        // DNS (port 53) and SSH (port 22) are high priority
+        if dst_port == 53 || src_port == 53 || dst_port == 22 || src_port == 22 {
+            return Priority::High;
+        }
+
+        // Check for bulk flow
+        if protocol == 6 || protocol == 17 {
+            let src_ip = u32::from_be_bytes([ip_packet[12], ip_packet[13], ip_packet[14], ip_packet[15]]);
+            let dst_ip = u32::from_be_bytes([ip_packet[16], ip_packet[17], ip_packet[18], ip_packet[19]]);
+
+            let key = FlowKey {
+                src_ip,
+                dst_ip,
+                src_port,
+                dst_port,
+                protocol,
+            };
+
+            if self.flow_tracker.record(key, total_len as u64, self.bulk_threshold_bytes) {
+                return Priority::Low;
+            }
+        }
+
+        Priority::Normal
+    }
+}
+
+// ============================================================================
+// Priority channel set
+// ============================================================================
+
+/// Error returned when a packet is dropped.
+#[derive(Debug)]
+pub enum PacketDropped {
+    LowPriorityDrop,
+    NormalPriorityDrop,
+    HighPriorityDrop,
+    ChannelClosed,
+}
+
+/// Sending half of the priority channel set.
+pub struct PrioritySender {
+    high_tx: mpsc::Sender<Vec<u8>>,
+    normal_tx: mpsc::Sender<Vec<u8>>,
+    low_tx: mpsc::Sender<Vec<u8>>,
+    stats: Arc<QosStats>,
+}
+
+impl PrioritySender {
+    /// Send a packet with the given priority. Implements smart dropping under backpressure.
+    pub async fn send(&self, packet: Vec<u8>, priority: Priority) -> Result<(), PacketDropped> {
+        let (tx, enqueued_counter) = match priority {
+            Priority::High => (&self.high_tx, &self.stats.high_enqueued),
+            Priority::Normal => (&self.normal_tx, &self.stats.normal_enqueued),
+            Priority::Low => (&self.low_tx, &self.stats.low_enqueued),
+        };
+
+        match tx.try_send(packet) {
+            Ok(()) => {
+                enqueued_counter.fetch_add(1, Ordering::Relaxed);
+                Ok(())
+            }
+            Err(mpsc::error::TrySendError::Full(packet)) => {
+                self.handle_backpressure(packet, priority).await
+            }
+            Err(mpsc::error::TrySendError::Closed(_)) => Err(PacketDropped::ChannelClosed),
+        }
+    }
+
+    async fn handle_backpressure(
+        &self,
+        packet: Vec<u8>,
+        priority: Priority,
+    ) -> Result<(), PacketDropped> {
+        match priority {
+            Priority::Low => {
+                self.stats.low_dropped.fetch_add(1, Ordering::Relaxed);
+                Err(PacketDropped::LowPriorityDrop)
+            }
+            Priority::Normal => {
+                self.stats.normal_dropped.fetch_add(1, Ordering::Relaxed);
+                Err(PacketDropped::NormalPriorityDrop)
+            }
+            Priority::High => {
+                // Last resort: briefly wait for space, then drop
+                match tokio::time::timeout(
+                    Duration::from_millis(5),
+                    self.high_tx.send(packet),
+                )
+                .await
+                {
+                    Ok(Ok(())) => {
+                        self.stats.high_enqueued.fetch_add(1, Ordering::Relaxed);
+                        Ok(())
+                    }
+                    _ => {
+                        self.stats.high_dropped.fetch_add(1, Ordering::Relaxed);
+                        Err(PacketDropped::HighPriorityDrop)
+                    }
+                }
+            }
+        }
+    }
+}
+
+/// Receiving half of the priority channel set.
+pub struct PriorityReceiver {
+    high_rx: mpsc::Receiver<Vec<u8>>,
+    normal_rx: mpsc::Receiver<Vec<u8>>,
+    low_rx: mpsc::Receiver<Vec<u8>>,
+}
+
+impl PriorityReceiver {
+    /// Receive the next packet, draining high-priority first (biased select).
+    pub async fn recv(&mut self) -> Option<Vec<u8>> {
+        tokio::select! {
+            biased;
+            Some(pkt) = self.high_rx.recv() => Some(pkt),
+            Some(pkt) = self.normal_rx.recv() => Some(pkt),
+            Some(pkt) = self.low_rx.recv() => Some(pkt),
+            else => None,
+        }
+    }
+}
+
+/// Create a priority channel set split into sender and receiver halves.
+///
+/// - `high_cap`: capacity of the high-priority channel
+/// - `normal_cap`: capacity of the normal-priority channel
+/// - `low_cap`: capacity of the low-priority channel
+pub fn create_priority_channels(
+    high_cap: usize,
+    normal_cap: usize,
+    low_cap: usize,
+) -> (PrioritySender, PriorityReceiver) {
+    let (high_tx, high_rx) = mpsc::channel(high_cap);
+    let (normal_tx, normal_rx) = mpsc::channel(normal_cap);
+    let (low_tx, low_rx) = mpsc::channel(low_cap);
+    let stats = Arc::new(QosStats::new());
+
+    let sender = PrioritySender {
+        high_tx,
+        normal_tx,
+        low_tx,
+        stats,
+    };
+
+    let receiver = PriorityReceiver {
+        high_rx,
+        normal_rx,
+        low_rx,
+    };
+
+    (sender, receiver)
+}
+
+/// Get a reference to the QoS stats from a sender.
+impl PrioritySender {
+    pub fn stats(&self) -> &Arc<QosStats> {
+        &self.stats
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // Helper: craft a minimal IPv4 packet
+    fn make_ipv4_packet(protocol: u8, src_port: u16, dst_port: u16, total_len: u16) -> Vec<u8> {
+        let mut pkt = vec![0u8; total_len.max(24) as usize];
+        pkt[0] = 0x45; // version 4, IHL 5
+        pkt[2..4].copy_from_slice(&total_len.to_be_bytes());
+        pkt[9] = protocol;
+        // src IP
+        pkt[12..16].copy_from_slice(&[10, 0, 0, 1]);
+        // dst IP
+        pkt[16..20].copy_from_slice(&[10, 0, 0, 2]);
+        // ports (at offset 20 for IHL=5)
+        pkt[20..22].copy_from_slice(&src_port.to_be_bytes());
+        pkt[22..24].copy_from_slice(&dst_port.to_be_bytes());
+        pkt
+    }
+
+    #[test]
+    fn classify_icmp_as_high() {
+        let mut c = PacketClassifier::new(1_000_000);
+        let pkt = make_ipv4_packet(1, 0, 0, 64); // ICMP
+        assert_eq!(c.classify(&pkt), Priority::High);
+    }
+
+    #[test]
+    fn classify_dns_as_high() {
+        let mut c = PacketClassifier::new(1_000_000);
+        let pkt = make_ipv4_packet(17, 12345, 53, 200); // UDP to port 53
+        assert_eq!(c.classify(&pkt), Priority::High);
+    }
+
+    #[test]
+    fn classify_ssh_as_high() {
+        let mut c = PacketClassifier::new(1_000_000);
+        let pkt = make_ipv4_packet(6, 54321, 22, 200); // TCP to port 22
+        assert_eq!(c.classify(&pkt), Priority::High);
+    }
+
+    #[test]
+    fn classify_small_packet_as_high() {
+        let mut c = PacketClassifier::new(1_000_000);
+        let pkt = make_ipv4_packet(6, 12345, 8080, 64); // Small TCP packet
+        assert_eq!(c.classify(&pkt), Priority::High);
+    }
+
+    #[test]
+    fn classify_normal_http() {
+        let mut c = PacketClassifier::new(1_000_000);
+        let pkt = make_ipv4_packet(6, 12345, 80, 500); // TCP to port 80, >128B
+        assert_eq!(c.classify(&pkt), Priority::Normal);
+    }
+
+    #[test]
+    fn classify_bulk_flow_as_low() {
+        let mut c = PacketClassifier::new(10_000); // Low threshold for testing
+
+        // Send enough traffic to exceed the threshold
+        for _ in 0..100 {
+            let pkt = make_ipv4_packet(6, 12345, 80, 500);
+            c.classify(&pkt);
+        }
+
+        // Next packet from same flow should be Low
+        let pkt = make_ipv4_packet(6, 12345, 80, 500);
+        assert_eq!(c.classify(&pkt), Priority::Low);
+    }
+
+    #[test]
+    fn classify_too_short_packet() {
+        let mut c = PacketClassifier::new(1_000_000);
+        let pkt = vec![0u8; 10]; // Too short for IPv4 header
+        assert_eq!(c.classify(&pkt), Priority::Normal);
+    }
+
+    #[test]
+    fn classify_non_ipv4() {
+        let mut c = PacketClassifier::new(1_000_000);
+        let mut pkt = vec![0u8; 40];
+        pkt[0] = 0x60; // IPv6 version nibble
+        assert_eq!(c.classify(&pkt), Priority::Normal);
+    }
+
+    #[tokio::test]
+    async fn priority_receiver_drains_high_first() {
+        let (sender, mut receiver) = create_priority_channels(8, 8, 8);
+
+        // Enqueue in reverse order
+        sender.send(vec![3], Priority::Low).await.unwrap();
+        sender.send(vec![2], Priority::Normal).await.unwrap();
+        sender.send(vec![1], Priority::High).await.unwrap();
+
+        // Should drain High first
+        assert_eq!(receiver.recv().await.unwrap(), vec![1]);
+        assert_eq!(receiver.recv().await.unwrap(), vec![2]);
+        assert_eq!(receiver.recv().await.unwrap(), vec![3]);
+    }
+
+    #[tokio::test]
+    async fn smart_dropping_low_priority() {
+        let (sender, _receiver) = create_priority_channels(8, 8, 1);
+
+        // Fill the low channel
+        sender.send(vec![0], Priority::Low).await.unwrap();
+
+        // Next low-priority send should be dropped
+        let result = sender.send(vec![1], Priority::Low).await;
+        assert!(matches!(result, Err(PacketDropped::LowPriorityDrop)));
+
+        assert_eq!(sender.stats().low_dropped.load(Ordering::Relaxed), 1);
+    }
+
+    #[tokio::test]
+    async fn smart_dropping_normal_priority() {
+        let (sender, _receiver) = create_priority_channels(8, 1, 8);
+
+        sender.send(vec![0], Priority::Normal).await.unwrap();
+
+        let result = sender.send(vec![1], Priority::Normal).await;
+        assert!(matches!(result, Err(PacketDropped::NormalPriorityDrop)));
+
+        assert_eq!(sender.stats().normal_dropped.load(Ordering::Relaxed), 1);
+    }
+
+    #[tokio::test]
+    async fn stats_track_enqueued() {
+        let (sender, _receiver) = create_priority_channels(8, 8, 8);
+
+        sender.send(vec![1], Priority::High).await.unwrap();
+        sender.send(vec![2], Priority::High).await.unwrap();
+        sender.send(vec![3], Priority::Normal).await.unwrap();
+        sender.send(vec![4], Priority::Low).await.unwrap();
+
+        assert_eq!(sender.stats().high_enqueued.load(Ordering::Relaxed), 2);
+        assert_eq!(sender.stats().normal_enqueued.load(Ordering::Relaxed), 1);
+        assert_eq!(sender.stats().low_enqueued.load(Ordering::Relaxed), 1);
+    }
+
+    #[test]
+    fn flow_tracker_evicts_at_capacity() {
+        let mut ft = FlowTracker::new(Duration::from_secs(60), 2);
+
+        let k1 = FlowKey { src_ip: 1, dst_ip: 2, src_port: 100, dst_port: 200, protocol: 6 };
+        let k2 = FlowKey { src_ip: 3, dst_ip: 4, src_port: 300, dst_port: 400, protocol: 6 };
+        let k3 = FlowKey { src_ip: 5, dst_ip: 6, src_port: 500, dst_port: 600, protocol: 6 };
+
+        ft.record(k1, 100, 1000);
+        ft.record(k2, 100, 1000);
+        // Should evict k1 (oldest)
+        ft.record(k3, 100, 1000);
+
+        assert_eq!(ft.flows.len(), 2);
+        assert!(!ft.flows.contains_key(&k1));
+    }
+}

rust/src/quic_transport.rs

@@ -0,0 +1,546 @@
+use anyhow::Result;
+use async_trait::async_trait;
+use quinn::crypto::rustls::QuicClientConfig;
+use rustls_pki_types::{CertificateDer, PrivateKeyDer, PrivatePkcs8KeyDer};
+use std::net::SocketAddr;
+use std::sync::Arc;
+use std::time::Duration;
+use tracing::{info, warn, debug};
+
+use crate::transport_trait::{TransportSink, TransportStream};
+
+// ============================================================================
+// TLS / Certificate helpers
+// ============================================================================
+
+/// Generate a self-signed certificate and private key for QUIC.
+pub fn generate_self_signed_cert() -> Result<(Vec<CertificateDer<'static>>, PrivateKeyDer<'static>)> {
+    let cert = rcgen::generate_simple_self_signed(vec!["smartvpn".to_string()])?;
+    let cert_der = CertificateDer::from(cert.cert);
+    let key_der = PrivateKeyDer::Pkcs8(PrivatePkcs8KeyDer::from(cert.key_pair.serialize_der()));
+    Ok((vec![cert_der], key_der))
+}
+
+/// Compute the SHA-256 hash of a DER-encoded certificate and return it as base64.
+pub fn cert_hash(cert_der: &CertificateDer<'_>) -> String {
+    use ring::digest;
+    let hash = digest::digest(&digest::SHA256, cert_der.as_ref());
+    base64::Engine::encode(&base64::engine::general_purpose::STANDARD, hash.as_ref())
+}
+
+// ============================================================================
+// Server-side QUIC endpoint
+// ============================================================================
+
+/// Configuration for the QUIC server endpoint.
+pub struct QuicServerConfig {
+    pub listen_addr: String,
+    pub cert_chain: Vec<CertificateDer<'static>>,
+    pub private_key: PrivateKeyDer<'static>,
+    pub idle_timeout_secs: u64,
+}
+
+/// Create a QUIC server endpoint bound to the given address.
+pub fn create_quic_server(config: QuicServerConfig) -> Result<quinn::Endpoint> {
+    let addr: SocketAddr = config.listen_addr.parse()?;
+
+    let provider = Arc::new(rustls::crypto::ring::default_provider());
+    let mut tls_config = rustls::ServerConfig::builder_with_provider(provider)
+        .with_safe_default_protocol_versions()?
+        .with_no_client_auth()
+        .with_single_cert(config.cert_chain, config.private_key)?;
+    tls_config.alpn_protocols = vec![b"smartvpn".to_vec()];
+
+    let mut server_config = quinn::ServerConfig::with_crypto(Arc::new(
+        quinn::crypto::rustls::QuicServerConfig::try_from(tls_config)?,
+    ));
+
+    let mut transport = quinn::TransportConfig::default();
+    transport.max_idle_timeout(Some(
+        quinn::IdleTimeout::try_from(Duration::from_secs(config.idle_timeout_secs))?,
+    ));
+    // Enable datagrams with a generous max size
+    transport.datagram_receive_buffer_size(Some(65535));
+    transport.datagram_send_buffer_size(65535);
+    server_config.transport_config(Arc::new(transport));
+
+    let endpoint = quinn::Endpoint::server(server_config, addr)?;
+    info!("QUIC server listening on {}", addr);
+    Ok(endpoint)
+}
+
+// ============================================================================
+// Client-side QUIC connection
+// ============================================================================
+
+/// A certificate verifier that accepts any server certificate.
+/// Safe when Noise NK provides server authentication at the application layer.
+#[derive(Debug)]
+struct AcceptAnyCert;
+
+impl rustls::client::danger::ServerCertVerifier for AcceptAnyCert {
+    fn verify_server_cert(
+        &self,
+        _end_entity: &CertificateDer<'_>,
+        _intermediates: &[CertificateDer<'_>],
+        _server_name: &rustls::pki_types::ServerName<'_>,
+        _ocsp_response: &[u8],
+        _now: rustls::pki_types::UnixTime,
+    ) -> Result<rustls::client::danger::ServerCertVerified, rustls::Error> {
+        Ok(rustls::client::danger::ServerCertVerified::assertion())
+    }
+
+    fn verify_tls12_signature(
+        &self,
+        _message: &[u8],
+        _cert: &CertificateDer<'_>,
+        _dss: &rustls::DigitallySignedStruct,
+    ) -> Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error> {
+        Err(rustls::Error::General("TLS 1.2 not supported".to_string()))
+    }
+
+    fn verify_tls13_signature(
+        &self,
+        message: &[u8],
+        cert: &CertificateDer<'_>,
+        dss: &rustls::DigitallySignedStruct,
+    ) -> Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error> {
+        rustls::crypto::verify_tls13_signature(
+            message,
+            cert,
+            dss,
+            &rustls::crypto::ring::default_provider().signature_verification_algorithms,
+        )
+    }
+
+    fn supported_verify_schemes(&self) -> Vec<rustls::SignatureScheme> {
+        rustls::crypto::ring::default_provider()
+            .signature_verification_algorithms
+            .supported_schemes()
+    }
+}
+
+/// A certificate verifier that accepts any certificate matching a given SHA-256 hash.
+#[derive(Debug)]
+struct CertHashVerifier {
+    expected_hash: String,
+}
+
+impl rustls::client::danger::ServerCertVerifier for CertHashVerifier {
+    fn verify_server_cert(
+        &self,
+        end_entity: &CertificateDer<'_>,
+        _intermediates: &[CertificateDer<'_>],
+        _server_name: &rustls::pki_types::ServerName<'_>,
+        _ocsp_response: &[u8],
+        _now: rustls::pki_types::UnixTime,
+    ) -> Result<rustls::client::danger::ServerCertVerified, rustls::Error> {
+        let actual_hash = cert_hash(end_entity);
+        if actual_hash == self.expected_hash {
+            Ok(rustls::client::danger::ServerCertVerified::assertion())
+        } else {
+            Err(rustls::Error::General(format!(
+                "Certificate hash mismatch: expected {}, got {}",
+                self.expected_hash, actual_hash
+            )))
+        }
+    }
+
+    fn verify_tls12_signature(
+        &self,
+        _message: &[u8],
+        _cert: &CertificateDer<'_>,
+        _dss: &rustls::DigitallySignedStruct,
+    ) -> Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error> {
+        // QUIC always uses TLS 1.3
+        Err(rustls::Error::General("TLS 1.2 not supported".to_string()))
+    }
+
+    fn verify_tls13_signature(
+        &self,
+        message: &[u8],
+        cert: &CertificateDer<'_>,
+        dss: &rustls::DigitallySignedStruct,
+    ) -> Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error> {
+        rustls::crypto::verify_tls13_signature(
+            message,
+            cert,
+            dss,
+            &rustls::crypto::ring::default_provider().signature_verification_algorithms,
+        )
+    }
+
+    fn supported_verify_schemes(&self) -> Vec<rustls::SignatureScheme> {
+        rustls::crypto::ring::default_provider()
+            .signature_verification_algorithms
+            .supported_schemes()
+    }
+}
+
+/// Connect to a QUIC server.
+///
+/// - If `server_cert_hash` is provided, verifies the server certificate matches
+///   the given SHA-256 hash (cert pinning).
+/// - If `server_cert_hash` is `None`, accepts any server certificate. This is
+///   safe because the Noise NK handshake (which runs over the QUIC stream)
+///   authenticates the server via its pre-shared public key — the same trust
+///   model as WireGuard.
+pub async fn connect_quic(
+    addr: &str,
+    server_cert_hash: Option<&str>,
+) -> Result<quinn::Connection> {
+    let remote: SocketAddr = addr.parse()?;
+
+    let provider = Arc::new(rustls::crypto::ring::default_provider());
+    let tls_config = if let Some(hash) = server_cert_hash {
+        // Pin to a specific certificate hash
+        let mut config = rustls::ClientConfig::builder_with_provider(provider)
+            .with_safe_default_protocol_versions()?
+            .dangerous()
+            .with_custom_certificate_verifier(Arc::new(CertHashVerifier {
+                expected_hash: hash.to_string(),
+            }))
+            .with_no_client_auth();
+        config.alpn_protocols = vec![b"smartvpn".to_vec()];
+        config
+    } else {
+        // Accept any cert — Noise NK provides server authentication
+        let mut config = rustls::ClientConfig::builder_with_provider(provider)
+            .with_safe_default_protocol_versions()?
+            .dangerous()
+            .with_custom_certificate_verifier(Arc::new(AcceptAnyCert))
+            .with_no_client_auth();
+        config.alpn_protocols = vec![b"smartvpn".to_vec()];
+        config
+    };
+
+    let client_config = quinn::ClientConfig::new(Arc::new(
+        QuicClientConfig::try_from(tls_config)?,
+    ));
+
+    let mut endpoint = quinn::Endpoint::client("0.0.0.0:0".parse()?)?;
+    endpoint.set_default_client_config(client_config);
+
+    info!("Connecting to QUIC server at {}", addr);
+    let connection = endpoint.connect(remote, "smartvpn")?.await?;
+    info!("QUIC connection established");
+
+    Ok(connection)
+}
+
+// ============================================================================
+// QUIC Transport Sink / Stream implementations
+// ============================================================================
+
+/// QUIC transport sink — wraps a SendStream (reliable) and Connection (datagrams).
+pub struct QuicTransportSink {
+    send_stream: quinn::SendStream,
+    connection: quinn::Connection,
+}
+
+impl QuicTransportSink {
+    pub fn new(send_stream: quinn::SendStream, connection: quinn::Connection) -> Self {
+        Self {
+            send_stream,
+            connection,
+        }
+    }
+}
+
+#[async_trait]
+impl TransportSink for QuicTransportSink {
+    async fn send_reliable(&mut self, data: Vec<u8>) -> Result<()> {
+        // Length-prefix framing: [4-byte big-endian length][payload]
+        let len = data.len() as u32;
+        self.send_stream.write_all(&len.to_be_bytes()).await?;
+        self.send_stream.write_all(&data).await?;
+        Ok(())
+    }
+
+    async fn send_datagram(&mut self, data: Vec<u8>) -> Result<()> {
+        let max_size = self.connection.max_datagram_size();
+        match max_size {
+            Some(max) if data.len() <= max => {
+                self.connection.send_datagram(data.into())?;
+                Ok(())
+            }
+            _ => {
+                // Datagram too large or datagrams disabled — fall back to reliable
+                debug!("Datagram too large ({}B), falling back to reliable stream", data.len());
+                self.send_reliable(data).await
+            }
+        }
+    }
+
+    async fn close(&mut self) -> Result<()> {
+        self.send_stream.finish()?;
+        Ok(())
+    }
+}
+
+/// QUIC transport stream — wraps a RecvStream (reliable) and Connection (datagrams).
+pub struct QuicTransportStream {
+    recv_stream: quinn::RecvStream,
+    connection: quinn::Connection,
+}
+
+impl QuicTransportStream {
+    pub fn new(recv_stream: quinn::RecvStream, connection: quinn::Connection) -> Self {
+        Self {
+            recv_stream,
+            connection,
+        }
+    }
+}
+
+#[async_trait]
+impl TransportStream for QuicTransportStream {
+    async fn recv_reliable(&mut self) -> Result<Option<Vec<u8>>> {
+        // Read length prefix
+        let mut len_buf = [0u8; 4];
+        match self.recv_stream.read_exact(&mut len_buf).await {
+            Ok(()) => {}
+            Err(quinn::ReadExactError::FinishedEarly(_)) => return Ok(None),
+            Err(quinn::ReadExactError::ReadError(quinn::ReadError::ConnectionLost(e))) => {
+                warn!("QUIC connection lost: {}", e);
+                return Ok(None);
+            }
+            Err(e) => return Err(anyhow::anyhow!("QUIC read error: {}", e)),
+        }
+
+        let len = u32::from_be_bytes(len_buf) as usize;
+        if len > 65536 {
+            return Err(anyhow::anyhow!("Frame too large: {} bytes", len));
+        }
+
+        let mut data = vec![0u8; len];
+        match self.recv_stream.read_exact(&mut data).await {
+            Ok(()) => Ok(Some(data)),
+            Err(quinn::ReadExactError::FinishedEarly(_)) => Ok(None),
+            Err(e) => Err(anyhow::anyhow!("QUIC read error: {}", e)),
+        }
+    }
+
+    async fn recv_datagram(&mut self) -> Result<Option<Vec<u8>>> {
+        match self.connection.read_datagram().await {
+            Ok(data) => Ok(Some(data.to_vec())),
+            Err(quinn::ConnectionError::ApplicationClosed(_)) => Ok(None),
+            Err(quinn::ConnectionError::LocallyClosed) => Ok(None),
+            Err(e) => Err(anyhow::anyhow!("QUIC datagram error: {}", e)),
+        }
+    }
+
+    fn supports_datagrams(&self) -> bool {
+        self.connection.max_datagram_size().is_some()
+    }
+}
+
+/// Accept a QUIC connection and open a bidirectional control stream.
+/// Returns the transport sink/stream pair ready for the VPN handshake.
+pub async fn accept_quic_connection(
+    conn: quinn::Connection,
+) -> Result<(QuicTransportSink, QuicTransportStream)> {
+    // The client opens the bidirectional control stream
+    let (send, recv) = conn.accept_bi().await?;
+    info!("QUIC bidirectional control stream accepted");
+    Ok((
+        QuicTransportSink::new(send, conn.clone()),
+        QuicTransportStream::new(recv, conn),
+    ))
+}
+
+/// Open a QUIC connection's bidirectional control stream (client side).
+pub async fn open_quic_streams(
+    conn: quinn::Connection,
+) -> Result<(QuicTransportSink, QuicTransportStream)> {
+    let (send, recv) = conn.open_bi().await?;
+    info!("QUIC bidirectional control stream opened");
+    Ok((
+        QuicTransportSink::new(send, conn.clone()),
+        QuicTransportStream::new(recv, conn),
+    ))
+}
+
+// ============================================================================
+// Tests
+// ============================================================================
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_cert_generation_and_hash() {
+        let (certs, _key) = generate_self_signed_cert().unwrap();
+        assert_eq!(certs.len(), 1);
+        let hash = cert_hash(&certs[0]);
+        // SHA-256 base64 is 44 characters
+        assert_eq!(hash.len(), 44);
+    }
+
+    #[test]
+    fn test_cert_hash_deterministic() {
+        let (certs, _key) = generate_self_signed_cert().unwrap();
+        let hash1 = cert_hash(&certs[0]);
+        let hash2 = cert_hash(&certs[0]);
+        assert_eq!(hash1, hash2);
+    }
+
+    /// Helper: create QUIC server and client endpoints.
+    fn create_quic_endpoints() -> (quinn::Endpoint, quinn::Endpoint, String) {
+        let (certs, key) = generate_self_signed_cert().unwrap();
+        let hash = cert_hash(&certs[0]);
+        let provider = Arc::new(rustls::crypto::ring::default_provider());
+
+        let mut server_tls = rustls::ServerConfig::builder_with_provider(provider.clone())
+            .with_safe_default_protocol_versions().unwrap()
+            .with_no_client_auth()
+            .with_single_cert(certs, key).unwrap();
+        server_tls.alpn_protocols = vec![b"smartvpn".to_vec()];
+        let server_qcfg = quinn::ServerConfig::with_crypto(Arc::new(
+            quinn::crypto::rustls::QuicServerConfig::try_from(server_tls).unwrap(),
+        ));
+        let server_ep = quinn::Endpoint::server(server_qcfg, "127.0.0.1:0".parse().unwrap()).unwrap();
+
+        let mut client_tls = rustls::ClientConfig::builder_with_provider(provider)
+            .with_safe_default_protocol_versions().unwrap()
+            .dangerous()
+            .with_custom_certificate_verifier(Arc::new(CertHashVerifier {
+                expected_hash: hash,
+            }))
+            .with_no_client_auth();
+        client_tls.alpn_protocols = vec![b"smartvpn".to_vec()];
+        let client_config = quinn::ClientConfig::new(Arc::new(
+            QuicClientConfig::try_from(client_tls).unwrap(),
+        ));
+        let mut client_ep = quinn::Endpoint::client("0.0.0.0:0".parse().unwrap()).unwrap();
+        client_ep.set_default_client_config(client_config);
+
+        let server_addr = server_ep.local_addr().unwrap().to_string();
+        (server_ep, client_ep, server_addr)
+    }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+    async fn test_quic_server_client_roundtrip() {
+        let (server_ep, client_ep, server_addr) = create_quic_endpoints();
+        let addr: std::net::SocketAddr = server_addr.parse().unwrap();
+
+        // Server: accept, accept_bi, read, echo, finish
+        let server_task = tokio::spawn(async move {
+            let conn = server_ep.accept().await.unwrap().await.unwrap();
+            let (mut s_send, mut s_recv) = conn.accept_bi().await.unwrap();
+            let data = s_recv.read_to_end(1024).await.unwrap();
+            s_send.write_all(&data).await.unwrap();
+            s_send.finish().unwrap();
+            tokio::time::sleep(Duration::from_secs(1)).await;
+            server_ep
+        });
+
+        // Client: connect, open_bi, write, finish, read
+        let conn = client_ep.connect(addr, "smartvpn").unwrap().await.unwrap();
+        let (mut c_send, mut c_recv) = conn.open_bi().await.unwrap();
+        c_send.write_all(b"hello quinn").await.unwrap();
+        c_send.finish().unwrap();
+        let data = c_recv.read_to_end(1024).await.unwrap();
+        assert_eq!(&data[..], b"hello quinn");
+
+        let _ = server_task.await;
+        drop(client_ep);
+    }
+
+    /// Test transport trait wrappers over QUIC.
+    /// Key: client must send data first (QUIC streams are opened implicitly by data).
+    /// The server accept_bi runs concurrently with the client's first send_reliable.
+    #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+    async fn test_quic_transport_trait_roundtrip() {
+        let (server_ep, client_ep, server_addr) = create_quic_endpoints();
+        let addr: std::net::SocketAddr = server_addr.parse().unwrap();
+
+        // Server task: accept connection, then accept_bi (blocks until client sends data)
+        let server_task = tokio::spawn(async move {
+            let conn = server_ep.accept().await.unwrap().await.unwrap();
+            let (s_sink, s_stream) = accept_quic_connection(conn).await.unwrap();
+            (s_sink, s_stream, server_ep)
+        });
+
+        // Client: connect, open_bi via wrapper
+        let conn = client_ep.connect(addr, "smartvpn").unwrap().await.unwrap();
+        let (mut c_sink, mut c_stream) = open_quic_streams(conn).await.unwrap();
+
+        // Client sends first — this triggers the QUIC stream to become visible to the server
+        c_sink.send_reliable(b"hello-from-client".to_vec()).await.unwrap();
+
+        // Now server's accept_bi unblocks
+        let (mut s_sink, mut s_stream, _sep) = server_task.await.unwrap();
+
+        // Server reads the message
+        let msg = s_stream.recv_reliable().await.unwrap().unwrap();
+        assert_eq!(msg, b"hello-from-client");
+
+        // Server -> Client
+        s_sink.send_reliable(b"hello-from-server".to_vec()).await.unwrap();
+        let msg = c_stream.recv_reliable().await.unwrap().unwrap();
+        assert_eq!(msg, b"hello-from-server");
+
+        drop(client_ep);
+    }
+
+    /// Test QUIC datagram support.
+    #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+    async fn test_quic_datagram_exchange() {
+        let (server_ep, client_ep, server_addr) = create_quic_endpoints();
+        let addr: std::net::SocketAddr = server_addr.parse().unwrap();
+
+        // Server: accept, accept_bi (opens control stream), then read datagram
+        let server_task = tokio::spawn(async move {
+            let conn = server_ep.accept().await.unwrap().await.unwrap();
+            // Accept bi stream (control channel)
+            let (_s_sink, _s_stream) = accept_quic_connection(conn.clone()).await.unwrap();
+            // Read datagram
+            let dgram = conn.read_datagram().await.unwrap();
+            assert_eq!(&dgram[..], b"dgram-payload");
+            server_ep
+        });
+
+        // Client: connect, open bi stream (triggers server accept_bi), then send datagram
+        let conn = client_ep.connect(addr, "smartvpn").unwrap().await.unwrap();
+        let (mut c_sink, _c_stream) = open_quic_streams(conn.clone()).await.unwrap();
+
+        // Send initial data to open the stream (required for QUIC)
+        c_sink.send_reliable(b"init".to_vec()).await.unwrap();
+
+        // Small yield to let the server process the bi stream
+        tokio::task::yield_now().await;
+
+        // Send datagram
+        assert!(conn.max_datagram_size().is_some());
+        conn.send_datagram(bytes::Bytes::from_static(b"dgram-payload")).unwrap();
+
+        let _ = server_task.await.unwrap();
+        drop(client_ep);
+    }
+
+    /// Test that supports_datagrams returns true for QUIC transports.
+    #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+    async fn test_quic_supports_datagrams() {
+        let (server_ep, client_ep, server_addr) = create_quic_endpoints();
+        let addr: std::net::SocketAddr = server_addr.parse().unwrap();
+
+        let server_task = tokio::spawn(async move {
+            let conn = server_ep.accept().await.unwrap().await.unwrap();
+            let (_s_sink, s_stream) = accept_quic_connection(conn).await.unwrap();
+            assert!(s_stream.supports_datagrams());
+            server_ep
+        });
+
+        let conn = client_ep.connect(addr, "smartvpn").unwrap().await.unwrap();
+        let (mut c_sink, c_stream) = open_quic_streams(conn).await.unwrap();
+        assert!(c_stream.supports_datagrams());
+
+        // Send data to trigger server's accept_bi
+        c_sink.send_reliable(b"ping".to_vec()).await.unwrap();
+
+        let _ = server_task.await.unwrap();
+        drop(client_ep);
+    }
+}

rust/src/ratelimit.rs

@@ -0,0 +1,141 @@
+use std::time::Instant;
+
+/// A token bucket rate limiter operating on byte granularity.
+pub struct TokenBucket {
+    /// Tokens (bytes) added per second.
+    rate: f64,
+    /// Maximum burst capacity in bytes.
+    burst: f64,
+    /// Currently available tokens.
+    tokens: f64,
+    /// Last time tokens were refilled.
+    last_refill: Instant,
+}
+
+impl TokenBucket {
+    /// Create a new token bucket.
+    ///
+    /// - `rate_bytes_per_sec`: sustained rate in bytes/second
+    /// - `burst_bytes`: maximum burst size in bytes (also the initial token count)
+    pub fn new(rate_bytes_per_sec: u64, burst_bytes: u64) -> Self {
+        let burst = burst_bytes as f64;
+        Self {
+            rate: rate_bytes_per_sec as f64,
+            burst,
+            tokens: burst, // start full
+            last_refill: Instant::now(),
+        }
+    }
+
+    /// Try to consume `bytes` tokens. Returns `true` if allowed, `false` if rate exceeded.
+    pub fn try_consume(&mut self, bytes: usize) -> bool {
+        self.refill();
+        let needed = bytes as f64;
+        if needed <= self.tokens {
+            self.tokens -= needed;
+            true
+        } else {
+            false
+        }
+    }
+
+    /// Update rate and burst limits dynamically (for live IPC reconfiguration).
+    pub fn update_limits(&mut self, rate_bytes_per_sec: u64, burst_bytes: u64) {
+        self.rate = rate_bytes_per_sec as f64;
+        self.burst = burst_bytes as f64;
+        // Cap current tokens at new burst
+        if self.tokens > self.burst {
+            self.tokens = self.burst;
+        }
+    }
+
+    fn refill(&mut self) {
+        let now = Instant::now();
+        let elapsed = now.duration_since(self.last_refill).as_secs_f64();
+        self.last_refill = now;
+        self.tokens = (self.tokens + elapsed * self.rate).min(self.burst);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::time::Duration;
+
+    #[test]
+    fn allows_traffic_under_burst() {
+        let mut tb = TokenBucket::new(1_000_000, 2_000_000);
+        // Should allow up to burst size immediately
+        assert!(tb.try_consume(1_500_000));
+        assert!(tb.try_consume(400_000));
+    }
+
+    #[test]
+    fn blocks_traffic_over_burst() {
+        let mut tb = TokenBucket::new(1_000_000, 1_000_000);
+        // Consume entire burst
+        assert!(tb.try_consume(1_000_000));
+        // Next consume should fail (no time to refill)
+        assert!(!tb.try_consume(1));
+    }
+
+    #[test]
+    fn zero_consume_always_succeeds() {
+        let mut tb = TokenBucket::new(0, 0);
+        assert!(tb.try_consume(0));
+    }
+
+    #[test]
+    fn refills_over_time() {
+        let mut tb = TokenBucket::new(1_000_000, 1_000_000); // 1MB/s, 1MB burst
+        // Drain completely
+        assert!(tb.try_consume(1_000_000));
+        assert!(!tb.try_consume(1));
+
+        // Wait 100ms — should refill ~100KB
+        std::thread::sleep(Duration::from_millis(100));
+        assert!(tb.try_consume(50_000)); // 50KB should be available after ~100ms at 1MB/s
+    }
+
+    #[test]
+    fn update_limits_caps_tokens() {
+        let mut tb = TokenBucket::new(1_000_000, 2_000_000);
+        // Tokens start at burst (2MB)
+        tb.update_limits(500_000, 500_000);
+        // Tokens should be capped to new burst (500KB)
+        assert!(tb.try_consume(500_000));
+        assert!(!tb.try_consume(1));
+    }
+
+    #[test]
+    fn update_limits_changes_rate() {
+        let mut tb = TokenBucket::new(1_000_000, 1_000_000);
+        assert!(tb.try_consume(1_000_000)); // drain
+
+        // Change to higher rate
+        tb.update_limits(10_000_000, 10_000_000);
+        std::thread::sleep(Duration::from_millis(50));
+        // At 10MB/s, 50ms should refill ~500KB
+        assert!(tb.try_consume(200_000));
+    }
+
+    #[test]
+    fn zero_rate_blocks_after_burst() {
+        let mut tb = TokenBucket::new(0, 100);
+        assert!(tb.try_consume(100));
+        std::thread::sleep(Duration::from_millis(10));
+        // Zero rate means no refill
+        assert!(!tb.try_consume(1));
+    }
+
+    #[test]
+    fn tokens_do_not_exceed_burst() {
+        // Use a low rate so refill between consecutive calls is negligible
+        let mut tb = TokenBucket::new(100, 1_000);
+        // Wait to accumulate — but should cap at burst
+        std::thread::sleep(Duration::from_millis(50));
+        assert!(tb.try_consume(1_000));
+        // At 100 bytes/sec, the few μs between calls add ~0 tokens
+        assert!(!tb.try_consume(1));
+    }
+}

rust/src/telemetry.rs

@@ -0,0 +1,317 @@
+use serde::Serialize;
+use std::collections::VecDeque;
+use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
+
+/// A single RTT sample.
+#[derive(Debug, Clone)]
+struct RttSample {
+    _rtt: Duration,
+    _timestamp: Instant,
+    was_timeout: bool,
+}
+
+/// Snapshot of connection quality metrics.
+#[derive(Debug, Clone, Serialize, Default)]
+#[serde(rename_all = "camelCase")]
+pub struct ConnectionQuality {
+    /// Smoothed RTT in milliseconds (EMA, RFC 6298 style).
+    pub srtt_ms: f64,
+    /// Jitter in milliseconds (mean deviation of RTT).
+    pub jitter_ms: f64,
+    /// Minimum RTT observed in the sample window.
+    pub min_rtt_ms: f64,
+    /// Maximum RTT observed in the sample window.
+    pub max_rtt_ms: f64,
+    /// Packet loss ratio over the sample window (0.0 - 1.0).
+    pub loss_ratio: f64,
+    /// Number of consecutive keepalive timeouts (0 if last succeeded).
+    pub consecutive_timeouts: u32,
+    /// Total keepalives sent.
+    pub keepalives_sent: u64,
+    /// Total keepalive ACKs received.
+    pub keepalives_acked: u64,
+}
+
+/// Tracks connection quality from keepalive round-trips.
+pub struct RttTracker {
+    /// Maximum number of samples to keep in the window.
+    max_samples: usize,
+    /// Recent RTT samples (including timeout markers).
+    samples: VecDeque<RttSample>,
+    /// When the last keepalive was sent (for computing RTT on ACK).
+    pending_ping_sent_at: Option<Instant>,
+    /// Number of consecutive keepalive timeouts.
+    pub consecutive_timeouts: u32,
+    /// Smoothed RTT (EMA).
+    srtt: Option<f64>,
+    /// Jitter (mean deviation).
+    jitter: f64,
+    /// Minimum RTT observed.
+    min_rtt: f64,
+    /// Maximum RTT observed.
+    max_rtt: f64,
+    /// Total keepalives sent.
+    keepalives_sent: u64,
+    /// Total keepalive ACKs received.
+    keepalives_acked: u64,
+    /// Previous RTT sample for jitter calculation.
+    last_rtt_ms: Option<f64>,
+}
+
+impl RttTracker {
+    /// Create a new tracker with the given window size.
+    pub fn new(max_samples: usize) -> Self {
+        Self {
+            max_samples,
+            samples: VecDeque::with_capacity(max_samples),
+            pending_ping_sent_at: None,
+            consecutive_timeouts: 0,
+            srtt: None,
+            jitter: 0.0,
+            min_rtt: f64::MAX,
+            max_rtt: 0.0,
+            keepalives_sent: 0,
+            keepalives_acked: 0,
+            last_rtt_ms: None,
+        }
+    }
+
+    /// Record that a keepalive was sent.
+    /// Returns a millisecond timestamp (since UNIX epoch) to embed in the keepalive payload.
+    pub fn mark_ping_sent(&mut self) -> u64 {
+        self.pending_ping_sent_at = Some(Instant::now());
+        self.keepalives_sent += 1;
+        SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap_or_default()
+            .as_millis() as u64
+    }
+
+    /// Record that a keepalive ACK was received with the echoed timestamp.
+    /// Returns the computed RTT if a pending ping was recorded.
+    pub fn record_ack(&mut self, _echoed_timestamp_ms: u64) -> Option<Duration> {
+        let sent_at = self.pending_ping_sent_at.take()?;
+        let rtt = sent_at.elapsed();
+        let rtt_ms = rtt.as_secs_f64() * 1000.0;
+
+        self.keepalives_acked += 1;
+        self.consecutive_timeouts = 0;
+
+        // Update SRTT (RFC 6298: alpha = 1/8)
+        match self.srtt {
+            None => {
+                self.srtt = Some(rtt_ms);
+                self.jitter = rtt_ms / 2.0;
+            }
+            Some(prev_srtt) => {
+                // RTTVAR = (1 - beta) * RTTVAR + beta * |SRTT - R|   (beta = 1/4)
+                self.jitter = 0.75 * self.jitter + 0.25 * (prev_srtt - rtt_ms).abs();
+                // SRTT = (1 - alpha) * SRTT + alpha * R              (alpha = 1/8)
+                self.srtt = Some(0.875 * prev_srtt + 0.125 * rtt_ms);
+            }
+        }
+
+        // Update min/max
+        if rtt_ms < self.min_rtt {
+            self.min_rtt = rtt_ms;
+        }
+        if rtt_ms > self.max_rtt {
+            self.max_rtt = rtt_ms;
+        }
+
+        self.last_rtt_ms = Some(rtt_ms);
+
+        // Push sample into window
+        if self.samples.len() >= self.max_samples {
+            self.samples.pop_front();
+        }
+        self.samples.push_back(RttSample {
+            _rtt: rtt,
+            _timestamp: Instant::now(),
+            was_timeout: false,
+        });
+
+        Some(rtt)
+    }
+
+    /// Record that a keepalive timed out (no ACK received).
+    pub fn record_timeout(&mut self) {
+        self.consecutive_timeouts += 1;
+        self.pending_ping_sent_at = None;
+
+        if self.samples.len() >= self.max_samples {
+            self.samples.pop_front();
+        }
+        self.samples.push_back(RttSample {
+            _rtt: Duration::ZERO,
+            _timestamp: Instant::now(),
+            was_timeout: true,
+        });
+    }
+
+    /// Get a snapshot of the current connection quality.
+    pub fn snapshot(&self) -> ConnectionQuality {
+        let loss_ratio = if self.samples.is_empty() {
+            0.0
+        } else {
+            let timeouts = self.samples.iter().filter(|s| s.was_timeout).count();
+            timeouts as f64 / self.samples.len() as f64
+        };
+
+        ConnectionQuality {
+            srtt_ms: self.srtt.unwrap_or(0.0),
+            jitter_ms: self.jitter,
+            min_rtt_ms: if self.min_rtt == f64::MAX { 0.0 } else { self.min_rtt },
+            max_rtt_ms: self.max_rtt,
+            loss_ratio,
+            consecutive_timeouts: self.consecutive_timeouts,
+            keepalives_sent: self.keepalives_sent,
+            keepalives_acked: self.keepalives_acked,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn new_tracker_has_zero_quality() {
+        let tracker = RttTracker::new(30);
+        let q = tracker.snapshot();
+        assert_eq!(q.srtt_ms, 0.0);
+        assert_eq!(q.jitter_ms, 0.0);
+        assert_eq!(q.loss_ratio, 0.0);
+        assert_eq!(q.consecutive_timeouts, 0);
+        assert_eq!(q.keepalives_sent, 0);
+        assert_eq!(q.keepalives_acked, 0);
+    }
+
+    #[test]
+    fn mark_ping_returns_timestamp() {
+        let mut tracker = RttTracker::new(30);
+        let ts = tracker.mark_ping_sent();
+        // Should be a reasonable epoch-ms value (after 2020)
+        assert!(ts > 1_577_836_800_000);
+        assert_eq!(tracker.keepalives_sent, 1);
+    }
+
+    #[test]
+    fn record_ack_computes_rtt() {
+        let mut tracker = RttTracker::new(30);
+        let ts = tracker.mark_ping_sent();
+        std::thread::sleep(Duration::from_millis(5));
+        let rtt = tracker.record_ack(ts);
+        assert!(rtt.is_some());
+        let rtt = rtt.unwrap();
+        assert!(rtt.as_millis() >= 4); // at least ~5ms minus scheduling jitter
+        assert_eq!(tracker.keepalives_acked, 1);
+        assert_eq!(tracker.consecutive_timeouts, 0);
+    }
+
+    #[test]
+    fn record_ack_without_pending_returns_none() {
+        let mut tracker = RttTracker::new(30);
+        assert!(tracker.record_ack(12345).is_none());
+    }
+
+    #[test]
+    fn srtt_converges() {
+        let mut tracker = RttTracker::new(30);
+
+        // Simulate several ping/ack cycles with ~10ms RTT
+        for _ in 0..10 {
+            let ts = tracker.mark_ping_sent();
+            std::thread::sleep(Duration::from_millis(10));
+            tracker.record_ack(ts);
+        }
+
+        let q = tracker.snapshot();
+        // SRTT should be roughly 10ms (allowing for scheduling variance)
+        assert!(q.srtt_ms > 5.0, "SRTT too low: {}", q.srtt_ms);
+        assert!(q.srtt_ms < 50.0, "SRTT too high: {}", q.srtt_ms);
+    }
+
+    #[test]
+    fn timeout_increments_counter_and_loss() {
+        let mut tracker = RttTracker::new(30);
+
+        tracker.mark_ping_sent();
+        tracker.record_timeout();
+        assert_eq!(tracker.consecutive_timeouts, 1);
+
+        tracker.mark_ping_sent();
+        tracker.record_timeout();
+        assert_eq!(tracker.consecutive_timeouts, 2);
+
+        let q = tracker.snapshot();
+        assert_eq!(q.loss_ratio, 1.0); // 2 timeouts out of 2 samples
+    }
+
+    #[test]
+    fn ack_resets_consecutive_timeouts() {
+        let mut tracker = RttTracker::new(30);
+
+        tracker.mark_ping_sent();
+        tracker.record_timeout();
+        assert_eq!(tracker.consecutive_timeouts, 1);
+
+        let ts = tracker.mark_ping_sent();
+        tracker.record_ack(ts);
+        assert_eq!(tracker.consecutive_timeouts, 0);
+    }
+
+    #[test]
+    fn loss_ratio_over_mixed_window() {
+        let mut tracker = RttTracker::new(30);
+
+        // 3 successful, 1 timeout, 1 successful = 1/5 = 0.2 loss
+        for _ in 0..3 {
+            let ts = tracker.mark_ping_sent();
+            tracker.record_ack(ts);
+        }
+        tracker.mark_ping_sent();
+        tracker.record_timeout();
+        let ts = tracker.mark_ping_sent();
+        tracker.record_ack(ts);
+
+        let q = tracker.snapshot();
+        assert!((q.loss_ratio - 0.2).abs() < 0.01);
+    }
+
+    #[test]
+    fn window_evicts_old_samples() {
+        let mut tracker = RttTracker::new(5);
+
+        // Fill window with 5 timeouts
+        for _ in 0..5 {
+            tracker.mark_ping_sent();
+            tracker.record_timeout();
+        }
+        assert_eq!(tracker.snapshot().loss_ratio, 1.0);
+
+        // Add 5 successes — should evict all timeouts
+        for _ in 0..5 {
+            let ts = tracker.mark_ping_sent();
+            tracker.record_ack(ts);
+        }
+        assert_eq!(tracker.snapshot().loss_ratio, 0.0);
+    }
+
+    #[test]
+    fn min_max_rtt_tracked() {
+        let mut tracker = RttTracker::new(30);
+
+        let ts = tracker.mark_ping_sent();
+        std::thread::sleep(Duration::from_millis(5));
+        tracker.record_ack(ts);
+
+        let ts = tracker.mark_ping_sent();
+        std::thread::sleep(Duration::from_millis(15));
+        tracker.record_ack(ts);
+
+        let q = tracker.snapshot();
+        assert!(q.min_rtt_ms < q.max_rtt_ms);
+        assert!(q.min_rtt_ms > 0.0);
+    }
+}

rust/src/transport_trait.rs

@@ -0,0 +1,116 @@
+use anyhow::Result;
+use async_trait::async_trait;
+use futures_util::{SinkExt, StreamExt};
+use tokio_tungstenite::tungstenite::Message;
+
+use crate::transport::WsStream;
+
+// ============================================================================
+// Transport trait abstraction
+// ============================================================================
+
+/// Outbound half of a VPN transport connection.
+#[async_trait]
+pub trait TransportSink: Send + 'static {
+    /// Send a framed binary message on the reliable channel.
+    async fn send_reliable(&mut self, data: Vec<u8>) -> Result<()>;
+
+    /// Send a datagram (unreliable, best-effort).
+    /// Falls back to reliable if the transport does not support datagrams.
+    async fn send_datagram(&mut self, data: Vec<u8>) -> Result<()>;
+
+    /// Gracefully close the transport.
+    async fn close(&mut self) -> Result<()>;
+}
+
+/// Inbound half of a VPN transport connection.
+#[async_trait]
+pub trait TransportStream: Send + 'static {
+    /// Receive the next reliable binary message. Returns `None` on close.
+    async fn recv_reliable(&mut self) -> Result<Option<Vec<u8>>>;
+
+    /// Receive the next datagram. Returns `None` if datagrams are unsupported
+    /// or the connection is closed.
+    async fn recv_datagram(&mut self) -> Result<Option<Vec<u8>>>;
+
+    /// Whether this transport supports unreliable datagrams.
+    fn supports_datagrams(&self) -> bool;
+}
+
+// ============================================================================
+// WebSocket implementation
+// ============================================================================
+
+/// WebSocket transport sink (wraps the write half of a split WsStream).
+pub struct WsTransportSink {
+    inner: futures_util::stream::SplitSink<WsStream, Message>,
+}
+
+impl WsTransportSink {
+    pub fn new(inner: futures_util::stream::SplitSink<WsStream, Message>) -> Self {
+        Self { inner }
+    }
+}
+
+#[async_trait]
+impl TransportSink for WsTransportSink {
+    async fn send_reliable(&mut self, data: Vec<u8>) -> Result<()> {
+        self.inner.send(Message::Binary(data.into())).await?;
+        Ok(())
+    }
+
+    async fn send_datagram(&mut self, data: Vec<u8>) -> Result<()> {
+        // WebSocket has no datagram support — fall back to reliable.
+        self.send_reliable(data).await
+    }
+
+    async fn close(&mut self) -> Result<()> {
+        self.inner.close().await?;
+        Ok(())
+    }
+}
+
+/// WebSocket transport stream (wraps the read half of a split WsStream).
+pub struct WsTransportStream {
+    inner: futures_util::stream::SplitStream<WsStream>,
+}
+
+impl WsTransportStream {
+    pub fn new(inner: futures_util::stream::SplitStream<WsStream>) -> Self {
+        Self { inner }
+    }
+}
+
+#[async_trait]
+impl TransportStream for WsTransportStream {
+    async fn recv_reliable(&mut self) -> Result<Option<Vec<u8>>> {
+        loop {
+            match self.inner.next().await {
+                Some(Ok(Message::Binary(data))) => return Ok(Some(data.to_vec())),
+                Some(Ok(Message::Close(_))) | None => return Ok(None),
+                Some(Ok(Message::Ping(_))) => {
+                    // Ping handling is done at the tungstenite layer automatically
+                    // when the sink side is alive. Just skip here.
+                    continue;
+                }
+                Some(Ok(_)) => continue,
+                Some(Err(e)) => return Err(anyhow::anyhow!("WebSocket error: {}", e)),
+            }
+        }
+    }
+
+    async fn recv_datagram(&mut self) -> Result<Option<Vec<u8>>> {
+        // WebSocket does not support datagrams.
+        Ok(None)
+    }
+
+    fn supports_datagrams(&self) -> bool {
+        false
+    }
+}
+
+/// Split a WebSocket stream into transport sink and stream halves.
+pub fn split_ws(ws: WsStream) -> (WsTransportSink, WsTransportStream) {
+    let (sink, stream) = ws.split();
+    (WsTransportSink::new(sink), WsTransportStream::new(stream))
+}

rust/src/tunnel.rs

@@ -1,5 +1,5 @@
 use anyhow::Result;
-use std::net::Ipv4Addr;
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 use tracing::info;
 
 /// Configuration for creating a TUN device.
@@ -64,6 +64,42 @@ pub async fn add_route(subnet: &str, device_name: &str) -> Result<()> {
     Ok(())
 }
 
+/// Action to take after checking a packet against the MTU.
+pub enum TunMtuAction {
+    /// Packet is within MTU limits, forward it.
+    Forward,
+    /// Packet is oversized; the Vec contains the ICMP too-big message to write back into TUN.
+    IcmpTooBig(Vec<u8>),
+}
+
+/// Check a TUN packet against the MTU and return the appropriate action.
+pub fn check_tun_mtu(packet: &[u8], mtu_config: &crate::mtu::MtuConfig) -> TunMtuAction {
+    match crate::mtu::check_mtu(packet, mtu_config) {
+        crate::mtu::MtuAction::Forward => TunMtuAction::Forward,
+        crate::mtu::MtuAction::SendIcmpTooBig(icmp) => TunMtuAction::IcmpTooBig(icmp),
+    }
+}
+
+/// Extract destination IP from a raw IP packet header.
+pub fn extract_dst_ip(packet: &[u8]) -> Option<IpAddr> {
+    if packet.is_empty() {
+        return None;
+    }
+    let version = packet[0] >> 4;
+    match version {
+        4 if packet.len() >= 20 => {
+            let dst = Ipv4Addr::new(packet[16], packet[17], packet[18], packet[19]);
+            Some(IpAddr::V4(dst))
+        }
+        6 if packet.len() >= 40 => {
+            let mut octets = [0u8; 16];
+            octets.copy_from_slice(&packet[24..40]);
+            Some(IpAddr::V6(Ipv6Addr::from(octets)))
+        }
+        _ => None,
+    }
+}
+
 /// Remove a route.
 pub async fn remove_route(subnet: &str, device_name: &str) -> Result<()> {
     let output = tokio::process::Command::new("ip")

rust/src/userspace_nat.rs

@@ -0,0 +1,640 @@
+use std::collections::{HashMap, VecDeque};
+use std::net::{Ipv4Addr, SocketAddr};
+use std::sync::Arc;
+use std::time::Duration;
+
+use anyhow::Result;
+use smoltcp::iface::{Config, Interface, SocketHandle, SocketSet};
+use smoltcp::phy::{self, Device, DeviceCapabilities, Medium};
+use smoltcp::socket::{tcp, udp};
+use smoltcp::wire::{HardwareAddress, IpAddress, IpCidr, IpEndpoint};
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::{TcpStream, UdpSocket};
+use tokio::sync::mpsc;
+use tracing::{debug, info, warn};
+
+use crate::server::ServerState;
+use crate::tunnel;
+
+// ============================================================================
+// Virtual IP device for smoltcp
+// ============================================================================
+
+pub struct VirtualIpDevice {
+    rx_queue: VecDeque<Vec<u8>>,
+    tx_queue: VecDeque<Vec<u8>>,
+    mtu: usize,
+}
+
+impl VirtualIpDevice {
+    pub fn new(mtu: usize) -> Self {
+        Self {
+            rx_queue: VecDeque::new(),
+            tx_queue: VecDeque::new(),
+            mtu,
+        }
+    }
+
+    pub fn inject_packet(&mut self, packet: Vec<u8>) {
+        self.rx_queue.push_back(packet);
+    }
+
+    pub fn drain_tx(&mut self) -> impl Iterator<Item = Vec<u8>> + '_ {
+        self.tx_queue.drain(..)
+    }
+}
+
+pub struct VirtualRxToken {
+    buffer: Vec<u8>,
+}
+
+impl phy::RxToken for VirtualRxToken {
+    fn consume<R, F>(self, f: F) -> R
+    where
+        F: FnOnce(&[u8]) -> R,
+    {
+        f(&self.buffer)
+    }
+}
+
+pub struct VirtualTxToken<'a> {
+    queue: &'a mut VecDeque<Vec<u8>>,
+}
+
+impl<'a> phy::TxToken for VirtualTxToken<'a> {
+    fn consume<R, F>(self, len: usize, f: F) -> R
+    where
+        F: FnOnce(&mut [u8]) -> R,
+    {
+        let mut buffer = vec![0u8; len];
+        let result = f(&mut buffer);
+        self.queue.push_back(buffer);
+        result
+    }
+}
+
+impl Device for VirtualIpDevice {
+    type RxToken<'a> = VirtualRxToken;
+    type TxToken<'a> = VirtualTxToken<'a>;
+
+    fn receive(
+        &mut self,
+        _timestamp: smoltcp::time::Instant,
+    ) -> Option<(Self::RxToken<'_>, Self::TxToken<'_>)> {
+        self.rx_queue.pop_front().map(|buffer| {
+            let rx = VirtualRxToken { buffer };
+            let tx = VirtualTxToken {
+                queue: &mut self.tx_queue,
+            };
+            (rx, tx)
+        })
+    }
+
+    fn transmit(&mut self, _timestamp: smoltcp::time::Instant) -> Option<Self::TxToken<'_>> {
+        Some(VirtualTxToken {
+            queue: &mut self.tx_queue,
+        })
+    }
+
+    fn capabilities(&self) -> DeviceCapabilities {
+        let mut caps = DeviceCapabilities::default();
+        caps.medium = Medium::Ip;
+        caps.max_transmission_unit = self.mtu;
+        caps.max_burst_size = Some(1);
+        caps
+    }
+}
+
+// ============================================================================
+// Session tracking
+// ============================================================================
+
+#[derive(Debug, Clone, Hash, Eq, PartialEq)]
+struct SessionKey {
+    src_ip: Ipv4Addr,
+    src_port: u16,
+    dst_ip: Ipv4Addr,
+    dst_port: u16,
+    protocol: u8,
+}
+
+struct TcpSession {
+    smoltcp_handle: SocketHandle,
+    bridge_data_tx: mpsc::Sender<Vec<u8>>,
+    #[allow(dead_code)]
+    client_ip: Ipv4Addr,
+}
+
+struct UdpSession {
+    smoltcp_handle: SocketHandle,
+    bridge_data_tx: mpsc::Sender<Vec<u8>>,
+    #[allow(dead_code)]
+    client_ip: Ipv4Addr,
+    last_activity: tokio::time::Instant,
+}
+
+enum BridgeMessage {
+    TcpData { key: SessionKey, data: Vec<u8> },
+    TcpClosed { key: SessionKey },
+    UdpData { key: SessionKey, data: Vec<u8> },
+}
+
+// ============================================================================
+// IP packet parsing helpers
+// ============================================================================
+
+fn parse_ipv4_header(packet: &[u8]) -> Option<(u8, Ipv4Addr, Ipv4Addr, u8)> {
+    if packet.len() < 20 {
+        return None;
+    }
+    let version = packet[0] >> 4;
+    if version != 4 {
+        return None;
+    }
+    let ihl = (packet[0] & 0x0F) as usize * 4;
+    let protocol = packet[9];
+    let src = Ipv4Addr::new(packet[12], packet[13], packet[14], packet[15]);
+    let dst = Ipv4Addr::new(packet[16], packet[17], packet[18], packet[19]);
+    Some((ihl as u8, src, dst, protocol))
+}
+
+fn parse_tcp_ports(packet: &[u8], ihl: usize) -> Option<(u16, u16, u8)> {
+    if packet.len() < ihl + 14 {
+        return None;
+    }
+    let src_port = u16::from_be_bytes([packet[ihl], packet[ihl + 1]]);
+    let dst_port = u16::from_be_bytes([packet[ihl + 2], packet[ihl + 3]]);
+    let flags = packet[ihl + 13];
+    Some((src_port, dst_port, flags))
+}
+
+fn parse_udp_ports(packet: &[u8], ihl: usize) -> Option<(u16, u16)> {
+    if packet.len() < ihl + 4 {
+        return None;
+    }
+    let src_port = u16::from_be_bytes([packet[ihl], packet[ihl + 1]]);
+    let dst_port = u16::from_be_bytes([packet[ihl + 2], packet[ihl + 3]]);
+    Some((src_port, dst_port))
+}
+
+// ============================================================================
+// NAT Engine
+// ============================================================================
+
+pub struct NatEngine {
+    device: VirtualIpDevice,
+    iface: Interface,
+    sockets: SocketSet<'static>,
+    tcp_sessions: HashMap<SessionKey, TcpSession>,
+    udp_sessions: HashMap<SessionKey, UdpSession>,
+    state: Arc<ServerState>,
+    bridge_rx: mpsc::Receiver<BridgeMessage>,
+    bridge_tx: mpsc::Sender<BridgeMessage>,
+    start_time: std::time::Instant,
+}
+
+impl NatEngine {
+    pub fn new(gateway_ip: Ipv4Addr, mtu: usize, state: Arc<ServerState>) -> Self {
+        let mut device = VirtualIpDevice::new(mtu);
+        let config = Config::new(HardwareAddress::Ip);
+        let now = smoltcp::time::Instant::from_millis(0);
+        let mut iface = Interface::new(config, &mut device, now);
+
+        // Accept packets to ANY destination IP (essential for NAT)
+        iface.set_any_ip(true);
+
+        // Assign the gateway IP as the interface address
+        iface.update_ip_addrs(|addrs| {
+            addrs
+                .push(IpCidr::new(IpAddress::Ipv4(gateway_ip.into()), 24))
+                .unwrap();
+        });
+
+        // Add a default route so smoltcp knows where to send packets
+        iface.routes_mut().add_default_ipv4_route(gateway_ip.into()).unwrap();
+
+        let sockets = SocketSet::new(Vec::with_capacity(256));
+        let (bridge_tx, bridge_rx) = mpsc::channel(4096);
+
+        Self {
+            device,
+            iface,
+            sockets,
+            tcp_sessions: HashMap::new(),
+            udp_sessions: HashMap::new(),
+            state,
+            bridge_rx,
+            bridge_tx,
+            start_time: std::time::Instant::now(),
+        }
+    }
+
+    fn smoltcp_now(&self) -> smoltcp::time::Instant {
+        smoltcp::time::Instant::from_millis(self.start_time.elapsed().as_millis() as i64)
+    }
+
+    /// Inject a raw IP packet from a VPN client and handle new session creation.
+    fn inject_packet(&mut self, packet: Vec<u8>) {
+        let Some((ihl, src_ip, dst_ip, protocol)) = parse_ipv4_header(&packet) else {
+            return;
+        };
+        let ihl = ihl as usize;
+
+        match protocol {
+            6 => {
+                // TCP
+                let Some((src_port, dst_port, flags)) = parse_tcp_ports(&packet, ihl) else {
+                    return;
+                };
+                let key = SessionKey {
+                    src_ip,
+                    src_port,
+                    dst_ip,
+                    dst_port,
+                    protocol: 6,
+                };
+
+                // SYN without ACK = new connection
+                let is_syn = (flags & 0x02) != 0 && (flags & 0x10) == 0;
+                if is_syn && !self.tcp_sessions.contains_key(&key) {
+                    self.create_tcp_session(&key);
+                }
+            }
+            17 => {
+                // UDP
+                let Some((src_port, dst_port)) = parse_udp_ports(&packet, ihl) else {
+                    return;
+                };
+                let key = SessionKey {
+                    src_ip,
+                    src_port,
+                    dst_ip,
+                    dst_port,
+                    protocol: 17,
+                };
+
+                if !self.udp_sessions.contains_key(&key) {
+                    self.create_udp_session(&key);
+                }
+
+                // Update last_activity for existing sessions
+                if let Some(session) = self.udp_sessions.get_mut(&key) {
+                    session.last_activity = tokio::time::Instant::now();
+                }
+            }
+            _ => {
+                // ICMP and other protocols — not forwarded in socket mode
+                return;
+            }
+        }
+
+        self.device.inject_packet(packet);
+    }
+
+    fn create_tcp_session(&mut self, key: &SessionKey) {
+        // Create smoltcp TCP socket
+        let tcp_rx_buf = tcp::SocketBuffer::new(vec![0u8; 65535]);
+        let tcp_tx_buf = tcp::SocketBuffer::new(vec![0u8; 65535]);
+        let mut socket = tcp::Socket::new(tcp_rx_buf, tcp_tx_buf);
+
+        // Listen on the destination address so smoltcp accepts the SYN
+        let endpoint = IpEndpoint::new(
+            IpAddress::Ipv4(key.dst_ip.into()),
+            key.dst_port,
+        );
+        if socket.listen(endpoint).is_err() {
+            warn!("NAT: failed to listen on {:?}", endpoint);
+            return;
+        }
+
+        let handle = self.sockets.add(socket);
+
+        // Channel for sending data from NAT engine to bridge task
+        let (data_tx, data_rx) = mpsc::channel::<Vec<u8>>(256);
+
+        let session = TcpSession {
+            smoltcp_handle: handle,
+            bridge_data_tx: data_tx,
+            client_ip: key.src_ip,
+        };
+        self.tcp_sessions.insert(key.clone(), session);
+
+        // Spawn bridge task that connects to the real destination
+        let bridge_tx = self.bridge_tx.clone();
+        let key_clone = key.clone();
+        tokio::spawn(async move {
+            tcp_bridge_task(key_clone, data_rx, bridge_tx).await;
+        });
+
+        debug!(
+            "NAT: new TCP session {}:{} -> {}:{}",
+            key.src_ip, key.src_port, key.dst_ip, key.dst_port
+        );
+    }
+
+    fn create_udp_session(&mut self, key: &SessionKey) {
+        // Create smoltcp UDP socket
+        let udp_rx_buf = udp::PacketBuffer::new(
+            vec![udp::PacketMetadata::EMPTY; 32],
+            vec![0u8; 65535],
+        );
+        let udp_tx_buf = udp::PacketBuffer::new(
+            vec![udp::PacketMetadata::EMPTY; 32],
+            vec![0u8; 65535],
+        );
+        let mut socket = udp::Socket::new(udp_rx_buf, udp_tx_buf);
+
+        let endpoint = IpEndpoint::new(
+            IpAddress::Ipv4(key.dst_ip.into()),
+            key.dst_port,
+        );
+        if socket.bind(endpoint).is_err() {
+            warn!("NAT: failed to bind UDP on {:?}", endpoint);
+            return;
+        }
+
+        let handle = self.sockets.add(socket);
+
+        let (data_tx, data_rx) = mpsc::channel::<Vec<u8>>(256);
+
+        let session = UdpSession {
+            smoltcp_handle: handle,
+            bridge_data_tx: data_tx,
+            client_ip: key.src_ip,
+            last_activity: tokio::time::Instant::now(),
+        };
+        self.udp_sessions.insert(key.clone(), session);
+
+        let bridge_tx = self.bridge_tx.clone();
+        let key_clone = key.clone();
+        tokio::spawn(async move {
+            udp_bridge_task(key_clone, data_rx, bridge_tx).await;
+        });
+
+        debug!(
+            "NAT: new UDP session {}:{} -> {}:{}",
+            key.src_ip, key.src_port, key.dst_ip, key.dst_port
+        );
+    }
+
+    /// Poll smoltcp, bridge data between smoltcp sockets and bridge tasks,
+    /// and dispatch outgoing packets to VPN clients.
+    async fn process(&mut self) {
+        let now = self.smoltcp_now();
+        self.iface
+            .poll(now, &mut self.device, &mut self.sockets);
+
+        // Bridge: read data from smoltcp TCP sockets → send to bridge tasks
+        let mut closed_tcp: Vec<SessionKey> = Vec::new();
+        for (key, session) in &self.tcp_sessions {
+            let socket = self.sockets.get_mut::<tcp::Socket>(session.smoltcp_handle);
+            if socket.can_recv() {
+                let _ = socket.recv(|data| {
+                    let _ = session.bridge_data_tx.try_send(data.to_vec());
+                    (data.len(), ())
+                });
+            }
+            // Detect closed connections
+            if !socket.is_open() && !socket.is_listening() {
+                closed_tcp.push(key.clone());
+            }
+        }
+
+        // Clean up closed TCP sessions
+        for key in closed_tcp {
+            if let Some(session) = self.tcp_sessions.remove(&key) {
+                self.sockets.remove(session.smoltcp_handle);
+                debug!("NAT: TCP session closed {}:{} -> {}:{}", key.src_ip, key.src_port, key.dst_ip, key.dst_port);
+            }
+        }
+
+        // Bridge: read data from smoltcp UDP sockets → send to bridge tasks
+        for (_key, session) in &self.udp_sessions {
+            let socket = self.sockets.get_mut::<udp::Socket>(session.smoltcp_handle);
+            while let Ok((data, _meta)) = socket.recv() {
+                let _ = session.bridge_data_tx.try_send(data.to_vec());
+            }
+        }
+
+        // Dispatch outgoing packets from smoltcp to VPN clients
+        let routes = self.state.tun_routes.read().await;
+        for packet in self.device.drain_tx() {
+            if let Some(std::net::IpAddr::V4(dst_ip)) = tunnel::extract_dst_ip(&packet) {
+                if let Some(sender) = routes.get(&dst_ip) {
+                    let _ = sender.try_send(packet);
+                }
+            }
+        }
+    }
+
+    fn handle_bridge_message(&mut self, msg: BridgeMessage) {
+        match msg {
+            BridgeMessage::TcpData { key, data } => {
+                if let Some(session) = self.tcp_sessions.get(&key) {
+                    let socket =
+                        self.sockets.get_mut::<tcp::Socket>(session.smoltcp_handle);
+                    if socket.can_send() {
+                        let _ = socket.send_slice(&data);
+                    }
+                }
+            }
+            BridgeMessage::TcpClosed { key } => {
+                if let Some(session) = self.tcp_sessions.remove(&key) {
+                    let socket =
+                        self.sockets.get_mut::<tcp::Socket>(session.smoltcp_handle);
+                    socket.close();
+                    // Don't remove from SocketSet yet — let smoltcp send FIN
+                    // It will be cleaned up in process() when is_open() returns false
+                    self.tcp_sessions.insert(key, session);
+                }
+            }
+            BridgeMessage::UdpData { key, data } => {
+                if let Some(session) = self.udp_sessions.get_mut(&key) {
+                    session.last_activity = tokio::time::Instant::now();
+                    let socket =
+                        self.sockets.get_mut::<udp::Socket>(session.smoltcp_handle);
+                    let dst_endpoint = IpEndpoint::new(
+                        IpAddress::Ipv4(key.src_ip.into()),
+                        key.src_port,
+                    );
+                    // Send response: from the "server" (dst) back to the "client" (src)
+                    let _ = socket.send_slice(&data, dst_endpoint);
+                }
+            }
+        }
+    }
+
+    fn cleanup_idle_udp_sessions(&mut self) {
+        let timeout = Duration::from_secs(60);
+        let now = tokio::time::Instant::now();
+        let expired: Vec<SessionKey> = self
+            .udp_sessions
+            .iter()
+            .filter(|(_, s)| now.duration_since(s.last_activity) > timeout)
+            .map(|(k, _)| k.clone())
+            .collect();
+
+        for key in expired {
+            if let Some(session) = self.udp_sessions.remove(&key) {
+                self.sockets.remove(session.smoltcp_handle);
+                debug!(
+                    "NAT: UDP session timed out {}:{} -> {}:{}",
+                    key.src_ip, key.src_port, key.dst_ip, key.dst_port
+                );
+            }
+        }
+    }
+
+    /// Main async event loop for the NAT engine.
+    pub async fn run(
+        mut self,
+        mut packet_rx: mpsc::Receiver<Vec<u8>>,
+        mut shutdown_rx: mpsc::Receiver<()>,
+    ) -> Result<()> {
+        info!("Userspace NAT engine started");
+        let mut timer = tokio::time::interval(Duration::from_millis(50));
+        let mut cleanup_timer = tokio::time::interval(Duration::from_secs(10));
+
+        loop {
+            tokio::select! {
+                Some(packet) = packet_rx.recv() => {
+                    self.inject_packet(packet);
+                    self.process().await;
+                }
+                Some(msg) = self.bridge_rx.recv() => {
+                    self.handle_bridge_message(msg);
+                    self.process().await;
+                }
+                _ = timer.tick() => {
+                    // Periodic poll for smoltcp maintenance (TCP retransmit, etc.)
+                    self.process().await;
+                }
+                _ = cleanup_timer.tick() => {
+                    self.cleanup_idle_udp_sessions();
+                }
+                _ = shutdown_rx.recv() => {
+                    info!("Userspace NAT engine shutting down");
+                    break;
+                }
+            }
+        }
+
+        Ok(())
+    }
+}
+
+// ============================================================================
+// Bridge tasks
+// ============================================================================
+
+async fn tcp_bridge_task(
+    key: SessionKey,
+    mut data_rx: mpsc::Receiver<Vec<u8>>,
+    bridge_tx: mpsc::Sender<BridgeMessage>,
+) {
+    let addr = SocketAddr::new(key.dst_ip.into(), key.dst_port);
+
+    // Connect to real destination with timeout
+    let stream = match tokio::time::timeout(Duration::from_secs(30), TcpStream::connect(addr)).await
+    {
+        Ok(Ok(s)) => s,
+        Ok(Err(e)) => {
+            debug!("NAT TCP connect to {} failed: {}", addr, e);
+            let _ = bridge_tx.send(BridgeMessage::TcpClosed { key }).await;
+            return;
+        }
+        Err(_) => {
+            debug!("NAT TCP connect to {} timed out", addr);
+            let _ = bridge_tx.send(BridgeMessage::TcpClosed { key }).await;
+            return;
+        }
+    };
+
+    let (mut reader, mut writer) = stream.into_split();
+
+    // Read from real socket → send to NAT engine
+    let bridge_tx2 = bridge_tx.clone();
+    let key2 = key.clone();
+    let read_task = tokio::spawn(async move {
+        let mut buf = vec![0u8; 65536];
+        loop {
+            match reader.read(&mut buf).await {
+                Ok(0) => break,
+                Ok(n) => {
+                    if bridge_tx2
+                        .send(BridgeMessage::TcpData {
+                            key: key2.clone(),
+                            data: buf[..n].to_vec(),
+                        })
+                        .await
+                        .is_err()
+                    {
+                        break;
+                    }
+                }
+                Err(_) => break,
+            }
+        }
+        let _ = bridge_tx2
+            .send(BridgeMessage::TcpClosed { key: key2 })
+            .await;
+    });
+
+    // Receive from NAT engine → write to real socket
+    while let Some(data) = data_rx.recv().await {
+        if writer.write_all(&data).await.is_err() {
+            break;
+        }
+    }
+
+    read_task.abort();
+}
+
+async fn udp_bridge_task(
+    key: SessionKey,
+    mut data_rx: mpsc::Receiver<Vec<u8>>,
+    bridge_tx: mpsc::Sender<BridgeMessage>,
+) {
+    let socket = match UdpSocket::bind("0.0.0.0:0").await {
+        Ok(s) => s,
+        Err(e) => {
+            warn!("NAT UDP bind failed: {}", e);
+            return;
+        }
+    };
+    let dest = SocketAddr::new(key.dst_ip.into(), key.dst_port);
+
+    let socket = Arc::new(socket);
+    let socket2 = socket.clone();
+    let bridge_tx2 = bridge_tx.clone();
+    let key2 = key.clone();
+
+    // Read responses from real socket
+    let read_task = tokio::spawn(async move {
+        let mut buf = vec![0u8; 65536];
+        loop {
+            match socket2.recv_from(&mut buf).await {
+                Ok((n, _src)) => {
+                    if bridge_tx2
+                        .send(BridgeMessage::UdpData {
+                            key: key2.clone(),
+                            data: buf[..n].to_vec(),
+                        })
+                        .await
+                        .is_err()
+                    {
+                        break;
+                    }
+                }
+                Err(_) => break,
+            }
+        }
+    });
+
+    // Forward data from NAT engine to real socket
+    while let Some(data) = data_rx.recv().await {
+        let _ = socket.send_to(&data, dest).await;
+    }
+
+    read_task.abort();
+}

rust/tests/wg_e2e.rs

@@ -0,0 +1,320 @@
+//! End-to-end WireGuard protocol tests over real UDP sockets.
+//!
+//! Entirely userspace — no root, no TUN devices.
+//! Two boringtun `Tunn` instances exchange real WireGuard packets
+//! over loopback UDP, validating handshake, encryption, and data flow.
+
+use std::net::{Ipv4Addr, SocketAddr};
+use std::time::Duration;
+
+use boringtun::noise::{Tunn, TunnResult};
+use boringtun::x25519::{PublicKey, StaticSecret};
+use tokio::net::UdpSocket;
+use tokio::time;
+
+use base64::engine::general_purpose::STANDARD as BASE64;
+use base64::Engine;
+
+use smartvpn_daemon::wireguard::generate_wg_keypair;
+
+// ============================================================================
+// Helpers
+// ============================================================================
+
+fn parse_key_pair(pub_b64: &str, priv_b64: &str) -> (PublicKey, StaticSecret) {
+    let pub_bytes: [u8; 32] = BASE64.decode(pub_b64).unwrap().try_into().unwrap();
+    let priv_bytes: [u8; 32] = BASE64.decode(priv_b64).unwrap().try_into().unwrap();
+    (PublicKey::from(pub_bytes), StaticSecret::from(priv_bytes))
+}
+
+fn clone_secret(priv_b64: &str) -> StaticSecret {
+    let priv_bytes: [u8; 32] = BASE64.decode(priv_b64).unwrap().try_into().unwrap();
+    StaticSecret::from(priv_bytes)
+}
+
+fn make_ipv4_packet(src: Ipv4Addr, dst: Ipv4Addr, payload: &[u8]) -> Vec<u8> {
+    let total_len = 20 + payload.len();
+    let mut pkt = vec![0u8; total_len];
+    pkt[0] = 0x45;
+    pkt[2] = (total_len >> 8) as u8;
+    pkt[3] = total_len as u8;
+    pkt[9] = 0x11;
+    pkt[12..16].copy_from_slice(&src.octets());
+    pkt[16..20].copy_from_slice(&dst.octets());
+    pkt[20..].copy_from_slice(payload);
+    pkt
+}
+
+/// Send any WriteToNetwork result, then drain the tunn for more packets.
+async fn send_and_drain(
+    tunn: &mut Tunn,
+    pkt: &[u8],
+    socket: &UdpSocket,
+    peer: SocketAddr,
+) {
+    socket.send_to(pkt, peer).await.unwrap();
+    let mut drain_buf = vec![0u8; 2048];
+    loop {
+        match tunn.decapsulate(None, &[], &mut drain_buf) {
+            TunnResult::WriteToNetwork(p) => { socket.send_to(p, peer).await.unwrap(); }
+            _ => break,
+        }
+    }
+}
+
+/// Try to receive a UDP packet and decapsulate it. Returns decrypted IP data if any.
+async fn try_recv_decap(
+    tunn: &mut Tunn,
+    socket: &UdpSocket,
+    timeout_ms: u64,
+) -> Option<(Vec<u8>, Ipv4Addr, SocketAddr)> {
+    let mut recv_buf = vec![0u8; 65536];
+    let mut dst_buf = vec![0u8; 65536];
+
+    let (n, src_addr) = match time::timeout(
+        Duration::from_millis(timeout_ms),
+        socket.recv_from(&mut recv_buf),
+    ).await {
+        Ok(Ok(r)) => r,
+        _ => return None,
+    };
+
+    let result = tunn.decapsulate(Some(src_addr.ip()), &recv_buf[..n], &mut dst_buf);
+    match result {
+        TunnResult::WriteToNetwork(pkt) => {
+            send_and_drain(tunn, pkt, socket, src_addr).await;
+            None
+        }
+        TunnResult::WriteToTunnelV4(pkt, addr) => Some((pkt.to_vec(), addr, src_addr)),
+        TunnResult::WriteToTunnelV6(_, _) => None,
+        TunnResult::Done => None,
+        TunnResult::Err(_) => None,
+    }
+}
+
+/// Drive the full WireGuard handshake between client and server over real UDP.
+async fn do_handshake(
+    client_tunn: &mut Tunn,
+    server_tunn: &mut Tunn,
+    client_socket: &UdpSocket,
+    server_socket: &UdpSocket,
+    server_addr: SocketAddr,
+) {
+    let mut buf = vec![0u8; 2048];
+    let mut recv_buf = vec![0u8; 65536];
+    let mut dst_buf = vec![0u8; 65536];
+
+    // Step 1: Client initiates handshake
+    match client_tunn.encapsulate(&[], &mut buf) {
+        TunnResult::WriteToNetwork(pkt) => {
+            client_socket.send_to(pkt, server_addr).await.unwrap();
+        }
+        _ => panic!("Expected handshake init"),
+    }
+
+    // Step 2: Server receives init → sends response
+    let (n, client_from) = server_socket.recv_from(&mut recv_buf).await.unwrap();
+    match server_tunn.decapsulate(Some(client_from.ip()), &recv_buf[..n], &mut dst_buf) {
+        TunnResult::WriteToNetwork(pkt) => {
+            send_and_drain(server_tunn, pkt, server_socket, client_from).await;
+        }
+        other => panic!("Expected WriteToNetwork from server, got variant {}", variant_name(&other)),
+    }
+
+    // Step 3: Client receives response
+    let (n, _) = client_socket.recv_from(&mut recv_buf).await.unwrap();
+    match client_tunn.decapsulate(Some(server_addr.ip()), &recv_buf[..n], &mut dst_buf) {
+        TunnResult::WriteToNetwork(pkt) => {
+            send_and_drain(client_tunn, pkt, client_socket, server_addr).await;
+        }
+        TunnResult::Done => {}
+        _ => {}
+    }
+
+    // Step 4: Process any remaining handshake packets
+    let _ = try_recv_decap(server_tunn, server_socket, 200).await;
+    let _ = try_recv_decap(client_tunn, client_socket, 100).await;
+
+    // Step 5: Timer ticks to settle
+    for _ in 0..3 {
+        match server_tunn.update_timers(&mut dst_buf) {
+            TunnResult::WriteToNetwork(pkt) => {
+                server_socket.send_to(pkt, client_from).await.unwrap();
+            }
+            _ => {}
+        }
+        match client_tunn.update_timers(&mut dst_buf) {
+            TunnResult::WriteToNetwork(pkt) => {
+                client_socket.send_to(pkt, server_addr).await.unwrap();
+            }
+            _ => {}
+        }
+        let _ = try_recv_decap(server_tunn, server_socket, 50).await;
+        let _ = try_recv_decap(client_tunn, client_socket, 50).await;
+    }
+}
+
+fn variant_name(r: &TunnResult) -> &'static str {
+    match r {
+        TunnResult::Done => "Done",
+        TunnResult::Err(_) => "Err",
+        TunnResult::WriteToNetwork(_) => "WriteToNetwork",
+        TunnResult::WriteToTunnelV4(_, _) => "WriteToTunnelV4",
+        TunnResult::WriteToTunnelV6(_, _) => "WriteToTunnelV6",
+    }
+}
+
+/// Encapsulate an IP packet and send it, then loop-receive on the other side until decrypted.
+async fn send_and_expect_data(
+    sender_tunn: &mut Tunn,
+    receiver_tunn: &mut Tunn,
+    sender_socket: &UdpSocket,
+    receiver_socket: &UdpSocket,
+    dest_addr: SocketAddr,
+    ip_packet: &[u8],
+) -> (Vec<u8>, Ipv4Addr) {
+    let mut enc_buf = vec![0u8; 65536];
+
+    match sender_tunn.encapsulate(ip_packet, &mut enc_buf) {
+        TunnResult::WriteToNetwork(pkt) => {
+            sender_socket.send_to(pkt, dest_addr).await.unwrap();
+        }
+        TunnResult::Err(e) => panic!("Encapsulate failed: {:?}", e),
+        other => panic!("Expected WriteToNetwork, got {}", variant_name(&other)),
+    }
+
+    // Receive — may need a few rounds for control packets
+    for _ in 0..10 {
+        if let Some((data, addr, _)) = try_recv_decap(receiver_tunn, receiver_socket, 1000).await {
+            return (data, addr);
+        }
+    }
+    panic!("Did not receive decrypted IP packet");
+}
+
+// ============================================================================
+// Test 1: Single client ↔ server bidirectional data exchange
+// ============================================================================
+
+#[tokio::test]
+async fn wg_e2e_single_client_bidirectional() {
+    let (server_pub_b64, server_priv_b64) = generate_wg_keypair();
+    let (client_pub_b64, client_priv_b64) = generate_wg_keypair();
+
+    let (server_public, server_secret) = parse_key_pair(&server_pub_b64, &server_priv_b64);
+    let (client_public, client_secret) = parse_key_pair(&client_pub_b64, &client_priv_b64);
+
+    let server_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+    let client_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+    let server_addr = server_socket.local_addr().unwrap();
+    let client_addr = client_socket.local_addr().unwrap();
+
+    let mut server_tunn = Tunn::new(server_secret, client_public, None, None, 0, None);
+    let mut client_tunn = Tunn::new(client_secret, server_public, None, None, 1, None);
+
+    do_handshake(&mut client_tunn, &mut server_tunn, &client_socket, &server_socket, server_addr).await;
+
+    // Client → Server
+    let pkt_c2s = make_ipv4_packet(Ipv4Addr::new(10, 0, 0, 2), Ipv4Addr::new(10, 0, 0, 1), b"Hello from client!");
+    let (decrypted, src_ip) = send_and_expect_data(
+        &mut client_tunn, &mut server_tunn,
+        &client_socket, &server_socket,
+        server_addr, &pkt_c2s,
+    ).await;
+    assert_eq!(src_ip, Ipv4Addr::new(10, 0, 0, 2));
+    assert_eq!(&decrypted[..pkt_c2s.len()], &pkt_c2s[..]);
+
+    // Server → Client
+    let pkt_s2c = make_ipv4_packet(Ipv4Addr::new(10, 0, 0, 1), Ipv4Addr::new(10, 0, 0, 2), b"Hello from server!");
+    let (decrypted, src_ip) = send_and_expect_data(
+        &mut server_tunn, &mut client_tunn,
+        &server_socket, &client_socket,
+        client_addr, &pkt_s2c,
+    ).await;
+    assert_eq!(src_ip, Ipv4Addr::new(10, 0, 0, 1));
+    assert_eq!(&decrypted[..pkt_s2c.len()], &pkt_s2c[..]);
+}
+
+// ============================================================================
+// Test 2: Two clients ↔ one server (peer routing)
+// ============================================================================
+
+#[tokio::test]
+async fn wg_e2e_two_clients_peer_routing() {
+    let (server_pub_b64, server_priv_b64) = generate_wg_keypair();
+    let (client1_pub_b64, client1_priv_b64) = generate_wg_keypair();
+    let (client2_pub_b64, client2_priv_b64) = generate_wg_keypair();
+
+    let (server_public, _) = parse_key_pair(&server_pub_b64, &server_priv_b64);
+    let (client1_public, client1_secret) = parse_key_pair(&client1_pub_b64, &client1_priv_b64);
+    let (client2_public, client2_secret) = parse_key_pair(&client2_pub_b64, &client2_priv_b64);
+
+    // Separate server socket per peer to avoid UDP mux complexity in test
+    let server_socket_1 = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+    let server_socket_2 = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+    let client1_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+    let client2_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+    let server_addr_1 = server_socket_1.local_addr().unwrap();
+    let server_addr_2 = server_socket_2.local_addr().unwrap();
+
+    let mut server_tunn_1 = Tunn::new(clone_secret(&server_priv_b64), client1_public, None, None, 0, None);
+    let mut server_tunn_2 = Tunn::new(clone_secret(&server_priv_b64), client2_public, None, None, 1, None);
+    let mut client1_tunn = Tunn::new(client1_secret, server_public.clone(), None, None, 2, None);
+    let mut client2_tunn = Tunn::new(client2_secret, server_public, None, None, 3, None);
+
+    do_handshake(&mut client1_tunn, &mut server_tunn_1, &client1_socket, &server_socket_1, server_addr_1).await;
+    do_handshake(&mut client2_tunn, &mut server_tunn_2, &client2_socket, &server_socket_2, server_addr_2).await;
+
+    // Client 1 → Server
+    let pkt1 = make_ipv4_packet(Ipv4Addr::new(10, 0, 0, 2), Ipv4Addr::new(10, 0, 0, 1), b"From client 1");
+    let (decrypted, src_ip) = send_and_expect_data(
+        &mut client1_tunn, &mut server_tunn_1,
+        &client1_socket, &server_socket_1,
+        server_addr_1, &pkt1,
+    ).await;
+    assert_eq!(src_ip, Ipv4Addr::new(10, 0, 0, 2));
+    assert_eq!(&decrypted[..pkt1.len()], &pkt1[..]);
+
+    // Client 2 → Server
+    let pkt2 = make_ipv4_packet(Ipv4Addr::new(10, 0, 0, 3), Ipv4Addr::new(10, 0, 0, 1), b"From client 2");
+    let (decrypted, src_ip) = send_and_expect_data(
+        &mut client2_tunn, &mut server_tunn_2,
+        &client2_socket, &server_socket_2,
+        server_addr_2, &pkt2,
+    ).await;
+    assert_eq!(src_ip, Ipv4Addr::new(10, 0, 0, 3));
+    assert_eq!(&decrypted[..pkt2.len()], &pkt2[..]);
+}
+
+// ============================================================================
+// Test 3: Preshared key handshake + data exchange
+// ============================================================================
+
+#[tokio::test]
+async fn wg_e2e_preshared_key() {
+    let (server_pub_b64, server_priv_b64) = generate_wg_keypair();
+    let (client_pub_b64, client_priv_b64) = generate_wg_keypair();
+
+    let (server_public, server_secret) = parse_key_pair(&server_pub_b64, &server_priv_b64);
+    let (client_public, client_secret) = parse_key_pair(&client_pub_b64, &client_priv_b64);
+
+    let psk: [u8; 32] = rand::random();
+
+    let server_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+    let client_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+    let server_addr = server_socket.local_addr().unwrap();
+
+    let mut server_tunn = Tunn::new(server_secret, client_public, Some(psk), None, 0, None);
+    let mut client_tunn = Tunn::new(client_secret, server_public, Some(psk), None, 1, None);
+
+    do_handshake(&mut client_tunn, &mut server_tunn, &client_socket, &server_socket, server_addr).await;
+
+    let pkt = make_ipv4_packet(Ipv4Addr::new(10, 0, 0, 2), Ipv4Addr::new(10, 0, 0, 1), b"PSK-protected data");
+    let (decrypted, src_ip) = send_and_expect_data(
+        &mut client_tunn, &mut server_tunn,
+        &client_socket, &server_socket,
+        server_addr, &pkt,
+    ).await;
+    assert_eq!(src_ip, Ipv4Addr::new(10, 0, 0, 2));
+    assert_eq!(&decrypted[..pkt.len()], &pkt[..]);
+}

test/test.flowcontrol.node.ts

@@ -0,0 +1,284 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import * as net from 'net';
+import { VpnClient, VpnServer } from '../ts/index.js';
+import type { IVpnClientOptions, IVpnServerOptions, IVpnKeypair, IVpnServerConfig, IClientConfigBundle } from '../ts/index.js';
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+async function findFreePort(): Promise<number> {
+  const server = net.createServer();
+  await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve));
+  const port = (server.address() as net.AddressInfo).port;
+  await new Promise<void>((resolve) => server.close(() => resolve()));
+  return port;
+}
+
+function delay(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function waitFor(
+  fn: () => Promise<boolean>,
+  timeoutMs: number = 10000,
+  pollMs: number = 500,
+): Promise<void> {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    if (await fn()) return;
+    await delay(pollMs);
+  }
+  throw new Error(`waitFor timed out after ${timeoutMs}ms`);
+}
+
+// ---------------------------------------------------------------------------
+// Test state
+// ---------------------------------------------------------------------------
+
+let server: VpnServer;
+let serverPort: number;
+let keypair: IVpnKeypair;
+let client: VpnClient;
+let clientBundle: IClientConfigBundle;
+const extraClients: VpnClient[] = [];
+const extraBundles: IClientConfigBundle[] = [];
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+tap.test('setup: start VPN server', async () => {
+  serverPort = await findFreePort();
+
+  const options: IVpnServerOptions = {
+    transport: { transport: 'stdio' },
+  };
+  server = new VpnServer(options);
+
+  // Phase 1: start the daemon bridge
+  const started = await server['bridge'].start();
+  expect(started).toBeTrue();
+  expect(server.running).toBeTrue();
+
+  // Phase 2: generate a keypair
+  keypair = await server.generateKeypair();
+  expect(keypair.publicKey).toBeTypeofString();
+  expect(keypair.privateKey).toBeTypeofString();
+
+  // Phase 3: start the VPN listener (empty clients, will use createClient at runtime)
+  const serverConfig: IVpnServerConfig = {
+    listenAddr: `127.0.0.1:${serverPort}`,
+    privateKey: keypair.privateKey,
+    publicKey: keypair.publicKey,
+    subnet: '10.8.0.0/24',
+  };
+  await server['bridge'].sendCommand('start', { config: serverConfig });
+
+  // Verify server is now running
+  const status = await server.getStatus();
+  expect(status.state).toEqual('connected');
+
+  // Phase 4: create the first client via the hub
+  clientBundle = await server.createClient({ clientId: 'test-client-0' });
+  expect(clientBundle.secrets.noisePrivateKey).toBeTypeofString();
+  expect(clientBundle.smartvpnConfig.clientPublicKey).toBeTypeofString();
+});
+
+tap.test('single client connects and gets IP', async () => {
+  const options: IVpnClientOptions = {
+    transport: { transport: 'stdio' },
+  };
+  client = new VpnClient(options);
+  const started = await client.start();
+  expect(started).toBeTrue();
+
+  const result = await client.connect({
+    serverUrl: `ws://127.0.0.1:${serverPort}`,
+    serverPublicKey: keypair.publicKey,
+    clientPrivateKey: clientBundle.secrets.noisePrivateKey,
+    clientPublicKey: clientBundle.smartvpnConfig.clientPublicKey,
+    keepaliveIntervalSecs: 3,
+  });
+
+  expect(result.assignedIp).toBeTypeofString();
+  expect(result.assignedIp).toStartWith('10.8.0.');
+
+  // Verify client status
+  const clientStatus = await client.getStatus();
+  expect(clientStatus.state).toEqual('connected');
+
+  // Verify server sees the client
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length === 1;
+  });
+  const clients = await server.listClients();
+  expect(clients.length).toEqual(1);
+  expect(clients[0].assignedIp).toEqual(result.assignedIp);
+});
+
+tap.test('keepalive exchange', async () => {
+  // Wait for at least 2 keepalive cycles (interval=3s, so 8s should be enough)
+  await delay(8000);
+
+  const clientStats = await client.getStatistics();
+  expect(clientStats.keepalivesSent).toBeGreaterThanOrEqual(1);
+  expect(clientStats.keepalivesReceived).toBeGreaterThanOrEqual(1);
+
+  const serverStats = await server.getStatistics();
+  expect(serverStats.keepalivesReceived).toBeGreaterThanOrEqual(1);
+  expect(serverStats.keepalivesSent).toBeGreaterThanOrEqual(1);
+
+  // Verify per-client keepalive tracking
+  const clients = await server.listClients();
+  expect(clients[0].keepalivesReceived).toBeGreaterThanOrEqual(1);
+});
+
+tap.test('connection quality telemetry', async () => {
+  const quality = await client.getConnectionQuality();
+
+  expect(quality.srttMs).toBeGreaterThanOrEqual(0);
+  expect(quality.jitterMs).toBeTypeofNumber();
+  expect(quality.minRttMs).toBeGreaterThanOrEqual(0);
+  expect(quality.maxRttMs).toBeGreaterThanOrEqual(0);
+  expect(quality.lossRatio).toBeTypeofNumber();
+  expect(['healthy', 'degraded', 'critical']).toContain(quality.linkHealth);
+});
+
+tap.test('rate limiting: set and verify', async () => {
+  const clients = await server.listClients();
+  const clientId = clients[0].clientId;
+
+  // Set a tight rate limit
+  await server.setClientRateLimit(clientId, 100, 100);
+
+  // Verify via telemetry
+  const telemetry = await server.getClientTelemetry(clientId);
+  expect(telemetry.rateLimitBytesPerSec).toEqual(100);
+  expect(telemetry.burstBytes).toEqual(100);
+  expect(telemetry.clientId).toEqual(clientId);
+});
+
+tap.test('rate limiting: removal', async () => {
+  const clients = await server.listClients();
+  const clientId = clients[0].clientId;
+
+  await server.removeClientRateLimit(clientId);
+
+  // Verify telemetry no longer shows rate limit
+  const telemetry = await server.getClientTelemetry(clientId);
+  expect(telemetry.rateLimitBytesPerSec).toBeNullOrUndefined();
+  expect(telemetry.burstBytes).toBeNullOrUndefined();
+
+  // Connection still healthy
+  const status = await client.getStatus();
+  expect(status.state).toEqual('connected');
+});
+
+tap.test('5 concurrent clients', async () => {
+  const assignedIps = new Set<string>();
+
+  // Get the first client's IP
+  const existingClients = await server.listClients();
+  assignedIps.add(existingClients[0].assignedIp);
+
+  for (let i = 0; i < 5; i++) {
+    const bundle = await server.createClient({ clientId: `test-client-${i + 1}` });
+    extraBundles.push(bundle);
+    const c = new VpnClient({ transport: { transport: 'stdio' } });
+    await c.start();
+    const result = await c.connect({
+      serverUrl: `ws://127.0.0.1:${serverPort}`,
+      serverPublicKey: keypair.publicKey,
+      clientPrivateKey: bundle.secrets.noisePrivateKey,
+      clientPublicKey: bundle.smartvpnConfig.clientPublicKey,
+      keepaliveIntervalSecs: 3,
+    });
+    expect(result.assignedIp).toStartWith('10.8.0.');
+    assignedIps.add(result.assignedIp);
+    extraClients.push(c);
+  }
+
+  // All IPs should be unique (6 total: original + 5 new)
+  expect(assignedIps.size).toEqual(6);
+
+  // Server should see 6 clients
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length === 6;
+  });
+  const allClients = await server.listClients();
+  expect(allClients.length).toEqual(6);
+});
+
+tap.test('client disconnect tracking', async () => {
+  // Disconnect 3 of the 5 extra clients
+  for (let i = 0; i < 3; i++) {
+    const c = extraClients[i];
+    await c.disconnect();
+    c.stop();
+  }
+
+  // Wait for server to detect disconnections
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length === 3;
+  }, 15000);
+
+  const clients = await server.listClients();
+  expect(clients.length).toEqual(3);
+
+  const stats = await server.getStatistics();
+  expect(stats.totalConnections).toBeGreaterThanOrEqual(6);
+});
+
+tap.test('server-side client disconnection', async () => {
+  const clients = await server.listClients();
+  // Pick one of the remaining extra clients (not the original)
+  const targetClient = clients.find((c) => {
+    // Find a client that belongs to extraClients[3] or extraClients[4]
+    return c.clientId !== clients[0].clientId;
+  });
+  expect(targetClient).toBeTruthy();
+
+  await server.disconnectClient(targetClient!.clientId);
+
+  // Wait for server to update
+  await waitFor(async () => {
+    const remaining = await server.listClients();
+    return remaining.length === 2;
+  });
+
+  const remaining = await server.listClients();
+  expect(remaining.length).toEqual(2);
+});
+
+tap.test('teardown: stop all', async () => {
+  // Stop the original client
+  await client.disconnect();
+  client.stop();
+
+  // Stop remaining extra clients
+  for (const c of extraClients) {
+    if (c.running) {
+      try {
+        await c.disconnect();
+      } catch {
+        // May already be disconnected
+      }
+      c.stop();
+    }
+  }
+
+  await delay(500);
+
+  // Stop the server
+  await server.stopServer();
+  server.stop();
+  await delay(500);
+
+  expect(server.running).toBeFalse();
+});
+
+export default tap.start();

test/test.loadtest.node.ts

@@ -0,0 +1,362 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import * as net from 'net';
+import * as stream from 'stream';
+import { VpnClient, VpnServer } from '../ts/index.js';
+import type { IVpnKeypair, IVpnServerConfig } from '../ts/index.js';
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+async function findFreePort(): Promise<number> {
+  const server = net.createServer();
+  await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve));
+  const port = (server.address() as net.AddressInfo).port;
+  await new Promise<void>((resolve) => server.close(() => resolve()));
+  return port;
+}
+
+function delay(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function waitFor(
+  fn: () => Promise<boolean>,
+  timeoutMs: number = 10000,
+  pollMs: number = 500,
+): Promise<void> {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    if (await fn()) return;
+    await delay(pollMs);
+  }
+  throw new Error(`waitFor timed out after ${timeoutMs}ms`);
+}
+
+// ---------------------------------------------------------------------------
+// ThrottleProxy (adapted from remoteingress)
+// ---------------------------------------------------------------------------
+
+class ThrottleTransform extends stream.Transform {
+  private bytesPerSec: number;
+  private bucket: number;
+  private lastRefill: number;
+  private destroyed_: boolean = false;
+
+  constructor(bytesPerSecond: number) {
+    super();
+    this.bytesPerSec = bytesPerSecond;
+    this.bucket = bytesPerSecond;
+    this.lastRefill = Date.now();
+  }
+
+  _transform(chunk: Buffer, _encoding: BufferEncoding, callback: stream.TransformCallback) {
+    if (this.destroyed_) return;
+
+    const now = Date.now();
+    const elapsed = (now - this.lastRefill) / 1000;
+    this.bucket = Math.min(this.bytesPerSec, this.bucket + elapsed * this.bytesPerSec);
+    this.lastRefill = now;
+
+    if (chunk.length <= this.bucket) {
+      this.bucket -= chunk.length;
+      callback(null, chunk);
+    } else {
+      const deficit = chunk.length - this.bucket;
+      this.bucket = 0;
+      const delayMs = Math.min((deficit / this.bytesPerSec) * 1000, 1000);
+      setTimeout(() => {
+        if (this.destroyed_) { callback(); return; }
+        this.lastRefill = Date.now();
+        this.bucket = 0;
+        callback(null, chunk);
+      }, delayMs);
+    }
+  }
+
+  _destroy(err: Error | null, callback: (error: Error | null) => void) {
+    this.destroyed_ = true;
+    callback(err);
+  }
+}
+
+interface ThrottleProxy {
+  server: net.Server;
+  close: () => Promise<void>;
+}
+
+async function startThrottleProxy(
+  listenPort: number,
+  targetHost: string,
+  targetPort: number,
+  bytesPerSecond: number,
+): Promise<ThrottleProxy> {
+  const connections = new Set<net.Socket>();
+  const server = net.createServer((clientSock) => {
+    connections.add(clientSock);
+    const upstream = net.createConnection({ host: targetHost, port: targetPort });
+    connections.add(upstream);
+
+    const throttleUp = new ThrottleTransform(bytesPerSecond);
+    const throttleDown = new ThrottleTransform(bytesPerSecond);
+
+    clientSock.pipe(throttleUp).pipe(upstream);
+    upstream.pipe(throttleDown).pipe(clientSock);
+
+    let cleaned = false;
+    const cleanup = () => {
+      if (cleaned) return;
+      cleaned = true;
+      throttleUp.destroy();
+      throttleDown.destroy();
+      clientSock.destroy();
+      upstream.destroy();
+      connections.delete(clientSock);
+      connections.delete(upstream);
+    };
+    clientSock.on('error', () => cleanup());
+    upstream.on('error', () => cleanup());
+    throttleUp.on('error', () => cleanup());
+    throttleDown.on('error', () => cleanup());
+    clientSock.on('close', () => cleanup());
+    upstream.on('close', () => cleanup());
+  });
+
+  await new Promise<void>((resolve) => server.listen(listenPort, '127.0.0.1', resolve));
+  return {
+    server,
+    close: async () => {
+      for (const c of connections) c.destroy();
+      connections.clear();
+      await new Promise<void>((resolve) => server.close(() => resolve()));
+    },
+  };
+}
+
+// ---------------------------------------------------------------------------
+// Test state
+// ---------------------------------------------------------------------------
+
+let server: VpnServer;
+let serverPort: number;
+let proxyPort: number;
+let keypair: IVpnKeypair;
+let throttle: ThrottleProxy;
+const allClients: VpnClient[] = [];
+
+let clientCounter = 0;
+async function createConnectedClient(port: number): Promise<VpnClient> {
+  clientCounter++;
+  const bundle = await server.createClient({ clientId: `load-client-${clientCounter}` });
+  const c = new VpnClient({ transport: { transport: 'stdio' } });
+  await c.start();
+  await c.connect({
+    serverUrl: `ws://127.0.0.1:${port}`,
+    serverPublicKey: keypair.publicKey,
+    clientPrivateKey: bundle.secrets.noisePrivateKey,
+    clientPublicKey: bundle.smartvpnConfig.clientPublicKey,
+    keepaliveIntervalSecs: 3,
+  });
+  allClients.push(c);
+  return c;
+}
+
+async function stopClient(c: VpnClient): Promise<void> {
+  if (c.running) {
+    try { await c.disconnect(); } catch { /* already disconnected */ }
+    c.stop();
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+tap.test('setup: start throttled VPN tunnel (1 MB/s)', async () => {
+  serverPort = await findFreePort();
+  proxyPort = await findFreePort();
+
+  // Start VPN server
+  server = new VpnServer({ transport: { transport: 'stdio' } });
+  const started = await server['bridge'].start();
+  expect(started).toBeTrue();
+
+  keypair = await server.generateKeypair();
+  const serverConfig: IVpnServerConfig = {
+    listenAddr: `127.0.0.1:${serverPort}`,
+    privateKey: keypair.privateKey,
+    publicKey: keypair.publicKey,
+    subnet: '10.8.0.0/24',
+  };
+  await server['bridge'].sendCommand('start', { config: serverConfig });
+
+  const status = await server.getStatus();
+  expect(status.state).toEqual('connected');
+
+  // Start throttle proxy: 1 MB/s
+  throttle = await startThrottleProxy(proxyPort, '127.0.0.1', serverPort, 1024 * 1024);
+});
+
+tap.test('throttled connection: handshake succeeds through throttle', async () => {
+  const client = await createConnectedClient(proxyPort);
+
+  const status = await client.getStatus();
+  expect(status.state).toEqual('connected');
+  expect(status.assignedIp).toStartWith('10.8.0.');
+
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length === 1;
+  });
+});
+
+tap.test('sustained keepalive under throttle', async () => {
+  // Wait for at least 1 keepalive cycle (3s interval)
+  await delay(4000);
+
+  const client = allClients[0];
+  const stats = await client.getStatistics();
+  expect(stats.keepalivesSent).toBeGreaterThanOrEqual(1);
+  expect(stats.keepalivesReceived).toBeGreaterThanOrEqual(1);
+
+  // Throttle adds latency — RTT should be measurable
+  const quality = await client.getConnectionQuality();
+  expect(quality.srttMs).toBeGreaterThanOrEqual(0);
+  expect(quality.jitterMs).toBeTypeofNumber();
+});
+
+tap.test('3 concurrent throttled clients', async () => {
+  for (let i = 0; i < 3; i++) {
+    await createConnectedClient(proxyPort);
+  }
+
+  // All 4 clients should be visible
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length === 4;
+  });
+
+  const clients = await server.listClients();
+  expect(clients.length).toEqual(4);
+
+  // Verify all IPs are unique
+  const ips = new Set(clients.map((c) => c.assignedIp));
+  expect(ips.size).toEqual(4);
+});
+
+tap.test('rate limiting combined with network throttle', async () => {
+  const clients = await server.listClients();
+  const targetId = clients[0].clientId;
+
+  // Set rate limit on first client
+  await server.setClientRateLimit(targetId, 500, 500);
+  const telemetry = await server.getClientTelemetry(targetId);
+  expect(telemetry.rateLimitBytesPerSec).toEqual(500);
+  expect(telemetry.burstBytes).toEqual(500);
+
+  // Verify another client has no rate limit
+  const otherTelemetry = await server.getClientTelemetry(clients[1].clientId);
+  expect(otherTelemetry.rateLimitBytesPerSec).toBeNullOrUndefined();
+
+  // Clean up the rate limit
+  await server.removeClientRateLimit(targetId);
+});
+
+tap.test('burst waves: 2 waves of 2 clients', async () => {
+  const initialCount = (await server.listClients()).length;
+
+  for (let wave = 0; wave < 2; wave++) {
+    const waveClients: VpnClient[] = [];
+
+    // Connect 2 clients
+    for (let i = 0; i < 2; i++) {
+      const c = await createConnectedClient(proxyPort);
+      waveClients.push(c);
+    }
+
+    // Verify all connected
+    await waitFor(async () => {
+      const all = await server.listClients();
+      return all.length === initialCount + 2;
+    });
+
+    // Disconnect all wave clients
+    for (const c of waveClients) {
+      await stopClient(c);
+    }
+
+    // Wait for server to detect disconnections
+    await waitFor(async () => {
+      const all = await server.listClients();
+      return all.length === initialCount;
+    }, 15000);
+
+    await delay(500);
+  }
+
+  // Verify total connections accumulated
+  const stats = await server.getStatistics();
+  expect(stats.totalConnections).toBeGreaterThanOrEqual(4 + initialCount);
+
+  // Original clients still connected
+  const remaining = await server.listClients();
+  expect(remaining.length).toEqual(initialCount);
+});
+
+tap.test('aggressive throttle: 10 KB/s', async () => {
+  // Close current throttle proxy and start an aggressive one
+  await throttle.close();
+  const aggressivePort = await findFreePort();
+  throttle = await startThrottleProxy(aggressivePort, '127.0.0.1', serverPort, 10 * 1024);
+
+  // Connect a client through the aggressive throttle
+  const client = await createConnectedClient(aggressivePort);
+  const status = await client.getStatus();
+  expect(status.state).toEqual('connected');
+
+  // Wait for keepalive exchange (might take longer due to throttle)
+  await delay(4000);
+
+  const stats = await client.getStatistics();
+  expect(stats.keepalivesSent).toBeGreaterThanOrEqual(1);
+  expect(stats.keepalivesReceived).toBeGreaterThanOrEqual(1);
+});
+
+tap.test('post-load health: direct connection still works', async () => {
+  // Server should still be healthy after all load tests
+  const serverStatus = await server.getStatus();
+  expect(serverStatus.state).toEqual('connected');
+
+  // Connect one more client directly (no throttle)
+  const directClient = await createConnectedClient(serverPort);
+  const status = await directClient.getStatus();
+  expect(status.state).toEqual('connected');
+
+  await delay(3500);
+
+  const stats = await directClient.getStatistics();
+  expect(stats.keepalivesSent).toBeGreaterThanOrEqual(1);
+});
+
+tap.test('teardown: stop all', async () => {
+  // Stop all clients
+  for (const c of allClients) {
+    await stopClient(c);
+  }
+
+  await delay(500);
+
+  // Close throttle proxy
+  if (throttle) {
+    await throttle.close();
+  }
+
+  // Stop server
+  await server.stopServer();
+  server.stop();
+  await delay(500);
+
+  expect(server.running).toBeFalse();
+});
+
+export default tap.start();

test/test.quic.node.ts

@@ -0,0 +1,258 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import * as net from 'net';
+import * as dgram from 'dgram';
+import { VpnClient, VpnServer } from '../ts/index.js';
+import type { IVpnClientOptions, IVpnServerOptions, IVpnKeypair, IVpnServerConfig, IClientConfigBundle } from '../ts/index.js';
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+async function findFreePort(): Promise<number> {
+  const server = net.createServer();
+  await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve));
+  const port = (server.address() as net.AddressInfo).port;
+  await new Promise<void>((resolve) => server.close(() => resolve()));
+  return port;
+}
+
+async function findFreeUdpPort(): Promise<number> {
+  const sock = dgram.createSocket('udp4');
+  await new Promise<void>((resolve) => sock.bind(0, '127.0.0.1', resolve));
+  const port = (sock.address() as net.AddressInfo).port;
+  await new Promise<void>((resolve) => sock.close(resolve));
+  return port;
+}
+
+function delay(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function waitFor(
+  fn: () => Promise<boolean>,
+  timeoutMs: number = 10000,
+  pollMs: number = 500,
+): Promise<void> {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    if (await fn()) return;
+    await delay(pollMs);
+  }
+  throw new Error(`waitFor timed out after ${timeoutMs}ms`);
+}
+
+// ---------------------------------------------------------------------------
+// Test state
+// ---------------------------------------------------------------------------
+
+let server: VpnServer;
+let wsPort: number;
+let quicPort: number;
+let keypair: IVpnKeypair;
+
+// ---------------------------------------------------------------------------
+// Tests: QUIC-only server + QUIC client
+// ---------------------------------------------------------------------------
+
+tap.test('setup: start VPN server in QUIC mode', async () => {
+  quicPort = await findFreeUdpPort();
+
+  const options: IVpnServerOptions = {
+    transport: { transport: 'stdio' },
+  };
+  server = new VpnServer(options);
+
+  const started = await server['bridge'].start();
+  expect(started).toBeTrue();
+
+  keypair = await server.generateKeypair();
+
+  const serverConfig: IVpnServerConfig = {
+    listenAddr: `127.0.0.1:${quicPort}`,
+    privateKey: keypair.privateKey,
+    publicKey: keypair.publicKey,
+    subnet: '10.9.0.0/24',
+    transportMode: 'quic',
+    keepaliveIntervalSecs: 3,
+  };
+  await server['bridge'].sendCommand('start', { config: serverConfig });
+
+  const status = await server.getStatus();
+  expect(status.state).toEqual('connected');
+});
+
+tap.test('QUIC client connects and gets IP', async () => {
+  const bundle = await server.createClient({ clientId: 'quic-client-1' });
+
+  const options: IVpnClientOptions = {
+    transport: { transport: 'stdio' },
+  };
+  const client = new VpnClient(options);
+  const started = await client.start();
+  expect(started).toBeTrue();
+
+  const result = await client.connect({
+    serverUrl: `127.0.0.1:${quicPort}`,
+    serverPublicKey: keypair.publicKey,
+    clientPrivateKey: bundle.secrets.noisePrivateKey,
+    clientPublicKey: bundle.smartvpnConfig.clientPublicKey,
+    transport: 'quic',
+    keepaliveIntervalSecs: 3,
+  });
+
+  expect(result.assignedIp).toBeTypeofString();
+  expect(result.assignedIp).toStartWith('10.9.0.');
+
+  const clientStatus = await client.getStatus();
+  expect(clientStatus.state).toEqual('connected');
+
+  // Verify server sees the client
+  await waitFor(async () => {
+    const clients = await server.listClients();
+    return clients.length >= 1;
+  });
+
+  await client.stop();
+});
+
+tap.test('teardown: stop QUIC server', async () => {
+  await server.stop();
+  await delay(500);
+});
+
+// ---------------------------------------------------------------------------
+// Tests: dual-mode server (both) + auto client
+// ---------------------------------------------------------------------------
+
+let dualServer: VpnServer;
+let dualWsPort: number;
+let dualQuicPort: number;
+let dualKeypair: IVpnKeypair;
+
+tap.test('setup: start VPN server in both mode', async () => {
+  dualWsPort = await findFreePort();
+  dualQuicPort = await findFreeUdpPort();
+
+  const options: IVpnServerOptions = {
+    transport: { transport: 'stdio' },
+  };
+  dualServer = new VpnServer(options);
+
+  const started = await dualServer['bridge'].start();
+  expect(started).toBeTrue();
+
+  dualKeypair = await dualServer.generateKeypair();
+
+  const serverConfig: IVpnServerConfig = {
+    listenAddr: `127.0.0.1:${dualWsPort}`,
+    privateKey: dualKeypair.privateKey,
+    publicKey: dualKeypair.publicKey,
+    subnet: '10.10.0.0/24',
+    transportMode: 'both',
+    quicListenAddr: `127.0.0.1:${dualQuicPort}`,
+    keepaliveIntervalSecs: 3,
+  };
+  await dualServer['bridge'].sendCommand('start', { config: serverConfig });
+
+  const status = await dualServer.getStatus();
+  expect(status.state).toEqual('connected');
+});
+
+tap.test('auto client connects to dual-mode server (QUIC preferred)', async () => {
+  const options: IVpnClientOptions = {
+    transport: { transport: 'stdio' },
+  };
+  const client = new VpnClient(options);
+  const started = await client.start();
+  expect(started).toBeTrue();
+
+  const bundle = await dualServer.createClient({ clientId: 'dual-auto-client' });
+
+  // "auto" mode (default): tries QUIC first at same host:port, falls back to WS
+  // Since the WS port and QUIC port differ, auto will try QUIC on WS port (fail),
+  // then fall back to WebSocket
+  const result = await client.connect({
+    serverUrl: `ws://127.0.0.1:${dualWsPort}`,
+    serverPublicKey: dualKeypair.publicKey,
+    clientPrivateKey: bundle.secrets.noisePrivateKey,
+    clientPublicKey: bundle.smartvpnConfig.clientPublicKey,
+    // transport defaults to 'auto'
+    keepaliveIntervalSecs: 3,
+  });
+
+  expect(result.assignedIp).toBeTypeofString();
+  expect(result.assignedIp).toStartWith('10.10.0.');
+
+  const clientStatus = await client.getStatus();
+  expect(clientStatus.state).toEqual('connected');
+
+  await waitFor(async () => {
+    const clients = await dualServer.listClients();
+    return clients.length >= 1;
+  });
+
+  await client.stop();
+});
+
+tap.test('explicit QUIC client connects to dual-mode server', async () => {
+  const bundle = await dualServer.createClient({ clientId: 'dual-quic-client' });
+
+  const options: IVpnClientOptions = {
+    transport: { transport: 'stdio' },
+  };
+  const client = new VpnClient(options);
+  const started = await client.start();
+  expect(started).toBeTrue();
+
+  const result = await client.connect({
+    serverUrl: `127.0.0.1:${dualQuicPort}`,
+    serverPublicKey: dualKeypair.publicKey,
+    clientPrivateKey: bundle.secrets.noisePrivateKey,
+    clientPublicKey: bundle.smartvpnConfig.clientPublicKey,
+    transport: 'quic',
+    keepaliveIntervalSecs: 3,
+  });
+
+  expect(result.assignedIp).toBeTypeofString();
+  expect(result.assignedIp).toStartWith('10.10.0.');
+
+  const clientStatus = await client.getStatus();
+  expect(clientStatus.state).toEqual('connected');
+
+  await client.stop();
+});
+
+tap.test('keepalive exchange over QUIC', async () => {
+  const bundle = await dualServer.createClient({ clientId: 'dual-keepalive-client' });
+
+  const options: IVpnClientOptions = {
+    transport: { transport: 'stdio' },
+  };
+  const client = new VpnClient(options);
+  await client.start();
+
+  await client.connect({
+    serverUrl: `127.0.0.1:${dualQuicPort}`,
+    serverPublicKey: dualKeypair.publicKey,
+    clientPrivateKey: bundle.secrets.noisePrivateKey,
+    clientPublicKey: bundle.smartvpnConfig.clientPublicKey,
+    transport: 'quic',
+    keepaliveIntervalSecs: 3,
+  });
+
+  // Wait for keepalive exchange
+  await delay(8000);
+
+  const clientStats = await client.getStatistics();
+  expect(clientStats.keepalivesSent).toBeGreaterThanOrEqual(1);
+  expect(clientStats.keepalivesReceived).toBeGreaterThanOrEqual(1);
+
+  await client.stop();
+});
+
+tap.test('teardown: stop dual-mode server', async () => {
+  await dualServer.stop();
+  await delay(500);
+});
+
+export default tap.start();

test/test.vpnconfig.node.ts

@@ -2,10 +2,17 @@ import { tap, expect } from '@git.zone/tstest/tapbundle';
 import { VpnConfig } from '../ts/index.js';
 import type { IVpnClientConfig, IVpnServerConfig } from '../ts/index.js';
 
+// Valid 32-byte base64 keys for testing
+const TEST_KEY_A = 'YWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWE=';
+const TEST_KEY_B = 'YmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmI=';
+const TEST_KEY_C = 'Y2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2M=';
+
 tap.test('VpnConfig: validate valid client config', async () => {
   const config: IVpnClientConfig = {
     serverUrl: 'wss://vpn.example.com/tunnel',
-    serverPublicKey: 'dGVzdHB1YmxpY2tleQ==',
+    serverPublicKey: TEST_KEY_A,
+    clientPrivateKey: TEST_KEY_B,
+    clientPublicKey: TEST_KEY_C,
     dns: ['1.1.1.1', '8.8.8.8'],
     mtu: 1420,
     keepaliveIntervalSecs: 30,
@@ -16,7 +23,9 @@ tap.test('VpnConfig: validate valid client config', async () => {
 
 tap.test('VpnConfig: reject client config without serverUrl', async () => {
   const config = {
-    serverPublicKey: 'dGVzdHB1YmxpY2tleQ==',
+    serverPublicKey: TEST_KEY_A,
+    clientPrivateKey: TEST_KEY_B,
+    clientPublicKey: TEST_KEY_C,
   } as IVpnClientConfig;
   let threw = false;
   try {
@@ -31,7 +40,9 @@ tap.test('VpnConfig: reject client config without serverUrl', async () => {
 tap.test('VpnConfig: reject client config with invalid serverUrl scheme', async () => {
   const config: IVpnClientConfig = {
     serverUrl: 'http://vpn.example.com/tunnel',
-    serverPublicKey: 'dGVzdHB1YmxpY2tleQ==',
+    serverPublicKey: TEST_KEY_A,
+    clientPrivateKey: TEST_KEY_B,
+    clientPublicKey: TEST_KEY_C,
   };
   let threw = false;
   try {
@@ -43,10 +54,28 @@ tap.test('VpnConfig: reject client config with invalid serverUrl scheme', async
   expect(threw).toBeTrue();
 });
 
+tap.test('VpnConfig: reject client config without clientPrivateKey', async () => {
+  const config = {
+    serverUrl: 'wss://vpn.example.com/tunnel',
+    serverPublicKey: TEST_KEY_A,
+    clientPublicKey: TEST_KEY_C,
+  } as IVpnClientConfig;
+  let threw = false;
+  try {
+    VpnConfig.validateClientConfig(config);
+  } catch (e) {
+    threw = true;
+    expect((e as Error).message).toContain('clientPrivateKey');
+  }
+  expect(threw).toBeTrue();
+});
+
 tap.test('VpnConfig: reject client config with invalid MTU', async () => {
   const config: IVpnClientConfig = {
     serverUrl: 'wss://vpn.example.com/tunnel',
-    serverPublicKey: 'dGVzdHB1YmxpY2tleQ==',
+    serverPublicKey: TEST_KEY_A,
+    clientPrivateKey: TEST_KEY_B,
+    clientPublicKey: TEST_KEY_C,
     mtu: 100,
   };
   let threw = false;
@@ -62,7 +91,9 @@ tap.test('VpnConfig: reject client config with invalid MTU', async () => {
 tap.test('VpnConfig: reject client config with invalid DNS', async () => {
   const config: IVpnClientConfig = {
     serverUrl: 'wss://vpn.example.com/tunnel',
-    serverPublicKey: 'dGVzdHB1YmxpY2tleQ==',
+    serverPublicKey: TEST_KEY_A,
+    clientPrivateKey: TEST_KEY_B,
+    clientPublicKey: TEST_KEY_C,
     dns: ['not-an-ip'],
   };
   let threw = false;
@@ -78,12 +109,15 @@ tap.test('VpnConfig: reject client config with invalid DNS', async () => {
 tap.test('VpnConfig: validate valid server config', async () => {
   const config: IVpnServerConfig = {
     listenAddr: '0.0.0.0:443',
-    privateKey: 'dGVzdHByaXZhdGVrZXk=',
+    privateKey: TEST_KEY_A,
-    publicKey: 'dGVzdHB1YmxpY2tleQ==',
+    publicKey: TEST_KEY_B,
     subnet: '10.8.0.0/24',
     dns: ['1.1.1.1'],
     mtu: 1420,
     enableNat: true,
+    clients: [
+      { clientId: 'test-client', publicKey: TEST_KEY_C },
+    ],
   };
   // Should not throw
   VpnConfig.validateServerConfig(config);
@@ -92,8 +126,8 @@ tap.test('VpnConfig: validate valid server config', async () => {
 tap.test('VpnConfig: reject server config with invalid subnet', async () => {
   const config: IVpnServerConfig = {
     listenAddr: '0.0.0.0:443',
-    privateKey: 'dGVzdHByaXZhdGVrZXk=',
+    privateKey: TEST_KEY_A,
-    publicKey: 'dGVzdHB1YmxpY2tleQ==',
+    publicKey: TEST_KEY_B,
     subnet: 'invalid',
   };
   let threw = false;
@@ -109,7 +143,7 @@ tap.test('VpnConfig: reject server config with invalid subnet', async () => {
 tap.test('VpnConfig: reject server config without privateKey', async () => {
   const config = {
     listenAddr: '0.0.0.0:443',
-    publicKey: 'dGVzdHB1YmxpY2tleQ==',
+    publicKey: TEST_KEY_B,
     subnet: '10.8.0.0/24',
   } as IVpnServerConfig;
   let threw = false;
@@ -122,4 +156,24 @@ tap.test('VpnConfig: reject server config without privateKey', async () => {
   expect(threw).toBeTrue();
 });
 
+tap.test('VpnConfig: reject server config with invalid client publicKey', async () => {
+  const config: IVpnServerConfig = {
+    listenAddr: '0.0.0.0:443',
+    privateKey: TEST_KEY_A,
+    publicKey: TEST_KEY_B,
+    subnet: '10.8.0.0/24',
+    clients: [
+      { clientId: 'bad-client', publicKey: 'short-key' },
+    ],
+  };
+  let threw = false;
+  try {
+    VpnConfig.validateServerConfig(config);
+  } catch (e) {
+    threw = true;
+    expect((e as Error).message).toContain('publicKey');
+  }
+  expect(threw).toBeTrue();
+});
+
 export default tap.start();

test/test.wireguard.node.ts

@@ -0,0 +1,353 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import {
+  VpnConfig,
+  VpnServer,
+  WgConfigGenerator,
+} from '../ts/index.js';
+import type {
+  IVpnClientConfig,
+  IVpnServerConfig,
+  IVpnServerOptions,
+  IWgPeerConfig,
+} from '../ts/index.js';
+
+// ============================================================================
+// WireGuard config validation — client
+// ============================================================================
+
+// A valid 32-byte key in base64 (44 chars)
+const VALID_KEY = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=';
+const VALID_KEY_2 = 'BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB=';
+
+tap.test('WG client config: valid wireguard config passes validation', async () => {
+  const config: IVpnClientConfig = {
+    serverUrl: '', // not needed for WG
+    serverPublicKey: VALID_KEY,
+    transport: 'wireguard',
+    wgPrivateKey: VALID_KEY_2,
+    wgAddress: '10.8.0.2',
+    wgEndpoint: 'vpn.example.com:51820',
+    wgAllowedIps: ['0.0.0.0/0'],
+  };
+  VpnConfig.validateClientConfig(config);
+});
+
+tap.test('WG client config: rejects missing wgPrivateKey', async () => {
+  const config: IVpnClientConfig = {
+    serverUrl: '',
+    serverPublicKey: VALID_KEY,
+    transport: 'wireguard',
+    wgAddress: '10.8.0.2',
+    wgEndpoint: 'vpn.example.com:51820',
+  };
+  let threw = false;
+  try {
+    VpnConfig.validateClientConfig(config);
+  } catch (e) {
+    threw = true;
+    expect((e as Error).message).toContain('wgPrivateKey');
+  }
+  expect(threw).toBeTrue();
+});
+
+tap.test('WG client config: rejects missing wgAddress', async () => {
+  const config: IVpnClientConfig = {
+    serverUrl: '',
+    serverPublicKey: VALID_KEY,
+    transport: 'wireguard',
+    wgPrivateKey: VALID_KEY_2,
+    wgEndpoint: 'vpn.example.com:51820',
+  };
+  let threw = false;
+  try {
+    VpnConfig.validateClientConfig(config);
+  } catch (e) {
+    threw = true;
+    expect((e as Error).message).toContain('wgAddress');
+  }
+  expect(threw).toBeTrue();
+});
+
+tap.test('WG client config: rejects missing wgEndpoint', async () => {
+  const config: IVpnClientConfig = {
+    serverUrl: '',
+    serverPublicKey: VALID_KEY,
+    transport: 'wireguard',
+    wgPrivateKey: VALID_KEY_2,
+    wgAddress: '10.8.0.2',
+  };
+  let threw = false;
+  try {
+    VpnConfig.validateClientConfig(config);
+  } catch (e) {
+    threw = true;
+    expect((e as Error).message).toContain('wgEndpoint');
+  }
+  expect(threw).toBeTrue();
+});
+
+tap.test('WG client config: rejects invalid key length', async () => {
+  const config: IVpnClientConfig = {
+    serverUrl: '',
+    serverPublicKey: VALID_KEY,
+    transport: 'wireguard',
+    wgPrivateKey: 'tooshort',
+    wgAddress: '10.8.0.2',
+    wgEndpoint: 'vpn.example.com:51820',
+  };
+  let threw = false;
+  try {
+    VpnConfig.validateClientConfig(config);
+  } catch (e) {
+    threw = true;
+    expect((e as Error).message).toContain('44 characters');
+  }
+  expect(threw).toBeTrue();
+});
+
+tap.test('WG client config: rejects invalid CIDR in allowedIps', async () => {
+  const config: IVpnClientConfig = {
+    serverUrl: '',
+    serverPublicKey: VALID_KEY,
+    transport: 'wireguard',
+    wgPrivateKey: VALID_KEY_2,
+    wgAddress: '10.8.0.2',
+    wgEndpoint: 'vpn.example.com:51820',
+    wgAllowedIps: ['not-a-cidr'],
+  };
+  let threw = false;
+  try {
+    VpnConfig.validateClientConfig(config);
+  } catch (e) {
+    threw = true;
+    expect((e as Error).message).toContain('CIDR');
+  }
+  expect(threw).toBeTrue();
+});
+
+// ============================================================================
+// WireGuard config validation — server
+// ============================================================================
+
+tap.test('WG server config: valid config passes validation', async () => {
+  const config: IVpnServerConfig = {
+    listenAddr: '',
+    privateKey: VALID_KEY,
+    publicKey: VALID_KEY_2,
+    subnet: '10.8.0.0/24',
+    transportMode: 'wireguard',
+    wgPeers: [
+      {
+        publicKey: VALID_KEY_2,
+        allowedIps: ['10.8.0.2/32'],
+      },
+    ],
+  };
+  VpnConfig.validateServerConfig(config);
+});
+
+tap.test('WG server config: rejects empty wgPeers', async () => {
+  const config: IVpnServerConfig = {
+    listenAddr: '',
+    privateKey: VALID_KEY,
+    publicKey: VALID_KEY_2,
+    subnet: '10.8.0.0/24',
+    transportMode: 'wireguard',
+    wgPeers: [],
+  };
+  let threw = false;
+  try {
+    VpnConfig.validateServerConfig(config);
+  } catch (e) {
+    threw = true;
+    expect((e as Error).message).toContain('wgPeers');
+  }
+  expect(threw).toBeTrue();
+});
+
+tap.test('WG server config: rejects peer without publicKey', async () => {
+  const config: IVpnServerConfig = {
+    listenAddr: '',
+    privateKey: VALID_KEY,
+    publicKey: VALID_KEY_2,
+    subnet: '10.8.0.0/24',
+    transportMode: 'wireguard',
+    wgPeers: [
+      {
+        publicKey: '',
+        allowedIps: ['10.8.0.2/32'],
+      },
+    ],
+  };
+  let threw = false;
+  try {
+    VpnConfig.validateServerConfig(config);
+  } catch (e) {
+    threw = true;
+    expect((e as Error).message).toContain('publicKey');
+  }
+  expect(threw).toBeTrue();
+});
+
+tap.test('WG server config: rejects invalid wgListenPort', async () => {
+  const config: IVpnServerConfig = {
+    listenAddr: '',
+    privateKey: VALID_KEY,
+    publicKey: VALID_KEY_2,
+    subnet: '10.8.0.0/24',
+    transportMode: 'wireguard',
+    wgListenPort: 0,
+    wgPeers: [
+      {
+        publicKey: VALID_KEY_2,
+        allowedIps: ['10.8.0.2/32'],
+      },
+    ],
+  };
+  let threw = false;
+  try {
+    VpnConfig.validateServerConfig(config);
+  } catch (e) {
+    threw = true;
+    expect((e as Error).message).toContain('wgListenPort');
+  }
+  expect(threw).toBeTrue();
+});
+
+// ============================================================================
+// WireGuard keypair generation via daemon
+// ============================================================================
+
+let server: VpnServer;
+
+tap.test('WG: spawn server daemon for keypair generation', async () => {
+  const options: IVpnServerOptions = {
+    transport: { transport: 'stdio' },
+  };
+  server = new VpnServer(options);
+  const started = await server['bridge'].start();
+  expect(started).toBeTrue();
+  expect(server.running).toBeTrue();
+});
+
+tap.test('WG: generateWgKeypair returns valid keypair', async () => {
+  const keypair = await server.generateWgKeypair();
+  expect(keypair.publicKey).toBeTypeofString();
+  expect(keypair.privateKey).toBeTypeofString();
+  // WireGuard keys: base64 of 32 bytes = 44 characters
+  expect(keypair.publicKey.length).toEqual(44);
+  expect(keypair.privateKey.length).toEqual(44);
+  // Verify they decode to 32 bytes
+  const pubBuf = Buffer.from(keypair.publicKey, 'base64');
+  const privBuf = Buffer.from(keypair.privateKey, 'base64');
+  expect(pubBuf.length).toEqual(32);
+  expect(privBuf.length).toEqual(32);
+});
+
+tap.test('WG: generateWgKeypair returns unique keys each time', async () => {
+  const kp1 = await server.generateWgKeypair();
+  const kp2 = await server.generateWgKeypair();
+  expect(kp1.publicKey).not.toEqual(kp2.publicKey);
+  expect(kp1.privateKey).not.toEqual(kp2.privateKey);
+});
+
+tap.test('WG: stop server daemon', async () => {
+  server.stop();
+  await new Promise((resolve) => setTimeout(resolve, 500));
+  expect(server.running).toBeFalse();
+});
+
+// ============================================================================
+// WireGuard config file generation
+// ============================================================================
+
+tap.test('WgConfigGenerator: generate client config', async () => {
+  const conf = WgConfigGenerator.generateClientConfig({
+    privateKey: 'clientPrivateKeyBase64====================',
+    address: '10.8.0.2/24',
+    dns: ['1.1.1.1', '8.8.8.8'],
+    mtu: 1420,
+    peer: {
+      publicKey: 'serverPublicKeyBase64====================',
+      endpoint: 'vpn.example.com:51820',
+      allowedIps: ['0.0.0.0/0', '::/0'],
+      persistentKeepalive: 25,
+    },
+  });
+  expect(conf).toContain('[Interface]');
+  expect(conf).toContain('PrivateKey = clientPrivateKeyBase64====================');
+  expect(conf).toContain('Address = 10.8.0.2/24');
+  expect(conf).toContain('DNS = 1.1.1.1, 8.8.8.8');
+  expect(conf).toContain('MTU = 1420');
+  expect(conf).toContain('[Peer]');
+  expect(conf).toContain('PublicKey = serverPublicKeyBase64====================');
+  expect(conf).toContain('Endpoint = vpn.example.com:51820');
+  expect(conf).toContain('AllowedIPs = 0.0.0.0/0, ::/0');
+  expect(conf).toContain('PersistentKeepalive = 25');
+});
+
+tap.test('WgConfigGenerator: generate client config without optional fields', async () => {
+  const conf = WgConfigGenerator.generateClientConfig({
+    privateKey: 'key1',
+    address: '10.0.0.2/32',
+    peer: {
+      publicKey: 'key2',
+      endpoint: 'server:51820',
+      allowedIps: ['10.0.0.0/24'],
+    },
+  });
+  expect(conf).toContain('[Interface]');
+  expect(conf).not.toContain('DNS');
+  expect(conf).not.toContain('MTU');
+  expect(conf).not.toContain('PresharedKey');
+  expect(conf).not.toContain('PersistentKeepalive');
+});
+
+tap.test('WgConfigGenerator: generate server config with NAT', async () => {
+  const conf = WgConfigGenerator.generateServerConfig({
+    privateKey: 'serverPrivKey',
+    address: '10.8.0.1/24',
+    listenPort: 51820,
+    dns: ['1.1.1.1'],
+    enableNat: true,
+    natInterface: 'ens3',
+    peers: [
+      {
+        publicKey: 'peer1PubKey',
+        allowedIps: ['10.8.0.2/32'],
+        presharedKey: 'psk1',
+        persistentKeepalive: 25,
+      },
+      {
+        publicKey: 'peer2PubKey',
+        allowedIps: ['10.8.0.3/32'],
+      },
+    ],
+  });
+  expect(conf).toContain('[Interface]');
+  expect(conf).toContain('ListenPort = 51820');
+  expect(conf).toContain('PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -t nat -A POSTROUTING -o ens3 -j MASQUERADE');
+  expect(conf).toContain('PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -t nat -D POSTROUTING -o ens3 -j MASQUERADE');
+  // Two [Peer] sections
+  const peerCount = (conf.match(/\[Peer\]/g) || []).length;
+  expect(peerCount).toEqual(2);
+  expect(conf).toContain('PresharedKey = psk1');
+});
+
+tap.test('WgConfigGenerator: generate server config without NAT', async () => {
+  const conf = WgConfigGenerator.generateServerConfig({
+    privateKey: 'serverPrivKey',
+    address: '10.8.0.1/24',
+    listenPort: 51820,
+    peers: [
+      {
+        publicKey: 'peerKey',
+        allowedIps: ['10.8.0.2/32'],
+      },
+    ],
+  });
+  expect(conf).not.toContain('PostUp');
+  expect(conf).not.toContain('PostDown');
+});
+
+export default tap.start();

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartvpn',
-  version: '1.0.3',
+  version: '1.10.1',
   description: 'A VPN solution with TypeScript control plane and Rust data plane daemon'
 }

ts/index.ts

@@ -4,3 +4,4 @@ export { VpnClient } from './smartvpn.classes.vpnclient.js';
 export { VpnServer } from './smartvpn.classes.vpnserver.js';
 export { VpnConfig } from './smartvpn.classes.vpnconfig.js';
 export { VpnInstaller } from './smartvpn.classes.vpninstaller.js';
+export { WgConfigGenerator } from './smartvpn.classes.wgconfig.js';

ts/smartvpn.classes.vpnclient.ts

@@ -5,6 +5,8 @@ import type {
   IVpnClientConfig,
   IVpnStatus,
   IVpnStatistics,
+  IVpnConnectionQuality,
+  IVpnMtuInfo,
   TVpnClientCommands,
 } from './smartvpn.interfaces.js';
 
@@ -65,12 +67,26 @@ export class VpnClient extends plugins.events.EventEmitter {
   }
 
   /**
-   * Get traffic statistics.
+   * Get traffic statistics (includes connection quality when connected).
    */
   public async getStatistics(): Promise<IVpnStatistics> {
     return this.bridge.sendCommand('getStatistics', {} as Record<string, never>);
   }
 
+  /**
+   * Get connection quality metrics (RTT, jitter, loss, link health).
+   */
+  public async getConnectionQuality(): Promise<IVpnConnectionQuality> {
+    return this.bridge.sendCommand('getConnectionQuality', {} as Record<string, never>);
+  }
+
+  /**
+   * Get MTU information (overhead, effective MTU, oversized packet stats).
+   */
+  public async getMtuInfo(): Promise<IVpnMtuInfo> {
+    return this.bridge.sendCommand('getMtuInfo', {} as Record<string, never>);
+  }
+
   /**
    * Stop the daemon bridge.
    */

ts/smartvpn.classes.vpnconfig.ts

@@ -12,14 +12,54 @@ export class VpnConfig {
    * Validate a client config object. Throws on invalid config.
    */
   public static validateClientConfig(config: IVpnClientConfig): void {
-    if (!config.serverUrl) {
+    if (config.transport === 'wireguard') {
-      throw new Error('VpnConfig: serverUrl is required');
+      // WireGuard-specific validation
-    }
+      if (!config.wgPrivateKey) {
-    if (!config.serverUrl.startsWith('wss://') && !config.serverUrl.startsWith('ws://')) {
+        throw new Error('VpnConfig: wgPrivateKey is required for WireGuard transport');
-      throw new Error('VpnConfig: serverUrl must start with wss:// or ws://');
+      }
-    }
+      VpnConfig.validateBase64Key(config.wgPrivateKey, 'wgPrivateKey');
-    if (!config.serverPublicKey) {
+      if (!config.wgAddress) {
-      throw new Error('VpnConfig: serverPublicKey is required');
+        throw new Error('VpnConfig: wgAddress is required for WireGuard transport');
+      }
+      if (!config.serverPublicKey) {
+        throw new Error('VpnConfig: serverPublicKey is required for WireGuard transport');
+      }
+      VpnConfig.validateBase64Key(config.serverPublicKey, 'serverPublicKey');
+      if (!config.wgEndpoint) {
+        throw new Error('VpnConfig: wgEndpoint is required for WireGuard transport');
+      }
+      if (config.wgPresharedKey) {
+        VpnConfig.validateBase64Key(config.wgPresharedKey, 'wgPresharedKey');
+      }
+      if (config.wgAllowedIps) {
+        for (const cidr of config.wgAllowedIps) {
+          if (!VpnConfig.isValidCidr(cidr)) {
+            throw new Error(`VpnConfig: invalid allowedIp CIDR: ${cidr}`);
+          }
+        }
+      }
+    } else {
+      if (!config.serverUrl) {
+        throw new Error('VpnConfig: serverUrl is required');
+      }
+      // For QUIC-only transport, serverUrl is a host:port address; for WebSocket/auto it must be ws:// or wss://
+      if (config.transport !== 'quic') {
+        if (!config.serverUrl.startsWith('wss://') && !config.serverUrl.startsWith('ws://')) {
+          throw new Error('VpnConfig: serverUrl must start with wss:// or ws:// (for WebSocket transport)');
+        }
+      }
+      if (!config.serverPublicKey) {
+        throw new Error('VpnConfig: serverPublicKey is required');
+      }
+      // Noise IK requires client keypair
+      if (!config.clientPrivateKey) {
+        throw new Error('VpnConfig: clientPrivateKey is required for Noise IK authentication');
+      }
+      VpnConfig.validateBase64Key(config.clientPrivateKey, 'clientPrivateKey');
+      if (!config.clientPublicKey) {
+        throw new Error('VpnConfig: clientPublicKey is required for Noise IK authentication');
+      }
+      VpnConfig.validateBase64Key(config.clientPublicKey, 'clientPublicKey');
     }
     if (config.mtu !== undefined && (config.mtu < 576 || config.mtu > 65535)) {
       throw new Error('VpnConfig: mtu must be between 576 and 65535');
@@ -40,20 +80,63 @@ export class VpnConfig {
    * Validate a server config object. Throws on invalid config.
    */
   public static validateServerConfig(config: IVpnServerConfig): void {
-    if (!config.listenAddr) {
+    if (config.transportMode === 'wireguard') {
-      throw new Error('VpnConfig: listenAddr is required');
+      // WireGuard server validation
-    }
+      if (!config.privateKey) {
-    if (!config.privateKey) {
+        throw new Error('VpnConfig: privateKey is required');
-      throw new Error('VpnConfig: privateKey is required');
+      }
-    }
+      VpnConfig.validateBase64Key(config.privateKey, 'privateKey');
-    if (!config.publicKey) {
+      if (!config.wgPeers || config.wgPeers.length === 0) {
-      throw new Error('VpnConfig: publicKey is required');
+        throw new Error('VpnConfig: at least one wgPeers entry is required for WireGuard mode');
-    }
+      }
-    if (!config.subnet) {
+      for (const peer of config.wgPeers) {
-      throw new Error('VpnConfig: subnet is required');
+        if (!peer.publicKey) {
-    }
+          throw new Error('VpnConfig: peer publicKey is required');
-    if (!VpnConfig.isValidSubnet(config.subnet)) {
+        }
-      throw new Error(`VpnConfig: invalid subnet: ${config.subnet}`);
+        VpnConfig.validateBase64Key(peer.publicKey, 'peer.publicKey');
+        if (!peer.allowedIps || peer.allowedIps.length === 0) {
+          throw new Error('VpnConfig: peer allowedIps is required');
+        }
+        for (const cidr of peer.allowedIps) {
+          if (!VpnConfig.isValidCidr(cidr)) {
+            throw new Error(`VpnConfig: invalid peer allowedIp CIDR: ${cidr}`);
+          }
+        }
+        if (peer.presharedKey) {
+          VpnConfig.validateBase64Key(peer.presharedKey, 'peer.presharedKey');
+        }
+      }
+      if (config.wgListenPort !== undefined && (config.wgListenPort < 1 || config.wgListenPort > 65535)) {
+        throw new Error('VpnConfig: wgListenPort must be between 1 and 65535');
+      }
+    } else {
+      if (!config.listenAddr) {
+        throw new Error('VpnConfig: listenAddr is required');
+      }
+      if (!config.privateKey) {
+        throw new Error('VpnConfig: privateKey is required');
+      }
+      if (!config.publicKey) {
+        throw new Error('VpnConfig: publicKey is required');
+      }
+      if (!config.subnet) {
+        throw new Error('VpnConfig: subnet is required');
+      }
+      if (!VpnConfig.isValidSubnet(config.subnet)) {
+        throw new Error(`VpnConfig: invalid subnet: ${config.subnet}`);
+      }
+      // Validate client entries if provided
+      if (config.clients) {
+        for (const client of config.clients) {
+          if (!client.clientId) {
+            throw new Error('VpnConfig: client entry must have a clientId');
+          }
+          if (!client.publicKey) {
+            throw new Error(`VpnConfig: client '${client.clientId}' must have a publicKey`);
+          }
+          VpnConfig.validateBase64Key(client.publicKey, `client '${client.clientId}' publicKey`);
+        }
+      }
     }
     if (config.mtu !== undefined && (config.mtu < 576 || config.mtu > 65535)) {
       throw new Error('VpnConfig: mtu must be between 576 and 65535');
@@ -101,4 +184,41 @@ export class VpnConfig {
     const prefixNum = parseInt(prefix, 10);
     return !isNaN(prefixNum) && prefixNum >= 0 && prefixNum <= 32;
   }
+
+  /**
+   * Validate a CIDR string (IPv4 or IPv6).
+   */
+  private static isValidCidr(cidr: string): boolean {
+    const parts = cidr.split('/');
+    if (parts.length !== 2) return false;
+    const prefixNum = parseInt(parts[1], 10);
+    if (isNaN(prefixNum) || prefixNum < 0) return false;
+    // IPv4
+    if (VpnConfig.isValidIp(parts[0])) {
+      return prefixNum <= 32;
+    }
+    // IPv6 (basic check)
+    if (parts[0].includes(':')) {
+      return prefixNum <= 128;
+    }
+    return false;
+  }
+
+  /**
+   * Validate a base64-encoded 32-byte key (WireGuard X25519 format).
+   */
+  private static validateBase64Key(key: string, fieldName: string): void {
+    if (key.length !== 44) {
+      throw new Error(`VpnConfig: ${fieldName} must be 44 characters (base64 of 32 bytes), got ${key.length}`);
+    }
+    try {
+      const buf = Buffer.from(key, 'base64');
+      if (buf.length !== 32) {
+        throw new Error(`VpnConfig: ${fieldName} must decode to 32 bytes, got ${buf.length}`);
+      }
+    } catch (e) {
+      if (e instanceof Error && e.message.startsWith('VpnConfig:')) throw e;
+      throw new Error(`VpnConfig: ${fieldName} is not valid base64`);
+    }
+  }
 }

ts/smartvpn.classes.vpnserver.ts

@@ -7,6 +7,11 @@ import type {
   IVpnServerStatistics,
   IVpnClientInfo,
   IVpnKeypair,
+  IVpnClientTelemetry,
+  IWgPeerConfig,
+  IWgPeerInfo,
+  IClientEntry,
+  IClientConfigBundle,
   TVpnServerCommands,
 } from './smartvpn.interfaces.js';
 
@@ -91,6 +96,139 @@ export class VpnServer extends plugins.events.EventEmitter {
     return this.bridge.sendCommand('generateKeypair', {} as Record<string, never>);
   }
 
+  /**
+   * Set rate limit for a specific client.
+   */
+  public async setClientRateLimit(
+    clientId: string,
+    rateBytesPerSec: number,
+    burstBytes: number,
+  ): Promise<void> {
+    await this.bridge.sendCommand('setClientRateLimit', {
+      clientId,
+      rateBytesPerSec,
+      burstBytes,
+    });
+  }
+
+  /**
+   * Remove rate limit for a specific client (unlimited).
+   */
+  public async removeClientRateLimit(clientId: string): Promise<void> {
+    await this.bridge.sendCommand('removeClientRateLimit', { clientId });
+  }
+
+  /**
+   * Get telemetry for a specific client.
+   */
+  public async getClientTelemetry(clientId: string): Promise<IVpnClientTelemetry> {
+    return this.bridge.sendCommand('getClientTelemetry', { clientId });
+  }
+
+  /**
+   * Generate a WireGuard-compatible X25519 keypair.
+   */
+  public async generateWgKeypair(): Promise<IVpnKeypair> {
+    return this.bridge.sendCommand('generateWgKeypair', {} as Record<string, never>);
+  }
+
+  /**
+   * Add a WireGuard peer (server must be running in wireguard mode).
+   */
+  public async addWgPeer(peer: IWgPeerConfig): Promise<void> {
+    await this.bridge.sendCommand('addWgPeer', { peer });
+  }
+
+  /**
+   * Remove a WireGuard peer by public key.
+   */
+  public async removeWgPeer(publicKey: string): Promise<void> {
+    await this.bridge.sendCommand('removeWgPeer', { publicKey });
+  }
+
+  /**
+   * List WireGuard peers with stats.
+   */
+  public async listWgPeers(): Promise<IWgPeerInfo[]> {
+    const result = await this.bridge.sendCommand('listWgPeers', {} as Record<string, never>);
+    return result.peers;
+  }
+
+  // ── Client Registry (Hub) Methods ─────────────────────────────────────
+
+  /**
+   * Create a new client. Generates keypairs, assigns IP, returns full config bundle.
+   * The secrets (private keys) are only returned at creation time.
+   */
+  public async createClient(opts: Partial<IClientEntry>): Promise<IClientConfigBundle> {
+    return this.bridge.sendCommand('createClient', { client: opts });
+  }
+
+  /**
+   * Remove a registered client (also disconnects if connected).
+   */
+  public async removeClient(clientId: string): Promise<void> {
+    await this.bridge.sendCommand('removeClient', { clientId });
+  }
+
+  /**
+   * Get a registered client by ID.
+   */
+  public async getClient(clientId: string): Promise<IClientEntry> {
+    return this.bridge.sendCommand('getClient', { clientId });
+  }
+
+  /**
+   * List all registered clients.
+   */
+  public async listRegisteredClients(): Promise<IClientEntry[]> {
+    const result = await this.bridge.sendCommand('listRegisteredClients', {} as Record<string, never>);
+    return result.clients;
+  }
+
+  /**
+   * Update a registered client's fields (ACLs, tags, description, etc.).
+   */
+  public async updateClient(clientId: string, update: Partial<IClientEntry>): Promise<void> {
+    await this.bridge.sendCommand('updateClient', { clientId, update });
+  }
+
+  /**
+   * Enable a previously disabled client.
+   */
+  public async enableClient(clientId: string): Promise<void> {
+    await this.bridge.sendCommand('enableClient', { clientId });
+  }
+
+  /**
+   * Disable a client (also disconnects if connected).
+   */
+  public async disableClient(clientId: string): Promise<void> {
+    await this.bridge.sendCommand('disableClient', { clientId });
+  }
+
+  /**
+   * Rotate a client's keys. Returns a new config bundle with fresh keypairs.
+   */
+  public async rotateClientKey(clientId: string): Promise<IClientConfigBundle> {
+    return this.bridge.sendCommand('rotateClientKey', { clientId });
+  }
+
+  /**
+   * Export a client config (without secrets) in the specified format.
+   */
+  public async exportClientConfig(clientId: string, format: 'smartvpn' | 'wireguard'): Promise<string> {
+    const result = await this.bridge.sendCommand('exportClientConfig', { clientId, format });
+    return result.config;
+  }
+
+  /**
+   * Generate a standalone Noise IK keypair (not tied to a client).
+   */
+  public async generateClientKeypair(): Promise<IVpnKeypair> {
+    return this.bridge.sendCommand('generateClientKeypair', {} as Record<string, never>);
+  }
+
   /**
    * Stop the daemon bridge.
    */

ts/smartvpn.classes.wgconfig.ts

@@ -0,0 +1,123 @@
+import type { IWgPeerConfig } from './smartvpn.interfaces.js';
+
+// ============================================================================
+// WireGuard .conf file generator
+// ============================================================================
+
+export interface IWgClientConfOptions {
+  /** Client private key (base64) */
+  privateKey: string;
+  /** Client TUN address with prefix (e.g. 10.8.0.2/24) */
+  address: string;
+  /** DNS servers */
+  dns?: string[];
+  /** TUN MTU */
+  mtu?: number;
+  /** Server peer config */
+  peer: {
+    publicKey: string;
+    presharedKey?: string;
+    endpoint: string;
+    allowedIps: string[];
+    persistentKeepalive?: number;
+  };
+}
+
+export interface IWgServerConfOptions {
+  /** Server private key (base64) */
+  privateKey: string;
+  /** Server TUN address with prefix (e.g. 10.8.0.1/24) */
+  address: string;
+  /** UDP listen port */
+  listenPort: number;
+  /** DNS servers */
+  dns?: string[];
+  /** TUN MTU */
+  mtu?: number;
+  /** Enable NAT — adds PostUp/PostDown iptables rules */
+  enableNat?: boolean;
+  /** Network interface for NAT (e.g. eth0). Auto-detected if omitted. */
+  natInterface?: string;
+  /** Configured peers */
+  peers: IWgPeerConfig[];
+}
+
+/**
+ * Generates standard WireGuard .conf files compatible with wg-quick,
+ * WireGuard iOS/Android apps, and other standard WireGuard clients.
+ */
+export class WgConfigGenerator {
+  /**
+   * Generate a client .conf file content.
+   */
+  public static generateClientConfig(opts: IWgClientConfOptions): string {
+    const lines: string[] = [];
+
+    lines.push('[Interface]');
+    lines.push(`PrivateKey = ${opts.privateKey}`);
+    lines.push(`Address = ${opts.address}`);
+    if (opts.dns && opts.dns.length > 0) {
+      lines.push(`DNS = ${opts.dns.join(', ')}`);
+    }
+    if (opts.mtu) {
+      lines.push(`MTU = ${opts.mtu}`);
+    }
+
+    lines.push('');
+    lines.push('[Peer]');
+    lines.push(`PublicKey = ${opts.peer.publicKey}`);
+    if (opts.peer.presharedKey) {
+      lines.push(`PresharedKey = ${opts.peer.presharedKey}`);
+    }
+    lines.push(`Endpoint = ${opts.peer.endpoint}`);
+    lines.push(`AllowedIPs = ${opts.peer.allowedIps.join(', ')}`);
+    if (opts.peer.persistentKeepalive) {
+      lines.push(`PersistentKeepalive = ${opts.peer.persistentKeepalive}`);
+    }
+
+    lines.push('');
+    return lines.join('\n');
+  }
+
+  /**
+   * Generate a server .conf file content.
+   */
+  public static generateServerConfig(opts: IWgServerConfOptions): string {
+    const lines: string[] = [];
+
+    lines.push('[Interface]');
+    lines.push(`PrivateKey = ${opts.privateKey}`);
+    lines.push(`Address = ${opts.address}`);
+    lines.push(`ListenPort = ${opts.listenPort}`);
+    if (opts.dns && opts.dns.length > 0) {
+      lines.push(`DNS = ${opts.dns.join(', ')}`);
+    }
+    if (opts.mtu) {
+      lines.push(`MTU = ${opts.mtu}`);
+    }
+    if (opts.enableNat) {
+      const iface = opts.natInterface || 'eth0';
+      lines.push(`PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -t nat -A POSTROUTING -o ${iface} -j MASQUERADE`);
+      lines.push(`PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -t nat -D POSTROUTING -o ${iface} -j MASQUERADE`);
+    }
+
+    for (const peer of opts.peers) {
+      lines.push('');
+      lines.push('[Peer]');
+      lines.push(`PublicKey = ${peer.publicKey}`);
+      if (peer.presharedKey) {
+        lines.push(`PresharedKey = ${peer.presharedKey}`);
+      }
+      lines.push(`AllowedIPs = ${peer.allowedIps.join(', ')}`);
+      if (peer.endpoint) {
+        lines.push(`Endpoint = ${peer.endpoint}`);
+      }
+      if (peer.persistentKeepalive) {
+        lines.push(`PersistentKeepalive = ${peer.persistentKeepalive}`);
+      }
+    }
+
+    lines.push('');
+    return lines.join('\n');
+  }
+}

ts/smartvpn.interfaces.ts

@@ -24,14 +24,39 @@ export type TVpnTransportOptions = IVpnTransportStdio | IVpnTransportSocket;
 export interface IVpnClientConfig {
   /** Server WebSocket URL, e.g. wss://vpn.example.com/tunnel */
   serverUrl: string;
-  /** Server's static public key (base64) for Noise NK handshake */
+  /** Server's static public key (base64) for Noise IK handshake */
   serverPublicKey: string;
+  /** Client's Noise IK private key (base64) — required for SmartVPN native transport */
+  clientPrivateKey: string;
+  /** Client's Noise IK public key (base64) — for reference/display */
+  clientPublicKey: string;
   /** Optional DNS servers to use while connected */
   dns?: string[];
   /** Optional MTU for the TUN device */
   mtu?: number;
   /** Keepalive interval in seconds (default: 30) */
   keepaliveIntervalSecs?: number;
+  /** Transport protocol: 'auto' (default, tries QUIC then WS), 'websocket', 'quic', or 'wireguard' */
+  transport?: 'auto' | 'websocket' | 'quic' | 'wireguard';
+  /** For QUIC: SHA-256 hash of server certificate (base64) for cert pinning */
+  serverCertHash?: string;
+  /** Forwarding mode: 'tun' (TUN device, requires root) or 'testing' (no TUN).
+   *  Default: 'testing'. */
+  forwardingMode?: 'tun' | 'testing';
+  /** WireGuard: client private key (base64, X25519) */
+  wgPrivateKey?: string;
+  /** WireGuard: client TUN address (e.g. 10.8.0.2) */
+  wgAddress?: string;
+  /** WireGuard: client TUN address prefix length (default: 24) */
+  wgAddressPrefix?: number;
+  /** WireGuard: preshared key (base64, optional) */
+  wgPresharedKey?: string;
+  /** WireGuard: persistent keepalive interval in seconds */
+  wgPersistentKeepalive?: number;
+  /** WireGuard: server endpoint (host:port, e.g. vpn.example.com:51820) */
+  wgEndpoint?: string;
+  /** WireGuard: allowed IPs (CIDR strings, e.g. ['0.0.0.0/0']) */
+  wgAllowedIps?: string[];
 }
 
 export interface IVpnClientOptions {
@@ -64,6 +89,32 @@ export interface IVpnServerConfig {
   keepaliveIntervalSecs?: number;
   /** Enable NAT/masquerade for client traffic */
   enableNat?: boolean;
+  /** Forwarding mode: 'tun' (kernel TUN, requires root), 'socket' (userspace NAT),
+   *  or 'testing' (monitoring only). Default: 'testing'. */
+  forwardingMode?: 'tun' | 'socket' | 'testing';
+  /** Default rate limit for new clients (bytes/sec). Omit for unlimited. */
+  defaultRateLimitBytesPerSec?: number;
+  /** Default burst size for new clients (bytes). Omit for unlimited. */
+  defaultBurstBytes?: number;
+  /** Transport mode: 'both' (default, WS+QUIC), 'websocket', 'quic', or 'wireguard' */
+  transportMode?: 'websocket' | 'quic' | 'both' | 'wireguard';
+  /** QUIC listen address (host:port). Defaults to listenAddr. */
+  quicListenAddr?: string;
+  /** QUIC idle timeout in seconds (default: 30) */
+  quicIdleTimeoutSecs?: number;
+  /** WireGuard: UDP listen port (default: 51820) */
+  wgListenPort?: number;
+  /** WireGuard: configured peers */
+  wgPeers?: IWgPeerConfig[];
+  /** Pre-registered clients for Noise IK authentication */
+  clients?: IClientEntry[];
+  /** Enable PROXY protocol v2 on incoming WebSocket connections.
+   *  Required when behind a reverse proxy that sends PP v2 headers (HAProxy, SmartProxy).
+   *  SECURITY: Must be false when accepting direct client connections. */
+  proxyProtocol?: boolean;
+  /** Server-level IP block list — applied at TCP accept, before Noise handshake.
+   *  Supports exact IPs, CIDR, wildcards, ranges. */
+  connectionIpBlockList?: string[];
 }
 
 export interface IVpnServerOptions {
@@ -99,6 +150,7 @@ export interface IVpnStatistics {
   keepalivesSent: number;
   keepalivesReceived: number;
   uptimeSeconds: number;
+  quality?: IVpnConnectionQuality;
 }
 
 export interface IVpnClientInfo {
@@ -107,6 +159,18 @@ export interface IVpnClientInfo {
   connectedSince: string;
   bytesSent: number;
   bytesReceived: number;
+  packetsDropped: number;
+  bytesDropped: number;
+  lastKeepaliveAt?: string;
+  keepalivesReceived: number;
+  rateLimitBytesPerSec?: number;
+  burstBytes?: number;
+  /** Client's authenticated Noise IK public key (base64) */
+  authenticatedKey: string;
+  /** Registered client ID from the client registry */
+  registeredClientId: string;
+  /** Real client IP:port (from PROXY protocol or direct TCP connection) */
+  remoteAddr?: string;
 }
 
 export interface IVpnServerStatistics extends IVpnStatistics {
@@ -119,6 +183,160 @@ export interface IVpnKeypair {
   privateKey: string;
 }
 
+// ============================================================================
+// QoS: Connection quality
+// ============================================================================
+
+export type TVpnLinkHealth = 'healthy' | 'degraded' | 'critical';
+
+export interface IVpnConnectionQuality {
+  srttMs: number;
+  jitterMs: number;
+  minRttMs: number;
+  maxRttMs: number;
+  lossRatio: number;
+  consecutiveTimeouts: number;
+  linkHealth: TVpnLinkHealth;
+  currentKeepaliveIntervalSecs: number;
+}
+
+// ============================================================================
+// QoS: MTU info
+// ============================================================================
+
+export interface IVpnMtuInfo {
+  tunMtu: number;
+  effectiveMtu: number;
+  linkMtu: number;
+  overheadBytes: number;
+  oversizedPacketsDropped: number;
+  icmpTooBigSent: number;
+}
+
+// ============================================================================
+// QoS: Client telemetry (server-side per-client)
+// ============================================================================
+
+export interface IVpnClientTelemetry {
+  clientId: string;
+  assignedIp: string;
+  lastKeepaliveAt?: string;
+  keepalivesReceived: number;
+  packetsDropped: number;
+  bytesDropped: number;
+  bytesReceived: number;
+  bytesSent: number;
+  rateLimitBytesPerSec?: number;
+  burstBytes?: number;
+}
+
+// ============================================================================
+// Client Registry (Hub) types — aligned with SmartProxy IRouteSecurity pattern
+// ============================================================================
+
+/** Per-client rate limiting. */
+export interface IClientRateLimit {
+  /** Max throughput in bytes/sec */
+  bytesPerSec: number;
+  /** Burst allowance in bytes */
+  burstBytes: number;
+}
+
+/**
+ * Per-client security settings.
+ * Mirrors SmartProxy's IRouteSecurity: ipAllowList/ipBlockList naming + deny-overrides-allow.
+ * Adds VPN-specific destination filtering.
+ */
+export interface IClientSecurity {
+  /** Source IPs/CIDRs the client may connect FROM (empty = any).
+   *  Supports: exact IP, CIDR, wildcard (192.168.1.*), ranges (1.1.1.1-1.1.1.5). */
+  ipAllowList?: string[];
+  /** Source IPs blocked — overrides ipAllowList (deny wins). */
+  ipBlockList?: string[];
+  /** Destination IPs/CIDRs the client may reach through the VPN (empty = all). */
+  destinationAllowList?: string[];
+  /** Destination IPs blocked — overrides destinationAllowList (deny wins). */
+  destinationBlockList?: string[];
+  /** Max concurrent connections from this client. */
+  maxConnections?: number;
+  /** Per-client rate limiting. */
+  rateLimit?: IClientRateLimit;
+}
+
+/**
+ * Server-side client definition — the central config object for the Hub.
+ * Naming and structure aligned with SmartProxy's IRouteConfig / IRouteSecurity.
+ */
+export interface IClientEntry {
+  /** Human-readable client ID (e.g. "alice-laptop") */
+  clientId: string;
+  /** Client's Noise IK public key (base64) — for SmartVPN native transport */
+  publicKey: string;
+  /** Client's WireGuard public key (base64) — for WireGuard transport */
+  wgPublicKey?: string;
+  /** Security settings (ACLs, rate limits) */
+  security?: IClientSecurity;
+  /** Traffic priority (lower = higher priority, default: 100) */
+  priority?: number;
+  /** Whether this client is enabled (default: true) */
+  enabled?: boolean;
+  /** Tags for grouping (e.g. ["engineering", "office"]) */
+  tags?: string[];
+  /** Optional description */
+  description?: string;
+  /** Optional expiry (ISO 8601 timestamp, omit = never expires) */
+  expiresAt?: string;
+  /** Assigned VPN IP address (set by server) */
+  assignedIp?: string;
+}
+
+/**
+ * Complete client config bundle — returned by createClient() and rotateClientKey().
+ * Contains everything the client needs to connect.
+ */
+export interface IClientConfigBundle {
+  /** The server-side client entry */
+  entry: IClientEntry;
+  /** Ready-to-use SmartVPN client config (typed object) */
+  smartvpnConfig: IVpnClientConfig;
+  /** Ready-to-use WireGuard .conf file content (string) */
+  wireguardConfig: string;
+  /** Client's private keys (ONLY returned at creation time, not stored server-side) */
+  secrets: {
+    noisePrivateKey: string;
+    wgPrivateKey: string;
+  };
+}
+
+// ============================================================================
+// WireGuard-specific types
+// ============================================================================
+
+export interface IWgPeerConfig {
+  /** Peer's public key (base64, X25519) */
+  publicKey: string;
+  /** Optional preshared key (base64) */
+  presharedKey?: string;
+  /** Allowed IP ranges (CIDR strings) */
+  allowedIps: string[];
+  /** Peer endpoint (host:port) — optional for server peers, required for client */
+  endpoint?: string;
+  /** Persistent keepalive interval in seconds */
+  persistentKeepalive?: number;
+}
+
+export interface IWgPeerInfo {
+  publicKey: string;
+  allowedIps: string[];
+  endpoint?: string;
+  persistentKeepalive?: number;
+  bytesSent: number;
+  bytesReceived: number;
+  packetsSent: number;
+  packetsReceived: number;
+  lastHandshakeTime?: string;
+}
+
 // ============================================================================
 // IPC Command maps (used by smartrust RustBridge<TCommands>)
 // ============================================================================
@@ -128,6 +346,8 @@ export type TVpnClientCommands = {
   disconnect: { params: Record<string, never>; result: void };
   getStatus: { params: Record<string, never>; result: IVpnStatus };
   getStatistics: { params: Record<string, never>; result: IVpnStatistics };
+  getConnectionQuality: { params: Record<string, never>; result: IVpnConnectionQuality };
+  getMtuInfo: { params: Record<string, never>; result: IVpnMtuInfo };
 };
 
 export type TVpnServerCommands = {
@@ -138,6 +358,24 @@ export type TVpnServerCommands = {
   listClients: { params: Record<string, never>; result: { clients: IVpnClientInfo[] } };
   disconnectClient: { params: { clientId: string }; result: void };
   generateKeypair: { params: Record<string, never>; result: IVpnKeypair };
+  setClientRateLimit: { params: { clientId: string; rateBytesPerSec: number; burstBytes: number }; result: void };
+  removeClientRateLimit: { params: { clientId: string }; result: void };
+  getClientTelemetry: { params: { clientId: string }; result: IVpnClientTelemetry };
+  generateWgKeypair: { params: Record<string, never>; result: IVpnKeypair };
+  addWgPeer: { params: { peer: IWgPeerConfig }; result: void };
+  removeWgPeer: { params: { publicKey: string }; result: void };
+  listWgPeers: { params: Record<string, never>; result: { peers: IWgPeerInfo[] } };
+  // Client Registry (Hub) commands
+  createClient: { params: { client: Partial<IClientEntry> }; result: IClientConfigBundle };
+  removeClient: { params: { clientId: string }; result: void };
+  getClient: { params: { clientId: string }; result: IClientEntry };
+  listRegisteredClients: { params: Record<string, never>; result: { clients: IClientEntry[] } };
+  updateClient: { params: { clientId: string; update: Partial<IClientEntry> }; result: void };
+  enableClient: { params: { clientId: string }; result: void };
+  disableClient: { params: { clientId: string }; result: void };
+  rotateClientKey: { params: { clientId: string }; result: IClientConfigBundle };
+  exportClientConfig: { params: { clientId: string; format: 'smartvpn' | 'wireguard' }; result: { config: string } };
+  generateClientKeypair: { params: Record<string, never>; result: IVpnKeypair };
 };
 
 // ============================================================================

tsconfig.json

@@ -6,7 +6,8 @@
     "module": "NodeNext",
     "moduleResolution": "NodeNext",
     "esModuleInterop": true,
-    "verbatimModuleSyntax": true
+    "verbatimModuleSyntax": true,
+    "types": ["node"]
   },
   "exclude": [
     "dist_ts/**/*.d.ts"