feat(smart-proxy): add UDP transport support with QUIC/HTTP3 routing and datagram handler relay

ts/proxies/smart-proxy/models/metrics-types.ts

@@ -74,6 +74,14 @@ export interface IMetrics {
     topByErrors(limit?: number): Array<{ backend: string; errors: number }>;
   };
 
+  // UDP metrics
+  udp: {
+    activeSessions(): number;
+    totalSessions(): number;
+    datagramsIn(): number;
+    datagramsOut(): number;
+  };
+
   // Performance metrics
   percentiles: {
     connectionDuration(): { p50: number; p95: number; p99: number };

ts/proxies/smart-proxy/models/route-types.ts

@@ -20,9 +20,15 @@ export type TSocketHandler = (socket: plugins.net.Socket, context: IRouteContext
 export type TTlsMode = 'passthrough' | 'terminate' | 'terminate-and-reencrypt';
 
 /**
- * Port range specification format
+ * Transport protocol for route matching
  */
-export type TPortRange = number | number[] | Array<{ from: number; to: number }>;
+export type TTransportProtocol = 'tcp' | 'udp' | 'all';
+
+/**
+ * Port range specification format.
+ * Supports: single number, array of numbers, array of ranges, or mixed arrays.
+ */
+export type TPortRange = number | Array<number | { from: number; to: number }>;
 
 /**
  * Route match criteria for incoming requests
@@ -31,6 +37,9 @@ export interface IRouteMatch {
   // Listen on these ports (required)
   ports: TPortRange;
 
+  // Transport protocol: 'tcp' (default), 'udp', or 'all' (both TCP and UDP)
+  transport?: TTransportProtocol;
+
   // Optional domain patterns to match (default: all domains)
   domains?: string | string[];
 
@@ -39,7 +48,7 @@ export interface IRouteMatch {
   clientIp?: string[];     // Match specific client IPs
   tlsVersion?: string[];   // Match specific TLS versions
   headers?: Record<string, string | RegExp>; // Match specific HTTP headers
-  protocol?: 'http' | 'tcp';  // Match specific protocol (http includes h2 + websocket upgrades)
+  protocol?: 'http' | 'tcp' | 'udp' | 'quic' | 'http3';  // Match specific protocol
 }
 
 
@@ -72,6 +81,9 @@ export interface IRouteTarget {
   headers?: IRouteHeaders;                     // Override route-level headers
   advanced?: IRouteAdvanced;                   // Override route-level advanced settings
   
+  // Override transport for backend connection (e.g., receive QUIC but forward as HTTP/1.1 via TCP)
+  backendTransport?: 'tcp' | 'udp';
+
   // Priority for matching (higher values are checked first, default: 0)
   priority?: number;
 }
@@ -262,7 +274,7 @@ export interface IRouteAction {
   
   // Additional options for backend-specific settings
   options?: {
-    backendProtocol?: 'http1' | 'http2' | 'auto';
+    backendProtocol?: 'http1' | 'http2' | 'http3' | 'auto';
     [key: string]: any;
   };
 
@@ -274,9 +286,15 @@ export interface IRouteAction {
 
   // Socket handler function (when type is 'socket-handler')
   socketHandler?: TSocketHandler;
-  
+
+  // Datagram handler function for UDP (when type is 'socket-handler' and transport is 'udp')
+  datagramHandler?: TDatagramHandler;
+
   // PROXY protocol support (default for all targets, can be overridden per target)
   sendProxyProtocol?: boolean;
+
+  // UDP-specific settings (session tracking, datagram limits, QUIC config)
+  udp?: IRouteUdp;
 }
 
 /**
@@ -356,4 +374,64 @@ export interface IRouteConfig {
   enabled?: boolean;         // Whether the route is active (default: true)
 }
 
+// ─── UDP & QUIC Types ─────────────────────────────────────────────────
+
+/**
+ * Handler for individual UDP datagrams.
+ * Called for each incoming datagram on a socket-handler route with UDP transport.
+ */
+export type TDatagramHandler = (
+  datagram: Buffer,
+  info: IDatagramInfo,
+  reply: (data: Buffer) => void
+) => void | Promise<void>;
+
+/**
+ * Metadata for a received UDP datagram
+ */
+export interface IDatagramInfo {
+  /** Source IP address */
+  sourceIp: string;
+  /** Source port */
+  sourcePort: number;
+  /** Destination (local) port the datagram arrived on */
+  destPort: number;
+  /** Route context */
+  context: IRouteContext;
+}
+
+/**
+ * UDP-specific settings for route actions
+ */
+export interface IRouteUdp {
+  /** Idle timeout for a UDP session/flow (keyed by src IP:port), in ms. Default: 60000 */
+  sessionTimeout?: number;
+  /** Max concurrent UDP sessions per source IP. Default: 1000 */
+  maxSessionsPerIP?: number;
+  /** Max accepted datagram size in bytes. Oversized datagrams are dropped. Default: 65535 */
+  maxDatagramSize?: number;
+  /** QUIC-specific configuration. When present, traffic is treated as QUIC. */
+  quic?: IRouteQuic;
+}
+
+/**
+ * QUIC and HTTP/3 settings
+ */
+export interface IRouteQuic {
+  /** QUIC connection idle timeout in ms. Default: 30000 */
+  maxIdleTimeout?: number;
+  /** Max concurrent bidirectional streams per QUIC connection. Default: 100 */
+  maxConcurrentBidiStreams?: number;
+  /** Max concurrent unidirectional streams per QUIC connection. Default: 100 */
+  maxConcurrentUniStreams?: number;
+  /** Enable HTTP/3 over this QUIC endpoint. Default: false */
+  enableHttp3?: boolean;
+  /** Port to advertise in Alt-Svc header on TCP HTTP responses. Default: listening port */
+  altSvcPort?: number;
+  /** Max age for Alt-Svc advertisement in seconds. Default: 86400 */
+  altSvcMaxAge?: number;
+  /** Initial congestion window size in bytes. Default: implementation-defined */
+  initialCongestionWindow?: number;
+}
+
 // Configuration moved to models/interfaces.ts as ISmartProxyOptions