Files
remoteingress/rust/crates/remoteingress-protocol/src/lib.rs

874 lines
34 KiB
Rust

use std::collections::VecDeque;
use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};
use std::time::Duration;
use bytes::{Bytes, BytesMut, BufMut};
use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, ReadBuf};
use tokio::time::Instant;
// Frame type constants
pub const FRAME_OPEN: u8 = 0x01;
pub const FRAME_DATA: u8 = 0x02;
pub const FRAME_CLOSE: u8 = 0x03;
pub const FRAME_DATA_BACK: u8 = 0x04;
pub const FRAME_CLOSE_BACK: u8 = 0x05;
pub const FRAME_CONFIG: u8 = 0x06; // Hub -> Edge: configuration update
pub const FRAME_PING: u8 = 0x07; // Hub -> Edge: heartbeat probe
pub const FRAME_PONG: u8 = 0x08; // Edge -> Hub: heartbeat response
pub const FRAME_WINDOW_UPDATE: u8 = 0x09; // Edge -> Hub: per-stream flow control
pub const FRAME_WINDOW_UPDATE_BACK: u8 = 0x0A; // Hub -> Edge: per-stream flow control
// Frame header size: 4 (stream_id) + 1 (type) + 4 (length) = 9 bytes
pub const FRAME_HEADER_SIZE: usize = 9;
// Maximum payload size (16 MB)
pub const MAX_PAYLOAD_SIZE: u32 = 16 * 1024 * 1024;
// Per-stream flow control constants
/// Initial (and maximum) per-stream window size (4 MB).
pub const INITIAL_STREAM_WINDOW: u32 = 4 * 1024 * 1024;
/// Send WINDOW_UPDATE after consuming this many bytes (half the initial window).
pub const WINDOW_UPDATE_THRESHOLD: u32 = INITIAL_STREAM_WINDOW / 2;
/// Maximum window size to prevent overflow.
pub const MAX_WINDOW_SIZE: u32 = 4 * 1024 * 1024;
// Sustained stream classification constants
/// Throughput threshold for sustained classification (2.5 MB/s = 20 Mbit/s).
pub const SUSTAINED_THRESHOLD_BPS: u64 = 2_500_000;
/// Minimum duration before a stream can be classified as sustained.
pub const SUSTAINED_MIN_DURATION_SECS: u64 = 10;
/// Fixed window for sustained streams (1 MB — the floor).
pub const SUSTAINED_WINDOW: u32 = 1 * 1024 * 1024;
/// Maximum bytes written from sustained queue per forced drain (1 MB/s guarantee).
pub const SUSTAINED_FORCED_DRAIN_CAP: usize = 1_048_576;
/// Encode a WINDOW_UPDATE frame for a specific stream.
pub fn encode_window_update(stream_id: u32, frame_type: u8, increment: u32) -> Bytes {
encode_frame(stream_id, frame_type, &increment.to_be_bytes())
}
/// Compute the target per-stream window size based on the number of active streams.
/// Total memory budget is ~200MB shared across all streams. Up to 50 streams get the
/// full 4MB window; above that the window scales down to a 1MB floor at 200+ streams.
pub fn compute_window_for_stream_count(active: u32) -> u32 {
let per_stream = (200 * 1024 * 1024u64) / (active.max(1) as u64);
per_stream.clamp(1 * 1024 * 1024, INITIAL_STREAM_WINDOW as u64) as u32
}
/// Decode a WINDOW_UPDATE payload into a byte increment. Returns None if payload is malformed.
pub fn decode_window_update(payload: &[u8]) -> Option<u32> {
if payload.len() != 4 {
return None;
}
Some(u32::from_be_bytes([payload[0], payload[1], payload[2], payload[3]]))
}
/// A single multiplexed frame.
#[derive(Debug, Clone)]
pub struct Frame {
pub stream_id: u32,
pub frame_type: u8,
pub payload: Bytes,
}
/// Encode a frame into bytes: [stream_id:4][type:1][length:4][payload]
pub fn encode_frame(stream_id: u32, frame_type: u8, payload: &[u8]) -> Bytes {
let len = payload.len() as u32;
let mut buf = BytesMut::with_capacity(FRAME_HEADER_SIZE + payload.len());
buf.put_slice(&stream_id.to_be_bytes());
buf.put_u8(frame_type);
buf.put_slice(&len.to_be_bytes());
buf.put_slice(payload);
buf.freeze()
}
/// Write a frame header into `buf[0..FRAME_HEADER_SIZE]`.
/// The caller must ensure payload is already at `buf[FRAME_HEADER_SIZE..FRAME_HEADER_SIZE + payload_len]`.
/// This enables zero-copy encoding: read directly into `buf[FRAME_HEADER_SIZE..]`, then
/// prepend the header without copying the payload.
pub fn encode_frame_header(buf: &mut [u8], stream_id: u32, frame_type: u8, payload_len: usize) {
buf[0..4].copy_from_slice(&stream_id.to_be_bytes());
buf[4] = frame_type;
buf[5..9].copy_from_slice(&(payload_len as u32).to_be_bytes());
}
/// Build a PROXY protocol v1 header line.
/// Format: `PROXY TCP4 <client_ip> <edge_ip> <client_port> <dest_port>\r\n`
pub fn build_proxy_v1_header(
client_ip: &str,
edge_ip: &str,
client_port: u16,
dest_port: u16,
) -> String {
format!(
"PROXY TCP4 {} {} {} {}\r\n",
client_ip, edge_ip, client_port, dest_port
)
}
/// Stateful async frame reader that yields `Frame` values from an `AsyncRead`.
pub struct FrameReader<R> {
reader: R,
header_buf: [u8; FRAME_HEADER_SIZE],
}
impl<R: AsyncRead + Unpin> FrameReader<R> {
pub fn new(reader: R) -> Self {
Self {
reader,
header_buf: [0u8; FRAME_HEADER_SIZE],
}
}
/// Read the next frame. Returns `None` on EOF, `Err` on protocol violation.
pub async fn next_frame(&mut self) -> Result<Option<Frame>, std::io::Error> {
// Read header
match self.reader.read_exact(&mut self.header_buf).await {
Ok(_) => {}
Err(e) if e.kind() == std::io::ErrorKind::UnexpectedEof => return Ok(None),
Err(e) => return Err(e),
}
let stream_id = u32::from_be_bytes([
self.header_buf[0],
self.header_buf[1],
self.header_buf[2],
self.header_buf[3],
]);
let frame_type = self.header_buf[4];
let length = u32::from_be_bytes([
self.header_buf[5],
self.header_buf[6],
self.header_buf[7],
self.header_buf[8],
]);
if length > MAX_PAYLOAD_SIZE {
log::error!(
"CORRUPT FRAME HEADER: raw={:02x?} stream_id={} type=0x{:02x} length={}",
self.header_buf, stream_id, frame_type, length
);
return Err(std::io::Error::new(
std::io::ErrorKind::InvalidData,
format!("frame payload too large: {} bytes (header={:02x?})", length, self.header_buf),
));
}
let mut payload = BytesMut::zeroed(length as usize);
if length > 0 {
self.reader.read_exact(&mut payload).await?;
}
Ok(Some(Frame {
stream_id,
frame_type,
payload: payload.freeze(),
}))
}
/// Consume the reader and return the inner stream.
pub fn into_inner(self) -> R {
self.reader
}
}
// ---------------------------------------------------------------------------
// TunnelIo: single-owner I/O multiplexer for the TLS tunnel connection
// ---------------------------------------------------------------------------
/// Events produced by the TunnelIo event loop.
#[derive(Debug)]
pub enum TunnelEvent {
/// A complete frame was read from the remote side.
Frame(Frame),
/// The remote side closed the connection (EOF).
Eof,
/// A read error occurred.
ReadError(std::io::Error),
/// A write error occurred.
WriteError(std::io::Error),
/// No frames received for the liveness timeout duration.
LivenessTimeout,
/// The cancellation token was triggered.
Cancelled,
}
/// Write state extracted into a sub-struct so the borrow checker can see
/// disjoint field access between `self.write` and `self.stream`.
struct WriteState {
ctrl_queue: VecDeque<Bytes>, // PONG, WINDOW_UPDATE, CLOSE, OPEN — always first
data_queue: VecDeque<Bytes>, // DATA, DATA_BACK — only when ctrl is empty
sustained_queue: VecDeque<Bytes>, // DATA, DATA_BACK from sustained streams — lowest priority
offset: usize, // progress within current frame being written
flush_needed: bool,
// Sustained starvation prevention: guaranteed 1 MB/s drain
sustained_last_drain: Instant,
sustained_bytes_this_period: usize,
}
impl WriteState {
fn has_work(&self) -> bool {
!self.ctrl_queue.is_empty() || !self.data_queue.is_empty() || !self.sustained_queue.is_empty()
}
}
/// Single-owner I/O engine for the tunnel TLS connection.
///
/// Owns the TLS stream directly — no `tokio::io::split()`, no mutex.
/// Uses three priority write queues:
/// 1. ctrl (PONG, WINDOW_UPDATE, CLOSE, OPEN) — always first
/// 2. data (DATA, DATA_BACK from normal streams) — when ctrl empty
/// 3. sustained (DATA, DATA_BACK from sustained streams) — lowest priority,
/// drained freely when ctrl+data empty, or forced 1MB/s when they're not
pub struct TunnelIo<S> {
stream: S,
// Read state: accumulate bytes, parse frames incrementally
read_buf: Vec<u8>,
read_pos: usize,
parse_pos: usize,
// Write state: extracted sub-struct for safe disjoint borrows
write: WriteState,
}
impl<S: AsyncRead + AsyncWrite + Unpin> TunnelIo<S> {
pub fn new(stream: S, initial_data: Vec<u8>) -> Self {
let read_pos = initial_data.len();
let mut read_buf = initial_data;
if read_buf.capacity() < 65536 {
read_buf.reserve(65536 - read_buf.len());
}
Self {
stream,
read_buf,
read_pos,
parse_pos: 0,
write: WriteState {
ctrl_queue: VecDeque::new(),
data_queue: VecDeque::new(),
sustained_queue: VecDeque::new(),
offset: 0,
flush_needed: false,
sustained_last_drain: Instant::now(),
sustained_bytes_this_period: 0,
},
}
}
/// Queue a high-priority control frame (PONG, WINDOW_UPDATE, CLOSE, OPEN).
pub fn queue_ctrl(&mut self, frame: Bytes) {
self.write.ctrl_queue.push_back(frame);
}
/// Queue a lower-priority data frame (DATA, DATA_BACK).
pub fn queue_data(&mut self, frame: Bytes) {
self.write.data_queue.push_back(frame);
}
/// Queue a lowest-priority sustained data frame.
pub fn queue_sustained(&mut self, frame: Bytes) {
self.write.sustained_queue.push_back(frame);
}
/// Try to parse a complete frame from the read buffer.
/// Uses a parse_pos cursor to avoid drain() on every frame.
pub fn try_parse_frame(&mut self) -> Option<Result<Frame, std::io::Error>> {
let available = self.read_pos - self.parse_pos;
if available < FRAME_HEADER_SIZE {
return None;
}
let base = self.parse_pos;
let stream_id = u32::from_be_bytes([
self.read_buf[base], self.read_buf[base + 1],
self.read_buf[base + 2], self.read_buf[base + 3],
]);
let frame_type = self.read_buf[base + 4];
let length = u32::from_be_bytes([
self.read_buf[base + 5], self.read_buf[base + 6],
self.read_buf[base + 7], self.read_buf[base + 8],
]);
if length > MAX_PAYLOAD_SIZE {
let header = [
self.read_buf[base], self.read_buf[base + 1],
self.read_buf[base + 2], self.read_buf[base + 3],
self.read_buf[base + 4], self.read_buf[base + 5],
self.read_buf[base + 6], self.read_buf[base + 7],
self.read_buf[base + 8],
];
log::error!(
"CORRUPT FRAME HEADER: raw={:02x?} stream_id={} type=0x{:02x} length={}",
header, stream_id, frame_type, length
);
return Some(Err(std::io::Error::new(
std::io::ErrorKind::InvalidData,
format!("frame payload too large: {} bytes (header={:02x?})", length, header),
)));
}
let total_frame_size = FRAME_HEADER_SIZE + length as usize;
if available < total_frame_size {
return None;
}
let payload = Bytes::copy_from_slice(
&self.read_buf[base + FRAME_HEADER_SIZE..base + total_frame_size],
);
self.parse_pos += total_frame_size;
// Compact when parse_pos > half the data to reclaim memory
if self.parse_pos > self.read_pos / 2 && self.parse_pos > 0 {
self.read_buf.drain(..self.parse_pos);
self.read_pos -= self.parse_pos;
self.parse_pos = 0;
}
Some(Ok(Frame { stream_id, frame_type, payload }))
}
/// Poll-based I/O step. Returns Ready on events, Pending when idle.
///
/// Order: write(ctrl->data->sustained) -> flush -> read -> channels -> timers
pub fn poll_step(
&mut self,
cx: &mut Context<'_>,
ctrl_rx: &mut tokio::sync::mpsc::Receiver<Bytes>,
data_rx: &mut tokio::sync::mpsc::Receiver<Bytes>,
sustained_rx: &mut tokio::sync::mpsc::Receiver<Bytes>,
liveness_deadline: &mut Pin<Box<tokio::time::Sleep>>,
cancel_token: &tokio_util::sync::CancellationToken,
) -> Poll<TunnelEvent> {
// 1. WRITE: 3-tier priority — ctrl first, then data, then sustained.
// Sustained drains freely when ctrl+data are empty.
// Write one frame, set flush_needed, then flush must complete before
// writing more. This prevents unbounded TLS session buffer growth.
// Safe: `self.write` and `self.stream` are disjoint fields.
let mut writes = 0;
while self.write.has_work() && writes < 16 && !self.write.flush_needed {
// Pick queue: ctrl > data > sustained
let queue_id = if !self.write.ctrl_queue.is_empty() {
0 // ctrl
} else if !self.write.data_queue.is_empty() {
1 // data
} else {
2 // sustained
};
let frame = match queue_id {
0 => self.write.ctrl_queue.front().unwrap(),
1 => self.write.data_queue.front().unwrap(),
_ => self.write.sustained_queue.front().unwrap(),
};
let remaining = &frame[self.write.offset..];
match Pin::new(&mut self.stream).poll_write(cx, remaining) {
Poll::Ready(Ok(0)) => {
log::error!("TunnelIo: poll_write returned 0 (write zero), ctrl_q={} data_q={} sustained_q={}",
self.write.ctrl_queue.len(), self.write.data_queue.len(), self.write.sustained_queue.len());
return Poll::Ready(TunnelEvent::WriteError(
std::io::Error::new(std::io::ErrorKind::WriteZero, "write zero"),
));
}
Poll::Ready(Ok(n)) => {
self.write.offset += n;
self.write.flush_needed = true;
if self.write.offset >= frame.len() {
match queue_id {
0 => { self.write.ctrl_queue.pop_front(); }
1 => { self.write.data_queue.pop_front(); }
_ => {
self.write.sustained_queue.pop_front();
self.write.sustained_last_drain = Instant::now();
self.write.sustained_bytes_this_period = 0;
}
}
self.write.offset = 0;
writes += 1;
}
}
Poll::Ready(Err(e)) => {
log::error!("TunnelIo: poll_write error: {} (ctrl_q={} data_q={} sustained_q={})",
e, self.write.ctrl_queue.len(), self.write.data_queue.len(), self.write.sustained_queue.len());
return Poll::Ready(TunnelEvent::WriteError(e));
}
Poll::Pending => break,
}
}
// 1b. FORCED SUSTAINED DRAIN: when ctrl/data have work but sustained is waiting,
// guarantee at least 1 MB/s by draining up to SUSTAINED_FORCED_DRAIN_CAP
// once per second.
if !self.write.sustained_queue.is_empty()
&& (!self.write.ctrl_queue.is_empty() || !self.write.data_queue.is_empty())
&& !self.write.flush_needed
{
let now = Instant::now();
if now.duration_since(self.write.sustained_last_drain) >= Duration::from_secs(1) {
self.write.sustained_bytes_this_period = 0;
self.write.sustained_last_drain = now;
while !self.write.sustained_queue.is_empty()
&& self.write.sustained_bytes_this_period < SUSTAINED_FORCED_DRAIN_CAP
&& !self.write.flush_needed
{
let frame = self.write.sustained_queue.front().unwrap();
let remaining = &frame[self.write.offset..];
match Pin::new(&mut self.stream).poll_write(cx, remaining) {
Poll::Ready(Ok(0)) => {
return Poll::Ready(TunnelEvent::WriteError(
std::io::Error::new(std::io::ErrorKind::WriteZero, "write zero"),
));
}
Poll::Ready(Ok(n)) => {
self.write.offset += n;
self.write.flush_needed = true;
self.write.sustained_bytes_this_period += n;
if self.write.offset >= frame.len() {
self.write.sustained_queue.pop_front();
self.write.offset = 0;
}
}
Poll::Ready(Err(e)) => {
return Poll::Ready(TunnelEvent::WriteError(e));
}
Poll::Pending => break,
}
}
}
}
// 2. FLUSH: push encrypted data from TLS session to TCP.
if self.write.flush_needed {
match Pin::new(&mut self.stream).poll_flush(cx) {
Poll::Ready(Ok(())) => {
self.write.flush_needed = false;
}
Poll::Ready(Err(e)) => {
log::error!("TunnelIo: poll_flush error: {}", e);
return Poll::Ready(TunnelEvent::WriteError(e));
}
Poll::Pending => {} // TCP waker will notify us
}
}
// 3. READ: drain stream until Pending to ensure the TCP waker is always registered.
// Without this loop, a Ready return with partial frame data would consume
// the waker without re-registering it, causing the task to sleep until a
// timer or channel wakes it (potentially 15+ seconds of lost reads).
loop {
// Compact if needed to make room for reads
if self.parse_pos > 0 && self.read_buf.len() - self.read_pos < 32768 {
self.read_buf.drain(..self.parse_pos);
self.read_pos -= self.parse_pos;
self.parse_pos = 0;
}
if self.read_buf.len() < self.read_pos + 32768 {
self.read_buf.resize(self.read_pos + 32768, 0);
}
let mut rbuf = ReadBuf::new(&mut self.read_buf[self.read_pos..]);
match Pin::new(&mut self.stream).poll_read(cx, &mut rbuf) {
Poll::Ready(Ok(())) => {
let n = rbuf.filled().len();
if n == 0 {
return Poll::Ready(TunnelEvent::Eof);
}
self.read_pos += n;
if let Some(result) = self.try_parse_frame() {
return match result {
Ok(frame) => Poll::Ready(TunnelEvent::Frame(frame)),
Err(e) => Poll::Ready(TunnelEvent::ReadError(e)),
};
}
// Partial data — loop to call poll_read again so the TCP
// waker is re-registered when it finally returns Pending.
}
Poll::Ready(Err(e)) => {
log::error!("TunnelIo: poll_read error: {}", e);
return Poll::Ready(TunnelEvent::ReadError(e));
}
Poll::Pending => break,
}
}
// 4. CHANNELS: drain ctrl (always — priority), data (only if queue is small).
// Ctrl frames must never be delayed — always drain fully.
// Data frames are gated: keep data in the bounded channel for proper
// backpressure when TLS writes are slow. Without this gate, the internal
// data_queue (unbounded VecDeque) grows to hundreds of MB under throttle -> OOM.
let mut got_new = false;
loop {
match ctrl_rx.poll_recv(cx) {
Poll::Ready(Some(frame)) => { self.write.ctrl_queue.push_back(frame); got_new = true; }
Poll::Ready(None) => {
return Poll::Ready(TunnelEvent::WriteError(
std::io::Error::new(std::io::ErrorKind::BrokenPipe, "ctrl channel closed"),
));
}
Poll::Pending => break,
}
}
if self.write.data_queue.len() < 64 {
loop {
match data_rx.poll_recv(cx) {
Poll::Ready(Some(frame)) => { self.write.data_queue.push_back(frame); got_new = true; }
Poll::Ready(None) => {
return Poll::Ready(TunnelEvent::WriteError(
std::io::Error::new(std::io::ErrorKind::BrokenPipe, "data channel closed"),
));
}
Poll::Pending => break,
}
}
}
// Sustained channel: drain when sustained_queue is small (same backpressure pattern).
// Channel close is non-fatal — not all connections have sustained streams.
if self.write.sustained_queue.len() < 64 {
loop {
match sustained_rx.poll_recv(cx) {
Poll::Ready(Some(frame)) => { self.write.sustained_queue.push_back(frame); got_new = true; }
Poll::Ready(None) | Poll::Pending => break,
}
}
}
// 5. TIMERS
if liveness_deadline.as_mut().poll(cx).is_ready() {
return Poll::Ready(TunnelEvent::LivenessTimeout);
}
if cancel_token.is_cancelled() {
return Poll::Ready(TunnelEvent::Cancelled);
}
// 6. SELF-WAKE: only when flush is complete AND we have work.
// When flush is Pending, the TCP write-readiness waker will notify us.
// CRITICAL: do NOT self-wake when flush_needed — poll_write always returns
// Ready (TLS buffers in-memory), so self-waking causes a tight spin loop
// that fills the TLS session buffer unboundedly -> OOM -> ECONNRESET.
if !self.write.flush_needed && (got_new || self.write.has_work()) {
cx.waker().wake_by_ref();
}
Poll::Pending
}
pub fn into_inner(self) -> S {
self.stream
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_encode_frame_header() {
let payload = b"hello";
let mut buf = vec![0u8; FRAME_HEADER_SIZE + payload.len()];
buf[FRAME_HEADER_SIZE..].copy_from_slice(payload);
encode_frame_header(&mut buf, 42, FRAME_DATA, payload.len());
assert_eq!(buf, &encode_frame(42, FRAME_DATA, payload)[..]);
}
#[test]
fn test_encode_frame_header_empty_payload() {
let mut buf = vec![0u8; FRAME_HEADER_SIZE];
encode_frame_header(&mut buf, 99, FRAME_CLOSE, 0);
assert_eq!(buf, &encode_frame(99, FRAME_CLOSE, &[])[..]);
}
#[test]
fn test_encode_frame() {
let data = b"hello";
let encoded = encode_frame(42, FRAME_DATA, data);
assert_eq!(encoded.len(), FRAME_HEADER_SIZE + data.len());
// stream_id = 42 in BE
assert_eq!(&encoded[0..4], &42u32.to_be_bytes());
// frame type
assert_eq!(encoded[4], FRAME_DATA);
// length
assert_eq!(&encoded[5..9], &5u32.to_be_bytes());
// payload
assert_eq!(&encoded[9..], b"hello");
}
#[test]
fn test_encode_empty_frame() {
let encoded = encode_frame(1, FRAME_CLOSE, &[]);
assert_eq!(encoded.len(), FRAME_HEADER_SIZE);
assert_eq!(&encoded[5..9], &0u32.to_be_bytes());
}
#[test]
fn test_proxy_v1_header() {
let header = build_proxy_v1_header("1.2.3.4", "5.6.7.8", 12345, 443);
assert_eq!(header, "PROXY TCP4 1.2.3.4 5.6.7.8 12345 443\r\n");
}
#[tokio::test]
async fn test_frame_reader() {
let frame1 = encode_frame(1, FRAME_OPEN, b"PROXY TCP4 1.2.3.4 5.6.7.8 1234 443\r\n");
let frame2 = encode_frame(1, FRAME_DATA, b"GET / HTTP/1.1\r\n");
let frame3 = encode_frame(1, FRAME_CLOSE, &[]);
let mut data = Vec::new();
data.extend_from_slice(&frame1);
data.extend_from_slice(&frame2);
data.extend_from_slice(&frame3);
let cursor = std::io::Cursor::new(data);
let mut reader = FrameReader::new(cursor);
let f1 = reader.next_frame().await.unwrap().unwrap();
assert_eq!(f1.stream_id, 1);
assert_eq!(f1.frame_type, FRAME_OPEN);
assert!(f1.payload.starts_with(b"PROXY"));
let f2 = reader.next_frame().await.unwrap().unwrap();
assert_eq!(f2.frame_type, FRAME_DATA);
let f3 = reader.next_frame().await.unwrap().unwrap();
assert_eq!(f3.frame_type, FRAME_CLOSE);
assert!(f3.payload.is_empty());
// EOF
assert!(reader.next_frame().await.unwrap().is_none());
}
#[test]
fn test_encode_frame_config_type() {
let payload = b"{\"listenPorts\":[443]}";
let encoded = encode_frame(0, FRAME_CONFIG, payload);
assert_eq!(encoded[4], FRAME_CONFIG);
assert_eq!(&encoded[0..4], &0u32.to_be_bytes());
assert_eq!(&encoded[9..], payload.as_slice());
}
#[test]
fn test_encode_frame_data_back_type() {
let payload = b"response data";
let encoded = encode_frame(7, FRAME_DATA_BACK, payload);
assert_eq!(encoded[4], FRAME_DATA_BACK);
assert_eq!(&encoded[0..4], &7u32.to_be_bytes());
assert_eq!(&encoded[5..9], &(payload.len() as u32).to_be_bytes());
assert_eq!(&encoded[9..], payload.as_slice());
}
#[test]
fn test_encode_frame_close_back_type() {
let encoded = encode_frame(99, FRAME_CLOSE_BACK, &[]);
assert_eq!(encoded[4], FRAME_CLOSE_BACK);
assert_eq!(&encoded[0..4], &99u32.to_be_bytes());
assert_eq!(&encoded[5..9], &0u32.to_be_bytes());
assert_eq!(encoded.len(), FRAME_HEADER_SIZE);
}
#[test]
fn test_encode_frame_large_stream_id() {
let encoded = encode_frame(u32::MAX, FRAME_DATA, b"x");
assert_eq!(&encoded[0..4], &u32::MAX.to_be_bytes());
assert_eq!(encoded[4], FRAME_DATA);
assert_eq!(&encoded[5..9], &1u32.to_be_bytes());
assert_eq!(encoded[9], b'x');
}
#[tokio::test]
async fn test_frame_reader_max_payload_rejection() {
let mut data = Vec::new();
data.extend_from_slice(&1u32.to_be_bytes());
data.push(FRAME_DATA);
data.extend_from_slice(&(MAX_PAYLOAD_SIZE + 1).to_be_bytes());
let cursor = std::io::Cursor::new(data);
let mut reader = FrameReader::new(cursor);
let result = reader.next_frame().await;
assert!(result.is_err());
let err = result.unwrap_err();
assert_eq!(err.kind(), std::io::ErrorKind::InvalidData);
}
#[tokio::test]
async fn test_frame_reader_eof_mid_header() {
// Only 5 bytes — not enough for a 9-byte header
let data = vec![0u8; 5];
let cursor = std::io::Cursor::new(data);
let mut reader = FrameReader::new(cursor);
// Should return Ok(None) on partial header EOF
let result = reader.next_frame().await;
assert!(result.unwrap().is_none());
}
#[tokio::test]
async fn test_frame_reader_eof_mid_payload() {
// Full header claiming 100 bytes of payload, but only 10 bytes present
let mut data = Vec::new();
data.extend_from_slice(&1u32.to_be_bytes());
data.push(FRAME_DATA);
data.extend_from_slice(&100u32.to_be_bytes());
data.extend_from_slice(&[0xAB; 10]);
let cursor = std::io::Cursor::new(data);
let mut reader = FrameReader::new(cursor);
let result = reader.next_frame().await;
assert!(result.is_err());
}
#[tokio::test]
async fn test_frame_reader_all_frame_types() {
let types = [
FRAME_OPEN,
FRAME_DATA,
FRAME_CLOSE,
FRAME_DATA_BACK,
FRAME_CLOSE_BACK,
FRAME_CONFIG,
FRAME_PING,
FRAME_PONG,
];
let mut data = Vec::new();
for (i, &ft) in types.iter().enumerate() {
let payload = format!("payload_{}", i);
data.extend_from_slice(&encode_frame(i as u32, ft, payload.as_bytes()));
}
let cursor = std::io::Cursor::new(data);
let mut reader = FrameReader::new(cursor);
for (i, &ft) in types.iter().enumerate() {
let frame = reader.next_frame().await.unwrap().unwrap();
assert_eq!(frame.stream_id, i as u32);
assert_eq!(frame.frame_type, ft);
assert_eq!(&frame.payload[..], format!("payload_{}", i).as_bytes());
}
assert!(reader.next_frame().await.unwrap().is_none());
}
#[tokio::test]
async fn test_frame_reader_zero_length_payload() {
let data = encode_frame(42, FRAME_CLOSE, &[]);
let cursor = std::io::Cursor::new(data.to_vec());
let mut reader = FrameReader::new(cursor);
let frame = reader.next_frame().await.unwrap().unwrap();
assert_eq!(frame.stream_id, 42);
assert_eq!(frame.frame_type, FRAME_CLOSE);
assert!(frame.payload.is_empty());
}
#[test]
fn test_encode_frame_ping_pong() {
// PING: stream_id=0, empty payload (control frame)
let ping = encode_frame(0, FRAME_PING, &[]);
assert_eq!(ping[4], FRAME_PING);
assert_eq!(&ping[0..4], &0u32.to_be_bytes());
assert_eq!(ping.len(), FRAME_HEADER_SIZE);
// PONG: stream_id=0, empty payload (control frame)
let pong = encode_frame(0, FRAME_PONG, &[]);
assert_eq!(pong[4], FRAME_PONG);
assert_eq!(&pong[0..4], &0u32.to_be_bytes());
assert_eq!(pong.len(), FRAME_HEADER_SIZE);
}
// --- compute_window_for_stream_count tests ---
#[test]
fn test_adaptive_window_zero_streams() {
// 0 streams treated as 1: 200MB/1 -> clamped to 4MB max
assert_eq!(compute_window_for_stream_count(0), INITIAL_STREAM_WINDOW);
}
#[test]
fn test_adaptive_window_one_stream() {
assert_eq!(compute_window_for_stream_count(1), INITIAL_STREAM_WINDOW);
}
#[test]
fn test_adaptive_window_50_streams_full() {
// 200MB/50 = 4MB = exactly INITIAL_STREAM_WINDOW
assert_eq!(compute_window_for_stream_count(50), INITIAL_STREAM_WINDOW);
}
#[test]
fn test_adaptive_window_51_streams_starts_scaling() {
// 200MB/51 < 4MB — first value below max
let w = compute_window_for_stream_count(51);
assert!(w < INITIAL_STREAM_WINDOW);
assert_eq!(w, (200 * 1024 * 1024u64 / 51) as u32);
}
#[test]
fn test_adaptive_window_100_streams() {
// 200MB/100 = 2MB
assert_eq!(compute_window_for_stream_count(100), 2 * 1024 * 1024);
}
#[test]
fn test_adaptive_window_200_streams_at_floor() {
// 200MB/200 = 1MB = exactly the floor
assert_eq!(compute_window_for_stream_count(200), 1 * 1024 * 1024);
}
#[test]
fn test_adaptive_window_500_streams_clamped() {
// 200MB/500 = 0.4MB -> clamped up to 1MB floor
assert_eq!(compute_window_for_stream_count(500), 1 * 1024 * 1024);
}
#[test]
fn test_adaptive_window_max_u32() {
// Extreme: u32::MAX streams -> tiny value -> clamped to 1MB
assert_eq!(compute_window_for_stream_count(u32::MAX), 1 * 1024 * 1024);
}
#[test]
fn test_adaptive_window_monotonically_decreasing() {
let mut prev = compute_window_for_stream_count(1);
for n in [2, 10, 50, 51, 100, 200, 500, 1000] {
let w = compute_window_for_stream_count(n);
assert!(w <= prev, "window increased from {} to {} at n={}", prev, w, n);
prev = w;
}
}
#[test]
fn test_adaptive_window_total_budget_bounded() {
// active x per_stream_window should never exceed 200MB (+ clamp overhead for high N)
for n in [1, 10, 50, 100, 200] {
let w = compute_window_for_stream_count(n);
let total = w as u64 * n as u64;
assert!(total <= 200 * 1024 * 1024, "total {}MB exceeds budget at n={}", total / (1024*1024), n);
}
}
// --- encode/decode window_update roundtrip ---
#[test]
fn test_window_update_roundtrip() {
for &increment in &[0u32, 1, 64 * 1024, INITIAL_STREAM_WINDOW, MAX_WINDOW_SIZE, u32::MAX] {
let frame = encode_window_update(42, FRAME_WINDOW_UPDATE, increment);
assert_eq!(frame[4], FRAME_WINDOW_UPDATE);
let decoded = decode_window_update(&frame[FRAME_HEADER_SIZE..]);
assert_eq!(decoded, Some(increment));
}
}
#[test]
fn test_window_update_back_roundtrip() {
let frame = encode_window_update(7, FRAME_WINDOW_UPDATE_BACK, 1234567);
assert_eq!(frame[4], FRAME_WINDOW_UPDATE_BACK);
assert_eq!(decode_window_update(&frame[FRAME_HEADER_SIZE..]), Some(1234567));
}
#[test]
fn test_decode_window_update_malformed() {
assert_eq!(decode_window_update(&[]), None);
assert_eq!(decode_window_update(&[0, 0, 0]), None);
assert_eq!(decode_window_update(&[0, 0, 0, 0, 0]), None);
}
}