feat(proxy): implement timeout handling for client payload reads and add corresponding tests

Cargo.lock

@@ -2093,7 +2093,7 @@ dependencies = [
 
 [[package]]
 name = "telemt"
-version = "3.3.18"
+version = "3.3.19"
 dependencies = [
  "aes",
  "anyhow",

src/proxy/middle_relay.rs

@@ -11,6 +11,7 @@ use bytes::{Bytes, BytesMut};
 use dashmap::DashMap;
 use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
 use tokio::sync::{mpsc, oneshot, watch};
+use tokio::time::timeout;
 use tracing::{debug, trace, warn};
 
 use crate::config::ProxyConfig;
@@ -581,6 +582,7 @@ where
                 &mut crypto_reader,
                 proto_tag,
                 frame_limit,
+                Duration::from_secs(config.timeouts.client_handshake.max(1)),
                 &buffer_pool,
                 &forensics,
                 &mut frame_counter,
@@ -670,6 +672,7 @@ async fn read_client_payload<R>(
     client_reader: &mut CryptoReader<R>,
     proto_tag: ProtoTag,
     max_frame: usize,
+    frame_read_timeout: Duration,
     buffer_pool: &Arc<BufferPool>,
     forensics: &RelayForensicsState,
     frame_counter: &mut u64,
@@ -678,23 +681,40 @@ async fn read_client_payload<R>(
 where
     R: AsyncRead + Unpin + Send + 'static,
 {
+    async fn read_exact_with_timeout<R>(
+        client_reader: &mut CryptoReader<R>,
+        buf: &mut [u8],
+        frame_read_timeout: Duration,
+    ) -> Result<()>
+    where
+        R: AsyncRead + Unpin + Send + 'static,
+    {
+        match timeout(frame_read_timeout, client_reader.read_exact(buf)).await {
+            Ok(Ok(_)) => Ok(()),
+            Ok(Err(e)) => Err(ProxyError::Io(e)),
+            Err(_) => Err(ProxyError::Io(std::io::Error::new(
+                std::io::ErrorKind::TimedOut,
+                "middle-relay client frame read timeout",
+            ))),
+        }
+    }
+
     loop {
         let (len, quickack, raw_len_bytes) = match proto_tag {
             ProtoTag::Abridged => {
                 let mut first = [0u8; 1];
-                match client_reader.read_exact(&mut first).await {
-                    Ok(_) => {}
-                    Err(e) if e.kind() == std::io::ErrorKind::UnexpectedEof => return Ok(None),
-                    Err(e) => return Err(ProxyError::Io(e)),
+                match read_exact_with_timeout(client_reader, &mut first, frame_read_timeout).await {
+                    Ok(()) => {}
+                    Err(ProxyError::Io(e)) if e.kind() == std::io::ErrorKind::UnexpectedEof => {
+                        return Ok(None);
+                    }
+                    Err(e) => return Err(e),
                 }
 
                 let quickack = (first[0] & 0x80) != 0;
                 let len_words = if (first[0] & 0x7f) == 0x7f {
                     let mut ext = [0u8; 3];
-                    client_reader
-                        .read_exact(&mut ext)
-                        .await
-                        .map_err(ProxyError::Io)?;
+                    read_exact_with_timeout(client_reader, &mut ext, frame_read_timeout).await?;
                     u32::from_le_bytes([ext[0], ext[1], ext[2], 0]) as usize
                 } else {
                     (first[0] & 0x7f) as usize
@@ -707,10 +727,12 @@ where
             }
             ProtoTag::Intermediate | ProtoTag::Secure => {
                 let mut len_buf = [0u8; 4];
-                match client_reader.read_exact(&mut len_buf).await {
-                    Ok(_) => {}
-                    Err(e) if e.kind() == std::io::ErrorKind::UnexpectedEof => return Ok(None),
-                    Err(e) => return Err(ProxyError::Io(e)),
+                match read_exact_with_timeout(client_reader, &mut len_buf, frame_read_timeout).await {
+                    Ok(()) => {}
+                    Err(ProxyError::Io(e)) if e.kind() == std::io::ErrorKind::UnexpectedEof => {
+                        return Ok(None);
+                    }
+                    Err(e) => return Err(e),
                 }
                 let quickack = (len_buf[3] & 0x80) != 0;
                 (
@@ -769,10 +791,8 @@ where
             let chunk_len = remaining.min(chunk_cap);
             let mut chunk = buffer_pool.get();
             chunk.resize(chunk_len, 0);
-            client_reader
-                .read_exact(&mut chunk[..chunk_len])
-                .await
-                .map_err(ProxyError::Io)?;
+            read_exact_with_timeout(client_reader, &mut chunk[..chunk_len], frame_read_timeout)
+                .await?;
             payload.extend_from_slice(&chunk[..chunk_len]);
             remaining -= chunk_len;
         }

src/proxy/middle_relay_security_tests.rs

@@ -1,4 +1,12 @@
 use super::*;
+use crate::crypto::AesCtr;
+use crate::stats::Stats;
+use crate::stream::{BufferPool, CryptoReader};
+use std::net::SocketAddr;
+use std::sync::Arc;
+use std::sync::atomic::AtomicU64;
+use tokio::io::AsyncWriteExt;
+use tokio::io::duplex;
 use tokio::time::{Duration as TokioDuration, timeout};
 
 #[test]
@@ -101,3 +109,93 @@ fn desync_dedup_cache_is_bounded() {
         "already tracked key inside dedup window must stay suppressed"
     );
 }
+
+fn make_forensics_state() -> RelayForensicsState {
+    RelayForensicsState {
+        trace_id: 1,
+        conn_id: 2,
+        user: "test-user".to_string(),
+        peer: "127.0.0.1:50000".parse::<SocketAddr>().unwrap(),
+        peer_hash: 3,
+        started_at: Instant::now(),
+        bytes_c2me: 0,
+        bytes_me2c: Arc::new(AtomicU64::new(0)),
+        desync_all_full: false,
+    }
+}
+
+fn make_crypto_reader(reader: tokio::io::DuplexStream) -> CryptoReader<tokio::io::DuplexStream> {
+    let key = [0u8; 32];
+    let iv = 0u128;
+    CryptoReader::new(reader, AesCtr::new(&key, iv))
+}
+
+fn encrypt_for_reader(plaintext: &[u8]) -> Vec<u8> {
+    let key = [0u8; 32];
+    let iv = 0u128;
+    let mut cipher = AesCtr::new(&key, iv);
+    cipher.encrypt(plaintext)
+}
+
+#[tokio::test]
+async fn read_client_payload_times_out_on_header_stall() {
+    let _guard = desync_dedup_test_lock()
+        .lock()
+        .expect("middle relay test lock must be available");
+    let (reader, _writer) = duplex(1024);
+    let mut crypto_reader = make_crypto_reader(reader);
+    let buffer_pool = Arc::new(BufferPool::new());
+    let stats = Stats::new();
+    let forensics = make_forensics_state();
+    let mut frame_counter = 0;
+
+    let result = read_client_payload(
+        &mut crypto_reader,
+        ProtoTag::Intermediate,
+        1024,
+        TokioDuration::from_millis(25),
+        &buffer_pool,
+        &forensics,
+        &mut frame_counter,
+        &stats,
+    )
+    .await;
+
+    assert!(
+        matches!(result, Err(ProxyError::Io(ref e)) if e.kind() == std::io::ErrorKind::TimedOut),
+        "stalled header read must time out"
+    );
+}
+
+#[tokio::test]
+async fn read_client_payload_times_out_on_payload_stall() {
+    let _guard = desync_dedup_test_lock()
+        .lock()
+        .expect("middle relay test lock must be available");
+    let (reader, mut writer) = duplex(1024);
+    let encrypted_len = encrypt_for_reader(&[8, 0, 0, 0]);
+    writer.write_all(&encrypted_len).await.unwrap();
+
+    let mut crypto_reader = make_crypto_reader(reader);
+    let buffer_pool = Arc::new(BufferPool::new());
+    let stats = Stats::new();
+    let forensics = make_forensics_state();
+    let mut frame_counter = 0;
+
+    let result = read_client_payload(
+        &mut crypto_reader,
+        ProtoTag::Intermediate,
+        1024,
+        TokioDuration::from_millis(25),
+        &buffer_pool,
+        &forensics,
+        &mut frame_counter,
+        &stats,
+    )
+    .await;
+
+    assert!(
+        matches!(result, Err(ProxyError::Io(ref e)) if e.kind() == std::io::ErrorKind::TimedOut),
+        "stalled payload body read must time out"
+    );
+}