From f3cd4d193e76efabef296ac267e13ac33073fb4e Mon Sep 17 00:00:00 2001
From: Juergen Kunz <juergen@foss.global>
Date: Fri, 20 Mar 2026 03:19:57 +0000
Subject: [PATCH] fix(rustproxy-http): prevent HTTP/3 response body streaming
 from hanging on backend completion

---
 changelog.md                                 |  7 +++
 rust/crates/rustproxy-http/src/h3_service.rs | 45 ++++++++++++++++++--
 ts/00_commitinfo_data.ts                     |  2 +-
 3 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/changelog.md b/changelog.md
index 2f9a5ed..e01a218 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## 2026-03-20 - 25.17.4 - fix(rustproxy-http)
+prevent HTTP/3 response body streaming from hanging on backend completion
+
+- extract and track Content-Length before consuming the response body
+- stop the HTTP/3 body loop when the stream reports end-of-stream or the expected byte count has been sent
+- add a per-frame idle timeout to avoid indefinite waits on stalled or close-delimited backend bodies
+
 ## 2026-03-20 - 25.17.3 - fix(repository)
 no changes detected
 
diff --git a/rust/crates/rustproxy-http/src/h3_service.rs b/rust/crates/rustproxy-http/src/h3_service.rs
index 27d60a7..932434c 100644
--- a/rust/crates/rustproxy-http/src/h3_service.rs
+++ b/rust/crates/rustproxy-http/src/h3_service.rs
@@ -259,6 +259,12 @@ async fn handle_h3_request(
         h3_response = h3_response.header(name, value);
     }
 
+    // Extract content-length for body loop termination (must be before into_body())
+    let content_length: Option<u64> = response.headers()
+        .get(hyper::header::CONTENT_LENGTH)
+        .and_then(|v| v.to_str().ok())
+        .and_then(|s| s.parse().ok());
+
     // Add Alt-Svc for HTTP/3 advertisement
     let alt_svc = route.action.udp.as_ref()
         .and_then(|u| u.quic.as_ref())
@@ -279,21 +285,52 @@ async fn handle_h3_request(
 
     // Stream response body back
     use http_body_util::BodyExt;
+    use http_body::Body as _;
     let mut body = response.into_body();
     let mut total_bytes_out: u64 = 0;
-    while let Some(frame) = body.frame().await {
-        match frame {
-            Ok(frame) => {
+
+    // Per-frame idle timeout: if no frame arrives within this duration, assume
+    // the body is complete (or the backend has stalled). This prevents indefinite
+    // hangs on close-delimited bodies or when hyper's internal trailers oneshot
+    // never resolves after all data has been received.
+    const FRAME_IDLE_TIMEOUT: Duration = Duration::from_secs(30);
+
+    loop {
+        // Layer 1: If the body already knows it is finished (Content-Length
+        // bodies track remaining bytes internally), break immediately to
+        // avoid blocking on hyper's internal trailers oneshot.
+        if body.is_end_stream() {
+            break;
+        }
+
+        // Layer 3: Per-frame idle timeout safety net
+        match tokio::time::timeout(FRAME_IDLE_TIMEOUT, body.frame()).await {
+            Ok(Some(Ok(frame))) => {
                 if let Some(data) = frame.data_ref() {
                     total_bytes_out += data.len() as u64;
                     stream.send_data(Bytes::copy_from_slice(data)).await
                         .map_err(|e| anyhow::anyhow!("Failed to send H3 data: {}", e))?;
+
+                    // Layer 2: Content-Length byte count check
+                    if let Some(cl) = content_length {
+                        if total_bytes_out >= cl {
+                            break;
+                        }
+                    }
                 }
             }
-            Err(e) => {
+            Ok(Some(Err(e))) => {
                 warn!("Backend body read error: {}", e);
                 break;
             }
+            Ok(None) => break, // Body ended naturally
+            Err(_) => {
+                debug!(
+                    "H3 body frame idle timeout ({:?}) after {} bytes; finishing stream",
+                    FRAME_IDLE_TIMEOUT, total_bytes_out
+                );
+                break;
+            }
         }
     }
 
diff --git a/ts/00_commitinfo_data.ts b/ts/00_commitinfo_data.ts
index 91fa310..e2a84ac 100644
--- a/ts/00_commitinfo_data.ts
+++ b/ts/00_commitinfo_data.ts
@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartproxy',
-  version: '25.17.3',
+  version: '25.17.4',
   description: 'A powerful proxy package with unified route-based configuration for high traffic management. Features include SSL/TLS support, flexible routing patterns, WebSocket handling, advanced security options, and automatic ACME certificate management.'
 }