nghttpx: Fix backend stall if header and request body are sent in 2 packets

src/shrpx_downstream.cc

@@ -640,7 +640,7 @@ int Downstream::push_request_headers() {
 int Downstream::push_upload_data_chunk(const uint8_t *data, size_t datalen) {
   req_.recv_body_length += datalen;
 
-  if (!request_header_sent_) {
+  if (!dconn_ && !request_header_sent_) {
     blocked_request_buf_.append(data, datalen);
     req_.unconsumed_body_length += datalen;
     return 0;
@@ -662,7 +662,7 @@ int Downstream::push_upload_data_chunk(const uint8_t *data, size_t datalen) {
 }
 
 int Downstream::end_upload_data() {
-  if (!request_header_sent_) {
+  if (!dconn_ && !request_header_sent_) {
     blocked_request_data_eof_ = true;
     return 0;
   }
@@ -1141,6 +1141,10 @@ bool Downstream::get_blocked_request_data_eof() const {
   return blocked_request_data_eof_;
 }
 
+void Downstream::set_blocked_request_data_eof(bool f) {
+  blocked_request_data_eof_ = f;
+}
+
 void Downstream::set_ws_key(const StringRef &key) { ws_key_ = key; }
 
 } // namespace shrpx

src/shrpx_downstream.h

@@ -388,6 +388,7 @@ public:
 
   DefaultMemchunks *get_blocked_request_buf();
   bool get_blocked_request_data_eof() const;
+  void set_blocked_request_data_eof(bool f);
 
   // downstream response API
   const Response &response() const { return resp_; }

src/shrpx_http2_downstream_connection.cc

@@ -499,6 +499,14 @@ int Http2DownstreamConnection::push_request_headers() {
 
 int Http2DownstreamConnection::push_upload_data_chunk(const uint8_t *data,
                                                       size_t datalen) {
+  if (!downstream_->get_request_header_sent()) {
+    auto output = downstream_->get_blocked_request_buf();
+    auto &req = downstream_->request();
+    output->append(data, datalen);
+    req.unconsumed_body_length += datalen;
+    return 0;
+  }
+
   int rv;
   auto output = downstream_->get_request_buf();
   output->append(data, datalen);
@@ -516,6 +524,11 @@ int Http2DownstreamConnection::push_upload_data_chunk(const uint8_t *data,
 }
 
 int Http2DownstreamConnection::end_upload_data() {
+  if (!downstream_->get_request_header_sent()) {
+    downstream_->set_blocked_request_data_eof(true);
+    return 0;
+  }
+
   int rv;
   if (downstream_->get_downstream_stream_id() != -1) {
     rv = http2session_->resume_data(this);

src/shrpx_http_downstream_connection.cc

@@ -705,6 +705,17 @@ int HttpDownstreamConnection::process_blocked_request_buf() {
 
 int HttpDownstreamConnection::push_upload_data_chunk(const uint8_t *data,
                                                      size_t datalen) {
+  if (!downstream_->get_request_header_sent()) {
+    auto output = downstream_->get_blocked_request_buf();
+    auto &req = downstream_->request();
+    output->append(data, datalen);
+    req.unconsumed_body_length += datalen;
+    if (request_header_written_) {
+      signal_write();
+    }
+    return 0;
+  }
+
   auto chunked = downstream_->get_chunked_request();
   auto output = downstream_->get_request_buf();
 
@@ -726,6 +737,14 @@ int HttpDownstreamConnection::push_upload_data_chunk(const uint8_t *data,
 }
 
 int HttpDownstreamConnection::end_upload_data() {
+  if (!downstream_->get_request_header_sent()) {
+    downstream_->set_blocked_request_data_eof(true);
+    if (request_header_written_) {
+      signal_write();
+    }
+    return 0;
+  }
+
   signal_write();
 
   if (!downstream_->get_chunked_request()) {