Add int return value to nghttp2_on_frame_recv_callback

lib/includes/nghttp2/nghttp2.h

@@ -779,8 +779,13 @@ typedef ssize_t (*nghttp2_recv_callback)
  *
  * Callback function invoked by `nghttp2_session_recv()` when a
  * non-DATA frame is received.
+ *
+ * The implementation of this function must return 0 if it
+ * succeeds. If nonzero is returned, it is treated as fatal error and
+ * `nghttp2_session_recv()` and `nghttp2_session_send()` functions
+ * return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
  */
-typedef void (*nghttp2_on_frame_recv_callback)
+typedef int (*nghttp2_on_frame_recv_callback)
 (nghttp2_session *session, nghttp2_frame *frame, void *user_data);
 
 /**

lib/nghttp2_session.c

@@ -1567,13 +1567,18 @@ static void nghttp2_session_call_on_request_recv
   }
 }
 
-static void nghttp2_session_call_on_frame_received
+static int nghttp2_session_call_on_frame_received
 (nghttp2_session *session, nghttp2_frame *frame)
 {
+  int rv;
   if(session->callbacks.on_frame_recv_callback) {
-    session->callbacks.on_frame_recv_callback(session, frame,
+    rv = session->callbacks.on_frame_recv_callback(session, frame,
-                                              session->user_data);
+                                                   session->user_data);
+    if(rv != 0) {
+      return NGHTTP2_ERR_CALLBACK_FAILURE;
+    }
   }
+  return 0;
 }
 
 /*
@@ -1709,7 +1714,10 @@ int nghttp2_session_on_request_headers_received(nghttp2_session *session,
     if(flags & NGHTTP2_FLAG_END_STREAM) {
       nghttp2_stream_shutdown(stream, NGHTTP2_SHUT_RD);
     }
-    nghttp2_session_call_on_frame_received(session, frame);
+    r = nghttp2_session_call_on_frame_received(session, frame);
+    if(r != 0) {
+      return r;
+    }
     if(flags & NGHTTP2_FLAG_END_STREAM) {
       nghttp2_session_call_on_request_recv(session, frame->hd.stream_id);
     }
@@ -1723,6 +1731,7 @@ int nghttp2_session_on_response_headers_received(nghttp2_session *session,
                                                  nghttp2_frame *frame,
                                                  nghttp2_stream *stream)
 {
+  int rv;
   /* This function is only called if stream->state ==
      NGHTTP2_STREAM_OPENING and stream_id is local side initiated. */
   assert(stream->state == NGHTTP2_STREAM_OPENING &&
@@ -1738,7 +1747,10 @@ int nghttp2_session_on_response_headers_received(nghttp2_session *session,
   }
   if((stream->shut_flags & NGHTTP2_SHUT_RD) == 0) {
     stream->state = NGHTTP2_STREAM_OPENED;
-    nghttp2_session_call_on_frame_received(session, frame);
+    rv = nghttp2_session_call_on_frame_received(session, frame);
+    if(rv != 0) {
+      return rv;
+    }
     if(frame->hd.flags & NGHTTP2_FLAG_END_STREAM) {
       /* This is the last frame of this stream, so disallow
          further receptions. */
@@ -1783,8 +1795,7 @@ int nghttp2_session_on_push_response_headers_received(nghttp2_session *session,
   }
   nghttp2_stream_promise_fulfilled(stream);
   ++session->num_incoming_streams;
-  nghttp2_session_call_on_frame_received(session, frame);
+  return nghttp2_session_call_on_frame_received(session, frame);
-  return 0;
 }
 
 int nghttp2_session_on_headers_received(nghttp2_session *session,
@@ -1807,7 +1818,10 @@ int nghttp2_session_on_headers_received(nghttp2_session *session,
     if(nghttp2_session_is_my_stream_id(session, frame->hd.stream_id)) {
       if(stream->state == NGHTTP2_STREAM_OPENED) {
         valid = 1;
-        nghttp2_session_call_on_frame_received(session, frame);
+        r = nghttp2_session_call_on_frame_received(session, frame);
+        if(r != 0) {
+          return r;
+        }
         if(frame->hd.flags & NGHTTP2_FLAG_END_STREAM) {
           nghttp2_stream_shutdown(stream, NGHTTP2_SHUT_RD);
           nghttp2_session_close_stream_if_shut_rdwr(session, stream);
@@ -1825,7 +1839,10 @@ int nghttp2_session_on_headers_received(nghttp2_session *session,
          condition. */
       valid = 1;
       if(stream->state != NGHTTP2_STREAM_CLOSING) {
-        nghttp2_session_call_on_frame_received(session, frame);
+        r = nghttp2_session_call_on_frame_received(session, frame);
+        if(r != 0) {
+          return r;
+        }
         if(frame->hd.flags & NGHTTP2_FLAG_END_STREAM) {
           nghttp2_session_call_on_request_recv(session, frame->hd.stream_id);
           nghttp2_stream_shutdown(stream, NGHTTP2_SHUT_RD);
@@ -1858,6 +1875,7 @@ int nghttp2_session_on_headers_received(nghttp2_session *session,
 int nghttp2_session_on_priority_received(nghttp2_session *session,
                                          nghttp2_frame *frame)
 {
+  int rv;
   nghttp2_stream *stream;
   if(frame->hd.stream_id == 0) {
     return nghttp2_session_handle_invalid_connection(session, frame,
@@ -1870,7 +1888,10 @@ int nghttp2_session_on_priority_received(nghttp2_session *session,
       nghttp2_session_reprioritize_stream(session, stream,
                                           frame->priority.pri);
     }
-    nghttp2_session_call_on_frame_received(session, frame);
+    rv = nghttp2_session_call_on_frame_received(session, frame);
+    if(rv != 0) {
+      return rv;
+    }
   }
   return 0;
 }
@@ -1878,11 +1899,15 @@ int nghttp2_session_on_priority_received(nghttp2_session *session,
 int nghttp2_session_on_rst_stream_received(nghttp2_session *session,
                                            nghttp2_frame *frame)
 {
+  int rv;
   if(frame->hd.stream_id == 0) {
     return nghttp2_session_handle_invalid_connection(session, frame,
                                                      NGHTTP2_PROTOCOL_ERROR);
   }
-  nghttp2_session_call_on_frame_received(session, frame);
+  rv = nghttp2_session_call_on_frame_received(session, frame);
+  if(rv != 0) {
+    return rv;
+  }
   nghttp2_session_close_stream(session, frame->hd.stream_id,
                                frame->rst_stream.error_code);
   return 0;
@@ -2167,13 +2192,13 @@ int nghttp2_session_on_settings_received(nghttp2_session *session,
     }
     session->remote_settings[entry->settings_id] = entry->value;
   }
-  nghttp2_session_call_on_frame_received(session, frame);
+  return nghttp2_session_call_on_frame_received(session, frame);
-  return 0;
 }
 
 int nghttp2_session_on_push_promise_received(nghttp2_session *session,
                                              nghttp2_frame *frame)
 {
+  int rv;
   nghttp2_stream *stream;
   if(session->server || frame->hd.stream_id == 0) {
     return nghttp2_session_handle_invalid_connection(session, frame,
@@ -2222,7 +2247,10 @@ int nghttp2_session_on_push_promise_received(nghttp2_session *session,
         if(!promised_stream) {
           return NGHTTP2_ERR_NOMEM;
         }
-        nghttp2_session_call_on_frame_received(session, frame);
+        rv = nghttp2_session_call_on_frame_received(session, frame);
+        if(rv != 0) {
+          return rv;
+        }
       }
     } else {
       if(session->callbacks.on_invalid_frame_recv_callback) {
@@ -2255,9 +2283,11 @@ int nghttp2_session_on_ping_received(nghttp2_session *session,
     /* Peer sent ping, so ping it back */
     r = nghttp2_session_add_ping(session, NGHTTP2_FLAG_PONG,
                                  frame->ping.opaque_data);
+    if(r != 0) {
+      return r;
+    }
   }
-  nghttp2_session_call_on_frame_received(session, frame);
+  return nghttp2_session_call_on_frame_received(session, frame);
-  return r;
 }
 
 int nghttp2_session_on_goaway_received(nghttp2_session *session,
@@ -2265,8 +2295,7 @@ int nghttp2_session_on_goaway_received(nghttp2_session *session,
 {
   session->last_stream_id = frame->goaway.last_stream_id;
   session->goaway_flags |= NGHTTP2_GOAWAY_RECV;
-  nghttp2_session_call_on_frame_received(session, frame);
+  return nghttp2_session_call_on_frame_received(session, frame);
-  return 0;
 }
 
 static int nghttp2_push_back_deferred_data_func(nghttp2_map_entry *entry,
@@ -2307,6 +2336,7 @@ static int nghttp2_session_push_back_deferred_data(nghttp2_session *session)
 int nghttp2_session_on_window_update_received(nghttp2_session *session,
                                               nghttp2_frame *frame)
 {
+  int rv;
   if(frame->hd.stream_id == 0) {
     /* Handle connection-level flow control */
     if(session->remote_flow_control == 0) {
@@ -2314,8 +2344,7 @@ int nghttp2_session_on_window_update_received(nghttp2_session *session,
          WINDOW_UPDATE are asynchronous, so it is hard to determine
          that the peer is misbehaving or not without measuring
          RTT. For now, we just ignore such frames. */
-      nghttp2_session_call_on_frame_received(session, frame);
+      return nghttp2_session_call_on_frame_received(session, frame);
-      return 0;
     }
     if(NGHTTP2_MAX_WINDOW_SIZE - frame->window_update.window_size_increment <
        session->remote_window_size) {
@@ -2323,7 +2352,10 @@ int nghttp2_session_on_window_update_received(nghttp2_session *session,
         (session, frame, NGHTTP2_FLOW_CONTROL_ERROR);
     }
     session->remote_window_size += frame->window_update.window_size_increment;
-    nghttp2_session_call_on_frame_received(session, frame);
+    rv = nghttp2_session_call_on_frame_received(session, frame);
+    if(rv != 0) {
+      return rv;
+    }
     /* To queue the DATA deferred by connection-level flow-control, we
        have to check all streams. Bad. */
     if(session->remote_window_size > 0) {
@@ -2341,8 +2373,7 @@ int nghttp2_session_on_window_update_received(nghttp2_session *session,
       }
       if(stream->remote_flow_control == 0) {
         /* Same reason with connection-level flow control */
-        nghttp2_session_call_on_frame_received(session, frame);
+        return nghttp2_session_call_on_frame_received(session, frame);
-        return 0;
       }
       if(NGHTTP2_MAX_WINDOW_SIZE - frame->window_update.window_size_increment <
          stream->remote_window_size) {
@@ -2368,7 +2399,7 @@ int nghttp2_session_on_window_update_received(nghttp2_session *session,
             return r;
           }
         }
-        nghttp2_session_call_on_frame_received(session, frame);
+        return nghttp2_session_call_on_frame_received(session, frame);
       }
     }
   }

src/HttpServer.cc

@@ -685,7 +685,7 @@ const char *REQUIRED_HEADERS[] = {
 } // namespace
 
 namespace {
-void hd_on_frame_recv_callback
+int hd_on_frame_recv_callback
 (nghttp2_session *session, nghttp2_frame *frame, void *user_data)
 {
   auto hd = reinterpret_cast<Http2Handler*>(user_data);
@@ -701,7 +701,7 @@ void hd_on_frame_recv_callback
       if(!http2::check_http2_headers(frame->headers.nva,
                                      frame->headers.nvlen)) {
         nghttp2_submit_rst_stream(session, stream_id, NGHTTP2_PROTOCOL_ERROR);
-        return;
+        return 0;
       }
       for(size_t i = 0; REQUIRED_HEADERS[i]; ++i) {
         if(!http2::get_unique_header(frame->headers.nva,
@@ -709,7 +709,7 @@ void hd_on_frame_recv_callback
                                      REQUIRED_HEADERS[i])) {
           nghttp2_submit_rst_stream(session, stream_id,
                                     NGHTTP2_PROTOCOL_ERROR);
-          return;
+          return 0;
         }
       }
       auto req = util::make_unique<Request>(stream_id);
@@ -724,6 +724,7 @@ void hd_on_frame_recv_callback
   default:
     break;
   }
+  return 0;
 }
 } // namespace
 

src/app_helper.cc

@@ -323,13 +323,14 @@ void print_frame(print_type ptype, nghttp2_frame *frame)
 }
 } // namespace
 
-void on_frame_recv_callback
+int on_frame_recv_callback
 (nghttp2_session *session, nghttp2_frame *frame, void *user_data)
 {
   print_timer();
   printf(" recv ");
   print_frame(PRINT_RECV, frame);
   fflush(stdout);
+  return 0;
 }
 
 void on_invalid_frame_recv_callback

src/app_helper.h

@@ -39,7 +39,7 @@ namespace nghttp2 {
 
 void print_nv(char **nv);
 
-void on_frame_recv_callback
+int on_frame_recv_callback
 (nghttp2_session *session, nghttp2_frame *frame, void *user_data);
 
 void on_invalid_frame_recv_callback

src/nghttp.cc

@@ -1024,7 +1024,7 @@ void check_response_header
   }
 }
 
-void on_frame_recv_callback2
+int on_frame_recv_callback2
 (nghttp2_session *session, nghttp2_frame *frame, void *user_data)
 {
   if(frame->hd.type == NGHTTP2_HEADERS &&
@@ -1041,6 +1041,7 @@ void on_frame_recv_callback2
   if(config.verbose) {
     on_frame_recv_callback(session, frame, user_data);
   }
+  return 0;
 }
 
 void on_stream_close_callback

src/shrpx_http2_upstream.cc

@@ -173,7 +173,7 @@ int Http2Upstream::upgrade_upstream(HttpsUpstream *http)
 }
 
 namespace {
-void on_frame_recv_callback
+int on_frame_recv_callback
 (nghttp2_session *session, nghttp2_frame *frame, void *user_data)
 {
   auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
@@ -212,7 +212,7 @@ void on_frame_recv_callback
     // Assuming that nva is sorted by name.
     if(!http2::check_http2_headers(nva, nvlen)) {
       upstream->rst_stream(downstream, NGHTTP2_PROTOCOL_ERROR);
-      return;
+      return 0;
     }
 
     for(size_t i = 0; i < nvlen; ++i) {
@@ -233,7 +233,7 @@ void on_frame_recv_callback
        http2::value_lws(method) ||
        (!is_connect && (!scheme || http2::value_lws(scheme)))) {
       upstream->rst_stream(downstream, NGHTTP2_PROTOCOL_ERROR);
-      return;
+      return 0;
     }
     if(!is_connect &&
        (frame->hd.flags & NGHTTP2_FLAG_END_STREAM) == 0) {
@@ -242,7 +242,7 @@ void on_frame_recv_callback
         // If content-length is missing,
         // Downstream::push_upload_data_chunk will fail and
         upstream->rst_stream(downstream, NGHTTP2_PROTOCOL_ERROR);
-        return;
+        return 0;
       }
     }
 
@@ -270,12 +270,12 @@ void on_frame_recv_callback
       // If downstream connection fails, issue RST_STREAM.
       upstream->rst_stream(downstream, NGHTTP2_INTERNAL_ERROR);
       downstream->set_request_state(Downstream::CONNECT_FAIL);
-      return;
+      return 0;
     }
     rv = downstream->push_request_headers();
     if(rv != 0) {
       upstream->rst_stream(downstream, NGHTTP2_INTERNAL_ERROR);
-      return;
+      return 0;
     }
     downstream->set_request_state(Downstream::HEADER_COMPLETE);
     if(frame->hd.flags & NGHTTP2_FLAG_END_STREAM) {
@@ -286,6 +286,7 @@ void on_frame_recv_callback
   default:
     break;
   }
+  return 0;
 }
 } // namespace
 

src/shrpx_spdy_session.cc

@@ -722,7 +722,7 @@ void on_stream_close_callback
 } // namespace
 
 namespace {
-void on_frame_recv_callback
+int on_frame_recv_callback
 (nghttp2_session *session, nghttp2_frame *frame, void *user_data)
 {
   int rv;
@@ -755,7 +755,7 @@ void on_frame_recv_callback
                                 NGHTTP2_PROTOCOL_ERROR);
       downstream->set_response_state(Downstream::MSG_RESET);
       call_downstream_readcb(spdy, downstream);
-      return;
+      return 0;
     }
 
     for(size_t i = 0; i < nvlen; ++i) {
@@ -771,7 +771,7 @@ void on_frame_recv_callback
                                 NGHTTP2_PROTOCOL_ERROR);
       downstream->set_response_state(Downstream::MSG_RESET);
       call_downstream_readcb(spdy, downstream);
-      return;
+      return 0;
     }
     downstream->set_response_http_status
       (strtoul(http2::value_to_str(status).c_str(), nullptr, 10));
@@ -826,7 +826,7 @@ void on_frame_recv_callback
       if(upstream->resume_read(SHRPX_MSG_BLOCK, downstream) != 0) {
         // If resume_read fails, just drop connection. Not ideal.
         delete upstream->get_client_handler();
-        return;
+        return 0;
       }
       downstream->set_request_state(Downstream::HEADER_COMPLETE);
       if(LOG_ENABLED(INFO)) {
@@ -890,6 +890,7 @@ void on_frame_recv_callback
   default:
     break;
   }
+  return 0;
 }
 } // namespace
 

tests/nghttp2_session_test.c

@@ -126,12 +126,13 @@ static ssize_t accumulator_send_callback(nghttp2_session *session,
   return len;
 }
 
-static void on_frame_recv_callback(nghttp2_session *session,
+static int on_frame_recv_callback(nghttp2_session *session,
-                                   nghttp2_frame *frame,
+                                  nghttp2_frame *frame,
-                                   void *user_data)
+                                  void *user_data)
 {
   my_user_data *ud = (my_user_data*)user_data;
   ++ud->frame_recv_cb_called;
+  return 0;
 }
 
 static void on_invalid_frame_recv_callback(nghttp2_session *session,