Add int return value to nghttp2_on_data_recv_callback

lib/includes/nghttp2/nghttp2.h

@@ -832,8 +832,13 @@ typedef int (*nghttp2_on_data_chunk_recv_callback)
  * Callback function invoked when DATA frame is received. The actual
  * data it contains are received by
  * :type:`nghttp2_on_data_chunk_recv_callback`.
+ *
+ * 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
+ * immediately return :enum:`NGHTTP2_ERR_CALLBACK_FAILURE`.
  */
-typedef void (*nghttp2_on_data_recv_callback)
+typedef int (*nghttp2_on_data_recv_callback)
 (nghttp2_session *session, uint16_t length, uint8_t flags, int32_t stream_id,
  void *user_data);
 

lib/nghttp2_session.c

@@ -2626,8 +2626,10 @@ int nghttp2_session_on_data_received(nghttp2_session *session,
         if(stream->state == NGHTTP2_STREAM_OPENED) {
           valid = 1;
           if(session->callbacks.on_data_recv_callback) {
-            session->callbacks.on_data_recv_callback
-              (session, length, flags, stream_id, session->user_data);
+            if(session->callbacks.on_data_recv_callback
+               (session, length, flags, stream_id, session->user_data) != 0) {
+              return NGHTTP2_ERR_CALLBACK_FAILURE;
+            }
           }
         } else if(stream->state != NGHTTP2_STREAM_CLOSING) {
           error_code = NGHTTP2_PROTOCOL_ERROR;
@@ -2641,8 +2643,10 @@ int nghttp2_session_on_data_received(nghttp2_session *session,
            NGHTTP2_STREAM_CLOSING state. This is a race condition. */
         valid = 1;
         if(session->callbacks.on_data_recv_callback) {
-          session->callbacks.on_data_recv_callback
-            (session, length, flags, stream_id, session->user_data);
+          if(session->callbacks.on_data_recv_callback
+             (session, length, flags, stream_id, session->user_data) != 0) {
+            return NGHTTP2_ERR_CALLBACK_FAILURE;
+          }
         }
         if(flags & NGHTTP2_FLAG_END_STREAM) {
           nghttp2_session_call_on_request_recv(session, stream_id);

src/HttpServer.cc

@@ -762,7 +762,7 @@ int on_data_chunk_recv_callback
 } // namespace
 
 namespace {
-void hd_on_data_recv_callback
+int hd_on_data_recv_callback
 (nghttp2_session *session, uint16_t length, uint8_t flags, int32_t stream_id,
  void *user_data)
 {
@@ -772,6 +772,7 @@ void hd_on_data_recv_callback
     print_session_id(hd->session_id());
     on_data_recv_callback(session, length, flags, stream_id, user_data);
   }
+  return 0;
 }
 } // namespace
 

src/app_helper.cc

@@ -413,7 +413,7 @@ void print_data_frame(print_type ptype, uint16_t length, uint8_t flags,
 }
 } // namespace
 
-void on_data_recv_callback
+int on_data_recv_callback
 (nghttp2_session *session, uint16_t length, uint8_t flags, int32_t stream_id,
  void *user_data)
 {
@@ -421,6 +421,7 @@ void on_data_recv_callback
   printf(" recv ");
   print_data_frame(PRINT_RECV, length, flags, stream_id);
   fflush(stdout);
+  return 0;
 }
 
 void on_data_send_callback

src/app_helper.h

@@ -64,7 +64,7 @@ void on_unknown_frame_recv_callback(nghttp2_session *session,
 void on_frame_send_callback
 (nghttp2_session *session, nghttp2_frame *frame, void *user_data);
 
-void on_data_recv_callback
+int on_data_recv_callback
 (nghttp2_session *session, uint16_t length, uint8_t flags, int32_t stream_id,
  void *user_data);
 

tests/nghttp2_session_test.c

@@ -175,12 +175,13 @@ static int on_data_chunk_recv_callback(nghttp2_session *session,
   return 0;
 }
 
-static void on_data_recv_callback(nghttp2_session *session,
-                                  uint16_t length, uint8_t flags,
-                                  int32_t stream_id, void *user_data)
+static int on_data_recv_callback(nghttp2_session *session,
+                                 uint16_t length, uint8_t flags,
+                                 int32_t stream_id, void *user_data)
 {
   my_user_data *ud = (my_user_data*)user_data;
   ++ud->data_recv_cb_called;
+  return 0;
 }
 
 static ssize_t fixed_length_data_source_read_callback