Avoid WebSocket upgrade on network error.

net/websockets/websocket_basic_handshake_stream.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/websockets/websocket_basic_handshake_stream.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 #include <string>
@@ skipping 32 matching lines @@
 #include "net/websockets/websocket_handshake_challenge.h"
 #include "net/websockets/websocket_handshake_constants.h"
 #include "net/websockets/websocket_handshake_request_info.h"
 #include "net/websockets/websocket_handshake_response_info.h"
 #include "net/websockets/websocket_stream.h"
 
 namespace net {
 
 namespace {
 
+const char kConnectionErrorStatusLine[] = "HTTP/1.1 503 Connection Error";
+
 // TODO(yhirano): Remove these functions once http://crbug.com/399535 is fixed.
 NOINLINE void RunCallbackWithOk(const CompletionCallback& callback,
                                 int result) {
   DCHECK_EQ(result, OK);
   callback.Run(OK);
 }
 
 NOINLINE void RunCallbackWithInvalidResponseCausedByRedirect(
     const CompletionCallback& callback,
     int result) {
@@ skipping 584 matching lines @@
     }
   } else {
     if (rv == ERR_EMPTY_RESPONSE) {
       set_failure_message(
           "Connection closed before receiving a handshake response");
       return rv;
     }
     set_failure_message(std::string("Error during WebSocket handshake: ") +
                         ErrorToString(rv));
     OnFinishOpeningHandshake();
+    // Some error codes (for example ERR_CONNECTION_CLOSED) get changed to OK at
+    // higher levels. To prevent an unvalidated connection getting erroneously
+    // upgraded, don't pass through the status code unchanged if it is
+    // HTTP_SWITCHING_PROTOCOLS.
+    if (http_response_info_->headers &&
+        http_response_info_->headers->response_code() ==
+            HTTP_SWITCHING_PROTOCOLS)

[yhirano, 2015/02/02 11:06:47]

[optional] This condition is not simple and the action is not short. I do prefer
using curly braces in this case.

[Adam Rice, 2015/02/02 12:10:26]

Done. Thanks.

+      http_response_info_->headers->ReplaceStatusLine(
+          kConnectionErrorStatusLine);
     return rv;
   }
 }
 
 int WebSocketBasicHandshakeStream::ValidateUpgradeResponse(
     const HttpResponseHeaders* headers) {
   extension_params_.reset(new WebSocketExtensionParams);
   std::string failure_message;
   if (ValidateUpgrade(headers, &failure_message) &&
       ValidateSecWebSocketAccept(
@@ skipping 13 matching lines @@
   set_failure_message("Error during WebSocket handshake: " + failure_message);
   return ERR_INVALID_RESPONSE;
 }
 
 void WebSocketBasicHandshakeStream::set_failure_message(
     const std::string& failure_message) {
   *failure_message_ = failure_message;
 }
 
 }  // namespace net