FTP: Only issue EPSV command for non-IPv4 connections.

net/ftp/ftp_network_transaction.cc

 // Copyright (c) 2012 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/ftp/ftp_network_transaction.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/metrics/histogram.h"
@@ skipping 664 matching lines @@
 }
 
 int FtpNetworkTransaction::DoCtrlConnectComplete(int result) {
   if (result == OK) {
     // Put the peer's IP address and port into the response.
     IPEndPoint ip_endpoint;
     result = ctrl_socket_->GetPeerAddress(&ip_endpoint);
     if (result == OK) {
       response_.socket_address = HostPortPair::FromIPEndPoint(ip_endpoint);
       next_state_ = STATE_CTRL_READ;
+
+      if (ip_endpoint.GetFamily() == AF_INET) {
+        // Do not use EPSV for IPv4 connections. Some servers become confused
+        // and we time out while waiting to connect. PASV is perfectly fine for
+        // IPv4. Note that this blacklists IPv4 not to use EPSV instead of
+        // whitelisting IPv6 to use it, to make the code more future-proof:
+        // all future protocols should just use EPSV.
+        use_epsv_ = false;
+      }
     }
   }
   return result;
 }
 
 int FtpNetworkTransaction::DoCtrlRead() {
   next_state_ = STATE_CTRL_READ_COMPLETE;
   return ctrl_socket_->Read(read_ctrl_buf_, kCtrlBufLen, io_callback_);
 }
 
@@ skipping 683 matching lines @@
   if (!had_error_type[type]) {
     had_error_type[type] = true;
     UMA_HISTOGRAM_ENUMERATION("Net.FtpDataConnectionErrorHappened",
         type, NUM_OF_NET_ERROR_TYPES);
   }
   UMA_HISTOGRAM_ENUMERATION("Net.FtpDataConnectionErrorCount",
       type, NUM_OF_NET_ERROR_TYPES);
 }
 
 }  // namespace net