Work around linux resolver problem where changes to resolv.conf go unnoticed in some distributions.

net/base/host_resolver.cc

 // Copyright (c) 2006-2008 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/base/host_resolver.h"
 
 #if defined(OS_WIN)
 #include <ws2tcpip.h>
 #include <wspiapi.h>  // Needed for Win2k compat.
 #elif defined(OS_POSIX)
 #include <netdb.h>
 #include <sys/socket.h>
 #endif
+#if defined(OS_LINUX)
+#include <resolv.h>
+#endif
 
 #include "base/message_loop.h"
 #include "base/string_util.h"
 #include "base/worker_pool.h"
 #include "net/base/address_list.h"
 #include "net/base/net_errors.h"
 
 #if defined(OS_WIN)
 #include "net/base/winsock_init.h"
 #endif
@@ skipping 41 matching lines @@
   // See http://crbug.com/5234.
   hints.ai_flags = 0;
 #else
   hints.ai_flags = AI_ADDRCONFIG;
 #endif
 
   // Restrict result set to only this socket type to avoid duplicates.
   hints.ai_socktype = SOCK_STREAM;
 
   int err = getaddrinfo(host.c_str(), port.c_str(), &hints, out);
+#if defined(OS_LINUX)
+  // If we fail, re-initialise the resolver just in case there have been any
+  // changes to /etc/resolv.conf and retry. See http://crbug.com/11380 for info.
+  if (err && !res_init())

[darin (slow to review), 2009/05/27 19:23:11]

please use res_ninit instead, which is threadsafe.

see the mozilla code here:
http://mxr.mozilla.org/seamonkey/source/netwerk/dns/src/nsHostResolver.cpp

+    err = getaddrinfo(host.c_str(), port.c_str(), &hints, out);
+#endif
+
   return err ? ERR_NAME_NOT_RESOLVED : OK;
 }
 
 static int ResolveAddrInfo(HostMapper* mapper, const std::string& host,
                            const std::string& port, struct addrinfo** out) {
   if (mapper) {
     std::string mapped_host = mapper->Map(host);
 
     if (mapped_host.empty())
       return ERR_NAME_NOT_RESOLVED;
@@ skipping 139 matching lines @@
           NewRunnableMethod(request_.get(), &Request::DoLookup), true)) {
     NOTREACHED();
     request_ = NULL;
     return ERR_FAILED;
   }
 
   return ERR_IO_PENDING;
 }
 
 }  // namespace net