Revert 39998 - Revert 39996 Refine IPv6 probe to require that the client has...

net/base/host_resolver_impl.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_impl.h"
 
 #include <cmath>
 #include <deque>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/debug_util.h"
 #include "base/lock.h"
 #include "base/message_loop.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
 #include "base/time.h"
 #include "base/worker_pool.h"
 #include "net/base/address_list.h"
 #include "net/base/host_resolver_proc.h"
 #include "net/base/load_log.h"
 #include "net/base/net_errors.h"
+#include "net/base/net_util.h"
 #include "net/base/network_change_notifier.h"
 
 #if defined(OS_WIN)
 #include "net/base/winsock_init.h"
 #endif
 
 namespace net {
 
 namespace {
 
@@ skipping 535 matching lines @@
     HostCache* cache,
     NetworkChangeNotifier* network_change_notifier,
     size_t max_jobs)
     : cache_(cache),
       max_jobs_(max_jobs),
       next_request_id_(0),
       next_job_id_(0),
       resolver_proc_(resolver_proc),
       default_address_family_(ADDRESS_FAMILY_UNSPECIFIED),
       shutdown_(false),
-      network_change_notifier_(network_change_notifier) {
+      network_change_notifier_(network_change_notifier),
+      ipv6_probe_monitoring_(false) {
   DCHECK_GT(max_jobs, 0u);
 
   // It is cumbersome to expose all of the constraints in the constructor,
   // so we choose some defaults, which users can override later.
   job_pools_[POOL_NORMAL] = new JobPool(max_jobs, 100u * max_jobs);
 
 #if defined(OS_WIN)
   EnsureWinsockInit();
 #endif
   if (network_change_notifier_)
@@ skipping 140 matching lines @@
 void HostResolverImpl::RemoveObserver(HostResolver::Observer* observer) {
   ObserversList::iterator it =
       std::find(observers_.begin(), observers_.end(), observer);
 
   // Observer must exist.
   DCHECK(it != observers_.end());
 
   observers_.erase(it);
 }
 
+void HostResolverImpl::SetDefaultAddressFamily(AddressFamily address_family) {
+  ipv6_probe_monitoring_ = false;
+  default_address_family_ = address_family;
+}
+
+void HostResolverImpl::ProbeIPv6Support() {
+  DCHECK(!ipv6_probe_monitoring_);
+  ipv6_probe_monitoring_ = true;
+  OnIPAddressChanged();  // Give initial setup call.
+}
+
 void HostResolverImpl::Shutdown() {
   shutdown_ = true;
 
   // Cancel the outstanding jobs.
   for (JobMap::iterator it = jobs_.begin(); it != jobs_.end(); ++it)
     it->second->Cancel();
   jobs_.clear();
 }
 
 void HostResolverImpl::ClearRequestsTrace() {
@@ skipping 221 matching lines @@
     LoadLog::EndEvent(
         load_log, LoadLog::TYPE_HOST_RESOLVER_IMPL_OBSERVER_ONCANCEL);
   }
 
   LoadLog::EndEvent(load_log, LoadLog::TYPE_HOST_RESOLVER_IMPL);
 }
 
 void HostResolverImpl::OnIPAddressChanged() {
   if (cache_.get())
     cache_->clear();
+  if (ipv6_probe_monitoring_) {
+    bool support = IPv6Supported();
+    default_address_family_ = support ? ADDRESS_FAMILY_UNSPECIFIED
+                                      : ADDRESS_FAMILY_IPV4;
+    LOG(INFO) << "IPv6Probe forced AddressFamily setting to "
+              << (support ? "ADDRESS_FAMILY_UNSPECIFIED"
+                          : "ADDRESS_FAMILY_IPV4");
+  }
 }
 
 // static
 HostResolverImpl::JobPoolIndex HostResolverImpl::GetJobPoolIndexForRequest(
     const Request* req) {
   return POOL_NORMAL;
 }
 
 bool HostResolverImpl::CanCreateJobForPool(const JobPool& pool) const {
   DCHECK_LE(jobs_.size(), max_jobs_);
@@ skipping 67 matching lines @@
     if (r == req)
       return error;
 
     r->OnComplete(error, AddressList());
   }
 
   return ERR_IO_PENDING;
 }
 
 }  // namespace net