[net/dns] Test IPv6 support via UDP connect

net/dns/host_resolver_impl.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/dns/host_resolver_impl.h"
 
 #if defined(OS_WIN)
 #include <Winsock2.h>
 #elif defined(OS_POSIX)
 #include <netdb.h>
@@ skipping 2036 matching lines @@
   }
 }
 
 HostResolverImpl::Key HostResolverImpl::GetEffectiveKeyForRequest(
     const RequestInfo& info) const {
   HostResolverFlags effective_flags =
       info.host_resolver_flags() | additional_resolver_flags_;
   AddressFamily effective_address_family = info.address_family();
 
   if (info.address_family() == ADDRESS_FAMILY_UNSPECIFIED) {
-    base::TimeTicks start_time = base::TimeTicks::Now();
-    // Google DNS address.
-    const uint8 kIPv6Address[] =
-        { 0x20, 0x01, 0x48, 0x60, 0x48, 0x60, 0x00, 0x00,
-          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x88, 0x88 };
-    bool rv6 = IsGloballyReachable(
-        IPAddressNumber(kIPv6Address, kIPv6Address + arraysize(kIPv6Address)));
+    if (ipv6_probe_monitoring_) {
+      base::TimeTicks start_time = base::TimeTicks::Now();
+      // Google DNS address.
+      const uint8 kIPv6Address[] =
+          { 0x20, 0x01, 0x48, 0x60, 0x48, 0x60, 0x00, 0x00,
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x88, 0x88 };
+      IPAddressNumber address(kIPv6Address,
+                              kIPv6Address + arraysize(kIPv6Address));
+      bool rv6 = IsGloballyReachable(address);
 
-    UMA_HISTOGRAM_TIMES("Net.IPv6ConnectDuration",
-                        base::TimeTicks::Now() - start_time);
-    if (rv6) {
-      UMA_HISTOGRAM_BOOLEAN("Net.IPv6ConnectSuccessMatch",
-          default_address_family_ == ADDRESS_FAMILY_UNSPECIFIED);
+      UMA_HISTOGRAM_TIMES("Net.IPv6ConnectDuration",
+                          base::TimeTicks::Now() - start_time);
+      if (rv6) {
+        UMA_HISTOGRAM_BOOLEAN("Net.IPv6ConnectSuccessMatch",
+            default_address_family_ == ADDRESS_FAMILY_UNSPECIFIED);
+      } else {
+        UMA_HISTOGRAM_BOOLEAN("Net.IPv6ConnectFailureMatch",
+            default_address_family_ != ADDRESS_FAMILY_UNSPECIFIED);
+
+        effective_address_family = ADDRESS_FAMILY_IPV4;
+        effective_flags |= HOST_RESOLVER_DEFAULT_FAMILY_SET_DUE_TO_NO_IPV6;
+      }
     } else {
-      UMA_HISTOGRAM_BOOLEAN("Net.IPv6ConnectFailureMatch",
-          default_address_family_ != ADDRESS_FAMILY_UNSPECIFIED);
+      effective_address_family = default_address_family_;
     }
   }
 
-  if (effective_address_family == ADDRESS_FAMILY_UNSPECIFIED &&
-      default_address_family_ != ADDRESS_FAMILY_UNSPECIFIED) {
-    effective_address_family = default_address_family_;
-    if (ipv6_probe_monitoring_)
-      effective_flags |= HOST_RESOLVER_DEFAULT_FAMILY_SET_DUE_TO_NO_IPV6;
-  }
-
   return Key(info.hostname(), effective_address_family, effective_flags);
 }
 
 void HostResolverImpl::AbortAllInProgressJobs() {
   // In Abort, a Request callback could spawn new Jobs with matching keys, so
   // first collect and remove all running jobs from |jobs_|.
   ScopedVector<Job> jobs_to_abort;
   for (JobMap::iterator it = jobs_.begin(); it != jobs_.end(); ) {
     Job* job = it->second;
     if (job->is_running()) {
@@ skipping 135 matching lines @@
   }
   DnsConfig dns_config;
   NetworkChangeNotifier::GetDnsConfig(&dns_config);
   dns_client_->SetConfig(dns_config);
   num_dns_failures_ = 0;
   if (dns_config.IsValid())
     UMA_HISTOGRAM_BOOLEAN("AsyncDNS.DnsClientEnabled", true);
 }
 
 }  // namespace net