Change Cronet's "disable_ipv6" to "disable_ipv6_on_wifi"

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 213 matching lines @@
   const size_t kSuffixLenTrimmed = kSuffixLen - 1;
   if (hostname.back() == '.') {
     return hostname.size() > kSuffixLen &&
         !hostname.compare(hostname.size() - kSuffixLen, kSuffixLen, kSuffix);
   }
   return hostname.size() > kSuffixLenTrimmed &&
       !hostname.compare(hostname.size() - kSuffixLenTrimmed, kSuffixLenTrimmed,
                         kSuffix, kSuffixLenTrimmed);
 }
 
-// Attempts to connect a UDP socket to |dest|:53.
-bool IsGloballyReachable(const IPAddress& dest,
-                         const NetLogWithSource& net_log) {
-  // TODO(eroman): Remove ScopedTracker below once crbug.com/455942 is fixed.
-  tracked_objects::ScopedTracker tracking_profile_1(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION("455942 IsGloballyReachable"));
-
-  std::unique_ptr<DatagramClientSocket> socket(
-      ClientSocketFactory::GetDefaultFactory()->CreateDatagramClientSocket(
-          DatagramSocket::DEFAULT_BIND, RandIntCallback(), net_log.net_log(),
-          net_log.source()));
-  int rv = socket->Connect(IPEndPoint(dest, 53));
-  if (rv != OK)
-    return false;
-  IPEndPoint endpoint;
-  rv = socket->GetLocalAddress(&endpoint);
-  if (rv != OK)
-    return false;
-  DCHECK_EQ(ADDRESS_FAMILY_IPV6, endpoint.GetFamily());
-  const IPAddress& address = endpoint.address();
-
-  bool is_link_local =
-      (address.bytes()[0] == 0xFE) && ((address.bytes()[1] & 0xC0) == 0x80);
-  if (is_link_local)
-    return false;
-
-  const uint8_t kTeredoPrefix[] = {0x20, 0x01, 0, 0};
-  if (IPAddressStartsWith(address, kTeredoPrefix))
-    return false;
-
-  return true;
-}
-
 // Provide a common macro to simplify code and readability. We must use a
 // macro as the underlying HISTOGRAM macro creates static variables.
 #define DNS_HISTOGRAM(name, time) UMA_HISTOGRAM_CUSTOM_TIMES(name, time, \
     base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromHours(1), 100)
 
 // A macro to simplify code and readability.
 #define DNS_HISTOGRAM_BY_PRIORITY(basename, priority, time) \
   do { \
     switch (priority) { \
       case HIGHEST: DNS_HISTOGRAM(basename "_HIGHEST", time); break; \
@@ skipping 1796 matching lines @@
 HostResolverImpl::HostResolverImpl(
     const Options& options,
     NetLog* net_log,
     scoped_refptr<base::TaskRunner> worker_task_runner)
     : max_queued_jobs_(0),
       proc_params_(NULL, options.max_retry_attempts),
       net_log_(net_log),
       received_dns_config_(false),
       num_dns_failures_(0),
       default_address_family_(ADDRESS_FAMILY_UNSPECIFIED),
+      assume_ipv6_failure_on_wifi_(false),
       use_local_ipv6_(false),
       last_ipv6_probe_result_(true),
       resolved_known_ipv6_hostname_(false),
       additional_resolver_flags_(0),
       fallback_to_proctask_(true),
       worker_task_runner_(std::move(worker_task_runner)),
       persist_initialized_(false),
       weak_ptr_factory_(this),
       probe_weak_ptr_factory_(this) {
   if (options.enable_caching)
@@ skipping 164 matching lines @@
 
 void HostResolverImpl::SetDefaultAddressFamily(AddressFamily address_family) {
   DCHECK(CalledOnValidThread());
   default_address_family_ = address_family;
 }
 
 AddressFamily HostResolverImpl::GetDefaultAddressFamily() const {
   return default_address_family_;
 }
 
+void HostResolverImpl::SetNoIPv6OnWifi() {
+  DCHECK(CalledOnValidThread());
+  assume_ipv6_failure_on_wifi_ = true;
+}
+
+bool HostResolverImpl::GetNoIPv6OnWifi() {
+  return assume_ipv6_failure_on_wifi_;
+}
+
 bool HostResolverImpl::ResolveAsIP(const Key& key,
                                    const RequestInfo& info,
                                    const IPAddress* ip_address,
                                    int* net_error,
                                    AddressList* addresses) {
   DCHECK(addresses);
   DCHECK(net_error);
   if (ip_address == nullptr)
     return false;
 
@@ skipping 158 matching lines @@
       // to receiving a IPv6 resolution.
       !use_local_ipv6_ && ip_address == nullptr && !IsIPv6Reachable(net_log)) {
     effective_address_family = ADDRESS_FAMILY_IPV4;
     effective_flags |= HOST_RESOLVER_DEFAULT_FAMILY_SET_DUE_TO_NO_IPV6;
   }
 
   return Key(info.hostname(), effective_address_family, effective_flags);
 }
 
 bool HostResolverImpl::IsIPv6Reachable(const NetLogWithSource& net_log) {
+  // Don't bother checking if we're on wifi and we're assuming that IPv6 doesn't

[pauljensen, 2017/04/13 17:17:01]

nit (and on next line): wifi->WiFi

[pauljensen, 2017/04/13 17:17:01]

nit: I'm not sure which style-guide recommends it, but generally avoiding "I" or
"we" in comments is helpful to make it clear who/what is motivating something.
For example you could reword this line: "Don't bother checking if the device is
on wifi and |assume_ipv6_failure_on_wifi_| indicates that IPv6 doesn't"

[mgersh, 2017/04/13 19:07:20]

Done.

[mgersh, 2017/04/13 19:07:20]

Done.

+  // work on wifi.
+  if (assume_ipv6_failure_on_wifi_ &&
+      NetworkChangeNotifier::GetConnectionType() ==
+          NetworkChangeNotifier::CONNECTION_WIFI) {
+    return false;
+  }
+
   // Cache the result for kIPv6ProbePeriodMs (measured from after
   // IsGloballyReachable() completes).
   bool cached = true;
   if ((base::TimeTicks::Now() - last_ipv6_probe_time_).InMilliseconds() >
       kIPv6ProbePeriodMs) {
     last_ipv6_probe_result_ =
         IsGloballyReachable(IPAddress(kIPv6ProbeAddress), net_log);
     last_ipv6_probe_time_ = base::TimeTicks::Now();
     cached = false;
   }
   net_log.AddEvent(NetLogEventType::HOST_RESOLVER_IMPL_IPV6_REACHABILITY_CHECK,
                    base::Bind(&NetLogIPv6AvailableCallback,
                               last_ipv6_probe_result_, cached));
   return last_ipv6_probe_result_;
 }
 
+bool HostResolverImpl::IsGloballyReachable(const IPAddress& dest,
+                                           const NetLogWithSource& net_log) {
+  // TODO(eroman): Remove ScopedTracker below once crbug.com/455942 is fixed.
+  tracked_objects::ScopedTracker tracking_profile_1(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION("455942 IsGloballyReachable"));
+
+  std::unique_ptr<DatagramClientSocket> socket(
+      ClientSocketFactory::GetDefaultFactory()->CreateDatagramClientSocket(
+          DatagramSocket::DEFAULT_BIND, RandIntCallback(), net_log.net_log(),
+          net_log.source()));
+  int rv = socket->Connect(IPEndPoint(dest, 53));
+  if (rv != OK)
+    return false;
+  IPEndPoint endpoint;
+  rv = socket->GetLocalAddress(&endpoint);
+  if (rv != OK)
+    return false;
+  DCHECK_EQ(ADDRESS_FAMILY_IPV6, endpoint.GetFamily());
+  const IPAddress& address = endpoint.address();
+
+  bool is_link_local =
+      (address.bytes()[0] == 0xFE) && ((address.bytes()[1] & 0xC0) == 0x80);
+  if (is_link_local)
+    return false;
+
+  const uint8_t kTeredoPrefix[] = {0x20, 0x01, 0, 0};
+  if (IPAddressStartsWith(address, kTeredoPrefix))
+    return false;
+
+  return true;
+}
+
 void HostResolverImpl::RunLoopbackProbeJob() {
   new LoopbackProbeJob(weak_ptr_factory_.GetWeakPtr(),
                        worker_task_runner_.get());
 }
 
 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_|.
   std::vector<std::unique_ptr<Job>> jobs_to_abort;
   for (auto it = jobs_.begin(); it != jobs_.end();) {
@@ skipping 247 matching lines @@
   if (job_)
     job_->CancelRequest(this);
 }
 
 void HostResolverImpl::RequestImpl::ChangeRequestPriority(
     RequestPriority priority) {
   job_->ChangeRequestPriority(this, priority);
 }
 
 }  // namespace net