Initial support for built-in DNS resolver/cache.

chrome/browser/io_thread.cc

 // Copyright (c) 2010 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 "chrome/browser/io_thread.h"
 
 #include "base/command_line.h"
 #include "base/debug/leak_tracker.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/stl_util-inl.h"
 #include "base/string_number_conversions.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
 #include "base/thread_restrictions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/gpu_process_host.h"
 #include "chrome/browser/net/chrome_net_log.h"
 #include "chrome/browser/net/connect_interceptor.h"
 #include "chrome/browser/net/passive_log_collector.h"
 #include "chrome/browser/net/predictor_api.h"
 #include "chrome/common/chrome_switches.h"
+#include "chrome/common/net/raw_host_resolver_proc.h"
 #include "chrome/common/net/url_fetcher.h"
 #include "net/base/dnsrr_resolver.h"
 #include "net/base/host_cache.h"
 #include "net/base/host_resolver.h"
 #include "net/base/host_resolver_impl.h"
 #include "net/base/mapped_host_resolver.h"
 #include "net/base/net_util.h"
 #include "net/http/http_auth_filter.h"
 #include "net/http/http_auth_handler_factory.h"
 #if defined(USE_NSS)
@@ skipping 46 matching lines @@
     else if (trial->group() == parallel_8)
       parallelism = 8;
     else if (trial->group() == parallel_10)
       parallelism = 10;
     else if (trial->group() == parallel_14)
       parallelism = 14;
     else if (trial->group() == parallel_20)
       parallelism = 20;
   }
 
+  // Use the specified DNS server for doing raw resolutions if requested
+  // from the command-line.
+  scoped_refptr<net::HostResolverProc> resolver_proc;
+  if (command_line.HasSwitch(switches::kDnsServer)) {
+    std::string dns_ip_string =
+        command_line.GetSwitchValueASCII(switches::kDnsServer);
+    net::IPAddressNumber dns_ip_number;
+    if (net::ParseIPLiteralToNumber(dns_ip_string, &dns_ip_number)) {
+      resolver_proc =
+          new chrome_common_net::RawHostResolverProc(dns_ip_number, NULL);
+    } else {
+      LOG(ERROR) << "Invalid IP address specified for --dns-server: "
+                 << dns_ip_string;
+    }
+  }
+
   net::HostResolver* global_host_resolver =
-      net::CreateSystemHostResolver(parallelism, net_log);
+      net::CreateSystemHostResolver(parallelism, resolver_proc.get(), net_log);
 
   // Determine if we should disable IPv6 support.
   if (!command_line.HasSwitch(switches::kEnableIPv6)) {
     if (command_line.HasSwitch(switches::kDisableIPv6)) {
       global_host_resolver->SetDefaultAddressFamily(net::ADDRESS_FAMILY_IPV4);
     } else {
       net::HostResolverImpl* host_resolver_impl =
           global_host_resolver->GetAsHostResolverImpl();
       if (host_resolver_impl != NULL) {
         // Use probe to decide if support is warranted.
@@ skipping 309 matching lines @@
     net::HostCache* host_cache =
         globals_->host_resolver.get()->GetAsHostResolverImpl()->cache();
     if (host_cache)
       host_cache->clear();
   }
   // Clear all of the passively logged data.
   // TODO(eroman): this is a bit heavy handed, really all we need to do is
   //               clear the data pertaining to off the record context.
   globals_->net_log->passive_collector()->Clear();
 }