Support replacement of IP address resolutions via command line flag

chrome/browser/io_thread.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 "chrome/browser/io_thread.h"
 
 #include <vector>
 
 #include "base/base64.h"
 #include "base/bind.h"
@@ skipping 30 matching lines @@
 #include "chrome/browser/net/sdch_dictionary_fetcher.h"
 #include "chrome/browser/net/spdyproxy/http_auth_handler_spdyproxy.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "components/policy/core/common/policy_service.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/cookie_store_factory.h"
 #include "net/base/host_mapping_rules.h"
+#include "net/base/ip_mapping_rules.h"
 #include "net/base/net_util.h"
 #include "net/base/network_time_notifier.h"
 #include "net/base/sdch_manager.h"
 #include "net/cert/cert_verifier.h"
 #include "net/cert/ct_known_logs.h"
 #include "net/cert/ct_verifier.h"
 #include "net/cookies/cookie_store.h"
 #include "net/dns/host_cache.h"
 #include "net/dns/host_resolver.h"
 #include "net/dns/mapped_host_resolver.h"
+#include "net/dns/mapped_ip_resolver.h"
 #include "net/ftp/ftp_network_layer.h"
 #include "net/http/http_auth_filter.h"
 #include "net/http/http_auth_handler_factory.h"
 #include "net/http/http_network_layer.h"
 #include "net/http/http_server_properties_impl.h"
 #include "net/proxy/proxy_config_service.h"
 #include "net/proxy/proxy_script_fetcher_impl.h"
 #include "net/proxy/proxy_service.h"
 #include "net/quic/quic_protocol.h"
 #include "net/socket/tcp_client_socket.h"
@@ skipping 112 matching lines @@
 
   // Determine if we should disable IPv6 support.
   if (command_line.HasSwitch(switches::kEnableIPv6)) {
     // Disable IPv6 probing.
     global_host_resolver->SetDefaultAddressFamily(
         net::ADDRESS_FAMILY_UNSPECIFIED);
   } else if (command_line.HasSwitch(switches::kDisableIPv6)) {
     global_host_resolver->SetDefaultAddressFamily(net::ADDRESS_FAMILY_IPV4);
   }
 
-  // If hostname remappings were specified on the command-line, layer these
-  // rules on top of the real host resolver. This allows forwarding all requests
-  // through a designated test server.
-  if (!command_line.HasSwitch(switches::kHostResolverRules))
-    return global_host_resolver.PassAs<net::HostResolver>();
+  // If hostname or IP remappings were specified on the command-line, layer
+  // these rules on top of the real host resolver. Hostname remapping allows
+  // forwarding of all requests to hosts (matching a pattern) through a
+  // designated test server.   IP remapping allows for all IP resolutions that
+  // match a given pattern, such as those destined for a specific CDN, to be
+  // instead directed to a specific/alternate IP address.
+  if (command_line.HasSwitch(switches::kHostResolverRules)) {
+    scoped_ptr<net::MappedHostResolver> remapped_resolver(
+        new net::MappedHostResolver(global_host_resolver.Pass()));
+    remapped_resolver->SetRulesFromString(
+        command_line.GetSwitchValueASCII(switches::kHostResolverRules));
+    global_host_resolver = remapped_resolver.Pass();
+  }
 
-  scoped_ptr<net::MappedHostResolver> remapped_resolver(
-      new net::MappedHostResolver(global_host_resolver.Pass()));
-  remapped_resolver->SetRulesFromString(
-      command_line.GetSwitchValueASCII(switches::kHostResolverRules));
-  return remapped_resolver.PassAs<net::HostResolver>();
+  if (command_line.HasSwitch(switches::kIpResolverRules)) {
+    scoped_ptr<net::MappedIPResolver> remapped_resolver(
+        new net::MappedIPResolver(global_host_resolver.Pass()));
+    remapped_resolver->SetRulesFromString(
+        command_line.GetSwitchValueASCII(switches::kIpResolverRules));
+    global_host_resolver = remapped_resolver.Pass();
+  }
+  return global_host_resolver.Pass();
 }
 
 // TODO(willchan): Remove proxy script fetcher context since it's not necessary
 // now that I got rid of refcounting URLRequestContexts.
 // See IOThread::Globals for details.
 net::URLRequestContext*
 ConstructProxyScriptFetcherContext(IOThread::Globals* globals,
                                    net::NetLog* net_log) {
   net::URLRequestContext* context = new net::URLRequestContext;
   context->set_net_log(net_log);
@@ skipping 977 matching lines @@
   std::string version_flag =
       command_line.GetSwitchValueASCII(switches::kQuicVersion);
   for (size_t i = 0; i < supported_versions.size(); ++i) {
     net::QuicVersion version = supported_versions[i];
     if (net::QuicVersionToString(version) == version_flag) {
       return version;
     }
   }
   return net::QUIC_VERSION_UNSUPPORTED;
 }