Always treat .localhost as loopback

net/dns/dns_transaction.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/dns_transaction.h"
 
 #include <deque>
 #include <string>
 #include <vector>
 
@@ skipping 10 matching lines @@
 #include "base/strings/string_piece.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/timer/timer.h"
 #include "base/values.h"
 #include "net/base/completion_callback.h"
 #include "net/base/dns_util.h"
 #include "net/base/io_buffer.h"
 #include "net/base/ip_endpoint.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_log.h"
+#include "net/base/net_util.h"
 #include "net/dns/dns_protocol.h"
 #include "net/dns/dns_query.h"
 #include "net/dns/dns_response.h"
 #include "net/dns/dns_session.h"
 #include "net/socket/stream_socket.h"
 #include "net/udp/datagram_client_socket.h"
 
 namespace net {
 
 namespace {
@@ skipping 515 matching lines @@
       callback_(callback),
       net_log_(net_log),
       qnames_initial_size_(0),
       attempts_count_(0),
       had_tcp_attempt_(false),
       first_server_index_(0) {
     DCHECK(session_.get());
     DCHECK(!hostname_.empty());
     DCHECK(!callback_.is_null());
     DCHECK(!IsIPLiteral(hostname_));
+
+    // Redirect .localhost queries to localhost to make sure that they are
+    // never sent out on the network, per RFC 6761.
+    if (IsLocalhostTLD(hostname))
+      hostname_ = "localhost";

[Ryan Sleevi, 2015/02/19 22:24:56]

No clue if this is correct; This seems wrong/weird, in as much as GetHostname()
will now return a different name than the input.

[estark, 2015/02/20 01:55:19]

Ah, I see what you mean. I changed it to use localhost in |PrepareSearch|, but
I'm not sure if that's correct either.

   }
 
   ~DnsTransactionImpl() override {
     if (!callback_.is_null()) {
       net_log_.EndEventWithNetErrorCode(NetLog::TYPE_DNS_TRANSACTION,
                                         ERR_ABORTED);
     }  // otherwise logged in DoCallback or Start
   }
 
   const std::string& GetHostname() const override {
@@ skipping 406 matching lines @@
 }  // namespace
 
 // static
 scoped_ptr<DnsTransactionFactory> DnsTransactionFactory::CreateFactory(
     DnsSession* session) {
   return scoped_ptr<DnsTransactionFactory>(
       new DnsTransactionFactoryImpl(session));
 }
 
 }  // namespace net