Refuse to resolve some types of invalid DNS addresses.

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 1901 matching lines @@
                               AddressList* addresses,
                               const CompletionCallback& callback,
                               std::unique_ptr<Request>* out_req,
                               const BoundNetLog& source_net_log) {
   DCHECK(addresses);
   DCHECK(CalledOnValidThread());
   DCHECK_EQ(false, callback.is_null());
   DCHECK(out_req);
 
   // Check that the caller supplied a valid hostname to resolve.
-  std::string labeled_hostname;
-  if (!DNSDomainFromDot(info.hostname(), &labeled_hostname))
+  if (!IsValidDNSDomain(info.hostname()))
     return ERR_NAME_NOT_RESOLVED;
 
   LogStartRequest(source_net_log, info);
 
   IPAddress ip_address;
   IPAddress* ip_address_ptr = nullptr;
   if (ip_address.AssignFromIPLiteral(info.hostname()))
     ip_address_ptr = &ip_address;
 
   // Build a key that identifies the request in the cache and in the
@@ skipping 674 matching lines @@
   if (job_)
     job_->CancelRequest(this);
 }
 
 void HostResolverImpl::RequestImpl::ChangeRequestPriority(
     RequestPriority priority) {
   job_->ChangeRequestPriority(this, priority);
 }
 
 }  // namespace net