Refuse to resolve some types of invalid DNS addresses.

net/dns/mock_host_resolver.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/mock_host_resolver.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 95 matching lines @@
                                   AddressList* addresses,
                                   const CompletionCallback& callback,
                                   std::unique_ptr<Request>* request,
                                   const BoundNetLog& net_log) {
   DCHECK(CalledOnValidThread());
   DCHECK(request);
   last_request_priority_ = priority;
   num_resolve_++;
   size_t id = next_request_id_++;
   int rv = ResolveFromIPLiteralOrCache(info, addresses);
-  if (rv != ERR_DNS_CACHE_MISS) {
+  if (rv != ERR_DNS_CACHE_MISS)
     return rv;
-  }
-  if (synchronous_mode_) {
+
+  // Just like the real resolver, refuse to do anything with invalid hostnames.
+  if (!IsValidDNSDomain(info.hostname()))
+    return ERR_NAME_NOT_RESOLVED;
+
+  if (synchronous_mode_)
     return ResolveProc(info, addresses);
-  }
+
   // Store the request for asynchronous resolution
   std::unique_ptr<RequestImpl> req(
       new RequestImpl(info, addresses, callback, this, id));
   requests_[id] = req.get();
   *request = std::move(req);
 
   if (!ondemand_mode_) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE,
         base::Bind(&MockHostResolverBase::ResolveNow, AsWeakPtr(), id));
@@ skipping 342 matching lines @@
   CHECK_EQ(old_proc, current_proc_.get());
 }
 
 void ScopedDefaultHostResolverProc::Init(HostResolverProc* proc) {
   current_proc_ = proc;
   previous_proc_ = HostResolverProc::SetDefault(current_proc_.get());
   current_proc_->SetLastProc(previous_proc_.get());
 }
 
 }  // namespace net