[net/dns] Handle TC bit on DNS response in DnsTransaction.

net/dns/dns_response.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_response.h"
 
 #include "base/string_util.h"
 #include "base/sys_byteorder.h"
 #include "net/base/address_list.h"
 #include "net/base/big_endian.h"
@@ skipping 113 matching lines @@
     cur_ = reader.ptr();
     return true;
   }
   return false;
 }
 
 DnsResponse::DnsResponse()
     : io_buffer_(new IOBufferWithSize(dns_protocol::kMaxUDPSize + 1)) {
 }
 
+DnsResponse::DnsResponse(size_t length)
+    : io_buffer_(new IOBufferWithSize(length)) {
+}
+
 DnsResponse::DnsResponse(const void* data,
                          size_t length,
                          size_t answer_offset)
     : io_buffer_(new IOBufferWithSize(length)),
       parser_(io_buffer_->data(), length, answer_offset) {
   DCHECK(data);
   memcpy(io_buffer_->data(), data, length);
 }
 
 DnsResponse::~DnsResponse() {
 }
 
 bool DnsResponse::InitParse(int nbytes, const DnsQuery& query) {
   // Response includes query, it should be at least that size.
-  if (nbytes < query.io_buffer()->size() || nbytes > dns_protocol::kMaxUDPSize)
+  if (nbytes < query.io_buffer()->size() || nbytes >= io_buffer_->size())
     return false;
 
   // Match the query id.
   if (base::NetToHost16(header()->id) != query.id())
     return false;
 
   // Match question count.
   if (base::NetToHost16(header()->qdcount) != 1)
     return false;
 
@@ skipping 123 matching lines @@
 
   // getcanonname in eglibc returns the first owner name of an A or AAAA RR.
   // If the response passed all the checks so far, then |expected_name| is it.
   *addr_list = AddressList::CreateFromIPAddressList(ip_addresses,
                                                     expected_name);
   *ttl = base::TimeDelta::FromSeconds(ttl_sec);
   return DNS_PARSE_OK;
 }
 
 }  // namespace net