src/cloud_print/gcp20/prototype/dns_packet_parser.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "cloud_print/gcp20/prototype/dns_packet_parser.h"
   6
   7 #include "base/big_endian.h"
   8 #include "base/logging.h"
   9
  10 DnsPacketParser::DnsPacketParser(const char* packet, size_t length)
  11     : packet_(packet),
  12       length_(length),
  13       record_parser_(packet, length, sizeof(header_)) {
  14   base::BigEndianReader reader(packet, length);
  15   is_header_read_ = reader.ReadU16(&header_.id) &&
  16                     reader.ReadU16(&header_.flags) &&
  17                     reader.ReadU16(&header_.qdcount) &&
  18                     reader.ReadU16(&header_.ancount) &&
  19                     reader.ReadU16(&header_.nscount) &&
  20                     reader.ReadU16(&header_.arcount);
  21 }
  22
  23 bool DnsPacketParser::ReadRecord(DnsQueryRecord* out) {
  24   DCHECK(packet_);
  25   DnsQueryRecord result;
  26   size_t consumed = ReadName(&result.qname);
  27   if (!consumed)
  28     return false;
  29   base::BigEndianReader reader(packet_ + GetOffset() + consumed,
  30                                length_ - (GetOffset() + consumed));
  31   if (reader.ReadU16(&result.qtype) && reader.ReadU16(&result.qclass) &&
  32     record_parser_.SkipQuestion()) {  // instead of |cur_ = reader.ptr();|
  33       *out = result;
  34       return true;
  35   }
  36
  37   return false;
  38 }
  39