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
10DnsPacketParser::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
23bool 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
40