1// Copyright (c) 2011 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#ifndef NET_DNS_DNS_QUERY_H_
6#define NET_DNS_DNS_QUERY_H_
7
8#include "base/basictypes.h"
9#include "base/memory/ref_counted.h"
10#include "base/strings/string_piece.h"
11#include "net/base/net_export.h"
12
13namespace net {
14
15class IOBufferWithSize;
16
17// Represents on-the-wire DNS query message as an object.
18// TODO(szym): add support for the OPT pseudo-RR (EDNS0/DNSSEC).
19class NET_EXPORT_PRIVATE DnsQuery {
20 public:
21  // Constructs a query message from |qname| which *MUST* be in a valid
22  // DNS name format, and |qtype|. The qclass is set to IN.
23  DnsQuery(uint16 id, const base::StringPiece& qname, uint16 qtype);
24  ~DnsQuery();
25
26  // Clones |this| verbatim, with ID field of the header set to |id|.
27  DnsQuery* CloneWithNewId(uint16 id) const;
28
29  // DnsQuery field accessors.
30  uint16 id() const;
31  base::StringPiece qname() const;
32  uint16 qtype() const;
33
34  // Returns the Question section of the query.  Used when matching the
35  // response.
36  base::StringPiece question() const;
37
38  // IOBuffer accessor to be used for writing out the query.
39  IOBufferWithSize* io_buffer() const { return io_buffer_.get(); }
40
41  void set_flags(uint16 flags);
42
43 private:
44  DnsQuery(const DnsQuery& orig, uint16 id);
45
46  // Size of the DNS name (*NOT* hostname) we are trying to resolve; used
47  // to calculate offsets.
48  size_t qname_size_;
49
50  // Contains query bytes to be consumed by higher level Write() call.
51  scoped_refptr<IOBufferWithSize> io_buffer_;
52
53  DISALLOW_COPY_AND_ASSIGN(DnsQuery);
54};
55
56}  // namespace net
57
58#endif  // NET_DNS_DNS_QUERY_H_
59