Home | History | Annotate | Download | only in dns
      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 
     13 namespace net {
     14 
     15 class 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).
     19 class 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