Multicast DNS implementation (initial)

net/dns/mdns_query.cc

+// Copyright (c) 2013 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/mdns_query.h"
+
+#include "base/sys_byteorder.h"
+#include "net/base/big_endian.h"
+#include "net/base/dns_util.h"
+#include "net/dns/dns_protocol.h"
+
+namespace net {
+
+MDnsQuery::MDnsQuery(const base::StringPiece& qname, uint16 qtype) {
+  DCHECK(!DNSDomainToString(qname).empty());
+
+  // QNAME + QTYPE + QCLASS
+  size_t question_size = qname.size() + sizeof(uint16) + sizeof(uint16);
+  io_buffer_ = new IOBufferWithSize(sizeof(dns_protocol::Header) +
+                                    question_size);
+  dns_protocol::Header* header =
+      reinterpret_cast<dns_protocol::Header*>(io_buffer_->data());
+  memset(header, 0, sizeof(dns_protocol::Header));
+  // Do not set ID or flags.
+  header->qdcount = base::HostToNet16(1);
+
+  // Write question section after the header.
+  BigEndianWriter writer(reinterpret_cast<char*>(header + 1), question_size);
+  writer.WriteBytes(qname.data(), qname.size());
+  writer.WriteU16(qtype);
+  writer.WriteU16(dns_protocol::kClassIN);
+}
+
+MDnsQuery::~MDnsQuery() {
+}
+}