net/dns/mdns_client.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 "net/dns/mdns_client.h"
   6
   7 #include "net/base/net_errors.h"
   8 #include "net/dns/dns_protocol.h"
   9 #include "net/dns/mdns_client_impl.h"
  10
  11 namespace net {
  12
  13 namespace {
  14
  15 const char kMDnsMulticastGroupIPv4[] = "224.0.0.251";
  16 const char kMDnsMulticastGroupIPv6[] = "FF02::FB";
  17
  18 IPEndPoint GetMDnsIPEndPoint(const char* address) {
  19   IPAddressNumber multicast_group_number;
  20   bool success = ParseIPLiteralToNumber(address,
  21                                         &multicast_group_number);
  22   DCHECK(success);
  23   return IPEndPoint(multicast_group_number,
  24                     dns_protocol::kDefaultPortMulticast);
  25 }
  26
  27 int Bind(const IPEndPoint& multicast_addr,
  28          uint32 interface_index,
  29          DatagramServerSocket* socket) {
  30   IPAddressNumber address_any(multicast_addr.address().size());
  31   IPEndPoint bind_endpoint(address_any, multicast_addr.port());
  32
  33   socket->AllowAddressReuse();
  34   socket->SetMulticastInterface(interface_index);
  35
  36   int rv = socket->Listen(bind_endpoint);
  37   if (rv < OK)
  38     return rv;
  39
  40   return socket->JoinGroup(multicast_addr.address());
  41 }
  42
  43 }  // namespace
  44
  45 // static
  46 scoped_ptr<MDnsSocketFactory> MDnsSocketFactory::CreateDefault() {
  47   return scoped_ptr<MDnsSocketFactory>(new MDnsSocketFactoryImpl);
  48 }
  49
  50 // static
  51 scoped_ptr<MDnsClient> MDnsClient::CreateDefault() {
  52   return scoped_ptr<MDnsClient>(new MDnsClientImpl());
  53 }
  54
  55 IPEndPoint GetMDnsIPEndPoint(AddressFamily address_family) {
  56   switch (address_family) {
  57     case ADDRESS_FAMILY_IPV4:
  58       return GetMDnsIPEndPoint(kMDnsMulticastGroupIPv4);
  59     case ADDRESS_FAMILY_IPV6:
  60       return GetMDnsIPEndPoint(kMDnsMulticastGroupIPv6);
  61     default:
  62       NOTREACHED();
  63       return IPEndPoint();
  64   }
  65 }
  66
  67 InterfaceIndexFamilyList GetMDnsInterfacesToBind() {
  68   NetworkInterfaceList network_list;
  69   InterfaceIndexFamilyList interfaces;
  70   if (!GetNetworkList(&network_list, INCLUDE_HOST_SCOPE_VIRTUAL_INTERFACES))
  71     return interfaces;
  72   for (size_t i = 0; i < network_list.size(); ++i) {
  73     AddressFamily family = GetAddressFamily(network_list[i].address);
  74     if (family == ADDRESS_FAMILY_IPV4 || family == ADDRESS_FAMILY_IPV6) {
  75       interfaces.push_back(
  76           std::make_pair(network_list[i].interface_index, family));
  77     }
  78   }
  79   std::sort(interfaces.begin(), interfaces.end());
  80   // Interfaces could have multiple addresses. Filter out duplicate entries.
  81   interfaces.erase(std::unique(interfaces.begin(), interfaces.end()),
  82                    interfaces.end());
  83   return interfaces;
  84 }
  85
  86 scoped_ptr<DatagramServerSocket> CreateAndBindMDnsSocket(
  87     AddressFamily address_family,
  88     uint32 interface_index) {
  89   scoped_ptr<DatagramServerSocket> socket(
  90       new UDPServerSocket(NULL, NetLog::Source()));
  91
  92   IPEndPoint multicast_addr = GetMDnsIPEndPoint(address_family);
  93   int rv = Bind(multicast_addr, interface_index, socket.get());
  94   if (rv != OK) {
  95     socket.reset();
  96     VLOG(1) << "Bind failed, endpoint=" << multicast_addr.ToStringWithoutPort()
  97             << ", error=" << rv;
  98   }
  99   return socket.PassAs<DatagramServerSocket>();
 100 }
 101
 102 }  // namespace net