Multicast socket API

net/udp/udp_socket_win.h

 // Copyright (c) 2012 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.
 
 #ifndef NET_UDP_UDP_SOCKET_WIN_H_
 #define NET_UDP_UDP_SOCKET_WIN_H_
 
 #include <winsock2.h>
 
 #include "base/memory/ref_counted.h"
@@ skipping 97 matching lines @@
   // Sets corresponding flags in |socket_options_| to allow the socket
   // to share the local address to which the socket will be bound with
   // other processes. Should be called before Bind().
   void AllowAddressReuse();
 
   // Sets corresponding flags in |socket_options_| to allow sending
   // and receiving packets to and from broadcast addresses. Should be
   // called before Bind().
   void AllowBroadcast();
 
+  // Join the multicast group.
+  // |group_address| is the group address to join, could be either
+  // an IPv4 or IPv6 address.
+  // Return a network error code.
+  int JoinGroup(const IPAddressNumber& group_address) const;
+
+  // Leave the multicast group.
+  // |group_address| is the group address to leave, could be either
+  // an IPv4 or IPv6 address. If the socket hasn't joined the group,
+  // it will be ignored.
+  // It's optional to leave the multicast group before destroying
+  // the socket. It will be done by the OS.
+  // Return a network error code.
+  int LeaveGroup(const IPAddressNumber& group_address) const;
+
+  // Set the time-to-live option for UDP packets sent to the multicast
+  // group address. The default value of this option is 1.
+  // Cannot be negative or more than 255.
+  // Should be called before Bind().
+  int SetMulticastTimeToLive(int time_to_live);
+
+  // Set the loopback flag for UDP socket. If this flag is true, the host
+  // will receive packets sent to the joined group from itself.
+  // The default value of this option is true.
+  // Should be called before Bind().
+  //
+  // Note: the behavior of |SetMulticastLoopbackMode| is slightly
+  // different between Windows and Unix-like systems. The inconsistency only
+  // happens when there are more than one applications on the same host
+  // joined to the same multicast group while having different settings on
+  // multicast loopback mode. On Windows, the applications with loopback off
+  // will not RECEIVE the loopback packets; while on Unix-like systems, the
+  // applications with loopback off will not SEND the loopback packets to
+  // other applications on the same host. See MSDN: http://goo.gl/6vqbj
+  int SetMulticastLoopbackMode(bool loopback);
+
  private:
   enum SocketOptions {
-    SOCKET_OPTION_REUSE_ADDRESS = 1 << 0,
-    SOCKET_OPTION_BROADCAST     = 1 << 1
+    SOCKET_OPTION_REUSE_ADDRESS  = 1 << 0,
+    SOCKET_OPTION_BROADCAST      = 1 << 1,
+    SOCKET_OPTION_MULTICAST_LOOP = 1 << 2
   };
 
   class Core;
 
   void DoReadCallback(int rv);
   void DoWriteCallback(int rv);
   void DidCompleteRead();
   void DidCompleteWrite();
 
   // Handles stats and logging. |result| is the number of bytes transferred, on
@@ skipping 21 matching lines @@
   // Bind().
   int SetSocketOptions();
   int DoBind(const IPEndPoint& address);
   int RandomBind(const IPEndPoint& address);
 
   // Attempts to convert the data in |recv_addr_storage_| and |recv_addr_len_|
   // to an IPEndPoint and writes it to |address|. Returns true on success.
   bool ReceiveAddressToIPEndpoint(IPEndPoint* address) const;
 
   SOCKET socket_;
+  int addr_family_;
 
   // Bitwise-or'd combination of SocketOptions. Specifies the set of
   // options that should be applied to |socket_| before Bind().
   int socket_options_;
 
+  // Multicast socket options cached for SetSocketOption.
+  // Cannot be used after Bind().
+  int multicast_time_to_live_;
+
   // How to do source port binding, used only when UDPSocket is part of
   // UDPClientSocket, since UDPServerSocket provides Bind.
   DatagramSocket::BindType bind_type_;
 
   // PRNG function for generating port numbers.
   RandIntCallback rand_int_cb_;
 
   // These are mutable since they're just cached copies to make
   // GetPeerAddress/GetLocalAddress smarter.
   mutable scoped_ptr<IPEndPoint> local_address_;
@@ skipping 17 matching lines @@
   CompletionCallback write_callback_;
 
   BoundNetLog net_log_;
 
   DISALLOW_COPY_AND_ASSIGN(UDPSocketWin);
 };
 
 }  // namespace net
 
 #endif  // NET_UDP_UDP_SOCKET_WIN_H_