Add multicast support to DatagramServerSocket

net/udp/datagram_server_socket.h

Index: net/udp/datagram_server_socket.h
diff --git a/net/udp/datagram_server_socket.h b/net/udp/datagram_server_socket.h
index a1aa38bdefff72a8a24f7c2e263ade0b3b55af73..67120fee8806cada8336f1fe054ef080e81c7418 100644
--- a/net/udp/datagram_server_socket.h
+++ b/net/udp/datagram_server_socket.h
@@ -6,6 +6,7 @@
 #define NET_UDP_DATAGRAM_SERVER_SOCKET_H_
 
 #include "net/base/completion_callback.h"
+#include "net/base/net_util.h"
 #include "net/udp/datagram_socket.h"
 
 namespace net {
@@ -67,6 +68,35 @@ class NET_EXPORT DatagramServerSocket : public DatagramSocket {
   // Allow sending and receiving packets to and from broadcast addresses.
   // Should be called before Listen().
   virtual void AllowBroadcast() = 0;
+
+  // Join the multicast group.
+  // |group_address| is the group address to join, could be either

[Sergey Ulanov, 2013/06/07 19:59:38]

nit: Suggest rephrasing: "Join multicast group with the specified
|group_address|."
I don't think you need to mention IPv6.

+  // an IPv4 or IPv6 address.
+  // Return a network error code.

[Sergey Ulanov, 2013/06/07 19:59:38]

nit: s/Return/Returns/, here and below.

+  virtual int JoinGroup(const IPAddressNumber& group_address) const = 0;
+
+  // Leave the multicast group.
+  // |group_address| is the group address to leave, could be either

[Sergey Ulanov, 2013/06/07 19:59:38]

Repharase similar to JoinGroup() please.

+  // 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.
+  virtual int LeaveGroup(const IPAddressNumber& group_address) const = 0;
+
+  // 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().
+  // Return a network error code.
+  virtual int SetMulticastTimeToLive(int time_to_live) = 0;
+
+  // 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().
+  // Return a network error code.
+  virtual int SetMulticastLoopbackMode(bool loopback) = 0;
 };
 
 }  // namespace net