Multicast socket API

net/udp/udp_socket_libevent.h

Index: net/udp/udp_socket_libevent.h
diff --git a/net/udp/udp_socket_libevent.h b/net/udp/udp_socket_libevent.h
index ce8a0f2269ad4c39dbe6f8b7e997216ecebde42a..83f78cb461858dc94ba8c4a7b4c582237b37182f 100644
--- a/net/udp/udp_socket_libevent.h
+++ b/net/udp/udp_socket_libevent.h
@@ -5,6 +5,7 @@
 #ifndef NET_UDP_UDP_SOCKET_LIBEVENT_H_
 #define NET_UDP_UDP_SOCKET_LIBEVENT_H_
 
+#include "base/hash_tables.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
@@ -113,6 +114,29 @@ class NET_EXPORT UDPSocketLibevent : public base::NonThreadSafe {
   // called before Bind().
   void AllowBroadcast();
 

[scheib, 2013/04/02 18:25:17]

We should have tests in the /net/ directory. Probably they should have enough
coverage to land the additions to net first, then follow up with extensions
support using it.

+  // Join the multicast group.
+  // |group_address| is the group address to join, could be either
+  // IPv4 or IPv6 address.
+  int JoinGroup(const net::IPAddressNumber& group_address) const;
+
+  // Join the multicast group.

[scheib, 2013/04/02 18:25:17]

Leave ...

[Bei Zhang, 2013/04/05 00:38:59]

Done.

+  // |group_address| is the group address to join, could be either
+  // 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.
+  int LeaveGroup(const net::IPAddressNumber& group_address) const;
+
+  // Set the time-to-live option for udp packets sent to the multicast

[scheib, 2013/04/02 18:25:17]

What unit is this int? seconds? ms?

[Bei Zhang, 2013/04/05 00:38:59]

This is measured by hops. So it's a unitless.

On 2013/04/02 18:25:17, scheib wrote:

+  // group address. Initially this value is 1. Cannot be negative or
+  // more than 255.
+  int SetMulticastTimeToLive(int timeToLive);
+
+  // Set the loopback flag for udp socket. If this flag is true, the host
+  // will receive package sent to the joined group from itself.
+  // Initially this value is true.
+  int SetMulticastLoopbackMode(bool loopback);
+
  private:
   static const int kInvalidSocket = -1;
 
@@ -188,6 +212,7 @@ class NET_EXPORT UDPSocketLibevent : public base::NonThreadSafe {
   int RandomBind(const IPEndPoint& address);
 
   int socket_;
+  int sock_addr_family_;
 
   // Bitwise-or'd combination of SocketOptions. Specifies the set of
   // options that should be applied to |socket_| before Bind().