Registers socket to receive multicast messages sent to group.
socket must be a gio.types.SocketType.Datagram socket, and must have
been bound to an appropriate interface and port with
gio.socket.Socket.bind.
If iface is null, the system will automatically pick an interface
to bind to based on group.
If source_specific is not null, use source-specific multicast as
defined in RFC 4604. Note that on older platforms this may fail
with a gio.types.IOErrorEnum.NotSupported error.
Note that this function can be called multiple times for the same
group with different source_specific in order to receive multicast
packets from more than one source.
Registers socket to receive multicast messages sent to group. socket must be a gio.types.SocketType.Datagram socket, and must have been bound to an appropriate interface and port with gio.socket.Socket.bind.
If iface is null, the system will automatically pick an interface to bind to based on group.
If source_specific is not null, use source-specific multicast as defined in RFC 4604. Note that on older platforms this may fail with a gio.types.IOErrorEnum.NotSupported error.
Note that this function can be called multiple times for the same group with different source_specific in order to receive multicast packets from more than one source.