ipv6mcast.erl

-module(ipv6mcast).

-compile([export_all]).

-include_lib("eunit/include/eunit.hrl").

%% struct ipv6_mreq {
%%        struct in6_addr ipv6mr_multiaddr; /* IPv6 multicast addr */
%%        unsigned int    ipv6mr_interface; /* interface index */
%%    };

-define(IPPROTO_IPV6,         41).

%% BSD
-define(IPV6_JOIN_GROUP,      12).
-define(IPV6_LEAVE_GROUP,     13).

%% Linux
-define(IPV6_ADD_MEMBERSHIP,  20).
-define(IPV6_DROP_MEMBERSHIP, 21).

ipv6_join_group(BinaryAddress) ->
  case os:type() of
    {unix,darwin} ->
      {raw, ?IPPROTO_IPV6, ?IPV6_JOIN_GROUP, <<BinaryAddress/binary, 0:32/native>>};
    {unix,linux} ->
      {raw, ?IPPROTO_IPV6, ?IPV6_ADD_MEMBERSHIP, <<BinaryAddress/binary, 0:32/native>>}
  end.

ipv6_to_binary(IPv6AddressStr) when is_list(IPv6AddressStr) ->
  {ok, {N1,N2,N3,N4,N5,N6,N7,N8}} = inet_parse:ipv6strict_address(IPv6AddressStr),
  <<N1:16,N2:16,N3:16,N4:16,N5:16,N6:16,N7:16,N8:16>>.

main() ->
  BinaryAddress = ipv6_to_binary("FF02::1"),
  {ok, Socket} = gen_udp:open(9876, [inet6, {active, false},
                                     {raw,
                                      ?IPPROTO_IPV6,
                                      ?IPV6_JOIN_GROUP,
                                      <<BinaryAddress/binary, 0:32/native>>}]),
  {ok, {IP, Port, Binary}} = gen_udp:recv(Socket, 8192),
  ?debugVal(IP),
  ?debugVal(Port),
  ?debugVal(Binary),
  Socket.