lib/tuntap/src/eth2udp.erl

   1 %%%----------------------------------------------------------------------
   2 %%% File    : eth2udp.erl
   3 %%% Author  : Luke Gorrie <luke@bluetail.com>
   4 %%% Purpose : Ethernet-over-UDP tunnels
   5 %%% Created : 18 Feb 2003 by Luke Gorrie <luke@bluetail.com>
   6 %%%----------------------------------------------------------------------
   7
   8 -module(eth2udp).
   9 -author('luke@bluetail.com').
  10
  11 -import(lists, [foreach/2]).
  12
  13 -export([start_link/2, start_link/3]).
  14 -export([init/3]).
  15 -export([loop/3]).
  16
  17 %% start_link(Port, [EndPoint]) -> pid()
  18 %%
  19 %% Port = integer() (UDP port for local endpoint)
  20 %% EndPoint = {IP, Port} (UDP endpoint of remote tunnel)
  21 start_link(Port, EPs) ->
  22     start_link(Port, EPs, undefined).
  23 start_link(Port, EPs, Dev) ->
  24     spawn_link(?MODULE, init, [Port, EPs, Dev]).
  25
  26 init(Port, EPs, Dev) ->
  27     {ok, Socket} = gen_udp:open(Port, [binary]),
  28     {ok, Tunnel} = init_tunnel(Dev),
  29     tuntap:set_active(Tunnel, true),
  30     loop(Tunnel, Socket, EPs).
  31
  32 loop(Tunnel, Socket, EPs) ->
  33     receive
  34         {Tunnel, {data, Packet}} ->
  35             io:format("Got ~p byte packet on tap~n", [size(Packet)]),
  36             foreach(fun({IP, Port}) ->
  37                             gen_udp:send(Socket, IP, Port, Packet)
  38                     end,
  39                     EPs);
  40         {udp, Socket, _, _, Packet} ->
  41             io:format("Got ~p byte packet on UDP~n", [size(Packet)]),
  42             tuntap:write(Tunnel, Packet)
  43     end,
  44     ?MODULE:loop(Tunnel, Socket, EPs).
  45
  46 init_tunnel(Dev) ->
  47     Tun = tuntap:open_tuntap(tap, Dev),
  48     Name = tuntap:device_name(Tun),
  49     io:format("Alive and kicking on ~p~n", [Name]),
  50     {ok, Tun}.
  51