25
1
mirror of https://github.com/processone/ejabberd.git synced 2024-10-29 15:12:12 +01:00
xmpp.chapril.org-ejabberd/src/stun/stun_codec.erl

344 lines
10 KiB
Erlang
Raw Normal View History

%%%-------------------------------------------------------------------
%%% File : stun_codec.erl
%%% Author : Evgeniy Khramtsov <ekhramtsov@process-one.net>
%%% Description : STUN codec
%%% Created : 7 Aug 2009 by Evgeniy Khramtsov <ekhramtsov@process-one.net>
%%%
%%%
2011-02-14 13:50:55 +01:00
%%% ejabberd, Copyright (C) 2002-2011 ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License
%%% along with this program; if not, write to the Free Software
%%% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
%%% 02111-1307 USA
%%%
%%%-------------------------------------------------------------------
-module(stun_codec).
%% API
-export([decode/1,
encode/1,
version/1,
reason/1,
pp/1]).
%% Tests
-export([test_udp/2,
test_tcp/2,
test_tls/2,
test_public/0]).
-include("stun.hrl").
%%====================================================================
%% API
%%====================================================================
decode(<<0:2, Type:14, Len:16, Magic:32, TrID:96,
Body:Len/binary, Tail/binary>>) ->
case catch decode(Type, Magic, TrID, Body) of
{'EXIT', _} ->
{error, unparsed};
Res ->
{ok, Res, Tail}
end;
decode(<<0:2, _/binary>>) ->
more;
decode(<<>>) ->
empty;
decode(_) ->
{error, unparsed}.
encode(#stun{class = Class,
method = Method,
magic = Magic,
trid = TrID} = Msg) ->
ClassCode = case Class of
request -> 0;
indication -> 1;
response -> 2;
error -> 3
end,
Type = ?STUN_TYPE(ClassCode, Method),
Attrs = enc_attrs(Msg),
Len = size(Attrs),
<<0:2, Type:14, Len:16, Magic:32, TrID:96, Attrs/binary>>.
pp(Term) ->
io_lib_pretty:print(Term, fun pp/2).
version(#stun{magic = ?STUN_MAGIC}) ->
new;
version(#stun{}) ->
old.
reason(300) -> <<"Try Alternate">>;
reason(400) -> <<"Bad Request">>;
reason(401) -> <<"Unauthorized">>;
reason(420) -> <<"Unknown Attribute">>;
reason(438) -> <<"Stale Nonce">>;
reason(500) -> <<"Server Error">>;
reason(_) -> <<"Undefined Error">>.
%%====================================================================
%% Internal functions
%%====================================================================
decode(Type, Magic, TrID, Body) ->
Method = ?STUN_METHOD(Type),
Class = case ?STUN_CLASS(Type) of
0 -> request;
1 -> indication;
2 -> response;
3 -> error
end,
dec_attrs(Body, #stun{class = Class,
method = Method,
magic = Magic,
trid = TrID}).
dec_attrs(<<Type:16, Len:16, Rest/binary>>, Msg) ->
PaddLen = padd_len(Len),
<<Val:Len/binary, _:PaddLen, Tail/binary>> = Rest,
NewMsg = dec_attr(Type, Val, Msg),
if Type == ?STUN_ATTR_MESSAGE_INTEGRITY ->
NewMsg;
true ->
dec_attrs(Tail, NewMsg)
end;
dec_attrs(<<>>, Msg) ->
Msg.
enc_attrs(Msg) ->
list_to_binary(
[enc_attr(?STUN_ATTR_SOFTWARE, Msg#stun.'SOFTWARE'),
enc_addr(?STUN_ATTR_MAPPED_ADDRESS, Msg#stun.'MAPPED-ADDRESS'),
enc_xor_addr(?STUN_ATTR_XOR_MAPPED_ADDRESS,
Msg#stun.magic, Msg#stun.trid,
Msg#stun.'XOR-MAPPED-ADDRESS'),
enc_addr(?STUN_ATTR_ALTERNATE_SERVER, Msg#stun.'ALTERNATE-SERVER'),
enc_attr(?STUN_ATTR_USERNAME, Msg#stun.'USERNAME'),
enc_attr(?STUN_ATTR_REALM, Msg#stun.'REALM'),
enc_attr(?STUN_ATTR_NONCE, Msg#stun.'NONCE'),
enc_error_code(Msg#stun.'ERROR-CODE'),
enc_unknown_attrs(Msg#stun.'UNKNOWN-ATTRIBUTES')]).
dec_attr(?STUN_ATTR_MAPPED_ADDRESS, Val, Msg) ->
<<_, Family, Port:16, AddrBin/binary>> = Val,
Addr = dec_addr(Family, AddrBin),
Msg#stun{'MAPPED-ADDRESS' = {Addr, Port}};
dec_attr(?STUN_ATTR_XOR_MAPPED_ADDRESS, Val, Msg) ->
<<_, Family, XPort:16, XAddr/binary>> = Val,
Magic = Msg#stun.magic,
Port = XPort bxor (Magic bsr 16),
Addr = dec_xor_addr(Family, Magic, Msg#stun.trid, XAddr),
Msg#stun{'XOR-MAPPED-ADDRESS' = {Addr, Port}};
dec_attr(?STUN_ATTR_SOFTWARE, Val, Msg) ->
Msg#stun{'SOFTWARE' = Val};
dec_attr(?STUN_ATTR_USERNAME, Val, Msg) ->
Msg#stun{'USERNAME' = Val};
dec_attr(?STUN_ATTR_REALM, Val, Msg) ->
Msg#stun{'REALM' = Val};
dec_attr(?STUN_ATTR_NONCE, Val, Msg) ->
Msg#stun{'NONCE' = Val};
dec_attr(?STUN_ATTR_MESSAGE_INTEGRITY, Val, Msg) ->
Msg#stun{'MESSAGE-INTEGRITY' = Val};
dec_attr(?STUN_ATTR_ALTERNATE_SERVER, Val, Msg) ->
<<_, Family, Port:16, Address/binary>> = Val,
IP = dec_addr(Family, Address),
Msg#stun{'ALTERNATE-SERVER' = {IP, Port}};
dec_attr(?STUN_ATTR_ERROR_CODE, Val, Msg) ->
<<_:21, Class:3, Number:8, Reason/binary>> = Val,
if Class >=3, Class =< 6, Number >=0, Number =< 99 ->
Code = Class * 100 + Number,
Msg#stun{'ERROR-CODE' = {Code, Reason}}
end;
dec_attr(?STUN_ATTR_UNKNOWN_ATTRIBUTES, Val, Msg) ->
Attrs = dec_unknown_attrs(Val, []),
Msg#stun{'UNKNOWN-ATTRIBUTES' = Attrs};
dec_attr(Attr, _Val, #stun{unsupported = Attrs} = Msg)
when Attr =< 16#7fff ->
Msg#stun{unsupported = [Attr|Attrs]};
dec_attr(_Attr, _Val, Msg) ->
Msg.
dec_addr(1, <<A1, A2, A3, A4>>) ->
{A1, A2, A3, A4};
dec_addr(2, <<A1:16, A2:16, A3:16, A4:16,
A5:16, A6:16, A7:16, A8:16>>) ->
{A1, A2, A3, A4, A5, A6, A7, A8}.
dec_xor_addr(1, Magic, _TrID, <<XAddr:32>>) ->
Addr = XAddr bxor Magic,
dec_addr(1, <<Addr:32>>);
dec_xor_addr(2, Magic, TrID, <<XAddr:128>>) ->
Addr = XAddr bxor ((Magic bsl 96) bor TrID),
dec_addr(2, <<Addr:128>>).
dec_unknown_attrs(<<Attr:16, Tail/binary>>, Acc) ->
dec_unknown_attrs(Tail, [Attr|Acc]);
dec_unknown_attrs(<<>>, Acc) ->
lists:reverse(Acc).
enc_attr(_Attr, undefined) ->
<<>>;
enc_attr(Attr, Val) ->
Len = size(Val),
PaddLen = padd_len(Len),
<<Attr:16, Len:16, Val/binary, 0:PaddLen>>.
enc_addr(_Type, undefined) ->
<<>>;
enc_addr(Type, {{A1, A2, A3, A4}, Port}) ->
enc_attr(Type, <<0, 1, Port:16, A1, A2, A3, A4>>);
enc_addr(Type, {{A1, A2, A3, A4, A5, A6, A7, A8}, Port}) ->
enc_attr(Type, <<0, 2, Port:16, A1:16, A2:16, A3:16,
A4:16, A5:16, A6:16, A7:16, A8:16>>).
enc_xor_addr(_Type, _Magic, _TrID, undefined) ->
<<>>;
enc_xor_addr(Type, Magic, _TrID, {{A1, A2, A3, A4}, Port}) ->
XPort = Port bxor (Magic bsr 16),
<<Addr:32>> = <<A1, A2, A3, A4>>,
XAddr = Addr bxor Magic,
enc_attr(Type, <<0, 1, XPort:16, XAddr:32>>);
enc_xor_addr(Type, Magic, TrID,
{{A1, A2, A3, A4, A5, A6, A7, A8}, Port}) ->
XPort = Port bxor (Magic bsr 16),
<<Addr:128>> = <<A1:16, A2:16, A3:16, A4:16,
A5:16, A6:16, A7:16, A8:16>>,
XAddr = Addr bxor ((Magic bsl 96) bor TrID),
enc_attr(Type, <<0, 2, XPort:16, XAddr:128>>).
enc_error_code(undefined) ->
<<>>;
enc_error_code({Code, Reason}) ->
Class = Code div 100,
Number = Code rem 100,
enc_attr(?STUN_ATTR_ERROR_CODE,
<<0:21, Class:3, Number:8, Reason/binary>>).
enc_unknown_attrs([]) ->
<<>>;
enc_unknown_attrs(Attrs) ->
enc_attr(?STUN_ATTR_UNKNOWN_ATTRIBUTES,
list_to_binary([<<Attr:16>> || Attr <- Attrs])).
%%====================================================================
%% Auxiliary functions
%%====================================================================
pp(Tag, N) ->
try
pp1(Tag, N)
catch _:_ ->
no
end.
pp1(stun, N) ->
N = record_info(size, stun) - 1,
record_info(fields, stun);
pp1(_, _) ->
no.
%% Workaround for stupid clients.
-ifdef(NO_PADDING).
padd_len(_Len) ->
0.
-else.
padd_len(Len) ->
case Len rem 4 of
0 -> 0;
N -> 8*(4-N)
end.
-endif.
%%====================================================================
%% Test functions
%%====================================================================
bind_msg() ->
Msg = #stun{method = ?STUN_METHOD_BINDING,
class = request,
trid = random:uniform(1 bsl 96),
'SOFTWARE' = <<"test">>},
encode(Msg).
test_udp(Addr, Port) ->
test(Addr, Port, gen_udp).
test_tcp(Addr, Port) ->
test(Addr, Port, gen_tcp).
test_tls(Addr, Port) ->
test(Addr, Port, ssl).
test(Addr, Port, Mod) ->
Res = case Mod of
gen_udp ->
Mod:open(0, [binary, {active, false}]);
_ ->
Mod:connect(Addr, Port,
[binary, {active, false}], 1000)
end,
case Res of
{ok, Sock} ->
if Mod == gen_udp ->
Mod:send(Sock, Addr, Port, bind_msg());
true ->
Mod:send(Sock, bind_msg())
end,
case Mod:recv(Sock, 0, 1000) of
{ok, {_, _, Data}} ->
try_dec(Data);
{ok, Data} ->
try_dec(Data);
Err ->
io:format("err: ~p~n", [Err])
end,
Mod:close(Sock);
Err ->
io:format("err: ~p~n", [Err])
end.
try_dec(Data) ->
case decode(Data) of
{ok, Msg, _} ->
io:format("got:~n~s~n", [pp(Msg)]);
Err ->
io:format("err: ~p~n", [Err])
end.
public_servers() ->
[{"stun.ekiga.net", 3478, 3478, 5349},
{"stun.fwdnet.net", 3478, 3478, 5349},
{"stun.ideasip.com", 3478, 3478, 5349},
{"stun01.sipphone.com", 3478, 3478, 5349},
{"stun.softjoys.com", 3478, 3478, 5349},
{"stun.voipbuster.com", 3478, 3478, 5349},
{"stun.voxgratia.org", 3478, 3478, 5349},
{"stun.xten.com", 3478, 3478, 5349},
{"stunserver.org", 3478, 3478, 5349},
{"stun.sipgate.net", 10000, 10000, 5349},
{"numb.viagenie.ca", 3478, 3478, 5349},
{"stun.ipshka.com", 3478, 3478, 5349},
{"localhost", 3478, 5349, 5349}].
test_public() ->
ssl:start(),
lists:foreach(
fun({Addr, UDPPort, TCPPort, TLSPort}) ->
io:format("trying ~s:~p on UDP... ", [Addr, UDPPort]),
test_udp(Addr, UDPPort),
io:format("trying ~s:~p on TCP... ", [Addr, TCPPort]),
test_tcp(Addr, TCPPort),
io:format("trying ~s:~p on TLS... ", [Addr, TLSPort]),
test_tls(Addr, TLSPort)
end, public_servers()).