Harald Welte | aca4edc | 2011-01-21 16:21:12 +0000 | [diff] [blame] | 1 | % |
| 2 | |
| 3 | % (C) 2011 by Harald Welte <laforge@gnumonks.org> |
| 4 | % (C) 2011 OnWaves |
| 5 | % |
| 6 | % All Rights Reserved |
| 7 | % |
| 8 | % This program is free software; you can redistribute it and/or modify |
| 9 | % it under the terms of the GNU Affero General Public License as |
| 10 | % published by the Free Software Foundation; either version 3 of the |
| 11 | % License, or (at your option) any later version. |
| 12 | % |
| 13 | % This program is distributed in the hope that it will be useful, |
| 14 | % but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | % GNU General Public License for more details. |
| 17 | % |
| 18 | % You should have received a copy of the GNU Affero General Public License |
| 19 | % along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 20 | |
| 21 | -module(mgw_nat). |
| 22 | -author("Harald Welte <laforge@gnumonks.org>"). |
| 23 | -export([mangle_rx_data/3]). |
| 24 | |
| 25 | %-include_lib("kernel/include/inet.hrl"). |
| 26 | %-include_lib("kernel/include/inet_sctp.hrl"). |
| 27 | |
| 28 | -include("m2ua.hrl"). |
| 29 | -include("mtp3.hrl"). |
| 30 | -include("isup.hrl"). |
| 31 | -include("sccp.hrl"). |
| 32 | |
| 33 | % mangle the received data |
| 34 | mangle_rx_data(L, From, Data) when is_binary(Data) -> |
| 35 | {ok, M2ua} = m2ua_codec:parse_m2ua_msg(Data), |
| 36 | %io:format("M2UA Decode: ~p~n", [M2ua]), |
| 37 | case M2ua of |
| 38 | #m2ua_msg{msg_class = ?M2UA_MSGC_MAUP, |
| 39 | msg_type = ?M2UA_MAUP_MSGT_DATA} -> |
| 40 | M2ua_out = mangle_rx_m2ua_maup(L, From, M2ua); |
| 41 | #m2ua_msg{} -> |
| 42 | % simply pass it along unmodified |
| 43 | M2ua_out = M2ua |
| 44 | end, |
| 45 | % re-encode the data |
| 46 | %io:format("M2UA Encode: ~p~n", [M2ua_out]), |
| 47 | m2ua_codec:encode_m2ua_msg(M2ua_out). |
| 48 | |
| 49 | % mangle the received M2UA |
| 50 | mangle_rx_m2ua_maup(L, From, M2ua = #m2ua_msg{parameters = Params}) -> |
| 51 | {_Len, M2uaPayload} = proplists:get_value(16#300, Params), |
| 52 | Mtp3 = mtp3_codec:parse_mtp3_msg(M2uaPayload), |
| 53 | %io:format("MTP3 Decode: ~p~n", [Mtp3]), |
| 54 | Mtp3_out = mangle_rx_mtp3(L, From, Mtp3), |
| 55 | %io:format("MTP3 Encode: ~p~n", [Mtp3_out]), |
| 56 | Mtp3OutBin = mtp3_codec:encode_mtp3_msg(Mtp3_out), |
| 57 | Params2 = proplists:delete(16#300, Params), |
| 58 | ParamsNew = Params2 ++ [{16#300, {byte_size(Mtp3OutBin), Mtp3OutBin}}], |
| 59 | % return mangled parsed m2ua msg |
| 60 | M2ua#m2ua_msg{parameters = ParamsNew}. |
| 61 | |
| 62 | % mangle the MTP3 payload |
| 63 | mangle_rx_mtp3(L, From, Mtp3 = #mtp3_msg{service_ind = Service}) -> |
| 64 | mangle_rx_mtp3_serv(L, From, Service, Mtp3). |
| 65 | |
| 66 | % mangle the ISUP content |
| 67 | mangle_rx_mtp3_serv(L, From, ?MTP3_SERV_ISUP, Mtp3 = #mtp3_msg{payload = Payload}) -> |
| 68 | io:format("ISUP In: ~p~n", [Payload]), |
| 69 | Isup = isup_codec:parse_isup_msg(Payload), |
| 70 | io:format("ISUP Decode: ~p~n", [Isup]), |
| 71 | % FIXME |
| 72 | %mangle_rx_isup(From, Isup#isup_msg.msg_type, Isup), |
| 73 | case Isup#isup_msg.msg_type of |
| 74 | ?ISUP_MSGT_IAM -> |
| 75 | io:format("ISUP Encode In: ~p~n", [Isup]), |
| 76 | Isup_out = isup_codec:encode_isup_msg(Isup), |
| 77 | io:format("ISUP Encode Out: ~p~n", [Isup_out]), |
| 78 | % FIXME |
| 79 | if Isup_out == Payload -> ok; |
| 80 | true -> io:format("ISUP DATA NOT EQUAL!~n") |
| 81 | end, |
| 82 | % return modified MTP3 payload |
| 83 | Mtp3#mtp3_msg{payload = Isup_out}; |
| 84 | _ -> |
| 85 | % return UNmodified MTP3 payload |
| 86 | Mtp3 |
| 87 | end; |
| 88 | % mangle the SCCP content |
| 89 | mangle_rx_mtp3_serv(L, From, ?MTP3_SERV_SCCP, Mtp3 = #mtp3_msg{payload = Payload}) -> |
| 90 | Sccp = sccp_codec:parse_sccp_msg(Payload), |
| 91 | io:format("SCCP Decode: ~p~n", [Sccp]), |
| 92 | % FIXME |
| 93 | Mtp3; |
| 94 | % default: do nothing |
| 95 | mangle_rx_mtp3_serv(_L, _From, _, Mtp3) -> |
| 96 | Mtp3. |
| 97 | |
| 98 | -define(MSRN_PFX_MSC, [8,9,0,9,9]). |
| 99 | -define(MSRN_PFX_STP, [9,2,9,9,4,2,0,0]). |
| 100 | |
| 101 | mangle_rx_isup(From, MsgType, Msg = #isup_msg{parameters = Params}) when |
| 102 | MsgType == ?ISUP_MSGT_IAM -> |
| 103 | CalledNum = proplists:get_value(?ISUP_PAR_CALLED_P_NUM, Params), |
| 104 | DigitsIn = CalledNum#party_number.phone_number, |
| 105 | Last2DigF = lists:sublist(DigitsIn, length(DigitsIn)-2, 3), |
| 106 | case From of |
| 107 | from_stp -> |
| 108 | DigitsOut = ?MSRN_PFX_MSC ++ Last2DigF, |
| 109 | io:format("IAM MSRN rewrite (MSC->STP): ~p -> ~p~n", |
| 110 | [DigitsIn, DigitsOut]); |
| 111 | from_msc -> |
| 112 | DigitsOut = DigitsIn, |
| 113 | io:format("No support for MSC->STP MSRN rewrite~n") |
| 114 | end, |
| 115 | CalledNumOut = CalledNum#party_number{phone_number=DigitsOut}, |
| 116 | ParamsDel = proplists:delete(?ISUP_PAR_CALLED_P_NUM, Params), |
| 117 | ParamsOut = [{?ISUP_PAR_CALLED_P_NUM, CalledNumOut}|ParamsDel], |
| 118 | #isup_msg{parameters = ParamsOut}; |
| 119 | % default case: no mangling |
| 120 | mangle_rx_isup(_From, _Type, Msg) when is_record(Msg, isup_msg) -> |
| 121 | Msg. |