Add some simplistic MTP3 parsing/encoding functions
diff --git a/src/mtp3.hrl b/src/mtp3.hrl
new file mode 100644
index 0000000..53025a7
--- /dev/null
+++ b/src/mtp3.hrl
@@ -0,0 +1,21 @@
+
+-define(MTP3_SERV_MGMT, 0).
+-define(MTP3_SERV_MTN, 1).
+-define(MTP3_SERV_SCCP, 3).
+-define(MTP3_SERV_TUP, 4).
+-define(MTP3_SERV_ISUP, 5).
+
+-record(mtp3_routing_label, {
+ sig_link_sel,
+ origin_pc,
+ dest_pc
+ }).
+
+-record(mtp3_msg, {
+ network_ind,
+ service_ind,
+ routing_label,
+ payload
+ }).
+
+
diff --git a/src/mtp3_codec.erl b/src/mtp3_codec.erl
new file mode 100644
index 0000000..4912b54
--- /dev/null
+++ b/src/mtp3_codec.erl
@@ -0,0 +1,46 @@
+% ITU-T Q.704 (MTP Level 3) coding / decoding
+
+% (C) 2011 by Harald Welte <laforge@gnumonks.org>
+%
+% All Rights Reserved
+%
+% This program is free software; you can redistribute it and/or modify
+% it under the terms of the GNU Affero General Public License as
+% published by the Free Software Foundation; either version 3 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 Affero General Public License
+% along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+-module(mtp3_codec).
+-author('Harald Welte <laforge@gnumonks.org>').
+-include("mtp3.hrl").
+
+-export([parse_mtp3_msg/1, encode_mtp3_msg/1]).
+
+% Parse standard routing label according to Section 2.2 of ITU-T Q.704
+parse_mtp3_routing_label(_, LabelBin) when is_binary(LabelBin) ->
+ <<Sls:4/big, Opc:14/big, Dpc:14/big, Remain/binary>> = LabelBin,
+ {ok, #mtp3_routing_label{sig_link_sel = Sls, origin_pc = Opc, dest_pc = Dpc}, Remain}.
+
+parse_mtp3_msg(DataBin) when is_binary(DataBin) ->
+ <<NetInd:2, 0:2, ServiceInd:4, Remain/binary>> = DataBin,
+ {ok, RoutLbl, Payload} = parse_mtp3_routing_label(ServiceInd, Remain),
+ #mtp3_msg{network_ind = NetInd, service_ind = ServiceInd, routing_label = RoutLbl,
+ payload = Payload}.
+
+
+encode_mtp3_routing_label(#mtp3_routing_label{sig_link_sel = Sls, origin_pc = Opc,
+ dest_pc = Dpc}) ->
+ <<Sls:4/big, Opc:14/big, Dpc:14/big>>.
+
+encode_mtp3_msg(#mtp3_msg{network_ind = NetInd, service_ind = ServiceInd,
+ routing_label = RoutLbl, payload = Payload}) ->
+ RoutLblBin = encode_mtp3_routing_label(RoutLbl),
+ <<NetInd:2, 0:2, ServiceInd:4, RoutLblBin/binary, Payload/binary>>.
+