add 'tcap_helper' module for unit testing or shell use

This module permits simple generation of common TCAP messages.

ebin/osmo_map.app

@@ -1,7 +1,8 @@
 {application, osmo_map,
 	[{description, "Osmocom SS7 MAP"},
 	 {vsn, "1"},
-	 {modules, [map, map_codec, tcap_asn]},
+	 {modules, [map, map_codec,
+		    tcap_asn, tcap_helper]},
 	 {registered, []},
 	 {applications, []},
 	 {env, [

src/tcap_helper.erl

@@ -0,0 +1,121 @@
+% TCAP codec helper functions for test scripts and the like
+
+% (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(tcap_helper).
+-author('Harald Welte <laforge@gnumonks.org>').
+
+-include("tcap_asn.hrl").
+
+-export([build_inv_comp/3, build_inv_comp/4,
+	 build_retres_comp/2, build_retreslast_comp/2, build_retreslast_comp/1,
+	 enc_component/1,
+	 build_begin/4, build_begin/3, build_end/3,
+	 build_inv_begin/5, build_retresl_end/4
+ 	]).
+
+format_id(undefined) ->
+	asn1_NOVALUE;
+format_id(Int) when is_integer(Int) ->
+	{present, Int}.
+
+process_uint32(Int) when is_integer(Int) ->
+	<<Int:32/big>>;
+process_uint32(Int) when is_list(Int); is_binary(Int) ->
+	Int.
+
+process_undefined(undefined) ->
+	asn1_NOVALUE;
+process_undefined(Other) ->
+	Other.
+
+
+% build a decoded Invoke component
+build_inv_comp(InvIdIn, Opcode, Argument, LinkedIdIn) ->
+	InvId = format_id(InvIdIn),
+	LinkedId = format_id(LinkedIdIn),
+	{invoke, #'Invoke'{invokeId = InvId, linkedId = LinkedId,
+				opcode = {local, Opcode},
+				argument = Argument}}.
+build_inv_comp(InvIdIn, Opcode, Argument) ->
+	build_inv_comp(InvIdIn, Opcode, Argument, undefined).
+
+% build a BER-encoded ReturnResult component
+build_retres_comp(InvIdIn, Data) ->
+	InvId = format_id(InvIdIn),
+	{resurnResult, #'ReturnResult'{invokeId = InvId, result = Data}}.
+
+% build a BER-encoded ReturnResultLast component
+build_retreslast_comp(InvIdIn, Data) ->
+	InvId = format_id(InvIdIn),
+	{returnResultLast, #'ReturnResult'{invokeId = InvId, result = Data}}.
+build_retreslast_comp(InvIdIn) ->
+	build_retreslast_comp(InvIdIn, asn1_NOVALUE).
+
+% helper function for BER encoding a Component
+enc_component(Comp) ->
+	{ok, Ret} = tcap_asn:encode('Component', Comp),
+	Ret.
+
+% helper function for BER-encoding the DialoguePDU and wrapping it in 'EXTERNAL' type
+enc_dialg_ext(Dpdu) ->
+	{ok, DpduEnc} = tcap_asn:encode('DialoguePDU', Dpdu),
+	ExtPdu = #'EXTERNAL'{'direct-reference' = {0,0,17,773,1,1,1},
+			     'encoding' = {'single-ASN1-type', DpduEnc}},
+	ExtPdu.
+
+% Build a binary-encoded 'Begin' DialoguePortion message with specified components
+build_begin(OtidIn, ACname, ComponentsIn) ->
+	build_begin(OtidIn, ACname, asn1_NOVALUE, ComponentsIn).
+build_begin(OtidIn, ACname, UserDlgInfoIn, ComponentsIn) ->
+	Otid = process_uint32(OtidIn),
+	UserDlgInfo = process_undefined(UserDlgInfoIn),
+	Dpdu = {dialogueRequest, #'AARQ-apdu'{'protocol-version' = [version1],
+					      'application-context-name' = ACname,
+					      'user-information' = UserDlgInfo}},
+	ExtPdu = enc_dialg_ext(Dpdu),
+	{ok, EncComponents} = tcap_asn:encode('Components', ComponentsIn),
+	Msg={'begin', #'Begin'{otid = Otid, dialoguePortion = ExtPdu, components = EncComponents}},
+	enc_msg(Msg).
+
+% Build a binary-encoded 'End' DialoguePortion message with specified components
+build_end(DtidIn, ACname, ComponentsIn) ->
+	Dtid = process_uint32(DtidIn),
+	Dpdu = {dialogueResponse, #'AARE-apdu'{'protocol-version' = [version1],
+						'application-context-name' = ACname,
+						'result' = 0}},
+	ExtPdu = enc_dialg_ext(Dpdu),
+	{ok, EncComponents} = tcap_asn:encode('Components', ComponentsIn),
+	Msg = {'end', #'End'{dtid = Dtid, dialoguePortion = ExtPdu, components = EncComponents}},
+	enc_msg(Msg).
+
+
+enc_msg(Dlg) ->
+	{ok, Ret} = tcap_asn:encode('TCMessage', Dlg),
+	Ret.
+
+
+% build a BER-encoded Begin dialogue with Invoke component
+build_inv_begin(DlgId, InvId, ACname, Opcode, Argument) ->
+	C = build_inv_comp(InvId, Opcode, Argument),
+	build_begin(DlgId, ACname, [C]).
+
+% build a BER-encoded End dialogue with ReturnResultLast component
+build_retresl_end(Dtid, InvId, ACname, Argument) ->
+	C = build_retreslast_comp(InvId, Argument),
+	build_end(Dtid, ACname, [C]).