SUA: add functions for SUA <-> SCCP conversion

1 files changed, 238 insertions, 0 deletions

diff --git a/src/sua_sccp_conv.erl b/src/sua_sccp_conv.erl
new file mode 100644
index 0000000..2483ba5
--- /dev/null
+++ b/src/sua_sccp_conv.erl
@@ -0,0 +1,238 @@
+% Conversion between SUA messages and #sccp_msg{}
+
+% (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/>.
+
+% FIXME: this currently only supports connection-less SCCP
+
+-module(sua_sccp_conv).
+-author('Harald Welte <laforge@gnumonks.org>').
+
+-include("sua.hrl").
+-include("sccp.hrl").
+
+-export([sua_to_sccp/1, sccp_to_sua/1]).
+
+sua_to_sccp(M=#sua_msg{msg_class = Class, msg_type = Type}) ->
+	sua_to_sccp(Class, Type, M).
+sua_to_sccp(?SUA_MSGC_CL, ?SUA_CL_CLDT, Sua) ->
+	Params = sua_to_sccp_params(Sua),
+	#sccp_msg{msg_type = ?SCCP_MSGT_UDT,
+		parameters = Params};
+sua_to_sccp(?SUA_MSGC_CL, ?SUA_CL_CLDR, Sua) ->
+	Params = sua_to_sccp_params(Sua),
+	#sccp_msg{msg_type = ?SCCP_MSGT_UDTS,
+		parameters = Params}.
+
+sccp_to_sua(M=#sccp_msg{msg_type = Type, parameters = Params}) ->
+	sccp_to_sua(Type, Params).
+sccp_to_sua(Type, Params) when	Type == ?SCCP_MSGT_UDT;
+				Type == ?SCCP_MSGT_XUDT;
+				Type == ?SCCP_MSGT_LUDT ->
+	Opts = sccp_to_sua_params(Params),
+	#sua_msg{msg_class = ?SUA_MSGC_CL, msg_type = ?SUA_CL_CLDT,
+		 payload = Opts};
+sccp_to_sua(Type, Params) when 	Type == ?SCCP_MSGT_UDTS;
+				Type == ?SCCP_MSGT_XUDTS;
+				Type == ?SCCP_MSGT_LUDTS ->
+	Opts = sccp_to_sua_params(Params),
+	#sua_msg{msg_class = ?SUA_MSGC_CL, msg_type = ?SUA_CL_CLDR,
+		 payload = Opts}.
+
+
+% CLDT parameters:
+% 	?SUA_IEI_ROUTE_CTX, ?SUA_IEI_PROTO_CLASS, ?SUA_IEI_SRC_ADDR,
+% 	?SUA_IEI_DEST_ADDR, ?SUA_IEI_SEQ_CTRL, ?SUA_IEI_S7_HOP_CTR,
+% 	?SUA_IEI_IMPORTANCE, ?SUA_IEI_MSG_PRIO, ?SUA_IEI_CORR_ID,
+% 	?SUA_IEI_SEGMENTATION, ?SUA_IEI_DATA
+
+sua_to_sccp_params(#sua_msg{msg_class=Class, msg_type=Type, payload=Payload}) ->
+	sua_to_sccp_params(Class, Type, Payload).
+sua_to_sccp_params(Class, Type, Payload) ->
+	sua_to_sccp_params(Class, Type, Payload, []).
+sua_to_sccp_params(Class, Type, [], List) ->
+	List;
+sua_to_sccp_params(Class, Type, [{ParTag, ParVal}|Remain], List) ->
+	NewPars = sua_to_sccp_param(Class, Type, ParTag, ParVal),
+	sua_to_sccp_params(Class, Type, Remain, List ++ NewPars).
+
+% convert an individual SUA parameter to a SCCP option
+sua_to_sccp_param(_, _, ?SUA_IEI_PROTO_CLASS, Remain) ->
+	<<_:24, RetErr:1, _:5, Class:2>> = Remain,
+	[{?SCCP_PNC_PROTOCOL_CLASS, Class}];
+sua_to_sccp_param(_, _, ?SUA_IEI_SRC_ADDR, Remain) ->
+	Addr = sua_to_sccp_addr(Remain),
+	[{?SCCP_PNC_CALLING_PARTY_ADDRESS, Addr}];
+sua_to_sccp_param(_, _, ?SUA_IEI_DEST_ADDR, Remain) ->
+	Addr = sua_to_sccp_addr(Remain),
+	[{?SCCP_PNC_CALLED_PARTY_ADDRESS, Addr}];
+sua_to_sccp_param(_, _, ?SUA_IEI_SEQ_CTRL, Remain) ->
+	[{?SCCP_PNC_SEQUENCING, Remain}];
+sua_to_sccp_param(_, _, ?SUA_IEI_S7_HOP_CTR, Remain) ->
+	<<_:24, HopCtr:8>> = Remain,
+	[{?SCCP_PNC_HOP_COUNTER, HopCtr}];
+sua_to_sccp_param(_, _, ?SUA_IEI_IMPORTANCE, Remain) ->
+	<<_:24, Imp:8>> = Remain,
+	[{?SCCP_PNC_IMPORTANCE, Imp}];
+sua_to_sccp_param(_, _, ?SUA_IEI_DATA, Remain) ->
+	[{?SCCP_PNC_DATA, Remain}].
+
+sccp_to_sua_params(#sccp_msg{msg_type=Type, parameters=Params}) ->
+	sccp_to_sua_params(Type, Params).
+sccp_to_sua_params(Type, Params) when is_list(Params) ->
+	sccp_to_sua_params(Type, Params, []).
+sccp_to_sua_params(Type, [], List) ->
+	List;
+sccp_to_sua_params(Type, [{ParTag, ParVal}|Tail], List) ->
+	NewPars = sccp_to_sua_param(Type, ParTag, ParVal),
+	sccp_to_sua_params(Type, Tail, List ++ NewPars).
+
+sccp_to_sua_param(_, ?SCCP_PNC_PROTOCOL_CLASS, Class) ->
+	[{?SUA_IEI_PROTO_CLASS, <<0:24, 0:1, 0:5, Class:2>>}];
+sccp_to_sua_param(_, ?SCCP_PNC_CALLING_PARTY_ADDRESS, Addr) ->
+	AddrSua = sccp_to_sua_addr(Addr),
+	[{?SUA_IEI_SRC_ADDR, AddrSua}];
+sccp_to_sua_param(_, ?SCCP_PNC_CALLED_PARTY_ADDRESS, Addr) ->
+	AddrSua = sccp_to_sua_addr(Addr),
+	[{?SUA_IEI_DEST_ADDR, AddrSua}];
+sccp_to_sua_param(_, ?SCCP_PNC_SEQUENCING, Par) ->
+	[{?SUA_IEI_SEQ_CTRL, Par}];
+sccp_to_sua_param(_, ?SCCP_PNC_HOP_COUNTER, Hop) ->
+	[{?SUA_IEI_S7_HOP_CTR, <<0:24, Hop:8>>}];
+sccp_to_sua_param(_, ?SCCP_PNC_IMPORTANCE, Imp) ->
+	[{?SUA_IEI_IMPORTANCE, <<0:24, Imp:8>>}];
+sccp_to_sua_param(_, ?SCCP_PNC_DATA, Data) ->
+	[{?SUA_IEI_DATA, Data}].
+
+sua_to_sccp_addr(SuaBin) ->
+	<<RoutInd:16, _:13, GTinc:1, PCinc:1, SSNinc:1, Remain/binary>> = SuaBin,
+	ParList = addr_pars_to_list(Remain),
+	case GTinc of
+		1 ->
+			GTopt = proplists:get_value(?SUA_IEI_GT, ParList),
+			GT = parse_sua_gt(GTopt);
+		0 ->
+			GT = undefined
+	end,
+	case PCinc of
+		1 ->
+			PCopt = proplists:get_value(?SUA_IEI_PC, ParList),
+			PC = parse_sua_pc(PCopt);
+		0 ->
+			PC = undefined
+	end,
+	case SSNinc of
+		1 ->
+			SSNopt = proplists:get_value(?SUA_IEI_SSN, ParList),
+			SSN = parse_sua_ssn(SSNopt);
+		0 ->
+			SSN = undefined
+	end,
+	case RoutInd of
+		?SUA_RI_GT ->
+			RoutSSN = 0;
+		?SUA_RI_SSN_PC ->
+			RoutSSN = 1
+	end,
+	#sccp_addr{route_on_ssn = RoutSSN, point_code = PC, ssn = SSN, global_title = GT}.
+
+addr_pars_to_list(Bin) ->
+	sua_codec:parse_xua_opts(Bin).
+
+sccp_to_sua_addr(Addr) when is_record(Addr, sccp_addr) ->
+	#sccp_addr{route_on_ssn = RoutOnSsn, point_code = PC, ssn = SSN,
+		   global_title = GT} = Addr,
+	case GT of
+		#global_title{} ->
+			GTopt = encode_sua_gt(GT),
+			GTinc = 1;
+		_ ->
+			GTopt = [],
+			GTinc = 0
+	end,
+	case PC of
+		Int when is_integer(Int) ->
+			PCopt = encode_sua_pc(PC),
+			PCinc = 1;
+		_ ->
+			PCopt = [],
+			PCinc = 0
+	end,
+	case SSN of
+		Int2 when is_integer(Int2) ->
+			SSNopt = encode_sua_ssn(SSN),
+			SSNinc = 1;
+		_ ->
+			SSNopt = [],
+			SSNinc = 0
+	end,
+	case RoutOnSsn of
+		0 ->
+			RoutInd = ?SUA_RI_GT;
+		1 ->
+			RoutInd = ?SUA_RI_SSN_PC
+	end,
+	Tail = sua_codec:encode_xua_opts(GTopt ++ PCopt ++ SSNopt),
+	<<RoutInd:16, 0:13, GTinc:1, PCinc:1, SSNinc:1, Tail/binary>>.
+
+parse_sua_gt(Bin) ->
+	<<_:24, GTI:8, NoDigits:8, TransType:8, NumPlan:8, NAI:8, Remain/binary>> = Bin,
+	Number = parse_sua_gt_digits(NoDigits, Remain),
+	#global_title{gti = GTI, nature_of_addr_ind = NAI,
+		      trans_type = TransType, encoding = fixme,
+		      numbering_plan = NumPlan,
+		      phone_number = Number}.
+encode_sua_gt(Gt) when is_record(Gt, global_title) ->
+	#global_title{gti = GTI, nature_of_addr_ind = NAI,
+		      trans_type = TransType, encoding = Encoding,
+		      numbering_plan = NumPlan,
+		      phone_number = Number} = Gt,
+	NoDigits = count_digits(Number),
+	DigitBin = encode_sua_gt_digits(Number),
+	<<0:24, GTI:8, NoDigits:8, TransType:8, NumPlan:8, NAI:8, DigitBin/binary>>.
+
+count_digits(Number) when is_integer(Number) ->
+	BcdList = osmo_util:int2digit_list(Number),
+	count_digits(BcdList);
+count_digits(Number) when is_list(Number) ->
+	length(Number).
+
+
+parse_sua_gt_digits(NoDigits, Remain) ->
+	% as opposed to ISUP/SCCP, we can have more than one nibble padding,
+	OddEven = NoDigits rem 1,
+	case OddEven of
+		0 ->
+			ByteLen = NoDigits/2;
+		1 ->
+			ByteLen = NoDigits/2 + 1
+	end,
+	<<Bin:ByteLen/binary, _/binary>> = Remain,
+	isup_codec:parse_isup_party(Bin, OddEven).
+encode_sua_gt_digits(Digits) when is_list(Digits); is_integer(Digits) ->
+	% Assume that overall option encoder will do the padding...
+	isup_codec:encode_isup_party(Digits).
+
+parse_sua_pc(<<PC:32/big>>) ->
+	PC.
+encode_sua_pc(Pc) when is_integer(Pc) ->
+	<<Pc:32/big>>.
+
+parse_sua_ssn(<<_:24, SSN:8>>) ->
+	SSN.
+encode_sua_ssn(Ssn) when is_integer(Ssn) ->
+	<<0:24, Ssn:8>>.