From 6cf416140345bdf8f1d1fb9cfdf7be95779cafdf Mon Sep 17 00:00:00 2001
From: Vadim Yanitskiy <axilirator@gmail.com>
Date: Mon, 19 Aug 2019 23:28:39 +0200
Subject: [PATCH] ipa_proto.erl: fix IPA IDENTITY REQUEST handling

---
 src/ipa_proto.erl | 41 +++++++++++++++++++++++++++++++++++------
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/src/ipa_proto.erl b/src/ipa_proto.erl
index 9a3f3d0..8904072 100644
--- a/src/ipa_proto.erl
+++ b/src/ipa_proto.erl
@@ -93,7 +93,8 @@ controlling_process(Socket, StreamID, NewPid) ->
 
 % unblock the socket from further processing
 unblock(Socket) ->
-	send_ccm_id_get(Socket),
+	% FIXME: why are we sending it here?!?
+	% send_ccm_id_get(Socket),
 	call_sync_sock(Socket, {ipa_unblock, Socket}).
 
 
@@ -260,15 +261,43 @@ loop(S, StreamMap) ->
 			ok
 	end.
 
+% Length-Tag-Value
+gen_ccm_ltv_str(Tag, String) ->
+	Len = string:len(String) + 1 + 1,
+	BinString = list_to_binary(String),
+	<< 16#00, Len, Tag, BinString/binary, 16#00 >>.
+
+% Parse Length-Tag list from the Request
+gen_ccm_id_resp(Response, << >>) -> Response;
+gen_ccm_id_resp(Response, LTList) ->
+	<< _Len, Tag, Rest/binary >> = LTList,
+	case Tag of
+		% Unit ID
+		16#08 ->
+			LTV = gen_ccm_ltv_str(Tag, "0/0/0"),
+			gen_ccm_id_resp(<< Response/binary, LTV/binary >>, Rest);
+		% Serial number, Unit name
+		% FIXME: hard-coded values!
+		16#00 ->
+			LTV = gen_ccm_ltv_str(Tag, "EUSE-OsmoSMSC-00-00-00-00-00-00"),
+			gen_ccm_id_resp(<< Response/binary, LTV/binary >>, Rest);
+		16#01 ->
+			LTV = gen_ccm_ltv_str(Tag, "EUSE-OsmoSMSC-00-00-00-00-00-00"),
+			gen_ccm_id_resp(<< Response/binary, LTV/binary >>, Rest);
+		_ ->
+			% HACK: for anything else, just use "00:00:00:00:00:00"
+			LTV = gen_ccm_ltv_str(Tag, "00:00:00:00:00:00"),
+			gen_ccm_id_resp(<< Response/binary, LTV/binary >>, Rest)
+	end.
+
 % Respond with PONG to PING
 process_ccm_msg(Socket, StreamID, ?IPAC_MSGT_PING, _) ->
 	io:format("Socket ~p Stream ~p: PING -> PONG~n", [Socket, StreamID]),
 	send(Socket, StreamID, <<?IPAC_MSGT_PONG>>);
-% Simply respond to ID_ACK with ID_ACK
-process_ccm_msg(Socket, StreamID, ?IPAC_MSGT_ID_ACK, _) ->
-	io:format("Socket ~p Stream ~p: ID_ACK -> ID_ACK~n", [Socket, StreamID]),
-	send(Socket, StreamID, <<?IPAC_MSGT_ID_ACK>>);
-% Simply respond to ID_RESP with ID_ACK
+process_ccm_msg(Socket, StreamID, ?IPAC_MSGT_ID_GET, Params) ->
+	io:format("Socket ~p Stream ~p: ID_GET -> ID_RESP~n", [Socket, StreamID]),
+	Response = gen_ccm_id_resp(<<?IPAC_MSGT_ID_RESP>>, list_to_binary(Params)),
+	send(Socket, StreamID, Response);
 process_ccm_msg(Socket, StreamID, ?IPAC_MSGT_ID_RESP, _) ->
 	io:format("Socket ~p Stream ~p: ID_RESP -> ID_ACK~n", [Socket, StreamID]),
 	send(Socket, StreamID, <<?IPAC_MSGT_ID_ACK>>);