s1ap_proxy: add E-RAB introspection API

Change-Id: I43dcfa613a4ee0de5b2f6619911fd92b1675acd6
---
M src/s1ap_proxy.erl
M test/s1ap_proxy_test.erl
2 files changed, 33 insertions(+), 8 deletions(-)


git pull ssh://gerrit.osmocom.org:29418/erlang/osmo-s1gw refs/changes/84/38684/1

diff --git a/src/s1ap_proxy.erl b/src/s1ap_proxy.erl
index 4452269..ea20106 100644
--- a/src/s1ap_proxy.erl
+++ b/src/s1ap_proxy.erl
@@ -42,6 +42,8 @@
          terminate/2]).
 -export([start_link/0,
          process_pdu/2,
+         fetch_erab/2,
+         fetch_erab_list/1,
          shutdown/1]).
 
 -include_lib("kernel/include/logger.hrl").
@@ -92,6 +94,18 @@
     gen_server:call(Pid, {?FUNCTION_NAME, PDU}).
 
 
+%% Fetch a single E-RAB from the registry (by UID)
+-spec fetch_erab(pid(), erab_uid()) -> {ok, pid()} | error.
+fetch_erab(Pid, UID) ->
+    gen_server:call(Pid, {?FUNCTION_NAME, UID}).
+
+
+%% Fetch all E-RABs from the registry in form of a list
+-spec fetch_erab_list(pid()) -> [{erab_uid(), pid()}].
+fetch_erab_list(Pid) ->
+    gen_server:call(Pid, ?FUNCTION_NAME).
+
+
 -spec shutdown(pid()) -> ok.
 shutdown(Pid) ->
     gen_server:stop(Pid).
@@ -111,6 +125,14 @@
     {Reply, S1} = handle_pdu_bin(OrigData, S0),
     {reply, Reply, S1};
 
+handle_call({fetch_erab, UID}, _From,
+            #proxy_state{erabs = ERABs} = S) ->
+    {reply, dict:find(UID, ERABs), S};
+
+handle_call(fetch_erab_list, _From,
+            #proxy_state{erabs = ERABs} = S) ->
+    {reply, dict:to_list(ERABs), S};
+
 handle_call(Info, From,
             #proxy_state{} = S) ->
     ?LOG_ERROR("unknown ~p() from ~p: ~p", [?FUNCTION_NAME, From, Info]),
diff --git a/test/s1ap_proxy_test.erl b/test/s1ap_proxy_test.erl
index cb562a2..9e94716 100644
--- a/test/s1ap_proxy_test.erl
+++ b/test/s1ap_proxy_test.erl
@@ -67,7 +67,9 @@
     SetupRspExp = e_rab_setup_rsp_pdu(?ADDR_C2U, ?TEID_C2U),
 
     [?_assertEqual({forward, SetupReqExp}, s1ap_proxy:process_pdu(Pid, SetupReqIn)),
-     ?_assertEqual({forward, SetupRspExp}, s1ap_proxy:process_pdu(Pid, SetupRspIn))].
+     ?_assertEqual({forward, SetupRspExp}, s1ap_proxy:process_pdu(Pid, SetupRspIn)),
+     ?_assertMatch({ok, _}, s1ap_proxy:fetch_erab(Pid, {7, 9, 6})),
+     ?_assertMatch([_], s1ap_proxy:fetch_erab_list(Pid))].
 
 
 test_e_rab_setup_req_fail(#{handler := Pid}) ->
@@ -79,9 +81,8 @@
     SetupReqIn = e_rab_setup_req_pdu(?ADDR_U2C, ?TEID_U2C),
     SetupRspExp = e_rab_setup_rsp_fail_pdu(),
 
-    %% TODO: make sure that the E-RAB FSM has been terminated
-
-    [?_assertEqual({reply, SetupRspExp}, s1ap_proxy:process_pdu(Pid, SetupReqIn))].
+    [?_assertEqual({reply, SetupRspExp}, s1ap_proxy:process_pdu(Pid, SetupReqIn)),
+     ?_assertEqual([], s1ap_proxy:fetch_erab_list(Pid))].
 
 
 test_e_rab_release_cmd(#{handler := Pid}) ->
@@ -94,12 +95,12 @@
     %% [eNB -> MME] E-RAB RELEASE RESPONSE
     ReleaseRsp = e_rab_release_rsp_pdu(),
 
-    %% TODO: make sure that the E-RAB FSM has been terminated
-
     [?_assertMatch({forward, _}, s1ap_proxy:process_pdu(Pid, SetupReq)),
      ?_assertMatch({forward, _}, s1ap_proxy:process_pdu(Pid, SetupRsp)),
+     ?_assertMatch([_], s1ap_proxy:fetch_erab_list(Pid)),
      ?_assertEqual({forward, ReleaseCmd}, s1ap_proxy:process_pdu(Pid, ReleaseCmd)),
-     ?_assertEqual({forward, ReleaseRsp}, s1ap_proxy:process_pdu(Pid, ReleaseRsp))].
+     ?_assertEqual({forward, ReleaseRsp}, s1ap_proxy:process_pdu(Pid, ReleaseRsp)),
+     ?_assertEqual([], s1ap_proxy:fetch_erab_list(Pid))].
 
 
 test_e_rab_release_ind(#{handler := Pid}) ->
@@ -111,6 +112,7 @@
     ReleaseInd = e_rab_release_ind_pdu(),
 
     %% TODO: make sure that the E-RAB FSM has been terminated
+    %% FIXME: erab_fsm does not tear down immediately, but after a timeout
 
     [?_assertMatch({forward, _}, s1ap_proxy:process_pdu(Pid, SetupReq)),
      ?_assertMatch({forward, _}, s1ap_proxy:process_pdu(Pid, SetupRsp)),
@@ -135,7 +137,8 @@
     InitCtxSetupRspExp = initial_context_setup_rsp_pdu(?ADDR_C2U, ?TEID_C2U),
 
     [?_assertEqual({forward, InitCtxSetupReqExp}, s1ap_proxy:process_pdu(Pid, InitCtxSetupReqIn)),
-     ?_assertEqual({forward, InitCtxSetupRspExp}, s1ap_proxy:process_pdu(Pid, InitCtxSetupRspIn))].
+     ?_assertEqual({forward, InitCtxSetupRspExp}, s1ap_proxy:process_pdu(Pid, InitCtxSetupRspIn)),
+     ?_assertMatch([_], s1ap_proxy:fetch_erab_list(Pid))].
 
 
 %% ------------------------------------------------------------------

