return proper sender TEID when rejecting new sessions

Make sure to return a proper TEID when rejecting new sessions due to an internal block (accept_new == false). Fixes #322
travelping · Feb 25, 2021 · 09bd8e6 · 09bd8e6
1 parent d71b404
commit 09bd8e6
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Showing 10 changed files with 73 additions and 15 deletions.
diff --git a/src/gtp_context.erl b/src/gtp_context.erl
@@ -291,13 +291,15 @@ port_message(#request{socket = Socket, info = Info} = Request,
     case get_handler_if(Socket, Msg) of
 	{ok, Interface, InterfaceOpts} ->
 	    case ergw:get_accept_new() of
-		true -> ok;
+		true ->
+		    validate_teid(Msg),
+		    Server = context_new(Socket, Info, Version, Interface, InterfaceOpts),
+		    port_message(Server, Request, Msg, false);
+
 		_ ->
-		    throw({error, no_resources_available})
-	    end,
-	    validate_teid(Msg),
-	    Server = context_new(Socket, Info, Version, Interface, InterfaceOpts),
-	    port_message(Server, Request, Msg, false);
+		    gtp_context:generic_error(Request, Msg, no_resources_available),
+		    ok
+	    end;
 
 	{error, _} = Error ->
 	    throw(Error)

diff --git a/src/gtp_v1_c.erl b/src/gtp_v1_c.erl
@@ -277,6 +277,10 @@ load_class(#gtp{type = g_pdu}) ->
 load_class(_) ->
     other.
 
+find_sender_teid(#gtp{
+		    ie = #{{tunnel_endpoint_identifier_control_plane,0} :=
+			       #tunnel_endpoint_identifier_control_plane{tei = TEID}}}) ->
+    TEID;
 find_sender_teid(_) ->
     undefined.
 

diff --git a/test/ergw_ggsn_test_lib.erl b/test/ergw_ggsn_test_lib.erl
@@ -469,14 +469,22 @@ validate_response(create_pdp_context_request, overload, Response, GtpC) ->
     validate_seq_no(Response, GtpC),
 
     %% this is debatable, but decoding the request would require even more resources.
-    %% validate_teid(Response, GtpC),
     validate_teid(Response, 0),
 
     ?match(#gtp{type = create_pdp_context_response,
 		ie = #{{cause,0} := #cause{value = no_resources_available}}},
 	   Response),
     GtpC;
 
+validate_response(create_pdp_context_request, reject_new, Response, GtpC) ->
+    validate_seq_no(Response, GtpC),
+    validate_teid(Response, GtpC),
+
+    ?match(#gtp{type = create_pdp_context_response,
+		ie = #{{cause,0} := #cause{value = no_resources_available}}},
+	   Response),
+    GtpC;
+
 validate_response(create_pdp_context_request, no_resources_available, Response, GtpC) ->
     validate_seq_no(Response, GtpC),
     validate_teid(Response, GtpC),

diff --git a/test/ergw_pgw_test_lib.erl b/test/ergw_pgw_test_lib.erl
@@ -382,12 +382,21 @@ make_request(echo_request, _SubType,
     #gtp{version = v2, type = echo_request, tei = undefined,
 	 seq_no = SeqNo, ie = IEs};
 
-make_request(create_session_request, missing_ie,
+make_request(create_session_request, missing_sender_teid,
 	     #gtpc{restart_counter = RCnt, seq_no = SeqNo}) ->
     IEs = [#v2_recovery{restart_counter = RCnt}],
     #gtp{version = v2, type = create_session_request, tei = 0,
 	 seq_no = SeqNo, ie = IEs};
 
+make_request(create_session_request, missing_ie,
+	     #gtpc{restart_counter = RCnt, seq_no = SeqNo,
+		   local_ip = LocalIP,
+		   local_control_tei = LocalCntlTEI}) ->
+    IEs = [#v2_recovery{restart_counter = RCnt},
+	   fq_teid(0, ?'S5/S8-C SGW', LocalCntlTEI, LocalIP)],
+    #gtp{version = v2, type = create_session_request, tei = 0,
+	 seq_no = SeqNo, ie = IEs};
+
 make_request(create_session_request, SubType,
 	     #gtpc{restart_counter = RCnt, seq_no = SeqNo,
 		   local_ip = LocalIP,
@@ -814,14 +823,22 @@ validate_response(_Type, invalid_teid, Response, GtpC) ->
 	   }, Response),
     GtpC;
 
-validate_response(create_session_request, missing_ie, Response, GtpC) ->
+validate_response(create_session_request, missing_sender_teid, Response, GtpC) ->
     validate_seq_no(Response, GtpC),
     validate_teid(Response, 0),
     ?match(#gtp{type = create_session_response,
 		ie = #{{v2_cause,0} := #v2_cause{v2_cause = mandatory_ie_missing}}},
 	   Response),
     GtpC;
 
+validate_response(create_session_request, missing_ie, Response, GtpC) ->
+    validate_seq_no(Response, GtpC),
+    validate_teid(Response, GtpC),
+    ?match(#gtp{type = create_session_response,
+		ie = #{{v2_cause,0} := #v2_cause{v2_cause = mandatory_ie_missing}}},
+	   Response),
+    GtpC;
+
 validate_response(create_session_request, aaa_reject, Response, GtpC) ->
     validate_seq_no(Response, GtpC),
     validate_teid(Response, GtpC),
@@ -840,14 +857,22 @@ validate_response(create_session_request, overload, Response, GtpC) ->
     validate_seq_no(Response, GtpC),
 
     %% this is debatable, but decoding the request would require even more resources.
-    %% validate_teid(Response, GtpC),
     validate_teid(Response, 0),
 
    ?match(#gtp{type = create_session_response,
 		ie = #{{v2_cause,0} := #v2_cause{v2_cause = no_resources_available}}},
 	  Response),
     GtpC;
 
+validate_response(create_session_request, reject_new, Response, GtpC) ->
+    validate_seq_no(Response, GtpC),
+    validate_teid(Response, GtpC),
+
+   ?match(#gtp{type = create_session_response,
+		ie = #{{v2_cause,0} := #v2_cause{v2_cause = no_resources_available}}},
+	  Response),
+    GtpC;
+
 validate_response(create_session_request, no_resources_available, Response, GtpC) ->
     validate_seq_no(Response, GtpC),
     validate_teid(Response, GtpC),

diff --git a/test/ergw_saegw_test_lib.erl b/test/ergw_saegw_test_lib.erl
@@ -491,6 +491,15 @@ validate_response(create_session_request, overload, Response, GtpC) ->
 	  Response),
     GtpC;
 
+validate_response(create_session_request, reject_new, Response, GtpC) ->
+    validate_seq_no(Response, GtpC),
+    validate_teid(Response, GtpC),
+
+   ?match(#gtp{type = create_session_response,
+		ie = #{{v2_cause,0} := #v2_cause{v2_cause = no_resources_available}}},
+	  Response),
+    GtpC;
+
 validate_response(create_session_request, invalid_apn, Response, GtpC) ->
     validate_seq_no(Response, GtpC),
     validate_teid(Response, GtpC),

diff --git a/test/ggsn_SUITE.erl b/test/ggsn_SUITE.erl
@@ -894,7 +894,7 @@ create_pdp_context_request_accept_new() ->
     [{doc, "Check the accept_new = false can block new contexts"}].
 create_pdp_context_request_accept_new(Config) ->
     ?equal(ergw:system_info(accept_new, false), true),
-    create_pdp_context(overload, Config),
+    create_pdp_context(reject_new, Config),
     ?equal(ergw:system_info(accept_new, true), false),
 
     ?equal([], outstanding_requests()),

diff --git a/test/ggsn_proxy_SUITE.erl b/test/ggsn_proxy_SUITE.erl
@@ -925,7 +925,7 @@ create_pdp_context_request_accept_new() ->
     [{doc, "Check the accept_new = false can block new connections"}].
 create_pdp_context_request_accept_new(Config) ->
     ?equal(ergw:system_info(accept_new, false), true),
-    create_pdp_context(overload, Config),
+    create_pdp_context(reject_new, Config),
     ?equal(ergw:system_info(accept_new, true), false),
 
     ?equal([], outstanding_requests()),

diff --git a/test/pgw_SUITE.erl b/test/pgw_SUITE.erl
@@ -588,6 +588,7 @@ common() ->
     [invalid_gtp_pdu,
      invalid_gtp_version,
      apn_lookup,
+     create_session_request_missing_sender_teid,
      create_session_request_missing_ie,
      create_session_request_aaa_reject,
      create_session_request_gx_fail,
@@ -1032,6 +1033,15 @@ invalid_gtp_version(Config) ->
     meck_validate(Config),
     ok.
 
+%%--------------------------------------------------------------------
+create_session_request_missing_sender_teid() ->
+    [{doc, "Check that Create Session Request IE validation works"}].
+create_session_request_missing_sender_teid(Config) ->
+    create_session(missing_sender_teid, Config),
+
+    meck_validate(Config),
+    ok.
+
 %%--------------------------------------------------------------------
 create_session_request_missing_ie() ->
     [{doc, "Check that Create Session Request IE validation works"}].
@@ -1170,7 +1180,7 @@ create_session_request_accept_new() ->
     [{doc, "Check the accept_new = false can block new session"}].
 create_session_request_accept_new(Config) ->
     ?equal(ergw:system_info(accept_new, false), true),
-    create_session(overload, Config),
+    create_session(reject_new, Config),
     ?equal(ergw:system_info(accept_new, true), false),
 
     meck_validate(Config),

diff --git a/test/pgw_proxy_SUITE.erl b/test/pgw_proxy_SUITE.erl
@@ -1010,7 +1010,7 @@ create_session_request_accept_new() ->
     [{doc, "Check the accept_new = false can block new session"}].
 create_session_request_accept_new(Config) ->
     ?equal(ergw:system_info(accept_new, false), true),
-    create_session(overload, Config),
+    create_session(reject_new, Config),
     ?equal(ergw:system_info(accept_new, true), false),
 
     ?equal([], outstanding_requests()),

diff --git a/test/saegw_s11_SUITE.erl b/test/saegw_s11_SUITE.erl
@@ -733,7 +733,7 @@ create_session_request_accept_new() ->
     [{doc, "Check the accept_new = false can block new session"}].
 create_session_request_accept_new(Config) ->
     ?equal(ergw:system_info(accept_new, false), true),
-    create_session(overload, Config),
+    create_session(reject_new, Config),
     ?equal(ergw:system_info(accept_new, true), false),
 
     meck_validate(Config),