fixeria has uploaded this change for review.
erab_fsm: fix message flow misconceptions
Change-Id: Ie6f65516fd5621acf002de97eeeb2b9b0b4fae4a
Fixes: 9f2a172 "erab_fsm: E-RAB FSM implementation"
---
M src/erab_fsm.erl
M test/erab_fsm_test.erl
M test/pfcp_mock.erl
M test/pfcp_mock.hrl
4 files changed, 48 insertions(+), 48 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/erlang/osmo-s1gw refs/changes/03/37803/1
diff --git a/src/erab_fsm.erl b/src/erab_fsm.erl
index 8a9d0ec..abc25b1 100644
--- a/src/erab_fsm.erl
+++ b/src/erab_fsm.erl
@@ -66,10 +66,10 @@
-type teid() :: 0..16#ffffffff.
-record(erab_state, {from :: undefined | gen_statem:from(), %% destination to use when replying
- teid_from_access :: undefined | teid(), %% TEID to be used in eNB -> UPF
- teid_to_access :: undefined | teid(), %% TEID to be used in UPF -> eNB
- teid_from_core :: undefined | teid(), %% TEID to be used in PGW -> UPF
- teid_to_core :: undefined | teid(), %% TEID to be used in UPF -> PGW
+ teid_upf2core :: undefined | teid(), %% TEID to be used in UPF -> Core
+ teid_core2upf :: undefined | teid(), %% TEID to be used in UPF <- Core
+ teid_acc2upf :: undefined | teid(), %% TEID to be used in UPF <- Access
+ teid_upf2acc :: undefined | teid(), %% TEID to be used in UPF -> Access
seid_loc :: undefined | pfcp_peer:pfcp_seid(), %% local SEID, chosen by us
seid_rem :: undefined | pfcp_peer:pfcp_seid() %% remote SEID, chosen by the UPF
}).
@@ -89,10 +89,10 @@
gen_statem:start_link(?MODULE, [UID], []).
-%% @doc Indicate reception of E-RAB setup request (from the eNB).
+%% @doc Indicate reception of E-RAB setup request (from core).
%% @param Pid PID of an erab_fsm.
-%% @param TEID TEID chosen by the eNB.
-%% @returns TEID to be sent to the core; an error otherwise.
+%% @param TEID TEID indicated by the MME.
+%% @returns TEID to be sent to the eNB; an error otherwise.
%% @end
-spec erab_setup_req(pid(), teid()) -> {ok, teid()} |
{error, term()}.
@@ -100,10 +100,10 @@
gen_statem:call(Pid, {?FUNCTION_NAME, TEID}).
-%% @doc Indicate reception of E-RAB setup response (from the core).
+%% @doc Indicate reception of E-RAB setup response (from access).
%% @param Pid PID of an erab_fsm.
-%% @param TEID TEID chosen by the core.
-%% @returns TEID to be sent to the eNB; an error otherwise.
+%% @param TEID TEID indicated by the eNB.
+%% @returns TEID to be sent to the MME; an error otherwise.
%% @end
-spec erab_setup_rsp(pid(), teid()) -> {ok, teid()} |
{error, term()}.
@@ -142,18 +142,18 @@
[state_functions, state_enter].
-%% state WAIT_SETUP_REQ :: wait E-RAB SETUP Req from the Access
+%% state WAIT_SETUP_REQ :: wait E-RAB SETUP Req from core
erab_wait_setup_req(enter, ?FUNCTION_NAME, S) ->
?LOG_DEBUG("State enter: ~p", [?FUNCTION_NAME]),
{keep_state, S};
erab_wait_setup_req({call, From},
- {erab_setup_req, TEID_FromAcc},
+ {erab_setup_req, TEID_U2C},
#erab_state{} = S) ->
- ?LOG_DEBUG("Rx E-RAB SETUP Req (Access TEID ~p)", [TEID_FromAcc]),
+ ?LOG_DEBUG("Rx E-RAB SETUP Req (TEID UPF -> Core ~p)", [TEID_U2C]),
{next_state, session_establish,
S#erab_state{from = From,
- teid_from_access = TEID_FromAcc}};
+ teid_upf2core = TEID_U2C}};
erab_wait_setup_req(Event, EventData, S) ->
?LOG_ERROR("Unexpected event ~p: ~p", [Event, EventData]),
@@ -182,15 +182,15 @@
seid = SEID_Rsp, %% matches F-SEID we sent in the ESTABLISH Req
ie = #{pfcp_cause := 'Request accepted',
f_seid := #f_seid{seid = F_SEID},
- created_pdr := [#{f_teid := #f_teid{teid = TEID_ToCore}},
- #{f_teid := #f_teid{teid = TEID_ToAcc}}]}} ->
+ created_pdr := [#{f_teid := #f_teid{teid = TEID_C2U}},
+ #{f_teid := #f_teid{teid = TEID_A2U}}]}} ->
?LOG_DEBUG("PFCP session established"),
{next_state, erab_wait_setup_rsp,
S#erab_state{from = undefined,
seid_rem = F_SEID, %% SEID to be used in further requests from us
- teid_to_core = TEID_ToCore,
- teid_to_access = TEID_ToAcc},
- [{reply, From, {ok, TEID_ToCore}}]};
+ teid_core2upf = TEID_C2U,
+ teid_acc2upf = TEID_A2U},
+ [{reply, From, {ok, TEID_A2U}}]};
_ ->
?LOG_ERROR("Rx unexpected PFCP PDU: ~p", [PDU]),
{stop_and_reply,
@@ -203,7 +203,7 @@
{keep_state, S}.
-%% state WAIT_SETUP_RSP :: wait E-RAB SETUP Rsp from the Core
+%% state WAIT_SETUP_RSP :: wait E-RAB SETUP Rsp from access
erab_wait_setup_rsp(enter, OldState, S) ->
?LOG_DEBUG("State change: ~p -> ~p", [OldState, ?FUNCTION_NAME]),
{next_state, ?FUNCTION_NAME, S, %% loop transition to enable state_timeout
@@ -213,12 +213,12 @@
{stop, {shutdown, timeout}};
erab_wait_setup_rsp({call, From},
- {erab_setup_rsp, TEID_FromCore},
+ {erab_setup_rsp, TEID_U2A},
#erab_state{} = S) ->
- ?LOG_DEBUG("Rx E-RAB SETUP Rsp (Core TEID ~p)", [TEID_FromCore]),
+ ?LOG_DEBUG("Rx E-RAB SETUP Rsp (TEID UPF -> Access ~p)", [TEID_U2A]),
{next_state, session_modify,
S#erab_state{from = From,
- teid_from_core = TEID_FromCore}};
+ teid_upf2acc = TEID_U2A}};
%% Catch-all handler for this state
erab_wait_setup_rsp(Event, EventData, S) ->
@@ -243,7 +243,7 @@
session_modify(info, #pfcp{} = PDU,
#erab_state{from = From,
seid_loc = SEID_Rsp,
- teid_to_access = TEID_ToAcc} = S) ->
+ teid_core2upf = TEID_C2U} = S) ->
case PDU of
#pfcp{type = session_modification_response,
seid = SEID_Rsp, %% matches F-SEID we sent in the ESTABLISH Req
@@ -251,7 +251,7 @@
?LOG_DEBUG("PFCP session modified"),
{next_state, erab_setup,
S#erab_state{from = undefined},
- [{reply, From, {ok, TEID_ToAcc}}]};
+ [{reply, From, {ok, TEID_C2U}}]};
_ ->
?LOG_ERROR("Rx unexpected PFCP PDU: ~p", [PDU]),
{stop_and_reply,
@@ -322,7 +322,7 @@
{keep_state, S}.
-%% state WAIT_RELEASE_RSP :: wait E-RAB RELEASE Rsp from the Core
+%% state WAIT_RELEASE_RSP :: wait E-RAB RELEASE Rsp
erab_wait_release_rsp(enter, OldState, S) ->
?LOG_DEBUG("State change: ~p -> ~p", [OldState, ?FUNCTION_NAME]),
{next_state, ?FUNCTION_NAME, S, %% loop transition to enable state_timeout
@@ -371,7 +371,7 @@
-spec session_establish_req(erab_state()) -> pfcp_peer:pfcp_session_rsp().
session_establish_req(#erab_state{seid_loc = F_SEID, %% used as F-SEID
- teid_from_access = TEID_FromAcc}) ->
+ teid_upf2core = TEID_U2C}) ->
%% Packet Detection Rules
OHR = #outer_header_removal{header = 'GTP-U/UDP/IPv4'},
PDRs = [#{pdr_id => {pdr_id, 1}, %% -- for Core -> Access
@@ -392,10 +392,10 @@
OHC = #outer_header_creation{n6 = false,
n19 = false,
type = 'GTP-U',
- teid = TEID_FromAcc,
+ teid = TEID_U2C,
ipv4 = <<127,0,0,1>>}, %% XXX: Core facing addr of the UPF
FARs = [#{far_id => {far_id, 1}, %% -- for Core -> Access
- %% We don't know the Core side TEID / GTP-U address yet, so we set
+ %% We don't know the Access side TEID / GTP-U address yet, so we set
%% this FAR to DROP and modify it when we get E-RAB SETUP RESPONSE.
apply_action => #{'DROP' => []}},
#{far_id => {far_id, 2}, %% -- for Access -> Core
@@ -408,12 +408,12 @@
-spec session_modify_req(erab_state()) -> pfcp_peer:pfcp_session_rsp().
session_modify_req(#erab_state{seid_rem = SEID, %% SEID allocated to us
- teid_from_core = TEID_FromCore}) ->
+ teid_upf2acc = TEID_U2A}) ->
%% Forwarding Action Rules
OHC = #outer_header_creation{n6 = false,
n19 = false,
type = 'GTP-U',
- teid = TEID_FromCore,
+ teid = TEID_U2A,
ipv4 = <<127,0,0,1>>}, %% XXX: Access facing addr of the UPF
FARs = [#{far_id => {far_id, 1}, %% -- for Core -> Access
%% Now we know the Core side TEID / GTP-U address, so we modify
diff --git a/test/erab_fsm_test.erl b/test/erab_fsm_test.erl
index fce03fd..5c42f61 100644
--- a/test/erab_fsm_test.erl
+++ b/test/erab_fsm_test.erl
@@ -57,8 +57,8 @@
%% ------------------------------------------------------------------
test_erab_setup_success(Pid) ->
- [?_assertEqual({ok, ?TEID_ToCore}, erab_fsm:erab_setup_req(Pid, ?TEID_FromAcc)),
- ?_assertEqual({ok, ?TEID_ToAcc}, erab_fsm:erab_setup_rsp(Pid, ?TEID_FromCore)),
+ [?_assertEqual({ok, ?TEID_A2U}, erab_fsm:erab_setup_req(Pid, ?TEID_U2C)),
+ ?_assertEqual({ok, ?TEID_C2U}, erab_fsm:erab_setup_rsp(Pid, ?TEID_U2A)),
?_assertEqual(ok, erab_fsm:shutdown(Pid)),
?_assertNot(erlang:is_process_alive(Pid))].
@@ -71,7 +71,7 @@
pfcp_mock:mock_req(session_establish_req, PDU),
unlink(Pid), %% we expect the FSM to terminate abnormally
Error = {unexp_pdu, session_establish},
- [?_assertEqual({error, Error}, erab_fsm:erab_setup_req(Pid, ?TEID_FromAcc)),
+ [?_assertEqual({error, Error}, erab_fsm:erab_setup_req(Pid, ?TEID_U2C)),
?_assertNot(erlang:is_process_alive(Pid))].
@@ -81,14 +81,14 @@
pfcp_mock:mock_req(session_modify_req, PDU),
unlink(Pid), %% we expect the FSM to terminate abnormally
Error = {unexp_pdu, session_modify},
- [?_assertEqual({ok, ?TEID_ToCore}, erab_fsm:erab_setup_req(Pid, ?TEID_FromAcc)),
- ?_assertEqual({error, Error}, erab_fsm:erab_setup_rsp(Pid, ?TEID_FromCore)),
+ [?_assertEqual({ok, ?TEID_A2U}, erab_fsm:erab_setup_req(Pid, ?TEID_U2C)),
+ ?_assertEqual({error, Error}, erab_fsm:erab_setup_rsp(Pid, ?TEID_U2A)),
?_assertNot(erlang:is_process_alive(Pid))].
test_erab_release_success(Pid) ->
- [?_assertEqual({ok, ?TEID_ToCore}, erab_fsm:erab_setup_req(Pid, ?TEID_FromAcc)),
- ?_assertEqual({ok, ?TEID_ToAcc}, erab_fsm:erab_setup_rsp(Pid, ?TEID_FromCore)),
+ [?_assertEqual({ok, ?TEID_A2U}, erab_fsm:erab_setup_req(Pid, ?TEID_U2C)),
+ ?_assertEqual({ok, ?TEID_C2U}, erab_fsm:erab_setup_rsp(Pid, ?TEID_U2A)),
?_assertEqual(ok, erab_fsm:erab_release_req(Pid)),
?_assertEqual(ok, erab_fsm:erab_release_rsp(Pid)),
?_assertNot(erlang:is_process_alive(Pid))].
@@ -100,8 +100,8 @@
pfcp_mock:mock_req(session_delete_req, PDU),
unlink(Pid), %% we expect the FSM to terminate abnormally
Error = {unexp_pdu, session_delete},
- [?_assertEqual({ok, ?TEID_ToCore}, erab_fsm:erab_setup_req(Pid, ?TEID_FromAcc)),
- ?_assertEqual({ok, ?TEID_ToAcc}, erab_fsm:erab_setup_rsp(Pid, ?TEID_FromCore)),
+ [?_assertEqual({ok, ?TEID_A2U}, erab_fsm:erab_setup_req(Pid, ?TEID_U2C)),
+ ?_assertEqual({ok, ?TEID_C2U}, erab_fsm:erab_setup_rsp(Pid, ?TEID_U2A)),
?_assertEqual({error, Error}, erab_fsm:erab_release_req(Pid)),
?_assertNot(erlang:is_process_alive(Pid))].
@@ -114,8 +114,8 @@
test_erab_shutdown_session_del(Pid) ->
- [?_assertEqual({ok, ?TEID_ToCore}, erab_fsm:erab_setup_req(Pid, ?TEID_FromAcc)),
- ?_assertEqual({ok, ?TEID_ToAcc}, erab_fsm:erab_setup_rsp(Pid, ?TEID_FromCore)),
+ [?_assertEqual({ok, ?TEID_A2U}, erab_fsm:erab_setup_req(Pid, ?TEID_U2C)),
+ ?_assertEqual({ok, ?TEID_C2U}, erab_fsm:erab_setup_rsp(Pid, ?TEID_U2A)),
?_assertEqual(ok, erab_fsm:shutdown(Pid)),
?_assertNot(erlang:is_process_alive(Pid))].
diff --git a/test/pfcp_mock.erl b/test/pfcp_mock.erl
index c9f8297..635223a 100644
--- a/test/pfcp_mock.erl
+++ b/test/pfcp_mock.erl
@@ -89,8 +89,8 @@
pdu_session_establish_rsp() ->
IEs = #{pfcp_cause => 'Request accepted',
f_seid => #f_seid{seid = ?SEID_Rem},
- created_pdr => [#{f_teid => #f_teid{teid = ?TEID_ToCore}},
- #{f_teid => #f_teid{teid = ?TEID_ToAcc}}]},
+ created_pdr => [#{f_teid => #f_teid{teid = ?TEID_C2U}},
+ #{f_teid => #f_teid{teid = ?TEID_A2U}}]},
pdu_rsp(session_establishment_response, ?SEID_Loc, IEs).
diff --git a/test/pfcp_mock.hrl b/test/pfcp_mock.hrl
index 06b5c5a..3a54ade 100644
--- a/test/pfcp_mock.hrl
+++ b/test/pfcp_mock.hrl
@@ -1,9 +1,9 @@
-define(SEID_Loc, 16#dead).
-define(SEID_Rem, 16#beef).
--define(TEID_FromAcc, 16#0001).
--define(TEID_FromCore, 16#0002).
--define(TEID_ToAcc, 16#0003).
--define(TEID_ToCore, 16#0004).
+-define(TEID_U2C, 16#0001). %% UPF -> Core
+-define(TEID_C2U, 16#0101). %% UPF <- Core
+-define(TEID_A2U, 16#0202). %% UPF <- Access
+-define(TEID_U2A, 16#0002). %% UPF -> Access
%% vim:set ts=4 sw=4 et:
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