[M] Change in ...osmo-s1gw[master]: s1ap_proxy: signal GTP-U addr and eNB info to sctp_proxy - gerrit-log

18 Dec 2025

fixeria has submitted this change. ( https://gerrit.osmocom.org/c/erlang/osmo-s1gw/+/41619?usp=email )
Change subject: s1ap_proxy: signal GTP-U addr and eNB info to sctp_proxy
......................................................................
s1ap_proxy: signal GTP-U addr and eNB info to sctp_proxy
Move all interaction with the `enb_registry` and `gtpu_kpi` modules
from `s1ap_proxy` to its parent process, `sctp_proxy`.  This prepares
for a follow-up change in which handling of the S1 SETUP procedure
will be fully migrated to `sctp_proxy` - a prerequisite for
proper MME pooling support.
Change-Id: I87e7d22a4bc5cb7816a167ac7dd29ea917594ce8
Related: SYS#7052
---
M src/s1ap_proxy.erl
M src/sctp_proxy.erl
M test/s1ap_proxy_test.erl
3 files changed, 78 insertions(+), 55 deletions(-)
Approvals:
  fixeria: Looks good to me, approved
  pespin: Looks good to me, but someone else must approve
  osmith: Looks good to me, but someone else must approve
  Jenkins Builder: Verified

diff --git a/src/s1ap_proxy.erl b/src/s1ap_proxy.erl
index b5abad5..8d765d4 100644
--- a/src/s1ap_proxy.erl
+++ b/src/s1ap_proxy.erl
@@ -40,7 +40,7 @@
          handle_call/3,
          handle_cast/2,
          terminate/2]).
--export([start_link/2,
+-export([start_link/1,
          process_pdu/2,
          fetch_erab/2,
          fetch_erab_list/1,
@@ -69,8 +69,7 @@
 -type plmn_id() :: {MCC :: nonempty_string(),
                     MNC :: nonempty_string()}.
--record(proxy_state, {conn_info :: sctp_server:conn_info(),
-                      enb_handle :: enb_registry:enb_handle(),
+-record(proxy_state, {owner :: pid(),
                       erabs :: dict:dict(K :: erab_uid(),
                                          V :: pid()),
                       enb_id :: undefined | non_neg_integer(),
@@ -100,12 +99,9 @@
 %% public API
 %% ------------------------------------------------------------------
--spec start_link(EnbHandle, ConnInfo) -> Result
-    when EnbHandle :: enb_registry:enb_handle(),
-         ConnInfo :: sctp_server:conn_info(),
-         Result :: gen_server:start_ret().
-start_link(EnbHandle, ConnInfo) ->
-    gen_server:start_link(?MODULE, [EnbHandle, ConnInfo], []).
+-spec start_link(pid()) -> gen_server:start_ret().
+start_link(Owner) ->
+    gen_server:start_link(?MODULE, [Owner], []).
-type process_pdu_result() :: {proxy_action(), binary()}.
@@ -141,11 +137,10 @@
 %% gen_server API
 %% ------------------------------------------------------------------
-init([EnbHandle, ConnInfo]) ->
+init([Owner]) ->
     process_flag(trap_exit, true),
-    {ok, #proxy_state{enb_handle = EnbHandle,
-                      conn_info = ConnInfo,
-                      erabs = dict:new(),
+    {ok, #proxy_state{erabs = dict:new(),
+                      owner = Owner,
                       path = []}}.
@@ -379,9 +374,7 @@
 handle_pdu({successfulOutcome,
             #'SuccessfulOutcome'{procedureCode = ?'id-S1Setup'}}, S) ->
     ?LOG_DEBUG("Processing S1 SETUP RESPONSE"),
-    enb_registry:enb_event(S#proxy_state.enb_handle,
-                           {s1setup, enb_info(S)}),
-    gtpu_kpi_enb_register(S),
+    signal_enb_info(S),
     %% there's nothing to patch in this PDU, so we forward it as-is
     {forward, S};
@@ -756,8 +749,8 @@
           #'E-RABSetupItemBearerSURes'{'e-RAB-ID' = ERABId,
                                        'transportLayerAddress' = TLA_In,
                                        'gTP-TEID' = << TEID_In:32/big >>} = C0, S) ->
-    %% indicate eNB's address to the gtpu_kpi module
-    gtpu_kpi_enb_set_addr({s1ap, tla_str(TLA_In)}),
+    %% signal eNB's GTP-U address to the parent process
+    signal_enb_addr(TLA_In, S),
     %% poke E-RAB FSM
     case erab_fsm_find(ERABId, S) of
         {ok, Pid} ->
@@ -1045,8 +1038,8 @@
           #'E-RABSetupItemCtxtSURes'{'e-RAB-ID' = ERABId,
                                      'transportLayerAddress' = TLA_In,
                                      'gTP-TEID' = << TEID_In:32/big >>} = C0, S) ->
-    %% indicate eNB's address to the gtpu_kpi module
-    gtpu_kpi_enb_set_addr({s1ap, tla_str(TLA_In)}),
+    %% signal eNB's GTP-U address to the parent process
+    signal_enb_addr(TLA_In, S),
     %% poke E-RAB FSM
     case erab_fsm_find(ERABId, S) of
         {ok, Pid} ->
@@ -1112,8 +1105,8 @@
           #'E-RABAdmittedItem'{'e-RAB-ID' = ERABId,
                                'transportLayerAddress' = TLA_In,
                                'gTP-TEID' = << TEID_In:32/big >>} = C0, S) ->
-    %% indicate eNB's address to the gtpu_kpi module
-    gtpu_kpi_enb_set_addr({s1ap, tla_str(TLA_In)}),
+    %% signal eNB's GTP-U address to the parent process
+    signal_enb_addr(TLA_In, S),
     %% poke E-RAB FSM
     case erab_fsm_find(ERABId, S) of
         {ok, Pid} ->
@@ -1245,37 +1238,19 @@
     dict:find(UID, ERABs).
--spec gtpu_kpi_enb_register(proxy_state()) -> ok.
-gtpu_kpi_enb_register(#proxy_state{conn_info = ConnInfo} = S) ->
-    %% register eNB using its Global-eNB-ID
-    ok = gtpu_kpi:enb_register(genb_id_str(S)),
-    %% indicate UL/DL addresses
-    EnbAddr = inet:ntoa(maps:get(addr, ConnInfo)),
-    gtpu_kpi_enb_set_addr({sctp, EnbAddr}).
-
-
--spec gtpu_kpi_enb_set_addr({Source, EnbAddr}) -> ok
-    when Source :: s1ap | sctp,
-         EnbAddr :: string().
-gtpu_kpi_enb_set_addr({Source, EnbAddr}) ->
-    gtpu_kpi_enb_set_addr(gtpu_kpi_ul_addr, {Source, ul, EnbAddr}),
-    gtpu_kpi_enb_set_addr(gtpu_kpi_dl_addr, {Source, dl, EnbAddr}),
+%% Signal the eNB's GTP-U address to the parent process
+-spec signal_enb_addr(binary(), proxy_state()) -> ok.
+signal_enb_addr(TLA, #proxy_state{owner = Pid}) ->
+    %% TODO: optimize to send this only once
+    Pid ! {?MODULE, {enb_addr, tla_str(TLA)}},
     ok.
--spec gtpu_kpi_enb_set_addr(EnvParam, {Source, ULDL, EnbAddr}) -> ok
-    when EnvParam :: atom(),
-         Source :: s1ap | sctp,
-         ULDL :: ul | dl,
-         EnbAddr :: string().
-gtpu_kpi_enb_set_addr(EnvParam, {Source, ULDL, EnbAddr}) ->
-    case osmo_s1gw:get_env(EnvParam, s1ap) of
-        Source ->
-            ?LOG_DEBUG("GTP-U KPI ~p address ~p learned from ~p",
-                       [ULDL, EnbAddr, Source]),
-            gtpu_kpi:enb_set_addr({ULDL, EnbAddr});
-        Mode ->
-            ?LOG_DEBUG("GTP-U KPI ~p address mode ~p != ~p", [ULDL, Mode, Source])
-    end.
+%% Signal eNB info to the parent process
+-spec signal_enb_info(proxy_state()) -> ok.
+signal_enb_info(#proxy_state{owner = Pid} = S) ->
+    Pid ! {?MODULE, {enb_info, enb_info(S)}},
+    ok.
+
%% vim:set ts=4 sw=4 et:
diff --git a/src/sctp_proxy.erl b/src/sctp_proxy.erl
index 0fbcbf5..60f0c11 100644
--- a/src/sctp_proxy.erl
+++ b/src/sctp_proxy.erl
@@ -69,6 +69,7 @@
                 tx_queue :: [binary()],
                 sock :: undefined | gen_sctp:sctp_socket(),
                 enb_handle :: enb_registry:enb_handle(),
+                genb_id_str :: undefined | string(),
                 handler :: pid() %% s1ap_proxy process' pid
                }).
@@ -110,7 +111,7 @@
init([EnbConnInfo, MmeConnCfg]) ->
     {ok, EnbHandle} = enb_registry:enb_register(),
-    {ok, Pid} = s1ap_proxy:start_link(EnbHandle, EnbConnInfo),
+    {ok, Pid} = s1ap_proxy:start_link(self()),
     {ok, connecting,
      #state{enb_aid = maps:get(aid, EnbConnInfo),
             enb_conn_info = EnbConnInfo,
@@ -209,6 +210,19 @@
     sctp_send_from_mme(Data, S),
     {keep_state, S};
+%% eNB info indication from s1ap_proxy
+connected(info, {s1ap_proxy, {enb_info, EnbInfo}},
+          #state{enb_handle = EnbHandle} = S0) ->
+    enb_registry:enb_event(EnbHandle, {s1setup, EnbInfo}),
+    S1 = S0#state{genb_id_str = maps:get(genb_id_str, EnbInfo)},
+    gtpu_kpi_enb_register(S1),
+    {keep_state, S1};
+
+%% eNB's GTP-U address indication from s1ap_proxy
+connected(info, {s1ap_proxy, {enb_addr, Addr}}, S) ->
+    gtpu_kpi_enb_set_addr({s1ap, Addr}),
+    {keep_state, S};
+
 connected(Event, EventData, S) ->
     handle_event(?FUNCTION_NAME, Event, EventData, S).
@@ -320,4 +334,40 @@
              mme_aid => S#state.mme_aid},
     maps:filter(fun(_K, V) -> V =/= undefined end, Info).
+
+-spec gtpu_kpi_enb_register(state()) -> ok.
+gtpu_kpi_enb_register(#state{genb_id_str = GlobalENBId,
+                             enb_conn_info = EnbConnInfo}) ->
+    %% register eNB using its Global-eNB-ID
+    ok = gtpu_kpi:enb_register(GlobalENBId),
+    %% indicate UL/DL addresses
+    EnbAddr = inet:ntoa(maps:get(addr, EnbConnInfo)),
+    gtpu_kpi_enb_set_addr({sctp, EnbAddr}).
+
+
+-spec gtpu_kpi_enb_set_addr({Source, EnbAddr}) -> ok
+    when Source :: s1ap | sctp,
+         EnbAddr :: string().
+gtpu_kpi_enb_set_addr({Source, EnbAddr}) ->
+    gtpu_kpi_enb_set_addr(gtpu_kpi_ul_addr, {Source, ul, EnbAddr}),
+    gtpu_kpi_enb_set_addr(gtpu_kpi_dl_addr, {Source, dl, EnbAddr}),
+    ok.
+
+
+-spec gtpu_kpi_enb_set_addr(EnvParam, {Source, ULDL, EnbAddr}) -> ok
+    when EnvParam :: atom(),
+         Source :: s1ap | sctp,
+         ULDL :: ul | dl,
+         EnbAddr :: string().
+gtpu_kpi_enb_set_addr(EnvParam, {Source, ULDL, EnbAddr}) ->
+    case osmo_s1gw:get_env(EnvParam, s1ap) of
+        Source ->
+            ?LOG_DEBUG("GTP-U KPI ~p address ~p learned from ~p",
+                       [ULDL, EnbAddr, Source]),
+            gtpu_kpi:enb_set_addr({ULDL, EnbAddr});
+        Mode ->
+            ?LOG_DEBUG("GTP-U KPI ~p address mode ~p != ~p", [ULDL, Mode, Source])
+    end.
+
+
 %% vim:set ts=4 sw=4 et:
diff --git a/test/s1ap_proxy_test.erl b/test/s1ap_proxy_test.erl
index 8e05b99..e376304 100644
--- a/test/s1ap_proxy_test.erl
+++ b/test/s1ap_proxy_test.erl
@@ -31,9 +31,7 @@
     enb_registry:start_link(),
     gtpu_kpi:start_link(#{enable => false}),
     {ok, EnbHandle} = enb_registry:enb_register(),
-    {ok, Pid} = s1ap_proxy:start_link(EnbHandle,
-                                      #{addr => {127,0,0,0},
-                                        port => 1337}),
+    {ok, Pid} = s1ap_proxy:start_link(self()),
     ok = enb_registry:enb_unregister(EnbHandle),
     #{handler => Pid}.
-- 
To view, visit https://gerrit.osmocom.org/c/erlang/osmo-s1gw/+/41619?usp=email
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Gerrit-MessageType: merged
Gerrit-Project: erlang/osmo-s1gw
Gerrit-Branch: master
Gerrit-Change-Id: I87e7d22a4bc5cb7816a167ac7dd29ea917594ce8
Gerrit-Change-Number: 41619
Gerrit-PatchSet: 2
Gerrit-Owner: fixeria vyanitskiy@sysmocom.de
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria vyanitskiy@sysmocom.de
Gerrit-Reviewer: osmith osmith@sysmocom.de
Gerrit-Reviewer: pespin pespin@sysmocom.de



    