fixeria submitted this change.
s1ap_proxy: move S1 SETUP handling to sctp_proxy
This is a prerequisite for the MME pooling support. We need to receive
the S1 SETUP REQUEST PDU, extract the Global-eNB-ID and TAC(s), and use
this information to select an appropriate MME. The PDU must also be
cached so it can be sent (or re-sent) to the selected MME(s).
The s1ap_proxy module no longer needs to parse S1 SETUP PDUs, as this
logic has been moved to the sctp_proxy and implemented using the newly
introduced s1ap_utils API. However, s1ap_proxy still requires the
Global-eNB-ID for logging and per-eNB counters, so sctp_proxy now
provides it through the new s1ap_proxy:set_genb_id/2 API.
Change-Id: I9aa67732b418bcdf3f10b2db89a41dda26ee3d4e
Related: SYS#7052
---
M src/enb_registry.erl
M src/s1ap_proxy.erl
M src/sctp_proxy.erl
M test/s1ap_proxy_test.erl
4 files changed, 151 insertions(+), 113 deletions(-)
diff --git a/src/enb_registry.erl b/src/enb_registry.erl
index 90c3376..80d264b 100644
--- a/src/enb_registry.erl
+++ b/src/enb_registry.erl
@@ -65,7 +65,7 @@
-type enb_event() :: {connecting, sctp_server:conn_info()}
| {connected, sctp_proxy:conn_info()}
- | {s1setup, s1ap_proxy:enb_info()}.
+ | {s1setup, s1ap_utils:genb_id()}.
-type enb_filter() :: {genb_id_str, string()}
| {enb_sctp_aid, gen_sctp:assoc_id()}
@@ -79,9 +79,8 @@
state := enb_state(), %% connection state
reg_time := integer(), %% registration time (monotonic)
uptime := non_neg_integer(), %% seconds since reg_time
- genb_id_str => string(), %% Global-eNB-ID
- enb_id => s1ap_utils:enb_id(), %% eNB-ID
- plmn_id => s1ap_utils:plmn_id(), %% PLMN-ID
+ genb_id => s1ap_utils:genb_id(), %% Global-eNB-ID
+ genb_id_str => string(), %% Global-eNB-ID string
enb_conn_info => sctp_server:conn_info(), %% eNB -> S1GW connection info
mme_conn_info => sctp_proxy:conn_info() %% S1GW -> MME connection info
}.
@@ -307,8 +306,10 @@
EnbInfo#{state => connected,
mme_conn_info => ConnInfo};
-enb_handle_event(EnbInfo, {s1setup, Info}) ->
- maps:merge(EnbInfo#{state => s1setup}, Info);
+enb_handle_event(EnbInfo, {s1setup, GENBId}) ->
+ EnbInfo#{state => s1setup,
+ genb_id => GENBId,
+ genb_id_str => s1ap_utils:genb_id_str(GENBId)};
enb_handle_event(EnbInfo, Event) ->
?LOG_ERROR("Unhandled event: ~p", [Event]),
diff --git a/src/s1ap_proxy.erl b/src/s1ap_proxy.erl
index 43624d2..0903906 100644
--- a/src/s1ap_proxy.erl
+++ b/src/s1ap_proxy.erl
@@ -41,6 +41,7 @@
handle_cast/2,
terminate/2]).
-export([start_link/1,
+ set_genb_id/2,
process_pdu/2,
fetch_erab/2,
fetch_erab_list/1,
@@ -68,8 +69,6 @@
-record(proxy_state, {owner :: pid(),
erabs :: dict:dict(K :: erab_uid(),
V :: pid()),
- enb_id :: undefined | s1ap_utils:enb_id(),
- plmn_id :: undefined | s1ap_utils:plmn_id(),
genb_id_str :: undefined | string(),
mme_ue_id :: undefined | mme_ue_id(),
enb_ue_id :: undefined | enb_ue_id(),
@@ -80,13 +79,7 @@
-type proxy_state() :: #proxy_state{}.
-type proxy_action() :: forward | reply | drop.
--type enb_info() :: #{enb_id => s1ap_utils:enb_id(),
- plmn_id => s1ap_utils:plmn_id(),
- genb_id_str => string()
- }.
-
--export_type([proxy_action/0,
- enb_info/0]).
+-export_type([proxy_action/0]).
%% ------------------------------------------------------------------
@@ -98,6 +91,11 @@
gen_server:start_link(?MODULE, [Owner], []).
+-spec set_genb_id(pid(), string()) -> ok | {error, term()}.
+set_genb_id(Pid, GlobalENBId) ->
+ gen_server:call(Pid, {?FUNCTION_NAME, GlobalENBId}).
+
+
-type process_pdu_result() :: {proxy_action(), binary()}.
-spec process_pdu(pid(), binary()) -> process_pdu_result().
process_pdu(Pid, PDU) ->
@@ -145,6 +143,20 @@
#proxy_state{erabs = ERABs} = S) ->
{reply, dict:to_list(ERABs), S};
+handle_call({set_genb_id, GlobalENBId}, _From,
+ #proxy_state{genb_id_str = undefined} = S) ->
+ ?LOG_DEBUG("Global-eNB-ID is set: ~s", [GlobalENBId]),
+ %% use that as a context for logging
+ osmo_s1gw:set_log_prefix("eNB " ++ GlobalENBId),
+ %% register per-eNB metrics
+ ctr_reg_all(GlobalENBId),
+ {reply, ok, S#proxy_state{genb_id_str = GlobalENBId}};
+
+handle_call({set_genb_id, _GlobalENBId}, _From,
+ #proxy_state{genb_id_str = GlobalENBId} = S) ->
+ ?LOG_ERROR("Global-eNB-ID is already set: ~s", [GlobalENBId]),
+ {reply, {error, ealready}, S};
+
handle_call(Info, From,
#proxy_state{} = S) ->
?LOG_ERROR("unknown ~p() from ~p: ~p", [?FUNCTION_NAME, From, Info]),
@@ -198,15 +210,6 @@
ok.
--spec enb_info(proxy_state()) -> enb_info().
-enb_info(S) ->
- Info = #{enb_id => S#proxy_state.enb_id,
- plmn_id => S#proxy_state.plmn_id,
- genb_id_str => S#proxy_state.genb_id_str},
- %% omit fields with Value =:= undefined
- maps:filter(fun(_K, V) -> V =/= undefined end, Info).
-
-
%% register a single per-eNB counter
-spec ctr_reg(C, GlobalENBId) -> C
when C :: [ctr | _],
@@ -308,25 +311,6 @@
S1 :: proxy_state(),
Result :: {forward | reply, s1ap_utils:s1ap_pdu()} | forward | drop.
-%% 9.1.8.4 S1 SETUP REQUEST
-handle_pdu({initiatingMessage,
- #'InitiatingMessage'{procedureCode = ?'id-S1Setup',
- value = C0}}, S0) ->
- ?LOG_DEBUG("Processing S1 SETUP REQUEST"),
- %% there's nothing to patch in this PDU, so we forward it as-is
- %% TODO: check result of handle_ies(), inc. ?S1GW_CTR_S1AP_PROXY_IN_PKT_PROC_ERROR
- {_, S1} = handle_ies(?'id-Global-ENB-ID',
- C0#'S1SetupRequest'.protocolIEs, S0),
- {forward, S1};
-
-%% 9.1.8.5 S1 SETUP RESPONSE
-handle_pdu({successfulOutcome,
- #'SuccessfulOutcome'{procedureCode = ?'id-S1Setup'}}, S) ->
- ?LOG_DEBUG("Processing S1 SETUP RESPONSE"),
- signal_enb_info(S),
- %% there's nothing to patch in this PDU, so we forward it as-is
- {forward, S};
-
%% 9.1.3.1 E-RAB SETUP REQUEST
handle_pdu({Outcome = initiatingMessage,
@@ -642,32 +626,6 @@
Result :: {handle_ie_result(),
proxy_state()}.
-handle_ie([?'id-Global-ENB-ID'],
- #'Global-ENB-ID'{'pLMNidentity' = PLMNId,
- 'eNB-ID' = ENBId} = C, S0) ->
- %% store PLMNId/ENBId
- S1 = S0#proxy_state{plmn_id = s1ap_utils:parse_plmn_id(PLMNId),
- enb_id = s1ap_utils:parse_enb_id(ENBId)},
- ?LOG_INFO("Global-ENB-ID: PLMN-ID=~p, eNB-ID=~p",
- [S1#proxy_state.plmn_id,
- S1#proxy_state.enb_id]),
- %% use that as a context for logging
- GlobalENBId = s1ap_utils:genb_id_str(#{plmn_id => S1#proxy_state.plmn_id,
- enb_id => S1#proxy_state.enb_id}),
- osmo_s1gw:set_log_prefix("eNB " ++ GlobalENBId),
- %% register per-eNB metrics
- ctr_reg_all(GlobalENBId),
- %% increment per-eNB ?S1GW_CTR_S1AP_PROXY_IN_PKT_ALL, if needed
- %% this is needed to count S1 Setup Req correctly
- S2 = case S0#proxy_state.genb_id_str of
- GlobalENBId -> S1;
- _ ->
- Ctr = s1gw_metrics:enb_metric(?S1GW_CTR_S1AP_PROXY_IN_PKT_ALL, GlobalENBId),
- s1gw_metrics:ctr_inc(Ctr),
- S1#proxy_state{genb_id_str = GlobalENBId}
- end,
- {{ok, C}, S2};
-
%% E-RAB SETUP REQUEST related IEs
handle_ie([?'id-E-RABToBeSetupListBearerSUReq'], C, S) ->
%% This IE contains a list of BearerSUReq, so patch inner IEs
@@ -1196,11 +1154,4 @@
ok.
-%% 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 60f0c11..305d7d7 100644
--- a/src/sctp_proxy.erl
+++ b/src/sctp_proxy.erl
@@ -1,4 +1,4 @@
-%% Copyright (C) 2024 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+%% Copyright (C) 2024-2025 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
%% Author: Vadim Yanitskiy <vyanitskiy@sysmocom.de>
%%
%% All Rights Reserved
@@ -38,6 +38,8 @@
-export([init/1,
callback_mode/0,
+ wait_s1setup_req/3,
+ wait_s1setup_rsp/3,
connecting/3,
connected/3,
code_change/4,
@@ -53,6 +55,8 @@
-include("s1gw_metrics.hrl").
+-include("S1AP-Constants.hrl").
+
-type conn_info() :: #{state := atom(),
handler := pid(),
@@ -66,7 +70,7 @@
mme_aid :: undefined | gen_sctp:assoc_id(),
enb_conn_info :: sctp_server:conn_info(),
mme_conn_cfg :: sctp_client:cfg(),
- tx_queue :: [binary()],
+ s1setup_req :: undefined | binary(),
sock :: undefined | gen_sctp:sctp_socket(),
enb_handle :: enb_registry:enb_handle(),
genb_id_str :: undefined | string(),
@@ -111,12 +115,12 @@
init([EnbConnInfo, MmeConnCfg]) ->
{ok, EnbHandle} = enb_registry:enb_register(),
+ enb_registry:enb_event(EnbHandle, {connecting, EnbConnInfo}),
{ok, Pid} = s1ap_proxy:start_link(self()),
- {ok, connecting,
+ {ok, wait_s1setup_req,
#state{enb_aid = maps:get(aid, EnbConnInfo),
enb_conn_info = EnbConnInfo,
mme_conn_cfg = MmeConnCfg,
- tx_queue = [],
enb_handle = EnbHandle,
handler = Pid}}.
@@ -125,13 +129,50 @@
[state_functions, state_enter].
+%% WAIT_S1SETUP_REQ state
+wait_s1setup_req(enter, _OldState, S) ->
+ ?LOG_INFO("State enter: ~p", [?FUNCTION_NAME]),
+ {next_state, ?FUNCTION_NAME, S,
+ [{state_timeout, 5_000, s1setup_req_timeout}]};
+
+%% Handle S1 SETUP REQUEST timeout
+wait_s1setup_req(state_timeout, s1setup_req_timeout, _S) ->
+ ?LOG_ERROR("Timeout waiting for S1 SETUP REQUEST from eNB"),
+ {stop, {shutdown, s1setup_req_timeout}};
+
+%% Handle PDUs coming from the eNB
+wait_s1setup_req(cast, {send_data, Data}, S) ->
+ ?LOG_DEBUG("Rx S1AP PDU from eNB: ~p", [Data]),
+ case s1ap_utils:parse_pdu(Data) of
+ {{?'id-S1Setup', initiatingMessage}, IEs} ->
+ %% fetch the Global-eNB-ID IE, convert it to a string
+ GENBId = proplists:get_value(?'id-Global-ENB-ID', IEs),
+ GlobalENBId = s1ap_utils:genb_id_str(GENBId),
+ %% use it as the logging prefix
+ osmo_s1gw:set_log_prefix("eNB " ++ GlobalENBId),
+ ?LOG_INFO("Rx S1 SETUP REQUEST from eNB"),
+ %% signal the Global-eNB-ID to other modules
+ s1ap_proxy:set_genb_id(S#state.handler, GlobalENBId),
+ enb_registry:enb_event(S#state.enb_handle, {s1setup, GENBId}),
+ gtpu_kpi_enb_register(S#state{genb_id_str = GlobalENBId}),
+ {next_state, connecting,
+ S#state{s1setup_req = Data,
+ genb_id_str = GlobalENBId}};
+ {{Proc, Type}, IEs} ->
+ ?LOG_ERROR("Rx unexpected S1AP PDU from eNB: ~p/~p, ~p", [Proc, Type, IEs]),
+ {stop, {shutdown, s1setup_error}};
+ {error, _Error} ->
+ {stop, {shutdown, s1setup_error}}
+ end;
+
+wait_s1setup_req(Event, EventData, S) ->
+ handle_event(?FUNCTION_NAME, Event, EventData, S).
+
+
%% CONNECTING state
connecting(enter, OldState,
- #state{enb_conn_info = EnbConnInfo,
- mme_conn_cfg = MmeConnCfg,
- enb_handle = Handle} = S) ->
+ #state{mme_conn_cfg = MmeConnCfg} = S) ->
?LOG_INFO("State change: ~p -> ~p", [OldState, ?FUNCTION_NAME]),
- ok = enb_registry:enb_event(Handle, {?FUNCTION_NAME, EnbConnInfo}),
%% Initiate connection establishment with the MME
{ok, Sock} = sctp_client:connect(MmeConnCfg),
%% loop transition to enable state_timeout
@@ -142,12 +183,10 @@
connecting(state_timeout, conn_est_timeout, _S) ->
{stop, {shutdown, conn_est_timeout}};
-%% Handle an eNB -> MME data forwarding request (queue)
-connecting(cast, {send_data, Data},
- #state{tx_queue = Pending} = S) ->
- s1gw_metrics:ctr_inc(?S1GW_CTR_S1AP_PROXY_UPLINK_PACKETS_QUEUED),
- s1gw_metrics:gauge_inc(?S1GW_GAUGE_S1AP_PROXY_UPLINK_PACKETS_QUEUED),
- {keep_state, S#state{tx_queue = [Data | Pending]}};
+%% Handle PDUs coming from the eNB
+connecting(cast, {send_data, Data}, _S) ->
+ ?LOG_ERROR("Rx unexpected S1AP PDU from eNB: ~p", [Data]),
+ keep_state_and_data;
%% Handle an #sctp_assoc_change event (connection state)
connecting(info, {sctp, _Socket, MmeAddr, MmePort,
@@ -157,7 +196,10 @@
comm_up ->
?LOG_NOTICE("MME connection (id=~p, ~p:~p) established",
[Aid, MmeAddr, MmePort]),
- {next_state, connected, S#state{mme_aid = Aid}};
+ %% send the S1 SETUP REQUEST PDU to the MME
+ sctp_send_from_enb(S#state.s1setup_req,
+ S#state{mme_aid = Aid}),
+ {next_state, wait_s1setup_rsp, S#state{mme_aid = Aid}};
_ ->
?LOG_NOTICE("MME connection establishment failed: ~p", [ConnState]),
{stop, {shutdown, conn_est_fail}}
@@ -167,15 +209,75 @@
handle_event(?FUNCTION_NAME, Event, EventData, S).
+%% WAIT_S1SETUP_RSP state
+wait_s1setup_rsp(enter, OldState, S) ->
+ ?LOG_INFO("State change: ~p -> ~p", [OldState, ?FUNCTION_NAME]),
+ {next_state, ?FUNCTION_NAME, S,
+ [{state_timeout, 5_000, s1setup_rsp_timeout}]};
+
+%% Handle S1 SETUP RESPONSE timeout
+wait_s1setup_rsp(state_timeout, s1setup_rsp_timeout, _S) ->
+ ?LOG_ERROR("Timeout waiting for S1 SETUP RESPONSE from MME"),
+ {stop, {shutdown, s1setup_rsp_timeout}};
+
+%% Handle PDUs coming from the eNB
+wait_s1setup_rsp(cast, {send_data, Data}, _S) ->
+ ?LOG_ERROR("Rx unexpected S1AP PDU from eNB: ~p", [Data]),
+ keep_state_and_data;
+
+%% Handle PDUs coming from the MME
+wait_s1setup_rsp(info, {sctp, _Socket, MmeAddr, MmePort,
+ {[#sctp_sndrcvinfo{assoc_id = MmeAid,
+ stream = SID,
+ ssn = SSN,
+ tsn = TSN}], Data}},
+ #state{mme_aid = MmeAid} = S) ->
+ ?LOG_DEBUG("MME connection (id=~p, ~p:~p) -> eNB: ~p",
+ [MmeAid, MmeAddr, MmePort,
+ #{tsn => TSN, sid => SID, ssn => SSN,
+ len => byte_size(Data), data => Data}]),
+ case s1ap_utils:parse_pdu(Data) of
+ {{?'id-S1Setup', successfulOutcome}, _IEs} ->
+ ?LOG_INFO("Rx S1 SETUP RESPONSE from MME"),
+ sctp_send_from_mme(Data, S),
+ {next_state, connected, S};
+ {{?'id-S1Setup', unsuccessfulOutcome}, _IEs} ->
+ ?LOG_NOTICE("Rx S1 SETUP FAILURE from MME"),
+ sctp_send_from_mme(Data, S),
+ {stop, {shutdown, s1setup_error}};
+ {{Proc, Type}, IEs} ->
+ ?LOG_ERROR("Rx unexpected S1AP PDU from MME: ~p/~p, ~p", [Proc, Type, IEs]),
+ {stop, {shutdown, s1setup_error}};
+ {error, _Error} ->
+ {stop, {shutdown, s1setup_error}}
+ end;
+
+%% Handle an #sctp_assoc_change event (MME connection state)
+%% We may loose connection while waiting for the S1 SETUP RESPONSE
+wait_s1setup_rsp(info, {sctp, _Socket, MmeAddr, MmePort,
+ {[], #sctp_assoc_change{state = ConnState,
+ assoc_id = Aid}}}, S) ->
+ case ConnState of
+ comm_up ->
+ ?LOG_NOTICE("MME connection (id=~p, ~p:~p) is already established?!?",
+ [Aid, MmeAddr, MmePort]),
+ {keep_state, S};
+ _ ->
+ ?LOG_NOTICE("MME connection state: ~p", [ConnState]),
+ {stop, {shutdown, conn_fail}}
+ end;
+
+wait_s1setup_rsp(Event, EventData, S) ->
+ handle_event(?FUNCTION_NAME, Event, EventData, S).
+
+
%% CONNECTED state
connected(enter, OldState,
- #state{enb_handle = Handle} = S0) ->
+ #state{enb_handle = Handle} = S) ->
?LOG_INFO("State change: ~p -> ~p", [OldState, ?FUNCTION_NAME]),
- MmeConnInfo = conn_info(?FUNCTION_NAME, S0),
+ MmeConnInfo = conn_info(?FUNCTION_NAME, S),
ok = enb_registry:enb_event(Handle, {?FUNCTION_NAME, MmeConnInfo}),
- %% Send pending eNB -> MME messages (if any)
- S1 = sctp_send_pending(S0),
- {keep_state, S1};
+ {keep_state, S};
%% Handle an eNB -> MME data forwarding request (forward)
connected(cast, {send_data, Data}, S0) ->
@@ -210,14 +312,6 @@
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}),
@@ -315,15 +409,6 @@
end.
-%% Send pending messages to the MME
--spec sctp_send_pending(state()) -> state().
-sctp_send_pending(#state{tx_queue = Pending} = S) ->
- [] = lists:filter(fun(Data) -> sctp_send_from_enb(Data, S) =/= ok end,
- lists:reverse(Pending)),
- s1gw_metrics:gauge_set(?S1GW_GAUGE_S1AP_PROXY_UPLINK_PACKETS_QUEUED, 0),
- S#state{tx_queue = []}.
-
-
-spec conn_info(atom(), state()) -> conn_info().
conn_info(State, #state{mme_conn_cfg = MmeConnCfg} = S) ->
Info = #{state => State,
diff --git a/test/s1ap_proxy_test.erl b/test/s1ap_proxy_test.erl
index e376304..2d748bf 100644
--- a/test/s1ap_proxy_test.erl
+++ b/test/s1ap_proxy_test.erl
@@ -32,6 +32,7 @@
gtpu_kpi:start_link(#{enable => false}),
{ok, EnbHandle} = enb_registry:enb_register(),
{ok, Pid} = s1ap_proxy:start_link(self()),
+ s1ap_proxy:set_genb_id(Pid, ?GlobalENBId),
ok = enb_registry:enb_unregister(EnbHandle),
#{handler => Pid}.
To view, visit change 41622. To unsubscribe, or for help writing mail filters, visit settings.