fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/erlang/osmo-s1gw/+/41622?usp=email )
Change subject: s1ap_proxy: move S1 SETUP handling to sctp_proxy ......................................................................
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(-)
git pull ssh://gerrit.osmocom.org:29418/erlang/osmo-s1gw refs/changes/22/41622/1
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}.
-
fixeria