Add a heartbeat_interval parameter to the pfcp_peer config section. When non-zero, pfcp_peer sends a periodic Heartbeat Request to the UPF at the configured interval using a named gen_statem timeout (hb_timer). The timer is started on entry to the connected state and cancelled on re-entry to the connecting state. Default is 10000 ms (10 seconds).
Reduce verbosity of the Tx/Rx Heartbeat Req/Resp log messages from LOG_INFO to LOG_DEBUG in preparation for periodic heartbeat support. Without this change, periodic heartbeats would flood the logging.
config/sys.config: group pfcp_peer params into a map
Following the same pattern as sctp_{client,server}, group the flat pfcp_loc_addr/pfcp_rem_addr environment variables into a pfcp_peer map. The old flat keys are still supported for backwards compat.
Changes: * osmo_s1gw_sup: add pfcp_cfg(), merging legacy flat keys with the new pfcp_peer map (new takes priority); store the resolved config back via set_env(pfcp_peer, ...) so all consumers see a single canonical map * pfcp_peer: change start_link/2 to start_link/1 taking a cfg() map; simplify init() using sctp_common:parse_addr/1; add cfg() type * rest_server: read pfcp laddr/raddr from the pfcp_peer map
pfcp_peer: make assoc_setup and heartbeat_req timeouts configurable
Add assoc_setup_timeout and heartbeat_req_timeout as optional fields in the pfcp_peer config map, with 2000 ms defaults. Store the full cfg() map in #peer_state{} and read values from it with maps:get/3 at the point of use.
The enb_proxy now captures the local address and port of the S1GW-MME SCTP connection (mme_saddr/mme_sport) at comm_up and includes them in conn_info(). Expose this info through the REST API (EnbItem schema), show it as a new column/row in the CLI (enb_list/enb_info).
The full enb_list table with all address columns is too wide to fit on a page and does not render well in PDF. Collapse the address columns with '...'; add a note that they are omitted for readability.
enb_{proxy,registry}: signal MME conn info on SCTP comm_up
Previously, mme_aid/mme_saddr/mme_sport were only signalled to the enb_registry once the S1 Setup procedure completed. This meant the REST API could not show MME connection details for eNBs stuck in wait_s1setup_rsp state (e.g. due to a slow or retrying MME).
Add notify_mme_comm_up/2, called at SCTP comm_up, which stores the full conn_info (including mme_aid, mme_saddr, mme_sport) in the registry as soon as the SCTP connection is established.
notify_mme_connected/2 is simplified to notify_mme_connected/1: it now only flips the state to 'connected', since conn_info is already stored.
enb_proxy: split conn_info() into mme_conn_info() and proxy_info()
The old conn_info() conflated two distinct concerns: the MME SCTP connection info stored in enb_registry (aid, saddr, sport) and the broader operational state used for introspection (handler pid, enb connection info, etc.). Mixing them forced enb_registry to hold a handler pid it has no business knowing about, and required rest_server to extract that pid just to reach s1ap_proxy for E-RAB listing.
Split into two distinct types:
* mme_conn_info() - pure MME SCTP connection info (aid, saddr, sport), stored in the enb_registry and signalled via notify_mme_comm_up/2. The `mme_` prefix is dropped from field names as the type name provides the context.
* proxy_info() - richer operational snapshot (handler, enb_handle, enb_conn_info, mme_conn_info, genb_id_str, mme_info), returned by fetch_info/1 for introspection/debugging purposes.
Additionally:
* Add fetch_erab_list/1 to enb_proxy, delegating internally to s1ap_proxy:fetch_erab_list/1 via the cached handler pid. This allows the rest_server to obtain a list of E-RAB without having to obtain pid of the s1ap_proxy and interact with it.
* Remove separate enb_aid/mme_aid/mme_saddr/mme_sport state fields; enb_aid is now read directly from enb_conn_info, and the MME fields are grouped in mme_conn_info.
As a bonus, `tried_mmes` now only serves its actual purpose - tracking which MMEs have already been tried for selection filtering - rather than being abused as a way to retrieve the current MME name.
rest_server: fix TOC/TOU race when listing/fetching E-RABs
The list of E-RAB FSM pids is a snapshot taken at one point in time. By the time we interrogate each erab_fsm process individually, any of them may have already terminated (e.g. bearer released mid-request). The current code fails to generate a response if this happens.
* fetch_erab_info/1: add a pid() clause that wraps erab_list_item/1 in a try/catch, returning 'error' if the process is gone.
* fetch_erab_info/1: catch both exit forms ** `{noproc, _}` raised by gen_statem:call/2 on a monitored pid, and ** the bare noproc atom for other code paths.
* fetch_erab_list/1: switch from lists:map to lists:filtermap and call fetch_erab_info/1 per E-RAB, silently dropping any that died between the snapshot and the per-process interrogation.
The new version is using ETS instead of dict for counter lookups. This significantly reduces performance impact when multiple eNBs are registered, since the ETS provides O(1) average-case hash lookups and in-place mutation.
config/sys.config: increase StatsD reporter interval to 10s
When running ttcn3-s1gw-test locally, I noticed OsmoS1GW consuming 30-40% of a CPU core while idle (not serving any eNBs). Profiling with etop pointed to `exometer_report_statsd` as the culprit: with ~1720 metrics registered, it was sending ~1720 datagrams per second.
A 1-second reporting interval causes noticeable CPU overhead as the number of active metrics grows. With per-eNB and per-MME counters, the metric set scales with the number of connected eNBs/MMEs.
Increase the default StatsD reporting interval from 1s to 10s to reduce that overhead. Update the documentation accordingly.
When an MME is selected from the pool, pass the mme_registry:mme_info() to the enb_registry via notify_mme_connecting/2 (replacing /1). This makes all MME configuration details (name, address, port, TAC list) available to consumers such as the REST server, without having to look them up separately from the mme_registry.
enb_proxy: obtain sctp_client sockopts from the env directly
Instead of passing the MmeConnCfg (sctp_client:cfg()) all the way from osmo_s1gw_sup through sctp_server (as priv) into enb_proxy (as state), read the sctp_client configuration in-place via osmo_s1gw:get_env/2 when it is actually needed (connecting/enter).
This works because osmo_s1gw_sup already normalizes and writes back the complete sctp_client config to the application env (set_env/2) before starting the supervision tree.
As a result, mme_conn_cfg is removed from enb_proxy's state record, start_link/2 no longer uses its Priv argument, and server_cfg/1 is simplified to server_cfg/0.
This endpoint returns the effective runtime configuration that OsmoS1GW is currently using, with all defaults applied. This reflects the values read via `osmo_s1gw:get_env/2` at startup.
Add support for selecting an MME or eNB by remote address and port in the REST API and CLI. The selector format is `addr:IP:PORT` for MMEs and `enb-conn:IP:PORT` for eNBs, where IP can be an IPv4 or IPv6 address. The colon is used as the address/port separator.
For each eNB connection, include the name of the MME that was selected from the pool. Update the OpenAPI spec, CLI (enb_list/enb_info tables), and user manual accordingly.
mme_registry: add backwards compat for old sctp_client config
When 'mme_pool' is absent from the config, automatically populate the MME pool with a single 'default' entry derived from the 'sctp_client' section (including legacy mme_loc_addr/mme_rem_addr params), and emit a deprecation warning. osmo_s1gw_sup:init/1 normalises 'sctp_client' in the app env (with all defaults applied) before children start, so mme_registry can safely read it without duplicating the parsing logic.
Rework the CONNECTING state to dynamically select an MME from the pool via mme_registry:mme_select/1, passing the eNB's Tracking Area Codes (from the ?'id-SupportedTAs' IE of the S1 SETUP REQUEST) and a list of already-tried MMEs, so successive attempts pick a different candidate.
On connection failure (SCTP establishment timeout or error), or when the selected MME rejects the S1 SETUP REQUEST or fails to respond in time, the FSM re-enters the CONNECTING state rather than terminating. This triggers another mme_select/1 call with the failed MME added to the tried_mmes list. S1 SETUP FAILURE PDUs from the MME are intentionally not forwarded to the eNB, so the retry is fully transparent.
Once mme_select/1 exhausts all candidates it returns 'error'; at that point the FSM builds and sends an S1 SETUP FAILURE PDU to the eNB and terminates.
enb_proxy: fix stale SCTP events misprocessed during MME pool selection
When closing a connection to one MME and opening a new one to the next, a SHUTDOWN_COMP event from the old (now-closed) socket can still be pending in the process mailbox. The sctp_assoc_change handlers in the 'connecting' and 'wait_s1setup_rsp' states were matching '_Socket', ignoring the socket identity. A stale SHUTDOWN_COMP would therefore fall into the '_ -> repeat_state_and_data' branch, triggering a spurious re-entry of 'connecting', which immediately closed the newly established connection to the next MME and skipped to yet another pool entry.
Fix this by matching the Socket against the current S#state.sock in both handlers. Events arriving on a previously closed socket no longer match these clauses and are silently dropped by the catch-all handle_event/4.
This was found thanks to the MME pooling TCs in ttcn3-s1gw-test.
