/* FSM to manage multiple connections of an MGW endpoint * * (C) 2018-2019 by sysmocom - s.f.m.c. GmbH * All Rights Reserved * * Author: Neels Hofmeyr * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see . * */ #include #include #include #include #include #include #include #include #define LOG_CI(ci, level, fmt, args...) do { \ if (!ci || !ci->ep) \ LOGP(DLMGCP, level, "(unknown MGW endpoint) " fmt, ## args); \ else \ LOG_MGCPC_EP(ci->ep, level, "CI[%d] %s%s%s: " fmt, \ (int)(ci - ci->ep->ci), \ ci->label ? : "-", \ ci->mgcp_ci_str[0] ? " CI=" : "", \ ci->mgcp_ci_str[0] ? ci->mgcp_ci_str : "", \ ## args); \ } while(0) #define LOG_CI_VERB(ci, level, fmt, args...) do { \ if (ci->verb_info.addr[0]) \ LOG_CI(ci, level, "%s %s:%u: " fmt, \ osmo_mgcp_verb_name(ci->verb), ci->verb_info.addr, ci->verb_info.port, \ ## args); \ else \ LOG_CI(ci, level, "%s: " fmt, \ osmo_mgcp_verb_name(ci->verb), \ ## args); \ } while(0) enum osmo_mgcpc_ep_fsm_state { OSMO_MGCPC_EP_ST_UNUSED = 0, OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE, OSMO_MGCPC_EP_ST_IN_USE, }; enum osmo_mgcpc_ep_fsm_event { _OSMO_MGCPC_EP_EV_LAST = 0, /* and MGW response events are allocated dynamically */ }; #define FIRST_CI_EVENT (_OSMO_MGCPC_EP_EV_LAST + (_OSMO_MGCPC_EP_EV_LAST & 1)) /* rounded up to even nr */ #define USABLE_CI ((32 - FIRST_CI_EVENT)/2) #define EV_TO_CI_IDX(event) ((event - FIRST_CI_EVENT) / 2) #define CI_EV_SUCCESS(ci) (FIRST_CI_EVENT + (((ci) - ci->ep->ci) * 2)) #define CI_EV_FAILURE(ci) (CI_EV_SUCCESS(ci) + 1) static struct osmo_fsm osmo_mgcpc_ep_fsm; struct fsm_notify { struct llist_head entry; struct osmo_fsm_inst *fi; uint32_t success; uint32_t failure; void *data; }; /*! One connection on an endpoint, corresponding to a connection identifier (CI) as returned by the MGW. * An endpoint has a fixed number of slots of these, which may or may not be in use. */ struct osmo_mgcpc_ep_ci { struct osmo_mgcpc_ep *ep; bool occupied; char label[64]; struct osmo_fsm_inst *mgcp_client_fi; bool pending; bool sent; enum mgcp_verb verb; struct mgcp_conn_peer verb_info; struct fsm_notify notify; bool got_port_info; struct mgcp_conn_peer rtp_info; char mgcp_ci_str[MGCP_CONN_ID_LENGTH]; }; /*! An MGW endpoint with N connections, like "rtpbridge/23@mgw". */ struct osmo_mgcpc_ep { /*! MGCP client connection to the MGW. */ struct mgcp_client *mgcp_client; struct osmo_fsm_inst *fi; /*! Endpoint string; at first this might be a wildcard, and upon the first CRCX OK response, this will reflect * the endpoint name returned by the MGW. */ char endpoint[MGCP_ENDPOINT_MAXLEN]; /*! Timeout definitions used for this endpoint, see osmo_mgcpc_ep_fsm_timeouts. */ const struct osmo_tdef *T_defs; /*! True as soon as the first CRCX OK is received. The endpoint name may be determined by the first CRCX * response, so to dispatch any other messages, the FSM instance *must* wait for the first CRCX OK to arrive * first. Once the endpoint name is pinpointed, any amount of operations may be dispatched concurrently. */ bool first_crcx_complete; /*! Endpoint connection slots. Note that each connection has its own set of FSM event numbers to signal success * and failure, depending on its index within this array. See CI_EV_SUCCESS and CI_EV_FAILURE. */ struct osmo_mgcpc_ep_ci ci[USABLE_CI]; /*! Internal use: if a function keeps an fsm_notify for later dispatch while already clearing or re-using the * ci[], the fsm_notify should be kept here to also get canceled by osmo_mgcpc_ep_cancel_notify(). */ struct llist_head background_notify; }; const struct value_string osmo_mgcp_verb_names[] = { { MGCP_VERB_CRCX, "CRCX" }, { MGCP_VERB_MDCX, "MDCX" }, { MGCP_VERB_DLCX, "DLCX" }, { MGCP_VERB_AUEP, "AUEP" }, { MGCP_VERB_RSIP, "RSIP" }, {} }; static void osmo_mgcpc_ep_count(struct osmo_mgcpc_ep *ep, int *occupied, int *pending_not_sent, int *waiting_for_response); static struct osmo_mgcpc_ep_ci *osmo_mgcpc_ep_check_ci(struct osmo_mgcpc_ep_ci *ci) { if (!ci) return NULL; if (!ci->ep) return NULL; if (ci < ci->ep->ci || ci >= &ci->ep->ci[USABLE_CI]) return NULL; return ci; } static struct osmo_mgcpc_ep_ci *osmo_mgcpc_ep_ci_for_event(struct osmo_mgcpc_ep *ep, uint32_t event) { int idx; if (event < FIRST_CI_EVENT) return NULL; idx = EV_TO_CI_IDX(event); if (idx >= sizeof(ep->ci)) return NULL; return osmo_mgcpc_ep_check_ci(&ep->ci[idx]); } const char *osmo_mgcpc_ep_name(const struct osmo_mgcpc_ep *ep) { if (!ep) return "NULL"; if (ep->endpoint[0]) return ep->endpoint; return osmo_fsm_inst_name(ep->fi); } /*! Get "local endpoint name" part of the endpoint name: (local-endpoint-name@domain-name) * * \param ep The MGCP Endpoint * \returns the local endpoint name if found, NULL on error. */ const char *osmo_mgcpc_ep_local_name(const struct osmo_mgcpc_ep *ep) { static char buf[1024]; const char *sep; OSMO_ASSERT(ep); sep = strchr(ep->endpoint, '@'); if (!sep) { OSMO_STRLCPY_ARRAY(buf, ep->endpoint); return buf; } if (sep - ep->endpoint >= sizeof(buf)) return NULL; memcpy(buf, ep->endpoint, sep - ep->endpoint); buf[sep - ep->endpoint] = '\0'; return buf; } const char *mgcp_conn_peer_name(const struct mgcp_conn_peer *info) { /* I'd be fine with a smaller buffer and accept truncation, but gcc possibly refuses to build if * this buffer is too small. */ static char buf[1024]; if (!info) return "NULL"; if (info->endpoint[0] && info->addr[0]) snprintf(buf, sizeof(buf), "%s:%s:%u", info->endpoint, info->addr, info->port); else if (info->endpoint[0]) snprintf(buf, sizeof(buf), "%s", info->endpoint); else if (info->addr[0]) snprintf(buf, sizeof(buf), "%s:%u", info->addr, info->port); else return "empty"; return buf; } const char *osmo_mgcpc_ep_ci_name(const struct osmo_mgcpc_ep_ci *ci) { const struct mgcp_conn_peer *rtp_info; if (!ci) return "NULL"; rtp_info = osmo_mgcpc_ep_ci_get_rtp_info(ci); if (rtp_info) return mgcp_conn_peer_name(rtp_info); return osmo_mgcpc_ep_name(ci->ep); } const char *osmo_mgcpc_ep_ci_id(const struct osmo_mgcpc_ep_ci *ci) { if (!ci || !ci->mgcp_ci_str[0]) return NULL; return ci->mgcp_ci_str; } struct mgcp_client *osmo_mgcpc_ep_client(const struct osmo_mgcpc_ep *ep) { if (!ep) return NULL; return ep->mgcp_client; } static struct value_string osmo_mgcpc_ep_fsm_event_names[33] = {}; static char osmo_mgcpc_ep_fsm_event_name_bufs[32][32] = {}; static void fill_event_names(void) { int i; for (i = 0; i < (ARRAY_SIZE(osmo_mgcpc_ep_fsm_event_names) - 1); i++) { if (i < _OSMO_MGCPC_EP_EV_LAST) continue; if (i < FIRST_CI_EVENT || EV_TO_CI_IDX(i) > USABLE_CI) { osmo_mgcpc_ep_fsm_event_names[i] = (struct value_string){i, "Unused"}; continue; } snprintf(osmo_mgcpc_ep_fsm_event_name_bufs[i], sizeof(osmo_mgcpc_ep_fsm_event_name_bufs[i]), "MGW Response for CI #%d", EV_TO_CI_IDX(i)); osmo_mgcpc_ep_fsm_event_names[i] = (struct value_string){i, osmo_mgcpc_ep_fsm_event_name_bufs[i]}; } } static __attribute__((constructor)) void osmo_mgcpc_ep_fsm_init(void) { OSMO_ASSERT(osmo_fsm_register(&osmo_mgcpc_ep_fsm) == 0); fill_event_names(); } struct osmo_mgcpc_ep *osmo_mgcpc_ep_fi_mgwep(struct osmo_fsm_inst *fi) { OSMO_ASSERT(fi); OSMO_ASSERT(fi->fsm == &osmo_mgcpc_ep_fsm); OSMO_ASSERT(fi->priv); return fi->priv; } /*! Allocate an osmo_mgcpc_ep FSM. * MGCP messages to set up the endpoint will be sent on the given mgcp_client, as soon as the first * osmo_mgcpc_ep_ci_request() is invoked. * * IMPORTANT: To avoid use-after-free problems, using this FSM requires use of deferred FSM deallocation using * osmo_fsm_set_dealloc_ctx(), e.g. using osmo_select_main_ctx(OTC_SELECT) with osmo_select_main_ctx() as main loop. * * A typical sequence of events would be: * * ep = osmo_mgcpc_ep_alloc(..., mgcp_client_rtpbridge_wildcard(client)); * ci_to_ran = osmo_mgcpc_ep_ci_add(ep); * osmo_mgcpc_ep_ci_request(ci_to_ran, MGCP_VERB_CRCX, verb_info, * my_call_fsm, MY_EVENT_MGCP_OK, MY_EVENT_MGCP_FAIL); * ci_to_cn = osmo_mgcpc_ep_ci_add(ep); * osmo_mgcpc_ep_ci_request(ci_to_cn, MGCP_VERB_CRCX, verb_info, * my_call_fsm, MY_EVENT_MGCP_OK, MY_EVENT_MGCP_FAIL); * ... * osmo_mgcpc_ep_ci_request(ci_to_ran, MGCP_VERB_MDCX, ...); * ... * osmo_mgcpc_ep_clear(ep); * ep = NULL; * * \param parent Parent FSM. * \param parent_term_event Event to dispatch to the parent on termination of this FSM instance. * \param mgcp_client Connection to the MGW. * \param T_defs Timeout definitions to be used for FSM states, see osmo_mgcpc_ep_fsm_timeouts. * \param fsm_id FSM instance ID. * \param endpoint_str_fmt The endpoint string format to send to the MGW upon the first CRCX. * See mgcp_client_rtpbridge_wildcard() for "rtpbridge" endpoints. */ struct osmo_mgcpc_ep *osmo_mgcpc_ep_alloc(struct osmo_fsm_inst *parent, uint32_t parent_term_event, struct mgcp_client *mgcp_client, const struct osmo_tdef *T_defs, const char *fsm_id, const char *endpoint_str_fmt, ...) { va_list ap; struct osmo_fsm_inst *fi; struct osmo_mgcpc_ep *ep; int rc; if (!mgcp_client) return NULL; fi = osmo_fsm_inst_alloc_child(&osmo_mgcpc_ep_fsm, parent, parent_term_event); OSMO_ASSERT(fi); osmo_fsm_inst_update_id(fi, fsm_id); ep = talloc_zero(fi, struct osmo_mgcpc_ep); OSMO_ASSERT(ep); *ep = (struct osmo_mgcpc_ep){ .mgcp_client = mgcp_client, .fi = fi, .T_defs = T_defs, }; INIT_LLIST_HEAD(&ep->background_notify); fi->priv = ep; va_start(ap, endpoint_str_fmt); rc = vsnprintf(ep->endpoint, sizeof(ep->endpoint), endpoint_str_fmt ? : "", ap); va_end(ap); if (rc <= 0 || rc >= sizeof(ep->endpoint)) { LOG_MGCPC_EP(ep, LOGL_ERROR, "Endpoint name too long or too short: %s\n", ep->endpoint); osmo_fsm_inst_term(ep->fi, OSMO_FSM_TERM_ERROR, 0); return NULL; } return ep; } /*! Add a connection to an endpoint. * Allocate a connection identifier slot in the osmo_mgcpc_ep instance, do not yet dispatch a CRCX. * The CRCX is dispatched only upon the first osmo_mgcpc_ep_ci_request(). * \param ep Parent endpoint instance. * \param label_fmt Label for logging. */ struct osmo_mgcpc_ep_ci *osmo_mgcpc_ep_ci_add(struct osmo_mgcpc_ep *ep, const char *label_fmt, ...) { va_list ap; int i; struct osmo_mgcpc_ep_ci *ci; for (i = 0; i < USABLE_CI; i++) { ci = &ep->ci[i]; if (ci->occupied || ci->mgcp_client_fi) continue; *ci = (struct osmo_mgcpc_ep_ci){ .ep = ep, .occupied = true, }; if (label_fmt) { va_start(ap, label_fmt); vsnprintf(ci->label, sizeof(ci->label), label_fmt, ap); va_end(ap); } return ci; } LOG_MGCPC_EP(ep, LOGL_ERROR, "Cannot allocate another endpoint, all " OSMO_STRINGIFY_VAL(USABLE_CI) " are in use\n"); return NULL; } static bool osmo_mgcpc_ep_fsm_check_state_chg_after_response(struct osmo_fsm_inst *fi); static void on_failure(struct osmo_mgcpc_ep_ci *ci) { struct osmo_mgcpc_ep *ep = ci->ep; struct fsm_notify notify; int i; if (!ci->occupied) return; /* When dispatching an event for this CI, the user may decide to trigger the next request for this conn right * away. So we must be ready with a cleared *ci. Store the notify separately and clear before dispatching. */ notify = ci->notify; /* Register the planned notification in ep->background_notify so we also catch any osmo_mgcpc_ep_cancel_notify() * that might be triggered between clearing the ci and actually dispatching the event. */ llist_add(¬ify.entry, &ep->background_notify); *ci = (struct osmo_mgcpc_ep_ci){ .ep = ci->ep, }; /* An MGCP failure typically means the endpoint becomes unusable, cancel all pending request (except DLCX). * Particularly, if two CRCX were scheduled and the first fails, we must no longer dispatch the second CRCX. */ for (i = 0; i < ARRAY_SIZE(ep->ci); i++) { struct osmo_mgcpc_ep_ci *other_ci = &ep->ci[i]; if (other_ci == ci) continue; if (!other_ci->occupied) continue; if (!other_ci->pending) continue; if (other_ci->sent) continue; if (other_ci->verb == MGCP_VERB_DLCX) continue; /* Just clear the pending request, don't fire more events than below. */ other_ci->pending = false; } /* If this check has terminated the FSM instance, don't fire any more events to prevent use-after-free problems. * The endpoint FSM does dispatch a term event to its parent, and everything should be cleaned like that. */ if (!osmo_mgcpc_ep_fsm_check_state_chg_after_response(ep->fi)) { /* The ep has deallocated, no need to llist_del(¬ify.entry) here. */ return; } if (notify.fi) osmo_fsm_inst_dispatch(notify.fi, notify.failure, notify.data); llist_del(¬ify.entry); } static int update_endpoint_name(struct osmo_mgcpc_ep_ci *ci, const char *new_endpoint_name) { struct osmo_mgcpc_ep *ep = ci->ep; int rc; int i; if (!strcmp(ep->endpoint, new_endpoint_name)) { /* Same endpoint name, nothing to do. */ return 0; } /* The endpoint name should only change on the very first CRCX response. */ if (ep->first_crcx_complete) { LOG_CI(ci, LOGL_ERROR, "Reponse returned mismatching endpoint name." " This is endpoint %s, instead received %s\n", ep->endpoint, new_endpoint_name); on_failure(ci); return -EINVAL; } /* This is the first CRCX response, update endpoint name. */ rc = OSMO_STRLCPY_ARRAY(ep->endpoint, new_endpoint_name); if (rc <= 0 || rc >= sizeof(ep->endpoint)) { LOG_CI(ci, LOGL_ERROR, "Unable to copy endpoint name %s\n", osmo_quote_str(new_endpoint_name, -1)); osmo_mgcpc_ep_ci_dlcx(ci); on_failure(ci); return -ENOSPC; } /* Make sure already pending requests use this updated endpoint name. */ for (i = 0; i < ARRAY_SIZE(ep->ci); i++) { struct osmo_mgcpc_ep_ci *other_ci = &ep->ci[i]; if (!other_ci->occupied) continue; if (!other_ci->pending) continue; if (other_ci->sent) continue; OSMO_STRLCPY_ARRAY(other_ci->verb_info.endpoint, ep->endpoint); } return 0; } static void on_success(struct osmo_mgcpc_ep_ci *ci, void *data) { struct mgcp_conn_peer *rtp_info; if (!ci->occupied) return; ci->pending = false; rtp_info = data; switch (ci->verb) { case MGCP_VERB_CRCX: /* If we sent a wildcarded endpoint name on CRCX, we need to store the resulting endpoint * name here. Also, we receive the MGW's RTP port information. */ osmo_strlcpy(ci->mgcp_ci_str, mgcp_conn_get_ci(ci->mgcp_client_fi), sizeof(ci->mgcp_ci_str)); if (rtp_info->endpoint[0]) { /* On errors, this instance might already be deallocated. Make sure to not access anything after * error. */ if (update_endpoint_name(ci, rtp_info->endpoint)) return; } ci->ep->first_crcx_complete = true; OSMO_ASSERT(rtp_info); /* fall through */ case MGCP_VERB_MDCX: /* Always update the received RTP ip/port information, since MGW * may provide new one after remote end params changed */ if (rtp_info) { ci->got_port_info = true; ci->rtp_info = *rtp_info; } break; default: break; } LOG_CI(ci, LOGL_DEBUG, "received successful response to %s: RTP=%s%s\n", osmo_mgcp_verb_name(ci->verb), mgcp_conn_peer_name(ci->got_port_info? &ci->rtp_info : NULL), ci->notify.fi ? "" : " (not sending a notification)"); /* Below ordering is a delicate decision: * * We want to * - emit the resulting event to ci->notify.fi, * - check whether we want to tx the next pending MGCP message. * Both these steps may terminate (=deallocate) the ep. * So whichever one goes first may cause a use-after-free in the other. * * When dispatching the FSM event, we don't get an rc indicating dealloc of the FSM -- it may deallocate and we * cannot tell. The common mechanism for that is osmo_fsm_set_dealloc_ctx(OTC_SELECT) and query the still * allocated FSM state after termination (here we would check 'if (ci->ep != NULL)'), but we cannot assume the * caller has actually set up an osmo_fsm_set_dealloc_ctx(). At time of writing, e.g. osmo-hnbgw does not use * it. * * In osmo_mgcpc_ep_fsm_check_state_chg_after_response(), we do get an rc: false means FSM has terminated. * On termination, the ep emits a term event to the FSM's parent. * That may cause the notify.fi to be terminated in turn, depending on how the caller set things up. * So: we cannot store notify.fi before, then call osmo_mgcpc_ep_fsm_check_state_chg_after_response(), and then * emit the event, because notify.fi may have deallocated. We cannot look up whether * osmo_mgcpc_ep_cancel_notify() has been called, because ci may have deallocated along with ci->ep. * * We have to skip emitting below success event in case the ep is now terminated. * - It may be the final DLCX OK: not a problem, osmo_mgcpc_ep_ci_dlcx() has no notify args on purpose, so we do * make all callers not set a notify event for DLCX by design. notify.fi should always be NULL when the final * DLCX OK terminates the local endpoint state. * - It may also be sudden termination due to a bad problem, in which case we shouldn't emit success. * The osmo_fsm_inst.parent_term_event should suffice as feedback to the caller. */ if (osmo_mgcpc_ep_fsm_check_state_chg_after_response(ci->ep->fi) == false) { /* false means, the ci->ep has been terminated. */ return; } if (ci->notify.fi) osmo_fsm_inst_dispatch(ci->notify.fi, ci->notify.success, ci->notify.data); } /*! Return the MGW's local RTP port information for this connection, i.e. the local port that MGW is receiving on, as * returned by the last CRCX-OK / MDCX-OK message. */ const struct mgcp_conn_peer *osmo_mgcpc_ep_ci_get_rtp_info(const struct osmo_mgcpc_ep_ci *ci) { ci = osmo_mgcpc_ep_check_ci((struct osmo_mgcpc_ep_ci*)ci); if (!ci) return NULL; if (!ci->got_port_info) return NULL; return &ci->rtp_info; } /*! Return the MGW's remote RTP port information for this connection, i.e. the remote RTP port that the MGW is sending * to, as sent to the MGW by the last CRCX / MDCX message. */ const struct mgcp_conn_peer *osmo_mgcpc_ep_ci_get_remote_rtp_info(const struct osmo_mgcpc_ep_ci *ci) { ci = osmo_mgcpc_ep_check_ci((struct osmo_mgcpc_ep_ci*)ci); if (!ci) return NULL; return &ci->verb_info; } /*! Return the MGW's RTP port information for this connection, as returned by the last CRCX/MDCX OK message. */ bool osmo_mgcpc_ep_ci_get_crcx_info_to_sockaddr(const struct osmo_mgcpc_ep_ci *ci, struct sockaddr_storage *dest) { const struct mgcp_conn_peer *rtp_info; int family; struct sockaddr_in *sin; struct sockaddr_in6 *sin6; rtp_info = osmo_mgcpc_ep_ci_get_rtp_info(ci); if (!rtp_info) return false; family = osmo_ip_str_type(rtp_info->addr); switch (family) { case AF_INET: sin = (struct sockaddr_in *)dest; sin->sin_family = AF_INET; sin->sin_port = osmo_ntohs(rtp_info->port); if (inet_pton(AF_INET, rtp_info->addr, &sin->sin_addr) != 1) return false; break; case AF_INET6: sin6 = (struct sockaddr_in6 *)dest; sin6->sin6_family = AF_INET6; sin6->sin6_port = osmo_ntohs(rtp_info->port); if (inet_pton(AF_INET6, rtp_info->addr, &sin6->sin6_addr) != 1) return false; break; default: return false; } return true; } bool osmo_mgcpc_ep_ci_get_crcx_info_to_osmux_cid(const struct osmo_mgcpc_ep_ci *ci, uint8_t* cid) { const struct mgcp_conn_peer *rtp_info; rtp_info = osmo_mgcpc_ep_ci_get_rtp_info(ci); if (!rtp_info) return false; if (!rtp_info->x_osmo_osmux_use) return false; *cid = rtp_info->x_osmo_osmux_cid; return true; } static const struct osmo_tdef_state_timeout osmo_mgcpc_ep_fsm_timeouts[32] = { [OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE] = { .T=-2427 }, }; /* Transition to a state, using the T timer defined in assignment_fsm_timeouts. * The actual timeout value is in turn obtained from osmo_mgcpc_ep.T_defs. * Assumes local variable fi exists. */ #define osmo_mgcpc_ep_fsm_state_chg(state) \ osmo_tdef_fsm_inst_state_chg(fi, state, osmo_mgcpc_ep_fsm_timeouts, \ ((struct osmo_mgcpc_ep*)fi->priv)->T_defs, 5) /*! Dispatch an actual CRCX/MDCX/DLCX message for this connection. * * If the 'notify' instance deallocates before it received a notification of event_success or event_failure, * osmo_mgcpc_ep_ci_cancel_notify() or osmo_mgcpc_ep_cancel_notify() must be called. It is not harmful to cancel * notification after an event has been received. * * \param ci Connection identifier as obtained from osmo_mgcpc_ep_ci_add(). * \param verb MGCP operation to dispatch. * \param verb_info Parameters for the MGCP operation. * \param notify Peer FSM instance to notify of completed/failed operation. * \param event_success Which event to dispatch to 'notify' upon OK response. * \param event_failure Which event to dispatch to 'notify' upon failure response. * \param notify_data Data pointer to pass to the event dispatch for both success and failure. */ void osmo_mgcpc_ep_ci_request(struct osmo_mgcpc_ep_ci *ci, enum mgcp_verb verb, const struct mgcp_conn_peer *verb_info, struct osmo_fsm_inst *notify, uint32_t event_success, uint32_t event_failure, void *notify_data) { struct osmo_mgcpc_ep *ep; struct osmo_fsm_inst *fi; struct osmo_mgcpc_ep_ci cleared_ci; ci = osmo_mgcpc_ep_check_ci(ci); if (!ci) { LOGP(DLMGCP, LOGL_ERROR, "Invalid MGW endpoint request: no ci\n"); goto dispatch_error; } if (!verb_info && verb != MGCP_VERB_DLCX) { LOG_CI(ci, LOGL_ERROR, "Invalid MGW endpoint request: missing verb details for %s\n", osmo_mgcp_verb_name(verb)); goto dispatch_error; } if ((verb < 0) || (verb > MGCP_VERB_RSIP)) { LOG_CI(ci, LOGL_ERROR, "Invalid MGW endpoint request: unknown verb: %s\n", osmo_mgcp_verb_name(verb)); goto dispatch_error; } ep = ci->ep; fi = ep->fi; /* Clear volatile state by explicitly keeping those that should remain. Because we can't assign * the char[] directly, dance through cleared_ci and copy back. */ cleared_ci = (struct osmo_mgcpc_ep_ci){ .ep = ep, .mgcp_client_fi = ci->mgcp_client_fi, .got_port_info = ci->got_port_info, .rtp_info = ci->rtp_info, .occupied = true, /* .pending = true follows below */ .verb = verb, .notify = { .fi = notify, .success = event_success, .failure = event_failure, .data = notify_data, } }; osmo_strlcpy(cleared_ci.label, ci->label, sizeof(cleared_ci.label)); osmo_strlcpy(cleared_ci.mgcp_ci_str, ci->mgcp_ci_str, sizeof(cleared_ci.mgcp_ci_str)); *ci = cleared_ci; if (verb_info) ci->verb_info = *verb_info; LOG_CI_VERB(ci, LOGL_DEBUG, "notify=%s\n", osmo_fsm_inst_name(ci->notify.fi)); if (ep->endpoint[0]) { if (ci->verb_info.endpoint[0] && strcmp(ci->verb_info.endpoint, ep->endpoint)) LOG_CI(ci, LOGL_ERROR, "Warning: Requested %s on endpoint %s, but this CI is on endpoint %s." " Using the proper endpoint instead.\n", osmo_mgcp_verb_name(verb), ci->verb_info.endpoint, ep->endpoint); osmo_strlcpy(ci->verb_info.endpoint, ep->endpoint, sizeof(ci->verb_info.endpoint)); } switch (ci->verb) { case MGCP_VERB_CRCX: if (ci->mgcp_client_fi) { LOG_CI(ci, LOGL_ERROR, "CRCX can be called only once per MGW endpoint CI\n"); on_failure(ci); return; } break; case MGCP_VERB_MDCX: if (!ci->mgcp_client_fi) { LOG_CI_VERB(ci, LOGL_ERROR, "The first verb on an unused MGW endpoint CI must be CRCX, not %s\n", osmo_mgcp_verb_name(ci->verb)); on_failure(ci); return; } break; case MGCP_VERB_DLCX: if (!ci->mgcp_client_fi) { LOG_CI_VERB(ci, LOGL_DEBUG, "Ignoring DLCX on unused MGW endpoint CI\n"); return; } break; default: LOG_CI(ci, LOGL_ERROR, "This verb is not supported: %s\n", osmo_mgcp_verb_name(ci->verb)); on_failure(ci); return; } ci->pending = true; LOG_CI_VERB(ci, LOGL_DEBUG, "Scheduling\n"); if (ep->fi->state != OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE) osmo_mgcpc_ep_fsm_state_chg(OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE); return; dispatch_error: if (notify) osmo_fsm_inst_dispatch(notify, event_failure, notify_data); } /*! No longer notify for any state changes for any conns of this endpoint. * Useful if the notify instance passed to osmo_mgcpc_ep_ci_request() is about to deallocate. * \param ep The endpoint FSM instance. * \param notify Which target to cancel notification for, if NULL cancel all notifications. */ void osmo_mgcpc_ep_cancel_notify(struct osmo_mgcpc_ep *ep, struct osmo_fsm_inst *notify) { struct fsm_notify *n; int i; for (i = 0; i < ARRAY_SIZE(ep->ci); i++) { struct osmo_mgcpc_ep_ci *ci = &ep->ci[i]; if (!notify || ci->notify.fi == notify) ci->notify.fi = NULL; } llist_for_each_entry(n, &ep->background_notify, entry) { if (!notify || n->fi == notify) n->fi = NULL; } } /* Return the osmo_mgcpc_ep that this conn belongs to. */ struct osmo_mgcpc_ep *osmo_mgcpc_ep_ci_ep(struct osmo_mgcpc_ep_ci *conn) { if (!conn) return NULL; return conn->ep; } static int send_verb(struct osmo_mgcpc_ep_ci *ci) { int rc; struct osmo_mgcpc_ep *ep = ci->ep; struct fsm_notify notify; if (!ci->occupied || !ci->pending || ci->sent) return 0; switch (ci->verb) { case MGCP_VERB_CRCX: OSMO_ASSERT(!ci->mgcp_client_fi); LOG_CI_VERB(ci, LOGL_DEBUG, "Sending\n"); ci->mgcp_client_fi = mgcp_conn_create(ep->mgcp_client, ep->fi, CI_EV_FAILURE(ci), CI_EV_SUCCESS(ci), &ci->verb_info); ci->sent = true; if (!ci->mgcp_client_fi){ LOG_CI_VERB(ci, LOGL_ERROR, "Cannot send\n"); on_failure(ci); return -EINVAL; } osmo_fsm_inst_update_id(ci->mgcp_client_fi, ci->label); break; case MGCP_VERB_MDCX: OSMO_ASSERT(ci->mgcp_client_fi); LOG_CI_VERB(ci, LOGL_DEBUG, "Sending\n"); rc = mgcp_conn_modify(ci->mgcp_client_fi, CI_EV_SUCCESS(ci), &ci->verb_info); ci->sent = true; if (rc) { LOG_CI_VERB(ci, LOGL_ERROR, "Cannot send (rc=%d %s)\n", rc, strerror(-rc)); on_failure(ci); return -EINVAL; } break; case MGCP_VERB_DLCX: LOG_CI(ci, LOGL_DEBUG, "Sending MGCP: %s %s\n", osmo_mgcp_verb_name(ci->verb), ci->mgcp_ci_str); /* The way this is designed, we actually need to forget all about the ci right away. */ mgcp_conn_delete(ci->mgcp_client_fi); notify = ci->notify; *ci = (struct osmo_mgcpc_ep_ci){ .ep = ep, }; /* When dispatching an event for this CI, the user may decide to trigger the next request for this conn * right away. So we must be ready with a cleared *ci. */ if (notify.fi) osmo_fsm_inst_dispatch(notify.fi, notify.success, notify.data); break; default: OSMO_ASSERT(false); } return 1; } /*! DLCX all connections, terminate the endpoint FSM and free. */ void osmo_mgcpc_ep_clear(struct osmo_mgcpc_ep *ep) { if (!ep) return; osmo_mgcpc_ep_cancel_notify(ep, NULL); osmo_fsm_inst_term(ep->fi, OSMO_FSM_TERM_REGULAR, 0); } static void osmo_mgcpc_ep_count(struct osmo_mgcpc_ep *ep, int *occupied, int *pending_not_sent, int *waiting_for_response) { int i; if (occupied) *occupied = 0; if (pending_not_sent) *pending_not_sent = 0; if (waiting_for_response) *waiting_for_response = 0; for (i = 0; i < ARRAY_SIZE(ep->ci); i++) { struct osmo_mgcpc_ep_ci *ci = &ep->ci[i]; if (ci->occupied) { if (occupied) (*occupied)++; } else continue; if (ci->pending) LOG_CI_VERB(ci, LOGL_DEBUG, "%s\n", ci->sent ? "waiting for response" : "waiting to be sent"); else LOG_CI_VERB(ci, LOGL_DEBUG, "done (%s)\n", mgcp_conn_peer_name(osmo_mgcpc_ep_ci_get_rtp_info(ci))); if (ci->pending && ci->sent) if (waiting_for_response) (*waiting_for_response)++; if (ci->pending && !ci->sent) if (pending_not_sent) (*pending_not_sent)++; } } static bool osmo_mgcpc_ep_fsm_check_state_chg_after_response(struct osmo_fsm_inst *fi) { int waiting_for_response; int occupied; struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi); osmo_mgcpc_ep_count(ep, &occupied, NULL, &waiting_for_response); LOG_MGCPC_EP(ep, LOGL_DEBUG, "CI in use: %d, waiting for response: %d\n", occupied, waiting_for_response); if (!occupied) { /* All CI have been released. The endpoint no longer exists. Notify the parent FSM, by * terminating. */ osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, 0); return false; } if (!waiting_for_response) { if (fi->state != OSMO_MGCPC_EP_ST_IN_USE) osmo_mgcpc_ep_fsm_state_chg(OSMO_MGCPC_EP_ST_IN_USE); } return true; } static void osmo_mgcpc_ep_fsm_wait_mgw_response_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) { static int re_enter = 0; int rc; int count = 0; int i; struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi); re_enter++; OSMO_ASSERT(re_enter < 10); /* The first CRCX gives us the endpoint name in the CRCX response. So we must wait for the first CRCX endpoint * response to come in before sending any other MGCP requests -- otherwise we might end up creating new * endpoints instead of acting on the same. This FSM always sends out N requests and waits for all of them to * complete before sending out new requests. Hence we're safe when the very first time at most one request is * sent (which needs to be a CRCX). */ for (i = 0; i < ARRAY_SIZE(ep->ci); i++) { struct osmo_mgcpc_ep_ci *ci = &ep->ci[i]; /* Make sure that only CRCX get dispatched if no CRCX were sent yet. */ if (!ep->first_crcx_complete) { if (ci->occupied && ci->verb != MGCP_VERB_CRCX) continue; } rc = send_verb(&ep->ci[i]); /* Need to be careful not to access the instance after failure. Event chains may already have * deallocated this memory. */ if (rc < 0) return; if (!rc) continue; count++; /* Make sure that we wait for the first CRCX response before dispatching more requests. */ if (!ep->first_crcx_complete) break; } LOG_MGCPC_EP(ep, LOGL_DEBUG, "Sent messages: %d\n", count); if (ep->first_crcx_complete) osmo_mgcpc_ep_fsm_check_state_chg_after_response(fi); re_enter--; } static void osmo_mgcpc_ep_fsm_handle_ci_events(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct osmo_mgcpc_ep_ci *ci; struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi); ci = osmo_mgcpc_ep_ci_for_event(ep, event); if (ci) { if (event == CI_EV_SUCCESS(ci)) on_success(ci, data); else on_failure(ci); } } static void osmo_mgcpc_ep_fsm_in_use_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) { int pending_not_sent; struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi); osmo_mgcpc_ep_count(ep, NULL, &pending_not_sent, NULL); if (pending_not_sent) osmo_mgcpc_ep_fsm_state_chg(OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE); } #define S(x) (1 << (x)) static const struct osmo_fsm_state osmo_mgcpc_ep_fsm_states[] = { [OSMO_MGCPC_EP_ST_UNUSED] = { .name = "UNUSED", .in_event_mask = 0, .out_state_mask = 0 | S(OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE) , }, [OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE] = { .name = "WAIT_MGW_RESPONSE", .onenter = osmo_mgcpc_ep_fsm_wait_mgw_response_onenter, .action = osmo_mgcpc_ep_fsm_handle_ci_events, .in_event_mask = 0xffffffff, .out_state_mask = 0 | S(OSMO_MGCPC_EP_ST_IN_USE) , }, [OSMO_MGCPC_EP_ST_IN_USE] = { .name = "IN_USE", .onenter = osmo_mgcpc_ep_fsm_in_use_onenter, .action = osmo_mgcpc_ep_fsm_handle_ci_events, .in_event_mask = 0xffffffff, /* mgcp_client_fsm may send parent term anytime */ .out_state_mask = 0 | S(OSMO_MGCPC_EP_ST_WAIT_MGW_RESPONSE) , }, }; static int osmo_mgcpc_ep_fsm_timer_cb(struct osmo_fsm_inst *fi) { int i; struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi); switch (fi->T) { default: for (i = 0; i < ARRAY_SIZE(ep->ci); i++) { struct osmo_mgcpc_ep_ci *ci = &ep->ci[i]; if (!ci->occupied) continue; if (!(ci->pending && ci->sent)) continue; on_failure(ci); } return 0; } return 0; } static void osmo_mgcpc_ep_fsm_pre_term(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause) { int i; struct osmo_mgcpc_ep *ep = osmo_mgcpc_ep_fi_mgwep(fi); /* We want the mgcp_client_fsm to still stick around until it received the DLCX "OK" responses from the MGW. So * it should not dealloc along with this ep_fsm instance. Instead, signal DLCX for each conn on the endpoint, * and detach the mgcp_client_fsm from being a child-fsm. * * After mgcp_conn_delete(), an mgcp_client_fsm instance goes into ST_DLCX_RESP, which waits up to 4 seconds for * a DLCX OK. If none is received in that time, the instance terminates. So cleanup of the instance is * guaranteed. */ for (i = 0; i < ARRAY_SIZE(ep->ci); i++) { struct osmo_mgcpc_ep_ci *ci = &ep->ci[i]; if (!ci->occupied || !ci->mgcp_client_fi) continue; /* mgcp_conn_delete() unlinks itself from this parent FSM implicitly and waits for the DLCX OK. */ mgcp_conn_delete(ci->mgcp_client_fi); /* Forget all about this ci */ *ci = (struct osmo_mgcpc_ep_ci){ .ep = ep, }; } } static struct osmo_fsm osmo_mgcpc_ep_fsm = { .name = "mgw-endp", .states = osmo_mgcpc_ep_fsm_states, .num_states = ARRAY_SIZE(osmo_mgcpc_ep_fsm_states), .log_subsys = DLMGCP, .event_names = osmo_mgcpc_ep_fsm_event_names, .timer_cb = osmo_mgcpc_ep_fsm_timer_cb, .pre_term = osmo_mgcpc_ep_fsm_pre_term, };