/* (C) 2017 by Harald Welte * All Rights Reserved * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define S(x) (1 << (x)) #define MGCP_MGW_TIMEOUT 4 /* in seconds */ #define MGCP_MGW_TIMEOUT_TIMER_NR 1 #define MGCP_MGW_HO_TIMEOUT 4 /* in seconds */ #define MGCP_MGW_HO_TIMEOUT_TIMER_NR 2 enum gscon_fsm_states { ST_INIT, /* wait for initial BSSMAP after the MSC opened a new SCCP connection */ ST_WAIT_INITIAL_USER_DATA, /* waiting for CC from MSC */ ST_WAIT_CC, /* active connection */ ST_ACTIVE, ST_ASSIGNMENT, ST_HANDOVER, /* BSSMAP CLEAR has been received */ ST_WAIT_CLEAR_CMD, ST_WAIT_SCCP_RLSD, }; static const struct value_string gscon_fsm_event_names[] = { {GSCON_EV_A_CONN_IND, "MT-CONNECT.ind"}, {GSCON_EV_A_INITIAL_USER_DATA, "A_INITIAL_USER_DATA"}, {GSCON_EV_MO_COMPL_L3, "MO_COMPL_L3"}, {GSCON_EV_A_CONN_CFM, "MO-CONNECT.cfm"}, {GSCON_EV_A_CLEAR_CMD, "CLEAR_CMD"}, {GSCON_EV_A_DISC_IND, "DISCONNECT.ind"}, {GSCON_EV_A_COMMON_ID_IND, "COMMON_ID.ind"}, {GSCON_EV_ASSIGNMENT_START, "ASSIGNMENT_START"}, {GSCON_EV_ASSIGNMENT_END, "ASSIGNMENT_END"}, {GSCON_EV_HANDOVER_START, "HANDOVER_START"}, {GSCON_EV_HANDOVER_END, "HANDOVER_END"}, {GSCON_EV_RSL_CONN_FAIL, "RSL_CONN_FAIL"}, {GSCON_EV_MO_DTAP, "MO_DTAP"}, {GSCON_EV_MT_DTAP, "MT_DTAP"}, {GSCON_EV_TX_SCCP, "TX_SCCP"}, {GSCON_EV_MGW_MDCX_RESP_MSC, "MGW_MDCX_RESP_MSC"}, {GSCON_EV_LCLS_FAIL, "LCLS_FAIL"}, {GSCON_EV_FORGET_LCHAN, "FORGET_LCHAN"}, {GSCON_EV_FORGET_MGW_ENDPOINT, "FORGET_MGW_ENDPOINT"}, {GSCON_EV_LCS_LOC_REQ_END, "LCS_LOC_REQ_END"}, {} }; struct osmo_tdef_state_timeout conn_fsm_timeouts[32] = { [ST_WAIT_INITIAL_USER_DATA] = { .T = -25 }, [ST_WAIT_CC] = { .T = -3210 }, [ST_WAIT_CLEAR_CMD] = { .T = -4 }, [ST_WAIT_SCCP_RLSD] = { .T = -4 }, }; /* Transition to a state, using the T timer defined in conn_fsm_timeouts. * The actual timeout value is in turn obtained from network->T_defs. * Assumes local variable 'conn' exists. */ #define conn_fsm_state_chg(state) \ osmo_tdef_fsm_inst_state_chg(conn->fi, state, \ conn_fsm_timeouts, \ conn->network->T_defs, \ -1) /* forward MT DTAP from BSSAP side to RSL side */ static inline void submit_dtap(struct gsm_subscriber_connection *conn, struct msgb *msg) { OSMO_ASSERT(msg); OSMO_ASSERT(conn); gscon_submit_rsl_dtap(conn, msg, OBSC_LINKID_CB(msg), 1); } static void gscon_dtap_queue_flush(struct gsm_subscriber_connection *conn, int send); int gscon_sigtran_send(struct gsm_subscriber_connection *conn, struct msgb *msg) { int rc; if (!msg) return -ENOMEM; /* Make sure that we only attempt to send SCCP messages if we have * a live SCCP connection. Otherwise drop the message. */ if (conn->fi->state == ST_INIT || conn->fi->state == ST_WAIT_CC) { LOGPFSML(conn->fi, LOGL_ERROR, "No active SCCP connection, dropping message\n"); msgb_free(msg); return -ENODEV; } rc = osmo_bsc_sigtran_send(conn, msg); if (rc < 0) LOGPFSML(conn->fi, LOGL_ERROR, "Unable to deliver SCCP message\n"); return rc; } void gscon_bssmap_clear(struct gsm_subscriber_connection *conn, enum gsm0808_cause cause) { /* already clearing? */ switch (conn->fi->state) { case ST_WAIT_CLEAR_CMD: case ST_WAIT_SCCP_RLSD: return; default: break; } conn->clear_cause = cause; conn_fsm_state_chg(ST_WAIT_CLEAR_CMD); } static void gscon_fsm_wait_clear_cmd_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) { struct msgb *resp; int rc; struct gsm_subscriber_connection *conn = fi->priv; enum gsm0808_cause cause = conn->clear_cause; if (!conn->sccp.msc) { LOGPFSML(fi, LOGL_ERROR, "Unable to deliver BSSMAP Clear Request message, no MSC for this conn\n"); goto nothing_sent; } LOGPFSML(fi, LOGL_DEBUG, "Tx BSSMAP CLEAR REQUEST(%s) to MSC\n", gsm0808_cause_name(cause)); resp = gsm0808_create_clear_rqst(cause); if (!resp) { LOGPFSML(fi, LOGL_ERROR, "Unable to compose BSSMAP Clear Request message\n"); goto nothing_sent; } rate_ctr_inc(rate_ctr_group_get_ctr(conn->sccp.msc->msc_ctrs, MSC_CTR_BSSMAP_TX_DT1_CLEAR_RQST)); rc = osmo_bsc_sigtran_send(conn, resp); if (rc < 0) { LOGPFSML(conn->fi, LOGL_ERROR, "Unable to deliver BSSMAP Clear Request message\n"); goto nothing_sent; } return; nothing_sent: /* Normally, we request a CLEAR from the MSC and terminate as soon as the CLEAR COMMAND has been issued by the * MSC. But if we are trying to clear without being able to send anything to the MSC, we might as well shut down * the conn right away now. */ conn_fsm_state_chg(ST_WAIT_SCCP_RLSD); } void gscon_fsm_wait_sccp_rlsd_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) { struct gsm_subscriber_connection *conn = fi->priv; /* According to 3GPP 48.008 3.1.9.1. "The BSS need not wait for the radio channel * release to be completed or for the guard timer to expire before returning the * CLEAR COMPLETE message" */ if (!gscon_sigtran_send(conn, gsm0808_create_clear_complete())) rate_ctr_inc(rate_ctr_group_get_ctr(conn->sccp.msc->msc_ctrs, MSC_CTR_BSSMAP_TX_DT1_CLEAR_COMPLETE)); /* Give the handover_fsm a chance to book this as handover success before tearing down everything, * making it look like a sudden death failure. */ if (conn->ho.fi) osmo_fsm_inst_dispatch(conn->ho.fi, HO_EV_CONN_RELEASING, NULL); if (conn->lcs.loc_req) osmo_fsm_inst_dispatch(conn->lcs.loc_req->fi, LCS_LOC_REQ_EV_CONN_CLEAR, NULL); if (conn->vgcs_call.fi) osmo_fsm_inst_dispatch(conn->vgcs_call.fi, VGCS_EV_CLEANUP, NULL); if (conn->vgcs_chan.fi) osmo_fsm_inst_dispatch(conn->vgcs_chan.fi, VGCS_EV_CLEANUP, NULL); gscon_release_lchans(conn, true, bsc_gsm48_rr_cause_from_gsm0808_cause(conn->clear_cause)); osmo_mgcpc_ep_clear(conn->user_plane.mgw_endpoint); /* If there is no SCCP connection at all, then no need to wait for an SCCP RLSD. */ if (!conn->sccp.msc || conn->sccp.state != SUBSCR_SCCP_ST_CONNECTED) osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); } /* forward MO DTAP from RSL side to BSSAP side */ static void forward_dtap(struct gsm_subscriber_connection *conn, struct msgb *msg, struct osmo_fsm_inst *fi) { struct msgb *resp = NULL; OSMO_ASSERT(msg); OSMO_ASSERT(conn); resp = gsm0808_create_dtap(msg, OBSC_LINKID_CB(msg)); rate_ctr_inc(rate_ctr_group_get_ctr(conn->sccp.msc->msc_ctrs, MSC_CTR_BSSMAP_TX_DT1_DTAP)); gscon_sigtran_send(conn, resp); } /* Release an lchan in such a way that it doesn't fire events back to the conn. */ static void gscon_release_lchan(struct gsm_subscriber_connection *conn, struct gsm_lchan *lchan, bool do_rr_release, bool err, enum gsm48_rr_cause cause_rr) { if (!lchan || !conn) return; if (lchan->conn == conn) lchan_forget_conn(lchan); if (conn->lchan == lchan) conn->lchan = NULL; if (conn->ho.fi && conn->ho.new_lchan == lchan) conn->ho.new_lchan = NULL; if (conn->vgcs_chan.new_lchan == lchan) conn->vgcs_chan.new_lchan = NULL; if (conn->assignment.new_lchan == lchan) conn->assignment.new_lchan = NULL; lchan_release(lchan, do_rr_release, err, cause_rr, gscon_last_eutran_plmn(conn)); } void gscon_release_lchans(struct gsm_subscriber_connection *conn, bool do_rr_release, enum gsm48_rr_cause cause_rr) { if (conn->ho.fi) handover_end(conn, HO_RESULT_CONN_RELEASE); assignment_reset(conn); gscon_release_lchan(conn, conn->lchan, do_rr_release, false, cause_rr); } static int validate_initial_user_data(struct osmo_fsm_inst *fi, struct msgb *msg) { struct bssmap_header *bs; enum BSS_MAP_MSG_TYPE bssmap_type; msg->l3h = msgb_l2(msg); if (!msgb_l3(msg)) { LOGPFSML(fi, LOGL_ERROR, "internal error: no l3 in msg\n"); return -EINVAL; } if (msgb_l3len(msg) < sizeof(*bs)) { LOGPFSML(fi, LOGL_ERROR, "message too short for BSSMAP header (%u < %zu)\n", msgb_l3len(msg), sizeof(*bs)); return -EINVAL; } bs = (struct bssmap_header*)msgb_l3(msg); if (msgb_l3len(msg) < (bs->length + sizeof(*bs))) { LOGPFSML(fi, LOGL_ERROR, "message too short for length indicated in BSSMAP header (%u < %u)\n", msgb_l3len(msg), bs->length); return -EINVAL; } switch (bs->type) { case BSSAP_MSG_BSS_MANAGEMENT: break; default: LOGPFSML(fi, LOGL_ERROR, "message type not allowed for initial BSSMAP: %s\n", gsm0808_bssap_name(bs->type)); return -EINVAL; } msg->l4h = &msg->l3h[sizeof(*bs)]; /* Validate initial message type. See also BSC_Tests.TC_outbound_connect. */ bssmap_type = msg->l4h[0]; switch (bssmap_type) { case BSS_MAP_MSG_HANDOVER_RQST: case BSS_MAP_MSG_PERFORM_LOCATION_RQST: case BSS_MAP_MSG_VGCS_VBS_SETUP: case BSS_MAP_MSG_VGCS_VBS_ASSIGNMENT_RQST: return 0; default: LOGPFSML(fi, LOGL_ERROR, "No support for initial BSSMAP: %s: %s\n", gsm0808_bssap_name(bs->type), gsm0808_bssmap_name(bssmap_type)); return -EINVAL; } } static void handle_initial_user_data(struct osmo_fsm_inst *fi, struct msgb *msg) { struct gsm_subscriber_connection *conn = fi->priv; struct bssmap_header *bs; enum BSS_MAP_MSG_TYPE bssmap_type; /* validate_initial_user_data() must be called before this */ OSMO_ASSERT(msgb_l4(msg)); bs = msgb_l3(msg); bssmap_type = msg->l4h[0]; /* FIXME: Extract optional IMSI and update FSM using osmo_fsm_inst_set_id() (OS#2969) */ LOGPFSML(fi, LOGL_DEBUG, "Rx initial BSSMAP: %s: %s\n", gsm0808_bssap_name(bs->type), gsm0808_bssmap_name(bssmap_type)); switch (bssmap_type) { case BSS_MAP_MSG_HANDOVER_RQST: rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_RX_DT1_HANDOVER_RQST]); /* Inter-BSC incoming Handover Request, another BSS is handovering to us. */ handover_start_inter_bsc_in(conn, msg); return; case BSS_MAP_MSG_PERFORM_LOCATION_RQST: rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_RX_DT1_PERFORM_LOCATION_REQUEST]); /* Location Services: MSC asks for location of an IDLE subscriber */ conn_fsm_state_chg(ST_ACTIVE); lcs_loc_req_start(conn, msg); return; case BSS_MAP_MSG_VGCS_VBS_SETUP: rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_RX_DT1_VGCS_VBS_SETUP]); /* VGCS: MSC asks vor voice group/bcast call. */ conn_fsm_state_chg(ST_ACTIVE); vgcs_vbs_call_start(conn, msg); return; case BSS_MAP_MSG_VGCS_VBS_ASSIGNMENT_RQST: rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_RX_DT1_VGCS_VBS_ASSIGN_RQST]); /* VGCS: MSC asks vor resource (channel) for voice group/bcast call. */ conn_fsm_state_chg(ST_ACTIVE); vgcs_vbs_chan_start(conn, msg); return; default: LOGPFSML(fi, LOGL_ERROR, "No support for initial BSSMAP: %s: %s\n", gsm0808_bssap_name(bs->type), gsm0808_bssmap_name(bssmap_type)); osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); return; } } static void handle_sccp_n_connect(struct osmo_fsm_inst *fi, struct osmo_scu_prim *scu_prim) { struct gsm_subscriber_connection *conn = fi->priv; struct msgb *msg = scu_prim->oph.msg; /* Make sure the conn FSM will osmo_sccp_tx_disconn() on term */ conn->sccp.state = SUBSCR_SCCP_ST_CONNECTED; msg->l3h = msgb_l2(msg); /* If (BSSMAP) user data is included, validate it before accepting the connection */ if (msgb_l3(msg) && msgb_l3len(msg)) { if (validate_initial_user_data(fi, msg)) { osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); return; } } /* accept the new conn. */ if (osmo_sccp_tx_conn_resp(conn->sccp.msc->a.sccp_user, scu_prim->u.connect.conn_id, &scu_prim->u.connect.called_addr, NULL, 0)) { LOGPFSML(fi, LOGL_ERROR, "Cannot send SCCP CONN RESP\n"); osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); return; } /* The initial user data may already be included in this N-Connect, or it may come later in a separate message. * If it is already included, also go to ST_WAIT_INITIAL_USER_DATA now, so that we don't have to tend to two * separate code paths doing the same thing (handling of HANDOVER_END). */ OSMO_ASSERT(conn_fsm_state_chg(ST_WAIT_INITIAL_USER_DATA) == 0); /* It is usually a bad idea to continue using a fi after a state change, because the fi might terminate during * the state change. In this case it is certain that the fi stays around for the initial user data. */ if (msgb_l3(msg) && msgb_l3len(msg)) { handle_initial_user_data(fi, msg); } else { LOGPFSML(fi, LOGL_DEBUG, "N-Connect does not contain user data (no BSSMAP message included)\n"); } } static void gscon_fsm_init(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_subscriber_connection *conn = fi->priv; struct osmo_scu_prim *scu_prim = NULL; struct msgb *msg = NULL; int rc; switch (event) { case GSCON_EV_MO_COMPL_L3: /* RLL ESTABLISH IND with initial L3 Message */ msg = data; rc = osmo_bsc_sigtran_open_conn(conn, msg); if (rc < 0) { osmo_fsm_inst_term(fi, OSMO_FSM_TERM_ERROR, NULL); } else { /* SCCP T(conn est) is 1-2 minutes, way too long. The MS will timeout * using T3210 (20s), T3220 (5s) or T3230 (10s) */ conn_fsm_state_chg(ST_WAIT_CC); } gscon_update_id(conn); break; case GSCON_EV_A_CONN_IND: gscon_update_id(conn); scu_prim = data; if (!conn->sccp.msc) { LOGPFSML(fi, LOGL_NOTICE, "N-CONNECT.ind from unknown MSC %s\n", osmo_sccp_addr_dump(&scu_prim->u.connect.calling_addr)); /* We cannot find a way to the sccp_user without the MSC, so we cannot * use osmo_sccp_tx_disconn() :( */ //osmo_sccp_tx_disconn(conn->sccp.msc->a.sccp_user, scu_prim->u.connect.conn_id, &scu_prim->u.connect.called_addr, 0); osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); return; } handle_sccp_n_connect(fi, scu_prim); break; default: OSMO_ASSERT(false); } } static void gscon_fsm_wait_initial_user_data(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_subscriber_connection *conn = fi->priv; struct msgb *msg = data; enum handover_result ho_result; switch (event) { case GSCON_EV_A_INITIAL_USER_DATA: if (validate_initial_user_data(fi, msg)) { osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); return; } handle_initial_user_data(fi, msg); break; case GSCON_EV_HANDOVER_END: ho_result = HO_RESULT_ERROR; if (data) ho_result = *(enum handover_result*)data; LOGPFSML(fi, LOGL_DEBUG, "Handover result: %s\n", handover_result_name(ho_result)); if (ho_result == HO_RESULT_OK) { /* In this case the ho struct should still be populated. */ if (conn->ho.scope & HO_INTER_BSC_IN) { /* Done with establishing a conn where we accept another BSC's MS via * inter-BSC handover */ osmo_fsm_inst_state_chg(fi, ST_ACTIVE, 0, 0); gscon_dtap_queue_flush(conn, 1); return; } LOG_HO(conn, LOGL_ERROR, "Conn is in state %s, the only accepted handover kind is inter-BSC incoming handover\n", osmo_fsm_inst_state_name(conn->fi)); } gscon_bssmap_clear(conn, GSM0808_CAUSE_EQUIPMENT_FAILURE); return; default: OSMO_ASSERT(false); } } /* We've sent the CONNECTION.req to the SCCP provider and are waiting for CC from MSC */ static void gscon_fsm_wait_cc(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_subscriber_connection *conn = fi->priv; switch (event) { case GSCON_EV_A_CONN_CFM: /* MSC has confirmed the connection */ if (!conn->lchan) { /* If associated lchan was released while we were waiting for the confirmed connection, then instead simply drop the connection */ LOGPFSML(fi, LOGL_INFO, "Connection confirmed but lchan was dropped previously, clearing conn\n"); gscon_bssmap_clear(conn, GSM0808_CAUSE_EQUIPMENT_FAILURE); break; } /* We now change into the active state and wait there for further operations. */ conn_fsm_state_chg(ST_ACTIVE); /* if there's user payload, forward it just like EV_MT_DTAP */ /* FIXME: Question: if there's user payload attached to the CC, forward it like EV_MT_DTAP? */ break; default: OSMO_ASSERT(false); } } /* We're on an active subscriber connection, passing DTAP back and forth */ static void gscon_fsm_active(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_subscriber_connection *conn = fi->priv; struct gsm_bts *bts; switch (event) { case GSCON_EV_ASSIGNMENT_START: bts = conn->lchan? conn->lchan->ts->trx->bts : NULL; if (!bts) { LOGPFSML(fi, LOGL_ERROR, "Cannot do assignment, no active BTS\n"); return; } /* Rely on assignment_fsm timeout */ osmo_fsm_inst_state_chg(fi, ST_ASSIGNMENT, 0, 0); assignment_fsm_start(conn, bts, data); return; case GSCON_EV_HANDOVER_START: /* Rely on handover_fsm timeout */ if (osmo_fsm_inst_state_chg(fi, ST_HANDOVER, 0, 0)) LOGPFSML(fi, LOGL_ERROR, "Cannot transition to HANDOVER state, discarding\n"); else handover_start(data); break; case GSCON_EV_MO_DTAP: forward_dtap(conn, (struct msgb *)data, fi); break; case GSCON_EV_MT_DTAP: submit_dtap(conn, (struct msgb *)data); break; case GSCON_EV_TX_SCCP: gscon_sigtran_send(conn, (struct msgb *)data); break; case GSCON_EV_LCS_LOC_REQ_END: /* On the A-interface, there is nothing to do. If there still is an lchan, the conn should stay open. If * not, it is up to the MSC to send a Clear Command. * On the Lb-interface, tear down the SCCP connection. */ lb_close_conn(conn); break; case GSCON_EV_MO_COMPL_L3: /* It is possible to have an A-interface conn already established without an lchan being active, during * a Perform Location Request (LCS). */ /* RLL ESTABLISH IND with initial L3 Message */ gscon_sigtran_send(conn, (struct msgb*)data); break; default: OSMO_ASSERT(false); } } static void gscon_fsm_assignment(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_subscriber_connection *conn = fi->priv; switch (event) { case GSCON_EV_ASSIGNMENT_END: osmo_fsm_inst_state_chg(fi, ST_ACTIVE, 0, 0); gscon_dtap_queue_flush(conn, 1); return; case GSCON_EV_MO_DTAP: forward_dtap(conn, (struct msgb *)data, fi); break; case GSCON_EV_MT_DTAP: submit_dtap(conn, (struct msgb *)data); break; case GSCON_EV_TX_SCCP: gscon_sigtran_send(conn, (struct msgb *)data); break; default: OSMO_ASSERT(false); } } static void gscon_fsm_handover(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_subscriber_connection *conn = fi->priv; switch (event) { case GSCON_EV_HANDOVER_END: osmo_fsm_inst_state_chg(fi, ST_ACTIVE, 0, 0); gscon_dtap_queue_flush(conn, 1); return; case GSCON_EV_MO_DTAP: forward_dtap(conn, (struct msgb *)data, fi); break; case GSCON_EV_MT_DTAP: /* cache until handover is done */ submit_dtap(conn, (struct msgb *)data); break; case GSCON_EV_TX_SCCP: gscon_sigtran_send(conn, (struct msgb *)data); break; default: OSMO_ASSERT(false); } } static bool same_mgw_info(const struct mgcp_conn_peer *a, const struct mgcp_conn_peer *b) { if (!a || !b) return false; if (a == b) return true; if (strcmp(a->addr, b->addr)) return false; if (a->port != b->port) return false; if (a->call_id != b->call_id) return false; return true; } static struct mgcp_client *select_mgw(struct gsm_subscriber_connection *conn, struct gsm_lchan *for_lchan) { struct mgcp_client_pool_member *mgcp_pmemb; struct mgcp_client *mgcp_client; struct gsm_bts *bts = for_lchan->ts->trx->bts; /* If BTS is not pinned to a given MGW, let regular allocation which * spreads load over available MGWs: */ if (bts->mgw_pool_target == -1) goto pick_any; /* BTS is pinned to an MGW, retrieve pointer to it: */ mgcp_pmemb = mgcp_client_pool_find_member_by_nr(conn->network->mgw.mgw_pool, bts->mgw_pool_target); if (!mgcp_pmemb) { if (!bts->mgw_pool_target_strict) { LOGPFSML(conn->fi, LOGL_NOTICE, "mgw pool-target %u not found! selecting another one.\n", bts->mgw_pool_target); goto pick_any; } else { LOGPFSML(conn->fi, LOGL_ERROR, "mgw pool-target %u not found!\n", bts->mgw_pool_target); return NULL; } } if (mgcp_client_pool_member_is_blocked(mgcp_pmemb)) { if (!bts->mgw_pool_target_strict) { LOGPFSML(conn->fi, LOGL_NOTICE, "mgw pool-target %u is administratively blocked! selecting another one.\n", bts->mgw_pool_target); goto pick_any; } else { LOGPFSML(conn->fi, LOGL_ERROR, "mgw pool-target %u is administratively blocked!\n", bts->mgw_pool_target); return NULL; } } mgcp_client = mgcp_client_pool_member_get(mgcp_pmemb); if (!mgcp_client) { if (!bts->mgw_pool_target_strict) { LOGPFSML(conn->fi, LOGL_NOTICE, "mgw pool-target %u is not connected! selecting another one.\n", bts->mgw_pool_target); goto pick_any; } else { LOGPFSML(conn->fi, LOGL_ERROR, "mgw pool-target %u is not connected!\n", bts->mgw_pool_target); return NULL; } } return mgcp_client; pick_any: mgcp_client = mgcp_client_pool_get(conn->network->mgw.mgw_pool); return mgcp_client; } /* Make sure a conn->user_plane.mgw_endpoint is allocated with the proper mgw endpoint name. For * SCCPlite, pass in msc_assigned_cic the CIC received upon BSSMAP Assignment Command or BSSMAP Handover * Request form the MSC (which is only stored in conn->user_plane after success). Ignored for AoIP. */ struct osmo_mgcpc_ep *gscon_ensure_mgw_endpoint(struct gsm_subscriber_connection *conn, uint16_t msc_assigned_cic, struct gsm_lchan *for_lchan) { const char *epname; struct mgcp_client *mgcp_client = NULL; if (!conn) { LOG_LCHAN(for_lchan, LOGL_ERROR, "no conn!\n"); return NULL; } if (conn->user_plane.mgw_endpoint) return conn->user_plane.mgw_endpoint; if (gscon_is_sccplite(conn) || gscon_is_aoip(conn)) { /* Get MGCP client from pool */ mgcp_client = select_mgw(conn, for_lchan); if (!mgcp_client) { LOGPFSML(conn->fi, LOGL_ERROR, "cannot ensure MGW endpoint -- no MGW configured, check configuration!\n"); return NULL; } } if (gscon_is_sccplite(conn)) { /* derive endpoint name from CIC on A interface side */ conn->user_plane.mgw_endpoint = osmo_mgcpc_ep_alloc(conn->fi, GSCON_EV_FORGET_MGW_ENDPOINT, mgcp_client, conn->network->mgw.tdefs, conn->fi->id, "%x@%s", msc_assigned_cic, mgcp_client_endpoint_domain(mgcp_client)); LOGPFSML(conn->fi, LOGL_DEBUG, "MGW endpoint name derived from CIC 0x%x: %s\n", msc_assigned_cic, osmo_mgcpc_ep_name(conn->user_plane.mgw_endpoint)); } else if (gscon_is_aoip(conn)) { if (is_ipa_abisip_bts(for_lchan->ts->trx->bts)) /* use dynamic RTPBRIDGE endpoint allocation in MGW */ epname = mgcp_client_rtpbridge_wildcard(mgcp_client); else { uint8_t i460_bit_offs; if (for_lchan->ts->e1_link.e1_ts_ss == E1_SUBSLOT_FULL) i460_bit_offs = 0; else i460_bit_offs = for_lchan->ts->e1_link.e1_ts_ss * 2; epname = mgcp_client_e1_epname(conn, mgcp_client, for_lchan->ts->e1_link.e1_nr, for_lchan->ts->e1_link.e1_ts, 16, i460_bit_offs); } conn->user_plane.mgw_endpoint = osmo_mgcpc_ep_alloc(conn->fi, GSCON_EV_FORGET_MGW_ENDPOINT, mgcp_client, conn->network->mgw.tdefs, conn->fi->id, "%s", epname); } else { LOGPFSML(conn->fi, LOGL_ERROR, "Conn is neither SCCPlite nor AoIP!?\n"); return NULL; } return conn->user_plane.mgw_endpoint; } bool gscon_connect_mgw_to_msc(struct gsm_subscriber_connection *conn, struct gsm_lchan *for_lchan, const char *addr, uint16_t port, struct osmo_fsm_inst *notify, uint32_t event_success, uint32_t event_failure, void *notify_data, struct osmo_mgcpc_ep_ci **created_ci) { int rc; struct osmo_mgcpc_ep_ci *ci; struct mgcp_conn_peer mgw_info; enum mgcp_verb verb; if (created_ci) *created_ci = NULL; if (gscon_is_sccplite(conn)) { /* SCCPlite connection uses an MGW endpoint created by the MSC, so there is nothing to do * here. */ if (notify) osmo_fsm_inst_dispatch(notify, event_success, notify_data); return true; } mgw_info = (struct mgcp_conn_peer){ .port = port, .call_id = conn->sccp.conn.conn_id, .ptime = 20, .x_osmo_osmux_use = conn->assignment.req.use_osmux, .x_osmo_osmux_cid = conn->assignment.req.osmux_cid, }; mgcp_pick_codec(&mgw_info, for_lchan, false); rc = osmo_strlcpy(mgw_info.addr, addr, sizeof(mgw_info.addr)); if (rc <= 0 || rc >= sizeof(mgw_info.addr)) { LOGPFSML(conn->fi, LOGL_ERROR, "Failed to compose MGW endpoint address for MGW -> MSC\n"); return false; } ci = conn->user_plane.mgw_endpoint_ci_msc; if (ci) { const struct mgcp_conn_peer *prev_crcx_info = osmo_mgcpc_ep_ci_get_remote_rtp_info(ci); if (!conn->user_plane.mgw_endpoint) { LOGPFSML(conn->fi, LOGL_ERROR, "Internal error: conn has a CI but no endpoint\n"); return false; } if (!prev_crcx_info) { LOGPFSML(conn->fi, LOGL_ERROR, "There already is an MGW connection for the MSC side," " but it seems to be broken. Will not CRCX another one (%s)\n", osmo_mgcpc_ep_ci_name(ci)); return false; } if (same_mgw_info(&mgw_info, prev_crcx_info)) { LOGPFSML(conn->fi, LOGL_DEBUG, "MSC side MGW endpoint ci is already configured to %s\n", osmo_mgcpc_ep_ci_name(ci)); /* Immediately dispatch the success event */ osmo_fsm_inst_dispatch(notify, event_success, notify_data); return true; } verb = MGCP_VERB_MDCX; } else verb = MGCP_VERB_CRCX; gscon_ensure_mgw_endpoint(conn, for_lchan->activate.info.msc_assigned_cic, for_lchan); if (!conn->user_plane.mgw_endpoint) { LOGPFSML(conn->fi, LOGL_ERROR, "Unable to allocate endpoint info\n"); return false; } if (!ci) { ci = osmo_mgcpc_ep_ci_add(conn->user_plane.mgw_endpoint, "to-MSC"); if (created_ci) *created_ci = ci; conn->user_plane.mgw_endpoint_ci_msc = ci; } if (!ci) { LOGPFSML(conn->fi, LOGL_ERROR, "Unable to allocate endpoint CI info\n"); return false; } osmo_mgcpc_ep_ci_request(ci, verb, &mgw_info, notify, event_success, event_failure, notify_data); return true; } #define EV_TRANSPARENT_SCCP S(GSCON_EV_TX_SCCP) | S(GSCON_EV_MO_DTAP) | S(GSCON_EV_MT_DTAP) static const struct osmo_fsm_state gscon_fsm_states[] = { [ST_INIT] = { .name = "INIT", .in_event_mask = S(GSCON_EV_MO_COMPL_L3) | S(GSCON_EV_A_CONN_IND), .out_state_mask = 0 | S(ST_WAIT_INITIAL_USER_DATA) | S(ST_WAIT_CC) | S(ST_ACTIVE) | S(ST_WAIT_CLEAR_CMD) | S(ST_WAIT_SCCP_RLSD), .action = gscon_fsm_init, }, [ST_WAIT_INITIAL_USER_DATA] = { .name = "WAIT_INITIAL_USER_DATA", .in_event_mask = 0 | S(GSCON_EV_A_INITIAL_USER_DATA) | S(GSCON_EV_HANDOVER_END) , .out_state_mask = S(ST_WAIT_CC) | S(ST_ACTIVE) | S(ST_WAIT_CLEAR_CMD) | S(ST_WAIT_SCCP_RLSD), .action = gscon_fsm_wait_initial_user_data, }, [ST_WAIT_CC] = { .name = "WAIT_CC", .in_event_mask = S(GSCON_EV_A_CONN_CFM), .out_state_mask = S(ST_ACTIVE) | S(ST_WAIT_CLEAR_CMD) | S(ST_WAIT_SCCP_RLSD), .action = gscon_fsm_wait_cc, }, [ST_ACTIVE] = { .name = "ACTIVE", .in_event_mask = EV_TRANSPARENT_SCCP | S(GSCON_EV_ASSIGNMENT_START) | S(GSCON_EV_HANDOVER_START) | S(GSCON_EV_LCS_LOC_REQ_END) | S(GSCON_EV_MO_COMPL_L3) , .out_state_mask = S(ST_WAIT_CLEAR_CMD) | S(ST_WAIT_SCCP_RLSD) | S(ST_ASSIGNMENT) | S(ST_HANDOVER), .action = gscon_fsm_active, }, [ST_ASSIGNMENT] = { .name = "ASSIGNMENT", .in_event_mask = EV_TRANSPARENT_SCCP | S(GSCON_EV_ASSIGNMENT_END), .out_state_mask = S(ST_ACTIVE) | S(ST_WAIT_CLEAR_CMD) | S(ST_WAIT_SCCP_RLSD), .action = gscon_fsm_assignment, }, [ST_HANDOVER] = { .name = "HANDOVER", .in_event_mask = EV_TRANSPARENT_SCCP | S(GSCON_EV_HANDOVER_END), .out_state_mask = S(ST_ACTIVE) | S(ST_WAIT_CLEAR_CMD) | S(ST_WAIT_SCCP_RLSD), .action = gscon_fsm_handover, }, [ST_WAIT_CLEAR_CMD] = { .name = "WAIT_CLEAR_CMD", .onenter = gscon_fsm_wait_clear_cmd_onenter, .out_state_mask = S(ST_WAIT_SCCP_RLSD), }, [ST_WAIT_SCCP_RLSD] = { .name = "WAIT_SCCP_RLSD", .onenter = gscon_fsm_wait_sccp_rlsd_onenter, .in_event_mask = S(GSCON_EV_HANDOVER_END), }, }; void gscon_change_primary_lchan(struct gsm_subscriber_connection *conn, struct gsm_lchan *new_lchan) { /* On release, do not receive release events that look like the primary lchan is gone. */ struct gsm_lchan *old_lchan = conn->lchan; OSMO_ASSERT(new_lchan); if (old_lchan == new_lchan) return; if (!old_lchan) LOGPFSML(conn->fi, LOGL_DEBUG, "setting primary lchan for this conn to %s\n", new_lchan->fi? osmo_fsm_inst_name(new_lchan->fi) : gsm_lchan_name(new_lchan)); else LOGPFSML(conn->fi, LOGL_DEBUG, "primary lchan for this conn changes from %s to %s\n", old_lchan->fi? osmo_fsm_inst_name(old_lchan->fi) : gsm_lchan_name(old_lchan), new_lchan->fi? osmo_fsm_inst_name(new_lchan->fi) : gsm_lchan_name(new_lchan)); conn->lchan = new_lchan; conn->lchan->conn = conn; if (conn->lchan->fi_rtp) osmo_fsm_inst_dispatch(conn->lchan->fi_rtp, LCHAN_RTP_EV_ESTABLISHED, 0); if (old_lchan && (old_lchan != new_lchan)) gscon_release_lchan(conn, old_lchan, false, false, GSM48_RR_CAUSE_NORMAL); } void gscon_lchan_releasing(struct gsm_subscriber_connection *conn, struct gsm_lchan *lchan) { if (!lchan) return; if (conn->assignment.new_lchan == lchan) { if (conn->assignment.fi) osmo_fsm_inst_dispatch(conn->assignment.fi, ASSIGNMENT_EV_LCHAN_ERROR, lchan); lchan_forget_conn(conn->assignment.new_lchan); conn->assignment.new_lchan = NULL; } if (conn->ho.new_lchan == lchan) { if (conn->ho.fi) osmo_fsm_inst_dispatch(conn->ho.fi, HO_EV_LCHAN_ERROR, lchan); } if (conn->vgcs_chan.new_lchan == lchan) { if (conn->vgcs_chan.fi) osmo_fsm_inst_dispatch(conn->vgcs_chan.fi, VGCS_EV_LCHAN_ERROR, lchan); } if (conn->lchan == lchan) { lchan_forget_conn(conn->lchan); conn->lchan = NULL; } /* If the conn has no lchan anymore, it was released by the BTS and needs to Clear towards MSC. * However, if a Location Request is still busy, do not send Clear Request. */ if (!conn->lchan && !conn->lcs.loc_req) { switch (conn->fi->state) { case ST_WAIT_CC: /* The SCCP connection was not yet confirmed by a CC, the BSSAP is not fully established yet so we cannot release it. First wait for the CC, and release in gscon_fsm_wait_cc(). */ break; default: gscon_bssmap_clear(conn, GSM0808_CAUSE_EQUIPMENT_FAILURE); break; } } } /* An lchan was deallocated. */ void gscon_forget_lchan(struct gsm_subscriber_connection *conn, struct gsm_lchan *lchan) { const char *detach_label = NULL; if (!conn) return; if (!lchan) return; if (conn->assignment.new_lchan == lchan) { conn->assignment.new_lchan = NULL; detach_label = "assignment.new_lchan"; } if (conn->ho.new_lchan == lchan) { conn->ho.new_lchan = NULL; detach_label = "ho.new_lchan"; } if (conn->vgcs_chan.new_lchan == lchan) { conn->vgcs_chan.new_lchan = NULL; detach_label = "vgcs.new_lchan"; } if (conn->lchan == lchan) { conn->lchan = NULL; detach_label = "primary lchan"; } /* Log for both lchan FSM and conn FSM to ease reading the log in case of problems */ if (detach_label) { LOGPFSML(conn->fi, LOGL_DEBUG, "conn detaches lchan %s\n", lchan->fi? osmo_fsm_inst_name(lchan->fi) : gsm_lchan_name(lchan)); if (lchan->fi) LOGPFSML(lchan->fi, LOGL_DEBUG, "conn %s detaches lchan (%s)\n", osmo_fsm_inst_name(conn->fi), detach_label); } if (!conn->lchan && !conn->ho.new_lchan && !conn->assignment.new_lchan && !conn->vgcs_chan.new_lchan && !conn->lcs.loc_req) gscon_bssmap_clear(conn, GSM0808_CAUSE_EQUIPMENT_FAILURE); } static void gscon_forget_mgw_endpoint(struct gsm_subscriber_connection *conn) { struct mgcp_client *mgcp_client; /* Put MGCP client back into MGW pool */ mgcp_client = osmo_mgcpc_ep_client(conn->user_plane.mgw_endpoint); mgcp_client_pool_put(mgcp_client); /* Be sure that the endpoint CI we are maintaining in user_plane * is also removed from the other locations as well. */ gscon_forget_mgw_endpoint_ci(conn, conn->user_plane.mgw_endpoint_ci_msc); conn->user_plane.mgw_endpoint = NULL; conn->user_plane.mgw_endpoint_ci_msc = NULL; conn->ho.created_ci_for_msc = NULL; lchan_forget_mgw_endpoint(conn->lchan); lchan_forget_mgw_endpoint(conn->assignment.new_lchan); lchan_forget_mgw_endpoint(conn->vgcs_chan.new_lchan); lchan_forget_mgw_endpoint(conn->ho.new_lchan); } void gscon_forget_mgw_endpoint_ci(struct gsm_subscriber_connection *conn, struct osmo_mgcpc_ep_ci *ci) { if (conn->ho.created_ci_for_msc == ci) conn->ho.created_ci_for_msc = NULL; if (conn->user_plane.mgw_endpoint_ci_msc == ci) conn->user_plane.mgw_endpoint_ci_msc = NULL; if (conn->assignment.created_ci_for_msc == ci) conn->assignment.created_ci_for_msc = NULL; } static void gscon_fsm_allstate(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_subscriber_connection *conn = fi->priv; const struct tlv_parsed *tp; struct osmo_mobile_identity mi_imsi; /* Regular allstate event processing */ switch (event) { case GSCON_EV_A_CLEAR_CMD: OSMO_ASSERT(data); conn->clear_cause = *(const enum gsm0808_cause *)data; conn_fsm_state_chg(ST_WAIT_SCCP_RLSD); break; case GSCON_EV_A_DISC_IND: /* MSC or SIGTRAN network has hard-released SCCP connection, terminate the FSM now. * Cleanup is done in gscon_pre_term() and gscon_cleanup(). */ osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, data); break; case GSCON_EV_FORGET_MGW_ENDPOINT: gscon_forget_mgw_endpoint(conn); break; case GSCON_EV_RSL_CONN_FAIL: if (conn->lchan) { conn->lchan->release.in_error = true; conn->lchan->release.rsl_error_cause = data ? *(uint8_t*)data : RSL_ERR_IE_ERROR; conn->lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(conn->lchan->release.rsl_error_cause); } /* Request BSSMAP Clear, but do not abort an ongoing Location Request */ if (!conn->lcs.loc_req) gscon_bssmap_clear(conn, GSM0808_CAUSE_RADIO_INTERFACE_FAILURE); break; case GSCON_EV_MGW_MDCX_RESP_MSC: LOGPFSML(fi, LOGL_DEBUG, "Rx MDCX of MSC side (LCLS?)\n"); break; case GSCON_EV_LCLS_FAIL: break; case GSCON_EV_A_COMMON_ID_IND: OSMO_ASSERT(data); tp = data; if (osmo_mobile_identity_decode(&mi_imsi, TLVP_VAL(tp, GSM0808_IE_IMSI), TLVP_LEN(tp, GSM0808_IE_IMSI), false) || mi_imsi.type != GSM_MI_TYPE_IMSI) { LOGPFSML(fi, LOGL_ERROR, "CommonID: could not parse IMSI\n"); return; } if (!conn->bsub) conn->bsub = bsc_subscr_find_or_create_by_imsi(conn->network->bsc_subscribers, mi_imsi.imsi, BSUB_USE_CONN); else { /* we already have a bsc_subscr associated; maybe that subscriber has no IMSI yet? */ if (!conn->bsub->imsi[0]) bsc_subscr_set_imsi(conn->bsub, mi_imsi.imsi); } if (TLVP_PRESENT(tp, GSM0808_IE_LAST_USED_EUTRAN_PLMN_ID)) { conn->fast_return.allowed = true; /* Always allowed for CSFB */ conn->fast_return.last_eutran_plmn_valid = true; osmo_plmn_from_bcd(TLVP_VAL(tp, GSM0808_IE_LAST_USED_EUTRAN_PLMN_ID), &conn->fast_return.last_eutran_plmn); LOGPFSML(fi, LOGL_DEBUG, "subscr comes from E-UTRAN PLMN %s\n", osmo_plmn_name(&conn->fast_return.last_eutran_plmn)); } gscon_update_id(conn); break; default: OSMO_ASSERT(false); break; } } static void gscon_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause) { struct gsm_subscriber_connection *conn = fi->priv; lchan_forget_conn(conn->lchan); lchan_forget_conn(conn->assignment.new_lchan); lchan_forget_conn(conn->vgcs_chan.new_lchan); lchan_forget_conn(conn->ho.new_lchan); lb_close_conn(conn); if (conn->sccp.state != SUBSCR_SCCP_ST_NONE) { LOGPFSML(fi, LOGL_DEBUG, "Disconnecting SCCP\n"); struct bsc_msc_data *msc = conn->sccp.msc; /* FIXME: include a proper cause value / error message? */ osmo_sccp_tx_disconn(msc->a.sccp_user, conn->sccp.conn.conn_id, &msc->a.bsc_addr, 0); conn->sccp.state = SUBSCR_SCCP_ST_NONE; } if (conn->sccp.conn.conn_id != SCCP_CONN_ID_UNSET && conn->sccp.msc) { struct bsc_sccp_inst *bsc_sccp = osmo_sccp_get_priv(conn->sccp.msc->a.sccp); bsc_sccp_inst_unregister_gscon(bsc_sccp, &conn->sccp.conn); conn->sccp.conn.conn_id = SCCP_CONN_ID_UNSET; } if (conn->bsub) { LOGPFSML(fi, LOGL_DEBUG, "Putting bsc_subscr\n"); bsc_subscr_put(conn->bsub, BSUB_USE_CONN); conn->bsub = NULL; } llist_del(&conn->entry); talloc_free(conn); } static void gscon_pre_term(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause) { struct gsm_subscriber_connection *conn = fi->priv; struct mgcp_client *mgcp_client; /* Put MGCP client back into MGW pool */ mgcp_client = osmo_mgcpc_ep_client(conn->user_plane.mgw_endpoint); mgcp_client_pool_put(mgcp_client); osmo_mgcpc_ep_clear(conn->user_plane.mgw_endpoint); conn->user_plane.mgw_endpoint = NULL; conn->user_plane.mgw_endpoint_ci_msc = NULL; if (conn->ho.fi) osmo_fsm_inst_dispatch(conn->ho.fi, HO_EV_CONN_RELEASING, NULL); if (conn->lcs.loc_req) osmo_fsm_inst_dispatch(conn->lcs.loc_req->fi, LCS_LOC_REQ_EV_CONN_CLEAR, NULL); if (conn->lcls.fi) { /* request termination of LCLS FSM */ osmo_fsm_inst_term(conn->lcls.fi, cause, NULL); conn->lcls.fi = NULL; } if (conn->vgcs_call.fi) osmo_fsm_inst_dispatch(conn->vgcs_call.fi, VGCS_EV_CLEANUP, NULL); if (conn->vgcs_chan.fi) osmo_fsm_inst_dispatch(conn->vgcs_chan.fi, VGCS_EV_CLEANUP, NULL); LOGPFSML(fi, LOGL_DEBUG, "Releasing all lchans (if any) because this conn is terminating\n"); gscon_release_lchans(conn, true, bsc_gsm48_rr_cause_from_gsm0808_cause(conn->clear_cause)); /* drop pending messages */ gscon_dtap_queue_flush(conn, 0); penalty_timers_clear(&conn->hodec2.penalty_timers, NULL); } static int gscon_timer_cb(struct osmo_fsm_inst *fi) { struct gsm_subscriber_connection *conn = fi->priv; switch (fi->T) { case -3210: gscon_release_lchan(conn, conn->lchan, true, true, GSM48_RR_CAUSE_ABNORMAL_TIMER); /* MSC has not responded/confirmed connection with CC, this * could indicate a bad SCCP connection. We now inform the the * FSM that controls the BSSMAP reset about the event. Maybe * a BSSMAP reset is necessary. */ a_reset_conn_fail(conn->sccp.msc); /* Since we could not reach the MSC, we give up and terminate * the FSM instance now (N-DISCONNET.req is sent in * gscon_cleanup() above) */ osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); break; case -4: /* The MSC has sent a BSSMAP Clear Command, we acknowledged that, but the conn was never * disconnected. */ LOGPFSML(fi, LOGL_ERROR, "Long after expecting %s, the conn is still not" " released. For sanity, discarding this conn now.\n", fi->state == ST_WAIT_CLEAR_CMD ? "BSSMAP Clear Command" : "SCCP RLSD"); a_reset_conn_fail(conn->sccp.msc); osmo_fsm_inst_term(fi, OSMO_FSM_TERM_ERROR, NULL); break; default: LOGPFSML(fi, LOGL_ERROR, "Unknown timer %d expired\n", fi->T); OSMO_ASSERT(false); } return 0; } static struct osmo_fsm gscon_fsm = { .name = "SUBSCR_CONN", .states = gscon_fsm_states, .num_states = ARRAY_SIZE(gscon_fsm_states), .allstate_event_mask = S(GSCON_EV_A_DISC_IND) | S(GSCON_EV_A_CLEAR_CMD) | S(GSCON_EV_A_COMMON_ID_IND) | S(GSCON_EV_RSL_CONN_FAIL) | S(GSCON_EV_LCLS_FAIL) | S(GSCON_EV_FORGET_LCHAN) | S(GSCON_EV_FORGET_MGW_ENDPOINT), .allstate_action = gscon_fsm_allstate, .cleanup = gscon_cleanup, .pre_term = gscon_pre_term, .timer_cb = gscon_timer_cb, .log_subsys = DMSC, .event_names = gscon_fsm_event_names, }; static __attribute__((constructor)) void bsc_subscr_conn_fsm_init(void) { OSMO_ASSERT(osmo_fsm_register(&gscon_fsm) == 0); OSMO_ASSERT(osmo_fsm_register(&lcls_fsm) == 0); } /* Allocate a subscriber connection and its associated FSM */ struct gsm_subscriber_connection *bsc_subscr_con_allocate(struct gsm_network *net) { struct gsm_subscriber_connection *conn; conn = talloc_zero(net, struct gsm_subscriber_connection); if (!conn) return NULL; conn->network = net; INIT_LLIST_HEAD(&conn->dtap_queue); INIT_LLIST_HEAD(&conn->hodec2.penalty_timers); bscp_sccp_conn_node_init(&conn->sccp.conn, conn); bscp_sccp_conn_node_init(&conn->lcs.lb.conn, conn); /* Default clear cause (on RR translates to GSM48_RR_CAUSE_ABNORMAL_UNSPEC) */ conn->clear_cause = GSM0808_CAUSE_EQUIPMENT_FAILURE; /* don't allocate from 'conn' context, as gscon_cleanup() will call talloc_free(conn) before * libosmocore will call talloc_free(conn->fi), i.e. avoid use-after-free during cleanup */ conn->fi = osmo_fsm_inst_alloc(&gscon_fsm, net, conn, LOGL_DEBUG, NULL); if (!conn->fi) { talloc_free(conn); return NULL; } /* indicate "IE not [yet] received" */ conn->lcls.config = GSM0808_LCLS_CFG_NA; conn->lcls.control = GSM0808_LCLS_CSC_NA; conn->lcls.fi = osmo_fsm_inst_alloc_child(&lcls_fsm, conn->fi, GSCON_EV_LCLS_FAIL); if (!conn->lcls.fi) { osmo_fsm_inst_term(conn->fi, OSMO_FSM_TERM_ERROR, NULL); return NULL; } conn->lcls.fi->priv = conn; llist_add_tail(&conn->entry, &net->subscr_conns); return conn; } static void gsm0808_send_rsl_dtap(struct gsm_subscriber_connection *conn, struct msgb *msg, int link_id, int allow_sacch); #define GSCON_DTAP_QUEUE_MSGB_CB_LINK_ID 0 #define GSCON_DTAP_QUEUE_MSGB_CB_ALLOW_SACCH 1 static void gscon_dtap_queue_add(struct gsm_subscriber_connection *conn, struct msgb *msg, int link_id, bool allow_sacch) { if (conn->dtap_queue_len >= 8) { LOGP(DMSC, LOGL_ERROR, "%s: Cannot queue more DTAP messages," " already reached sane maximum of %u queued messages\n", bsc_subscr_name(conn->bsub), conn->dtap_queue_len); msgb_free(msg); return; } conn->dtap_queue_len ++; LOGP(DMSC, LOGL_DEBUG, "%s: Queueing DTAP message during handover/assignment (%u)\n", bsc_subscr_name(conn->bsub), conn->dtap_queue_len); msg->cb[GSCON_DTAP_QUEUE_MSGB_CB_LINK_ID] = (unsigned long)link_id; msg->cb[GSCON_DTAP_QUEUE_MSGB_CB_ALLOW_SACCH] = allow_sacch ? 1 : 0; msgb_enqueue(&conn->dtap_queue, msg); } static void gscon_dtap_queue_flush(struct gsm_subscriber_connection *conn, int send) { struct msgb *msg; unsigned int flushed_count = 0; while ((msg = msgb_dequeue(&conn->dtap_queue))) { conn->dtap_queue_len --; flushed_count ++; if (send) { int link_id = (int)msg->cb[GSCON_DTAP_QUEUE_MSGB_CB_LINK_ID]; bool allow_sacch = !!msg->cb[GSCON_DTAP_QUEUE_MSGB_CB_ALLOW_SACCH]; LOGPFSML(conn->fi, LOGL_DEBUG, "%s: Sending queued DTAP message after handover/assignment (%u/%u)\n", bsc_subscr_name(conn->bsub), flushed_count, conn->dtap_queue_len); gsm0808_send_rsl_dtap(conn, msg, link_id, allow_sacch); } else msgb_free(msg); } } static void rll_ind_cb(struct gsm_lchan *lchan, uint8_t link_id, void *_data, enum bsc_rllr_ind rllr_ind) { struct msgb *msg = _data; /* * There seems to be a small window that the RLL timer can * fire after a lchan_release call and before the S_CHALLOC_FREED * is called. Check if a conn is set before proceeding. */ if (!lchan->conn) { msgb_free(msg); return; } switch (rllr_ind) { case BSC_RLLR_IND_EST_CONF: rsl_data_request(msg, link_id); break; case BSC_RLLR_IND_REL_IND: bsc_sapi_n_reject(lchan->conn, RSL_LINK_ID2DLCI(link_id), GSM0808_CAUSE_MS_NOT_EQUIPPED); msgb_free(msg); break; case BSC_RLLR_IND_ERR_IND: case BSC_RLLR_IND_TIMEOUT: bsc_sapi_n_reject(lchan->conn, RSL_LINK_ID2DLCI(link_id), GSM0808_CAUSE_BSS_NOT_EQUIPPED); msgb_free(msg); break; default: LOGPLCHAN(lchan, DRLL, LOGL_NOTICE, "Received unknown rllr_ind %u\n", rllr_ind); msgb_free(msg); break; } } /*! \brief process incoming 08.08 DTAP from MSC (send via BTS to MS) */ static void gsm0808_send_rsl_dtap(struct gsm_subscriber_connection *conn, struct msgb *msg, int link_id, int allow_sacch) { uint8_t sapi; int rc; if (!conn->lchan) { LOGP(DMSC, LOGL_ERROR, "%s Called submit dtap without an lchan.\n", bsc_subscr_name(conn->bsub)); msgb_free(msg); rc = -EINVAL; goto failed_to_send; } sapi = link_id & 0x7; msg->lchan = conn->lchan; /* If we are on a TCH and need to submit a SMS (on SAPI=3) we need to use the SACH */ if (allow_sacch && sapi != 0) { if (conn->lchan->type == GSM_LCHAN_TCH_F || conn->lchan->type == GSM_LCHAN_TCH_H) link_id |= 0x40; } msg->l3h = msg->data; /* is requested SAPI already up? */ if (conn->lchan->sapis[sapi] == LCHAN_SAPI_UNUSED) { /* Establish L2 for additional SAPI */ OBSC_LINKID_CB(msg) = link_id; rc = rll_establish(msg->lchan, sapi, rll_ind_cb, msg); if (rc) { msgb_free(msg); bsc_sapi_n_reject(conn, RSL_LINK_ID2DLCI(link_id), GSM0808_CAUSE_BSS_NOT_EQUIPPED); goto failed_to_send; } return; } else { /* Directly forward via RLL/RSL to BTS */ rc = rsl_data_request(msg, link_id); if (rc) goto failed_to_send; } return; failed_to_send: LOGPFSML(conn->fi, LOGL_ERROR, "Tx BSSMAP CLEAR REQUEST to MSC\n"); gscon_bssmap_clear(conn, GSM0808_CAUSE_EQUIPMENT_FAILURE); } void gscon_submit_rsl_dtap(struct gsm_subscriber_connection *conn, struct msgb *msg, int link_id, int allow_sacch) { /* buffer message during assignment / handover */ if (conn->fi->state != ST_ACTIVE) { gscon_dtap_queue_add(conn, msg, link_id, !! allow_sacch); return; } gsm0808_send_rsl_dtap(conn, msg, link_id, allow_sacch); } /* Compose an FSM ID, if possible from the current subscriber information */ void gscon_update_id(struct gsm_subscriber_connection *conn) { osmo_fsm_inst_update_id_f(conn->fi, "msc%u-conn%u%s%s", conn->sccp.msc ? conn->sccp.msc->nr : UINT_MAX, conn->sccp.conn.conn_id, conn->bsub? "_" : "", conn->bsub? bsc_subscr_id(conn->bsub) : ""); } bool gscon_is_aoip(struct gsm_subscriber_connection *conn) { if (!conn || !conn->sccp.msc) return false; return msc_is_aoip(conn->sccp.msc); } bool gscon_is_sccplite(struct gsm_subscriber_connection *conn) { if (!conn || !conn->sccp.msc) return false; return msc_is_sccplite(conn->sccp.msc); }