/* Handle VGCS/VBCS calls. (Voice Group/Broadcast Call Service). */ /* * (C) 2023 by sysmocom - s.f.m.c. GmbH * All Rights Reserved * * SPDX-License-Identifier: AGPL-3.0+ * * Author: Andreas Eversberg * * 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 . */ /* The process consists of four state machines: * * The call control state machine "GCC" handles the voice group/broadcast call. * There is one instance for every call. It is mainly controlled by the calling * subscriber. The state machine is described in 3GPP TS 44.068 / 44.069. * One SCCP connection to the calling subscriber is associated with the state * machine. Once the calling subscriber leaves or is assigned to the VGCS/VBS * channel, the association to the MSC-A role is removed and the SCCP connection * is closed. The state machine with the transaction still exists until the end * of the call. * * The BSS control state machine "vgcs_bss_fsm" handles the call in each BSC. * There are as many instances as there are BSCs where the call is placed to. * The instances are linked to the call control in a 1:n relation. * One SCCP connection for every BSC is associated with the state machine. * It sets up the call in the BSC and handles the uplink control and signaling * with the talking phone. * * The resource controling state machine "vgcs_cell_fsm" handles the channel for * each BTS that has a VGCS for the call. The instances are linked to the BSS * control in a 1:n relation. * One SCCP connection for every cell is associated with each list entry. * It assigns the VGCS/VBS channel and the conference bridge in the MGW. * * The MGW endpoint state machine "vgcs_mgw_ep_fsm" handles the endpoint * connection for each call. It controls the clearing of the MGW connections * in case of endpoint failure. All instances of the resource controlling state * machine are linked to this state machine in a 1:n relation. * * Setup of a call: * * When the calling subscriber dials a group/broadcast call, the GCR is checked * for an existing Group ID. If it exists, the call is setup towards the a given * list of MSCs for this Group ID. Also the channels are assigned for a given * list of cells for this Group ID. * The call can also be initiated via VTY. * * Then the calling subscriber is assigned to the VGCS channel of the same cell * where the call was initialized. Afterwards the call is connected. The calling * subscriber may then stay on the uplink or release it. * * Uplink control: * * Any BSC may indicate a talking subscriber. If there is no talking subscriber * yet, the uplink is granted, otherwise it is rejected. If the uplink is in * use on one BSC, all other BSCs will be blocked. If the uplink becomes free, * all other BSCs will be unblocked. * * Termination of the call: * * The calling subscriber accesses the uplink. The it sends a termination * request. This request is acknowledged by a termination command towards * the calling subscriber. The call is cleared. * The call can also be terminated via VTY and/or a timeout. * */ #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 LOG_GCC(trans, level, fmt, args...) \ LOGP((trans) ? ((trans->type == TRANS_GCC) ? DGCC : DBCC) : DASCI, level, \ (trans) ? ((trans->type == TRANS_GCC) ? ("GCC callref %s: " fmt) : ("BCC callref %s: " fmt)) : "%s" fmt, \ (trans) ? gsm44068_group_id_string(trans->callref) : "", ##args) #define LOG_BSS(bss, level, fmt, args...) \ LOGP(DASCI, level, \ (bss->trans_type == TRANS_GCC) ? ("GCC callref %s, BSS #%s: " fmt) : ("BCC callref %s, BSS #%s: " fmt), \ gsm44068_group_id_string(bss->callref), osmo_ss7_pointcode_print(NULL, bss->pc), ##args) #define LOG_CELL(cell, level, fmt, args...) \ LOGP(DASCI, level, \ (cell->trans_type == TRANS_GCC) ? ("GCC callref %s, BSS #%s, CID %d: " fmt) \ : ("BCC callref %s, BSS #%s, CID %d: " fmt), \ gsm44068_group_id_string(cell->callref), osmo_ss7_pointcode_print(NULL, cell->pc), cell->cell_id, ##args) static struct osmo_fsm vgcs_bcc_fsm; static struct osmo_fsm vgcs_gcc_fsm; static struct osmo_fsm vgcs_bss_fsm; static struct osmo_fsm vgcs_cell_fsm; static struct osmo_fsm vgcs_mgw_ep_fsm; static __attribute__((constructor)) void vgcs_fsm_init(void) { OSMO_ASSERT(osmo_fsm_register(&vgcs_bcc_fsm) == 0); OSMO_ASSERT(osmo_fsm_register(&vgcs_gcc_fsm) == 0); OSMO_ASSERT(osmo_fsm_register(&vgcs_bss_fsm) == 0); OSMO_ASSERT(osmo_fsm_register(&vgcs_cell_fsm) == 0); OSMO_ASSERT(osmo_fsm_register(&vgcs_mgw_ep_fsm) == 0); } const char *gsm44068_group_id_string(uint32_t callref) { static char string[9]; snprintf(string, sizeof(string), "%08u", callref); string[sizeof(string) - 1] = '\0'; return string; } /* Resolve ran peer from point-code */ static struct ran_peer *ran_peer_for_pc(struct gsm_network *msc_network, int pc) { struct sccp_ran_inst *sri; struct osmo_sccp_addr addr = {}; struct ran_peer *rp; sri = msc_network->a.sri; if (!osmo_sccp_get_ss7(sri->sccp)) { LOGP(DASCI, LOGL_ERROR, "No SS7???\n"); return NULL; } osmo_sccp_make_addr_pc_ssn(&addr, pc, sri->ran->ssn); rp = ran_peer_find_by_addr(sri, &addr); return rp; } /* Encode message and send towards BSC. */ int ran_encode_and_send(struct osmo_fsm_inst *fi, struct ran_msg *ran_msg, struct ran_conn *conn, bool initial) { struct msgb *l3_msg; int rc; l3_msg = ran_a_encode(fi, ran_msg); if (!l3_msg) { LOGP(DASCI, LOGL_ERROR, "ran_a_encode() failed.\n"); return -EINVAL; } rc = ran_conn_down_l2_co(conn, l3_msg, initial); msgb_free(l3_msg); return rc; } /* Transmit DTAP message to talker * This is used for sending group/broadcast call control messages. */ int tx_dtap_to_talker(struct vgcs_bss *bss, struct msgb *l3_msg) { struct ran_msg ran_msg; struct gsm48_hdr *gh = msgb_l3(l3_msg) ? : l3_msg->data; uint8_t pdisc = gsm48_hdr_pdisc(gh); int rc; LOG_BSS(bss, LOGL_DEBUG, "Sending DTAP: %s %s\n", gsm48_pdisc_name(pdisc), gsm48_pdisc_msgtype_name(pdisc, gsm48_hdr_msg_type(gh))); ran_msg = (struct ran_msg){ .msg_type = RAN_MSG_DTAP, .dtap = l3_msg, }; rc = ran_encode_and_send(bss->fi, &ran_msg, bss->conn, false); return rc; } /* * GCC/BCC Message transcoding */ static void _add_cause_ie(struct msgb *msg, uint8_t cause, uint8_t *diag, uint8_t diag_len) { uint8_t *ie = msgb_put(msg, 2 + diag_len); ie[0] = 1 + diag_len; ie[1] = cause; if (diag && diag_len) { ie[1] |= 0x80; memcpy(ie + 2, diag, diag_len); } } static void _add_callref_ie(struct msgb *msg, uint32_t callref, bool with_prio, uint8_t prio) { uint32_t ie; ie = callref << 5; if (with_prio) ie |= 0x10 | (prio << 1); msgb_put_u32(msg, ie); } static int _msg_too_short(void) { LOGP(DASCI, LOGL_ERROR, "MSG too short.\n"); return -EINVAL; } static int _ie_invalid(void) { LOGP(DASCI, LOGL_ERROR, "IE invalid.\n"); return -EINVAL; } static int _rx_callref(uint8_t *ie, unsigned int remaining_len, uint32_t *callref, bool *with_prio, uint8_t *prio) { uint8_t ie_len; ie_len = sizeof(uint32_t); if (remaining_len < ie_len) return _msg_too_short(); *callref = osmo_load32be(ie) >> 5; if (ie[3] & 0x10) { *with_prio = true; *prio = (ie[3] >> 1) & 0x7; } else *with_prio = false; return ie_len; } /* 3GPP TS 44.068 Clause 8.1 */ static int gsm44068_tx_connect(struct gsm_trans *trans, uint8_t pdisc, uint32_t callref, bool with_prio, uint8_t prio, uint8_t oi, uint8_t talker_prio, bool with_sms, uint8_t sms_dc, uint8_t sms_gp) { struct msgb *msg = gsm44068_msgb_alloc_name("GSM 44.068 TX CONNECT"); struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); uint8_t ie; gh->proto_discr = pdisc; gh->msg_type = OSMO_GSM44068_MSGT_CONNECT; _add_callref_ie(msg, callref, with_prio, prio); ie = (talker_prio << 4) | oi; msgb_put_u8(msg, ie); if (with_sms) { ie = OSMO_GSM44068_IEI_SMS_INDICATIONS | (sms_dc << 1) | sms_gp; msgb_put_u8(msg, ie); } /* Send to calling subscriber, depending on the link he is. */ if (trans->msc_a) return msc_a_tx_dtap_to_i(trans->msc_a, msg); if (trans->gcc.uplink_bss) return tx_dtap_to_talker(trans->gcc.uplink_bss, msg); msgb_free(msg); return -EIO; } /* The Get Status procedure is not used by the current implementation. * It is commented out, so it can be used in the future. * The idea is to have a complete set of GCC/BCC message transcoding. */ #if 0 /* 3GPP TS 44.068 Clause 8.2 */ static int gsm44068_tx_get_status(struct gsm_trans *trans, uint8_t pdisc, struct osmo_mobile_identity *mi) { struct msgb *msg = gsm44068_msgb_alloc_name("GSM 44.068 TX GET STATUS"); struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); gh->proto_discr = pdisc; gh->msg_type = OSMO_GSM44068_MSGT_GET_STATUS; if (mi) { uint8_t *l; int rc; l = msgb_tl_put(msg, OSMO_GSM44068_IEI_MOBILE_IDENTITY); rc = osmo_mobile_identity_encode_msgb(msg, mi, false); if (rc < 0) { msgb_free(msg); return -EINVAL; } *l = rc; } /* Send to calling subscriber, depending on the link he is. */ if (trans->msc_a) return msc_a_tx_dtap_to_i(trans->msc_a, msg); if (trans->gcc.uplink_bss) return tx_dtap_to_talker(trans->gcc.uplink_bss, msg); msgb_free(msg); return -EIO; } #endif /* 3GPP TS 44.068 Clause 8.3 and 8.3a */ static int gsm44068_rx_immediate_setup(struct msgb *msg, uint8_t *talker_prio, uint8_t *key_seq, struct gsm48_classmark2 *cm2, struct osmo_mobile_identity *mi, uint32_t *callref, bool *with_prio, uint8_t *prio, char *user_user) { struct gsm48_hdr *gh = msgb_l3(msg); unsigned int remaining_len = msgb_l3len(msg) - sizeof(*gh); uint8_t *ie = gh->data; uint8_t ie_len; uint64_t otdi; int i; int rc; /* Talker priority / Cyphering key sequence */ if (remaining_len < 1) return _msg_too_short(); *talker_prio = ie[0] & 0x07; *key_seq = (ie[0] >> 4) & 0x07; remaining_len -= 1; ie += 1; /* Mobile station classmark 2 */ if (remaining_len < 4) return _msg_too_short(); ie_len = ie[0]; if (remaining_len < ie_len + 1) return _msg_too_short(); if (ie_len != 3) return _ie_invalid(); memcpy(cm2, ie + 1, ie_len); remaining_len -= ie_len + 1; ie += ie_len + 1; /* Mobile indentity */ if (gh->msg_type == OSMO_GSM44068_MSGT_IMMEDIATE_SETUP) { /* IMMEDIATE SETUP uses IMSI/TMSI */ if (remaining_len < 2) return _msg_too_short(); ie_len = ie[0]; if (remaining_len < ie_len + 1) return _msg_too_short(); rc = osmo_mobile_identity_decode(mi, ie + 1, ie_len, false); if (rc) { LOGP(DMM, LOGL_ERROR, "Failure to decode Mobile Identity in GCC/BCC IMMEDDIATE SETUP" " (rc=%d)\n", rc); return -EINVAL; } remaining_len -= ie_len + 1; ie += ie_len + 1; } else { /* IMMEDIATE SETUP 2 uses TMSI only */ if (remaining_len < 4) return _msg_too_short(); mi->type = GSM_MI_TYPE_TMSI; mi->tmsi = osmo_load32be(ie); remaining_len -= 4; ie += 4; } /* Call reference */ rc = _rx_callref(ie, remaining_len, callref, with_prio, prio); if (rc < 0) return rc; remaining_len -= rc; ie += rc; /* OTID */ if (gh->msg_type == OSMO_GSM44068_MSGT_IMMEDIATE_SETUP_2 && user_user) { ie_len = 5; if (remaining_len < ie_len) return _msg_too_short(); otdi = osmo_load32be(ie + 1) | ((uint64_t)ie[0] << 32); for (i = 0; i < 12; i++) { user_user[i] = (otdi % 10) + '0'; otdi /= 10; } user_user[i] = '\0'; remaining_len -= ie_len; ie += ie_len; } else if (user_user) user_user[0] = '\0'; return 0; } /* 3GPP TS 44.068 Clause 8.4 */ static int gsm44068_tx_set_parameter(struct gsm_trans *trans, uint8_t pdisc, uint8_t da, uint8_t ua, uint8_t comm, uint8_t oi) { struct msgb *msg = gsm44068_msgb_alloc_name("GSM 44.068 TX SET PARAMETER"); struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); uint8_t ie; gh->proto_discr = pdisc; gh->msg_type = OSMO_GSM44068_MSGT_SET_PARAMETER; ie = (da << 3) | (ua << 2) | (comm << 1) | oi; msgb_put_u8(msg, ie); /* Send to calling subscriber, depending on the link he is. */ if (trans->msc_a) return msc_a_tx_dtap_to_i(trans->msc_a, msg); if (trans->gcc.uplink_bss) return tx_dtap_to_talker(trans->gcc.uplink_bss, msg); msgb_free(msg); return -EIO; } /* 3GPP TS 44.068 Clause 8.5 */ static int gsm44068_rx_setup(struct msgb *msg, bool *with_talker_prio, uint8_t *talker_prio, uint32_t *callref, bool *with_prio, uint8_t *prio, char *user_user) { struct gsm48_hdr *gh = msgb_l3(msg); unsigned int remaining_len = msgb_l3len(msg) - sizeof(*gh); uint8_t *ie = gh->data; struct tlv_parsed tp; struct tlv_p_entry *tlv; int rc; /* Call reference */ rc = _rx_callref(ie, remaining_len, callref, with_prio, prio); if (rc < 0) return rc; remaining_len -= rc; ie += rc; rc = tlv_parse(&tp, &osmo_gsm44068_att_tlvdef, ie, remaining_len, 0, 0); if (rc < 0) return _ie_invalid(); /* User-user */ tlv = TLVP_GET(&tp, OSMO_GSM44068_IEI_USER_USER); if (tlv && tlv->len && tlv->len <= 1 + 12 && user_user) { memcpy(user_user, tlv->val, tlv->len - 1); user_user[tlv->len - 1] = '\0'; } /* Talker priority */ tlv = TLVP_GET(&tp, OSMO_GSM44068_IEI_TALKER_PRIORITY); if (tlv && tlv->len) { *with_talker_prio = true; *talker_prio = tlv->val[0] & 0x07; } else *with_talker_prio = false; return 0; } /* 3GPP TS 44.068 Clause 8.6 */ static int gsm44068_rx_status(struct msgb *msg, uint8_t *cause, uint8_t *diag, uint8_t *diag_len, bool *with_call_state, enum osmo_gsm44068_call_state *call_state, bool *with_state_attrs, uint8_t *da, uint8_t *ua, uint8_t *comm, uint8_t *oi) { struct gsm48_hdr *gh = msgb_l3(msg); unsigned int remaining_len = msgb_l3len(msg) - sizeof(*gh); uint8_t *ie = gh->data; uint8_t ie_len; struct tlv_parsed tp; struct tlv_p_entry *tlv; int rc; /* Cause */ if (remaining_len < 2 || ie[0] < remaining_len - 2) return _msg_too_short(); ie_len = ie[0]; if (remaining_len < ie_len + 1) return _msg_too_short(); if (ie_len < 1) return _ie_invalid(); *cause = ie[1] & 0x7f; *diag_len = ie_len - 1; if (*diag_len) memcpy(diag, ie + 2, ie_len - 1); remaining_len -= ie_len + 1; ie += ie_len + 1; rc = tlv_parse(&tp, &osmo_gsm44068_att_tlvdef, ie, remaining_len, 0, 0); if (rc < 0) return _ie_invalid(); /* Call state */ tlv = TLVP_GET(&tp, OSMO_GSM44068_IEI_CALL_STATE); if (tlv) { *with_call_state = true; *call_state = tlv->val[0] & 0x7; } else *with_call_state = false; /* State attributes */ tlv = TLVP_GET(&tp, OSMO_GSM44068_IEI_STATE_ATTRIBUTES); if (tlv) { *with_state_attrs = true; *da = (tlv->val[0] >> 3) & 0x1; *ua = (tlv->val[0] >> 2) & 0x1; *comm = (tlv->val[0] >> 1) & 0x1; *oi = tlv->val[0] & 0x1; } else *with_state_attrs = false; return 0; } /* 3GPP TS 44.068 Clause 8.7 and 8.8 */ static int gsm44068_tx_termination(struct msc_a *msc_a, struct vgcs_bss *bss, uint8_t pdisc, uint8_t msg_type, uint8_t cause, uint8_t *diag, uint8_t diag_len) { struct msgb *msg = gsm44068_msgb_alloc_name("GSM 44.068 TX TERMINATION"); struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); gh->proto_discr = pdisc; gh->msg_type = msg_type; _add_cause_ie(msg, cause, diag, diag_len); /* Send to calling subscriber, depending on the link he is. */ if (msc_a) return msc_a_tx_dtap_to_i(msc_a, msg); if (bss) return tx_dtap_to_talker(bss, msg); msgb_free(msg); return -EIO; } /* 3GPP TS 44.068 Clause 8.9 */ static int gsm44068_rx_termination_req(struct msgb *msg, uint32_t *callref, bool *with_prio, uint8_t *prio, bool *with_talker_prio, uint8_t *talker_prio) { struct gsm48_hdr *gh = msgb_l3(msg); unsigned int remaining_len = msgb_l3len(msg) - sizeof(*gh); uint8_t *ie = gh->data; struct tlv_parsed tp; struct tlv_p_entry *tlv; int rc; /* Call reference */ rc = _rx_callref(ie, remaining_len, callref, with_prio, prio); if (rc < 0) return rc; remaining_len -= rc; ie += rc; rc = tlv_parse(&tp, &osmo_gsm44068_att_tlvdef, ie, remaining_len, 0, 0); if (rc < 0) return _ie_invalid(); /* Talker priority */ tlv = TLVP_GET(&tp, OSMO_GSM44068_IEI_TALKER_PRIORITY); if (tlv && tlv->len) { *with_talker_prio = true; *talker_prio = tlv->val[0] & 0x07; } else *with_talker_prio = false; return 0; } /* * GCC/BCC state machine - handles calling subscriber process */ static const struct value_string vgcs_gcc_fsm_event_names[] = { OSMO_VALUE_STRING(VGCS_GCC_EV_NET_SETUP), OSMO_VALUE_STRING(VGCS_GCC_EV_NET_TERM), OSMO_VALUE_STRING(VGCS_GCC_EV_USER_SETUP), OSMO_VALUE_STRING(VGCS_GCC_EV_USER_TERM), OSMO_VALUE_STRING(VGCS_GCC_EV_BSS_ESTABLISHED), OSMO_VALUE_STRING(VGCS_GCC_EV_BSS_ASSIGN_CPL), OSMO_VALUE_STRING(VGCS_GCC_EV_BSS_ASSIGN_FAIL), OSMO_VALUE_STRING(VGCS_GCC_EV_BSS_RELEASED), OSMO_VALUE_STRING(VGCS_GCC_EV_TIMEOUT), { } }; static int gcc_establish_bss(struct gsm_trans *trans) { struct gsm_network *net = trans->net; struct vgcs_mgw_ep *mgw = NULL; struct mgcp_client *mgcp_client; struct gcr *gcr; struct gcr_bss *b; struct gcr_cell *c; struct vgcs_bss *bss; struct vgcs_bss_cell *cell; struct osmo_fsm_inst *fi; struct ran_peer *rp; /* Failure should not happen, because it has been checked before. */ gcr = gcr_by_callref(trans->net, trans->type, trans->callref); if (!gcr) return -EINVAL; /* Allocate MGW endpoint. */ mgcp_client = mgcp_client_pool_get(trans->net->mgw.mgw_pool); if (!mgcp_client) { LOG_GCC(trans, LOGL_ERROR, "No MGW client, please check config.\n"); goto err_mgw; } fi = osmo_fsm_inst_alloc(&vgcs_mgw_ep_fsm, net, NULL, LOGL_DEBUG, NULL); if (!fi) { LOG_GCC(trans, LOGL_ERROR, "No memory for VGCS MSG state machine.\n"); goto err_mgw; } osmo_fsm_inst_update_id(fi, "vgcs-mgw-ep"); osmo_fsm_inst_state_chg(fi, VGCS_MGW_EP_ST_ACTIVE, 0, 0); mgw = talloc_zero(fi, struct vgcs_mgw_ep); if (!mgw) { LOG_GCC(trans, LOGL_ERROR, "No memory for MGW ep structure.\n"); osmo_fsm_inst_free(fi); goto err_mgw; } mgw->fi = fi; fi->priv = mgw; INIT_LLIST_HEAD(&mgw->cell_list); mgw->mgw_ep = osmo_mgcpc_ep_alloc(mgw->fi, VGCS_MGW_EP_EV_FREE, mgcp_client, trans->net->mgw.tdefs, mgw->fi->id, "%s", mgcp_client_rtpbridge_wildcard(mgcp_client)); if (!mgw->mgw_ep) { LOG_GCC(trans, LOGL_ERROR, "No memory for MGW endpoint state machine.\n"); goto err_mgw; } /* Create BSS list structures. */ LOG_GCC(trans, LOGL_DEBUG, "Creating BSS list structure with cell list structures.\n"); llist_for_each_entry(b, &gcr->bss_list, list) { LOG_GCC(trans, LOGL_DEBUG, " -> BSS with PC %s.\n", osmo_ss7_pointcode_print(NULL, b->pc)); /* Resolve ran_peer. */ rp = ran_peer_for_pc(trans->net, b->pc); if (!rp) { LOG_GCC(trans, LOGL_ERROR, "Failed to resolve point code %s, skipping BSS!\n", osmo_ss7_pointcode_print(NULL, b->pc)); continue; } /* Create state machine. */ fi = osmo_fsm_inst_alloc(&vgcs_bss_fsm, net, NULL, LOGL_DEBUG, NULL); if (!fi) { LOG_GCC(trans, LOGL_ERROR, "No memory for state machine.\n"); break; } /* Create call structure. */ bss = talloc_zero(fi, struct vgcs_bss); if (!bss) { LOG_GCC(trans, LOGL_ERROR, "No memory for BSS call structure.\n"); osmo_fsm_inst_free(fi); break; } bss->fi = fi; fi->priv = bss; INIT_LLIST_HEAD(&bss->cell_list); bss->trans = trans; bss->trans_type = trans->type; bss->callref = trans->callref; bss->pc = b->pc; /* Create ran connection. */ bss->conn = ran_conn_create_outgoing(rp); if (!bss->conn) { LOG_GCC(trans, LOGL_ERROR, "Failed to create RAN connection.\n"); osmo_fsm_inst_free(bss->fi); continue; } bss->conn->vgcs.bss = bss; /* Create cell list structures. */ llist_for_each_entry(c, &b->cell_list, list) { LOG_GCC(trans, LOGL_DEBUG, " -> Cell ID %d.\n", c->cell_id); /* Create state machine. */ fi = osmo_fsm_inst_alloc(&vgcs_cell_fsm, net, NULL, LOGL_DEBUG, NULL); if (!fi) { LOG_GCC(trans, LOGL_ERROR, "No memory for state machine.\n"); break; } /* Create cell structure. */ cell = talloc_zero(fi, struct vgcs_bss_cell); if (!cell) { LOG_GCC(trans, LOGL_ERROR, "No memory for BSS cell structure.\n"); osmo_fsm_inst_free(fi); break; } cell->fi = fi; fi->priv = cell; osmo_fsm_inst_update_id_f(cell->fi, "vgcs-cell-%d", c->cell_id); cell->trans_type = trans->type; cell->callref = trans->callref; cell->pc = b->pc; cell->cell_id = c->cell_id; cell->call_id = trans->call_id; /* Create ran connection. */ cell->conn = ran_conn_create_outgoing(rp); if (!cell->conn) { LOG_GCC(trans, LOGL_ERROR, "Failed to create RAN connection.\n"); osmo_fsm_inst_free(cell->fi); continue; } cell->conn->vgcs.cell = cell; /* Attach to cell list of BSS and MGW endpoint */ llist_add_tail(&cell->list_bss, &bss->cell_list); cell->bss = bss; llist_add_tail(&cell->list_mgw, &mgw->cell_list); cell->mgw = mgw; } /* No cell? */ if (llist_empty(&bss->cell_list)) { LOG_GCC(trans, LOGL_DEBUG, " -> No Cell in this BSS.\n"); osmo_fsm_inst_free(bss->fi); break; } /* Attach to transaction list */ llist_add_tail(&bss->list, &trans->gcc.bss_list); /* Trigger VGCS/VBS SETUP */ osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_SETUP, NULL); } /* No BSS? */ if (llist_empty(&trans->gcc.bss_list)) { /* Also destroy MGW, because this list is empty too! */ LOG_GCC(trans, LOGL_NOTICE, "No BSS found, please check your VTY configuration and add cells.\n"); goto err_mgw; } return 0; err_mgw: if (mgw) { if (mgw->mgw_ep) { /* This will also free FSM instance and vgcs_mgw_ep structure. */ osmo_fsm_inst_dispatch(mgw->fi, VGCS_MGW_EP_EV_CLEAR, NULL); return -EINVAL; } osmo_fsm_inst_free(mgw->fi); } return -EINVAL; } /* Send Assignment Request to the calling subscriber. * This is used to assign the subscriber from early assigned channel to the VGCS/VBS channel. */ static int gcc_assign(struct gsm_trans *trans) { struct ran_msg tx_ran_msg; struct gsm0808_channel_type channel_type; struct vgcs_bss *bss = NULL, *b; /* No assignment, because the calling subscriber is already assigned or there is no calling subscriber. */ if (!trans->msc_a) return 0; /* Check calling subscriber's MSC */ struct ran_conn *conn = msub_ran_conn(trans->msc_a->c.msub); if (!conn) { LOG_GCC(trans, LOGL_ERROR, "Calling subscriber has no ran_conn????\n"); return -EINVAL; } llist_for_each_entry(b, &trans->gcc.bss_list, list) { if (osmo_sccp_addr_ri_cmp(&conn->ran_peer->peer_addr, &b->conn->ran_peer->peer_addr)) continue; bss = b; break; } if (!bss) { LOG_GCC(trans, LOGL_ERROR, "Calling subscriber comes from BSC that has no VGCS call.\n"); return -EINVAL; } /* For now we support GSM/FR V1 only. This shall be supported by all MS. */ channel_type = (struct gsm0808_channel_type) { .ch_indctr = GSM0808_CHAN_SPEECH, .ch_rate_type = GSM0808_SPEECH_FULL_BM, .perm_spch_len = 1, .perm_spch[0] = GSM0808_PERM_FR1, }; /* Send assignment to VGCS channel */ tx_ran_msg = (struct ran_msg) { .msg_type = RAN_MSG_ASSIGNMENT_COMMAND, .assignment_command = { .channel_type = &channel_type, .callref_present = true, .callref = { .sf = (trans->type == TRANS_GCC), }, }, }; osmo_store32be_ext(trans->callref >> 3, &tx_ran_msg.assignment_command.callref.call_ref_hi, 3); tx_ran_msg.assignment_command.callref.call_ref_lo = trans->callref & 0x7; if (msc_a_ran_down(trans->msc_a, MSC_ROLE_I, &tx_ran_msg)) { LOG_GCC(trans, LOGL_ERROR, "Cannot send Assignment\n"); return -EIO; } /* Assign Talker to BSS of the calling subscriber. */ trans->gcc.uplink_bss = bss; return 0; } /* Send CONNECT to the calling subscriber. */ static void gcc_connect(struct gsm_trans *trans) { uint8_t pdisc = (trans->type == TRANS_GCC) ? GSM48_PDISC_GROUP_CC : GSM48_PDISC_BCAST_CC; int rc; /* Send CONNECT towards MS. */ rc = gsm44068_tx_connect(trans, pdisc | (trans->transaction_id << 4), trans->callref, 0, 0, 1, 0, 0, 0, 0); if (rc < 0) LOG_GCC(trans, LOGL_ERROR, "Failed to send CONNECT towards MS. Continue anyway.\n"); } /* Release dedicated (SDCCH) channel of calling subscriber after assigning to VGCS */ static void release_msc_a(struct gsm_trans *trans) { struct msc_a *msc_a = trans->msc_a; if (!msc_a) return; trans->msc_a = NULL; switch (trans->type) { case TRANS_GCC: msc_a_put(msc_a, MSC_A_USE_GCC); break; case TRANS_BCC: msc_a_put(msc_a, MSC_A_USE_BCC); break; default: break; } } /* Send TERMINATE to the calling/talking subscriber, then destroy transaction. */ static void gcc_terminate_and_destroy(struct gsm_trans *trans, enum osmo_gsm44068_cause cause) { uint8_t pdisc = (trans->type == TRANS_GCC) ? GSM48_PDISC_GROUP_CC : GSM48_PDISC_BCAST_CC; int rc; /* Send TERMINATION towards MS. */ rc = gsm44068_tx_termination(trans->msc_a, trans->gcc.uplink_bss, pdisc | (trans->transaction_id << 4), OSMO_GSM44068_MSGT_TERMINATION, cause, NULL, 0); if (rc < 0) LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION towards MS. Continue anyway.\n"); /* Destroy transaction, note that also _gsm44068_gcc_trans_free() will be called by trans_free(). * There the complete state machine is destroyed. */ trans->callref = 0; trans_free(trans); } /* Send TERMINATION REJECT to the calling/talking subscriber. */ static void gcc_termination_reject(struct gsm_trans *trans, enum osmo_gsm44068_cause cause) { uint8_t pdisc = (trans->type == TRANS_GCC) ? GSM48_PDISC_GROUP_CC : GSM48_PDISC_BCAST_CC; int rc; /* Send TERMINATION towards MS. */ rc = gsm44068_tx_termination(trans->msc_a, trans->gcc.uplink_bss, pdisc | (trans->transaction_id << 4), OSMO_GSM44068_MSGT_TERMINATION_REJECT, cause, NULL, 0); if (rc < 0) LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION REJECT towards MS.\n"); } /* Start inactivity timer. * This timer is used to terminate the call, if the radio connection to the caller gets lost. */ static void start_inactivity_timer(struct gsm_trans *trans) { if (trans->gcc.inactivity_to) { LOG_GCC(trans, LOGL_DEBUG, "Set inactivity timer to %d seconds.\n", trans->gcc.inactivity_to); osmo_timer_schedule(&trans->gcc.timer_inactivity, trans->gcc.inactivity_to, 0); } } static void stop_inactivity_timer(struct gsm_trans *trans) { if (osmo_timer_pending(&trans->gcc.timer_inactivity)) { LOG_GCC(trans, LOGL_DEBUG, "Stop pending inactivity timer.\n"); osmo_timer_del(&trans->gcc.timer_inactivity); } } static void inactivity_timer_cb(void *data) { struct gsm_trans *trans = data; osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_TIMEOUT, NULL); } /* Set the parameters of the talker. (downlink mute/unmute, uplink unmute, COMM=T, originator) */ static int set_parameter(struct gsm_trans *trans) { uint8_t pdisc = (trans->type == TRANS_GCC) ? GSM48_PDISC_GROUP_CC : GSM48_PDISC_BCAST_CC; int rc; rc = gsm44068_tx_set_parameter(trans, pdisc | (trans->transaction_id << 4), !trans->gcc.mute_talker, 1, 1, trans->gcc.uplink_originator); if (rc < 0) LOG_GCC(trans, LOGL_ERROR, "Failed to send SET PARAMETER towards MS.\n"); return rc; } /* Check in which cell the uplink is used and set "uplink_cell". */ static int set_uplink_cell(struct vgcs_bss *bss, struct gsm0808_cell_id *cell_id_ie, uint16_t cell_id) { struct vgcs_bss_cell *cell; if (cell_id_ie) { /* Get cell ID to determine talker channel. */ switch (cell_id_ie->id_discr) { case CELL_IDENT_CI: cell_id = cell_id_ie->id.ci; break; case CELL_IDENT_LAC_AND_CI: cell_id = cell_id_ie->id.lac_and_ci.ci; break; default: LOG_BSS(bss, LOGL_DEBUG, "Cannot idenitfy cell, please fix!\n"); return -EINVAL; } } /* Search for cell ID. */ bss->trans->gcc.uplink_cell = NULL; llist_for_each_entry(cell, &bss->cell_list, list_bss) { if (cell->cell_id == cell_id) { LOG_BSS(bss, LOGL_DEBUG, "Talker is talking on cell %d.\n", cell->cell_id); bss->trans->gcc.uplink_cell = cell; return 0; } } LOG_BSS(bss, LOGL_DEBUG, "Cell ID %d is not in list of current BSS, please fix!\n", cell_id); return -EINVAL; } /* Set the MGW conference mode. * All cells are listening to the conference. If there is a talker, this cell is also transmitting to the conference. */ static int set_mgw_conference(struct gsm_trans *trans) { struct vgcs_bss *bss; struct vgcs_bss_cell *cell; struct rtp_stream *rtps; int rc; /* All cells without talker are listening */ llist_for_each_entry(bss, &trans->gcc.bss_list, list) { llist_for_each_entry(cell, &bss->cell_list, list_bss) { if (!(rtps = cell->rtps)) continue; if (rtps->crcx_conn_mode != MGCP_CONN_SEND_ONLY) { LOG_CELL(cell, LOGL_DEBUG, "Setting cell %d into listening mode.\n", cell->cell_id); rtp_stream_set_mode(rtps, MGCP_CONN_SEND_ONLY); rc = rtp_stream_commit(rtps); if (rc < 0) LOG_CELL(cell, LOGL_ERROR, "Failed to commit parameters to RTP stream " "for cell %d.\n", cell->cell_id); } } } if (trans->gcc.uplink_cell && trans->gcc.uplink_cell->rtps) { cell = trans->gcc.uplink_cell; rtps = cell->rtps; LOG_CELL(cell, LOGL_DEBUG, "Setting cell %d into listening mode.\n", cell->cell_id); rtp_stream_set_mode(rtps, MGCP_CONN_CONFECHO); rc = rtp_stream_commit(rtps); if (rc < 0) LOG_CELL(cell, LOGL_ERROR, "Failed to commit parameters to RTP stream " "for cell %d.\n", cell->cell_id); } return 0; } static void _assign_complete(struct gsm_trans *trans, bool send_connect) { uint16_t cell_id; OSMO_ASSERT(trans->msc_a); /* Change state. */ osmo_fsm_inst_state_chg(trans->gcc.fi, VGCS_GCC_ST_N2_CALL_ACTIVE, 0, 0); /* Get cell ID. */ cell_id = trans->msc_a->via_cell.cell_identity; /* Releasing dedicated channel. */ release_msc_a(trans); /* Send CONNECT to the calling subscriber. */ if (send_connect) gcc_connect(trans); /* Set parameter. */ set_parameter(trans); /* Start inactivity timer, if uplink is free. */ if (!trans->gcc.uplink_busy) start_inactivity_timer(trans); /* Set cell of current talker. */ set_uplink_cell(trans->gcc.uplink_bss, NULL, cell_id); /* Set MGW conference. */ set_mgw_conference(trans); } #define CONNECT_OPTION false static void vgcs_gcc_fsm_n0_null(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_trans *trans = fi->priv; int rc; switch (event) { case VGCS_GCC_EV_NET_SETUP: /* Establish call towards all BSSs. */ LOG_GCC(trans, LOGL_DEBUG, "Setup by network, trying to establish cells.\n"); rc = gcc_establish_bss(trans); if (rc < 0) { LOG_GCC(trans, LOGL_NOTICE, "Failed to setup call to any cell.\n"); gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); break; } /* Keep state until established or released. */ break; case VGCS_GCC_EV_NET_TERM: LOG_GCC(trans, LOGL_DEBUG, "Termination by network, destroying call.\n"); /* Destroy group call in all cells. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); break; case VGCS_GCC_EV_USER_SETUP: LOG_GCC(trans, LOGL_DEBUG, "Setup by MS, trying to establish cells.\n"); /* Change state. */ osmo_fsm_inst_state_chg(fi, VGCS_GCC_ST_N1_CALL_INITIATED, 0, 0); /* Establish call towards all BSSs. */ rc = gcc_establish_bss(trans); if (rc < 0) { LOG_GCC(trans, LOGL_NOTICE, "Failed to setup call to any cell.\n"); gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); break; } if (CONNECT_OPTION) { /* Send CONNECT to the calling subscriber. */ gcc_connect(trans); /* Change state. */ osmo_fsm_inst_state_chg(fi, VGCS_GCC_ST_N3_CALL_EST_PROC, 0, 0); } break; case VGCS_GCC_EV_BSS_ESTABLISHED: LOG_GCC(trans, LOGL_DEBUG, "All cells establised, for a group call, sending CONNECT to caller.\n"); /* Change state. */ osmo_fsm_inst_state_chg(fi, VGCS_GCC_ST_N2_CALL_ACTIVE, 0, 0); /* Start inactivity timer, if uplink is free. */ if (!trans->gcc.uplink_busy) start_inactivity_timer(trans); break; case VGCS_GCC_EV_BSS_RELEASED: LOG_GCC(trans, LOGL_DEBUG, "All group call in all cells failed, destroying call.\n"); /* Send TERMINATE to the calling subscriber. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); break; default: OSMO_ASSERT(false); } } static void vgcs_gcc_fsm_n1_call_initiated(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_trans *trans = fi->priv; int rc; switch (event) { case VGCS_GCC_EV_NET_TERM: LOG_GCC(trans, LOGL_DEBUG, "Termination by network, destroying call.\n"); /* Destroy group call in all cells. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); break; case VGCS_GCC_EV_USER_TERM: LOG_GCC(trans, LOGL_DEBUG, "Termination by user, destroying call.\n"); /* Send TERMINATE to the calling subscriber and destroy group call in all cells. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); break; case VGCS_GCC_EV_BSS_ESTABLISHED: LOG_GCC(trans, LOGL_DEBUG, "All cells establised, for a group call, assign caller to VGCS.\n"); /* Send assignment to the calling subscriber. */ rc = gcc_assign(trans); if (rc < 0) { gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); break; } break; case VGCS_GCC_EV_BSS_ASSIGN_CPL: LOG_GCC(trans, LOGL_DEBUG, "Assignment complete, sending CONNECT to caller, releasing channel.\n"); /* Handle assignment complete */ _assign_complete(trans, true); break; case VGCS_GCC_EV_BSS_ASSIGN_FAIL: LOG_GCC(trans, LOGL_DEBUG, "Assignment failed, releasing call.\n"); /* Send TERMINATE to the calling subscriber. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); break; case VGCS_GCC_EV_BSS_RELEASED: LOG_GCC(trans, LOGL_DEBUG, "All group call in all cells failed, destroying call.\n"); /* Send TERMINATE to the calling subscriber. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); break; default: OSMO_ASSERT(false); } } static void vgcs_gcc_fsm_n2_call_active(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_trans *trans = fi->priv; switch (event) { case VGCS_GCC_EV_NET_TERM: LOG_GCC(trans, LOGL_DEBUG, "Termination by network, destroying call.\n"); /* Destroy group call in all cells. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); break; case VGCS_GCC_EV_USER_TERM: if (!trans->gcc.uplink_originator) { LOG_GCC(trans, LOGL_ERROR, "Termination by user, but it is not the originator.\n"); gcc_termination_reject(trans, OSMO_GSM44068_CAUSE_USER_NOT_ORIGINATOR); break; } LOG_GCC(trans, LOGL_DEBUG, "Termination by user, destroying call.\n"); /* Send TERMINATE to the calling subscriber and destroy group call in all cells. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); break; case VGCS_GCC_EV_BSS_RELEASED: LOG_GCC(trans, LOGL_DEBUG, "All group call in all cells failed, destroying call.\n"); /* Send TERMINATE to the calling subscriber. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); break; case VGCS_GCC_EV_TIMEOUT: LOG_GCC(trans, LOGL_DEBUG, "Termination by inactivity timer, destroying call.\n"); /* Destroy group call in all cells. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); break; default: OSMO_ASSERT(false); } } static void vgcs_gcc_fsm_n3_call_est_proc(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_trans *trans = fi->priv; int rc; switch (event) { case VGCS_GCC_EV_NET_TERM: LOG_GCC(trans, LOGL_DEBUG, "Termination by network, destroying call.\n"); /* Destroy group call in all cells. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); break; case VGCS_GCC_EV_USER_TERM: LOG_GCC(trans, LOGL_DEBUG, "Termination by user, destroying call.\n"); /* Send TERMINATE to the calling subscriber and destroy group call in all cells. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); break; case VGCS_GCC_EV_BSS_ESTABLISHED: LOG_GCC(trans, LOGL_DEBUG, "All cells establised, for a group call, assign caller to VGCS.\n"); /* Send assignment to the calling subscriber. */ rc = gcc_assign(trans); if (rc < 0) { gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); break; } break; case VGCS_GCC_EV_BSS_ASSIGN_CPL: LOG_GCC(trans, LOGL_DEBUG, "Assignment complete, sending CONNECT to caller, releasing channel.\n"); /* Handle assignment complete */ _assign_complete(trans, false); break; case VGCS_GCC_EV_BSS_ASSIGN_FAIL: LOG_GCC(trans, LOGL_DEBUG, "Assignment failed, releasing call.\n"); /* Send TERMINATE to the calling subscriber. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); break; case VGCS_GCC_EV_BSS_RELEASED: LOG_GCC(trans, LOGL_DEBUG, "All group call in all cells failed, destroying call.\n"); /* Send TERMINATE to the calling subscriber. */ gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); break; default: OSMO_ASSERT(false); } } static const struct osmo_fsm_state vgcs_gcc_fsm_states[] = { [VGCS_GCC_ST_N0_NULL] = { .name = "NULL (N0)", .in_event_mask = S(VGCS_GCC_EV_NET_SETUP) | S(VGCS_GCC_EV_NET_TERM) | S(VGCS_GCC_EV_USER_SETUP) | S(VGCS_GCC_EV_BSS_ESTABLISHED) | S(VGCS_GCC_EV_BSS_RELEASED), .out_state_mask = S(VGCS_GCC_ST_N1_CALL_INITIATED) | S(VGCS_GCC_ST_N2_CALL_ACTIVE), .action = vgcs_gcc_fsm_n0_null, }, [VGCS_GCC_ST_N1_CALL_INITIATED] = { .name = "CALL INITATED (N1)", .in_event_mask = S(VGCS_GCC_EV_NET_TERM) | S(VGCS_GCC_EV_USER_TERM) | S(VGCS_GCC_EV_BSS_ESTABLISHED) | S(VGCS_GCC_EV_BSS_ASSIGN_CPL) | S(VGCS_GCC_EV_BSS_ASSIGN_FAIL) | S(VGCS_GCC_EV_BSS_RELEASED), .out_state_mask = S(VGCS_GCC_ST_N0_NULL) | S(VGCS_GCC_ST_N2_CALL_ACTIVE) | S(VGCS_GCC_ST_N3_CALL_EST_PROC), .action = vgcs_gcc_fsm_n1_call_initiated, }, [VGCS_GCC_ST_N2_CALL_ACTIVE] = { .name = "CALL ACTIVE (N2)", .in_event_mask = S(VGCS_GCC_EV_NET_TERM) | S(VGCS_GCC_EV_USER_TERM) | S(VGCS_GCC_EV_BSS_RELEASED) | S(VGCS_GCC_EV_TIMEOUT), .out_state_mask = S(VGCS_GCC_ST_N0_NULL), .action = vgcs_gcc_fsm_n2_call_active, }, [VGCS_GCC_ST_N3_CALL_EST_PROC] = { .name = "CALL EST PROCEEDING (N3)", .in_event_mask = S(VGCS_GCC_EV_NET_TERM) | S(VGCS_GCC_EV_USER_TERM) | S(VGCS_GCC_EV_BSS_ESTABLISHED) | S(VGCS_GCC_EV_BSS_ASSIGN_CPL) | S(VGCS_GCC_EV_BSS_ASSIGN_FAIL) | S(VGCS_GCC_EV_BSS_RELEASED), .out_state_mask = S(VGCS_GCC_ST_N2_CALL_ACTIVE) | S(VGCS_GCC_ST_N0_NULL), .action = vgcs_gcc_fsm_n3_call_est_proc, }, // We don't need a state to wait for the group call to be terminated in all cells }; static struct osmo_fsm vgcs_bcc_fsm = { .name = "bcc", .states = vgcs_gcc_fsm_states, .num_states = ARRAY_SIZE(vgcs_gcc_fsm_states), .log_subsys = DBCC, .event_names = vgcs_gcc_fsm_event_names, }; static struct osmo_fsm vgcs_gcc_fsm = { .name = "gcc", .states = vgcs_gcc_fsm_states, .num_states = ARRAY_SIZE(vgcs_gcc_fsm_states), .log_subsys = DGCC, .event_names = vgcs_gcc_fsm_event_names, }; const char *vgcs_bcc_gcc_state_name(struct osmo_fsm_inst *fi) { return vgcs_gcc_fsm_states[fi->state].name; } static int update_uplink_state(struct vgcs_bss *bss, bool uplink_busy); /* Receive RR messages from calling subscriber, prior assignment to VGCS/VBS. */ int gsm44068_rcv_rr(struct msc_a *msc_a, struct msgb *msg) { struct gsm_trans *trans = NULL; struct gsm48_hdr *gh; uint8_t msg_type; gh = msgb_l3(msg); msg_type = gsm48_hdr_msg_type(gh); /* Find transaction. */ trans = trans_find_by_type(msc_a, TRANS_GCC); if (!trans) trans = trans_find_by_type(msc_a, TRANS_BCC); if (!trans) { LOG_GCC(trans, LOGL_ERROR, "No VGCS/VBS transaction.\n"); return -EINVAL; } /* In case the phone releases uplink prior being assigned to a VGCS */ if (msg_type == GSM48_MT_RR_UPLINK_RELEASE) { struct vgcs_bss *bss; LOG_GCC(trans, LOGL_INFO, "Received UPLINK RELEASE on initial channel.\n"); /* Clear the busy flag and unblock all cells. */ trans->gcc.uplink_bss = NULL; trans->gcc.uplink_cell = NULL; trans->gcc.uplink_busy = false; llist_for_each_entry(bss, &trans->gcc.bss_list, list) { /* Update uplink state. */ update_uplink_state(bss, trans->gcc.uplink_busy); } /* Start inactivity timer. */ start_inactivity_timer(bss->trans); /* Next, the MS will switch to the VGCS as listener. Nothing else to do here. */ } return 0; } /* Allocation of transaction for group call */ static struct gsm_trans *trans_alloc_vgcs(struct gsm_network *net, struct vlr_subscr *vsub, enum trans_type trans_type, uint8_t transaction_id, uint32_t callref, struct gcr *gcr, bool uplink_busy) { struct gsm_trans *trans; trans = trans_alloc(net, vsub, trans_type, transaction_id, callref); if (!trans) { LOG_GCC(trans, LOGL_ERROR, "No memory for trans.\n"); return NULL; } /* The uplink is busy when the call is started until the calling subscriber releases. */ trans->gcc.uplink_busy = uplink_busy; trans->gcc.uplink_originator = true; INIT_LLIST_HEAD(&trans->gcc.bss_list); trans->gcc.inactivity_to = gcr->timeout; trans->gcc.mute_talker = gcr->mute_talker; trans->gcc.timer_inactivity.data = trans; trans->gcc.timer_inactivity.cb = inactivity_timer_cb; trans->gcc.fi = osmo_fsm_inst_alloc((trans_type == TRANS_GCC) ? &vgcs_gcc_fsm : &vgcs_bcc_fsm, trans, trans, LOGL_DEBUG, NULL); if (!trans->gcc.fi) { LOG_GCC(trans, LOGL_ERROR, "No memory for state machine.\n"); trans_free(trans); return NULL; } return trans; } /* Create transaction from incoming voice group/broadcast call. */ static struct gsm_trans *trans_create_bcc_gcc(struct msc_a *msc_a, enum trans_type trans_type, uint8_t transaction_id, uint8_t pdisc, uint8_t msg_type, uint32_t callref) { struct gsm_network *net; struct vlr_subscr *vsub; struct gsm_trans *trans = NULL; struct gcr *gcr; int rc; if (!msc_a) { LOG_GCC(trans, LOGL_ERROR, "Invalid conn: no msc_a\n"); return NULL; } net = msc_a_net(msc_a); vsub = msc_a_vsub(msc_a); if (!vsub) { LOG_GCC(trans, LOGL_ERROR, "Invalid conn: no subscriber\n"); return NULL; } /* An earlier CM Service Request for this CC message now has concluded */ if (!osmo_use_count_by(&msc_a->use_count, (trans_type == TRANS_GCC) ? MSC_A_USE_CM_SERVICE_GCC : MSC_A_USE_CM_SERVICE_BCC)) LOG_MSC_A(msc_a, LOGL_ERROR, "Creating new %s transaction without prior CM Service Request.\n", get_value_string(trans_type_names, trans_type)); else msc_a_put(msc_a, (trans_type == TRANS_GCC) ? MSC_A_USE_CM_SERVICE_GCC : MSC_A_USE_CM_SERVICE_BCC); /* A transaction must be created with a SETUP message. */ if (msg_type != OSMO_GSM44068_MSGT_IMMEDIATE_SETUP && msg_type != OSMO_GSM44068_MSGT_SETUP && msg_type != OSMO_GSM44068_MSGT_IMMEDIATE_SETUP_2) { LOG_GCC(trans, LOGL_ERROR, "No transaction and message is not a SETUP.\n"); return NULL; } /* Check if callref already exists. */ trans = trans_find_by_callref(net, trans_type, callref); if (trans) { LOG_GCC(trans, LOGL_INFO, "Call to existing %s with callref %s, rejecting!\n", trans_type_name(trans_type), gsm44068_group_id_string(callref)); rc = gsm44068_tx_termination(msc_a, NULL, pdisc | (transaction_id << 4), OSMO_GSM44068_MSGT_TERMINATION, OSMO_GSM44068_CAUSE_BUSY, NULL, 0); if (rc < 0) LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION towards MS.\n"); return 0; } /* Check GCR for Group ID. */ gcr = gcr_by_callref(net, trans_type, callref); if (!gcr) { LOG_GCC(trans, LOGL_INFO, "No Group configured for %s callref %s, rejecting!\n", trans_type_name(trans_type), gsm44068_group_id_string(callref)); // FIXME: Better cause value for a group that does not exist ? rc = gsm44068_tx_termination(msc_a, NULL, pdisc | (transaction_id << 4), OSMO_GSM44068_MSGT_TERMINATION, OSMO_GSM44068_CAUSE_REQUESTED_SERVICE_NOT_SUB, NULL, 0); if (rc < 0) LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION towards MS.\n"); return 0; } /* Create transaction, uplink is busy. */ trans = trans_alloc_vgcs(net, vsub, trans_type, transaction_id, callref, gcr, true); if (!trans) { rc = gsm44068_tx_termination(msc_a, NULL, pdisc | (transaction_id << 4), OSMO_GSM44068_MSGT_TERMINATION, OSMO_GSM44068_CAUSE_NETWORK_FAILURE, NULL, 0); if (rc < 0) LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION towards MS.\n"); return NULL; } if (osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_TRANSACTION_ACCEPTED, trans)) { LOG_MSC_A(msc_a, LOGL_ERROR, "Not allowed to accept %s transaction.\n", get_value_string(trans_type_names, trans_type)); gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); return NULL; } /* Assign transaction */ msc_a_get(msc_a, (trans_type == TRANS_GCC) ? MSC_A_USE_GCC : MSC_A_USE_BCC); trans->msc_a = msc_a; trans->dlci = 0; /* main DCCH */ return trans; } /* Receive GCC/BCC messages from calling subscriber, depending on the PDISC used. */ int gsm44068_rcv_bcc_gcc(struct msc_a *msc_a, struct gsm_trans *trans, struct msgb *msg) { struct gsm48_hdr *gh = msgb_l3(msg); uint8_t msg_type = gsm48_hdr_msg_type(gh); uint8_t pdisc = gsm48_hdr_pdisc(gh); uint8_t transaction_id = gsm48_hdr_trans_id_flip_ti(gh); enum trans_type trans_type = (pdisc == GSM48_PDISC_GROUP_CC) ? TRANS_GCC : TRANS_BCC; uint8_t key_seq; bool talker_prio_requested; bool with_talker_prio; uint8_t talker_prio; struct gsm48_classmark2 cm2; struct osmo_mobile_identity mi; uint32_t callref; bool with_prio; uint8_t prio; char user_user[64] = ""; uint8_t cause; uint8_t diag[256]; uint8_t diag_len; bool with_call_state; enum osmo_gsm44068_call_state call_state; bool with_state_attrs; uint8_t da, ua, comm, oi; int rc = 0; /* Parse messages. */ switch (msg_type) { case OSMO_GSM44068_MSGT_SETUP: rc = gsm44068_rx_setup(msg, &talker_prio_requested, &talker_prio, &callref, &with_prio, &prio, user_user); break; case OSMO_GSM44068_MSGT_IMMEDIATE_SETUP: case OSMO_GSM44068_MSGT_IMMEDIATE_SETUP_2: rc = gsm44068_rx_immediate_setup(msg, &talker_prio, &key_seq, &cm2, &mi, &callref, &with_prio, &prio, user_user); break; case OSMO_GSM44068_MSGT_STATUS: rc = gsm44068_rx_status(msg, &cause, diag, &diag_len, &with_call_state, &call_state, &with_state_attrs, &da, &ua, &comm, &oi); break; case OSMO_GSM44068_MSGT_TERMINATION_REQUEST: rc = gsm44068_rx_termination_req(msg, &callref, &with_prio, &prio, &with_talker_prio, &talker_prio); break; default: LOG_GCC(trans, LOGL_ERROR, "Invalid message type: 0x%02x\n", msg_type); return -EINVAL; } if (rc < 0) return rc; /* Find transaction, if called from msc_a. */ if (!trans) trans = trans_find_by_id(msc_a, trans_type, transaction_id); /* Create transaction for SETUP message. */ if (!trans) { trans = trans_create_bcc_gcc(msc_a, trans_type, transaction_id, pdisc, msg_type, callref); if (!trans) return -EINVAL; } else { /* A phone may not call while a VGCS is already active */ if (msg_type == OSMO_GSM44068_MSGT_IMMEDIATE_SETUP || msg_type == OSMO_GSM44068_MSGT_SETUP || msg_type == OSMO_GSM44068_MSGT_IMMEDIATE_SETUP_2) { LOG_GCC(trans, LOGL_ERROR, "Received SETUP while call is already set up, rejecting.\n"); rc = gsm44068_tx_termination(msc_a, NULL, pdisc | (transaction_id << 4), OSMO_GSM44068_MSGT_TERMINATION, OSMO_GSM44068_CAUSE_NETWORK_FAILURE, NULL, 0); if (rc < 0) LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION towards MS.\n"); return -EINVAL; } } /* Handle received GCC messages (trigger state machine). */ switch (msg_type) { case OSMO_GSM44068_MSGT_IMMEDIATE_SETUP: case OSMO_GSM44068_MSGT_SETUP: case OSMO_GSM44068_MSGT_IMMEDIATE_SETUP_2: LOG_GCC(trans, LOGL_INFO, "Received SETUP.\n"); osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_USER_SETUP, NULL); break; case OSMO_GSM44068_MSGT_STATUS: LOG_GCC(trans, LOGL_NOTICE, "Received STATUS with cause %d (%s).\n", cause, get_value_string(osmo_gsm44068_cause_names, cause)); if (diag_len) LOG_GCC(trans, LOGL_NOTICE, " -> diagnostics: %s\n", osmo_hexdump(diag, diag_len)); if (with_call_state) LOG_GCC(trans, LOGL_NOTICE, " -> call state %s\n", get_value_string(osmo_gsm44068_call_state_names, call_state)); break; case OSMO_GSM44068_MSGT_TERMINATION_REQUEST: LOG_GCC(trans, LOGL_INFO, "Received TERMINATRION REQUEST.\n"); if (callref != trans->callref) { LOG_GCC(trans, LOGL_NOTICE, "Received callref 0x%x does not match!\n", callref); break; } osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_USER_TERM, NULL); break; } return 0; } static void bss_clear(struct vgcs_bss *bss, uint8_t cause, bool notify_trans); /* Call Control Specific transaction release. * gets called by trans_free, DO NOT CALL YOURSELF! */ void gsm44068_bcc_gcc_trans_free(struct gsm_trans *trans) { struct vgcs_bss *bss, *bss2; /* Free FSM. */ if (trans->gcc.fi) { osmo_fsm_inst_state_chg(trans->gcc.fi, VGCS_GCC_ST_N0_NULL, 0, 0); osmo_fsm_inst_term(trans->gcc.fi, OSMO_FSM_TERM_REGULAR, NULL); } /* Remove relations to cells. * We must loop safe, because bss_clear() will detach every call control instance from list. */ llist_for_each_entry_safe(bss, bss2, &trans->gcc.bss_list, list) osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_CLEAR, NULL); /* Stop inactivity timer. */ stop_inactivity_timer(trans); } /* Create a new call from VTY command. */ const char *vgcs_vty_initiate(struct gsm_network *gsmnet, struct gcr *gcr) { enum trans_type trans_type; uint32_t callref; struct gsm_trans *trans; /* Get callref from stored suffix. Caller cannot choose a prefix. */ trans_type = gcr->trans_type; callref = atoi(gcr->group_id); /* Check if callref already exists. */ trans = trans_find_by_callref(gsmnet, trans_type, callref); if (trans) { LOG_GCC(trans, LOGL_INFO, "Call to existing %s with callref %s, rejecting!\n", trans_type_name(trans_type), gsm44068_group_id_string(callref)); return "Call already exists."; } /* Create transaction, uplink is free. */ trans = trans_alloc_vgcs(gsmnet, NULL, trans_type, 0, callref, gcr, false); if (!trans) { LOG_GCC(trans, LOGL_ERROR, "No memory for trans.\n"); return "Failed to create call."; } LOG_GCC(trans, LOGL_INFO, "VTY initiates call.\n"); osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_NET_SETUP, NULL); return NULL; } /* Destroy a call from VTY command. */ const char *vgcs_vty_terminate(struct gsm_network *gsmnet, struct gcr *gcr) { enum trans_type trans_type; uint32_t callref; struct gsm_trans *trans; /* Get callref from stored suffix. Caller cannot choose a prefix. */ trans_type = gcr->trans_type; callref = atoi(gcr->group_id); /* Check if callref exists. */ trans = trans_find_by_callref(gsmnet, trans_type, callref); if (!trans) return "Call does not exist."; LOG_GCC(trans, LOGL_INFO, "VTY terminates call.\n"); osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_NET_TERM, NULL); return NULL; } /* * BSS state machine - handles all BSS "call control" instances */ static const struct value_string vgcs_bss_fsm_event_names[] = { OSMO_VALUE_STRING(VGCS_BSS_EV_SETUP), OSMO_VALUE_STRING(VGCS_BSS_EV_SETUP_ACK), OSMO_VALUE_STRING(VGCS_BSS_EV_SETUP_REFUSE), OSMO_VALUE_STRING(VGCS_BSS_EV_ACTIVE_OR_FAIL), OSMO_VALUE_STRING(VGCS_BSS_EV_UL_REQUEST), OSMO_VALUE_STRING(VGCS_BSS_EV_UL_REQUEST_CNF), OSMO_VALUE_STRING(VGCS_BSS_EV_UL_APP_DATA), OSMO_VALUE_STRING(VGCS_BSS_EV_BSS_DTAP), OSMO_VALUE_STRING(VGCS_BSS_EV_UL_RELEASE), OSMO_VALUE_STRING(VGCS_BSS_EV_CLEAR), OSMO_VALUE_STRING(VGCS_BSS_EV_CLOSE), OSMO_VALUE_STRING(VGCS_BSS_EV_RELEASED), { } }; /* Blocks or unblocks uplinks of a BSS. */ static int update_uplink_state(struct vgcs_bss *bss, bool uplink_busy) { struct ran_msg ran_msg; int rc; if (uplink_busy) { /* Send UPLINK SEIZED COMMAND to BSS. */ LOG_BSS(bss, LOGL_DEBUG, "Sending (VGCS) UPLINK SEIZED COMMAND towards BSS.\n"); ran_msg = (struct ran_msg){ .msg_type = RAN_MSG_UPLINK_SEIZED_CMD, .uplink_seized_cmd = { .cause = GSM0808_CAUSE_CALL_CONTROL, }, }; } else { /* Send UPLINK RELEASE COMMAND to BSS. */ LOG_BSS(bss, LOGL_DEBUG, "Sending (VGCS) UPLINK RELEASE COMMAND towards BSS.\n"); ran_msg = (struct ran_msg){ .msg_type = RAN_MSG_UPLINK_RELEASE_CMD, .uplink_release_cmd = { .cause = GSM0808_CAUSE_CALL_CONTROL, }, }; } rc = ran_encode_and_send(bss->fi, &ran_msg, bss->conn, false); return rc; } /* Clear the connection towards BSS. * The instance is removed soon, so it is detached from transaction and cells. */ static void bss_clear(struct vgcs_bss *bss, uint8_t cause, bool notify_trans) { struct ran_msg ran_msg; struct gsm_trans *trans = bss->trans; struct vgcs_bss_cell *cell, *cell2; /* Must detach us from transaction. */ if (bss->trans) { /* Remove pointer to talking BSS and cell. */ if (bss == bss->trans->gcc.uplink_bss) { bss->trans->gcc.uplink_bss = NULL; bss->trans->gcc.uplink_cell = NULL; } llist_del(&bss->list); bss->trans = NULL; } /* Change state. */ osmo_fsm_inst_state_chg(bss->fi, VGCS_BSS_ST_RELEASE, 0, 0); /* Send Clear Command to BSS. */ ran_msg = (struct ran_msg){ .msg_type = RAN_MSG_CLEAR_COMMAND, .clear_command = { .gsm0808_cause = cause, }, }; if (bss->conn) { LOG_BSS(bss, LOGL_DEBUG, "Sending CLEAR COMMAND for call controling channel.\n"); ran_encode_and_send(bss->fi, &ran_msg, bss->conn, false); } /* Trigger clear of all cells. Be safe, because the process will remove cells from list. */ llist_for_each_entry_safe(cell, cell2, &bss->cell_list, list_bss) osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_CLEAR, NULL); /* Detach us from all BSS, if still linked */ llist_for_each_entry_safe(cell, cell2, &bss->cell_list, list_bss) { llist_del(&cell->list_bss); cell->bss = NULL; } /* If all BS are gone, notify calling subscriber process. */ if (notify_trans && trans && llist_empty(&trans->gcc.bss_list)) { LOG_BSS(bss, LOGL_DEBUG, "Notify calling user process, that all BSSs are cleared.\n"); osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_BSS_RELEASED, NULL); } } /* When finally the BSS connection is released. (CLEAR COMPLETE response) * The instance is removed, so it is detached from transaction and cells, if not already. */ static void bss_destroy(struct vgcs_bss *bss) { struct vgcs_bss_cell *cell, *cell2; LOG_BSS(bss, LOGL_DEBUG, "Removing BSS call controling instance.\n"); /* Must detach us from transaction, if not already. */ if (bss->trans) { /* Remove pointer to talking BSS and cell. */ if (bss == bss->trans->gcc.uplink_bss) { bss->trans->gcc.uplink_bss = NULL; bss->trans->gcc.uplink_cell = NULL; } llist_del(&bss->list); bss->trans = NULL; } /* Detach us from RAN connection. */ if (bss->conn) { if (bss->conn->vgcs.bss == bss) bss->conn->vgcs.bss = NULL; if (bss->conn->vgcs.cell == bss) bss->conn->vgcs.cell = NULL; ran_conn_close(bss->conn); bss->conn = NULL; } /* Detach us from all BSS, if still linked */ llist_for_each_entry_safe(cell, cell2, &bss->cell_list, list_bss) { llist_del(&cell->list_bss); cell->bss = NULL; } /* Free FSM. (should be allocated) */ osmo_fsm_inst_state_chg(bss->fi, VGCS_BSS_ST_NULL, 0, 0); osmo_fsm_inst_term(bss->fi, OSMO_FSM_TERM_REGULAR, NULL); } /* Get identity of talker. * This is required to detect if the talker is the calling subscriber. */ static int talker_identity(struct vgcs_bss *bss, uint8_t *l3, int l3_len) { struct osmo_mobile_identity mi; int rc; rc = osmo_mobile_identity_decode_from_l3_buf(&mi, l3, l3_len, false); if (rc < 0) { LOG_BSS(bss, LOGL_DEBUG, "Talker's Identity cannot be decoded.\n"); return rc; } switch (mi.type) { case GSM_MI_TYPE_IMSI: if (!bss->trans->vsub) break; LOG_BSS(bss, LOGL_DEBUG, "Talker's sends IMSI %s, originator has IMSI %s.\n", mi.imsi, bss->trans->vsub->imsi); if (!strcmp(mi.imsi, bss->trans->vsub->imsi)) return 1; break; case GSM_MI_TYPE_TMSI: if (!bss->trans->vsub) break; LOG_BSS(bss, LOGL_DEBUG, "Talker's sends TMSI 0x%08x, originator has TMSI 0x%08x.\n", mi.tmsi, bss->trans->vsub->tmsi); if (mi.tmsi == bss->trans->vsub->tmsi) return 1; break; default: LOG_BSS(bss, LOGL_DEBUG, "Talker's Identity is not IMSI nor TMSI.\n"); return -EINVAL; } return 0; } static void vgcs_bss_fsm_null(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct vgcs_bss *bss = fi->priv; struct ran_msg ran_msg; switch (event) { case VGCS_BSS_EV_SETUP: /* Change state. */ osmo_fsm_inst_state_chg(fi, VGCS_BSS_ST_SETUP, 0, 0); /* Send VGCS/VBS SETUP to BSS. */ LOG_BSS(bss, LOGL_DEBUG, "Sending VGCS/VBS SETUP towards BSS.\n"); ran_msg = (struct ran_msg){ .msg_type = RAN_MSG_VGCS_VBS_SETUP, .vgcs_vbs_setup = { .callref = { .sf = (bss->trans->type == TRANS_GCC), }, .vgcs_feature_flags_present = true, }, }; osmo_store32be_ext(bss->callref >> 3, &ran_msg.vgcs_vbs_setup.callref.call_ref_hi, 3); ran_msg.vgcs_vbs_setup.callref.call_ref_lo = bss->callref & 0x7; /* First message, so we must set "initial" to "true". */ ran_encode_and_send(fi, &ran_msg, bss->conn, true); break; case VGCS_BSS_EV_CLEAR: /* The calling user process requested clearing of VGCS/VBS call. */ LOG_BSS(bss, LOGL_DEBUG, "Received clearing from calling user process.\n"); bss_clear(bss, GSM0808_CAUSE_CALL_CONTROL, false); break; default: OSMO_ASSERT(false); } } static void vgcs_bss_fsm_setup(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct vgcs_bss *bss = fi->priv; struct vgcs_bss_cell *cell, *cell2; switch (event) { case VGCS_BSS_EV_SETUP_ACK: /* Receive VGCS/VBS SETUP ACK from BSS. */ LOG_BSS(bss, LOGL_DEBUG, "Received VGCS/VBS SETUP ACK from BSS.\n"); /* Send current uplink state to this BSS. */ if (bss->trans) update_uplink_state(bss, bss->trans->gcc.uplink_busy); /* Change state. */ osmo_fsm_inst_state_chg(fi, VGCS_BSS_ST_ASSIGNMENT, 0, 0); /* Trigger VGCS/VBS ASSIGNMENT */ llist_for_each_entry_safe(cell, cell2, &bss->cell_list, list_bss) osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_ASSIGN, NULL); /* If all failed, clear call. */ if (llist_empty(&bss->cell_list)) { LOG_BSS(bss, LOGL_NOTICE, "All VGCS/VBS assignments failed.\n"); bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); break; } break; case VGCS_BSS_EV_SETUP_REFUSE: /* Received VGCS/VBS SETUP REFUSE from BSS. */ LOG_BSS(bss, LOGL_NOTICE, "Received VGCS/VBS SETUP REFUSE from BSS.\n"); bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); break; case VGCS_BSS_EV_CLEAR: /* The calling user process requested clearing of VGCS/VBS call. */ LOG_BSS(bss, LOGL_DEBUG, "Received clearing from calling user process.\n"); bss_clear(bss, GSM0808_CAUSE_CALL_CONTROL, false); break; case VGCS_BSS_EV_CLOSE: /* The SCCP connection from the MSC has been closed. */ LOG_BSS(bss, LOGL_NOTICE, "Received SCCP connecting closing from MSC.\n"); if (bss->conn) { bss->conn->vgcs.bss = NULL; bss->conn = NULL; } bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); break; default: OSMO_ASSERT(false); } } static void vgcs_bss_fsm_assignment(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct vgcs_bss *bss = fi->priv; struct vgcs_bss_cell *c; bool assigned; switch (event) { case VGCS_BSS_EV_ACTIVE_OR_FAIL: /* If all gone, clear call. */ if (llist_empty(&bss->cell_list)) { LOG_BSS(bss, LOGL_NOTICE, "All VGCS/VBS assignments failed.\n"); bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); break; } /* Is there a response for all cells? * This means that all the channels have a positive response * There is no channel with negative response, because a * negative response will remove the channel. */ assigned = true; llist_for_each_entry(c, &bss->cell_list, list_bss) { if (!c->assigned) assigned = false; } if (!assigned) break; LOG_BSS(bss, LOGL_DEBUG, "All VGCS/VBS assignments have responded.\n"); /* Change state. */ osmo_fsm_inst_state_chg(fi, VGCS_BSS_ST_ACTIVE, 0, 0); /* Notify calling subscriber process. */ LOG_BSS(bss, LOGL_DEBUG, "Notify calling user process, that all BSSs are connected.\n"); if (bss->trans) osmo_fsm_inst_dispatch(bss->trans->gcc.fi, VGCS_GCC_EV_BSS_ESTABLISHED, NULL); break; case VGCS_BSS_EV_CLEAR: /* The calling user process requested clearing of VGCS/VBS call. */ LOG_BSS(bss, LOGL_DEBUG, "Received clearing from calling user process.\n"); bss_clear(bss, GSM0808_CAUSE_CALL_CONTROL, false); break; case VGCS_BSS_EV_CLOSE: /* The SCCP connection from the MSC has been closed. */ LOG_BSS(bss, LOGL_NOTICE, "Received SCCP connecting closing from MSC.\n"); if (bss->conn) { bss->conn->vgcs.bss = NULL; bss->conn = NULL; } bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); break; default: OSMO_ASSERT(false); } } static void vgcs_bss_fsm_active(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct vgcs_bss *bss = fi->priv, *other; struct ran_msg *rx_ran_msg = data; struct ran_msg tx_ran_msg; int rc; switch (event) { case VGCS_BSS_EV_UL_REQUEST: LOG_BSS(bss, LOGL_DEBUG, "Listener changed to talker.\n"); if (!bss->trans) break; /* Someone is talking. Check if there is no other uplink already busy. * This should not happen, since all other cells are blocked (SEIZED) as soon as the uplink was * requested. This may happen due to a race condition, where the uplink was requested before the * UPLINK SEIZED COMMAND has been received by BSS. */ if (bss->trans->gcc.uplink_busy) { /* Send UPLINK REJECT COMMAND to BSS. */ LOG_BSS(bss, LOGL_DEBUG, "Sending (VGCS) UPLINK REJECT COMMAND towards BSS.\n"); tx_ran_msg = (struct ran_msg){ .msg_type = RAN_MSG_UPLINK_REJECT_CMD, .uplink_reject_cmd = { .cause = GSM0808_CAUSE_CALL_CONTROL, }, }; ran_encode_and_send(fi, &tx_ran_msg, bss->conn, false); break; } /* Send UPLINK REQUEST ACKNOWLEDGE to BSS. */ LOG_BSS(bss, LOGL_DEBUG, "Sending (VGCS) UPLINK REQUEST ACKNOWLEDGE towards BSS.\n"); tx_ran_msg = (struct ran_msg){ .msg_type = RAN_MSG_UPLINK_REQUEST_ACK, }; ran_encode_and_send(fi, &tx_ran_msg, bss->conn, false); /* Set the busy flag and block all other cells. */ bss->trans->gcc.uplink_bss = bss; bss->trans->gcc.uplink_busy = true; bss->trans->gcc.uplink_originator = false; llist_for_each_entry(other, &bss->trans->gcc.bss_list, list) { if (other == bss) continue; /* Update uplink state. */ update_uplink_state(bss, bss->trans->gcc.uplink_busy); } /* Stop inactivity timer. */ stop_inactivity_timer(bss->trans); break; case VGCS_BSS_EV_UL_REQUEST_CNF: LOG_BSS(bss, LOGL_DEBUG, "Talker established uplink.\n"); if (!bss->trans) break; if (!bss->trans->gcc.uplink_busy || bss->trans->gcc.uplink_bss != bss) { LOG_BSS(bss, LOGL_ERROR, "Got UL REQUEST CNF, but we did not granted uplink.\n"); break; } /* Determine if talker is the originator of the call. */ rc = talker_identity(bss, rx_ran_msg->uplink_request_cnf.l3.l3, rx_ran_msg->uplink_request_cnf.l3.l3_len); if (rc > 0) { bss->trans->gcc.uplink_originator = true; LOG_BSS(bss, LOGL_DEBUG, "Talker is the originator of the call.\n"); } /* Set parameter. */ set_parameter(bss->trans); /* Set cell of current talker. */ set_uplink_cell(bss, &rx_ran_msg->uplink_request_cnf.cell_identifier, 0); /* Set MGW conference. */ set_mgw_conference(bss->trans); break; case VGCS_BSS_EV_UL_APP_DATA: LOG_BSS(bss, LOGL_DEBUG, "Talker sends application data on uplink.\n"); if (!bss->trans) break; if (!bss->trans->gcc.uplink_busy || bss->trans->gcc.uplink_bss != bss) { LOG_BSS(bss, LOGL_ERROR, "Got UP APP DATA, but we did not granted uplink.\n"); break; } // FIXME: Use L3 info and feed to app. break; case VGCS_BSS_EV_BSS_DTAP: LOG_BSS(bss, LOGL_DEBUG, "Talker sends DTAP message.\n"); if (!bss->trans) break; if (!bss->trans->gcc.uplink_busy || bss->trans->gcc.uplink_bss != bss) { LOG_BSS(bss, LOGL_ERROR, "Got DTAP from BSS, but we did not granted uplink.\n"); break; } gsm44068_rcv_bcc_gcc(NULL, bss->trans, rx_ran_msg->dtap); break; case VGCS_BSS_EV_UL_RELEASE: LOG_BSS(bss, LOGL_DEBUG, "Talker released uplink.\n"); if (!bss->trans) break; if (bss->trans->type == TRANS_BCC) { LOG_BSS(bss, LOGL_DEBUG, "This is a broadcast call, terminating call.\n"); gcc_terminate_and_destroy(bss->trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); break; } if (!bss->trans->gcc.uplink_busy) { LOG_BSS(bss, LOGL_NOTICE, "Got uplink release, but no uplink busy.\n"); break; } /* Talker release the uplink. Ignore, if not from the current talking cell. */ if (bss->trans->gcc.uplink_bss != bss) { LOG_BSS(bss, LOGL_NOTICE, "Got uplink release, but uplink busy in other cell.\n"); break; } /* Clear the busy flag and unblock all other cells. */ bss->trans->gcc.uplink_bss = NULL; bss->trans->gcc.uplink_cell = NULL; bss->trans->gcc.uplink_busy = false; llist_for_each_entry(other, &bss->trans->gcc.bss_list, list) { if (other == bss) continue; /* Update uplink state. */ if (bss->trans) update_uplink_state(bss, bss->trans->gcc.uplink_busy); } /* Set MGW conference. */ set_mgw_conference(bss->trans); /* Start inactivity timer. */ start_inactivity_timer(bss->trans); break; case VGCS_BSS_EV_CLEAR: /* The calling user process requested clearing of VGCS/VBS call. */ LOG_BSS(bss, LOGL_DEBUG, "Received clearing from calling user process.\n"); bss_clear(bss, GSM0808_CAUSE_CALL_CONTROL, false); break; case VGCS_BSS_EV_CLOSE: /* The SCCP connection from the MSC has been closed. */ LOG_BSS(bss, LOGL_NOTICE, "Received SCCP connecting closing from MSC.\n"); if (bss->conn) { bss->conn->vgcs.bss = NULL; bss->conn = NULL; } bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); break; default: OSMO_ASSERT(false); } } static void vgcs_bss_fsm_release(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct vgcs_bss *bss = fi->priv; switch (event) { case VGCS_BSS_EV_CLOSE: /* The SCCP connection from the MSC has been closed while waitring fro CLEAR COMPLETE. */ LOG_BSS(bss, LOGL_NOTICE, "Received SCCP closing collision.\n"); bss_destroy(bss); break; case VGCS_BSS_EV_RELEASED: LOG_BSS(bss, LOGL_DEBUG, "Received CLEAR COMPLETE from BSS, we are done!\n"); bss_destroy(bss); break; default: OSMO_ASSERT(false); } } static const struct osmo_fsm_state vgcs_bss_fsm_states[] = { [VGCS_BSS_ST_NULL] = { .name = "NULL", .in_event_mask = S(VGCS_BSS_EV_SETUP) | S(VGCS_BSS_EV_CLEAR), .out_state_mask = S(VGCS_BSS_ST_SETUP), .action = vgcs_bss_fsm_null, }, [VGCS_BSS_ST_SETUP] = { .name = "SETUP sent", .in_event_mask = S(VGCS_BSS_EV_SETUP_ACK) | S(VGCS_BSS_EV_SETUP_REFUSE) | S(VGCS_BSS_EV_CLEAR) | S(VGCS_BSS_EV_CLOSE), .out_state_mask = S(VGCS_BSS_ST_ASSIGNMENT) | S(VGCS_BSS_ST_RELEASE), .action = vgcs_bss_fsm_setup, }, [VGCS_BSS_ST_ASSIGNMENT] = { .name = "ASSIGNMENT Sent", .in_event_mask = S(VGCS_BSS_EV_ACTIVE_OR_FAIL) | S(VGCS_BSS_EV_CLEAR) | S(VGCS_BSS_EV_CLOSE), .out_state_mask = S(VGCS_BSS_ST_ACTIVE) | S(VGCS_BSS_ST_RELEASE), .action = vgcs_bss_fsm_assignment, }, [VGCS_BSS_ST_ACTIVE] = { .name = "VGCS/VBS Active", .in_event_mask = S(VGCS_BSS_EV_UL_REQUEST) | S(VGCS_BSS_EV_UL_REQUEST_CNF) | S(VGCS_BSS_EV_UL_APP_DATA) | S(VGCS_BSS_EV_BSS_DTAP) | S(VGCS_BSS_EV_UL_RELEASE) | S(VGCS_BSS_EV_CLEAR) | S(VGCS_BSS_EV_CLOSE), .out_state_mask = S(VGCS_BSS_ST_RELEASE), .action = vgcs_bss_fsm_active, }, [VGCS_BSS_ST_RELEASE] = { .name = "Releasing VGCS/VBS control", .in_event_mask = S(VGCS_BSS_EV_CLEAR) | S(VGCS_BSS_EV_RELEASED), .out_state_mask = S(VGCS_BSS_ST_NULL), .action = vgcs_bss_fsm_release, }, }; static struct osmo_fsm vgcs_bss_fsm = { .name = "vgcs_bss", .states = vgcs_bss_fsm_states, .num_states = ARRAY_SIZE(vgcs_bss_fsm_states), .log_subsys = DASCI, .event_names = vgcs_bss_fsm_event_names, }; /* The BSS accepts VGCS/VBS and sends us supported features. */ void vgcs_vbs_setup_ack(struct vgcs_bss *bss, const struct ran_msg *ran_msg) { if (!bss->trans) return; osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_SETUP_ACK, (void *)ran_msg); } /* The BSS refuses VGCS/VBS. */ void vgcs_vbs_setup_refuse(struct vgcs_bss *bss, const struct ran_msg *ran_msg) { if (!bss->trans) return; osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_SETUP_REFUSE, (void *)ran_msg); } /* The BSS needs more time for VGCS/VBS channel assignment. */ void vgcs_vbs_queuing_ind(struct vgcs_bss_cell *cell) { if (!cell->bss) return; } /* A mobile station requests the uplink on a VGCS channel. */ void vgcs_uplink_request(struct vgcs_bss *bss, const struct ran_msg *ran_msg) { if (!bss->trans) return; osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_UL_REQUEST, (void *)ran_msg); } /* The uplink on a VGCS channel has been established. */ void vgcs_uplink_request_cnf(struct vgcs_bss *bss, const struct ran_msg *ran_msg) { if (!bss->trans) return; osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_UL_REQUEST_CNF, (void *)ran_msg); } /* Application data received on the uplink of a VGCS channel. */ void vgcs_app_data(struct vgcs_bss *bss, const struct ran_msg *ran_msg) { if (!bss->trans) return; osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_UL_APP_DATA, (void *)ran_msg); } /* Application data received on the uplink of a VGCS channel. */ void vgcs_bss_dtap(struct vgcs_bss *bss, const struct ran_msg *ran_msg) { if (!bss->trans) return; osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_BSS_DTAP, (void *)ran_msg); } /* A mobile station releases the uplink on a VGCS channel. */ void vgcs_uplink_release_ind(struct vgcs_bss *bss, const struct ran_msg *ran_msg) { if (!bss->trans) return; osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_UL_RELEASE, (void *)ran_msg); } /* The BSS gives cell status about VGCS/VBS channel. */ void vgcs_vbs_assign_status(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg) { if (!cell->bss) return; } void vgcs_vbs_caller_assign_cpl(struct gsm_trans *trans) { osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_BSS_ASSIGN_CPL, NULL); } void vgcs_vbs_caller_assign_fail(struct gsm_trans *trans) { osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_BSS_ASSIGN_FAIL, NULL); } /* BSS indicated that the channel has been released. */ void vgcs_vbs_clear_req(struct vgcs_bss *bss, const struct ran_msg *ran_msg) { osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_CLOSE, (void *)ran_msg); } /* BSS indicated that the channel has been released. */ void vgcs_vbs_clear_cpl(struct vgcs_bss *bss, const struct ran_msg *ran_msg) { osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_RELEASED, (void *)ran_msg); } /* * Cell resource state machine - handles all "resource control" instances */ static const struct value_string vgcs_cell_fsm_event_names[] = { OSMO_VALUE_STRING(VGCS_CELL_EV_RTP_STREAM_GONE), OSMO_VALUE_STRING(VGCS_CELL_EV_RTP_STREAM_ADDR_AVAILABLE), OSMO_VALUE_STRING(VGCS_CELL_EV_RTP_STREAM_ESTABLISHED), OSMO_VALUE_STRING(VGCS_CELL_EV_ASSIGN), OSMO_VALUE_STRING(VGCS_CELL_EV_ASSIGN_RES), OSMO_VALUE_STRING(VGCS_CELL_EV_ASSIGN_FAIL), OSMO_VALUE_STRING(VGCS_CELL_EV_CLEAR), OSMO_VALUE_STRING(VGCS_CELL_EV_CLOSE), OSMO_VALUE_STRING(VGCS_CELL_EV_RELEASED), { } }; static void cell_destroy(struct vgcs_bss_cell *cell); /* Clear the connection towards BSS. * Relations to the BSS and transaction is removed. */ static void cell_clear(struct vgcs_bss_cell *cell, uint8_t cause) { struct ran_msg ran_msg; /* Must detach us from BSS. */ if (cell->bss) { /* Remove pointer to talking channel. */ if (cell->bss->trans && cell->bss->trans->gcc.uplink_cell == cell) cell->bss->trans->gcc.uplink_cell = NULL; llist_del(&cell->list_bss); cell->bss = NULL; } /* Change state. */ if (cell->fi->state != VGCS_CELL_ST_RELEASE) osmo_fsm_inst_state_chg(cell->fi, VGCS_CELL_ST_RELEASE, 0, 0); /* If there is no event to wait for, we can just destroy. */ if (!cell->conn && !cell->rtps) { cell_destroy(cell); return; } /* Send Clear Command to BSS. */ if (cell->conn) { ran_msg = (struct ran_msg){ .msg_type = RAN_MSG_CLEAR_COMMAND, .clear_command = { .gsm0808_cause = cause, }, }; LOG_CELL(cell, LOGL_DEBUG, "Sending CLEAR COMMAND for call controling channel.\n"); ran_encode_and_send(cell->fi, &ran_msg, cell->conn, false); } /* Clear RTP stream. This may trigger VGCS_CELL_EV_RTP_STREAM_GONE within this release function. */ if (cell->rtps) rtp_stream_release(cell->rtps); } /* When finally the BSS connection is released. (CLEAR COMPLETE response) * Relations to the BSS and transaction is removed, if not already. */ static void cell_destroy(struct vgcs_bss_cell *cell) { struct vgcs_mgw_ep *mgw; /* close RAN conn */ if (cell->conn) { cell->conn->vgcs.cell = NULL; ran_conn_close(cell->conn); cell->conn = NULL; } /* Detach from BSS now. Check, to prevent race condition. */ if (cell->bss) { /* Remove pointer to talking channel. */ if (cell->bss->trans && cell->bss->trans->gcc.uplink_cell == cell) cell->bss->trans->gcc.uplink_cell = NULL; llist_del(&cell->list_bss); cell->bss = NULL; } /* Detach from MGW now. Check, to prevent race condition. */ if (cell->mgw) { mgw = cell->mgw; llist_del(&cell->list_mgw); cell->mgw = NULL; /* Destroy MGW endpoint, if list is empty. */ if (llist_empty(&mgw->cell_list)) osmo_fsm_inst_dispatch(mgw->fi, VGCS_MGW_EP_EV_CLEAR, NULL); } LOG_CELL(cell, LOGL_DEBUG, "Detroy connection to cell.\n"); /* Free FSM. (should be allocated) */ osmo_fsm_inst_state_chg(cell->fi, VGCS_CELL_ST_NULL, 0, 0); osmo_fsm_inst_term(cell->fi, OSMO_FSM_TERM_REGULAR, NULL); } static void vgcs_cell_fsm_null(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct vgcs_bss_cell *cell = fi->priv; const struct codec_mapping *cm; int rc; switch (event) { case VGCS_CELL_EV_ASSIGN: LOG_CELL(cell, LOGL_DEBUG, "Received assignment from BSS controling process.\n"); /* Allocate rtps stream. */ cell->rtps = rtp_stream_alloc(cell->fi, VGCS_CELL_EV_RTP_STREAM_GONE, VGCS_CELL_EV_RTP_STREAM_ADDR_AVAILABLE, VGCS_CELL_EV_RTP_STREAM_ESTABLISHED, RTP_TO_RAN, cell->call_id, NULL); if (!cell->rtps) { LOG_CELL(cell, LOGL_DEBUG, "Failed to allocate RTP stream, cannot continue.\n"); cell_destroy(cell); break; } /* Hard coded codec: GSM V1 */ cm = codec_mapping_by_gsm0808_speech_codec_type(GSM0808_SCT_FR1); if (!cm) { LOG_CELL(cell, LOGL_DEBUG, "Selected codec not supported, cannot continue.\n"); cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); break; } rtp_stream_set_one_codec(cell->rtps, &cm->sdp); /* Set initial mode. */ rtp_stream_set_mode(cell->rtps, MGCP_CONN_RECV_ONLY); /* Commit RTP stream. */ if (!cell->bss || !cell->bss->trans) { LOG_CELL(cell, LOGL_DEBUG, "No BSS/transaction, cannot continue.\n"); cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); break; } if (!cell->mgw || !cell->mgw->mgw_ep) { LOG_CELL(cell, LOGL_DEBUG, "No MGW endpoint, cannot continue.\n"); cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); break; } rc = rtp_stream_ensure_ci(cell->rtps, cell->mgw->mgw_ep); if (rc < 0) { LOG_CELL(cell, LOGL_DEBUG, "Failed to trigger RTP stream CI.\n"); cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); break; } /* Change state. */ osmo_fsm_inst_state_chg(fi, VGCS_CELL_ST_ASSIGNMENT, 0, 0); break; case VGCS_CELL_EV_CLEAR: /* The calling user process requested clearing of VGCS/VBS call. */ LOG_CELL(cell, LOGL_DEBUG, "Received clearing from BSS controling process.\n"); cell_clear(cell, GSM0808_CAUSE_CALL_CONTROL); break; default: OSMO_ASSERT(false); } } static void vgcs_cell_fsm_assignment(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct vgcs_bss_cell *cell = fi->priv; struct ran_msg *rx_ran_msg = data; struct ran_msg tx_ran_msg; struct osmo_sockaddr_str ss; const struct codec_mapping *cm; struct vgcs_bss *bss; int rc; switch (event) { case VGCS_CELL_EV_RTP_STREAM_GONE: /* The RTP stream failed. */ LOG_CELL(cell, LOGL_ERROR, "RTP stream of MGW failed.\n"); cell->rtps = NULL; goto channel_fail; break; case VGCS_CELL_EV_RTP_STREAM_ADDR_AVAILABLE: /* The RTP stream sends its peer. */ if (!osmo_sockaddr_str_is_nonzero(&cell->rtps->local)) { LOG_CELL(cell, LOGL_ERROR, "Invalid RTP address received from MGW: " OSMO_SOCKADDR_STR_FMT "\n", OSMO_SOCKADDR_STR_FMT_ARGS(&cell->rtps->local)); goto channel_fail; } LOG_CELL(cell, LOGL_DEBUG, "MGW endpoint's RTP address available for the CI %s: " OSMO_SOCKADDR_STR_FMT " (osmux=%s:%d)\n", rtp_direction_name(cell->rtps->dir), OSMO_SOCKADDR_STR_FMT_ARGS(&cell->rtps->local), cell->rtps->use_osmux ? "yes" : "no", cell->rtps->local_osmux_cid); /* Send VGCS/VBS ASSIGNMENT REQUEST to BSS */ LOG_CELL(cell, LOGL_DEBUG, "Sending VGCS/VBS ASSIGNMENT REQUEST towards BSS.\n"); tx_ran_msg = (struct ran_msg) { .msg_type = RAN_MSG_VGCS_VBS_ASSIGN_REQ, .vgcs_vbs_assign_req = { /* For now we support GSM/FR V1 only. This shall be supported by all MS. */ .channel_type = { .ch_indctr = GSM0808_CHAN_SPEECH, .ch_rate_type = GSM0808_SPEECH_FULL_BM, .perm_spch_len = 1, .perm_spch[0] = GSM0808_PERM_FR1, }, /* For now we want a channel without any delay. */ .ass_req = GSM0808_ASRQ_IMMEDIATE, .callref = { .sf = (cell->trans_type == TRANS_GCC), }, /* We need to identify the cell only. */ .cell_identifier = { .id_discr = CELL_IDENT_CI, .id.ci = cell->cell_id, }, .aoip_transport_layer_present = true, .call_id_present = true, .call_id = cell->call_id, .codec_list_present = true, .codec_list_msc_preferred = { .len = 1, .codec[0] = { .fi = 1, .type = GSM0808_SCT_FR1, .cfg = 0, }, }, }, }; osmo_store32be_ext(cell->callref >> 3, &tx_ran_msg.vgcs_vbs_assign_req.callref.call_ref_hi, 3); tx_ran_msg.vgcs_vbs_assign_req.callref.call_ref_lo = cell->callref & 0x7; osmo_sockaddr_str_to_sockaddr(&cell->rtps->local, &tx_ran_msg.vgcs_vbs_assign_req.aoip_transport_layer); /* First message, so we must set "initial" to "true". */ ran_encode_and_send(fi, &tx_ran_msg, cell->conn, true); break; case VGCS_CELL_EV_RTP_STREAM_ESTABLISHED: /* The RTP stream established. */ LOG_CELL(cell, LOGL_DEBUG, "RTP stream is established.\n"); break; case VGCS_CELL_EV_ASSIGN_RES: /* Receive VGCS/VBS ASSIGNMENT RESULT from BSS. */ LOG_CELL(cell, LOGL_DEBUG, "Received VGCS/VBS ASSIGNMENT RESULT from BSS.\n"); cell->assigned = true; if (!rx_ran_msg->vgcs_vbs_assign_res.aoip_transport_layer_present && !rx_ran_msg->vgcs_vbs_assign_res.codec_present && !rx_ran_msg->vgcs_vbs_assign_res.call_id_present) { LOG_CELL(cell, LOGL_ERROR, "Mandatory IEs missing.\n"); goto channel_fail; } /* Send remote peer to RTP stream. */ if (osmo_sockaddr_str_from_sockaddr(&ss, &rx_ran_msg->vgcs_vbs_assign_res.aoip_transport_layer)) { LOG_CELL(cell, LOGL_ERROR, "Cannot RTP-CONNECT, invalid RTP IP:port in incoming MNCC " "message\n"); goto channel_fail; } rtp_stream_set_remote_addr(cell->rtps, &ss); /* Send remote codec to RTP stream. */ cm = codec_mapping_by_gsm0808_speech_codec_type(rx_ran_msg->vgcs_vbs_assign_res.codec_msc_chosen.type); if (!cm) { LOG_CELL(cell, LOGL_ERROR, "Chosen codec by BSC is not supported by MSC.\n"); goto channel_fail; } rtp_stream_set_one_codec(cell->rtps, &cm->sdp); /* Set listening mode. */ rtp_stream_set_mode(cell->rtps, MGCP_CONN_SEND_ONLY); /* Commit RTP stream. */ rc = rtp_stream_commit(cell->rtps); if (rc < 0) { LOG_CELL(cell, LOGL_ERROR, "Failed to commit parameters to RTP stream.\n"); goto channel_fail; } /* Change state. */ osmo_fsm_inst_state_chg(fi, VGCS_CELL_ST_ACTIVE, 0, 0); /* Notify BSS FSM about channel activation. */ if (cell->bss) osmo_fsm_inst_dispatch(cell->bss->fi, VGCS_BSS_EV_ACTIVE_OR_FAIL, NULL); break; case VGCS_CELL_EV_ASSIGN_FAIL: /* Received VGCS/VBS ASSIGNMENT FAILURE from BSS. */ LOG_CELL(cell, LOGL_NOTICE, "Received VGCS/VBS ASSIGNMENT FAILURE from BSS.\n"); channel_fail: bss = cell->bss; cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); /* Notify BSS FSM about channel failure. */ if (bss) osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_ACTIVE_OR_FAIL, NULL); break; case VGCS_CELL_EV_CLEAR: /* The calling user process requested clearing of VGCS/VBS call. */ LOG_CELL(cell, LOGL_DEBUG, "Received clearing from BSS controling process.\n"); cell_clear(cell, GSM0808_CAUSE_CALL_CONTROL); break; case VGCS_CELL_EV_CLOSE: /* The SCCP connection from the MSC has been closed. */ LOG_CELL(cell, LOGL_NOTICE, "Received SCCP connecting closing from MSC.\n"); if (cell->conn) { cell->conn->vgcs.bss = NULL; cell->conn = NULL; } cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); break; default: OSMO_ASSERT(false); } } static void vgcs_cell_fsm_active(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct vgcs_bss_cell *cell = fi->priv; switch (event) { case VGCS_CELL_EV_RTP_STREAM_GONE: /* The RTP stream failed. */ LOG_CELL(cell, LOGL_ERROR, "RTP stream of MGW failed.\n"); cell->rtps = NULL; cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); break; case VGCS_CELL_EV_RTP_STREAM_ESTABLISHED: /* The RTP stream established. */ LOG_CELL(cell, LOGL_DEBUG, "RTP stream is established.\n"); break; case VGCS_CELL_EV_CLEAR: /* The calling user process requested clearing of VGCS/VBS call. */ LOG_CELL(cell, LOGL_DEBUG, "Received clearing from BSS controling process.\n"); cell_clear(cell, GSM0808_CAUSE_CALL_CONTROL); break; case VGCS_CELL_EV_CLOSE: /* The SCCP connection from the MSC has been closed. */ LOG_CELL(cell, LOGL_NOTICE, "Received SCCP connecting closing from MSC.\n"); if (cell->conn) { cell->conn->vgcs.bss = NULL; cell->conn = NULL; } cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); break; default: OSMO_ASSERT(false); } } static void vgcs_cell_fsm_release(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct vgcs_bss_cell *cell = fi->priv; switch (event) { case VGCS_CELL_EV_RTP_STREAM_GONE: /* The RTP stream gone. */ LOG_CELL(cell, LOGL_ERROR, "RTP stream gone.\n"); cell->rtps = NULL; /* Wait for RAN conn. */ if (cell->conn) break; cell_destroy(cell); break; case VGCS_CELL_EV_CLEAR: case VGCS_CELL_EV_RELEASED: if (event == VGCS_CELL_EV_CLEAR) { /* The SCCP connection from the MSC has been closed while waiting for CLEAR COMPLETE. */ LOG_CELL(cell, LOGL_NOTICE, "Received SCCP closing collision.\n"); } else LOG_CELL(cell, LOGL_DEBUG, "Received CLEAR COMPLETE from BSS, we are done!\n"); /* Wait for RTP stream. */ if (cell->rtps) { /* close RAN conn */ if (cell->conn) { cell->conn->vgcs.cell = NULL; ran_conn_close(cell->conn); cell->conn = NULL; } break; } cell_destroy(cell); break; default: OSMO_ASSERT(false); } } static const struct osmo_fsm_state vgcs_cell_fsm_states[] = { [VGCS_CELL_ST_NULL] = { .name = "NULL", .in_event_mask = S(VGCS_CELL_EV_ASSIGN) | S(VGCS_CELL_EV_CLEAR), .out_state_mask = S(VGCS_CELL_ST_ASSIGNMENT), .action = vgcs_cell_fsm_null, }, [VGCS_CELL_ST_ASSIGNMENT] = { .name = "ASSIGNMENT Sent", .in_event_mask = S(VGCS_CELL_EV_RTP_STREAM_GONE) | S(VGCS_CELL_EV_RTP_STREAM_ADDR_AVAILABLE) | S(VGCS_CELL_EV_RTP_STREAM_ESTABLISHED) | S(VGCS_CELL_EV_ASSIGN_RES) | S(VGCS_CELL_EV_ASSIGN_FAIL) | S(VGCS_CELL_EV_CLEAR) | S(VGCS_CELL_EV_CLOSE), .out_state_mask = S(VGCS_CELL_ST_ACTIVE) | S(VGCS_CELL_ST_RELEASE), .action = vgcs_cell_fsm_assignment, }, [VGCS_CELL_ST_ACTIVE] = { .name = "VGCS/VBS channel active", .in_event_mask = S(VGCS_CELL_EV_RTP_STREAM_GONE) | S(VGCS_CELL_EV_RTP_STREAM_ESTABLISHED) | S(VGCS_CELL_EV_CLEAR) | S(VGCS_CELL_EV_CLOSE), .out_state_mask = S(VGCS_CELL_ST_RELEASE), .action = vgcs_cell_fsm_active, }, [VGCS_CELL_ST_RELEASE] = { .name = "Releasing VGCS/VBS channel", .in_event_mask = S(VGCS_CELL_EV_RTP_STREAM_GONE) | S(VGCS_CELL_EV_CLEAR) | S(VGCS_CELL_EV_RELEASED), .out_state_mask = S(VGCS_CELL_ST_NULL), .action = vgcs_cell_fsm_release, }, }; static struct osmo_fsm vgcs_cell_fsm = { .name = "vgcs_cell", .states = vgcs_cell_fsm_states, .num_states = ARRAY_SIZE(vgcs_cell_fsm_states), .log_subsys = DASCI, .event_names = vgcs_cell_fsm_event_names, }; /* The BSS accepts VGCS/VBS channel assignment. */ void vgcs_vbs_assign_result(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg) { osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_ASSIGN_RES, (void *)ran_msg); } /* The BSS refuses VGCS/VBS channel assignment. */ void vgcs_vbs_assign_fail(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg) { osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_ASSIGN_FAIL, (void *)ran_msg); } /* BSS indicated that the channel has been released. */ void vgcs_vbs_clear_req_channel(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg) { LOG_CELL(cell, LOGL_DEBUG, "Received CLEAR REQUEST for resource controling channel from BSS.\n"); osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_CLOSE, (void *)ran_msg); } /* BSS confirms the release of channel. */ void vgcs_vbs_clear_cpl_channel(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg) { LOG_CELL(cell, LOGL_DEBUG, "Received CLEAR COMPLETE for resource controling channel from BSS.\n"); osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_RELEASED, (void *)ran_msg); } /* * MGW endpoint FSM */ static const struct value_string vgcs_mgw_ep_fsm_event_names[] = { OSMO_VALUE_STRING(VGCS_MGW_EP_EV_FREE), OSMO_VALUE_STRING(VGCS_MGW_EP_EV_CLEAR), { } }; static void vgcs_mgw_ep_fsm_active(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct vgcs_mgw_ep *mgw = fi->priv; struct vgcs_bss_cell *cell, *cell2; struct mgcp_client *mgcp_client; switch (event) { case VGCS_MGW_EP_EV_FREE: LOGP(DASCI, LOGL_DEBUG, "MGW connection closed, removing all cell instances.\n"); llist_for_each_entry_safe(cell, cell2, &mgw->cell_list, list_mgw) { if (cell->rtps) cell->rtps->ci = NULL; llist_del(&cell->list_mgw); cell->mgw = NULL; } /* Put MGCP client back into MGW pool. */ mgcp_client = osmo_mgcpc_ep_client(mgw->mgw_ep); mgcp_client_pool_put(mgcp_client); /* Destroy this instance. */ osmo_fsm_inst_term_children(fi, OSMO_FSM_TERM_PARENT, NULL); osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); break; case VGCS_MGW_EP_EV_CLEAR: if (!llist_empty(&mgw->cell_list)) break; LOGP(DASCI, LOGL_DEBUG, "Cell list of MGW instance is now empty, dropping.\n"); /* Destroy this instance. */ osmo_fsm_inst_term_children(fi, OSMO_FSM_TERM_PARENT, NULL); osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); break; default: OSMO_ASSERT(false); } } static const struct osmo_fsm_state vgcs_mgw_ep_fsm_states[] = { [VGCS_MGW_EP_ST_NULL] = { .name = "NULL", .out_state_mask = S(VGCS_MGW_EP_ST_ACTIVE), }, [VGCS_MGW_EP_ST_ACTIVE] = { .name = "MGW endpoint allocated", .in_event_mask = S(VGCS_MGW_EP_EV_FREE) | S(VGCS_MGW_EP_EV_CLEAR), .out_state_mask = S(VGCS_MGW_EP_ST_NULL), .action = vgcs_mgw_ep_fsm_active, }, }; static struct osmo_fsm vgcs_mgw_ep_fsm = { .name = "vgcs_mgw_ep", .states = vgcs_mgw_ep_fsm_states, .num_states = ARRAY_SIZE(vgcs_mgw_ep_fsm_states), .log_subsys = DASCI, .event_names = vgcs_mgw_ep_fsm_event_names, };