/* Code to manage a subscriber's MSC-A role */ /* * (C) 2019 by sysmocom - s.f.m.c. GmbH * All Rights Reserved * * SPDX-License-Identifier: AGPL-3.0+ * * Author: Neels Hofmeyr * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define MSC_A_USE_WAIT_CLEAR_COMPLETE "wait-Clear-Complete" static struct osmo_fsm msc_a_fsm; static const struct osmo_tdef_state_timeout msc_a_fsm_timeouts[32] = { [MSC_A_ST_VALIDATE_L3] = { .T = -1 }, [MSC_A_ST_AUTH_CIPH] = { .keep_timer = true }, [MSC_A_ST_WAIT_CLASSMARK_UPDATE] = { .keep_timer = true }, [MSC_A_ST_AUTHENTICATED] = { .keep_timer = true }, [MSC_A_ST_RELEASING] = { .T = -2 }, [MSC_A_ST_RELEASED] = { .T = -2 }, }; /* Transition to a state, using the T timer defined in msc_a_fsm_timeouts. * The actual timeout value is in turn obtained from network->T_defs. * Assumes local variable fi exists. */ #define msc_a_state_chg_always(msc_a, state) \ osmo_tdef_fsm_inst_state_chg((msc_a)->c.fi, state, msc_a_fsm_timeouts, (msc_a)->c.ran->tdefs, 5) /* Same as msc_a_state_chg_always() but ignore if the msc_a already is in the target state. */ #define msc_a_state_chg(msc_a, STATE) do { \ if ((msc_a)->c.fi->state != STATE) \ msc_a_state_chg_always(msc_a, STATE); \ } while(0) struct gsm_network *msc_a_net(const struct msc_a *msc_a) { return msub_net(msc_a->c.msub); } struct vlr_subscr *msc_a_vsub(const struct msc_a *msc_a) { if (!msc_a) return NULL; return msub_vsub(msc_a->c.msub); } struct msc_i *msc_a_msc_i(const struct msc_a *msc_a) { if (!msc_a) return NULL; return msub_msc_i(msc_a->c.msub); } struct msc_t *msc_a_msc_t(const struct msc_a *msc_a) { if (!msc_a) return NULL; return msub_msc_t(msc_a->c.msub); } struct msc_a *msc_a_fi_priv(struct osmo_fsm_inst *fi) { OSMO_ASSERT(fi); OSMO_ASSERT(fi->fsm == &msc_a_fsm); OSMO_ASSERT(fi->priv); return fi->priv; } bool msc_a_is_ciphering_to_be_attempted(const struct msc_a *msc_a) { struct gsm_network *net = msc_a_net(msc_a); bool is_utran = (msc_a->c.ran->type == OSMO_RAT_UTRAN_IU); if (is_utran) return net->uea_encryption_mask > (1 << OSMO_UTRAN_UEA0); else return net->a5_encryption_mask > 0x1; } bool msc_a_is_ciphering_required(const struct msc_a *msc_a) { struct gsm_network *net = msc_a_net(msc_a); bool is_utran = (msc_a->c.ran->type == OSMO_RAT_UTRAN_IU); if (is_utran) return net->uea_encryption_mask && ((net->uea_encryption_mask & (1 << OSMO_UTRAN_UEA0)) == 0); else return net->a5_encryption_mask && ((net->a5_encryption_mask & 0x1) == 0); } static void update_counters(struct osmo_fsm_inst *fi, bool conn_accepted) { struct msc_a *msc_a = fi->priv; struct gsm_network *net = msc_a_net(msc_a); switch (msc_a->complete_layer3_type) { case COMPLETE_LAYER3_LU: rate_ctr_inc(rate_ctr_group_get_ctr(net->msc_ctrs, conn_accepted ? MSC_CTR_LOC_UPDATE_COMPLETED : MSC_CTR_LOC_UPDATE_FAILED)); break; case COMPLETE_LAYER3_CM_SERVICE_REQ: rate_ctr_inc(rate_ctr_group_get_ctr(net->msc_ctrs, conn_accepted ? MSC_CTR_CM_SERVICE_REQUEST_ACCEPTED : MSC_CTR_CM_SERVICE_REQUEST_REJECTED)); break; case COMPLETE_LAYER3_PAGING_RESP: rate_ctr_inc(rate_ctr_group_get_ctr(net->msc_ctrs, conn_accepted ? MSC_CTR_PAGING_RESP_ACCEPTED : MSC_CTR_PAGING_RESP_REJECTED)); break; case COMPLETE_LAYER3_CM_RE_ESTABLISH_REQ: rate_ctr_inc(rate_ctr_group_get_ctr(net->msc_ctrs, conn_accepted ? MSC_CTR_CM_RE_ESTABLISH_REQ_ACCEPTED : MSC_CTR_CM_RE_ESTABLISH_REQ_REJECTED)); break; default: break; } } static void lu_delay_timer_cb(void *data) { struct msc_a *msc_a = (struct msc_a *)data; msc_a_put(msc_a, MSC_A_USE_LOCATION_UPDATING); } static void msc_a_put_lu_deferred(struct msc_a *msc_a) { unsigned long Tval; /* The idea behind timer X36 is to allow re-using the radio channel that was used for * Location Updating to deliver MT SMS over GSUP. This is achieved by delaying * release of a BSSAP/RANAP connection and thus delaying the release of the radio * channel. The delay can be configured separately for GERAN and UTRAN. */ switch (msc_a->c.ran->type) { case OSMO_RAT_GERAN_A: Tval = osmo_tdef_get(msc_tdefs_geran, -36, OSMO_TDEF_MS, 0); break; case OSMO_RAT_UTRAN_IU: Tval = osmo_tdef_get(msc_tdefs_utran, -36, OSMO_TDEF_MS, 0); break; default: Tval = 0; break; } if (Tval == 0) { /* no delay, put LU token immediately */ msc_a_put(msc_a, MSC_A_USE_LOCATION_UPDATING); return; } LOG_MSC_A(msc_a, LOGL_INFO, "Keeping LU token for +%lu ms\n", Tval); osmo_timer_schedule(&msc_a->lu_delay_timer, Tval / 1000, /* seconds */ Tval % 1000 * 1000); /* microseconds */ } static void evaluate_acceptance_outcome(struct osmo_fsm_inst *fi, bool conn_accepted) { struct msc_a *msc_a = fi->priv; struct vlr_subscr *vsub = msc_a_vsub(msc_a); update_counters(fi, conn_accepted); if (conn_accepted) { /* Record the Cell ID seen in Complete Layer 3 Information in the VLR, so that it also shows in vty * 'show' output. */ vsub->cgi = msc_a->via_cell; } /* Trigger transactions that we paged for */ if (msc_a->complete_layer3_type == COMPLETE_LAYER3_PAGING_RESP) { if (conn_accepted) paging_response(msc_a); else paging_expired(vsub); } if (conn_accepted) osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_ATTACHED, msc_a_vsub(msc_a)); if (msc_a->complete_layer3_type == COMPLETE_LAYER3_LU) msc_a_put_lu_deferred(msc_a); if (conn_accepted && msc_a->complete_layer3_type == COMPLETE_LAYER3_CM_RE_ESTABLISH_REQ) { /* Trigger new Assignment to recommence the voice call. A little dance here because normally we verify * that no CC trans is already active. */ struct gsm_trans *cc_trans = msc_a->cc.active_trans; msc_a->cc.active_trans = NULL; osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_TRANSACTION_ACCEPTED, cc_trans); msc_a_try_call_assignment(cc_trans); } } bool msc_a_is_accepted(const struct msc_a *msc_a) { if (!msc_a || !msc_a->c.fi) return false; return msc_a->c.fi->state == MSC_A_ST_AUTHENTICATED || msc_a->c.fi->state == MSC_A_ST_COMMUNICATING; } bool msc_a_in_release(struct msc_a *msc_a) { if (!msc_a) return true; if (msc_a->c.fi->state == MSC_A_ST_RELEASING) return true; if (msc_a->c.fi->state == MSC_A_ST_RELEASED) return true; return false; } static int msc_a_ran_dec(struct msc_a *msc_a, const struct an_apdu *an_apdu, enum msc_role from_role) { int rc; struct msc_a_ran_dec_data d = { .from_role = from_role, .an_apdu = an_apdu, }; msc_a_get(msc_a, __func__); rc = msc_role_ran_decode(msc_a->c.fi, an_apdu, msc_a_ran_decode_cb, &d); msc_a_put(msc_a, __func__); return rc; }; static void msc_a_fsm_validate_l3(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct msc_a *msc_a = fi->priv; const struct an_apdu *an_apdu; switch (event) { case MSC_A_EV_FROM_I_COMPLETE_LAYER_3: case MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST: case MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST: an_apdu = data; msc_a_ran_dec(msc_a, an_apdu, MSC_ROLE_I); return; case MSC_A_EV_COMPLETE_LAYER_3_OK: msc_a_state_chg(msc_a, MSC_A_ST_AUTH_CIPH); return; case MSC_A_EV_MO_CLOSE: case MSC_A_EV_CN_CLOSE: evaluate_acceptance_outcome(fi, false); /* fall through */ case MSC_A_EV_UNUSED: msc_a_state_chg(msc_a, MSC_A_ST_RELEASING); return; default: OSMO_ASSERT(false); } } /* Figure out whether to first send a Classmark Request to the MS to figure out algorithm support. */ static bool msc_a_need_classmark_for_ciphering(struct msc_a *msc_a) { struct gsm_network *net = msc_a_net(msc_a); struct vlr_subscr *vsub = msc_a_vsub(msc_a); int i = 0; bool request_classmark = false; /* Only on GERAN-A do we ever need Classmark Information for Ciphering. */ if (msc_a->c.ran->type != OSMO_RAT_GERAN_A) return false; for (i = 0; i < 8; i++) { int supported; /* A5/n permitted by osmo-msc.cfg? */ if (!(net->a5_encryption_mask & (1 << i))) continue; /* A5/n supported by MS? */ supported = osmo_gsm48_classmark_supports_a5(&vsub->classmark, i); if (supported < 0) { LOG_MSC_A(msc_a, LOGL_DEBUG, "For A5/%d, we still need Classmark %d\n", i, -supported); request_classmark = true; } } return request_classmark; } static int msc_a_ran_enc_ciphering(struct msc_a *msc_a, bool umts_aka, bool retrieve_imeisv); /* VLR callback for ops.set_ciph_mode() */ int msc_a_vlr_set_cipher_mode(void *_msc_a, bool umts_aka, bool retrieve_imeisv) { struct msc_a *msc_a = _msc_a; struct vlr_subscr *vsub; if (!msc_a) { LOGP(DMSC, LOGL_ERROR, "Insufficient info to start ciphering: " "MSC-A role is NULL?!?\n"); return -EINVAL; } vsub = msc_a_vsub(msc_a); if (!vsub || !vsub->last_tuple) { LOG_MSC_A(msc_a, LOGL_ERROR, "Insufficient info to start ciphering: " "vlr_subscr is NULL?!?\n"); return -EINVAL; } if (msc_a_need_classmark_for_ciphering(msc_a)) { int rc; struct ran_msg msg = { .msg_type = RAN_MSG_CLASSMARK_REQUEST, }; rc = msc_a_ran_down(msc_a, MSC_ROLE_I, &msg); if (rc) { LOG_MSC_A(msc_a, LOGL_ERROR, "Cannot send Classmark Request\n"); return -EIO; } msc_a->state_before_classmark_update = msc_a->c.fi->state; msc_a->action_on_classmark_update = (struct msc_a_action_on_classmark_update){ .type = MSC_A_CLASSMARK_UPDATE_THEN_CIPHERING, .ciphering = { .umts_aka = umts_aka, .retrieve_imeisv = retrieve_imeisv, }, }; msc_a_state_chg(msc_a, MSC_A_ST_WAIT_CLASSMARK_UPDATE); return 0; } return msc_a_ran_enc_ciphering(msc_a, umts_aka, retrieve_imeisv); } static uint8_t filter_a5(uint8_t a5_mask, bool umts_aka) { /* With GSM AKA: allow A5/0, 1, 3 = 0b00001011 = 0xb. * UMTS aka: allow A5/0, 1, 3, 4 = 0b00011011 = 0x1b. */ return a5_mask & (umts_aka ? 0x1b : 0x0b); } static int msc_a_ran_enc_ciphering(struct msc_a *msc_a, bool umts_aka, bool retrieve_imeisv) { struct gsm_network *net; struct vlr_subscr *vsub; struct ran_msg msg; if (!msc_a) { LOGP(DMSC, LOGL_ERROR, "Insufficient info to start ciphering: " "MSC-A role is NULL?!?\n"); return -EINVAL; } net = msc_a_net(msc_a); vsub = msc_a_vsub(msc_a); if (!net || !vsub || !vsub->last_tuple) { LOG_MSC_A(msc_a, LOGL_ERROR, "Insufficient info to start ciphering: " "gsm_network and/or vlr_subscr is NULL?!?\n"); return -EINVAL; } msg = (struct ran_msg){ .msg_type = RAN_MSG_CIPHER_MODE_COMMAND, .cipher_mode_command = { .vec = vsub->last_tuple ? &vsub->last_tuple->vec : NULL, .classmark = &vsub->classmark, .geran = { .umts_aka = umts_aka, .retrieve_imeisv = retrieve_imeisv, .a5_encryption_mask = filter_a5(net->a5_encryption_mask, umts_aka), /* for ran_a.c to store the GERAN key that is actually used */ .chosen_key = &msc_a->geran_encr, }, .utran = { .uea_encryption_mask = net->uea_encryption_mask, }, }, }; if (msc_a_ran_down(msc_a, MSC_ROLE_I, &msg)) { LOG_MSC_A(msc_a, LOGL_ERROR, "Sending Cipher Mode Command failed\n"); /* Returning error to the VLR ops.set_ciph_mode() will cancel the attach. Other callers need to take * care of the return value. */ return -EINVAL; } if (msc_a->geran_encr.key_len) LOG_MSC_A(msc_a, LOGL_DEBUG, "RAN encoding chose ciphering: A5/%d kc %s kc128 %s\n", msc_a->geran_encr.alg_id - 1, osmo_hexdump_nospc_c(OTC_SELECT, msc_a->geran_encr.key, msc_a->geran_encr.key_len), msc_a->geran_encr.kc128_present ? osmo_hexdump_nospc_c(OTC_SELECT, msc_a->geran_encr.kc128, sizeof(msc_a->geran_encr.kc128)) : "-"); return 0; } static void msc_a_fsm_auth_ciph(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct msc_a *msc_a = fi->priv; /* If accepted, transition the state, all other cases mean failure. */ switch (event) { case MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST: case MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST: msc_a_ran_dec(msc_a, data, MSC_ROLE_I); return; case MSC_A_EV_AUTHENTICATED: msc_a_state_chg(msc_a, MSC_A_ST_AUTHENTICATED); return; case MSC_A_EV_UNUSED: msc_a_state_chg(msc_a, MSC_A_ST_RELEASING); return; case MSC_A_EV_MO_CLOSE: case MSC_A_EV_CN_CLOSE: evaluate_acceptance_outcome(fi, false); msc_a_state_chg(msc_a, MSC_A_ST_RELEASING); return; default: OSMO_ASSERT(false); } } static void msc_a_fsm_wait_classmark_update(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct msc_a *msc_a = fi->priv; switch (event) { case MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST: case MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST: msc_a_ran_dec(msc_a, data, MSC_ROLE_I); return; case MSC_A_EV_CLASSMARK_UPDATE: switch (msc_a->action_on_classmark_update.type) { case MSC_A_CLASSMARK_UPDATE_THEN_CIPHERING: msc_a_state_chg(msc_a, MSC_A_ST_AUTH_CIPH); if (msc_a_ran_enc_ciphering(msc_a, msc_a->action_on_classmark_update.ciphering.umts_aka, msc_a->action_on_classmark_update.ciphering.retrieve_imeisv)) { LOG_MSC_A(msc_a, LOGL_ERROR, "After Classmark Update, still failed to send Cipher Mode Command\n"); msc_a_state_chg(msc_a, MSC_A_ST_RELEASING); } return; default: LOG_MSC_A(msc_a, LOGL_ERROR, "Internal error: After Classmark Update, don't know what to do\n"); msc_a_state_chg(msc_a, msc_a->state_before_classmark_update); return; } case MSC_A_EV_UNUSED: /* Seems something detached / aborted in the middle of auth+ciph. */ evaluate_acceptance_outcome(fi, false); msc_a_state_chg(msc_a, MSC_A_ST_RELEASING); return; case MSC_A_EV_MO_CLOSE: case MSC_A_EV_CN_CLOSE: evaluate_acceptance_outcome(fi, false); msc_a_state_chg(msc_a, MSC_A_ST_RELEASING); return; default: OSMO_ASSERT(false); } } static bool msc_a_fsm_has_active_transactions(struct osmo_fsm_inst *fi) { struct msc_a *msc_a = fi->priv; struct vlr_subscr *vsub = msc_a_vsub(msc_a); struct gsm_trans *trans; if (osmo_use_count_by(&msc_a->use_count, MSC_A_USE_SILENT_CALL)) { LOG_MSC_A(msc_a, LOGL_DEBUG, "%s: silent call still active\n", __func__); return true; } if (osmo_use_count_by(&msc_a->use_count, MSC_A_USE_CM_SERVICE_CC)) { LOG_MSC_A(msc_a, LOGL_DEBUG, "%s: still awaiting MO CC request after a CM Service Request\n", __func__); return true; } if (osmo_use_count_by(&msc_a->use_count, MSC_A_USE_CM_SERVICE_GCC)) { LOG_MSC_A(msc_a, LOGL_DEBUG, "%s: still awaiting MO GCC request after a CM Service Request\n", __func__); return true; } if (osmo_use_count_by(&msc_a->use_count, MSC_A_USE_CM_SERVICE_BCC)) { LOG_MSC_A(msc_a, LOGL_DEBUG, "%s: still awaiting MO BCC request after a CM Service Request\n", __func__); return true; } if (osmo_use_count_by(&msc_a->use_count, MSC_A_USE_CM_SERVICE_SMS)) { LOG_MSC_A(msc_a, LOGL_DEBUG, "%s: still awaiting MO SMS after a CM Service Request\n", __func__); return true; } if (osmo_use_count_by(&msc_a->use_count, MSC_A_USE_CM_SERVICE_SS)) { LOG_MSC_A(msc_a, LOGL_DEBUG, "%s: still awaiting MO SS after a CM Service Request\n", __func__); return true; } if (vsub && !llist_empty(&vsub->cs.requests)) { struct paging_request *pr; llist_for_each_entry(pr, &vsub->cs.requests, entry) { LOG_MSC_A(msc_a, LOGL_DEBUG, "%s: still active: %s\n", __func__, pr->label); } return true; } if ((trans = trans_has_conn(msc_a))) { LOG_MSC_A(msc_a, LOGL_DEBUG, "connection still has active transaction: %s\n", trans_type_name(trans->type)); return true; } return false; } static void msc_a_fsm_authenticated_enter(struct osmo_fsm_inst *fi, uint32_t prev_state) { struct msc_a *msc_a = fi->priv; struct vlr_subscr *vsub = msc_a_vsub(msc_a); /* Stop Location Update expiry for this subscriber. While the subscriber * has an open connection the LU expiry timer must remain disabled. * Otherwise we would kick the subscriber off the network when the timer * expires e.g. during a long phone call. * The LU expiry timer will restart once the connection is closed. */ if (vsub) vsub->expire_lu = VLR_SUBSCRIBER_NO_EXPIRATION; evaluate_acceptance_outcome(fi, true); } static void msc_a_fsm_authenticated(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct msc_a *msc_a = fi->priv; switch (event) { case MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST: case MSC_A_EV_FROM_I_PREPARE_SUBSEQUENT_HANDOVER_REQUEST: case MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST: msc_a_ran_dec(msc_a, data, MSC_ROLE_I); return; case MSC_A_EV_COMPLETE_LAYER_3_OK: /* When Authentication is off, we may already be in the Accepted state when the code * evaluates the Compl L3. Simply ignore. This just cosmetically mutes the error log * about the useless event. */ return; case MSC_A_EV_TRANSACTION_ACCEPTED: msc_a_state_chg(msc_a, MSC_A_ST_COMMUNICATING); return; case MSC_A_EV_MO_CLOSE: case MSC_A_EV_CN_CLOSE: case MSC_A_EV_UNUSED: msc_a_state_chg(msc_a, MSC_A_ST_RELEASING); return; default: OSMO_ASSERT(false); } } static struct call_leg *msc_a_ensure_call_leg(struct msc_a *msc_a, struct gsm_trans *for_cc_trans) { struct call_leg *cl = msc_a->cc.call_leg; struct gsm_network *net = msc_a_net(msc_a); /* Ensure that events about RTP endpoints coming from the msc_a->cc.call_leg know which gsm_trans to abort on * error */ if (!msc_a->cc.active_trans) msc_a->cc.active_trans = for_cc_trans; if (msc_a->cc.active_trans != for_cc_trans) { LOG_TRANS(for_cc_trans, LOGL_ERROR, "Cannot create call leg, another trans is already active for this conn\n"); return NULL; } if (!cl) { cl = msc_a->cc.call_leg = call_leg_alloc(msc_a->c.fi, MSC_EV_CALL_LEG_TERM, MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE, MSC_EV_CALL_LEG_RTP_COMPLETE); OSMO_ASSERT(cl); if (net->use_osmux != OSMUX_USAGE_OFF) { struct msc_i *msc_i = msc_a_msc_i(msc_a); if (msc_i->c.remote_to) { /* TODO: investigate what to do in this case */ LOG_MSC_A(msc_a, LOGL_ERROR, "Osmux not yet supported for inter-MSC"); } else { cl->ran_peer_supports_osmux = msc_i->ran_conn->ran_peer->remote_supports_osmux; } } } return cl; } int msc_a_ensure_cn_local_rtp(struct msc_a *msc_a, struct gsm_trans *cc_trans) { struct call_leg *cl; struct rtp_stream *rtp_to_ran; cl = msc_a_ensure_call_leg(msc_a, cc_trans); if (!cl) return -EINVAL; rtp_to_ran = cl->rtp[RTP_TO_RAN]; if (call_leg_local_ip(cl, RTP_TO_CN)) { /* Already has an RTP address and port towards the CN, continue right away. */ return osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE, cl->rtp[RTP_TO_CN]); } /* No CN RTP address available yet, ask the MGW to create one. * Set a codec to be used: if Assignment on the RAN side is already done, take the same codec as the RTP_TO_RAN. * If no RAN side RTP is established, try to guess a preliminary codec from SDP -- before Assignment, picking a * codec from the SDP is more politeness/avoiding confusion than necessity. The actual codec to be used would be * determined later. If no codec could be determined, pass none for the time being. */ return call_leg_ensure_ci(cl, RTP_TO_CN, cc_trans->call_id, cc_trans, rtp_to_ran->codecs_known ? &rtp_to_ran->codecs : NULL, NULL); } static void assignment_request_timeout_cb(void *data); /* The MGW has given us a local IP address for the RAN side. Ready to start the Assignment of a voice channel. */ void msc_a_tx_assignment_cmd(struct msc_a *msc_a) { struct ran_msg msg; struct gsm_trans *cc_trans = msc_a->cc.active_trans; struct gsm0808_channel_type channel_type; /* Do not dispatch another Assignment Command before an earlier assignment is completed. This is a sanity * safeguard, ideally callers should not even invoke this function when an Assignment is already ongoing. * (There is no osmo_fsm for Assignment / the CC trans code; when we refactor that one day, this timer should be * an FSM state.) */ if (osmo_timer_pending(&msc_a->cc.assignment_request_pending)) { LOG_MSC_A(msc_a, LOGL_ERROR, "Not transmitting Assignment, still waiting for the response to an earlier Assignment\n"); return; } osmo_timer_setup(&msc_a->cc.assignment_request_pending, assignment_request_timeout_cb, msc_a); osmo_timer_schedule(&msc_a->cc.assignment_request_pending, osmo_tdef_get(msc_a->c.ran->tdefs, -37, OSMO_TDEF_S, 10), 0); if (!cc_trans) { LOG_MSC_A(msc_a, LOGL_ERROR, "No CC transaction active\n"); call_leg_release(msc_a->cc.call_leg); return; } trans_cc_filter_run(cc_trans); LOG_TRANS(cc_trans, LOGL_DEBUG, "Sending Assignment Command\n"); switch (cc_trans->bearer_cap.transfer) { case GSM48_BCAP_ITCAP_SPEECH: if (!cc_trans->cc.local.audio_codecs.count) { LOG_TRANS(cc_trans, LOGL_ERROR, "Assignment not possible, no matching codec: %s\n", codec_filter_to_str(&cc_trans->cc.codecs, &cc_trans->cc.local, &cc_trans->cc.remote)); call_leg_release(msc_a->cc.call_leg); return; } /* Compose 48.008 Channel Type from the current set of codecs * determined from both local and remote codec capabilities. */ if (sdp_audio_codecs_to_gsm0808_channel_type(&channel_type, &cc_trans->cc.local.audio_codecs)) { LOG_MSC_A(msc_a, LOGL_ERROR, "Cannot compose Channel Type (Permitted Speech) from codecs: %s\n", codec_filter_to_str(&cc_trans->cc.codecs, &cc_trans->cc.local, &cc_trans->cc.remote)); trans_free(cc_trans); return; } break; case GSM48_BCAP_ITCAP_3k1_AUDIO: case GSM48_BCAP_ITCAP_FAX_G3: case GSM48_BCAP_ITCAP_UNR_DIG_INF: if (!cc_trans->cc.local.bearer_services.count) { LOG_TRANS(cc_trans, LOGL_ERROR, "Assignment not possible, no matching bearer service: %s\n", csd_filter_to_str(&cc_trans->cc.csd, &cc_trans->cc.local, &cc_trans->cc.remote)); call_leg_release(msc_a->cc.call_leg); return; } /* Compose 48.008 Channel Type from the current set of bearer * services determined from local and remote capabilities. */ if (csd_bs_list_to_gsm0808_channel_type(&channel_type, &cc_trans->cc.local.bearer_services)) { LOG_MSC_A(msc_a, LOGL_ERROR, "Cannot compose channel type from: %s\n", csd_filter_to_str(&cc_trans->cc.csd, &cc_trans->cc.local, &cc_trans->cc.remote)); return; } break; default: LOG_TRANS(cc_trans, LOGL_ERROR, "Assignment not possible for information transfer capability %d\n", cc_trans->bearer_cap.transfer); call_leg_release(msc_a->cc.call_leg); return; } /* The RAN side RTP address is known, so the voice/CSD Assignment can commence. */ msg = (struct ran_msg){ .msg_type = RAN_MSG_ASSIGNMENT_COMMAND, .assignment_command = { .cn_rtp = &msc_a->cc.call_leg->rtp[RTP_TO_RAN]->local, .channel_type = &channel_type, .osmux_present = msc_a->cc.call_leg->rtp[RTP_TO_RAN]->use_osmux, .osmux_cid = msc_a->cc.call_leg->rtp[RTP_TO_RAN]->local_osmux_cid, .call_id_present = true, .call_id = cc_trans->call_id, .lcls = cc_trans->cc.lcls, }, }; if (msc_a_ran_down(msc_a, MSC_ROLE_I, &msg)) { LOG_MSC_A(msc_a, LOGL_ERROR, "Cannot send Assignment\n"); trans_free(cc_trans); return; } } static struct gsm_trans *find_waiting_call(struct msc_a *msc_a) { struct gsm_trans *trans; struct gsm_network *net = msc_a_net(msc_a); llist_for_each_entry(trans, &net->trans_list, entry) { if (trans->msc_a != msc_a) continue; if (trans->type != TRANS_CC) continue; if (trans->msc_a->cc.active_trans == trans) continue; return trans; } return NULL; } static void msc_a_cleanup_rtp_streams(struct msc_a *msc_a, uint32_t event, void *data) { switch (event) { case MSC_EV_CALL_LEG_TERM: msc_a->cc.call_leg = NULL; if (msc_a->cc.mncc_forwarding_to_remote_ran) msc_a->cc.mncc_forwarding_to_remote_ran->rtps = NULL; if (msc_a->ho.new_cell.mncc_forwarding_to_remote_ran) msc_a->ho.new_cell.mncc_forwarding_to_remote_ran->rtps = NULL; return; case MSC_MNCC_EV_CALL_ENDED: msc_a->cc.mncc_forwarding_to_remote_ran = NULL; return; default: return; } } static void msc_a_fsm_communicating(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct msc_a *msc_a = fi->priv; struct rtp_stream *rtps; struct gsm_trans *waiting_trans; struct an_apdu *an_apdu; msc_a_cleanup_rtp_streams(msc_a, event, data); switch (event) { case MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST: case MSC_A_EV_FROM_I_PREPARE_SUBSEQUENT_HANDOVER_REQUEST: case MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST: an_apdu = data; msc_a_ran_dec(msc_a, an_apdu, MSC_ROLE_I); return; case MSC_A_EV_FROM_T_PREPARE_HANDOVER_RESPONSE: case MSC_A_EV_FROM_T_PREPARE_HANDOVER_FAILURE: case MSC_A_EV_FROM_T_PROCESS_ACCESS_SIGNALLING_REQUEST: case MSC_A_EV_FROM_T_SEND_END_SIGNAL_REQUEST: an_apdu = data; msc_a_ran_dec(msc_a, an_apdu, MSC_ROLE_T); return; case MSC_A_EV_TRANSACTION_ACCEPTED: /* no-op */ return; case MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE: rtps = data; if (!rtps) { LOG_MSC_A(msc_a, LOGL_ERROR, "Invalid data for %s\n", osmo_fsm_event_name(fi->fsm, event)); return; } if (!msc_a->cc.call_leg) { LOG_MSC_A(msc_a, LOGL_ERROR, "No call leg active\n"); return; } if (!osmo_sockaddr_str_is_nonzero(&rtps->local)) { LOG_MSC_A(msc_a, LOGL_ERROR, "Invalid RTP address received from MGW: " OSMO_SOCKADDR_STR_FMT "\n", OSMO_SOCKADDR_STR_FMT_ARGS(&rtps->local)); call_leg_release(msc_a->cc.call_leg); return; } LOG_MSC_A(msc_a, LOGL_DEBUG, "MGW endpoint's RTP address available for the CI %s: " OSMO_SOCKADDR_STR_FMT " (osmux=%s:%d)\n", rtp_direction_name(rtps->dir), OSMO_SOCKADDR_STR_FMT_ARGS(&rtps->local), rtps->use_osmux ? "yes" : "no", rtps->local_osmux_cid); switch (rtps->dir) { case RTP_TO_RAN: msc_a_tx_assignment_cmd(msc_a); return; case RTP_TO_CN: cc_on_cn_local_rtp_port_known(rtps->for_trans); return; default: LOG_MSC_A(msc_a, LOGL_ERROR, "Invalid data for %s\n", osmo_fsm_event_name(fi->fsm, event)); return; } case MSC_EV_CALL_LEG_RTP_COMPLETE: /* Nothing to do. */ return; case MSC_MNCC_EV_CALL_ENDED: /* Cleaned up above */ return; case MSC_EV_CALL_LEG_TERM: /* RTP streams cleaned up above */ msc_a_get(msc_a, __func__); if (msc_a->cc.active_trans) trans_free(msc_a->cc.active_trans); /* If there is another call still waiting to be activated, this is the time when the mgcp_ctx is * available again and the other call can start assigning. */ waiting_trans = find_waiting_call(msc_a); if (waiting_trans) { LOG_MSC_A(msc_a, LOGL_DEBUG, "(ti %02x) Call waiting: starting Assignment\n", waiting_trans->transaction_id); msc_a_try_call_assignment(waiting_trans); } msc_a_put(msc_a, __func__); return; case MSC_A_EV_HANDOVER_REQUIRED: msc_ho_start(msc_a, (struct ran_handover_required*)data); return; case MSC_A_EV_HANDOVER_END: /* Termination event of the msc_ho_fsm. No action needed, it's all done in the msc_ho_fsm cleanup. This * event only exists because osmo_fsm_inst_alloc_child() requires a parent term event; and maybe * interesting for logging. */ return; case MSC_A_EV_MO_CLOSE: case MSC_A_EV_CN_CLOSE: case MSC_A_EV_UNUSED: msc_a_state_chg(msc_a, MSC_A_ST_RELEASING); return; default: OSMO_ASSERT(false); } } static int msc_a_fsm_timer_cb(struct osmo_fsm_inst *fi) { struct msc_a *msc_a = fi->priv; if (msc_a_in_release(msc_a)) { LOG_MSC_A(msc_a, LOGL_ERROR, "Timeout while releasing, discarding right now\n"); msc_a_put_all(msc_a, MSC_A_USE_WAIT_CLEAR_COMPLETE); msc_a_state_chg(msc_a, MSC_A_ST_RELEASED); } else { enum gsm48_reject_value cause = GSM48_REJECT_CONGESTION; osmo_fsm_inst_dispatch(fi, MSC_A_EV_CN_CLOSE, &cause); } return 0; } static void msc_a_fsm_releasing_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) { struct msc_a *msc_a = fi->priv; struct vlr_subscr *vsub = msc_a_vsub(msc_a); int i; char buf[128]; const char * const use_counts_to_cancel[] = { MSC_A_USE_LOCATION_UPDATING, MSC_A_USE_CM_SERVICE_CC, MSC_A_USE_CM_SERVICE_SMS, MSC_A_USE_CM_SERVICE_SS, MSC_A_USE_CM_SERVICE_GCC, MSC_A_USE_CM_SERVICE_BCC, MSC_A_USE_PAGING_RESPONSE, }; LOG_MSC_A(msc_a, LOGL_DEBUG, "Releasing: msc_a use is %s\n", osmo_use_count_name_buf(buf, sizeof(buf), &msc_a->use_count)); if (vsub) { vlr_subscr_get(vsub, __func__); /* Cancel all VLR FSMs, if any */ vlr_subscr_cancel_attach_fsm(vsub, OSMO_FSM_TERM_ERROR, GSM48_REJECT_CONGESTION); /* The subscriber has no active connection anymore. * Restart the periodic Location Update expiry timer for this subscriber. */ vlr_subscr_enable_expire_lu(vsub); } /* We no longer care about assignment responses. */ osmo_timer_del(&msc_a->cc.assignment_request_pending); /* If we're closing in a middle of a trans, we need to clean up */ trans_conn_closed(msc_a); call_leg_release(msc_a->cc.call_leg); /* Cancel use counts for pending CM Service / Paging */ for (i = 0; i < ARRAY_SIZE(use_counts_to_cancel); i++) { const char *use = use_counts_to_cancel[i]; int32_t count = osmo_use_count_by(&msc_a->use_count, use); if (!count) continue; LOG_MSC_A(msc_a, LOGL_DEBUG, "Releasing: canceling still pending use: %s (%d)\n", use, count); osmo_use_count_get_put(&msc_a->use_count, use, -count); } if (msc_a->c.ran->type == OSMO_RAT_EUTRAN_SGS) { sgs_iface_tx_release(vsub); /* In SGsAP there is no confirmation of a release. */ msc_a_state_chg(msc_a, MSC_A_ST_RELEASED); } else { struct ran_msg msg = { .msg_type = RAN_MSG_CLEAR_COMMAND, .clear_command = { /* "Call Control" is the only cause code listed in 3GPP TS 48.008 3.2.1.21 CLEAR COMMAND * that qualifies for a normal release situation. (OS#4664) */ .gsm0808_cause = GSM0808_CAUSE_CALL_CONTROL, .csfb_ind = (vsub && vsub->sgs_fsm->state == SGS_UE_ST_ASSOCIATED), }, }; msc_a_get(msc_a, MSC_A_USE_WAIT_CLEAR_COMPLETE); msc_a_ran_down(msc_a, MSC_ROLE_I, &msg); /* The connection is cleared. The MS will now go back to 4G, Switch the RAN type back to SGS. */ if (vsub && vsub->sgs_fsm->state == SGS_UE_ST_ASSOCIATED) vsub->cs.attached_via_ran = OSMO_RAT_EUTRAN_SGS; } if (vsub) vlr_subscr_put(vsub, __func__); } static void msc_a_fsm_releasing(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct msc_a *msc_a = fi->priv; msc_a_cleanup_rtp_streams(msc_a, event, data); switch (event) { case MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST: case MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST: msc_a_ran_dec(msc_a, data, MSC_ROLE_I); return; case MSC_A_EV_MO_CLOSE: case MSC_A_EV_CN_CLOSE: case MSC_A_EV_UNUSED: /* Already releasing */ return; case MSC_EV_CALL_LEG_TERM: case MSC_MNCC_EV_CALL_ENDED: /* RTP streams cleaned up above */ return; case MSC_A_EV_HANDOVER_END: /* msc_ho_fsm does cleanup. */ return; default: OSMO_ASSERT(false); } } static void msc_a_fsm_released_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) { struct msc_a *msc_a = msc_a_fi_priv(fi); char buf[128]; LOG_MSC_A(msc_a, LOGL_DEBUG, "Released: msc_a use is %s\n", osmo_use_count_name_buf(buf, sizeof(buf), &msc_a->use_count)); if (osmo_use_count_total(&msc_a->use_count) == 0) osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, fi); } static void msc_a_fsm_released(struct osmo_fsm_inst *fi, uint32_t event, void *data) { if (event == MSC_A_EV_UNUSED) osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, fi); } void msc_a_fsm_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause) { struct msc_a *msc_a = msc_a_fi_priv(fi); struct vlr_subscr *vsub = msc_a_vsub(msc_a); trans_conn_closed(msc_a); if (msc_a_fsm_has_active_transactions(fi)) LOG_MSC_A(msc_a, LOGL_ERROR, "Deallocating active transactions failed\n"); LOG_MSC_A_CAT(msc_a, DREF, LOGL_DEBUG, "max total use count was %d\n", msc_a->max_total_use_count); /* Invalidate the active conn in VLR subscriber state, if any. */ if (vsub && vsub->msc_conn_ref == msc_a) vsub->msc_conn_ref = NULL; osmo_timer_del(&msc_a->lu_delay_timer); osmo_timer_del(&msc_a->cc.assignment_request_pending); } const struct value_string msc_a_fsm_event_names[] = { OSMO_VALUE_STRING(MSC_REMOTE_EV_RX_GSUP), OSMO_VALUE_STRING(MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE), OSMO_VALUE_STRING(MSC_EV_CALL_LEG_RTP_COMPLETE), OSMO_VALUE_STRING(MSC_EV_CALL_LEG_TERM), OSMO_VALUE_STRING(MSC_MNCC_EV_NEED_LOCAL_RTP), OSMO_VALUE_STRING(MSC_MNCC_EV_CALL_PROCEEDING), OSMO_VALUE_STRING(MSC_MNCC_EV_CALL_COMPLETE), OSMO_VALUE_STRING(MSC_MNCC_EV_CALL_ENDED), OSMO_VALUE_STRING(MSC_A_EV_FROM_I_COMPLETE_LAYER_3), OSMO_VALUE_STRING(MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST), OSMO_VALUE_STRING(MSC_A_EV_FROM_I_PREPARE_SUBSEQUENT_HANDOVER_REQUEST), OSMO_VALUE_STRING(MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST), OSMO_VALUE_STRING(MSC_A_EV_FROM_T_PROCESS_ACCESS_SIGNALLING_REQUEST), OSMO_VALUE_STRING(MSC_A_EV_FROM_T_PREPARE_HANDOVER_RESPONSE), OSMO_VALUE_STRING(MSC_A_EV_FROM_T_PREPARE_HANDOVER_FAILURE), OSMO_VALUE_STRING(MSC_A_EV_FROM_T_SEND_END_SIGNAL_REQUEST), OSMO_VALUE_STRING(MSC_A_EV_COMPLETE_LAYER_3_OK), OSMO_VALUE_STRING(MSC_A_EV_CLASSMARK_UPDATE), OSMO_VALUE_STRING(MSC_A_EV_AUTHENTICATED), OSMO_VALUE_STRING(MSC_A_EV_TRANSACTION_ACCEPTED), OSMO_VALUE_STRING(MSC_A_EV_CN_CLOSE), OSMO_VALUE_STRING(MSC_A_EV_MO_CLOSE), OSMO_VALUE_STRING(MSC_A_EV_UNUSED), OSMO_VALUE_STRING(MSC_A_EV_HANDOVER_REQUIRED), OSMO_VALUE_STRING(MSC_A_EV_HANDOVER_END), {} }; #define S(x) (1 << (x)) static const struct osmo_fsm_state msc_a_fsm_states[] = { [MSC_A_ST_VALIDATE_L3] = { .name = OSMO_STRINGIFY(MSC_A_ST_VALIDATE_L3), .in_event_mask = 0 | S(MSC_A_EV_FROM_I_COMPLETE_LAYER_3) | S(MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST) | S(MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST) | S(MSC_A_EV_COMPLETE_LAYER_3_OK) | S(MSC_A_EV_MO_CLOSE) | S(MSC_A_EV_CN_CLOSE) | S(MSC_A_EV_UNUSED) , .out_state_mask = 0 | S(MSC_A_ST_VALIDATE_L3) | S(MSC_A_ST_AUTH_CIPH) | S(MSC_A_ST_RELEASING) , .action = msc_a_fsm_validate_l3, }, [MSC_A_ST_AUTH_CIPH] = { .name = OSMO_STRINGIFY(MSC_A_ST_AUTH_CIPH), .in_event_mask = 0 | S(MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST) | S(MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST) | S(MSC_A_EV_AUTHENTICATED) | S(MSC_A_EV_MO_CLOSE) | S(MSC_A_EV_CN_CLOSE) | S(MSC_A_EV_UNUSED) , .out_state_mask = 0 | S(MSC_A_ST_WAIT_CLASSMARK_UPDATE) | S(MSC_A_ST_AUTHENTICATED) | S(MSC_A_ST_RELEASING) , .action = msc_a_fsm_auth_ciph, }, [MSC_A_ST_WAIT_CLASSMARK_UPDATE] = { .name = OSMO_STRINGIFY(MSC_A_ST_WAIT_CLASSMARK_UPDATE), .in_event_mask = 0 | S(MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST) | S(MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST) | S(MSC_A_EV_CLASSMARK_UPDATE) | S(MSC_A_EV_MO_CLOSE) | S(MSC_A_EV_CN_CLOSE) , .out_state_mask = 0 | S(MSC_A_ST_AUTH_CIPH) | S(MSC_A_ST_RELEASING) , .action = msc_a_fsm_wait_classmark_update, }, [MSC_A_ST_AUTHENTICATED] = { .name = OSMO_STRINGIFY(MSC_A_ST_AUTHENTICATED), /* allow everything to release for any odd behavior */ .in_event_mask = 0 | S(MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST) | S(MSC_A_EV_FROM_I_PREPARE_SUBSEQUENT_HANDOVER_REQUEST) | S(MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST) | S(MSC_A_EV_TRANSACTION_ACCEPTED) | S(MSC_A_EV_MO_CLOSE) | S(MSC_A_EV_CN_CLOSE) | S(MSC_A_EV_UNUSED) , .out_state_mask = 0 | S(MSC_A_ST_RELEASING) | S(MSC_A_ST_COMMUNICATING) , .onenter = msc_a_fsm_authenticated_enter, .action = msc_a_fsm_authenticated, }, [MSC_A_ST_COMMUNICATING] = { .name = OSMO_STRINGIFY(MSC_A_ST_COMMUNICATING), /* allow everything to release for any odd behavior */ .in_event_mask = 0 | S(MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST) | S(MSC_A_EV_FROM_I_PREPARE_SUBSEQUENT_HANDOVER_REQUEST) | S(MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST) | S(MSC_A_EV_FROM_T_PREPARE_HANDOVER_RESPONSE) | S(MSC_A_EV_FROM_T_PREPARE_HANDOVER_FAILURE) | S(MSC_A_EV_FROM_T_PROCESS_ACCESS_SIGNALLING_REQUEST) | S(MSC_A_EV_FROM_T_SEND_END_SIGNAL_REQUEST) | S(MSC_A_EV_TRANSACTION_ACCEPTED) | S(MSC_A_EV_MO_CLOSE) | S(MSC_A_EV_CN_CLOSE) | S(MSC_A_EV_UNUSED) | S(MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE) | S(MSC_EV_CALL_LEG_RTP_COMPLETE) | S(MSC_EV_CALL_LEG_TERM) | S(MSC_MNCC_EV_CALL_ENDED) | S(MSC_A_EV_HANDOVER_REQUIRED) | S(MSC_A_EV_HANDOVER_END) , .out_state_mask = 0 | S(MSC_A_ST_RELEASING) , .action = msc_a_fsm_communicating, }, [MSC_A_ST_RELEASING] = { .name = OSMO_STRINGIFY(MSC_A_ST_RELEASING), .in_event_mask = 0 | S(MSC_A_EV_FROM_I_PROCESS_ACCESS_SIGNALLING_REQUEST) | S(MSC_A_EV_FROM_I_SEND_END_SIGNAL_REQUEST) | S(MSC_A_EV_UNUSED) | S(MSC_EV_CALL_LEG_TERM) | S(MSC_MNCC_EV_CALL_ENDED) | S(MSC_A_EV_HANDOVER_END) | S(MSC_A_EV_CN_CLOSE) , .out_state_mask = 0 | S(MSC_A_ST_RELEASED) , .onenter = msc_a_fsm_releasing_onenter, .action = msc_a_fsm_releasing, }, [MSC_A_ST_RELEASED] = { .name = OSMO_STRINGIFY(MSC_A_ST_RELEASED), .in_event_mask = 0 | S(MSC_A_EV_UNUSED) , .onenter = msc_a_fsm_released_onenter, .action = msc_a_fsm_released, }, }; static struct osmo_fsm msc_a_fsm = { .name = "msc_a", .states = msc_a_fsm_states, .num_states = ARRAY_SIZE(msc_a_fsm_states), .log_subsys = DMSC, .event_names = msc_a_fsm_event_names, .timer_cb = msc_a_fsm_timer_cb, .cleanup = msc_a_fsm_cleanup, }; static __attribute__((constructor)) void msc_a_fsm_init() { OSMO_ASSERT(osmo_fsm_register(&msc_a_fsm) == 0); } static int msc_a_use_cb(struct osmo_use_count_entry *e, int32_t old_use_count, const char *file, int line) { struct msc_a *msc_a = e->use_count->talloc_object; char buf[128]; int32_t total; int level; if (!e->use) return -EINVAL; total = osmo_use_count_total(&msc_a->use_count); if (total == 0 || (total == 1 && old_use_count == 0 && e->count == 1)) level = LOGL_INFO; else level = LOGL_DEBUG; LOG_MSC_A_CAT_SRC(msc_a, DREF, level, file, line, "%s %s: now used by %s\n", (e->count - old_use_count) > 0? "+" : "-", e->use, osmo_use_count_name_buf(buf, sizeof(buf), &msc_a->use_count)); if (e->count < 0) return -ERANGE; msc_a->max_total_use_count = OSMO_MAX(msc_a->max_total_use_count, total); if (total == 0) osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_UNUSED, NULL); return 0; } struct msc_a *msc_a_alloc(struct msub *msub, struct ran_infra *ran) { struct msc_a *msc_a = msub_role_alloc(msub, MSC_ROLE_A, &msc_a_fsm, struct msc_a, ran); msc_a->use_count = (struct osmo_use_count){ .talloc_object = msc_a, .use_cb = msc_a_use_cb, }; osmo_use_count_make_static_entries(&msc_a->use_count, msc_a->use_count_buf, ARRAY_SIZE(msc_a->use_count_buf)); /* Start timeout for first state */ msc_a_state_chg_always(msc_a, MSC_A_ST_VALIDATE_L3); osmo_timer_setup(&msc_a->lu_delay_timer, &lu_delay_timer_cb, msc_a); return msc_a; } bool msc_a_is_establishing_auth_ciph(const struct msc_a *msc_a) { if (!msc_a || !msc_a->c.fi) return false; return msc_a->c.fi->state == MSC_A_ST_AUTH_CIPH; } const struct value_string complete_layer3_type_names[] = { { COMPLETE_LAYER3_NONE, "NONE" }, { COMPLETE_LAYER3_LU, "LU" }, { COMPLETE_LAYER3_CM_SERVICE_REQ, "CM_SERVICE_REQ" }, { COMPLETE_LAYER3_PAGING_RESP, "PAGING_RESP" }, { COMPLETE_LAYER3_CM_RE_ESTABLISH_REQ, "CM_RE_ESTABLISH_REQ" }, { 0, NULL } }; #define _msc_a_update_id(MSC_A, FMT, ARGS ...) \ do { \ if (osmo_fsm_inst_update_id_f(msc_a->c.fi, FMT ":%s:%s", \ ## ARGS, \ msub_ran_conn_name(msc_a->c.msub), \ complete_layer3_type_name(msc_a->complete_layer3_type)) \ == 0) { \ struct vlr_subscr *_vsub = msc_a_vsub(MSC_A); \ if (_vsub) { \ if (_vsub->lu_fsm) \ osmo_fsm_inst_update_id(_vsub->lu_fsm, (MSC_A)->c.fi->id); \ if (_vsub->auth_fsm) \ osmo_fsm_inst_update_id(_vsub->auth_fsm, (MSC_A)->c.fi->id); \ if (_vsub->proc_arq_fsm) \ osmo_fsm_inst_update_id(_vsub->proc_arq_fsm, (MSC_A)->c.fi->id); \ } \ LOG_MSC_A(MSC_A, LOGL_DEBUG, "Updated ID\n"); \ } \ /* otherwise osmo_fsm_inst_update_id_f() will log an error. */ \ } while (0) /* Compose an ID almost like gsm48_mi_to_string(), but print the MI type along, and print a TMSI as hex. */ void msc_a_update_id_from_mi(struct msc_a *msc_a, const struct osmo_mobile_identity *mi) { _msc_a_update_id(msc_a, "%s", osmo_mobile_identity_to_str_c(OTC_SELECT, mi)); } /* Update msc_a->fi id string from current msc_a->vsub and msc_a->complete_layer3_type. */ void msc_a_update_id(struct msc_a *msc_a) { _msc_a_update_id(msc_a, "%s", vlr_subscr_name(msc_a_vsub(msc_a))); } /* Iterate all msc_a instances that are relevant for this subscriber, and update FSM ID strings for all of the FSM * instances. */ void msc_a_update_id_for_vsub(struct vlr_subscr *for_vsub) { struct msub *msub; llist_for_each_entry(msub, &msub_list, entry) { struct vlr_subscr *vsub = msub_vsub(msub); if (vsub != for_vsub) continue; msc_a_update_id(msub_msc_a(msub)); } } static bool msg_is_initially_permitted(const struct gsm48_hdr *hdr) { uint8_t pdisc = gsm48_hdr_pdisc(hdr); uint8_t msg_type = gsm48_hdr_msg_type(hdr); switch (pdisc) { case GSM48_PDISC_MM: switch (msg_type) { case GSM48_MT_MM_LOC_UPD_REQUEST: case GSM48_MT_MM_CM_SERV_REQ: case GSM48_MT_MM_CM_REEST_REQ: case GSM48_MT_MM_AUTH_RESP: case GSM48_MT_MM_AUTH_FAIL: case GSM48_MT_MM_ID_RESP: case GSM48_MT_MM_TMSI_REALL_COMPL: case GSM48_MT_MM_IMSI_DETACH_IND: return true; default: break; } break; case GSM48_PDISC_RR: switch (msg_type) { /* GSM48_MT_RR_CIPH_M_COMPL is actually handled in bssmap_rx_ciph_compl() and gets redirected in the * BSSAP layer to ran_conn_cipher_mode_compl() (before this here is reached) */ case GSM48_MT_RR_PAG_RESP: case GSM48_MT_RR_CIPH_M_COMPL: return true; default: break; } break; default: break; } return false; } /* Main entry point for GSM 04.08/44.008 Layer 3 data (e.g. from the BSC). */ int msc_a_up_l3(struct msc_a *msc_a, struct msgb *msg) { struct gsm48_hdr *gh; uint8_t pdisc; int rc; struct vlr_subscr *vsub = msc_a_vsub(msc_a); int is_r99; OSMO_ASSERT(msg->l3h); OSMO_ASSERT(msg); gh = msgb_l3(msg); pdisc = gsm48_hdr_pdisc(gh); LOG_MSC_A_CAT(msc_a, DRLL, LOGL_DEBUG, "Dispatching 04.08 message: %s %s\n", gsm48_pdisc_name(pdisc), gsm48_pdisc_msgtype_name(pdisc, gsm48_hdr_msg_type(gh))); /* To evaluate the 3GPP TS 24.007 Duplicate Detection, we need Classmark information on whether the MS is R99 * capable. If the subscriber is already actively connected, the Classmark information is stored with the * vlr_subscr. Otherwise, this *must* be a Complete Layer 3 with Classmark info. */ if (vsub) is_r99 = osmo_gsm48_classmark_is_r99(&vsub->classmark) ? 1 : 0; else is_r99 = compl_l3_msg_is_r99(msg); if (is_r99 < 0) { LOG_MSC_A(msc_a, LOGL_ERROR, "No Classmark Information, dropping non-Complete-Layer3 message: %s\n", gsm48_pdisc_msgtype_name(pdisc, gsm48_hdr_msg_type(gh))); return -EACCES; } if (is_r99 >= 0 && ran_dec_dtap_undup_is_duplicate(msc_a->c.fi, msc_a->n_sd_next, is_r99 ? true : false, msg)) { LOG_MSC_A(msc_a, LOGL_DEBUG, "Dropping duplicate message" " (3GPP TS 24.007 11.2.3.2 Message Type Octet / Duplicate Detection)\n"); return 0; } if (!msc_a_is_accepted(msc_a) && !msg_is_initially_permitted(gh)) { LOG_MSC_A(msc_a, LOGL_ERROR, "Message not permitted for initial conn: %s\n", gsm48_pdisc_msgtype_name(pdisc, gsm48_hdr_msg_type(gh))); return -EACCES; } if (vsub && vsub->cs.attached_via_ran != msc_a->c.ran->type) { LOG_MSC_A(msc_a, LOGL_ERROR, "Illegal situation: RAN type mismatch:" " attached via %s, received message via %s\n", osmo_rat_type_name(vsub->cs.attached_via_ran), osmo_rat_type_name(msc_a->c.ran->type)); return -EACCES; } #if 0 if (silent_call_reroute(conn, msg)) return silent_call_rx(conn, msg); #endif switch (pdisc) { case GSM48_PDISC_GROUP_CC: case GSM48_PDISC_BCAST_CC: rc = gsm44068_rcv_bcc_gcc(msc_a, NULL, msg); break; case GSM48_PDISC_CC: rc = gsm0408_rcv_cc(msc_a, msg); break; case GSM48_PDISC_MM: rc = gsm0408_rcv_mm(msc_a, msg); break; case GSM48_PDISC_RR: rc = gsm0408_rcv_rr(msc_a, msg); break; case GSM48_PDISC_SMS: rc = gsm0411_rcv_sms(msc_a, msg); break; case GSM48_PDISC_MM_GPRS: case GSM48_PDISC_SM_GPRS: LOG_MSC_A_CAT(msc_a, DRLL, LOGL_NOTICE, "Unimplemented " "GSM 04.08 discriminator 0x%02x\n", pdisc); rc = -ENOTSUP; break; case GSM48_PDISC_NC_SS: rc = gsm0911_rcv_nc_ss(msc_a, msg); break; case GSM48_PDISC_TEST: rc = gsm0414_rcv_test(msc_a, msg); break; default: LOG_MSC_A_CAT(msc_a, DRLL, LOGL_NOTICE, "Unknown " "GSM 04.08 discriminator 0x%02x\n", pdisc); rc = -EINVAL; break; } return rc; } static void msc_a_up_call_assignment_complete(struct msc_a *msc_a, const struct ran_msg *ac) { struct gsm_trans *cc_trans = msc_a->cc.active_trans, *gcc_trans; struct rtp_stream *rtps_to_ran = msc_a->cc.call_leg ? msc_a->cc.call_leg->rtp[RTP_TO_RAN] : NULL; const struct gsm0808_speech_codec *codec_if_known = ac->assignment_complete.codec_present ? &ac->assignment_complete.codec : NULL; /* Pending assignment has worked out. We're no longer waiting for a response now. */ osmo_timer_del(&msc_a->cc.assignment_request_pending); /* For a voice group call, handling is performed by VGCS FSM */ gcc_trans = trans_find_by_type(msc_a, TRANS_GCC); if (gcc_trans) { vgcs_vbs_caller_assign_cpl(gcc_trans); return; } gcc_trans = trans_find_by_type(msc_a, TRANS_BCC); if (gcc_trans) { vgcs_vbs_caller_assign_cpl(gcc_trans); return; } if (!rtps_to_ran) { LOG_MSC_A(msc_a, LOGL_ERROR, "Rx Assignment Complete, but no RTP stream is set up\n"); return; } if (!cc_trans) { LOG_MSC_A(msc_a, LOGL_ERROR, "Rx Assignment Complete, but no CC transaction is active\n"); return; } if (rtps_to_ran->use_osmux != ac->assignment_complete.osmux_present) { LOG_MSC_A_CAT(msc_a, DCC, LOGL_ERROR, "Osmux usage ass request and complete don't match: %d vs %d\n", rtps_to_ran->use_osmux, ac->assignment_complete.osmux_present); call_leg_release(msc_a->cc.call_leg); return; } if (codec_if_known) { const struct codec_mapping *codec_assigned; /* Check for unexpected codec with CSD */ switch (cc_trans->bearer_cap.transfer) { case GSM48_BCAP_ITCAP_FAX_G3: case GSM48_BCAP_ITCAP_3k1_AUDIO: case GSM48_BCAP_ITCAP_UNR_DIG_INF: if (codec_if_known->type == GSM0808_SCT_CSD) break; /* we're good */ LOG_TRANS(cc_trans, LOGL_ERROR, "Unexpected codec in Assignment Complete for CSD: %s\n", gsm0808_speech_codec_type_name(codec_if_known->type)); call_leg_release(msc_a->cc.call_leg); return; default: break; } /* For 2G: * - The Assignment Complete has returned a specific codec (e.g. FR3 for AMR FR). * - Set this codec at the MGW endpoint facing the RAN. * - Also set this codec at the MGW endpoint facing the CN -- we require an exact match on both call * legs. * - TODO: be aware of transcoding that the MGW is capable of, e.g. AMR octet-aligned to AMR * bandwidth-efficient... * * For 3G: * - ran_infra->force_mgw_codecs_to_ran sets VND.3GPP.IUFP as single codec at the MGW towards RAN. * - ran_msg_iu.c always returns FR3 (AMR FR) for the assigned codec. Set that at the MGW towards CN. * - So the MGW decapsulates IuUP <-> AMR */ codec_assigned = codec_mapping_by_gsm0808_speech_codec_type(codec_if_known->type); /* TODO: use codec_mapping_by_gsm0808_speech_codec() to also match on codec_if_known->cfg */ if (!codec_assigned) { LOG_TRANS(cc_trans, LOGL_ERROR, "Unknown codec in Assignment Complete: %s\n", gsm0808_speech_codec_type_name(codec_if_known->type)); call_leg_release(msc_a->cc.call_leg); return; } /* Update RAN-side endpoint CI from Assignment result -- unless it is forced by the ran_infra, in which * case it remains unchanged as passed to the earlier call of call_leg_ensure_ci(). */ if (msc_a->c.ran->force_mgw_codecs_to_ran.count == 0) rtp_stream_set_one_codec(rtps_to_ran, &codec_assigned->sdp); /* Update codec filter with Assignment result, for the CN side */ cc_trans->cc.codecs.assignment = codec_assigned->sdp; } else { /* No codec passed in Assignment Complete, set 'codecs.assignment' to none. */ cc_trans->cc.codecs.assignment = (struct sdp_audio_codec){}; LOG_TRANS(cc_trans, LOGL_INFO, "Assignment Complete without voice codec\n"); } rtp_stream_set_remote_addr(rtps_to_ran, &ac->assignment_complete.remote_rtp); if (rtps_to_ran->use_osmux) rtp_stream_set_remote_osmux_cid(rtps_to_ran, ac->assignment_complete.osmux_cid); rtp_stream_commit(rtps_to_ran); /* Remember the Codec List (BSS Supported) */ if (ac->assignment_complete.codec_list_bss_supported) codec_filter_set_bss(&cc_trans->cc.codecs, ac->assignment_complete.codec_list_bss_supported); trans_cc_filter_run(cc_trans); LOG_TRANS(cc_trans, LOGL_INFO, "Assignment Complete: RAN: %s, CN: %s\n", sdp_audio_codecs_to_str(&rtps_to_ran->codecs), sdp_audio_codecs_to_str(&cc_trans->cc.local.audio_codecs)); if (cc_on_assignment_done(cc_trans)) { /* If an error occurred, it was logged in cc_assignment_done() */ call_leg_release(msc_a->cc.call_leg); return; } } /* Invoked when Assignment has failed, either by a failure response, or by timeout. When failing on timeout, * pass af == NULL. */ static void msc_a_up_call_assignment_failure(struct msc_a *msc_a, const struct ran_msg *af) { struct gsm_trans *trans; /* Pending assignment has failed. We're no longer waiting for a response now. */ osmo_timer_del(&msc_a->cc.assignment_request_pending); /* For a normal voice call, there will be an rtp_stream FSM. */ if (msc_a->cc.call_leg && msc_a->cc.call_leg->rtp[RTP_TO_RAN]) { LOG_MSC_A(msc_a, LOGL_ERROR, "Assignment Failure, releasing call\n"); rtp_stream_release(msc_a->cc.call_leg->rtp[RTP_TO_RAN]); return; } /* For a voice group call, release is performed by VGCS FSM */ trans = trans_find_by_type(msc_a, TRANS_GCC); if (trans) { vgcs_vbs_caller_assign_fail(trans); return; } trans = trans_find_by_type(msc_a, TRANS_BCC); if (trans) { vgcs_vbs_caller_assign_fail(trans); return; } /* Otherwise, a silent call might be active */ trans = trans_find_by_type(msc_a, TRANS_SILENT_CALL); if (trans) { LOG_MSC_A(msc_a, LOGL_ERROR, "Assignment Failure, releasing silent call\n"); trans_free(trans); return; } /* Neither a voice call nor silent call assignment. Assume the worst and detach. */ msc_a_release_cn(msc_a); } static void assignment_request_timeout_cb(void *data) { struct msc_a *msc_a = data; msc_a_up_call_assignment_failure(msc_a, NULL); } static void msc_a_up_classmark_update(struct msc_a *msc_a, const struct osmo_gsm48_classmark *classmark, struct osmo_gsm48_classmark *dst) { if (!dst) { struct vlr_subscr *vsub = msc_a_vsub(msc_a); if (!vsub) dst = &msc_a->temporary_classmark; else dst = &vsub->classmark; } LOG_MSC_A(msc_a, LOGL_DEBUG, "A5 capabilities received from Classmark Update: %s\n", osmo_gsm48_classmark_a5_name(classmark)); osmo_gsm48_classmark_update(dst, classmark); /* bump subscr conn FSM in case it is waiting for a Classmark Update */ if (msc_a->c.fi->state == MSC_A_ST_WAIT_CLASSMARK_UPDATE) osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_CLASSMARK_UPDATE, NULL); } static void msc_a_up_sapi_n_reject(struct msc_a *msc_a, const struct ran_msg *msg) { int sapi = msg->sapi_n_reject.dlci & 0x7; if (sapi == UM_SAPI_SMS) gsm411_sapi_n_reject(msc_a); } static int msc_a_up_ho(struct msc_a *msc_a, const struct msc_a_ran_dec_data *d, uint32_t ho_fi_event) { if (!msc_a->ho.fi) { LOG_MSC_A(msc_a, LOGL_ERROR, "Rx Handover message, but no Handover ongoing: %s\n", d->ran_dec->msg_name); return -EINVAL; } return osmo_fsm_inst_dispatch(msc_a->ho.fi, ho_fi_event, (void*)d); } int msc_a_ran_dec_from_msc_i(struct msc_a *msc_a, struct msc_a_ran_dec_data *d) { struct vlr_subscr *vsub = msc_a_vsub(msc_a); struct gsm_network *net = msc_a_net(msc_a); const struct ran_msg *msg = d->ran_dec; int rc = -99; switch (msg->msg_type) { case RAN_MSG_COMPL_L3: /* In case the cell_id from Complete Layer 3 Information lacks a PLMN, write the configured PLMN code * into msc_a->via_cell. Then overwrite with those bits obtained from Complete Layer 3 Information. */ msc_a->via_cell = (struct osmo_cell_global_id){ .lai.plmn = msc_a_net(msc_a)->plmn, }; gsm0808_cell_id_to_cgi(&msc_a->via_cell, msg->compl_l3.cell_id); /* If a codec list was sent along in the RAN_MSG_COMPL_L3, remember it for any upcoming codec * resolution. */ if (msg->compl_l3.codec_list_bss_supported) { msc_a->cc.compl_l3_codec_list_bss_supported = *msg->compl_l3.codec_list_bss_supported; if (log_check_level(msc_a->c.ran->log_subsys, LOGL_DEBUG)) { struct sdp_audio_codecs ac = {}; sdp_audio_codecs_from_speech_codec_list(&ac, &msc_a->cc.compl_l3_codec_list_bss_supported); LOG_MSC_A(msc_a, LOGL_DEBUG, "Complete Layer 3: Codec List (BSS Supported): %s\n", sdp_audio_codecs_to_str(&ac)); } } /* Submit the Complete Layer 3 Information DTAP */ rc = msc_a_up_l3(msc_a, msg->compl_l3.msg); if (!rc) { struct ran_conn *conn = msub_ran_conn(msc_a->c.msub); if (conn) ran_peer_cells_seen_add(conn->ran_peer, msg->compl_l3.cell_id); } break; case RAN_MSG_DTAP: rc = msc_a_up_l3(msc_a, msg->dtap); break; case RAN_MSG_CLEAR_REQUEST: rc = osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_MO_CLOSE, NULL); break; case RAN_MSG_CLEAR_COMPLETE: switch (msc_a->c.fi->state) { case MSC_A_ST_RELEASING: msc_a_put_all(msc_a, MSC_A_USE_WAIT_CLEAR_COMPLETE); msc_a_state_chg(msc_a, MSC_A_ST_RELEASED); break; case MSC_A_ST_RELEASED: break; default: LOG_MSC_A(msc_a, LOGL_ERROR, "Received Clear Complete event, but did not send Clear Command\n"); msc_a_state_chg(msc_a, MSC_A_ST_RELEASING); break; } rc = 0; break; case RAN_MSG_CLASSMARK_UPDATE: msc_a_up_classmark_update(msc_a, msg->classmark_update.classmark, NULL); rc = 0; break; case RAN_MSG_CIPHER_MODE_COMPLETE: /* Remember what Ciphering was negotiated (e.g. for Handover) */ if (msg->cipher_mode_complete.alg_id) { msc_a->geran_encr.alg_id = msg->cipher_mode_complete.alg_id; LOG_MSC_A(msc_a, LOGL_DEBUG, "Cipher Mode Complete: chosen encryption algorithm: A5/%u\n", msc_a->geran_encr.alg_id - 1); } if (msc_a->c.ran->type == OSMO_RAT_UTRAN_IU) { int16_t utran_encryption; /* utran: ensure chosen ciphering mode is allowed * If the IE is missing (utran_encryption == -1), parse it as no encryption */ utran_encryption = msg->cipher_mode_complete.utran_encryption; if (utran_encryption == -1) utran_encryption = 0; if ((net->uea_encryption_mask & (1 << utran_encryption)) == 0) { /* cipher disallowed */ LOG_MSC_A(msc_a, LOGL_ERROR, "Cipher Mode Complete: RNC chosen forbidden ciphering UEA%d\n", msg->cipher_mode_complete.utran_encryption); vlr_subscr_rx_ciph_res(vsub, VLR_CIPH_REJECT); rc = 0; break; } } vlr_subscr_rx_ciph_res(vsub, VLR_CIPH_COMPL); rc = 0; /* Evaluate enclosed L3 message, typically Identity Response (IMEISV) */ if (msg->cipher_mode_complete.l3_msg) { unsigned char *data = (unsigned char*)(msg->cipher_mode_complete.l3_msg->val); uint16_t len = msg->cipher_mode_complete.l3_msg->len; struct msgb *dtap = msgb_alloc(len, "DTAP from Cipher Mode Complete"); unsigned char *pos = msgb_put(dtap, len); memcpy(pos, data, len); dtap->l3h = pos; rc = msc_a_up_l3(msc_a, dtap); msgb_free(dtap); } break; case RAN_MSG_CIPHER_MODE_REJECT: vlr_subscr_rx_ciph_res(vsub, VLR_CIPH_REJECT); rc = 0; break; case RAN_MSG_ASSIGNMENT_COMPLETE: msc_a_up_call_assignment_complete(msc_a, msg); rc = 0; break; case RAN_MSG_ASSIGNMENT_FAILURE: msc_a_up_call_assignment_failure(msc_a, msg); rc = 0; break; case RAN_MSG_SAPI_N_REJECT: msc_a_up_sapi_n_reject(msc_a, msg); rc = 0; break; case RAN_MSG_HANDOVER_PERFORMED: /* The BSS lets us know that a handover happened within the BSS, which doesn't concern us. */ LOG_MSC_A(msc_a, LOGL_ERROR, "'Handover Performed' handling not implemented\n"); break; case RAN_MSG_HANDOVER_REQUIRED: /* The BSS lets us know that it wants to handover to a different cell */ rc = osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_HANDOVER_REQUIRED, (void*)&msg->handover_required); break; case RAN_MSG_HANDOVER_FAILURE: rc = msc_a_up_ho(msc_a, d, MSC_HO_EV_RX_FAILURE); break; case RAN_MSG_LCLS_STATUS: /* The BSS sends us LCLS_STATUS. We do nothing for now, but it is not an error. */ LOG_MSC_A(msc_a, LOGL_DEBUG, "LCLS_STATUS (%s) received from MSC-I\n", gsm0808_lcls_status_name(msg->lcls_status.status)); rc = 0; break; default: LOG_MSC_A(msc_a, LOGL_ERROR, "Message from MSC-I not implemented: %s\n", ran_msg_type_name(msg->msg_type)); rc = -ENOTSUP; break; } return rc; } static int msc_a_rx_vgcs_bss_decoded(struct osmo_fsm_inst *caller_fi, void *caller_data, const struct ran_msg *msg) { struct vgcs_bss *bss = caller_data; struct msc_a *msc_a = (bss->trans) ? bss->trans->msc_a : NULL; int rc = 0; switch (msg->msg_type) { case RAN_MSG_VGCS_VBS_SETUP_ACK: /* The BSS accepts VGCS/VBS and sends us supported features. */ vgcs_vbs_setup_ack(bss, msg); break; case RAN_MSG_VGCS_VBS_SETUP_REFUSE: /* The BSS refuses VGCS/VBS. */ vgcs_vbs_setup_refuse(bss, msg); break; case RAN_MSG_UPLINK_REQUEST: /* A mobile station requests the uplink on a VGCS channel. */ vgcs_uplink_request(bss, msg); break; case RAN_MSG_UPLINK_REQUEST_CNF: /* The uplink on a VGCS channel has been established. */ vgcs_uplink_request_cnf(bss, msg); break; case RAN_MSG_UPLINK_APPLICATION_DATA: /* Application data received on the uplink of a VGCS channel. */ vgcs_app_data(bss, msg); break; case RAN_MSG_DTAP: /* BSS confirms the release of the channel. */ vgcs_bss_dtap(bss, msg); break; case RAN_MSG_UPLINK_RELEASE_IND: /* A mobile station releases the uplink on a VGCS channel. */ vgcs_uplink_release_ind(bss, msg); break; case RAN_MSG_CLEAR_REQUEST: /* BSS indicated that the channel has been released. */ vgcs_vbs_clear_req(bss, msg); break; case RAN_MSG_CLEAR_COMPLETE: /* BSS confirms the release of the channel. */ vgcs_vbs_clear_cpl(bss, msg); break; default: LOG_MSC_A(msc_a, LOGL_ERROR, "VGCS message from BSS not implemented: %s\n", ran_msg_type_name(msg->msg_type)); rc = -ENOTSUP; break; } return rc; } int msc_a_rx_vgcs_bss(struct vgcs_bss *bss, struct ran_conn *from_conn, struct msgb *msg) { struct ran_dec ran_dec; /* Feed through the decoding mechanism ran_msg. The decoded message arrives in msc_a_rx_vgcs_decoded() */ ran_dec = (struct ran_dec) { .caller_data = bss, .decode_cb = msc_a_rx_vgcs_bss_decoded, }; struct ran_peer *ran_peer = from_conn->ran_peer; struct ran_infra *ran = ran_peer->sri->ran; if (!ran->ran_dec_l2) { LOGP(DMSC, LOGL_ERROR, "No ran_dec_l2() defined for RAN type %s\n", osmo_rat_type_name(ran->type)); return -ENOTSUP; } return ran->ran_dec_l2(&ran_dec, msg); } static int msc_a_rx_vgcs_cell_decoded(struct osmo_fsm_inst *caller_fi, void *caller_data, const struct ran_msg *msg) { struct vgcs_bss_cell *cell = caller_data; struct msc_a *msc_a = (cell->bss && cell->bss->trans) ? cell->bss->trans->msc_a : NULL; int rc = 0; switch (msg->msg_type) { case RAN_MSG_VGCS_VBS_ASSIGN_RES: /* The BSS accepts VGCS/VBS channel assignment. */ vgcs_vbs_assign_result(cell, msg); break; case RAN_MSG_VGCS_VBS_ASSIGN_FAIL: /* The BSS refuses VGCS/VBS channel assignment. */ vgcs_vbs_assign_fail(cell, msg); break; case RAN_MSG_VGCS_VBS_QUEUING_IND: /* The BSS needs more time for VGCS/VBS channel assignment. */ vgcs_vbs_queuing_ind(cell); break; case RAN_MSG_VGCS_VBS_ASSIGN_STATUS: /* The BSS gives cell status about VGCS/VBS channel. */ vgcs_vbs_assign_status(cell, msg); break; case RAN_MSG_CLEAR_REQUEST: /* BSS indicated that the channel has been released. */ vgcs_vbs_clear_req_channel(cell, msg); break; case RAN_MSG_CLEAR_COMPLETE: /* BSS confirms the release of the channel. */ vgcs_vbs_clear_cpl_channel(cell, msg); break; default: LOG_MSC_A(msc_a, LOGL_ERROR, "Message from BSS leg not implemented: %s\n", ran_msg_type_name(msg->msg_type)); rc = -ENOTSUP; break; } return rc; } int msc_a_rx_vgcs_cell(struct vgcs_bss_cell *cell, struct ran_conn *from_conn, struct msgb *msg) { struct ran_dec ran_dec; /* Feed through the decoding mechanism ran_msg. The decoded message arrives in msc_a_rx_vgcs_decoded() */ ran_dec = (struct ran_dec) { .caller_data = cell, .decode_cb = msc_a_rx_vgcs_cell_decoded, }; struct ran_peer *ran_peer = from_conn->ran_peer; struct ran_infra *ran = ran_peer->sri->ran; if (!ran->ran_dec_l2) { LOGP(DMSC, LOGL_ERROR, "No ran_dec_l2() defined for RAN type %s\n", osmo_rat_type_name(ran->type)); return -ENOTSUP; } return ran->ran_dec_l2(&ran_dec, msg); } static int msc_a_ran_dec_from_msc_t(struct msc_a *msc_a, struct msc_a_ran_dec_data *d) { struct msc_t *msc_t = msc_a_msc_t(msc_a); int rc = -99; if (!msc_t) { LOG_MSC_A(msc_a, LOGL_ERROR, "Rx message from MSC-T role, but I have no active MSC-T role.\n"); return -EINVAL; } OSMO_ASSERT(d->ran_dec); switch (d->ran_dec->msg_type) { case RAN_MSG_CLEAR_REQUEST: rc = osmo_fsm_inst_dispatch(msc_t->c.fi, MSC_T_EV_MO_CLOSE, NULL); break; case RAN_MSG_CLEAR_COMPLETE: rc = osmo_fsm_inst_dispatch(msc_t->c.fi, MSC_T_EV_CLEAR_COMPLETE, NULL); break; case RAN_MSG_CLASSMARK_UPDATE: msc_a_up_classmark_update(msc_a, d->ran_dec->classmark_update.classmark, &msc_t->classmark); rc = 0; break; case RAN_MSG_HANDOVER_REQUEST_ACK: /* new BSS accepts Handover */ rc = msc_a_up_ho(msc_a, d, MSC_HO_EV_RX_REQUEST_ACK); break; case RAN_MSG_HANDOVER_DETECT: /* new BSS signals the MS is DETECTed on the new lchan */ rc = msc_a_up_ho(msc_a, d, MSC_HO_EV_RX_DETECT); break; case RAN_MSG_HANDOVER_COMPLETE: /* new BSS signals the MS has fully moved to the new lchan */ rc = msc_a_up_ho(msc_a, d, MSC_HO_EV_RX_COMPLETE); break; case RAN_MSG_HANDOVER_FAILURE: rc = msc_a_up_ho(msc_a, d, MSC_HO_EV_RX_FAILURE); break; default: LOG_MSC_A(msc_a, LOGL_ERROR, "Message from MSC-T not implemented: %s\n", ran_msg_type_name(d->ran_dec->msg_type)); rc = -ENOTSUP; break; } return rc; } int msc_a_ran_decode_cb(struct osmo_fsm_inst *msc_a_fi, void *data, const struct ran_msg *msg) { struct msc_a *msc_a = msc_a_fi_priv(msc_a_fi); struct msc_a_ran_dec_data *d = data; int rc = -99; d->ran_dec = msg; switch (d->from_role) { case MSC_ROLE_I: LOG_MSC_A(msc_a, LOGL_DEBUG, "RAN decode: %s\n", msg->msg_name ? : ran_msg_type_name(msg->msg_type)); rc = msc_a_ran_dec_from_msc_i(msc_a, d); break; case MSC_ROLE_T: LOG_MSC_A(msc_a, LOGL_DEBUG, "RAN decode from MSC-T: %s\n", msg->msg_name ? : ran_msg_type_name(msg->msg_type)); rc = msc_a_ran_dec_from_msc_t(msc_a, d); break; default: LOG_MSC_A(msc_a, LOGL_ERROR, "Message from invalid role %s: %s\n", msc_role_name(d->from_role), ran_msg_type_name(msg->msg_type)); return -ENOTSUP; } if (rc) LOG_MSC_A(msc_a, LOGL_ERROR, "RAN decode error (rc=%d) for %s from %s\n", rc, ran_msg_type_name(msg->msg_type), msc_role_name(d->from_role)); return rc; } /* Your typical DTAP via FORWARD_ACCESS_SIGNALLING_REQUEST */ int _msc_a_ran_down(struct msc_a *msc_a, enum msc_role to_role, const struct ran_msg *ran_msg, const char *file, int line) { return _msc_a_msg_down(msc_a, to_role, msub_role_to_role_event(msc_a->c.msub, MSC_ROLE_A, to_role), ran_msg, file, line); } /* To transmit more complex events than just FORWARD_ACCESS_SIGNALLING_REQUEST, e.g. an * MSC_T_EV_FROM_A_PREPARE_HANDOVER_REQUEST */ int _msc_a_msg_down(struct msc_a *msc_a, enum msc_role to_role, uint32_t to_role_event, const struct ran_msg *ran_msg, const char *file, int line) { struct an_apdu an_apdu = { .an_proto = msc_a->c.ran->an_proto, .msg = msc_role_ran_encode(msc_a->c.fi, ran_msg), }; if (!an_apdu.msg) return -EIO; return _msub_role_dispatch(msc_a->c.msub, to_role, to_role_event, &an_apdu, file, line); } int msc_a_tx_dtap_to_i(struct msc_a *msc_a, struct msgb *dtap) { struct ran_msg ran_msg; struct gsm48_hdr *gh = msgb_l3(dtap) ? : dtap->data; uint8_t pdisc = gsm48_hdr_pdisc(gh); if (!msc_a) { LOGP(DMSC, LOGL_ERROR, "Attempt to send DTAP to NULL MSC-A, dropping message: %s %s\n", gsm48_pdisc_name(pdisc), gsm48_pdisc_msgtype_name(pdisc, gsm48_hdr_msg_type(gh))); msgb_free(dtap); return -EIO; } if (msc_a->c.ran->type == OSMO_RAT_EUTRAN_SGS) { /* The SGs connection to the MME always is at the MSC-A. */ return sgs_iface_tx_dtap_ud(msc_a, dtap); } LOG_MSC_A(msc_a, 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 = dtap, }; return msc_a_ran_down(msc_a, MSC_ROLE_I, &ran_msg); } struct msc_a *msc_a_for_vsub(const struct vlr_subscr *vsub, bool valid_conn_only) { struct msc_a *msc_a = msub_msc_a(msub_for_vsub(vsub)); if (valid_conn_only && !msc_a_is_accepted(msc_a)) return NULL; return msc_a; } int msc_tx_common_id(struct msc_a *msc_a, enum msc_role to_role) { struct vlr_subscr *vsub = msc_a_vsub(msc_a); if (vsub == NULL) return -ENODEV; struct ran_msg msg = { .msg_type = RAN_MSG_COMMON_ID, .common_id = { .imsi = vsub->imsi, .last_eutran_plmn_present = vsub->sgs.last_eutran_plmn_present, }, }; if (vsub->sgs.last_eutran_plmn_present) { memcpy(&msg.common_id.last_eutran_plmn, &vsub->sgs.last_eutran_plmn, sizeof(vsub->sgs.last_eutran_plmn)); } return msc_a_ran_down(msc_a, to_role, &msg); } static int msc_a_start_assignment(struct msc_a *msc_a, struct gsm_trans *cc_trans) { struct call_leg *cl; bool cn_rtp_available; bool ran_rtp_available; OSMO_ASSERT(!msc_a->cc.active_trans); msc_a->cc.active_trans = cc_trans; cc_trans->cc.codecs.assignment = (struct sdp_audio_codec){}; OSMO_ASSERT(cc_trans && cc_trans->type == TRANS_CC); cl = msc_a_ensure_call_leg(msc_a, cc_trans); if (!cl) return -EINVAL; /* See if we can set a preliminary codec. If not, pass none for the time being. */ trans_cc_filter_run(cc_trans); cn_rtp_available = call_leg_local_ip(cl, RTP_TO_CN); ran_rtp_available = call_leg_local_ip(cl, RTP_TO_RAN); /* Set up RTP ports for both RAN and CN side. Even though we ask for both at the same time, the * osmo_mgcpc_ep_fsm automagically waits for the first CRCX to complete before firing the second CRCX. The one * issued first here will also be the first CRCX sent to the MGW. Usually both still need to be set up. */ if (!cn_rtp_available) call_leg_ensure_ci(cl, RTP_TO_CN, cc_trans->call_id, cc_trans, &cc_trans->cc.local.audio_codecs, NULL); if (!ran_rtp_available) { struct sdp_audio_codecs *codecs; if (msc_a->c.ran->force_mgw_codecs_to_ran.count) codecs = &msc_a->c.ran->force_mgw_codecs_to_ran; else codecs = &cc_trans->cc.local.audio_codecs; return call_leg_ensure_ci(cl, RTP_TO_RAN, cc_trans->call_id, cc_trans, codecs, NULL); } /* Should these already be set up, immediately continue by retriggering the events signalling that the RTP * ports are available. The ordering is: first CN, then RAN. */ if (cn_rtp_available && ran_rtp_available) return osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE, cl->rtp[RTP_TO_RAN]); else if (cn_rtp_available) return osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE, cl->rtp[RTP_TO_CN]); /* Otherwise wait for MGCP response and continue from there. */ return 0; } int msc_a_try_call_assignment(struct gsm_trans *cc_trans) { struct msc_a *msc_a = cc_trans->msc_a; OSMO_ASSERT(cc_trans->type == TRANS_CC); if (msc_a->cc.active_trans == cc_trans) { LOG_MSC_A(msc_a, LOGL_DEBUG, "Assignment for this trans already started earlier\n"); return 0; } if (msc_a->cc.active_trans) { LOG_MSC_A(msc_a, LOGL_INFO, "Another call is already ongoing, not assigning yet\n"); return 0; } LOG_MSC_A(msc_a, LOGL_DEBUG, "Starting call assignment\n"); return msc_a_start_assignment(msc_a, cc_trans); } /* Map CM Service type to use token. * Given a CM Service type, return a matching token intended for osmo_use_count. * For unknown service type, return NULL. */ const char *msc_a_cm_service_type_to_use(struct msc_a *msc_a, enum osmo_cm_service_type cm_service_type) { struct gsm_network *net = msc_a_net(msc_a); switch (cm_service_type) { case GSM48_CMSERV_MO_CALL_PACKET: case GSM48_CMSERV_EMERGENCY: return MSC_A_USE_CM_SERVICE_CC; case GSM48_CMSERV_SMS: return MSC_A_USE_CM_SERVICE_SMS; case GSM48_CMSERV_SUP_SERV: return MSC_A_USE_CM_SERVICE_SS; case GSM48_CMSERV_VGCS: if (net->asci.enable) return MSC_A_USE_CM_SERVICE_GCC; else return NULL; case GSM48_CMSERV_VBS: if (net->asci.enable) return MSC_A_USE_CM_SERVICE_BCC; else return NULL; default: return NULL; } } void msc_a_release_cn(struct msc_a *msc_a) { osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_CN_CLOSE, NULL); } void msc_a_release_mo(struct msc_a *msc_a, enum gsm48_gsm_cause gsm_cause) { osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_MO_CLOSE, NULL); }