/* SGs Interface according to 3GPP TS 23.272 + TS 29.118 */ /* (C) 2018-2019 by sysmocom s.f.m.c. GmbH * All Rights Reserved * * Author: Harald Welte, Philipp Maier * * 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 #define S(x) (1 << (x)) /* A pointer to the GSM network we work with. By the current paradigm, * there can only be one gsm_network per MSC. The pointer is set once * when calling sgs_iface_init() */ static struct gsm_network *gsm_network = NULL; static struct osmo_fsm sgs_vlr_reset_fsm; static void sgs_tx(struct sgs_connection *sgc, struct msgb *msg); struct sgs_state *g_sgs; /*********************************************************************** * SGs state per MME connection ***********************************************************************/ #define LOGSGC(sgc, lvl, fmt, args...) \ LOGP(DSGS, lvl, "%s: " fmt, sgc->sockname, ## args) #define LOGSGC_VSUB(sgc, sub_info, lvl, fmt, args...) \ LOGP(DSGS, lvl, "(sub %s) %s: " fmt, sub_info, sgc->sockname, ## args) #define LOGMME(mme, lvl, fmt, args...) \ LOGP(DSGS, lvl, "%s: " fmt, mme->fqdn ? mme->fqdn : mme->conn->sockname, ## args) enum sgs_vlr_reset_fsm_state { SGS_VLRR_ST_NULL, SGS_VLRR_ST_WAIT_ACK, SGS_VLRR_ST_COMPLETE, }; enum sgs_vlr_reset_fsm_event { SGS_VLRR_E_START_RESET, SGS_VLRR_E_RX_RESET_ACK, }; /*********************************************************************** * SGs utility functions ***********************************************************************/ /* Allocate a new subscriber connection */ static struct msc_a *subscr_conn_allocate_sgs(struct sgs_connection *sgc, struct vlr_subscr *vsub, bool mt) { struct msub *msub; struct msc_a *msc_a; msub = msub_alloc(gsm_network); msc_a = msc_a_alloc(msub, &msc_ran_infra[OSMO_RAT_EUTRAN_SGS]); msc_a->complete_layer3_type = mt ? COMPLETE_LAYER3_PAGING_RESP : COMPLETE_LAYER3_CM_SERVICE_REQ; msub_set_vsub(msub, vsub); if (mt) msc_a_get(msc_a, MSC_A_USE_PAGING_RESPONSE); /* Accept the connection immediately, since the UE is already * authenticated by the MME no authentication is required. */ osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_COMPLETE_LAYER_3_OK, NULL); osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_AUTHENTICATED, NULL); return msc_a; } /* Check if there are connections associated with a given subscriber. If yes, * make sure that those connections are tossed. */ static void subscr_conn_toss(struct vlr_subscr *vsub) { struct msub *msub; msub = msub_for_vsub(vsub); if (!msub) return; LOG_MSUB(msub, LOGL_ERROR, "Force releasing previous subscriber connection: an SGs connection for this" " subscriber is being initiated\n"); msc_a_release_mo(msub_msc_a(msub), GSM_CAUSE_AUTH_FAILED); /* TODO: is this strong enough? After this, it should be completely disassociated with this subscriber. */ } struct sgs_mme_ctx *sgs_mme_by_fqdn(struct sgs_state *sgs, const char *mme_fqdn) { struct sgs_mme_ctx *mme; llist_for_each_entry(mme, &sgs->mme_list, entry) { if (!strcasecmp(mme_fqdn, mme->fqdn)) return mme; } return NULL; } static struct sgs_mme_ctx *sgs_mme_alloc(struct sgs_state *sgs, const char *mme_fqdn, const struct osmo_gummei *gummei) { struct sgs_mme_ctx *mme; OSMO_ASSERT(sgs_mme_by_fqdn(sgs, mme_fqdn) == NULL); mme = talloc_zero(sgs, struct sgs_mme_ctx); if (!mme) return NULL; mme->sgs = sgs; OSMO_STRLCPY_ARRAY(mme->fqdn, mme_fqdn); mme->fi = osmo_fsm_inst_alloc(&sgs_vlr_reset_fsm, mme, mme, LOGL_INFO, osmo_gummei_name(gummei)); if (!mme->fi) { talloc_free(mme); return NULL; } llist_add_tail(&mme->entry, &sgs->mme_list); return mme; } /* Decode and verify MME name */ static int decode_mme_name(char *mme_name, const struct tlv_parsed *tp) { const uint8_t *mme_name_enc = TLVP_VAL_MINLEN(tp, SGSAP_IE_MME_NAME, SGS_MME_NAME_LEN); struct osmo_gummei gummei; if (!mme_name_enc) return -EINVAL; /* some implementations use FDQN format violating TS 29.118 9.3.14 */ if (!osmo_parse_mme_domain(&gummei, (const char *) mme_name_enc)) { memcpy(mme_name, mme_name_enc, TLVP_LEN(tp, SGSAP_IE_MME_NAME)); return 0; } /* decode the MME name from DNS labels to string */ osmo_apn_to_str(mme_name, TLVP_VAL(tp, SGSAP_IE_MME_NAME), TLVP_LEN(tp, SGSAP_IE_MME_NAME)); /* try to parse the MME name into a GUMMEI as a test for the format */ if (osmo_parse_mme_domain(&gummei, mme_name) < 0) return -EINVAL; return 0; } /* A MME FQDN was received (e.g. RESET-IND/RESET-ACK/LU-REQ) */ static int sgs_mme_fqdn_received(struct sgs_connection *sgc, const char *mme_fqdn) { struct sgs_mme_ctx *mme; struct osmo_gummei gummei; /* caller must pass in a valid FQDN string syntax */ OSMO_ASSERT(osmo_parse_mme_domain(&gummei, mme_fqdn) == 0); if (!sgc->mme) { /* attempt to find MME with given name */ mme = sgs_mme_by_fqdn(sgc->sgs, mme_fqdn); if (!mme) mme = sgs_mme_alloc(sgc->sgs, mme_fqdn, &gummei); OSMO_ASSERT(mme); if (mme->conn) { /* The MME context has another connection !?! */ LOGSGC(sgc, LOGL_ERROR, "Rx MME name %s, but that MME already has other " "SCTP connection?!?\n", mme_fqdn); return -1; } else { /* associate the two */ mme->conn = sgc; sgc->mme = mme; } } else { mme = sgc->mme; if (strcasecmp(mme->fqdn, mme_fqdn) != 0) { LOGMME(mme, LOGL_ERROR, "Rx MME name \"%s\" in packet from MME \"%s\" ?!?\n", mme_fqdn, mme->fqdn); return -2; } } return 0; } /* Safely get the mme-name for an sgs-connection */ static char *sgs_mme_fqdn_get(struct sgs_connection *sgc) { if (!sgc) return NULL; if (!sgc->mme) return NULL; if (sgc->mme->fqdn[0] == '\0') return NULL; return sgc->mme->fqdn; } /* Find an sgs_mme_ctx for a given vlr subscriber, also check result */ struct sgs_mme_ctx *sgs_mme_ctx_by_vsub(struct vlr_subscr *vsub, uint8_t msg_type) { struct sgs_mme_ctx *mme; /* Find SGS connection by MME name */ mme = sgs_mme_by_fqdn(g_sgs, vsub->sgs.mme_name); if (!mme) { LOGP(DSGS, LOGL_ERROR, "(sub %s) Tx %s cannot find suitable MME!\n", vlr_subscr_name(vsub), sgsap_msg_type_name(msg_type)); return NULL; } if (!mme->conn) { LOGP(DSGS, LOGL_ERROR, "(sub %s) Tx %s suitable MME found, but no SGS connection present!\n", vlr_subscr_name(vsub), sgsap_msg_type_name(msg_type)); return NULL; } if (!mme->sgs) { LOGP(DSGS, LOGL_ERROR, "(sub %s) Tx %s suitable MME found, but no SGS state present!\n", vlr_subscr_name(vsub), sgsap_msg_type_name(msg_type)); return NULL; } return mme; } /* Make sure that the subscriber is known and that the subscriber is in the * SGs associated state. In case of failure the function returns false and * automatically sends a release message to the MME */ static bool check_sgs_association(struct sgs_connection *sgc, struct msgb *msg, char *imsi) { struct vlr_subscr *vsub; struct msgb *resp; uint8_t msg_type = msg->data[0]; /* Subscriber must be known by the VLR */ vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi, __func__); if (!vsub) { LOGSGC(sgc, LOGL_NOTICE, "SGsAP Message %s with unknown IMSI (%s), releasing\n", sgsap_msg_type_name(msg_type), imsi); resp = gsm29118_create_release_req(imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN); sgs_tx(sgc, resp); return false; } /* The SGs FSM must also be in SGs associated state */ if (vsub->sgs_fsm->state != SGS_UE_ST_ASSOCIATED) { LOGSGC(sgc, LOGL_NOTICE, "(sub %s) SGsAP Message %s subscriber not SGs-associated, releasing\n", vlr_subscr_name(vsub), sgsap_msg_type_name(msg_type)); resp = gsm29118_create_release_req(vsub->imsi, SGSAP_SGS_CAUSE_IMSI_DET_EPS_NONEPS); sgs_tx(sgc, resp); vlr_subscr_put(vsub, __func__); return false; } vlr_subscr_put(vsub, __func__); return true; } /*********************************************************************** * SGsAP transmit functions ***********************************************************************/ /* Send message out to remote end (final step) */ static void sgs_tx(struct sgs_connection *sgc, struct msgb *msg) { if (!msg) { LOGSGC(sgc, LOGL_NOTICE, "Null message, cannot transmit!\n"); return; } msgb_sctp_ppid(msg) = 0; if (!sgc) { LOGP(LOGL_NOTICE, DSGS, "Cannot transmit %s: connection dead. Discarding\n", sgsap_msg_type_name(msg->data[0])); msgb_free(msg); return; } osmo_stream_srv_send(sgc->srv, msg); } /* Get some subscriber info from ISMI (for the log text) */ const char *subscr_info(const char *imsi) { const char *subscr_string = ""; struct vlr_subscr *vsub; if (imsi) { vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi, __func__); if (!vsub) subscr_string = imsi; else { subscr_string = vlr_subscr_name(vsub); vlr_subscr_put(vsub, __func__); } } return subscr_string; } /* Comfortable status message generator that also generates some basic * context-dependent log output */ static int sgs_tx_status(struct sgs_connection *sgc, const char *imsi, enum sgsap_sgs_cause cause, struct msgb *msg, int sgsap_iei) { struct msgb *resp; if (sgsap_iei < 0) { LOGSGC_VSUB(sgc, subscr_info(imsi), LOGL_ERROR, "Rx %s failed with cause %s!\n", sgsap_msg_type_name(msg->data[0]), sgsap_sgs_cause_name(cause)); } else if (cause == SGSAP_SGS_CAUSE_MISSING_MAND_IE) { LOGSGC_VSUB(sgc, subscr_info(imsi), LOGL_ERROR, "Rx %s with missing mandatory %s IEI!\n", sgsap_msg_type_name(msg->data[0]), sgsap_iei_name(sgsap_iei)); } else if (cause == SGSAP_SGS_CAUSE_INVALID_MAND_IE) { LOGSGC_VSUB(sgc, subscr_info(imsi), LOGL_ERROR, "Rx %s with invalid mandatory %s IEI!\n", sgsap_msg_type_name(msg->data[0]), sgsap_iei_name(sgsap_iei)); } else if (cause == SGSAP_SGS_CAUSE_COND_IE_ERROR) { LOGSGC_VSUB(sgc, subscr_info(imsi), LOGL_ERROR, "Rx %s with erroneous conditional %s IEI!\n", sgsap_msg_type_name(msg->data[0]), sgsap_iei_name(sgsap_iei)); } else { LOGSGC_VSUB(sgc, subscr_info(imsi), LOGL_ERROR, "Rx %s failed with cause %s at %s IEI!\n", sgsap_msg_type_name(msg->data[0]), sgsap_sgs_cause_name(cause), sgsap_iei_name(sgsap_iei)); } resp = gsm29118_create_status(imsi, cause, msg); sgs_tx(sgc, resp); return 0; } /* Called by VLR via callback, transmits the location update response or * reject, depending on the outcome of the location update. */ static void sgs_tx_loc_upd_resp_cb(struct sgs_lu_response *response) { struct msgb *resp; struct vlr_subscr *vsub = response->vsub; struct sgs_mme_ctx *mme; uint8_t new_id[2 + GSM48_TMSI_LEN]; uint8_t *new_id_ptr = NULL; int new_id_len = 0; uint8_t resp_msg_type; /* Determine message type that is sent next (needed for logging) */ if (response->accepted) resp_msg_type = SGSAP_MSGT_LOC_UPD_ACK; else if (response->error) resp_msg_type = SGSAP_MSGT_RESET_IND; else resp_msg_type = SGSAP_MSGT_LOC_UPD_REJ; /* Determine MME */ mme = sgs_mme_ctx_by_vsub(vsub, resp_msg_type); if (!mme) return; /* Handle error (HLR failure) */ if (response->error) { osmo_fsm_inst_dispatch(mme->fi, SGS_VLRR_E_START_RESET, NULL); return; } /* Handle LU accept/reject */ if (response->accepted) { if (vsub->tmsi_new != GSM_RESERVED_TMSI) { struct osmo_mobile_identity tmsi_mi = { .type = GSM_MI_TYPE_TMSI, .tmsi = vsub->tmsi_new, }; new_id_len = osmo_mobile_identity_encode_buf(new_id, sizeof(new_id), &tmsi_mi, false); if (new_id_len > 0) { new_id_ptr = new_id; } else { /* Failure to encode the TMSI is not actually possible here, this is just for paranoia * and coverity scan. */ new_id_len = 0; LOGPFSMSL(vsub->sgs_fsm, DMM, LOGL_ERROR, "Cannot encode TMSI Mobile Identity\n"); } } resp = gsm29118_create_lu_ack(vsub->imsi, &vsub->sgs.lai, new_id_ptr, new_id_len); sgs_tx(mme->conn, resp); vlr_sgs_loc_update_acc_sent(vsub); } else { resp = gsm29118_create_lu_rej(vsub->imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN, &vsub->sgs.lai); sgs_tx(mme->conn, resp); vlr_sgs_loc_update_rej_sent(vsub); } } /* Called by VLR via callback, transmits MM information to the UE */ static void sgs_tx_mm_info_cb(struct vlr_subscr *vsub) { struct msgb *msg; struct msgb *msg_mm_info; struct sgs_mme_ctx *mme; /* The sending of MM information requests is an optional feature and * depends on the network configuration (VTY) */ if (!gsm_network->send_mm_info) return; mme = sgs_mme_ctx_by_vsub(vsub, SGSAP_MSGT_MM_INFO_REQ); if (!mme) return; /* Create and send MM information request message, see also: * 3GPP TS 29.118, chapter 8.12 SGsAP-MM-INFORMATION-REQUEST and * 3GPP TS 29.018, chapter 18.4.16 MM information. */ msg_mm_info = gsm48_create_mm_info(gsm_network); msg = gsm29118_create_mm_info_req(vsub->imsi, msg_mm_info->data + 2, msg_mm_info->len - 2); sgs_tx(mme->conn, msg); msgb_free(msg_mm_info); } enum sgsap_service_ind sgs_serv_ind_from_paging_cause(enum paging_cause cause) { switch (cause) { case PAGING_CAUSE_CALL_CONVERSATIONAL: case PAGING_CAUSE_CALL_STREAMING: case PAGING_CAUSE_CALL_INTERACTIVE: case PAGING_CAUSE_CALL_BACKGROUND: return SGSAP_SERV_IND_CS_CALL; case PAGING_CAUSE_UNSPECIFIED: case PAGING_CAUSE_SIGNALLING_LOW_PRIO: case PAGING_CAUSE_SIGNALLING_HIGH_PRIO: return SGSAP_SERV_IND_SMS; default: OSMO_ASSERT(false); } } /*! Page UE through SGs interface or inform about an expired paging * \param[in] vsub subscriber context * \param[in] serv_ind service indicator (sms or voide) * \returns 0 in case of success, -EINVAL in case of error. */ int sgs_iface_paging_cb(struct vlr_subscr *vsub, enum sgsap_service_ind serv_ind) { struct msgb *resp; struct gsm29118_paging_req paging_params; struct sgs_mme_ctx *mme; if (serv_ind == SGSAP_SERV_IND_PAGING_TIMEOUT) { paging_expired(vsub); return 0; } /* See also: 3GPP TS 29.118, chapter 5.1.2.2 Paging Initiation */ if (vsub->sgs_fsm->state == SGS_UE_ST_NULL && vsub->conf_by_radio_contact_ind == true) { LOGPFSMSL(vsub->sgs_fsm, DPAG, LOGL_ERROR, "Will not Page (conf_by_radio_contact_ind == true)\n"); return -EINVAL; } mme = sgs_mme_ctx_by_vsub(vsub, SGSAP_MSGT_PAGING_REQ); if (!mme) { LOGPFSMSL(vsub->sgs_fsm, DPAG, LOGL_ERROR, "Will not Page (no MME)\n"); return -EINVAL; } /* Check if there is still a paging in progress for this subscriber, * if yes, don't initiate another paging request. */ if (vlr_sgs_pag_pend(vsub)) return 0; LOGMME(mme, LOGL_INFO, "Paging on SGs: %s for %s (conf_by_radio_contact_ind=%d)\n", vlr_subscr_name(vsub), sgsap_service_ind_name(serv_ind), vsub->conf_by_radio_contact_ind); memset(&paging_params, 0, sizeof(paging_params)); osmo_strlcpy(paging_params.imsi, vsub->imsi, sizeof(paging_params.imsi)); osmo_strlcpy(paging_params.vlr_name, mme->sgs->cfg.vlr_name, sizeof(paging_params.vlr_name)); paging_params.serv_ind = serv_ind; if (vsub->conf_by_radio_contact_ind == true) { memcpy(&paging_params.lai, &vsub->sgs.lai, sizeof(paging_params.lai)); paging_params.lai_present = true; } resp = gsm29118_create_paging_req(&paging_params); sgs_tx(mme->conn, resp); /* FIXME: If we are in SGS_UE_ST_NULL while sub->conf_by_radio_contact_ind == false, * we are supposed to start a search procedure as defined in 3GPP TS 23.018 */ /* Inform the VLR that a paging via SGs is in progress */ vlr_sgs_pag(vsub, serv_ind); /* Return a page count of 1 (success) */ return 1; } /*********************************************************************** * SGs incoming messages from the MME ***********************************************************************/ /* Safely read out the SGs cause code from a given message/tlv set, send status * message in case the cause code is invalid or missing. */ static int sgs_cause_from_msg(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, const char *imsi) { enum sgsap_sgs_cause cause; const uint8_t *cause_ptr; cause_ptr = TLVP_VAL_MINLEN(tp, SGSAP_IE_SGS_CAUSE, 1); if (!cause_ptr) { sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_SGS_CAUSE); return -1; } else cause = *cause_ptr; return cause; } /* SGsAP-STATUS 3GPP TS 29.118, chapter 8.18 */ static int sgs_rx_status(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, const char *imsi) { int cause; const uint8_t *err_msg; const char *imsi_ptr; char *err_msg_hex = "(none)"; cause = sgs_cause_from_msg(sgc, msg, tp, NULL); if (cause < 0) return 0; if (imsi[0] != '\0') imsi_ptr = imsi; else imsi_ptr = ""; if (TLVP_PRESENT(tp, SGSAP_IE_ERR_MSG)) err_msg = TLVP_VAL(tp, SGSAP_IE_ERR_MSG); else err_msg = NULL; if (err_msg) err_msg_hex = osmo_hexdump(err_msg, TLVP_LEN(tp, SGSAP_IE_ERR_MSG)); LOGSGC(sgc, LOGL_NOTICE, "Rx STATUS cause=%s, IMSI=%s, err_msg=%s\n", sgsap_sgs_cause_name(cause), imsi_ptr, err_msg_hex); return 0; } /* SGsAP-RESET-INDICATION 3GPP TS 29.118, chapter 8.16 */ static int sgs_rx_reset_ind(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp) { struct gsm29118_reset_msg reset_params; struct msgb *resp; memset(&reset_params, 0, sizeof(reset_params)); osmo_strlcpy(reset_params.vlr_name, sgc->sgs->cfg.vlr_name, sizeof(reset_params.vlr_name)); reset_params.vlr_name_present = true; resp = gsm29118_create_reset_ack(&reset_params); /* Perform a reset of the SGS FSM of all subscribers that are present in the VLR */ vlr_sgs_reset(gsm_network->vlr); sgs_tx(sgc, resp); return 0; } /* SGsAP-RESET-ACK 3GPP TS 29.118, chapter 8.15 */ static int sgs_rx_reset_ack(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp) { /* dispatch event to VLR reset FSM for this MME */ if (sgc->mme && sgc->mme->fi) osmo_fsm_inst_dispatch(sgc->mme->fi, SGS_VLRR_E_RX_RESET_ACK, msg); return 0; } /* SGsAP-LOCATION-UPDATE-REQUEST 3GPP TS 29.118, chapter 8.11 */ static int sgs_rx_loc_upd_req(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) { struct msgb *resp; const uint8_t *lu_type_ie; enum vlr_lu_type type; struct osmo_location_area_id new_lai; const struct gsm48_loc_area_id *gsm48_lai; int rc; char *mme_name; struct vlr_sgs_cfg vlr_sgs_cfg; struct vlr_subscr *vsub; struct osmo_plmn_id last_eutran_plmn_buf, *last_eutran_plmn = NULL; /* Check for lingering connections */ vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi, __func__); if (vsub) { subscr_conn_toss(vsub); vlr_subscr_put(vsub, __func__); vsub = NULL; } /* Determine MME-Name */ mme_name = sgs_mme_fqdn_get(sgc); if (!mme_name) { resp = gsm29118_create_lu_rej(imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN, NULL); sgs_tx(sgc, resp); return 0; } /* Parse LU-Type */ lu_type_ie = TLVP_VAL_MINLEN(tp, SGSAP_IE_EPS_LU_TYPE, 1); if (!lu_type_ie) return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_EPS_LU_TYPE); if (lu_type_ie[0] == 0x01) type = VLR_LU_TYPE_IMSI_ATTACH; else type = VLR_LU_TYPE_REGULAR; /* Parse LAI of the new location */ gsm48_lai = (struct gsm48_loc_area_id *)TLVP_VAL_MINLEN(tp, SGSAP_IE_LAI, 5); if (!gsm48_lai) return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_LAI); gsm48_decode_lai2(gsm48_lai, &new_lai); /* 3GPP TS 23.272 sec 4.3.3 (CSFB): * "During the SGs location update procedure, obtaining the last used LTE PLMN ID via TAI" */ if (TLVP_PRES_LEN(tp, SGSAP_IE_TAI, 3)) { last_eutran_plmn = &last_eutran_plmn_buf; osmo_plmn_from_bcd(TLVP_VAL(tp, SGSAP_IE_TAI), last_eutran_plmn); /* TODO: we could also gather the TAC from here, but we don't need it yet */ } else if (TLVP_PRES_LEN(tp, SGSAP_IE_EUTRAN_CGI, 3)) { /* Since TAI is optional, let's try harder getting Last Used * E-UTRAN PLMN ID by fetching it from E-UTRAN CGI */ last_eutran_plmn = &last_eutran_plmn_buf; osmo_plmn_from_bcd(TLVP_VAL(tp, SGSAP_IE_EUTRAN_CGI), last_eutran_plmn); /* TODO: we could also gather the ECI from here, but we don't need it yet */ } else { LOGSGC(sgc, LOGL_INFO, "Receiving SGsAP-LOCATION-UPDATE-REQUEST without TAI nor " "E-CGI IEs, fast fallback GERAN->EUTRAN won't be possible!\n"); } /* Perform actual location update */ memcpy(vlr_sgs_cfg.timer, sgc->sgs->cfg.timer, sizeof(vlr_sgs_cfg.timer)); memcpy(vlr_sgs_cfg.counter, sgc->sgs->cfg.counter, sizeof(vlr_sgs_cfg.counter)); rc = vlr_sgs_loc_update(gsm_network->vlr, &vlr_sgs_cfg, sgs_tx_loc_upd_resp_cb, sgs_iface_paging_cb, sgs_tx_mm_info_cb, mme_name, type, imsi, &new_lai, last_eutran_plmn); if (rc != 0) { resp = gsm29118_create_lu_rej(imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN, NULL); sgs_tx(sgc, resp); } return 0; } /* SGsAP-IMSI-DETACH-INDICATION 3GPP TS 29.118, chapter 8.8 */ static int sgs_rx_imsi_det_ind(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) { struct msgb *resp; enum sgsap_imsi_det_noneps_type type; const uint8_t *type_ie; type_ie = TLVP_VAL_MINLEN(tp, SGSAP_IE_IMSI_DET_NONEPS_TYPE, 1); if (!type_ie) return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_IMSI_DET_NONEPS_TYPE); switch (type_ie[0]) { case SGSAP_ID_NONEPS_T_EXPLICIT_UE_NONEPS: type = SGSAP_ID_NONEPS_T_EXPLICIT_UE_NONEPS; break; case SGSAP_ID_NONEPS_T_COMBINED_UE_EPS_NONEPS: type = SGSAP_ID_NONEPS_T_COMBINED_UE_EPS_NONEPS; break; case SGSAP_ID_NONEPS_T_IMPLICIT_UE_EPS_NONEPS: type = SGSAP_ID_NONEPS_T_IMPLICIT_UE_EPS_NONEPS; break; default: return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_INVALID_MAND_IE, msg, SGSAP_IE_IMSI_DET_NONEPS_TYPE); break; } vlr_sgs_imsi_detach(gsm_network->vlr, imsi, type); resp = gsm29118_create_imsi_det_ack(imsi); sgs_tx(sgc, resp); return 0; } /* SGsAP-EPS-DETACH-INDICATION 3GPP TS 29.118, chapter 8.6 */ static int sgs_rx_eps_det_ind(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) { struct msgb *resp; enum sgsap_imsi_det_eps_type type; const uint8_t *type_ie; type_ie = TLVP_VAL_MINLEN(tp, SGSAP_IE_IMSI_DET_EPS_TYPE, 1); if (!type_ie) return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_IMSI_DET_EPS_TYPE); switch (type_ie[0]) { case SGSAP_ID_EPS_T_NETWORK_INITIATED: type = SGSAP_ID_EPS_T_NETWORK_INITIATED; break; case SGSAP_ID_EPS_T_UE_INITIATED: type = SGSAP_ID_EPS_T_UE_INITIATED; break; case SGSAP_ID_EPS_T_EPS_NOT_ALLOWED: type = SGSAP_ID_EPS_T_EPS_NOT_ALLOWED; break; default: return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_INVALID_MAND_IE, msg, SGSAP_IE_IMSI_DET_EPS_TYPE); break; } vlr_sgs_eps_detach(gsm_network->vlr, imsi, type); resp = gsm29118_create_eps_det_ack(imsi); sgs_tx(sgc, resp); return 0; } /* SGsAP-PAGING-REJECT 3GPP TS 29.118, chapter 8.13 */ static int sgs_rx_pag_rej(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) { int cause; struct vlr_subscr *vsub; cause = sgs_cause_from_msg(sgc, msg, tp, NULL); if (cause < 0) return 0; /* Subscriber must be known by the VLR */ vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi, __func__); if (!vsub) return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN, msg, SGSAP_IE_IMSI); /* Inform the VLR */ vlr_sgs_pag_rej(gsm_network->vlr, imsi, cause); /* Stop all paging activity */ paging_expired(vsub); /* Depending on the cause code some action is required */ if (cause == SGSAP_SGS_CAUSE_MT_CSFB_REJ_USER) { /* FIXME: We are supposed to trigger a User Determined User Busy (UDUB) * as specified in 3GPP TS 24.082 here, SGs association state shall not * be changed */ LOGSGC(sgc, LOGL_ERROR, "Rx %s with SGSAP_SGS_CAUSE_MT_CSFB_REJ_USER, but sending UDUP is not implemented yet!\n", sgsap_msg_type_name(msg->data[0])); } else if (cause == SGSAP_SGS_CAUSE_IMSI_DET_EPS) { /* FIXME: In this case we should send the paging via A/Iu interface */ OSMO_ASSERT(false); } vlr_subscr_put(vsub, __func__); return 0; } /* SGsAP-UE-UNREACHABLE 3GPP TS 29.118, chapter 8.21 */ static int sgs_rx_ue_unr(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) { int cause; cause = sgs_cause_from_msg(sgc, msg, tp, NULL); if (cause < 0) return 0; vlr_sgs_ue_unr(gsm_network->vlr, imsi, cause); return 0; } /* SGsAP-TMSI-REALLOCATION-COMPLETE 3GPP TS 29.118, chapter 8.19 */ static int sgs_rx_tmsi_reall_cmpl(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) { vlr_sgs_tmsi_reall_compl(gsm_network->vlr, imsi); return 0; } /* SGsAP-SERVICE-REQUEST 3GPP TS 29.118, chapter 8.17 */ static int sgs_rx_service_req(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) { enum sgsap_service_ind serv_ind; const uint8_t *serv_ind_ie; struct msc_a *msc_a; struct vlr_subscr *vsub; /* Note: While in other RAN concepts a service request is used to * initiate mobile originated operation, the service request in SGsAP * is comparable to a paging response. The SGsAP SERVICE REQUEST must * not be confused or compared with a CM SERVICE REQUEST! */ if (!check_sgs_association(sgc, msg, imsi)) return 0; vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi, __func__); /* Note: vsub is already sufficiently verified by check_sgs_association(), * we must have a vsub at this point! */ OSMO_ASSERT(vsub); /* The Service request is intended as a paging response, if one is * received while nothing is paging something is very wrong! */ if (!vlr_sgs_pag_pend(vsub)) { vlr_subscr_put(vsub, __func__); return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MSG_INCOMP_STATE, msg, -1); } serv_ind_ie = TLVP_VAL_MINLEN(tp, SGSAP_IE_SERVICE_INDICATOR, 1); if (!serv_ind_ie) { vlr_subscr_put(vsub, __func__); return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_SERVICE_INDICATOR); } if (serv_ind_ie[0] == SGSAP_SERV_IND_CS_CALL) serv_ind = serv_ind_ie[0]; else if (serv_ind_ie[0] == SGSAP_SERV_IND_SMS) serv_ind = serv_ind_ie[0]; else { vlr_subscr_put(vsub, __func__); return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_INVALID_MAND_IE, msg, SGSAP_IE_SERVICE_INDICATOR); } /* FIXME: The MME shall include an UE EMM Mode IE, but the field is * marked optional. (Why do we need this info at all?) */ /* Report to the VLR that the paging has successfully completed */ vlr_sgs_pag_ack(gsm_network->vlr, imsi); /* Exit early when the service indicator indicates that a call is being * established. In those cases we do not allocate a connection, instead * the connection will be allocated when the MS is appearing on the * A-Interface. */ if (serv_ind == SGSAP_SERV_IND_CS_CALL) { vlr_subscr_put(vsub, __func__); return 0; } /* Allocate subscriber connection */ msc_a = subscr_conn_allocate_sgs(sgc, vsub, true); if (!msc_a) { vlr_subscr_put(vsub, __func__); return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MSG_INCOMP_STATE, msg, -1); } /* The msub has added a get() for the vsub, balance above vlr_subscr_find_by_imsi() */ vlr_subscr_put(vsub, __func__); return 0; } /* SGsAP-UPLINK-UNITDATA 3GPP TS 29.118, chapter 8.22 */ static int sgs_rx_ul_ud(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) { struct msc_a *msc_a; const uint8_t *nas_msg_container_ie; struct vlr_subscr *vsub; if (!check_sgs_association(sgc, msg, imsi)) return 0; vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi, __func__); /* Note: vsub is already sufficiently verified by check_sgs_association(), * we must have a vsub at this point! */ OSMO_ASSERT(vsub); /* Try to find existing connection (MT) or allocate a new one (MO) */ msc_a = msc_a_for_vsub(vsub, true); if (!msc_a) msc_a = subscr_conn_allocate_sgs(sgc, vsub, false); /* Balance above vlr_subscr_find_by_imsi() */ vlr_subscr_put(vsub, __func__); /* If we do not find an existing connection and allocating a new one * failed, give up and return status. */ if (!msc_a) return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MSG_INCOMP_STATE, msg, 0); if (msc_a->c.ran->type != OSMO_RAT_EUTRAN_SGS) { LOGSGC(sgc, LOGL_ERROR, "Receiving uplink unit-data for non-sgs connection -- discarding message!\n"); return -EINVAL; } nas_msg_container_ie = TLVP_VAL_MINLEN(tp, SGSAP_IE_NAS_MSG_CONTAINER, 1); if (!nas_msg_container_ie) return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_NAS_MSG_CONTAINER); /* ran_conn_dtap expects the dtap payload in l3h */ msg->l3h = (uint8_t *)nas_msg_container_ie; msc_a_up_l3(msc_a, msg); return 0; } /* SGsAP-MO-CSFB-INDICATION, chapter 8.25 */ static int sgs_rx_csfb_ind(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) { struct vlr_subscr *vsub; struct osmo_plmn_id last_eutran_plmn_buf; const struct osmo_plmn_id *last_eutran_plmn = &last_eutran_plmn_buf; /* The MME informs us with this message that the UE has initiated a * service request for MO CS fallback. There is not much we can do with * this information, however, we can check if the subscriber actually * exists in the VLR and if there are any lingering connections open.*/ vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi, __func__); if (!vsub) return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN, msg, SGSAP_IE_IMSI); /* 3GPP TS 23.272 sec 4.3.3 (CSFB): * "During the SGs location update procedure, obtaining the last used LTE PLMN ID via TAI" */ if (TLVP_PRES_LEN(tp, SGSAP_IE_TAI, 3)) { osmo_plmn_from_bcd(TLVP_VAL(tp, SGSAP_IE_TAI), &last_eutran_plmn_buf); /* TODO: we could also gather the TAC from here, but we don't need it yet */ } else if (TLVP_PRES_LEN(tp, SGSAP_IE_EUTRAN_CGI, 3)) { /* Since TAI is optional, let's try harder getting Last Used * E-UTRAN PLMN ID by fetching it from E-UTRAN CGI */ osmo_plmn_from_bcd(TLVP_VAL(tp, SGSAP_IE_EUTRAN_CGI), &last_eutran_plmn_buf); /* TODO: we could also gather the ECI from here, but we don't need it yet */ } else { LOGSGC(sgc, LOGL_INFO, "Receiving SGsAP-MO-CSFB-INDICATION without TAI nor " "E-CGI IEs, and they are not known from previous SGsAP-LOCATION-UPDATE-REQUEST. " "Fast fallback GERAN->EUTRAN won't be possible!\n"); last_eutran_plmn = NULL; } vlr_subscr_set_last_used_eutran_plmn_id(vsub, last_eutran_plmn); /* Check for lingering connections */ subscr_conn_toss(vsub); vlr_subscr_put(vsub, __func__); return 0; } /* SGsAP-UE-ACTIVITY-INDICATION, chapter 8.20 */ static int sgs_rx_ue_act_ind(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) { /* In this MSC/VLR implementation we do not support the alerting * procedure yet and therefore we will never request any alerting * at the MME. Given that it is unlikely that we ever get activity * indications from the MME, but if we do we should not act all too * hostile and ignore the indication silently. */ LOGSGC(sgc, LOGL_ERROR, "Rx %s unexpected, we do not implement alerting yet, ignoring!\n", sgsap_msg_type_name(msg->data[0])); return 0; } #define TX_STATUS_AND_LOG(sgc, msg_type, cause, fmt) \ LOGSGC(sgc, LOGL_ERROR, fmt, sgsap_msg_type_name(msg_type)); \ resp = gsm29118_create_status(NULL, cause, msg); \ sgs_tx(sgc, resp); \ /*! Process incoming SGs message (see sgs_server.c) * \param[in] sgc related sgs connection * \param[in] msg received message * \returns 0 in case of success, -EINVAL in case of error. */ int sgs_iface_rx(struct sgs_connection *sgc, struct msgb *msg) { struct msgb *resp; uint8_t msg_type = msg->l2h[0]; struct tlv_parsed tp; int rc; char imsi[GSM48_MI_SIZE]; char mme_name[SGS_MME_NAME_LEN + 1]; memset(imsi, 0, sizeof(imsi)); memset(mme_name, 0, sizeof(mme_name)); /* When the receiving entity receives a message that is too short to contain a complete * message type information element, the receiving entity shall ignore that message. */ if (msgb_l2len(msg) < 1) goto error; /* Parse TLV elements */ rc = tlv_parse(&tp, &sgsap_ie_tlvdef, msgb_l2(msg) + 1, msgb_l2len(msg) - 1, 0, 0); if (rc < 0) LOGSGC(sgc, LOGL_NOTICE, "SGsAP Message %s contains unknown TLV IEs\n", sgsap_msg_type_name(msg_type)); /* Most of the messages contain an IMSI as mandatory IE, parse it right here */ if (!TLVP_PRESENT(&tp, SGSAP_IE_IMSI) && msg_type != SGSAP_MSGT_STATUS && msg_type != SGSAP_MSGT_RESET_IND && msg_type != SGSAP_MSGT_RESET_ACK) { /* reject the message; all but the three above have mandatory IMSI */ TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_MISSING_MAND_IE, "SGsAP Message %s without IMSI, dropping\n"); goto error; } if (TLVP_PRESENT(&tp, SGSAP_IE_IMSI)) { struct osmo_mobile_identity mi; if (osmo_mobile_identity_decode(&mi, TLVP_VAL(&tp, SGSAP_IE_IMSI), TLVP_LEN(&tp, SGSAP_IE_IMSI), false) || mi.type != GSM_MI_TYPE_IMSI) { TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_INVALID_MAND_IE, "SGsAP Message %s with invalid IMSI, dropping\n"); goto error; } OSMO_STRLCPY_ARRAY(imsi, mi.imsi); } /* Some messages contain an MME-NAME as mandatory IE, parse it right here. The * MME-NAME is also immediately registered with the sgc, so it will be implicitly * known to all functions that have access to the sgc context. */ if (!TLVP_PRESENT(&tp, SGSAP_IE_MME_NAME) && (msg_type == SGSAP_MSGT_RESET_IND || msg_type == SGSAP_MSGT_RESET_ACK || msg_type == SGSAP_MSGT_LOC_UPD_REQ || msg_type == SGSAP_MSGT_IMSI_DET_IND || msg_type == SGSAP_MSGT_EPS_DET_IND)) { TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_MISSING_MAND_IE, "SGsAP Message %s without MME-Name, dropping\n"); goto error; } if (TLVP_PRESENT(&tp, SGSAP_IE_MME_NAME)) { if (decode_mme_name(mme_name, &tp) != 0) { TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_INVALID_MAND_IE, "SGsAP Message %s with invalid MME-Name, dropping\n"); goto error; } /* Regsister/check mme_name with sgc */ if (sgs_mme_fqdn_received(sgc, mme_name) < 0) { TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_MSG_INCOMP_STATE, "SGsAP Message %s with invalid MME-Name, dropping\n"); goto error; } } /* dispatch msg to various handler functions. msgb ownership remains here! */ rc = -EINVAL; switch (msg_type) { case SGSAP_MSGT_STATUS: rc = sgs_rx_status(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_RESET_IND: rc = sgs_rx_reset_ind(sgc, msg, &tp); break; case SGSAP_MSGT_RESET_ACK: rc = sgs_rx_reset_ack(sgc, msg, &tp); break; case SGSAP_MSGT_LOC_UPD_REQ: rc = sgs_rx_loc_upd_req(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_IMSI_DET_IND: rc = sgs_rx_imsi_det_ind(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_EPS_DET_IND: rc = sgs_rx_eps_det_ind(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_PAGING_REJ: rc = sgs_rx_pag_rej(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_UE_UNREACHABLE: rc = sgs_rx_ue_unr(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_TMSI_REALL_CMPL: rc = sgs_rx_tmsi_reall_cmpl(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_SERVICE_REQ: rc = sgs_rx_service_req(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_UL_UD: rc = sgs_rx_ul_ud(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_MO_CSFB_IND: rc = sgs_rx_csfb_ind(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_UE_ACT_IND: rc = sgs_rx_ue_act_ind(sgc, msg, &tp, imsi); break; case SGSAP_MSGT_ALERT_ACK: case SGSAP_MSGT_ALERT_REJ: LOGSGC(sgc, LOGL_ERROR, "Rx unmplemented SGsAP %s: %s\n", sgsap_msg_type_name(msg_type), msgb_hexdump(msg)); resp = gsm29118_create_status(imsi, SGSAP_SGS_CAUSE_MSG_UNKNOWN, msg); sgs_tx(sgc, resp); rc = 0; break; default: LOGSGC(sgc, LOGL_ERROR, "Rx unknown SGsAP message type 0x%02x: %s\n", msg_type, msgb_hexdump(msg)); resp = gsm29118_create_status(imsi, SGSAP_SGS_CAUSE_MSG_UNKNOWN, msg); sgs_tx(sgc, resp); rc = 0; break; } /* Catch unhandled errors */ if (rc < 0) { /* Note: Usually the sgs_rx_ should catch errors locally and * eimit a status message with proper cause code, including * a suitable log message. If we end up here, something is * not right and should be fixed */ LOGSGC(sgc, LOGL_ERROR, "Rx unable to decode SGsAP %s: %s\n", sgsap_msg_type_name(msg_type), msgb_hexdump(msg)); resp = gsm29118_create_status(imsi, SGSAP_SGS_CAUSE_MSG_UNKNOWN, msg); sgs_tx(sgc, resp); } error: msgb_free(msg); return 0; } /*********************************************************************** * SGs connection "VLR Reset Procedure" FSM ***********************************************************************/ static const struct value_string sgs_vlr_reset_fsm_event_names[] = { {SGS_VLRR_E_START_RESET, "START-RESET"}, {SGS_VLRR_E_RX_RESET_ACK, "RX-RESET-ACK"}, {0, NULL} }; static void sgs_vlr_reset_fsm_null(struct osmo_fsm_inst *fi, uint32_t event, void *data) { switch (event) { case SGS_VLRR_E_RX_RESET_ACK: break; default: OSMO_ASSERT(0); break; } } static void sgs_vlr_reset_fsm_wait_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data) { switch (event) { case SGS_VLRR_E_RX_RESET_ACK: osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_COMPLETE, 0, 0); break; default: OSMO_ASSERT(0); break; } } static void sgs_vlr_reset_fsm_complete(struct osmo_fsm_inst *fi, uint32_t event, void *data) { switch (event) { case SGS_VLRR_E_RX_RESET_ACK: break; default: OSMO_ASSERT(0); break; } } static void sgs_vlr_reset_fsm_allstate(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct msgb *reset_ind; struct gsm29118_reset_msg reset_params; struct sgs_mme_ctx *mme = (struct sgs_mme_ctx *)fi->priv; struct sgs_connection *sgc = mme->conn; struct sgs_state *sgs = mme->sgs; switch (event) { case SGS_VLRR_E_START_RESET: osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_NULL, 0, 0); mme->ns11_remaining = sgs->cfg.counter[SGS_STATE_NS11]; /* send a reset message and enter WAIT_ACK state */ memset(&reset_params, 0, sizeof(reset_params)); osmo_strlcpy(reset_params.vlr_name, sgs->cfg.vlr_name, sizeof(reset_params.vlr_name)); reset_params.vlr_name_present = true; reset_ind = gsm29118_create_reset_ind(&reset_params); sgs_tx(sgc, reset_ind); /* Perform a reset of the SGS FSM of all subscribers that are present in the VLR */ vlr_sgs_reset(gsm_network->vlr); osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_WAIT_ACK, sgs->cfg.timer[SGS_STATE_TS11], 11); break; default: OSMO_ASSERT(0); break; } } static int sgs_vlr_reset_fsm_timer_cb(struct osmo_fsm_inst *fi) { struct msgb *reset_ind; struct gsm29118_reset_msg reset_params; struct sgs_mme_ctx *mme = (struct sgs_mme_ctx *)fi->priv; struct sgs_connection *sgc = mme->conn; struct sgs_state *sgs = mme->sgs; switch (fi->T) { case 11: if (mme->ns11_remaining >= 1) { memset(&reset_params, 0, sizeof(reset_params)); osmo_strlcpy(reset_params.vlr_name, sgs->cfg.vlr_name, sizeof(reset_params.vlr_name)); reset_params.vlr_name_present = true; reset_ind = gsm29118_create_reset_ind(&reset_params); sgs_tx(sgc, reset_ind); osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_WAIT_ACK, sgs->cfg.timer[SGS_STATE_TS11], 11); mme->ns11_remaining--; } else { LOGMME(mme, LOGL_ERROR, "Ts11 expired more than %u (Ns11) times, giving up\n", sgs->cfg.counter[SGS_STATE_NS11]); osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_NULL, 0, 0); } break; default: OSMO_ASSERT(0); break; } return 0; } static const struct osmo_fsm_state sgs_vlr_reset_fsm_states[] = { [SGS_VLRR_ST_NULL] = { /* We haven't even tried yet to send a RESET */ .name = "NULL", .action = sgs_vlr_reset_fsm_null, .in_event_mask = S(SGS_VLRR_E_RX_RESET_ACK), .out_state_mask = S(SGS_VLRR_ST_NULL) | S(SGS_VLRR_ST_WAIT_ACK), }, [SGS_VLRR_ST_WAIT_ACK] = { /* We're waiting for a SGsAP_RESET_ACK */ .name = "WAIT-ACK", .action = sgs_vlr_reset_fsm_wait_ack, .in_event_mask = S(SGS_VLRR_E_RX_RESET_ACK), .out_state_mask = S(SGS_VLRR_ST_NULL) | S(SGS_VLRR_ST_COMPLETE) | S(SGS_VLRR_ST_WAIT_ACK), }, [SGS_VLRR_ST_COMPLETE] = { /* Reset procedure to this MME has been completed */ .name = "COMPLETE", .action = sgs_vlr_reset_fsm_complete, .in_event_mask = S(SGS_VLRR_E_RX_RESET_ACK), .out_state_mask = S(SGS_VLRR_ST_NULL) | S(SGS_VLRR_ST_COMPLETE), }, }; static struct osmo_fsm sgs_vlr_reset_fsm = { .name = "SGs-VLR-RESET", .states = sgs_vlr_reset_fsm_states, .num_states = ARRAY_SIZE(sgs_vlr_reset_fsm_states), .allstate_event_mask = S(SGS_VLRR_E_START_RESET), .allstate_action = sgs_vlr_reset_fsm_allstate, .timer_cb = sgs_vlr_reset_fsm_timer_cb, .log_subsys = DSGS, .event_names = sgs_vlr_reset_fsm_event_names, }; /*! Send unit-data through SGs interface (see msc_ifaces.c) * \param[in] msg layer 3 message to send. * \returns 0 in case of success, -EINVAL in case of error. */ int sgs_iface_tx_dtap_ud(struct msc_a *msc_a, struct msgb *msg) { struct msgb *msg_sgs; struct sgs_mme_ctx *mme; int rc = -EINVAL; struct vlr_subscr *vsub = msc_a_vsub(msc_a); OSMO_ASSERT(vsub); mme = sgs_mme_ctx_by_vsub(vsub, SGSAP_MSGT_DL_UD); if (!mme) goto error; /* Make sure the subscriber has a valid SGs association, otherwise * don't let unit-data through. */ if (vsub->sgs_fsm->state != SGS_UE_ST_ASSOCIATED) { LOG_MSC_A(msc_a, LOGL_NOTICE, "Cannot Tx %s: subscriber not SGs-associated\n", sgsap_msg_type_name(SGSAP_MSGT_DL_UD)); goto error; } msg_sgs = gsm29118_create_dl_ud(vsub->imsi, msg); sgs_tx(mme->conn, msg_sgs); rc = 0; error: msgb_free(msg); return rc; } void sgs_iface_tx_release(struct vlr_subscr *vsub) { struct msgb *msg_sgs; struct sgs_mme_ctx *mme; OSMO_ASSERT(vsub); mme = sgs_mme_ctx_by_vsub(vsub, SGSAP_MSGT_DL_UD); if (!mme) return; msg_sgs = gsm29118_create_release_req(vsub->imsi, 0); sgs_tx(mme->conn, msg_sgs); } /*! Send SGsAP-SERVICE-ABORT-REQUEST message to MME * \param[in] vsub subscriber context */ void sgs_iface_tx_serv_abrt(struct vlr_subscr *vsub) { struct msgb *msg_sgs; struct sgs_mme_ctx *mme; OSMO_ASSERT(vsub); /* The service abort procedure is only defined for MT calls, * see also 3GPP TS 29.118, chapter 5.13.2 */ if (vsub->sgs.paging_serv_ind != SGSAP_SERV_IND_CS_CALL) return; mme = sgs_mme_ctx_by_vsub(vsub, SGSAP_MSGT_DL_UD); if (!mme) return; msg_sgs = gsm29118_create_service_abort_req(vsub->imsi); sgs_tx(mme->conn, msg_sgs); } /*! initialize SGs new interface * \param[in] ctx talloc context * \param[in] network associated gsm network * \returns returns allocated sgs_stae, NULL in case of error. */ struct sgs_state *sgs_iface_init(void *ctx, struct gsm_network *network) { struct sgs_state *sgs; gsm_network = network; sgs = sgs_server_alloc(ctx); OSMO_ASSERT(sgs); /* We currently only support one SGs instance */ if (g_sgs) return NULL; g_sgs = sgs; return sgs; } static __attribute__((constructor)) void on_dso_load(void) { OSMO_ASSERT(osmo_fsm_register(&sgs_vlr_reset_fsm) == 0); }