/* (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 "vlr_sgs_fsm.h" const struct value_string sgs_state_timer_names[] = { {SGS_STATE_TS5, "Ts5"}, {SGS_STATE_TS6_2, "Ts6-2"}, {SGS_STATE_TS7, "Ts7"}, {SGS_STATE_TS11, "Ts11"}, {SGS_STATE_TS14, "Ts14"}, {SGS_STATE_TS15, "Ts15"}, {0, NULL} }; const struct value_string sgs_state_counter_names[] = { {SGS_STATE_NS7, "Ns7"}, {SGS_STATE_NS11, "Ns11"}, {0, NULL} }; /* Reset all SGs-Associations back to zero. * \param[in] vlr VLR instance. */ void vlr_sgs_reset(struct vlr_instance *vlr) { struct vlr_subscr *vsub; OSMO_ASSERT(vlr); LOGP(DVLR, LOGL_INFO, "dropping all SGs associations.\n"); llist_for_each_entry(vsub, &vlr->subscribers, list) { osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_RX_RESET_FROM_MME, NULL); } } /*! Perform an SGs location update. * \param[in] vlr VLR instance. * \param[in] cfg SGs interface configuration parameters. * \param[in] response_cb callback function that is called when LU is done. * \param[in] paging_cb callback function that is called when LU needs to page. * \param[in] mminfo_cb callback function that is called to provide MM info to the UE. * \param[in] mme_name fqdn of the requesting MME (mme-name). * \param[in] type location update type (normal or IMSI attach). * \param[in] imsi mobile identity (IMSI). * \param[in] new_lai identifier of the new location area. * \param[in] last_eutran_plnm_id Last E-UTRAN PLMN ID (can be NULL). * \returns 0 in case of success, -EINVAL in case of error. */ int vlr_sgs_loc_update(struct vlr_instance *vlr, struct vlr_sgs_cfg *cfg, vlr_sgs_lu_response_cb_t response_cb, vlr_sgs_lu_paging_cb_t paging_cb, vlr_sgs_lu_mminfo_cb_t mminfo_cb, char *mme_name, enum vlr_lu_type type, const char *imsi, struct osmo_location_area_id *new_lai, struct osmo_plmn_id *last_eutran_plmn) { struct vlr_subscr *vsub = NULL; OSMO_ASSERT(response_cb); OSMO_ASSERT(paging_cb); OSMO_ASSERT(mminfo_cb); OSMO_ASSERT(cfg); OSMO_ASSERT(imsi); vsub = vlr_subscr_find_or_create_by_imsi(vlr, imsi, VSUB_USE_SGS_LU, NULL); if (!vsub) { LOGP(DSGS, LOGL_ERROR, "VLR subscriber allocation failed\n"); return -EINVAL; } vsub->sgs.cfg = *cfg; vsub->sgs.response_cb = response_cb; vsub->sgs.paging_cb = paging_cb; vsub->sgs.mminfo_cb = mminfo_cb; vlr_subscr_set_imsi(vsub, imsi); vlr_subscr_set_last_used_eutran_plmn_id(vsub, last_eutran_plmn); osmo_strlcpy(vsub->sgs.mme_name, mme_name, sizeof(vsub->sgs.mme_name)); osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_RX_LU_FROM_MME, NULL); /* FIXME: Use the "type" type parameter (for what is it useful?) */ vsub->sgs.lai = *new_lai; vsub->cgi.lai = *new_lai; vsub->cs.lac = vsub->sgs.lai.lac; /* Subscribers that are created by the SGs location update will not * expire automatically, however a 2G LU or an implicit IMSI detach * from EPS services may change this. */ vsub->expire_lu = VLR_SUBSCRIBER_NO_EXPIRATION; return 0; } /*! Notify that the SGs Location Update accept message has been sent to MME. * \param[in] vsub VLR subscriber. */ void vlr_sgs_loc_update_acc_sent(struct vlr_subscr *vsub) { osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_TX_LU_ACCEPT, NULL); /* Balance vlr_subscr_find_or_create_by_imsi() in vlr_sgs_loc_update() */ vlr_subscr_put(vsub, VSUB_USE_SGS_LU); /* FIXME: At this point we need to check the status of Ts5 and if * it is still running this means the LU has interrupted the paging, * and we need to start paging again. 3GPP TS 29.118, * chapter 5.2.3.2 */ } /*! Notify that the SGs Location Update reject message has been sent to MME. * \param[in] vsub VLR subscriber. */ void vlr_sgs_loc_update_rej_sent(struct vlr_subscr *vsub) { osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_TX_LU_REJECT, NULL); /* Balance vlr_subscr_find_or_create_by_imsi() in vlr_sgs_loc_update() */ vlr_subscr_put(vsub, VSUB_USE_SGS_LU); } /*! Perform an SGs IMSI detach. * \param[in] vsub VLR subscriber. * \param[in] imsi mobile identity (IMSI). * \param[in] type datach type. */ void vlr_sgs_imsi_detach(struct vlr_instance *vlr, const char *imsi, enum sgsap_imsi_det_noneps_type type) { struct vlr_subscr *vsub; enum sgs_ue_fsm_event evt; vsub = vlr_subscr_find_by_imsi(vlr, imsi, __func__); if (!vsub) return; /* See also: 3GPP TS 29.118, 5.6.3 Procedures in the VLR: In case of * an implicit detach, we are supposed to check if the state of the * SGs-association, and only when it is not SGs-NULL, we may proceed. */ if (vsub->sgs_fsm->state == SGS_UE_ST_NULL && type == SGSAP_ID_NONEPS_T_IMPLICIT_UE_EPS_NONEPS) { vlr_subscr_put(vsub, __func__); return; } switch (type) { case SGSAP_ID_NONEPS_T_EXPLICIT_UE_NONEPS: evt = SGS_UE_E_RX_DETACH_IND_FROM_UE; break; case SGSAP_ID_NONEPS_T_COMBINED_UE_EPS_NONEPS: case SGSAP_ID_NONEPS_T_IMPLICIT_UE_EPS_NONEPS: /* FIXME: Is that right? */ evt = SGS_UE_E_RX_DETACH_IND_FROM_MME; break; default: LOGP(DSGS, LOGL_ERROR, "(sub %s) invalid SGS IMSI detach type, detaching anyway...\n", vlr_subscr_msisdn_or_name(vsub)); evt = SGS_UE_E_RX_DETACH_IND_FROM_MME; break; } osmo_fsm_inst_dispatch(vsub->sgs_fsm, evt, NULL); /* Detaching from non EPS services essentially means that the * subscriber is detached from 2G. In any case the VLR will * get rid of the subscriber. */ vlr_subscr_expire(vsub); vlr_subscr_put(vsub, __func__); } /*! Perform an SGs EPS detach. * \param[in] vsub VLR subscriber. * \param[in] imsi mobile identity (IMSI). * \param[in] type datach type. */ void vlr_sgs_eps_detach(struct vlr_instance *vlr, const char *imsi, enum sgsap_imsi_det_eps_type type) { struct vlr_subscr *vsub; enum sgs_ue_fsm_event evt; vsub = vlr_subscr_find_by_imsi(vlr, imsi, __func__); if (!vsub) return; switch (type) { case SGSAP_ID_EPS_T_NETWORK_INITIATED: evt = SGS_UE_E_RX_DETACH_IND_FROM_MME; break; case SGSAP_ID_EPS_T_UE_INITIATED: evt = SGS_UE_E_RX_DETACH_IND_FROM_UE; break; case SGSAP_ID_EPS_T_EPS_NOT_ALLOWED: evt = SGS_UE_E_RX_DETACH_IND_FROM_MME; break; default: LOGP(DSGS, LOGL_ERROR, "(sub %s) invalid SGS IMSI detach type, detaching anyway...\n", vlr_subscr_msisdn_or_name(vsub)); evt = SGS_UE_E_RX_DETACH_IND_FROM_MME; break; } osmo_fsm_inst_dispatch(vsub->sgs_fsm, evt, NULL); /* See also 3GPP TS 29.118, 5.4.3 Procedures in the VLR. Detaching from * EPS services essentially means that the subscriber leaves the 4G RAN * but continues to live on 2G, this basically turns the subscriber into * a normal 2G subscriber and we need to make sure that the lu- * expiration timer is running. */ if (vsub->expire_lu == VLR_SUBSCRIBER_NO_EXPIRATION) vlr_subscr_enable_expire_lu(vsub); vlr_subscr_put(vsub, __func__); } /*! Perform an SGs TMSI reallocation complete. * \param[in] vsub VLR subscriber. * \param[in] imsi mobile identity (IMSI). */ void vlr_sgs_tmsi_reall_compl(struct vlr_instance *vlr, const char *imsi) { struct vlr_subscr *vsub; vsub = vlr_subscr_find_by_imsi(vlr, imsi, __func__); if (!vsub) return; osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_RX_TMSI_REALLOC, NULL); vlr_subscr_put(vsub, __func__); } /*! Notify that an SGs paging has been rejected by the MME. * \param[in] vsub VLR subscriber. * \param[in] imsi mobile identity (IMSI). * \param[in] cause SGs cause code. */ void vlr_sgs_pag_rej(struct vlr_instance *vlr, const char *imsi, enum sgsap_sgs_cause cause) { struct vlr_subscr *vsub; vsub = vlr_subscr_find_by_imsi(vlr, imsi, __func__); if (!vsub) return; /* On the reception of a paging rej the VLR is supposed to stop Ts5, also 3GPP TS 29.118, chapter 5.1.2.4 */ osmo_timer_del(&vsub->sgs.Ts5); LOGP(DSGS, LOGL_DEBUG, "(sub %s) Paging via SGs interface rejected by MME, %s stopped, cause: %s!\n", vlr_subscr_msisdn_or_name(vsub), vlr_sgs_state_timer_name(SGS_STATE_TS5), sgsap_sgs_cause_name(cause)); osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_RX_PAGING_FAILURE, &cause); /* Balance ref count increment from vlr_sgs_pag() */ vlr_subscr_put(vsub, VSUB_USE_SGS_PAGING_REQ); vlr_subscr_put(vsub, __func__); } /*! Notify that an SGs paging has been accepted by the MME. * \param[in] vsub VLR subscriber. * \param[in] imsi mobile identity (IMSI). */ void vlr_sgs_pag_ack(struct vlr_instance *vlr, const char *imsi) { struct vlr_subscr *vsub; vsub = vlr_subscr_find_by_imsi(vlr, imsi, __func__); if (!vsub) return; /* Stop Ts5 and and consider the paging as successful */ osmo_timer_del(&vsub->sgs.Ts5); /* Balance ref count increment from vlr_sgs_pag() */ vlr_subscr_put(vsub, VSUB_USE_SGS_PAGING_REQ); vlr_subscr_put(vsub, __func__); } /*! Notify that the UE has been marked as unreachable by the MME. * \param[in] vsub VLR subscriber. * \param[in] imsi mobile identity (IMSI). * \param[in] cause SGs cause code. */ void vlr_sgs_ue_unr(struct vlr_instance *vlr, const char *imsi, enum sgsap_sgs_cause cause) { struct vlr_subscr *vsub; vsub = vlr_subscr_find_by_imsi(vlr, imsi, __func__); if (!vsub) return; /* On the reception of an UE unreachable the VLR is supposed to stop * Ts5, also 3GPP TS 29.118, chapter 5.1.2.5 */ osmo_timer_del(&vsub->sgs.Ts5); LOGP(DSGS, LOGL_DEBUG, "(sub %s) Paging via SGs interface not possible, UE unreachable, %s stopped, cause: %s\n", vlr_subscr_msisdn_or_name(vsub), vlr_sgs_state_timer_name(SGS_STATE_TS5), sgsap_sgs_cause_name(cause)); osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_RX_SGSAP_UE_UNREACHABLE, &cause); vlr_subscr_put(vsub, __func__); } /* Callback function that is called when an SGs paging request times out */ static void Ts5_timeout_cb(void *arg) { struct vlr_subscr *vsub = arg; /* 3GPP TS 29.118 does not specify a specific action that has to happen * in case Ts5 times out. The timeout just indicates that the paging * failed. Other actions may check the status of Ts5 to see if a paging * is still ongoing or not. */ LOGP(DSGS, LOGL_ERROR, "(sub %s) Paging via SGs interface timed out (%s expired)!\n", vlr_subscr_msisdn_or_name(vsub), vlr_sgs_state_timer_name(SGS_STATE_TS5)); /* Balance ref count increment from vlr_sgs_pag() */ vlr_subscr_put(vsub, VSUB_USE_SGS_PAGING_REQ); return; } /*! Notify that a paging message has been sent and a paging is now in progress. * \param[in] vsub VLR subscriber. */ void vlr_sgs_pag(struct vlr_subscr *vsub, enum sgsap_service_ind serv_ind) { /* In cases where we have to respawn a paging after an intermitted LU, * there may e a Ts5 still running. In those cases we have to remove * the old timer first */ if (osmo_timer_pending(&vsub->sgs.Ts5)) osmo_timer_del(&vsub->sgs.Ts5); /* Note: 3GPP TS 29.118, chapter 4.2.2 mentions paging in the FSM * diagram, but paging never causes a state transition except when * an explicit failure is indicated (MME actively rejects paging). * Apparently it is also possible that an LU happens while the paging * is still ongoing and Ts5 is running. (chapter 5.1.2.3). This means * that the paging procedure is intended to run in parallel to the * SGs FSM and given that the benaviour around Ts5 must be implemented * also separately, to emphasize this separation Ts5 is implemented * here in and not in vlr_sgs_fsm.c. */ osmo_timer_setup(&vsub->sgs.Ts5, Ts5_timeout_cb, vsub); osmo_timer_schedule(&vsub->sgs.Ts5, vsub->sgs.cfg.timer[SGS_STATE_TS5], 0); /* Formally 3GPP TS 29.118 defines the sending of a paging request * as an event, but as far as the VLR is concerned only Ts5 is * started. */ osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_TX_PAGING, NULL); /* Memorize service type in for the case that the paging must be * respawned after an LU */ vsub->sgs.paging_serv_ind = serv_ind; /* Ensure that the reference count is increased by one while the * paging is happening. We will balance this again in vlr_sgs_pag_rej() * and vlr_sgs_pag_ack(); */ vlr_subscr_get(vsub, VSUB_USE_SGS_PAGING_REQ); } /*! Check if the SGs interface is currently paging * \param[in] vsub VLR subscriber. */ bool vlr_sgs_pag_pend(struct vlr_subscr *vsub) { return osmo_timer_pending(&vsub->sgs.Ts5); }