| /* (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 <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #include <errno.h> |
| |
| #include <osmocom/core/utils.h> |
| #include <osmocom/core/fsm.h> |
| #include <osmocom/msc/debug.h> |
| #include <osmocom/msc/vlr.h> |
| #include <osmocom/msc/vlr_sgs.h> |
| #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); |
| } |