diff options
Diffstat (limited to 'src/libvlr/vlr_sgs.c')
| -rw-r--r-- | src/libvlr/vlr_sgs.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/src/libvlr/vlr_sgs.c b/src/libvlr/vlr_sgs.c new file mode 100644 index 000000000..861489227 --- /dev/null +++ b/src/libvlr/vlr_sgs.c @@ -0,0 +1,331 @@ +/* (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 <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 instace. */ +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 instace. + * \param[in] cfg SGs interface configuration parameters. + * \param[in] response_cb calback function that is called when LU is done. + * \param[in] paging_cb calback function that is called when LU needs to page. + * \param[in] mminfo_cb calback 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. + * \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 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, 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); + 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; + + 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); + + /* 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); +} + +/*! 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); + if (!vsub) + 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); + vlr_subscr_put(vsub); +} + +/*! 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); + 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); + vlr_subscr_put(vsub); +} + +/*! 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); + if (!vsub) + return; + + osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_RX_TMSI_REALLOC, NULL); + vlr_subscr_put(vsub); +} + +/*! 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); + 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); + vlr_subscr_put(vsub); + + /* Balance ref count increment from vlr_sgs_pag() */ + vlr_subscr_put(vsub); +} + +/*! 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); + if (!vsub) + return; + + /* Stop Ts5 and and consider the paging as successful */ + osmo_timer_del(&vsub->sgs.Ts5); + vlr_subscr_put(vsub); + + /* Balance ref count increment from vlr_sgs_pag() */ + vlr_subscr_put(vsub); +} + +/*! 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); + 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); +} + +/* 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 specif 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); + + 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). + * Apparantly 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); +} + +/*! 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); +} |