Harald Welte | 0df904d | 2018-12-03 11:00:04 +0100 | [diff] [blame] | 1 | /* (C) 2018-2019 by sysmocom s.f.m.c. GmbH |
| 2 | * All Rights Reserved |
| 3 | * |
| 4 | * Author: Harald Welte, Philipp Maier |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU Affero General Public License as published by |
| 8 | * the Free Software Foundation; either version 3 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU Affero General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Affero General Public License |
| 17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include <osmocom/core/utils.h> |
| 22 | #include <osmocom/core/fsm.h> |
| 23 | #include <osmocom/gsm/gsm48.h> |
| 24 | #include <osmocom/msc/debug.h> |
| 25 | #include <osmocom/msc/vlr.h> |
| 26 | #include <osmocom/msc/vlr_sgs.h> |
| 27 | |
| 28 | #include "vlr_sgs_fsm.h" |
| 29 | #include "vlr_core.h" |
| 30 | |
| 31 | #define S(x) (1 << (x)) |
| 32 | |
| 33 | static const struct value_string sgs_ue_fsm_event_names[] = { |
| 34 | {SGS_UE_E_VLR_FAILURE, "VLR_FAILURE"}, |
| 35 | {SGS_UE_E_RX_RESET_FROM_MME, "RX_RESET_FROM_MME"}, |
| 36 | {SGS_UE_E_RX_DETACH_IND_FROM_MME, "RX_DETACH_IND_FROM_MME"}, |
| 37 | {SGS_UE_E_RX_DETACH_IND_FROM_UE, "RX_DETACH_IND_FROM_UE"}, /* vlr.c */ |
| 38 | {SGS_UE_E_RX_LU_FROM_A_IU_GS, "RX_LU_FROM_A_Iu_Gs"}, /* vlr_lu_fsm.c */ |
| 39 | {SGS_UE_E_RX_PAGING_FAILURE, "RX_PAGING_FAILURE"}, |
| 40 | {SGS_UE_E_RX_ALERT_FAILURE, "RX_ALERT_FAILURE"}, |
| 41 | {SGS_UE_E_RX_LU_FROM_MME, "RX_LU_FROM_MME"}, |
| 42 | {SGS_UE_E_TX_LU_REJECT, "TX_LU_REJECT"}, |
| 43 | {SGS_UE_E_TX_LU_ACCEPT, "TX_LU_ACCEPT"}, |
| 44 | {SGS_UE_E_TX_PAGING, "TX_PAGING"}, |
| 45 | {SGS_UE_E_RX_SGSAP_UE_UNREACHABLE, "RX_SGSAP_UE_UNREACH"}, |
| 46 | {SGS_UE_E_RX_TMSI_REALLOC, "RX_TMSI_REALLOC"}, |
| 47 | {0, NULL} |
| 48 | }; |
| 49 | |
| 50 | /* Initiate location update and change to SGS_UE_ST_LA_UPD_PRES state */ |
| 51 | static void perform_lu(struct osmo_fsm_inst *fi) |
| 52 | { |
| 53 | struct vlr_subscr *vsub = fi->priv; |
| 54 | int rc; |
| 55 | osmo_fsm_inst_state_chg(fi, SGS_UE_ST_LA_UPD_PRES, 0, 0); |
| 56 | vsub->ms_not_reachable_flag = false; |
| 57 | |
| 58 | /* Note: At the moment we allocate a new TMSI on each LU. */ |
| 59 | rc = vlr_subscr_alloc_tmsi(vsub); |
| 60 | if (rc != 0) |
| 61 | LOGPFSML(fi, LOGL_ERROR, "(sub %s) VLR LU tmsi allocation failed\n", vlr_subscr_name(vsub)); |
| 62 | |
| 63 | rc = vlr_subscr_req_lu(vsub); |
| 64 | if (rc != 0) |
| 65 | LOGPFSML(fi, LOGL_ERROR, "(sub %s) HLR LU request failed\n", vlr_subscr_name(vsub)); |
| 66 | } |
| 67 | |
| 68 | /* Send the SGs Association to NULL state immediately */ |
| 69 | static void to_null(struct osmo_fsm_inst *fi) |
| 70 | { |
| 71 | struct vlr_subscr *vsub = fi->priv; |
| 72 | osmo_fsm_inst_state_chg(fi, SGS_UE_ST_NULL, 0, 0); |
| 73 | |
| 74 | /* Note: This is only relevent for cases where we are in the middle |
| 75 | * of an TMSI reallocation procedure. Should a failure of some sort |
| 76 | * put us to NULL state, we have to free the pending TMSI */ |
| 77 | vsub->tmsi_new = GSM_RESERVED_TMSI; |
| 78 | |
| 79 | /* Make sure any ongoing paging is aborted. */ |
| 80 | vsub->cs.is_paging = false; |
| 81 | |
| 82 | /* Ensure that Ts5 (pending paging via SGs) is deleted */ |
| 83 | if (vlr_sgs_pag_pend(vsub)) |
| 84 | osmo_timer_del(&vsub->sgs.Ts5); |
| 85 | } |
| 86 | |
| 87 | /* Respawn a pending paging (Timer is reset and a new paging request is sent) */ |
| 88 | static void respawn_paging(struct vlr_subscr *vsub) |
| 89 | { |
| 90 | if (vlr_sgs_pag_pend(vsub)) { |
| 91 | |
| 92 | /* Delete the old paging timer first. */ |
| 93 | osmo_timer_del(&vsub->sgs.Ts5); |
| 94 | |
| 95 | /* Issue a fresh paging request */ |
| 96 | vsub->sgs.paging_cb(vsub, vsub->sgs.paging_serv_ind); |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | /* Figure 4.2.2.1 SGs-NULL */ |
| 101 | static void sgs_ue_fsm_null(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 102 | { |
| 103 | switch (event) { |
| 104 | case SGS_UE_E_RX_LU_FROM_MME: |
| 105 | perform_lu(fi); |
| 106 | break; |
| 107 | case SGS_UE_E_TX_PAGING: |
| 108 | /* do nothing */ |
| 109 | break; |
| 110 | case SGS_UE_E_RX_PAGING_FAILURE: |
| 111 | /* do nothing */ |
| 112 | break; |
| 113 | default: |
| 114 | OSMO_ASSERT(0); |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | /* Figure 4.2.2.1 SGs-LA-UPDATE-PRESENT */ |
| 119 | static void sgs_ue_fsm_lau_present(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 120 | { |
| 121 | struct vlr_subscr *vsub = fi->priv; |
| 122 | enum sgsap_sgs_cause *cause = NULL; |
| 123 | |
| 124 | switch (event) { |
| 125 | case SGS_UE_E_TX_LU_ACCEPT: |
| 126 | vsub->conf_by_radio_contact_ind = true; |
| 127 | vsub->sub_dataconf_by_hlr_ind = true; |
| 128 | vsub->loc_conf_in_hlr_ind = true; |
| 129 | vsub->la_allowed = true; |
| 130 | vsub->imsi_detached_flag = false; |
| 131 | vsub->lu_complete = true; |
| 132 | vlr_sgs_fsm_update_id(vsub); |
| 133 | vsub->cs.attached_via_ran = OSMO_RAT_EUTRAN_SGS; |
| 134 | |
| 135 | /* Check if we expect a TMSI REALLOCATION COMPLETE message from the MME |
| 136 | * by checking the tmsi_new flag. If this flag is not GSM_RESERVED_TMSI |
| 137 | * we know that we have a TMSI pending and need to wait for the MME |
| 138 | * to acknowlege first */ |
| 139 | if (vsub->tmsi_new != GSM_RESERVED_TMSI) { |
| 140 | osmo_fsm_inst_state_chg(fi, SGS_UE_ST_ASSOCIATED, vsub->sgs.cfg.timer[SGS_STATE_TS6_2], |
| 141 | SGS_STATE_TS6_2); |
| 142 | } else { |
| 143 | /* Trigger sending of an MM information request */ |
| 144 | vsub->sgs.mminfo_cb(vsub); |
| 145 | |
| 146 | /* In cases where the LU has interrupted the paging, respawn the paging now, |
| 147 | * See also: 3GPP TS 29.118, chapter 5.2.3.2 Location update response */ |
| 148 | if (vlr_sgs_pag_pend(vsub)) |
| 149 | respawn_paging(vsub); |
| 150 | |
| 151 | osmo_fsm_inst_state_chg(fi, SGS_UE_ST_ASSOCIATED, 0, 0); |
| 152 | } |
| 153 | |
| 154 | break; |
| 155 | case SGS_UE_E_RX_PAGING_FAILURE: |
| 156 | cause = data; |
| 157 | if (*cause == SGSAP_SGS_CAUSE_MT_CSFB_REJ_USER) |
| 158 | break; |
| 159 | to_null(fi); |
| 160 | break; |
| 161 | case SGS_UE_E_TX_LU_REJECT: |
| 162 | case SGS_UE_E_RX_ALERT_FAILURE: |
| 163 | to_null(fi); |
| 164 | break; |
| 165 | case SGS_UE_E_TX_PAGING: |
| 166 | /* do nothing */ |
| 167 | break; |
| 168 | default: |
| 169 | OSMO_ASSERT(0); |
| 170 | break; |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | /* Figure 4.2.2.1 SGs-ASSOCIATED */ |
| 175 | static void sgs_ue_fsm_associated(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 176 | { |
| 177 | struct vlr_subscr *vsub = fi->priv; |
| 178 | enum sgsap_sgs_cause *cause = NULL; |
| 179 | |
| 180 | switch (event) { |
| 181 | case SGS_UE_E_TX_PAGING: |
| 182 | /* do nothing */ |
| 183 | break; |
| 184 | case SGS_UE_E_RX_TMSI_REALLOC: |
| 185 | if (vsub->tmsi_new == GSM_RESERVED_TMSI) { |
| 186 | LOGPFSML(fi, LOGL_ERROR, |
| 187 | "(sub %s) TMSI reallocation completed at the MME, but no TMSI reallocation ordered.\n", |
| 188 | vlr_subscr_msisdn_or_name(vsub)); |
| 189 | } |
| 190 | |
| 191 | vsub->tmsi = vsub->tmsi_new; |
| 192 | vsub->tmsi_new = GSM_RESERVED_TMSI; |
| 193 | |
| 194 | /* Trigger sending of MM information */ |
| 195 | vsub->sgs.mminfo_cb(vsub); |
| 196 | |
| 197 | /* In cases where the LU has interrupted the paging, respawn the paging now, |
| 198 | * See also: 3GPP TS 29.118, chapter 5.2.3.2 Location update response */ |
| 199 | if (vlr_sgs_pag_pend(vsub)) |
| 200 | respawn_paging(vsub); |
| 201 | |
| 202 | /* Note: We are already in SGS_UE_ST_ASSOCIATED but the |
| 203 | * transition that lead us here had is guarded with Ts6-1, |
| 204 | * wo we change the state now once more without timeout |
| 205 | * to ensure the timer is stopped */ |
| 206 | osmo_fsm_inst_state_chg(fi, SGS_UE_ST_ASSOCIATED, 0, 0); |
| 207 | break; |
| 208 | case SGS_UE_E_RX_SGSAP_UE_UNREACHABLE: |
| 209 | /* do nothing */ |
| 210 | break; |
| 211 | case SGS_UE_E_RX_PAGING_FAILURE: |
| 212 | cause = data; |
| 213 | if (*cause == SGSAP_SGS_CAUSE_MT_CSFB_REJ_USER) |
| 214 | break; |
| 215 | to_null(fi); |
| 216 | case SGS_UE_E_RX_ALERT_FAILURE: |
| 217 | to_null(fi); |
| 218 | break; |
| 219 | case SGS_UE_E_RX_LU_FROM_MME: |
| 220 | perform_lu(fi); |
| 221 | break; |
| 222 | default: |
| 223 | OSMO_ASSERT(0); |
| 224 | break; |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | /* Figure 4.2.2.1 From any of the three states (at the VLR) */ |
| 229 | static void sgs_ue_fsm_allstate(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 230 | { |
| 231 | struct vlr_subscr *vsub = fi->priv; |
| 232 | |
| 233 | switch (event) { |
| 234 | case SGS_UE_E_RX_DETACH_IND_FROM_MME: |
| 235 | case SGS_UE_E_RX_DETACH_IND_FROM_UE: |
| 236 | vsub->imsi_detached_flag = true; |
| 237 | vsub->expire_lu = VLR_SUBSCRIBER_NO_EXPIRATION; |
| 238 | /* See 5.4.3 and 5.5.3 */ |
| 239 | to_null(fi); |
| 240 | break; |
| 241 | case SGS_UE_E_RX_RESET_FROM_MME: |
| 242 | /* See also 3GPP TS 29.118, chapter 5.7.2.1 VLR Reset Initiation */ |
| 243 | vsub->conf_by_radio_contact_ind = false; |
| 244 | to_null(fi); |
| 245 | break; |
| 246 | case SGS_UE_E_VLR_FAILURE: |
| 247 | case SGS_UE_E_RX_LU_FROM_A_IU_GS: |
| 248 | to_null(fi); |
| 249 | break; |
| 250 | default: |
| 251 | OSMO_ASSERT(0); |
| 252 | break; |
| 253 | } |
| 254 | } |
| 255 | |
| 256 | static int sgs_ue_fsm_timer_cb(struct osmo_fsm_inst *fi) |
| 257 | { |
| 258 | struct vlr_subscr *vsub = fi->priv; |
| 259 | switch (fi->T) { |
| 260 | |
| 261 | case SGS_STATE_TS6_2: |
| 262 | /* Failed TMSI reallocation procedure, deallocate all TMSI |
| 263 | * information, but don't change the SGs association state. */ |
| 264 | vsub->tmsi_new = GSM_RESERVED_TMSI; |
| 265 | vsub->tmsi = GSM_RESERVED_TMSI; |
| 266 | break; |
| 267 | default: |
| 268 | /* Unhandled timer */ |
| 269 | OSMO_ASSERT(false); |
| 270 | break; |
| 271 | } |
| 272 | return 0; |
| 273 | } |
| 274 | |
| 275 | static const struct osmo_fsm_state sgs_ue_fsm_states[] = { |
| 276 | [SGS_UE_ST_NULL] = { |
| 277 | .name = "SGs-NULL", |
| 278 | .action = sgs_ue_fsm_null, |
| 279 | .in_event_mask = 0 |
| 280 | | S(SGS_UE_E_RX_LU_FROM_MME) |
| 281 | | S(SGS_UE_E_TX_PAGING) |
| 282 | | S(SGS_UE_E_RX_PAGING_FAILURE) |
| 283 | , |
| 284 | .out_state_mask = 0 |
| 285 | | S(SGS_UE_ST_NULL) |
| 286 | | S(SGS_UE_ST_LA_UPD_PRES) |
| 287 | , |
| 288 | }, |
| 289 | [SGS_UE_ST_LA_UPD_PRES] = { |
| 290 | .name = "SGs-LA-UPDATE-PRESENT", |
| 291 | .action = sgs_ue_fsm_lau_present, |
| 292 | .in_event_mask = 0 |
| 293 | | S(SGS_UE_E_TX_LU_ACCEPT) |
| 294 | | S(SGS_UE_E_TX_LU_REJECT) |
| 295 | | S(SGS_UE_E_TX_PAGING) |
| 296 | | S(SGS_UE_E_RX_PAGING_FAILURE) |
| 297 | | S(SGS_UE_E_RX_ALERT_FAILURE) |
| 298 | , |
| 299 | .out_state_mask = 0 |
| 300 | | S(SGS_UE_ST_NULL) |
| 301 | | S(SGS_UE_ST_ASSOCIATED) |
| 302 | | S(SGS_UE_ST_LA_UPD_PRES) |
| 303 | , |
| 304 | }, |
| 305 | [SGS_UE_ST_ASSOCIATED] = { |
| 306 | .name = "SGs-ASSOCIATED", |
| 307 | .action = sgs_ue_fsm_associated, |
| 308 | .in_event_mask = 0 |
| 309 | | S(SGS_UE_E_TX_PAGING) |
| 310 | | S(SGS_UE_E_RX_TMSI_REALLOC) |
| 311 | | S(SGS_UE_E_RX_SGSAP_UE_UNREACHABLE) |
| 312 | | S(SGS_UE_E_RX_PAGING_FAILURE) |
| 313 | | S(SGS_UE_E_RX_ALERT_FAILURE) |
| 314 | | S(SGS_UE_E_RX_LU_FROM_MME) |
| 315 | , |
| 316 | .out_state_mask = 0 |
| 317 | | S(SGS_UE_ST_NULL) |
| 318 | | S(SGS_UE_ST_ASSOCIATED) |
| 319 | | S(SGS_UE_ST_LA_UPD_PRES) |
| 320 | , |
| 321 | }, |
| 322 | }; |
| 323 | |
| 324 | static struct osmo_fsm sgs_ue_fsm = { |
| 325 | .name = "SGs-UE", |
| 326 | .states = sgs_ue_fsm_states, |
| 327 | .num_states = ARRAY_SIZE(sgs_ue_fsm_states), |
| 328 | .allstate_event_mask = S(SGS_UE_E_RX_RESET_FROM_MME) | |
| 329 | S(SGS_UE_E_VLR_FAILURE) | S(SGS_UE_E_RX_DETACH_IND_FROM_MME) | S(SGS_UE_E_RX_DETACH_IND_FROM_UE) | |
| 330 | S(SGS_UE_E_RX_LU_FROM_A_IU_GS), |
| 331 | .allstate_action = sgs_ue_fsm_allstate, |
| 332 | .timer_cb = sgs_ue_fsm_timer_cb, |
| 333 | .log_subsys = DSGS, |
| 334 | .event_names = sgs_ue_fsm_event_names, |
| 335 | }; |
| 336 | |
| 337 | /*! Initalize/Register SGs FSM in osmo-fsm subsystem */ |
| 338 | void vlr_sgs_fsm_init(void) |
| 339 | { |
| 340 | if (osmo_fsm_find_by_name(sgs_ue_fsm.name) != &sgs_ue_fsm) |
| 341 | osmo_fsm_register(&sgs_ue_fsm); |
| 342 | } |
| 343 | |
| 344 | /*! Crate SGs FSM in struct vlr_subscr. |
| 345 | * \param[in] vsub VLR subscriber for which the SGs FSM should be created. */ |
| 346 | void vlr_sgs_fsm_create(struct vlr_subscr *vsub) |
| 347 | { |
| 348 | char interim_fsm_id[256]; |
| 349 | static unsigned int fsm_id_num = 0; |
| 350 | |
| 351 | /* An SGSs FSM must not be created twice! */ |
| 352 | OSMO_ASSERT(!vsub->sgs_fsm); |
| 353 | |
| 354 | snprintf(interim_fsm_id, sizeof(interim_fsm_id), "num:%u", fsm_id_num); |
| 355 | |
| 356 | vsub->sgs_fsm = osmo_fsm_inst_alloc(&sgs_ue_fsm, vsub, vsub, LOGL_INFO, interim_fsm_id); |
| 357 | OSMO_ASSERT(vsub->sgs_fsm); |
| 358 | |
| 359 | osmo_fsm_inst_state_chg(vsub->sgs_fsm, SGS_UE_ST_NULL, 0, 0); |
| 360 | |
| 361 | fsm_id_num++; |
| 362 | } |
| 363 | |
| 364 | /*! Remove SGs FSM from struct vlr_subscr. |
| 365 | * \param[in] vsub VLR subscriber from which the SGs FSM should be removed. */ |
| 366 | void vlr_sgs_fsm_remove(struct vlr_subscr *vsub) |
| 367 | { |
| 368 | /* An SGSs FSM must exist! */ |
| 369 | OSMO_ASSERT(vsub->sgs_fsm); |
| 370 | |
| 371 | osmo_fsm_inst_state_chg(vsub->sgs_fsm, SGS_UE_ST_NULL, 0, 0); |
| 372 | osmo_fsm_inst_term(vsub->sgs_fsm, OSMO_FSM_TERM_REGULAR, NULL); |
| 373 | vsub->sgs_fsm = NULL; |
| 374 | } |
| 375 | |
| 376 | /*! Update the ID of the SGs FSM with the subscriber IMSI |
| 377 | * \param[in] vsub VLR subscriber to update. */ |
| 378 | void vlr_sgs_fsm_update_id(struct vlr_subscr *vsub) |
| 379 | { |
| 380 | char fsm_id[256]; |
| 381 | |
| 382 | if (strlen(vsub->imsi) > 0) { |
| 383 | snprintf(fsm_id, sizeof(fsm_id), "imsi:%s", vsub->imsi); |
| 384 | osmo_fsm_inst_update_id(vsub->sgs_fsm, fsm_id); |
| 385 | } |
| 386 | } |