Harald Welte | 0df904d | 2018-12-03 11:00:04 +0100 | [diff] [blame] | 1 | /* SGs Interface according to 3GPP TS 23.272 + TS 29.118 */ |
| 2 | |
| 3 | /* (C) 2018-2019 by sysmocom s.f.m.c. GmbH |
| 4 | * All Rights Reserved |
| 5 | * |
| 6 | * Author: Harald Welte, Philipp Maier |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU Affero General Public License as published by |
| 10 | * the Free Software Foundation; either version 3 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU Affero General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Affero General Public License |
| 19 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 20 | * |
| 21 | */ |
| 22 | |
| 23 | #include <osmocom/core/utils.h> |
| 24 | #include <osmocom/core/msgb.h> |
| 25 | #include <osmocom/core/fsm.h> |
| 26 | #include <osmocom/core/socket.h> |
| 27 | #include <osmocom/core/select.h> |
| 28 | |
| 29 | #include <osmocom/gsm/tlv.h> |
| 30 | #include <osmocom/gsm/gsm48.h> |
| 31 | #include <osmocom/gsm/gsm23003.h> |
| 32 | #include <osmocom/gsm/gsm29118.h> |
| 33 | |
| 34 | #include <osmocom/netif/stream.h> |
| 35 | |
| 36 | #include <osmocom/msc/vlr.h> |
| 37 | #include <osmocom/msc/vlr_sgs.h> |
| 38 | #include <osmocom/msc/gsm_data.h> |
| 39 | #include <osmocom/msc/a_iface.h> |
| 40 | #include <osmocom/msc/gsm_04_08.h> |
| 41 | |
| 42 | #include <osmocom/msc/debug.h> |
| 43 | #include <osmocom/msc/sgs_iface.h> |
| 44 | #include <osmocom/msc/sgs_server.h> |
| 45 | #include <osmocom/msc/msc_ifaces.h> |
| 46 | #include <osmocom/gsm/protocol/gsm_29_118.h> |
| 47 | |
| 48 | #include <osmocom/gsm/apn.h> |
| 49 | |
| 50 | #define S(x) (1 << (x)) |
| 51 | |
| 52 | /* A pointer to the GSM network we work with. By the current paradigm, |
| 53 | * there can only be one gsm_network per MSC. The pointer is set once |
Vadim Yanitskiy | 118a0b8 | 2019-03-21 20:51:55 +0700 | [diff] [blame] | 54 | * when calling sgs_iface_init() */ |
Harald Welte | 0df904d | 2018-12-03 11:00:04 +0100 | [diff] [blame] | 55 | static struct gsm_network *gsm_network = NULL; |
| 56 | |
| 57 | static struct osmo_fsm sgs_vlr_reset_fsm; |
| 58 | static void sgs_tx(struct sgs_connection *sgc, struct msgb *msg); |
| 59 | |
| 60 | struct sgs_state *g_sgs; |
| 61 | |
| 62 | /*********************************************************************** |
| 63 | * SGs state per MME connection |
| 64 | ***********************************************************************/ |
| 65 | |
| 66 | #define LOGSGC(sgc, lvl, fmt, args...) \ |
| 67 | LOGP(DSGS, lvl, "%s: " fmt, sgc->sockname, ## args) |
| 68 | |
| 69 | #define LOGSGC_VSUB(sgc, sub_info, lvl, fmt, args...) \ |
| 70 | LOGP(DSGS, lvl, "(sub %s) %s: " fmt, sub_info, sgc->sockname, ## args) |
| 71 | |
| 72 | #define LOGMME(mme, lvl, fmt, args...) \ |
| 73 | LOGP(DSGS, lvl, "%s: " fmt, mme->fqdn ? mme->fqdn : mme->conn->sockname, ## args) |
| 74 | |
| 75 | enum sgs_vlr_reset_fsm_state { |
| 76 | SGS_VLRR_ST_NULL, |
| 77 | SGS_VLRR_ST_WAIT_ACK, |
| 78 | SGS_VLRR_ST_COMPLETE, |
| 79 | }; |
| 80 | |
| 81 | enum sgs_vlr_reset_fsm_event { |
| 82 | SGS_VLRR_E_START_RESET, |
| 83 | SGS_VLRR_E_RX_RESET_ACK, |
| 84 | }; |
| 85 | |
| 86 | /*********************************************************************** |
| 87 | * SGs utility functions |
| 88 | ***********************************************************************/ |
| 89 | |
| 90 | /* Allocate a new subscriber connection */ |
| 91 | static struct ran_conn *subscr_conn_allocate_sgs(struct sgs_connection *sgc, struct vlr_subscr *vsub, bool mt) |
| 92 | { |
| 93 | struct ran_conn *conn; |
| 94 | |
| 95 | conn = ran_conn_alloc(gsm_network, OSMO_RAT_EUTRAN_SGS, vsub->sgs.lai.lac); |
| 96 | if (!conn) { |
| 97 | LOGSGC_VSUB(sgc, vlr_subscr_name(vsub), LOGL_ERROR, "Connection allocation failed\n"); |
| 98 | return NULL; |
| 99 | } |
| 100 | |
| 101 | conn->vsub = vsub; |
| 102 | conn->vsub->cs.attached_via_ran = conn->via_ran; |
| 103 | |
| 104 | /* Accept the connection immediately, since the UE is already |
| 105 | * authenticated by the MME no authentication is required. */ |
| 106 | conn->complete_layer3_type = mt ? COMPLETE_LAYER3_PAGING_RESP : COMPLETE_LAYER3_CM_SERVICE_REQ; |
| 107 | ran_conn_update_id(conn); |
| 108 | osmo_fsm_inst_dispatch(conn->fi, RAN_CONN_E_COMPLETE_LAYER_3, NULL); |
| 109 | osmo_fsm_inst_dispatch(conn->fi, RAN_CONN_E_ACCEPTED, NULL); |
| 110 | |
| 111 | LOG_RAN_CONN(conn, LOGL_DEBUG, "RAN connection successfully allocated!\n"); |
| 112 | return conn; |
| 113 | } |
| 114 | |
| 115 | /* Check if there are connections associated with a given subscriber. If yes, |
| 116 | * make sure that those connections are tossed. */ |
| 117 | static void subscr_conn_toss(struct vlr_subscr *vsub) |
| 118 | { |
| 119 | struct ran_conn *conn; |
| 120 | |
| 121 | conn = connection_for_subscr(vsub); |
| 122 | if (!conn) |
| 123 | return; |
| 124 | |
| 125 | LOG_RAN_CONN(conn, LOGL_DEBUG, "RAN connection tossed because of unexpected RAN change!\n"); |
| 126 | |
| 127 | ran_conn_mo_close(conn, GSM48_REJECT_CONGESTION); |
| 128 | } |
| 129 | |
| 130 | struct sgs_mme_ctx *sgs_mme_by_fqdn(struct sgs_state *sgs, const char *mme_fqdn) |
| 131 | { |
| 132 | struct sgs_mme_ctx *mme; |
| 133 | |
| 134 | llist_for_each_entry(mme, &sgs->mme_list, entry) { |
| 135 | if (!strcasecmp(mme_fqdn, mme->fqdn)) |
| 136 | return mme; |
| 137 | } |
| 138 | return NULL; |
| 139 | } |
| 140 | |
| 141 | static struct sgs_mme_ctx *sgs_mme_alloc(struct sgs_state *sgs, const char *mme_fqdn, const struct osmo_gummei *gummei) |
| 142 | { |
| 143 | struct sgs_mme_ctx *mme; |
| 144 | |
| 145 | OSMO_ASSERT(sgs_mme_by_fqdn(sgs, mme_fqdn) == NULL); |
| 146 | |
| 147 | mme = talloc_zero(sgs, struct sgs_mme_ctx); |
| 148 | if (!mme) |
| 149 | return NULL; |
| 150 | mme->sgs = sgs; |
| 151 | OSMO_STRLCPY_ARRAY(mme->fqdn, mme_fqdn); |
| 152 | mme->fi = osmo_fsm_inst_alloc(&sgs_vlr_reset_fsm, mme, mme, LOGL_INFO, osmo_gummei_name(gummei)); |
| 153 | if (!mme->fi) { |
| 154 | talloc_free(mme); |
| 155 | return NULL; |
| 156 | } |
| 157 | llist_add_tail(&mme->entry, &sgs->mme_list); |
| 158 | return mme; |
| 159 | } |
| 160 | |
| 161 | /* Decode and verify MME name */ |
| 162 | static int decode_mme_name(char *mme_name, const struct tlv_parsed *tp) |
| 163 | { |
| 164 | const uint8_t *mme_name_enc = TLVP_VAL_MINLEN(tp, SGSAP_IE_MME_NAME, SGS_MME_NAME_LEN); |
| 165 | struct osmo_gummei gummei; |
| 166 | |
| 167 | if (!mme_name_enc) |
| 168 | return -EINVAL; |
| 169 | |
| 170 | /* decode the MME name from DNS labels to string */ |
| 171 | osmo_apn_to_str(mme_name, TLVP_VAL(tp, SGSAP_IE_MME_NAME), TLVP_LEN(tp, SGSAP_IE_MME_NAME)); |
| 172 | |
| 173 | /* try to parse the MME name into a GUMMEI as a test for the format */ |
| 174 | if (osmo_parse_mme_domain(&gummei, mme_name) < 0) |
| 175 | return -EINVAL; |
| 176 | |
| 177 | return 0; |
| 178 | } |
| 179 | |
| 180 | /* A MME FQDN was received (e.g. RESET-IND/RESET-ACK/LU-REQ) */ |
| 181 | static int sgs_mme_fqdn_received(struct sgs_connection *sgc, const char *mme_fqdn) |
| 182 | { |
| 183 | struct sgs_mme_ctx *mme; |
| 184 | struct osmo_gummei gummei; |
| 185 | |
| 186 | /* caller must pass in a valid FQDN string syntax */ |
| 187 | OSMO_ASSERT(osmo_parse_mme_domain(&gummei, mme_fqdn) == 0); |
| 188 | |
| 189 | if (!sgc->mme) { |
| 190 | /* attempt to find MME with given name */ |
| 191 | mme = sgs_mme_by_fqdn(sgc->sgs, mme_fqdn); |
| 192 | if (!mme) |
| 193 | mme = sgs_mme_alloc(sgc->sgs, mme_fqdn, &gummei); |
| 194 | OSMO_ASSERT(mme); |
| 195 | |
| 196 | if (mme->conn) { |
| 197 | /* The MME context has another connection !?! */ |
| 198 | LOGSGC(sgc, LOGL_ERROR, "Rx MME name %s, but that MME already has other " |
| 199 | "SCTP connection?!?\n", mme_fqdn); |
| 200 | return -1; |
| 201 | } else { |
| 202 | /* associate the two */ |
| 203 | mme->conn = sgc; |
| 204 | sgc->mme = mme; |
| 205 | } |
| 206 | } else { |
| 207 | mme = sgc->mme; |
| 208 | if (strcasecmp(mme->fqdn, mme_fqdn) != 0) { |
| 209 | LOGMME(mme, LOGL_ERROR, "Rx MME name \"%s\" in packet from MME \"%s\" ?!?\n", mme_fqdn, |
| 210 | mme->fqdn); |
| 211 | return -2; |
| 212 | } |
| 213 | } |
| 214 | return 0; |
| 215 | } |
| 216 | |
| 217 | /* Safely get the mme-name for an sgs-connection */ |
| 218 | static char *sgs_mme_fqdn_get(struct sgs_connection *sgc) |
| 219 | { |
| 220 | if (!sgc) |
| 221 | return NULL; |
| 222 | if (!sgc->mme) |
| 223 | return NULL; |
| 224 | if (sgc->mme->fqdn[0] == '\0') |
| 225 | return NULL; |
| 226 | return sgc->mme->fqdn; |
| 227 | } |
| 228 | |
| 229 | /* Find an sgs_mme_ctx for a given vlr subscriber, also check result */ |
| 230 | struct sgs_mme_ctx *sgs_mme_ctx_by_vsub(struct vlr_subscr *vsub, uint8_t msg_type) |
| 231 | { |
| 232 | struct sgs_mme_ctx *mme; |
| 233 | |
| 234 | /* Find SGS connection by MME name */ |
| 235 | mme = sgs_mme_by_fqdn(g_sgs, vsub->sgs.mme_name); |
| 236 | if (!mme) { |
| 237 | LOGP(DSGS, LOGL_ERROR, "(sub %s) Tx %s cannot find suitable MME!\n", |
| 238 | vlr_subscr_name(vsub), sgsap_msg_type_name(msg_type)); |
| 239 | return NULL; |
| 240 | } |
| 241 | if (!mme->conn) { |
| 242 | LOGP(DSGS, LOGL_ERROR, |
| 243 | "(sub %s) Tx %s suitable MME found, but no SGS connection present!\n", |
| 244 | vlr_subscr_name(vsub), sgsap_msg_type_name(msg_type)); |
| 245 | return NULL; |
| 246 | } |
| 247 | if (!mme->sgs) { |
| 248 | LOGP(DSGS, LOGL_ERROR, |
| 249 | "(sub %s) Tx %s suitable MME found, but no SGS state present!\n", |
| 250 | vlr_subscr_name(vsub), sgsap_msg_type_name(msg_type)); |
| 251 | return NULL; |
| 252 | } |
| 253 | |
| 254 | return mme; |
| 255 | } |
| 256 | |
| 257 | /* Make sure that the subscriber is known and that the subscriber is in the |
| 258 | * SGs associated state. In case of failure the function returns false and |
| 259 | * automatically sends a release message to the MME */ |
| 260 | static bool check_sgs_association(struct sgs_connection *sgc, struct msgb *msg, char *imsi) |
| 261 | { |
| 262 | struct vlr_subscr *vsub; |
| 263 | struct msgb *resp; |
| 264 | uint8_t msg_type = msg->data[0]; |
| 265 | |
| 266 | /* Subscriber must be known by the VLR */ |
| 267 | vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi); |
| 268 | if (!vsub) { |
| 269 | LOGSGC(sgc, LOGL_NOTICE, "SGsAP Message %s with unknown IMSI (%s), releasing\n", |
| 270 | sgsap_msg_type_name(msg_type), imsi); |
| 271 | resp = gsm29118_create_release_req(imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN); |
| 272 | sgs_tx(sgc, resp); |
| 273 | return false; |
| 274 | } |
| 275 | |
| 276 | /* The SGs FSM must also be in SGs associated state */ |
| 277 | if (vsub->sgs_fsm->state != SGS_UE_ST_ASSOCIATED) { |
| 278 | LOGSGC(sgc, LOGL_NOTICE, "(sub %s) SGsAP Message %s subscriber not SGs-associated, releasing\n", |
| 279 | vlr_subscr_name(vsub), sgsap_msg_type_name(msg_type)); |
| 280 | resp = gsm29118_create_release_req(vsub->imsi, SGSAP_SGS_CAUSE_IMSI_DET_EPS_NONEPS); |
| 281 | sgs_tx(sgc, resp); |
| 282 | vlr_subscr_put(vsub); |
| 283 | return false; |
| 284 | } |
| 285 | |
| 286 | vlr_subscr_put(vsub); |
| 287 | return true; |
| 288 | } |
| 289 | |
| 290 | /*********************************************************************** |
| 291 | * SGsAP transmit functions |
| 292 | ***********************************************************************/ |
| 293 | |
| 294 | /* Send message out to remote end (final step) */ |
| 295 | static void sgs_tx(struct sgs_connection *sgc, struct msgb *msg) |
| 296 | { |
| 297 | if (!msg) { |
| 298 | LOGSGC(sgc, LOGL_NOTICE, "Null message, cannot transmit!\n"); |
| 299 | return; |
| 300 | } |
| 301 | |
| 302 | msgb_sctp_ppid(msg) = 0; |
| 303 | if (!sgc) { |
| 304 | LOGSGC(sgc, LOGL_NOTICE, "Cannot transmit %s: connection dead. Discarding\n", |
| 305 | sgsap_msg_type_name(msg->data[0])); |
| 306 | msgb_free(msg); |
| 307 | return; |
| 308 | } |
| 309 | osmo_stream_srv_send(sgc->srv, msg); |
| 310 | } |
| 311 | |
| 312 | /* Get some subscriber info from ISMI (for the log text) */ |
| 313 | const char *subscr_info(const char *imsi) |
| 314 | { |
| 315 | const char *subscr_string = "<unknown>"; |
| 316 | struct vlr_subscr *vsub; |
| 317 | |
| 318 | if (imsi) { |
| 319 | vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi); |
| 320 | if (!vsub) |
| 321 | subscr_string = imsi; |
| 322 | else { |
| 323 | subscr_string = vlr_subscr_name(vsub); |
| 324 | vlr_subscr_put(vsub); |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | return subscr_string; |
| 329 | } |
| 330 | |
| 331 | /* Comfortable status message generator that also generates some basic |
| 332 | * context-dependent dependand log output */ |
| 333 | static int sgs_tx_status(struct sgs_connection *sgc, const char *imsi, enum sgsap_sgs_cause cause, struct msgb *msg, |
| 334 | int sgsap_iei) |
| 335 | { |
| 336 | struct msgb *resp; |
| 337 | |
| 338 | if (sgsap_iei < 0) { |
| 339 | LOGSGC_VSUB(sgc, subscr_info(imsi), LOGL_ERROR, "Rx %s failed with cause %s!\n", |
| 340 | sgsap_msg_type_name(msg->data[0]), sgsap_sgs_cause_name(cause)); |
| 341 | } else if (cause == SGSAP_SGS_CAUSE_MISSING_MAND_IE) { |
| 342 | LOGSGC_VSUB(sgc, subscr_info(imsi), LOGL_ERROR, "Rx %s with missing mandatory %s IEI!\n", |
| 343 | sgsap_msg_type_name(msg->data[0]), sgsap_iei_name(sgsap_iei)); |
| 344 | } else if (cause == SGSAP_SGS_CAUSE_INVALID_MAND_IE) { |
| 345 | LOGSGC_VSUB(sgc, subscr_info(imsi), LOGL_ERROR, "Rx %s with invalid mandatory %s IEI!\n", |
| 346 | sgsap_msg_type_name(msg->data[0]), sgsap_iei_name(sgsap_iei)); |
| 347 | } else if (cause == SGSAP_SGS_CAUSE_COND_IE_ERROR) { |
| 348 | LOGSGC_VSUB(sgc, subscr_info(imsi), LOGL_ERROR, "Rx %s with errornous conditional %s IEI!\n", |
| 349 | sgsap_msg_type_name(msg->data[0]), sgsap_iei_name(sgsap_iei)); |
| 350 | } else { |
| 351 | LOGSGC_VSUB(sgc, subscr_info(imsi), LOGL_ERROR, "Rx %s failed with cause %s at %s IEI!\n", |
| 352 | sgsap_msg_type_name(msg->data[0]), sgsap_sgs_cause_name(cause), sgsap_iei_name(sgsap_iei)); |
| 353 | } |
| 354 | |
| 355 | resp = gsm29118_create_status(imsi, cause, msg); |
| 356 | sgs_tx(sgc, resp); |
| 357 | return 0; |
| 358 | } |
| 359 | |
| 360 | /* Called by VLR via callback, transmits the the location update response or |
| 361 | * reject, depending on the outcome of the location update. */ |
| 362 | static void sgs_tx_loc_upd_resp_cb(struct sgs_lu_response *response) |
| 363 | { |
| 364 | struct msgb *resp; |
| 365 | struct vlr_subscr *vsub = response->vsub; |
| 366 | struct sgs_mme_ctx *mme; |
| 367 | uint8_t new_id[2 + GSM48_TMSI_LEN]; |
| 368 | uint8_t *new_id_ptr = new_id; |
| 369 | unsigned int new_id_len = 0; |
| 370 | uint8_t resp_msg_type; |
| 371 | |
| 372 | if (response->accepted) |
| 373 | resp_msg_type = SGSAP_MSGT_LOC_UPD_ACK; |
| 374 | else |
| 375 | resp_msg_type = SGSAP_MSGT_LOC_UPD_REJ; |
| 376 | |
| 377 | mme = sgs_mme_ctx_by_vsub(vsub, resp_msg_type); |
| 378 | if (!mme) |
| 379 | return; |
| 380 | |
| 381 | if (response->accepted) { |
| 382 | if (vsub->tmsi_new != GSM_RESERVED_TMSI) { |
| 383 | new_id_len = gsm48_generate_mid_from_tmsi(new_id, vsub->tmsi_new); |
| 384 | new_id_ptr = new_id + 2; |
| 385 | new_id_len -= 2; |
| 386 | } |
| 387 | resp = gsm29118_create_lu_ack(vsub->imsi, &vsub->sgs.lai, new_id_ptr, new_id_len); |
| 388 | sgs_tx(mme->conn, resp); |
| 389 | vlr_sgs_loc_update_acc_sent(vsub); |
| 390 | } else { |
| 391 | resp = gsm29118_create_lu_rej(vsub->imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN, &vsub->sgs.lai); |
| 392 | sgs_tx(mme->conn, resp); |
| 393 | vlr_sgs_loc_update_rej_sent(vsub); |
| 394 | } |
| 395 | } |
| 396 | |
| 397 | /* Called by VLR via callback, transmits MM information to the UE */ |
| 398 | static void sgs_tx_mm_info_cb(struct vlr_subscr *vsub) |
| 399 | { |
| 400 | struct msgb *msg; |
| 401 | struct msgb *msg_mm_info; |
| 402 | struct sgs_mme_ctx *mme; |
| 403 | |
| 404 | /* The sending of MM information requests is an optional feature and |
| 405 | * depends on the network configuration (VTY) */ |
| 406 | if (!gsm_network->send_mm_info) |
| 407 | return; |
| 408 | |
| 409 | mme = sgs_mme_ctx_by_vsub(vsub, SGSAP_MSGT_MM_INFO_REQ); |
| 410 | if (!mme) |
| 411 | return; |
| 412 | |
| 413 | /* Create and send MM information request message, see also: |
| 414 | * 3GPP TS 29.118, chapter 8.12 SGsAP-MM-INFORMATION-REQUEST and |
| 415 | * 3GPP TS 29.018, chapter 18.4.16 MM information. */ |
| 416 | msg_mm_info = gsm48_create_mm_info(gsm_network); |
| 417 | msg = gsm29118_create_mm_info_req(vsub->imsi, msg_mm_info->data + 2, msg_mm_info->len - 2); |
| 418 | sgs_tx(mme->conn, msg); |
| 419 | msgb_free(msg_mm_info); |
| 420 | } |
| 421 | |
| 422 | /*! Page UE through SGs interface |
| 423 | * \param[in] vsub subscriber context |
| 424 | * \param[in] serv_ind service indicator (sms or voide) |
| 425 | * \returns 0 in case of success, -EINVAL in case of error. */ |
| 426 | int sgs_iface_tx_paging(struct vlr_subscr *vsub, enum sgsap_service_ind serv_ind) |
| 427 | { |
| 428 | struct msgb *resp; |
| 429 | struct gsm29118_paging_req paging_params; |
| 430 | struct sgs_mme_ctx *mme; |
| 431 | |
| 432 | /* See also: 3GPP TS 29.118, chapter 5.1.2.2 Paging Initiation */ |
| 433 | if (vsub->sgs_fsm->state == SGS_UE_ST_NULL && vsub->conf_by_radio_contact_ind == true) |
| 434 | return -EINVAL; |
| 435 | |
| 436 | mme = sgs_mme_ctx_by_vsub(vsub, SGSAP_MSGT_PAGING_REQ); |
| 437 | if (!mme) |
| 438 | return -EINVAL; |
| 439 | |
| 440 | /* Check if there is still a paging in progress for this subscriber, |
| 441 | * if yes, don't initiate another paging request. */ |
| 442 | if (vlr_sgs_pag_pend(vsub)) |
| 443 | return 0; |
| 444 | |
| 445 | memset(&paging_params, 0, sizeof(paging_params)); |
| 446 | osmo_strlcpy(paging_params.imsi, vsub->imsi, sizeof(paging_params.imsi)); |
| 447 | osmo_strlcpy(paging_params.vlr_name, mme->sgs->cfg.vlr_name, sizeof(paging_params.vlr_name)); |
| 448 | paging_params.serv_ind = serv_ind; |
| 449 | if (vsub->conf_by_radio_contact_ind == true) { |
| 450 | memcpy(&paging_params.lai, &vsub->sgs.lai, sizeof(paging_params.lai)); |
| 451 | paging_params.lai_present = true; |
| 452 | } |
| 453 | resp = gsm29118_create_paging_req(&paging_params); |
| 454 | sgs_tx(mme->conn, resp); |
| 455 | |
| 456 | /* FIXME: If we are in SGS_UE_ST_NULL while sub->conf_by_radio_contact_ind == false, |
| 457 | * we are supposed to start a search procedure as defined in 3GPP TS 23.018 */ |
| 458 | |
| 459 | /* Inform the VLR that a paging via SGs is in progress */ |
| 460 | vlr_sgs_pag(vsub, serv_ind); |
| 461 | |
| 462 | /* Return a page count of 1 (success) */ |
| 463 | return 1; |
| 464 | } |
| 465 | |
| 466 | /*********************************************************************** |
| 467 | * SGs incoming messages from the MME |
| 468 | ***********************************************************************/ |
| 469 | |
| 470 | /* Safely read out the SGs cause code from a given message/tlv set, send status |
| 471 | * message in case the cause code is invalid or missing. */ |
| 472 | static int sgs_cause_from_msg(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, |
| 473 | const char *imsi) |
| 474 | { |
| 475 | enum sgsap_sgs_cause cause; |
| 476 | const uint8_t *cause_ptr; |
| 477 | cause_ptr = TLVP_VAL_MINLEN(tp, SGSAP_IE_SGS_CAUSE, 1); |
| 478 | if (!cause_ptr) { |
| 479 | sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_SGS_CAUSE); |
| 480 | return -1; |
| 481 | } else |
| 482 | cause = *cause_ptr; |
| 483 | return cause; |
| 484 | } |
| 485 | |
| 486 | /* SGsAP-STATUS 3GPP TS 29.118, chapter 8.18 */ |
| 487 | static int sgs_rx_status(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, const char *imsi) |
| 488 | { |
| 489 | int cause; |
| 490 | const uint8_t *err_msg; |
| 491 | const char *imsi_ptr; |
| 492 | char *err_msg_hex = "(none)"; |
| 493 | |
| 494 | cause = sgs_cause_from_msg(sgc, msg, tp, NULL); |
| 495 | if (cause < 0) |
| 496 | return 0; |
| 497 | |
| 498 | if (imsi[0] != '\0') |
| 499 | imsi_ptr = imsi; |
| 500 | else |
| 501 | imsi_ptr = "<none>"; |
| 502 | |
| 503 | if (TLVP_PRESENT(tp, SGSAP_IE_ERR_MSG)) |
| 504 | err_msg = TLVP_VAL(tp, SGSAP_IE_ERR_MSG); |
| 505 | else |
| 506 | err_msg = NULL; |
| 507 | |
| 508 | if (err_msg) |
| 509 | err_msg_hex = osmo_hexdump(err_msg, TLVP_LEN(tp, SGSAP_IE_ERR_MSG)); |
| 510 | |
| 511 | LOGSGC(sgc, LOGL_NOTICE, "Rx STATUS cause=%s, IMSI=%s, err_msg=%s\n", |
| 512 | sgsap_sgs_cause_name(cause), imsi_ptr, err_msg_hex); |
| 513 | |
| 514 | return 0; |
| 515 | } |
| 516 | |
| 517 | /* SGsAP-RESET-INDICATION 3GPP TS 29.118, chapter 8.16 */ |
| 518 | static int sgs_rx_reset_ind(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp) |
| 519 | { |
| 520 | struct gsm29118_reset_msg reset_params; |
| 521 | struct msgb *resp; |
| 522 | |
| 523 | memset(&reset_params, 0, sizeof(reset_params)); |
| 524 | osmo_strlcpy(reset_params.vlr_name, sgc->sgs->cfg.vlr_name, sizeof(reset_params.vlr_name)); |
| 525 | reset_params.vlr_name_present = true; |
| 526 | |
| 527 | resp = gsm29118_create_reset_ack(&reset_params); |
| 528 | |
| 529 | /* Perform a reset of the SGS FSM of all subscribers that are present in the VLR */ |
| 530 | vlr_sgs_reset(gsm_network->vlr); |
| 531 | |
| 532 | sgs_tx(sgc, resp); |
| 533 | return 0; |
| 534 | } |
| 535 | |
| 536 | /* SGsAP-RESET-ACK 3GPP TS 29.118, chapter 8.15 */ |
| 537 | static int sgs_rx_reset_ack(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp) |
| 538 | { |
| 539 | /* dispatch event to VLR reset FSM for this MME */ |
| 540 | if (sgc->mme && sgc->mme->fi) |
| 541 | osmo_fsm_inst_dispatch(sgc->mme->fi, SGS_VLRR_E_RX_RESET_ACK, msg); |
| 542 | return 0; |
| 543 | } |
| 544 | |
| 545 | /* SGsAP-LOCATION-UPDATE-REQUEST 3GPP TS 29.118, chapter 8.11 */ |
| 546 | static int sgs_rx_loc_upd_req(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) |
| 547 | { |
| 548 | struct msgb *resp; |
| 549 | const uint8_t *lu_type_ie; |
| 550 | enum vlr_lu_type type; |
| 551 | struct osmo_location_area_id new_lai; |
| 552 | const struct gsm48_loc_area_id *gsm48_lai; |
| 553 | int rc; |
| 554 | char *mme_name; |
| 555 | struct vlr_sgs_cfg vlr_sgs_cfg; |
| 556 | struct vlr_subscr *vsub; |
| 557 | |
| 558 | /* Check for lingering connections */ |
| 559 | vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi); |
| 560 | if (vsub) { |
| 561 | subscr_conn_toss(vsub); |
| 562 | vlr_subscr_put(vsub); |
| 563 | } |
| 564 | |
| 565 | /* Determine MME-Name */ |
| 566 | mme_name = sgs_mme_fqdn_get(sgc); |
| 567 | if (!mme_name) { |
| 568 | resp = gsm29118_create_lu_rej(imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN, NULL); |
| 569 | sgs_tx(sgc, resp); |
| 570 | return 0; |
| 571 | } |
| 572 | |
| 573 | /* Parse LU-Type */ |
| 574 | lu_type_ie = TLVP_VAL_MINLEN(tp, SGSAP_IE_EPS_LU_TYPE, 1); |
| 575 | if (!lu_type_ie) |
| 576 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_EPS_LU_TYPE); |
| 577 | if (lu_type_ie[0] == 0x01) |
| 578 | type = VLR_LU_TYPE_IMSI_ATTACH; |
| 579 | else |
| 580 | type = VLR_LU_TYPE_REGULAR; |
| 581 | |
| 582 | /* Parse LAI of the new location */ |
| 583 | gsm48_lai = (struct gsm48_loc_area_id *)TLVP_VAL_MINLEN(tp, SGSAP_IE_LAI, 5); |
| 584 | if (!gsm48_lai) |
| 585 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_LAI); |
| 586 | gsm48_decode_lai2(gsm48_lai, &new_lai); |
| 587 | |
| 588 | /* Perform actual location update */ |
| 589 | memcpy(vlr_sgs_cfg.timer, sgc->sgs->cfg.timer, sizeof(vlr_sgs_cfg.timer)); |
| 590 | memcpy(vlr_sgs_cfg.counter, sgc->sgs->cfg.counter, sizeof(vlr_sgs_cfg.counter)); |
| 591 | rc = vlr_sgs_loc_update(gsm_network->vlr, &vlr_sgs_cfg, sgs_tx_loc_upd_resp_cb, sgs_iface_tx_paging, |
| 592 | sgs_tx_mm_info_cb, mme_name, type, imsi, &new_lai); |
| 593 | if (rc != 0) { |
| 594 | resp = gsm29118_create_lu_rej(imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN, NULL); |
| 595 | sgs_tx(sgc, resp); |
| 596 | } |
| 597 | |
| 598 | return 0; |
| 599 | } |
| 600 | |
| 601 | /* SGsAP-IMSI-DETACH-INDICATION 3GPP TS 29.118, chapter 8.8 */ |
| 602 | static int sgs_rx_imsi_det_ind(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) |
| 603 | { |
| 604 | struct msgb *resp; |
| 605 | enum sgsap_imsi_det_noneps_type type; |
| 606 | const uint8_t *type_ie; |
| 607 | |
| 608 | type_ie = TLVP_VAL_MINLEN(tp, SGSAP_IE_IMSI_DET_NONEPS_TYPE, 1); |
| 609 | if (!type_ie) |
| 610 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_IMSI_DET_NONEPS_TYPE); |
| 611 | |
| 612 | switch (type_ie[0]) { |
| 613 | case SGSAP_ID_NONEPS_T_EXPLICIT_UE_NONEPS: |
| 614 | type = SGSAP_ID_NONEPS_T_EXPLICIT_UE_NONEPS; |
| 615 | break; |
| 616 | case SGSAP_ID_NONEPS_T_COMBINED_UE_EPS_NONEPS: |
| 617 | type = SGSAP_ID_NONEPS_T_COMBINED_UE_EPS_NONEPS; |
| 618 | break; |
| 619 | case SGSAP_ID_NONEPS_T_IMPLICIT_UE_EPS_NONEPS: |
| 620 | type = SGSAP_ID_NONEPS_T_IMPLICIT_UE_EPS_NONEPS; |
| 621 | break; |
| 622 | default: |
| 623 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_INVALID_MAND_IE, msg, SGSAP_IE_IMSI_DET_NONEPS_TYPE); |
| 624 | break; |
| 625 | } |
| 626 | |
| 627 | vlr_sgs_imsi_detach(gsm_network->vlr, imsi, type); |
| 628 | resp = gsm29118_create_imsi_det_ack(imsi); |
| 629 | sgs_tx(sgc, resp); |
| 630 | |
| 631 | return 0; |
| 632 | } |
| 633 | |
| 634 | /* SGsAP-EPS-DETACH-INDICATION 3GPP TS 29.118, chapter 8.6 */ |
| 635 | static int sgs_rx_eps_det_ind(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) |
| 636 | { |
| 637 | struct msgb *resp; |
| 638 | enum sgsap_imsi_det_eps_type type; |
| 639 | const uint8_t *type_ie; |
| 640 | |
| 641 | type_ie = TLVP_VAL_MINLEN(tp, SGSAP_IE_IMSI_DET_EPS_TYPE, 1); |
| 642 | if (!type_ie) |
| 643 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_IMSI_DET_EPS_TYPE); |
| 644 | |
| 645 | switch (type_ie[0]) { |
| 646 | case SGSAP_ID_EPS_T_NETWORK_INITIATED: |
| 647 | type = SGSAP_ID_EPS_T_NETWORK_INITIATED; |
| 648 | break; |
| 649 | case SGSAP_ID_EPS_T_UE_INITIATED: |
| 650 | type = SGSAP_ID_EPS_T_UE_INITIATED; |
| 651 | break; |
| 652 | case SGSAP_ID_EPS_T_EPS_NOT_ALLOWED: |
| 653 | type = SGSAP_ID_EPS_T_EPS_NOT_ALLOWED; |
| 654 | break; |
| 655 | default: |
| 656 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_INVALID_MAND_IE, msg, SGSAP_IE_IMSI_DET_EPS_TYPE); |
| 657 | break; |
| 658 | } |
| 659 | |
| 660 | vlr_sgs_eps_detach(gsm_network->vlr, imsi, type); |
| 661 | resp = gsm29118_create_eps_det_ack(imsi); |
| 662 | sgs_tx(sgc, resp); |
| 663 | |
| 664 | return 0; |
| 665 | } |
| 666 | |
| 667 | /* SGsAP-PAGING-REJECT 3GPP TS 29.118, chapter 8.13 */ |
| 668 | static int sgs_rx_pag_rej(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) |
| 669 | { |
| 670 | int cause; |
| 671 | struct vlr_subscr *vsub; |
| 672 | |
| 673 | cause = sgs_cause_from_msg(sgc, msg, tp, NULL); |
| 674 | if (cause < 0) |
| 675 | return 0; |
| 676 | |
| 677 | /* Subscriber must be known by the VLR */ |
| 678 | vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi); |
| 679 | if (!vsub) |
| 680 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN, msg, SGSAP_IE_IMSI); |
| 681 | |
| 682 | /* Inform the VLR */ |
| 683 | vlr_sgs_pag_rej(gsm_network->vlr, imsi, cause); |
| 684 | |
| 685 | /* Stop all paging activity */ |
| 686 | subscr_paging_cancel(vsub, GSM_PAGING_EXPIRED); |
| 687 | |
| 688 | /* Depending on the cause code some action is required */ |
| 689 | if (cause == SGSAP_SGS_CAUSE_MT_CSFB_REJ_USER) { |
| 690 | /* FIXME: We are supposed to trigger a User Determined User Busy (UDUB) |
| 691 | * as specified in 3GPP TS 24.082 here, SGs association state shall not |
| 692 | * be changed */ |
| 693 | LOGSGC(sgc, LOGL_ERROR, |
| 694 | "Rx %s with SGSAP_SGS_CAUSE_MT_CSFB_REJ_USER, but sending UDUP is not implemented yet!\n", |
| 695 | sgsap_msg_type_name(msg->data[0])); |
| 696 | } else if (cause == SGSAP_SGS_CAUSE_IMSI_DET_EPS) { |
| 697 | /* FIXME: In this case we should send the paging via A/Iu interface */ |
| 698 | OSMO_ASSERT(false); |
| 699 | } |
| 700 | |
| 701 | vlr_subscr_put(vsub); |
| 702 | return 0; |
| 703 | } |
| 704 | |
| 705 | /* SGsAP-UE-UNREACHABLE 3GPP TS 29.118, chapter 8.21 */ |
| 706 | static int sgs_rx_ue_unr(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) |
| 707 | { |
| 708 | int cause; |
| 709 | |
| 710 | cause = sgs_cause_from_msg(sgc, msg, tp, NULL); |
| 711 | if (cause < 0) |
| 712 | return 0; |
| 713 | |
| 714 | vlr_sgs_ue_unr(gsm_network->vlr, imsi, cause); |
| 715 | |
| 716 | return 0; |
| 717 | } |
| 718 | |
| 719 | /* SGsAP-TMSI-REALLOCATION-COMPLETE 3GPP TS 29.118, chapter 8.19 */ |
| 720 | static int sgs_rx_tmsi_reall_cmpl(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) |
| 721 | { |
| 722 | vlr_sgs_tmsi_reall_compl(gsm_network->vlr, imsi); |
| 723 | return 0; |
| 724 | } |
| 725 | |
| 726 | /* SGsAP-SERVICE-REQUEST 3GPP TS 29.118, chapter 8.17 */ |
| 727 | static int sgs_rx_service_req(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) |
| 728 | { |
| 729 | enum sgsap_service_ind serv_ind; |
| 730 | const uint8_t *serv_ind_ie; |
| 731 | struct ran_conn *conn; |
| 732 | struct vlr_subscr *vsub; |
| 733 | |
| 734 | /* Note: While in other RAN concepts a service request is used to |
| 735 | * initiate mobile originated operation, the service request in SGsAP |
| 736 | * is comparable to a paging response. The SGsAP SERVICE REQUEST must |
| 737 | * not be confused or compared with a CM SERVICE REQUEST! */ |
| 738 | |
| 739 | if (!check_sgs_association(sgc, msg, imsi)) |
| 740 | return 0; |
| 741 | |
| 742 | vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi); |
| 743 | /* Note: vsub is already sufficiently verified by check_sgs_association(), |
| 744 | * we must have a vsub at this point! */ |
| 745 | OSMO_ASSERT(vsub); |
| 746 | |
| 747 | /* The Service request is intended as a paging response, if one is |
| 748 | * received while nothing is paging something is very wrong! */ |
| 749 | if (!vlr_sgs_pag_pend(vsub)) { |
| 750 | vlr_subscr_put(vsub); |
| 751 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MSG_INCOMP_STATE, msg, -1); |
| 752 | } |
| 753 | serv_ind_ie = TLVP_VAL_MINLEN(tp, SGSAP_IE_SERVICE_INDICATOR, 1); |
| 754 | |
| 755 | if (!serv_ind_ie) { |
| 756 | vlr_subscr_put(vsub); |
| 757 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_SERVICE_INDICATOR); |
| 758 | } |
| 759 | if (serv_ind_ie[0] == SGSAP_SERV_IND_CS_CALL) |
| 760 | serv_ind = serv_ind_ie[0]; |
| 761 | else if (serv_ind_ie[0] == SGSAP_SERV_IND_SMS) |
| 762 | serv_ind = serv_ind_ie[0]; |
| 763 | else { |
| 764 | vlr_subscr_put(vsub); |
| 765 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_INVALID_MAND_IE, msg, SGSAP_IE_SERVICE_INDICATOR); |
| 766 | } |
| 767 | |
| 768 | /* FIXME: The MME shall include an UE EMM Mode IE, but the field is |
| 769 | * marked optional. (Why do we need this info at all?) */ |
| 770 | |
| 771 | /* Report to the VLR that the paging has successfully completed */ |
| 772 | vlr_sgs_pag_ack(gsm_network->vlr, imsi); |
| 773 | |
| 774 | /* Exit early when the service indicator indicates that a call is being |
| 775 | * established. In those cases we do not allocate a connection, instead |
| 776 | * the connection will be allocated when the MS is appearing on the |
| 777 | * A-Interface. */ |
| 778 | if (serv_ind == SGSAP_SERV_IND_CS_CALL) { |
| 779 | vlr_subscr_put(vsub); |
| 780 | return 0; |
| 781 | } |
| 782 | |
| 783 | /* Allocate subscriber connection */ |
| 784 | conn = subscr_conn_allocate_sgs(sgc, vsub, true); |
| 785 | if (!conn) { |
| 786 | vlr_subscr_put(vsub); |
| 787 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MSG_INCOMP_STATE, msg, -1); |
| 788 | } |
| 789 | |
| 790 | return 0; |
| 791 | } |
| 792 | |
| 793 | /* SGsAP-UPLINK-UNITDATA 3GPP TS 29.118, chapter 8.22 */ |
| 794 | static int sgs_rx_ul_ud(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) |
| 795 | { |
| 796 | struct dtap_header *dtap; |
| 797 | struct ran_conn *conn; |
| 798 | bool ran_conn_created = false; |
| 799 | const uint8_t *nas_msg_container_ie; |
| 800 | struct vlr_subscr *vsub; |
| 801 | |
| 802 | if (!check_sgs_association(sgc, msg, imsi)) |
| 803 | return 0; |
| 804 | |
| 805 | vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi); |
| 806 | /* Note: vsub is already sufficiently verified by check_sgs_association(), |
| 807 | * we must have a vsub at this point! */ |
| 808 | OSMO_ASSERT(vsub); |
| 809 | |
| 810 | /* Try to find existing connection (MT) or allocate a new one (MO) */ |
| 811 | conn = connection_for_subscr(vsub); |
| 812 | if (!conn) { |
| 813 | conn = subscr_conn_allocate_sgs(sgc, vsub, false); |
| 814 | ran_conn_created = true; |
| 815 | } else { |
| 816 | if (conn->via_ran != OSMO_RAT_EUTRAN_SGS) { |
| 817 | LOGSGC(sgc, LOGL_ERROR, |
| 818 | "Receiving uplink unit-data for non-sgs connection -- discarding message!\n"); |
| 819 | msgb_free(msg); |
| 820 | return 0; |
| 821 | } |
| 822 | } |
| 823 | |
| 824 | /* If we do not find an existing connection and allocating a new one |
| 825 | * faild, give up and return status. */ |
| 826 | if (!conn) { |
| 827 | vlr_subscr_put(vsub); |
| 828 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MSG_INCOMP_STATE, msg, 0); |
| 829 | } |
| 830 | |
| 831 | nas_msg_container_ie = TLVP_VAL_MINLEN(tp, SGSAP_IE_NAS_MSG_CONTAINER, 1); |
| 832 | if (!nas_msg_container_ie) { |
| 833 | vlr_subscr_put(vsub); |
| 834 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_MISSING_MAND_IE, msg, SGSAP_IE_NAS_MSG_CONTAINER); |
| 835 | } |
| 836 | |
| 837 | /* ran_conn_dtap expects the dtap payload in l3h */ |
| 838 | dtap = (struct dtap_header *)nas_msg_container_ie; |
| 839 | msg->l3h = (uint8_t *) nas_msg_container_ie; |
| 840 | OMSC_LINKID_CB(msg) = dtap->link_id; |
| 841 | |
| 842 | /* Forward dtap payload into the msc */ |
| 843 | ran_conn_dtap(conn, msg); |
| 844 | |
| 845 | /* If we did not create the conn right here, we just handle the ref |
| 846 | * counting normally. Otherwise we are in the same role as |
| 847 | * sgs_rx_service_req() and we want that the refcount says incremented |
| 848 | * througout the lifetime of the newly created conn. */ |
| 849 | if (!ran_conn_created) |
| 850 | vlr_subscr_put(vsub); |
| 851 | return 0; |
| 852 | } |
| 853 | |
| 854 | /* SGsAP-MO-CSFB-INDICATION, chapter 8.25 */ |
| 855 | static int sgs_rx_csfb_ind(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) |
| 856 | { |
| 857 | struct vlr_subscr *vsub; |
| 858 | |
| 859 | /* The MME informs us with this message that the UE has returned back |
| 860 | * to the 4G network, so we use the SGs interface again for further |
| 861 | * communication with the UE. */ |
| 862 | |
| 863 | vsub = vlr_subscr_find_by_imsi(gsm_network->vlr, imsi); |
| 864 | if (!vsub) |
| 865 | return sgs_tx_status(sgc, imsi, SGSAP_SGS_CAUSE_IMSI_UNKNOWN, msg, SGSAP_IE_IMSI); |
| 866 | |
| 867 | /* Check for lingering connections */ |
| 868 | subscr_conn_toss(vsub); |
| 869 | |
| 870 | vsub->cs.attached_via_ran = OSMO_RAT_EUTRAN_SGS; |
| 871 | vlr_subscr_put(vsub); |
| 872 | return 0; |
| 873 | } |
| 874 | |
| 875 | /* SGsAP-UE-ACTIVITY-INDICATION, chapter 8.20 */ |
| 876 | static int sgs_rx_ue_act_ind(struct sgs_connection *sgc, struct msgb *msg, const struct tlv_parsed *tp, char *imsi) |
| 877 | { |
| 878 | /* In this MSC/VLR implementation we do not support the alerting |
| 879 | * procedure yet and therefore we will never request any alerting |
| 880 | * at the MME. Given that it is unlikely that we ever get activity |
| 881 | * indications from the MME, but if we do we should not act all too |
| 882 | * hostile and ignore the indication silently. */ |
| 883 | |
| 884 | LOGSGC(sgc, LOGL_ERROR, "Rx %s unexpected, we do not implement alerting yet, ignoring!\n", |
| 885 | sgsap_msg_type_name(msg->data[0])); |
| 886 | |
| 887 | return 0; |
| 888 | } |
| 889 | |
| 890 | #define TX_STATUS_AND_LOG(sgc, msg_type, cause, fmt) \ |
| 891 | LOGSGC(sgc, LOGL_ERROR, fmt, sgsap_msg_type_name(msg_type)); \ |
| 892 | resp = gsm29118_create_status(NULL, cause, msg); \ |
| 893 | sgs_tx(sgc, resp); \ |
| 894 | |
| 895 | /*! Process incoming SGs message (see sgs_server.c) |
| 896 | * \param[in] sgc related sgs connection |
| 897 | * \param[in] msg received message |
| 898 | * \returns 0 in case of success, -EINVAL in case of error. */ |
| 899 | int sgs_iface_rx(struct sgs_connection *sgc, struct msgb *msg) |
| 900 | { |
| 901 | struct msgb *resp; |
| 902 | uint8_t msg_type = msg->l2h[0]; |
| 903 | struct tlv_parsed tp; |
| 904 | int rc; |
| 905 | char imsi[GSM48_MI_SIZE]; |
| 906 | char mme_name[SGS_MME_NAME_LEN + 1]; |
| 907 | |
| 908 | memset(imsi, 0, sizeof(imsi)); |
| 909 | memset(mme_name, 0, sizeof(mme_name)); |
| 910 | |
| 911 | /* When the receiving entity receives a message that is too short to contain a complete |
| 912 | * message type information element, the receiving entity shall ignore that message. */ |
| 913 | if (msgb_l2len(msg) < 1) |
| 914 | goto error; |
| 915 | |
| 916 | /* Parse TLV elements */ |
| 917 | rc = tlv_parse(&tp, &sgsap_ie_tlvdef, msgb_l2(msg) + 1, msgb_l2len(msg) - 1, 0, 0); |
| 918 | if (rc < 0) { |
| 919 | TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_SEMANT_INCORR_MSG, "SGsAP Message %s parsing error\n"); |
| 920 | goto error; |
| 921 | } |
| 922 | |
| 923 | /* Most of the messages contain an IMSI as mandatory IE, parse it right here */ |
| 924 | if (!TLVP_PRESENT(&tp, SGSAP_IE_IMSI) && |
| 925 | msg_type != SGSAP_MSGT_STATUS && msg_type != SGSAP_MSGT_RESET_IND && msg_type != SGSAP_MSGT_RESET_ACK) { |
| 926 | /* reject the message; all but the three above have mandatory IMSI */ |
| 927 | TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_MISSING_MAND_IE, |
| 928 | "SGsAP Message %s without IMSI, dropping\n"); |
| 929 | goto error; |
| 930 | } |
| 931 | |
| 932 | if (TLVP_PRESENT(&tp, SGSAP_IE_IMSI)) { |
| 933 | gsm48_mi_to_string(imsi, sizeof(imsi), TLVP_VAL(&tp, SGSAP_IE_IMSI), TLVP_LEN(&tp, SGSAP_IE_IMSI)); |
| 934 | if (strlen(imsi) < GSM23003_IMSI_MIN_DIGITS) { |
| 935 | TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_INVALID_MAND_IE, |
| 936 | "SGsAP Message %s with short IMSI, dropping\n"); |
| 937 | goto error; |
| 938 | } |
| 939 | } |
| 940 | |
| 941 | /* Some messages contain an MME-NAME as mandatore IE, parse it right here. The |
| 942 | * MME-NAME is als immediately registered with the sgc, so it will be implicitly |
| 943 | * known to all functions that have access to the sgc context. */ |
| 944 | if (!TLVP_PRESENT(&tp, SGSAP_IE_MME_NAME) |
| 945 | && (msg_type == SGSAP_MSGT_RESET_IND || msg_type == SGSAP_MSGT_RESET_ACK |
| 946 | || msg_type == SGSAP_MSGT_LOC_UPD_REQ || msg_type == SGSAP_MSGT_IMSI_DET_IND |
| 947 | || msg_type == SGSAP_MSGT_EPS_DET_IND)) { |
| 948 | TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_MISSING_MAND_IE, |
| 949 | "SGsAP Message %s without MME-Name, dropping\n"); |
| 950 | goto error; |
| 951 | } |
| 952 | |
| 953 | if (TLVP_PRESENT(&tp, SGSAP_IE_MME_NAME)) { |
| 954 | if (decode_mme_name(mme_name, &tp) != 0) { |
| 955 | TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_INVALID_MAND_IE, |
| 956 | "SGsAP Message %s with invalid MME-Name, dropping\n"); |
| 957 | goto error; |
| 958 | } |
| 959 | /* Regsister/check mme_name with sgc */ |
| 960 | if (sgs_mme_fqdn_received(sgc, mme_name) < 0) { |
| 961 | TX_STATUS_AND_LOG(sgc, msg_type, SGSAP_SGS_CAUSE_MSG_INCOMP_STATE, |
| 962 | "SGsAP Message %s with invalid MME-Name, dropping\n"); |
| 963 | goto error; |
| 964 | } |
| 965 | } |
| 966 | |
| 967 | /* dispatch msg to various handler functions. msgb ownership remains here! */ |
| 968 | rc = -EINVAL; |
| 969 | switch (msg_type) { |
| 970 | case SGSAP_MSGT_STATUS: |
| 971 | rc = sgs_rx_status(sgc, msg, &tp, imsi); |
| 972 | break; |
| 973 | case SGSAP_MSGT_RESET_IND: |
| 974 | rc = sgs_rx_reset_ind(sgc, msg, &tp); |
| 975 | break; |
| 976 | case SGSAP_MSGT_RESET_ACK: |
| 977 | rc = sgs_rx_reset_ack(sgc, msg, &tp); |
| 978 | break; |
| 979 | case SGSAP_MSGT_LOC_UPD_REQ: |
| 980 | rc = sgs_rx_loc_upd_req(sgc, msg, &tp, imsi); |
| 981 | break; |
| 982 | case SGSAP_MSGT_IMSI_DET_IND: |
| 983 | rc = sgs_rx_imsi_det_ind(sgc, msg, &tp, imsi); |
| 984 | break; |
| 985 | case SGSAP_MSGT_EPS_DET_IND: |
| 986 | rc = sgs_rx_eps_det_ind(sgc, msg, &tp, imsi); |
| 987 | break; |
| 988 | case SGSAP_MSGT_PAGING_REJ: |
| 989 | rc = sgs_rx_pag_rej(sgc, msg, &tp, imsi); |
| 990 | break; |
| 991 | case SGSAP_MSGT_UE_UNREACHABLE: |
| 992 | rc = sgs_rx_ue_unr(sgc, msg, &tp, imsi); |
| 993 | break; |
| 994 | case SGSAP_MSGT_TMSI_REALL_CMPL: |
| 995 | rc = sgs_rx_tmsi_reall_cmpl(sgc, msg, &tp, imsi); |
| 996 | break; |
| 997 | case SGSAP_MSGT_SERVICE_REQ: |
| 998 | rc = sgs_rx_service_req(sgc, msg, &tp, imsi); |
| 999 | break; |
| 1000 | case SGSAP_MSGT_UL_UD: |
| 1001 | rc = sgs_rx_ul_ud(sgc, msg, &tp, imsi); |
| 1002 | break; |
| 1003 | case SGSAP_MSGT_MO_CSFB_IND: |
| 1004 | rc = sgs_rx_csfb_ind(sgc, msg, &tp, imsi); |
| 1005 | break; |
| 1006 | case SGSAP_MSGT_UE_ACT_IND: |
| 1007 | rc = sgs_rx_ue_act_ind(sgc, msg, &tp, imsi); |
| 1008 | break; |
| 1009 | case SGSAP_MSGT_ALERT_ACK: |
| 1010 | case SGSAP_MSGT_ALERT_REJ: |
| 1011 | LOGSGC(sgc, LOGL_ERROR, "Rx unmplemented SGsAP %s: %s\n", |
| 1012 | sgsap_msg_type_name(msg_type), msgb_hexdump(msg)); |
| 1013 | resp = gsm29118_create_status(imsi, SGSAP_SGS_CAUSE_MSG_UNKNOWN, msg); |
| 1014 | sgs_tx(sgc, resp); |
| 1015 | rc = 0; |
| 1016 | break; |
| 1017 | default: |
| 1018 | LOGSGC(sgc, LOGL_ERROR, "Rx unknown SGsAP message type 0x%02x: %s\n", msg_type, msgb_hexdump(msg)); |
| 1019 | resp = gsm29118_create_status(imsi, SGSAP_SGS_CAUSE_MSG_UNKNOWN, msg); |
| 1020 | sgs_tx(sgc, resp); |
| 1021 | rc = 0; |
| 1022 | break; |
| 1023 | } |
| 1024 | |
| 1025 | /* Catch unhandled errors */ |
| 1026 | if (rc < 0) { |
| 1027 | /* Note: Usually the sgs_rx_ should catch errors locally and |
| 1028 | * eimit a status message with proper cause code, including |
| 1029 | * a suitable log message. If we end up here, something is |
| 1030 | * not right and should be fixed */ |
| 1031 | LOGSGC(sgc, LOGL_ERROR, "Rx unable to decode SGsAP %s: %s\n", |
| 1032 | sgsap_msg_type_name(msg_type), msgb_hexdump(msg)); |
| 1033 | resp = gsm29118_create_status(imsi, SGSAP_SGS_CAUSE_MSG_UNKNOWN, msg); |
| 1034 | sgs_tx(sgc, resp); |
| 1035 | } |
| 1036 | |
| 1037 | error: |
| 1038 | msgb_free(msg); |
| 1039 | return 0; |
| 1040 | } |
| 1041 | |
| 1042 | /*********************************************************************** |
| 1043 | * SGs connection "VLR Reset Procedure" FSM |
| 1044 | ***********************************************************************/ |
| 1045 | |
| 1046 | static const struct value_string sgs_vlr_reset_fsm_event_names[] = { |
| 1047 | {SGS_VLRR_E_START_RESET, "START-RESET"}, |
| 1048 | {SGS_VLRR_E_RX_RESET_ACK, "RX-RESET-ACK"}, |
| 1049 | {0, NULL} |
| 1050 | }; |
| 1051 | |
| 1052 | static void sgs_vlr_reset_fsm_null(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 1053 | { |
| 1054 | switch (event) { |
| 1055 | case SGS_VLRR_E_RX_RESET_ACK: |
| 1056 | break; |
| 1057 | default: |
| 1058 | OSMO_ASSERT(0); |
| 1059 | break; |
| 1060 | } |
| 1061 | } |
| 1062 | |
| 1063 | static void sgs_vlr_reset_fsm_wait_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 1064 | { |
| 1065 | switch (event) { |
| 1066 | case SGS_VLRR_E_RX_RESET_ACK: |
| 1067 | osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_COMPLETE, 0, 0); |
| 1068 | break; |
| 1069 | default: |
| 1070 | OSMO_ASSERT(0); |
| 1071 | break; |
| 1072 | } |
| 1073 | } |
| 1074 | |
| 1075 | static void sgs_vlr_reset_fsm_complete(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 1076 | { |
| 1077 | switch (event) { |
| 1078 | case SGS_VLRR_E_RX_RESET_ACK: |
| 1079 | break; |
| 1080 | default: |
| 1081 | OSMO_ASSERT(0); |
| 1082 | break; |
| 1083 | } |
| 1084 | } |
| 1085 | |
| 1086 | static void sgs_vlr_reset_fsm_allstate(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 1087 | { |
| 1088 | struct msgb *reset_ind; |
| 1089 | struct gsm29118_reset_msg reset_params; |
| 1090 | struct sgs_mme_ctx *mme = (struct sgs_mme_ctx *)fi->priv; |
| 1091 | struct sgs_connection *sgc = mme->conn; |
| 1092 | struct sgs_state *sgs = mme->sgs; |
| 1093 | |
| 1094 | switch (event) { |
| 1095 | case SGS_VLRR_E_START_RESET: |
| 1096 | osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_NULL, 0, 0); |
| 1097 | mme->ns11_remaining = sgs->cfg.counter[SGS_STATE_NS11]; |
| 1098 | /* send a reset message and enter WAIT_ACK state */ |
| 1099 | memset(&reset_params, 0, sizeof(reset_params)); |
| 1100 | osmo_strlcpy(reset_params.vlr_name, sgs->cfg.vlr_name, sizeof(reset_params.vlr_name)); |
| 1101 | reset_params.vlr_name_present = true; |
| 1102 | reset_ind = gsm29118_create_reset_ind(&reset_params); |
| 1103 | sgs_tx(sgc, reset_ind); |
| 1104 | osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_WAIT_ACK, sgs->cfg.timer[SGS_STATE_TS11], 11); |
| 1105 | break; |
| 1106 | default: |
| 1107 | OSMO_ASSERT(0); |
| 1108 | break; |
| 1109 | } |
| 1110 | } |
| 1111 | |
| 1112 | static int sgs_vlr_reset_fsm_timer_cb(struct osmo_fsm_inst *fi) |
| 1113 | { |
| 1114 | struct msgb *reset_ind; |
| 1115 | struct gsm29118_reset_msg reset_params; |
| 1116 | struct sgs_mme_ctx *mme = (struct sgs_mme_ctx *)fi->priv; |
| 1117 | struct sgs_connection *sgc = mme->conn; |
| 1118 | struct sgs_state *sgs = mme->sgs; |
| 1119 | |
| 1120 | switch (fi->T) { |
| 1121 | case 11: |
| 1122 | if (mme->ns11_remaining >= 1) { |
| 1123 | memset(&reset_params, 0, sizeof(reset_params)); |
| 1124 | osmo_strlcpy(reset_params.vlr_name, sgs->cfg.vlr_name, sizeof(reset_params.vlr_name)); |
| 1125 | reset_params.vlr_name_present = true; |
| 1126 | reset_ind = gsm29118_create_reset_ind(&reset_params); |
| 1127 | sgs_tx(sgc, reset_ind); |
| 1128 | osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_WAIT_ACK, sgs->cfg.timer[SGS_STATE_TS11], 11); |
| 1129 | mme->ns11_remaining--; |
| 1130 | } else { |
| 1131 | LOGMME(mme, LOGL_ERROR, "Ts11 expired more than %u (Ns11) times, giving up\n", |
Vadim Yanitskiy | e9ef7c6 | 2019-02-23 16:04:17 +0700 | [diff] [blame] | 1132 | sgs->cfg.counter[SGS_STATE_NS11]); |
Harald Welte | 0df904d | 2018-12-03 11:00:04 +0100 | [diff] [blame] | 1133 | osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_NULL, 0, 0); |
| 1134 | } |
| 1135 | break; |
| 1136 | default: |
| 1137 | OSMO_ASSERT(0); |
| 1138 | break; |
| 1139 | } |
| 1140 | return 0; |
| 1141 | } |
| 1142 | |
| 1143 | static const struct osmo_fsm_state sgs_vlr_reset_fsm_states[] = { |
| 1144 | [SGS_VLRR_ST_NULL] = { |
| 1145 | /* We haven't even tried yet to send a RESET */ |
| 1146 | .name = "NULL", |
| 1147 | .action = sgs_vlr_reset_fsm_null, |
| 1148 | .in_event_mask = S(SGS_VLRR_E_RX_RESET_ACK), |
| 1149 | .out_state_mask = S(SGS_VLRR_ST_NULL) | S(SGS_VLRR_ST_WAIT_ACK), |
| 1150 | }, |
| 1151 | [SGS_VLRR_ST_WAIT_ACK] = { |
| 1152 | /* We're waiting for a SGsAP_RESET_ACK */ |
| 1153 | .name = "WAIT-ACK", |
| 1154 | .action = sgs_vlr_reset_fsm_wait_ack, |
| 1155 | .in_event_mask = S(SGS_VLRR_E_RX_RESET_ACK), |
| 1156 | .out_state_mask = S(SGS_VLRR_ST_NULL) | |
| 1157 | S(SGS_VLRR_ST_COMPLETE) | S(SGS_VLRR_ST_WAIT_ACK), |
| 1158 | }, |
| 1159 | [SGS_VLRR_ST_COMPLETE] = { |
| 1160 | /* Reset procedure to this MME has been completed */ |
| 1161 | .name = "COMPLETE", |
| 1162 | .action = sgs_vlr_reset_fsm_complete, |
| 1163 | .in_event_mask = S(SGS_VLRR_E_RX_RESET_ACK), |
| 1164 | .out_state_mask = S(SGS_VLRR_ST_NULL) | S(SGS_VLRR_ST_COMPLETE), |
| 1165 | }, |
| 1166 | }; |
| 1167 | |
| 1168 | static struct osmo_fsm sgs_vlr_reset_fsm = { |
| 1169 | .name = "SGs-VLR-RESET", |
| 1170 | .states = sgs_vlr_reset_fsm_states, |
| 1171 | .allstate_event_mask = S(SGS_VLRR_E_START_RESET), |
| 1172 | .allstate_action = sgs_vlr_reset_fsm_allstate, |
| 1173 | .timer_cb = sgs_vlr_reset_fsm_timer_cb, |
| 1174 | .log_subsys = DSGS, |
| 1175 | .event_names = sgs_vlr_reset_fsm_event_names, |
| 1176 | }; |
| 1177 | |
| 1178 | /*! Send unit-data through SGs interface (see msc_ifaces.c) |
| 1179 | * \param[in] msg layer 3 message to send. |
| 1180 | * \returns 0 in case of success, -EINVAL in case of error. */ |
| 1181 | int sgs_iface_tx_dtap_ud(struct msgb *msg) |
| 1182 | { |
| 1183 | struct ran_conn *conn; |
| 1184 | struct vlr_subscr *vsub; |
| 1185 | struct msgb *msg_sgs; |
| 1186 | struct sgs_mme_ctx *mme; |
| 1187 | int rc = -EINVAL; |
| 1188 | |
| 1189 | /* This function expects a pointer to the related gsm subscriber |
| 1190 | * connection (conn) in msg->dst. Also conn->vsub must point to |
| 1191 | * the related subscriber */ |
| 1192 | |
| 1193 | OSMO_ASSERT(msg->dst); |
| 1194 | conn = msg->dst; |
| 1195 | OSMO_ASSERT(conn->vsub); |
| 1196 | vsub = conn->vsub; |
| 1197 | |
| 1198 | mme = sgs_mme_ctx_by_vsub(vsub, SGSAP_MSGT_DL_UD); |
| 1199 | if (!mme) |
| 1200 | goto error; |
| 1201 | |
| 1202 | /* Make sure the subscriber has a valid SGs association, otherwise |
| 1203 | * don't let unit-data through. */ |
| 1204 | if (vsub->sgs_fsm->state != SGS_UE_ST_ASSOCIATED) { |
| 1205 | LOG_RAN_CONN(conn, LOGL_NOTICE, "Tx %s subscriber not SGs-associated, dropping\n", |
| 1206 | sgsap_msg_type_name(SGSAP_MSGT_DL_UD)); |
| 1207 | goto error; |
| 1208 | } |
| 1209 | |
| 1210 | msg_sgs = gsm29118_create_dl_ud(vsub->imsi, msg); |
| 1211 | sgs_tx(mme->conn, msg_sgs); |
| 1212 | rc = 0; |
| 1213 | |
| 1214 | error: |
| 1215 | msgb_free(msg); |
| 1216 | return rc; |
| 1217 | } |
| 1218 | |
| 1219 | /*! Send a relase message through SGs interface (see msc_ifaces.c) |
| 1220 | * \param[in] msg layer 3 message to send. |
| 1221 | * \returns 0 in case of success, -EINVAL in case of error. */ |
| 1222 | void sgs_iface_tx_release(struct ran_conn *conn) |
| 1223 | { |
| 1224 | struct msgb *msg_sgs; |
| 1225 | struct vlr_subscr *vsub; |
| 1226 | struct sgs_mme_ctx *mme; |
| 1227 | |
| 1228 | /*! Use this function to release an SGs connection normally |
| 1229 | * (cause code is 0). This function also automatically causes |
| 1230 | * the VLR subscriber usage to be balanced. */ |
| 1231 | |
| 1232 | OSMO_ASSERT(conn->vsub); |
| 1233 | vsub = conn->vsub; |
| 1234 | |
| 1235 | mme = sgs_mme_ctx_by_vsub(vsub, SGSAP_MSGT_DL_UD); |
| 1236 | if (!mme) |
| 1237 | return; |
| 1238 | |
| 1239 | msg_sgs = gsm29118_create_release_req(vsub->imsi, 0); |
| 1240 | sgs_tx(mme->conn, msg_sgs); |
| 1241 | } |
| 1242 | |
| 1243 | /*! initalize SGs new interface |
| 1244 | * \param[in] ctx talloc context |
| 1245 | * \param[in] network associated gsm network |
| 1246 | * \returns returns allocated sgs_stae, NULL in case of error. */ |
| 1247 | struct sgs_state *sgs_iface_init(void *ctx, struct gsm_network *network) |
| 1248 | { |
| 1249 | struct sgs_state *sgs; |
| 1250 | |
| 1251 | gsm_network = network; |
| 1252 | |
| 1253 | sgs = sgs_server_alloc(ctx); |
| 1254 | OSMO_ASSERT(sgs); |
| 1255 | |
| 1256 | /* We currently only support one SGs instance */ |
| 1257 | if (g_sgs) |
| 1258 | return NULL; |
| 1259 | g_sgs = sgs; |
| 1260 | |
Harald Welte | 0df904d | 2018-12-03 11:00:04 +0100 | [diff] [blame] | 1261 | return sgs; |
| 1262 | } |
Vadim Yanitskiy | 4eaefc2 | 2019-03-21 20:55:19 +0700 | [diff] [blame] | 1263 | |
| 1264 | static __attribute__((constructor)) void on_dso_load(void) |
| 1265 | { |
| 1266 | OSMO_ASSERT(osmo_fsm_register(&sgs_vlr_reset_fsm) == 0); |
| 1267 | } |