/* GSM Mobile Radio Interface Layer 3 messages on the A-bis interface * 3GPP TS 04.08 version 7.21.0 Release 1998 / ETSI TS 100 940 V7.21.0 */ /* (C) 2009-2015 by Harald Welte * (C) 2010 by On-Waves * * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see . * */ #include #include #include #include #include #include #include #include #include "config.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define PTMSI_ALLOC /* Our implementation, should be kept in SGSN */ static void mmctx_timer_cb(void *_mm); static void mmctx_timer_start(struct sgsn_mm_ctx *mm, unsigned int T) { unsigned long seconds; if (osmo_timer_pending(&mm->timer)) LOGMMCTXP(LOGL_ERROR, mm, "Starting MM timer %u while old " "timer %u pending\n", T, mm->T); seconds = osmo_tdef_get(sgsn->cfg.T_defs, T, OSMO_TDEF_S, -1); mm->T = T; mm->num_T_exp = 0; /* FIXME: we should do this only once ? */ osmo_timer_setup(&mm->timer, mmctx_timer_cb, mm); osmo_timer_schedule(&mm->timer, seconds, 0); } static void mmctx_timer_stop(struct sgsn_mm_ctx *mm, unsigned int T) { if (!osmo_timer_pending(&mm->timer)) { LOGMMCTXP(LOGL_NOTICE, mm, "Stopping *inactive* MM timer %u\n", T); return; } if (mm->T != T) { LOGMMCTXP(LOGL_ERROR, mm, "Stopping MM timer %u but " "%u is running\n", T, mm->T); } osmo_timer_del(&mm->timer); } time_t gprs_max_time_to_idle(void) { unsigned long T3314, T3312; T3314 = osmo_tdef_get(sgsn->cfg.T_defs, 3314, OSMO_TDEF_S, -1); T3312 = osmo_tdef_get(sgsn->cfg.T_defs, 3312, OSMO_TDEF_S, -1); return T3314 + (T3312 + 4 * 60); } /* Send a message through the underlying layer. * For param encryptable, see 3GPP TS 24.008 § 4.7.1.2 and * gsm48_hdr_gmm_cipherable(). Pass false for not cipherable messages. */ int gsm48_gmm_sendmsg(struct msgb *msg, int command, struct sgsn_mm_ctx *mm, bool encryptable) { if (mm) { rate_ctr_inc(rate_ctr_group_get_ctr(mm->ctrg, GMM_CTR_PKTS_SIG_OUT)); #ifdef BUILD_IU if (mm->ran_type == MM_CTX_T_UTRAN_Iu) return sgsn_ranap_iu_tx(msg, GPRS_SAPI_GMM); #endif } #ifdef BUILD_IU if (MSG_IU_UE_CTX(msg)) return sgsn_ranap_iu_tx(msg, GPRS_SAPI_GMM); #endif /* caller needs to provide TLLI, BVCI and NSEI */ return gprs_llc_tx_ui(msg, GPRS_SAPI_GMM, command, mm, encryptable); } /* copy identifiers from old message to new message, this * is required so lower layers can route it correctly */ static void gmm_copy_id(struct msgb *msg, const struct msgb *old) { msgb_tlli(msg) = msgb_tlli(old); msgb_bvci(msg) = msgb_bvci(old); msgb_nsei(msg) = msgb_nsei(old); MSG_IU_UE_CTX_SET(msg, MSG_IU_UE_CTX(old)); } /* Store BVCI/NSEI in MM context */ void msgid2mmctx(struct sgsn_mm_ctx *mm, const struct msgb *msg) { /* check for Iu or Gb */ if (!MSG_IU_UE_CTX(msg)) { mm->gb.bvci = msgb_bvci(msg); mm->gb.nsei = msgb_nsei(msg); } #ifdef BUILD_IU else { /* In case a Iu connection is reconnected we need to update the ue ctx */ /* FIXME: the old ue_ctx have to be freed/disconnected */ mm->iu.ue_ctx = MSG_IU_UE_CTX(msg); if (mm->ran_type == MM_CTX_T_UTRAN_Iu && mm->iu.ue_ctx) { mm->iu.ue_ctx->rab_assign_addr_enc = sgsn->cfg.iu.rab_assign_addr_enc; } } #endif } /* Store BVCI/NSEI in MM context */ void mmctx2msgid(struct msgb *msg, const struct sgsn_mm_ctx *mm) { msgb_tlli(msg) = mm->gb.tlli; msgb_bvci(msg) = mm->gb.bvci; msgb_nsei(msg) = mm->gb.nsei; MSG_IU_UE_CTX_SET(msg, mm->iu.ue_ctx); } static void mm_ctx_cleanup_free(struct sgsn_mm_ctx *ctx, const char *log_text) { LOGMMCTXP(LOGL_INFO, ctx, "Cleaning MM context due to %s\n", log_text); /* Mark MM state as deregistered */ osmo_fsm_inst_dispatch(ctx->gmm_fsm, E_GMM_CLEANUP, NULL); switch(ctx->ran_type) { case MM_CTX_T_UTRAN_Iu: osmo_fsm_inst_dispatch(ctx->iu.mm_state_fsm, E_PMM_PS_DETACH, NULL); break; case MM_CTX_T_GERAN_Gb: osmo_fsm_inst_dispatch(ctx->gb.mm_state_fsm, E_MM_GPRS_DETACH, NULL); break; } sgsn_mm_ctx_cleanup_free(ctx); } /* 3GPP TS 24.008 § 10.5.7.1 Process PDP context status value, bit 0 corresponds to nsapi 0 */ static void process_ms_ctx_status(struct sgsn_mm_ctx *mmctx, uint16_t pdp_status) { struct sgsn_pdp_ctx *pdp, *pdp2; /* 24.008 4.7.5.1.3: If the PDP context status information element is * included in ROUTING AREA UPDATE REQUEST message, then the network * shall deactivate all those PDP contexts locally (without peer to * peer signalling between the MS and the network), which are not in SM * state PDP-INACTIVE on network side but are indicated by the MS as * being in state PDP-INACTIVE. */ /* NSAPI 0 - 4 are spare, ignore these */ pdp_status &= 0xffe0; llist_for_each_entry_safe(pdp, pdp2, &mmctx->pdp_list, list) { bool active = (pdp_status & (1 << pdp->nsapi)); if (active) continue; LOGMMCTXP(LOGL_NOTICE, mmctx, "Dropping PDP context for NSAPI=%u " "due to PDP CTX STATUS IE=0x%02x\n", pdp->nsapi, pdp_status); pdp->ue_pdp_active = false; if (pdp->ggsn) sgsn_delete_pdp_ctx(pdp); else /* GTP side already detached, freeing */ sgsn_pdp_ctx_free(pdp); } } /* 3GPP TS 24.008 § 10.5.7.1 Encode PDP context status value, bit 0 correspond to nsapi 0 */ uint16_t encode_ms_ctx_status(struct sgsn_mm_ctx *mmctx) { struct sgsn_pdp_ctx *pdp; uint16_t pdp_status = 0; llist_for_each_entry(pdp, &mmctx->pdp_list, list) { if (pdp->ue_pdp_active) pdp_status |= (1 << pdp->nsapi); } return pdp_status; } /* 3GPP TS 24.008 § 4.7.13.4/10.5.7.1 Service request procedure not accepted by the * network. Returns true if MS has active PDP contexts in pdp_status */ bool pdp_status_has_active_nsapis(uint16_t pdp_status) { /* NSAPI 0 - 4 are spare and should be ignored 0 */ return (pdp_status >> 5) != 0; } /* Chapter 9.4.18 */ static int _tx_status(struct msgb *msg, uint8_t cause, struct sgsn_mm_ctx *mmctx) { struct gsm48_hdr *gh; /* MMCTX might be NULL! */ DEBUGP(DMM, "<- GMM STATUS (cause: %s)\n", get_value_string(gsm48_gmm_cause_names, cause)); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_STATUS; gh->data[0] = cause; return gsm48_gmm_sendmsg(msg, 0, mmctx, true); } static int gsm48_tx_gmm_status(struct sgsn_mm_ctx *mmctx, uint8_t cause) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 GMM STATUS"); mmctx2msgid(msg, mmctx); return _tx_status(msg, cause, mmctx); } static int _tx_detach_req(struct msgb *msg, uint8_t detach_type, uint8_t cause, struct sgsn_mm_ctx *mmctx) { struct gsm48_hdr *gh; /* MMCTX might be NULL! */ DEBUGP(DMM, "<- GMM DETACH REQ (type: %s, cause: %s)\n", get_value_string(gprs_det_t_mt_strs, detach_type), get_value_string(gsm48_gmm_cause_names, cause)); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_DETACH_REQ; gh->data[0] = detach_type & 0x07; msgb_tv_put(msg, GSM48_IE_GMM_CAUSE, cause); return gsm48_gmm_sendmsg(msg, 0, mmctx, true); } static int gsm48_tx_gmm_detach_req(struct sgsn_mm_ctx *mmctx, uint8_t detach_type, uint8_t cause) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 DET REQ"); mmctx2msgid(msg, mmctx); return _tx_detach_req(msg, detach_type, cause, mmctx); } static int gsm48_tx_gmm_detach_req_oldmsg(struct msgb *oldmsg, uint8_t detach_type, uint8_t cause) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 DET OLD"); gmm_copy_id(msg, oldmsg); return _tx_detach_req(msg, detach_type, cause, NULL); } /* Chapter 9.4.2: Attach accept */ int gsm48_tx_gmm_att_ack(struct sgsn_mm_ctx *mm) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 ATT ACK"); struct gsm48_hdr *gh; struct gsm48_attach_ack *aa; unsigned long t; #ifdef PTMSI_ALLOC struct osmo_mobile_identity mi; uint8_t *l; int rc; #endif #if 0 uint8_t *ptsig; #endif LOGMMCTXP(LOGL_INFO, mm, "<- GMM ATTACH ACCEPT (new P-TMSI=0x%08x)\n", mm->p_tmsi); rate_ctr_inc(rate_ctr_group_get_ctr(sgsn->rate_ctrs, CTR_GPRS_ATTACH_ACKED)); mmctx2msgid(msg, mm); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_ATTACH_ACK; aa = (struct gsm48_attach_ack *) msgb_put(msg, sizeof(*aa)); aa->force_stby = 0; /* not indicated */ aa->att_result = 1; /* GPRS only */ t = osmo_tdef_get(sgsn->cfg.T_defs, 3312, OSMO_TDEF_S, -1); aa->ra_upd_timer = gprs_secs_to_tmr_floor(t); aa->radio_prio = 0x44; /* lowest */ osmo_routing_area_id_encode_buf((uint8_t *) &aa->ra_id, sizeof(struct gsm48_ra_id), &mm->ra); #if 0 /* Optional: P-TMSI signature */ msgb_v_put(msg, GSM48_IE_GMM_PTMSI_SIG); ptsig = msgb_put(msg, 3); ptsig[0] = mm->p_tmsi_sig >> 16; ptsig[1] = mm->p_tmsi_sig >> 8; ptsig[2] = mm->p_tmsi_sig & 0xff; #endif /* Optional: Negotiated Ready timer value * (fixed 44s, default value, GSM 04.08, table 11.4a) to safely limit * the inactivity time READY->STANDBY. */ t = osmo_tdef_get(sgsn->cfg.T_defs, 3314, OSMO_TDEF_S, -1); msgb_tv_put(msg, GSM48_IE_GMM_TIMER_READY, gprs_secs_to_tmr_floor(t)); #ifdef PTMSI_ALLOC /* Optional: Allocated P-TMSI */ mi = (struct osmo_mobile_identity){ .type = GSM_MI_TYPE_TMSI, .tmsi = mm->p_tmsi, }; l = msgb_tl_put(msg, GSM48_IE_GMM_ALLOC_PTMSI); rc = osmo_mobile_identity_encode_msgb(msg, &mi, false); if (rc < 0) { LOGMMCTXP(LOGL_ERROR, mm, "Cannot encode Mobile Identity\n"); msgb_free(msg); return -EINVAL; } *l = rc; #endif /* Optional: MS-identity (combined attach) */ /* Optional: GMM cause (partial attach result for combined attach) */ /* Optional: Network feature support 10.5.5.23 */ /* msgb_v_put(msg, GSM48_IE_GMM_NET_FEAT_SUPPORT | 0x00);*/ return gsm48_gmm_sendmsg(msg, 0, mm, true); } /* Chapter 9.4.5: Attach reject */ static int _tx_gmm_att_rej(struct msgb *msg, uint8_t gmm_cause, const struct sgsn_mm_ctx *mm) { struct gsm48_hdr *gh; LOGMMCTXP(LOGL_NOTICE, mm, "<- GMM ATTACH REJECT: %s\n", get_value_string(gsm48_gmm_cause_names, gmm_cause)); rate_ctr_inc(rate_ctr_group_get_ctr(sgsn->rate_ctrs, CTR_GPRS_ATTACH_REJECTED)); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_ATTACH_REJ; gh->data[0] = gmm_cause; return gsm48_gmm_sendmsg(msg, 0, NULL, false); } static int gsm48_tx_gmm_att_rej_oldmsg(const struct msgb *old_msg, uint8_t gmm_cause) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 ATT REJ OLD"); gmm_copy_id(msg, old_msg); return _tx_gmm_att_rej(msg, gmm_cause, NULL); } int gsm48_tx_gmm_att_rej(struct sgsn_mm_ctx *mm, uint8_t gmm_cause) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 ATT REJ"); mmctx2msgid(msg, mm); return _tx_gmm_att_rej(msg, gmm_cause, mm); } /* Chapter 9.4.6.2 Detach accept */ static int _tx_detach_ack(struct msgb *msg, uint8_t force_stby, struct sgsn_mm_ctx *mm) { struct gsm48_hdr *gh; /* MMCTX might be NULL! */ DEBUGP(DMM, "<- GMM DETACH ACC (force-standby: %d)\n", force_stby); rate_ctr_inc(rate_ctr_group_get_ctr(sgsn->rate_ctrs, CTR_GPRS_DETACH_ACKED)); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_DETACH_ACK; gh->data[0] = force_stby; return gsm48_gmm_sendmsg(msg, 0, mm, true); } static int gsm48_tx_gmm_det_ack(struct sgsn_mm_ctx *mm, uint8_t force_stby) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 DET ACK"); mmctx2msgid(msg, mm); return _tx_detach_ack(msg, force_stby, mm); } static int gsm48_tx_gmm_det_ack_oldmsg(struct msgb *oldmsg, uint8_t force_stby) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 DET ACK OLD"); gmm_copy_id(msg, oldmsg); return _tx_detach_ack(msg, force_stby, NULL); } /* Transmit Chapter 9.4.12 Identity Request */ int gsm48_tx_gmm_id_req(struct sgsn_mm_ctx *mm, uint8_t id_type) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 ID REQ"); struct gsm48_hdr *gh; LOGMMCTXP(LOGL_DEBUG, mm, "<- GMM IDENTITY REQUEST: mi_type=%s\n", gsm48_mi_type_name(id_type)); mmctx2msgid(msg, mm); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_ID_REQ; /* 10.5.5.9 ID type 2 + identity type and 10.5.5.7 'force to standby' IE */ gh->data[0] = id_type & 0xf; return gsm48_gmm_sendmsg(msg, 1, mm, false); } static enum gprs_ciph_algo gprs_ms_net_select_best_gea(uint8_t net_mask, uint8_t ms_mask) { uint8_t common_mask = net_mask & ms_mask; uint8_t r = 0; while (common_mask >>= 1) { r++; } return r; } /* 3GPP TS 24.008 § 9.4.9: Authentication and Ciphering Request */ int gsm48_tx_gmm_auth_ciph_req(struct sgsn_mm_ctx *mm, const struct osmo_auth_vector *vec, uint8_t key_seq, bool force_standby) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 AUTH CIPH REQ"); struct gsm48_hdr *gh; struct gsm48_auth_ciph_req *acreq; uint8_t *m_rand, *m_cksn, rbyte; int rc; LOGMMCTXP(LOGL_INFO, mm, "<- GMM AUTH AND CIPHERING REQ (rand = %s," " mmctx_is_r99=%d, vec->auth_types=0x%x", osmo_hexdump(vec->rand, sizeof(vec->rand)), sgsn_mm_ctx_is_r99(mm), vec->auth_types); if (sgsn_mm_ctx_is_r99(mm) && vec && (vec->auth_types & OSMO_AUTH_TYPE_UMTS)) { LOGPC(DMM, LOGL_INFO, ", autn = %s)\n", osmo_hexdump(vec->autn, sizeof(vec->autn))); } else LOGPC(DMM, LOGL_INFO, ")\n"); mmctx2msgid(msg, mm); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_AUTH_CIPH_REQ; acreq = (struct gsm48_auth_ciph_req *) msgb_put(msg, sizeof(*acreq)); acreq->ciph_alg = mm->ciph_algo & 0xf; /* § 10.5.5.10: */ acreq->imeisv_req = 0x1; /* § 10.5.5.7: */ acreq->force_stby = force_standby; /* 3GPP TS 24.008 § 10.5.5.19: */ rc = osmo_get_rand_id(&rbyte, 1); if (rc < 0) { LOGMMCTXP(LOGL_ERROR, mm, "osmo_get_rand_id() failed for A&C ref: %s\n", strerror(-rc)); return rc; } acreq->ac_ref_nr = rbyte; mm->ac_ref_nr_used = acreq->ac_ref_nr; /* Only if authentication is requested we need to set RAND + CKSN */ if (vec) { m_rand = msgb_put(msg, sizeof(vec->rand) + 1); m_rand[0] = GSM48_IE_GMM_AUTH_RAND; memcpy(m_rand + 1, vec->rand, sizeof(vec->rand)); /* § 10.5.1.2: */ m_cksn = msgb_put(msg, 1); m_cksn[0] = (GSM48_IE_GMM_CIPH_CKSN << 4) | (key_seq & 0x07); /* A Release99 or higher MS/UE must be able to handle * the optional AUTN IE. If a classic GSM SIM is * inserted, it will simply ignore AUTN and just use * RAND */ if (sgsn_mm_ctx_is_r99(mm) && (vec->auth_types & OSMO_AUTH_TYPE_UMTS)) { msgb_tlv_put(msg, GSM48_IE_GMM_AUTN, sizeof(vec->autn), vec->autn); } } return gsm48_gmm_sendmsg(msg, 1, mm, false); } /* 3GPP TS 24.008 § 9.4.11: Authentication and Ciphering Reject */ static int gsm48_tx_gmm_auth_ciph_rej(struct sgsn_mm_ctx *mm) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 AUTH CIPH REJ"); struct gsm48_hdr *gh; LOGMMCTXP(LOGL_NOTICE, mm, "<- GMM AUTH AND CIPH REJECT\n"); mmctx2msgid(msg, mm); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_AUTH_CIPH_REJ; return gsm48_gmm_sendmsg(msg, 0, mm, false); } /* check if the received authentication response matches */ static enum osmo_sub_auth_type check_auth_resp(struct sgsn_mm_ctx *ctx, bool is_utran, const struct osmo_auth_vector *vec, const uint8_t *res, uint8_t res_len) { const uint8_t *expect_res; uint8_t expect_res_len; enum osmo_sub_auth_type expect_type; const char *expect_str; /* On UTRAN (3G) we always expect UMTS AKA. On GERAN (2G) we sent AUTN * and expect UMTS AKA if there is R99 capability and our vector * supports UMTS AKA, otherwise we expect GSM AKA. * However, on GERAN, even if we sent a UMTS AKA Authentication Request, the MS may decide to * instead reply with a GSM AKA SRES response. */ if (is_utran || (sgsn_mm_ctx_is_r99(ctx) && (vec->auth_types & OSMO_AUTH_TYPE_UMTS) && (res_len > sizeof(vec->sres)))) { expect_type = OSMO_AUTH_TYPE_UMTS; expect_str = "UMTS RES"; expect_res = vec->res; expect_res_len = vec->res_len; } else { expect_type = OSMO_AUTH_TYPE_GSM; expect_str = "GSM SRES"; expect_res = vec->sres; expect_res_len = sizeof(vec->sres); } if (!(vec->auth_types & expect_type)) { LOGMMCTXP(LOGL_ERROR, ctx, "Auth error: auth vector does" " not provide the expected auth type:" " expected %s = 0x%x, auth_types are 0x%x\n", expect_str, expect_type, vec->auth_types); return OSMO_AUTH_TYPE_NONE; } if (!res) goto auth_mismatch; if (res_len != expect_res_len) goto auth_mismatch; if (memcmp(res, expect_res, res_len) != 0) goto auth_mismatch; /* Authorized! */ return expect_type; auth_mismatch: LOGMMCTXP(LOGL_ERROR, ctx, "Auth mismatch: expected %s = %s\n", expect_str, osmo_hexdump_nospc(expect_res, expect_res_len)); return OSMO_AUTH_TYPE_NONE; } /* 3GPP TS 24.008 § 9.4.10: Authentication and Ciphering Response */ static int gsm48_rx_gmm_auth_ciph_resp(struct sgsn_mm_ctx *ctx, struct msgb *msg) { struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); struct gsm48_auth_ciph_resp *acr = (struct gsm48_auth_ciph_resp *)gh->data; struct osmo_mobile_identity mi; struct tlv_parsed tp; struct gsm_auth_tuple *at; const char *res_name = "(no response)"; uint8_t res[16]; uint8_t res_len; int rc; LOGMMCTXP(LOGL_INFO, ctx, "-> GMM AUTH AND CIPH RESPONSE\n"); if (ctx->auth_triplet.key_seq == GSM_KEY_SEQ_INVAL) { LOGMMCTXP(LOGL_NOTICE, ctx, "Unexpected Auth & Ciph Response (ignored)\n"); return 0; } if (acr->ac_ref_nr != ctx->ac_ref_nr_used) { LOGMMCTXP(LOGL_NOTICE, ctx, "Reference mismatch for Auth & Ciph" " Response: %u received, %u expected\n", acr->ac_ref_nr, ctx->ac_ref_nr_used); return 0; } /* Stop T3360 */ mmctx_timer_stop(ctx, 3360); tlv_parse(&tp, &gsm48_gmm_ie_tlvdef, acr->data, (msg->data + msg->len) - acr->data, 0, 0); if (!TLVP_PRESENT(&tp, GSM48_IE_GMM_AUTH_SRES) || !TLVP_PRESENT(&tp, GSM48_IE_GMM_IMEISV) || TLVP_LEN(&tp,GSM48_IE_GMM_AUTH_SRES) != 4) { /* TODO: missing mandatory IE, return STATUS or REJ? */ LOGMMCTXP(LOGL_ERROR, ctx, "Missing mandantory IE\n"); return -EINVAL; } /* IMEI SV parsing */ if (TLVP_LEN(&tp, GSM48_IE_GMM_IMEISV) != 9) { LOGMMCTXP(LOGL_ERROR, ctx, "-> GMM AUTH AND CIPH RESPONSE: Invalid IMEISV\n"); return -EINVAL; } /* FIXME: should we allow invalid IMEI SV? Are there phones which have broken SV in hex? */ if (osmo_mobile_identity_decode(&mi, TLVP_VAL(&tp, GSM48_IE_GMM_IMEISV), TLVP_LEN(&tp, GSM48_IE_GMM_IMEISV), false)) { LOGMMCTXP(LOGL_ERROR, ctx, "-> GMM AUTH AND CIPH RESPONSE: Cannot decode IMEISV\n"); return -EINVAL; } if (mi.type != GSM_MI_TYPE_IMEISV) { LOGMMCTXP(LOGL_ERROR, ctx, "-> GMM AUTH AND CIPH RESPONSE: Invalid MI type found in IMEISV %d\n", mi.type); return -EINVAL; } memcpy(&ctx->imei, mi.imeisv, ARRAY_SIZE(ctx->imei)); /* Start with the good old 4-byte SRES */ memcpy(res, TLVP_VAL(&tp, GSM48_IE_GMM_AUTH_SRES), 4); res_len = 4; res_name = "GSM SRES"; /* Append extended RES as part of UMTS AKA, if any */ if (TLVP_PRESENT(&tp, GSM48_IE_GMM_AUTH_RES_EXT)) { unsigned int l = TLVP_LEN(&tp, GSM48_IE_GMM_AUTH_RES_EXT); if (l > sizeof(res)-4) l = sizeof(res)-4; memcpy(res+4, TLVP_VAL(&tp, GSM48_IE_GMM_AUTH_RES_EXT), l); res_len += l; res_name = "UMTS RES"; } at = &ctx->auth_triplet; LOGMMCTXP(LOGL_DEBUG, ctx, "checking auth: received %s = %s\n", res_name, osmo_hexdump(res, res_len)); ctx->sec_ctx = check_auth_resp(ctx, false, &at->vec, res, res_len); if (!sgsn_mm_ctx_is_authenticated(ctx)) { rc = gsm48_tx_gmm_auth_ciph_rej(ctx); mm_ctx_cleanup_free(ctx, "GMM AUTH AND CIPH REJECT"); return rc; } if (ctx->ran_type == MM_CTX_T_UTRAN_Iu) ctx->iu.new_key = 1; /* FIXME: enable LLC cipheirng */ /* Check if we can let the mobile station enter */ return osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_AUTH_RESP_RECV_SUCCESS, NULL); } /* 3GPP TS 24.008 § 9.4.10: Authentication and Ciphering Failure */ static int gsm48_rx_gmm_auth_ciph_fail(struct sgsn_mm_ctx *ctx, struct msgb *msg) { struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); struct tlv_parsed tp; const uint8_t gmm_cause = gh->data[0]; const uint8_t *auts; int rc; LOGMMCTXP(LOGL_INFO, ctx, "-> GMM AUTH AND CIPH FAILURE (cause = %s)\n", get_value_string(gsm48_gmm_cause_names, gmm_cause)); tlv_parse(&tp, &gsm48_gmm_ie_tlvdef, gh->data+1, msg->len - 1, 0, 0); /* Only if GMM cause is present and the AUTS is provided, we can * start re-sync procedure */ if (gmm_cause == GMM_CAUSE_SYNC_FAIL && TLVP_PRESENT(&tp, GSM48_IE_GMM_AUTH_FAIL_PAR)) { if (TLVP_LEN(&tp, GSM48_IE_GMM_AUTH_FAIL_PAR) != 14) { LOGMMCTXP(LOGL_ERROR, ctx, "AUTS IE has wrong size:" " expected %d, got %u\n", 14, TLVP_LEN(&tp, GSM48_IE_GMM_AUTH_FAIL_PAR)); return -EINVAL; } auts = TLVP_VAL(&tp, GSM48_IE_GMM_AUTH_FAIL_PAR); LOGMMCTXP(LOGL_INFO, ctx, "R99 AUTHENTICATION SYNCH (AUTS = %s)\n", osmo_hexdump_nospc(auts, 14)); /* make sure we'll refresh the auth_triplet in * sgsn_auth_update() */ ctx->auth_triplet.key_seq = GSM_KEY_SEQ_INVAL; /* make sure we'll retry authentication after the resync */ ctx->auth_state = SGSN_AUTH_UMTS_RESYNC; /* Send AUTS to HLR and wait for new Auth Info Result */ rc = gprs_subscr_request_auth_info(ctx, auts, ctx->auth_triplet.vec.rand); if (!rc) return osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_AUTH_RESP_RECV_RESYNC, NULL); /* on error, fall through to send a reject */ LOGMMCTXP(LOGL_ERROR, ctx, "Sending AUTS to HLR failed (rc = %d)\n", rc); } LOGMMCTXP(LOGL_NOTICE, ctx, "Authentication failed\n"); rc = gsm48_tx_gmm_auth_ciph_rej(ctx); mm_ctx_cleanup_free(ctx, "GMM AUTH FAILURE"); return rc; } void extract_subscr_msisdn(struct sgsn_mm_ctx *ctx) { struct gsm_mncc_number called; uint8_t msisdn[sizeof(ctx->subscr->sgsn_data->msisdn) + 1]; /* Convert MSISDN from encoded to string.. */ if (!ctx->subscr) return; if (ctx->subscr->sgsn_data->msisdn_len < 1) return; /* prepare the data for the decoder */ memset(&called, 0, sizeof(called)); msisdn[0] = ctx->subscr->sgsn_data->msisdn_len; memcpy(&msisdn[1], ctx->subscr->sgsn_data->msisdn, ctx->subscr->sgsn_data->msisdn_len); /* decode the string now */ gsm48_decode_called(&called, msisdn); /* Prepend a '+' for international numbers */ if (called.plan == 1 && called.type == 1) { ctx->msisdn[0] = '+'; osmo_strlcpy(&ctx->msisdn[1], called.number, sizeof(ctx->msisdn)); } else { osmo_strlcpy(ctx->msisdn, called.number, sizeof(ctx->msisdn)); } } void extract_subscr_hlr(struct sgsn_mm_ctx *ctx) { struct gsm_mncc_number called; uint8_t hlr_number[sizeof(ctx->subscr->sgsn_data->hlr) + 1]; if (!ctx->subscr) return; if (ctx->subscr->sgsn_data->hlr_len < 1) return; /* prepare the data for the decoder */ memset(&called, 0, sizeof(called)); hlr_number[0] = ctx->subscr->sgsn_data->hlr_len; memcpy(&hlr_number[1], ctx->subscr->sgsn_data->hlr, ctx->subscr->sgsn_data->hlr_len); /* decode the string now */ gsm48_decode_called(&called, hlr_number); if (called.plan != 1) { LOGMMCTXP(LOGL_ERROR, ctx, "Numbering plan(%d) not allowed\n", called.plan); return; } if (called.type != 1) { LOGMMCTXP(LOGL_ERROR, ctx, "Numbering type(%d) not allowed\n", called.type); return; } osmo_strlcpy(ctx->hlr, called.number, sizeof(ctx->hlr)); } #ifdef BUILD_IU /* Chapter 9.4.21: Service accept */ static int gsm48_tx_gmm_service_ack(struct sgsn_mm_ctx *mm) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 SERVICE ACK"); struct gsm48_hdr *gh; LOGMMCTXP(LOGL_INFO, mm, "<- GMM SERVICE ACCEPT (P-TMSI=0x%08x)\n", mm->p_tmsi); mmctx2msgid(msg, mm); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_SERVICE_ACK; /* Optional: PDP context status */ /* Optional: MBMS context status */ return gsm48_gmm_sendmsg(msg, 0, mm, false); } #endif /* Chapter 9.4.22: Service reject */ static int _tx_gmm_service_rej(struct msgb *msg, uint8_t gmm_cause, const struct sgsn_mm_ctx *mm) { struct gsm48_hdr *gh; LOGMMCTXP(LOGL_NOTICE, mm, "<- GMM SERVICE REJECT: %s\n", get_value_string(gsm48_gmm_cause_names, gmm_cause)); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_SERVICE_REJ; gh->data[0] = gmm_cause; return gsm48_gmm_sendmsg(msg, 0, NULL, true); } static int gsm48_tx_gmm_service_rej_oldmsg(const struct msgb *old_msg, uint8_t gmm_cause) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 SERVICE REJ OLD"); gmm_copy_id(msg, old_msg); return _tx_gmm_service_rej(msg, gmm_cause, NULL); } #if 0 -- currently unused -- static int gsm48_tx_gmm_service_rej(struct sgsn_mm_ctx *mm, uint8_t gmm_cause) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 SERVICE REJ"); mmctx2msgid(msg, mm); return _tx_gmm_service_rej(msg, gmm_cause, mm); } #endif static int gsm48_tx_gmm_ra_upd_ack(struct sgsn_mm_ctx *mm); /* Check if we can already authorize a subscriber */ int gsm48_gmm_authorize(struct sgsn_mm_ctx *ctx) { #ifdef BUILD_IU int rc; #endif #ifndef PTMSI_ALLOC struct sgsn_signal_data sig_data; #endif /* Request IMSI and IMEI from the MS if they are unknown */ if (!strlen(ctx->imei)) { ctx->t3370_id_type = GSM_MI_TYPE_IMEI; mmctx_timer_start(ctx, 3370); return gsm48_tx_gmm_id_req(ctx, GSM_MI_TYPE_IMEI); } if (!strlen(ctx->imsi)) { ctx->t3370_id_type = GSM_MI_TYPE_IMSI; mmctx_timer_start(ctx, 3370); return gsm48_tx_gmm_id_req(ctx, GSM_MI_TYPE_IMSI); } /* All information required for authentication is available */ ctx->t3370_id_type = GSM_MI_TYPE_NONE; if (ctx->auth_state == SGSN_AUTH_UNKNOWN) { /* Request authorization, this leads to a call to * sgsn_auth_update which in turn calls * gsm0408_gprs_access_granted or gsm0408_gprs_access_denied */ sgsn_auth_request(ctx); /* Note that gsm48_gmm_authorize can be called recursively via * sgsn_auth_request iff ctx->auth_info changes to AUTH_ACCEPTED */ return 0; } if (ctx->auth_state == SGSN_AUTH_AUTHENTICATE && !sgsn_mm_ctx_is_authenticated(ctx)) { struct gsm_auth_tuple *at = &ctx->auth_triplet; mmctx_timer_start(ctx, 3360); return gsm48_tx_gmm_auth_ciph_req(ctx, &at->vec, at->key_seq, false); } if (ctx->auth_state == SGSN_AUTH_AUTHENTICATE && sgsn_mm_ctx_is_authenticated(ctx) && ctx->auth_triplet.key_seq != GSM_KEY_SEQ_INVAL) { /* Check again for authorization */ sgsn_auth_request(ctx); return 0; } if (ctx->auth_state != SGSN_AUTH_ACCEPTED) { LOGMMCTXP(LOGL_NOTICE, ctx, "authorization is denied, aborting procedure\n"); return -EACCES; } /* The MS is authorized */ #ifdef BUILD_IU if (ctx->ran_type == MM_CTX_T_UTRAN_Iu && !ctx->iu.ue_ctx->integrity_active) { /* Is any encryption above UEA0 enabled? */ bool send_ck = sgsn->cfg.uea_encryption_mask > (1 << OSMO_UTRAN_UEA0); LOGMMCTXP(LOGL_DEBUG, ctx, "Iu Security Mode Command: %s encryption key (UEA encryption mask = 0x%x)\n", send_ck ? "sending" : "not sending", sgsn->cfg.uea_encryption_mask); /* FIXME: we should send the set of allowed UEA, as in ranap_new_msg_sec_mod_cmd2(). However, this * is not possible in the iu_client API. See OS#5487. */ rc = sgsn_ranap_iu_tx_sec_mode_cmd(ctx->iu.ue_ctx, &ctx->auth_triplet.vec, send_ck, ctx->iu.new_key); ctx->iu.new_key = 0; return rc; } #endif switch (ctx->pending_req) { case 0: LOGMMCTXP(LOGL_INFO, ctx, "no pending request, authorization completed\n"); break; case GSM48_MT_GMM_ATTACH_REQ: ctx->pending_req = 0; extract_subscr_msisdn(ctx); extract_subscr_hlr(ctx); #ifdef PTMSI_ALLOC /* Start T3350 and re-transmit up to 5 times until ATTACH COMPLETE */ mmctx_timer_start(ctx, 3350); ctx->t3350_mode = GMM_T3350_MODE_ATT; #else memset(&sig_data, 0, sizeof(sig_data)); sig_data.mm = ctx; osmo_signal_dispatch(SS_SGSN, S_SGSN_ATTACH, &sig_data); osmo_fsm_inst_dispatch(ctx->gmm_fsm, E_GMM_ATTACH_SUCCESS, NULL); #endif return gsm48_tx_gmm_att_ack(ctx); #ifdef BUILD_IU case GSM48_MT_GMM_SERVICE_REQ: ctx->pending_req = 0; osmo_fsm_inst_dispatch(ctx->iu.mm_state_fsm, E_PMM_PS_CONN_ESTABLISH, NULL); rc = gsm48_tx_gmm_service_ack(ctx); if (ctx->iu.service.type != GPRS_SERVICE_T_SIGNALLING) sgsn_mm_ctx_iu_activate_rabs(ctx); return rc; #endif case GSM48_MT_GMM_RA_UPD_REQ: ctx->pending_req = 0; /* Send RA UPDATE ACCEPT */ return gsm48_tx_gmm_ra_upd_ack(ctx); default: LOGMMCTXP(LOGL_ERROR, ctx, "only Attach Request is supported yet, " "got request type %u\n", ctx->pending_req); break; } return 0; } void gsm0408_gprs_authenticate(struct sgsn_mm_ctx *ctx) { ctx->sec_ctx = OSMO_AUTH_TYPE_NONE; if (ctx->gmm_att_req.fsm->state != ST_INIT) osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_VLR_ANSWERED, (void *) 0); else gsm48_gmm_authorize(ctx); } void gsm0408_gprs_access_granted(struct sgsn_mm_ctx *ctx) { switch (ctx->gmm_fsm->state) { case ST_GMM_COMMON_PROC_INIT: LOGMMCTXP(LOGL_NOTICE, ctx, "Authorized, continuing procedure, IMSI=%s\n", ctx->imsi); /* Continue with the authorization */ if (ctx->gmm_att_req.fsm->state != ST_INIT) osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_VLR_ANSWERED, (void *) 0); break; default: LOGMMCTXP(LOGL_INFO, ctx, "Authorized, ignored, IMSI=%s\n", ctx->imsi); } } void gsm0408_gprs_access_denied(struct sgsn_mm_ctx *ctx, int gmm_cause) { if (gmm_cause == SGSN_ERROR_CAUSE_NONE) gmm_cause = GMM_CAUSE_GPRS_NOTALLOWED; switch (ctx->gmm_fsm->state) { case ST_GMM_COMMON_PROC_INIT: LOGMMCTXP(LOGL_NOTICE, ctx, "Not authorized, rejecting ATTACH REQUEST " "with cause '%s' (%d)\n", get_value_string(gsm48_gmm_cause_names, gmm_cause), gmm_cause); if (ctx->gmm_att_req.fsm->state != ST_INIT) osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_REJECT, (void *) (long) gmm_cause); break; case ST_GMM_REGISTERED_NORMAL: case ST_GMM_REGISTERED_SUSPENDED: LOGMMCTXP(LOGL_NOTICE, ctx, "Authorization lost, detaching " "with cause '%s' (%d)\n", get_value_string(gsm48_gmm_cause_names, gmm_cause), gmm_cause); gsm48_tx_gmm_detach_req( ctx, GPRS_DET_T_MT_IMSI, gmm_cause); mm_ctx_cleanup_free(ctx, "auth lost"); break; default: LOGMMCTXP(LOGL_INFO, ctx, "Authorization lost, cause is '%s' (%d)\n", get_value_string(gsm48_gmm_cause_names, gmm_cause), gmm_cause); mm_ctx_cleanup_free(ctx, "auth lost"); } } void gsm0408_gprs_access_cancelled(struct sgsn_mm_ctx *ctx, int gmm_cause) { if (gmm_cause != SGSN_ERROR_CAUSE_NONE) { LOGMMCTXP(LOGL_INFO, ctx, "Cancelled with cause '%s' (%d), deleting context\n", get_value_string(gsm48_gmm_cause_names, gmm_cause), gmm_cause); gsm0408_gprs_access_denied(ctx, gmm_cause); return; } LOGMMCTXP(LOGL_INFO, ctx, "Cancelled, deleting context silently\n"); mm_ctx_cleanup_free(ctx, "access cancelled"); } /* Parse Chapter 9.4.13 Identity Response */ static int gsm48_rx_gmm_id_resp(struct sgsn_mm_ctx *ctx, struct msgb *msg) { struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); long mi_typel; char mi_log_string[32]; struct osmo_mobile_identity mi; if (!ctx) { DEBUGP(DMM, "from unknown TLLI 0x%08x?!? This should not happen\n", msgb_tlli(msg)); return -EINVAL; } if (osmo_mobile_identity_decode(&mi, &gh->data[1], gh->data[0], false)) { LOGMMCTXP(LOGL_ERROR, ctx, "-> GMM IDENTITY RESPONSE: cannot decode Mobile Identity\n"); return -EINVAL; } osmo_mobile_identity_to_str_buf(mi_log_string, sizeof(mi_log_string), &mi); LOGMMCTXP(LOGL_DEBUG, ctx, "-> GMM IDENTITY RESPONSE: MI=%s\n", mi_log_string); if (ctx->t3370_id_type == GSM_MI_TYPE_NONE) { LOGMMCTXP(LOGL_NOTICE, ctx, "Got unexpected IDENTITY RESPONSE: MI=%s, " "ignoring message\n", mi_log_string); return -EINVAL; } if (mi.type == ctx->t3370_id_type) mmctx_timer_stop(ctx, 3370); switch (mi.type) { case GSM_MI_TYPE_IMSI: /* we already have a mm context with current TLLI, but no * P-TMSI / IMSI yet. What we now need to do is to fill * this initial context with data from the HLR */ if (strlen(ctx->imsi) == 0) { /* Check if we already have a MM context for this IMSI */ struct sgsn_mm_ctx *ictx; ictx = sgsn_mm_ctx_by_imsi(mi.imsi); if (ictx) { /* Handle it like in gsm48_rx_gmm_det_req, * except that no messages are sent to the BSS */ LOGMMCTXP(LOGL_NOTICE, ctx, "Deleting old MM Context for same IMSI " "p_tmsi_old=0x%08x\n", ictx->p_tmsi); mm_ctx_cleanup_free(ictx, "GMM IMSI re-use"); } } OSMO_STRLCPY_ARRAY(ctx->imsi, mi.imsi); break; case GSM_MI_TYPE_IMEI: OSMO_STRLCPY_ARRAY(ctx->imei, mi.imei); break; case GSM_MI_TYPE_IMEISV: break; } /* Check if we can let the mobile station enter */ mi_typel = mi.type; return osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_IDEN_RESP_RECV, (void *)mi_typel); } /* Allocate a new P-TMSI and change context state */ static inline void ptmsi_update(struct sgsn_mm_ctx *ctx) { uint32_t ptmsi; /* Don't change the P-TMSI if a P-TMSI re-assignment is under way */ if (ctx->gmm_fsm->state != ST_GMM_COMMON_PROC_INIT) { ptmsi = sgsn_alloc_ptmsi(); if (ptmsi != GSM_RESERVED_TMSI) { ctx->p_tmsi_old = ctx->p_tmsi; ctx->p_tmsi = ptmsi; } else LOGMMCTXP(LOGL_ERROR, ctx, "P-TMSI allocation failure: using old one.\n"); } osmo_fsm_inst_dispatch(ctx->gmm_fsm, E_GMM_COMMON_PROC_INIT_REQ, NULL); } /* Detect if RAT has changed */ static bool mmctx_did_rat_change(struct sgsn_mm_ctx *mmctx, struct msgb *msg) { if (MSG_IU_UE_CTX(msg) && mmctx->ran_type != MM_CTX_T_UTRAN_Iu) return true; if (!MSG_IU_UE_CTX(msg) && mmctx->ran_type != MM_CTX_T_GERAN_Gb) return true; return false; } /* Notify the FSM of a RAT change */ static void mmctx_handle_rat_change(struct sgsn_mm_ctx *mmctx, struct msgb *msg, struct gprs_llc_llme *llme) { struct gmm_rat_change_data rat_chg = { .llme = llme }; rat_chg.new_ran_type = MSG_IU_UE_CTX(msg) ? MM_CTX_T_UTRAN_Iu : MM_CTX_T_GERAN_Gb; if (rat_chg.new_ran_type != mmctx->ran_type) osmo_fsm_inst_dispatch(mmctx->gmm_fsm, E_GMM_RAT_CHANGE, (void *) &rat_chg); else LOGMMCTXP(LOGL_ERROR, mmctx, "RAT didn't change or not implemented (ran_type=%u, " "msg_iu_ue_ctx=%p\n", mmctx->ran_type, MSG_IU_UE_CTX(msg)); } static uint8_t gprs_ms_net_cap_gea_mask(const uint8_t *ms_net_cap, uint8_t cap_len) { uint8_t mask = (1 << GPRS_ALGO_GEA0); if (cap_len == 0) return mask; mask |= (0x80 & ms_net_cap[0]) ? (1 << GPRS_ALGO_GEA1) : 0; if (cap_len < 2) return mask; /* extended GEA bits start from 2nd bit of the next byte */ mask |= (0x40 & ms_net_cap[1]) ? (1 << GPRS_ALGO_GEA2) : 0; mask |= (0x20 & ms_net_cap[1]) ? (1 << GPRS_ALGO_GEA3) : 0; mask |= (0x10 & ms_net_cap[1]) ? (1 << GPRS_ALGO_GEA4) : 0; return mask; } /* 3GPP TS 24.008 § 9.4.1 Attach request */ static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *ctx, struct msgb *msg, struct gprs_llc_llme *llme) { struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); uint8_t *cur = gh->data, *msnc, *mi_data, *ms_ra_acc_cap; uint8_t msnc_len, att_type, mi_len, ms_ra_acc_cap_len; uint16_t drx_par; char mi_log_string[32]; struct osmo_routing_area_id rai; uint16_t cid = 0; enum gsm48_gmm_cause reject_cause; struct osmo_mobile_identity mi; int rc; LOGMMCTXP(LOGL_INFO, ctx, "-> GMM ATTACH REQUEST "); rate_ctr_inc(rate_ctr_group_get_ctr(sgsn->rate_ctrs, CTR_GPRS_ATTACH_REQUEST)); /* As per TS 04.08 Chapter 4.7.1.4, the attach request arrives either * with a foreign TLLI (P-TMSI that was allocated to the MS before), * or with random TLLI. */ if (!MSG_IU_UE_CTX(msg)) { /* Gb mode */ bssgp_parse_cell_id2(&rai, &cid, msgb_bcid(msg), 8); } else { #ifdef BUILD_IU gprs_rai_to_osmo(&rai, &MSG_IU_UE_CTX(msg)->ra_id); #else LOGMMCTXP(LOGL_ERROR, ctx, "Cannot handle Iu Attach Request, built without Iu support\n"); return -ENOTSUP; #endif } /* MS network capability 10.5.5.12 */ msnc_len = *cur++; msnc = cur; if (msnc_len > sizeof(ctx->ms_network_capa.buf)) goto err_inval; cur += msnc_len; /* TODO: In iu mode - handle follow-on request. * The follow-on request can be signaled in an Attach Request on IuPS. * This means the MS/UE asks to keep the PS connection open for further requests * after the Attach Request succeed. * The SGSN can decide if it close the connection or not. Both are spec conform. */ /* aTTACH Type 10.5.5.2 */ att_type = *cur++ & 0x07; /* DRX parameter 10.5.5.6 */ drx_par = *cur++ << 8; drx_par |= *cur++; /* Mobile Identity (P-TMSI or IMSI) 10.5.1.4 */ mi_len = *cur++; mi_data = cur; cur += mi_len; rc = osmo_mobile_identity_decode(&mi, mi_data, mi_len, false); if (rc) goto err_inval; osmo_mobile_identity_to_str_buf(mi_log_string, sizeof(mi_log_string), &mi); DEBUGPC(DMM, "MI(%s) type=\"%s\" ", mi_log_string, get_value_string(gprs_att_t_strs, att_type)); /* Old routing area identification 10.5.5.15. Skip it */ cur += 6; /* MS Radio Access Capability 10.5.5.12a */ ms_ra_acc_cap_len = *cur++; ms_ra_acc_cap = cur; if (ms_ra_acc_cap_len > sizeof(ctx->ms_radio_access_capa.buf)) goto err_inval; cur += ms_ra_acc_cap_len; LOGPC(DMM, LOGL_INFO, "\n"); /* Optional: Old P-TMSI Signature, Requested READY timer, TMSI Status */ switch (mi.type) { case GSM_MI_TYPE_IMSI: /* Try to find MM context based on IMSI */ if (!ctx) ctx = sgsn_mm_ctx_by_imsi(mi.imsi); if (!ctx) { if (MSG_IU_UE_CTX(msg)) ctx = sgsn_mm_ctx_alloc_iu(MSG_IU_UE_CTX(msg)); else ctx = sgsn_mm_ctx_alloc_gb(0, &rai); if (!ctx) { reject_cause = GMM_CAUSE_NET_FAIL; goto rejected; } OSMO_STRLCPY_ARRAY(ctx->imsi, mi.imsi); } break; case GSM_MI_TYPE_TMSI: /* Try to find MM context based on P-TMSI */ if (!ctx) ctx = sgsn_mm_ctx_by_ptmsi(mi.tmsi); if (!ctx) { /* Allocate a context as most of our code expects one. * Context will not have an IMSI ultil ID RESP is received */ if (MSG_IU_UE_CTX(msg)) ctx = sgsn_mm_ctx_alloc_iu(MSG_IU_UE_CTX(msg)); else ctx = sgsn_mm_ctx_alloc_gb(msgb_tlli(msg), &rai); if (!ctx) { reject_cause = GMM_CAUSE_NET_FAIL; goto rejected; } ctx->p_tmsi = mi.tmsi; } break; default: LOGMMCTXP(LOGL_NOTICE, ctx, "Rejecting ATTACH REQUEST with " "MI %s\n", mi_log_string); reject_cause = GMM_CAUSE_MS_ID_NOT_DERIVED; goto rejected; } if (mmctx_did_rat_change(ctx, msg)) mmctx_handle_rat_change(ctx, msg, llme); if (ctx->ran_type == MM_CTX_T_GERAN_Gb) { ctx->gb.tlli = msgb_tlli(msg); ctx->gb.llme = llme; } msgid2mmctx(ctx, msg); /* Update MM Context with currient RA and Cell ID */ ctx->ra = rai; if (ctx->ran_type == MM_CTX_T_GERAN_Gb) ctx->gb.cell_id = cid; /* Update MM Context with other data */ ctx->drx_parms = drx_par; ctx->ms_radio_access_capa.len = ms_ra_acc_cap_len; memcpy(ctx->ms_radio_access_capa.buf, ms_ra_acc_cap, ctx->ms_radio_access_capa.len); ctx->ms_network_capa.len = msnc_len; memcpy(ctx->ms_network_capa.buf, msnc, msnc_len); ctx->ue_cipher_mask = gprs_ms_net_cap_gea_mask(ctx->ms_network_capa.buf, msnc_len); if (!(ctx->ue_cipher_mask & sgsn->cfg.gea_encryption_mask)) { reject_cause = GMM_CAUSE_PROTO_ERR_UNSPEC; LOGMMCTXP(LOGL_NOTICE, ctx, "Rejecting ATTACH REQUEST with MI " "%s because MS do not support required encryption, mask UE:0x%02x NW:0x%02x \n", mi_log_string, ctx->ue_cipher_mask, sgsn->cfg.gea_encryption_mask); goto rejected; } /* just assume that everythig is fine if the phone offers a5/4: * it requires a valid umts security context which we can only have after * 1) IDENTITY REQUEST to know what to ask the HLR for * 2) and AUTHENTICATION AND CIPHERING REQUEST * ... but 2) already requires selecting a cipher mode. * So let's just assume we will have the auth data required to make it work. */ ctx->ciph_algo = gprs_ms_net_select_best_gea(ctx->ue_cipher_mask, sgsn->cfg.gea_encryption_mask); #ifdef PTMSI_ALLOC /* Allocate a new P-TMSI (+ P-TMSI signature) and update TLLI */ ptmsi_update(ctx); #endif if (ctx->ran_type == MM_CTX_T_GERAN_Gb) { /* Even if there is no P-TMSI allocated, the MS will * switch from foreign TLLI to local TLLI */ ctx->gb.tlli_new = gprs_tmsi2tlli(ctx->p_tmsi, TLLI_LOCAL); /* Inform LLC layer about new TLLI but keep old active */ if (sgsn_mm_ctx_is_authenticated(ctx)) gprs_llme_copy_key(ctx, ctx->gb.llme); gprs_llgmm_assign(ctx->gb.llme, ctx->gb.tlli, ctx->gb.tlli_new); } osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_ATTACH_REQ_RECV, msg); return 0; err_inval: LOGPC(DMM, LOGL_INFO, "\n"); reject_cause = GMM_CAUSE_SEM_INCORR_MSG; rejected: /* Send ATTACH REJECT */ LOGMMCTXP(LOGL_NOTICE, ctx, "Rejecting Attach Request with cause '%s' (%d)\n", get_value_string(gsm48_gmm_cause_names, reject_cause), reject_cause); rc = gsm48_tx_gmm_att_rej_oldmsg(msg, reject_cause); if (ctx) mm_ctx_cleanup_free(ctx, "GMM ATTACH REJ"); else if (llme) gprs_llgmm_unassign(llme); return rc; } /* 3GPP TS 24.008 § 9.4.3 Attach complete */ static int gsm48_rx_gmm_att_compl(struct sgsn_mm_ctx *mmctx) { struct sgsn_signal_data sig_data; /* only in case SGSN offered new P-TMSI */ LOGMMCTXP(LOGL_INFO, mmctx, "-> GMM ATTACH COMPLETE\n"); #ifdef BUILD_IU if (mmctx->iu.ue_ctx) { sgsn_ranap_iu_tx_release(mmctx->iu.ue_ctx, NULL); } #endif mmctx_timer_stop(mmctx, 3350); mmctx->t3350_mode = GMM_T3350_MODE_NONE; mmctx->p_tmsi_old = 0; mmctx->pending_req = 0; osmo_fsm_inst_dispatch(mmctx->gmm_fsm, E_GMM_ATTACH_SUCCESS, NULL); switch(mmctx->ran_type) { case MM_CTX_T_UTRAN_Iu: osmo_fsm_inst_dispatch(mmctx->iu.mm_state_fsm, E_PMM_PS_ATTACH, NULL); break; case MM_CTX_T_GERAN_Gb: /* Unassign the old TLLI */ mmctx->gb.tlli = mmctx->gb.tlli_new; gprs_llme_copy_key(mmctx, mmctx->gb.llme); gprs_llgmm_assign(mmctx->gb.llme, TLLI_UNASSIGNED, mmctx->gb.tlli_new); osmo_fsm_inst_dispatch(mmctx->gb.mm_state_fsm, E_MM_GPRS_ATTACH, NULL); break; } osmo_fsm_inst_dispatch(mmctx->gmm_att_req.fsm, E_ATTACH_COMPLETE_RECV, 0); memset(&sig_data, 0, sizeof(sig_data)); sig_data.mm = mmctx; osmo_signal_dispatch(SS_SGSN, S_SGSN_ATTACH, &sig_data); return 0; } /* Checks if two GMM are the same (required diffing Attach Requests/RAU Requests * return 0 if equal */ int gprs_gmm_msg_cmp(struct msgb *a, struct msgb *b) { struct gsm48_hdr *gh_a = (struct gsm48_hdr *) msgb_gmmh(a); struct gsm48_hdr *gh_b = (struct gsm48_hdr *) msgb_gmmh(b); if (msgb_l3len(a) != msgb_l3len(b)) return 2; return memcmp(gh_a, gh_b, msgb_l3len(a)); } /* 3GPP TS 24.008 § 4.7.4.1 / 9.4.5.2 MO Detach request */ static int gsm48_rx_gmm_det_req(struct sgsn_mm_ctx *ctx, struct msgb *msg) { struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); uint8_t detach_type, power_off; int rc = 0; detach_type = gh->data[0] & 0x7; power_off = gh->data[0] & 0x8; /* FIXME: In 24.008 there is an optional P-TMSI and P-TMSI signature IE */ rate_ctr_inc(rate_ctr_group_get_ctr(sgsn->rate_ctrs, CTR_GPRS_DETACH_REQUEST)); LOGMMCTXP(LOGL_INFO, ctx, "-> GMM DETACH REQUEST TLLI=0x%08x type=%s %s\n", msgb_tlli(msg), get_value_string(gprs_det_t_mo_strs, detach_type), power_off ? "Power-off" : ""); /* Only send the Detach Accept (MO) if power off isn't indicated, * see 04.08, 4.7.4.1.2/3 for details */ if (!power_off) { /* force_stby = 0 */ if (ctx) rc = gsm48_tx_gmm_det_ack(ctx, 0); else rc = gsm48_tx_gmm_det_ack_oldmsg(msg, 0); } if (ctx) { struct sgsn_signal_data sig_data; memset(&sig_data, 0, sizeof(sig_data)); sig_data.mm = ctx; osmo_signal_dispatch(SS_SGSN, S_SGSN_DETACH, &sig_data); mm_ctx_cleanup_free(ctx, "GMM DETACH REQUEST"); } return rc; } /* Chapter 9.4.15: Routing area update accept */ static int gsm48_tx_gmm_ra_upd_ack(struct sgsn_mm_ctx *mm) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 UPD ACK"); struct gsm48_hdr *gh; struct gsm48_ra_upd_ack *rua; unsigned long t; #ifdef PTMSI_ALLOC uint8_t *l; int rc; struct osmo_mobile_identity mi; #endif rate_ctr_inc(rate_ctr_group_get_ctr(sgsn->rate_ctrs, CTR_GPRS_ROUTING_AREA_ACKED)); LOGMMCTXP(LOGL_INFO, mm, "<- GMM ROUTING AREA UPDATE ACCEPT\n"); mmctx2msgid(msg, mm); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_RA_UPD_ACK; rua = (struct gsm48_ra_upd_ack *) msgb_put(msg, sizeof(*rua)); rua->force_stby = 0; /* not indicated */ rua->upd_result = 0; /* RA updated */ /* Periodic RA update timer */ t = osmo_tdef_get(sgsn->cfg.T_defs, 3312, OSMO_TDEF_S, -1); rua->ra_upd_timer = gprs_secs_to_tmr_floor(t); osmo_routing_area_id_encode_buf((uint8_t *)&rua->ra_id, sizeof(struct gsm48_ra_id), &mm->ra); #if 0 /* Optional: P-TMSI signature */ msgb_v_put(msg, GSM48_IE_GMM_PTMSI_SIG); ptsig = msgb_put(msg, 3); ptsig[0] = mm->p_tmsi_sig >> 16; ptsig[1] = mm->p_tmsi_sig >> 8; ptsig[2] = mm->p_tmsi_sig & 0xff; #endif #ifdef PTMSI_ALLOC /* Optional: Allocated P-TMSI */ mi = (struct osmo_mobile_identity){ .type = GSM_MI_TYPE_TMSI, .tmsi = mm->p_tmsi, }; l = msgb_tl_put(msg, GSM48_IE_GMM_ALLOC_PTMSI); rc = osmo_mobile_identity_encode_msgb(msg, &mi, false); if (rc < 0) { msgb_free(msg); return -EINVAL; } *l = rc; #endif /* MS identity */ /* List of Received N-PDU */ /* Optional: Negotiated READY timer value */ t = osmo_tdef_get(sgsn->cfg.T_defs, 3314, OSMO_TDEF_S, -1); msgb_tv_put(msg, GSM48_IE_GMM_TIMER_READY, gprs_secs_to_tmr_floor(t)); /* GMM cause */ /* PDP Context Status */ uint16_t pdp_ctx_status = encode_ms_ctx_status(mm); msgb_tlv_put(msg, GSM48_IE_GMM_PDP_CTX_STATUS, 2, (uint8_t *) &pdp_ctx_status); /* MS ID, ... */ return gsm48_gmm_sendmsg(msg, 0, mm, true); } /* Chapter 9.4.17: Routing area update reject */ int gsm48_tx_gmm_ra_upd_rej(struct msgb *old_msg, uint8_t cause) { struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 RA UPD REJ"); struct gsm48_hdr *gh; LOGP(DMM, LOGL_NOTICE, "<- ROUTING AREA UPDATE REJECT\n"); rate_ctr_inc(rate_ctr_group_get_ctr(sgsn->rate_ctrs, CTR_GPRS_ROUTING_AREA_REJECT)); gmm_copy_id(msg, old_msg); gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 2); gh->proto_discr = GSM48_PDISC_MM_GPRS; gh->msg_type = GSM48_MT_GMM_RA_UPD_REJ; gh->data[0] = cause; gh->data[1] = 0; /* ? */ /* Option: P-TMSI signature, allocated P-TMSI, MS ID, ... */ return gsm48_gmm_sendmsg(msg, 0, NULL, false); } /* Chapter 9.4.14: Routing area update request */ static int gsm48_rx_gmm_ra_upd_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg, struct gprs_llc_llme *llme) { #ifndef PTMSI_ALLOC struct sgsn_signal_data sig_data; #endif enum gsm48_gmm_cause reject_cause = GMM_CAUSE_PROTO_ERR_UNSPEC; struct gprs_gmm_ra_upd_req req; int rc; rc = gprs_gmm_parse_ra_upd_req(msg, &req); if (rc) { reject_cause = rc; goto rejected; } /* TODO: In iu mode - handle follow-on request. * The follow-on request can be signaled in an Attach Request on IuPS. * This means the MS/UE asks to keep the PS connection open for further requests * after the Attach Request succeed. * The SGSN can decide if it close the connection or not. Both are spec conform. */ rate_ctr_inc(rate_ctr_group_get_ctr(sgsn->rate_ctrs, CTR_GPRS_ROUTING_AREA_REQUEST)); LOGMMCTXP(LOGL_INFO, mmctx, "-> GMM RA UPDATE REQUEST type=\"%s\"\n", get_value_string(gprs_upd_t_strs, req.update_type)); switch (req.update_type) { case GPRS_UPD_T_RA_LA: case GPRS_UPD_T_RA_LA_IMSI_ATT: LOGMMCTXP(LOGL_NOTICE, mmctx, "Update type %d unsupported in Mode III, is your SI13 corrupt?\n", req.update_type); reject_cause = GMM_CAUSE_PROTO_ERR_UNSPEC; goto rejected; case GPRS_UPD_T_RA: case GPRS_UPD_T_PERIODIC: break; } if (!mmctx) { /* BSSGP doesn't give us an mmctx */ /* TODO: Check if there is an MM CTX with old_ra_id and * the P-TMSI (if given, reguired for UMTS) or as last resort * if the TLLI matches foreign_tlli (P-TMSI). Note that this * is an optimization to avoid the RA reject (impl detached) * below, which will cause a new attach cycle. */ /* Look-up the MM context based on old RA-ID and TLLI */ if (!MSG_IU_UE_CTX(msg)) { /* Gb */ mmctx = sgsn_mm_ctx_by_tlli_and_ptmsi(msgb_tlli(msg), &req.old_rai); } else if (TLVP_PRESENT(&req.tlv, GSM48_IE_GMM_ALLOC_PTMSI)) { #ifdef BUILD_IU /* In Iu mode search only for ptmsi */ struct osmo_mobile_identity mi; if (osmo_mobile_identity_decode(&mi, TLVP_VAL(&req.tlv, GSM48_IE_GMM_ALLOC_PTMSI), TLVP_LEN(&req.tlv, GSM48_IE_GMM_ALLOC_PTMSI), false) || mi.type != GSM_MI_TYPE_TMSI) { LOGIUP(MSG_IU_UE_CTX(msg), LOGL_ERROR, "Cannot decode P-TMSI\n"); goto rejected; } mmctx = sgsn_mm_ctx_by_ptmsi(mi.tmsi); #else LOGIUP(MSG_IU_UE_CTX(msg), LOGL_ERROR, "Rejecting GMM RA Update Request: No Iu support\n"); goto rejected; #endif } if (mmctx) { LOGMMCTXP(LOGL_INFO, mmctx, "Looked up by matching TLLI and P_TMSI. " "BSSGP TLLI: %08x, P-TMSI: %08x (%08x), " "TLLI: %08x (%08x), RA: %s\n", msgb_tlli(msg), mmctx->p_tmsi, mmctx->p_tmsi_old, mmctx->gb.tlli, mmctx->gb.tlli_new, osmo_rai_name2(&mmctx->ra)); /* A RAT change will trigger the common procedure * below after handling the RAT change. Protect it * here from being called twice */ if (!mmctx_did_rat_change(mmctx, msg)) osmo_fsm_inst_dispatch(mmctx->gmm_fsm, E_GMM_COMMON_PROC_INIT_REQ, NULL); } } else if (osmo_rai_cmp(&mmctx->ra, &req.old_rai) || mmctx->gmm_fsm->state == ST_GMM_DEREGISTERED) { /* We've received either a RAU for a MS which isn't registered * or a RAU with an unknown RA ID. As long the SGSN doesn't support * PS handover we treat this as invalid RAU */ struct osmo_routing_area_id new_ra_id = {}; char new_ra[32]; bssgp_parse_cell_id2(&new_ra_id, NULL, msgb_bcid(msg), 8); osmo_rai_name2_buf(new_ra, sizeof(new_ra), &new_ra_id); if (mmctx->gmm_fsm->state == ST_GMM_DEREGISTERED) LOGMMCTXP(LOGL_INFO, mmctx, "Rejecting RAU - GMM state is deregistered. Old RA: %s New RA: %s\n", osmo_rai_name2(&req.old_rai), new_ra); else LOGMMCTXP(LOGL_INFO, mmctx, "Rejecting RAU - Old RA doesn't match MM. Old RA: %s New RA: %s\n", osmo_rai_name2(&req.old_rai), new_ra); reject_cause = GMM_CAUSE_IMPL_DETACHED; goto rejected; } if (!mmctx) { if (llme) { /* send a XID reset to re-set all LLC sequence numbers * in the MS */ LOGGBP(llme, DMM, LOGL_NOTICE, "LLC XID RESET\n"); gprs_llgmm_reset_oldmsg(msg, GPRS_SAPI_GMM, llme); /* The RAU didn't come from expected TLLI+RAI, so it's for sure bad and should be rejected. * In any case, before unassigning (freeing) the LLME during the REJECT below, make sure * beforehand that if there's an mmctx relating to that llme it is also freed. * Otherwise it would be kept pointining at a dangling freed llme object. */ mmctx = sgsn_mm_ctx_by_llme(llme); if (mmctx) { char old_ra_id_name[32]; osmo_rai_name2_buf(old_ra_id_name, sizeof(old_ra_id_name), &req.old_rai); LOGMMCTXP(LOGL_NOTICE, mmctx, "Rx RA Update Request with unexpected TLLI=%08x Old RA=%s (expected Old RA: %s)!\n", msgb_tlli(msg), old_ra_id_name, osmo_rai_name2(&mmctx->ra)); /* mmctx will be released (and its llme un assigned) after REJECT below. */ } } /* The MS has to perform GPRS attach */ /* Device is still IMSI attached for CS but initiate GPRS ATTACH, * see GSM 04.08, 4.7.5.1.4 and G.6 */ LOGGBIUP(llme, msg, LOGL_ERROR, "Rejecting GMM RA Update Request: MS should GMM Attach first\n"); reject_cause = GMM_CAUSE_IMPL_DETACHED; goto rejected; } if (mmctx_did_rat_change(mmctx, msg)) { mmctx_handle_rat_change(mmctx, msg, llme); osmo_fsm_inst_dispatch(mmctx->gmm_fsm, E_GMM_COMMON_PROC_INIT_REQ, NULL); } /* Store new BVCI/NSEI in MM context (FIXME: delay until we ack?) */ msgid2mmctx(mmctx, msg); /* Bump the statistics of received signalling msgs for this MM context */ rate_ctr_inc(rate_ctr_group_get_ctr(mmctx->ctrg, GMM_CTR_PKTS_SIG_IN)); /* Update the MM context with the new RA-ID */ if (mmctx->ran_type == MM_CTX_T_GERAN_Gb && msgb_bcid(msg)) { bssgp_parse_cell_id2(&mmctx->ra, NULL, msgb_bcid(msg), 8); /* Update the MM context with the new (i.e. foreign) TLLI */ mmctx->gb.tlli = msgb_tlli(msg); } /* Update the MM context with the new DRX params */ if (TLVP_PRESENT(&req.tlv, GSM48_IE_GMM_DRX_PARAM)) memcpy(&mmctx->drx_parms, TLVP_VAL(&req.tlv, GSM48_IE_GMM_DRX_PARAM), sizeof(mmctx->drx_parms)); /* FIXME: Update the MM context with the MS radio acc capabilities */ /* FIXME: Update the MM context with the MS network capabilities */ rate_ctr_inc(rate_ctr_group_get_ctr(mmctx->ctrg, GMM_CTR_RA_UPDATE)); #ifdef PTMSI_ALLOC ptmsi_update(mmctx); /* Start T3350 and re-transmit up to 5 times until ATTACH COMPLETE */ mmctx->t3350_mode = GMM_T3350_MODE_RAU; mmctx_timer_start(mmctx, 3350); #else /* Make sure we are NORMAL (i.e. not SUSPENDED anymore) */ osmo_fsm_inst_dispatch(mmctx->gmm_fsm, E_GMM_ATTACH_SUCCESS, NULL); memset(&sig_data, 0, sizeof(sig_data)); sig_data.mm = mmctx; osmo_signal_dispatch(SS_SGSN, S_SGSN_UPDATE, &sig_data); #endif if (mmctx->ran_type == MM_CTX_T_GERAN_Gb) { /* Even if there is no P-TMSI allocated, the MS will switch from * foreign TLLI to local TLLI */ mmctx->gb.tlli_new = gprs_tmsi2tlli(mmctx->p_tmsi, TLLI_LOCAL); /* Inform LLC layer about new TLLI but keep accepting the old one during Rx */ gprs_llgmm_assign(mmctx->gb.llme, mmctx->gb.tlli, mmctx->gb.tlli_new); } /* Look at PDP Context Status IE and see if MS's view of * activated/deactivated NSAPIs agrees with our view */ if (TLVP_PRESENT(&req.tlv, GSM48_IE_GMM_PDP_CTX_STATUS)) { uint16_t pdp_status = osmo_load16le(TLVP_VAL(&req.tlv, GSM48_IE_GMM_PDP_CTX_STATUS)); process_ms_ctx_status(mmctx, pdp_status); } /* Send RA UPDATE ACCEPT. In Iu, the RA upd request can be called from * a new Iu connection, so we might need to re-authenticate the * connection as well as turn on integrity protection. */ mmctx->pending_req = GSM48_MT_GMM_RA_UPD_REQ; return gsm48_gmm_authorize(mmctx); rejected: /* Send RA UPDATE REJECT */ LOGMMCTXP(LOGL_NOTICE, mmctx, "Rejecting RA Update Request with cause '%s' (%d)\n", get_value_string(gsm48_gmm_cause_names, reject_cause), reject_cause); rc = gsm48_tx_gmm_ra_upd_rej(msg, reject_cause); if (mmctx) mm_ctx_cleanup_free(mmctx, "GMM RA UPDATE REJ"); else if (llme) gprs_llgmm_unassign(llme); #ifdef BUILD_IU else if (MSG_IU_UE_CTX(msg)) { unsigned long X1001 = osmo_tdef_get(sgsn->cfg.T_defs, -1001, OSMO_TDEF_S, -1); sgsn_ranap_iu_tx_release_free(MSG_IU_UE_CTX(msg), NULL, (int) X1001); } #endif return rc; } /* 3GPP TS 24.008 § 9.4.16: Routing area update complete */ static int gsm48_rx_gmm_ra_upd_compl(struct sgsn_mm_ctx *mmctx) { struct sgsn_signal_data sig_data; /* only in case SGSN offered new P-TMSI */ LOGMMCTXP(LOGL_INFO, mmctx, "-> ROUTING AREA UPDATE COMPLETE\n"); mmctx_timer_stop(mmctx, 3350); mmctx->t3350_mode = GMM_T3350_MODE_NONE; mmctx->p_tmsi_old = 0; mmctx->pending_req = 0; osmo_fsm_inst_dispatch(mmctx->gmm_fsm, E_GMM_COMMON_PROC_SUCCESS, NULL); switch(mmctx->ran_type) { case MM_CTX_T_UTRAN_Iu: osmo_fsm_inst_dispatch(mmctx->iu.mm_state_fsm, E_PMM_RA_UPDATE, NULL); break; case MM_CTX_T_GERAN_Gb: /* Unassign the old TLLI */ mmctx->gb.tlli = mmctx->gb.tlli_new; gprs_llgmm_assign(mmctx->gb.llme, TLLI_UNASSIGNED, mmctx->gb.tlli_new); osmo_fsm_inst_dispatch(mmctx->gb.mm_state_fsm, E_MM_RA_UPDATE, NULL); break; } memset(&sig_data, 0, sizeof(sig_data)); sig_data.mm = mmctx; osmo_signal_dispatch(SS_SGSN, S_SGSN_UPDATE, &sig_data); return 0; } /* 3GPP TS 24.008 § 9.4.8: P-TMSI reallocation complete */ static int gsm48_rx_gmm_ptmsi_reall_compl(struct sgsn_mm_ctx *mmctx) { LOGMMCTXP(LOGL_INFO, mmctx, "-> PTMSI REALLOCATION COMPLETE\n"); mmctx_timer_stop(mmctx, 3350); mmctx->t3350_mode = GMM_T3350_MODE_NONE; mmctx->p_tmsi_old = 0; mmctx->pending_req = 0; if (mmctx->ran_type == MM_CTX_T_GERAN_Gb) { /* Unassign the old TLLI */ mmctx->gb.tlli = mmctx->gb.tlli_new; //gprs_llgmm_assign(mmctx->gb.llme, TLLI_UNASSIGNED, mmctx->gb.tlli_new, GPRS_ALGO_GEA0, NULL); } return 0; } /* 3GPP TS 24.008 § 9.4.20 Service request. * In Iu, a UE in PMM-IDLE mode can use GSM48_MT_GMM_SERVICE_REQ to switch back * to PMM-CONNECTED mode. */ static int gsm48_rx_gmm_service_req(struct sgsn_mm_ctx *ctx, struct msgb *msg) { struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); uint8_t *cur = gh->data, *mi_data; uint8_t service_type, mi_len; struct tlv_parsed tp; struct osmo_mobile_identity mi; char mi_log_string[32]; enum gsm48_gmm_cause reject_cause; int rc; LOGMMCTXP(LOGL_INFO, ctx, "-> GMM SERVICE REQUEST "); /* This message is only valid in Iu mode */ if (!MSG_IU_UE_CTX(msg)) { LOGPC(DMM, LOGL_INFO, "Invalid if not in Iu mode\n"); return -1; } /* Skip Ciphering key sequence number 10.5.1.2 */ /* uint8_t ciph_seq_nr = *cur & 0x07; */ /* Service type 10.5.5.20 */ service_type = (*cur++ >> 4) & 0x07; /* Mobile Identity (P-TMSI or IMSI) 10.5.1.4 */ mi_len = *cur++; mi_data = cur; cur += mi_len; rc = osmo_mobile_identity_decode(&mi, mi_data, mi_len, false); if (rc) goto err_inval; osmo_mobile_identity_to_str_buf(mi_log_string, sizeof(mi_log_string), &mi); DEBUGPC(DMM, "MI(%s) type=\"%s\" ", mi_log_string, get_value_string(gprs_service_t_strs, service_type)); LOGPC(DMM, LOGL_INFO, "\n"); /* Optional: PDP context status, MBMS context status, Uplink data status, Device properties */ tlv_parse(&tp, &gsm48_gmm_ie_tlvdef, cur, (msg->data + msg->len) - cur, 0, 0); switch (mi.type) { case GSM_MI_TYPE_IMSI: /* Try to find MM context based on IMSI */ if (!ctx) ctx = sgsn_mm_ctx_by_imsi(mi.imsi); if (!ctx) { /* FIXME: We need to have a context for service request? */ reject_cause = GMM_CAUSE_IMPL_DETACHED; goto rejected; } msgid2mmctx(ctx, msg); break; case GSM_MI_TYPE_TMSI: /* Try to find MM context based on P-TMSI */ if (!ctx) ctx = sgsn_mm_ctx_by_ptmsi(mi.tmsi); if (!ctx) { /* FIXME: We need to have a context for service request? */ reject_cause = GMM_CAUSE_IMPL_DETACHED; goto rejected; } msgid2mmctx(ctx, msg); break; default: LOGMMCTXP(LOGL_NOTICE, ctx, "Rejecting SERVICE REQUEST with " "MI %s\n", mi_log_string); reject_cause = GMM_CAUSE_MS_ID_NOT_DERIVED; goto rejected; } osmo_fsm_inst_dispatch(ctx->gmm_fsm, E_GMM_COMMON_PROC_INIT_REQ, NULL); ctx->iu.service.type = service_type; /* Look at PDP Context Status IE and see if MS's view of * activated/deactivated NSAPIs agrees with our view */ if (TLVP_PRESENT(&tp, GSM48_IE_GMM_PDP_CTX_STATUS)) { /* TODO: Use tlvp_val16le when available */ uint16_t pdp_status = osmo_load16le(TLVP_VAL(&tp, GSM48_IE_GMM_PDP_CTX_STATUS)); process_ms_ctx_status(ctx, pdp_status); /* 3GPP TS 24.008 § 4.7.13.4 Service request procedure not * accepted by the network. Cause #40. If MS has PDP Contexts in * Active state in pdp_status but there is no PDP contexts on * SGSN side then Reject with the cause will force the mobile to * reset PDP contexts */ if (llist_empty(&ctx->pdp_list) && pdp_status_has_active_nsapis(pdp_status)) { reject_cause = GMM_CAUSE_NO_PDP_ACTIVATED; goto rejected; } } ctx->pending_req = GSM48_MT_GMM_SERVICE_REQ; return gsm48_gmm_authorize(ctx); err_inval: LOGPC(DMM, LOGL_INFO, "\n"); reject_cause = GMM_CAUSE_SEM_INCORR_MSG; rejected: /* Send SERVICE REJECT */ LOGMMCTXP(LOGL_NOTICE, ctx, "Rejecting Service Request with cause '%s' (%d)\n", get_value_string(gsm48_gmm_cause_names, reject_cause), reject_cause); rc = gsm48_tx_gmm_service_rej_oldmsg(msg, reject_cause); return rc; } static int gsm48_rx_gmm_status(struct sgsn_mm_ctx *mmctx, struct msgb *msg) { struct gsm48_hdr *gh = msgb_l3(msg); LOGMMCTXP(LOGL_INFO, mmctx, "-> GMM STATUS (cause: %s)\n", get_value_string(gsm48_gmm_cause_names, gh->data[0])); return 0; } /* Rx GPRS Mobility Management. MMCTX can be NULL when called. On !Gb (Iu), llme is NULL */ int gsm0408_rcv_gmm(struct sgsn_mm_ctx *mmctx, struct msgb *msg, struct gprs_llc_llme *llme, bool drop_cipherable) { struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); int rc; if (drop_cipherable && gsm48_hdr_gmm_cipherable(gh)) { LOGMMCTXP(LOGL_NOTICE, mmctx, "Dropping cleartext GMM %s which " "is expected to be encrypted for TLLI 0x%08x\n", get_value_string(gprs_msgt_gmm_names, gh->msg_type), llme->tlli); return -EBADMSG; } if (llme && !mmctx && gh->msg_type != GSM48_MT_GMM_ATTACH_REQ && gh->msg_type != GSM48_MT_GMM_RA_UPD_REQ) { LOGGBP(llme, DMM, LOGL_NOTICE, "Cannot handle GMM for unknown MM CTX\n"); /* 4.7.10 */ if (gh->msg_type == GSM48_MT_GMM_STATUS) { /* TLLI unassignment */ gprs_llgmm_unassign(llme); return 0; } /* Don't reply or establish a LLME on DETACH_ACK */ if (gh->msg_type == GSM48_MT_GMM_DETACH_ACK) return gprs_llgmm_unassign(llme); /* Don't reply to deatch requests, reason power off */ if (gh->msg_type == GSM48_MT_GMM_DETACH_REQ && gh->data[0] & 0x8) { return 0; } gprs_llgmm_reset(llme); /* Don't force it into re-attachment */ if (gh->msg_type == GSM48_MT_GMM_DETACH_REQ) { /* Handle Detach Request */ rc = gsm48_rx_gmm_det_req(NULL, msg); /* TLLI unassignment */ gprs_llgmm_unassign(llme); return rc; } /* Force the MS to re-attach */ rc = gsm0408_gprs_force_reattach_oldmsg(msg, llme); /* TLLI unassignment */ gprs_llgmm_unassign(llme); return rc; } /* A RAT change is only expected/allowed for RAU/Attach Req */ if (mmctx && mmctx_did_rat_change(mmctx, msg)) { switch (gh->msg_type) { case GSM48_MT_GMM_RA_UPD_REQ: case GSM48_MT_GMM_ATTACH_REQ: break; default: /* This shouldn't happen with other message types and * we need to error out to prevent a crash */ LOGMMCTXP(LOGL_NOTICE, mmctx, "Dropping GMM %s which was received on different " "RAT (mmctx ran_type=%u, msg_iu_ue_ctx=%p\n", get_value_string(gprs_msgt_gmm_names, gh->msg_type), mmctx->ran_type, MSG_IU_UE_CTX(msg)); return -EINVAL; } } /* * For a few messages, mmctx may be NULL. For most, we want to ensure a * non-NULL mmctx. At the same time, we want to keep the message * validity check intact, so that all message types appear in the * switch statement and the default case thus means "unknown message". * If we split the switch in two parts to check non-NULL halfway, the * unknown-message check breaks, or we'd need to duplicate the switch * cases in both parts. Just keep one large switch and add some gotos. */ switch (gh->msg_type) { case GSM48_MT_GMM_RA_UPD_REQ: rc = gsm48_rx_gmm_ra_upd_req(mmctx, msg, llme); break; case GSM48_MT_GMM_ATTACH_REQ: rc = gsm48_rx_gmm_att_req(mmctx, msg, llme); break; case GSM48_MT_GMM_SERVICE_REQ: rc = gsm48_rx_gmm_service_req(mmctx, msg); break; /* For all the following types mmctx can not be NULL */ case GSM48_MT_GMM_ID_RESP: if (!mmctx) goto null_mmctx; rc = gsm48_rx_gmm_id_resp(mmctx, msg); break; case GSM48_MT_GMM_STATUS: if (!mmctx) goto null_mmctx; rc = gsm48_rx_gmm_status(mmctx, msg); break; case GSM48_MT_GMM_DETACH_REQ: if (!mmctx) goto null_mmctx; rc = gsm48_rx_gmm_det_req(mmctx, msg); break; case GSM48_MT_GMM_DETACH_ACK: if (!mmctx) goto null_mmctx; LOGMMCTXP(LOGL_INFO, mmctx, "-> DETACH ACK\n"); mm_ctx_cleanup_free(mmctx, "GMM DETACH ACK"); rc = 0; break; case GSM48_MT_GMM_ATTACH_COMPL: if (!mmctx) goto null_mmctx; rc = gsm48_rx_gmm_att_compl(mmctx); break; case GSM48_MT_GMM_RA_UPD_COMPL: if (!mmctx) goto null_mmctx; rc = gsm48_rx_gmm_ra_upd_compl(mmctx); break; case GSM48_MT_GMM_PTMSI_REALL_COMPL: if (!mmctx) goto null_mmctx; rc = gsm48_rx_gmm_ptmsi_reall_compl(mmctx); break; case GSM48_MT_GMM_AUTH_CIPH_RESP: if (!mmctx) goto null_mmctx; rc = gsm48_rx_gmm_auth_ciph_resp(mmctx, msg); break; case GSM48_MT_GMM_AUTH_CIPH_FAIL: rc = gsm48_rx_gmm_auth_ciph_fail(mmctx, msg); break; default: LOGMMCTXP(LOGL_NOTICE, mmctx, "Unknown GSM 04.08 GMM msg type 0x%02x\n", gh->msg_type); if (mmctx) rc = gsm48_tx_gmm_status(mmctx, GMM_CAUSE_MSGT_NOTEXIST_NOTIMPL); else rc = -EINVAL; break; } return rc; null_mmctx: LOGGBIUP(llme, msg, LOGL_ERROR, "Received GSM 04.08 message type %s," " but no MM context available\n", get_value_string(gprs_msgt_gmm_names, gh->msg_type)); return -EINVAL; } static void mmctx_timer_cb(void *_mm) { struct sgsn_mm_ctx *mm = _mm; struct gsm_auth_tuple *at; int rc; unsigned long seconds; mm->num_T_exp++; switch (mm->T) { case 3350: /* waiting for ATTACH COMPLETE */ if (mm->num_T_exp >= 5) { LOGMMCTXP(LOGL_NOTICE, mm, "T3350 expired >= 5 times\n"); mm_ctx_cleanup_free(mm, "T3350"); /* FIXME: should we return some error? */ break; } /* re-transmit the respective msg and re-start timer */ switch (mm->t3350_mode) { case GMM_T3350_MODE_ATT: gsm48_tx_gmm_att_ack(mm); break; case GMM_T3350_MODE_RAU: gsm48_tx_gmm_ra_upd_ack(mm); break; case GMM_T3350_MODE_PTMSI_REALL: /* FIXME */ break; case GMM_T3350_MODE_NONE: LOGMMCTXP(LOGL_NOTICE, mm, "T3350 mode wasn't set, ignoring timeout\n"); break; } seconds = osmo_tdef_get(sgsn->cfg.T_defs, 3350, OSMO_TDEF_S, -1); osmo_timer_schedule(&mm->timer, seconds, 0); break; case 3360: /* waiting for AUTH AND CIPH RESP */ if (mm->num_T_exp >= 5) { LOGMMCTXP(LOGL_NOTICE, mm, "T3360 expired >= 5 times\n"); mm_ctx_cleanup_free(mm, "T3360"); break; } /* Re-transmit the respective msg and re-start timer */ if (mm->auth_triplet.key_seq == GSM_KEY_SEQ_INVAL) { LOGMMCTXP(LOGL_ERROR, mm, "timeout: invalid auth triplet reference\n"); mm_ctx_cleanup_free(mm, "T3360"); break; } at = &mm->auth_triplet; rc = gsm48_tx_gmm_auth_ciph_req(mm, &at->vec, at->key_seq, false); if (rc < 0) { LOGMMCTXP(LOGL_ERROR, mm, "failed sending Auth. & Ciph. Request: %s \n", strerror(-rc)); } else { seconds = osmo_tdef_get(sgsn->cfg.T_defs, 3360, OSMO_TDEF_S, -1); osmo_timer_schedule(&mm->timer, seconds, 0); } break; case 3370: /* waiting for IDENTITY RESPONSE */ if (mm->num_T_exp >= 5) { LOGMMCTXP(LOGL_NOTICE, mm, "T3370 expired >= 5 times\n"); gsm48_tx_gmm_att_rej(mm, GMM_CAUSE_MS_ID_NOT_DERIVED); mm_ctx_cleanup_free(mm, "GMM ATTACH REJECT (T3370)"); break; } /* re-tranmit IDENTITY REQUEST and re-start timer */ gsm48_tx_gmm_id_req(mm, mm->t3370_id_type); seconds = osmo_tdef_get(sgsn->cfg.T_defs, 3370, OSMO_TDEF_S, -1); osmo_timer_schedule(&mm->timer, seconds, 0); break; default: LOGMMCTXP(LOGL_ERROR, mm, "timer expired in unknown mode %u\n", mm->T); } } int gsm0408_gprs_force_reattach_oldmsg(struct msgb *msg, struct gprs_llc_llme *llme) { int rc; if (llme) gprs_llgmm_reset_oldmsg(msg, GPRS_SAPI_GMM, llme); rc = gsm48_tx_gmm_detach_req_oldmsg( msg, GPRS_DET_T_MT_REATT_REQ, GMM_CAUSE_IMPL_DETACHED); return rc; } int gsm0408_gprs_force_reattach(struct sgsn_mm_ctx *mmctx) { int rc; if (mmctx->ran_type == MM_CTX_T_GERAN_Gb) gprs_llgmm_reset(mmctx->gb.llme); rc = gsm48_tx_gmm_detach_req( mmctx, GPRS_DET_T_MT_REATT_REQ, GMM_CAUSE_IMPL_DETACHED); mm_ctx_cleanup_free(mmctx, "forced reattach"); return rc; } int gprs_gmm_rx_suspend(struct osmo_routing_area_id *raid, uint32_t tlli) { struct sgsn_mm_ctx *mmctx; mmctx = sgsn_mm_ctx_by_tlli(tlli, raid); if (!mmctx) { LOGP(DMM, LOGL_NOTICE, "SUSPEND request for unknown " "TLLI=%08x\n", tlli); return -EINVAL; } if (!gmm_fsm_is_registered(mmctx->gmm_fsm)) { LOGMMCTXP(LOGL_NOTICE, mmctx, "SUSPEND request while state " "!= REGISTERED (TLLI=%08x)\n", tlli); return -EINVAL; } /* Transition from REGISTERED_NORMAL to REGISTERED_SUSPENDED */ osmo_fsm_inst_dispatch(mmctx->gmm_fsm, E_GMM_SUSPEND, NULL); return 0; } int gprs_gmm_rx_resume(struct osmo_routing_area_id *raid, uint32_t tlli, uint8_t suspend_ref) { struct sgsn_mm_ctx *mmctx; /* FIXME: make use of suspend reference? */ mmctx = sgsn_mm_ctx_by_tlli(tlli, raid); if (!mmctx) { LOGP(DMM, LOGL_NOTICE, "RESUME request for unknown " "TLLI=%08x\n", tlli); return -EINVAL; } if (!gmm_fsm_is_registered(mmctx->gmm_fsm)) { LOGMMCTXP(LOGL_NOTICE, mmctx, "RESUME request while state " "!= SUSPENDED (TLLI=%08x)\n", tlli); /* FIXME: should we not simply ignore it? */ return -EINVAL; } /* Transition from SUSPENDED to NORMAL */ osmo_fsm_inst_dispatch(mmctx->gmm_fsm, E_GMM_RESUME, NULL); return 0; } /* Has to be called whenever any PDU (signaling, data, ...) has been received */ void gprs_gb_recv_pdu(struct sgsn_mm_ctx *mmctx, const struct msgb *msg) { msgid2mmctx(mmctx, msg); if (mmctx->gb.llme) osmo_fsm_inst_dispatch(mmctx->gb.mm_state_fsm, E_MM_PDU_RECEPTION, NULL); } /* Main entry point for incoming 04.08 GPRS messages from Gb */ int gsm0408_gprs_rcvmsg_gb(struct msgb *msg, struct gprs_llc_llme *llme, bool drop_cipherable) { struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); uint8_t pdisc = gsm48_hdr_pdisc(gh); struct sgsn_mm_ctx *mmctx; struct osmo_routing_area_id ra_id = {}; int rc = -EINVAL; bssgp_parse_cell_id2(&ra_id, NULL, msgb_bcid(msg), 8); mmctx = sgsn_mm_ctx_by_tlli(msgb_tlli(msg), &ra_id); if (mmctx) { rate_ctr_inc(rate_ctr_group_get_ctr(mmctx->ctrg, GMM_CTR_PKTS_SIG_IN)); mmctx->gb.llme = llme; gprs_gb_recv_pdu(mmctx, msg); } /* MMCTX can be NULL */ switch (pdisc) { case GSM48_PDISC_MM_GPRS: rc = gsm0408_rcv_gmm(mmctx, msg, llme, drop_cipherable); break; case GSM48_PDISC_SM_GPRS: rc = gsm0408_rcv_gsm(mmctx, msg, llme); break; default: LOGMMCTXP(LOGL_NOTICE, mmctx, "Unknown GSM 04.08 discriminator 0x%02x: %s\n", pdisc, osmo_hexdump((uint8_t *)gh, msgb_l3len(msg))); /* FIXME: return status message */ break; } /* MMCTX can be invalid */ return rc; } #ifdef BUILD_IU /* Main entry point for incoming 04.08 GPRS messages from Iu */ int gsm0408_gprs_rcvmsg_iu(struct msgb *msg, struct gprs_ra_id *ra_id, uint16_t *sai) { struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg); uint8_t pdisc = gsm48_hdr_pdisc(gh); struct sgsn_mm_ctx *mmctx; int rc = -EINVAL; mmctx = sgsn_mm_ctx_by_ue_ctx(MSG_IU_UE_CTX(msg)); if (mmctx) { rate_ctr_inc(rate_ctr_group_get_ctr(mmctx->ctrg, GMM_CTR_PKTS_SIG_IN)); if (ra_id) memcpy(&mmctx->ra, ra_id, sizeof(mmctx->ra)); } /* MMCTX can be NULL */ switch (pdisc) { case GSM48_PDISC_MM_GPRS: rc = gsm0408_rcv_gmm(mmctx, msg, NULL, false); #pragma message "set drop_cipherable arg for gsm0408_rcv_gmm() from IuPS?" break; case GSM48_PDISC_SM_GPRS: rc = gsm0408_rcv_gsm(mmctx, msg, NULL); break; default: LOGMMCTXP(LOGL_NOTICE, mmctx, "Unknown GSM 04.08 discriminator 0x%02x: %s\n", pdisc, osmo_hexdump((uint8_t *)gh, msgb_l3len(msg))); /* FIXME: return status message */ break; } /* MMCTX can be invalid */ return rc; } #endif /* ifdef BUILD_IU */