/* GSM 08.08 BSSMAP handling */ /* (C) 2009-2012 by Holger Hans Peter Freyther * (C) 2009-2012 by On-Waves * (C) 2017 by Harald Welte * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #define IP_V4_ADDR_LEN 4 /* * helpers for the assignment command */ /* We expect MSC to provide use with an Osmocom extension TLV in BSSMAP_RESET to * announce Osmux support */ static void update_msc_osmux_support(struct bsc_msc_data *msc, struct msgb *msg, unsigned int length) { struct tlv_parsed tp; int rc; bool old_value = msc->remote_supports_osmux; rc = tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, length - 1, 0, 0); if (rc < 0) LOGP(DMSC, LOGL_NOTICE, "Failed parsing TLV looking for Osmux support\n"); msc->remote_supports_osmux = !!TLVP_PRESENT(&tp, GSM0808_IE_OSMO_OSMUX_SUPPORT); if (old_value != msc->remote_supports_osmux) LOGP(DMSC, LOGL_INFO, "MSC detected AoIP Osmux support changed: %d->%d\n", old_value, msc->remote_supports_osmux); } static int bssmap_handle_reset_ack(struct bsc_msc_data *msc, struct msgb *msg, unsigned int length) { LOGP(DMSC, LOGL_NOTICE, "RESET ACK from MSC: %s\n", osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance), &msc->a.msc_addr)); /* Inform the FSM that controls the RESET/RESET-ACK procedure * that we have successfully received the reset-ack message */ a_reset_ack_confirm(msc); update_msc_osmux_support(msc, msg, length); return 0; } /* Handle MSC sided reset */ static int bssmap_handle_reset(struct bsc_msc_data *msc, struct msgb *msg, unsigned int length) { LOGP(DMSC, LOGL_NOTICE, "RESET from MSC: %s\n", osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance), &msc->a.msc_addr)); /* Instruct the bsc to close all open sigtran connections and to * close all active channels on the BTS side as well */ osmo_bsc_sigtran_reset(msc); /* Drop all ongoing paging requests that this MSC has created on any BTS */ paging_flush_network(msc->network, msc); update_msc_osmux_support(msc, msg, length); /* Inform the MSC that we have received the reset request and * that we acted accordingly */ osmo_bsc_sigtran_tx_reset_ack(msc); return 0; } /* Page a subscriber based on TMSI and LAC via the specified BTS. * The msc parameter is the MSC which issued the corresponding paging request. * Log an error if paging failed. */ static void page_subscriber(struct bsc_msc_data *msc, struct gsm_bts *bts, uint32_t tmsi, uint32_t lac, const char *mi_string, uint8_t chan_needed) { struct bsc_subscr *subscr; int ret; subscr = bsc_subscr_find_or_create_by_imsi(msc->network->bsc_subscribers, mi_string); if (subscr) log_set_context(LOG_CTX_BSC_SUBSCR, subscr); LOGP(DMSC, LOGL_INFO, "Paging request from MSC BTS: %d IMSI: '%s' TMSI: '0x%x/%u' LAC: 0x%x\n", bts->nr, mi_string, tmsi, tmsi, lac); if (!subscr) { LOGP(DMSC, LOGL_ERROR, "Paging request failed: Could not allocate subscriber for %s\n", mi_string); return; } subscr->lac = lac; subscr->tmsi = tmsi; ret = bsc_grace_paging_request(msc->network->rf_ctrl->policy, subscr, chan_needed, msc, bts); if (ret == 0) LOGP(DMSC, LOGL_INFO, "Paging request failed or repeated paging: BTS: %d IMSI: '%s' TMSI: '0x%x/%u' LAC: 0x%x\n", bts->nr, mi_string, tmsi, tmsi, lac); /* the paging code has grabbed its own references */ bsc_subscr_put(subscr); log_set_context(LOG_CTX_BSC_SUBSCR, NULL); } static void page_all_bts(struct bsc_msc_data *msc, uint32_t tmsi, const char *mi_string, uint8_t chan_needed) { struct gsm_bts *bts; llist_for_each_entry(bts, &msc->network->bts_list, list) page_subscriber(msc, bts, tmsi, GSM_LAC_RESERVED_ALL_BTS, mi_string, chan_needed); } static void page_cgi(struct bsc_msc_data *msc, struct gsm0808_cell_id_list2 *cil, uint32_t tmsi, const char *mi_string, uint8_t chan_needed) { int i; for (i = 0; i < cil->id_list_len; i++) { struct osmo_cell_global_id *id = &cil->id_list[i].global; if (!osmo_plmn_cmp(&id->lai.plmn, &msc->network->plmn)) { int paged = 0; struct gsm_bts *bts; llist_for_each_entry(bts, &msc->network->bts_list, list) { if (bts->location_area_code != id->lai.lac) continue; if (bts->cell_identity != id->cell_identity) continue; page_subscriber(msc, bts, tmsi, id->lai.lac, mi_string, chan_needed); paged = 1; } if (!paged) { LOGP(DMSC, LOGL_NOTICE, "Paging IMSI %s: BTS with LAC %d and CI %d not found\n", mi_string, id->lai.lac, id->cell_identity); } } else { LOGP(DMSC, LOGL_DEBUG, "Paging IMSI %s: MCC-MNC in Cell Identifier List " "(%s) do not match our network (%s)\n", mi_string, osmo_plmn_name(&id->lai.plmn), osmo_plmn_name2(&msc->network->plmn)); } } } static void page_lac_and_ci(struct bsc_msc_data *msc, struct gsm0808_cell_id_list2 *cil, uint32_t tmsi, const char *mi_string, uint8_t chan_needed) { int i; for (i = 0; i < cil->id_list_len; i++) { struct osmo_lac_and_ci_id *id = &cil->id_list[i].lac_and_ci; int paged = 0; struct gsm_bts *bts; llist_for_each_entry(bts, &msc->network->bts_list, list) { if (bts->location_area_code != id->lac) continue; if (bts->cell_identity != id->ci) continue; page_subscriber(msc, bts, tmsi, id->lac, mi_string, chan_needed); paged = 1; } if (!paged) { LOGP(DMSC, LOGL_NOTICE, "Paging IMSI %s: BTS with LAC %d and CI %d not found\n", mi_string, id->lac, id->ci); } } } static void page_ci(struct bsc_msc_data *msc, struct gsm0808_cell_id_list2 *cil, uint32_t tmsi, const char *mi_string, uint8_t chan_needed) { int i; for (i = 0; i < cil->id_list_len; i++) { uint16_t ci = cil->id_list[i].ci; int paged = 0; struct gsm_bts *bts; llist_for_each_entry(bts, &msc->network->bts_list, list) { if (bts->cell_identity != ci) continue; page_subscriber(msc, bts, tmsi, GSM_LAC_RESERVED_ALL_BTS, mi_string, chan_needed); paged = 1; } if (!paged) { LOGP(DMSC, LOGL_NOTICE, "Paging IMSI %s: BTS with CI %d not found\n", mi_string, ci); } } } static void page_lai_and_lac(struct bsc_msc_data *msc, struct gsm0808_cell_id_list2 *cil, uint32_t tmsi, const char *mi_string, uint8_t chan_needed) { int i; for (i = 0; i < cil->id_list_len; i++) { struct osmo_location_area_id *id = &cil->id_list[i].lai_and_lac; if (!osmo_plmn_cmp(&id->plmn, &msc->network->plmn)) { int paged = 0; struct gsm_bts *bts; llist_for_each_entry(bts, &msc->network->bts_list, list) { if (bts->location_area_code != id->lac) continue; page_subscriber(msc, bts, tmsi, id->lac, mi_string, chan_needed); paged = 1; } if (!paged) { LOGP(DMSC, LOGL_NOTICE, "Paging IMSI %s: BTS with LAC %d not found\n", mi_string, id->lac); } } else { LOGP(DMSC, LOGL_DEBUG, "Paging IMSI %s: MCC-MNC in Cell Identifier List " "(%s) do not match our network (%s)\n", mi_string, osmo_plmn_name(&id->plmn), osmo_plmn_name2(&msc->network->plmn)); } } } static void page_lac(struct bsc_msc_data *msc, struct gsm0808_cell_id_list2 *cil, uint32_t tmsi, const char *mi_string, uint8_t chan_needed) { int i; for (i = 0; i < cil->id_list_len; i++) { uint16_t lac = cil->id_list[i].lac; int paged = 0; struct gsm_bts *bts; llist_for_each_entry(bts, &msc->network->bts_list, list) { if (bts->location_area_code != lac) continue; page_subscriber(msc, bts, tmsi, lac, mi_string, chan_needed); paged = 1; } if (!paged) { LOGP(DMSC, LOGL_NOTICE, "Paging IMSI %s: BTS with LAC %d not found\n", mi_string, lac); } } } /* GSM 08.08 § 3.2.1.19 */ static int bssmap_handle_paging(struct bsc_msc_data *msc, struct msgb *msg, unsigned int payload_length) { struct tlv_parsed tp; struct osmo_mobile_identity mi_imsi; uint32_t tmsi = GSM_RESERVED_TMSI; uint8_t data_length; int remain; const uint8_t *data; uint8_t chan_needed = RSL_CHANNEED_ANY; struct gsm0808_cell_id_list2 cil; tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, payload_length - 1, 0, 0); remain = payload_length - 1; if (!TLVP_PRESENT(&tp, GSM0808_IE_IMSI)) { LOGP(DMSC, LOGL_ERROR, "Mandatory IMSI not present.\n"); return -1; } else if ((TLVP_VAL(&tp, GSM0808_IE_IMSI)[0] & GSM_MI_TYPE_MASK) != GSM_MI_TYPE_IMSI) { LOGP(DMSC, LOGL_ERROR, "Wrong content in the IMSI\n"); return -1; } remain -= TLVP_LEN(&tp, GSM0808_IE_IMSI); if (!TLVP_PRESENT(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST)) { LOGP(DMSC, LOGL_ERROR, "Mandatory CELL IDENTIFIER LIST not present.\n"); return -1; } if (TLVP_PRESENT(&tp, GSM0808_IE_TMSI) && TLVP_LEN(&tp, GSM0808_IE_TMSI) == 4) { tmsi = ntohl(tlvp_val32_unal(&tp, GSM0808_IE_TMSI)); remain -= TLVP_LEN(&tp, GSM0808_IE_TMSI); } if (remain <= 0) { LOGP(DMSC, LOGL_ERROR, "Payload too short.\n"); return -1; } /* * parse the IMSI */ if (osmo_mobile_identity_decode(&mi_imsi, TLVP_VAL(&tp, GSM0808_IE_IMSI), TLVP_LEN(&tp, GSM0808_IE_IMSI), false) || mi_imsi.type != GSM_MI_TYPE_IMSI) { LOGP(DMSC, LOGL_ERROR, "Paging: could not parse IMSI\n"); return -1; } /* * There are various cell identifier list types defined at 3GPP TS § 08.08, we don't support all * of them yet. To not disrupt paging operation just because we're lacking some implementation, * interpret any unknown cell identifier type as "page the entire BSS". */ data_length = TLVP_LEN(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST); data = TLVP_VAL(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST); if (gsm0808_dec_cell_id_list2(&cil, data, data_length) < 0) { LOGP(DMSC, LOGL_ERROR, "Paging %s: Could not parse Cell Identifier List\n", osmo_mobile_identity_to_str_c(OTC_SELECT, &mi_imsi)); return -1; } remain = 0; if (TLVP_PRESENT(&tp, GSM0808_IE_CHANNEL_NEEDED) && TLVP_LEN(&tp, GSM0808_IE_CHANNEL_NEEDED) == 1) chan_needed = TLVP_VAL(&tp, GSM0808_IE_CHANNEL_NEEDED)[0] & 0x03; if (TLVP_PRESENT(&tp, GSM0808_IE_EMLPP_PRIORITY)) { LOGP(DMSC, LOGL_ERROR, "eMLPP is not handled\n"); } rate_ctr_inc(&msc->network->bsc_ctrs->ctr[BSC_CTR_PAGING_ATTEMPTED]); switch (cil.id_discr) { case CELL_IDENT_NO_CELL: page_all_bts(msc, tmsi, mi_imsi.imsi, chan_needed); break; case CELL_IDENT_WHOLE_GLOBAL: page_cgi(msc, &cil, tmsi, mi_imsi.imsi, chan_needed); break; case CELL_IDENT_LAC_AND_CI: page_lac_and_ci(msc, &cil, tmsi, mi_imsi.imsi, chan_needed); break; case CELL_IDENT_CI: page_ci(msc, &cil, tmsi, mi_imsi.imsi, chan_needed); break; case CELL_IDENT_LAI_AND_LAC: page_lai_and_lac(msc, &cil, tmsi, mi_imsi.imsi, chan_needed); break; case CELL_IDENT_LAC: page_lac(msc, &cil, tmsi, mi_imsi.imsi, chan_needed); break; case CELL_IDENT_BSS: if (data_length != 1) { LOGP(DMSC, LOGL_ERROR, "Paging %s: Cell Identifier List for BSS (0x%x)" " has invalid length: %u, paging entire BSS anyway (%s)\n", osmo_mobile_identity_to_str_c(OTC_SELECT, &mi_imsi), CELL_IDENT_BSS, data_length, osmo_hexdump(data, data_length)); } page_all_bts(msc, tmsi, mi_imsi.imsi, chan_needed); break; default: LOGP(DMSC, LOGL_NOTICE, "Paging %s: unimplemented Cell Identifier List (0x%x)," " paging entire BSS instead (%s)\n", osmo_mobile_identity_to_str_c(OTC_SELECT, &mi_imsi), cil.id_discr, osmo_hexdump(data, data_length)); page_all_bts(msc, tmsi, mi_imsi.imsi, chan_needed); break; } return 0; } /* select the best cipher permitted by the intersection of both masks */ static int select_best_cipher(uint8_t msc_mask, uint8_t bsc_mask) { uint8_t intersection = msc_mask & bsc_mask; int i; for (i = 7; i >= 0; i--) { if (intersection & (1 << i)) return i; } return -1; } /*! We received a GSM 08.08 CIPHER MODE from the MSC */ static int gsm0808_cipher_mode(struct gsm_subscriber_connection *conn, int cipher, const uint8_t *key, int len, int include_imeisv) { if (cipher > 0 && key == NULL) { LOGP(DRSL, LOGL_ERROR, "%s: Need to have an encryption key.\n", bsc_subscr_name(conn->bsub)); return -1; } if (len > MAX_A5_KEY_LEN) { LOGP(DRSL, LOGL_ERROR, "%s: The key is too long: %d\n", bsc_subscr_name(conn->bsub), len); return -1; } LOGP(DRSL, LOGL_DEBUG, "(subscr %s) Cipher Mode: cipher=%d key=%s include_imeisv=%d\n", bsc_subscr_name(conn->bsub), cipher, osmo_hexdump_nospc(key, len), include_imeisv); conn->lchan->encr.alg_id = RSL_ENC_ALG_A5(cipher); if (key) { conn->lchan->encr.key_len = len; memcpy(conn->lchan->encr.key, key, len); } return gsm48_send_rr_ciph_mode(conn->lchan, include_imeisv); } static int bssmap_handle_clear_cmd(struct gsm_subscriber_connection *conn, struct msgb *msg, unsigned int length) { struct tlv_parsed tp; struct gscon_clear_cmd_data ccd = { .is_csfb = false, }; tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, length - 1, 0, 0); ccd.cause_0808 = gsm0808_get_cause(&tp); if (ccd.cause_0808 < 0) { LOGPFSML(conn->fi, LOGL_ERROR, "Clear Command: Mandatory Cause IE not present.\n"); /* Clear anyway, but without a proper cause. */ ccd.cause_0808 = GSM0808_CAUSE_RADIO_INTERFACE_MESSAGE_FAILURE; } if (TLVP_PRESENT(&tp, GSM0808_IE_CSFB_INDICATION)) ccd.is_csfb = true; osmo_fsm_inst_dispatch(conn->fi, GSCON_EV_A_CLEAR_CMD, &ccd); return 0; } /* * GSM 08.08 § 3.1.14 cipher mode handling. We will have to pick * the cipher to be used for this. In case we are already using * a cipher we will have to send cipher mode reject to the MSC, * otherwise we will have to pick something that we and the MS * is supporting. Currently we are doing it in a rather static * way by picking one encryption or no encryption. */ static int bssmap_handle_cipher_mode(struct gsm_subscriber_connection *conn, struct msgb *msg, unsigned int payload_length) { uint16_t len; const uint8_t *data; struct tlv_parsed tp; struct msgb *resp; int reject_cause = -1; int include_imeisv = 1; const uint8_t *enc_key; uint16_t enc_key_len; uint8_t enc_bits_msc; int chosen_cipher; if (!conn) { LOGP(DMSC, LOGL_ERROR, "No lchan/msc_data in cipher mode command.\n"); return -1; } if (conn->ciphering_handled) { LOGP(DMSC, LOGL_ERROR, "Already seen ciphering command. Protocol Error.\n"); reject_cause = GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC; goto reject; } conn->ciphering_handled = 1; tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, payload_length - 1, 0, 0); if (!TLVP_PRESENT(&tp, GSM0808_IE_ENCRYPTION_INFORMATION)) { LOGP(DMSC, LOGL_ERROR, "IE Encryption Information missing.\n"); reject_cause = GSM0808_CAUSE_INFORMATION_ELEMENT_OR_FIELD_MISSING; goto reject; } /* * check if our global setting is allowed * - Currently we check for A5/0 and A5/1 * - Copy the key if that is necessary * - Otherwise reject */ len = TLVP_LEN(&tp, GSM0808_IE_ENCRYPTION_INFORMATION); if (len < 1) { LOGP(DMSC, LOGL_ERROR, "IE Encryption Information is too short.\n"); reject_cause = GSM0808_CAUSE_INCORRECT_VALUE; goto reject; } data = TLVP_VAL(&tp, GSM0808_IE_ENCRYPTION_INFORMATION); enc_bits_msc = data[0]; enc_key = &data[1]; enc_key_len = len - 1; if (TLVP_PRESENT(&tp, GSM0808_IE_CIPHER_RESPONSE_MODE)) include_imeisv = TLVP_VAL(&tp, GSM0808_IE_CIPHER_RESPONSE_MODE)[0] & 0x1; /* Identical to the GSM0808_IE_ENCRYPTION_INFORMATION above: * a5_encryption == 0 --> 0x01 * a5_encryption == 1 --> 0x02 * a5_encryption == 2 --> 0x04 ... */ enc_bits_msc = data[0]; /* The bit-mask of permitted ciphers from the MSC (sent in ASSIGNMENT COMMAND) is intersected * with the vty-configured mask a the BSC. Finally, the best (highest) possible cipher is * chosen. */ chosen_cipher = select_best_cipher(enc_bits_msc, bsc_gsmnet->a5_encryption_mask); if (chosen_cipher < 0) { LOGP(DMSC, LOGL_ERROR, "Reject: no overlapping A5 ciphers between BSC (0x%02x) " "and MSC (0x%02x)\n", bsc_gsmnet->a5_encryption_mask, enc_bits_msc); reject_cause = GSM0808_CAUSE_CIPHERING_ALGORITHM_NOT_SUPPORTED; goto reject; } /* To complete the confusion, gsm0808_cipher_mode again expects the encryption as a number * from 0 to 7. */ if (gsm0808_cipher_mode(conn, chosen_cipher, enc_key, enc_key_len, include_imeisv)) { reject_cause = GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC; goto reject; } return 0; reject: resp = gsm0808_create_cipher_reject(reject_cause); if (!resp) { LOGP(DMSC, LOGL_ERROR, "Sending the cipher reject failed.\n"); return -1; } rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_TX_DT1_CIPHER_REJECT]); osmo_fsm_inst_dispatch(conn->fi, GSCON_EV_TX_SCCP, resp); return -1; } /* handle LCLS specific IES in BSSMAP ASS REQ */ static void bssmap_handle_ass_req_lcls(struct gsm_subscriber_connection *conn, const struct tlv_parsed *tp) { const uint8_t *config, *control, *gcr; uint8_t gcr_len; /* TS 48.008 sec 3.2.2.115 Global Call Reference */ if (TLVP_PRESENT(tp, GSM0808_IE_GLOBAL_CALL_REF)) { gcr = TLVP_VAL(tp, GSM0808_IE_GLOBAL_CALL_REF); gcr_len = TLVP_LEN(tp, GSM0808_IE_GLOBAL_CALL_REF); if (gcr_len > sizeof(conn->lcls.global_call_ref)) { LOGPFSML(conn->fi, LOGL_ERROR, "Global Call Ref IE of %u bytes is too long: %s\n", gcr_len, osmo_hexdump_nospc(gcr, gcr_len)); } else if (gcr_len < 13) { /* FIXME: document this magic value 13 */ LOGPFSML(conn->fi, LOGL_ERROR, "Global Call Ref IE of %u bytes is too short: %s\n", gcr_len, osmo_hexdump_nospc(gcr, gcr_len)); } else { LOGPFSM(conn->fi, "Setting GCR to %s\n", osmo_hexdump_nospc(gcr, gcr_len)); memcpy(&conn->lcls.global_call_ref, gcr, gcr_len); conn->lcls.global_call_ref_len = gcr_len; } } config = TLVP_VAL_MINLEN(tp, GSM0808_IE_LCLS_CONFIG, 1); control = TLVP_VAL_MINLEN(tp, GSM0808_IE_LCLS_CONN_STATUS_CTRL, 1); if (config || control) { LOGPFSM(conn->fi, "BSSMAP ASS REQ contains LCLS (%s / %s)\n", config ? gsm0808_lcls_config_name(*config) : "NULL", control ? gsm0808_lcls_control_name(*control) : "NULL"); } /* Update the LCLS state with Config + CSC (if any) */ lcls_update_config(conn, config, control); /* Do not attempt to perform correlation yet, as during processing of the ASS REQ * we don't have the MGCP/MGW connections yet, and hence couldn't enable LS. */ } /* TS 48.008 3.2.1.91 */ static int bssmap_handle_lcls_connect_ctrl(struct gsm_subscriber_connection *conn, struct msgb *msg, unsigned int length) { struct msgb *resp; struct tlv_parsed tp; const uint8_t *config, *control; int rc; OSMO_ASSERT(conn); rc = tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, length - 1, 0, 0); if (rc < 0) { LOGPFSML(conn->fi, LOGL_ERROR, "Error parsing TLVs of LCLS CONNT CTRL: %s\n", msgb_hexdump(msg)); return rc; } config = TLVP_VAL_MINLEN(&tp, GSM0808_IE_LCLS_CONFIG, 1); control = TLVP_VAL_MINLEN(&tp, GSM0808_IE_LCLS_CONN_STATUS_CTRL, 1); LOGPFSM(conn->fi, "Rx LCLS CONNECT CTRL (%s / %s)\n", config ? gsm0808_lcls_config_name(*config) : "NULL", control ? gsm0808_lcls_control_name(*control) : "NULL"); if (conn->lcls.global_call_ref_len == 0) { LOGPFSML(conn->fi, LOGL_ERROR, "Ignoring LCLS as no GCR was set before\n"); return 0; } /* Update the LCLS state with Config + CSC (if any) */ lcls_update_config(conn, TLVP_VAL_MINLEN(&tp, GSM0808_IE_LCLS_CONFIG, 1), TLVP_VAL_MINLEN(&tp, GSM0808_IE_LCLS_CONN_STATUS_CTRL, 1)); lcls_apply_config(conn); LOGPFSM(conn->fi, "Tx LCLS CONNECT CTRL ACK (%s)\n", gsm0808_lcls_status_name(lcls_get_status(conn))); resp = gsm0808_create_lcls_conn_ctrl_ack(lcls_get_status(conn)); rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_TX_DT1_LCLS_CONNECT_CTRL_ACK]); osmo_fsm_inst_dispatch(conn->fi, GSCON_EV_TX_SCCP, resp); return 0; } /* Select a preferred and an alternative codec rate depending on the available * capabilities. This decision does not include the actual channel load yet, * this is also the reason why the result is a preferred and an alternate * setting. The final decision is made in assignment_fsm.c when the actual * lchan is requested. The preferred lchan will be requested first. If we * find an alternate setting here, this one will be tried secondly if our * primary choice fails. */ static int select_codecs(struct assignment_request *req, struct gsm0808_channel_type *ct, struct gsm_subscriber_connection *conn) { int rc, i, nc = 0; struct bsc_msc_data *msc; struct gsm_bts *bts = conn_get_bts(conn); if (!bts) { LOGP(DMSC, LOGL_ERROR, "No lchan, cannot select codecs\n"); return -EINVAL; } msc = conn->sccp.msc; switch (ct->ch_rate_type) { case GSM0808_SPEECH_FULL_BM: rc = match_codec_pref(&req->ch_mode_rate[nc], ct, &conn->codec_list, msc, bts, RATE_PREF_FR); nc += (rc == 0); break; case GSM0808_SPEECH_HALF_LM: rc = match_codec_pref(&req->ch_mode_rate[nc], ct, &conn->codec_list, msc, bts, RATE_PREF_HR); nc += (rc == 0); break; case GSM0808_SPEECH_PERM: case GSM0808_SPEECH_PERM_NO_CHANGE: case GSM0808_SPEECH_FULL_PREF_NO_CHANGE: case GSM0808_SPEECH_FULL_PREF: rc = match_codec_pref(&req->ch_mode_rate[nc], ct, &conn->codec_list, msc, bts, RATE_PREF_FR); nc += (rc == 0); rc = match_codec_pref(&req->ch_mode_rate[nc], ct, &conn->codec_list, msc, bts, RATE_PREF_HR); nc += (rc == 0); break; case GSM0808_SPEECH_HALF_PREF_NO_CHANGE: case GSM0808_SPEECH_HALF_PREF: rc = match_codec_pref(&req->ch_mode_rate[nc], ct, &conn->codec_list, msc, bts, RATE_PREF_HR); nc += (rc == 0); rc = match_codec_pref(&req->ch_mode_rate[nc], ct, &conn->codec_list, msc, bts, RATE_PREF_FR); nc += (rc == 0); break; default: rc = -EINVAL; break; } if (!nc) { LOGP(DMSC, LOGL_ERROR, "No supported audio type found for channel_type =" " { ch_indctr=0x%x, ch_rate_type=0x%x, perm_spch=[%s] }\n", ct->ch_indctr, ct->ch_rate_type, osmo_hexdump(ct->perm_spch, ct->perm_spch_len)); /* TODO: actually output codec names, e.g. implement * gsm0808_permitted_speech_names[] and iterate perm_spch. */ return -EINVAL; } for (i = 0; i < nc; i++ ) { DEBUGP(DMSC, "Found matching audio type (pref=%d): %s %s for channel_type =" " { ch_indctr=0x%x, ch_rate_type=0x%x, perm_spch=[ %s] }\n", i, req->ch_mode_rate[i].chan_rate == CH_RATE_FULL ? "full rate" : "half rate", get_value_string(gsm48_chan_mode_names, req->ch_mode_rate[i].chan_mode), ct->ch_indctr, ct->ch_rate_type, osmo_hexdump(ct->perm_spch, ct->perm_spch_len)); } req->n_ch_mode_rate = nc; return 0; } static int select_sign_chan(struct assignment_request *req, struct gsm0808_channel_type *ct) { int i, nc = 0; switch (ct->ch_rate_type) { case GSM0808_SIGN_ANY: req->ch_mode_rate[nc++].chan_rate = CH_RATE_SDCCH; req->ch_mode_rate[nc++].chan_rate = CH_RATE_HALF; req->ch_mode_rate[nc++].chan_rate = CH_RATE_FULL; break; case GSM0808_SIGN_SDCCH: req->ch_mode_rate[nc++].chan_rate = CH_RATE_SDCCH; break; case GSM0808_SIGN_SDCCH_FULL_BM: req->ch_mode_rate[nc++].chan_rate = CH_RATE_SDCCH; req->ch_mode_rate[nc++].chan_rate = CH_RATE_FULL; break; case GSM0808_SIGN_SDCCH_HALF_LM: req->ch_mode_rate[nc++].chan_rate = CH_RATE_SDCCH; req->ch_mode_rate[nc++].chan_rate = CH_RATE_HALF; break; case GSM0808_SIGN_FULL_BM: req->ch_mode_rate[nc++].chan_rate = CH_RATE_FULL; break; case GSM0808_SIGN_HALF_LM: req->ch_mode_rate[nc++].chan_rate = CH_RATE_HALF; break; case GSM0808_SIGN_FULL_PREF: case GSM0808_SIGN_FULL_PREF_NO_CHANGE: req->ch_mode_rate[nc++].chan_rate = CH_RATE_FULL; req->ch_mode_rate[nc++].chan_rate = CH_RATE_HALF; break; case GSM0808_SIGN_HALF_PREF: case GSM0808_SIGN_HALF_PREF_NO_CHANGE: req->ch_mode_rate[nc++].chan_rate = CH_RATE_HALF; req->ch_mode_rate[nc++].chan_rate = CH_RATE_FULL; break; default: break; } for (i = 0; i < nc; i++) req->ch_mode_rate[i].chan_mode = GSM48_CMODE_SIGN; req->n_ch_mode_rate = nc; return nc > 0 ? 0 : -EINVAL; } /* * Handle the assignment request message. * * See §3.2.1.1 for the message type */ static int bssmap_handle_assignm_req(struct gsm_subscriber_connection *conn, struct msgb *msg, unsigned int length) { struct msgb *resp; struct tlv_parsed tp; uint16_t cic = 0; bool aoip = false; bool use_osmux = false; uint8_t osmux_cid = 0; struct sockaddr_storage rtp_addr; struct gsm0808_channel_type ct; uint8_t cause; int rc; struct assignment_request req = {}; if (!conn) { LOGP(DMSC, LOGL_ERROR, "No lchan/msc_data in Assignment Request\n"); return -1; } aoip = gscon_is_aoip(conn); tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, length - 1, 0, 0); /* Check for channel type element, if its missing, immediately reject */ if (!TLVP_PRESENT(&tp, GSM0808_IE_CHANNEL_TYPE)) { LOGP(DMSC, LOGL_ERROR, "Mandatory channel type not present.\n"); cause = GSM0808_CAUSE_INFORMATION_ELEMENT_OR_FIELD_MISSING; goto reject; } /* Decode Channel Type element */ rc = gsm0808_dec_channel_type(&ct, TLVP_VAL(&tp, GSM0808_IE_CHANNEL_TYPE), TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE)); if (rc < 0) { LOGP(DMSC, LOGL_ERROR, "unable to decode channel type.\n"); cause = GSM0808_CAUSE_INCORRECT_VALUE; goto reject; } bssmap_handle_ass_req_lcls(conn, &tp); /* Currently we only support a limited subset of all * possible channel types, such as multi-slot or CSD */ switch (ct.ch_indctr) { case GSM0808_CHAN_DATA: LOGP(DMSC, LOGL_ERROR, "Unsupported channel type, currently only speech is supported!\n"); cause = GSM0808_CAUSE_REQ_CODEC_TYPE_OR_CONFIG_NOT_SUPP; goto reject; case GSM0808_CHAN_SPEECH: if (TLVP_PRESENT(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)) { /* CIC is permitted in both AoIP and SCCPlite */ cic = osmo_load16be(TLVP_VAL(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)); } else { if (!aoip) { /* no CIC but SCCPlite: illegal */ LOGP(DMSC, LOGL_ERROR, "SCCPlite MSC, but no CIC in ASSIGN REQ?\n"); cause = GSM0808_CAUSE_INFORMATION_ELEMENT_OR_FIELD_MISSING; goto reject; } } if (TLVP_PRESENT(&tp, GSM0808_IE_AOIP_TRASP_ADDR)) { if (!aoip) { /* SCCPlite and AoIP transport address: illegal */ LOGP(DMSC, LOGL_ERROR, "AoIP Transport address over IPA ?!?\n"); cause = GSM0808_CAUSE_INCORRECT_VALUE; goto reject; } /* Decode AoIP transport address element */ rc = gsm0808_dec_aoip_trasp_addr(&rtp_addr, TLVP_VAL(&tp, GSM0808_IE_AOIP_TRASP_ADDR), TLVP_LEN(&tp, GSM0808_IE_AOIP_TRASP_ADDR)); if (rc < 0) { LOGP(DMSC, LOGL_ERROR, "Unable to decode AoIP transport address.\n"); cause = GSM0808_CAUSE_INCORRECT_VALUE; goto reject; } } else if (aoip) { /* no AoIP transport level address but AoIP transport: illegal */ LOGP(DMSC, LOGL_ERROR, "AoIP transport address missing in ASSIGN REQ, " "audio would not work; rejecting\n"); cause = GSM0808_CAUSE_INFORMATION_ELEMENT_OR_FIELD_MISSING; goto reject; } if (TLVP_PRESENT(&tp, GSM0808_IE_OSMO_OSMUX_CID)) { if (conn->sccp.msc->use_osmux == OSMUX_USAGE_OFF) { LOGP(DMSC, LOGL_ERROR, "MSC using Osmux but we have it disabled.\n"); cause = GSM0808_CAUSE_INCORRECT_VALUE; goto reject; } use_osmux = true; rc = gsm0808_dec_osmux_cid(&osmux_cid, TLVP_VAL(&tp, GSM0808_IE_OSMO_OSMUX_CID), TLVP_LEN(&tp, GSM0808_IE_OSMO_OSMUX_CID)); if (rc < 0) { LOGP(DMSC, LOGL_ERROR, "Unable to decode Osmux CID.\n"); cause = GSM0808_CAUSE_INCORRECT_VALUE; goto reject; } } else { if (conn->sccp.msc->use_osmux == OSMUX_USAGE_ONLY) { LOGP(DMSC, LOGL_ERROR, "MSC not using Osmux but we are forced to use it.\n"); cause = GSM0808_CAUSE_INCORRECT_VALUE; goto reject; } else if (conn->sccp.msc->use_osmux == OSMUX_USAGE_ON) LOGP(DMSC, LOGL_NOTICE, "MSC not using Osmux but we have Osmux enabled.\n"); } /* Decode speech codec list. First set len = 0. */ conn->codec_list = (struct gsm0808_speech_codec_list){}; /* Check for speech codec list element */ if (TLVP_PRESENT(&tp, GSM0808_IE_SPEECH_CODEC_LIST)) { /* Decode Speech Codec list */ rc = gsm0808_dec_speech_codec_list(&conn->codec_list, TLVP_VAL(&tp, GSM0808_IE_SPEECH_CODEC_LIST), TLVP_LEN(&tp, GSM0808_IE_SPEECH_CODEC_LIST)); if (rc < 0) { LOGP(DMSC, LOGL_ERROR, "Unable to decode speech codec list\n"); cause = GSM0808_CAUSE_INCORRECT_VALUE; goto reject; } } if (aoip && !conn->codec_list.len) { LOGP(DMSC, LOGL_ERROR, "%s: AoIP speech mode Assignment Request:" " Missing or empty Speech Codec List IE\n", bsc_subscr_name(conn->bsub)); cause = GSM0808_CAUSE_INFORMATION_ELEMENT_OR_FIELD_MISSING; goto reject; } req = (struct assignment_request){ .aoip = aoip, .msc_assigned_cic = cic, .use_osmux = use_osmux, .osmux_cid = osmux_cid, }; /* Match codec information from the assignment command against the * local preferences of the BSC and BTS */ rc = select_codecs(&req, &ct, conn); if (rc < 0) { cause = GSM0808_CAUSE_REQ_CODEC_TYPE_OR_CONFIG_UNAVAIL; goto reject; } if (aoip) { unsigned int rc = osmo_sockaddr_to_str_and_uint(req.msc_rtp_addr, sizeof(req.msc_rtp_addr), &req.msc_rtp_port, (const struct sockaddr*)&rtp_addr); if (!rc || rc >= sizeof(req.msc_rtp_addr)) { LOGP(DMSC, LOGL_ERROR, "Assignment request: RTP address is too long\n"); cause = GSM0808_CAUSE_REQ_CODEC_TYPE_OR_CONFIG_UNAVAIL; goto reject; } } break; case GSM0808_CHAN_SIGN: req = (struct assignment_request){ .aoip = aoip, }; rc = select_sign_chan(&req, &ct); if (rc < 0) { cause = GSM0808_CAUSE_INCORRECT_VALUE; goto reject; } break; default: cause = GSM0808_CAUSE_INVALID_MESSAGE_CONTENTS; goto reject; } return osmo_fsm_inst_dispatch(conn->fi, GSCON_EV_ASSIGNMENT_START, &req); reject: resp = gsm0808_create_assignment_failure(cause, NULL); OSMO_ASSERT(resp); rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_TX_DT1_ASSIGMENT_FAILURE]); osmo_fsm_inst_dispatch(conn->fi, GSCON_EV_TX_SCCP, resp); return -1; } /* Handle Handover Command message, part of inter-BSC handover: * This BSS sent a Handover Required message. * The MSC contacts the remote BSS and receives from it an RR Handover Command; this BSSMAP Handover * Command passes the RR Handover Command over to us and it's our job to forward to the MS. * * See 3GPP TS 48.008 §3.2.1.11 */ static int bssmap_handle_handover_cmd(struct gsm_subscriber_connection *conn, struct msgb *msg, unsigned int length) { struct tlv_parsed tp; if (!conn->ho.fi) { LOGPFSML(conn->fi, LOGL_ERROR, "Received Handover Command, but no handover was requested\n"); /* Should we actually allow the MSC to make us handover without us having requested it * first? Doesn't make any practical sense AFAICT. */ return -EINVAL; } tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, length - 1, 0, 0); /* Check for channel type element, if its missing, immediately reject */ if (!TLVP_PRESENT(&tp, GSM0808_IE_LAYER_3_INFORMATION)) { LOGPFSML(conn->fi, LOGL_ERROR, "Received Handover Command," " but mandatory IE not present: Layer 3 Information\n"); goto reject; } /* Due to constness, need to declare this after tlv_parse(). */ struct ho_out_rx_bssmap_ho_command rx = { .l3_info = TLVP_VAL(&tp, GSM0808_IE_LAYER_3_INFORMATION), .l3_info_len = TLVP_LEN(&tp, GSM0808_IE_LAYER_3_INFORMATION), }; osmo_fsm_inst_dispatch(conn->ho.fi, HO_OUT_EV_BSSMAP_HO_COMMAND, &rx); return 0; reject: /* No "Handover Command Reject" message or similar is specified, so we cannot reply in case of * failure. Or is there?? */ handover_end(conn, HO_RESULT_ERROR); return -EINVAL; } /* Handle Confusion message, MSC indicating an error to us: * * See 3GPP TS 48.008 §3.2.1.45 */ static int bssmap_handle_confusion(struct gsm_subscriber_connection *conn, struct msgb *msg, unsigned int length) { struct tlv_parsed tp; int diag_len; enum gsm0808_cause cause; enum gsm0808_cause_class cause_class; struct gsm0808_diagnostics *diag; osmo_bssap_tlv_parse(&tp, msg->l4h + 1, length - 1); /* Check for the Cause and Diagnostic mandatory elements */ if (!TLVP_PRESENT(&tp, GSM0808_IE_CAUSE) || !TLVP_PRESENT(&tp, GSM0808_IE_DIAGNOSTIC)) { LOGPFSML(conn->fi, LOGL_ERROR, "Received BSSMAP Confusion message," " but either Cause or Diagnostic mandatory IE is not present: %s\n", osmo_hexdump(msg->l4h, length)); return -EINVAL; } diag_len = TLVP_LEN(&tp, GSM0808_IE_DIAGNOSTIC); if (diag_len < 5) { LOGPFSML(conn->fi, LOGL_ERROR, "Received BSSMAP Confusion message with short Diagnostic length: %d (expected > 5)\n", diag_len); return -EINVAL; } cause = gsm0808_get_cause(&tp); cause_class = gsm0808_cause_class(cause); diag = (struct gsm0808_diagnostics *)TLVP_VAL(&tp, GSM0808_IE_DIAGNOSTIC); LOGPFSML(conn->fi, LOGL_ERROR, "Received BSSMAP Confusion: class 0x%x (%s), cause 0x%x (%s), " "error octet %d (%s), error bit %d (%s), original message: %s\n", cause_class, gsm0808_cause_class_name(cause_class), cause, gsm0808_cause_name(cause), diag->error_pointer_octet, gsm0808_diagnostics_octet_location_str(diag->error_pointer_octet), diag->error_pointer_bit, gsm0808_diagnostics_bit_location_str(diag->error_pointer_bit), osmo_hexdump(diag->msg, diag_len-2)); return 0; } static int bssmap_rcvmsg_udt(struct bsc_msc_data *msc, struct msgb *msg, unsigned int length) { int ret = 0; struct rate_ctr *ctrs = msc->msc_ctrs->ctr; if (length < 1) { LOGP(DMSC, LOGL_ERROR, "Not enough room: %d\n", length); return -1; } LOGP(DMSC, LOGL_INFO, "Rx MSC UDT BSSMAP %s\n", gsm0808_bssmap_name(msg->l4h[0])); switch (msg->l4h[0]) { case BSS_MAP_MSG_RESET_ACKNOWLEDGE: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_UDT_RESET_ACKNOWLEDGE]); ret = bssmap_handle_reset_ack(msc, msg, length); break; case BSS_MAP_MSG_RESET: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_UDT_RESET]); ret = bssmap_handle_reset(msc, msg, length); break; case BSS_MAP_MSG_PAGING: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_UDT_PAGING]); ret = bssmap_handle_paging(msc, msg, length); break; default: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_UDT_UNKNOWN]); LOGP(DMSC, LOGL_NOTICE, "Received unimplemented BSSMAP UDT %s\n", gsm0808_bssmap_name(msg->l4h[0])); break; } return ret; } static int bssmap_rcvmsg_dt1(struct gsm_subscriber_connection *conn, struct msgb *msg, unsigned int length) { int ret = 0; struct rate_ctr *ctrs = conn->sccp.msc->msc_ctrs->ctr; if (length < 1) { LOGP(DMSC, LOGL_ERROR, "Not enough room: %d\n", length); return -1; } LOGP(DMSC, LOGL_INFO, "Rx MSC DT1 BSSMAP %s\n", gsm0808_bssmap_name(msg->l4h[0])); switch (msg->l4h[0]) { case BSS_MAP_MSG_CLEAR_CMD: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_CLEAR_CMD]); ret = bssmap_handle_clear_cmd(conn, msg, length); break; case BSS_MAP_MSG_CIPHER_MODE_CMD: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_CIPHER_MODE_CMD]); ret = bssmap_handle_cipher_mode(conn, msg, length); break; case BSS_MAP_MSG_ASSIGMENT_RQST: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_ASSIGMENT_RQST]); ret = bssmap_handle_assignm_req(conn, msg, length); break; case BSS_MAP_MSG_LCLS_CONNECT_CTRL: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_LCLS_CONNECT_CTRL]); ret = bssmap_handle_lcls_connect_ctrl(conn, msg, length); break; case BSS_MAP_MSG_HANDOVER_CMD: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_HANDOVER_CMD]); ret = bssmap_handle_handover_cmd(conn, msg, length); break; case BSS_MAP_MSG_CLASSMARK_RQST: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_CLASSMARK_RQST]); ret = gsm48_send_rr_classmark_enquiry(conn->lchan); break; case BSS_MAP_MSG_CONFUSION: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_CONFUSION]); ret = bssmap_handle_confusion(conn, msg, length); break; default: rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_UNKNOWN]); LOGP(DMSC, LOGL_NOTICE, "Unimplemented msg type: %s\n", gsm0808_bssmap_name(msg->l4h[0])); break; } return ret; } static int dtap_rcvmsg(struct gsm_subscriber_connection *conn, struct msgb *msg, unsigned int length) { struct dtap_header *header; struct msgb *gsm48; uint8_t *data; int dtap_rc; struct rate_ctr *ctrs; LOGP(DMSC, LOGL_DEBUG, "Rx MSC DTAP: %s\n", osmo_hexdump(msg->l3h, length)); if (!conn) { LOGP(DMSC, LOGL_ERROR, "No subscriber connection available\n"); return -1; } ctrs = conn->sccp.msc->msc_ctrs->ctr; header = (struct dtap_header *) msg->l3h; if (sizeof(*header) >= length) { rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_DTAP_ERROR]); LOGP(DMSC, LOGL_ERROR, "The DTAP header does not fit. Wanted: %zu got: %u, hex: %s\n", sizeof(*header), length, osmo_hexdump(msg->l3h, length)); return -1; } if (header->length > length - sizeof(*header)) { rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_DTAP_ERROR]); LOGP(DMSC, LOGL_ERROR, "The DTAP l4 information does not fit. Wanted: %u got: %zu, hex: %s\n", header->length, length - sizeof(*header), osmo_hexdump(msg->l3h, length)); return -1; } rate_ctr_inc(&ctrs[MSC_CTR_BSSMAP_RX_DT1_DTAP]); LOGP(DMSC, LOGL_INFO, "Rx MSC DTAP, SAPI: %u CHAN: %u\n", header->link_id & 0x07, header->link_id & 0xC0); /* forward the data */ gsm48 = gsm48_msgb_alloc_name("GSM 04.08 DTAP RCV"); if (!gsm48) { LOGP(DMSC, LOGL_ERROR, "Allocation of the message failed.\n"); return -1; } gsm48->l3h = gsm48->data; data = msgb_put(gsm48, length - sizeof(*header)); memcpy(data, msg->l3h + sizeof(*header), length - sizeof(*header)); /* pass it to the filter for extra actions */ bsc_scan_msc_msg(conn, gsm48); /* Store link_id in msgb->cb */ OBSC_LINKID_CB(gsm48) = header->link_id; dtap_rc = osmo_fsm_inst_dispatch(conn->fi, GSCON_EV_MT_DTAP, gsm48); return dtap_rc; } int bsc_handle_udt(struct bsc_msc_data *msc, struct msgb *msgb, unsigned int length) { struct bssmap_header *bs; LOGP(DMSC, LOGL_DEBUG, "Rx MSC UDT: %s\n", osmo_hexdump(msgb->l3h, length)); if (length < sizeof(*bs)) { LOGP(DMSC, LOGL_ERROR, "The header is too short.\n"); return -1; } bs = (struct bssmap_header *) msgb->l3h; if (bs->length < length - sizeof(*bs)) return -1; switch (bs->type) { case BSSAP_MSG_BSS_MANAGEMENT: msgb->l4h = &msgb->l3h[sizeof(*bs)]; bssmap_rcvmsg_udt(msc, msgb, length - sizeof(*bs)); break; default: LOGP(DMSC, LOGL_NOTICE, "Unimplemented msg type: %s\n", gsm0808_bssmap_name(bs->type)); } return 0; } /* Extract and verify the length information from the BSSMAP header. */ static unsigned int bssmap_msg_len(struct msgb *msg, unsigned int length, const struct gsm_subscriber_connection *conn) { unsigned int expected_len; unsigned int calculated_len; struct bssmap_header *bssmap_header; bssmap_header = (struct bssmap_header *)msg->l3h; calculated_len = length - sizeof(struct bssmap_header); expected_len = bssmap_header->length; /* In case of contradictory length information, decide for the * shorter length */ if (calculated_len > expected_len) { LOGPFSML(conn->fi, LOGL_NOTICE, "BSSMAP message contains extra data, expected %u bytes, got %u bytes, truncated\n", expected_len, calculated_len); return expected_len; } else if (calculated_len < expected_len) { LOGPFSML(conn->fi, LOGL_NOTICE, "Short BSSMAP message, expected %u bytes, got %u bytes\n", expected_len, calculated_len); return calculated_len; } return expected_len; } int bsc_handle_dt(struct gsm_subscriber_connection *conn, struct msgb *msg, unsigned int len) { log_set_context(LOG_CTX_BSC_SUBSCR, conn->bsub); if (len < sizeof(struct bssmap_header)) { LOGP(DMSC, LOGL_ERROR, "The header is too short.\n"); } switch (msg->l3h[0]) { case BSSAP_MSG_BSS_MANAGEMENT: msg->l4h = &msg->l3h[sizeof(struct bssmap_header)]; bssmap_rcvmsg_dt1(conn, msg, bssmap_msg_len(msg, len, conn)); break; case BSSAP_MSG_DTAP: dtap_rcvmsg(conn, msg, len); break; default: LOGP(DMSC, LOGL_NOTICE, "Unimplemented BSSAP msg type: %s\n", gsm0808_bssap_name(msg->l3h[0])); } log_set_context(LOG_CTX_BSC_SUBSCR, NULL); return -1; } int bsc_tx_bssmap_ho_required(struct gsm_lchan *lchan, const struct gsm0808_cell_id_list2 *target_cells) { int rc; struct msgb *msg; struct gsm0808_handover_required params = { .cause = GSM0808_CAUSE_BETTER_CELL, .cil = *target_cells, .current_channel_type_1_present = true, .current_channel_type_1 = gsm0808_current_channel_type_1(lchan->type), }; switch (lchan->type) { case GSM_LCHAN_TCH_F: case GSM_LCHAN_TCH_H: params.speech_version_used_present = true; params.speech_version_used = gsm0808_permitted_speech(lchan->type, lchan->tch_mode); if (!params.speech_version_used) { LOG_HO(lchan->conn, LOGL_ERROR, "Cannot encode Speech Version (Used)" " for BSSMAP Handover Required message\n"); return -EINVAL; } break; default: break; } msg = gsm0808_create_handover_required(¶ms); if (!msg) { LOG_HO(lchan->conn, LOGL_ERROR, "Cannot compose BSSMAP Handover Required message\n"); return -EINVAL; } rate_ctr_inc(&lchan->conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_TX_DT1_HANDOVER_REQUIRED]); rc = gscon_sigtran_send(lchan->conn, msg); if (rc) { LOG_HO(lchan->conn, LOGL_ERROR, "Cannot send BSSMAP Handover Required message\n"); return rc; } return 0; } /* Inter-BSC MT HO, new BSS has allocated a channel and sends the RR Handover Command via MSC to the old * BSS, encapsulated in a BSSMAP Handover Request Acknowledge. */ int bsc_tx_bssmap_ho_request_ack(struct gsm_subscriber_connection *conn, struct msgb *rr_ho_command) { struct msgb *msg; struct gsm_lchan *new_lchan = conn->ho.new_lchan; struct sockaddr_storage ss; struct gsm0808_handover_request_ack params = { .l3_info = rr_ho_command->data, .l3_info_len = rr_ho_command->len, .chosen_channel_present = true, .chosen_channel = gsm0808_chosen_channel(new_lchan->type, new_lchan->tch_mode), .chosen_encr_alg = new_lchan->encr.alg_id, .chosen_speech_version = gsm0808_permitted_speech(new_lchan->type, new_lchan->tch_mode), }; if (gscon_is_aoip(conn)) { struct osmo_sockaddr_str to_msc_rtp; const struct mgcp_conn_peer *rtp_info = osmo_mgcpc_ep_ci_get_rtp_info(conn->user_plane.mgw_endpoint_ci_msc); if (!rtp_info) { LOG_HO(conn, LOGL_ERROR, "Handover Request Acknowledge: no RTP address known to send as" " AoIP Transport Layer Address\n"); return -EINVAL; } if (osmo_sockaddr_str_from_str(&to_msc_rtp, rtp_info->addr, rtp_info->port)) { LOG_HO(conn, LOGL_ERROR, "Handover Request Acknowledge: cannot encode AoIP Transport Layer\n"); return -EINVAL; } if (osmo_sockaddr_str_to_sockaddr(&to_msc_rtp, &ss)) { LOG_HO(conn, LOGL_ERROR, "Handover Request Acknowledge: cannot encode AoIP Transport Layer\n"); return -EINVAL; } params.aoip_transport_layer = &ss; } rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_TX_DT1_HANDOVER_RQST_ACKNOWLEDGE]); LOG_HO(conn, LOGL_DEBUG, "Sending BSSMAP Handover Request Acknowledge\n"); msg = gsm0808_create_handover_request_ack2(¶ms); msgb_free(rr_ho_command); if (!msg) return -ENOMEM; return osmo_bsc_sigtran_send(conn, msg); } int bsc_tx_bssmap_ho_detect(struct gsm_subscriber_connection *conn) { struct msgb *msg; msg = gsm0808_create_handover_detect(); if (!msg) return -ENOMEM; rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_TX_DT1_HANDOVER_DETECT]); return osmo_bsc_sigtran_send(conn, msg); } enum handover_result bsc_tx_bssmap_ho_complete(struct gsm_subscriber_connection *conn, struct gsm_lchan *lchan) { int rc; struct msgb *msg; struct handover *ho = &conn->ho; enum gsm0808_lcls_status lcls_status = lcls_get_status(conn); struct gsm0808_handover_complete params = { .chosen_encr_alg_present = true, .chosen_encr_alg = lchan->encr.alg_id, .chosen_channel_present = true, .chosen_channel = gsm0808_chosen_channel(lchan->type, lchan->tch_mode), .lcls_bss_status_present = (lcls_status != 0xff), .lcls_bss_status = lcls_status, }; /* speech_codec_chosen */ if (ho->new_lchan->activate.info.requires_voice_stream && gscon_is_aoip(conn)) { int perm_spch = gsm0808_permitted_speech(lchan->type, lchan->tch_mode); params.speech_codec_chosen_present = true; rc = gsm0808_speech_codec_from_chan_type(¶ms.speech_codec_chosen, perm_spch); if (rc) { LOG_HO(conn, LOGL_ERROR, "Unable to compose Speech Codec (Chosen)\n"); return HO_RESULT_ERROR; } } msg = gsm0808_create_handover_complete(¶ms); if (!msg) { LOG_HO(conn, LOGL_ERROR, "Unable to compose BSSMAP Handover Complete message\n"); return HO_RESULT_ERROR; } rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_TX_DT1_HANDOVER_COMPLETE]); rc = osmo_bsc_sigtran_send(conn, msg); if (rc) { LOG_HO(conn, LOGL_ERROR, "Cannot send BSSMAP Handover Complete message\n"); return HO_RESULT_ERROR; } return HO_RESULT_OK; } void bsc_tx_bssmap_ho_failure(struct gsm_subscriber_connection *conn) { int rc; struct msgb *msg; struct gsm0808_handover_failure params = {}; msg = gsm0808_create_handover_failure(¶ms); if (!msg) { LOG_HO(conn, LOGL_ERROR, "Unable to compose BSSMAP Handover Failure message\n"); return; } rate_ctr_inc(&conn->sccp.msc->msc_ctrs->ctr[MSC_CTR_BSSMAP_TX_DT1_HANDOVER_FAILURE]); rc = osmo_bsc_sigtran_send(conn, msg); if (rc) LOG_HO(conn, LOGL_ERROR, "Cannot send BSSMAP Handover Failure message (rc=%d %s)\n", rc, strerror(-rc)); }