| /* BSSAP/BSSMAP encoding and decoding for MSC */ |
| /* |
| * (C) 2019 by sysmocom - s.m.f.c. GmbH <info@sysmocom.de> |
| * All Rights Reserved |
| * |
| * Author: Neels Hofmeyr |
| * |
| * SPDX-License-Identifier: GPL-2.0+ |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 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 General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| */ |
| |
| #include <osmocom/core/byteswap.h> |
| |
| #include <osmocom/crypt/auth.h> |
| #include <osmocom/crypt/kdf.h> |
| |
| #include <osmocom/gsm/tlv.h> |
| #include <osmocom/gsm/gsm0808.h> |
| #include <osmocom/gsm/mncc.h> |
| #include <osmocom/gsm/gsm48.h> |
| |
| #include <osmocom/msc/debug.h> |
| #include <osmocom/msc/ran_msg_a.h> |
| #include <osmocom/msc/sccp_ran.h> |
| #include <osmocom/msc/gsm_data.h> |
| |
| #define LOG_RAN_A_DEC(RAN_DEC, level, fmt, args...) \ |
| LOG_RAN_DEC(RAN_DEC, DBSSAP, level, "BSSMAP: " fmt, ## args) |
| |
| /* Assumes presence of struct ran_dec *ran_dec and ran_dec_msg.msg_name (set) in the local scope. */ |
| #define LOG_RAN_A_DEC_MSG(level, fmt, args...) \ |
| LOG_RAN_DEC(ran_dec, DBSSAP, level, "%s: " fmt, ran_dec_msg.msg_name, ## args) |
| |
| #define LOG_RAN_A_ENC(FI, level, fmt, args...) \ |
| LOG_RAN_ENC(FI, DBSSAP, level, "BSSMAP: " fmt, ## args) |
| |
| static int ran_a_decode_l3_compl(struct ran_dec *ran_dec, struct msgb *msg, struct tlv_parsed *tp) |
| { |
| struct gsm0808_cell_id_list2 cil; |
| struct gsm0808_cell_id cell_id; |
| struct tlv_p_entry *ie_cell_id = TLVP_GET(tp, GSM0808_IE_CELL_IDENTIFIER); |
| struct tlv_p_entry *ie_l3_info = TLVP_GET(tp, GSM0808_IE_LAYER_3_INFORMATION); |
| struct tlv_p_entry *ie_codec_list_bss_supported = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC_LIST); |
| struct gsm0808_speech_codec_list codec_list_bss_supported; |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_COMPL_L3, |
| .msg_name = "BSSMAP Complete Layer 3 Information", |
| .compl_l3 = { |
| .cell_id = &cell_id, |
| .msg = msg, |
| }, |
| }; |
| int rc; |
| |
| if (!ie_cell_id) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Mandatory CELL IDENTIFIER not present, discarding message\n"); |
| return -EINVAL; |
| } |
| if (!ie_l3_info) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Mandatory LAYER 3 INFORMATION not present, discarding message\n"); |
| return -EINVAL; |
| } |
| |
| /* Parse Cell ID element -- this should yield a cell identifier "list" with 1 element. */ |
| |
| rc = gsm0808_dec_cell_id_list2(&cil, ie_cell_id->val, ie_cell_id->len); |
| if (rc < 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Decoding CELL IDENTIFIER gave rc=%d\n", rc); |
| return -EINVAL; |
| } |
| if (cil.id_list_len != 1) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Unable to parse element CELL IDENTIFIER, discarding message\n"); |
| return -EINVAL; |
| } |
| |
| /* Sanity check the Cell Identity */ |
| switch (cil.id_discr) { |
| case CELL_IDENT_WHOLE_GLOBAL: |
| case CELL_IDENT_LAI_AND_LAC: |
| case CELL_IDENT_LAC_AND_CI: |
| case CELL_IDENT_LAC: |
| break; |
| |
| case CELL_IDENT_CI: |
| case CELL_IDENT_NO_CELL: |
| case CELL_IDENT_BSS: |
| default: |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "CELL IDENTIFIER does not specify a LAC, discarding message: %s\n", |
| gsm0808_cell_id_list_name(&cil)); |
| return -EINVAL; |
| } |
| |
| cell_id = (struct gsm0808_cell_id){ |
| .id_discr = cil.id_discr, |
| .id = cil.id_list[0], |
| }; |
| |
| /* Parse Layer 3 Information element */ |
| msg->l3h = (uint8_t*)ie_l3_info->val; |
| msgb_l3trim(msg, ie_l3_info->len); |
| |
| if (msgb_l3len(msg) < sizeof(struct gsm48_hdr)) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "too short L3 info (%d), discarding message\n", msgb_l3len(msg)); |
| return -ENODATA; |
| } |
| |
| /* Decode Codec List (BSS Supported) */ |
| if (ie_codec_list_bss_supported) { |
| rc = gsm0808_dec_speech_codec_list(&codec_list_bss_supported, |
| ie_codec_list_bss_supported->val, ie_codec_list_bss_supported->len); |
| if (rc < 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, |
| "Complete Layer 3 Information: unable to decode IE Codec List (BSS Supported)" |
| " (rc=%d), continuing anyway\n", rc); |
| /* This IE is not critical, do not abort with error. */ |
| } else |
| ran_dec_msg.compl_l3.codec_list_bss_supported = &codec_list_bss_supported; |
| } |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_clear_request(struct ran_dec *ran_dec, struct msgb *msg, struct tlv_parsed *tp) |
| { |
| struct tlv_p_entry *ie_cause = TLVP_GET(tp, GSM0808_IE_CAUSE); |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_CLEAR_REQUEST, |
| .msg_name = "BSSMAP Clear Request", |
| }; |
| |
| if (!ie_cause) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Cause code is missing, using GSM0808_CAUSE_EQUIPMENT_FAILURE\n"); |
| ran_dec_msg.clear_request.bssap_cause = GSM0808_CAUSE_EQUIPMENT_FAILURE; |
| } else { |
| ran_dec_msg.clear_request.bssap_cause = ie_cause->val[0]; |
| } |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_clear_complete(struct ran_dec *ran_dec, struct msgb *msg, struct tlv_parsed *tp) |
| { |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_CLEAR_COMPLETE, |
| .msg_name = "BSSMAP Clear Complete", |
| }; |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_classmark_update(struct ran_dec *ran_dec, struct msgb *msg, struct tlv_parsed *tp) |
| { |
| struct tlv_p_entry *ie_cm2 = TLVP_GET(tp, GSM0808_IE_CLASSMARK_INFORMATION_T2); |
| struct tlv_p_entry *ie_cm3 = TLVP_GET(tp, GSM0808_IE_CLASSMARK_INFORMATION_T3); |
| struct osmo_gsm48_classmark cm = {}; |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_CLASSMARK_UPDATE, |
| .msg_name = "BSSMAP Classmark Update", |
| .classmark_update = { |
| .classmark = &cm, |
| }, |
| }; |
| |
| if (!ie_cm2) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "mandatory Classmark Information Type 2 not present, discarding message\n"); |
| return -EINVAL; |
| } |
| |
| cm.classmark2_len = OSMO_MIN(sizeof(cm.classmark2), ie_cm2->len); |
| memcpy(&cm.classmark2, ie_cm2->val, cm.classmark2_len); |
| |
| if (ie_cm3) { |
| cm.classmark3_len = OSMO_MIN(sizeof(cm.classmark3), ie_cm3->len); |
| memcpy(&cm.classmark3, ie_cm3->val, cm.classmark3_len); |
| } |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_cipher_mode_complete(struct ran_dec *ran_dec, struct msgb *msg, struct tlv_parsed *tp) |
| { |
| struct tlv_p_entry *ie_chosen_encr_alg = TLVP_GET(tp, GSM0808_IE_CHOSEN_ENCR_ALG); |
| struct tlv_p_entry *ie_l3_msg = TLVP_GET(tp, GSM0808_IE_LAYER_3_MESSAGE_CONTENTS); |
| int rc; |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_CIPHER_MODE_COMPLETE, |
| .msg_name = "BSSMAP Ciphering Mode Complete", |
| }; |
| |
| if (ie_chosen_encr_alg) { |
| uint8_t ie_val = ie_chosen_encr_alg->val[0]; |
| /* 3GPP TS 48.008 3.2.2.44 Chosen Encryption Algorithm encodes as 1 = no encryption, 2 = A5/1, 4 = A5/3. |
| * Internally we handle without this weird off-by-one. */ |
| if (ie_val < 1 || ie_val > 8) |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Unsupported value for 3.2.2.44 Chosen Encryption Algorithm: %u\n", |
| ie_val); |
| else |
| ran_dec_msg.cipher_mode_complete.alg_id = ie_chosen_encr_alg->val[0]; |
| } |
| |
| if (ie_l3_msg) |
| ran_dec_msg.cipher_mode_complete.l3_msg = ie_l3_msg; |
| |
| rc = ran_decoded(ran_dec, &ran_dec_msg); |
| |
| return rc; |
| } |
| |
| static int ran_a_decode_cipher_mode_reject(struct ran_dec *ran_dec, struct msgb *msg, struct tlv_parsed *tp) |
| { |
| int rc; |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_CIPHER_MODE_REJECT, |
| .msg_name = "BSSMAP Ciphering Mode Reject", |
| }; |
| |
| rc = gsm0808_get_cause(tp); |
| if (rc < 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "failed to extract Cause\n"); |
| ran_dec_msg.cipher_mode_reject.bssap_cause = GSM0808_CAUSE_EQUIPMENT_FAILURE; |
| } else { |
| ran_dec_msg.cipher_mode_reject.bssap_cause = (enum gsm0808_cause)rc; |
| } |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| enum mgcp_codecs ran_a_mgcp_codec_from_sc(const struct gsm0808_speech_codec *sc) |
| { |
| switch (sc->type) { |
| case GSM0808_SCT_FR1: |
| return CODEC_GSM_8000_1; |
| break; |
| case GSM0808_SCT_FR2: |
| return CODEC_GSMEFR_8000_1; |
| break; |
| case GSM0808_SCT_FR3: |
| return CODEC_AMR_8000_1; |
| break; |
| case GSM0808_SCT_FR4: |
| return CODEC_AMRWB_16000_1; |
| break; |
| case GSM0808_SCT_FR5: |
| return CODEC_AMRWB_16000_1; |
| break; |
| case GSM0808_SCT_HR1: |
| return CODEC_GSMHR_8000_1; |
| break; |
| case GSM0808_SCT_HR3: |
| return CODEC_AMR_8000_1; |
| break; |
| case GSM0808_SCT_HR4: |
| return CODEC_AMRWB_16000_1; |
| break; |
| case GSM0808_SCT_HR6: |
| return CODEC_AMRWB_16000_1; |
| break; |
| default: |
| return CODEC_PCMU_8000_1; |
| break; |
| } |
| } |
| |
| static int ran_a_decode_assignment_complete(struct ran_dec *ran_dec, struct msgb *msg, struct tlv_parsed *tp) |
| { |
| struct tlv_p_entry *ie_aoip_transp_addr = TLVP_GET(tp, GSM0808_IE_AOIP_TRASP_ADDR); |
| struct tlv_p_entry *ie_speech_codec = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC); |
| struct tlv_p_entry *ie_codec_list_bss_supported = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC_LIST); |
| struct tlv_p_entry *ie_osmux_cid = TLVP_GET(tp, GSM0808_IE_OSMO_OSMUX_CID); |
| struct sockaddr_storage rtp_addr; |
| struct gsm0808_speech_codec sc; |
| struct gsm0808_speech_codec_list codec_list_bss_supported; |
| int rc; |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_ASSIGNMENT_COMPLETE, |
| .msg_name = "BSSMAP Assignment Complete", |
| }; |
| |
| if (ie_aoip_transp_addr) { |
| /* Decode AoIP transport address element */ |
| rc = gsm0808_dec_aoip_trasp_addr(&rtp_addr, ie_aoip_transp_addr->val, ie_aoip_transp_addr->len); |
| if (rc < 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Unable to decode AoIP Transport Layer Address\n"); |
| return -EINVAL; |
| } |
| |
| if (osmo_sockaddr_str_from_sockaddr(&ran_dec_msg.assignment_complete.remote_rtp, &rtp_addr)) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Assignment Complete: unable to decode remote RTP IP address\n"); |
| return -EINVAL; |
| } |
| } |
| |
| if (ie_osmux_cid) { |
| rc = gsm0808_dec_osmux_cid(&ran_dec_msg.assignment_complete.osmux_cid, ie_osmux_cid->val, ie_osmux_cid->len); |
| if (rc < 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Unable to decode Osmux CID\n"); |
| return -EINVAL; |
| } |
| ran_dec_msg.assignment_complete.osmux_present = true; |
| } |
| |
| if (ie_speech_codec) { |
| /* Decode Speech Codec (Chosen) element */ |
| rc = gsm0808_dec_speech_codec(&sc, ie_speech_codec->val, ie_speech_codec->len); |
| if (rc < 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Assignment Complete: unable to decode IE Speech Codec (Chosen)" |
| " (rc=%d).\n", rc); |
| return -EINVAL; |
| } |
| ran_dec_msg.assignment_complete.codec_present = true; |
| ran_dec_msg.assignment_complete.codec = ran_a_mgcp_codec_from_sc(&sc); |
| } |
| |
| if (ie_codec_list_bss_supported) { |
| /* Decode Codec List (BSS Supported) */ |
| rc = gsm0808_dec_speech_codec_list(&codec_list_bss_supported, |
| ie_codec_list_bss_supported->val, ie_codec_list_bss_supported->len); |
| if (rc < 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, |
| "Assignment Complete: unable to decode IE Codec List (BSS Supported)" |
| " (rc=%d), continuing anyway\n", rc); |
| /* This IE is not critical, do not abort with error. */ |
| } else |
| ran_dec_msg.assignment_complete.codec_list_bss_supported = &codec_list_bss_supported; |
| } |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_assignment_failure(struct ran_dec *ran_dec, struct msgb *msg, struct tlv_parsed *tp) |
| { |
| struct tlv_p_entry *ie_cause = TLVP_GET(tp, GSM0808_IE_CAUSE); |
| struct tlv_p_entry *ie_rr_cause = TLVP_GET(tp, GSM0808_IE_RR_CAUSE); |
| struct tlv_p_entry *ie_speech_codec_list = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC_LIST); |
| struct gsm0808_speech_codec_list scl; |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_ASSIGNMENT_FAILURE, |
| .msg_name = "BSSMAP Assignment Failure", |
| .assignment_failure = { |
| .bssap_cause = GSM0808_CAUSE_EQUIPMENT_FAILURE, |
| .rr_cause = GSM48_RR_CAUSE_ABNORMAL_UNSPEC, |
| }, |
| }; |
| |
| if (ie_cause) |
| ran_dec_msg.assignment_failure.bssap_cause = ie_cause->val[0]; |
| if (ie_rr_cause) |
| ran_dec_msg.assignment_failure.rr_cause = ie_rr_cause->val[0]; |
| |
| if (ie_speech_codec_list |
| && gsm0808_dec_speech_codec_list(&scl, ie_speech_codec_list->val, ie_speech_codec_list->len) == 0) |
| ran_dec_msg.assignment_failure.scl_bss_supported = &scl; |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_sapi_n_reject(struct ran_dec *ran_dec, struct msgb *msg, struct tlv_parsed *tp) |
| { |
| struct tlv_p_entry *ie_cause = TLVP_GET(tp, GSM0808_IE_CAUSE); |
| struct tlv_p_entry *ie_dlci = TLVP_GET(tp, GSM0808_IE_DLCI); |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_SAPI_N_REJECT, |
| .msg_name = "BSSMAP SAPI-N Reject", |
| }; |
| |
| /* Note: The MSC code seems not to care about the cause code, but by |
| * the specification it is mandatory, so we check its presence. See |
| * also 3GPP TS 48.008 3.2.1.34 SAPI "n" REJECT */ |
| if (!ie_cause) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "SAPI-N Reject: cause code IE is missing, discarding message\n"); |
| return -EINVAL; |
| } |
| ran_dec_msg.sapi_n_reject.bssap_cause = ie_cause->val[0]; |
| |
| if (!ie_dlci) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "SAPI-N Reject: DLCI IE is missing, discarding message\n"); |
| return -EINVAL; |
| } |
| ran_dec_msg.sapi_n_reject.dlci = ie_dlci->val[0]; |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_lcls_notification(struct ran_dec *ran_dec, const struct msgb *msg, const struct tlv_parsed *tp) |
| { |
| const struct tlv_p_entry *ie_lcls_bss_status = TLVP_GET(tp, GSM0808_IE_LCLS_BSS_STATUS); |
| const struct tlv_p_entry *ie_lcls_break_req = TLVP_GET(tp, GSM0808_IE_LCLS_BREAK_REQ); |
| struct ran_msg ran_dec_msg; |
| |
| /* Either §3.2.2.119 LCLS-BSS-Status or §3.2.2.120 LCLS-Break-Request shall be present */ |
| if (ie_lcls_bss_status && !ie_lcls_break_req) { |
| ran_dec_msg = (struct ran_msg){ |
| .msg_type = RAN_MSG_LCLS_STATUS, |
| .msg_name = "BSSMAP LCLS Notification (LCLS Status)", |
| .lcls_status = { |
| .status = ie_lcls_bss_status->len ? |
| ie_lcls_bss_status->val[0] : GSM0808_LCLS_STS_NA, |
| }, |
| }; |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } else if (ie_lcls_break_req && !ie_lcls_bss_status) { |
| ran_dec_msg = (struct ran_msg){ |
| .msg_type = RAN_MSG_LCLS_BREAK_REQ, |
| .msg_name = "BSSMAP LCLS Notification (LCLS Break Req)", |
| .lcls_break_req = { |
| .todo = 23, |
| }, |
| }; |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| LOG_RAN_A_DEC(ran_dec, LOGL_ERROR, "Ignoring broken LCLS Notification message\n"); |
| return -EINVAL; |
| } |
| |
| static int ran_a_decode_handover_required(struct ran_dec *ran_dec, const struct msgb *msg, const struct tlv_parsed *tp) |
| { |
| const struct tlv_p_entry *ie_cause = TLVP_GET(tp, GSM0808_IE_CAUSE); |
| const struct tlv_p_entry *ie_cil = TLVP_GET(tp, GSM0808_IE_CELL_IDENTIFIER_LIST); |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_HANDOVER_REQUIRED, |
| .msg_name = "BSSMAP Handover Required", |
| }; |
| /* On decoding failures, dispatch an invalid RAN_MSG_HANDOVER_REQUIRED so msc_a can pass down a |
| * BSS_MAP_MSG_HANDOVER_REQUIRED_REJECT message. */ |
| |
| if (ie_cause) |
| ran_dec_msg.handover_required.cause = ie_cause->val[0]; |
| else |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Cause IE missing\n"); |
| |
| if (!ie_cil |
| || gsm0808_dec_cell_id_list2(&ran_dec_msg.handover_required.cil, ie_cil->val, ie_cil->len) <= 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "No or invalid Cell Identifier List IE\n"); |
| ran_dec_msg.handover_required.cil = (struct gsm0808_cell_id_list2){}; |
| } |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static uint8_t a5_encryption_mask_from_gsm0808_chosen_enc_alg(enum gsm0808_chosen_enc_alg val) |
| { |
| return 1 << val; |
| } |
| |
| static int ran_a_decode_handover_request(struct ran_dec *ran_dec, const struct msgb *msg, const struct tlv_parsed *tp) |
| { |
| struct osmo_gsm48_classmark classmark = {}; |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_HANDOVER_REQUEST, |
| .msg_name = "BSSMAP Handover Request", |
| .handover_request = { |
| .classmark = &classmark, |
| }, |
| }; |
| struct ran_handover_request *r = &ran_dec_msg.handover_request; |
| |
| const struct tlv_p_entry *ie_channel_type = TLVP_GET(tp, GSM0808_IE_CHANNEL_TYPE); |
| const struct tlv_p_entry *ie_encryption_information = TLVP_GET(tp, GSM0808_IE_ENCRYPTION_INFORMATION); |
| const struct tlv_p_entry *ie_classmark1 = TLVP_GET(tp, GSM0808_IE_CLASSMARK_INFORMATION_TYPE_1); |
| const struct tlv_p_entry *ie_classmark2 = TLVP_GET(tp, GSM0808_IE_CLASSMARK_INFORMATION_T2); |
| const struct tlv_p_entry *ie_cell_id_serving = TLVP_GET(&tp[0], GSM0808_IE_CELL_IDENTIFIER); |
| const struct tlv_p_entry *ie_cell_id_target = TLVP_GET(&tp[1], GSM0808_IE_CELL_IDENTIFIER); |
| const struct tlv_p_entry *ie_cause = TLVP_GET(tp, GSM0808_IE_CAUSE); |
| const struct tlv_p_entry *ie_classmark3 = TLVP_GET(tp, GSM0808_IE_CLASSMARK_INFORMATION_T3); |
| const struct tlv_p_entry *ie_current_channel_type_1 = TLVP_GET(tp, GSM0808_IE_CURRENT_CHANNEL_TYPE_1); |
| const struct tlv_p_entry *ie_speech_version_used = TLVP_GET(tp, GSM0808_IE_SPEECH_VERSION); |
| const struct tlv_p_entry *ie_chosen_encr_alg_serving = TLVP_GET(tp, GSM0808_IE_CHOSEN_ENCR_ALG); |
| const struct tlv_p_entry *ie_old_bss_to_new_bss_info = TLVP_GET(tp, GSM0808_IE_OLD_BSS_TO_NEW_BSS_INFORMATION); |
| const struct tlv_p_entry *ie_imsi = TLVP_GET(tp, GSM0808_IE_IMSI); |
| const struct tlv_p_entry *ie_aoip_transp_addr = TLVP_GET(tp, GSM0808_IE_AOIP_TRASP_ADDR); |
| const struct tlv_p_entry *ie_codec_list_msc_preferred = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC_LIST); |
| const struct tlv_p_entry *ie_call_id = TLVP_GET(tp, GSM0808_IE_CALL_ID); |
| const struct tlv_p_entry *ie_kc128 = TLVP_GET(tp, GSM0808_IE_KC_128); |
| const struct tlv_p_entry *ie_global_call_ref = TLVP_GET(tp, GSM0808_IE_GLOBAL_CALL_REF); |
| |
| struct gsm0808_channel_type channel_type; |
| struct gsm0808_encrypt_info encr_info; |
| struct gsm0808_speech_codec_list scl; |
| struct geran_encr geran_encr = {}; |
| struct osmo_sockaddr_str rtp_ran_local; |
| |
| if (!ie_channel_type) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Mandatory IE missing: Channel Type\n"); |
| return -EINVAL; |
| } |
| if (gsm0808_dec_channel_type(&channel_type, ie_channel_type->val, ie_channel_type->len) <= 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Failed to decode Channel Type IE\n"); |
| return -EINVAL; |
| } |
| r->geran.channel_type = &channel_type; |
| |
| if (ie_encryption_information) { |
| int i; |
| if (gsm0808_dec_encrypt_info(&encr_info, ie_encryption_information->val, ie_encryption_information->len) |
| <= 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Failed to decode Encryption Information IE\n"); |
| return -EINVAL; |
| } |
| |
| for (i = 0; i < encr_info.perm_algo_len; i++) { |
| r->geran.a5_encryption_mask |= |
| a5_encryption_mask_from_gsm0808_chosen_enc_alg(encr_info.perm_algo[i]); |
| } |
| |
| if (encr_info.key_len > sizeof(geran_encr.key)) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Failed to decode Encryption Information IE:" |
| " encryption key is too long: %u\n", geran_encr.key_len); |
| return -EINVAL; |
| } |
| |
| if (encr_info.key_len) { |
| memcpy(geran_encr.key, encr_info.key, encr_info.key_len); |
| geran_encr.key_len = encr_info.key_len; |
| } |
| |
| if (ie_kc128) { |
| memcpy(geran_encr.kc128, ie_kc128->val, 16); |
| geran_encr.kc128_present = true; |
| } |
| |
| r->geran.chosen_encryption = &geran_encr; |
| } |
| |
| if (!ie_classmark1 && !ie_classmark2) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Mandatory IE missing: either Classmark Information 1" |
| " or Classmark Information 2 must be included\n"); |
| return -EINVAL; |
| } |
| |
| if (ie_classmark1) { |
| if (ie_classmark1->len != sizeof(classmark.classmark1)) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Invalid size for Classmark 1: %u, expected %zu\n", |
| ie_classmark1->len, sizeof(classmark.classmark1)); |
| return -EINVAL; |
| } |
| memcpy((uint8_t*)&classmark.classmark1, ie_classmark1->val, ie_classmark1->len); |
| classmark.classmark1_set = true; |
| } |
| |
| if (ie_classmark2) { |
| uint8_t len = OSMO_MIN(ie_classmark2->len, sizeof(classmark.classmark2)); |
| memcpy((uint8_t*)&classmark.classmark2, ie_classmark2->val, len); |
| classmark.classmark2_len = len; |
| } |
| |
| if (!ie_cell_id_serving) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Mandatory IE missing: Cell Identifier (Serving)\n"); |
| return -EINVAL; |
| } |
| if (gsm0808_dec_cell_id(&r->cell_id_serving, ie_cell_id_serving->val, |
| ie_cell_id_serving->len) <= 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Failed to decode Cell Identifier (Serving) IE\n"); |
| return -EINVAL; |
| } |
| |
| if (!ie_cell_id_target) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Mandatory IE missing: Cell Identifier (Target)\n"); |
| return -EINVAL; |
| } |
| if (gsm0808_dec_cell_id(&r->cell_id_target, ie_cell_id_target->val, |
| ie_cell_id_target->len) <= 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Failed to decode Cell Identifier (Target) IE\n"); |
| return -EINVAL; |
| } |
| |
| if (ie_cause) |
| r->bssap_cause = ie_cause->val[0]; |
| |
| if (ie_classmark3) { |
| uint8_t len = OSMO_MIN(ie_classmark3->len, sizeof(classmark.classmark3)); |
| memcpy(classmark.classmark3, ie_classmark3->val, len); |
| classmark.classmark3_len = len; |
| } |
| |
| if (ie_current_channel_type_1) { |
| r->current_channel_type_1 = ie_current_channel_type_1->val[0]; |
| r->current_channel_type_1_present = true; |
| } |
| |
| if (ie_speech_version_used) { |
| r->speech_version_used = ie_speech_version_used->val[0]; |
| } |
| |
| if (ie_chosen_encr_alg_serving && ie_chosen_encr_alg_serving->len) { |
| geran_encr.alg_id = ie_chosen_encr_alg_serving->val[0]; |
| r->geran.chosen_encryption = &geran_encr; |
| } |
| |
| if (ie_old_bss_to_new_bss_info) { |
| r->old_bss_to_new_bss_info_raw = ie_old_bss_to_new_bss_info->val; |
| r->old_bss_to_new_bss_info_raw_len = ie_old_bss_to_new_bss_info->len; |
| } |
| |
| if (ie_imsi) { |
| struct osmo_mobile_identity mi; |
| if (osmo_mobile_identity_decode(&mi, ie_imsi->val, ie_imsi->len, false) |
| || mi.type != GSM_MI_TYPE_IMSI) |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "IE IMSI: cannot decode IMSI identity\n"); |
| else |
| r->imsi = mi.imsi; |
| } |
| |
| if (ie_aoip_transp_addr) { |
| struct sockaddr_storage rtp_addr; |
| if (gsm0808_dec_aoip_trasp_addr(&rtp_addr, ie_aoip_transp_addr->val, ie_aoip_transp_addr->len) < 0) |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "unable to decode AoIP transport address\n"); |
| else if (osmo_sockaddr_str_from_sockaddr(&rtp_ran_local, &rtp_addr) < 0) |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "unable to decode remote RTP IP address\n"); |
| else |
| r->rtp_ran_local = &rtp_ran_local; |
| } |
| |
| if (ie_codec_list_msc_preferred |
| && gsm0808_dec_speech_codec_list(&scl, ie_codec_list_msc_preferred->val, |
| ie_codec_list_msc_preferred->len) == 0) |
| r->codec_list_msc_preferred = &scl; |
| |
| if (ie_call_id && ie_call_id->len == 4) { |
| r->call_id = osmo_load32le(ie_call_id->val); |
| r->call_id_present = true; |
| } |
| |
| if (ie_global_call_ref) { |
| r->global_call_reference = ie_global_call_ref->val; |
| r->global_call_reference_len = ie_global_call_ref->len; |
| } |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_handover_request_ack(struct ran_dec *ran_dec, const struct msgb *msg, const struct tlv_parsed *tp) |
| { |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_HANDOVER_REQUEST_ACK, |
| .msg_name = "BSSMAP Handover Request Acknowledge", |
| }; |
| const struct tlv_p_entry *ie_l3_info = TLVP_GET(tp, GSM0808_IE_LAYER_3_INFORMATION); |
| const struct tlv_p_entry *ie_aoip_transp_addr = TLVP_GET(tp, GSM0808_IE_AOIP_TRASP_ADDR); |
| const struct tlv_p_entry *ie_speech_codec = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC); |
| const struct tlv_p_entry *ie_chosen_channel = TLVP_GET(tp, GSM0808_IE_CHOSEN_CHANNEL); |
| const struct tlv_p_entry *ie_chosen_encr_alg = TLVP_GET(tp, GSM0808_IE_CHOSEN_ENCR_ALG); |
| const struct tlv_p_entry *ie_chosen_speech_version = TLVP_GET(tp, GSM0808_IE_SPEECH_VERSION); |
| |
| /* On missing mandatory IEs, dispatch an invalid RAN_MSG_HANDOVER_REQUEST_ACK so msc_a can act on the failure. */ |
| |
| if (ie_l3_info) { |
| ran_dec_msg.handover_request_ack.rr_ho_command = ie_l3_info->val; |
| ran_dec_msg.handover_request_ack.rr_ho_command_len = ie_l3_info->len; |
| } |
| |
| if (ie_chosen_channel) { |
| ran_dec_msg.handover_request_ack.chosen_channel_present = true; |
| ran_dec_msg.handover_request_ack.chosen_channel = *ie_chosen_channel->val; |
| } |
| |
| if (ie_chosen_encr_alg) { |
| ran_dec_msg.handover_request_ack.chosen_encr_alg = *ie_chosen_encr_alg->val; |
| if (ran_dec_msg.handover_request_ack.chosen_encr_alg < 1 |
| || ran_dec_msg.handover_request_ack.chosen_encr_alg > 8) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "invalid Chosen Encryption Algorithm: %u\n", |
| ran_dec_msg.handover_request_ack.chosen_encr_alg); |
| } |
| } |
| |
| if (ie_chosen_speech_version) { |
| struct gsm0808_speech_codec sc; |
| ran_dec_msg.handover_request_ack.chosen_speech_version = ie_chosen_speech_version->val[0]; |
| |
| /* the codec may be extrapolated from this Speech Version or below from Speech Codec */ |
| gsm0808_speech_codec_from_chan_type(&sc, ran_dec_msg.handover_request_ack.chosen_speech_version); |
| ran_dec_msg.handover_request_ack.codec_present = true; |
| ran_dec_msg.handover_request_ack.codec = ran_a_mgcp_codec_from_sc(&sc); |
| } |
| |
| if (ie_aoip_transp_addr) { |
| struct sockaddr_storage rtp_addr; |
| if (gsm0808_dec_aoip_trasp_addr(&rtp_addr, ie_aoip_transp_addr->val, ie_aoip_transp_addr->len) < 0) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "unable to decode AoIP transport address\n"); |
| } else if (osmo_sockaddr_str_from_sockaddr(&ran_dec_msg.handover_request_ack.remote_rtp, |
| &rtp_addr)) { |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "unable to decode remote RTP IP address\n"); |
| ran_dec_msg.handover_request_ack.remote_rtp = (struct osmo_sockaddr_str){}; |
| } |
| } |
| |
| if (ie_speech_codec) { |
| struct gsm0808_speech_codec sc; |
| if (gsm0808_dec_speech_codec(&sc, ie_speech_codec->val, ie_speech_codec->len) < 0) |
| LOG_RAN_A_DEC_MSG(LOGL_ERROR, "unable to decode IE Speech Codec (Chosen)\n"); |
| else { |
| /* the codec may be extrapolated from above Speech Version or from this Speech Codec */ |
| ran_dec_msg.handover_request_ack.codec_present = true; |
| ran_dec_msg.handover_request_ack.codec = ran_a_mgcp_codec_from_sc(&sc); |
| } |
| } |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_handover_detect(struct ran_dec *ran_dec, const struct msgb *msg, const struct tlv_parsed *tp) |
| { |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_HANDOVER_DETECT, |
| .msg_name = "BSSMAP Handover Detect", |
| }; |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_handover_succeeded(struct ran_dec *ran_dec, const struct msgb *msg, const struct tlv_parsed *tp) |
| { |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_HANDOVER_SUCCEEDED, |
| .msg_name = "BSSMAP Handover Succeeded", |
| }; |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_handover_complete(struct ran_dec *ran_dec, const struct msgb *msg, const struct tlv_parsed *tp) |
| { |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_HANDOVER_COMPLETE, |
| .msg_name = "BSSMAP Handover Complete", |
| }; |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_handover_failure(struct ran_dec *ran_dec, const struct msgb *msg, const struct tlv_parsed *tp) |
| { |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_HANDOVER_FAILURE, |
| .msg_name = "BSSMAP Handover Failure", |
| }; |
| |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| static int ran_a_decode_bssmap(struct ran_dec *ran_dec, struct msgb *bssmap) |
| { |
| struct tlv_parsed tp[2]; |
| int rc; |
| struct bssmap_header *h = msgb_l2(bssmap); |
| uint8_t msg_type; |
| bssmap->l3h = bssmap->l2h + sizeof(*h); |
| |
| if (msgb_l3len(bssmap) < 1) { |
| LOG_RAN_A_DEC(ran_dec, LOGL_ERROR, "No data received, discarding message\n"); |
| return -1; |
| } |
| |
| if (msgb_l3len(bssmap) < h->length) { |
| LOG_RAN_A_DEC(ran_dec, LOGL_ERROR, "BSSMAP data truncated, discarding message:" |
| " msgb_l3len(bssmap) == %u < bssmap_header->length == %u\n", |
| msgb_l3len(bssmap), h->length); |
| return -1; |
| } |
| |
| if (msgb_l3len(bssmap) > h->length) { |
| LOG_RAN_A_DEC(ran_dec, LOGL_NOTICE, "There are %u extra bytes after the BSSMAP data, truncating:" |
| " msgb_l3len(bssmap) == %u > bssmap_header->length == %u\n", |
| msgb_l3len(bssmap) - h->length, |
| msgb_l3len(bssmap), h->length); |
| msgb_l3trim(bssmap, h->length); |
| } |
| |
| /* h->type == BSSAP_MSG_BSS_MANAGEMENT; h->length is the data length, |
| * which starts with the MAP msg_type, followed by IEs. */ |
| msg_type = bssmap->l3h[0]; |
| rc = osmo_bssap_tlv_parse2(tp, ARRAY_SIZE(tp), bssmap->l3h + 1, h->length - 1); |
| if (rc < 0) { |
| LOG_RAN_A_DEC(ran_dec, LOGL_ERROR, "Failed parsing TLV, discarding message\n"); |
| return -EINVAL; |
| } |
| |
| LOG_RAN_A_DEC(ran_dec, LOGL_DEBUG, "%s\n", gsm0808_bssmap_name(msg_type)); |
| |
| switch (msg_type) { |
| case BSS_MAP_MSG_COMPLETE_LAYER_3: |
| return ran_a_decode_l3_compl(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_CLEAR_RQST: |
| return ran_a_decode_clear_request(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_CLEAR_COMPLETE: |
| return ran_a_decode_clear_complete(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_CLASSMARK_UPDATE: |
| return ran_a_decode_classmark_update(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_CIPHER_MODE_COMPLETE: |
| return ran_a_decode_cipher_mode_complete(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_CIPHER_MODE_REJECT: |
| return ran_a_decode_cipher_mode_reject(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_ASSIGMENT_COMPLETE: |
| rc = ran_a_decode_assignment_complete(ran_dec, bssmap, tp); |
| if (rc < 0) { |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_ASSIGNMENT_FAILURE, |
| .msg_name = "BSSMAP Assignment Complete but failed to decode", |
| .clear_request = { |
| .bssap_cause = GSM0808_CAUSE_EQUIPMENT_FAILURE, |
| }, |
| }; |
| ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| return rc; |
| case BSS_MAP_MSG_ASSIGMENT_FAILURE: |
| return ran_a_decode_assignment_failure(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_SAPI_N_REJECT: |
| return ran_a_decode_sapi_n_reject(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_LCLS_NOTIFICATION: |
| return ran_a_decode_lcls_notification(ran_dec, bssmap, tp); |
| |
| /* From current RAN peer, the Handover origin: */ |
| case BSS_MAP_MSG_HANDOVER_REQUIRED: |
| return ran_a_decode_handover_required(ran_dec, bssmap, tp); |
| |
| /* From current MSC to remote handover target MSC */ |
| case BSS_MAP_MSG_HANDOVER_RQST: |
| return ran_a_decode_handover_request(ran_dec, bssmap, tp); |
| |
| /* From potential new RAN peer, the Handover target: */ |
| case BSS_MAP_MSG_HANDOVER_RQST_ACKNOWLEDGE: |
| return ran_a_decode_handover_request_ack(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_HANDOVER_DETECT: |
| return ran_a_decode_handover_detect(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_HANDOVER_SUCCEEDED: |
| return ran_a_decode_handover_succeeded(ran_dec, bssmap, tp); |
| case BSS_MAP_MSG_HANDOVER_COMPLETE: |
| return ran_a_decode_handover_complete(ran_dec, bssmap, tp); |
| |
| /* From any Handover peer: */ |
| case BSS_MAP_MSG_HANDOVER_FAILURE: |
| return ran_a_decode_handover_failure(ran_dec, bssmap, tp); |
| |
| default: |
| LOG_RAN_A_DEC(ran_dec, LOGL_ERROR, "Unimplemented msg type: %s\n", gsm0808_bssmap_name(msg_type)); |
| return -EINVAL; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static int ran_a_decode_l3(struct ran_dec *ran_dec, struct msgb *l3) |
| { |
| struct dtap_header *dtap = msgb_l2(l3); |
| struct ran_msg ran_dec_msg = { |
| .msg_type = RAN_MSG_DTAP, |
| .msg_name = "BSSAP DTAP", |
| .dtap = l3, |
| }; |
| l3->l3h = l3->l2h + sizeof(struct dtap_header); |
| OMSC_LINKID_CB(l3) = dtap->link_id; |
| return ran_decoded(ran_dec, &ran_dec_msg); |
| } |
| |
| int ran_a_decode_l2(struct ran_dec *ran_dec, struct msgb *bssap) |
| { |
| uint8_t bssap_type; |
| OSMO_ASSERT(bssap); |
| |
| if (!msgb_l2(bssap) || !msgb_l2len(bssap)) { |
| LOG_RAN_A_DEC(ran_dec, LOGL_ERROR, "Cannot decode L2, msg->l2h is unset / empty: %s\n", |
| msgb_hexdump(bssap)); |
| return -EINVAL; |
| } |
| |
| if (msgb_l2len(bssap) < sizeof(struct bssmap_header)) { |
| LOG_RAN_A_DEC(ran_dec, LOGL_ERROR, "The header is too short -- discarding message\n"); |
| return -EINVAL; |
| } |
| |
| bssap_type = bssap->l2h[0]; |
| switch (bssap_type) { |
| case BSSAP_MSG_BSS_MANAGEMENT: |
| return ran_a_decode_bssmap(ran_dec, bssap); |
| case BSSAP_MSG_DTAP: |
| return ran_a_decode_l3(ran_dec, bssap); |
| default: |
| LOG_RAN_A_DEC(ran_dec, LOGL_ERROR, "Unimplemented BSSAP msg type: %s\n", gsm0808_bssap_name(bssap_type)); |
| return -EINVAL; |
| } |
| } |
| |
| static struct msgb *ran_a_wrap_dtap(struct msgb *dtap) |
| { |
| struct msgb *an_apdu; |
| dtap->l3h = dtap->data; |
| an_apdu = gsm0808_create_dtap(dtap, OMSC_LINKID_CB(dtap)); |
| an_apdu->l2h = an_apdu->data; |
| msgb_free(dtap); |
| return an_apdu; |
| } |
| |
| static int ran_a_channel_type_to_speech_codec_list(struct gsm0808_speech_codec_list *scl, const struct gsm0808_channel_type *ct) |
| { |
| unsigned int i; |
| int rc; |
| |
| memset(scl, 0, sizeof(*scl)); |
| for (i = 0; i < ct->perm_spch_len; i++) { |
| rc = gsm0808_speech_codec_from_chan_type(&scl->codec[i], ct->perm_spch[i]); |
| if (rc != 0) |
| return -EINVAL; |
| } |
| scl->len = i; |
| |
| return 0; |
| } |
| |
| static void _gsm0808_assignment_extend_osmux(struct msgb *msg, uint8_t cid) |
| { |
| OSMO_ASSERT(msg->l3h[1] == msgb_l3len(msg) - 2); /*TL not in len */ |
| msgb_tv_put(msg, GSM0808_IE_OSMO_OSMUX_CID, cid); |
| msg->l3h[1] = msgb_l3len(msg) - 2; |
| } |
| |
| /* Compose a BSSAP Assignment Command. |
| * Passing an RTP address is optional. |
| * The msub is passed merely for error logging. */ |
| static struct msgb *ran_a_make_assignment_command(struct osmo_fsm_inst *log_fi, |
| const struct ran_assignment_command *ac) |
| { |
| struct gsm0808_speech_codec_list scl; |
| struct gsm0808_speech_codec_list *use_scl = NULL; |
| struct sockaddr_storage rtp_addr; |
| struct sockaddr_storage *use_rtp_addr = NULL; |
| struct msgb *msg; |
| const uint32_t *call_id = NULL; |
| int rc; |
| |
| if (!ac->channel_type) { |
| LOG_RAN_A_ENC(log_fi, LOGL_ERROR, "Assignment Command: missing Channel Type\n"); |
| return NULL; |
| } |
| |
| if (ac->channel_type->ch_indctr == GSM0808_CHAN_SPEECH) { |
| rc = ran_a_channel_type_to_speech_codec_list(&scl, ac->channel_type); |
| if (rc < 0) { |
| LOG_RAN_A_ENC(log_fi, LOGL_ERROR, "Assignment Command: Cannot translate Channel Type to Speech Codec List\n"); |
| return NULL; |
| } |
| use_scl = &scl; |
| |
| /* Package RTP-Address data */ |
| if (osmo_sockaddr_str_is_nonzero(ac->cn_rtp)) { |
| struct sockaddr_in *sin; |
| struct sockaddr_in6 *sin6; |
| int family = osmo_ip_str_type(ac->cn_rtp->ip); |
| switch (family) { |
| case AF_INET: |
| sin = (struct sockaddr_in *)&rtp_addr; |
| sin->sin_family = AF_INET; |
| sin->sin_port = osmo_htons(ac->cn_rtp->port); |
| if (inet_pton(AF_INET, ac->cn_rtp->ip, &sin->sin_addr) != 1) { |
| LOG_RAN_A_ENC(log_fi, LOGL_ERROR, |
| "Assignment Command: Invalid RTP-Address %s\n", |
| ac->cn_rtp->ip); |
| return NULL; |
| } |
| if (sin->sin_port == 0) { |
| LOG_RAN_A_ENC(log_fi, LOGL_ERROR, |
| "Assignment Command: Invalid RTP-Port\n"); |
| return NULL; |
| } |
| break; |
| case AF_INET6: |
| sin6 = (struct sockaddr_in6 *)&rtp_addr; |
| sin6->sin6_family = AF_INET6; |
| sin6->sin6_port = osmo_htons(ac->cn_rtp->port); |
| if (inet_pton(AF_INET6, ac->cn_rtp->ip, &sin6->sin6_addr) != 1) { |
| LOG_RAN_A_ENC(log_fi, LOGL_ERROR, |
| "Assignment Command: Invalid RTP-Address %s\n", |
| ac->cn_rtp->ip); |
| return NULL; |
| } |
| if (sin6->sin6_port == 0) { |
| LOG_RAN_A_ENC(log_fi, LOGL_ERROR, |
| "Assignment Command: Invalid RTP-Port\n"); |
| return NULL; |
| } |
| break; |
| default: |
| LOG_RAN_A_ENC(log_fi, LOGL_ERROR, |
| "Assignment Command: Invalid RTP-Address type for %s\n", |
| ac->cn_rtp->ip); |
| return NULL; |
| } |
| use_rtp_addr = &rtp_addr; |
| } |
| } |
| |
| if(ac->call_id_present == true) |
| call_id = &ac->call_id; |
| |
| msg = gsm0808_create_ass(ac->channel_type, NULL, use_rtp_addr, use_scl, call_id); |
| if (ac->osmux_present) |
| _gsm0808_assignment_extend_osmux(msg, ac->osmux_cid); |
| return msg; |
| } |
| |
| /* For an A5/N number a5_n set dst to the matching GSM0808_ALG_ID_A5_<n>. */ |
| static int a5_n_to_gsm0808_chosen_enc_alg(uint8_t *dst, int a5_n) |
| { |
| switch (a5_n) { |
| case 0: |
| *dst = GSM0808_ALG_ID_A5_0; |
| return 0; |
| case 1: |
| *dst = GSM0808_ALG_ID_A5_1; |
| return 0; |
| case 2: |
| *dst = GSM0808_ALG_ID_A5_2; |
| return 0; |
| case 3: |
| *dst = GSM0808_ALG_ID_A5_3; |
| return 0; |
| case 4: |
| *dst = GSM0808_ALG_ID_A5_4; |
| return 0; |
| default: |
| return -ENOTSUP; |
| } |
| } |
| |
| static int make_encrypt_info_perm_algo(struct osmo_fsm_inst *fi, struct gsm0808_encrypt_info *ei, |
| uint8_t a5_encryption_mask, const struct osmo_gsm48_classmark *cm) |
| { |
| int i; |
| int j = 0; |
| for (i = 0; i < 8; i++) { |
| int supported; |
| |
| /* A5/n permitted by osmo-msc.cfg? */ |
| if (!(a5_encryption_mask & (1 << i))) |
| continue; |
| |
| /* A5/n supported by MS? */ |
| supported = osmo_gsm48_classmark_supports_a5(cm, i); |
| if (supported != 1) |
| continue; |
| |
| if (a5_n_to_gsm0808_chosen_enc_alg(&ei->perm_algo[j], i)) { |
| LOG_RAN_A_ENC(fi, LOGL_ERROR, "Not supported: A5/%d algorithm\n", i); |
| return -1; |
| } |
| j++; |
| ei->perm_algo_len = j; |
| } |
| return 0; |
| } |
| |
| /* For ran_a_make_cipher_mode_command(), for |
| * memcpy(ei.key, cm->vec->kc, sizeof(cm->vec->kc)); |
| */ |
| osmo_static_assert(sizeof(((struct gsm0808_encrypt_info*)0)->key) >= sizeof(((struct osmo_auth_vector*)0)->kc), |
| gsm0808_encrypt_info_key_fits_osmo_auth_vec_kc); |
| static struct msgb *ran_a_make_cipher_mode_command(struct osmo_fsm_inst *fi, const struct ran_cipher_mode_command *cm) |
| { |
| struct gsm0808_cipher_mode_command cmc = { |
| .cipher_response_mode_present = true, |
| .cipher_response_mode = 1, /* 1: include IMEISV (3GPP TS 48.008 3.2.2.34) */ |
| }; |
| struct gsm0808_encrypt_info *ei = &cmc.ei; |
| char buf[16 * 2 + 1]; |
| |
| if (make_encrypt_info_perm_algo(fi, ei, cm->geran.a5_encryption_mask, cm->classmark)) |
| return NULL; |
| |
| if (ei->perm_algo_len == 0) { |
| LOG_RAN_A_ENC(fi, LOGL_ERROR, "cannot start ciphering, no intersection between MSC-configured" |
| " and MS-supported A5 algorithms. MSC: 0x%02x MS: %s\n", |
| cm->geran.a5_encryption_mask, osmo_gsm48_classmark_a5_name(cm->classmark)); |
| return NULL; |
| } |
| |
| /* In case of UMTS AKA, the Kc for ciphering must be derived from the 3G auth |
| * tokens. vec->kc was calculated from the GSM algorithm and is not |
| * necessarily a match for the UMTS AKA tokens. */ |
| if (cm->geran.umts_aka) { |
| int i; |
| osmo_auth_c3(ei->key, cm->vec->ck, cm->vec->ik); |
| |
| for (i = 0; i < ei->perm_algo_len; i++) { |
| if (ei->perm_algo[i] != GSM0808_ALG_ID_A5_4) |
| continue; |
| /* A5/4 is included, so need to generate Kc128 */ |
| osmo_kdf_kc128(cm->vec->ck, cm->vec->ik, cmc.kc128); |
| cmc.kc128_present = true; |
| break; |
| } |
| } else { |
| memcpy(ei->key, cm->vec->kc, sizeof(cm->vec->kc)); |
| } |
| ei->key_len = sizeof(cm->vec->kc); |
| |
| /* Store chosen GERAN key where the caller asked it to be stored. |
| * alg_id remains unknown until we receive a Cipher Mode Complete from the BSC */ |
| if (cm->geran.chosen_key) { |
| *cm->geran.chosen_key = (struct geran_encr){0}; |
| |
| if (ei->key_len > sizeof(cm->geran.chosen_key->key)) { |
| LOG_RAN_A_ENC(fi, LOGL_ERROR, "Chosen key is larger than I can store\n"); |
| return NULL; |
| } |
| memcpy(cm->geran.chosen_key->key, ei->key, ei->key_len); |
| cm->geran.chosen_key->key_len = ei->key_len; |
| |
| if (cmc.kc128_present) { |
| memcpy(cm->geran.chosen_key->kc128, cmc.kc128, 16); |
| cm->geran.chosen_key->kc128_present = true; |
| } |
| } |
| |
| LOG_RAN_A_ENC(fi, LOGL_DEBUG, "Tx BSSMAP CIPHER MODE COMMAND to BSC, %u ciphers (%s) key %s\n", |
| ei->perm_algo_len, osmo_hexdump_nospc(ei->perm_algo, ei->perm_algo_len), |
| osmo_hexdump_buf(buf, sizeof(buf), ei->key, ei->key_len, NULL, false)); |
| return gsm0808_create_cipher2(&cmc); |
| } |
| |
| struct msgb *ran_a_make_handover_request(struct osmo_fsm_inst *log_fi, const struct ran_handover_request *n) |
| { |
| struct sockaddr_storage ss; |
| struct gsm0808_handover_request r = { |
| .cell_identifier_serving = n->cell_id_serving, |
| .cell_identifier_target = n->cell_id_target, |
| .cause = n->bssap_cause, |
| .current_channel_type_1_present = n->current_channel_type_1_present, |
| .current_channel_type_1 = n->current_channel_type_1, |
| |
| .speech_version_used = n->speech_version_used, |
| |
| .old_bss_to_new_bss_info_raw = n->old_bss_to_new_bss_info_raw, |
| .old_bss_to_new_bss_info_raw_len = n->old_bss_to_new_bss_info_raw_len, |
| |
| .imsi = n->imsi, |
| .codec_list_msc_preferred = n->codec_list_msc_preferred, |
| .call_id_present = n->call_id_present, |
| .call_id = n->call_id, |
| .global_call_reference = n->global_call_reference, |
| .global_call_reference_len = n->global_call_reference_len, |
| }; |
| |
| if (!n->geran.channel_type) { |
| LOG_RAN_A_ENC(log_fi, LOGL_ERROR, "Channel Type required for encoding Handover Request in BSSAP\n"); |
| return NULL; |
| } |
| r.channel_type = *n->geran.channel_type; |
| |
| /* Encryption Information */ |
| make_encrypt_info_perm_algo(log_fi, &r.encryption_information, n->geran.a5_encryption_mask, n->classmark); |
| if (n->geran.chosen_encryption && n->geran.chosen_encryption->key_len) { |
| /* Prevent both source / destination buffer overrun / overflow */ |
| if (n->geran.chosen_encryption->key_len > sizeof(r.encryption_information.key) |
| || n->geran.chosen_encryption->key_len > sizeof(n->geran.chosen_encryption->key)) { |
| LOG_RAN_A_ENC(log_fi, LOGL_ERROR, "Handover Request: invalid chosen encryption key size %u\n", |
| n->geran.chosen_encryption->key_len); |
| return NULL; |
| } |
| memcpy(r.encryption_information.key, |
| n->geran.chosen_encryption->key, n->geran.chosen_encryption->key_len); |
| r.encryption_information.key_len = n->geran.chosen_encryption->key_len; |
| r.chosen_encryption_algorithm_serving = n->geran.chosen_encryption->alg_id; |
| |
| if (n->geran.chosen_encryption->kc128_present) { |
| r.more_items = true; |
| memcpy(r.kc128, n->geran.chosen_encryption->kc128, sizeof(r.kc128)); |
| r.kc128_present = true; |
| } |
| } |
| |
| if (n->classmark) |
| r.classmark_information = *n->classmark; |
| |
| if (osmo_sockaddr_str_is_nonzero(n->rtp_ran_local)) { |
| if (osmo_sockaddr_str_to_sockaddr(n->rtp_ran_local, &ss)) { |
| LOG_RAN_A_ENC(log_fi, LOGL_ERROR, |
| "Handover Request: invalid AoIP Transport Layer address/port: " |
| OSMO_SOCKADDR_STR_FMT "\n", OSMO_SOCKADDR_STR_FMT_ARGS(n->rtp_ran_local)); |
| return NULL; |
| } |
| r.aoip_transport_layer = &ss; |
| } |
| |
| return gsm0808_create_handover_request(&r); |
| } |
| |
| static struct msgb *ran_a_make_handover_request_ack(struct osmo_fsm_inst *caller_fi, const struct ran_handover_request_ack *r) |
| { |
| struct sockaddr_storage ss; |
| struct gsm0808_handover_request_ack params = { |
| .l3_info = r->rr_ho_command, |
| .l3_info_len = r->rr_ho_command_len, |
| .chosen_channel_present = r->chosen_channel_present, |
| .chosen_channel = r->chosen_channel, |
| .chosen_encr_alg = r->chosen_encr_alg, |
| .chosen_speech_version = r->chosen_speech_version, |
| }; |
| |
| if (osmo_sockaddr_str_is_nonzero(&r->remote_rtp)) { |
| osmo_sockaddr_str_to_sockaddr(&r->remote_rtp, &ss); |
| params.aoip_transport_layer = &ss; |
| } |
| |
| return gsm0808_create_handover_request_ack2(¶ms); |
| } |
| |
| struct msgb *ran_a_make_handover_command(struct osmo_fsm_inst *log_fi, const struct ran_handover_command *n) |
| { |
| struct gsm0808_handover_command c = { |
| .l3_info = n->rr_ho_command, |
| .l3_info_len = n->rr_ho_command_len, |
| }; |
| |
| return gsm0808_create_handover_command(&c); |
| } |
| |
| struct msgb *ran_a_make_handover_failure(struct osmo_fsm_inst *log_fi, const struct ran_msg *msg) |
| { |
| struct gsm0808_handover_failure params = { |
| .cause = msg->handover_failure.cause, |
| }; |
| return gsm0808_create_handover_failure(¶ms); |
| } |
| |
| static struct msgb *_ran_a_encode(struct osmo_fsm_inst *caller_fi, const struct ran_msg *ran_enc_msg) |
| { |
| |
| LOG_RAN_A_ENC(caller_fi, LOGL_DEBUG, "%s\n", ran_msg_type_name(ran_enc_msg->msg_type)); |
| |
| switch (ran_enc_msg->msg_type) { |
| |
| case RAN_MSG_DTAP: |
| return ran_a_wrap_dtap(ran_enc_msg->dtap); |
| |
| case RAN_MSG_CLASSMARK_REQUEST: |
| return gsm0808_create_classmark_request(); |
| |
| case RAN_MSG_CLEAR_COMMAND: |
| return gsm0808_create_clear_command2(ran_enc_msg->clear_command.gsm0808_cause, |
| ran_enc_msg->clear_command.csfb_ind); |
| |
| case RAN_MSG_ASSIGNMENT_COMMAND: |
| return ran_a_make_assignment_command(caller_fi, &ran_enc_msg->assignment_command); |
| |
| case RAN_MSG_COMMON_ID: |
| return gsm0808_create_common_id(ran_enc_msg->common_id.imsi, NULL, |
| ran_enc_msg->common_id.last_eutran_plmn_present ? |
| &ran_enc_msg->common_id.last_eutran_plmn : |
| NULL |
| ); |
| |
| case RAN_MSG_CIPHER_MODE_COMMAND: |
| return ran_a_make_cipher_mode_command(caller_fi, &ran_enc_msg->cipher_mode_command); |
| |
| case RAN_MSG_HANDOVER_REQUIRED_REJECT: |
| return gsm0808_create_handover_required_reject(&ran_enc_msg->handover_required_reject); |
| |
| case RAN_MSG_HANDOVER_REQUEST: |
| return ran_a_make_handover_request(caller_fi, &ran_enc_msg->handover_request); |
| |
| case RAN_MSG_HANDOVER_REQUEST_ACK: |
| return ran_a_make_handover_request_ack(caller_fi, &ran_enc_msg->handover_request_ack); |
| |
| case RAN_MSG_HANDOVER_COMMAND: |
| return ran_a_make_handover_command(caller_fi, &ran_enc_msg->handover_command); |
| |
| case RAN_MSG_HANDOVER_SUCCEEDED: |
| return gsm0808_create_handover_succeeded(); |
| |
| case RAN_MSG_HANDOVER_FAILURE: |
| return ran_a_make_handover_failure(caller_fi, ran_enc_msg); |
| |
| default: |
| LOG_RAN_A_ENC(caller_fi, LOGL_ERROR, "Unimplemented RAN-encode message type: %s\n", |
| ran_msg_type_name(ran_enc_msg->msg_type)); |
| return NULL; |
| } |
| } |
| |
| struct msgb *ran_a_encode(struct osmo_fsm_inst *caller_fi, const struct ran_msg *ran_enc_msg) |
| { |
| struct msgb *msg = _ran_a_encode(caller_fi, ran_enc_msg); |
| |
| if (!msg) |
| return NULL; |
| |
| msg->l2h = msg->data; |
| |
| /* some consistency checks to ensure we don't send invalid length */ |
| switch (msg->l2h[0]) { |
| case BSSAP_MSG_DTAP: |
| OSMO_ASSERT(msgb_l2len(msg) == msg->l2h[2] + 3); |
| break; |
| case BSSAP_MSG_BSS_MANAGEMENT: |
| OSMO_ASSERT(msgb_l2len(msg) == msg->l2h[1] + 2); |
| break; |
| default: |
| break; |
| } |
| |
| return msg; |
| } |
| |
| static void cl_parse_osmux(struct osmo_fsm_inst *log_fi, struct msgb *msg, int *supports_osmux) |
| { |
| struct tlv_parsed tp; |
| int rc; |
| |
| if (supports_osmux == NULL) |
| return; |
| |
| rc = tlv_parse(&tp, gsm0808_att_tlvdef(), msgb_l3(msg) + 1, msgb_l3len(msg) - 1, 0, 0); |
| if (rc < 0) { |
| LOGPFSMSL(log_fi, DBSSAP, LOGL_ERROR, "BSSMAP: Failed parsing TLV looking for Osmux support\n"); |
| return; |
| } |
| |
| if (TLVP_PRESENT(&tp, GSM0808_IE_OSMO_OSMUX_SUPPORT)) { |
| *supports_osmux = true; |
| } else { |
| *supports_osmux = false; |
| } |
| } |
| |
| /* Return 1 for a RESET, 2 for a RESET ACK message, 0 otherwise. |
| * In supports_osmux, return 0 for no information, 1 for support detected, -1 for non-support detected. */ |
| enum reset_msg_type bssmap_is_reset_msg(const struct sccp_ran_inst *sri, struct osmo_fsm_inst *log_fi, |
| struct msgb *l2, int *supports_osmux) |
| { |
| struct bssmap_header *bs = (struct bssmap_header *)msgb_l2(l2); |
| |
| if (supports_osmux != NULL) |
| *supports_osmux = 0; |
| |
| if (!bs |
| || msgb_l2len(l2) < (sizeof(*bs) + 1) |
| || bs->type != BSSAP_MSG_BSS_MANAGEMENT) |
| return SCCP_RAN_MSG_NON_RESET; |
| |
| l2->l3h = l2->l2h + sizeof(struct bssmap_header); |
| |
| switch (l2->l3h[0]) { |
| case BSS_MAP_MSG_RESET: |
| cl_parse_osmux(log_fi, l2, supports_osmux); |
| return SCCP_RAN_MSG_RESET; |
| case BSS_MAP_MSG_RESET_ACKNOWLEDGE: |
| cl_parse_osmux(log_fi, l2, supports_osmux); |
| return SCCP_RAN_MSG_RESET_ACK; |
| default: |
| return SCCP_RAN_MSG_NON_RESET; |
| } |
| } |
| |
| /* Patch regular BSSMAP RESET to add extra T to announce Osmux support (osmocom extension) */ |
| static void _gsm0808_extend_announce_osmux(struct msgb *msg) |
| { |
| OSMO_ASSERT(msg->l3h[1] == msgb_l3len(msg) - 2); /*TL not in len */ |
| msgb_put_u8(msg, GSM0808_IE_OSMO_OSMUX_SUPPORT); |
| msg->l3h[1] = msgb_l3len(msg) - 2; |
| } |
| |
| struct msgb *bssmap_make_reset_msg(const struct sccp_ran_inst *sri, enum reset_msg_type type) |
| { |
| struct gsm_network *net = sri->user_data; |
| struct msgb *msg; |
| |
| switch (type) { |
| case SCCP_RAN_MSG_RESET: |
| msg = gsm0808_create_reset(); |
| break; |
| case SCCP_RAN_MSG_RESET_ACK: |
| msg = gsm0808_create_reset_ack(); |
| break; |
| default: |
| return NULL; |
| } |
| |
| if (!msg) |
| return NULL; |
| |
| if (net->use_osmux != OSMUX_USAGE_OFF) |
| _gsm0808_extend_announce_osmux(msg); |
| |
| return msg; |
| } |
| |
| struct msgb *bssmap_make_paging_msg(const struct sccp_ran_inst *sri, const struct gsm0808_cell_id *page_cell_id, |
| const char *imsi, uint32_t tmsi, enum paging_cause cause) |
| { |
| struct gsm0808_cell_id_list2 cil; |
| gsm0808_cell_id_to_list(&cil, page_cell_id); |
| return gsm0808_create_paging2(imsi, tmsi == GSM_RESERVED_TMSI ? NULL : &tmsi, &cil, NULL); |
| } |
| |
| const char *bssmap_msg_name(const struct sccp_ran_inst *sri, const struct msgb *l2) |
| { |
| struct bssmap_header *bs; |
| |
| if (!l2->l2h) |
| return "?"; |
| |
| bs = (struct bssmap_header *)msgb_l2(l2); |
| switch (bs->type) { |
| case BSSAP_MSG_BSS_MANAGEMENT: |
| return gsm0808_bssmap_name(l2->l2h[0]); |
| case BSSAP_MSG_DTAP: |
| return "DTAP"; |
| default: |
| return "?"; |
| } |
| } |