| /* Common bits for RAN message handling */ |
| /* |
| * (C) 2019 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| * All Rights Reserved |
| * |
| * Author: Neels Hofmeyr |
| * |
| * SPDX-License-Identifier: AGPL-3.0+ |
| * |
| * 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. |
| */ |
| |
| #include <osmocom/core/utils.h> |
| |
| #include <osmocom/msc/ran_msg.h> |
| |
| const struct value_string ran_msg_type_names[] = { |
| { RAN_MSG_NONE, "NONE" }, |
| { RAN_MSG_COMPL_L3, "COMPL_L3" }, |
| { RAN_MSG_DTAP, "DTAP" }, |
| { RAN_MSG_CLEAR_COMMAND, "CLEAR_COMMAND" }, |
| { RAN_MSG_CLEAR_REQUEST, "CLEAR_REQUEST" }, |
| { RAN_MSG_CLEAR_COMPLETE, "CLEAR_COMPLETE" }, |
| { RAN_MSG_CLASSMARK_REQUEST, "CLASSMARK_REQUEST" }, |
| { RAN_MSG_CLASSMARK_UPDATE, "CLASSMARK_UPDATE" }, |
| { RAN_MSG_CIPHER_MODE_COMMAND, "CIPHER_MODE_COMMAND" }, |
| { RAN_MSG_CIPHER_MODE_COMPLETE, "CIPHER_MODE_COMPLETE" }, |
| { RAN_MSG_CIPHER_MODE_REJECT, "CIPHER_MODE_REJECT" }, |
| { RAN_MSG_COMMON_ID, "COMMON_ID" }, |
| { RAN_MSG_ASSIGNMENT_COMMAND, "ASSIGNMENT_COMMAND" }, |
| { RAN_MSG_ASSIGNMENT_COMPLETE, "ASSIGNMENT_COMPLETE" }, |
| { RAN_MSG_ASSIGNMENT_FAILURE, "ASSIGNMENT_FAILURE" }, |
| { RAN_MSG_SAPI_N_REJECT, "SAPI_N_REJECT" }, |
| { RAN_MSG_LCLS_STATUS, "LCLS_STATUS" }, |
| { RAN_MSG_LCLS_BREAK_REQ, "LCLS_BREAK_REQ" }, |
| { RAN_MSG_HANDOVER_COMMAND, "HANDOVER_COMMAND" }, |
| { RAN_MSG_HANDOVER_SUCCEEDED, "HANDOVER_SUCCEEDED" }, |
| { RAN_MSG_HANDOVER_PERFORMED, "HANDOVER_PERFORMED" }, |
| { RAN_MSG_HANDOVER_REQUIRED, "HANDOVER_REQUIRED" }, |
| { RAN_MSG_HANDOVER_REQUIRED_REJECT, "HANDOVER_REQUIRED_REJECT" }, |
| { RAN_MSG_HANDOVER_REQUEST, "HANDOVER_REQUEST" }, |
| { RAN_MSG_HANDOVER_REQUEST_ACK, "HANDOVER_REQUEST_ACK" }, |
| { RAN_MSG_HANDOVER_DETECT, "HANDOVER_DETECT" }, |
| { RAN_MSG_HANDOVER_COMPLETE, "HANDOVER_COMPLETE" }, |
| { RAN_MSG_HANDOVER_FAILURE, "HANDOVER_FAILURE" }, |
| { RAN_MSG_VGCS_VBS_SETUP, "VGCS_VBS_SETUP" }, |
| { RAN_MSG_VGCS_VBS_SETUP_ACK, "VGCS_VBS_SETUP_ACK" }, |
| { RAN_MSG_VGCS_VBS_SETUP_REFUSE, "VGCS_VBS_SETUP_REFUSE" }, |
| { RAN_MSG_VGCS_VBS_ASSIGN_REQ, "VGCS_VBS_ASSIGN_REQ" }, |
| { RAN_MSG_VGCS_VBS_ASSIGN_RES, "VGCS_VBS_ASSIGN_RES" }, |
| { RAN_MSG_VGCS_VBS_ASSIGN_FAIL, "VGCS_VBS_ASSIGN_FAIL" }, |
| { RAN_MSG_VGCS_VBS_QUEUING_IND, "VGCS_VBS_QUEUING_IND" }, |
| { RAN_MSG_UPLINK_REQUEST, "UPLINK_REQUEST" }, |
| { RAN_MSG_UPLINK_REQUEST_ACK, "UPLINK_REQUEST_ACK" }, |
| { RAN_MSG_UPLINK_REQUEST_CNF, "UPLINK_REQUEST_CNF" }, |
| { RAN_MSG_UPLINK_APPLICATION_DATA, "UPLINK_APPLICATION_DATA" }, |
| { RAN_MSG_UPLINK_RELEASE_IND, "UPLINK_RELEASE_IND" }, |
| { RAN_MSG_UPLINK_REJECT_CMD, "UPLINK_REJECT_CMD" }, |
| { RAN_MSG_UPLINK_RELEASE_CMD, "UPLINK_RELEASE_CMD" }, |
| { RAN_MSG_UPLINK_SEIZED_CMD, "UPLINK_SEIZED_CMD" }, |
| { RAN_MSG_VGCS_ADDITIONAL_INFO, "VGCS_ADDITIONAL_INFO" }, |
| { RAN_MSG_VGCS_VBS_AREA_CELL_INFO, "VGCS_VBS_AREA_CELL_INFO" }, |
| { RAN_MSG_VGCS_VBS_ASSIGN_STATUS, "VGCS_VBS_ASSIGN_STATUS" }, |
| { RAN_MSG_VGCS_SMS, "VGCS_SMS" }, |
| {} |
| }; |
| |
| /* extract the N(SD) and return the modulo value for a R99 message */ |
| static uint8_t ran_dec_dtap_undup_determine_nsd_ret_modulo_r99(uint8_t pdisc, uint8_t msg_type, uint8_t *n_sd) |
| { |
| switch (pdisc) { |
| case GSM48_PDISC_MM: |
| case GSM48_PDISC_CC: |
| case GSM48_PDISC_NC_SS: |
| *n_sd = (msg_type >> 6) & 0x3; |
| return 4; |
| case GSM48_PDISC_GROUP_CC: |
| case GSM48_PDISC_BCAST_CC: |
| case GSM48_PDISC_LOC: |
| *n_sd = (msg_type >> 6) & 0x1; |
| return 2; |
| default: |
| /* no sequence number, we cannot detect dups */ |
| return 0; |
| } |
| } |
| |
| /* extract the N(SD) and return the modulo value for a R98 message */ |
| static uint8_t gsm0407_determine_nsd_ret_modulo_r98(uint8_t pdisc, uint8_t msg_type, uint8_t *n_sd) |
| { |
| switch (pdisc) { |
| case GSM48_PDISC_MM: |
| case GSM48_PDISC_CC: |
| case GSM48_PDISC_NC_SS: |
| case GSM48_PDISC_GROUP_CC: |
| case GSM48_PDISC_BCAST_CC: |
| case GSM48_PDISC_LOC: |
| *n_sd = (msg_type >> 6) & 0x1; |
| return 2; |
| default: |
| /* no sequence number, we cannot detect dups */ |
| return 0; |
| } |
| } |
| |
| /* TS 24.007 11.2.3.2.3 Message Type Octet / Duplicate Detection. |
| * (Not static for unit testing). */ |
| int ran_dec_dtap_undup_pdisc_ctr_bin(uint8_t pdisc) |
| { |
| switch (pdisc) { |
| case GSM48_PDISC_MM: |
| case GSM48_PDISC_CC: |
| case GSM48_PDISC_NC_SS: |
| return 0; |
| case GSM48_PDISC_GROUP_CC: |
| return 1; |
| case GSM48_PDISC_BCAST_CC: |
| return 2; |
| case GSM48_PDISC_LOC: |
| return 3; |
| default: |
| return -1; |
| } |
| } |
| |
| /* TS 24.007 11.2.3.2 Message Type Octet / Duplicate Detection */ |
| bool ran_dec_dtap_undup_is_duplicate(struct osmo_fsm_inst *log_fi, uint8_t *n_sd_next, bool is_r99, struct msgb *l3) |
| { |
| struct gsm48_hdr *gh; |
| uint8_t pdisc; |
| uint8_t n_sd, modulo; |
| int bin; |
| |
| gh = msgb_l3(l3); |
| pdisc = gsm48_hdr_pdisc(gh); |
| |
| if (is_r99) { |
| modulo = ran_dec_dtap_undup_determine_nsd_ret_modulo_r99(pdisc, gh->msg_type, &n_sd); |
| } else { /* pre R99 */ |
| modulo = gsm0407_determine_nsd_ret_modulo_r98(pdisc, gh->msg_type, &n_sd); |
| } |
| if (modulo == 0) |
| return false; |
| bin = ran_dec_dtap_undup_pdisc_ctr_bin(pdisc); |
| if (bin < 0) |
| return false; |
| |
| OSMO_ASSERT(bin >= 0 && bin < 4); |
| if (n_sd != n_sd_next[bin]) { |
| /* not what we expected: duplicate */ |
| LOGPFSML(log_fi, LOGL_NOTICE, "Duplicate DTAP: bin=%d, expected n_sd == %u, got %u\n", |
| bin, n_sd_next[bin], n_sd); |
| return true; |
| } else { |
| /* as expected: no dup; update expected counter for next message */ |
| n_sd_next[bin] = (n_sd + 1) % modulo; |
| return false; |
| } |
| } |
| |
| /* convenience: RAN decode implementations can call this to dispatch the decode_cb with a decoded ran_msg. */ |
| int ran_decoded(struct ran_dec *ran_dec, struct ran_msg *ran_msg) |
| { |
| if (!ran_dec->decode_cb) |
| return -1; |
| return ran_dec->decode_cb(ran_dec->caller_fi, ran_dec->caller_data, ran_msg); |
| } |