/* Common bits for RAN message handling */ /* * (C) 2019 by sysmocom - s.f.m.c. GmbH * 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 #include 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); }