diff options
Diffstat (limited to 'openbsc/src/libcommon/gsm_04_08_utils.c')
| -rw-r--r-- | openbsc/src/libcommon/gsm_04_08_utils.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/openbsc/src/libcommon/gsm_04_08_utils.c b/openbsc/src/libcommon/gsm_04_08_utils.c new file mode 100644 index 000000000..1c124629b --- /dev/null +++ b/openbsc/src/libcommon/gsm_04_08_utils.c @@ -0,0 +1,262 @@ +/* GSM Mobile Radio Interface Layer 3 messages on the A-bis interface + * 3GPP TS 04.08 version 7.21.0 Release 1998 / ETSI TS 100 940 V7.21.0 + * utility functions + */ + +/* (C) 2008-2009 by Harald Welte <laforge@gnumonks.org> + * (C) 2008, 2009 by Holger Hans Peter Freyther <zecke@selfish.org> + * + * 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 <http://www.gnu.org/licenses/>. + * + */ +#include <stdio.h> +#include <stdlib.h> +#include <errno.h> +#include <netinet/in.h> + +#include <osmocom/core/msgb.h> +#include <osmocom/gsm/gsm48.h> + +#include <openbsc/abis_rsl.h> +#include <openbsc/debug.h> +#include <openbsc/gsm_04_08.h> +#include <openbsc/transaction.h> +#include <openbsc/paging.h> +#include <openbsc/signal.h> + +/* should ip.access BTS use direct RTP streams between each other (1), + * or should OpenBSC always act as RTP relay/proxy in between (0) ? */ +int ipacc_rtp_direct = 1; + +/* Section 9.1.8 / Table 9.9 */ +struct chreq { + uint8_t val; + uint8_t mask; + enum chreq_type type; +}; + +/* If SYSTEM INFORMATION TYPE 4 NECI bit == 1 */ +static const struct chreq chreq_type_neci1[] = { + { 0xa0, 0xe0, CHREQ_T_EMERG_CALL }, + { 0xc0, 0xe0, CHREQ_T_CALL_REEST_TCH_F }, + { 0x68, 0xfc, CHREQ_T_CALL_REEST_TCH_H }, + { 0x6c, 0xfc, CHREQ_T_CALL_REEST_TCH_H_DBL }, + { 0xe0, 0xe0, CHREQ_T_TCH_F }, + { 0x40, 0xf0, CHREQ_T_VOICE_CALL_TCH_H }, + { 0x50, 0xf0, CHREQ_T_DATA_CALL_TCH_H }, + { 0x00, 0xf0, CHREQ_T_LOCATION_UPD }, + { 0x10, 0xf0, CHREQ_T_SDCCH }, + { 0x80, 0xe0, CHREQ_T_PAG_R_ANY_NECI1 }, + { 0x20, 0xf0, CHREQ_T_PAG_R_TCH_F }, + { 0x30, 0xf0, CHREQ_T_PAG_R_TCH_FH }, + { 0x67, 0xff, CHREQ_T_LMU }, + { 0x60, 0xf9, CHREQ_T_RESERVED_SDCCH }, + { 0x61, 0xfb, CHREQ_T_RESERVED_SDCCH }, + { 0x63, 0xff, CHREQ_T_RESERVED_SDCCH }, + { 0x7f, 0xff, CHREQ_T_RESERVED_IGNORE }, +}; + +/* If SYSTEM INFORMATION TYPE 4 NECI bit == 0 */ +static const struct chreq chreq_type_neci0[] = { + { 0xa0, 0xe0, CHREQ_T_EMERG_CALL }, + { 0xc0, 0xe0, CHREQ_T_CALL_REEST_TCH_H }, + { 0xe0, 0xe0, CHREQ_T_TCH_F }, + { 0x50, 0xf0, CHREQ_T_DATA_CALL_TCH_H }, + { 0x00, 0xe0, CHREQ_T_LOCATION_UPD }, + { 0x80, 0xe0, CHREQ_T_PAG_R_ANY_NECI0 }, + { 0x20, 0xf0, CHREQ_T_PAG_R_TCH_F }, + { 0x30, 0xf0, CHREQ_T_PAG_R_TCH_FH }, + { 0x67, 0xff, CHREQ_T_LMU }, + { 0x60, 0xf9, CHREQ_T_RESERVED_SDCCH }, + { 0x61, 0xfb, CHREQ_T_RESERVED_SDCCH }, + { 0x63, 0xff, CHREQ_T_RESERVED_SDCCH }, + { 0x7f, 0xff, CHREQ_T_RESERVED_IGNORE }, +}; + +static const enum gsm_chan_t ctype_by_chreq[] = { + [CHREQ_T_EMERG_CALL] = GSM_LCHAN_TCH_F, + [CHREQ_T_CALL_REEST_TCH_F] = GSM_LCHAN_TCH_F, + [CHREQ_T_CALL_REEST_TCH_H] = GSM_LCHAN_TCH_H, + [CHREQ_T_CALL_REEST_TCH_H_DBL] = GSM_LCHAN_TCH_H, + [CHREQ_T_SDCCH] = GSM_LCHAN_SDCCH, + [CHREQ_T_TCH_F] = GSM_LCHAN_TCH_F, + [CHREQ_T_VOICE_CALL_TCH_H] = GSM_LCHAN_TCH_H, + [CHREQ_T_DATA_CALL_TCH_H] = GSM_LCHAN_TCH_H, + [CHREQ_T_LOCATION_UPD] = GSM_LCHAN_SDCCH, + [CHREQ_T_PAG_R_ANY_NECI1] = GSM_LCHAN_SDCCH, + [CHREQ_T_PAG_R_ANY_NECI0] = GSM_LCHAN_SDCCH, + [CHREQ_T_PAG_R_TCH_F] = GSM_LCHAN_TCH_F, + [CHREQ_T_PAG_R_TCH_FH] = GSM_LCHAN_TCH_F, + [CHREQ_T_LMU] = GSM_LCHAN_SDCCH, + [CHREQ_T_RESERVED_SDCCH] = GSM_LCHAN_SDCCH, + [CHREQ_T_RESERVED_IGNORE] = GSM_LCHAN_UNKNOWN, +}; + +static const enum gsm_chreq_reason_t reason_by_chreq[] = { + [CHREQ_T_EMERG_CALL] = GSM_CHREQ_REASON_EMERG, + [CHREQ_T_CALL_REEST_TCH_F] = GSM_CHREQ_REASON_CALL, + [CHREQ_T_CALL_REEST_TCH_H] = GSM_CHREQ_REASON_CALL, + [CHREQ_T_CALL_REEST_TCH_H_DBL] = GSM_CHREQ_REASON_CALL, + [CHREQ_T_SDCCH] = GSM_CHREQ_REASON_OTHER, + [CHREQ_T_TCH_F] = GSM_CHREQ_REASON_OTHER, + [CHREQ_T_VOICE_CALL_TCH_H] = GSM_CHREQ_REASON_CALL, + [CHREQ_T_DATA_CALL_TCH_H] = GSM_CHREQ_REASON_OTHER, + [CHREQ_T_LOCATION_UPD] = GSM_CHREQ_REASON_LOCATION_UPD, + [CHREQ_T_PAG_R_ANY_NECI1] = GSM_CHREQ_REASON_PAG, + [CHREQ_T_PAG_R_ANY_NECI0] = GSM_CHREQ_REASON_PAG, + [CHREQ_T_PAG_R_TCH_F] = GSM_CHREQ_REASON_PAG, + [CHREQ_T_PAG_R_TCH_FH] = GSM_CHREQ_REASON_PAG, + [CHREQ_T_LMU] = GSM_CHREQ_REASON_OTHER, + [CHREQ_T_RESERVED_SDCCH] = GSM_CHREQ_REASON_OTHER, + [CHREQ_T_RESERVED_IGNORE] = GSM_CHREQ_REASON_OTHER, +}; + +/* verify that the two tables match */ +osmo_static_assert(sizeof(ctype_by_chreq) == + sizeof(((struct gsm_network *) NULL)->ctype_by_chreq), assert_size); + +/* + * Update channel types for request based on policy. E.g. in the + * case of a TCH/H network/bsc use TCH/H for the emergency calls, + * for early assignment assign a SDCCH and some other options. + */ +void gsm_net_update_ctype(struct gsm_network *network) +{ + /* copy over the data */ + memcpy(network->ctype_by_chreq, ctype_by_chreq, sizeof(ctype_by_chreq)); + + /* + * Use TCH/H for emergency calls when this cell allows TCH/H. Maybe it + * is better to iterate over the BTS/TRX and check if no TCH/F is available + * and then set it to TCH/H. + */ + if (network->neci) + network->ctype_by_chreq[CHREQ_T_EMERG_CALL] = GSM_LCHAN_TCH_H; + + if (network->pag_any_tch) { + if (network->neci) { + network->ctype_by_chreq[CHREQ_T_PAG_R_ANY_NECI0] = GSM_LCHAN_TCH_H; + network->ctype_by_chreq[CHREQ_T_PAG_R_ANY_NECI1] = GSM_LCHAN_TCH_H; + } else { + network->ctype_by_chreq[CHREQ_T_PAG_R_ANY_NECI0] = GSM_LCHAN_TCH_F; + network->ctype_by_chreq[CHREQ_T_PAG_R_ANY_NECI1] = GSM_LCHAN_TCH_F; + } + } +} + +enum gsm_chan_t get_ctype_by_chreq(struct gsm_network *network, uint8_t ra) +{ + int i; + int length; + const struct chreq *chreq; + + if (network->neci) { + chreq = chreq_type_neci1; + length = ARRAY_SIZE(chreq_type_neci1); + } else { + chreq = chreq_type_neci0; + length = ARRAY_SIZE(chreq_type_neci0); + } + + + for (i = 0; i < length; i++) { + const struct chreq *chr = &chreq[i]; + if ((ra & chr->mask) == chr->val) + return network->ctype_by_chreq[chr->type]; + } + LOGP(DRR, LOGL_ERROR, "Unknown CHANNEL REQUEST RQD 0x%02x\n", ra); + return GSM_LCHAN_SDCCH; +} + +int get_reason_by_chreq(uint8_t ra, int neci) +{ + int i; + int length; + const struct chreq *chreq; + + if (neci) { + chreq = chreq_type_neci1; + length = ARRAY_SIZE(chreq_type_neci1); + } else { + chreq = chreq_type_neci0; + length = ARRAY_SIZE(chreq_type_neci0); + } + + for (i = 0; i < length; i++) { + const struct chreq *chr = &chreq[i]; + if ((ra & chr->mask) == chr->val) + return reason_by_chreq[chr->type]; + } + LOGP(DRR, LOGL_ERROR, "Unknown CHANNEL REQUEST REASON 0x%02x\n", ra); + return GSM_CHREQ_REASON_OTHER; +} + +int gsm48_extract_mi(uint8_t *classmark2_lv, int length, char *mi_string, uint8_t *mi_type) +{ + /* Check the size for the classmark */ + if (length < 1 + *classmark2_lv) + return -1; + + uint8_t *mi_lv = classmark2_lv + *classmark2_lv + 1; + if (length < 2 + *classmark2_lv + mi_lv[0]) + return -2; + + *mi_type = mi_lv[1] & GSM_MI_TYPE_MASK; + return gsm48_mi_to_string(mi_string, GSM48_MI_SIZE, mi_lv+1, *mi_lv); +} + +int gsm48_paging_extract_mi(struct gsm48_pag_resp *resp, int length, + char *mi_string, uint8_t *mi_type) +{ + static const uint32_t classmark_offset = + offsetof(struct gsm48_pag_resp, classmark2); + uint8_t *classmark2_lv = (uint8_t *) &resp->classmark2; + return gsm48_extract_mi(classmark2_lv, length - classmark_offset, + mi_string, mi_type); +} + +struct msgb *gsm48_create_loc_upd_rej(uint8_t cause) +{ + struct gsm48_hdr *gh; + struct msgb *msg; + + msg = gsm48_msgb_alloc(); + if (!msg) + return NULL; + + gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1); + gh->proto_discr = GSM48_PDISC_MM; + gh->msg_type = GSM48_MT_MM_LOC_UPD_REJECT; + gh->data[0] = cause; + return msg; +} + +struct msgb *gsm48_create_mm_serv_rej(enum gsm48_reject_value value) +{ + struct msgb *msg; + struct gsm48_hdr *gh; + + msg = gsm48_msgb_alloc(); + if (!msg) + return NULL; + + gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1); + gh->proto_discr = GSM48_PDISC_MM; + gh->msg_type = GSM48_MT_MM_CM_SERV_REJ; + gh->data[0] = value; + + return msg; +} |