diff options
Diffstat (limited to 'openbsc/src/gsm_04_08_utils.c')
-rw-r--r-- | openbsc/src/gsm_04_08_utils.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/openbsc/src/gsm_04_08_utils.c b/openbsc/src/gsm_04_08_utils.c new file mode 100644 index 000000000..50deb2bcb --- /dev/null +++ b/openbsc/src/gsm_04_08_utils.c @@ -0,0 +1,310 @@ +/* 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 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 <stdio.h> +#include <stdlib.h> +#include <netinet/in.h> + +#include <openbsc/msgb.h> +#include <openbsc/debug.h> +#include <openbsc/gsm_04_08.h> +#include <openbsc/transaction.h> + +#define GSM48_ALLOC_SIZE 1024 +#define GSM48_ALLOC_HEADROOM 128 + +/* 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; + + +const char *gsm0408_cc_msg_names[] = { + "unknown 0x00", + "ALERTING", + "CALL_PROC", + "PROGRESS", + "ESTAB", + "SETUP", + "ESTAB_CONF", + "CONNECT", + "CALL_CONF", + "START_CC", + "unknown 0x0a", + "RECALL", + "unknown 0x0c", + "unknown 0x0d", + "EMERG_SETUP", + "CONNECT_ACK", + "USER_INFO", + "unknown 0x11", + "unknown 0x12", + "MODIFY_REJECT", + "unknown 0x14", + "unknown 0x15", + "unknown 0x16", + "MODIFY", + "HOLD", + "HOLD_ACK", + "HOLD_REJ", + "unknown 0x1b", + "RETR", + "RETR_ACK", + "RETR_REJ", + "MODIFY_COMPL", + "unknown 0x20", + "unknown 0x21", + "unknown 0x22", + "unknown 0x23", + "unknown 0x24", + "DISCONNECT", + "unknown 0x26", + "unknown 0x27", + "unknown 0x28", + "unknown 0x29", + "RELEASE_COMPL", + "unknown 0x2b", + "unknown 0x2c", + "RELEASE", + "unknown 0x2e", + "unknown 0x2f", + "unknown 0x30", + "STOP_DTMF", + "STOP_DTMF_ACK", + "unknown 0x33", + "STATUS_ENQ", + "START_DTMF", + "START_DTMF_ACK", + "START_DTMF_REJ", + "unknown 0x38", + "CONG_CTRL", + "FACILITY", + "unknown 0x3b", + "STATUS", + "unknown 0x3c", + "NOTIFY", + "unknown 0x3f", +}; + + +struct msgb *gsm48_msgb_alloc(void) +{ + return msgb_alloc_headroom(GSM48_ALLOC_SIZE, GSM48_ALLOC_HEADROOM, + "GSM 04.08"); +} + +int gsm48_sendmsg(struct msgb *msg, struct gsm_trans *trans) +{ + struct gsm48_hdr *gh = (struct gsm48_hdr *) msg->data; + + /* if we get passed a transaction reference, do some common + * work that the caller no longer has to do */ + if (trans) { + gh->proto_discr = trans->protocol | (trans->transaction_id << 4); + msg->lchan = trans->lchan; + } + + if (msg->lchan) { + msg->trx = msg->lchan->ts->trx; + + if ((gh->proto_discr & GSM48_PDISC_MASK) == GSM48_PDISC_CC) + DEBUGP(DCC, "(bts %d trx %d ts %d ti %02x) " + "Sending '%s' to MS.\n", msg->trx->bts->nr, + msg->trx->nr, msg->lchan->ts->nr, + gh->proto_discr & 0xf0, + gsm0408_cc_msg_names[gh->msg_type & 0x3f]); + else + DEBUGP(DCC, "(bts %d trx %d ts %d pd %02x) " + "Sending 0x%02x to MS.\n", msg->trx->bts->nr, + msg->trx->nr, msg->lchan->ts->nr, + gh->proto_discr, gh->msg_type); + } + + msg->l3h = msg->data; + + return rsl_data_request(msg, 0); +} + +static void to_bcd(u_int8_t *bcd, u_int16_t val) +{ + bcd[2] = val % 10; + val = val / 10; + bcd[1] = val % 10; + val = val / 10; + bcd[0] = val % 10; + val = val / 10; +} + +void gsm0408_generate_lai(struct gsm48_loc_area_id *lai48, u_int16_t mcc, + u_int16_t mnc, u_int16_t lac) +{ + u_int8_t bcd[3]; + + to_bcd(bcd, mcc); + lai48->digits[0] = bcd[0] | (bcd[1] << 4); + lai48->digits[1] = bcd[2]; + + to_bcd(bcd, mnc); + /* FIXME: do we need three-digit MNC? See Table 10.5.3 */ +#if 0 + lai48->digits[1] |= bcd[2] << 4; + lai48->digits[2] = bcd[0] | (bcd[1] << 4); +#else + lai48->digits[1] |= 0xf << 4; + lai48->digits[2] = bcd[1] | (bcd[2] << 4); +#endif + + lai48->lac = htons(lac); +} + +int generate_mid_from_tmsi(u_int8_t *buf, u_int32_t tmsi) +{ + u_int32_t *tptr = (u_int32_t *) &buf[3]; + + buf[0] = GSM48_IE_MOBILE_ID; + buf[1] = GSM48_TMSI_LEN; + buf[2] = 0xf0 | GSM_MI_TYPE_TMSI; + *tptr = htonl(tmsi); + + return 7; +} + +/* Section 9.1.8 / Table 9.9 */ +struct chreq { + u_int8_t val; + u_int8_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_SDCCH }, + { 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 }, + { 0x20, 0xf0, CHREQ_T_PAG_R_TCH_F }, + { 0x30, 0xf0, CHREQ_T_PAG_R_TCH_FH }, +}; + +/* 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 }, + { 0x20, 0xf0, CHREQ_T_PAG_R_TCH_F }, + { 0x30, 0xf0, CHREQ_T_PAG_R_TCH_FH }, +}; + +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] = GSM_LCHAN_SDCCH, + [CHREQ_T_PAG_R_TCH_F] = GSM_LCHAN_TCH_F, + [CHREQ_T_PAG_R_TCH_FH] = GSM_LCHAN_TCH_F, +}; + +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_OTHER, + [CHREQ_T_DATA_CALL_TCH_H] = GSM_CHREQ_REASON_OTHER, + [CHREQ_T_LOCATION_UPD] = GSM_CHREQ_REASON_LOCATION_UPD, + [CHREQ_T_PAG_R_ANY] = GSM_CHREQ_REASON_PAG, + [CHREQ_T_PAG_R_TCH_F] = GSM_CHREQ_REASON_PAG, + [CHREQ_T_PAG_R_TCH_FH] = GSM_CHREQ_REASON_PAG, +}; + +enum gsm_chan_t get_ctype_by_chreq(struct gsm_bts *bts, u_int8_t ra) +{ + int i; + /* FIXME: determine if we set NECI = 0 in the BTS SI4 */ + + for (i = 0; i < ARRAY_SIZE(chreq_type_neci0); i++) { + const struct chreq *chr = &chreq_type_neci0[i]; + if ((ra & chr->mask) == chr->val) + return ctype_by_chreq[chr->type]; + } + fprintf(stderr, "Unknown CHANNEL REQUEST RQD 0x%02x\n", ra); + return GSM_LCHAN_SDCCH; +} + +enum gsm_chreq_reason_t get_reason_by_chreq(struct gsm_bts *bts, u_int8_t ra) +{ + int i; + /* FIXME: determine if we set NECI = 0 in the BTS SI4 */ + + for (i = 0; i < ARRAY_SIZE(chreq_type_neci0); i++) { + const struct chreq *chr = &chreq_type_neci0[i]; + if ((ra & chr->mask) == chr->val) + return reason_by_chreq[chr->type]; + } + fprintf(stderr, "Unknown CHANNEL REQUEST REASON 0x%02x\n", ra); + return GSM_CHREQ_REASON_OTHER; +} + +/* 7.1.7 and 9.1.7: RR CHANnel RELease */ +int gsm48_send_rr_release(struct gsm_lchan *lchan) +{ + struct msgb *msg = gsm48_msgb_alloc(); + struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + u_int8_t *cause; + + msg->lchan = lchan; + gh->proto_discr = GSM48_PDISC_RR; + gh->msg_type = GSM48_MT_RR_CHAN_REL; + + cause = msgb_put(msg, 1); + cause[0] = GSM48_RR_CAUSE_NORMAL; + + DEBUGP(DRR, "Sending Channel Release: Chan: Number: %d Type: %d\n", + lchan->nr, lchan->type); + + /* Send actual release request to MS */ + gsm48_sendmsg(msg, NULL); + /* FIXME: Start Timer T3109 */ + + /* Deactivate the SACCH on the BTS side */ + return rsl_deact_sacch(lchan); +} + |