[bsc] Move the GSM 04.08 helper functions to gsm_04_08_utils.c
The existing gsm_04_08.c implementation is mixing BSC and MSC
behavior. Move some simple parsing and generation functions over
to gsm_04_08_utils.c to allow a different MSC to define the policy.
diff --git a/openbsc/src/gsm_04_08_utils.c b/openbsc/src/gsm_04_08_utils.c
new file mode 100644
index 0000000..50deb2b
--- /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);
+}
+