re-structure the OpenBSC directory layout

The new structure divides the code into a number of libraries
for the BSC core functionality, MSC core functionality, Abis transport,
TRAU and other bits.

This doesn't introduce any functional code change but simply moves
around files and alters Makefile.am accordingly.

Next step would be to disentangle a lot of the inter-library
dependencies and make the individual bits of code more independent.

1 files changed, 507 insertions, 0 deletions

diff --git a/openbsc/src/bsc/chan_alloc.c b/openbsc/src/bsc/chan_alloc.c
new file mode 100644
index 000000000..167381b37
--- /dev/null
+++ b/openbsc/src/bsc/chan_alloc.c
@@ -0,0 +1,507 @@
+/* GSM Channel allocation routines
+ *
+ * (C) 2008 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 <string.h>
+#include <errno.h>
+
+#include <openbsc/gsm_subscriber.h>
+#include <openbsc/chan_alloc.h>
+#include <openbsc/abis_nm.h>
+#include <openbsc/abis_rsl.h>
+#include <openbsc/debug.h>
+#include <openbsc/signal.h>
+
+#include <osmocore/talloc.h>
+
+static int ts_is_usable(struct gsm_bts_trx_ts *ts)
+{
+	/* FIXME: How does this behave for BS-11 ? */
+	if (is_ipaccess_bts(ts->trx->bts)) {
+		if (!nm_is_running(&ts->nm_state))
+			return 0;
+	}
+
+	return 1;
+}
+
+int trx_is_usable(struct gsm_bts_trx *trx)
+{
+	/* FIXME: How does this behave for BS-11 ? */
+	if (is_ipaccess_bts(trx->bts)) {
+		if (!nm_is_running(&trx->nm_state) ||
+		    !nm_is_running(&trx->bb_transc.nm_state))
+			return 0;
+	}
+
+	return 1;
+}
+
+struct gsm_bts_trx_ts *ts_c0_alloc(struct gsm_bts *bts,
+				   enum gsm_phys_chan_config pchan)
+{
+	struct gsm_bts_trx *trx = bts->c0;
+	struct gsm_bts_trx_ts *ts = &trx->ts[0];
+
+	if (pchan != GSM_PCHAN_CCCH &&
+	    pchan != GSM_PCHAN_CCCH_SDCCH4)
+		return NULL;
+
+	if (ts->pchan != GSM_PCHAN_NONE)
+		return NULL;
+
+	ts->pchan = pchan;
+
+	return ts;
+}
+
+/* Allocate a physical channel (TS) */
+struct gsm_bts_trx_ts *ts_alloc(struct gsm_bts *bts,
+				enum gsm_phys_chan_config pchan)
+{
+	int j;
+	struct gsm_bts_trx *trx;
+
+	llist_for_each_entry(trx, &bts->trx_list, list) {
+		int from, to;
+
+		if (!trx_is_usable(trx))
+			continue;
+
+		/* the following constraints are pure policy,
+		 * no requirement to put this restriction in place */
+		if (trx == bts->c0) {
+			/* On the first TRX we run one CCCH and one SDCCH8 */
+			switch (pchan) {
+			case GSM_PCHAN_CCCH:
+			case GSM_PCHAN_CCCH_SDCCH4:
+				from = 0; to = 0;
+				break;
+			case GSM_PCHAN_TCH_F:
+			case GSM_PCHAN_TCH_H:
+				from = 1; to = 7;
+				break;
+			case GSM_PCHAN_SDCCH8_SACCH8C:
+			default:
+				return NULL;
+			}
+		} else {
+			/* Every secondary TRX is configured for TCH/F
+			 * and TCH/H only */
+			switch (pchan) {
+			case GSM_PCHAN_SDCCH8_SACCH8C:
+				from = 1; to = 1;
+			case GSM_PCHAN_TCH_F:
+			case GSM_PCHAN_TCH_H:
+				from = 1; to = 7;
+				break;
+			default:
+				return NULL;
+			}
+		}
+
+		for (j = from; j <= to; j++) {
+			struct gsm_bts_trx_ts *ts = &trx->ts[j];
+
+			if (!ts_is_usable(ts))
+				continue;
+
+			if (ts->pchan == GSM_PCHAN_NONE) {
+				ts->pchan = pchan;
+				/* set channel attribute on OML */
+				abis_nm_set_channel_attr(ts, abis_nm_chcomb4pchan(pchan));
+				return ts;
+			}
+		}
+	}
+	return NULL;
+}
+
+/* Free a physical channel (TS) */
+void ts_free(struct gsm_bts_trx_ts *ts)
+{
+	ts->pchan = GSM_PCHAN_NONE;
+}
+
+static const u_int8_t subslots_per_pchan[] = {
+	[GSM_PCHAN_NONE] = 0,
+	[GSM_PCHAN_CCCH] = 0,
+	[GSM_PCHAN_CCCH_SDCCH4] = 4,
+	[GSM_PCHAN_TCH_F] = 1,
+	[GSM_PCHAN_TCH_H] = 2,
+	[GSM_PCHAN_SDCCH8_SACCH8C] = 8,
+	/* FIXME: what about dynamic TCH_F_TCH_H ? */
+	[GSM_PCHAN_TCH_F_PDCH] = 1,
+};
+
+static struct gsm_lchan *
+_lc_find_trx(struct gsm_bts_trx *trx, enum gsm_phys_chan_config pchan)
+{
+	struct gsm_bts_trx_ts *ts;
+	int j, ss;
+
+	if (!trx_is_usable(trx))
+		return NULL;
+
+	for (j = 0; j < 8; j++) {
+		ts = &trx->ts[j];
+		if (!ts_is_usable(ts))
+			continue;
+		/* ip.access dynamic TCH/F + PDCH combination */
+		if (ts->pchan == GSM_PCHAN_TCH_F_PDCH &&
+		    pchan == GSM_PCHAN_TCH_F) {
+			/* we can only consider such a dynamic channel
+			 * if the PDCH is currently inactive */
+			if (ts->flags & TS_F_PDCH_MODE)
+				continue;
+		} else if (ts->pchan != pchan)
+			continue;
+		/* check if all sub-slots are allocated yet */
+		for (ss = 0; ss < subslots_per_pchan[pchan]; ss++) {
+			struct gsm_lchan *lc = &ts->lchan[ss];
+			if (lc->type == GSM_LCHAN_NONE &&
+			    lc->state == LCHAN_S_NONE)
+				return lc;
+		}
+	}
+
+	return NULL;
+}
+
+static struct gsm_lchan *
+_lc_find_bts(struct gsm_bts *bts, enum gsm_phys_chan_config pchan)
+{
+	struct gsm_bts_trx *trx;
+	struct gsm_bts_trx_ts *ts;
+	struct gsm_lchan *lc;
+
+	if (bts->chan_alloc_reverse) {
+		llist_for_each_entry_reverse(trx, &bts->trx_list, list) {
+			lc = _lc_find_trx(trx, pchan);
+			if (lc)
+				return lc;
+		}
+	} else {
+		llist_for_each_entry(trx, &bts->trx_list, list) {
+			lc = _lc_find_trx(trx, pchan);
+			if (lc)
+				return lc;
+		}
+	}
+
+	/* we cannot allocate more of these */
+	if (pchan == GSM_PCHAN_CCCH_SDCCH4)
+		return NULL;
+
+	/* if we've reached here, we need to allocate a new physical
+	 * channel for the logical channel type requested */
+	ts = ts_alloc(bts, pchan);
+	if (!ts) {
+		/* no more radio resources */
+		return NULL;
+	}
+	return &ts->lchan[0];
+}
+
+/* Allocate a logical channel */
+struct gsm_lchan *lchan_alloc(struct gsm_bts *bts, enum gsm_chan_t type,
+			      int allow_bigger)
+{
+	struct gsm_lchan *lchan = NULL;
+	enum gsm_phys_chan_config first, second;
+
+	switch (type) {
+	case GSM_LCHAN_SDCCH:
+		if (bts->chan_alloc_reverse) {
+			first = GSM_PCHAN_SDCCH8_SACCH8C;
+			second = GSM_PCHAN_CCCH_SDCCH4;
+		} else {
+			first = GSM_PCHAN_CCCH_SDCCH4;
+			second = GSM_PCHAN_SDCCH8_SACCH8C;
+		}
+
+		lchan = _lc_find_bts(bts, first);
+		if (lchan == NULL)
+			lchan = _lc_find_bts(bts, second);
+
+		/* allow to assign bigger channels */
+		if (allow_bigger) {
+			if (lchan == NULL) {
+				lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_H);
+				type = GSM_LCHAN_TCH_H;
+			}
+
+			if (lchan == NULL) {
+				lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F);
+				type = GSM_LCHAN_TCH_F;
+			}
+		}
+		break;
+	case GSM_LCHAN_TCH_F:
+		lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F);
+		break;
+	case GSM_LCHAN_TCH_H:
+		lchan =_lc_find_bts(bts, GSM_PCHAN_TCH_H);
+		/* If we don't have TCH/H available, fall-back to TCH/F */
+		if (!lchan) {
+			lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F);
+			type = GSM_LCHAN_TCH_F;
+		}
+		break;
+	default:
+		LOGP(DRLL, LOGL_ERROR, "Unknown gsm_chan_t %u\n", type);
+	}
+
+	if (lchan) {
+		lchan->type = type;
+
+		/* clear sapis */
+		memset(lchan->sapis, 0, ARRAY_SIZE(lchan->sapis));
+
+		/* clear multi rate config */
+		memset(&lchan->mr_conf, 0, sizeof(lchan->mr_conf));
+	} else {
+		struct challoc_signal_data sig;
+		sig.bts = bts;
+		sig.type = type;
+		dispatch_signal(SS_CHALLOC, S_CHALLOC_ALLOC_FAIL, &sig);
+	}
+
+	return lchan;
+}
+
+/* Free a logical channel */
+void lchan_free(struct gsm_lchan *lchan)
+{
+	struct challoc_signal_data sig;
+	int i;
+
+	sig.type = lchan->type;
+	lchan->type = GSM_LCHAN_NONE;
+
+
+	if (lchan->conn) {
+		struct lchan_signal_data sig;
+
+		/* We might kill an active channel... */
+		sig.lchan = lchan;
+		sig.mr = NULL;
+		dispatch_signal(SS_LCHAN, S_LCHAN_UNEXPECTED_RELEASE, &sig);
+	}
+
+
+	/* stop the timer */
+	bsc_del_timer(&lchan->T3101);
+
+	/* clear cached measuement reports */
+	lchan->meas_rep_idx = 0;
+	for (i = 0; i < ARRAY_SIZE(lchan->meas_rep); i++) {
+		lchan->meas_rep[i].flags = 0;
+		lchan->meas_rep[i].nr = 0;
+	}
+	for (i = 0; i < ARRAY_SIZE(lchan->neigh_meas); i++)
+		lchan->neigh_meas[i].arfcn = 0;
+
+	if (lchan->rqd_ref) {
+		talloc_free(lchan->rqd_ref);
+		lchan->rqd_ref = NULL;
+		lchan->rqd_ta = 0;
+	}
+
+	sig.lchan = lchan;
+	sig.bts = lchan->ts->trx->bts;
+	dispatch_signal(SS_CHALLOC, S_CHALLOC_FREED, &sig);
+
+	if (lchan->conn) {
+		LOGP(DRLL, LOGL_ERROR, "the subscriber connection should be gone.\n");
+		lchan->conn = NULL;
+	}
+
+	lchan->sach_deact = 0;
+	lchan->release_reason = 0;
+
+	/* FIXME: ts_free() the timeslot, if we're the last logical
+	 * channel using it */
+}
+
+/*
+ * There was an error with the TRX and we need to forget
+ * any state so that a lchan can be allocated again after
+ * the trx is fully usable.
+ *
+ * This should be called after lchan_free to force a channel
+ * be available for allocation again. This means that this
+ * method will stop the "delay after error"-timer and set the
+ * state to LCHAN_S_NONE.
+ */
+void lchan_reset(struct gsm_lchan *lchan)
+{
+	bsc_del_timer(&lchan->T3101);
+	bsc_del_timer(&lchan->T3111);
+	bsc_del_timer(&lchan->error_timer);
+
+	lchan->type = GSM_LCHAN_NONE;
+	lchan->state = LCHAN_S_NONE;
+}
+
+/* release the next allocated SAPI or return 0 */
+static int _lchan_release_next_sapi(struct gsm_lchan *lchan)
+{
+	int sapi;
+
+	for (sapi = 1; sapi < ARRAY_SIZE(lchan->sapis); ++sapi) {
+		u_int8_t link_id;
+		if (lchan->sapis[sapi] == LCHAN_SAPI_UNUSED)
+			continue;
+
+		link_id = sapi;
+		if (lchan->type == GSM_LCHAN_TCH_F || lchan->type == GSM_LCHAN_TCH_H)
+			link_id |= 0x40;
+		rsl_release_request(lchan, link_id, lchan->release_reason);
+		return 0;
+	}
+
+	return 1;
+}
+
+/* Drive the release process of the lchan */
+static void _lchan_handle_release(struct gsm_lchan *lchan)
+{
+	/* Ask for SAPI != 0 to be freed first and stop if we need to wait */
+	if (_lchan_release_next_sapi(lchan) == 0)
+		return;
+
+	if (lchan->sach_deact) {
+		gsm48_send_rr_release(lchan);
+		return;
+	}
+
+	rsl_release_request(lchan, 0, lchan->release_reason);
+	rsl_lchan_set_state(lchan, LCHAN_S_REL_REQ);
+}
+
+/* called from abis rsl */
+int rsl_lchan_rll_release(struct gsm_lchan *lchan, u_int8_t link_id)
+{
+	if (lchan->state != LCHAN_S_REL_REQ)
+		return -1;
+
+	if ((link_id & 0x7) != 0)
+		_lchan_handle_release(lchan);
+	return 0;
+}
+
+/* Consider releasing the channel now */
+int lchan_release(struct gsm_lchan *lchan, int sach_deact, int reason)
+{
+	DEBUGP(DRLL, "%s starting release sequence\n", gsm_lchan_name(lchan));
+	rsl_lchan_set_state(lchan, LCHAN_S_REL_REQ);
+
+	lchan->conn = NULL;
+	lchan->release_reason = reason;
+	lchan->sach_deact = sach_deact;
+	_lchan_handle_release(lchan);
+	return 1;
+}
+
+static struct gsm_lchan* lchan_find(struct gsm_bts *bts, struct gsm_subscriber *subscr) {
+	struct gsm_bts_trx *trx;
+	int ts_no, lchan_no;
+
+	llist_for_each_entry(trx, &bts->trx_list, list) {
+		for (ts_no = 0; ts_no < 8; ++ts_no) {
+			for (lchan_no = 0; lchan_no < TS_MAX_LCHAN; ++lchan_no) {
+				struct gsm_lchan *lchan =
+					&trx->ts[ts_no].lchan[lchan_no];
+				if (lchan->conn && subscr == lchan->conn->subscr)
+					return lchan;
+			}
+		}
+	}
+
+	return NULL;
+}
+
+struct gsm_subscriber_connection *connection_for_subscr(struct gsm_subscriber *subscr)
+{
+	struct gsm_bts *bts;
+	struct gsm_network *net = subscr->net;
+	struct gsm_lchan *lchan;
+
+	llist_for_each_entry(bts, &net->bts_list, list) {
+		lchan = lchan_find(bts, subscr);
+		if (lchan)
+			return lchan->conn;
+	}
+
+	return NULL;
+}
+
+void bts_chan_load(struct pchan_load *cl, const struct gsm_bts *bts)
+{
+	struct gsm_bts_trx *trx;
+
+	llist_for_each_entry(trx, &bts->trx_list, list) {
+		int i;
+
+		/* skip administratively deactivated tranxsceivers */
+		if (!nm_is_running(&trx->nm_state) ||
+		    !nm_is_running(&trx->bb_transc.nm_state))
+			continue;
+
+		for (i = 0; i < ARRAY_SIZE(trx->ts); i++) {
+			struct gsm_bts_trx_ts *ts = &trx->ts[i];
+			struct load_counter *pl = &cl->pchan[ts->pchan];
+			int j;
+
+			/* skip administratively deactivated timeslots */
+			if (!nm_is_running(&ts->nm_state))
+				continue;
+
+			for (j = 0; j < subslots_per_pchan[ts->pchan]; j++) {
+				struct gsm_lchan *lchan = &ts->lchan[j];
+
+				pl->total++;
+
+				switch (lchan->state) {
+				case LCHAN_S_NONE:
+					break;
+				default:
+					pl->used++;
+					break;
+				}
+			}
+		}
+	}
+}
+
+void network_chan_load(struct pchan_load *pl, struct gsm_network *net)
+{
+	struct gsm_bts *bts;
+
+	memset(pl, 0, sizeof(*pl));
+
+	llist_for_each_entry(bts, &net->bts_list, list)
+		bts_chan_load(pl, bts);
+}
+