move openbsc/* to repos root

This is the first step in creating this repository from the legacy openbsc.git.

Like all other Osmocom repositories, keep the autoconf and automake files in
the repository root. openbsc.git has been the sole exception, which ends now.

Change-Id: I9c6f2a448d9cb1cc088cf1cf6918b69d7e69b4e7

1 files changed, 543 insertions, 0 deletions

diff --git a/src/libbsc/chan_alloc.c b/src/libbsc/chan_alloc.c
new file mode 100644
index 000000000..33b79a0b2
--- /dev/null
+++ b/src/libbsc/chan_alloc.c
@@ -0,0 +1,543 @@
+/* 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/rtp_proxy.h>
+#include <openbsc/signal.h>
+
+#include <osmocom/core/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->mo.nm_state))
+			return 0;
+	}
+
+	/* If a TCH/F_PDCH TS is busy changing, it is already taken or not
+	 * yet available. */
+	if (ts->pchan == GSM_PCHAN_TCH_F_PDCH) {
+		if (ts->flags & TS_F_PDCH_PENDING_MASK)
+			return 0;
+	}
+
+	/* If a dynamic channel is busy changing, it is already taken or not
+	 * yet available. */
+	if (ts->pchan == GSM_PCHAN_TCH_F_TCH_H_PDCH) {
+		if (ts->dyn.pchan_is != ts->dyn.pchan_want)
+			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->mo.nm_state) ||
+		    !nm_is_running(&trx->bb_transc.mo.nm_state))
+			return 0;
+	}
+
+	return 1;
+}
+
+static struct gsm_lchan *
+_lc_find_trx(struct gsm_bts_trx *trx, enum gsm_phys_chan_config pchan,
+	     enum gsm_phys_chan_config dyn_as_pchan)
+{
+	struct gsm_bts_trx_ts *ts;
+	int j, start, stop, dir, ss;
+	int check_subslots;
+
+	if (!trx_is_usable(trx))
+		return NULL;
+
+	if (trx->bts->chan_alloc_reverse) {
+		/* check TS 7..0 */
+		start = 7;
+		stop = -1;
+		dir = -1;
+	} else {
+		/* check TS 0..7 */
+		start = 0;
+		stop = 8;
+		dir = 1;
+	}
+
+	for (j = start; j != stop; j += dir) {
+		ts = &trx->ts[j];
+		if (!ts_is_usable(ts))
+			continue;
+		if (ts->pchan != pchan)
+			continue;
+
+		/*
+		 * Allocation for fully dynamic timeslots
+		 * (does not apply for ip.access style GSM_PCHAN_TCH_F_PDCH)
+		 *
+		 * Note the special nature of a dynamic timeslot in PDCH mode:
+		 * in PDCH mode, typically, lchan->type is GSM_LCHAN_NONE and
+		 * lchan->state is LCHAN_S_NONE -- an otherwise unused slot
+		 * becomes PDCH implicitly. In the same sense, this channel
+		 * allocator will never be asked to find an available PDCH
+		 * slot; only TCH/F or TCH/H will be requested, and PDCH mode
+		 * means that it is available for switchover.
+		 *
+		 * A dynamic timeslot in PDCH mode may be switched to TCH/F or
+		 * TCH/H. If a dyn TS is already in TCH/F or TCH/H mode, it
+		 * means that it is in use and its mode can't be switched.
+		 *
+		 * The logic concerning channels for TCH/F is trivial: there is
+		 * only one channel, so a dynamic TS in TCH/F mode is already
+		 * taken and not available for allocation. For TCH/H, we need
+		 * to check whether a dynamic timeslot is already in TCH/H mode
+		 * and whether one of the two channels is still available.
+		 */
+		switch (pchan) {
+		case GSM_PCHAN_TCH_F_TCH_H_PDCH:
+			if (ts->dyn.pchan_is != ts->dyn.pchan_want) {
+				/* The TS's mode is being switched. Not
+				 * available anymore/yet. */
+				DEBUGP(DRLL, "%s already in switchover\n",
+				       gsm_ts_and_pchan_name(ts));
+				continue;
+			}
+			if (ts->dyn.pchan_is == GSM_PCHAN_PDCH) {
+				/* This slot is available. Still check for
+				 * error states to be sure; in all cases the
+				 * first lchan will be used. */
+				if (ts->lchan->state != LCHAN_S_NONE
+				    && ts->lchan->state != LCHAN_S_ACTIVE)
+					continue;
+				return ts->lchan;
+			}
+			if (ts->dyn.pchan_is != dyn_as_pchan)
+				/* not applicable. */
+				continue;
+			/* The requested type matches the dynamic timeslot's
+			 * current mode. A channel may still be available
+			 * (think TCH/H). */
+			check_subslots = ts_subslots(ts);
+			break;
+
+		case GSM_PCHAN_TCH_F_PDCH:
+			/* Available for voice when in PDCH mode */
+			if (ts_pchan(ts) != GSM_PCHAN_PDCH)
+				continue;
+			/* Subslots of a PDCH ts don't need to be checked. */
+			return ts->lchan;
+
+		default:
+			/* Not a dynamic channel, there is only one pchan kind: */
+			check_subslots = ts_subslots(ts);
+			break;
+		}
+
+		/* Is a sub-slot still available? */
+		for (ss = 0; ss < check_subslots; 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_dyn_find_bts(struct gsm_bts *bts, enum gsm_phys_chan_config pchan,
+		 enum gsm_phys_chan_config dyn_as_pchan)
+{
+	struct gsm_bts_trx *trx;
+	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, dyn_as_pchan);
+			if (lc)
+				return lc;
+		}
+	} else {
+		llist_for_each_entry(trx, &bts->trx_list, list) {
+			lc = _lc_find_trx(trx, pchan, dyn_as_pchan);
+			if (lc)
+				return lc;
+		}
+	}
+
+	return NULL;
+}
+
+static struct gsm_lchan *
+_lc_find_bts(struct gsm_bts *bts, enum gsm_phys_chan_config pchan)
+{
+	return _lc_dyn_find_bts(bts, pchan, GSM_PCHAN_NONE);
+}
+
+/* Allocate a logical channel.
+ *
+ * Dynamic channel types: we always prefer a dedicated TS, and only pick +
+ * switch a dynamic TS if no pure TS of the requested PCHAN is available.
+ *
+ * TCH_F/PDCH: if we pick a PDCH ACT style dynamic TS as TCH/F channel, PDCH
+ * will be disabled in rsl_chan_activate_lchan(); there is no need to check
+ * whether PDCH mode is currently active, here.
+ */
+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, first_cbch, second, second_cbch;
+
+	switch (type) {
+	case GSM_LCHAN_SDCCH:
+		if (bts->chan_alloc_reverse) {
+			first = GSM_PCHAN_SDCCH8_SACCH8C;
+			first_cbch = GSM_PCHAN_SDCCH8_SACCH8C_CBCH;
+			second = GSM_PCHAN_CCCH_SDCCH4;
+			second_cbch = GSM_PCHAN_CCCH_SDCCH4_CBCH;
+		} else {
+			first = GSM_PCHAN_CCCH_SDCCH4;
+			first_cbch = GSM_PCHAN_CCCH_SDCCH4_CBCH;
+			second = GSM_PCHAN_SDCCH8_SACCH8C;
+			second_cbch = GSM_PCHAN_SDCCH8_SACCH8C_CBCH;
+		}
+
+		lchan = _lc_find_bts(bts, first);
+		if (lchan == NULL)
+			lchan = _lc_find_bts(bts, first_cbch);
+		if (lchan == NULL)
+			lchan = _lc_find_bts(bts, second);
+		if (lchan == NULL)
+			lchan = _lc_find_bts(bts, second_cbch);
+
+		/* allow to assign bigger channels */
+		if (allow_bigger) {
+			if (lchan == NULL) {
+				lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_H);
+				if (lchan)
+					type = GSM_LCHAN_TCH_H;
+			}
+
+			if (lchan == NULL) {
+				lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F);
+				if (lchan)
+					type = GSM_LCHAN_TCH_F;
+			}
+
+			/* try dynamic TCH/F_PDCH */
+			if (lchan == NULL) {
+				lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F_PDCH);
+				/* TCH/F_PDCH will be used as TCH/F */
+				if (lchan)
+					type = GSM_LCHAN_TCH_F;
+			}
+
+			/* try fully dynamic TCH/F_TCH/H_PDCH */
+			if (lchan == NULL) {
+				lchan = _lc_dyn_find_bts(bts, GSM_PCHAN_TCH_F_TCH_H_PDCH,
+							 GSM_PCHAN_TCH_H);
+				if (lchan)
+					type = GSM_LCHAN_TCH_H;
+			}
+			/*
+			 * No need to check fully dynamic channels for TCH/F:
+			 * if no TCH/H was available, neither will be TCH/F.
+			 */
+		}
+		break;
+	case GSM_LCHAN_TCH_F:
+		lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F);
+		/* If we don't have TCH/F available, fall-back to TCH/H */
+		if (!lchan) {
+			lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_H);
+			if (lchan)
+				type = GSM_LCHAN_TCH_H;
+		}
+		/* If we don't have TCH/H either, try dynamic TCH/F_PDCH */
+		if (!lchan) {
+			lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F_PDCH);
+			/* TCH/F_PDCH used as TCH/F -- here, type is already
+			 * set to GSM_LCHAN_TCH_F, but for clarity's sake... */
+			if (lchan)
+				type = GSM_LCHAN_TCH_F;
+		}
+
+		/* Try fully dynamic TCH/F_TCH/H_PDCH as TCH/F... */
+		if (!lchan && bts->network->dyn_ts_allow_tch_f) {
+			lchan = _lc_dyn_find_bts(bts,
+						 GSM_PCHAN_TCH_F_TCH_H_PDCH,
+						 GSM_PCHAN_TCH_F);
+			if (lchan)
+				type = GSM_LCHAN_TCH_F;
+		}
+		/* ...and as TCH/H. */
+		if (!lchan) {
+			lchan = _lc_dyn_find_bts(bts,
+						 GSM_PCHAN_TCH_F_TCH_H_PDCH,
+						 GSM_PCHAN_TCH_H);
+			if (lchan)
+				type = GSM_LCHAN_TCH_H;
+		}
+		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);
+			if (lchan)
+				type = GSM_LCHAN_TCH_F;
+		}
+		/* No dedicated TCH/x available -- try fully dynamic
+		 * TCH/F_TCH/H_PDCH */
+		if (!lchan) {
+			lchan = _lc_dyn_find_bts(bts,
+						 GSM_PCHAN_TCH_F_TCH_H_PDCH,
+						 GSM_PCHAN_TCH_H);
+			if (lchan)
+				type = GSM_LCHAN_TCH_H;
+		}
+		/*
+		 * No need to check TCH/F_TCH/H_PDCH channels for TCH/F:
+		 * if no TCH/H was available, neither will be TCH/F.
+		 */
+		/* If we don't have TCH/F either, try dynamic TCH/F_PDCH */
+		if (!lchan) {
+			lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F_PDCH);
+			if (lchan)
+				type = GSM_LCHAN_TCH_F;
+		}
+		break;
+	default:
+		LOGP(DRLL, LOGL_ERROR, "Unknown gsm_chan_t %u\n", type);
+	}
+
+	if (lchan) {
+		lchan->type = type;
+
+		LOGP(DRLL, LOGL_INFO, "%s Allocating lchan=%u as %s\n",
+		     gsm_ts_and_pchan_name(lchan->ts),
+		     lchan->nr, gsm_lchant_name(lchan->type));
+
+		/* clear sapis */
+		memset(lchan->sapis, 0, ARRAY_SIZE(lchan->sapis));
+
+		/* clear multi rate config */
+		memset(&lchan->mr_ms_lv, 0, sizeof(lchan->mr_ms_lv));
+		memset(&lchan->mr_bts_lv, 0, sizeof(lchan->mr_bts_lv));
+		lchan->broken_reason = "";
+	} else {
+		struct challoc_signal_data sig;
+
+		LOGP(DRLL, LOGL_ERROR, "Failed to allocate %s channel\n",
+		     gsm_lchant_name(type));
+
+		sig.bts = bts;
+		sig.type = type;
+		osmo_signal_dispatch(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;
+		osmo_signal_dispatch(SS_LCHAN, S_LCHAN_UNEXPECTED_RELEASE, &sig);
+	}
+
+	if (lchan->abis_ip.rtp_socket) {
+		LOGP(DRLL, LOGL_ERROR, "%s RTP Proxy Socket remained open.\n",
+			gsm_lchan_name(lchan));
+		rtp_socket_free(lchan->abis_ip.rtp_socket);
+		lchan->abis_ip.rtp_socket = NULL;
+	}
+
+	/* stop the timer */
+	osmo_timer_del(&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;
+	osmo_signal_dispatch(SS_CHALLOC, S_CHALLOC_FREED, &sig);
+
+	if (lchan->conn) {
+		LOGP(DRLL, LOGL_ERROR, "the subscriber connection should be gone.\n");
+		lchan->conn = NULL;
+	}
+
+	/* 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)
+{
+	osmo_timer_del(&lchan->T3101);
+	osmo_timer_del(&lchan->T3109);
+	osmo_timer_del(&lchan->T3111);
+	osmo_timer_del(&lchan->error_timer);
+
+	lchan->type = GSM_LCHAN_NONE;
+	lchan->state = LCHAN_S_NONE;
+
+	if (lchan->abis_ip.rtp_socket) {
+		rtp_socket_free(lchan->abis_ip.rtp_socket);
+		lchan->abis_ip.rtp_socket = NULL;
+	}
+}
+
+/* Drive the release process of the lchan */
+static void _lchan_handle_release(struct gsm_lchan *lchan,
+				  int sacch_deact, int mode)
+{
+	/* Release all SAPIs on the local end and continue */
+	rsl_release_sapis_from(lchan, 1, RSL_REL_LOCAL_END);
+
+	/*
+	 * Shall we send a RR Release, start T3109 and wait for the
+	 * release indication from the BTS or just take it down (e.g.
+	 * on assignment requests)
+	 */
+	if (sacch_deact) {
+		gsm48_send_rr_release(lchan);
+
+		/* Deactivate the SACCH on the BTS side */
+		rsl_deact_sacch(lchan);
+		rsl_start_t3109(lchan);
+	} else if (lchan->sapis[0] == LCHAN_SAPI_UNUSED) {
+		rsl_direct_rf_release(lchan);
+	} else {
+		rsl_release_request(lchan, 0, mode);
+	}
+}
+
+/* Consider releasing the channel now */
+int lchan_release(struct gsm_lchan *lchan, int sacch_deact, enum rsl_rel_mode mode)
+{
+	DEBUGP(DRLL, "%s starting release sequence\n", gsm_lchan_name(lchan));
+	rsl_lchan_set_state(lchan, LCHAN_S_REL_REQ);
+
+	lchan->conn = NULL;
+	_lchan_handle_release(lchan, sacch_deact, mode);
+	return 1;
+}
+
+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->mo.nm_state) ||
+		    !nm_is_running(&trx->bb_transc.mo.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;
+			int subslots;
+
+			/* skip administratively deactivated timeslots */
+			if (!nm_is_running(&ts->mo.nm_state))
+				continue;
+
+			subslots = ts_subslots(ts);
+			for (j = 0; j < subslots; 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);
+}
+