1 files changed, 69 insertions, 383 deletions

diff --git a/src/osmo-bsc/handover_logic.c b/src/osmo-bsc/handover_logic.c
index 0b0a8f448..5725213ef 100644
--- a/src/osmo-bsc/handover_logic.c
+++ b/src/osmo-bsc/handover_logic.c
@@ -33,7 +33,7 @@
 #include <osmocom/bsc/gsm_data.h>
 #include <osmocom/gsm/gsm_utils.h>
 #include <osmocom/bsc/abis_rsl.h>
-#include <osmocom/bsc/chan_alloc.h>
+#include <osmocom/bsc/lchan_select.h>
 #include <osmocom/bsc/signal.h>
 #include <osmocom/core/talloc.h>
 #include <osmocom/bsc/bsc_subscriber.h>
@@ -41,352 +41,88 @@
 #include <osmocom/bsc/handover.h>
 #include <osmocom/bsc/handover_cfg.h>
 #include <osmocom/bsc/bsc_subscr_conn_fsm.h>
+#include <osmocom/bsc/neighbor_ident.h>
+#include <osmocom/bsc/abis_nm.h>
+#include <osmocom/gsm/gsm0808.h>
+#include <osmocom/gsm/gsm0808_utils.h>
+
+const struct value_string handover_scope_names[] = {
+	{ HO_NO_HANDOVER, "HO-none" },
+	{ HO_INTRA_CELL, "AS" },
+	{ HO_INTRA_BSC, "HO-intraBSC" },
+	{ HO_INTER_BSC_OUT, "HO-interBSC-Out" },
+	{ HO_INTER_BSC_IN, "HO-interBSC-In" },
+	{ HO_SCOPE_ALL, "HO-any" },
+	{}
+};
+
+const struct value_string handover_result_names[] = {
+	{ HO_RESULT_OK, "Complete" },
+	{ HO_RESULT_FAIL_NO_CHANNEL, "Failure (no channel could be allocated)" },
+	{ HO_RESULT_FAIL_RR_HO_FAIL, "Failure (MS sent RR Handover Failure)" },
+	{ HO_RESULT_FAIL_TIMEOUT, "Failure (timeout)" },
+	{ HO_RESULT_CONN_RELEASE, "Connection released" },
+	{ HO_RESULT_ERROR, "Failure" },
+	{}
+};
 
-static LLIST_HEAD(bsc_handovers);
 static LLIST_HEAD(handover_decision_callbacks);
 
-static void handover_free(struct bsc_handover *ho)
-{
-	osmo_timer_del(&ho->T3103);
-	llist_del(&ho->list);
-	talloc_free(ho);
-}
-
-static struct bsc_handover *bsc_ho_by_new_lchan(struct gsm_lchan *new_lchan)
-{
-	struct bsc_handover *ho;
-
-	llist_for_each_entry(ho, &bsc_handovers, list) {
-		if (ho->new_lchan == new_lchan)
-			return ho;
-	}
-
-	return NULL;
-}
-
-static struct bsc_handover *bsc_ho_by_old_lchan(struct gsm_lchan *old_lchan)
-{
-	struct bsc_handover *ho;
-
-	llist_for_each_entry(ho, &bsc_handovers, list) {
-		if (ho->old_lchan == old_lchan)
-			return ho;
-	}
-
-	return NULL;
-}
-
-/*! Hand over the specified logical channel to the specified new BTS and possibly change the lchan type.
- * This is the main entry point for the actual handover algorithm, after the decision whether to initiate
- * HO to a specific BTS. To not change the lchan type, pass old_lchan->type. */
-int bsc_handover_start(enum hodec_id from_hodec_id, struct gsm_lchan *old_lchan, struct gsm_bts *new_bts,
-		       enum gsm_chan_t new_lchan_type)
-{
-	int rc;
-	struct gsm_subscriber_connection *conn;
-	struct bsc_handover *ho;
-	static uint8_t ho_ref = 0;
-	bool do_assignment;
-
-	OSMO_ASSERT(old_lchan);
-
-	/* don't attempt multiple handovers for the same lchan at
-	 * the same time */
-	if (bsc_ho_by_old_lchan(old_lchan))
-		return -EBUSY;
-
-	conn = old_lchan->conn;
-	if (!conn) {
-		LOGP(DHO, LOGL_ERROR, "Old lchan lacks connection data.\n");
-		return -ENOSPC;
-	}
-
-	if (!new_bts)
-		new_bts = old_lchan->ts->trx->bts;
-	OSMO_ASSERT(new_bts);
-
-	do_assignment = (new_bts == old_lchan->ts->trx->bts);
-
-	ho = talloc_zero(conn, struct bsc_handover);
-	if (!ho) {
-		LOGP(DHO, LOGL_FATAL, "Out of Memory\n");
-		return -ENOMEM;
-	}
-	ho->from_hodec_id = from_hodec_id;
-	ho->old_lchan = old_lchan;
-	ho->new_bts = new_bts;
-	ho->new_lchan_type = new_lchan_type;
-	ho->ho_ref = ho_ref++;
-	ho->inter_cell = !do_assignment;
-	ho->async = true;
-	llist_add(&ho->list, &bsc_handovers);
-
-	conn->ho = ho;
-	rc = osmo_fsm_inst_dispatch(conn->fi, GSCON_EV_HO_START, NULL);
-
-	if (rc < 0) {
-		LOGPHO(ho, LOGL_ERROR, "Failed to trigger handover, conn state does not allow it\n");
-		conn->ho = NULL;
-		talloc_free(ho);
-	}
-	return rc;
-}
-
-/*! Start actual handover. Call bsc_handover_start() instead; The only legal caller is the GSCON FSM in
- * bsc_subscr_conn_fsm.c. */
-int bsc_handover_start_gscon(struct gsm_subscriber_connection *conn)
-{
-	int rc;
-	struct gsm_network *network = conn->network;
-	struct bsc_handover *ho = conn->ho;
-	struct gsm_lchan *old_lchan;
-	struct gsm_lchan *new_lchan;
-
-	if (!ho) {
-		LOGP(DHO, LOGL_ERROR, "%s: Requested to start handover, but conn->ho is NULL\n",
-		     bsc_subscr_name(conn->bsub));
-		return -EINVAL;
-	}
-
-	OSMO_ASSERT(ho->old_lchan && ho->new_bts);
-
-	if (ho->old_lchan->conn != conn) {
-		LOGP(DHO, LOGL_ERROR,
-		     "%s: Requested to start handover, but the lchan does not belong to this conn\n",
-		     bsc_subscr_name(conn->bsub));
-		return -EINVAL;
-	}
-
-	rate_ctr_inc(&network->bsc_ctrs->ctr[BSC_CTR_HANDOVER_ATTEMPTED]);
-
-	ho->new_lchan = lchan_alloc(ho->new_bts, ho->new_lchan_type, 0);
-	if (!ho->new_lchan) {
-		LOGP(DHO, LOGL_NOTICE, "No free channel for %s\n", gsm_lchant_name(ho->new_lchan_type));
-		rate_ctr_inc(&network->bsc_ctrs->ctr[BSC_CTR_HANDOVER_NO_CHANNEL]);
-		return -ENOSPC;
-	}
-
-	LOGPHO(ho, LOGL_INFO, "Triggering %s\n", ho->inter_cell? "Handover" : "Assignment");
-
-	/* copy some parameters from old lchan */
-	old_lchan = ho->old_lchan;
-	new_lchan = ho->new_lchan;
-	memcpy(&new_lchan->encr, &old_lchan->encr, sizeof(new_lchan->encr));
-	if (!ho->inter_cell) {
-		new_lchan->ms_power = old_lchan->ms_power;
-		new_lchan->rqd_ta = old_lchan->rqd_ta;
-	} else {
-		new_lchan->ms_power =
-			ms_pwr_ctl_lvl(ho->new_bts->band, ho->new_bts->ms_max_power);
-		/* FIXME: do we have a better idea of the timing advance? */
-		//new_lchan->rqd_ta = old_lchan->rqd_ta;
-	}
-	new_lchan->bs_power = old_lchan->bs_power;
-	new_lchan->rsl_cmode = old_lchan->rsl_cmode;
-	new_lchan->tch_mode = old_lchan->tch_mode;
-	memcpy(&new_lchan->mr_ms_lv, &old_lchan->mr_ms_lv, sizeof(new_lchan->mr_ms_lv));
-	memcpy(&new_lchan->mr_bts_lv, &old_lchan->mr_bts_lv, sizeof(new_lchan->mr_bts_lv));
-
-	new_lchan->conn = conn;
-
-	rc = rsl_chan_activate_lchan(new_lchan,
-				     ho->async ? RSL_ACT_INTER_ASYNC : RSL_ACT_INTER_SYNC,
-				     ho->ho_ref);
-	if (rc < 0) {
-		LOGPHO(ho, LOGL_INFO, "%s Failure: activate lchan rc = %d\n",
-		       ho->inter_cell? "Handover" : "Assignment", rc);
-		lchan_free(new_lchan);
-		ho->new_lchan = NULL;
-		bsc_clear_handover(conn, 0);
-		return rc;
-	}
-
-	rsl_lchan_set_state(new_lchan, LCHAN_S_ACT_REQ);
-	/* we continue in the SS_LCHAN handler / ho_chan_activ_ack */
-
-	return 0;
-}
-
-/* clear any operation for this connection */
-void bsc_clear_handover(struct gsm_subscriber_connection *conn, int free_lchan)
-{
-	struct bsc_handover *ho = conn->ho;
-
-	if (!ho)
-		return;
-
-	if (ho->new_lchan) {
-		ho->new_lchan->conn = NULL;
-		if (free_lchan)
-			lchan_release(ho->new_lchan, 0, RSL_REL_LOCAL_END);
-		ho->new_lchan = NULL;
-	}
-
-	handover_free(ho);
-	conn->ho = NULL;
-}
-
-/* T3103 expired: Handover has failed without HO COMPLETE or HO FAIL */
-static void ho_T3103_cb(void *_ho)
-{
-	struct bsc_handover *ho = _ho;
-	struct gsm_network *net = ho->new_lchan->ts->trx->bts->network;
-
-	DEBUGP(DHO, "HO T3103 expired\n");
-	rate_ctr_inc(&net->bsc_ctrs->ctr[BSC_CTR_HANDOVER_TIMEOUT]);
-
-	/* Inform the GSCON FSM about the timed out handover */
-	osmo_fsm_inst_dispatch(ho->old_lchan->conn->fi, GSCON_EV_HO_TIMEOUT, NULL);
-
-	bsc_clear_handover(ho->old_lchan->conn, 1);
-}
-
-/* RSL has acknowledged activation of the new lchan */
-static int ho_chan_activ_ack(struct gsm_lchan *new_lchan)
+void handover_decision_callbacks_register(struct handover_decision_callbacks *hdc)
 {
-	struct bsc_handover *ho;
-
-	/* we need to check if this channel activation is related to
-	 * a handover at all (and if, which particular handover) */
-	ho = bsc_ho_by_new_lchan(new_lchan);
-	if (!ho)
-		return -ENODEV;
-
-	LOGPHO(ho, LOGL_INFO, "Channel Activate Ack, send %s COMMAND\n", ho->inter_cell? "HANDOVER" : "ASSIGNMENT");
-
-	/* we can now send the 04.08 HANDOVER COMMAND to the MS
-	 * using the old lchan */
-
-	gsm48_send_ho_cmd(ho->old_lchan, new_lchan, new_lchan->ms_power, ho->ho_ref);
-
-	/* start T3103.  We can continue either with T3103 expiration,
-	 * 04.08 HANDOVER COMPLETE or 04.08 HANDOVER FAIL */
-	osmo_timer_setup(&ho->T3103, ho_T3103_cb, ho);
-	osmo_timer_schedule(&ho->T3103, 10, 0);
-
-	/* create a RTP connection */
-	if (is_ipaccess_bts(new_lchan->ts->trx->bts))
-		rsl_ipacc_crcx(new_lchan);
-
-	return 0;
+	llist_add_tail(&hdc->entry, &handover_decision_callbacks);
 }
 
-/* RSL has not acknowledged activation of the new lchan */
-static int ho_chan_activ_nack(struct gsm_lchan *new_lchan)
+struct handover_decision_callbacks *handover_decision_callbacks_get(int hodec_id)
 {
-	struct bsc_handover *ho;
 	struct handover_decision_callbacks *hdc;
-
-	ho = bsc_ho_by_new_lchan(new_lchan);
-	if (!ho) {
-		/* This lchan is not involved in a handover. */
-		return 0;
-	}
-
-	hdc = handover_decision_callbacks_get(ho->from_hodec_id);
-	if (hdc && hdc->on_ho_chan_activ_nack)
-		hdc->on_ho_chan_activ_nack(ho);
-
-	bsc_clear_handover(new_lchan->conn, 0);
-	return 0;
-}
-
-/* GSM 04.08 HANDOVER COMPLETE has been received on new channel */
-static int ho_gsm48_ho_compl(struct gsm_lchan *new_lchan)
-{
-	struct gsm_network *net;
-	struct bsc_handover *ho;
-
-	ho = bsc_ho_by_new_lchan(new_lchan);
-	if (!ho) {
-		LOGP(DHO, LOGL_ERROR, "unable to find HO record\n");
-		return -ENODEV;
+	llist_for_each_entry(hdc, &handover_decision_callbacks, entry) {
+		if (hdc->hodec_id == hodec_id)
+			return hdc;
 	}
-
-	net = new_lchan->ts->trx->bts->network;
-
-	LOGPHO(ho, LOGL_INFO, "%s Complete\n", ho->inter_cell ? "Handover" : "Assignment");
-
-	rate_ctr_inc(&net->bsc_ctrs->ctr[BSC_CTR_HANDOVER_COMPLETED]);
-
-	osmo_timer_del(&ho->T3103);
-
-	/* Replace the ho lchan with the primary one */
-	if (ho->old_lchan != new_lchan->conn->lchan)
-		LOGPHO(ho, LOGL_ERROR, "Primary lchan changed during handover.\n");
-
-	if (new_lchan->conn->ho != ho)
-		LOGPHO(ho, LOGL_ERROR, "Handover channel changed during this handover.\n");
-
-	new_lchan->conn->lchan = new_lchan;
-	ho->old_lchan->conn = NULL;
-
-	lchan_release(ho->old_lchan, 0, RSL_REL_LOCAL_END);
-
-	handover_free(ho);
-	new_lchan->conn->ho = NULL;
-
-	/* Inform the GSCON FSM that the handover is complete */
-	osmo_fsm_inst_dispatch(new_lchan->conn->fi, GSCON_EV_HO_COMPL, NULL);
-	return 0;
+	return NULL;
 }
 
-/* GSM 04.08 HANDOVER FAIL has been received */
-static int ho_gsm48_ho_fail(struct gsm_lchan *old_lchan)
+static void ho_meas_rep(struct gsm_meas_rep *mr)
 {
-	struct gsm_network *net = old_lchan->ts->trx->bts->network;
-	struct bsc_handover *ho;
 	struct handover_decision_callbacks *hdc;
+	enum hodec_id hodec_id = ho_get_algorithm(mr->lchan->ts->trx->bts->ho);
 
-	ho = bsc_ho_by_old_lchan(old_lchan);
-	if (!ho) {
-		LOGP(DHO, LOGL_ERROR, "unable to find HO record\n");
-		return -ENODEV;
-	}
-
-	hdc = handover_decision_callbacks_get(ho->from_hodec_id);
-	if (hdc && hdc->on_ho_failure)
-		hdc->on_ho_failure(ho);
-
-	rate_ctr_inc(&net->bsc_ctrs->ctr[BSC_CTR_HANDOVER_FAILED]);
-
-	bsc_clear_handover(ho->new_lchan->conn, 1);
-
-	/* Inform the GSCON FSM that the handover failed */
-	osmo_fsm_inst_dispatch(old_lchan->conn->fi, GSCON_EV_HO_FAIL, NULL);
-	return 0;
+	hdc = handover_decision_callbacks_get(hodec_id);
+	if (!hdc || !hdc->on_measurement_report)
+		return;
+	hdc->on_measurement_report(mr);
 }
 
-/* GSM 08.58 HANDOVER DETECT has been received */
-static int ho_rsl_detect(struct gsm_lchan *new_lchan)
+/* Count ongoing handovers within the given BTS.
+ * ho_scopes is an OR'd combination of enum handover_scope values to include in the count. */
+int bts_handover_count(struct gsm_bts *bts, int ho_scopes)
 {
-	struct bsc_handover *ho;
+	struct gsm_bts_trx *trx;
+	int count = 0;
 
-	ho = bsc_ho_by_new_lchan(new_lchan);
-	if (!ho) {
-		LOGP(DHO, LOGL_ERROR, "unable to find HO record\n");
-		return -ENODEV;
+	llist_for_each_entry(trx, &bts->trx_list, list) {
+		int i;
+		for (i = 0; i < ARRAY_SIZE(trx->ts); i++) {
+			struct gsm_bts_trx_ts *ts = &trx->ts[i];
+			struct gsm_lchan *lchan;
+
+			/* skip administratively deactivated timeslots */
+			if (!nm_is_running(&ts->mo.nm_state))
+				continue;
+
+			ts_for_each_lchan(lchan, ts) {
+				if (!lchan->conn)
+					continue;
+				if (!lchan->conn->ho.fi)
+					continue;
+				if (lchan->conn->ho.scope & ho_scopes)
+					count++;
+			}
+		}
 	}
 
-	LOGPHO(ho, LOGL_DEBUG, "Handover RACH detected\n");
-
-	/* This is just for logging on the DHO category. The actual MGCP switchover happens in
-	 * osmo_bsc_mgcp.c by receiving the same S_LCHAN_HANDOVER_DETECT signal.
-	 * (Calling mgcp_handover() directly currently breaks linking in utils/...) */
-
-	return 0;
-}
-
-static int ho_meas_rep(struct gsm_meas_rep *mr)
-{
-	struct handover_decision_callbacks *hdc;
-	enum hodec_id hodec_id = ho_get_algorithm(mr->lchan->ts->trx->bts->ho);
-
-	hdc = handover_decision_callbacks_get(hodec_id);
-	if (!hdc || !hdc->on_measurement_report)
-		return 0;
-	hdc->on_measurement_report(mr);
-	return 0;
+	return count;
 }
 
 struct gsm_bts *bts_by_neighbor_ident(const struct gsm_network *net,
@@ -440,73 +176,23 @@ static int ho_logic_sig_cb(unsigned int subsys, unsigned int signal,
 	lchan_data = signal_data;
 	switch (subsys) {
 	case SS_LCHAN:
+		OSMO_ASSERT(lchan_data);
 		lchan = lchan_data->lchan;
+		OSMO_ASSERT(lchan);
+
 		switch (signal) {
-		case S_LCHAN_ACTIVATE_ACK:
-			return ho_chan_activ_ack(lchan);
-		case S_LCHAN_ACTIVATE_NACK:
-			return ho_chan_activ_nack(lchan);
-		case S_LCHAN_HANDOVER_DETECT:
-			return ho_rsl_detect(lchan);
-		case S_LCHAN_HANDOVER_COMPL:
-			return ho_gsm48_ho_compl(lchan);
-		case S_LCHAN_HANDOVER_FAIL:
-			return ho_gsm48_ho_fail(lchan);
 		case S_LCHAN_MEAS_REP:
-			return ho_meas_rep(lchan_data->mr);
+			ho_meas_rep(lchan_data->mr);
+			break;
 		}
-		break;
+
 	default:
 		break;
 	}
-
 	return 0;
 }
 
-/* Return the old lchan or NULL. This is meant for audio handling */
-struct gsm_lchan *bsc_handover_pending(struct gsm_lchan *new_lchan)
-{
-	struct bsc_handover *ho;
-	ho = bsc_ho_by_new_lchan(new_lchan);
-	if (!ho)
-		return NULL;
-	return ho->old_lchan;
-}
-
 static __attribute__((constructor)) void on_dso_load_ho_logic(void)
 {
 	osmo_signal_register_handler(SS_LCHAN, ho_logic_sig_cb, NULL);
 }
-
-/* Count number of currently ongoing handovers
- * inter_cell: if true, count only handovers between two cells. If false, count only handovers within one
- * cell. */
-int bsc_ho_count(struct gsm_bts *bts, bool inter_cell)
-{
-	struct bsc_handover *ho;
-	int count = 0;
-
-	llist_for_each_entry(ho, &bsc_handovers, list) {
-		if (ho->inter_cell != inter_cell)
-			continue;
-		if (ho->new_lchan->ts->trx->bts == bts)
-			count++;
-	}
-
-	return count;
-}
-
-void handover_decision_callbacks_register(struct handover_decision_callbacks *hdc)
-{
-	llist_add_tail(&hdc->entry, &handover_decision_callbacks);
-}
-
-struct handover_decision_callbacks *handover_decision_callbacks_get(int hodec_id)
-{
-	struct handover_decision_callbacks *hdc;
-	llist_for_each_entry(hdc, &handover_decision_callbacks, entry) {
-		if (hdc->hodec_id == hodec_id)
-			return hdc;
-	}
-	return NULL;
-}