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, 544 insertions, 0 deletions

diff --git a/src/libmsc/sms_queue.c b/src/libmsc/sms_queue.c
new file mode 100644
index 000000000..dc7f6e8c6
--- /dev/null
+++ b/src/libmsc/sms_queue.c
@@ -0,0 +1,544 @@
+/* SMS queue to continously attempt to deliver SMS */
+/*
+ * (C) 2010 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/>.
+ *
+ */
+
+/**
+ * The difficulty of such a queue is to send a lot of SMS without
+ * overloading the paging subsystem and the database and other users
+ * of the MSC. To make the best use we would need to know the number
+ * of pending paging requests, then throttle the number of SMS we
+ * want to send and such.
+ * We will start with a very simple SMS Queue and then try to speed
+ * things up by collecting data from other parts of the system.
+ */
+
+#include <openbsc/sms_queue.h>
+#include <openbsc/chan_alloc.h>
+#include <openbsc/db.h>
+#include <openbsc/debug.h>
+#include <openbsc/gsm_data.h>
+#include <openbsc/gsm_04_11.h>
+#include <openbsc/gsm_subscriber.h>
+#include <openbsc/signal.h>
+
+#include <osmocom/core/talloc.h>
+
+#include <osmocom/vty/vty.h>
+
+/*
+ * One pending SMS that we wait for.
+ */
+struct gsm_sms_pending {
+	struct llist_head entry;
+
+	struct gsm_subscriber *subscr;
+	unsigned long long sms_id;
+	int failed_attempts;
+	int resend;
+};
+
+struct gsm_sms_queue {
+	struct osmo_timer_list resend_pending;
+	struct osmo_timer_list push_queue;
+	struct gsm_network *network;
+	int max_fail;
+	int max_pending;
+	int pending;
+
+	struct llist_head pending_sms;
+	unsigned long long last_subscr_id;
+};
+
+static int sms_subscr_cb(unsigned int, unsigned int, void *, void *);
+static int sms_sms_cb(unsigned int, unsigned int, void *, void *);
+
+static struct gsm_sms_pending *sms_find_pending(struct gsm_sms_queue *smsq,
+						struct gsm_sms *sms)
+{
+	struct gsm_sms_pending *pending;
+
+	llist_for_each_entry(pending, &smsq->pending_sms, entry) {
+		if (pending->sms_id == sms->id)
+			return pending;
+	}
+
+	return NULL;
+}
+
+static int sms_is_in_pending(struct gsm_sms_queue *smsq, struct gsm_sms *sms)
+{
+	return sms_find_pending(smsq, sms) != NULL;
+}
+
+static struct gsm_sms_pending *sms_subscriber_find_pending(
+					struct gsm_sms_queue *smsq,
+					struct gsm_subscriber *subscr)
+{
+	struct gsm_sms_pending *pending;
+
+	llist_for_each_entry(pending, &smsq->pending_sms, entry) {
+		if (pending->subscr == subscr)
+			return pending;
+	}
+
+	return NULL;
+}
+
+static int sms_subscriber_is_pending(struct gsm_sms_queue *smsq,
+				     struct gsm_subscriber *subscr)
+{
+	return sms_subscriber_find_pending(smsq, subscr) != NULL;
+}
+
+static struct gsm_sms_pending *sms_pending_from(struct gsm_sms_queue *smsq,
+						struct gsm_sms *sms)
+{
+	struct gsm_sms_pending *pending;
+
+	pending = talloc_zero(smsq, struct gsm_sms_pending);
+	if (!pending)
+		return NULL;
+
+	pending->subscr = subscr_get(sms->receiver);
+	pending->sms_id = sms->id;
+	return pending;
+}
+
+static void sms_pending_free(struct gsm_sms_pending *pending)
+{
+	subscr_put(pending->subscr);
+	llist_del(&pending->entry);
+	talloc_free(pending);
+}
+
+static void sms_pending_resend(struct gsm_sms_pending *pending)
+{
+	struct gsm_sms_queue *smsq;
+	LOGP(DLSMS, LOGL_DEBUG,
+	     "Scheduling resend of SMS %llu.\n", pending->sms_id);
+
+	pending->resend = 1;
+
+	smsq = pending->subscr->group->net->sms_queue;
+	if (osmo_timer_pending(&smsq->resend_pending))
+		return;
+
+	osmo_timer_schedule(&smsq->resend_pending, 1, 0);
+}
+
+static void sms_pending_failed(struct gsm_sms_pending *pending, int paging_error)
+{
+	struct gsm_sms_queue *smsq;
+
+	LOGP(DLSMS, LOGL_NOTICE, "Sending SMS %llu failed %d times.\n",
+	     pending->sms_id, pending->failed_attempts);
+
+	smsq = pending->subscr->group->net->sms_queue;
+	if (++pending->failed_attempts < smsq->max_fail)
+		return sms_pending_resend(pending);
+
+	sms_pending_free(pending);
+	smsq->pending -= 1;
+	sms_queue_trigger(smsq);
+}
+
+/*
+ * Resend all SMS that are scheduled for a resend. This is done to
+ * avoid an immediate failure.
+ */
+static void sms_resend_pending(void *_data)
+{
+	struct gsm_sms_pending *pending, *tmp;
+	struct gsm_sms_queue *smsq = _data;
+
+	llist_for_each_entry_safe(pending, tmp, &smsq->pending_sms, entry) {
+		struct gsm_sms *sms;
+		if (!pending->resend)
+			continue;
+
+		sms = db_sms_get(smsq->network, pending->sms_id);
+
+		/* the sms is gone? Move to the next */
+		if (!sms) {
+			sms_pending_free(pending);
+			smsq->pending -= 1;
+			sms_queue_trigger(smsq);
+		} else {
+			pending->resend = 0;
+			gsm411_send_sms_subscr(sms->receiver, sms);
+		}
+	}
+}
+
+static struct gsm_sms *take_next_sms(struct gsm_sms_queue *smsq)
+{
+	struct gsm_sms *sms;
+
+	sms = db_sms_get_unsent_by_subscr(smsq->network, smsq->last_subscr_id, 10);
+	if (sms) {
+		smsq->last_subscr_id = sms->receiver->id + 1;
+		return sms;
+	}
+
+	/* need to wrap around */
+	smsq->last_subscr_id = 0;
+	sms = db_sms_get_unsent_by_subscr(smsq->network,
+					  smsq->last_subscr_id, 10);
+	if (sms)
+		smsq->last_subscr_id = sms->receiver->id + 1;
+	return sms;
+}
+
+/**
+ * I will submit up to max_pending - pending SMS to the
+ * subsystem.
+ */
+static void sms_submit_pending(void *_data)
+{
+	struct gsm_sms_queue *smsq = _data;
+	int attempts = smsq->max_pending - smsq->pending;
+	int initialized = 0;
+	unsigned long long first_sub = 0;
+	int attempted = 0, rounds = 0;
+
+	LOGP(DLSMS, LOGL_DEBUG, "Attempting to send %d SMS\n", attempts);
+
+	do {
+		struct gsm_sms_pending *pending;
+		struct gsm_sms *sms;
+
+
+		sms = take_next_sms(smsq);
+		if (!sms) {
+			LOGP(DLSMS, LOGL_DEBUG, "Sending SMS done (%d attempted)\n",
+			     attempted);
+			break;
+		}
+
+		rounds += 1;
+		LOGP(DLSMS, LOGL_DEBUG, "Sending SMS round %d\n", rounds);
+
+		/*
+		 * This code needs to detect a loop. It assumes that no SMS
+		 * will vanish during the time this is executed. We will remember
+		 * the id of the first GSM subscriber we see and then will
+		 * compare this. The Database code should make sure that we will
+		 * see all other subscribers first before seeing this one again.
+		 *
+		 * It is always scary to have an infinite loop like this.
+		 */
+		if (!initialized) {
+			first_sub = sms->receiver->id;
+			initialized = 1;
+		} else if (first_sub == sms->receiver->id) {
+			LOGP(DLSMS, LOGL_DEBUG, "Sending SMS done (loop) (%d attempted)\n",
+			     attempted);
+			sms_free(sms);
+			break;
+		}
+
+		/* no need to send a pending sms */
+		if (sms_is_in_pending(smsq, sms)) {
+			LOGP(DLSMS, LOGL_DEBUG,
+			     "SMSqueue with pending sms: %llu. Skipping\n", sms->id);
+			sms_free(sms);
+			continue;
+		}
+
+		/* no need to send a SMS with the same receiver */
+		if (sms_subscriber_is_pending(smsq, sms->receiver)) {
+			LOGP(DLSMS, LOGL_DEBUG,
+			     "SMSqueue with pending sub: %llu. Skipping\n", sms->receiver->id);
+			sms_free(sms);
+			continue;
+		}
+
+		pending = sms_pending_from(smsq, sms);
+		if (!pending) {
+			LOGP(DLSMS, LOGL_ERROR,
+			     "Failed to create pending SMS entry.\n");
+			sms_free(sms);
+			continue;
+		}
+
+		attempted += 1;
+		smsq->pending += 1;
+		llist_add_tail(&pending->entry, &smsq->pending_sms);
+		gsm411_send_sms_subscr(sms->receiver, sms);
+	} while (attempted < attempts && rounds < 1000);
+
+	LOGP(DLSMS, LOGL_DEBUG, "SMSqueue added %d messages in %d rounds\n", attempted, rounds);
+}
+
+/**
+ * Send the next SMS or trigger the queue
+ */
+static void sms_send_next(struct gsm_subscriber *subscr)
+{
+	struct gsm_sms_queue *smsq = subscr->group->net->sms_queue;
+	struct gsm_sms_pending *pending;
+	struct gsm_sms *sms;
+
+	/* the subscriber should not be in the queue */
+	OSMO_ASSERT(!sms_subscriber_is_pending(smsq, subscr));
+
+	/* check for more messages for this subscriber */
+	sms = db_sms_get_unsent_for_subscr(subscr);
+	if (!sms)
+		goto no_pending_sms;
+
+	/* No sms should be scheduled right now */
+	OSMO_ASSERT(!sms_is_in_pending(smsq, sms));
+
+	/* Remember that we deliver this SMS and send it */
+	pending = sms_pending_from(smsq, sms);
+	if (!pending) {
+		LOGP(DLSMS, LOGL_ERROR,
+			"Failed to create pending SMS entry.\n");
+		sms_free(sms);
+		goto no_pending_sms;
+	}
+
+	smsq->pending += 1;
+	llist_add_tail(&pending->entry, &smsq->pending_sms);
+	gsm411_send_sms_subscr(sms->receiver, sms);
+	return;
+
+no_pending_sms:
+	/* Try to send the SMS to avoid the queue being stuck */
+	sms_submit_pending(subscr->group->net->sms_queue);
+}
+
+/*
+ * Kick off the queue again.
+ */
+int sms_queue_trigger(struct gsm_sms_queue *smsq)
+{
+	LOGP(DLSMS, LOGL_DEBUG, "Triggering SMS queue\n");
+	if (osmo_timer_pending(&smsq->push_queue))
+		return 0;
+
+	osmo_timer_schedule(&smsq->push_queue, 1, 0);
+	return 0;
+}
+
+int sms_queue_start(struct gsm_network *network, int max_pending)
+{
+	struct gsm_sms_queue *sms = talloc_zero(network, struct gsm_sms_queue);
+	if (!sms) {
+		LOGP(DMSC, LOGL_ERROR, "Failed to create the SMS queue.\n");
+		return -1;
+	}
+
+	osmo_signal_register_handler(SS_SUBSCR, sms_subscr_cb, network);
+	osmo_signal_register_handler(SS_SMS, sms_sms_cb, network);
+
+	network->sms_queue = sms;
+	INIT_LLIST_HEAD(&sms->pending_sms);
+	sms->max_fail = 1;
+	sms->network = network;
+	sms->max_pending = max_pending;
+	osmo_timer_setup(&sms->push_queue, sms_submit_pending, sms);
+	osmo_timer_setup(&sms->resend_pending, sms_resend_pending, sms);
+
+	sms_submit_pending(sms);
+
+	return 0;
+}
+
+static int sub_ready_for_sm(struct gsm_network *net, struct gsm_subscriber *subscr)
+{
+	struct gsm_sms *sms;
+	struct gsm_sms_pending *pending;
+	struct gsm_subscriber_connection *conn;
+
+	/*
+	 * The code used to be very clever and tried to submit
+	 * a SMS during the Location Updating Request. This has
+	 * two issues:
+	 *   1.) The Phone might not be ready yet, e.g. the C155
+	 *       will not respond to the Submit when it is booting.
+	 *   2.) The queue is already trying to submit SMS to the
+	 *	 user and by not responding to the paging request
+	 *	 we will set the LAC back to 0. We would have to
+	 *	 stop the paging and move things over.
+	 *
+	 * We need to be careful in what we try here.
+	 */
+
+	/* check if we have pending requests */
+	pending = sms_subscriber_find_pending(net->sms_queue, subscr);
+	if (pending) {
+		LOGP(DMSC, LOGL_NOTICE,
+		     "Pending paging while subscriber %llu attached.\n",
+		      subscr->id);
+		return 0;
+	}
+
+	conn = connection_for_subscr(subscr);
+	if (!conn)
+		return -1;
+
+	/* Now try to deliver any pending SMS to this sub */
+	sms = db_sms_get_unsent_for_subscr(subscr);
+	if (!sms)
+		return -1;
+	gsm411_send_sms(conn, sms);
+	return 0;
+}
+
+static int sms_subscr_cb(unsigned int subsys, unsigned int signal,
+			 void *handler_data, void *signal_data)
+{
+	struct gsm_subscriber *subscr = signal_data;
+
+	if (signal != S_SUBSCR_ATTACHED)
+		return 0;
+
+	/* this is readyForSM */
+	return sub_ready_for_sm(handler_data, subscr);
+}
+
+static int sms_sms_cb(unsigned int subsys, unsigned int signal,
+		      void *handler_data, void *signal_data)
+{
+	struct gsm_network *network = handler_data;
+	struct sms_signal_data *sig_sms = signal_data;
+	struct gsm_sms_pending *pending;
+	struct gsm_subscriber *subscr;
+
+	/* We got a new SMS and maybe should launch the queue again. */
+	if (signal == S_SMS_SUBMITTED || signal == S_SMS_SMMA) {
+		/* TODO: For SMMA we might want to re-use the radio connection. */
+		sms_queue_trigger(network->sms_queue);
+		return 0;
+	}
+
+	if (!sig_sms->sms)
+		return -1;
+
+
+	/*
+	 * Find the entry of our queue. The SMS subsystem will submit
+	 * sms that are not in our control as we just have a channel
+	 * open anyway.
+	 */
+	pending = sms_find_pending(network->sms_queue, sig_sms->sms);
+	if (!pending)
+		return 0;
+
+	switch (signal) {
+	case S_SMS_DELIVERED:
+		/* Remember the subscriber and clear the pending entry */
+		network->sms_queue->pending -= 1;
+		subscr = subscr_get(pending->subscr);
+		sms_pending_free(pending);
+		/* Attempt to send another SMS to this subscriber */
+		sms_send_next(subscr);
+		subscr_put(subscr);
+		break;
+	case S_SMS_MEM_EXCEEDED:
+		network->sms_queue->pending -= 1;
+		sms_pending_free(pending);
+		sms_queue_trigger(network->sms_queue);
+		break;
+	case S_SMS_UNKNOWN_ERROR:
+		/*
+		 * There can be many reasons for this failure. E.g. the paging
+		 * timed out, the subscriber was not paged at all, or there was
+		 * a protocol error. The current strategy is to try sending the
+		 * next SMS for busy/oom and to retransmit when we have paged.
+		 *
+		 * When the paging expires three times we will disable the
+		 * subscriber. If we have some kind of other transmit error we
+		 * should flag the SMS as bad.
+		 */
+		switch (sig_sms->paging_result) {
+		case 0:
+			/* BAD SMS? */
+			db_sms_inc_deliver_attempts(sig_sms->sms);
+			sms_pending_failed(pending, 0);
+			break;
+		case GSM_PAGING_EXPIRED:
+			sms_pending_failed(pending, 1);
+			break;
+
+		case GSM_PAGING_OOM:
+		case GSM_PAGING_BUSY:
+			network->sms_queue->pending -= 1;
+			sms_pending_free(pending);
+			sms_queue_trigger(network->sms_queue);
+			break;
+		default:
+			LOGP(DLSMS, LOGL_ERROR, "Unhandled result: %d\n",
+			     sig_sms->paging_result);
+		}
+		break;
+	default:
+		LOGP(DLSMS, LOGL_ERROR, "Unhandled result: %d\n",
+		     sig_sms->paging_result);
+	}
+
+	return 0;
+}
+
+/* VTY helper functions */
+int sms_queue_stats(struct gsm_sms_queue *smsq, struct vty *vty)
+{
+	struct gsm_sms_pending *pending;
+
+	vty_out(vty, "SMSqueue with max_pending: %d pending: %d%s",
+		smsq->max_pending, smsq->pending, VTY_NEWLINE);
+
+	llist_for_each_entry(pending, &smsq->pending_sms, entry)
+		vty_out(vty, " SMS Pending for Subscriber: %llu SMS: %llu Failed: %d.%s",
+			pending->subscr->id, pending->sms_id,
+			pending->failed_attempts, VTY_NEWLINE);
+	return 0;
+}
+
+int sms_queue_set_max_pending(struct gsm_sms_queue *smsq, int max_pending)
+{
+	LOGP(DLSMS, LOGL_NOTICE, "SMSqueue old max: %d new: %d\n",
+	     smsq->max_pending, max_pending);
+	smsq->max_pending = max_pending;
+	return 0;
+}
+
+int sms_queue_set_max_failure(struct gsm_sms_queue *smsq, int max_fail)
+{
+	LOGP(DLSMS, LOGL_NOTICE, "SMSqueue max failure old: %d new: %d\n",
+	     smsq->max_fail, max_fail);
+	smsq->max_fail = max_fail;
+	return 0;
+}
+
+int sms_queue_clear(struct gsm_sms_queue *smsq)
+{
+	struct gsm_sms_pending *pending, *tmp;
+
+	llist_for_each_entry_safe(pending, tmp, &smsq->pending_sms, entry) {
+		LOGP(DLSMS, LOGL_NOTICE,
+		     "SMSqueue clearing for sub %llu\n", pending->subscr->id);
+		sms_pending_free(pending);
+	}
+
+	smsq->pending = 0;
+	return 0;
+}