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-rw-r--r--src/libmsc/sms_queue.c479
1 files changed, 479 insertions, 0 deletions
diff --git a/src/libmsc/sms_queue.c b/src/libmsc/sms_queue.c
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+++ b/src/libmsc/sms_queue.c
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+/* 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 <osmocore/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 timer_list resend_pending;
+ struct 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 int sms_subscriber_is_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 1;
+ }
+
+ return 0;
+}
+
+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(DSMS, LOGL_DEBUG,
+ "Scheduling resend of SMS %llu.\n", pending->sms_id);
+
+ pending->resend = 1;
+
+ smsq = pending->subscr->net->sms_queue;
+ if (bsc_timer_pending(&smsq->resend_pending))
+ return;
+
+ bsc_schedule_timer(&smsq->resend_pending, 1, 0);
+}
+
+static void sms_pending_failed(struct gsm_sms_pending *pending, int paging_error)
+{
+ struct gsm_sms_queue *smsq;
+
+ LOGP(DSMS, LOGL_NOTICE, "Sending SMS %llu failed %d times.\n",
+ pending->sms_id, pending->failed_attempts);
+
+ smsq = pending->subscr->net->sms_queue;
+ if (++pending->failed_attempts < smsq->max_fail)
+ return sms_pending_resend(pending);
+
+ if (paging_error) {
+ LOGP(DSMS, LOGL_NOTICE,
+ "Subscriber %llu is not reachable. Setting LAC=0.\n", pending->subscr->id);
+ pending->subscr->lac = GSM_LAC_RESERVED_DETACHED;
+ db_sync_subscriber(pending->subscr);
+
+ /* Workaround a failing sync */
+ db_subscriber_update(pending->subscr);
+ }
+
+ 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(DSMS, LOGL_NOTICE, "Attempting to send %d SMS\n", attempts);
+
+ do {
+ struct gsm_sms_pending *pending;
+ struct gsm_sms *sms;
+
+
+ sms = take_next_sms(smsq);
+ if (!sms)
+ break;
+
+ rounds += 1;
+
+ /*
+ * 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) {
+ sms_free(sms);
+ break;
+ }
+
+ /* no need to send a pending sms */
+ if (sms_is_in_pending(smsq, sms)) {
+ LOGP(DSMS, 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(DSMS, 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(DSMS, 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(DSMS, LOGL_DEBUG, "SMSqueue added %d messages in %d rounds\n", attempted, rounds);
+}
+
+/*
+ * Kick off the queue again.
+ */
+int sms_queue_trigger(struct gsm_sms_queue *smsq)
+{
+ if (bsc_timer_pending(&smsq->push_queue))
+ return 0;
+
+ bsc_schedule_timer(&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;
+ }
+
+ register_signal_handler(SS_SUBSCR, sms_subscr_cb, network);
+ register_signal_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;
+ sms->push_queue.data = sms;
+ sms->push_queue.cb = sms_submit_pending;
+ sms->resend_pending.data = sms;
+ sms->resend_pending.cb = sms_resend_pending;
+
+ sms_submit_pending(sms);
+
+ return 0;
+}
+
+static int sub_ready_for_sm(struct gsm_subscriber *subscr)
+{
+ struct gsm_subscriber_connection *conn;
+ struct gsm_sms *sms;
+
+ /* A subscriber has attached. Check if there are
+ * any pending SMS for him to be delivered */
+ conn = connection_for_subscr(subscr);
+ if (!conn)
+ return -1;
+ 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(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;
+
+ /* We got a new SMS and maybe should launch the queue again. */
+ if (signal == S_SMS_SUBMITTED || signal == S_SMS_SMMA) {
+ 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:
+ /*
+ * Create place for a new SMS but keep the pending data
+ * so we will not attempt to send the SMS for this subscriber
+ * as we still have an open channel and will attempt to submit
+ * SMS to it anyway.
+ */
+ network->sms_queue->pending -= 1;
+ sms_submit_pending(network->sms_queue);
+ sms_pending_free(pending);
+ 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(DSMS, LOGL_ERROR, "Unhandled result: %d\n",
+ sig_sms->paging_result);
+ }
+ break;
+ default:
+ LOGP(DSMS, 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(DSMS, 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(DSMS, 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(DSMS, LOGL_NOTICE,
+ "SMSqueue clearing for sub %llu\n", pending->subscr->id);
+ sms_pending_free(pending);
+ }
+
+ smsq->pending = 0;
+ return 0;
+}