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osmo-msc/src/libmsc/sms_queue.c

583 lines
16 KiB

/* 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 <limits.h>
#include <osmocom/msc/sms_queue.h>
#include <osmocom/msc/db.h>
#include <osmocom/msc/debug.h>
#include <osmocom/msc/gsm_data.h>
#include <osmocom/msc/gsm_04_11.h>
#include <osmocom/msc/gsm_subscriber.h>
#include <osmocom/msc/signal.h>
#include <osmocom/msc/vlr.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 vlr_subscr *vsub;
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;
char last_msisdn[VLR_MSISDN_LENGTH+1];
};
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,
unsigned long long sms_id)
{
struct gsm_sms_pending *pending;
llist_for_each_entry(pending, &smsq->pending_sms, entry) {
if (pending->sms_id == sms_id)
return pending;
}
return NULL;
}
int sms_queue_sms_is_pending(struct gsm_sms_queue *smsq, unsigned long long sms_id)
{
return sms_find_pending(smsq, sms_id) != NULL;
}
static struct gsm_sms_pending *sms_subscriber_find_pending(
struct gsm_sms_queue *smsq,
struct vlr_subscr *vsub)
{
struct gsm_sms_pending *pending;
llist_for_each_entry(pending, &smsq->pending_sms, entry) {
if (pending->vsub == vsub)
return pending;
}
return NULL;
}
static int sms_subscriber_is_pending(struct gsm_sms_queue *smsq,
struct vlr_subscr *vsub)
{
return sms_subscriber_find_pending(smsq, vsub) != 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;
vlr_subscr_get(sms->receiver, VSUB_USE_SMS_PENDING);
pending->vsub = sms->receiver;
pending->sms_id = sms->id;
return pending;
}
static void sms_pending_free(struct gsm_sms_pending *pending)
{
vlr_subscr_put(pending->vsub, VSUB_USE_SMS_PENDING);
llist_del(&pending->entry);
talloc_free(pending);
}
static void sms_pending_resend(struct gsm_sms_pending *pending)
{
struct gsm_network *net = pending->vsub->vlr->user_ctx;
struct gsm_sms_queue *smsq;
LOGP(DLSMS, LOGL_DEBUG,
"Scheduling resend of SMS %llu.\n", pending->sms_id);
pending->resend = 1;
smsq = 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_network *net = pending->vsub->vlr->user_ctx;
struct gsm_sms_queue *smsq;
pending->failed_attempts++;
LOGP(DLSMS, LOGL_NOTICE, "Sending SMS %llu failed %d times.\n",
pending->sms_id, pending->failed_attempts);
smsq = net->sms_queue;
if (pending->failed_attempts < smsq->max_fail)
return sms_pending_resend(pending);
sms_pending_free(pending);
smsq->pending -= 1;
}
/*
* 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(smsq->network, sms->receiver, sms);
}
}
}
/* Find the next pending SMS by cycling through the recipients. We could also
* cycle through the pending SMS, but that might cause us to keep trying to
* send SMS to the same few subscribers repeatedly while not servicing other
* subscribers for a long time. By walking the list of recipient MSISDNs, we
* ensure that all subscribers get their fair time to receive SMS. */
struct gsm_sms *smsq_take_next_sms(struct gsm_network *net,
char *last_msisdn,
size_t last_msisdn_buflen)
{
struct gsm_sms *sms;
int wrapped = 0;
int sanity = 100;
char started_with_msisdn[last_msisdn_buflen];
OSMO_STRLCPY_ARRAY(started_with_msisdn, last_msisdn);
while (wrapped < 2 && (--sanity)) {
/* If we wrapped around and passed the first msisdn, we're
* through the entire SMS DB; end it. */
if (wrapped && strcmp(last_msisdn, started_with_msisdn) >= 0)
break;
sms = db_sms_get_next_unsent_rr_msisdn(net, last_msisdn, 9);
if (!sms) {
last_msisdn[0] = '\0';
wrapped++;
continue;
}
/* Whatever happens, next time around service another recipient
*/
osmo_strlcpy(last_msisdn, sms->dst.addr, last_msisdn_buflen);
/* Is the subscriber attached? If not, go to next SMS */
if (!sms->receiver || !sms->receiver->lu_complete) {
LOGP(DLSMS, LOGL_DEBUG,
"Subscriber %s%s is not attached, skipping SMS %llu\n",
sms->receiver ? "" : "MSISDN-",
sms->receiver ? vlr_subscr_msisdn_or_name(sms->receiver)
: sms->dst.addr, sms->id);
sms_free(sms);
continue;
}
return sms;
}
DEBUGP(DLSMS, "SMS queue: no SMS to be sent\n");
return NULL;
}
/**
* 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 = smsq_take_next_sms(smsq->network, smsq->last_msisdn,
sizeof(smsq->last_msisdn));
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_queue_sms_is_pending(smsq, sms->id)) {
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(smsq->network, 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 vlr_subscr *vsub)
{
struct gsm_network *net = vsub->vlr->user_ctx;
struct gsm_sms_queue *smsq = 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, vsub));
/* check for more messages for this subscriber */
sms = db_sms_get_unsent_for_subscr(vsub, UINT_MAX);
if (!sms)
goto no_pending_sms;
/* The sms should not be scheduled right now */
OSMO_ASSERT(!sms_queue_sms_is_pending(smsq, sms->id));
/* 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(smsq->network, sms->receiver, sms);
return;
no_pending_sms:
/* Try to send the SMS to avoid the queue being stuck */
sms_submit_pending(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 vlr_subscr *vsub)
{
struct gsm_sms *sms;
struct gsm_sms_pending *pending;
/*
* 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, vsub);
if (pending) {
LOGP(DMSC, LOGL_NOTICE,
"Pending paging while subscriber %llu attached.\n",
vsub->id);
return 0;
}
/* Now try to deliver any pending SMS to this sub */
sms = db_sms_get_unsent_for_subscr(vsub, UINT_MAX);
if (!sms)
return -1;
gsm411_send_sms(net, vsub, sms);
return 0;
}
static int sms_subscr_cb(unsigned int subsys, unsigned int signal,
void *handler_data, void *signal_data)
{
struct vlr_subscr *vsub = signal_data;
if (signal != S_SUBSCR_ATTACHED)
return 0;
/* this is readyForSM */
return sub_ready_for_sm(handler_data, vsub);
}
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 vlr_subscr *vsub;
/* 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->id);
if (!pending)
return 0;
switch (signal) {
case S_SMS_DELIVERED:
/* Remember the subscriber and clear the pending entry */
network->sms_queue->pending -= 1;
vsub = pending->vsub;
vlr_subscr_get(vsub, __func__);
db_sms_delete_sent_message_by_id(pending->sms_id);
sms_pending_free(pending);
/* Attempt to send another SMS to this subscriber */
sms_send_next(vsub);
vlr_subscr_put(vsub, __func__);
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_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);
}
/* While here, attempt to remove an expired SMS from the DB. */
db_sms_delete_oldest_expired_message();
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->vsub->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->vsub->id);
sms_pending_free(pending);
}
smsq->pending = 0;
return 0;
}