sms: Introduce a SMS queue that will be responsible for delivery

The SMSqueue will be responsible of sending to the user. It will
do so in a loop and will also try not to overload the BTS. This
means the throughput of SMS will be limited.

4 files changed, 103 insertions, 33 deletions

diff --git a/openbsc/src/Makefile.am b/openbsc/src/Makefile.am
index 2766d938c..4f3bf9e31 100644
--- a/openbsc/src/Makefile.am
+++ b/openbsc/src/Makefile.am
@@ -35,7 +35,7 @@ libvty_a_SOURCES = common_vty.c
 
 libmgcp_a_SOURCES = mgcp/mgcp_protocol.c mgcp/mgcp_network.c mgcp/mgcp_vty.c
 
-bsc_hack_SOURCES = bsc_hack.c bsc_init.c bsc_vty.c vty_interface_layer3.c
+bsc_hack_SOURCES = bsc_hack.c bsc_init.c bsc_vty.c vty_interface_layer3.c sms_queue.c
 bsc_hack_LDADD = libmsc.a libbsc.a libvty.a libmsc.a \
 		-ldl -ldbi $(LIBCRYPT) $(LIBOSMOVTY_LIBS)
 
diff --git a/openbsc/src/bsc_hack.c b/openbsc/src/bsc_hack.c
index 4efc7821e..2b0af2e9a 100644
--- a/openbsc/src/bsc_hack.c
+++ b/openbsc/src/bsc_hack.c
@@ -274,6 +274,10 @@ int main(int argc, char **argv)
 	signal(SIGUSR2, &signal_handler);
 	signal(SIGPIPE, SIG_IGN);
 
+	/* start the SMS queue */
+	if (sms_queue_start(bsc_gsmnet, 5) != 0)
+		return -1;
+
 	if (daemonize) {
 		rc = osmo_daemonize();
 		if (rc < 0) {
diff --git a/openbsc/src/gsm_04_11.c b/openbsc/src/gsm_04_11.c
index 31bdf38c7..25fe467d6 100644
--- a/openbsc/src/gsm_04_11.c
+++ b/openbsc/src/gsm_04_11.c
@@ -101,7 +101,6 @@ static const struct value_string rp_cause_strs[] = {
 	{ 0, NULL }
 };
 
-static int gsm411_send_sms(struct gsm_subscriber_connection *conn, struct gsm_sms *sms);
 
 struct gsm_sms *sms_alloc(void)
 {
@@ -1047,7 +1046,7 @@ int gsm0411_rcv_sms(struct gsm_subscriber_connection *conn,
 /* Take a SMS in gsm_sms structure and send it through an already
  * existing lchan. We also assume that the caller ensured this lchan already
  * has a SAPI3 RLL connection! */
-static int gsm411_send_sms(struct gsm_subscriber_connection *conn, struct gsm_sms *sms)
+int gsm411_send_sms(struct gsm_subscriber_connection *conn, struct gsm_sms *sms)
 {
 	struct msgb *msg = gsm411_msgb_alloc();
 	struct gsm_trans *trans;
@@ -1174,32 +1173,6 @@ int gsm411_send_sms_subscr(struct gsm_subscriber *subscr,
 	return 0;
 }
 
-static int subscr_sig_cb(unsigned int subsys, unsigned int signal,
-			 void *handler_data, void *signal_data)
-{
-	struct gsm_subscriber *subscr;
-	struct gsm_subscriber_connection *conn;
-	struct gsm_sms *sms;
-
-	switch (signal) {
-	case S_SUBSCR_ATTACHED:
-		/* A subscriber has attached. Check if there are
-		 * any pending SMS for him to be delivered */
-		subscr = signal_data;
-		conn = connection_for_subscr(subscr);
-		if (!conn)
-			break;
-		sms = db_sms_get_unsent_for_subscr(subscr);
-		if (!sms)
-			break;
-		gsm411_send_sms(conn, sms);
-		break;
-	default:
-		break;
-	}
-	return 0;
-}
-
 void _gsm411_sms_trans_free(struct gsm_trans *trans)
 {
 	if (trans->sms.sms) {
@@ -1233,7 +1206,3 @@ void gsm411_sapi_n_reject(struct gsm_subscriber_connection *conn)
 	gsm411_release_conn(conn);
 }
 
-static __attribute__((constructor)) void on_dso_load_sms(void)
-{
-	register_signal_handler(SS_SUBSCR, subscr_sig_cb, NULL);
-}
diff --git a/openbsc/src/sms_queue.c b/openbsc/src/sms_queue.c
new file mode 100644
index 000000000..f61cf6326
--- /dev/null
+++ b/openbsc/src/sms_queue.c
@@ -0,0 +1,97 @@
+/* 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 General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+/**
+ * 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/signal.h>
+
+#include <osmocore/talloc.h>
+
+
+struct gsm_sms_queue {
+	struct gsm_network *network;
+	int max_pending;
+	int pending;
+};
+
+
+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;
+	}
+
+	network->sms_queue = sms;
+	sms->network = network;
+	sms->max_pending = max_pending;
+
+	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 __attribute__((constructor)) void on_dso_load_sms(void)
+{
+	register_signal_handler(SS_SUBSCR, sms_subscr_cb, NULL);
+}