sms: Add a way to always route SMS through SMPP systems

default-route would only be looked at after there has been
no subscriber in the local database. Depending on the setup
this is not what one wants. This has been discussed at the
OsmoDevCon and there have been hacks in some branches. Let's
introduce a VTY command to select if SMPP should be consulted
first and then fallback to the current behavior.

openbsc/src/libmsc/gsm_04_11.c

@@ -280,6 +280,27 @@ int sms_route_mt_sms(struct gsm_subscriber_connection *conn, struct msgb *msg,
 {
 	int rc;
 
+#ifdef BUILD_SMPP
+	/*
+	 * Route through SMPP first before going to the local database. In case
+	 * of a unroutable message and no local subscriber, SMPP will be tried
+	 * twice. In case of an unknown subscriber continue with the normal
+	 * delivery of the SMS.
+	 */
+	if (smpp_route_smpp_first(gsms, conn)) {
+		rc = smpp_try_deliver(gsms, conn);
+		if (rc == 1)
+			goto try_local;
+		if (rc < 0) {
+			rc = 21; /* cause 21: short message transfer rejected */
+			/* FIXME: handle the error somehow? */
+		}
+		return rc;
+	}
+
+try_local:
+#endif
+
 	/* determine gsms->receiver based on dialled number */
 	gsms->receiver = subscr_get_by_extension(conn->bts->network->subscr_group,
 						 gsms->dst.addr);

openbsc/src/libmsc/smpp_openbsc.c

@@ -539,6 +539,11 @@ static int deliver_to_esme(struct osmo_esme *esme, struct gsm_sms *sms,
 
 static struct smsc *g_smsc;
 
+int smpp_route_smpp_first(struct gsm_sms *sms, struct gsm_subscriber_connection *conn)
+{
+	return g_smsc->smpp_first;
+}
+
 int smpp_try_deliver(struct gsm_sms *sms, struct gsm_subscriber_connection *conn)
 {
 	struct osmo_esme *esme;

openbsc/src/libmsc/smpp_smsc.h

@@ -92,6 +92,7 @@ struct smsc {
 	uint16_t listen_port;
 	char system_id[SMPP_SYS_ID_LEN+1];
 	int accept_all;
+	int smpp_first;
 	struct osmo_smpp_acl *def_route;
 	void *priv;
 };
@@ -137,6 +138,8 @@ int smpp_determine_scheme(uint8_t dcs, uint8_t *data_coding, int *mode);
 struct gsm_sms;
 struct gsm_subscriber_connection;
 
+int smpp_route_smpp_first(struct gsm_sms *sms,
+			    struct gsm_subscriber_connection *conn);
 int smpp_try_deliver(struct gsm_sms *sms,
 			    struct gsm_subscriber_connection *conn);
 #endif

openbsc/src/libmsc/smpp_vty.c

@@ -58,6 +58,24 @@ DEFUN(cfg_smpp, cfg_smpp_cmd,
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_smpp_first, cfg_smpp_first_cmd,
+	"smpp-first",
+	"Try SMPP routes before the subscriber DB\n")
+{
+	struct smsc *smsc = smsc_from_vty(vty);
+	smsc->smpp_first = 1;
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_no_smpp_first, cfg_no_smpp_first_cmd,
+	"no smpp-first",
+	NO_STR "Try SMPP before routes before the subscriber DB\n")
+{
+	struct smsc *smsc = smsc_from_vty(vty);
+	smsc->smpp_first = 0;
+	return CMD_SUCCESS;
+}
+
 DEFUN(cfg_smpp_port, cfg_smpp_port_cmd,
 	"local-tcp-port <1-65535>",
 	"Set the local TCP port on which we listen for SMPP\n"
@@ -125,6 +143,8 @@ static int config_write_smpp(struct vty *vty)
 		vty_out(vty, " system-id %s%s", smsc->system_id, VTY_NEWLINE);
 	vty_out(vty, " policy %s%s",
 		smsc->accept_all ? "accept-all" : "closed", VTY_NEWLINE);
+	vty_out(vty, " %ssmpp-first%s",
+		smsc->smpp_first ? "" : "no ", VTY_NEWLINE);
 
 	return CMD_SUCCESS;
 }
@@ -512,6 +532,8 @@ int smpp_vty_init(void)
 	vty_install_default(SMPP_NODE);
 	install_element(CONFIG_NODE, &cfg_smpp_cmd);
 
+	install_element(SMPP_NODE, &cfg_smpp_first_cmd);
+	install_element(SMPP_NODE, &cfg_no_smpp_first_cmd);
 	install_element(SMPP_NODE, &cfg_smpp_port_cmd);
 	install_element(SMPP_NODE, &cfg_smpp_sys_id_cmd);
 	install_element(SMPP_NODE, &cfg_smpp_policy_cmd);

openbsc/tests/vty_test_runner.py

@@ -154,6 +154,28 @@ class TestVTYNITB(TestVTYGenericBSC):
         res = self.vty.command("list")
         return "smpp" in res
 
+    def testSmppFirst(self):
+        if not self.checkForSmpp():
+            return
+
+        # enable the configuration
+        self.vty.enable()
+        self.vty.command("configure terminal")
+        self.vty.command("smpp")
+
+        # check the default
+        res = self.vty.command("write terminal")
+        self.assert_(res.find(' no smpp-first') > 0)
+
+        self.vty.verify("smpp-first", [''])
+        res = self.vty.command("write terminal")
+        self.assert_(res.find(' smpp-first') > 0)
+        self.assertEquals(res.find('no smpp-first'), -1)
+
+        self.vty.verify("no smpp-first", [''])
+        res = self.vty.command("write terminal")
+        self.assert_(res.find('no smpp-first') > 0)
+
     def testVtyTree(self):
         self.vty.enable()
         self.assertTrue(self.vty.verify("configure terminal", ['']))