ussd: Send USSD on call setup on MSC errors
Send an USSD message to the mobile station requesting a connection
for a call or a SMS when the link to the MSC is down or in the
grace period.
The messages can be set (and this feature activated) by setting
bsc/missing-msc-text resp. msc/bsc-grace-text via the vty.
The generation of both messages has been tested manually.
Ticket: OW#957
diff --git a/openbsc/src/osmo-bsc/osmo_bsc_api.c b/openbsc/src/osmo-bsc/osmo_bsc_api.c
index df8c044..675bbb2 100644
--- a/openbsc/src/osmo-bsc/osmo_bsc_api.c
+++ b/openbsc/src/osmo-bsc/osmo_bsc_api.c
@@ -21,6 +21,8 @@
#include <openbsc/osmo_msc_data.h>
#include <openbsc/debug.h>
+#include <openbsc/gsm_04_80.h>
+
#include <osmocom/gsm/protocol/gsm_08_08.h>
#include <osmocom/gsm/gsm0808.h>
@@ -85,6 +87,47 @@
queue_msg_or_return(resp);
}
+static void bsc_send_ussd_notification(struct gsm_subscriber_connection *conn,
+ struct msgb *msg, const char *text)
+{
+ struct gsm48_hdr *gh;
+ int8_t pdisc;
+ uint8_t mtype;
+ int drop_message = 1;
+
+ if (!text)
+ return;
+
+ if (!msg || msgb_l3len(msg) < sizeof(*gh))
+ return;
+
+ gh = msgb_l3(msg);
+ pdisc = gh->proto_discr & 0x0f;
+ mtype = gh->msg_type & 0xbf;
+
+ /* Is CM service request? */
+ if (pdisc == GSM48_PDISC_MM && mtype == GSM48_MT_MM_CM_SERV_REQ) {
+ struct gsm48_service_request *cm;
+
+ cm = (struct gsm48_service_request *) &gh->data[0];
+
+ /* Is type SMS or call? */
+ if (cm->cm_service_type == GSM48_CMSERV_SMS)
+ drop_message = 0;
+ else if (cm->cm_service_type == GSM48_CMSERV_MO_CALL_PACKET)
+ drop_message = 0;
+ }
+
+ if (drop_message) {
+ LOGP(DMSC, LOGL_DEBUG, "Skipping (not sending) USSD message: '%s'\n", text);
+ return;
+ }
+
+ LOGP(DMSC, LOGL_INFO, "Sending USSD message: '%s'\n", text);
+ gsm0480_send_ussdNotify(conn, 1, text);
+ gsm0480_send_releaseComplete(conn);
+}
+
/*
* Instruct to reserve data for a new connectiom, create the complete
* layer three message, send it to open the connection.
@@ -100,6 +143,7 @@
msc = bsc_find_msc(conn, msg);
if (!msc) {
LOGP(DMSC, LOGL_ERROR, "Failed to find a MSC for a connection.\n");
+ bsc_send_ussd_notification(conn, msg, conn->bts->network->bsc_data->ussd_no_msc_txt);
return -1;
}
@@ -112,10 +156,22 @@
struct msgb *resp;
uint16_t network_code;
uint16_t country_code;
+ enum bsc_con ret;
/* allocate resource for a new connection */
- if (bsc_create_new_connection(conn, msc) != 0)
+ ret = bsc_create_new_connection(conn, msc);
+
+ if (ret != BSC_CON_SUCCESS) {
+ /* allocation has failed */
+ if (ret == BSC_CON_REJECT_NO_LINK)
+ bsc_send_ussd_notification(conn, msg, msc->ussd_msc_lost_txt);
+ else if (ret == BSC_CON_REJECT_RF_GRACE)
+ bsc_send_ussd_notification(conn, msg, msc->ussd_grace_txt);
+
return BSC_API_CONN_POL_REJECT;
+ }
+
+ /* check return value, if failed check msg for and send USSD */
network_code = get_network_code_for_msc(conn->sccp_con->msc);
country_code = get_country_code_for_msc(conn->sccp_con->msc);