[PATCH 3/4] SS: add Return Error component

[Max]

Signed-off-by: Max <max.suraev at fairwaves.co>
---
 openbsc/include/openbsc/gsm_04_80.h |  4 ++++
 openbsc/src/libmsc/gsm_04_80.c      | 36 ++++++++++++++++++++++++++++++++++--
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/openbsc/include/openbsc/gsm_04_80.h b/openbsc/include/openbsc/gsm_04_80.h
index 7139f95..20ec3ab 100644
--- a/openbsc/include/openbsc/gsm_04_80.h
+++ b/openbsc/include/openbsc/gsm_04_80.h
@@ -39,6 +39,10 @@ int gsm0480_send_ss_reject(struct gsm_subscriber_connection *conn,
 			   const struct ss_request *request,
 			   uint8_t problem_category,
 			   uint8_t problem_code);
+int gsm0480_send_ss_return_error(struct gsm_subscriber_connection *conn,
+				 const struct ss_request *req,
+				 uint8_t error_code,
+				 struct msgb *parameters);
 
 int gsm0480_send_ussdNotify(struct gsm_subscriber_connection *conn, int level, const char *text);
 int gsm0480_send_releaseComplete(struct gsm_subscriber_connection *conn);
diff --git a/openbsc/src/libmsc/gsm_04_80.c b/openbsc/src/libmsc/gsm_04_80.c
index b20521a..82b5623 100644
--- a/openbsc/src/libmsc/gsm_04_80.c
+++ b/openbsc/src/libmsc/gsm_04_80.c
@@ -91,8 +91,8 @@ int gsm0480_send_ussd_response(struct gsm_subscriber_connection *conn,
 
 /* Send response to a mobile-originated Invoke */
 int gsm0480_send_ss_return_result(struct gsm_subscriber_connection *conn,
-                                  const struct ss_request *req,
-                                  struct msgb *msg)
+				  const struct ss_request *req,
+				  struct msgb *msg)
 {
 	struct gsm48_hdr *gh;
 
@@ -149,6 +149,38 @@ int gsm0480_send_ss_reject(struct gsm_subscriber_connection *conn,
 	return gsm0808_submit_dtap(conn, msg, 0, 0);
 }
 
+int gsm0480_send_ss_return_error(struct gsm_subscriber_connection *conn,
+				 const struct ss_request *req,
+				 uint8_t error_code,
+				 struct msgb *parameters)
+{
+	struct msgb *msg = parameters;
+	struct gsm48_hdr *gh;
+
+	if(!msg)
+		msg = gsm48_msgb_alloc();
+
+	/* Pre-pend the error code */
+	msgb_push_TLV1(msg, GSM_0480_ERROR_CODE_TAG, error_code);
+
+	/* Before it insert the invoke ID */
+	msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, req->invoke_id);
+
+	/* Wrap this up as a Reject component */
+	msgb_wrap_with_TL(msg, GSM0480_CTYPE_RETURN_ERROR);
+
+	/* Wrap the component in a Facility message */
+	msgb_wrap_with_TL(msg, GSM0480_IE_FACILITY);
+
+	/* And finally pre-pend the L3 header */
+	gh = (struct gsm48_hdr *) msgb_push(msg, sizeof(*gh));
+	gh->proto_discr = GSM48_PDISC_NC_SS;
+	gh->proto_discr |= req->transaction_id | (1<<7);  /* TI direction = 1 */
+	gh->msg_type = GSM0480_MTYPE_RELEASE_COMPLETE;
+
+	return gsm0808_submit_dtap(conn, msg, 0, 0);
+}
+
 int gsm0480_send_ussdNotify(struct gsm_subscriber_connection *conn, int level, const char *text)
 {
 	struct gsm48_hdr *gh;
-- 
2.1.4