gsm0808: add gsm0808_create_sapi_reject_cause()

This is basically a successor of gsm0808_create_sapi_reject(), but
instead of hard-coding GSM0808_CAUSE_BSS_NOT_EQUIPPED, it allows
the caller to specify a cause value to be used.  The old function
is now deprecated and should not be used.

Change-Id: Iefe5484d0fa02d5722b628b1dc237d51d3fb1a9b
Related: OS#4728

5 files changed, 19 insertions, 4 deletions

diff --git a/TODO-RELEASE b/TODO-RELEASE
index 8ccfa491..3c2a15b8 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -7,3 +7,4 @@
 # If any interfaces have been added since the last public release: c:r:a + 1.
 # If any interfaces have been removed or changed since the last public release: c:r:0.
 #library	what			description / commit summary line
+libosmogsm	new API			gsm0808_create_sapi_reject_cause() with cause argument
diff --git a/include/osmocom/gsm/gsm0808.h b/include/osmocom/gsm/gsm0808.h
index 2a26fb5d..20137daf 100644
--- a/include/osmocom/gsm/gsm0808.h
+++ b/include/osmocom/gsm/gsm0808.h
@@ -60,7 +60,9 @@ struct msgb *gsm0808_create_cipher_reject_ext(enum gsm0808_cause_class class, ui
 struct msgb *gsm0808_create_classmark_request();
 struct msgb *gsm0808_create_classmark_update(const uint8_t *cm2, uint8_t cm2_len,
 					     const uint8_t *cm3, uint8_t cm3_len);
-struct msgb *gsm0808_create_sapi_reject(uint8_t link_id);
+struct msgb *gsm0808_create_sapi_reject_cause(uint8_t link_id, uint16_t cause);
+struct msgb *gsm0808_create_sapi_reject(uint8_t link_id)
+	OSMO_DEPRECATED("Use gsm0808_create_sapi_reject_cause() instead");
 struct msgb *gsm0808_create_ass(const struct gsm0808_channel_type *ct,
 				const uint16_t *cic,
 				const struct sockaddr_storage *ss,
diff --git a/src/gsm/gsm0808.c b/src/gsm/gsm0808.c
index a1d567df..85f5cfc9 100644
--- a/src/gsm/gsm0808.c
+++ b/src/gsm/gsm0808.c
@@ -444,8 +444,9 @@ struct msgb *gsm0808_create_classmark_update(const uint8_t *cm2, uint8_t cm2_len
 
 /*! Create BSSMAP SAPI N Reject message
  *  \param[in] link_id Link Identifier
+ *  \param[in] cause BSSAP Cause value (see 3GPP TS 48.008, section 3.2.2.5)
  *  \returns callee-allocated msgb with BSSMAP SAPI N Reject message */
-struct msgb *gsm0808_create_sapi_reject(uint8_t link_id)
+struct msgb *gsm0808_create_sapi_reject_cause(uint8_t link_id, uint16_t cause)
 {
 	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
 					       "bssmap: sapi 'n' reject");
@@ -454,13 +455,23 @@ struct msgb *gsm0808_create_sapi_reject(uint8_t link_id)
 
 	msgb_v_put(msg, BSS_MAP_MSG_SAPI_N_REJECT);
 	msgb_tv_put(msg, GSM0808_IE_DLCI, link_id);
-	gsm0808_enc_cause(msg, GSM0808_CAUSE_BSS_NOT_EQUIPPED);
+	gsm0808_enc_cause(msg, cause);
 
 	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));
 
 	return msg;
 }
 
+/*! Create BSSMAP SAPI N Reject message (with hard-coded cause "BSS not equipped").
+ *  DEPRECATED: use gsm0808_create_sapi_reject_cause() instead.
+ *  \param[in] link_id Link Identifier
+ *  \param[in] cause BSSAP Cause value (see 3GPP TS 48.008, section 3.2.2.5)
+ *  \returns callee-allocated msgb with BSSMAP SAPI N Reject message */
+struct msgb *gsm0808_create_sapi_reject(uint8_t link_id)
+{
+	return gsm0808_create_sapi_reject_cause(link_id, GSM0808_CAUSE_BSS_NOT_EQUIPPED);
+}
+
 /*! Create BSSMAP Assignment Request message, 3GPP TS 48.008 §3.2.1.1.
  *  This is identical to gsm0808_create_ass(), but adds KC and LCLS IEs.
  *  \param[in] ct Channel Type
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index 713ffe3e..4ece1079 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -190,6 +190,7 @@ gsm0808_create_lcls_conn_ctrl_ack;
 gsm0808_create_lcls_notification;
 gsm0808_create_reset;
 gsm0808_create_reset_ack;
+gsm0808_create_sapi_reject_cause;
 gsm0808_create_sapi_reject;
 gsm0808_create_handover_required;
 gsm0808_create_handover_required_reject;
diff --git a/tests/gsm0808/gsm0808_test.c b/tests/gsm0808/gsm0808_test.c
index 5c1a9313..dd2ffbe9 100644
--- a/tests/gsm0808/gsm0808_test.c
+++ b/tests/gsm0808/gsm0808_test.c
@@ -374,7 +374,7 @@ static void test_create_sapi_reject()
 	struct msgb *msg;
 
 	printf("Testing creating SAPI Reject\n");
-	msg = gsm0808_create_sapi_reject(3);
+	msg = gsm0808_create_sapi_reject_cause(3, GSM0808_CAUSE_BSS_NOT_EQUIPPED);
 	VERIFY(msg, res, ARRAY_SIZE(res));
 	msgb_free(msg);
 }