move to libcommon-cs: gsm48_extract_mi(), gsm48_paging_extract_mi() -- TODO move to libfilter instead?

Change-Id: I00ca0caf8224de029f53f4dedb1146e3cf7650ec

1 files changed, 24 insertions, 0 deletions

diff --git a/openbsc/src/libcommon-cs/common_cs.c b/openbsc/src/libcommon-cs/common_cs.c
index 7a0530834..d94381b4c 100644
--- a/openbsc/src/libcommon-cs/common_cs.c
+++ b/openbsc/src/libcommon-cs/common_cs.c
@@ -115,6 +115,30 @@ struct msgb *gsm48_create_loc_upd_rej(uint8_t cause)
 	return msg;
 }
 
+int gsm48_extract_mi(uint8_t *classmark2_lv, int length, char *mi_string, uint8_t *mi_type)
+{
+	/* Check the size for the classmark */
+	if (length < 1 + *classmark2_lv)
+		return -1;
+
+	uint8_t *mi_lv = classmark2_lv + *classmark2_lv + 1;
+	if (length < 2 + *classmark2_lv + mi_lv[0])
+		return -2;
+
+	*mi_type = mi_lv[1] & GSM_MI_TYPE_MASK;
+	return gsm48_mi_to_string(mi_string, GSM48_MI_SIZE, mi_lv+1, *mi_lv);
+}
+
+int gsm48_paging_extract_mi(struct gsm48_pag_resp *resp, int length,
+			    char *mi_string, uint8_t *mi_type)
+{
+	static const uint32_t classmark_offset =
+		offsetof(struct gsm48_pag_resp, classmark2);
+	uint8_t *classmark2_lv = (uint8_t *) &resp->classmark2;
+	return gsm48_extract_mi(classmark2_lv, length - classmark_offset,
+				mi_string, mi_type);
+}
+
 uint8_t sms_next_rp_msg_ref(uint8_t *next_rp_ref)
 {
 	const uint8_t rp_msg_ref = *next_rp_ref;