corex: exported kemi function to test if user-agend header is set

- KSR.has_user_agent() - return 1 if User-Agent has value; -1 otherwise

src/modules/corex/corex_mod.c

@@ -751,7 +751,7 @@ static int w_via_add_xavp_params(sip_msg_t *msg, char *pflags, char *s2)
 }
 
 /**
- * 
+ *
  */
 static int ki_has_ruri_user(sip_msg_t *msg)
 {
@@ -773,6 +773,28 @@ static int ki_has_ruri_user(sip_msg_t *msg)
 	return -1;
 }
 
+/**
+ *
+ */
+static int ki_has_user_agent(sip_msg_t *msg)
+{
+	if(msg==NULL)
+		return -1;
+
+	if(msg->user_agent==NULL && ((parse_headers(msg, HDR_USERAGENT_F, 0)==-1)
+			|| (msg->user_agent==NULL)))
+	{
+		LM_DBG("no User-Agent header\n");
+		return -1;
+	}
+
+	if(msg->user_agent->body.s!=NULL && msg->user_agent->body.len>0) {
+		return 1;
+	}
+
+	return -1;
+}
+
 /**
  *
  */
@@ -838,6 +860,11 @@ static sr_kemi_t sr_kemi_corex_exports[] = {
 		{ SR_KEMIP_NONE, SR_KEMIP_NONE, SR_KEMIP_NONE,
 			SR_KEMIP_NONE, SR_KEMIP_NONE, SR_KEMIP_NONE }
 	},
+	{ str_init("corex"), str_init("has_user_agent"),
+		SR_KEMIP_INT, ki_has_user_agent,
+		{ SR_KEMIP_NONE, SR_KEMIP_NONE, SR_KEMIP_NONE,
+			SR_KEMIP_NONE, SR_KEMIP_NONE, SR_KEMIP_NONE }
+	},
 
 	{ {0, 0}, {0, 0}, 0, NULL, { 0, 0, 0, 0, 0, 0 } }
 };