--- libelwix/src/vars.c	2022/01/24 16:01:49	1.9.56.2
+++ libelwix/src/vars.c	2022/01/24 17:07:24	1.9.56.3
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@elwix.org>
 *
 * $Author: misho $
-* $Id: vars.c,v 1.9.56.2 2022/01/24 16:01:49 misho Exp $
+* $Id: vars.c,v 1.9.56.3 2022/01/24 17:07:24 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -252,7 +252,7 @@ buffer2vars(u_char * __restrict buf, int buflen, int v
 /*
  * ait_vars2tlv() - Marshaling data from array with variables to TLV buffer
  *
- * @buf = Buffer
+ * @buf = Buffer, If =NULL then we return only needed buffer size
  * @buflen = Size of buffer
  * @vars = Variable array
  * return: -1 error, 0 nothing done or >0 size of marshaled data
@@ -265,16 +265,19 @@ ait_vars2tlv(u_char * __restrict buf, int buflen, arra
 	ait_val_t *val;
 	u_char *dat;
 
-	assert(buf);
 	assert(vars);
-	if (!buf || !vars)
+	if (!vars)
 		return -1;
-	if (!buflen || !array_Size(vars))
+	if (!array_Size(vars))
 		return 0;
 
 	/* calculate amount of data into buffer */
-	for (i = 0, Limit = 0; i < array_Size(vars); i++, 
-			Limit += 5 + AIT_LEN(array(vars, i, ait_val_t*)));
+	for (i = 0, Limit = 0; i < array_Size(vars); 
+			Limit += 5 + AIT_LEN(array(vars, i, ait_val_t*)), i++);
+	/* check only needed buffer size */
+	if (!buf)
+		return Limit;
+
 	if (Limit > buflen) {
 		elwix_SetErr(EMSGSIZE, "Short buffer buflen=%d needed min %d", 
 				buflen, Limit);
@@ -369,7 +372,7 @@ ait_tlv2vars(u_char * __restrict buf, int buflen)
 		return NULL;
 
 	/* de-marshaling */
-	for (i = 0, dat = buf; i < buflen; i++) {
+	for (i = 0, dat = buf; *dat != empty && dat < (buf + buflen); i++) {
 		val = ait_getVars(&vars, i);
 		if (!val) {
 			ait_freeVars(&vars);