--- libaitio/src/bpf.c	2013/10/21 16:12:57	1.3.8.3
+++ libaitio/src/bpf.c	2013/10/21 21:12:42	1.4
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@elwix.org>
 *
 * $Author: misho $
-* $Id: bpf.c,v 1.3.8.3 2013/10/21 16:12:57 misho Exp $
+* $Id: bpf.c,v 1.4 2013/10/21 21:12:42 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -194,12 +194,20 @@ io_etherOpen(const char *csIface, int flags, int whdr,
 	}
 
 	if (!zcbuf) {
-		n = (buflen && *buflen) ? *buflen : getpagesize();
+		if (ioctl(eth, BIOCGBLEN, &n) == -1) {
+			LOGERR;
+			close(eth);
+			return -1;
+		} else
+			n = (buflen && *buflen) ? *buflen : getpagesize();
+
 		if (ioctl(eth, BIOCSBLEN, &n) == -1) {
 			LOGERR;
 			close(eth);
 			return -1;
 		}
+		if (buflen)
+			*buflen = n;
 	} else {
 #ifdef __FreeBSD__
 		n = BPF_BUFMODE_ZBUF;
@@ -234,15 +242,6 @@ io_etherOpen(const char *csIface, int flags, int whdr,
 		LOGERR;
 		io_etherClose(eth, zcbuf);
 		return -1;
-	}
-
-	if (buflen && *buflen) {
-		if (ioctl(eth, BIOCGBLEN, &n) == -1) {
-			LOGERR;
-			io_etherClose(eth, zcbuf);
-			return -1;
-		} else
-			*buflen = n;
 	}
 
 	return eth;