From: dlg <dlg@openbsd.org>
Date: Mon, 28 Mar 2022 02:58:06 +0000 (+0000)
Subject: tweak the pflog ifname filter to include the terminating nul.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=daa036ab29b3b631024303b79474dba44bcc1380;p=openbsd

tweak the pflog ifname filter to include the terminating nul.

without this the code effectively just compares the start of the
string, which means you can get a prefix match unexpectedly. including
the nul in the comparison means it only works for whole interface
names, as it was originally intended.

reported by Aner Perez on misc@
ok deraadt@ (who also dug through the history behind this)
---

diff --git a/lib/libpcap/gencode.c b/lib/libpcap/gencode.c
index d15f17403d5..572e48d1f7a 100644
--- a/lib/libpcap/gencode.c
+++ b/lib/libpcap/gencode.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gencode.c,v 1.60 2022/02/13 20:02:30 otto Exp $	*/
+/*	$OpenBSD: gencode.c,v 1.61 2022/03/28 02:58:06 dlg Exp $	*/
 
 /*
  * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998
@@ -3230,7 +3230,7 @@ gen_pf_ifname(char *ifname)
 		    len - 1);
 		/* NOTREACHED */
 	}
-	b0 = gen_bcmp(off, strlen(ifname), ifname);
+	b0 = gen_bcmp(off, strlen(ifname) + 1, ifname);
 	return (b0);
 }