From 4d92376beb265d57d97fddd06a32688671a64c3f Mon Sep 17 00:00:00 2001
From: jkim <jkim@FreeBSD.org>
Date: Fri, 29 Aug 2008 01:47:45 +0000
Subject: Simplify jump instruction range checks.

MFC after:	1 month
---
 sys/net/bpf_filter.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

(limited to 'sys/net')

diff --git a/sys/net/bpf_filter.c b/sys/net/bpf_filter.c
index 4064317..813d2f4 100644
--- a/sys/net/bpf_filter.c
+++ b/sys/net/bpf_filter.c
@@ -552,14 +552,13 @@ bpf_validate(f, len)
 		 * the code block.
 		 */
 		if (BPF_CLASS(p->code) == BPF_JMP) {
-			register int from = i + 1;
+			register u_int offset;
 
-			if (BPF_OP(p->code) == BPF_JA) {
-				if (from >= len || p->k >= len - from)
-					return 0;
-			}
-			else if (from >= len || p->jt >= len - from ||
-				 p->jf >= len - from)
+			if (BPF_OP(p->code) == BPF_JA)
+				offset = p->k;
+			else
+				offset = p->jt > p->jf ? p->jt : p->jf;
+			if (offset >= (u_int)(len - i) - 1)
 				return 0;
 		}
 		/*
-- 
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