svn commit: r223941 - stable/8/contrib/libpcap/bpf/net

[Xin LI]

Author: delphij
Date: Tue Jul 12 01:16:43 2011
New Revision: 223941
URL: http://svn.freebsd.org/changeset/base/223941

Log:
  MFC r223616:
  
  Incorporate vendor commit ecdc5c0a7f7591a7cd4a:
  
  In userland, sign extend the offset for JA instructions.
  
  We currently use that to implement "ip6 protochain", and "pc" might be
  wider than "pc->k", in which case we need to arrange that "pc->k" be
  sign-extended, by casting it to bpf_int32.
  
  PR:		kern/157188
  Submitted by:	plosher

Modified:
  stable/8/contrib/libpcap/bpf/net/bpf_filter.c
Directory Properties:
  stable/8/contrib/libpcap/   (props changed)

Modified: stable/8/contrib/libpcap/bpf/net/bpf_filter.c
==============================================================================
--- stable/8/contrib/libpcap/bpf/net/bpf_filter.c	Tue Jul 12 00:31:11 2011	(r223940)
+++ stable/8/contrib/libpcap/bpf/net/bpf_filter.c	Tue Jul 12 01:16:43 2011	(r223941)
@@ -396,7 +396,18 @@ bpf_filter(pc, p, wirelen, buflen)
 			continue;
 
 		case BPF_JMP|BPF_JA:
+#if defined(KERNEL) || defined(_KERNEL)
+			/*
+			 * No backward jumps allowed.
+			 */
 			pc += pc->k;
+#else
+			/*
+			 * XXX - we currently implement "ip6 protochain"
+			 * with backward jumps, so sign-extend pc->k.
+			 */
+			pc += (bpf_int32)pc->k;
+#endif
 			continue;
 
 		case BPF_JMP|BPF_JGT|BPF_K: