From: guy <guy>
Date: Fri, 14 Sep 2007 00:39:22 +0000 (+0000)
Subject: From pfhunt on SourceForge:
X-Git-Tag: tcpdump-3.9.8~3
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/aa1be4ccc7b6055a5f3037a0a4190053231cae5a

From pfhunt on SourceForge:

When a packet contains an IPv6 options header followed by an unknown IPv6
protocol payload, tcpdump displays the proto ID for the known option
header, not for the unknown payload.

For example, this is the output for an IPv6 packet containing a destination
options header, followed by a payload of (unknown) protocol 138:

# tcpdump -s 128 -i eth1
tcpdump: WARNING: addresses not searched
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 128 bytes
11:44:40.862572 I IP6 2007::10:5:2:163 > 2007::10:5:2:164: DSTOPT ip-proto-60 16

The ip-proto-60 refers to the destination option header (DSTOPT), rather
than displaying the unknown option 138, which I think would be more
informative.

The attached patch fixes this problem. With the patch applied, the output
for the packet is:

# tcpdump -s 128 -i eth1
tcpdump: WARNING: addresses not searched
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 128 bytes
11:48:26.160462 I IP6 2007::10:5:2:163 > 2007::10:5:2:164: DSTOPT ip-proto-138 16
---

diff --git a/CREDITS b/CREDITS
index 470c2ab4..da8534b0 100644
--- a/CREDITS
+++ b/CREDITS
@@ -116,6 +116,7 @@ Additional people who have contributed patches:
 	Pekka Savola 			<pekkas@netcore.fi>	
 	Peter Fales			<peter@fales-lorenz.net>
 	Peter Jeremy			<peter.jeremy@alcatel.com.au>
+					<pfhunt@users.sourceforge.net>
 	Phil Wood			<cpw@lanl.gov>
 	Rafal Maszkowski		<rzm@icm.edu.pl>
 	Raphael Raimbault		<raphael.raimbault@netasq.com>
diff --git a/print-ip6.c b/print-ip6.c
index 6294a132..b9e9983d 100644
--- a/print-ip6.c
+++ b/print-ip6.c
@@ -21,7 +21,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-ip6.c,v 1.47.2.3 2005-09-20 06:05:38 guy Exp $";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-ip6.c,v 1.47.2.4 2007-09-14 00:39:22 guy Exp $";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -225,7 +225,7 @@ ip6_print(register const u_char *bp, register u_int length)
 			return;
 
 		default:
-			(void)printf("ip-proto-%d %d", ip6->ip6_nxt, len);
+			(void)printf("ip-proto-%d %d", nh, len);
 			return;
 		}
 	}