[netfilter-cvslog] r6573 - trunk/iptables

[kaber at netfilter.org]

Author: kaber at netfilter.org
Date: 2006-03-29 11:24:43 +0200 (Wed, 29 Mar 2006)
New Revision: 6573

Modified:
   trunk/iptables/ip6tables.c
Log:
[PATCH] don't allow to specify protocol of IPv6 extension header (Yasuyuki Kozakai)

Sometimes I hear that people do 'ip6tables -p ah ...' which never matches
any packet. IPv6 extension headers except of ESP are skipped and invalid
as argument of '-p'. Then I propose that ip6tables exits with error in such
case.


Modified: trunk/iptables/ip6tables.c
===================================================================
--- trunk/iptables/ip6tables.c	2006-03-29 09:07:36 UTC (rev 6572)
+++ trunk/iptables/ip6tables.c	2006-03-29 09:24:43 UTC (rev 6573)
@@ -849,6 +849,17 @@
 	return (u_int16_t)proto;
 }
 
+/* proto means IPv6 extension header ? */
+static int is_exthdr(u_int16_t proto)
+{
+	return (proto == IPPROTO_HOPOPTS ||
+		proto == IPPROTO_ROUTING ||
+		proto == IPPROTO_FRAGMENT ||
+		proto == IPPROTO_ESP ||
+		proto == IPPROTO_AH ||
+		proto == IPPROTO_DSTOPTS);
+}
+
 void parse_interface(const char *arg, char *vianame, unsigned char *mask)
 {
 	int vialen = strlen(arg);
@@ -1926,6 +1937,11 @@
 			    && (fw.ipv6.invflags & IP6T_INV_PROTO))
 				exit_error(PARAMETER_PROBLEM,
 					   "rule would never match protocol");
+			
+			if (fw.ipv6.proto != IPPROTO_ESP &&
+			    is_exthdr(fw.ipv6.proto))
+				printf("Warning: never matched protocol: %s. "
+				       "use exension match instead.", protocol);
 			break;
 
 		case 's':