kern/89472: ipfw2 no longer supports filtering IPv6-over-IPv4 on 6.0-RELEASE

[Hajimu UMEMOTO]

Hi,

>>>>> On Wed, 23 Nov 2005 22:43:07 +0100 (CET)
>>>>> Gael Roualland <gael.roualland at dial.oleane.com> said:

gael>  Hum, I didn't notice the "ipv6" string was handled a bit differently
gael>  than the numeric proto number in ipfw.

gael>  It does work, at least IPv6-over-IPv4 packets are not blocked, but ipfw
gael>  list/show reports the rule as "allow ip from a.b.c.d to me" and it does
gael>  filter it that way, opening a lot more than just protocol 41...

Umm, 41 is treated as ipv6, internally.  With following patch,

	allow ip from a.b.c.d to me proto 41

should work for workaround.  However, it is still incomplete, and
`ipfw show' shows

	allow ip from any to any proto ipv6

Apart from this limitation, it seems working to me here.

Index: sbin/ipfw/ipfw2.c
diff -u -p sbin/ipfw/ipfw2.c.orig sbin/ipfw/ipfw2.c
--- sbin/ipfw/ipfw2.c.orig	Sat Aug 20 17:36:57 2005
+++ sbin/ipfw/ipfw2.c	Sun Nov 27 04:18:43 2005
@@ -3611,7 +3611,8 @@ add_proto(ipfw_insn *cmd, char *av, u_ch
 		*proto = pe->p_proto;
 	else
 		return NULL;
-	if (*proto != IPPROTO_IP && *proto != IPPROTO_IPV6)
+	if (strcmp(av, "ipv4") != 0 && strcmp(av, "ip4") != 0 &&
+	    strcmp(av, "ipv6") != 0 && strcmp(av, "ip6") != 0)
 		fill_cmd(cmd, O_PROTO, 0, *proto);
 
 	return cmd;


Sincerely,

--
Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan
ume at mahoroba.org  ume@{,jp.}FreeBSD.org
http://www.imasy.org/~ume/