From: Masahide NAKAMURA <nakam@linux-ipv6.org>
Date: Mon, 12 Feb 2007 19:16:17 +0000 (-0800)
Subject: [NETFILTER]: ip6t_mh: drop piggyback payload packet on MH packets
X-Git-Tag: v2.6.21-rc1~274^2~1^2~4
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=138939e0662ccb0e805aefe400bcf9cfcbece8e7;p=linux-2.6

[NETFILTER]: ip6t_mh: drop piggyback payload packet on MH packets

Regarding RFC3775, MH payload proto field should be IPPROTO_NONE. Otherwise
it must be discarded (and the receiver should send ICMP error).

We assume filter should drop such piggyback everytime to disallow slipping
through firewall rules, even the final receiver will discard it.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/netfilter/ip6t_mh.c b/net/ipv6/netfilter/ip6t_mh.c
index 2c7efc6a50..c2a909893a 100644
--- a/net/ipv6/netfilter/ip6t_mh.c
+++ b/net/ipv6/netfilter/ip6t_mh.c
@@ -66,6 +66,13 @@ match(const struct sk_buff *skb,
 		return 0;
 	}
 
+	if (mh->ip6mh_proto != IPPROTO_NONE) {
+		duprintf("Dropping invalid MH Payload Proto: %u\n",
+			 mh->ip6mh_proto);
+		*hotdrop = 1;
+		return 0;
+	}
+
 	return type_match(mhinfo->types[0], mhinfo->types[1], mh->ip6mh_type,
 			  !!(mhinfo->invflags & IP6T_MH_INV_TYPE));
 }