[NETFILTER]: convert nfmark and conntrack mark to 32bit

As discussed at netconf'05, we convert nfmark and conntrack-mark to be
32bits even on 64bit architectures.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/netfilter/ipt_mark.c b/net/ipv4/netfilter/ipt_mark.c
index 8955728..00bef6c 100644
--- a/net/ipv4/netfilter/ipt_mark.c
+++ b/net/ipv4/netfilter/ipt_mark.c
@@ -37,9 +37,16 @@
            unsigned int matchsize,
            unsigned int hook_mask)
 {
+	struct ipt_mark_info *minfo = (struct ipt_mark_info *) matchinfo;
+
 	if (matchsize != IPT_ALIGN(sizeof(struct ipt_mark_info)))
 		return 0;
 
+	if (minfo->mark > 0xffffffff || minfo->mask > 0xffffffff) {
+		printk(KERN_WARNING "mark: only supports 32bit mark\n");
+		return 0;
+	}
+
 	return 1;
 }