1 files changed, 47 insertions, 32 deletions

diff --git a/net/netfilter/utils.c b/net/netfilter/utils.c
index 2182d361e273..008419db815a 100644
--- a/net/netfilter/utils.c
+++ b/net/netfilter/utils.c
@@ -179,39 +179,54 @@ int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
 }
 EXPORT_SYMBOL_GPL(nf_route);
 
-static int nf_ip_reroute(struct sk_buff *skb, const struct nf_queue_entry *entry)
+/* Only get and check the lengths, not do any hop-by-hop stuff. */
+int nf_ip6_check_hbh_len(struct sk_buff *skb, u32 *plen)
 {
-#ifdef CONFIG_INET
-	const struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
-
-	if (entry->state.hook == NF_INET_LOCAL_OUT) {
-		const struct iphdr *iph = ip_hdr(skb);
-
-		if (!(iph->tos == rt_info->tos &&
-		      skb->mark == rt_info->mark &&
-		      iph->daddr == rt_info->daddr &&
-		      iph->saddr == rt_info->saddr))
-			return ip_route_me_harder(entry->state.net, entry->state.sk,
-						  skb, RTN_UNSPEC);
+	int len, off = sizeof(struct ipv6hdr);
+	unsigned char *nh;
+
+	if (!pskb_may_pull(skb, off + 8))
+		return -ENOMEM;
+	nh = (unsigned char *)(ipv6_hdr(skb) + 1);
+	len = (nh[1] + 1) << 3;
+
+	if (!pskb_may_pull(skb, off + len))
+		return -ENOMEM;
+	nh = skb_network_header(skb);
+
+	off += 2;
+	len -= 2;
+	while (len > 0) {
+		int optlen;
+
+		if (nh[off] == IPV6_TLV_PAD1) {
+			off++;
+			len--;
+			continue;
+		}
+		if (len < 2)
+			return -EBADMSG;
+		optlen = nh[off + 1] + 2;
+		if (optlen > len)
+			return -EBADMSG;
+
+		if (nh[off] == IPV6_TLV_JUMBO) {
+			u32 pkt_len;
+
+			if (nh[off + 1] != 4 || (off & 3) != 2)
+				return -EBADMSG;
+			pkt_len = ntohl(*(__be32 *)(nh + off + 2));
+			if (pkt_len <= IPV6_MAXPLEN ||
+			    ipv6_hdr(skb)->payload_len)
+				return -EBADMSG;
+			if (pkt_len > skb->len - sizeof(struct ipv6hdr))
+				return -EBADMSG;
+			*plen = pkt_len;
+		}
+		off += optlen;
+		len -= optlen;
 	}
-#endif
-	return 0;
-}
-
-int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry)
-{
-	const struct nf_ipv6_ops *v6ops;
-	int ret = 0;
 
-	switch (entry->state.pf) {
-	case AF_INET:
-		ret = nf_ip_reroute(skb, entry);
-		break;
-	case AF_INET6:
-		v6ops = rcu_dereference(nf_ipv6_ops);
-		if (v6ops)
-			ret = v6ops->reroute(skb, entry);
-		break;
-	}
-	return ret;
+	return len ? -EBADMSG : 0;
 }
+EXPORT_SYMBOL_GPL(nf_ip6_check_hbh_len);