ipv6: Fix MLD Query message check

Based on RFC3810 6.2, we also need to check the hop limit and router alert
option besides source address.

Signed-off-by: Hangbin Liu <[email protected]>
Acked-by: YOSHIFUJI Hideaki <[email protected]>
Acked-by: Hannes Frederic Sowa <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
This commit is contained in:
Hangbin Liu 2014-06-27 09:57:53 +08:00 • committed by David S. Miller
commit e940f5d6ba

View file

@ -1301,8 +1301,17 @@ int igmp6_event_query(struct sk_buff *skb)
len = ntohs(ipv6_hdr(skb)->payload_len) + sizeof(struct ipv6hdr);
len -= skb_network_header_len(skb);
/* Drop queries with not link local source */
if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL))
/* RFC3810 6.2
* Upon reception of an MLD message that contains a Query, the node
* checks if the source address of the message is a valid link-local
* address, if the Hop Limit is set to 1, and if the Router Alert
* option is present in the Hop-By-Hop Options header of the IPv6
* packet. If any of these checks fails, the packet is dropped.
*/
if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL) ||
ipv6_hdr(skb)->hop_limit != 1 ||
!(IP6CB(skb)->flags & IP6SKB_ROUTERALERT) ||
IP6CB(skb)->ra != htons(IPV6_OPT_ROUTERALERT_MLD))
return -EINVAL;
idev = __in6_dev_get(skb->dev);