netfilter: push reasm skb through instead of original frag skbs

Pushing original fragments through causes several problems. For example
for matching, frags may not be matched correctly. Take following
example:

<example>
On HOSTA do:
ip6tables -I INPUT -p icmpv6 -j DROP
ip6tables -I INPUT -p icmpv6 -m icmp6 --icmpv6-type 128 -j ACCEPT

and on HOSTB you do:
ping6 HOSTA -s2000    (MTU is 1500)

Incoming echo requests will be filtered out on HOSTA. This issue does
not occur with smaller packets than MTU (where fragmentation does not happen)
</example>

As was discussed previously, the only correct solution seems to be to use
reassembled skb instead of separete frags. Doing this has positive side
effects in reducing sk_buff by one pointer (nfct_reasm) and also the reams
dances in ipvs and conntrack can be removed.

Future plan is to remove net/ipv6/netfilter/nf_conntrack_reasm.c
entirely and use code in net/ipv6/reassembly.c instead.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jiri Pirko
2013-11-06 17:52:20 +01:00
committed by David S. Miller
parent 9037c3579a
commit 6aafeef03b
9 changed files with 13 additions and 203 deletions

View File

@@ -6,9 +6,7 @@ void nf_defrag_ipv6_enable(void);
int nf_ct_frag6_init(void);
void nf_ct_frag6_cleanup(void);
struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb, u32 user);
void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
struct net_device *in, struct net_device *out,
int (*okfn)(struct sk_buff *));
void nf_ct_frag6_consume_orig(struct sk_buff *skb);
struct inet_frags_ctl;