diff options
| author | Florian Westphal <fw@strlen.de> | 2017-03-09 23:22:30 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-03-13 13:31:53 +0100 |
| commit | 4ca60d08cbe65f501baad64af50fceba79c19fbb (patch) | |
| tree | be372957b85ba2ec2bb420fc96cf2ab3b7e02fe9 /net | |
| parent | 10596608c4d62cb8c1c2b806debcbd32fe657e71 (diff) | |
| download | linux-0-day-4ca60d08cbe65f501baad64af50fceba79c19fbb.tar.gz linux-0-day-4ca60d08cbe65f501baad64af50fceba79c19fbb.tar.xz | |
netfilter: bridge: honor frag_max_size when refragmenting
consider a bridge with mtu 9000, but end host sending smaller
packets to another host with mtu < 9000.
In this case, after reassembly, bridge+defrag would refragment,
and then attempt to send the reassembled packet as long as it
was below 9k.
Instead we have to cap by the largest fragment size seen.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bridge/br_netfilter_hooks.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index 95087e6e82583..3c5185021c1c0 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -721,18 +721,20 @@ static unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb) static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff *skb) { - struct nf_bridge_info *nf_bridge; - unsigned int mtu_reserved; + struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); + unsigned int mtu, mtu_reserved; mtu_reserved = nf_bridge_mtu_reduction(skb); + mtu = skb->dev->mtu; + + if (nf_bridge->frag_max_size && nf_bridge->frag_max_size < mtu) + mtu = nf_bridge->frag_max_size; - if (skb_is_gso(skb) || skb->len + mtu_reserved <= skb->dev->mtu) { + if (skb_is_gso(skb) || skb->len + mtu_reserved <= mtu) { nf_bridge_info_free(skb); return br_dev_queue_push_xmit(net, sk, skb); } - nf_bridge = nf_bridge_info_get(skb); - /* This is wrong! We should preserve the original fragment * boundaries by preserving frag_list rather than refragmenting. */ |