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| author | Florian Westphal <fw@strlen.de> | 2017-03-09 23:22:30 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-20 10:04:54 +0100 |
| commit | fbdf477fcff6b16869665cbf7a38c1b6dbfe0d8a (patch) | |
| tree | 336ac8245bd1685027437878984a1af077cb2542 | |
| parent | 7edb2d2d86808c05ea75f4269c41bcc775988b08 (diff) | |
| download | linux-stable-fbdf477fcff6b16869665cbf7a38c1b6dbfe0d8a.tar.gz linux-stable-fbdf477fcff6b16869665cbf7a38c1b6dbfe0d8a.tar.bz2 linux-stable-fbdf477fcff6b16869665cbf7a38c1b6dbfe0d8a.zip | |
netfilter: bridge: honor frag_max_size when refragmenting
[ Upstream commit 4ca60d08cbe65f501baad64af50fceba79c19fbb ]
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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 97fc19f001bf..55dcb2b20b59 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -701,18 +701,20 @@ 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. */ |