Re: DDoS attack causing bad effect on conntrack searches
From: Eric Dumazet <hidden>
Date: 2010-06-01 10:31:56
Also in:
netfilter-devel
From: Eric Dumazet <hidden>
Date: 2010-06-01 10:31:56
Also in:
netfilter-devel
Le mardi 01 juin 2010 à 12:18 +0200, Patrick McHardy a écrit :
If a new conntrack is created in PRE_ROUTING or LOCAL_OUT, it will be added to the unconfirmed list and moved to the hash as soon as the packet passes POST_ROUTING. This means the number of unconfirmed entries created by the network is bound by the number of CPUs due to BH processing. The number created by locally generated packets is unbound in case of preemptible kernels however.
OK, we should have a percpu list then. BTW, I notice nf_conntrack_untracked is incorrectly annotated '__read_mostly'. It can be written very often :( Should'nt we special case it and let be really const ?