Re: [PATCH] netfilter: x_tables: allow to use cgroup match for LOCAL_IN nf hooks

[Daniel Borkmann <dborkman@redhat.com>]

On 03/19/2014 07:58 AM, Alexey Perevalov wrote:
> This simple modification allows iptables to work with INPUT chain
> in combination with cgroup module. It could be useful for counting
> ingress traffic per cgroup with nfacct netfilter module. There
> were no problems to count the egress traffic that way formerly.
>
> It's possible to get classified sk_buff after PREROUTING, due to
> socket lookup being done in early_demux (tcp_v4_early_demux). Also
> it works for udp as well.
>
> Trivial usage example, assuming we're in the same shell every step
> and we have enough permissions:
>
> 1) Classic net_cls cgroup initialization:
>
>    mkdir /sys/fs/cgroup/net_cls
>    mount -t cgroup -o net_cls net_cls /sys/fs/cgroup/net_cls
>
> 2) Set up cgroup for interesting application:
>
>    mkdir /sys/fs/cgroup/net_cls/wget
>    echo 1 > /sys/fs/cgroup/net_cls/wget/net_cls.classid
>    echo $BASHPID > /sys/fs/cgroup/net_cls/wget/cgroup.procs
>
> 3) Create kernel counters:
>
>    nfacct add wget-cgroup-in
>    iptables -A INPUT -m cgroup ! --cgroup 1 -m nfacct --nfacct-name wget-cgroup-in
>
>    nfacct add wget-cgroup-out
>    iptables -A OUTPUT -m cgroup ! --cgroup 1 -m nfacct --nfacct-name wget-cgroup-out
>
> 4) Network usage:
>
>    wget https://www.kernel.org/pub/linux/kernel/v3.x/testing/linux-3.14-rc6.tar.xz
>
> 5) Check results:
>
>    nfacct list
>
> Cgroup approach is being used for the DataUsage (counting & blocking
> traffic) feature for Samsung's modification of the Tizen OS.
>
> Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>

Acked-by: Daniel Borkmann <dborkman@redhat.com>