On Mon, Jul 6, 2020 at 4:02 PM Stanislav Fomichev <[email protected]> wrote:
>
> Implement BPF_CGROUP_INET_SOCK_RELEASE hook that triggers
> on inet socket release. It triggers only for userspace
> sockets, the same semantics as existing BPF_CGROUP_INET_SOCK_CREATE.
>
> The only questionable part here is the sock->sk check
> in the inet_release. Looking at the places where we
> do 'sock->sk = NULL', I don't understand how it can race
> with inet_release and why the check is there (it's been
> there since the initial git import). Otherwise, the
> change itself is pretty simple, we add a BPF hook
> to the inet_release and avoid calling it for kernel
> sockets.
>
> Signed-off-by: Stanislav Fomichev <[email protected]>
> ---
>  include/linux/bpf-cgroup.h | 4 ++++
>  include/uapi/linux/bpf.h   | 1 +
>  kernel/bpf/syscall.c       | 3 +++
>  net/core/filter.c          | 1 +
>  net/ipv4/af_inet.c         | 3 +++
>  5 files changed, 12 insertions(+)
>

Looks good overall, but I have no idea about sock->sk NULL case.

Acked-by: Andrii Nakryiko <[email protected]>

> diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
> index c66c545e161a..2c6f26670acc 100644
> --- a/include/linux/bpf-cgroup.h
> +++ b/include/linux/bpf-cgroup.h

[...]

Reply via email to