netdev - Re: [PATCH bpf-next v9 0/9] bpf: getsockopt and setsockopt hooks

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Date:   Thu, 27 Jun 2019 15:31:49 -0700
From:   Alexei Starovoitov <alexei.starovoitov@...il.com>
To:     Stanislav Fomichev <sdf@...gle.com>
Cc:     netdev@...r.kernel.org, bpf@...r.kernel.org, davem@...emloft.net,
        ast@...nel.org, daniel@...earbox.net
Subject: Re: [PATCH bpf-next v9 0/9] bpf: getsockopt and setsockopt hooks

On Thu, Jun 27, 2019 at 01:38:46PM -0700, Stanislav Fomichev wrote:
> This series implements two new per-cgroup hooks: getsockopt and
> setsockopt along with a new sockopt program type. The idea is pretty
> similar to recently introduced cgroup sysctl hooks, but
> implementation is simpler (no need to convert to/from strings).
> 
> What this can be applied to:
> * move business logic of what tos/priority/etc can be set by
>   containers (either pass or reject)
> * handle existing options (or introduce new ones) differently by
>   propagating some information in cgroup/socket local storage
> 
> Compared to a simple syscall/{g,s}etsockopt tracepoint, those
> hooks are context aware. Meaning, they can access underlying socket
> and use cgroup and socket local storage.
> 
> v9:
> * allow overwriting setsocktop arguments (Alexei Starovoitov)
>   (see individual changes for more changelog details)

Applied. Thanks.

There is a build warning though:
test_sockopt_sk.c: In function ‘getsetsockopt’:
test_sockopt_sk.c:115:2: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
  if (*(__u32 *)buf != 0x55AA*2) {
  ^~
test_sockopt_sk.c:116:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   log_err("Unexpected getsockopt(SO_SNDBUF) 0x%x != 0x55AA*2",
   ^~~~~~~

Pls fix it in the follow up.