On 06/27, Alexei Starovoitov wrote:
> 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.
Great, thanks for all the reviews!
> 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.
Sure, but I can't reproduce it with gcc7 nor with clang9 :-/
Presumably, a switch to __get_unaligned_cpu32 should help,
I'll try to play with compilers a bit before sending a fix.
