Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2023-08-16

We've added 17 non-merge commits during the last 6 day(s) which contain
a total of 20 files changed, 1179 insertions(+), 37 deletions(-).

The main changes are:

1) Add a BPF hook in sys_socket() to change the protocol ID
   from IPPROTO_TCP to IPPROTO_MPTCP to cover migration for legacy
   applications, from Geliang Tang.

2) Follow-up/fallout fix from the SO_REUSEPORT + bpf_sk_assign work
   to fix a splat on non-fullsock sks in inet[6]_steal_sock,
   from Lorenz Bauer.

3) Improvements to struct_ops links to avoid forcing presence of
   update/validate callbacks. Also add bpf_struct_ops fields documentation,
   from David Vernet.

4) Ensure libbpf sets close-on-exec flag on gzopen, from Marco Vedovati.

5) Several new tcx selftest additions and bpftool link show support for
   tcx and xdp links, from Daniel Borkmann.

6) Fix a smatch warni...