[PATCH bpf-next v2 0/6] Add SO_REUSEPORT support for TC bpf_sk_assign

[Lorenz Bauer]

We want to replace iptables TPROXY with a BPF program at TC ingress.
To make this work in all cases we need to assign a SO_REUSEPORT socket
to an skb, which is currently prohibited. This series adds support for
such sockets to bpf_sk_assing. See patch 5 for details.

I did some refactoring to cut down on the amount of duplicate code. The
key to this is to use INDIRECT_CALL in the reuseport helpers. To show
that this approach is not just beneficial to TC sk_assign I removed
duplicate code for bpf_sk_lookup as well.

Changes from v1:
- Correct commit abbrev length (Kuniyuki)
- Reduce duplication (Kuniyuki)
- Add checks on sk_state (Martin)
- Split exporting inet[6]_lookup_reuseport into separate patch (Eric)

Joint work with Daniel Borkmann.

Signed-off-by: Lorenz Bauer <lmb@xxxxxxxxxxxxx>
---
Daniel Borkmann (1):
      selftests/bpf: Test that SO_REUSEPORT can be used with sk_assign helper

Lorenz Bauer (5):
      net: export inet_lookup_reuseport and inet6_lookup_reuseport
      net: document inet[6]_lookup_reuseport sk_state requirements
      net: remove duplicate reuseport_lookup functions
      net: remove duplicate sk_lookup helpers
      bpf, net: Support SO_REUSEPORT sockets with bpf_sk_assign

 include/net/inet6_hashtables.h                     |  84 ++++++++-
 include/net/inet_hashtables.h                      |  77 +++++++-
 include/net/sock.h                                 |   7 +-
 include/uapi/linux/bpf.h                           |   3 -
 net/core/filter.c                                  |   2 -
 net/ipv4/inet_hashtables.c                         |  69 +++++---
 net/ipv4/udp.c                                     |  73 +++-----
 net/ipv6/inet6_hashtables.c                        |  71 +++++---
 net/ipv6/udp.c                                     |  85 +++------
 tools/include/uapi/linux/bpf.h                     |   3 -
 tools/testing/selftests/bpf/network_helpers.c      |   3 +
 .../selftests/bpf/prog_tests/assign_reuse.c        | 197 +++++++++++++++++++++
 .../selftests/bpf/progs/test_assign_reuse.c        | 142 +++++++++++++++
 13 files changed, 637 insertions(+), 179 deletions(-)
---
base-commit: 25085b4e9251c77758964a8e8651338972353642
change-id: 20230613-so-reuseport-e92c526173ee

Best regards,
-- 
Lorenz Bauer <lmb@xxxxxxxxxxxxx>