[PATCH bpf-next v3 0/5] Align BPF TCP CCs implementing cong_control() with non-BPF CCs

["Jörn-Thorben Hinz" <jthinz@mailbox.tu-berlin.de>]

Addressed feedback by Martin KaFai Lau in this v3 of the series. See the
details below.

This series corrects some inconveniences for a BPF TCP CC that
implements and uses tcp_congestion_ops.cong_control(). Until now, such a
CC did not have all necessary write access to struct sock and
unnecessarily needed to implement cong_avoid().

v3:
 - Add a selftest writing sk_pacing_*
 - Add a selftest with incomplete tcp_congestion_ops
 - Add a selftest with unsupported get_info()
 - Remove an unused variable
 - Reword a comment about reg() in bpf_struct_ops_map_update_elem()
v2:
 - Drop redundant check for required functions and just rely on
   tcp_register_congestion_control() (Martin KaFai Lau)

Jörn-Thorben Hinz (5):
  bpf: Allow a TCP CC to write sk_pacing_rate and sk_pacing_status
  bpf: Require only one of cong_avoid() and cong_control() from a TCP CC
  selftests/bpf: Test a BPF CC writing sk_pacing_*
  selftests/bpf: Test an incomplete BPF CC
  selftests/bpf: Test a BPF CC implementing the unsupported get_info()

 kernel/bpf/bpf_struct_ops.c                   |  7 +-
 net/ipv4/bpf_tcp_ca.c                         | 39 ++---------
 .../selftests/bpf/prog_tests/bpf_tcp_ca.c     | 66 +++++++++++++++++++
 .../bpf/progs/tcp_ca_incompl_cong_ops.c       | 35 ++++++++++
 .../bpf/progs/tcp_ca_unsupp_cong_op.c         | 21 ++++++
 .../bpf/progs/tcp_ca_write_sk_pacing.c        | 60 +++++++++++++++++
 6 files changed, 191 insertions(+), 37 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/tcp_ca_incompl_cong_ops.c
 create mode 100644 tools/testing/selftests/bpf/progs/tcp_ca_unsupp_cong_op.c
 create mode 100644 tools/testing/selftests/bpf/progs/tcp_ca_write_sk_pacing.c

-- 
2.30.2