[PATCH v2 bpf-next 0/4] flow_dissector: Allow bpf flow-dissector progs to request fallback to normal dissection

[Shmulik Ladkani <shmulik@xxxxxxxxxxxxxxxx>]

Currently, attaching BPF_PROG_TYPE_FLOW_DISSECTOR programs completely
replaces the flow-dissector logic with custom dissection logic.
This forces implementors to write programs that handle dissection for
any flows expected in the namespace.

It makes sense for flow-dissector bpf programs to just augment the
dissector with custom logic (e.g. dissecting certain flows or custom
protocols), while enjoying the broad capabilities of the standard
dissector for any other traffic.

v2:
- Extend selftests/bpf/progs/bpf_flow.c to exercise new ret code

Shmulik Ladkani (4):
  flow_dissector: Make 'bpf_flow_dissect' return the bpf program retcode
  bpf/flow_dissector: Introduce BPF_FLOW_DISSECTOR_CONTINUE retcode for
    flow-dissector bpf progs
  bpf: test_run: Propagate bpf_flow_dissect's retval to user's
    bpf_attr.test.retval
  selftests/bpf: test BPF_FLOW_DISSECTOR_CONTINUE

 include/linux/skbuff.h                        |  4 +-
 include/uapi/linux/bpf.h                      |  5 +++
 net/core/flow_dissector.c                     | 16 ++++---
 tools/include/uapi/linux/bpf.h                |  5 +++
 .../selftests/bpf/prog_tests/flow_dissector.c | 44 ++++++++++++++++++-
 .../prog_tests/flow_dissector_load_bytes.c    |  2 +-
 tools/testing/selftests/bpf/progs/bpf_flow.c  | 15 +++++++
 .../selftests/bpf/test_flow_dissector.sh      |  8 ++++
 8 files changed, 89 insertions(+), 10 deletions(-)

-- 
2.37.2