This set allows the bpf-tcp-cc to call bpf_setsockopt. One use
case is to allow a bpf-tcp-cc switching to another cc during init().
For example, when the tcp flow is not ecn ready, the bpf_dctcp
can switch to another cc by calling setsockopt(TCP_CONGESTION).
bpf_getsockopt() is also added to have a symmetrical API, so
less usage surprise.
v2:
- Not allow switching to kernel's tcp_cdg because it is the only
kernel tcp-cc that stores a pointer to icsk_ca_priv.
Please see the commit log in patch 1 for details.
Test is added in patch 4 to check switching to tcp_cdg.
- Refactor the logic finding the offset of a func ptr
in the "struct tcp_congestion_ops" to prog_ops_moff()
in patch 1.
- bpf_setsockopt() has been disabled in release() since v1 (please
see commit log in patch 1 for reason). bpf_getsockopt() is
also disabled together in release() in v2 to avoid usage surprise
because both of them are usually expected to be available together.
bpf-tcp-cc can already use PTR_TO_BTF_ID to read from tcp_sock.
Martin KaFai Lau (4):
bpf: tcp: Allow bpf-tcp-cc to call bpf_(get|set)sockopt
bpf: selftests: Add sk_state to bpf_tcp_helpers.h
bpf: selftests: Add connect_to_fd_opts to network_helpers
bpf: selftests: Add dctcp fallback test
kernel/bpf/bpf_struct_ops.c | 22 +++-
net/core/filter.c | 6 +
net/ipv4/bpf_tcp_ca.c | 41 ++++++-
tools/testing/selftests/bpf/bpf_tcp_helpers.h | 1 +
tools/testing/selftests/bpf/network_helpers.c | 23 +++-
tools/testing/selftests/bpf/network_helpers.h | 6 +
.../selftests/bpf/prog_tests/bpf_tcp_ca.c | 106 ++++++++++++++----
.../selftests/bpf/prog_tests/kfunc_call.c | 2 +-
tools/testing/selftests/bpf/progs/bpf_dctcp.c | 25 +++++
.../selftests/bpf/progs/bpf_dctcp_release.c | 26 +++++
.../bpf/progs/kfunc_call_test_subprog.c | 4 +-
11 files changed, 230 insertions(+), 32 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/bpf_dctcp_release.c
--
2.30.2
