This set is to allow bpf tcp iter to call bpf_(get|set)sockopt. With bpf-tcp-cc, new algo rollout happens more often. Instead of restarting the applications to pick up the new tcp-cc, this set allows the bpf tcp iter to call bpf_(get|set)sockopt(TCP_CONGESTION). It is not limited to TCP_CONGESTION, the bpf tcp iter can call bpf_(get|set)sockopt() with other options. The bpf tcp iter can read into all the fields of a tcp_sock, so there is a lot of flexibility to select the desired sk to do setsockopt(), e.g. it can test for TCP_LISTEN only and leave the established connections untouched, or check the addr/port, or check the current tcp-cc name, ...etc. Patch 1-4 are some cleanup and prep work in the tcp and bpf seq_file. Patch 5 is to have the tcp seq_file iterate on the port+addr lhash2 instead of the port only listening_hash. Patch 6 is to have the bpf tcp iter doing batching which then allows lock_sock. lock_sock is needed for setsockopt. Patch 7 allows the bpf tcp iter to call bpf_(get|set)sockopt. v2: - Use __GFP_NOWARN in patch 6 - Add bpf_getsockopt() in patch 7 to give a symmetrical user experience. selftest in patch 8 is changed to also cover bpf_getsockopt(). - Remove CAP_NET_ADMIN check in patch 7. Tracing bpf prog has already required CAP_SYS_ADMIN or CAP_PERFMON. - Move some def macros to bpf_tracing_net.h in patch 8 Martin KaFai Lau (8): tcp: seq_file: Avoid skipping sk during tcp_seek_last_pos tcp: seq_file: Refactor net and family matching bpf: tcp: seq_file: Remove bpf_seq_afinfo from tcp_iter_state tcp: seq_file: Add listening_get_first() tcp: seq_file: Replace listening_hash with lhash2 bpf: tcp: bpf iter batching and lock_sock bpf: tcp: Support bpf_(get|set)sockopt in bpf tcp iter bpf: selftest: Test batching and bpf_(get|set)sockopt in bpf tcp iter include/linux/bpf.h | 8 + include/net/inet_hashtables.h | 6 + include/net/tcp.h | 1 - kernel/bpf/bpf_iter.c | 22 + kernel/trace/bpf_trace.c | 7 +- net/core/filter.c | 34 ++ net/ipv4/tcp_ipv4.c | 410 ++++++++++++++---- tools/testing/selftests/bpf/network_helpers.c | 85 +++- tools/testing/selftests/bpf/network_helpers.h | 4 + .../bpf/prog_tests/bpf_iter_setsockopt.c | 226 ++++++++++ .../selftests/bpf/progs/bpf_iter_setsockopt.c | 72 +++ .../selftests/bpf/progs/bpf_tracing_net.h | 6 + 12 files changed, 784 insertions(+), 97 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/bpf_iter_setsockopt.c create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_setsockopt.c -- 2.30.2
