On 8/14/19 7:37 PM, Stanislav Fomichev wrote:
Currently there is no way to propagate sk storage from the listener socket to a newly accepted one. Consider the following use case:fd = socket(); setsockopt(fd, SOL_IP, IP_TOS,...); /* ^^^ setsockopt BPF program triggers here and saves something * into sk storage of the listener. */ listen(fd, ...); while (client = accept(fd)) { /* At this point all association between listener * socket and newly accepted one is gone. New * socket will not have any sk storage attached. */ } Let's add new BPF_F_CLONE flag that can be specified when creating a socket storage map. This new flag indicates that map contents should be cloned when the socket is cloned. v4: * drop 'goto err' in bpf_sk_storage_clone (Yonghong Song) * add comment about race with bpf_sk_storage_map_free to the bpf_sk_storage_clone side as well (Daniel Borkmann) v3: * make sure BPF_F_NO_PREALLOC is always present when creating a map (Martin KaFai Lau) * don't call bpf_sk_storage_free explicitly, rely on sk_free_unlock_clone to do the cleanup (Martin KaFai Lau) v2: * remove spinlocks around selem_link_map/sk (Martin KaFai Lau) * BPF_F_CLONE on a map, not selem (Martin KaFai Lau) * hold a map while cloning (Martin KaFai Lau) * use BTF maps in selftests (Yonghong Song) * do proper cleanup selftests; don't call close(-1) (Yonghong Song) * export bpf_map_inc_not_zero Cc: Martin KaFai Lau <ka...@fb.com> Cc: Yonghong Song <y...@fb.com> Stanislav Fomichev (4): bpf: export bpf_map_inc_not_zero bpf: support cloning sk storage on accept() bpf: sync bpf.h to tools/ selftests/bpf: add sockopt clone/inheritance test include/linux/bpf.h | 2 + include/net/bpf_sk_storage.h | 10 + include/uapi/linux/bpf.h | 3 + kernel/bpf/syscall.c | 16 +- net/core/bpf_sk_storage.c | 104 ++++++- net/core/sock.c | 9 +- tools/include/uapi/linux/bpf.h | 3 + tools/testing/selftests/bpf/.gitignore | 1 + tools/testing/selftests/bpf/Makefile | 3 +- .../selftests/bpf/progs/sockopt_inherit.c | 97 +++++++ .../selftests/bpf/test_sockopt_inherit.c | 253 ++++++++++++++++++ 11 files changed, 491 insertions(+), 10 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/sockopt_inherit.c create mode 100644 tools/testing/selftests/bpf/test_sockopt_inherit.c
Applied, thanks!
