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_SK_STORAGE_GET_F_CLONE flag that can be passed to
bpf_sk_storage_get. This new flag indicates that that particular
bpf_sk_storage_elem should be cloned when the socket is cloned.
Cc: Martin KaFai Lau <kafai@xxxxxx>
Stanislav Fomichev (3):
bpf: support cloning sk storage on accept()
bpf: sync bpf.h to tools/
selftests/bpf: add sockopt clone/inheritance test
include/net/bpf_sk_storage.h | 10 +
include/uapi/linux/bpf.h | 1 +
net/core/bpf_sk_storage.c | 102 ++++++-
net/core/sock.c | 9 +-
tools/include/uapi/linux/bpf.h | 1 +
tools/testing/selftests/bpf/.gitignore | 1 +
tools/testing/selftests/bpf/Makefile | 3 +-
.../selftests/bpf/progs/sockopt_inherit.c | 102 +++++++
.../selftests/bpf/test_sockopt_inherit.c | 252 ++++++++++++++++++
9 files changed, 473 insertions(+), 8 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/sockopt_inherit.c
create mode 100644 tools/testing/selftests/bpf/test_sockopt_inherit.c
--
2.22.0.770.g0f2c4a37fd-goog
