After migrate_dance() moves established children to the target listener, add it to an epoll set and verify that epoll_wait(..., 0) reports it ready before accept().
This adds epoll coverage for the TCP_ESTABLISHED reuseport migration case in migrate_reuseport. Keep the check limited to TCP_ESTABLISHED cases. TCP_SYN_RECV and TCP_NEW_SYN_RECV still depend on asynchronous handshake completion, so a zero-timeout epoll_wait() would race there. Signed-off-by: Zhenzhong Wu <[email protected]> --- .../bpf/prog_tests/migrate_reuseport.c | 32 ++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c index 653b0a20f..580a53424 100644 --- a/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c +++ b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c @@ -18,13 +18,16 @@ * 9. call shutdown() for the second server * and migrate the requests in the accept queue * to the last server socket. - * 10. call accept() for the last server socket. + * 10. for TCP_ESTABLISHED cases, call epoll_wait(..., 0) + * for the last server socket. + * 11. call accept() for the last server socket. * * Author: Kuniyuki Iwashima <[email protected]> */ #include <bpf/bpf.h> #include <bpf/libbpf.h> +#include <sys/epoll.h> #include "test_progs.h" #include "test_migrate_reuseport.skel.h" @@ -522,6 +525,33 @@ static void run_test(struct migrate_reuseport_test_case *test_case, goto close_clients; } + /* Only TCP_ESTABLISHED has already-migrated accept-queue entries + * here. Later states still depend on follow-up handshake work. + */ + if (test_case->state == BPF_TCP_ESTABLISHED) { + struct epoll_event ev = { + .events = EPOLLIN, + }; + int epfd; + int nfds; + + epfd = epoll_create1(EPOLL_CLOEXEC); + if (!ASSERT_NEQ(epfd, -1, "epoll_create1")) + goto close_clients; + + ev.data.fd = test_case->servers[MIGRATED_TO]; + if (!ASSERT_OK(epoll_ctl(epfd, EPOLL_CTL_ADD, + test_case->servers[MIGRATED_TO], &ev), + "epoll_ctl")) + goto close_epfd; + + nfds = epoll_wait(epfd, &ev, 1, 0); + ASSERT_EQ(nfds, 1, "epoll_wait"); + +close_epfd: + close(epfd); + } + count_requests(test_case, skel); close_clients: -- 2.43.0
