From 6fdd671baaf587cca17603485f9ef4bf7a1f9be1 Mon Sep 17 00:00:00 2001 From: Florent Revest Date: Wed, 10 Feb 2021 12:14:06 +0100 Subject: [PATCH] selftests/bpf: Add a selftest for the tracing bpf_get_socket_cookie This builds up on the existing socket cookie test which checks whether the bpf_get_socket_cookie helpers provide the same value in cgroup/connect6 and sockops programs for a socket created by the userspace part of the test. Instead of having an update_cookie sockops program tag a socket local storage with 0xFF, this uses both an update_cookie_sockops program and an update_cookie_tracing program which succesively tag the socket with 0x0F and then 0xF0. Signed-off-by: Florent Revest Signed-off-by: Alexei Starovoitov Acked-by: KP Singh Link: https://lore.kernel.org/bpf/20210210111406.785541-5-revest@chromium.org --- .../selftests/bpf/prog_tests/socket_cookie.c | 11 +++++-- .../selftests/bpf/progs/socket_cookie_prog.c | 36 ++++++++++++++++++++-- 2 files changed, 41 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/socket_cookie.c b/tools/testing/selftests/bpf/prog_tests/socket_cookie.c index e12a31d3..232db28 100644 --- a/tools/testing/selftests/bpf/prog_tests/socket_cookie.c +++ b/tools/testing/selftests/bpf/prog_tests/socket_cookie.c @@ -35,9 +35,14 @@ void test_socket_cookie(void) if (!ASSERT_OK_PTR(skel->links.set_cookie, "prog_attach")) goto close_cgroup_fd; - skel->links.update_cookie = bpf_program__attach_cgroup( - skel->progs.update_cookie, cgroup_fd); - if (!ASSERT_OK_PTR(skel->links.update_cookie, "prog_attach")) + skel->links.update_cookie_sockops = bpf_program__attach_cgroup( + skel->progs.update_cookie_sockops, cgroup_fd); + if (!ASSERT_OK_PTR(skel->links.update_cookie_sockops, "prog_attach")) + goto close_cgroup_fd; + + skel->links.update_cookie_tracing = bpf_program__attach( + skel->progs.update_cookie_tracing); + if (!ASSERT_OK_PTR(skel->links.update_cookie_tracing, "prog_attach")) goto close_cgroup_fd; server_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0); diff --git a/tools/testing/selftests/bpf/progs/socket_cookie_prog.c b/tools/testing/selftests/bpf/progs/socket_cookie_prog.c index fbd5eaf..35630a5 100644 --- a/tools/testing/selftests/bpf/progs/socket_cookie_prog.c +++ b/tools/testing/selftests/bpf/progs/socket_cookie_prog.c @@ -5,6 +5,7 @@ #include #include +#include #define AF_INET6 10 @@ -20,6 +21,14 @@ struct { __type(value, struct socket_cookie); } socket_cookies SEC(".maps"); +/* + * These three programs get executed in a row on connect() syscalls. The + * userspace side of the test creates a client socket, issues a connect() on it + * and then checks that the local storage associated with this socket has: + * cookie_value == local_port << 8 | 0xFF + * The different parts of this cookie_value are appended by those hooks if they + * all agree on the output of bpf_get_socket_cookie(). + */ SEC("cgroup/connect6") int set_cookie(struct bpf_sock_addr *ctx) { @@ -33,14 +42,14 @@ int set_cookie(struct bpf_sock_addr *ctx) if (!p) return 1; - p->cookie_value = 0xFF; + p->cookie_value = 0xF; p->cookie_key = bpf_get_socket_cookie(ctx); return 1; } SEC("sockops") -int update_cookie(struct bpf_sock_ops *ctx) +int update_cookie_sockops(struct bpf_sock_ops *ctx) { struct bpf_sock *sk = ctx->sk; struct socket_cookie *p; @@ -61,9 +70,30 @@ int update_cookie(struct bpf_sock_ops *ctx) if (p->cookie_key != bpf_get_socket_cookie(ctx)) return 1; - p->cookie_value = (ctx->local_port << 8) | p->cookie_value; + p->cookie_value |= (ctx->local_port << 8); return 1; } +SEC("fexit/inet_stream_connect") +int BPF_PROG(update_cookie_tracing, struct socket *sock, + struct sockaddr *uaddr, int addr_len, int flags) +{ + struct socket_cookie *p; + + if (uaddr->sa_family != AF_INET6) + return 0; + + p = bpf_sk_storage_get(&socket_cookies, sock->sk, 0, 0); + if (!p) + return 0; + + if (p->cookie_key != bpf_get_socket_cookie(sock->sk)) + return 0; + + p->cookie_value |= 0xF0; + + return 0; +} + char _license[] SEC("license") = "GPL"; -- 2.7.4