From b6c4e71516099be676ebd897ea440ce2dddca6d1 Mon Sep 17 00:00:00 2001 From: Hengqi Chen Date: Thu, 21 Oct 2021 21:47:52 +0800 Subject: [PATCH] selftests/bpf: Test bpf_skc_to_unix_sock() helper Add a new test which triggers unix_listen kernel function to test bpf_skc_to_unix_sock helper. Signed-off-by: Hengqi Chen Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20211021134752.1223426-3-hengqi.chen@gmail.com --- .../selftests/bpf/prog_tests/skc_to_unix_sock.c | 54 ++++++++++++++++++++++ .../selftests/bpf/progs/test_skc_to_unix_sock.c | 40 ++++++++++++++++ 2 files changed, 94 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/skc_to_unix_sock.c create mode 100644 tools/testing/selftests/bpf/progs/test_skc_to_unix_sock.c diff --git a/tools/testing/selftests/bpf/prog_tests/skc_to_unix_sock.c b/tools/testing/selftests/bpf/prog_tests/skc_to_unix_sock.c new file mode 100644 index 0000000..3eefdfe --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/skc_to_unix_sock.c @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2021 Hengqi Chen */ + +#include +#include +#include "test_skc_to_unix_sock.skel.h" + +static const char *sock_path = "@skc_to_unix_sock"; + +void test_skc_to_unix_sock(void) +{ + struct test_skc_to_unix_sock *skel; + struct sockaddr_un sockaddr; + int err, sockfd = 0; + + skel = test_skc_to_unix_sock__open(); + if (!ASSERT_OK_PTR(skel, "could not open BPF object")) + return; + + skel->rodata->my_pid = getpid(); + + err = test_skc_to_unix_sock__load(skel); + if (!ASSERT_OK(err, "could not load BPF object")) + goto cleanup; + + err = test_skc_to_unix_sock__attach(skel); + if (!ASSERT_OK(err, "could not attach BPF object")) + goto cleanup; + + /* trigger unix_listen */ + sockfd = socket(AF_UNIX, SOCK_STREAM, 0); + if (!ASSERT_GT(sockfd, 0, "socket failed")) + goto cleanup; + + memset(&sockaddr, 0, sizeof(sockaddr)); + sockaddr.sun_family = AF_UNIX; + strncpy(sockaddr.sun_path, sock_path, strlen(sock_path)); + sockaddr.sun_path[0] = '\0'; + + err = bind(sockfd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)); + if (!ASSERT_OK(err, "bind failed")) + goto cleanup; + + err = listen(sockfd, 1); + if (!ASSERT_OK(err, "listen failed")) + goto cleanup; + + ASSERT_EQ(strcmp(skel->bss->path, sock_path), 0, "bpf_skc_to_unix_sock failed"); + +cleanup: + if (sockfd) + close(sockfd); + test_skc_to_unix_sock__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_skc_to_unix_sock.c b/tools/testing/selftests/bpf/progs/test_skc_to_unix_sock.c new file mode 100644 index 0000000..a408ec9 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_skc_to_unix_sock.c @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2021 Hengqi Chen */ + +#include "vmlinux.h" +#include +#include +#include "bpf_tracing_net.h" + +const volatile pid_t my_pid = 0; +char path[256] = {}; + +SEC("fentry/unix_listen") +int BPF_PROG(unix_listen, struct socket *sock, int backlog) +{ + pid_t pid = bpf_get_current_pid_tgid() >> 32; + struct unix_sock *unix_sk; + int i, len; + + if (pid != my_pid) + return 0; + + unix_sk = (struct unix_sock *)bpf_skc_to_unix_sock(sock->sk); + if (!unix_sk) + return 0; + + if (!UNIX_ABSTRACT(unix_sk)) + return 0; + + len = unix_sk->addr->len - sizeof(short); + path[0] = '@'; + for (i = 1; i < len; i++) { + if (i >= sizeof(struct sockaddr_un)) + break; + + path[i] = unix_sk->addr->name->sun_path[i]; + } + return 0; +} + +char _license[] SEC("license") = "GPL"; -- 2.7.4