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 <hengqi.chen@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211021134752.1223426-3-hengqi.chen@gmail.com

1 files changed, 54 insertions, 0 deletions

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 000000000000..3eefdfed1db9
--- /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 <test_progs.h>
+#include <sys/un.h>
+#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);
+}