Commit b6c4e715 authored by Hengqi Chen's avatar Hengqi Chen Committed by Alexei Starovoitov
Browse files

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: default avatarHengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211021134752.1223426-3-hengqi.chen@gmail.com
parent 9eeb3aa3

tools/testing/selftests/bpf/prog_tests/skc_to_unix_sock.c

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/* 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);

}

tools/testing/selftests/bpf/progs/test_skc_to_unix_sock.c

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/* SPDX-License-Identifier: GPL-2.0 */

/* Copyright (c) 2021 Hengqi Chen */



#include "vmlinux.h"

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>

#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";