1/* SPDX-License-Identifier: GPL-2.0 */
2/* Copyright (c) 2021 Hengqi Chen */
3
4#include "vmlinux.h"
5#include <bpf/bpf_helpers.h>
6#include <bpf/bpf_tracing.h>
7#include "bpf_tracing_net.h"
8
9const volatile pid_t my_pid = 0;
10char path[256] = {};
11
12SEC("fentry/unix_listen")
13int BPF_PROG(unix_listen, struct socket *sock, int backlog)
14{
15	pid_t pid = bpf_get_current_pid_tgid() >> 32;
16	struct unix_sock *unix_sk;
17	int i, len;
18
19	if (pid != my_pid)
20		return 0;
21
22	unix_sk = (struct unix_sock *)bpf_skc_to_unix_sock(sock->sk);
23	if (!unix_sk)
24		return 0;
25
26	if (unix_sk->addr->name->sun_path[0])
27		return 0;
28
29	len = unix_sk->addr->len - sizeof(short);
30	path[0] = '@';
31	for (i = 1; i < len; i++) {
32		if (i >= (int)sizeof(struct sockaddr_un))
33			break;
34
35		path[i] = unix_sk->addr->name->sun_path[i];
36	}
37	return 0;
38}
39
40char _license[] SEC("license") = "GPL";
41