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 
9 const volatile pid_t my_pid = 0;
10 char path[256] = {};
11 
12 SEC("fentry/unix_listen")
BPF_PROG(unix_listen,struct socket * sock,int backlog)13 int 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 >= sizeof(struct sockaddr_un))
33 			break;
34 
35 		path[i] = unix_sk->addr->name->sun_path[i];
36 	}
37 	return 0;
38 }
39 
40 char _license[] SEC("license") = "GPL";
41