1 #include <uapi/linux/bpf.h>
2 #include <linux/socket.h>
3 #include <linux/net.h>
4 #include <uapi/linux/in.h>
5 #include <uapi/linux/in6.h>
6 #include <bpf/bpf_helpers.h>
7 
8 SEC("cgroup/sock1")
bpf_prog1(struct bpf_sock * sk)9 int bpf_prog1(struct bpf_sock *sk)
10 {
11 	char fmt[] = "socket: family %d type %d protocol %d\n";
12 	char fmt2[] = "socket: uid %u gid %u\n";
13 	__u64 gid_uid = bpf_get_current_uid_gid();
14 	__u32 uid = gid_uid & 0xffffffff;
15 	__u32 gid = gid_uid >> 32;
16 
17 	bpf_trace_printk(fmt, sizeof(fmt), sk->family, sk->type, sk->protocol);
18 	bpf_trace_printk(fmt2, sizeof(fmt2), uid, gid);
19 
20 	/* block PF_INET6, SOCK_RAW, IPPROTO_ICMPV6 sockets
21 	 * ie., make ping6 fail
22 	 */
23 	if (sk->family == PF_INET6 &&
24 	    sk->type == SOCK_RAW   &&
25 	    sk->protocol == IPPROTO_ICMPV6)
26 		return 0;
27 
28 	return 1;
29 }
30 
31 SEC("cgroup/sock2")
bpf_prog2(struct bpf_sock * sk)32 int bpf_prog2(struct bpf_sock *sk)
33 {
34 	char fmt[] = "socket: family %d type %d protocol %d\n";
35 
36 	bpf_trace_printk(fmt, sizeof(fmt), sk->family, sk->type, sk->protocol);
37 
38 	/* block PF_INET, SOCK_RAW, IPPROTO_ICMP sockets
39 	 * ie., make ping fail
40 	 */
41 	if (sk->family == PF_INET &&
42 	    sk->type == SOCK_RAW  &&
43 	    sk->protocol == IPPROTO_ICMP)
44 		return 0;
45 
46 	return 1;
47 }
48 
49 char _license[] SEC("license") = "GPL";
50