1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/bpf.h>
3*4882a593Smuzhiyun #include <bpf/bpf_helpers.h>
4*4882a593Smuzhiyun #include "bpf_legacy.h"
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun struct {
7*4882a593Smuzhiyun __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
8*4882a593Smuzhiyun __uint(max_entries, 1);
9*4882a593Smuzhiyun __uint(key_size, sizeof(__u32));
10*4882a593Smuzhiyun __uint(value_size, sizeof(__u32));
11*4882a593Smuzhiyun } jmp_table SEC(".maps");
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun static __noinline
subprog_tail(struct __sk_buff * skb)14*4882a593Smuzhiyun int subprog_tail(struct __sk_buff *skb)
15*4882a593Smuzhiyun {
16*4882a593Smuzhiyun if (load_byte(skb, 0))
17*4882a593Smuzhiyun bpf_tail_call_static(skb, &jmp_table, 1);
18*4882a593Smuzhiyun else
19*4882a593Smuzhiyun bpf_tail_call_static(skb, &jmp_table, 0);
20*4882a593Smuzhiyun return 1;
21*4882a593Smuzhiyun }
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun static volatile int count;
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun SEC("classifier/0")
bpf_func_0(struct __sk_buff * skb)26*4882a593Smuzhiyun int bpf_func_0(struct __sk_buff *skb)
27*4882a593Smuzhiyun {
28*4882a593Smuzhiyun count++;
29*4882a593Smuzhiyun return subprog_tail(skb);
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun SEC("classifier")
entry(struct __sk_buff * skb)33*4882a593Smuzhiyun int entry(struct __sk_buff *skb)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun bpf_tail_call_static(skb, &jmp_table, 0);
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun return 0;
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun char __license[] SEC("license") = "GPL";
41*4882a593Smuzhiyun int _version SEC("version") = 1;
42