1// SPDX-License-Identifier: GPL-2.0
2#include <linux/bpf.h>
3#include <bpf/bpf_helpers.h>
4#include "bpf_legacy.h"
5
6struct {
7	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
8	__uint(max_entries, 1);
9	__uint(key_size, sizeof(__u32));
10	__uint(value_size, sizeof(__u32));
11} jmp_table SEC(".maps");
12
13static __noinline
14int subprog_tail(struct __sk_buff *skb)
15{
16	if (load_byte(skb, 0))
17		bpf_tail_call_static(skb, &jmp_table, 1);
18	else
19		bpf_tail_call_static(skb, &jmp_table, 0);
20	return 1;
21}
22
23int count = 0;
24
25SEC("tc")
26int classifier_0(struct __sk_buff *skb)
27{
28	count++;
29	return subprog_tail(skb);
30}
31
32SEC("tc")
33int entry(struct __sk_buff *skb)
34{
35	bpf_tail_call_static(skb, &jmp_table, 0);
36
37	return 0;
38}
39
40char __license[] SEC("license") = "GPL";
41