1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/bpf.h>
 3
 4#include <bpf/bpf_helpers.h>
 5
 6struct {
 7	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
 8	__uint(max_entries, 3);
 9	__uint(key_size, sizeof(__u32));
10	__uint(value_size, sizeof(__u32));
11} jmp_table SEC(".maps");
12
13int selector = 0;
14
15#define TAIL_FUNC(x)				\
16	SEC("classifier/" #x)			\
17	int bpf_func_##x(struct __sk_buff *skb)	\
18	{					\
19		return x;			\
20	}
21TAIL_FUNC(0)
22TAIL_FUNC(1)
23TAIL_FUNC(2)
24
25SEC("classifier")
26int entry(struct __sk_buff *skb)
27{
28	int idx = 0;
29
30	if (selector == 1234)
31		idx = 1;
32	else if (selector == 5678)
33		idx = 2;
34
35	bpf_tail_call(skb, &jmp_table, idx);
36	return 3;
37}
38
39char __license[] SEC("license") = "GPL";
40int _version SEC("version") = 1;