1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bpf.h>
3 
4 #include <bpf/bpf_helpers.h>
5 
6 struct {
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 
13 int count, which;
14 
15 SEC("tc")
16 int classifier_0(struct __sk_buff *skb)
17 {
18 	count++;
19 	if (__builtin_constant_p(which))
20 		__bpf_unreachable();
21 	bpf_tail_call(skb, &jmp_table, which);
22 	return 1;
23 }
24 
25 SEC("tc")
26 int entry(struct __sk_buff *skb)
27 {
28 	if (__builtin_constant_p(which))
29 		__bpf_unreachable();
30 	bpf_tail_call(skb, &jmp_table, which);
31 	return 0;
32 }
33 
34 char __license[] SEC("license") = "GPL";
35