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, 5);
9 __uint(key_size, sizeof(__u32));
10 __uint(value_size, sizeof(__u32));
11} jmp_table SEC(".maps");
12
13SEC("tc")
14int classifier_0(struct __sk_buff *skb)
15{
16 bpf_tail_call_static(skb, &jmp_table, 1);
17 return 0;
18}
19
20SEC("tc")
21int classifier_1(struct __sk_buff *skb)
22{
23 bpf_tail_call_static(skb, &jmp_table, 2);
24 return 1;
25}
26
27SEC("tc")
28int classifier_2(struct __sk_buff *skb)
29{
30 return 2;
31}
32
33SEC("tc")
34int classifier_3(struct __sk_buff *skb)
35{
36 bpf_tail_call_static(skb, &jmp_table, 4);
37 return 3;
38}
39
40SEC("tc")
41int classifier_4(struct __sk_buff *skb)
42{
43 bpf_tail_call_static(skb, &jmp_table, 3);
44 return 4;
45}
46
47SEC("tc")
48int entry(struct __sk_buff *skb)
49{
50 bpf_tail_call_static(skb, &jmp_table, 0);
51 /* Check multi-prog update. */
52 bpf_tail_call_static(skb, &jmp_table, 2);
53 /* Check tail call limit. */
54 bpf_tail_call_static(skb, &jmp_table, 3);
55 return 3;
56}
57
58char __license[] SEC("license") = "GPL";
59

source code of linux/tools/testing/selftests/bpf/progs/tailcall2.c