xref: /OK3568_Linux_fs/kernel/tools/testing/selftests/bpf/progs/tailcall5.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/bpf.h>
3*4882a593Smuzhiyun 
4*4882a593Smuzhiyun #include <bpf/bpf_helpers.h>
5*4882a593Smuzhiyun 
6*4882a593Smuzhiyun struct {
7*4882a593Smuzhiyun 	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
8*4882a593Smuzhiyun 	__uint(max_entries, 3);
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 volatile int selector;
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun #define TAIL_FUNC(x)				\
16*4882a593Smuzhiyun 	SEC("classifier/" #x)			\
17*4882a593Smuzhiyun 	int bpf_func_##x(struct __sk_buff *skb)	\
18*4882a593Smuzhiyun 	{					\
19*4882a593Smuzhiyun 		return x;			\
20*4882a593Smuzhiyun 	}
21*4882a593Smuzhiyun TAIL_FUNC(0)
22*4882a593Smuzhiyun TAIL_FUNC(1)
23*4882a593Smuzhiyun TAIL_FUNC(2)
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun SEC("classifier")
entry(struct __sk_buff * skb)26*4882a593Smuzhiyun int entry(struct __sk_buff *skb)
27*4882a593Smuzhiyun {
28*4882a593Smuzhiyun 	int idx = 0;
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun 	if (selector == 1234)
31*4882a593Smuzhiyun 		idx = 1;
32*4882a593Smuzhiyun 	else if (selector == 5678)
33*4882a593Smuzhiyun 		idx = 2;
34*4882a593Smuzhiyun 
35*4882a593Smuzhiyun 	bpf_tail_call(skb, &jmp_table, idx);
36*4882a593Smuzhiyun 	return 3;
37*4882a593Smuzhiyun }
38*4882a593Smuzhiyun 
39*4882a593Smuzhiyun char __license[] SEC("license") = "GPL";
40*4882a593Smuzhiyun int _version SEC("version") = 1;
41