1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bpf.h>
3 #include <bpf/bpf_helpers.h>
4 #include "bpf_legacy.h"
5 #include "bpf_misc.h"
6
7 struct {
8 __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
9 __uint(max_entries, 2);
10 __uint(key_size, sizeof(__u32));
11 __uint(value_size, sizeof(__u32));
12 } jmp_table SEC(".maps");
13
14 __noinline
subprog_tail2(struct __sk_buff * skb)15 int subprog_tail2(struct __sk_buff *skb)
16 {
17 volatile char arr[64] = {};
18
19 if (load_word(skb, 0) || load_half(skb, 0))
20 bpf_tail_call_static(skb, &jmp_table, 10);
21 else
22 bpf_tail_call_static(skb, &jmp_table, 1);
23
24 __sink(arr[sizeof(arr) - 1]);
25
26 return skb->len;
27 }
28
29 static __noinline
subprog_tail(struct __sk_buff * skb)30 int subprog_tail(struct __sk_buff *skb)
31 {
32 volatile char arr[64] = {};
33
34 bpf_tail_call_static(skb, &jmp_table, 0);
35
36 __sink(arr[sizeof(arr) - 1]);
37
38 return skb->len * 2;
39 }
40
41 SEC("tc")
classifier_0(struct __sk_buff * skb)42 int classifier_0(struct __sk_buff *skb)
43 {
44 volatile char arr[128] = {};
45
46 __sink(arr[sizeof(arr) - 1]);
47
48 return subprog_tail2(skb);
49 }
50
51 SEC("tc")
classifier_1(struct __sk_buff * skb)52 int classifier_1(struct __sk_buff *skb)
53 {
54 volatile char arr[128] = {};
55
56 __sink(arr[sizeof(arr) - 1]);
57
58 return skb->len * 3;
59 }
60
61 SEC("tc")
entry(struct __sk_buff * skb)62 int entry(struct __sk_buff *skb)
63 {
64 volatile char arr[128] = {};
65
66 __sink(arr[sizeof(arr) - 1]);
67
68 return subprog_tail(skb);
69 }
70
71 char __license[] SEC("license") = "GPL";
72