| Daniel Borkmann | 79d49ba | 2019-11-22 21:08:01 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | #include <linux/bpf.h> |
| 3 | |
| 4 | #include "bpf_helpers.h" |
| 5 | |
| 6 | struct { |
| 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 | |
| 13 | #define TAIL_FUNC(x) \ |
| 14 | SEC("classifier/" #x) \ |
| 15 | int bpf_func_##x(struct __sk_buff *skb) \ |
| 16 | { \ |
| 17 | return x; \ |
| 18 | } |
| 19 | TAIL_FUNC(0) |
| 20 | TAIL_FUNC(1) |
| 21 | TAIL_FUNC(2) |
| 22 | |
| 23 | SEC("classifier") |
| 24 | int entry(struct __sk_buff *skb) |
| 25 | { |
| 26 | /* Multiple locations to make sure we patch |
| 27 | * all of them. |
| 28 | */ |
| 29 | bpf_tail_call(skb, &jmp_table, 0); |
| 30 | bpf_tail_call(skb, &jmp_table, 0); |
| 31 | bpf_tail_call(skb, &jmp_table, 0); |
| 32 | bpf_tail_call(skb, &jmp_table, 0); |
| 33 | |
| 34 | bpf_tail_call(skb, &jmp_table, 1); |
| 35 | bpf_tail_call(skb, &jmp_table, 1); |
| 36 | bpf_tail_call(skb, &jmp_table, 1); |
| 37 | bpf_tail_call(skb, &jmp_table, 1); |
| 38 | |
| 39 | bpf_tail_call(skb, &jmp_table, 2); |
| 40 | bpf_tail_call(skb, &jmp_table, 2); |
| 41 | bpf_tail_call(skb, &jmp_table, 2); |
| 42 | bpf_tail_call(skb, &jmp_table, 2); |
| 43 | |
| 44 | return 3; |
| 45 | } |
| 46 | |
| 47 | char __license[] SEC("license") = "GPL"; |
| 48 | int _version SEC("version") = 1; |