1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (c) 2021 Facebook */ |
3 | #include "vmlinux.h" |
4 | #include <bpf/bpf_helpers.h> |
5 | |
6 | char _license[] SEC("license" ) = "GPL" ; |
7 | |
8 | struct { |
9 | __uint(type, BPF_MAP_TYPE_ARRAY); |
10 | __uint(max_entries, 3); |
11 | __type(key, __u32); |
12 | __type(value, __u64); |
13 | } arraymap SEC(".maps" ); |
14 | |
15 | struct { |
16 | __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); |
17 | __uint(max_entries, 1); |
18 | __type(key, __u32); |
19 | __type(value, __u64); |
20 | } percpu_map SEC(".maps" ); |
21 | |
22 | struct callback_ctx { |
23 | int output; |
24 | }; |
25 | |
26 | const volatile int bypass_unused = 1; |
27 | |
28 | static __u64 |
29 | unused_subprog(struct bpf_map *map, __u32 *key, __u64 *val, |
30 | struct callback_ctx *data) |
31 | { |
32 | data->output = 0; |
33 | return 1; |
34 | } |
35 | |
36 | static __u64 |
37 | check_array_elem(struct bpf_map *map, __u32 *key, __u64 *val, |
38 | struct callback_ctx *data) |
39 | { |
40 | data->output += *val; |
41 | if (*key == 1) |
42 | return 1; /* stop the iteration */ |
43 | return 0; |
44 | } |
45 | |
46 | __u32 cpu = 0; |
47 | __u64 percpu_val = 0; |
48 | |
49 | static __u64 |
50 | check_percpu_elem(struct bpf_map *map, __u32 *key, __u64 *val, |
51 | struct callback_ctx *data) |
52 | { |
53 | cpu = bpf_get_smp_processor_id(); |
54 | percpu_val = *val; |
55 | return 0; |
56 | } |
57 | |
58 | u32 arraymap_output = 0; |
59 | |
60 | SEC("tc" ) |
61 | int test_pkt_access(struct __sk_buff *skb) |
62 | { |
63 | struct callback_ctx data; |
64 | |
65 | data.output = 0; |
66 | bpf_for_each_map_elem(&arraymap, check_array_elem, &data, 0); |
67 | if (!bypass_unused) |
68 | bpf_for_each_map_elem(&arraymap, unused_subprog, &data, 0); |
69 | arraymap_output = data.output; |
70 | |
71 | bpf_for_each_map_elem(&percpu_map, check_percpu_elem, (void *)0, 0); |
72 | return 0; |
73 | } |
74 | |