1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2021 Facebook */
3
4#include <linux/bpf.h>
5#include <bpf/bpf_helpers.h>
6#include "bpf_misc.h"
7
8char _license[] SEC("license") = "GPL";
9
10struct bpf_map;
11
12struct {
13 __uint(type, BPF_MAP_TYPE_ARRAY);
14 __type(key, __u32);
15 __type(value, __u32);
16 __uint(max_entries, 1000);
17} map_random_data SEC(".maps");
18
19struct map_bloom_type {
20 __uint(type, BPF_MAP_TYPE_BLOOM_FILTER);
21 __type(value, __u32);
22 __uint(max_entries, 10000);
23 __uint(map_extra, 5);
24} map_bloom SEC(".maps");
25
26struct {
27 __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
28 __type(key, int);
29 __type(value, int);
30 __uint(max_entries, 1);
31 __array(values, struct map_bloom_type);
32} outer_map SEC(".maps");
33
34struct callback_ctx {
35 struct bpf_map *map;
36};
37
38int error = 0;
39
40static __u64
41check_elem(struct bpf_map *map, __u32 *key, __u32 *val,
42 struct callback_ctx *data)
43{
44 int err;
45
46 err = bpf_map_peek_elem(data->map, val);
47 if (err) {
48 error |= 1;
49 return 1; /* stop the iteration */
50 }
51
52 return 0;
53}
54
55SEC("fentry/" SYS_PREFIX "sys_getpgid")
56int inner_map(void *ctx)
57{
58 struct bpf_map *inner_map;
59 struct callback_ctx data;
60 int key = 0;
61
62 inner_map = bpf_map_lookup_elem(&outer_map, &key);
63 if (!inner_map) {
64 error |= 2;
65 return 0;
66 }
67
68 data.map = inner_map;
69 bpf_for_each_map_elem(&map_random_data, check_elem, &data, 0);
70
71 return 0;
72}
73
74SEC("fentry/" SYS_PREFIX "sys_getpgid")
75int check_bloom(void *ctx)
76{
77 struct callback_ctx data;
78
79 data.map = (struct bpf_map *)&map_bloom;
80 bpf_for_each_map_elem(&map_random_data, check_elem, &data, 0);
81
82 return 0;
83}
84

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