| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2021 Facebook */ |
| |
| #include <linux/bpf.h> |
| #include <bpf/bpf_helpers.h> |
| |
| char _license[] SEC("license") = "GPL"; |
| |
| struct bpf_map; |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_ARRAY); |
| __type(key, __u32); |
| __type(value, __u32); |
| __uint(max_entries, 1000); |
| } map_random_data SEC(".maps"); |
| |
| struct map_bloom_type { |
| __uint(type, BPF_MAP_TYPE_BLOOM_FILTER); |
| __type(value, __u32); |
| __uint(max_entries, 10000); |
| __uint(map_extra, 5); |
| } map_bloom SEC(".maps"); |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS); |
| __type(key, int); |
| __type(value, int); |
| __uint(max_entries, 1); |
| __array(values, struct map_bloom_type); |
| } outer_map SEC(".maps"); |
| |
| struct callback_ctx { |
| struct bpf_map *map; |
| }; |
| |
| int error = 0; |
| |
| static __u64 |
| check_elem(struct bpf_map *map, __u32 *key, __u32 *val, |
| struct callback_ctx *data) |
| { |
| int err; |
| |
| err = bpf_map_peek_elem(data->map, val); |
| if (err) { |
| error |= 1; |
| return 1; /* stop the iteration */ |
| } |
| |
| return 0; |
| } |
| |
| SEC("fentry/__x64_sys_getpgid") |
| int inner_map(void *ctx) |
| { |
| struct bpf_map *inner_map; |
| struct callback_ctx data; |
| int key = 0; |
| |
| inner_map = bpf_map_lookup_elem(&outer_map, &key); |
| if (!inner_map) { |
| error |= 2; |
| return 0; |
| } |
| |
| data.map = inner_map; |
| bpf_for_each_map_elem(&map_random_data, check_elem, &data, 0); |
| |
| return 0; |
| } |
| |
| SEC("fentry/__x64_sys_getpgid") |
| int check_bloom(void *ctx) |
| { |
| struct callback_ctx data; |
| |
| data.map = (struct bpf_map *)&map_bloom; |
| bpf_for_each_map_elem(&map_random_data, check_elem, &data, 0); |
| |
| return 0; |
| } |