| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2021 Facebook */ |
| #include "vmlinux.h" |
| #include <bpf/bpf_helpers.h> |
| |
| char _license[] SEC("license") = "GPL"; |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_ARRAY); |
| __uint(max_entries, 3); |
| __type(key, __u32); |
| __type(value, __u64); |
| } arraymap SEC(".maps"); |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); |
| __uint(max_entries, 1); |
| __type(key, __u32); |
| __type(value, __u64); |
| } percpu_map SEC(".maps"); |
| |
| struct callback_ctx { |
| int output; |
| }; |
| |
| const volatile int bypass_unused = 1; |
| |
| static __u64 |
| unused_subprog(struct bpf_map *map, __u32 *key, __u64 *val, |
| struct callback_ctx *data) |
| { |
| data->output = 0; |
| return 1; |
| } |
| |
| static __u64 |
| check_array_elem(struct bpf_map *map, __u32 *key, __u64 *val, |
| struct callback_ctx *data) |
| { |
| data->output += *val; |
| if (*key == 1) |
| return 1; /* stop the iteration */ |
| return 0; |
| } |
| |
| __u32 cpu = 0; |
| __u64 percpu_val = 0; |
| |
| static __u64 |
| check_percpu_elem(struct bpf_map *map, __u32 *key, __u64 *val, |
| struct callback_ctx *data) |
| { |
| cpu = bpf_get_smp_processor_id(); |
| percpu_val = *val; |
| return 0; |
| } |
| |
| u32 arraymap_output = 0; |
| |
| SEC("tc") |
| int test_pkt_access(struct __sk_buff *skb) |
| { |
| struct callback_ctx data; |
| |
| data.output = 0; |
| bpf_for_each_map_elem(&arraymap, check_array_elem, &data, 0); |
| if (!bypass_unused) |
| bpf_for_each_map_elem(&arraymap, unused_subprog, &data, 0); |
| arraymap_output = data.output; |
| |
| bpf_for_each_map_elem(&percpu_map, check_percpu_elem, (void *)0, 0); |
| return 0; |
| } |