1 // SPDX-License-Identifier: GPL-2.0
2 #include "vmlinux.h"
3 #include <bpf/bpf_helpers.h>
4 
5 char _license[] SEC("license") = "GPL";
6 
7 struct {
8 	__uint(type, BPF_MAP_TYPE_ARRAY);
9 	__uint(max_entries, 3);
10 	__type(key, __u32);
11 	__type(value, __u64);
12 } arraymap SEC(".maps");
13 
14 struct {
15 	__uint(type, BPF_MAP_TYPE_HASH);
16 	__uint(max_entries, 5);
17 	__type(key, __u32);
18 	__type(value, __u64);
19 } hashmap SEC(".maps");
20 
21 struct callback_ctx {
22 	int output;
23 };
24 
25 u32 data_output = 0;
26 int use_array = 0;
27 
28 static __u64
29 check_map_elem(struct bpf_map *map, __u32 *key, __u64 *val,
30 	       struct callback_ctx *data)
31 {
32 	data->output += *val;
33 	return 0;
34 }
35 
36 SEC("tc")
37 int test_pkt_access(struct __sk_buff *skb)
38 {
39 	struct callback_ctx data;
40 
41 	data.output = 0;
42 	if (use_array)
43 		bpf_for_each_map_elem(&arraymap, check_map_elem, &data, 0);
44 	else
45 		bpf_for_each_map_elem(&hashmap, check_map_elem, &data, 0);
46 	data_output = data.output;
47 
48 	return 0;
49 }
50