1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020 Facebook */
3#include "bpf_iter.h"
4#include <bpf/bpf_helpers.h>
5
6char _license[] SEC("license") = "GPL";
7
8__u32 map1_id = 0, map2_id = 0;
9__u32 map1_accessed = 0, map2_accessed = 0;
10__u64 map1_seqnum = 0, map2_seqnum1 = 0, map2_seqnum2 = 0;
11
12volatile const __u32 print_len;
13volatile const __u32 ret1;
14
15SEC("iter/bpf_map")
16int dump_bpf_map(struct bpf_iter__bpf_map *ctx)
17{
18	struct seq_file *seq = ctx->meta->seq;
19	struct bpf_map *map = ctx->map;
20	__u64 seq_num;
21	int i, ret = 0;
22
23	if (map == (void *)0)
24		return 0;
25
26	/* only dump map1_id and map2_id */
27	if (map->id != map1_id && map->id != map2_id)
28		return 0;
29
30	seq_num = ctx->meta->seq_num;
31	if (map->id == map1_id) {
32		map1_seqnum = seq_num;
33		map1_accessed++;
34	}
35
36	if (map->id == map2_id) {
37		if (map2_accessed == 0) {
38			map2_seqnum1 = seq_num;
39			if (ret1)
40				ret = 1;
41		} else {
42			map2_seqnum2 = seq_num;
43		}
44		map2_accessed++;
45	}
46
47	/* fill seq_file buffer */
48	for (i = 0; i < (int)print_len; i++)
49		bpf_seq_write(seq, &seq_num, sizeof(seq_num));
50
51	return ret;
52}
53