1/* SPDX-License-Identifier: GPL-2.0 */
2/* Copyright (c) 2020 Facebook */
3#include <linux/bpf.h>
4#include <bpf/bpf_helpers.h>
5
6struct inner_map {
7	__uint(type, BPF_MAP_TYPE_ARRAY);
8	__uint(max_entries, 1);
9	__type(key, int);
10	__type(value, int);
11} inner_map1 SEC(".maps"),
12  inner_map2 SEC(".maps");
13
14struct inner_map_sz2 {
15	__uint(type, BPF_MAP_TYPE_ARRAY);
16	__uint(max_entries, 2);
17	__type(key, int);
18	__type(value, int);
19} inner_map_sz2 SEC(".maps");
20
21struct outer_arr {
22	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
23	__uint(max_entries, 3);
24	__type(key, int);
25	__type(value, int);
26	/* it's possible to use anonymous struct as inner map definition here */
27	__array(values, struct {
28		__uint(type, BPF_MAP_TYPE_ARRAY);
29		/* changing max_entries to 2 will fail during load
30		 * due to incompatibility with inner_map definition */
31		__uint(max_entries, 1);
32		__type(key, int);
33		__type(value, int);
34	});
35} outer_arr SEC(".maps") = {
36	/* (void *) cast is necessary because we didn't use `struct inner_map`
37	 * in __inner(values, ...)
38	 * Actually, a conscious effort is required to screw up initialization
39	 * of inner map slots, which is a great thing!
40	 */
41	.values = { (void *)&inner_map1, 0, (void *)&inner_map2 },
42};
43
44struct inner_map_sz3 {
45	__uint(type, BPF_MAP_TYPE_ARRAY);
46	__uint(map_flags, BPF_F_INNER_MAP);
47	__uint(max_entries, 3);
48	__type(key, int);
49	__type(value, int);
50} inner_map3 SEC(".maps"),
51  inner_map4 SEC(".maps");
52
53struct inner_map_sz4 {
54	__uint(type, BPF_MAP_TYPE_ARRAY);
55	__uint(map_flags, BPF_F_INNER_MAP);
56	__uint(max_entries, 5);
57	__type(key, int);
58	__type(value, int);
59} inner_map5 SEC(".maps");
60
61struct outer_arr_dyn {
62	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
63	__uint(max_entries, 3);
64	__type(key, int);
65	__type(value, int);
66	__array(values, struct {
67		__uint(type, BPF_MAP_TYPE_ARRAY);
68		__uint(map_flags, BPF_F_INNER_MAP);
69		__uint(max_entries, 1);
70		__type(key, int);
71		__type(value, int);
72	});
73} outer_arr_dyn SEC(".maps") = {
74	.values = {
75		[0] = (void *)&inner_map3,
76		[1] = (void *)&inner_map4,
77		[2] = (void *)&inner_map5,
78	},
79};
80
81struct outer_hash {
82	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
83	__uint(max_entries, 5);
84	__type(key, int);
85	/* Here everything works flawlessly due to reuse of struct inner_map
86	 * and compiler will complain at the attempt to use non-inner_map
87	 * references below. This is great experience.
88	 */
89	__array(values, struct inner_map);
90} outer_hash SEC(".maps") = {
91	.values = {
92		[0] = &inner_map2,
93		[4] = &inner_map1,
94	},
95};
96
97struct sockarr_sz1 {
98	__uint(type, BPF_MAP_TYPE_REUSEPORT_SOCKARRAY);
99	__uint(max_entries, 1);
100	__type(key, int);
101	__type(value, int);
102} sockarr_sz1 SEC(".maps");
103
104struct sockarr_sz2 {
105	__uint(type, BPF_MAP_TYPE_REUSEPORT_SOCKARRAY);
106	__uint(max_entries, 2);
107	__type(key, int);
108	__type(value, int);
109} sockarr_sz2 SEC(".maps");
110
111struct outer_sockarr_sz1 {
112	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
113	__uint(max_entries, 1);
114	__type(key, int);
115	__type(value, int);
116	__array(values, struct sockarr_sz1);
117} outer_sockarr SEC(".maps") = {
118	.values = { (void *)&sockarr_sz1 },
119};
120
121int input = 0;
122
123SEC("raw_tp/sys_enter")
124int handle__sys_enter(void *ctx)
125{
126	struct inner_map *inner_map;
127	int key = 0, val;
128
129	inner_map = bpf_map_lookup_elem(&outer_arr, &key);
130	if (!inner_map)
131		return 1;
132	val = input;
133	bpf_map_update_elem(inner_map, &key, &val, 0);
134
135	inner_map = bpf_map_lookup_elem(&outer_hash, &key);
136	if (!inner_map)
137		return 1;
138	val = input + 1;
139	bpf_map_update_elem(inner_map, &key, &val, 0);
140
141	inner_map = bpf_map_lookup_elem(&outer_arr_dyn, &key);
142	if (!inner_map)
143		return 1;
144	val = input + 2;
145	bpf_map_update_elem(inner_map, &key, &val, 0);
146
147	return 0;
148}
149
150char _license[] SEC("license") = "GPL";
151