1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2021 Facebook */
3 #include <linux/bpf.h>
4 #include <time.h>
5 #include <errno.h>
6 #include <bpf/bpf_helpers.h>
7 #include <bpf/bpf_tracing.h>
8
9 char _license[] SEC("license") = "GPL";
10 struct hmap_elem {
11 int pad; /* unused */
12 struct bpf_timer timer;
13 };
14
15 struct inner_map {
16 __uint(type, BPF_MAP_TYPE_HASH);
17 __uint(max_entries, 1024);
18 __type(key, int);
19 __type(value, struct hmap_elem);
20 } inner_htab SEC(".maps");
21
22 #define ARRAY_KEY 1
23 #define ARRAY_KEY2 2
24 #define HASH_KEY 1234
25
26 struct outer_arr {
27 __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
28 __uint(max_entries, 2);
29 __uint(key_size, sizeof(int));
30 __uint(value_size, sizeof(int));
31 __array(values, struct inner_map);
32 } outer_arr SEC(".maps") = {
33 .values = { [ARRAY_KEY] = &inner_htab },
34 };
35
36 __u64 err;
37 __u64 ok;
38 __u64 cnt;
39
40 /* callback for inner hash map */
timer_cb(void * map,int * key,struct hmap_elem * val)41 static int timer_cb(void *map, int *key, struct hmap_elem *val)
42 {
43 return 0;
44 }
45
46 SEC("?fentry/bpf_fentry_test1")
BPF_PROG(test1,int a)47 int BPF_PROG(test1, int a)
48 {
49 struct hmap_elem init = {};
50 struct bpf_map *inner_map, *inner_map2;
51 struct hmap_elem *val;
52 int array_key = ARRAY_KEY;
53 int array_key2 = ARRAY_KEY2;
54 int hash_key = HASH_KEY;
55
56 inner_map = bpf_map_lookup_elem(&outer_arr, &array_key);
57 if (!inner_map)
58 return 0;
59
60 inner_map2 = bpf_map_lookup_elem(&outer_arr, &array_key2);
61 if (!inner_map2)
62 return 0;
63 bpf_map_update_elem(inner_map, &hash_key, &init, 0);
64 val = bpf_map_lookup_elem(inner_map, &hash_key);
65 if (!val)
66 return 0;
67
68 bpf_timer_init(&val->timer, inner_map2, CLOCK_MONOTONIC);
69 if (bpf_timer_set_callback(&val->timer, timer_cb))
70 err |= 4;
71 if (bpf_timer_start(&val->timer, 0, 0))
72 err |= 8;
73 return 0;
74 }
75
76 struct callback_ctx {
77 void *map;
78 };
79
mismatch_iter_cb(void * map,int * key,struct hmap_elem * val,struct callback_ctx * ctx)80 static int mismatch_iter_cb(void *map, int *key, struct hmap_elem *val, struct callback_ctx *ctx)
81 {
82 bpf_timer_init(&val->timer, ctx->map, CLOCK_MONOTONIC);
83 return 0;
84 }
85
timer_mismatch_cb(void * map,int * key,struct hmap_elem * val)86 static int timer_mismatch_cb(void *map, int *key, struct hmap_elem *val)
87 {
88 struct callback_ctx ctx = { .map = map };
89 struct bpf_map *inner_map2;
90 int array_key2 = ARRAY_KEY2;
91
92 inner_map2 = bpf_map_lookup_elem(&outer_arr, &array_key2);
93 if (!inner_map2)
94 return 0;
95 bpf_for_each_map_elem(inner_map2, mismatch_iter_cb, &ctx, 0);
96 return 0;
97 }
98
match_iter_cb(void * map,int * key,struct hmap_elem * val,struct callback_ctx * ctx)99 static int match_iter_cb(void *map, int *key, struct hmap_elem *val, struct callback_ctx *ctx)
100 {
101 bpf_timer_init(&val->timer, map, CLOCK_MONOTONIC);
102 return 0;
103 }
104
timer_match_cb(void * map,int * key,struct hmap_elem * val)105 static int timer_match_cb(void *map, int *key, struct hmap_elem *val)
106 {
107 struct callback_ctx ctx = {};
108 struct bpf_map *inner_map2;
109 int array_key2 = ARRAY_KEY2;
110
111 inner_map2 = bpf_map_lookup_elem(&outer_arr, &array_key2);
112 if (!inner_map2)
113 return 0;
114 bpf_for_each_map_elem(inner_map2, match_iter_cb, &ctx, 0);
115 return 0;
116 }
117
118 SEC("?fentry/bpf_fentry_test1")
BPF_PROG(callback_map_uid_mismatch,int a)119 int BPF_PROG(callback_map_uid_mismatch, int a)
120 {
121 struct hmap_elem *val;
122 struct bpf_map *inner_map;
123 int array_key = ARRAY_KEY;
124 int hash_key = HASH_KEY;
125
126 inner_map = bpf_map_lookup_elem(&outer_arr, &array_key);
127 if (!inner_map)
128 return 0;
129 val = bpf_map_lookup_elem(inner_map, &hash_key);
130 if (!val)
131 return 0;
132
133 bpf_timer_init(&val->timer, inner_map, CLOCK_MONOTONIC);
134 bpf_timer_set_callback(&val->timer, timer_mismatch_cb);
135 return 0;
136 }
137
138 SEC("?fentry/bpf_fentry_test1")
BPF_PROG(callback_map_uid_match,int a)139 int BPF_PROG(callback_map_uid_match, int a)
140 {
141 struct hmap_elem *val;
142 struct bpf_map *inner_map;
143 int array_key = ARRAY_KEY;
144 int hash_key = HASH_KEY;
145
146 inner_map = bpf_map_lookup_elem(&outer_arr, &array_key);
147 if (!inner_map)
148 return 0;
149 val = bpf_map_lookup_elem(inner_map, &hash_key);
150 if (!val)
151 return 0;
152
153 bpf_timer_init(&val->timer, inner_map, CLOCK_MONOTONIC);
154 bpf_timer_set_callback(&val->timer, timer_match_cb);
155 return 0;
156 }
157