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56f668df MKL |
1 | /* Copyright (c) 2017 Facebook |
2 | * | |
3 | * This program is free software; you can redistribute it and/or | |
4 | * modify it under the terms of version 2 of the GNU General Public | |
5 | * License as published by the Free Software Foundation. | |
6 | */ | |
7 | #include <linux/slab.h> | |
8 | #include <linux/bpf.h> | |
9 | ||
10 | #include "map_in_map.h" | |
11 | ||
12 | struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) | |
13 | { | |
14 | struct bpf_map *inner_map, *inner_map_meta; | |
15 | struct fd f; | |
16 | ||
17 | f = fdget(inner_map_ufd); | |
18 | inner_map = __bpf_map_get(f); | |
19 | if (IS_ERR(inner_map)) | |
20 | return inner_map; | |
21 | ||
22 | /* prog_array->owner_prog_type and owner_jited | |
23 | * is a runtime binding. Doing static check alone | |
24 | * in the verifier is not enough. | |
25 | */ | |
26 | if (inner_map->map_type == BPF_MAP_TYPE_PROG_ARRAY) { | |
27 | fdput(f); | |
28 | return ERR_PTR(-ENOTSUPP); | |
29 | } | |
30 | ||
31 | /* Does not support >1 level map-in-map */ | |
32 | if (inner_map->inner_map_meta) { | |
33 | fdput(f); | |
34 | return ERR_PTR(-EINVAL); | |
35 | } | |
36 | ||
37 | inner_map_meta = kzalloc(sizeof(*inner_map_meta), GFP_USER); | |
38 | if (!inner_map_meta) { | |
39 | fdput(f); | |
40 | return ERR_PTR(-ENOMEM); | |
41 | } | |
42 | ||
43 | inner_map_meta->map_type = inner_map->map_type; | |
44 | inner_map_meta->key_size = inner_map->key_size; | |
45 | inner_map_meta->value_size = inner_map->value_size; | |
46 | inner_map_meta->map_flags = inner_map->map_flags; | |
47 | inner_map_meta->ops = inner_map->ops; | |
48 | inner_map_meta->max_entries = inner_map->max_entries; | |
49 | ||
50 | fdput(f); | |
51 | return inner_map_meta; | |
52 | } | |
53 | ||
54 | void bpf_map_meta_free(struct bpf_map *map_meta) | |
55 | { | |
56 | kfree(map_meta); | |
57 | } | |
58 | ||
59 | bool bpf_map_meta_equal(const struct bpf_map *meta0, | |
60 | const struct bpf_map *meta1) | |
61 | { | |
62 | /* No need to compare ops because it is covered by map_type */ | |
63 | return meta0->map_type == meta1->map_type && | |
64 | meta0->key_size == meta1->key_size && | |
65 | meta0->value_size == meta1->value_size && | |
66 | meta0->map_flags == meta1->map_flags && | |
67 | meta0->max_entries == meta1->max_entries; | |
68 | } | |
69 | ||
70 | void *bpf_map_fd_get_ptr(struct bpf_map *map, | |
71 | struct file *map_file /* not used */, | |
72 | int ufd) | |
73 | { | |
74 | struct bpf_map *inner_map; | |
75 | struct fd f; | |
76 | ||
77 | f = fdget(ufd); | |
78 | inner_map = __bpf_map_get(f); | |
79 | if (IS_ERR(inner_map)) | |
80 | return inner_map; | |
81 | ||
82 | if (bpf_map_meta_equal(map->inner_map_meta, inner_map)) | |
83 | inner_map = bpf_map_inc(inner_map, false); | |
84 | else | |
85 | inner_map = ERR_PTR(-EINVAL); | |
86 | ||
87 | fdput(f); | |
88 | return inner_map; | |
89 | } | |
90 | ||
91 | void bpf_map_fd_put_ptr(void *ptr) | |
92 | { | |
93 | /* ptr->ops->map_free() has to go through one | |
94 | * rcu grace period by itself. | |
95 | */ | |
96 | bpf_map_put(ptr); | |
97 | } | |
14dc6f04 MKL |
98 | |
99 | u32 bpf_map_fd_sys_lookup_elem(void *ptr) | |
100 | { | |
101 | return ((struct bpf_map *)ptr)->id; | |
102 | } |