| Martin KaFai Lau | 56f668d | 2017-03-22 10:00:33 -0700 | [diff] [blame] | 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 | } |
| Martin KaFai Lau | 14dc6f0 | 2017-06-27 23:08:34 -0700 | [diff] [blame] | 98 | |
| 99 | u32 bpf_map_fd_sys_lookup_elem(void *ptr) |
| 100 | { |
| 101 | return ((struct bpf_map *)ptr)->id; |
| 102 | } |