Marek Behún | 2938754 | 2017-09-03 17:00:28 +0200 | [diff] [blame] | 1 | /* |
| 2 | * BTRFS filesystem implementation for U-Boot |
| 3 | * |
| 4 | * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz |
| 5 | * |
| 6 | * SPDX-License-Identifier: GPL-2.0+ |
| 7 | */ |
| 8 | |
| 9 | #include "btrfs.h" |
| 10 | |
| 11 | static int verify_dir_item(struct btrfs_dir_item *item, u32 start, u32 total) |
| 12 | { |
| 13 | u16 max_len = BTRFS_NAME_LEN; |
| 14 | u32 end; |
| 15 | |
| 16 | if (item->type >= BTRFS_FT_MAX) { |
| 17 | printf("%s: invalid dir item type: %i\n", __func__, item->type); |
| 18 | return 1; |
| 19 | } |
| 20 | |
| 21 | if (item->type == BTRFS_FT_XATTR) |
| 22 | max_len = 255; /* XATTR_NAME_MAX */ |
| 23 | |
| 24 | end = start + sizeof(*item) + item->name_len; |
| 25 | if (item->name_len > max_len || end > total) { |
| 26 | printf("%s: invalid dir item name len: %u\n", __func__, |
| 27 | item->name_len); |
| 28 | return 1; |
| 29 | } |
| 30 | |
| 31 | return 0; |
| 32 | } |
| 33 | |
| 34 | static struct btrfs_dir_item * |
| 35 | btrfs_match_dir_item_name(struct btrfs_path *path, const char *name, |
| 36 | int name_len) |
| 37 | { |
| 38 | struct btrfs_dir_item *item; |
| 39 | u32 total_len, cur = 0, this_len; |
| 40 | const char *name_ptr; |
| 41 | |
| 42 | item = btrfs_path_item_ptr(path, struct btrfs_dir_item); |
| 43 | |
| 44 | total_len = btrfs_path_item_size(path); |
| 45 | |
| 46 | while (cur < total_len) { |
| 47 | btrfs_dir_item_to_cpu(item); |
| 48 | this_len = sizeof(*item) + item->name_len + item->data_len; |
| 49 | name_ptr = (const char *) (item + 1); |
| 50 | |
| 51 | if (verify_dir_item(item, cur, total_len)) |
| 52 | return NULL; |
| 53 | if (item->name_len == name_len && !memcmp(name_ptr, name, |
| 54 | name_len)) |
| 55 | return item; |
| 56 | |
| 57 | cur += this_len; |
| 58 | item = (struct btrfs_dir_item *) ((u8 *) item + this_len); |
| 59 | } |
| 60 | |
| 61 | return NULL; |
| 62 | } |
| 63 | |
| 64 | int btrfs_lookup_dir_item(const struct btrfs_root *root, u64 dir, |
| 65 | const char *name, int name_len, |
| 66 | struct btrfs_dir_item *item) |
| 67 | { |
| 68 | struct btrfs_path path; |
| 69 | struct btrfs_key key; |
| 70 | struct btrfs_dir_item *res = NULL; |
| 71 | |
| 72 | key.objectid = dir; |
| 73 | key.type = BTRFS_DIR_ITEM_KEY; |
| 74 | key.offset = btrfs_name_hash(name, name_len); |
| 75 | |
| 76 | if (btrfs_search_tree(root, &key, &path)) |
| 77 | return -1; |
| 78 | |
| 79 | if (btrfs_comp_keys_type(&key, btrfs_path_leaf_key(&path))) |
| 80 | goto out; |
| 81 | |
| 82 | res = btrfs_match_dir_item_name(&path, name, name_len); |
| 83 | if (res) |
| 84 | *item = *res; |
| 85 | out: |
| 86 | btrfs_free_path(&path); |
| 87 | return res ? 0 : -1; |
| 88 | } |
| 89 | |
| 90 | int btrfs_readdir(const struct btrfs_root *root, u64 dir, |
| 91 | btrfs_readdir_callback_t callback) |
| 92 | { |
| 93 | struct btrfs_path path; |
| 94 | struct btrfs_key key, *found_key; |
| 95 | struct btrfs_dir_item *item; |
Marek Behún | da98910 | 2017-10-06 15:04:57 +0200 | [diff] [blame] | 96 | int res = 0; |
Marek Behún | 2938754 | 2017-09-03 17:00:28 +0200 | [diff] [blame] | 97 | |
| 98 | key.objectid = dir; |
| 99 | key.type = BTRFS_DIR_INDEX_KEY; |
| 100 | key.offset = 0; |
| 101 | |
| 102 | if (btrfs_search_tree(root, &key, &path)) |
| 103 | return -1; |
| 104 | |
| 105 | do { |
| 106 | found_key = btrfs_path_leaf_key(&path); |
| 107 | if (btrfs_comp_keys_type(&key, found_key)) |
| 108 | break; |
| 109 | |
| 110 | item = btrfs_path_item_ptr(&path, struct btrfs_dir_item); |
| 111 | btrfs_dir_item_to_cpu(item); |
| 112 | |
| 113 | if (verify_dir_item(item, 0, sizeof(*item) + item->name_len)) |
| 114 | continue; |
| 115 | if (item->type == BTRFS_FT_XATTR) |
| 116 | continue; |
| 117 | |
| 118 | if (callback(root, item)) |
| 119 | break; |
| 120 | } while (!(res = btrfs_next_slot(&path))); |
| 121 | |
| 122 | btrfs_free_path(&path); |
| 123 | |
| 124 | return res < 0 ? -1 : 0; |
| 125 | } |