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