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// SPDX-License-Identifier: GPL-2.0+
/*
* BTRFS filesystem implementation for U-Boot
*
* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
*/
#include "btrfs.h"
#include "disk-io.h"
static int verify_dir_item(struct btrfs_root *root,
struct extent_buffer *leaf,
struct btrfs_dir_item *dir_item)
{
u16 namelen = BTRFS_NAME_LEN;
u8 type = btrfs_dir_type(leaf, dir_item);
if (type == BTRFS_FT_XATTR)
namelen = XATTR_NAME_MAX;
if (btrfs_dir_name_len(leaf, dir_item) > namelen) {
fprintf(stderr, "invalid dir item name len: %u\n",
(unsigned)btrfs_dir_data_len(leaf, dir_item));
return 1;
}
/* BTRFS_MAX_XATTR_SIZE is the same for all dir items */
if ((btrfs_dir_data_len(leaf, dir_item) +
btrfs_dir_name_len(leaf, dir_item)) >
BTRFS_MAX_XATTR_SIZE(root->fs_info)) {
fprintf(stderr, "invalid dir item name + data len: %u + %u\n",
(unsigned)btrfs_dir_name_len(leaf, dir_item),
(unsigned)btrfs_dir_data_len(leaf, dir_item));
return 1;
}
return 0;
}
struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
struct btrfs_path *path,
const char *name, int name_len)
{
struct btrfs_dir_item *dir_item;
unsigned long name_ptr;
u32 total_len;
u32 cur = 0;
u32 this_len;
struct extent_buffer *leaf;
leaf = path->nodes[0];
dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
total_len = btrfs_item_size_nr(leaf, path->slots[0]);
if (verify_dir_item(root, leaf, dir_item))
return NULL;
while(cur < total_len) {
this_len = sizeof(*dir_item) +
btrfs_dir_name_len(leaf, dir_item) +
btrfs_dir_data_len(leaf, dir_item);
if (this_len > (total_len - cur)) {
fprintf(stderr, "invalid dir item size\n");
return NULL;
}
name_ptr = (unsigned long)(dir_item + 1);
if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
return dir_item;
cur += this_len;
dir_item = (struct btrfs_dir_item *)((char *)dir_item +
this_len);
}
return NULL;
}
struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 dir,
const char *name, int name_len,
int mod)
{
int ret;
struct btrfs_key key;
int ins_len = mod < 0 ? -1 : 0;
int cow = mod != 0;
struct btrfs_key found_key;
struct extent_buffer *leaf;
key.objectid = dir;
key.type = BTRFS_DIR_ITEM_KEY;
key.offset = btrfs_name_hash(name, name_len);
ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
if (ret < 0)
return ERR_PTR(ret);
if (ret > 0) {
if (path->slots[0] == 0)
return NULL;
path->slots[0]--;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != dir ||
found_key.type != BTRFS_DIR_ITEM_KEY ||
found_key.offset != key.offset)
return NULL;
return btrfs_match_dir_item_name(root, path, name, name_len);
}
static int __verify_dir_item(struct btrfs_dir_item *item, u32 start, u32 total)
{
u16 max_len = BTRFS_NAME_LEN;
u32 end;
if (item->type >= BTRFS_FT_MAX) {
printf("%s: invalid dir item type: %i\n", __func__, item->type);
return 1;
}
if (item->type == BTRFS_FT_XATTR)
max_len = 255; /* XATTR_NAME_MAX */
end = start + sizeof(*item) + item->name_len;
if (item->name_len > max_len || end > total) {
printf("%s: invalid dir item name len: %u\n", __func__,
item->name_len);
return 1;
}
return 0;
}
static struct btrfs_dir_item *
__btrfs_match_dir_item_name(struct __btrfs_path *path, const char *name,
int name_len)
{
struct btrfs_dir_item *item;
u32 total_len, cur = 0, this_len;
const char *name_ptr;
item = btrfs_path_item_ptr(path, struct btrfs_dir_item);
total_len = btrfs_path_item_size(path);
while (cur < total_len) {
btrfs_dir_item_to_cpu(item);
this_len = sizeof(*item) + item->name_len + item->data_len;
name_ptr = (const char *) (item + 1);
if (__verify_dir_item(item, cur, total_len))
return NULL;
if (item->name_len == name_len && !memcmp(name_ptr, name,
name_len))
return item;
cur += this_len;
item = (struct btrfs_dir_item *) ((u8 *) item + this_len);
}
return NULL;
}
int __btrfs_lookup_dir_item(const struct __btrfs_root *root, u64 dir,
const char *name, int name_len,
struct btrfs_dir_item *item)
{
struct __btrfs_path path;
struct btrfs_key key;
struct btrfs_dir_item *res = NULL;
key.objectid = dir;
key.type = BTRFS_DIR_ITEM_KEY;
key.offset = btrfs_name_hash(name, name_len);
if (btrfs_search_tree(root, &key, &path))
return -1;
if (btrfs_comp_keys_type(&key, btrfs_path_leaf_key(&path)))
goto out;
res = __btrfs_match_dir_item_name(&path, name, name_len);
if (res)
*item = *res;
out:
__btrfs_free_path(&path);
return res ? 0 : -1;
}
int btrfs_readdir(const struct __btrfs_root *root, u64 dir,
btrfs_readdir_callback_t callback)
{
struct __btrfs_path path;
struct btrfs_key key, *found_key;
struct btrfs_dir_item *item;
int res = 0;
key.objectid = dir;
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = 0;
if (btrfs_search_tree(root, &key, &path))
return -1;
do {
found_key = btrfs_path_leaf_key(&path);
if (btrfs_comp_keys_type(&key, found_key))
break;
item = btrfs_path_item_ptr(&path, struct btrfs_dir_item);
btrfs_dir_item_to_cpu(item);
if (__verify_dir_item(item, 0, sizeof(*item) + item->name_len))
continue;
if (item->type == BTRFS_FT_XATTR)
continue;
if (callback(root, item))
break;
} while (!(res = btrfs_next_slot(&path)));
__btrfs_free_path(&path);
return res < 0 ? -1 : 0;
}
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