1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
// SPDX-License-Identifier: GPL-2.0+
/*
* BTRFS filesystem implementation for U-Boot
*
* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
*/
#include "btrfs.h"
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;
}
|
