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
|
package btrfsitem
import (
"fmt"
"hash/crc32"
"lukeshu.com/btrfs-tools/pkg/binstruct"
"lukeshu.com/btrfs-tools/pkg/btrfs/internal"
)
// key.objectid = inode of directory containing this entry
// key.offset =
// for DIR_ITEM and XATTR_ITEM = NameHash(name)
// for DIR_INDEX = index id in the directory (starting at 2, because "." and "..")
type DirEntries []DirEntry // DIR_ITEM=84 DIR_INDEX=96 XATTR_ITEM=24
func NameHash(dat []byte) uint64 {
return uint64(^crc32.Update(1, crc32.MakeTable(crc32.Castagnoli), dat))
}
func (o *DirEntries) UnmarshalBinary(dat []byte) (int, error) {
*o = nil
n := 0
for n < len(dat) {
var ref DirEntry
_n, err := binstruct.Unmarshal(dat, &ref)
n += _n
if err != nil {
return n, err
}
*o = append(*o, ref)
}
return n, nil
}
func (o DirEntries) MarshalBinary() ([]byte, error) {
var ret []byte
for _, ref := range o {
bs, err := binstruct.Marshal(ref)
ret = append(ret, bs...)
if err != nil {
return ret, err
}
}
return ret, nil
}
type DirEntry struct {
Location internal.Key `bin:"off=0x0, siz=0x11"`
TransID int64 `bin:"off=0x11, siz=8"`
DataLen uint16 `bin:"off=0x19, siz=2"` // [ignored-when-writing]
NameLen uint16 `bin:"off=0x1b, siz=2"` // [ignored-when-writing]
Type FileType `bin:"off=0x1d, siz=1"`
binstruct.End `bin:"off=0x1e"`
Data []byte `bin:"-"`
Name []byte `bin:"-"`
}
func (o *DirEntry) UnmarshalBinary(dat []byte) (int, error) {
n, err := binstruct.UnmarshalWithoutInterface(dat, o)
if err != nil {
return n, err
}
o.Data = dat[n : n+int(o.DataLen)]
n += int(o.DataLen)
o.Name = dat[n : n+int(o.NameLen)]
n += int(o.NameLen)
return n, nil
}
func (o DirEntry) MarshalBinary() ([]byte, error) {
o.DataLen = uint16(len(o.Data))
o.NameLen = uint16(len(o.Name))
dat, err := binstruct.MarshalWithoutInterface(o)
if err != nil {
return dat, err
}
dat = append(dat, o.Data...)
dat = append(dat, o.Name...)
return dat, nil
}
type FileType uint8
const (
FT_UNKNOWN = FileType(0)
FT_REG_FILE = FileType(1)
FT_DIR = FileType(2)
FT_CHRDEV = FileType(3)
FT_BLKDEV = FileType(4)
FT_FIFO = FileType(5)
FT_SOCK = FileType(6)
FT_SYMLINK = FileType(7)
FT_XATTR = FileType(8)
FT_MAX = FileType(9)
)
func (ft FileType) String() string {
names := map[FileType]string{
FT_UNKNOWN: "UNKNOWN",
FT_REG_FILE: "FILE", // XXX
FT_DIR: "DIR",
FT_CHRDEV: "CHRDEV",
FT_BLKDEV: "BLKDEV",
FT_FIFO: "FIFO",
FT_SOCK: "SOCK",
FT_SYMLINK: "SYMLINK",
FT_XATTR: "XATTR",
}
if name, ok := names[ft]; ok {
return name
}
return fmt.Sprintf("DIR_ITEM.%d", uint8(ft))
}
|
