compression.c
2.48 KB
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
125
126
127
128
129
130
131
132
133
134
135
/*
* BTRFS filesystem implementation for U-Boot
*
* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include "btrfs.h"
#include <linux/lzo.h>
#include <u-boot/zlib.h>
#include <asm/unaligned.h>
static u32 decompress_lzo(const u8 *cbuf, u32 clen, u8 *dbuf, u32 dlen)
{
u32 tot_len, in_len, res;
size_t out_len;
int ret;
if (clen < 4)
return -1;
tot_len = le32_to_cpu(get_unaligned((u32 *)cbuf));
cbuf += 4;
clen -= 4;
tot_len -= 4;
if (tot_len == 0 && dlen)
return -1;
if (tot_len < 4)
return -1;
res = 0;
while (tot_len > 4) {
in_len = le32_to_cpu(get_unaligned((u32 *)cbuf));
cbuf += 4;
clen -= 4;
if (in_len > clen || tot_len < 4 + in_len)
return -1;
tot_len -= 4 + in_len;
out_len = dlen;
ret = lzo1x_decompress_safe(cbuf, in_len, dbuf, &out_len);
if (ret != LZO_E_OK)
return -1;
cbuf += in_len;
clen -= in_len;
dbuf += out_len;
dlen -= out_len;
res += out_len;
}
return res;
}
/* from zutil.h */
#define PRESET_DICT 0x20
static u32 decompress_zlib(const u8 *_cbuf, u32 clen, u8 *dbuf, u32 dlen)
{
int wbits = MAX_WBITS, ret = -1;
z_stream stream;
u8 *cbuf;
u32 res;
memset(&stream, 0, sizeof(stream));
cbuf = (u8 *) _cbuf;
stream.total_in = 0;
stream.next_out = dbuf;
stream.avail_out = dlen;
stream.total_out = 0;
/* skip adler32 check if deflate and no dictionary */
if (clen > 2 && !(cbuf[1] & PRESET_DICT) &&
((cbuf[0] & 0x0f) == Z_DEFLATED) &&
!(((cbuf[0] << 8) + cbuf[1]) % 31)) {
wbits = -((cbuf[0] >> 4) + 8);
cbuf += 2;
clen -= 2;
}
if (Z_OK != inflateInit2(&stream, wbits))
return -1;
while (stream.total_in < clen) {
stream.next_in = cbuf + stream.total_in;
stream.avail_in = min((u32) (clen - stream.total_in),
(u32) btrfs_info.sb.sectorsize);
ret = inflate(&stream, Z_NO_FLUSH);
if (ret != Z_OK)
break;
}
res = stream.total_out;
inflateEnd(&stream);
if (ret != Z_STREAM_END)
return -1;
return res;
}
u32 btrfs_decompress(u8 type, const char *c, u32 clen, char *d, u32 dlen)
{
u32 res;
const u8 *cbuf;
u8 *dbuf;
cbuf = (const u8 *) c;
dbuf = (u8 *) d;
switch (type) {
case BTRFS_COMPRESS_NONE:
res = dlen < clen ? dlen : clen;
memcpy(dbuf, cbuf, res);
return res;
case BTRFS_COMPRESS_ZLIB:
return decompress_zlib(cbuf, clen, dbuf, dlen);
case BTRFS_COMPRESS_LZO:
return decompress_lzo(cbuf, clen, dbuf, dlen);
default:
printf("%s: Unsupported compression in extent: %i\n", __func__,
type);
return -1;
}
}