1 /*
2 * Copyright (c) 2009, 2010, 2013
3 * Phillip Lougher <phillip@squashfs.org.uk>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2,
8 * or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 *
19 * lzma_wrapper.c
20 *
21 * Support for LZMA1 compression using LZMA SDK (4.65 used in
22 * development, other versions may work) http://www.7-zip.org/sdk.html
23 */
24
25 #include <LzmaLib.h>
26
27 #include "squashfs_fs.h"
28 #include "compressor.h"
29
30 #define LZMA_HEADER_SIZE (LZMA_PROPS_SIZE + 8)
31
lzma_compress(void * strm,void * dest,void * src,int size,int block_size,int * error)32 static int lzma_compress(void *strm, void *dest, void *src, int size, int block_size,
33 int *error)
34 {
35 unsigned char *d = dest;
36 size_t props_size = LZMA_PROPS_SIZE,
37 outlen = block_size - LZMA_HEADER_SIZE;
38 int res;
39
40 res = LzmaCompress(dest + LZMA_HEADER_SIZE, &outlen, src, size, dest,
41 &props_size, 5, block_size, 3, 0, 2, 32, 1);
42
43 if(res == SZ_ERROR_OUTPUT_EOF) {
44 /*
45 * Output buffer overflow. Return out of buffer space error
46 */
47 return 0;
48 }
49
50 if(res != SZ_OK) {
51 /*
52 * All other errors return failure, with the compressor
53 * specific error code in *error
54 */
55 *error = res;
56 return -1;
57 }
58
59 /*
60 * Fill in the 8 byte little endian uncompressed size field in the
61 * LZMA header. 8 bytes is excessively large for squashfs but
62 * this is the standard LZMA header and which is expected by the kernel
63 * code
64 */
65 d[LZMA_PROPS_SIZE] = size & 255;
66 d[LZMA_PROPS_SIZE + 1] = (size >> 8) & 255;
67 d[LZMA_PROPS_SIZE + 2] = (size >> 16) & 255;
68 d[LZMA_PROPS_SIZE + 3] = (size >> 24) & 255;
69 d[LZMA_PROPS_SIZE + 4] = 0;
70 d[LZMA_PROPS_SIZE + 5] = 0;
71 d[LZMA_PROPS_SIZE + 6] = 0;
72 d[LZMA_PROPS_SIZE + 7] = 0;
73
74 /*
75 * Success, return the compressed size. Outlen returned by the LZMA
76 * compressor does not include the LZMA header space
77 */
78 return outlen + LZMA_HEADER_SIZE;
79 }
80
81
lzma_uncompress(void * dest,void * src,int size,int outsize,int * error)82 static int lzma_uncompress(void *dest, void *src, int size, int outsize,
83 int *error)
84 {
85 unsigned char *s = src;
86 size_t outlen, inlen = size - LZMA_HEADER_SIZE;
87 int res;
88
89 outlen = s[LZMA_PROPS_SIZE] |
90 (s[LZMA_PROPS_SIZE + 1] << 8) |
91 (s[LZMA_PROPS_SIZE + 2] << 16) |
92 (s[LZMA_PROPS_SIZE + 3] << 24);
93
94 if(outlen > outsize) {
95 *error = 0;
96 return -1;
97 }
98
99 res = LzmaUncompress(dest, &outlen, src + LZMA_HEADER_SIZE, &inlen, src,
100 LZMA_PROPS_SIZE);
101
102 if(res == SZ_OK)
103 return outlen;
104 else {
105 *error = res;
106 return -1;
107 }
108 }
109
110
111 struct compressor lzma_comp_ops = {
112 .init = NULL,
113 .compress = lzma_compress,
114 .uncompress = lzma_uncompress,
115 .options = NULL,
116 .usage = NULL,
117 .id = LZMA_COMPRESSION,
118 .name = "lzma",
119 .supported = 1
120 };
121
122