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1/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
5 * Phillip Lougher <phillip@squashfs.org.uk>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2,
10 * or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 *
21 * decompressor.c
22 */
23
24#include <linux/types.h>
25#include <linux/mutex.h>
26#include <linux/slab.h>
27#include <linux/buffer_head.h>
28
29#include "squashfs_fs.h"
30#include "squashfs_fs_sb.h"
31#include "decompressor.h"
32#include "squashfs.h"
33
34/*
35 * This file (and decompressor.h) implements a decompressor framework for
36 * Squashfs, allowing multiple decompressors to be easily supported
37 */
38
39static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
40 NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
41};
42
43#ifndef CONFIG_SQUASHFS_LZO
44static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
45 NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
46};
47#endif
48
49#ifndef CONFIG_SQUASHFS_XZ
50static const struct squashfs_decompressor squashfs_xz_comp_ops = {
51 NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0
52};
53#endif
54
55#ifndef CONFIG_SQUASHFS_ZLIB
56static const struct squashfs_decompressor squashfs_zlib_comp_ops = {
57 NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0
58};
59#endif
60
61static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
62 NULL, NULL, NULL, 0, "unknown", 0
63};
64
65static const struct squashfs_decompressor *decompressor[] = {
66 &squashfs_zlib_comp_ops,
67 &squashfs_lzo_comp_ops,
68 &squashfs_xz_comp_ops,
69 &squashfs_lzma_unsupported_comp_ops,
70 &squashfs_unknown_comp_ops
71};
72
73
74const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
75{
76 int i;
77
78 for (i = 0; decompressor[i]->id; i++)
79 if (id == decompressor[i]->id)
80 break;
81
82 return decompressor[i];
83}
84
85
86void *squashfs_decompressor_init(struct super_block *sb, unsigned short flags)
87{
88 struct squashfs_sb_info *msblk = sb->s_fs_info;
89 void *strm, *buffer = NULL;
90 int length = 0;
91
92 /*
93 * Read decompressor specific options from file system if present
94 */
95 if (SQUASHFS_COMP_OPTS(flags)) {
96 buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
97 if (buffer == NULL)
98 return ERR_PTR(-ENOMEM);
99
100 length = squashfs_read_data(sb, &buffer,
101 sizeof(struct squashfs_super_block), 0, NULL,
102 PAGE_CACHE_SIZE, 1);
103
104 if (length < 0) {
105 strm = ERR_PTR(length);
106 goto finished;
107 }
108 }
109
110 strm = msblk->decompressor->init(msblk, buffer, length);
111
112finished:
113 kfree(buffer);
114
115 return strm;
116}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Squashfs - a compressed read only filesystem for Linux
4 *
5 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
6 * Phillip Lougher <phillip@squashfs.org.uk>
7 *
8 * decompressor.c
9 */
10
11#include <linux/types.h>
12#include <linux/mutex.h>
13#include <linux/slab.h>
14
15#include "squashfs_fs.h"
16#include "squashfs_fs_sb.h"
17#include "decompressor.h"
18#include "squashfs.h"
19#include "page_actor.h"
20
21/*
22 * This file (and decompressor.h) implements a decompressor framework for
23 * Squashfs, allowing multiple decompressors to be easily supported
24 */
25
26static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
27 NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
28};
29
30#ifndef CONFIG_SQUASHFS_LZ4
31static const struct squashfs_decompressor squashfs_lz4_comp_ops = {
32 NULL, NULL, NULL, NULL, LZ4_COMPRESSION, "lz4", 0
33};
34#endif
35
36#ifndef CONFIG_SQUASHFS_LZO
37static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
38 NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
39};
40#endif
41
42#ifndef CONFIG_SQUASHFS_XZ
43static const struct squashfs_decompressor squashfs_xz_comp_ops = {
44 NULL, NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0
45};
46#endif
47
48#ifndef CONFIG_SQUASHFS_ZLIB
49static const struct squashfs_decompressor squashfs_zlib_comp_ops = {
50 NULL, NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0
51};
52#endif
53
54#ifndef CONFIG_SQUASHFS_ZSTD
55static const struct squashfs_decompressor squashfs_zstd_comp_ops = {
56 NULL, NULL, NULL, NULL, ZSTD_COMPRESSION, "zstd", 0
57};
58#endif
59
60static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
61 NULL, NULL, NULL, NULL, 0, "unknown", 0
62};
63
64static const struct squashfs_decompressor *decompressor[] = {
65 &squashfs_zlib_comp_ops,
66 &squashfs_lz4_comp_ops,
67 &squashfs_lzo_comp_ops,
68 &squashfs_xz_comp_ops,
69 &squashfs_lzma_unsupported_comp_ops,
70 &squashfs_zstd_comp_ops,
71 &squashfs_unknown_comp_ops
72};
73
74
75const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
76{
77 int i;
78
79 for (i = 0; decompressor[i]->id; i++)
80 if (id == decompressor[i]->id)
81 break;
82
83 return decompressor[i];
84}
85
86
87static void *get_comp_opts(struct super_block *sb, unsigned short flags)
88{
89 struct squashfs_sb_info *msblk = sb->s_fs_info;
90 void *buffer = NULL, *comp_opts;
91 struct squashfs_page_actor *actor = NULL;
92 int length = 0;
93
94 /*
95 * Read decompressor specific options from file system if present
96 */
97 if (SQUASHFS_COMP_OPTS(flags)) {
98 buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
99 if (buffer == NULL) {
100 comp_opts = ERR_PTR(-ENOMEM);
101 goto out;
102 }
103
104 actor = squashfs_page_actor_init(&buffer, 1, 0);
105 if (actor == NULL) {
106 comp_opts = ERR_PTR(-ENOMEM);
107 goto out;
108 }
109
110 length = squashfs_read_data(sb,
111 sizeof(struct squashfs_super_block), 0, NULL, actor);
112
113 if (length < 0) {
114 comp_opts = ERR_PTR(length);
115 goto out;
116 }
117 }
118
119 comp_opts = squashfs_comp_opts(msblk, buffer, length);
120
121out:
122 kfree(actor);
123 kfree(buffer);
124 return comp_opts;
125}
126
127
128void *squashfs_decompressor_setup(struct super_block *sb, unsigned short flags)
129{
130 struct squashfs_sb_info *msblk = sb->s_fs_info;
131 void *stream, *comp_opts = get_comp_opts(sb, flags);
132
133 if (IS_ERR(comp_opts))
134 return comp_opts;
135
136 stream = msblk->thread_ops->create(msblk, comp_opts);
137 if (IS_ERR(stream))
138 kfree(comp_opts);
139
140 return stream;
141}