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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
/*
* Copyright (C) 2021 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <ipxe/deflate.h>
#include <ipxe/image.h>
#include <ipxe/zlib.h>
#include <ipxe/gzip.h>
/** @file
*
* gzip compressed images
*
*/
/**
* Extract gzip image
*
* @v image Image
* @v extracted Extracted image
* @ret rc Return status code
*/
static int gzip_extract ( struct image *image, struct image *extracted ) {
const struct gzip_header *header;
const struct gzip_extra_header *extra;
const struct gzip_crc_header *crc;
const struct gzip_footer *footer;
const void *data;
size_t extra_len;
size_t string_len;
size_t len;
unsigned int strings;
int rc;
/* Sanity check */
assert ( image->len >= ( sizeof ( *header ) + sizeof ( *footer ) ) );
data = image->data;
len = image->len;
/* Extract footer */
assert ( len >= sizeof ( *footer ) );
len -= sizeof ( *footer );
footer = ( data + len );
/* Extract fixed header */
assert ( len >= sizeof ( *header ) );
header = data;
data += sizeof ( *header );
len -= sizeof ( *header );
/* Skip extra header, if present */
if ( header->flags & GZIP_FL_EXTRA ) {
if ( len < sizeof ( *extra ) ) {
DBGC ( image, "GZIP %s overlength extra header\n",
image->name );
return -EINVAL;
}
extra = data;
data += sizeof ( *extra );
len -= sizeof ( *extra );
extra_len = le16_to_cpu ( extra->len );
if ( len < extra_len ) {
DBGC ( image, "GZIP %s overlength extra header\n",
image->name );
return -EINVAL;
}
data += extra_len;
len -= extra_len;
}
/* Skip name and/or comment, if present */
strings = 0;
if ( header->flags & GZIP_FL_NAME )
strings++;
if ( header->flags & GZIP_FL_COMMENT )
strings++;
while ( strings-- ) {
string_len = strnlen ( data, len );
if ( string_len == len ) {
DBGC ( image, "GZIP %s overlength name/comment\n",
image->name );
return -EINVAL;
}
data += ( string_len + 1 /* NUL */ );
len -= ( string_len + 1 /* NUL */ );
}
/* Skip CRC, if present */
if ( header->flags & GZIP_FL_HCRC ) {
if ( len < sizeof ( *crc ) ) {
DBGC ( image, "GZIP %s overlength CRC header\n",
image->name );
return -EINVAL;
}
data += sizeof ( *crc );
len -= sizeof ( *crc );
}
/* Presize extracted image */
if ( ( rc = image_set_len ( extracted,
le32_to_cpu ( footer->len ) ) ) != 0 ) {
DBGC ( image, "GZIP %s could not presize: %s\n",
image->name, strerror ( rc ) );
return rc;
}
/* Decompress image (expanding if necessary) */
if ( ( rc = zlib_deflate ( DEFLATE_RAW, data, len,
extracted ) ) != 0 ) {
DBGC ( image, "GZIP %s could not decompress: %s\n",
image->name, strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Probe gzip image
*
* @v image gzip image
* @ret rc Return status code
*/
static int gzip_probe ( struct image *image ) {
const struct gzip_header *header;
const struct gzip_footer *footer;
/* Sanity check */
if ( image->len < ( sizeof ( *header ) + sizeof ( *footer ) ) ) {
DBGC ( image, "GZIP %s image too short\n", image->name );
return -ENOEXEC;
}
header = image->data;
/* Check magic header */
if ( header->magic != cpu_to_be16 ( GZIP_MAGIC ) ) {
DBGC ( image, "GZIP %s invalid magic\n", image->name );
return -ENOEXEC;
}
return 0;
}
/** gzip image type */
struct image_type gzip_image_type __image_type ( PROBE_NORMAL ) = {
.name = "gzip",
.probe = gzip_probe,
.extract = gzip_extract,
.exec = image_extract_exec,
};
|
