aboutsummaryrefslogtreecommitdiff
path: root/vmdk2raw.c
blob: b2454c2d5c1e516b3e0aaa0a31eac8a8cbb33b95 (plain)
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
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
/*
   vmdk2raw: convert vmware images to raw disk images
   Copyright (C) Net Integration Technologies 2004
   Copyright (C) Matthew Chapman 2003

   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
   (at your option) 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <inttypes.h>
#include <sys/types.h>
#include <string.h>
#include <sys/stat.h>
#include <errno.h>
#include "vmdk.h"
#include "config-host.h"

static struct cowdisk_header header;
static struct vmdisk_header header4;
static off64_t disk_limit;
static unsigned int granule_size;
static uint32_t *l1dir;

static unsigned int cached_l2dir;
static uint32_t l2dir[L2_SIZE];

static struct vmdk_prm {
    uint32_t grain_table_size;
    uint32_t sectors_per_grain;
    uint32_t sectors_per_table;
    uint32_t directory_size;
} vdsk;

static size_t read_physical(int fd, off64_t offset, size_t length, void *buffer)
{
    size_t n;

    if (lseek64(fd, offset, SEEK_SET) == -1) {
        printf(" error trying to seek lseek to %lld", offset);
        return -1;
    }

    n = read(fd, buffer, length);
    
    if (n == -1) {
        printf("read from disk %lld", offset);
        return -1;
    }

    return n;
}

static int read_l1dir(int fd, size_t offset, int num)
{
    l1dir = malloc(sizeof(*l1dir) * num);
    if (!l1dir)
        return -1;
    return read_physical(fd, offset << SECTOR_BITS, sizeof(*l1dir) * num, (char *)l1dir) != (sizeof(*l1dir) * num);
}

static int read_l2dir(int fd, size_t offset, int num)
{
    return read_physical(fd, offset << SECTOR_BITS, sizeof(l2dir[0]) * num, (char *)l2dir) != sizeof(l2dir);
}

static size_t copy_virtual(struct vmdk_prm *dsk, int in_fd, int out_fd, off64_t offset, void *buffer, size_t length)
{
    
    unsigned int granule_offset;
    unsigned int grain_index;
    unsigned int sector_map_idx;
    
    granule_offset = offset % granule_size;
    length = MIN(length, granule_size - granule_offset);
    length = MIN(length, disk_limit - offset);

    sector_map_idx = (offset >> SECTOR_BITS) / dsk->sectors_per_table;
    
    if (sector_map_idx >= dsk->directory_size) {
        fprintf(stderr, "cannot locate grain table for %d in %d\n", sector_map_idx, dsk->directory_size);
        return -1;
    }

    if (l1dir[sector_map_idx] == 0)
        goto zero_fill;
   
    if (sector_map_idx != cached_l2dir) {
        if (read_l2dir(in_fd, l1dir[sector_map_idx], dsk->grain_table_size)) {
            fprintf(stderr, "read failed\n");
            return -1;
        }
        cached_l2dir = sector_map_idx;
    }

    grain_index = ((offset >> SECTOR_BITS) % dsk->sectors_per_table) / dsk->sectors_per_grain;
    
    if (grain_index >= dsk->grain_table_size) {
        fprintf(stderr, "grain to large");
        return -1;
    }

    if (l2dir[grain_index] == 0)
        goto zero_fill;

    if (read_physical(in_fd, (l2dir[grain_index] << SECTOR_BITS) + granule_offset, length, buffer) != length) {
        fprintf(stderr, "read error 2\n");
        return -1;
    }
    
    write(out_fd, buffer, length);
    return length;

zero_fill:
    /* the last chunk of the file can not be sparse
     * or the file will be truncated */
    if (offset + length >= disk_limit) {
        if (lseek64(out_fd, length-1, SEEK_CUR) == (off_t)-1)
            perror("lseek");
        /* write the last NULL byte instead of seeking */
        const char nil = 0;
        write(out_fd, &nil, 1);
    } else {
        if (lseek64(out_fd, length, SEEK_CUR) == (off_t)-1)
            perror("lseek");
    }
    return length;
}

static int open_vmdk4(int fd)
{
    if (read(fd, &header4, sizeof(header4)) != sizeof(header4)) {
        perror("read from disk");
        return -1;
    }
    
    granule_size = header4.granularity << SECTOR_BITS;
    disk_limit = header4.capacity << SECTOR_BITS; 
    
    cached_l2dir = -1;
    vdsk.grain_table_size = header4.num_gtes_per_gte;
    vdsk.sectors_per_grain = header4.granularity;
    vdsk.sectors_per_table = vdsk.grain_table_size * vdsk.sectors_per_grain;
    vdsk.directory_size = (header4.capacity + vdsk.sectors_per_table - 1) / vdsk.sectors_per_table + 1;

    if (read_l1dir(fd, header4.rgd_offset, vdsk.directory_size))
        return -1;
    
    return 0;
    
}

static int open_vmdk3(int fd)
{
    if (read(fd, &header, sizeof(header)) != sizeof(header)) {
        perror("read from disk\n");
        return -1;
    }
    granule_size = header.granularity << SECTOR_BITS;
    vdsk.sectors_per_grain = header.granularity;
    vdsk.grain_table_size = L2_SIZE;
    vdsk.sectors_per_table = vdsk.grain_table_size * vdsk.sectors_per_grain;
    vdsk.directory_size = L1_SIZE;
    if (read_l1dir(fd, header.l1dir_offset, L1_SIZE))
        return -1;

    disk_limit = header.disk_sectors << SECTOR_BITS;

    return fd;
}

static int open_vmdk(const char *filename)
{
    int fd = open(filename, O_RDONLY | O_LARGEFILE);
    if (fd == -1) {
        perror(filename);
        return -1;
    }

    char magic[4];
    if (read(fd, &magic, sizeof(magic)) != sizeof(magic)) {
        perror("read from disk");
        return -1;
    }
    
    if (!memcmp(magic, "KDMV", sizeof(magic))) {
        open_vmdk4(fd);
    } else if (!memcmp(magic, "COWD", sizeof(magic))) {
        open_vmdk3(fd);
    } else {
        fprintf(stderr, "%s is not a VMware virtual disk image\n", filename);
        return -1;
    }
    
    cached_l2dir = -1;
    return fd;
}

static void help(void)
{
    printf("vmdk2raw\n"
           "usage: vmdk2raw vmware_image output_image\n"
           "\n"
           "vmware_image   a vmware cow image\n"
           "output_image   the created disk image\n" 
          );
    exit(1);
}

#define BUF_SIZE 0x10000
static void copy_disk(in_fd, out_fd)
{
    char buf[BUF_SIZE];
    off64_t i = 0;
    int ret;
    while (i < disk_limit) {
        ret = copy_virtual(&vdsk, in_fd, out_fd, i, buf, sizeof(buf));
        if (ret < 0) {
            fprintf(stderr, "copying failed\n");
            exit(-1);
        }
        i += ret;
    }
}

int main(int argc, char **argv)
{
    int out_fd, in_fd;

    if (argc < 3)
        help();

    in_fd = open_vmdk(argv[1]);
    if (in_fd < 0) {
        return -1;
    }

    out_fd = open(argv[2], O_WRONLY | O_LARGEFILE | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
    if (out_fd < 0) {
        perror(argv[2]);
        return -1;
    }

    copy_disk(in_fd, out_fd);
    close(out_fd);
    return 0;
}