vmdk2raw.c

   1 /*
   2    vmdk2raw: convert vmware images to raw disk images
   3    Copyright (C) Net Integration Technologies 2004
   4    Copyright (C) Matthew Chapman 2003
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include <stdlib.h>
  22 #include <stdio.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <inttypes.h>
  26 #include <sys/types.h>
  27 #include <string.h>
  28 #include <sys/stat.h>
  29 #include <errno.h>
  30 #include "vmdk.h"
  31 #include "config-host.h"
  32
  33 static struct cowdisk_header header;
  34 static struct vmdisk_header header4;
  35 static off64_t disk_limit;
  36 static unsigned int granule_size;
  37 static uint32_t *l1dir;
  38
  39 static unsigned int cached_l2dir;
  40 static uint32_t l2dir[L2_SIZE];
  41
  42 static struct vmdk_prm {
  43     uint32_t grain_table_size;
  44     uint32_t sectors_per_grain;
  45     uint32_t sectors_per_table;
  46     uint32_t directory_size;
  47 } vdsk;
  48
  49 static size_t read_physical(int fd, off64_t offset, size_t length, void *buffer)
  50 {
  51     size_t n;
  52
  53     if (lseek64(fd, offset, SEEK_SET) == -1) {
  54         printf(" error trying to seek lseek to %lld", offset);
  55         return -1;
  56     }
  57
  58     n = read(fd, buffer, length);
  59
  60     if (n == -1) {
  61         printf("read from disk %lld", offset);
  62         return -1;
  63     }
  64
  65     return n;
  66 }
  67
  68 static int read_l1dir(int fd, size_t offset, int num)
  69 {
  70     l1dir = malloc(sizeof(*l1dir) * num);
  71     if (!l1dir)
  72         return -1;
  73     return read_physical(fd, offset << SECTOR_BITS, sizeof(*l1dir) * num, (char *)l1dir) != (sizeof(*l1dir) * num);
  74 }
  75
  76 static int read_l2dir(int fd, size_t offset, int num)
  77 {
  78     return read_physical(fd, offset << SECTOR_BITS, sizeof(l2dir[0]) * num, (char *)l2dir) != sizeof(l2dir);
  79 }
  80
  81 static size_t copy_virtual(struct vmdk_prm *dsk, int in_fd, int out_fd, off64_t offset, void *buffer, size_t length)
  82 {
  83
  84     unsigned int granule_offset;
  85     unsigned int grain_index;
  86     unsigned int sector_map_idx;
  87
  88     granule_offset = offset % granule_size;
  89     length = MIN(length, granule_size - granule_offset);
  90     length = MIN(length, disk_limit - offset);
  91
  92     sector_map_idx = (offset >> SECTOR_BITS) / dsk->sectors_per_table;
  93
  94     if (sector_map_idx >= dsk->directory_size) {
  95         fprintf(stderr, "cannot locate grain table for %d in %d\n", sector_map_idx, dsk->directory_size);
  96         return -1;
  97     }
  98
  99     if (l1dir[sector_map_idx] == 0)
 100         goto zero_fill;
 101
 102     if (sector_map_idx != cached_l2dir) {
 103         if (read_l2dir(in_fd, l1dir[sector_map_idx], dsk->grain_table_size)) {
 104             fprintf(stderr, "read failed\n");
 105             return -1;
 106         }
 107         cached_l2dir = sector_map_idx;
 108     }
 109
 110     grain_index = ((offset >> SECTOR_BITS) % dsk->sectors_per_table) / dsk->sectors_per_grain;
 111
 112     if (grain_index >= dsk->grain_table_size) {
 113         fprintf(stderr, "grain to large");
 114         return -1;
 115     }
 116
 117     if (l2dir[grain_index] == 0)
 118         goto zero_fill;
 119
 120     if (read_physical(in_fd, (l2dir[grain_index] << SECTOR_BITS) + granule_offset, length, buffer) != length) {
 121         fprintf(stderr, "read error 2\n");
 122         return -1;
 123     }
 124
 125     write(out_fd, buffer, length);
 126     return length;
 127
 128 zero_fill:
 129     /* the last chunk of the file can not be sparse
 130      * or the file will be truncated */
 131     if (offset + length >= disk_limit) {
 132         if (lseek64(out_fd, length-1, SEEK_CUR) == (off_t)-1)
 133             perror("lseek");
 134         /* write the last NULL byte instead of seeking */
 135         const char nil = 0;
 136         write(out_fd, &nil, 1);
 137     } else {
 138         if (lseek64(out_fd, length, SEEK_CUR) == (off_t)-1)
 139             perror("lseek");
 140     }
 141     return length;
 142 }
 143
 144 static int open_vmdk4(int fd)
 145 {
 146     if (read(fd, &header4, sizeof(header4)) != sizeof(header4)) {
 147         perror("read from disk");
 148         return -1;
 149     }
 150
 151     granule_size = header4.granularity << SECTOR_BITS;
 152     disk_limit = header4.capacity << SECTOR_BITS;
 153
 154     cached_l2dir = -1;
 155     vdsk.grain_table_size = header4.num_gtes_per_gte;
 156     vdsk.sectors_per_grain = header4.granularity;
 157     vdsk.sectors_per_table = vdsk.grain_table_size * vdsk.sectors_per_grain;
 158     vdsk.directory_size = (header4.capacity + vdsk.sectors_per_table - 1) / vdsk.sectors_per_table + 1;
 159
 160     if (read_l1dir(fd, header4.rgd_offset, vdsk.directory_size))
 161         return -1;
 162
 163     return 0;
 164
 165 }
 166
 167 static int open_vmdk3(int fd)
 168 {
 169     if (read(fd, &header, sizeof(header)) != sizeof(header)) {
 170         perror("read from disk\n");
 171         return -1;
 172     }
 173     granule_size = header.granularity << SECTOR_BITS;
 174     vdsk.sectors_per_grain = header.granularity;
 175     vdsk.grain_table_size = L2_SIZE;
 176     vdsk.sectors_per_table = vdsk.grain_table_size * vdsk.sectors_per_grain;
 177     vdsk.directory_size = L1_SIZE;
 178     if (read_l1dir(fd, header.l1dir_offset, L1_SIZE))
 179         return -1;
 180
 181     disk_limit = header.disk_sectors << SECTOR_BITS;
 182
 183     return fd;
 184 }
 185
 186 static int open_vmdk(const char *filename)
 187 {
 188     int fd = open(filename, O_RDONLY | O_LARGEFILE);
 189     if (fd == -1) {
 190         perror(filename);
 191         return -1;
 192     }
 193
 194     char magic[4];
 195     if (read(fd, &magic, sizeof(magic)) != sizeof(magic)) {
 196         perror("read from disk");
 197         return -1;
 198     }
 199
 200     if (!memcmp(magic, "KDMV", sizeof(magic))) {
 201         open_vmdk4(fd);
 202     } else if (!memcmp(magic, "COWD", sizeof(magic))) {
 203         open_vmdk3(fd);
 204     } else {
 205         fprintf(stderr, "%s is not a VMware virtual disk image\n", filename);
 206         return -1;
 207     }
 208
 209     cached_l2dir = -1;
 210     return fd;
 211 }
 212
 213 static void help(void)
 214 {
 215     printf("vmdk2raw\n"
 216            "usage: vmdk2raw vmware_image output_image\n"
 217            "\n"
 218            "vmware_image   a vmware cow image\n"
 219            "output_image   the created disk image\n"
 220           );
 221     exit(1);
 222 }
 223
 224 #define BUF_SIZE 0x10000
 225 static void copy_disk(in_fd, out_fd)
 226 {
 227     char buf[BUF_SIZE];
 228     off64_t i = 0;
 229     int ret;
 230     while (i < disk_limit) {
 231         ret = copy_virtual(&vdsk, in_fd, out_fd, i, buf, sizeof(buf));
 232         if (ret < 0) {
 233             fprintf(stderr, "copying failed\n");
 234             exit(-1);
 235         }
 236         i += ret;
 237     }
 238 }
 239
 240 int main(int argc, char **argv)
 241 {
 242     int out_fd, in_fd;
 243
 244     if (argc < 3)
 245         help();
 246
 247     in_fd = open_vmdk(argv[1]);
 248     if (in_fd < 0) {
 249         return -1;
 250     }
 251
 252     out_fd = open(argv[2], O_WRONLY | O_LARGEFILE | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
 253     if (out_fd < 0) {
 254         perror(argv[2]);
 255         return -1;
 256     }
 257
 258     copy_disk(in_fd, out_fd);
 259     close(out_fd);
 260     return 0;
 261 }