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 struct cowdisk_header header;
  34 struct cowdisk_header2 header2;
  35 off_t disk_base, disk_limit;
  36 unsigned int granule_size;
  37 uint32_t l1dir[L1_SIZE];
  38
  39 unsigned int cached_l2dir;
  40 uint32_t l2dir[L2_SIZE];
  41
  42 size_t read_physical(int fd, off64_t offset, size_t length, void *buffer)
  43 {
  44     size_t n;
  45
  46     if (lseek64(fd, offset, SEEK_SET) == -1)
  47     {
  48         perror("lseek");
  49         return -1;
  50     }
  51
  52     n = read(fd, buffer, length);
  53     if (n == -1)
  54     {
  55         perror("read from disk");
  56         return -1;
  57     }
  58
  59     return n;
  60 }
  61
  62 size_t copy_virtual(int in_fd, int out_fd, off64_t offset, void *buffer, size_t length)
  63 {
  64     unsigned int granule_index, granule_offset;
  65     unsigned int l1index, l2index;
  66
  67     granule_index = offset / granule_size;
  68     granule_offset = offset % granule_size;
  69     length = MIN(length, granule_size - granule_offset);
  70     length = MIN(length, disk_limit - offset);
  71
  72     l1index = (granule_index >> L2_BITS) & L1_MASK;
  73     l2index = granule_index & L2_MASK;
  74
  75     if (l1dir[l1index] == 0)
  76         goto zero_fill;
  77
  78     if (l1index != cached_l2dir)
  79     {
  80         if (read_physical(in_fd, (l1dir[l1index] << SECTOR_BITS), sizeof(l2dir), (char *)l2dir) != sizeof(l2dir))
  81             return 0;
  82
  83         cached_l2dir = l1index;
  84     }
  85
  86     if (l2dir[l2index] == 0)
  87         goto zero_fill;
  88
  89     if (read_physical(in_fd, (l2dir[l2index] << SECTOR_BITS) + granule_offset, length, buffer) != length)
  90         return 0;
  91
  92     write(out_fd, buffer, length);
  93     return length;
  94
  95 zero_fill:
  96     /* the last chunk of the file can not be sparse
  97      * or the file will be truncated */
  98     if (offset + length < disk_limit) {
  99         memset(buffer, 0, length);
 100         write(out_fd, buffer, length);
 101     } else {
 102         if (lseek(out_fd, length, SEEK_CUR) == (off_t)-1)
 103             perror("lseek");
 104     }
 105     return length;
 106 }
 107
 108
 109 int open_vmdk(const char *filename)
 110 {
 111     int fd = open(filename, O_RDONLY | O_LARGEFILE);
 112     if (fd == -1)
 113     {
 114         perror(filename);
 115         return -1;
 116     }
 117
 118     if (read(fd, &header, sizeof(header)) != sizeof(header))
 119     {
 120         perror("read from disk");
 121         return -1;
 122     }
 123
 124     if (memcmp(header.magic, "COWD", 4) != 0)
 125     {
 126         fprintf(stderr, "%s is not a VMware virtual disk image\n", filename);
 127         return -1;
 128     }
 129
 130     granule_size = header.granularity << SECTOR_BITS;
 131     if (read_physical(fd, header.l1dir_sector << SECTOR_BITS, sizeof(l1dir), (char *)l1dir) != sizeof(l1dir))
 132         return -1;
 133
 134     disk_limit = header.disk_sectors << SECTOR_BITS;
 135
 136     cached_l2dir = -1;
 137     return fd;
 138 }
 139
 140 void help(void)
 141 {
 142     printf("vmdk2raw\n"
 143            "usage: vmdk2raw vmware_image output_image\n"
 144            "\n"
 145            "vmware_image   a vmware 2.x/3.x cow image\n"
 146            "output_image   the created disk image\n"
 147           );
 148     exit(1);
 149 }
 150
 151 #define BUF_SIZE granule_size
 152 void copy_disk(in_fd, out_fd)
 153 {
 154     char buf[BUF_SIZE];
 155     off64_t i = 0;
 156     while (i < disk_limit) {
 157         i += copy_virtual(in_fd, out_fd, i, buf, sizeof(buf));
 158     }
 159 }
 160
 161 int main(int argc, char **argv)
 162 {
 163     int out_fd, in_fd;
 164
 165     if (argc < 3)
 166         help();
 167
 168     in_fd = open_vmdk(argv[1]);
 169     if (in_fd < 0) {
 170         return -1;
 171     }
 172
 173     out_fd = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
 174     if (out_fd < 0) {
 175         perror(argv[2]);
 176         return -1;
 177     }
 178
 179     copy_disk(in_fd, out_fd);
 180     close(out_fd);
 181     return 0;
 182 }