qemu-nbd.c

   1 /*\
   2  *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
   3  *
   4  *  Network Block Device
   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; under version 2 of the License.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include <qemu-common.h>
  21 #include "block_int.h"
  22 #include "nbd.h"
  23
  24 #include <stdarg.h>
  25 #include <stdio.h>
  26 #include <getopt.h>
  27 #include <err.h>
  28 #include <sys/socket.h>
  29 #include <netinet/in.h>
  30 #include <netinet/tcp.h>
  31 #include <arpa/inet.h>
  32
  33 int verbose;
  34
  35 static void usage(const char *name)
  36 {
  37     printf(
  38 "Usage: %s [OPTIONS] FILE\n"
  39 "QEMU Disk Network Block Device Server\n"
  40 "\n"
  41 "  -p, --port=PORT      port to listen on (default `1024')\n"
  42 "  -o, --offset=OFFSET  offset into the image\n"
  43 "  -b, --bind=IFACE     interface to bind to (default `0.0.0.0')\n"
  44 "  -r, --read-only      export read-only\n"
  45 "  -P, --partition=NUM  only expose partition NUM\n"
  46 "  -v, --verbose        display extra debugging information\n"
  47 "  -h, --help           display this help and exit\n"
  48 "  -V, --version        output version information and exit\n"
  49 "\n"
  50 "Report bugs to <anthony@codemonkey.ws>\n"
  51     , name);
  52 }
  53
  54 static void version(const char *name)
  55 {
  56     printf(
  57 "qemu-nbd version 0.0.1\n"
  58 "Written by Anthony Liguori.\n"
  59 "\n"
  60 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
  61 "This is free software; see the source for copying conditions.  There is NO\n"
  62 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
  63     );
  64 }
  65
  66 struct partition_record
  67 {
  68     uint8_t bootable;
  69     uint8_t start_head;
  70     uint32_t start_cylinder;
  71     uint8_t start_sector;
  72     uint8_t system;
  73     uint8_t end_head;
  74     uint8_t end_cylinder;
  75     uint8_t end_sector;
  76     uint32_t start_sector_abs;
  77     uint32_t nb_sectors_abs;
  78 };
  79
  80 static void read_partition(uint8_t *p, struct partition_record *r)
  81 {
  82     r->bootable = p[0];
  83     r->start_head = p[1];
  84     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
  85     r->start_sector = p[2] & 0x3f;
  86     r->system = p[4];
  87     r->end_head = p[5];
  88     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
  89     r->end_sector = p[6] & 0x3f;
  90     r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24;
  91     r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24;
  92 }
  93
  94 static int find_partition(BlockDriverState *bs, int partition,
  95                           off_t *offset, off_t *size)
  96 {
  97     struct partition_record mbr[4];
  98     uint8_t data[512];
  99     int i;
 100     int ext_partnum = 4;
 101
 102     if (bdrv_read(bs, 0, data, 1))
 103         errx(EINVAL, "error while reading");
 104
 105     if (data[510] != 0x55 || data[511] != 0xaa) {
 106         errno = -EINVAL;
 107         return -1;
 108     }
 109
 110     for (i = 0; i < 4; i++) {
 111         read_partition(&data[446 + 16 * i], &mbr[i]);
 112
 113         if (!mbr[i].nb_sectors_abs)
 114             continue;
 115
 116         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
 117             struct partition_record ext[4];
 118             uint8_t data1[512];
 119             int j;
 120
 121             if (bdrv_read(bs, mbr[i].start_sector_abs, data1, 1))
 122                 errx(EINVAL, "error while reading");
 123
 124             for (j = 0; j < 4; j++) {
 125                 read_partition(&data1[446 + 16 * j], &ext[j]);
 126                 if (!ext[j].nb_sectors_abs)
 127                     continue;
 128
 129                 if ((ext_partnum + j + 1) == partition) {
 130                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
 131                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
 132                     return 0;
 133                 }
 134             }
 135             ext_partnum += 4;
 136         } else if ((i + 1) == partition) {
 137             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
 138             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
 139             return 0;
 140         }
 141     }
 142
 143     errno = -ENOENT;
 144     return -1;
 145 }
 146
 147 int main(int argc, char **argv)
 148 {
 149     BlockDriverState *bs;
 150     off_t dev_offset = 0;
 151     off_t offset = 0;
 152     bool readonly = false;
 153     const char *bindto = "0.0.0.0";
 154     int port = 1024;
 155     int sock, csock;
 156     struct sockaddr_in addr;
 157     socklen_t addr_len = sizeof(addr);
 158     off_t fd_size;
 159     const char *sopt = "hVbo:p:rsP:v";
 160     struct option lopt[] = {
 161         { "help", 0, 0, 'h' },
 162         { "version", 0, 0, 'V' },
 163         { "bind", 1, 0, 'b' },
 164         { "port", 1, 0, 'p' },
 165         { "offset", 1, 0, 'o' },
 166         { "read-only", 0, 0, 'r' },
 167         { "partition", 1, 0, 'P' },
 168         { "snapshot", 0, 0, 's' },
 169         { "verbose", 0, 0, 'v' },
 170         { NULL, 0, 0, 0 }
 171     };
 172     int ch;
 173     int opt_ind = 0;
 174     int li;
 175     char *end;
 176     bool snapshot = false;
 177     int partition = -1;
 178
 179     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 180         switch (ch) {
 181         case 's':
 182             snapshot = true;
 183             break;
 184         case 'b':
 185             bindto = optarg;
 186             break;
 187         case 'p':
 188             li = strtol(optarg, &end, 0);
 189             if (*end) {
 190                 errx(EINVAL, "Invalid port `%s'", optarg);
 191             }
 192             if (li < 1 || li > 65535) {
 193                 errx(EINVAL, "Port out of range `%s'", optarg);
 194             }
 195             port = (uint16_t)li;
 196             break;
 197         case 'o':
 198                 dev_offset = strtoll (optarg, &end, 0);
 199             if (*end) {
 200                 errx(EINVAL, "Invalid offset `%s'", optarg);
 201             }
 202             if (dev_offset < 0) {
 203                 errx(EINVAL, "Offset must be positive `%s'", optarg);
 204             }
 205             break;
 206         case 'r':
 207             readonly = true;
 208             break;
 209         case 'P':
 210             partition = strtol(optarg, &end, 0);
 211             if (*end)
 212                 errx(EINVAL, "Invalid partition `%s'", optarg);
 213             if (partition < 1 || partition > 8)
 214                 errx(EINVAL, "Invalid partition %d", partition);
 215             break;
 216         case 'v':
 217             verbose = 1;
 218             break;
 219         case 'V':
 220             version(argv[0]);
 221             exit(0);
 222             break;
 223         case 'h':
 224             usage(argv[0]);
 225             exit(0);
 226             break;
 227         case '?':
 228             errx(EINVAL, "Try `%s --help' for more information.",
 229                  argv[0]);
 230         }
 231     }
 232
 233     if ((argc - optind) != 1) {
 234         errx(EINVAL, "Invalid number of argument.\n"
 235              "Try `%s --help' for more information.",
 236              argv[0]);
 237     }
 238
 239     bdrv_init();
 240
 241     bs = bdrv_new("hda");
 242     if (bs == NULL)
 243         return 1;
 244
 245     if (bdrv_open(bs, argv[optind], snapshot) == -1)
 246         return 1;
 247
 248     fd_size = bs->total_sectors * 512;
 249
 250     if (partition != -1 &&
 251         find_partition(bs, partition, &dev_offset, &fd_size))
 252         errx(errno, "Could not find partition %d", partition);
 253
 254     sock = tcp_socket_incoming(bindto, port);
 255     if (sock == -1)
 256         return 1;
 257
 258     csock = accept(sock,
 259                (struct sockaddr *)&addr,
 260                &addr_len);
 261     if (csock == -1)
 262         return 1;
 263
 264     /* new fd_size is calculated by find_partition */
 265     if (nbd_negotiate(bs, csock, fd_size) == -1)
 266         return 1;
 267
 268     while (nbd_trip(bs, csock, fd_size, dev_offset, &offset, readonly) == 0);
 269
 270     close(csock);
 271     close(sock);
 272     bdrv_close(bs);
 273
 274     return 0;
 275 }