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, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #include <qemu-common.h> 20 #include "block_int.h" 21 #include "nbd.h" 22 23 #include <stdarg.h> 24 #include <stdio.h> 25 #include <getopt.h> 26 #include <err.h> 27 #include <sys/types.h> 28 #include <sys/socket.h> 29 #include <netinet/in.h> 30 #include <netinet/tcp.h> 31 #include <arpa/inet.h> 32 #include <signal.h> 33 34 #define SOCKET_PATH "/var/lock/qemu-nbd-%s" 35 36 #define NBD_BUFFER_SIZE (1024*1024) 37 38 static int verbose; 39 40 static void usage(const char *name) 41 { 42 printf( 43 "Usage: %s [OPTIONS] FILE\n" 44 "QEMU Disk Network Block Device Server\n" 45 "\n" 46 " -p, --port=PORT port to listen on (default `1024')\n" 47 " -o, --offset=OFFSET offset into the image\n" 48 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n" 49 " -k, --socket=PATH path to the unix socket\n" 50 " (default '"SOCKET_PATH"')\n" 51 " -r, --read-only export read-only\n" 52 " -P, --partition=NUM only expose partition NUM\n" 53 " -s, --snapshot use snapshot file\n" 54 " -n, --nocache disable host cache\n" 55 " -c, --connect=DEV connect FILE to the local NBD device DEV\n" 56 " -d, --disconnect disconnect the specified device\n" 57 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n" 58 " -t, --persistent don't exit on the last connection\n" 59 " -v, --verbose display extra debugging information\n" 60 " -h, --help display this help and exit\n" 61 " -V, --version output version information and exit\n" 62 "\n" 63 "Report bugs to <anthony@codemonkey.ws>\n" 64 , name, "DEVICE"); 65 } 66 67 static void version(const char *name) 68 { 69 printf( 70 "%s version 0.0.1\n" 71 "Written by Anthony Liguori.\n" 72 "\n" 73 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n" 74 "This is free software; see the source for copying conditions. There is NO\n" 75 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" 76 , name); 77 } 78 79 struct partition_record 80 { 81 uint8_t bootable; 82 uint8_t start_head; 83 uint32_t start_cylinder; 84 uint8_t start_sector; 85 uint8_t system; 86 uint8_t end_head; 87 uint8_t end_cylinder; 88 uint8_t end_sector; 89 uint32_t start_sector_abs; 90 uint32_t nb_sectors_abs; 91 }; 92 93 static void read_partition(uint8_t *p, struct partition_record *r) 94 { 95 r->bootable = p[0]; 96 r->start_head = p[1]; 97 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); 98 r->start_sector = p[2] & 0x3f; 99 r->system = p[4]; 100 r->end_head = p[5]; 101 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); 102 r->end_sector = p[6] & 0x3f; 103 r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24; 104 r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24; 105 } 106 107 static int find_partition(BlockDriverState *bs, int partition, 108 off_t *offset, off_t *size) 109 { 110 struct partition_record mbr[4]; 111 uint8_t data[512]; 112 int i; 113 int ext_partnum = 4; 114 115 if (bdrv_read(bs, 0, data, 1)) 116 errx(EINVAL, "error while reading"); 117 118 if (data[510] != 0x55 || data[511] != 0xaa) { 119 errno = -EINVAL; 120 return -1; 121 } 122 123 for (i = 0; i < 4; i++) { 124 read_partition(&data[446 + 16 * i], &mbr[i]); 125 126 if (!mbr[i].nb_sectors_abs) 127 continue; 128 129 if (mbr[i].system == 0xF || mbr[i].system == 0x5) { 130 struct partition_record ext[4]; 131 uint8_t data1[512]; 132 int j; 133 134 if (bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) 135 errx(EINVAL, "error while reading"); 136 137 for (j = 0; j < 4; j++) { 138 read_partition(&data1[446 + 16 * j], &ext[j]); 139 if (!ext[j].nb_sectors_abs) 140 continue; 141 142 if ((ext_partnum + j + 1) == partition) { 143 *offset = (uint64_t)ext[j].start_sector_abs << 9; 144 *size = (uint64_t)ext[j].nb_sectors_abs << 9; 145 return 0; 146 } 147 } 148 ext_partnum += 4; 149 } else if ((i + 1) == partition) { 150 *offset = (uint64_t)mbr[i].start_sector_abs << 9; 151 *size = (uint64_t)mbr[i].nb_sectors_abs << 9; 152 return 0; 153 } 154 } 155 156 errno = -ENOENT; 157 return -1; 158 } 159 160 static void show_parts(const char *device) 161 { 162 if (fork() == 0) { 163 int nbd; 164 165 /* linux just needs an open() to trigger 166 * the partition table update 167 * but remember to load the module with max_part != 0 : 168 * modprobe nbd max_part=63 169 */ 170 nbd = open(device, O_RDWR); 171 if (nbd != -1) 172 close(nbd); 173 exit(0); 174 } 175 } 176 177 int main(int argc, char **argv) 178 { 179 BlockDriverState *bs; 180 off_t dev_offset = 0; 181 off_t offset = 0; 182 bool readonly = false; 183 bool disconnect = false; 184 const char *bindto = "0.0.0.0"; 185 int port = 1024; 186 struct sockaddr_in addr; 187 socklen_t addr_len = sizeof(addr); 188 off_t fd_size; 189 char *device = NULL; 190 char *socket = NULL; 191 char sockpath[128]; 192 const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t"; 193 struct option lopt[] = { 194 { "help", 0, NULL, 'h' }, 195 { "version", 0, NULL, 'V' }, 196 { "bind", 1, NULL, 'b' }, 197 { "port", 1, NULL, 'p' }, 198 { "socket", 1, NULL, 'k' }, 199 { "offset", 1, NULL, 'o' }, 200 { "read-only", 0, NULL, 'r' }, 201 { "partition", 1, NULL, 'P' }, 202 { "connect", 1, NULL, 'c' }, 203 { "disconnect", 0, NULL, 'd' }, 204 { "snapshot", 0, NULL, 's' }, 205 { "nocache", 0, NULL, 'n' }, 206 { "shared", 1, NULL, 'e' }, 207 { "persistent", 0, NULL, 't' }, 208 { "verbose", 0, NULL, 'v' }, 209 { NULL, 0, NULL, 0 } 210 }; 211 int ch; 212 int opt_ind = 0; 213 int li; 214 char *end; 215 int flags = 0; 216 int partition = -1; 217 int ret; 218 int shared = 1; 219 uint8_t *data; 220 fd_set fds; 221 int *sharing_fds; 222 int fd; 223 int i; 224 int nb_fds = 0; 225 int max_fd; 226 int persistent = 0; 227 228 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { 229 switch (ch) { 230 case 's': 231 flags |= BDRV_O_SNAPSHOT; 232 break; 233 case 'n': 234 flags |= BDRV_O_NOCACHE; 235 break; 236 case 'b': 237 bindto = optarg; 238 break; 239 case 'p': 240 li = strtol(optarg, &end, 0); 241 if (*end) { 242 errx(EINVAL, "Invalid port `%s'", optarg); 243 } 244 if (li < 1 || li > 65535) { 245 errx(EINVAL, "Port out of range `%s'", optarg); 246 } 247 port = (uint16_t)li; 248 break; 249 case 'o': 250 dev_offset = strtoll (optarg, &end, 0); 251 if (*end) { 252 errx(EINVAL, "Invalid offset `%s'", optarg); 253 } 254 if (dev_offset < 0) { 255 errx(EINVAL, "Offset must be positive `%s'", optarg); 256 } 257 break; 258 case 'r': 259 readonly = true; 260 break; 261 case 'P': 262 partition = strtol(optarg, &end, 0); 263 if (*end) 264 errx(EINVAL, "Invalid partition `%s'", optarg); 265 if (partition < 1 || partition > 8) 266 errx(EINVAL, "Invalid partition %d", partition); 267 break; 268 case 'k': 269 socket = optarg; 270 if (socket[0] != '/') 271 errx(EINVAL, "socket path must be absolute\n"); 272 break; 273 case 'd': 274 disconnect = true; 275 break; 276 case 'c': 277 device = optarg; 278 break; 279 case 'e': 280 shared = strtol(optarg, &end, 0); 281 if (*end) { 282 errx(EINVAL, "Invalid shared device number '%s'", optarg); 283 } 284 if (shared < 1) { 285 errx(EINVAL, "Shared device number must be greater than 0\n"); 286 } 287 break; 288 case 't': 289 persistent = 1; 290 break; 291 case 'v': 292 verbose = 1; 293 break; 294 case 'V': 295 version(argv[0]); 296 exit(0); 297 break; 298 case 'h': 299 usage(argv[0]); 300 exit(0); 301 break; 302 case '?': 303 errx(EINVAL, "Try `%s --help' for more information.", 304 argv[0]); 305 } 306 } 307 308 if ((argc - optind) != 1) { 309 errx(EINVAL, "Invalid number of argument.\n" 310 "Try `%s --help' for more information.", 311 argv[0]); 312 } 313 314 if (disconnect) { 315 fd = open(argv[optind], O_RDWR); 316 if (fd == -1) 317 errx(errno, "Cannot open %s", argv[optind]); 318 319 nbd_disconnect(fd); 320 321 close(fd); 322 323 printf("%s disconnected\n", argv[optind]); 324 325 return 0; 326 } 327 328 bdrv_init(); 329 330 bs = bdrv_new("hda"); 331 if (bs == NULL) 332 return 1; 333 334 if (bdrv_open(bs, argv[optind], flags) == -1) 335 return 1; 336 337 fd_size = bs->total_sectors * 512; 338 339 if (partition != -1 && 340 find_partition(bs, partition, &dev_offset, &fd_size)) 341 errx(errno, "Could not find partition %d", partition); 342 343 if (device) { 344 pid_t pid; 345 int sock; 346 347 if (!verbose) { 348 /* detach client and server */ 349 if (daemon(0, 0) == -1) { 350 errx(errno, "Failed to daemonize"); 351 } 352 } 353 354 if (socket == NULL) { 355 sprintf(sockpath, SOCKET_PATH, basename(device)); 356 socket = sockpath; 357 } 358 359 pid = fork(); 360 if (pid < 0) 361 return 1; 362 if (pid != 0) { 363 off_t size; 364 size_t blocksize; 365 366 ret = 0; 367 bdrv_close(bs); 368 369 do { 370 sock = unix_socket_outgoing(socket); 371 if (sock == -1) { 372 if (errno != ENOENT && errno != ECONNREFUSED) 373 goto out; 374 sleep(1); /* wait children */ 375 } 376 } while (sock == -1); 377 378 fd = open(device, O_RDWR); 379 if (fd == -1) { 380 ret = 1; 381 goto out; 382 } 383 384 ret = nbd_receive_negotiate(sock, &size, &blocksize); 385 if (ret == -1) { 386 ret = 1; 387 goto out; 388 } 389 390 ret = nbd_init(fd, sock, size, blocksize); 391 if (ret == -1) { 392 ret = 1; 393 goto out; 394 } 395 396 printf("NBD device %s is now connected to file %s\n", 397 device, argv[optind]); 398 399 /* update partition table */ 400 401 show_parts(device); 402 403 nbd_client(fd, sock); 404 close(fd); 405 out: 406 kill(pid, SIGTERM); 407 unlink(socket); 408 409 return ret; 410 } 411 /* children */ 412 } 413 414 sharing_fds = qemu_malloc((shared + 1) * sizeof(int)); 415 416 if (socket) { 417 sharing_fds[0] = unix_socket_incoming(socket); 418 } else { 419 sharing_fds[0] = tcp_socket_incoming(bindto, port); 420 } 421 422 if (sharing_fds[0] == -1) 423 return 1; 424 max_fd = sharing_fds[0]; 425 nb_fds++; 426 427 data = qemu_memalign(512, NBD_BUFFER_SIZE); 428 if (data == NULL) 429 errx(ENOMEM, "Cannot allocate data buffer"); 430 431 do { 432 433 FD_ZERO(&fds); 434 for (i = 0; i < nb_fds; i++) 435 FD_SET(sharing_fds[i], &fds); 436 437 ret = select(max_fd + 1, &fds, NULL, NULL, NULL); 438 if (ret == -1) 439 break; 440 441 if (FD_ISSET(sharing_fds[0], &fds)) 442 ret--; 443 for (i = 1; i < nb_fds && ret; i++) { 444 if (FD_ISSET(sharing_fds[i], &fds)) { 445 if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset, 446 &offset, readonly, data, NBD_BUFFER_SIZE) != 0) { 447 close(sharing_fds[i]); 448 nb_fds--; 449 sharing_fds[i] = sharing_fds[nb_fds]; 450 i--; 451 } 452 ret--; 453 } 454 } 455 /* new connection ? */ 456 if (FD_ISSET(sharing_fds[0], &fds)) { 457 if (nb_fds < shared + 1) { 458 sharing_fds[nb_fds] = accept(sharing_fds[0], 459 (struct sockaddr *)&addr, 460 &addr_len); 461 if (sharing_fds[nb_fds] != -1 && 462 nbd_negotiate(sharing_fds[nb_fds], fd_size) != -1) { 463 if (sharing_fds[nb_fds] > max_fd) 464 max_fd = sharing_fds[nb_fds]; 465 nb_fds++; 466 } 467 } 468 } 469 } while (persistent || nb_fds > 1); 470 qemu_free(data); 471 472 close(sharing_fds[0]); 473 bdrv_close(bs); 474 qemu_free(sharing_fds); 475 if (socket) 476 unlink(socket); 477 478 return 0; 479 } 480