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