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/osdep.h" 20 #include "qemu-common.h" 21 #include "sysemu/block-backend.h" 22 #include "block/block_int.h" 23 #include "block/nbd.h" 24 #include "qemu/main-loop.h" 25 #include "qemu/error-report.h" 26 #include "qemu/config-file.h" 27 #include "block/snapshot.h" 28 #include "qapi/util.h" 29 #include "qapi/qmp/qstring.h" 30 #include "qom/object_interfaces.h" 31 #include "io/channel-socket.h" 32 33 #include <getopt.h> 34 #include <sys/types.h> 35 #include <signal.h> 36 #include <libgen.h> 37 #include <pthread.h> 38 39 #define SOCKET_PATH "/var/lock/qemu-nbd-%s" 40 #define QEMU_NBD_OPT_CACHE 1 41 #define QEMU_NBD_OPT_AIO 2 42 #define QEMU_NBD_OPT_DISCARD 3 43 #define QEMU_NBD_OPT_DETECT_ZEROES 4 44 #define QEMU_NBD_OPT_OBJECT 5 45 #define QEMU_NBD_OPT_TLSCREDS 6 46 47 static NBDExport *exp; 48 static bool newproto; 49 static int verbose; 50 static char *srcpath; 51 static SocketAddress *saddr; 52 static int persistent = 0; 53 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state; 54 static int shared = 1; 55 static int nb_fds; 56 static QIOChannelSocket *server_ioc; 57 static int server_watch = -1; 58 static QCryptoTLSCreds *tlscreds; 59 60 static void usage(const char *name) 61 { 62 (printf) ( 63 "Usage: %s [OPTIONS] FILE\n" 64 "QEMU Disk Network Block Device Server\n" 65 "\n" 66 " -h, --help display this help and exit\n" 67 " -V, --version output version information and exit\n" 68 "\n" 69 "Connection properties:\n" 70 " -p, --port=PORT port to listen on (default `%d')\n" 71 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n" 72 " -k, --socket=PATH path to the unix socket\n" 73 " (default '"SOCKET_PATH"')\n" 74 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n" 75 " -t, --persistent don't exit on the last connection\n" 76 " -v, --verbose display extra debugging information\n" 77 "\n" 78 "Exposing part of the image:\n" 79 " -o, --offset=OFFSET offset into the image\n" 80 " -P, --partition=NUM only expose partition NUM\n" 81 "\n" 82 "General purpose options:\n" 83 " --object type,id=ID,... define an object such as 'secret' for providing\n" 84 " passwords and/or encryption keys\n" 85 #ifdef __linux__ 86 "Kernel NBD client support:\n" 87 " -c, --connect=DEV connect FILE to the local NBD device DEV\n" 88 " -d, --disconnect disconnect the specified device\n" 89 "\n" 90 #endif 91 "\n" 92 "Block device options:\n" 93 " -f, --format=FORMAT set image format (raw, qcow2, ...)\n" 94 " -r, --read-only export read-only\n" 95 " -s, --snapshot use FILE as an external snapshot, create a temporary\n" 96 " file with backing_file=FILE, redirect the write to\n" 97 " the temporary one\n" 98 " -l, --load-snapshot=SNAPSHOT_PARAM\n" 99 " load an internal snapshot inside FILE and export it\n" 100 " as an read-only device, SNAPSHOT_PARAM format is\n" 101 " 'snapshot.id=[ID],snapshot.name=[NAME]', or\n" 102 " '[ID_OR_NAME]'\n" 103 " -n, --nocache disable host cache\n" 104 " --cache=MODE set cache mode (none, writeback, ...)\n" 105 " --aio=MODE set AIO mode (native or threads)\n" 106 " --discard=MODE set discard mode (ignore, unmap)\n" 107 " --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n" 108 "\n" 109 "Report bugs to <qemu-devel@nongnu.org>\n" 110 , name, NBD_DEFAULT_PORT, "DEVICE"); 111 } 112 113 static void version(const char *name) 114 { 115 printf( 116 "%s version 0.0.1\n" 117 "Written by Anthony Liguori.\n" 118 "\n" 119 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n" 120 "This is free software; see the source for copying conditions. There is NO\n" 121 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" 122 , name); 123 } 124 125 struct partition_record 126 { 127 uint8_t bootable; 128 uint8_t start_head; 129 uint32_t start_cylinder; 130 uint8_t start_sector; 131 uint8_t system; 132 uint8_t end_head; 133 uint8_t end_cylinder; 134 uint8_t end_sector; 135 uint32_t start_sector_abs; 136 uint32_t nb_sectors_abs; 137 }; 138 139 static void read_partition(uint8_t *p, struct partition_record *r) 140 { 141 r->bootable = p[0]; 142 r->start_head = p[1]; 143 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); 144 r->start_sector = p[2] & 0x3f; 145 r->system = p[4]; 146 r->end_head = p[5]; 147 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); 148 r->end_sector = p[6] & 0x3f; 149 150 r->start_sector_abs = le32_to_cpup((uint32_t *)(p + 8)); 151 r->nb_sectors_abs = le32_to_cpup((uint32_t *)(p + 12)); 152 } 153 154 static int find_partition(BlockBackend *blk, int partition, 155 off_t *offset, off_t *size) 156 { 157 struct partition_record mbr[4]; 158 uint8_t data[512]; 159 int i; 160 int ext_partnum = 4; 161 int ret; 162 163 if ((ret = blk_read(blk, 0, data, 1)) < 0) { 164 error_report("error while reading: %s", strerror(-ret)); 165 exit(EXIT_FAILURE); 166 } 167 168 if (data[510] != 0x55 || data[511] != 0xaa) { 169 return -EINVAL; 170 } 171 172 for (i = 0; i < 4; i++) { 173 read_partition(&data[446 + 16 * i], &mbr[i]); 174 175 if (!mbr[i].system || !mbr[i].nb_sectors_abs) { 176 continue; 177 } 178 179 if (mbr[i].system == 0xF || mbr[i].system == 0x5) { 180 struct partition_record ext[4]; 181 uint8_t data1[512]; 182 int j; 183 184 if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) { 185 error_report("error while reading: %s", strerror(-ret)); 186 exit(EXIT_FAILURE); 187 } 188 189 for (j = 0; j < 4; j++) { 190 read_partition(&data1[446 + 16 * j], &ext[j]); 191 if (!ext[j].system || !ext[j].nb_sectors_abs) { 192 continue; 193 } 194 195 if ((ext_partnum + j + 1) == partition) { 196 *offset = (uint64_t)ext[j].start_sector_abs << 9; 197 *size = (uint64_t)ext[j].nb_sectors_abs << 9; 198 return 0; 199 } 200 } 201 ext_partnum += 4; 202 } else if ((i + 1) == partition) { 203 *offset = (uint64_t)mbr[i].start_sector_abs << 9; 204 *size = (uint64_t)mbr[i].nb_sectors_abs << 9; 205 return 0; 206 } 207 } 208 209 return -ENOENT; 210 } 211 212 static void termsig_handler(int signum) 213 { 214 state = TERMINATE; 215 qemu_notify_event(); 216 } 217 218 219 static void *show_parts(void *arg) 220 { 221 char *device = arg; 222 int nbd; 223 224 /* linux just needs an open() to trigger 225 * the partition table update 226 * but remember to load the module with max_part != 0 : 227 * modprobe nbd max_part=63 228 */ 229 nbd = open(device, O_RDWR); 230 if (nbd >= 0) { 231 close(nbd); 232 } 233 return NULL; 234 } 235 236 static void *nbd_client_thread(void *arg) 237 { 238 char *device = arg; 239 off_t size; 240 uint32_t nbdflags; 241 QIOChannelSocket *sioc; 242 int fd; 243 int ret; 244 pthread_t show_parts_thread; 245 Error *local_error = NULL; 246 247 sioc = qio_channel_socket_new(); 248 if (qio_channel_socket_connect_sync(sioc, 249 saddr, 250 &local_error) < 0) { 251 error_report_err(local_error); 252 goto out; 253 } 254 255 ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, &nbdflags, 256 NULL, NULL, NULL, 257 &size, &local_error); 258 if (ret < 0) { 259 if (local_error) { 260 error_report_err(local_error); 261 } 262 goto out_socket; 263 } 264 265 fd = open(device, O_RDWR); 266 if (fd < 0) { 267 /* Linux-only, we can use %m in printf. */ 268 error_report("Failed to open %s: %m", device); 269 goto out_socket; 270 } 271 272 ret = nbd_init(fd, sioc, nbdflags, size); 273 if (ret < 0) { 274 goto out_fd; 275 } 276 277 /* update partition table */ 278 pthread_create(&show_parts_thread, NULL, show_parts, device); 279 280 if (verbose) { 281 fprintf(stderr, "NBD device %s is now connected to %s\n", 282 device, srcpath); 283 } else { 284 /* Close stderr so that the qemu-nbd process exits. */ 285 dup2(STDOUT_FILENO, STDERR_FILENO); 286 } 287 288 ret = nbd_client(fd); 289 if (ret) { 290 goto out_fd; 291 } 292 close(fd); 293 object_unref(OBJECT(sioc)); 294 kill(getpid(), SIGTERM); 295 return (void *) EXIT_SUCCESS; 296 297 out_fd: 298 close(fd); 299 out_socket: 300 object_unref(OBJECT(sioc)); 301 out: 302 kill(getpid(), SIGTERM); 303 return (void *) EXIT_FAILURE; 304 } 305 306 static int nbd_can_accept(void) 307 { 308 return nb_fds < shared; 309 } 310 311 static void nbd_export_closed(NBDExport *exp) 312 { 313 assert(state == TERMINATING); 314 state = TERMINATED; 315 } 316 317 static void nbd_update_server_watch(void); 318 319 static void nbd_client_closed(NBDClient *client) 320 { 321 nb_fds--; 322 if (nb_fds == 0 && !persistent && state == RUNNING) { 323 state = TERMINATE; 324 } 325 nbd_update_server_watch(); 326 nbd_client_put(client); 327 } 328 329 static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque) 330 { 331 QIOChannelSocket *cioc; 332 333 cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc), 334 NULL); 335 if (!cioc) { 336 return TRUE; 337 } 338 339 if (state >= TERMINATE) { 340 object_unref(OBJECT(cioc)); 341 return TRUE; 342 } 343 344 nb_fds++; 345 nbd_update_server_watch(); 346 nbd_client_new(newproto ? NULL : exp, cioc, 347 tlscreds, NULL, nbd_client_closed); 348 object_unref(OBJECT(cioc)); 349 350 return TRUE; 351 } 352 353 static void nbd_update_server_watch(void) 354 { 355 if (nbd_can_accept()) { 356 if (server_watch == -1) { 357 server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc), 358 G_IO_IN, 359 nbd_accept, 360 NULL, NULL); 361 } 362 } else { 363 if (server_watch != -1) { 364 g_source_remove(server_watch); 365 server_watch = -1; 366 } 367 } 368 } 369 370 371 static SocketAddress *nbd_build_socket_address(const char *sockpath, 372 const char *bindto, 373 const char *port) 374 { 375 SocketAddress *saddr; 376 377 saddr = g_new0(SocketAddress, 1); 378 if (sockpath) { 379 saddr->type = SOCKET_ADDRESS_KIND_UNIX; 380 saddr->u.q_unix = g_new0(UnixSocketAddress, 1); 381 saddr->u.q_unix->path = g_strdup(sockpath); 382 } else { 383 saddr->type = SOCKET_ADDRESS_KIND_INET; 384 saddr->u.inet = g_new0(InetSocketAddress, 1); 385 saddr->u.inet->host = g_strdup(bindto); 386 if (port) { 387 saddr->u.inet->port = g_strdup(port); 388 } else { 389 saddr->u.inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT); 390 } 391 } 392 393 return saddr; 394 } 395 396 397 static QemuOptsList qemu_object_opts = { 398 .name = "object", 399 .implied_opt_name = "qom-type", 400 .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head), 401 .desc = { 402 { } 403 }, 404 }; 405 406 407 408 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 409 { 410 Object *obj; 411 QCryptoTLSCreds *creds; 412 413 obj = object_resolve_path_component( 414 object_get_objects_root(), id); 415 if (!obj) { 416 error_setg(errp, "No TLS credentials with id '%s'", 417 id); 418 return NULL; 419 } 420 creds = (QCryptoTLSCreds *) 421 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 422 if (!creds) { 423 error_setg(errp, "Object with id '%s' is not TLS credentials", 424 id); 425 return NULL; 426 } 427 428 if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) { 429 error_setg(errp, 430 "Expecting TLS credentials with a server endpoint"); 431 return NULL; 432 } 433 object_ref(obj); 434 return creds; 435 } 436 437 438 int main(int argc, char **argv) 439 { 440 BlockBackend *blk; 441 BlockDriverState *bs; 442 off_t dev_offset = 0; 443 uint32_t nbdflags = 0; 444 bool disconnect = false; 445 const char *bindto = "0.0.0.0"; 446 const char *port = NULL; 447 char *sockpath = NULL; 448 char *device = NULL; 449 off_t fd_size; 450 QemuOpts *sn_opts = NULL; 451 const char *sn_id_or_name = NULL; 452 const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:"; 453 struct option lopt[] = { 454 { "help", 0, NULL, 'h' }, 455 { "version", 0, NULL, 'V' }, 456 { "bind", 1, NULL, 'b' }, 457 { "port", 1, NULL, 'p' }, 458 { "socket", 1, NULL, 'k' }, 459 { "offset", 1, NULL, 'o' }, 460 { "read-only", 0, NULL, 'r' }, 461 { "partition", 1, NULL, 'P' }, 462 { "connect", 1, NULL, 'c' }, 463 { "disconnect", 0, NULL, 'd' }, 464 { "snapshot", 0, NULL, 's' }, 465 { "load-snapshot", 1, NULL, 'l' }, 466 { "nocache", 0, NULL, 'n' }, 467 { "cache", 1, NULL, QEMU_NBD_OPT_CACHE }, 468 { "aio", 1, NULL, QEMU_NBD_OPT_AIO }, 469 { "discard", 1, NULL, QEMU_NBD_OPT_DISCARD }, 470 { "detect-zeroes", 1, NULL, QEMU_NBD_OPT_DETECT_ZEROES }, 471 { "shared", 1, NULL, 'e' }, 472 { "format", 1, NULL, 'f' }, 473 { "persistent", 0, NULL, 't' }, 474 { "verbose", 0, NULL, 'v' }, 475 { "object", 1, NULL, QEMU_NBD_OPT_OBJECT }, 476 { "export-name", 1, NULL, 'x' }, 477 { "tls-creds", 1, NULL, QEMU_NBD_OPT_TLSCREDS }, 478 { NULL, 0, NULL, 0 } 479 }; 480 int ch; 481 int opt_ind = 0; 482 char *end; 483 int flags = BDRV_O_RDWR; 484 int partition = -1; 485 int ret = 0; 486 bool seen_cache = false; 487 bool seen_discard = false; 488 bool seen_aio = false; 489 pthread_t client_thread; 490 const char *fmt = NULL; 491 Error *local_err = NULL; 492 BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF; 493 QDict *options = NULL; 494 const char *export_name = NULL; 495 const char *tlscredsid = NULL; 496 497 /* The client thread uses SIGTERM to interrupt the server. A signal 498 * handler ensures that "qemu-nbd -v -c" exits with a nice status code. 499 */ 500 struct sigaction sa_sigterm; 501 memset(&sa_sigterm, 0, sizeof(sa_sigterm)); 502 sa_sigterm.sa_handler = termsig_handler; 503 sigaction(SIGTERM, &sa_sigterm, NULL); 504 module_call_init(MODULE_INIT_QOM); 505 qemu_add_opts(&qemu_object_opts); 506 qemu_init_exec_dir(argv[0]); 507 508 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { 509 switch (ch) { 510 case 's': 511 flags |= BDRV_O_SNAPSHOT; 512 break; 513 case 'n': 514 optarg = (char *) "none"; 515 /* fallthrough */ 516 case QEMU_NBD_OPT_CACHE: 517 if (seen_cache) { 518 error_report("-n and --cache can only be specified once"); 519 exit(EXIT_FAILURE); 520 } 521 seen_cache = true; 522 if (bdrv_parse_cache_flags(optarg, &flags) == -1) { 523 error_report("Invalid cache mode `%s'", optarg); 524 exit(EXIT_FAILURE); 525 } 526 break; 527 case QEMU_NBD_OPT_AIO: 528 if (seen_aio) { 529 error_report("--aio can only be specified once"); 530 exit(EXIT_FAILURE); 531 } 532 seen_aio = true; 533 if (!strcmp(optarg, "native")) { 534 flags |= BDRV_O_NATIVE_AIO; 535 } else if (!strcmp(optarg, "threads")) { 536 /* this is the default */ 537 } else { 538 error_report("invalid aio mode `%s'", optarg); 539 exit(EXIT_FAILURE); 540 } 541 break; 542 case QEMU_NBD_OPT_DISCARD: 543 if (seen_discard) { 544 error_report("--discard can only be specified once"); 545 exit(EXIT_FAILURE); 546 } 547 seen_discard = true; 548 if (bdrv_parse_discard_flags(optarg, &flags) == -1) { 549 error_report("Invalid discard mode `%s'", optarg); 550 exit(EXIT_FAILURE); 551 } 552 break; 553 case QEMU_NBD_OPT_DETECT_ZEROES: 554 detect_zeroes = 555 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup, 556 optarg, 557 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX, 558 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, 559 &local_err); 560 if (local_err) { 561 error_reportf_err(local_err, 562 "Failed to parse detect_zeroes mode: "); 563 exit(EXIT_FAILURE); 564 } 565 if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP && 566 !(flags & BDRV_O_UNMAP)) { 567 error_report("setting detect-zeroes to unmap is not allowed " 568 "without setting discard operation to unmap"); 569 exit(EXIT_FAILURE); 570 } 571 break; 572 case 'b': 573 bindto = optarg; 574 break; 575 case 'p': 576 port = optarg; 577 break; 578 case 'o': 579 dev_offset = strtoll (optarg, &end, 0); 580 if (*end) { 581 error_report("Invalid offset `%s'", optarg); 582 exit(EXIT_FAILURE); 583 } 584 if (dev_offset < 0) { 585 error_report("Offset must be positive `%s'", optarg); 586 exit(EXIT_FAILURE); 587 } 588 break; 589 case 'l': 590 if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) { 591 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts, 592 optarg, false); 593 if (!sn_opts) { 594 error_report("Failed in parsing snapshot param `%s'", 595 optarg); 596 exit(EXIT_FAILURE); 597 } 598 } else { 599 sn_id_or_name = optarg; 600 } 601 /* fall through */ 602 case 'r': 603 nbdflags |= NBD_FLAG_READ_ONLY; 604 flags &= ~BDRV_O_RDWR; 605 break; 606 case 'P': 607 partition = strtol(optarg, &end, 0); 608 if (*end) { 609 error_report("Invalid partition `%s'", optarg); 610 exit(EXIT_FAILURE); 611 } 612 if (partition < 1 || partition > 8) { 613 error_report("Invalid partition %d", partition); 614 exit(EXIT_FAILURE); 615 } 616 break; 617 case 'k': 618 sockpath = optarg; 619 if (sockpath[0] != '/') { 620 error_report("socket path must be absolute"); 621 exit(EXIT_FAILURE); 622 } 623 break; 624 case 'd': 625 disconnect = true; 626 break; 627 case 'c': 628 device = optarg; 629 break; 630 case 'e': 631 shared = strtol(optarg, &end, 0); 632 if (*end) { 633 error_report("Invalid shared device number '%s'", optarg); 634 exit(EXIT_FAILURE); 635 } 636 if (shared < 1) { 637 error_report("Shared device number must be greater than 0"); 638 exit(EXIT_FAILURE); 639 } 640 break; 641 case 'f': 642 fmt = optarg; 643 break; 644 case 't': 645 persistent = 1; 646 break; 647 case 'x': 648 export_name = optarg; 649 break; 650 case 'v': 651 verbose = 1; 652 break; 653 case 'V': 654 version(argv[0]); 655 exit(0); 656 break; 657 case 'h': 658 usage(argv[0]); 659 exit(0); 660 break; 661 case '?': 662 error_report("Try `%s --help' for more information.", argv[0]); 663 exit(EXIT_FAILURE); 664 case QEMU_NBD_OPT_OBJECT: { 665 QemuOpts *opts; 666 opts = qemu_opts_parse_noisily(&qemu_object_opts, 667 optarg, true); 668 if (!opts) { 669 exit(EXIT_FAILURE); 670 } 671 } break; 672 case QEMU_NBD_OPT_TLSCREDS: 673 tlscredsid = optarg; 674 break; 675 } 676 } 677 678 if ((argc - optind) != 1) { 679 error_report("Invalid number of arguments"); 680 error_printf("Try `%s --help' for more information.\n", argv[0]); 681 exit(EXIT_FAILURE); 682 } 683 684 if (qemu_opts_foreach(&qemu_object_opts, 685 user_creatable_add_opts_foreach, 686 NULL, &local_err)) { 687 error_report_err(local_err); 688 exit(EXIT_FAILURE); 689 } 690 691 if (tlscredsid) { 692 if (sockpath) { 693 error_report("TLS is only supported with IPv4/IPv6"); 694 exit(EXIT_FAILURE); 695 } 696 if (device) { 697 error_report("TLS is not supported with a host device"); 698 exit(EXIT_FAILURE); 699 } 700 if (!export_name) { 701 /* Set the default NBD protocol export name, since 702 * we *must* use new style protocol for TLS */ 703 export_name = ""; 704 } 705 tlscreds = nbd_get_tls_creds(tlscredsid, &local_err); 706 if (local_err) { 707 error_report("Failed to get TLS creds %s", 708 error_get_pretty(local_err)); 709 exit(EXIT_FAILURE); 710 } 711 } 712 713 if (disconnect) { 714 int nbdfd = open(argv[optind], O_RDWR); 715 if (nbdfd < 0) { 716 error_report("Cannot open %s: %s", argv[optind], 717 strerror(errno)); 718 exit(EXIT_FAILURE); 719 } 720 nbd_disconnect(nbdfd); 721 722 close(nbdfd); 723 724 printf("%s disconnected\n", argv[optind]); 725 726 return 0; 727 } 728 729 if (device && !verbose) { 730 int stderr_fd[2]; 731 pid_t pid; 732 int ret; 733 734 if (qemu_pipe(stderr_fd) < 0) { 735 error_report("Error setting up communication pipe: %s", 736 strerror(errno)); 737 exit(EXIT_FAILURE); 738 } 739 740 /* Now daemonize, but keep a communication channel open to 741 * print errors and exit with the proper status code. 742 */ 743 pid = fork(); 744 if (pid < 0) { 745 error_report("Failed to fork: %s", strerror(errno)); 746 exit(EXIT_FAILURE); 747 } else if (pid == 0) { 748 close(stderr_fd[0]); 749 ret = qemu_daemon(1, 0); 750 751 /* Temporarily redirect stderr to the parent's pipe... */ 752 dup2(stderr_fd[1], STDERR_FILENO); 753 if (ret < 0) { 754 error_report("Failed to daemonize: %s", strerror(errno)); 755 exit(EXIT_FAILURE); 756 } 757 758 /* ... close the descriptor we inherited and go on. */ 759 close(stderr_fd[1]); 760 } else { 761 bool errors = false; 762 char *buf; 763 764 /* In the parent. Print error messages from the child until 765 * it closes the pipe. 766 */ 767 close(stderr_fd[1]); 768 buf = g_malloc(1024); 769 while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { 770 errors = true; 771 ret = qemu_write_full(STDERR_FILENO, buf, ret); 772 if (ret < 0) { 773 exit(EXIT_FAILURE); 774 } 775 } 776 if (ret < 0) { 777 error_report("Cannot read from daemon: %s", 778 strerror(errno)); 779 exit(EXIT_FAILURE); 780 } 781 782 /* Usually the daemon should not print any message. 783 * Exit with zero status in that case. 784 */ 785 exit(errors); 786 } 787 } 788 789 if (device != NULL && sockpath == NULL) { 790 sockpath = g_malloc(128); 791 snprintf(sockpath, 128, SOCKET_PATH, basename(device)); 792 } 793 794 saddr = nbd_build_socket_address(sockpath, bindto, port); 795 796 if (qemu_init_main_loop(&local_err)) { 797 error_report_err(local_err); 798 exit(EXIT_FAILURE); 799 } 800 bdrv_init(); 801 atexit(bdrv_close_all); 802 803 if (fmt) { 804 options = qdict_new(); 805 qdict_put(options, "driver", qstring_from_str(fmt)); 806 } 807 808 srcpath = argv[optind]; 809 blk = blk_new_open("hda", srcpath, NULL, options, flags, &local_err); 810 if (!blk) { 811 error_reportf_err(local_err, "Failed to blk_new_open '%s': ", 812 argv[optind]); 813 exit(EXIT_FAILURE); 814 } 815 bs = blk_bs(blk); 816 817 if (sn_opts) { 818 ret = bdrv_snapshot_load_tmp(bs, 819 qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID), 820 qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME), 821 &local_err); 822 } else if (sn_id_or_name) { 823 ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name, 824 &local_err); 825 } 826 if (ret < 0) { 827 error_reportf_err(local_err, "Failed to load snapshot: "); 828 exit(EXIT_FAILURE); 829 } 830 831 bs->detect_zeroes = detect_zeroes; 832 fd_size = blk_getlength(blk); 833 if (fd_size < 0) { 834 error_report("Failed to determine the image length: %s", 835 strerror(-fd_size)); 836 exit(EXIT_FAILURE); 837 } 838 839 if (partition != -1) { 840 ret = find_partition(blk, partition, &dev_offset, &fd_size); 841 if (ret < 0) { 842 error_report("Could not find partition %d: %s", partition, 843 strerror(-ret)); 844 exit(EXIT_FAILURE); 845 } 846 } 847 848 exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed, 849 &local_err); 850 if (!exp) { 851 error_report_err(local_err); 852 exit(EXIT_FAILURE); 853 } 854 if (export_name) { 855 nbd_export_set_name(exp, export_name); 856 newproto = true; 857 } 858 859 server_ioc = qio_channel_socket_new(); 860 if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) { 861 object_unref(OBJECT(server_ioc)); 862 error_report_err(local_err); 863 return 1; 864 } 865 866 if (device) { 867 int ret; 868 869 ret = pthread_create(&client_thread, NULL, nbd_client_thread, device); 870 if (ret != 0) { 871 error_report("Failed to create client thread: %s", strerror(ret)); 872 exit(EXIT_FAILURE); 873 } 874 } else { 875 /* Shut up GCC warnings. */ 876 memset(&client_thread, 0, sizeof(client_thread)); 877 } 878 879 nbd_update_server_watch(); 880 881 /* now when the initialization is (almost) complete, chdir("/") 882 * to free any busy filesystems */ 883 if (chdir("/") < 0) { 884 error_report("Could not chdir to root directory: %s", 885 strerror(errno)); 886 exit(EXIT_FAILURE); 887 } 888 889 state = RUNNING; 890 do { 891 main_loop_wait(false); 892 if (state == TERMINATE) { 893 state = TERMINATING; 894 nbd_export_close(exp); 895 nbd_export_put(exp); 896 exp = NULL; 897 } 898 } while (state != TERMINATED); 899 900 blk_unref(blk); 901 if (sockpath) { 902 unlink(sockpath); 903 } 904 905 qemu_opts_del(sn_opts); 906 907 if (device) { 908 void *ret; 909 pthread_join(client_thread, &ret); 910 exit(ret != NULL); 911 } else { 912 exit(EXIT_SUCCESS); 913 } 914 } 915