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 <getopt.h> 21 #include <libgen.h> 22 #include <pthread.h> 23 24 #include "qapi/error.h" 25 #include "qemu/cutils.h" 26 #include "sysemu/block-backend.h" 27 #include "block/block_int.h" 28 #include "block/nbd.h" 29 #include "qemu/main-loop.h" 30 #include "qemu/option.h" 31 #include "qemu/error-report.h" 32 #include "qemu/config-file.h" 33 #include "qemu/bswap.h" 34 #include "qemu/log.h" 35 #include "qemu/systemd.h" 36 #include "block/snapshot.h" 37 #include "qapi/qmp/qdict.h" 38 #include "qapi/qmp/qstring.h" 39 #include "qom/object_interfaces.h" 40 #include "io/channel-socket.h" 41 #include "io/net-listener.h" 42 #include "crypto/init.h" 43 #include "trace/control.h" 44 #include "qemu-version.h" 45 46 #ifdef __linux__ 47 #define HAVE_NBD_DEVICE 1 48 #else 49 #define HAVE_NBD_DEVICE 0 50 #endif 51 52 #define SOCKET_PATH "/var/lock/qemu-nbd-%s" 53 #define QEMU_NBD_OPT_CACHE 256 54 #define QEMU_NBD_OPT_AIO 257 55 #define QEMU_NBD_OPT_DISCARD 258 56 #define QEMU_NBD_OPT_DETECT_ZEROES 259 57 #define QEMU_NBD_OPT_OBJECT 260 58 #define QEMU_NBD_OPT_TLSCREDS 261 59 #define QEMU_NBD_OPT_IMAGE_OPTS 262 60 #define QEMU_NBD_OPT_FORK 263 61 62 #define MBR_SIZE 512 63 64 static NBDExport *exp; 65 static int verbose; 66 static char *srcpath; 67 static SocketAddress *saddr; 68 static int persistent = 0; 69 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state; 70 static int shared = 1; 71 static int nb_fds; 72 static QIONetListener *server; 73 static QCryptoTLSCreds *tlscreds; 74 75 static void usage(const char *name) 76 { 77 (printf) ( 78 "Usage: %s [OPTIONS] FILE\n" 79 "QEMU Disk Network Block Device Server\n" 80 "\n" 81 " -h, --help display this help and exit\n" 82 " -V, --version output version information and exit\n" 83 "\n" 84 "Connection properties:\n" 85 " -p, --port=PORT port to listen on (default `%d')\n" 86 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n" 87 " -k, --socket=PATH path to the unix socket\n" 88 " (default '"SOCKET_PATH"')\n" 89 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n" 90 " -t, --persistent don't exit on the last connection\n" 91 " -v, --verbose display extra debugging information\n" 92 " -x, --export-name=NAME expose export by name (default is empty string)\n" 93 " -D, --description=TEXT export a human-readable description\n" 94 "\n" 95 "Exposing part of the image:\n" 96 " -o, --offset=OFFSET offset into the image\n" 97 " -P, --partition=NUM only expose partition NUM\n" 98 "\n" 99 "General purpose options:\n" 100 " --object type,id=ID,... define an object such as 'secret' for providing\n" 101 " passwords and/or encryption keys\n" 102 " --tls-creds=ID use id of an earlier --object to provide TLS\n" 103 " -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 104 " specify tracing options\n" 105 " --fork fork off the server process and exit the parent\n" 106 " once the server is running\n" 107 #if HAVE_NBD_DEVICE 108 "\n" 109 "Kernel NBD client support:\n" 110 " -c, --connect=DEV connect FILE to the local NBD device DEV\n" 111 " -d, --disconnect disconnect the specified device\n" 112 #endif 113 "\n" 114 "Block device options:\n" 115 " -f, --format=FORMAT set image format (raw, qcow2, ...)\n" 116 " -r, --read-only export read-only\n" 117 " -s, --snapshot use FILE as an external snapshot, create a temporary\n" 118 " file with backing_file=FILE, redirect the write to\n" 119 " the temporary one\n" 120 " -l, --load-snapshot=SNAPSHOT_PARAM\n" 121 " load an internal snapshot inside FILE and export it\n" 122 " as an read-only device, SNAPSHOT_PARAM format is\n" 123 " 'snapshot.id=[ID],snapshot.name=[NAME]', or\n" 124 " '[ID_OR_NAME]'\n" 125 " -n, --nocache disable host cache\n" 126 " --cache=MODE set cache mode (none, writeback, ...)\n" 127 " --aio=MODE set AIO mode (native or threads)\n" 128 " --discard=MODE set discard mode (ignore, unmap)\n" 129 " --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n" 130 " --image-opts treat FILE as a full set of image options\n" 131 "\n" 132 QEMU_HELP_BOTTOM "\n" 133 , name, NBD_DEFAULT_PORT, "DEVICE"); 134 } 135 136 static void version(const char *name) 137 { 138 printf( 139 "%s " QEMU_FULL_VERSION "\n" 140 "Written by Anthony Liguori.\n" 141 "\n" 142 QEMU_COPYRIGHT "\n" 143 "This is free software; see the source for copying conditions. There is NO\n" 144 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" 145 , name); 146 } 147 148 struct partition_record 149 { 150 uint8_t bootable; 151 uint8_t start_head; 152 uint32_t start_cylinder; 153 uint8_t start_sector; 154 uint8_t system; 155 uint8_t end_head; 156 uint8_t end_cylinder; 157 uint8_t end_sector; 158 uint32_t start_sector_abs; 159 uint32_t nb_sectors_abs; 160 }; 161 162 static void read_partition(uint8_t *p, struct partition_record *r) 163 { 164 r->bootable = p[0]; 165 r->start_head = p[1]; 166 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); 167 r->start_sector = p[2] & 0x3f; 168 r->system = p[4]; 169 r->end_head = p[5]; 170 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); 171 r->end_sector = p[6] & 0x3f; 172 173 r->start_sector_abs = ldl_le_p(p + 8); 174 r->nb_sectors_abs = ldl_le_p(p + 12); 175 } 176 177 static int find_partition(BlockBackend *blk, int partition, 178 off_t *offset, off_t *size) 179 { 180 struct partition_record mbr[4]; 181 uint8_t data[MBR_SIZE]; 182 int i; 183 int ext_partnum = 4; 184 int ret; 185 186 ret = blk_pread(blk, 0, data, sizeof(data)); 187 if (ret < 0) { 188 error_report("error while reading: %s", strerror(-ret)); 189 exit(EXIT_FAILURE); 190 } 191 192 if (data[510] != 0x55 || data[511] != 0xaa) { 193 return -EINVAL; 194 } 195 196 for (i = 0; i < 4; i++) { 197 read_partition(&data[446 + 16 * i], &mbr[i]); 198 199 if (!mbr[i].system || !mbr[i].nb_sectors_abs) { 200 continue; 201 } 202 203 if (mbr[i].system == 0xF || mbr[i].system == 0x5) { 204 struct partition_record ext[4]; 205 uint8_t data1[MBR_SIZE]; 206 int j; 207 208 ret = blk_pread(blk, mbr[i].start_sector_abs * MBR_SIZE, 209 data1, sizeof(data1)); 210 if (ret < 0) { 211 error_report("error while reading: %s", strerror(-ret)); 212 exit(EXIT_FAILURE); 213 } 214 215 for (j = 0; j < 4; j++) { 216 read_partition(&data1[446 + 16 * j], &ext[j]); 217 if (!ext[j].system || !ext[j].nb_sectors_abs) { 218 continue; 219 } 220 221 if ((ext_partnum + j + 1) == partition) { 222 *offset = (uint64_t)ext[j].start_sector_abs << 9; 223 *size = (uint64_t)ext[j].nb_sectors_abs << 9; 224 return 0; 225 } 226 } 227 ext_partnum += 4; 228 } else if ((i + 1) == partition) { 229 *offset = (uint64_t)mbr[i].start_sector_abs << 9; 230 *size = (uint64_t)mbr[i].nb_sectors_abs << 9; 231 return 0; 232 } 233 } 234 235 return -ENOENT; 236 } 237 238 static void termsig_handler(int signum) 239 { 240 atomic_cmpxchg(&state, RUNNING, TERMINATE); 241 qemu_notify_event(); 242 } 243 244 245 #if HAVE_NBD_DEVICE 246 static void *show_parts(void *arg) 247 { 248 char *device = arg; 249 int nbd; 250 251 /* linux just needs an open() to trigger 252 * the partition table update 253 * but remember to load the module with max_part != 0 : 254 * modprobe nbd max_part=63 255 */ 256 nbd = open(device, O_RDWR); 257 if (nbd >= 0) { 258 close(nbd); 259 } 260 return NULL; 261 } 262 263 static void *nbd_client_thread(void *arg) 264 { 265 char *device = arg; 266 NBDExportInfo info = { .request_sizes = false, }; 267 QIOChannelSocket *sioc; 268 int fd; 269 int ret; 270 pthread_t show_parts_thread; 271 Error *local_error = NULL; 272 273 sioc = qio_channel_socket_new(); 274 if (qio_channel_socket_connect_sync(sioc, 275 saddr, 276 &local_error) < 0) { 277 error_report_err(local_error); 278 goto out; 279 } 280 281 ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, 282 NULL, NULL, NULL, &info, &local_error); 283 if (ret < 0) { 284 if (local_error) { 285 error_report_err(local_error); 286 } 287 goto out_socket; 288 } 289 290 fd = open(device, O_RDWR); 291 if (fd < 0) { 292 /* Linux-only, we can use %m in printf. */ 293 error_report("Failed to open %s: %m", device); 294 goto out_socket; 295 } 296 297 ret = nbd_init(fd, sioc, &info, &local_error); 298 if (ret < 0) { 299 error_report_err(local_error); 300 goto out_fd; 301 } 302 303 /* update partition table */ 304 pthread_create(&show_parts_thread, NULL, show_parts, device); 305 306 if (verbose) { 307 fprintf(stderr, "NBD device %s is now connected to %s\n", 308 device, srcpath); 309 } else { 310 /* Close stderr so that the qemu-nbd process exits. */ 311 dup2(STDOUT_FILENO, STDERR_FILENO); 312 } 313 314 ret = nbd_client(fd); 315 if (ret) { 316 goto out_fd; 317 } 318 close(fd); 319 object_unref(OBJECT(sioc)); 320 kill(getpid(), SIGTERM); 321 return (void *) EXIT_SUCCESS; 322 323 out_fd: 324 close(fd); 325 out_socket: 326 object_unref(OBJECT(sioc)); 327 out: 328 kill(getpid(), SIGTERM); 329 return (void *) EXIT_FAILURE; 330 } 331 #endif /* HAVE_NBD_DEVICE */ 332 333 static int nbd_can_accept(void) 334 { 335 return state == RUNNING && nb_fds < shared; 336 } 337 338 static void nbd_export_closed(NBDExport *exp) 339 { 340 assert(state == TERMINATING); 341 state = TERMINATED; 342 } 343 344 static void nbd_update_server_watch(void); 345 346 static void nbd_client_closed(NBDClient *client, bool negotiated) 347 { 348 nb_fds--; 349 if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) { 350 state = TERMINATE; 351 } 352 nbd_update_server_watch(); 353 nbd_client_put(client); 354 } 355 356 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc, 357 gpointer opaque) 358 { 359 if (state >= TERMINATE) { 360 return; 361 } 362 363 nb_fds++; 364 nbd_update_server_watch(); 365 nbd_client_new(cioc, tlscreds, NULL, nbd_client_closed); 366 } 367 368 static void nbd_update_server_watch(void) 369 { 370 if (nbd_can_accept()) { 371 qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL); 372 } else { 373 qio_net_listener_set_client_func(server, NULL, NULL, NULL); 374 } 375 } 376 377 378 static SocketAddress *nbd_build_socket_address(const char *sockpath, 379 const char *bindto, 380 const char *port) 381 { 382 SocketAddress *saddr; 383 384 saddr = g_new0(SocketAddress, 1); 385 if (sockpath) { 386 saddr->type = SOCKET_ADDRESS_TYPE_UNIX; 387 saddr->u.q_unix.path = g_strdup(sockpath); 388 } else { 389 InetSocketAddress *inet; 390 saddr->type = SOCKET_ADDRESS_TYPE_INET; 391 inet = &saddr->u.inet; 392 inet->host = g_strdup(bindto); 393 if (port) { 394 inet->port = g_strdup(port); 395 } else { 396 inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT); 397 } 398 } 399 400 return saddr; 401 } 402 403 404 static QemuOptsList file_opts = { 405 .name = "file", 406 .implied_opt_name = "file", 407 .head = QTAILQ_HEAD_INITIALIZER(file_opts.head), 408 .desc = { 409 /* no elements => accept any params */ 410 { /* end of list */ } 411 }, 412 }; 413 414 static QemuOptsList qemu_object_opts = { 415 .name = "object", 416 .implied_opt_name = "qom-type", 417 .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head), 418 .desc = { 419 { } 420 }, 421 }; 422 423 424 425 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 426 { 427 Object *obj; 428 QCryptoTLSCreds *creds; 429 430 obj = object_resolve_path_component( 431 object_get_objects_root(), id); 432 if (!obj) { 433 error_setg(errp, "No TLS credentials with id '%s'", 434 id); 435 return NULL; 436 } 437 creds = (QCryptoTLSCreds *) 438 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 439 if (!creds) { 440 error_setg(errp, "Object with id '%s' is not TLS credentials", 441 id); 442 return NULL; 443 } 444 445 if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) { 446 error_setg(errp, 447 "Expecting TLS credentials with a server endpoint"); 448 return NULL; 449 } 450 object_ref(obj); 451 return creds; 452 } 453 454 static void setup_address_and_port(const char **address, const char **port) 455 { 456 if (*address == NULL) { 457 *address = "0.0.0.0"; 458 } 459 460 if (*port == NULL) { 461 *port = stringify(NBD_DEFAULT_PORT); 462 } 463 } 464 465 /* 466 * Check socket parameters compatibility when socket activation is used. 467 */ 468 static const char *socket_activation_validate_opts(const char *device, 469 const char *sockpath, 470 const char *address, 471 const char *port) 472 { 473 if (device != NULL) { 474 return "NBD device can't be set when using socket activation"; 475 } 476 477 if (sockpath != NULL) { 478 return "Unix socket can't be set when using socket activation"; 479 } 480 481 if (address != NULL) { 482 return "The interface can't be set when using socket activation"; 483 } 484 485 if (port != NULL) { 486 return "TCP port number can't be set when using socket activation"; 487 } 488 489 return NULL; 490 } 491 492 static void qemu_nbd_shutdown(void) 493 { 494 job_cancel_sync_all(); 495 bdrv_close_all(); 496 } 497 498 int main(int argc, char **argv) 499 { 500 BlockBackend *blk; 501 BlockDriverState *bs; 502 off_t dev_offset = 0; 503 uint16_t nbdflags = 0; 504 bool disconnect = false; 505 const char *bindto = NULL; 506 const char *port = NULL; 507 char *sockpath = NULL; 508 char *device = NULL; 509 off_t fd_size; 510 QemuOpts *sn_opts = NULL; 511 const char *sn_id_or_name = NULL; 512 const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:"; 513 struct option lopt[] = { 514 { "help", no_argument, NULL, 'h' }, 515 { "version", no_argument, NULL, 'V' }, 516 { "bind", required_argument, NULL, 'b' }, 517 { "port", required_argument, NULL, 'p' }, 518 { "socket", required_argument, NULL, 'k' }, 519 { "offset", required_argument, NULL, 'o' }, 520 { "read-only", no_argument, NULL, 'r' }, 521 { "partition", required_argument, NULL, 'P' }, 522 { "connect", required_argument, NULL, 'c' }, 523 { "disconnect", no_argument, NULL, 'd' }, 524 { "snapshot", no_argument, NULL, 's' }, 525 { "load-snapshot", required_argument, NULL, 'l' }, 526 { "nocache", no_argument, NULL, 'n' }, 527 { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE }, 528 { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO }, 529 { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD }, 530 { "detect-zeroes", required_argument, NULL, 531 QEMU_NBD_OPT_DETECT_ZEROES }, 532 { "shared", required_argument, NULL, 'e' }, 533 { "format", required_argument, NULL, 'f' }, 534 { "persistent", no_argument, NULL, 't' }, 535 { "verbose", no_argument, NULL, 'v' }, 536 { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT }, 537 { "export-name", required_argument, NULL, 'x' }, 538 { "description", required_argument, NULL, 'D' }, 539 { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS }, 540 { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS }, 541 { "trace", required_argument, NULL, 'T' }, 542 { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK }, 543 { NULL, 0, NULL, 0 } 544 }; 545 int ch; 546 int opt_ind = 0; 547 char *end; 548 int flags = BDRV_O_RDWR; 549 int partition = -1; 550 int ret = 0; 551 bool seen_cache = false; 552 bool seen_discard = false; 553 bool seen_aio = false; 554 pthread_t client_thread; 555 const char *fmt = NULL; 556 Error *local_err = NULL; 557 BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF; 558 QDict *options = NULL; 559 const char *export_name = ""; /* Default export name */ 560 const char *export_description = NULL; 561 const char *tlscredsid = NULL; 562 bool imageOpts = false; 563 bool writethrough = true; 564 char *trace_file = NULL; 565 bool fork_process = false; 566 int old_stderr = -1; 567 unsigned socket_activation; 568 569 /* The client thread uses SIGTERM to interrupt the server. A signal 570 * handler ensures that "qemu-nbd -v -c" exits with a nice status code. 571 */ 572 struct sigaction sa_sigterm; 573 memset(&sa_sigterm, 0, sizeof(sa_sigterm)); 574 sa_sigterm.sa_handler = termsig_handler; 575 sigaction(SIGTERM, &sa_sigterm, NULL); 576 577 #ifdef CONFIG_POSIX 578 signal(SIGPIPE, SIG_IGN); 579 #endif 580 581 module_call_init(MODULE_INIT_TRACE); 582 error_set_progname(argv[0]); 583 qcrypto_init(&error_fatal); 584 585 module_call_init(MODULE_INIT_QOM); 586 qemu_add_opts(&qemu_object_opts); 587 qemu_add_opts(&qemu_trace_opts); 588 qemu_init_exec_dir(argv[0]); 589 590 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { 591 switch (ch) { 592 case 's': 593 flags |= BDRV_O_SNAPSHOT; 594 break; 595 case 'n': 596 optarg = (char *) "none"; 597 /* fallthrough */ 598 case QEMU_NBD_OPT_CACHE: 599 if (seen_cache) { 600 error_report("-n and --cache can only be specified once"); 601 exit(EXIT_FAILURE); 602 } 603 seen_cache = true; 604 if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) { 605 error_report("Invalid cache mode `%s'", optarg); 606 exit(EXIT_FAILURE); 607 } 608 break; 609 case QEMU_NBD_OPT_AIO: 610 if (seen_aio) { 611 error_report("--aio can only be specified once"); 612 exit(EXIT_FAILURE); 613 } 614 seen_aio = true; 615 if (!strcmp(optarg, "native")) { 616 flags |= BDRV_O_NATIVE_AIO; 617 } else if (!strcmp(optarg, "threads")) { 618 /* this is the default */ 619 } else { 620 error_report("invalid aio mode `%s'", optarg); 621 exit(EXIT_FAILURE); 622 } 623 break; 624 case QEMU_NBD_OPT_DISCARD: 625 if (seen_discard) { 626 error_report("--discard can only be specified once"); 627 exit(EXIT_FAILURE); 628 } 629 seen_discard = true; 630 if (bdrv_parse_discard_flags(optarg, &flags) == -1) { 631 error_report("Invalid discard mode `%s'", optarg); 632 exit(EXIT_FAILURE); 633 } 634 break; 635 case QEMU_NBD_OPT_DETECT_ZEROES: 636 detect_zeroes = 637 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, 638 optarg, 639 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, 640 &local_err); 641 if (local_err) { 642 error_reportf_err(local_err, 643 "Failed to parse detect_zeroes mode: "); 644 exit(EXIT_FAILURE); 645 } 646 if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP && 647 !(flags & BDRV_O_UNMAP)) { 648 error_report("setting detect-zeroes to unmap is not allowed " 649 "without setting discard operation to unmap"); 650 exit(EXIT_FAILURE); 651 } 652 break; 653 case 'b': 654 bindto = optarg; 655 break; 656 case 'p': 657 port = optarg; 658 break; 659 case 'o': 660 dev_offset = strtoll (optarg, &end, 0); 661 if (*end) { 662 error_report("Invalid offset `%s'", optarg); 663 exit(EXIT_FAILURE); 664 } 665 if (dev_offset < 0) { 666 error_report("Offset must be positive `%s'", optarg); 667 exit(EXIT_FAILURE); 668 } 669 break; 670 case 'l': 671 if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) { 672 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts, 673 optarg, false); 674 if (!sn_opts) { 675 error_report("Failed in parsing snapshot param `%s'", 676 optarg); 677 exit(EXIT_FAILURE); 678 } 679 } else { 680 sn_id_or_name = optarg; 681 } 682 /* fall through */ 683 case 'r': 684 nbdflags |= NBD_FLAG_READ_ONLY; 685 flags &= ~BDRV_O_RDWR; 686 break; 687 case 'P': 688 partition = strtol(optarg, &end, 0); 689 if (*end) { 690 error_report("Invalid partition `%s'", optarg); 691 exit(EXIT_FAILURE); 692 } 693 if (partition < 1 || partition > 8) { 694 error_report("Invalid partition %d", partition); 695 exit(EXIT_FAILURE); 696 } 697 break; 698 case 'k': 699 sockpath = optarg; 700 if (sockpath[0] != '/') { 701 error_report("socket path must be absolute"); 702 exit(EXIT_FAILURE); 703 } 704 break; 705 case 'd': 706 disconnect = true; 707 break; 708 case 'c': 709 device = optarg; 710 break; 711 case 'e': 712 shared = strtol(optarg, &end, 0); 713 if (*end) { 714 error_report("Invalid shared device number '%s'", optarg); 715 exit(EXIT_FAILURE); 716 } 717 if (shared < 1) { 718 error_report("Shared device number must be greater than 0"); 719 exit(EXIT_FAILURE); 720 } 721 break; 722 case 'f': 723 fmt = optarg; 724 break; 725 case 't': 726 persistent = 1; 727 break; 728 case 'x': 729 export_name = optarg; 730 break; 731 case 'D': 732 export_description = optarg; 733 break; 734 case 'v': 735 verbose = 1; 736 break; 737 case 'V': 738 version(argv[0]); 739 exit(0); 740 break; 741 case 'h': 742 usage(argv[0]); 743 exit(0); 744 break; 745 case '?': 746 error_report("Try `%s --help' for more information.", argv[0]); 747 exit(EXIT_FAILURE); 748 case QEMU_NBD_OPT_OBJECT: { 749 QemuOpts *opts; 750 opts = qemu_opts_parse_noisily(&qemu_object_opts, 751 optarg, true); 752 if (!opts) { 753 exit(EXIT_FAILURE); 754 } 755 } break; 756 case QEMU_NBD_OPT_TLSCREDS: 757 tlscredsid = optarg; 758 break; 759 case QEMU_NBD_OPT_IMAGE_OPTS: 760 imageOpts = true; 761 break; 762 case 'T': 763 g_free(trace_file); 764 trace_file = trace_opt_parse(optarg); 765 break; 766 case QEMU_NBD_OPT_FORK: 767 fork_process = true; 768 break; 769 } 770 } 771 772 if ((argc - optind) != 1) { 773 error_report("Invalid number of arguments"); 774 error_printf("Try `%s --help' for more information.\n", argv[0]); 775 exit(EXIT_FAILURE); 776 } 777 778 qemu_opts_foreach(&qemu_object_opts, 779 user_creatable_add_opts_foreach, 780 NULL, &error_fatal); 781 782 if (!trace_init_backends()) { 783 exit(1); 784 } 785 trace_init_file(trace_file); 786 qemu_set_log(LOG_TRACE); 787 788 socket_activation = check_socket_activation(); 789 if (socket_activation == 0) { 790 setup_address_and_port(&bindto, &port); 791 } else { 792 /* Using socket activation - check user didn't use -p etc. */ 793 const char *err_msg = socket_activation_validate_opts(device, sockpath, 794 bindto, port); 795 if (err_msg != NULL) { 796 error_report("%s", err_msg); 797 exit(EXIT_FAILURE); 798 } 799 800 /* qemu-nbd can only listen on a single socket. */ 801 if (socket_activation > 1) { 802 error_report("qemu-nbd does not support socket activation with %s > 1", 803 "LISTEN_FDS"); 804 exit(EXIT_FAILURE); 805 } 806 } 807 808 if (tlscredsid) { 809 if (sockpath) { 810 error_report("TLS is only supported with IPv4/IPv6"); 811 exit(EXIT_FAILURE); 812 } 813 if (device) { 814 error_report("TLS is not supported with a host device"); 815 exit(EXIT_FAILURE); 816 } 817 tlscreds = nbd_get_tls_creds(tlscredsid, &local_err); 818 if (local_err) { 819 error_report("Failed to get TLS creds %s", 820 error_get_pretty(local_err)); 821 exit(EXIT_FAILURE); 822 } 823 } 824 825 #if !HAVE_NBD_DEVICE 826 if (disconnect || device) { 827 error_report("Kernel /dev/nbdN support not available"); 828 exit(EXIT_FAILURE); 829 } 830 #else /* HAVE_NBD_DEVICE */ 831 if (disconnect) { 832 int nbdfd = open(argv[optind], O_RDWR); 833 if (nbdfd < 0) { 834 error_report("Cannot open %s: %s", argv[optind], 835 strerror(errno)); 836 exit(EXIT_FAILURE); 837 } 838 nbd_disconnect(nbdfd); 839 840 close(nbdfd); 841 842 printf("%s disconnected\n", argv[optind]); 843 844 return 0; 845 } 846 #endif 847 848 if ((device && !verbose) || fork_process) { 849 int stderr_fd[2]; 850 pid_t pid; 851 int ret; 852 853 if (qemu_pipe(stderr_fd) < 0) { 854 error_report("Error setting up communication pipe: %s", 855 strerror(errno)); 856 exit(EXIT_FAILURE); 857 } 858 859 /* Now daemonize, but keep a communication channel open to 860 * print errors and exit with the proper status code. 861 */ 862 pid = fork(); 863 if (pid < 0) { 864 error_report("Failed to fork: %s", strerror(errno)); 865 exit(EXIT_FAILURE); 866 } else if (pid == 0) { 867 close(stderr_fd[0]); 868 ret = qemu_daemon(1, 0); 869 870 /* Temporarily redirect stderr to the parent's pipe... */ 871 old_stderr = dup(STDERR_FILENO); 872 dup2(stderr_fd[1], STDERR_FILENO); 873 if (ret < 0) { 874 error_report("Failed to daemonize: %s", strerror(errno)); 875 exit(EXIT_FAILURE); 876 } 877 878 /* ... close the descriptor we inherited and go on. */ 879 close(stderr_fd[1]); 880 } else { 881 bool errors = false; 882 char *buf; 883 884 /* In the parent. Print error messages from the child until 885 * it closes the pipe. 886 */ 887 close(stderr_fd[1]); 888 buf = g_malloc(1024); 889 while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { 890 errors = true; 891 ret = qemu_write_full(STDERR_FILENO, buf, ret); 892 if (ret < 0) { 893 exit(EXIT_FAILURE); 894 } 895 } 896 if (ret < 0) { 897 error_report("Cannot read from daemon: %s", 898 strerror(errno)); 899 exit(EXIT_FAILURE); 900 } 901 902 /* Usually the daemon should not print any message. 903 * Exit with zero status in that case. 904 */ 905 exit(errors); 906 } 907 } 908 909 if (device != NULL && sockpath == NULL) { 910 sockpath = g_malloc(128); 911 snprintf(sockpath, 128, SOCKET_PATH, basename(device)); 912 } 913 914 server = qio_net_listener_new(); 915 if (socket_activation == 0) { 916 saddr = nbd_build_socket_address(sockpath, bindto, port); 917 if (qio_net_listener_open_sync(server, saddr, &local_err) < 0) { 918 object_unref(OBJECT(server)); 919 error_report_err(local_err); 920 exit(EXIT_FAILURE); 921 } 922 } else { 923 size_t i; 924 /* See comment in check_socket_activation above. */ 925 for (i = 0; i < socket_activation; i++) { 926 QIOChannelSocket *sioc; 927 sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i, 928 &local_err); 929 if (sioc == NULL) { 930 object_unref(OBJECT(server)); 931 error_report("Failed to use socket activation: %s", 932 error_get_pretty(local_err)); 933 exit(EXIT_FAILURE); 934 } 935 qio_net_listener_add(server, sioc); 936 object_unref(OBJECT(sioc)); 937 } 938 } 939 940 if (qemu_init_main_loop(&local_err)) { 941 error_report_err(local_err); 942 exit(EXIT_FAILURE); 943 } 944 bdrv_init(); 945 atexit(qemu_nbd_shutdown); 946 947 srcpath = argv[optind]; 948 if (imageOpts) { 949 QemuOpts *opts; 950 if (fmt) { 951 error_report("--image-opts and -f are mutually exclusive"); 952 exit(EXIT_FAILURE); 953 } 954 opts = qemu_opts_parse_noisily(&file_opts, srcpath, true); 955 if (!opts) { 956 qemu_opts_reset(&file_opts); 957 exit(EXIT_FAILURE); 958 } 959 options = qemu_opts_to_qdict(opts, NULL); 960 qemu_opts_reset(&file_opts); 961 blk = blk_new_open(NULL, NULL, options, flags, &local_err); 962 } else { 963 if (fmt) { 964 options = qdict_new(); 965 qdict_put_str(options, "driver", fmt); 966 } 967 blk = blk_new_open(srcpath, NULL, options, flags, &local_err); 968 } 969 970 if (!blk) { 971 error_reportf_err(local_err, "Failed to blk_new_open '%s': ", 972 argv[optind]); 973 exit(EXIT_FAILURE); 974 } 975 bs = blk_bs(blk); 976 977 blk_set_enable_write_cache(blk, !writethrough); 978 979 if (sn_opts) { 980 ret = bdrv_snapshot_load_tmp(bs, 981 qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID), 982 qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME), 983 &local_err); 984 } else if (sn_id_or_name) { 985 ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name, 986 &local_err); 987 } 988 if (ret < 0) { 989 error_reportf_err(local_err, "Failed to load snapshot: "); 990 exit(EXIT_FAILURE); 991 } 992 993 bs->detect_zeroes = detect_zeroes; 994 fd_size = blk_getlength(blk); 995 if (fd_size < 0) { 996 error_report("Failed to determine the image length: %s", 997 strerror(-fd_size)); 998 exit(EXIT_FAILURE); 999 } 1000 1001 if (dev_offset >= fd_size) { 1002 error_report("Offset (%lld) has to be smaller than the image size " 1003 "(%lld)", 1004 (long long int)dev_offset, (long long int)fd_size); 1005 exit(EXIT_FAILURE); 1006 } 1007 fd_size -= dev_offset; 1008 1009 if (partition != -1) { 1010 ret = find_partition(blk, partition, &dev_offset, &fd_size); 1011 if (ret < 0) { 1012 error_report("Could not find partition %d: %s", partition, 1013 strerror(-ret)); 1014 exit(EXIT_FAILURE); 1015 } 1016 } 1017 1018 exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags, nbd_export_closed, 1019 writethrough, NULL, &error_fatal); 1020 nbd_export_set_name(exp, export_name); 1021 nbd_export_set_description(exp, export_description); 1022 1023 if (device) { 1024 #if HAVE_NBD_DEVICE 1025 int ret; 1026 1027 ret = pthread_create(&client_thread, NULL, nbd_client_thread, device); 1028 if (ret != 0) { 1029 error_report("Failed to create client thread: %s", strerror(ret)); 1030 exit(EXIT_FAILURE); 1031 } 1032 #endif 1033 } else { 1034 /* Shut up GCC warnings. */ 1035 memset(&client_thread, 0, sizeof(client_thread)); 1036 } 1037 1038 nbd_update_server_watch(); 1039 1040 /* now when the initialization is (almost) complete, chdir("/") 1041 * to free any busy filesystems */ 1042 if (chdir("/") < 0) { 1043 error_report("Could not chdir to root directory: %s", 1044 strerror(errno)); 1045 exit(EXIT_FAILURE); 1046 } 1047 1048 if (fork_process) { 1049 dup2(old_stderr, STDERR_FILENO); 1050 close(old_stderr); 1051 } 1052 1053 state = RUNNING; 1054 do { 1055 main_loop_wait(false); 1056 if (state == TERMINATE) { 1057 state = TERMINATING; 1058 nbd_export_close(exp); 1059 nbd_export_put(exp); 1060 exp = NULL; 1061 } 1062 } while (state != TERMINATED); 1063 1064 blk_unref(blk); 1065 if (sockpath) { 1066 unlink(sockpath); 1067 } 1068 1069 qemu_opts_del(sn_opts); 1070 1071 if (device) { 1072 void *ret; 1073 pthread_join(client_thread, &ret); 1074 exit(ret != NULL); 1075 } else { 1076 exit(EXIT_SUCCESS); 1077 } 1078 } 1079