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 "qapi/error.h" 21 #include "qemu-common.h" 22 #include "qemu/cutils.h" 23 #include "sysemu/block-backend.h" 24 #include "block/block_int.h" 25 #include "block/nbd.h" 26 #include "qemu/main-loop.h" 27 #include "qemu/error-report.h" 28 #include "qemu/config-file.h" 29 #include "qemu/bswap.h" 30 #include "qemu/log.h" 31 #include "qemu/systemd.h" 32 #include "block/snapshot.h" 33 #include "qapi/util.h" 34 #include "qapi/qmp/qstring.h" 35 #include "qom/object_interfaces.h" 36 #include "io/channel-socket.h" 37 #include "crypto/init.h" 38 #include "trace/control.h" 39 40 #include <getopt.h> 41 #include <libgen.h> 42 #include <pthread.h> 43 44 #define SOCKET_PATH "/var/lock/qemu-nbd-%s" 45 #define QEMU_NBD_OPT_CACHE 256 46 #define QEMU_NBD_OPT_AIO 257 47 #define QEMU_NBD_OPT_DISCARD 258 48 #define QEMU_NBD_OPT_DETECT_ZEROES 259 49 #define QEMU_NBD_OPT_OBJECT 260 50 #define QEMU_NBD_OPT_TLSCREDS 261 51 #define QEMU_NBD_OPT_IMAGE_OPTS 262 52 #define QEMU_NBD_OPT_FORK 263 53 54 #define MBR_SIZE 512 55 56 static NBDExport *exp; 57 static bool newproto; 58 static int verbose; 59 static char *srcpath; 60 static SocketAddress *saddr; 61 static int persistent = 0; 62 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state; 63 static int shared = 1; 64 static int nb_fds; 65 static QIOChannelSocket *server_ioc; 66 static int server_watch = -1; 67 static QCryptoTLSCreds *tlscreds; 68 69 static void usage(const char *name) 70 { 71 (printf) ( 72 "Usage: %s [OPTIONS] FILE\n" 73 "QEMU Disk Network Block Device Server\n" 74 "\n" 75 " -h, --help display this help and exit\n" 76 " -V, --version output version information and exit\n" 77 "\n" 78 "Connection properties:\n" 79 " -p, --port=PORT port to listen on (default `%d')\n" 80 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n" 81 " -k, --socket=PATH path to the unix socket\n" 82 " (default '"SOCKET_PATH"')\n" 83 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n" 84 " -t, --persistent don't exit on the last connection\n" 85 " -v, --verbose display extra debugging information\n" 86 " -x, --export-name=NAME expose export by name\n" 87 " -D, --description=TEXT with -x, also export a human-readable description\n" 88 "\n" 89 "Exposing part of the image:\n" 90 " -o, --offset=OFFSET offset into the image\n" 91 " -P, --partition=NUM only expose partition NUM\n" 92 "\n" 93 "General purpose options:\n" 94 " --object type,id=ID,... define an object such as 'secret' for providing\n" 95 " passwords and/or encryption keys\n" 96 " -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 97 " specify tracing options\n" 98 " --fork fork off the server process and exit the parent\n" 99 " once the server is running\n" 100 #ifdef __linux__ 101 "Kernel NBD client support:\n" 102 " -c, --connect=DEV connect FILE to the local NBD device DEV\n" 103 " -d, --disconnect disconnect the specified device\n" 104 "\n" 105 #endif 106 "\n" 107 "Block device options:\n" 108 " -f, --format=FORMAT set image format (raw, qcow2, ...)\n" 109 " -r, --read-only export read-only\n" 110 " -s, --snapshot use FILE as an external snapshot, create a temporary\n" 111 " file with backing_file=FILE, redirect the write to\n" 112 " the temporary one\n" 113 " -l, --load-snapshot=SNAPSHOT_PARAM\n" 114 " load an internal snapshot inside FILE and export it\n" 115 " as an read-only device, SNAPSHOT_PARAM format is\n" 116 " 'snapshot.id=[ID],snapshot.name=[NAME]', or\n" 117 " '[ID_OR_NAME]'\n" 118 " -n, --nocache disable host cache\n" 119 " --cache=MODE set cache mode (none, writeback, ...)\n" 120 " --aio=MODE set AIO mode (native or threads)\n" 121 " --discard=MODE set discard mode (ignore, unmap)\n" 122 " --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n" 123 " --image-opts treat FILE as a full set of image options\n" 124 "\n" 125 "Report bugs to <qemu-devel@nongnu.org>\n" 126 , name, NBD_DEFAULT_PORT, "DEVICE"); 127 } 128 129 static void version(const char *name) 130 { 131 printf( 132 "%s version 0.0.1\n" 133 "Written by Anthony Liguori.\n" 134 "\n" 135 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n" 136 "This is free software; see the source for copying conditions. There is NO\n" 137 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" 138 , name); 139 } 140 141 struct partition_record 142 { 143 uint8_t bootable; 144 uint8_t start_head; 145 uint32_t start_cylinder; 146 uint8_t start_sector; 147 uint8_t system; 148 uint8_t end_head; 149 uint8_t end_cylinder; 150 uint8_t end_sector; 151 uint32_t start_sector_abs; 152 uint32_t nb_sectors_abs; 153 }; 154 155 static void read_partition(uint8_t *p, struct partition_record *r) 156 { 157 r->bootable = p[0]; 158 r->start_head = p[1]; 159 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); 160 r->start_sector = p[2] & 0x3f; 161 r->system = p[4]; 162 r->end_head = p[5]; 163 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); 164 r->end_sector = p[6] & 0x3f; 165 166 r->start_sector_abs = ldl_le_p(p + 8); 167 r->nb_sectors_abs = ldl_le_p(p + 12); 168 } 169 170 static int find_partition(BlockBackend *blk, int partition, 171 off_t *offset, off_t *size) 172 { 173 struct partition_record mbr[4]; 174 uint8_t data[MBR_SIZE]; 175 int i; 176 int ext_partnum = 4; 177 int ret; 178 179 ret = blk_pread(blk, 0, data, sizeof(data)); 180 if (ret < 0) { 181 error_report("error while reading: %s", strerror(-ret)); 182 exit(EXIT_FAILURE); 183 } 184 185 if (data[510] != 0x55 || data[511] != 0xaa) { 186 return -EINVAL; 187 } 188 189 for (i = 0; i < 4; i++) { 190 read_partition(&data[446 + 16 * i], &mbr[i]); 191 192 if (!mbr[i].system || !mbr[i].nb_sectors_abs) { 193 continue; 194 } 195 196 if (mbr[i].system == 0xF || mbr[i].system == 0x5) { 197 struct partition_record ext[4]; 198 uint8_t data1[MBR_SIZE]; 199 int j; 200 201 ret = blk_pread(blk, mbr[i].start_sector_abs * MBR_SIZE, 202 data1, sizeof(data1)); 203 if (ret < 0) { 204 error_report("error while reading: %s", strerror(-ret)); 205 exit(EXIT_FAILURE); 206 } 207 208 for (j = 0; j < 4; j++) { 209 read_partition(&data1[446 + 16 * j], &ext[j]); 210 if (!ext[j].system || !ext[j].nb_sectors_abs) { 211 continue; 212 } 213 214 if ((ext_partnum + j + 1) == partition) { 215 *offset = (uint64_t)ext[j].start_sector_abs << 9; 216 *size = (uint64_t)ext[j].nb_sectors_abs << 9; 217 return 0; 218 } 219 } 220 ext_partnum += 4; 221 } else if ((i + 1) == partition) { 222 *offset = (uint64_t)mbr[i].start_sector_abs << 9; 223 *size = (uint64_t)mbr[i].nb_sectors_abs << 9; 224 return 0; 225 } 226 } 227 228 return -ENOENT; 229 } 230 231 static void termsig_handler(int signum) 232 { 233 atomic_cmpxchg(&state, RUNNING, TERMINATE); 234 qemu_notify_event(); 235 } 236 237 238 static void *show_parts(void *arg) 239 { 240 char *device = arg; 241 int nbd; 242 243 /* linux just needs an open() to trigger 244 * the partition table update 245 * but remember to load the module with max_part != 0 : 246 * modprobe nbd max_part=63 247 */ 248 nbd = open(device, O_RDWR); 249 if (nbd >= 0) { 250 close(nbd); 251 } 252 return NULL; 253 } 254 255 static void *nbd_client_thread(void *arg) 256 { 257 char *device = arg; 258 NBDExportInfo info = { .request_sizes = false, }; 259 QIOChannelSocket *sioc; 260 int fd; 261 int ret; 262 pthread_t show_parts_thread; 263 Error *local_error = NULL; 264 265 sioc = qio_channel_socket_new(); 266 if (qio_channel_socket_connect_sync(sioc, 267 saddr, 268 &local_error) < 0) { 269 error_report_err(local_error); 270 goto out; 271 } 272 273 ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, 274 NULL, NULL, NULL, &info, &local_error); 275 if (ret < 0) { 276 if (local_error) { 277 error_report_err(local_error); 278 } 279 goto out_socket; 280 } 281 282 fd = open(device, O_RDWR); 283 if (fd < 0) { 284 /* Linux-only, we can use %m in printf. */ 285 error_report("Failed to open %s: %m", device); 286 goto out_socket; 287 } 288 289 ret = nbd_init(fd, sioc, &info, &local_error); 290 if (ret < 0) { 291 error_report_err(local_error); 292 goto out_fd; 293 } 294 295 /* update partition table */ 296 pthread_create(&show_parts_thread, NULL, show_parts, device); 297 298 if (verbose) { 299 fprintf(stderr, "NBD device %s is now connected to %s\n", 300 device, srcpath); 301 } else { 302 /* Close stderr so that the qemu-nbd process exits. */ 303 dup2(STDOUT_FILENO, STDERR_FILENO); 304 } 305 306 ret = nbd_client(fd); 307 if (ret) { 308 goto out_fd; 309 } 310 close(fd); 311 object_unref(OBJECT(sioc)); 312 kill(getpid(), SIGTERM); 313 return (void *) EXIT_SUCCESS; 314 315 out_fd: 316 close(fd); 317 out_socket: 318 object_unref(OBJECT(sioc)); 319 out: 320 kill(getpid(), SIGTERM); 321 return (void *) EXIT_FAILURE; 322 } 323 324 static int nbd_can_accept(void) 325 { 326 return state == RUNNING && nb_fds < shared; 327 } 328 329 static void nbd_export_closed(NBDExport *exp) 330 { 331 assert(state == TERMINATING); 332 state = TERMINATED; 333 } 334 335 static void nbd_update_server_watch(void); 336 337 static void nbd_client_closed(NBDClient *client, bool negotiated) 338 { 339 nb_fds--; 340 if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) { 341 state = TERMINATE; 342 } 343 nbd_update_server_watch(); 344 nbd_client_put(client); 345 } 346 347 static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque) 348 { 349 QIOChannelSocket *cioc; 350 351 cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc), 352 NULL); 353 if (!cioc) { 354 return TRUE; 355 } 356 357 if (state >= TERMINATE) { 358 object_unref(OBJECT(cioc)); 359 return TRUE; 360 } 361 362 nb_fds++; 363 nbd_update_server_watch(); 364 nbd_client_new(newproto ? NULL : exp, cioc, 365 tlscreds, NULL, nbd_client_closed); 366 object_unref(OBJECT(cioc)); 367 368 return TRUE; 369 } 370 371 static void nbd_update_server_watch(void) 372 { 373 if (nbd_can_accept()) { 374 if (server_watch == -1) { 375 server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc), 376 G_IO_IN, 377 nbd_accept, 378 NULL, NULL); 379 } 380 } else { 381 if (server_watch != -1) { 382 g_source_remove(server_watch); 383 server_watch = -1; 384 } 385 } 386 } 387 388 389 static SocketAddress *nbd_build_socket_address(const char *sockpath, 390 const char *bindto, 391 const char *port) 392 { 393 SocketAddress *saddr; 394 395 saddr = g_new0(SocketAddress, 1); 396 if (sockpath) { 397 saddr->type = SOCKET_ADDRESS_TYPE_UNIX; 398 saddr->u.q_unix.path = g_strdup(sockpath); 399 } else { 400 InetSocketAddress *inet; 401 saddr->type = SOCKET_ADDRESS_TYPE_INET; 402 inet = &saddr->u.inet; 403 inet->host = g_strdup(bindto); 404 if (port) { 405 inet->port = g_strdup(port); 406 } else { 407 inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT); 408 } 409 } 410 411 return saddr; 412 } 413 414 415 static QemuOptsList file_opts = { 416 .name = "file", 417 .implied_opt_name = "file", 418 .head = QTAILQ_HEAD_INITIALIZER(file_opts.head), 419 .desc = { 420 /* no elements => accept any params */ 421 { /* end of list */ } 422 }, 423 }; 424 425 static QemuOptsList qemu_object_opts = { 426 .name = "object", 427 .implied_opt_name = "qom-type", 428 .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head), 429 .desc = { 430 { } 431 }, 432 }; 433 434 435 436 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 437 { 438 Object *obj; 439 QCryptoTLSCreds *creds; 440 441 obj = object_resolve_path_component( 442 object_get_objects_root(), id); 443 if (!obj) { 444 error_setg(errp, "No TLS credentials with id '%s'", 445 id); 446 return NULL; 447 } 448 creds = (QCryptoTLSCreds *) 449 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 450 if (!creds) { 451 error_setg(errp, "Object with id '%s' is not TLS credentials", 452 id); 453 return NULL; 454 } 455 456 if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) { 457 error_setg(errp, 458 "Expecting TLS credentials with a server endpoint"); 459 return NULL; 460 } 461 object_ref(obj); 462 return creds; 463 } 464 465 static void setup_address_and_port(const char **address, const char **port) 466 { 467 if (*address == NULL) { 468 *address = "0.0.0.0"; 469 } 470 471 if (*port == NULL) { 472 *port = stringify(NBD_DEFAULT_PORT); 473 } 474 } 475 476 /* 477 * Check socket parameters compatibility when socket activation is used. 478 */ 479 static const char *socket_activation_validate_opts(const char *device, 480 const char *sockpath, 481 const char *address, 482 const char *port) 483 { 484 if (device != NULL) { 485 return "NBD device can't be set when using socket activation"; 486 } 487 488 if (sockpath != NULL) { 489 return "Unix socket can't be set when using socket activation"; 490 } 491 492 if (address != NULL) { 493 return "The interface can't be set when using socket activation"; 494 } 495 496 if (port != NULL) { 497 return "TCP port number can't be set when using socket activation"; 498 } 499 500 return NULL; 501 } 502 503 int main(int argc, char **argv) 504 { 505 BlockBackend *blk; 506 BlockDriverState *bs; 507 off_t dev_offset = 0; 508 uint16_t nbdflags = 0; 509 bool disconnect = false; 510 const char *bindto = NULL; 511 const char *port = NULL; 512 char *sockpath = NULL; 513 char *device = NULL; 514 off_t fd_size; 515 QemuOpts *sn_opts = NULL; 516 const char *sn_id_or_name = NULL; 517 const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:"; 518 struct option lopt[] = { 519 { "help", no_argument, NULL, 'h' }, 520 { "version", no_argument, NULL, 'V' }, 521 { "bind", required_argument, NULL, 'b' }, 522 { "port", required_argument, NULL, 'p' }, 523 { "socket", required_argument, NULL, 'k' }, 524 { "offset", required_argument, NULL, 'o' }, 525 { "read-only", no_argument, NULL, 'r' }, 526 { "partition", required_argument, NULL, 'P' }, 527 { "connect", required_argument, NULL, 'c' }, 528 { "disconnect", no_argument, NULL, 'd' }, 529 { "snapshot", no_argument, NULL, 's' }, 530 { "load-snapshot", required_argument, NULL, 'l' }, 531 { "nocache", no_argument, NULL, 'n' }, 532 { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE }, 533 { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO }, 534 { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD }, 535 { "detect-zeroes", required_argument, NULL, 536 QEMU_NBD_OPT_DETECT_ZEROES }, 537 { "shared", required_argument, NULL, 'e' }, 538 { "format", required_argument, NULL, 'f' }, 539 { "persistent", no_argument, NULL, 't' }, 540 { "verbose", no_argument, NULL, 'v' }, 541 { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT }, 542 { "export-name", required_argument, NULL, 'x' }, 543 { "description", required_argument, NULL, 'D' }, 544 { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS }, 545 { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS }, 546 { "trace", required_argument, NULL, 'T' }, 547 { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK }, 548 { NULL, 0, NULL, 0 } 549 }; 550 int ch; 551 int opt_ind = 0; 552 char *end; 553 int flags = BDRV_O_RDWR; 554 int partition = -1; 555 int ret = 0; 556 bool seen_cache = false; 557 bool seen_discard = false; 558 bool seen_aio = false; 559 pthread_t client_thread; 560 const char *fmt = NULL; 561 Error *local_err = NULL; 562 BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF; 563 QDict *options = NULL; 564 const char *export_name = NULL; 565 const char *export_description = NULL; 566 const char *tlscredsid = NULL; 567 bool imageOpts = false; 568 bool writethrough = true; 569 char *trace_file = NULL; 570 bool fork_process = false; 571 int old_stderr = -1; 572 unsigned socket_activation; 573 574 /* The client thread uses SIGTERM to interrupt the server. A signal 575 * handler ensures that "qemu-nbd -v -c" exits with a nice status code. 576 */ 577 struct sigaction sa_sigterm; 578 memset(&sa_sigterm, 0, sizeof(sa_sigterm)); 579 sa_sigterm.sa_handler = termsig_handler; 580 sigaction(SIGTERM, &sa_sigterm, NULL); 581 582 #ifdef CONFIG_POSIX 583 signal(SIGPIPE, SIG_IGN); 584 #endif 585 586 module_call_init(MODULE_INIT_TRACE); 587 qcrypto_init(&error_fatal); 588 589 module_call_init(MODULE_INIT_QOM); 590 qemu_add_opts(&qemu_object_opts); 591 qemu_add_opts(&qemu_trace_opts); 592 qemu_init_exec_dir(argv[0]); 593 594 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { 595 switch (ch) { 596 case 's': 597 flags |= BDRV_O_SNAPSHOT; 598 break; 599 case 'n': 600 optarg = (char *) "none"; 601 /* fallthrough */ 602 case QEMU_NBD_OPT_CACHE: 603 if (seen_cache) { 604 error_report("-n and --cache can only be specified once"); 605 exit(EXIT_FAILURE); 606 } 607 seen_cache = true; 608 if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) { 609 error_report("Invalid cache mode `%s'", optarg); 610 exit(EXIT_FAILURE); 611 } 612 break; 613 case QEMU_NBD_OPT_AIO: 614 if (seen_aio) { 615 error_report("--aio can only be specified once"); 616 exit(EXIT_FAILURE); 617 } 618 seen_aio = true; 619 if (!strcmp(optarg, "native")) { 620 flags |= BDRV_O_NATIVE_AIO; 621 } else if (!strcmp(optarg, "threads")) { 622 /* this is the default */ 623 } else { 624 error_report("invalid aio mode `%s'", optarg); 625 exit(EXIT_FAILURE); 626 } 627 break; 628 case QEMU_NBD_OPT_DISCARD: 629 if (seen_discard) { 630 error_report("--discard can only be specified once"); 631 exit(EXIT_FAILURE); 632 } 633 seen_discard = true; 634 if (bdrv_parse_discard_flags(optarg, &flags) == -1) { 635 error_report("Invalid discard mode `%s'", optarg); 636 exit(EXIT_FAILURE); 637 } 638 break; 639 case QEMU_NBD_OPT_DETECT_ZEROES: 640 detect_zeroes = 641 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup, 642 optarg, 643 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX, 644 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, 645 &local_err); 646 if (local_err) { 647 error_reportf_err(local_err, 648 "Failed to parse detect_zeroes mode: "); 649 exit(EXIT_FAILURE); 650 } 651 if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP && 652 !(flags & BDRV_O_UNMAP)) { 653 error_report("setting detect-zeroes to unmap is not allowed " 654 "without setting discard operation to unmap"); 655 exit(EXIT_FAILURE); 656 } 657 break; 658 case 'b': 659 bindto = optarg; 660 break; 661 case 'p': 662 port = optarg; 663 break; 664 case 'o': 665 dev_offset = strtoll (optarg, &end, 0); 666 if (*end) { 667 error_report("Invalid offset `%s'", optarg); 668 exit(EXIT_FAILURE); 669 } 670 if (dev_offset < 0) { 671 error_report("Offset must be positive `%s'", optarg); 672 exit(EXIT_FAILURE); 673 } 674 break; 675 case 'l': 676 if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) { 677 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts, 678 optarg, false); 679 if (!sn_opts) { 680 error_report("Failed in parsing snapshot param `%s'", 681 optarg); 682 exit(EXIT_FAILURE); 683 } 684 } else { 685 sn_id_or_name = optarg; 686 } 687 /* fall through */ 688 case 'r': 689 nbdflags |= NBD_FLAG_READ_ONLY; 690 flags &= ~BDRV_O_RDWR; 691 break; 692 case 'P': 693 partition = strtol(optarg, &end, 0); 694 if (*end) { 695 error_report("Invalid partition `%s'", optarg); 696 exit(EXIT_FAILURE); 697 } 698 if (partition < 1 || partition > 8) { 699 error_report("Invalid partition %d", partition); 700 exit(EXIT_FAILURE); 701 } 702 break; 703 case 'k': 704 sockpath = optarg; 705 if (sockpath[0] != '/') { 706 error_report("socket path must be absolute"); 707 exit(EXIT_FAILURE); 708 } 709 break; 710 case 'd': 711 disconnect = true; 712 break; 713 case 'c': 714 device = optarg; 715 break; 716 case 'e': 717 shared = strtol(optarg, &end, 0); 718 if (*end) { 719 error_report("Invalid shared device number '%s'", optarg); 720 exit(EXIT_FAILURE); 721 } 722 if (shared < 1) { 723 error_report("Shared device number must be greater than 0"); 724 exit(EXIT_FAILURE); 725 } 726 break; 727 case 'f': 728 fmt = optarg; 729 break; 730 case 't': 731 persistent = 1; 732 break; 733 case 'x': 734 export_name = optarg; 735 break; 736 case 'D': 737 export_description = optarg; 738 break; 739 case 'v': 740 verbose = 1; 741 break; 742 case 'V': 743 version(argv[0]); 744 exit(0); 745 break; 746 case 'h': 747 usage(argv[0]); 748 exit(0); 749 break; 750 case '?': 751 error_report("Try `%s --help' for more information.", argv[0]); 752 exit(EXIT_FAILURE); 753 case QEMU_NBD_OPT_OBJECT: { 754 QemuOpts *opts; 755 opts = qemu_opts_parse_noisily(&qemu_object_opts, 756 optarg, true); 757 if (!opts) { 758 exit(EXIT_FAILURE); 759 } 760 } break; 761 case QEMU_NBD_OPT_TLSCREDS: 762 tlscredsid = optarg; 763 break; 764 case QEMU_NBD_OPT_IMAGE_OPTS: 765 imageOpts = true; 766 break; 767 case 'T': 768 g_free(trace_file); 769 trace_file = trace_opt_parse(optarg); 770 break; 771 case QEMU_NBD_OPT_FORK: 772 fork_process = true; 773 break; 774 } 775 } 776 777 if ((argc - optind) != 1) { 778 error_report("Invalid number of arguments"); 779 error_printf("Try `%s --help' for more information.\n", argv[0]); 780 exit(EXIT_FAILURE); 781 } 782 783 if (qemu_opts_foreach(&qemu_object_opts, 784 user_creatable_add_opts_foreach, 785 NULL, NULL)) { 786 exit(EXIT_FAILURE); 787 } 788 789 if (!trace_init_backends()) { 790 exit(1); 791 } 792 trace_init_file(trace_file); 793 qemu_set_log(LOG_TRACE); 794 795 socket_activation = check_socket_activation(); 796 if (socket_activation == 0) { 797 setup_address_and_port(&bindto, &port); 798 } else { 799 /* Using socket activation - check user didn't use -p etc. */ 800 const char *err_msg = socket_activation_validate_opts(device, sockpath, 801 bindto, port); 802 if (err_msg != NULL) { 803 error_report("%s", err_msg); 804 exit(EXIT_FAILURE); 805 } 806 807 /* qemu-nbd can only listen on a single socket. */ 808 if (socket_activation > 1) { 809 error_report("qemu-nbd does not support socket activation with %s > 1", 810 "LISTEN_FDS"); 811 exit(EXIT_FAILURE); 812 } 813 } 814 815 if (tlscredsid) { 816 if (sockpath) { 817 error_report("TLS is only supported with IPv4/IPv6"); 818 exit(EXIT_FAILURE); 819 } 820 if (device) { 821 error_report("TLS is not supported with a host device"); 822 exit(EXIT_FAILURE); 823 } 824 if (!export_name) { 825 /* Set the default NBD protocol export name, since 826 * we *must* use new style protocol for TLS */ 827 export_name = ""; 828 } 829 tlscreds = nbd_get_tls_creds(tlscredsid, &local_err); 830 if (local_err) { 831 error_report("Failed to get TLS creds %s", 832 error_get_pretty(local_err)); 833 exit(EXIT_FAILURE); 834 } 835 } 836 837 if (disconnect) { 838 int nbdfd = open(argv[optind], O_RDWR); 839 if (nbdfd < 0) { 840 error_report("Cannot open %s: %s", argv[optind], 841 strerror(errno)); 842 exit(EXIT_FAILURE); 843 } 844 nbd_disconnect(nbdfd); 845 846 close(nbdfd); 847 848 printf("%s disconnected\n", argv[optind]); 849 850 return 0; 851 } 852 853 if ((device && !verbose) || fork_process) { 854 int stderr_fd[2]; 855 pid_t pid; 856 int ret; 857 858 if (qemu_pipe(stderr_fd) < 0) { 859 error_report("Error setting up communication pipe: %s", 860 strerror(errno)); 861 exit(EXIT_FAILURE); 862 } 863 864 /* Now daemonize, but keep a communication channel open to 865 * print errors and exit with the proper status code. 866 */ 867 pid = fork(); 868 if (pid < 0) { 869 error_report("Failed to fork: %s", strerror(errno)); 870 exit(EXIT_FAILURE); 871 } else if (pid == 0) { 872 close(stderr_fd[0]); 873 ret = qemu_daemon(1, 0); 874 875 /* Temporarily redirect stderr to the parent's pipe... */ 876 old_stderr = dup(STDERR_FILENO); 877 dup2(stderr_fd[1], STDERR_FILENO); 878 if (ret < 0) { 879 error_report("Failed to daemonize: %s", strerror(errno)); 880 exit(EXIT_FAILURE); 881 } 882 883 /* ... close the descriptor we inherited and go on. */ 884 close(stderr_fd[1]); 885 } else { 886 bool errors = false; 887 char *buf; 888 889 /* In the parent. Print error messages from the child until 890 * it closes the pipe. 891 */ 892 close(stderr_fd[1]); 893 buf = g_malloc(1024); 894 while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { 895 errors = true; 896 ret = qemu_write_full(STDERR_FILENO, buf, ret); 897 if (ret < 0) { 898 exit(EXIT_FAILURE); 899 } 900 } 901 if (ret < 0) { 902 error_report("Cannot read from daemon: %s", 903 strerror(errno)); 904 exit(EXIT_FAILURE); 905 } 906 907 /* Usually the daemon should not print any message. 908 * Exit with zero status in that case. 909 */ 910 exit(errors); 911 } 912 } 913 914 if (device != NULL && sockpath == NULL) { 915 sockpath = g_malloc(128); 916 snprintf(sockpath, 128, SOCKET_PATH, basename(device)); 917 } 918 919 if (socket_activation == 0) { 920 server_ioc = qio_channel_socket_new(); 921 saddr = nbd_build_socket_address(sockpath, bindto, port); 922 if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) { 923 object_unref(OBJECT(server_ioc)); 924 error_report_err(local_err); 925 return 1; 926 } 927 } else { 928 /* See comment in check_socket_activation above. */ 929 assert(socket_activation == 1); 930 server_ioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD, 931 &local_err); 932 if (server_ioc == NULL) { 933 error_report("Failed to use socket activation: %s", 934 error_get_pretty(local_err)); 935 exit(EXIT_FAILURE); 936 } 937 } 938 939 if (qemu_init_main_loop(&local_err)) { 940 error_report_err(local_err); 941 exit(EXIT_FAILURE); 942 } 943 bdrv_init(); 944 atexit(bdrv_close_all); 945 946 srcpath = argv[optind]; 947 if (imageOpts) { 948 QemuOpts *opts; 949 if (fmt) { 950 error_report("--image-opts and -f are mutually exclusive"); 951 exit(EXIT_FAILURE); 952 } 953 opts = qemu_opts_parse_noisily(&file_opts, srcpath, true); 954 if (!opts) { 955 qemu_opts_reset(&file_opts); 956 exit(EXIT_FAILURE); 957 } 958 options = qemu_opts_to_qdict(opts, NULL); 959 qemu_opts_reset(&file_opts); 960 blk = blk_new_open(NULL, NULL, options, flags, &local_err); 961 } else { 962 if (fmt) { 963 options = qdict_new(); 964 qdict_put_str(options, "driver", fmt); 965 } 966 blk = blk_new_open(srcpath, NULL, options, flags, &local_err); 967 } 968 969 if (!blk) { 970 error_reportf_err(local_err, "Failed to blk_new_open '%s': ", 971 argv[optind]); 972 exit(EXIT_FAILURE); 973 } 974 bs = blk_bs(blk); 975 976 blk_set_enable_write_cache(blk, !writethrough); 977 978 if (sn_opts) { 979 ret = bdrv_snapshot_load_tmp(bs, 980 qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID), 981 qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME), 982 &local_err); 983 } else if (sn_id_or_name) { 984 ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name, 985 &local_err); 986 } 987 if (ret < 0) { 988 error_reportf_err(local_err, "Failed to load snapshot: "); 989 exit(EXIT_FAILURE); 990 } 991 992 bs->detect_zeroes = detect_zeroes; 993 fd_size = blk_getlength(blk); 994 if (fd_size < 0) { 995 error_report("Failed to determine the image length: %s", 996 strerror(-fd_size)); 997 exit(EXIT_FAILURE); 998 } 999 1000 if (dev_offset >= fd_size) { 1001 error_report("Offset (%lld) has to be smaller than the image size " 1002 "(%lld)", 1003 (long long int)dev_offset, (long long int)fd_size); 1004 exit(EXIT_FAILURE); 1005 } 1006 fd_size -= dev_offset; 1007 1008 if (partition != -1) { 1009 ret = find_partition(blk, partition, &dev_offset, &fd_size); 1010 if (ret < 0) { 1011 error_report("Could not find partition %d: %s", partition, 1012 strerror(-ret)); 1013 exit(EXIT_FAILURE); 1014 } 1015 } 1016 1017 exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags, nbd_export_closed, 1018 writethrough, NULL, &local_err); 1019 if (!exp) { 1020 error_report_err(local_err); 1021 exit(EXIT_FAILURE); 1022 } 1023 if (export_name) { 1024 nbd_export_set_name(exp, export_name); 1025 nbd_export_set_description(exp, export_description); 1026 newproto = true; 1027 } else if (export_description) { 1028 error_report("Export description requires an export name"); 1029 exit(EXIT_FAILURE); 1030 } 1031 1032 if (device) { 1033 int ret; 1034 1035 ret = pthread_create(&client_thread, NULL, nbd_client_thread, device); 1036 if (ret != 0) { 1037 error_report("Failed to create client thread: %s", strerror(ret)); 1038 exit(EXIT_FAILURE); 1039 } 1040 } else { 1041 /* Shut up GCC warnings. */ 1042 memset(&client_thread, 0, sizeof(client_thread)); 1043 } 1044 1045 nbd_update_server_watch(); 1046 1047 /* now when the initialization is (almost) complete, chdir("/") 1048 * to free any busy filesystems */ 1049 if (chdir("/") < 0) { 1050 error_report("Could not chdir to root directory: %s", 1051 strerror(errno)); 1052 exit(EXIT_FAILURE); 1053 } 1054 1055 if (fork_process) { 1056 dup2(old_stderr, STDERR_FILENO); 1057 close(old_stderr); 1058 } 1059 1060 state = RUNNING; 1061 do { 1062 main_loop_wait(false); 1063 if (state == TERMINATE) { 1064 state = TERMINATING; 1065 nbd_export_close(exp); 1066 nbd_export_put(exp); 1067 exp = NULL; 1068 } 1069 } while (state != TERMINATED); 1070 1071 blk_unref(blk); 1072 if (sockpath) { 1073 unlink(sockpath); 1074 } 1075 1076 qemu_opts_del(sn_opts); 1077 1078 if (device) { 1079 void *ret; 1080 pthread_join(client_thread, &ret); 1081 exit(ret != NULL); 1082 } else { 1083 exit(EXIT_SUCCESS); 1084 } 1085 } 1086