qemu-nbd.c

   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 "sysemu/block-backend.h"
  23 #include "block/block_int.h"
  24 #include "block/nbd.h"
  25 #include "qemu/main-loop.h"
  26 #include "qemu/error-report.h"
  27 #include "qemu/config-file.h"
  28 #include "block/snapshot.h"
  29 #include "qapi/util.h"
  30 #include "qapi/qmp/qstring.h"
  31 #include "qom/object_interfaces.h"
  32 #include "io/channel-socket.h"
  33
  34 #include <getopt.h>
  35 #include <libgen.h>
  36 #include <pthread.h>
  37
  38 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
  39 #define QEMU_NBD_OPT_CACHE         256
  40 #define QEMU_NBD_OPT_AIO           257
  41 #define QEMU_NBD_OPT_DISCARD       258
  42 #define QEMU_NBD_OPT_DETECT_ZEROES 259
  43 #define QEMU_NBD_OPT_OBJECT        260
  44 #define QEMU_NBD_OPT_TLSCREDS      261
  45 #define QEMU_NBD_OPT_IMAGE_OPTS    262
  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 "      --image-opts          treat FILE as a full set of image options\n"
 109 "\n"
 110 "Report bugs to <qemu-devel@nongnu.org>\n"
 111     , name, NBD_DEFAULT_PORT, "DEVICE");
 112 }
 113
 114 static void version(const char *name)
 115 {
 116     printf(
 117 "%s version 0.0.1\n"
 118 "Written by Anthony Liguori.\n"
 119 "\n"
 120 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
 121 "This is free software; see the source for copying conditions.  There is NO\n"
 122 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
 123     , name);
 124 }
 125
 126 struct partition_record
 127 {
 128     uint8_t bootable;
 129     uint8_t start_head;
 130     uint32_t start_cylinder;
 131     uint8_t start_sector;
 132     uint8_t system;
 133     uint8_t end_head;
 134     uint8_t end_cylinder;
 135     uint8_t end_sector;
 136     uint32_t start_sector_abs;
 137     uint32_t nb_sectors_abs;
 138 };
 139
 140 static void read_partition(uint8_t *p, struct partition_record *r)
 141 {
 142     r->bootable = p[0];
 143     r->start_head = p[1];
 144     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
 145     r->start_sector = p[2] & 0x3f;
 146     r->system = p[4];
 147     r->end_head = p[5];
 148     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
 149     r->end_sector = p[6] & 0x3f;
 150
 151     r->start_sector_abs = le32_to_cpup((uint32_t *)(p +  8));
 152     r->nb_sectors_abs   = le32_to_cpup((uint32_t *)(p + 12));
 153 }
 154
 155 static int find_partition(BlockBackend *blk, int partition,
 156                           off_t *offset, off_t *size)
 157 {
 158     struct partition_record mbr[4];
 159     uint8_t data[512];
 160     int i;
 161     int ext_partnum = 4;
 162     int ret;
 163
 164     if ((ret = blk_read(blk, 0, data, 1)) < 0) {
 165         error_report("error while reading: %s", strerror(-ret));
 166         exit(EXIT_FAILURE);
 167     }
 168
 169     if (data[510] != 0x55 || data[511] != 0xaa) {
 170         return -EINVAL;
 171     }
 172
 173     for (i = 0; i < 4; i++) {
 174         read_partition(&data[446 + 16 * i], &mbr[i]);
 175
 176         if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
 177             continue;
 178         }
 179
 180         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
 181             struct partition_record ext[4];
 182             uint8_t data1[512];
 183             int j;
 184
 185             if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) {
 186                 error_report("error while reading: %s", strerror(-ret));
 187                 exit(EXIT_FAILURE);
 188             }
 189
 190             for (j = 0; j < 4; j++) {
 191                 read_partition(&data1[446 + 16 * j], &ext[j]);
 192                 if (!ext[j].system || !ext[j].nb_sectors_abs) {
 193                     continue;
 194                 }
 195
 196                 if ((ext_partnum + j + 1) == partition) {
 197                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
 198                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
 199                     return 0;
 200                 }
 201             }
 202             ext_partnum += 4;
 203         } else if ((i + 1) == partition) {
 204             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
 205             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
 206             return 0;
 207         }
 208     }
 209
 210     return -ENOENT;
 211 }
 212
 213 static void termsig_handler(int signum)
 214 {
 215     state = TERMINATE;
 216     qemu_notify_event();
 217 }
 218
 219
 220 static void *show_parts(void *arg)
 221 {
 222     char *device = arg;
 223     int nbd;
 224
 225     /* linux just needs an open() to trigger
 226      * the partition table update
 227      * but remember to load the module with max_part != 0 :
 228      *     modprobe nbd max_part=63
 229      */
 230     nbd = open(device, O_RDWR);
 231     if (nbd >= 0) {
 232         close(nbd);
 233     }
 234     return NULL;
 235 }
 236
 237 static void *nbd_client_thread(void *arg)
 238 {
 239     char *device = arg;
 240     off_t size;
 241     uint32_t nbdflags;
 242     QIOChannelSocket *sioc;
 243     int fd;
 244     int ret;
 245     pthread_t show_parts_thread;
 246     Error *local_error = NULL;
 247
 248     sioc = qio_channel_socket_new();
 249     if (qio_channel_socket_connect_sync(sioc,
 250                                         saddr,
 251                                         &local_error) < 0) {
 252         error_report_err(local_error);
 253         goto out;
 254     }
 255
 256     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, &nbdflags,
 257                                 NULL, NULL, NULL,
 258                                 &size, &local_error);
 259     if (ret < 0) {
 260         if (local_error) {
 261             error_report_err(local_error);
 262         }
 263         goto out_socket;
 264     }
 265
 266     fd = open(device, O_RDWR);
 267     if (fd < 0) {
 268         /* Linux-only, we can use %m in printf.  */
 269         error_report("Failed to open %s: %m", device);
 270         goto out_socket;
 271     }
 272
 273     ret = nbd_init(fd, sioc, nbdflags, size);
 274     if (ret < 0) {
 275         goto out_fd;
 276     }
 277
 278     /* update partition table */
 279     pthread_create(&show_parts_thread, NULL, show_parts, device);
 280
 281     if (verbose) {
 282         fprintf(stderr, "NBD device %s is now connected to %s\n",
 283                 device, srcpath);
 284     } else {
 285         /* Close stderr so that the qemu-nbd process exits.  */
 286         dup2(STDOUT_FILENO, STDERR_FILENO);
 287     }
 288
 289     ret = nbd_client(fd);
 290     if (ret) {
 291         goto out_fd;
 292     }
 293     close(fd);
 294     object_unref(OBJECT(sioc));
 295     kill(getpid(), SIGTERM);
 296     return (void *) EXIT_SUCCESS;
 297
 298 out_fd:
 299     close(fd);
 300 out_socket:
 301     object_unref(OBJECT(sioc));
 302 out:
 303     kill(getpid(), SIGTERM);
 304     return (void *) EXIT_FAILURE;
 305 }
 306
 307 static int nbd_can_accept(void)
 308 {
 309     return nb_fds < shared;
 310 }
 311
 312 static void nbd_export_closed(NBDExport *exp)
 313 {
 314     assert(state == TERMINATING);
 315     state = TERMINATED;
 316 }
 317
 318 static void nbd_update_server_watch(void);
 319
 320 static void nbd_client_closed(NBDClient *client)
 321 {
 322     nb_fds--;
 323     if (nb_fds == 0 && !persistent && state == RUNNING) {
 324         state = TERMINATE;
 325     }
 326     nbd_update_server_watch();
 327     nbd_client_put(client);
 328 }
 329
 330 static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque)
 331 {
 332     QIOChannelSocket *cioc;
 333
 334     cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
 335                                      NULL);
 336     if (!cioc) {
 337         return TRUE;
 338     }
 339
 340     if (state >= TERMINATE) {
 341         object_unref(OBJECT(cioc));
 342         return TRUE;
 343     }
 344
 345     nb_fds++;
 346     nbd_update_server_watch();
 347     nbd_client_new(newproto ? NULL : exp, cioc,
 348                    tlscreds, NULL, nbd_client_closed);
 349     object_unref(OBJECT(cioc));
 350
 351     return TRUE;
 352 }
 353
 354 static void nbd_update_server_watch(void)
 355 {
 356     if (nbd_can_accept()) {
 357         if (server_watch == -1) {
 358             server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc),
 359                                                  G_IO_IN,
 360                                                  nbd_accept,
 361                                                  NULL, NULL);
 362         }
 363     } else {
 364         if (server_watch != -1) {
 365             g_source_remove(server_watch);
 366             server_watch = -1;
 367         }
 368     }
 369 }
 370
 371
 372 static SocketAddress *nbd_build_socket_address(const char *sockpath,
 373                                                const char *bindto,
 374                                                const char *port)
 375 {
 376     SocketAddress *saddr;
 377
 378     saddr = g_new0(SocketAddress, 1);
 379     if (sockpath) {
 380         saddr->type = SOCKET_ADDRESS_KIND_UNIX;
 381         saddr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
 382         saddr->u.q_unix.data->path = g_strdup(sockpath);
 383     } else {
 384         InetSocketAddress *inet;
 385         saddr->type = SOCKET_ADDRESS_KIND_INET;
 386         inet = saddr->u.inet.data = g_new0(InetSocketAddress, 1);
 387         inet->host = g_strdup(bindto);
 388         if (port) {
 389             inet->port = g_strdup(port);
 390         } else  {
 391             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 392         }
 393     }
 394
 395     return saddr;
 396 }
 397
 398
 399 static QemuOptsList file_opts = {
 400     .name = "file",
 401     .implied_opt_name = "file",
 402     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
 403     .desc = {
 404         /* no elements => accept any params */
 405         { /* end of list */ }
 406     },
 407 };
 408
 409 static QemuOptsList qemu_object_opts = {
 410     .name = "object",
 411     .implied_opt_name = "qom-type",
 412     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
 413     .desc = {
 414         { }
 415     },
 416 };
 417
 418
 419
 420 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
 421 {
 422     Object *obj;
 423     QCryptoTLSCreds *creds;
 424
 425     obj = object_resolve_path_component(
 426         object_get_objects_root(), id);
 427     if (!obj) {
 428         error_setg(errp, "No TLS credentials with id '%s'",
 429                    id);
 430         return NULL;
 431     }
 432     creds = (QCryptoTLSCreds *)
 433         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 434     if (!creds) {
 435         error_setg(errp, "Object with id '%s' is not TLS credentials",
 436                    id);
 437         return NULL;
 438     }
 439
 440     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
 441         error_setg(errp,
 442                    "Expecting TLS credentials with a server endpoint");
 443         return NULL;
 444     }
 445     object_ref(obj);
 446     return creds;
 447 }
 448
 449
 450 int main(int argc, char **argv)
 451 {
 452     BlockBackend *blk;
 453     BlockDriverState *bs;
 454     off_t dev_offset = 0;
 455     uint32_t nbdflags = 0;
 456     bool disconnect = false;
 457     const char *bindto = "0.0.0.0";
 458     const char *port = NULL;
 459     char *sockpath = NULL;
 460     char *device = NULL;
 461     off_t fd_size;
 462     QemuOpts *sn_opts = NULL;
 463     const char *sn_id_or_name = NULL;
 464     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:";
 465     struct option lopt[] = {
 466         { "help", no_argument, NULL, 'h' },
 467         { "version", no_argument, NULL, 'V' },
 468         { "bind", required_argument, NULL, 'b' },
 469         { "port", required_argument, NULL, 'p' },
 470         { "socket", required_argument, NULL, 'k' },
 471         { "offset", required_argument, NULL, 'o' },
 472         { "read-only", no_argument, NULL, 'r' },
 473         { "partition", required_argument, NULL, 'P' },
 474         { "connect", required_argument, NULL, 'c' },
 475         { "disconnect", no_argument, NULL, 'd' },
 476         { "snapshot", no_argument, NULL, 's' },
 477         { "load-snapshot", required_argument, NULL, 'l' },
 478         { "nocache", no_argument, NULL, 'n' },
 479         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
 480         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
 481         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
 482         { "detect-zeroes", required_argument, NULL,
 483           QEMU_NBD_OPT_DETECT_ZEROES },
 484         { "shared", required_argument, NULL, 'e' },
 485         { "format", required_argument, NULL, 'f' },
 486         { "persistent", no_argument, NULL, 't' },
 487         { "verbose", no_argument, NULL, 'v' },
 488         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
 489         { "export-name", required_argument, NULL, 'x' },
 490         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
 491         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
 492         { NULL, 0, NULL, 0 }
 493     };
 494     int ch;
 495     int opt_ind = 0;
 496     char *end;
 497     int flags = BDRV_O_RDWR;
 498     int partition = -1;
 499     int ret = 0;
 500     bool seen_cache = false;
 501     bool seen_discard = false;
 502     bool seen_aio = false;
 503     pthread_t client_thread;
 504     const char *fmt = NULL;
 505     Error *local_err = NULL;
 506     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
 507     QDict *options = NULL;
 508     const char *export_name = NULL;
 509     const char *tlscredsid = NULL;
 510     bool imageOpts = false;
 511
 512     /* The client thread uses SIGTERM to interrupt the server.  A signal
 513      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
 514      */
 515     struct sigaction sa_sigterm;
 516     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
 517     sa_sigterm.sa_handler = termsig_handler;
 518     sigaction(SIGTERM, &sa_sigterm, NULL);
 519     module_call_init(MODULE_INIT_QOM);
 520     qemu_add_opts(&qemu_object_opts);
 521     qemu_init_exec_dir(argv[0]);
 522
 523     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 524         switch (ch) {
 525         case 's':
 526             flags |= BDRV_O_SNAPSHOT;
 527             break;
 528         case 'n':
 529             optarg = (char *) "none";
 530             /* fallthrough */
 531         case QEMU_NBD_OPT_CACHE:
 532             if (seen_cache) {
 533                 error_report("-n and --cache can only be specified once");
 534                 exit(EXIT_FAILURE);
 535             }
 536             seen_cache = true;
 537             if (bdrv_parse_cache_flags(optarg, &flags) == -1) {
 538                 error_report("Invalid cache mode `%s'", optarg);
 539                 exit(EXIT_FAILURE);
 540             }
 541             break;
 542         case QEMU_NBD_OPT_AIO:
 543             if (seen_aio) {
 544                 error_report("--aio can only be specified once");
 545                 exit(EXIT_FAILURE);
 546             }
 547             seen_aio = true;
 548             if (!strcmp(optarg, "native")) {
 549                 flags |= BDRV_O_NATIVE_AIO;
 550             } else if (!strcmp(optarg, "threads")) {
 551                 /* this is the default */
 552             } else {
 553                error_report("invalid aio mode `%s'", optarg);
 554                exit(EXIT_FAILURE);
 555             }
 556             break;
 557         case QEMU_NBD_OPT_DISCARD:
 558             if (seen_discard) {
 559                 error_report("--discard can only be specified once");
 560                 exit(EXIT_FAILURE);
 561             }
 562             seen_discard = true;
 563             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 564                 error_report("Invalid discard mode `%s'", optarg);
 565                 exit(EXIT_FAILURE);
 566             }
 567             break;
 568         case QEMU_NBD_OPT_DETECT_ZEROES:
 569             detect_zeroes =
 570                 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
 571                                 optarg,
 572                                 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX,
 573                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
 574                                 &local_err);
 575             if (local_err) {
 576                 error_reportf_err(local_err,
 577                                   "Failed to parse detect_zeroes mode: ");
 578                 exit(EXIT_FAILURE);
 579             }
 580             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
 581                 !(flags & BDRV_O_UNMAP)) {
 582                 error_report("setting detect-zeroes to unmap is not allowed "
 583                              "without setting discard operation to unmap");
 584                 exit(EXIT_FAILURE);
 585             }
 586             break;
 587         case 'b':
 588             bindto = optarg;
 589             break;
 590         case 'p':
 591             port = optarg;
 592             break;
 593         case 'o':
 594                 dev_offset = strtoll (optarg, &end, 0);
 595             if (*end) {
 596                 error_report("Invalid offset `%s'", optarg);
 597                 exit(EXIT_FAILURE);
 598             }
 599             if (dev_offset < 0) {
 600                 error_report("Offset must be positive `%s'", optarg);
 601                 exit(EXIT_FAILURE);
 602             }
 603             break;
 604         case 'l':
 605             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 606                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
 607                                                   optarg, false);
 608                 if (!sn_opts) {
 609                     error_report("Failed in parsing snapshot param `%s'",
 610                                  optarg);
 611                     exit(EXIT_FAILURE);
 612                 }
 613             } else {
 614                 sn_id_or_name = optarg;
 615             }
 616             /* fall through */
 617         case 'r':
 618             nbdflags |= NBD_FLAG_READ_ONLY;
 619             flags &= ~BDRV_O_RDWR;
 620             break;
 621         case 'P':
 622             partition = strtol(optarg, &end, 0);
 623             if (*end) {
 624                 error_report("Invalid partition `%s'", optarg);
 625                 exit(EXIT_FAILURE);
 626             }
 627             if (partition < 1 || partition > 8) {
 628                 error_report("Invalid partition %d", partition);
 629                 exit(EXIT_FAILURE);
 630             }
 631             break;
 632         case 'k':
 633             sockpath = optarg;
 634             if (sockpath[0] != '/') {
 635                 error_report("socket path must be absolute");
 636                 exit(EXIT_FAILURE);
 637             }
 638             break;
 639         case 'd':
 640             disconnect = true;
 641             break;
 642         case 'c':
 643             device = optarg;
 644             break;
 645         case 'e':
 646             shared = strtol(optarg, &end, 0);
 647             if (*end) {
 648                 error_report("Invalid shared device number '%s'", optarg);
 649                 exit(EXIT_FAILURE);
 650             }
 651             if (shared < 1) {
 652                 error_report("Shared device number must be greater than 0");
 653                 exit(EXIT_FAILURE);
 654             }
 655             break;
 656         case 'f':
 657             fmt = optarg;
 658             break;
 659         case 't':
 660             persistent = 1;
 661             break;
 662         case 'x':
 663             export_name = optarg;
 664             break;
 665         case 'v':
 666             verbose = 1;
 667             break;
 668         case 'V':
 669             version(argv[0]);
 670             exit(0);
 671             break;
 672         case 'h':
 673             usage(argv[0]);
 674             exit(0);
 675             break;
 676         case '?':
 677             error_report("Try `%s --help' for more information.", argv[0]);
 678             exit(EXIT_FAILURE);
 679         case QEMU_NBD_OPT_OBJECT: {
 680             QemuOpts *opts;
 681             opts = qemu_opts_parse_noisily(&qemu_object_opts,
 682                                            optarg, true);
 683             if (!opts) {
 684                 exit(EXIT_FAILURE);
 685             }
 686         }   break;
 687         case QEMU_NBD_OPT_TLSCREDS:
 688             tlscredsid = optarg;
 689             break;
 690         case QEMU_NBD_OPT_IMAGE_OPTS:
 691             imageOpts = true;
 692             break;
 693         }
 694     }
 695
 696     if ((argc - optind) != 1) {
 697         error_report("Invalid number of arguments");
 698         error_printf("Try `%s --help' for more information.\n", argv[0]);
 699         exit(EXIT_FAILURE);
 700     }
 701
 702     if (qemu_opts_foreach(&qemu_object_opts,
 703                           user_creatable_add_opts_foreach,
 704                           NULL, &local_err)) {
 705         error_report_err(local_err);
 706         exit(EXIT_FAILURE);
 707     }
 708
 709     if (tlscredsid) {
 710         if (sockpath) {
 711             error_report("TLS is only supported with IPv4/IPv6");
 712             exit(EXIT_FAILURE);
 713         }
 714         if (device) {
 715             error_report("TLS is not supported with a host device");
 716             exit(EXIT_FAILURE);
 717         }
 718         if (!export_name) {
 719             /* Set the default NBD protocol export name, since
 720              * we *must* use new style protocol for TLS */
 721             export_name = "";
 722         }
 723         tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);
 724         if (local_err) {
 725             error_report("Failed to get TLS creds %s",
 726                          error_get_pretty(local_err));
 727             exit(EXIT_FAILURE);
 728         }
 729     }
 730
 731     if (disconnect) {
 732         int nbdfd = open(argv[optind], O_RDWR);
 733         if (nbdfd < 0) {
 734             error_report("Cannot open %s: %s", argv[optind],
 735                          strerror(errno));
 736             exit(EXIT_FAILURE);
 737         }
 738         nbd_disconnect(nbdfd);
 739
 740         close(nbdfd);
 741
 742         printf("%s disconnected\n", argv[optind]);
 743
 744         return 0;
 745     }
 746
 747     if (device && !verbose) {
 748         int stderr_fd[2];
 749         pid_t pid;
 750         int ret;
 751
 752         if (qemu_pipe(stderr_fd) < 0) {
 753             error_report("Error setting up communication pipe: %s",
 754                          strerror(errno));
 755             exit(EXIT_FAILURE);
 756         }
 757
 758         /* Now daemonize, but keep a communication channel open to
 759          * print errors and exit with the proper status code.
 760          */
 761         pid = fork();
 762         if (pid < 0) {
 763             error_report("Failed to fork: %s", strerror(errno));
 764             exit(EXIT_FAILURE);
 765         } else if (pid == 0) {
 766             close(stderr_fd[0]);
 767             ret = qemu_daemon(1, 0);
 768
 769             /* Temporarily redirect stderr to the parent's pipe...  */
 770             dup2(stderr_fd[1], STDERR_FILENO);
 771             if (ret < 0) {
 772                 error_report("Failed to daemonize: %s", strerror(errno));
 773                 exit(EXIT_FAILURE);
 774             }
 775
 776             /* ... close the descriptor we inherited and go on.  */
 777             close(stderr_fd[1]);
 778         } else {
 779             bool errors = false;
 780             char *buf;
 781
 782             /* In the parent.  Print error messages from the child until
 783              * it closes the pipe.
 784              */
 785             close(stderr_fd[1]);
 786             buf = g_malloc(1024);
 787             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
 788                 errors = true;
 789                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
 790                 if (ret < 0) {
 791                     exit(EXIT_FAILURE);
 792                 }
 793             }
 794             if (ret < 0) {
 795                 error_report("Cannot read from daemon: %s",
 796                              strerror(errno));
 797                 exit(EXIT_FAILURE);
 798             }
 799
 800             /* Usually the daemon should not print any message.
 801              * Exit with zero status in that case.
 802              */
 803             exit(errors);
 804         }
 805     }
 806
 807     if (device != NULL && sockpath == NULL) {
 808         sockpath = g_malloc(128);
 809         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
 810     }
 811
 812     saddr = nbd_build_socket_address(sockpath, bindto, port);
 813
 814     if (qemu_init_main_loop(&local_err)) {
 815         error_report_err(local_err);
 816         exit(EXIT_FAILURE);
 817     }
 818     bdrv_init();
 819     atexit(bdrv_close_all);
 820
 821     srcpath = argv[optind];
 822     if (imageOpts) {
 823         QemuOpts *opts;
 824         if (fmt) {
 825             error_report("--image-opts and -f are mutually exclusive");
 826             exit(EXIT_FAILURE);
 827         }
 828         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
 829         if (!opts) {
 830             qemu_opts_reset(&file_opts);
 831             exit(EXIT_FAILURE);
 832         }
 833         options = qemu_opts_to_qdict(opts, NULL);
 834         qemu_opts_reset(&file_opts);
 835         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
 836     } else {
 837         if (fmt) {
 838             options = qdict_new();
 839             qdict_put(options, "driver", qstring_from_str(fmt));
 840         }
 841         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
 842     }
 843
 844     if (!blk) {
 845         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
 846                           argv[optind]);
 847         exit(EXIT_FAILURE);
 848     }
 849     bs = blk_bs(blk);
 850
 851     if (sn_opts) {
 852         ret = bdrv_snapshot_load_tmp(bs,
 853                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
 854                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
 855                                      &local_err);
 856     } else if (sn_id_or_name) {
 857         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
 858                                                    &local_err);
 859     }
 860     if (ret < 0) {
 861         error_reportf_err(local_err, "Failed to load snapshot: ");
 862         exit(EXIT_FAILURE);
 863     }
 864
 865     bs->detect_zeroes = detect_zeroes;
 866     fd_size = blk_getlength(blk);
 867     if (fd_size < 0) {
 868         error_report("Failed to determine the image length: %s",
 869                      strerror(-fd_size));
 870         exit(EXIT_FAILURE);
 871     }
 872
 873     if (partition != -1) {
 874         ret = find_partition(blk, partition, &dev_offset, &fd_size);
 875         if (ret < 0) {
 876             error_report("Could not find partition %d: %s", partition,
 877                          strerror(-ret));
 878             exit(EXIT_FAILURE);
 879         }
 880     }
 881
 882     exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed,
 883                          &local_err);
 884     if (!exp) {
 885         error_report_err(local_err);
 886         exit(EXIT_FAILURE);
 887     }
 888     if (export_name) {
 889         nbd_export_set_name(exp, export_name);
 890         newproto = true;
 891     }
 892
 893     server_ioc = qio_channel_socket_new();
 894     if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) {
 895         object_unref(OBJECT(server_ioc));
 896         error_report_err(local_err);
 897         return 1;
 898     }
 899
 900     if (device) {
 901         int ret;
 902
 903         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
 904         if (ret != 0) {
 905             error_report("Failed to create client thread: %s", strerror(ret));
 906             exit(EXIT_FAILURE);
 907         }
 908     } else {
 909         /* Shut up GCC warnings.  */
 910         memset(&client_thread, 0, sizeof(client_thread));
 911     }
 912
 913     nbd_update_server_watch();
 914
 915     /* now when the initialization is (almost) complete, chdir("/")
 916      * to free any busy filesystems */
 917     if (chdir("/") < 0) {
 918         error_report("Could not chdir to root directory: %s",
 919                      strerror(errno));
 920         exit(EXIT_FAILURE);
 921     }
 922
 923     state = RUNNING;
 924     do {
 925         main_loop_wait(false);
 926         if (state == TERMINATE) {
 927             state = TERMINATING;
 928             nbd_export_close(exp);
 929             nbd_export_put(exp);
 930             exp = NULL;
 931         }
 932     } while (state != TERMINATED);
 933
 934     blk_unref(blk);
 935     if (sockpath) {
 936         unlink(sockpath);
 937     }
 938
 939     qemu_opts_del(sn_opts);
 940
 941     if (device) {
 942         void *ret;
 943         pthread_join(client_thread, &ret);
 944         exit(ret != NULL);
 945     } else {
 946         exit(EXIT_SUCCESS);
 947     }
 948 }