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 "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 "block/snapshot.h"
  30 #include "qapi/util.h"
  31 #include "qapi/qmp/qstring.h"
  32 #include "qom/object_interfaces.h"
  33 #include "io/channel-socket.h"
  34
  35 #include <getopt.h>
  36 #include <libgen.h>
  37 #include <pthread.h>
  38
  39 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
  40 #define QEMU_NBD_OPT_CACHE         256
  41 #define QEMU_NBD_OPT_AIO           257
  42 #define QEMU_NBD_OPT_DISCARD       258
  43 #define QEMU_NBD_OPT_DETECT_ZEROES 259
  44 #define QEMU_NBD_OPT_OBJECT        260
  45 #define QEMU_NBD_OPT_TLSCREDS      261
  46 #define QEMU_NBD_OPT_IMAGE_OPTS    262
  47
  48 static NBDExport *exp;
  49 static bool newproto;
  50 static int verbose;
  51 static char *srcpath;
  52 static SocketAddress *saddr;
  53 static int persistent = 0;
  54 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
  55 static int shared = 1;
  56 static int nb_fds;
  57 static QIOChannelSocket *server_ioc;
  58 static int server_watch = -1;
  59 static QCryptoTLSCreds *tlscreds;
  60
  61 static void usage(const char *name)
  62 {
  63     (printf) (
  64 "Usage: %s [OPTIONS] FILE\n"
  65 "QEMU Disk Network Block Device Server\n"
  66 "\n"
  67 "  -h, --help                display this help and exit\n"
  68 "  -V, --version             output version information and exit\n"
  69 "\n"
  70 "Connection properties:\n"
  71 "  -p, --port=PORT           port to listen on (default `%d')\n"
  72 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
  73 "  -k, --socket=PATH         path to the unix socket\n"
  74 "                            (default '"SOCKET_PATH"')\n"
  75 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
  76 "  -t, --persistent          don't exit on the last connection\n"
  77 "  -v, --verbose             display extra debugging information\n"
  78 "  -x, --export-name=NAME    expose export by name\n"
  79 "\n"
  80 "Exposing part of the image:\n"
  81 "  -o, --offset=OFFSET       offset into the image\n"
  82 "  -P, --partition=NUM       only expose partition NUM\n"
  83 "\n"
  84 "General purpose options:\n"
  85 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
  86 "                            passwords and/or encryption keys\n"
  87 #ifdef __linux__
  88 "Kernel NBD client support:\n"
  89 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
  90 "  -d, --disconnect          disconnect the specified device\n"
  91 "\n"
  92 #endif
  93 "\n"
  94 "Block device options:\n"
  95 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
  96 "  -r, --read-only           export read-only\n"
  97 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
  98 "                            file with backing_file=FILE, redirect the write to\n"
  99 "                            the temporary one\n"
 100 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
 101 "                            load an internal snapshot inside FILE and export it\n"
 102 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
 103 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
 104 "                            '[ID_OR_NAME]'\n"
 105 "  -n, --nocache             disable host cache\n"
 106 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
 107 "      --aio=MODE            set AIO mode (native or threads)\n"
 108 "      --discard=MODE        set discard mode (ignore, unmap)\n"
 109 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
 110 "      --image-opts          treat FILE as a full set of image options\n"
 111 "\n"
 112 "Report bugs to <qemu-devel@nongnu.org>\n"
 113     , name, NBD_DEFAULT_PORT, "DEVICE");
 114 }
 115
 116 static void version(const char *name)
 117 {
 118     printf(
 119 "%s version 0.0.1\n"
 120 "Written by Anthony Liguori.\n"
 121 "\n"
 122 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
 123 "This is free software; see the source for copying conditions.  There is NO\n"
 124 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
 125     , name);
 126 }
 127
 128 struct partition_record
 129 {
 130     uint8_t bootable;
 131     uint8_t start_head;
 132     uint32_t start_cylinder;
 133     uint8_t start_sector;
 134     uint8_t system;
 135     uint8_t end_head;
 136     uint8_t end_cylinder;
 137     uint8_t end_sector;
 138     uint32_t start_sector_abs;
 139     uint32_t nb_sectors_abs;
 140 };
 141
 142 static void read_partition(uint8_t *p, struct partition_record *r)
 143 {
 144     r->bootable = p[0];
 145     r->start_head = p[1];
 146     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
 147     r->start_sector = p[2] & 0x3f;
 148     r->system = p[4];
 149     r->end_head = p[5];
 150     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
 151     r->end_sector = p[6] & 0x3f;
 152
 153     r->start_sector_abs = le32_to_cpup((uint32_t *)(p +  8));
 154     r->nb_sectors_abs   = le32_to_cpup((uint32_t *)(p + 12));
 155 }
 156
 157 static int find_partition(BlockBackend *blk, int partition,
 158                           off_t *offset, off_t *size)
 159 {
 160     struct partition_record mbr[4];
 161     uint8_t data[512];
 162     int i;
 163     int ext_partnum = 4;
 164     int ret;
 165
 166     if ((ret = blk_read(blk, 0, data, 1)) < 0) {
 167         error_report("error while reading: %s", strerror(-ret));
 168         exit(EXIT_FAILURE);
 169     }
 170
 171     if (data[510] != 0x55 || data[511] != 0xaa) {
 172         return -EINVAL;
 173     }
 174
 175     for (i = 0; i < 4; i++) {
 176         read_partition(&data[446 + 16 * i], &mbr[i]);
 177
 178         if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
 179             continue;
 180         }
 181
 182         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
 183             struct partition_record ext[4];
 184             uint8_t data1[512];
 185             int j;
 186
 187             if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) {
 188                 error_report("error while reading: %s", strerror(-ret));
 189                 exit(EXIT_FAILURE);
 190             }
 191
 192             for (j = 0; j < 4; j++) {
 193                 read_partition(&data1[446 + 16 * j], &ext[j]);
 194                 if (!ext[j].system || !ext[j].nb_sectors_abs) {
 195                     continue;
 196                 }
 197
 198                 if ((ext_partnum + j + 1) == partition) {
 199                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
 200                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
 201                     return 0;
 202                 }
 203             }
 204             ext_partnum += 4;
 205         } else if ((i + 1) == partition) {
 206             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
 207             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
 208             return 0;
 209         }
 210     }
 211
 212     return -ENOENT;
 213 }
 214
 215 static void termsig_handler(int signum)
 216 {
 217     state = TERMINATE;
 218     qemu_notify_event();
 219 }
 220
 221
 222 static void *show_parts(void *arg)
 223 {
 224     char *device = arg;
 225     int nbd;
 226
 227     /* linux just needs an open() to trigger
 228      * the partition table update
 229      * but remember to load the module with max_part != 0 :
 230      *     modprobe nbd max_part=63
 231      */
 232     nbd = open(device, O_RDWR);
 233     if (nbd >= 0) {
 234         close(nbd);
 235     }
 236     return NULL;
 237 }
 238
 239 static void *nbd_client_thread(void *arg)
 240 {
 241     char *device = arg;
 242     off_t size;
 243     uint32_t nbdflags;
 244     QIOChannelSocket *sioc;
 245     int fd;
 246     int ret;
 247     pthread_t show_parts_thread;
 248     Error *local_error = NULL;
 249
 250     sioc = qio_channel_socket_new();
 251     if (qio_channel_socket_connect_sync(sioc,
 252                                         saddr,
 253                                         &local_error) < 0) {
 254         error_report_err(local_error);
 255         goto out;
 256     }
 257
 258     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, &nbdflags,
 259                                 NULL, NULL, NULL,
 260                                 &size, &local_error);
 261     if (ret < 0) {
 262         if (local_error) {
 263             error_report_err(local_error);
 264         }
 265         goto out_socket;
 266     }
 267
 268     fd = open(device, O_RDWR);
 269     if (fd < 0) {
 270         /* Linux-only, we can use %m in printf.  */
 271         error_report("Failed to open %s: %m", device);
 272         goto out_socket;
 273     }
 274
 275     ret = nbd_init(fd, sioc, nbdflags, size);
 276     if (ret < 0) {
 277         goto out_fd;
 278     }
 279
 280     /* update partition table */
 281     pthread_create(&show_parts_thread, NULL, show_parts, device);
 282
 283     if (verbose) {
 284         fprintf(stderr, "NBD device %s is now connected to %s\n",
 285                 device, srcpath);
 286     } else {
 287         /* Close stderr so that the qemu-nbd process exits.  */
 288         dup2(STDOUT_FILENO, STDERR_FILENO);
 289     }
 290
 291     ret = nbd_client(fd);
 292     if (ret) {
 293         goto out_fd;
 294     }
 295     close(fd);
 296     object_unref(OBJECT(sioc));
 297     kill(getpid(), SIGTERM);
 298     return (void *) EXIT_SUCCESS;
 299
 300 out_fd:
 301     close(fd);
 302 out_socket:
 303     object_unref(OBJECT(sioc));
 304 out:
 305     kill(getpid(), SIGTERM);
 306     return (void *) EXIT_FAILURE;
 307 }
 308
 309 static int nbd_can_accept(void)
 310 {
 311     return nb_fds < shared;
 312 }
 313
 314 static void nbd_export_closed(NBDExport *exp)
 315 {
 316     assert(state == TERMINATING);
 317     state = TERMINATED;
 318 }
 319
 320 static void nbd_update_server_watch(void);
 321
 322 static void nbd_client_closed(NBDClient *client)
 323 {
 324     nb_fds--;
 325     if (nb_fds == 0 && !persistent && state == RUNNING) {
 326         state = TERMINATE;
 327     }
 328     nbd_update_server_watch();
 329     nbd_client_put(client);
 330 }
 331
 332 static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque)
 333 {
 334     QIOChannelSocket *cioc;
 335
 336     cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
 337                                      NULL);
 338     if (!cioc) {
 339         return TRUE;
 340     }
 341
 342     if (state >= TERMINATE) {
 343         object_unref(OBJECT(cioc));
 344         return TRUE;
 345     }
 346
 347     nb_fds++;
 348     nbd_update_server_watch();
 349     nbd_client_new(newproto ? NULL : exp, cioc,
 350                    tlscreds, NULL, nbd_client_closed);
 351     object_unref(OBJECT(cioc));
 352
 353     return TRUE;
 354 }
 355
 356 static void nbd_update_server_watch(void)
 357 {
 358     if (nbd_can_accept()) {
 359         if (server_watch == -1) {
 360             server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc),
 361                                                  G_IO_IN,
 362                                                  nbd_accept,
 363                                                  NULL, NULL);
 364         }
 365     } else {
 366         if (server_watch != -1) {
 367             g_source_remove(server_watch);
 368             server_watch = -1;
 369         }
 370     }
 371 }
 372
 373
 374 static SocketAddress *nbd_build_socket_address(const char *sockpath,
 375                                                const char *bindto,
 376                                                const char *port)
 377 {
 378     SocketAddress *saddr;
 379
 380     saddr = g_new0(SocketAddress, 1);
 381     if (sockpath) {
 382         saddr->type = SOCKET_ADDRESS_KIND_UNIX;
 383         saddr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
 384         saddr->u.q_unix.data->path = g_strdup(sockpath);
 385     } else {
 386         InetSocketAddress *inet;
 387         saddr->type = SOCKET_ADDRESS_KIND_INET;
 388         inet = saddr->u.inet.data = g_new0(InetSocketAddress, 1);
 389         inet->host = g_strdup(bindto);
 390         if (port) {
 391             inet->port = g_strdup(port);
 392         } else  {
 393             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 394         }
 395     }
 396
 397     return saddr;
 398 }
 399
 400
 401 static QemuOptsList file_opts = {
 402     .name = "file",
 403     .implied_opt_name = "file",
 404     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
 405     .desc = {
 406         /* no elements => accept any params */
 407         { /* end of list */ }
 408     },
 409 };
 410
 411 static QemuOptsList qemu_object_opts = {
 412     .name = "object",
 413     .implied_opt_name = "qom-type",
 414     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
 415     .desc = {
 416         { }
 417     },
 418 };
 419
 420
 421
 422 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
 423 {
 424     Object *obj;
 425     QCryptoTLSCreds *creds;
 426
 427     obj = object_resolve_path_component(
 428         object_get_objects_root(), id);
 429     if (!obj) {
 430         error_setg(errp, "No TLS credentials with id '%s'",
 431                    id);
 432         return NULL;
 433     }
 434     creds = (QCryptoTLSCreds *)
 435         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 436     if (!creds) {
 437         error_setg(errp, "Object with id '%s' is not TLS credentials",
 438                    id);
 439         return NULL;
 440     }
 441
 442     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
 443         error_setg(errp,
 444                    "Expecting TLS credentials with a server endpoint");
 445         return NULL;
 446     }
 447     object_ref(obj);
 448     return creds;
 449 }
 450
 451
 452 int main(int argc, char **argv)
 453 {
 454     BlockBackend *blk;
 455     BlockDriverState *bs;
 456     off_t dev_offset = 0;
 457     uint32_t nbdflags = 0;
 458     bool disconnect = false;
 459     const char *bindto = "0.0.0.0";
 460     const char *port = NULL;
 461     char *sockpath = NULL;
 462     char *device = NULL;
 463     off_t fd_size;
 464     QemuOpts *sn_opts = NULL;
 465     const char *sn_id_or_name = NULL;
 466     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:";
 467     struct option lopt[] = {
 468         { "help", no_argument, NULL, 'h' },
 469         { "version", no_argument, NULL, 'V' },
 470         { "bind", required_argument, NULL, 'b' },
 471         { "port", required_argument, NULL, 'p' },
 472         { "socket", required_argument, NULL, 'k' },
 473         { "offset", required_argument, NULL, 'o' },
 474         { "read-only", no_argument, NULL, 'r' },
 475         { "partition", required_argument, NULL, 'P' },
 476         { "connect", required_argument, NULL, 'c' },
 477         { "disconnect", no_argument, NULL, 'd' },
 478         { "snapshot", no_argument, NULL, 's' },
 479         { "load-snapshot", required_argument, NULL, 'l' },
 480         { "nocache", no_argument, NULL, 'n' },
 481         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
 482         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
 483         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
 484         { "detect-zeroes", required_argument, NULL,
 485           QEMU_NBD_OPT_DETECT_ZEROES },
 486         { "shared", required_argument, NULL, 'e' },
 487         { "format", required_argument, NULL, 'f' },
 488         { "persistent", no_argument, NULL, 't' },
 489         { "verbose", no_argument, NULL, 'v' },
 490         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
 491         { "export-name", required_argument, NULL, 'x' },
 492         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
 493         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
 494         { NULL, 0, NULL, 0 }
 495     };
 496     int ch;
 497     int opt_ind = 0;
 498     char *end;
 499     int flags = BDRV_O_RDWR;
 500     int partition = -1;
 501     int ret = 0;
 502     bool seen_cache = false;
 503     bool seen_discard = false;
 504     bool seen_aio = false;
 505     pthread_t client_thread;
 506     const char *fmt = NULL;
 507     Error *local_err = NULL;
 508     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
 509     QDict *options = NULL;
 510     const char *export_name = NULL;
 511     const char *tlscredsid = NULL;
 512     bool imageOpts = false;
 513     bool writethrough = true;
 514
 515     /* The client thread uses SIGTERM to interrupt the server.  A signal
 516      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
 517      */
 518     struct sigaction sa_sigterm;
 519     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
 520     sa_sigterm.sa_handler = termsig_handler;
 521     sigaction(SIGTERM, &sa_sigterm, NULL);
 522     module_call_init(MODULE_INIT_QOM);
 523     qemu_add_opts(&qemu_object_opts);
 524     qemu_init_exec_dir(argv[0]);
 525
 526     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 527         switch (ch) {
 528         case 's':
 529             flags |= BDRV_O_SNAPSHOT;
 530             break;
 531         case 'n':
 532             optarg = (char *) "none";
 533             /* fallthrough */
 534         case QEMU_NBD_OPT_CACHE:
 535             if (seen_cache) {
 536                 error_report("-n and --cache can only be specified once");
 537                 exit(EXIT_FAILURE);
 538             }
 539             seen_cache = true;
 540             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
 541                 error_report("Invalid cache mode `%s'", optarg);
 542                 exit(EXIT_FAILURE);
 543             }
 544             break;
 545         case QEMU_NBD_OPT_AIO:
 546             if (seen_aio) {
 547                 error_report("--aio can only be specified once");
 548                 exit(EXIT_FAILURE);
 549             }
 550             seen_aio = true;
 551             if (!strcmp(optarg, "native")) {
 552                 flags |= BDRV_O_NATIVE_AIO;
 553             } else if (!strcmp(optarg, "threads")) {
 554                 /* this is the default */
 555             } else {
 556                error_report("invalid aio mode `%s'", optarg);
 557                exit(EXIT_FAILURE);
 558             }
 559             break;
 560         case QEMU_NBD_OPT_DISCARD:
 561             if (seen_discard) {
 562                 error_report("--discard can only be specified once");
 563                 exit(EXIT_FAILURE);
 564             }
 565             seen_discard = true;
 566             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 567                 error_report("Invalid discard mode `%s'", optarg);
 568                 exit(EXIT_FAILURE);
 569             }
 570             break;
 571         case QEMU_NBD_OPT_DETECT_ZEROES:
 572             detect_zeroes =
 573                 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
 574                                 optarg,
 575                                 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX,
 576                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
 577                                 &local_err);
 578             if (local_err) {
 579                 error_reportf_err(local_err,
 580                                   "Failed to parse detect_zeroes mode: ");
 581                 exit(EXIT_FAILURE);
 582             }
 583             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
 584                 !(flags & BDRV_O_UNMAP)) {
 585                 error_report("setting detect-zeroes to unmap is not allowed "
 586                              "without setting discard operation to unmap");
 587                 exit(EXIT_FAILURE);
 588             }
 589             break;
 590         case 'b':
 591             bindto = optarg;
 592             break;
 593         case 'p':
 594             port = optarg;
 595             break;
 596         case 'o':
 597                 dev_offset = strtoll (optarg, &end, 0);
 598             if (*end) {
 599                 error_report("Invalid offset `%s'", optarg);
 600                 exit(EXIT_FAILURE);
 601             }
 602             if (dev_offset < 0) {
 603                 error_report("Offset must be positive `%s'", optarg);
 604                 exit(EXIT_FAILURE);
 605             }
 606             break;
 607         case 'l':
 608             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 609                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
 610                                                   optarg, false);
 611                 if (!sn_opts) {
 612                     error_report("Failed in parsing snapshot param `%s'",
 613                                  optarg);
 614                     exit(EXIT_FAILURE);
 615                 }
 616             } else {
 617                 sn_id_or_name = optarg;
 618             }
 619             /* fall through */
 620         case 'r':
 621             nbdflags |= NBD_FLAG_READ_ONLY;
 622             flags &= ~BDRV_O_RDWR;
 623             break;
 624         case 'P':
 625             partition = strtol(optarg, &end, 0);
 626             if (*end) {
 627                 error_report("Invalid partition `%s'", optarg);
 628                 exit(EXIT_FAILURE);
 629             }
 630             if (partition < 1 || partition > 8) {
 631                 error_report("Invalid partition %d", partition);
 632                 exit(EXIT_FAILURE);
 633             }
 634             break;
 635         case 'k':
 636             sockpath = optarg;
 637             if (sockpath[0] != '/') {
 638                 error_report("socket path must be absolute");
 639                 exit(EXIT_FAILURE);
 640             }
 641             break;
 642         case 'd':
 643             disconnect = true;
 644             break;
 645         case 'c':
 646             device = optarg;
 647             break;
 648         case 'e':
 649             shared = strtol(optarg, &end, 0);
 650             if (*end) {
 651                 error_report("Invalid shared device number '%s'", optarg);
 652                 exit(EXIT_FAILURE);
 653             }
 654             if (shared < 1) {
 655                 error_report("Shared device number must be greater than 0");
 656                 exit(EXIT_FAILURE);
 657             }
 658             break;
 659         case 'f':
 660             fmt = optarg;
 661             break;
 662         case 't':
 663             persistent = 1;
 664             break;
 665         case 'x':
 666             export_name = optarg;
 667             break;
 668         case 'v':
 669             verbose = 1;
 670             break;
 671         case 'V':
 672             version(argv[0]);
 673             exit(0);
 674             break;
 675         case 'h':
 676             usage(argv[0]);
 677             exit(0);
 678             break;
 679         case '?':
 680             error_report("Try `%s --help' for more information.", argv[0]);
 681             exit(EXIT_FAILURE);
 682         case QEMU_NBD_OPT_OBJECT: {
 683             QemuOpts *opts;
 684             opts = qemu_opts_parse_noisily(&qemu_object_opts,
 685                                            optarg, true);
 686             if (!opts) {
 687                 exit(EXIT_FAILURE);
 688             }
 689         }   break;
 690         case QEMU_NBD_OPT_TLSCREDS:
 691             tlscredsid = optarg;
 692             break;
 693         case QEMU_NBD_OPT_IMAGE_OPTS:
 694             imageOpts = true;
 695             break;
 696         }
 697     }
 698
 699     if ((argc - optind) != 1) {
 700         error_report("Invalid number of arguments");
 701         error_printf("Try `%s --help' for more information.\n", argv[0]);
 702         exit(EXIT_FAILURE);
 703     }
 704
 705     if (qemu_opts_foreach(&qemu_object_opts,
 706                           user_creatable_add_opts_foreach,
 707                           NULL, &local_err)) {
 708         error_report_err(local_err);
 709         exit(EXIT_FAILURE);
 710     }
 711
 712     if (tlscredsid) {
 713         if (sockpath) {
 714             error_report("TLS is only supported with IPv4/IPv6");
 715             exit(EXIT_FAILURE);
 716         }
 717         if (device) {
 718             error_report("TLS is not supported with a host device");
 719             exit(EXIT_FAILURE);
 720         }
 721         if (!export_name) {
 722             /* Set the default NBD protocol export name, since
 723              * we *must* use new style protocol for TLS */
 724             export_name = "";
 725         }
 726         tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);
 727         if (local_err) {
 728             error_report("Failed to get TLS creds %s",
 729                          error_get_pretty(local_err));
 730             exit(EXIT_FAILURE);
 731         }
 732     }
 733
 734     if (disconnect) {
 735         int nbdfd = open(argv[optind], O_RDWR);
 736         if (nbdfd < 0) {
 737             error_report("Cannot open %s: %s", argv[optind],
 738                          strerror(errno));
 739             exit(EXIT_FAILURE);
 740         }
 741         nbd_disconnect(nbdfd);
 742
 743         close(nbdfd);
 744
 745         printf("%s disconnected\n", argv[optind]);
 746
 747         return 0;
 748     }
 749
 750     if (device && !verbose) {
 751         int stderr_fd[2];
 752         pid_t pid;
 753         int ret;
 754
 755         if (qemu_pipe(stderr_fd) < 0) {
 756             error_report("Error setting up communication pipe: %s",
 757                          strerror(errno));
 758             exit(EXIT_FAILURE);
 759         }
 760
 761         /* Now daemonize, but keep a communication channel open to
 762          * print errors and exit with the proper status code.
 763          */
 764         pid = fork();
 765         if (pid < 0) {
 766             error_report("Failed to fork: %s", strerror(errno));
 767             exit(EXIT_FAILURE);
 768         } else if (pid == 0) {
 769             close(stderr_fd[0]);
 770             ret = qemu_daemon(1, 0);
 771
 772             /* Temporarily redirect stderr to the parent's pipe...  */
 773             dup2(stderr_fd[1], STDERR_FILENO);
 774             if (ret < 0) {
 775                 error_report("Failed to daemonize: %s", strerror(errno));
 776                 exit(EXIT_FAILURE);
 777             }
 778
 779             /* ... close the descriptor we inherited and go on.  */
 780             close(stderr_fd[1]);
 781         } else {
 782             bool errors = false;
 783             char *buf;
 784
 785             /* In the parent.  Print error messages from the child until
 786              * it closes the pipe.
 787              */
 788             close(stderr_fd[1]);
 789             buf = g_malloc(1024);
 790             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
 791                 errors = true;
 792                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
 793                 if (ret < 0) {
 794                     exit(EXIT_FAILURE);
 795                 }
 796             }
 797             if (ret < 0) {
 798                 error_report("Cannot read from daemon: %s",
 799                              strerror(errno));
 800                 exit(EXIT_FAILURE);
 801             }
 802
 803             /* Usually the daemon should not print any message.
 804              * Exit with zero status in that case.
 805              */
 806             exit(errors);
 807         }
 808     }
 809
 810     if (device != NULL && sockpath == NULL) {
 811         sockpath = g_malloc(128);
 812         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
 813     }
 814
 815     saddr = nbd_build_socket_address(sockpath, bindto, port);
 816
 817     if (qemu_init_main_loop(&local_err)) {
 818         error_report_err(local_err);
 819         exit(EXIT_FAILURE);
 820     }
 821     bdrv_init();
 822     atexit(bdrv_close_all);
 823
 824     srcpath = argv[optind];
 825     if (imageOpts) {
 826         QemuOpts *opts;
 827         if (fmt) {
 828             error_report("--image-opts and -f are mutually exclusive");
 829             exit(EXIT_FAILURE);
 830         }
 831         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
 832         if (!opts) {
 833             qemu_opts_reset(&file_opts);
 834             exit(EXIT_FAILURE);
 835         }
 836         options = qemu_opts_to_qdict(opts, NULL);
 837         qemu_opts_reset(&file_opts);
 838         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
 839     } else {
 840         if (fmt) {
 841             options = qdict_new();
 842             qdict_put(options, "driver", qstring_from_str(fmt));
 843         }
 844         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
 845     }
 846
 847     if (!blk) {
 848         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
 849                           argv[optind]);
 850         exit(EXIT_FAILURE);
 851     }
 852     bs = blk_bs(blk);
 853
 854     blk_set_enable_write_cache(blk, !writethrough);
 855
 856     if (sn_opts) {
 857         ret = bdrv_snapshot_load_tmp(bs,
 858                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
 859                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
 860                                      &local_err);
 861     } else if (sn_id_or_name) {
 862         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
 863                                                    &local_err);
 864     }
 865     if (ret < 0) {
 866         error_reportf_err(local_err, "Failed to load snapshot: ");
 867         exit(EXIT_FAILURE);
 868     }
 869
 870     bs->detect_zeroes = detect_zeroes;
 871     fd_size = blk_getlength(blk);
 872     if (fd_size < 0) {
 873         error_report("Failed to determine the image length: %s",
 874                      strerror(-fd_size));
 875         exit(EXIT_FAILURE);
 876     }
 877
 878     if (partition != -1) {
 879         ret = find_partition(blk, partition, &dev_offset, &fd_size);
 880         if (ret < 0) {
 881             error_report("Could not find partition %d: %s", partition,
 882                          strerror(-ret));
 883             exit(EXIT_FAILURE);
 884         }
 885     }
 886
 887     exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed,
 888                          &local_err);
 889     if (!exp) {
 890         error_report_err(local_err);
 891         exit(EXIT_FAILURE);
 892     }
 893     if (export_name) {
 894         nbd_export_set_name(exp, export_name);
 895         newproto = true;
 896     }
 897
 898     server_ioc = qio_channel_socket_new();
 899     if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) {
 900         object_unref(OBJECT(server_ioc));
 901         error_report_err(local_err);
 902         return 1;
 903     }
 904
 905     if (device) {
 906         int ret;
 907
 908         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
 909         if (ret != 0) {
 910             error_report("Failed to create client thread: %s", strerror(ret));
 911             exit(EXIT_FAILURE);
 912         }
 913     } else {
 914         /* Shut up GCC warnings.  */
 915         memset(&client_thread, 0, sizeof(client_thread));
 916     }
 917
 918     nbd_update_server_watch();
 919
 920     /* now when the initialization is (almost) complete, chdir("/")
 921      * to free any busy filesystems */
 922     if (chdir("/") < 0) {
 923         error_report("Could not chdir to root directory: %s",
 924                      strerror(errno));
 925         exit(EXIT_FAILURE);
 926     }
 927
 928     state = RUNNING;
 929     do {
 930         main_loop_wait(false);
 931         if (state == TERMINATE) {
 932             state = TERMINATING;
 933             nbd_export_close(exp);
 934             nbd_export_put(exp);
 935             exp = NULL;
 936         }
 937     } while (state != TERMINATED);
 938
 939     blk_unref(blk);
 940     if (sockpath) {
 941         unlink(sockpath);
 942     }
 943
 944     qemu_opts_del(sn_opts);
 945
 946     if (device) {
 947         void *ret;
 948         pthread_join(client_thread, &ret);
 949         exit(ret != NULL);
 950     } else {
 951         exit(EXIT_SUCCESS);
 952     }
 953 }