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