qemu/qemu-nbd.c
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   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#include "crypto/init.h"
  35
  36#include <getopt.h>
  37#include <libgen.h>
  38#include <pthread.h>
  39
  40#define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
  41#define QEMU_NBD_OPT_CACHE         256
  42#define QEMU_NBD_OPT_AIO           257
  43#define QEMU_NBD_OPT_DISCARD       258
  44#define QEMU_NBD_OPT_DETECT_ZEROES 259
  45#define QEMU_NBD_OPT_OBJECT        260
  46#define QEMU_NBD_OPT_TLSCREDS      261
  47#define QEMU_NBD_OPT_IMAGE_OPTS    262
  48
  49static NBDExport *exp;
  50static bool newproto;
  51static int verbose;
  52static char *srcpath;
  53static SocketAddress *saddr;
  54static int persistent = 0;
  55static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
  56static int shared = 1;
  57static int nb_fds;
  58static QIOChannelSocket *server_ioc;
  59static int server_watch = -1;
  60static QCryptoTLSCreds *tlscreds;
  61
  62static void usage(const char *name)
  63{
  64    (printf) (
  65"Usage: %s [OPTIONS] FILE\n"
  66"QEMU Disk Network Block Device Server\n"
  67"\n"
  68"  -h, --help                display this help and exit\n"
  69"  -V, --version             output version information and exit\n"
  70"\n"
  71"Connection properties:\n"
  72"  -p, --port=PORT           port to listen on (default `%d')\n"
  73"  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
  74"  -k, --socket=PATH         path to the unix socket\n"
  75"                            (default '"SOCKET_PATH"')\n"
  76"  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
  77"  -t, --persistent          don't exit on the last connection\n"
  78"  -v, --verbose             display extra debugging information\n"
  79"  -x, --export-name=NAME    expose export by name\n"
  80"\n"
  81"Exposing part of the image:\n"
  82"  -o, --offset=OFFSET       offset into the image\n"
  83"  -P, --partition=NUM       only expose partition NUM\n"
  84"\n"
  85"General purpose options:\n"
  86"  --object type,id=ID,...   define an object such as 'secret' for providing\n"
  87"                            passwords and/or encryption keys\n"
  88#ifdef __linux__
  89"Kernel NBD client support:\n"
  90"  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
  91"  -d, --disconnect          disconnect the specified device\n"
  92"\n"
  93#endif
  94"\n"
  95"Block device options:\n"
  96"  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
  97"  -r, --read-only           export read-only\n"
  98"  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
  99"                            file with backing_file=FILE, redirect the write to\n"
 100"                            the temporary one\n"
 101"  -l, --load-snapshot=SNAPSHOT_PARAM\n"
 102"                            load an internal snapshot inside FILE and export it\n"
 103"                            as an read-only device, SNAPSHOT_PARAM format is\n"
 104"                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
 105"                            '[ID_OR_NAME]'\n"
 106"  -n, --nocache             disable host cache\n"
 107"      --cache=MODE          set cache mode (none, writeback, ...)\n"
 108"      --aio=MODE            set AIO mode (native or threads)\n"
 109"      --discard=MODE        set discard mode (ignore, unmap)\n"
 110"      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
 111"      --image-opts          treat FILE as a full set of image options\n"
 112"\n"
 113"Report bugs to <qemu-devel@nongnu.org>\n"
 114    , name, NBD_DEFAULT_PORT, "DEVICE");
 115}
 116
 117static void version(const char *name)
 118{
 119    printf(
 120"%s version 0.0.1\n"
 121"Written by Anthony Liguori.\n"
 122"\n"
 123"Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
 124"This is free software; see the source for copying conditions.  There is NO\n"
 125"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
 126    , name);
 127}
 128
 129struct partition_record
 130{
 131    uint8_t bootable;
 132    uint8_t start_head;
 133    uint32_t start_cylinder;
 134    uint8_t start_sector;
 135    uint8_t system;
 136    uint8_t end_head;
 137    uint8_t end_cylinder;
 138    uint8_t end_sector;
 139    uint32_t start_sector_abs;
 140    uint32_t nb_sectors_abs;
 141};
 142
 143static void read_partition(uint8_t *p, struct partition_record *r)
 144{
 145    r->bootable = p[0];
 146    r->start_head = p[1];
 147    r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
 148    r->start_sector = p[2] & 0x3f;
 149    r->system = p[4];
 150    r->end_head = p[5];
 151    r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
 152    r->end_sector = p[6] & 0x3f;
 153
 154    r->start_sector_abs = le32_to_cpup((uint32_t *)(p +  8));
 155    r->nb_sectors_abs   = le32_to_cpup((uint32_t *)(p + 12));
 156}
 157
 158static int find_partition(BlockBackend *blk, int partition,
 159                          off_t *offset, off_t *size)
 160{
 161    struct partition_record mbr[4];
 162    uint8_t data[512];
 163    int i;
 164    int ext_partnum = 4;
 165    int ret;
 166
 167    if ((ret = blk_read(blk, 0, data, 1)) < 0) {
 168        error_report("error while reading: %s", strerror(-ret));
 169        exit(EXIT_FAILURE);
 170    }
 171
 172    if (data[510] != 0x55 || data[511] != 0xaa) {
 173        return -EINVAL;
 174    }
 175
 176    for (i = 0; i < 4; i++) {
 177        read_partition(&data[446 + 16 * i], &mbr[i]);
 178
 179        if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
 180            continue;
 181        }
 182
 183        if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
 184            struct partition_record ext[4];
 185            uint8_t data1[512];
 186            int j;
 187
 188            if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) {
 189                error_report("error while reading: %s", strerror(-ret));
 190                exit(EXIT_FAILURE);
 191            }
 192
 193            for (j = 0; j < 4; j++) {
 194                read_partition(&data1[446 + 16 * j], &ext[j]);
 195                if (!ext[j].system || !ext[j].nb_sectors_abs) {
 196                    continue;
 197                }
 198
 199                if ((ext_partnum + j + 1) == partition) {
 200                    *offset = (uint64_t)ext[j].start_sector_abs << 9;
 201                    *size = (uint64_t)ext[j].nb_sectors_abs << 9;
 202                    return 0;
 203                }
 204            }
 205            ext_partnum += 4;
 206        } else if ((i + 1) == partition) {
 207            *offset = (uint64_t)mbr[i].start_sector_abs << 9;
 208            *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
 209            return 0;
 210        }
 211    }
 212
 213    return -ENOENT;
 214}
 215
 216static void termsig_handler(int signum)
 217{
 218    atomic_cmpxchg(&state, RUNNING, TERMINATE);
 219    qemu_notify_event();
 220}
 221
 222
 223static void *show_parts(void *arg)
 224{
 225    char *device = arg;
 226    int nbd;
 227
 228    /* linux just needs an open() to trigger
 229     * the partition table update
 230     * but remember to load the module with max_part != 0 :
 231     *     modprobe nbd max_part=63
 232     */
 233    nbd = open(device, O_RDWR);
 234    if (nbd >= 0) {
 235        close(nbd);
 236    }
 237    return NULL;
 238}
 239
 240static void *nbd_client_thread(void *arg)
 241{
 242    char *device = arg;
 243    off_t size;
 244    uint32_t nbdflags;
 245    QIOChannelSocket *sioc;
 246    int fd;
 247    int ret;
 248    pthread_t show_parts_thread;
 249    Error *local_error = NULL;
 250
 251    sioc = qio_channel_socket_new();
 252    if (qio_channel_socket_connect_sync(sioc,
 253                                        saddr,
 254                                        &local_error) < 0) {
 255        error_report_err(local_error);
 256        goto out;
 257    }
 258
 259    ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, &nbdflags,
 260                                NULL, NULL, NULL,
 261                                &size, &local_error);
 262    if (ret < 0) {
 263        if (local_error) {
 264            error_report_err(local_error);
 265        }
 266        goto out_socket;
 267    }
 268
 269    fd = open(device, O_RDWR);
 270    if (fd < 0) {
 271        /* Linux-only, we can use %m in printf.  */
 272        error_report("Failed to open %s: %m", device);
 273        goto out_socket;
 274    }
 275
 276    ret = nbd_init(fd, sioc, nbdflags, size);
 277    if (ret < 0) {
 278        goto out_fd;
 279    }
 280
 281    /* update partition table */
 282    pthread_create(&show_parts_thread, NULL, show_parts, device);
 283
 284    if (verbose) {
 285        fprintf(stderr, "NBD device %s is now connected to %s\n",
 286                device, srcpath);
 287    } else {
 288        /* Close stderr so that the qemu-nbd process exits.  */
 289        dup2(STDOUT_FILENO, STDERR_FILENO);
 290    }
 291
 292    ret = nbd_client(fd);
 293    if (ret) {
 294        goto out_fd;
 295    }
 296    close(fd);
 297    object_unref(OBJECT(sioc));
 298    kill(getpid(), SIGTERM);
 299    return (void *) EXIT_SUCCESS;
 300
 301out_fd:
 302    close(fd);
 303out_socket:
 304    object_unref(OBJECT(sioc));
 305out:
 306    kill(getpid(), SIGTERM);
 307    return (void *) EXIT_FAILURE;
 308}
 309
 310static int nbd_can_accept(void)
 311{
 312    return nb_fds < shared;
 313}
 314
 315static void nbd_export_closed(NBDExport *exp)
 316{
 317    assert(state == TERMINATING);
 318    state = TERMINATED;
 319}
 320
 321static void nbd_update_server_watch(void);
 322
 323static void nbd_client_closed(NBDClient *client)
 324{
 325    nb_fds--;
 326    if (nb_fds == 0 && !persistent && state == RUNNING) {
 327        state = TERMINATE;
 328    }
 329    nbd_update_server_watch();
 330    nbd_client_put(client);
 331}
 332
 333static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque)
 334{
 335    QIOChannelSocket *cioc;
 336
 337    cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
 338                                     NULL);
 339    if (!cioc) {
 340        return TRUE;
 341    }
 342
 343    if (state >= TERMINATE) {
 344        object_unref(OBJECT(cioc));
 345        return TRUE;
 346    }
 347
 348    nb_fds++;
 349    nbd_update_server_watch();
 350    nbd_client_new(newproto ? NULL : exp, cioc,
 351                   tlscreds, NULL, nbd_client_closed);
 352    object_unref(OBJECT(cioc));
 353
 354    return TRUE;
 355}
 356
 357static void nbd_update_server_watch(void)
 358{
 359    if (nbd_can_accept()) {
 360        if (server_watch == -1) {
 361            server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc),
 362                                                 G_IO_IN,
 363                                                 nbd_accept,
 364                                                 NULL, NULL);
 365        }
 366    } else {
 367        if (server_watch != -1) {
 368            g_source_remove(server_watch);
 369            server_watch = -1;
 370        }
 371    }
 372}
 373
 374
 375static SocketAddress *nbd_build_socket_address(const char *sockpath,
 376                                               const char *bindto,
 377                                               const char *port)
 378{
 379    SocketAddress *saddr;
 380
 381    saddr = g_new0(SocketAddress, 1);
 382    if (sockpath) {
 383        saddr->type = SOCKET_ADDRESS_KIND_UNIX;
 384        saddr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
 385        saddr->u.q_unix.data->path = g_strdup(sockpath);
 386    } else {
 387        InetSocketAddress *inet;
 388        saddr->type = SOCKET_ADDRESS_KIND_INET;
 389        inet = saddr->u.inet.data = g_new0(InetSocketAddress, 1);
 390        inet->host = g_strdup(bindto);
 391        if (port) {
 392            inet->port = g_strdup(port);
 393        } else  {
 394            inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 395        }
 396    }
 397
 398    return saddr;
 399}
 400
 401
 402static QemuOptsList file_opts = {
 403    .name = "file",
 404    .implied_opt_name = "file",
 405    .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
 406    .desc = {
 407        /* no elements => accept any params */
 408        { /* end of list */ }
 409    },
 410};
 411
 412static QemuOptsList qemu_object_opts = {
 413    .name = "object",
 414    .implied_opt_name = "qom-type",
 415    .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
 416    .desc = {
 417        { }
 418    },
 419};
 420
 421
 422
 423static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
 424{
 425    Object *obj;
 426    QCryptoTLSCreds *creds;
 427
 428    obj = object_resolve_path_component(
 429        object_get_objects_root(), id);
 430    if (!obj) {
 431        error_setg(errp, "No TLS credentials with id '%s'",
 432                   id);
 433        return NULL;
 434    }
 435    creds = (QCryptoTLSCreds *)
 436        object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 437    if (!creds) {
 438        error_setg(errp, "Object with id '%s' is not TLS credentials",
 439                   id);
 440        return NULL;
 441    }
 442
 443    if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
 444        error_setg(errp,
 445                   "Expecting TLS credentials with a server endpoint");
 446        return NULL;
 447    }
 448    object_ref(obj);
 449    return creds;
 450}
 451
 452
 453int main(int argc, char **argv)
 454{
 455    BlockBackend *blk;
 456    BlockDriverState *bs;
 457    off_t dev_offset = 0;
 458    uint32_t nbdflags = 0;
 459    bool disconnect = false;
 460    const char *bindto = "0.0.0.0";
 461    const char *port = NULL;
 462    char *sockpath = NULL;
 463    char *device = NULL;
 464    off_t fd_size;
 465    QemuOpts *sn_opts = NULL;
 466    const char *sn_id_or_name = NULL;
 467    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:";
 468    struct option lopt[] = {
 469        { "help", no_argument, NULL, 'h' },
 470        { "version", no_argument, NULL, 'V' },
 471        { "bind", required_argument, NULL, 'b' },
 472        { "port", required_argument, NULL, 'p' },
 473        { "socket", required_argument, NULL, 'k' },
 474        { "offset", required_argument, NULL, 'o' },
 475        { "read-only", no_argument, NULL, 'r' },
 476        { "partition", required_argument, NULL, 'P' },
 477        { "connect", required_argument, NULL, 'c' },
 478        { "disconnect", no_argument, NULL, 'd' },
 479        { "snapshot", no_argument, NULL, 's' },
 480        { "load-snapshot", required_argument, NULL, 'l' },
 481        { "nocache", no_argument, NULL, 'n' },
 482        { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
 483        { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
 484        { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
 485        { "detect-zeroes", required_argument, NULL,
 486          QEMU_NBD_OPT_DETECT_ZEROES },
 487        { "shared", required_argument, NULL, 'e' },
 488        { "format", required_argument, NULL, 'f' },
 489        { "persistent", no_argument, NULL, 't' },
 490        { "verbose", no_argument, NULL, 'v' },
 491        { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
 492        { "export-name", required_argument, NULL, 'x' },
 493        { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
 494        { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
 495        { NULL, 0, NULL, 0 }
 496    };
 497    int ch;
 498    int opt_ind = 0;
 499    char *end;
 500    int flags = BDRV_O_RDWR;
 501    int partition = -1;
 502    int ret = 0;
 503    bool seen_cache = false;
 504    bool seen_discard = false;
 505    bool seen_aio = false;
 506    pthread_t client_thread;
 507    const char *fmt = NULL;
 508    Error *local_err = NULL;
 509    BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
 510    QDict *options = NULL;
 511    const char *export_name = NULL;
 512    const char *tlscredsid = NULL;
 513    bool imageOpts = false;
 514    bool writethrough = true;
 515
 516    /* The client thread uses SIGTERM to interrupt the server.  A signal
 517     * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
 518     */
 519    struct sigaction sa_sigterm;
 520    memset(&sa_sigterm, 0, sizeof(sa_sigterm));
 521    sa_sigterm.sa_handler = termsig_handler;
 522    sigaction(SIGTERM, &sa_sigterm, NULL);
 523
 524    if (qcrypto_init(&local_err) < 0) {
 525        error_reportf_err(local_err, "cannot initialize crypto: ");
 526        exit(1);
 527    }
 528
 529    module_call_init(MODULE_INIT_QOM);
 530    qemu_add_opts(&qemu_object_opts);
 531    qemu_init_exec_dir(argv[0]);
 532
 533    while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 534        switch (ch) {
 535        case 's':
 536            flags |= BDRV_O_SNAPSHOT;
 537            break;
 538        case 'n':
 539            optarg = (char *) "none";
 540            /* fallthrough */
 541        case QEMU_NBD_OPT_CACHE:
 542            if (seen_cache) {
 543                error_report("-n and --cache can only be specified once");
 544                exit(EXIT_FAILURE);
 545            }
 546            seen_cache = true;
 547            if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
 548                error_report("Invalid cache mode `%s'", optarg);
 549                exit(EXIT_FAILURE);
 550            }
 551            break;
 552        case QEMU_NBD_OPT_AIO:
 553            if (seen_aio) {
 554                error_report("--aio can only be specified once");
 555                exit(EXIT_FAILURE);
 556            }
 557            seen_aio = true;
 558            if (!strcmp(optarg, "native")) {
 559                flags |= BDRV_O_NATIVE_AIO;
 560            } else if (!strcmp(optarg, "threads")) {
 561                /* this is the default */
 562            } else {
 563               error_report("invalid aio mode `%s'", optarg);
 564               exit(EXIT_FAILURE);
 565            }
 566            break;
 567        case QEMU_NBD_OPT_DISCARD:
 568            if (seen_discard) {
 569                error_report("--discard can only be specified once");
 570                exit(EXIT_FAILURE);
 571            }
 572            seen_discard = true;
 573            if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 574                error_report("Invalid discard mode `%s'", optarg);
 575                exit(EXIT_FAILURE);
 576            }
 577            break;
 578        case QEMU_NBD_OPT_DETECT_ZEROES:
 579            detect_zeroes =
 580                qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
 581                                optarg,
 582                                BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX,
 583                                BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
 584                                &local_err);
 585            if (local_err) {
 586                error_reportf_err(local_err,
 587                                  "Failed to parse detect_zeroes mode: ");
 588                exit(EXIT_FAILURE);
 589            }
 590            if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
 591                !(flags & BDRV_O_UNMAP)) {
 592                error_report("setting detect-zeroes to unmap is not allowed "
 593                             "without setting discard operation to unmap");
 594                exit(EXIT_FAILURE);
 595            }
 596            break;
 597        case 'b':
 598            bindto = optarg;
 599            break;
 600        case 'p':
 601            port = optarg;
 602            break;
 603        case 'o':
 604                dev_offset = strtoll (optarg, &end, 0);
 605            if (*end) {
 606                error_report("Invalid offset `%s'", optarg);
 607                exit(EXIT_FAILURE);
 608            }
 609            if (dev_offset < 0) {
 610                error_report("Offset must be positive `%s'", optarg);
 611                exit(EXIT_FAILURE);
 612            }
 613            break;
 614        case 'l':
 615            if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 616                sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
 617                                                  optarg, false);
 618                if (!sn_opts) {
 619                    error_report("Failed in parsing snapshot param `%s'",
 620                                 optarg);
 621                    exit(EXIT_FAILURE);
 622                }
 623            } else {
 624                sn_id_or_name = optarg;
 625            }
 626            /* fall through */
 627        case 'r':
 628            nbdflags |= NBD_FLAG_READ_ONLY;
 629            flags &= ~BDRV_O_RDWR;
 630            break;
 631        case 'P':
 632            partition = strtol(optarg, &end, 0);
 633            if (*end) {
 634                error_report("Invalid partition `%s'", optarg);
 635                exit(EXIT_FAILURE);
 636            }
 637            if (partition < 1 || partition > 8) {
 638                error_report("Invalid partition %d", partition);
 639                exit(EXIT_FAILURE);
 640            }
 641            break;
 642        case 'k':
 643            sockpath = optarg;
 644            if (sockpath[0] != '/') {
 645                error_report("socket path must be absolute");
 646                exit(EXIT_FAILURE);
 647            }
 648            break;
 649        case 'd':
 650            disconnect = true;
 651            break;
 652        case 'c':
 653            device = optarg;
 654            break;
 655        case 'e':
 656            shared = strtol(optarg, &end, 0);
 657            if (*end) {
 658                error_report("Invalid shared device number '%s'", optarg);
 659                exit(EXIT_FAILURE);
 660            }
 661            if (shared < 1) {
 662                error_report("Shared device number must be greater than 0");
 663                exit(EXIT_FAILURE);
 664            }
 665            break;
 666        case 'f':
 667            fmt = optarg;
 668            break;
 669        case 't':
 670            persistent = 1;
 671            break;
 672        case 'x':
 673            export_name = optarg;
 674            break;
 675        case 'v':
 676            verbose = 1;
 677            break;
 678        case 'V':
 679            version(argv[0]);
 680            exit(0);
 681            break;
 682        case 'h':
 683            usage(argv[0]);
 684            exit(0);
 685            break;
 686        case '?':
 687            error_report("Try `%s --help' for more information.", argv[0]);
 688            exit(EXIT_FAILURE);
 689        case QEMU_NBD_OPT_OBJECT: {
 690            QemuOpts *opts;
 691            opts = qemu_opts_parse_noisily(&qemu_object_opts,
 692                                           optarg, true);
 693            if (!opts) {
 694                exit(EXIT_FAILURE);
 695            }
 696        }   break;
 697        case QEMU_NBD_OPT_TLSCREDS:
 698            tlscredsid = optarg;
 699            break;
 700        case QEMU_NBD_OPT_IMAGE_OPTS:
 701            imageOpts = true;
 702            break;
 703        }
 704    }
 705
 706    if ((argc - optind) != 1) {
 707        error_report("Invalid number of arguments");
 708        error_printf("Try `%s --help' for more information.\n", argv[0]);
 709        exit(EXIT_FAILURE);
 710    }
 711
 712    if (qemu_opts_foreach(&qemu_object_opts,
 713                          user_creatable_add_opts_foreach,
 714                          NULL, NULL)) {
 715        exit(EXIT_FAILURE);
 716    }
 717
 718    if (tlscredsid) {
 719        if (sockpath) {
 720            error_report("TLS is only supported with IPv4/IPv6");
 721            exit(EXIT_FAILURE);
 722        }
 723        if (device) {
 724            error_report("TLS is not supported with a host device");
 725            exit(EXIT_FAILURE);
 726        }
 727        if (!export_name) {
 728            /* Set the default NBD protocol export name, since
 729             * we *must* use new style protocol for TLS */
 730            export_name = "";
 731        }
 732        tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);
 733        if (local_err) {
 734            error_report("Failed to get TLS creds %s",
 735                         error_get_pretty(local_err));
 736            exit(EXIT_FAILURE);
 737        }
 738    }
 739
 740    if (disconnect) {
 741        int nbdfd = open(argv[optind], O_RDWR);
 742        if (nbdfd < 0) {
 743            error_report("Cannot open %s: %s", argv[optind],
 744                         strerror(errno));
 745            exit(EXIT_FAILURE);
 746        }
 747        nbd_disconnect(nbdfd);
 748
 749        close(nbdfd);
 750
 751        printf("%s disconnected\n", argv[optind]);
 752
 753        return 0;
 754    }
 755
 756    if (device && !verbose) {
 757        int stderr_fd[2];
 758        pid_t pid;
 759        int ret;
 760
 761        if (qemu_pipe(stderr_fd) < 0) {
 762            error_report("Error setting up communication pipe: %s",
 763                         strerror(errno));
 764            exit(EXIT_FAILURE);
 765        }
 766
 767        /* Now daemonize, but keep a communication channel open to
 768         * print errors and exit with the proper status code.
 769         */
 770        pid = fork();
 771        if (pid < 0) {
 772            error_report("Failed to fork: %s", strerror(errno));
 773            exit(EXIT_FAILURE);
 774        } else if (pid == 0) {
 775            close(stderr_fd[0]);
 776            ret = qemu_daemon(1, 0);
 777
 778            /* Temporarily redirect stderr to the parent's pipe...  */
 779            dup2(stderr_fd[1], STDERR_FILENO);
 780            if (ret < 0) {
 781                error_report("Failed to daemonize: %s", strerror(errno));
 782                exit(EXIT_FAILURE);
 783            }
 784
 785            /* ... close the descriptor we inherited and go on.  */
 786            close(stderr_fd[1]);
 787        } else {
 788            bool errors = false;
 789            char *buf;
 790
 791            /* In the parent.  Print error messages from the child until
 792             * it closes the pipe.
 793             */
 794            close(stderr_fd[1]);
 795            buf = g_malloc(1024);
 796            while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
 797                errors = true;
 798                ret = qemu_write_full(STDERR_FILENO, buf, ret);
 799                if (ret < 0) {
 800                    exit(EXIT_FAILURE);
 801                }
 802            }
 803            if (ret < 0) {
 804                error_report("Cannot read from daemon: %s",
 805                             strerror(errno));
 806                exit(EXIT_FAILURE);
 807            }
 808
 809            /* Usually the daemon should not print any message.
 810             * Exit with zero status in that case.
 811             */
 812            exit(errors);
 813        }
 814    }
 815
 816    if (device != NULL && sockpath == NULL) {
 817        sockpath = g_malloc(128);
 818        snprintf(sockpath, 128, SOCKET_PATH, basename(device));
 819    }
 820
 821    saddr = nbd_build_socket_address(sockpath, bindto, port);
 822
 823    if (qemu_init_main_loop(&local_err)) {
 824        error_report_err(local_err);
 825        exit(EXIT_FAILURE);
 826    }
 827    bdrv_init();
 828    atexit(bdrv_close_all);
 829
 830    srcpath = argv[optind];
 831    if (imageOpts) {
 832        QemuOpts *opts;
 833        if (fmt) {
 834            error_report("--image-opts and -f are mutually exclusive");
 835            exit(EXIT_FAILURE);
 836        }
 837        opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
 838        if (!opts) {
 839            qemu_opts_reset(&file_opts);
 840            exit(EXIT_FAILURE);
 841        }
 842        options = qemu_opts_to_qdict(opts, NULL);
 843        qemu_opts_reset(&file_opts);
 844        blk = blk_new_open(NULL, NULL, options, flags, &local_err);
 845    } else {
 846        if (fmt) {
 847            options = qdict_new();
 848            qdict_put(options, "driver", qstring_from_str(fmt));
 849        }
 850        blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
 851    }
 852
 853    if (!blk) {
 854        error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
 855                          argv[optind]);
 856        exit(EXIT_FAILURE);
 857    }
 858    bs = blk_bs(blk);
 859
 860    blk_set_enable_write_cache(blk, !writethrough);
 861
 862    if (sn_opts) {
 863        ret = bdrv_snapshot_load_tmp(bs,
 864                                     qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
 865                                     qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
 866                                     &local_err);
 867    } else if (sn_id_or_name) {
 868        ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
 869                                                   &local_err);
 870    }
 871    if (ret < 0) {
 872        error_reportf_err(local_err, "Failed to load snapshot: ");
 873        exit(EXIT_FAILURE);
 874    }
 875
 876    bs->detect_zeroes = detect_zeroes;
 877    fd_size = blk_getlength(blk);
 878    if (fd_size < 0) {
 879        error_report("Failed to determine the image length: %s",
 880                     strerror(-fd_size));
 881        exit(EXIT_FAILURE);
 882    }
 883
 884    if (partition != -1) {
 885        ret = find_partition(blk, partition, &dev_offset, &fd_size);
 886        if (ret < 0) {
 887            error_report("Could not find partition %d: %s", partition,
 888                         strerror(-ret));
 889            exit(EXIT_FAILURE);
 890        }
 891    }
 892
 893    exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed,
 894                         &local_err);
 895    if (!exp) {
 896        error_report_err(local_err);
 897        exit(EXIT_FAILURE);
 898    }
 899    if (export_name) {
 900        nbd_export_set_name(exp, export_name);
 901        newproto = true;
 902    }
 903
 904    server_ioc = qio_channel_socket_new();
 905    if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) {
 906        object_unref(OBJECT(server_ioc));
 907        error_report_err(local_err);
 908        return 1;
 909    }
 910
 911    if (device) {
 912        int ret;
 913
 914        ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
 915        if (ret != 0) {
 916            error_report("Failed to create client thread: %s", strerror(ret));
 917            exit(EXIT_FAILURE);
 918        }
 919    } else {
 920        /* Shut up GCC warnings.  */
 921        memset(&client_thread, 0, sizeof(client_thread));
 922    }
 923
 924    nbd_update_server_watch();
 925
 926    /* now when the initialization is (almost) complete, chdir("/")
 927     * to free any busy filesystems */
 928    if (chdir("/") < 0) {
 929        error_report("Could not chdir to root directory: %s",
 930                     strerror(errno));
 931        exit(EXIT_FAILURE);
 932    }
 933
 934    state = RUNNING;
 935    do {
 936        main_loop_wait(false);
 937        if (state == TERMINATE) {
 938            state = TERMINATING;
 939            nbd_export_close(exp);
 940            nbd_export_put(exp);
 941            exp = NULL;
 942        }
 943    } while (state != TERMINATED);
 944
 945    blk_unref(blk);
 946    if (sockpath) {
 947        unlink(sockpath);
 948    }
 949
 950    qemu_opts_del(sn_opts);
 951
 952    if (device) {
 953        void *ret;
 954        pthread_join(client_thread, &ret);
 955        exit(ret != NULL);
 956    } else {
 957        exit(EXIT_SUCCESS);
 958    }
 959}
 960