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 <getopt.h>
  21#include <libgen.h>
  22#include <pthread.h>
  23
  24#include "qemu-common.h"
  25#include "qapi/error.h"
  26#include "qemu/cutils.h"
  27#include "sysemu/block-backend.h"
  28#include "sysemu/runstate.h" /* for qemu_system_killed() prototype */
  29#include "block/block_int.h"
  30#include "block/nbd.h"
  31#include "qemu/main-loop.h"
  32#include "qemu/module.h"
  33#include "qemu/option.h"
  34#include "qemu/error-report.h"
  35#include "qemu/config-file.h"
  36#include "qemu/bswap.h"
  37#include "qemu/log.h"
  38#include "qemu/systemd.h"
  39#include "block/snapshot.h"
  40#include "qapi/qmp/qdict.h"
  41#include "qapi/qmp/qstring.h"
  42#include "qom/object_interfaces.h"
  43#include "io/channel-socket.h"
  44#include "io/net-listener.h"
  45#include "crypto/init.h"
  46#include "crypto/tlscreds.h"
  47#include "trace/control.h"
  48#include "qemu-version.h"
  49
  50#ifdef CONFIG_SELINUX
  51#include <selinux/selinux.h>
  52#endif
  53
  54#ifdef __linux__
  55#define HAVE_NBD_DEVICE 1
  56#else
  57#define HAVE_NBD_DEVICE 0
  58#endif
  59
  60#define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
  61#define QEMU_NBD_OPT_CACHE         256
  62#define QEMU_NBD_OPT_AIO           257
  63#define QEMU_NBD_OPT_DISCARD       258
  64#define QEMU_NBD_OPT_DETECT_ZEROES 259
  65#define QEMU_NBD_OPT_OBJECT        260
  66#define QEMU_NBD_OPT_TLSCREDS      261
  67#define QEMU_NBD_OPT_IMAGE_OPTS    262
  68#define QEMU_NBD_OPT_FORK          263
  69#define QEMU_NBD_OPT_TLSAUTHZ      264
  70#define QEMU_NBD_OPT_PID_FILE      265
  71#define QEMU_NBD_OPT_SELINUX_LABEL 266
  72
  73#define MBR_SIZE 512
  74
  75static int verbose;
  76static char *srcpath;
  77static SocketAddress *saddr;
  78static int persistent = 0;
  79static enum { RUNNING, TERMINATE, TERMINATED } state;
  80static int shared = 1;
  81static int nb_fds;
  82static QIONetListener *server;
  83static QCryptoTLSCreds *tlscreds;
  84static const char *tlsauthz;
  85
  86static void usage(const char *name)
  87{
  88    (printf) (
  89"Usage: %s [OPTIONS] FILE\n"
  90"  or:  %s -L [OPTIONS]\n"
  91"QEMU Disk Network Block Device Utility\n"
  92"\n"
  93"  -h, --help                display this help and exit\n"
  94"  -V, --version             output version information and exit\n"
  95"\n"
  96"Connection properties:\n"
  97"  -p, --port=PORT           port to listen on (default `%d')\n"
  98"  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
  99"  -k, --socket=PATH         path to the unix socket\n"
 100"                            (default '"SOCKET_PATH"')\n"
 101"  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
 102"  -t, --persistent          don't exit on the last connection\n"
 103"  -v, --verbose             display extra debugging information\n"
 104"  -x, --export-name=NAME    expose export by name (default is empty string)\n"
 105"  -D, --description=TEXT    export a human-readable description\n"
 106"\n"
 107"Exposing part of the image:\n"
 108"  -o, --offset=OFFSET       offset into the image\n"
 109"  -A, --allocation-depth    expose the allocation depth\n"
 110"  -B, --bitmap=NAME         expose a persistent dirty bitmap\n"
 111"\n"
 112"General purpose options:\n"
 113"  -L, --list                list exports available from another NBD server\n"
 114"  --object type,id=ID,...   define an object such as 'secret' for providing\n"
 115"                            passwords and/or encryption keys\n"
 116"  --tls-creds=ID            use id of an earlier --object to provide TLS\n"
 117"  --tls-authz=ID            use id of an earlier --object to provide\n"
 118"                            authorization\n"
 119"  -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
 120"                            specify tracing options\n"
 121"  --fork                    fork off the server process and exit the parent\n"
 122"                            once the server is running\n"
 123"  --pid-file=PATH           store the server's process ID in the given file\n"
 124#ifdef CONFIG_SELINUX
 125"  --selinux-label=LABEL     set SELinux process label on listening socket\n"
 126#endif
 127#if HAVE_NBD_DEVICE
 128"\n"
 129"Kernel NBD client support:\n"
 130"  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
 131"  -d, --disconnect          disconnect the specified device\n"
 132#endif
 133"\n"
 134"Block device options:\n"
 135"  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
 136"  -r, --read-only           export read-only\n"
 137"  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
 138"                            file with backing_file=FILE, redirect the write to\n"
 139"                            the temporary one\n"
 140"  -l, --load-snapshot=SNAPSHOT_PARAM\n"
 141"                            load an internal snapshot inside FILE and export it\n"
 142"                            as an read-only device, SNAPSHOT_PARAM format is\n"
 143"                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
 144"                            '[ID_OR_NAME]'\n"
 145"  -n, --nocache             disable host cache\n"
 146"      --cache=MODE          set cache mode used to access the disk image, the\n"
 147"                            valid options are: 'none', 'writeback' (default),\n"
 148"                            'writethrough', 'directsync' and 'unsafe'\n"
 149"      --aio=MODE            set AIO mode (native, io_uring or threads)\n"
 150"      --discard=MODE        set discard mode (ignore, unmap)\n"
 151"      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
 152"      --image-opts          treat FILE as a full set of image options\n"
 153"\n"
 154QEMU_HELP_BOTTOM "\n"
 155    , name, name, NBD_DEFAULT_PORT, "DEVICE");
 156}
 157
 158static void version(const char *name)
 159{
 160    printf(
 161"%s " QEMU_FULL_VERSION "\n"
 162"Written by Anthony Liguori.\n"
 163"\n"
 164QEMU_COPYRIGHT "\n"
 165"This is free software; see the source for copying conditions.  There is NO\n"
 166"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
 167    , name);
 168}
 169
 170#ifdef CONFIG_POSIX
 171/*
 172 * The client thread uses SIGTERM to interrupt the server.  A signal
 173 * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
 174 */
 175void qemu_system_killed(int signum, pid_t pid)
 176{
 177    qatomic_cmpxchg(&state, RUNNING, TERMINATE);
 178    qemu_notify_event();
 179}
 180#endif /* CONFIG_POSIX */
 181
 182static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
 183                                const char *hostname)
 184{
 185    int ret = EXIT_FAILURE;
 186    int rc;
 187    Error *err = NULL;
 188    QIOChannelSocket *sioc;
 189    NBDExportInfo *list;
 190    int i, j;
 191
 192    sioc = qio_channel_socket_new();
 193    if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
 194        error_report_err(err);
 195        goto out;
 196    }
 197    rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
 198                                 &err);
 199    if (rc < 0) {
 200        if (err) {
 201            error_report_err(err);
 202        }
 203        goto out;
 204    }
 205    printf("exports available: %d\n", rc);
 206    for (i = 0; i < rc; i++) {
 207        printf(" export: '%s'\n", list[i].name);
 208        if (list[i].description && *list[i].description) {
 209            printf("  description: %s\n", list[i].description);
 210        }
 211        if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
 212            static const char *const flag_names[] = {
 213                [NBD_FLAG_READ_ONLY_BIT]            = "readonly",
 214                [NBD_FLAG_SEND_FLUSH_BIT]           = "flush",
 215                [NBD_FLAG_SEND_FUA_BIT]             = "fua",
 216                [NBD_FLAG_ROTATIONAL_BIT]           = "rotational",
 217                [NBD_FLAG_SEND_TRIM_BIT]            = "trim",
 218                [NBD_FLAG_SEND_WRITE_ZEROES_BIT]    = "zeroes",
 219                [NBD_FLAG_SEND_DF_BIT]              = "df",
 220                [NBD_FLAG_CAN_MULTI_CONN_BIT]       = "multi",
 221                [NBD_FLAG_SEND_RESIZE_BIT]          = "resize",
 222                [NBD_FLAG_SEND_CACHE_BIT]           = "cache",
 223                [NBD_FLAG_SEND_FAST_ZERO_BIT]       = "fast-zero",
 224            };
 225
 226            printf("  size:  %" PRIu64 "\n", list[i].size);
 227            printf("  flags: 0x%x (", list[i].flags);
 228            for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) {
 229                if (flag_names[bit] && (list[i].flags & (1 << bit))) {
 230                    printf(" %s", flag_names[bit]);
 231                }
 232            }
 233            printf(" )\n");
 234        }
 235        if (list[i].min_block) {
 236            printf("  min block: %u\n", list[i].min_block);
 237            printf("  opt block: %u\n", list[i].opt_block);
 238            printf("  max block: %u\n", list[i].max_block);
 239        }
 240        if (list[i].n_contexts) {
 241            printf("  available meta contexts: %d\n", list[i].n_contexts);
 242            for (j = 0; j < list[i].n_contexts; j++) {
 243                printf("   %s\n", list[i].contexts[j]);
 244            }
 245        }
 246    }
 247    nbd_free_export_list(list, rc);
 248
 249    ret = EXIT_SUCCESS;
 250 out:
 251    object_unref(OBJECT(sioc));
 252    return ret;
 253}
 254
 255
 256#if HAVE_NBD_DEVICE
 257static void *show_parts(void *arg)
 258{
 259    char *device = arg;
 260    int nbd;
 261
 262    /* linux just needs an open() to trigger
 263     * the partition table update
 264     * but remember to load the module with max_part != 0 :
 265     *     modprobe nbd max_part=63
 266     */
 267    nbd = open(device, O_RDWR);
 268    if (nbd >= 0) {
 269        close(nbd);
 270    }
 271    return NULL;
 272}
 273
 274static void *nbd_client_thread(void *arg)
 275{
 276    char *device = arg;
 277    NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };
 278    QIOChannelSocket *sioc;
 279    int fd = -1;
 280    int ret = EXIT_FAILURE;
 281    pthread_t show_parts_thread;
 282    Error *local_error = NULL;
 283
 284    sioc = qio_channel_socket_new();
 285    if (qio_channel_socket_connect_sync(sioc,
 286                                        saddr,
 287                                        &local_error) < 0) {
 288        error_report_err(local_error);
 289        goto out;
 290    }
 291
 292    if (nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc),
 293                              NULL, NULL, NULL, &info, &local_error) < 0) {
 294        if (local_error) {
 295            error_report_err(local_error);
 296        }
 297        goto out;
 298    }
 299
 300    fd = open(device, O_RDWR);
 301    if (fd < 0) {
 302        /* Linux-only, we can use %m in printf.  */
 303        error_report("Failed to open %s: %m", device);
 304        goto out;
 305    }
 306
 307    if (nbd_init(fd, sioc, &info, &local_error) < 0) {
 308        error_report_err(local_error);
 309        goto out;
 310    }
 311
 312    /* update partition table */
 313    pthread_create(&show_parts_thread, NULL, show_parts, device);
 314
 315    if (verbose) {
 316        fprintf(stderr, "NBD device %s is now connected to %s\n",
 317                device, srcpath);
 318    } else {
 319        /* Close stderr so that the qemu-nbd process exits.  */
 320        dup2(STDOUT_FILENO, STDERR_FILENO);
 321    }
 322
 323    if (nbd_client(fd) < 0) {
 324        goto out;
 325    }
 326
 327    ret = EXIT_SUCCESS;
 328
 329 out:
 330    if (fd >= 0) {
 331        close(fd);
 332    }
 333    object_unref(OBJECT(sioc));
 334    g_free(info.name);
 335    kill(getpid(), SIGTERM);
 336    return (void *) (intptr_t) ret;
 337}
 338#endif /* HAVE_NBD_DEVICE */
 339
 340static int nbd_can_accept(void)
 341{
 342    return state == RUNNING && (shared == 0 || nb_fds < shared);
 343}
 344
 345static void nbd_update_server_watch(void);
 346
 347static void nbd_client_closed(NBDClient *client, bool negotiated)
 348{
 349    nb_fds--;
 350    if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
 351        state = TERMINATE;
 352    }
 353    nbd_update_server_watch();
 354    nbd_client_put(client);
 355}
 356
 357static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
 358                       gpointer opaque)
 359{
 360    if (state >= TERMINATE) {
 361        return;
 362    }
 363
 364    nb_fds++;
 365    nbd_update_server_watch();
 366    nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
 367}
 368
 369static void nbd_update_server_watch(void)
 370{
 371    if (nbd_can_accept()) {
 372        qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
 373    } else {
 374        qio_net_listener_set_client_func(server, NULL, NULL, NULL);
 375    }
 376}
 377
 378
 379static SocketAddress *nbd_build_socket_address(const char *sockpath,
 380                                               const char *bindto,
 381                                               const char *port)
 382{
 383    SocketAddress *saddr;
 384
 385    saddr = g_new0(SocketAddress, 1);
 386    if (sockpath) {
 387        saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
 388        saddr->u.q_unix.path = g_strdup(sockpath);
 389    } else {
 390        InetSocketAddress *inet;
 391        saddr->type = SOCKET_ADDRESS_TYPE_INET;
 392        inet = &saddr->u.inet;
 393        inet->host = g_strdup(bindto);
 394        if (port) {
 395            inet->port = g_strdup(port);
 396        } else  {
 397            inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 398        }
 399    }
 400
 401    return saddr;
 402}
 403
 404
 405static QemuOptsList file_opts = {
 406    .name = "file",
 407    .implied_opt_name = "file",
 408    .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
 409    .desc = {
 410        /* no elements => accept any params */
 411        { /* end of list */ }
 412    },
 413};
 414
 415static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
 416                                          Error **errp)
 417{
 418    Object *obj;
 419    QCryptoTLSCreds *creds;
 420
 421    obj = object_resolve_path_component(
 422        object_get_objects_root(), id);
 423    if (!obj) {
 424        error_setg(errp, "No TLS credentials with id '%s'",
 425                   id);
 426        return NULL;
 427    }
 428    creds = (QCryptoTLSCreds *)
 429        object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 430    if (!creds) {
 431        error_setg(errp, "Object with id '%s' is not TLS credentials",
 432                   id);
 433        return NULL;
 434    }
 435
 436    if (!qcrypto_tls_creds_check_endpoint(creds,
 437                                          list
 438                                          ? QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT
 439                                          : QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
 440                                          errp)) {
 441        return NULL;
 442    }
 443    object_ref(obj);
 444    return creds;
 445}
 446
 447static void setup_address_and_port(const char **address, const char **port)
 448{
 449    if (*address == NULL) {
 450        *address = "0.0.0.0";
 451    }
 452
 453    if (*port == NULL) {
 454        *port = stringify(NBD_DEFAULT_PORT);
 455    }
 456}
 457
 458/*
 459 * Check socket parameters compatibility when socket activation is used.
 460 */
 461static const char *socket_activation_validate_opts(const char *device,
 462                                                   const char *sockpath,
 463                                                   const char *address,
 464                                                   const char *port,
 465                                                   const char *selinux,
 466                                                   bool list)
 467{
 468    if (device != NULL) {
 469        return "NBD device can't be set when using socket activation";
 470    }
 471
 472    if (sockpath != NULL) {
 473        return "Unix socket can't be set when using socket activation";
 474    }
 475
 476    if (address != NULL) {
 477        return "The interface can't be set when using socket activation";
 478    }
 479
 480    if (port != NULL) {
 481        return "TCP port number can't be set when using socket activation";
 482    }
 483
 484    if (selinux != NULL) {
 485        return "SELinux label can't be set when using socket activation";
 486    }
 487
 488    if (list) {
 489        return "List mode is incompatible with socket activation";
 490    }
 491
 492    return NULL;
 493}
 494
 495static void qemu_nbd_shutdown(void)
 496{
 497    job_cancel_sync_all();
 498    blk_exp_close_all();
 499    bdrv_close_all();
 500}
 501
 502int main(int argc, char **argv)
 503{
 504    BlockBackend *blk;
 505    BlockDriverState *bs;
 506    uint64_t dev_offset = 0;
 507    bool readonly = false;
 508    bool disconnect = false;
 509    const char *bindto = NULL;
 510    const char *port = NULL;
 511    char *sockpath = NULL;
 512    char *device = NULL;
 513    QemuOpts *sn_opts = NULL;
 514    const char *sn_id_or_name = NULL;
 515    const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:AB:L";
 516    struct option lopt[] = {
 517        { "help", no_argument, NULL, 'h' },
 518        { "version", no_argument, NULL, 'V' },
 519        { "bind", required_argument, NULL, 'b' },
 520        { "port", required_argument, NULL, 'p' },
 521        { "socket", required_argument, NULL, 'k' },
 522        { "offset", required_argument, NULL, 'o' },
 523        { "read-only", no_argument, NULL, 'r' },
 524        { "allocation-depth", no_argument, NULL, 'A' },
 525        { "bitmap", required_argument, NULL, 'B' },
 526        { "connect", required_argument, NULL, 'c' },
 527        { "disconnect", no_argument, NULL, 'd' },
 528        { "list", no_argument, NULL, 'L' },
 529        { "snapshot", no_argument, NULL, 's' },
 530        { "load-snapshot", required_argument, NULL, 'l' },
 531        { "nocache", no_argument, NULL, 'n' },
 532        { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
 533        { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
 534        { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
 535        { "detect-zeroes", required_argument, NULL,
 536          QEMU_NBD_OPT_DETECT_ZEROES },
 537        { "shared", required_argument, NULL, 'e' },
 538        { "format", required_argument, NULL, 'f' },
 539        { "persistent", no_argument, NULL, 't' },
 540        { "verbose", no_argument, NULL, 'v' },
 541        { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
 542        { "export-name", required_argument, NULL, 'x' },
 543        { "description", required_argument, NULL, 'D' },
 544        { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
 545        { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
 546        { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
 547        { "trace", required_argument, NULL, 'T' },
 548        { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
 549        { "pid-file", required_argument, NULL, QEMU_NBD_OPT_PID_FILE },
 550        { "selinux-label", required_argument, NULL,
 551          QEMU_NBD_OPT_SELINUX_LABEL },
 552        { NULL, 0, NULL, 0 }
 553    };
 554    int ch;
 555    int opt_ind = 0;
 556    int flags = BDRV_O_RDWR;
 557    int ret = 0;
 558    bool seen_cache = false;
 559    bool seen_discard = false;
 560    bool seen_aio = false;
 561    pthread_t client_thread;
 562    const char *fmt = NULL;
 563    Error *local_err = NULL;
 564    BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
 565    QDict *options = NULL;
 566    const char *export_name = NULL; /* defaults to "" later for server mode */
 567    const char *export_description = NULL;
 568    strList *bitmaps = NULL;
 569    bool alloc_depth = false;
 570    const char *tlscredsid = NULL;
 571    bool imageOpts = false;
 572    bool writethrough = false; /* Client will flush as needed. */
 573    bool fork_process = false;
 574    bool list = false;
 575    int old_stderr = -1;
 576    unsigned socket_activation;
 577    const char *pid_file_name = NULL;
 578    const char *selinux_label = NULL;
 579    BlockExportOptions *export_opts;
 580
 581#ifdef CONFIG_POSIX
 582    os_setup_early_signal_handling();
 583    os_setup_signal_handling();
 584#endif
 585
 586    socket_init();
 587    error_init(argv[0]);
 588    module_call_init(MODULE_INIT_TRACE);
 589    qcrypto_init(&error_fatal);
 590
 591    module_call_init(MODULE_INIT_QOM);
 592    qemu_add_opts(&qemu_trace_opts);
 593    qemu_init_exec_dir(argv[0]);
 594
 595    while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 596        switch (ch) {
 597        case 's':
 598            flags |= BDRV_O_SNAPSHOT;
 599            break;
 600        case 'n':
 601            optarg = (char *) "none";
 602            /* fallthrough */
 603        case QEMU_NBD_OPT_CACHE:
 604            if (seen_cache) {
 605                error_report("-n and --cache can only be specified once");
 606                exit(EXIT_FAILURE);
 607            }
 608            seen_cache = true;
 609            if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
 610                error_report("Invalid cache mode `%s'", optarg);
 611                exit(EXIT_FAILURE);
 612            }
 613            break;
 614        case QEMU_NBD_OPT_AIO:
 615            if (seen_aio) {
 616                error_report("--aio can only be specified once");
 617                exit(EXIT_FAILURE);
 618            }
 619            seen_aio = true;
 620            if (bdrv_parse_aio(optarg, &flags) < 0) {
 621                error_report("Invalid aio mode '%s'", optarg);
 622                exit(EXIT_FAILURE);
 623            }
 624            break;
 625        case QEMU_NBD_OPT_DISCARD:
 626            if (seen_discard) {
 627                error_report("--discard can only be specified once");
 628                exit(EXIT_FAILURE);
 629            }
 630            seen_discard = true;
 631            if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 632                error_report("Invalid discard mode `%s'", optarg);
 633                exit(EXIT_FAILURE);
 634            }
 635            break;
 636        case QEMU_NBD_OPT_DETECT_ZEROES:
 637            detect_zeroes =
 638                qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
 639                                optarg,
 640                                BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
 641                                &local_err);
 642            if (local_err) {
 643                error_reportf_err(local_err,
 644                                  "Failed to parse detect_zeroes mode: ");
 645                exit(EXIT_FAILURE);
 646            }
 647            if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
 648                !(flags & BDRV_O_UNMAP)) {
 649                error_report("setting detect-zeroes to unmap is not allowed "
 650                             "without setting discard operation to unmap");
 651                exit(EXIT_FAILURE);
 652            }
 653            break;
 654        case 'b':
 655            bindto = optarg;
 656            break;
 657        case 'p':
 658            port = optarg;
 659            break;
 660        case 'o':
 661            if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
 662                error_report("Invalid offset '%s'", optarg);
 663                exit(EXIT_FAILURE);
 664            }
 665            break;
 666        case 'l':
 667            if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 668                sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
 669                                                  optarg, false);
 670                if (!sn_opts) {
 671                    error_report("Failed in parsing snapshot param `%s'",
 672                                 optarg);
 673                    exit(EXIT_FAILURE);
 674                }
 675            } else {
 676                sn_id_or_name = optarg;
 677            }
 678            /* fall through */
 679        case 'r':
 680            readonly = true;
 681            flags &= ~BDRV_O_RDWR;
 682            break;
 683        case 'A':
 684            alloc_depth = true;
 685            break;
 686        case 'B':
 687            QAPI_LIST_PREPEND(bitmaps, g_strdup(optarg));
 688            break;
 689        case 'k':
 690            sockpath = optarg;
 691            if (sockpath[0] != '/') {
 692                error_report("socket path must be absolute");
 693                exit(EXIT_FAILURE);
 694            }
 695            break;
 696        case 'd':
 697            disconnect = true;
 698            break;
 699        case 'c':
 700            device = optarg;
 701            break;
 702        case 'e':
 703            if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
 704                shared < 0) {
 705                error_report("Invalid shared device number '%s'", optarg);
 706                exit(EXIT_FAILURE);
 707            }
 708            break;
 709        case 'f':
 710            fmt = optarg;
 711            break;
 712        case 't':
 713            persistent = 1;
 714            break;
 715        case 'x':
 716            export_name = optarg;
 717            if (strlen(export_name) > NBD_MAX_STRING_SIZE) {
 718                error_report("export name '%s' too long", export_name);
 719                exit(EXIT_FAILURE);
 720            }
 721            break;
 722        case 'D':
 723            export_description = optarg;
 724            if (strlen(export_description) > NBD_MAX_STRING_SIZE) {
 725                error_report("export description '%s' too long",
 726                             export_description);
 727                exit(EXIT_FAILURE);
 728            }
 729            break;
 730        case 'v':
 731            verbose = 1;
 732            break;
 733        case 'V':
 734            version(argv[0]);
 735            exit(0);
 736            break;
 737        case 'h':
 738            usage(argv[0]);
 739            exit(0);
 740            break;
 741        case '?':
 742            error_report("Try `%s --help' for more information.", argv[0]);
 743            exit(EXIT_FAILURE);
 744        case QEMU_NBD_OPT_OBJECT:
 745            user_creatable_process_cmdline(optarg);
 746            break;
 747        case QEMU_NBD_OPT_TLSCREDS:
 748            tlscredsid = optarg;
 749            break;
 750        case QEMU_NBD_OPT_IMAGE_OPTS:
 751            imageOpts = true;
 752            break;
 753        case 'T':
 754            trace_opt_parse(optarg);
 755            break;
 756        case QEMU_NBD_OPT_TLSAUTHZ:
 757            tlsauthz = optarg;
 758            break;
 759        case QEMU_NBD_OPT_FORK:
 760            fork_process = true;
 761            break;
 762        case 'L':
 763            list = true;
 764            break;
 765        case QEMU_NBD_OPT_PID_FILE:
 766            pid_file_name = optarg;
 767            break;
 768        case QEMU_NBD_OPT_SELINUX_LABEL:
 769            selinux_label = optarg;
 770            break;
 771        }
 772    }
 773
 774    if (list) {
 775        if (argc != optind) {
 776            error_report("List mode is incompatible with a file name");
 777            exit(EXIT_FAILURE);
 778        }
 779        if (export_name || export_description || dev_offset ||
 780            device || disconnect || fmt || sn_id_or_name || bitmaps ||
 781            alloc_depth || seen_aio || seen_discard || seen_cache) {
 782            error_report("List mode is incompatible with per-device settings");
 783            exit(EXIT_FAILURE);
 784        }
 785        if (fork_process) {
 786            error_report("List mode is incompatible with forking");
 787            exit(EXIT_FAILURE);
 788        }
 789    } else if ((argc - optind) != 1) {
 790        error_report("Invalid number of arguments");
 791        error_printf("Try `%s --help' for more information.\n", argv[0]);
 792        exit(EXIT_FAILURE);
 793    } else if (!export_name) {
 794        export_name = "";
 795    }
 796
 797    if (!trace_init_backends()) {
 798        exit(1);
 799    }
 800    trace_init_file();
 801    qemu_set_log(LOG_TRACE);
 802
 803    socket_activation = check_socket_activation();
 804    if (socket_activation == 0) {
 805        setup_address_and_port(&bindto, &port);
 806    } else {
 807        /* Using socket activation - check user didn't use -p etc. */
 808        const char *err_msg = socket_activation_validate_opts(device, sockpath,
 809                                                              bindto, port,
 810                                                              selinux_label,
 811                                                              list);
 812        if (err_msg != NULL) {
 813            error_report("%s", err_msg);
 814            exit(EXIT_FAILURE);
 815        }
 816
 817        /* qemu-nbd can only listen on a single socket.  */
 818        if (socket_activation > 1) {
 819            error_report("qemu-nbd does not support socket activation with %s > 1",
 820                         "LISTEN_FDS");
 821            exit(EXIT_FAILURE);
 822        }
 823    }
 824
 825    if (tlscredsid) {
 826        if (sockpath) {
 827            error_report("TLS is only supported with IPv4/IPv6");
 828            exit(EXIT_FAILURE);
 829        }
 830        if (device) {
 831            error_report("TLS is not supported with a host device");
 832            exit(EXIT_FAILURE);
 833        }
 834        if (tlsauthz && list) {
 835            error_report("TLS authorization is incompatible with export list");
 836            exit(EXIT_FAILURE);
 837        }
 838        tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
 839        if (local_err) {
 840            error_reportf_err(local_err, "Failed to get TLS creds: ");
 841            exit(EXIT_FAILURE);
 842        }
 843    } else {
 844        if (tlsauthz) {
 845            error_report("--tls-authz is not permitted without --tls-creds");
 846            exit(EXIT_FAILURE);
 847        }
 848    }
 849
 850    if (selinux_label) {
 851#ifdef CONFIG_SELINUX
 852        if (sockpath == NULL && device == NULL) {
 853            error_report("--selinux-label is not permitted without --socket");
 854            exit(EXIT_FAILURE);
 855        }
 856#else
 857        error_report("SELinux support not enabled in this binary");
 858        exit(EXIT_FAILURE);
 859#endif
 860    }
 861
 862    if (list) {
 863        saddr = nbd_build_socket_address(sockpath, bindto, port);
 864        return qemu_nbd_client_list(saddr, tlscreds, bindto);
 865    }
 866
 867#if !HAVE_NBD_DEVICE
 868    if (disconnect || device) {
 869        error_report("Kernel /dev/nbdN support not available");
 870        exit(EXIT_FAILURE);
 871    }
 872#else /* HAVE_NBD_DEVICE */
 873    if (disconnect) {
 874        int nbdfd = open(argv[optind], O_RDWR);
 875        if (nbdfd < 0) {
 876            error_report("Cannot open %s: %s", argv[optind],
 877                         strerror(errno));
 878            exit(EXIT_FAILURE);
 879        }
 880        nbd_disconnect(nbdfd);
 881
 882        close(nbdfd);
 883
 884        printf("%s disconnected\n", argv[optind]);
 885
 886        return 0;
 887    }
 888#endif
 889
 890    if ((device && !verbose) || fork_process) {
 891#ifndef WIN32
 892        int stderr_fd[2];
 893        pid_t pid;
 894        int ret;
 895
 896        if (qemu_pipe(stderr_fd) < 0) {
 897            error_report("Error setting up communication pipe: %s",
 898                         strerror(errno));
 899            exit(EXIT_FAILURE);
 900        }
 901
 902        /* Now daemonize, but keep a communication channel open to
 903         * print errors and exit with the proper status code.
 904         */
 905        pid = fork();
 906        if (pid < 0) {
 907            error_report("Failed to fork: %s", strerror(errno));
 908            exit(EXIT_FAILURE);
 909        } else if (pid == 0) {
 910            close(stderr_fd[0]);
 911
 912            /* Remember parent's stderr if we will be restoring it. */
 913            if (fork_process) {
 914                old_stderr = dup(STDERR_FILENO);
 915            }
 916
 917            ret = qemu_daemon(1, 0);
 918
 919            /* Temporarily redirect stderr to the parent's pipe...  */
 920            dup2(stderr_fd[1], STDERR_FILENO);
 921            if (ret < 0) {
 922                error_report("Failed to daemonize: %s", strerror(errno));
 923                exit(EXIT_FAILURE);
 924            }
 925
 926            /* ... close the descriptor we inherited and go on.  */
 927            close(stderr_fd[1]);
 928        } else {
 929            bool errors = false;
 930            char *buf;
 931
 932            /* In the parent.  Print error messages from the child until
 933             * it closes the pipe.
 934             */
 935            close(stderr_fd[1]);
 936            buf = g_malloc(1024);
 937            while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
 938                errors = true;
 939                ret = qemu_write_full(STDERR_FILENO, buf, ret);
 940                if (ret < 0) {
 941                    exit(EXIT_FAILURE);
 942                }
 943            }
 944            if (ret < 0) {
 945                error_report("Cannot read from daemon: %s",
 946                             strerror(errno));
 947                exit(EXIT_FAILURE);
 948            }
 949
 950            /* Usually the daemon should not print any message.
 951             * Exit with zero status in that case.
 952             */
 953            exit(errors);
 954        }
 955#else /* WIN32 */
 956        error_report("Unable to fork into background on Windows hosts");
 957        exit(EXIT_FAILURE);
 958#endif /* WIN32 */
 959    }
 960
 961    if (device != NULL && sockpath == NULL) {
 962        sockpath = g_malloc(128);
 963        snprintf(sockpath, 128, SOCKET_PATH, basename(device));
 964    }
 965
 966    server = qio_net_listener_new();
 967    if (socket_activation == 0) {
 968        int backlog;
 969
 970        if (persistent || shared == 0) {
 971            backlog = SOMAXCONN;
 972        } else {
 973            backlog = MIN(shared, SOMAXCONN);
 974        }
 975#ifdef CONFIG_SELINUX
 976        if (selinux_label && setsockcreatecon_raw(selinux_label) == -1) {
 977            error_report("Cannot set SELinux socket create context to %s: %s",
 978                         selinux_label, strerror(errno));
 979            exit(EXIT_FAILURE);
 980        }
 981#endif
 982        saddr = nbd_build_socket_address(sockpath, bindto, port);
 983        if (qio_net_listener_open_sync(server, saddr, backlog,
 984                                       &local_err) < 0) {
 985            object_unref(OBJECT(server));
 986            error_report_err(local_err);
 987            exit(EXIT_FAILURE);
 988        }
 989#ifdef CONFIG_SELINUX
 990        if (selinux_label && setsockcreatecon_raw(NULL) == -1) {
 991            error_report("Cannot clear SELinux socket create context: %s",
 992                         strerror(errno));
 993            exit(EXIT_FAILURE);
 994        }
 995#endif
 996    } else {
 997        size_t i;
 998        /* See comment in check_socket_activation above. */
 999        for (i = 0; i < socket_activation; i++) {
1000            QIOChannelSocket *sioc;
1001            sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
1002                                             &local_err);
1003            if (sioc == NULL) {
1004                object_unref(OBJECT(server));
1005                error_reportf_err(local_err,
1006                                  "Failed to use socket activation: ");
1007                exit(EXIT_FAILURE);
1008            }
1009            qio_net_listener_add(server, sioc);
1010            object_unref(OBJECT(sioc));
1011        }
1012    }
1013
1014    qemu_init_main_loop(&error_fatal);
1015    bdrv_init();
1016    atexit(qemu_nbd_shutdown);
1017
1018    srcpath = argv[optind];
1019    if (imageOpts) {
1020        QemuOpts *opts;
1021        if (fmt) {
1022            error_report("--image-opts and -f are mutually exclusive");
1023            exit(EXIT_FAILURE);
1024        }
1025        opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
1026        if (!opts) {
1027            qemu_opts_reset(&file_opts);
1028            exit(EXIT_FAILURE);
1029        }
1030        options = qemu_opts_to_qdict(opts, NULL);
1031        qemu_opts_reset(&file_opts);
1032        blk = blk_new_open(NULL, NULL, options, flags, &local_err);
1033    } else {
1034        if (fmt) {
1035            options = qdict_new();
1036            qdict_put_str(options, "driver", fmt);
1037        }
1038        blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
1039    }
1040
1041    if (!blk) {
1042        error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
1043                          argv[optind]);
1044        exit(EXIT_FAILURE);
1045    }
1046    bs = blk_bs(blk);
1047
1048    if (dev_offset) {
1049        QDict *raw_opts = qdict_new();
1050        qdict_put_str(raw_opts, "driver", "raw");
1051        qdict_put_str(raw_opts, "file", bs->node_name);
1052        qdict_put_int(raw_opts, "offset", dev_offset);
1053        bs = bdrv_open(NULL, NULL, raw_opts, flags, &error_fatal);
1054        blk_remove_bs(blk);
1055        blk_insert_bs(blk, bs, &error_fatal);
1056        bdrv_unref(bs);
1057    }
1058
1059    blk_set_enable_write_cache(blk, !writethrough);
1060
1061    if (sn_opts) {
1062        ret = bdrv_snapshot_load_tmp(bs,
1063                                     qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1064                                     qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1065                                     &local_err);
1066    } else if (sn_id_or_name) {
1067        ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1068                                                   &local_err);
1069    }
1070    if (ret < 0) {
1071        error_reportf_err(local_err, "Failed to load snapshot: ");
1072        exit(EXIT_FAILURE);
1073    }
1074
1075    bs->detect_zeroes = detect_zeroes;
1076
1077    nbd_server_is_qemu_nbd(true);
1078
1079    export_opts = g_new(BlockExportOptions, 1);
1080    *export_opts = (BlockExportOptions) {
1081        .type               = BLOCK_EXPORT_TYPE_NBD,
1082        .id                 = g_strdup("qemu-nbd-export"),
1083        .node_name          = g_strdup(bdrv_get_node_name(bs)),
1084        .has_writethrough   = true,
1085        .writethrough       = writethrough,
1086        .has_writable       = true,
1087        .writable           = !readonly,
1088        .u.nbd = {
1089            .has_name             = true,
1090            .name                 = g_strdup(export_name),
1091            .has_description      = !!export_description,
1092            .description          = g_strdup(export_description),
1093            .has_bitmaps          = !!bitmaps,
1094            .bitmaps              = bitmaps,
1095            .has_allocation_depth = alloc_depth,
1096            .allocation_depth     = alloc_depth,
1097        },
1098    };
1099    blk_exp_add(export_opts, &error_fatal);
1100    qapi_free_BlockExportOptions(export_opts);
1101
1102    if (device) {
1103#if HAVE_NBD_DEVICE
1104        int ret;
1105
1106        ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
1107        if (ret != 0) {
1108            error_report("Failed to create client thread: %s", strerror(ret));
1109            exit(EXIT_FAILURE);
1110        }
1111#endif
1112    } else {
1113        /* Shut up GCC warnings.  */
1114        memset(&client_thread, 0, sizeof(client_thread));
1115    }
1116
1117    nbd_update_server_watch();
1118
1119    if (pid_file_name) {
1120        qemu_write_pidfile(pid_file_name, &error_fatal);
1121    }
1122
1123    /* now when the initialization is (almost) complete, chdir("/")
1124     * to free any busy filesystems */
1125    if (chdir("/") < 0) {
1126        error_report("Could not chdir to root directory: %s",
1127                     strerror(errno));
1128        exit(EXIT_FAILURE);
1129    }
1130
1131    if (fork_process) {
1132        dup2(old_stderr, STDERR_FILENO);
1133        close(old_stderr);
1134    }
1135
1136    state = RUNNING;
1137    do {
1138        main_loop_wait(false);
1139        if (state == TERMINATE) {
1140            blk_exp_close_all();
1141            state = TERMINATED;
1142        }
1143    } while (state != TERMINATED);
1144
1145    blk_unref(blk);
1146    if (sockpath) {
1147        unlink(sockpath);
1148    }
1149
1150    qemu_opts_del(sn_opts);
1151
1152    if (device) {
1153        void *ret;
1154        pthread_join(client_thread, &ret);
1155        exit(ret != NULL);
1156    } else {
1157        exit(EXIT_SUCCESS);
1158    }
1159}
1160