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 <getopt.h>
  21 #include <libgen.h>
  22 #include <pthread.h>
  23
  24 #include "qemu/help-texts.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 #define QEMU_NBD_OPT_TLSHOSTNAME   267
  73
  74 #define MBR_SIZE 512
  75
  76 static int persistent = 0;
  77 static enum { RUNNING, TERMINATE, TERMINATED } state;
  78 static int shared = 1;
  79 static int nb_fds;
  80 static QIONetListener *server;
  81 static QCryptoTLSCreds *tlscreds;
  82 static const char *tlsauthz;
  83
  84 static void usage(const char *name)
  85 {
  86     (printf) (
  87 "Usage: %s [OPTIONS] FILE\n"
  88 "  or:  %s -L [OPTIONS]\n"
  89 "QEMU Disk Network Block Device Utility\n"
  90 "\n"
  91 "  -h, --help                display this help and exit\n"
  92 "  -V, --version             output version information and exit\n"
  93 "\n"
  94 "Connection properties:\n"
  95 "  -p, --port=PORT           port to listen on (default `%d')\n"
  96 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
  97 "  -k, --socket=PATH         path to the unix socket\n"
  98 "                            (default '"SOCKET_PATH"')\n"
  99 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
 100 "  -t, --persistent          don't exit on the last connection\n"
 101 "  -v, --verbose             display extra debugging information\n"
 102 "  -x, --export-name=NAME    expose export by name (default is empty string)\n"
 103 "  -D, --description=TEXT    export a human-readable description\n"
 104 "\n"
 105 "Exposing part of the image:\n"
 106 "  -o, --offset=OFFSET       offset into the image\n"
 107 "  -A, --allocation-depth    expose the allocation depth\n"
 108 "  -B, --bitmap=NAME         expose a persistent dirty bitmap\n"
 109 "\n"
 110 "General purpose options:\n"
 111 "  -L, --list                list exports available from another NBD server\n"
 112 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
 113 "                            passwords and/or encryption keys\n"
 114 "  --tls-creds=ID            use id of an earlier --object to provide TLS\n"
 115 "  --tls-authz=ID            use id of an earlier --object to provide\n"
 116 "                            authorization\n"
 117 "  -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
 118 "                            specify tracing options\n"
 119 "  --fork                    fork off the server process and exit the parent\n"
 120 "                            once the server is running\n"
 121 "  --pid-file=PATH           store the server's process ID in the given file\n"
 122 #ifdef CONFIG_SELINUX
 123 "  --selinux-label=LABEL     set SELinux process label on listening socket\n"
 124 #endif
 125 #if HAVE_NBD_DEVICE
 126 "\n"
 127 "Kernel NBD client support:\n"
 128 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
 129 "  -d, --disconnect          disconnect the specified device\n"
 130 #endif
 131 "\n"
 132 "Block device options:\n"
 133 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
 134 "  -r, --read-only           export read-only\n"
 135 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
 136 "                            file with backing_file=FILE, redirect the write to\n"
 137 "                            the temporary one\n"
 138 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
 139 "                            load an internal snapshot inside FILE and export it\n"
 140 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
 141 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
 142 "                            '[ID_OR_NAME]'\n"
 143 "  -n, --nocache             disable host cache\n"
 144 "      --cache=MODE          set cache mode used to access the disk image, the\n"
 145 "                            valid options are: 'none', 'writeback' (default),\n"
 146 "                            'writethrough', 'directsync' and 'unsafe'\n"
 147 "      --aio=MODE            set AIO mode (native, io_uring or threads)\n"
 148 "      --discard=MODE        set discard mode (ignore, unmap)\n"
 149 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
 150 "      --image-opts          treat FILE as a full set of image options\n"
 151 "\n"
 152 QEMU_HELP_BOTTOM "\n"
 153     , name, name, NBD_DEFAULT_PORT, "DEVICE");
 154 }
 155
 156 static void version(const char *name)
 157 {
 158     printf(
 159 "%s " QEMU_FULL_VERSION "\n"
 160 "Written by Anthony Liguori.\n"
 161 "\n"
 162 QEMU_COPYRIGHT "\n"
 163 "This is free software; see the source for copying conditions.  There is NO\n"
 164 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
 165     , name);
 166 }
 167
 168 #ifdef CONFIG_POSIX
 169 /*
 170  * The client thread uses SIGTERM to interrupt the server.  A signal
 171  * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
 172  */
 173 void qemu_system_killed(int signum, pid_t pid)
 174 {
 175     qatomic_cmpxchg(&state, RUNNING, TERMINATE);
 176     qemu_notify_event();
 177 }
 178 #endif /* CONFIG_POSIX */
 179
 180 static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
 181                                 const char *hostname)
 182 {
 183     int ret = EXIT_FAILURE;
 184     int rc;
 185     Error *err = NULL;
 186     QIOChannelSocket *sioc;
 187     NBDExportInfo *list;
 188     int i, j;
 189
 190     sioc = qio_channel_socket_new();
 191     if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
 192         error_report_err(err);
 193         goto out;
 194     }
 195     rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
 196                                  &err);
 197     if (rc < 0) {
 198         if (err) {
 199             error_report_err(err);
 200         }
 201         goto out;
 202     }
 203     printf("exports available: %d\n", rc);
 204     for (i = 0; i < rc; i++) {
 205         printf(" export: '%s'\n", list[i].name);
 206         if (list[i].description && *list[i].description) {
 207             printf("  description: %s\n", list[i].description);
 208         }
 209         if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
 210             static const char *const flag_names[] = {
 211                 [NBD_FLAG_READ_ONLY_BIT]            = "readonly",
 212                 [NBD_FLAG_SEND_FLUSH_BIT]           = "flush",
 213                 [NBD_FLAG_SEND_FUA_BIT]             = "fua",
 214                 [NBD_FLAG_ROTATIONAL_BIT]           = "rotational",
 215                 [NBD_FLAG_SEND_TRIM_BIT]            = "trim",
 216                 [NBD_FLAG_SEND_WRITE_ZEROES_BIT]    = "zeroes",
 217                 [NBD_FLAG_SEND_DF_BIT]              = "df",
 218                 [NBD_FLAG_CAN_MULTI_CONN_BIT]       = "multi",
 219                 [NBD_FLAG_SEND_RESIZE_BIT]          = "resize",
 220                 [NBD_FLAG_SEND_CACHE_BIT]           = "cache",
 221                 [NBD_FLAG_SEND_FAST_ZERO_BIT]       = "fast-zero",
 222                 [NBD_FLAG_BLOCK_STAT_PAYLOAD_BIT]   = "block-status-payload",
 223             };
 224
 225             printf("  size:  %" PRIu64 "\n", list[i].size);
 226             printf("  flags: 0x%x (", list[i].flags);
 227             for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) {
 228                 if (flag_names[bit] && (list[i].flags & (1 << bit))) {
 229                     printf(" %s", flag_names[bit]);
 230                 }
 231             }
 232             printf(" )\n");
 233         }
 234         if (list[i].min_block) {
 235             printf("  min block: %u\n", list[i].min_block);
 236             printf("  opt block: %u\n", list[i].opt_block);
 237             printf("  max block: %u\n", list[i].max_block);
 238         }
 239         printf("  transaction size: %s\n",
 240                list[i].mode >= NBD_MODE_EXTENDED ?
 241                "64-bit" : "32-bit");
 242         if (list[i].n_contexts) {
 243             printf("  available meta contexts: %d\n", list[i].n_contexts);
 244             for (j = 0; j < list[i].n_contexts; j++) {
 245                 printf("   %s\n", list[i].contexts[j]);
 246             }
 247         }
 248     }
 249     nbd_free_export_list(list, rc);
 250
 251     ret = EXIT_SUCCESS;
 252  out:
 253     object_unref(OBJECT(sioc));
 254     return ret;
 255 }
 256
 257
 258 struct NbdClientOpts {
 259     char *device;
 260     char *srcpath;
 261     SocketAddress *saddr;
 262     int old_stderr;
 263     bool fork_process;
 264     bool verbose;
 265 };
 266
 267 static void nbd_client_release_pipe(int old_stderr)
 268 {
 269     /* Close stderr so that the qemu-nbd process exits.  */
 270     if (dup2(old_stderr, STDERR_FILENO) < 0) {
 271         error_report("Could not release pipe to parent: %s",
 272                      strerror(errno));
 273         exit(EXIT_FAILURE);
 274     }
 275     if (old_stderr != STDOUT_FILENO && close(old_stderr) < 0) {
 276         error_report("Could not release qemu-nbd: %s", strerror(errno));
 277         exit(EXIT_FAILURE);
 278     }
 279 }
 280
 281 #if HAVE_NBD_DEVICE
 282 static void *show_parts(void *arg)
 283 {
 284     char *device = arg;
 285     int nbd;
 286
 287     /* linux just needs an open() to trigger
 288      * the partition table update
 289      * but remember to load the module with max_part != 0 :
 290      *     modprobe nbd max_part=63
 291      */
 292     nbd = open(device, O_RDWR);
 293     if (nbd >= 0) {
 294         close(nbd);
 295     }
 296     return NULL;
 297 }
 298
 299 static void *nbd_client_thread(void *arg)
 300 {
 301     struct NbdClientOpts *opts = arg;
 302     /* TODO: Revisit this if nbd.ko ever gains support for structured reply */
 303     NBDExportInfo info = { .request_sizes = false, .name = g_strdup(""),
 304                            .mode = NBD_MODE_SIMPLE };
 305     QIOChannelSocket *sioc;
 306     int fd = -1;
 307     int ret = EXIT_FAILURE;
 308     pthread_t show_parts_thread;
 309     Error *local_error = NULL;
 310
 311     sioc = qio_channel_socket_new();
 312     if (qio_channel_socket_connect_sync(sioc,
 313                                         opts->saddr,
 314                                         &local_error) < 0) {
 315         error_report_err(local_error);
 316         goto out;
 317     }
 318
 319     if (nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, NULL, NULL,
 320                               &info, &local_error) < 0) {
 321         if (local_error) {
 322             error_report_err(local_error);
 323         }
 324         goto out;
 325     }
 326
 327     fd = open(opts->device, O_RDWR);
 328     if (fd < 0) {
 329         /* Linux-only, we can use %m in printf.  */
 330         error_report("Failed to open %s: %m", opts->device);
 331         goto out;
 332     }
 333
 334     if (nbd_init(fd, sioc, &info, &local_error) < 0) {
 335         error_report_err(local_error);
 336         goto out;
 337     }
 338
 339     /* update partition table */
 340     pthread_create(&show_parts_thread, NULL, show_parts, opts->device);
 341
 342     if (opts->verbose && !opts->fork_process) {
 343         fprintf(stderr, "NBD device %s is now connected to %s\n",
 344                 opts->device, opts->srcpath);
 345     } else {
 346         nbd_client_release_pipe(opts->old_stderr);
 347     }
 348
 349     if (nbd_client(fd) < 0) {
 350         goto out;
 351     }
 352
 353     ret = EXIT_SUCCESS;
 354
 355  out:
 356     if (fd >= 0) {
 357         close(fd);
 358     }
 359     object_unref(OBJECT(sioc));
 360     g_free(info.name);
 361     kill(getpid(), SIGTERM);
 362     return (void *) (intptr_t) ret;
 363 }
 364 #endif /* HAVE_NBD_DEVICE */
 365
 366 static int nbd_can_accept(void)
 367 {
 368     return state == RUNNING && (shared == 0 || nb_fds < shared);
 369 }
 370
 371 static void nbd_update_server_watch(void);
 372
 373 static void nbd_client_closed(NBDClient *client, bool negotiated)
 374 {
 375     nb_fds--;
 376     if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
 377         state = TERMINATE;
 378     }
 379     nbd_update_server_watch();
 380     nbd_client_put(client);
 381 }
 382
 383 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
 384                        gpointer opaque)
 385 {
 386     if (state >= TERMINATE) {
 387         return;
 388     }
 389
 390     nb_fds++;
 391     nbd_update_server_watch();
 392     nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
 393 }
 394
 395 static void nbd_update_server_watch(void)
 396 {
 397     if (nbd_can_accept()) {
 398         qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
 399     } else {
 400         qio_net_listener_set_client_func(server, NULL, NULL, NULL);
 401     }
 402 }
 403
 404
 405 static SocketAddress *nbd_build_socket_address(const char *sockpath,
 406                                                const char *bindto,
 407                                                const char *port)
 408 {
 409     SocketAddress *saddr;
 410
 411     saddr = g_new0(SocketAddress, 1);
 412     if (sockpath) {
 413         saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
 414         saddr->u.q_unix.path = g_strdup(sockpath);
 415     } else {
 416         InetSocketAddress *inet;
 417         saddr->type = SOCKET_ADDRESS_TYPE_INET;
 418         inet = &saddr->u.inet;
 419         inet->host = g_strdup(bindto);
 420         if (port) {
 421             inet->port = g_strdup(port);
 422         } else  {
 423             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 424         }
 425     }
 426
 427     return saddr;
 428 }
 429
 430
 431 static QemuOptsList file_opts = {
 432     .name = "file",
 433     .implied_opt_name = "file",
 434     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
 435     .desc = {
 436         /* no elements => accept any params */
 437         { /* end of list */ }
 438     },
 439 };
 440
 441 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
 442                                           Error **errp)
 443 {
 444     Object *obj;
 445     QCryptoTLSCreds *creds;
 446
 447     obj = object_resolve_path_component(
 448         object_get_objects_root(), id);
 449     if (!obj) {
 450         error_setg(errp, "No TLS credentials with id '%s'",
 451                    id);
 452         return NULL;
 453     }
 454     creds = (QCryptoTLSCreds *)
 455         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 456     if (!creds) {
 457         error_setg(errp, "Object with id '%s' is not TLS credentials",
 458                    id);
 459         return NULL;
 460     }
 461
 462     if (!qcrypto_tls_creds_check_endpoint(creds,
 463                                           list
 464                                           ? QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT
 465                                           : QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
 466                                           errp)) {
 467         return NULL;
 468     }
 469     object_ref(obj);
 470     return creds;
 471 }
 472
 473 static void setup_address_and_port(const char **address, const char **port)
 474 {
 475     if (*address == NULL) {
 476         *address = "0.0.0.0";
 477     }
 478
 479     if (*port == NULL) {
 480         *port = stringify(NBD_DEFAULT_PORT);
 481     }
 482 }
 483
 484 /*
 485  * Check socket parameters compatibility when socket activation is used.
 486  */
 487 static const char *socket_activation_validate_opts(const char *device,
 488                                                    const char *sockpath,
 489                                                    const char *address,
 490                                                    const char *port,
 491                                                    const char *selinux,
 492                                                    bool list)
 493 {
 494     if (device != NULL) {
 495         return "NBD device can't be set when using socket activation";
 496     }
 497
 498     if (sockpath != NULL) {
 499         return "Unix socket can't be set when using socket activation";
 500     }
 501
 502     if (address != NULL) {
 503         return "The interface can't be set when using socket activation";
 504     }
 505
 506     if (port != NULL) {
 507         return "TCP port number can't be set when using socket activation";
 508     }
 509
 510     if (selinux != NULL) {
 511         return "SELinux label can't be set when using socket activation";
 512     }
 513
 514     if (list) {
 515         return "List mode is incompatible with socket activation";
 516     }
 517
 518     return NULL;
 519 }
 520
 521 static void qemu_nbd_shutdown(void)
 522 {
 523     job_cancel_sync_all();
 524     blk_exp_close_all();
 525     bdrv_close_all();
 526 }
 527
 528 int main(int argc, char **argv)
 529 {
 530     BlockBackend *blk;
 531     BlockDriverState *bs;
 532     uint64_t dev_offset = 0;
 533     bool readonly = false;
 534     bool disconnect = false;
 535     const char *bindto = NULL;
 536     const char *port = NULL;
 537     char *sockpath = NULL;
 538     QemuOpts *sn_opts = NULL;
 539     const char *sn_id_or_name = NULL;
 540     const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:AB:L";
 541     struct option lopt[] = {
 542         { "help", no_argument, NULL, 'h' },
 543         { "version", no_argument, NULL, 'V' },
 544         { "bind", required_argument, NULL, 'b' },
 545         { "port", required_argument, NULL, 'p' },
 546         { "socket", required_argument, NULL, 'k' },
 547         { "offset", required_argument, NULL, 'o' },
 548         { "read-only", no_argument, NULL, 'r' },
 549         { "allocation-depth", no_argument, NULL, 'A' },
 550         { "bitmap", required_argument, NULL, 'B' },
 551         { "connect", required_argument, NULL, 'c' },
 552         { "disconnect", no_argument, NULL, 'd' },
 553         { "list", no_argument, NULL, 'L' },
 554         { "snapshot", no_argument, NULL, 's' },
 555         { "load-snapshot", required_argument, NULL, 'l' },
 556         { "nocache", no_argument, NULL, 'n' },
 557         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
 558         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
 559         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
 560         { "detect-zeroes", required_argument, NULL,
 561           QEMU_NBD_OPT_DETECT_ZEROES },
 562         { "shared", required_argument, NULL, 'e' },
 563         { "format", required_argument, NULL, 'f' },
 564         { "persistent", no_argument, NULL, 't' },
 565         { "verbose", no_argument, NULL, 'v' },
 566         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
 567         { "export-name", required_argument, NULL, 'x' },
 568         { "description", required_argument, NULL, 'D' },
 569         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
 570         { "tls-hostname", required_argument, NULL, QEMU_NBD_OPT_TLSHOSTNAME },
 571         { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
 572         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
 573         { "trace", required_argument, NULL, 'T' },
 574         { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
 575         { "pid-file", required_argument, NULL, QEMU_NBD_OPT_PID_FILE },
 576         { "selinux-label", required_argument, NULL,
 577           QEMU_NBD_OPT_SELINUX_LABEL },
 578         { NULL, 0, NULL, 0 }
 579     };
 580     int ch;
 581     int opt_ind = 0;
 582     int flags = BDRV_O_RDWR;
 583     int ret = 0;
 584     bool seen_cache = false;
 585     bool seen_discard = false;
 586     bool seen_aio = false;
 587     pthread_t client_thread;
 588     const char *fmt = NULL;
 589     Error *local_err = NULL;
 590     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
 591     QDict *options = NULL;
 592     const char *export_name = NULL; /* defaults to "" later for server mode */
 593     const char *export_description = NULL;
 594     BlockDirtyBitmapOrStrList *bitmaps = NULL;
 595     bool alloc_depth = false;
 596     const char *tlscredsid = NULL;
 597     const char *tlshostname = NULL;
 598     bool imageOpts = false;
 599     bool writethrough = false; /* Client will flush as needed. */
 600     bool list = false;
 601     unsigned socket_activation;
 602     const char *pid_file_name = NULL;
 603     const char *selinux_label = NULL;
 604     BlockExportOptions *export_opts;
 605     struct NbdClientOpts opts = {
 606         .fork_process = false,
 607         .verbose = false,
 608         .device = NULL,
 609         .srcpath = NULL,
 610         .saddr = NULL,
 611         .old_stderr = STDOUT_FILENO,
 612     };
 613
 614 #ifdef CONFIG_POSIX
 615     os_setup_early_signal_handling();
 616     os_setup_signal_handling();
 617 #endif
 618
 619     socket_init();
 620     error_init(argv[0]);
 621     module_call_init(MODULE_INIT_TRACE);
 622     qcrypto_init(&error_fatal);
 623
 624     module_call_init(MODULE_INIT_QOM);
 625     qemu_add_opts(&qemu_trace_opts);
 626     qemu_init_exec_dir(argv[0]);
 627
 628     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 629         switch (ch) {
 630         case 's':
 631             flags |= BDRV_O_SNAPSHOT;
 632             break;
 633         case 'n':
 634             optarg = (char *) "none";
 635             /* fallthrough */
 636         case QEMU_NBD_OPT_CACHE:
 637             if (seen_cache) {
 638                 error_report("-n and --cache can only be specified once");
 639                 exit(EXIT_FAILURE);
 640             }
 641             seen_cache = true;
 642             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
 643                 error_report("Invalid cache mode `%s'", optarg);
 644                 exit(EXIT_FAILURE);
 645             }
 646             break;
 647         case QEMU_NBD_OPT_AIO:
 648             if (seen_aio) {
 649                 error_report("--aio can only be specified once");
 650                 exit(EXIT_FAILURE);
 651             }
 652             seen_aio = true;
 653             if (bdrv_parse_aio(optarg, &flags) < 0) {
 654                 error_report("Invalid aio mode '%s'", optarg);
 655                 exit(EXIT_FAILURE);
 656             }
 657             break;
 658         case QEMU_NBD_OPT_DISCARD:
 659             if (seen_discard) {
 660                 error_report("--discard can only be specified once");
 661                 exit(EXIT_FAILURE);
 662             }
 663             seen_discard = true;
 664             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 665                 error_report("Invalid discard mode `%s'", optarg);
 666                 exit(EXIT_FAILURE);
 667             }
 668             break;
 669         case QEMU_NBD_OPT_DETECT_ZEROES:
 670             detect_zeroes =
 671                 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
 672                                 optarg,
 673                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
 674                                 &local_err);
 675             if (local_err) {
 676                 error_reportf_err(local_err,
 677                                   "Failed to parse detect_zeroes mode: ");
 678                 exit(EXIT_FAILURE);
 679             }
 680             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
 681                 !(flags & BDRV_O_UNMAP)) {
 682                 error_report("setting detect-zeroes to unmap is not allowed "
 683                              "without setting discard operation to unmap");
 684                 exit(EXIT_FAILURE);
 685             }
 686             break;
 687         case 'b':
 688             bindto = optarg;
 689             break;
 690         case 'p':
 691             port = optarg;
 692             break;
 693         case 'o':
 694             if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
 695                 error_report("Invalid offset '%s'", optarg);
 696                 exit(EXIT_FAILURE);
 697             }
 698             break;
 699         case 'l':
 700             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 701                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
 702                                                   optarg, false);
 703                 if (!sn_opts) {
 704                     error_report("Failed in parsing snapshot param `%s'",
 705                                  optarg);
 706                     exit(EXIT_FAILURE);
 707                 }
 708             } else {
 709                 sn_id_or_name = optarg;
 710             }
 711             /* fall through */
 712         case 'r':
 713             readonly = true;
 714             flags &= ~BDRV_O_RDWR;
 715             break;
 716         case 'A':
 717             alloc_depth = true;
 718             break;
 719         case 'B':
 720             {
 721                 BlockDirtyBitmapOrStr *el = g_new(BlockDirtyBitmapOrStr, 1);
 722                 *el = (BlockDirtyBitmapOrStr) {
 723                     .type = QTYPE_QSTRING,
 724                     .u.local = g_strdup(optarg),
 725                 };
 726                 QAPI_LIST_PREPEND(bitmaps, el);
 727             }
 728             break;
 729         case 'k':
 730             sockpath = optarg;
 731             if (sockpath[0] != '/') {
 732                 error_report("socket path must be absolute");
 733                 exit(EXIT_FAILURE);
 734             }
 735             break;
 736         case 'd':
 737             disconnect = true;
 738             break;
 739         case 'c':
 740             opts.device = optarg;
 741             break;
 742         case 'e':
 743             if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
 744                 shared < 0) {
 745                 error_report("Invalid shared device number '%s'", optarg);
 746                 exit(EXIT_FAILURE);
 747             }
 748             break;
 749         case 'f':
 750             fmt = optarg;
 751             break;
 752         case 't':
 753             persistent = 1;
 754             break;
 755         case 'x':
 756             export_name = optarg;
 757             if (strlen(export_name) > NBD_MAX_STRING_SIZE) {
 758                 error_report("export name '%s' too long", export_name);
 759                 exit(EXIT_FAILURE);
 760             }
 761             break;
 762         case 'D':
 763             export_description = optarg;
 764             if (strlen(export_description) > NBD_MAX_STRING_SIZE) {
 765                 error_report("export description '%s' too long",
 766                              export_description);
 767                 exit(EXIT_FAILURE);
 768             }
 769             break;
 770         case 'v':
 771             opts.verbose = true;
 772             break;
 773         case 'V':
 774             version(argv[0]);
 775             exit(0);
 776             break;
 777         case 'h':
 778             usage(argv[0]);
 779             exit(0);
 780             break;
 781         case '?':
 782             error_report("Try `%s --help' for more information.", argv[0]);
 783             exit(EXIT_FAILURE);
 784         case QEMU_NBD_OPT_OBJECT:
 785             user_creatable_process_cmdline(optarg);
 786             break;
 787         case QEMU_NBD_OPT_TLSCREDS:
 788             tlscredsid = optarg;
 789             break;
 790         case QEMU_NBD_OPT_TLSHOSTNAME:
 791             tlshostname = optarg;
 792             break;
 793         case QEMU_NBD_OPT_IMAGE_OPTS:
 794             imageOpts = true;
 795             break;
 796         case 'T':
 797             trace_opt_parse(optarg);
 798             break;
 799         case QEMU_NBD_OPT_TLSAUTHZ:
 800             tlsauthz = optarg;
 801             break;
 802         case QEMU_NBD_OPT_FORK:
 803             opts.fork_process = true;
 804             break;
 805         case 'L':
 806             list = true;
 807             break;
 808         case QEMU_NBD_OPT_PID_FILE:
 809             pid_file_name = optarg;
 810             break;
 811         case QEMU_NBD_OPT_SELINUX_LABEL:
 812             selinux_label = optarg;
 813             break;
 814         }
 815     }
 816
 817     if (list) {
 818         if (argc != optind) {
 819             error_report("List mode is incompatible with a file name");
 820             exit(EXIT_FAILURE);
 821         }
 822         if (export_name || export_description || dev_offset ||
 823             opts.device || disconnect || fmt || sn_id_or_name || bitmaps ||
 824             alloc_depth || seen_aio || seen_discard || seen_cache) {
 825             error_report("List mode is incompatible with per-device settings");
 826             exit(EXIT_FAILURE);
 827         }
 828         if (opts.fork_process) {
 829             error_report("List mode is incompatible with forking");
 830             exit(EXIT_FAILURE);
 831         }
 832     } else if ((argc - optind) != 1) {
 833         error_report("Invalid number of arguments");
 834         error_printf("Try `%s --help' for more information.\n", argv[0]);
 835         exit(EXIT_FAILURE);
 836     } else if (!export_name) {
 837         export_name = "";
 838     }
 839
 840     if (!trace_init_backends()) {
 841         exit(1);
 842     }
 843     trace_init_file();
 844     qemu_set_log(LOG_TRACE, &error_fatal);
 845
 846     socket_activation = check_socket_activation();
 847     if (socket_activation == 0) {
 848         if (!sockpath) {
 849             setup_address_and_port(&bindto, &port);
 850         }
 851     } else {
 852         /* Using socket activation - check user didn't use -p etc. */
 853         const char *err_msg = socket_activation_validate_opts(opts.device,
 854                                                               sockpath,
 855                                                               bindto, port,
 856                                                               selinux_label,
 857                                                               list);
 858         if (err_msg != NULL) {
 859             error_report("%s", err_msg);
 860             exit(EXIT_FAILURE);
 861         }
 862
 863         /* qemu-nbd can only listen on a single socket.  */
 864         if (socket_activation > 1) {
 865             error_report("qemu-nbd does not support socket activation with %s > 1",
 866                          "LISTEN_FDS");
 867             exit(EXIT_FAILURE);
 868         }
 869     }
 870
 871     if (tlscredsid) {
 872         if (opts.device) {
 873             error_report("TLS is not supported with a host device");
 874             exit(EXIT_FAILURE);
 875         }
 876         if (tlsauthz && list) {
 877             error_report("TLS authorization is incompatible with export list");
 878             exit(EXIT_FAILURE);
 879         }
 880         if (tlshostname && !list) {
 881             error_report("TLS hostname is only supported with export list");
 882             exit(EXIT_FAILURE);
 883         }
 884         tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
 885         if (local_err) {
 886             error_reportf_err(local_err, "Failed to get TLS creds: ");
 887             exit(EXIT_FAILURE);
 888         }
 889     } else {
 890         if (tlsauthz) {
 891             error_report("--tls-authz is not permitted without --tls-creds");
 892             exit(EXIT_FAILURE);
 893         }
 894         if (tlshostname) {
 895             error_report("--tls-hostname is not permitted without --tls-creds");
 896             exit(EXIT_FAILURE);
 897         }
 898     }
 899
 900     if (selinux_label) {
 901 #ifdef CONFIG_SELINUX
 902         if (sockpath == NULL && opts.device == NULL) {
 903             error_report("--selinux-label is not permitted without --socket");
 904             exit(EXIT_FAILURE);
 905         }
 906 #else
 907         error_report("SELinux support not enabled in this binary");
 908         exit(EXIT_FAILURE);
 909 #endif
 910     }
 911
 912     if (list) {
 913         opts.saddr = nbd_build_socket_address(sockpath, bindto, port);
 914         return qemu_nbd_client_list(opts.saddr, tlscreds,
 915                                     tlshostname ? tlshostname : bindto);
 916     }
 917
 918 #if !HAVE_NBD_DEVICE
 919     if (disconnect || opts.device) {
 920         error_report("Kernel /dev/nbdN support not available");
 921         exit(EXIT_FAILURE);
 922     }
 923 #else /* HAVE_NBD_DEVICE */
 924     if (disconnect) {
 925         int nbdfd = open(argv[optind], O_RDWR);
 926         if (nbdfd < 0) {
 927             error_report("Cannot open %s: %s", argv[optind],
 928                          strerror(errno));
 929             exit(EXIT_FAILURE);
 930         }
 931         nbd_disconnect(nbdfd);
 932
 933         close(nbdfd);
 934
 935         printf("%s disconnected\n", argv[optind]);
 936
 937         return 0;
 938     }
 939 #endif
 940
 941     if ((opts.device && !opts.verbose) || opts.fork_process) {
 942 #ifndef WIN32
 943         g_autoptr(GError) err = NULL;
 944         int stderr_fd[2];
 945         pid_t pid;
 946
 947         if (!g_unix_open_pipe(stderr_fd, FD_CLOEXEC, &err)) {
 948             error_report("Error setting up communication pipe: %s",
 949                          err->message);
 950             exit(EXIT_FAILURE);
 951         }
 952
 953         /* Now daemonize, but keep a communication channel open to
 954          * print errors and exit with the proper status code.
 955          */
 956         pid = fork();
 957         if (pid < 0) {
 958             error_report("Failed to fork: %s", strerror(errno));
 959             exit(EXIT_FAILURE);
 960         } else if (pid == 0) {
 961             int saved_errno;
 962
 963             close(stderr_fd[0]);
 964
 965             /* Remember parent's stderr if we will be restoring it. */
 966             if (opts.verbose /* fork_process is set */) {
 967                 opts.old_stderr = dup(STDERR_FILENO);
 968                 if (opts.old_stderr < 0) {
 969                     error_report("Could not dup original stderr: %s",
 970                                  strerror(errno));
 971                     exit(EXIT_FAILURE);
 972                 }
 973             }
 974
 975             ret = qemu_daemon(1, 0);
 976             saved_errno = errno;    /* dup2 will overwrite error below */
 977
 978             /* Temporarily redirect stderr to the parent's pipe...  */
 979             if (dup2(stderr_fd[1], STDERR_FILENO) < 0) {
 980                 char str[256];
 981                 snprintf(str, sizeof(str),
 982                          "%s: Failed to link stderr to the pipe: %s\n",
 983                          g_get_prgname(), strerror(errno));
 984                 /*
 985                  * We are unable to use error_report() here as we need to get
 986                  * stderr pointed to the parent's pipe. Write to that pipe
 987                  * manually.
 988                  */
 989                 ret = write(stderr_fd[1], str, strlen(str));
 990                 exit(EXIT_FAILURE);
 991             }
 992
 993             if (ret < 0) {
 994                 error_report("Failed to daemonize: %s", strerror(saved_errno));
 995                 exit(EXIT_FAILURE);
 996             }
 997
 998             /* ... close the descriptor we inherited and go on.  */
 999             close(stderr_fd[1]);
1000         } else {
1001             bool errors = false;
1002             char *buf;
1003
1004             /* In the parent.  Print error messages from the child until
1005              * it closes the pipe.
1006              */
1007             close(stderr_fd[1]);
1008             buf = g_malloc(1024);
1009             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
1010                 errors = true;
1011                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
1012                 if (ret < 0) {
1013                     exit(EXIT_FAILURE);
1014                 }
1015             }
1016             if (ret < 0) {
1017                 error_report("Cannot read from daemon: %s",
1018                              strerror(errno));
1019                 exit(EXIT_FAILURE);
1020             }
1021
1022             /* Usually the daemon should not print any message.
1023              * Exit with zero status in that case.
1024              */
1025             exit(errors);
1026         }
1027 #else /* WIN32 */
1028         error_report("Unable to fork into background on Windows hosts");
1029         exit(EXIT_FAILURE);
1030 #endif /* WIN32 */
1031     }
1032
1033     if (opts.device != NULL && sockpath == NULL) {
1034         sockpath = g_malloc(128);
1035         snprintf(sockpath, 128, SOCKET_PATH, basename(opts.device));
1036     }
1037
1038     server = qio_net_listener_new();
1039     if (socket_activation == 0) {
1040         int backlog;
1041
1042         if (persistent || shared == 0) {
1043             backlog = SOMAXCONN;
1044         } else {
1045             backlog = MIN(shared, SOMAXCONN);
1046         }
1047 #ifdef CONFIG_SELINUX
1048         if (selinux_label && setsockcreatecon_raw(selinux_label) == -1) {
1049             error_report("Cannot set SELinux socket create context to %s: %s",
1050                          selinux_label, strerror(errno));
1051             exit(EXIT_FAILURE);
1052         }
1053 #endif
1054         opts.saddr = nbd_build_socket_address(sockpath, bindto, port);
1055         if (qio_net_listener_open_sync(server, opts.saddr, backlog,
1056                                        &local_err) < 0) {
1057             object_unref(OBJECT(server));
1058             error_report_err(local_err);
1059             exit(EXIT_FAILURE);
1060         }
1061 #ifdef CONFIG_SELINUX
1062         if (selinux_label && setsockcreatecon_raw(NULL) == -1) {
1063             error_report("Cannot clear SELinux socket create context: %s",
1064                          strerror(errno));
1065             exit(EXIT_FAILURE);
1066         }
1067 #endif
1068     } else {
1069         size_t i;
1070         /* See comment in check_socket_activation above. */
1071         for (i = 0; i < socket_activation; i++) {
1072             QIOChannelSocket *sioc;
1073             sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
1074                                              &local_err);
1075             if (sioc == NULL) {
1076                 object_unref(OBJECT(server));
1077                 error_reportf_err(local_err,
1078                                   "Failed to use socket activation: ");
1079                 exit(EXIT_FAILURE);
1080             }
1081             qio_net_listener_add(server, sioc);
1082             object_unref(OBJECT(sioc));
1083         }
1084     }
1085
1086     qemu_init_main_loop(&error_fatal);
1087     bdrv_init();
1088     atexit(qemu_nbd_shutdown);
1089
1090     opts.srcpath = argv[optind];
1091     if (imageOpts) {
1092         QemuOpts *o;
1093         if (fmt) {
1094             error_report("--image-opts and -f are mutually exclusive");
1095             exit(EXIT_FAILURE);
1096         }
1097         o = qemu_opts_parse_noisily(&file_opts, opts.srcpath, true);
1098         if (!o) {
1099             qemu_opts_reset(&file_opts);
1100             exit(EXIT_FAILURE);
1101         }
1102         options = qemu_opts_to_qdict(o, NULL);
1103         qemu_opts_reset(&file_opts);
1104         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
1105     } else {
1106         if (fmt) {
1107             options = qdict_new();
1108             qdict_put_str(options, "driver", fmt);
1109         }
1110         blk = blk_new_open(opts.srcpath, NULL, options, flags, &local_err);
1111     }
1112
1113     if (!blk) {
1114         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
1115                           argv[optind]);
1116         exit(EXIT_FAILURE);
1117     }
1118     bs = blk_bs(blk);
1119
1120     if (dev_offset) {
1121         QDict *raw_opts = qdict_new();
1122         qdict_put_str(raw_opts, "driver", "raw");
1123         qdict_put_str(raw_opts, "file", bs->node_name);
1124         qdict_put_int(raw_opts, "offset", dev_offset);
1125
1126         bs = bdrv_open(NULL, NULL, raw_opts, flags, &error_fatal);
1127
1128         blk_remove_bs(blk);
1129         blk_insert_bs(blk, bs, &error_fatal);
1130         bdrv_unref(bs);
1131     }
1132
1133     blk_set_enable_write_cache(blk, !writethrough);
1134
1135     if (sn_opts) {
1136         ret = bdrv_snapshot_load_tmp(bs,
1137                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1138                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1139                                      &local_err);
1140     } else if (sn_id_or_name) {
1141         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1142                                                    &local_err);
1143     }
1144     if (ret < 0) {
1145         error_reportf_err(local_err, "Failed to load snapshot: ");
1146         exit(EXIT_FAILURE);
1147     }
1148
1149     bs->detect_zeroes = detect_zeroes;
1150
1151     nbd_server_is_qemu_nbd(shared);
1152
1153     export_opts = g_new(BlockExportOptions, 1);
1154     *export_opts = (BlockExportOptions) {
1155         .type               = BLOCK_EXPORT_TYPE_NBD,
1156         .id                 = g_strdup("qemu-nbd-export"),
1157         .node_name          = g_strdup(bdrv_get_node_name(bs)),
1158         .has_writethrough   = true,
1159         .writethrough       = writethrough,
1160         .has_writable       = true,
1161         .writable           = !readonly,
1162         .u.nbd = {
1163             .name                 = g_strdup(export_name),
1164             .description          = g_strdup(export_description),
1165             .has_bitmaps          = !!bitmaps,
1166             .bitmaps              = bitmaps,
1167             .has_allocation_depth = alloc_depth,
1168             .allocation_depth     = alloc_depth,
1169         },
1170     };
1171     blk_exp_add(export_opts, &error_fatal);
1172     qapi_free_BlockExportOptions(export_opts);
1173
1174     if (opts.device) {
1175 #if HAVE_NBD_DEVICE
1176         ret = pthread_create(&client_thread, NULL, nbd_client_thread, &opts);
1177         if (ret != 0) {
1178             error_report("Failed to create client thread: %s", strerror(ret));
1179             exit(EXIT_FAILURE);
1180         }
1181 #endif
1182     } else {
1183         /* Shut up GCC warnings.  */
1184         memset(&client_thread, 0, sizeof(client_thread));
1185     }
1186
1187     nbd_update_server_watch();
1188
1189     if (pid_file_name) {
1190         qemu_write_pidfile(pid_file_name, &error_fatal);
1191     }
1192
1193     /* now when the initialization is (almost) complete, chdir("/")
1194      * to free any busy filesystems */
1195     if (chdir("/") < 0) {
1196         error_report("Could not chdir to root directory: %s",
1197                      strerror(errno));
1198         exit(EXIT_FAILURE);
1199     }
1200
1201     if (opts.fork_process) {
1202         nbd_client_release_pipe(opts.old_stderr);
1203     }
1204
1205     state = RUNNING;
1206     do {
1207         main_loop_wait(false);
1208         if (state == TERMINATE) {
1209             blk_exp_close_all();
1210             state = TERMINATED;
1211         }
1212     } while (state != TERMINATED);
1213
1214     blk_unref(blk);
1215     if (sockpath) {
1216         unlink(sockpath);
1217     }
1218
1219     qemu_opts_del(sn_opts);
1220
1221     if (opts.device) {
1222         void *result;
1223         pthread_join(client_thread, &result);
1224         ret = (intptr_t)result;
1225         exit(ret);
1226     } else {
1227         exit(EXIT_SUCCESS);
1228     }
1229 }