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-common.h"
  25 #include "qapi/error.h"
  26 #include "qemu/cutils.h"
  27 #include "sysemu/block-backend.h"
  28 #include "block/block_int.h"
  29 #include "block/nbd.h"
  30 #include "qemu/main-loop.h"
  31 #include "qemu/module.h"
  32 #include "qemu/option.h"
  33 #include "qemu/error-report.h"
  34 #include "qemu/config-file.h"
  35 #include "qemu/bswap.h"
  36 #include "qemu/log.h"
  37 #include "qemu/systemd.h"
  38 #include "block/snapshot.h"
  39 #include "qapi/qmp/qdict.h"
  40 #include "qapi/qmp/qstring.h"
  41 #include "qom/object_interfaces.h"
  42 #include "io/channel-socket.h"
  43 #include "io/net-listener.h"
  44 #include "crypto/init.h"
  45 #include "trace/control.h"
  46 #include "qemu-version.h"
  47
  48 #ifdef __linux__
  49 #define HAVE_NBD_DEVICE 1
  50 #else
  51 #define HAVE_NBD_DEVICE 0
  52 #endif
  53
  54 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
  55 #define QEMU_NBD_OPT_CACHE         256
  56 #define QEMU_NBD_OPT_AIO           257
  57 #define QEMU_NBD_OPT_DISCARD       258
  58 #define QEMU_NBD_OPT_DETECT_ZEROES 259
  59 #define QEMU_NBD_OPT_OBJECT        260
  60 #define QEMU_NBD_OPT_TLSCREDS      261
  61 #define QEMU_NBD_OPT_IMAGE_OPTS    262
  62 #define QEMU_NBD_OPT_FORK          263
  63 #define QEMU_NBD_OPT_TLSAUTHZ      264
  64 #define QEMU_NBD_OPT_PID_FILE      265
  65
  66 #define MBR_SIZE 512
  67
  68 static NBDExport *export;
  69 static int verbose;
  70 static char *srcpath;
  71 static SocketAddress *saddr;
  72 static int persistent = 0;
  73 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
  74 static int shared = 1;
  75 static int nb_fds;
  76 static QIONetListener *server;
  77 static QCryptoTLSCreds *tlscreds;
  78 static const char *tlsauthz;
  79
  80 static void usage(const char *name)
  81 {
  82     (printf) (
  83 "Usage: %s [OPTIONS] FILE\n"
  84 "  or:  %s -L [OPTIONS]\n"
  85 "QEMU Disk Network Block Device Utility\n"
  86 "\n"
  87 "  -h, --help                display this help and exit\n"
  88 "  -V, --version             output version information and exit\n"
  89 "\n"
  90 "Connection properties:\n"
  91 "  -p, --port=PORT           port to listen on (default `%d')\n"
  92 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
  93 "  -k, --socket=PATH         path to the unix socket\n"
  94 "                            (default '"SOCKET_PATH"')\n"
  95 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
  96 "  -t, --persistent          don't exit on the last connection\n"
  97 "  -v, --verbose             display extra debugging information\n"
  98 "  -x, --export-name=NAME    expose export by name (default is empty string)\n"
  99 "  -D, --description=TEXT    export a human-readable description\n"
 100 "\n"
 101 "Exposing part of the image:\n"
 102 "  -o, --offset=OFFSET       offset into the image\n"
 103 "  -B, --bitmap=NAME         expose a persistent dirty bitmap\n"
 104 "\n"
 105 "General purpose options:\n"
 106 "  -L, --list                list exports available from another NBD server\n"
 107 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
 108 "                            passwords and/or encryption keys\n"
 109 "  --tls-creds=ID            use id of an earlier --object to provide TLS\n"
 110 "  --tls-authz=ID            use id of an earlier --object to provide\n"
 111 "                            authorization\n"
 112 "  -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
 113 "                            specify tracing options\n"
 114 "  --fork                    fork off the server process and exit the parent\n"
 115 "                            once the server is running\n"
 116 "  --pid-file=PATH           store the server's process ID in the given file\n"
 117 #if HAVE_NBD_DEVICE
 118 "\n"
 119 "Kernel NBD client support:\n"
 120 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
 121 "  -d, --disconnect          disconnect the specified device\n"
 122 #endif
 123 "\n"
 124 "Block device options:\n"
 125 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
 126 "  -r, --read-only           export read-only\n"
 127 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
 128 "                            file with backing_file=FILE, redirect the write to\n"
 129 "                            the temporary one\n"
 130 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
 131 "                            load an internal snapshot inside FILE and export it\n"
 132 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
 133 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
 134 "                            '[ID_OR_NAME]'\n"
 135 "  -n, --nocache             disable host cache\n"
 136 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
 137 "      --aio=MODE            set AIO mode (native, io_uring or threads)\n"
 138 "      --discard=MODE        set discard mode (ignore, unmap)\n"
 139 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
 140 "      --image-opts          treat FILE as a full set of image options\n"
 141 "\n"
 142 QEMU_HELP_BOTTOM "\n"
 143     , name, name, NBD_DEFAULT_PORT, "DEVICE");
 144 }
 145
 146 static void version(const char *name)
 147 {
 148     printf(
 149 "%s " QEMU_FULL_VERSION "\n"
 150 "Written by Anthony Liguori.\n"
 151 "\n"
 152 QEMU_COPYRIGHT "\n"
 153 "This is free software; see the source for copying conditions.  There is NO\n"
 154 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
 155     , name);
 156 }
 157
 158 static void termsig_handler(int signum)
 159 {
 160     atomic_cmpxchg(&state, RUNNING, TERMINATE);
 161     qemu_notify_event();
 162 }
 163
 164
 165 static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
 166                                 const char *hostname)
 167 {
 168     int ret = EXIT_FAILURE;
 169     int rc;
 170     Error *err = NULL;
 171     QIOChannelSocket *sioc;
 172     NBDExportInfo *list;
 173     int i, j;
 174
 175     sioc = qio_channel_socket_new();
 176     if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
 177         error_report_err(err);
 178         return EXIT_FAILURE;
 179     }
 180     rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
 181                                  &err);
 182     if (rc < 0) {
 183         if (err) {
 184             error_report_err(err);
 185         }
 186         goto out;
 187     }
 188     printf("exports available: %d\n", rc);
 189     for (i = 0; i < rc; i++) {
 190         printf(" export: '%s'\n", list[i].name);
 191         if (list[i].description && *list[i].description) {
 192             printf("  description: %s\n", list[i].description);
 193         }
 194         if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
 195             static const char *const flag_names[] = {
 196                 [NBD_FLAG_READ_ONLY_BIT]            = "readonly",
 197                 [NBD_FLAG_SEND_FLUSH_BIT]           = "flush",
 198                 [NBD_FLAG_SEND_FUA_BIT]             = "fua",
 199                 [NBD_FLAG_ROTATIONAL_BIT]           = "rotational",
 200                 [NBD_FLAG_SEND_TRIM_BIT]            = "trim",
 201                 [NBD_FLAG_SEND_WRITE_ZEROES_BIT]    = "zeroes",
 202                 [NBD_FLAG_SEND_DF_BIT]              = "df",
 203                 [NBD_FLAG_CAN_MULTI_CONN_BIT]       = "multi",
 204                 [NBD_FLAG_SEND_RESIZE_BIT]          = "resize",
 205                 [NBD_FLAG_SEND_CACHE_BIT]           = "cache",
 206                 [NBD_FLAG_SEND_FAST_ZERO_BIT]       = "fast-zero",
 207             };
 208
 209             printf("  size:  %" PRIu64 "\n", list[i].size);
 210             printf("  flags: 0x%x (", list[i].flags);
 211             for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) {
 212                 if (flag_names[bit] && (list[i].flags & (1 << bit))) {
 213                     printf(" %s", flag_names[bit]);
 214                 }
 215             }
 216             printf(" )\n");
 217         }
 218         if (list[i].min_block) {
 219             printf("  min block: %u\n", list[i].min_block);
 220             printf("  opt block: %u\n", list[i].opt_block);
 221             printf("  max block: %u\n", list[i].max_block);
 222         }
 223         if (list[i].n_contexts) {
 224             printf("  available meta contexts: %d\n", list[i].n_contexts);
 225             for (j = 0; j < list[i].n_contexts; j++) {
 226                 printf("   %s\n", list[i].contexts[j]);
 227             }
 228         }
 229     }
 230     nbd_free_export_list(list, rc);
 231
 232     ret = EXIT_SUCCESS;
 233  out:
 234     object_unref(OBJECT(sioc));
 235     return ret;
 236 }
 237
 238
 239 #if HAVE_NBD_DEVICE
 240 static void *show_parts(void *arg)
 241 {
 242     char *device = arg;
 243     int nbd;
 244
 245     /* linux just needs an open() to trigger
 246      * the partition table update
 247      * but remember to load the module with max_part != 0 :
 248      *     modprobe nbd max_part=63
 249      */
 250     nbd = open(device, O_RDWR);
 251     if (nbd >= 0) {
 252         close(nbd);
 253     }
 254     return NULL;
 255 }
 256
 257 static void *nbd_client_thread(void *arg)
 258 {
 259     char *device = arg;
 260     NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };
 261     QIOChannelSocket *sioc;
 262     int fd;
 263     int ret;
 264     pthread_t show_parts_thread;
 265     Error *local_error = NULL;
 266
 267     sioc = qio_channel_socket_new();
 268     if (qio_channel_socket_connect_sync(sioc,
 269                                         saddr,
 270                                         &local_error) < 0) {
 271         error_report_err(local_error);
 272         goto out;
 273     }
 274
 275     ret = nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc),
 276                                 NULL, NULL, NULL, &info, &local_error);
 277     if (ret < 0) {
 278         if (local_error) {
 279             error_report_err(local_error);
 280         }
 281         goto out_socket;
 282     }
 283
 284     fd = open(device, O_RDWR);
 285     if (fd < 0) {
 286         /* Linux-only, we can use %m in printf.  */
 287         error_report("Failed to open %s: %m", device);
 288         goto out_socket;
 289     }
 290
 291     ret = nbd_init(fd, sioc, &info, &local_error);
 292     if (ret < 0) {
 293         error_report_err(local_error);
 294         goto out_fd;
 295     }
 296
 297     /* update partition table */
 298     pthread_create(&show_parts_thread, NULL, show_parts, device);
 299
 300     if (verbose) {
 301         fprintf(stderr, "NBD device %s is now connected to %s\n",
 302                 device, srcpath);
 303     } else {
 304         /* Close stderr so that the qemu-nbd process exits.  */
 305         dup2(STDOUT_FILENO, STDERR_FILENO);
 306     }
 307
 308     ret = nbd_client(fd);
 309     if (ret) {
 310         goto out_fd;
 311     }
 312     close(fd);
 313     object_unref(OBJECT(sioc));
 314     g_free(info.name);
 315     kill(getpid(), SIGTERM);
 316     return (void *) EXIT_SUCCESS;
 317
 318 out_fd:
 319     close(fd);
 320 out_socket:
 321     object_unref(OBJECT(sioc));
 322 out:
 323     g_free(info.name);
 324     kill(getpid(), SIGTERM);
 325     return (void *) EXIT_FAILURE;
 326 }
 327 #endif /* HAVE_NBD_DEVICE */
 328
 329 static int nbd_can_accept(void)
 330 {
 331     return state == RUNNING && nb_fds < shared;
 332 }
 333
 334 static void nbd_export_closed(NBDExport *export)
 335 {
 336     assert(state == TERMINATING);
 337     state = TERMINATED;
 338 }
 339
 340 static void nbd_update_server_watch(void);
 341
 342 static void nbd_client_closed(NBDClient *client, bool negotiated)
 343 {
 344     nb_fds--;
 345     if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
 346         state = TERMINATE;
 347     }
 348     nbd_update_server_watch();
 349     nbd_client_put(client);
 350 }
 351
 352 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
 353                        gpointer opaque)
 354 {
 355     if (state >= TERMINATE) {
 356         return;
 357     }
 358
 359     nb_fds++;
 360     nbd_update_server_watch();
 361     nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
 362 }
 363
 364 static void nbd_update_server_watch(void)
 365 {
 366     if (nbd_can_accept()) {
 367         qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
 368     } else {
 369         qio_net_listener_set_client_func(server, NULL, NULL, NULL);
 370     }
 371 }
 372
 373
 374 static SocketAddress *nbd_build_socket_address(const char *sockpath,
 375                                                const char *bindto,
 376                                                const char *port)
 377 {
 378     SocketAddress *saddr;
 379
 380     saddr = g_new0(SocketAddress, 1);
 381     if (sockpath) {
 382         saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
 383         saddr->u.q_unix.path = g_strdup(sockpath);
 384     } else {
 385         InetSocketAddress *inet;
 386         saddr->type = SOCKET_ADDRESS_TYPE_INET;
 387         inet = &saddr->u.inet;
 388         inet->host = g_strdup(bindto);
 389         if (port) {
 390             inet->port = g_strdup(port);
 391         } else  {
 392             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 393         }
 394     }
 395
 396     return saddr;
 397 }
 398
 399
 400 static QemuOptsList file_opts = {
 401     .name = "file",
 402     .implied_opt_name = "file",
 403     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
 404     .desc = {
 405         /* no elements => accept any params */
 406         { /* end of list */ }
 407     },
 408 };
 409
 410 static QemuOptsList qemu_object_opts = {
 411     .name = "object",
 412     .implied_opt_name = "qom-type",
 413     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
 414     .desc = {
 415         { }
 416     },
 417 };
 418
 419 static bool qemu_nbd_object_print_help(const char *type, QemuOpts *opts)
 420 {
 421     if (user_creatable_print_help(type, opts)) {
 422         exit(0);
 423     }
 424     return true;
 425 }
 426
 427
 428 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
 429                                           Error **errp)
 430 {
 431     Object *obj;
 432     QCryptoTLSCreds *creds;
 433
 434     obj = object_resolve_path_component(
 435         object_get_objects_root(), id);
 436     if (!obj) {
 437         error_setg(errp, "No TLS credentials with id '%s'",
 438                    id);
 439         return NULL;
 440     }
 441     creds = (QCryptoTLSCreds *)
 442         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 443     if (!creds) {
 444         error_setg(errp, "Object with id '%s' is not TLS credentials",
 445                    id);
 446         return NULL;
 447     }
 448
 449     if (list) {
 450         if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
 451             error_setg(errp,
 452                        "Expecting TLS credentials with a client endpoint");
 453             return NULL;
 454         }
 455     } else {
 456         if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
 457             error_setg(errp,
 458                        "Expecting TLS credentials with a server endpoint");
 459             return NULL;
 460         }
 461     }
 462     object_ref(obj);
 463     return creds;
 464 }
 465
 466 static void setup_address_and_port(const char **address, const char **port)
 467 {
 468     if (*address == NULL) {
 469         *address = "0.0.0.0";
 470     }
 471
 472     if (*port == NULL) {
 473         *port = stringify(NBD_DEFAULT_PORT);
 474     }
 475 }
 476
 477 /*
 478  * Check socket parameters compatibility when socket activation is used.
 479  */
 480 static const char *socket_activation_validate_opts(const char *device,
 481                                                    const char *sockpath,
 482                                                    const char *address,
 483                                                    const char *port,
 484                                                    bool list)
 485 {
 486     if (device != NULL) {
 487         return "NBD device can't be set when using socket activation";
 488     }
 489
 490     if (sockpath != NULL) {
 491         return "Unix socket can't be set when using socket activation";
 492     }
 493
 494     if (address != NULL) {
 495         return "The interface can't be set when using socket activation";
 496     }
 497
 498     if (port != NULL) {
 499         return "TCP port number can't be set when using socket activation";
 500     }
 501
 502     if (list) {
 503         return "List mode is incompatible with socket activation";
 504     }
 505
 506     return NULL;
 507 }
 508
 509 static void qemu_nbd_shutdown(void)
 510 {
 511     job_cancel_sync_all();
 512     bdrv_close_all();
 513 }
 514
 515 int main(int argc, char **argv)
 516 {
 517     BlockBackend *blk;
 518     BlockDriverState *bs;
 519     uint64_t dev_offset = 0;
 520     bool readonly = false;
 521     bool disconnect = false;
 522     const char *bindto = NULL;
 523     const char *port = NULL;
 524     char *sockpath = NULL;
 525     char *device = NULL;
 526     int64_t fd_size;
 527     QemuOpts *sn_opts = NULL;
 528     const char *sn_id_or_name = NULL;
 529     const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:B:L";
 530     struct option lopt[] = {
 531         { "help", no_argument, NULL, 'h' },
 532         { "version", no_argument, NULL, 'V' },
 533         { "bind", required_argument, NULL, 'b' },
 534         { "port", required_argument, NULL, 'p' },
 535         { "socket", required_argument, NULL, 'k' },
 536         { "offset", required_argument, NULL, 'o' },
 537         { "read-only", no_argument, NULL, 'r' },
 538         { "bitmap", required_argument, NULL, 'B' },
 539         { "connect", required_argument, NULL, 'c' },
 540         { "disconnect", no_argument, NULL, 'd' },
 541         { "list", no_argument, NULL, 'L' },
 542         { "snapshot", no_argument, NULL, 's' },
 543         { "load-snapshot", required_argument, NULL, 'l' },
 544         { "nocache", no_argument, NULL, 'n' },
 545         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
 546         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
 547         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
 548         { "detect-zeroes", required_argument, NULL,
 549           QEMU_NBD_OPT_DETECT_ZEROES },
 550         { "shared", required_argument, NULL, 'e' },
 551         { "format", required_argument, NULL, 'f' },
 552         { "persistent", no_argument, NULL, 't' },
 553         { "verbose", no_argument, NULL, 'v' },
 554         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
 555         { "export-name", required_argument, NULL, 'x' },
 556         { "description", required_argument, NULL, 'D' },
 557         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
 558         { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
 559         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
 560         { "trace", required_argument, NULL, 'T' },
 561         { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
 562         { "pid-file", required_argument, NULL, QEMU_NBD_OPT_PID_FILE },
 563         { NULL, 0, NULL, 0 }
 564     };
 565     int ch;
 566     int opt_ind = 0;
 567     int flags = BDRV_O_RDWR;
 568     int ret = 0;
 569     bool seen_cache = false;
 570     bool seen_discard = false;
 571     bool seen_aio = false;
 572     pthread_t client_thread;
 573     const char *fmt = NULL;
 574     Error *local_err = NULL;
 575     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
 576     QDict *options = NULL;
 577     const char *export_name = NULL; /* defaults to "" later for server mode */
 578     const char *export_description = NULL;
 579     const char *bitmap = NULL;
 580     const char *tlscredsid = NULL;
 581     bool imageOpts = false;
 582     bool writethrough = true;
 583     char *trace_file = NULL;
 584     bool fork_process = false;
 585     bool list = false;
 586     int old_stderr = -1;
 587     unsigned socket_activation;
 588     const char *pid_file_name = NULL;
 589
 590     /* The client thread uses SIGTERM to interrupt the server.  A signal
 591      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
 592      */
 593     struct sigaction sa_sigterm;
 594     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
 595     sa_sigterm.sa_handler = termsig_handler;
 596     sigaction(SIGTERM, &sa_sigterm, NULL);
 597
 598 #ifdef CONFIG_POSIX
 599     signal(SIGPIPE, SIG_IGN);
 600 #endif
 601
 602     error_init(argv[0]);
 603     module_call_init(MODULE_INIT_TRACE);
 604     qcrypto_init(&error_fatal);
 605
 606     module_call_init(MODULE_INIT_QOM);
 607     qemu_add_opts(&qemu_object_opts);
 608     qemu_add_opts(&qemu_trace_opts);
 609     qemu_init_exec_dir(argv[0]);
 610
 611     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 612         switch (ch) {
 613         case 's':
 614             flags |= BDRV_O_SNAPSHOT;
 615             break;
 616         case 'n':
 617             optarg = (char *) "none";
 618             /* fallthrough */
 619         case QEMU_NBD_OPT_CACHE:
 620             if (seen_cache) {
 621                 error_report("-n and --cache can only be specified once");
 622                 exit(EXIT_FAILURE);
 623             }
 624             seen_cache = true;
 625             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
 626                 error_report("Invalid cache mode `%s'", optarg);
 627                 exit(EXIT_FAILURE);
 628             }
 629             break;
 630         case QEMU_NBD_OPT_AIO:
 631             if (seen_aio) {
 632                 error_report("--aio can only be specified once");
 633                 exit(EXIT_FAILURE);
 634             }
 635             seen_aio = true;
 636             if (bdrv_parse_aio(optarg, &flags) < 0) {
 637                 error_report("Invalid aio mode '%s'", optarg);
 638                 exit(EXIT_FAILURE);
 639             }
 640             break;
 641         case QEMU_NBD_OPT_DISCARD:
 642             if (seen_discard) {
 643                 error_report("--discard can only be specified once");
 644                 exit(EXIT_FAILURE);
 645             }
 646             seen_discard = true;
 647             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 648                 error_report("Invalid discard mode `%s'", optarg);
 649                 exit(EXIT_FAILURE);
 650             }
 651             break;
 652         case QEMU_NBD_OPT_DETECT_ZEROES:
 653             detect_zeroes =
 654                 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
 655                                 optarg,
 656                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
 657                                 &local_err);
 658             if (local_err) {
 659                 error_reportf_err(local_err,
 660                                   "Failed to parse detect_zeroes mode: ");
 661                 exit(EXIT_FAILURE);
 662             }
 663             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
 664                 !(flags & BDRV_O_UNMAP)) {
 665                 error_report("setting detect-zeroes to unmap is not allowed "
 666                              "without setting discard operation to unmap");
 667                 exit(EXIT_FAILURE);
 668             }
 669             break;
 670         case 'b':
 671             bindto = optarg;
 672             break;
 673         case 'p':
 674             port = optarg;
 675             break;
 676         case 'o':
 677             if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
 678                 error_report("Invalid offset '%s'", optarg);
 679                 exit(EXIT_FAILURE);
 680             }
 681             break;
 682         case 'l':
 683             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 684                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
 685                                                   optarg, false);
 686                 if (!sn_opts) {
 687                     error_report("Failed in parsing snapshot param `%s'",
 688                                  optarg);
 689                     exit(EXIT_FAILURE);
 690                 }
 691             } else {
 692                 sn_id_or_name = optarg;
 693             }
 694             /* fall through */
 695         case 'r':
 696             readonly = true;
 697             flags &= ~BDRV_O_RDWR;
 698             break;
 699         case 'B':
 700             bitmap = optarg;
 701             break;
 702         case 'k':
 703             sockpath = optarg;
 704             if (sockpath[0] != '/') {
 705                 error_report("socket path must be absolute");
 706                 exit(EXIT_FAILURE);
 707             }
 708             break;
 709         case 'd':
 710             disconnect = true;
 711             break;
 712         case 'c':
 713             device = optarg;
 714             break;
 715         case 'e':
 716             if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
 717                 shared < 1) {
 718                 error_report("Invalid shared device number '%s'", optarg);
 719                 exit(EXIT_FAILURE);
 720             }
 721             break;
 722         case 'f':
 723             fmt = optarg;
 724             break;
 725         case 't':
 726             persistent = 1;
 727             break;
 728         case 'x':
 729             export_name = optarg;
 730             if (strlen(export_name) > NBD_MAX_STRING_SIZE) {
 731                 error_report("export name '%s' too long", export_name);
 732                 exit(EXIT_FAILURE);
 733             }
 734             break;
 735         case 'D':
 736             export_description = optarg;
 737             if (strlen(export_description) > NBD_MAX_STRING_SIZE) {
 738                 error_report("export description '%s' too long",
 739                              export_description);
 740                 exit(EXIT_FAILURE);
 741             }
 742             break;
 743         case 'v':
 744             verbose = 1;
 745             break;
 746         case 'V':
 747             version(argv[0]);
 748             exit(0);
 749             break;
 750         case 'h':
 751             usage(argv[0]);
 752             exit(0);
 753             break;
 754         case '?':
 755             error_report("Try `%s --help' for more information.", argv[0]);
 756             exit(EXIT_FAILURE);
 757         case QEMU_NBD_OPT_OBJECT: {
 758             QemuOpts *opts;
 759             opts = qemu_opts_parse_noisily(&qemu_object_opts,
 760                                            optarg, true);
 761             if (!opts) {
 762                 exit(EXIT_FAILURE);
 763             }
 764         }   break;
 765         case QEMU_NBD_OPT_TLSCREDS:
 766             tlscredsid = optarg;
 767             break;
 768         case QEMU_NBD_OPT_IMAGE_OPTS:
 769             imageOpts = true;
 770             break;
 771         case 'T':
 772             g_free(trace_file);
 773             trace_file = trace_opt_parse(optarg);
 774             break;
 775         case QEMU_NBD_OPT_TLSAUTHZ:
 776             tlsauthz = optarg;
 777             break;
 778         case QEMU_NBD_OPT_FORK:
 779             fork_process = true;
 780             break;
 781         case 'L':
 782             list = true;
 783             break;
 784         case QEMU_NBD_OPT_PID_FILE:
 785             pid_file_name = optarg;
 786             break;
 787         }
 788     }
 789
 790     if (list) {
 791         if (argc != optind) {
 792             error_report("List mode is incompatible with a file name");
 793             exit(EXIT_FAILURE);
 794         }
 795         if (export_name || export_description || dev_offset ||
 796             device || disconnect || fmt || sn_id_or_name || bitmap ||
 797             seen_aio || seen_discard || seen_cache) {
 798             error_report("List mode is incompatible with per-device settings");
 799             exit(EXIT_FAILURE);
 800         }
 801         if (fork_process) {
 802             error_report("List mode is incompatible with forking");
 803             exit(EXIT_FAILURE);
 804         }
 805     } else if ((argc - optind) != 1) {
 806         error_report("Invalid number of arguments");
 807         error_printf("Try `%s --help' for more information.\n", argv[0]);
 808         exit(EXIT_FAILURE);
 809     } else if (!export_name) {
 810         export_name = "";
 811     }
 812
 813     qemu_opts_foreach(&qemu_object_opts,
 814                       user_creatable_add_opts_foreach,
 815                       qemu_nbd_object_print_help, &error_fatal);
 816
 817     if (!trace_init_backends()) {
 818         exit(1);
 819     }
 820     trace_init_file(trace_file);
 821     qemu_set_log(LOG_TRACE);
 822
 823     socket_activation = check_socket_activation();
 824     if (socket_activation == 0) {
 825         setup_address_and_port(&bindto, &port);
 826     } else {
 827         /* Using socket activation - check user didn't use -p etc. */
 828         const char *err_msg = socket_activation_validate_opts(device, sockpath,
 829                                                               bindto, port,
 830                                                               list);
 831         if (err_msg != NULL) {
 832             error_report("%s", err_msg);
 833             exit(EXIT_FAILURE);
 834         }
 835
 836         /* qemu-nbd can only listen on a single socket.  */
 837         if (socket_activation > 1) {
 838             error_report("qemu-nbd does not support socket activation with %s > 1",
 839                          "LISTEN_FDS");
 840             exit(EXIT_FAILURE);
 841         }
 842     }
 843
 844     if (tlscredsid) {
 845         if (sockpath) {
 846             error_report("TLS is only supported with IPv4/IPv6");
 847             exit(EXIT_FAILURE);
 848         }
 849         if (device) {
 850             error_report("TLS is not supported with a host device");
 851             exit(EXIT_FAILURE);
 852         }
 853         if (tlsauthz && list) {
 854             error_report("TLS authorization is incompatible with export list");
 855             exit(EXIT_FAILURE);
 856         }
 857         tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
 858         if (local_err) {
 859             error_report("Failed to get TLS creds %s",
 860                          error_get_pretty(local_err));
 861             exit(EXIT_FAILURE);
 862         }
 863     } else {
 864         if (tlsauthz) {
 865             error_report("--tls-authz is not permitted without --tls-creds");
 866             exit(EXIT_FAILURE);
 867         }
 868     }
 869
 870     if (list) {
 871         saddr = nbd_build_socket_address(sockpath, bindto, port);
 872         return qemu_nbd_client_list(saddr, tlscreds, bindto);
 873     }
 874
 875 #if !HAVE_NBD_DEVICE
 876     if (disconnect || device) {
 877         error_report("Kernel /dev/nbdN support not available");
 878         exit(EXIT_FAILURE);
 879     }
 880 #else /* HAVE_NBD_DEVICE */
 881     if (disconnect) {
 882         int nbdfd = open(argv[optind], O_RDWR);
 883         if (nbdfd < 0) {
 884             error_report("Cannot open %s: %s", argv[optind],
 885                          strerror(errno));
 886             exit(EXIT_FAILURE);
 887         }
 888         nbd_disconnect(nbdfd);
 889
 890         close(nbdfd);
 891
 892         printf("%s disconnected\n", argv[optind]);
 893
 894         return 0;
 895     }
 896 #endif
 897
 898     if ((device && !verbose) || fork_process) {
 899         int stderr_fd[2];
 900         pid_t pid;
 901         int ret;
 902
 903         if (qemu_pipe(stderr_fd) < 0) {
 904             error_report("Error setting up communication pipe: %s",
 905                          strerror(errno));
 906             exit(EXIT_FAILURE);
 907         }
 908
 909         /* Now daemonize, but keep a communication channel open to
 910          * print errors and exit with the proper status code.
 911          */
 912         pid = fork();
 913         if (pid < 0) {
 914             error_report("Failed to fork: %s", strerror(errno));
 915             exit(EXIT_FAILURE);
 916         } else if (pid == 0) {
 917             close(stderr_fd[0]);
 918
 919             old_stderr = dup(STDERR_FILENO);
 920             ret = qemu_daemon(1, 0);
 921
 922             /* Temporarily redirect stderr to the parent's pipe...  */
 923             dup2(stderr_fd[1], STDERR_FILENO);
 924             if (ret < 0) {
 925                 error_report("Failed to daemonize: %s", strerror(errno));
 926                 exit(EXIT_FAILURE);
 927             }
 928
 929             /* ... close the descriptor we inherited and go on.  */
 930             close(stderr_fd[1]);
 931         } else {
 932             bool errors = false;
 933             char *buf;
 934
 935             /* In the parent.  Print error messages from the child until
 936              * it closes the pipe.
 937              */
 938             close(stderr_fd[1]);
 939             buf = g_malloc(1024);
 940             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
 941                 errors = true;
 942                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
 943                 if (ret < 0) {
 944                     exit(EXIT_FAILURE);
 945                 }
 946             }
 947             if (ret < 0) {
 948                 error_report("Cannot read from daemon: %s",
 949                              strerror(errno));
 950                 exit(EXIT_FAILURE);
 951             }
 952
 953             /* Usually the daemon should not print any message.
 954              * Exit with zero status in that case.
 955              */
 956             exit(errors);
 957         }
 958     }
 959
 960     if (device != NULL && sockpath == NULL) {
 961         sockpath = g_malloc(128);
 962         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
 963     }
 964
 965     server = qio_net_listener_new();
 966     if (socket_activation == 0) {
 967         saddr = nbd_build_socket_address(sockpath, bindto, port);
 968         if (qio_net_listener_open_sync(server, saddr, 1, &local_err) < 0) {
 969             object_unref(OBJECT(server));
 970             error_report_err(local_err);
 971             exit(EXIT_FAILURE);
 972         }
 973     } else {
 974         size_t i;
 975         /* See comment in check_socket_activation above. */
 976         for (i = 0; i < socket_activation; i++) {
 977             QIOChannelSocket *sioc;
 978             sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
 979                                              &local_err);
 980             if (sioc == NULL) {
 981                 object_unref(OBJECT(server));
 982                 error_report("Failed to use socket activation: %s",
 983                              error_get_pretty(local_err));
 984                 exit(EXIT_FAILURE);
 985             }
 986             qio_net_listener_add(server, sioc);
 987             object_unref(OBJECT(sioc));
 988         }
 989     }
 990
 991     if (qemu_init_main_loop(&local_err)) {
 992         error_report_err(local_err);
 993         exit(EXIT_FAILURE);
 994     }
 995     bdrv_init();
 996     atexit(qemu_nbd_shutdown);
 997
 998     srcpath = argv[optind];
 999     if (imageOpts) {
1000         QemuOpts *opts;
1001         if (fmt) {
1002             error_report("--image-opts and -f are mutually exclusive");
1003             exit(EXIT_FAILURE);
1004         }
1005         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
1006         if (!opts) {
1007             qemu_opts_reset(&file_opts);
1008             exit(EXIT_FAILURE);
1009         }
1010         options = qemu_opts_to_qdict(opts, NULL);
1011         qemu_opts_reset(&file_opts);
1012         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
1013     } else {
1014         if (fmt) {
1015             options = qdict_new();
1016             qdict_put_str(options, "driver", fmt);
1017         }
1018         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
1019     }
1020
1021     if (!blk) {
1022         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
1023                           argv[optind]);
1024         exit(EXIT_FAILURE);
1025     }
1026     bs = blk_bs(blk);
1027
1028     blk_set_enable_write_cache(blk, !writethrough);
1029
1030     if (sn_opts) {
1031         ret = bdrv_snapshot_load_tmp(bs,
1032                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1033                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1034                                      &local_err);
1035     } else if (sn_id_or_name) {
1036         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1037                                                    &local_err);
1038     }
1039     if (ret < 0) {
1040         error_reportf_err(local_err, "Failed to load snapshot: ");
1041         exit(EXIT_FAILURE);
1042     }
1043
1044     bs->detect_zeroes = detect_zeroes;
1045     fd_size = blk_getlength(blk);
1046     if (fd_size < 0) {
1047         error_report("Failed to determine the image length: %s",
1048                      strerror(-fd_size));
1049         exit(EXIT_FAILURE);
1050     }
1051
1052     if (dev_offset >= fd_size) {
1053         error_report("Offset (%" PRIu64 ") has to be smaller than the image "
1054                      "size (%" PRId64 ")", dev_offset, fd_size);
1055         exit(EXIT_FAILURE);
1056     }
1057     fd_size -= dev_offset;
1058
1059     export = nbd_export_new(bs, dev_offset, fd_size, export_name,
1060                             export_description, bitmap, readonly, shared > 1,
1061                             nbd_export_closed, writethrough, NULL,
1062                             &error_fatal);
1063
1064     if (device) {
1065 #if HAVE_NBD_DEVICE
1066         int ret;
1067
1068         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
1069         if (ret != 0) {
1070             error_report("Failed to create client thread: %s", strerror(ret));
1071             exit(EXIT_FAILURE);
1072         }
1073 #endif
1074     } else {
1075         /* Shut up GCC warnings.  */
1076         memset(&client_thread, 0, sizeof(client_thread));
1077     }
1078
1079     nbd_update_server_watch();
1080
1081     if (pid_file_name) {
1082         qemu_write_pidfile(pid_file_name, &error_fatal);
1083     }
1084
1085     /* now when the initialization is (almost) complete, chdir("/")
1086      * to free any busy filesystems */
1087     if (chdir("/") < 0) {
1088         error_report("Could not chdir to root directory: %s",
1089                      strerror(errno));
1090         exit(EXIT_FAILURE);
1091     }
1092
1093     if (fork_process) {
1094         dup2(old_stderr, STDERR_FILENO);
1095         close(old_stderr);
1096     }
1097
1098     state = RUNNING;
1099     do {
1100         main_loop_wait(false);
1101         if (state == TERMINATE) {
1102             state = TERMINATING;
1103             nbd_export_close(export);
1104             nbd_export_put(export);
1105             export = NULL;
1106         }
1107     } while (state != TERMINATED);
1108
1109     blk_unref(blk);
1110     if (sockpath) {
1111         unlink(sockpath);
1112     }
1113
1114     qemu_opts_del(sn_opts);
1115
1116     if (device) {
1117         void *ret;
1118         pthread_join(client_thread, &ret);
1119         exit(ret != NULL);
1120     } else {
1121         exit(EXIT_SUCCESS);
1122     }
1123 }