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 #if HAVE_NBD_DEVICE
 159 static void termsig_handler(int signum)
 160 {
 161     qatomic_cmpxchg(&state, RUNNING, TERMINATE);
 162     qemu_notify_event();
 163 }
 164 #endif /* HAVE_NBD_DEVICE */
 165
 166 static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
 167                                 const char *hostname)
 168 {
 169     int ret = EXIT_FAILURE;
 170     int rc;
 171     Error *err = NULL;
 172     QIOChannelSocket *sioc;
 173     NBDExportInfo *list;
 174     int i, j;
 175
 176     sioc = qio_channel_socket_new();
 177     if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
 178         error_report_err(err);
 179         return EXIT_FAILURE;
 180     }
 181     rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
 182                                  &err);
 183     if (rc < 0) {
 184         if (err) {
 185             error_report_err(err);
 186         }
 187         goto out;
 188     }
 189     printf("exports available: %d\n", rc);
 190     for (i = 0; i < rc; i++) {
 191         printf(" export: '%s'\n", list[i].name);
 192         if (list[i].description && *list[i].description) {
 193             printf("  description: %s\n", list[i].description);
 194         }
 195         if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
 196             static const char *const flag_names[] = {
 197                 [NBD_FLAG_READ_ONLY_BIT]            = "readonly",
 198                 [NBD_FLAG_SEND_FLUSH_BIT]           = "flush",
 199                 [NBD_FLAG_SEND_FUA_BIT]             = "fua",
 200                 [NBD_FLAG_ROTATIONAL_BIT]           = "rotational",
 201                 [NBD_FLAG_SEND_TRIM_BIT]            = "trim",
 202                 [NBD_FLAG_SEND_WRITE_ZEROES_BIT]    = "zeroes",
 203                 [NBD_FLAG_SEND_DF_BIT]              = "df",
 204                 [NBD_FLAG_CAN_MULTI_CONN_BIT]       = "multi",
 205                 [NBD_FLAG_SEND_RESIZE_BIT]          = "resize",
 206                 [NBD_FLAG_SEND_CACHE_BIT]           = "cache",
 207                 [NBD_FLAG_SEND_FAST_ZERO_BIT]       = "fast-zero",
 208             };
 209
 210             printf("  size:  %" PRIu64 "\n", list[i].size);
 211             printf("  flags: 0x%x (", list[i].flags);
 212             for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) {
 213                 if (flag_names[bit] && (list[i].flags & (1 << bit))) {
 214                     printf(" %s", flag_names[bit]);
 215                 }
 216             }
 217             printf(" )\n");
 218         }
 219         if (list[i].min_block) {
 220             printf("  min block: %u\n", list[i].min_block);
 221             printf("  opt block: %u\n", list[i].opt_block);
 222             printf("  max block: %u\n", list[i].max_block);
 223         }
 224         if (list[i].n_contexts) {
 225             printf("  available meta contexts: %d\n", list[i].n_contexts);
 226             for (j = 0; j < list[i].n_contexts; j++) {
 227                 printf("   %s\n", list[i].contexts[j]);
 228             }
 229         }
 230     }
 231     nbd_free_export_list(list, rc);
 232
 233     ret = EXIT_SUCCESS;
 234  out:
 235     object_unref(OBJECT(sioc));
 236     return ret;
 237 }
 238
 239
 240 #if HAVE_NBD_DEVICE
 241 static void *show_parts(void *arg)
 242 {
 243     char *device = arg;
 244     int nbd;
 245
 246     /* linux just needs an open() to trigger
 247      * the partition table update
 248      * but remember to load the module with max_part != 0 :
 249      *     modprobe nbd max_part=63
 250      */
 251     nbd = open(device, O_RDWR);
 252     if (nbd >= 0) {
 253         close(nbd);
 254     }
 255     return NULL;
 256 }
 257
 258 static void *nbd_client_thread(void *arg)
 259 {
 260     char *device = arg;
 261     NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };
 262     QIOChannelSocket *sioc;
 263     int fd;
 264     int ret;
 265     pthread_t show_parts_thread;
 266     Error *local_error = NULL;
 267
 268     sioc = qio_channel_socket_new();
 269     if (qio_channel_socket_connect_sync(sioc,
 270                                         saddr,
 271                                         &local_error) < 0) {
 272         error_report_err(local_error);
 273         goto out;
 274     }
 275
 276     ret = nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc),
 277                                 NULL, NULL, NULL, &info, &local_error);
 278     if (ret < 0) {
 279         if (local_error) {
 280             error_report_err(local_error);
 281         }
 282         goto out_socket;
 283     }
 284
 285     fd = open(device, O_RDWR);
 286     if (fd < 0) {
 287         /* Linux-only, we can use %m in printf.  */
 288         error_report("Failed to open %s: %m", device);
 289         goto out_socket;
 290     }
 291
 292     ret = nbd_init(fd, sioc, &info, &local_error);
 293     if (ret < 0) {
 294         error_report_err(local_error);
 295         goto out_fd;
 296     }
 297
 298     /* update partition table */
 299     pthread_create(&show_parts_thread, NULL, show_parts, device);
 300
 301     if (verbose) {
 302         fprintf(stderr, "NBD device %s is now connected to %s\n",
 303                 device, srcpath);
 304     } else {
 305         /* Close stderr so that the qemu-nbd process exits.  */
 306         dup2(STDOUT_FILENO, STDERR_FILENO);
 307     }
 308
 309     ret = nbd_client(fd);
 310     if (ret) {
 311         goto out_fd;
 312     }
 313     close(fd);
 314     object_unref(OBJECT(sioc));
 315     g_free(info.name);
 316     kill(getpid(), SIGTERM);
 317     return (void *) EXIT_SUCCESS;
 318
 319 out_fd:
 320     close(fd);
 321 out_socket:
 322     object_unref(OBJECT(sioc));
 323 out:
 324     g_free(info.name);
 325     kill(getpid(), SIGTERM);
 326     return (void *) EXIT_FAILURE;
 327 }
 328 #endif /* HAVE_NBD_DEVICE */
 329
 330 static int nbd_can_accept(void)
 331 {
 332     return state == RUNNING && nb_fds < shared;
 333 }
 334
 335 static void nbd_export_closed(NBDExport *export)
 336 {
 337     assert(state == TERMINATING);
 338     state = TERMINATED;
 339 }
 340
 341 static void nbd_update_server_watch(void);
 342
 343 static void nbd_client_closed(NBDClient *client, bool negotiated)
 344 {
 345     nb_fds--;
 346     if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
 347         state = TERMINATE;
 348     }
 349     nbd_update_server_watch();
 350     nbd_client_put(client);
 351 }
 352
 353 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
 354                        gpointer opaque)
 355 {
 356     if (state >= TERMINATE) {
 357         return;
 358     }
 359
 360     nb_fds++;
 361     nbd_update_server_watch();
 362     nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
 363 }
 364
 365 static void nbd_update_server_watch(void)
 366 {
 367     if (nbd_can_accept()) {
 368         qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
 369     } else {
 370         qio_net_listener_set_client_func(server, NULL, NULL, NULL);
 371     }
 372 }
 373
 374
 375 static SocketAddress *nbd_build_socket_address(const char *sockpath,
 376                                                const char *bindto,
 377                                                const char *port)
 378 {
 379     SocketAddress *saddr;
 380
 381     saddr = g_new0(SocketAddress, 1);
 382     if (sockpath) {
 383         saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
 384         saddr->u.q_unix.path = g_strdup(sockpath);
 385     } else {
 386         InetSocketAddress *inet;
 387         saddr->type = SOCKET_ADDRESS_TYPE_INET;
 388         inet = &saddr->u.inet;
 389         inet->host = g_strdup(bindto);
 390         if (port) {
 391             inet->port = g_strdup(port);
 392         } else  {
 393             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 394         }
 395     }
 396
 397     return saddr;
 398 }
 399
 400
 401 static QemuOptsList file_opts = {
 402     .name = "file",
 403     .implied_opt_name = "file",
 404     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
 405     .desc = {
 406         /* no elements => accept any params */
 407         { /* end of list */ }
 408     },
 409 };
 410
 411 static QemuOptsList qemu_object_opts = {
 412     .name = "object",
 413     .implied_opt_name = "qom-type",
 414     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
 415     .desc = {
 416         { }
 417     },
 418 };
 419
 420 static bool qemu_nbd_object_print_help(const char *type, QemuOpts *opts)
 421 {
 422     if (user_creatable_print_help(type, opts)) {
 423         exit(0);
 424     }
 425     return true;
 426 }
 427
 428
 429 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
 430                                           Error **errp)
 431 {
 432     Object *obj;
 433     QCryptoTLSCreds *creds;
 434
 435     obj = object_resolve_path_component(
 436         object_get_objects_root(), id);
 437     if (!obj) {
 438         error_setg(errp, "No TLS credentials with id '%s'",
 439                    id);
 440         return NULL;
 441     }
 442     creds = (QCryptoTLSCreds *)
 443         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 444     if (!creds) {
 445         error_setg(errp, "Object with id '%s' is not TLS credentials",
 446                    id);
 447         return NULL;
 448     }
 449
 450     if (list) {
 451         if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
 452             error_setg(errp,
 453                        "Expecting TLS credentials with a client endpoint");
 454             return NULL;
 455         }
 456     } else {
 457         if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
 458             error_setg(errp,
 459                        "Expecting TLS credentials with a server endpoint");
 460             return NULL;
 461         }
 462     }
 463     object_ref(obj);
 464     return creds;
 465 }
 466
 467 static void setup_address_and_port(const char **address, const char **port)
 468 {
 469     if (*address == NULL) {
 470         *address = "0.0.0.0";
 471     }
 472
 473     if (*port == NULL) {
 474         *port = stringify(NBD_DEFAULT_PORT);
 475     }
 476 }
 477
 478 /*
 479  * Check socket parameters compatibility when socket activation is used.
 480  */
 481 static const char *socket_activation_validate_opts(const char *device,
 482                                                    const char *sockpath,
 483                                                    const char *address,
 484                                                    const char *port,
 485                                                    bool list)
 486 {
 487     if (device != NULL) {
 488         return "NBD device can't be set when using socket activation";
 489     }
 490
 491     if (sockpath != NULL) {
 492         return "Unix socket can't be set when using socket activation";
 493     }
 494
 495     if (address != NULL) {
 496         return "The interface can't be set when using socket activation";
 497     }
 498
 499     if (port != NULL) {
 500         return "TCP port number can't be set when using socket activation";
 501     }
 502
 503     if (list) {
 504         return "List mode is incompatible with socket activation";
 505     }
 506
 507     return NULL;
 508 }
 509
 510 static void qemu_nbd_shutdown(void)
 511 {
 512     job_cancel_sync_all();
 513     bdrv_close_all();
 514 }
 515
 516 int main(int argc, char **argv)
 517 {
 518     BlockBackend *blk;
 519     BlockDriverState *bs;
 520     uint64_t dev_offset = 0;
 521     bool readonly = false;
 522     bool disconnect = false;
 523     const char *bindto = NULL;
 524     const char *port = NULL;
 525     char *sockpath = NULL;
 526     char *device = NULL;
 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 #if HAVE_NBD_DEVICE
 591     /* The client thread uses SIGTERM to interrupt the server.  A signal
 592      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
 593      */
 594     struct sigaction sa_sigterm;
 595     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
 596     sa_sigterm.sa_handler = termsig_handler;
 597     sigaction(SIGTERM, &sa_sigterm, NULL);
 598 #endif /* HAVE_NBD_DEVICE */
 599
 600 #ifdef CONFIG_POSIX
 601     signal(SIGPIPE, SIG_IGN);
 602 #endif
 603
 604     socket_init();
 605     error_init(argv[0]);
 606     module_call_init(MODULE_INIT_TRACE);
 607     qcrypto_init(&error_fatal);
 608
 609     module_call_init(MODULE_INIT_QOM);
 610     qemu_add_opts(&qemu_object_opts);
 611     qemu_add_opts(&qemu_trace_opts);
 612     qemu_init_exec_dir(argv[0]);
 613
 614     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 615         switch (ch) {
 616         case 's':
 617             flags |= BDRV_O_SNAPSHOT;
 618             break;
 619         case 'n':
 620             optarg = (char *) "none";
 621             /* fallthrough */
 622         case QEMU_NBD_OPT_CACHE:
 623             if (seen_cache) {
 624                 error_report("-n and --cache can only be specified once");
 625                 exit(EXIT_FAILURE);
 626             }
 627             seen_cache = true;
 628             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
 629                 error_report("Invalid cache mode `%s'", optarg);
 630                 exit(EXIT_FAILURE);
 631             }
 632             break;
 633         case QEMU_NBD_OPT_AIO:
 634             if (seen_aio) {
 635                 error_report("--aio can only be specified once");
 636                 exit(EXIT_FAILURE);
 637             }
 638             seen_aio = true;
 639             if (bdrv_parse_aio(optarg, &flags) < 0) {
 640                 error_report("Invalid aio mode '%s'", optarg);
 641                 exit(EXIT_FAILURE);
 642             }
 643             break;
 644         case QEMU_NBD_OPT_DISCARD:
 645             if (seen_discard) {
 646                 error_report("--discard can only be specified once");
 647                 exit(EXIT_FAILURE);
 648             }
 649             seen_discard = true;
 650             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 651                 error_report("Invalid discard mode `%s'", optarg);
 652                 exit(EXIT_FAILURE);
 653             }
 654             break;
 655         case QEMU_NBD_OPT_DETECT_ZEROES:
 656             detect_zeroes =
 657                 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
 658                                 optarg,
 659                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
 660                                 &local_err);
 661             if (local_err) {
 662                 error_reportf_err(local_err,
 663                                   "Failed to parse detect_zeroes mode: ");
 664                 exit(EXIT_FAILURE);
 665             }
 666             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
 667                 !(flags & BDRV_O_UNMAP)) {
 668                 error_report("setting detect-zeroes to unmap is not allowed "
 669                              "without setting discard operation to unmap");
 670                 exit(EXIT_FAILURE);
 671             }
 672             break;
 673         case 'b':
 674             bindto = optarg;
 675             break;
 676         case 'p':
 677             port = optarg;
 678             break;
 679         case 'o':
 680             if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
 681                 error_report("Invalid offset '%s'", optarg);
 682                 exit(EXIT_FAILURE);
 683             }
 684             break;
 685         case 'l':
 686             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 687                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
 688                                                   optarg, false);
 689                 if (!sn_opts) {
 690                     error_report("Failed in parsing snapshot param `%s'",
 691                                  optarg);
 692                     exit(EXIT_FAILURE);
 693                 }
 694             } else {
 695                 sn_id_or_name = optarg;
 696             }
 697             /* fall through */
 698         case 'r':
 699             readonly = true;
 700             flags &= ~BDRV_O_RDWR;
 701             break;
 702         case 'B':
 703             bitmap = optarg;
 704             break;
 705         case 'k':
 706             sockpath = optarg;
 707             if (sockpath[0] != '/') {
 708                 error_report("socket path must be absolute");
 709                 exit(EXIT_FAILURE);
 710             }
 711             break;
 712         case 'd':
 713             disconnect = true;
 714             break;
 715         case 'c':
 716             device = optarg;
 717             break;
 718         case 'e':
 719             if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
 720                 shared < 1) {
 721                 error_report("Invalid shared device number '%s'", optarg);
 722                 exit(EXIT_FAILURE);
 723             }
 724             break;
 725         case 'f':
 726             fmt = optarg;
 727             break;
 728         case 't':
 729             persistent = 1;
 730             break;
 731         case 'x':
 732             export_name = optarg;
 733             if (strlen(export_name) > NBD_MAX_STRING_SIZE) {
 734                 error_report("export name '%s' too long", export_name);
 735                 exit(EXIT_FAILURE);
 736             }
 737             break;
 738         case 'D':
 739             export_description = optarg;
 740             if (strlen(export_description) > NBD_MAX_STRING_SIZE) {
 741                 error_report("export description '%s' too long",
 742                              export_description);
 743                 exit(EXIT_FAILURE);
 744             }
 745             break;
 746         case 'v':
 747             verbose = 1;
 748             break;
 749         case 'V':
 750             version(argv[0]);
 751             exit(0);
 752             break;
 753         case 'h':
 754             usage(argv[0]);
 755             exit(0);
 756             break;
 757         case '?':
 758             error_report("Try `%s --help' for more information.", argv[0]);
 759             exit(EXIT_FAILURE);
 760         case QEMU_NBD_OPT_OBJECT: {
 761             QemuOpts *opts;
 762             opts = qemu_opts_parse_noisily(&qemu_object_opts,
 763                                            optarg, true);
 764             if (!opts) {
 765                 exit(EXIT_FAILURE);
 766             }
 767         }   break;
 768         case QEMU_NBD_OPT_TLSCREDS:
 769             tlscredsid = optarg;
 770             break;
 771         case QEMU_NBD_OPT_IMAGE_OPTS:
 772             imageOpts = true;
 773             break;
 774         case 'T':
 775             g_free(trace_file);
 776             trace_file = trace_opt_parse(optarg);
 777             break;
 778         case QEMU_NBD_OPT_TLSAUTHZ:
 779             tlsauthz = optarg;
 780             break;
 781         case QEMU_NBD_OPT_FORK:
 782             fork_process = true;
 783             break;
 784         case 'L':
 785             list = true;
 786             break;
 787         case QEMU_NBD_OPT_PID_FILE:
 788             pid_file_name = optarg;
 789             break;
 790         }
 791     }
 792
 793     if (list) {
 794         if (argc != optind) {
 795             error_report("List mode is incompatible with a file name");
 796             exit(EXIT_FAILURE);
 797         }
 798         if (export_name || export_description || dev_offset ||
 799             device || disconnect || fmt || sn_id_or_name || bitmap ||
 800             seen_aio || seen_discard || seen_cache) {
 801             error_report("List mode is incompatible with per-device settings");
 802             exit(EXIT_FAILURE);
 803         }
 804         if (fork_process) {
 805             error_report("List mode is incompatible with forking");
 806             exit(EXIT_FAILURE);
 807         }
 808     } else if ((argc - optind) != 1) {
 809         error_report("Invalid number of arguments");
 810         error_printf("Try `%s --help' for more information.\n", argv[0]);
 811         exit(EXIT_FAILURE);
 812     } else if (!export_name) {
 813         export_name = "";
 814     }
 815
 816     qemu_opts_foreach(&qemu_object_opts,
 817                       user_creatable_add_opts_foreach,
 818                       qemu_nbd_object_print_help, &error_fatal);
 819
 820     if (!trace_init_backends()) {
 821         exit(1);
 822     }
 823     trace_init_file(trace_file);
 824     qemu_set_log(LOG_TRACE);
 825
 826     socket_activation = check_socket_activation();
 827     if (socket_activation == 0) {
 828         setup_address_and_port(&bindto, &port);
 829     } else {
 830         /* Using socket activation - check user didn't use -p etc. */
 831         const char *err_msg = socket_activation_validate_opts(device, sockpath,
 832                                                               bindto, port,
 833                                                               list);
 834         if (err_msg != NULL) {
 835             error_report("%s", err_msg);
 836             exit(EXIT_FAILURE);
 837         }
 838
 839         /* qemu-nbd can only listen on a single socket.  */
 840         if (socket_activation > 1) {
 841             error_report("qemu-nbd does not support socket activation with %s > 1",
 842                          "LISTEN_FDS");
 843             exit(EXIT_FAILURE);
 844         }
 845     }
 846
 847     if (tlscredsid) {
 848         if (sockpath) {
 849             error_report("TLS is only supported with IPv4/IPv6");
 850             exit(EXIT_FAILURE);
 851         }
 852         if (device) {
 853             error_report("TLS is not supported with a host device");
 854             exit(EXIT_FAILURE);
 855         }
 856         if (tlsauthz && list) {
 857             error_report("TLS authorization is incompatible with export list");
 858             exit(EXIT_FAILURE);
 859         }
 860         tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
 861         if (local_err) {
 862             error_reportf_err(local_err, "Failed to get TLS creds: ");
 863             exit(EXIT_FAILURE);
 864         }
 865     } else {
 866         if (tlsauthz) {
 867             error_report("--tls-authz is not permitted without --tls-creds");
 868             exit(EXIT_FAILURE);
 869         }
 870     }
 871
 872     if (list) {
 873         saddr = nbd_build_socket_address(sockpath, bindto, port);
 874         return qemu_nbd_client_list(saddr, tlscreds, bindto);
 875     }
 876
 877 #if !HAVE_NBD_DEVICE
 878     if (disconnect || device) {
 879         error_report("Kernel /dev/nbdN support not available");
 880         exit(EXIT_FAILURE);
 881     }
 882 #else /* HAVE_NBD_DEVICE */
 883     if (disconnect) {
 884         int nbdfd = open(argv[optind], O_RDWR);
 885         if (nbdfd < 0) {
 886             error_report("Cannot open %s: %s", argv[optind],
 887                          strerror(errno));
 888             exit(EXIT_FAILURE);
 889         }
 890         nbd_disconnect(nbdfd);
 891
 892         close(nbdfd);
 893
 894         printf("%s disconnected\n", argv[optind]);
 895
 896         return 0;
 897     }
 898 #endif
 899
 900     if ((device && !verbose) || fork_process) {
 901 #ifndef WIN32
 902         int stderr_fd[2];
 903         pid_t pid;
 904         int ret;
 905
 906         if (qemu_pipe(stderr_fd) < 0) {
 907             error_report("Error setting up communication pipe: %s",
 908                          strerror(errno));
 909             exit(EXIT_FAILURE);
 910         }
 911
 912         /* Now daemonize, but keep a communication channel open to
 913          * print errors and exit with the proper status code.
 914          */
 915         pid = fork();
 916         if (pid < 0) {
 917             error_report("Failed to fork: %s", strerror(errno));
 918             exit(EXIT_FAILURE);
 919         } else if (pid == 0) {
 920             close(stderr_fd[0]);
 921
 922             /* Remember parent's stderr if we will be restoring it. */
 923             if (fork_process) {
 924                 old_stderr = dup(STDERR_FILENO);
 925             }
 926
 927             ret = qemu_daemon(1, 0);
 928
 929             /* Temporarily redirect stderr to the parent's pipe...  */
 930             dup2(stderr_fd[1], STDERR_FILENO);
 931             if (ret < 0) {
 932                 error_report("Failed to daemonize: %s", strerror(errno));
 933                 exit(EXIT_FAILURE);
 934             }
 935
 936             /* ... close the descriptor we inherited and go on.  */
 937             close(stderr_fd[1]);
 938         } else {
 939             bool errors = false;
 940             char *buf;
 941
 942             /* In the parent.  Print error messages from the child until
 943              * it closes the pipe.
 944              */
 945             close(stderr_fd[1]);
 946             buf = g_malloc(1024);
 947             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
 948                 errors = true;
 949                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
 950                 if (ret < 0) {
 951                     exit(EXIT_FAILURE);
 952                 }
 953             }
 954             if (ret < 0) {
 955                 error_report("Cannot read from daemon: %s",
 956                              strerror(errno));
 957                 exit(EXIT_FAILURE);
 958             }
 959
 960             /* Usually the daemon should not print any message.
 961              * Exit with zero status in that case.
 962              */
 963             exit(errors);
 964         }
 965 #else /* WIN32 */
 966         error_report("Unable to fork into background on Windows hosts");
 967         exit(EXIT_FAILURE);
 968 #endif /* WIN32 */
 969     }
 970
 971     if (device != NULL && sockpath == NULL) {
 972         sockpath = g_malloc(128);
 973         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
 974     }
 975
 976     server = qio_net_listener_new();
 977     if (socket_activation == 0) {
 978         saddr = nbd_build_socket_address(sockpath, bindto, port);
 979         if (qio_net_listener_open_sync(server, saddr, 1, &local_err) < 0) {
 980             object_unref(OBJECT(server));
 981             error_report_err(local_err);
 982             exit(EXIT_FAILURE);
 983         }
 984     } else {
 985         size_t i;
 986         /* See comment in check_socket_activation above. */
 987         for (i = 0; i < socket_activation; i++) {
 988             QIOChannelSocket *sioc;
 989             sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
 990                                              &local_err);
 991             if (sioc == NULL) {
 992                 object_unref(OBJECT(server));
 993                 error_reportf_err(local_err,
 994                                   "Failed to use socket activation: ");
 995                 exit(EXIT_FAILURE);
 996             }
 997             qio_net_listener_add(server, sioc);
 998             object_unref(OBJECT(sioc));
 999         }
1000     }
1001
1002     if (qemu_init_main_loop(&local_err)) {
1003         error_report_err(local_err);
1004         exit(EXIT_FAILURE);
1005     }
1006     bdrv_init();
1007     atexit(qemu_nbd_shutdown);
1008
1009     srcpath = argv[optind];
1010     if (imageOpts) {
1011         QemuOpts *opts;
1012         if (fmt) {
1013             error_report("--image-opts and -f are mutually exclusive");
1014             exit(EXIT_FAILURE);
1015         }
1016         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
1017         if (!opts) {
1018             qemu_opts_reset(&file_opts);
1019             exit(EXIT_FAILURE);
1020         }
1021         options = qemu_opts_to_qdict(opts, NULL);
1022         qemu_opts_reset(&file_opts);
1023         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
1024     } else {
1025         if (fmt) {
1026             options = qdict_new();
1027             qdict_put_str(options, "driver", fmt);
1028         }
1029         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
1030     }
1031
1032     if (!blk) {
1033         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
1034                           argv[optind]);
1035         exit(EXIT_FAILURE);
1036     }
1037     bs = blk_bs(blk);
1038
1039     if (dev_offset) {
1040         QDict *raw_opts = qdict_new();
1041         qdict_put_str(raw_opts, "driver", "raw");
1042         qdict_put_str(raw_opts, "file", bs->node_name);
1043         qdict_put_int(raw_opts, "offset", dev_offset);
1044         bs = bdrv_open(NULL, NULL, raw_opts, flags, &error_fatal);
1045         blk_remove_bs(blk);
1046         blk_insert_bs(blk, bs, &error_fatal);
1047         bdrv_unref(bs);
1048     }
1049
1050     blk_set_enable_write_cache(blk, !writethrough);
1051
1052     if (sn_opts) {
1053         ret = bdrv_snapshot_load_tmp(bs,
1054                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1055                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1056                                      &local_err);
1057     } else if (sn_id_or_name) {
1058         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1059                                                    &local_err);
1060     }
1061     if (ret < 0) {
1062         error_reportf_err(local_err, "Failed to load snapshot: ");
1063         exit(EXIT_FAILURE);
1064     }
1065
1066     bs->detect_zeroes = detect_zeroes;
1067
1068     export = nbd_export_new(bs, export_name,
1069                             export_description, bitmap, readonly, shared > 1,
1070                             nbd_export_closed, writethrough, NULL,
1071                             &error_fatal);
1072
1073     if (device) {
1074 #if HAVE_NBD_DEVICE
1075         int ret;
1076
1077         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
1078         if (ret != 0) {
1079             error_report("Failed to create client thread: %s", strerror(ret));
1080             exit(EXIT_FAILURE);
1081         }
1082 #endif
1083     } else {
1084         /* Shut up GCC warnings.  */
1085         memset(&client_thread, 0, sizeof(client_thread));
1086     }
1087
1088     nbd_update_server_watch();
1089
1090     if (pid_file_name) {
1091         qemu_write_pidfile(pid_file_name, &error_fatal);
1092     }
1093
1094     /* now when the initialization is (almost) complete, chdir("/")
1095      * to free any busy filesystems */
1096     if (chdir("/") < 0) {
1097         error_report("Could not chdir to root directory: %s",
1098                      strerror(errno));
1099         exit(EXIT_FAILURE);
1100     }
1101
1102     if (fork_process) {
1103         dup2(old_stderr, STDERR_FILENO);
1104         close(old_stderr);
1105     }
1106
1107     state = RUNNING;
1108     do {
1109         main_loop_wait(false);
1110         if (state == TERMINATE) {
1111             state = TERMINATING;
1112             nbd_export_close(export);
1113             nbd_export_put(export);
1114             export = NULL;
1115         }
1116     } while (state != TERMINATED);
1117
1118     blk_unref(blk);
1119     if (sockpath) {
1120         unlink(sockpath);
1121     }
1122
1123     qemu_opts_del(sn_opts);
1124
1125     if (device) {
1126         void *ret;
1127         pthread_join(client_thread, &ret);
1128         exit(ret != NULL);
1129     } else {
1130         exit(EXIT_SUCCESS);
1131     }
1132 }