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 "qapi/error.h"
  25 #include "qemu/cutils.h"
  26 #include "sysemu/block-backend.h"
  27 #include "block/block_int.h"
  28 #include "block/nbd.h"
  29 #include "qemu/main-loop.h"
  30 #include "qemu/option.h"
  31 #include "qemu/error-report.h"
  32 #include "qemu/config-file.h"
  33 #include "qemu/bswap.h"
  34 #include "qemu/log.h"
  35 #include "qemu/systemd.h"
  36 #include "block/snapshot.h"
  37 #include "qapi/qmp/qdict.h"
  38 #include "qapi/qmp/qstring.h"
  39 #include "qom/object_interfaces.h"
  40 #include "io/channel-socket.h"
  41 #include "io/net-listener.h"
  42 #include "crypto/init.h"
  43 #include "trace/control.h"
  44 #include "qemu-version.h"
  45
  46 #ifdef __linux__
  47 #define HAVE_NBD_DEVICE 1
  48 #else
  49 #define HAVE_NBD_DEVICE 0
  50 #endif
  51
  52 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
  53 #define QEMU_NBD_OPT_CACHE         256
  54 #define QEMU_NBD_OPT_AIO           257
  55 #define QEMU_NBD_OPT_DISCARD       258
  56 #define QEMU_NBD_OPT_DETECT_ZEROES 259
  57 #define QEMU_NBD_OPT_OBJECT        260
  58 #define QEMU_NBD_OPT_TLSCREDS      261
  59 #define QEMU_NBD_OPT_IMAGE_OPTS    262
  60 #define QEMU_NBD_OPT_FORK          263
  61
  62 #define MBR_SIZE 512
  63
  64 static NBDExport *export;
  65 static int verbose;
  66 static char *srcpath;
  67 static SocketAddress *saddr;
  68 static int persistent = 0;
  69 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
  70 static int shared = 1;
  71 static int nb_fds;
  72 static QIONetListener *server;
  73 static QCryptoTLSCreds *tlscreds;
  74
  75 static void usage(const char *name)
  76 {
  77     (printf) (
  78 "Usage: %s [OPTIONS] FILE\n"
  79 "QEMU Disk Network Block Device Server\n"
  80 "\n"
  81 "  -h, --help                display this help and exit\n"
  82 "  -V, --version             output version information and exit\n"
  83 "\n"
  84 "Connection properties:\n"
  85 "  -p, --port=PORT           port to listen on (default `%d')\n"
  86 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
  87 "  -k, --socket=PATH         path to the unix socket\n"
  88 "                            (default '"SOCKET_PATH"')\n"
  89 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
  90 "  -t, --persistent          don't exit on the last connection\n"
  91 "  -v, --verbose             display extra debugging information\n"
  92 "  -x, --export-name=NAME    expose export by name (default is empty string)\n"
  93 "  -D, --description=TEXT    export a human-readable description\n"
  94 "\n"
  95 "Exposing part of the image:\n"
  96 "  -o, --offset=OFFSET       offset into the image\n"
  97 "  -P, --partition=NUM       only expose partition NUM\n"
  98 "  -B, --bitmap=NAME         expose a persistent dirty bitmap\n"
  99 "\n"
 100 "General purpose options:\n"
 101 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
 102 "                            passwords and/or encryption keys\n"
 103 "  --tls-creds=ID            use id of an earlier --object to provide TLS\n"
 104 "  -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
 105 "                            specify tracing options\n"
 106 "  --fork                    fork off the server process and exit the parent\n"
 107 "                            once the server is running\n"
 108 #if HAVE_NBD_DEVICE
 109 "\n"
 110 "Kernel NBD client support:\n"
 111 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
 112 "  -d, --disconnect          disconnect the specified device\n"
 113 #endif
 114 "\n"
 115 "Block device options:\n"
 116 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
 117 "  -r, --read-only           export read-only\n"
 118 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
 119 "                            file with backing_file=FILE, redirect the write to\n"
 120 "                            the temporary one\n"
 121 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
 122 "                            load an internal snapshot inside FILE and export it\n"
 123 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
 124 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
 125 "                            '[ID_OR_NAME]'\n"
 126 "  -n, --nocache             disable host cache\n"
 127 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
 128 "      --aio=MODE            set AIO mode (native or threads)\n"
 129 "      --discard=MODE        set discard mode (ignore, unmap)\n"
 130 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
 131 "      --image-opts          treat FILE as a full set of image options\n"
 132 "\n"
 133 QEMU_HELP_BOTTOM "\n"
 134     , name, NBD_DEFAULT_PORT, "DEVICE");
 135 }
 136
 137 static void version(const char *name)
 138 {
 139     printf(
 140 "%s " QEMU_FULL_VERSION "\n"
 141 "Written by Anthony Liguori.\n"
 142 "\n"
 143 QEMU_COPYRIGHT "\n"
 144 "This is free software; see the source for copying conditions.  There is NO\n"
 145 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
 146     , name);
 147 }
 148
 149 struct partition_record
 150 {
 151     uint8_t bootable;
 152     uint8_t start_head;
 153     uint32_t start_cylinder;
 154     uint8_t start_sector;
 155     uint8_t system;
 156     uint8_t end_head;
 157     uint8_t end_cylinder;
 158     uint8_t end_sector;
 159     uint32_t start_sector_abs;
 160     uint32_t nb_sectors_abs;
 161 };
 162
 163 static void read_partition(uint8_t *p, struct partition_record *r)
 164 {
 165     r->bootable = p[0];
 166     r->start_head = p[1];
 167     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
 168     r->start_sector = p[2] & 0x3f;
 169     r->system = p[4];
 170     r->end_head = p[5];
 171     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
 172     r->end_sector = p[6] & 0x3f;
 173
 174     r->start_sector_abs = ldl_le_p(p + 8);
 175     r->nb_sectors_abs   = ldl_le_p(p + 12);
 176 }
 177
 178 static int find_partition(BlockBackend *blk, int partition,
 179                           off_t *offset, off_t *size)
 180 {
 181     struct partition_record mbr[4];
 182     uint8_t data[MBR_SIZE];
 183     int i;
 184     int ext_partnum = 4;
 185     int ret;
 186
 187     ret = blk_pread(blk, 0, data, sizeof(data));
 188     if (ret < 0) {
 189         error_report("error while reading: %s", strerror(-ret));
 190         exit(EXIT_FAILURE);
 191     }
 192
 193     if (data[510] != 0x55 || data[511] != 0xaa) {
 194         return -EINVAL;
 195     }
 196
 197     for (i = 0; i < 4; i++) {
 198         read_partition(&data[446 + 16 * i], &mbr[i]);
 199
 200         if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
 201             continue;
 202         }
 203
 204         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
 205             struct partition_record ext[4];
 206             uint8_t data1[MBR_SIZE];
 207             int j;
 208
 209             ret = blk_pread(blk, mbr[i].start_sector_abs * MBR_SIZE,
 210                             data1, sizeof(data1));
 211             if (ret < 0) {
 212                 error_report("error while reading: %s", strerror(-ret));
 213                 exit(EXIT_FAILURE);
 214             }
 215
 216             for (j = 0; j < 4; j++) {
 217                 read_partition(&data1[446 + 16 * j], &ext[j]);
 218                 if (!ext[j].system || !ext[j].nb_sectors_abs) {
 219                     continue;
 220                 }
 221
 222                 if ((ext_partnum + j + 1) == partition) {
 223                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
 224                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
 225                     return 0;
 226                 }
 227             }
 228             ext_partnum += 4;
 229         } else if ((i + 1) == partition) {
 230             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
 231             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
 232             return 0;
 233         }
 234     }
 235
 236     return -ENOENT;
 237 }
 238
 239 static void termsig_handler(int signum)
 240 {
 241     atomic_cmpxchg(&state, RUNNING, TERMINATE);
 242     qemu_notify_event();
 243 }
 244
 245
 246 #if HAVE_NBD_DEVICE
 247 static void *show_parts(void *arg)
 248 {
 249     char *device = arg;
 250     int nbd;
 251
 252     /* linux just needs an open() to trigger
 253      * the partition table update
 254      * but remember to load the module with max_part != 0 :
 255      *     modprobe nbd max_part=63
 256      */
 257     nbd = open(device, O_RDWR);
 258     if (nbd >= 0) {
 259         close(nbd);
 260     }
 261     return NULL;
 262 }
 263
 264 static void *nbd_client_thread(void *arg)
 265 {
 266     char *device = arg;
 267     NBDExportInfo info = { .request_sizes = false, };
 268     QIOChannelSocket *sioc;
 269     int fd;
 270     int ret;
 271     pthread_t show_parts_thread;
 272     Error *local_error = NULL;
 273
 274     sioc = qio_channel_socket_new();
 275     if (qio_channel_socket_connect_sync(sioc,
 276                                         saddr,
 277                                         &local_error) < 0) {
 278         error_report_err(local_error);
 279         goto out;
 280     }
 281
 282     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL,
 283                                 NULL, NULL, NULL, &info, &local_error);
 284     if (ret < 0) {
 285         if (local_error) {
 286             error_report_err(local_error);
 287         }
 288         goto out_socket;
 289     }
 290
 291     fd = open(device, O_RDWR);
 292     if (fd < 0) {
 293         /* Linux-only, we can use %m in printf.  */
 294         error_report("Failed to open %s: %m", device);
 295         goto out_socket;
 296     }
 297
 298     ret = nbd_init(fd, sioc, &info, &local_error);
 299     if (ret < 0) {
 300         error_report_err(local_error);
 301         goto out_fd;
 302     }
 303
 304     /* update partition table */
 305     pthread_create(&show_parts_thread, NULL, show_parts, device);
 306
 307     if (verbose) {
 308         fprintf(stderr, "NBD device %s is now connected to %s\n",
 309                 device, srcpath);
 310     } else {
 311         /* Close stderr so that the qemu-nbd process exits.  */
 312         dup2(STDOUT_FILENO, STDERR_FILENO);
 313     }
 314
 315     ret = nbd_client(fd);
 316     if (ret) {
 317         goto out_fd;
 318     }
 319     close(fd);
 320     object_unref(OBJECT(sioc));
 321     kill(getpid(), SIGTERM);
 322     return (void *) EXIT_SUCCESS;
 323
 324 out_fd:
 325     close(fd);
 326 out_socket:
 327     object_unref(OBJECT(sioc));
 328 out:
 329     kill(getpid(), SIGTERM);
 330     return (void *) EXIT_FAILURE;
 331 }
 332 #endif /* HAVE_NBD_DEVICE */
 333
 334 static int nbd_can_accept(void)
 335 {
 336     return state == RUNNING && nb_fds < shared;
 337 }
 338
 339 static void nbd_export_closed(NBDExport *export)
 340 {
 341     assert(state == TERMINATING);
 342     state = TERMINATED;
 343 }
 344
 345 static void nbd_update_server_watch(void);
 346
 347 static void nbd_client_closed(NBDClient *client, bool negotiated)
 348 {
 349     nb_fds--;
 350     if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
 351         state = TERMINATE;
 352     }
 353     nbd_update_server_watch();
 354     nbd_client_put(client);
 355 }
 356
 357 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
 358                        gpointer opaque)
 359 {
 360     if (state >= TERMINATE) {
 361         return;
 362     }
 363
 364     nb_fds++;
 365     nbd_update_server_watch();
 366     nbd_client_new(cioc, tlscreds, NULL, nbd_client_closed);
 367 }
 368
 369 static void nbd_update_server_watch(void)
 370 {
 371     if (nbd_can_accept()) {
 372         qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
 373     } else {
 374         qio_net_listener_set_client_func(server, NULL, NULL, NULL);
 375     }
 376 }
 377
 378
 379 static SocketAddress *nbd_build_socket_address(const char *sockpath,
 380                                                const char *bindto,
 381                                                const char *port)
 382 {
 383     SocketAddress *saddr;
 384
 385     saddr = g_new0(SocketAddress, 1);
 386     if (sockpath) {
 387         saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
 388         saddr->u.q_unix.path = g_strdup(sockpath);
 389     } else {
 390         InetSocketAddress *inet;
 391         saddr->type = SOCKET_ADDRESS_TYPE_INET;
 392         inet = &saddr->u.inet;
 393         inet->host = g_strdup(bindto);
 394         if (port) {
 395             inet->port = g_strdup(port);
 396         } else  {
 397             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 398         }
 399     }
 400
 401     return saddr;
 402 }
 403
 404
 405 static QemuOptsList file_opts = {
 406     .name = "file",
 407     .implied_opt_name = "file",
 408     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
 409     .desc = {
 410         /* no elements => accept any params */
 411         { /* end of list */ }
 412     },
 413 };
 414
 415 static QemuOptsList qemu_object_opts = {
 416     .name = "object",
 417     .implied_opt_name = "qom-type",
 418     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
 419     .desc = {
 420         { }
 421     },
 422 };
 423
 424
 425
 426 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
 427 {
 428     Object *obj;
 429     QCryptoTLSCreds *creds;
 430
 431     obj = object_resolve_path_component(
 432         object_get_objects_root(), id);
 433     if (!obj) {
 434         error_setg(errp, "No TLS credentials with id '%s'",
 435                    id);
 436         return NULL;
 437     }
 438     creds = (QCryptoTLSCreds *)
 439         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 440     if (!creds) {
 441         error_setg(errp, "Object with id '%s' is not TLS credentials",
 442                    id);
 443         return NULL;
 444     }
 445
 446     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
 447         error_setg(errp,
 448                    "Expecting TLS credentials with a server endpoint");
 449         return NULL;
 450     }
 451     object_ref(obj);
 452     return creds;
 453 }
 454
 455 static void setup_address_and_port(const char **address, const char **port)
 456 {
 457     if (*address == NULL) {
 458         *address = "0.0.0.0";
 459     }
 460
 461     if (*port == NULL) {
 462         *port = stringify(NBD_DEFAULT_PORT);
 463     }
 464 }
 465
 466 /*
 467  * Check socket parameters compatibility when socket activation is used.
 468  */
 469 static const char *socket_activation_validate_opts(const char *device,
 470                                                    const char *sockpath,
 471                                                    const char *address,
 472                                                    const char *port)
 473 {
 474     if (device != NULL) {
 475         return "NBD device can't be set when using socket activation";
 476     }
 477
 478     if (sockpath != NULL) {
 479         return "Unix socket can't be set when using socket activation";
 480     }
 481
 482     if (address != NULL) {
 483         return "The interface can't be set when using socket activation";
 484     }
 485
 486     if (port != NULL) {
 487         return "TCP port number can't be set when using socket activation";
 488     }
 489
 490     return NULL;
 491 }
 492
 493 static void qemu_nbd_shutdown(void)
 494 {
 495     job_cancel_sync_all();
 496     bdrv_close_all();
 497 }
 498
 499 int main(int argc, char **argv)
 500 {
 501     BlockBackend *blk;
 502     BlockDriverState *bs;
 503     off_t dev_offset = 0;
 504     uint16_t nbdflags = 0;
 505     bool disconnect = false;
 506     const char *bindto = NULL;
 507     const char *port = NULL;
 508     char *sockpath = NULL;
 509     char *device = NULL;
 510     off_t fd_size;
 511     QemuOpts *sn_opts = NULL;
 512     const char *sn_id_or_name = NULL;
 513     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:";
 514     struct option lopt[] = {
 515         { "help", no_argument, NULL, 'h' },
 516         { "version", no_argument, NULL, 'V' },
 517         { "bind", required_argument, NULL, 'b' },
 518         { "port", required_argument, NULL, 'p' },
 519         { "socket", required_argument, NULL, 'k' },
 520         { "offset", required_argument, NULL, 'o' },
 521         { "read-only", no_argument, NULL, 'r' },
 522         { "partition", required_argument, NULL, 'P' },
 523         { "bitmap", required_argument, NULL, 'B' },
 524         { "connect", required_argument, NULL, 'c' },
 525         { "disconnect", no_argument, NULL, 'd' },
 526         { "snapshot", no_argument, NULL, 's' },
 527         { "load-snapshot", required_argument, NULL, 'l' },
 528         { "nocache", no_argument, NULL, 'n' },
 529         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
 530         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
 531         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
 532         { "detect-zeroes", required_argument, NULL,
 533           QEMU_NBD_OPT_DETECT_ZEROES },
 534         { "shared", required_argument, NULL, 'e' },
 535         { "format", required_argument, NULL, 'f' },
 536         { "persistent", no_argument, NULL, 't' },
 537         { "verbose", no_argument, NULL, 'v' },
 538         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
 539         { "export-name", required_argument, NULL, 'x' },
 540         { "description", required_argument, NULL, 'D' },
 541         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
 542         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
 543         { "trace", required_argument, NULL, 'T' },
 544         { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
 545         { NULL, 0, NULL, 0 }
 546     };
 547     int ch;
 548     int opt_ind = 0;
 549     char *end;
 550     int flags = BDRV_O_RDWR;
 551     int partition = -1;
 552     int ret = 0;
 553     bool seen_cache = false;
 554     bool seen_discard = false;
 555     bool seen_aio = false;
 556     pthread_t client_thread;
 557     const char *fmt = NULL;
 558     Error *local_err = NULL;
 559     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
 560     QDict *options = NULL;
 561     const char *export_name = ""; /* Default export name */
 562     const char *export_description = NULL;
 563     const char *bitmap = NULL;
 564     const char *tlscredsid = NULL;
 565     bool imageOpts = false;
 566     bool writethrough = true;
 567     char *trace_file = NULL;
 568     bool fork_process = false;
 569     int old_stderr = -1;
 570     unsigned socket_activation;
 571
 572     /* The client thread uses SIGTERM to interrupt the server.  A signal
 573      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
 574      */
 575     struct sigaction sa_sigterm;
 576     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
 577     sa_sigterm.sa_handler = termsig_handler;
 578     sigaction(SIGTERM, &sa_sigterm, NULL);
 579
 580 #ifdef CONFIG_POSIX
 581     signal(SIGPIPE, SIG_IGN);
 582 #endif
 583
 584     module_call_init(MODULE_INIT_TRACE);
 585     error_set_progname(argv[0]);
 586     qcrypto_init(&error_fatal);
 587
 588     module_call_init(MODULE_INIT_QOM);
 589     qemu_add_opts(&qemu_object_opts);
 590     qemu_add_opts(&qemu_trace_opts);
 591     qemu_init_exec_dir(argv[0]);
 592
 593     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 594         switch (ch) {
 595         case 's':
 596             flags |= BDRV_O_SNAPSHOT;
 597             break;
 598         case 'n':
 599             optarg = (char *) "none";
 600             /* fallthrough */
 601         case QEMU_NBD_OPT_CACHE:
 602             if (seen_cache) {
 603                 error_report("-n and --cache can only be specified once");
 604                 exit(EXIT_FAILURE);
 605             }
 606             seen_cache = true;
 607             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
 608                 error_report("Invalid cache mode `%s'", optarg);
 609                 exit(EXIT_FAILURE);
 610             }
 611             break;
 612         case QEMU_NBD_OPT_AIO:
 613             if (seen_aio) {
 614                 error_report("--aio can only be specified once");
 615                 exit(EXIT_FAILURE);
 616             }
 617             seen_aio = true;
 618             if (!strcmp(optarg, "native")) {
 619                 flags |= BDRV_O_NATIVE_AIO;
 620             } else if (!strcmp(optarg, "threads")) {
 621                 /* this is the default */
 622             } else {
 623                error_report("invalid aio mode `%s'", optarg);
 624                exit(EXIT_FAILURE);
 625             }
 626             break;
 627         case QEMU_NBD_OPT_DISCARD:
 628             if (seen_discard) {
 629                 error_report("--discard can only be specified once");
 630                 exit(EXIT_FAILURE);
 631             }
 632             seen_discard = true;
 633             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 634                 error_report("Invalid discard mode `%s'", optarg);
 635                 exit(EXIT_FAILURE);
 636             }
 637             break;
 638         case QEMU_NBD_OPT_DETECT_ZEROES:
 639             detect_zeroes =
 640                 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
 641                                 optarg,
 642                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
 643                                 &local_err);
 644             if (local_err) {
 645                 error_reportf_err(local_err,
 646                                   "Failed to parse detect_zeroes mode: ");
 647                 exit(EXIT_FAILURE);
 648             }
 649             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
 650                 !(flags & BDRV_O_UNMAP)) {
 651                 error_report("setting detect-zeroes to unmap is not allowed "
 652                              "without setting discard operation to unmap");
 653                 exit(EXIT_FAILURE);
 654             }
 655             break;
 656         case 'b':
 657             bindto = optarg;
 658             break;
 659         case 'p':
 660             port = optarg;
 661             break;
 662         case 'o':
 663                 dev_offset = strtoll (optarg, &end, 0);
 664             if (*end) {
 665                 error_report("Invalid offset `%s'", optarg);
 666                 exit(EXIT_FAILURE);
 667             }
 668             if (dev_offset < 0) {
 669                 error_report("Offset must be positive `%s'", optarg);
 670                 exit(EXIT_FAILURE);
 671             }
 672             break;
 673         case 'l':
 674             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 675                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
 676                                                   optarg, false);
 677                 if (!sn_opts) {
 678                     error_report("Failed in parsing snapshot param `%s'",
 679                                  optarg);
 680                     exit(EXIT_FAILURE);
 681                 }
 682             } else {
 683                 sn_id_or_name = optarg;
 684             }
 685             /* fall through */
 686         case 'r':
 687             nbdflags |= NBD_FLAG_READ_ONLY;
 688             flags &= ~BDRV_O_RDWR;
 689             break;
 690         case 'P':
 691             partition = strtol(optarg, &end, 0);
 692             if (*end) {
 693                 error_report("Invalid partition `%s'", optarg);
 694                 exit(EXIT_FAILURE);
 695             }
 696             if (partition < 1 || partition > 8) {
 697                 error_report("Invalid partition %d", partition);
 698                 exit(EXIT_FAILURE);
 699             }
 700             break;
 701         case 'B':
 702             bitmap = optarg;
 703             break;
 704         case 'k':
 705             sockpath = optarg;
 706             if (sockpath[0] != '/') {
 707                 error_report("socket path must be absolute");
 708                 exit(EXIT_FAILURE);
 709             }
 710             break;
 711         case 'd':
 712             disconnect = true;
 713             break;
 714         case 'c':
 715             device = optarg;
 716             break;
 717         case 'e':
 718             shared = strtol(optarg, &end, 0);
 719             if (*end) {
 720                 error_report("Invalid shared device number '%s'", optarg);
 721                 exit(EXIT_FAILURE);
 722             }
 723             if (shared < 1) {
 724                 error_report("Shared device number must be greater than 0");
 725                 exit(EXIT_FAILURE);
 726             }
 727             break;
 728         case 'f':
 729             fmt = optarg;
 730             break;
 731         case 't':
 732             persistent = 1;
 733             break;
 734         case 'x':
 735             export_name = optarg;
 736             break;
 737         case 'D':
 738             export_description = optarg;
 739             break;
 740         case 'v':
 741             verbose = 1;
 742             break;
 743         case 'V':
 744             version(argv[0]);
 745             exit(0);
 746             break;
 747         case 'h':
 748             usage(argv[0]);
 749             exit(0);
 750             break;
 751         case '?':
 752             error_report("Try `%s --help' for more information.", argv[0]);
 753             exit(EXIT_FAILURE);
 754         case QEMU_NBD_OPT_OBJECT: {
 755             QemuOpts *opts;
 756             opts = qemu_opts_parse_noisily(&qemu_object_opts,
 757                                            optarg, true);
 758             if (!opts) {
 759                 exit(EXIT_FAILURE);
 760             }
 761         }   break;
 762         case QEMU_NBD_OPT_TLSCREDS:
 763             tlscredsid = optarg;
 764             break;
 765         case QEMU_NBD_OPT_IMAGE_OPTS:
 766             imageOpts = true;
 767             break;
 768         case 'T':
 769             g_free(trace_file);
 770             trace_file = trace_opt_parse(optarg);
 771             break;
 772         case QEMU_NBD_OPT_FORK:
 773             fork_process = true;
 774             break;
 775         }
 776     }
 777
 778     if ((argc - optind) != 1) {
 779         error_report("Invalid number of arguments");
 780         error_printf("Try `%s --help' for more information.\n", argv[0]);
 781         exit(EXIT_FAILURE);
 782     }
 783
 784     qemu_opts_foreach(&qemu_object_opts,
 785                       user_creatable_add_opts_foreach,
 786                       NULL, &error_fatal);
 787
 788     if (!trace_init_backends()) {
 789         exit(1);
 790     }
 791     trace_init_file(trace_file);
 792     qemu_set_log(LOG_TRACE);
 793
 794     socket_activation = check_socket_activation();
 795     if (socket_activation == 0) {
 796         setup_address_and_port(&bindto, &port);
 797     } else {
 798         /* Using socket activation - check user didn't use -p etc. */
 799         const char *err_msg = socket_activation_validate_opts(device, sockpath,
 800                                                               bindto, port);
 801         if (err_msg != NULL) {
 802             error_report("%s", err_msg);
 803             exit(EXIT_FAILURE);
 804         }
 805
 806         /* qemu-nbd can only listen on a single socket.  */
 807         if (socket_activation > 1) {
 808             error_report("qemu-nbd does not support socket activation with %s > 1",
 809                          "LISTEN_FDS");
 810             exit(EXIT_FAILURE);
 811         }
 812     }
 813
 814     if (tlscredsid) {
 815         if (sockpath) {
 816             error_report("TLS is only supported with IPv4/IPv6");
 817             exit(EXIT_FAILURE);
 818         }
 819         if (device) {
 820             error_report("TLS is not supported with a host device");
 821             exit(EXIT_FAILURE);
 822         }
 823         tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);
 824         if (local_err) {
 825             error_report("Failed to get TLS creds %s",
 826                          error_get_pretty(local_err));
 827             exit(EXIT_FAILURE);
 828         }
 829     }
 830
 831 #if !HAVE_NBD_DEVICE
 832     if (disconnect || device) {
 833         error_report("Kernel /dev/nbdN support not available");
 834         exit(EXIT_FAILURE);
 835     }
 836 #else /* HAVE_NBD_DEVICE */
 837     if (disconnect) {
 838         int nbdfd = open(argv[optind], O_RDWR);
 839         if (nbdfd < 0) {
 840             error_report("Cannot open %s: %s", argv[optind],
 841                          strerror(errno));
 842             exit(EXIT_FAILURE);
 843         }
 844         nbd_disconnect(nbdfd);
 845
 846         close(nbdfd);
 847
 848         printf("%s disconnected\n", argv[optind]);
 849
 850         return 0;
 851     }
 852 #endif
 853
 854     if ((device && !verbose) || fork_process) {
 855         int stderr_fd[2];
 856         pid_t pid;
 857         int ret;
 858
 859         if (qemu_pipe(stderr_fd) < 0) {
 860             error_report("Error setting up communication pipe: %s",
 861                          strerror(errno));
 862             exit(EXIT_FAILURE);
 863         }
 864
 865         /* Now daemonize, but keep a communication channel open to
 866          * print errors and exit with the proper status code.
 867          */
 868         pid = fork();
 869         if (pid < 0) {
 870             error_report("Failed to fork: %s", strerror(errno));
 871             exit(EXIT_FAILURE);
 872         } else if (pid == 0) {
 873             close(stderr_fd[0]);
 874             ret = qemu_daemon(1, 0);
 875
 876             /* Temporarily redirect stderr to the parent's pipe...  */
 877             old_stderr = dup(STDERR_FILENO);
 878             dup2(stderr_fd[1], STDERR_FILENO);
 879             if (ret < 0) {
 880                 error_report("Failed to daemonize: %s", strerror(errno));
 881                 exit(EXIT_FAILURE);
 882             }
 883
 884             /* ... close the descriptor we inherited and go on.  */
 885             close(stderr_fd[1]);
 886         } else {
 887             bool errors = false;
 888             char *buf;
 889
 890             /* In the parent.  Print error messages from the child until
 891              * it closes the pipe.
 892              */
 893             close(stderr_fd[1]);
 894             buf = g_malloc(1024);
 895             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
 896                 errors = true;
 897                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
 898                 if (ret < 0) {
 899                     exit(EXIT_FAILURE);
 900                 }
 901             }
 902             if (ret < 0) {
 903                 error_report("Cannot read from daemon: %s",
 904                              strerror(errno));
 905                 exit(EXIT_FAILURE);
 906             }
 907
 908             /* Usually the daemon should not print any message.
 909              * Exit with zero status in that case.
 910              */
 911             exit(errors);
 912         }
 913     }
 914
 915     if (device != NULL && sockpath == NULL) {
 916         sockpath = g_malloc(128);
 917         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
 918     }
 919
 920     server = qio_net_listener_new();
 921     if (socket_activation == 0) {
 922         saddr = nbd_build_socket_address(sockpath, bindto, port);
 923         if (qio_net_listener_open_sync(server, saddr, &local_err) < 0) {
 924             object_unref(OBJECT(server));
 925             error_report_err(local_err);
 926             exit(EXIT_FAILURE);
 927         }
 928     } else {
 929         size_t i;
 930         /* See comment in check_socket_activation above. */
 931         for (i = 0; i < socket_activation; i++) {
 932             QIOChannelSocket *sioc;
 933             sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
 934                                              &local_err);
 935             if (sioc == NULL) {
 936                 object_unref(OBJECT(server));
 937                 error_report("Failed to use socket activation: %s",
 938                              error_get_pretty(local_err));
 939                 exit(EXIT_FAILURE);
 940             }
 941             qio_net_listener_add(server, sioc);
 942             object_unref(OBJECT(sioc));
 943         }
 944     }
 945
 946     if (qemu_init_main_loop(&local_err)) {
 947         error_report_err(local_err);
 948         exit(EXIT_FAILURE);
 949     }
 950     bdrv_init();
 951     atexit(qemu_nbd_shutdown);
 952
 953     srcpath = argv[optind];
 954     if (imageOpts) {
 955         QemuOpts *opts;
 956         if (fmt) {
 957             error_report("--image-opts and -f are mutually exclusive");
 958             exit(EXIT_FAILURE);
 959         }
 960         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
 961         if (!opts) {
 962             qemu_opts_reset(&file_opts);
 963             exit(EXIT_FAILURE);
 964         }
 965         options = qemu_opts_to_qdict(opts, NULL);
 966         qemu_opts_reset(&file_opts);
 967         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
 968     } else {
 969         if (fmt) {
 970             options = qdict_new();
 971             qdict_put_str(options, "driver", fmt);
 972         }
 973         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
 974     }
 975
 976     if (!blk) {
 977         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
 978                           argv[optind]);
 979         exit(EXIT_FAILURE);
 980     }
 981     bs = blk_bs(blk);
 982
 983     blk_set_enable_write_cache(blk, !writethrough);
 984
 985     if (sn_opts) {
 986         ret = bdrv_snapshot_load_tmp(bs,
 987                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
 988                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
 989                                      &local_err);
 990     } else if (sn_id_or_name) {
 991         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
 992                                                    &local_err);
 993     }
 994     if (ret < 0) {
 995         error_reportf_err(local_err, "Failed to load snapshot: ");
 996         exit(EXIT_FAILURE);
 997     }
 998
 999     bs->detect_zeroes = detect_zeroes;
1000     fd_size = blk_getlength(blk);
1001     if (fd_size < 0) {
1002         error_report("Failed to determine the image length: %s",
1003                      strerror(-fd_size));
1004         exit(EXIT_FAILURE);
1005     }
1006
1007     if (dev_offset >= fd_size) {
1008         error_report("Offset (%lld) has to be smaller than the image size "
1009                      "(%lld)",
1010                      (long long int)dev_offset, (long long int)fd_size);
1011         exit(EXIT_FAILURE);
1012     }
1013     fd_size -= dev_offset;
1014
1015     if (partition != -1) {
1016         ret = find_partition(blk, partition, &dev_offset, &fd_size);
1017         if (ret < 0) {
1018             error_report("Could not find partition %d: %s", partition,
1019                          strerror(-ret));
1020             exit(EXIT_FAILURE);
1021         }
1022     }
1023
1024     export = nbd_export_new(bs, dev_offset, fd_size, export_name,
1025                             export_description, bitmap, nbdflags,
1026                             nbd_export_closed, writethrough, NULL,
1027                             &error_fatal);
1028
1029     if (device) {
1030 #if HAVE_NBD_DEVICE
1031         int ret;
1032
1033         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
1034         if (ret != 0) {
1035             error_report("Failed to create client thread: %s", strerror(ret));
1036             exit(EXIT_FAILURE);
1037         }
1038 #endif
1039     } else {
1040         /* Shut up GCC warnings.  */
1041         memset(&client_thread, 0, sizeof(client_thread));
1042     }
1043
1044     nbd_update_server_watch();
1045
1046     /* now when the initialization is (almost) complete, chdir("/")
1047      * to free any busy filesystems */
1048     if (chdir("/") < 0) {
1049         error_report("Could not chdir to root directory: %s",
1050                      strerror(errno));
1051         exit(EXIT_FAILURE);
1052     }
1053
1054     if (fork_process) {
1055         dup2(old_stderr, STDERR_FILENO);
1056         close(old_stderr);
1057     }
1058
1059     state = RUNNING;
1060     do {
1061         main_loop_wait(false);
1062         if (state == TERMINATE) {
1063             state = TERMINATING;
1064             nbd_export_close(export);
1065             nbd_export_put(export);
1066             export = NULL;
1067         }
1068     } while (state != TERMINATED);
1069
1070     blk_unref(blk);
1071     if (sockpath) {
1072         unlink(sockpath);
1073     }
1074
1075     qemu_opts_del(sn_opts);
1076
1077     if (device) {
1078         void *ret;
1079         pthread_join(client_thread, &ret);
1080         exit(ret != NULL);
1081     } else {
1082         exit(EXIT_SUCCESS);
1083     }
1084 }