qemu-nbd.c

   1 /*
   2  *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
   3  *
   4  *  Network Block Device
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; under version 2 of the License.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "qemu/osdep.h"
  20 #include <getopt.h>
  21 #include <libgen.h>
  22 #include <pthread.h>
  23
  24 #include "qemu/help-texts.h"
  25 #include "qapi/error.h"
  26 #include "qemu/cutils.h"
  27 #include "sysemu/block-backend.h"
  28 #include "sysemu/runstate.h" /* for qemu_system_killed() prototype */
  29 #include "block/block_int.h"
  30 #include "block/nbd.h"
  31 #include "qemu/main-loop.h"
  32 #include "qemu/module.h"
  33 #include "qemu/option.h"
  34 #include "qemu/error-report.h"
  35 #include "qemu/config-file.h"
  36 #include "qemu/bswap.h"
  37 #include "qemu/log.h"
  38 #include "qemu/systemd.h"
  39 #include "block/snapshot.h"
  40 #include "qapi/qmp/qdict.h"
  41 #include "qapi/qmp/qstring.h"
  42 #include "qom/object_interfaces.h"
  43 #include "io/channel-socket.h"
  44 #include "io/net-listener.h"
  45 #include "crypto/init.h"
  46 #include "crypto/tlscreds.h"
  47 #include "trace/control.h"
  48 #include "qemu-version.h"
  49
  50 #ifdef CONFIG_SELINUX
  51 #include <selinux/selinux.h>
  52 #endif
  53
  54 #ifdef __linux__
  55 #define HAVE_NBD_DEVICE 1
  56 #else
  57 #define HAVE_NBD_DEVICE 0
  58 #endif
  59
  60 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
  61 #define QEMU_NBD_OPT_CACHE         256
  62 #define QEMU_NBD_OPT_AIO           257
  63 #define QEMU_NBD_OPT_DISCARD       258
  64 #define QEMU_NBD_OPT_DETECT_ZEROES 259
  65 #define QEMU_NBD_OPT_OBJECT        260
  66 #define QEMU_NBD_OPT_TLSCREDS      261
  67 #define QEMU_NBD_OPT_IMAGE_OPTS    262
  68 #define QEMU_NBD_OPT_FORK          263
  69 #define QEMU_NBD_OPT_TLSAUTHZ      264
  70 #define QEMU_NBD_OPT_PID_FILE      265
  71 #define QEMU_NBD_OPT_SELINUX_LABEL 266
  72 #define QEMU_NBD_OPT_TLSHOSTNAME   267
  73
  74 #define MBR_SIZE 512
  75
  76 static int persistent = 0;
  77 static enum { RUNNING, TERMINATE, TERMINATED } state;
  78 static int shared = 1;
  79 static int nb_fds;
  80 static QIONetListener *server;
  81 static QCryptoTLSCreds *tlscreds;
  82 static const char *tlsauthz;
  83
  84 static void usage(const char *name)
  85 {
  86     (printf) (
  87 "Usage: %s [OPTIONS] FILE\n"
  88 "  or:  %s -L [OPTIONS]\n"
  89 "QEMU Disk Network Block Device Utility\n"
  90 "\n"
  91 "  -h, --help                display this help and exit\n"
  92 "  -V, --version             output version information and exit\n"
  93 "\n"
  94 "Connection properties:\n"
  95 "  -p, --port=PORT           port to listen on (default `%d')\n"
  96 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
  97 "  -k, --socket=PATH         path to the unix socket\n"
  98 "                            (default '"SOCKET_PATH"')\n"
  99 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
 100 "  -t, --persistent          don't exit on the last connection\n"
 101 "  -v, --verbose             display extra debugging information\n"
 102 "  -x, --export-name=NAME    expose export by name (default is empty string)\n"
 103 "  -D, --description=TEXT    export a human-readable description\n"
 104 "\n"
 105 "Exposing part of the image:\n"
 106 "  -o, --offset=OFFSET       offset into the image\n"
 107 "  -A, --allocation-depth    expose the allocation depth\n"
 108 "  -B, --bitmap=NAME         expose a persistent dirty bitmap\n"
 109 "\n"
 110 "General purpose options:\n"
 111 "  -L, --list                list exports available from another NBD server\n"
 112 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
 113 "                            passwords and/or encryption keys\n"
 114 "  --tls-creds=ID            use id of an earlier --object to provide TLS\n"
 115 "  --tls-authz=ID            use id of an earlier --object to provide\n"
 116 "                            authorization\n"
 117 "  --tls-hostname=HOSTNAME   override hostname used to check x509 certificate\n"
 118 "  -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
 119 "                            specify tracing options\n"
 120 "  --fork                    fork off the server process and exit the parent\n"
 121 "                            once the server is running\n"
 122 "  --pid-file=PATH           store the server's process ID in the given file\n"
 123 #ifdef CONFIG_SELINUX
 124 "  --selinux-label=LABEL     set SELinux process label on listening socket\n"
 125 #endif
 126 #if HAVE_NBD_DEVICE
 127 "\n"
 128 "Kernel NBD client support:\n"
 129 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
 130 "  -d, --disconnect          disconnect the specified device\n"
 131 #endif
 132 "\n"
 133 "Block device options:\n"
 134 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
 135 "  -r, --read-only           export read-only\n"
 136 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
 137 "                            file with backing_file=FILE, redirect the write to\n"
 138 "                            the temporary one\n"
 139 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
 140 "                            load an internal snapshot inside FILE and export it\n"
 141 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
 142 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
 143 "                            '[ID_OR_NAME]'\n"
 144 "  -n, --nocache             disable host cache\n"
 145 "      --cache=MODE          set cache mode used to access the disk image, the\n"
 146 "                            valid options are: 'none', 'writeback' (default),\n"
 147 "                            'writethrough', 'directsync' and 'unsafe'\n"
 148 "      --aio=MODE            set AIO mode (native, io_uring or threads)\n"
 149 "      --discard=MODE        set discard mode (ignore, unmap)\n"
 150 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
 151 "      --image-opts          treat FILE as a full set of image options\n"
 152 "\n"
 153 QEMU_HELP_BOTTOM "\n"
 154     , name, name, NBD_DEFAULT_PORT, "DEVICE");
 155 }
 156
 157 static void version(const char *name)
 158 {
 159     printf(
 160 "%s " QEMU_FULL_VERSION "\n"
 161 "Written by Anthony Liguori.\n"
 162 "\n"
 163 QEMU_COPYRIGHT "\n"
 164 "This is free software; see the source for copying conditions.  There is NO\n"
 165 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
 166     , name);
 167 }
 168
 169 #ifdef CONFIG_POSIX
 170 /*
 171  * The client thread uses SIGTERM to interrupt the server.  A signal
 172  * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
 173  */
 174 void qemu_system_killed(int signum, pid_t pid)
 175 {
 176     qatomic_cmpxchg(&state, RUNNING, TERMINATE);
 177     qemu_notify_event();
 178 }
 179 #endif /* CONFIG_POSIX */
 180
 181 static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
 182                                 const char *hostname)
 183 {
 184     int ret = EXIT_FAILURE;
 185     int rc;
 186     Error *err = NULL;
 187     QIOChannelSocket *sioc;
 188     NBDExportInfo *list;
 189     int i, j;
 190
 191     sioc = qio_channel_socket_new();
 192     if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
 193         error_report_err(err);
 194         goto out;
 195     }
 196     rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
 197                                  &err);
 198     if (rc < 0) {
 199         if (err) {
 200             error_report_err(err);
 201         }
 202         goto out;
 203     }
 204     printf("exports available: %d\n", rc);
 205     for (i = 0; i < rc; i++) {
 206         printf(" export: '%s'\n", list[i].name);
 207         if (list[i].description && *list[i].description) {
 208             printf("  description: %s\n", list[i].description);
 209         }
 210         if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
 211             static const char *const flag_names[] = {
 212                 [NBD_FLAG_READ_ONLY_BIT]            = "readonly",
 213                 [NBD_FLAG_SEND_FLUSH_BIT]           = "flush",
 214                 [NBD_FLAG_SEND_FUA_BIT]             = "fua",
 215                 [NBD_FLAG_ROTATIONAL_BIT]           = "rotational",
 216                 [NBD_FLAG_SEND_TRIM_BIT]            = "trim",
 217                 [NBD_FLAG_SEND_WRITE_ZEROES_BIT]    = "zeroes",
 218                 [NBD_FLAG_SEND_DF_BIT]              = "df",
 219                 [NBD_FLAG_CAN_MULTI_CONN_BIT]       = "multi",
 220                 [NBD_FLAG_SEND_RESIZE_BIT]          = "resize",
 221                 [NBD_FLAG_SEND_CACHE_BIT]           = "cache",
 222                 [NBD_FLAG_SEND_FAST_ZERO_BIT]       = "fast-zero",
 223                 [NBD_FLAG_BLOCK_STAT_PAYLOAD_BIT]   = "block-status-payload",
 224             };
 225
 226             printf("  size:  %" PRIu64 "\n", list[i].size);
 227             printf("  flags: 0x%x (", list[i].flags);
 228             for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) {
 229                 if (flag_names[bit] && (list[i].flags & (1 << bit))) {
 230                     printf(" %s", flag_names[bit]);
 231                 }
 232             }
 233             printf(" )\n");
 234         }
 235         if (list[i].min_block) {
 236             printf("  min block: %u\n", list[i].min_block);
 237             printf("  opt block: %u\n", list[i].opt_block);
 238             printf("  max block: %u\n", list[i].max_block);
 239         }
 240         printf("  transaction size: %s\n",
 241                list[i].mode >= NBD_MODE_EXTENDED ?
 242                "64-bit" : "32-bit");
 243         if (list[i].n_contexts) {
 244             printf("  available meta contexts: %d\n", list[i].n_contexts);
 245             for (j = 0; j < list[i].n_contexts; j++) {
 246                 printf("   %s\n", list[i].contexts[j]);
 247             }
 248         }
 249     }
 250     nbd_free_export_list(list, rc);
 251
 252     ret = EXIT_SUCCESS;
 253  out:
 254     object_unref(OBJECT(sioc));
 255     return ret;
 256 }
 257
 258
 259 struct NbdClientOpts {
 260     char *device;
 261     char *srcpath;
 262     SocketAddress *saddr;
 263     int old_stderr;
 264     bool fork_process;
 265     bool verbose;
 266 };
 267
 268 static void nbd_client_release_pipe(int old_stderr)
 269 {
 270     /* Close stderr so that the qemu-nbd process exits.  */
 271     if (dup2(old_stderr, STDERR_FILENO) < 0) {
 272         error_report("Could not release pipe to parent: %s",
 273                      strerror(errno));
 274         exit(EXIT_FAILURE);
 275     }
 276     if (old_stderr != STDOUT_FILENO && close(old_stderr) < 0) {
 277         error_report("Could not release qemu-nbd: %s", strerror(errno));
 278         exit(EXIT_FAILURE);
 279     }
 280 }
 281
 282 #if HAVE_NBD_DEVICE
 283 static void *show_parts(void *arg)
 284 {
 285     char *device = arg;
 286     int nbd;
 287
 288     /* linux just needs an open() to trigger
 289      * the partition table update
 290      * but remember to load the module with max_part != 0 :
 291      *     modprobe nbd max_part=63
 292      */
 293     nbd = open(device, O_RDWR);
 294     if (nbd >= 0) {
 295         close(nbd);
 296     }
 297     return NULL;
 298 }
 299
 300 static void *nbd_client_thread(void *arg)
 301 {
 302     struct NbdClientOpts *opts = arg;
 303     /* TODO: Revisit this if nbd.ko ever gains support for structured reply */
 304     NBDExportInfo info = { .request_sizes = false, .name = g_strdup(""),
 305                            .mode = NBD_MODE_SIMPLE };
 306     QIOChannelSocket *sioc;
 307     int fd = -1;
 308     int ret = EXIT_FAILURE;
 309     pthread_t show_parts_thread;
 310     Error *local_error = NULL;
 311
 312     sioc = qio_channel_socket_new();
 313     if (qio_channel_socket_connect_sync(sioc,
 314                                         opts->saddr,
 315                                         &local_error) < 0) {
 316         error_report_err(local_error);
 317         goto out;
 318     }
 319
 320     if (nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, NULL, NULL,
 321                               &info, &local_error) < 0) {
 322         if (local_error) {
 323             error_report_err(local_error);
 324         }
 325         goto out;
 326     }
 327
 328     fd = open(opts->device, O_RDWR);
 329     if (fd < 0) {
 330         /* Linux-only, we can use %m in printf.  */
 331         error_report("Failed to open %s: %m", opts->device);
 332         goto out;
 333     }
 334
 335     if (nbd_init(fd, sioc, &info, &local_error) < 0) {
 336         error_report_err(local_error);
 337         goto out;
 338     }
 339
 340     /* update partition table */
 341     pthread_create(&show_parts_thread, NULL, show_parts, opts->device);
 342
 343     if (opts->verbose && !opts->fork_process) {
 344         fprintf(stderr, "NBD device %s is now connected to %s\n",
 345                 opts->device, opts->srcpath);
 346     } else {
 347         nbd_client_release_pipe(opts->old_stderr);
 348     }
 349
 350     if (nbd_client(fd) < 0) {
 351         goto out;
 352     }
 353
 354     ret = EXIT_SUCCESS;
 355
 356  out:
 357     if (fd >= 0) {
 358         close(fd);
 359     }
 360     object_unref(OBJECT(sioc));
 361     g_free(info.name);
 362     kill(getpid(), SIGTERM);
 363     return (void *) (intptr_t) ret;
 364 }
 365 #endif /* HAVE_NBD_DEVICE */
 366
 367 static int nbd_can_accept(void)
 368 {
 369     return state == RUNNING && (shared == 0 || nb_fds < shared);
 370 }
 371
 372 static void nbd_update_server_watch(void);
 373
 374 static void nbd_client_closed(NBDClient *client, bool negotiated)
 375 {
 376     nb_fds--;
 377     if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
 378         state = TERMINATE;
 379     }
 380     nbd_update_server_watch();
 381     nbd_client_put(client);
 382 }
 383
 384 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
 385                        gpointer opaque)
 386 {
 387     if (state >= TERMINATE) {
 388         return;
 389     }
 390
 391     nb_fds++;
 392     nbd_update_server_watch();
 393     nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
 394 }
 395
 396 static void nbd_update_server_watch(void)
 397 {
 398     if (nbd_can_accept()) {
 399         qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
 400     } else {
 401         qio_net_listener_set_client_func(server, NULL, NULL, NULL);
 402     }
 403 }
 404
 405
 406 static SocketAddress *nbd_build_socket_address(const char *sockpath,
 407                                                const char *bindto,
 408                                                const char *port)
 409 {
 410     SocketAddress *saddr;
 411
 412     saddr = g_new0(SocketAddress, 1);
 413     if (sockpath) {
 414         saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
 415         saddr->u.q_unix.path = g_strdup(sockpath);
 416     } else {
 417         InetSocketAddress *inet;
 418         saddr->type = SOCKET_ADDRESS_TYPE_INET;
 419         inet = &saddr->u.inet;
 420         inet->host = g_strdup(bindto);
 421         if (port) {
 422             inet->port = g_strdup(port);
 423         } else  {
 424             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 425         }
 426     }
 427
 428     return saddr;
 429 }
 430
 431
 432 static QemuOptsList file_opts = {
 433     .name = "file",
 434     .implied_opt_name = "file",
 435     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
 436     .desc = {
 437         /* no elements => accept any params */
 438         { /* end of list */ }
 439     },
 440 };
 441
 442 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
 443                                           Error **errp)
 444 {
 445     Object *obj;
 446     QCryptoTLSCreds *creds;
 447
 448     obj = object_resolve_path_component(
 449         object_get_objects_root(), id);
 450     if (!obj) {
 451         error_setg(errp, "No TLS credentials with id '%s'",
 452                    id);
 453         return NULL;
 454     }
 455     creds = (QCryptoTLSCreds *)
 456         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 457     if (!creds) {
 458         error_setg(errp, "Object with id '%s' is not TLS credentials",
 459                    id);
 460         return NULL;
 461     }
 462
 463     if (!qcrypto_tls_creds_check_endpoint(creds,
 464                                           list
 465                                           ? QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT
 466                                           : QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
 467                                           errp)) {
 468         return NULL;
 469     }
 470     object_ref(obj);
 471     return creds;
 472 }
 473
 474 static void setup_address_and_port(const char **address, const char **port)
 475 {
 476     if (*address == NULL) {
 477         *address = "0.0.0.0";
 478     }
 479
 480     if (*port == NULL) {
 481         *port = stringify(NBD_DEFAULT_PORT);
 482     }
 483 }
 484
 485 /*
 486  * Check socket parameters compatibility when socket activation is used.
 487  */
 488 static const char *socket_activation_validate_opts(const char *device,
 489                                                    const char *sockpath,
 490                                                    const char *address,
 491                                                    const char *port,
 492                                                    const char *selinux,
 493                                                    bool list)
 494 {
 495     if (device != NULL) {
 496         return "NBD device can't be set when using socket activation";
 497     }
 498
 499     if (sockpath != NULL) {
 500         return "Unix socket can't be set when using socket activation";
 501     }
 502
 503     if (address != NULL) {
 504         return "The interface can't be set when using socket activation";
 505     }
 506
 507     if (port != NULL) {
 508         return "TCP port number can't be set when using socket activation";
 509     }
 510
 511     if (selinux != NULL) {
 512         return "SELinux label can't be set when using socket activation";
 513     }
 514
 515     if (list) {
 516         return "List mode is incompatible with socket activation";
 517     }
 518
 519     return NULL;
 520 }
 521
 522 static void qemu_nbd_shutdown(void)
 523 {
 524     job_cancel_sync_all();
 525     blk_exp_close_all();
 526     bdrv_close_all();
 527 }
 528
 529 int main(int argc, char **argv)
 530 {
 531     BlockBackend *blk;
 532     BlockDriverState *bs;
 533     uint64_t dev_offset = 0;
 534     bool readonly = false;
 535     bool disconnect = false;
 536     const char *bindto = NULL;
 537     const char *port = NULL;
 538     char *sockpath = NULL;
 539     QemuOpts *sn_opts = NULL;
 540     const char *sn_id_or_name = NULL;
 541     const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:AB:L";
 542     struct option lopt[] = {
 543         { "help", no_argument, NULL, 'h' },
 544         { "version", no_argument, NULL, 'V' },
 545         { "bind", required_argument, NULL, 'b' },
 546         { "port", required_argument, NULL, 'p' },
 547         { "socket", required_argument, NULL, 'k' },
 548         { "offset", required_argument, NULL, 'o' },
 549         { "read-only", no_argument, NULL, 'r' },
 550         { "allocation-depth", no_argument, NULL, 'A' },
 551         { "bitmap", required_argument, NULL, 'B' },
 552         { "connect", required_argument, NULL, 'c' },
 553         { "disconnect", no_argument, NULL, 'd' },
 554         { "list", no_argument, NULL, 'L' },
 555         { "snapshot", no_argument, NULL, 's' },
 556         { "load-snapshot", required_argument, NULL, 'l' },
 557         { "nocache", no_argument, NULL, 'n' },
 558         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
 559         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
 560         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
 561         { "detect-zeroes", required_argument, NULL,
 562           QEMU_NBD_OPT_DETECT_ZEROES },
 563         { "shared", required_argument, NULL, 'e' },
 564         { "format", required_argument, NULL, 'f' },
 565         { "persistent", no_argument, NULL, 't' },
 566         { "verbose", no_argument, NULL, 'v' },
 567         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
 568         { "export-name", required_argument, NULL, 'x' },
 569         { "description", required_argument, NULL, 'D' },
 570         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
 571         { "tls-hostname", required_argument, NULL, QEMU_NBD_OPT_TLSHOSTNAME },
 572         { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
 573         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
 574         { "trace", required_argument, NULL, 'T' },
 575         { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
 576         { "pid-file", required_argument, NULL, QEMU_NBD_OPT_PID_FILE },
 577         { "selinux-label", required_argument, NULL,
 578           QEMU_NBD_OPT_SELINUX_LABEL },
 579         { NULL, 0, NULL, 0 }
 580     };
 581     int ch;
 582     int opt_ind = 0;
 583     int flags = BDRV_O_RDWR;
 584     int ret = 0;
 585     bool seen_cache = false;
 586     bool seen_discard = false;
 587     bool seen_aio = false;
 588     pthread_t client_thread;
 589     const char *fmt = NULL;
 590     Error *local_err = NULL;
 591     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
 592     QDict *options = NULL;
 593     const char *export_name = NULL; /* defaults to "" later for server mode */
 594     const char *export_description = NULL;
 595     BlockDirtyBitmapOrStrList *bitmaps = NULL;
 596     bool alloc_depth = false;
 597     const char *tlscredsid = NULL;
 598     const char *tlshostname = NULL;
 599     bool imageOpts = false;
 600     bool writethrough = false; /* Client will flush as needed. */
 601     bool list = false;
 602     unsigned socket_activation;
 603     const char *pid_file_name = NULL;
 604     const char *selinux_label = NULL;
 605     BlockExportOptions *export_opts;
 606     struct NbdClientOpts opts = {
 607         .fork_process = false,
 608         .verbose = false,
 609         .device = NULL,
 610         .srcpath = NULL,
 611         .saddr = NULL,
 612         .old_stderr = STDOUT_FILENO,
 613     };
 614
 615 #ifdef CONFIG_POSIX
 616     os_setup_early_signal_handling();
 617     os_setup_signal_handling();
 618 #endif
 619
 620     socket_init();
 621     error_init(argv[0]);
 622     module_call_init(MODULE_INIT_TRACE);
 623     qcrypto_init(&error_fatal);
 624
 625     module_call_init(MODULE_INIT_QOM);
 626     qemu_add_opts(&qemu_trace_opts);
 627     qemu_init_exec_dir(argv[0]);
 628
 629     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 630         switch (ch) {
 631         case 's':
 632             flags |= BDRV_O_SNAPSHOT;
 633             break;
 634         case 'n':
 635             optarg = (char *) "none";
 636             /* fallthrough */
 637         case QEMU_NBD_OPT_CACHE:
 638             if (seen_cache) {
 639                 error_report("-n and --cache can only be specified once");
 640                 exit(EXIT_FAILURE);
 641             }
 642             seen_cache = true;
 643             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
 644                 error_report("Invalid cache mode `%s'", optarg);
 645                 exit(EXIT_FAILURE);
 646             }
 647             break;
 648         case QEMU_NBD_OPT_AIO:
 649             if (seen_aio) {
 650                 error_report("--aio can only be specified once");
 651                 exit(EXIT_FAILURE);
 652             }
 653             seen_aio = true;
 654             if (bdrv_parse_aio(optarg, &flags) < 0) {
 655                 error_report("Invalid aio mode '%s'", optarg);
 656                 exit(EXIT_FAILURE);
 657             }
 658             break;
 659         case QEMU_NBD_OPT_DISCARD:
 660             if (seen_discard) {
 661                 error_report("--discard can only be specified once");
 662                 exit(EXIT_FAILURE);
 663             }
 664             seen_discard = true;
 665             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 666                 error_report("Invalid discard mode `%s'", optarg);
 667                 exit(EXIT_FAILURE);
 668             }
 669             break;
 670         case QEMU_NBD_OPT_DETECT_ZEROES:
 671             detect_zeroes =
 672                 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
 673                                 optarg,
 674                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
 675                                 &local_err);
 676             if (local_err) {
 677                 error_reportf_err(local_err,
 678                                   "Failed to parse detect_zeroes mode: ");
 679                 exit(EXIT_FAILURE);
 680             }
 681             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
 682                 !(flags & BDRV_O_UNMAP)) {
 683                 error_report("setting detect-zeroes to unmap is not allowed "
 684                              "without setting discard operation to unmap");
 685                 exit(EXIT_FAILURE);
 686             }
 687             break;
 688         case 'b':
 689             bindto = optarg;
 690             break;
 691         case 'p':
 692             port = optarg;
 693             break;
 694         case 'o':
 695             if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
 696                 error_report("Invalid offset '%s'", optarg);
 697                 exit(EXIT_FAILURE);
 698             }
 699             break;
 700         case 'l':
 701             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 702                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
 703                                                   optarg, false);
 704                 if (!sn_opts) {
 705                     error_report("Failed in parsing snapshot param `%s'",
 706                                  optarg);
 707                     exit(EXIT_FAILURE);
 708                 }
 709             } else {
 710                 sn_id_or_name = optarg;
 711             }
 712             /* fall through */
 713         case 'r':
 714             readonly = true;
 715             flags &= ~BDRV_O_RDWR;
 716             break;
 717         case 'A':
 718             alloc_depth = true;
 719             break;
 720         case 'B':
 721             {
 722                 BlockDirtyBitmapOrStr *el = g_new(BlockDirtyBitmapOrStr, 1);
 723                 *el = (BlockDirtyBitmapOrStr) {
 724                     .type = QTYPE_QSTRING,
 725                     .u.local = g_strdup(optarg),
 726                 };
 727                 QAPI_LIST_PREPEND(bitmaps, el);
 728             }
 729             break;
 730         case 'k':
 731             sockpath = optarg;
 732             if (sockpath[0] != '/') {
 733                 error_report("socket path must be absolute");
 734                 exit(EXIT_FAILURE);
 735             }
 736             break;
 737         case 'd':
 738             disconnect = true;
 739             break;
 740         case 'c':
 741             opts.device = optarg;
 742             break;
 743         case 'e':
 744             if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
 745                 shared < 0) {
 746                 error_report("Invalid shared device number '%s'", optarg);
 747                 exit(EXIT_FAILURE);
 748             }
 749             break;
 750         case 'f':
 751             fmt = optarg;
 752             break;
 753         case 't':
 754             persistent = 1;
 755             break;
 756         case 'x':
 757             export_name = optarg;
 758             if (strlen(export_name) > NBD_MAX_STRING_SIZE) {
 759                 error_report("export name '%s' too long", export_name);
 760                 exit(EXIT_FAILURE);
 761             }
 762             break;
 763         case 'D':
 764             export_description = optarg;
 765             if (strlen(export_description) > NBD_MAX_STRING_SIZE) {
 766                 error_report("export description '%s' too long",
 767                              export_description);
 768                 exit(EXIT_FAILURE);
 769             }
 770             break;
 771         case 'v':
 772             opts.verbose = true;
 773             break;
 774         case 'V':
 775             version(argv[0]);
 776             exit(0);
 777             break;
 778         case 'h':
 779             usage(argv[0]);
 780             exit(0);
 781             break;
 782         case '?':
 783             error_report("Try `%s --help' for more information.", argv[0]);
 784             exit(EXIT_FAILURE);
 785         case QEMU_NBD_OPT_OBJECT:
 786             user_creatable_process_cmdline(optarg);
 787             break;
 788         case QEMU_NBD_OPT_TLSCREDS:
 789             tlscredsid = optarg;
 790             break;
 791         case QEMU_NBD_OPT_TLSHOSTNAME:
 792             tlshostname = optarg;
 793             break;
 794         case QEMU_NBD_OPT_IMAGE_OPTS:
 795             imageOpts = true;
 796             break;
 797         case 'T':
 798             trace_opt_parse(optarg);
 799             break;
 800         case QEMU_NBD_OPT_TLSAUTHZ:
 801             tlsauthz = optarg;
 802             break;
 803         case QEMU_NBD_OPT_FORK:
 804             opts.fork_process = true;
 805             break;
 806         case 'L':
 807             list = true;
 808             break;
 809         case QEMU_NBD_OPT_PID_FILE:
 810             pid_file_name = optarg;
 811             break;
 812         case QEMU_NBD_OPT_SELINUX_LABEL:
 813             selinux_label = optarg;
 814             break;
 815         }
 816     }
 817
 818     if (list) {
 819         if (argc != optind) {
 820             error_report("List mode is incompatible with a file name");
 821             exit(EXIT_FAILURE);
 822         }
 823         if (export_name || export_description || dev_offset ||
 824             opts.device || disconnect || fmt || sn_id_or_name || bitmaps ||
 825             alloc_depth || seen_aio || seen_discard || seen_cache) {
 826             error_report("List mode is incompatible with per-device settings");
 827             exit(EXIT_FAILURE);
 828         }
 829         if (opts.fork_process) {
 830             error_report("List mode is incompatible with forking");
 831             exit(EXIT_FAILURE);
 832         }
 833     } else if ((argc - optind) != 1) {
 834         error_report("Invalid number of arguments");
 835         error_printf("Try `%s --help' for more information.\n", argv[0]);
 836         exit(EXIT_FAILURE);
 837     } else if (!export_name) {
 838         export_name = "";
 839     }
 840
 841     if (!trace_init_backends()) {
 842         exit(1);
 843     }
 844     trace_init_file();
 845     qemu_set_log(LOG_TRACE, &error_fatal);
 846
 847     socket_activation = check_socket_activation();
 848     if (socket_activation == 0) {
 849         if (!sockpath) {
 850             setup_address_and_port(&bindto, &port);
 851         }
 852     } else {
 853         /* Using socket activation - check user didn't use -p etc. */
 854         const char *err_msg = socket_activation_validate_opts(opts.device,
 855                                                               sockpath,
 856                                                               bindto, port,
 857                                                               selinux_label,
 858                                                               list);
 859         if (err_msg != NULL) {
 860             error_report("%s", err_msg);
 861             exit(EXIT_FAILURE);
 862         }
 863
 864         /* qemu-nbd can only listen on a single socket.  */
 865         if (socket_activation > 1) {
 866             error_report("qemu-nbd does not support socket activation with %s > 1",
 867                          "LISTEN_FDS");
 868             exit(EXIT_FAILURE);
 869         }
 870     }
 871
 872     if (tlscredsid) {
 873         if (opts.device) {
 874             error_report("TLS is not supported with a host device");
 875             exit(EXIT_FAILURE);
 876         }
 877         if (tlsauthz && list) {
 878             error_report("TLS authorization is incompatible with export list");
 879             exit(EXIT_FAILURE);
 880         }
 881         if (tlshostname && !list) {
 882             error_report("TLS hostname is only supported with export list");
 883             exit(EXIT_FAILURE);
 884         }
 885         tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
 886         if (local_err) {
 887             error_reportf_err(local_err, "Failed to get TLS creds: ");
 888             exit(EXIT_FAILURE);
 889         }
 890     } else {
 891         if (tlsauthz) {
 892             error_report("--tls-authz is not permitted without --tls-creds");
 893             exit(EXIT_FAILURE);
 894         }
 895         if (tlshostname) {
 896             error_report("--tls-hostname is not permitted without --tls-creds");
 897             exit(EXIT_FAILURE);
 898         }
 899     }
 900
 901     if (selinux_label) {
 902 #ifdef CONFIG_SELINUX
 903         if (sockpath == NULL && opts.device == NULL) {
 904             error_report("--selinux-label is not permitted without --socket");
 905             exit(EXIT_FAILURE);
 906         }
 907 #else
 908         error_report("SELinux support not enabled in this binary");
 909         exit(EXIT_FAILURE);
 910 #endif
 911     }
 912
 913     if (list) {
 914         opts.saddr = nbd_build_socket_address(sockpath, bindto, port);
 915         return qemu_nbd_client_list(opts.saddr, tlscreds,
 916                                     tlshostname ? tlshostname : bindto);
 917     }
 918
 919 #if !HAVE_NBD_DEVICE
 920     if (disconnect || opts.device) {
 921         error_report("Kernel /dev/nbdN support not available");
 922         exit(EXIT_FAILURE);
 923     }
 924 #else /* HAVE_NBD_DEVICE */
 925     if (disconnect) {
 926         int nbdfd = open(argv[optind], O_RDWR);
 927         if (nbdfd < 0) {
 928             error_report("Cannot open %s: %s", argv[optind],
 929                          strerror(errno));
 930             exit(EXIT_FAILURE);
 931         }
 932         nbd_disconnect(nbdfd);
 933
 934         close(nbdfd);
 935
 936         printf("%s disconnected\n", argv[optind]);
 937
 938         return 0;
 939     }
 940 #endif
 941
 942     if ((opts.device && !opts.verbose) || opts.fork_process) {
 943 #ifndef WIN32
 944         g_autoptr(GError) err = NULL;
 945         int stderr_fd[2];
 946         pid_t pid;
 947
 948         if (!g_unix_open_pipe(stderr_fd, FD_CLOEXEC, &err)) {
 949             error_report("Error setting up communication pipe: %s",
 950                          err->message);
 951             exit(EXIT_FAILURE);
 952         }
 953
 954         /* Now daemonize, but keep a communication channel open to
 955          * print errors and exit with the proper status code.
 956          */
 957         pid = fork();
 958         if (pid < 0) {
 959             error_report("Failed to fork: %s", strerror(errno));
 960             exit(EXIT_FAILURE);
 961         } else if (pid == 0) {
 962             int saved_errno;
 963
 964             close(stderr_fd[0]);
 965
 966             /* Remember parent's stderr if we will be restoring it. */
 967             if (opts.verbose /* fork_process is set */) {
 968                 opts.old_stderr = dup(STDERR_FILENO);
 969                 if (opts.old_stderr < 0) {
 970                     error_report("Could not dup original stderr: %s",
 971                                  strerror(errno));
 972                     exit(EXIT_FAILURE);
 973                 }
 974             }
 975
 976             ret = qemu_daemon(1, 0);
 977             saved_errno = errno;    /* dup2 will overwrite error below */
 978
 979             /* Temporarily redirect stderr to the parent's pipe...  */
 980             if (dup2(stderr_fd[1], STDERR_FILENO) < 0) {
 981                 char str[256];
 982                 snprintf(str, sizeof(str),
 983                          "%s: Failed to link stderr to the pipe: %s\n",
 984                          g_get_prgname(), strerror(errno));
 985                 /*
 986                  * We are unable to use error_report() here as we need to get
 987                  * stderr pointed to the parent's pipe. Write to that pipe
 988                  * manually.
 989                  */
 990                 ret = write(stderr_fd[1], str, strlen(str));
 991                 exit(EXIT_FAILURE);
 992             }
 993
 994             if (ret < 0) {
 995                 error_report("Failed to daemonize: %s", strerror(saved_errno));
 996                 exit(EXIT_FAILURE);
 997             }
 998
 999             /* ... close the descriptor we inherited and go on.  */
1000             close(stderr_fd[1]);
1001         } else {
1002             bool errors = false;
1003             char *buf;
1004
1005             /* In the parent.  Print error messages from the child until
1006              * it closes the pipe.
1007              */
1008             close(stderr_fd[1]);
1009             buf = g_malloc(1024);
1010             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
1011                 errors = true;
1012                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
1013                 if (ret < 0) {
1014                     exit(EXIT_FAILURE);
1015                 }
1016             }
1017             if (ret < 0) {
1018                 error_report("Cannot read from daemon: %s",
1019                              strerror(errno));
1020                 exit(EXIT_FAILURE);
1021             }
1022
1023             /* Usually the daemon should not print any message.
1024              * Exit with zero status in that case.
1025              */
1026             exit(errors);
1027         }
1028 #else /* WIN32 */
1029         error_report("Unable to fork into background on Windows hosts");
1030         exit(EXIT_FAILURE);
1031 #endif /* WIN32 */
1032     }
1033
1034     if (opts.device != NULL && sockpath == NULL) {
1035         sockpath = g_malloc(128);
1036         snprintf(sockpath, 128, SOCKET_PATH, basename(opts.device));
1037     }
1038
1039     server = qio_net_listener_new();
1040     if (socket_activation == 0) {
1041         int backlog;
1042
1043         if (persistent || shared == 0) {
1044             backlog = SOMAXCONN;
1045         } else {
1046             backlog = MIN(shared, SOMAXCONN);
1047         }
1048 #ifdef CONFIG_SELINUX
1049         if (selinux_label && setsockcreatecon_raw(selinux_label) == -1) {
1050             error_report("Cannot set SELinux socket create context to %s: %s",
1051                          selinux_label, strerror(errno));
1052             exit(EXIT_FAILURE);
1053         }
1054 #endif
1055         opts.saddr = nbd_build_socket_address(sockpath, bindto, port);
1056         if (qio_net_listener_open_sync(server, opts.saddr, backlog,
1057                                        &local_err) < 0) {
1058             object_unref(OBJECT(server));
1059             error_report_err(local_err);
1060             exit(EXIT_FAILURE);
1061         }
1062 #ifdef CONFIG_SELINUX
1063         if (selinux_label && setsockcreatecon_raw(NULL) == -1) {
1064             error_report("Cannot clear SELinux socket create context: %s",
1065                          strerror(errno));
1066             exit(EXIT_FAILURE);
1067         }
1068 #endif
1069     } else {
1070         size_t i;
1071         /* See comment in check_socket_activation above. */
1072         for (i = 0; i < socket_activation; i++) {
1073             QIOChannelSocket *sioc;
1074             sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
1075                                              &local_err);
1076             if (sioc == NULL) {
1077                 object_unref(OBJECT(server));
1078                 error_reportf_err(local_err,
1079                                   "Failed to use socket activation: ");
1080                 exit(EXIT_FAILURE);
1081             }
1082             qio_net_listener_add(server, sioc);
1083             object_unref(OBJECT(sioc));
1084         }
1085     }
1086
1087     qemu_init_main_loop(&error_fatal);
1088     bdrv_init();
1089     atexit(qemu_nbd_shutdown);
1090
1091     opts.srcpath = argv[optind];
1092     if (imageOpts) {
1093         QemuOpts *o;
1094         if (fmt) {
1095             error_report("--image-opts and -f are mutually exclusive");
1096             exit(EXIT_FAILURE);
1097         }
1098         o = qemu_opts_parse_noisily(&file_opts, opts.srcpath, true);
1099         if (!o) {
1100             qemu_opts_reset(&file_opts);
1101             exit(EXIT_FAILURE);
1102         }
1103         options = qemu_opts_to_qdict(o, NULL);
1104         qemu_opts_reset(&file_opts);
1105         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
1106     } else {
1107         if (fmt) {
1108             options = qdict_new();
1109             qdict_put_str(options, "driver", fmt);
1110         }
1111         blk = blk_new_open(opts.srcpath, NULL, options, flags, &local_err);
1112     }
1113
1114     if (!blk) {
1115         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
1116                           argv[optind]);
1117         exit(EXIT_FAILURE);
1118     }
1119     bs = blk_bs(blk);
1120
1121     if (dev_offset) {
1122         QDict *raw_opts = qdict_new();
1123         qdict_put_str(raw_opts, "driver", "raw");
1124         qdict_put_str(raw_opts, "file", bs->node_name);
1125         qdict_put_int(raw_opts, "offset", dev_offset);
1126
1127         bs = bdrv_open(NULL, NULL, raw_opts, flags, &error_fatal);
1128
1129         blk_remove_bs(blk);
1130         blk_insert_bs(blk, bs, &error_fatal);
1131         bdrv_unref(bs);
1132     }
1133
1134     blk_set_enable_write_cache(blk, !writethrough);
1135
1136     if (sn_opts) {
1137         ret = bdrv_snapshot_load_tmp(bs,
1138                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1139                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1140                                      &local_err);
1141     } else if (sn_id_or_name) {
1142         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1143                                                    &local_err);
1144     }
1145     if (ret < 0) {
1146         error_reportf_err(local_err, "Failed to load snapshot: ");
1147         exit(EXIT_FAILURE);
1148     }
1149
1150     bs->detect_zeroes = detect_zeroes;
1151
1152     nbd_server_is_qemu_nbd(shared);
1153
1154     export_opts = g_new(BlockExportOptions, 1);
1155     *export_opts = (BlockExportOptions) {
1156         .type               = BLOCK_EXPORT_TYPE_NBD,
1157         .id                 = g_strdup("qemu-nbd-export"),
1158         .node_name          = g_strdup(bdrv_get_node_name(bs)),
1159         .has_writethrough   = true,
1160         .writethrough       = writethrough,
1161         .has_writable       = true,
1162         .writable           = !readonly,
1163         .u.nbd = {
1164             .name                 = g_strdup(export_name),
1165             .description          = g_strdup(export_description),
1166             .has_bitmaps          = !!bitmaps,
1167             .bitmaps              = bitmaps,
1168             .has_allocation_depth = alloc_depth,
1169             .allocation_depth     = alloc_depth,
1170         },
1171     };
1172     blk_exp_add(export_opts, &error_fatal);
1173     qapi_free_BlockExportOptions(export_opts);
1174
1175     if (opts.device) {
1176 #if HAVE_NBD_DEVICE
1177         ret = pthread_create(&client_thread, NULL, nbd_client_thread, &opts);
1178         if (ret != 0) {
1179             error_report("Failed to create client thread: %s", strerror(ret));
1180             exit(EXIT_FAILURE);
1181         }
1182 #endif
1183     } else {
1184         /* Shut up GCC warnings.  */
1185         memset(&client_thread, 0, sizeof(client_thread));
1186     }
1187
1188     nbd_update_server_watch();
1189
1190     if (pid_file_name) {
1191         qemu_write_pidfile(pid_file_name, &error_fatal);
1192     }
1193
1194     /* now when the initialization is (almost) complete, chdir("/")
1195      * to free any busy filesystems */
1196     if (chdir("/") < 0) {
1197         error_report("Could not chdir to root directory: %s",
1198                      strerror(errno));
1199         exit(EXIT_FAILURE);
1200     }
1201
1202     if (opts.fork_process) {
1203         nbd_client_release_pipe(opts.old_stderr);
1204     }
1205
1206     state = RUNNING;
1207     do {
1208         main_loop_wait(false);
1209         if (state == TERMINATE) {
1210             blk_exp_close_all();
1211             state = TERMINATED;
1212         }
1213     } while (state != TERMINATED);
1214
1215     blk_unref(blk);
1216     if (sockpath) {
1217         unlink(sockpath);
1218     }
1219
1220     qemu_opts_del(sn_opts);
1221
1222     if (opts.device) {
1223         void *result;
1224         pthread_join(client_thread, &result);
1225         ret = (intptr_t)result;
1226         exit(ret);
1227     } else {
1228         exit(EXIT_SUCCESS);
1229     }
1230 }