qemu-nbd.c

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