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     /* TODO: Revisit this if nbd.ko ever gains support for structured reply */
 299     NBDExportInfo info = { .request_sizes = false, .name = g_strdup(""),
 300                            .mode = NBD_MODE_SIMPLE };
 301     QIOChannelSocket *sioc;
 302     int fd = -1;
 303     int ret = EXIT_FAILURE;
 304     pthread_t show_parts_thread;
 305     Error *local_error = NULL;
 306
 307     sioc = qio_channel_socket_new();
 308     if (qio_channel_socket_connect_sync(sioc,
 309                                         opts->saddr,
 310                                         &local_error) < 0) {
 311         error_report_err(local_error);
 312         goto out;
 313     }
 314
 315     if (nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, NULL, NULL,
 316                               &info, &local_error) < 0) {
 317         if (local_error) {
 318             error_report_err(local_error);
 319         }
 320         goto out;
 321     }
 322
 323     fd = open(opts->device, O_RDWR);
 324     if (fd < 0) {
 325         /* Linux-only, we can use %m in printf.  */
 326         error_report("Failed to open %s: %m", opts->device);
 327         goto out;
 328     }
 329
 330     if (nbd_init(fd, sioc, &info, &local_error) < 0) {
 331         error_report_err(local_error);
 332         goto out;
 333     }
 334
 335     /* update partition table */
 336     pthread_create(&show_parts_thread, NULL, show_parts, opts->device);
 337
 338     if (opts->verbose && !opts->fork_process) {
 339         fprintf(stderr, "NBD device %s is now connected to %s\n",
 340                 opts->device, opts->srcpath);
 341     } else {
 342         nbd_client_release_pipe(opts->old_stderr);
 343     }
 344
 345     if (nbd_client(fd) < 0) {
 346         goto out;
 347     }
 348
 349     ret = EXIT_SUCCESS;
 350
 351  out:
 352     if (fd >= 0) {
 353         close(fd);
 354     }
 355     object_unref(OBJECT(sioc));
 356     g_free(info.name);
 357     kill(getpid(), SIGTERM);
 358     return (void *) (intptr_t) ret;
 359 }
 360 #endif /* HAVE_NBD_DEVICE */
 361
 362 static int nbd_can_accept(void)
 363 {
 364     return state == RUNNING && (shared == 0 || nb_fds < shared);
 365 }
 366
 367 static void nbd_update_server_watch(void);
 368
 369 static void nbd_client_closed(NBDClient *client, bool negotiated)
 370 {
 371     nb_fds--;
 372     if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
 373         state = TERMINATE;
 374     }
 375     nbd_update_server_watch();
 376     nbd_client_put(client);
 377 }
 378
 379 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
 380                        gpointer opaque)
 381 {
 382     if (state >= TERMINATE) {
 383         return;
 384     }
 385
 386     nb_fds++;
 387     nbd_update_server_watch();
 388     nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
 389 }
 390
 391 static void nbd_update_server_watch(void)
 392 {
 393     if (nbd_can_accept()) {
 394         qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
 395     } else {
 396         qio_net_listener_set_client_func(server, NULL, NULL, NULL);
 397     }
 398 }
 399
 400
 401 static SocketAddress *nbd_build_socket_address(const char *sockpath,
 402                                                const char *bindto,
 403                                                const char *port)
 404 {
 405     SocketAddress *saddr;
 406
 407     saddr = g_new0(SocketAddress, 1);
 408     if (sockpath) {
 409         saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
 410         saddr->u.q_unix.path = g_strdup(sockpath);
 411     } else {
 412         InetSocketAddress *inet;
 413         saddr->type = SOCKET_ADDRESS_TYPE_INET;
 414         inet = &saddr->u.inet;
 415         inet->host = g_strdup(bindto);
 416         if (port) {
 417             inet->port = g_strdup(port);
 418         } else  {
 419             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 420         }
 421     }
 422
 423     return saddr;
 424 }
 425
 426
 427 static QemuOptsList file_opts = {
 428     .name = "file",
 429     .implied_opt_name = "file",
 430     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
 431     .desc = {
 432         /* no elements => accept any params */
 433         { /* end of list */ }
 434     },
 435 };
 436
 437 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
 438                                           Error **errp)
 439 {
 440     Object *obj;
 441     QCryptoTLSCreds *creds;
 442
 443     obj = object_resolve_path_component(
 444         object_get_objects_root(), id);
 445     if (!obj) {
 446         error_setg(errp, "No TLS credentials with id '%s'",
 447                    id);
 448         return NULL;
 449     }
 450     creds = (QCryptoTLSCreds *)
 451         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 452     if (!creds) {
 453         error_setg(errp, "Object with id '%s' is not TLS credentials",
 454                    id);
 455         return NULL;
 456     }
 457
 458     if (!qcrypto_tls_creds_check_endpoint(creds,
 459                                           list
 460                                           ? QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT
 461                                           : QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
 462                                           errp)) {
 463         return NULL;
 464     }
 465     object_ref(obj);
 466     return creds;
 467 }
 468
 469 static void setup_address_and_port(const char **address, const char **port)
 470 {
 471     if (*address == NULL) {
 472         *address = "0.0.0.0";
 473     }
 474
 475     if (*port == NULL) {
 476         *port = stringify(NBD_DEFAULT_PORT);
 477     }
 478 }
 479
 480 /*
 481  * Check socket parameters compatibility when socket activation is used.
 482  */
 483 static const char *socket_activation_validate_opts(const char *device,
 484                                                    const char *sockpath,
 485                                                    const char *address,
 486                                                    const char *port,
 487                                                    const char *selinux,
 488                                                    bool list)
 489 {
 490     if (device != NULL) {
 491         return "NBD device can't be set when using socket activation";
 492     }
 493
 494     if (sockpath != NULL) {
 495         return "Unix socket can't be set when using socket activation";
 496     }
 497
 498     if (address != NULL) {
 499         return "The interface can't be set when using socket activation";
 500     }
 501
 502     if (port != NULL) {
 503         return "TCP port number can't be set when using socket activation";
 504     }
 505
 506     if (selinux != NULL) {
 507         return "SELinux label can't be set when using socket activation";
 508     }
 509
 510     if (list) {
 511         return "List mode is incompatible with socket activation";
 512     }
 513
 514     return NULL;
 515 }
 516
 517 static void qemu_nbd_shutdown(void)
 518 {
 519     job_cancel_sync_all();
 520     blk_exp_close_all();
 521     bdrv_close_all();
 522 }
 523
 524 int main(int argc, char **argv)
 525 {
 526     BlockBackend *blk;
 527     BlockDriverState *bs;
 528     uint64_t dev_offset = 0;
 529     bool readonly = false;
 530     bool disconnect = false;
 531     const char *bindto = NULL;
 532     const char *port = NULL;
 533     char *sockpath = NULL;
 534     QemuOpts *sn_opts = NULL;
 535     const char *sn_id_or_name = NULL;
 536     const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:AB:L";
 537     struct option lopt[] = {
 538         { "help", no_argument, NULL, 'h' },
 539         { "version", no_argument, NULL, 'V' },
 540         { "bind", required_argument, NULL, 'b' },
 541         { "port", required_argument, NULL, 'p' },
 542         { "socket", required_argument, NULL, 'k' },
 543         { "offset", required_argument, NULL, 'o' },
 544         { "read-only", no_argument, NULL, 'r' },
 545         { "allocation-depth", no_argument, NULL, 'A' },
 546         { "bitmap", required_argument, NULL, 'B' },
 547         { "connect", required_argument, NULL, 'c' },
 548         { "disconnect", no_argument, NULL, 'd' },
 549         { "list", no_argument, NULL, 'L' },
 550         { "snapshot", no_argument, NULL, 's' },
 551         { "load-snapshot", required_argument, NULL, 'l' },
 552         { "nocache", no_argument, NULL, 'n' },
 553         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
 554         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
 555         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
 556         { "detect-zeroes", required_argument, NULL,
 557           QEMU_NBD_OPT_DETECT_ZEROES },
 558         { "shared", required_argument, NULL, 'e' },
 559         { "format", required_argument, NULL, 'f' },
 560         { "persistent", no_argument, NULL, 't' },
 561         { "verbose", no_argument, NULL, 'v' },
 562         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
 563         { "export-name", required_argument, NULL, 'x' },
 564         { "description", required_argument, NULL, 'D' },
 565         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
 566         { "tls-hostname", required_argument, NULL, QEMU_NBD_OPT_TLSHOSTNAME },
 567         { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
 568         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
 569         { "trace", required_argument, NULL, 'T' },
 570         { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
 571         { "pid-file", required_argument, NULL, QEMU_NBD_OPT_PID_FILE },
 572         { "selinux-label", required_argument, NULL,
 573           QEMU_NBD_OPT_SELINUX_LABEL },
 574         { NULL, 0, NULL, 0 }
 575     };
 576     int ch;
 577     int opt_ind = 0;
 578     int flags = BDRV_O_RDWR;
 579     int ret = 0;
 580     bool seen_cache = false;
 581     bool seen_discard = false;
 582     bool seen_aio = false;
 583     pthread_t client_thread;
 584     const char *fmt = NULL;
 585     Error *local_err = NULL;
 586     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
 587     QDict *options = NULL;
 588     const char *export_name = NULL; /* defaults to "" later for server mode */
 589     const char *export_description = NULL;
 590     BlockDirtyBitmapOrStrList *bitmaps = NULL;
 591     bool alloc_depth = false;
 592     const char *tlscredsid = NULL;
 593     const char *tlshostname = NULL;
 594     bool imageOpts = false;
 595     bool writethrough = false; /* Client will flush as needed. */
 596     bool list = false;
 597     unsigned socket_activation;
 598     const char *pid_file_name = NULL;
 599     const char *selinux_label = NULL;
 600     BlockExportOptions *export_opts;
 601     struct NbdClientOpts opts = {
 602         .fork_process = false,
 603         .verbose = false,
 604         .device = NULL,
 605         .srcpath = NULL,
 606         .saddr = NULL,
 607         .old_stderr = STDOUT_FILENO,
 608     };
 609
 610 #ifdef CONFIG_POSIX
 611     os_setup_early_signal_handling();
 612     os_setup_signal_handling();
 613 #endif
 614
 615     socket_init();
 616     error_init(argv[0]);
 617     module_call_init(MODULE_INIT_TRACE);
 618     qcrypto_init(&error_fatal);
 619
 620     module_call_init(MODULE_INIT_QOM);
 621     qemu_add_opts(&qemu_trace_opts);
 622     qemu_init_exec_dir(argv[0]);
 623
 624     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 625         switch (ch) {
 626         case 's':
 627             flags |= BDRV_O_SNAPSHOT;
 628             break;
 629         case 'n':
 630             optarg = (char *) "none";
 631             /* fallthrough */
 632         case QEMU_NBD_OPT_CACHE:
 633             if (seen_cache) {
 634                 error_report("-n and --cache can only be specified once");
 635                 exit(EXIT_FAILURE);
 636             }
 637             seen_cache = true;
 638             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
 639                 error_report("Invalid cache mode `%s'", optarg);
 640                 exit(EXIT_FAILURE);
 641             }
 642             break;
 643         case QEMU_NBD_OPT_AIO:
 644             if (seen_aio) {
 645                 error_report("--aio can only be specified once");
 646                 exit(EXIT_FAILURE);
 647             }
 648             seen_aio = true;
 649             if (bdrv_parse_aio(optarg, &flags) < 0) {
 650                 error_report("Invalid aio mode '%s'", optarg);
 651                 exit(EXIT_FAILURE);
 652             }
 653             break;
 654         case QEMU_NBD_OPT_DISCARD:
 655             if (seen_discard) {
 656                 error_report("--discard can only be specified once");
 657                 exit(EXIT_FAILURE);
 658             }
 659             seen_discard = true;
 660             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 661                 error_report("Invalid discard mode `%s'", optarg);
 662                 exit(EXIT_FAILURE);
 663             }
 664             break;
 665         case QEMU_NBD_OPT_DETECT_ZEROES:
 666             detect_zeroes =
 667                 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
 668                                 optarg,
 669                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
 670                                 &local_err);
 671             if (local_err) {
 672                 error_reportf_err(local_err,
 673                                   "Failed to parse detect_zeroes mode: ");
 674                 exit(EXIT_FAILURE);
 675             }
 676             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
 677                 !(flags & BDRV_O_UNMAP)) {
 678                 error_report("setting detect-zeroes to unmap is not allowed "
 679                              "without setting discard operation to unmap");
 680                 exit(EXIT_FAILURE);
 681             }
 682             break;
 683         case 'b':
 684             bindto = optarg;
 685             break;
 686         case 'p':
 687             port = optarg;
 688             break;
 689         case 'o':
 690             if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
 691                 error_report("Invalid offset '%s'", optarg);
 692                 exit(EXIT_FAILURE);
 693             }
 694             break;
 695         case 'l':
 696             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 697                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
 698                                                   optarg, false);
 699                 if (!sn_opts) {
 700                     error_report("Failed in parsing snapshot param `%s'",
 701                                  optarg);
 702                     exit(EXIT_FAILURE);
 703                 }
 704             } else {
 705                 sn_id_or_name = optarg;
 706             }
 707             /* fall through */
 708         case 'r':
 709             readonly = true;
 710             flags &= ~BDRV_O_RDWR;
 711             break;
 712         case 'A':
 713             alloc_depth = true;
 714             break;
 715         case 'B':
 716             {
 717                 BlockDirtyBitmapOrStr *el = g_new(BlockDirtyBitmapOrStr, 1);
 718                 *el = (BlockDirtyBitmapOrStr) {
 719                     .type = QTYPE_QSTRING,
 720                     .u.local = g_strdup(optarg),
 721                 };
 722                 QAPI_LIST_PREPEND(bitmaps, el);
 723             }
 724             break;
 725         case 'k':
 726             sockpath = optarg;
 727             if (sockpath[0] != '/') {
 728                 error_report("socket path must be absolute");
 729                 exit(EXIT_FAILURE);
 730             }
 731             break;
 732         case 'd':
 733             disconnect = true;
 734             break;
 735         case 'c':
 736             opts.device = optarg;
 737             break;
 738         case 'e':
 739             if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
 740                 shared < 0) {
 741                 error_report("Invalid shared device number '%s'", optarg);
 742                 exit(EXIT_FAILURE);
 743             }
 744             break;
 745         case 'f':
 746             fmt = optarg;
 747             break;
 748         case 't':
 749             persistent = 1;
 750             break;
 751         case 'x':
 752             export_name = optarg;
 753             if (strlen(export_name) > NBD_MAX_STRING_SIZE) {
 754                 error_report("export name '%s' too long", export_name);
 755                 exit(EXIT_FAILURE);
 756             }
 757             break;
 758         case 'D':
 759             export_description = optarg;
 760             if (strlen(export_description) > NBD_MAX_STRING_SIZE) {
 761                 error_report("export description '%s' too long",
 762                              export_description);
 763                 exit(EXIT_FAILURE);
 764             }
 765             break;
 766         case 'v':
 767             opts.verbose = true;
 768             break;
 769         case 'V':
 770             version(argv[0]);
 771             exit(0);
 772             break;
 773         case 'h':
 774             usage(argv[0]);
 775             exit(0);
 776             break;
 777         case '?':
 778             error_report("Try `%s --help' for more information.", argv[0]);
 779             exit(EXIT_FAILURE);
 780         case QEMU_NBD_OPT_OBJECT:
 781             user_creatable_process_cmdline(optarg);
 782             break;
 783         case QEMU_NBD_OPT_TLSCREDS:
 784             tlscredsid = optarg;
 785             break;
 786         case QEMU_NBD_OPT_TLSHOSTNAME:
 787             tlshostname = optarg;
 788             break;
 789         case QEMU_NBD_OPT_IMAGE_OPTS:
 790             imageOpts = true;
 791             break;
 792         case 'T':
 793             trace_opt_parse(optarg);
 794             break;
 795         case QEMU_NBD_OPT_TLSAUTHZ:
 796             tlsauthz = optarg;
 797             break;
 798         case QEMU_NBD_OPT_FORK:
 799             opts.fork_process = true;
 800             break;
 801         case 'L':
 802             list = true;
 803             break;
 804         case QEMU_NBD_OPT_PID_FILE:
 805             pid_file_name = optarg;
 806             break;
 807         case QEMU_NBD_OPT_SELINUX_LABEL:
 808             selinux_label = optarg;
 809             break;
 810         }
 811     }
 812
 813     if (list) {
 814         if (argc != optind) {
 815             error_report("List mode is incompatible with a file name");
 816             exit(EXIT_FAILURE);
 817         }
 818         if (export_name || export_description || dev_offset ||
 819             opts.device || disconnect || fmt || sn_id_or_name || bitmaps ||
 820             alloc_depth || seen_aio || seen_discard || seen_cache) {
 821             error_report("List mode is incompatible with per-device settings");
 822             exit(EXIT_FAILURE);
 823         }
 824         if (opts.fork_process) {
 825             error_report("List mode is incompatible with forking");
 826             exit(EXIT_FAILURE);
 827         }
 828     } else if ((argc - optind) != 1) {
 829         error_report("Invalid number of arguments");
 830         error_printf("Try `%s --help' for more information.\n", argv[0]);
 831         exit(EXIT_FAILURE);
 832     } else if (!export_name) {
 833         export_name = "";
 834     }
 835
 836     if (!trace_init_backends()) {
 837         exit(1);
 838     }
 839     trace_init_file();
 840     qemu_set_log(LOG_TRACE, &error_fatal);
 841
 842     socket_activation = check_socket_activation();
 843     if (socket_activation == 0) {
 844         if (!sockpath) {
 845             setup_address_and_port(&bindto, &port);
 846         }
 847     } else {
 848         /* Using socket activation - check user didn't use -p etc. */
 849         const char *err_msg = socket_activation_validate_opts(opts.device,
 850                                                               sockpath,
 851                                                               bindto, port,
 852                                                               selinux_label,
 853                                                               list);
 854         if (err_msg != NULL) {
 855             error_report("%s", err_msg);
 856             exit(EXIT_FAILURE);
 857         }
 858
 859         /* qemu-nbd can only listen on a single socket.  */
 860         if (socket_activation > 1) {
 861             error_report("qemu-nbd does not support socket activation with %s > 1",
 862                          "LISTEN_FDS");
 863             exit(EXIT_FAILURE);
 864         }
 865     }
 866
 867     if (tlscredsid) {
 868         if (opts.device) {
 869             error_report("TLS is not supported with a host device");
 870             exit(EXIT_FAILURE);
 871         }
 872         if (tlsauthz && list) {
 873             error_report("TLS authorization is incompatible with export list");
 874             exit(EXIT_FAILURE);
 875         }
 876         if (tlshostname && !list) {
 877             error_report("TLS hostname is only supported with export list");
 878             exit(EXIT_FAILURE);
 879         }
 880         tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
 881         if (local_err) {
 882             error_reportf_err(local_err, "Failed to get TLS creds: ");
 883             exit(EXIT_FAILURE);
 884         }
 885     } else {
 886         if (tlsauthz) {
 887             error_report("--tls-authz is not permitted without --tls-creds");
 888             exit(EXIT_FAILURE);
 889         }
 890         if (tlshostname) {
 891             error_report("--tls-hostname is not permitted without --tls-creds");
 892             exit(EXIT_FAILURE);
 893         }
 894     }
 895
 896     if (selinux_label) {
 897 #ifdef CONFIG_SELINUX
 898         if (sockpath == NULL && opts.device == NULL) {
 899             error_report("--selinux-label is not permitted without --socket");
 900             exit(EXIT_FAILURE);
 901         }
 902 #else
 903         error_report("SELinux support not enabled in this binary");
 904         exit(EXIT_FAILURE);
 905 #endif
 906     }
 907
 908     if (list) {
 909         opts.saddr = nbd_build_socket_address(sockpath, bindto, port);
 910         return qemu_nbd_client_list(opts.saddr, tlscreds,
 911                                     tlshostname ? tlshostname : bindto);
 912     }
 913
 914 #if !HAVE_NBD_DEVICE
 915     if (disconnect || opts.device) {
 916         error_report("Kernel /dev/nbdN support not available");
 917         exit(EXIT_FAILURE);
 918     }
 919 #else /* HAVE_NBD_DEVICE */
 920     if (disconnect) {
 921         int nbdfd = open(argv[optind], O_RDWR);
 922         if (nbdfd < 0) {
 923             error_report("Cannot open %s: %s", argv[optind],
 924                          strerror(errno));
 925             exit(EXIT_FAILURE);
 926         }
 927         nbd_disconnect(nbdfd);
 928
 929         close(nbdfd);
 930
 931         printf("%s disconnected\n", argv[optind]);
 932
 933         return 0;
 934     }
 935 #endif
 936
 937     if ((opts.device && !opts.verbose) || opts.fork_process) {
 938 #ifndef WIN32
 939         g_autoptr(GError) err = NULL;
 940         int stderr_fd[2];
 941         pid_t pid;
 942         int ret;
 943
 944         if (!g_unix_open_pipe(stderr_fd, FD_CLOEXEC, &err)) {
 945             error_report("Error setting up communication pipe: %s",
 946                          err->message);
 947             exit(EXIT_FAILURE);
 948         }
 949
 950         /* Now daemonize, but keep a communication channel open to
 951          * print errors and exit with the proper status code.
 952          */
 953         pid = fork();
 954         if (pid < 0) {
 955             error_report("Failed to fork: %s", strerror(errno));
 956             exit(EXIT_FAILURE);
 957         } else if (pid == 0) {
 958             int saved_errno;
 959
 960             close(stderr_fd[0]);
 961
 962             /* Remember parent's stderr if we will be restoring it. */
 963             if (opts.verbose /* fork_process is set */) {
 964                 opts.old_stderr = dup(STDERR_FILENO);
 965                 if (opts.old_stderr < 0) {
 966                     error_report("Could not dup original stderr: %s",
 967                                  strerror(errno));
 968                     exit(EXIT_FAILURE);
 969                 }
 970             }
 971
 972             ret = qemu_daemon(1, 0);
 973             saved_errno = errno;    /* dup2 will overwrite error below */
 974
 975             /* Temporarily redirect stderr to the parent's pipe...  */
 976             if (dup2(stderr_fd[1], STDERR_FILENO) < 0) {
 977                 char str[256];
 978                 snprintf(str, sizeof(str),
 979                          "%s: Failed to link stderr to the pipe: %s\n",
 980                          g_get_prgname(), strerror(errno));
 981                 /*
 982                  * We are unable to use error_report() here as we need to get
 983                  * stderr pointed to the parent's pipe. Write to that pipe
 984                  * manually.
 985                  */
 986                 ret = write(stderr_fd[1], str, strlen(str));
 987                 exit(EXIT_FAILURE);
 988             }
 989
 990             if (ret < 0) {
 991                 error_report("Failed to daemonize: %s", strerror(saved_errno));
 992                 exit(EXIT_FAILURE);
 993             }
 994
 995             /* ... close the descriptor we inherited and go on.  */
 996             close(stderr_fd[1]);
 997         } else {
 998             bool errors = false;
 999             char *buf;
1000
1001             /* In the parent.  Print error messages from the child until
1002              * it closes the pipe.
1003              */
1004             close(stderr_fd[1]);
1005             buf = g_malloc(1024);
1006             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
1007                 errors = true;
1008                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
1009                 if (ret < 0) {
1010                     exit(EXIT_FAILURE);
1011                 }
1012             }
1013             if (ret < 0) {
1014                 error_report("Cannot read from daemon: %s",
1015                              strerror(errno));
1016                 exit(EXIT_FAILURE);
1017             }
1018
1019             /* Usually the daemon should not print any message.
1020              * Exit with zero status in that case.
1021              */
1022             exit(errors);
1023         }
1024 #else /* WIN32 */
1025         error_report("Unable to fork into background on Windows hosts");
1026         exit(EXIT_FAILURE);
1027 #endif /* WIN32 */
1028     }
1029
1030     if (opts.device != NULL && sockpath == NULL) {
1031         sockpath = g_malloc(128);
1032         snprintf(sockpath, 128, SOCKET_PATH, basename(opts.device));
1033     }
1034
1035     server = qio_net_listener_new();
1036     if (socket_activation == 0) {
1037         int backlog;
1038
1039         if (persistent || shared == 0) {
1040             backlog = SOMAXCONN;
1041         } else {
1042             backlog = MIN(shared, SOMAXCONN);
1043         }
1044 #ifdef CONFIG_SELINUX
1045         if (selinux_label && setsockcreatecon_raw(selinux_label) == -1) {
1046             error_report("Cannot set SELinux socket create context to %s: %s",
1047                          selinux_label, strerror(errno));
1048             exit(EXIT_FAILURE);
1049         }
1050 #endif
1051         opts.saddr = nbd_build_socket_address(sockpath, bindto, port);
1052         if (qio_net_listener_open_sync(server, opts.saddr, backlog,
1053                                        &local_err) < 0) {
1054             object_unref(OBJECT(server));
1055             error_report_err(local_err);
1056             exit(EXIT_FAILURE);
1057         }
1058 #ifdef CONFIG_SELINUX
1059         if (selinux_label && setsockcreatecon_raw(NULL) == -1) {
1060             error_report("Cannot clear SELinux socket create context: %s",
1061                          strerror(errno));
1062             exit(EXIT_FAILURE);
1063         }
1064 #endif
1065     } else {
1066         size_t i;
1067         /* See comment in check_socket_activation above. */
1068         for (i = 0; i < socket_activation; i++) {
1069             QIOChannelSocket *sioc;
1070             sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
1071                                              &local_err);
1072             if (sioc == NULL) {
1073                 object_unref(OBJECT(server));
1074                 error_reportf_err(local_err,
1075                                   "Failed to use socket activation: ");
1076                 exit(EXIT_FAILURE);
1077             }
1078             qio_net_listener_add(server, sioc);
1079             object_unref(OBJECT(sioc));
1080         }
1081     }
1082
1083     qemu_init_main_loop(&error_fatal);
1084     bdrv_init();
1085     atexit(qemu_nbd_shutdown);
1086
1087     opts.srcpath = argv[optind];
1088     if (imageOpts) {
1089         QemuOpts *o;
1090         if (fmt) {
1091             error_report("--image-opts and -f are mutually exclusive");
1092             exit(EXIT_FAILURE);
1093         }
1094         o = qemu_opts_parse_noisily(&file_opts, opts.srcpath, true);
1095         if (!o) {
1096             qemu_opts_reset(&file_opts);
1097             exit(EXIT_FAILURE);
1098         }
1099         options = qemu_opts_to_qdict(o, NULL);
1100         qemu_opts_reset(&file_opts);
1101         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
1102     } else {
1103         if (fmt) {
1104             options = qdict_new();
1105             qdict_put_str(options, "driver", fmt);
1106         }
1107         blk = blk_new_open(opts.srcpath, NULL, options, flags, &local_err);
1108     }
1109
1110     if (!blk) {
1111         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
1112                           argv[optind]);
1113         exit(EXIT_FAILURE);
1114     }
1115     bs = blk_bs(blk);
1116
1117     if (dev_offset) {
1118         QDict *raw_opts = qdict_new();
1119         qdict_put_str(raw_opts, "driver", "raw");
1120         qdict_put_str(raw_opts, "file", bs->node_name);
1121         qdict_put_int(raw_opts, "offset", dev_offset);
1122
1123         aio_context_acquire(qemu_get_aio_context());
1124         bs = bdrv_open(NULL, NULL, raw_opts, flags, &error_fatal);
1125         aio_context_release(qemu_get_aio_context());
1126
1127         blk_remove_bs(blk);
1128         blk_insert_bs(blk, bs, &error_fatal);
1129         bdrv_unref(bs);
1130     }
1131
1132     blk_set_enable_write_cache(blk, !writethrough);
1133
1134     if (sn_opts) {
1135         ret = bdrv_snapshot_load_tmp(bs,
1136                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1137                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1138                                      &local_err);
1139     } else if (sn_id_or_name) {
1140         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1141                                                    &local_err);
1142     }
1143     if (ret < 0) {
1144         error_reportf_err(local_err, "Failed to load snapshot: ");
1145         exit(EXIT_FAILURE);
1146     }
1147
1148     bs->detect_zeroes = detect_zeroes;
1149
1150     nbd_server_is_qemu_nbd(shared);
1151
1152     export_opts = g_new(BlockExportOptions, 1);
1153     *export_opts = (BlockExportOptions) {
1154         .type               = BLOCK_EXPORT_TYPE_NBD,
1155         .id                 = g_strdup("qemu-nbd-export"),
1156         .node_name          = g_strdup(bdrv_get_node_name(bs)),
1157         .has_writethrough   = true,
1158         .writethrough       = writethrough,
1159         .has_writable       = true,
1160         .writable           = !readonly,
1161         .u.nbd = {
1162             .name                 = g_strdup(export_name),
1163             .description          = g_strdup(export_description),
1164             .has_bitmaps          = !!bitmaps,
1165             .bitmaps              = bitmaps,
1166             .has_allocation_depth = alloc_depth,
1167             .allocation_depth     = alloc_depth,
1168         },
1169     };
1170     blk_exp_add(export_opts, &error_fatal);
1171     qapi_free_BlockExportOptions(export_opts);
1172
1173     if (opts.device) {
1174 #if HAVE_NBD_DEVICE
1175         int ret;
1176         ret = pthread_create(&client_thread, NULL, nbd_client_thread, &opts);
1177         if (ret != 0) {
1178             error_report("Failed to create client thread: %s", strerror(ret));
1179             exit(EXIT_FAILURE);
1180         }
1181 #endif
1182     } else {
1183         /* Shut up GCC warnings.  */
1184         memset(&client_thread, 0, sizeof(client_thread));
1185     }
1186
1187     nbd_update_server_watch();
1188
1189     if (pid_file_name) {
1190         qemu_write_pidfile(pid_file_name, &error_fatal);
1191     }
1192
1193     /* now when the initialization is (almost) complete, chdir("/")
1194      * to free any busy filesystems */
1195     if (chdir("/") < 0) {
1196         error_report("Could not chdir to root directory: %s",
1197                      strerror(errno));
1198         exit(EXIT_FAILURE);
1199     }
1200
1201     if (opts.fork_process) {
1202         nbd_client_release_pipe(opts.old_stderr);
1203     }
1204
1205     state = RUNNING;
1206     do {
1207         main_loop_wait(false);
1208         if (state == TERMINATE) {
1209             blk_exp_close_all();
1210             state = TERMINATED;
1211         }
1212     } while (state != TERMINATED);
1213
1214     blk_unref(blk);
1215     if (sockpath) {
1216         unlink(sockpath);
1217     }
1218
1219     qemu_opts_del(sn_opts);
1220
1221     if (opts.device) {
1222         void *ret;
1223         pthread_join(client_thread, &ret);
1224         exit(ret != NULL);
1225     } else {
1226         exit(EXIT_SUCCESS);
1227     }
1228 }