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-common.h"
  20 #include "block/block.h"
  21 #include "block/nbd.h"
  22 #include "qemu/main-loop.h"
  23 #include "block/snapshot.h"
  24
  25 #include <stdarg.h>
  26 #include <stdio.h>
  27 #include <getopt.h>
  28 #include <err.h>
  29 #include <sys/types.h>
  30 #include <sys/socket.h>
  31 #include <netinet/in.h>
  32 #include <netinet/tcp.h>
  33 #include <arpa/inet.h>
  34 #include <signal.h>
  35 #include <libgen.h>
  36 #include <pthread.h>
  37
  38 #define SOCKET_PATH          "/var/lock/qemu-nbd-%s"
  39 #define QEMU_NBD_OPT_CACHE   1
  40 #define QEMU_NBD_OPT_AIO     2
  41 #define QEMU_NBD_OPT_DISCARD 3
  42
  43 static NBDExport *exp;
  44 static int verbose;
  45 static char *srcpath;
  46 static char *sockpath;
  47 static int persistent = 0;
  48 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
  49 static int shared = 1;
  50 static int nb_fds;
  51
  52 static void usage(const char *name)
  53 {
  54     (printf) (
  55 "Usage: %s [OPTIONS] FILE\n"
  56 "QEMU Disk Network Block Device Server\n"
  57 "\n"
  58 "  -h, --help           display this help and exit\n"
  59 "  -V, --version        output version information and exit\n"
  60 "\n"
  61 "Connection properties:\n"
  62 "  -p, --port=PORT      port to listen on (default `%d')\n"
  63 "  -b, --bind=IFACE     interface to bind to (default `0.0.0.0')\n"
  64 "  -k, --socket=PATH    path to the unix socket\n"
  65 "                       (default '"SOCKET_PATH"')\n"
  66 "  -e, --shared=NUM     device can be shared by NUM clients (default '1')\n"
  67 "  -t, --persistent     don't exit on the last connection\n"
  68 "  -v, --verbose        display extra debugging information\n"
  69 "\n"
  70 "Exposing part of the image:\n"
  71 "  -o, --offset=OFFSET  offset into the image\n"
  72 "  -P, --partition=NUM  only expose partition NUM\n"
  73 "\n"
  74 #ifdef __linux__
  75 "Kernel NBD client support:\n"
  76 "  -c, --connect=DEV    connect FILE to the local NBD device DEV\n"
  77 "  -d, --disconnect     disconnect the specified device\n"
  78 "\n"
  79 #endif
  80 "\n"
  81 "Block device options:\n"
  82 "  -f, --format=FORMAT  set image format (raw, qcow2, ...)\n"
  83 "  -r, --read-only      export read-only\n"
  84 "  -s, --snapshot       use FILE as an external snapshot, create a temporary\n"
  85 "                       file with backing_file=FILE, redirect the write to\n"
  86 "                       the temporary one\n"
  87 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
  88 "                       load an internal snapshot inside FILE and export it\n"
  89 "                       as an read-only device, SNAPSHOT_PARAM format is\n"
  90 "                       'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
  91 "                       '[ID_OR_NAME]'\n"
  92 "  -n, --nocache        disable host cache\n"
  93 "      --cache=MODE     set cache mode (none, writeback, ...)\n"
  94 #ifdef CONFIG_LINUX_AIO
  95 "      --aio=MODE       set AIO mode (native or threads)\n"
  96 #endif
  97 "\n"
  98 "Report bugs to <qemu-devel@nongnu.org>\n"
  99     , name, NBD_DEFAULT_PORT, "DEVICE");
 100 }
 101
 102 static void version(const char *name)
 103 {
 104     printf(
 105 "%s version 0.0.1\n"
 106 "Written by Anthony Liguori.\n"
 107 "\n"
 108 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
 109 "This is free software; see the source for copying conditions.  There is NO\n"
 110 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
 111     , name);
 112 }
 113
 114 struct partition_record
 115 {
 116     uint8_t bootable;
 117     uint8_t start_head;
 118     uint32_t start_cylinder;
 119     uint8_t start_sector;
 120     uint8_t system;
 121     uint8_t end_head;
 122     uint8_t end_cylinder;
 123     uint8_t end_sector;
 124     uint32_t start_sector_abs;
 125     uint32_t nb_sectors_abs;
 126 };
 127
 128 static void read_partition(uint8_t *p, struct partition_record *r)
 129 {
 130     r->bootable = p[0];
 131     r->start_head = p[1];
 132     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
 133     r->start_sector = p[2] & 0x3f;
 134     r->system = p[4];
 135     r->end_head = p[5];
 136     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
 137     r->end_sector = p[6] & 0x3f;
 138     r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24;
 139     r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24;
 140 }
 141
 142 static int find_partition(BlockDriverState *bs, int partition,
 143                           off_t *offset, off_t *size)
 144 {
 145     struct partition_record mbr[4];
 146     uint8_t data[512];
 147     int i;
 148     int ext_partnum = 4;
 149     int ret;
 150
 151     if ((ret = bdrv_read(bs, 0, data, 1)) < 0) {
 152         errno = -ret;
 153         err(EXIT_FAILURE, "error while reading");
 154     }
 155
 156     if (data[510] != 0x55 || data[511] != 0xaa) {
 157         return -EINVAL;
 158     }
 159
 160     for (i = 0; i < 4; i++) {
 161         read_partition(&data[446 + 16 * i], &mbr[i]);
 162
 163         if (!mbr[i].nb_sectors_abs)
 164             continue;
 165
 166         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
 167             struct partition_record ext[4];
 168             uint8_t data1[512];
 169             int j;
 170
 171             if ((ret = bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) < 0) {
 172                 errno = -ret;
 173                 err(EXIT_FAILURE, "error while reading");
 174             }
 175
 176             for (j = 0; j < 4; j++) {
 177                 read_partition(&data1[446 + 16 * j], &ext[j]);
 178                 if (!ext[j].nb_sectors_abs)
 179                     continue;
 180
 181                 if ((ext_partnum + j + 1) == partition) {
 182                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
 183                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
 184                     return 0;
 185                 }
 186             }
 187             ext_partnum += 4;
 188         } else if ((i + 1) == partition) {
 189             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
 190             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
 191             return 0;
 192         }
 193     }
 194
 195     return -ENOENT;
 196 }
 197
 198 static void termsig_handler(int signum)
 199 {
 200     state = TERMINATE;
 201     qemu_notify_event();
 202 }
 203
 204 static void *show_parts(void *arg)
 205 {
 206     char *device = arg;
 207     int nbd;
 208
 209     /* linux just needs an open() to trigger
 210      * the partition table update
 211      * but remember to load the module with max_part != 0 :
 212      *     modprobe nbd max_part=63
 213      */
 214     nbd = open(device, O_RDWR);
 215     if (nbd >= 0) {
 216         close(nbd);
 217     }
 218     return NULL;
 219 }
 220
 221 static void *nbd_client_thread(void *arg)
 222 {
 223     char *device = arg;
 224     off_t size;
 225     size_t blocksize;
 226     uint32_t nbdflags;
 227     int fd, sock;
 228     int ret;
 229     pthread_t show_parts_thread;
 230
 231     sock = unix_socket_outgoing(sockpath);
 232     if (sock < 0) {
 233         goto out;
 234     }
 235
 236     ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
 237                                 &size, &blocksize);
 238     if (ret < 0) {
 239         goto out;
 240     }
 241
 242     fd = open(device, O_RDWR);
 243     if (fd < 0) {
 244         /* Linux-only, we can use %m in printf.  */
 245         fprintf(stderr, "Failed to open %s: %m", device);
 246         goto out;
 247     }
 248
 249     ret = nbd_init(fd, sock, nbdflags, size, blocksize);
 250     if (ret < 0) {
 251         goto out;
 252     }
 253
 254     /* update partition table */
 255     pthread_create(&show_parts_thread, NULL, show_parts, device);
 256
 257     if (verbose) {
 258         fprintf(stderr, "NBD device %s is now connected to %s\n",
 259                 device, srcpath);
 260     } else {
 261         /* Close stderr so that the qemu-nbd process exits.  */
 262         dup2(STDOUT_FILENO, STDERR_FILENO);
 263     }
 264
 265     ret = nbd_client(fd);
 266     if (ret) {
 267         goto out;
 268     }
 269     close(fd);
 270     kill(getpid(), SIGTERM);
 271     return (void *) EXIT_SUCCESS;
 272
 273 out:
 274     kill(getpid(), SIGTERM);
 275     return (void *) EXIT_FAILURE;
 276 }
 277
 278 static int nbd_can_accept(void *opaque)
 279 {
 280     return nb_fds < shared;
 281 }
 282
 283 static void nbd_export_closed(NBDExport *exp)
 284 {
 285     assert(state == TERMINATING);
 286     state = TERMINATED;
 287 }
 288
 289 static void nbd_client_closed(NBDClient *client)
 290 {
 291     nb_fds--;
 292     if (nb_fds == 0 && !persistent && state == RUNNING) {
 293         state = TERMINATE;
 294     }
 295     qemu_notify_event();
 296     nbd_client_put(client);
 297 }
 298
 299 static void nbd_accept(void *opaque)
 300 {
 301     int server_fd = (uintptr_t) opaque;
 302     struct sockaddr_in addr;
 303     socklen_t addr_len = sizeof(addr);
 304
 305     int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
 306     if (state >= TERMINATE) {
 307         close(fd);
 308         return;
 309     }
 310
 311     if (fd >= 0 && nbd_client_new(exp, fd, nbd_client_closed)) {
 312         nb_fds++;
 313     }
 314 }
 315
 316 int main(int argc, char **argv)
 317 {
 318     BlockDriverState *bs;
 319     BlockDriver *drv;
 320     off_t dev_offset = 0;
 321     uint32_t nbdflags = 0;
 322     bool disconnect = false;
 323     const char *bindto = "0.0.0.0";
 324     char *device = NULL;
 325     int port = NBD_DEFAULT_PORT;
 326     off_t fd_size;
 327     QemuOpts *sn_opts = NULL;
 328     const char *sn_id_or_name = NULL;
 329     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:";
 330     struct option lopt[] = {
 331         { "help", 0, NULL, 'h' },
 332         { "version", 0, NULL, 'V' },
 333         { "bind", 1, NULL, 'b' },
 334         { "port", 1, NULL, 'p' },
 335         { "socket", 1, NULL, 'k' },
 336         { "offset", 1, NULL, 'o' },
 337         { "read-only", 0, NULL, 'r' },
 338         { "partition", 1, NULL, 'P' },
 339         { "connect", 1, NULL, 'c' },
 340         { "disconnect", 0, NULL, 'd' },
 341         { "snapshot", 0, NULL, 's' },
 342         { "load-snapshot", 1, NULL, 'l' },
 343         { "nocache", 0, NULL, 'n' },
 344         { "cache", 1, NULL, QEMU_NBD_OPT_CACHE },
 345 #ifdef CONFIG_LINUX_AIO
 346         { "aio", 1, NULL, QEMU_NBD_OPT_AIO },
 347 #endif
 348         { "discard", 1, NULL, QEMU_NBD_OPT_DISCARD },
 349         { "shared", 1, NULL, 'e' },
 350         { "format", 1, NULL, 'f' },
 351         { "persistent", 0, NULL, 't' },
 352         { "verbose", 0, NULL, 'v' },
 353         { NULL, 0, NULL, 0 }
 354     };
 355     int ch;
 356     int opt_ind = 0;
 357     int li;
 358     char *end;
 359     int flags = BDRV_O_RDWR;
 360     int partition = -1;
 361     int ret;
 362     int fd;
 363     bool seen_cache = false;
 364     bool seen_discard = false;
 365 #ifdef CONFIG_LINUX_AIO
 366     bool seen_aio = false;
 367 #endif
 368     pthread_t client_thread;
 369     const char *fmt = NULL;
 370     Error *local_err = NULL;
 371
 372     /* The client thread uses SIGTERM to interrupt the server.  A signal
 373      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
 374      */
 375     struct sigaction sa_sigterm;
 376     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
 377     sa_sigterm.sa_handler = termsig_handler;
 378     sigaction(SIGTERM, &sa_sigterm, NULL);
 379
 380     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
 381         switch (ch) {
 382         case 's':
 383             flags |= BDRV_O_SNAPSHOT;
 384             break;
 385         case 'n':
 386             optarg = (char *) "none";
 387             /* fallthrough */
 388         case QEMU_NBD_OPT_CACHE:
 389             if (seen_cache) {
 390                 errx(EXIT_FAILURE, "-n and --cache can only be specified once");
 391             }
 392             seen_cache = true;
 393             if (bdrv_parse_cache_flags(optarg, &flags) == -1) {
 394                 errx(EXIT_FAILURE, "Invalid cache mode `%s'", optarg);
 395             }
 396             break;
 397 #ifdef CONFIG_LINUX_AIO
 398         case QEMU_NBD_OPT_AIO:
 399             if (seen_aio) {
 400                 errx(EXIT_FAILURE, "--aio can only be specified once");
 401             }
 402             seen_aio = true;
 403             if (!strcmp(optarg, "native")) {
 404                 flags |= BDRV_O_NATIVE_AIO;
 405             } else if (!strcmp(optarg, "threads")) {
 406                 /* this is the default */
 407             } else {
 408                errx(EXIT_FAILURE, "invalid aio mode `%s'", optarg);
 409             }
 410             break;
 411 #endif
 412         case QEMU_NBD_OPT_DISCARD:
 413             if (seen_discard) {
 414                 errx(EXIT_FAILURE, "--discard can only be specified once");
 415             }
 416             seen_discard = true;
 417             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
 418                 errx(EXIT_FAILURE, "Invalid discard mode `%s'", optarg);
 419             }
 420             break;
 421         case 'b':
 422             bindto = optarg;
 423             break;
 424         case 'p':
 425             li = strtol(optarg, &end, 0);
 426             if (*end) {
 427                 errx(EXIT_FAILURE, "Invalid port `%s'", optarg);
 428             }
 429             if (li < 1 || li > 65535) {
 430                 errx(EXIT_FAILURE, "Port out of range `%s'", optarg);
 431             }
 432             port = (uint16_t)li;
 433             break;
 434         case 'o':
 435                 dev_offset = strtoll (optarg, &end, 0);
 436             if (*end) {
 437                 errx(EXIT_FAILURE, "Invalid offset `%s'", optarg);
 438             }
 439             if (dev_offset < 0) {
 440                 errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg);
 441             }
 442             break;
 443         case 'l':
 444             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
 445                 sn_opts = qemu_opts_parse(&internal_snapshot_opts, optarg, 0);
 446                 if (!sn_opts) {
 447                     errx(EXIT_FAILURE, "Failed in parsing snapshot param `%s'",
 448                          optarg);
 449                 }
 450             } else {
 451                 sn_id_or_name = optarg;
 452             }
 453             /* fall through */
 454         case 'r':
 455             nbdflags |= NBD_FLAG_READ_ONLY;
 456             flags &= ~BDRV_O_RDWR;
 457             break;
 458         case 'P':
 459             partition = strtol(optarg, &end, 0);
 460             if (*end)
 461                 errx(EXIT_FAILURE, "Invalid partition `%s'", optarg);
 462             if (partition < 1 || partition > 8)
 463                 errx(EXIT_FAILURE, "Invalid partition %d", partition);
 464             break;
 465         case 'k':
 466             sockpath = optarg;
 467             if (sockpath[0] != '/')
 468                 errx(EXIT_FAILURE, "socket path must be absolute\n");
 469             break;
 470         case 'd':
 471             disconnect = true;
 472             break;
 473         case 'c':
 474             device = optarg;
 475             break;
 476         case 'e':
 477             shared = strtol(optarg, &end, 0);
 478             if (*end) {
 479                 errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg);
 480             }
 481             if (shared < 1) {
 482                 errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
 483             }
 484             break;
 485         case 'f':
 486             fmt = optarg;
 487             break;
 488         case 't':
 489             persistent = 1;
 490             break;
 491         case 'v':
 492             verbose = 1;
 493             break;
 494         case 'V':
 495             version(argv[0]);
 496             exit(0);
 497             break;
 498         case 'h':
 499             usage(argv[0]);
 500             exit(0);
 501             break;
 502         case '?':
 503             errx(EXIT_FAILURE, "Try `%s --help' for more information.",
 504                  argv[0]);
 505         }
 506     }
 507
 508     if ((argc - optind) != 1) {
 509         errx(EXIT_FAILURE, "Invalid number of argument.\n"
 510              "Try `%s --help' for more information.",
 511              argv[0]);
 512     }
 513
 514     if (disconnect) {
 515         fd = open(argv[optind], O_RDWR);
 516         if (fd < 0) {
 517             err(EXIT_FAILURE, "Cannot open %s", argv[optind]);
 518         }
 519         nbd_disconnect(fd);
 520
 521         close(fd);
 522
 523         printf("%s disconnected\n", argv[optind]);
 524
 525         return 0;
 526     }
 527
 528     if (device && !verbose) {
 529         int stderr_fd[2];
 530         pid_t pid;
 531         int ret;
 532
 533         if (qemu_pipe(stderr_fd) < 0) {
 534             err(EXIT_FAILURE, "Error setting up communication pipe");
 535         }
 536
 537         /* Now daemonize, but keep a communication channel open to
 538          * print errors and exit with the proper status code.
 539          */
 540         pid = fork();
 541         if (pid == 0) {
 542             close(stderr_fd[0]);
 543             ret = qemu_daemon(1, 0);
 544
 545             /* Temporarily redirect stderr to the parent's pipe...  */
 546             dup2(stderr_fd[1], STDERR_FILENO);
 547             if (ret < 0) {
 548                 err(EXIT_FAILURE, "Failed to daemonize");
 549             }
 550
 551             /* ... close the descriptor we inherited and go on.  */
 552             close(stderr_fd[1]);
 553         } else {
 554             bool errors = false;
 555             char *buf;
 556
 557             /* In the parent.  Print error messages from the child until
 558              * it closes the pipe.
 559              */
 560             close(stderr_fd[1]);
 561             buf = g_malloc(1024);
 562             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
 563                 errors = true;
 564                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
 565                 if (ret < 0) {
 566                     exit(EXIT_FAILURE);
 567                 }
 568             }
 569             if (ret < 0) {
 570                 err(EXIT_FAILURE, "Cannot read from daemon");
 571             }
 572
 573             /* Usually the daemon should not print any message.
 574              * Exit with zero status in that case.
 575              */
 576             exit(errors);
 577         }
 578     }
 579
 580     if (device != NULL && sockpath == NULL) {
 581         sockpath = g_malloc(128);
 582         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
 583     }
 584
 585     qemu_init_main_loop();
 586     bdrv_init();
 587     atexit(bdrv_close_all);
 588
 589     if (fmt) {
 590         drv = bdrv_find_format(fmt);
 591         if (!drv) {
 592             errx(EXIT_FAILURE, "Unknown file format '%s'", fmt);
 593         }
 594     } else {
 595         drv = NULL;
 596     }
 597
 598     bs = bdrv_new("hda");
 599     srcpath = argv[optind];
 600     ret = bdrv_open(bs, srcpath, NULL, flags, drv, &local_err);
 601     if (ret < 0) {
 602         errno = -ret;
 603         err(EXIT_FAILURE, "Failed to bdrv_open '%s': %s", argv[optind],
 604             error_get_pretty(local_err));
 605     }
 606
 607     if (sn_opts) {
 608         ret = bdrv_snapshot_load_tmp(bs,
 609                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
 610                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
 611                                      &local_err);
 612     } else if (sn_id_or_name) {
 613         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
 614                                                    &local_err);
 615     }
 616     if (ret < 0) {
 617         errno = -ret;
 618         err(EXIT_FAILURE,
 619             "Failed to load snapshot: %s",
 620             error_get_pretty(local_err));
 621     }
 622
 623     fd_size = bdrv_getlength(bs);
 624
 625     if (partition != -1) {
 626         ret = find_partition(bs, partition, &dev_offset, &fd_size);
 627         if (ret < 0) {
 628             errno = -ret;
 629             err(EXIT_FAILURE, "Could not find partition %d", partition);
 630         }
 631     }
 632
 633     exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags, nbd_export_closed);
 634
 635     if (sockpath) {
 636         fd = unix_socket_incoming(sockpath);
 637     } else {
 638         fd = tcp_socket_incoming(bindto, port);
 639     }
 640
 641     if (fd < 0) {
 642         return 1;
 643     }
 644
 645     if (device) {
 646         int ret;
 647
 648         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
 649         if (ret != 0) {
 650             errx(EXIT_FAILURE, "Failed to create client thread: %s",
 651                  strerror(ret));
 652         }
 653     } else {
 654         /* Shut up GCC warnings.  */
 655         memset(&client_thread, 0, sizeof(client_thread));
 656     }
 657
 658     qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL,
 659                          (void *)(uintptr_t)fd);
 660
 661     /* now when the initialization is (almost) complete, chdir("/")
 662      * to free any busy filesystems */
 663     if (chdir("/") < 0) {
 664         err(EXIT_FAILURE, "Could not chdir to root directory");
 665     }
 666
 667     state = RUNNING;
 668     do {
 669         main_loop_wait(false);
 670         if (state == TERMINATE) {
 671             state = TERMINATING;
 672             nbd_export_close(exp);
 673             nbd_export_put(exp);
 674             exp = NULL;
 675         }
 676     } while (state != TERMINATED);
 677
 678     bdrv_close(bs);
 679     if (sockpath) {
 680         unlink(sockpath);
 681     }
 682
 683     if (sn_opts) {
 684         qemu_opts_del(sn_opts);
 685     }
 686
 687     if (device) {
 688         void *ret;
 689         pthread_join(client_thread, &ret);
 690         exit(ret != NULL);
 691     } else {
 692         exit(EXIT_SUCCESS);
 693     }
 694 }