xref: /openbmc/qemu/qemu-nbd.c (revision 39de9984)
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 "qemu-common.h"
21 #include "sysemu/block-backend.h"
22 #include "block/block_int.h"
23 #include "block/nbd.h"
24 #include "qemu/main-loop.h"
25 #include "qemu/error-report.h"
26 #include "qemu/config-file.h"
27 #include "block/snapshot.h"
28 #include "qapi/util.h"
29 #include "qapi/qmp/qstring.h"
30 #include "qom/object_interfaces.h"
31 #include "io/channel-socket.h"
32 
33 #include <getopt.h>
34 #include <sys/types.h>
35 #include <signal.h>
36 #include <libgen.h>
37 #include <pthread.h>
38 
39 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
40 #define QEMU_NBD_OPT_CACHE         256
41 #define QEMU_NBD_OPT_AIO           257
42 #define QEMU_NBD_OPT_DISCARD       258
43 #define QEMU_NBD_OPT_DETECT_ZEROES 259
44 #define QEMU_NBD_OPT_OBJECT        260
45 #define QEMU_NBD_OPT_TLSCREDS      261
46 #define QEMU_NBD_OPT_IMAGE_OPTS    262
47 
48 static NBDExport *exp;
49 static bool newproto;
50 static int verbose;
51 static char *srcpath;
52 static SocketAddress *saddr;
53 static int persistent = 0;
54 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
55 static int shared = 1;
56 static int nb_fds;
57 static QIOChannelSocket *server_ioc;
58 static int server_watch = -1;
59 static QCryptoTLSCreds *tlscreds;
60 
61 static void usage(const char *name)
62 {
63     (printf) (
64 "Usage: %s [OPTIONS] FILE\n"
65 "QEMU Disk Network Block Device Server\n"
66 "\n"
67 "  -h, --help                display this help and exit\n"
68 "  -V, --version             output version information and exit\n"
69 "\n"
70 "Connection properties:\n"
71 "  -p, --port=PORT           port to listen on (default `%d')\n"
72 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
73 "  -k, --socket=PATH         path to the unix socket\n"
74 "                            (default '"SOCKET_PATH"')\n"
75 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
76 "  -t, --persistent          don't exit on the last connection\n"
77 "  -v, --verbose             display extra debugging information\n"
78 "\n"
79 "Exposing part of the image:\n"
80 "  -o, --offset=OFFSET       offset into the image\n"
81 "  -P, --partition=NUM       only expose partition NUM\n"
82 "\n"
83 "General purpose options:\n"
84 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
85 "                            passwords and/or encryption keys\n"
86 #ifdef __linux__
87 "Kernel NBD client support:\n"
88 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
89 "  -d, --disconnect          disconnect the specified device\n"
90 "\n"
91 #endif
92 "\n"
93 "Block device options:\n"
94 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
95 "  -r, --read-only           export read-only\n"
96 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
97 "                            file with backing_file=FILE, redirect the write to\n"
98 "                            the temporary one\n"
99 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
100 "                            load an internal snapshot inside FILE and export it\n"
101 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
102 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
103 "                            '[ID_OR_NAME]'\n"
104 "  -n, --nocache             disable host cache\n"
105 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
106 "      --aio=MODE            set AIO mode (native or threads)\n"
107 "      --discard=MODE        set discard mode (ignore, unmap)\n"
108 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
109 "      --image-opts          treat FILE as a full set of image options\n"
110 "\n"
111 "Report bugs to <qemu-devel@nongnu.org>\n"
112     , name, NBD_DEFAULT_PORT, "DEVICE");
113 }
114 
115 static void version(const char *name)
116 {
117     printf(
118 "%s version 0.0.1\n"
119 "Written by Anthony Liguori.\n"
120 "\n"
121 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
122 "This is free software; see the source for copying conditions.  There is NO\n"
123 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
124     , name);
125 }
126 
127 struct partition_record
128 {
129     uint8_t bootable;
130     uint8_t start_head;
131     uint32_t start_cylinder;
132     uint8_t start_sector;
133     uint8_t system;
134     uint8_t end_head;
135     uint8_t end_cylinder;
136     uint8_t end_sector;
137     uint32_t start_sector_abs;
138     uint32_t nb_sectors_abs;
139 };
140 
141 static void read_partition(uint8_t *p, struct partition_record *r)
142 {
143     r->bootable = p[0];
144     r->start_head = p[1];
145     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
146     r->start_sector = p[2] & 0x3f;
147     r->system = p[4];
148     r->end_head = p[5];
149     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
150     r->end_sector = p[6] & 0x3f;
151 
152     r->start_sector_abs = le32_to_cpup((uint32_t *)(p +  8));
153     r->nb_sectors_abs   = le32_to_cpup((uint32_t *)(p + 12));
154 }
155 
156 static int find_partition(BlockBackend *blk, int partition,
157                           off_t *offset, off_t *size)
158 {
159     struct partition_record mbr[4];
160     uint8_t data[512];
161     int i;
162     int ext_partnum = 4;
163     int ret;
164 
165     if ((ret = blk_read(blk, 0, data, 1)) < 0) {
166         error_report("error while reading: %s", strerror(-ret));
167         exit(EXIT_FAILURE);
168     }
169 
170     if (data[510] != 0x55 || data[511] != 0xaa) {
171         return -EINVAL;
172     }
173 
174     for (i = 0; i < 4; i++) {
175         read_partition(&data[446 + 16 * i], &mbr[i]);
176 
177         if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
178             continue;
179         }
180 
181         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
182             struct partition_record ext[4];
183             uint8_t data1[512];
184             int j;
185 
186             if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) {
187                 error_report("error while reading: %s", strerror(-ret));
188                 exit(EXIT_FAILURE);
189             }
190 
191             for (j = 0; j < 4; j++) {
192                 read_partition(&data1[446 + 16 * j], &ext[j]);
193                 if (!ext[j].system || !ext[j].nb_sectors_abs) {
194                     continue;
195                 }
196 
197                 if ((ext_partnum + j + 1) == partition) {
198                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
199                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
200                     return 0;
201                 }
202             }
203             ext_partnum += 4;
204         } else if ((i + 1) == partition) {
205             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
206             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
207             return 0;
208         }
209     }
210 
211     return -ENOENT;
212 }
213 
214 static void termsig_handler(int signum)
215 {
216     state = TERMINATE;
217     qemu_notify_event();
218 }
219 
220 
221 static void *show_parts(void *arg)
222 {
223     char *device = arg;
224     int nbd;
225 
226     /* linux just needs an open() to trigger
227      * the partition table update
228      * but remember to load the module with max_part != 0 :
229      *     modprobe nbd max_part=63
230      */
231     nbd = open(device, O_RDWR);
232     if (nbd >= 0) {
233         close(nbd);
234     }
235     return NULL;
236 }
237 
238 static void *nbd_client_thread(void *arg)
239 {
240     char *device = arg;
241     off_t size;
242     uint32_t nbdflags;
243     QIOChannelSocket *sioc;
244     int fd;
245     int ret;
246     pthread_t show_parts_thread;
247     Error *local_error = NULL;
248 
249     sioc = qio_channel_socket_new();
250     if (qio_channel_socket_connect_sync(sioc,
251                                         saddr,
252                                         &local_error) < 0) {
253         error_report_err(local_error);
254         goto out;
255     }
256 
257     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, &nbdflags,
258                                 NULL, NULL, NULL,
259                                 &size, &local_error);
260     if (ret < 0) {
261         if (local_error) {
262             error_report_err(local_error);
263         }
264         goto out_socket;
265     }
266 
267     fd = open(device, O_RDWR);
268     if (fd < 0) {
269         /* Linux-only, we can use %m in printf.  */
270         error_report("Failed to open %s: %m", device);
271         goto out_socket;
272     }
273 
274     ret = nbd_init(fd, sioc, nbdflags, size);
275     if (ret < 0) {
276         goto out_fd;
277     }
278 
279     /* update partition table */
280     pthread_create(&show_parts_thread, NULL, show_parts, device);
281 
282     if (verbose) {
283         fprintf(stderr, "NBD device %s is now connected to %s\n",
284                 device, srcpath);
285     } else {
286         /* Close stderr so that the qemu-nbd process exits.  */
287         dup2(STDOUT_FILENO, STDERR_FILENO);
288     }
289 
290     ret = nbd_client(fd);
291     if (ret) {
292         goto out_fd;
293     }
294     close(fd);
295     object_unref(OBJECT(sioc));
296     kill(getpid(), SIGTERM);
297     return (void *) EXIT_SUCCESS;
298 
299 out_fd:
300     close(fd);
301 out_socket:
302     object_unref(OBJECT(sioc));
303 out:
304     kill(getpid(), SIGTERM);
305     return (void *) EXIT_FAILURE;
306 }
307 
308 static int nbd_can_accept(void)
309 {
310     return nb_fds < shared;
311 }
312 
313 static void nbd_export_closed(NBDExport *exp)
314 {
315     assert(state == TERMINATING);
316     state = TERMINATED;
317 }
318 
319 static void nbd_update_server_watch(void);
320 
321 static void nbd_client_closed(NBDClient *client)
322 {
323     nb_fds--;
324     if (nb_fds == 0 && !persistent && state == RUNNING) {
325         state = TERMINATE;
326     }
327     nbd_update_server_watch();
328     nbd_client_put(client);
329 }
330 
331 static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque)
332 {
333     QIOChannelSocket *cioc;
334 
335     cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
336                                      NULL);
337     if (!cioc) {
338         return TRUE;
339     }
340 
341     if (state >= TERMINATE) {
342         object_unref(OBJECT(cioc));
343         return TRUE;
344     }
345 
346     nb_fds++;
347     nbd_update_server_watch();
348     nbd_client_new(newproto ? NULL : exp, cioc,
349                    tlscreds, NULL, nbd_client_closed);
350     object_unref(OBJECT(cioc));
351 
352     return TRUE;
353 }
354 
355 static void nbd_update_server_watch(void)
356 {
357     if (nbd_can_accept()) {
358         if (server_watch == -1) {
359             server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc),
360                                                  G_IO_IN,
361                                                  nbd_accept,
362                                                  NULL, NULL);
363         }
364     } else {
365         if (server_watch != -1) {
366             g_source_remove(server_watch);
367             server_watch = -1;
368         }
369     }
370 }
371 
372 
373 static SocketAddress *nbd_build_socket_address(const char *sockpath,
374                                                const char *bindto,
375                                                const char *port)
376 {
377     SocketAddress *saddr;
378 
379     saddr = g_new0(SocketAddress, 1);
380     if (sockpath) {
381         saddr->type = SOCKET_ADDRESS_KIND_UNIX;
382         saddr->u.q_unix = g_new0(UnixSocketAddress, 1);
383         saddr->u.q_unix->path = g_strdup(sockpath);
384     } else {
385         saddr->type = SOCKET_ADDRESS_KIND_INET;
386         saddr->u.inet = g_new0(InetSocketAddress, 1);
387         saddr->u.inet->host = g_strdup(bindto);
388         if (port) {
389             saddr->u.inet->port = g_strdup(port);
390         } else  {
391             saddr->u.inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
392         }
393     }
394 
395     return saddr;
396 }
397 
398 
399 static QemuOptsList file_opts = {
400     .name = "file",
401     .implied_opt_name = "file",
402     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
403     .desc = {
404         /* no elements => accept any params */
405         { /* end of list */ }
406     },
407 };
408 
409 static QemuOptsList qemu_object_opts = {
410     .name = "object",
411     .implied_opt_name = "qom-type",
412     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
413     .desc = {
414         { }
415     },
416 };
417 
418 
419 
420 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
421 {
422     Object *obj;
423     QCryptoTLSCreds *creds;
424 
425     obj = object_resolve_path_component(
426         object_get_objects_root(), id);
427     if (!obj) {
428         error_setg(errp, "No TLS credentials with id '%s'",
429                    id);
430         return NULL;
431     }
432     creds = (QCryptoTLSCreds *)
433         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
434     if (!creds) {
435         error_setg(errp, "Object with id '%s' is not TLS credentials",
436                    id);
437         return NULL;
438     }
439 
440     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
441         error_setg(errp,
442                    "Expecting TLS credentials with a server endpoint");
443         return NULL;
444     }
445     object_ref(obj);
446     return creds;
447 }
448 
449 
450 int main(int argc, char **argv)
451 {
452     BlockBackend *blk;
453     BlockDriverState *bs;
454     off_t dev_offset = 0;
455     uint32_t nbdflags = 0;
456     bool disconnect = false;
457     const char *bindto = "0.0.0.0";
458     const char *port = NULL;
459     char *sockpath = NULL;
460     char *device = NULL;
461     off_t fd_size;
462     QemuOpts *sn_opts = NULL;
463     const char *sn_id_or_name = NULL;
464     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:";
465     struct option lopt[] = {
466         { "help", no_argument, NULL, 'h' },
467         { "version", no_argument, NULL, 'V' },
468         { "bind", required_argument, NULL, 'b' },
469         { "port", required_argument, NULL, 'p' },
470         { "socket", required_argument, NULL, 'k' },
471         { "offset", required_argument, NULL, 'o' },
472         { "read-only", no_argument, NULL, 'r' },
473         { "partition", required_argument, NULL, 'P' },
474         { "connect", required_argument, NULL, 'c' },
475         { "disconnect", no_argument, NULL, 'd' },
476         { "snapshot", no_argument, NULL, 's' },
477         { "load-snapshot", required_argument, NULL, 'l' },
478         { "nocache", no_argument, NULL, 'n' },
479         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
480         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
481         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
482         { "detect-zeroes", required_argument, NULL,
483           QEMU_NBD_OPT_DETECT_ZEROES },
484         { "shared", required_argument, NULL, 'e' },
485         { "format", required_argument, NULL, 'f' },
486         { "persistent", no_argument, NULL, 't' },
487         { "verbose", no_argument, NULL, 'v' },
488         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
489         { "export-name", required_argument, NULL, 'x' },
490         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
491         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
492         { NULL, 0, NULL, 0 }
493     };
494     int ch;
495     int opt_ind = 0;
496     char *end;
497     int flags = BDRV_O_RDWR;
498     int partition = -1;
499     int ret = 0;
500     bool seen_cache = false;
501     bool seen_discard = false;
502     bool seen_aio = false;
503     pthread_t client_thread;
504     const char *fmt = NULL;
505     Error *local_err = NULL;
506     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
507     QDict *options = NULL;
508     const char *export_name = NULL;
509     const char *tlscredsid = NULL;
510     bool imageOpts = false;
511 
512     /* The client thread uses SIGTERM to interrupt the server.  A signal
513      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
514      */
515     struct sigaction sa_sigterm;
516     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
517     sa_sigterm.sa_handler = termsig_handler;
518     sigaction(SIGTERM, &sa_sigterm, NULL);
519     module_call_init(MODULE_INIT_QOM);
520     qemu_add_opts(&qemu_object_opts);
521     qemu_init_exec_dir(argv[0]);
522 
523     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
524         switch (ch) {
525         case 's':
526             flags |= BDRV_O_SNAPSHOT;
527             break;
528         case 'n':
529             optarg = (char *) "none";
530             /* fallthrough */
531         case QEMU_NBD_OPT_CACHE:
532             if (seen_cache) {
533                 error_report("-n and --cache can only be specified once");
534                 exit(EXIT_FAILURE);
535             }
536             seen_cache = true;
537             if (bdrv_parse_cache_flags(optarg, &flags) == -1) {
538                 error_report("Invalid cache mode `%s'", optarg);
539                 exit(EXIT_FAILURE);
540             }
541             break;
542         case QEMU_NBD_OPT_AIO:
543             if (seen_aio) {
544                 error_report("--aio can only be specified once");
545                 exit(EXIT_FAILURE);
546             }
547             seen_aio = true;
548             if (!strcmp(optarg, "native")) {
549                 flags |= BDRV_O_NATIVE_AIO;
550             } else if (!strcmp(optarg, "threads")) {
551                 /* this is the default */
552             } else {
553                error_report("invalid aio mode `%s'", optarg);
554                exit(EXIT_FAILURE);
555             }
556             break;
557         case QEMU_NBD_OPT_DISCARD:
558             if (seen_discard) {
559                 error_report("--discard can only be specified once");
560                 exit(EXIT_FAILURE);
561             }
562             seen_discard = true;
563             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
564                 error_report("Invalid discard mode `%s'", optarg);
565                 exit(EXIT_FAILURE);
566             }
567             break;
568         case QEMU_NBD_OPT_DETECT_ZEROES:
569             detect_zeroes =
570                 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
571                                 optarg,
572                                 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX,
573                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
574                                 &local_err);
575             if (local_err) {
576                 error_reportf_err(local_err,
577                                   "Failed to parse detect_zeroes mode: ");
578                 exit(EXIT_FAILURE);
579             }
580             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
581                 !(flags & BDRV_O_UNMAP)) {
582                 error_report("setting detect-zeroes to unmap is not allowed "
583                              "without setting discard operation to unmap");
584                 exit(EXIT_FAILURE);
585             }
586             break;
587         case 'b':
588             bindto = optarg;
589             break;
590         case 'p':
591             port = optarg;
592             break;
593         case 'o':
594                 dev_offset = strtoll (optarg, &end, 0);
595             if (*end) {
596                 error_report("Invalid offset `%s'", optarg);
597                 exit(EXIT_FAILURE);
598             }
599             if (dev_offset < 0) {
600                 error_report("Offset must be positive `%s'", optarg);
601                 exit(EXIT_FAILURE);
602             }
603             break;
604         case 'l':
605             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
606                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
607                                                   optarg, false);
608                 if (!sn_opts) {
609                     error_report("Failed in parsing snapshot param `%s'",
610                                  optarg);
611                     exit(EXIT_FAILURE);
612                 }
613             } else {
614                 sn_id_or_name = optarg;
615             }
616             /* fall through */
617         case 'r':
618             nbdflags |= NBD_FLAG_READ_ONLY;
619             flags &= ~BDRV_O_RDWR;
620             break;
621         case 'P':
622             partition = strtol(optarg, &end, 0);
623             if (*end) {
624                 error_report("Invalid partition `%s'", optarg);
625                 exit(EXIT_FAILURE);
626             }
627             if (partition < 1 || partition > 8) {
628                 error_report("Invalid partition %d", partition);
629                 exit(EXIT_FAILURE);
630             }
631             break;
632         case 'k':
633             sockpath = optarg;
634             if (sockpath[0] != '/') {
635                 error_report("socket path must be absolute");
636                 exit(EXIT_FAILURE);
637             }
638             break;
639         case 'd':
640             disconnect = true;
641             break;
642         case 'c':
643             device = optarg;
644             break;
645         case 'e':
646             shared = strtol(optarg, &end, 0);
647             if (*end) {
648                 error_report("Invalid shared device number '%s'", optarg);
649                 exit(EXIT_FAILURE);
650             }
651             if (shared < 1) {
652                 error_report("Shared device number must be greater than 0");
653                 exit(EXIT_FAILURE);
654             }
655             break;
656         case 'f':
657             fmt = optarg;
658             break;
659         case 't':
660             persistent = 1;
661             break;
662         case 'x':
663             export_name = optarg;
664             break;
665         case 'v':
666             verbose = 1;
667             break;
668         case 'V':
669             version(argv[0]);
670             exit(0);
671             break;
672         case 'h':
673             usage(argv[0]);
674             exit(0);
675             break;
676         case '?':
677             error_report("Try `%s --help' for more information.", argv[0]);
678             exit(EXIT_FAILURE);
679         case QEMU_NBD_OPT_OBJECT: {
680             QemuOpts *opts;
681             opts = qemu_opts_parse_noisily(&qemu_object_opts,
682                                            optarg, true);
683             if (!opts) {
684                 exit(EXIT_FAILURE);
685             }
686         }   break;
687         case QEMU_NBD_OPT_TLSCREDS:
688             tlscredsid = optarg;
689             break;
690         case QEMU_NBD_OPT_IMAGE_OPTS:
691             imageOpts = true;
692             break;
693         }
694     }
695 
696     if ((argc - optind) != 1) {
697         error_report("Invalid number of arguments");
698         error_printf("Try `%s --help' for more information.\n", argv[0]);
699         exit(EXIT_FAILURE);
700     }
701 
702     if (qemu_opts_foreach(&qemu_object_opts,
703                           user_creatable_add_opts_foreach,
704                           NULL, &local_err)) {
705         error_report_err(local_err);
706         exit(EXIT_FAILURE);
707     }
708 
709     if (tlscredsid) {
710         if (sockpath) {
711             error_report("TLS is only supported with IPv4/IPv6");
712             exit(EXIT_FAILURE);
713         }
714         if (device) {
715             error_report("TLS is not supported with a host device");
716             exit(EXIT_FAILURE);
717         }
718         if (!export_name) {
719             /* Set the default NBD protocol export name, since
720              * we *must* use new style protocol for TLS */
721             export_name = "";
722         }
723         tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);
724         if (local_err) {
725             error_report("Failed to get TLS creds %s",
726                          error_get_pretty(local_err));
727             exit(EXIT_FAILURE);
728         }
729     }
730 
731     if (disconnect) {
732         int nbdfd = open(argv[optind], O_RDWR);
733         if (nbdfd < 0) {
734             error_report("Cannot open %s: %s", argv[optind],
735                          strerror(errno));
736             exit(EXIT_FAILURE);
737         }
738         nbd_disconnect(nbdfd);
739 
740         close(nbdfd);
741 
742         printf("%s disconnected\n", argv[optind]);
743 
744         return 0;
745     }
746 
747     if (device && !verbose) {
748         int stderr_fd[2];
749         pid_t pid;
750         int ret;
751 
752         if (qemu_pipe(stderr_fd) < 0) {
753             error_report("Error setting up communication pipe: %s",
754                          strerror(errno));
755             exit(EXIT_FAILURE);
756         }
757 
758         /* Now daemonize, but keep a communication channel open to
759          * print errors and exit with the proper status code.
760          */
761         pid = fork();
762         if (pid < 0) {
763             error_report("Failed to fork: %s", strerror(errno));
764             exit(EXIT_FAILURE);
765         } else if (pid == 0) {
766             close(stderr_fd[0]);
767             ret = qemu_daemon(1, 0);
768 
769             /* Temporarily redirect stderr to the parent's pipe...  */
770             dup2(stderr_fd[1], STDERR_FILENO);
771             if (ret < 0) {
772                 error_report("Failed to daemonize: %s", strerror(errno));
773                 exit(EXIT_FAILURE);
774             }
775 
776             /* ... close the descriptor we inherited and go on.  */
777             close(stderr_fd[1]);
778         } else {
779             bool errors = false;
780             char *buf;
781 
782             /* In the parent.  Print error messages from the child until
783              * it closes the pipe.
784              */
785             close(stderr_fd[1]);
786             buf = g_malloc(1024);
787             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
788                 errors = true;
789                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
790                 if (ret < 0) {
791                     exit(EXIT_FAILURE);
792                 }
793             }
794             if (ret < 0) {
795                 error_report("Cannot read from daemon: %s",
796                              strerror(errno));
797                 exit(EXIT_FAILURE);
798             }
799 
800             /* Usually the daemon should not print any message.
801              * Exit with zero status in that case.
802              */
803             exit(errors);
804         }
805     }
806 
807     if (device != NULL && sockpath == NULL) {
808         sockpath = g_malloc(128);
809         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
810     }
811 
812     saddr = nbd_build_socket_address(sockpath, bindto, port);
813 
814     if (qemu_init_main_loop(&local_err)) {
815         error_report_err(local_err);
816         exit(EXIT_FAILURE);
817     }
818     bdrv_init();
819     atexit(bdrv_close_all);
820 
821     srcpath = argv[optind];
822     if (imageOpts) {
823         QemuOpts *opts;
824         if (fmt) {
825             error_report("--image-opts and -f are mutually exclusive");
826             exit(EXIT_FAILURE);
827         }
828         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
829         if (!opts) {
830             qemu_opts_reset(&file_opts);
831             exit(EXIT_FAILURE);
832         }
833         options = qemu_opts_to_qdict(opts, NULL);
834         qemu_opts_reset(&file_opts);
835         blk = blk_new_open("hda", NULL, NULL, options, flags, &local_err);
836     } else {
837         if (fmt) {
838             options = qdict_new();
839             qdict_put(options, "driver", qstring_from_str(fmt));
840         }
841         blk = blk_new_open("hda", srcpath, NULL, options, flags, &local_err);
842     }
843 
844     if (!blk) {
845         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
846                           argv[optind]);
847         exit(EXIT_FAILURE);
848     }
849     bs = blk_bs(blk);
850 
851     if (sn_opts) {
852         ret = bdrv_snapshot_load_tmp(bs,
853                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
854                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
855                                      &local_err);
856     } else if (sn_id_or_name) {
857         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
858                                                    &local_err);
859     }
860     if (ret < 0) {
861         error_reportf_err(local_err, "Failed to load snapshot: ");
862         exit(EXIT_FAILURE);
863     }
864 
865     bs->detect_zeroes = detect_zeroes;
866     fd_size = blk_getlength(blk);
867     if (fd_size < 0) {
868         error_report("Failed to determine the image length: %s",
869                      strerror(-fd_size));
870         exit(EXIT_FAILURE);
871     }
872 
873     if (partition != -1) {
874         ret = find_partition(blk, partition, &dev_offset, &fd_size);
875         if (ret < 0) {
876             error_report("Could not find partition %d: %s", partition,
877                          strerror(-ret));
878             exit(EXIT_FAILURE);
879         }
880     }
881 
882     exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed,
883                          &local_err);
884     if (!exp) {
885         error_report_err(local_err);
886         exit(EXIT_FAILURE);
887     }
888     if (export_name) {
889         nbd_export_set_name(exp, export_name);
890         newproto = true;
891     }
892 
893     server_ioc = qio_channel_socket_new();
894     if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) {
895         object_unref(OBJECT(server_ioc));
896         error_report_err(local_err);
897         return 1;
898     }
899 
900     if (device) {
901         int ret;
902 
903         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
904         if (ret != 0) {
905             error_report("Failed to create client thread: %s", strerror(ret));
906             exit(EXIT_FAILURE);
907         }
908     } else {
909         /* Shut up GCC warnings.  */
910         memset(&client_thread, 0, sizeof(client_thread));
911     }
912 
913     nbd_update_server_watch();
914 
915     /* now when the initialization is (almost) complete, chdir("/")
916      * to free any busy filesystems */
917     if (chdir("/") < 0) {
918         error_report("Could not chdir to root directory: %s",
919                      strerror(errno));
920         exit(EXIT_FAILURE);
921     }
922 
923     state = RUNNING;
924     do {
925         main_loop_wait(false);
926         if (state == TERMINATE) {
927             state = TERMINATING;
928             nbd_export_close(exp);
929             nbd_export_put(exp);
930             exp = NULL;
931         }
932     } while (state != TERMINATED);
933 
934     blk_unref(blk);
935     if (sockpath) {
936         unlink(sockpath);
937     }
938 
939     qemu_opts_del(sn_opts);
940 
941     if (device) {
942         void *ret;
943         pthread_join(client_thread, &ret);
944         exit(ret != NULL);
945     } else {
946         exit(EXIT_SUCCESS);
947     }
948 }
949