xref: /openbmc/qemu/qemu-nbd.c (revision bcd82a96)
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 "qapi/error.h"
21 #include "qemu-common.h"
22 #include "qemu/cutils.h"
23 #include "sysemu/block-backend.h"
24 #include "block/block_int.h"
25 #include "block/nbd.h"
26 #include "qemu/main-loop.h"
27 #include "qemu/error-report.h"
28 #include "qemu/config-file.h"
29 #include "block/snapshot.h"
30 #include "qapi/util.h"
31 #include "qapi/qmp/qstring.h"
32 #include "qom/object_interfaces.h"
33 #include "io/channel-socket.h"
34 #include "crypto/init.h"
35 
36 #include <getopt.h>
37 #include <libgen.h>
38 #include <pthread.h>
39 
40 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
41 #define QEMU_NBD_OPT_CACHE         256
42 #define QEMU_NBD_OPT_AIO           257
43 #define QEMU_NBD_OPT_DISCARD       258
44 #define QEMU_NBD_OPT_DETECT_ZEROES 259
45 #define QEMU_NBD_OPT_OBJECT        260
46 #define QEMU_NBD_OPT_TLSCREDS      261
47 #define QEMU_NBD_OPT_IMAGE_OPTS    262
48 
49 static NBDExport *exp;
50 static bool newproto;
51 static int verbose;
52 static char *srcpath;
53 static SocketAddress *saddr;
54 static int persistent = 0;
55 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
56 static int shared = 1;
57 static int nb_fds;
58 static QIOChannelSocket *server_ioc;
59 static int server_watch = -1;
60 static QCryptoTLSCreds *tlscreds;
61 
62 static void usage(const char *name)
63 {
64     (printf) (
65 "Usage: %s [OPTIONS] FILE\n"
66 "QEMU Disk Network Block Device Server\n"
67 "\n"
68 "  -h, --help                display this help and exit\n"
69 "  -V, --version             output version information and exit\n"
70 "\n"
71 "Connection properties:\n"
72 "  -p, --port=PORT           port to listen on (default `%d')\n"
73 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
74 "  -k, --socket=PATH         path to the unix socket\n"
75 "                            (default '"SOCKET_PATH"')\n"
76 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
77 "  -t, --persistent          don't exit on the last connection\n"
78 "  -v, --verbose             display extra debugging information\n"
79 "  -x, --export-name=NAME    expose export by name\n"
80 "\n"
81 "Exposing part of the image:\n"
82 "  -o, --offset=OFFSET       offset into the image\n"
83 "  -P, --partition=NUM       only expose partition NUM\n"
84 "\n"
85 "General purpose options:\n"
86 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
87 "                            passwords and/or encryption keys\n"
88 #ifdef __linux__
89 "Kernel NBD client support:\n"
90 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
91 "  -d, --disconnect          disconnect the specified device\n"
92 "\n"
93 #endif
94 "\n"
95 "Block device options:\n"
96 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
97 "  -r, --read-only           export read-only\n"
98 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
99 "                            file with backing_file=FILE, redirect the write to\n"
100 "                            the temporary one\n"
101 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
102 "                            load an internal snapshot inside FILE and export it\n"
103 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
104 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
105 "                            '[ID_OR_NAME]'\n"
106 "  -n, --nocache             disable host cache\n"
107 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
108 "      --aio=MODE            set AIO mode (native or threads)\n"
109 "      --discard=MODE        set discard mode (ignore, unmap)\n"
110 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
111 "      --image-opts          treat FILE as a full set of image options\n"
112 "\n"
113 "Report bugs to <qemu-devel@nongnu.org>\n"
114     , name, NBD_DEFAULT_PORT, "DEVICE");
115 }
116 
117 static void version(const char *name)
118 {
119     printf(
120 "%s version 0.0.1\n"
121 "Written by Anthony Liguori.\n"
122 "\n"
123 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
124 "This is free software; see the source for copying conditions.  There is NO\n"
125 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
126     , name);
127 }
128 
129 struct partition_record
130 {
131     uint8_t bootable;
132     uint8_t start_head;
133     uint32_t start_cylinder;
134     uint8_t start_sector;
135     uint8_t system;
136     uint8_t end_head;
137     uint8_t end_cylinder;
138     uint8_t end_sector;
139     uint32_t start_sector_abs;
140     uint32_t nb_sectors_abs;
141 };
142 
143 static void read_partition(uint8_t *p, struct partition_record *r)
144 {
145     r->bootable = p[0];
146     r->start_head = p[1];
147     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
148     r->start_sector = p[2] & 0x3f;
149     r->system = p[4];
150     r->end_head = p[5];
151     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
152     r->end_sector = p[6] & 0x3f;
153 
154     r->start_sector_abs = le32_to_cpup((uint32_t *)(p +  8));
155     r->nb_sectors_abs   = le32_to_cpup((uint32_t *)(p + 12));
156 }
157 
158 static int find_partition(BlockBackend *blk, int partition,
159                           off_t *offset, off_t *size)
160 {
161     struct partition_record mbr[4];
162     uint8_t data[512];
163     int i;
164     int ext_partnum = 4;
165     int ret;
166 
167     if ((ret = blk_read(blk, 0, data, 1)) < 0) {
168         error_report("error while reading: %s", strerror(-ret));
169         exit(EXIT_FAILURE);
170     }
171 
172     if (data[510] != 0x55 || data[511] != 0xaa) {
173         return -EINVAL;
174     }
175 
176     for (i = 0; i < 4; i++) {
177         read_partition(&data[446 + 16 * i], &mbr[i]);
178 
179         if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
180             continue;
181         }
182 
183         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
184             struct partition_record ext[4];
185             uint8_t data1[512];
186             int j;
187 
188             if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) {
189                 error_report("error while reading: %s", strerror(-ret));
190                 exit(EXIT_FAILURE);
191             }
192 
193             for (j = 0; j < 4; j++) {
194                 read_partition(&data1[446 + 16 * j], &ext[j]);
195                 if (!ext[j].system || !ext[j].nb_sectors_abs) {
196                     continue;
197                 }
198 
199                 if ((ext_partnum + j + 1) == partition) {
200                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
201                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
202                     return 0;
203                 }
204             }
205             ext_partnum += 4;
206         } else if ((i + 1) == partition) {
207             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
208             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
209             return 0;
210         }
211     }
212 
213     return -ENOENT;
214 }
215 
216 static void termsig_handler(int signum)
217 {
218     atomic_cmpxchg(&state, RUNNING, TERMINATE);
219     qemu_notify_event();
220 }
221 
222 
223 static void *show_parts(void *arg)
224 {
225     char *device = arg;
226     int nbd;
227 
228     /* linux just needs an open() to trigger
229      * the partition table update
230      * but remember to load the module with max_part != 0 :
231      *     modprobe nbd max_part=63
232      */
233     nbd = open(device, O_RDWR);
234     if (nbd >= 0) {
235         close(nbd);
236     }
237     return NULL;
238 }
239 
240 static void *nbd_client_thread(void *arg)
241 {
242     char *device = arg;
243     off_t size;
244     uint32_t nbdflags;
245     QIOChannelSocket *sioc;
246     int fd;
247     int ret;
248     pthread_t show_parts_thread;
249     Error *local_error = NULL;
250 
251     sioc = qio_channel_socket_new();
252     if (qio_channel_socket_connect_sync(sioc,
253                                         saddr,
254                                         &local_error) < 0) {
255         error_report_err(local_error);
256         goto out;
257     }
258 
259     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, &nbdflags,
260                                 NULL, NULL, NULL,
261                                 &size, &local_error);
262     if (ret < 0) {
263         if (local_error) {
264             error_report_err(local_error);
265         }
266         goto out_socket;
267     }
268 
269     fd = open(device, O_RDWR);
270     if (fd < 0) {
271         /* Linux-only, we can use %m in printf.  */
272         error_report("Failed to open %s: %m", device);
273         goto out_socket;
274     }
275 
276     ret = nbd_init(fd, sioc, nbdflags, size);
277     if (ret < 0) {
278         goto out_fd;
279     }
280 
281     /* update partition table */
282     pthread_create(&show_parts_thread, NULL, show_parts, device);
283 
284     if (verbose) {
285         fprintf(stderr, "NBD device %s is now connected to %s\n",
286                 device, srcpath);
287     } else {
288         /* Close stderr so that the qemu-nbd process exits.  */
289         dup2(STDOUT_FILENO, STDERR_FILENO);
290     }
291 
292     ret = nbd_client(fd);
293     if (ret) {
294         goto out_fd;
295     }
296     close(fd);
297     object_unref(OBJECT(sioc));
298     kill(getpid(), SIGTERM);
299     return (void *) EXIT_SUCCESS;
300 
301 out_fd:
302     close(fd);
303 out_socket:
304     object_unref(OBJECT(sioc));
305 out:
306     kill(getpid(), SIGTERM);
307     return (void *) EXIT_FAILURE;
308 }
309 
310 static int nbd_can_accept(void)
311 {
312     return nb_fds < shared;
313 }
314 
315 static void nbd_export_closed(NBDExport *exp)
316 {
317     assert(state == TERMINATING);
318     state = TERMINATED;
319 }
320 
321 static void nbd_update_server_watch(void);
322 
323 static void nbd_client_closed(NBDClient *client)
324 {
325     nb_fds--;
326     if (nb_fds == 0 && !persistent && state == RUNNING) {
327         state = TERMINATE;
328     }
329     nbd_update_server_watch();
330     nbd_client_put(client);
331 }
332 
333 static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque)
334 {
335     QIOChannelSocket *cioc;
336 
337     cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
338                                      NULL);
339     if (!cioc) {
340         return TRUE;
341     }
342 
343     if (state >= TERMINATE) {
344         object_unref(OBJECT(cioc));
345         return TRUE;
346     }
347 
348     nb_fds++;
349     nbd_update_server_watch();
350     nbd_client_new(newproto ? NULL : exp, cioc,
351                    tlscreds, NULL, nbd_client_closed);
352     object_unref(OBJECT(cioc));
353 
354     return TRUE;
355 }
356 
357 static void nbd_update_server_watch(void)
358 {
359     if (nbd_can_accept()) {
360         if (server_watch == -1) {
361             server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc),
362                                                  G_IO_IN,
363                                                  nbd_accept,
364                                                  NULL, NULL);
365         }
366     } else {
367         if (server_watch != -1) {
368             g_source_remove(server_watch);
369             server_watch = -1;
370         }
371     }
372 }
373 
374 
375 static SocketAddress *nbd_build_socket_address(const char *sockpath,
376                                                const char *bindto,
377                                                const char *port)
378 {
379     SocketAddress *saddr;
380 
381     saddr = g_new0(SocketAddress, 1);
382     if (sockpath) {
383         saddr->type = SOCKET_ADDRESS_KIND_UNIX;
384         saddr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
385         saddr->u.q_unix.data->path = g_strdup(sockpath);
386     } else {
387         InetSocketAddress *inet;
388         saddr->type = SOCKET_ADDRESS_KIND_INET;
389         inet = saddr->u.inet.data = g_new0(InetSocketAddress, 1);
390         inet->host = g_strdup(bindto);
391         if (port) {
392             inet->port = g_strdup(port);
393         } else  {
394             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
395         }
396     }
397 
398     return saddr;
399 }
400 
401 
402 static QemuOptsList file_opts = {
403     .name = "file",
404     .implied_opt_name = "file",
405     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
406     .desc = {
407         /* no elements => accept any params */
408         { /* end of list */ }
409     },
410 };
411 
412 static QemuOptsList qemu_object_opts = {
413     .name = "object",
414     .implied_opt_name = "qom-type",
415     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
416     .desc = {
417         { }
418     },
419 };
420 
421 
422 
423 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
424 {
425     Object *obj;
426     QCryptoTLSCreds *creds;
427 
428     obj = object_resolve_path_component(
429         object_get_objects_root(), id);
430     if (!obj) {
431         error_setg(errp, "No TLS credentials with id '%s'",
432                    id);
433         return NULL;
434     }
435     creds = (QCryptoTLSCreds *)
436         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
437     if (!creds) {
438         error_setg(errp, "Object with id '%s' is not TLS credentials",
439                    id);
440         return NULL;
441     }
442 
443     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
444         error_setg(errp,
445                    "Expecting TLS credentials with a server endpoint");
446         return NULL;
447     }
448     object_ref(obj);
449     return creds;
450 }
451 
452 
453 int main(int argc, char **argv)
454 {
455     BlockBackend *blk;
456     BlockDriverState *bs;
457     off_t dev_offset = 0;
458     uint32_t nbdflags = 0;
459     bool disconnect = false;
460     const char *bindto = "0.0.0.0";
461     const char *port = NULL;
462     char *sockpath = NULL;
463     char *device = NULL;
464     off_t fd_size;
465     QemuOpts *sn_opts = NULL;
466     const char *sn_id_or_name = NULL;
467     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:";
468     struct option lopt[] = {
469         { "help", no_argument, NULL, 'h' },
470         { "version", no_argument, NULL, 'V' },
471         { "bind", required_argument, NULL, 'b' },
472         { "port", required_argument, NULL, 'p' },
473         { "socket", required_argument, NULL, 'k' },
474         { "offset", required_argument, NULL, 'o' },
475         { "read-only", no_argument, NULL, 'r' },
476         { "partition", required_argument, NULL, 'P' },
477         { "connect", required_argument, NULL, 'c' },
478         { "disconnect", no_argument, NULL, 'd' },
479         { "snapshot", no_argument, NULL, 's' },
480         { "load-snapshot", required_argument, NULL, 'l' },
481         { "nocache", no_argument, NULL, 'n' },
482         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
483         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
484         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
485         { "detect-zeroes", required_argument, NULL,
486           QEMU_NBD_OPT_DETECT_ZEROES },
487         { "shared", required_argument, NULL, 'e' },
488         { "format", required_argument, NULL, 'f' },
489         { "persistent", no_argument, NULL, 't' },
490         { "verbose", no_argument, NULL, 'v' },
491         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
492         { "export-name", required_argument, NULL, 'x' },
493         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
494         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
495         { NULL, 0, NULL, 0 }
496     };
497     int ch;
498     int opt_ind = 0;
499     char *end;
500     int flags = BDRV_O_RDWR;
501     int partition = -1;
502     int ret = 0;
503     bool seen_cache = false;
504     bool seen_discard = false;
505     bool seen_aio = false;
506     pthread_t client_thread;
507     const char *fmt = NULL;
508     Error *local_err = NULL;
509     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
510     QDict *options = NULL;
511     const char *export_name = NULL;
512     const char *tlscredsid = NULL;
513     bool imageOpts = false;
514     bool writethrough = true;
515 
516     /* The client thread uses SIGTERM to interrupt the server.  A signal
517      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
518      */
519     struct sigaction sa_sigterm;
520     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
521     sa_sigterm.sa_handler = termsig_handler;
522     sigaction(SIGTERM, &sa_sigterm, NULL);
523 
524     if (qcrypto_init(&local_err) < 0) {
525         error_reportf_err(local_err, "cannot initialize crypto: ");
526         exit(1);
527     }
528 
529     module_call_init(MODULE_INIT_QOM);
530     qemu_add_opts(&qemu_object_opts);
531     qemu_init_exec_dir(argv[0]);
532 
533     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
534         switch (ch) {
535         case 's':
536             flags |= BDRV_O_SNAPSHOT;
537             break;
538         case 'n':
539             optarg = (char *) "none";
540             /* fallthrough */
541         case QEMU_NBD_OPT_CACHE:
542             if (seen_cache) {
543                 error_report("-n and --cache can only be specified once");
544                 exit(EXIT_FAILURE);
545             }
546             seen_cache = true;
547             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
548                 error_report("Invalid cache mode `%s'", optarg);
549                 exit(EXIT_FAILURE);
550             }
551             break;
552         case QEMU_NBD_OPT_AIO:
553             if (seen_aio) {
554                 error_report("--aio can only be specified once");
555                 exit(EXIT_FAILURE);
556             }
557             seen_aio = true;
558             if (!strcmp(optarg, "native")) {
559                 flags |= BDRV_O_NATIVE_AIO;
560             } else if (!strcmp(optarg, "threads")) {
561                 /* this is the default */
562             } else {
563                error_report("invalid aio mode `%s'", optarg);
564                exit(EXIT_FAILURE);
565             }
566             break;
567         case QEMU_NBD_OPT_DISCARD:
568             if (seen_discard) {
569                 error_report("--discard can only be specified once");
570                 exit(EXIT_FAILURE);
571             }
572             seen_discard = true;
573             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
574                 error_report("Invalid discard mode `%s'", optarg);
575                 exit(EXIT_FAILURE);
576             }
577             break;
578         case QEMU_NBD_OPT_DETECT_ZEROES:
579             detect_zeroes =
580                 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
581                                 optarg,
582                                 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX,
583                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
584                                 &local_err);
585             if (local_err) {
586                 error_reportf_err(local_err,
587                                   "Failed to parse detect_zeroes mode: ");
588                 exit(EXIT_FAILURE);
589             }
590             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
591                 !(flags & BDRV_O_UNMAP)) {
592                 error_report("setting detect-zeroes to unmap is not allowed "
593                              "without setting discard operation to unmap");
594                 exit(EXIT_FAILURE);
595             }
596             break;
597         case 'b':
598             bindto = optarg;
599             break;
600         case 'p':
601             port = optarg;
602             break;
603         case 'o':
604                 dev_offset = strtoll (optarg, &end, 0);
605             if (*end) {
606                 error_report("Invalid offset `%s'", optarg);
607                 exit(EXIT_FAILURE);
608             }
609             if (dev_offset < 0) {
610                 error_report("Offset must be positive `%s'", optarg);
611                 exit(EXIT_FAILURE);
612             }
613             break;
614         case 'l':
615             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
616                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
617                                                   optarg, false);
618                 if (!sn_opts) {
619                     error_report("Failed in parsing snapshot param `%s'",
620                                  optarg);
621                     exit(EXIT_FAILURE);
622                 }
623             } else {
624                 sn_id_or_name = optarg;
625             }
626             /* fall through */
627         case 'r':
628             nbdflags |= NBD_FLAG_READ_ONLY;
629             flags &= ~BDRV_O_RDWR;
630             break;
631         case 'P':
632             partition = strtol(optarg, &end, 0);
633             if (*end) {
634                 error_report("Invalid partition `%s'", optarg);
635                 exit(EXIT_FAILURE);
636             }
637             if (partition < 1 || partition > 8) {
638                 error_report("Invalid partition %d", partition);
639                 exit(EXIT_FAILURE);
640             }
641             break;
642         case 'k':
643             sockpath = optarg;
644             if (sockpath[0] != '/') {
645                 error_report("socket path must be absolute");
646                 exit(EXIT_FAILURE);
647             }
648             break;
649         case 'd':
650             disconnect = true;
651             break;
652         case 'c':
653             device = optarg;
654             break;
655         case 'e':
656             shared = strtol(optarg, &end, 0);
657             if (*end) {
658                 error_report("Invalid shared device number '%s'", optarg);
659                 exit(EXIT_FAILURE);
660             }
661             if (shared < 1) {
662                 error_report("Shared device number must be greater than 0");
663                 exit(EXIT_FAILURE);
664             }
665             break;
666         case 'f':
667             fmt = optarg;
668             break;
669         case 't':
670             persistent = 1;
671             break;
672         case 'x':
673             export_name = optarg;
674             break;
675         case 'v':
676             verbose = 1;
677             break;
678         case 'V':
679             version(argv[0]);
680             exit(0);
681             break;
682         case 'h':
683             usage(argv[0]);
684             exit(0);
685             break;
686         case '?':
687             error_report("Try `%s --help' for more information.", argv[0]);
688             exit(EXIT_FAILURE);
689         case QEMU_NBD_OPT_OBJECT: {
690             QemuOpts *opts;
691             opts = qemu_opts_parse_noisily(&qemu_object_opts,
692                                            optarg, true);
693             if (!opts) {
694                 exit(EXIT_FAILURE);
695             }
696         }   break;
697         case QEMU_NBD_OPT_TLSCREDS:
698             tlscredsid = optarg;
699             break;
700         case QEMU_NBD_OPT_IMAGE_OPTS:
701             imageOpts = true;
702             break;
703         }
704     }
705 
706     if ((argc - optind) != 1) {
707         error_report("Invalid number of arguments");
708         error_printf("Try `%s --help' for more information.\n", argv[0]);
709         exit(EXIT_FAILURE);
710     }
711 
712     if (qemu_opts_foreach(&qemu_object_opts,
713                           user_creatable_add_opts_foreach,
714                           NULL, &local_err)) {
715         error_report_err(local_err);
716         exit(EXIT_FAILURE);
717     }
718 
719     if (tlscredsid) {
720         if (sockpath) {
721             error_report("TLS is only supported with IPv4/IPv6");
722             exit(EXIT_FAILURE);
723         }
724         if (device) {
725             error_report("TLS is not supported with a host device");
726             exit(EXIT_FAILURE);
727         }
728         if (!export_name) {
729             /* Set the default NBD protocol export name, since
730              * we *must* use new style protocol for TLS */
731             export_name = "";
732         }
733         tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);
734         if (local_err) {
735             error_report("Failed to get TLS creds %s",
736                          error_get_pretty(local_err));
737             exit(EXIT_FAILURE);
738         }
739     }
740 
741     if (disconnect) {
742         int nbdfd = open(argv[optind], O_RDWR);
743         if (nbdfd < 0) {
744             error_report("Cannot open %s: %s", argv[optind],
745                          strerror(errno));
746             exit(EXIT_FAILURE);
747         }
748         nbd_disconnect(nbdfd);
749 
750         close(nbdfd);
751 
752         printf("%s disconnected\n", argv[optind]);
753 
754         return 0;
755     }
756 
757     if (device && !verbose) {
758         int stderr_fd[2];
759         pid_t pid;
760         int ret;
761 
762         if (qemu_pipe(stderr_fd) < 0) {
763             error_report("Error setting up communication pipe: %s",
764                          strerror(errno));
765             exit(EXIT_FAILURE);
766         }
767 
768         /* Now daemonize, but keep a communication channel open to
769          * print errors and exit with the proper status code.
770          */
771         pid = fork();
772         if (pid < 0) {
773             error_report("Failed to fork: %s", strerror(errno));
774             exit(EXIT_FAILURE);
775         } else if (pid == 0) {
776             close(stderr_fd[0]);
777             ret = qemu_daemon(1, 0);
778 
779             /* Temporarily redirect stderr to the parent's pipe...  */
780             dup2(stderr_fd[1], STDERR_FILENO);
781             if (ret < 0) {
782                 error_report("Failed to daemonize: %s", strerror(errno));
783                 exit(EXIT_FAILURE);
784             }
785 
786             /* ... close the descriptor we inherited and go on.  */
787             close(stderr_fd[1]);
788         } else {
789             bool errors = false;
790             char *buf;
791 
792             /* In the parent.  Print error messages from the child until
793              * it closes the pipe.
794              */
795             close(stderr_fd[1]);
796             buf = g_malloc(1024);
797             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
798                 errors = true;
799                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
800                 if (ret < 0) {
801                     exit(EXIT_FAILURE);
802                 }
803             }
804             if (ret < 0) {
805                 error_report("Cannot read from daemon: %s",
806                              strerror(errno));
807                 exit(EXIT_FAILURE);
808             }
809 
810             /* Usually the daemon should not print any message.
811              * Exit with zero status in that case.
812              */
813             exit(errors);
814         }
815     }
816 
817     if (device != NULL && sockpath == NULL) {
818         sockpath = g_malloc(128);
819         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
820     }
821 
822     saddr = nbd_build_socket_address(sockpath, bindto, port);
823 
824     if (qemu_init_main_loop(&local_err)) {
825         error_report_err(local_err);
826         exit(EXIT_FAILURE);
827     }
828     bdrv_init();
829     atexit(bdrv_close_all);
830 
831     srcpath = argv[optind];
832     if (imageOpts) {
833         QemuOpts *opts;
834         if (fmt) {
835             error_report("--image-opts and -f are mutually exclusive");
836             exit(EXIT_FAILURE);
837         }
838         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
839         if (!opts) {
840             qemu_opts_reset(&file_opts);
841             exit(EXIT_FAILURE);
842         }
843         options = qemu_opts_to_qdict(opts, NULL);
844         qemu_opts_reset(&file_opts);
845         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
846     } else {
847         if (fmt) {
848             options = qdict_new();
849             qdict_put(options, "driver", qstring_from_str(fmt));
850         }
851         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
852     }
853 
854     if (!blk) {
855         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
856                           argv[optind]);
857         exit(EXIT_FAILURE);
858     }
859     bs = blk_bs(blk);
860 
861     blk_set_enable_write_cache(blk, !writethrough);
862 
863     if (sn_opts) {
864         ret = bdrv_snapshot_load_tmp(bs,
865                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
866                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
867                                      &local_err);
868     } else if (sn_id_or_name) {
869         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
870                                                    &local_err);
871     }
872     if (ret < 0) {
873         error_reportf_err(local_err, "Failed to load snapshot: ");
874         exit(EXIT_FAILURE);
875     }
876 
877     bs->detect_zeroes = detect_zeroes;
878     fd_size = blk_getlength(blk);
879     if (fd_size < 0) {
880         error_report("Failed to determine the image length: %s",
881                      strerror(-fd_size));
882         exit(EXIT_FAILURE);
883     }
884 
885     if (partition != -1) {
886         ret = find_partition(blk, partition, &dev_offset, &fd_size);
887         if (ret < 0) {
888             error_report("Could not find partition %d: %s", partition,
889                          strerror(-ret));
890             exit(EXIT_FAILURE);
891         }
892     }
893 
894     exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed,
895                          &local_err);
896     if (!exp) {
897         error_report_err(local_err);
898         exit(EXIT_FAILURE);
899     }
900     if (export_name) {
901         nbd_export_set_name(exp, export_name);
902         newproto = true;
903     }
904 
905     server_ioc = qio_channel_socket_new();
906     if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) {
907         object_unref(OBJECT(server_ioc));
908         error_report_err(local_err);
909         return 1;
910     }
911 
912     if (device) {
913         int ret;
914 
915         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
916         if (ret != 0) {
917             error_report("Failed to create client thread: %s", strerror(ret));
918             exit(EXIT_FAILURE);
919         }
920     } else {
921         /* Shut up GCC warnings.  */
922         memset(&client_thread, 0, sizeof(client_thread));
923     }
924 
925     nbd_update_server_watch();
926 
927     /* now when the initialization is (almost) complete, chdir("/")
928      * to free any busy filesystems */
929     if (chdir("/") < 0) {
930         error_report("Could not chdir to root directory: %s",
931                      strerror(errno));
932         exit(EXIT_FAILURE);
933     }
934 
935     state = RUNNING;
936     do {
937         main_loop_wait(false);
938         if (state == TERMINATE) {
939             state = TERMINATING;
940             nbd_export_close(exp);
941             nbd_export_put(exp);
942             exp = NULL;
943         }
944     } while (state != TERMINATED);
945 
946     blk_unref(blk);
947     if (sockpath) {
948         unlink(sockpath);
949     }
950 
951     qemu_opts_del(sn_opts);
952 
953     if (device) {
954         void *ret;
955         pthread_join(client_thread, &ret);
956         exit(ret != NULL);
957     } else {
958         exit(EXIT_SUCCESS);
959     }
960 }
961