xref: /openbmc/qemu/qemu-nbd.c (revision 891f8dcd)
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 "qemu/bswap.h"
30 #include "block/snapshot.h"
31 #include "qapi/util.h"
32 #include "qapi/qmp/qstring.h"
33 #include "qom/object_interfaces.h"
34 #include "io/channel-socket.h"
35 #include "crypto/init.h"
36 
37 #include <getopt.h>
38 #include <libgen.h>
39 #include <pthread.h>
40 
41 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
42 #define QEMU_NBD_OPT_CACHE         256
43 #define QEMU_NBD_OPT_AIO           257
44 #define QEMU_NBD_OPT_DISCARD       258
45 #define QEMU_NBD_OPT_DETECT_ZEROES 259
46 #define QEMU_NBD_OPT_OBJECT        260
47 #define QEMU_NBD_OPT_TLSCREDS      261
48 #define QEMU_NBD_OPT_IMAGE_OPTS    262
49 
50 #define MBR_SIZE 512
51 
52 static NBDExport *exp;
53 static bool newproto;
54 static int verbose;
55 static char *srcpath;
56 static SocketAddress *saddr;
57 static int persistent = 0;
58 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
59 static int shared = 1;
60 static int nb_fds;
61 static QIOChannelSocket *server_ioc;
62 static int server_watch = -1;
63 static QCryptoTLSCreds *tlscreds;
64 
65 static void usage(const char *name)
66 {
67     (printf) (
68 "Usage: %s [OPTIONS] FILE\n"
69 "QEMU Disk Network Block Device Server\n"
70 "\n"
71 "  -h, --help                display this help and exit\n"
72 "  -V, --version             output version information and exit\n"
73 "\n"
74 "Connection properties:\n"
75 "  -p, --port=PORT           port to listen on (default `%d')\n"
76 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
77 "  -k, --socket=PATH         path to the unix socket\n"
78 "                            (default '"SOCKET_PATH"')\n"
79 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
80 "  -t, --persistent          don't exit on the last connection\n"
81 "  -v, --verbose             display extra debugging information\n"
82 "  -x, --export-name=NAME    expose export by name\n"
83 "\n"
84 "Exposing part of the image:\n"
85 "  -o, --offset=OFFSET       offset into the image\n"
86 "  -P, --partition=NUM       only expose partition NUM\n"
87 "\n"
88 "General purpose options:\n"
89 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
90 "                            passwords and/or encryption keys\n"
91 #ifdef __linux__
92 "Kernel NBD client support:\n"
93 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
94 "  -d, --disconnect          disconnect the specified device\n"
95 "\n"
96 #endif
97 "\n"
98 "Block device options:\n"
99 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
100 "  -r, --read-only           export read-only\n"
101 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
102 "                            file with backing_file=FILE, redirect the write to\n"
103 "                            the temporary one\n"
104 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
105 "                            load an internal snapshot inside FILE and export it\n"
106 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
107 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
108 "                            '[ID_OR_NAME]'\n"
109 "  -n, --nocache             disable host cache\n"
110 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
111 "      --aio=MODE            set AIO mode (native or threads)\n"
112 "      --discard=MODE        set discard mode (ignore, unmap)\n"
113 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
114 "      --image-opts          treat FILE as a full set of image options\n"
115 "\n"
116 "Report bugs to <qemu-devel@nongnu.org>\n"
117     , name, NBD_DEFAULT_PORT, "DEVICE");
118 }
119 
120 static void version(const char *name)
121 {
122     printf(
123 "%s version 0.0.1\n"
124 "Written by Anthony Liguori.\n"
125 "\n"
126 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
127 "This is free software; see the source for copying conditions.  There is NO\n"
128 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
129     , name);
130 }
131 
132 struct partition_record
133 {
134     uint8_t bootable;
135     uint8_t start_head;
136     uint32_t start_cylinder;
137     uint8_t start_sector;
138     uint8_t system;
139     uint8_t end_head;
140     uint8_t end_cylinder;
141     uint8_t end_sector;
142     uint32_t start_sector_abs;
143     uint32_t nb_sectors_abs;
144 };
145 
146 static void read_partition(uint8_t *p, struct partition_record *r)
147 {
148     r->bootable = p[0];
149     r->start_head = p[1];
150     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
151     r->start_sector = p[2] & 0x3f;
152     r->system = p[4];
153     r->end_head = p[5];
154     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
155     r->end_sector = p[6] & 0x3f;
156 
157     r->start_sector_abs = le32_to_cpup((uint32_t *)(p +  8));
158     r->nb_sectors_abs   = le32_to_cpup((uint32_t *)(p + 12));
159 }
160 
161 static int find_partition(BlockBackend *blk, int partition,
162                           off_t *offset, off_t *size)
163 {
164     struct partition_record mbr[4];
165     uint8_t data[MBR_SIZE];
166     int i;
167     int ext_partnum = 4;
168     int ret;
169 
170     ret = blk_pread(blk, 0, data, sizeof(data));
171     if (ret < 0) {
172         error_report("error while reading: %s", strerror(-ret));
173         exit(EXIT_FAILURE);
174     }
175 
176     if (data[510] != 0x55 || data[511] != 0xaa) {
177         return -EINVAL;
178     }
179 
180     for (i = 0; i < 4; i++) {
181         read_partition(&data[446 + 16 * i], &mbr[i]);
182 
183         if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
184             continue;
185         }
186 
187         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
188             struct partition_record ext[4];
189             uint8_t data1[MBR_SIZE];
190             int j;
191 
192             ret = blk_pread(blk, mbr[i].start_sector_abs * MBR_SIZE,
193                             data1, sizeof(data1));
194             if (ret < 0) {
195                 error_report("error while reading: %s", strerror(-ret));
196                 exit(EXIT_FAILURE);
197             }
198 
199             for (j = 0; j < 4; j++) {
200                 read_partition(&data1[446 + 16 * j], &ext[j]);
201                 if (!ext[j].system || !ext[j].nb_sectors_abs) {
202                     continue;
203                 }
204 
205                 if ((ext_partnum + j + 1) == partition) {
206                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
207                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
208                     return 0;
209                 }
210             }
211             ext_partnum += 4;
212         } else if ((i + 1) == partition) {
213             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
214             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
215             return 0;
216         }
217     }
218 
219     return -ENOENT;
220 }
221 
222 static void termsig_handler(int signum)
223 {
224     atomic_cmpxchg(&state, RUNNING, TERMINATE);
225     qemu_notify_event();
226 }
227 
228 
229 static void *show_parts(void *arg)
230 {
231     char *device = arg;
232     int nbd;
233 
234     /* linux just needs an open() to trigger
235      * the partition table update
236      * but remember to load the module with max_part != 0 :
237      *     modprobe nbd max_part=63
238      */
239     nbd = open(device, O_RDWR);
240     if (nbd >= 0) {
241         close(nbd);
242     }
243     return NULL;
244 }
245 
246 static void *nbd_client_thread(void *arg)
247 {
248     char *device = arg;
249     off_t size;
250     uint32_t nbdflags;
251     QIOChannelSocket *sioc;
252     int fd;
253     int ret;
254     pthread_t show_parts_thread;
255     Error *local_error = NULL;
256 
257     sioc = qio_channel_socket_new();
258     if (qio_channel_socket_connect_sync(sioc,
259                                         saddr,
260                                         &local_error) < 0) {
261         error_report_err(local_error);
262         goto out;
263     }
264 
265     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, &nbdflags,
266                                 NULL, NULL, NULL,
267                                 &size, &local_error);
268     if (ret < 0) {
269         if (local_error) {
270             error_report_err(local_error);
271         }
272         goto out_socket;
273     }
274 
275     fd = open(device, O_RDWR);
276     if (fd < 0) {
277         /* Linux-only, we can use %m in printf.  */
278         error_report("Failed to open %s: %m", device);
279         goto out_socket;
280     }
281 
282     ret = nbd_init(fd, sioc, nbdflags, size);
283     if (ret < 0) {
284         goto out_fd;
285     }
286 
287     /* update partition table */
288     pthread_create(&show_parts_thread, NULL, show_parts, device);
289 
290     if (verbose) {
291         fprintf(stderr, "NBD device %s is now connected to %s\n",
292                 device, srcpath);
293     } else {
294         /* Close stderr so that the qemu-nbd process exits.  */
295         dup2(STDOUT_FILENO, STDERR_FILENO);
296     }
297 
298     ret = nbd_client(fd);
299     if (ret) {
300         goto out_fd;
301     }
302     close(fd);
303     object_unref(OBJECT(sioc));
304     kill(getpid(), SIGTERM);
305     return (void *) EXIT_SUCCESS;
306 
307 out_fd:
308     close(fd);
309 out_socket:
310     object_unref(OBJECT(sioc));
311 out:
312     kill(getpid(), SIGTERM);
313     return (void *) EXIT_FAILURE;
314 }
315 
316 static int nbd_can_accept(void)
317 {
318     return nb_fds < shared;
319 }
320 
321 static void nbd_export_closed(NBDExport *exp)
322 {
323     assert(state == TERMINATING);
324     state = TERMINATED;
325 }
326 
327 static void nbd_update_server_watch(void);
328 
329 static void nbd_client_closed(NBDClient *client)
330 {
331     nb_fds--;
332     if (nb_fds == 0 && !persistent && state == RUNNING) {
333         state = TERMINATE;
334     }
335     nbd_update_server_watch();
336     nbd_client_put(client);
337 }
338 
339 static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque)
340 {
341     QIOChannelSocket *cioc;
342 
343     cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
344                                      NULL);
345     if (!cioc) {
346         return TRUE;
347     }
348 
349     if (state >= TERMINATE) {
350         object_unref(OBJECT(cioc));
351         return TRUE;
352     }
353 
354     nb_fds++;
355     nbd_update_server_watch();
356     nbd_client_new(newproto ? NULL : exp, cioc,
357                    tlscreds, NULL, nbd_client_closed);
358     object_unref(OBJECT(cioc));
359 
360     return TRUE;
361 }
362 
363 static void nbd_update_server_watch(void)
364 {
365     if (nbd_can_accept()) {
366         if (server_watch == -1) {
367             server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc),
368                                                  G_IO_IN,
369                                                  nbd_accept,
370                                                  NULL, NULL);
371         }
372     } else {
373         if (server_watch != -1) {
374             g_source_remove(server_watch);
375             server_watch = -1;
376         }
377     }
378 }
379 
380 
381 static SocketAddress *nbd_build_socket_address(const char *sockpath,
382                                                const char *bindto,
383                                                const char *port)
384 {
385     SocketAddress *saddr;
386 
387     saddr = g_new0(SocketAddress, 1);
388     if (sockpath) {
389         saddr->type = SOCKET_ADDRESS_KIND_UNIX;
390         saddr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
391         saddr->u.q_unix.data->path = g_strdup(sockpath);
392     } else {
393         InetSocketAddress *inet;
394         saddr->type = SOCKET_ADDRESS_KIND_INET;
395         inet = saddr->u.inet.data = g_new0(InetSocketAddress, 1);
396         inet->host = g_strdup(bindto);
397         if (port) {
398             inet->port = g_strdup(port);
399         } else  {
400             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
401         }
402     }
403 
404     return saddr;
405 }
406 
407 
408 static QemuOptsList file_opts = {
409     .name = "file",
410     .implied_opt_name = "file",
411     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
412     .desc = {
413         /* no elements => accept any params */
414         { /* end of list */ }
415     },
416 };
417 
418 static QemuOptsList qemu_object_opts = {
419     .name = "object",
420     .implied_opt_name = "qom-type",
421     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
422     .desc = {
423         { }
424     },
425 };
426 
427 
428 
429 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
430 {
431     Object *obj;
432     QCryptoTLSCreds *creds;
433 
434     obj = object_resolve_path_component(
435         object_get_objects_root(), id);
436     if (!obj) {
437         error_setg(errp, "No TLS credentials with id '%s'",
438                    id);
439         return NULL;
440     }
441     creds = (QCryptoTLSCreds *)
442         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
443     if (!creds) {
444         error_setg(errp, "Object with id '%s' is not TLS credentials",
445                    id);
446         return NULL;
447     }
448 
449     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
450         error_setg(errp,
451                    "Expecting TLS credentials with a server endpoint");
452         return NULL;
453     }
454     object_ref(obj);
455     return creds;
456 }
457 
458 
459 int main(int argc, char **argv)
460 {
461     BlockBackend *blk;
462     BlockDriverState *bs;
463     off_t dev_offset = 0;
464     uint32_t nbdflags = 0;
465     bool disconnect = false;
466     const char *bindto = "0.0.0.0";
467     const char *port = NULL;
468     char *sockpath = NULL;
469     char *device = NULL;
470     off_t fd_size;
471     QemuOpts *sn_opts = NULL;
472     const char *sn_id_or_name = NULL;
473     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:";
474     struct option lopt[] = {
475         { "help", no_argument, NULL, 'h' },
476         { "version", no_argument, NULL, 'V' },
477         { "bind", required_argument, NULL, 'b' },
478         { "port", required_argument, NULL, 'p' },
479         { "socket", required_argument, NULL, 'k' },
480         { "offset", required_argument, NULL, 'o' },
481         { "read-only", no_argument, NULL, 'r' },
482         { "partition", required_argument, NULL, 'P' },
483         { "connect", required_argument, NULL, 'c' },
484         { "disconnect", no_argument, NULL, 'd' },
485         { "snapshot", no_argument, NULL, 's' },
486         { "load-snapshot", required_argument, NULL, 'l' },
487         { "nocache", no_argument, NULL, 'n' },
488         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
489         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
490         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
491         { "detect-zeroes", required_argument, NULL,
492           QEMU_NBD_OPT_DETECT_ZEROES },
493         { "shared", required_argument, NULL, 'e' },
494         { "format", required_argument, NULL, 'f' },
495         { "persistent", no_argument, NULL, 't' },
496         { "verbose", no_argument, NULL, 'v' },
497         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
498         { "export-name", required_argument, NULL, 'x' },
499         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
500         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
501         { NULL, 0, NULL, 0 }
502     };
503     int ch;
504     int opt_ind = 0;
505     char *end;
506     int flags = BDRV_O_RDWR;
507     int partition = -1;
508     int ret = 0;
509     bool seen_cache = false;
510     bool seen_discard = false;
511     bool seen_aio = false;
512     pthread_t client_thread;
513     const char *fmt = NULL;
514     Error *local_err = NULL;
515     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
516     QDict *options = NULL;
517     const char *export_name = NULL;
518     const char *tlscredsid = NULL;
519     bool imageOpts = false;
520     bool writethrough = true;
521 
522     /* The client thread uses SIGTERM to interrupt the server.  A signal
523      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
524      */
525     struct sigaction sa_sigterm;
526     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
527     sa_sigterm.sa_handler = termsig_handler;
528     sigaction(SIGTERM, &sa_sigterm, NULL);
529 
530     qcrypto_init(&error_fatal);
531 
532     module_call_init(MODULE_INIT_QOM);
533     qemu_add_opts(&qemu_object_opts);
534     qemu_init_exec_dir(argv[0]);
535 
536     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
537         switch (ch) {
538         case 's':
539             flags |= BDRV_O_SNAPSHOT;
540             break;
541         case 'n':
542             optarg = (char *) "none";
543             /* fallthrough */
544         case QEMU_NBD_OPT_CACHE:
545             if (seen_cache) {
546                 error_report("-n and --cache can only be specified once");
547                 exit(EXIT_FAILURE);
548             }
549             seen_cache = true;
550             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
551                 error_report("Invalid cache mode `%s'", optarg);
552                 exit(EXIT_FAILURE);
553             }
554             break;
555         case QEMU_NBD_OPT_AIO:
556             if (seen_aio) {
557                 error_report("--aio can only be specified once");
558                 exit(EXIT_FAILURE);
559             }
560             seen_aio = true;
561             if (!strcmp(optarg, "native")) {
562                 flags |= BDRV_O_NATIVE_AIO;
563             } else if (!strcmp(optarg, "threads")) {
564                 /* this is the default */
565             } else {
566                error_report("invalid aio mode `%s'", optarg);
567                exit(EXIT_FAILURE);
568             }
569             break;
570         case QEMU_NBD_OPT_DISCARD:
571             if (seen_discard) {
572                 error_report("--discard can only be specified once");
573                 exit(EXIT_FAILURE);
574             }
575             seen_discard = true;
576             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
577                 error_report("Invalid discard mode `%s'", optarg);
578                 exit(EXIT_FAILURE);
579             }
580             break;
581         case QEMU_NBD_OPT_DETECT_ZEROES:
582             detect_zeroes =
583                 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
584                                 optarg,
585                                 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX,
586                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
587                                 &local_err);
588             if (local_err) {
589                 error_reportf_err(local_err,
590                                   "Failed to parse detect_zeroes mode: ");
591                 exit(EXIT_FAILURE);
592             }
593             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
594                 !(flags & BDRV_O_UNMAP)) {
595                 error_report("setting detect-zeroes to unmap is not allowed "
596                              "without setting discard operation to unmap");
597                 exit(EXIT_FAILURE);
598             }
599             break;
600         case 'b':
601             bindto = optarg;
602             break;
603         case 'p':
604             port = optarg;
605             break;
606         case 'o':
607                 dev_offset = strtoll (optarg, &end, 0);
608             if (*end) {
609                 error_report("Invalid offset `%s'", optarg);
610                 exit(EXIT_FAILURE);
611             }
612             if (dev_offset < 0) {
613                 error_report("Offset must be positive `%s'", optarg);
614                 exit(EXIT_FAILURE);
615             }
616             break;
617         case 'l':
618             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
619                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
620                                                   optarg, false);
621                 if (!sn_opts) {
622                     error_report("Failed in parsing snapshot param `%s'",
623                                  optarg);
624                     exit(EXIT_FAILURE);
625                 }
626             } else {
627                 sn_id_or_name = optarg;
628             }
629             /* fall through */
630         case 'r':
631             nbdflags |= NBD_FLAG_READ_ONLY;
632             flags &= ~BDRV_O_RDWR;
633             break;
634         case 'P':
635             partition = strtol(optarg, &end, 0);
636             if (*end) {
637                 error_report("Invalid partition `%s'", optarg);
638                 exit(EXIT_FAILURE);
639             }
640             if (partition < 1 || partition > 8) {
641                 error_report("Invalid partition %d", partition);
642                 exit(EXIT_FAILURE);
643             }
644             break;
645         case 'k':
646             sockpath = optarg;
647             if (sockpath[0] != '/') {
648                 error_report("socket path must be absolute");
649                 exit(EXIT_FAILURE);
650             }
651             break;
652         case 'd':
653             disconnect = true;
654             break;
655         case 'c':
656             device = optarg;
657             break;
658         case 'e':
659             shared = strtol(optarg, &end, 0);
660             if (*end) {
661                 error_report("Invalid shared device number '%s'", optarg);
662                 exit(EXIT_FAILURE);
663             }
664             if (shared < 1) {
665                 error_report("Shared device number must be greater than 0");
666                 exit(EXIT_FAILURE);
667             }
668             break;
669         case 'f':
670             fmt = optarg;
671             break;
672         case 't':
673             persistent = 1;
674             break;
675         case 'x':
676             export_name = optarg;
677             break;
678         case 'v':
679             verbose = 1;
680             break;
681         case 'V':
682             version(argv[0]);
683             exit(0);
684             break;
685         case 'h':
686             usage(argv[0]);
687             exit(0);
688             break;
689         case '?':
690             error_report("Try `%s --help' for more information.", argv[0]);
691             exit(EXIT_FAILURE);
692         case QEMU_NBD_OPT_OBJECT: {
693             QemuOpts *opts;
694             opts = qemu_opts_parse_noisily(&qemu_object_opts,
695                                            optarg, true);
696             if (!opts) {
697                 exit(EXIT_FAILURE);
698             }
699         }   break;
700         case QEMU_NBD_OPT_TLSCREDS:
701             tlscredsid = optarg;
702             break;
703         case QEMU_NBD_OPT_IMAGE_OPTS:
704             imageOpts = true;
705             break;
706         }
707     }
708 
709     if ((argc - optind) != 1) {
710         error_report("Invalid number of arguments");
711         error_printf("Try `%s --help' for more information.\n", argv[0]);
712         exit(EXIT_FAILURE);
713     }
714 
715     if (qemu_opts_foreach(&qemu_object_opts,
716                           user_creatable_add_opts_foreach,
717                           NULL, NULL)) {
718         exit(EXIT_FAILURE);
719     }
720 
721     if (tlscredsid) {
722         if (sockpath) {
723             error_report("TLS is only supported with IPv4/IPv6");
724             exit(EXIT_FAILURE);
725         }
726         if (device) {
727             error_report("TLS is not supported with a host device");
728             exit(EXIT_FAILURE);
729         }
730         if (!export_name) {
731             /* Set the default NBD protocol export name, since
732              * we *must* use new style protocol for TLS */
733             export_name = "";
734         }
735         tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);
736         if (local_err) {
737             error_report("Failed to get TLS creds %s",
738                          error_get_pretty(local_err));
739             exit(EXIT_FAILURE);
740         }
741     }
742 
743     if (disconnect) {
744         int nbdfd = open(argv[optind], O_RDWR);
745         if (nbdfd < 0) {
746             error_report("Cannot open %s: %s", argv[optind],
747                          strerror(errno));
748             exit(EXIT_FAILURE);
749         }
750         nbd_disconnect(nbdfd);
751 
752         close(nbdfd);
753 
754         printf("%s disconnected\n", argv[optind]);
755 
756         return 0;
757     }
758 
759     if (device && !verbose) {
760         int stderr_fd[2];
761         pid_t pid;
762         int ret;
763 
764         if (qemu_pipe(stderr_fd) < 0) {
765             error_report("Error setting up communication pipe: %s",
766                          strerror(errno));
767             exit(EXIT_FAILURE);
768         }
769 
770         /* Now daemonize, but keep a communication channel open to
771          * print errors and exit with the proper status code.
772          */
773         pid = fork();
774         if (pid < 0) {
775             error_report("Failed to fork: %s", strerror(errno));
776             exit(EXIT_FAILURE);
777         } else if (pid == 0) {
778             close(stderr_fd[0]);
779             ret = qemu_daemon(1, 0);
780 
781             /* Temporarily redirect stderr to the parent's pipe...  */
782             dup2(stderr_fd[1], STDERR_FILENO);
783             if (ret < 0) {
784                 error_report("Failed to daemonize: %s", strerror(errno));
785                 exit(EXIT_FAILURE);
786             }
787 
788             /* ... close the descriptor we inherited and go on.  */
789             close(stderr_fd[1]);
790         } else {
791             bool errors = false;
792             char *buf;
793 
794             /* In the parent.  Print error messages from the child until
795              * it closes the pipe.
796              */
797             close(stderr_fd[1]);
798             buf = g_malloc(1024);
799             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
800                 errors = true;
801                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
802                 if (ret < 0) {
803                     exit(EXIT_FAILURE);
804                 }
805             }
806             if (ret < 0) {
807                 error_report("Cannot read from daemon: %s",
808                              strerror(errno));
809                 exit(EXIT_FAILURE);
810             }
811 
812             /* Usually the daemon should not print any message.
813              * Exit with zero status in that case.
814              */
815             exit(errors);
816         }
817     }
818 
819     if (device != NULL && sockpath == NULL) {
820         sockpath = g_malloc(128);
821         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
822     }
823 
824     saddr = nbd_build_socket_address(sockpath, bindto, port);
825 
826     if (qemu_init_main_loop(&local_err)) {
827         error_report_err(local_err);
828         exit(EXIT_FAILURE);
829     }
830     bdrv_init();
831     atexit(bdrv_close_all);
832 
833     srcpath = argv[optind];
834     if (imageOpts) {
835         QemuOpts *opts;
836         if (fmt) {
837             error_report("--image-opts and -f are mutually exclusive");
838             exit(EXIT_FAILURE);
839         }
840         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
841         if (!opts) {
842             qemu_opts_reset(&file_opts);
843             exit(EXIT_FAILURE);
844         }
845         options = qemu_opts_to_qdict(opts, NULL);
846         qemu_opts_reset(&file_opts);
847         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
848     } else {
849         if (fmt) {
850             options = qdict_new();
851             qdict_put(options, "driver", qstring_from_str(fmt));
852         }
853         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
854     }
855 
856     if (!blk) {
857         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
858                           argv[optind]);
859         exit(EXIT_FAILURE);
860     }
861     bs = blk_bs(blk);
862 
863     blk_set_enable_write_cache(blk, !writethrough);
864 
865     if (sn_opts) {
866         ret = bdrv_snapshot_load_tmp(bs,
867                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
868                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
869                                      &local_err);
870     } else if (sn_id_or_name) {
871         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
872                                                    &local_err);
873     }
874     if (ret < 0) {
875         error_reportf_err(local_err, "Failed to load snapshot: ");
876         exit(EXIT_FAILURE);
877     }
878 
879     bs->detect_zeroes = detect_zeroes;
880     fd_size = blk_getlength(blk);
881     if (fd_size < 0) {
882         error_report("Failed to determine the image length: %s",
883                      strerror(-fd_size));
884         exit(EXIT_FAILURE);
885     }
886 
887     if (partition != -1) {
888         ret = find_partition(blk, partition, &dev_offset, &fd_size);
889         if (ret < 0) {
890             error_report("Could not find partition %d: %s", partition,
891                          strerror(-ret));
892             exit(EXIT_FAILURE);
893         }
894     }
895 
896     exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed,
897                          &local_err);
898     if (!exp) {
899         error_report_err(local_err);
900         exit(EXIT_FAILURE);
901     }
902     if (export_name) {
903         nbd_export_set_name(exp, export_name);
904         newproto = true;
905     }
906 
907     server_ioc = qio_channel_socket_new();
908     if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) {
909         object_unref(OBJECT(server_ioc));
910         error_report_err(local_err);
911         return 1;
912     }
913 
914     if (device) {
915         int ret;
916 
917         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
918         if (ret != 0) {
919             error_report("Failed to create client thread: %s", strerror(ret));
920             exit(EXIT_FAILURE);
921         }
922     } else {
923         /* Shut up GCC warnings.  */
924         memset(&client_thread, 0, sizeof(client_thread));
925     }
926 
927     nbd_update_server_watch();
928 
929     /* now when the initialization is (almost) complete, chdir("/")
930      * to free any busy filesystems */
931     if (chdir("/") < 0) {
932         error_report("Could not chdir to root directory: %s",
933                      strerror(errno));
934         exit(EXIT_FAILURE);
935     }
936 
937     state = RUNNING;
938     do {
939         main_loop_wait(false);
940         if (state == TERMINATE) {
941             state = TERMINATING;
942             nbd_export_close(exp);
943             nbd_export_put(exp);
944             exp = NULL;
945         }
946     } while (state != TERMINATED);
947 
948     blk_unref(blk);
949     if (sockpath) {
950         unlink(sockpath);
951     }
952 
953     qemu_opts_del(sn_opts);
954 
955     if (device) {
956         void *ret;
957         pthread_join(client_thread, &ret);
958         exit(ret != NULL);
959     } else {
960         exit(EXIT_SUCCESS);
961     }
962 }
963