xref: /openbmc/qemu/qemu-nbd.c (revision b917da4c)
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 <libgen.h>
35 #include <pthread.h>
36 
37 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
38 #define QEMU_NBD_OPT_CACHE         256
39 #define QEMU_NBD_OPT_AIO           257
40 #define QEMU_NBD_OPT_DISCARD       258
41 #define QEMU_NBD_OPT_DETECT_ZEROES 259
42 #define QEMU_NBD_OPT_OBJECT        260
43 #define QEMU_NBD_OPT_TLSCREDS      261
44 #define QEMU_NBD_OPT_IMAGE_OPTS    262
45 
46 static NBDExport *exp;
47 static bool newproto;
48 static int verbose;
49 static char *srcpath;
50 static SocketAddress *saddr;
51 static int persistent = 0;
52 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
53 static int shared = 1;
54 static int nb_fds;
55 static QIOChannelSocket *server_ioc;
56 static int server_watch = -1;
57 static QCryptoTLSCreds *tlscreds;
58 
59 static void usage(const char *name)
60 {
61     (printf) (
62 "Usage: %s [OPTIONS] FILE\n"
63 "QEMU Disk Network Block Device Server\n"
64 "\n"
65 "  -h, --help                display this help and exit\n"
66 "  -V, --version             output version information and exit\n"
67 "\n"
68 "Connection properties:\n"
69 "  -p, --port=PORT           port to listen on (default `%d')\n"
70 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
71 "  -k, --socket=PATH         path to the unix socket\n"
72 "                            (default '"SOCKET_PATH"')\n"
73 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
74 "  -t, --persistent          don't exit on the last connection\n"
75 "  -v, --verbose             display extra debugging information\n"
76 "\n"
77 "Exposing part of the image:\n"
78 "  -o, --offset=OFFSET       offset into the image\n"
79 "  -P, --partition=NUM       only expose partition NUM\n"
80 "\n"
81 "General purpose options:\n"
82 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
83 "                            passwords and/or encryption keys\n"
84 #ifdef __linux__
85 "Kernel NBD client support:\n"
86 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
87 "  -d, --disconnect          disconnect the specified device\n"
88 "\n"
89 #endif
90 "\n"
91 "Block device options:\n"
92 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
93 "  -r, --read-only           export read-only\n"
94 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
95 "                            file with backing_file=FILE, redirect the write to\n"
96 "                            the temporary one\n"
97 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
98 "                            load an internal snapshot inside FILE and export it\n"
99 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
100 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
101 "                            '[ID_OR_NAME]'\n"
102 "  -n, --nocache             disable host cache\n"
103 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
104 "      --aio=MODE            set AIO mode (native or threads)\n"
105 "      --discard=MODE        set discard mode (ignore, unmap)\n"
106 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
107 "      --image-opts          treat FILE as a full set of image options\n"
108 "\n"
109 "Report bugs to <qemu-devel@nongnu.org>\n"
110     , name, NBD_DEFAULT_PORT, "DEVICE");
111 }
112 
113 static void version(const char *name)
114 {
115     printf(
116 "%s version 0.0.1\n"
117 "Written by Anthony Liguori.\n"
118 "\n"
119 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
120 "This is free software; see the source for copying conditions.  There is NO\n"
121 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
122     , name);
123 }
124 
125 struct partition_record
126 {
127     uint8_t bootable;
128     uint8_t start_head;
129     uint32_t start_cylinder;
130     uint8_t start_sector;
131     uint8_t system;
132     uint8_t end_head;
133     uint8_t end_cylinder;
134     uint8_t end_sector;
135     uint32_t start_sector_abs;
136     uint32_t nb_sectors_abs;
137 };
138 
139 static void read_partition(uint8_t *p, struct partition_record *r)
140 {
141     r->bootable = p[0];
142     r->start_head = p[1];
143     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
144     r->start_sector = p[2] & 0x3f;
145     r->system = p[4];
146     r->end_head = p[5];
147     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
148     r->end_sector = p[6] & 0x3f;
149 
150     r->start_sector_abs = le32_to_cpup((uint32_t *)(p +  8));
151     r->nb_sectors_abs   = le32_to_cpup((uint32_t *)(p + 12));
152 }
153 
154 static int find_partition(BlockBackend *blk, int partition,
155                           off_t *offset, off_t *size)
156 {
157     struct partition_record mbr[4];
158     uint8_t data[512];
159     int i;
160     int ext_partnum = 4;
161     int ret;
162 
163     if ((ret = blk_read(blk, 0, data, 1)) < 0) {
164         error_report("error while reading: %s", strerror(-ret));
165         exit(EXIT_FAILURE);
166     }
167 
168     if (data[510] != 0x55 || data[511] != 0xaa) {
169         return -EINVAL;
170     }
171 
172     for (i = 0; i < 4; i++) {
173         read_partition(&data[446 + 16 * i], &mbr[i]);
174 
175         if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
176             continue;
177         }
178 
179         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
180             struct partition_record ext[4];
181             uint8_t data1[512];
182             int j;
183 
184             if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) {
185                 error_report("error while reading: %s", strerror(-ret));
186                 exit(EXIT_FAILURE);
187             }
188 
189             for (j = 0; j < 4; j++) {
190                 read_partition(&data1[446 + 16 * j], &ext[j]);
191                 if (!ext[j].system || !ext[j].nb_sectors_abs) {
192                     continue;
193                 }
194 
195                 if ((ext_partnum + j + 1) == partition) {
196                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
197                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
198                     return 0;
199                 }
200             }
201             ext_partnum += 4;
202         } else if ((i + 1) == partition) {
203             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
204             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
205             return 0;
206         }
207     }
208 
209     return -ENOENT;
210 }
211 
212 static void termsig_handler(int signum)
213 {
214     state = TERMINATE;
215     qemu_notify_event();
216 }
217 
218 
219 static void *show_parts(void *arg)
220 {
221     char *device = arg;
222     int nbd;
223 
224     /* linux just needs an open() to trigger
225      * the partition table update
226      * but remember to load the module with max_part != 0 :
227      *     modprobe nbd max_part=63
228      */
229     nbd = open(device, O_RDWR);
230     if (nbd >= 0) {
231         close(nbd);
232     }
233     return NULL;
234 }
235 
236 static void *nbd_client_thread(void *arg)
237 {
238     char *device = arg;
239     off_t size;
240     uint32_t nbdflags;
241     QIOChannelSocket *sioc;
242     int fd;
243     int ret;
244     pthread_t show_parts_thread;
245     Error *local_error = NULL;
246 
247     sioc = qio_channel_socket_new();
248     if (qio_channel_socket_connect_sync(sioc,
249                                         saddr,
250                                         &local_error) < 0) {
251         error_report_err(local_error);
252         goto out;
253     }
254 
255     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, &nbdflags,
256                                 NULL, NULL, NULL,
257                                 &size, &local_error);
258     if (ret < 0) {
259         if (local_error) {
260             error_report_err(local_error);
261         }
262         goto out_socket;
263     }
264 
265     fd = open(device, O_RDWR);
266     if (fd < 0) {
267         /* Linux-only, we can use %m in printf.  */
268         error_report("Failed to open %s: %m", device);
269         goto out_socket;
270     }
271 
272     ret = nbd_init(fd, sioc, nbdflags, size);
273     if (ret < 0) {
274         goto out_fd;
275     }
276 
277     /* update partition table */
278     pthread_create(&show_parts_thread, NULL, show_parts, device);
279 
280     if (verbose) {
281         fprintf(stderr, "NBD device %s is now connected to %s\n",
282                 device, srcpath);
283     } else {
284         /* Close stderr so that the qemu-nbd process exits.  */
285         dup2(STDOUT_FILENO, STDERR_FILENO);
286     }
287 
288     ret = nbd_client(fd);
289     if (ret) {
290         goto out_fd;
291     }
292     close(fd);
293     object_unref(OBJECT(sioc));
294     kill(getpid(), SIGTERM);
295     return (void *) EXIT_SUCCESS;
296 
297 out_fd:
298     close(fd);
299 out_socket:
300     object_unref(OBJECT(sioc));
301 out:
302     kill(getpid(), SIGTERM);
303     return (void *) EXIT_FAILURE;
304 }
305 
306 static int nbd_can_accept(void)
307 {
308     return nb_fds < shared;
309 }
310 
311 static void nbd_export_closed(NBDExport *exp)
312 {
313     assert(state == TERMINATING);
314     state = TERMINATED;
315 }
316 
317 static void nbd_update_server_watch(void);
318 
319 static void nbd_client_closed(NBDClient *client)
320 {
321     nb_fds--;
322     if (nb_fds == 0 && !persistent && state == RUNNING) {
323         state = TERMINATE;
324     }
325     nbd_update_server_watch();
326     nbd_client_put(client);
327 }
328 
329 static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque)
330 {
331     QIOChannelSocket *cioc;
332 
333     cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
334                                      NULL);
335     if (!cioc) {
336         return TRUE;
337     }
338 
339     if (state >= TERMINATE) {
340         object_unref(OBJECT(cioc));
341         return TRUE;
342     }
343 
344     nb_fds++;
345     nbd_update_server_watch();
346     nbd_client_new(newproto ? NULL : exp, cioc,
347                    tlscreds, NULL, nbd_client_closed);
348     object_unref(OBJECT(cioc));
349 
350     return TRUE;
351 }
352 
353 static void nbd_update_server_watch(void)
354 {
355     if (nbd_can_accept()) {
356         if (server_watch == -1) {
357             server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc),
358                                                  G_IO_IN,
359                                                  nbd_accept,
360                                                  NULL, NULL);
361         }
362     } else {
363         if (server_watch != -1) {
364             g_source_remove(server_watch);
365             server_watch = -1;
366         }
367     }
368 }
369 
370 
371 static SocketAddress *nbd_build_socket_address(const char *sockpath,
372                                                const char *bindto,
373                                                const char *port)
374 {
375     SocketAddress *saddr;
376 
377     saddr = g_new0(SocketAddress, 1);
378     if (sockpath) {
379         saddr->type = SOCKET_ADDRESS_KIND_UNIX;
380         saddr->u.q_unix = g_new0(UnixSocketAddress, 1);
381         saddr->u.q_unix->path = g_strdup(sockpath);
382     } else {
383         InetSocketAddress *inet;
384         saddr->type = SOCKET_ADDRESS_KIND_INET;
385         inet = saddr->u.inet = g_new0(InetSocketAddress, 1);
386         inet->host = g_strdup(bindto);
387         if (port) {
388             inet->port = g_strdup(port);
389         } else  {
390             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
391         }
392     }
393 
394     return saddr;
395 }
396 
397 
398 static QemuOptsList file_opts = {
399     .name = "file",
400     .implied_opt_name = "file",
401     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
402     .desc = {
403         /* no elements => accept any params */
404         { /* end of list */ }
405     },
406 };
407 
408 static QemuOptsList qemu_object_opts = {
409     .name = "object",
410     .implied_opt_name = "qom-type",
411     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
412     .desc = {
413         { }
414     },
415 };
416 
417 
418 
419 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
420 {
421     Object *obj;
422     QCryptoTLSCreds *creds;
423 
424     obj = object_resolve_path_component(
425         object_get_objects_root(), id);
426     if (!obj) {
427         error_setg(errp, "No TLS credentials with id '%s'",
428                    id);
429         return NULL;
430     }
431     creds = (QCryptoTLSCreds *)
432         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
433     if (!creds) {
434         error_setg(errp, "Object with id '%s' is not TLS credentials",
435                    id);
436         return NULL;
437     }
438 
439     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
440         error_setg(errp,
441                    "Expecting TLS credentials with a server endpoint");
442         return NULL;
443     }
444     object_ref(obj);
445     return creds;
446 }
447 
448 
449 int main(int argc, char **argv)
450 {
451     BlockBackend *blk;
452     BlockDriverState *bs;
453     off_t dev_offset = 0;
454     uint32_t nbdflags = 0;
455     bool disconnect = false;
456     const char *bindto = "0.0.0.0";
457     const char *port = NULL;
458     char *sockpath = NULL;
459     char *device = NULL;
460     off_t fd_size;
461     QemuOpts *sn_opts = NULL;
462     const char *sn_id_or_name = NULL;
463     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:";
464     struct option lopt[] = {
465         { "help", no_argument, NULL, 'h' },
466         { "version", no_argument, NULL, 'V' },
467         { "bind", required_argument, NULL, 'b' },
468         { "port", required_argument, NULL, 'p' },
469         { "socket", required_argument, NULL, 'k' },
470         { "offset", required_argument, NULL, 'o' },
471         { "read-only", no_argument, NULL, 'r' },
472         { "partition", required_argument, NULL, 'P' },
473         { "connect", required_argument, NULL, 'c' },
474         { "disconnect", no_argument, NULL, 'd' },
475         { "snapshot", no_argument, NULL, 's' },
476         { "load-snapshot", required_argument, NULL, 'l' },
477         { "nocache", no_argument, NULL, 'n' },
478         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
479         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
480         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
481         { "detect-zeroes", required_argument, NULL,
482           QEMU_NBD_OPT_DETECT_ZEROES },
483         { "shared", required_argument, NULL, 'e' },
484         { "format", required_argument, NULL, 'f' },
485         { "persistent", no_argument, NULL, 't' },
486         { "verbose", no_argument, NULL, 'v' },
487         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
488         { "export-name", required_argument, NULL, 'x' },
489         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
490         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
491         { NULL, 0, NULL, 0 }
492     };
493     int ch;
494     int opt_ind = 0;
495     char *end;
496     int flags = BDRV_O_RDWR;
497     int partition = -1;
498     int ret = 0;
499     bool seen_cache = false;
500     bool seen_discard = false;
501     bool seen_aio = false;
502     pthread_t client_thread;
503     const char *fmt = NULL;
504     Error *local_err = NULL;
505     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
506     QDict *options = NULL;
507     const char *export_name = NULL;
508     const char *tlscredsid = NULL;
509     bool imageOpts = false;
510 
511     /* The client thread uses SIGTERM to interrupt the server.  A signal
512      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
513      */
514     struct sigaction sa_sigterm;
515     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
516     sa_sigterm.sa_handler = termsig_handler;
517     sigaction(SIGTERM, &sa_sigterm, NULL);
518     module_call_init(MODULE_INIT_QOM);
519     qemu_add_opts(&qemu_object_opts);
520     qemu_init_exec_dir(argv[0]);
521 
522     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
523         switch (ch) {
524         case 's':
525             flags |= BDRV_O_SNAPSHOT;
526             break;
527         case 'n':
528             optarg = (char *) "none";
529             /* fallthrough */
530         case QEMU_NBD_OPT_CACHE:
531             if (seen_cache) {
532                 error_report("-n and --cache can only be specified once");
533                 exit(EXIT_FAILURE);
534             }
535             seen_cache = true;
536             if (bdrv_parse_cache_flags(optarg, &flags) == -1) {
537                 error_report("Invalid cache mode `%s'", optarg);
538                 exit(EXIT_FAILURE);
539             }
540             break;
541         case QEMU_NBD_OPT_AIO:
542             if (seen_aio) {
543                 error_report("--aio can only be specified once");
544                 exit(EXIT_FAILURE);
545             }
546             seen_aio = true;
547             if (!strcmp(optarg, "native")) {
548                 flags |= BDRV_O_NATIVE_AIO;
549             } else if (!strcmp(optarg, "threads")) {
550                 /* this is the default */
551             } else {
552                error_report("invalid aio mode `%s'", optarg);
553                exit(EXIT_FAILURE);
554             }
555             break;
556         case QEMU_NBD_OPT_DISCARD:
557             if (seen_discard) {
558                 error_report("--discard can only be specified once");
559                 exit(EXIT_FAILURE);
560             }
561             seen_discard = true;
562             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
563                 error_report("Invalid discard mode `%s'", optarg);
564                 exit(EXIT_FAILURE);
565             }
566             break;
567         case QEMU_NBD_OPT_DETECT_ZEROES:
568             detect_zeroes =
569                 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
570                                 optarg,
571                                 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX,
572                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
573                                 &local_err);
574             if (local_err) {
575                 error_reportf_err(local_err,
576                                   "Failed to parse detect_zeroes mode: ");
577                 exit(EXIT_FAILURE);
578             }
579             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
580                 !(flags & BDRV_O_UNMAP)) {
581                 error_report("setting detect-zeroes to unmap is not allowed "
582                              "without setting discard operation to unmap");
583                 exit(EXIT_FAILURE);
584             }
585             break;
586         case 'b':
587             bindto = optarg;
588             break;
589         case 'p':
590             port = optarg;
591             break;
592         case 'o':
593                 dev_offset = strtoll (optarg, &end, 0);
594             if (*end) {
595                 error_report("Invalid offset `%s'", optarg);
596                 exit(EXIT_FAILURE);
597             }
598             if (dev_offset < 0) {
599                 error_report("Offset must be positive `%s'", optarg);
600                 exit(EXIT_FAILURE);
601             }
602             break;
603         case 'l':
604             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
605                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
606                                                   optarg, false);
607                 if (!sn_opts) {
608                     error_report("Failed in parsing snapshot param `%s'",
609                                  optarg);
610                     exit(EXIT_FAILURE);
611                 }
612             } else {
613                 sn_id_or_name = optarg;
614             }
615             /* fall through */
616         case 'r':
617             nbdflags |= NBD_FLAG_READ_ONLY;
618             flags &= ~BDRV_O_RDWR;
619             break;
620         case 'P':
621             partition = strtol(optarg, &end, 0);
622             if (*end) {
623                 error_report("Invalid partition `%s'", optarg);
624                 exit(EXIT_FAILURE);
625             }
626             if (partition < 1 || partition > 8) {
627                 error_report("Invalid partition %d", partition);
628                 exit(EXIT_FAILURE);
629             }
630             break;
631         case 'k':
632             sockpath = optarg;
633             if (sockpath[0] != '/') {
634                 error_report("socket path must be absolute");
635                 exit(EXIT_FAILURE);
636             }
637             break;
638         case 'd':
639             disconnect = true;
640             break;
641         case 'c':
642             device = optarg;
643             break;
644         case 'e':
645             shared = strtol(optarg, &end, 0);
646             if (*end) {
647                 error_report("Invalid shared device number '%s'", optarg);
648                 exit(EXIT_FAILURE);
649             }
650             if (shared < 1) {
651                 error_report("Shared device number must be greater than 0");
652                 exit(EXIT_FAILURE);
653             }
654             break;
655         case 'f':
656             fmt = optarg;
657             break;
658         case 't':
659             persistent = 1;
660             break;
661         case 'x':
662             export_name = optarg;
663             break;
664         case 'v':
665             verbose = 1;
666             break;
667         case 'V':
668             version(argv[0]);
669             exit(0);
670             break;
671         case 'h':
672             usage(argv[0]);
673             exit(0);
674             break;
675         case '?':
676             error_report("Try `%s --help' for more information.", argv[0]);
677             exit(EXIT_FAILURE);
678         case QEMU_NBD_OPT_OBJECT: {
679             QemuOpts *opts;
680             opts = qemu_opts_parse_noisily(&qemu_object_opts,
681                                            optarg, true);
682             if (!opts) {
683                 exit(EXIT_FAILURE);
684             }
685         }   break;
686         case QEMU_NBD_OPT_TLSCREDS:
687             tlscredsid = optarg;
688             break;
689         case QEMU_NBD_OPT_IMAGE_OPTS:
690             imageOpts = true;
691             break;
692         }
693     }
694 
695     if ((argc - optind) != 1) {
696         error_report("Invalid number of arguments");
697         error_printf("Try `%s --help' for more information.\n", argv[0]);
698         exit(EXIT_FAILURE);
699     }
700 
701     if (qemu_opts_foreach(&qemu_object_opts,
702                           user_creatable_add_opts_foreach,
703                           NULL, &local_err)) {
704         error_report_err(local_err);
705         exit(EXIT_FAILURE);
706     }
707 
708     if (tlscredsid) {
709         if (sockpath) {
710             error_report("TLS is only supported with IPv4/IPv6");
711             exit(EXIT_FAILURE);
712         }
713         if (device) {
714             error_report("TLS is not supported with a host device");
715             exit(EXIT_FAILURE);
716         }
717         if (!export_name) {
718             /* Set the default NBD protocol export name, since
719              * we *must* use new style protocol for TLS */
720             export_name = "";
721         }
722         tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);
723         if (local_err) {
724             error_report("Failed to get TLS creds %s",
725                          error_get_pretty(local_err));
726             exit(EXIT_FAILURE);
727         }
728     }
729 
730     if (disconnect) {
731         int nbdfd = open(argv[optind], O_RDWR);
732         if (nbdfd < 0) {
733             error_report("Cannot open %s: %s", argv[optind],
734                          strerror(errno));
735             exit(EXIT_FAILURE);
736         }
737         nbd_disconnect(nbdfd);
738 
739         close(nbdfd);
740 
741         printf("%s disconnected\n", argv[optind]);
742 
743         return 0;
744     }
745 
746     if (device && !verbose) {
747         int stderr_fd[2];
748         pid_t pid;
749         int ret;
750 
751         if (qemu_pipe(stderr_fd) < 0) {
752             error_report("Error setting up communication pipe: %s",
753                          strerror(errno));
754             exit(EXIT_FAILURE);
755         }
756 
757         /* Now daemonize, but keep a communication channel open to
758          * print errors and exit with the proper status code.
759          */
760         pid = fork();
761         if (pid < 0) {
762             error_report("Failed to fork: %s", strerror(errno));
763             exit(EXIT_FAILURE);
764         } else if (pid == 0) {
765             close(stderr_fd[0]);
766             ret = qemu_daemon(1, 0);
767 
768             /* Temporarily redirect stderr to the parent's pipe...  */
769             dup2(stderr_fd[1], STDERR_FILENO);
770             if (ret < 0) {
771                 error_report("Failed to daemonize: %s", strerror(errno));
772                 exit(EXIT_FAILURE);
773             }
774 
775             /* ... close the descriptor we inherited and go on.  */
776             close(stderr_fd[1]);
777         } else {
778             bool errors = false;
779             char *buf;
780 
781             /* In the parent.  Print error messages from the child until
782              * it closes the pipe.
783              */
784             close(stderr_fd[1]);
785             buf = g_malloc(1024);
786             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
787                 errors = true;
788                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
789                 if (ret < 0) {
790                     exit(EXIT_FAILURE);
791                 }
792             }
793             if (ret < 0) {
794                 error_report("Cannot read from daemon: %s",
795                              strerror(errno));
796                 exit(EXIT_FAILURE);
797             }
798 
799             /* Usually the daemon should not print any message.
800              * Exit with zero status in that case.
801              */
802             exit(errors);
803         }
804     }
805 
806     if (device != NULL && sockpath == NULL) {
807         sockpath = g_malloc(128);
808         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
809     }
810 
811     saddr = nbd_build_socket_address(sockpath, bindto, port);
812 
813     if (qemu_init_main_loop(&local_err)) {
814         error_report_err(local_err);
815         exit(EXIT_FAILURE);
816     }
817     bdrv_init();
818     atexit(bdrv_close_all);
819 
820     srcpath = argv[optind];
821     if (imageOpts) {
822         QemuOpts *opts;
823         if (fmt) {
824             error_report("--image-opts and -f are mutually exclusive");
825             exit(EXIT_FAILURE);
826         }
827         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
828         if (!opts) {
829             qemu_opts_reset(&file_opts);
830             exit(EXIT_FAILURE);
831         }
832         options = qemu_opts_to_qdict(opts, NULL);
833         qemu_opts_reset(&file_opts);
834         blk = blk_new_open("hda", NULL, NULL, options, flags, &local_err);
835     } else {
836         if (fmt) {
837             options = qdict_new();
838             qdict_put(options, "driver", qstring_from_str(fmt));
839         }
840         blk = blk_new_open("hda", srcpath, NULL, options, flags, &local_err);
841     }
842 
843     if (!blk) {
844         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
845                           argv[optind]);
846         exit(EXIT_FAILURE);
847     }
848     bs = blk_bs(blk);
849 
850     if (sn_opts) {
851         ret = bdrv_snapshot_load_tmp(bs,
852                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
853                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
854                                      &local_err);
855     } else if (sn_id_or_name) {
856         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
857                                                    &local_err);
858     }
859     if (ret < 0) {
860         error_reportf_err(local_err, "Failed to load snapshot: ");
861         exit(EXIT_FAILURE);
862     }
863 
864     bs->detect_zeroes = detect_zeroes;
865     fd_size = blk_getlength(blk);
866     if (fd_size < 0) {
867         error_report("Failed to determine the image length: %s",
868                      strerror(-fd_size));
869         exit(EXIT_FAILURE);
870     }
871 
872     if (partition != -1) {
873         ret = find_partition(blk, partition, &dev_offset, &fd_size);
874         if (ret < 0) {
875             error_report("Could not find partition %d: %s", partition,
876                          strerror(-ret));
877             exit(EXIT_FAILURE);
878         }
879     }
880 
881     exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed,
882                          &local_err);
883     if (!exp) {
884         error_report_err(local_err);
885         exit(EXIT_FAILURE);
886     }
887     if (export_name) {
888         nbd_export_set_name(exp, export_name);
889         newproto = true;
890     }
891 
892     server_ioc = qio_channel_socket_new();
893     if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) {
894         object_unref(OBJECT(server_ioc));
895         error_report_err(local_err);
896         return 1;
897     }
898 
899     if (device) {
900         int ret;
901 
902         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
903         if (ret != 0) {
904             error_report("Failed to create client thread: %s", strerror(ret));
905             exit(EXIT_FAILURE);
906         }
907     } else {
908         /* Shut up GCC warnings.  */
909         memset(&client_thread, 0, sizeof(client_thread));
910     }
911 
912     nbd_update_server_watch();
913 
914     /* now when the initialization is (almost) complete, chdir("/")
915      * to free any busy filesystems */
916     if (chdir("/") < 0) {
917         error_report("Could not chdir to root directory: %s",
918                      strerror(errno));
919         exit(EXIT_FAILURE);
920     }
921 
922     state = RUNNING;
923     do {
924         main_loop_wait(false);
925         if (state == TERMINATE) {
926             state = TERMINATING;
927             nbd_export_close(exp);
928             nbd_export_put(exp);
929             exp = NULL;
930         }
931     } while (state != TERMINATED);
932 
933     blk_unref(blk);
934     if (sockpath) {
935         unlink(sockpath);
936     }
937 
938     qemu_opts_del(sn_opts);
939 
940     if (device) {
941         void *ret;
942         pthread_join(client_thread, &ret);
943         exit(ret != NULL);
944     } else {
945         exit(EXIT_SUCCESS);
946     }
947 }
948