kvm: add kvm_device_supported() helper function
[qemu/ar7.git] / qemu-nbd.c
blobca4a724d25cb15d48f7462ead86b50bf5882fe5a
1 /*
2 * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
4 * Network Block Device
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.
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.
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/>.
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"
35 #include <getopt.h>
36 #include <libgen.h>
37 #include <pthread.h>
39 #define SOCKET_PATH "/var/lock/qemu-nbd-%s"
40 #define QEMU_NBD_OPT_CACHE 256
41 #define QEMU_NBD_OPT_AIO 257
42 #define QEMU_NBD_OPT_DISCARD 258
43 #define QEMU_NBD_OPT_DETECT_ZEROES 259
44 #define QEMU_NBD_OPT_OBJECT 260
45 #define QEMU_NBD_OPT_TLSCREDS 261
46 #define QEMU_NBD_OPT_IMAGE_OPTS 262
48 static NBDExport *exp;
49 static bool newproto;
50 static int verbose;
51 static char *srcpath;
52 static SocketAddress *saddr;
53 static int persistent = 0;
54 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
55 static int shared = 1;
56 static int nb_fds;
57 static QIOChannelSocket *server_ioc;
58 static int server_watch = -1;
59 static QCryptoTLSCreds *tlscreds;
61 static void usage(const char *name)
63 (printf) (
64 "Usage: %s [OPTIONS] FILE\n"
65 "QEMU Disk Network Block Device Server\n"
66 "\n"
67 " -h, --help display this help and exit\n"
68 " -V, --version output version information and exit\n"
69 "\n"
70 "Connection properties:\n"
71 " -p, --port=PORT port to listen on (default `%d')\n"
72 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n"
73 " -k, --socket=PATH path to the unix socket\n"
74 " (default '"SOCKET_PATH"')\n"
75 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n"
76 " -t, --persistent don't exit on the last connection\n"
77 " -v, --verbose display extra debugging information\n"
78 "\n"
79 "Exposing part of the image:\n"
80 " -o, --offset=OFFSET offset into the image\n"
81 " -P, --partition=NUM only expose partition NUM\n"
82 "\n"
83 "General purpose options:\n"
84 " --object type,id=ID,... define an object such as 'secret' for providing\n"
85 " passwords and/or encryption keys\n"
86 #ifdef __linux__
87 "Kernel NBD client support:\n"
88 " -c, --connect=DEV connect FILE to the local NBD device DEV\n"
89 " -d, --disconnect disconnect the specified device\n"
90 "\n"
91 #endif
92 "\n"
93 "Block device options:\n"
94 " -f, --format=FORMAT set image format (raw, qcow2, ...)\n"
95 " -r, --read-only export read-only\n"
96 " -s, --snapshot use FILE as an external snapshot, create a temporary\n"
97 " file with backing_file=FILE, redirect the write to\n"
98 " the temporary one\n"
99 " -l, --load-snapshot=SNAPSHOT_PARAM\n"
100 " load an internal snapshot inside FILE and export it\n"
101 " as an read-only device, SNAPSHOT_PARAM format is\n"
102 " 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
103 " '[ID_OR_NAME]'\n"
104 " -n, --nocache disable host cache\n"
105 " --cache=MODE set cache mode (none, writeback, ...)\n"
106 " --aio=MODE set AIO mode (native or threads)\n"
107 " --discard=MODE set discard mode (ignore, unmap)\n"
108 " --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n"
109 " --image-opts treat FILE as a full set of image options\n"
110 "\n"
111 "Report bugs to <qemu-devel@nongnu.org>\n"
112 , name, NBD_DEFAULT_PORT, "DEVICE");
115 static void version(const char *name)
117 printf(
118 "%s version 0.0.1\n"
119 "Written by Anthony Liguori.\n"
120 "\n"
121 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
122 "This is free software; see the source for copying conditions. There is NO\n"
123 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
124 , name);
127 struct partition_record
129 uint8_t bootable;
130 uint8_t start_head;
131 uint32_t start_cylinder;
132 uint8_t start_sector;
133 uint8_t system;
134 uint8_t end_head;
135 uint8_t end_cylinder;
136 uint8_t end_sector;
137 uint32_t start_sector_abs;
138 uint32_t nb_sectors_abs;
141 static void read_partition(uint8_t *p, struct partition_record *r)
143 r->bootable = p[0];
144 r->start_head = p[1];
145 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
146 r->start_sector = p[2] & 0x3f;
147 r->system = p[4];
148 r->end_head = p[5];
149 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
150 r->end_sector = p[6] & 0x3f;
152 r->start_sector_abs = le32_to_cpup((uint32_t *)(p + 8));
153 r->nb_sectors_abs = le32_to_cpup((uint32_t *)(p + 12));
156 static int find_partition(BlockBackend *blk, int partition,
157 off_t *offset, off_t *size)
159 struct partition_record mbr[4];
160 uint8_t data[512];
161 int i;
162 int ext_partnum = 4;
163 int ret;
165 if ((ret = blk_read(blk, 0, data, 1)) < 0) {
166 error_report("error while reading: %s", strerror(-ret));
167 exit(EXIT_FAILURE);
170 if (data[510] != 0x55 || data[511] != 0xaa) {
171 return -EINVAL;
174 for (i = 0; i < 4; i++) {
175 read_partition(&data[446 + 16 * i], &mbr[i]);
177 if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
178 continue;
181 if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
182 struct partition_record ext[4];
183 uint8_t data1[512];
184 int j;
186 if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) {
187 error_report("error while reading: %s", strerror(-ret));
188 exit(EXIT_FAILURE);
191 for (j = 0; j < 4; j++) {
192 read_partition(&data1[446 + 16 * j], &ext[j]);
193 if (!ext[j].system || !ext[j].nb_sectors_abs) {
194 continue;
197 if ((ext_partnum + j + 1) == partition) {
198 *offset = (uint64_t)ext[j].start_sector_abs << 9;
199 *size = (uint64_t)ext[j].nb_sectors_abs << 9;
200 return 0;
203 ext_partnum += 4;
204 } else if ((i + 1) == partition) {
205 *offset = (uint64_t)mbr[i].start_sector_abs << 9;
206 *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
207 return 0;
211 return -ENOENT;
214 static void termsig_handler(int signum)
216 state = TERMINATE;
217 qemu_notify_event();
221 static void *show_parts(void *arg)
223 char *device = arg;
224 int nbd;
226 /* linux just needs an open() to trigger
227 * the partition table update
228 * but remember to load the module with max_part != 0 :
229 * modprobe nbd max_part=63
231 nbd = open(device, O_RDWR);
232 if (nbd >= 0) {
233 close(nbd);
235 return NULL;
238 static void *nbd_client_thread(void *arg)
240 char *device = arg;
241 off_t size;
242 uint32_t nbdflags;
243 QIOChannelSocket *sioc;
244 int fd;
245 int ret;
246 pthread_t show_parts_thread;
247 Error *local_error = NULL;
249 sioc = qio_channel_socket_new();
250 if (qio_channel_socket_connect_sync(sioc,
251 saddr,
252 &local_error) < 0) {
253 error_report_err(local_error);
254 goto out;
257 ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL, &nbdflags,
258 NULL, NULL, NULL,
259 &size, &local_error);
260 if (ret < 0) {
261 if (local_error) {
262 error_report_err(local_error);
264 goto out_socket;
267 fd = open(device, O_RDWR);
268 if (fd < 0) {
269 /* Linux-only, we can use %m in printf. */
270 error_report("Failed to open %s: %m", device);
271 goto out_socket;
274 ret = nbd_init(fd, sioc, nbdflags, size);
275 if (ret < 0) {
276 goto out_fd;
279 /* update partition table */
280 pthread_create(&show_parts_thread, NULL, show_parts, device);
282 if (verbose) {
283 fprintf(stderr, "NBD device %s is now connected to %s\n",
284 device, srcpath);
285 } else {
286 /* Close stderr so that the qemu-nbd process exits. */
287 dup2(STDOUT_FILENO, STDERR_FILENO);
290 ret = nbd_client(fd);
291 if (ret) {
292 goto out_fd;
294 close(fd);
295 object_unref(OBJECT(sioc));
296 kill(getpid(), SIGTERM);
297 return (void *) EXIT_SUCCESS;
299 out_fd:
300 close(fd);
301 out_socket:
302 object_unref(OBJECT(sioc));
303 out:
304 kill(getpid(), SIGTERM);
305 return (void *) EXIT_FAILURE;
308 static int nbd_can_accept(void)
310 return nb_fds < shared;
313 static void nbd_export_closed(NBDExport *exp)
315 assert(state == TERMINATING);
316 state = TERMINATED;
319 static void nbd_update_server_watch(void);
321 static void nbd_client_closed(NBDClient *client)
323 nb_fds--;
324 if (nb_fds == 0 && !persistent && state == RUNNING) {
325 state = TERMINATE;
327 nbd_update_server_watch();
328 nbd_client_put(client);
331 static gboolean nbd_accept(QIOChannel *ioc, GIOCondition cond, gpointer opaque)
333 QIOChannelSocket *cioc;
335 cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
336 NULL);
337 if (!cioc) {
338 return TRUE;
341 if (state >= TERMINATE) {
342 object_unref(OBJECT(cioc));
343 return TRUE;
346 nb_fds++;
347 nbd_update_server_watch();
348 nbd_client_new(newproto ? NULL : exp, cioc,
349 tlscreds, NULL, nbd_client_closed);
350 object_unref(OBJECT(cioc));
352 return TRUE;
355 static void nbd_update_server_watch(void)
357 if (nbd_can_accept()) {
358 if (server_watch == -1) {
359 server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc),
360 G_IO_IN,
361 nbd_accept,
362 NULL, NULL);
364 } else {
365 if (server_watch != -1) {
366 g_source_remove(server_watch);
367 server_watch = -1;
373 static SocketAddress *nbd_build_socket_address(const char *sockpath,
374 const char *bindto,
375 const char *port)
377 SocketAddress *saddr;
379 saddr = g_new0(SocketAddress, 1);
380 if (sockpath) {
381 saddr->type = SOCKET_ADDRESS_KIND_UNIX;
382 saddr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
383 saddr->u.q_unix.data->path = g_strdup(sockpath);
384 } else {
385 InetSocketAddress *inet;
386 saddr->type = SOCKET_ADDRESS_KIND_INET;
387 inet = saddr->u.inet.data = g_new0(InetSocketAddress, 1);
388 inet->host = g_strdup(bindto);
389 if (port) {
390 inet->port = g_strdup(port);
391 } else {
392 inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
396 return saddr;
400 static QemuOptsList file_opts = {
401 .name = "file",
402 .implied_opt_name = "file",
403 .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
404 .desc = {
405 /* no elements => accept any params */
406 { /* end of list */ }
410 static QemuOptsList qemu_object_opts = {
411 .name = "object",
412 .implied_opt_name = "qom-type",
413 .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
414 .desc = {
421 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
423 Object *obj;
424 QCryptoTLSCreds *creds;
426 obj = object_resolve_path_component(
427 object_get_objects_root(), id);
428 if (!obj) {
429 error_setg(errp, "No TLS credentials with id '%s'",
430 id);
431 return NULL;
433 creds = (QCryptoTLSCreds *)
434 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
435 if (!creds) {
436 error_setg(errp, "Object with id '%s' is not TLS credentials",
437 id);
438 return NULL;
441 if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
442 error_setg(errp,
443 "Expecting TLS credentials with a server endpoint");
444 return NULL;
446 object_ref(obj);
447 return creds;
451 int main(int argc, char **argv)
453 BlockBackend *blk;
454 BlockDriverState *bs;
455 off_t dev_offset = 0;
456 uint32_t nbdflags = 0;
457 bool disconnect = false;
458 const char *bindto = "0.0.0.0";
459 const char *port = NULL;
460 char *sockpath = NULL;
461 char *device = NULL;
462 off_t fd_size;
463 QemuOpts *sn_opts = NULL;
464 const char *sn_id_or_name = NULL;
465 const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:";
466 struct option lopt[] = {
467 { "help", no_argument, NULL, 'h' },
468 { "version", no_argument, NULL, 'V' },
469 { "bind", required_argument, NULL, 'b' },
470 { "port", required_argument, NULL, 'p' },
471 { "socket", required_argument, NULL, 'k' },
472 { "offset", required_argument, NULL, 'o' },
473 { "read-only", no_argument, NULL, 'r' },
474 { "partition", required_argument, NULL, 'P' },
475 { "connect", required_argument, NULL, 'c' },
476 { "disconnect", no_argument, NULL, 'd' },
477 { "snapshot", no_argument, NULL, 's' },
478 { "load-snapshot", required_argument, NULL, 'l' },
479 { "nocache", no_argument, NULL, 'n' },
480 { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
481 { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
482 { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
483 { "detect-zeroes", required_argument, NULL,
484 QEMU_NBD_OPT_DETECT_ZEROES },
485 { "shared", required_argument, NULL, 'e' },
486 { "format", required_argument, NULL, 'f' },
487 { "persistent", no_argument, NULL, 't' },
488 { "verbose", no_argument, NULL, 'v' },
489 { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
490 { "export-name", required_argument, NULL, 'x' },
491 { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
492 { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
493 { NULL, 0, NULL, 0 }
495 int ch;
496 int opt_ind = 0;
497 char *end;
498 int flags = BDRV_O_RDWR;
499 int partition = -1;
500 int ret = 0;
501 bool seen_cache = false;
502 bool seen_discard = false;
503 bool seen_aio = false;
504 pthread_t client_thread;
505 const char *fmt = NULL;
506 Error *local_err = NULL;
507 BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
508 QDict *options = NULL;
509 const char *export_name = NULL;
510 const char *tlscredsid = NULL;
511 bool imageOpts = false;
512 bool writethrough = true;
514 /* The client thread uses SIGTERM to interrupt the server. A signal
515 * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
517 struct sigaction sa_sigterm;
518 memset(&sa_sigterm, 0, sizeof(sa_sigterm));
519 sa_sigterm.sa_handler = termsig_handler;
520 sigaction(SIGTERM, &sa_sigterm, NULL);
521 module_call_init(MODULE_INIT_QOM);
522 qemu_add_opts(&qemu_object_opts);
523 qemu_init_exec_dir(argv[0]);
525 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
526 switch (ch) {
527 case 's':
528 flags |= BDRV_O_SNAPSHOT;
529 break;
530 case 'n':
531 optarg = (char *) "none";
532 /* fallthrough */
533 case QEMU_NBD_OPT_CACHE:
534 if (seen_cache) {
535 error_report("-n and --cache can only be specified once");
536 exit(EXIT_FAILURE);
538 seen_cache = true;
539 if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
540 error_report("Invalid cache mode `%s'", optarg);
541 exit(EXIT_FAILURE);
543 break;
544 case QEMU_NBD_OPT_AIO:
545 if (seen_aio) {
546 error_report("--aio can only be specified once");
547 exit(EXIT_FAILURE);
549 seen_aio = true;
550 if (!strcmp(optarg, "native")) {
551 flags |= BDRV_O_NATIVE_AIO;
552 } else if (!strcmp(optarg, "threads")) {
553 /* this is the default */
554 } else {
555 error_report("invalid aio mode `%s'", optarg);
556 exit(EXIT_FAILURE);
558 break;
559 case QEMU_NBD_OPT_DISCARD:
560 if (seen_discard) {
561 error_report("--discard can only be specified once");
562 exit(EXIT_FAILURE);
564 seen_discard = true;
565 if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
566 error_report("Invalid discard mode `%s'", optarg);
567 exit(EXIT_FAILURE);
569 break;
570 case QEMU_NBD_OPT_DETECT_ZEROES:
571 detect_zeroes =
572 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
573 optarg,
574 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX,
575 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
576 &local_err);
577 if (local_err) {
578 error_reportf_err(local_err,
579 "Failed to parse detect_zeroes mode: ");
580 exit(EXIT_FAILURE);
582 if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
583 !(flags & BDRV_O_UNMAP)) {
584 error_report("setting detect-zeroes to unmap is not allowed "
585 "without setting discard operation to unmap");
586 exit(EXIT_FAILURE);
588 break;
589 case 'b':
590 bindto = optarg;
591 break;
592 case 'p':
593 port = optarg;
594 break;
595 case 'o':
596 dev_offset = strtoll (optarg, &end, 0);
597 if (*end) {
598 error_report("Invalid offset `%s'", optarg);
599 exit(EXIT_FAILURE);
601 if (dev_offset < 0) {
602 error_report("Offset must be positive `%s'", optarg);
603 exit(EXIT_FAILURE);
605 break;
606 case 'l':
607 if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
608 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
609 optarg, false);
610 if (!sn_opts) {
611 error_report("Failed in parsing snapshot param `%s'",
612 optarg);
613 exit(EXIT_FAILURE);
615 } else {
616 sn_id_or_name = optarg;
618 /* fall through */
619 case 'r':
620 nbdflags |= NBD_FLAG_READ_ONLY;
621 flags &= ~BDRV_O_RDWR;
622 break;
623 case 'P':
624 partition = strtol(optarg, &end, 0);
625 if (*end) {
626 error_report("Invalid partition `%s'", optarg);
627 exit(EXIT_FAILURE);
629 if (partition < 1 || partition > 8) {
630 error_report("Invalid partition %d", partition);
631 exit(EXIT_FAILURE);
633 break;
634 case 'k':
635 sockpath = optarg;
636 if (sockpath[0] != '/') {
637 error_report("socket path must be absolute");
638 exit(EXIT_FAILURE);
640 break;
641 case 'd':
642 disconnect = true;
643 break;
644 case 'c':
645 device = optarg;
646 break;
647 case 'e':
648 shared = strtol(optarg, &end, 0);
649 if (*end) {
650 error_report("Invalid shared device number '%s'", optarg);
651 exit(EXIT_FAILURE);
653 if (shared < 1) {
654 error_report("Shared device number must be greater than 0");
655 exit(EXIT_FAILURE);
657 break;
658 case 'f':
659 fmt = optarg;
660 break;
661 case 't':
662 persistent = 1;
663 break;
664 case 'x':
665 export_name = optarg;
666 break;
667 case 'v':
668 verbose = 1;
669 break;
670 case 'V':
671 version(argv[0]);
672 exit(0);
673 break;
674 case 'h':
675 usage(argv[0]);
676 exit(0);
677 break;
678 case '?':
679 error_report("Try `%s --help' for more information.", argv[0]);
680 exit(EXIT_FAILURE);
681 case QEMU_NBD_OPT_OBJECT: {
682 QemuOpts *opts;
683 opts = qemu_opts_parse_noisily(&qemu_object_opts,
684 optarg, true);
685 if (!opts) {
686 exit(EXIT_FAILURE);
688 } break;
689 case QEMU_NBD_OPT_TLSCREDS:
690 tlscredsid = optarg;
691 break;
692 case QEMU_NBD_OPT_IMAGE_OPTS:
693 imageOpts = true;
694 break;
698 if ((argc - optind) != 1) {
699 error_report("Invalid number of arguments");
700 error_printf("Try `%s --help' for more information.\n", argv[0]);
701 exit(EXIT_FAILURE);
704 if (qemu_opts_foreach(&qemu_object_opts,
705 user_creatable_add_opts_foreach,
706 NULL, &local_err)) {
707 error_report_err(local_err);
708 exit(EXIT_FAILURE);
711 if (tlscredsid) {
712 if (sockpath) {
713 error_report("TLS is only supported with IPv4/IPv6");
714 exit(EXIT_FAILURE);
716 if (device) {
717 error_report("TLS is not supported with a host device");
718 exit(EXIT_FAILURE);
720 if (!export_name) {
721 /* Set the default NBD protocol export name, since
722 * we *must* use new style protocol for TLS */
723 export_name = "";
725 tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);
726 if (local_err) {
727 error_report("Failed to get TLS creds %s",
728 error_get_pretty(local_err));
729 exit(EXIT_FAILURE);
733 if (disconnect) {
734 int nbdfd = open(argv[optind], O_RDWR);
735 if (nbdfd < 0) {
736 error_report("Cannot open %s: %s", argv[optind],
737 strerror(errno));
738 exit(EXIT_FAILURE);
740 nbd_disconnect(nbdfd);
742 close(nbdfd);
744 printf("%s disconnected\n", argv[optind]);
746 return 0;
749 if (device && !verbose) {
750 int stderr_fd[2];
751 pid_t pid;
752 int ret;
754 if (qemu_pipe(stderr_fd) < 0) {
755 error_report("Error setting up communication pipe: %s",
756 strerror(errno));
757 exit(EXIT_FAILURE);
760 /* Now daemonize, but keep a communication channel open to
761 * print errors and exit with the proper status code.
763 pid = fork();
764 if (pid < 0) {
765 error_report("Failed to fork: %s", strerror(errno));
766 exit(EXIT_FAILURE);
767 } else if (pid == 0) {
768 close(stderr_fd[0]);
769 ret = qemu_daemon(1, 0);
771 /* Temporarily redirect stderr to the parent's pipe... */
772 dup2(stderr_fd[1], STDERR_FILENO);
773 if (ret < 0) {
774 error_report("Failed to daemonize: %s", strerror(errno));
775 exit(EXIT_FAILURE);
778 /* ... close the descriptor we inherited and go on. */
779 close(stderr_fd[1]);
780 } else {
781 bool errors = false;
782 char *buf;
784 /* In the parent. Print error messages from the child until
785 * it closes the pipe.
787 close(stderr_fd[1]);
788 buf = g_malloc(1024);
789 while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
790 errors = true;
791 ret = qemu_write_full(STDERR_FILENO, buf, ret);
792 if (ret < 0) {
793 exit(EXIT_FAILURE);
796 if (ret < 0) {
797 error_report("Cannot read from daemon: %s",
798 strerror(errno));
799 exit(EXIT_FAILURE);
802 /* Usually the daemon should not print any message.
803 * Exit with zero status in that case.
805 exit(errors);
809 if (device != NULL && sockpath == NULL) {
810 sockpath = g_malloc(128);
811 snprintf(sockpath, 128, SOCKET_PATH, basename(device));
814 saddr = nbd_build_socket_address(sockpath, bindto, port);
816 if (qemu_init_main_loop(&local_err)) {
817 error_report_err(local_err);
818 exit(EXIT_FAILURE);
820 bdrv_init();
821 atexit(bdrv_close_all);
823 srcpath = argv[optind];
824 if (imageOpts) {
825 QemuOpts *opts;
826 if (fmt) {
827 error_report("--image-opts and -f are mutually exclusive");
828 exit(EXIT_FAILURE);
830 opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
831 if (!opts) {
832 qemu_opts_reset(&file_opts);
833 exit(EXIT_FAILURE);
835 options = qemu_opts_to_qdict(opts, NULL);
836 qemu_opts_reset(&file_opts);
837 blk = blk_new_open(NULL, NULL, options, flags, &local_err);
838 } else {
839 if (fmt) {
840 options = qdict_new();
841 qdict_put(options, "driver", qstring_from_str(fmt));
843 blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
846 if (!blk) {
847 error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
848 argv[optind]);
849 exit(EXIT_FAILURE);
851 bs = blk_bs(blk);
853 blk_set_enable_write_cache(blk, !writethrough);
855 if (sn_opts) {
856 ret = bdrv_snapshot_load_tmp(bs,
857 qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
858 qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
859 &local_err);
860 } else if (sn_id_or_name) {
861 ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
862 &local_err);
864 if (ret < 0) {
865 error_reportf_err(local_err, "Failed to load snapshot: ");
866 exit(EXIT_FAILURE);
869 bs->detect_zeroes = detect_zeroes;
870 fd_size = blk_getlength(blk);
871 if (fd_size < 0) {
872 error_report("Failed to determine the image length: %s",
873 strerror(-fd_size));
874 exit(EXIT_FAILURE);
877 if (partition != -1) {
878 ret = find_partition(blk, partition, &dev_offset, &fd_size);
879 if (ret < 0) {
880 error_report("Could not find partition %d: %s", partition,
881 strerror(-ret));
882 exit(EXIT_FAILURE);
886 exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed,
887 &local_err);
888 if (!exp) {
889 error_report_err(local_err);
890 exit(EXIT_FAILURE);
892 if (export_name) {
893 nbd_export_set_name(exp, export_name);
894 newproto = true;
897 server_ioc = qio_channel_socket_new();
898 if (qio_channel_socket_listen_sync(server_ioc, saddr, &local_err) < 0) {
899 object_unref(OBJECT(server_ioc));
900 error_report_err(local_err);
901 return 1;
904 if (device) {
905 int ret;
907 ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
908 if (ret != 0) {
909 error_report("Failed to create client thread: %s", strerror(ret));
910 exit(EXIT_FAILURE);
912 } else {
913 /* Shut up GCC warnings. */
914 memset(&client_thread, 0, sizeof(client_thread));
917 nbd_update_server_watch();
919 /* now when the initialization is (almost) complete, chdir("/")
920 * to free any busy filesystems */
921 if (chdir("/") < 0) {
922 error_report("Could not chdir to root directory: %s",
923 strerror(errno));
924 exit(EXIT_FAILURE);
927 state = RUNNING;
928 do {
929 main_loop_wait(false);
930 if (state == TERMINATE) {
931 state = TERMINATING;
932 nbd_export_close(exp);
933 nbd_export_put(exp);
934 exp = NULL;
936 } while (state != TERMINATED);
938 blk_unref(blk);
939 if (sockpath) {
940 unlink(sockpath);
943 qemu_opts_del(sn_opts);
945 if (device) {
946 void *ret;
947 pthread_join(client_thread, &ret);
948 exit(ret != NULL);
949 } else {
950 exit(EXIT_SUCCESS);