nbd: Add max-connections to nbd-server-start
[qemu.git] / qemu-nbd.c
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 <getopt.h>
21 #include <libgen.h>
22 #include <pthread.h>
23
24 #include "qemu-common.h"
25 #include "qapi/error.h"
26 #include "qemu/cutils.h"
27 #include "sysemu/block-backend.h"
28 #include "block/block_int.h"
29 #include "block/nbd.h"
30 #include "qemu/main-loop.h"
31 #include "qemu/module.h"
32 #include "qemu/option.h"
33 #include "qemu/error-report.h"
34 #include "qemu/config-file.h"
35 #include "qemu/bswap.h"
36 #include "qemu/log.h"
37 #include "qemu/systemd.h"
38 #include "block/snapshot.h"
39 #include "qapi/qmp/qdict.h"
40 #include "qapi/qmp/qstring.h"
41 #include "qom/object_interfaces.h"
42 #include "io/channel-socket.h"
43 #include "io/net-listener.h"
44 #include "crypto/init.h"
45 #include "trace/control.h"
46 #include "qemu-version.h"
47
48 #ifdef __linux__
49 #define HAVE_NBD_DEVICE 1
50 #else
51 #define HAVE_NBD_DEVICE 0
52 #endif
53
54 #define SOCKET_PATH "/var/lock/qemu-nbd-%s"
55 #define QEMU_NBD_OPT_CACHE 256
56 #define QEMU_NBD_OPT_AIO 257
57 #define QEMU_NBD_OPT_DISCARD 258
58 #define QEMU_NBD_OPT_DETECT_ZEROES 259
59 #define QEMU_NBD_OPT_OBJECT 260
60 #define QEMU_NBD_OPT_TLSCREDS 261
61 #define QEMU_NBD_OPT_IMAGE_OPTS 262
62 #define QEMU_NBD_OPT_FORK 263
63 #define QEMU_NBD_OPT_TLSAUTHZ 264
64 #define QEMU_NBD_OPT_PID_FILE 265
65
66 #define MBR_SIZE 512
67
68 static NBDExport *export;
69 static int verbose;
70 static char *srcpath;
71 static SocketAddress *saddr;
72 static int persistent = 0;
73 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
74 static int shared = 1;
75 static int nb_fds;
76 static QIONetListener *server;
77 static QCryptoTLSCreds *tlscreds;
78 static const char *tlsauthz;
79
80 static void usage(const char *name)
81 {
82 (printf) (
83 "Usage: %s [OPTIONS] FILE\n"
84 " or: %s -L [OPTIONS]\n"
85 "QEMU Disk Network Block Device Utility\n"
86 "\n"
87 " -h, --help display this help and exit\n"
88 " -V, --version output version information and exit\n"
89 "\n"
90 "Connection properties:\n"
91 " -p, --port=PORT port to listen on (default `%d')\n"
92 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n"
93 " -k, --socket=PATH path to the unix socket\n"
94 " (default '"SOCKET_PATH"')\n"
95 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n"
96 " -t, --persistent don't exit on the last connection\n"
97 " -v, --verbose display extra debugging information\n"
98 " -x, --export-name=NAME expose export by name (default is empty string)\n"
99 " -D, --description=TEXT export a human-readable description\n"
100 "\n"
101 "Exposing part of the image:\n"
102 " -o, --offset=OFFSET offset into the image\n"
103 " -B, --bitmap=NAME expose a persistent dirty bitmap\n"
104 "\n"
105 "General purpose options:\n"
106 " -L, --list list exports available from another NBD server\n"
107 " --object type,id=ID,... define an object such as 'secret' for providing\n"
108 " passwords and/or encryption keys\n"
109 " --tls-creds=ID use id of an earlier --object to provide TLS\n"
110 " --tls-authz=ID use id of an earlier --object to provide\n"
111 " authorization\n"
112 " -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
113 " specify tracing options\n"
114 " --fork fork off the server process and exit the parent\n"
115 " once the server is running\n"
116 " --pid-file=PATH store the server's process ID in the given file\n"
117 #if HAVE_NBD_DEVICE
118 "\n"
119 "Kernel NBD client support:\n"
120 " -c, --connect=DEV connect FILE to the local NBD device DEV\n"
121 " -d, --disconnect disconnect the specified device\n"
122 #endif
123 "\n"
124 "Block device options:\n"
125 " -f, --format=FORMAT set image format (raw, qcow2, ...)\n"
126 " -r, --read-only export read-only\n"
127 " -s, --snapshot use FILE as an external snapshot, create a temporary\n"
128 " file with backing_file=FILE, redirect the write to\n"
129 " the temporary one\n"
130 " -l, --load-snapshot=SNAPSHOT_PARAM\n"
131 " load an internal snapshot inside FILE and export it\n"
132 " as an read-only device, SNAPSHOT_PARAM format is\n"
133 " 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
134 " '[ID_OR_NAME]'\n"
135 " -n, --nocache disable host cache\n"
136 " --cache=MODE set cache mode (none, writeback, ...)\n"
137 " --aio=MODE set AIO mode (native, io_uring or threads)\n"
138 " --discard=MODE set discard mode (ignore, unmap)\n"
139 " --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n"
140 " --image-opts treat FILE as a full set of image options\n"
141 "\n"
142 QEMU_HELP_BOTTOM "\n"
143 , name, name, NBD_DEFAULT_PORT, "DEVICE");
144 }
145
146 static void version(const char *name)
147 {
148 printf(
149 "%s " QEMU_FULL_VERSION "\n"
150 "Written by Anthony Liguori.\n"
151 "\n"
152 QEMU_COPYRIGHT "\n"
153 "This is free software; see the source for copying conditions. There is NO\n"
154 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
155 , name);
156 }
157
158 #if HAVE_NBD_DEVICE
159 static void termsig_handler(int signum)
160 {
161 qatomic_cmpxchg(&state, RUNNING, TERMINATE);
162 qemu_notify_event();
163 }
164 #endif /* HAVE_NBD_DEVICE */
165
166 static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
167 const char *hostname)
168 {
169 int ret = EXIT_FAILURE;
170 int rc;
171 Error *err = NULL;
172 QIOChannelSocket *sioc;
173 NBDExportInfo *list;
174 int i, j;
175
176 sioc = qio_channel_socket_new();
177 if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
178 error_report_err(err);
179 return EXIT_FAILURE;
180 }
181 rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
182 &err);
183 if (rc < 0) {
184 if (err) {
185 error_report_err(err);
186 }
187 goto out;
188 }
189 printf("exports available: %d\n", rc);
190 for (i = 0; i < rc; i++) {
191 printf(" export: '%s'\n", list[i].name);
192 if (list[i].description && *list[i].description) {
193 printf(" description: %s\n", list[i].description);
194 }
195 if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
196 static const char *const flag_names[] = {
197 [NBD_FLAG_READ_ONLY_BIT] = "readonly",
198 [NBD_FLAG_SEND_FLUSH_BIT] = "flush",
199 [NBD_FLAG_SEND_FUA_BIT] = "fua",
200 [NBD_FLAG_ROTATIONAL_BIT] = "rotational",
201 [NBD_FLAG_SEND_TRIM_BIT] = "trim",
202 [NBD_FLAG_SEND_WRITE_ZEROES_BIT] = "zeroes",
203 [NBD_FLAG_SEND_DF_BIT] = "df",
204 [NBD_FLAG_CAN_MULTI_CONN_BIT] = "multi",
205 [NBD_FLAG_SEND_RESIZE_BIT] = "resize",
206 [NBD_FLAG_SEND_CACHE_BIT] = "cache",
207 [NBD_FLAG_SEND_FAST_ZERO_BIT] = "fast-zero",
208 };
209
210 printf(" size: %" PRIu64 "\n", list[i].size);
211 printf(" flags: 0x%x (", list[i].flags);
212 for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) {
213 if (flag_names[bit] && (list[i].flags & (1 << bit))) {
214 printf(" %s", flag_names[bit]);
215 }
216 }
217 printf(" )\n");
218 }
219 if (list[i].min_block) {
220 printf(" min block: %u\n", list[i].min_block);
221 printf(" opt block: %u\n", list[i].opt_block);
222 printf(" max block: %u\n", list[i].max_block);
223 }
224 if (list[i].n_contexts) {
225 printf(" available meta contexts: %d\n", list[i].n_contexts);
226 for (j = 0; j < list[i].n_contexts; j++) {
227 printf(" %s\n", list[i].contexts[j]);
228 }
229 }
230 }
231 nbd_free_export_list(list, rc);
232
233 ret = EXIT_SUCCESS;
234 out:
235 object_unref(OBJECT(sioc));
236 return ret;
237 }
238
239
240 #if HAVE_NBD_DEVICE
241 static void *show_parts(void *arg)
242 {
243 char *device = arg;
244 int nbd;
245
246 /* linux just needs an open() to trigger
247 * the partition table update
248 * but remember to load the module with max_part != 0 :
249 * modprobe nbd max_part=63
250 */
251 nbd = open(device, O_RDWR);
252 if (nbd >= 0) {
253 close(nbd);
254 }
255 return NULL;
256 }
257
258 static void *nbd_client_thread(void *arg)
259 {
260 char *device = arg;
261 NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };
262 QIOChannelSocket *sioc;
263 int fd;
264 int ret;
265 pthread_t show_parts_thread;
266 Error *local_error = NULL;
267
268 sioc = qio_channel_socket_new();
269 if (qio_channel_socket_connect_sync(sioc,
270 saddr,
271 &local_error) < 0) {
272 error_report_err(local_error);
273 goto out;
274 }
275
276 ret = nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc),
277 NULL, NULL, NULL, &info, &local_error);
278 if (ret < 0) {
279 if (local_error) {
280 error_report_err(local_error);
281 }
282 goto out_socket;
283 }
284
285 fd = open(device, O_RDWR);
286 if (fd < 0) {
287 /* Linux-only, we can use %m in printf. */
288 error_report("Failed to open %s: %m", device);
289 goto out_socket;
290 }
291
292 ret = nbd_init(fd, sioc, &info, &local_error);
293 if (ret < 0) {
294 error_report_err(local_error);
295 goto out_fd;
296 }
297
298 /* update partition table */
299 pthread_create(&show_parts_thread, NULL, show_parts, device);
300
301 if (verbose) {
302 fprintf(stderr, "NBD device %s is now connected to %s\n",
303 device, srcpath);
304 } else {
305 /* Close stderr so that the qemu-nbd process exits. */
306 dup2(STDOUT_FILENO, STDERR_FILENO);
307 }
308
309 ret = nbd_client(fd);
310 if (ret) {
311 goto out_fd;
312 }
313 close(fd);
314 object_unref(OBJECT(sioc));
315 g_free(info.name);
316 kill(getpid(), SIGTERM);
317 return (void *) EXIT_SUCCESS;
318
319 out_fd:
320 close(fd);
321 out_socket:
322 object_unref(OBJECT(sioc));
323 out:
324 g_free(info.name);
325 kill(getpid(), SIGTERM);
326 return (void *) EXIT_FAILURE;
327 }
328 #endif /* HAVE_NBD_DEVICE */
329
330 static int nbd_can_accept(void)
331 {
332 return state == RUNNING && nb_fds < shared;
333 }
334
335 static void nbd_export_closed(NBDExport *export)
336 {
337 assert(state == TERMINATING);
338 state = TERMINATED;
339 }
340
341 static void nbd_update_server_watch(void);
342
343 static void nbd_client_closed(NBDClient *client, bool negotiated)
344 {
345 nb_fds--;
346 if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
347 state = TERMINATE;
348 }
349 nbd_update_server_watch();
350 nbd_client_put(client);
351 }
352
353 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
354 gpointer opaque)
355 {
356 if (state >= TERMINATE) {
357 return;
358 }
359
360 nb_fds++;
361 nbd_update_server_watch();
362 nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
363 }
364
365 static void nbd_update_server_watch(void)
366 {
367 if (nbd_can_accept()) {
368 qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
369 } else {
370 qio_net_listener_set_client_func(server, NULL, NULL, NULL);
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_TYPE_UNIX;
384 saddr->u.q_unix.path = g_strdup(sockpath);
385 } else {
386 InetSocketAddress *inet;
387 saddr->type = SOCKET_ADDRESS_TYPE_INET;
388 inet = &saddr->u.inet;
389 inet->host = g_strdup(bindto);
390 if (port) {
391 inet->port = g_strdup(port);
392 } else {
393 inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
394 }
395 }
396
397 return saddr;
398 }
399
400
401 static QemuOptsList file_opts = {
402 .name = "file",
403 .implied_opt_name = "file",
404 .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
405 .desc = {
406 /* no elements => accept any params */
407 { /* end of list */ }
408 },
409 };
410
411 static QemuOptsList qemu_object_opts = {
412 .name = "object",
413 .implied_opt_name = "qom-type",
414 .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
415 .desc = {
416 { }
417 },
418 };
419
420 static bool qemu_nbd_object_print_help(const char *type, QemuOpts *opts)
421 {
422 if (user_creatable_print_help(type, opts)) {
423 exit(0);
424 }
425 return true;
426 }
427
428
429 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
430 Error **errp)
431 {
432 Object *obj;
433 QCryptoTLSCreds *creds;
434
435 obj = object_resolve_path_component(
436 object_get_objects_root(), id);
437 if (!obj) {
438 error_setg(errp, "No TLS credentials with id '%s'",
439 id);
440 return NULL;
441 }
442 creds = (QCryptoTLSCreds *)
443 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
444 if (!creds) {
445 error_setg(errp, "Object with id '%s' is not TLS credentials",
446 id);
447 return NULL;
448 }
449
450 if (list) {
451 if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
452 error_setg(errp,
453 "Expecting TLS credentials with a client endpoint");
454 return NULL;
455 }
456 } else {
457 if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
458 error_setg(errp,
459 "Expecting TLS credentials with a server endpoint");
460 return NULL;
461 }
462 }
463 object_ref(obj);
464 return creds;
465 }
466
467 static void setup_address_and_port(const char **address, const char **port)
468 {
469 if (*address == NULL) {
470 *address = "0.0.0.0";
471 }
472
473 if (*port == NULL) {
474 *port = stringify(NBD_DEFAULT_PORT);
475 }
476 }
477
478 /*
479 * Check socket parameters compatibility when socket activation is used.
480 */
481 static const char *socket_activation_validate_opts(const char *device,
482 const char *sockpath,
483 const char *address,
484 const char *port,
485 bool list)
486 {
487 if (device != NULL) {
488 return "NBD device can't be set when using socket activation";
489 }
490
491 if (sockpath != NULL) {
492 return "Unix socket can't be set when using socket activation";
493 }
494
495 if (address != NULL) {
496 return "The interface can't be set when using socket activation";
497 }
498
499 if (port != NULL) {
500 return "TCP port number can't be set when using socket activation";
501 }
502
503 if (list) {
504 return "List mode is incompatible with socket activation";
505 }
506
507 return NULL;
508 }
509
510 static void qemu_nbd_shutdown(void)
511 {
512 job_cancel_sync_all();
513 bdrv_close_all();
514 }
515
516 int main(int argc, char **argv)
517 {
518 BlockBackend *blk;
519 BlockDriverState *bs;
520 uint64_t dev_offset = 0;
521 bool readonly = false;
522 bool disconnect = false;
523 const char *bindto = NULL;
524 const char *port = NULL;
525 char *sockpath = NULL;
526 char *device = NULL;
527 QemuOpts *sn_opts = NULL;
528 const char *sn_id_or_name = NULL;
529 const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:B:L";
530 struct option lopt[] = {
531 { "help", no_argument, NULL, 'h' },
532 { "version", no_argument, NULL, 'V' },
533 { "bind", required_argument, NULL, 'b' },
534 { "port", required_argument, NULL, 'p' },
535 { "socket", required_argument, NULL, 'k' },
536 { "offset", required_argument, NULL, 'o' },
537 { "read-only", no_argument, NULL, 'r' },
538 { "bitmap", required_argument, NULL, 'B' },
539 { "connect", required_argument, NULL, 'c' },
540 { "disconnect", no_argument, NULL, 'd' },
541 { "list", no_argument, NULL, 'L' },
542 { "snapshot", no_argument, NULL, 's' },
543 { "load-snapshot", required_argument, NULL, 'l' },
544 { "nocache", no_argument, NULL, 'n' },
545 { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
546 { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
547 { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
548 { "detect-zeroes", required_argument, NULL,
549 QEMU_NBD_OPT_DETECT_ZEROES },
550 { "shared", required_argument, NULL, 'e' },
551 { "format", required_argument, NULL, 'f' },
552 { "persistent", no_argument, NULL, 't' },
553 { "verbose", no_argument, NULL, 'v' },
554 { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
555 { "export-name", required_argument, NULL, 'x' },
556 { "description", required_argument, NULL, 'D' },
557 { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
558 { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
559 { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
560 { "trace", required_argument, NULL, 'T' },
561 { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
562 { "pid-file", required_argument, NULL, QEMU_NBD_OPT_PID_FILE },
563 { NULL, 0, NULL, 0 }
564 };
565 int ch;
566 int opt_ind = 0;
567 int flags = BDRV_O_RDWR;
568 int ret = 0;
569 bool seen_cache = false;
570 bool seen_discard = false;
571 bool seen_aio = false;
572 pthread_t client_thread;
573 const char *fmt = NULL;
574 Error *local_err = NULL;
575 BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
576 QDict *options = NULL;
577 const char *export_name = NULL; /* defaults to "" later for server mode */
578 const char *export_description = NULL;
579 const char *bitmap = NULL;
580 const char *tlscredsid = NULL;
581 bool imageOpts = false;
582 bool writethrough = true;
583 char *trace_file = NULL;
584 bool fork_process = false;
585 bool list = false;
586 int old_stderr = -1;
587 unsigned socket_activation;
588 const char *pid_file_name = NULL;
589
590 #if HAVE_NBD_DEVICE
591 /* The client thread uses SIGTERM to interrupt the server. A signal
592 * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
593 */
594 struct sigaction sa_sigterm;
595 memset(&sa_sigterm, 0, sizeof(sa_sigterm));
596 sa_sigterm.sa_handler = termsig_handler;
597 sigaction(SIGTERM, &sa_sigterm, NULL);
598 #endif /* HAVE_NBD_DEVICE */
599
600 #ifdef CONFIG_POSIX
601 signal(SIGPIPE, SIG_IGN);
602 #endif
603
604 socket_init();
605 error_init(argv[0]);
606 module_call_init(MODULE_INIT_TRACE);
607 qcrypto_init(&error_fatal);
608
609 module_call_init(MODULE_INIT_QOM);
610 qemu_add_opts(&qemu_object_opts);
611 qemu_add_opts(&qemu_trace_opts);
612 qemu_init_exec_dir(argv[0]);
613
614 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
615 switch (ch) {
616 case 's':
617 flags |= BDRV_O_SNAPSHOT;
618 break;
619 case 'n':
620 optarg = (char *) "none";
621 /* fallthrough */
622 case QEMU_NBD_OPT_CACHE:
623 if (seen_cache) {
624 error_report("-n and --cache can only be specified once");
625 exit(EXIT_FAILURE);
626 }
627 seen_cache = true;
628 if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
629 error_report("Invalid cache mode `%s'", optarg);
630 exit(EXIT_FAILURE);
631 }
632 break;
633 case QEMU_NBD_OPT_AIO:
634 if (seen_aio) {
635 error_report("--aio can only be specified once");
636 exit(EXIT_FAILURE);
637 }
638 seen_aio = true;
639 if (bdrv_parse_aio(optarg, &flags) < 0) {
640 error_report("Invalid aio mode '%s'", optarg);
641 exit(EXIT_FAILURE);
642 }
643 break;
644 case QEMU_NBD_OPT_DISCARD:
645 if (seen_discard) {
646 error_report("--discard can only be specified once");
647 exit(EXIT_FAILURE);
648 }
649 seen_discard = true;
650 if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
651 error_report("Invalid discard mode `%s'", optarg);
652 exit(EXIT_FAILURE);
653 }
654 break;
655 case QEMU_NBD_OPT_DETECT_ZEROES:
656 detect_zeroes =
657 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
658 optarg,
659 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
660 &local_err);
661 if (local_err) {
662 error_reportf_err(local_err,
663 "Failed to parse detect_zeroes mode: ");
664 exit(EXIT_FAILURE);
665 }
666 if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
667 !(flags & BDRV_O_UNMAP)) {
668 error_report("setting detect-zeroes to unmap is not allowed "
669 "without setting discard operation to unmap");
670 exit(EXIT_FAILURE);
671 }
672 break;
673 case 'b':
674 bindto = optarg;
675 break;
676 case 'p':
677 port = optarg;
678 break;
679 case 'o':
680 if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
681 error_report("Invalid offset '%s'", optarg);
682 exit(EXIT_FAILURE);
683 }
684 break;
685 case 'l':
686 if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
687 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
688 optarg, false);
689 if (!sn_opts) {
690 error_report("Failed in parsing snapshot param `%s'",
691 optarg);
692 exit(EXIT_FAILURE);
693 }
694 } else {
695 sn_id_or_name = optarg;
696 }
697 /* fall through */
698 case 'r':
699 readonly = true;
700 flags &= ~BDRV_O_RDWR;
701 break;
702 case 'B':
703 bitmap = optarg;
704 break;
705 case 'k':
706 sockpath = optarg;
707 if (sockpath[0] != '/') {
708 error_report("socket path must be absolute");
709 exit(EXIT_FAILURE);
710 }
711 break;
712 case 'd':
713 disconnect = true;
714 break;
715 case 'c':
716 device = optarg;
717 break;
718 case 'e':
719 if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
720 shared < 1) {
721 error_report("Invalid shared device number '%s'", optarg);
722 exit(EXIT_FAILURE);
723 }
724 break;
725 case 'f':
726 fmt = optarg;
727 break;
728 case 't':
729 persistent = 1;
730 break;
731 case 'x':
732 export_name = optarg;
733 if (strlen(export_name) > NBD_MAX_STRING_SIZE) {
734 error_report("export name '%s' too long", export_name);
735 exit(EXIT_FAILURE);
736 }
737 break;
738 case 'D':
739 export_description = optarg;
740 if (strlen(export_description) > NBD_MAX_STRING_SIZE) {
741 error_report("export description '%s' too long",
742 export_description);
743 exit(EXIT_FAILURE);
744 }
745 break;
746 case 'v':
747 verbose = 1;
748 break;
749 case 'V':
750 version(argv[0]);
751 exit(0);
752 break;
753 case 'h':
754 usage(argv[0]);
755 exit(0);
756 break;
757 case '?':
758 error_report("Try `%s --help' for more information.", argv[0]);
759 exit(EXIT_FAILURE);
760 case QEMU_NBD_OPT_OBJECT: {
761 QemuOpts *opts;
762 opts = qemu_opts_parse_noisily(&qemu_object_opts,
763 optarg, true);
764 if (!opts) {
765 exit(EXIT_FAILURE);
766 }
767 } break;
768 case QEMU_NBD_OPT_TLSCREDS:
769 tlscredsid = optarg;
770 break;
771 case QEMU_NBD_OPT_IMAGE_OPTS:
772 imageOpts = true;
773 break;
774 case 'T':
775 g_free(trace_file);
776 trace_file = trace_opt_parse(optarg);
777 break;
778 case QEMU_NBD_OPT_TLSAUTHZ:
779 tlsauthz = optarg;
780 break;
781 case QEMU_NBD_OPT_FORK:
782 fork_process = true;
783 break;
784 case 'L':
785 list = true;
786 break;
787 case QEMU_NBD_OPT_PID_FILE:
788 pid_file_name = optarg;
789 break;
790 }
791 }
792
793 if (list) {
794 if (argc != optind) {
795 error_report("List mode is incompatible with a file name");
796 exit(EXIT_FAILURE);
797 }
798 if (export_name || export_description || dev_offset ||
799 device || disconnect || fmt || sn_id_or_name || bitmap ||
800 seen_aio || seen_discard || seen_cache) {
801 error_report("List mode is incompatible with per-device settings");
802 exit(EXIT_FAILURE);
803 }
804 if (fork_process) {
805 error_report("List mode is incompatible with forking");
806 exit(EXIT_FAILURE);
807 }
808 } else if ((argc - optind) != 1) {
809 error_report("Invalid number of arguments");
810 error_printf("Try `%s --help' for more information.\n", argv[0]);
811 exit(EXIT_FAILURE);
812 } else if (!export_name) {
813 export_name = "";
814 }
815
816 qemu_opts_foreach(&qemu_object_opts,
817 user_creatable_add_opts_foreach,
818 qemu_nbd_object_print_help, &error_fatal);
819
820 if (!trace_init_backends()) {
821 exit(1);
822 }
823 trace_init_file(trace_file);
824 qemu_set_log(LOG_TRACE);
825
826 socket_activation = check_socket_activation();
827 if (socket_activation == 0) {
828 setup_address_and_port(&bindto, &port);
829 } else {
830 /* Using socket activation - check user didn't use -p etc. */
831 const char *err_msg = socket_activation_validate_opts(device, sockpath,
832 bindto, port,
833 list);
834 if (err_msg != NULL) {
835 error_report("%s", err_msg);
836 exit(EXIT_FAILURE);
837 }
838
839 /* qemu-nbd can only listen on a single socket. */
840 if (socket_activation > 1) {
841 error_report("qemu-nbd does not support socket activation with %s > 1",
842 "LISTEN_FDS");
843 exit(EXIT_FAILURE);
844 }
845 }
846
847 if (tlscredsid) {
848 if (sockpath) {
849 error_report("TLS is only supported with IPv4/IPv6");
850 exit(EXIT_FAILURE);
851 }
852 if (device) {
853 error_report("TLS is not supported with a host device");
854 exit(EXIT_FAILURE);
855 }
856 if (tlsauthz && list) {
857 error_report("TLS authorization is incompatible with export list");
858 exit(EXIT_FAILURE);
859 }
860 tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
861 if (local_err) {
862 error_reportf_err(local_err, "Failed to get TLS creds: ");
863 exit(EXIT_FAILURE);
864 }
865 } else {
866 if (tlsauthz) {
867 error_report("--tls-authz is not permitted without --tls-creds");
868 exit(EXIT_FAILURE);
869 }
870 }
871
872 if (list) {
873 saddr = nbd_build_socket_address(sockpath, bindto, port);
874 return qemu_nbd_client_list(saddr, tlscreds, bindto);
875 }
876
877 #if !HAVE_NBD_DEVICE
878 if (disconnect || device) {
879 error_report("Kernel /dev/nbdN support not available");
880 exit(EXIT_FAILURE);
881 }
882 #else /* HAVE_NBD_DEVICE */
883 if (disconnect) {
884 int nbdfd = open(argv[optind], O_RDWR);
885 if (nbdfd < 0) {
886 error_report("Cannot open %s: %s", argv[optind],
887 strerror(errno));
888 exit(EXIT_FAILURE);
889 }
890 nbd_disconnect(nbdfd);
891
892 close(nbdfd);
893
894 printf("%s disconnected\n", argv[optind]);
895
896 return 0;
897 }
898 #endif
899
900 if ((device && !verbose) || fork_process) {
901 #ifndef WIN32
902 int stderr_fd[2];
903 pid_t pid;
904 int ret;
905
906 if (qemu_pipe(stderr_fd) < 0) {
907 error_report("Error setting up communication pipe: %s",
908 strerror(errno));
909 exit(EXIT_FAILURE);
910 }
911
912 /* Now daemonize, but keep a communication channel open to
913 * print errors and exit with the proper status code.
914 */
915 pid = fork();
916 if (pid < 0) {
917 error_report("Failed to fork: %s", strerror(errno));
918 exit(EXIT_FAILURE);
919 } else if (pid == 0) {
920 close(stderr_fd[0]);
921
922 /* Remember parent's stderr if we will be restoring it. */
923 if (fork_process) {
924 old_stderr = dup(STDERR_FILENO);
925 }
926
927 ret = qemu_daemon(1, 0);
928
929 /* Temporarily redirect stderr to the parent's pipe... */
930 dup2(stderr_fd[1], STDERR_FILENO);
931 if (ret < 0) {
932 error_report("Failed to daemonize: %s", strerror(errno));
933 exit(EXIT_FAILURE);
934 }
935
936 /* ... close the descriptor we inherited and go on. */
937 close(stderr_fd[1]);
938 } else {
939 bool errors = false;
940 char *buf;
941
942 /* In the parent. Print error messages from the child until
943 * it closes the pipe.
944 */
945 close(stderr_fd[1]);
946 buf = g_malloc(1024);
947 while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
948 errors = true;
949 ret = qemu_write_full(STDERR_FILENO, buf, ret);
950 if (ret < 0) {
951 exit(EXIT_FAILURE);
952 }
953 }
954 if (ret < 0) {
955 error_report("Cannot read from daemon: %s",
956 strerror(errno));
957 exit(EXIT_FAILURE);
958 }
959
960 /* Usually the daemon should not print any message.
961 * Exit with zero status in that case.
962 */
963 exit(errors);
964 }
965 #else /* WIN32 */
966 error_report("Unable to fork into background on Windows hosts");
967 exit(EXIT_FAILURE);
968 #endif /* WIN32 */
969 }
970
971 if (device != NULL && sockpath == NULL) {
972 sockpath = g_malloc(128);
973 snprintf(sockpath, 128, SOCKET_PATH, basename(device));
974 }
975
976 server = qio_net_listener_new();
977 if (socket_activation == 0) {
978 saddr = nbd_build_socket_address(sockpath, bindto, port);
979 if (qio_net_listener_open_sync(server, saddr, 1, &local_err) < 0) {
980 object_unref(OBJECT(server));
981 error_report_err(local_err);
982 exit(EXIT_FAILURE);
983 }
984 } else {
985 size_t i;
986 /* See comment in check_socket_activation above. */
987 for (i = 0; i < socket_activation; i++) {
988 QIOChannelSocket *sioc;
989 sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
990 &local_err);
991 if (sioc == NULL) {
992 object_unref(OBJECT(server));
993 error_reportf_err(local_err,
994 "Failed to use socket activation: ");
995 exit(EXIT_FAILURE);
996 }
997 qio_net_listener_add(server, sioc);
998 object_unref(OBJECT(sioc));
999 }
1000 }
1001
1002 if (qemu_init_main_loop(&local_err)) {
1003 error_report_err(local_err);
1004 exit(EXIT_FAILURE);
1005 }
1006 bdrv_init();
1007 atexit(qemu_nbd_shutdown);
1008
1009 srcpath = argv[optind];
1010 if (imageOpts) {
1011 QemuOpts *opts;
1012 if (fmt) {
1013 error_report("--image-opts and -f are mutually exclusive");
1014 exit(EXIT_FAILURE);
1015 }
1016 opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
1017 if (!opts) {
1018 qemu_opts_reset(&file_opts);
1019 exit(EXIT_FAILURE);
1020 }
1021 options = qemu_opts_to_qdict(opts, NULL);
1022 qemu_opts_reset(&file_opts);
1023 blk = blk_new_open(NULL, NULL, options, flags, &local_err);
1024 } else {
1025 if (fmt) {
1026 options = qdict_new();
1027 qdict_put_str(options, "driver", fmt);
1028 }
1029 blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
1030 }
1031
1032 if (!blk) {
1033 error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
1034 argv[optind]);
1035 exit(EXIT_FAILURE);
1036 }
1037 bs = blk_bs(blk);
1038
1039 if (dev_offset) {
1040 QDict *raw_opts = qdict_new();
1041 qdict_put_str(raw_opts, "driver", "raw");
1042 qdict_put_str(raw_opts, "file", bs->node_name);
1043 qdict_put_int(raw_opts, "offset", dev_offset);
1044 bs = bdrv_open(NULL, NULL, raw_opts, flags, &error_fatal);
1045 blk_remove_bs(blk);
1046 blk_insert_bs(blk, bs, &error_fatal);
1047 bdrv_unref(bs);
1048 }
1049
1050 blk_set_enable_write_cache(blk, !writethrough);
1051
1052 if (sn_opts) {
1053 ret = bdrv_snapshot_load_tmp(bs,
1054 qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1055 qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1056 &local_err);
1057 } else if (sn_id_or_name) {
1058 ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1059 &local_err);
1060 }
1061 if (ret < 0) {
1062 error_reportf_err(local_err, "Failed to load snapshot: ");
1063 exit(EXIT_FAILURE);
1064 }
1065
1066 bs->detect_zeroes = detect_zeroes;
1067
1068 export = nbd_export_new(bs, export_name,
1069 export_description, bitmap, readonly, shared > 1,
1070 nbd_export_closed, writethrough, &error_fatal);
1071
1072 if (device) {
1073 #if HAVE_NBD_DEVICE
1074 int ret;
1075
1076 ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
1077 if (ret != 0) {
1078 error_report("Failed to create client thread: %s", strerror(ret));
1079 exit(EXIT_FAILURE);
1080 }
1081 #endif
1082 } else {
1083 /* Shut up GCC warnings. */
1084 memset(&client_thread, 0, sizeof(client_thread));
1085 }
1086
1087 nbd_update_server_watch();
1088
1089 if (pid_file_name) {
1090 qemu_write_pidfile(pid_file_name, &error_fatal);
1091 }
1092
1093 /* now when the initialization is (almost) complete, chdir("/")
1094 * to free any busy filesystems */
1095 if (chdir("/") < 0) {
1096 error_report("Could not chdir to root directory: %s",
1097 strerror(errno));
1098 exit(EXIT_FAILURE);
1099 }
1100
1101 if (fork_process) {
1102 dup2(old_stderr, STDERR_FILENO);
1103 close(old_stderr);
1104 }
1105
1106 state = RUNNING;
1107 do {
1108 main_loop_wait(false);
1109 if (state == TERMINATE) {
1110 state = TERMINATING;
1111 nbd_export_close(export);
1112 nbd_export_put(export);
1113 export = NULL;
1114 }
1115 } while (state != TERMINATED);
1116
1117 blk_unref(blk);
1118 if (sockpath) {
1119 unlink(sockpath);
1120 }
1121
1122 qemu_opts_del(sn_opts);
1123
1124 if (device) {
1125 void *ret;
1126 pthread_join(client_thread, &ret);
1127 exit(ret != NULL);
1128 } else {
1129 exit(EXIT_SUCCESS);
1130 }
1131 }