xref: /openbmc/qemu/qemu-nbd.c (revision 40f23e4e)
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 "sysemu/runstate.h" /* for qemu_system_killed() prototype */
29 #include "block/block_int.h"
30 #include "block/nbd.h"
31 #include "qemu/main-loop.h"
32 #include "qemu/module.h"
33 #include "qemu/option.h"
34 #include "qemu/error-report.h"
35 #include "qemu/config-file.h"
36 #include "qemu/bswap.h"
37 #include "qemu/log.h"
38 #include "qemu/systemd.h"
39 #include "block/snapshot.h"
40 #include "qapi/qmp/qdict.h"
41 #include "qapi/qmp/qstring.h"
42 #include "qom/object_interfaces.h"
43 #include "io/channel-socket.h"
44 #include "io/net-listener.h"
45 #include "crypto/init.h"
46 #include "crypto/tlscreds.h"
47 #include "trace/control.h"
48 #include "qemu-version.h"
49 
50 #ifdef __linux__
51 #define HAVE_NBD_DEVICE 1
52 #else
53 #define HAVE_NBD_DEVICE 0
54 #endif
55 
56 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
57 #define QEMU_NBD_OPT_CACHE         256
58 #define QEMU_NBD_OPT_AIO           257
59 #define QEMU_NBD_OPT_DISCARD       258
60 #define QEMU_NBD_OPT_DETECT_ZEROES 259
61 #define QEMU_NBD_OPT_OBJECT        260
62 #define QEMU_NBD_OPT_TLSCREDS      261
63 #define QEMU_NBD_OPT_IMAGE_OPTS    262
64 #define QEMU_NBD_OPT_FORK          263
65 #define QEMU_NBD_OPT_TLSAUTHZ      264
66 #define QEMU_NBD_OPT_PID_FILE      265
67 
68 #define MBR_SIZE 512
69 
70 static int verbose;
71 static char *srcpath;
72 static SocketAddress *saddr;
73 static int persistent = 0;
74 static enum { RUNNING, TERMINATE, TERMINATED } state;
75 static int shared = 1;
76 static int nb_fds;
77 static QIONetListener *server;
78 static QCryptoTLSCreds *tlscreds;
79 static const char *tlsauthz;
80 
81 static void usage(const char *name)
82 {
83     (printf) (
84 "Usage: %s [OPTIONS] FILE\n"
85 "  or:  %s -L [OPTIONS]\n"
86 "QEMU Disk Network Block Device Utility\n"
87 "\n"
88 "  -h, --help                display this help and exit\n"
89 "  -V, --version             output version information and exit\n"
90 "\n"
91 "Connection properties:\n"
92 "  -p, --port=PORT           port to listen on (default `%d')\n"
93 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
94 "  -k, --socket=PATH         path to the unix socket\n"
95 "                            (default '"SOCKET_PATH"')\n"
96 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
97 "  -t, --persistent          don't exit on the last connection\n"
98 "  -v, --verbose             display extra debugging information\n"
99 "  -x, --export-name=NAME    expose export by name (default is empty string)\n"
100 "  -D, --description=TEXT    export a human-readable description\n"
101 "\n"
102 "Exposing part of the image:\n"
103 "  -o, --offset=OFFSET       offset into the image\n"
104 "  -A, --allocation-depth    expose the allocation depth\n"
105 "  -B, --bitmap=NAME         expose a persistent dirty bitmap\n"
106 "\n"
107 "General purpose options:\n"
108 "  -L, --list                list exports available from another NBD server\n"
109 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
110 "                            passwords and/or encryption keys\n"
111 "  --tls-creds=ID            use id of an earlier --object to provide TLS\n"
112 "  --tls-authz=ID            use id of an earlier --object to provide\n"
113 "                            authorization\n"
114 "  -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
115 "                            specify tracing options\n"
116 "  --fork                    fork off the server process and exit the parent\n"
117 "                            once the server is running\n"
118 "  --pid-file=PATH           store the server's process ID in the given file\n"
119 #if HAVE_NBD_DEVICE
120 "\n"
121 "Kernel NBD client support:\n"
122 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
123 "  -d, --disconnect          disconnect the specified device\n"
124 #endif
125 "\n"
126 "Block device options:\n"
127 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
128 "  -r, --read-only           export read-only\n"
129 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
130 "                            file with backing_file=FILE, redirect the write to\n"
131 "                            the temporary one\n"
132 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
133 "                            load an internal snapshot inside FILE and export it\n"
134 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
135 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
136 "                            '[ID_OR_NAME]'\n"
137 "  -n, --nocache             disable host cache\n"
138 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
139 "      --aio=MODE            set AIO mode (native, io_uring or threads)\n"
140 "      --discard=MODE        set discard mode (ignore, unmap)\n"
141 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
142 "      --image-opts          treat FILE as a full set of image options\n"
143 "\n"
144 QEMU_HELP_BOTTOM "\n"
145     , name, name, NBD_DEFAULT_PORT, "DEVICE");
146 }
147 
148 static void version(const char *name)
149 {
150     printf(
151 "%s " QEMU_FULL_VERSION "\n"
152 "Written by Anthony Liguori.\n"
153 "\n"
154 QEMU_COPYRIGHT "\n"
155 "This is free software; see the source for copying conditions.  There is NO\n"
156 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
157     , name);
158 }
159 
160 #ifdef CONFIG_POSIX
161 /*
162  * The client thread uses SIGTERM to interrupt the server.  A signal
163  * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
164  */
165 void qemu_system_killed(int signum, pid_t pid)
166 {
167     qatomic_cmpxchg(&state, RUNNING, TERMINATE);
168     qemu_notify_event();
169 }
170 #endif /* CONFIG_POSIX */
171 
172 static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
173                                 const char *hostname)
174 {
175     int ret = EXIT_FAILURE;
176     int rc;
177     Error *err = NULL;
178     QIOChannelSocket *sioc;
179     NBDExportInfo *list;
180     int i, j;
181 
182     sioc = qio_channel_socket_new();
183     if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
184         error_report_err(err);
185         goto out;
186     }
187     rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
188                                  &err);
189     if (rc < 0) {
190         if (err) {
191             error_report_err(err);
192         }
193         goto out;
194     }
195     printf("exports available: %d\n", rc);
196     for (i = 0; i < rc; i++) {
197         printf(" export: '%s'\n", list[i].name);
198         if (list[i].description && *list[i].description) {
199             printf("  description: %s\n", list[i].description);
200         }
201         if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
202             static const char *const flag_names[] = {
203                 [NBD_FLAG_READ_ONLY_BIT]            = "readonly",
204                 [NBD_FLAG_SEND_FLUSH_BIT]           = "flush",
205                 [NBD_FLAG_SEND_FUA_BIT]             = "fua",
206                 [NBD_FLAG_ROTATIONAL_BIT]           = "rotational",
207                 [NBD_FLAG_SEND_TRIM_BIT]            = "trim",
208                 [NBD_FLAG_SEND_WRITE_ZEROES_BIT]    = "zeroes",
209                 [NBD_FLAG_SEND_DF_BIT]              = "df",
210                 [NBD_FLAG_CAN_MULTI_CONN_BIT]       = "multi",
211                 [NBD_FLAG_SEND_RESIZE_BIT]          = "resize",
212                 [NBD_FLAG_SEND_CACHE_BIT]           = "cache",
213                 [NBD_FLAG_SEND_FAST_ZERO_BIT]       = "fast-zero",
214             };
215 
216             printf("  size:  %" PRIu64 "\n", list[i].size);
217             printf("  flags: 0x%x (", list[i].flags);
218             for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) {
219                 if (flag_names[bit] && (list[i].flags & (1 << bit))) {
220                     printf(" %s", flag_names[bit]);
221                 }
222             }
223             printf(" )\n");
224         }
225         if (list[i].min_block) {
226             printf("  min block: %u\n", list[i].min_block);
227             printf("  opt block: %u\n", list[i].opt_block);
228             printf("  max block: %u\n", list[i].max_block);
229         }
230         if (list[i].n_contexts) {
231             printf("  available meta contexts: %d\n", list[i].n_contexts);
232             for (j = 0; j < list[i].n_contexts; j++) {
233                 printf("   %s\n", list[i].contexts[j]);
234             }
235         }
236     }
237     nbd_free_export_list(list, rc);
238 
239     ret = EXIT_SUCCESS;
240  out:
241     object_unref(OBJECT(sioc));
242     return ret;
243 }
244 
245 
246 #if HAVE_NBD_DEVICE
247 static void *show_parts(void *arg)
248 {
249     char *device = arg;
250     int nbd;
251 
252     /* linux just needs an open() to trigger
253      * the partition table update
254      * but remember to load the module with max_part != 0 :
255      *     modprobe nbd max_part=63
256      */
257     nbd = open(device, O_RDWR);
258     if (nbd >= 0) {
259         close(nbd);
260     }
261     return NULL;
262 }
263 
264 static void *nbd_client_thread(void *arg)
265 {
266     char *device = arg;
267     NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };
268     QIOChannelSocket *sioc;
269     int fd = -1;
270     int ret = EXIT_FAILURE;
271     pthread_t show_parts_thread;
272     Error *local_error = NULL;
273 
274     sioc = qio_channel_socket_new();
275     if (qio_channel_socket_connect_sync(sioc,
276                                         saddr,
277                                         &local_error) < 0) {
278         error_report_err(local_error);
279         goto out;
280     }
281 
282     if (nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc),
283                               NULL, NULL, NULL, &info, &local_error) < 0) {
284         if (local_error) {
285             error_report_err(local_error);
286         }
287         goto out;
288     }
289 
290     fd = open(device, O_RDWR);
291     if (fd < 0) {
292         /* Linux-only, we can use %m in printf.  */
293         error_report("Failed to open %s: %m", device);
294         goto out;
295     }
296 
297     if (nbd_init(fd, sioc, &info, &local_error) < 0) {
298         error_report_err(local_error);
299         goto out;
300     }
301 
302     /* update partition table */
303     pthread_create(&show_parts_thread, NULL, show_parts, device);
304 
305     if (verbose) {
306         fprintf(stderr, "NBD device %s is now connected to %s\n",
307                 device, srcpath);
308     } else {
309         /* Close stderr so that the qemu-nbd process exits.  */
310         dup2(STDOUT_FILENO, STDERR_FILENO);
311     }
312 
313     if (nbd_client(fd) < 0) {
314         goto out;
315     }
316 
317     ret = EXIT_SUCCESS;
318 
319  out:
320     if (fd >= 0) {
321         close(fd);
322     }
323     object_unref(OBJECT(sioc));
324     g_free(info.name);
325     kill(getpid(), SIGTERM);
326     return (void *) (intptr_t) ret;
327 }
328 #endif /* HAVE_NBD_DEVICE */
329 
330 static int nbd_can_accept(void)
331 {
332     return state == RUNNING && (shared == 0 || nb_fds < shared);
333 }
334 
335 static void nbd_update_server_watch(void);
336 
337 static void nbd_client_closed(NBDClient *client, bool negotiated)
338 {
339     nb_fds--;
340     if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
341         state = TERMINATE;
342     }
343     nbd_update_server_watch();
344     nbd_client_put(client);
345 }
346 
347 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
348                        gpointer opaque)
349 {
350     if (state >= TERMINATE) {
351         return;
352     }
353 
354     nb_fds++;
355     nbd_update_server_watch();
356     nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
357 }
358 
359 static void nbd_update_server_watch(void)
360 {
361     if (nbd_can_accept()) {
362         qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
363     } else {
364         qio_net_listener_set_client_func(server, NULL, NULL, NULL);
365     }
366 }
367 
368 
369 static SocketAddress *nbd_build_socket_address(const char *sockpath,
370                                                const char *bindto,
371                                                const char *port)
372 {
373     SocketAddress *saddr;
374 
375     saddr = g_new0(SocketAddress, 1);
376     if (sockpath) {
377         saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
378         saddr->u.q_unix.path = g_strdup(sockpath);
379     } else {
380         InetSocketAddress *inet;
381         saddr->type = SOCKET_ADDRESS_TYPE_INET;
382         inet = &saddr->u.inet;
383         inet->host = g_strdup(bindto);
384         if (port) {
385             inet->port = g_strdup(port);
386         } else  {
387             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
388         }
389     }
390 
391     return saddr;
392 }
393 
394 
395 static QemuOptsList file_opts = {
396     .name = "file",
397     .implied_opt_name = "file",
398     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
399     .desc = {
400         /* no elements => accept any params */
401         { /* end of list */ }
402     },
403 };
404 
405 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
406                                           Error **errp)
407 {
408     Object *obj;
409     QCryptoTLSCreds *creds;
410 
411     obj = object_resolve_path_component(
412         object_get_objects_root(), id);
413     if (!obj) {
414         error_setg(errp, "No TLS credentials with id '%s'",
415                    id);
416         return NULL;
417     }
418     creds = (QCryptoTLSCreds *)
419         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
420     if (!creds) {
421         error_setg(errp, "Object with id '%s' is not TLS credentials",
422                    id);
423         return NULL;
424     }
425 
426     if (!qcrypto_tls_creds_check_endpoint(creds,
427                                           list
428                                           ? QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT
429                                           : QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
430                                           errp)) {
431         return NULL;
432     }
433     object_ref(obj);
434     return creds;
435 }
436 
437 static void setup_address_and_port(const char **address, const char **port)
438 {
439     if (*address == NULL) {
440         *address = "0.0.0.0";
441     }
442 
443     if (*port == NULL) {
444         *port = stringify(NBD_DEFAULT_PORT);
445     }
446 }
447 
448 /*
449  * Check socket parameters compatibility when socket activation is used.
450  */
451 static const char *socket_activation_validate_opts(const char *device,
452                                                    const char *sockpath,
453                                                    const char *address,
454                                                    const char *port,
455                                                    bool list)
456 {
457     if (device != NULL) {
458         return "NBD device can't be set when using socket activation";
459     }
460 
461     if (sockpath != NULL) {
462         return "Unix socket can't be set when using socket activation";
463     }
464 
465     if (address != NULL) {
466         return "The interface can't be set when using socket activation";
467     }
468 
469     if (port != NULL) {
470         return "TCP port number can't be set when using socket activation";
471     }
472 
473     if (list) {
474         return "List mode is incompatible with socket activation";
475     }
476 
477     return NULL;
478 }
479 
480 static void qemu_nbd_shutdown(void)
481 {
482     job_cancel_sync_all();
483     blk_exp_close_all();
484     bdrv_close_all();
485 }
486 
487 int main(int argc, char **argv)
488 {
489     BlockBackend *blk;
490     BlockDriverState *bs;
491     uint64_t dev_offset = 0;
492     bool readonly = false;
493     bool disconnect = false;
494     const char *bindto = NULL;
495     const char *port = NULL;
496     char *sockpath = NULL;
497     char *device = NULL;
498     QemuOpts *sn_opts = NULL;
499     const char *sn_id_or_name = NULL;
500     const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:AB:L";
501     struct option lopt[] = {
502         { "help", no_argument, NULL, 'h' },
503         { "version", no_argument, NULL, 'V' },
504         { "bind", required_argument, NULL, 'b' },
505         { "port", required_argument, NULL, 'p' },
506         { "socket", required_argument, NULL, 'k' },
507         { "offset", required_argument, NULL, 'o' },
508         { "read-only", no_argument, NULL, 'r' },
509         { "allocation-depth", no_argument, NULL, 'A' },
510         { "bitmap", required_argument, NULL, 'B' },
511         { "connect", required_argument, NULL, 'c' },
512         { "disconnect", no_argument, NULL, 'd' },
513         { "list", no_argument, NULL, 'L' },
514         { "snapshot", no_argument, NULL, 's' },
515         { "load-snapshot", required_argument, NULL, 'l' },
516         { "nocache", no_argument, NULL, 'n' },
517         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
518         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
519         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
520         { "detect-zeroes", required_argument, NULL,
521           QEMU_NBD_OPT_DETECT_ZEROES },
522         { "shared", required_argument, NULL, 'e' },
523         { "format", required_argument, NULL, 'f' },
524         { "persistent", no_argument, NULL, 't' },
525         { "verbose", no_argument, NULL, 'v' },
526         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
527         { "export-name", required_argument, NULL, 'x' },
528         { "description", required_argument, NULL, 'D' },
529         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
530         { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
531         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
532         { "trace", required_argument, NULL, 'T' },
533         { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
534         { "pid-file", required_argument, NULL, QEMU_NBD_OPT_PID_FILE },
535         { NULL, 0, NULL, 0 }
536     };
537     int ch;
538     int opt_ind = 0;
539     int flags = BDRV_O_RDWR;
540     int ret = 0;
541     bool seen_cache = false;
542     bool seen_discard = false;
543     bool seen_aio = false;
544     pthread_t client_thread;
545     const char *fmt = NULL;
546     Error *local_err = NULL;
547     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
548     QDict *options = NULL;
549     const char *export_name = NULL; /* defaults to "" later for server mode */
550     const char *export_description = NULL;
551     strList *bitmaps = NULL;
552     bool alloc_depth = false;
553     const char *tlscredsid = NULL;
554     bool imageOpts = false;
555     bool writethrough = true;
556     bool fork_process = false;
557     bool list = false;
558     int old_stderr = -1;
559     unsigned socket_activation;
560     const char *pid_file_name = NULL;
561     BlockExportOptions *export_opts;
562 
563 #ifdef CONFIG_POSIX
564     os_setup_early_signal_handling();
565     os_setup_signal_handling();
566 #endif
567 
568     socket_init();
569     error_init(argv[0]);
570     module_call_init(MODULE_INIT_TRACE);
571     qcrypto_init(&error_fatal);
572 
573     module_call_init(MODULE_INIT_QOM);
574     qemu_add_opts(&qemu_trace_opts);
575     qemu_init_exec_dir(argv[0]);
576 
577     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
578         switch (ch) {
579         case 's':
580             flags |= BDRV_O_SNAPSHOT;
581             break;
582         case 'n':
583             optarg = (char *) "none";
584             /* fallthrough */
585         case QEMU_NBD_OPT_CACHE:
586             if (seen_cache) {
587                 error_report("-n and --cache can only be specified once");
588                 exit(EXIT_FAILURE);
589             }
590             seen_cache = true;
591             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
592                 error_report("Invalid cache mode `%s'", optarg);
593                 exit(EXIT_FAILURE);
594             }
595             break;
596         case QEMU_NBD_OPT_AIO:
597             if (seen_aio) {
598                 error_report("--aio can only be specified once");
599                 exit(EXIT_FAILURE);
600             }
601             seen_aio = true;
602             if (bdrv_parse_aio(optarg, &flags) < 0) {
603                 error_report("Invalid aio mode '%s'", optarg);
604                 exit(EXIT_FAILURE);
605             }
606             break;
607         case QEMU_NBD_OPT_DISCARD:
608             if (seen_discard) {
609                 error_report("--discard can only be specified once");
610                 exit(EXIT_FAILURE);
611             }
612             seen_discard = true;
613             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
614                 error_report("Invalid discard mode `%s'", optarg);
615                 exit(EXIT_FAILURE);
616             }
617             break;
618         case QEMU_NBD_OPT_DETECT_ZEROES:
619             detect_zeroes =
620                 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
621                                 optarg,
622                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
623                                 &local_err);
624             if (local_err) {
625                 error_reportf_err(local_err,
626                                   "Failed to parse detect_zeroes mode: ");
627                 exit(EXIT_FAILURE);
628             }
629             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
630                 !(flags & BDRV_O_UNMAP)) {
631                 error_report("setting detect-zeroes to unmap is not allowed "
632                              "without setting discard operation to unmap");
633                 exit(EXIT_FAILURE);
634             }
635             break;
636         case 'b':
637             bindto = optarg;
638             break;
639         case 'p':
640             port = optarg;
641             break;
642         case 'o':
643             if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
644                 error_report("Invalid offset '%s'", optarg);
645                 exit(EXIT_FAILURE);
646             }
647             break;
648         case 'l':
649             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
650                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
651                                                   optarg, false);
652                 if (!sn_opts) {
653                     error_report("Failed in parsing snapshot param `%s'",
654                                  optarg);
655                     exit(EXIT_FAILURE);
656                 }
657             } else {
658                 sn_id_or_name = optarg;
659             }
660             /* fall through */
661         case 'r':
662             readonly = true;
663             flags &= ~BDRV_O_RDWR;
664             break;
665         case 'A':
666             alloc_depth = true;
667             break;
668         case 'B':
669             QAPI_LIST_PREPEND(bitmaps, g_strdup(optarg));
670             break;
671         case 'k':
672             sockpath = optarg;
673             if (sockpath[0] != '/') {
674                 error_report("socket path must be absolute");
675                 exit(EXIT_FAILURE);
676             }
677             break;
678         case 'd':
679             disconnect = true;
680             break;
681         case 'c':
682             device = optarg;
683             break;
684         case 'e':
685             if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
686                 shared < 0) {
687                 error_report("Invalid shared device number '%s'", optarg);
688                 exit(EXIT_FAILURE);
689             }
690             break;
691         case 'f':
692             fmt = optarg;
693             break;
694         case 't':
695             persistent = 1;
696             break;
697         case 'x':
698             export_name = optarg;
699             if (strlen(export_name) > NBD_MAX_STRING_SIZE) {
700                 error_report("export name '%s' too long", export_name);
701                 exit(EXIT_FAILURE);
702             }
703             break;
704         case 'D':
705             export_description = optarg;
706             if (strlen(export_description) > NBD_MAX_STRING_SIZE) {
707                 error_report("export description '%s' too long",
708                              export_description);
709                 exit(EXIT_FAILURE);
710             }
711             break;
712         case 'v':
713             verbose = 1;
714             break;
715         case 'V':
716             version(argv[0]);
717             exit(0);
718             break;
719         case 'h':
720             usage(argv[0]);
721             exit(0);
722             break;
723         case '?':
724             error_report("Try `%s --help' for more information.", argv[0]);
725             exit(EXIT_FAILURE);
726         case QEMU_NBD_OPT_OBJECT:
727             user_creatable_process_cmdline(optarg);
728             break;
729         case QEMU_NBD_OPT_TLSCREDS:
730             tlscredsid = optarg;
731             break;
732         case QEMU_NBD_OPT_IMAGE_OPTS:
733             imageOpts = true;
734             break;
735         case 'T':
736             trace_opt_parse(optarg);
737             break;
738         case QEMU_NBD_OPT_TLSAUTHZ:
739             tlsauthz = optarg;
740             break;
741         case QEMU_NBD_OPT_FORK:
742             fork_process = true;
743             break;
744         case 'L':
745             list = true;
746             break;
747         case QEMU_NBD_OPT_PID_FILE:
748             pid_file_name = optarg;
749             break;
750         }
751     }
752 
753     if (list) {
754         if (argc != optind) {
755             error_report("List mode is incompatible with a file name");
756             exit(EXIT_FAILURE);
757         }
758         if (export_name || export_description || dev_offset ||
759             device || disconnect || fmt || sn_id_or_name || bitmaps ||
760             alloc_depth || seen_aio || seen_discard || seen_cache) {
761             error_report("List mode is incompatible with per-device settings");
762             exit(EXIT_FAILURE);
763         }
764         if (fork_process) {
765             error_report("List mode is incompatible with forking");
766             exit(EXIT_FAILURE);
767         }
768     } else if ((argc - optind) != 1) {
769         error_report("Invalid number of arguments");
770         error_printf("Try `%s --help' for more information.\n", argv[0]);
771         exit(EXIT_FAILURE);
772     } else if (!export_name) {
773         export_name = "";
774     }
775 
776     if (!trace_init_backends()) {
777         exit(1);
778     }
779     trace_init_file();
780     qemu_set_log(LOG_TRACE);
781 
782     socket_activation = check_socket_activation();
783     if (socket_activation == 0) {
784         setup_address_and_port(&bindto, &port);
785     } else {
786         /* Using socket activation - check user didn't use -p etc. */
787         const char *err_msg = socket_activation_validate_opts(device, sockpath,
788                                                               bindto, port,
789                                                               list);
790         if (err_msg != NULL) {
791             error_report("%s", err_msg);
792             exit(EXIT_FAILURE);
793         }
794 
795         /* qemu-nbd can only listen on a single socket.  */
796         if (socket_activation > 1) {
797             error_report("qemu-nbd does not support socket activation with %s > 1",
798                          "LISTEN_FDS");
799             exit(EXIT_FAILURE);
800         }
801     }
802 
803     if (tlscredsid) {
804         if (sockpath) {
805             error_report("TLS is only supported with IPv4/IPv6");
806             exit(EXIT_FAILURE);
807         }
808         if (device) {
809             error_report("TLS is not supported with a host device");
810             exit(EXIT_FAILURE);
811         }
812         if (tlsauthz && list) {
813             error_report("TLS authorization is incompatible with export list");
814             exit(EXIT_FAILURE);
815         }
816         tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
817         if (local_err) {
818             error_reportf_err(local_err, "Failed to get TLS creds: ");
819             exit(EXIT_FAILURE);
820         }
821     } else {
822         if (tlsauthz) {
823             error_report("--tls-authz is not permitted without --tls-creds");
824             exit(EXIT_FAILURE);
825         }
826     }
827 
828     if (list) {
829         saddr = nbd_build_socket_address(sockpath, bindto, port);
830         return qemu_nbd_client_list(saddr, tlscreds, bindto);
831     }
832 
833 #if !HAVE_NBD_DEVICE
834     if (disconnect || device) {
835         error_report("Kernel /dev/nbdN support not available");
836         exit(EXIT_FAILURE);
837     }
838 #else /* HAVE_NBD_DEVICE */
839     if (disconnect) {
840         int nbdfd = open(argv[optind], O_RDWR);
841         if (nbdfd < 0) {
842             error_report("Cannot open %s: %s", argv[optind],
843                          strerror(errno));
844             exit(EXIT_FAILURE);
845         }
846         nbd_disconnect(nbdfd);
847 
848         close(nbdfd);
849 
850         printf("%s disconnected\n", argv[optind]);
851 
852         return 0;
853     }
854 #endif
855 
856     if ((device && !verbose) || fork_process) {
857 #ifndef WIN32
858         int stderr_fd[2];
859         pid_t pid;
860         int ret;
861 
862         if (qemu_pipe(stderr_fd) < 0) {
863             error_report("Error setting up communication pipe: %s",
864                          strerror(errno));
865             exit(EXIT_FAILURE);
866         }
867 
868         /* Now daemonize, but keep a communication channel open to
869          * print errors and exit with the proper status code.
870          */
871         pid = fork();
872         if (pid < 0) {
873             error_report("Failed to fork: %s", strerror(errno));
874             exit(EXIT_FAILURE);
875         } else if (pid == 0) {
876             close(stderr_fd[0]);
877 
878             /* Remember parent's stderr if we will be restoring it. */
879             if (fork_process) {
880                 old_stderr = dup(STDERR_FILENO);
881             }
882 
883             ret = qemu_daemon(1, 0);
884 
885             /* Temporarily redirect stderr to the parent's pipe...  */
886             dup2(stderr_fd[1], STDERR_FILENO);
887             if (ret < 0) {
888                 error_report("Failed to daemonize: %s", strerror(errno));
889                 exit(EXIT_FAILURE);
890             }
891 
892             /* ... close the descriptor we inherited and go on.  */
893             close(stderr_fd[1]);
894         } else {
895             bool errors = false;
896             char *buf;
897 
898             /* In the parent.  Print error messages from the child until
899              * it closes the pipe.
900              */
901             close(stderr_fd[1]);
902             buf = g_malloc(1024);
903             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
904                 errors = true;
905                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
906                 if (ret < 0) {
907                     exit(EXIT_FAILURE);
908                 }
909             }
910             if (ret < 0) {
911                 error_report("Cannot read from daemon: %s",
912                              strerror(errno));
913                 exit(EXIT_FAILURE);
914             }
915 
916             /* Usually the daemon should not print any message.
917              * Exit with zero status in that case.
918              */
919             exit(errors);
920         }
921 #else /* WIN32 */
922         error_report("Unable to fork into background on Windows hosts");
923         exit(EXIT_FAILURE);
924 #endif /* WIN32 */
925     }
926 
927     if (device != NULL && sockpath == NULL) {
928         sockpath = g_malloc(128);
929         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
930     }
931 
932     server = qio_net_listener_new();
933     if (socket_activation == 0) {
934         int backlog;
935 
936         if (persistent || shared == 0) {
937             backlog = SOMAXCONN;
938         } else {
939             backlog = MIN(shared, SOMAXCONN);
940         }
941         saddr = nbd_build_socket_address(sockpath, bindto, port);
942         if (qio_net_listener_open_sync(server, saddr, backlog,
943                                        &local_err) < 0) {
944             object_unref(OBJECT(server));
945             error_report_err(local_err);
946             exit(EXIT_FAILURE);
947         }
948     } else {
949         size_t i;
950         /* See comment in check_socket_activation above. */
951         for (i = 0; i < socket_activation; i++) {
952             QIOChannelSocket *sioc;
953             sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
954                                              &local_err);
955             if (sioc == NULL) {
956                 object_unref(OBJECT(server));
957                 error_reportf_err(local_err,
958                                   "Failed to use socket activation: ");
959                 exit(EXIT_FAILURE);
960             }
961             qio_net_listener_add(server, sioc);
962             object_unref(OBJECT(sioc));
963         }
964     }
965 
966     if (qemu_init_main_loop(&local_err)) {
967         error_report_err(local_err);
968         exit(EXIT_FAILURE);
969     }
970     bdrv_init();
971     atexit(qemu_nbd_shutdown);
972 
973     srcpath = argv[optind];
974     if (imageOpts) {
975         QemuOpts *opts;
976         if (fmt) {
977             error_report("--image-opts and -f are mutually exclusive");
978             exit(EXIT_FAILURE);
979         }
980         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
981         if (!opts) {
982             qemu_opts_reset(&file_opts);
983             exit(EXIT_FAILURE);
984         }
985         options = qemu_opts_to_qdict(opts, NULL);
986         qemu_opts_reset(&file_opts);
987         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
988     } else {
989         if (fmt) {
990             options = qdict_new();
991             qdict_put_str(options, "driver", fmt);
992         }
993         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
994     }
995 
996     if (!blk) {
997         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
998                           argv[optind]);
999         exit(EXIT_FAILURE);
1000     }
1001     bs = blk_bs(blk);
1002 
1003     if (dev_offset) {
1004         QDict *raw_opts = qdict_new();
1005         qdict_put_str(raw_opts, "driver", "raw");
1006         qdict_put_str(raw_opts, "file", bs->node_name);
1007         qdict_put_int(raw_opts, "offset", dev_offset);
1008         bs = bdrv_open(NULL, NULL, raw_opts, flags, &error_fatal);
1009         blk_remove_bs(blk);
1010         blk_insert_bs(blk, bs, &error_fatal);
1011         bdrv_unref(bs);
1012     }
1013 
1014     blk_set_enable_write_cache(blk, !writethrough);
1015 
1016     if (sn_opts) {
1017         ret = bdrv_snapshot_load_tmp(bs,
1018                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1019                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1020                                      &local_err);
1021     } else if (sn_id_or_name) {
1022         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1023                                                    &local_err);
1024     }
1025     if (ret < 0) {
1026         error_reportf_err(local_err, "Failed to load snapshot: ");
1027         exit(EXIT_FAILURE);
1028     }
1029 
1030     bs->detect_zeroes = detect_zeroes;
1031 
1032     nbd_server_is_qemu_nbd(true);
1033 
1034     export_opts = g_new(BlockExportOptions, 1);
1035     *export_opts = (BlockExportOptions) {
1036         .type               = BLOCK_EXPORT_TYPE_NBD,
1037         .id                 = g_strdup("qemu-nbd-export"),
1038         .node_name          = g_strdup(bdrv_get_node_name(bs)),
1039         .has_writethrough   = true,
1040         .writethrough       = writethrough,
1041         .has_writable       = true,
1042         .writable           = !readonly,
1043         .u.nbd = {
1044             .has_name             = true,
1045             .name                 = g_strdup(export_name),
1046             .has_description      = !!export_description,
1047             .description          = g_strdup(export_description),
1048             .has_bitmaps          = !!bitmaps,
1049             .bitmaps              = bitmaps,
1050             .has_allocation_depth = alloc_depth,
1051             .allocation_depth     = alloc_depth,
1052         },
1053     };
1054     blk_exp_add(export_opts, &error_fatal);
1055     qapi_free_BlockExportOptions(export_opts);
1056 
1057     if (device) {
1058 #if HAVE_NBD_DEVICE
1059         int ret;
1060 
1061         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
1062         if (ret != 0) {
1063             error_report("Failed to create client thread: %s", strerror(ret));
1064             exit(EXIT_FAILURE);
1065         }
1066 #endif
1067     } else {
1068         /* Shut up GCC warnings.  */
1069         memset(&client_thread, 0, sizeof(client_thread));
1070     }
1071 
1072     nbd_update_server_watch();
1073 
1074     if (pid_file_name) {
1075         qemu_write_pidfile(pid_file_name, &error_fatal);
1076     }
1077 
1078     /* now when the initialization is (almost) complete, chdir("/")
1079      * to free any busy filesystems */
1080     if (chdir("/") < 0) {
1081         error_report("Could not chdir to root directory: %s",
1082                      strerror(errno));
1083         exit(EXIT_FAILURE);
1084     }
1085 
1086     if (fork_process) {
1087         dup2(old_stderr, STDERR_FILENO);
1088         close(old_stderr);
1089     }
1090 
1091     state = RUNNING;
1092     do {
1093         main_loop_wait(false);
1094         if (state == TERMINATE) {
1095             blk_exp_close_all();
1096             state = TERMINATED;
1097         }
1098     } while (state != TERMINATED);
1099 
1100     blk_unref(blk);
1101     if (sockpath) {
1102         unlink(sockpath);
1103     }
1104 
1105     qemu_opts_del(sn_opts);
1106 
1107     if (device) {
1108         void *ret;
1109         pthread_join(client_thread, &ret);
1110         exit(ret != NULL);
1111     } else {
1112         exit(EXIT_SUCCESS);
1113     }
1114 }
1115