xref: /openbmc/qemu/qemu-nbd.c (revision dd8d6a2d)
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 "qapi/error.h"
25 #include "qemu/cutils.h"
26 #include "sysemu/block-backend.h"
27 #include "block/block_int.h"
28 #include "block/nbd.h"
29 #include "qemu/main-loop.h"
30 #include "qemu/option.h"
31 #include "qemu/error-report.h"
32 #include "qemu/config-file.h"
33 #include "qemu/bswap.h"
34 #include "qemu/log.h"
35 #include "qemu/systemd.h"
36 #include "block/snapshot.h"
37 #include "qapi/qmp/qdict.h"
38 #include "qapi/qmp/qstring.h"
39 #include "qom/object_interfaces.h"
40 #include "io/channel-socket.h"
41 #include "io/net-listener.h"
42 #include "crypto/init.h"
43 #include "trace/control.h"
44 #include "qemu-version.h"
45 
46 #ifdef __linux__
47 #define HAVE_NBD_DEVICE 1
48 #else
49 #define HAVE_NBD_DEVICE 0
50 #endif
51 
52 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
53 #define QEMU_NBD_OPT_CACHE         256
54 #define QEMU_NBD_OPT_AIO           257
55 #define QEMU_NBD_OPT_DISCARD       258
56 #define QEMU_NBD_OPT_DETECT_ZEROES 259
57 #define QEMU_NBD_OPT_OBJECT        260
58 #define QEMU_NBD_OPT_TLSCREDS      261
59 #define QEMU_NBD_OPT_IMAGE_OPTS    262
60 #define QEMU_NBD_OPT_FORK          263
61 #define QEMU_NBD_OPT_TLSAUTHZ      264
62 
63 #define MBR_SIZE 512
64 
65 static NBDExport *export;
66 static int verbose;
67 static char *srcpath;
68 static SocketAddress *saddr;
69 static int persistent = 0;
70 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
71 static int shared = 1;
72 static int nb_fds;
73 static QIONetListener *server;
74 static QCryptoTLSCreds *tlscreds;
75 static const char *tlsauthz;
76 
77 static void usage(const char *name)
78 {
79     (printf) (
80 "Usage: %s [OPTIONS] FILE\n"
81 "  or:  %s -L [OPTIONS]\n"
82 "QEMU Disk Network Block Device Utility\n"
83 "\n"
84 "  -h, --help                display this help and exit\n"
85 "  -V, --version             output version information and exit\n"
86 "\n"
87 "Connection properties:\n"
88 "  -p, --port=PORT           port to listen on (default `%d')\n"
89 "  -b, --bind=IFACE          interface to bind to (default `0.0.0.0')\n"
90 "  -k, --socket=PATH         path to the unix socket\n"
91 "                            (default '"SOCKET_PATH"')\n"
92 "  -e, --shared=NUM          device can be shared by NUM clients (default '1')\n"
93 "  -t, --persistent          don't exit on the last connection\n"
94 "  -v, --verbose             display extra debugging information\n"
95 "  -x, --export-name=NAME    expose export by name (default is empty string)\n"
96 "  -D, --description=TEXT    export a human-readable description\n"
97 "\n"
98 "Exposing part of the image:\n"
99 "  -o, --offset=OFFSET       offset into the image\n"
100 "  -P, --partition=NUM       only expose partition NUM\n"
101 "  -B, --bitmap=NAME         expose a persistent dirty bitmap\n"
102 "\n"
103 "General purpose options:\n"
104 "  -L, --list                list exports available from another NBD server\n"
105 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
106 "                            passwords and/or encryption keys\n"
107 "  --tls-creds=ID            use id of an earlier --object to provide TLS\n"
108 "  --tls-authz=ID            use id of an earlier --object to provide\n"
109 "                            authorization\n"
110 "  -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
111 "                            specify tracing options\n"
112 "  --fork                    fork off the server process and exit the parent\n"
113 "                            once the server is running\n"
114 #if HAVE_NBD_DEVICE
115 "\n"
116 "Kernel NBD client support:\n"
117 "  -c, --connect=DEV         connect FILE to the local NBD device DEV\n"
118 "  -d, --disconnect          disconnect the specified device\n"
119 #endif
120 "\n"
121 "Block device options:\n"
122 "  -f, --format=FORMAT       set image format (raw, qcow2, ...)\n"
123 "  -r, --read-only           export read-only\n"
124 "  -s, --snapshot            use FILE as an external snapshot, create a temporary\n"
125 "                            file with backing_file=FILE, redirect the write to\n"
126 "                            the temporary one\n"
127 "  -l, --load-snapshot=SNAPSHOT_PARAM\n"
128 "                            load an internal snapshot inside FILE and export it\n"
129 "                            as an read-only device, SNAPSHOT_PARAM format is\n"
130 "                            'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
131 "                            '[ID_OR_NAME]'\n"
132 "  -n, --nocache             disable host cache\n"
133 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
134 "      --aio=MODE            set AIO mode (native or threads)\n"
135 "      --discard=MODE        set discard mode (ignore, unmap)\n"
136 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
137 "      --image-opts          treat FILE as a full set of image options\n"
138 "\n"
139 QEMU_HELP_BOTTOM "\n"
140     , name, name, NBD_DEFAULT_PORT, "DEVICE");
141 }
142 
143 static void version(const char *name)
144 {
145     printf(
146 "%s " QEMU_FULL_VERSION "\n"
147 "Written by Anthony Liguori.\n"
148 "\n"
149 QEMU_COPYRIGHT "\n"
150 "This is free software; see the source for copying conditions.  There is NO\n"
151 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
152     , name);
153 }
154 
155 struct partition_record
156 {
157     uint8_t bootable;
158     uint8_t start_head;
159     uint32_t start_cylinder;
160     uint8_t start_sector;
161     uint8_t system;
162     uint8_t end_head;
163     uint8_t end_cylinder;
164     uint8_t end_sector;
165     uint32_t start_sector_abs;
166     uint32_t nb_sectors_abs;
167 };
168 
169 static void read_partition(uint8_t *p, struct partition_record *r)
170 {
171     r->bootable = p[0];
172     r->start_head = p[1];
173     r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
174     r->start_sector = p[2] & 0x3f;
175     r->system = p[4];
176     r->end_head = p[5];
177     r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
178     r->end_sector = p[6] & 0x3f;
179 
180     r->start_sector_abs = ldl_le_p(p + 8);
181     r->nb_sectors_abs   = ldl_le_p(p + 12);
182 }
183 
184 static int find_partition(BlockBackend *blk, int partition,
185                           uint64_t *offset, uint64_t *size)
186 {
187     struct partition_record mbr[4];
188     uint8_t data[MBR_SIZE];
189     int i;
190     int ext_partnum = 4;
191     int ret;
192 
193     ret = blk_pread(blk, 0, data, sizeof(data));
194     if (ret < 0) {
195         error_report("error while reading: %s", strerror(-ret));
196         exit(EXIT_FAILURE);
197     }
198 
199     if (data[510] != 0x55 || data[511] != 0xaa) {
200         return -EINVAL;
201     }
202 
203     for (i = 0; i < 4; i++) {
204         read_partition(&data[446 + 16 * i], &mbr[i]);
205 
206         if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
207             continue;
208         }
209 
210         if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
211             struct partition_record ext[4];
212             uint8_t data1[MBR_SIZE];
213             int j;
214 
215             ret = blk_pread(blk, mbr[i].start_sector_abs * MBR_SIZE,
216                             data1, sizeof(data1));
217             if (ret < 0) {
218                 error_report("error while reading: %s", strerror(-ret));
219                 exit(EXIT_FAILURE);
220             }
221 
222             for (j = 0; j < 4; j++) {
223                 read_partition(&data1[446 + 16 * j], &ext[j]);
224                 if (!ext[j].system || !ext[j].nb_sectors_abs) {
225                     continue;
226                 }
227 
228                 if ((ext_partnum + j + 1) == partition) {
229                     *offset = (uint64_t)ext[j].start_sector_abs << 9;
230                     *size = (uint64_t)ext[j].nb_sectors_abs << 9;
231                     return 0;
232                 }
233             }
234             ext_partnum += 4;
235         } else if ((i + 1) == partition) {
236             *offset = (uint64_t)mbr[i].start_sector_abs << 9;
237             *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
238             return 0;
239         }
240     }
241 
242     return -ENOENT;
243 }
244 
245 static void termsig_handler(int signum)
246 {
247     atomic_cmpxchg(&state, RUNNING, TERMINATE);
248     qemu_notify_event();
249 }
250 
251 
252 static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
253                                 const char *hostname)
254 {
255     int ret = EXIT_FAILURE;
256     int rc;
257     Error *err = NULL;
258     QIOChannelSocket *sioc;
259     NBDExportInfo *list;
260     int i, j;
261 
262     sioc = qio_channel_socket_new();
263     if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
264         error_report_err(err);
265         return EXIT_FAILURE;
266     }
267     rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
268                                  &err);
269     if (rc < 0) {
270         if (err) {
271             error_report_err(err);
272         }
273         goto out;
274     }
275     printf("exports available: %d\n", rc);
276     for (i = 0; i < rc; i++) {
277         printf(" export: '%s'\n", list[i].name);
278         if (list[i].description && *list[i].description) {
279             printf("  description: %s\n", list[i].description);
280         }
281         if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
282             printf("  size:  %" PRIu64 "\n", list[i].size);
283             printf("  flags: 0x%x (", list[i].flags);
284             if (list[i].flags & NBD_FLAG_READ_ONLY) {
285                 printf(" readonly");
286             }
287             if (list[i].flags & NBD_FLAG_SEND_FLUSH) {
288                 printf(" flush");
289             }
290             if (list[i].flags & NBD_FLAG_SEND_FUA) {
291                 printf(" fua");
292             }
293             if (list[i].flags & NBD_FLAG_ROTATIONAL) {
294                 printf(" rotational");
295             }
296             if (list[i].flags & NBD_FLAG_SEND_TRIM) {
297                 printf(" trim");
298             }
299             if (list[i].flags & NBD_FLAG_SEND_WRITE_ZEROES) {
300                 printf(" zeroes");
301             }
302             if (list[i].flags & NBD_FLAG_SEND_DF) {
303                 printf(" df");
304             }
305             if (list[i].flags & NBD_FLAG_CAN_MULTI_CONN) {
306                 printf(" multi");
307             }
308             if (list[i].flags & NBD_FLAG_SEND_RESIZE) {
309                 printf(" resize");
310             }
311             if (list[i].flags & NBD_FLAG_SEND_CACHE) {
312                 printf(" cache");
313             }
314             printf(" )\n");
315         }
316         if (list[i].min_block) {
317             printf("  min block: %u\n", list[i].min_block);
318             printf("  opt block: %u\n", list[i].opt_block);
319             printf("  max block: %u\n", list[i].max_block);
320         }
321         if (list[i].n_contexts) {
322             printf("  available meta contexts: %d\n", list[i].n_contexts);
323             for (j = 0; j < list[i].n_contexts; j++) {
324                 printf("   %s\n", list[i].contexts[j]);
325             }
326         }
327     }
328     nbd_free_export_list(list, rc);
329 
330     ret = EXIT_SUCCESS;
331  out:
332     object_unref(OBJECT(sioc));
333     return ret;
334 }
335 
336 
337 #if HAVE_NBD_DEVICE
338 static void *show_parts(void *arg)
339 {
340     char *device = arg;
341     int nbd;
342 
343     /* linux just needs an open() to trigger
344      * the partition table update
345      * but remember to load the module with max_part != 0 :
346      *     modprobe nbd max_part=63
347      */
348     nbd = open(device, O_RDWR);
349     if (nbd >= 0) {
350         close(nbd);
351     }
352     return NULL;
353 }
354 
355 static void *nbd_client_thread(void *arg)
356 {
357     char *device = arg;
358     NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };
359     QIOChannelSocket *sioc;
360     int fd;
361     int ret;
362     pthread_t show_parts_thread;
363     Error *local_error = NULL;
364 
365     sioc = qio_channel_socket_new();
366     if (qio_channel_socket_connect_sync(sioc,
367                                         saddr,
368                                         &local_error) < 0) {
369         error_report_err(local_error);
370         goto out;
371     }
372 
373     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc),
374                                 NULL, NULL, NULL, &info, &local_error);
375     if (ret < 0) {
376         if (local_error) {
377             error_report_err(local_error);
378         }
379         goto out_socket;
380     }
381 
382     fd = open(device, O_RDWR);
383     if (fd < 0) {
384         /* Linux-only, we can use %m in printf.  */
385         error_report("Failed to open %s: %m", device);
386         goto out_socket;
387     }
388 
389     ret = nbd_init(fd, sioc, &info, &local_error);
390     if (ret < 0) {
391         error_report_err(local_error);
392         goto out_fd;
393     }
394 
395     /* update partition table */
396     pthread_create(&show_parts_thread, NULL, show_parts, device);
397 
398     if (verbose) {
399         fprintf(stderr, "NBD device %s is now connected to %s\n",
400                 device, srcpath);
401     } else {
402         /* Close stderr so that the qemu-nbd process exits.  */
403         dup2(STDOUT_FILENO, STDERR_FILENO);
404     }
405 
406     ret = nbd_client(fd);
407     if (ret) {
408         goto out_fd;
409     }
410     close(fd);
411     object_unref(OBJECT(sioc));
412     g_free(info.name);
413     kill(getpid(), SIGTERM);
414     return (void *) EXIT_SUCCESS;
415 
416 out_fd:
417     close(fd);
418 out_socket:
419     object_unref(OBJECT(sioc));
420 out:
421     g_free(info.name);
422     kill(getpid(), SIGTERM);
423     return (void *) EXIT_FAILURE;
424 }
425 #endif /* HAVE_NBD_DEVICE */
426 
427 static int nbd_can_accept(void)
428 {
429     return state == RUNNING && nb_fds < shared;
430 }
431 
432 static void nbd_export_closed(NBDExport *export)
433 {
434     assert(state == TERMINATING);
435     state = TERMINATED;
436 }
437 
438 static void nbd_update_server_watch(void);
439 
440 static void nbd_client_closed(NBDClient *client, bool negotiated)
441 {
442     nb_fds--;
443     if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
444         state = TERMINATE;
445     }
446     nbd_update_server_watch();
447     nbd_client_put(client);
448 }
449 
450 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
451                        gpointer opaque)
452 {
453     if (state >= TERMINATE) {
454         return;
455     }
456 
457     nb_fds++;
458     nbd_update_server_watch();
459     nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
460 }
461 
462 static void nbd_update_server_watch(void)
463 {
464     if (nbd_can_accept()) {
465         qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
466     } else {
467         qio_net_listener_set_client_func(server, NULL, NULL, NULL);
468     }
469 }
470 
471 
472 static SocketAddress *nbd_build_socket_address(const char *sockpath,
473                                                const char *bindto,
474                                                const char *port)
475 {
476     SocketAddress *saddr;
477 
478     saddr = g_new0(SocketAddress, 1);
479     if (sockpath) {
480         saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
481         saddr->u.q_unix.path = g_strdup(sockpath);
482     } else {
483         InetSocketAddress *inet;
484         saddr->type = SOCKET_ADDRESS_TYPE_INET;
485         inet = &saddr->u.inet;
486         inet->host = g_strdup(bindto);
487         if (port) {
488             inet->port = g_strdup(port);
489         } else  {
490             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
491         }
492     }
493 
494     return saddr;
495 }
496 
497 
498 static QemuOptsList file_opts = {
499     .name = "file",
500     .implied_opt_name = "file",
501     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
502     .desc = {
503         /* no elements => accept any params */
504         { /* end of list */ }
505     },
506 };
507 
508 static QemuOptsList qemu_object_opts = {
509     .name = "object",
510     .implied_opt_name = "qom-type",
511     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
512     .desc = {
513         { }
514     },
515 };
516 
517 
518 
519 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
520                                           Error **errp)
521 {
522     Object *obj;
523     QCryptoTLSCreds *creds;
524 
525     obj = object_resolve_path_component(
526         object_get_objects_root(), id);
527     if (!obj) {
528         error_setg(errp, "No TLS credentials with id '%s'",
529                    id);
530         return NULL;
531     }
532     creds = (QCryptoTLSCreds *)
533         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
534     if (!creds) {
535         error_setg(errp, "Object with id '%s' is not TLS credentials",
536                    id);
537         return NULL;
538     }
539 
540     if (list) {
541         if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
542             error_setg(errp,
543                        "Expecting TLS credentials with a client endpoint");
544             return NULL;
545         }
546     } else {
547         if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
548             error_setg(errp,
549                        "Expecting TLS credentials with a server endpoint");
550             return NULL;
551         }
552     }
553     object_ref(obj);
554     return creds;
555 }
556 
557 static void setup_address_and_port(const char **address, const char **port)
558 {
559     if (*address == NULL) {
560         *address = "0.0.0.0";
561     }
562 
563     if (*port == NULL) {
564         *port = stringify(NBD_DEFAULT_PORT);
565     }
566 }
567 
568 /*
569  * Check socket parameters compatibility when socket activation is used.
570  */
571 static const char *socket_activation_validate_opts(const char *device,
572                                                    const char *sockpath,
573                                                    const char *address,
574                                                    const char *port,
575                                                    bool list)
576 {
577     if (device != NULL) {
578         return "NBD device can't be set when using socket activation";
579     }
580 
581     if (sockpath != NULL) {
582         return "Unix socket can't be set when using socket activation";
583     }
584 
585     if (address != NULL) {
586         return "The interface can't be set when using socket activation";
587     }
588 
589     if (port != NULL) {
590         return "TCP port number can't be set when using socket activation";
591     }
592 
593     if (list) {
594         return "List mode is incompatible with socket activation";
595     }
596 
597     return NULL;
598 }
599 
600 static void qemu_nbd_shutdown(void)
601 {
602     job_cancel_sync_all();
603     bdrv_close_all();
604 }
605 
606 int main(int argc, char **argv)
607 {
608     BlockBackend *blk;
609     BlockDriverState *bs;
610     uint64_t dev_offset = 0;
611     uint16_t nbdflags = 0;
612     bool disconnect = false;
613     const char *bindto = NULL;
614     const char *port = NULL;
615     char *sockpath = NULL;
616     char *device = NULL;
617     int64_t fd_size;
618     QemuOpts *sn_opts = NULL;
619     const char *sn_id_or_name = NULL;
620     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:L";
621     struct option lopt[] = {
622         { "help", no_argument, NULL, 'h' },
623         { "version", no_argument, NULL, 'V' },
624         { "bind", required_argument, NULL, 'b' },
625         { "port", required_argument, NULL, 'p' },
626         { "socket", required_argument, NULL, 'k' },
627         { "offset", required_argument, NULL, 'o' },
628         { "read-only", no_argument, NULL, 'r' },
629         { "partition", required_argument, NULL, 'P' },
630         { "bitmap", required_argument, NULL, 'B' },
631         { "connect", required_argument, NULL, 'c' },
632         { "disconnect", no_argument, NULL, 'd' },
633         { "list", no_argument, NULL, 'L' },
634         { "snapshot", no_argument, NULL, 's' },
635         { "load-snapshot", required_argument, NULL, 'l' },
636         { "nocache", no_argument, NULL, 'n' },
637         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
638         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
639         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
640         { "detect-zeroes", required_argument, NULL,
641           QEMU_NBD_OPT_DETECT_ZEROES },
642         { "shared", required_argument, NULL, 'e' },
643         { "format", required_argument, NULL, 'f' },
644         { "persistent", no_argument, NULL, 't' },
645         { "verbose", no_argument, NULL, 'v' },
646         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
647         { "export-name", required_argument, NULL, 'x' },
648         { "description", required_argument, NULL, 'D' },
649         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
650         { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
651         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
652         { "trace", required_argument, NULL, 'T' },
653         { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
654         { NULL, 0, NULL, 0 }
655     };
656     int ch;
657     int opt_ind = 0;
658     int flags = BDRV_O_RDWR;
659     int partition = 0;
660     int ret = 0;
661     bool seen_cache = false;
662     bool seen_discard = false;
663     bool seen_aio = false;
664     pthread_t client_thread;
665     const char *fmt = NULL;
666     Error *local_err = NULL;
667     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
668     QDict *options = NULL;
669     const char *export_name = NULL; /* defaults to "" later for server mode */
670     const char *export_description = NULL;
671     const char *bitmap = NULL;
672     const char *tlscredsid = NULL;
673     bool imageOpts = false;
674     bool writethrough = true;
675     char *trace_file = NULL;
676     bool fork_process = false;
677     bool list = false;
678     int old_stderr = -1;
679     unsigned socket_activation;
680 
681     /* The client thread uses SIGTERM to interrupt the server.  A signal
682      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
683      */
684     struct sigaction sa_sigterm;
685     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
686     sa_sigterm.sa_handler = termsig_handler;
687     sigaction(SIGTERM, &sa_sigterm, NULL);
688 
689 #ifdef CONFIG_POSIX
690     signal(SIGPIPE, SIG_IGN);
691 #endif
692 
693     module_call_init(MODULE_INIT_TRACE);
694     error_set_progname(argv[0]);
695     qcrypto_init(&error_fatal);
696 
697     module_call_init(MODULE_INIT_QOM);
698     qemu_add_opts(&qemu_object_opts);
699     qemu_add_opts(&qemu_trace_opts);
700     qemu_init_exec_dir(argv[0]);
701 
702     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
703         switch (ch) {
704         case 's':
705             flags |= BDRV_O_SNAPSHOT;
706             break;
707         case 'n':
708             optarg = (char *) "none";
709             /* fallthrough */
710         case QEMU_NBD_OPT_CACHE:
711             if (seen_cache) {
712                 error_report("-n and --cache can only be specified once");
713                 exit(EXIT_FAILURE);
714             }
715             seen_cache = true;
716             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
717                 error_report("Invalid cache mode `%s'", optarg);
718                 exit(EXIT_FAILURE);
719             }
720             break;
721         case QEMU_NBD_OPT_AIO:
722             if (seen_aio) {
723                 error_report("--aio can only be specified once");
724                 exit(EXIT_FAILURE);
725             }
726             seen_aio = true;
727             if (!strcmp(optarg, "native")) {
728                 flags |= BDRV_O_NATIVE_AIO;
729             } else if (!strcmp(optarg, "threads")) {
730                 /* this is the default */
731             } else {
732                error_report("invalid aio mode `%s'", optarg);
733                exit(EXIT_FAILURE);
734             }
735             break;
736         case QEMU_NBD_OPT_DISCARD:
737             if (seen_discard) {
738                 error_report("--discard can only be specified once");
739                 exit(EXIT_FAILURE);
740             }
741             seen_discard = true;
742             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
743                 error_report("Invalid discard mode `%s'", optarg);
744                 exit(EXIT_FAILURE);
745             }
746             break;
747         case QEMU_NBD_OPT_DETECT_ZEROES:
748             detect_zeroes =
749                 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
750                                 optarg,
751                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
752                                 &local_err);
753             if (local_err) {
754                 error_reportf_err(local_err,
755                                   "Failed to parse detect_zeroes mode: ");
756                 exit(EXIT_FAILURE);
757             }
758             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
759                 !(flags & BDRV_O_UNMAP)) {
760                 error_report("setting detect-zeroes to unmap is not allowed "
761                              "without setting discard operation to unmap");
762                 exit(EXIT_FAILURE);
763             }
764             break;
765         case 'b':
766             bindto = optarg;
767             break;
768         case 'p':
769             port = optarg;
770             break;
771         case 'o':
772             if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
773                 error_report("Invalid offset '%s'", optarg);
774                 exit(EXIT_FAILURE);
775             }
776             break;
777         case 'l':
778             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
779                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
780                                                   optarg, false);
781                 if (!sn_opts) {
782                     error_report("Failed in parsing snapshot param `%s'",
783                                  optarg);
784                     exit(EXIT_FAILURE);
785                 }
786             } else {
787                 sn_id_or_name = optarg;
788             }
789             /* fall through */
790         case 'r':
791             nbdflags |= NBD_FLAG_READ_ONLY;
792             flags &= ~BDRV_O_RDWR;
793             break;
794         case 'P':
795             warn_report("The '-P' option is deprecated; use --image-opts with "
796                         "a raw device wrapper for subset exports instead");
797             if (qemu_strtoi(optarg, NULL, 0, &partition) < 0 ||
798                 partition < 1 || partition > 8) {
799                 error_report("Invalid partition '%s'", optarg);
800                 exit(EXIT_FAILURE);
801             }
802             break;
803         case 'B':
804             bitmap = optarg;
805             break;
806         case 'k':
807             sockpath = optarg;
808             if (sockpath[0] != '/') {
809                 error_report("socket path must be absolute");
810                 exit(EXIT_FAILURE);
811             }
812             break;
813         case 'd':
814             disconnect = true;
815             break;
816         case 'c':
817             device = optarg;
818             break;
819         case 'e':
820             if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
821                 shared < 1) {
822                 error_report("Invalid shared device number '%s'", optarg);
823                 exit(EXIT_FAILURE);
824             }
825             break;
826         case 'f':
827             fmt = optarg;
828             break;
829         case 't':
830             persistent = 1;
831             break;
832         case 'x':
833             export_name = optarg;
834             break;
835         case 'D':
836             export_description = optarg;
837             break;
838         case 'v':
839             verbose = 1;
840             break;
841         case 'V':
842             version(argv[0]);
843             exit(0);
844             break;
845         case 'h':
846             usage(argv[0]);
847             exit(0);
848             break;
849         case '?':
850             error_report("Try `%s --help' for more information.", argv[0]);
851             exit(EXIT_FAILURE);
852         case QEMU_NBD_OPT_OBJECT: {
853             QemuOpts *opts;
854             opts = qemu_opts_parse_noisily(&qemu_object_opts,
855                                            optarg, true);
856             if (!opts) {
857                 exit(EXIT_FAILURE);
858             }
859         }   break;
860         case QEMU_NBD_OPT_TLSCREDS:
861             tlscredsid = optarg;
862             break;
863         case QEMU_NBD_OPT_IMAGE_OPTS:
864             imageOpts = true;
865             break;
866         case 'T':
867             g_free(trace_file);
868             trace_file = trace_opt_parse(optarg);
869             break;
870         case QEMU_NBD_OPT_TLSAUTHZ:
871             tlsauthz = optarg;
872             break;
873         case QEMU_NBD_OPT_FORK:
874             fork_process = true;
875             break;
876         case 'L':
877             list = true;
878             break;
879         }
880     }
881 
882     if (list) {
883         if (argc != optind) {
884             error_report("List mode is incompatible with a file name");
885             exit(EXIT_FAILURE);
886         }
887         if (export_name || export_description || dev_offset || partition ||
888             device || disconnect || fmt || sn_id_or_name || bitmap ||
889             seen_aio || seen_discard || seen_cache) {
890             error_report("List mode is incompatible with per-device settings");
891             exit(EXIT_FAILURE);
892         }
893         if (fork_process) {
894             error_report("List mode is incompatible with forking");
895             exit(EXIT_FAILURE);
896         }
897     } else if ((argc - optind) != 1) {
898         error_report("Invalid number of arguments");
899         error_printf("Try `%s --help' for more information.\n", argv[0]);
900         exit(EXIT_FAILURE);
901     } else if (!export_name) {
902         export_name = "";
903     }
904 
905     qemu_opts_foreach(&qemu_object_opts,
906                       user_creatable_add_opts_foreach,
907                       NULL, &error_fatal);
908 
909     if (!trace_init_backends()) {
910         exit(1);
911     }
912     trace_init_file(trace_file);
913     qemu_set_log(LOG_TRACE);
914 
915     socket_activation = check_socket_activation();
916     if (socket_activation == 0) {
917         setup_address_and_port(&bindto, &port);
918     } else {
919         /* Using socket activation - check user didn't use -p etc. */
920         const char *err_msg = socket_activation_validate_opts(device, sockpath,
921                                                               bindto, port,
922                                                               list);
923         if (err_msg != NULL) {
924             error_report("%s", err_msg);
925             exit(EXIT_FAILURE);
926         }
927 
928         /* qemu-nbd can only listen on a single socket.  */
929         if (socket_activation > 1) {
930             error_report("qemu-nbd does not support socket activation with %s > 1",
931                          "LISTEN_FDS");
932             exit(EXIT_FAILURE);
933         }
934     }
935 
936     if (tlscredsid) {
937         if (sockpath) {
938             error_report("TLS is only supported with IPv4/IPv6");
939             exit(EXIT_FAILURE);
940         }
941         if (device) {
942             error_report("TLS is not supported with a host device");
943             exit(EXIT_FAILURE);
944         }
945         if (tlsauthz && list) {
946             error_report("TLS authorization is incompatible with export list");
947             exit(EXIT_FAILURE);
948         }
949         tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
950         if (local_err) {
951             error_report("Failed to get TLS creds %s",
952                          error_get_pretty(local_err));
953             exit(EXIT_FAILURE);
954         }
955     } else {
956         if (tlsauthz) {
957             error_report("--tls-authz is not permitted without --tls-creds");
958             exit(EXIT_FAILURE);
959         }
960     }
961 
962     if (list) {
963         saddr = nbd_build_socket_address(sockpath, bindto, port);
964         return qemu_nbd_client_list(saddr, tlscreds, bindto);
965     }
966 
967 #if !HAVE_NBD_DEVICE
968     if (disconnect || device) {
969         error_report("Kernel /dev/nbdN support not available");
970         exit(EXIT_FAILURE);
971     }
972 #else /* HAVE_NBD_DEVICE */
973     if (disconnect) {
974         int nbdfd = open(argv[optind], O_RDWR);
975         if (nbdfd < 0) {
976             error_report("Cannot open %s: %s", argv[optind],
977                          strerror(errno));
978             exit(EXIT_FAILURE);
979         }
980         nbd_disconnect(nbdfd);
981 
982         close(nbdfd);
983 
984         printf("%s disconnected\n", argv[optind]);
985 
986         return 0;
987     }
988 #endif
989 
990     if ((device && !verbose) || fork_process) {
991         int stderr_fd[2];
992         pid_t pid;
993         int ret;
994 
995         if (qemu_pipe(stderr_fd) < 0) {
996             error_report("Error setting up communication pipe: %s",
997                          strerror(errno));
998             exit(EXIT_FAILURE);
999         }
1000 
1001         /* Now daemonize, but keep a communication channel open to
1002          * print errors and exit with the proper status code.
1003          */
1004         pid = fork();
1005         if (pid < 0) {
1006             error_report("Failed to fork: %s", strerror(errno));
1007             exit(EXIT_FAILURE);
1008         } else if (pid == 0) {
1009             close(stderr_fd[0]);
1010             ret = qemu_daemon(1, 0);
1011 
1012             /* Temporarily redirect stderr to the parent's pipe...  */
1013             old_stderr = dup(STDERR_FILENO);
1014             dup2(stderr_fd[1], STDERR_FILENO);
1015             if (ret < 0) {
1016                 error_report("Failed to daemonize: %s", strerror(errno));
1017                 exit(EXIT_FAILURE);
1018             }
1019 
1020             /* ... close the descriptor we inherited and go on.  */
1021             close(stderr_fd[1]);
1022         } else {
1023             bool errors = false;
1024             char *buf;
1025 
1026             /* In the parent.  Print error messages from the child until
1027              * it closes the pipe.
1028              */
1029             close(stderr_fd[1]);
1030             buf = g_malloc(1024);
1031             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
1032                 errors = true;
1033                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
1034                 if (ret < 0) {
1035                     exit(EXIT_FAILURE);
1036                 }
1037             }
1038             if (ret < 0) {
1039                 error_report("Cannot read from daemon: %s",
1040                              strerror(errno));
1041                 exit(EXIT_FAILURE);
1042             }
1043 
1044             /* Usually the daemon should not print any message.
1045              * Exit with zero status in that case.
1046              */
1047             exit(errors);
1048         }
1049     }
1050 
1051     if (device != NULL && sockpath == NULL) {
1052         sockpath = g_malloc(128);
1053         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
1054     }
1055 
1056     server = qio_net_listener_new();
1057     if (socket_activation == 0) {
1058         saddr = nbd_build_socket_address(sockpath, bindto, port);
1059         if (qio_net_listener_open_sync(server, saddr, &local_err) < 0) {
1060             object_unref(OBJECT(server));
1061             error_report_err(local_err);
1062             exit(EXIT_FAILURE);
1063         }
1064     } else {
1065         size_t i;
1066         /* See comment in check_socket_activation above. */
1067         for (i = 0; i < socket_activation; i++) {
1068             QIOChannelSocket *sioc;
1069             sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
1070                                              &local_err);
1071             if (sioc == NULL) {
1072                 object_unref(OBJECT(server));
1073                 error_report("Failed to use socket activation: %s",
1074                              error_get_pretty(local_err));
1075                 exit(EXIT_FAILURE);
1076             }
1077             qio_net_listener_add(server, sioc);
1078             object_unref(OBJECT(sioc));
1079         }
1080     }
1081 
1082     if (qemu_init_main_loop(&local_err)) {
1083         error_report_err(local_err);
1084         exit(EXIT_FAILURE);
1085     }
1086     bdrv_init();
1087     atexit(qemu_nbd_shutdown);
1088 
1089     srcpath = argv[optind];
1090     if (imageOpts) {
1091         QemuOpts *opts;
1092         if (fmt) {
1093             error_report("--image-opts and -f are mutually exclusive");
1094             exit(EXIT_FAILURE);
1095         }
1096         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
1097         if (!opts) {
1098             qemu_opts_reset(&file_opts);
1099             exit(EXIT_FAILURE);
1100         }
1101         options = qemu_opts_to_qdict(opts, NULL);
1102         qemu_opts_reset(&file_opts);
1103         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
1104     } else {
1105         if (fmt) {
1106             options = qdict_new();
1107             qdict_put_str(options, "driver", fmt);
1108         }
1109         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
1110     }
1111 
1112     if (!blk) {
1113         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
1114                           argv[optind]);
1115         exit(EXIT_FAILURE);
1116     }
1117     bs = blk_bs(blk);
1118 
1119     blk_set_enable_write_cache(blk, !writethrough);
1120 
1121     if (sn_opts) {
1122         ret = bdrv_snapshot_load_tmp(bs,
1123                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1124                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1125                                      &local_err);
1126     } else if (sn_id_or_name) {
1127         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1128                                                    &local_err);
1129     }
1130     if (ret < 0) {
1131         error_reportf_err(local_err, "Failed to load snapshot: ");
1132         exit(EXIT_FAILURE);
1133     }
1134 
1135     bs->detect_zeroes = detect_zeroes;
1136     fd_size = blk_getlength(blk);
1137     if (fd_size < 0) {
1138         error_report("Failed to determine the image length: %s",
1139                      strerror(-fd_size));
1140         exit(EXIT_FAILURE);
1141     }
1142 
1143     if (dev_offset >= fd_size) {
1144         error_report("Offset (%" PRIu64 ") has to be smaller than the image "
1145                      "size (%" PRId64 ")", dev_offset, fd_size);
1146         exit(EXIT_FAILURE);
1147     }
1148     fd_size -= dev_offset;
1149 
1150     if (partition) {
1151         uint64_t limit;
1152 
1153         if (dev_offset) {
1154             error_report("Cannot request partition and offset together");
1155             exit(EXIT_FAILURE);
1156         }
1157         ret = find_partition(blk, partition, &dev_offset, &limit);
1158         if (ret < 0) {
1159             error_report("Could not find partition %d: %s", partition,
1160                          strerror(-ret));
1161             exit(EXIT_FAILURE);
1162         }
1163         /*
1164          * MBR partition limits are (32-bit << 9); this assert lets
1165          * the compiler know that we can't overflow 64 bits.
1166          */
1167         assert(dev_offset + limit >= dev_offset);
1168         if (dev_offset + limit > fd_size) {
1169             error_report("Discovered partition %d at offset %" PRIu64
1170                          " size %" PRIu64 ", but size exceeds file length %"
1171                          PRId64, partition, dev_offset, limit, fd_size);
1172             exit(EXIT_FAILURE);
1173         }
1174         fd_size = limit;
1175     }
1176 
1177     export = nbd_export_new(bs, dev_offset, fd_size, export_name,
1178                             export_description, bitmap, nbdflags,
1179                             nbd_export_closed, writethrough, NULL,
1180                             &error_fatal);
1181 
1182     if (device) {
1183 #if HAVE_NBD_DEVICE
1184         int ret;
1185 
1186         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
1187         if (ret != 0) {
1188             error_report("Failed to create client thread: %s", strerror(ret));
1189             exit(EXIT_FAILURE);
1190         }
1191 #endif
1192     } else {
1193         /* Shut up GCC warnings.  */
1194         memset(&client_thread, 0, sizeof(client_thread));
1195     }
1196 
1197     nbd_update_server_watch();
1198 
1199     /* now when the initialization is (almost) complete, chdir("/")
1200      * to free any busy filesystems */
1201     if (chdir("/") < 0) {
1202         error_report("Could not chdir to root directory: %s",
1203                      strerror(errno));
1204         exit(EXIT_FAILURE);
1205     }
1206 
1207     if (fork_process) {
1208         dup2(old_stderr, STDERR_FILENO);
1209         close(old_stderr);
1210     }
1211 
1212     state = RUNNING;
1213     do {
1214         main_loop_wait(false);
1215         if (state == TERMINATE) {
1216             state = TERMINATING;
1217             nbd_export_close(export);
1218             nbd_export_put(export);
1219             export = NULL;
1220         }
1221     } while (state != TERMINATED);
1222 
1223     blk_unref(blk);
1224     if (sockpath) {
1225         unlink(sockpath);
1226     }
1227 
1228     qemu_opts_del(sn_opts);
1229 
1230     if (device) {
1231         void *ret;
1232         pthread_join(client_thread, &ret);
1233         exit(ret != NULL);
1234     } else {
1235         exit(EXIT_SUCCESS);
1236     }
1237 }
1238