xref: /openbmc/qemu/qemu-nbd.c (revision 49d755d0)
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             static const char *const flag_names[] = {
283                 [NBD_FLAG_READ_ONLY_BIT]            = "readonly",
284                 [NBD_FLAG_SEND_FLUSH_BIT]           = "flush",
285                 [NBD_FLAG_SEND_FUA_BIT]             = "fua",
286                 [NBD_FLAG_ROTATIONAL_BIT]           = "rotational",
287                 [NBD_FLAG_SEND_TRIM_BIT]            = "trim",
288                 [NBD_FLAG_SEND_WRITE_ZEROES_BIT]    = "zeroes",
289                 [NBD_FLAG_SEND_DF_BIT]              = "df",
290                 [NBD_FLAG_CAN_MULTI_CONN_BIT]       = "multi",
291                 [NBD_FLAG_SEND_RESIZE_BIT]          = "resize",
292                 [NBD_FLAG_SEND_CACHE_BIT]           = "cache",
293             };
294 
295             printf("  size:  %" PRIu64 "\n", list[i].size);
296             printf("  flags: 0x%x (", list[i].flags);
297             for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) {
298                 if (flag_names[bit] && (list[i].flags & (1 << bit))) {
299                     printf(" %s", flag_names[bit]);
300                 }
301             }
302             printf(" )\n");
303         }
304         if (list[i].min_block) {
305             printf("  min block: %u\n", list[i].min_block);
306             printf("  opt block: %u\n", list[i].opt_block);
307             printf("  max block: %u\n", list[i].max_block);
308         }
309         if (list[i].n_contexts) {
310             printf("  available meta contexts: %d\n", list[i].n_contexts);
311             for (j = 0; j < list[i].n_contexts; j++) {
312                 printf("   %s\n", list[i].contexts[j]);
313             }
314         }
315     }
316     nbd_free_export_list(list, rc);
317 
318     ret = EXIT_SUCCESS;
319  out:
320     object_unref(OBJECT(sioc));
321     return ret;
322 }
323 
324 
325 #if HAVE_NBD_DEVICE
326 static void *show_parts(void *arg)
327 {
328     char *device = arg;
329     int nbd;
330 
331     /* linux just needs an open() to trigger
332      * the partition table update
333      * but remember to load the module with max_part != 0 :
334      *     modprobe nbd max_part=63
335      */
336     nbd = open(device, O_RDWR);
337     if (nbd >= 0) {
338         close(nbd);
339     }
340     return NULL;
341 }
342 
343 static void *nbd_client_thread(void *arg)
344 {
345     char *device = arg;
346     NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };
347     QIOChannelSocket *sioc;
348     int fd;
349     int ret;
350     pthread_t show_parts_thread;
351     Error *local_error = NULL;
352 
353     sioc = qio_channel_socket_new();
354     if (qio_channel_socket_connect_sync(sioc,
355                                         saddr,
356                                         &local_error) < 0) {
357         error_report_err(local_error);
358         goto out;
359     }
360 
361     ret = nbd_receive_negotiate(QIO_CHANNEL(sioc),
362                                 NULL, NULL, NULL, &info, &local_error);
363     if (ret < 0) {
364         if (local_error) {
365             error_report_err(local_error);
366         }
367         goto out_socket;
368     }
369 
370     fd = open(device, O_RDWR);
371     if (fd < 0) {
372         /* Linux-only, we can use %m in printf.  */
373         error_report("Failed to open %s: %m", device);
374         goto out_socket;
375     }
376 
377     ret = nbd_init(fd, sioc, &info, &local_error);
378     if (ret < 0) {
379         error_report_err(local_error);
380         goto out_fd;
381     }
382 
383     /* update partition table */
384     pthread_create(&show_parts_thread, NULL, show_parts, device);
385 
386     if (verbose) {
387         fprintf(stderr, "NBD device %s is now connected to %s\n",
388                 device, srcpath);
389     } else {
390         /* Close stderr so that the qemu-nbd process exits.  */
391         dup2(STDOUT_FILENO, STDERR_FILENO);
392     }
393 
394     ret = nbd_client(fd);
395     if (ret) {
396         goto out_fd;
397     }
398     close(fd);
399     object_unref(OBJECT(sioc));
400     g_free(info.name);
401     kill(getpid(), SIGTERM);
402     return (void *) EXIT_SUCCESS;
403 
404 out_fd:
405     close(fd);
406 out_socket:
407     object_unref(OBJECT(sioc));
408 out:
409     g_free(info.name);
410     kill(getpid(), SIGTERM);
411     return (void *) EXIT_FAILURE;
412 }
413 #endif /* HAVE_NBD_DEVICE */
414 
415 static int nbd_can_accept(void)
416 {
417     return state == RUNNING && nb_fds < shared;
418 }
419 
420 static void nbd_export_closed(NBDExport *export)
421 {
422     assert(state == TERMINATING);
423     state = TERMINATED;
424 }
425 
426 static void nbd_update_server_watch(void);
427 
428 static void nbd_client_closed(NBDClient *client, bool negotiated)
429 {
430     nb_fds--;
431     if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
432         state = TERMINATE;
433     }
434     nbd_update_server_watch();
435     nbd_client_put(client);
436 }
437 
438 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
439                        gpointer opaque)
440 {
441     if (state >= TERMINATE) {
442         return;
443     }
444 
445     nb_fds++;
446     nbd_update_server_watch();
447     nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
448 }
449 
450 static void nbd_update_server_watch(void)
451 {
452     if (nbd_can_accept()) {
453         qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
454     } else {
455         qio_net_listener_set_client_func(server, NULL, NULL, NULL);
456     }
457 }
458 
459 
460 static SocketAddress *nbd_build_socket_address(const char *sockpath,
461                                                const char *bindto,
462                                                const char *port)
463 {
464     SocketAddress *saddr;
465 
466     saddr = g_new0(SocketAddress, 1);
467     if (sockpath) {
468         saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
469         saddr->u.q_unix.path = g_strdup(sockpath);
470     } else {
471         InetSocketAddress *inet;
472         saddr->type = SOCKET_ADDRESS_TYPE_INET;
473         inet = &saddr->u.inet;
474         inet->host = g_strdup(bindto);
475         if (port) {
476             inet->port = g_strdup(port);
477         } else  {
478             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
479         }
480     }
481 
482     return saddr;
483 }
484 
485 
486 static QemuOptsList file_opts = {
487     .name = "file",
488     .implied_opt_name = "file",
489     .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
490     .desc = {
491         /* no elements => accept any params */
492         { /* end of list */ }
493     },
494 };
495 
496 static QemuOptsList qemu_object_opts = {
497     .name = "object",
498     .implied_opt_name = "qom-type",
499     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
500     .desc = {
501         { }
502     },
503 };
504 
505 
506 
507 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
508                                           Error **errp)
509 {
510     Object *obj;
511     QCryptoTLSCreds *creds;
512 
513     obj = object_resolve_path_component(
514         object_get_objects_root(), id);
515     if (!obj) {
516         error_setg(errp, "No TLS credentials with id '%s'",
517                    id);
518         return NULL;
519     }
520     creds = (QCryptoTLSCreds *)
521         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
522     if (!creds) {
523         error_setg(errp, "Object with id '%s' is not TLS credentials",
524                    id);
525         return NULL;
526     }
527 
528     if (list) {
529         if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
530             error_setg(errp,
531                        "Expecting TLS credentials with a client endpoint");
532             return NULL;
533         }
534     } else {
535         if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
536             error_setg(errp,
537                        "Expecting TLS credentials with a server endpoint");
538             return NULL;
539         }
540     }
541     object_ref(obj);
542     return creds;
543 }
544 
545 static void setup_address_and_port(const char **address, const char **port)
546 {
547     if (*address == NULL) {
548         *address = "0.0.0.0";
549     }
550 
551     if (*port == NULL) {
552         *port = stringify(NBD_DEFAULT_PORT);
553     }
554 }
555 
556 /*
557  * Check socket parameters compatibility when socket activation is used.
558  */
559 static const char *socket_activation_validate_opts(const char *device,
560                                                    const char *sockpath,
561                                                    const char *address,
562                                                    const char *port,
563                                                    bool list)
564 {
565     if (device != NULL) {
566         return "NBD device can't be set when using socket activation";
567     }
568 
569     if (sockpath != NULL) {
570         return "Unix socket can't be set when using socket activation";
571     }
572 
573     if (address != NULL) {
574         return "The interface can't be set when using socket activation";
575     }
576 
577     if (port != NULL) {
578         return "TCP port number can't be set when using socket activation";
579     }
580 
581     if (list) {
582         return "List mode is incompatible with socket activation";
583     }
584 
585     return NULL;
586 }
587 
588 static void qemu_nbd_shutdown(void)
589 {
590     job_cancel_sync_all();
591     bdrv_close_all();
592 }
593 
594 int main(int argc, char **argv)
595 {
596     BlockBackend *blk;
597     BlockDriverState *bs;
598     uint64_t dev_offset = 0;
599     uint16_t nbdflags = 0;
600     bool disconnect = false;
601     const char *bindto = NULL;
602     const char *port = NULL;
603     char *sockpath = NULL;
604     char *device = NULL;
605     int64_t fd_size;
606     QemuOpts *sn_opts = NULL;
607     const char *sn_id_or_name = NULL;
608     const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:L";
609     struct option lopt[] = {
610         { "help", no_argument, NULL, 'h' },
611         { "version", no_argument, NULL, 'V' },
612         { "bind", required_argument, NULL, 'b' },
613         { "port", required_argument, NULL, 'p' },
614         { "socket", required_argument, NULL, 'k' },
615         { "offset", required_argument, NULL, 'o' },
616         { "read-only", no_argument, NULL, 'r' },
617         { "partition", required_argument, NULL, 'P' },
618         { "bitmap", required_argument, NULL, 'B' },
619         { "connect", required_argument, NULL, 'c' },
620         { "disconnect", no_argument, NULL, 'd' },
621         { "list", no_argument, NULL, 'L' },
622         { "snapshot", no_argument, NULL, 's' },
623         { "load-snapshot", required_argument, NULL, 'l' },
624         { "nocache", no_argument, NULL, 'n' },
625         { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
626         { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
627         { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
628         { "detect-zeroes", required_argument, NULL,
629           QEMU_NBD_OPT_DETECT_ZEROES },
630         { "shared", required_argument, NULL, 'e' },
631         { "format", required_argument, NULL, 'f' },
632         { "persistent", no_argument, NULL, 't' },
633         { "verbose", no_argument, NULL, 'v' },
634         { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
635         { "export-name", required_argument, NULL, 'x' },
636         { "description", required_argument, NULL, 'D' },
637         { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
638         { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
639         { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
640         { "trace", required_argument, NULL, 'T' },
641         { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
642         { NULL, 0, NULL, 0 }
643     };
644     int ch;
645     int opt_ind = 0;
646     int flags = BDRV_O_RDWR;
647     int partition = 0;
648     int ret = 0;
649     bool seen_cache = false;
650     bool seen_discard = false;
651     bool seen_aio = false;
652     pthread_t client_thread;
653     const char *fmt = NULL;
654     Error *local_err = NULL;
655     BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
656     QDict *options = NULL;
657     const char *export_name = NULL; /* defaults to "" later for server mode */
658     const char *export_description = NULL;
659     const char *bitmap = NULL;
660     const char *tlscredsid = NULL;
661     bool imageOpts = false;
662     bool writethrough = true;
663     char *trace_file = NULL;
664     bool fork_process = false;
665     bool list = false;
666     int old_stderr = -1;
667     unsigned socket_activation;
668 
669     /* The client thread uses SIGTERM to interrupt the server.  A signal
670      * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
671      */
672     struct sigaction sa_sigterm;
673     memset(&sa_sigterm, 0, sizeof(sa_sigterm));
674     sa_sigterm.sa_handler = termsig_handler;
675     sigaction(SIGTERM, &sa_sigterm, NULL);
676 
677 #ifdef CONFIG_POSIX
678     signal(SIGPIPE, SIG_IGN);
679 #endif
680 
681     error_init(argv[0]);
682     module_call_init(MODULE_INIT_TRACE);
683     qcrypto_init(&error_fatal);
684 
685     module_call_init(MODULE_INIT_QOM);
686     qemu_add_opts(&qemu_object_opts);
687     qemu_add_opts(&qemu_trace_opts);
688     qemu_init_exec_dir(argv[0]);
689 
690     while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
691         switch (ch) {
692         case 's':
693             flags |= BDRV_O_SNAPSHOT;
694             break;
695         case 'n':
696             optarg = (char *) "none";
697             /* fallthrough */
698         case QEMU_NBD_OPT_CACHE:
699             if (seen_cache) {
700                 error_report("-n and --cache can only be specified once");
701                 exit(EXIT_FAILURE);
702             }
703             seen_cache = true;
704             if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
705                 error_report("Invalid cache mode `%s'", optarg);
706                 exit(EXIT_FAILURE);
707             }
708             break;
709         case QEMU_NBD_OPT_AIO:
710             if (seen_aio) {
711                 error_report("--aio can only be specified once");
712                 exit(EXIT_FAILURE);
713             }
714             seen_aio = true;
715             if (!strcmp(optarg, "native")) {
716                 flags |= BDRV_O_NATIVE_AIO;
717             } else if (!strcmp(optarg, "threads")) {
718                 /* this is the default */
719             } else {
720                error_report("invalid aio mode `%s'", optarg);
721                exit(EXIT_FAILURE);
722             }
723             break;
724         case QEMU_NBD_OPT_DISCARD:
725             if (seen_discard) {
726                 error_report("--discard can only be specified once");
727                 exit(EXIT_FAILURE);
728             }
729             seen_discard = true;
730             if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
731                 error_report("Invalid discard mode `%s'", optarg);
732                 exit(EXIT_FAILURE);
733             }
734             break;
735         case QEMU_NBD_OPT_DETECT_ZEROES:
736             detect_zeroes =
737                 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
738                                 optarg,
739                                 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
740                                 &local_err);
741             if (local_err) {
742                 error_reportf_err(local_err,
743                                   "Failed to parse detect_zeroes mode: ");
744                 exit(EXIT_FAILURE);
745             }
746             if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
747                 !(flags & BDRV_O_UNMAP)) {
748                 error_report("setting detect-zeroes to unmap is not allowed "
749                              "without setting discard operation to unmap");
750                 exit(EXIT_FAILURE);
751             }
752             break;
753         case 'b':
754             bindto = optarg;
755             break;
756         case 'p':
757             port = optarg;
758             break;
759         case 'o':
760             if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
761                 error_report("Invalid offset '%s'", optarg);
762                 exit(EXIT_FAILURE);
763             }
764             break;
765         case 'l':
766             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
767                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
768                                                   optarg, false);
769                 if (!sn_opts) {
770                     error_report("Failed in parsing snapshot param `%s'",
771                                  optarg);
772                     exit(EXIT_FAILURE);
773                 }
774             } else {
775                 sn_id_or_name = optarg;
776             }
777             /* fall through */
778         case 'r':
779             nbdflags |= NBD_FLAG_READ_ONLY;
780             flags &= ~BDRV_O_RDWR;
781             break;
782         case 'P':
783             warn_report("The '-P' option is deprecated; use --image-opts with "
784                         "a raw device wrapper for subset exports instead");
785             if (qemu_strtoi(optarg, NULL, 0, &partition) < 0 ||
786                 partition < 1 || partition > 8) {
787                 error_report("Invalid partition '%s'", optarg);
788                 exit(EXIT_FAILURE);
789             }
790             break;
791         case 'B':
792             bitmap = optarg;
793             break;
794         case 'k':
795             sockpath = optarg;
796             if (sockpath[0] != '/') {
797                 error_report("socket path must be absolute");
798                 exit(EXIT_FAILURE);
799             }
800             break;
801         case 'd':
802             disconnect = true;
803             break;
804         case 'c':
805             device = optarg;
806             break;
807         case 'e':
808             if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
809                 shared < 1) {
810                 error_report("Invalid shared device number '%s'", optarg);
811                 exit(EXIT_FAILURE);
812             }
813             break;
814         case 'f':
815             fmt = optarg;
816             break;
817         case 't':
818             persistent = 1;
819             break;
820         case 'x':
821             export_name = optarg;
822             break;
823         case 'D':
824             export_description = optarg;
825             break;
826         case 'v':
827             verbose = 1;
828             break;
829         case 'V':
830             version(argv[0]);
831             exit(0);
832             break;
833         case 'h':
834             usage(argv[0]);
835             exit(0);
836             break;
837         case '?':
838             error_report("Try `%s --help' for more information.", argv[0]);
839             exit(EXIT_FAILURE);
840         case QEMU_NBD_OPT_OBJECT: {
841             QemuOpts *opts;
842             opts = qemu_opts_parse_noisily(&qemu_object_opts,
843                                            optarg, true);
844             if (!opts) {
845                 exit(EXIT_FAILURE);
846             }
847         }   break;
848         case QEMU_NBD_OPT_TLSCREDS:
849             tlscredsid = optarg;
850             break;
851         case QEMU_NBD_OPT_IMAGE_OPTS:
852             imageOpts = true;
853             break;
854         case 'T':
855             g_free(trace_file);
856             trace_file = trace_opt_parse(optarg);
857             break;
858         case QEMU_NBD_OPT_TLSAUTHZ:
859             tlsauthz = optarg;
860             break;
861         case QEMU_NBD_OPT_FORK:
862             fork_process = true;
863             break;
864         case 'L':
865             list = true;
866             break;
867         }
868     }
869 
870     if (list) {
871         if (argc != optind) {
872             error_report("List mode is incompatible with a file name");
873             exit(EXIT_FAILURE);
874         }
875         if (export_name || export_description || dev_offset || partition ||
876             device || disconnect || fmt || sn_id_or_name || bitmap ||
877             seen_aio || seen_discard || seen_cache) {
878             error_report("List mode is incompatible with per-device settings");
879             exit(EXIT_FAILURE);
880         }
881         if (fork_process) {
882             error_report("List mode is incompatible with forking");
883             exit(EXIT_FAILURE);
884         }
885     } else if ((argc - optind) != 1) {
886         error_report("Invalid number of arguments");
887         error_printf("Try `%s --help' for more information.\n", argv[0]);
888         exit(EXIT_FAILURE);
889     } else if (!export_name) {
890         export_name = "";
891     }
892 
893     qemu_opts_foreach(&qemu_object_opts,
894                       user_creatable_add_opts_foreach,
895                       NULL, &error_fatal);
896 
897     if (!trace_init_backends()) {
898         exit(1);
899     }
900     trace_init_file(trace_file);
901     qemu_set_log(LOG_TRACE);
902 
903     socket_activation = check_socket_activation();
904     if (socket_activation == 0) {
905         setup_address_and_port(&bindto, &port);
906     } else {
907         /* Using socket activation - check user didn't use -p etc. */
908         const char *err_msg = socket_activation_validate_opts(device, sockpath,
909                                                               bindto, port,
910                                                               list);
911         if (err_msg != NULL) {
912             error_report("%s", err_msg);
913             exit(EXIT_FAILURE);
914         }
915 
916         /* qemu-nbd can only listen on a single socket.  */
917         if (socket_activation > 1) {
918             error_report("qemu-nbd does not support socket activation with %s > 1",
919                          "LISTEN_FDS");
920             exit(EXIT_FAILURE);
921         }
922     }
923 
924     if (tlscredsid) {
925         if (sockpath) {
926             error_report("TLS is only supported with IPv4/IPv6");
927             exit(EXIT_FAILURE);
928         }
929         if (device) {
930             error_report("TLS is not supported with a host device");
931             exit(EXIT_FAILURE);
932         }
933         if (tlsauthz && list) {
934             error_report("TLS authorization is incompatible with export list");
935             exit(EXIT_FAILURE);
936         }
937         tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
938         if (local_err) {
939             error_report("Failed to get TLS creds %s",
940                          error_get_pretty(local_err));
941             exit(EXIT_FAILURE);
942         }
943     } else {
944         if (tlsauthz) {
945             error_report("--tls-authz is not permitted without --tls-creds");
946             exit(EXIT_FAILURE);
947         }
948     }
949 
950     if (list) {
951         saddr = nbd_build_socket_address(sockpath, bindto, port);
952         return qemu_nbd_client_list(saddr, tlscreds, bindto);
953     }
954 
955 #if !HAVE_NBD_DEVICE
956     if (disconnect || device) {
957         error_report("Kernel /dev/nbdN support not available");
958         exit(EXIT_FAILURE);
959     }
960 #else /* HAVE_NBD_DEVICE */
961     if (disconnect) {
962         int nbdfd = open(argv[optind], O_RDWR);
963         if (nbdfd < 0) {
964             error_report("Cannot open %s: %s", argv[optind],
965                          strerror(errno));
966             exit(EXIT_FAILURE);
967         }
968         nbd_disconnect(nbdfd);
969 
970         close(nbdfd);
971 
972         printf("%s disconnected\n", argv[optind]);
973 
974         return 0;
975     }
976 #endif
977 
978     if ((device && !verbose) || fork_process) {
979         int stderr_fd[2];
980         pid_t pid;
981         int ret;
982 
983         if (qemu_pipe(stderr_fd) < 0) {
984             error_report("Error setting up communication pipe: %s",
985                          strerror(errno));
986             exit(EXIT_FAILURE);
987         }
988 
989         /* Now daemonize, but keep a communication channel open to
990          * print errors and exit with the proper status code.
991          */
992         pid = fork();
993         if (pid < 0) {
994             error_report("Failed to fork: %s", strerror(errno));
995             exit(EXIT_FAILURE);
996         } else if (pid == 0) {
997             close(stderr_fd[0]);
998             ret = qemu_daemon(1, 0);
999 
1000             /* Temporarily redirect stderr to the parent's pipe...  */
1001             old_stderr = dup(STDERR_FILENO);
1002             dup2(stderr_fd[1], STDERR_FILENO);
1003             if (ret < 0) {
1004                 error_report("Failed to daemonize: %s", strerror(errno));
1005                 exit(EXIT_FAILURE);
1006             }
1007 
1008             /* ... close the descriptor we inherited and go on.  */
1009             close(stderr_fd[1]);
1010         } else {
1011             bool errors = false;
1012             char *buf;
1013 
1014             /* In the parent.  Print error messages from the child until
1015              * it closes the pipe.
1016              */
1017             close(stderr_fd[1]);
1018             buf = g_malloc(1024);
1019             while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
1020                 errors = true;
1021                 ret = qemu_write_full(STDERR_FILENO, buf, ret);
1022                 if (ret < 0) {
1023                     exit(EXIT_FAILURE);
1024                 }
1025             }
1026             if (ret < 0) {
1027                 error_report("Cannot read from daemon: %s",
1028                              strerror(errno));
1029                 exit(EXIT_FAILURE);
1030             }
1031 
1032             /* Usually the daemon should not print any message.
1033              * Exit with zero status in that case.
1034              */
1035             exit(errors);
1036         }
1037     }
1038 
1039     if (device != NULL && sockpath == NULL) {
1040         sockpath = g_malloc(128);
1041         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
1042     }
1043 
1044     server = qio_net_listener_new();
1045     if (socket_activation == 0) {
1046         saddr = nbd_build_socket_address(sockpath, bindto, port);
1047         if (qio_net_listener_open_sync(server, saddr, &local_err) < 0) {
1048             object_unref(OBJECT(server));
1049             error_report_err(local_err);
1050             exit(EXIT_FAILURE);
1051         }
1052     } else {
1053         size_t i;
1054         /* See comment in check_socket_activation above. */
1055         for (i = 0; i < socket_activation; i++) {
1056             QIOChannelSocket *sioc;
1057             sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
1058                                              &local_err);
1059             if (sioc == NULL) {
1060                 object_unref(OBJECT(server));
1061                 error_report("Failed to use socket activation: %s",
1062                              error_get_pretty(local_err));
1063                 exit(EXIT_FAILURE);
1064             }
1065             qio_net_listener_add(server, sioc);
1066             object_unref(OBJECT(sioc));
1067         }
1068     }
1069 
1070     if (qemu_init_main_loop(&local_err)) {
1071         error_report_err(local_err);
1072         exit(EXIT_FAILURE);
1073     }
1074     bdrv_init();
1075     atexit(qemu_nbd_shutdown);
1076 
1077     srcpath = argv[optind];
1078     if (imageOpts) {
1079         QemuOpts *opts;
1080         if (fmt) {
1081             error_report("--image-opts and -f are mutually exclusive");
1082             exit(EXIT_FAILURE);
1083         }
1084         opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
1085         if (!opts) {
1086             qemu_opts_reset(&file_opts);
1087             exit(EXIT_FAILURE);
1088         }
1089         options = qemu_opts_to_qdict(opts, NULL);
1090         qemu_opts_reset(&file_opts);
1091         blk = blk_new_open(NULL, NULL, options, flags, &local_err);
1092     } else {
1093         if (fmt) {
1094             options = qdict_new();
1095             qdict_put_str(options, "driver", fmt);
1096         }
1097         blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
1098     }
1099 
1100     if (!blk) {
1101         error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
1102                           argv[optind]);
1103         exit(EXIT_FAILURE);
1104     }
1105     bs = blk_bs(blk);
1106 
1107     blk_set_enable_write_cache(blk, !writethrough);
1108 
1109     if (sn_opts) {
1110         ret = bdrv_snapshot_load_tmp(bs,
1111                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1112                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1113                                      &local_err);
1114     } else if (sn_id_or_name) {
1115         ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
1116                                                    &local_err);
1117     }
1118     if (ret < 0) {
1119         error_reportf_err(local_err, "Failed to load snapshot: ");
1120         exit(EXIT_FAILURE);
1121     }
1122 
1123     bs->detect_zeroes = detect_zeroes;
1124     fd_size = blk_getlength(blk);
1125     if (fd_size < 0) {
1126         error_report("Failed to determine the image length: %s",
1127                      strerror(-fd_size));
1128         exit(EXIT_FAILURE);
1129     }
1130 
1131     if (dev_offset >= fd_size) {
1132         error_report("Offset (%" PRIu64 ") has to be smaller than the image "
1133                      "size (%" PRId64 ")", dev_offset, fd_size);
1134         exit(EXIT_FAILURE);
1135     }
1136     fd_size -= dev_offset;
1137 
1138     if (partition) {
1139         uint64_t limit;
1140 
1141         if (dev_offset) {
1142             error_report("Cannot request partition and offset together");
1143             exit(EXIT_FAILURE);
1144         }
1145         ret = find_partition(blk, partition, &dev_offset, &limit);
1146         if (ret < 0) {
1147             error_report("Could not find partition %d: %s", partition,
1148                          strerror(-ret));
1149             exit(EXIT_FAILURE);
1150         }
1151         /*
1152          * MBR partition limits are (32-bit << 9); this assert lets
1153          * the compiler know that we can't overflow 64 bits.
1154          */
1155         assert(dev_offset + limit >= dev_offset);
1156         if (dev_offset + limit > fd_size) {
1157             error_report("Discovered partition %d at offset %" PRIu64
1158                          " size %" PRIu64 ", but size exceeds file length %"
1159                          PRId64, partition, dev_offset, limit, fd_size);
1160             exit(EXIT_FAILURE);
1161         }
1162         fd_size = limit;
1163     }
1164 
1165     export = nbd_export_new(bs, dev_offset, fd_size, export_name,
1166                             export_description, bitmap, nbdflags,
1167                             nbd_export_closed, writethrough, NULL,
1168                             &error_fatal);
1169 
1170     if (device) {
1171 #if HAVE_NBD_DEVICE
1172         int ret;
1173 
1174         ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
1175         if (ret != 0) {
1176             error_report("Failed to create client thread: %s", strerror(ret));
1177             exit(EXIT_FAILURE);
1178         }
1179 #endif
1180     } else {
1181         /* Shut up GCC warnings.  */
1182         memset(&client_thread, 0, sizeof(client_thread));
1183     }
1184 
1185     nbd_update_server_watch();
1186 
1187     /* now when the initialization is (almost) complete, chdir("/")
1188      * to free any busy filesystems */
1189     if (chdir("/") < 0) {
1190         error_report("Could not chdir to root directory: %s",
1191                      strerror(errno));
1192         exit(EXIT_FAILURE);
1193     }
1194 
1195     if (fork_process) {
1196         dup2(old_stderr, STDERR_FILENO);
1197         close(old_stderr);
1198     }
1199 
1200     state = RUNNING;
1201     do {
1202         main_loop_wait(false);
1203         if (state == TERMINATE) {
1204             state = TERMINATING;
1205             nbd_export_close(export);
1206             nbd_export_put(export);
1207             export = NULL;
1208         }
1209     } while (state != TERMINATED);
1210 
1211     blk_unref(blk);
1212     if (sockpath) {
1213         unlink(sockpath);
1214     }
1215 
1216     qemu_opts_del(sn_opts);
1217 
1218     if (device) {
1219         void *ret;
1220         pthread_join(client_thread, &ret);
1221         exit(ret != NULL);
1222     } else {
1223         exit(EXIT_SUCCESS);
1224     }
1225 }
1226