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ui: Clean up local variable shadowing
[qemu/kevin.git] / nbd / server.c
blob7a6f95071f8065858b1bcfcbcd6bcdbe4c109bb3
1 /*
2 * Copyright Red Hat
3 * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
4 *
5 * Network Block Device Server Side
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; under version 2 of the License.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include "qemu/osdep.h"
21
22 #include "block/block_int.h"
23 #include "block/export.h"
24 #include "block/dirty-bitmap.h"
25 #include "qapi/error.h"
26 #include "qemu/queue.h"
27 #include "trace.h"
28 #include "nbd-internal.h"
29 #include "qemu/units.h"
30 #include "qemu/memalign.h"
31
32 #define NBD_META_ID_BASE_ALLOCATION 0
33 #define NBD_META_ID_ALLOCATION_DEPTH 1
34 /* Dirty bitmaps use 'NBD_META_ID_DIRTY_BITMAP + i', so keep this id last. */
35 #define NBD_META_ID_DIRTY_BITMAP 2
36
37 /*
38 * NBD_MAX_BLOCK_STATUS_EXTENTS: 1 MiB of extents data. An empirical
39 * constant. If an increase is needed, note that the NBD protocol
40 * recommends no larger than 32 mb, so that the client won't consider
41 * the reply as a denial of service attack.
42 */
43 #define NBD_MAX_BLOCK_STATUS_EXTENTS (1 * MiB / 8)
44
45 static int system_errno_to_nbd_errno(int err)
46 {
47 switch (err) {
48 case 0:
49 return NBD_SUCCESS;
50 case EPERM:
51 case EROFS:
52 return NBD_EPERM;
53 case EIO:
54 return NBD_EIO;
55 case ENOMEM:
56 return NBD_ENOMEM;
57 #ifdef EDQUOT
58 case EDQUOT:
59 #endif
60 case EFBIG:
61 case ENOSPC:
62 return NBD_ENOSPC;
63 case EOVERFLOW:
64 return NBD_EOVERFLOW;
65 case ENOTSUP:
66 #if ENOTSUP != EOPNOTSUPP
67 case EOPNOTSUPP:
68 #endif
69 return NBD_ENOTSUP;
70 case ESHUTDOWN:
71 return NBD_ESHUTDOWN;
72 case EINVAL:
73 default:
74 return NBD_EINVAL;
75 }
76 }
77
78 /* Definitions for opaque data types */
79
80 typedef struct NBDRequestData NBDRequestData;
81
82 struct NBDRequestData {
83 NBDClient *client;
84 uint8_t *data;
85 bool complete;
86 };
87
88 struct NBDExport {
89 BlockExport common;
90
91 char *name;
92 char *description;
93 uint64_t size;
94 uint16_t nbdflags;
95 QTAILQ_HEAD(, NBDClient) clients;
96 QTAILQ_ENTRY(NBDExport) next;
97
98 BlockBackend *eject_notifier_blk;
99 Notifier eject_notifier;
100
101 bool allocation_depth;
102 BdrvDirtyBitmap **export_bitmaps;
103 size_t nr_export_bitmaps;
104 };
105
106 static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
107
108 /* NBDExportMetaContexts represents a list of contexts to be exported,
109 * as selected by NBD_OPT_SET_META_CONTEXT. Also used for
110 * NBD_OPT_LIST_META_CONTEXT. */
111 typedef struct NBDExportMetaContexts {
112 NBDExport *exp;
113 size_t count; /* number of negotiated contexts */
114 bool base_allocation; /* export base:allocation context (block status) */
115 bool allocation_depth; /* export qemu:allocation-depth */
116 bool *bitmaps; /*
117 * export qemu:dirty-bitmap:<export bitmap name>,
118 * sized by exp->nr_export_bitmaps
119 */
120 } NBDExportMetaContexts;
121
122 struct NBDClient {
123 int refcount;
124 void (*close_fn)(NBDClient *client, bool negotiated);
125
126 NBDExport *exp;
127 QCryptoTLSCreds *tlscreds;
128 char *tlsauthz;
129 QIOChannelSocket *sioc; /* The underlying data channel */
130 QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
131
132 Coroutine *recv_coroutine;
133
134 CoMutex send_lock;
135 Coroutine *send_coroutine;
136
137 bool read_yielding;
138 bool quiescing;
139
140 QTAILQ_ENTRY(NBDClient) next;
141 int nb_requests;
142 bool closing;
143
144 uint32_t check_align; /* If non-zero, check for aligned client requests */
145
146 NBDMode mode;
147 NBDExportMetaContexts export_meta;
148
149 uint32_t opt; /* Current option being negotiated */
150 uint32_t optlen; /* remaining length of data in ioc for the option being
151 negotiated now */
152 };
153
154 static void nbd_client_receive_next_request(NBDClient *client);
155
156 /* Basic flow for negotiation
157
158 Server Client
159 Negotiate
160
161 or
162
163 Server Client
164 Negotiate #1
165 Option
166 Negotiate #2
167
168 ----
169
170 followed by
171
172 Server Client
173 Request
174 Response
175 Request
176 Response
177 ...
178 ...
179 Request (type == 2)
180
181 */
182
183 static inline void set_be_option_rep(NBDOptionReply *rep, uint32_t option,
184 uint32_t type, uint32_t length)
185 {
186 stq_be_p(&rep->magic, NBD_REP_MAGIC);
187 stl_be_p(&rep->option, option);
188 stl_be_p(&rep->type, type);
189 stl_be_p(&rep->length, length);
190 }
191
192 /* Send a reply header, including length, but no payload.
193 * Return -errno on error, 0 on success. */
194 static int nbd_negotiate_send_rep_len(NBDClient *client, uint32_t type,
195 uint32_t len, Error **errp)
196 {
197 NBDOptionReply rep;
198
199 trace_nbd_negotiate_send_rep_len(client->opt, nbd_opt_lookup(client->opt),
200 type, nbd_rep_lookup(type), len);
201
202 assert(len < NBD_MAX_BUFFER_SIZE);
203
204 set_be_option_rep(&rep, client->opt, type, len);
205 return nbd_write(client->ioc, &rep, sizeof(rep), errp);
206 }
207
208 /* Send a reply header with default 0 length.
209 * Return -errno on error, 0 on success. */
210 static int nbd_negotiate_send_rep(NBDClient *client, uint32_t type,
211 Error **errp)
212 {
213 return nbd_negotiate_send_rep_len(client, type, 0, errp);
214 }
215
216 /* Send an error reply.
217 * Return -errno on error, 0 on success. */
218 static int G_GNUC_PRINTF(4, 0)
219 nbd_negotiate_send_rep_verr(NBDClient *client, uint32_t type,
220 Error **errp, const char *fmt, va_list va)
221 {
222 ERRP_GUARD();
223 g_autofree char *msg = NULL;
224 int ret;
225 size_t len;
226
227 msg = g_strdup_vprintf(fmt, va);
228 len = strlen(msg);
229 assert(len < NBD_MAX_STRING_SIZE);
230 trace_nbd_negotiate_send_rep_err(msg);
231 ret = nbd_negotiate_send_rep_len(client, type, len, errp);
232 if (ret < 0) {
233 return ret;
234 }
235 if (nbd_write(client->ioc, msg, len, errp) < 0) {
236 error_prepend(errp, "write failed (error message): ");
237 return -EIO;
238 }
239
240 return 0;
241 }
242
243 /*
244 * Return a malloc'd copy of @name suitable for use in an error reply.
245 */
246 static char *
247 nbd_sanitize_name(const char *name)
248 {
249 if (strnlen(name, 80) < 80) {
250 return g_strdup(name);
251 }
252 /* XXX Should we also try to sanitize any control characters? */
253 return g_strdup_printf("%.80s...", name);
254 }
255
256 /* Send an error reply.
257 * Return -errno on error, 0 on success. */
258 static int G_GNUC_PRINTF(4, 5)
259 nbd_negotiate_send_rep_err(NBDClient *client, uint32_t type,
260 Error **errp, const char *fmt, ...)
261 {
262 va_list va;
263 int ret;
264
265 va_start(va, fmt);
266 ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va);
267 va_end(va);
268 return ret;
269 }
270
271 /* Drop remainder of the current option, and send a reply with the
272 * given error type and message. Return -errno on read or write
273 * failure; or 0 if connection is still live. */
274 static int G_GNUC_PRINTF(4, 0)
275 nbd_opt_vdrop(NBDClient *client, uint32_t type, Error **errp,
276 const char *fmt, va_list va)
277 {
278 int ret = nbd_drop(client->ioc, client->optlen, errp);
279
280 client->optlen = 0;
281 if (!ret) {
282 ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va);
283 }
284 return ret;
285 }
286
287 static int G_GNUC_PRINTF(4, 5)
288 nbd_opt_drop(NBDClient *client, uint32_t type, Error **errp,
289 const char *fmt, ...)
290 {
291 int ret;
292 va_list va;
293
294 va_start(va, fmt);
295 ret = nbd_opt_vdrop(client, type, errp, fmt, va);
296 va_end(va);
297
298 return ret;
299 }
300
301 static int G_GNUC_PRINTF(3, 4)
302 nbd_opt_invalid(NBDClient *client, Error **errp, const char *fmt, ...)
303 {
304 int ret;
305 va_list va;
306
307 va_start(va, fmt);
308 ret = nbd_opt_vdrop(client, NBD_REP_ERR_INVALID, errp, fmt, va);
309 va_end(va);
310
311 return ret;
312 }
313
314 /* Read size bytes from the unparsed payload of the current option.
315 * If @check_nul, require that no NUL bytes appear in buffer.
316 * Return -errno on I/O error, 0 if option was completely handled by
317 * sending a reply about inconsistent lengths, or 1 on success. */
318 static int nbd_opt_read(NBDClient *client, void *buffer, size_t size,
319 bool check_nul, Error **errp)
320 {
321 if (size > client->optlen) {
322 return nbd_opt_invalid(client, errp,
323 "Inconsistent lengths in option %s",
324 nbd_opt_lookup(client->opt));
325 }
326 client->optlen -= size;
327 if (qio_channel_read_all(client->ioc, buffer, size, errp) < 0) {
328 return -EIO;
329 }
330
331 if (check_nul && strnlen(buffer, size) != size) {
332 return nbd_opt_invalid(client, errp,
333 "Unexpected embedded NUL in option %s",
334 nbd_opt_lookup(client->opt));
335 }
336 return 1;
337 }
338
339 /* Drop size bytes from the unparsed payload of the current option.
340 * Return -errno on I/O error, 0 if option was completely handled by
341 * sending a reply about inconsistent lengths, or 1 on success. */
342 static int nbd_opt_skip(NBDClient *client, size_t size, Error **errp)
343 {
344 if (size > client->optlen) {
345 return nbd_opt_invalid(client, errp,
346 "Inconsistent lengths in option %s",
347 nbd_opt_lookup(client->opt));
348 }
349 client->optlen -= size;
350 return nbd_drop(client->ioc, size, errp) < 0 ? -EIO : 1;
351 }
352
353 /* nbd_opt_read_name
354 *
355 * Read a string with the format:
356 * uint32_t len (<= NBD_MAX_STRING_SIZE)
357 * len bytes string (not 0-terminated)
358 *
359 * On success, @name will be allocated.
360 * If @length is non-null, it will be set to the actual string length.
361 *
362 * Return -errno on I/O error, 0 if option was completely handled by
363 * sending a reply about inconsistent lengths, or 1 on success.
364 */
365 static int nbd_opt_read_name(NBDClient *client, char **name, uint32_t *length,
366 Error **errp)
367 {
368 int ret;
369 uint32_t len;
370 g_autofree char *local_name = NULL;
371
372 *name = NULL;
373 ret = nbd_opt_read(client, &len, sizeof(len), false, errp);
374 if (ret <= 0) {
375 return ret;
376 }
377 len = cpu_to_be32(len);
378
379 if (len > NBD_MAX_STRING_SIZE) {
380 return nbd_opt_invalid(client, errp,
381 "Invalid name length: %" PRIu32, len);
382 }
383
384 local_name = g_malloc(len + 1);
385 ret = nbd_opt_read(client, local_name, len, true, errp);
386 if (ret <= 0) {
387 return ret;
388 }
389 local_name[len] = '\0';
390
391 if (length) {
392 *length = len;
393 }
394 *name = g_steal_pointer(&local_name);
395
396 return 1;
397 }
398
399 /* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload.
400 * Return -errno on error, 0 on success. */
401 static int nbd_negotiate_send_rep_list(NBDClient *client, NBDExport *exp,
402 Error **errp)
403 {
404 ERRP_GUARD();
405 size_t name_len, desc_len;
406 uint32_t len;
407 const char *name = exp->name ? exp->name : "";
408 const char *desc = exp->description ? exp->description : "";
409 QIOChannel *ioc = client->ioc;
410 int ret;
411
412 trace_nbd_negotiate_send_rep_list(name, desc);
413 name_len = strlen(name);
414 desc_len = strlen(desc);
415 assert(name_len <= NBD_MAX_STRING_SIZE && desc_len <= NBD_MAX_STRING_SIZE);
416 len = name_len + desc_len + sizeof(len);
417 ret = nbd_negotiate_send_rep_len(client, NBD_REP_SERVER, len, errp);
418 if (ret < 0) {
419 return ret;
420 }
421
422 len = cpu_to_be32(name_len);
423 if (nbd_write(ioc, &len, sizeof(len), errp) < 0) {
424 error_prepend(errp, "write failed (name length): ");
425 return -EINVAL;
426 }
427
428 if (nbd_write(ioc, name, name_len, errp) < 0) {
429 error_prepend(errp, "write failed (name buffer): ");
430 return -EINVAL;
431 }
432
433 if (nbd_write(ioc, desc, desc_len, errp) < 0) {
434 error_prepend(errp, "write failed (description buffer): ");
435 return -EINVAL;
436 }
437
438 return 0;
439 }
440
441 /* Process the NBD_OPT_LIST command, with a potential series of replies.
442 * Return -errno on error, 0 on success. */
443 static int nbd_negotiate_handle_list(NBDClient *client, Error **errp)
444 {
445 NBDExport *exp;
446 assert(client->opt == NBD_OPT_LIST);
447
448 /* For each export, send a NBD_REP_SERVER reply. */
449 QTAILQ_FOREACH(exp, &exports, next) {
450 if (nbd_negotiate_send_rep_list(client, exp, errp)) {
451 return -EINVAL;
452 }
453 }
454 /* Finish with a NBD_REP_ACK. */
455 return nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
456 }
457
458 static void nbd_check_meta_export(NBDClient *client)
459 {
460 if (client->exp != client->export_meta.exp) {
461 client->export_meta.count = 0;
462 }
463 }
464
465 /* Send a reply to NBD_OPT_EXPORT_NAME.
466 * Return -errno on error, 0 on success. */
467 static int nbd_negotiate_handle_export_name(NBDClient *client, bool no_zeroes,
468 Error **errp)
469 {
470 ERRP_GUARD();
471 g_autofree char *name = NULL;
472 char buf[NBD_REPLY_EXPORT_NAME_SIZE] = "";
473 size_t len;
474 int ret;
475 uint16_t myflags;
476
477 /* Client sends:
478 [20 .. xx] export name (length bytes)
479 Server replies:
480 [ 0 .. 7] size
481 [ 8 .. 9] export flags
482 [10 .. 133] reserved (0) [unless no_zeroes]
483 */
484 trace_nbd_negotiate_handle_export_name();
485 if (client->optlen > NBD_MAX_STRING_SIZE) {
486 error_setg(errp, "Bad length received");
487 return -EINVAL;
488 }
489 name = g_malloc(client->optlen + 1);
490 if (nbd_read(client->ioc, name, client->optlen, "export name", errp) < 0) {
491 return -EIO;
492 }
493 name[client->optlen] = '\0';
494 client->optlen = 0;
495
496 trace_nbd_negotiate_handle_export_name_request(name);
497
498 client->exp = nbd_export_find(name);
499 if (!client->exp) {
500 error_setg(errp, "export not found");
501 return -EINVAL;
502 }
503
504 myflags = client->exp->nbdflags;
505 if (client->mode >= NBD_MODE_STRUCTURED) {
506 myflags |= NBD_FLAG_SEND_DF;
507 }
508 trace_nbd_negotiate_new_style_size_flags(client->exp->size, myflags);
509 stq_be_p(buf, client->exp->size);
510 stw_be_p(buf + 8, myflags);
511 len = no_zeroes ? 10 : sizeof(buf);
512 ret = nbd_write(client->ioc, buf, len, errp);
513 if (ret < 0) {
514 error_prepend(errp, "write failed: ");
515 return ret;
516 }
517
518 QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
519 blk_exp_ref(&client->exp->common);
520 nbd_check_meta_export(client);
521
522 return 0;
523 }
524
525 /* Send a single NBD_REP_INFO, with a buffer @buf of @length bytes.
526 * The buffer does NOT include the info type prefix.
527 * Return -errno on error, 0 if ready to send more. */
528 static int nbd_negotiate_send_info(NBDClient *client,
529 uint16_t info, uint32_t length, void *buf,
530 Error **errp)
531 {
532 int rc;
533
534 trace_nbd_negotiate_send_info(info, nbd_info_lookup(info), length);
535 rc = nbd_negotiate_send_rep_len(client, NBD_REP_INFO,
536 sizeof(info) + length, errp);
537 if (rc < 0) {
538 return rc;
539 }
540 info = cpu_to_be16(info);
541 if (nbd_write(client->ioc, &info, sizeof(info), errp) < 0) {
542 return -EIO;
543 }
544 if (nbd_write(client->ioc, buf, length, errp) < 0) {
545 return -EIO;
546 }
547 return 0;
548 }
549
550 /* nbd_reject_length: Handle any unexpected payload.
551 * @fatal requests that we quit talking to the client, even if we are able
552 * to successfully send an error reply.
553 * Return:
554 * -errno transmission error occurred or @fatal was requested, errp is set
555 * 0 error message successfully sent to client, errp is not set
556 */
557 static int nbd_reject_length(NBDClient *client, bool fatal, Error **errp)
558 {
559 int ret;
560
561 assert(client->optlen);
562 ret = nbd_opt_invalid(client, errp, "option '%s' has unexpected length",
563 nbd_opt_lookup(client->opt));
564 if (fatal && !ret) {
565 error_setg(errp, "option '%s' has unexpected length",
566 nbd_opt_lookup(client->opt));
567 return -EINVAL;
568 }
569 return ret;
570 }
571
572 /* Handle NBD_OPT_INFO and NBD_OPT_GO.
573 * Return -errno on error, 0 if ready for next option, and 1 to move
574 * into transmission phase. */
575 static int nbd_negotiate_handle_info(NBDClient *client, Error **errp)
576 {
577 int rc;
578 g_autofree char *name = NULL;
579 NBDExport *exp;
580 uint16_t requests;
581 uint16_t request;
582 uint32_t namelen = 0;
583 bool sendname = false;
584 bool blocksize = false;
585 uint32_t sizes[3];
586 char buf[sizeof(uint64_t) + sizeof(uint16_t)];
587 uint32_t check_align = 0;
588 uint16_t myflags;
589
590 /* Client sends:
591 4 bytes: L, name length (can be 0)
592 L bytes: export name
593 2 bytes: N, number of requests (can be 0)
594 N * 2 bytes: N requests
595 */
596 rc = nbd_opt_read_name(client, &name, &namelen, errp);
597 if (rc <= 0) {
598 return rc;
599 }
600 trace_nbd_negotiate_handle_export_name_request(name);
601
602 rc = nbd_opt_read(client, &requests, sizeof(requests), false, errp);
603 if (rc <= 0) {
604 return rc;
605 }
606 requests = be16_to_cpu(requests);
607 trace_nbd_negotiate_handle_info_requests(requests);
608 while (requests--) {
609 rc = nbd_opt_read(client, &request, sizeof(request), false, errp);
610 if (rc <= 0) {
611 return rc;
612 }
613 request = be16_to_cpu(request);
614 trace_nbd_negotiate_handle_info_request(request,
615 nbd_info_lookup(request));
616 /* We care about NBD_INFO_NAME and NBD_INFO_BLOCK_SIZE;
617 * everything else is either a request we don't know or
618 * something we send regardless of request */
619 switch (request) {
620 case NBD_INFO_NAME:
621 sendname = true;
622 break;
623 case NBD_INFO_BLOCK_SIZE:
624 blocksize = true;
625 break;
626 }
627 }
628 if (client->optlen) {
629 return nbd_reject_length(client, false, errp);
630 }
631
632 exp = nbd_export_find(name);
633 if (!exp) {
634 g_autofree char *sane_name = nbd_sanitize_name(name);
635
636 return nbd_negotiate_send_rep_err(client, NBD_REP_ERR_UNKNOWN,
637 errp, "export '%s' not present",
638 sane_name);
639 }
640
641 /* Don't bother sending NBD_INFO_NAME unless client requested it */
642 if (sendname) {
643 rc = nbd_negotiate_send_info(client, NBD_INFO_NAME, namelen, name,
644 errp);
645 if (rc < 0) {
646 return rc;
647 }
648 }
649
650 /* Send NBD_INFO_DESCRIPTION only if available, regardless of
651 * client request */
652 if (exp->description) {
653 size_t len = strlen(exp->description);
654
655 assert(len <= NBD_MAX_STRING_SIZE);
656 rc = nbd_negotiate_send_info(client, NBD_INFO_DESCRIPTION,
657 len, exp->description, errp);
658 if (rc < 0) {
659 return rc;
660 }
661 }
662
663 /* Send NBD_INFO_BLOCK_SIZE always, but tweak the minimum size
664 * according to whether the client requested it, and according to
665 * whether this is OPT_INFO or OPT_GO. */
666 /* minimum - 1 for back-compat, or actual if client will obey it. */
667 if (client->opt == NBD_OPT_INFO || blocksize) {
668 check_align = sizes[0] = blk_get_request_alignment(exp->common.blk);
669 } else {
670 sizes[0] = 1;
671 }
672 assert(sizes[0] <= NBD_MAX_BUFFER_SIZE);
673 /* preferred - Hard-code to 4096 for now.
674 * TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */
675 sizes[1] = MAX(4096, sizes[0]);
676 /* maximum - At most 32M, but smaller as appropriate. */
677 sizes[2] = MIN(blk_get_max_transfer(exp->common.blk), NBD_MAX_BUFFER_SIZE);
678 trace_nbd_negotiate_handle_info_block_size(sizes[0], sizes[1], sizes[2]);
679 sizes[0] = cpu_to_be32(sizes[0]);
680 sizes[1] = cpu_to_be32(sizes[1]);
681 sizes[2] = cpu_to_be32(sizes[2]);
682 rc = nbd_negotiate_send_info(client, NBD_INFO_BLOCK_SIZE,
683 sizeof(sizes), sizes, errp);
684 if (rc < 0) {
685 return rc;
686 }
687
688 /* Send NBD_INFO_EXPORT always */
689 myflags = exp->nbdflags;
690 if (client->mode >= NBD_MODE_STRUCTURED) {
691 myflags |= NBD_FLAG_SEND_DF;
692 }
693 trace_nbd_negotiate_new_style_size_flags(exp->size, myflags);
694 stq_be_p(buf, exp->size);
695 stw_be_p(buf + 8, myflags);
696 rc = nbd_negotiate_send_info(client, NBD_INFO_EXPORT,
697 sizeof(buf), buf, errp);
698 if (rc < 0) {
699 return rc;
700 }
701
702 /*
703 * If the client is just asking for NBD_OPT_INFO, but forgot to
704 * request block sizes in a situation that would impact
705 * performance, then return an error. But for NBD_OPT_GO, we
706 * tolerate all clients, regardless of alignments.
707 */
708 if (client->opt == NBD_OPT_INFO && !blocksize &&
709 blk_get_request_alignment(exp->common.blk) > 1) {
710 return nbd_negotiate_send_rep_err(client,
711 NBD_REP_ERR_BLOCK_SIZE_REQD,
712 errp,
713 "request NBD_INFO_BLOCK_SIZE to "
714 "use this export");
715 }
716
717 /* Final reply */
718 rc = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
719 if (rc < 0) {
720 return rc;
721 }
722
723 if (client->opt == NBD_OPT_GO) {
724 client->exp = exp;
725 client->check_align = check_align;
726 QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
727 blk_exp_ref(&client->exp->common);
728 nbd_check_meta_export(client);
729 rc = 1;
730 }
731 return rc;
732 }
733
734
735 /* Handle NBD_OPT_STARTTLS. Return NULL to drop connection, or else the
736 * new channel for all further (now-encrypted) communication. */
737 static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client,
738 Error **errp)
739 {
740 QIOChannel *ioc;
741 QIOChannelTLS *tioc;
742 struct NBDTLSHandshakeData data = { 0 };
743
744 assert(client->opt == NBD_OPT_STARTTLS);
745
746 trace_nbd_negotiate_handle_starttls();
747 ioc = client->ioc;
748
749 if (nbd_negotiate_send_rep(client, NBD_REP_ACK, errp) < 0) {
750 return NULL;
751 }
752
753 tioc = qio_channel_tls_new_server(ioc,
754 client->tlscreds,
755 client->tlsauthz,
756 errp);
757 if (!tioc) {
758 return NULL;
759 }
760
761 qio_channel_set_name(QIO_CHANNEL(tioc), "nbd-server-tls");
762 trace_nbd_negotiate_handle_starttls_handshake();
763 data.loop = g_main_loop_new(g_main_context_default(), FALSE);
764 qio_channel_tls_handshake(tioc,
765 nbd_tls_handshake,
766 &data,
767 NULL,
768 NULL);
769
770 if (!data.complete) {
771 g_main_loop_run(data.loop);
772 }
773 g_main_loop_unref(data.loop);
774 if (data.error) {
775 object_unref(OBJECT(tioc));
776 error_propagate(errp, data.error);
777 return NULL;
778 }
779
780 return QIO_CHANNEL(tioc);
781 }
782
783 /* nbd_negotiate_send_meta_context
784 *
785 * Send one chunk of reply to NBD_OPT_{LIST,SET}_META_CONTEXT
786 *
787 * For NBD_OPT_LIST_META_CONTEXT @context_id is ignored, 0 is used instead.
788 */
789 static int nbd_negotiate_send_meta_context(NBDClient *client,
790 const char *context,
791 uint32_t context_id,
792 Error **errp)
793 {
794 NBDOptionReplyMetaContext opt;
795 struct iovec iov[] = {
796 {.iov_base = &opt, .iov_len = sizeof(opt)},
797 {.iov_base = (void *)context, .iov_len = strlen(context)}
798 };
799
800 assert(iov[1].iov_len <= NBD_MAX_STRING_SIZE);
801 if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
802 context_id = 0;
803 }
804
805 trace_nbd_negotiate_meta_query_reply(context, context_id);
806 set_be_option_rep(&opt.h, client->opt, NBD_REP_META_CONTEXT,
807 sizeof(opt) - sizeof(opt.h) + iov[1].iov_len);
808 stl_be_p(&opt.context_id, context_id);
809
810 return qio_channel_writev_all(client->ioc, iov, 2, errp) < 0 ? -EIO : 0;
811 }
812
813 /*
814 * Return true if @query matches @pattern, or if @query is empty when
815 * the @client is performing _LIST_.
816 */
817 static bool nbd_meta_empty_or_pattern(NBDClient *client, const char *pattern,
818 const char *query)
819 {
820 if (!*query) {
821 trace_nbd_negotiate_meta_query_parse("empty");
822 return client->opt == NBD_OPT_LIST_META_CONTEXT;
823 }
824 if (strcmp(query, pattern) == 0) {
825 trace_nbd_negotiate_meta_query_parse(pattern);
826 return true;
827 }
828 trace_nbd_negotiate_meta_query_skip("pattern not matched");
829 return false;
830 }
831
832 /*
833 * Return true and adjust @str in place if it begins with @prefix.
834 */
835 static bool nbd_strshift(const char **str, const char *prefix)
836 {
837 size_t len = strlen(prefix);
838
839 if (strncmp(*str, prefix, len) == 0) {
840 *str += len;
841 return true;
842 }
843 return false;
844 }
845
846 /* nbd_meta_base_query
847 *
848 * Handle queries to 'base' namespace. For now, only the base:allocation
849 * context is available. Return true if @query has been handled.
850 */
851 static bool nbd_meta_base_query(NBDClient *client, NBDExportMetaContexts *meta,
852 const char *query)
853 {
854 if (!nbd_strshift(&query, "base:")) {
855 return false;
856 }
857 trace_nbd_negotiate_meta_query_parse("base:");
858
859 if (nbd_meta_empty_or_pattern(client, "allocation", query)) {
860 meta->base_allocation = true;
861 }
862 return true;
863 }
864
865 /* nbd_meta_qemu_query
866 *
867 * Handle queries to 'qemu' namespace. For now, only the qemu:dirty-bitmap:
868 * and qemu:allocation-depth contexts are available. Return true if @query
869 * has been handled.
870 */
871 static bool nbd_meta_qemu_query(NBDClient *client, NBDExportMetaContexts *meta,
872 const char *query)
873 {
874 size_t i;
875
876 if (!nbd_strshift(&query, "qemu:")) {
877 return false;
878 }
879 trace_nbd_negotiate_meta_query_parse("qemu:");
880
881 if (!*query) {
882 if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
883 meta->allocation_depth = meta->exp->allocation_depth;
884 if (meta->exp->nr_export_bitmaps) {
885 memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps);
886 }
887 }
888 trace_nbd_negotiate_meta_query_parse("empty");
889 return true;
890 }
891
892 if (strcmp(query, "allocation-depth") == 0) {
893 trace_nbd_negotiate_meta_query_parse("allocation-depth");
894 meta->allocation_depth = meta->exp->allocation_depth;
895 return true;
896 }
897
898 if (nbd_strshift(&query, "dirty-bitmap:")) {
899 trace_nbd_negotiate_meta_query_parse("dirty-bitmap:");
900 if (!*query) {
901 if (client->opt == NBD_OPT_LIST_META_CONTEXT &&
902 meta->exp->nr_export_bitmaps) {
903 memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps);
904 }
905 trace_nbd_negotiate_meta_query_parse("empty");
906 return true;
907 }
908
909 for (i = 0; i < meta->exp->nr_export_bitmaps; i++) {
910 const char *bm_name;
911
912 bm_name = bdrv_dirty_bitmap_name(meta->exp->export_bitmaps[i]);
913 if (strcmp(bm_name, query) == 0) {
914 meta->bitmaps[i] = true;
915 trace_nbd_negotiate_meta_query_parse(query);
916 return true;
917 }
918 }
919 trace_nbd_negotiate_meta_query_skip("no dirty-bitmap match");
920 return true;
921 }
922
923 trace_nbd_negotiate_meta_query_skip("unknown qemu context");
924 return true;
925 }
926
927 /* nbd_negotiate_meta_query
928 *
929 * Parse namespace name and call corresponding function to parse body of the
930 * query.
931 *
932 * The only supported namespaces are 'base' and 'qemu'.
933 *
934 * Return -errno on I/O error, 0 if option was completely handled by
935 * sending a reply about inconsistent lengths, or 1 on success. */
936 static int nbd_negotiate_meta_query(NBDClient *client,
937 NBDExportMetaContexts *meta, Error **errp)
938 {
939 int ret;
940 g_autofree char *query = NULL;
941 uint32_t len;
942
943 ret = nbd_opt_read(client, &len, sizeof(len), false, errp);
944 if (ret <= 0) {
945 return ret;
946 }
947 len = cpu_to_be32(len);
948
949 if (len > NBD_MAX_STRING_SIZE) {
950 trace_nbd_negotiate_meta_query_skip("length too long");
951 return nbd_opt_skip(client, len, errp);
952 }
953
954 query = g_malloc(len + 1);
955 ret = nbd_opt_read(client, query, len, true, errp);
956 if (ret <= 0) {
957 return ret;
958 }
959 query[len] = '\0';
960
961 if (nbd_meta_base_query(client, meta, query)) {
962 return 1;
963 }
964 if (nbd_meta_qemu_query(client, meta, query)) {
965 return 1;
966 }
967
968 trace_nbd_negotiate_meta_query_skip("unknown namespace");
969 return 1;
970 }
971
972 /* nbd_negotiate_meta_queries
973 * Handle NBD_OPT_LIST_META_CONTEXT and NBD_OPT_SET_META_CONTEXT
974 *
975 * Return -errno on I/O error, or 0 if option was completely handled. */
976 static int nbd_negotiate_meta_queries(NBDClient *client,
977 NBDExportMetaContexts *meta, Error **errp)
978 {
979 int ret;
980 g_autofree char *export_name = NULL;
981 /* Mark unused to work around https://bugs.llvm.org/show_bug.cgi?id=3888 */
982 g_autofree G_GNUC_UNUSED bool *bitmaps = NULL;
983 NBDExportMetaContexts local_meta = {0};
984 uint32_t nb_queries;
985 size_t i;
986 size_t count = 0;
987
988 if (client->opt == NBD_OPT_SET_META_CONTEXT &&
989 client->mode < NBD_MODE_STRUCTURED) {
990 return nbd_opt_invalid(client, errp,
991 "request option '%s' when structured reply "
992 "is not negotiated",
993 nbd_opt_lookup(client->opt));
994 }
995
996 if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
997 /* Only change the caller's meta on SET. */
998 meta = &local_meta;
999 }
1000
1001 g_free(meta->bitmaps);
1002 memset(meta, 0, sizeof(*meta));
1003
1004 ret = nbd_opt_read_name(client, &export_name, NULL, errp);
1005 if (ret <= 0) {
1006 return ret;
1007 }
1008
1009 meta->exp = nbd_export_find(export_name);
1010 if (meta->exp == NULL) {
1011 g_autofree char *sane_name = nbd_sanitize_name(export_name);
1012
1013 return nbd_opt_drop(client, NBD_REP_ERR_UNKNOWN, errp,
1014 "export '%s' not present", sane_name);
1015 }
1016 meta->bitmaps = g_new0(bool, meta->exp->nr_export_bitmaps);
1017 if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
1018 bitmaps = meta->bitmaps;
1019 }
1020
1021 ret = nbd_opt_read(client, &nb_queries, sizeof(nb_queries), false, errp);
1022 if (ret <= 0) {
1023 return ret;
1024 }
1025 nb_queries = cpu_to_be32(nb_queries);
1026 trace_nbd_negotiate_meta_context(nbd_opt_lookup(client->opt),
1027 export_name, nb_queries);
1028
1029 if (client->opt == NBD_OPT_LIST_META_CONTEXT && !nb_queries) {
1030 /* enable all known contexts */
1031 meta->base_allocation = true;
1032 meta->allocation_depth = meta->exp->allocation_depth;
1033 if (meta->exp->nr_export_bitmaps) {
1034 memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps);
1035 }
1036 } else {
1037 for (i = 0; i < nb_queries; ++i) {
1038 ret = nbd_negotiate_meta_query(client, meta, errp);
1039 if (ret <= 0) {
1040 return ret;
1041 }
1042 }
1043 }
1044
1045 if (meta->base_allocation) {
1046 ret = nbd_negotiate_send_meta_context(client, "base:allocation",
1047 NBD_META_ID_BASE_ALLOCATION,
1048 errp);
1049 if (ret < 0) {
1050 return ret;
1051 }
1052 count++;
1053 }
1054
1055 if (meta->allocation_depth) {
1056 ret = nbd_negotiate_send_meta_context(client, "qemu:allocation-depth",
1057 NBD_META_ID_ALLOCATION_DEPTH,
1058 errp);
1059 if (ret < 0) {
1060 return ret;
1061 }
1062 count++;
1063 }
1064
1065 for (i = 0; i < meta->exp->nr_export_bitmaps; i++) {
1066 const char *bm_name;
1067 g_autofree char *context = NULL;
1068
1069 if (!meta->bitmaps[i]) {
1070 continue;
1071 }
1072
1073 bm_name = bdrv_dirty_bitmap_name(meta->exp->export_bitmaps[i]);
1074 context = g_strdup_printf("qemu:dirty-bitmap:%s", bm_name);
1075
1076 ret = nbd_negotiate_send_meta_context(client, context,
1077 NBD_META_ID_DIRTY_BITMAP + i,
1078 errp);
1079 if (ret < 0) {
1080 return ret;
1081 }
1082 count++;
1083 }
1084
1085 ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
1086 if (ret == 0) {
1087 meta->count = count;
1088 }
1089
1090 return ret;
1091 }
1092
1093 /* nbd_negotiate_options
1094 * Process all NBD_OPT_* client option commands, during fixed newstyle
1095 * negotiation.
1096 * Return:
1097 * -errno on error, errp is set
1098 * 0 on successful negotiation, errp is not set
1099 * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
1100 * errp is not set
1101 */
1102 static int nbd_negotiate_options(NBDClient *client, Error **errp)
1103 {
1104 uint32_t flags;
1105 bool fixedNewstyle = false;
1106 bool no_zeroes = false;
1107
1108 /* Client sends:
1109 [ 0 .. 3] client flags
1110
1111 Then we loop until NBD_OPT_EXPORT_NAME or NBD_OPT_GO:
1112 [ 0 .. 7] NBD_OPTS_MAGIC
1113 [ 8 .. 11] NBD option
1114 [12 .. 15] Data length
1115 ... Rest of request
1116
1117 [ 0 .. 7] NBD_OPTS_MAGIC
1118 [ 8 .. 11] Second NBD option
1119 [12 .. 15] Data length
1120 ... Rest of request
1121 */
1122
1123 if (nbd_read32(client->ioc, &flags, "flags", errp) < 0) {
1124 return -EIO;
1125 }
1126 client->mode = NBD_MODE_EXPORT_NAME;
1127 trace_nbd_negotiate_options_flags(flags);
1128 if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) {
1129 fixedNewstyle = true;
1130 flags &= ~NBD_FLAG_C_FIXED_NEWSTYLE;
1131 client->mode = NBD_MODE_SIMPLE;
1132 }
1133 if (flags & NBD_FLAG_C_NO_ZEROES) {
1134 no_zeroes = true;
1135 flags &= ~NBD_FLAG_C_NO_ZEROES;
1136 }
1137 if (flags != 0) {
1138 error_setg(errp, "Unknown client flags 0x%" PRIx32 " received", flags);
1139 return -EINVAL;
1140 }
1141
1142 while (1) {
1143 int ret;
1144 uint32_t option, length;
1145 uint64_t magic;
1146
1147 if (nbd_read64(client->ioc, &magic, "opts magic", errp) < 0) {
1148 return -EINVAL;
1149 }
1150 trace_nbd_negotiate_options_check_magic(magic);
1151 if (magic != NBD_OPTS_MAGIC) {
1152 error_setg(errp, "Bad magic received");
1153 return -EINVAL;
1154 }
1155
1156 if (nbd_read32(client->ioc, &option, "option", errp) < 0) {
1157 return -EINVAL;
1158 }
1159 client->opt = option;
1160
1161 if (nbd_read32(client->ioc, &length, "option length", errp) < 0) {
1162 return -EINVAL;
1163 }
1164 assert(!client->optlen);
1165 client->optlen = length;
1166
1167 if (length > NBD_MAX_BUFFER_SIZE) {
1168 error_setg(errp, "len (%" PRIu32 ") is larger than max len (%u)",
1169 length, NBD_MAX_BUFFER_SIZE);
1170 return -EINVAL;
1171 }
1172
1173 trace_nbd_negotiate_options_check_option(option,
1174 nbd_opt_lookup(option));
1175 if (client->tlscreds &&
1176 client->ioc == (QIOChannel *)client->sioc) {
1177 QIOChannel *tioc;
1178 if (!fixedNewstyle) {
1179 error_setg(errp, "Unsupported option 0x%" PRIx32, option);
1180 return -EINVAL;
1181 }
1182 switch (option) {
1183 case NBD_OPT_STARTTLS:
1184 if (length) {
1185 /* Unconditionally drop the connection if the client
1186 * can't start a TLS negotiation correctly */
1187 return nbd_reject_length(client, true, errp);
1188 }
1189 tioc = nbd_negotiate_handle_starttls(client, errp);
1190 if (!tioc) {
1191 return -EIO;
1192 }
1193 ret = 0;
1194 object_unref(OBJECT(client->ioc));
1195 client->ioc = tioc;
1196 break;
1197
1198 case NBD_OPT_EXPORT_NAME:
1199 /* No way to return an error to client, so drop connection */
1200 error_setg(errp, "Option 0x%x not permitted before TLS",
1201 option);
1202 return -EINVAL;
1203
1204 default:
1205 /* Let the client keep trying, unless they asked to
1206 * quit. Always try to give an error back to the
1207 * client; but when replying to OPT_ABORT, be aware
1208 * that the client may hang up before receiving the
1209 * error, in which case we are fine ignoring the
1210 * resulting EPIPE. */
1211 ret = nbd_opt_drop(client, NBD_REP_ERR_TLS_REQD,
1212 option == NBD_OPT_ABORT ? NULL : errp,
1213 "Option 0x%" PRIx32
1214 " not permitted before TLS", option);
1215 if (option == NBD_OPT_ABORT) {
1216 return 1;
1217 }
1218 break;
1219 }
1220 } else if (fixedNewstyle) {
1221 switch (option) {
1222 case NBD_OPT_LIST:
1223 if (length) {
1224 ret = nbd_reject_length(client, false, errp);
1225 } else {
1226 ret = nbd_negotiate_handle_list(client, errp);
1227 }
1228 break;
1229
1230 case NBD_OPT_ABORT:
1231 /* NBD spec says we must try to reply before
1232 * disconnecting, but that we must also tolerate
1233 * guests that don't wait for our reply. */
1234 nbd_negotiate_send_rep(client, NBD_REP_ACK, NULL);
1235 return 1;
1236
1237 case NBD_OPT_EXPORT_NAME:
1238 return nbd_negotiate_handle_export_name(client, no_zeroes,
1239 errp);
1240
1241 case NBD_OPT_INFO:
1242 case NBD_OPT_GO:
1243 ret = nbd_negotiate_handle_info(client, errp);
1244 if (ret == 1) {
1245 assert(option == NBD_OPT_GO);
1246 return 0;
1247 }
1248 break;
1249
1250 case NBD_OPT_STARTTLS:
1251 if (length) {
1252 ret = nbd_reject_length(client, false, errp);
1253 } else if (client->tlscreds) {
1254 ret = nbd_negotiate_send_rep_err(client,
1255 NBD_REP_ERR_INVALID, errp,
1256 "TLS already enabled");
1257 } else {
1258 ret = nbd_negotiate_send_rep_err(client,
1259 NBD_REP_ERR_POLICY, errp,
1260 "TLS not configured");
1261 }
1262 break;
1263
1264 case NBD_OPT_STRUCTURED_REPLY:
1265 if (length) {
1266 ret = nbd_reject_length(client, false, errp);
1267 } else if (client->mode >= NBD_MODE_STRUCTURED) {
1268 ret = nbd_negotiate_send_rep_err(
1269 client, NBD_REP_ERR_INVALID, errp,
1270 "structured reply already negotiated");
1271 } else {
1272 ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
1273 client->mode = NBD_MODE_STRUCTURED;
1274 }
1275 break;
1276
1277 case NBD_OPT_LIST_META_CONTEXT:
1278 case NBD_OPT_SET_META_CONTEXT:
1279 ret = nbd_negotiate_meta_queries(client, &client->export_meta,
1280 errp);
1281 break;
1282
1283 default:
1284 ret = nbd_opt_drop(client, NBD_REP_ERR_UNSUP, errp,
1285 "Unsupported option %" PRIu32 " (%s)",
1286 option, nbd_opt_lookup(option));
1287 break;
1288 }
1289 } else {
1290 /*
1291 * If broken new-style we should drop the connection
1292 * for anything except NBD_OPT_EXPORT_NAME
1293 */
1294 switch (option) {
1295 case NBD_OPT_EXPORT_NAME:
1296 return nbd_negotiate_handle_export_name(client, no_zeroes,
1297 errp);
1298
1299 default:
1300 error_setg(errp, "Unsupported option %" PRIu32 " (%s)",
1301 option, nbd_opt_lookup(option));
1302 return -EINVAL;
1303 }
1304 }
1305 if (ret < 0) {
1306 return ret;
1307 }
1308 }
1309 }
1310
1311 /* nbd_negotiate
1312 * Return:
1313 * -errno on error, errp is set
1314 * 0 on successful negotiation, errp is not set
1315 * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
1316 * errp is not set
1317 */
1318 static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp)
1319 {
1320 ERRP_GUARD();
1321 char buf[NBD_OLDSTYLE_NEGOTIATE_SIZE] = "";
1322 int ret;
1323
1324 /* Old style negotiation header, no room for options
1325 [ 0 .. 7] passwd ("NBDMAGIC")
1326 [ 8 .. 15] magic (NBD_CLIENT_MAGIC)
1327 [16 .. 23] size
1328 [24 .. 27] export flags (zero-extended)
1329 [28 .. 151] reserved (0)
1330
1331 New style negotiation header, client can send options
1332 [ 0 .. 7] passwd ("NBDMAGIC")
1333 [ 8 .. 15] magic (NBD_OPTS_MAGIC)
1334 [16 .. 17] server flags (0)
1335 ....options sent, ending in NBD_OPT_EXPORT_NAME or NBD_OPT_GO....
1336 */
1337
1338 qio_channel_set_blocking(client->ioc, false, NULL);
1339 qio_channel_set_follow_coroutine_ctx(client->ioc, true);
1340
1341 trace_nbd_negotiate_begin();
1342 memcpy(buf, "NBDMAGIC", 8);
1343
1344 stq_be_p(buf + 8, NBD_OPTS_MAGIC);
1345 stw_be_p(buf + 16, NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES);
1346
1347 if (nbd_write(client->ioc, buf, 18, errp) < 0) {
1348 error_prepend(errp, "write failed: ");
1349 return -EINVAL;
1350 }
1351 ret = nbd_negotiate_options(client, errp);
1352 if (ret != 0) {
1353 if (ret < 0) {
1354 error_prepend(errp, "option negotiation failed: ");
1355 }
1356 return ret;
1357 }
1358
1359 assert(!client->optlen);
1360 trace_nbd_negotiate_success();
1361
1362 return 0;
1363 }
1364
1365 /* nbd_read_eof
1366 * Tries to read @size bytes from @ioc. This is a local implementation of
1367 * qio_channel_readv_all_eof. We have it here because we need it to be
1368 * interruptible and to know when the coroutine is yielding.
1369 * Returns 1 on success
1370 * 0 on eof, when no data was read (errp is not set)
1371 * negative errno on failure (errp is set)
1372 */
1373 static inline int coroutine_fn
1374 nbd_read_eof(NBDClient *client, void *buffer, size_t size, Error **errp)
1375 {
1376 bool partial = false;
1377
1378 assert(size);
1379 while (size > 0) {
1380 struct iovec iov = { .iov_base = buffer, .iov_len = size };
1381 ssize_t len;
1382
1383 len = qio_channel_readv(client->ioc, &iov, 1, errp);
1384 if (len == QIO_CHANNEL_ERR_BLOCK) {
1385 client->read_yielding = true;
1386 qio_channel_yield(client->ioc, G_IO_IN);
1387 client->read_yielding = false;
1388 if (client->quiescing) {
1389 return -EAGAIN;
1390 }
1391 continue;
1392 } else if (len < 0) {
1393 return -EIO;
1394 } else if (len == 0) {
1395 if (partial) {
1396 error_setg(errp,
1397 "Unexpected end-of-file before all bytes were read");
1398 return -EIO;
1399 } else {
1400 return 0;
1401 }
1402 }
1403
1404 partial = true;
1405 size -= len;
1406 buffer = (uint8_t *) buffer + len;
1407 }
1408 return 1;
1409 }
1410
1411 static int coroutine_fn nbd_receive_request(NBDClient *client, NBDRequest *request,
1412 Error **errp)
1413 {
1414 uint8_t buf[NBD_REQUEST_SIZE];
1415 uint32_t magic;
1416 int ret;
1417
1418 ret = nbd_read_eof(client, buf, sizeof(buf), errp);
1419 if (ret < 0) {
1420 return ret;
1421 }
1422 if (ret == 0) {
1423 return -EIO;
1424 }
1425
1426 /* Request
1427 [ 0 .. 3] magic (NBD_REQUEST_MAGIC)
1428 [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...)
1429 [ 6 .. 7] type (NBD_CMD_READ, ...)
1430 [ 8 .. 15] cookie
1431 [16 .. 23] from
1432 [24 .. 27] len
1433 */
1434
1435 magic = ldl_be_p(buf);
1436 request->flags = lduw_be_p(buf + 4);
1437 request->type = lduw_be_p(buf + 6);
1438 request->cookie = ldq_be_p(buf + 8);
1439 request->from = ldq_be_p(buf + 16);
1440 request->len = (uint32_t)ldl_be_p(buf + 24); /* widen 32 to 64 bits */
1441
1442 trace_nbd_receive_request(magic, request->flags, request->type,
1443 request->from, request->len);
1444
1445 if (magic != NBD_REQUEST_MAGIC) {
1446 error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", magic);
1447 return -EINVAL;
1448 }
1449 return 0;
1450 }
1451
1452 #define MAX_NBD_REQUESTS 16
1453
1454 void nbd_client_get(NBDClient *client)
1455 {
1456 client->refcount++;
1457 }
1458
1459 void nbd_client_put(NBDClient *client)
1460 {
1461 if (--client->refcount == 0) {
1462 /* The last reference should be dropped by client->close,
1463 * which is called by client_close.
1464 */
1465 assert(client->closing);
1466
1467 object_unref(OBJECT(client->sioc));
1468 object_unref(OBJECT(client->ioc));
1469 if (client->tlscreds) {
1470 object_unref(OBJECT(client->tlscreds));
1471 }
1472 g_free(client->tlsauthz);
1473 if (client->exp) {
1474 QTAILQ_REMOVE(&client->exp->clients, client, next);
1475 blk_exp_unref(&client->exp->common);
1476 }
1477 g_free(client->export_meta.bitmaps);
1478 g_free(client);
1479 }
1480 }
1481
1482 static void client_close(NBDClient *client, bool negotiated)
1483 {
1484 if (client->closing) {
1485 return;
1486 }
1487
1488 client->closing = true;
1489
1490 /* Force requests to finish. They will drop their own references,
1491 * then we'll close the socket and free the NBDClient.
1492 */
1493 qio_channel_shutdown(client->ioc, QIO_CHANNEL_SHUTDOWN_BOTH,
1494 NULL);
1495
1496 /* Also tell the client, so that they release their reference. */
1497 if (client->close_fn) {
1498 client->close_fn(client, negotiated);
1499 }
1500 }
1501
1502 static NBDRequestData *nbd_request_get(NBDClient *client)
1503 {
1504 NBDRequestData *req;
1505
1506 assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
1507 client->nb_requests++;
1508
1509 req = g_new0(NBDRequestData, 1);
1510 nbd_client_get(client);
1511 req->client = client;
1512 return req;
1513 }
1514
1515 static void nbd_request_put(NBDRequestData *req)
1516 {
1517 NBDClient *client = req->client;
1518
1519 if (req->data) {
1520 qemu_vfree(req->data);
1521 }
1522 g_free(req);
1523
1524 client->nb_requests--;
1525
1526 if (client->quiescing && client->nb_requests == 0) {
1527 aio_wait_kick();
1528 }
1529
1530 nbd_client_receive_next_request(client);
1531
1532 nbd_client_put(client);
1533 }
1534
1535 static void blk_aio_attached(AioContext *ctx, void *opaque)
1536 {
1537 NBDExport *exp = opaque;
1538 NBDClient *client;
1539
1540 trace_nbd_blk_aio_attached(exp->name, ctx);
1541
1542 exp->common.ctx = ctx;
1543
1544 QTAILQ_FOREACH(client, &exp->clients, next) {
1545 assert(client->nb_requests == 0);
1546 assert(client->recv_coroutine == NULL);
1547 assert(client->send_coroutine == NULL);
1548 }
1549 }
1550
1551 static void blk_aio_detach(void *opaque)
1552 {
1553 NBDExport *exp = opaque;
1554
1555 trace_nbd_blk_aio_detach(exp->name, exp->common.ctx);
1556
1557 exp->common.ctx = NULL;
1558 }
1559
1560 static void nbd_drained_begin(void *opaque)
1561 {
1562 NBDExport *exp = opaque;
1563 NBDClient *client;
1564
1565 QTAILQ_FOREACH(client, &exp->clients, next) {
1566 client->quiescing = true;
1567 }
1568 }
1569
1570 static void nbd_drained_end(void *opaque)
1571 {
1572 NBDExport *exp = opaque;
1573 NBDClient *client;
1574
1575 QTAILQ_FOREACH(client, &exp->clients, next) {
1576 client->quiescing = false;
1577 nbd_client_receive_next_request(client);
1578 }
1579 }
1580
1581 static bool nbd_drained_poll(void *opaque)
1582 {
1583 NBDExport *exp = opaque;
1584 NBDClient *client;
1585
1586 QTAILQ_FOREACH(client, &exp->clients, next) {
1587 if (client->nb_requests != 0) {
1588 /*
1589 * If there's a coroutine waiting for a request on nbd_read_eof()
1590 * enter it here so we don't depend on the client to wake it up.
1591 */
1592 if (client->recv_coroutine != NULL && client->read_yielding) {
1593 qio_channel_wake_read(client->ioc);
1594 }
1595
1596 return true;
1597 }
1598 }
1599
1600 return false;
1601 }
1602
1603 static void nbd_eject_notifier(Notifier *n, void *data)
1604 {
1605 NBDExport *exp = container_of(n, NBDExport, eject_notifier);
1606
1607 blk_exp_request_shutdown(&exp->common);
1608 }
1609
1610 void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk)
1611 {
1612 NBDExport *nbd_exp = container_of(exp, NBDExport, common);
1613 assert(exp->drv == &blk_exp_nbd);
1614 assert(nbd_exp->eject_notifier_blk == NULL);
1615
1616 blk_ref(blk);
1617 nbd_exp->eject_notifier_blk = blk;
1618 nbd_exp->eject_notifier.notify = nbd_eject_notifier;
1619 blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier);
1620 }
1621
1622 static const BlockDevOps nbd_block_ops = {
1623 .drained_begin = nbd_drained_begin,
1624 .drained_end = nbd_drained_end,
1625 .drained_poll = nbd_drained_poll,
1626 };
1627
1628 static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args,
1629 Error **errp)
1630 {
1631 NBDExport *exp = container_of(blk_exp, NBDExport, common);
1632 BlockExportOptionsNbd *arg = &exp_args->u.nbd;
1633 const char *name = arg->name ?: exp_args->node_name;
1634 BlockBackend *blk = blk_exp->blk;
1635 int64_t size;
1636 uint64_t perm, shared_perm;
1637 bool readonly = !exp_args->writable;
1638 BlockDirtyBitmapOrStrList *bitmaps;
1639 size_t i;
1640 int ret;
1641
1642 assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD);
1643
1644 if (!nbd_server_is_running()) {
1645 error_setg(errp, "NBD server not running");
1646 return -EINVAL;
1647 }
1648
1649 if (strlen(name) > NBD_MAX_STRING_SIZE) {
1650 error_setg(errp, "export name '%s' too long", name);
1651 return -EINVAL;
1652 }
1653
1654 if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) {
1655 error_setg(errp, "description '%s' too long", arg->description);
1656 return -EINVAL;
1657 }
1658
1659 if (nbd_export_find(name)) {
1660 error_setg(errp, "NBD server already has export named '%s'", name);
1661 return -EEXIST;
1662 }
1663
1664 size = blk_getlength(blk);
1665 if (size < 0) {
1666 error_setg_errno(errp, -size,
1667 "Failed to determine the NBD export's length");
1668 return size;
1669 }
1670
1671 /* Don't allow resize while the NBD server is running, otherwise we don't
1672 * care what happens with the node. */
1673 blk_get_perm(blk, &perm, &shared_perm);
1674 ret = blk_set_perm(blk, perm, shared_perm & ~BLK_PERM_RESIZE, errp);
1675 if (ret < 0) {
1676 return ret;
1677 }
1678
1679 QTAILQ_INIT(&exp->clients);
1680 exp->name = g_strdup(name);
1681 exp->description = g_strdup(arg->description);
1682 exp->nbdflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_FLUSH |
1683 NBD_FLAG_SEND_FUA | NBD_FLAG_SEND_CACHE);
1684
1685 if (nbd_server_max_connections() != 1) {
1686 exp->nbdflags |= NBD_FLAG_CAN_MULTI_CONN;
1687 }
1688 if (readonly) {
1689 exp->nbdflags |= NBD_FLAG_READ_ONLY;
1690 } else {
1691 exp->nbdflags |= (NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_WRITE_ZEROES |
1692 NBD_FLAG_SEND_FAST_ZERO);
1693 }
1694 exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE);
1695
1696 for (bitmaps = arg->bitmaps; bitmaps; bitmaps = bitmaps->next) {
1697 exp->nr_export_bitmaps++;
1698 }
1699 exp->export_bitmaps = g_new0(BdrvDirtyBitmap *, exp->nr_export_bitmaps);
1700 for (i = 0, bitmaps = arg->bitmaps; bitmaps;
1701 i++, bitmaps = bitmaps->next)
1702 {
1703 const char *bitmap;
1704 BlockDriverState *bs = blk_bs(blk);
1705 BdrvDirtyBitmap *bm = NULL;
1706
1707 switch (bitmaps->value->type) {
1708 case QTYPE_QSTRING:
1709 bitmap = bitmaps->value->u.local;
1710 while (bs) {
1711 bm = bdrv_find_dirty_bitmap(bs, bitmap);
1712 if (bm != NULL) {
1713 break;
1714 }
1715
1716 bs = bdrv_filter_or_cow_bs(bs);
1717 }
1718
1719 if (bm == NULL) {
1720 ret = -ENOENT;
1721 error_setg(errp, "Bitmap '%s' is not found",
1722 bitmaps->value->u.local);
1723 goto fail;
1724 }
1725
1726 if (readonly && bdrv_is_writable(bs) &&
1727 bdrv_dirty_bitmap_enabled(bm)) {
1728 ret = -EINVAL;
1729 error_setg(errp, "Enabled bitmap '%s' incompatible with "
1730 "readonly export", bitmap);
1731 goto fail;
1732 }
1733 break;
1734 case QTYPE_QDICT:
1735 bitmap = bitmaps->value->u.external.name;
1736 bm = block_dirty_bitmap_lookup(bitmaps->value->u.external.node,
1737 bitmap, NULL, errp);
1738 if (!bm) {
1739 ret = -ENOENT;
1740 goto fail;
1741 }
1742 break;
1743 default:
1744 abort();
1745 }
1746
1747 assert(bm);
1748
1749 if (bdrv_dirty_bitmap_check(bm, BDRV_BITMAP_ALLOW_RO, errp)) {
1750 ret = -EINVAL;
1751 goto fail;
1752 }
1753
1754 exp->export_bitmaps[i] = bm;
1755 assert(strlen(bitmap) <= BDRV_BITMAP_MAX_NAME_SIZE);
1756 }
1757
1758 /* Mark bitmaps busy in a separate loop, to simplify roll-back concerns. */
1759 for (i = 0; i < exp->nr_export_bitmaps; i++) {
1760 bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], true);
1761 }
1762
1763 exp->allocation_depth = arg->allocation_depth;
1764
1765 /*
1766 * We need to inhibit request queuing in the block layer to ensure we can
1767 * be properly quiesced when entering a drained section, as our coroutines
1768 * servicing pending requests might enter blk_pread().
1769 */
1770 blk_set_disable_request_queuing(blk, true);
1771
1772 blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp);
1773
1774 blk_set_dev_ops(blk, &nbd_block_ops, exp);
1775
1776 QTAILQ_INSERT_TAIL(&exports, exp, next);
1777
1778 return 0;
1779
1780 fail:
1781 g_free(exp->export_bitmaps);
1782 g_free(exp->name);
1783 g_free(exp->description);
1784 return ret;
1785 }
1786
1787 NBDExport *nbd_export_find(const char *name)
1788 {
1789 NBDExport *exp;
1790 QTAILQ_FOREACH(exp, &exports, next) {
1791 if (strcmp(name, exp->name) == 0) {
1792 return exp;
1793 }
1794 }
1795
1796 return NULL;
1797 }
1798
1799 AioContext *
1800 nbd_export_aio_context(NBDExport *exp)
1801 {
1802 return exp->common.ctx;
1803 }
1804
1805 static void nbd_export_request_shutdown(BlockExport *blk_exp)
1806 {
1807 NBDExport *exp = container_of(blk_exp, NBDExport, common);
1808 NBDClient *client, *next;
1809
1810 blk_exp_ref(&exp->common);
1811 /*
1812 * TODO: Should we expand QMP NbdServerRemoveNode enum to allow a
1813 * close mode that stops advertising the export to new clients but
1814 * still permits existing clients to run to completion? Because of
1815 * that possibility, nbd_export_close() can be called more than
1816 * once on an export.
1817 */
1818 QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) {
1819 client_close(client, true);
1820 }
1821 if (exp->name) {
1822 g_free(exp->name);
1823 exp->name = NULL;
1824 QTAILQ_REMOVE(&exports, exp, next);
1825 }
1826 blk_exp_unref(&exp->common);
1827 }
1828
1829 static void nbd_export_delete(BlockExport *blk_exp)
1830 {
1831 size_t i;
1832 NBDExport *exp = container_of(blk_exp, NBDExport, common);
1833
1834 assert(exp->name == NULL);
1835 assert(QTAILQ_EMPTY(&exp->clients));
1836
1837 g_free(exp->description);
1838 exp->description = NULL;
1839
1840 if (exp->eject_notifier_blk) {
1841 notifier_remove(&exp->eject_notifier);
1842 blk_unref(exp->eject_notifier_blk);
1843 }
1844 blk_remove_aio_context_notifier(exp->common.blk, blk_aio_attached,
1845 blk_aio_detach, exp);
1846 blk_set_disable_request_queuing(exp->common.blk, false);
1847
1848 for (i = 0; i < exp->nr_export_bitmaps; i++) {
1849 bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], false);
1850 }
1851 }
1852
1853 const BlockExportDriver blk_exp_nbd = {
1854 .type = BLOCK_EXPORT_TYPE_NBD,
1855 .instance_size = sizeof(NBDExport),
1856 .create = nbd_export_create,
1857 .delete = nbd_export_delete,
1858 .request_shutdown = nbd_export_request_shutdown,
1859 };
1860
1861 static int coroutine_fn nbd_co_send_iov(NBDClient *client, struct iovec *iov,
1862 unsigned niov, Error **errp)
1863 {
1864 int ret;
1865
1866 g_assert(qemu_in_coroutine());
1867 qemu_co_mutex_lock(&client->send_lock);
1868 client->send_coroutine = qemu_coroutine_self();
1869
1870 ret = qio_channel_writev_all(client->ioc, iov, niov, errp) < 0 ? -EIO : 0;
1871
1872 client->send_coroutine = NULL;
1873 qemu_co_mutex_unlock(&client->send_lock);
1874
1875 return ret;
1876 }
1877
1878 static inline void set_be_simple_reply(NBDSimpleReply *reply, uint64_t error,
1879 uint64_t cookie)
1880 {
1881 stl_be_p(&reply->magic, NBD_SIMPLE_REPLY_MAGIC);
1882 stl_be_p(&reply->error, error);
1883 stq_be_p(&reply->cookie, cookie);
1884 }
1885
1886 static int coroutine_fn nbd_co_send_simple_reply(NBDClient *client,
1887 NBDRequest *request,
1888 uint32_t error,
1889 void *data,
1890 uint64_t len,
1891 Error **errp)
1892 {
1893 NBDSimpleReply reply;
1894 int nbd_err = system_errno_to_nbd_errno(error);
1895 struct iovec iov[] = {
1896 {.iov_base = &reply, .iov_len = sizeof(reply)},
1897 {.iov_base = data, .iov_len = len}
1898 };
1899
1900 assert(!len || !nbd_err);
1901 assert(len <= NBD_MAX_BUFFER_SIZE);
1902 assert(client->mode < NBD_MODE_STRUCTURED ||
1903 (client->mode == NBD_MODE_STRUCTURED &&
1904 request->type != NBD_CMD_READ));
1905 trace_nbd_co_send_simple_reply(request->cookie, nbd_err,
1906 nbd_err_lookup(nbd_err), len);
1907 set_be_simple_reply(&reply, nbd_err, request->cookie);
1908
1909 return nbd_co_send_iov(client, iov, 2, errp);
1910 }
1911
1912 /*
1913 * Prepare the header of a reply chunk for network transmission.
1914 *
1915 * On input, @iov is partially initialized: iov[0].iov_base must point
1916 * to an uninitialized NBDReply, while the remaining @niov elements
1917 * (if any) must be ready for transmission. This function then
1918 * populates iov[0] for transmission.
1919 */
1920 static inline void set_be_chunk(NBDClient *client, struct iovec *iov,
1921 size_t niov, uint16_t flags, uint16_t type,
1922 NBDRequest *request)
1923 {
1924 /* TODO - handle structured vs. extended replies */
1925 NBDStructuredReplyChunk *chunk = iov->iov_base;
1926 size_t i, length = 0;
1927
1928 for (i = 1; i < niov; i++) {
1929 length += iov[i].iov_len;
1930 }
1931 assert(length <= NBD_MAX_BUFFER_SIZE + sizeof(NBDStructuredReadData));
1932
1933 iov[0].iov_len = sizeof(*chunk);
1934 stl_be_p(&chunk->magic, NBD_STRUCTURED_REPLY_MAGIC);
1935 stw_be_p(&chunk->flags, flags);
1936 stw_be_p(&chunk->type, type);
1937 stq_be_p(&chunk->cookie, request->cookie);
1938 stl_be_p(&chunk->length, length);
1939 }
1940
1941 static int coroutine_fn nbd_co_send_chunk_done(NBDClient *client,
1942 NBDRequest *request,
1943 Error **errp)
1944 {
1945 NBDReply hdr;
1946 struct iovec iov[] = {
1947 {.iov_base = &hdr},
1948 };
1949
1950 trace_nbd_co_send_chunk_done(request->cookie);
1951 set_be_chunk(client, iov, 1, NBD_REPLY_FLAG_DONE,
1952 NBD_REPLY_TYPE_NONE, request);
1953 return nbd_co_send_iov(client, iov, 1, errp);
1954 }
1955
1956 static int coroutine_fn nbd_co_send_chunk_read(NBDClient *client,
1957 NBDRequest *request,
1958 uint64_t offset,
1959 void *data,
1960 uint64_t size,
1961 bool final,
1962 Error **errp)
1963 {
1964 NBDReply hdr;
1965 NBDStructuredReadData chunk;
1966 struct iovec iov[] = {
1967 {.iov_base = &hdr},
1968 {.iov_base = &chunk, .iov_len = sizeof(chunk)},
1969 {.iov_base = data, .iov_len = size}
1970 };
1971
1972 assert(size && size <= NBD_MAX_BUFFER_SIZE);
1973 trace_nbd_co_send_chunk_read(request->cookie, offset, data, size);
1974 set_be_chunk(client, iov, 3, final ? NBD_REPLY_FLAG_DONE : 0,
1975 NBD_REPLY_TYPE_OFFSET_DATA, request);
1976 stq_be_p(&chunk.offset, offset);
1977
1978 return nbd_co_send_iov(client, iov, 3, errp);
1979 }
1980
1981 static int coroutine_fn nbd_co_send_chunk_error(NBDClient *client,
1982 NBDRequest *request,
1983 uint32_t error,
1984 const char *msg,
1985 Error **errp)
1986 {
1987 NBDReply hdr;
1988 NBDStructuredError chunk;
1989 int nbd_err = system_errno_to_nbd_errno(error);
1990 struct iovec iov[] = {
1991 {.iov_base = &hdr},
1992 {.iov_base = &chunk, .iov_len = sizeof(chunk)},
1993 {.iov_base = (char *)msg, .iov_len = msg ? strlen(msg) : 0},
1994 };
1995
1996 assert(nbd_err);
1997 trace_nbd_co_send_chunk_error(request->cookie, nbd_err,
1998 nbd_err_lookup(nbd_err), msg ? msg : "");
1999 set_be_chunk(client, iov, 3, NBD_REPLY_FLAG_DONE,
2000 NBD_REPLY_TYPE_ERROR, request);
2001 stl_be_p(&chunk.error, nbd_err);
2002 stw_be_p(&chunk.message_length, iov[2].iov_len);
2003
2004 return nbd_co_send_iov(client, iov, 3, errp);
2005 }
2006
2007 /* Do a sparse read and send the structured reply to the client.
2008 * Returns -errno if sending fails. blk_co_block_status_above() failure is
2009 * reported to the client, at which point this function succeeds.
2010 */
2011 static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client,
2012 NBDRequest *request,
2013 uint64_t offset,
2014 uint8_t *data,
2015 uint64_t size,
2016 Error **errp)
2017 {
2018 int ret = 0;
2019 NBDExport *exp = client->exp;
2020 size_t progress = 0;
2021
2022 assert(size <= NBD_MAX_BUFFER_SIZE);
2023 while (progress < size) {
2024 int64_t pnum;
2025 int status = blk_co_block_status_above(exp->common.blk, NULL,
2026 offset + progress,
2027 size - progress, &pnum, NULL,
2028 NULL);
2029 bool final;
2030
2031 if (status < 0) {
2032 char *msg = g_strdup_printf("unable to check for holes: %s",
2033 strerror(-status));
2034
2035 ret = nbd_co_send_chunk_error(client, request, -status, msg, errp);
2036 g_free(msg);
2037 return ret;
2038 }
2039 assert(pnum && pnum <= size - progress);
2040 final = progress + pnum == size;
2041 if (status & BDRV_BLOCK_ZERO) {
2042 NBDReply hdr;
2043 NBDStructuredReadHole chunk;
2044 struct iovec iov[] = {
2045 {.iov_base = &hdr},
2046 {.iov_base = &chunk, .iov_len = sizeof(chunk)},
2047 };
2048
2049 trace_nbd_co_send_chunk_read_hole(request->cookie,
2050 offset + progress, pnum);
2051 set_be_chunk(client, iov, 2,
2052 final ? NBD_REPLY_FLAG_DONE : 0,
2053 NBD_REPLY_TYPE_OFFSET_HOLE, request);
2054 stq_be_p(&chunk.offset, offset + progress);
2055 stl_be_p(&chunk.length, pnum);
2056 ret = nbd_co_send_iov(client, iov, 2, errp);
2057 } else {
2058 ret = blk_co_pread(exp->common.blk, offset + progress, pnum,
2059 data + progress, 0);
2060 if (ret < 0) {
2061 error_setg_errno(errp, -ret, "reading from file failed");
2062 break;
2063 }
2064 ret = nbd_co_send_chunk_read(client, request, offset + progress,
2065 data + progress, pnum, final, errp);
2066 }
2067
2068 if (ret < 0) {
2069 break;
2070 }
2071 progress += pnum;
2072 }
2073 return ret;
2074 }
2075
2076 typedef struct NBDExtentArray {
2077 NBDExtent32 *extents;
2078 unsigned int nb_alloc;
2079 unsigned int count;
2080 uint64_t total_length;
2081 bool can_add;
2082 bool converted_to_be;
2083 } NBDExtentArray;
2084
2085 static NBDExtentArray *nbd_extent_array_new(unsigned int nb_alloc)
2086 {
2087 NBDExtentArray *ea = g_new0(NBDExtentArray, 1);
2088
2089 ea->nb_alloc = nb_alloc;
2090 ea->extents = g_new(NBDExtent32, nb_alloc);
2091 ea->can_add = true;
2092
2093 return ea;
2094 }
2095
2096 static void nbd_extent_array_free(NBDExtentArray *ea)
2097 {
2098 g_free(ea->extents);
2099 g_free(ea);
2100 }
2101 G_DEFINE_AUTOPTR_CLEANUP_FUNC(NBDExtentArray, nbd_extent_array_free)
2102
2103 /* Further modifications of the array after conversion are abandoned */
2104 static void nbd_extent_array_convert_to_be(NBDExtentArray *ea)
2105 {
2106 int i;
2107
2108 assert(!ea->converted_to_be);
2109 ea->can_add = false;
2110 ea->converted_to_be = true;
2111
2112 for (i = 0; i < ea->count; i++) {
2113 ea->extents[i].flags = cpu_to_be32(ea->extents[i].flags);
2114 ea->extents[i].length = cpu_to_be32(ea->extents[i].length);
2115 }
2116 }
2117
2118 /*
2119 * Add extent to NBDExtentArray. If extent can't be added (no available space),
2120 * return -1.
2121 * For safety, when returning -1 for the first time, .can_add is set to false,
2122 * and further calls to nbd_extent_array_add() will crash.
2123 * (this avoids the situation where a caller ignores failure to add one extent,
2124 * where adding another extent that would squash into the last array entry
2125 * would result in an incorrect range reported to the client)
2126 */
2127 static int nbd_extent_array_add(NBDExtentArray *ea,
2128 uint32_t length, uint32_t flags)
2129 {
2130 assert(ea->can_add);
2131
2132 if (!length) {
2133 return 0;
2134 }
2135
2136 /* Extend previous extent if flags are the same */
2137 if (ea->count > 0 && flags == ea->extents[ea->count - 1].flags) {
2138 uint64_t sum = (uint64_t)length + ea->extents[ea->count - 1].length;
2139
2140 if (sum <= UINT32_MAX) {
2141 ea->extents[ea->count - 1].length = sum;
2142 ea->total_length += length;
2143 return 0;
2144 }
2145 }
2146
2147 if (ea->count >= ea->nb_alloc) {
2148 ea->can_add = false;
2149 return -1;
2150 }
2151
2152 ea->total_length += length;
2153 ea->extents[ea->count] = (NBDExtent32) {.length = length, .flags = flags};
2154 ea->count++;
2155
2156 return 0;
2157 }
2158
2159 static int coroutine_fn blockstatus_to_extents(BlockBackend *blk,
2160 uint64_t offset, uint64_t bytes,
2161 NBDExtentArray *ea)
2162 {
2163 while (bytes) {
2164 uint32_t flags;
2165 int64_t num;
2166 int ret = blk_co_block_status_above(blk, NULL, offset, bytes, &num,
2167 NULL, NULL);
2168
2169 if (ret < 0) {
2170 return ret;
2171 }
2172
2173 flags = (ret & BDRV_BLOCK_DATA ? 0 : NBD_STATE_HOLE) |
2174 (ret & BDRV_BLOCK_ZERO ? NBD_STATE_ZERO : 0);
2175
2176 if (nbd_extent_array_add(ea, num, flags) < 0) {
2177 return 0;
2178 }
2179
2180 offset += num;
2181 bytes -= num;
2182 }
2183
2184 return 0;
2185 }
2186
2187 static int coroutine_fn blockalloc_to_extents(BlockBackend *blk,
2188 uint64_t offset, uint64_t bytes,
2189 NBDExtentArray *ea)
2190 {
2191 while (bytes) {
2192 int64_t num;
2193 int ret = blk_co_is_allocated_above(blk, NULL, false, offset, bytes,
2194 &num);
2195
2196 if (ret < 0) {
2197 return ret;
2198 }
2199
2200 if (nbd_extent_array_add(ea, num, ret) < 0) {
2201 return 0;
2202 }
2203
2204 offset += num;
2205 bytes -= num;
2206 }
2207
2208 return 0;
2209 }
2210
2211 /*
2212 * nbd_co_send_extents
2213 *
2214 * @ea is converted to BE by the function
2215 * @last controls whether NBD_REPLY_FLAG_DONE is sent.
2216 */
2217 static int coroutine_fn
2218 nbd_co_send_extents(NBDClient *client, NBDRequest *request, NBDExtentArray *ea,
2219 bool last, uint32_t context_id, Error **errp)
2220 {
2221 NBDReply hdr;
2222 NBDStructuredMeta chunk;
2223 struct iovec iov[] = {
2224 {.iov_base = &hdr},
2225 {.iov_base = &chunk, .iov_len = sizeof(chunk)},
2226 {.iov_base = ea->extents, .iov_len = ea->count * sizeof(ea->extents[0])}
2227 };
2228
2229 nbd_extent_array_convert_to_be(ea);
2230
2231 trace_nbd_co_send_extents(request->cookie, ea->count, context_id,
2232 ea->total_length, last);
2233 set_be_chunk(client, iov, 3, last ? NBD_REPLY_FLAG_DONE : 0,
2234 NBD_REPLY_TYPE_BLOCK_STATUS, request);
2235 stl_be_p(&chunk.context_id, context_id);
2236
2237 return nbd_co_send_iov(client, iov, 3, errp);
2238 }
2239
2240 /* Get block status from the exported device and send it to the client */
2241 static int
2242 coroutine_fn nbd_co_send_block_status(NBDClient *client, NBDRequest *request,
2243 BlockBackend *blk, uint64_t offset,
2244 uint32_t length, bool dont_fragment,
2245 bool last, uint32_t context_id,
2246 Error **errp)
2247 {
2248 int ret;
2249 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
2250 g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
2251
2252 if (context_id == NBD_META_ID_BASE_ALLOCATION) {
2253 ret = blockstatus_to_extents(blk, offset, length, ea);
2254 } else {
2255 ret = blockalloc_to_extents(blk, offset, length, ea);
2256 }
2257 if (ret < 0) {
2258 return nbd_co_send_chunk_error(client, request, -ret,
2259 "can't get block status", errp);
2260 }
2261
2262 return nbd_co_send_extents(client, request, ea, last, context_id, errp);
2263 }
2264
2265 /* Populate @ea from a dirty bitmap. */
2266 static void bitmap_to_extents(BdrvDirtyBitmap *bitmap,
2267 uint64_t offset, uint64_t length,
2268 NBDExtentArray *es)
2269 {
2270 int64_t start, dirty_start, dirty_count;
2271 int64_t end = offset + length;
2272 bool full = false;
2273
2274 bdrv_dirty_bitmap_lock(bitmap);
2275
2276 for (start = offset;
2277 bdrv_dirty_bitmap_next_dirty_area(bitmap, start, end, INT32_MAX,
2278 &dirty_start, &dirty_count);
2279 start = dirty_start + dirty_count)
2280 {
2281 if ((nbd_extent_array_add(es, dirty_start - start, 0) < 0) ||
2282 (nbd_extent_array_add(es, dirty_count, NBD_STATE_DIRTY) < 0))
2283 {
2284 full = true;
2285 break;
2286 }
2287 }
2288
2289 if (!full) {
2290 /* last non dirty extent, nothing to do if array is now full */
2291 (void) nbd_extent_array_add(es, end - start, 0);
2292 }
2293
2294 bdrv_dirty_bitmap_unlock(bitmap);
2295 }
2296
2297 static int coroutine_fn nbd_co_send_bitmap(NBDClient *client,
2298 NBDRequest *request,
2299 BdrvDirtyBitmap *bitmap,
2300 uint64_t offset,
2301 uint32_t length, bool dont_fragment,
2302 bool last, uint32_t context_id,
2303 Error **errp)
2304 {
2305 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
2306 g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
2307
2308 bitmap_to_extents(bitmap, offset, length, ea);
2309
2310 return nbd_co_send_extents(client, request, ea, last, context_id, errp);
2311 }
2312
2313 /* nbd_co_receive_request
2314 * Collect a client request. Return 0 if request looks valid, -EIO to drop
2315 * connection right away, -EAGAIN to indicate we were interrupted and the
2316 * channel should be quiesced, and any other negative value to report an error
2317 * to the client (although the caller may still need to disconnect after
2318 * reporting the error).
2319 */
2320 static int coroutine_fn nbd_co_receive_request(NBDRequestData *req,
2321 NBDRequest *request,
2322 Error **errp)
2323 {
2324 NBDClient *client = req->client;
2325 bool check_length = false;
2326 bool check_rofs = false;
2327 bool allocate_buffer = false;
2328 unsigned payload_len = 0;
2329 int valid_flags = NBD_CMD_FLAG_FUA;
2330 int ret;
2331
2332 g_assert(qemu_in_coroutine());
2333 assert(client->recv_coroutine == qemu_coroutine_self());
2334 ret = nbd_receive_request(client, request, errp);
2335 if (ret < 0) {
2336 return ret;
2337 }
2338
2339 trace_nbd_co_receive_request_decode_type(request->cookie, request->type,
2340 nbd_cmd_lookup(request->type));
2341 switch (request->type) {
2342 case NBD_CMD_DISC:
2343 /* Special case: we're going to disconnect without a reply,
2344 * whether or not flags, from, or len are bogus */
2345 req->complete = true;
2346 return -EIO;
2347
2348 case NBD_CMD_READ:
2349 if (client->mode >= NBD_MODE_STRUCTURED) {
2350 valid_flags |= NBD_CMD_FLAG_DF;
2351 }
2352 check_length = true;
2353 allocate_buffer = true;
2354 break;
2355
2356 case NBD_CMD_WRITE:
2357 payload_len = request->len;
2358 check_length = true;
2359 allocate_buffer = true;
2360 check_rofs = true;
2361 break;
2362
2363 case NBD_CMD_FLUSH:
2364 break;
2365
2366 case NBD_CMD_TRIM:
2367 check_rofs = true;
2368 break;
2369
2370 case NBD_CMD_CACHE:
2371 check_length = true;
2372 break;
2373
2374 case NBD_CMD_WRITE_ZEROES:
2375 valid_flags |= NBD_CMD_FLAG_NO_HOLE | NBD_CMD_FLAG_FAST_ZERO;
2376 check_rofs = true;
2377 break;
2378
2379 case NBD_CMD_BLOCK_STATUS:
2380 valid_flags |= NBD_CMD_FLAG_REQ_ONE;
2381 break;
2382
2383 default:
2384 /* Unrecognized, will fail later */
2385 ;
2386 }
2387
2388 /* Payload and buffer handling. */
2389 if (!payload_len) {
2390 req->complete = true;
2391 }
2392 if (check_length && request->len > NBD_MAX_BUFFER_SIZE) {
2393 /* READ, WRITE, CACHE */
2394 error_setg(errp, "len (%" PRIu64 ") is larger than max len (%u)",
2395 request->len, NBD_MAX_BUFFER_SIZE);
2396 return -EINVAL;
2397 }
2398 if (allocate_buffer) {
2399 /* READ, WRITE */
2400 req->data = blk_try_blockalign(client->exp->common.blk,
2401 request->len);
2402 if (req->data == NULL) {
2403 error_setg(errp, "No memory");
2404 return -ENOMEM;
2405 }
2406 }
2407 if (payload_len) {
2408 /* WRITE */
2409 assert(req->data);
2410 ret = nbd_read(client->ioc, req->data, payload_len,
2411 "CMD_WRITE data", errp);
2412 if (ret < 0) {
2413 return -EIO;
2414 }
2415 req->complete = true;
2416 trace_nbd_co_receive_request_payload_received(request->cookie,
2417 payload_len);
2418 }
2419
2420 /* Sanity checks. */
2421 if (client->exp->nbdflags & NBD_FLAG_READ_ONLY && check_rofs) {
2422 /* WRITE, TRIM, WRITE_ZEROES */
2423 error_setg(errp, "Export is read-only");
2424 return -EROFS;
2425 }
2426 if (request->from > client->exp->size ||
2427 request->len > client->exp->size - request->from) {
2428 error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu64
2429 ", Size: %" PRIu64, request->from, request->len,
2430 client->exp->size);
2431 return (request->type == NBD_CMD_WRITE ||
2432 request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL;
2433 }
2434 if (client->check_align && !QEMU_IS_ALIGNED(request->from | request->len,
2435 client->check_align)) {
2436 /*
2437 * The block layer gracefully handles unaligned requests, but
2438 * it's still worth tracing client non-compliance
2439 */
2440 trace_nbd_co_receive_align_compliance(nbd_cmd_lookup(request->type),
2441 request->from,
2442 request->len,
2443 client->check_align);
2444 }
2445 if (request->flags & ~valid_flags) {
2446 error_setg(errp, "unsupported flags for command %s (got 0x%x)",
2447 nbd_cmd_lookup(request->type), request->flags);
2448 return -EINVAL;
2449 }
2450
2451 return 0;
2452 }
2453
2454 /* Send simple reply without a payload, or a structured error
2455 * @error_msg is ignored if @ret >= 0
2456 * Returns 0 if connection is still live, -errno on failure to talk to client
2457 */
2458 static coroutine_fn int nbd_send_generic_reply(NBDClient *client,
2459 NBDRequest *request,
2460 int ret,
2461 const char *error_msg,
2462 Error **errp)
2463 {
2464 if (client->mode >= NBD_MODE_STRUCTURED && ret < 0) {
2465 return nbd_co_send_chunk_error(client, request, -ret, error_msg, errp);
2466 } else {
2467 return nbd_co_send_simple_reply(client, request, ret < 0 ? -ret : 0,
2468 NULL, 0, errp);
2469 }
2470 }
2471
2472 /* Handle NBD_CMD_READ request.
2473 * Return -errno if sending fails. Other errors are reported directly to the
2474 * client as an error reply. */
2475 static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request,
2476 uint8_t *data, Error **errp)
2477 {
2478 int ret;
2479 NBDExport *exp = client->exp;
2480
2481 assert(request->type == NBD_CMD_READ);
2482 assert(request->len <= NBD_MAX_BUFFER_SIZE);
2483
2484 /* XXX: NBD Protocol only documents use of FUA with WRITE */
2485 if (request->flags & NBD_CMD_FLAG_FUA) {
2486 ret = blk_co_flush(exp->common.blk);
2487 if (ret < 0) {
2488 return nbd_send_generic_reply(client, request, ret,
2489 "flush failed", errp);
2490 }
2491 }
2492
2493 if (client->mode >= NBD_MODE_STRUCTURED &&
2494 !(request->flags & NBD_CMD_FLAG_DF) && request->len)
2495 {
2496 return nbd_co_send_sparse_read(client, request, request->from,
2497 data, request->len, errp);
2498 }
2499
2500 ret = blk_co_pread(exp->common.blk, request->from, request->len, data, 0);
2501 if (ret < 0) {
2502 return nbd_send_generic_reply(client, request, ret,
2503 "reading from file failed", errp);
2504 }
2505
2506 if (client->mode >= NBD_MODE_STRUCTURED) {
2507 if (request->len) {
2508 return nbd_co_send_chunk_read(client, request, request->from, data,
2509 request->len, true, errp);
2510 } else {
2511 return nbd_co_send_chunk_done(client, request, errp);
2512 }
2513 } else {
2514 return nbd_co_send_simple_reply(client, request, 0,
2515 data, request->len, errp);
2516 }
2517 }
2518
2519 /*
2520 * nbd_do_cmd_cache
2521 *
2522 * Handle NBD_CMD_CACHE request.
2523 * Return -errno if sending fails. Other errors are reported directly to the
2524 * client as an error reply.
2525 */
2526 static coroutine_fn int nbd_do_cmd_cache(NBDClient *client, NBDRequest *request,
2527 Error **errp)
2528 {
2529 int ret;
2530 NBDExport *exp = client->exp;
2531
2532 assert(request->type == NBD_CMD_CACHE);
2533 assert(request->len <= NBD_MAX_BUFFER_SIZE);
2534
2535 ret = blk_co_preadv(exp->common.blk, request->from, request->len,
2536 NULL, BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH);
2537
2538 return nbd_send_generic_reply(client, request, ret,
2539 "caching data failed", errp);
2540 }
2541
2542 /* Handle NBD request.
2543 * Return -errno if sending fails. Other errors are reported directly to the
2544 * client as an error reply. */
2545 static coroutine_fn int nbd_handle_request(NBDClient *client,
2546 NBDRequest *request,
2547 uint8_t *data, Error **errp)
2548 {
2549 int ret;
2550 int flags;
2551 NBDExport *exp = client->exp;
2552 char *msg;
2553 size_t i;
2554
2555 switch (request->type) {
2556 case NBD_CMD_CACHE:
2557 return nbd_do_cmd_cache(client, request, errp);
2558
2559 case NBD_CMD_READ:
2560 return nbd_do_cmd_read(client, request, data, errp);
2561
2562 case NBD_CMD_WRITE:
2563 flags = 0;
2564 if (request->flags & NBD_CMD_FLAG_FUA) {
2565 flags |= BDRV_REQ_FUA;
2566 }
2567 assert(request->len <= NBD_MAX_BUFFER_SIZE);
2568 ret = blk_co_pwrite(exp->common.blk, request->from, request->len, data,
2569 flags);
2570 return nbd_send_generic_reply(client, request, ret,
2571 "writing to file failed", errp);
2572
2573 case NBD_CMD_WRITE_ZEROES:
2574 flags = 0;
2575 if (request->flags & NBD_CMD_FLAG_FUA) {
2576 flags |= BDRV_REQ_FUA;
2577 }
2578 if (!(request->flags & NBD_CMD_FLAG_NO_HOLE)) {
2579 flags |= BDRV_REQ_MAY_UNMAP;
2580 }
2581 if (request->flags & NBD_CMD_FLAG_FAST_ZERO) {
2582 flags |= BDRV_REQ_NO_FALLBACK;
2583 }
2584 ret = blk_co_pwrite_zeroes(exp->common.blk, request->from, request->len,
2585 flags);
2586 return nbd_send_generic_reply(client, request, ret,
2587 "writing to file failed", errp);
2588
2589 case NBD_CMD_DISC:
2590 /* unreachable, thanks to special case in nbd_co_receive_request() */
2591 abort();
2592
2593 case NBD_CMD_FLUSH:
2594 ret = blk_co_flush(exp->common.blk);
2595 return nbd_send_generic_reply(client, request, ret,
2596 "flush failed", errp);
2597
2598 case NBD_CMD_TRIM:
2599 ret = blk_co_pdiscard(exp->common.blk, request->from, request->len);
2600 if (ret >= 0 && request->flags & NBD_CMD_FLAG_FUA) {
2601 ret = blk_co_flush(exp->common.blk);
2602 }
2603 return nbd_send_generic_reply(client, request, ret,
2604 "discard failed", errp);
2605
2606 case NBD_CMD_BLOCK_STATUS:
2607 if (!request->len) {
2608 return nbd_send_generic_reply(client, request, -EINVAL,
2609 "need non-zero length", errp);
2610 }
2611 assert(request->len <= UINT32_MAX);
2612 if (client->export_meta.count) {
2613 bool dont_fragment = request->flags & NBD_CMD_FLAG_REQ_ONE;
2614 int contexts_remaining = client->export_meta.count;
2615
2616 if (client->export_meta.base_allocation) {
2617 ret = nbd_co_send_block_status(client, request,
2618 exp->common.blk,
2619 request->from,
2620 request->len, dont_fragment,
2621 !--contexts_remaining,
2622 NBD_META_ID_BASE_ALLOCATION,
2623 errp);
2624 if (ret < 0) {
2625 return ret;
2626 }
2627 }
2628
2629 if (client->export_meta.allocation_depth) {
2630 ret = nbd_co_send_block_status(client, request,
2631 exp->common.blk,
2632 request->from, request->len,
2633 dont_fragment,
2634 !--contexts_remaining,
2635 NBD_META_ID_ALLOCATION_DEPTH,
2636 errp);
2637 if (ret < 0) {
2638 return ret;
2639 }
2640 }
2641
2642 for (i = 0; i < client->exp->nr_export_bitmaps; i++) {
2643 if (!client->export_meta.bitmaps[i]) {
2644 continue;
2645 }
2646 ret = nbd_co_send_bitmap(client, request,
2647 client->exp->export_bitmaps[i],
2648 request->from, request->len,
2649 dont_fragment, !--contexts_remaining,
2650 NBD_META_ID_DIRTY_BITMAP + i, errp);
2651 if (ret < 0) {
2652 return ret;
2653 }
2654 }
2655
2656 assert(!contexts_remaining);
2657
2658 return 0;
2659 } else {
2660 return nbd_send_generic_reply(client, request, -EINVAL,
2661 "CMD_BLOCK_STATUS not negotiated",
2662 errp);
2663 }
2664
2665 default:
2666 msg = g_strdup_printf("invalid request type (%" PRIu32 ") received",
2667 request->type);
2668 ret = nbd_send_generic_reply(client, request, -EINVAL, msg,
2669 errp);
2670 g_free(msg);
2671 return ret;
2672 }
2673 }
2674
2675 /* Owns a reference to the NBDClient passed as opaque. */
2676 static coroutine_fn void nbd_trip(void *opaque)
2677 {
2678 NBDClient *client = opaque;
2679 NBDRequestData *req;
2680 NBDRequest request = { 0 }; /* GCC thinks it can be used uninitialized */
2681 int ret;
2682 Error *local_err = NULL;
2683
2684 trace_nbd_trip();
2685 if (client->closing) {
2686 nbd_client_put(client);
2687 return;
2688 }
2689
2690 if (client->quiescing) {
2691 /*
2692 * We're switching between AIO contexts. Don't attempt to receive a new
2693 * request and kick the main context which may be waiting for us.
2694 */
2695 nbd_client_put(client);
2696 client->recv_coroutine = NULL;
2697 aio_wait_kick();
2698 return;
2699 }
2700
2701 req = nbd_request_get(client);
2702 ret = nbd_co_receive_request(req, &request, &local_err);
2703 client->recv_coroutine = NULL;
2704
2705 if (client->closing) {
2706 /*
2707 * The client may be closed when we are blocked in
2708 * nbd_co_receive_request()
2709 */
2710 goto done;
2711 }
2712
2713 if (ret == -EAGAIN) {
2714 assert(client->quiescing);
2715 goto done;
2716 }
2717
2718 nbd_client_receive_next_request(client);
2719 if (ret == -EIO) {
2720 goto disconnect;
2721 }
2722
2723 qio_channel_set_cork(client->ioc, true);
2724
2725 if (ret < 0) {
2726 /* It wasn't -EIO, so, according to nbd_co_receive_request()
2727 * semantics, we should return the error to the client. */
2728 Error *export_err = local_err;
2729
2730 local_err = NULL;
2731 ret = nbd_send_generic_reply(client, &request, -EINVAL,
2732 error_get_pretty(export_err), &local_err);
2733 error_free(export_err);
2734 } else {
2735 ret = nbd_handle_request(client, &request, req->data, &local_err);
2736 }
2737 if (ret < 0) {
2738 error_prepend(&local_err, "Failed to send reply: ");
2739 goto disconnect;
2740 }
2741
2742 /* We must disconnect after NBD_CMD_WRITE if we did not
2743 * read the payload.
2744 */
2745 if (!req->complete) {
2746 error_setg(&local_err, "Request handling failed in intermediate state");
2747 goto disconnect;
2748 }
2749
2750 qio_channel_set_cork(client->ioc, false);
2751 done:
2752 nbd_request_put(req);
2753 nbd_client_put(client);
2754 return;
2755
2756 disconnect:
2757 if (local_err) {
2758 error_reportf_err(local_err, "Disconnect client, due to: ");
2759 }
2760 nbd_request_put(req);
2761 client_close(client, true);
2762 nbd_client_put(client);
2763 }
2764
2765 static void nbd_client_receive_next_request(NBDClient *client)
2766 {
2767 if (!client->recv_coroutine && client->nb_requests < MAX_NBD_REQUESTS &&
2768 !client->quiescing) {
2769 nbd_client_get(client);
2770 client->recv_coroutine = qemu_coroutine_create(nbd_trip, client);
2771 aio_co_schedule(client->exp->common.ctx, client->recv_coroutine);
2772 }
2773 }
2774
2775 static coroutine_fn void nbd_co_client_start(void *opaque)
2776 {
2777 NBDClient *client = opaque;
2778 Error *local_err = NULL;
2779
2780 qemu_co_mutex_init(&client->send_lock);
2781
2782 if (nbd_negotiate(client, &local_err)) {
2783 if (local_err) {
2784 error_report_err(local_err);
2785 }
2786 client_close(client, false);
2787 return;
2788 }
2789
2790 nbd_client_receive_next_request(client);
2791 }
2792
2793 /*
2794 * Create a new client listener using the given channel @sioc.
2795 * Begin servicing it in a coroutine. When the connection closes, call
2796 * @close_fn with an indication of whether the client completed negotiation.
2797 */
2798 void nbd_client_new(QIOChannelSocket *sioc,
2799 QCryptoTLSCreds *tlscreds,
2800 const char *tlsauthz,
2801 void (*close_fn)(NBDClient *, bool))
2802 {
2803 NBDClient *client;
2804 Coroutine *co;
2805
2806 client = g_new0(NBDClient, 1);
2807 client->refcount = 1;
2808 client->tlscreds = tlscreds;
2809 if (tlscreds) {
2810 object_ref(OBJECT(client->tlscreds));
2811 }
2812 client->tlsauthz = g_strdup(tlsauthz);
2813 client->sioc = sioc;
2814 qio_channel_set_delay(QIO_CHANNEL(sioc), false);
2815 object_ref(OBJECT(client->sioc));
2816 client->ioc = QIO_CHANNEL(sioc);
2817 object_ref(OBJECT(client->ioc));
2818 client->close_fn = close_fn;
2819
2820 co = qemu_coroutine_create(nbd_co_client_start, client);
2821 qemu_coroutine_enter(co);
2822 }
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