2 * Copyright (C) 2016-2018 Red Hat, Inc.
3 * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
5 * Network Block Device Server Side
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.
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.
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/>.
20 #include "qemu/osdep.h"
21 #include "qapi/error.h"
23 #include "nbd-internal.h"
25 #define NBD_META_ID_BASE_ALLOCATION 0
26 #define NBD_META_ID_DIRTY_BITMAP 1
28 /* NBD_MAX_BITMAP_EXTENTS: 1 mb of extents data. An empirical
29 * constant. If an increase is needed, note that the NBD protocol
30 * recommends no larger than 32 mb, so that the client won't consider
31 * the reply as a denial of service attack. */
32 #define NBD_MAX_BITMAP_EXTENTS (0x100000 / 8)
34 static int system_errno_to_nbd_errno(int err
)
62 /* Definitions for opaque data types */
64 typedef struct NBDRequestData NBDRequestData
;
66 struct NBDRequestData
{
67 QSIMPLEQ_ENTRY(NBDRequestData
) entry
;
75 void (*close
)(NBDExport
*exp
);
83 QTAILQ_HEAD(, NBDClient
) clients
;
84 QTAILQ_ENTRY(NBDExport
) next
;
88 BlockBackend
*eject_notifier_blk
;
89 Notifier eject_notifier
;
91 BdrvDirtyBitmap
*export_bitmap
;
92 char *export_bitmap_context
;
95 static QTAILQ_HEAD(, NBDExport
) exports
= QTAILQ_HEAD_INITIALIZER(exports
);
97 /* NBDExportMetaContexts represents a list of contexts to be exported,
98 * as selected by NBD_OPT_SET_META_CONTEXT. Also used for
99 * NBD_OPT_LIST_META_CONTEXT. */
100 typedef struct NBDExportMetaContexts
{
102 bool valid
; /* means that negotiation of the option finished without
104 bool base_allocation
; /* export base:allocation context (block status) */
105 bool bitmap
; /* export qemu:dirty-bitmap:<export bitmap name> */
106 } NBDExportMetaContexts
;
110 void (*close_fn
)(NBDClient
*client
, bool negotiated
);
113 QCryptoTLSCreds
*tlscreds
;
115 QIOChannelSocket
*sioc
; /* The underlying data channel */
116 QIOChannel
*ioc
; /* The current I/O channel which may differ (eg TLS) */
118 Coroutine
*recv_coroutine
;
121 Coroutine
*send_coroutine
;
123 QTAILQ_ENTRY(NBDClient
) next
;
127 bool structured_reply
;
128 NBDExportMetaContexts export_meta
;
130 uint32_t opt
; /* Current option being negotiated */
131 uint32_t optlen
; /* remaining length of data in ioc for the option being
135 static void nbd_client_receive_next_request(NBDClient
*client
);
137 /* Basic flow for negotiation
164 static inline void set_be_option_rep(NBDOptionReply
*rep
, uint32_t option
,
165 uint32_t type
, uint32_t length
)
167 stq_be_p(&rep
->magic
, NBD_REP_MAGIC
);
168 stl_be_p(&rep
->option
, option
);
169 stl_be_p(&rep
->type
, type
);
170 stl_be_p(&rep
->length
, length
);
173 /* Send a reply header, including length, but no payload.
174 * Return -errno on error, 0 on success. */
175 static int nbd_negotiate_send_rep_len(NBDClient
*client
, uint32_t type
,
176 uint32_t len
, Error
**errp
)
180 trace_nbd_negotiate_send_rep_len(client
->opt
, nbd_opt_lookup(client
->opt
),
181 type
, nbd_rep_lookup(type
), len
);
183 assert(len
< NBD_MAX_BUFFER_SIZE
);
185 set_be_option_rep(&rep
, client
->opt
, type
, len
);
186 return nbd_write(client
->ioc
, &rep
, sizeof(rep
), errp
);
189 /* Send a reply header with default 0 length.
190 * Return -errno on error, 0 on success. */
191 static int nbd_negotiate_send_rep(NBDClient
*client
, uint32_t type
,
194 return nbd_negotiate_send_rep_len(client
, type
, 0, errp
);
197 /* Send an error reply.
198 * Return -errno on error, 0 on success. */
199 static int GCC_FMT_ATTR(4, 0)
200 nbd_negotiate_send_rep_verr(NBDClient
*client
, uint32_t type
,
201 Error
**errp
, const char *fmt
, va_list va
)
207 msg
= g_strdup_vprintf(fmt
, va
);
210 trace_nbd_negotiate_send_rep_err(msg
);
211 ret
= nbd_negotiate_send_rep_len(client
, type
, len
, errp
);
215 if (nbd_write(client
->ioc
, msg
, len
, errp
) < 0) {
216 error_prepend(errp
, "write failed (error message): ");
227 /* Send an error reply.
228 * Return -errno on error, 0 on success. */
229 static int GCC_FMT_ATTR(4, 5)
230 nbd_negotiate_send_rep_err(NBDClient
*client
, uint32_t type
,
231 Error
**errp
, const char *fmt
, ...)
237 ret
= nbd_negotiate_send_rep_verr(client
, type
, errp
, fmt
, va
);
242 /* Drop remainder of the current option, and send a reply with the
243 * given error type and message. Return -errno on read or write
244 * failure; or 0 if connection is still live. */
245 static int GCC_FMT_ATTR(4, 0)
246 nbd_opt_vdrop(NBDClient
*client
, uint32_t type
, Error
**errp
,
247 const char *fmt
, va_list va
)
249 int ret
= nbd_drop(client
->ioc
, client
->optlen
, errp
);
253 ret
= nbd_negotiate_send_rep_verr(client
, type
, errp
, fmt
, va
);
258 static int GCC_FMT_ATTR(4, 5)
259 nbd_opt_drop(NBDClient
*client
, uint32_t type
, Error
**errp
,
260 const char *fmt
, ...)
266 ret
= nbd_opt_vdrop(client
, type
, errp
, fmt
, va
);
272 static int GCC_FMT_ATTR(3, 4)
273 nbd_opt_invalid(NBDClient
*client
, Error
**errp
, const char *fmt
, ...)
279 ret
= nbd_opt_vdrop(client
, NBD_REP_ERR_INVALID
, errp
, fmt
, va
);
285 /* Read size bytes from the unparsed payload of the current option.
286 * Return -errno on I/O error, 0 if option was completely handled by
287 * sending a reply about inconsistent lengths, or 1 on success. */
288 static int nbd_opt_read(NBDClient
*client
, void *buffer
, size_t size
,
291 if (size
> client
->optlen
) {
292 return nbd_opt_invalid(client
, errp
,
293 "Inconsistent lengths in option %s",
294 nbd_opt_lookup(client
->opt
));
296 client
->optlen
-= size
;
297 return qio_channel_read_all(client
->ioc
, buffer
, size
, errp
) < 0 ? -EIO
: 1;
300 /* Drop size bytes from the unparsed payload of the current option.
301 * Return -errno on I/O error, 0 if option was completely handled by
302 * sending a reply about inconsistent lengths, or 1 on success. */
303 static int nbd_opt_skip(NBDClient
*client
, size_t size
, Error
**errp
)
305 if (size
> client
->optlen
) {
306 return nbd_opt_invalid(client
, errp
,
307 "Inconsistent lengths in option %s",
308 nbd_opt_lookup(client
->opt
));
310 client
->optlen
-= size
;
311 return nbd_drop(client
->ioc
, size
, errp
) < 0 ? -EIO
: 1;
316 * Read a string with the format:
317 * uint32_t len (<= NBD_MAX_NAME_SIZE)
318 * len bytes string (not 0-terminated)
320 * @name should be enough to store NBD_MAX_NAME_SIZE+1.
321 * If @length is non-null, it will be set to the actual string length.
323 * Return -errno on I/O error, 0 if option was completely handled by
324 * sending a reply about inconsistent lengths, or 1 on success.
326 static int nbd_opt_read_name(NBDClient
*client
, char *name
, uint32_t *length
,
332 ret
= nbd_opt_read(client
, &len
, sizeof(len
), errp
);
336 len
= cpu_to_be32(len
);
338 if (len
> NBD_MAX_NAME_SIZE
) {
339 return nbd_opt_invalid(client
, errp
,
340 "Invalid name length: %" PRIu32
, len
);
343 ret
= nbd_opt_read(client
, name
, len
, errp
);
356 /* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload.
357 * Return -errno on error, 0 on success. */
358 static int nbd_negotiate_send_rep_list(NBDClient
*client
, NBDExport
*exp
,
361 size_t name_len
, desc_len
;
363 const char *name
= exp
->name
? exp
->name
: "";
364 const char *desc
= exp
->description
? exp
->description
: "";
365 QIOChannel
*ioc
= client
->ioc
;
368 trace_nbd_negotiate_send_rep_list(name
, desc
);
369 name_len
= strlen(name
);
370 desc_len
= strlen(desc
);
371 len
= name_len
+ desc_len
+ sizeof(len
);
372 ret
= nbd_negotiate_send_rep_len(client
, NBD_REP_SERVER
, len
, errp
);
377 len
= cpu_to_be32(name_len
);
378 if (nbd_write(ioc
, &len
, sizeof(len
), errp
) < 0) {
379 error_prepend(errp
, "write failed (name length): ");
383 if (nbd_write(ioc
, name
, name_len
, errp
) < 0) {
384 error_prepend(errp
, "write failed (name buffer): ");
388 if (nbd_write(ioc
, desc
, desc_len
, errp
) < 0) {
389 error_prepend(errp
, "write failed (description buffer): ");
396 /* Process the NBD_OPT_LIST command, with a potential series of replies.
397 * Return -errno on error, 0 on success. */
398 static int nbd_negotiate_handle_list(NBDClient
*client
, Error
**errp
)
401 assert(client
->opt
== NBD_OPT_LIST
);
403 /* For each export, send a NBD_REP_SERVER reply. */
404 QTAILQ_FOREACH(exp
, &exports
, next
) {
405 if (nbd_negotiate_send_rep_list(client
, exp
, errp
)) {
409 /* Finish with a NBD_REP_ACK. */
410 return nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
);
413 static void nbd_check_meta_export(NBDClient
*client
)
415 client
->export_meta
.valid
&= client
->exp
== client
->export_meta
.exp
;
418 /* Send a reply to NBD_OPT_EXPORT_NAME.
419 * Return -errno on error, 0 on success. */
420 static int nbd_negotiate_handle_export_name(NBDClient
*client
,
421 uint16_t myflags
, bool no_zeroes
,
424 char name
[NBD_MAX_NAME_SIZE
+ 1];
425 char buf
[NBD_REPLY_EXPORT_NAME_SIZE
] = "";
430 [20 .. xx] export name (length bytes)
433 [ 8 .. 9] export flags
434 [10 .. 133] reserved (0) [unless no_zeroes]
436 trace_nbd_negotiate_handle_export_name();
437 if (client
->optlen
>= sizeof(name
)) {
438 error_setg(errp
, "Bad length received");
441 if (nbd_read(client
->ioc
, name
, client
->optlen
, "export name", errp
) < 0) {
444 name
[client
->optlen
] = '\0';
447 trace_nbd_negotiate_handle_export_name_request(name
);
449 client
->exp
= nbd_export_find(name
);
451 error_setg(errp
, "export not found");
455 trace_nbd_negotiate_new_style_size_flags(client
->exp
->size
,
456 client
->exp
->nbdflags
| myflags
);
457 stq_be_p(buf
, client
->exp
->size
);
458 stw_be_p(buf
+ 8, client
->exp
->nbdflags
| myflags
);
459 len
= no_zeroes
? 10 : sizeof(buf
);
460 ret
= nbd_write(client
->ioc
, buf
, len
, errp
);
462 error_prepend(errp
, "write failed: ");
466 QTAILQ_INSERT_TAIL(&client
->exp
->clients
, client
, next
);
467 nbd_export_get(client
->exp
);
468 nbd_check_meta_export(client
);
473 /* Send a single NBD_REP_INFO, with a buffer @buf of @length bytes.
474 * The buffer does NOT include the info type prefix.
475 * Return -errno on error, 0 if ready to send more. */
476 static int nbd_negotiate_send_info(NBDClient
*client
,
477 uint16_t info
, uint32_t length
, void *buf
,
482 trace_nbd_negotiate_send_info(info
, nbd_info_lookup(info
), length
);
483 rc
= nbd_negotiate_send_rep_len(client
, NBD_REP_INFO
,
484 sizeof(info
) + length
, errp
);
488 info
= cpu_to_be16(info
);
489 if (nbd_write(client
->ioc
, &info
, sizeof(info
), errp
) < 0) {
492 if (nbd_write(client
->ioc
, buf
, length
, errp
) < 0) {
498 /* nbd_reject_length: Handle any unexpected payload.
499 * @fatal requests that we quit talking to the client, even if we are able
500 * to successfully send an error reply.
502 * -errno transmission error occurred or @fatal was requested, errp is set
503 * 0 error message successfully sent to client, errp is not set
505 static int nbd_reject_length(NBDClient
*client
, bool fatal
, Error
**errp
)
509 assert(client
->optlen
);
510 ret
= nbd_opt_invalid(client
, errp
, "option '%s' has unexpected length",
511 nbd_opt_lookup(client
->opt
));
513 error_setg(errp
, "option '%s' has unexpected length",
514 nbd_opt_lookup(client
->opt
));
520 /* Handle NBD_OPT_INFO and NBD_OPT_GO.
521 * Return -errno on error, 0 if ready for next option, and 1 to move
522 * into transmission phase. */
523 static int nbd_negotiate_handle_info(NBDClient
*client
, uint16_t myflags
,
527 char name
[NBD_MAX_NAME_SIZE
+ 1];
532 bool sendname
= false;
533 bool blocksize
= false;
535 char buf
[sizeof(uint64_t) + sizeof(uint16_t)];
538 4 bytes: L, name length (can be 0)
540 2 bytes: N, number of requests (can be 0)
541 N * 2 bytes: N requests
543 rc
= nbd_opt_read_name(client
, name
, &namelen
, errp
);
547 trace_nbd_negotiate_handle_export_name_request(name
);
549 rc
= nbd_opt_read(client
, &requests
, sizeof(requests
), errp
);
553 requests
= be16_to_cpu(requests
);
554 trace_nbd_negotiate_handle_info_requests(requests
);
556 rc
= nbd_opt_read(client
, &request
, sizeof(request
), errp
);
560 request
= be16_to_cpu(request
);
561 trace_nbd_negotiate_handle_info_request(request
,
562 nbd_info_lookup(request
));
563 /* We care about NBD_INFO_NAME and NBD_INFO_BLOCK_SIZE;
564 * everything else is either a request we don't know or
565 * something we send regardless of request */
570 case NBD_INFO_BLOCK_SIZE
:
575 if (client
->optlen
) {
576 return nbd_reject_length(client
, false, errp
);
579 exp
= nbd_export_find(name
);
581 return nbd_negotiate_send_rep_err(client
, NBD_REP_ERR_UNKNOWN
,
582 errp
, "export '%s' not present",
586 /* Don't bother sending NBD_INFO_NAME unless client requested it */
588 rc
= nbd_negotiate_send_info(client
, NBD_INFO_NAME
, namelen
, name
,
595 /* Send NBD_INFO_DESCRIPTION only if available, regardless of
597 if (exp
->description
) {
598 size_t len
= strlen(exp
->description
);
600 rc
= nbd_negotiate_send_info(client
, NBD_INFO_DESCRIPTION
,
601 len
, exp
->description
, errp
);
607 /* Send NBD_INFO_BLOCK_SIZE always, but tweak the minimum size
608 * according to whether the client requested it, and according to
609 * whether this is OPT_INFO or OPT_GO. */
610 /* minimum - 1 for back-compat, or actual if client will obey it. */
611 if (client
->opt
== NBD_OPT_INFO
|| blocksize
) {
612 sizes
[0] = blk_get_request_alignment(exp
->blk
);
616 assert(sizes
[0] <= NBD_MAX_BUFFER_SIZE
);
617 /* preferred - Hard-code to 4096 for now.
618 * TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */
619 sizes
[1] = MAX(4096, sizes
[0]);
620 /* maximum - At most 32M, but smaller as appropriate. */
621 sizes
[2] = MIN(blk_get_max_transfer(exp
->blk
), NBD_MAX_BUFFER_SIZE
);
622 trace_nbd_negotiate_handle_info_block_size(sizes
[0], sizes
[1], sizes
[2]);
623 sizes
[0] = cpu_to_be32(sizes
[0]);
624 sizes
[1] = cpu_to_be32(sizes
[1]);
625 sizes
[2] = cpu_to_be32(sizes
[2]);
626 rc
= nbd_negotiate_send_info(client
, NBD_INFO_BLOCK_SIZE
,
627 sizeof(sizes
), sizes
, errp
);
632 /* Send NBD_INFO_EXPORT always */
633 trace_nbd_negotiate_new_style_size_flags(exp
->size
,
634 exp
->nbdflags
| myflags
);
635 stq_be_p(buf
, exp
->size
);
636 stw_be_p(buf
+ 8, exp
->nbdflags
| myflags
);
637 rc
= nbd_negotiate_send_info(client
, NBD_INFO_EXPORT
,
638 sizeof(buf
), buf
, errp
);
643 /* If the client is just asking for NBD_OPT_INFO, but forgot to
644 * request block sizes, return an error.
645 * TODO: consult blk_bs(blk)->request_align, and only error if it
647 if (client
->opt
== NBD_OPT_INFO
&& !blocksize
) {
648 return nbd_negotiate_send_rep_err(client
,
649 NBD_REP_ERR_BLOCK_SIZE_REQD
,
651 "request NBD_INFO_BLOCK_SIZE to "
656 rc
= nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
);
661 if (client
->opt
== NBD_OPT_GO
) {
663 QTAILQ_INSERT_TAIL(&client
->exp
->clients
, client
, next
);
664 nbd_export_get(client
->exp
);
665 nbd_check_meta_export(client
);
672 /* Handle NBD_OPT_STARTTLS. Return NULL to drop connection, or else the
673 * new channel for all further (now-encrypted) communication. */
674 static QIOChannel
*nbd_negotiate_handle_starttls(NBDClient
*client
,
679 struct NBDTLSHandshakeData data
= { 0 };
681 assert(client
->opt
== NBD_OPT_STARTTLS
);
683 trace_nbd_negotiate_handle_starttls();
686 if (nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
) < 0) {
690 tioc
= qio_channel_tls_new_server(ioc
,
698 qio_channel_set_name(QIO_CHANNEL(tioc
), "nbd-server-tls");
699 trace_nbd_negotiate_handle_starttls_handshake();
700 data
.loop
= g_main_loop_new(g_main_context_default(), FALSE
);
701 qio_channel_tls_handshake(tioc
,
707 if (!data
.complete
) {
708 g_main_loop_run(data
.loop
);
710 g_main_loop_unref(data
.loop
);
712 object_unref(OBJECT(tioc
));
713 error_propagate(errp
, data
.error
);
717 return QIO_CHANNEL(tioc
);
720 /* nbd_negotiate_send_meta_context
722 * Send one chunk of reply to NBD_OPT_{LIST,SET}_META_CONTEXT
724 * For NBD_OPT_LIST_META_CONTEXT @context_id is ignored, 0 is used instead.
726 static int nbd_negotiate_send_meta_context(NBDClient
*client
,
731 NBDOptionReplyMetaContext opt
;
732 struct iovec iov
[] = {
733 {.iov_base
= &opt
, .iov_len
= sizeof(opt
)},
734 {.iov_base
= (void *)context
, .iov_len
= strlen(context
)}
737 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
) {
741 trace_nbd_negotiate_meta_query_reply(context
, context_id
);
742 set_be_option_rep(&opt
.h
, client
->opt
, NBD_REP_META_CONTEXT
,
743 sizeof(opt
) - sizeof(opt
.h
) + iov
[1].iov_len
);
744 stl_be_p(&opt
.context_id
, context_id
);
746 return qio_channel_writev_all(client
->ioc
, iov
, 2, errp
) < 0 ? -EIO
: 0;
749 /* Read strlen(@pattern) bytes, and set @match to true if they match @pattern.
750 * @match is never set to false.
752 * Return -errno on I/O error, 0 if option was completely handled by
753 * sending a reply about inconsistent lengths, or 1 on success.
755 * Note: return code = 1 doesn't mean that we've read exactly @pattern.
756 * It only means that there are no errors.
758 static int nbd_meta_pattern(NBDClient
*client
, const char *pattern
, bool *match
,
763 size_t len
= strlen(pattern
);
767 query
= g_malloc(len
);
768 ret
= nbd_opt_read(client
, query
, len
, errp
);
774 if (strncmp(query
, pattern
, len
) == 0) {
775 trace_nbd_negotiate_meta_query_parse(pattern
);
778 trace_nbd_negotiate_meta_query_skip("pattern not matched");
786 * Read @len bytes, and set @match to true if they match @pattern, or if @len
787 * is 0 and the client is performing _LIST_. @match is never set to false.
789 * Return -errno on I/O error, 0 if option was completely handled by
790 * sending a reply about inconsistent lengths, or 1 on success.
792 * Note: return code = 1 doesn't mean that we've read exactly @pattern.
793 * It only means that there are no errors.
795 static int nbd_meta_empty_or_pattern(NBDClient
*client
, const char *pattern
,
796 uint32_t len
, bool *match
, Error
**errp
)
799 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
) {
802 trace_nbd_negotiate_meta_query_parse("empty");
806 if (len
!= strlen(pattern
)) {
807 trace_nbd_negotiate_meta_query_skip("different lengths");
808 return nbd_opt_skip(client
, len
, errp
);
811 return nbd_meta_pattern(client
, pattern
, match
, errp
);
814 /* nbd_meta_base_query
816 * Handle queries to 'base' namespace. For now, only the base:allocation
817 * context is available. 'len' is the amount of text remaining to be read from
818 * the current name, after the 'base:' portion has been stripped.
820 * Return -errno on I/O error, 0 if option was completely handled by
821 * sending a reply about inconsistent lengths, or 1 on success.
823 static int nbd_meta_base_query(NBDClient
*client
, NBDExportMetaContexts
*meta
,
824 uint32_t len
, Error
**errp
)
826 return nbd_meta_empty_or_pattern(client
, "allocation", len
,
827 &meta
->base_allocation
, errp
);
830 /* nbd_meta_bitmap_query
832 * Handle query to 'qemu:' namespace.
833 * @len is the amount of text remaining to be read from the current name, after
834 * the 'qemu:' portion has been stripped.
836 * Return -errno on I/O error, 0 if option was completely handled by
837 * sending a reply about inconsistent lengths, or 1 on success. */
838 static int nbd_meta_qemu_query(NBDClient
*client
, NBDExportMetaContexts
*meta
,
839 uint32_t len
, Error
**errp
)
841 bool dirty_bitmap
= false;
842 size_t dirty_bitmap_len
= strlen("dirty-bitmap:");
845 if (!meta
->exp
->export_bitmap
) {
846 trace_nbd_negotiate_meta_query_skip("no dirty-bitmap exported");
847 return nbd_opt_skip(client
, len
, errp
);
851 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
) {
854 trace_nbd_negotiate_meta_query_parse("empty");
858 if (len
< dirty_bitmap_len
) {
859 trace_nbd_negotiate_meta_query_skip("not dirty-bitmap:");
860 return nbd_opt_skip(client
, len
, errp
);
863 len
-= dirty_bitmap_len
;
864 ret
= nbd_meta_pattern(client
, "dirty-bitmap:", &dirty_bitmap
, errp
);
869 trace_nbd_negotiate_meta_query_skip("not dirty-bitmap:");
870 return nbd_opt_skip(client
, len
, errp
);
873 trace_nbd_negotiate_meta_query_parse("dirty-bitmap:");
875 return nbd_meta_empty_or_pattern(
876 client
, meta
->exp
->export_bitmap_context
+
877 strlen("qemu:dirty_bitmap:"), len
, &meta
->bitmap
, errp
);
880 /* nbd_negotiate_meta_query
882 * Parse namespace name and call corresponding function to parse body of the
885 * The only supported namespace now is 'base'.
887 * The function aims not wasting time and memory to read long unknown namespace
890 * Return -errno on I/O error, 0 if option was completely handled by
891 * sending a reply about inconsistent lengths, or 1 on success. */
892 static int nbd_negotiate_meta_query(NBDClient
*client
,
893 NBDExportMetaContexts
*meta
, Error
**errp
)
896 * Both 'qemu' and 'base' namespaces have length = 5 including a
897 * colon. If another length namespace is later introduced, this
898 * should certainly be refactored.
905 ret
= nbd_opt_read(client
, &len
, sizeof(len
), errp
);
909 len
= cpu_to_be32(len
);
912 trace_nbd_negotiate_meta_query_skip("length too short");
913 return nbd_opt_skip(client
, len
, errp
);
917 ret
= nbd_opt_read(client
, ns
, ns_len
, errp
);
922 if (!strncmp(ns
, "base:", ns_len
)) {
923 trace_nbd_negotiate_meta_query_parse("base:");
924 return nbd_meta_base_query(client
, meta
, len
, errp
);
925 } else if (!strncmp(ns
, "qemu:", ns_len
)) {
926 trace_nbd_negotiate_meta_query_parse("qemu:");
927 return nbd_meta_qemu_query(client
, meta
, len
, errp
);
930 trace_nbd_negotiate_meta_query_skip("unknown namespace");
931 return nbd_opt_skip(client
, len
, errp
);
934 /* nbd_negotiate_meta_queries
935 * Handle NBD_OPT_LIST_META_CONTEXT and NBD_OPT_SET_META_CONTEXT
937 * Return -errno on I/O error, or 0 if option was completely handled. */
938 static int nbd_negotiate_meta_queries(NBDClient
*client
,
939 NBDExportMetaContexts
*meta
, Error
**errp
)
942 char export_name
[NBD_MAX_NAME_SIZE
+ 1];
943 NBDExportMetaContexts local_meta
;
947 if (!client
->structured_reply
) {
948 return nbd_opt_invalid(client
, errp
,
949 "request option '%s' when structured reply "
951 nbd_opt_lookup(client
->opt
));
954 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
) {
955 /* Only change the caller's meta on SET. */
959 memset(meta
, 0, sizeof(*meta
));
961 ret
= nbd_opt_read_name(client
, export_name
, NULL
, errp
);
966 meta
->exp
= nbd_export_find(export_name
);
967 if (meta
->exp
== NULL
) {
968 return nbd_opt_drop(client
, NBD_REP_ERR_UNKNOWN
, errp
,
969 "export '%s' not present", export_name
);
972 ret
= nbd_opt_read(client
, &nb_queries
, sizeof(nb_queries
), errp
);
976 nb_queries
= cpu_to_be32(nb_queries
);
977 trace_nbd_negotiate_meta_context(nbd_opt_lookup(client
->opt
),
978 export_name
, nb_queries
);
980 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
&& !nb_queries
) {
981 /* enable all known contexts */
982 meta
->base_allocation
= true;
983 meta
->bitmap
= !!meta
->exp
->export_bitmap
;
985 for (i
= 0; i
< nb_queries
; ++i
) {
986 ret
= nbd_negotiate_meta_query(client
, meta
, errp
);
993 if (meta
->base_allocation
) {
994 ret
= nbd_negotiate_send_meta_context(client
, "base:allocation",
995 NBD_META_ID_BASE_ALLOCATION
,
1003 ret
= nbd_negotiate_send_meta_context(client
,
1004 meta
->exp
->export_bitmap_context
,
1005 NBD_META_ID_DIRTY_BITMAP
,
1012 ret
= nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
);
1020 /* nbd_negotiate_options
1021 * Process all NBD_OPT_* client option commands, during fixed newstyle
1024 * -errno on error, errp is set
1025 * 0 on successful negotiation, errp is not set
1026 * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
1029 static int nbd_negotiate_options(NBDClient
*client
, uint16_t myflags
,
1033 bool fixedNewstyle
= false;
1034 bool no_zeroes
= false;
1037 [ 0 .. 3] client flags
1039 Then we loop until NBD_OPT_EXPORT_NAME or NBD_OPT_GO:
1040 [ 0 .. 7] NBD_OPTS_MAGIC
1041 [ 8 .. 11] NBD option
1042 [12 .. 15] Data length
1045 [ 0 .. 7] NBD_OPTS_MAGIC
1046 [ 8 .. 11] Second NBD option
1047 [12 .. 15] Data length
1051 if (nbd_read32(client
->ioc
, &flags
, "flags", errp
) < 0) {
1054 trace_nbd_negotiate_options_flags(flags
);
1055 if (flags
& NBD_FLAG_C_FIXED_NEWSTYLE
) {
1056 fixedNewstyle
= true;
1057 flags
&= ~NBD_FLAG_C_FIXED_NEWSTYLE
;
1059 if (flags
& NBD_FLAG_C_NO_ZEROES
) {
1061 flags
&= ~NBD_FLAG_C_NO_ZEROES
;
1064 error_setg(errp
, "Unknown client flags 0x%" PRIx32
" received", flags
);
1070 uint32_t option
, length
;
1073 if (nbd_read64(client
->ioc
, &magic
, "opts magic", errp
) < 0) {
1076 trace_nbd_negotiate_options_check_magic(magic
);
1077 if (magic
!= NBD_OPTS_MAGIC
) {
1078 error_setg(errp
, "Bad magic received");
1082 if (nbd_read32(client
->ioc
, &option
, "option", errp
) < 0) {
1085 client
->opt
= option
;
1087 if (nbd_read32(client
->ioc
, &length
, "option length", errp
) < 0) {
1090 assert(!client
->optlen
);
1091 client
->optlen
= length
;
1093 if (length
> NBD_MAX_BUFFER_SIZE
) {
1094 error_setg(errp
, "len (%" PRIu32
" ) is larger than max len (%u)",
1095 length
, NBD_MAX_BUFFER_SIZE
);
1099 trace_nbd_negotiate_options_check_option(option
,
1100 nbd_opt_lookup(option
));
1101 if (client
->tlscreds
&&
1102 client
->ioc
== (QIOChannel
*)client
->sioc
) {
1104 if (!fixedNewstyle
) {
1105 error_setg(errp
, "Unsupported option 0x%" PRIx32
, option
);
1109 case NBD_OPT_STARTTLS
:
1111 /* Unconditionally drop the connection if the client
1112 * can't start a TLS negotiation correctly */
1113 return nbd_reject_length(client
, true, errp
);
1115 tioc
= nbd_negotiate_handle_starttls(client
, errp
);
1120 object_unref(OBJECT(client
->ioc
));
1121 client
->ioc
= QIO_CHANNEL(tioc
);
1124 case NBD_OPT_EXPORT_NAME
:
1125 /* No way to return an error to client, so drop connection */
1126 error_setg(errp
, "Option 0x%x not permitted before TLS",
1131 /* Let the client keep trying, unless they asked to
1132 * quit. Always try to give an error back to the
1133 * client; but when replying to OPT_ABORT, be aware
1134 * that the client may hang up before receiving the
1135 * error, in which case we are fine ignoring the
1136 * resulting EPIPE. */
1137 ret
= nbd_opt_drop(client
, NBD_REP_ERR_TLS_REQD
,
1138 option
== NBD_OPT_ABORT
? NULL
: errp
,
1140 " not permitted before TLS", option
);
1141 if (option
== NBD_OPT_ABORT
) {
1146 } else if (fixedNewstyle
) {
1150 ret
= nbd_reject_length(client
, false, errp
);
1152 ret
= nbd_negotiate_handle_list(client
, errp
);
1157 /* NBD spec says we must try to reply before
1158 * disconnecting, but that we must also tolerate
1159 * guests that don't wait for our reply. */
1160 nbd_negotiate_send_rep(client
, NBD_REP_ACK
, NULL
);
1163 case NBD_OPT_EXPORT_NAME
:
1164 return nbd_negotiate_handle_export_name(client
,
1170 ret
= nbd_negotiate_handle_info(client
, myflags
, errp
);
1172 assert(option
== NBD_OPT_GO
);
1177 case NBD_OPT_STARTTLS
:
1179 ret
= nbd_reject_length(client
, false, errp
);
1180 } else if (client
->tlscreds
) {
1181 ret
= nbd_negotiate_send_rep_err(client
,
1182 NBD_REP_ERR_INVALID
, errp
,
1183 "TLS already enabled");
1185 ret
= nbd_negotiate_send_rep_err(client
,
1186 NBD_REP_ERR_POLICY
, errp
,
1187 "TLS not configured");
1191 case NBD_OPT_STRUCTURED_REPLY
:
1193 ret
= nbd_reject_length(client
, false, errp
);
1194 } else if (client
->structured_reply
) {
1195 ret
= nbd_negotiate_send_rep_err(
1196 client
, NBD_REP_ERR_INVALID
, errp
,
1197 "structured reply already negotiated");
1199 ret
= nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
);
1200 client
->structured_reply
= true;
1201 myflags
|= NBD_FLAG_SEND_DF
;
1205 case NBD_OPT_LIST_META_CONTEXT
:
1206 case NBD_OPT_SET_META_CONTEXT
:
1207 ret
= nbd_negotiate_meta_queries(client
, &client
->export_meta
,
1212 ret
= nbd_opt_drop(client
, NBD_REP_ERR_UNSUP
, errp
,
1213 "Unsupported option %" PRIu32
" (%s)",
1214 option
, nbd_opt_lookup(option
));
1219 * If broken new-style we should drop the connection
1220 * for anything except NBD_OPT_EXPORT_NAME
1223 case NBD_OPT_EXPORT_NAME
:
1224 return nbd_negotiate_handle_export_name(client
,
1229 error_setg(errp
, "Unsupported option %" PRIu32
" (%s)",
1230 option
, nbd_opt_lookup(option
));
1242 * -errno on error, errp is set
1243 * 0 on successful negotiation, errp is not set
1244 * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
1247 static coroutine_fn
int nbd_negotiate(NBDClient
*client
, Error
**errp
)
1249 char buf
[NBD_OLDSTYLE_NEGOTIATE_SIZE
] = "";
1251 const uint16_t myflags
= (NBD_FLAG_HAS_FLAGS
| NBD_FLAG_SEND_TRIM
|
1252 NBD_FLAG_SEND_FLUSH
| NBD_FLAG_SEND_FUA
|
1253 NBD_FLAG_SEND_WRITE_ZEROES
| NBD_FLAG_SEND_CACHE
);
1255 /* Old style negotiation header, no room for options
1256 [ 0 .. 7] passwd ("NBDMAGIC")
1257 [ 8 .. 15] magic (NBD_CLIENT_MAGIC)
1259 [24 .. 27] export flags (zero-extended)
1260 [28 .. 151] reserved (0)
1262 New style negotiation header, client can send options
1263 [ 0 .. 7] passwd ("NBDMAGIC")
1264 [ 8 .. 15] magic (NBD_OPTS_MAGIC)
1265 [16 .. 17] server flags (0)
1266 ....options sent, ending in NBD_OPT_EXPORT_NAME or NBD_OPT_GO....
1269 qio_channel_set_blocking(client
->ioc
, false, NULL
);
1271 trace_nbd_negotiate_begin();
1272 memcpy(buf
, "NBDMAGIC", 8);
1274 stq_be_p(buf
+ 8, NBD_OPTS_MAGIC
);
1275 stw_be_p(buf
+ 16, NBD_FLAG_FIXED_NEWSTYLE
| NBD_FLAG_NO_ZEROES
);
1277 if (nbd_write(client
->ioc
, buf
, 18, errp
) < 0) {
1278 error_prepend(errp
, "write failed: ");
1281 ret
= nbd_negotiate_options(client
, myflags
, errp
);
1284 error_prepend(errp
, "option negotiation failed: ");
1289 assert(!client
->optlen
);
1290 trace_nbd_negotiate_success();
1295 static int nbd_receive_request(QIOChannel
*ioc
, NBDRequest
*request
,
1298 uint8_t buf
[NBD_REQUEST_SIZE
];
1302 ret
= nbd_read(ioc
, buf
, sizeof(buf
), "request", errp
);
1308 [ 0 .. 3] magic (NBD_REQUEST_MAGIC)
1309 [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...)
1310 [ 6 .. 7] type (NBD_CMD_READ, ...)
1316 magic
= ldl_be_p(buf
);
1317 request
->flags
= lduw_be_p(buf
+ 4);
1318 request
->type
= lduw_be_p(buf
+ 6);
1319 request
->handle
= ldq_be_p(buf
+ 8);
1320 request
->from
= ldq_be_p(buf
+ 16);
1321 request
->len
= ldl_be_p(buf
+ 24);
1323 trace_nbd_receive_request(magic
, request
->flags
, request
->type
,
1324 request
->from
, request
->len
);
1326 if (magic
!= NBD_REQUEST_MAGIC
) {
1327 error_setg(errp
, "invalid magic (got 0x%" PRIx32
")", magic
);
1333 #define MAX_NBD_REQUESTS 16
1335 void nbd_client_get(NBDClient
*client
)
1340 void nbd_client_put(NBDClient
*client
)
1342 if (--client
->refcount
== 0) {
1343 /* The last reference should be dropped by client->close,
1344 * which is called by client_close.
1346 assert(client
->closing
);
1348 qio_channel_detach_aio_context(client
->ioc
);
1349 object_unref(OBJECT(client
->sioc
));
1350 object_unref(OBJECT(client
->ioc
));
1351 if (client
->tlscreds
) {
1352 object_unref(OBJECT(client
->tlscreds
));
1354 g_free(client
->tlsauthz
);
1356 QTAILQ_REMOVE(&client
->exp
->clients
, client
, next
);
1357 nbd_export_put(client
->exp
);
1363 static void client_close(NBDClient
*client
, bool negotiated
)
1365 if (client
->closing
) {
1369 client
->closing
= true;
1371 /* Force requests to finish. They will drop their own references,
1372 * then we'll close the socket and free the NBDClient.
1374 qio_channel_shutdown(client
->ioc
, QIO_CHANNEL_SHUTDOWN_BOTH
,
1377 /* Also tell the client, so that they release their reference. */
1378 if (client
->close_fn
) {
1379 client
->close_fn(client
, negotiated
);
1383 static NBDRequestData
*nbd_request_get(NBDClient
*client
)
1385 NBDRequestData
*req
;
1387 assert(client
->nb_requests
<= MAX_NBD_REQUESTS
- 1);
1388 client
->nb_requests
++;
1390 req
= g_new0(NBDRequestData
, 1);
1391 nbd_client_get(client
);
1392 req
->client
= client
;
1396 static void nbd_request_put(NBDRequestData
*req
)
1398 NBDClient
*client
= req
->client
;
1401 qemu_vfree(req
->data
);
1405 client
->nb_requests
--;
1406 nbd_client_receive_next_request(client
);
1408 nbd_client_put(client
);
1411 static void blk_aio_attached(AioContext
*ctx
, void *opaque
)
1413 NBDExport
*exp
= opaque
;
1416 trace_nbd_blk_aio_attached(exp
->name
, ctx
);
1420 QTAILQ_FOREACH(client
, &exp
->clients
, next
) {
1421 qio_channel_attach_aio_context(client
->ioc
, ctx
);
1422 if (client
->recv_coroutine
) {
1423 aio_co_schedule(ctx
, client
->recv_coroutine
);
1425 if (client
->send_coroutine
) {
1426 aio_co_schedule(ctx
, client
->send_coroutine
);
1431 static void blk_aio_detach(void *opaque
)
1433 NBDExport
*exp
= opaque
;
1436 trace_nbd_blk_aio_detach(exp
->name
, exp
->ctx
);
1438 QTAILQ_FOREACH(client
, &exp
->clients
, next
) {
1439 qio_channel_detach_aio_context(client
->ioc
);
1445 static void nbd_eject_notifier(Notifier
*n
, void *data
)
1447 NBDExport
*exp
= container_of(n
, NBDExport
, eject_notifier
);
1448 nbd_export_close(exp
);
1451 NBDExport
*nbd_export_new(BlockDriverState
*bs
, uint64_t dev_offset
,
1452 uint64_t size
, const char *name
, const char *desc
,
1453 const char *bitmap
, uint16_t nbdflags
,
1454 void (*close
)(NBDExport
*), bool writethrough
,
1455 BlockBackend
*on_eject_blk
, Error
**errp
)
1459 NBDExport
*exp
= g_new0(NBDExport
, 1);
1464 * NBD exports are used for non-shared storage migration. Make sure
1465 * that BDRV_O_INACTIVE is cleared and the image is ready for write
1466 * access since the export could be available before migration handover.
1469 ctx
= bdrv_get_aio_context(bs
);
1470 aio_context_acquire(ctx
);
1471 bdrv_invalidate_cache(bs
, NULL
);
1472 aio_context_release(ctx
);
1474 /* Don't allow resize while the NBD server is running, otherwise we don't
1475 * care what happens with the node. */
1476 perm
= BLK_PERM_CONSISTENT_READ
;
1477 if ((nbdflags
& NBD_FLAG_READ_ONLY
) == 0) {
1478 perm
|= BLK_PERM_WRITE
;
1480 blk
= blk_new(perm
, BLK_PERM_CONSISTENT_READ
| BLK_PERM_WRITE_UNCHANGED
|
1481 BLK_PERM_WRITE
| BLK_PERM_GRAPH_MOD
);
1482 ret
= blk_insert_bs(blk
, bs
, errp
);
1486 blk_set_enable_write_cache(blk
, !writethrough
);
1489 QTAILQ_INIT(&exp
->clients
);
1491 assert(dev_offset
<= INT64_MAX
);
1492 exp
->dev_offset
= dev_offset
;
1493 exp
->name
= g_strdup(name
);
1494 exp
->description
= g_strdup(desc
);
1495 exp
->nbdflags
= nbdflags
;
1496 assert(size
<= INT64_MAX
- dev_offset
);
1497 exp
->size
= QEMU_ALIGN_DOWN(size
, BDRV_SECTOR_SIZE
);
1500 BdrvDirtyBitmap
*bm
= NULL
;
1503 bm
= bdrv_find_dirty_bitmap(bs
, bitmap
);
1504 if (bm
!= NULL
|| bs
->backing
== NULL
) {
1508 bs
= bs
->backing
->bs
;
1512 error_setg(errp
, "Bitmap '%s' is not found", bitmap
);
1516 if (bdrv_dirty_bitmap_check(bm
, BDRV_BITMAP_ALLOW_RO
, errp
)) {
1520 if ((nbdflags
& NBD_FLAG_READ_ONLY
) && bdrv_is_writable(bs
) &&
1521 bdrv_dirty_bitmap_enabled(bm
)) {
1523 "Enabled bitmap '%s' incompatible with readonly export",
1528 bdrv_dirty_bitmap_set_busy(bm
, true);
1529 exp
->export_bitmap
= bm
;
1530 exp
->export_bitmap_context
= g_strdup_printf("qemu:dirty-bitmap:%s",
1535 exp
->ctx
= blk_get_aio_context(blk
);
1536 blk_add_aio_context_notifier(blk
, blk_aio_attached
, blk_aio_detach
, exp
);
1539 blk_ref(on_eject_blk
);
1540 exp
->eject_notifier_blk
= on_eject_blk
;
1541 exp
->eject_notifier
.notify
= nbd_eject_notifier
;
1542 blk_add_remove_bs_notifier(on_eject_blk
, &exp
->eject_notifier
);
1544 QTAILQ_INSERT_TAIL(&exports
, exp
, next
);
1545 nbd_export_get(exp
);
1551 g_free(exp
->description
);
1556 NBDExport
*nbd_export_find(const char *name
)
1559 QTAILQ_FOREACH(exp
, &exports
, next
) {
1560 if (strcmp(name
, exp
->name
) == 0) {
1568 void nbd_export_close(NBDExport
*exp
)
1570 NBDClient
*client
, *next
;
1572 nbd_export_get(exp
);
1574 * TODO: Should we expand QMP NbdServerRemoveNode enum to allow a
1575 * close mode that stops advertising the export to new clients but
1576 * still permits existing clients to run to completion? Because of
1577 * that possibility, nbd_export_close() can be called more than
1578 * once on an export.
1580 QTAILQ_FOREACH_SAFE(client
, &exp
->clients
, next
, next
) {
1581 client_close(client
, true);
1584 nbd_export_put(exp
);
1587 QTAILQ_REMOVE(&exports
, exp
, next
);
1589 g_free(exp
->description
);
1590 exp
->description
= NULL
;
1591 nbd_export_put(exp
);
1594 void nbd_export_remove(NBDExport
*exp
, NbdServerRemoveMode mode
, Error
**errp
)
1596 if (mode
== NBD_SERVER_REMOVE_MODE_HARD
|| QTAILQ_EMPTY(&exp
->clients
)) {
1597 nbd_export_close(exp
);
1601 assert(mode
== NBD_SERVER_REMOVE_MODE_SAFE
);
1603 error_setg(errp
, "export '%s' still in use", exp
->name
);
1604 error_append_hint(errp
, "Use mode='hard' to force client disconnect\n");
1607 void nbd_export_get(NBDExport
*exp
)
1609 assert(exp
->refcount
> 0);
1613 void nbd_export_put(NBDExport
*exp
)
1615 assert(exp
->refcount
> 0);
1616 if (exp
->refcount
== 1) {
1617 nbd_export_close(exp
);
1620 /* nbd_export_close() may theoretically reduce refcount to 0. It may happen
1621 * if someone calls nbd_export_put() on named export not through
1622 * nbd_export_set_name() when refcount is 1. So, let's assert that
1625 assert(exp
->refcount
> 0);
1626 if (--exp
->refcount
== 0) {
1627 assert(exp
->name
== NULL
);
1628 assert(exp
->description
== NULL
);
1635 if (exp
->eject_notifier_blk
) {
1636 notifier_remove(&exp
->eject_notifier
);
1637 blk_unref(exp
->eject_notifier_blk
);
1639 blk_remove_aio_context_notifier(exp
->blk
, blk_aio_attached
,
1640 blk_aio_detach
, exp
);
1641 blk_unref(exp
->blk
);
1645 if (exp
->export_bitmap
) {
1646 bdrv_dirty_bitmap_set_busy(exp
->export_bitmap
, false);
1647 g_free(exp
->export_bitmap_context
);
1654 BlockBackend
*nbd_export_get_blockdev(NBDExport
*exp
)
1659 void nbd_export_close_all(void)
1661 NBDExport
*exp
, *next
;
1663 QTAILQ_FOREACH_SAFE(exp
, &exports
, next
, next
) {
1664 nbd_export_close(exp
);
1668 static int coroutine_fn
nbd_co_send_iov(NBDClient
*client
, struct iovec
*iov
,
1669 unsigned niov
, Error
**errp
)
1673 g_assert(qemu_in_coroutine());
1674 qemu_co_mutex_lock(&client
->send_lock
);
1675 client
->send_coroutine
= qemu_coroutine_self();
1677 ret
= qio_channel_writev_all(client
->ioc
, iov
, niov
, errp
) < 0 ? -EIO
: 0;
1679 client
->send_coroutine
= NULL
;
1680 qemu_co_mutex_unlock(&client
->send_lock
);
1685 static inline void set_be_simple_reply(NBDSimpleReply
*reply
, uint64_t error
,
1688 stl_be_p(&reply
->magic
, NBD_SIMPLE_REPLY_MAGIC
);
1689 stl_be_p(&reply
->error
, error
);
1690 stq_be_p(&reply
->handle
, handle
);
1693 static int nbd_co_send_simple_reply(NBDClient
*client
,
1700 NBDSimpleReply reply
;
1701 int nbd_err
= system_errno_to_nbd_errno(error
);
1702 struct iovec iov
[] = {
1703 {.iov_base
= &reply
, .iov_len
= sizeof(reply
)},
1704 {.iov_base
= data
, .iov_len
= len
}
1707 trace_nbd_co_send_simple_reply(handle
, nbd_err
, nbd_err_lookup(nbd_err
),
1709 set_be_simple_reply(&reply
, nbd_err
, handle
);
1711 return nbd_co_send_iov(client
, iov
, len
? 2 : 1, errp
);
1714 static inline void set_be_chunk(NBDStructuredReplyChunk
*chunk
, uint16_t flags
,
1715 uint16_t type
, uint64_t handle
, uint32_t length
)
1717 stl_be_p(&chunk
->magic
, NBD_STRUCTURED_REPLY_MAGIC
);
1718 stw_be_p(&chunk
->flags
, flags
);
1719 stw_be_p(&chunk
->type
, type
);
1720 stq_be_p(&chunk
->handle
, handle
);
1721 stl_be_p(&chunk
->length
, length
);
1724 static int coroutine_fn
nbd_co_send_structured_done(NBDClient
*client
,
1728 NBDStructuredReplyChunk chunk
;
1729 struct iovec iov
[] = {
1730 {.iov_base
= &chunk
, .iov_len
= sizeof(chunk
)},
1733 trace_nbd_co_send_structured_done(handle
);
1734 set_be_chunk(&chunk
, NBD_REPLY_FLAG_DONE
, NBD_REPLY_TYPE_NONE
, handle
, 0);
1736 return nbd_co_send_iov(client
, iov
, 1, errp
);
1739 static int coroutine_fn
nbd_co_send_structured_read(NBDClient
*client
,
1747 NBDStructuredReadData chunk
;
1748 struct iovec iov
[] = {
1749 {.iov_base
= &chunk
, .iov_len
= sizeof(chunk
)},
1750 {.iov_base
= data
, .iov_len
= size
}
1754 trace_nbd_co_send_structured_read(handle
, offset
, data
, size
);
1755 set_be_chunk(&chunk
.h
, final
? NBD_REPLY_FLAG_DONE
: 0,
1756 NBD_REPLY_TYPE_OFFSET_DATA
, handle
,
1757 sizeof(chunk
) - sizeof(chunk
.h
) + size
);
1758 stq_be_p(&chunk
.offset
, offset
);
1760 return nbd_co_send_iov(client
, iov
, 2, errp
);
1763 static int coroutine_fn
nbd_co_send_structured_error(NBDClient
*client
,
1769 NBDStructuredError chunk
;
1770 int nbd_err
= system_errno_to_nbd_errno(error
);
1771 struct iovec iov
[] = {
1772 {.iov_base
= &chunk
, .iov_len
= sizeof(chunk
)},
1773 {.iov_base
= (char *)msg
, .iov_len
= msg
? strlen(msg
) : 0},
1777 trace_nbd_co_send_structured_error(handle
, nbd_err
,
1778 nbd_err_lookup(nbd_err
), msg
? msg
: "");
1779 set_be_chunk(&chunk
.h
, NBD_REPLY_FLAG_DONE
, NBD_REPLY_TYPE_ERROR
, handle
,
1780 sizeof(chunk
) - sizeof(chunk
.h
) + iov
[1].iov_len
);
1781 stl_be_p(&chunk
.error
, nbd_err
);
1782 stw_be_p(&chunk
.message_length
, iov
[1].iov_len
);
1784 return nbd_co_send_iov(client
, iov
, 1 + !!iov
[1].iov_len
, errp
);
1787 /* Do a sparse read and send the structured reply to the client.
1788 * Returns -errno if sending fails. bdrv_block_status_above() failure is
1789 * reported to the client, at which point this function succeeds.
1791 static int coroutine_fn
nbd_co_send_sparse_read(NBDClient
*client
,
1799 NBDExport
*exp
= client
->exp
;
1800 size_t progress
= 0;
1802 while (progress
< size
) {
1804 int status
= bdrv_block_status_above(blk_bs(exp
->blk
), NULL
,
1806 size
- progress
, &pnum
, NULL
,
1811 char *msg
= g_strdup_printf("unable to check for holes: %s",
1814 ret
= nbd_co_send_structured_error(client
, handle
, -status
, msg
,
1819 assert(pnum
&& pnum
<= size
- progress
);
1820 final
= progress
+ pnum
== size
;
1821 if (status
& BDRV_BLOCK_ZERO
) {
1822 NBDStructuredReadHole chunk
;
1823 struct iovec iov
[] = {
1824 {.iov_base
= &chunk
, .iov_len
= sizeof(chunk
)},
1827 trace_nbd_co_send_structured_read_hole(handle
, offset
+ progress
,
1829 set_be_chunk(&chunk
.h
, final
? NBD_REPLY_FLAG_DONE
: 0,
1830 NBD_REPLY_TYPE_OFFSET_HOLE
,
1831 handle
, sizeof(chunk
) - sizeof(chunk
.h
));
1832 stq_be_p(&chunk
.offset
, offset
+ progress
);
1833 stl_be_p(&chunk
.length
, pnum
);
1834 ret
= nbd_co_send_iov(client
, iov
, 1, errp
);
1836 ret
= blk_pread(exp
->blk
, offset
+ progress
+ exp
->dev_offset
,
1837 data
+ progress
, pnum
);
1839 error_setg_errno(errp
, -ret
, "reading from file failed");
1842 ret
= nbd_co_send_structured_read(client
, handle
, offset
+ progress
,
1843 data
+ progress
, pnum
, final
,
1856 * Populate @extents from block status. Update @bytes to be the actual
1857 * length encoded (which may be smaller than the original), and update
1858 * @nb_extents to the number of extents used.
1860 * Returns zero on success and -errno on bdrv_block_status_above failure.
1862 static int blockstatus_to_extents(BlockDriverState
*bs
, uint64_t offset
,
1863 uint64_t *bytes
, NBDExtent
*extents
,
1864 unsigned int *nb_extents
)
1866 uint64_t remaining_bytes
= *bytes
;
1867 NBDExtent
*extent
= extents
, *extents_end
= extents
+ *nb_extents
;
1868 bool first_extent
= true;
1870 assert(*nb_extents
);
1871 while (remaining_bytes
) {
1874 int ret
= bdrv_block_status_above(bs
, NULL
, offset
, remaining_bytes
,
1881 flags
= (ret
& BDRV_BLOCK_ALLOCATED
? 0 : NBD_STATE_HOLE
) |
1882 (ret
& BDRV_BLOCK_ZERO
? NBD_STATE_ZERO
: 0);
1884 remaining_bytes
-= num
;
1887 extent
->flags
= flags
;
1888 extent
->length
= num
;
1889 first_extent
= false;
1893 if (flags
== extent
->flags
) {
1894 /* extend current extent */
1895 extent
->length
+= num
;
1897 if (extent
+ 1 == extents_end
) {
1901 /* start new extent */
1903 extent
->flags
= flags
;
1904 extent
->length
= num
;
1908 extents_end
= extent
+ 1;
1910 for (extent
= extents
; extent
< extents_end
; extent
++) {
1911 extent
->flags
= cpu_to_be32(extent
->flags
);
1912 extent
->length
= cpu_to_be32(extent
->length
);
1915 *bytes
-= remaining_bytes
;
1916 *nb_extents
= extents_end
- extents
;
1921 /* nbd_co_send_extents
1923 * @length is only for tracing purposes (and may be smaller or larger
1924 * than the client's original request). @last controls whether
1925 * NBD_REPLY_FLAG_DONE is sent. @extents should already be in
1926 * big-endian format.
1928 static int nbd_co_send_extents(NBDClient
*client
, uint64_t handle
,
1929 NBDExtent
*extents
, unsigned int nb_extents
,
1930 uint64_t length
, bool last
,
1931 uint32_t context_id
, Error
**errp
)
1933 NBDStructuredMeta chunk
;
1935 struct iovec iov
[] = {
1936 {.iov_base
= &chunk
, .iov_len
= sizeof(chunk
)},
1937 {.iov_base
= extents
, .iov_len
= nb_extents
* sizeof(extents
[0])}
1940 trace_nbd_co_send_extents(handle
, nb_extents
, context_id
, length
, last
);
1941 set_be_chunk(&chunk
.h
, last
? NBD_REPLY_FLAG_DONE
: 0,
1942 NBD_REPLY_TYPE_BLOCK_STATUS
,
1943 handle
, sizeof(chunk
) - sizeof(chunk
.h
) + iov
[1].iov_len
);
1944 stl_be_p(&chunk
.context_id
, context_id
);
1946 return nbd_co_send_iov(client
, iov
, 2, errp
);
1949 /* Get block status from the exported device and send it to the client */
1950 static int nbd_co_send_block_status(NBDClient
*client
, uint64_t handle
,
1951 BlockDriverState
*bs
, uint64_t offset
,
1952 uint32_t length
, bool dont_fragment
,
1953 bool last
, uint32_t context_id
,
1957 unsigned int nb_extents
= dont_fragment
? 1 : NBD_MAX_BITMAP_EXTENTS
;
1958 NBDExtent
*extents
= g_new(NBDExtent
, nb_extents
);
1959 uint64_t final_length
= length
;
1961 ret
= blockstatus_to_extents(bs
, offset
, &final_length
, extents
,
1965 return nbd_co_send_structured_error(
1966 client
, handle
, -ret
, "can't get block status", errp
);
1969 ret
= nbd_co_send_extents(client
, handle
, extents
, nb_extents
,
1970 final_length
, last
, context_id
, errp
);
1978 * Populate @extents from a dirty bitmap. Unless @dont_fragment, the
1979 * final extent may exceed the original @length. Store in @length the
1980 * byte length encoded (which may be smaller or larger than the
1981 * original), and return the number of extents used.
1983 static unsigned int bitmap_to_extents(BdrvDirtyBitmap
*bitmap
, uint64_t offset
,
1984 uint64_t *length
, NBDExtent
*extents
,
1985 unsigned int nb_extents
,
1988 uint64_t begin
= offset
, end
= offset
;
1989 uint64_t overall_end
= offset
+ *length
;
1991 BdrvDirtyBitmapIter
*it
;
1994 bdrv_dirty_bitmap_lock(bitmap
);
1996 it
= bdrv_dirty_iter_new(bitmap
);
1997 dirty
= bdrv_get_dirty_locked(NULL
, bitmap
, offset
);
1999 assert(begin
< overall_end
&& nb_extents
);
2000 while (begin
< overall_end
&& i
< nb_extents
) {
2001 bool next_dirty
= !dirty
;
2004 end
= bdrv_dirty_bitmap_next_zero(bitmap
, begin
, UINT64_MAX
);
2006 bdrv_set_dirty_iter(it
, begin
);
2007 end
= bdrv_dirty_iter_next(it
);
2009 if (end
== -1 || end
- begin
> UINT32_MAX
) {
2010 /* Cap to an aligned value < 4G beyond begin. */
2011 end
= MIN(bdrv_dirty_bitmap_size(bitmap
),
2012 begin
+ UINT32_MAX
+ 1 -
2013 bdrv_dirty_bitmap_granularity(bitmap
));
2016 if (dont_fragment
&& end
> overall_end
) {
2020 extents
[i
].length
= cpu_to_be32(end
- begin
);
2021 extents
[i
].flags
= cpu_to_be32(dirty
? NBD_STATE_DIRTY
: 0);
2027 bdrv_dirty_iter_free(it
);
2029 bdrv_dirty_bitmap_unlock(bitmap
);
2031 assert(offset
< end
);
2032 *length
= end
- offset
;
2036 static int nbd_co_send_bitmap(NBDClient
*client
, uint64_t handle
,
2037 BdrvDirtyBitmap
*bitmap
, uint64_t offset
,
2038 uint32_t length
, bool dont_fragment
, bool last
,
2039 uint32_t context_id
, Error
**errp
)
2042 unsigned int nb_extents
= dont_fragment
? 1 : NBD_MAX_BITMAP_EXTENTS
;
2043 NBDExtent
*extents
= g_new(NBDExtent
, nb_extents
);
2044 uint64_t final_length
= length
;
2046 nb_extents
= bitmap_to_extents(bitmap
, offset
, &final_length
, extents
,
2047 nb_extents
, dont_fragment
);
2049 ret
= nbd_co_send_extents(client
, handle
, extents
, nb_extents
,
2050 final_length
, last
, context_id
, errp
);
2057 /* nbd_co_receive_request
2058 * Collect a client request. Return 0 if request looks valid, -EIO to drop
2059 * connection right away, and any other negative value to report an error to
2060 * the client (although the caller may still need to disconnect after reporting
2063 static int nbd_co_receive_request(NBDRequestData
*req
, NBDRequest
*request
,
2066 NBDClient
*client
= req
->client
;
2069 g_assert(qemu_in_coroutine());
2070 assert(client
->recv_coroutine
== qemu_coroutine_self());
2071 if (nbd_receive_request(client
->ioc
, request
, errp
) < 0) {
2075 trace_nbd_co_receive_request_decode_type(request
->handle
, request
->type
,
2076 nbd_cmd_lookup(request
->type
));
2078 if (request
->type
!= NBD_CMD_WRITE
) {
2079 /* No payload, we are ready to read the next request. */
2080 req
->complete
= true;
2083 if (request
->type
== NBD_CMD_DISC
) {
2084 /* Special case: we're going to disconnect without a reply,
2085 * whether or not flags, from, or len are bogus */
2089 if (request
->type
== NBD_CMD_READ
|| request
->type
== NBD_CMD_WRITE
||
2090 request
->type
== NBD_CMD_CACHE
)
2092 if (request
->len
> NBD_MAX_BUFFER_SIZE
) {
2093 error_setg(errp
, "len (%" PRIu32
" ) is larger than max len (%u)",
2094 request
->len
, NBD_MAX_BUFFER_SIZE
);
2098 req
->data
= blk_try_blockalign(client
->exp
->blk
, request
->len
);
2099 if (req
->data
== NULL
) {
2100 error_setg(errp
, "No memory");
2104 if (request
->type
== NBD_CMD_WRITE
) {
2105 if (nbd_read(client
->ioc
, req
->data
, request
->len
, "CMD_WRITE data",
2110 req
->complete
= true;
2112 trace_nbd_co_receive_request_payload_received(request
->handle
,
2116 /* Sanity checks. */
2117 if (client
->exp
->nbdflags
& NBD_FLAG_READ_ONLY
&&
2118 (request
->type
== NBD_CMD_WRITE
||
2119 request
->type
== NBD_CMD_WRITE_ZEROES
||
2120 request
->type
== NBD_CMD_TRIM
)) {
2121 error_setg(errp
, "Export is read-only");
2124 if (request
->from
> client
->exp
->size
||
2125 request
->len
> client
->exp
->size
- request
->from
) {
2126 error_setg(errp
, "operation past EOF; From: %" PRIu64
", Len: %" PRIu32
2127 ", Size: %" PRIu64
, request
->from
, request
->len
,
2129 return (request
->type
== NBD_CMD_WRITE
||
2130 request
->type
== NBD_CMD_WRITE_ZEROES
) ? -ENOSPC
: -EINVAL
;
2132 valid_flags
= NBD_CMD_FLAG_FUA
;
2133 if (request
->type
== NBD_CMD_READ
&& client
->structured_reply
) {
2134 valid_flags
|= NBD_CMD_FLAG_DF
;
2135 } else if (request
->type
== NBD_CMD_WRITE_ZEROES
) {
2136 valid_flags
|= NBD_CMD_FLAG_NO_HOLE
;
2137 } else if (request
->type
== NBD_CMD_BLOCK_STATUS
) {
2138 valid_flags
|= NBD_CMD_FLAG_REQ_ONE
;
2140 if (request
->flags
& ~valid_flags
) {
2141 error_setg(errp
, "unsupported flags for command %s (got 0x%x)",
2142 nbd_cmd_lookup(request
->type
), request
->flags
);
2149 /* Send simple reply without a payload, or a structured error
2150 * @error_msg is ignored if @ret >= 0
2151 * Returns 0 if connection is still live, -errno on failure to talk to client
2153 static coroutine_fn
int nbd_send_generic_reply(NBDClient
*client
,
2156 const char *error_msg
,
2159 if (client
->structured_reply
&& ret
< 0) {
2160 return nbd_co_send_structured_error(client
, handle
, -ret
, error_msg
,
2163 return nbd_co_send_simple_reply(client
, handle
, ret
< 0 ? -ret
: 0,
2168 /* Handle NBD_CMD_READ request.
2169 * Return -errno if sending fails. Other errors are reported directly to the
2170 * client as an error reply. */
2171 static coroutine_fn
int nbd_do_cmd_read(NBDClient
*client
, NBDRequest
*request
,
2172 uint8_t *data
, Error
**errp
)
2175 NBDExport
*exp
= client
->exp
;
2177 assert(request
->type
== NBD_CMD_READ
|| request
->type
== NBD_CMD_CACHE
);
2179 /* XXX: NBD Protocol only documents use of FUA with WRITE */
2180 if (request
->flags
& NBD_CMD_FLAG_FUA
) {
2181 ret
= blk_co_flush(exp
->blk
);
2183 return nbd_send_generic_reply(client
, request
->handle
, ret
,
2184 "flush failed", errp
);
2188 if (client
->structured_reply
&& !(request
->flags
& NBD_CMD_FLAG_DF
) &&
2189 request
->len
&& request
->type
!= NBD_CMD_CACHE
)
2191 return nbd_co_send_sparse_read(client
, request
->handle
, request
->from
,
2192 data
, request
->len
, errp
);
2195 ret
= blk_pread(exp
->blk
, request
->from
+ exp
->dev_offset
, data
,
2197 if (ret
< 0 || request
->type
== NBD_CMD_CACHE
) {
2198 return nbd_send_generic_reply(client
, request
->handle
, ret
,
2199 "reading from file failed", errp
);
2202 if (client
->structured_reply
) {
2204 return nbd_co_send_structured_read(client
, request
->handle
,
2205 request
->from
, data
,
2206 request
->len
, true, errp
);
2208 return nbd_co_send_structured_done(client
, request
->handle
, errp
);
2211 return nbd_co_send_simple_reply(client
, request
->handle
, 0,
2212 data
, request
->len
, errp
);
2216 /* Handle NBD request.
2217 * Return -errno if sending fails. Other errors are reported directly to the
2218 * client as an error reply. */
2219 static coroutine_fn
int nbd_handle_request(NBDClient
*client
,
2220 NBDRequest
*request
,
2221 uint8_t *data
, Error
**errp
)
2225 NBDExport
*exp
= client
->exp
;
2228 switch (request
->type
) {
2231 return nbd_do_cmd_read(client
, request
, data
, errp
);
2235 if (request
->flags
& NBD_CMD_FLAG_FUA
) {
2236 flags
|= BDRV_REQ_FUA
;
2238 ret
= blk_pwrite(exp
->blk
, request
->from
+ exp
->dev_offset
,
2239 data
, request
->len
, flags
);
2240 return nbd_send_generic_reply(client
, request
->handle
, ret
,
2241 "writing to file failed", errp
);
2243 case NBD_CMD_WRITE_ZEROES
:
2245 if (request
->flags
& NBD_CMD_FLAG_FUA
) {
2246 flags
|= BDRV_REQ_FUA
;
2248 if (!(request
->flags
& NBD_CMD_FLAG_NO_HOLE
)) {
2249 flags
|= BDRV_REQ_MAY_UNMAP
;
2251 ret
= blk_pwrite_zeroes(exp
->blk
, request
->from
+ exp
->dev_offset
,
2252 request
->len
, flags
);
2253 return nbd_send_generic_reply(client
, request
->handle
, ret
,
2254 "writing to file failed", errp
);
2257 /* unreachable, thanks to special case in nbd_co_receive_request() */
2261 ret
= blk_co_flush(exp
->blk
);
2262 return nbd_send_generic_reply(client
, request
->handle
, ret
,
2263 "flush failed", errp
);
2266 ret
= blk_co_pdiscard(exp
->blk
, request
->from
+ exp
->dev_offset
,
2268 if (ret
== 0 && request
->flags
& NBD_CMD_FLAG_FUA
) {
2269 ret
= blk_co_flush(exp
->blk
);
2271 return nbd_send_generic_reply(client
, request
->handle
, ret
,
2272 "discard failed", errp
);
2274 case NBD_CMD_BLOCK_STATUS
:
2275 if (!request
->len
) {
2276 return nbd_send_generic_reply(client
, request
->handle
, -EINVAL
,
2277 "need non-zero length", errp
);
2279 if (client
->export_meta
.valid
&&
2280 (client
->export_meta
.base_allocation
||
2281 client
->export_meta
.bitmap
))
2283 bool dont_fragment
= request
->flags
& NBD_CMD_FLAG_REQ_ONE
;
2285 if (client
->export_meta
.base_allocation
) {
2286 ret
= nbd_co_send_block_status(client
, request
->handle
,
2287 blk_bs(exp
->blk
), request
->from
,
2288 request
->len
, dont_fragment
,
2289 !client
->export_meta
.bitmap
,
2290 NBD_META_ID_BASE_ALLOCATION
,
2297 if (client
->export_meta
.bitmap
) {
2298 ret
= nbd_co_send_bitmap(client
, request
->handle
,
2299 client
->exp
->export_bitmap
,
2300 request
->from
, request
->len
,
2302 true, NBD_META_ID_DIRTY_BITMAP
, errp
);
2310 return nbd_send_generic_reply(client
, request
->handle
, -EINVAL
,
2311 "CMD_BLOCK_STATUS not negotiated",
2316 msg
= g_strdup_printf("invalid request type (%" PRIu32
") received",
2318 ret
= nbd_send_generic_reply(client
, request
->handle
, -EINVAL
, msg
,
2325 /* Owns a reference to the NBDClient passed as opaque. */
2326 static coroutine_fn
void nbd_trip(void *opaque
)
2328 NBDClient
*client
= opaque
;
2329 NBDRequestData
*req
;
2330 NBDRequest request
= { 0 }; /* GCC thinks it can be used uninitialized */
2332 Error
*local_err
= NULL
;
2335 if (client
->closing
) {
2336 nbd_client_put(client
);
2340 req
= nbd_request_get(client
);
2341 ret
= nbd_co_receive_request(req
, &request
, &local_err
);
2342 client
->recv_coroutine
= NULL
;
2344 if (client
->closing
) {
2346 * The client may be closed when we are blocked in
2347 * nbd_co_receive_request()
2352 nbd_client_receive_next_request(client
);
2358 /* It wans't -EIO, so, according to nbd_co_receive_request()
2359 * semantics, we should return the error to the client. */
2360 Error
*export_err
= local_err
;
2363 ret
= nbd_send_generic_reply(client
, request
.handle
, -EINVAL
,
2364 error_get_pretty(export_err
), &local_err
);
2365 error_free(export_err
);
2367 ret
= nbd_handle_request(client
, &request
, req
->data
, &local_err
);
2370 error_prepend(&local_err
, "Failed to send reply: ");
2374 /* We must disconnect after NBD_CMD_WRITE if we did not
2377 if (!req
->complete
) {
2378 error_setg(&local_err
, "Request handling failed in intermediate state");
2383 nbd_request_put(req
);
2384 nbd_client_put(client
);
2389 error_reportf_err(local_err
, "Disconnect client, due to: ");
2391 nbd_request_put(req
);
2392 client_close(client
, true);
2393 nbd_client_put(client
);
2396 static void nbd_client_receive_next_request(NBDClient
*client
)
2398 if (!client
->recv_coroutine
&& client
->nb_requests
< MAX_NBD_REQUESTS
) {
2399 nbd_client_get(client
);
2400 client
->recv_coroutine
= qemu_coroutine_create(nbd_trip
, client
);
2401 aio_co_schedule(client
->exp
->ctx
, client
->recv_coroutine
);
2405 static coroutine_fn
void nbd_co_client_start(void *opaque
)
2407 NBDClient
*client
= opaque
;
2408 Error
*local_err
= NULL
;
2410 qemu_co_mutex_init(&client
->send_lock
);
2412 if (nbd_negotiate(client
, &local_err
)) {
2414 error_report_err(local_err
);
2416 client_close(client
, false);
2420 nbd_client_receive_next_request(client
);
2424 * Create a new client listener using the given channel @sioc.
2425 * Begin servicing it in a coroutine. When the connection closes, call
2426 * @close_fn with an indication of whether the client completed negotiation.
2428 void nbd_client_new(QIOChannelSocket
*sioc
,
2429 QCryptoTLSCreds
*tlscreds
,
2430 const char *tlsauthz
,
2431 void (*close_fn
)(NBDClient
*, bool))
2436 client
= g_new0(NBDClient
, 1);
2437 client
->refcount
= 1;
2438 client
->tlscreds
= tlscreds
;
2440 object_ref(OBJECT(client
->tlscreds
));
2442 client
->tlsauthz
= g_strdup(tlsauthz
);
2443 client
->sioc
= sioc
;
2444 object_ref(OBJECT(client
->sioc
));
2445 client
->ioc
= QIO_CHANNEL(sioc
);
2446 object_ref(OBJECT(client
->ioc
));
2447 client
->close_fn
= close_fn
;
2449 co
= qemu_coroutine_create(nbd_co_client_start
, client
);
2450 qemu_coroutine_enter(co
);