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"
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"
28 #include "nbd-internal.h"
29 #include "qemu/units.h"
30 #include "qemu/memalign.h"
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
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.
43 #define NBD_MAX_BLOCK_STATUS_EXTENTS (1 * MiB / 8)
45 static int system_errno_to_nbd_errno(int err
)
66 #if ENOTSUP != EOPNOTSUPP
78 /* Definitions for opaque data types */
80 typedef struct NBDRequestData NBDRequestData
;
82 struct NBDRequestData
{
95 QTAILQ_HEAD(, NBDClient
) clients
;
96 QTAILQ_ENTRY(NBDExport
) next
;
98 BlockBackend
*eject_notifier_blk
;
99 Notifier eject_notifier
;
101 bool allocation_depth
;
102 BdrvDirtyBitmap
**export_bitmaps
;
103 size_t nr_export_bitmaps
;
106 static QTAILQ_HEAD(, NBDExport
) exports
= QTAILQ_HEAD_INITIALIZER(exports
);
109 * NBDMetaContexts represents a list of meta contexts in use,
110 * as selected by NBD_OPT_SET_META_CONTEXT. Also used for
111 * NBD_OPT_LIST_META_CONTEXT.
113 struct NBDMetaContexts
{
114 const NBDExport
*exp
; /* associated export */
115 size_t count
; /* number of negotiated contexts */
116 bool base_allocation
; /* export base:allocation context (block status) */
117 bool allocation_depth
; /* export qemu:allocation-depth */
119 * export qemu:dirty-bitmap:<export bitmap name>,
120 * sized by exp->nr_export_bitmaps
126 void (*close_fn
)(NBDClient
*client
, bool negotiated
);
129 QCryptoTLSCreds
*tlscreds
;
131 QIOChannelSocket
*sioc
; /* The underlying data channel */
132 QIOChannel
*ioc
; /* The current I/O channel which may differ (eg TLS) */
134 Coroutine
*recv_coroutine
;
137 Coroutine
*send_coroutine
;
142 QTAILQ_ENTRY(NBDClient
) next
;
146 uint32_t check_align
; /* If non-zero, check for aligned client requests */
149 NBDMetaContexts contexts
; /* Negotiated meta contexts */
151 uint32_t opt
; /* Current option being negotiated */
152 uint32_t optlen
; /* remaining length of data in ioc for the option being
156 static void nbd_client_receive_next_request(NBDClient
*client
);
158 /* Basic flow for negotiation
185 static inline void set_be_option_rep(NBDOptionReply
*rep
, uint32_t option
,
186 uint32_t type
, uint32_t length
)
188 stq_be_p(&rep
->magic
, NBD_REP_MAGIC
);
189 stl_be_p(&rep
->option
, option
);
190 stl_be_p(&rep
->type
, type
);
191 stl_be_p(&rep
->length
, length
);
194 /* Send a reply header, including length, but no payload.
195 * Return -errno on error, 0 on success. */
196 static int nbd_negotiate_send_rep_len(NBDClient
*client
, uint32_t type
,
197 uint32_t len
, Error
**errp
)
201 trace_nbd_negotiate_send_rep_len(client
->opt
, nbd_opt_lookup(client
->opt
),
202 type
, nbd_rep_lookup(type
), len
);
204 assert(len
< NBD_MAX_BUFFER_SIZE
);
206 set_be_option_rep(&rep
, client
->opt
, type
, len
);
207 return nbd_write(client
->ioc
, &rep
, sizeof(rep
), errp
);
210 /* Send a reply header with default 0 length.
211 * Return -errno on error, 0 on success. */
212 static int nbd_negotiate_send_rep(NBDClient
*client
, uint32_t type
,
215 return nbd_negotiate_send_rep_len(client
, type
, 0, errp
);
218 /* Send an error reply.
219 * Return -errno on error, 0 on success. */
220 static int G_GNUC_PRINTF(4, 0)
221 nbd_negotiate_send_rep_verr(NBDClient
*client
, uint32_t type
,
222 Error
**errp
, const char *fmt
, va_list va
)
225 g_autofree
char *msg
= NULL
;
229 msg
= g_strdup_vprintf(fmt
, va
);
231 assert(len
< NBD_MAX_STRING_SIZE
);
232 trace_nbd_negotiate_send_rep_err(msg
);
233 ret
= nbd_negotiate_send_rep_len(client
, type
, len
, errp
);
237 if (nbd_write(client
->ioc
, msg
, len
, errp
) < 0) {
238 error_prepend(errp
, "write failed (error message): ");
246 * Return a malloc'd copy of @name suitable for use in an error reply.
249 nbd_sanitize_name(const char *name
)
251 if (strnlen(name
, 80) < 80) {
252 return g_strdup(name
);
254 /* XXX Should we also try to sanitize any control characters? */
255 return g_strdup_printf("%.80s...", name
);
258 /* Send an error reply.
259 * Return -errno on error, 0 on success. */
260 static int G_GNUC_PRINTF(4, 5)
261 nbd_negotiate_send_rep_err(NBDClient
*client
, uint32_t type
,
262 Error
**errp
, const char *fmt
, ...)
268 ret
= nbd_negotiate_send_rep_verr(client
, type
, errp
, fmt
, va
);
273 /* Drop remainder of the current option, and send a reply with the
274 * given error type and message. Return -errno on read or write
275 * failure; or 0 if connection is still live. */
276 static int G_GNUC_PRINTF(4, 0)
277 nbd_opt_vdrop(NBDClient
*client
, uint32_t type
, Error
**errp
,
278 const char *fmt
, va_list va
)
280 int ret
= nbd_drop(client
->ioc
, client
->optlen
, errp
);
284 ret
= nbd_negotiate_send_rep_verr(client
, type
, errp
, fmt
, va
);
289 static int G_GNUC_PRINTF(4, 5)
290 nbd_opt_drop(NBDClient
*client
, uint32_t type
, Error
**errp
,
291 const char *fmt
, ...)
297 ret
= nbd_opt_vdrop(client
, type
, errp
, fmt
, va
);
303 static int G_GNUC_PRINTF(3, 4)
304 nbd_opt_invalid(NBDClient
*client
, Error
**errp
, const char *fmt
, ...)
310 ret
= nbd_opt_vdrop(client
, NBD_REP_ERR_INVALID
, errp
, fmt
, va
);
316 /* Read size bytes from the unparsed payload of the current option.
317 * If @check_nul, require that no NUL bytes appear in buffer.
318 * Return -errno on I/O error, 0 if option was completely handled by
319 * sending a reply about inconsistent lengths, or 1 on success. */
320 static int nbd_opt_read(NBDClient
*client
, void *buffer
, size_t size
,
321 bool check_nul
, Error
**errp
)
323 if (size
> client
->optlen
) {
324 return nbd_opt_invalid(client
, errp
,
325 "Inconsistent lengths in option %s",
326 nbd_opt_lookup(client
->opt
));
328 client
->optlen
-= size
;
329 if (qio_channel_read_all(client
->ioc
, buffer
, size
, errp
) < 0) {
333 if (check_nul
&& strnlen(buffer
, size
) != size
) {
334 return nbd_opt_invalid(client
, errp
,
335 "Unexpected embedded NUL in option %s",
336 nbd_opt_lookup(client
->opt
));
341 /* Drop size bytes from the unparsed payload of the current option.
342 * Return -errno on I/O error, 0 if option was completely handled by
343 * sending a reply about inconsistent lengths, or 1 on success. */
344 static int nbd_opt_skip(NBDClient
*client
, size_t size
, Error
**errp
)
346 if (size
> client
->optlen
) {
347 return nbd_opt_invalid(client
, errp
,
348 "Inconsistent lengths in option %s",
349 nbd_opt_lookup(client
->opt
));
351 client
->optlen
-= size
;
352 return nbd_drop(client
->ioc
, size
, errp
) < 0 ? -EIO
: 1;
357 * Read a string with the format:
358 * uint32_t len (<= NBD_MAX_STRING_SIZE)
359 * len bytes string (not 0-terminated)
361 * On success, @name will be allocated.
362 * If @length is non-null, it will be set to the actual string length.
364 * Return -errno on I/O error, 0 if option was completely handled by
365 * sending a reply about inconsistent lengths, or 1 on success.
367 static int nbd_opt_read_name(NBDClient
*client
, char **name
, uint32_t *length
,
372 g_autofree
char *local_name
= NULL
;
375 ret
= nbd_opt_read(client
, &len
, sizeof(len
), false, errp
);
379 len
= cpu_to_be32(len
);
381 if (len
> NBD_MAX_STRING_SIZE
) {
382 return nbd_opt_invalid(client
, errp
,
383 "Invalid name length: %" PRIu32
, len
);
386 local_name
= g_malloc(len
+ 1);
387 ret
= nbd_opt_read(client
, local_name
, len
, true, errp
);
391 local_name
[len
] = '\0';
396 *name
= g_steal_pointer(&local_name
);
401 /* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload.
402 * Return -errno on error, 0 on success. */
403 static int nbd_negotiate_send_rep_list(NBDClient
*client
, NBDExport
*exp
,
407 size_t name_len
, desc_len
;
409 const char *name
= exp
->name
? exp
->name
: "";
410 const char *desc
= exp
->description
? exp
->description
: "";
411 QIOChannel
*ioc
= client
->ioc
;
414 trace_nbd_negotiate_send_rep_list(name
, desc
);
415 name_len
= strlen(name
);
416 desc_len
= strlen(desc
);
417 assert(name_len
<= NBD_MAX_STRING_SIZE
&& desc_len
<= NBD_MAX_STRING_SIZE
);
418 len
= name_len
+ desc_len
+ sizeof(len
);
419 ret
= nbd_negotiate_send_rep_len(client
, NBD_REP_SERVER
, len
, errp
);
424 len
= cpu_to_be32(name_len
);
425 if (nbd_write(ioc
, &len
, sizeof(len
), errp
) < 0) {
426 error_prepend(errp
, "write failed (name length): ");
430 if (nbd_write(ioc
, name
, name_len
, errp
) < 0) {
431 error_prepend(errp
, "write failed (name buffer): ");
435 if (nbd_write(ioc
, desc
, desc_len
, errp
) < 0) {
436 error_prepend(errp
, "write failed (description buffer): ");
443 /* Process the NBD_OPT_LIST command, with a potential series of replies.
444 * Return -errno on error, 0 on success. */
445 static int nbd_negotiate_handle_list(NBDClient
*client
, Error
**errp
)
448 assert(client
->opt
== NBD_OPT_LIST
);
450 /* For each export, send a NBD_REP_SERVER reply. */
451 QTAILQ_FOREACH(exp
, &exports
, next
) {
452 if (nbd_negotiate_send_rep_list(client
, exp
, errp
)) {
456 /* Finish with a NBD_REP_ACK. */
457 return nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
);
460 static void nbd_check_meta_export(NBDClient
*client
, NBDExport
*exp
)
462 if (exp
!= client
->contexts
.exp
) {
463 client
->contexts
.count
= 0;
467 /* Send a reply to NBD_OPT_EXPORT_NAME.
468 * Return -errno on error, 0 on success. */
469 static int nbd_negotiate_handle_export_name(NBDClient
*client
, bool no_zeroes
,
473 g_autofree
char *name
= NULL
;
474 char buf
[NBD_REPLY_EXPORT_NAME_SIZE
] = "";
480 [20 .. xx] export name (length bytes)
483 [ 8 .. 9] export flags
484 [10 .. 133] reserved (0) [unless no_zeroes]
486 trace_nbd_negotiate_handle_export_name();
487 if (client
->mode
>= NBD_MODE_EXTENDED
) {
488 error_setg(errp
, "Extended headers already negotiated");
491 if (client
->optlen
> NBD_MAX_STRING_SIZE
) {
492 error_setg(errp
, "Bad length received");
495 name
= g_malloc(client
->optlen
+ 1);
496 if (nbd_read(client
->ioc
, name
, client
->optlen
, "export name", errp
) < 0) {
499 name
[client
->optlen
] = '\0';
502 trace_nbd_negotiate_handle_export_name_request(name
);
504 client
->exp
= nbd_export_find(name
);
506 error_setg(errp
, "export not found");
509 nbd_check_meta_export(client
, client
->exp
);
511 myflags
= client
->exp
->nbdflags
;
512 if (client
->mode
>= NBD_MODE_STRUCTURED
) {
513 myflags
|= NBD_FLAG_SEND_DF
;
515 if (client
->mode
>= NBD_MODE_EXTENDED
&& client
->contexts
.count
) {
516 myflags
|= NBD_FLAG_BLOCK_STAT_PAYLOAD
;
518 trace_nbd_negotiate_new_style_size_flags(client
->exp
->size
, myflags
);
519 stq_be_p(buf
, client
->exp
->size
);
520 stw_be_p(buf
+ 8, myflags
);
521 len
= no_zeroes
? 10 : sizeof(buf
);
522 ret
= nbd_write(client
->ioc
, buf
, len
, errp
);
524 error_prepend(errp
, "write failed: ");
528 QTAILQ_INSERT_TAIL(&client
->exp
->clients
, client
, next
);
529 blk_exp_ref(&client
->exp
->common
);
534 /* Send a single NBD_REP_INFO, with a buffer @buf of @length bytes.
535 * The buffer does NOT include the info type prefix.
536 * Return -errno on error, 0 if ready to send more. */
537 static int nbd_negotiate_send_info(NBDClient
*client
,
538 uint16_t info
, uint32_t length
, void *buf
,
543 trace_nbd_negotiate_send_info(info
, nbd_info_lookup(info
), length
);
544 rc
= nbd_negotiate_send_rep_len(client
, NBD_REP_INFO
,
545 sizeof(info
) + length
, errp
);
549 info
= cpu_to_be16(info
);
550 if (nbd_write(client
->ioc
, &info
, sizeof(info
), errp
) < 0) {
553 if (nbd_write(client
->ioc
, buf
, length
, errp
) < 0) {
559 /* nbd_reject_length: Handle any unexpected payload.
560 * @fatal requests that we quit talking to the client, even if we are able
561 * to successfully send an error reply.
563 * -errno transmission error occurred or @fatal was requested, errp is set
564 * 0 error message successfully sent to client, errp is not set
566 static int nbd_reject_length(NBDClient
*client
, bool fatal
, Error
**errp
)
570 assert(client
->optlen
);
571 ret
= nbd_opt_invalid(client
, errp
, "option '%s' has unexpected length",
572 nbd_opt_lookup(client
->opt
));
574 error_setg(errp
, "option '%s' has unexpected length",
575 nbd_opt_lookup(client
->opt
));
581 /* Handle NBD_OPT_INFO and NBD_OPT_GO.
582 * Return -errno on error, 0 if ready for next option, and 1 to move
583 * into transmission phase. */
584 static int nbd_negotiate_handle_info(NBDClient
*client
, Error
**errp
)
587 g_autofree
char *name
= NULL
;
591 uint32_t namelen
= 0;
592 bool sendname
= false;
593 bool blocksize
= false;
595 char buf
[sizeof(uint64_t) + sizeof(uint16_t)];
596 uint32_t check_align
= 0;
600 4 bytes: L, name length (can be 0)
602 2 bytes: N, number of requests (can be 0)
603 N * 2 bytes: N requests
605 rc
= nbd_opt_read_name(client
, &name
, &namelen
, errp
);
609 trace_nbd_negotiate_handle_export_name_request(name
);
611 rc
= nbd_opt_read(client
, &requests
, sizeof(requests
), false, errp
);
615 requests
= be16_to_cpu(requests
);
616 trace_nbd_negotiate_handle_info_requests(requests
);
618 rc
= nbd_opt_read(client
, &request
, sizeof(request
), false, errp
);
622 request
= be16_to_cpu(request
);
623 trace_nbd_negotiate_handle_info_request(request
,
624 nbd_info_lookup(request
));
625 /* We care about NBD_INFO_NAME and NBD_INFO_BLOCK_SIZE;
626 * everything else is either a request we don't know or
627 * something we send regardless of request */
632 case NBD_INFO_BLOCK_SIZE
:
637 if (client
->optlen
) {
638 return nbd_reject_length(client
, false, errp
);
641 exp
= nbd_export_find(name
);
643 g_autofree
char *sane_name
= nbd_sanitize_name(name
);
645 return nbd_negotiate_send_rep_err(client
, NBD_REP_ERR_UNKNOWN
,
646 errp
, "export '%s' not present",
649 if (client
->opt
== NBD_OPT_GO
) {
650 nbd_check_meta_export(client
, exp
);
653 /* Don't bother sending NBD_INFO_NAME unless client requested it */
655 rc
= nbd_negotiate_send_info(client
, NBD_INFO_NAME
, namelen
, name
,
662 /* Send NBD_INFO_DESCRIPTION only if available, regardless of
664 if (exp
->description
) {
665 size_t len
= strlen(exp
->description
);
667 assert(len
<= NBD_MAX_STRING_SIZE
);
668 rc
= nbd_negotiate_send_info(client
, NBD_INFO_DESCRIPTION
,
669 len
, exp
->description
, errp
);
675 /* Send NBD_INFO_BLOCK_SIZE always, but tweak the minimum size
676 * according to whether the client requested it, and according to
677 * whether this is OPT_INFO or OPT_GO. */
678 /* minimum - 1 for back-compat, or actual if client will obey it. */
679 if (client
->opt
== NBD_OPT_INFO
|| blocksize
) {
680 check_align
= sizes
[0] = blk_get_request_alignment(exp
->common
.blk
);
684 assert(sizes
[0] <= NBD_MAX_BUFFER_SIZE
);
685 /* preferred - Hard-code to 4096 for now.
686 * TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */
687 sizes
[1] = MAX(4096, sizes
[0]);
688 /* maximum - At most 32M, but smaller as appropriate. */
689 sizes
[2] = MIN(blk_get_max_transfer(exp
->common
.blk
), NBD_MAX_BUFFER_SIZE
);
690 trace_nbd_negotiate_handle_info_block_size(sizes
[0], sizes
[1], sizes
[2]);
691 sizes
[0] = cpu_to_be32(sizes
[0]);
692 sizes
[1] = cpu_to_be32(sizes
[1]);
693 sizes
[2] = cpu_to_be32(sizes
[2]);
694 rc
= nbd_negotiate_send_info(client
, NBD_INFO_BLOCK_SIZE
,
695 sizeof(sizes
), sizes
, errp
);
700 /* Send NBD_INFO_EXPORT always */
701 myflags
= exp
->nbdflags
;
702 if (client
->mode
>= NBD_MODE_STRUCTURED
) {
703 myflags
|= NBD_FLAG_SEND_DF
;
705 if (client
->mode
>= NBD_MODE_EXTENDED
&&
706 (client
->contexts
.count
|| client
->opt
== NBD_OPT_INFO
)) {
707 myflags
|= NBD_FLAG_BLOCK_STAT_PAYLOAD
;
709 trace_nbd_negotiate_new_style_size_flags(exp
->size
, myflags
);
710 stq_be_p(buf
, exp
->size
);
711 stw_be_p(buf
+ 8, myflags
);
712 rc
= nbd_negotiate_send_info(client
, NBD_INFO_EXPORT
,
713 sizeof(buf
), buf
, errp
);
719 * If the client is just asking for NBD_OPT_INFO, but forgot to
720 * request block sizes in a situation that would impact
721 * performance, then return an error. But for NBD_OPT_GO, we
722 * tolerate all clients, regardless of alignments.
724 if (client
->opt
== NBD_OPT_INFO
&& !blocksize
&&
725 blk_get_request_alignment(exp
->common
.blk
) > 1) {
726 return nbd_negotiate_send_rep_err(client
,
727 NBD_REP_ERR_BLOCK_SIZE_REQD
,
729 "request NBD_INFO_BLOCK_SIZE to "
734 rc
= nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
);
739 if (client
->opt
== NBD_OPT_GO
) {
741 client
->check_align
= check_align
;
742 QTAILQ_INSERT_TAIL(&client
->exp
->clients
, client
, next
);
743 blk_exp_ref(&client
->exp
->common
);
750 /* Handle NBD_OPT_STARTTLS. Return NULL to drop connection, or else the
751 * new channel for all further (now-encrypted) communication. */
752 static QIOChannel
*nbd_negotiate_handle_starttls(NBDClient
*client
,
757 struct NBDTLSHandshakeData data
= { 0 };
759 assert(client
->opt
== NBD_OPT_STARTTLS
);
761 trace_nbd_negotiate_handle_starttls();
764 if (nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
) < 0) {
768 tioc
= qio_channel_tls_new_server(ioc
,
776 qio_channel_set_name(QIO_CHANNEL(tioc
), "nbd-server-tls");
777 trace_nbd_negotiate_handle_starttls_handshake();
778 data
.loop
= g_main_loop_new(g_main_context_default(), FALSE
);
779 qio_channel_tls_handshake(tioc
,
785 if (!data
.complete
) {
786 g_main_loop_run(data
.loop
);
788 g_main_loop_unref(data
.loop
);
790 object_unref(OBJECT(tioc
));
791 error_propagate(errp
, data
.error
);
795 return QIO_CHANNEL(tioc
);
798 /* nbd_negotiate_send_meta_context
800 * Send one chunk of reply to NBD_OPT_{LIST,SET}_META_CONTEXT
802 * For NBD_OPT_LIST_META_CONTEXT @context_id is ignored, 0 is used instead.
804 static int nbd_negotiate_send_meta_context(NBDClient
*client
,
809 NBDOptionReplyMetaContext opt
;
810 struct iovec iov
[] = {
811 {.iov_base
= &opt
, .iov_len
= sizeof(opt
)},
812 {.iov_base
= (void *)context
, .iov_len
= strlen(context
)}
815 assert(iov
[1].iov_len
<= NBD_MAX_STRING_SIZE
);
816 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
) {
820 trace_nbd_negotiate_meta_query_reply(context
, context_id
);
821 set_be_option_rep(&opt
.h
, client
->opt
, NBD_REP_META_CONTEXT
,
822 sizeof(opt
) - sizeof(opt
.h
) + iov
[1].iov_len
);
823 stl_be_p(&opt
.context_id
, context_id
);
825 return qio_channel_writev_all(client
->ioc
, iov
, 2, errp
) < 0 ? -EIO
: 0;
829 * Return true if @query matches @pattern, or if @query is empty when
830 * the @client is performing _LIST_.
832 static bool nbd_meta_empty_or_pattern(NBDClient
*client
, const char *pattern
,
836 trace_nbd_negotiate_meta_query_parse("empty");
837 return client
->opt
== NBD_OPT_LIST_META_CONTEXT
;
839 if (strcmp(query
, pattern
) == 0) {
840 trace_nbd_negotiate_meta_query_parse(pattern
);
843 trace_nbd_negotiate_meta_query_skip("pattern not matched");
848 * Return true and adjust @str in place if it begins with @prefix.
850 static bool nbd_strshift(const char **str
, const char *prefix
)
852 size_t len
= strlen(prefix
);
854 if (strncmp(*str
, prefix
, len
) == 0) {
861 /* nbd_meta_base_query
863 * Handle queries to 'base' namespace. For now, only the base:allocation
864 * context is available. Return true if @query has been handled.
866 static bool nbd_meta_base_query(NBDClient
*client
, NBDMetaContexts
*meta
,
869 if (!nbd_strshift(&query
, "base:")) {
872 trace_nbd_negotiate_meta_query_parse("base:");
874 if (nbd_meta_empty_or_pattern(client
, "allocation", query
)) {
875 meta
->base_allocation
= true;
880 /* nbd_meta_qemu_query
882 * Handle queries to 'qemu' namespace. For now, only the qemu:dirty-bitmap:
883 * and qemu:allocation-depth contexts are available. Return true if @query
886 static bool nbd_meta_qemu_query(NBDClient
*client
, NBDMetaContexts
*meta
,
891 if (!nbd_strshift(&query
, "qemu:")) {
894 trace_nbd_negotiate_meta_query_parse("qemu:");
897 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
) {
898 meta
->allocation_depth
= meta
->exp
->allocation_depth
;
899 if (meta
->exp
->nr_export_bitmaps
) {
900 memset(meta
->bitmaps
, 1, meta
->exp
->nr_export_bitmaps
);
903 trace_nbd_negotiate_meta_query_parse("empty");
907 if (strcmp(query
, "allocation-depth") == 0) {
908 trace_nbd_negotiate_meta_query_parse("allocation-depth");
909 meta
->allocation_depth
= meta
->exp
->allocation_depth
;
913 if (nbd_strshift(&query
, "dirty-bitmap:")) {
914 trace_nbd_negotiate_meta_query_parse("dirty-bitmap:");
916 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
&&
917 meta
->exp
->nr_export_bitmaps
) {
918 memset(meta
->bitmaps
, 1, meta
->exp
->nr_export_bitmaps
);
920 trace_nbd_negotiate_meta_query_parse("empty");
924 for (i
= 0; i
< meta
->exp
->nr_export_bitmaps
; i
++) {
927 bm_name
= bdrv_dirty_bitmap_name(meta
->exp
->export_bitmaps
[i
]);
928 if (strcmp(bm_name
, query
) == 0) {
929 meta
->bitmaps
[i
] = true;
930 trace_nbd_negotiate_meta_query_parse(query
);
934 trace_nbd_negotiate_meta_query_skip("no dirty-bitmap match");
938 trace_nbd_negotiate_meta_query_skip("unknown qemu context");
942 /* nbd_negotiate_meta_query
944 * Parse namespace name and call corresponding function to parse body of the
947 * The only supported namespaces are 'base' and 'qemu'.
949 * Return -errno on I/O error, 0 if option was completely handled by
950 * sending a reply about inconsistent lengths, or 1 on success. */
951 static int nbd_negotiate_meta_query(NBDClient
*client
,
952 NBDMetaContexts
*meta
, Error
**errp
)
955 g_autofree
char *query
= NULL
;
958 ret
= nbd_opt_read(client
, &len
, sizeof(len
), false, errp
);
962 len
= cpu_to_be32(len
);
964 if (len
> NBD_MAX_STRING_SIZE
) {
965 trace_nbd_negotiate_meta_query_skip("length too long");
966 return nbd_opt_skip(client
, len
, errp
);
969 query
= g_malloc(len
+ 1);
970 ret
= nbd_opt_read(client
, query
, len
, true, errp
);
976 if (nbd_meta_base_query(client
, meta
, query
)) {
979 if (nbd_meta_qemu_query(client
, meta
, query
)) {
983 trace_nbd_negotiate_meta_query_skip("unknown namespace");
987 /* nbd_negotiate_meta_queries
988 * Handle NBD_OPT_LIST_META_CONTEXT and NBD_OPT_SET_META_CONTEXT
990 * Return -errno on I/O error, or 0 if option was completely handled. */
991 static int nbd_negotiate_meta_queries(NBDClient
*client
, Error
**errp
)
994 g_autofree
char *export_name
= NULL
;
995 /* Mark unused to work around https://bugs.llvm.org/show_bug.cgi?id=3888 */
996 g_autofree G_GNUC_UNUSED
bool *bitmaps
= NULL
;
997 NBDMetaContexts local_meta
= {0};
998 NBDMetaContexts
*meta
;
1003 if (client
->opt
== NBD_OPT_SET_META_CONTEXT
&&
1004 client
->mode
< NBD_MODE_STRUCTURED
) {
1005 return nbd_opt_invalid(client
, errp
,
1006 "request option '%s' when structured reply "
1007 "is not negotiated",
1008 nbd_opt_lookup(client
->opt
));
1011 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
) {
1012 /* Only change the caller's meta on SET. */
1015 meta
= &client
->contexts
;
1018 g_free(meta
->bitmaps
);
1019 memset(meta
, 0, sizeof(*meta
));
1021 ret
= nbd_opt_read_name(client
, &export_name
, NULL
, errp
);
1026 meta
->exp
= nbd_export_find(export_name
);
1027 if (meta
->exp
== NULL
) {
1028 g_autofree
char *sane_name
= nbd_sanitize_name(export_name
);
1030 return nbd_opt_drop(client
, NBD_REP_ERR_UNKNOWN
, errp
,
1031 "export '%s' not present", sane_name
);
1033 meta
->bitmaps
= g_new0(bool, meta
->exp
->nr_export_bitmaps
);
1034 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
) {
1035 bitmaps
= meta
->bitmaps
;
1038 ret
= nbd_opt_read(client
, &nb_queries
, sizeof(nb_queries
), false, errp
);
1042 nb_queries
= cpu_to_be32(nb_queries
);
1043 trace_nbd_negotiate_meta_context(nbd_opt_lookup(client
->opt
),
1044 export_name
, nb_queries
);
1046 if (client
->opt
== NBD_OPT_LIST_META_CONTEXT
&& !nb_queries
) {
1047 /* enable all known contexts */
1048 meta
->base_allocation
= true;
1049 meta
->allocation_depth
= meta
->exp
->allocation_depth
;
1050 if (meta
->exp
->nr_export_bitmaps
) {
1051 memset(meta
->bitmaps
, 1, meta
->exp
->nr_export_bitmaps
);
1054 for (i
= 0; i
< nb_queries
; ++i
) {
1055 ret
= nbd_negotiate_meta_query(client
, meta
, errp
);
1062 if (meta
->base_allocation
) {
1063 ret
= nbd_negotiate_send_meta_context(client
, "base:allocation",
1064 NBD_META_ID_BASE_ALLOCATION
,
1072 if (meta
->allocation_depth
) {
1073 ret
= nbd_negotiate_send_meta_context(client
, "qemu:allocation-depth",
1074 NBD_META_ID_ALLOCATION_DEPTH
,
1082 for (i
= 0; i
< meta
->exp
->nr_export_bitmaps
; i
++) {
1083 const char *bm_name
;
1084 g_autofree
char *context
= NULL
;
1086 if (!meta
->bitmaps
[i
]) {
1090 bm_name
= bdrv_dirty_bitmap_name(meta
->exp
->export_bitmaps
[i
]);
1091 context
= g_strdup_printf("qemu:dirty-bitmap:%s", bm_name
);
1093 ret
= nbd_negotiate_send_meta_context(client
, context
,
1094 NBD_META_ID_DIRTY_BITMAP
+ i
,
1102 ret
= nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
);
1104 meta
->count
= count
;
1110 /* nbd_negotiate_options
1111 * Process all NBD_OPT_* client option commands, during fixed newstyle
1114 * -errno on error, errp is set
1115 * 0 on successful negotiation, errp is not set
1116 * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
1119 static int nbd_negotiate_options(NBDClient
*client
, Error
**errp
)
1122 bool fixedNewstyle
= false;
1123 bool no_zeroes
= false;
1126 [ 0 .. 3] client flags
1128 Then we loop until NBD_OPT_EXPORT_NAME or NBD_OPT_GO:
1129 [ 0 .. 7] NBD_OPTS_MAGIC
1130 [ 8 .. 11] NBD option
1131 [12 .. 15] Data length
1134 [ 0 .. 7] NBD_OPTS_MAGIC
1135 [ 8 .. 11] Second NBD option
1136 [12 .. 15] Data length
1140 if (nbd_read32(client
->ioc
, &flags
, "flags", errp
) < 0) {
1143 client
->mode
= NBD_MODE_EXPORT_NAME
;
1144 trace_nbd_negotiate_options_flags(flags
);
1145 if (flags
& NBD_FLAG_C_FIXED_NEWSTYLE
) {
1146 fixedNewstyle
= true;
1147 flags
&= ~NBD_FLAG_C_FIXED_NEWSTYLE
;
1148 client
->mode
= NBD_MODE_SIMPLE
;
1150 if (flags
& NBD_FLAG_C_NO_ZEROES
) {
1152 flags
&= ~NBD_FLAG_C_NO_ZEROES
;
1155 error_setg(errp
, "Unknown client flags 0x%" PRIx32
" received", flags
);
1161 uint32_t option
, length
;
1164 if (nbd_read64(client
->ioc
, &magic
, "opts magic", errp
) < 0) {
1167 trace_nbd_negotiate_options_check_magic(magic
);
1168 if (magic
!= NBD_OPTS_MAGIC
) {
1169 error_setg(errp
, "Bad magic received");
1173 if (nbd_read32(client
->ioc
, &option
, "option", errp
) < 0) {
1176 client
->opt
= option
;
1178 if (nbd_read32(client
->ioc
, &length
, "option length", errp
) < 0) {
1181 assert(!client
->optlen
);
1182 client
->optlen
= length
;
1184 if (length
> NBD_MAX_BUFFER_SIZE
) {
1185 error_setg(errp
, "len (%" PRIu32
") is larger than max len (%u)",
1186 length
, NBD_MAX_BUFFER_SIZE
);
1190 trace_nbd_negotiate_options_check_option(option
,
1191 nbd_opt_lookup(option
));
1192 if (client
->tlscreds
&&
1193 client
->ioc
== (QIOChannel
*)client
->sioc
) {
1195 if (!fixedNewstyle
) {
1196 error_setg(errp
, "Unsupported option 0x%" PRIx32
, option
);
1200 case NBD_OPT_STARTTLS
:
1202 /* Unconditionally drop the connection if the client
1203 * can't start a TLS negotiation correctly */
1204 return nbd_reject_length(client
, true, errp
);
1206 tioc
= nbd_negotiate_handle_starttls(client
, errp
);
1211 object_unref(OBJECT(client
->ioc
));
1215 case NBD_OPT_EXPORT_NAME
:
1216 /* No way to return an error to client, so drop connection */
1217 error_setg(errp
, "Option 0x%x not permitted before TLS",
1222 /* Let the client keep trying, unless they asked to
1223 * quit. Always try to give an error back to the
1224 * client; but when replying to OPT_ABORT, be aware
1225 * that the client may hang up before receiving the
1226 * error, in which case we are fine ignoring the
1227 * resulting EPIPE. */
1228 ret
= nbd_opt_drop(client
, NBD_REP_ERR_TLS_REQD
,
1229 option
== NBD_OPT_ABORT
? NULL
: errp
,
1231 " not permitted before TLS", option
);
1232 if (option
== NBD_OPT_ABORT
) {
1237 } else if (fixedNewstyle
) {
1241 ret
= nbd_reject_length(client
, false, errp
);
1243 ret
= nbd_negotiate_handle_list(client
, errp
);
1248 /* NBD spec says we must try to reply before
1249 * disconnecting, but that we must also tolerate
1250 * guests that don't wait for our reply. */
1251 nbd_negotiate_send_rep(client
, NBD_REP_ACK
, NULL
);
1254 case NBD_OPT_EXPORT_NAME
:
1255 return nbd_negotiate_handle_export_name(client
, no_zeroes
,
1260 ret
= nbd_negotiate_handle_info(client
, errp
);
1262 assert(option
== NBD_OPT_GO
);
1267 case NBD_OPT_STARTTLS
:
1269 ret
= nbd_reject_length(client
, false, errp
);
1270 } else if (client
->tlscreds
) {
1271 ret
= nbd_negotiate_send_rep_err(client
,
1272 NBD_REP_ERR_INVALID
, errp
,
1273 "TLS already enabled");
1275 ret
= nbd_negotiate_send_rep_err(client
,
1276 NBD_REP_ERR_POLICY
, errp
,
1277 "TLS not configured");
1281 case NBD_OPT_STRUCTURED_REPLY
:
1283 ret
= nbd_reject_length(client
, false, errp
);
1284 } else if (client
->mode
>= NBD_MODE_EXTENDED
) {
1285 ret
= nbd_negotiate_send_rep_err(
1286 client
, NBD_REP_ERR_EXT_HEADER_REQD
, errp
,
1287 "extended headers already negotiated");
1288 } else if (client
->mode
>= NBD_MODE_STRUCTURED
) {
1289 ret
= nbd_negotiate_send_rep_err(
1290 client
, NBD_REP_ERR_INVALID
, errp
,
1291 "structured reply already negotiated");
1293 ret
= nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
);
1294 client
->mode
= NBD_MODE_STRUCTURED
;
1298 case NBD_OPT_LIST_META_CONTEXT
:
1299 case NBD_OPT_SET_META_CONTEXT
:
1300 ret
= nbd_negotiate_meta_queries(client
, errp
);
1303 case NBD_OPT_EXTENDED_HEADERS
:
1305 ret
= nbd_reject_length(client
, false, errp
);
1306 } else if (client
->mode
>= NBD_MODE_EXTENDED
) {
1307 ret
= nbd_negotiate_send_rep_err(
1308 client
, NBD_REP_ERR_INVALID
, errp
,
1309 "extended headers already negotiated");
1311 ret
= nbd_negotiate_send_rep(client
, NBD_REP_ACK
, errp
);
1312 client
->mode
= NBD_MODE_EXTENDED
;
1317 ret
= nbd_opt_drop(client
, NBD_REP_ERR_UNSUP
, errp
,
1318 "Unsupported option %" PRIu32
" (%s)",
1319 option
, nbd_opt_lookup(option
));
1324 * If broken new-style we should drop the connection
1325 * for anything except NBD_OPT_EXPORT_NAME
1328 case NBD_OPT_EXPORT_NAME
:
1329 return nbd_negotiate_handle_export_name(client
, no_zeroes
,
1333 error_setg(errp
, "Unsupported option %" PRIu32
" (%s)",
1334 option
, nbd_opt_lookup(option
));
1346 * -errno on error, errp is set
1347 * 0 on successful negotiation, errp is not set
1348 * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
1351 static coroutine_fn
int nbd_negotiate(NBDClient
*client
, Error
**errp
)
1354 char buf
[NBD_OLDSTYLE_NEGOTIATE_SIZE
] = "";
1357 /* Old style negotiation header, no room for options
1358 [ 0 .. 7] passwd ("NBDMAGIC")
1359 [ 8 .. 15] magic (NBD_CLIENT_MAGIC)
1361 [24 .. 27] export flags (zero-extended)
1362 [28 .. 151] reserved (0)
1364 New style negotiation header, client can send options
1365 [ 0 .. 7] passwd ("NBDMAGIC")
1366 [ 8 .. 15] magic (NBD_OPTS_MAGIC)
1367 [16 .. 17] server flags (0)
1368 ....options sent, ending in NBD_OPT_EXPORT_NAME or NBD_OPT_GO....
1371 qio_channel_set_blocking(client
->ioc
, false, NULL
);
1372 qio_channel_set_follow_coroutine_ctx(client
->ioc
, true);
1374 trace_nbd_negotiate_begin();
1375 memcpy(buf
, "NBDMAGIC", 8);
1377 stq_be_p(buf
+ 8, NBD_OPTS_MAGIC
);
1378 stw_be_p(buf
+ 16, NBD_FLAG_FIXED_NEWSTYLE
| NBD_FLAG_NO_ZEROES
);
1380 if (nbd_write(client
->ioc
, buf
, 18, errp
) < 0) {
1381 error_prepend(errp
, "write failed: ");
1384 ret
= nbd_negotiate_options(client
, errp
);
1387 error_prepend(errp
, "option negotiation failed: ");
1392 assert(!client
->optlen
);
1393 trace_nbd_negotiate_success();
1399 * Tries to read @size bytes from @ioc. This is a local implementation of
1400 * qio_channel_readv_all_eof. We have it here because we need it to be
1401 * interruptible and to know when the coroutine is yielding.
1402 * Returns 1 on success
1403 * 0 on eof, when no data was read (errp is not set)
1404 * negative errno on failure (errp is set)
1406 static inline int coroutine_fn
1407 nbd_read_eof(NBDClient
*client
, void *buffer
, size_t size
, Error
**errp
)
1409 bool partial
= false;
1413 struct iovec iov
= { .iov_base
= buffer
, .iov_len
= size
};
1416 len
= qio_channel_readv(client
->ioc
, &iov
, 1, errp
);
1417 if (len
== QIO_CHANNEL_ERR_BLOCK
) {
1418 client
->read_yielding
= true;
1419 qio_channel_yield(client
->ioc
, G_IO_IN
);
1420 client
->read_yielding
= false;
1421 if (client
->quiescing
) {
1425 } else if (len
< 0) {
1427 } else if (len
== 0) {
1430 "Unexpected end-of-file before all bytes were read");
1439 buffer
= (uint8_t *) buffer
+ len
;
1444 static int coroutine_fn
nbd_receive_request(NBDClient
*client
, NBDRequest
*request
,
1447 uint8_t buf
[NBD_EXTENDED_REQUEST_SIZE
];
1448 uint32_t magic
, expect
;
1450 size_t size
= client
->mode
>= NBD_MODE_EXTENDED
?
1451 NBD_EXTENDED_REQUEST_SIZE
: NBD_REQUEST_SIZE
;
1453 ret
= nbd_read_eof(client
, buf
, size
, errp
);
1463 * [ 0 .. 3] magic (NBD_REQUEST_MAGIC)
1464 * [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...)
1465 * [ 6 .. 7] type (NBD_CMD_READ, ...)
1470 * [ 0 .. 3] magic (NBD_EXTENDED_REQUEST_MAGIC)
1471 * [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, NBD_CMD_FLAG_PAYLOAD_LEN, ...)
1472 * [ 6 .. 7] type (NBD_CMD_READ, ...)
1478 magic
= ldl_be_p(buf
);
1479 request
->flags
= lduw_be_p(buf
+ 4);
1480 request
->type
= lduw_be_p(buf
+ 6);
1481 request
->cookie
= ldq_be_p(buf
+ 8);
1482 request
->from
= ldq_be_p(buf
+ 16);
1483 if (client
->mode
>= NBD_MODE_EXTENDED
) {
1484 request
->len
= ldq_be_p(buf
+ 24);
1485 expect
= NBD_EXTENDED_REQUEST_MAGIC
;
1487 request
->len
= (uint32_t)ldl_be_p(buf
+ 24); /* widen 32 to 64 bits */
1488 expect
= NBD_REQUEST_MAGIC
;
1491 trace_nbd_receive_request(magic
, request
->flags
, request
->type
,
1492 request
->from
, request
->len
);
1494 if (magic
!= expect
) {
1495 error_setg(errp
, "invalid magic (got 0x%" PRIx32
", expected 0x%"
1496 PRIx32
")", magic
, expect
);
1502 #define MAX_NBD_REQUESTS 16
1504 void nbd_client_get(NBDClient
*client
)
1509 void nbd_client_put(NBDClient
*client
)
1511 if (--client
->refcount
== 0) {
1512 /* The last reference should be dropped by client->close,
1513 * which is called by client_close.
1515 assert(client
->closing
);
1517 object_unref(OBJECT(client
->sioc
));
1518 object_unref(OBJECT(client
->ioc
));
1519 if (client
->tlscreds
) {
1520 object_unref(OBJECT(client
->tlscreds
));
1522 g_free(client
->tlsauthz
);
1524 QTAILQ_REMOVE(&client
->exp
->clients
, client
, next
);
1525 blk_exp_unref(&client
->exp
->common
);
1527 g_free(client
->contexts
.bitmaps
);
1532 static void client_close(NBDClient
*client
, bool negotiated
)
1534 if (client
->closing
) {
1538 client
->closing
= true;
1540 /* Force requests to finish. They will drop their own references,
1541 * then we'll close the socket and free the NBDClient.
1543 qio_channel_shutdown(client
->ioc
, QIO_CHANNEL_SHUTDOWN_BOTH
,
1546 /* Also tell the client, so that they release their reference. */
1547 if (client
->close_fn
) {
1548 client
->close_fn(client
, negotiated
);
1552 static NBDRequestData
*nbd_request_get(NBDClient
*client
)
1554 NBDRequestData
*req
;
1556 assert(client
->nb_requests
<= MAX_NBD_REQUESTS
- 1);
1557 client
->nb_requests
++;
1559 req
= g_new0(NBDRequestData
, 1);
1560 nbd_client_get(client
);
1561 req
->client
= client
;
1565 static void nbd_request_put(NBDRequestData
*req
)
1567 NBDClient
*client
= req
->client
;
1570 qemu_vfree(req
->data
);
1574 client
->nb_requests
--;
1576 if (client
->quiescing
&& client
->nb_requests
== 0) {
1580 nbd_client_receive_next_request(client
);
1582 nbd_client_put(client
);
1585 static void blk_aio_attached(AioContext
*ctx
, void *opaque
)
1587 NBDExport
*exp
= opaque
;
1590 trace_nbd_blk_aio_attached(exp
->name
, ctx
);
1592 exp
->common
.ctx
= ctx
;
1594 QTAILQ_FOREACH(client
, &exp
->clients
, next
) {
1595 assert(client
->nb_requests
== 0);
1596 assert(client
->recv_coroutine
== NULL
);
1597 assert(client
->send_coroutine
== NULL
);
1601 static void blk_aio_detach(void *opaque
)
1603 NBDExport
*exp
= opaque
;
1605 trace_nbd_blk_aio_detach(exp
->name
, exp
->common
.ctx
);
1607 exp
->common
.ctx
= NULL
;
1610 static void nbd_drained_begin(void *opaque
)
1612 NBDExport
*exp
= opaque
;
1615 QTAILQ_FOREACH(client
, &exp
->clients
, next
) {
1616 client
->quiescing
= true;
1620 static void nbd_drained_end(void *opaque
)
1622 NBDExport
*exp
= opaque
;
1625 QTAILQ_FOREACH(client
, &exp
->clients
, next
) {
1626 client
->quiescing
= false;
1627 nbd_client_receive_next_request(client
);
1631 static bool nbd_drained_poll(void *opaque
)
1633 NBDExport
*exp
= opaque
;
1636 QTAILQ_FOREACH(client
, &exp
->clients
, next
) {
1637 if (client
->nb_requests
!= 0) {
1639 * If there's a coroutine waiting for a request on nbd_read_eof()
1640 * enter it here so we don't depend on the client to wake it up.
1642 if (client
->recv_coroutine
!= NULL
&& client
->read_yielding
) {
1643 qio_channel_wake_read(client
->ioc
);
1653 static void nbd_eject_notifier(Notifier
*n
, void *data
)
1655 NBDExport
*exp
= container_of(n
, NBDExport
, eject_notifier
);
1657 blk_exp_request_shutdown(&exp
->common
);
1660 void nbd_export_set_on_eject_blk(BlockExport
*exp
, BlockBackend
*blk
)
1662 NBDExport
*nbd_exp
= container_of(exp
, NBDExport
, common
);
1663 assert(exp
->drv
== &blk_exp_nbd
);
1664 assert(nbd_exp
->eject_notifier_blk
== NULL
);
1667 nbd_exp
->eject_notifier_blk
= blk
;
1668 nbd_exp
->eject_notifier
.notify
= nbd_eject_notifier
;
1669 blk_add_remove_bs_notifier(blk
, &nbd_exp
->eject_notifier
);
1672 static const BlockDevOps nbd_block_ops
= {
1673 .drained_begin
= nbd_drained_begin
,
1674 .drained_end
= nbd_drained_end
,
1675 .drained_poll
= nbd_drained_poll
,
1678 static int nbd_export_create(BlockExport
*blk_exp
, BlockExportOptions
*exp_args
,
1681 NBDExport
*exp
= container_of(blk_exp
, NBDExport
, common
);
1682 BlockExportOptionsNbd
*arg
= &exp_args
->u
.nbd
;
1683 const char *name
= arg
->name
?: exp_args
->node_name
;
1684 BlockBackend
*blk
= blk_exp
->blk
;
1686 uint64_t perm
, shared_perm
;
1687 bool readonly
= !exp_args
->writable
;
1688 BlockDirtyBitmapOrStrList
*bitmaps
;
1692 GLOBAL_STATE_CODE();
1693 assert(exp_args
->type
== BLOCK_EXPORT_TYPE_NBD
);
1695 if (!nbd_server_is_running()) {
1696 error_setg(errp
, "NBD server not running");
1700 if (strlen(name
) > NBD_MAX_STRING_SIZE
) {
1701 error_setg(errp
, "export name '%s' too long", name
);
1705 if (arg
->description
&& strlen(arg
->description
) > NBD_MAX_STRING_SIZE
) {
1706 error_setg(errp
, "description '%s' too long", arg
->description
);
1710 if (nbd_export_find(name
)) {
1711 error_setg(errp
, "NBD server already has export named '%s'", name
);
1715 size
= blk_getlength(blk
);
1717 error_setg_errno(errp
, -size
,
1718 "Failed to determine the NBD export's length");
1722 /* Don't allow resize while the NBD server is running, otherwise we don't
1723 * care what happens with the node. */
1724 blk_get_perm(blk
, &perm
, &shared_perm
);
1725 ret
= blk_set_perm(blk
, perm
, shared_perm
& ~BLK_PERM_RESIZE
, errp
);
1730 QTAILQ_INIT(&exp
->clients
);
1731 exp
->name
= g_strdup(name
);
1732 exp
->description
= g_strdup(arg
->description
);
1733 exp
->nbdflags
= (NBD_FLAG_HAS_FLAGS
| NBD_FLAG_SEND_FLUSH
|
1734 NBD_FLAG_SEND_FUA
| NBD_FLAG_SEND_CACHE
);
1736 if (nbd_server_max_connections() != 1) {
1737 exp
->nbdflags
|= NBD_FLAG_CAN_MULTI_CONN
;
1740 exp
->nbdflags
|= NBD_FLAG_READ_ONLY
;
1742 exp
->nbdflags
|= (NBD_FLAG_SEND_TRIM
| NBD_FLAG_SEND_WRITE_ZEROES
|
1743 NBD_FLAG_SEND_FAST_ZERO
);
1745 exp
->size
= QEMU_ALIGN_DOWN(size
, BDRV_SECTOR_SIZE
);
1747 bdrv_graph_rdlock_main_loop();
1749 for (bitmaps
= arg
->bitmaps
; bitmaps
; bitmaps
= bitmaps
->next
) {
1750 exp
->nr_export_bitmaps
++;
1752 exp
->export_bitmaps
= g_new0(BdrvDirtyBitmap
*, exp
->nr_export_bitmaps
);
1753 for (i
= 0, bitmaps
= arg
->bitmaps
; bitmaps
;
1754 i
++, bitmaps
= bitmaps
->next
)
1757 BlockDriverState
*bs
= blk_bs(blk
);
1758 BdrvDirtyBitmap
*bm
= NULL
;
1760 switch (bitmaps
->value
->type
) {
1762 bitmap
= bitmaps
->value
->u
.local
;
1764 bm
= bdrv_find_dirty_bitmap(bs
, bitmap
);
1769 bs
= bdrv_filter_or_cow_bs(bs
);
1774 error_setg(errp
, "Bitmap '%s' is not found",
1775 bitmaps
->value
->u
.local
);
1779 if (readonly
&& bdrv_is_writable(bs
) &&
1780 bdrv_dirty_bitmap_enabled(bm
)) {
1782 error_setg(errp
, "Enabled bitmap '%s' incompatible with "
1783 "readonly export", bitmap
);
1788 bitmap
= bitmaps
->value
->u
.external
.name
;
1789 bm
= block_dirty_bitmap_lookup(bitmaps
->value
->u
.external
.node
,
1790 bitmap
, NULL
, errp
);
1802 if (bdrv_dirty_bitmap_check(bm
, BDRV_BITMAP_ALLOW_RO
, errp
)) {
1807 exp
->export_bitmaps
[i
] = bm
;
1808 assert(strlen(bitmap
) <= BDRV_BITMAP_MAX_NAME_SIZE
);
1811 /* Mark bitmaps busy in a separate loop, to simplify roll-back concerns. */
1812 for (i
= 0; i
< exp
->nr_export_bitmaps
; i
++) {
1813 bdrv_dirty_bitmap_set_busy(exp
->export_bitmaps
[i
], true);
1816 exp
->allocation_depth
= arg
->allocation_depth
;
1819 * We need to inhibit request queuing in the block layer to ensure we can
1820 * be properly quiesced when entering a drained section, as our coroutines
1821 * servicing pending requests might enter blk_pread().
1823 blk_set_disable_request_queuing(blk
, true);
1825 blk_add_aio_context_notifier(blk
, blk_aio_attached
, blk_aio_detach
, exp
);
1827 blk_set_dev_ops(blk
, &nbd_block_ops
, exp
);
1829 QTAILQ_INSERT_TAIL(&exports
, exp
, next
);
1831 bdrv_graph_rdunlock_main_loop();
1836 bdrv_graph_rdunlock_main_loop();
1837 g_free(exp
->export_bitmaps
);
1839 g_free(exp
->description
);
1843 NBDExport
*nbd_export_find(const char *name
)
1846 QTAILQ_FOREACH(exp
, &exports
, next
) {
1847 if (strcmp(name
, exp
->name
) == 0) {
1856 nbd_export_aio_context(NBDExport
*exp
)
1858 return exp
->common
.ctx
;
1861 static void nbd_export_request_shutdown(BlockExport
*blk_exp
)
1863 NBDExport
*exp
= container_of(blk_exp
, NBDExport
, common
);
1864 NBDClient
*client
, *next
;
1866 blk_exp_ref(&exp
->common
);
1868 * TODO: Should we expand QMP NbdServerRemoveNode enum to allow a
1869 * close mode that stops advertising the export to new clients but
1870 * still permits existing clients to run to completion? Because of
1871 * that possibility, nbd_export_close() can be called more than
1872 * once on an export.
1874 QTAILQ_FOREACH_SAFE(client
, &exp
->clients
, next
, next
) {
1875 client_close(client
, true);
1880 QTAILQ_REMOVE(&exports
, exp
, next
);
1882 blk_exp_unref(&exp
->common
);
1885 static void nbd_export_delete(BlockExport
*blk_exp
)
1888 NBDExport
*exp
= container_of(blk_exp
, NBDExport
, common
);
1890 assert(exp
->name
== NULL
);
1891 assert(QTAILQ_EMPTY(&exp
->clients
));
1893 g_free(exp
->description
);
1894 exp
->description
= NULL
;
1896 if (exp
->eject_notifier_blk
) {
1897 notifier_remove(&exp
->eject_notifier
);
1898 blk_unref(exp
->eject_notifier_blk
);
1900 blk_remove_aio_context_notifier(exp
->common
.blk
, blk_aio_attached
,
1901 blk_aio_detach
, exp
);
1902 blk_set_disable_request_queuing(exp
->common
.blk
, false);
1904 for (i
= 0; i
< exp
->nr_export_bitmaps
; i
++) {
1905 bdrv_dirty_bitmap_set_busy(exp
->export_bitmaps
[i
], false);
1909 const BlockExportDriver blk_exp_nbd
= {
1910 .type
= BLOCK_EXPORT_TYPE_NBD
,
1911 .instance_size
= sizeof(NBDExport
),
1912 .create
= nbd_export_create
,
1913 .delete = nbd_export_delete
,
1914 .request_shutdown
= nbd_export_request_shutdown
,
1917 static int coroutine_fn
nbd_co_send_iov(NBDClient
*client
, struct iovec
*iov
,
1918 unsigned niov
, Error
**errp
)
1922 g_assert(qemu_in_coroutine());
1923 qemu_co_mutex_lock(&client
->send_lock
);
1924 client
->send_coroutine
= qemu_coroutine_self();
1926 ret
= qio_channel_writev_all(client
->ioc
, iov
, niov
, errp
) < 0 ? -EIO
: 0;
1928 client
->send_coroutine
= NULL
;
1929 qemu_co_mutex_unlock(&client
->send_lock
);
1934 static inline void set_be_simple_reply(NBDSimpleReply
*reply
, uint64_t error
,
1937 stl_be_p(&reply
->magic
, NBD_SIMPLE_REPLY_MAGIC
);
1938 stl_be_p(&reply
->error
, error
);
1939 stq_be_p(&reply
->cookie
, cookie
);
1942 static int coroutine_fn
nbd_co_send_simple_reply(NBDClient
*client
,
1943 NBDRequest
*request
,
1949 NBDSimpleReply reply
;
1950 int nbd_err
= system_errno_to_nbd_errno(error
);
1951 struct iovec iov
[] = {
1952 {.iov_base
= &reply
, .iov_len
= sizeof(reply
)},
1953 {.iov_base
= data
, .iov_len
= len
}
1956 assert(!len
|| !nbd_err
);
1957 assert(len
<= NBD_MAX_BUFFER_SIZE
);
1958 assert(client
->mode
< NBD_MODE_STRUCTURED
||
1959 (client
->mode
== NBD_MODE_STRUCTURED
&&
1960 request
->type
!= NBD_CMD_READ
));
1961 trace_nbd_co_send_simple_reply(request
->cookie
, nbd_err
,
1962 nbd_err_lookup(nbd_err
), len
);
1963 set_be_simple_reply(&reply
, nbd_err
, request
->cookie
);
1965 return nbd_co_send_iov(client
, iov
, 2, errp
);
1969 * Prepare the header of a reply chunk for network transmission.
1971 * On input, @iov is partially initialized: iov[0].iov_base must point
1972 * to an uninitialized NBDReply, while the remaining @niov elements
1973 * (if any) must be ready for transmission. This function then
1974 * populates iov[0] for transmission.
1976 static inline void set_be_chunk(NBDClient
*client
, struct iovec
*iov
,
1977 size_t niov
, uint16_t flags
, uint16_t type
,
1978 NBDRequest
*request
)
1980 size_t i
, length
= 0;
1982 for (i
= 1; i
< niov
; i
++) {
1983 length
+= iov
[i
].iov_len
;
1985 assert(length
<= NBD_MAX_BUFFER_SIZE
+ sizeof(NBDStructuredReadData
));
1987 if (client
->mode
>= NBD_MODE_EXTENDED
) {
1988 NBDExtendedReplyChunk
*chunk
= iov
->iov_base
;
1990 iov
[0].iov_len
= sizeof(*chunk
);
1991 stl_be_p(&chunk
->magic
, NBD_EXTENDED_REPLY_MAGIC
);
1992 stw_be_p(&chunk
->flags
, flags
);
1993 stw_be_p(&chunk
->type
, type
);
1994 stq_be_p(&chunk
->cookie
, request
->cookie
);
1995 stq_be_p(&chunk
->offset
, request
->from
);
1996 stq_be_p(&chunk
->length
, length
);
1998 NBDStructuredReplyChunk
*chunk
= iov
->iov_base
;
2000 iov
[0].iov_len
= sizeof(*chunk
);
2001 stl_be_p(&chunk
->magic
, NBD_STRUCTURED_REPLY_MAGIC
);
2002 stw_be_p(&chunk
->flags
, flags
);
2003 stw_be_p(&chunk
->type
, type
);
2004 stq_be_p(&chunk
->cookie
, request
->cookie
);
2005 stl_be_p(&chunk
->length
, length
);
2009 static int coroutine_fn
nbd_co_send_chunk_done(NBDClient
*client
,
2010 NBDRequest
*request
,
2014 struct iovec iov
[] = {
2018 trace_nbd_co_send_chunk_done(request
->cookie
);
2019 set_be_chunk(client
, iov
, 1, NBD_REPLY_FLAG_DONE
,
2020 NBD_REPLY_TYPE_NONE
, request
);
2021 return nbd_co_send_iov(client
, iov
, 1, errp
);
2024 static int coroutine_fn
nbd_co_send_chunk_read(NBDClient
*client
,
2025 NBDRequest
*request
,
2033 NBDStructuredReadData chunk
;
2034 struct iovec iov
[] = {
2036 {.iov_base
= &chunk
, .iov_len
= sizeof(chunk
)},
2037 {.iov_base
= data
, .iov_len
= size
}
2040 assert(size
&& size
<= NBD_MAX_BUFFER_SIZE
);
2041 trace_nbd_co_send_chunk_read(request
->cookie
, offset
, data
, size
);
2042 set_be_chunk(client
, iov
, 3, final
? NBD_REPLY_FLAG_DONE
: 0,
2043 NBD_REPLY_TYPE_OFFSET_DATA
, request
);
2044 stq_be_p(&chunk
.offset
, offset
);
2046 return nbd_co_send_iov(client
, iov
, 3, errp
);
2049 static int coroutine_fn
nbd_co_send_chunk_error(NBDClient
*client
,
2050 NBDRequest
*request
,
2056 NBDStructuredError chunk
;
2057 int nbd_err
= system_errno_to_nbd_errno(error
);
2058 struct iovec iov
[] = {
2060 {.iov_base
= &chunk
, .iov_len
= sizeof(chunk
)},
2061 {.iov_base
= (char *)msg
, .iov_len
= msg
? strlen(msg
) : 0},
2065 trace_nbd_co_send_chunk_error(request
->cookie
, nbd_err
,
2066 nbd_err_lookup(nbd_err
), msg
? msg
: "");
2067 set_be_chunk(client
, iov
, 3, NBD_REPLY_FLAG_DONE
,
2068 NBD_REPLY_TYPE_ERROR
, request
);
2069 stl_be_p(&chunk
.error
, nbd_err
);
2070 stw_be_p(&chunk
.message_length
, iov
[2].iov_len
);
2072 return nbd_co_send_iov(client
, iov
, 3, errp
);
2075 /* Do a sparse read and send the structured reply to the client.
2076 * Returns -errno if sending fails. blk_co_block_status_above() failure is
2077 * reported to the client, at which point this function succeeds.
2079 static int coroutine_fn
nbd_co_send_sparse_read(NBDClient
*client
,
2080 NBDRequest
*request
,
2087 NBDExport
*exp
= client
->exp
;
2088 size_t progress
= 0;
2090 assert(size
<= NBD_MAX_BUFFER_SIZE
);
2091 while (progress
< size
) {
2093 int status
= blk_co_block_status_above(exp
->common
.blk
, NULL
,
2095 size
- progress
, &pnum
, NULL
,
2100 char *msg
= g_strdup_printf("unable to check for holes: %s",
2103 ret
= nbd_co_send_chunk_error(client
, request
, -status
, msg
, errp
);
2107 assert(pnum
&& pnum
<= size
- progress
);
2108 final
= progress
+ pnum
== size
;
2109 if (status
& BDRV_BLOCK_ZERO
) {
2111 NBDStructuredReadHole chunk
;
2112 struct iovec iov
[] = {
2114 {.iov_base
= &chunk
, .iov_len
= sizeof(chunk
)},
2117 trace_nbd_co_send_chunk_read_hole(request
->cookie
,
2118 offset
+ progress
, pnum
);
2119 set_be_chunk(client
, iov
, 2,
2120 final
? NBD_REPLY_FLAG_DONE
: 0,
2121 NBD_REPLY_TYPE_OFFSET_HOLE
, request
);
2122 stq_be_p(&chunk
.offset
, offset
+ progress
);
2123 stl_be_p(&chunk
.length
, pnum
);
2124 ret
= nbd_co_send_iov(client
, iov
, 2, errp
);
2126 ret
= blk_co_pread(exp
->common
.blk
, offset
+ progress
, pnum
,
2127 data
+ progress
, 0);
2129 error_setg_errno(errp
, -ret
, "reading from file failed");
2132 ret
= nbd_co_send_chunk_read(client
, request
, offset
+ progress
,
2133 data
+ progress
, pnum
, final
, errp
);
2144 typedef struct NBDExtentArray
{
2145 NBDExtent64
*extents
;
2146 unsigned int nb_alloc
;
2148 uint64_t total_length
;
2151 bool converted_to_be
;
2154 static NBDExtentArray
*nbd_extent_array_new(unsigned int nb_alloc
,
2157 NBDExtentArray
*ea
= g_new0(NBDExtentArray
, 1);
2159 assert(mode
>= NBD_MODE_STRUCTURED
);
2160 ea
->nb_alloc
= nb_alloc
;
2161 ea
->extents
= g_new(NBDExtent64
, nb_alloc
);
2162 ea
->extended
= mode
>= NBD_MODE_EXTENDED
;
2168 static void nbd_extent_array_free(NBDExtentArray
*ea
)
2170 g_free(ea
->extents
);
2173 G_DEFINE_AUTOPTR_CLEANUP_FUNC(NBDExtentArray
, nbd_extent_array_free
)
2175 /* Further modifications of the array after conversion are abandoned */
2176 static void nbd_extent_array_convert_to_be(NBDExtentArray
*ea
)
2180 assert(!ea
->converted_to_be
);
2181 assert(ea
->extended
);
2182 ea
->can_add
= false;
2183 ea
->converted_to_be
= true;
2185 for (i
= 0; i
< ea
->count
; i
++) {
2186 ea
->extents
[i
].length
= cpu_to_be64(ea
->extents
[i
].length
);
2187 ea
->extents
[i
].flags
= cpu_to_be64(ea
->extents
[i
].flags
);
2191 /* Further modifications of the array after conversion are abandoned */
2192 static NBDExtent32
*nbd_extent_array_convert_to_narrow(NBDExtentArray
*ea
)
2195 NBDExtent32
*extents
= g_new(NBDExtent32
, ea
->count
);
2197 assert(!ea
->converted_to_be
);
2198 assert(!ea
->extended
);
2199 ea
->can_add
= false;
2200 ea
->converted_to_be
= true;
2202 for (i
= 0; i
< ea
->count
; i
++) {
2203 assert((ea
->extents
[i
].length
| ea
->extents
[i
].flags
) <= UINT32_MAX
);
2204 extents
[i
].length
= cpu_to_be32(ea
->extents
[i
].length
);
2205 extents
[i
].flags
= cpu_to_be32(ea
->extents
[i
].flags
);
2212 * Add extent to NBDExtentArray. If extent can't be added (no available space),
2214 * For safety, when returning -1 for the first time, .can_add is set to false,
2215 * and further calls to nbd_extent_array_add() will crash.
2216 * (this avoids the situation where a caller ignores failure to add one extent,
2217 * where adding another extent that would squash into the last array entry
2218 * would result in an incorrect range reported to the client)
2220 static int nbd_extent_array_add(NBDExtentArray
*ea
,
2221 uint64_t length
, uint32_t flags
)
2223 assert(ea
->can_add
);
2228 if (!ea
->extended
) {
2229 assert(length
<= UINT32_MAX
);
2232 /* Extend previous extent if flags are the same */
2233 if (ea
->count
> 0 && flags
== ea
->extents
[ea
->count
- 1].flags
) {
2234 uint64_t sum
= length
+ ea
->extents
[ea
->count
- 1].length
;
2237 * sum cannot overflow: the block layer bounds image size at
2238 * 2^63, and ea->extents[].length comes from the block layer.
2240 assert(sum
>= length
);
2241 if (sum
<= UINT32_MAX
|| ea
->extended
) {
2242 ea
->extents
[ea
->count
- 1].length
= sum
;
2243 ea
->total_length
+= length
;
2248 if (ea
->count
>= ea
->nb_alloc
) {
2249 ea
->can_add
= false;
2253 ea
->total_length
+= length
;
2254 ea
->extents
[ea
->count
] = (NBDExtent64
) {.length
= length
, .flags
= flags
};
2260 static int coroutine_fn
blockstatus_to_extents(BlockBackend
*blk
,
2261 uint64_t offset
, uint64_t bytes
,
2267 int ret
= blk_co_block_status_above(blk
, NULL
, offset
, bytes
, &num
,
2274 flags
= (ret
& BDRV_BLOCK_DATA
? 0 : NBD_STATE_HOLE
) |
2275 (ret
& BDRV_BLOCK_ZERO
? NBD_STATE_ZERO
: 0);
2277 if (nbd_extent_array_add(ea
, num
, flags
) < 0) {
2288 static int coroutine_fn
blockalloc_to_extents(BlockBackend
*blk
,
2289 uint64_t offset
, uint64_t bytes
,
2294 int ret
= blk_co_is_allocated_above(blk
, NULL
, false, offset
, bytes
,
2301 if (nbd_extent_array_add(ea
, num
, ret
) < 0) {
2313 * nbd_co_send_extents
2315 * @ea is converted to BE by the function
2316 * @last controls whether NBD_REPLY_FLAG_DONE is sent.
2318 static int coroutine_fn
2319 nbd_co_send_extents(NBDClient
*client
, NBDRequest
*request
, NBDExtentArray
*ea
,
2320 bool last
, uint32_t context_id
, Error
**errp
)
2323 NBDStructuredMeta meta
;
2324 NBDExtendedMeta meta_ext
;
2325 g_autofree NBDExtent32
*extents
= NULL
;
2327 struct iovec iov
[] = { {.iov_base
= &hdr
}, {0}, {0} };
2329 if (client
->mode
>= NBD_MODE_EXTENDED
) {
2330 type
= NBD_REPLY_TYPE_BLOCK_STATUS_EXT
;
2332 iov
[1].iov_base
= &meta_ext
;
2333 iov
[1].iov_len
= sizeof(meta_ext
);
2334 stl_be_p(&meta_ext
.context_id
, context_id
);
2335 stl_be_p(&meta_ext
.count
, ea
->count
);
2337 nbd_extent_array_convert_to_be(ea
);
2338 iov
[2].iov_base
= ea
->extents
;
2339 iov
[2].iov_len
= ea
->count
* sizeof(ea
->extents
[0]);
2341 type
= NBD_REPLY_TYPE_BLOCK_STATUS
;
2343 iov
[1].iov_base
= &meta
;
2344 iov
[1].iov_len
= sizeof(meta
);
2345 stl_be_p(&meta
.context_id
, context_id
);
2347 extents
= nbd_extent_array_convert_to_narrow(ea
);
2348 iov
[2].iov_base
= extents
;
2349 iov
[2].iov_len
= ea
->count
* sizeof(extents
[0]);
2352 trace_nbd_co_send_extents(request
->cookie
, ea
->count
, context_id
,
2353 ea
->total_length
, last
);
2354 set_be_chunk(client
, iov
, 3, last
? NBD_REPLY_FLAG_DONE
: 0, type
,
2357 return nbd_co_send_iov(client
, iov
, 3, errp
);
2360 /* Get block status from the exported device and send it to the client */
2362 coroutine_fn
nbd_co_send_block_status(NBDClient
*client
, NBDRequest
*request
,
2363 BlockBackend
*blk
, uint64_t offset
,
2364 uint64_t length
, bool dont_fragment
,
2365 bool last
, uint32_t context_id
,
2369 unsigned int nb_extents
= dont_fragment
? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS
;
2370 g_autoptr(NBDExtentArray
) ea
=
2371 nbd_extent_array_new(nb_extents
, client
->mode
);
2373 if (context_id
== NBD_META_ID_BASE_ALLOCATION
) {
2374 ret
= blockstatus_to_extents(blk
, offset
, length
, ea
);
2376 ret
= blockalloc_to_extents(blk
, offset
, length
, ea
);
2379 return nbd_co_send_chunk_error(client
, request
, -ret
,
2380 "can't get block status", errp
);
2383 return nbd_co_send_extents(client
, request
, ea
, last
, context_id
, errp
);
2386 /* Populate @ea from a dirty bitmap. */
2387 static void bitmap_to_extents(BdrvDirtyBitmap
*bitmap
,
2388 uint64_t offset
, uint64_t length
,
2391 int64_t start
, dirty_start
, dirty_count
;
2392 int64_t end
= offset
+ length
;
2394 int64_t bound
= es
->extended
? INT64_MAX
: INT32_MAX
;
2396 bdrv_dirty_bitmap_lock(bitmap
);
2398 for (start
= offset
;
2399 bdrv_dirty_bitmap_next_dirty_area(bitmap
, start
, end
, bound
,
2400 &dirty_start
, &dirty_count
);
2401 start
= dirty_start
+ dirty_count
)
2403 if ((nbd_extent_array_add(es
, dirty_start
- start
, 0) < 0) ||
2404 (nbd_extent_array_add(es
, dirty_count
, NBD_STATE_DIRTY
) < 0))
2412 /* last non dirty extent, nothing to do if array is now full */
2413 (void) nbd_extent_array_add(es
, end
- start
, 0);
2416 bdrv_dirty_bitmap_unlock(bitmap
);
2419 static int coroutine_fn
nbd_co_send_bitmap(NBDClient
*client
,
2420 NBDRequest
*request
,
2421 BdrvDirtyBitmap
*bitmap
,
2423 uint64_t length
, bool dont_fragment
,
2424 bool last
, uint32_t context_id
,
2427 unsigned int nb_extents
= dont_fragment
? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS
;
2428 g_autoptr(NBDExtentArray
) ea
=
2429 nbd_extent_array_new(nb_extents
, client
->mode
);
2431 bitmap_to_extents(bitmap
, offset
, length
, ea
);
2433 return nbd_co_send_extents(client
, request
, ea
, last
, context_id
, errp
);
2437 * nbd_co_block_status_payload_read
2438 * Called when a client wants a subset of negotiated contexts via a
2439 * BLOCK_STATUS payload. Check the payload for valid length and
2440 * contents. On success, return 0 with request updated to effective
2441 * length. If request was invalid but all payload consumed, return 0
2442 * with request->len and request->contexts->count set to 0 (which will
2443 * trigger an appropriate NBD_EINVAL response later on). Return
2444 * negative errno if the payload was not fully consumed.
2447 nbd_co_block_status_payload_read(NBDClient
*client
, NBDRequest
*request
,
2450 uint64_t payload_len
= request
->len
;
2451 g_autofree
char *buf
= NULL
;
2452 size_t count
, i
, nr_bitmaps
;
2455 if (payload_len
> NBD_MAX_BUFFER_SIZE
) {
2456 error_setg(errp
, "len (%" PRIu64
") is larger than max len (%u)",
2457 request
->len
, NBD_MAX_BUFFER_SIZE
);
2461 assert(client
->contexts
.exp
== client
->exp
);
2462 nr_bitmaps
= client
->exp
->nr_export_bitmaps
;
2463 request
->contexts
= g_new0(NBDMetaContexts
, 1);
2464 request
->contexts
->exp
= client
->exp
;
2466 if (payload_len
% sizeof(uint32_t) ||
2467 payload_len
< sizeof(NBDBlockStatusPayload
) ||
2468 payload_len
> (sizeof(NBDBlockStatusPayload
) +
2469 sizeof(id
) * client
->contexts
.count
)) {
2473 buf
= g_malloc(payload_len
);
2474 if (nbd_read(client
->ioc
, buf
, payload_len
,
2475 "CMD_BLOCK_STATUS data", errp
) < 0) {
2478 trace_nbd_co_receive_request_payload_received(request
->cookie
,
2480 request
->contexts
->bitmaps
= g_new0(bool, nr_bitmaps
);
2481 count
= (payload_len
- sizeof(NBDBlockStatusPayload
)) / sizeof(id
);
2484 for (i
= 0; i
< count
; i
++) {
2485 id
= ldl_be_p(buf
+ sizeof(NBDBlockStatusPayload
) + sizeof(id
) * i
);
2486 if (id
== NBD_META_ID_BASE_ALLOCATION
) {
2487 if (!client
->contexts
.base_allocation
||
2488 request
->contexts
->base_allocation
) {
2491 request
->contexts
->base_allocation
= true;
2492 } else if (id
== NBD_META_ID_ALLOCATION_DEPTH
) {
2493 if (!client
->contexts
.allocation_depth
||
2494 request
->contexts
->allocation_depth
) {
2497 request
->contexts
->allocation_depth
= true;
2499 unsigned idx
= id
- NBD_META_ID_DIRTY_BITMAP
;
2501 if (idx
>= nr_bitmaps
|| !client
->contexts
.bitmaps
[idx
] ||
2502 request
->contexts
->bitmaps
[idx
]) {
2505 request
->contexts
->bitmaps
[idx
] = true;
2509 request
->len
= ldq_be_p(buf
);
2510 request
->contexts
->count
= count
;
2514 trace_nbd_co_receive_block_status_payload_compliance(request
->from
,
2516 request
->len
= request
->contexts
->count
= 0;
2517 return nbd_drop(client
->ioc
, payload_len
, errp
);
2520 /* nbd_co_receive_request
2521 * Collect a client request. Return 0 if request looks valid, -EIO to drop
2522 * connection right away, -EAGAIN to indicate we were interrupted and the
2523 * channel should be quiesced, and any other negative value to report an error
2524 * to the client (although the caller may still need to disconnect after
2525 * reporting the error).
2527 static int coroutine_fn
nbd_co_receive_request(NBDRequestData
*req
,
2528 NBDRequest
*request
,
2531 NBDClient
*client
= req
->client
;
2532 bool extended_with_payload
;
2533 bool check_length
= false;
2534 bool check_rofs
= false;
2535 bool allocate_buffer
= false;
2536 bool payload_okay
= false;
2537 uint64_t payload_len
= 0;
2538 int valid_flags
= NBD_CMD_FLAG_FUA
;
2541 g_assert(qemu_in_coroutine());
2542 assert(client
->recv_coroutine
== qemu_coroutine_self());
2543 ret
= nbd_receive_request(client
, request
, errp
);
2548 trace_nbd_co_receive_request_decode_type(request
->cookie
, request
->type
,
2549 nbd_cmd_lookup(request
->type
));
2550 extended_with_payload
= client
->mode
>= NBD_MODE_EXTENDED
&&
2551 request
->flags
& NBD_CMD_FLAG_PAYLOAD_LEN
;
2552 if (extended_with_payload
) {
2553 payload_len
= request
->len
;
2554 check_length
= true;
2557 switch (request
->type
) {
2559 /* Special case: we're going to disconnect without a reply,
2560 * whether or not flags, from, or len are bogus */
2561 req
->complete
= true;
2565 if (client
->mode
>= NBD_MODE_STRUCTURED
) {
2566 valid_flags
|= NBD_CMD_FLAG_DF
;
2568 check_length
= true;
2569 allocate_buffer
= true;
2573 if (client
->mode
>= NBD_MODE_EXTENDED
) {
2574 if (!extended_with_payload
) {
2575 /* The client is noncompliant. Trace it, but proceed. */
2576 trace_nbd_co_receive_ext_payload_compliance(request
->from
,
2579 valid_flags
|= NBD_CMD_FLAG_PAYLOAD_LEN
;
2581 payload_okay
= true;
2582 payload_len
= request
->len
;
2583 check_length
= true;
2584 allocate_buffer
= true;
2596 check_length
= true;
2599 case NBD_CMD_WRITE_ZEROES
:
2600 valid_flags
|= NBD_CMD_FLAG_NO_HOLE
| NBD_CMD_FLAG_FAST_ZERO
;
2604 case NBD_CMD_BLOCK_STATUS
:
2605 if (extended_with_payload
) {
2606 ret
= nbd_co_block_status_payload_read(client
, request
, errp
);
2610 /* payload now consumed */
2611 check_length
= false;
2613 valid_flags
|= NBD_CMD_FLAG_PAYLOAD_LEN
;
2615 request
->contexts
= &client
->contexts
;
2617 valid_flags
|= NBD_CMD_FLAG_REQ_ONE
;
2621 /* Unrecognized, will fail later */
2625 /* Payload and buffer handling. */
2627 req
->complete
= true;
2629 if (check_length
&& request
->len
> NBD_MAX_BUFFER_SIZE
) {
2630 /* READ, WRITE, CACHE */
2631 error_setg(errp
, "len (%" PRIu64
") is larger than max len (%u)",
2632 request
->len
, NBD_MAX_BUFFER_SIZE
);
2635 if (payload_len
&& !payload_okay
) {
2637 * For now, we don't support payloads on other commands; but
2638 * we can keep the connection alive by ignoring the payload.
2639 * We will fail the command later with NBD_EINVAL for the use
2640 * of an unsupported flag (and not for access beyond bounds).
2642 assert(request
->type
!= NBD_CMD_WRITE
);
2645 if (allocate_buffer
) {
2647 req
->data
= blk_try_blockalign(client
->exp
->common
.blk
,
2649 if (req
->data
== NULL
) {
2650 error_setg(errp
, "No memory");
2658 ret
= nbd_read(client
->ioc
, req
->data
, payload_len
,
2659 "CMD_WRITE data", errp
);
2661 ret
= nbd_drop(client
->ioc
, payload_len
, errp
);
2666 req
->complete
= true;
2667 trace_nbd_co_receive_request_payload_received(request
->cookie
,
2671 /* Sanity checks. */
2672 if (client
->exp
->nbdflags
& NBD_FLAG_READ_ONLY
&& check_rofs
) {
2673 /* WRITE, TRIM, WRITE_ZEROES */
2674 error_setg(errp
, "Export is read-only");
2677 if (request
->from
> client
->exp
->size
||
2678 request
->len
> client
->exp
->size
- request
->from
) {
2679 error_setg(errp
, "operation past EOF; From: %" PRIu64
", Len: %" PRIu64
2680 ", Size: %" PRIu64
, request
->from
, request
->len
,
2682 return (request
->type
== NBD_CMD_WRITE
||
2683 request
->type
== NBD_CMD_WRITE_ZEROES
) ? -ENOSPC
: -EINVAL
;
2685 if (client
->check_align
&& !QEMU_IS_ALIGNED(request
->from
| request
->len
,
2686 client
->check_align
)) {
2688 * The block layer gracefully handles unaligned requests, but
2689 * it's still worth tracing client non-compliance
2691 trace_nbd_co_receive_align_compliance(nbd_cmd_lookup(request
->type
),
2694 client
->check_align
);
2696 if (request
->flags
& ~valid_flags
) {
2697 error_setg(errp
, "unsupported flags for command %s (got 0x%x)",
2698 nbd_cmd_lookup(request
->type
), request
->flags
);
2705 /* Send simple reply without a payload, or a structured error
2706 * @error_msg is ignored if @ret >= 0
2707 * Returns 0 if connection is still live, -errno on failure to talk to client
2709 static coroutine_fn
int nbd_send_generic_reply(NBDClient
*client
,
2710 NBDRequest
*request
,
2712 const char *error_msg
,
2715 if (client
->mode
>= NBD_MODE_STRUCTURED
&& ret
< 0) {
2716 return nbd_co_send_chunk_error(client
, request
, -ret
, error_msg
, errp
);
2717 } else if (client
->mode
>= NBD_MODE_EXTENDED
) {
2718 return nbd_co_send_chunk_done(client
, request
, errp
);
2720 return nbd_co_send_simple_reply(client
, request
, ret
< 0 ? -ret
: 0,
2725 /* Handle NBD_CMD_READ request.
2726 * Return -errno if sending fails. Other errors are reported directly to the
2727 * client as an error reply. */
2728 static coroutine_fn
int nbd_do_cmd_read(NBDClient
*client
, NBDRequest
*request
,
2729 uint8_t *data
, Error
**errp
)
2732 NBDExport
*exp
= client
->exp
;
2734 assert(request
->type
== NBD_CMD_READ
);
2735 assert(request
->len
<= NBD_MAX_BUFFER_SIZE
);
2737 /* XXX: NBD Protocol only documents use of FUA with WRITE */
2738 if (request
->flags
& NBD_CMD_FLAG_FUA
) {
2739 ret
= blk_co_flush(exp
->common
.blk
);
2741 return nbd_send_generic_reply(client
, request
, ret
,
2742 "flush failed", errp
);
2746 if (client
->mode
>= NBD_MODE_STRUCTURED
&&
2747 !(request
->flags
& NBD_CMD_FLAG_DF
) && request
->len
)
2749 return nbd_co_send_sparse_read(client
, request
, request
->from
,
2750 data
, request
->len
, errp
);
2753 ret
= blk_co_pread(exp
->common
.blk
, request
->from
, request
->len
, data
, 0);
2755 return nbd_send_generic_reply(client
, request
, ret
,
2756 "reading from file failed", errp
);
2759 if (client
->mode
>= NBD_MODE_STRUCTURED
) {
2761 return nbd_co_send_chunk_read(client
, request
, request
->from
, data
,
2762 request
->len
, true, errp
);
2764 return nbd_co_send_chunk_done(client
, request
, errp
);
2767 return nbd_co_send_simple_reply(client
, request
, 0,
2768 data
, request
->len
, errp
);
2775 * Handle NBD_CMD_CACHE request.
2776 * Return -errno if sending fails. Other errors are reported directly to the
2777 * client as an error reply.
2779 static coroutine_fn
int nbd_do_cmd_cache(NBDClient
*client
, NBDRequest
*request
,
2783 NBDExport
*exp
= client
->exp
;
2785 assert(request
->type
== NBD_CMD_CACHE
);
2786 assert(request
->len
<= NBD_MAX_BUFFER_SIZE
);
2788 ret
= blk_co_preadv(exp
->common
.blk
, request
->from
, request
->len
,
2789 NULL
, BDRV_REQ_COPY_ON_READ
| BDRV_REQ_PREFETCH
);
2791 return nbd_send_generic_reply(client
, request
, ret
,
2792 "caching data failed", errp
);
2795 /* Handle NBD request.
2796 * Return -errno if sending fails. Other errors are reported directly to the
2797 * client as an error reply. */
2798 static coroutine_fn
int nbd_handle_request(NBDClient
*client
,
2799 NBDRequest
*request
,
2800 uint8_t *data
, Error
**errp
)
2804 NBDExport
*exp
= client
->exp
;
2808 switch (request
->type
) {
2810 return nbd_do_cmd_cache(client
, request
, errp
);
2813 return nbd_do_cmd_read(client
, request
, data
, errp
);
2817 if (request
->flags
& NBD_CMD_FLAG_FUA
) {
2818 flags
|= BDRV_REQ_FUA
;
2820 assert(request
->len
<= NBD_MAX_BUFFER_SIZE
);
2821 ret
= blk_co_pwrite(exp
->common
.blk
, request
->from
, request
->len
, data
,
2823 return nbd_send_generic_reply(client
, request
, ret
,
2824 "writing to file failed", errp
);
2826 case NBD_CMD_WRITE_ZEROES
:
2828 if (request
->flags
& NBD_CMD_FLAG_FUA
) {
2829 flags
|= BDRV_REQ_FUA
;
2831 if (!(request
->flags
& NBD_CMD_FLAG_NO_HOLE
)) {
2832 flags
|= BDRV_REQ_MAY_UNMAP
;
2834 if (request
->flags
& NBD_CMD_FLAG_FAST_ZERO
) {
2835 flags
|= BDRV_REQ_NO_FALLBACK
;
2837 ret
= blk_co_pwrite_zeroes(exp
->common
.blk
, request
->from
, request
->len
,
2839 return nbd_send_generic_reply(client
, request
, ret
,
2840 "writing to file failed", errp
);
2843 /* unreachable, thanks to special case in nbd_co_receive_request() */
2847 ret
= blk_co_flush(exp
->common
.blk
);
2848 return nbd_send_generic_reply(client
, request
, ret
,
2849 "flush failed", errp
);
2852 ret
= blk_co_pdiscard(exp
->common
.blk
, request
->from
, request
->len
);
2853 if (ret
>= 0 && request
->flags
& NBD_CMD_FLAG_FUA
) {
2854 ret
= blk_co_flush(exp
->common
.blk
);
2856 return nbd_send_generic_reply(client
, request
, ret
,
2857 "discard failed", errp
);
2859 case NBD_CMD_BLOCK_STATUS
:
2860 assert(request
->contexts
);
2861 assert(client
->mode
>= NBD_MODE_EXTENDED
||
2862 request
->len
<= UINT32_MAX
);
2863 if (request
->contexts
->count
) {
2864 bool dont_fragment
= request
->flags
& NBD_CMD_FLAG_REQ_ONE
;
2865 int contexts_remaining
= request
->contexts
->count
;
2867 if (!request
->len
) {
2868 return nbd_send_generic_reply(client
, request
, -EINVAL
,
2869 "need non-zero length", errp
);
2871 if (request
->contexts
->base_allocation
) {
2872 ret
= nbd_co_send_block_status(client
, request
,
2875 request
->len
, dont_fragment
,
2876 !--contexts_remaining
,
2877 NBD_META_ID_BASE_ALLOCATION
,
2884 if (request
->contexts
->allocation_depth
) {
2885 ret
= nbd_co_send_block_status(client
, request
,
2887 request
->from
, request
->len
,
2889 !--contexts_remaining
,
2890 NBD_META_ID_ALLOCATION_DEPTH
,
2897 assert(request
->contexts
->exp
== client
->exp
);
2898 for (i
= 0; i
< client
->exp
->nr_export_bitmaps
; i
++) {
2899 if (!request
->contexts
->bitmaps
[i
]) {
2902 ret
= nbd_co_send_bitmap(client
, request
,
2903 client
->exp
->export_bitmaps
[i
],
2904 request
->from
, request
->len
,
2905 dont_fragment
, !--contexts_remaining
,
2906 NBD_META_ID_DIRTY_BITMAP
+ i
, errp
);
2912 assert(!contexts_remaining
);
2915 } else if (client
->contexts
.count
) {
2916 return nbd_send_generic_reply(client
, request
, -EINVAL
,
2917 "CMD_BLOCK_STATUS payload not valid",
2920 return nbd_send_generic_reply(client
, request
, -EINVAL
,
2921 "CMD_BLOCK_STATUS not negotiated",
2926 msg
= g_strdup_printf("invalid request type (%" PRIu32
") received",
2928 ret
= nbd_send_generic_reply(client
, request
, -EINVAL
, msg
,
2935 /* Owns a reference to the NBDClient passed as opaque. */
2936 static coroutine_fn
void nbd_trip(void *opaque
)
2938 NBDClient
*client
= opaque
;
2939 NBDRequestData
*req
;
2940 NBDRequest request
= { 0 }; /* GCC thinks it can be used uninitialized */
2942 Error
*local_err
= NULL
;
2945 if (client
->closing
) {
2946 nbd_client_put(client
);
2950 if (client
->quiescing
) {
2952 * We're switching between AIO contexts. Don't attempt to receive a new
2953 * request and kick the main context which may be waiting for us.
2955 nbd_client_put(client
);
2956 client
->recv_coroutine
= NULL
;
2961 req
= nbd_request_get(client
);
2962 ret
= nbd_co_receive_request(req
, &request
, &local_err
);
2963 client
->recv_coroutine
= NULL
;
2965 if (client
->closing
) {
2967 * The client may be closed when we are blocked in
2968 * nbd_co_receive_request()
2973 if (ret
== -EAGAIN
) {
2974 assert(client
->quiescing
);
2978 nbd_client_receive_next_request(client
);
2983 qio_channel_set_cork(client
->ioc
, true);
2986 /* It wasn't -EIO, so, according to nbd_co_receive_request()
2987 * semantics, we should return the error to the client. */
2988 Error
*export_err
= local_err
;
2991 ret
= nbd_send_generic_reply(client
, &request
, -EINVAL
,
2992 error_get_pretty(export_err
), &local_err
);
2993 error_free(export_err
);
2995 ret
= nbd_handle_request(client
, &request
, req
->data
, &local_err
);
2997 if (request
.contexts
&& request
.contexts
!= &client
->contexts
) {
2998 assert(request
.type
== NBD_CMD_BLOCK_STATUS
);
2999 g_free(request
.contexts
->bitmaps
);
3000 g_free(request
.contexts
);
3003 error_prepend(&local_err
, "Failed to send reply: ");
3008 * We must disconnect after NBD_CMD_WRITE or BLOCK_STATUS with
3009 * payload if we did not read the payload.
3011 if (!req
->complete
) {
3012 error_setg(&local_err
, "Request handling failed in intermediate state");
3016 qio_channel_set_cork(client
->ioc
, false);
3018 nbd_request_put(req
);
3019 nbd_client_put(client
);
3024 error_reportf_err(local_err
, "Disconnect client, due to: ");
3026 nbd_request_put(req
);
3027 client_close(client
, true);
3028 nbd_client_put(client
);
3031 static void nbd_client_receive_next_request(NBDClient
*client
)
3033 if (!client
->recv_coroutine
&& client
->nb_requests
< MAX_NBD_REQUESTS
&&
3034 !client
->quiescing
) {
3035 nbd_client_get(client
);
3036 client
->recv_coroutine
= qemu_coroutine_create(nbd_trip
, client
);
3037 aio_co_schedule(client
->exp
->common
.ctx
, client
->recv_coroutine
);
3041 static coroutine_fn
void nbd_co_client_start(void *opaque
)
3043 NBDClient
*client
= opaque
;
3044 Error
*local_err
= NULL
;
3046 qemu_co_mutex_init(&client
->send_lock
);
3048 if (nbd_negotiate(client
, &local_err
)) {
3050 error_report_err(local_err
);
3052 client_close(client
, false);
3056 nbd_client_receive_next_request(client
);
3060 * Create a new client listener using the given channel @sioc.
3061 * Begin servicing it in a coroutine. When the connection closes, call
3062 * @close_fn with an indication of whether the client completed negotiation.
3064 void nbd_client_new(QIOChannelSocket
*sioc
,
3065 QCryptoTLSCreds
*tlscreds
,
3066 const char *tlsauthz
,
3067 void (*close_fn
)(NBDClient
*, bool))
3072 client
= g_new0(NBDClient
, 1);
3073 client
->refcount
= 1;
3074 client
->tlscreds
= tlscreds
;
3076 object_ref(OBJECT(client
->tlscreds
));
3078 client
->tlsauthz
= g_strdup(tlsauthz
);
3079 client
->sioc
= sioc
;
3080 qio_channel_set_delay(QIO_CHANNEL(sioc
), false);
3081 object_ref(OBJECT(client
->sioc
));
3082 client
->ioc
= QIO_CHANNEL(sioc
);
3083 object_ref(OBJECT(client
->ioc
));
3084 client
->close_fn
= close_fn
;
3086 co
= qemu_coroutine_create(nbd_co_client_start
, client
);
3087 qemu_coroutine_enter(co
);