2 * Copyright (C) 2016-2021 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"
22 #include "block/export.h"
23 #include "qapi/error.h"
24 #include "qemu/queue.h"
26 #include "nbd-internal.h"
27 #include "qemu/units.h"
28 #include "qemu/memalign.h"
30 #define NBD_META_ID_BASE_ALLOCATION 0
31 #define NBD_META_ID_ALLOCATION_DEPTH 1
32 /* Dirty bitmaps use 'NBD_META_ID_DIRTY_BITMAP + i', so keep this id last. */
33 #define NBD_META_ID_DIRTY_BITMAP 2
36 * NBD_MAX_BLOCK_STATUS_EXTENTS: 1 MiB of extents data. An empirical
37 * constant. If an increase is needed, note that the NBD protocol
38 * recommends no larger than 32 mb, so that the client won't consider
39 * the reply as a denial of service attack.
41 #define NBD_MAX_BLOCK_STATUS_EXTENTS (1 * MiB / 8)
43 static int system_errno_to_nbd_errno(int err)
64 #if ENOTSUP != EOPNOTSUPP
76 /* Definitions for opaque data types */
78 typedef struct NBDRequestData NBDRequestData;
80 struct NBDRequestData {
93 QTAILQ_HEAD(, NBDClient) clients;
94 QTAILQ_ENTRY(NBDExport) next;
96 BlockBackend *eject_notifier_blk;
97 Notifier eject_notifier;
99 bool allocation_depth;
100 BdrvDirtyBitmap **export_bitmaps;
101 size_t nr_export_bitmaps;
104 static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
106 /* NBDExportMetaContexts represents a list of contexts to be exported,
107 * as selected by NBD_OPT_SET_META_CONTEXT. Also used for
108 * NBD_OPT_LIST_META_CONTEXT. */
109 typedef struct NBDExportMetaContexts {
111 size_t count; /* number of negotiated contexts */
112 bool base_allocation; /* export base:allocation context (block status) */
113 bool allocation_depth; /* export qemu:allocation-depth */
115 * export qemu:dirty-bitmap:<export bitmap name>,
116 * sized by exp->nr_export_bitmaps
118 } NBDExportMetaContexts;
122 void (*close_fn)(NBDClient *client, bool negotiated);
125 QCryptoTLSCreds *tlscreds;
127 QIOChannelSocket *sioc; /* The underlying data channel */
128 QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
130 Coroutine *recv_coroutine;
133 Coroutine *send_coroutine;
138 QTAILQ_ENTRY(NBDClient) next;
142 uint32_t check_align; /* If non-zero, check for aligned client requests */
144 bool structured_reply;
145 NBDExportMetaContexts export_meta;
147 uint32_t opt; /* Current option being negotiated */
148 uint32_t optlen; /* remaining length of data in ioc for the option being
152 static void nbd_client_receive_next_request(NBDClient *client);
154 /* Basic flow for negotiation
181 static inline void set_be_option_rep(NBDOptionReply *rep, uint32_t option,
182 uint32_t type, uint32_t length)
184 stq_be_p(&rep->magic, NBD_REP_MAGIC);
185 stl_be_p(&rep->option, option);
186 stl_be_p(&rep->type, type);
187 stl_be_p(&rep->length, length);
190 /* Send a reply header, including length, but no payload.
191 * Return -errno on error, 0 on success. */
192 static int nbd_negotiate_send_rep_len(NBDClient *client, uint32_t type,
193 uint32_t len, Error **errp)
197 trace_nbd_negotiate_send_rep_len(client->opt, nbd_opt_lookup(client->opt),
198 type, nbd_rep_lookup(type), len);
200 assert(len < NBD_MAX_BUFFER_SIZE);
202 set_be_option_rep(&rep, client->opt, type, len);
203 return nbd_write(client->ioc, &rep, sizeof(rep), errp);
206 /* Send a reply header with default 0 length.
207 * Return -errno on error, 0 on success. */
208 static int nbd_negotiate_send_rep(NBDClient *client, uint32_t type,
211 return nbd_negotiate_send_rep_len(client, type, 0, errp);
214 /* Send an error reply.
215 * Return -errno on error, 0 on success. */
216 static int GCC_FMT_ATTR(4, 0)
217 nbd_negotiate_send_rep_verr(NBDClient *client, uint32_t type,
218 Error **errp, const char *fmt, va_list va)
221 g_autofree char *msg = NULL;
225 msg = g_strdup_vprintf(fmt, va);
227 assert(len < NBD_MAX_STRING_SIZE);
228 trace_nbd_negotiate_send_rep_err(msg);
229 ret = nbd_negotiate_send_rep_len(client, type, len, errp);
233 if (nbd_write(client->ioc, msg, len, errp) < 0) {
234 error_prepend(errp, "write failed (error message): ");
242 * Return a malloc'd copy of @name suitable for use in an error reply.
245 nbd_sanitize_name(const char *name)
247 if (strnlen(name, 80) < 80) {
248 return g_strdup(name);
250 /* XXX Should we also try to sanitize any control characters? */
251 return g_strdup_printf("%.80s...", name);
254 /* Send an error reply.
255 * Return -errno on error, 0 on success. */
256 static int GCC_FMT_ATTR(4, 5)
257 nbd_negotiate_send_rep_err(NBDClient *client, uint32_t type,
258 Error **errp, const char *fmt, ...)
264 ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va);
269 /* Drop remainder of the current option, and send a reply with the
270 * given error type and message. Return -errno on read or write
271 * failure; or 0 if connection is still live. */
272 static int GCC_FMT_ATTR(4, 0)
273 nbd_opt_vdrop(NBDClient *client, uint32_t type, Error **errp,
274 const char *fmt, va_list va)
276 int ret = nbd_drop(client->ioc, client->optlen, errp);
280 ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va);
285 static int GCC_FMT_ATTR(4, 5)
286 nbd_opt_drop(NBDClient *client, uint32_t type, Error **errp,
287 const char *fmt, ...)
293 ret = nbd_opt_vdrop(client, type, errp, fmt, va);
299 static int GCC_FMT_ATTR(3, 4)
300 nbd_opt_invalid(NBDClient *client, Error **errp, const char *fmt, ...)
306 ret = nbd_opt_vdrop(client, NBD_REP_ERR_INVALID, errp, fmt, va);
312 /* Read size bytes from the unparsed payload of the current option.
313 * If @check_nul, require that no NUL bytes appear in buffer.
314 * Return -errno on I/O error, 0 if option was completely handled by
315 * sending a reply about inconsistent lengths, or 1 on success. */
316 static int nbd_opt_read(NBDClient *client, void *buffer, size_t size,
317 bool check_nul, Error **errp)
319 if (size > client->optlen) {
320 return nbd_opt_invalid(client, errp,
321 "Inconsistent lengths in option %s",
322 nbd_opt_lookup(client->opt));
324 client->optlen -= size;
325 if (qio_channel_read_all(client->ioc, buffer, size, errp) < 0) {
329 if (check_nul && strnlen(buffer, size) != size) {
330 return nbd_opt_invalid(client, errp,
331 "Unexpected embedded NUL in option %s",
332 nbd_opt_lookup(client->opt));
337 /* Drop size bytes from the unparsed payload of the current option.
338 * Return -errno on I/O error, 0 if option was completely handled by
339 * sending a reply about inconsistent lengths, or 1 on success. */
340 static int nbd_opt_skip(NBDClient *client, size_t size, Error **errp)
342 if (size > client->optlen) {
343 return nbd_opt_invalid(client, errp,
344 "Inconsistent lengths in option %s",
345 nbd_opt_lookup(client->opt));
347 client->optlen -= size;
348 return nbd_drop(client->ioc, size, errp) < 0 ? -EIO : 1;
353 * Read a string with the format:
354 * uint32_t len (<= NBD_MAX_STRING_SIZE)
355 * len bytes string (not 0-terminated)
357 * On success, @name will be allocated.
358 * If @length is non-null, it will be set to the actual string length.
360 * Return -errno on I/O error, 0 if option was completely handled by
361 * sending a reply about inconsistent lengths, or 1 on success.
363 static int nbd_opt_read_name(NBDClient *client, char **name, uint32_t *length,
368 g_autofree char *local_name = NULL;
371 ret = nbd_opt_read(client, &len, sizeof(len), false, errp);
375 len = cpu_to_be32(len);
377 if (len > NBD_MAX_STRING_SIZE) {
378 return nbd_opt_invalid(client, errp,
379 "Invalid name length: %" PRIu32, len);
382 local_name = g_malloc(len + 1);
383 ret = nbd_opt_read(client, local_name, len, true, errp);
387 local_name[len] = '\0';
392 *name = g_steal_pointer(&local_name);
397 /* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload.
398 * Return -errno on error, 0 on success. */
399 static int nbd_negotiate_send_rep_list(NBDClient *client, NBDExport *exp,
403 size_t name_len, desc_len;
405 const char *name = exp->name ? exp->name : "";
406 const char *desc = exp->description ? exp->description : "";
407 QIOChannel *ioc = client->ioc;
410 trace_nbd_negotiate_send_rep_list(name, desc);
411 name_len = strlen(name);
412 desc_len = strlen(desc);
413 assert(name_len <= NBD_MAX_STRING_SIZE && desc_len <= NBD_MAX_STRING_SIZE);
414 len = name_len + desc_len + sizeof(len);
415 ret = nbd_negotiate_send_rep_len(client, NBD_REP_SERVER, len, errp);
420 len = cpu_to_be32(name_len);
421 if (nbd_write(ioc, &len, sizeof(len), errp) < 0) {
422 error_prepend(errp, "write failed (name length): ");
426 if (nbd_write(ioc, name, name_len, errp) < 0) {
427 error_prepend(errp, "write failed (name buffer): ");
431 if (nbd_write(ioc, desc, desc_len, errp) < 0) {
432 error_prepend(errp, "write failed (description buffer): ");
439 /* Process the NBD_OPT_LIST command, with a potential series of replies.
440 * Return -errno on error, 0 on success. */
441 static int nbd_negotiate_handle_list(NBDClient *client, Error **errp)
444 assert(client->opt == NBD_OPT_LIST);
446 /* For each export, send a NBD_REP_SERVER reply. */
447 QTAILQ_FOREACH(exp, &exports, next) {
448 if (nbd_negotiate_send_rep_list(client, exp, errp)) {
452 /* Finish with a NBD_REP_ACK. */
453 return nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
456 static void nbd_check_meta_export(NBDClient *client)
458 if (client->exp != client->export_meta.exp) {
459 client->export_meta.count = 0;
463 /* Send a reply to NBD_OPT_EXPORT_NAME.
464 * Return -errno on error, 0 on success. */
465 static int nbd_negotiate_handle_export_name(NBDClient *client, bool no_zeroes,
469 g_autofree char *name = NULL;
470 char buf[NBD_REPLY_EXPORT_NAME_SIZE] = "";
476 [20 .. xx] export name (length bytes)
479 [ 8 .. 9] export flags
480 [10 .. 133] reserved (0) [unless no_zeroes]
482 trace_nbd_negotiate_handle_export_name();
483 if (client->optlen > NBD_MAX_STRING_SIZE) {
484 error_setg(errp, "Bad length received");
487 name = g_malloc(client->optlen + 1);
488 if (nbd_read(client->ioc, name, client->optlen, "export name", errp) < 0) {
491 name[client->optlen] = '\0';
494 trace_nbd_negotiate_handle_export_name_request(name);
496 client->exp = nbd_export_find(name);
498 error_setg(errp, "export not found");
502 myflags = client->exp->nbdflags;
503 if (client->structured_reply) {
504 myflags |= NBD_FLAG_SEND_DF;
506 trace_nbd_negotiate_new_style_size_flags(client->exp->size, myflags);
507 stq_be_p(buf, client->exp->size);
508 stw_be_p(buf + 8, myflags);
509 len = no_zeroes ? 10 : sizeof(buf);
510 ret = nbd_write(client->ioc, buf, len, errp);
512 error_prepend(errp, "write failed: ");
516 QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
517 blk_exp_ref(&client->exp->common);
518 nbd_check_meta_export(client);
523 /* Send a single NBD_REP_INFO, with a buffer @buf of @length bytes.
524 * The buffer does NOT include the info type prefix.
525 * Return -errno on error, 0 if ready to send more. */
526 static int nbd_negotiate_send_info(NBDClient *client,
527 uint16_t info, uint32_t length, void *buf,
532 trace_nbd_negotiate_send_info(info, nbd_info_lookup(info), length);
533 rc = nbd_negotiate_send_rep_len(client, NBD_REP_INFO,
534 sizeof(info) + length, errp);
538 info = cpu_to_be16(info);
539 if (nbd_write(client->ioc, &info, sizeof(info), errp) < 0) {
542 if (nbd_write(client->ioc, buf, length, errp) < 0) {
548 /* nbd_reject_length: Handle any unexpected payload.
549 * @fatal requests that we quit talking to the client, even if we are able
550 * to successfully send an error reply.
552 * -errno transmission error occurred or @fatal was requested, errp is set
553 * 0 error message successfully sent to client, errp is not set
555 static int nbd_reject_length(NBDClient *client, bool fatal, Error **errp)
559 assert(client->optlen);
560 ret = nbd_opt_invalid(client, errp, "option '%s' has unexpected length",
561 nbd_opt_lookup(client->opt));
563 error_setg(errp, "option '%s' has unexpected length",
564 nbd_opt_lookup(client->opt));
570 /* Handle NBD_OPT_INFO and NBD_OPT_GO.
571 * Return -errno on error, 0 if ready for next option, and 1 to move
572 * into transmission phase. */
573 static int nbd_negotiate_handle_info(NBDClient *client, Error **errp)
576 g_autofree char *name = NULL;
580 uint32_t namelen = 0;
581 bool sendname = false;
582 bool blocksize = false;
584 char buf[sizeof(uint64_t) + sizeof(uint16_t)];
585 uint32_t check_align = 0;
589 4 bytes: L, name length (can be 0)
591 2 bytes: N, number of requests (can be 0)
592 N * 2 bytes: N requests
594 rc = nbd_opt_read_name(client, &name, &namelen, errp);
598 trace_nbd_negotiate_handle_export_name_request(name);
600 rc = nbd_opt_read(client, &requests, sizeof(requests), false, errp);
604 requests = be16_to_cpu(requests);
605 trace_nbd_negotiate_handle_info_requests(requests);
607 rc = nbd_opt_read(client, &request, sizeof(request), false, errp);
611 request = be16_to_cpu(request);
612 trace_nbd_negotiate_handle_info_request(request,
613 nbd_info_lookup(request));
614 /* We care about NBD_INFO_NAME and NBD_INFO_BLOCK_SIZE;
615 * everything else is either a request we don't know or
616 * something we send regardless of request */
621 case NBD_INFO_BLOCK_SIZE:
626 if (client->optlen) {
627 return nbd_reject_length(client, false, errp);
630 exp = nbd_export_find(name);
632 g_autofree char *sane_name = nbd_sanitize_name(name);
634 return nbd_negotiate_send_rep_err(client, NBD_REP_ERR_UNKNOWN,
635 errp, "export '%s' not present",
639 /* Don't bother sending NBD_INFO_NAME unless client requested it */
641 rc = nbd_negotiate_send_info(client, NBD_INFO_NAME, namelen, name,
648 /* Send NBD_INFO_DESCRIPTION only if available, regardless of
650 if (exp->description) {
651 size_t len = strlen(exp->description);
653 assert(len <= NBD_MAX_STRING_SIZE);
654 rc = nbd_negotiate_send_info(client, NBD_INFO_DESCRIPTION,
655 len, exp->description, errp);
661 /* Send NBD_INFO_BLOCK_SIZE always, but tweak the minimum size
662 * according to whether the client requested it, and according to
663 * whether this is OPT_INFO or OPT_GO. */
664 /* minimum - 1 for back-compat, or actual if client will obey it. */
665 if (client->opt == NBD_OPT_INFO || blocksize) {
666 check_align = sizes[0] = blk_get_request_alignment(exp->common.blk);
670 assert(sizes[0] <= NBD_MAX_BUFFER_SIZE);
671 /* preferred - Hard-code to 4096 for now.
672 * TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */
673 sizes[1] = MAX(4096, sizes[0]);
674 /* maximum - At most 32M, but smaller as appropriate. */
675 sizes[2] = MIN(blk_get_max_transfer(exp->common.blk), NBD_MAX_BUFFER_SIZE);
676 trace_nbd_negotiate_handle_info_block_size(sizes[0], sizes[1], sizes[2]);
677 sizes[0] = cpu_to_be32(sizes[0]);
678 sizes[1] = cpu_to_be32(sizes[1]);
679 sizes[2] = cpu_to_be32(sizes[2]);
680 rc = nbd_negotiate_send_info(client, NBD_INFO_BLOCK_SIZE,
681 sizeof(sizes), sizes, errp);
686 /* Send NBD_INFO_EXPORT always */
687 myflags = exp->nbdflags;
688 if (client->structured_reply) {
689 myflags |= NBD_FLAG_SEND_DF;
691 trace_nbd_negotiate_new_style_size_flags(exp->size, myflags);
692 stq_be_p(buf, exp->size);
693 stw_be_p(buf + 8, myflags);
694 rc = nbd_negotiate_send_info(client, NBD_INFO_EXPORT,
695 sizeof(buf), buf, errp);
701 * If the client is just asking for NBD_OPT_INFO, but forgot to
702 * request block sizes in a situation that would impact
703 * performance, then return an error. But for NBD_OPT_GO, we
704 * tolerate all clients, regardless of alignments.
706 if (client->opt == NBD_OPT_INFO && !blocksize &&
707 blk_get_request_alignment(exp->common.blk) > 1) {
708 return nbd_negotiate_send_rep_err(client,
709 NBD_REP_ERR_BLOCK_SIZE_REQD,
711 "request NBD_INFO_BLOCK_SIZE to "
716 rc = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
721 if (client->opt == NBD_OPT_GO) {
723 client->check_align = check_align;
724 QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
725 blk_exp_ref(&client->exp->common);
726 nbd_check_meta_export(client);
733 /* Handle NBD_OPT_STARTTLS. Return NULL to drop connection, or else the
734 * new channel for all further (now-encrypted) communication. */
735 static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client,
740 struct NBDTLSHandshakeData data = { 0 };
742 assert(client->opt == NBD_OPT_STARTTLS);
744 trace_nbd_negotiate_handle_starttls();
747 if (nbd_negotiate_send_rep(client, NBD_REP_ACK, errp) < 0) {
751 tioc = qio_channel_tls_new_server(ioc,
759 qio_channel_set_name(QIO_CHANNEL(tioc), "nbd-server-tls");
760 trace_nbd_negotiate_handle_starttls_handshake();
761 data.loop = g_main_loop_new(g_main_context_default(), FALSE);
762 qio_channel_tls_handshake(tioc,
768 if (!data.complete) {
769 g_main_loop_run(data.loop);
771 g_main_loop_unref(data.loop);
773 object_unref(OBJECT(tioc));
774 error_propagate(errp, data.error);
778 return QIO_CHANNEL(tioc);
781 /* nbd_negotiate_send_meta_context
783 * Send one chunk of reply to NBD_OPT_{LIST,SET}_META_CONTEXT
785 * For NBD_OPT_LIST_META_CONTEXT @context_id is ignored, 0 is used instead.
787 static int nbd_negotiate_send_meta_context(NBDClient *client,
792 NBDOptionReplyMetaContext opt;
793 struct iovec iov[] = {
794 {.iov_base = &opt, .iov_len = sizeof(opt)},
795 {.iov_base = (void *)context, .iov_len = strlen(context)}
798 assert(iov[1].iov_len <= NBD_MAX_STRING_SIZE);
799 if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
803 trace_nbd_negotiate_meta_query_reply(context, context_id);
804 set_be_option_rep(&opt.h, client->opt, NBD_REP_META_CONTEXT,
805 sizeof(opt) - sizeof(opt.h) + iov[1].iov_len);
806 stl_be_p(&opt.context_id, context_id);
808 return qio_channel_writev_all(client->ioc, iov, 2, errp) < 0 ? -EIO : 0;
812 * Return true if @query matches @pattern, or if @query is empty when
813 * the @client is performing _LIST_.
815 static bool nbd_meta_empty_or_pattern(NBDClient *client, const char *pattern,
819 trace_nbd_negotiate_meta_query_parse("empty");
820 return client->opt == NBD_OPT_LIST_META_CONTEXT;
822 if (strcmp(query, pattern) == 0) {
823 trace_nbd_negotiate_meta_query_parse(pattern);
826 trace_nbd_negotiate_meta_query_skip("pattern not matched");
831 * Return true and adjust @str in place if it begins with @prefix.
833 static bool nbd_strshift(const char **str, const char *prefix)
835 size_t len = strlen(prefix);
837 if (strncmp(*str, prefix, len) == 0) {
844 /* nbd_meta_base_query
846 * Handle queries to 'base' namespace. For now, only the base:allocation
847 * context is available. Return true if @query has been handled.
849 static bool nbd_meta_base_query(NBDClient *client, NBDExportMetaContexts *meta,
852 if (!nbd_strshift(&query, "base:")) {
855 trace_nbd_negotiate_meta_query_parse("base:");
857 if (nbd_meta_empty_or_pattern(client, "allocation", query)) {
858 meta->base_allocation = true;
863 /* nbd_meta_qemu_query
865 * Handle queries to 'qemu' namespace. For now, only the qemu:dirty-bitmap:
866 * and qemu:allocation-depth contexts are available. Return true if @query
869 static bool nbd_meta_qemu_query(NBDClient *client, NBDExportMetaContexts *meta,
874 if (!nbd_strshift(&query, "qemu:")) {
877 trace_nbd_negotiate_meta_query_parse("qemu:");
880 if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
881 meta->allocation_depth = meta->exp->allocation_depth;
882 if (meta->exp->nr_export_bitmaps) {
883 memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps);
886 trace_nbd_negotiate_meta_query_parse("empty");
890 if (strcmp(query, "allocation-depth") == 0) {
891 trace_nbd_negotiate_meta_query_parse("allocation-depth");
892 meta->allocation_depth = meta->exp->allocation_depth;
896 if (nbd_strshift(&query, "dirty-bitmap:")) {
897 trace_nbd_negotiate_meta_query_parse("dirty-bitmap:");
899 if (client->opt == NBD_OPT_LIST_META_CONTEXT &&
900 meta->exp->nr_export_bitmaps) {
901 memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps);
903 trace_nbd_negotiate_meta_query_parse("empty");
907 for (i = 0; i < meta->exp->nr_export_bitmaps; i++) {
910 bm_name = bdrv_dirty_bitmap_name(meta->exp->export_bitmaps[i]);
911 if (strcmp(bm_name, query) == 0) {
912 meta->bitmaps[i] = true;
913 trace_nbd_negotiate_meta_query_parse(query);
917 trace_nbd_negotiate_meta_query_skip("no dirty-bitmap match");
921 trace_nbd_negotiate_meta_query_skip("unknown qemu context");
925 /* nbd_negotiate_meta_query
927 * Parse namespace name and call corresponding function to parse body of the
930 * The only supported namespaces are 'base' and 'qemu'.
932 * Return -errno on I/O error, 0 if option was completely handled by
933 * sending a reply about inconsistent lengths, or 1 on success. */
934 static int nbd_negotiate_meta_query(NBDClient *client,
935 NBDExportMetaContexts *meta, Error **errp)
938 g_autofree char *query = NULL;
941 ret = nbd_opt_read(client, &len, sizeof(len), false, errp);
945 len = cpu_to_be32(len);
947 if (len > NBD_MAX_STRING_SIZE) {
948 trace_nbd_negotiate_meta_query_skip("length too long");
949 return nbd_opt_skip(client, len, errp);
952 query = g_malloc(len + 1);
953 ret = nbd_opt_read(client, query, len, true, errp);
959 if (nbd_meta_base_query(client, meta, query)) {
962 if (nbd_meta_qemu_query(client, meta, query)) {
966 trace_nbd_negotiate_meta_query_skip("unknown namespace");
970 /* nbd_negotiate_meta_queries
971 * Handle NBD_OPT_LIST_META_CONTEXT and NBD_OPT_SET_META_CONTEXT
973 * Return -errno on I/O error, or 0 if option was completely handled. */
974 static int nbd_negotiate_meta_queries(NBDClient *client,
975 NBDExportMetaContexts *meta, Error **errp)
978 g_autofree char *export_name = NULL;
979 /* Mark unused to work around https://bugs.llvm.org/show_bug.cgi?id=3888 */
980 g_autofree G_GNUC_UNUSED bool *bitmaps = NULL;
981 NBDExportMetaContexts local_meta = {0};
986 if (client->opt == NBD_OPT_SET_META_CONTEXT && !client->structured_reply) {
987 return nbd_opt_invalid(client, errp,
988 "request option '%s' when structured reply "
990 nbd_opt_lookup(client->opt));
993 if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
994 /* Only change the caller's meta on SET. */
998 g_free(meta->bitmaps);
999 memset(meta, 0, sizeof(*meta));
1001 ret = nbd_opt_read_name(client, &export_name, NULL, errp);
1006 meta->exp = nbd_export_find(export_name);
1007 if (meta->exp == NULL) {
1008 g_autofree char *sane_name = nbd_sanitize_name(export_name);
1010 return nbd_opt_drop(client, NBD_REP_ERR_UNKNOWN, errp,
1011 "export '%s' not present", sane_name);
1013 meta->bitmaps = g_new0(bool, meta->exp->nr_export_bitmaps);
1014 if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
1015 bitmaps = meta->bitmaps;
1018 ret = nbd_opt_read(client, &nb_queries, sizeof(nb_queries), false, errp);
1022 nb_queries = cpu_to_be32(nb_queries);
1023 trace_nbd_negotiate_meta_context(nbd_opt_lookup(client->opt),
1024 export_name, nb_queries);
1026 if (client->opt == NBD_OPT_LIST_META_CONTEXT && !nb_queries) {
1027 /* enable all known contexts */
1028 meta->base_allocation = true;
1029 meta->allocation_depth = meta->exp->allocation_depth;
1030 if (meta->exp->nr_export_bitmaps) {
1031 memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps);
1034 for (i = 0; i < nb_queries; ++i) {
1035 ret = nbd_negotiate_meta_query(client, meta, errp);
1042 if (meta->base_allocation) {
1043 ret = nbd_negotiate_send_meta_context(client, "base:allocation",
1044 NBD_META_ID_BASE_ALLOCATION,
1052 if (meta->allocation_depth) {
1053 ret = nbd_negotiate_send_meta_context(client, "qemu:allocation-depth",
1054 NBD_META_ID_ALLOCATION_DEPTH,
1062 for (i = 0; i < meta->exp->nr_export_bitmaps; i++) {
1063 const char *bm_name;
1064 g_autofree char *context = NULL;
1066 if (!meta->bitmaps[i]) {
1070 bm_name = bdrv_dirty_bitmap_name(meta->exp->export_bitmaps[i]);
1071 context = g_strdup_printf("qemu:dirty-bitmap:%s", bm_name);
1073 ret = nbd_negotiate_send_meta_context(client, context,
1074 NBD_META_ID_DIRTY_BITMAP + i,
1082 ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
1084 meta->count = count;
1090 /* nbd_negotiate_options
1091 * Process all NBD_OPT_* client option commands, during fixed newstyle
1094 * -errno on error, errp is set
1095 * 0 on successful negotiation, errp is not set
1096 * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
1099 static int nbd_negotiate_options(NBDClient *client, Error **errp)
1102 bool fixedNewstyle = false;
1103 bool no_zeroes = false;
1106 [ 0 .. 3] client flags
1108 Then we loop until NBD_OPT_EXPORT_NAME or NBD_OPT_GO:
1109 [ 0 .. 7] NBD_OPTS_MAGIC
1110 [ 8 .. 11] NBD option
1111 [12 .. 15] Data length
1114 [ 0 .. 7] NBD_OPTS_MAGIC
1115 [ 8 .. 11] Second NBD option
1116 [12 .. 15] Data length
1120 if (nbd_read32(client->ioc, &flags, "flags", errp) < 0) {
1123 trace_nbd_negotiate_options_flags(flags);
1124 if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) {
1125 fixedNewstyle = true;
1126 flags &= ~NBD_FLAG_C_FIXED_NEWSTYLE;
1128 if (flags & NBD_FLAG_C_NO_ZEROES) {
1130 flags &= ~NBD_FLAG_C_NO_ZEROES;
1133 error_setg(errp, "Unknown client flags 0x%" PRIx32 " received", flags);
1139 uint32_t option, length;
1142 if (nbd_read64(client->ioc, &magic, "opts magic", errp) < 0) {
1145 trace_nbd_negotiate_options_check_magic(magic);
1146 if (magic != NBD_OPTS_MAGIC) {
1147 error_setg(errp, "Bad magic received");
1151 if (nbd_read32(client->ioc, &option, "option", errp) < 0) {
1154 client->opt = option;
1156 if (nbd_read32(client->ioc, &length, "option length", errp) < 0) {
1159 assert(!client->optlen);
1160 client->optlen = length;
1162 if (length > NBD_MAX_BUFFER_SIZE) {
1163 error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)",
1164 length, NBD_MAX_BUFFER_SIZE);
1168 trace_nbd_negotiate_options_check_option(option,
1169 nbd_opt_lookup(option));
1170 if (client->tlscreds &&
1171 client->ioc == (QIOChannel *)client->sioc) {
1173 if (!fixedNewstyle) {
1174 error_setg(errp, "Unsupported option 0x%" PRIx32, option);
1178 case NBD_OPT_STARTTLS:
1180 /* Unconditionally drop the connection if the client
1181 * can't start a TLS negotiation correctly */
1182 return nbd_reject_length(client, true, errp);
1184 tioc = nbd_negotiate_handle_starttls(client, errp);
1189 object_unref(OBJECT(client->ioc));
1190 client->ioc = QIO_CHANNEL(tioc);
1193 case NBD_OPT_EXPORT_NAME:
1194 /* No way to return an error to client, so drop connection */
1195 error_setg(errp, "Option 0x%x not permitted before TLS",
1200 /* Let the client keep trying, unless they asked to
1201 * quit. Always try to give an error back to the
1202 * client; but when replying to OPT_ABORT, be aware
1203 * that the client may hang up before receiving the
1204 * error, in which case we are fine ignoring the
1205 * resulting EPIPE. */
1206 ret = nbd_opt_drop(client, NBD_REP_ERR_TLS_REQD,
1207 option == NBD_OPT_ABORT ? NULL : errp,
1209 " not permitted before TLS", option);
1210 if (option == NBD_OPT_ABORT) {
1215 } else if (fixedNewstyle) {
1219 ret = nbd_reject_length(client, false, errp);
1221 ret = nbd_negotiate_handle_list(client, errp);
1226 /* NBD spec says we must try to reply before
1227 * disconnecting, but that we must also tolerate
1228 * guests that don't wait for our reply. */
1229 nbd_negotiate_send_rep(client, NBD_REP_ACK, NULL);
1232 case NBD_OPT_EXPORT_NAME:
1233 return nbd_negotiate_handle_export_name(client, no_zeroes,
1238 ret = nbd_negotiate_handle_info(client, errp);
1240 assert(option == NBD_OPT_GO);
1245 case NBD_OPT_STARTTLS:
1247 ret = nbd_reject_length(client, false, errp);
1248 } else if (client->tlscreds) {
1249 ret = nbd_negotiate_send_rep_err(client,
1250 NBD_REP_ERR_INVALID, errp,
1251 "TLS already enabled");
1253 ret = nbd_negotiate_send_rep_err(client,
1254 NBD_REP_ERR_POLICY, errp,
1255 "TLS not configured");
1259 case NBD_OPT_STRUCTURED_REPLY:
1261 ret = nbd_reject_length(client, false, errp);
1262 } else if (client->structured_reply) {
1263 ret = nbd_negotiate_send_rep_err(
1264 client, NBD_REP_ERR_INVALID, errp,
1265 "structured reply already negotiated");
1267 ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
1268 client->structured_reply = true;
1272 case NBD_OPT_LIST_META_CONTEXT:
1273 case NBD_OPT_SET_META_CONTEXT:
1274 ret = nbd_negotiate_meta_queries(client, &client->export_meta,
1279 ret = nbd_opt_drop(client, NBD_REP_ERR_UNSUP, errp,
1280 "Unsupported option %" PRIu32 " (%s)",
1281 option, nbd_opt_lookup(option));
1286 * If broken new-style we should drop the connection
1287 * for anything except NBD_OPT_EXPORT_NAME
1290 case NBD_OPT_EXPORT_NAME:
1291 return nbd_negotiate_handle_export_name(client, no_zeroes,
1295 error_setg(errp, "Unsupported option %" PRIu32 " (%s)",
1296 option, nbd_opt_lookup(option));
1308 * -errno on error, errp is set
1309 * 0 on successful negotiation, errp is not set
1310 * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
1313 static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp)
1316 char buf[NBD_OLDSTYLE_NEGOTIATE_SIZE] = "";
1319 /* Old style negotiation header, no room for options
1320 [ 0 .. 7] passwd ("NBDMAGIC")
1321 [ 8 .. 15] magic (NBD_CLIENT_MAGIC)
1323 [24 .. 27] export flags (zero-extended)
1324 [28 .. 151] reserved (0)
1326 New style negotiation header, client can send options
1327 [ 0 .. 7] passwd ("NBDMAGIC")
1328 [ 8 .. 15] magic (NBD_OPTS_MAGIC)
1329 [16 .. 17] server flags (0)
1330 ....options sent, ending in NBD_OPT_EXPORT_NAME or NBD_OPT_GO....
1333 qio_channel_set_blocking(client->ioc, false, NULL);
1335 trace_nbd_negotiate_begin();
1336 memcpy(buf, "NBDMAGIC", 8);
1338 stq_be_p(buf + 8, NBD_OPTS_MAGIC);
1339 stw_be_p(buf + 16, NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES);
1341 if (nbd_write(client->ioc, buf, 18, errp) < 0) {
1342 error_prepend(errp, "write failed: ");
1345 ret = nbd_negotiate_options(client, errp);
1348 error_prepend(errp, "option negotiation failed: ");
1353 /* Attach the channel to the same AioContext as the export */
1354 if (client->exp && client->exp->common.ctx) {
1355 qio_channel_attach_aio_context(client->ioc, client->exp->common.ctx);
1358 assert(!client->optlen);
1359 trace_nbd_negotiate_success();
1365 * Tries to read @size bytes from @ioc. This is a local implementation of
1366 * qio_channel_readv_all_eof. We have it here because we need it to be
1367 * interruptible and to know when the coroutine is yielding.
1368 * Returns 1 on success
1369 * 0 on eof, when no data was read (errp is not set)
1370 * negative errno on failure (errp is set)
1372 static inline int coroutine_fn
1373 nbd_read_eof(NBDClient *client, void *buffer, size_t size, Error **errp)
1375 bool partial = false;
1379 struct iovec iov = { .iov_base = buffer, .iov_len = size };
1382 len = qio_channel_readv(client->ioc, &iov, 1, errp);
1383 if (len == QIO_CHANNEL_ERR_BLOCK) {
1384 client->read_yielding = true;
1385 qio_channel_yield(client->ioc, G_IO_IN);
1386 client->read_yielding = false;
1387 if (client->quiescing) {
1391 } else if (len < 0) {
1393 } else if (len == 0) {
1396 "Unexpected end-of-file before all bytes were read");
1405 buffer = (uint8_t *) buffer + len;
1410 static int nbd_receive_request(NBDClient *client, NBDRequest *request,
1413 uint8_t buf[NBD_REQUEST_SIZE];
1417 ret = nbd_read_eof(client, buf, sizeof(buf), errp);
1426 [ 0 .. 3] magic (NBD_REQUEST_MAGIC)
1427 [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...)
1428 [ 6 .. 7] type (NBD_CMD_READ, ...)
1434 magic = ldl_be_p(buf);
1435 request->flags = lduw_be_p(buf + 4);
1436 request->type = lduw_be_p(buf + 6);
1437 request->handle = ldq_be_p(buf + 8);
1438 request->from = ldq_be_p(buf + 16);
1439 request->len = ldl_be_p(buf + 24);
1441 trace_nbd_receive_request(magic, request->flags, request->type,
1442 request->from, request->len);
1444 if (magic != NBD_REQUEST_MAGIC) {
1445 error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", magic);
1451 #define MAX_NBD_REQUESTS 16
1453 void nbd_client_get(NBDClient *client)
1458 void nbd_client_put(NBDClient *client)
1460 if (--client->refcount == 0) {
1461 /* The last reference should be dropped by client->close,
1462 * which is called by client_close.
1464 assert(client->closing);
1466 qio_channel_detach_aio_context(client->ioc);
1467 object_unref(OBJECT(client->sioc));
1468 object_unref(OBJECT(client->ioc));
1469 if (client->tlscreds) {
1470 object_unref(OBJECT(client->tlscreds));
1472 g_free(client->tlsauthz);
1474 QTAILQ_REMOVE(&client->exp->clients, client, next);
1475 blk_exp_unref(&client->exp->common);
1477 g_free(client->export_meta.bitmaps);
1482 static void client_close(NBDClient *client, bool negotiated)
1484 if (client->closing) {
1488 client->closing = true;
1490 /* Force requests to finish. They will drop their own references,
1491 * then we'll close the socket and free the NBDClient.
1493 qio_channel_shutdown(client->ioc, QIO_CHANNEL_SHUTDOWN_BOTH,
1496 /* Also tell the client, so that they release their reference. */
1497 if (client->close_fn) {
1498 client->close_fn(client, negotiated);
1502 static NBDRequestData *nbd_request_get(NBDClient *client)
1504 NBDRequestData *req;
1506 assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
1507 client->nb_requests++;
1509 req = g_new0(NBDRequestData, 1);
1510 nbd_client_get(client);
1511 req->client = client;
1515 static void nbd_request_put(NBDRequestData *req)
1517 NBDClient *client = req->client;
1520 qemu_vfree(req->data);
1524 client->nb_requests--;
1526 if (client->quiescing && client->nb_requests == 0) {
1530 nbd_client_receive_next_request(client);
1532 nbd_client_put(client);
1535 static void blk_aio_attached(AioContext *ctx, void *opaque)
1537 NBDExport *exp = opaque;
1540 trace_nbd_blk_aio_attached(exp->name, ctx);
1542 exp->common.ctx = ctx;
1544 QTAILQ_FOREACH(client, &exp->clients, next) {
1545 qio_channel_attach_aio_context(client->ioc, ctx);
1547 assert(client->nb_requests == 0);
1548 assert(client->recv_coroutine == NULL);
1549 assert(client->send_coroutine == NULL);
1553 static void blk_aio_detach(void *opaque)
1555 NBDExport *exp = opaque;
1558 trace_nbd_blk_aio_detach(exp->name, exp->common.ctx);
1560 QTAILQ_FOREACH(client, &exp->clients, next) {
1561 qio_channel_detach_aio_context(client->ioc);
1564 exp->common.ctx = NULL;
1567 static void nbd_drained_begin(void *opaque)
1569 NBDExport *exp = opaque;
1572 QTAILQ_FOREACH(client, &exp->clients, next) {
1573 client->quiescing = true;
1577 static void nbd_drained_end(void *opaque)
1579 NBDExport *exp = opaque;
1582 QTAILQ_FOREACH(client, &exp->clients, next) {
1583 client->quiescing = false;
1584 nbd_client_receive_next_request(client);
1588 static bool nbd_drained_poll(void *opaque)
1590 NBDExport *exp = opaque;
1593 QTAILQ_FOREACH(client, &exp->clients, next) {
1594 if (client->nb_requests != 0) {
1596 * If there's a coroutine waiting for a request on nbd_read_eof()
1597 * enter it here so we don't depend on the client to wake it up.
1599 if (client->recv_coroutine != NULL && client->read_yielding) {
1600 qemu_aio_coroutine_enter(exp->common.ctx,
1601 client->recv_coroutine);
1611 static void nbd_eject_notifier(Notifier *n, void *data)
1613 NBDExport *exp = container_of(n, NBDExport, eject_notifier);
1615 blk_exp_request_shutdown(&exp->common);
1618 void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk)
1620 NBDExport *nbd_exp = container_of(exp, NBDExport, common);
1621 assert(exp->drv == &blk_exp_nbd);
1622 assert(nbd_exp->eject_notifier_blk == NULL);
1625 nbd_exp->eject_notifier_blk = blk;
1626 nbd_exp->eject_notifier.notify = nbd_eject_notifier;
1627 blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier);
1630 static const BlockDevOps nbd_block_ops = {
1631 .drained_begin = nbd_drained_begin,
1632 .drained_end = nbd_drained_end,
1633 .drained_poll = nbd_drained_poll,
1636 static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args,
1639 NBDExport *exp = container_of(blk_exp, NBDExport, common);
1640 BlockExportOptionsNbd *arg = &exp_args->u.nbd;
1641 BlockBackend *blk = blk_exp->blk;
1643 uint64_t perm, shared_perm;
1644 bool readonly = !exp_args->writable;
1645 bool shared = !exp_args->writable;
1650 assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD);
1652 if (!nbd_server_is_running()) {
1653 error_setg(errp, "NBD server not running");
1657 if (!arg->has_name) {
1658 arg->name = exp_args->node_name;
1661 if (strlen(arg->name) > NBD_MAX_STRING_SIZE) {
1662 error_setg(errp, "export name '%s' too long", arg->name);
1666 if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) {
1667 error_setg(errp, "description '%s' too long", arg->description);
1671 if (nbd_export_find(arg->name)) {
1672 error_setg(errp, "NBD server already has export named '%s'", arg->name);
1676 size = blk_getlength(blk);
1678 error_setg_errno(errp, -size,
1679 "Failed to determine the NBD export's length");
1683 /* Don't allow resize while the NBD server is running, otherwise we don't
1684 * care what happens with the node. */
1685 blk_get_perm(blk, &perm, &shared_perm);
1686 ret = blk_set_perm(blk, perm, shared_perm & ~BLK_PERM_RESIZE, errp);
1691 QTAILQ_INIT(&exp->clients);
1692 exp->name = g_strdup(arg->name);
1693 exp->description = g_strdup(arg->description);
1694 exp->nbdflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_FLUSH |
1695 NBD_FLAG_SEND_FUA | NBD_FLAG_SEND_CACHE);
1697 exp->nbdflags |= NBD_FLAG_READ_ONLY;
1699 exp->nbdflags |= NBD_FLAG_CAN_MULTI_CONN;
1702 exp->nbdflags |= (NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_WRITE_ZEROES |
1703 NBD_FLAG_SEND_FAST_ZERO);
1705 exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE);
1707 for (bitmaps = arg->bitmaps; bitmaps; bitmaps = bitmaps->next) {
1708 exp->nr_export_bitmaps++;
1710 exp->export_bitmaps = g_new0(BdrvDirtyBitmap *, exp->nr_export_bitmaps);
1711 for (i = 0, bitmaps = arg->bitmaps; bitmaps;
1712 i++, bitmaps = bitmaps->next) {
1713 const char *bitmap = bitmaps->value;
1714 BlockDriverState *bs = blk_bs(blk);
1715 BdrvDirtyBitmap *bm = NULL;
1718 bm = bdrv_find_dirty_bitmap(bs, bitmap);
1723 bs = bdrv_filter_or_cow_bs(bs);
1728 error_setg(errp, "Bitmap '%s' is not found", bitmap);
1732 if (bdrv_dirty_bitmap_check(bm, BDRV_BITMAP_ALLOW_RO, errp)) {
1737 if (readonly && bdrv_is_writable(bs) &&
1738 bdrv_dirty_bitmap_enabled(bm)) {
1741 "Enabled bitmap '%s' incompatible with readonly export",
1746 exp->export_bitmaps[i] = bm;
1747 assert(strlen(bitmap) <= BDRV_BITMAP_MAX_NAME_SIZE);
1750 /* Mark bitmaps busy in a separate loop, to simplify roll-back concerns. */
1751 for (i = 0; i < exp->nr_export_bitmaps; i++) {
1752 bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], true);
1755 exp->allocation_depth = arg->allocation_depth;
1758 * We need to inhibit request queuing in the block layer to ensure we can
1759 * be properly quiesced when entering a drained section, as our coroutines
1760 * servicing pending requests might enter blk_pread().
1762 blk_set_disable_request_queuing(blk, true);
1764 blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp);
1766 blk_set_dev_ops(blk, &nbd_block_ops, exp);
1768 QTAILQ_INSERT_TAIL(&exports, exp, next);
1773 g_free(exp->export_bitmaps);
1775 g_free(exp->description);
1779 NBDExport *nbd_export_find(const char *name)
1782 QTAILQ_FOREACH(exp, &exports, next) {
1783 if (strcmp(name, exp->name) == 0) {
1792 nbd_export_aio_context(NBDExport *exp)
1794 return exp->common.ctx;
1797 static void nbd_export_request_shutdown(BlockExport *blk_exp)
1799 NBDExport *exp = container_of(blk_exp, NBDExport, common);
1800 NBDClient *client, *next;
1802 blk_exp_ref(&exp->common);
1804 * TODO: Should we expand QMP NbdServerRemoveNode enum to allow a
1805 * close mode that stops advertising the export to new clients but
1806 * still permits existing clients to run to completion? Because of
1807 * that possibility, nbd_export_close() can be called more than
1808 * once on an export.
1810 QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) {
1811 client_close(client, true);
1816 QTAILQ_REMOVE(&exports, exp, next);
1818 blk_exp_unref(&exp->common);
1821 static void nbd_export_delete(BlockExport *blk_exp)
1824 NBDExport *exp = container_of(blk_exp, NBDExport, common);
1826 assert(exp->name == NULL);
1827 assert(QTAILQ_EMPTY(&exp->clients));
1829 g_free(exp->description);
1830 exp->description = NULL;
1832 if (exp->common.blk) {
1833 if (exp->eject_notifier_blk) {
1834 notifier_remove(&exp->eject_notifier);
1835 blk_unref(exp->eject_notifier_blk);
1837 blk_remove_aio_context_notifier(exp->common.blk, blk_aio_attached,
1838 blk_aio_detach, exp);
1839 blk_set_disable_request_queuing(exp->common.blk, false);
1842 for (i = 0; i < exp->nr_export_bitmaps; i++) {
1843 bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], false);
1847 const BlockExportDriver blk_exp_nbd = {
1848 .type = BLOCK_EXPORT_TYPE_NBD,
1849 .instance_size = sizeof(NBDExport),
1850 .create = nbd_export_create,
1851 .delete = nbd_export_delete,
1852 .request_shutdown = nbd_export_request_shutdown,
1855 static int coroutine_fn nbd_co_send_iov(NBDClient *client, struct iovec *iov,
1856 unsigned niov, Error **errp)
1860 g_assert(qemu_in_coroutine());
1861 qemu_co_mutex_lock(&client->send_lock);
1862 client->send_coroutine = qemu_coroutine_self();
1864 ret = qio_channel_writev_all(client->ioc, iov, niov, errp) < 0 ? -EIO : 0;
1866 client->send_coroutine = NULL;
1867 qemu_co_mutex_unlock(&client->send_lock);
1872 static inline void set_be_simple_reply(NBDSimpleReply *reply, uint64_t error,
1875 stl_be_p(&reply->magic, NBD_SIMPLE_REPLY_MAGIC);
1876 stl_be_p(&reply->error, error);
1877 stq_be_p(&reply->handle, handle);
1880 static int nbd_co_send_simple_reply(NBDClient *client,
1887 NBDSimpleReply reply;
1888 int nbd_err = system_errno_to_nbd_errno(error);
1889 struct iovec iov[] = {
1890 {.iov_base = &reply, .iov_len = sizeof(reply)},
1891 {.iov_base = data, .iov_len = len}
1894 trace_nbd_co_send_simple_reply(handle, nbd_err, nbd_err_lookup(nbd_err),
1896 set_be_simple_reply(&reply, nbd_err, handle);
1898 return nbd_co_send_iov(client, iov, len ? 2 : 1, errp);
1901 static inline void set_be_chunk(NBDStructuredReplyChunk *chunk, uint16_t flags,
1902 uint16_t type, uint64_t handle, uint32_t length)
1904 stl_be_p(&chunk->magic, NBD_STRUCTURED_REPLY_MAGIC);
1905 stw_be_p(&chunk->flags, flags);
1906 stw_be_p(&chunk->type, type);
1907 stq_be_p(&chunk->handle, handle);
1908 stl_be_p(&chunk->length, length);
1911 static int coroutine_fn nbd_co_send_structured_done(NBDClient *client,
1915 NBDStructuredReplyChunk chunk;
1916 struct iovec iov[] = {
1917 {.iov_base = &chunk, .iov_len = sizeof(chunk)},
1920 trace_nbd_co_send_structured_done(handle);
1921 set_be_chunk(&chunk, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_NONE, handle, 0);
1923 return nbd_co_send_iov(client, iov, 1, errp);
1926 static int coroutine_fn nbd_co_send_structured_read(NBDClient *client,
1934 NBDStructuredReadData chunk;
1935 struct iovec iov[] = {
1936 {.iov_base = &chunk, .iov_len = sizeof(chunk)},
1937 {.iov_base = data, .iov_len = size}
1941 trace_nbd_co_send_structured_read(handle, offset, data, size);
1942 set_be_chunk(&chunk.h, final ? NBD_REPLY_FLAG_DONE : 0,
1943 NBD_REPLY_TYPE_OFFSET_DATA, handle,
1944 sizeof(chunk) - sizeof(chunk.h) + size);
1945 stq_be_p(&chunk.offset, offset);
1947 return nbd_co_send_iov(client, iov, 2, errp);
1950 static int coroutine_fn nbd_co_send_structured_error(NBDClient *client,
1956 NBDStructuredError chunk;
1957 int nbd_err = system_errno_to_nbd_errno(error);
1958 struct iovec iov[] = {
1959 {.iov_base = &chunk, .iov_len = sizeof(chunk)},
1960 {.iov_base = (char *)msg, .iov_len = msg ? strlen(msg) : 0},
1964 trace_nbd_co_send_structured_error(handle, nbd_err,
1965 nbd_err_lookup(nbd_err), msg ? msg : "");
1966 set_be_chunk(&chunk.h, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_ERROR, handle,
1967 sizeof(chunk) - sizeof(chunk.h) + iov[1].iov_len);
1968 stl_be_p(&chunk.error, nbd_err);
1969 stw_be_p(&chunk.message_length, iov[1].iov_len);
1971 return nbd_co_send_iov(client, iov, 1 + !!iov[1].iov_len, errp);
1974 /* Do a sparse read and send the structured reply to the client.
1975 * Returns -errno if sending fails. bdrv_block_status_above() failure is
1976 * reported to the client, at which point this function succeeds.
1978 static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client,
1986 NBDExport *exp = client->exp;
1987 size_t progress = 0;
1989 while (progress < size) {
1991 int status = bdrv_block_status_above(blk_bs(exp->common.blk), NULL,
1993 size - progress, &pnum, NULL,
1998 char *msg = g_strdup_printf("unable to check for holes: %s",
2001 ret = nbd_co_send_structured_error(client, handle, -status, msg,
2006 assert(pnum && pnum <= size - progress);
2007 final = progress + pnum == size;
2008 if (status & BDRV_BLOCK_ZERO) {
2009 NBDStructuredReadHole chunk;
2010 struct iovec iov[] = {
2011 {.iov_base = &chunk, .iov_len = sizeof(chunk)},
2014 trace_nbd_co_send_structured_read_hole(handle, offset + progress,
2016 set_be_chunk(&chunk.h, final ? NBD_REPLY_FLAG_DONE : 0,
2017 NBD_REPLY_TYPE_OFFSET_HOLE,
2018 handle, sizeof(chunk) - sizeof(chunk.h));
2019 stq_be_p(&chunk.offset, offset + progress);
2020 stl_be_p(&chunk.length, pnum);
2021 ret = nbd_co_send_iov(client, iov, 1, errp);
2023 ret = blk_pread(exp->common.blk, offset + progress,
2024 data + progress, pnum);
2026 error_setg_errno(errp, -ret, "reading from file failed");
2029 ret = nbd_co_send_structured_read(client, handle, offset + progress,
2030 data + progress, pnum, final,
2042 typedef struct NBDExtentArray {
2044 unsigned int nb_alloc;
2046 uint64_t total_length;
2048 bool converted_to_be;
2051 static NBDExtentArray *nbd_extent_array_new(unsigned int nb_alloc)
2053 NBDExtentArray *ea = g_new0(NBDExtentArray, 1);
2055 ea->nb_alloc = nb_alloc;
2056 ea->extents = g_new(NBDExtent, nb_alloc);
2062 static void nbd_extent_array_free(NBDExtentArray *ea)
2064 g_free(ea->extents);
2067 G_DEFINE_AUTOPTR_CLEANUP_FUNC(NBDExtentArray, nbd_extent_array_free);
2069 /* Further modifications of the array after conversion are abandoned */
2070 static void nbd_extent_array_convert_to_be(NBDExtentArray *ea)
2074 assert(!ea->converted_to_be);
2075 ea->can_add = false;
2076 ea->converted_to_be = true;
2078 for (i = 0; i < ea->count; i++) {
2079 ea->extents[i].flags = cpu_to_be32(ea->extents[i].flags);
2080 ea->extents[i].length = cpu_to_be32(ea->extents[i].length);
2085 * Add extent to NBDExtentArray. If extent can't be added (no available space),
2087 * For safety, when returning -1 for the first time, .can_add is set to false,
2088 * and further calls to nbd_extent_array_add() will crash.
2089 * (this avoids the situation where a caller ignores failure to add one extent,
2090 * where adding another extent that would squash into the last array entry
2091 * would result in an incorrect range reported to the client)
2093 static int nbd_extent_array_add(NBDExtentArray *ea,
2094 uint32_t length, uint32_t flags)
2096 assert(ea->can_add);
2102 /* Extend previous extent if flags are the same */
2103 if (ea->count > 0 && flags == ea->extents[ea->count - 1].flags) {
2104 uint64_t sum = (uint64_t)length + ea->extents[ea->count - 1].length;
2106 if (sum <= UINT32_MAX) {
2107 ea->extents[ea->count - 1].length = sum;
2108 ea->total_length += length;
2113 if (ea->count >= ea->nb_alloc) {
2114 ea->can_add = false;
2118 ea->total_length += length;
2119 ea->extents[ea->count] = (NBDExtent) {.length = length, .flags = flags};
2125 static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
2126 uint64_t bytes, NBDExtentArray *ea)
2131 int ret = bdrv_block_status_above(bs, NULL, offset, bytes, &num,
2138 flags = (ret & BDRV_BLOCK_DATA ? 0 : NBD_STATE_HOLE) |
2139 (ret & BDRV_BLOCK_ZERO ? NBD_STATE_ZERO : 0);
2141 if (nbd_extent_array_add(ea, num, flags) < 0) {
2152 static int blockalloc_to_extents(BlockDriverState *bs, uint64_t offset,
2153 uint64_t bytes, NBDExtentArray *ea)
2157 int ret = bdrv_is_allocated_above(bs, NULL, false, offset, bytes,
2164 if (nbd_extent_array_add(ea, num, ret) < 0) {
2176 * nbd_co_send_extents
2178 * @ea is converted to BE by the function
2179 * @last controls whether NBD_REPLY_FLAG_DONE is sent.
2181 static int nbd_co_send_extents(NBDClient *client, uint64_t handle,
2183 bool last, uint32_t context_id, Error **errp)
2185 NBDStructuredMeta chunk;
2186 struct iovec iov[] = {
2187 {.iov_base = &chunk, .iov_len = sizeof(chunk)},
2188 {.iov_base = ea->extents, .iov_len = ea->count * sizeof(ea->extents[0])}
2191 nbd_extent_array_convert_to_be(ea);
2193 trace_nbd_co_send_extents(handle, ea->count, context_id, ea->total_length,
2195 set_be_chunk(&chunk.h, last ? NBD_REPLY_FLAG_DONE : 0,
2196 NBD_REPLY_TYPE_BLOCK_STATUS,
2197 handle, sizeof(chunk) - sizeof(chunk.h) + iov[1].iov_len);
2198 stl_be_p(&chunk.context_id, context_id);
2200 return nbd_co_send_iov(client, iov, 2, errp);
2203 /* Get block status from the exported device and send it to the client */
2204 static int nbd_co_send_block_status(NBDClient *client, uint64_t handle,
2205 BlockDriverState *bs, uint64_t offset,
2206 uint32_t length, bool dont_fragment,
2207 bool last, uint32_t context_id,
2211 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
2212 g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
2214 if (context_id == NBD_META_ID_BASE_ALLOCATION) {
2215 ret = blockstatus_to_extents(bs, offset, length, ea);
2217 ret = blockalloc_to_extents(bs, offset, length, ea);
2220 return nbd_co_send_structured_error(
2221 client, handle, -ret, "can't get block status", errp);
2224 return nbd_co_send_extents(client, handle, ea, last, context_id, errp);
2227 /* Populate @ea from a dirty bitmap. */
2228 static void bitmap_to_extents(BdrvDirtyBitmap *bitmap,
2229 uint64_t offset, uint64_t length,
2232 int64_t start, dirty_start, dirty_count;
2233 int64_t end = offset + length;
2236 bdrv_dirty_bitmap_lock(bitmap);
2238 for (start = offset;
2239 bdrv_dirty_bitmap_next_dirty_area(bitmap, start, end, INT32_MAX,
2240 &dirty_start, &dirty_count);
2241 start = dirty_start + dirty_count)
2243 if ((nbd_extent_array_add(es, dirty_start - start, 0) < 0) ||
2244 (nbd_extent_array_add(es, dirty_count, NBD_STATE_DIRTY) < 0))
2252 /* last non dirty extent, nothing to do if array is now full */
2253 (void) nbd_extent_array_add(es, end - start, 0);
2256 bdrv_dirty_bitmap_unlock(bitmap);
2259 static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
2260 BdrvDirtyBitmap *bitmap, uint64_t offset,
2261 uint32_t length, bool dont_fragment, bool last,
2262 uint32_t context_id, Error **errp)
2264 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
2265 g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
2267 bitmap_to_extents(bitmap, offset, length, ea);
2269 return nbd_co_send_extents(client, handle, ea, last, context_id, errp);
2272 /* nbd_co_receive_request
2273 * Collect a client request. Return 0 if request looks valid, -EIO to drop
2274 * connection right away, -EAGAIN to indicate we were interrupted and the
2275 * channel should be quiesced, and any other negative value to report an error
2276 * to the client (although the caller may still need to disconnect after
2277 * reporting the error).
2279 static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request,
2282 NBDClient *client = req->client;
2286 g_assert(qemu_in_coroutine());
2287 assert(client->recv_coroutine == qemu_coroutine_self());
2288 ret = nbd_receive_request(client, request, errp);
2293 trace_nbd_co_receive_request_decode_type(request->handle, request->type,
2294 nbd_cmd_lookup(request->type));
2296 if (request->type != NBD_CMD_WRITE) {
2297 /* No payload, we are ready to read the next request. */
2298 req->complete = true;
2301 if (request->type == NBD_CMD_DISC) {
2302 /* Special case: we're going to disconnect without a reply,
2303 * whether or not flags, from, or len are bogus */
2307 if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE ||
2308 request->type == NBD_CMD_CACHE)
2310 if (request->len > NBD_MAX_BUFFER_SIZE) {
2311 error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)",
2312 request->len, NBD_MAX_BUFFER_SIZE);
2316 if (request->type != NBD_CMD_CACHE) {
2317 req->data = blk_try_blockalign(client->exp->common.blk,
2319 if (req->data == NULL) {
2320 error_setg(errp, "No memory");
2326 if (request->type == NBD_CMD_WRITE) {
2327 if (nbd_read(client->ioc, req->data, request->len, "CMD_WRITE data",
2332 req->complete = true;
2334 trace_nbd_co_receive_request_payload_received(request->handle,
2338 /* Sanity checks. */
2339 if (client->exp->nbdflags & NBD_FLAG_READ_ONLY &&
2340 (request->type == NBD_CMD_WRITE ||
2341 request->type == NBD_CMD_WRITE_ZEROES ||
2342 request->type == NBD_CMD_TRIM)) {
2343 error_setg(errp, "Export is read-only");
2346 if (request->from > client->exp->size ||
2347 request->len > client->exp->size - request->from) {
2348 error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32
2349 ", Size: %" PRIu64, request->from, request->len,
2351 return (request->type == NBD_CMD_WRITE ||
2352 request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL;
2354 if (client->check_align && !QEMU_IS_ALIGNED(request->from | request->len,
2355 client->check_align)) {
2357 * The block layer gracefully handles unaligned requests, but
2358 * it's still worth tracing client non-compliance
2360 trace_nbd_co_receive_align_compliance(nbd_cmd_lookup(request->type),
2363 client->check_align);
2365 valid_flags = NBD_CMD_FLAG_FUA;
2366 if (request->type == NBD_CMD_READ && client->structured_reply) {
2367 valid_flags |= NBD_CMD_FLAG_DF;
2368 } else if (request->type == NBD_CMD_WRITE_ZEROES) {
2369 valid_flags |= NBD_CMD_FLAG_NO_HOLE | NBD_CMD_FLAG_FAST_ZERO;
2370 } else if (request->type == NBD_CMD_BLOCK_STATUS) {
2371 valid_flags |= NBD_CMD_FLAG_REQ_ONE;
2373 if (request->flags & ~valid_flags) {
2374 error_setg(errp, "unsupported flags for command %s (got 0x%x)",
2375 nbd_cmd_lookup(request->type), request->flags);
2382 /* Send simple reply without a payload, or a structured error
2383 * @error_msg is ignored if @ret >= 0
2384 * Returns 0 if connection is still live, -errno on failure to talk to client
2386 static coroutine_fn int nbd_send_generic_reply(NBDClient *client,
2389 const char *error_msg,
2392 if (client->structured_reply && ret < 0) {
2393 return nbd_co_send_structured_error(client, handle, -ret, error_msg,
2396 return nbd_co_send_simple_reply(client, handle, ret < 0 ? -ret : 0,
2401 /* Handle NBD_CMD_READ request.
2402 * Return -errno if sending fails. Other errors are reported directly to the
2403 * client as an error reply. */
2404 static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request,
2405 uint8_t *data, Error **errp)
2408 NBDExport *exp = client->exp;
2410 assert(request->type == NBD_CMD_READ);
2412 /* XXX: NBD Protocol only documents use of FUA with WRITE */
2413 if (request->flags & NBD_CMD_FLAG_FUA) {
2414 ret = blk_co_flush(exp->common.blk);
2416 return nbd_send_generic_reply(client, request->handle, ret,
2417 "flush failed", errp);
2421 if (client->structured_reply && !(request->flags & NBD_CMD_FLAG_DF) &&
2424 return nbd_co_send_sparse_read(client, request->handle, request->from,
2425 data, request->len, errp);
2428 ret = blk_pread(exp->common.blk, request->from, data, request->len);
2430 return nbd_send_generic_reply(client, request->handle, ret,
2431 "reading from file failed", errp);
2434 if (client->structured_reply) {
2436 return nbd_co_send_structured_read(client, request->handle,
2437 request->from, data,
2438 request->len, true, errp);
2440 return nbd_co_send_structured_done(client, request->handle, errp);
2443 return nbd_co_send_simple_reply(client, request->handle, 0,
2444 data, request->len, errp);
2451 * Handle NBD_CMD_CACHE request.
2452 * Return -errno if sending fails. Other errors are reported directly to the
2453 * client as an error reply.
2455 static coroutine_fn int nbd_do_cmd_cache(NBDClient *client, NBDRequest *request,
2459 NBDExport *exp = client->exp;
2461 assert(request->type == NBD_CMD_CACHE);
2463 ret = blk_co_preadv(exp->common.blk, request->from, request->len,
2464 NULL, BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH);
2466 return nbd_send_generic_reply(client, request->handle, ret,
2467 "caching data failed", errp);
2470 /* Handle NBD request.
2471 * Return -errno if sending fails. Other errors are reported directly to the
2472 * client as an error reply. */
2473 static coroutine_fn int nbd_handle_request(NBDClient *client,
2474 NBDRequest *request,
2475 uint8_t *data, Error **errp)
2479 NBDExport *exp = client->exp;
2483 switch (request->type) {
2485 return nbd_do_cmd_cache(client, request, errp);
2488 return nbd_do_cmd_read(client, request, data, errp);
2492 if (request->flags & NBD_CMD_FLAG_FUA) {
2493 flags |= BDRV_REQ_FUA;
2495 ret = blk_pwrite(exp->common.blk, request->from, data, request->len,
2497 return nbd_send_generic_reply(client, request->handle, ret,
2498 "writing to file failed", errp);
2500 case NBD_CMD_WRITE_ZEROES:
2502 if (request->flags & NBD_CMD_FLAG_FUA) {
2503 flags |= BDRV_REQ_FUA;
2505 if (!(request->flags & NBD_CMD_FLAG_NO_HOLE)) {
2506 flags |= BDRV_REQ_MAY_UNMAP;
2508 if (request->flags & NBD_CMD_FLAG_FAST_ZERO) {
2509 flags |= BDRV_REQ_NO_FALLBACK;
2511 ret = blk_pwrite_zeroes(exp->common.blk, request->from, request->len,
2513 return nbd_send_generic_reply(client, request->handle, ret,
2514 "writing to file failed", errp);
2517 /* unreachable, thanks to special case in nbd_co_receive_request() */
2521 ret = blk_co_flush(exp->common.blk);
2522 return nbd_send_generic_reply(client, request->handle, ret,
2523 "flush failed", errp);
2526 ret = blk_co_pdiscard(exp->common.blk, request->from, request->len);
2527 if (ret >= 0 && request->flags & NBD_CMD_FLAG_FUA) {
2528 ret = blk_co_flush(exp->common.blk);
2530 return nbd_send_generic_reply(client, request->handle, ret,
2531 "discard failed", errp);
2533 case NBD_CMD_BLOCK_STATUS:
2534 if (!request->len) {
2535 return nbd_send_generic_reply(client, request->handle, -EINVAL,
2536 "need non-zero length", errp);
2538 if (client->export_meta.count) {
2539 bool dont_fragment = request->flags & NBD_CMD_FLAG_REQ_ONE;
2540 int contexts_remaining = client->export_meta.count;
2542 if (client->export_meta.base_allocation) {
2543 ret = nbd_co_send_block_status(client, request->handle,
2544 blk_bs(exp->common.blk),
2546 request->len, dont_fragment,
2547 !--contexts_remaining,
2548 NBD_META_ID_BASE_ALLOCATION,
2555 if (client->export_meta.allocation_depth) {
2556 ret = nbd_co_send_block_status(client, request->handle,
2557 blk_bs(exp->common.blk),
2558 request->from, request->len,
2560 !--contexts_remaining,
2561 NBD_META_ID_ALLOCATION_DEPTH,
2568 for (i = 0; i < client->exp->nr_export_bitmaps; i++) {
2569 if (!client->export_meta.bitmaps[i]) {
2572 ret = nbd_co_send_bitmap(client, request->handle,
2573 client->exp->export_bitmaps[i],
2574 request->from, request->len,
2575 dont_fragment, !--contexts_remaining,
2576 NBD_META_ID_DIRTY_BITMAP + i, errp);
2582 assert(!contexts_remaining);
2586 return nbd_send_generic_reply(client, request->handle, -EINVAL,
2587 "CMD_BLOCK_STATUS not negotiated",
2592 msg = g_strdup_printf("invalid request type (%" PRIu32 ") received",
2594 ret = nbd_send_generic_reply(client, request->handle, -EINVAL, msg,
2601 /* Owns a reference to the NBDClient passed as opaque. */
2602 static coroutine_fn void nbd_trip(void *opaque)
2604 NBDClient *client = opaque;
2605 NBDRequestData *req;
2606 NBDRequest request = { 0 }; /* GCC thinks it can be used uninitialized */
2608 Error *local_err = NULL;
2611 if (client->closing) {
2612 nbd_client_put(client);
2616 if (client->quiescing) {
2618 * We're switching between AIO contexts. Don't attempt to receive a new
2619 * request and kick the main context which may be waiting for us.
2621 nbd_client_put(client);
2622 client->recv_coroutine = NULL;
2627 req = nbd_request_get(client);
2628 ret = nbd_co_receive_request(req, &request, &local_err);
2629 client->recv_coroutine = NULL;
2631 if (client->closing) {
2633 * The client may be closed when we are blocked in
2634 * nbd_co_receive_request()
2639 if (ret == -EAGAIN) {
2640 assert(client->quiescing);
2644 nbd_client_receive_next_request(client);
2650 /* It wasn't -EIO, so, according to nbd_co_receive_request()
2651 * semantics, we should return the error to the client. */
2652 Error *export_err = local_err;
2655 ret = nbd_send_generic_reply(client, request.handle, -EINVAL,
2656 error_get_pretty(export_err), &local_err);
2657 error_free(export_err);
2659 ret = nbd_handle_request(client, &request, req->data, &local_err);
2662 error_prepend(&local_err, "Failed to send reply: ");
2666 /* We must disconnect after NBD_CMD_WRITE if we did not
2669 if (!req->complete) {
2670 error_setg(&local_err, "Request handling failed in intermediate state");
2675 nbd_request_put(req);
2676 nbd_client_put(client);
2681 error_reportf_err(local_err, "Disconnect client, due to: ");
2683 nbd_request_put(req);
2684 client_close(client, true);
2685 nbd_client_put(client);
2688 static void nbd_client_receive_next_request(NBDClient *client)
2690 if (!client->recv_coroutine && client->nb_requests < MAX_NBD_REQUESTS &&
2691 !client->quiescing) {
2692 nbd_client_get(client);
2693 client->recv_coroutine = qemu_coroutine_create(nbd_trip, client);
2694 aio_co_schedule(client->exp->common.ctx, client->recv_coroutine);
2698 static coroutine_fn void nbd_co_client_start(void *opaque)
2700 NBDClient *client = opaque;
2701 Error *local_err = NULL;
2703 qemu_co_mutex_init(&client->send_lock);
2705 if (nbd_negotiate(client, &local_err)) {
2707 error_report_err(local_err);
2709 client_close(client, false);
2713 nbd_client_receive_next_request(client);
2717 * Create a new client listener using the given channel @sioc.
2718 * Begin servicing it in a coroutine. When the connection closes, call
2719 * @close_fn with an indication of whether the client completed negotiation.
2721 void nbd_client_new(QIOChannelSocket *sioc,
2722 QCryptoTLSCreds *tlscreds,
2723 const char *tlsauthz,
2724 void (*close_fn)(NBDClient *, bool))
2729 client = g_new0(NBDClient, 1);
2730 client->refcount = 1;
2731 client->tlscreds = tlscreds;
2733 object_ref(OBJECT(client->tlscreds));
2735 client->tlsauthz = g_strdup(tlsauthz);
2736 client->sioc = sioc;
2737 object_ref(OBJECT(client->sioc));
2738 client->ioc = QIO_CHANNEL(sioc);
2739 object_ref(OBJECT(client->ioc));
2740 client->close_fn = close_fn;
2742 co = qemu_coroutine_create(nbd_co_client_start, client);
2743 qemu_coroutine_enter(co);