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