1 /* 2 * Copyright (C) 2016-2021 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 if (meta->exp->nr_export_bitmaps) { 883 memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps); 884 } 885 } 886 trace_nbd_negotiate_meta_query_parse("empty"); 887 return true; 888 } 889 890 if (strcmp(query, "allocation-depth") == 0) { 891 trace_nbd_negotiate_meta_query_parse("allocation-depth"); 892 meta->allocation_depth = meta->exp->allocation_depth; 893 return true; 894 } 895 896 if (nbd_strshift(&query, "dirty-bitmap:")) { 897 trace_nbd_negotiate_meta_query_parse("dirty-bitmap:"); 898 if (!*query) { 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); 902 } 903 trace_nbd_negotiate_meta_query_parse("empty"); 904 return true; 905 } 906 907 for (i = 0; i < meta->exp->nr_export_bitmaps; i++) { 908 const char *bm_name; 909 910 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); 914 return true; 915 } 916 } 917 trace_nbd_negotiate_meta_query_skip("no dirty-bitmap match"); 918 return true; 919 } 920 921 trace_nbd_negotiate_meta_query_skip("unknown qemu context"); 922 return true; 923 } 924 925 /* nbd_negotiate_meta_query 926 * 927 * Parse namespace name and call corresponding function to parse body of the 928 * query. 929 * 930 * The only supported namespaces are 'base' and 'qemu'. 931 * 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) 936 { 937 int ret; 938 g_autofree char *query = NULL; 939 uint32_t len; 940 941 ret = nbd_opt_read(client, &len, sizeof(len), false, errp); 942 if (ret <= 0) { 943 return ret; 944 } 945 len = cpu_to_be32(len); 946 947 if (len > NBD_MAX_STRING_SIZE) { 948 trace_nbd_negotiate_meta_query_skip("length too long"); 949 return nbd_opt_skip(client, len, errp); 950 } 951 952 query = g_malloc(len + 1); 953 ret = nbd_opt_read(client, query, len, true, errp); 954 if (ret <= 0) { 955 return ret; 956 } 957 query[len] = '\0'; 958 959 if (nbd_meta_base_query(client, meta, query)) { 960 return 1; 961 } 962 if (nbd_meta_qemu_query(client, meta, query)) { 963 return 1; 964 } 965 966 trace_nbd_negotiate_meta_query_skip("unknown namespace"); 967 return 1; 968 } 969 970 /* nbd_negotiate_meta_queries 971 * Handle NBD_OPT_LIST_META_CONTEXT and NBD_OPT_SET_META_CONTEXT 972 * 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) 976 { 977 int ret; 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}; 982 uint32_t nb_queries; 983 size_t i; 984 size_t count = 0; 985 986 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 " 989 "is not negotiated", 990 nbd_opt_lookup(client->opt)); 991 } 992 993 if (client->opt == NBD_OPT_LIST_META_CONTEXT) { 994 /* Only change the caller's meta on SET. */ 995 meta = &local_meta; 996 } 997 998 g_free(meta->bitmaps); 999 memset(meta, 0, sizeof(*meta)); 1000 1001 ret = nbd_opt_read_name(client, &export_name, NULL, errp); 1002 if (ret <= 0) { 1003 return ret; 1004 } 1005 1006 meta->exp = nbd_export_find(export_name); 1007 if (meta->exp == NULL) { 1008 g_autofree char *sane_name = nbd_sanitize_name(export_name); 1009 1010 return nbd_opt_drop(client, NBD_REP_ERR_UNKNOWN, errp, 1011 "export '%s' not present", sane_name); 1012 } 1013 meta->bitmaps = g_new0(bool, meta->exp->nr_export_bitmaps); 1014 if (client->opt == NBD_OPT_LIST_META_CONTEXT) { 1015 bitmaps = meta->bitmaps; 1016 } 1017 1018 ret = nbd_opt_read(client, &nb_queries, sizeof(nb_queries), false, errp); 1019 if (ret <= 0) { 1020 return ret; 1021 } 1022 nb_queries = cpu_to_be32(nb_queries); 1023 trace_nbd_negotiate_meta_context(nbd_opt_lookup(client->opt), 1024 export_name, nb_queries); 1025 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); 1032 } 1033 } else { 1034 for (i = 0; i < nb_queries; ++i) { 1035 ret = nbd_negotiate_meta_query(client, meta, errp); 1036 if (ret <= 0) { 1037 return ret; 1038 } 1039 } 1040 } 1041 1042 if (meta->base_allocation) { 1043 ret = nbd_negotiate_send_meta_context(client, "base:allocation", 1044 NBD_META_ID_BASE_ALLOCATION, 1045 errp); 1046 if (ret < 0) { 1047 return ret; 1048 } 1049 count++; 1050 } 1051 1052 if (meta->allocation_depth) { 1053 ret = nbd_negotiate_send_meta_context(client, "qemu:allocation-depth", 1054 NBD_META_ID_ALLOCATION_DEPTH, 1055 errp); 1056 if (ret < 0) { 1057 return ret; 1058 } 1059 count++; 1060 } 1061 1062 for (i = 0; i < meta->exp->nr_export_bitmaps; i++) { 1063 const char *bm_name; 1064 g_autofree char *context = NULL; 1065 1066 if (!meta->bitmaps[i]) { 1067 continue; 1068 } 1069 1070 bm_name = bdrv_dirty_bitmap_name(meta->exp->export_bitmaps[i]); 1071 context = g_strdup_printf("qemu:dirty-bitmap:%s", bm_name); 1072 1073 ret = nbd_negotiate_send_meta_context(client, context, 1074 NBD_META_ID_DIRTY_BITMAP + i, 1075 errp); 1076 if (ret < 0) { 1077 return ret; 1078 } 1079 count++; 1080 } 1081 1082 ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); 1083 if (ret == 0) { 1084 meta->count = count; 1085 } 1086 1087 return ret; 1088 } 1089 1090 /* nbd_negotiate_options 1091 * Process all NBD_OPT_* client option commands, during fixed newstyle 1092 * negotiation. 1093 * Return: 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, 1097 * errp is not set 1098 */ 1099 static int nbd_negotiate_options(NBDClient *client, Error **errp) 1100 { 1101 uint32_t flags; 1102 bool fixedNewstyle = false; 1103 bool no_zeroes = false; 1104 1105 /* Client sends: 1106 [ 0 .. 3] client flags 1107 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 1112 ... Rest of request 1113 1114 [ 0 .. 7] NBD_OPTS_MAGIC 1115 [ 8 .. 11] Second NBD option 1116 [12 .. 15] Data length 1117 ... Rest of request 1118 */ 1119 1120 if (nbd_read32(client->ioc, &flags, "flags", errp) < 0) { 1121 return -EIO; 1122 } 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; 1127 } 1128 if (flags & NBD_FLAG_C_NO_ZEROES) { 1129 no_zeroes = true; 1130 flags &= ~NBD_FLAG_C_NO_ZEROES; 1131 } 1132 if (flags != 0) { 1133 error_setg(errp, "Unknown client flags 0x%" PRIx32 " received", flags); 1134 return -EINVAL; 1135 } 1136 1137 while (1) { 1138 int ret; 1139 uint32_t option, length; 1140 uint64_t magic; 1141 1142 if (nbd_read64(client->ioc, &magic, "opts magic", errp) < 0) { 1143 return -EINVAL; 1144 } 1145 trace_nbd_negotiate_options_check_magic(magic); 1146 if (magic != NBD_OPTS_MAGIC) { 1147 error_setg(errp, "Bad magic received"); 1148 return -EINVAL; 1149 } 1150 1151 if (nbd_read32(client->ioc, &option, "option", errp) < 0) { 1152 return -EINVAL; 1153 } 1154 client->opt = option; 1155 1156 if (nbd_read32(client->ioc, &length, "option length", errp) < 0) { 1157 return -EINVAL; 1158 } 1159 assert(!client->optlen); 1160 client->optlen = length; 1161 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); 1165 return -EINVAL; 1166 } 1167 1168 trace_nbd_negotiate_options_check_option(option, 1169 nbd_opt_lookup(option)); 1170 if (client->tlscreds && 1171 client->ioc == (QIOChannel *)client->sioc) { 1172 QIOChannel *tioc; 1173 if (!fixedNewstyle) { 1174 error_setg(errp, "Unsupported option 0x%" PRIx32, option); 1175 return -EINVAL; 1176 } 1177 switch (option) { 1178 case NBD_OPT_STARTTLS: 1179 if (length) { 1180 /* Unconditionally drop the connection if the client 1181 * can't start a TLS negotiation correctly */ 1182 return nbd_reject_length(client, true, errp); 1183 } 1184 tioc = nbd_negotiate_handle_starttls(client, errp); 1185 if (!tioc) { 1186 return -EIO; 1187 } 1188 ret = 0; 1189 object_unref(OBJECT(client->ioc)); 1190 client->ioc = QIO_CHANNEL(tioc); 1191 break; 1192 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", 1196 option); 1197 return -EINVAL; 1198 1199 default: 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, 1208 "Option 0x%" PRIx32 1209 " not permitted before TLS", option); 1210 if (option == NBD_OPT_ABORT) { 1211 return 1; 1212 } 1213 break; 1214 } 1215 } else if (fixedNewstyle) { 1216 switch (option) { 1217 case NBD_OPT_LIST: 1218 if (length) { 1219 ret = nbd_reject_length(client, false, errp); 1220 } else { 1221 ret = nbd_negotiate_handle_list(client, errp); 1222 } 1223 break; 1224 1225 case NBD_OPT_ABORT: 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); 1230 return 1; 1231 1232 case NBD_OPT_EXPORT_NAME: 1233 return nbd_negotiate_handle_export_name(client, no_zeroes, 1234 errp); 1235 1236 case NBD_OPT_INFO: 1237 case NBD_OPT_GO: 1238 ret = nbd_negotiate_handle_info(client, errp); 1239 if (ret == 1) { 1240 assert(option == NBD_OPT_GO); 1241 return 0; 1242 } 1243 break; 1244 1245 case NBD_OPT_STARTTLS: 1246 if (length) { 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"); 1252 } else { 1253 ret = nbd_negotiate_send_rep_err(client, 1254 NBD_REP_ERR_POLICY, errp, 1255 "TLS not configured"); 1256 } 1257 break; 1258 1259 case NBD_OPT_STRUCTURED_REPLY: 1260 if (length) { 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"); 1266 } else { 1267 ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); 1268 client->structured_reply = true; 1269 } 1270 break; 1271 1272 case NBD_OPT_LIST_META_CONTEXT: 1273 case NBD_OPT_SET_META_CONTEXT: 1274 ret = nbd_negotiate_meta_queries(client, &client->export_meta, 1275 errp); 1276 break; 1277 1278 default: 1279 ret = nbd_opt_drop(client, NBD_REP_ERR_UNSUP, errp, 1280 "Unsupported option %" PRIu32 " (%s)", 1281 option, nbd_opt_lookup(option)); 1282 break; 1283 } 1284 } else { 1285 /* 1286 * If broken new-style we should drop the connection 1287 * for anything except NBD_OPT_EXPORT_NAME 1288 */ 1289 switch (option) { 1290 case NBD_OPT_EXPORT_NAME: 1291 return nbd_negotiate_handle_export_name(client, no_zeroes, 1292 errp); 1293 1294 default: 1295 error_setg(errp, "Unsupported option %" PRIu32 " (%s)", 1296 option, nbd_opt_lookup(option)); 1297 return -EINVAL; 1298 } 1299 } 1300 if (ret < 0) { 1301 return ret; 1302 } 1303 } 1304 } 1305 1306 /* nbd_negotiate 1307 * Return: 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, 1311 * errp is not set 1312 */ 1313 static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp) 1314 { 1315 ERRP_GUARD(); 1316 char buf[NBD_OLDSTYLE_NEGOTIATE_SIZE] = ""; 1317 int ret; 1318 1319 /* Old style negotiation header, no room for options 1320 [ 0 .. 7] passwd ("NBDMAGIC") 1321 [ 8 .. 15] magic (NBD_CLIENT_MAGIC) 1322 [16 .. 23] size 1323 [24 .. 27] export flags (zero-extended) 1324 [28 .. 151] reserved (0) 1325 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.... 1331 */ 1332 1333 qio_channel_set_blocking(client->ioc, false, NULL); 1334 1335 trace_nbd_negotiate_begin(); 1336 memcpy(buf, "NBDMAGIC", 8); 1337 1338 stq_be_p(buf + 8, NBD_OPTS_MAGIC); 1339 stw_be_p(buf + 16, NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES); 1340 1341 if (nbd_write(client->ioc, buf, 18, errp) < 0) { 1342 error_prepend(errp, "write failed: "); 1343 return -EINVAL; 1344 } 1345 ret = nbd_negotiate_options(client, errp); 1346 if (ret != 0) { 1347 if (ret < 0) { 1348 error_prepend(errp, "option negotiation failed: "); 1349 } 1350 return ret; 1351 } 1352 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); 1356 } 1357 1358 assert(!client->optlen); 1359 trace_nbd_negotiate_success(); 1360 1361 return 0; 1362 } 1363 1364 /* nbd_read_eof 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) 1371 */ 1372 static inline int coroutine_fn 1373 nbd_read_eof(NBDClient *client, void *buffer, size_t size, Error **errp) 1374 { 1375 bool partial = false; 1376 1377 assert(size); 1378 while (size > 0) { 1379 struct iovec iov = { .iov_base = buffer, .iov_len = size }; 1380 ssize_t len; 1381 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) { 1388 return -EAGAIN; 1389 } 1390 continue; 1391 } else if (len < 0) { 1392 return -EIO; 1393 } else if (len == 0) { 1394 if (partial) { 1395 error_setg(errp, 1396 "Unexpected end-of-file before all bytes were read"); 1397 return -EIO; 1398 } else { 1399 return 0; 1400 } 1401 } 1402 1403 partial = true; 1404 size -= len; 1405 buffer = (uint8_t *) buffer + len; 1406 } 1407 return 1; 1408 } 1409 1410 static int nbd_receive_request(NBDClient *client, NBDRequest *request, 1411 Error **errp) 1412 { 1413 uint8_t buf[NBD_REQUEST_SIZE]; 1414 uint32_t magic; 1415 int ret; 1416 1417 ret = nbd_read_eof(client, buf, sizeof(buf), errp); 1418 if (ret < 0) { 1419 return ret; 1420 } 1421 1422 /* Request 1423 [ 0 .. 3] magic (NBD_REQUEST_MAGIC) 1424 [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...) 1425 [ 6 .. 7] type (NBD_CMD_READ, ...) 1426 [ 8 .. 15] handle 1427 [16 .. 23] from 1428 [24 .. 27] len 1429 */ 1430 1431 magic = ldl_be_p(buf); 1432 request->flags = lduw_be_p(buf + 4); 1433 request->type = lduw_be_p(buf + 6); 1434 request->handle = ldq_be_p(buf + 8); 1435 request->from = ldq_be_p(buf + 16); 1436 request->len = ldl_be_p(buf + 24); 1437 1438 trace_nbd_receive_request(magic, request->flags, request->type, 1439 request->from, request->len); 1440 1441 if (magic != NBD_REQUEST_MAGIC) { 1442 error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", magic); 1443 return -EINVAL; 1444 } 1445 return 0; 1446 } 1447 1448 #define MAX_NBD_REQUESTS 16 1449 1450 void nbd_client_get(NBDClient *client) 1451 { 1452 client->refcount++; 1453 } 1454 1455 void nbd_client_put(NBDClient *client) 1456 { 1457 if (--client->refcount == 0) { 1458 /* The last reference should be dropped by client->close, 1459 * which is called by client_close. 1460 */ 1461 assert(client->closing); 1462 1463 qio_channel_detach_aio_context(client->ioc); 1464 object_unref(OBJECT(client->sioc)); 1465 object_unref(OBJECT(client->ioc)); 1466 if (client->tlscreds) { 1467 object_unref(OBJECT(client->tlscreds)); 1468 } 1469 g_free(client->tlsauthz); 1470 if (client->exp) { 1471 QTAILQ_REMOVE(&client->exp->clients, client, next); 1472 blk_exp_unref(&client->exp->common); 1473 } 1474 g_free(client->export_meta.bitmaps); 1475 g_free(client); 1476 } 1477 } 1478 1479 static void client_close(NBDClient *client, bool negotiated) 1480 { 1481 if (client->closing) { 1482 return; 1483 } 1484 1485 client->closing = true; 1486 1487 /* Force requests to finish. They will drop their own references, 1488 * then we'll close the socket and free the NBDClient. 1489 */ 1490 qio_channel_shutdown(client->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, 1491 NULL); 1492 1493 /* Also tell the client, so that they release their reference. */ 1494 if (client->close_fn) { 1495 client->close_fn(client, negotiated); 1496 } 1497 } 1498 1499 static NBDRequestData *nbd_request_get(NBDClient *client) 1500 { 1501 NBDRequestData *req; 1502 1503 assert(client->nb_requests <= MAX_NBD_REQUESTS - 1); 1504 client->nb_requests++; 1505 1506 req = g_new0(NBDRequestData, 1); 1507 nbd_client_get(client); 1508 req->client = client; 1509 return req; 1510 } 1511 1512 static void nbd_request_put(NBDRequestData *req) 1513 { 1514 NBDClient *client = req->client; 1515 1516 if (req->data) { 1517 qemu_vfree(req->data); 1518 } 1519 g_free(req); 1520 1521 client->nb_requests--; 1522 1523 if (client->quiescing && client->nb_requests == 0) { 1524 aio_wait_kick(); 1525 } 1526 1527 nbd_client_receive_next_request(client); 1528 1529 nbd_client_put(client); 1530 } 1531 1532 static void blk_aio_attached(AioContext *ctx, void *opaque) 1533 { 1534 NBDExport *exp = opaque; 1535 NBDClient *client; 1536 1537 trace_nbd_blk_aio_attached(exp->name, ctx); 1538 1539 exp->common.ctx = ctx; 1540 1541 QTAILQ_FOREACH(client, &exp->clients, next) { 1542 qio_channel_attach_aio_context(client->ioc, ctx); 1543 1544 assert(client->nb_requests == 0); 1545 assert(client->recv_coroutine == NULL); 1546 assert(client->send_coroutine == NULL); 1547 } 1548 } 1549 1550 static void blk_aio_detach(void *opaque) 1551 { 1552 NBDExport *exp = opaque; 1553 NBDClient *client; 1554 1555 trace_nbd_blk_aio_detach(exp->name, exp->common.ctx); 1556 1557 QTAILQ_FOREACH(client, &exp->clients, next) { 1558 qio_channel_detach_aio_context(client->ioc); 1559 } 1560 1561 exp->common.ctx = NULL; 1562 } 1563 1564 static void nbd_drained_begin(void *opaque) 1565 { 1566 NBDExport *exp = opaque; 1567 NBDClient *client; 1568 1569 QTAILQ_FOREACH(client, &exp->clients, next) { 1570 client->quiescing = true; 1571 } 1572 } 1573 1574 static void nbd_drained_end(void *opaque) 1575 { 1576 NBDExport *exp = opaque; 1577 NBDClient *client; 1578 1579 QTAILQ_FOREACH(client, &exp->clients, next) { 1580 client->quiescing = false; 1581 nbd_client_receive_next_request(client); 1582 } 1583 } 1584 1585 static bool nbd_drained_poll(void *opaque) 1586 { 1587 NBDExport *exp = opaque; 1588 NBDClient *client; 1589 1590 QTAILQ_FOREACH(client, &exp->clients, next) { 1591 if (client->nb_requests != 0) { 1592 /* 1593 * If there's a coroutine waiting for a request on nbd_read_eof() 1594 * enter it here so we don't depend on the client to wake it up. 1595 */ 1596 if (client->recv_coroutine != NULL && client->read_yielding) { 1597 qemu_aio_coroutine_enter(exp->common.ctx, 1598 client->recv_coroutine); 1599 } 1600 1601 return true; 1602 } 1603 } 1604 1605 return false; 1606 } 1607 1608 static void nbd_eject_notifier(Notifier *n, void *data) 1609 { 1610 NBDExport *exp = container_of(n, NBDExport, eject_notifier); 1611 1612 blk_exp_request_shutdown(&exp->common); 1613 } 1614 1615 void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk) 1616 { 1617 NBDExport *nbd_exp = container_of(exp, NBDExport, common); 1618 assert(exp->drv == &blk_exp_nbd); 1619 assert(nbd_exp->eject_notifier_blk == NULL); 1620 1621 blk_ref(blk); 1622 nbd_exp->eject_notifier_blk = blk; 1623 nbd_exp->eject_notifier.notify = nbd_eject_notifier; 1624 blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier); 1625 } 1626 1627 static const BlockDevOps nbd_block_ops = { 1628 .drained_begin = nbd_drained_begin, 1629 .drained_end = nbd_drained_end, 1630 .drained_poll = nbd_drained_poll, 1631 }; 1632 1633 static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args, 1634 Error **errp) 1635 { 1636 NBDExport *exp = container_of(blk_exp, NBDExport, common); 1637 BlockExportOptionsNbd *arg = &exp_args->u.nbd; 1638 BlockBackend *blk = blk_exp->blk; 1639 int64_t size; 1640 uint64_t perm, shared_perm; 1641 bool readonly = !exp_args->writable; 1642 bool shared = !exp_args->writable; 1643 strList *bitmaps; 1644 size_t i; 1645 int ret; 1646 1647 assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); 1648 1649 if (!nbd_server_is_running()) { 1650 error_setg(errp, "NBD server not running"); 1651 return -EINVAL; 1652 } 1653 1654 if (!arg->has_name) { 1655 arg->name = exp_args->node_name; 1656 } 1657 1658 if (strlen(arg->name) > NBD_MAX_STRING_SIZE) { 1659 error_setg(errp, "export name '%s' too long", arg->name); 1660 return -EINVAL; 1661 } 1662 1663 if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) { 1664 error_setg(errp, "description '%s' too long", arg->description); 1665 return -EINVAL; 1666 } 1667 1668 if (nbd_export_find(arg->name)) { 1669 error_setg(errp, "NBD server already has export named '%s'", arg->name); 1670 return -EEXIST; 1671 } 1672 1673 size = blk_getlength(blk); 1674 if (size < 0) { 1675 error_setg_errno(errp, -size, 1676 "Failed to determine the NBD export's length"); 1677 return size; 1678 } 1679 1680 /* Don't allow resize while the NBD server is running, otherwise we don't 1681 * care what happens with the node. */ 1682 blk_get_perm(blk, &perm, &shared_perm); 1683 ret = blk_set_perm(blk, perm, shared_perm & ~BLK_PERM_RESIZE, errp); 1684 if (ret < 0) { 1685 return ret; 1686 } 1687 1688 QTAILQ_INIT(&exp->clients); 1689 exp->name = g_strdup(arg->name); 1690 exp->description = g_strdup(arg->description); 1691 exp->nbdflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_FLUSH | 1692 NBD_FLAG_SEND_FUA | NBD_FLAG_SEND_CACHE); 1693 if (readonly) { 1694 exp->nbdflags |= NBD_FLAG_READ_ONLY; 1695 if (shared) { 1696 exp->nbdflags |= NBD_FLAG_CAN_MULTI_CONN; 1697 } 1698 } else { 1699 exp->nbdflags |= (NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_WRITE_ZEROES | 1700 NBD_FLAG_SEND_FAST_ZERO); 1701 } 1702 exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE); 1703 1704 for (bitmaps = arg->bitmaps; bitmaps; bitmaps = bitmaps->next) { 1705 exp->nr_export_bitmaps++; 1706 } 1707 exp->export_bitmaps = g_new0(BdrvDirtyBitmap *, exp->nr_export_bitmaps); 1708 for (i = 0, bitmaps = arg->bitmaps; bitmaps; 1709 i++, bitmaps = bitmaps->next) { 1710 const char *bitmap = bitmaps->value; 1711 BlockDriverState *bs = blk_bs(blk); 1712 BdrvDirtyBitmap *bm = NULL; 1713 1714 while (bs) { 1715 bm = bdrv_find_dirty_bitmap(bs, bitmap); 1716 if (bm != NULL) { 1717 break; 1718 } 1719 1720 bs = bdrv_filter_or_cow_bs(bs); 1721 } 1722 1723 if (bm == NULL) { 1724 ret = -ENOENT; 1725 error_setg(errp, "Bitmap '%s' is not found", bitmap); 1726 goto fail; 1727 } 1728 1729 if (bdrv_dirty_bitmap_check(bm, BDRV_BITMAP_ALLOW_RO, errp)) { 1730 ret = -EINVAL; 1731 goto fail; 1732 } 1733 1734 if (readonly && bdrv_is_writable(bs) && 1735 bdrv_dirty_bitmap_enabled(bm)) { 1736 ret = -EINVAL; 1737 error_setg(errp, 1738 "Enabled bitmap '%s' incompatible with readonly export", 1739 bitmap); 1740 goto fail; 1741 } 1742 1743 exp->export_bitmaps[i] = bm; 1744 assert(strlen(bitmap) <= BDRV_BITMAP_MAX_NAME_SIZE); 1745 } 1746 1747 /* Mark bitmaps busy in a separate loop, to simplify roll-back concerns. */ 1748 for (i = 0; i < exp->nr_export_bitmaps; i++) { 1749 bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], true); 1750 } 1751 1752 exp->allocation_depth = arg->allocation_depth; 1753 1754 /* 1755 * We need to inhibit request queuing in the block layer to ensure we can 1756 * be properly quiesced when entering a drained section, as our coroutines 1757 * servicing pending requests might enter blk_pread(). 1758 */ 1759 blk_set_disable_request_queuing(blk, true); 1760 1761 blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp); 1762 1763 blk_set_dev_ops(blk, &nbd_block_ops, exp); 1764 1765 QTAILQ_INSERT_TAIL(&exports, exp, next); 1766 1767 return 0; 1768 1769 fail: 1770 g_free(exp->export_bitmaps); 1771 g_free(exp->name); 1772 g_free(exp->description); 1773 return ret; 1774 } 1775 1776 NBDExport *nbd_export_find(const char *name) 1777 { 1778 NBDExport *exp; 1779 QTAILQ_FOREACH(exp, &exports, next) { 1780 if (strcmp(name, exp->name) == 0) { 1781 return exp; 1782 } 1783 } 1784 1785 return NULL; 1786 } 1787 1788 AioContext * 1789 nbd_export_aio_context(NBDExport *exp) 1790 { 1791 return exp->common.ctx; 1792 } 1793 1794 static void nbd_export_request_shutdown(BlockExport *blk_exp) 1795 { 1796 NBDExport *exp = container_of(blk_exp, NBDExport, common); 1797 NBDClient *client, *next; 1798 1799 blk_exp_ref(&exp->common); 1800 /* 1801 * TODO: Should we expand QMP NbdServerRemoveNode enum to allow a 1802 * close mode that stops advertising the export to new clients but 1803 * still permits existing clients to run to completion? Because of 1804 * that possibility, nbd_export_close() can be called more than 1805 * once on an export. 1806 */ 1807 QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) { 1808 client_close(client, true); 1809 } 1810 if (exp->name) { 1811 g_free(exp->name); 1812 exp->name = NULL; 1813 QTAILQ_REMOVE(&exports, exp, next); 1814 } 1815 blk_exp_unref(&exp->common); 1816 } 1817 1818 static void nbd_export_delete(BlockExport *blk_exp) 1819 { 1820 size_t i; 1821 NBDExport *exp = container_of(blk_exp, NBDExport, common); 1822 1823 assert(exp->name == NULL); 1824 assert(QTAILQ_EMPTY(&exp->clients)); 1825 1826 g_free(exp->description); 1827 exp->description = NULL; 1828 1829 if (exp->common.blk) { 1830 if (exp->eject_notifier_blk) { 1831 notifier_remove(&exp->eject_notifier); 1832 blk_unref(exp->eject_notifier_blk); 1833 } 1834 blk_remove_aio_context_notifier(exp->common.blk, blk_aio_attached, 1835 blk_aio_detach, exp); 1836 blk_set_disable_request_queuing(exp->common.blk, false); 1837 } 1838 1839 for (i = 0; i < exp->nr_export_bitmaps; i++) { 1840 bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], false); 1841 } 1842 } 1843 1844 const BlockExportDriver blk_exp_nbd = { 1845 .type = BLOCK_EXPORT_TYPE_NBD, 1846 .instance_size = sizeof(NBDExport), 1847 .create = nbd_export_create, 1848 .delete = nbd_export_delete, 1849 .request_shutdown = nbd_export_request_shutdown, 1850 }; 1851 1852 static int coroutine_fn nbd_co_send_iov(NBDClient *client, struct iovec *iov, 1853 unsigned niov, Error **errp) 1854 { 1855 int ret; 1856 1857 g_assert(qemu_in_coroutine()); 1858 qemu_co_mutex_lock(&client->send_lock); 1859 client->send_coroutine = qemu_coroutine_self(); 1860 1861 ret = qio_channel_writev_all(client->ioc, iov, niov, errp) < 0 ? -EIO : 0; 1862 1863 client->send_coroutine = NULL; 1864 qemu_co_mutex_unlock(&client->send_lock); 1865 1866 return ret; 1867 } 1868 1869 static inline void set_be_simple_reply(NBDSimpleReply *reply, uint64_t error, 1870 uint64_t handle) 1871 { 1872 stl_be_p(&reply->magic, NBD_SIMPLE_REPLY_MAGIC); 1873 stl_be_p(&reply->error, error); 1874 stq_be_p(&reply->handle, handle); 1875 } 1876 1877 static int nbd_co_send_simple_reply(NBDClient *client, 1878 uint64_t handle, 1879 uint32_t error, 1880 void *data, 1881 size_t len, 1882 Error **errp) 1883 { 1884 NBDSimpleReply reply; 1885 int nbd_err = system_errno_to_nbd_errno(error); 1886 struct iovec iov[] = { 1887 {.iov_base = &reply, .iov_len = sizeof(reply)}, 1888 {.iov_base = data, .iov_len = len} 1889 }; 1890 1891 trace_nbd_co_send_simple_reply(handle, nbd_err, nbd_err_lookup(nbd_err), 1892 len); 1893 set_be_simple_reply(&reply, nbd_err, handle); 1894 1895 return nbd_co_send_iov(client, iov, len ? 2 : 1, errp); 1896 } 1897 1898 static inline void set_be_chunk(NBDStructuredReplyChunk *chunk, uint16_t flags, 1899 uint16_t type, uint64_t handle, uint32_t length) 1900 { 1901 stl_be_p(&chunk->magic, NBD_STRUCTURED_REPLY_MAGIC); 1902 stw_be_p(&chunk->flags, flags); 1903 stw_be_p(&chunk->type, type); 1904 stq_be_p(&chunk->handle, handle); 1905 stl_be_p(&chunk->length, length); 1906 } 1907 1908 static int coroutine_fn nbd_co_send_structured_done(NBDClient *client, 1909 uint64_t handle, 1910 Error **errp) 1911 { 1912 NBDStructuredReplyChunk chunk; 1913 struct iovec iov[] = { 1914 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 1915 }; 1916 1917 trace_nbd_co_send_structured_done(handle); 1918 set_be_chunk(&chunk, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_NONE, handle, 0); 1919 1920 return nbd_co_send_iov(client, iov, 1, errp); 1921 } 1922 1923 static int coroutine_fn nbd_co_send_structured_read(NBDClient *client, 1924 uint64_t handle, 1925 uint64_t offset, 1926 void *data, 1927 size_t size, 1928 bool final, 1929 Error **errp) 1930 { 1931 NBDStructuredReadData chunk; 1932 struct iovec iov[] = { 1933 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 1934 {.iov_base = data, .iov_len = size} 1935 }; 1936 1937 assert(size); 1938 trace_nbd_co_send_structured_read(handle, offset, data, size); 1939 set_be_chunk(&chunk.h, final ? NBD_REPLY_FLAG_DONE : 0, 1940 NBD_REPLY_TYPE_OFFSET_DATA, handle, 1941 sizeof(chunk) - sizeof(chunk.h) + size); 1942 stq_be_p(&chunk.offset, offset); 1943 1944 return nbd_co_send_iov(client, iov, 2, errp); 1945 } 1946 1947 static int coroutine_fn nbd_co_send_structured_error(NBDClient *client, 1948 uint64_t handle, 1949 uint32_t error, 1950 const char *msg, 1951 Error **errp) 1952 { 1953 NBDStructuredError chunk; 1954 int nbd_err = system_errno_to_nbd_errno(error); 1955 struct iovec iov[] = { 1956 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 1957 {.iov_base = (char *)msg, .iov_len = msg ? strlen(msg) : 0}, 1958 }; 1959 1960 assert(nbd_err); 1961 trace_nbd_co_send_structured_error(handle, nbd_err, 1962 nbd_err_lookup(nbd_err), msg ? msg : ""); 1963 set_be_chunk(&chunk.h, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_ERROR, handle, 1964 sizeof(chunk) - sizeof(chunk.h) + iov[1].iov_len); 1965 stl_be_p(&chunk.error, nbd_err); 1966 stw_be_p(&chunk.message_length, iov[1].iov_len); 1967 1968 return nbd_co_send_iov(client, iov, 1 + !!iov[1].iov_len, errp); 1969 } 1970 1971 /* Do a sparse read and send the structured reply to the client. 1972 * Returns -errno if sending fails. bdrv_block_status_above() failure is 1973 * reported to the client, at which point this function succeeds. 1974 */ 1975 static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, 1976 uint64_t handle, 1977 uint64_t offset, 1978 uint8_t *data, 1979 size_t size, 1980 Error **errp) 1981 { 1982 int ret = 0; 1983 NBDExport *exp = client->exp; 1984 size_t progress = 0; 1985 1986 while (progress < size) { 1987 int64_t pnum; 1988 int status = bdrv_block_status_above(blk_bs(exp->common.blk), NULL, 1989 offset + progress, 1990 size - progress, &pnum, NULL, 1991 NULL); 1992 bool final; 1993 1994 if (status < 0) { 1995 char *msg = g_strdup_printf("unable to check for holes: %s", 1996 strerror(-status)); 1997 1998 ret = nbd_co_send_structured_error(client, handle, -status, msg, 1999 errp); 2000 g_free(msg); 2001 return ret; 2002 } 2003 assert(pnum && pnum <= size - progress); 2004 final = progress + pnum == size; 2005 if (status & BDRV_BLOCK_ZERO) { 2006 NBDStructuredReadHole chunk; 2007 struct iovec iov[] = { 2008 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 2009 }; 2010 2011 trace_nbd_co_send_structured_read_hole(handle, offset + progress, 2012 pnum); 2013 set_be_chunk(&chunk.h, final ? NBD_REPLY_FLAG_DONE : 0, 2014 NBD_REPLY_TYPE_OFFSET_HOLE, 2015 handle, sizeof(chunk) - sizeof(chunk.h)); 2016 stq_be_p(&chunk.offset, offset + progress); 2017 stl_be_p(&chunk.length, pnum); 2018 ret = nbd_co_send_iov(client, iov, 1, errp); 2019 } else { 2020 ret = blk_pread(exp->common.blk, offset + progress, 2021 data + progress, pnum); 2022 if (ret < 0) { 2023 error_setg_errno(errp, -ret, "reading from file failed"); 2024 break; 2025 } 2026 ret = nbd_co_send_structured_read(client, handle, offset + progress, 2027 data + progress, pnum, final, 2028 errp); 2029 } 2030 2031 if (ret < 0) { 2032 break; 2033 } 2034 progress += pnum; 2035 } 2036 return ret; 2037 } 2038 2039 typedef struct NBDExtentArray { 2040 NBDExtent *extents; 2041 unsigned int nb_alloc; 2042 unsigned int count; 2043 uint64_t total_length; 2044 bool can_add; 2045 bool converted_to_be; 2046 } NBDExtentArray; 2047 2048 static NBDExtentArray *nbd_extent_array_new(unsigned int nb_alloc) 2049 { 2050 NBDExtentArray *ea = g_new0(NBDExtentArray, 1); 2051 2052 ea->nb_alloc = nb_alloc; 2053 ea->extents = g_new(NBDExtent, nb_alloc); 2054 ea->can_add = true; 2055 2056 return ea; 2057 } 2058 2059 static void nbd_extent_array_free(NBDExtentArray *ea) 2060 { 2061 g_free(ea->extents); 2062 g_free(ea); 2063 } 2064 G_DEFINE_AUTOPTR_CLEANUP_FUNC(NBDExtentArray, nbd_extent_array_free); 2065 2066 /* Further modifications of the array after conversion are abandoned */ 2067 static void nbd_extent_array_convert_to_be(NBDExtentArray *ea) 2068 { 2069 int i; 2070 2071 assert(!ea->converted_to_be); 2072 ea->can_add = false; 2073 ea->converted_to_be = true; 2074 2075 for (i = 0; i < ea->count; i++) { 2076 ea->extents[i].flags = cpu_to_be32(ea->extents[i].flags); 2077 ea->extents[i].length = cpu_to_be32(ea->extents[i].length); 2078 } 2079 } 2080 2081 /* 2082 * Add extent to NBDExtentArray. If extent can't be added (no available space), 2083 * return -1. 2084 * For safety, when returning -1 for the first time, .can_add is set to false, 2085 * further call to nbd_extent_array_add() will crash. 2086 * (to avoid the situation, when after failing to add an extent (returned -1), 2087 * user miss this failure and add another extent, which is successfully added 2088 * (array is full, but new extent may be squashed into the last one), then we 2089 * have invalid array with skipped extent) 2090 */ 2091 static int nbd_extent_array_add(NBDExtentArray *ea, 2092 uint32_t length, uint32_t flags) 2093 { 2094 assert(ea->can_add); 2095 2096 if (!length) { 2097 return 0; 2098 } 2099 2100 /* Extend previous extent if flags are the same */ 2101 if (ea->count > 0 && flags == ea->extents[ea->count - 1].flags) { 2102 uint64_t sum = (uint64_t)length + ea->extents[ea->count - 1].length; 2103 2104 if (sum <= UINT32_MAX) { 2105 ea->extents[ea->count - 1].length = sum; 2106 ea->total_length += length; 2107 return 0; 2108 } 2109 } 2110 2111 if (ea->count >= ea->nb_alloc) { 2112 ea->can_add = false; 2113 return -1; 2114 } 2115 2116 ea->total_length += length; 2117 ea->extents[ea->count] = (NBDExtent) {.length = length, .flags = flags}; 2118 ea->count++; 2119 2120 return 0; 2121 } 2122 2123 static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset, 2124 uint64_t bytes, NBDExtentArray *ea) 2125 { 2126 while (bytes) { 2127 uint32_t flags; 2128 int64_t num; 2129 int ret = bdrv_block_status_above(bs, NULL, offset, bytes, &num, 2130 NULL, NULL); 2131 2132 if (ret < 0) { 2133 return ret; 2134 } 2135 2136 flags = (ret & BDRV_BLOCK_DATA ? 0 : NBD_STATE_HOLE) | 2137 (ret & BDRV_BLOCK_ZERO ? NBD_STATE_ZERO : 0); 2138 2139 if (nbd_extent_array_add(ea, num, flags) < 0) { 2140 return 0; 2141 } 2142 2143 offset += num; 2144 bytes -= num; 2145 } 2146 2147 return 0; 2148 } 2149 2150 static int blockalloc_to_extents(BlockDriverState *bs, uint64_t offset, 2151 uint64_t bytes, NBDExtentArray *ea) 2152 { 2153 while (bytes) { 2154 int64_t num; 2155 int ret = bdrv_is_allocated_above(bs, NULL, false, offset, bytes, 2156 &num); 2157 2158 if (ret < 0) { 2159 return ret; 2160 } 2161 2162 if (nbd_extent_array_add(ea, num, ret) < 0) { 2163 return 0; 2164 } 2165 2166 offset += num; 2167 bytes -= num; 2168 } 2169 2170 return 0; 2171 } 2172 2173 /* 2174 * nbd_co_send_extents 2175 * 2176 * @ea is converted to BE by the function 2177 * @last controls whether NBD_REPLY_FLAG_DONE is sent. 2178 */ 2179 static int nbd_co_send_extents(NBDClient *client, uint64_t handle, 2180 NBDExtentArray *ea, 2181 bool last, uint32_t context_id, Error **errp) 2182 { 2183 NBDStructuredMeta chunk; 2184 struct iovec iov[] = { 2185 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 2186 {.iov_base = ea->extents, .iov_len = ea->count * sizeof(ea->extents[0])} 2187 }; 2188 2189 nbd_extent_array_convert_to_be(ea); 2190 2191 trace_nbd_co_send_extents(handle, ea->count, context_id, ea->total_length, 2192 last); 2193 set_be_chunk(&chunk.h, last ? NBD_REPLY_FLAG_DONE : 0, 2194 NBD_REPLY_TYPE_BLOCK_STATUS, 2195 handle, sizeof(chunk) - sizeof(chunk.h) + iov[1].iov_len); 2196 stl_be_p(&chunk.context_id, context_id); 2197 2198 return nbd_co_send_iov(client, iov, 2, errp); 2199 } 2200 2201 /* Get block status from the exported device and send it to the client */ 2202 static int nbd_co_send_block_status(NBDClient *client, uint64_t handle, 2203 BlockDriverState *bs, uint64_t offset, 2204 uint32_t length, bool dont_fragment, 2205 bool last, uint32_t context_id, 2206 Error **errp) 2207 { 2208 int ret; 2209 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS; 2210 g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents); 2211 2212 if (context_id == NBD_META_ID_BASE_ALLOCATION) { 2213 ret = blockstatus_to_extents(bs, offset, length, ea); 2214 } else { 2215 ret = blockalloc_to_extents(bs, offset, length, ea); 2216 } 2217 if (ret < 0) { 2218 return nbd_co_send_structured_error( 2219 client, handle, -ret, "can't get block status", errp); 2220 } 2221 2222 return nbd_co_send_extents(client, handle, ea, last, context_id, errp); 2223 } 2224 2225 /* Populate @ea from a dirty bitmap. */ 2226 static void bitmap_to_extents(BdrvDirtyBitmap *bitmap, 2227 uint64_t offset, uint64_t length, 2228 NBDExtentArray *es) 2229 { 2230 int64_t start, dirty_start, dirty_count; 2231 int64_t end = offset + length; 2232 bool full = false; 2233 2234 bdrv_dirty_bitmap_lock(bitmap); 2235 2236 for (start = offset; 2237 bdrv_dirty_bitmap_next_dirty_area(bitmap, start, end, INT32_MAX, 2238 &dirty_start, &dirty_count); 2239 start = dirty_start + dirty_count) 2240 { 2241 if ((nbd_extent_array_add(es, dirty_start - start, 0) < 0) || 2242 (nbd_extent_array_add(es, dirty_count, NBD_STATE_DIRTY) < 0)) 2243 { 2244 full = true; 2245 break; 2246 } 2247 } 2248 2249 if (!full) { 2250 /* last non dirty extent, nothing to do if array is now full */ 2251 (void) nbd_extent_array_add(es, end - start, 0); 2252 } 2253 2254 bdrv_dirty_bitmap_unlock(bitmap); 2255 } 2256 2257 static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle, 2258 BdrvDirtyBitmap *bitmap, uint64_t offset, 2259 uint32_t length, bool dont_fragment, bool last, 2260 uint32_t context_id, Error **errp) 2261 { 2262 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS; 2263 g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents); 2264 2265 bitmap_to_extents(bitmap, offset, length, ea); 2266 2267 return nbd_co_send_extents(client, handle, ea, last, context_id, errp); 2268 } 2269 2270 /* nbd_co_receive_request 2271 * Collect a client request. Return 0 if request looks valid, -EIO to drop 2272 * connection right away, -EAGAIN to indicate we were interrupted and the 2273 * channel should be quiesced, and any other negative value to report an error 2274 * to the client (although the caller may still need to disconnect after 2275 * reporting the error). 2276 */ 2277 static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, 2278 Error **errp) 2279 { 2280 NBDClient *client = req->client; 2281 int valid_flags; 2282 int ret; 2283 2284 g_assert(qemu_in_coroutine()); 2285 assert(client->recv_coroutine == qemu_coroutine_self()); 2286 ret = nbd_receive_request(client, request, errp); 2287 if (ret < 0) { 2288 return ret; 2289 } 2290 2291 trace_nbd_co_receive_request_decode_type(request->handle, request->type, 2292 nbd_cmd_lookup(request->type)); 2293 2294 if (request->type != NBD_CMD_WRITE) { 2295 /* No payload, we are ready to read the next request. */ 2296 req->complete = true; 2297 } 2298 2299 if (request->type == NBD_CMD_DISC) { 2300 /* Special case: we're going to disconnect without a reply, 2301 * whether or not flags, from, or len are bogus */ 2302 return -EIO; 2303 } 2304 2305 if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE || 2306 request->type == NBD_CMD_CACHE) 2307 { 2308 if (request->len > NBD_MAX_BUFFER_SIZE) { 2309 error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)", 2310 request->len, NBD_MAX_BUFFER_SIZE); 2311 return -EINVAL; 2312 } 2313 2314 if (request->type != NBD_CMD_CACHE) { 2315 req->data = blk_try_blockalign(client->exp->common.blk, 2316 request->len); 2317 if (req->data == NULL) { 2318 error_setg(errp, "No memory"); 2319 return -ENOMEM; 2320 } 2321 } 2322 } 2323 2324 if (request->type == NBD_CMD_WRITE) { 2325 if (nbd_read(client->ioc, req->data, request->len, "CMD_WRITE data", 2326 errp) < 0) 2327 { 2328 return -EIO; 2329 } 2330 req->complete = true; 2331 2332 trace_nbd_co_receive_request_payload_received(request->handle, 2333 request->len); 2334 } 2335 2336 /* Sanity checks. */ 2337 if (client->exp->nbdflags & NBD_FLAG_READ_ONLY && 2338 (request->type == NBD_CMD_WRITE || 2339 request->type == NBD_CMD_WRITE_ZEROES || 2340 request->type == NBD_CMD_TRIM)) { 2341 error_setg(errp, "Export is read-only"); 2342 return -EROFS; 2343 } 2344 if (request->from > client->exp->size || 2345 request->len > client->exp->size - request->from) { 2346 error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32 2347 ", Size: %" PRIu64, request->from, request->len, 2348 client->exp->size); 2349 return (request->type == NBD_CMD_WRITE || 2350 request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL; 2351 } 2352 if (client->check_align && !QEMU_IS_ALIGNED(request->from | request->len, 2353 client->check_align)) { 2354 /* 2355 * The block layer gracefully handles unaligned requests, but 2356 * it's still worth tracing client non-compliance 2357 */ 2358 trace_nbd_co_receive_align_compliance(nbd_cmd_lookup(request->type), 2359 request->from, 2360 request->len, 2361 client->check_align); 2362 } 2363 valid_flags = NBD_CMD_FLAG_FUA; 2364 if (request->type == NBD_CMD_READ && client->structured_reply) { 2365 valid_flags |= NBD_CMD_FLAG_DF; 2366 } else if (request->type == NBD_CMD_WRITE_ZEROES) { 2367 valid_flags |= NBD_CMD_FLAG_NO_HOLE | NBD_CMD_FLAG_FAST_ZERO; 2368 } else if (request->type == NBD_CMD_BLOCK_STATUS) { 2369 valid_flags |= NBD_CMD_FLAG_REQ_ONE; 2370 } 2371 if (request->flags & ~valid_flags) { 2372 error_setg(errp, "unsupported flags for command %s (got 0x%x)", 2373 nbd_cmd_lookup(request->type), request->flags); 2374 return -EINVAL; 2375 } 2376 2377 return 0; 2378 } 2379 2380 /* Send simple reply without a payload, or a structured error 2381 * @error_msg is ignored if @ret >= 0 2382 * Returns 0 if connection is still live, -errno on failure to talk to client 2383 */ 2384 static coroutine_fn int nbd_send_generic_reply(NBDClient *client, 2385 uint64_t handle, 2386 int ret, 2387 const char *error_msg, 2388 Error **errp) 2389 { 2390 if (client->structured_reply && ret < 0) { 2391 return nbd_co_send_structured_error(client, handle, -ret, error_msg, 2392 errp); 2393 } else { 2394 return nbd_co_send_simple_reply(client, handle, ret < 0 ? -ret : 0, 2395 NULL, 0, errp); 2396 } 2397 } 2398 2399 /* Handle NBD_CMD_READ request. 2400 * Return -errno if sending fails. Other errors are reported directly to the 2401 * client as an error reply. */ 2402 static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, 2403 uint8_t *data, Error **errp) 2404 { 2405 int ret; 2406 NBDExport *exp = client->exp; 2407 2408 assert(request->type == NBD_CMD_READ); 2409 2410 /* XXX: NBD Protocol only documents use of FUA with WRITE */ 2411 if (request->flags & NBD_CMD_FLAG_FUA) { 2412 ret = blk_co_flush(exp->common.blk); 2413 if (ret < 0) { 2414 return nbd_send_generic_reply(client, request->handle, ret, 2415 "flush failed", errp); 2416 } 2417 } 2418 2419 if (client->structured_reply && !(request->flags & NBD_CMD_FLAG_DF) && 2420 request->len) 2421 { 2422 return nbd_co_send_sparse_read(client, request->handle, request->from, 2423 data, request->len, errp); 2424 } 2425 2426 ret = blk_pread(exp->common.blk, request->from, data, request->len); 2427 if (ret < 0) { 2428 return nbd_send_generic_reply(client, request->handle, ret, 2429 "reading from file failed", errp); 2430 } 2431 2432 if (client->structured_reply) { 2433 if (request->len) { 2434 return nbd_co_send_structured_read(client, request->handle, 2435 request->from, data, 2436 request->len, true, errp); 2437 } else { 2438 return nbd_co_send_structured_done(client, request->handle, errp); 2439 } 2440 } else { 2441 return nbd_co_send_simple_reply(client, request->handle, 0, 2442 data, request->len, errp); 2443 } 2444 } 2445 2446 /* 2447 * nbd_do_cmd_cache 2448 * 2449 * Handle NBD_CMD_CACHE request. 2450 * Return -errno if sending fails. Other errors are reported directly to the 2451 * client as an error reply. 2452 */ 2453 static coroutine_fn int nbd_do_cmd_cache(NBDClient *client, NBDRequest *request, 2454 Error **errp) 2455 { 2456 int ret; 2457 NBDExport *exp = client->exp; 2458 2459 assert(request->type == NBD_CMD_CACHE); 2460 2461 ret = blk_co_preadv(exp->common.blk, request->from, request->len, 2462 NULL, BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH); 2463 2464 return nbd_send_generic_reply(client, request->handle, ret, 2465 "caching data failed", errp); 2466 } 2467 2468 /* Handle NBD request. 2469 * Return -errno if sending fails. Other errors are reported directly to the 2470 * client as an error reply. */ 2471 static coroutine_fn int nbd_handle_request(NBDClient *client, 2472 NBDRequest *request, 2473 uint8_t *data, Error **errp) 2474 { 2475 int ret; 2476 int flags; 2477 NBDExport *exp = client->exp; 2478 char *msg; 2479 size_t i; 2480 2481 switch (request->type) { 2482 case NBD_CMD_CACHE: 2483 return nbd_do_cmd_cache(client, request, errp); 2484 2485 case NBD_CMD_READ: 2486 return nbd_do_cmd_read(client, request, data, errp); 2487 2488 case NBD_CMD_WRITE: 2489 flags = 0; 2490 if (request->flags & NBD_CMD_FLAG_FUA) { 2491 flags |= BDRV_REQ_FUA; 2492 } 2493 ret = blk_pwrite(exp->common.blk, request->from, data, request->len, 2494 flags); 2495 return nbd_send_generic_reply(client, request->handle, ret, 2496 "writing to file failed", errp); 2497 2498 case NBD_CMD_WRITE_ZEROES: 2499 flags = 0; 2500 if (request->flags & NBD_CMD_FLAG_FUA) { 2501 flags |= BDRV_REQ_FUA; 2502 } 2503 if (!(request->flags & NBD_CMD_FLAG_NO_HOLE)) { 2504 flags |= BDRV_REQ_MAY_UNMAP; 2505 } 2506 if (request->flags & NBD_CMD_FLAG_FAST_ZERO) { 2507 flags |= BDRV_REQ_NO_FALLBACK; 2508 } 2509 ret = 0; 2510 /* FIXME simplify this when blk_pwrite_zeroes switches to 64-bit */ 2511 while (ret >= 0 && request->len) { 2512 int align = client->check_align ?: 1; 2513 int len = MIN(request->len, QEMU_ALIGN_DOWN(BDRV_REQUEST_MAX_BYTES, 2514 align)); 2515 ret = blk_pwrite_zeroes(exp->common.blk, request->from, len, flags); 2516 request->len -= len; 2517 request->from += len; 2518 } 2519 return nbd_send_generic_reply(client, request->handle, ret, 2520 "writing to file failed", errp); 2521 2522 case NBD_CMD_DISC: 2523 /* unreachable, thanks to special case in nbd_co_receive_request() */ 2524 abort(); 2525 2526 case NBD_CMD_FLUSH: 2527 ret = blk_co_flush(exp->common.blk); 2528 return nbd_send_generic_reply(client, request->handle, ret, 2529 "flush failed", errp); 2530 2531 case NBD_CMD_TRIM: 2532 ret = 0; 2533 /* FIXME simplify this when blk_co_pdiscard switches to 64-bit */ 2534 while (ret >= 0 && request->len) { 2535 int align = client->check_align ?: 1; 2536 int len = MIN(request->len, QEMU_ALIGN_DOWN(BDRV_REQUEST_MAX_BYTES, 2537 align)); 2538 ret = blk_co_pdiscard(exp->common.blk, request->from, len); 2539 request->len -= len; 2540 request->from += len; 2541 } 2542 if (ret >= 0 && request->flags & NBD_CMD_FLAG_FUA) { 2543 ret = blk_co_flush(exp->common.blk); 2544 } 2545 return nbd_send_generic_reply(client, request->handle, ret, 2546 "discard failed", errp); 2547 2548 case NBD_CMD_BLOCK_STATUS: 2549 if (!request->len) { 2550 return nbd_send_generic_reply(client, request->handle, -EINVAL, 2551 "need non-zero length", errp); 2552 } 2553 if (client->export_meta.count) { 2554 bool dont_fragment = request->flags & NBD_CMD_FLAG_REQ_ONE; 2555 int contexts_remaining = client->export_meta.count; 2556 2557 if (client->export_meta.base_allocation) { 2558 ret = nbd_co_send_block_status(client, request->handle, 2559 blk_bs(exp->common.blk), 2560 request->from, 2561 request->len, dont_fragment, 2562 !--contexts_remaining, 2563 NBD_META_ID_BASE_ALLOCATION, 2564 errp); 2565 if (ret < 0) { 2566 return ret; 2567 } 2568 } 2569 2570 if (client->export_meta.allocation_depth) { 2571 ret = nbd_co_send_block_status(client, request->handle, 2572 blk_bs(exp->common.blk), 2573 request->from, request->len, 2574 dont_fragment, 2575 !--contexts_remaining, 2576 NBD_META_ID_ALLOCATION_DEPTH, 2577 errp); 2578 if (ret < 0) { 2579 return ret; 2580 } 2581 } 2582 2583 for (i = 0; i < client->exp->nr_export_bitmaps; i++) { 2584 if (!client->export_meta.bitmaps[i]) { 2585 continue; 2586 } 2587 ret = nbd_co_send_bitmap(client, request->handle, 2588 client->exp->export_bitmaps[i], 2589 request->from, request->len, 2590 dont_fragment, !--contexts_remaining, 2591 NBD_META_ID_DIRTY_BITMAP + i, errp); 2592 if (ret < 0) { 2593 return ret; 2594 } 2595 } 2596 2597 assert(!contexts_remaining); 2598 2599 return 0; 2600 } else { 2601 return nbd_send_generic_reply(client, request->handle, -EINVAL, 2602 "CMD_BLOCK_STATUS not negotiated", 2603 errp); 2604 } 2605 2606 default: 2607 msg = g_strdup_printf("invalid request type (%" PRIu32 ") received", 2608 request->type); 2609 ret = nbd_send_generic_reply(client, request->handle, -EINVAL, msg, 2610 errp); 2611 g_free(msg); 2612 return ret; 2613 } 2614 } 2615 2616 /* Owns a reference to the NBDClient passed as opaque. */ 2617 static coroutine_fn void nbd_trip(void *opaque) 2618 { 2619 NBDClient *client = opaque; 2620 NBDRequestData *req; 2621 NBDRequest request = { 0 }; /* GCC thinks it can be used uninitialized */ 2622 int ret; 2623 Error *local_err = NULL; 2624 2625 trace_nbd_trip(); 2626 if (client->closing) { 2627 nbd_client_put(client); 2628 return; 2629 } 2630 2631 if (client->quiescing) { 2632 /* 2633 * We're switching between AIO contexts. Don't attempt to receive a new 2634 * request and kick the main context which may be waiting for us. 2635 */ 2636 nbd_client_put(client); 2637 client->recv_coroutine = NULL; 2638 aio_wait_kick(); 2639 return; 2640 } 2641 2642 req = nbd_request_get(client); 2643 ret = nbd_co_receive_request(req, &request, &local_err); 2644 client->recv_coroutine = NULL; 2645 2646 if (client->closing) { 2647 /* 2648 * The client may be closed when we are blocked in 2649 * nbd_co_receive_request() 2650 */ 2651 goto done; 2652 } 2653 2654 if (ret == -EAGAIN) { 2655 assert(client->quiescing); 2656 goto done; 2657 } 2658 2659 nbd_client_receive_next_request(client); 2660 if (ret == -EIO) { 2661 goto disconnect; 2662 } 2663 2664 if (ret < 0) { 2665 /* It wans't -EIO, so, according to nbd_co_receive_request() 2666 * semantics, we should return the error to the client. */ 2667 Error *export_err = local_err; 2668 2669 local_err = NULL; 2670 ret = nbd_send_generic_reply(client, request.handle, -EINVAL, 2671 error_get_pretty(export_err), &local_err); 2672 error_free(export_err); 2673 } else { 2674 ret = nbd_handle_request(client, &request, req->data, &local_err); 2675 } 2676 if (ret < 0) { 2677 error_prepend(&local_err, "Failed to send reply: "); 2678 goto disconnect; 2679 } 2680 2681 /* We must disconnect after NBD_CMD_WRITE if we did not 2682 * read the payload. 2683 */ 2684 if (!req->complete) { 2685 error_setg(&local_err, "Request handling failed in intermediate state"); 2686 goto disconnect; 2687 } 2688 2689 done: 2690 nbd_request_put(req); 2691 nbd_client_put(client); 2692 return; 2693 2694 disconnect: 2695 if (local_err) { 2696 error_reportf_err(local_err, "Disconnect client, due to: "); 2697 } 2698 nbd_request_put(req); 2699 client_close(client, true); 2700 nbd_client_put(client); 2701 } 2702 2703 static void nbd_client_receive_next_request(NBDClient *client) 2704 { 2705 if (!client->recv_coroutine && client->nb_requests < MAX_NBD_REQUESTS && 2706 !client->quiescing) { 2707 nbd_client_get(client); 2708 client->recv_coroutine = qemu_coroutine_create(nbd_trip, client); 2709 aio_co_schedule(client->exp->common.ctx, client->recv_coroutine); 2710 } 2711 } 2712 2713 static coroutine_fn void nbd_co_client_start(void *opaque) 2714 { 2715 NBDClient *client = opaque; 2716 Error *local_err = NULL; 2717 2718 qemu_co_mutex_init(&client->send_lock); 2719 2720 if (nbd_negotiate(client, &local_err)) { 2721 if (local_err) { 2722 error_report_err(local_err); 2723 } 2724 client_close(client, false); 2725 return; 2726 } 2727 2728 nbd_client_receive_next_request(client); 2729 } 2730 2731 /* 2732 * Create a new client listener using the given channel @sioc. 2733 * Begin servicing it in a coroutine. When the connection closes, call 2734 * @close_fn with an indication of whether the client completed negotiation. 2735 */ 2736 void nbd_client_new(QIOChannelSocket *sioc, 2737 QCryptoTLSCreds *tlscreds, 2738 const char *tlsauthz, 2739 void (*close_fn)(NBDClient *, bool)) 2740 { 2741 NBDClient *client; 2742 Coroutine *co; 2743 2744 client = g_new0(NBDClient, 1); 2745 client->refcount = 1; 2746 client->tlscreds = tlscreds; 2747 if (tlscreds) { 2748 object_ref(OBJECT(client->tlscreds)); 2749 } 2750 client->tlsauthz = g_strdup(tlsauthz); 2751 client->sioc = sioc; 2752 object_ref(OBJECT(client->sioc)); 2753 client->ioc = QIO_CHANNEL(sioc); 2754 object_ref(OBJECT(client->ioc)); 2755 client->close_fn = close_fn; 2756 2757 co = qemu_coroutine_create(nbd_co_client_start, client); 2758 qemu_coroutine_enter(co); 2759 } 2760