1 /* 2 * Copyright Red Hat 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/block_int.h" 23 #include "block/export.h" 24 #include "block/dirty-bitmap.h" 25 #include "qapi/error.h" 26 #include "qemu/queue.h" 27 #include "trace.h" 28 #include "nbd-internal.h" 29 #include "qemu/units.h" 30 #include "qemu/memalign.h" 31 32 #define NBD_META_ID_BASE_ALLOCATION 0 33 #define NBD_META_ID_ALLOCATION_DEPTH 1 34 /* Dirty bitmaps use 'NBD_META_ID_DIRTY_BITMAP + i', so keep this id last. */ 35 #define NBD_META_ID_DIRTY_BITMAP 2 36 37 /* 38 * NBD_MAX_BLOCK_STATUS_EXTENTS: 1 MiB of extents data. An empirical 39 * constant. If an increase is needed, note that the NBD protocol 40 * recommends no larger than 32 mb, so that the client won't consider 41 * the reply as a denial of service attack. 42 */ 43 #define NBD_MAX_BLOCK_STATUS_EXTENTS (1 * MiB / 8) 44 45 static int system_errno_to_nbd_errno(int err) 46 { 47 switch (err) { 48 case 0: 49 return NBD_SUCCESS; 50 case EPERM: 51 case EROFS: 52 return NBD_EPERM; 53 case EIO: 54 return NBD_EIO; 55 case ENOMEM: 56 return NBD_ENOMEM; 57 #ifdef EDQUOT 58 case EDQUOT: 59 #endif 60 case EFBIG: 61 case ENOSPC: 62 return NBD_ENOSPC; 63 case EOVERFLOW: 64 return NBD_EOVERFLOW; 65 case ENOTSUP: 66 #if ENOTSUP != EOPNOTSUPP 67 case EOPNOTSUPP: 68 #endif 69 return NBD_ENOTSUP; 70 case ESHUTDOWN: 71 return NBD_ESHUTDOWN; 72 case EINVAL: 73 default: 74 return NBD_EINVAL; 75 } 76 } 77 78 /* Definitions for opaque data types */ 79 80 typedef struct NBDRequestData NBDRequestData; 81 82 struct NBDRequestData { 83 NBDClient *client; 84 uint8_t *data; 85 bool complete; 86 }; 87 88 struct NBDExport { 89 BlockExport common; 90 91 char *name; 92 char *description; 93 uint64_t size; 94 uint16_t nbdflags; 95 QTAILQ_HEAD(, NBDClient) clients; 96 QTAILQ_ENTRY(NBDExport) next; 97 98 BlockBackend *eject_notifier_blk; 99 Notifier eject_notifier; 100 101 bool allocation_depth; 102 BdrvDirtyBitmap **export_bitmaps; 103 size_t nr_export_bitmaps; 104 }; 105 106 static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports); 107 108 /* NBDExportMetaContexts represents a list of contexts to be exported, 109 * as selected by NBD_OPT_SET_META_CONTEXT. Also used for 110 * NBD_OPT_LIST_META_CONTEXT. */ 111 typedef struct NBDExportMetaContexts { 112 NBDExport *exp; 113 size_t count; /* number of negotiated contexts */ 114 bool base_allocation; /* export base:allocation context (block status) */ 115 bool allocation_depth; /* export qemu:allocation-depth */ 116 bool *bitmaps; /* 117 * export qemu:dirty-bitmap:<export bitmap name>, 118 * sized by exp->nr_export_bitmaps 119 */ 120 } NBDExportMetaContexts; 121 122 struct NBDClient { 123 int refcount; 124 void (*close_fn)(NBDClient *client, bool negotiated); 125 126 NBDExport *exp; 127 QCryptoTLSCreds *tlscreds; 128 char *tlsauthz; 129 QIOChannelSocket *sioc; /* The underlying data channel */ 130 QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */ 131 132 Coroutine *recv_coroutine; 133 134 CoMutex send_lock; 135 Coroutine *send_coroutine; 136 137 bool read_yielding; 138 bool quiescing; 139 140 QTAILQ_ENTRY(NBDClient) next; 141 int nb_requests; 142 bool closing; 143 144 uint32_t check_align; /* If non-zero, check for aligned client requests */ 145 146 bool structured_reply; 147 NBDExportMetaContexts export_meta; 148 149 uint32_t opt; /* Current option being negotiated */ 150 uint32_t optlen; /* remaining length of data in ioc for the option being 151 negotiated now */ 152 }; 153 154 static void nbd_client_receive_next_request(NBDClient *client); 155 156 /* Basic flow for negotiation 157 158 Server Client 159 Negotiate 160 161 or 162 163 Server Client 164 Negotiate #1 165 Option 166 Negotiate #2 167 168 ---- 169 170 followed by 171 172 Server Client 173 Request 174 Response 175 Request 176 Response 177 ... 178 ... 179 Request (type == 2) 180 181 */ 182 183 static inline void set_be_option_rep(NBDOptionReply *rep, uint32_t option, 184 uint32_t type, uint32_t length) 185 { 186 stq_be_p(&rep->magic, NBD_REP_MAGIC); 187 stl_be_p(&rep->option, option); 188 stl_be_p(&rep->type, type); 189 stl_be_p(&rep->length, length); 190 } 191 192 /* Send a reply header, including length, but no payload. 193 * Return -errno on error, 0 on success. */ 194 static int nbd_negotiate_send_rep_len(NBDClient *client, uint32_t type, 195 uint32_t len, Error **errp) 196 { 197 NBDOptionReply rep; 198 199 trace_nbd_negotiate_send_rep_len(client->opt, nbd_opt_lookup(client->opt), 200 type, nbd_rep_lookup(type), len); 201 202 assert(len < NBD_MAX_BUFFER_SIZE); 203 204 set_be_option_rep(&rep, client->opt, type, len); 205 return nbd_write(client->ioc, &rep, sizeof(rep), errp); 206 } 207 208 /* Send a reply header with default 0 length. 209 * Return -errno on error, 0 on success. */ 210 static int nbd_negotiate_send_rep(NBDClient *client, uint32_t type, 211 Error **errp) 212 { 213 return nbd_negotiate_send_rep_len(client, type, 0, errp); 214 } 215 216 /* Send an error reply. 217 * Return -errno on error, 0 on success. */ 218 static int G_GNUC_PRINTF(4, 0) 219 nbd_negotiate_send_rep_verr(NBDClient *client, uint32_t type, 220 Error **errp, const char *fmt, va_list va) 221 { 222 ERRP_GUARD(); 223 g_autofree char *msg = NULL; 224 int ret; 225 size_t len; 226 227 msg = g_strdup_vprintf(fmt, va); 228 len = strlen(msg); 229 assert(len < NBD_MAX_STRING_SIZE); 230 trace_nbd_negotiate_send_rep_err(msg); 231 ret = nbd_negotiate_send_rep_len(client, type, len, errp); 232 if (ret < 0) { 233 return ret; 234 } 235 if (nbd_write(client->ioc, msg, len, errp) < 0) { 236 error_prepend(errp, "write failed (error message): "); 237 return -EIO; 238 } 239 240 return 0; 241 } 242 243 /* 244 * Return a malloc'd copy of @name suitable for use in an error reply. 245 */ 246 static char * 247 nbd_sanitize_name(const char *name) 248 { 249 if (strnlen(name, 80) < 80) { 250 return g_strdup(name); 251 } 252 /* XXX Should we also try to sanitize any control characters? */ 253 return g_strdup_printf("%.80s...", name); 254 } 255 256 /* Send an error reply. 257 * Return -errno on error, 0 on success. */ 258 static int G_GNUC_PRINTF(4, 5) 259 nbd_negotiate_send_rep_err(NBDClient *client, uint32_t type, 260 Error **errp, const char *fmt, ...) 261 { 262 va_list va; 263 int ret; 264 265 va_start(va, fmt); 266 ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va); 267 va_end(va); 268 return ret; 269 } 270 271 /* Drop remainder of the current option, and send a reply with the 272 * given error type and message. Return -errno on read or write 273 * failure; or 0 if connection is still live. */ 274 static int G_GNUC_PRINTF(4, 0) 275 nbd_opt_vdrop(NBDClient *client, uint32_t type, Error **errp, 276 const char *fmt, va_list va) 277 { 278 int ret = nbd_drop(client->ioc, client->optlen, errp); 279 280 client->optlen = 0; 281 if (!ret) { 282 ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va); 283 } 284 return ret; 285 } 286 287 static int G_GNUC_PRINTF(4, 5) 288 nbd_opt_drop(NBDClient *client, uint32_t type, Error **errp, 289 const char *fmt, ...) 290 { 291 int ret; 292 va_list va; 293 294 va_start(va, fmt); 295 ret = nbd_opt_vdrop(client, type, errp, fmt, va); 296 va_end(va); 297 298 return ret; 299 } 300 301 static int G_GNUC_PRINTF(3, 4) 302 nbd_opt_invalid(NBDClient *client, Error **errp, const char *fmt, ...) 303 { 304 int ret; 305 va_list va; 306 307 va_start(va, fmt); 308 ret = nbd_opt_vdrop(client, NBD_REP_ERR_INVALID, errp, fmt, va); 309 va_end(va); 310 311 return ret; 312 } 313 314 /* Read size bytes from the unparsed payload of the current option. 315 * If @check_nul, require that no NUL bytes appear in buffer. 316 * Return -errno on I/O error, 0 if option was completely handled by 317 * sending a reply about inconsistent lengths, or 1 on success. */ 318 static int nbd_opt_read(NBDClient *client, void *buffer, size_t size, 319 bool check_nul, Error **errp) 320 { 321 if (size > client->optlen) { 322 return nbd_opt_invalid(client, errp, 323 "Inconsistent lengths in option %s", 324 nbd_opt_lookup(client->opt)); 325 } 326 client->optlen -= size; 327 if (qio_channel_read_all(client->ioc, buffer, size, errp) < 0) { 328 return -EIO; 329 } 330 331 if (check_nul && strnlen(buffer, size) != size) { 332 return nbd_opt_invalid(client, errp, 333 "Unexpected embedded NUL in option %s", 334 nbd_opt_lookup(client->opt)); 335 } 336 return 1; 337 } 338 339 /* Drop size bytes from the unparsed payload of the current option. 340 * Return -errno on I/O error, 0 if option was completely handled by 341 * sending a reply about inconsistent lengths, or 1 on success. */ 342 static int nbd_opt_skip(NBDClient *client, size_t size, Error **errp) 343 { 344 if (size > client->optlen) { 345 return nbd_opt_invalid(client, errp, 346 "Inconsistent lengths in option %s", 347 nbd_opt_lookup(client->opt)); 348 } 349 client->optlen -= size; 350 return nbd_drop(client->ioc, size, errp) < 0 ? -EIO : 1; 351 } 352 353 /* nbd_opt_read_name 354 * 355 * Read a string with the format: 356 * uint32_t len (<= NBD_MAX_STRING_SIZE) 357 * len bytes string (not 0-terminated) 358 * 359 * On success, @name will be allocated. 360 * If @length is non-null, it will be set to the actual string length. 361 * 362 * Return -errno on I/O error, 0 if option was completely handled by 363 * sending a reply about inconsistent lengths, or 1 on success. 364 */ 365 static int nbd_opt_read_name(NBDClient *client, char **name, uint32_t *length, 366 Error **errp) 367 { 368 int ret; 369 uint32_t len; 370 g_autofree char *local_name = NULL; 371 372 *name = NULL; 373 ret = nbd_opt_read(client, &len, sizeof(len), false, errp); 374 if (ret <= 0) { 375 return ret; 376 } 377 len = cpu_to_be32(len); 378 379 if (len > NBD_MAX_STRING_SIZE) { 380 return nbd_opt_invalid(client, errp, 381 "Invalid name length: %" PRIu32, len); 382 } 383 384 local_name = g_malloc(len + 1); 385 ret = nbd_opt_read(client, local_name, len, true, errp); 386 if (ret <= 0) { 387 return ret; 388 } 389 local_name[len] = '\0'; 390 391 if (length) { 392 *length = len; 393 } 394 *name = g_steal_pointer(&local_name); 395 396 return 1; 397 } 398 399 /* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload. 400 * Return -errno on error, 0 on success. */ 401 static int nbd_negotiate_send_rep_list(NBDClient *client, NBDExport *exp, 402 Error **errp) 403 { 404 ERRP_GUARD(); 405 size_t name_len, desc_len; 406 uint32_t len; 407 const char *name = exp->name ? exp->name : ""; 408 const char *desc = exp->description ? exp->description : ""; 409 QIOChannel *ioc = client->ioc; 410 int ret; 411 412 trace_nbd_negotiate_send_rep_list(name, desc); 413 name_len = strlen(name); 414 desc_len = strlen(desc); 415 assert(name_len <= NBD_MAX_STRING_SIZE && desc_len <= NBD_MAX_STRING_SIZE); 416 len = name_len + desc_len + sizeof(len); 417 ret = nbd_negotiate_send_rep_len(client, NBD_REP_SERVER, len, errp); 418 if (ret < 0) { 419 return ret; 420 } 421 422 len = cpu_to_be32(name_len); 423 if (nbd_write(ioc, &len, sizeof(len), errp) < 0) { 424 error_prepend(errp, "write failed (name length): "); 425 return -EINVAL; 426 } 427 428 if (nbd_write(ioc, name, name_len, errp) < 0) { 429 error_prepend(errp, "write failed (name buffer): "); 430 return -EINVAL; 431 } 432 433 if (nbd_write(ioc, desc, desc_len, errp) < 0) { 434 error_prepend(errp, "write failed (description buffer): "); 435 return -EINVAL; 436 } 437 438 return 0; 439 } 440 441 /* Process the NBD_OPT_LIST command, with a potential series of replies. 442 * Return -errno on error, 0 on success. */ 443 static int nbd_negotiate_handle_list(NBDClient *client, Error **errp) 444 { 445 NBDExport *exp; 446 assert(client->opt == NBD_OPT_LIST); 447 448 /* For each export, send a NBD_REP_SERVER reply. */ 449 QTAILQ_FOREACH(exp, &exports, next) { 450 if (nbd_negotiate_send_rep_list(client, exp, errp)) { 451 return -EINVAL; 452 } 453 } 454 /* Finish with a NBD_REP_ACK. */ 455 return nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); 456 } 457 458 static void nbd_check_meta_export(NBDClient *client) 459 { 460 if (client->exp != client->export_meta.exp) { 461 client->export_meta.count = 0; 462 } 463 } 464 465 /* Send a reply to NBD_OPT_EXPORT_NAME. 466 * Return -errno on error, 0 on success. */ 467 static int nbd_negotiate_handle_export_name(NBDClient *client, bool no_zeroes, 468 Error **errp) 469 { 470 ERRP_GUARD(); 471 g_autofree char *name = NULL; 472 char buf[NBD_REPLY_EXPORT_NAME_SIZE] = ""; 473 size_t len; 474 int ret; 475 uint16_t myflags; 476 477 /* Client sends: 478 [20 .. xx] export name (length bytes) 479 Server replies: 480 [ 0 .. 7] size 481 [ 8 .. 9] export flags 482 [10 .. 133] reserved (0) [unless no_zeroes] 483 */ 484 trace_nbd_negotiate_handle_export_name(); 485 if (client->optlen > NBD_MAX_STRING_SIZE) { 486 error_setg(errp, "Bad length received"); 487 return -EINVAL; 488 } 489 name = g_malloc(client->optlen + 1); 490 if (nbd_read(client->ioc, name, client->optlen, "export name", errp) < 0) { 491 return -EIO; 492 } 493 name[client->optlen] = '\0'; 494 client->optlen = 0; 495 496 trace_nbd_negotiate_handle_export_name_request(name); 497 498 client->exp = nbd_export_find(name); 499 if (!client->exp) { 500 error_setg(errp, "export not found"); 501 return -EINVAL; 502 } 503 504 myflags = client->exp->nbdflags; 505 if (client->structured_reply) { 506 myflags |= NBD_FLAG_SEND_DF; 507 } 508 trace_nbd_negotiate_new_style_size_flags(client->exp->size, myflags); 509 stq_be_p(buf, client->exp->size); 510 stw_be_p(buf + 8, myflags); 511 len = no_zeroes ? 10 : sizeof(buf); 512 ret = nbd_write(client->ioc, buf, len, errp); 513 if (ret < 0) { 514 error_prepend(errp, "write failed: "); 515 return ret; 516 } 517 518 QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); 519 blk_exp_ref(&client->exp->common); 520 nbd_check_meta_export(client); 521 522 return 0; 523 } 524 525 /* Send a single NBD_REP_INFO, with a buffer @buf of @length bytes. 526 * The buffer does NOT include the info type prefix. 527 * Return -errno on error, 0 if ready to send more. */ 528 static int nbd_negotiate_send_info(NBDClient *client, 529 uint16_t info, uint32_t length, void *buf, 530 Error **errp) 531 { 532 int rc; 533 534 trace_nbd_negotiate_send_info(info, nbd_info_lookup(info), length); 535 rc = nbd_negotiate_send_rep_len(client, NBD_REP_INFO, 536 sizeof(info) + length, errp); 537 if (rc < 0) { 538 return rc; 539 } 540 info = cpu_to_be16(info); 541 if (nbd_write(client->ioc, &info, sizeof(info), errp) < 0) { 542 return -EIO; 543 } 544 if (nbd_write(client->ioc, buf, length, errp) < 0) { 545 return -EIO; 546 } 547 return 0; 548 } 549 550 /* nbd_reject_length: Handle any unexpected payload. 551 * @fatal requests that we quit talking to the client, even if we are able 552 * to successfully send an error reply. 553 * Return: 554 * -errno transmission error occurred or @fatal was requested, errp is set 555 * 0 error message successfully sent to client, errp is not set 556 */ 557 static int nbd_reject_length(NBDClient *client, bool fatal, Error **errp) 558 { 559 int ret; 560 561 assert(client->optlen); 562 ret = nbd_opt_invalid(client, errp, "option '%s' has unexpected length", 563 nbd_opt_lookup(client->opt)); 564 if (fatal && !ret) { 565 error_setg(errp, "option '%s' has unexpected length", 566 nbd_opt_lookup(client->opt)); 567 return -EINVAL; 568 } 569 return ret; 570 } 571 572 /* Handle NBD_OPT_INFO and NBD_OPT_GO. 573 * Return -errno on error, 0 if ready for next option, and 1 to move 574 * into transmission phase. */ 575 static int nbd_negotiate_handle_info(NBDClient *client, Error **errp) 576 { 577 int rc; 578 g_autofree char *name = NULL; 579 NBDExport *exp; 580 uint16_t requests; 581 uint16_t request; 582 uint32_t namelen = 0; 583 bool sendname = false; 584 bool blocksize = false; 585 uint32_t sizes[3]; 586 char buf[sizeof(uint64_t) + sizeof(uint16_t)]; 587 uint32_t check_align = 0; 588 uint16_t myflags; 589 590 /* Client sends: 591 4 bytes: L, name length (can be 0) 592 L bytes: export name 593 2 bytes: N, number of requests (can be 0) 594 N * 2 bytes: N requests 595 */ 596 rc = nbd_opt_read_name(client, &name, &namelen, errp); 597 if (rc <= 0) { 598 return rc; 599 } 600 trace_nbd_negotiate_handle_export_name_request(name); 601 602 rc = nbd_opt_read(client, &requests, sizeof(requests), false, errp); 603 if (rc <= 0) { 604 return rc; 605 } 606 requests = be16_to_cpu(requests); 607 trace_nbd_negotiate_handle_info_requests(requests); 608 while (requests--) { 609 rc = nbd_opt_read(client, &request, sizeof(request), false, errp); 610 if (rc <= 0) { 611 return rc; 612 } 613 request = be16_to_cpu(request); 614 trace_nbd_negotiate_handle_info_request(request, 615 nbd_info_lookup(request)); 616 /* We care about NBD_INFO_NAME and NBD_INFO_BLOCK_SIZE; 617 * everything else is either a request we don't know or 618 * something we send regardless of request */ 619 switch (request) { 620 case NBD_INFO_NAME: 621 sendname = true; 622 break; 623 case NBD_INFO_BLOCK_SIZE: 624 blocksize = true; 625 break; 626 } 627 } 628 if (client->optlen) { 629 return nbd_reject_length(client, false, errp); 630 } 631 632 exp = nbd_export_find(name); 633 if (!exp) { 634 g_autofree char *sane_name = nbd_sanitize_name(name); 635 636 return nbd_negotiate_send_rep_err(client, NBD_REP_ERR_UNKNOWN, 637 errp, "export '%s' not present", 638 sane_name); 639 } 640 641 /* Don't bother sending NBD_INFO_NAME unless client requested it */ 642 if (sendname) { 643 rc = nbd_negotiate_send_info(client, NBD_INFO_NAME, namelen, name, 644 errp); 645 if (rc < 0) { 646 return rc; 647 } 648 } 649 650 /* Send NBD_INFO_DESCRIPTION only if available, regardless of 651 * client request */ 652 if (exp->description) { 653 size_t len = strlen(exp->description); 654 655 assert(len <= NBD_MAX_STRING_SIZE); 656 rc = nbd_negotiate_send_info(client, NBD_INFO_DESCRIPTION, 657 len, exp->description, errp); 658 if (rc < 0) { 659 return rc; 660 } 661 } 662 663 /* Send NBD_INFO_BLOCK_SIZE always, but tweak the minimum size 664 * according to whether the client requested it, and according to 665 * whether this is OPT_INFO or OPT_GO. */ 666 /* minimum - 1 for back-compat, or actual if client will obey it. */ 667 if (client->opt == NBD_OPT_INFO || blocksize) { 668 check_align = sizes[0] = blk_get_request_alignment(exp->common.blk); 669 } else { 670 sizes[0] = 1; 671 } 672 assert(sizes[0] <= NBD_MAX_BUFFER_SIZE); 673 /* preferred - Hard-code to 4096 for now. 674 * TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */ 675 sizes[1] = MAX(4096, sizes[0]); 676 /* maximum - At most 32M, but smaller as appropriate. */ 677 sizes[2] = MIN(blk_get_max_transfer(exp->common.blk), NBD_MAX_BUFFER_SIZE); 678 trace_nbd_negotiate_handle_info_block_size(sizes[0], sizes[1], sizes[2]); 679 sizes[0] = cpu_to_be32(sizes[0]); 680 sizes[1] = cpu_to_be32(sizes[1]); 681 sizes[2] = cpu_to_be32(sizes[2]); 682 rc = nbd_negotiate_send_info(client, NBD_INFO_BLOCK_SIZE, 683 sizeof(sizes), sizes, errp); 684 if (rc < 0) { 685 return rc; 686 } 687 688 /* Send NBD_INFO_EXPORT always */ 689 myflags = exp->nbdflags; 690 if (client->structured_reply) { 691 myflags |= NBD_FLAG_SEND_DF; 692 } 693 trace_nbd_negotiate_new_style_size_flags(exp->size, myflags); 694 stq_be_p(buf, exp->size); 695 stw_be_p(buf + 8, myflags); 696 rc = nbd_negotiate_send_info(client, NBD_INFO_EXPORT, 697 sizeof(buf), buf, errp); 698 if (rc < 0) { 699 return rc; 700 } 701 702 /* 703 * If the client is just asking for NBD_OPT_INFO, but forgot to 704 * request block sizes in a situation that would impact 705 * performance, then return an error. But for NBD_OPT_GO, we 706 * tolerate all clients, regardless of alignments. 707 */ 708 if (client->opt == NBD_OPT_INFO && !blocksize && 709 blk_get_request_alignment(exp->common.blk) > 1) { 710 return nbd_negotiate_send_rep_err(client, 711 NBD_REP_ERR_BLOCK_SIZE_REQD, 712 errp, 713 "request NBD_INFO_BLOCK_SIZE to " 714 "use this export"); 715 } 716 717 /* Final reply */ 718 rc = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); 719 if (rc < 0) { 720 return rc; 721 } 722 723 if (client->opt == NBD_OPT_GO) { 724 client->exp = exp; 725 client->check_align = check_align; 726 QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); 727 blk_exp_ref(&client->exp->common); 728 nbd_check_meta_export(client); 729 rc = 1; 730 } 731 return rc; 732 } 733 734 735 /* Handle NBD_OPT_STARTTLS. Return NULL to drop connection, or else the 736 * new channel for all further (now-encrypted) communication. */ 737 static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client, 738 Error **errp) 739 { 740 QIOChannel *ioc; 741 QIOChannelTLS *tioc; 742 struct NBDTLSHandshakeData data = { 0 }; 743 744 assert(client->opt == NBD_OPT_STARTTLS); 745 746 trace_nbd_negotiate_handle_starttls(); 747 ioc = client->ioc; 748 749 if (nbd_negotiate_send_rep(client, NBD_REP_ACK, errp) < 0) { 750 return NULL; 751 } 752 753 tioc = qio_channel_tls_new_server(ioc, 754 client->tlscreds, 755 client->tlsauthz, 756 errp); 757 if (!tioc) { 758 return NULL; 759 } 760 761 qio_channel_set_name(QIO_CHANNEL(tioc), "nbd-server-tls"); 762 trace_nbd_negotiate_handle_starttls_handshake(); 763 data.loop = g_main_loop_new(g_main_context_default(), FALSE); 764 qio_channel_tls_handshake(tioc, 765 nbd_tls_handshake, 766 &data, 767 NULL, 768 NULL); 769 770 if (!data.complete) { 771 g_main_loop_run(data.loop); 772 } 773 g_main_loop_unref(data.loop); 774 if (data.error) { 775 object_unref(OBJECT(tioc)); 776 error_propagate(errp, data.error); 777 return NULL; 778 } 779 780 return QIO_CHANNEL(tioc); 781 } 782 783 /* nbd_negotiate_send_meta_context 784 * 785 * Send one chunk of reply to NBD_OPT_{LIST,SET}_META_CONTEXT 786 * 787 * For NBD_OPT_LIST_META_CONTEXT @context_id is ignored, 0 is used instead. 788 */ 789 static int nbd_negotiate_send_meta_context(NBDClient *client, 790 const char *context, 791 uint32_t context_id, 792 Error **errp) 793 { 794 NBDOptionReplyMetaContext opt; 795 struct iovec iov[] = { 796 {.iov_base = &opt, .iov_len = sizeof(opt)}, 797 {.iov_base = (void *)context, .iov_len = strlen(context)} 798 }; 799 800 assert(iov[1].iov_len <= NBD_MAX_STRING_SIZE); 801 if (client->opt == NBD_OPT_LIST_META_CONTEXT) { 802 context_id = 0; 803 } 804 805 trace_nbd_negotiate_meta_query_reply(context, context_id); 806 set_be_option_rep(&opt.h, client->opt, NBD_REP_META_CONTEXT, 807 sizeof(opt) - sizeof(opt.h) + iov[1].iov_len); 808 stl_be_p(&opt.context_id, context_id); 809 810 return qio_channel_writev_all(client->ioc, iov, 2, errp) < 0 ? -EIO : 0; 811 } 812 813 /* 814 * Return true if @query matches @pattern, or if @query is empty when 815 * the @client is performing _LIST_. 816 */ 817 static bool nbd_meta_empty_or_pattern(NBDClient *client, const char *pattern, 818 const char *query) 819 { 820 if (!*query) { 821 trace_nbd_negotiate_meta_query_parse("empty"); 822 return client->opt == NBD_OPT_LIST_META_CONTEXT; 823 } 824 if (strcmp(query, pattern) == 0) { 825 trace_nbd_negotiate_meta_query_parse(pattern); 826 return true; 827 } 828 trace_nbd_negotiate_meta_query_skip("pattern not matched"); 829 return false; 830 } 831 832 /* 833 * Return true and adjust @str in place if it begins with @prefix. 834 */ 835 static bool nbd_strshift(const char **str, const char *prefix) 836 { 837 size_t len = strlen(prefix); 838 839 if (strncmp(*str, prefix, len) == 0) { 840 *str += len; 841 return true; 842 } 843 return false; 844 } 845 846 /* nbd_meta_base_query 847 * 848 * Handle queries to 'base' namespace. For now, only the base:allocation 849 * context is available. Return true if @query has been handled. 850 */ 851 static bool nbd_meta_base_query(NBDClient *client, NBDExportMetaContexts *meta, 852 const char *query) 853 { 854 if (!nbd_strshift(&query, "base:")) { 855 return false; 856 } 857 trace_nbd_negotiate_meta_query_parse("base:"); 858 859 if (nbd_meta_empty_or_pattern(client, "allocation", query)) { 860 meta->base_allocation = true; 861 } 862 return true; 863 } 864 865 /* nbd_meta_qemu_query 866 * 867 * Handle queries to 'qemu' namespace. For now, only the qemu:dirty-bitmap: 868 * and qemu:allocation-depth contexts are available. Return true if @query 869 * has been handled. 870 */ 871 static bool nbd_meta_qemu_query(NBDClient *client, NBDExportMetaContexts *meta, 872 const char *query) 873 { 874 size_t i; 875 876 if (!nbd_strshift(&query, "qemu:")) { 877 return false; 878 } 879 trace_nbd_negotiate_meta_query_parse("qemu:"); 880 881 if (!*query) { 882 if (client->opt == NBD_OPT_LIST_META_CONTEXT) { 883 meta->allocation_depth = meta->exp->allocation_depth; 884 if (meta->exp->nr_export_bitmaps) { 885 memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps); 886 } 887 } 888 trace_nbd_negotiate_meta_query_parse("empty"); 889 return true; 890 } 891 892 if (strcmp(query, "allocation-depth") == 0) { 893 trace_nbd_negotiate_meta_query_parse("allocation-depth"); 894 meta->allocation_depth = meta->exp->allocation_depth; 895 return true; 896 } 897 898 if (nbd_strshift(&query, "dirty-bitmap:")) { 899 trace_nbd_negotiate_meta_query_parse("dirty-bitmap:"); 900 if (!*query) { 901 if (client->opt == NBD_OPT_LIST_META_CONTEXT && 902 meta->exp->nr_export_bitmaps) { 903 memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps); 904 } 905 trace_nbd_negotiate_meta_query_parse("empty"); 906 return true; 907 } 908 909 for (i = 0; i < meta->exp->nr_export_bitmaps; i++) { 910 const char *bm_name; 911 912 bm_name = bdrv_dirty_bitmap_name(meta->exp->export_bitmaps[i]); 913 if (strcmp(bm_name, query) == 0) { 914 meta->bitmaps[i] = true; 915 trace_nbd_negotiate_meta_query_parse(query); 916 return true; 917 } 918 } 919 trace_nbd_negotiate_meta_query_skip("no dirty-bitmap match"); 920 return true; 921 } 922 923 trace_nbd_negotiate_meta_query_skip("unknown qemu context"); 924 return true; 925 } 926 927 /* nbd_negotiate_meta_query 928 * 929 * Parse namespace name and call corresponding function to parse body of the 930 * query. 931 * 932 * The only supported namespaces are 'base' and 'qemu'. 933 * 934 * Return -errno on I/O error, 0 if option was completely handled by 935 * sending a reply about inconsistent lengths, or 1 on success. */ 936 static int nbd_negotiate_meta_query(NBDClient *client, 937 NBDExportMetaContexts *meta, Error **errp) 938 { 939 int ret; 940 g_autofree char *query = NULL; 941 uint32_t len; 942 943 ret = nbd_opt_read(client, &len, sizeof(len), false, errp); 944 if (ret <= 0) { 945 return ret; 946 } 947 len = cpu_to_be32(len); 948 949 if (len > NBD_MAX_STRING_SIZE) { 950 trace_nbd_negotiate_meta_query_skip("length too long"); 951 return nbd_opt_skip(client, len, errp); 952 } 953 954 query = g_malloc(len + 1); 955 ret = nbd_opt_read(client, query, len, true, errp); 956 if (ret <= 0) { 957 return ret; 958 } 959 query[len] = '\0'; 960 961 if (nbd_meta_base_query(client, meta, query)) { 962 return 1; 963 } 964 if (nbd_meta_qemu_query(client, meta, query)) { 965 return 1; 966 } 967 968 trace_nbd_negotiate_meta_query_skip("unknown namespace"); 969 return 1; 970 } 971 972 /* nbd_negotiate_meta_queries 973 * Handle NBD_OPT_LIST_META_CONTEXT and NBD_OPT_SET_META_CONTEXT 974 * 975 * Return -errno on I/O error, or 0 if option was completely handled. */ 976 static int nbd_negotiate_meta_queries(NBDClient *client, 977 NBDExportMetaContexts *meta, Error **errp) 978 { 979 int ret; 980 g_autofree char *export_name = NULL; 981 /* Mark unused to work around https://bugs.llvm.org/show_bug.cgi?id=3888 */ 982 g_autofree G_GNUC_UNUSED bool *bitmaps = NULL; 983 NBDExportMetaContexts local_meta = {0}; 984 uint32_t nb_queries; 985 size_t i; 986 size_t count = 0; 987 988 if (client->opt == NBD_OPT_SET_META_CONTEXT && !client->structured_reply) { 989 return nbd_opt_invalid(client, errp, 990 "request option '%s' when structured reply " 991 "is not negotiated", 992 nbd_opt_lookup(client->opt)); 993 } 994 995 if (client->opt == NBD_OPT_LIST_META_CONTEXT) { 996 /* Only change the caller's meta on SET. */ 997 meta = &local_meta; 998 } 999 1000 g_free(meta->bitmaps); 1001 memset(meta, 0, sizeof(*meta)); 1002 1003 ret = nbd_opt_read_name(client, &export_name, NULL, errp); 1004 if (ret <= 0) { 1005 return ret; 1006 } 1007 1008 meta->exp = nbd_export_find(export_name); 1009 if (meta->exp == NULL) { 1010 g_autofree char *sane_name = nbd_sanitize_name(export_name); 1011 1012 return nbd_opt_drop(client, NBD_REP_ERR_UNKNOWN, errp, 1013 "export '%s' not present", sane_name); 1014 } 1015 meta->bitmaps = g_new0(bool, meta->exp->nr_export_bitmaps); 1016 if (client->opt == NBD_OPT_LIST_META_CONTEXT) { 1017 bitmaps = meta->bitmaps; 1018 } 1019 1020 ret = nbd_opt_read(client, &nb_queries, sizeof(nb_queries), false, errp); 1021 if (ret <= 0) { 1022 return ret; 1023 } 1024 nb_queries = cpu_to_be32(nb_queries); 1025 trace_nbd_negotiate_meta_context(nbd_opt_lookup(client->opt), 1026 export_name, nb_queries); 1027 1028 if (client->opt == NBD_OPT_LIST_META_CONTEXT && !nb_queries) { 1029 /* enable all known contexts */ 1030 meta->base_allocation = true; 1031 meta->allocation_depth = meta->exp->allocation_depth; 1032 if (meta->exp->nr_export_bitmaps) { 1033 memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps); 1034 } 1035 } else { 1036 for (i = 0; i < nb_queries; ++i) { 1037 ret = nbd_negotiate_meta_query(client, meta, errp); 1038 if (ret <= 0) { 1039 return ret; 1040 } 1041 } 1042 } 1043 1044 if (meta->base_allocation) { 1045 ret = nbd_negotiate_send_meta_context(client, "base:allocation", 1046 NBD_META_ID_BASE_ALLOCATION, 1047 errp); 1048 if (ret < 0) { 1049 return ret; 1050 } 1051 count++; 1052 } 1053 1054 if (meta->allocation_depth) { 1055 ret = nbd_negotiate_send_meta_context(client, "qemu:allocation-depth", 1056 NBD_META_ID_ALLOCATION_DEPTH, 1057 errp); 1058 if (ret < 0) { 1059 return ret; 1060 } 1061 count++; 1062 } 1063 1064 for (i = 0; i < meta->exp->nr_export_bitmaps; i++) { 1065 const char *bm_name; 1066 g_autofree char *context = NULL; 1067 1068 if (!meta->bitmaps[i]) { 1069 continue; 1070 } 1071 1072 bm_name = bdrv_dirty_bitmap_name(meta->exp->export_bitmaps[i]); 1073 context = g_strdup_printf("qemu:dirty-bitmap:%s", bm_name); 1074 1075 ret = nbd_negotiate_send_meta_context(client, context, 1076 NBD_META_ID_DIRTY_BITMAP + i, 1077 errp); 1078 if (ret < 0) { 1079 return ret; 1080 } 1081 count++; 1082 } 1083 1084 ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); 1085 if (ret == 0) { 1086 meta->count = count; 1087 } 1088 1089 return ret; 1090 } 1091 1092 /* nbd_negotiate_options 1093 * Process all NBD_OPT_* client option commands, during fixed newstyle 1094 * negotiation. 1095 * Return: 1096 * -errno on error, errp is set 1097 * 0 on successful negotiation, errp is not set 1098 * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect, 1099 * errp is not set 1100 */ 1101 static int nbd_negotiate_options(NBDClient *client, Error **errp) 1102 { 1103 uint32_t flags; 1104 bool fixedNewstyle = false; 1105 bool no_zeroes = false; 1106 1107 /* Client sends: 1108 [ 0 .. 3] client flags 1109 1110 Then we loop until NBD_OPT_EXPORT_NAME or NBD_OPT_GO: 1111 [ 0 .. 7] NBD_OPTS_MAGIC 1112 [ 8 .. 11] NBD option 1113 [12 .. 15] Data length 1114 ... Rest of request 1115 1116 [ 0 .. 7] NBD_OPTS_MAGIC 1117 [ 8 .. 11] Second NBD option 1118 [12 .. 15] Data length 1119 ... Rest of request 1120 */ 1121 1122 if (nbd_read32(client->ioc, &flags, "flags", errp) < 0) { 1123 return -EIO; 1124 } 1125 trace_nbd_negotiate_options_flags(flags); 1126 if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) { 1127 fixedNewstyle = true; 1128 flags &= ~NBD_FLAG_C_FIXED_NEWSTYLE; 1129 } 1130 if (flags & NBD_FLAG_C_NO_ZEROES) { 1131 no_zeroes = true; 1132 flags &= ~NBD_FLAG_C_NO_ZEROES; 1133 } 1134 if (flags != 0) { 1135 error_setg(errp, "Unknown client flags 0x%" PRIx32 " received", flags); 1136 return -EINVAL; 1137 } 1138 1139 while (1) { 1140 int ret; 1141 uint32_t option, length; 1142 uint64_t magic; 1143 1144 if (nbd_read64(client->ioc, &magic, "opts magic", errp) < 0) { 1145 return -EINVAL; 1146 } 1147 trace_nbd_negotiate_options_check_magic(magic); 1148 if (magic != NBD_OPTS_MAGIC) { 1149 error_setg(errp, "Bad magic received"); 1150 return -EINVAL; 1151 } 1152 1153 if (nbd_read32(client->ioc, &option, "option", errp) < 0) { 1154 return -EINVAL; 1155 } 1156 client->opt = option; 1157 1158 if (nbd_read32(client->ioc, &length, "option length", errp) < 0) { 1159 return -EINVAL; 1160 } 1161 assert(!client->optlen); 1162 client->optlen = length; 1163 1164 if (length > NBD_MAX_BUFFER_SIZE) { 1165 error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)", 1166 length, NBD_MAX_BUFFER_SIZE); 1167 return -EINVAL; 1168 } 1169 1170 trace_nbd_negotiate_options_check_option(option, 1171 nbd_opt_lookup(option)); 1172 if (client->tlscreds && 1173 client->ioc == (QIOChannel *)client->sioc) { 1174 QIOChannel *tioc; 1175 if (!fixedNewstyle) { 1176 error_setg(errp, "Unsupported option 0x%" PRIx32, option); 1177 return -EINVAL; 1178 } 1179 switch (option) { 1180 case NBD_OPT_STARTTLS: 1181 if (length) { 1182 /* Unconditionally drop the connection if the client 1183 * can't start a TLS negotiation correctly */ 1184 return nbd_reject_length(client, true, errp); 1185 } 1186 tioc = nbd_negotiate_handle_starttls(client, errp); 1187 if (!tioc) { 1188 return -EIO; 1189 } 1190 ret = 0; 1191 object_unref(OBJECT(client->ioc)); 1192 client->ioc = tioc; 1193 break; 1194 1195 case NBD_OPT_EXPORT_NAME: 1196 /* No way to return an error to client, so drop connection */ 1197 error_setg(errp, "Option 0x%x not permitted before TLS", 1198 option); 1199 return -EINVAL; 1200 1201 default: 1202 /* Let the client keep trying, unless they asked to 1203 * quit. Always try to give an error back to the 1204 * client; but when replying to OPT_ABORT, be aware 1205 * that the client may hang up before receiving the 1206 * error, in which case we are fine ignoring the 1207 * resulting EPIPE. */ 1208 ret = nbd_opt_drop(client, NBD_REP_ERR_TLS_REQD, 1209 option == NBD_OPT_ABORT ? NULL : errp, 1210 "Option 0x%" PRIx32 1211 " not permitted before TLS", option); 1212 if (option == NBD_OPT_ABORT) { 1213 return 1; 1214 } 1215 break; 1216 } 1217 } else if (fixedNewstyle) { 1218 switch (option) { 1219 case NBD_OPT_LIST: 1220 if (length) { 1221 ret = nbd_reject_length(client, false, errp); 1222 } else { 1223 ret = nbd_negotiate_handle_list(client, errp); 1224 } 1225 break; 1226 1227 case NBD_OPT_ABORT: 1228 /* NBD spec says we must try to reply before 1229 * disconnecting, but that we must also tolerate 1230 * guests that don't wait for our reply. */ 1231 nbd_negotiate_send_rep(client, NBD_REP_ACK, NULL); 1232 return 1; 1233 1234 case NBD_OPT_EXPORT_NAME: 1235 return nbd_negotiate_handle_export_name(client, no_zeroes, 1236 errp); 1237 1238 case NBD_OPT_INFO: 1239 case NBD_OPT_GO: 1240 ret = nbd_negotiate_handle_info(client, errp); 1241 if (ret == 1) { 1242 assert(option == NBD_OPT_GO); 1243 return 0; 1244 } 1245 break; 1246 1247 case NBD_OPT_STARTTLS: 1248 if (length) { 1249 ret = nbd_reject_length(client, false, errp); 1250 } else if (client->tlscreds) { 1251 ret = nbd_negotiate_send_rep_err(client, 1252 NBD_REP_ERR_INVALID, errp, 1253 "TLS already enabled"); 1254 } else { 1255 ret = nbd_negotiate_send_rep_err(client, 1256 NBD_REP_ERR_POLICY, errp, 1257 "TLS not configured"); 1258 } 1259 break; 1260 1261 case NBD_OPT_STRUCTURED_REPLY: 1262 if (length) { 1263 ret = nbd_reject_length(client, false, errp); 1264 } else if (client->structured_reply) { 1265 ret = nbd_negotiate_send_rep_err( 1266 client, NBD_REP_ERR_INVALID, errp, 1267 "structured reply already negotiated"); 1268 } else { 1269 ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); 1270 client->structured_reply = true; 1271 } 1272 break; 1273 1274 case NBD_OPT_LIST_META_CONTEXT: 1275 case NBD_OPT_SET_META_CONTEXT: 1276 ret = nbd_negotiate_meta_queries(client, &client->export_meta, 1277 errp); 1278 break; 1279 1280 default: 1281 ret = nbd_opt_drop(client, NBD_REP_ERR_UNSUP, errp, 1282 "Unsupported option %" PRIu32 " (%s)", 1283 option, nbd_opt_lookup(option)); 1284 break; 1285 } 1286 } else { 1287 /* 1288 * If broken new-style we should drop the connection 1289 * for anything except NBD_OPT_EXPORT_NAME 1290 */ 1291 switch (option) { 1292 case NBD_OPT_EXPORT_NAME: 1293 return nbd_negotiate_handle_export_name(client, no_zeroes, 1294 errp); 1295 1296 default: 1297 error_setg(errp, "Unsupported option %" PRIu32 " (%s)", 1298 option, nbd_opt_lookup(option)); 1299 return -EINVAL; 1300 } 1301 } 1302 if (ret < 0) { 1303 return ret; 1304 } 1305 } 1306 } 1307 1308 /* nbd_negotiate 1309 * Return: 1310 * -errno on error, errp is set 1311 * 0 on successful negotiation, errp is not set 1312 * 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect, 1313 * errp is not set 1314 */ 1315 static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp) 1316 { 1317 ERRP_GUARD(); 1318 char buf[NBD_OLDSTYLE_NEGOTIATE_SIZE] = ""; 1319 int ret; 1320 1321 /* Old style negotiation header, no room for options 1322 [ 0 .. 7] passwd ("NBDMAGIC") 1323 [ 8 .. 15] magic (NBD_CLIENT_MAGIC) 1324 [16 .. 23] size 1325 [24 .. 27] export flags (zero-extended) 1326 [28 .. 151] reserved (0) 1327 1328 New style negotiation header, client can send options 1329 [ 0 .. 7] passwd ("NBDMAGIC") 1330 [ 8 .. 15] magic (NBD_OPTS_MAGIC) 1331 [16 .. 17] server flags (0) 1332 ....options sent, ending in NBD_OPT_EXPORT_NAME or NBD_OPT_GO.... 1333 */ 1334 1335 qio_channel_set_blocking(client->ioc, false, NULL); 1336 qio_channel_set_follow_coroutine_ctx(client->ioc, true); 1337 1338 trace_nbd_negotiate_begin(); 1339 memcpy(buf, "NBDMAGIC", 8); 1340 1341 stq_be_p(buf + 8, NBD_OPTS_MAGIC); 1342 stw_be_p(buf + 16, NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES); 1343 1344 if (nbd_write(client->ioc, buf, 18, errp) < 0) { 1345 error_prepend(errp, "write failed: "); 1346 return -EINVAL; 1347 } 1348 ret = nbd_negotiate_options(client, errp); 1349 if (ret != 0) { 1350 if (ret < 0) { 1351 error_prepend(errp, "option negotiation failed: "); 1352 } 1353 return ret; 1354 } 1355 1356 assert(!client->optlen); 1357 trace_nbd_negotiate_success(); 1358 1359 return 0; 1360 } 1361 1362 /* nbd_read_eof 1363 * Tries to read @size bytes from @ioc. This is a local implementation of 1364 * qio_channel_readv_all_eof. We have it here because we need it to be 1365 * interruptible and to know when the coroutine is yielding. 1366 * Returns 1 on success 1367 * 0 on eof, when no data was read (errp is not set) 1368 * negative errno on failure (errp is set) 1369 */ 1370 static inline int coroutine_fn 1371 nbd_read_eof(NBDClient *client, void *buffer, size_t size, Error **errp) 1372 { 1373 bool partial = false; 1374 1375 assert(size); 1376 while (size > 0) { 1377 struct iovec iov = { .iov_base = buffer, .iov_len = size }; 1378 ssize_t len; 1379 1380 len = qio_channel_readv(client->ioc, &iov, 1, errp); 1381 if (len == QIO_CHANNEL_ERR_BLOCK) { 1382 client->read_yielding = true; 1383 qio_channel_yield(client->ioc, G_IO_IN); 1384 client->read_yielding = false; 1385 if (client->quiescing) { 1386 return -EAGAIN; 1387 } 1388 continue; 1389 } else if (len < 0) { 1390 return -EIO; 1391 } else if (len == 0) { 1392 if (partial) { 1393 error_setg(errp, 1394 "Unexpected end-of-file before all bytes were read"); 1395 return -EIO; 1396 } else { 1397 return 0; 1398 } 1399 } 1400 1401 partial = true; 1402 size -= len; 1403 buffer = (uint8_t *) buffer + len; 1404 } 1405 return 1; 1406 } 1407 1408 static int coroutine_fn nbd_receive_request(NBDClient *client, NBDRequest *request, 1409 Error **errp) 1410 { 1411 uint8_t buf[NBD_REQUEST_SIZE]; 1412 uint32_t magic; 1413 int ret; 1414 1415 ret = nbd_read_eof(client, buf, sizeof(buf), errp); 1416 if (ret < 0) { 1417 return ret; 1418 } 1419 if (ret == 0) { 1420 return -EIO; 1421 } 1422 1423 /* Request 1424 [ 0 .. 3] magic (NBD_REQUEST_MAGIC) 1425 [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...) 1426 [ 6 .. 7] type (NBD_CMD_READ, ...) 1427 [ 8 .. 15] cookie 1428 [16 .. 23] from 1429 [24 .. 27] len 1430 */ 1431 1432 magic = ldl_be_p(buf); 1433 request->flags = lduw_be_p(buf + 4); 1434 request->type = lduw_be_p(buf + 6); 1435 request->cookie = ldq_be_p(buf + 8); 1436 request->from = ldq_be_p(buf + 16); 1437 request->len = ldl_be_p(buf + 24); 1438 1439 trace_nbd_receive_request(magic, request->flags, request->type, 1440 request->from, request->len); 1441 1442 if (magic != NBD_REQUEST_MAGIC) { 1443 error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", magic); 1444 return -EINVAL; 1445 } 1446 return 0; 1447 } 1448 1449 #define MAX_NBD_REQUESTS 16 1450 1451 void nbd_client_get(NBDClient *client) 1452 { 1453 client->refcount++; 1454 } 1455 1456 void nbd_client_put(NBDClient *client) 1457 { 1458 if (--client->refcount == 0) { 1459 /* The last reference should be dropped by client->close, 1460 * which is called by client_close. 1461 */ 1462 assert(client->closing); 1463 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 assert(client->nb_requests == 0); 1543 assert(client->recv_coroutine == NULL); 1544 assert(client->send_coroutine == NULL); 1545 } 1546 } 1547 1548 static void blk_aio_detach(void *opaque) 1549 { 1550 NBDExport *exp = opaque; 1551 1552 trace_nbd_blk_aio_detach(exp->name, exp->common.ctx); 1553 1554 exp->common.ctx = NULL; 1555 } 1556 1557 static void nbd_drained_begin(void *opaque) 1558 { 1559 NBDExport *exp = opaque; 1560 NBDClient *client; 1561 1562 QTAILQ_FOREACH(client, &exp->clients, next) { 1563 client->quiescing = true; 1564 } 1565 } 1566 1567 static void nbd_drained_end(void *opaque) 1568 { 1569 NBDExport *exp = opaque; 1570 NBDClient *client; 1571 1572 QTAILQ_FOREACH(client, &exp->clients, next) { 1573 client->quiescing = false; 1574 nbd_client_receive_next_request(client); 1575 } 1576 } 1577 1578 static bool nbd_drained_poll(void *opaque) 1579 { 1580 NBDExport *exp = opaque; 1581 NBDClient *client; 1582 1583 QTAILQ_FOREACH(client, &exp->clients, next) { 1584 if (client->nb_requests != 0) { 1585 /* 1586 * If there's a coroutine waiting for a request on nbd_read_eof() 1587 * enter it here so we don't depend on the client to wake it up. 1588 */ 1589 if (client->recv_coroutine != NULL && client->read_yielding) { 1590 qio_channel_wake_read(client->ioc); 1591 } 1592 1593 return true; 1594 } 1595 } 1596 1597 return false; 1598 } 1599 1600 static void nbd_eject_notifier(Notifier *n, void *data) 1601 { 1602 NBDExport *exp = container_of(n, NBDExport, eject_notifier); 1603 1604 blk_exp_request_shutdown(&exp->common); 1605 } 1606 1607 void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk) 1608 { 1609 NBDExport *nbd_exp = container_of(exp, NBDExport, common); 1610 assert(exp->drv == &blk_exp_nbd); 1611 assert(nbd_exp->eject_notifier_blk == NULL); 1612 1613 blk_ref(blk); 1614 nbd_exp->eject_notifier_blk = blk; 1615 nbd_exp->eject_notifier.notify = nbd_eject_notifier; 1616 blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier); 1617 } 1618 1619 static const BlockDevOps nbd_block_ops = { 1620 .drained_begin = nbd_drained_begin, 1621 .drained_end = nbd_drained_end, 1622 .drained_poll = nbd_drained_poll, 1623 }; 1624 1625 static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args, 1626 Error **errp) 1627 { 1628 NBDExport *exp = container_of(blk_exp, NBDExport, common); 1629 BlockExportOptionsNbd *arg = &exp_args->u.nbd; 1630 const char *name = arg->name ?: exp_args->node_name; 1631 BlockBackend *blk = blk_exp->blk; 1632 int64_t size; 1633 uint64_t perm, shared_perm; 1634 bool readonly = !exp_args->writable; 1635 BlockDirtyBitmapOrStrList *bitmaps; 1636 size_t i; 1637 int ret; 1638 1639 assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); 1640 1641 if (!nbd_server_is_running()) { 1642 error_setg(errp, "NBD server not running"); 1643 return -EINVAL; 1644 } 1645 1646 if (strlen(name) > NBD_MAX_STRING_SIZE) { 1647 error_setg(errp, "export name '%s' too long", name); 1648 return -EINVAL; 1649 } 1650 1651 if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) { 1652 error_setg(errp, "description '%s' too long", arg->description); 1653 return -EINVAL; 1654 } 1655 1656 if (nbd_export_find(name)) { 1657 error_setg(errp, "NBD server already has export named '%s'", name); 1658 return -EEXIST; 1659 } 1660 1661 size = blk_getlength(blk); 1662 if (size < 0) { 1663 error_setg_errno(errp, -size, 1664 "Failed to determine the NBD export's length"); 1665 return size; 1666 } 1667 1668 /* Don't allow resize while the NBD server is running, otherwise we don't 1669 * care what happens with the node. */ 1670 blk_get_perm(blk, &perm, &shared_perm); 1671 ret = blk_set_perm(blk, perm, shared_perm & ~BLK_PERM_RESIZE, errp); 1672 if (ret < 0) { 1673 return ret; 1674 } 1675 1676 QTAILQ_INIT(&exp->clients); 1677 exp->name = g_strdup(name); 1678 exp->description = g_strdup(arg->description); 1679 exp->nbdflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_FLUSH | 1680 NBD_FLAG_SEND_FUA | NBD_FLAG_SEND_CACHE); 1681 1682 if (nbd_server_max_connections() != 1) { 1683 exp->nbdflags |= NBD_FLAG_CAN_MULTI_CONN; 1684 } 1685 if (readonly) { 1686 exp->nbdflags |= NBD_FLAG_READ_ONLY; 1687 } else { 1688 exp->nbdflags |= (NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_WRITE_ZEROES | 1689 NBD_FLAG_SEND_FAST_ZERO); 1690 } 1691 exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE); 1692 1693 for (bitmaps = arg->bitmaps; bitmaps; bitmaps = bitmaps->next) { 1694 exp->nr_export_bitmaps++; 1695 } 1696 exp->export_bitmaps = g_new0(BdrvDirtyBitmap *, exp->nr_export_bitmaps); 1697 for (i = 0, bitmaps = arg->bitmaps; bitmaps; 1698 i++, bitmaps = bitmaps->next) 1699 { 1700 const char *bitmap; 1701 BlockDriverState *bs = blk_bs(blk); 1702 BdrvDirtyBitmap *bm = NULL; 1703 1704 switch (bitmaps->value->type) { 1705 case QTYPE_QSTRING: 1706 bitmap = bitmaps->value->u.local; 1707 while (bs) { 1708 bm = bdrv_find_dirty_bitmap(bs, bitmap); 1709 if (bm != NULL) { 1710 break; 1711 } 1712 1713 bs = bdrv_filter_or_cow_bs(bs); 1714 } 1715 1716 if (bm == NULL) { 1717 ret = -ENOENT; 1718 error_setg(errp, "Bitmap '%s' is not found", 1719 bitmaps->value->u.local); 1720 goto fail; 1721 } 1722 1723 if (readonly && bdrv_is_writable(bs) && 1724 bdrv_dirty_bitmap_enabled(bm)) { 1725 ret = -EINVAL; 1726 error_setg(errp, "Enabled bitmap '%s' incompatible with " 1727 "readonly export", bitmap); 1728 goto fail; 1729 } 1730 break; 1731 case QTYPE_QDICT: 1732 bitmap = bitmaps->value->u.external.name; 1733 bm = block_dirty_bitmap_lookup(bitmaps->value->u.external.node, 1734 bitmap, NULL, errp); 1735 if (!bm) { 1736 ret = -ENOENT; 1737 goto fail; 1738 } 1739 break; 1740 default: 1741 abort(); 1742 } 1743 1744 assert(bm); 1745 1746 if (bdrv_dirty_bitmap_check(bm, BDRV_BITMAP_ALLOW_RO, errp)) { 1747 ret = -EINVAL; 1748 goto fail; 1749 } 1750 1751 exp->export_bitmaps[i] = bm; 1752 assert(strlen(bitmap) <= BDRV_BITMAP_MAX_NAME_SIZE); 1753 } 1754 1755 /* Mark bitmaps busy in a separate loop, to simplify roll-back concerns. */ 1756 for (i = 0; i < exp->nr_export_bitmaps; i++) { 1757 bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], true); 1758 } 1759 1760 exp->allocation_depth = arg->allocation_depth; 1761 1762 /* 1763 * We need to inhibit request queuing in the block layer to ensure we can 1764 * be properly quiesced when entering a drained section, as our coroutines 1765 * servicing pending requests might enter blk_pread(). 1766 */ 1767 blk_set_disable_request_queuing(blk, true); 1768 1769 blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp); 1770 1771 blk_set_dev_ops(blk, &nbd_block_ops, exp); 1772 1773 QTAILQ_INSERT_TAIL(&exports, exp, next); 1774 1775 return 0; 1776 1777 fail: 1778 g_free(exp->export_bitmaps); 1779 g_free(exp->name); 1780 g_free(exp->description); 1781 return ret; 1782 } 1783 1784 NBDExport *nbd_export_find(const char *name) 1785 { 1786 NBDExport *exp; 1787 QTAILQ_FOREACH(exp, &exports, next) { 1788 if (strcmp(name, exp->name) == 0) { 1789 return exp; 1790 } 1791 } 1792 1793 return NULL; 1794 } 1795 1796 AioContext * 1797 nbd_export_aio_context(NBDExport *exp) 1798 { 1799 return exp->common.ctx; 1800 } 1801 1802 static void nbd_export_request_shutdown(BlockExport *blk_exp) 1803 { 1804 NBDExport *exp = container_of(blk_exp, NBDExport, common); 1805 NBDClient *client, *next; 1806 1807 blk_exp_ref(&exp->common); 1808 /* 1809 * TODO: Should we expand QMP NbdServerRemoveNode enum to allow a 1810 * close mode that stops advertising the export to new clients but 1811 * still permits existing clients to run to completion? Because of 1812 * that possibility, nbd_export_close() can be called more than 1813 * once on an export. 1814 */ 1815 QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) { 1816 client_close(client, true); 1817 } 1818 if (exp->name) { 1819 g_free(exp->name); 1820 exp->name = NULL; 1821 QTAILQ_REMOVE(&exports, exp, next); 1822 } 1823 blk_exp_unref(&exp->common); 1824 } 1825 1826 static void nbd_export_delete(BlockExport *blk_exp) 1827 { 1828 size_t i; 1829 NBDExport *exp = container_of(blk_exp, NBDExport, common); 1830 1831 assert(exp->name == NULL); 1832 assert(QTAILQ_EMPTY(&exp->clients)); 1833 1834 g_free(exp->description); 1835 exp->description = NULL; 1836 1837 if (exp->eject_notifier_blk) { 1838 notifier_remove(&exp->eject_notifier); 1839 blk_unref(exp->eject_notifier_blk); 1840 } 1841 blk_remove_aio_context_notifier(exp->common.blk, blk_aio_attached, 1842 blk_aio_detach, exp); 1843 blk_set_disable_request_queuing(exp->common.blk, false); 1844 1845 for (i = 0; i < exp->nr_export_bitmaps; i++) { 1846 bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], false); 1847 } 1848 } 1849 1850 const BlockExportDriver blk_exp_nbd = { 1851 .type = BLOCK_EXPORT_TYPE_NBD, 1852 .instance_size = sizeof(NBDExport), 1853 .create = nbd_export_create, 1854 .delete = nbd_export_delete, 1855 .request_shutdown = nbd_export_request_shutdown, 1856 }; 1857 1858 static int coroutine_fn nbd_co_send_iov(NBDClient *client, struct iovec *iov, 1859 unsigned niov, Error **errp) 1860 { 1861 int ret; 1862 1863 g_assert(qemu_in_coroutine()); 1864 qemu_co_mutex_lock(&client->send_lock); 1865 client->send_coroutine = qemu_coroutine_self(); 1866 1867 ret = qio_channel_writev_all(client->ioc, iov, niov, errp) < 0 ? -EIO : 0; 1868 1869 client->send_coroutine = NULL; 1870 qemu_co_mutex_unlock(&client->send_lock); 1871 1872 return ret; 1873 } 1874 1875 static inline void set_be_simple_reply(NBDSimpleReply *reply, uint64_t error, 1876 uint64_t cookie) 1877 { 1878 stl_be_p(&reply->magic, NBD_SIMPLE_REPLY_MAGIC); 1879 stl_be_p(&reply->error, error); 1880 stq_be_p(&reply->cookie, cookie); 1881 } 1882 1883 static int coroutine_fn nbd_co_send_simple_reply(NBDClient *client, 1884 NBDRequest *request, 1885 uint32_t error, 1886 void *data, 1887 size_t len, 1888 Error **errp) 1889 { 1890 NBDSimpleReply reply; 1891 int nbd_err = system_errno_to_nbd_errno(error); 1892 struct iovec iov[] = { 1893 {.iov_base = &reply, .iov_len = sizeof(reply)}, 1894 {.iov_base = data, .iov_len = len} 1895 }; 1896 1897 assert(!len || !nbd_err); 1898 assert(!client->structured_reply || request->type != NBD_CMD_READ); 1899 trace_nbd_co_send_simple_reply(request->cookie, nbd_err, 1900 nbd_err_lookup(nbd_err), len); 1901 set_be_simple_reply(&reply, nbd_err, request->cookie); 1902 1903 return nbd_co_send_iov(client, iov, 2, errp); 1904 } 1905 1906 /* 1907 * Prepare the header of a reply chunk for network transmission. 1908 * 1909 * On input, @iov is partially initialized: iov[0].iov_base must point 1910 * to an uninitialized NBDReply, while the remaining @niov elements 1911 * (if any) must be ready for transmission. This function then 1912 * populates iov[0] for transmission. 1913 */ 1914 static inline void set_be_chunk(NBDClient *client, struct iovec *iov, 1915 size_t niov, uint16_t flags, uint16_t type, 1916 NBDRequest *request) 1917 { 1918 /* TODO - handle structured vs. extended replies */ 1919 NBDStructuredReplyChunk *chunk = iov->iov_base; 1920 size_t i, length = 0; 1921 1922 for (i = 1; i < niov; i++) { 1923 length += iov[i].iov_len; 1924 } 1925 assert(length <= NBD_MAX_BUFFER_SIZE + sizeof(NBDStructuredReadData)); 1926 1927 iov[0].iov_len = sizeof(*chunk); 1928 stl_be_p(&chunk->magic, NBD_STRUCTURED_REPLY_MAGIC); 1929 stw_be_p(&chunk->flags, flags); 1930 stw_be_p(&chunk->type, type); 1931 stq_be_p(&chunk->cookie, request->cookie); 1932 stl_be_p(&chunk->length, length); 1933 } 1934 1935 static int coroutine_fn nbd_co_send_chunk_done(NBDClient *client, 1936 NBDRequest *request, 1937 Error **errp) 1938 { 1939 NBDReply hdr; 1940 struct iovec iov[] = { 1941 {.iov_base = &hdr}, 1942 }; 1943 1944 trace_nbd_co_send_chunk_done(request->cookie); 1945 set_be_chunk(client, iov, 1, NBD_REPLY_FLAG_DONE, 1946 NBD_REPLY_TYPE_NONE, request); 1947 return nbd_co_send_iov(client, iov, 1, errp); 1948 } 1949 1950 static int coroutine_fn nbd_co_send_chunk_read(NBDClient *client, 1951 NBDRequest *request, 1952 uint64_t offset, 1953 void *data, 1954 size_t size, 1955 bool final, 1956 Error **errp) 1957 { 1958 NBDReply hdr; 1959 NBDStructuredReadData chunk; 1960 struct iovec iov[] = { 1961 {.iov_base = &hdr}, 1962 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 1963 {.iov_base = data, .iov_len = size} 1964 }; 1965 1966 assert(size); 1967 trace_nbd_co_send_chunk_read(request->cookie, offset, data, size); 1968 set_be_chunk(client, iov, 3, final ? NBD_REPLY_FLAG_DONE : 0, 1969 NBD_REPLY_TYPE_OFFSET_DATA, request); 1970 stq_be_p(&chunk.offset, offset); 1971 1972 return nbd_co_send_iov(client, iov, 3, errp); 1973 } 1974 /*ebb*/ 1975 static int coroutine_fn nbd_co_send_chunk_error(NBDClient *client, 1976 NBDRequest *request, 1977 uint32_t error, 1978 const char *msg, 1979 Error **errp) 1980 { 1981 NBDReply hdr; 1982 NBDStructuredError chunk; 1983 int nbd_err = system_errno_to_nbd_errno(error); 1984 struct iovec iov[] = { 1985 {.iov_base = &hdr}, 1986 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 1987 {.iov_base = (char *)msg, .iov_len = msg ? strlen(msg) : 0}, 1988 }; 1989 1990 assert(nbd_err); 1991 trace_nbd_co_send_chunk_error(request->cookie, nbd_err, 1992 nbd_err_lookup(nbd_err), msg ? msg : ""); 1993 set_be_chunk(client, iov, 3, NBD_REPLY_FLAG_DONE, 1994 NBD_REPLY_TYPE_ERROR, request); 1995 stl_be_p(&chunk.error, nbd_err); 1996 stw_be_p(&chunk.message_length, iov[2].iov_len); 1997 1998 return nbd_co_send_iov(client, iov, 3, errp); 1999 } 2000 2001 /* Do a sparse read and send the structured reply to the client. 2002 * Returns -errno if sending fails. blk_co_block_status_above() failure is 2003 * reported to the client, at which point this function succeeds. 2004 */ 2005 static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, 2006 NBDRequest *request, 2007 uint64_t offset, 2008 uint8_t *data, 2009 size_t size, 2010 Error **errp) 2011 { 2012 int ret = 0; 2013 NBDExport *exp = client->exp; 2014 size_t progress = 0; 2015 2016 while (progress < size) { 2017 int64_t pnum; 2018 int status = blk_co_block_status_above(exp->common.blk, NULL, 2019 offset + progress, 2020 size - progress, &pnum, NULL, 2021 NULL); 2022 bool final; 2023 2024 if (status < 0) { 2025 char *msg = g_strdup_printf("unable to check for holes: %s", 2026 strerror(-status)); 2027 2028 ret = nbd_co_send_chunk_error(client, request, -status, msg, errp); 2029 g_free(msg); 2030 return ret; 2031 } 2032 assert(pnum && pnum <= size - progress); 2033 final = progress + pnum == size; 2034 if (status & BDRV_BLOCK_ZERO) { 2035 NBDReply hdr; 2036 NBDStructuredReadHole chunk; 2037 struct iovec iov[] = { 2038 {.iov_base = &hdr}, 2039 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 2040 }; 2041 2042 trace_nbd_co_send_chunk_read_hole(request->cookie, 2043 offset + progress, pnum); 2044 set_be_chunk(client, iov, 2, 2045 final ? NBD_REPLY_FLAG_DONE : 0, 2046 NBD_REPLY_TYPE_OFFSET_HOLE, request); 2047 stq_be_p(&chunk.offset, offset + progress); 2048 stl_be_p(&chunk.length, pnum); 2049 ret = nbd_co_send_iov(client, iov, 2, errp); 2050 } else { 2051 ret = blk_co_pread(exp->common.blk, offset + progress, pnum, 2052 data + progress, 0); 2053 if (ret < 0) { 2054 error_setg_errno(errp, -ret, "reading from file failed"); 2055 break; 2056 } 2057 ret = nbd_co_send_chunk_read(client, request, offset + progress, 2058 data + progress, pnum, final, errp); 2059 } 2060 2061 if (ret < 0) { 2062 break; 2063 } 2064 progress += pnum; 2065 } 2066 return ret; 2067 } 2068 2069 typedef struct NBDExtentArray { 2070 NBDExtent *extents; 2071 unsigned int nb_alloc; 2072 unsigned int count; 2073 uint64_t total_length; 2074 bool can_add; 2075 bool converted_to_be; 2076 } NBDExtentArray; 2077 2078 static NBDExtentArray *nbd_extent_array_new(unsigned int nb_alloc) 2079 { 2080 NBDExtentArray *ea = g_new0(NBDExtentArray, 1); 2081 2082 ea->nb_alloc = nb_alloc; 2083 ea->extents = g_new(NBDExtent, nb_alloc); 2084 ea->can_add = true; 2085 2086 return ea; 2087 } 2088 2089 static void nbd_extent_array_free(NBDExtentArray *ea) 2090 { 2091 g_free(ea->extents); 2092 g_free(ea); 2093 } 2094 G_DEFINE_AUTOPTR_CLEANUP_FUNC(NBDExtentArray, nbd_extent_array_free) 2095 2096 /* Further modifications of the array after conversion are abandoned */ 2097 static void nbd_extent_array_convert_to_be(NBDExtentArray *ea) 2098 { 2099 int i; 2100 2101 assert(!ea->converted_to_be); 2102 ea->can_add = false; 2103 ea->converted_to_be = true; 2104 2105 for (i = 0; i < ea->count; i++) { 2106 ea->extents[i].flags = cpu_to_be32(ea->extents[i].flags); 2107 ea->extents[i].length = cpu_to_be32(ea->extents[i].length); 2108 } 2109 } 2110 2111 /* 2112 * Add extent to NBDExtentArray. If extent can't be added (no available space), 2113 * return -1. 2114 * For safety, when returning -1 for the first time, .can_add is set to false, 2115 * and further calls to nbd_extent_array_add() will crash. 2116 * (this avoids the situation where a caller ignores failure to add one extent, 2117 * where adding another extent that would squash into the last array entry 2118 * would result in an incorrect range reported to the client) 2119 */ 2120 static int nbd_extent_array_add(NBDExtentArray *ea, 2121 uint32_t length, uint32_t flags) 2122 { 2123 assert(ea->can_add); 2124 2125 if (!length) { 2126 return 0; 2127 } 2128 2129 /* Extend previous extent if flags are the same */ 2130 if (ea->count > 0 && flags == ea->extents[ea->count - 1].flags) { 2131 uint64_t sum = (uint64_t)length + ea->extents[ea->count - 1].length; 2132 2133 if (sum <= UINT32_MAX) { 2134 ea->extents[ea->count - 1].length = sum; 2135 ea->total_length += length; 2136 return 0; 2137 } 2138 } 2139 2140 if (ea->count >= ea->nb_alloc) { 2141 ea->can_add = false; 2142 return -1; 2143 } 2144 2145 ea->total_length += length; 2146 ea->extents[ea->count] = (NBDExtent) {.length = length, .flags = flags}; 2147 ea->count++; 2148 2149 return 0; 2150 } 2151 2152 static int coroutine_fn blockstatus_to_extents(BlockBackend *blk, 2153 uint64_t offset, uint64_t bytes, 2154 NBDExtentArray *ea) 2155 { 2156 while (bytes) { 2157 uint32_t flags; 2158 int64_t num; 2159 int ret = blk_co_block_status_above(blk, NULL, offset, bytes, &num, 2160 NULL, NULL); 2161 2162 if (ret < 0) { 2163 return ret; 2164 } 2165 2166 flags = (ret & BDRV_BLOCK_DATA ? 0 : NBD_STATE_HOLE) | 2167 (ret & BDRV_BLOCK_ZERO ? NBD_STATE_ZERO : 0); 2168 2169 if (nbd_extent_array_add(ea, num, flags) < 0) { 2170 return 0; 2171 } 2172 2173 offset += num; 2174 bytes -= num; 2175 } 2176 2177 return 0; 2178 } 2179 2180 static int coroutine_fn blockalloc_to_extents(BlockBackend *blk, 2181 uint64_t offset, uint64_t bytes, 2182 NBDExtentArray *ea) 2183 { 2184 while (bytes) { 2185 int64_t num; 2186 int ret = blk_co_is_allocated_above(blk, NULL, false, offset, bytes, 2187 &num); 2188 2189 if (ret < 0) { 2190 return ret; 2191 } 2192 2193 if (nbd_extent_array_add(ea, num, ret) < 0) { 2194 return 0; 2195 } 2196 2197 offset += num; 2198 bytes -= num; 2199 } 2200 2201 return 0; 2202 } 2203 2204 /* 2205 * nbd_co_send_extents 2206 * 2207 * @ea is converted to BE by the function 2208 * @last controls whether NBD_REPLY_FLAG_DONE is sent. 2209 */ 2210 static int coroutine_fn 2211 nbd_co_send_extents(NBDClient *client, NBDRequest *request, NBDExtentArray *ea, 2212 bool last, uint32_t context_id, Error **errp) 2213 { 2214 NBDReply hdr; 2215 NBDStructuredMeta chunk; 2216 struct iovec iov[] = { 2217 {.iov_base = &hdr}, 2218 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 2219 {.iov_base = ea->extents, .iov_len = ea->count * sizeof(ea->extents[0])} 2220 }; 2221 2222 nbd_extent_array_convert_to_be(ea); 2223 2224 trace_nbd_co_send_extents(request->cookie, ea->count, context_id, 2225 ea->total_length, last); 2226 set_be_chunk(client, iov, 3, last ? NBD_REPLY_FLAG_DONE : 0, 2227 NBD_REPLY_TYPE_BLOCK_STATUS, request); 2228 stl_be_p(&chunk.context_id, context_id); 2229 2230 return nbd_co_send_iov(client, iov, 3, errp); 2231 } 2232 2233 /* Get block status from the exported device and send it to the client */ 2234 static int 2235 coroutine_fn nbd_co_send_block_status(NBDClient *client, NBDRequest *request, 2236 BlockBackend *blk, uint64_t offset, 2237 uint32_t length, bool dont_fragment, 2238 bool last, uint32_t context_id, 2239 Error **errp) 2240 { 2241 int ret; 2242 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS; 2243 g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents); 2244 2245 if (context_id == NBD_META_ID_BASE_ALLOCATION) { 2246 ret = blockstatus_to_extents(blk, offset, length, ea); 2247 } else { 2248 ret = blockalloc_to_extents(blk, offset, length, ea); 2249 } 2250 if (ret < 0) { 2251 return nbd_co_send_chunk_error(client, request, -ret, 2252 "can't get block status", errp); 2253 } 2254 2255 return nbd_co_send_extents(client, request, ea, last, context_id, errp); 2256 } 2257 2258 /* Populate @ea from a dirty bitmap. */ 2259 static void bitmap_to_extents(BdrvDirtyBitmap *bitmap, 2260 uint64_t offset, uint64_t length, 2261 NBDExtentArray *es) 2262 { 2263 int64_t start, dirty_start, dirty_count; 2264 int64_t end = offset + length; 2265 bool full = false; 2266 2267 bdrv_dirty_bitmap_lock(bitmap); 2268 2269 for (start = offset; 2270 bdrv_dirty_bitmap_next_dirty_area(bitmap, start, end, INT32_MAX, 2271 &dirty_start, &dirty_count); 2272 start = dirty_start + dirty_count) 2273 { 2274 if ((nbd_extent_array_add(es, dirty_start - start, 0) < 0) || 2275 (nbd_extent_array_add(es, dirty_count, NBD_STATE_DIRTY) < 0)) 2276 { 2277 full = true; 2278 break; 2279 } 2280 } 2281 2282 if (!full) { 2283 /* last non dirty extent, nothing to do if array is now full */ 2284 (void) nbd_extent_array_add(es, end - start, 0); 2285 } 2286 2287 bdrv_dirty_bitmap_unlock(bitmap); 2288 } 2289 2290 static int coroutine_fn nbd_co_send_bitmap(NBDClient *client, 2291 NBDRequest *request, 2292 BdrvDirtyBitmap *bitmap, 2293 uint64_t offset, 2294 uint32_t length, bool dont_fragment, 2295 bool last, uint32_t context_id, 2296 Error **errp) 2297 { 2298 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS; 2299 g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents); 2300 2301 bitmap_to_extents(bitmap, offset, length, ea); 2302 2303 return nbd_co_send_extents(client, request, ea, last, context_id, errp); 2304 } 2305 2306 /* nbd_co_receive_request 2307 * Collect a client request. Return 0 if request looks valid, -EIO to drop 2308 * connection right away, -EAGAIN to indicate we were interrupted and the 2309 * channel should be quiesced, and any other negative value to report an error 2310 * to the client (although the caller may still need to disconnect after 2311 * reporting the error). 2312 */ 2313 static int coroutine_fn nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, 2314 Error **errp) 2315 { 2316 NBDClient *client = req->client; 2317 int valid_flags; 2318 int ret; 2319 2320 g_assert(qemu_in_coroutine()); 2321 assert(client->recv_coroutine == qemu_coroutine_self()); 2322 ret = nbd_receive_request(client, request, errp); 2323 if (ret < 0) { 2324 return ret; 2325 } 2326 2327 trace_nbd_co_receive_request_decode_type(request->cookie, request->type, 2328 nbd_cmd_lookup(request->type)); 2329 2330 if (request->type != NBD_CMD_WRITE) { 2331 /* No payload, we are ready to read the next request. */ 2332 req->complete = true; 2333 } 2334 2335 if (request->type == NBD_CMD_DISC) { 2336 /* Special case: we're going to disconnect without a reply, 2337 * whether or not flags, from, or len are bogus */ 2338 return -EIO; 2339 } 2340 2341 if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE || 2342 request->type == NBD_CMD_CACHE) 2343 { 2344 if (request->len > NBD_MAX_BUFFER_SIZE) { 2345 error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)", 2346 request->len, NBD_MAX_BUFFER_SIZE); 2347 return -EINVAL; 2348 } 2349 2350 if (request->type != NBD_CMD_CACHE) { 2351 req->data = blk_try_blockalign(client->exp->common.blk, 2352 request->len); 2353 if (req->data == NULL) { 2354 error_setg(errp, "No memory"); 2355 return -ENOMEM; 2356 } 2357 } 2358 } 2359 2360 if (request->type == NBD_CMD_WRITE) { 2361 if (nbd_read(client->ioc, req->data, request->len, "CMD_WRITE data", 2362 errp) < 0) 2363 { 2364 return -EIO; 2365 } 2366 req->complete = true; 2367 2368 trace_nbd_co_receive_request_payload_received(request->cookie, 2369 request->len); 2370 } 2371 2372 /* Sanity checks. */ 2373 if (client->exp->nbdflags & NBD_FLAG_READ_ONLY && 2374 (request->type == NBD_CMD_WRITE || 2375 request->type == NBD_CMD_WRITE_ZEROES || 2376 request->type == NBD_CMD_TRIM)) { 2377 error_setg(errp, "Export is read-only"); 2378 return -EROFS; 2379 } 2380 if (request->from > client->exp->size || 2381 request->len > client->exp->size - request->from) { 2382 error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32 2383 ", Size: %" PRIu64, request->from, request->len, 2384 client->exp->size); 2385 return (request->type == NBD_CMD_WRITE || 2386 request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL; 2387 } 2388 if (client->check_align && !QEMU_IS_ALIGNED(request->from | request->len, 2389 client->check_align)) { 2390 /* 2391 * The block layer gracefully handles unaligned requests, but 2392 * it's still worth tracing client non-compliance 2393 */ 2394 trace_nbd_co_receive_align_compliance(nbd_cmd_lookup(request->type), 2395 request->from, 2396 request->len, 2397 client->check_align); 2398 } 2399 valid_flags = NBD_CMD_FLAG_FUA; 2400 if (request->type == NBD_CMD_READ && client->structured_reply) { 2401 valid_flags |= NBD_CMD_FLAG_DF; 2402 } else if (request->type == NBD_CMD_WRITE_ZEROES) { 2403 valid_flags |= NBD_CMD_FLAG_NO_HOLE | NBD_CMD_FLAG_FAST_ZERO; 2404 } else if (request->type == NBD_CMD_BLOCK_STATUS) { 2405 valid_flags |= NBD_CMD_FLAG_REQ_ONE; 2406 } 2407 if (request->flags & ~valid_flags) { 2408 error_setg(errp, "unsupported flags for command %s (got 0x%x)", 2409 nbd_cmd_lookup(request->type), request->flags); 2410 return -EINVAL; 2411 } 2412 2413 return 0; 2414 } 2415 2416 /* Send simple reply without a payload, or a structured error 2417 * @error_msg is ignored if @ret >= 0 2418 * Returns 0 if connection is still live, -errno on failure to talk to client 2419 */ 2420 static coroutine_fn int nbd_send_generic_reply(NBDClient *client, 2421 NBDRequest *request, 2422 int ret, 2423 const char *error_msg, 2424 Error **errp) 2425 { 2426 if (client->structured_reply && ret < 0) { 2427 return nbd_co_send_chunk_error(client, request, -ret, error_msg, errp); 2428 } else { 2429 return nbd_co_send_simple_reply(client, request, ret < 0 ? -ret : 0, 2430 NULL, 0, errp); 2431 } 2432 } 2433 2434 /* Handle NBD_CMD_READ request. 2435 * Return -errno if sending fails. Other errors are reported directly to the 2436 * client as an error reply. */ 2437 static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, 2438 uint8_t *data, Error **errp) 2439 { 2440 int ret; 2441 NBDExport *exp = client->exp; 2442 2443 assert(request->type == NBD_CMD_READ); 2444 2445 /* XXX: NBD Protocol only documents use of FUA with WRITE */ 2446 if (request->flags & NBD_CMD_FLAG_FUA) { 2447 ret = blk_co_flush(exp->common.blk); 2448 if (ret < 0) { 2449 return nbd_send_generic_reply(client, request, ret, 2450 "flush failed", errp); 2451 } 2452 } 2453 2454 if (client->structured_reply && !(request->flags & NBD_CMD_FLAG_DF) && 2455 request->len) 2456 { 2457 return nbd_co_send_sparse_read(client, request, request->from, 2458 data, request->len, errp); 2459 } 2460 2461 ret = blk_co_pread(exp->common.blk, request->from, request->len, data, 0); 2462 if (ret < 0) { 2463 return nbd_send_generic_reply(client, request, ret, 2464 "reading from file failed", errp); 2465 } 2466 2467 if (client->structured_reply) { 2468 if (request->len) { 2469 return nbd_co_send_chunk_read(client, request, request->from, data, 2470 request->len, true, errp); 2471 } else { 2472 return nbd_co_send_chunk_done(client, request, errp); 2473 } 2474 } else { 2475 return nbd_co_send_simple_reply(client, request, 0, 2476 data, request->len, errp); 2477 } 2478 } 2479 2480 /* 2481 * nbd_do_cmd_cache 2482 * 2483 * Handle NBD_CMD_CACHE request. 2484 * Return -errno if sending fails. Other errors are reported directly to the 2485 * client as an error reply. 2486 */ 2487 static coroutine_fn int nbd_do_cmd_cache(NBDClient *client, NBDRequest *request, 2488 Error **errp) 2489 { 2490 int ret; 2491 NBDExport *exp = client->exp; 2492 2493 assert(request->type == NBD_CMD_CACHE); 2494 2495 ret = blk_co_preadv(exp->common.blk, request->from, request->len, 2496 NULL, BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH); 2497 2498 return nbd_send_generic_reply(client, request, ret, 2499 "caching data failed", errp); 2500 } 2501 2502 /* Handle NBD request. 2503 * Return -errno if sending fails. Other errors are reported directly to the 2504 * client as an error reply. */ 2505 static coroutine_fn int nbd_handle_request(NBDClient *client, 2506 NBDRequest *request, 2507 uint8_t *data, Error **errp) 2508 { 2509 int ret; 2510 int flags; 2511 NBDExport *exp = client->exp; 2512 char *msg; 2513 size_t i; 2514 2515 switch (request->type) { 2516 case NBD_CMD_CACHE: 2517 return nbd_do_cmd_cache(client, request, errp); 2518 2519 case NBD_CMD_READ: 2520 return nbd_do_cmd_read(client, request, data, errp); 2521 2522 case NBD_CMD_WRITE: 2523 flags = 0; 2524 if (request->flags & NBD_CMD_FLAG_FUA) { 2525 flags |= BDRV_REQ_FUA; 2526 } 2527 ret = blk_co_pwrite(exp->common.blk, request->from, request->len, data, 2528 flags); 2529 return nbd_send_generic_reply(client, request, ret, 2530 "writing to file failed", errp); 2531 2532 case NBD_CMD_WRITE_ZEROES: 2533 flags = 0; 2534 if (request->flags & NBD_CMD_FLAG_FUA) { 2535 flags |= BDRV_REQ_FUA; 2536 } 2537 if (!(request->flags & NBD_CMD_FLAG_NO_HOLE)) { 2538 flags |= BDRV_REQ_MAY_UNMAP; 2539 } 2540 if (request->flags & NBD_CMD_FLAG_FAST_ZERO) { 2541 flags |= BDRV_REQ_NO_FALLBACK; 2542 } 2543 ret = blk_co_pwrite_zeroes(exp->common.blk, request->from, request->len, 2544 flags); 2545 return nbd_send_generic_reply(client, request, ret, 2546 "writing to file failed", errp); 2547 2548 case NBD_CMD_DISC: 2549 /* unreachable, thanks to special case in nbd_co_receive_request() */ 2550 abort(); 2551 2552 case NBD_CMD_FLUSH: 2553 ret = blk_co_flush(exp->common.blk); 2554 return nbd_send_generic_reply(client, request, ret, 2555 "flush failed", errp); 2556 2557 case NBD_CMD_TRIM: 2558 ret = blk_co_pdiscard(exp->common.blk, request->from, request->len); 2559 if (ret >= 0 && request->flags & NBD_CMD_FLAG_FUA) { 2560 ret = blk_co_flush(exp->common.blk); 2561 } 2562 return nbd_send_generic_reply(client, request, ret, 2563 "discard failed", errp); 2564 2565 case NBD_CMD_BLOCK_STATUS: 2566 if (!request->len) { 2567 return nbd_send_generic_reply(client, request, -EINVAL, 2568 "need non-zero length", errp); 2569 } 2570 if (client->export_meta.count) { 2571 bool dont_fragment = request->flags & NBD_CMD_FLAG_REQ_ONE; 2572 int contexts_remaining = client->export_meta.count; 2573 2574 if (client->export_meta.base_allocation) { 2575 ret = nbd_co_send_block_status(client, request, 2576 exp->common.blk, 2577 request->from, 2578 request->len, dont_fragment, 2579 !--contexts_remaining, 2580 NBD_META_ID_BASE_ALLOCATION, 2581 errp); 2582 if (ret < 0) { 2583 return ret; 2584 } 2585 } 2586 2587 if (client->export_meta.allocation_depth) { 2588 ret = nbd_co_send_block_status(client, request, 2589 exp->common.blk, 2590 request->from, request->len, 2591 dont_fragment, 2592 !--contexts_remaining, 2593 NBD_META_ID_ALLOCATION_DEPTH, 2594 errp); 2595 if (ret < 0) { 2596 return ret; 2597 } 2598 } 2599 2600 for (i = 0; i < client->exp->nr_export_bitmaps; i++) { 2601 if (!client->export_meta.bitmaps[i]) { 2602 continue; 2603 } 2604 ret = nbd_co_send_bitmap(client, request, 2605 client->exp->export_bitmaps[i], 2606 request->from, request->len, 2607 dont_fragment, !--contexts_remaining, 2608 NBD_META_ID_DIRTY_BITMAP + i, errp); 2609 if (ret < 0) { 2610 return ret; 2611 } 2612 } 2613 2614 assert(!contexts_remaining); 2615 2616 return 0; 2617 } else { 2618 return nbd_send_generic_reply(client, request, -EINVAL, 2619 "CMD_BLOCK_STATUS not negotiated", 2620 errp); 2621 } 2622 2623 default: 2624 msg = g_strdup_printf("invalid request type (%" PRIu32 ") received", 2625 request->type); 2626 ret = nbd_send_generic_reply(client, request, -EINVAL, msg, 2627 errp); 2628 g_free(msg); 2629 return ret; 2630 } 2631 } 2632 2633 /* Owns a reference to the NBDClient passed as opaque. */ 2634 static coroutine_fn void nbd_trip(void *opaque) 2635 { 2636 NBDClient *client = opaque; 2637 NBDRequestData *req; 2638 NBDRequest request = { 0 }; /* GCC thinks it can be used uninitialized */ 2639 int ret; 2640 Error *local_err = NULL; 2641 2642 trace_nbd_trip(); 2643 if (client->closing) { 2644 nbd_client_put(client); 2645 return; 2646 } 2647 2648 if (client->quiescing) { 2649 /* 2650 * We're switching between AIO contexts. Don't attempt to receive a new 2651 * request and kick the main context which may be waiting for us. 2652 */ 2653 nbd_client_put(client); 2654 client->recv_coroutine = NULL; 2655 aio_wait_kick(); 2656 return; 2657 } 2658 2659 req = nbd_request_get(client); 2660 ret = nbd_co_receive_request(req, &request, &local_err); 2661 client->recv_coroutine = NULL; 2662 2663 if (client->closing) { 2664 /* 2665 * The client may be closed when we are blocked in 2666 * nbd_co_receive_request() 2667 */ 2668 goto done; 2669 } 2670 2671 if (ret == -EAGAIN) { 2672 assert(client->quiescing); 2673 goto done; 2674 } 2675 2676 nbd_client_receive_next_request(client); 2677 if (ret == -EIO) { 2678 goto disconnect; 2679 } 2680 2681 qio_channel_set_cork(client->ioc, true); 2682 2683 if (ret < 0) { 2684 /* It wasn't -EIO, so, according to nbd_co_receive_request() 2685 * semantics, we should return the error to the client. */ 2686 Error *export_err = local_err; 2687 2688 local_err = NULL; 2689 ret = nbd_send_generic_reply(client, &request, -EINVAL, 2690 error_get_pretty(export_err), &local_err); 2691 error_free(export_err); 2692 } else { 2693 ret = nbd_handle_request(client, &request, req->data, &local_err); 2694 } 2695 if (ret < 0) { 2696 error_prepend(&local_err, "Failed to send reply: "); 2697 goto disconnect; 2698 } 2699 2700 /* We must disconnect after NBD_CMD_WRITE if we did not 2701 * read the payload. 2702 */ 2703 if (!req->complete) { 2704 error_setg(&local_err, "Request handling failed in intermediate state"); 2705 goto disconnect; 2706 } 2707 2708 qio_channel_set_cork(client->ioc, false); 2709 done: 2710 nbd_request_put(req); 2711 nbd_client_put(client); 2712 return; 2713 2714 disconnect: 2715 if (local_err) { 2716 error_reportf_err(local_err, "Disconnect client, due to: "); 2717 } 2718 nbd_request_put(req); 2719 client_close(client, true); 2720 nbd_client_put(client); 2721 } 2722 2723 static void nbd_client_receive_next_request(NBDClient *client) 2724 { 2725 if (!client->recv_coroutine && client->nb_requests < MAX_NBD_REQUESTS && 2726 !client->quiescing) { 2727 nbd_client_get(client); 2728 client->recv_coroutine = qemu_coroutine_create(nbd_trip, client); 2729 aio_co_schedule(client->exp->common.ctx, client->recv_coroutine); 2730 } 2731 } 2732 2733 static coroutine_fn void nbd_co_client_start(void *opaque) 2734 { 2735 NBDClient *client = opaque; 2736 Error *local_err = NULL; 2737 2738 qemu_co_mutex_init(&client->send_lock); 2739 2740 if (nbd_negotiate(client, &local_err)) { 2741 if (local_err) { 2742 error_report_err(local_err); 2743 } 2744 client_close(client, false); 2745 return; 2746 } 2747 2748 nbd_client_receive_next_request(client); 2749 } 2750 2751 /* 2752 * Create a new client listener using the given channel @sioc. 2753 * Begin servicing it in a coroutine. When the connection closes, call 2754 * @close_fn with an indication of whether the client completed negotiation. 2755 */ 2756 void nbd_client_new(QIOChannelSocket *sioc, 2757 QCryptoTLSCreds *tlscreds, 2758 const char *tlsauthz, 2759 void (*close_fn)(NBDClient *, bool)) 2760 { 2761 NBDClient *client; 2762 Coroutine *co; 2763 2764 client = g_new0(NBDClient, 1); 2765 client->refcount = 1; 2766 client->tlscreds = tlscreds; 2767 if (tlscreds) { 2768 object_ref(OBJECT(client->tlscreds)); 2769 } 2770 client->tlsauthz = g_strdup(tlsauthz); 2771 client->sioc = sioc; 2772 qio_channel_set_delay(QIO_CHANNEL(sioc), false); 2773 object_ref(OBJECT(client->sioc)); 2774 client->ioc = QIO_CHANNEL(sioc); 2775 object_ref(OBJECT(client->ioc)); 2776 client->close_fn = close_fn; 2777 2778 co = qemu_coroutine_create(nbd_co_client_start, client); 2779 qemu_coroutine_enter(co); 2780 } 2781