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 1337 trace_nbd_negotiate_begin(); 1338 memcpy(buf, "NBDMAGIC", 8); 1339 1340 stq_be_p(buf + 8, NBD_OPTS_MAGIC); 1341 stw_be_p(buf + 16, NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES); 1342 1343 if (nbd_write(client->ioc, buf, 18, errp) < 0) { 1344 error_prepend(errp, "write failed: "); 1345 return -EINVAL; 1346 } 1347 ret = nbd_negotiate_options(client, errp); 1348 if (ret != 0) { 1349 if (ret < 0) { 1350 error_prepend(errp, "option negotiation failed: "); 1351 } 1352 return ret; 1353 } 1354 1355 /* Attach the channel to the same AioContext as the export */ 1356 if (client->exp && client->exp->common.ctx) { 1357 qio_channel_attach_aio_context(client->ioc, client->exp->common.ctx); 1358 } 1359 1360 assert(!client->optlen); 1361 trace_nbd_negotiate_success(); 1362 1363 return 0; 1364 } 1365 1366 /* nbd_read_eof 1367 * Tries to read @size bytes from @ioc. This is a local implementation of 1368 * qio_channel_readv_all_eof. We have it here because we need it to be 1369 * interruptible and to know when the coroutine is yielding. 1370 * Returns 1 on success 1371 * 0 on eof, when no data was read (errp is not set) 1372 * negative errno on failure (errp is set) 1373 */ 1374 static inline int coroutine_fn 1375 nbd_read_eof(NBDClient *client, void *buffer, size_t size, Error **errp) 1376 { 1377 bool partial = false; 1378 1379 assert(size); 1380 while (size > 0) { 1381 struct iovec iov = { .iov_base = buffer, .iov_len = size }; 1382 ssize_t len; 1383 1384 len = qio_channel_readv(client->ioc, &iov, 1, errp); 1385 if (len == QIO_CHANNEL_ERR_BLOCK) { 1386 client->read_yielding = true; 1387 qio_channel_yield(client->ioc, G_IO_IN); 1388 client->read_yielding = false; 1389 if (client->quiescing) { 1390 return -EAGAIN; 1391 } 1392 continue; 1393 } else if (len < 0) { 1394 return -EIO; 1395 } else if (len == 0) { 1396 if (partial) { 1397 error_setg(errp, 1398 "Unexpected end-of-file before all bytes were read"); 1399 return -EIO; 1400 } else { 1401 return 0; 1402 } 1403 } 1404 1405 partial = true; 1406 size -= len; 1407 buffer = (uint8_t *) buffer + len; 1408 } 1409 return 1; 1410 } 1411 1412 static int coroutine_fn nbd_receive_request(NBDClient *client, NBDRequest *request, 1413 Error **errp) 1414 { 1415 uint8_t buf[NBD_REQUEST_SIZE]; 1416 uint32_t magic; 1417 int ret; 1418 1419 ret = nbd_read_eof(client, buf, sizeof(buf), errp); 1420 if (ret < 0) { 1421 return ret; 1422 } 1423 if (ret == 0) { 1424 return -EIO; 1425 } 1426 1427 /* Request 1428 [ 0 .. 3] magic (NBD_REQUEST_MAGIC) 1429 [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...) 1430 [ 6 .. 7] type (NBD_CMD_READ, ...) 1431 [ 8 .. 15] cookie 1432 [16 .. 23] from 1433 [24 .. 27] len 1434 */ 1435 1436 magic = ldl_be_p(buf); 1437 request->flags = lduw_be_p(buf + 4); 1438 request->type = lduw_be_p(buf + 6); 1439 request->cookie = ldq_be_p(buf + 8); 1440 request->from = ldq_be_p(buf + 16); 1441 request->len = ldl_be_p(buf + 24); 1442 1443 trace_nbd_receive_request(magic, request->flags, request->type, 1444 request->from, request->len); 1445 1446 if (magic != NBD_REQUEST_MAGIC) { 1447 error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", magic); 1448 return -EINVAL; 1449 } 1450 return 0; 1451 } 1452 1453 #define MAX_NBD_REQUESTS 16 1454 1455 void nbd_client_get(NBDClient *client) 1456 { 1457 client->refcount++; 1458 } 1459 1460 void nbd_client_put(NBDClient *client) 1461 { 1462 if (--client->refcount == 0) { 1463 /* The last reference should be dropped by client->close, 1464 * which is called by client_close. 1465 */ 1466 assert(client->closing); 1467 1468 qio_channel_detach_aio_context(client->ioc); 1469 object_unref(OBJECT(client->sioc)); 1470 object_unref(OBJECT(client->ioc)); 1471 if (client->tlscreds) { 1472 object_unref(OBJECT(client->tlscreds)); 1473 } 1474 g_free(client->tlsauthz); 1475 if (client->exp) { 1476 QTAILQ_REMOVE(&client->exp->clients, client, next); 1477 blk_exp_unref(&client->exp->common); 1478 } 1479 g_free(client->export_meta.bitmaps); 1480 g_free(client); 1481 } 1482 } 1483 1484 static void client_close(NBDClient *client, bool negotiated) 1485 { 1486 if (client->closing) { 1487 return; 1488 } 1489 1490 client->closing = true; 1491 1492 /* Force requests to finish. They will drop their own references, 1493 * then we'll close the socket and free the NBDClient. 1494 */ 1495 qio_channel_shutdown(client->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, 1496 NULL); 1497 1498 /* Also tell the client, so that they release their reference. */ 1499 if (client->close_fn) { 1500 client->close_fn(client, negotiated); 1501 } 1502 } 1503 1504 static NBDRequestData *nbd_request_get(NBDClient *client) 1505 { 1506 NBDRequestData *req; 1507 1508 assert(client->nb_requests <= MAX_NBD_REQUESTS - 1); 1509 client->nb_requests++; 1510 1511 req = g_new0(NBDRequestData, 1); 1512 nbd_client_get(client); 1513 req->client = client; 1514 return req; 1515 } 1516 1517 static void nbd_request_put(NBDRequestData *req) 1518 { 1519 NBDClient *client = req->client; 1520 1521 if (req->data) { 1522 qemu_vfree(req->data); 1523 } 1524 g_free(req); 1525 1526 client->nb_requests--; 1527 1528 if (client->quiescing && client->nb_requests == 0) { 1529 aio_wait_kick(); 1530 } 1531 1532 nbd_client_receive_next_request(client); 1533 1534 nbd_client_put(client); 1535 } 1536 1537 static void blk_aio_attached(AioContext *ctx, void *opaque) 1538 { 1539 NBDExport *exp = opaque; 1540 NBDClient *client; 1541 1542 trace_nbd_blk_aio_attached(exp->name, ctx); 1543 1544 exp->common.ctx = ctx; 1545 1546 QTAILQ_FOREACH(client, &exp->clients, next) { 1547 qio_channel_attach_aio_context(client->ioc, ctx); 1548 1549 assert(client->nb_requests == 0); 1550 assert(client->recv_coroutine == NULL); 1551 assert(client->send_coroutine == NULL); 1552 } 1553 } 1554 1555 static void blk_aio_detach(void *opaque) 1556 { 1557 NBDExport *exp = opaque; 1558 NBDClient *client; 1559 1560 trace_nbd_blk_aio_detach(exp->name, exp->common.ctx); 1561 1562 QTAILQ_FOREACH(client, &exp->clients, next) { 1563 qio_channel_detach_aio_context(client->ioc); 1564 } 1565 1566 exp->common.ctx = NULL; 1567 } 1568 1569 static void nbd_drained_begin(void *opaque) 1570 { 1571 NBDExport *exp = opaque; 1572 NBDClient *client; 1573 1574 QTAILQ_FOREACH(client, &exp->clients, next) { 1575 client->quiescing = true; 1576 } 1577 } 1578 1579 static void nbd_drained_end(void *opaque) 1580 { 1581 NBDExport *exp = opaque; 1582 NBDClient *client; 1583 1584 QTAILQ_FOREACH(client, &exp->clients, next) { 1585 client->quiescing = false; 1586 nbd_client_receive_next_request(client); 1587 } 1588 } 1589 1590 static bool nbd_drained_poll(void *opaque) 1591 { 1592 NBDExport *exp = opaque; 1593 NBDClient *client; 1594 1595 QTAILQ_FOREACH(client, &exp->clients, next) { 1596 if (client->nb_requests != 0) { 1597 /* 1598 * If there's a coroutine waiting for a request on nbd_read_eof() 1599 * enter it here so we don't depend on the client to wake it up. 1600 */ 1601 if (client->recv_coroutine != NULL && client->read_yielding) { 1602 qio_channel_wake_read(client->ioc); 1603 } 1604 1605 return true; 1606 } 1607 } 1608 1609 return false; 1610 } 1611 1612 static void nbd_eject_notifier(Notifier *n, void *data) 1613 { 1614 NBDExport *exp = container_of(n, NBDExport, eject_notifier); 1615 1616 blk_exp_request_shutdown(&exp->common); 1617 } 1618 1619 void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk) 1620 { 1621 NBDExport *nbd_exp = container_of(exp, NBDExport, common); 1622 assert(exp->drv == &blk_exp_nbd); 1623 assert(nbd_exp->eject_notifier_blk == NULL); 1624 1625 blk_ref(blk); 1626 nbd_exp->eject_notifier_blk = blk; 1627 nbd_exp->eject_notifier.notify = nbd_eject_notifier; 1628 blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier); 1629 } 1630 1631 static const BlockDevOps nbd_block_ops = { 1632 .drained_begin = nbd_drained_begin, 1633 .drained_end = nbd_drained_end, 1634 .drained_poll = nbd_drained_poll, 1635 }; 1636 1637 static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args, 1638 Error **errp) 1639 { 1640 NBDExport *exp = container_of(blk_exp, NBDExport, common); 1641 BlockExportOptionsNbd *arg = &exp_args->u.nbd; 1642 const char *name = arg->name ?: exp_args->node_name; 1643 BlockBackend *blk = blk_exp->blk; 1644 int64_t size; 1645 uint64_t perm, shared_perm; 1646 bool readonly = !exp_args->writable; 1647 BlockDirtyBitmapOrStrList *bitmaps; 1648 size_t i; 1649 int ret; 1650 1651 assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD); 1652 1653 if (!nbd_server_is_running()) { 1654 error_setg(errp, "NBD server not running"); 1655 return -EINVAL; 1656 } 1657 1658 if (strlen(name) > NBD_MAX_STRING_SIZE) { 1659 error_setg(errp, "export name '%s' too long", 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(name)) { 1669 error_setg(errp, "NBD server already has export named '%s'", 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(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 1694 if (nbd_server_max_connections() != 1) { 1695 exp->nbdflags |= NBD_FLAG_CAN_MULTI_CONN; 1696 } 1697 if (readonly) { 1698 exp->nbdflags |= NBD_FLAG_READ_ONLY; 1699 } else { 1700 exp->nbdflags |= (NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_WRITE_ZEROES | 1701 NBD_FLAG_SEND_FAST_ZERO); 1702 } 1703 exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE); 1704 1705 for (bitmaps = arg->bitmaps; bitmaps; bitmaps = bitmaps->next) { 1706 exp->nr_export_bitmaps++; 1707 } 1708 exp->export_bitmaps = g_new0(BdrvDirtyBitmap *, exp->nr_export_bitmaps); 1709 for (i = 0, bitmaps = arg->bitmaps; bitmaps; 1710 i++, bitmaps = bitmaps->next) 1711 { 1712 const char *bitmap; 1713 BlockDriverState *bs = blk_bs(blk); 1714 BdrvDirtyBitmap *bm = NULL; 1715 1716 switch (bitmaps->value->type) { 1717 case QTYPE_QSTRING: 1718 bitmap = bitmaps->value->u.local; 1719 while (bs) { 1720 bm = bdrv_find_dirty_bitmap(bs, bitmap); 1721 if (bm != NULL) { 1722 break; 1723 } 1724 1725 bs = bdrv_filter_or_cow_bs(bs); 1726 } 1727 1728 if (bm == NULL) { 1729 ret = -ENOENT; 1730 error_setg(errp, "Bitmap '%s' is not found", 1731 bitmaps->value->u.local); 1732 goto fail; 1733 } 1734 1735 if (readonly && bdrv_is_writable(bs) && 1736 bdrv_dirty_bitmap_enabled(bm)) { 1737 ret = -EINVAL; 1738 error_setg(errp, "Enabled bitmap '%s' incompatible with " 1739 "readonly export", bitmap); 1740 goto fail; 1741 } 1742 break; 1743 case QTYPE_QDICT: 1744 bitmap = bitmaps->value->u.external.name; 1745 bm = block_dirty_bitmap_lookup(bitmaps->value->u.external.node, 1746 bitmap, NULL, errp); 1747 if (!bm) { 1748 ret = -ENOENT; 1749 goto fail; 1750 } 1751 break; 1752 default: 1753 abort(); 1754 } 1755 1756 assert(bm); 1757 1758 if (bdrv_dirty_bitmap_check(bm, BDRV_BITMAP_ALLOW_RO, errp)) { 1759 ret = -EINVAL; 1760 goto fail; 1761 } 1762 1763 exp->export_bitmaps[i] = bm; 1764 assert(strlen(bitmap) <= BDRV_BITMAP_MAX_NAME_SIZE); 1765 } 1766 1767 /* Mark bitmaps busy in a separate loop, to simplify roll-back concerns. */ 1768 for (i = 0; i < exp->nr_export_bitmaps; i++) { 1769 bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], true); 1770 } 1771 1772 exp->allocation_depth = arg->allocation_depth; 1773 1774 /* 1775 * We need to inhibit request queuing in the block layer to ensure we can 1776 * be properly quiesced when entering a drained section, as our coroutines 1777 * servicing pending requests might enter blk_pread(). 1778 */ 1779 blk_set_disable_request_queuing(blk, true); 1780 1781 blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp); 1782 1783 blk_set_dev_ops(blk, &nbd_block_ops, exp); 1784 1785 QTAILQ_INSERT_TAIL(&exports, exp, next); 1786 1787 return 0; 1788 1789 fail: 1790 g_free(exp->export_bitmaps); 1791 g_free(exp->name); 1792 g_free(exp->description); 1793 return ret; 1794 } 1795 1796 NBDExport *nbd_export_find(const char *name) 1797 { 1798 NBDExport *exp; 1799 QTAILQ_FOREACH(exp, &exports, next) { 1800 if (strcmp(name, exp->name) == 0) { 1801 return exp; 1802 } 1803 } 1804 1805 return NULL; 1806 } 1807 1808 AioContext * 1809 nbd_export_aio_context(NBDExport *exp) 1810 { 1811 return exp->common.ctx; 1812 } 1813 1814 static void nbd_export_request_shutdown(BlockExport *blk_exp) 1815 { 1816 NBDExport *exp = container_of(blk_exp, NBDExport, common); 1817 NBDClient *client, *next; 1818 1819 blk_exp_ref(&exp->common); 1820 /* 1821 * TODO: Should we expand QMP NbdServerRemoveNode enum to allow a 1822 * close mode that stops advertising the export to new clients but 1823 * still permits existing clients to run to completion? Because of 1824 * that possibility, nbd_export_close() can be called more than 1825 * once on an export. 1826 */ 1827 QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) { 1828 client_close(client, true); 1829 } 1830 if (exp->name) { 1831 g_free(exp->name); 1832 exp->name = NULL; 1833 QTAILQ_REMOVE(&exports, exp, next); 1834 } 1835 blk_exp_unref(&exp->common); 1836 } 1837 1838 static void nbd_export_delete(BlockExport *blk_exp) 1839 { 1840 size_t i; 1841 NBDExport *exp = container_of(blk_exp, NBDExport, common); 1842 1843 assert(exp->name == NULL); 1844 assert(QTAILQ_EMPTY(&exp->clients)); 1845 1846 g_free(exp->description); 1847 exp->description = NULL; 1848 1849 if (exp->eject_notifier_blk) { 1850 notifier_remove(&exp->eject_notifier); 1851 blk_unref(exp->eject_notifier_blk); 1852 } 1853 blk_remove_aio_context_notifier(exp->common.blk, blk_aio_attached, 1854 blk_aio_detach, exp); 1855 blk_set_disable_request_queuing(exp->common.blk, false); 1856 1857 for (i = 0; i < exp->nr_export_bitmaps; i++) { 1858 bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], false); 1859 } 1860 } 1861 1862 const BlockExportDriver blk_exp_nbd = { 1863 .type = BLOCK_EXPORT_TYPE_NBD, 1864 .instance_size = sizeof(NBDExport), 1865 .create = nbd_export_create, 1866 .delete = nbd_export_delete, 1867 .request_shutdown = nbd_export_request_shutdown, 1868 }; 1869 1870 static int coroutine_fn nbd_co_send_iov(NBDClient *client, struct iovec *iov, 1871 unsigned niov, Error **errp) 1872 { 1873 int ret; 1874 1875 g_assert(qemu_in_coroutine()); 1876 qemu_co_mutex_lock(&client->send_lock); 1877 client->send_coroutine = qemu_coroutine_self(); 1878 1879 ret = qio_channel_writev_all(client->ioc, iov, niov, errp) < 0 ? -EIO : 0; 1880 1881 client->send_coroutine = NULL; 1882 qemu_co_mutex_unlock(&client->send_lock); 1883 1884 return ret; 1885 } 1886 1887 static inline void set_be_simple_reply(NBDSimpleReply *reply, uint64_t error, 1888 uint64_t cookie) 1889 { 1890 stl_be_p(&reply->magic, NBD_SIMPLE_REPLY_MAGIC); 1891 stl_be_p(&reply->error, error); 1892 stq_be_p(&reply->cookie, cookie); 1893 } 1894 1895 static int coroutine_fn nbd_co_send_simple_reply(NBDClient *client, 1896 NBDRequest *request, 1897 uint32_t error, 1898 void *data, 1899 size_t len, 1900 Error **errp) 1901 { 1902 NBDSimpleReply reply; 1903 int nbd_err = system_errno_to_nbd_errno(error); 1904 struct iovec iov[] = { 1905 {.iov_base = &reply, .iov_len = sizeof(reply)}, 1906 {.iov_base = data, .iov_len = len} 1907 }; 1908 1909 assert(!len || !nbd_err); 1910 assert(!client->structured_reply || request->type != NBD_CMD_READ); 1911 trace_nbd_co_send_simple_reply(request->cookie, nbd_err, 1912 nbd_err_lookup(nbd_err), len); 1913 set_be_simple_reply(&reply, nbd_err, request->cookie); 1914 1915 return nbd_co_send_iov(client, iov, 2, errp); 1916 } 1917 1918 /* 1919 * Prepare the header of a reply chunk for network transmission. 1920 * 1921 * On input, @iov is partially initialized: iov[0].iov_base must point 1922 * to an uninitialized NBDReply, while the remaining @niov elements 1923 * (if any) must be ready for transmission. This function then 1924 * populates iov[0] for transmission. 1925 */ 1926 static inline void set_be_chunk(NBDClient *client, struct iovec *iov, 1927 size_t niov, uint16_t flags, uint16_t type, 1928 NBDRequest *request) 1929 { 1930 /* TODO - handle structured vs. extended replies */ 1931 NBDStructuredReplyChunk *chunk = iov->iov_base; 1932 size_t i, length = 0; 1933 1934 for (i = 1; i < niov; i++) { 1935 length += iov[i].iov_len; 1936 } 1937 assert(length <= NBD_MAX_BUFFER_SIZE + sizeof(NBDStructuredReadData)); 1938 1939 iov[0].iov_len = sizeof(*chunk); 1940 stl_be_p(&chunk->magic, NBD_STRUCTURED_REPLY_MAGIC); 1941 stw_be_p(&chunk->flags, flags); 1942 stw_be_p(&chunk->type, type); 1943 stq_be_p(&chunk->cookie, request->cookie); 1944 stl_be_p(&chunk->length, length); 1945 } 1946 1947 static int coroutine_fn nbd_co_send_chunk_done(NBDClient *client, 1948 NBDRequest *request, 1949 Error **errp) 1950 { 1951 NBDReply hdr; 1952 struct iovec iov[] = { 1953 {.iov_base = &hdr}, 1954 }; 1955 1956 trace_nbd_co_send_chunk_done(request->cookie); 1957 set_be_chunk(client, iov, 1, NBD_REPLY_FLAG_DONE, 1958 NBD_REPLY_TYPE_NONE, request); 1959 return nbd_co_send_iov(client, iov, 1, errp); 1960 } 1961 1962 static int coroutine_fn nbd_co_send_chunk_read(NBDClient *client, 1963 NBDRequest *request, 1964 uint64_t offset, 1965 void *data, 1966 size_t size, 1967 bool final, 1968 Error **errp) 1969 { 1970 NBDReply hdr; 1971 NBDStructuredReadData chunk; 1972 struct iovec iov[] = { 1973 {.iov_base = &hdr}, 1974 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 1975 {.iov_base = data, .iov_len = size} 1976 }; 1977 1978 assert(size); 1979 trace_nbd_co_send_chunk_read(request->cookie, offset, data, size); 1980 set_be_chunk(client, iov, 3, final ? NBD_REPLY_FLAG_DONE : 0, 1981 NBD_REPLY_TYPE_OFFSET_DATA, request); 1982 stq_be_p(&chunk.offset, offset); 1983 1984 return nbd_co_send_iov(client, iov, 3, errp); 1985 } 1986 /*ebb*/ 1987 static int coroutine_fn nbd_co_send_chunk_error(NBDClient *client, 1988 NBDRequest *request, 1989 uint32_t error, 1990 const char *msg, 1991 Error **errp) 1992 { 1993 NBDReply hdr; 1994 NBDStructuredError chunk; 1995 int nbd_err = system_errno_to_nbd_errno(error); 1996 struct iovec iov[] = { 1997 {.iov_base = &hdr}, 1998 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 1999 {.iov_base = (char *)msg, .iov_len = msg ? strlen(msg) : 0}, 2000 }; 2001 2002 assert(nbd_err); 2003 trace_nbd_co_send_chunk_error(request->cookie, nbd_err, 2004 nbd_err_lookup(nbd_err), msg ? msg : ""); 2005 set_be_chunk(client, iov, 3, NBD_REPLY_FLAG_DONE, 2006 NBD_REPLY_TYPE_ERROR, request); 2007 stl_be_p(&chunk.error, nbd_err); 2008 stw_be_p(&chunk.message_length, iov[2].iov_len); 2009 2010 return nbd_co_send_iov(client, iov, 3, errp); 2011 } 2012 2013 /* Do a sparse read and send the structured reply to the client. 2014 * Returns -errno if sending fails. blk_co_block_status_above() failure is 2015 * reported to the client, at which point this function succeeds. 2016 */ 2017 static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, 2018 NBDRequest *request, 2019 uint64_t offset, 2020 uint8_t *data, 2021 size_t size, 2022 Error **errp) 2023 { 2024 int ret = 0; 2025 NBDExport *exp = client->exp; 2026 size_t progress = 0; 2027 2028 while (progress < size) { 2029 int64_t pnum; 2030 int status = blk_co_block_status_above(exp->common.blk, NULL, 2031 offset + progress, 2032 size - progress, &pnum, NULL, 2033 NULL); 2034 bool final; 2035 2036 if (status < 0) { 2037 char *msg = g_strdup_printf("unable to check for holes: %s", 2038 strerror(-status)); 2039 2040 ret = nbd_co_send_chunk_error(client, request, -status, msg, errp); 2041 g_free(msg); 2042 return ret; 2043 } 2044 assert(pnum && pnum <= size - progress); 2045 final = progress + pnum == size; 2046 if (status & BDRV_BLOCK_ZERO) { 2047 NBDReply hdr; 2048 NBDStructuredReadHole chunk; 2049 struct iovec iov[] = { 2050 {.iov_base = &hdr}, 2051 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 2052 }; 2053 2054 trace_nbd_co_send_chunk_read_hole(request->cookie, 2055 offset + progress, pnum); 2056 set_be_chunk(client, iov, 2, 2057 final ? NBD_REPLY_FLAG_DONE : 0, 2058 NBD_REPLY_TYPE_OFFSET_HOLE, request); 2059 stq_be_p(&chunk.offset, offset + progress); 2060 stl_be_p(&chunk.length, pnum); 2061 ret = nbd_co_send_iov(client, iov, 2, errp); 2062 } else { 2063 ret = blk_co_pread(exp->common.blk, offset + progress, pnum, 2064 data + progress, 0); 2065 if (ret < 0) { 2066 error_setg_errno(errp, -ret, "reading from file failed"); 2067 break; 2068 } 2069 ret = nbd_co_send_chunk_read(client, request, offset + progress, 2070 data + progress, pnum, final, errp); 2071 } 2072 2073 if (ret < 0) { 2074 break; 2075 } 2076 progress += pnum; 2077 } 2078 return ret; 2079 } 2080 2081 typedef struct NBDExtentArray { 2082 NBDExtent *extents; 2083 unsigned int nb_alloc; 2084 unsigned int count; 2085 uint64_t total_length; 2086 bool can_add; 2087 bool converted_to_be; 2088 } NBDExtentArray; 2089 2090 static NBDExtentArray *nbd_extent_array_new(unsigned int nb_alloc) 2091 { 2092 NBDExtentArray *ea = g_new0(NBDExtentArray, 1); 2093 2094 ea->nb_alloc = nb_alloc; 2095 ea->extents = g_new(NBDExtent, nb_alloc); 2096 ea->can_add = true; 2097 2098 return ea; 2099 } 2100 2101 static void nbd_extent_array_free(NBDExtentArray *ea) 2102 { 2103 g_free(ea->extents); 2104 g_free(ea); 2105 } 2106 G_DEFINE_AUTOPTR_CLEANUP_FUNC(NBDExtentArray, nbd_extent_array_free) 2107 2108 /* Further modifications of the array after conversion are abandoned */ 2109 static void nbd_extent_array_convert_to_be(NBDExtentArray *ea) 2110 { 2111 int i; 2112 2113 assert(!ea->converted_to_be); 2114 ea->can_add = false; 2115 ea->converted_to_be = true; 2116 2117 for (i = 0; i < ea->count; i++) { 2118 ea->extents[i].flags = cpu_to_be32(ea->extents[i].flags); 2119 ea->extents[i].length = cpu_to_be32(ea->extents[i].length); 2120 } 2121 } 2122 2123 /* 2124 * Add extent to NBDExtentArray. If extent can't be added (no available space), 2125 * return -1. 2126 * For safety, when returning -1 for the first time, .can_add is set to false, 2127 * and further calls to nbd_extent_array_add() will crash. 2128 * (this avoids the situation where a caller ignores failure to add one extent, 2129 * where adding another extent that would squash into the last array entry 2130 * would result in an incorrect range reported to the client) 2131 */ 2132 static int nbd_extent_array_add(NBDExtentArray *ea, 2133 uint32_t length, uint32_t flags) 2134 { 2135 assert(ea->can_add); 2136 2137 if (!length) { 2138 return 0; 2139 } 2140 2141 /* Extend previous extent if flags are the same */ 2142 if (ea->count > 0 && flags == ea->extents[ea->count - 1].flags) { 2143 uint64_t sum = (uint64_t)length + ea->extents[ea->count - 1].length; 2144 2145 if (sum <= UINT32_MAX) { 2146 ea->extents[ea->count - 1].length = sum; 2147 ea->total_length += length; 2148 return 0; 2149 } 2150 } 2151 2152 if (ea->count >= ea->nb_alloc) { 2153 ea->can_add = false; 2154 return -1; 2155 } 2156 2157 ea->total_length += length; 2158 ea->extents[ea->count] = (NBDExtent) {.length = length, .flags = flags}; 2159 ea->count++; 2160 2161 return 0; 2162 } 2163 2164 static int coroutine_fn blockstatus_to_extents(BlockBackend *blk, 2165 uint64_t offset, uint64_t bytes, 2166 NBDExtentArray *ea) 2167 { 2168 while (bytes) { 2169 uint32_t flags; 2170 int64_t num; 2171 int ret = blk_co_block_status_above(blk, NULL, offset, bytes, &num, 2172 NULL, NULL); 2173 2174 if (ret < 0) { 2175 return ret; 2176 } 2177 2178 flags = (ret & BDRV_BLOCK_DATA ? 0 : NBD_STATE_HOLE) | 2179 (ret & BDRV_BLOCK_ZERO ? NBD_STATE_ZERO : 0); 2180 2181 if (nbd_extent_array_add(ea, num, flags) < 0) { 2182 return 0; 2183 } 2184 2185 offset += num; 2186 bytes -= num; 2187 } 2188 2189 return 0; 2190 } 2191 2192 static int coroutine_fn blockalloc_to_extents(BlockBackend *blk, 2193 uint64_t offset, uint64_t bytes, 2194 NBDExtentArray *ea) 2195 { 2196 while (bytes) { 2197 int64_t num; 2198 int ret = blk_co_is_allocated_above(blk, NULL, false, offset, bytes, 2199 &num); 2200 2201 if (ret < 0) { 2202 return ret; 2203 } 2204 2205 if (nbd_extent_array_add(ea, num, ret) < 0) { 2206 return 0; 2207 } 2208 2209 offset += num; 2210 bytes -= num; 2211 } 2212 2213 return 0; 2214 } 2215 2216 /* 2217 * nbd_co_send_extents 2218 * 2219 * @ea is converted to BE by the function 2220 * @last controls whether NBD_REPLY_FLAG_DONE is sent. 2221 */ 2222 static int coroutine_fn 2223 nbd_co_send_extents(NBDClient *client, NBDRequest *request, NBDExtentArray *ea, 2224 bool last, uint32_t context_id, Error **errp) 2225 { 2226 NBDReply hdr; 2227 NBDStructuredMeta chunk; 2228 struct iovec iov[] = { 2229 {.iov_base = &hdr}, 2230 {.iov_base = &chunk, .iov_len = sizeof(chunk)}, 2231 {.iov_base = ea->extents, .iov_len = ea->count * sizeof(ea->extents[0])} 2232 }; 2233 2234 nbd_extent_array_convert_to_be(ea); 2235 2236 trace_nbd_co_send_extents(request->cookie, ea->count, context_id, 2237 ea->total_length, last); 2238 set_be_chunk(client, iov, 3, last ? NBD_REPLY_FLAG_DONE : 0, 2239 NBD_REPLY_TYPE_BLOCK_STATUS, request); 2240 stl_be_p(&chunk.context_id, context_id); 2241 2242 return nbd_co_send_iov(client, iov, 3, errp); 2243 } 2244 2245 /* Get block status from the exported device and send it to the client */ 2246 static int 2247 coroutine_fn nbd_co_send_block_status(NBDClient *client, NBDRequest *request, 2248 BlockBackend *blk, uint64_t offset, 2249 uint32_t length, bool dont_fragment, 2250 bool last, uint32_t context_id, 2251 Error **errp) 2252 { 2253 int ret; 2254 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS; 2255 g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents); 2256 2257 if (context_id == NBD_META_ID_BASE_ALLOCATION) { 2258 ret = blockstatus_to_extents(blk, offset, length, ea); 2259 } else { 2260 ret = blockalloc_to_extents(blk, offset, length, ea); 2261 } 2262 if (ret < 0) { 2263 return nbd_co_send_chunk_error(client, request, -ret, 2264 "can't get block status", errp); 2265 } 2266 2267 return nbd_co_send_extents(client, request, ea, last, context_id, errp); 2268 } 2269 2270 /* Populate @ea from a dirty bitmap. */ 2271 static void bitmap_to_extents(BdrvDirtyBitmap *bitmap, 2272 uint64_t offset, uint64_t length, 2273 NBDExtentArray *es) 2274 { 2275 int64_t start, dirty_start, dirty_count; 2276 int64_t end = offset + length; 2277 bool full = false; 2278 2279 bdrv_dirty_bitmap_lock(bitmap); 2280 2281 for (start = offset; 2282 bdrv_dirty_bitmap_next_dirty_area(bitmap, start, end, INT32_MAX, 2283 &dirty_start, &dirty_count); 2284 start = dirty_start + dirty_count) 2285 { 2286 if ((nbd_extent_array_add(es, dirty_start - start, 0) < 0) || 2287 (nbd_extent_array_add(es, dirty_count, NBD_STATE_DIRTY) < 0)) 2288 { 2289 full = true; 2290 break; 2291 } 2292 } 2293 2294 if (!full) { 2295 /* last non dirty extent, nothing to do if array is now full */ 2296 (void) nbd_extent_array_add(es, end - start, 0); 2297 } 2298 2299 bdrv_dirty_bitmap_unlock(bitmap); 2300 } 2301 2302 static int coroutine_fn nbd_co_send_bitmap(NBDClient *client, 2303 NBDRequest *request, 2304 BdrvDirtyBitmap *bitmap, 2305 uint64_t offset, 2306 uint32_t length, bool dont_fragment, 2307 bool last, uint32_t context_id, 2308 Error **errp) 2309 { 2310 unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS; 2311 g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents); 2312 2313 bitmap_to_extents(bitmap, offset, length, ea); 2314 2315 return nbd_co_send_extents(client, request, ea, last, context_id, errp); 2316 } 2317 2318 /* nbd_co_receive_request 2319 * Collect a client request. Return 0 if request looks valid, -EIO to drop 2320 * connection right away, -EAGAIN to indicate we were interrupted and the 2321 * channel should be quiesced, and any other negative value to report an error 2322 * to the client (although the caller may still need to disconnect after 2323 * reporting the error). 2324 */ 2325 static int coroutine_fn nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, 2326 Error **errp) 2327 { 2328 NBDClient *client = req->client; 2329 int valid_flags; 2330 int ret; 2331 2332 g_assert(qemu_in_coroutine()); 2333 assert(client->recv_coroutine == qemu_coroutine_self()); 2334 ret = nbd_receive_request(client, request, errp); 2335 if (ret < 0) { 2336 return ret; 2337 } 2338 2339 trace_nbd_co_receive_request_decode_type(request->cookie, request->type, 2340 nbd_cmd_lookup(request->type)); 2341 2342 if (request->type != NBD_CMD_WRITE) { 2343 /* No payload, we are ready to read the next request. */ 2344 req->complete = true; 2345 } 2346 2347 if (request->type == NBD_CMD_DISC) { 2348 /* Special case: we're going to disconnect without a reply, 2349 * whether or not flags, from, or len are bogus */ 2350 return -EIO; 2351 } 2352 2353 if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE || 2354 request->type == NBD_CMD_CACHE) 2355 { 2356 if (request->len > NBD_MAX_BUFFER_SIZE) { 2357 error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)", 2358 request->len, NBD_MAX_BUFFER_SIZE); 2359 return -EINVAL; 2360 } 2361 2362 if (request->type != NBD_CMD_CACHE) { 2363 req->data = blk_try_blockalign(client->exp->common.blk, 2364 request->len); 2365 if (req->data == NULL) { 2366 error_setg(errp, "No memory"); 2367 return -ENOMEM; 2368 } 2369 } 2370 } 2371 2372 if (request->type == NBD_CMD_WRITE) { 2373 if (nbd_read(client->ioc, req->data, request->len, "CMD_WRITE data", 2374 errp) < 0) 2375 { 2376 return -EIO; 2377 } 2378 req->complete = true; 2379 2380 trace_nbd_co_receive_request_payload_received(request->cookie, 2381 request->len); 2382 } 2383 2384 /* Sanity checks. */ 2385 if (client->exp->nbdflags & NBD_FLAG_READ_ONLY && 2386 (request->type == NBD_CMD_WRITE || 2387 request->type == NBD_CMD_WRITE_ZEROES || 2388 request->type == NBD_CMD_TRIM)) { 2389 error_setg(errp, "Export is read-only"); 2390 return -EROFS; 2391 } 2392 if (request->from > client->exp->size || 2393 request->len > client->exp->size - request->from) { 2394 error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32 2395 ", Size: %" PRIu64, request->from, request->len, 2396 client->exp->size); 2397 return (request->type == NBD_CMD_WRITE || 2398 request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL; 2399 } 2400 if (client->check_align && !QEMU_IS_ALIGNED(request->from | request->len, 2401 client->check_align)) { 2402 /* 2403 * The block layer gracefully handles unaligned requests, but 2404 * it's still worth tracing client non-compliance 2405 */ 2406 trace_nbd_co_receive_align_compliance(nbd_cmd_lookup(request->type), 2407 request->from, 2408 request->len, 2409 client->check_align); 2410 } 2411 valid_flags = NBD_CMD_FLAG_FUA; 2412 if (request->type == NBD_CMD_READ && client->structured_reply) { 2413 valid_flags |= NBD_CMD_FLAG_DF; 2414 } else if (request->type == NBD_CMD_WRITE_ZEROES) { 2415 valid_flags |= NBD_CMD_FLAG_NO_HOLE | NBD_CMD_FLAG_FAST_ZERO; 2416 } else if (request->type == NBD_CMD_BLOCK_STATUS) { 2417 valid_flags |= NBD_CMD_FLAG_REQ_ONE; 2418 } 2419 if (request->flags & ~valid_flags) { 2420 error_setg(errp, "unsupported flags for command %s (got 0x%x)", 2421 nbd_cmd_lookup(request->type), request->flags); 2422 return -EINVAL; 2423 } 2424 2425 return 0; 2426 } 2427 2428 /* Send simple reply without a payload, or a structured error 2429 * @error_msg is ignored if @ret >= 0 2430 * Returns 0 if connection is still live, -errno on failure to talk to client 2431 */ 2432 static coroutine_fn int nbd_send_generic_reply(NBDClient *client, 2433 NBDRequest *request, 2434 int ret, 2435 const char *error_msg, 2436 Error **errp) 2437 { 2438 if (client->structured_reply && ret < 0) { 2439 return nbd_co_send_chunk_error(client, request, -ret, error_msg, errp); 2440 } else { 2441 return nbd_co_send_simple_reply(client, request, ret < 0 ? -ret : 0, 2442 NULL, 0, errp); 2443 } 2444 } 2445 2446 /* Handle NBD_CMD_READ request. 2447 * Return -errno if sending fails. Other errors are reported directly to the 2448 * client as an error reply. */ 2449 static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, 2450 uint8_t *data, Error **errp) 2451 { 2452 int ret; 2453 NBDExport *exp = client->exp; 2454 2455 assert(request->type == NBD_CMD_READ); 2456 2457 /* XXX: NBD Protocol only documents use of FUA with WRITE */ 2458 if (request->flags & NBD_CMD_FLAG_FUA) { 2459 ret = blk_co_flush(exp->common.blk); 2460 if (ret < 0) { 2461 return nbd_send_generic_reply(client, request, ret, 2462 "flush failed", errp); 2463 } 2464 } 2465 2466 if (client->structured_reply && !(request->flags & NBD_CMD_FLAG_DF) && 2467 request->len) 2468 { 2469 return nbd_co_send_sparse_read(client, request, request->from, 2470 data, request->len, errp); 2471 } 2472 2473 ret = blk_co_pread(exp->common.blk, request->from, request->len, data, 0); 2474 if (ret < 0) { 2475 return nbd_send_generic_reply(client, request, ret, 2476 "reading from file failed", errp); 2477 } 2478 2479 if (client->structured_reply) { 2480 if (request->len) { 2481 return nbd_co_send_chunk_read(client, request, request->from, data, 2482 request->len, true, errp); 2483 } else { 2484 return nbd_co_send_chunk_done(client, request, errp); 2485 } 2486 } else { 2487 return nbd_co_send_simple_reply(client, request, 0, 2488 data, request->len, errp); 2489 } 2490 } 2491 2492 /* 2493 * nbd_do_cmd_cache 2494 * 2495 * Handle NBD_CMD_CACHE request. 2496 * Return -errno if sending fails. Other errors are reported directly to the 2497 * client as an error reply. 2498 */ 2499 static coroutine_fn int nbd_do_cmd_cache(NBDClient *client, NBDRequest *request, 2500 Error **errp) 2501 { 2502 int ret; 2503 NBDExport *exp = client->exp; 2504 2505 assert(request->type == NBD_CMD_CACHE); 2506 2507 ret = blk_co_preadv(exp->common.blk, request->from, request->len, 2508 NULL, BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH); 2509 2510 return nbd_send_generic_reply(client, request, ret, 2511 "caching data failed", errp); 2512 } 2513 2514 /* Handle NBD request. 2515 * Return -errno if sending fails. Other errors are reported directly to the 2516 * client as an error reply. */ 2517 static coroutine_fn int nbd_handle_request(NBDClient *client, 2518 NBDRequest *request, 2519 uint8_t *data, Error **errp) 2520 { 2521 int ret; 2522 int flags; 2523 NBDExport *exp = client->exp; 2524 char *msg; 2525 size_t i; 2526 2527 switch (request->type) { 2528 case NBD_CMD_CACHE: 2529 return nbd_do_cmd_cache(client, request, errp); 2530 2531 case NBD_CMD_READ: 2532 return nbd_do_cmd_read(client, request, data, errp); 2533 2534 case NBD_CMD_WRITE: 2535 flags = 0; 2536 if (request->flags & NBD_CMD_FLAG_FUA) { 2537 flags |= BDRV_REQ_FUA; 2538 } 2539 ret = blk_co_pwrite(exp->common.blk, request->from, request->len, data, 2540 flags); 2541 return nbd_send_generic_reply(client, request, ret, 2542 "writing to file failed", errp); 2543 2544 case NBD_CMD_WRITE_ZEROES: 2545 flags = 0; 2546 if (request->flags & NBD_CMD_FLAG_FUA) { 2547 flags |= BDRV_REQ_FUA; 2548 } 2549 if (!(request->flags & NBD_CMD_FLAG_NO_HOLE)) { 2550 flags |= BDRV_REQ_MAY_UNMAP; 2551 } 2552 if (request->flags & NBD_CMD_FLAG_FAST_ZERO) { 2553 flags |= BDRV_REQ_NO_FALLBACK; 2554 } 2555 ret = blk_co_pwrite_zeroes(exp->common.blk, request->from, request->len, 2556 flags); 2557 return nbd_send_generic_reply(client, request, ret, 2558 "writing to file failed", errp); 2559 2560 case NBD_CMD_DISC: 2561 /* unreachable, thanks to special case in nbd_co_receive_request() */ 2562 abort(); 2563 2564 case NBD_CMD_FLUSH: 2565 ret = blk_co_flush(exp->common.blk); 2566 return nbd_send_generic_reply(client, request, ret, 2567 "flush failed", errp); 2568 2569 case NBD_CMD_TRIM: 2570 ret = blk_co_pdiscard(exp->common.blk, request->from, request->len); 2571 if (ret >= 0 && request->flags & NBD_CMD_FLAG_FUA) { 2572 ret = blk_co_flush(exp->common.blk); 2573 } 2574 return nbd_send_generic_reply(client, request, ret, 2575 "discard failed", errp); 2576 2577 case NBD_CMD_BLOCK_STATUS: 2578 if (!request->len) { 2579 return nbd_send_generic_reply(client, request, -EINVAL, 2580 "need non-zero length", errp); 2581 } 2582 if (client->export_meta.count) { 2583 bool dont_fragment = request->flags & NBD_CMD_FLAG_REQ_ONE; 2584 int contexts_remaining = client->export_meta.count; 2585 2586 if (client->export_meta.base_allocation) { 2587 ret = nbd_co_send_block_status(client, request, 2588 exp->common.blk, 2589 request->from, 2590 request->len, dont_fragment, 2591 !--contexts_remaining, 2592 NBD_META_ID_BASE_ALLOCATION, 2593 errp); 2594 if (ret < 0) { 2595 return ret; 2596 } 2597 } 2598 2599 if (client->export_meta.allocation_depth) { 2600 ret = nbd_co_send_block_status(client, request, 2601 exp->common.blk, 2602 request->from, request->len, 2603 dont_fragment, 2604 !--contexts_remaining, 2605 NBD_META_ID_ALLOCATION_DEPTH, 2606 errp); 2607 if (ret < 0) { 2608 return ret; 2609 } 2610 } 2611 2612 for (i = 0; i < client->exp->nr_export_bitmaps; i++) { 2613 if (!client->export_meta.bitmaps[i]) { 2614 continue; 2615 } 2616 ret = nbd_co_send_bitmap(client, request, 2617 client->exp->export_bitmaps[i], 2618 request->from, request->len, 2619 dont_fragment, !--contexts_remaining, 2620 NBD_META_ID_DIRTY_BITMAP + i, errp); 2621 if (ret < 0) { 2622 return ret; 2623 } 2624 } 2625 2626 assert(!contexts_remaining); 2627 2628 return 0; 2629 } else { 2630 return nbd_send_generic_reply(client, request, -EINVAL, 2631 "CMD_BLOCK_STATUS not negotiated", 2632 errp); 2633 } 2634 2635 default: 2636 msg = g_strdup_printf("invalid request type (%" PRIu32 ") received", 2637 request->type); 2638 ret = nbd_send_generic_reply(client, request, -EINVAL, msg, 2639 errp); 2640 g_free(msg); 2641 return ret; 2642 } 2643 } 2644 2645 /* Owns a reference to the NBDClient passed as opaque. */ 2646 static coroutine_fn void nbd_trip(void *opaque) 2647 { 2648 NBDClient *client = opaque; 2649 NBDRequestData *req; 2650 NBDRequest request = { 0 }; /* GCC thinks it can be used uninitialized */ 2651 int ret; 2652 Error *local_err = NULL; 2653 2654 trace_nbd_trip(); 2655 if (client->closing) { 2656 nbd_client_put(client); 2657 return; 2658 } 2659 2660 if (client->quiescing) { 2661 /* 2662 * We're switching between AIO contexts. Don't attempt to receive a new 2663 * request and kick the main context which may be waiting for us. 2664 */ 2665 nbd_client_put(client); 2666 client->recv_coroutine = NULL; 2667 aio_wait_kick(); 2668 return; 2669 } 2670 2671 req = nbd_request_get(client); 2672 ret = nbd_co_receive_request(req, &request, &local_err); 2673 client->recv_coroutine = NULL; 2674 2675 if (client->closing) { 2676 /* 2677 * The client may be closed when we are blocked in 2678 * nbd_co_receive_request() 2679 */ 2680 goto done; 2681 } 2682 2683 if (ret == -EAGAIN) { 2684 assert(client->quiescing); 2685 goto done; 2686 } 2687 2688 nbd_client_receive_next_request(client); 2689 if (ret == -EIO) { 2690 goto disconnect; 2691 } 2692 2693 qio_channel_set_cork(client->ioc, true); 2694 2695 if (ret < 0) { 2696 /* It wasn't -EIO, so, according to nbd_co_receive_request() 2697 * semantics, we should return the error to the client. */ 2698 Error *export_err = local_err; 2699 2700 local_err = NULL; 2701 ret = nbd_send_generic_reply(client, &request, -EINVAL, 2702 error_get_pretty(export_err), &local_err); 2703 error_free(export_err); 2704 } else { 2705 ret = nbd_handle_request(client, &request, req->data, &local_err); 2706 } 2707 if (ret < 0) { 2708 error_prepend(&local_err, "Failed to send reply: "); 2709 goto disconnect; 2710 } 2711 2712 /* We must disconnect after NBD_CMD_WRITE if we did not 2713 * read the payload. 2714 */ 2715 if (!req->complete) { 2716 error_setg(&local_err, "Request handling failed in intermediate state"); 2717 goto disconnect; 2718 } 2719 2720 qio_channel_set_cork(client->ioc, false); 2721 done: 2722 nbd_request_put(req); 2723 nbd_client_put(client); 2724 return; 2725 2726 disconnect: 2727 if (local_err) { 2728 error_reportf_err(local_err, "Disconnect client, due to: "); 2729 } 2730 nbd_request_put(req); 2731 client_close(client, true); 2732 nbd_client_put(client); 2733 } 2734 2735 static void nbd_client_receive_next_request(NBDClient *client) 2736 { 2737 if (!client->recv_coroutine && client->nb_requests < MAX_NBD_REQUESTS && 2738 !client->quiescing) { 2739 nbd_client_get(client); 2740 client->recv_coroutine = qemu_coroutine_create(nbd_trip, client); 2741 aio_co_schedule(client->exp->common.ctx, client->recv_coroutine); 2742 } 2743 } 2744 2745 static coroutine_fn void nbd_co_client_start(void *opaque) 2746 { 2747 NBDClient *client = opaque; 2748 Error *local_err = NULL; 2749 2750 qemu_co_mutex_init(&client->send_lock); 2751 2752 if (nbd_negotiate(client, &local_err)) { 2753 if (local_err) { 2754 error_report_err(local_err); 2755 } 2756 client_close(client, false); 2757 return; 2758 } 2759 2760 nbd_client_receive_next_request(client); 2761 } 2762 2763 /* 2764 * Create a new client listener using the given channel @sioc. 2765 * Begin servicing it in a coroutine. When the connection closes, call 2766 * @close_fn with an indication of whether the client completed negotiation. 2767 */ 2768 void nbd_client_new(QIOChannelSocket *sioc, 2769 QCryptoTLSCreds *tlscreds, 2770 const char *tlsauthz, 2771 void (*close_fn)(NBDClient *, bool)) 2772 { 2773 NBDClient *client; 2774 Coroutine *co; 2775 2776 client = g_new0(NBDClient, 1); 2777 client->refcount = 1; 2778 client->tlscreds = tlscreds; 2779 if (tlscreds) { 2780 object_ref(OBJECT(client->tlscreds)); 2781 } 2782 client->tlsauthz = g_strdup(tlsauthz); 2783 client->sioc = sioc; 2784 qio_channel_set_delay(QIO_CHANNEL(sioc), false); 2785 object_ref(OBJECT(client->sioc)); 2786 client->ioc = QIO_CHANNEL(sioc); 2787 object_ref(OBJECT(client->ioc)); 2788 client->close_fn = close_fn; 2789 2790 co = qemu_coroutine_create(nbd_co_client_start, client); 2791 qemu_coroutine_enter(co); 2792 } 2793