1 /* 2 * QEMU Block driver for NBD 3 * 4 * Copyright (C) 2008 Bull S.A.S. 5 * Author: Laurent Vivier <Laurent.Vivier@bull.net> 6 * 7 * Some parts: 8 * Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws> 9 * 10 * Permission is hereby granted, free of charge, to any person obtaining a copy 11 * of this software and associated documentation files (the "Software"), to deal 12 * in the Software without restriction, including without limitation the rights 13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 14 * copies of the Software, and to permit persons to whom the Software is 15 * furnished to do so, subject to the following conditions: 16 * 17 * The above copyright notice and this permission notice shall be included in 18 * all copies or substantial portions of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 26 * THE SOFTWARE. 27 */ 28 29 #include "qemu/osdep.h" 30 #include "block/nbd-client.h" 31 #include "qapi/error.h" 32 #include "qemu/uri.h" 33 #include "block/block_int.h" 34 #include "qemu/module.h" 35 #include "qapi-visit.h" 36 #include "qapi/qobject-input-visitor.h" 37 #include "qapi/qobject-output-visitor.h" 38 #include "qapi/qmp/qdict.h" 39 #include "qapi/qmp/qjson.h" 40 #include "qapi/qmp/qint.h" 41 #include "qapi/qmp/qstring.h" 42 #include "qemu/cutils.h" 43 44 #define EN_OPTSTR ":exportname=" 45 46 typedef struct BDRVNBDState { 47 NBDClientSession client; 48 49 /* For nbd_refresh_filename() */ 50 SocketAddress *saddr; 51 char *export, *tlscredsid; 52 } BDRVNBDState; 53 54 static int nbd_parse_uri(const char *filename, QDict *options) 55 { 56 URI *uri; 57 const char *p; 58 QueryParams *qp = NULL; 59 int ret = 0; 60 bool is_unix; 61 62 uri = uri_parse(filename); 63 if (!uri) { 64 return -EINVAL; 65 } 66 67 /* transport */ 68 if (!strcmp(uri->scheme, "nbd")) { 69 is_unix = false; 70 } else if (!strcmp(uri->scheme, "nbd+tcp")) { 71 is_unix = false; 72 } else if (!strcmp(uri->scheme, "nbd+unix")) { 73 is_unix = true; 74 } else { 75 ret = -EINVAL; 76 goto out; 77 } 78 79 p = uri->path ? uri->path : "/"; 80 p += strspn(p, "/"); 81 if (p[0]) { 82 qdict_put(options, "export", qstring_from_str(p)); 83 } 84 85 qp = query_params_parse(uri->query); 86 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 87 ret = -EINVAL; 88 goto out; 89 } 90 91 if (is_unix) { 92 /* nbd+unix:///export?socket=path */ 93 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 94 ret = -EINVAL; 95 goto out; 96 } 97 qdict_put(options, "server.type", qstring_from_str("unix")); 98 qdict_put(options, "server.data.path", 99 qstring_from_str(qp->p[0].value)); 100 } else { 101 QString *host; 102 char *port_str; 103 104 /* nbd[+tcp]://host[:port]/export */ 105 if (!uri->server) { 106 ret = -EINVAL; 107 goto out; 108 } 109 110 /* strip braces from literal IPv6 address */ 111 if (uri->server[0] == '[') { 112 host = qstring_from_substr(uri->server, 1, 113 strlen(uri->server) - 2); 114 } else { 115 host = qstring_from_str(uri->server); 116 } 117 118 qdict_put(options, "server.type", qstring_from_str("inet")); 119 qdict_put(options, "server.data.host", host); 120 121 port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT); 122 qdict_put(options, "server.data.port", qstring_from_str(port_str)); 123 g_free(port_str); 124 } 125 126 out: 127 if (qp) { 128 query_params_free(qp); 129 } 130 uri_free(uri); 131 return ret; 132 } 133 134 static bool nbd_has_filename_options_conflict(QDict *options, Error **errp) 135 { 136 const QDictEntry *e; 137 138 for (e = qdict_first(options); e; e = qdict_next(options, e)) { 139 if (!strcmp(e->key, "host") || 140 !strcmp(e->key, "port") || 141 !strcmp(e->key, "path") || 142 !strcmp(e->key, "export") || 143 strstart(e->key, "server.", NULL)) 144 { 145 error_setg(errp, "Option '%s' cannot be used with a file name", 146 e->key); 147 return true; 148 } 149 } 150 151 return false; 152 } 153 154 static void nbd_parse_filename(const char *filename, QDict *options, 155 Error **errp) 156 { 157 char *file; 158 char *export_name; 159 const char *host_spec; 160 const char *unixpath; 161 162 if (nbd_has_filename_options_conflict(options, errp)) { 163 return; 164 } 165 166 if (strstr(filename, "://")) { 167 int ret = nbd_parse_uri(filename, options); 168 if (ret < 0) { 169 error_setg(errp, "No valid URL specified"); 170 } 171 return; 172 } 173 174 file = g_strdup(filename); 175 176 export_name = strstr(file, EN_OPTSTR); 177 if (export_name) { 178 if (export_name[strlen(EN_OPTSTR)] == 0) { 179 goto out; 180 } 181 export_name[0] = 0; /* truncate 'file' */ 182 export_name += strlen(EN_OPTSTR); 183 184 qdict_put(options, "export", qstring_from_str(export_name)); 185 } 186 187 /* extract the host_spec - fail if it's not nbd:... */ 188 if (!strstart(file, "nbd:", &host_spec)) { 189 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 190 goto out; 191 } 192 193 if (!*host_spec) { 194 goto out; 195 } 196 197 /* are we a UNIX or TCP socket? */ 198 if (strstart(host_spec, "unix:", &unixpath)) { 199 qdict_put(options, "server.type", qstring_from_str("unix")); 200 qdict_put(options, "server.data.path", qstring_from_str(unixpath)); 201 } else { 202 InetSocketAddress *addr = NULL; 203 204 addr = inet_parse(host_spec, errp); 205 if (!addr) { 206 goto out; 207 } 208 209 qdict_put(options, "server.type", qstring_from_str("inet")); 210 qdict_put(options, "server.data.host", qstring_from_str(addr->host)); 211 qdict_put(options, "server.data.port", qstring_from_str(addr->port)); 212 qapi_free_InetSocketAddress(addr); 213 } 214 215 out: 216 g_free(file); 217 } 218 219 static bool nbd_process_legacy_socket_options(QDict *output_options, 220 QemuOpts *legacy_opts, 221 Error **errp) 222 { 223 const char *path = qemu_opt_get(legacy_opts, "path"); 224 const char *host = qemu_opt_get(legacy_opts, "host"); 225 const char *port = qemu_opt_get(legacy_opts, "port"); 226 const QDictEntry *e; 227 228 if (!path && !host && !port) { 229 return true; 230 } 231 232 for (e = qdict_first(output_options); e; e = qdict_next(output_options, e)) 233 { 234 if (strstart(e->key, "server.", NULL)) { 235 error_setg(errp, "Cannot use 'server' and path/host/port at the " 236 "same time"); 237 return false; 238 } 239 } 240 241 if (path && host) { 242 error_setg(errp, "path and host may not be used at the same time"); 243 return false; 244 } else if (path) { 245 if (port) { 246 error_setg(errp, "port may not be used without host"); 247 return false; 248 } 249 250 qdict_put(output_options, "server.type", qstring_from_str("unix")); 251 qdict_put(output_options, "server.data.path", qstring_from_str(path)); 252 } else if (host) { 253 qdict_put(output_options, "server.type", qstring_from_str("inet")); 254 qdict_put(output_options, "server.data.host", qstring_from_str(host)); 255 qdict_put(output_options, "server.data.port", 256 qstring_from_str(port ?: stringify(NBD_DEFAULT_PORT))); 257 } 258 259 return true; 260 } 261 262 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, Error **errp) 263 { 264 SocketAddress *saddr = NULL; 265 QDict *addr = NULL; 266 QObject *crumpled_addr = NULL; 267 Visitor *iv = NULL; 268 Error *local_err = NULL; 269 270 qdict_extract_subqdict(options, &addr, "server."); 271 if (!qdict_size(addr)) { 272 error_setg(errp, "NBD server address missing"); 273 goto done; 274 } 275 276 crumpled_addr = qdict_crumple(addr, errp); 277 if (!crumpled_addr) { 278 goto done; 279 } 280 281 iv = qobject_input_visitor_new(crumpled_addr); 282 visit_type_SocketAddress(iv, NULL, &saddr, &local_err); 283 if (local_err) { 284 error_propagate(errp, local_err); 285 goto done; 286 } 287 288 done: 289 QDECREF(addr); 290 qobject_decref(crumpled_addr); 291 visit_free(iv); 292 return saddr; 293 } 294 295 NBDClientSession *nbd_get_client_session(BlockDriverState *bs) 296 { 297 BDRVNBDState *s = bs->opaque; 298 return &s->client; 299 } 300 301 static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr, 302 Error **errp) 303 { 304 QIOChannelSocket *sioc; 305 Error *local_err = NULL; 306 307 sioc = qio_channel_socket_new(); 308 qio_channel_set_name(QIO_CHANNEL(sioc), "nbd-client"); 309 310 qio_channel_socket_connect_sync(sioc, 311 saddr, 312 &local_err); 313 if (local_err) { 314 error_propagate(errp, local_err); 315 return NULL; 316 } 317 318 qio_channel_set_delay(QIO_CHANNEL(sioc), false); 319 320 return sioc; 321 } 322 323 324 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 325 { 326 Object *obj; 327 QCryptoTLSCreds *creds; 328 329 obj = object_resolve_path_component( 330 object_get_objects_root(), id); 331 if (!obj) { 332 error_setg(errp, "No TLS credentials with id '%s'", 333 id); 334 return NULL; 335 } 336 creds = (QCryptoTLSCreds *) 337 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 338 if (!creds) { 339 error_setg(errp, "Object with id '%s' is not TLS credentials", 340 id); 341 return NULL; 342 } 343 344 if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) { 345 error_setg(errp, 346 "Expecting TLS credentials with a client endpoint"); 347 return NULL; 348 } 349 object_ref(obj); 350 return creds; 351 } 352 353 354 static QemuOptsList nbd_runtime_opts = { 355 .name = "nbd", 356 .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), 357 .desc = { 358 { 359 .name = "host", 360 .type = QEMU_OPT_STRING, 361 .help = "TCP host to connect to", 362 }, 363 { 364 .name = "port", 365 .type = QEMU_OPT_STRING, 366 .help = "TCP port to connect to", 367 }, 368 { 369 .name = "path", 370 .type = QEMU_OPT_STRING, 371 .help = "Unix socket path to connect to", 372 }, 373 { 374 .name = "export", 375 .type = QEMU_OPT_STRING, 376 .help = "Name of the NBD export to open", 377 }, 378 { 379 .name = "tls-creds", 380 .type = QEMU_OPT_STRING, 381 .help = "ID of the TLS credentials to use", 382 }, 383 }, 384 }; 385 386 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 387 Error **errp) 388 { 389 BDRVNBDState *s = bs->opaque; 390 QemuOpts *opts = NULL; 391 Error *local_err = NULL; 392 QIOChannelSocket *sioc = NULL; 393 QCryptoTLSCreds *tlscreds = NULL; 394 const char *hostname = NULL; 395 int ret = -EINVAL; 396 397 opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); 398 qemu_opts_absorb_qdict(opts, options, &local_err); 399 if (local_err) { 400 error_propagate(errp, local_err); 401 goto error; 402 } 403 404 /* Translate @host, @port, and @path to a SocketAddress */ 405 if (!nbd_process_legacy_socket_options(options, opts, errp)) { 406 goto error; 407 } 408 409 /* Pop the config into our state object. Exit if invalid. */ 410 s->saddr = nbd_config(s, options, errp); 411 if (!s->saddr) { 412 goto error; 413 } 414 415 s->export = g_strdup(qemu_opt_get(opts, "export")); 416 417 s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); 418 if (s->tlscredsid) { 419 tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); 420 if (!tlscreds) { 421 goto error; 422 } 423 424 if (s->saddr->type != SOCKET_ADDRESS_KIND_INET) { 425 error_setg(errp, "TLS only supported over IP sockets"); 426 goto error; 427 } 428 hostname = s->saddr->u.inet.data->host; 429 } 430 431 /* establish TCP connection, return error if it fails 432 * TODO: Configurable retry-until-timeout behaviour. 433 */ 434 sioc = nbd_establish_connection(s->saddr, errp); 435 if (!sioc) { 436 ret = -ECONNREFUSED; 437 goto error; 438 } 439 440 /* NBD handshake */ 441 ret = nbd_client_init(bs, sioc, s->export, 442 tlscreds, hostname, errp); 443 error: 444 if (sioc) { 445 object_unref(OBJECT(sioc)); 446 } 447 if (tlscreds) { 448 object_unref(OBJECT(tlscreds)); 449 } 450 if (ret < 0) { 451 qapi_free_SocketAddress(s->saddr); 452 g_free(s->export); 453 g_free(s->tlscredsid); 454 } 455 qemu_opts_del(opts); 456 return ret; 457 } 458 459 static int nbd_co_flush(BlockDriverState *bs) 460 { 461 return nbd_client_co_flush(bs); 462 } 463 464 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 465 { 466 bs->bl.max_pdiscard = NBD_MAX_BUFFER_SIZE; 467 bs->bl.max_pwrite_zeroes = NBD_MAX_BUFFER_SIZE; 468 bs->bl.max_transfer = NBD_MAX_BUFFER_SIZE; 469 } 470 471 static void nbd_close(BlockDriverState *bs) 472 { 473 BDRVNBDState *s = bs->opaque; 474 475 nbd_client_close(bs); 476 477 qapi_free_SocketAddress(s->saddr); 478 g_free(s->export); 479 g_free(s->tlscredsid); 480 } 481 482 static int64_t nbd_getlength(BlockDriverState *bs) 483 { 484 BDRVNBDState *s = bs->opaque; 485 486 return s->client.size; 487 } 488 489 static void nbd_detach_aio_context(BlockDriverState *bs) 490 { 491 nbd_client_detach_aio_context(bs); 492 } 493 494 static void nbd_attach_aio_context(BlockDriverState *bs, 495 AioContext *new_context) 496 { 497 nbd_client_attach_aio_context(bs, new_context); 498 } 499 500 static void nbd_refresh_filename(BlockDriverState *bs, QDict *options) 501 { 502 BDRVNBDState *s = bs->opaque; 503 QDict *opts = qdict_new(); 504 QObject *saddr_qdict; 505 Visitor *ov; 506 const char *host = NULL, *port = NULL, *path = NULL; 507 508 if (s->saddr->type == SOCKET_ADDRESS_KIND_INET) { 509 const InetSocketAddress *inet = s->saddr->u.inet.data; 510 if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) { 511 host = inet->host; 512 port = inet->port; 513 } 514 } else if (s->saddr->type == SOCKET_ADDRESS_KIND_UNIX) { 515 path = s->saddr->u.q_unix.data->path; 516 } 517 518 qdict_put(opts, "driver", qstring_from_str("nbd")); 519 520 if (path && s->export) { 521 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 522 "nbd+unix:///%s?socket=%s", s->export, path); 523 } else if (path && !s->export) { 524 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 525 "nbd+unix://?socket=%s", path); 526 } else if (host && s->export) { 527 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 528 "nbd://%s:%s/%s", host, port, s->export); 529 } else if (host && !s->export) { 530 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 531 "nbd://%s:%s", host, port); 532 } 533 534 ov = qobject_output_visitor_new(&saddr_qdict); 535 visit_type_SocketAddress(ov, NULL, &s->saddr, &error_abort); 536 visit_complete(ov, &saddr_qdict); 537 visit_free(ov); 538 qdict_put_obj(opts, "server", saddr_qdict); 539 540 if (s->export) { 541 qdict_put(opts, "export", qstring_from_str(s->export)); 542 } 543 if (s->tlscredsid) { 544 qdict_put(opts, "tls-creds", qstring_from_str(s->tlscredsid)); 545 } 546 547 qdict_flatten(opts); 548 bs->full_open_options = opts; 549 } 550 551 static BlockDriver bdrv_nbd = { 552 .format_name = "nbd", 553 .protocol_name = "nbd", 554 .instance_size = sizeof(BDRVNBDState), 555 .bdrv_parse_filename = nbd_parse_filename, 556 .bdrv_file_open = nbd_open, 557 .bdrv_co_preadv = nbd_client_co_preadv, 558 .bdrv_co_pwritev = nbd_client_co_pwritev, 559 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 560 .bdrv_close = nbd_close, 561 .bdrv_co_flush_to_os = nbd_co_flush, 562 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 563 .bdrv_refresh_limits = nbd_refresh_limits, 564 .bdrv_getlength = nbd_getlength, 565 .bdrv_detach_aio_context = nbd_detach_aio_context, 566 .bdrv_attach_aio_context = nbd_attach_aio_context, 567 .bdrv_refresh_filename = nbd_refresh_filename, 568 }; 569 570 static BlockDriver bdrv_nbd_tcp = { 571 .format_name = "nbd", 572 .protocol_name = "nbd+tcp", 573 .instance_size = sizeof(BDRVNBDState), 574 .bdrv_parse_filename = nbd_parse_filename, 575 .bdrv_file_open = nbd_open, 576 .bdrv_co_preadv = nbd_client_co_preadv, 577 .bdrv_co_pwritev = nbd_client_co_pwritev, 578 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 579 .bdrv_close = nbd_close, 580 .bdrv_co_flush_to_os = nbd_co_flush, 581 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 582 .bdrv_refresh_limits = nbd_refresh_limits, 583 .bdrv_getlength = nbd_getlength, 584 .bdrv_detach_aio_context = nbd_detach_aio_context, 585 .bdrv_attach_aio_context = nbd_attach_aio_context, 586 .bdrv_refresh_filename = nbd_refresh_filename, 587 }; 588 589 static BlockDriver bdrv_nbd_unix = { 590 .format_name = "nbd", 591 .protocol_name = "nbd+unix", 592 .instance_size = sizeof(BDRVNBDState), 593 .bdrv_parse_filename = nbd_parse_filename, 594 .bdrv_file_open = nbd_open, 595 .bdrv_co_preadv = nbd_client_co_preadv, 596 .bdrv_co_pwritev = nbd_client_co_pwritev, 597 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 598 .bdrv_close = nbd_close, 599 .bdrv_co_flush_to_os = nbd_co_flush, 600 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 601 .bdrv_refresh_limits = nbd_refresh_limits, 602 .bdrv_getlength = nbd_getlength, 603 .bdrv_detach_aio_context = nbd_detach_aio_context, 604 .bdrv_attach_aio_context = nbd_attach_aio_context, 605 .bdrv_refresh_filename = nbd_refresh_filename, 606 }; 607 608 static void bdrv_nbd_init(void) 609 { 610 bdrv_register(&bdrv_nbd); 611 bdrv_register(&bdrv_nbd_tcp); 612 bdrv_register(&bdrv_nbd_unix); 613 } 614 615 block_init(bdrv_nbd_init); 616