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/qmp/qdict.h" 36 #include "qapi/qmp/qjson.h" 37 #include "qapi/qmp/qint.h" 38 #include "qapi/qmp/qstring.h" 39 #include "qemu/cutils.h" 40 41 #define EN_OPTSTR ":exportname=" 42 43 typedef struct BDRVNBDState { 44 NbdClientSession client; 45 46 /* For nbd_refresh_filename() */ 47 char *path, *host, *port, *export, *tlscredsid; 48 } BDRVNBDState; 49 50 static int nbd_parse_uri(const char *filename, QDict *options) 51 { 52 URI *uri; 53 const char *p; 54 QueryParams *qp = NULL; 55 int ret = 0; 56 bool is_unix; 57 58 uri = uri_parse(filename); 59 if (!uri) { 60 return -EINVAL; 61 } 62 63 /* transport */ 64 if (!strcmp(uri->scheme, "nbd")) { 65 is_unix = false; 66 } else if (!strcmp(uri->scheme, "nbd+tcp")) { 67 is_unix = false; 68 } else if (!strcmp(uri->scheme, "nbd+unix")) { 69 is_unix = true; 70 } else { 71 ret = -EINVAL; 72 goto out; 73 } 74 75 p = uri->path ? uri->path : "/"; 76 p += strspn(p, "/"); 77 if (p[0]) { 78 qdict_put(options, "export", qstring_from_str(p)); 79 } 80 81 qp = query_params_parse(uri->query); 82 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 83 ret = -EINVAL; 84 goto out; 85 } 86 87 if (is_unix) { 88 /* nbd+unix:///export?socket=path */ 89 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 90 ret = -EINVAL; 91 goto out; 92 } 93 qdict_put(options, "path", qstring_from_str(qp->p[0].value)); 94 } else { 95 QString *host; 96 /* nbd[+tcp]://host[:port]/export */ 97 if (!uri->server) { 98 ret = -EINVAL; 99 goto out; 100 } 101 102 /* strip braces from literal IPv6 address */ 103 if (uri->server[0] == '[') { 104 host = qstring_from_substr(uri->server, 1, 105 strlen(uri->server) - 2); 106 } else { 107 host = qstring_from_str(uri->server); 108 } 109 110 qdict_put(options, "host", host); 111 if (uri->port) { 112 char* port_str = g_strdup_printf("%d", uri->port); 113 qdict_put(options, "port", qstring_from_str(port_str)); 114 g_free(port_str); 115 } 116 } 117 118 out: 119 if (qp) { 120 query_params_free(qp); 121 } 122 uri_free(uri); 123 return ret; 124 } 125 126 static void nbd_parse_filename(const char *filename, QDict *options, 127 Error **errp) 128 { 129 char *file; 130 char *export_name; 131 const char *host_spec; 132 const char *unixpath; 133 134 if (qdict_haskey(options, "host") 135 || qdict_haskey(options, "port") 136 || qdict_haskey(options, "path")) 137 { 138 error_setg(errp, "host/port/path and a file name may not be specified " 139 "at the same time"); 140 return; 141 } 142 143 if (strstr(filename, "://")) { 144 int ret = nbd_parse_uri(filename, options); 145 if (ret < 0) { 146 error_setg(errp, "No valid URL specified"); 147 } 148 return; 149 } 150 151 file = g_strdup(filename); 152 153 export_name = strstr(file, EN_OPTSTR); 154 if (export_name) { 155 if (export_name[strlen(EN_OPTSTR)] == 0) { 156 goto out; 157 } 158 export_name[0] = 0; /* truncate 'file' */ 159 export_name += strlen(EN_OPTSTR); 160 161 qdict_put(options, "export", qstring_from_str(export_name)); 162 } 163 164 /* extract the host_spec - fail if it's not nbd:... */ 165 if (!strstart(file, "nbd:", &host_spec)) { 166 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 167 goto out; 168 } 169 170 if (!*host_spec) { 171 goto out; 172 } 173 174 /* are we a UNIX or TCP socket? */ 175 if (strstart(host_spec, "unix:", &unixpath)) { 176 qdict_put(options, "path", qstring_from_str(unixpath)); 177 } else { 178 InetSocketAddress *addr = NULL; 179 180 addr = inet_parse(host_spec, errp); 181 if (!addr) { 182 goto out; 183 } 184 185 qdict_put(options, "host", qstring_from_str(addr->host)); 186 qdict_put(options, "port", qstring_from_str(addr->port)); 187 qapi_free_InetSocketAddress(addr); 188 } 189 190 out: 191 g_free(file); 192 } 193 194 static SocketAddress *nbd_config(BDRVNBDState *s, QemuOpts *opts, Error **errp) 195 { 196 SocketAddress *saddr; 197 198 s->path = g_strdup(qemu_opt_get(opts, "path")); 199 s->host = g_strdup(qemu_opt_get(opts, "host")); 200 201 if (!s->path == !s->host) { 202 if (s->path) { 203 error_setg(errp, "path and host may not be used at the same time."); 204 } else { 205 error_setg(errp, "one of path and host must be specified."); 206 } 207 return NULL; 208 } 209 210 saddr = g_new0(SocketAddress, 1); 211 212 if (s->path) { 213 UnixSocketAddress *q_unix; 214 saddr->type = SOCKET_ADDRESS_KIND_UNIX; 215 q_unix = saddr->u.q_unix.data = g_new0(UnixSocketAddress, 1); 216 q_unix->path = g_strdup(s->path); 217 } else { 218 InetSocketAddress *inet; 219 220 s->port = g_strdup(qemu_opt_get(opts, "port")); 221 222 saddr->type = SOCKET_ADDRESS_KIND_INET; 223 inet = saddr->u.inet.data = g_new0(InetSocketAddress, 1); 224 inet->host = g_strdup(s->host); 225 inet->port = g_strdup(s->port); 226 if (!inet->port) { 227 inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT); 228 } 229 } 230 231 s->client.is_unix = saddr->type == SOCKET_ADDRESS_KIND_UNIX; 232 233 s->export = g_strdup(qemu_opt_get(opts, "export")); 234 235 return saddr; 236 } 237 238 NbdClientSession *nbd_get_client_session(BlockDriverState *bs) 239 { 240 BDRVNBDState *s = bs->opaque; 241 return &s->client; 242 } 243 244 static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr, 245 Error **errp) 246 { 247 QIOChannelSocket *sioc; 248 Error *local_err = NULL; 249 250 sioc = qio_channel_socket_new(); 251 252 qio_channel_socket_connect_sync(sioc, 253 saddr, 254 &local_err); 255 if (local_err) { 256 error_propagate(errp, local_err); 257 return NULL; 258 } 259 260 qio_channel_set_delay(QIO_CHANNEL(sioc), false); 261 262 return sioc; 263 } 264 265 266 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 267 { 268 Object *obj; 269 QCryptoTLSCreds *creds; 270 271 obj = object_resolve_path_component( 272 object_get_objects_root(), id); 273 if (!obj) { 274 error_setg(errp, "No TLS credentials with id '%s'", 275 id); 276 return NULL; 277 } 278 creds = (QCryptoTLSCreds *) 279 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 280 if (!creds) { 281 error_setg(errp, "Object with id '%s' is not TLS credentials", 282 id); 283 return NULL; 284 } 285 286 if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) { 287 error_setg(errp, 288 "Expecting TLS credentials with a client endpoint"); 289 return NULL; 290 } 291 object_ref(obj); 292 return creds; 293 } 294 295 296 static QemuOptsList nbd_runtime_opts = { 297 .name = "nbd", 298 .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), 299 .desc = { 300 { 301 .name = "host", 302 .type = QEMU_OPT_STRING, 303 .help = "TCP host to connect to", 304 }, 305 { 306 .name = "port", 307 .type = QEMU_OPT_STRING, 308 .help = "TCP port to connect to", 309 }, 310 { 311 .name = "path", 312 .type = QEMU_OPT_STRING, 313 .help = "Unix socket path to connect to", 314 }, 315 { 316 .name = "export", 317 .type = QEMU_OPT_STRING, 318 .help = "Name of the NBD export to open", 319 }, 320 { 321 .name = "tls-creds", 322 .type = QEMU_OPT_STRING, 323 .help = "ID of the TLS credentials to use", 324 }, 325 }, 326 }; 327 328 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 329 Error **errp) 330 { 331 BDRVNBDState *s = bs->opaque; 332 QemuOpts *opts = NULL; 333 Error *local_err = NULL; 334 QIOChannelSocket *sioc = NULL; 335 SocketAddress *saddr = NULL; 336 QCryptoTLSCreds *tlscreds = NULL; 337 const char *hostname = NULL; 338 int ret = -EINVAL; 339 340 opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); 341 qemu_opts_absorb_qdict(opts, options, &local_err); 342 if (local_err) { 343 error_propagate(errp, local_err); 344 goto error; 345 } 346 347 /* Pop the config into our state object. Exit if invalid. */ 348 saddr = nbd_config(s, opts, errp); 349 if (!saddr) { 350 goto error; 351 } 352 353 s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); 354 if (s->tlscredsid) { 355 tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); 356 if (!tlscreds) { 357 goto error; 358 } 359 360 if (saddr->type != SOCKET_ADDRESS_KIND_INET) { 361 error_setg(errp, "TLS only supported over IP sockets"); 362 goto error; 363 } 364 hostname = saddr->u.inet.data->host; 365 } 366 367 /* establish TCP connection, return error if it fails 368 * TODO: Configurable retry-until-timeout behaviour. 369 */ 370 sioc = nbd_establish_connection(saddr, errp); 371 if (!sioc) { 372 ret = -ECONNREFUSED; 373 goto error; 374 } 375 376 /* NBD handshake */ 377 ret = nbd_client_init(bs, sioc, s->export, 378 tlscreds, hostname, errp); 379 error: 380 if (sioc) { 381 object_unref(OBJECT(sioc)); 382 } 383 if (tlscreds) { 384 object_unref(OBJECT(tlscreds)); 385 } 386 if (ret < 0) { 387 g_free(s->path); 388 g_free(s->host); 389 g_free(s->port); 390 g_free(s->export); 391 g_free(s->tlscredsid); 392 } 393 qapi_free_SocketAddress(saddr); 394 qemu_opts_del(opts); 395 return ret; 396 } 397 398 static int nbd_co_flush(BlockDriverState *bs) 399 { 400 return nbd_client_co_flush(bs); 401 } 402 403 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 404 { 405 bs->bl.max_pdiscard = NBD_MAX_BUFFER_SIZE; 406 bs->bl.max_transfer = NBD_MAX_BUFFER_SIZE; 407 } 408 409 static void nbd_close(BlockDriverState *bs) 410 { 411 BDRVNBDState *s = bs->opaque; 412 413 nbd_client_close(bs); 414 415 g_free(s->path); 416 g_free(s->host); 417 g_free(s->port); 418 g_free(s->export); 419 g_free(s->tlscredsid); 420 } 421 422 static int64_t nbd_getlength(BlockDriverState *bs) 423 { 424 BDRVNBDState *s = bs->opaque; 425 426 return s->client.size; 427 } 428 429 static void nbd_detach_aio_context(BlockDriverState *bs) 430 { 431 nbd_client_detach_aio_context(bs); 432 } 433 434 static void nbd_attach_aio_context(BlockDriverState *bs, 435 AioContext *new_context) 436 { 437 nbd_client_attach_aio_context(bs, new_context); 438 } 439 440 static void nbd_refresh_filename(BlockDriverState *bs, QDict *options) 441 { 442 BDRVNBDState *s = bs->opaque; 443 QDict *opts = qdict_new(); 444 445 qdict_put_obj(opts, "driver", QOBJECT(qstring_from_str("nbd"))); 446 447 if (s->path && s->export) { 448 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 449 "nbd+unix:///%s?socket=%s", s->export, s->path); 450 } else if (s->path && !s->export) { 451 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 452 "nbd+unix://?socket=%s", s->path); 453 } else if (!s->path && s->export && s->port) { 454 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 455 "nbd://%s:%s/%s", s->host, s->port, s->export); 456 } else if (!s->path && s->export && !s->port) { 457 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 458 "nbd://%s/%s", s->host, s->export); 459 } else if (!s->path && !s->export && s->port) { 460 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 461 "nbd://%s:%s", s->host, s->port); 462 } else if (!s->path && !s->export && !s->port) { 463 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 464 "nbd://%s", s->host); 465 } 466 467 if (s->path) { 468 qdict_put_obj(opts, "path", QOBJECT(qstring_from_str(s->path))); 469 } else if (s->port) { 470 qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(s->host))); 471 qdict_put_obj(opts, "port", QOBJECT(qstring_from_str(s->port))); 472 } else { 473 qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(s->host))); 474 } 475 if (s->export) { 476 qdict_put_obj(opts, "export", QOBJECT(qstring_from_str(s->export))); 477 } 478 if (s->tlscredsid) { 479 qdict_put_obj(opts, "tls-creds", 480 QOBJECT(qstring_from_str(s->tlscredsid))); 481 } 482 483 bs->full_open_options = opts; 484 } 485 486 static BlockDriver bdrv_nbd = { 487 .format_name = "nbd", 488 .protocol_name = "nbd", 489 .instance_size = sizeof(BDRVNBDState), 490 .bdrv_parse_filename = nbd_parse_filename, 491 .bdrv_file_open = nbd_open, 492 .bdrv_co_preadv = nbd_client_co_preadv, 493 .bdrv_co_pwritev = nbd_client_co_pwritev, 494 .bdrv_close = nbd_close, 495 .bdrv_co_flush_to_os = nbd_co_flush, 496 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 497 .bdrv_refresh_limits = nbd_refresh_limits, 498 .bdrv_getlength = nbd_getlength, 499 .bdrv_detach_aio_context = nbd_detach_aio_context, 500 .bdrv_attach_aio_context = nbd_attach_aio_context, 501 .bdrv_refresh_filename = nbd_refresh_filename, 502 }; 503 504 static BlockDriver bdrv_nbd_tcp = { 505 .format_name = "nbd", 506 .protocol_name = "nbd+tcp", 507 .instance_size = sizeof(BDRVNBDState), 508 .bdrv_parse_filename = nbd_parse_filename, 509 .bdrv_file_open = nbd_open, 510 .bdrv_co_preadv = nbd_client_co_preadv, 511 .bdrv_co_pwritev = nbd_client_co_pwritev, 512 .bdrv_close = nbd_close, 513 .bdrv_co_flush_to_os = nbd_co_flush, 514 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 515 .bdrv_refresh_limits = nbd_refresh_limits, 516 .bdrv_getlength = nbd_getlength, 517 .bdrv_detach_aio_context = nbd_detach_aio_context, 518 .bdrv_attach_aio_context = nbd_attach_aio_context, 519 .bdrv_refresh_filename = nbd_refresh_filename, 520 }; 521 522 static BlockDriver bdrv_nbd_unix = { 523 .format_name = "nbd", 524 .protocol_name = "nbd+unix", 525 .instance_size = sizeof(BDRVNBDState), 526 .bdrv_parse_filename = nbd_parse_filename, 527 .bdrv_file_open = nbd_open, 528 .bdrv_co_preadv = nbd_client_co_preadv, 529 .bdrv_co_pwritev = nbd_client_co_pwritev, 530 .bdrv_close = nbd_close, 531 .bdrv_co_flush_to_os = nbd_co_flush, 532 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 533 .bdrv_refresh_limits = nbd_refresh_limits, 534 .bdrv_getlength = nbd_getlength, 535 .bdrv_detach_aio_context = nbd_detach_aio_context, 536 .bdrv_attach_aio_context = nbd_attach_aio_context, 537 .bdrv_refresh_filename = nbd_refresh_filename, 538 }; 539 540 static void bdrv_nbd_init(void) 541 { 542 bdrv_register(&bdrv_nbd); 543 bdrv_register(&bdrv_nbd_tcp); 544 bdrv_register(&bdrv_nbd_unix); 545 } 546 547 block_init(bdrv_nbd_init); 548