block/nbd.c

   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     SocketAddressFlat *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.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.host", host);
 120
 121         port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT);
 122         qdict_put(options, "server.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.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.host", qstring_from_str(addr->host));
 211         qdict_put(options, "server.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.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.host", qstring_from_str(host));
 255         qdict_put(output_options, "server.port",
 256                   qstring_from_str(port ?: stringify(NBD_DEFAULT_PORT)));
 257     }
 258
 259     return true;
 260 }
 261
 262 static SocketAddressFlat *nbd_config(BDRVNBDState *s, QDict *options,
 263                                      Error **errp)
 264 {
 265     SocketAddressFlat *saddr = NULL;
 266     QDict *addr = NULL;
 267     QObject *crumpled_addr = NULL;
 268     Visitor *iv = NULL;
 269     Error *local_err = NULL;
 270
 271     qdict_extract_subqdict(options, &addr, "server.");
 272     if (!qdict_size(addr)) {
 273         error_setg(errp, "NBD server address missing");
 274         goto done;
 275     }
 276
 277     crumpled_addr = qdict_crumple(addr, errp);
 278     if (!crumpled_addr) {
 279         goto done;
 280     }
 281
 282     /*
 283      * FIXME .numeric, .to, .ipv4 or .ipv6 don't work with -drive
 284      * server.type=inet.  .to doesn't matter, it's ignored anyway.
 285      * That's because when @options come from -blockdev or
 286      * blockdev_add, members are typed according to the QAPI schema,
 287      * but when they come from -drive, they're all QString.  The
 288      * visitor expects the former.
 289      */
 290     iv = qobject_input_visitor_new(crumpled_addr);
 291     visit_type_SocketAddressFlat(iv, NULL, &saddr, &local_err);
 292     if (local_err) {
 293         error_propagate(errp, local_err);
 294         goto done;
 295     }
 296
 297 done:
 298     QDECREF(addr);
 299     qobject_decref(crumpled_addr);
 300     visit_free(iv);
 301     return saddr;
 302 }
 303
 304 NBDClientSession *nbd_get_client_session(BlockDriverState *bs)
 305 {
 306     BDRVNBDState *s = bs->opaque;
 307     return &s->client;
 308 }
 309
 310 static QIOChannelSocket *nbd_establish_connection(SocketAddressFlat *saddr_flat,
 311                                                   Error **errp)
 312 {
 313     SocketAddress *saddr = socket_address_crumple(saddr_flat);
 314     QIOChannelSocket *sioc;
 315     Error *local_err = NULL;
 316
 317     sioc = qio_channel_socket_new();
 318     qio_channel_set_name(QIO_CHANNEL(sioc), "nbd-client");
 319
 320     qio_channel_socket_connect_sync(sioc,
 321                                     saddr,
 322                                     &local_err);
 323     qapi_free_SocketAddress(saddr);
 324     if (local_err) {
 325         error_propagate(errp, local_err);
 326         return NULL;
 327     }
 328
 329     qio_channel_set_delay(QIO_CHANNEL(sioc), false);
 330
 331     return sioc;
 332 }
 333
 334
 335 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
 336 {
 337     Object *obj;
 338     QCryptoTLSCreds *creds;
 339
 340     obj = object_resolve_path_component(
 341         object_get_objects_root(), id);
 342     if (!obj) {
 343         error_setg(errp, "No TLS credentials with id '%s'",
 344                    id);
 345         return NULL;
 346     }
 347     creds = (QCryptoTLSCreds *)
 348         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 349     if (!creds) {
 350         error_setg(errp, "Object with id '%s' is not TLS credentials",
 351                    id);
 352         return NULL;
 353     }
 354
 355     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
 356         error_setg(errp,
 357                    "Expecting TLS credentials with a client endpoint");
 358         return NULL;
 359     }
 360     object_ref(obj);
 361     return creds;
 362 }
 363
 364
 365 static QemuOptsList nbd_runtime_opts = {
 366     .name = "nbd",
 367     .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head),
 368     .desc = {
 369         {
 370             .name = "host",
 371             .type = QEMU_OPT_STRING,
 372             .help = "TCP host to connect to",
 373         },
 374         {
 375             .name = "port",
 376             .type = QEMU_OPT_STRING,
 377             .help = "TCP port to connect to",
 378         },
 379         {
 380             .name = "path",
 381             .type = QEMU_OPT_STRING,
 382             .help = "Unix socket path to connect to",
 383         },
 384         {
 385             .name = "export",
 386             .type = QEMU_OPT_STRING,
 387             .help = "Name of the NBD export to open",
 388         },
 389         {
 390             .name = "tls-creds",
 391             .type = QEMU_OPT_STRING,
 392             .help = "ID of the TLS credentials to use",
 393         },
 394     },
 395 };
 396
 397 static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
 398                     Error **errp)
 399 {
 400     BDRVNBDState *s = bs->opaque;
 401     QemuOpts *opts = NULL;
 402     Error *local_err = NULL;
 403     QIOChannelSocket *sioc = NULL;
 404     QCryptoTLSCreds *tlscreds = NULL;
 405     const char *hostname = NULL;
 406     int ret = -EINVAL;
 407
 408     opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort);
 409     qemu_opts_absorb_qdict(opts, options, &local_err);
 410     if (local_err) {
 411         error_propagate(errp, local_err);
 412         goto error;
 413     }
 414
 415     /* Translate @host, @port, and @path to a SocketAddressFlat */
 416     if (!nbd_process_legacy_socket_options(options, opts, errp)) {
 417         goto error;
 418     }
 419
 420     /* Pop the config into our state object. Exit if invalid. */
 421     s->saddr = nbd_config(s, options, errp);
 422     if (!s->saddr) {
 423         goto error;
 424     }
 425
 426     s->export = g_strdup(qemu_opt_get(opts, "export"));
 427
 428     s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds"));
 429     if (s->tlscredsid) {
 430         tlscreds = nbd_get_tls_creds(s->tlscredsid, errp);
 431         if (!tlscreds) {
 432             goto error;
 433         }
 434
 435         /* TODO SOCKET_ADDRESS_KIND_FD where fd has AF_INET or AF_INET6 */
 436         if (s->saddr->type != SOCKET_ADDRESS_FLAT_TYPE_INET) {
 437             error_setg(errp, "TLS only supported over IP sockets");
 438             goto error;
 439         }
 440         hostname = s->saddr->u.inet.host;
 441     }
 442
 443     /* establish TCP connection, return error if it fails
 444      * TODO: Configurable retry-until-timeout behaviour.
 445      */
 446     sioc = nbd_establish_connection(s->saddr, errp);
 447     if (!sioc) {
 448         ret = -ECONNREFUSED;
 449         goto error;
 450     }
 451
 452     /* NBD handshake */
 453     ret = nbd_client_init(bs, sioc, s->export,
 454                           tlscreds, hostname, errp);
 455  error:
 456     if (sioc) {
 457         object_unref(OBJECT(sioc));
 458     }
 459     if (tlscreds) {
 460         object_unref(OBJECT(tlscreds));
 461     }
 462     if (ret < 0) {
 463         qapi_free_SocketAddressFlat(s->saddr);
 464         g_free(s->export);
 465         g_free(s->tlscredsid);
 466     }
 467     qemu_opts_del(opts);
 468     return ret;
 469 }
 470
 471 static int nbd_co_flush(BlockDriverState *bs)
 472 {
 473     return nbd_client_co_flush(bs);
 474 }
 475
 476 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
 477 {
 478     bs->bl.max_pdiscard = NBD_MAX_BUFFER_SIZE;
 479     bs->bl.max_pwrite_zeroes = NBD_MAX_BUFFER_SIZE;
 480     bs->bl.max_transfer = NBD_MAX_BUFFER_SIZE;
 481 }
 482
 483 static void nbd_close(BlockDriverState *bs)
 484 {
 485     BDRVNBDState *s = bs->opaque;
 486
 487     nbd_client_close(bs);
 488
 489     qapi_free_SocketAddressFlat(s->saddr);
 490     g_free(s->export);
 491     g_free(s->tlscredsid);
 492 }
 493
 494 static int64_t nbd_getlength(BlockDriverState *bs)
 495 {
 496     BDRVNBDState *s = bs->opaque;
 497
 498     return s->client.size;
 499 }
 500
 501 static void nbd_detach_aio_context(BlockDriverState *bs)
 502 {
 503     nbd_client_detach_aio_context(bs);
 504 }
 505
 506 static void nbd_attach_aio_context(BlockDriverState *bs,
 507                                    AioContext *new_context)
 508 {
 509     nbd_client_attach_aio_context(bs, new_context);
 510 }
 511
 512 static void nbd_refresh_filename(BlockDriverState *bs, QDict *options)
 513 {
 514     BDRVNBDState *s = bs->opaque;
 515     QDict *opts = qdict_new();
 516     QObject *saddr_qdict;
 517     Visitor *ov;
 518     const char *host = NULL, *port = NULL, *path = NULL;
 519
 520     if (s->saddr->type == SOCKET_ADDRESS_FLAT_TYPE_INET) {
 521         const InetSocketAddress *inet = &s->saddr->u.inet;
 522         if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) {
 523             host = inet->host;
 524             port = inet->port;
 525         }
 526     } else if (s->saddr->type == SOCKET_ADDRESS_FLAT_TYPE_UNIX) {
 527         path = s->saddr->u.q_unix.path;
 528     } /* else can't represent as pseudo-filename */
 529
 530     qdict_put(opts, "driver", qstring_from_str("nbd"));
 531
 532     if (path && s->export) {
 533         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 534                  "nbd+unix:///%s?socket=%s", s->export, path);
 535     } else if (path && !s->export) {
 536         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 537                  "nbd+unix://?socket=%s", path);
 538     } else if (host && s->export) {
 539         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 540                  "nbd://%s:%s/%s", host, port, s->export);
 541     } else if (host && !s->export) {
 542         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 543                  "nbd://%s:%s", host, port);
 544     }
 545
 546     ov = qobject_output_visitor_new(&saddr_qdict);
 547     visit_type_SocketAddressFlat(ov, NULL, &s->saddr, &error_abort);
 548     visit_complete(ov, &saddr_qdict);
 549     visit_free(ov);
 550     qdict_put_obj(opts, "server", saddr_qdict);
 551
 552     if (s->export) {
 553         qdict_put(opts, "export", qstring_from_str(s->export));
 554     }
 555     if (s->tlscredsid) {
 556         qdict_put(opts, "tls-creds", qstring_from_str(s->tlscredsid));
 557     }
 558
 559     qdict_flatten(opts);
 560     bs->full_open_options = opts;
 561 }
 562
 563 static BlockDriver bdrv_nbd = {
 564     .format_name                = "nbd",
 565     .protocol_name              = "nbd",
 566     .instance_size              = sizeof(BDRVNBDState),
 567     .bdrv_parse_filename        = nbd_parse_filename,
 568     .bdrv_file_open             = nbd_open,
 569     .bdrv_co_preadv             = nbd_client_co_preadv,
 570     .bdrv_co_pwritev            = nbd_client_co_pwritev,
 571     .bdrv_co_pwrite_zeroes      = nbd_client_co_pwrite_zeroes,
 572     .bdrv_close                 = nbd_close,
 573     .bdrv_co_flush_to_os        = nbd_co_flush,
 574     .bdrv_co_pdiscard           = nbd_client_co_pdiscard,
 575     .bdrv_refresh_limits        = nbd_refresh_limits,
 576     .bdrv_getlength             = nbd_getlength,
 577     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 578     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 579     .bdrv_refresh_filename      = nbd_refresh_filename,
 580 };
 581
 582 static BlockDriver bdrv_nbd_tcp = {
 583     .format_name                = "nbd",
 584     .protocol_name              = "nbd+tcp",
 585     .instance_size              = sizeof(BDRVNBDState),
 586     .bdrv_parse_filename        = nbd_parse_filename,
 587     .bdrv_file_open             = nbd_open,
 588     .bdrv_co_preadv             = nbd_client_co_preadv,
 589     .bdrv_co_pwritev            = nbd_client_co_pwritev,
 590     .bdrv_co_pwrite_zeroes      = nbd_client_co_pwrite_zeroes,
 591     .bdrv_close                 = nbd_close,
 592     .bdrv_co_flush_to_os        = nbd_co_flush,
 593     .bdrv_co_pdiscard           = nbd_client_co_pdiscard,
 594     .bdrv_refresh_limits        = nbd_refresh_limits,
 595     .bdrv_getlength             = nbd_getlength,
 596     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 597     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 598     .bdrv_refresh_filename      = nbd_refresh_filename,
 599 };
 600
 601 static BlockDriver bdrv_nbd_unix = {
 602     .format_name                = "nbd",
 603     .protocol_name              = "nbd+unix",
 604     .instance_size              = sizeof(BDRVNBDState),
 605     .bdrv_parse_filename        = nbd_parse_filename,
 606     .bdrv_file_open             = nbd_open,
 607     .bdrv_co_preadv             = nbd_client_co_preadv,
 608     .bdrv_co_pwritev            = nbd_client_co_pwritev,
 609     .bdrv_co_pwrite_zeroes      = nbd_client_co_pwrite_zeroes,
 610     .bdrv_close                 = nbd_close,
 611     .bdrv_co_flush_to_os        = nbd_co_flush,
 612     .bdrv_co_pdiscard           = nbd_client_co_pdiscard,
 613     .bdrv_refresh_limits        = nbd_refresh_limits,
 614     .bdrv_getlength             = nbd_getlength,
 615     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 616     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 617     .bdrv_refresh_filename      = nbd_refresh_filename,
 618 };
 619
 620 static void bdrv_nbd_init(void)
 621 {
 622     bdrv_register(&bdrv_nbd);
 623     bdrv_register(&bdrv_nbd_tcp);
 624     bdrv_register(&bdrv_nbd_unix);
 625 }
 626
 627 block_init(bdrv_nbd_init);