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/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 } BDRVNBDState;
  46
  47 static int nbd_parse_uri(const char *filename, QDict *options)
  48 {
  49     URI *uri;
  50     const char *p;
  51     QueryParams *qp = NULL;
  52     int ret = 0;
  53     bool is_unix;
  54
  55     uri = uri_parse(filename);
  56     if (!uri) {
  57         return -EINVAL;
  58     }
  59
  60     /* transport */
  61     if (!strcmp(uri->scheme, "nbd")) {
  62         is_unix = false;
  63     } else if (!strcmp(uri->scheme, "nbd+tcp")) {
  64         is_unix = false;
  65     } else if (!strcmp(uri->scheme, "nbd+unix")) {
  66         is_unix = true;
  67     } else {
  68         ret = -EINVAL;
  69         goto out;
  70     }
  71
  72     p = uri->path ? uri->path : "/";
  73     p += strspn(p, "/");
  74     if (p[0]) {
  75         qdict_put(options, "export", qstring_from_str(p));
  76     }
  77
  78     qp = query_params_parse(uri->query);
  79     if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) {
  80         ret = -EINVAL;
  81         goto out;
  82     }
  83
  84     if (is_unix) {
  85         /* nbd+unix:///export?socket=path */
  86         if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) {
  87             ret = -EINVAL;
  88             goto out;
  89         }
  90         qdict_put(options, "path", qstring_from_str(qp->p[0].value));
  91     } else {
  92         QString *host;
  93         /* nbd[+tcp]://host[:port]/export */
  94         if (!uri->server) {
  95             ret = -EINVAL;
  96             goto out;
  97         }
  98
  99         /* strip braces from literal IPv6 address */
 100         if (uri->server[0] == '[') {
 101             host = qstring_from_substr(uri->server, 1,
 102                                        strlen(uri->server) - 2);
 103         } else {
 104             host = qstring_from_str(uri->server);
 105         }
 106
 107         qdict_put(options, "host", host);
 108         if (uri->port) {
 109             char* port_str = g_strdup_printf("%d", uri->port);
 110             qdict_put(options, "port", qstring_from_str(port_str));
 111             g_free(port_str);
 112         }
 113     }
 114
 115 out:
 116     if (qp) {
 117         query_params_free(qp);
 118     }
 119     uri_free(uri);
 120     return ret;
 121 }
 122
 123 static void nbd_parse_filename(const char *filename, QDict *options,
 124                                Error **errp)
 125 {
 126     char *file;
 127     char *export_name;
 128     const char *host_spec;
 129     const char *unixpath;
 130
 131     if (qdict_haskey(options, "host")
 132         || qdict_haskey(options, "port")
 133         || qdict_haskey(options, "path"))
 134     {
 135         error_setg(errp, "host/port/path and a file name may not be specified "
 136                          "at the same time");
 137         return;
 138     }
 139
 140     if (strstr(filename, "://")) {
 141         int ret = nbd_parse_uri(filename, options);
 142         if (ret < 0) {
 143             error_setg(errp, "No valid URL specified");
 144         }
 145         return;
 146     }
 147
 148     file = g_strdup(filename);
 149
 150     export_name = strstr(file, EN_OPTSTR);
 151     if (export_name) {
 152         if (export_name[strlen(EN_OPTSTR)] == 0) {
 153             goto out;
 154         }
 155         export_name[0] = 0; /* truncate 'file' */
 156         export_name += strlen(EN_OPTSTR);
 157
 158         qdict_put(options, "export", qstring_from_str(export_name));
 159     }
 160
 161     /* extract the host_spec - fail if it's not nbd:... */
 162     if (!strstart(file, "nbd:", &host_spec)) {
 163         error_setg(errp, "File name string for NBD must start with 'nbd:'");
 164         goto out;
 165     }
 166
 167     if (!*host_spec) {
 168         goto out;
 169     }
 170
 171     /* are we a UNIX or TCP socket? */
 172     if (strstart(host_spec, "unix:", &unixpath)) {
 173         qdict_put(options, "path", qstring_from_str(unixpath));
 174     } else {
 175         InetSocketAddress *addr = NULL;
 176
 177         addr = inet_parse(host_spec, errp);
 178         if (!addr) {
 179             goto out;
 180         }
 181
 182         qdict_put(options, "host", qstring_from_str(addr->host));
 183         qdict_put(options, "port", qstring_from_str(addr->port));
 184         qapi_free_InetSocketAddress(addr);
 185     }
 186
 187 out:
 188     g_free(file);
 189 }
 190
 191 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, char **export,
 192                                  Error **errp)
 193 {
 194     SocketAddress *saddr;
 195
 196     if (qdict_haskey(options, "path") == qdict_haskey(options, "host")) {
 197         if (qdict_haskey(options, "path")) {
 198             error_setg(errp, "path and host may not be used at the same time.");
 199         } else {
 200             error_setg(errp, "one of path and host must be specified.");
 201         }
 202         return NULL;
 203     }
 204
 205     saddr = g_new0(SocketAddress, 1);
 206
 207     if (qdict_haskey(options, "path")) {
 208         UnixSocketAddress *q_unix;
 209         saddr->type = SOCKET_ADDRESS_KIND_UNIX;
 210         q_unix = saddr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
 211         q_unix->path = g_strdup(qdict_get_str(options, "path"));
 212         qdict_del(options, "path");
 213     } else {
 214         InetSocketAddress *inet;
 215         saddr->type = SOCKET_ADDRESS_KIND_INET;
 216         inet = saddr->u.inet.data = g_new0(InetSocketAddress, 1);
 217         inet->host = g_strdup(qdict_get_str(options, "host"));
 218         if (!qdict_get_try_str(options, "port")) {
 219             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 220         } else {
 221             inet->port = g_strdup(qdict_get_str(options, "port"));
 222         }
 223         qdict_del(options, "host");
 224         qdict_del(options, "port");
 225     }
 226
 227     s->client.is_unix = saddr->type == SOCKET_ADDRESS_KIND_UNIX;
 228
 229     *export = g_strdup(qdict_get_try_str(options, "export"));
 230     if (*export) {
 231         qdict_del(options, "export");
 232     }
 233
 234     return saddr;
 235 }
 236
 237 NbdClientSession *nbd_get_client_session(BlockDriverState *bs)
 238 {
 239     BDRVNBDState *s = bs->opaque;
 240     return &s->client;
 241 }
 242
 243 static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr,
 244                                                   Error **errp)
 245 {
 246     QIOChannelSocket *sioc;
 247     Error *local_err = NULL;
 248
 249     sioc = qio_channel_socket_new();
 250
 251     qio_channel_socket_connect_sync(sioc,
 252                                     saddr,
 253                                     &local_err);
 254     if (local_err) {
 255         error_propagate(errp, local_err);
 256         return NULL;
 257     }
 258
 259     qio_channel_set_delay(QIO_CHANNEL(sioc), false);
 260
 261     return sioc;
 262 }
 263
 264
 265 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
 266 {
 267     Object *obj;
 268     QCryptoTLSCreds *creds;
 269
 270     obj = object_resolve_path_component(
 271         object_get_objects_root(), id);
 272     if (!obj) {
 273         error_setg(errp, "No TLS credentials with id '%s'",
 274                    id);
 275         return NULL;
 276     }
 277     creds = (QCryptoTLSCreds *)
 278         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 279     if (!creds) {
 280         error_setg(errp, "Object with id '%s' is not TLS credentials",
 281                    id);
 282         return NULL;
 283     }
 284
 285     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
 286         error_setg(errp,
 287                    "Expecting TLS credentials with a client endpoint");
 288         return NULL;
 289     }
 290     object_ref(obj);
 291     return creds;
 292 }
 293
 294
 295 static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
 296                     Error **errp)
 297 {
 298     BDRVNBDState *s = bs->opaque;
 299     char *export = NULL;
 300     QIOChannelSocket *sioc = NULL;
 301     SocketAddress *saddr;
 302     const char *tlscredsid;
 303     QCryptoTLSCreds *tlscreds = NULL;
 304     const char *hostname = NULL;
 305     int ret = -EINVAL;
 306
 307     /* Pop the config into our state object. Exit if invalid. */
 308     saddr = nbd_config(s, options, &export, errp);
 309     if (!saddr) {
 310         goto error;
 311     }
 312
 313     tlscredsid = g_strdup(qdict_get_try_str(options, "tls-creds"));
 314     if (tlscredsid) {
 315         qdict_del(options, "tls-creds");
 316         tlscreds = nbd_get_tls_creds(tlscredsid, errp);
 317         if (!tlscreds) {
 318             goto error;
 319         }
 320
 321         if (saddr->type != SOCKET_ADDRESS_KIND_INET) {
 322             error_setg(errp, "TLS only supported over IP sockets");
 323             goto error;
 324         }
 325         hostname = saddr->u.inet.data->host;
 326     }
 327
 328     /* establish TCP connection, return error if it fails
 329      * TODO: Configurable retry-until-timeout behaviour.
 330      */
 331     sioc = nbd_establish_connection(saddr, errp);
 332     if (!sioc) {
 333         ret = -ECONNREFUSED;
 334         goto error;
 335     }
 336
 337     /* NBD handshake */
 338     ret = nbd_client_init(bs, sioc, export,
 339                           tlscreds, hostname, errp);
 340  error:
 341     if (sioc) {
 342         object_unref(OBJECT(sioc));
 343     }
 344     if (tlscreds) {
 345         object_unref(OBJECT(tlscreds));
 346     }
 347     qapi_free_SocketAddress(saddr);
 348     g_free(export);
 349     return ret;
 350 }
 351
 352 static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num,
 353                         int nb_sectors, QEMUIOVector *qiov)
 354 {
 355     return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov);
 356 }
 357
 358 static int nbd_co_writev_flags(BlockDriverState *bs, int64_t sector_num,
 359                                int nb_sectors, QEMUIOVector *qiov, int flags)
 360 {
 361     int ret;
 362
 363     ret = nbd_client_co_writev(bs, sector_num, nb_sectors, qiov, &flags);
 364     if (ret < 0) {
 365         return ret;
 366     }
 367
 368     /* The flag wasn't sent to the server, so we need to emulate it with an
 369      * explicit flush */
 370     if (flags & BDRV_REQ_FUA) {
 371         ret = nbd_client_co_flush(bs);
 372     }
 373
 374     return ret;
 375 }
 376
 377 static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num,
 378                          int nb_sectors, QEMUIOVector *qiov)
 379 {
 380     return nbd_co_writev_flags(bs, sector_num, nb_sectors, qiov, 0);
 381 }
 382
 383 static int nbd_co_flush(BlockDriverState *bs)
 384 {
 385     return nbd_client_co_flush(bs);
 386 }
 387
 388 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
 389 {
 390     bs->bl.max_discard = UINT32_MAX >> BDRV_SECTOR_BITS;
 391     bs->bl.max_transfer_length = UINT32_MAX >> BDRV_SECTOR_BITS;
 392 }
 393
 394 static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num,
 395                           int nb_sectors)
 396 {
 397     return nbd_client_co_discard(bs, sector_num, nb_sectors);
 398 }
 399
 400 static void nbd_close(BlockDriverState *bs)
 401 {
 402     nbd_client_close(bs);
 403 }
 404
 405 static int64_t nbd_getlength(BlockDriverState *bs)
 406 {
 407     BDRVNBDState *s = bs->opaque;
 408
 409     return s->client.size;
 410 }
 411
 412 static void nbd_detach_aio_context(BlockDriverState *bs)
 413 {
 414     nbd_client_detach_aio_context(bs);
 415 }
 416
 417 static void nbd_attach_aio_context(BlockDriverState *bs,
 418                                    AioContext *new_context)
 419 {
 420     nbd_client_attach_aio_context(bs, new_context);
 421 }
 422
 423 static void nbd_refresh_filename(BlockDriverState *bs, QDict *options)
 424 {
 425     QDict *opts = qdict_new();
 426     const char *path   = qdict_get_try_str(options, "path");
 427     const char *host   = qdict_get_try_str(options, "host");
 428     const char *port   = qdict_get_try_str(options, "port");
 429     const char *export = qdict_get_try_str(options, "export");
 430     const char *tlscreds = qdict_get_try_str(options, "tls-creds");
 431
 432     qdict_put_obj(opts, "driver", QOBJECT(qstring_from_str("nbd")));
 433
 434     if (path && export) {
 435         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 436                  "nbd+unix:///%s?socket=%s", export, path);
 437     } else if (path && !export) {
 438         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 439                  "nbd+unix://?socket=%s", path);
 440     } else if (!path && export && port) {
 441         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 442                  "nbd://%s:%s/%s", host, port, export);
 443     } else if (!path && export && !port) {
 444         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 445                  "nbd://%s/%s", host, export);
 446     } else if (!path && !export && port) {
 447         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 448                  "nbd://%s:%s", host, port);
 449     } else if (!path && !export && !port) {
 450         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 451                  "nbd://%s", host);
 452     }
 453
 454     if (path) {
 455         qdict_put_obj(opts, "path", QOBJECT(qstring_from_str(path)));
 456     } else if (port) {
 457         qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
 458         qdict_put_obj(opts, "port", QOBJECT(qstring_from_str(port)));
 459     } else {
 460         qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
 461     }
 462     if (export) {
 463         qdict_put_obj(opts, "export", QOBJECT(qstring_from_str(export)));
 464     }
 465     if (tlscreds) {
 466         qdict_put_obj(opts, "tls-creds", QOBJECT(qstring_from_str(tlscreds)));
 467     }
 468
 469     bs->full_open_options = opts;
 470 }
 471
 472 static BlockDriver bdrv_nbd = {
 473     .format_name                = "nbd",
 474     .protocol_name              = "nbd",
 475     .instance_size              = sizeof(BDRVNBDState),
 476     .bdrv_parse_filename        = nbd_parse_filename,
 477     .bdrv_file_open             = nbd_open,
 478     .bdrv_co_readv              = nbd_co_readv,
 479     .bdrv_co_writev             = nbd_co_writev,
 480     .bdrv_co_writev_flags       = nbd_co_writev_flags,
 481     .supported_write_flags      = BDRV_REQ_FUA,
 482     .bdrv_close                 = nbd_close,
 483     .bdrv_co_flush_to_os        = nbd_co_flush,
 484     .bdrv_co_discard            = nbd_co_discard,
 485     .bdrv_refresh_limits        = nbd_refresh_limits,
 486     .bdrv_getlength             = nbd_getlength,
 487     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 488     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 489     .bdrv_refresh_filename      = nbd_refresh_filename,
 490 };
 491
 492 static BlockDriver bdrv_nbd_tcp = {
 493     .format_name                = "nbd",
 494     .protocol_name              = "nbd+tcp",
 495     .instance_size              = sizeof(BDRVNBDState),
 496     .bdrv_parse_filename        = nbd_parse_filename,
 497     .bdrv_file_open             = nbd_open,
 498     .bdrv_co_readv              = nbd_co_readv,
 499     .bdrv_co_writev             = nbd_co_writev,
 500     .bdrv_co_writev_flags       = nbd_co_writev_flags,
 501     .supported_write_flags      = BDRV_REQ_FUA,
 502     .bdrv_close                 = nbd_close,
 503     .bdrv_co_flush_to_os        = nbd_co_flush,
 504     .bdrv_co_discard            = nbd_co_discard,
 505     .bdrv_refresh_limits        = nbd_refresh_limits,
 506     .bdrv_getlength             = nbd_getlength,
 507     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 508     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 509     .bdrv_refresh_filename      = nbd_refresh_filename,
 510 };
 511
 512 static BlockDriver bdrv_nbd_unix = {
 513     .format_name                = "nbd",
 514     .protocol_name              = "nbd+unix",
 515     .instance_size              = sizeof(BDRVNBDState),
 516     .bdrv_parse_filename        = nbd_parse_filename,
 517     .bdrv_file_open             = nbd_open,
 518     .bdrv_co_readv              = nbd_co_readv,
 519     .bdrv_co_writev             = nbd_co_writev,
 520     .bdrv_co_writev_flags       = nbd_co_writev_flags,
 521     .supported_write_flags      = BDRV_REQ_FUA,
 522     .bdrv_close                 = nbd_close,
 523     .bdrv_co_flush_to_os        = nbd_co_flush,
 524     .bdrv_co_discard            = nbd_co_discard,
 525     .bdrv_refresh_limits        = nbd_refresh_limits,
 526     .bdrv_getlength             = nbd_getlength,
 527     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 528     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 529     .bdrv_refresh_filename      = nbd_refresh_filename,
 530 };
 531
 532 static void bdrv_nbd_init(void)
 533 {
 534     bdrv_register(&bdrv_nbd);
 535     bdrv_register(&bdrv_nbd_tcp);
 536     bdrv_register(&bdrv_nbd_unix);
 537 }
 538
 539 block_init(bdrv_nbd_init);