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 "qemu/uri.h"
  32 #include "block/block_int.h"
  33 #include "qemu/module.h"
  34 #include "qapi/qmp/qdict.h"
  35 #include "qapi/qmp/qjson.h"
  36 #include "qapi/qmp/qint.h"
  37 #include "qapi/qmp/qstring.h"
  38
  39
  40 #define EN_OPTSTR ":exportname="
  41
  42 typedef struct BDRVNBDState {
  43     NbdClientSession client;
  44 } BDRVNBDState;
  45
  46 static int nbd_parse_uri(const char *filename, QDict *options)
  47 {
  48     URI *uri;
  49     const char *p;
  50     QueryParams *qp = NULL;
  51     int ret = 0;
  52     bool is_unix;
  53
  54     uri = uri_parse(filename);
  55     if (!uri) {
  56         return -EINVAL;
  57     }
  58
  59     /* transport */
  60     if (!strcmp(uri->scheme, "nbd")) {
  61         is_unix = false;
  62     } else if (!strcmp(uri->scheme, "nbd+tcp")) {
  63         is_unix = false;
  64     } else if (!strcmp(uri->scheme, "nbd+unix")) {
  65         is_unix = true;
  66     } else {
  67         ret = -EINVAL;
  68         goto out;
  69     }
  70
  71     p = uri->path ? uri->path : "/";
  72     p += strspn(p, "/");
  73     if (p[0]) {
  74         qdict_put(options, "export", qstring_from_str(p));
  75     }
  76
  77     qp = query_params_parse(uri->query);
  78     if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) {
  79         ret = -EINVAL;
  80         goto out;
  81     }
  82
  83     if (is_unix) {
  84         /* nbd+unix:///export?socket=path */
  85         if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) {
  86             ret = -EINVAL;
  87             goto out;
  88         }
  89         qdict_put(options, "path", qstring_from_str(qp->p[0].value));
  90     } else {
  91         QString *host;
  92         /* nbd[+tcp]://host[:port]/export */
  93         if (!uri->server) {
  94             ret = -EINVAL;
  95             goto out;
  96         }
  97
  98         /* strip braces from literal IPv6 address */
  99         if (uri->server[0] == '[') {
 100             host = qstring_from_substr(uri->server, 1,
 101                                        strlen(uri->server) - 2);
 102         } else {
 103             host = qstring_from_str(uri->server);
 104         }
 105
 106         qdict_put(options, "host", host);
 107         if (uri->port) {
 108             char* port_str = g_strdup_printf("%d", uri->port);
 109             qdict_put(options, "port", qstring_from_str(port_str));
 110             g_free(port_str);
 111         }
 112     }
 113
 114 out:
 115     if (qp) {
 116         query_params_free(qp);
 117     }
 118     uri_free(uri);
 119     return ret;
 120 }
 121
 122 static void nbd_parse_filename(const char *filename, QDict *options,
 123                                Error **errp)
 124 {
 125     char *file;
 126     char *export_name;
 127     const char *host_spec;
 128     const char *unixpath;
 129
 130     if (qdict_haskey(options, "host")
 131         || qdict_haskey(options, "port")
 132         || qdict_haskey(options, "path"))
 133     {
 134         error_setg(errp, "host/port/path and a file name may not be specified "
 135                          "at the same time");
 136         return;
 137     }
 138
 139     if (strstr(filename, "://")) {
 140         int ret = nbd_parse_uri(filename, options);
 141         if (ret < 0) {
 142             error_setg(errp, "No valid URL specified");
 143         }
 144         return;
 145     }
 146
 147     file = g_strdup(filename);
 148
 149     export_name = strstr(file, EN_OPTSTR);
 150     if (export_name) {
 151         if (export_name[strlen(EN_OPTSTR)] == 0) {
 152             goto out;
 153         }
 154         export_name[0] = 0; /* truncate 'file' */
 155         export_name += strlen(EN_OPTSTR);
 156
 157         qdict_put(options, "export", qstring_from_str(export_name));
 158     }
 159
 160     /* extract the host_spec - fail if it's not nbd:... */
 161     if (!strstart(file, "nbd:", &host_spec)) {
 162         error_setg(errp, "File name string for NBD must start with 'nbd:'");
 163         goto out;
 164     }
 165
 166     if (!*host_spec) {
 167         goto out;
 168     }
 169
 170     /* are we a UNIX or TCP socket? */
 171     if (strstart(host_spec, "unix:", &unixpath)) {
 172         qdict_put(options, "path", qstring_from_str(unixpath));
 173     } else {
 174         InetSocketAddress *addr = NULL;
 175
 176         addr = inet_parse(host_spec, errp);
 177         if (!addr) {
 178             goto out;
 179         }
 180
 181         qdict_put(options, "host", qstring_from_str(addr->host));
 182         qdict_put(options, "port", qstring_from_str(addr->port));
 183         qapi_free_InetSocketAddress(addr);
 184     }
 185
 186 out:
 187     g_free(file);
 188 }
 189
 190 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, char **export,
 191                                  Error **errp)
 192 {
 193     SocketAddress *saddr;
 194
 195     if (qdict_haskey(options, "path") == qdict_haskey(options, "host")) {
 196         if (qdict_haskey(options, "path")) {
 197             error_setg(errp, "path and host may not be used at the same time.");
 198         } else {
 199             error_setg(errp, "one of path and host must be specified.");
 200         }
 201         return NULL;
 202     }
 203
 204     saddr = g_new0(SocketAddress, 1);
 205
 206     if (qdict_haskey(options, "path")) {
 207         UnixSocketAddress *q_unix;
 208         saddr->type = SOCKET_ADDRESS_KIND_UNIX;
 209         q_unix = saddr->u.q_unix = g_new0(UnixSocketAddress, 1);
 210         q_unix->path = g_strdup(qdict_get_str(options, "path"));
 211         qdict_del(options, "path");
 212     } else {
 213         InetSocketAddress *inet;
 214         saddr->type = SOCKET_ADDRESS_KIND_INET;
 215         inet = saddr->u.inet = g_new0(InetSocketAddress, 1);
 216         inet->host = g_strdup(qdict_get_str(options, "host"));
 217         if (!qdict_get_try_str(options, "port")) {
 218             inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 219         } else {
 220             inet->port = g_strdup(qdict_get_str(options, "port"));
 221         }
 222         qdict_del(options, "host");
 223         qdict_del(options, "port");
 224     }
 225
 226     s->client.is_unix = saddr->type == SOCKET_ADDRESS_KIND_UNIX;
 227
 228     *export = g_strdup(qdict_get_try_str(options, "export"));
 229     if (*export) {
 230         qdict_del(options, "export");
 231     }
 232
 233     return saddr;
 234 }
 235
 236 NbdClientSession *nbd_get_client_session(BlockDriverState *bs)
 237 {
 238     BDRVNBDState *s = bs->opaque;
 239     return &s->client;
 240 }
 241
 242 static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr,
 243                                                   Error **errp)
 244 {
 245     QIOChannelSocket *sioc;
 246     Error *local_err = NULL;
 247
 248     sioc = qio_channel_socket_new();
 249
 250     qio_channel_socket_connect_sync(sioc,
 251                                     saddr,
 252                                     &local_err);
 253     if (local_err) {
 254         error_propagate(errp, local_err);
 255         return NULL;
 256     }
 257
 258     qio_channel_set_delay(QIO_CHANNEL(sioc), false);
 259
 260     return sioc;
 261 }
 262
 263
 264 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
 265 {
 266     Object *obj;
 267     QCryptoTLSCreds *creds;
 268
 269     obj = object_resolve_path_component(
 270         object_get_objects_root(), id);
 271     if (!obj) {
 272         error_setg(errp, "No TLS credentials with id '%s'",
 273                    id);
 274         return NULL;
 275     }
 276     creds = (QCryptoTLSCreds *)
 277         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 278     if (!creds) {
 279         error_setg(errp, "Object with id '%s' is not TLS credentials",
 280                    id);
 281         return NULL;
 282     }
 283
 284     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
 285         error_setg(errp,
 286                    "Expecting TLS credentials with a client endpoint");
 287         return NULL;
 288     }
 289     object_ref(obj);
 290     return creds;
 291 }
 292
 293
 294 static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
 295                     Error **errp)
 296 {
 297     BDRVNBDState *s = bs->opaque;
 298     char *export = NULL;
 299     QIOChannelSocket *sioc = NULL;
 300     SocketAddress *saddr;
 301     const char *tlscredsid;
 302     QCryptoTLSCreds *tlscreds = NULL;
 303     const char *hostname = NULL;
 304     int ret = -EINVAL;
 305
 306     /* Pop the config into our state object. Exit if invalid. */
 307     saddr = nbd_config(s, options, &export, errp);
 308     if (!saddr) {
 309         goto error;
 310     }
 311
 312     tlscredsid = g_strdup(qdict_get_try_str(options, "tls-creds"));
 313     if (tlscredsid) {
 314         qdict_del(options, "tls-creds");
 315         tlscreds = nbd_get_tls_creds(tlscredsid, errp);
 316         if (!tlscreds) {
 317             goto error;
 318         }
 319
 320         if (saddr->type != SOCKET_ADDRESS_KIND_INET) {
 321             error_setg(errp, "TLS only supported over IP sockets");
 322             goto error;
 323         }
 324         hostname = saddr->u.inet->host;
 325     }
 326
 327     /* establish TCP connection, return error if it fails
 328      * TODO: Configurable retry-until-timeout behaviour.
 329      */
 330     sioc = nbd_establish_connection(saddr, errp);
 331     if (!sioc) {
 332         ret = -ECONNREFUSED;
 333         goto error;
 334     }
 335
 336     /* NBD handshake */
 337     ret = nbd_client_init(bs, sioc, export,
 338                           tlscreds, hostname, errp);
 339  error:
 340     if (sioc) {
 341         object_unref(OBJECT(sioc));
 342     }
 343     if (tlscreds) {
 344         object_unref(OBJECT(tlscreds));
 345     }
 346     qapi_free_SocketAddress(saddr);
 347     g_free(export);
 348     return ret;
 349 }
 350
 351 static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num,
 352                         int nb_sectors, QEMUIOVector *qiov)
 353 {
 354     return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov);
 355 }
 356
 357 static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num,
 358                          int nb_sectors, QEMUIOVector *qiov)
 359 {
 360     return nbd_client_co_writev(bs, sector_num, nb_sectors, qiov);
 361 }
 362
 363 static int nbd_co_flush(BlockDriverState *bs)
 364 {
 365     return nbd_client_co_flush(bs);
 366 }
 367
 368 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
 369 {
 370     bs->bl.max_discard = UINT32_MAX >> BDRV_SECTOR_BITS;
 371     bs->bl.max_transfer_length = UINT32_MAX >> BDRV_SECTOR_BITS;
 372 }
 373
 374 static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num,
 375                           int nb_sectors)
 376 {
 377     return nbd_client_co_discard(bs, sector_num, nb_sectors);
 378 }
 379
 380 static void nbd_close(BlockDriverState *bs)
 381 {
 382     nbd_client_close(bs);
 383 }
 384
 385 static int64_t nbd_getlength(BlockDriverState *bs)
 386 {
 387     BDRVNBDState *s = bs->opaque;
 388
 389     return s->client.size;
 390 }
 391
 392 static void nbd_detach_aio_context(BlockDriverState *bs)
 393 {
 394     nbd_client_detach_aio_context(bs);
 395 }
 396
 397 static void nbd_attach_aio_context(BlockDriverState *bs,
 398                                    AioContext *new_context)
 399 {
 400     nbd_client_attach_aio_context(bs, new_context);
 401 }
 402
 403 static void nbd_refresh_filename(BlockDriverState *bs, QDict *options)
 404 {
 405     QDict *opts = qdict_new();
 406     const char *path   = qdict_get_try_str(options, "path");
 407     const char *host   = qdict_get_try_str(options, "host");
 408     const char *port   = qdict_get_try_str(options, "port");
 409     const char *export = qdict_get_try_str(options, "export");
 410     const char *tlscreds = qdict_get_try_str(options, "tls-creds");
 411
 412     qdict_put_obj(opts, "driver", QOBJECT(qstring_from_str("nbd")));
 413
 414     if (path && export) {
 415         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 416                  "nbd+unix:///%s?socket=%s", export, path);
 417     } else if (path && !export) {
 418         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 419                  "nbd+unix://?socket=%s", path);
 420     } else if (!path && export && port) {
 421         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 422                  "nbd://%s:%s/%s", host, port, export);
 423     } else if (!path && export && !port) {
 424         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 425                  "nbd://%s/%s", host, export);
 426     } else if (!path && !export && port) {
 427         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 428                  "nbd://%s:%s", host, port);
 429     } else if (!path && !export && !port) {
 430         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 431                  "nbd://%s", host);
 432     }
 433
 434     if (path) {
 435         qdict_put_obj(opts, "path", QOBJECT(qstring_from_str(path)));
 436     } else if (port) {
 437         qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
 438         qdict_put_obj(opts, "port", QOBJECT(qstring_from_str(port)));
 439     } else {
 440         qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
 441     }
 442     if (export) {
 443         qdict_put_obj(opts, "export", QOBJECT(qstring_from_str(export)));
 444     }
 445     if (tlscreds) {
 446         qdict_put_obj(opts, "tls-creds", QOBJECT(qstring_from_str(tlscreds)));
 447     }
 448
 449     bs->full_open_options = opts;
 450 }
 451
 452 static BlockDriver bdrv_nbd = {
 453     .format_name                = "nbd",
 454     .protocol_name              = "nbd",
 455     .instance_size              = sizeof(BDRVNBDState),
 456     .bdrv_parse_filename        = nbd_parse_filename,
 457     .bdrv_file_open             = nbd_open,
 458     .bdrv_co_readv              = nbd_co_readv,
 459     .bdrv_co_writev             = nbd_co_writev,
 460     .bdrv_close                 = nbd_close,
 461     .bdrv_co_flush_to_os        = nbd_co_flush,
 462     .bdrv_co_discard            = nbd_co_discard,
 463     .bdrv_refresh_limits        = nbd_refresh_limits,
 464     .bdrv_getlength             = nbd_getlength,
 465     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 466     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 467     .bdrv_refresh_filename      = nbd_refresh_filename,
 468 };
 469
 470 static BlockDriver bdrv_nbd_tcp = {
 471     .format_name                = "nbd",
 472     .protocol_name              = "nbd+tcp",
 473     .instance_size              = sizeof(BDRVNBDState),
 474     .bdrv_parse_filename        = nbd_parse_filename,
 475     .bdrv_file_open             = nbd_open,
 476     .bdrv_co_readv              = nbd_co_readv,
 477     .bdrv_co_writev             = nbd_co_writev,
 478     .bdrv_close                 = nbd_close,
 479     .bdrv_co_flush_to_os        = nbd_co_flush,
 480     .bdrv_co_discard            = nbd_co_discard,
 481     .bdrv_refresh_limits        = nbd_refresh_limits,
 482     .bdrv_getlength             = nbd_getlength,
 483     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 484     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 485     .bdrv_refresh_filename      = nbd_refresh_filename,
 486 };
 487
 488 static BlockDriver bdrv_nbd_unix = {
 489     .format_name                = "nbd",
 490     .protocol_name              = "nbd+unix",
 491     .instance_size              = sizeof(BDRVNBDState),
 492     .bdrv_parse_filename        = nbd_parse_filename,
 493     .bdrv_file_open             = nbd_open,
 494     .bdrv_co_readv              = nbd_co_readv,
 495     .bdrv_co_writev             = nbd_co_writev,
 496     .bdrv_close                 = nbd_close,
 497     .bdrv_co_flush_to_os        = nbd_co_flush,
 498     .bdrv_co_discard            = nbd_co_discard,
 499     .bdrv_refresh_limits        = nbd_refresh_limits,
 500     .bdrv_getlength             = nbd_getlength,
 501     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 502     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 503     .bdrv_refresh_filename      = nbd_refresh_filename,
 504 };
 505
 506 static void bdrv_nbd_init(void)
 507 {
 508     bdrv_register(&bdrv_nbd);
 509     bdrv_register(&bdrv_nbd_tcp);
 510     bdrv_register(&bdrv_nbd_unix);
 511 }
 512
 513 block_init(bdrv_nbd_init);