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         saddr->type = SOCKET_ADDRESS_KIND_UNIX;
 208         saddr->u.q_unix = g_new0(UnixSocketAddress, 1);
 209         saddr->u.q_unix->path = g_strdup(qdict_get_str(options, "path"));
 210         qdict_del(options, "path");
 211     } else {
 212         saddr->type = SOCKET_ADDRESS_KIND_INET;
 213         saddr->u.inet = g_new0(InetSocketAddress, 1);
 214         saddr->u.inet->host = g_strdup(qdict_get_str(options, "host"));
 215         if (!qdict_get_try_str(options, "port")) {
 216             saddr->u.inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 217         } else {
 218             saddr->u.inet->port = g_strdup(qdict_get_str(options, "port"));
 219         }
 220         qdict_del(options, "host");
 221         qdict_del(options, "port");
 222     }
 223
 224     s->client.is_unix = saddr->type == SOCKET_ADDRESS_KIND_UNIX;
 225
 226     *export = g_strdup(qdict_get_try_str(options, "export"));
 227     if (*export) {
 228         qdict_del(options, "export");
 229     }
 230
 231     return saddr;
 232 }
 233
 234 NbdClientSession *nbd_get_client_session(BlockDriverState *bs)
 235 {
 236     BDRVNBDState *s = bs->opaque;
 237     return &s->client;
 238 }
 239
 240 static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr,
 241                                                   Error **errp)
 242 {
 243     QIOChannelSocket *sioc;
 244     Error *local_err = NULL;
 245
 246     sioc = qio_channel_socket_new();
 247
 248     qio_channel_socket_connect_sync(sioc,
 249                                     saddr,
 250                                     &local_err);
 251     if (local_err) {
 252         error_propagate(errp, local_err);
 253         return NULL;
 254     }
 255
 256     qio_channel_set_delay(QIO_CHANNEL(sioc), false);
 257
 258     return sioc;
 259 }
 260
 261
 262 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
 263 {
 264     Object *obj;
 265     QCryptoTLSCreds *creds;
 266
 267     obj = object_resolve_path_component(
 268         object_get_objects_root(), id);
 269     if (!obj) {
 270         error_setg(errp, "No TLS credentials with id '%s'",
 271                    id);
 272         return NULL;
 273     }
 274     creds = (QCryptoTLSCreds *)
 275         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
 276     if (!creds) {
 277         error_setg(errp, "Object with id '%s' is not TLS credentials",
 278                    id);
 279         return NULL;
 280     }
 281
 282     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
 283         error_setg(errp,
 284                    "Expecting TLS credentials with a client endpoint");
 285         return NULL;
 286     }
 287     object_ref(obj);
 288     return creds;
 289 }
 290
 291
 292 static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
 293                     Error **errp)
 294 {
 295     BDRVNBDState *s = bs->opaque;
 296     char *export = NULL;
 297     QIOChannelSocket *sioc = NULL;
 298     SocketAddress *saddr;
 299     const char *tlscredsid;
 300     QCryptoTLSCreds *tlscreds = NULL;
 301     const char *hostname = NULL;
 302     int ret = -EINVAL;
 303
 304     /* Pop the config into our state object. Exit if invalid. */
 305     saddr = nbd_config(s, options, &export, errp);
 306     if (!saddr) {
 307         goto error;
 308     }
 309
 310     tlscredsid = g_strdup(qdict_get_try_str(options, "tls-creds"));
 311     if (tlscredsid) {
 312         qdict_del(options, "tls-creds");
 313         tlscreds = nbd_get_tls_creds(tlscredsid, errp);
 314         if (!tlscreds) {
 315             goto error;
 316         }
 317
 318         if (saddr->type != SOCKET_ADDRESS_KIND_INET) {
 319             error_setg(errp, "TLS only supported over IP sockets");
 320             goto error;
 321         }
 322         hostname = saddr->u.inet->host;
 323     }
 324
 325     /* establish TCP connection, return error if it fails
 326      * TODO: Configurable retry-until-timeout behaviour.
 327      */
 328     sioc = nbd_establish_connection(saddr, errp);
 329     if (!sioc) {
 330         ret = -ECONNREFUSED;
 331         goto error;
 332     }
 333
 334     /* NBD handshake */
 335     ret = nbd_client_init(bs, sioc, export,
 336                           tlscreds, hostname, errp);
 337  error:
 338     if (sioc) {
 339         object_unref(OBJECT(sioc));
 340     }
 341     if (tlscreds) {
 342         object_unref(OBJECT(tlscreds));
 343     }
 344     qapi_free_SocketAddress(saddr);
 345     g_free(export);
 346     return ret;
 347 }
 348
 349 static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num,
 350                         int nb_sectors, QEMUIOVector *qiov)
 351 {
 352     return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov);
 353 }
 354
 355 static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num,
 356                          int nb_sectors, QEMUIOVector *qiov)
 357 {
 358     return nbd_client_co_writev(bs, sector_num, nb_sectors, qiov);
 359 }
 360
 361 static int nbd_co_flush(BlockDriverState *bs)
 362 {
 363     return nbd_client_co_flush(bs);
 364 }
 365
 366 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
 367 {
 368     bs->bl.max_discard = UINT32_MAX >> BDRV_SECTOR_BITS;
 369     bs->bl.max_transfer_length = UINT32_MAX >> BDRV_SECTOR_BITS;
 370 }
 371
 372 static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num,
 373                           int nb_sectors)
 374 {
 375     return nbd_client_co_discard(bs, sector_num, nb_sectors);
 376 }
 377
 378 static void nbd_close(BlockDriverState *bs)
 379 {
 380     nbd_client_close(bs);
 381 }
 382
 383 static int64_t nbd_getlength(BlockDriverState *bs)
 384 {
 385     BDRVNBDState *s = bs->opaque;
 386
 387     return s->client.size;
 388 }
 389
 390 static void nbd_detach_aio_context(BlockDriverState *bs)
 391 {
 392     nbd_client_detach_aio_context(bs);
 393 }
 394
 395 static void nbd_attach_aio_context(BlockDriverState *bs,
 396                                    AioContext *new_context)
 397 {
 398     nbd_client_attach_aio_context(bs, new_context);
 399 }
 400
 401 static void nbd_refresh_filename(BlockDriverState *bs, QDict *options)
 402 {
 403     QDict *opts = qdict_new();
 404     const char *path   = qdict_get_try_str(options, "path");
 405     const char *host   = qdict_get_try_str(options, "host");
 406     const char *port   = qdict_get_try_str(options, "port");
 407     const char *export = qdict_get_try_str(options, "export");
 408     const char *tlscreds = qdict_get_try_str(options, "tls-creds");
 409
 410     qdict_put_obj(opts, "driver", QOBJECT(qstring_from_str("nbd")));
 411
 412     if (path && export) {
 413         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 414                  "nbd+unix:///%s?socket=%s", export, path);
 415     } else if (path && !export) {
 416         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 417                  "nbd+unix://?socket=%s", path);
 418     } else if (!path && export && port) {
 419         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 420                  "nbd://%s:%s/%s", host, port, export);
 421     } else if (!path && export && !port) {
 422         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 423                  "nbd://%s/%s", host, export);
 424     } else if (!path && !export && port) {
 425         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 426                  "nbd://%s:%s", host, port);
 427     } else if (!path && !export && !port) {
 428         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 429                  "nbd://%s", host);
 430     }
 431
 432     if (path) {
 433         qdict_put_obj(opts, "path", QOBJECT(qstring_from_str(path)));
 434     } else if (port) {
 435         qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
 436         qdict_put_obj(opts, "port", QOBJECT(qstring_from_str(port)));
 437     } else {
 438         qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
 439     }
 440     if (export) {
 441         qdict_put_obj(opts, "export", QOBJECT(qstring_from_str(export)));
 442     }
 443     if (tlscreds) {
 444         qdict_put_obj(opts, "tls-creds", QOBJECT(qstring_from_str(tlscreds)));
 445     }
 446
 447     bs->full_open_options = opts;
 448 }
 449
 450 static BlockDriver bdrv_nbd = {
 451     .format_name                = "nbd",
 452     .protocol_name              = "nbd",
 453     .instance_size              = sizeof(BDRVNBDState),
 454     .bdrv_parse_filename        = nbd_parse_filename,
 455     .bdrv_file_open             = nbd_open,
 456     .bdrv_co_readv              = nbd_co_readv,
 457     .bdrv_co_writev             = nbd_co_writev,
 458     .bdrv_close                 = nbd_close,
 459     .bdrv_co_flush_to_os        = nbd_co_flush,
 460     .bdrv_co_discard            = nbd_co_discard,
 461     .bdrv_refresh_limits        = nbd_refresh_limits,
 462     .bdrv_getlength             = nbd_getlength,
 463     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 464     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 465     .bdrv_refresh_filename      = nbd_refresh_filename,
 466 };
 467
 468 static BlockDriver bdrv_nbd_tcp = {
 469     .format_name                = "nbd",
 470     .protocol_name              = "nbd+tcp",
 471     .instance_size              = sizeof(BDRVNBDState),
 472     .bdrv_parse_filename        = nbd_parse_filename,
 473     .bdrv_file_open             = nbd_open,
 474     .bdrv_co_readv              = nbd_co_readv,
 475     .bdrv_co_writev             = nbd_co_writev,
 476     .bdrv_close                 = nbd_close,
 477     .bdrv_co_flush_to_os        = nbd_co_flush,
 478     .bdrv_co_discard            = nbd_co_discard,
 479     .bdrv_refresh_limits        = nbd_refresh_limits,
 480     .bdrv_getlength             = nbd_getlength,
 481     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 482     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 483     .bdrv_refresh_filename      = nbd_refresh_filename,
 484 };
 485
 486 static BlockDriver bdrv_nbd_unix = {
 487     .format_name                = "nbd",
 488     .protocol_name              = "nbd+unix",
 489     .instance_size              = sizeof(BDRVNBDState),
 490     .bdrv_parse_filename        = nbd_parse_filename,
 491     .bdrv_file_open             = nbd_open,
 492     .bdrv_co_readv              = nbd_co_readv,
 493     .bdrv_co_writev             = nbd_co_writev,
 494     .bdrv_close                 = nbd_close,
 495     .bdrv_co_flush_to_os        = nbd_co_flush,
 496     .bdrv_co_discard            = nbd_co_discard,
 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 void bdrv_nbd_init(void)
 505 {
 506     bdrv_register(&bdrv_nbd);
 507     bdrv_register(&bdrv_nbd_tcp);
 508     bdrv_register(&bdrv_nbd_unix);
 509 }
 510
 511 block_init(bdrv_nbd_init);