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 "qemu/sockets.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
  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         saddr->type = SOCKET_ADDRESS_KIND_UNIX;
 209         saddr->u.q_unix = g_new0(UnixSocketAddress, 1);
 210         saddr->u.q_unix->path = g_strdup(qdict_get_str(options, "path"));
 211         qdict_del(options, "path");
 212     } else {
 213         saddr->type = SOCKET_ADDRESS_KIND_INET;
 214         saddr->u.inet = g_new0(InetSocketAddress, 1);
 215         saddr->u.inet->host = g_strdup(qdict_get_str(options, "host"));
 216         if (!qdict_get_try_str(options, "port")) {
 217             saddr->u.inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
 218         } else {
 219             saddr->u.inet->port = g_strdup(qdict_get_str(options, "port"));
 220         }
 221         qdict_del(options, "host");
 222         qdict_del(options, "port");
 223     }
 224
 225     s->client.is_unix = saddr->type == SOCKET_ADDRESS_KIND_UNIX;
 226
 227     *export = g_strdup(qdict_get_try_str(options, "export"));
 228     if (*export) {
 229         qdict_del(options, "export");
 230     }
 231
 232     return saddr;
 233 }
 234
 235 NbdClientSession *nbd_get_client_session(BlockDriverState *bs)
 236 {
 237     BDRVNBDState *s = bs->opaque;
 238     return &s->client;
 239 }
 240
 241 static int nbd_establish_connection(BlockDriverState *bs,
 242                                     SocketAddress *saddr,
 243                                     Error **errp)
 244 {
 245     BDRVNBDState *s = bs->opaque;
 246     int sock;
 247
 248     sock = socket_connect(saddr, errp, NULL, NULL);
 249
 250     if (sock < 0) {
 251         logout("Failed to establish connection to NBD server\n");
 252         return -EIO;
 253     }
 254
 255     if (!s->client.is_unix) {
 256         socket_set_nodelay(sock);
 257     }
 258
 259     return sock;
 260 }
 261
 262 static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
 263                     Error **errp)
 264 {
 265     BDRVNBDState *s = bs->opaque;
 266     char *export = NULL;
 267     int result, sock;
 268     SocketAddress *saddr;
 269
 270     /* Pop the config into our state object. Exit if invalid. */
 271     saddr = nbd_config(s, options, &export, errp);
 272     if (!saddr) {
 273         return -EINVAL;
 274     }
 275
 276     /* establish TCP connection, return error if it fails
 277      * TODO: Configurable retry-until-timeout behaviour.
 278      */
 279     sock = nbd_establish_connection(bs, saddr, errp);
 280     qapi_free_SocketAddress(saddr);
 281     if (sock < 0) {
 282         g_free(export);
 283         return sock;
 284     }
 285
 286     /* NBD handshake */
 287     result = nbd_client_init(bs, sock, export, errp);
 288     g_free(export);
 289     return result;
 290 }
 291
 292 static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num,
 293                         int nb_sectors, QEMUIOVector *qiov)
 294 {
 295     return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov);
 296 }
 297
 298 static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num,
 299                          int nb_sectors, QEMUIOVector *qiov)
 300 {
 301     return nbd_client_co_writev(bs, sector_num, nb_sectors, qiov);
 302 }
 303
 304 static int nbd_co_flush(BlockDriverState *bs)
 305 {
 306     return nbd_client_co_flush(bs);
 307 }
 308
 309 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
 310 {
 311     bs->bl.max_discard = UINT32_MAX >> BDRV_SECTOR_BITS;
 312     bs->bl.max_transfer_length = UINT32_MAX >> BDRV_SECTOR_BITS;
 313 }
 314
 315 static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num,
 316                           int nb_sectors)
 317 {
 318     return nbd_client_co_discard(bs, sector_num, nb_sectors);
 319 }
 320
 321 static void nbd_close(BlockDriverState *bs)
 322 {
 323     nbd_client_close(bs);
 324 }
 325
 326 static int64_t nbd_getlength(BlockDriverState *bs)
 327 {
 328     BDRVNBDState *s = bs->opaque;
 329
 330     return s->client.size;
 331 }
 332
 333 static void nbd_detach_aio_context(BlockDriverState *bs)
 334 {
 335     nbd_client_detach_aio_context(bs);
 336 }
 337
 338 static void nbd_attach_aio_context(BlockDriverState *bs,
 339                                    AioContext *new_context)
 340 {
 341     nbd_client_attach_aio_context(bs, new_context);
 342 }
 343
 344 static void nbd_refresh_filename(BlockDriverState *bs, QDict *options)
 345 {
 346     QDict *opts = qdict_new();
 347     const char *path   = qdict_get_try_str(options, "path");
 348     const char *host   = qdict_get_try_str(options, "host");
 349     const char *port   = qdict_get_try_str(options, "port");
 350     const char *export = qdict_get_try_str(options, "export");
 351
 352     qdict_put_obj(opts, "driver", QOBJECT(qstring_from_str("nbd")));
 353
 354     if (path && export) {
 355         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 356                  "nbd+unix:///%s?socket=%s", export, path);
 357     } else if (path && !export) {
 358         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 359                  "nbd+unix://?socket=%s", path);
 360     } else if (!path && export && port) {
 361         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 362                  "nbd://%s:%s/%s", host, port, export);
 363     } else if (!path && export && !port) {
 364         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 365                  "nbd://%s/%s", host, export);
 366     } else if (!path && !export && port) {
 367         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 368                  "nbd://%s:%s", host, port);
 369     } else if (!path && !export && !port) {
 370         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 371                  "nbd://%s", host);
 372     }
 373
 374     if (path) {
 375         qdict_put_obj(opts, "path", QOBJECT(qstring_from_str(path)));
 376     } else if (port) {
 377         qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
 378         qdict_put_obj(opts, "port", QOBJECT(qstring_from_str(port)));
 379     } else {
 380         qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
 381     }
 382     if (export) {
 383         qdict_put_obj(opts, "export", QOBJECT(qstring_from_str(export)));
 384     }
 385
 386     bs->full_open_options = opts;
 387 }
 388
 389 static BlockDriver bdrv_nbd = {
 390     .format_name                = "nbd",
 391     .protocol_name              = "nbd",
 392     .instance_size              = sizeof(BDRVNBDState),
 393     .bdrv_parse_filename        = nbd_parse_filename,
 394     .bdrv_file_open             = nbd_open,
 395     .bdrv_co_readv              = nbd_co_readv,
 396     .bdrv_co_writev             = nbd_co_writev,
 397     .bdrv_close                 = nbd_close,
 398     .bdrv_co_flush_to_os        = nbd_co_flush,
 399     .bdrv_co_discard            = nbd_co_discard,
 400     .bdrv_refresh_limits        = nbd_refresh_limits,
 401     .bdrv_getlength             = nbd_getlength,
 402     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 403     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 404     .bdrv_refresh_filename      = nbd_refresh_filename,
 405 };
 406
 407 static BlockDriver bdrv_nbd_tcp = {
 408     .format_name                = "nbd",
 409     .protocol_name              = "nbd+tcp",
 410     .instance_size              = sizeof(BDRVNBDState),
 411     .bdrv_parse_filename        = nbd_parse_filename,
 412     .bdrv_file_open             = nbd_open,
 413     .bdrv_co_readv              = nbd_co_readv,
 414     .bdrv_co_writev             = nbd_co_writev,
 415     .bdrv_close                 = nbd_close,
 416     .bdrv_co_flush_to_os        = nbd_co_flush,
 417     .bdrv_co_discard            = nbd_co_discard,
 418     .bdrv_refresh_limits        = nbd_refresh_limits,
 419     .bdrv_getlength             = nbd_getlength,
 420     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 421     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 422     .bdrv_refresh_filename      = nbd_refresh_filename,
 423 };
 424
 425 static BlockDriver bdrv_nbd_unix = {
 426     .format_name                = "nbd",
 427     .protocol_name              = "nbd+unix",
 428     .instance_size              = sizeof(BDRVNBDState),
 429     .bdrv_parse_filename        = nbd_parse_filename,
 430     .bdrv_file_open             = nbd_open,
 431     .bdrv_co_readv              = nbd_co_readv,
 432     .bdrv_co_writev             = nbd_co_writev,
 433     .bdrv_close                 = nbd_close,
 434     .bdrv_co_flush_to_os        = nbd_co_flush,
 435     .bdrv_co_discard            = nbd_co_discard,
 436     .bdrv_refresh_limits        = nbd_refresh_limits,
 437     .bdrv_getlength             = nbd_getlength,
 438     .bdrv_detach_aio_context    = nbd_detach_aio_context,
 439     .bdrv_attach_aio_context    = nbd_attach_aio_context,
 440     .bdrv_refresh_filename      = nbd_refresh_filename,
 441 };
 442
 443 static void bdrv_nbd_init(void)
 444 {
 445     bdrv_register(&bdrv_nbd);
 446     bdrv_register(&bdrv_nbd_tcp);
 447     bdrv_register(&bdrv_nbd_unix);
 448 }
 449
 450 block_init(bdrv_nbd_init);