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