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 QemuOpts *socket_opts; 47 } BDRVNBDState; 48 49 static int nbd_parse_uri(const char *filename, QDict *options) 50 { 51 URI *uri; 52 const char *p; 53 QueryParams *qp = NULL; 54 int ret = 0; 55 bool is_unix; 56 57 uri = uri_parse(filename); 58 if (!uri) { 59 return -EINVAL; 60 } 61 62 /* transport */ 63 if (!strcmp(uri->scheme, "nbd")) { 64 is_unix = false; 65 } else if (!strcmp(uri->scheme, "nbd+tcp")) { 66 is_unix = false; 67 } else if (!strcmp(uri->scheme, "nbd+unix")) { 68 is_unix = true; 69 } else { 70 ret = -EINVAL; 71 goto out; 72 } 73 74 p = uri->path ? uri->path : "/"; 75 p += strspn(p, "/"); 76 if (p[0]) { 77 qdict_put(options, "export", qstring_from_str(p)); 78 } 79 80 qp = query_params_parse(uri->query); 81 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 82 ret = -EINVAL; 83 goto out; 84 } 85 86 if (is_unix) { 87 /* nbd+unix:///export?socket=path */ 88 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 89 ret = -EINVAL; 90 goto out; 91 } 92 qdict_put(options, "path", qstring_from_str(qp->p[0].value)); 93 } else { 94 QString *host; 95 /* nbd[+tcp]://host[:port]/export */ 96 if (!uri->server) { 97 ret = -EINVAL; 98 goto out; 99 } 100 101 /* strip braces from literal IPv6 address */ 102 if (uri->server[0] == '[') { 103 host = qstring_from_substr(uri->server, 1, 104 strlen(uri->server) - 2); 105 } else { 106 host = qstring_from_str(uri->server); 107 } 108 109 qdict_put(options, "host", host); 110 if (uri->port) { 111 char* port_str = g_strdup_printf("%d", uri->port); 112 qdict_put(options, "port", qstring_from_str(port_str)); 113 g_free(port_str); 114 } 115 } 116 117 out: 118 if (qp) { 119 query_params_free(qp); 120 } 121 uri_free(uri); 122 return ret; 123 } 124 125 static void nbd_parse_filename(const char *filename, QDict *options, 126 Error **errp) 127 { 128 char *file; 129 char *export_name; 130 const char *host_spec; 131 const char *unixpath; 132 133 if (qdict_haskey(options, "host") 134 || qdict_haskey(options, "port") 135 || qdict_haskey(options, "path")) 136 { 137 error_setg(errp, "host/port/path and a file name may not be specified " 138 "at the same time"); 139 return; 140 } 141 142 if (strstr(filename, "://")) { 143 int ret = nbd_parse_uri(filename, options); 144 if (ret < 0) { 145 error_setg(errp, "No valid URL specified"); 146 } 147 return; 148 } 149 150 file = g_strdup(filename); 151 152 export_name = strstr(file, EN_OPTSTR); 153 if (export_name) { 154 if (export_name[strlen(EN_OPTSTR)] == 0) { 155 goto out; 156 } 157 export_name[0] = 0; /* truncate 'file' */ 158 export_name += strlen(EN_OPTSTR); 159 160 qdict_put(options, "export", qstring_from_str(export_name)); 161 } 162 163 /* extract the host_spec - fail if it's not nbd:... */ 164 if (!strstart(file, "nbd:", &host_spec)) { 165 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 166 goto out; 167 } 168 169 if (!*host_spec) { 170 goto out; 171 } 172 173 /* are we a UNIX or TCP socket? */ 174 if (strstart(host_spec, "unix:", &unixpath)) { 175 qdict_put(options, "path", qstring_from_str(unixpath)); 176 } else { 177 InetSocketAddress *addr = NULL; 178 179 addr = inet_parse(host_spec, errp); 180 if (!addr) { 181 goto out; 182 } 183 184 qdict_put(options, "host", qstring_from_str(addr->host)); 185 qdict_put(options, "port", qstring_from_str(addr->port)); 186 qapi_free_InetSocketAddress(addr); 187 } 188 189 out: 190 g_free(file); 191 } 192 193 static void nbd_config(BDRVNBDState *s, QDict *options, char **export, 194 Error **errp) 195 { 196 Error *local_err = NULL; 197 198 if (qdict_haskey(options, "path") == qdict_haskey(options, "host")) { 199 if (qdict_haskey(options, "path")) { 200 error_setg(errp, "path and host may not be used at the same time."); 201 } else { 202 error_setg(errp, "one of path and host must be specified."); 203 } 204 return; 205 } 206 207 s->client.is_unix = qdict_haskey(options, "path"); 208 s->socket_opts = qemu_opts_create(&socket_optslist, NULL, 0, 209 &error_abort); 210 211 qemu_opts_absorb_qdict(s->socket_opts, options, &local_err); 212 if (local_err) { 213 error_propagate(errp, local_err); 214 return; 215 } 216 217 if (!qemu_opt_get(s->socket_opts, "port")) { 218 qemu_opt_set_number(s->socket_opts, "port", NBD_DEFAULT_PORT, 219 &error_abort); 220 } 221 222 *export = g_strdup(qdict_get_try_str(options, "export")); 223 if (*export) { 224 qdict_del(options, "export"); 225 } 226 } 227 228 NbdClientSession *nbd_get_client_session(BlockDriverState *bs) 229 { 230 BDRVNBDState *s = bs->opaque; 231 return &s->client; 232 } 233 234 static int nbd_establish_connection(BlockDriverState *bs, Error **errp) 235 { 236 BDRVNBDState *s = bs->opaque; 237 int sock; 238 239 if (s->client.is_unix) { 240 sock = unix_connect_opts(s->socket_opts, errp, NULL, NULL); 241 } else { 242 sock = inet_connect_opts(s->socket_opts, errp, NULL, NULL); 243 if (sock >= 0) { 244 socket_set_nodelay(sock); 245 } 246 } 247 248 /* Failed to establish connection */ 249 if (sock < 0) { 250 logout("Failed to establish connection to NBD server\n"); 251 return -errno; 252 } 253 254 return sock; 255 } 256 257 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 258 Error **errp) 259 { 260 BDRVNBDState *s = bs->opaque; 261 char *export = NULL; 262 int result, sock; 263 Error *local_err = NULL; 264 265 /* Pop the config into our state object. Exit if invalid. */ 266 nbd_config(s, options, &export, &local_err); 267 if (local_err) { 268 error_propagate(errp, local_err); 269 return -EINVAL; 270 } 271 272 /* establish TCP connection, return error if it fails 273 * TODO: Configurable retry-until-timeout behaviour. 274 */ 275 sock = nbd_establish_connection(bs, errp); 276 if (sock < 0) { 277 return sock; 278 } 279 280 /* NBD handshake */ 281 result = nbd_client_init(bs, sock, export, errp); 282 g_free(export); 283 return result; 284 } 285 286 static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num, 287 int nb_sectors, QEMUIOVector *qiov) 288 { 289 return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov); 290 } 291 292 static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num, 293 int nb_sectors, QEMUIOVector *qiov) 294 { 295 return nbd_client_co_writev(bs, sector_num, nb_sectors, qiov); 296 } 297 298 static int nbd_co_flush(BlockDriverState *bs) 299 { 300 return nbd_client_co_flush(bs); 301 } 302 303 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 304 { 305 bs->bl.max_discard = UINT32_MAX >> BDRV_SECTOR_BITS; 306 bs->bl.max_transfer_length = UINT32_MAX >> BDRV_SECTOR_BITS; 307 } 308 309 static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num, 310 int nb_sectors) 311 { 312 return nbd_client_co_discard(bs, sector_num, nb_sectors); 313 } 314 315 static void nbd_close(BlockDriverState *bs) 316 { 317 BDRVNBDState *s = bs->opaque; 318 319 qemu_opts_del(s->socket_opts); 320 nbd_client_close(bs); 321 } 322 323 static int64_t nbd_getlength(BlockDriverState *bs) 324 { 325 BDRVNBDState *s = bs->opaque; 326 327 return s->client.size; 328 } 329 330 static void nbd_detach_aio_context(BlockDriverState *bs) 331 { 332 nbd_client_detach_aio_context(bs); 333 } 334 335 static void nbd_attach_aio_context(BlockDriverState *bs, 336 AioContext *new_context) 337 { 338 nbd_client_attach_aio_context(bs, new_context); 339 } 340 341 static void nbd_refresh_filename(BlockDriverState *bs) 342 { 343 QDict *opts = qdict_new(); 344 const char *path = qdict_get_try_str(bs->options, "path"); 345 const char *host = qdict_get_try_str(bs->options, "host"); 346 const char *port = qdict_get_try_str(bs->options, "port"); 347 const char *export = qdict_get_try_str(bs->options, "export"); 348 349 qdict_put_obj(opts, "driver", QOBJECT(qstring_from_str("nbd"))); 350 351 if (path && export) { 352 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 353 "nbd+unix:///%s?socket=%s", export, path); 354 } else if (path && !export) { 355 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 356 "nbd+unix://?socket=%s", path); 357 } else if (!path && export && port) { 358 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 359 "nbd://%s:%s/%s", host, port, export); 360 } else if (!path && export && !port) { 361 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 362 "nbd://%s/%s", host, export); 363 } else if (!path && !export && port) { 364 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 365 "nbd://%s:%s", host, port); 366 } else if (!path && !export && !port) { 367 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 368 "nbd://%s", host); 369 } 370 371 if (path) { 372 qdict_put_obj(opts, "path", QOBJECT(qstring_from_str(path))); 373 } else if (port) { 374 qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host))); 375 qdict_put_obj(opts, "port", QOBJECT(qstring_from_str(port))); 376 } else { 377 qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host))); 378 } 379 if (export) { 380 qdict_put_obj(opts, "export", QOBJECT(qstring_from_str(export))); 381 } 382 383 bs->full_open_options = opts; 384 } 385 386 static BlockDriver bdrv_nbd = { 387 .format_name = "nbd", 388 .protocol_name = "nbd", 389 .instance_size = sizeof(BDRVNBDState), 390 .bdrv_parse_filename = nbd_parse_filename, 391 .bdrv_file_open = nbd_open, 392 .bdrv_co_readv = nbd_co_readv, 393 .bdrv_co_writev = nbd_co_writev, 394 .bdrv_close = nbd_close, 395 .bdrv_co_flush_to_os = nbd_co_flush, 396 .bdrv_co_discard = nbd_co_discard, 397 .bdrv_refresh_limits = nbd_refresh_limits, 398 .bdrv_getlength = nbd_getlength, 399 .bdrv_detach_aio_context = nbd_detach_aio_context, 400 .bdrv_attach_aio_context = nbd_attach_aio_context, 401 .bdrv_refresh_filename = nbd_refresh_filename, 402 }; 403 404 static BlockDriver bdrv_nbd_tcp = { 405 .format_name = "nbd", 406 .protocol_name = "nbd+tcp", 407 .instance_size = sizeof(BDRVNBDState), 408 .bdrv_parse_filename = nbd_parse_filename, 409 .bdrv_file_open = nbd_open, 410 .bdrv_co_readv = nbd_co_readv, 411 .bdrv_co_writev = nbd_co_writev, 412 .bdrv_close = nbd_close, 413 .bdrv_co_flush_to_os = nbd_co_flush, 414 .bdrv_co_discard = nbd_co_discard, 415 .bdrv_refresh_limits = nbd_refresh_limits, 416 .bdrv_getlength = nbd_getlength, 417 .bdrv_detach_aio_context = nbd_detach_aio_context, 418 .bdrv_attach_aio_context = nbd_attach_aio_context, 419 .bdrv_refresh_filename = nbd_refresh_filename, 420 }; 421 422 static BlockDriver bdrv_nbd_unix = { 423 .format_name = "nbd", 424 .protocol_name = "nbd+unix", 425 .instance_size = sizeof(BDRVNBDState), 426 .bdrv_parse_filename = nbd_parse_filename, 427 .bdrv_file_open = nbd_open, 428 .bdrv_co_readv = nbd_co_readv, 429 .bdrv_co_writev = nbd_co_writev, 430 .bdrv_close = nbd_close, 431 .bdrv_co_flush_to_os = nbd_co_flush, 432 .bdrv_co_discard = nbd_co_discard, 433 .bdrv_refresh_limits = nbd_refresh_limits, 434 .bdrv_getlength = nbd_getlength, 435 .bdrv_detach_aio_context = nbd_detach_aio_context, 436 .bdrv_attach_aio_context = nbd_attach_aio_context, 437 .bdrv_refresh_filename = nbd_refresh_filename, 438 }; 439 440 static void bdrv_nbd_init(void) 441 { 442 bdrv_register(&bdrv_nbd); 443 bdrv_register(&bdrv_nbd_tcp); 444 bdrv_register(&bdrv_nbd_unix); 445 } 446 447 block_init(bdrv_nbd_init); 448