1 /* 2 * Copyright Red Hat 3 * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws> 4 * 5 * Network Block Device 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; under version 2 of the License. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #ifndef NBD_H 21 #define NBD_H 22 23 #include "block/export.h" 24 #include "io/channel-socket.h" 25 #include "crypto/tlscreds.h" 26 #include "qapi/error.h" 27 #include "qemu/bswap.h" 28 29 typedef struct NBDExport NBDExport; 30 typedef struct NBDClient NBDClient; 31 typedef struct NBDClientConnection NBDClientConnection; 32 typedef struct NBDMetaContexts NBDMetaContexts; 33 34 extern const BlockExportDriver blk_exp_nbd; 35 36 /* 37 * NBD_DEFAULT_HANDSHAKE_MAX_SECS: Number of seconds in which client must 38 * succeed at NBD_OPT_GO before being forcefully dropped as too slow. 39 */ 40 #define NBD_DEFAULT_HANDSHAKE_MAX_SECS 10 41 42 /* 43 * NBD_DEFAULT_MAX_CONNECTIONS: Number of client sockets to allow at 44 * once; must be large enough to allow a MULTI_CONN-aware client like 45 * nbdcopy to create its typical number of 8-16 sockets. 46 */ 47 #define NBD_DEFAULT_MAX_CONNECTIONS 100 48 49 /* Handshake phase structs - this struct is passed on the wire */ 50 51 typedef struct NBDOption { 52 uint64_t magic; /* NBD_OPTS_MAGIC */ 53 uint32_t option; /* NBD_OPT_* */ 54 uint32_t length; 55 } QEMU_PACKED NBDOption; 56 57 typedef struct NBDOptionReply { 58 uint64_t magic; /* NBD_REP_MAGIC */ 59 uint32_t option; /* NBD_OPT_* */ 60 uint32_t type; /* NBD_REP_* */ 61 uint32_t length; 62 } QEMU_PACKED NBDOptionReply; 63 64 typedef struct NBDOptionReplyMetaContext { 65 NBDOptionReply h; /* h.type = NBD_REP_META_CONTEXT, h.length > 4 */ 66 uint32_t context_id; 67 /* metadata context name follows */ 68 } QEMU_PACKED NBDOptionReplyMetaContext; 69 70 /* Track results of negotiation */ 71 typedef enum NBDMode { 72 /* Keep this list in a continuum of increasing features. */ 73 NBD_MODE_OLDSTYLE, /* server lacks newstyle negotiation */ 74 NBD_MODE_EXPORT_NAME, /* newstyle but only OPT_EXPORT_NAME safe */ 75 NBD_MODE_SIMPLE, /* newstyle but only simple replies */ 76 NBD_MODE_STRUCTURED, /* newstyle, structured replies enabled */ 77 NBD_MODE_EXTENDED, /* newstyle, extended headers enabled */ 78 } NBDMode; 79 80 /* Transmission phase structs */ 81 82 /* 83 * Note: NBDRequest is _NOT_ the same as the network representation of an NBD 84 * request! 85 */ 86 typedef struct NBDRequest { 87 uint64_t cookie; 88 uint64_t from; /* Offset touched by the command */ 89 uint64_t len; /* Effect length; 32 bit limit without extended headers */ 90 uint16_t flags; /* NBD_CMD_FLAG_* */ 91 uint16_t type; /* NBD_CMD_* */ 92 NBDMode mode; /* Determines which network representation to use */ 93 NBDMetaContexts *contexts; /* Used by NBD_CMD_BLOCK_STATUS */ 94 } NBDRequest; 95 96 typedef struct NBDSimpleReply { 97 uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC */ 98 uint32_t error; 99 uint64_t cookie; 100 } QEMU_PACKED NBDSimpleReply; 101 102 /* Header of all structured replies */ 103 typedef struct NBDStructuredReplyChunk { 104 uint32_t magic; /* NBD_STRUCTURED_REPLY_MAGIC */ 105 uint16_t flags; /* combination of NBD_REPLY_FLAG_* */ 106 uint16_t type; /* NBD_REPLY_TYPE_* */ 107 uint64_t cookie; /* request handle */ 108 uint32_t length; /* length of payload */ 109 } QEMU_PACKED NBDStructuredReplyChunk; 110 111 typedef struct NBDExtendedReplyChunk { 112 uint32_t magic; /* NBD_EXTENDED_REPLY_MAGIC */ 113 uint16_t flags; /* combination of NBD_REPLY_FLAG_* */ 114 uint16_t type; /* NBD_REPLY_TYPE_* */ 115 uint64_t cookie; /* request handle */ 116 uint64_t offset; /* request offset */ 117 uint64_t length; /* length of payload */ 118 } QEMU_PACKED NBDExtendedReplyChunk; 119 120 typedef union NBDReply { 121 NBDSimpleReply simple; 122 NBDStructuredReplyChunk structured; 123 NBDExtendedReplyChunk extended; 124 struct { 125 /* 126 * @magic and @cookie fields have the same offset and size in all 127 * forms of replies, so let them be accessible without ".simple.", 128 * ".structured.", or ".extended." specifications. 129 */ 130 uint32_t magic; 131 uint32_t _skip; 132 uint64_t cookie; 133 }; 134 } NBDReply; 135 QEMU_BUILD_BUG_ON(offsetof(NBDReply, simple.cookie) != 136 offsetof(NBDReply, cookie)); 137 QEMU_BUILD_BUG_ON(offsetof(NBDReply, structured.cookie) != 138 offsetof(NBDReply, cookie)); 139 QEMU_BUILD_BUG_ON(offsetof(NBDReply, extended.cookie) != 140 offsetof(NBDReply, cookie)); 141 142 /* Header of chunk for NBD_REPLY_TYPE_OFFSET_DATA */ 143 typedef struct NBDStructuredReadData { 144 /* header's .length >= 9 */ 145 uint64_t offset; 146 /* At least one byte of data payload follows, calculated from h.length */ 147 } QEMU_PACKED NBDStructuredReadData; 148 149 /* Complete chunk for NBD_REPLY_TYPE_OFFSET_HOLE */ 150 typedef struct NBDStructuredReadHole { 151 /* header's length == 12 */ 152 uint64_t offset; 153 uint32_t length; 154 } QEMU_PACKED NBDStructuredReadHole; 155 156 /* Header of all NBD_REPLY_TYPE_ERROR* errors */ 157 typedef struct NBDStructuredError { 158 /* header's length >= 6 */ 159 uint32_t error; 160 uint16_t message_length; 161 } QEMU_PACKED NBDStructuredError; 162 163 /* Header of NBD_REPLY_TYPE_BLOCK_STATUS */ 164 typedef struct NBDStructuredMeta { 165 /* header's length >= 12 (at least one extent) */ 166 uint32_t context_id; 167 /* NBDExtent32 extents[] follows, array length implied by header */ 168 } QEMU_PACKED NBDStructuredMeta; 169 170 /* Extent array element for NBD_REPLY_TYPE_BLOCK_STATUS */ 171 typedef struct NBDExtent32 { 172 uint32_t length; 173 uint32_t flags; /* NBD_STATE_* */ 174 } QEMU_PACKED NBDExtent32; 175 176 /* Header of NBD_REPLY_TYPE_BLOCK_STATUS_EXT */ 177 typedef struct NBDExtendedMeta { 178 /* header's length >= 24 (at least one extent) */ 179 uint32_t context_id; 180 uint32_t count; /* header length must be count * 16 + 8 */ 181 /* NBDExtent64 extents[count] follows */ 182 } QEMU_PACKED NBDExtendedMeta; 183 184 /* Extent array element for NBD_REPLY_TYPE_BLOCK_STATUS_EXT */ 185 typedef struct NBDExtent64 { 186 uint64_t length; 187 uint64_t flags; /* NBD_STATE_* */ 188 } QEMU_PACKED NBDExtent64; 189 190 /* Client payload for limiting NBD_CMD_BLOCK_STATUS reply */ 191 typedef struct NBDBlockStatusPayload { 192 uint64_t effect_length; 193 /* uint32_t ids[] follows, array length implied by header */ 194 } QEMU_PACKED NBDBlockStatusPayload; 195 196 /* Transmission (export) flags: sent from server to client during handshake, 197 but describe what will happen during transmission */ 198 enum { 199 NBD_FLAG_HAS_FLAGS_BIT = 0, /* Flags are there */ 200 NBD_FLAG_READ_ONLY_BIT = 1, /* Device is read-only */ 201 NBD_FLAG_SEND_FLUSH_BIT = 2, /* Send FLUSH */ 202 NBD_FLAG_SEND_FUA_BIT = 3, /* Send FUA (Force Unit Access) */ 203 NBD_FLAG_ROTATIONAL_BIT = 4, /* Use elevator algorithm - 204 rotational media */ 205 NBD_FLAG_SEND_TRIM_BIT = 5, /* Send TRIM (discard) */ 206 NBD_FLAG_SEND_WRITE_ZEROES_BIT = 6, /* Send WRITE_ZEROES */ 207 NBD_FLAG_SEND_DF_BIT = 7, /* Send DF (Do not Fragment) */ 208 NBD_FLAG_CAN_MULTI_CONN_BIT = 8, /* Multi-client cache consistent */ 209 NBD_FLAG_SEND_RESIZE_BIT = 9, /* Send resize */ 210 NBD_FLAG_SEND_CACHE_BIT = 10, /* Send CACHE (prefetch) */ 211 NBD_FLAG_SEND_FAST_ZERO_BIT = 11, /* FAST_ZERO flag for WRITE_ZEROES */ 212 NBD_FLAG_BLOCK_STAT_PAYLOAD_BIT = 12, /* PAYLOAD flag for BLOCK_STATUS */ 213 }; 214 215 #define NBD_FLAG_HAS_FLAGS (1 << NBD_FLAG_HAS_FLAGS_BIT) 216 #define NBD_FLAG_READ_ONLY (1 << NBD_FLAG_READ_ONLY_BIT) 217 #define NBD_FLAG_SEND_FLUSH (1 << NBD_FLAG_SEND_FLUSH_BIT) 218 #define NBD_FLAG_SEND_FUA (1 << NBD_FLAG_SEND_FUA_BIT) 219 #define NBD_FLAG_ROTATIONAL (1 << NBD_FLAG_ROTATIONAL_BIT) 220 #define NBD_FLAG_SEND_TRIM (1 << NBD_FLAG_SEND_TRIM_BIT) 221 #define NBD_FLAG_SEND_WRITE_ZEROES (1 << NBD_FLAG_SEND_WRITE_ZEROES_BIT) 222 #define NBD_FLAG_SEND_DF (1 << NBD_FLAG_SEND_DF_BIT) 223 #define NBD_FLAG_CAN_MULTI_CONN (1 << NBD_FLAG_CAN_MULTI_CONN_BIT) 224 #define NBD_FLAG_SEND_RESIZE (1 << NBD_FLAG_SEND_RESIZE_BIT) 225 #define NBD_FLAG_SEND_CACHE (1 << NBD_FLAG_SEND_CACHE_BIT) 226 #define NBD_FLAG_SEND_FAST_ZERO (1 << NBD_FLAG_SEND_FAST_ZERO_BIT) 227 #define NBD_FLAG_BLOCK_STAT_PAYLOAD (1 << NBD_FLAG_BLOCK_STAT_PAYLOAD_BIT) 228 229 /* New-style handshake (global) flags, sent from server to client, and 230 control what will happen during handshake phase. */ 231 #define NBD_FLAG_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */ 232 #define NBD_FLAG_NO_ZEROES (1 << 1) /* End handshake without zeroes. */ 233 234 /* New-style client flags, sent from client to server to control what happens 235 during handshake phase. */ 236 #define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */ 237 #define NBD_FLAG_C_NO_ZEROES (1 << 1) /* End handshake without zeroes. */ 238 239 /* Option requests. */ 240 #define NBD_OPT_EXPORT_NAME (1) 241 #define NBD_OPT_ABORT (2) 242 #define NBD_OPT_LIST (3) 243 /* #define NBD_OPT_PEEK_EXPORT (4) not in use */ 244 #define NBD_OPT_STARTTLS (5) 245 #define NBD_OPT_INFO (6) 246 #define NBD_OPT_GO (7) 247 #define NBD_OPT_STRUCTURED_REPLY (8) 248 #define NBD_OPT_LIST_META_CONTEXT (9) 249 #define NBD_OPT_SET_META_CONTEXT (10) 250 #define NBD_OPT_EXTENDED_HEADERS (11) 251 252 /* Option reply types. */ 253 #define NBD_REP_ERR(value) ((UINT32_C(1) << 31) | (value)) 254 255 #define NBD_REP_ACK (1) /* Data sending finished. */ 256 #define NBD_REP_SERVER (2) /* Export description. */ 257 #define NBD_REP_INFO (3) /* NBD_OPT_INFO/GO. */ 258 #define NBD_REP_META_CONTEXT (4) /* NBD_OPT_{LIST,SET}_META_CONTEXT */ 259 260 #define NBD_REP_ERR_UNSUP NBD_REP_ERR(1) /* Unknown option */ 261 #define NBD_REP_ERR_POLICY NBD_REP_ERR(2) /* Server denied */ 262 #define NBD_REP_ERR_INVALID NBD_REP_ERR(3) /* Invalid length */ 263 #define NBD_REP_ERR_PLATFORM NBD_REP_ERR(4) /* Not compiled in */ 264 #define NBD_REP_ERR_TLS_REQD NBD_REP_ERR(5) /* TLS required */ 265 #define NBD_REP_ERR_UNKNOWN NBD_REP_ERR(6) /* Export unknown */ 266 #define NBD_REP_ERR_SHUTDOWN NBD_REP_ERR(7) /* Server shutting down */ 267 #define NBD_REP_ERR_BLOCK_SIZE_REQD NBD_REP_ERR(8) /* Need INFO_BLOCK_SIZE */ 268 #define NBD_REP_ERR_TOO_BIG NBD_REP_ERR(9) /* Payload size overflow */ 269 #define NBD_REP_ERR_EXT_HEADER_REQD NBD_REP_ERR(10) /* Need extended headers */ 270 271 /* Info types, used during NBD_REP_INFO */ 272 #define NBD_INFO_EXPORT 0 273 #define NBD_INFO_NAME 1 274 #define NBD_INFO_DESCRIPTION 2 275 #define NBD_INFO_BLOCK_SIZE 3 276 277 /* Request flags, sent from client to server during transmission phase */ 278 #define NBD_CMD_FLAG_FUA (1 << 0) /* 'force unit access' during write */ 279 #define NBD_CMD_FLAG_NO_HOLE (1 << 1) /* don't punch hole on zero run */ 280 #define NBD_CMD_FLAG_DF (1 << 2) /* don't fragment structured read */ 281 #define NBD_CMD_FLAG_REQ_ONE (1 << 3) \ 282 /* only one extent in BLOCK_STATUS reply chunk */ 283 #define NBD_CMD_FLAG_FAST_ZERO (1 << 4) /* fail if WRITE_ZEROES is not fast */ 284 #define NBD_CMD_FLAG_PAYLOAD_LEN (1 << 5) \ 285 /* length describes payload, not effect; only with ext header */ 286 287 /* Supported request types */ 288 enum { 289 NBD_CMD_READ = 0, 290 NBD_CMD_WRITE = 1, 291 NBD_CMD_DISC = 2, 292 NBD_CMD_FLUSH = 3, 293 NBD_CMD_TRIM = 4, 294 NBD_CMD_CACHE = 5, 295 NBD_CMD_WRITE_ZEROES = 6, 296 NBD_CMD_BLOCK_STATUS = 7, 297 }; 298 299 #define NBD_DEFAULT_PORT 10809 300 301 /* Maximum size of a single READ/WRITE data buffer */ 302 #define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024) 303 304 /* 305 * Maximum size of a protocol string (export name, metadata context name, 306 * etc.). Use malloc rather than stack allocation for storage of a 307 * string. 308 */ 309 #define NBD_MAX_STRING_SIZE 4096 310 311 /* Two types of request structures, a given client will only use 1 */ 312 #define NBD_REQUEST_MAGIC 0x25609513 313 #define NBD_EXTENDED_REQUEST_MAGIC 0x21e41c71 314 315 /* 316 * Three types of reply structures, but what a client expects depends 317 * on NBD_OPT_STRUCTURED_REPLY and NBD_OPT_EXTENDED_HEADERS. 318 */ 319 #define NBD_SIMPLE_REPLY_MAGIC 0x67446698 320 #define NBD_STRUCTURED_REPLY_MAGIC 0x668e33ef 321 #define NBD_EXTENDED_REPLY_MAGIC 0x6e8a278c 322 323 /* Chunk reply flags (for structured and extended replies) */ 324 #define NBD_REPLY_FLAG_DONE (1 << 0) /* This reply-chunk is last */ 325 326 /* Chunk reply types */ 327 #define NBD_REPLY_ERR(value) ((1 << 15) | (value)) 328 329 #define NBD_REPLY_TYPE_NONE 0 330 #define NBD_REPLY_TYPE_OFFSET_DATA 1 331 #define NBD_REPLY_TYPE_OFFSET_HOLE 2 332 #define NBD_REPLY_TYPE_BLOCK_STATUS 5 333 #define NBD_REPLY_TYPE_BLOCK_STATUS_EXT 6 334 #define NBD_REPLY_TYPE_ERROR NBD_REPLY_ERR(1) 335 #define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_ERR(2) 336 337 /* Extent flags for base:allocation in NBD_REPLY_TYPE_BLOCK_STATUS */ 338 #define NBD_STATE_HOLE (1 << 0) 339 #define NBD_STATE_ZERO (1 << 1) 340 341 /* Extent flags for qemu:dirty-bitmap in NBD_REPLY_TYPE_BLOCK_STATUS */ 342 #define NBD_STATE_DIRTY (1 << 0) 343 344 /* No flags needed for qemu:allocation-depth in NBD_REPLY_TYPE_BLOCK_STATUS */ 345 nbd_reply_type_is_error(int type)346 static inline bool nbd_reply_type_is_error(int type) 347 { 348 return type & (1 << 15); 349 } 350 351 /* NBD errors are based on errno numbers, so there is a 1:1 mapping, 352 * but only a limited set of errno values is specified in the protocol. 353 * Everything else is squashed to EINVAL. 354 */ 355 #define NBD_SUCCESS 0 356 #define NBD_EPERM 1 357 #define NBD_EIO 5 358 #define NBD_ENOMEM 12 359 #define NBD_EINVAL 22 360 #define NBD_ENOSPC 28 361 #define NBD_EOVERFLOW 75 362 #define NBD_ENOTSUP 95 363 #define NBD_ESHUTDOWN 108 364 365 /* Details collected by NBD_OPT_EXPORT_NAME and NBD_OPT_GO */ 366 typedef struct NBDExportInfo { 367 /* Set by client before nbd_receive_negotiate() */ 368 bool request_sizes; 369 char *x_dirty_bitmap; 370 371 /* Set by client before nbd_receive_negotiate(), or by server results 372 * during nbd_receive_export_list() */ 373 char *name; /* must be non-NULL */ 374 375 /* In-out fields, set by client before nbd_receive_negotiate() and 376 * updated by server results during nbd_receive_negotiate() */ 377 NBDMode mode; /* input maximum mode tolerated; output actual mode chosen */ 378 bool base_allocation; /* base:allocation context for NBD_CMD_BLOCK_STATUS */ 379 380 /* Set by server results during nbd_receive_negotiate() and 381 * nbd_receive_export_list() */ 382 uint64_t size; 383 uint16_t flags; 384 uint32_t min_block; 385 uint32_t opt_block; 386 uint32_t max_block; 387 388 uint32_t context_id; 389 390 /* Set by server results during nbd_receive_export_list() */ 391 char *description; 392 int n_contexts; 393 char **contexts; 394 } NBDExportInfo; 395 396 int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 397 const char *hostname, QIOChannel **outioc, 398 NBDExportInfo *info, Error **errp); 399 void nbd_free_export_list(NBDExportInfo *info, int count); 400 int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 401 const char *hostname, NBDExportInfo **info, 402 Error **errp); 403 int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info, 404 Error **errp); 405 int nbd_send_request(QIOChannel *ioc, NBDRequest *request); 406 int coroutine_fn nbd_receive_reply(BlockDriverState *bs, QIOChannel *ioc, 407 NBDReply *reply, NBDMode mode, 408 Error **errp); 409 int nbd_client(int fd); 410 int nbd_disconnect(int fd); 411 int nbd_errno_to_system_errno(int err); 412 413 void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk); 414 415 AioContext *nbd_export_aio_context(NBDExport *exp); 416 NBDExport *nbd_export_find(const char *name); 417 418 void nbd_client_new(QIOChannelSocket *sioc, 419 uint32_t handshake_max_secs, 420 QCryptoTLSCreds *tlscreds, 421 const char *tlsauthz, 422 void (*close_fn)(NBDClient *, bool), 423 void *owner); 424 void *nbd_client_owner(NBDClient *client); 425 void nbd_client_get(NBDClient *client); 426 void nbd_client_put(NBDClient *client); 427 428 void nbd_server_is_qemu_nbd(int max_connections); 429 bool nbd_server_is_running(void); 430 int nbd_server_max_connections(void); 431 void nbd_server_start(SocketAddress *addr, const char *tls_creds, 432 const char *tls_authz, uint32_t max_connections, 433 Error **errp); 434 void nbd_server_start_options(NbdServerOptions *arg, Error **errp); 435 436 /* nbd_read 437 * Reads @size bytes from @ioc. Returns 0 on success. 438 */ nbd_read(QIOChannel * ioc,void * buffer,size_t size,const char * desc,Error ** errp)439 static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size, 440 const char *desc, Error **errp) 441 { 442 ERRP_GUARD(); 443 int ret = qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0; 444 445 if (ret < 0) { 446 if (desc) { 447 error_prepend(errp, "Failed to read %s: ", desc); 448 } 449 return ret; 450 } 451 452 return 0; 453 } 454 455 #define DEF_NBD_READ_N(bits) \ 456 static inline int nbd_read##bits(QIOChannel *ioc, \ 457 uint##bits##_t *val, \ 458 const char *desc, Error **errp) \ 459 { \ 460 int ret = nbd_read(ioc, val, sizeof(*val), desc, errp); \ 461 if (ret < 0) { \ 462 return ret; \ 463 } \ 464 *val = be##bits##_to_cpu(*val); \ 465 return 0; \ 466 } 467 468 DEF_NBD_READ_N(16) /* Defines nbd_read16(). */ 469 DEF_NBD_READ_N(32) /* Defines nbd_read32(). */ 470 DEF_NBD_READ_N(64) /* Defines nbd_read64(). */ 471 472 #undef DEF_NBD_READ_N 473 nbd_reply_is_simple(NBDReply * reply)474 static inline bool nbd_reply_is_simple(NBDReply *reply) 475 { 476 return reply->magic == NBD_SIMPLE_REPLY_MAGIC; 477 } 478 nbd_reply_is_structured(NBDReply * reply)479 static inline bool nbd_reply_is_structured(NBDReply *reply) 480 { 481 return reply->magic == NBD_STRUCTURED_REPLY_MAGIC; 482 } 483 484 const char *nbd_reply_type_lookup(uint16_t type); 485 const char *nbd_opt_lookup(uint32_t opt); 486 const char *nbd_rep_lookup(uint32_t rep); 487 const char *nbd_info_lookup(uint16_t info); 488 const char *nbd_cmd_lookup(uint16_t info); 489 const char *nbd_err_lookup(int err); 490 const char *nbd_mode_lookup(NBDMode mode); 491 492 /* nbd/client-connection.c */ 493 void nbd_client_connection_enable_retry(NBDClientConnection *conn); 494 495 NBDClientConnection *nbd_client_connection_new(const SocketAddress *saddr, 496 bool do_negotiation, 497 const char *export_name, 498 const char *x_dirty_bitmap, 499 QCryptoTLSCreds *tlscreds, 500 const char *tlshostname); 501 void nbd_client_connection_release(NBDClientConnection *conn); 502 503 QIOChannel *coroutine_fn 504 nbd_co_establish_connection(NBDClientConnection *conn, NBDExportInfo *info, 505 bool blocking, Error **errp); 506 507 void nbd_co_establish_connection_cancel(NBDClientConnection *conn); 508 509 #endif 510