| /* |
| * Copyright (C) 2016-2020 Red Hat, Inc. |
| * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws> |
| * |
| * Network Block Device |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; under version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #ifndef NBD_H |
| #define NBD_H |
| |
| #include "block/export.h" |
| #include "io/channel-socket.h" |
| #include "crypto/tlscreds.h" |
| #include "qapi/error.h" |
| |
| extern const BlockExportDriver blk_exp_nbd; |
| |
| /* Handshake phase structs - this struct is passed on the wire */ |
| |
| struct NBDOption { |
| uint64_t magic; /* NBD_OPTS_MAGIC */ |
| uint32_t option; /* NBD_OPT_* */ |
| uint32_t length; |
| } QEMU_PACKED; |
| typedef struct NBDOption NBDOption; |
| |
| struct NBDOptionReply { |
| uint64_t magic; /* NBD_REP_MAGIC */ |
| uint32_t option; /* NBD_OPT_* */ |
| uint32_t type; /* NBD_REP_* */ |
| uint32_t length; |
| } QEMU_PACKED; |
| typedef struct NBDOptionReply NBDOptionReply; |
| |
| typedef struct NBDOptionReplyMetaContext { |
| NBDOptionReply h; /* h.type = NBD_REP_META_CONTEXT, h.length > 4 */ |
| uint32_t context_id; |
| /* metadata context name follows */ |
| } QEMU_PACKED NBDOptionReplyMetaContext; |
| |
| /* Transmission phase structs |
| * |
| * Note: these are _NOT_ the same as the network representation of an NBD |
| * request and reply! |
| */ |
| struct NBDRequest { |
| uint64_t handle; |
| uint64_t from; |
| uint32_t len; |
| uint16_t flags; /* NBD_CMD_FLAG_* */ |
| uint16_t type; /* NBD_CMD_* */ |
| }; |
| typedef struct NBDRequest NBDRequest; |
| |
| typedef struct NBDSimpleReply { |
| uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC */ |
| uint32_t error; |
| uint64_t handle; |
| } QEMU_PACKED NBDSimpleReply; |
| |
| /* Header of all structured replies */ |
| typedef struct NBDStructuredReplyChunk { |
| uint32_t magic; /* NBD_STRUCTURED_REPLY_MAGIC */ |
| uint16_t flags; /* combination of NBD_REPLY_FLAG_* */ |
| uint16_t type; /* NBD_REPLY_TYPE_* */ |
| uint64_t handle; /* request handle */ |
| uint32_t length; /* length of payload */ |
| } QEMU_PACKED NBDStructuredReplyChunk; |
| |
| typedef union NBDReply { |
| NBDSimpleReply simple; |
| NBDStructuredReplyChunk structured; |
| struct { |
| /* @magic and @handle fields have the same offset and size both in |
| * simple reply and structured reply chunk, so let them be accessible |
| * without ".simple." or ".structured." specification |
| */ |
| uint32_t magic; |
| uint32_t _skip; |
| uint64_t handle; |
| } QEMU_PACKED; |
| } NBDReply; |
| |
| /* Header of chunk for NBD_REPLY_TYPE_OFFSET_DATA */ |
| typedef struct NBDStructuredReadData { |
| NBDStructuredReplyChunk h; /* h.length >= 9 */ |
| uint64_t offset; |
| /* At least one byte of data payload follows, calculated from h.length */ |
| } QEMU_PACKED NBDStructuredReadData; |
| |
| /* Complete chunk for NBD_REPLY_TYPE_OFFSET_HOLE */ |
| typedef struct NBDStructuredReadHole { |
| NBDStructuredReplyChunk h; /* h.length == 12 */ |
| uint64_t offset; |
| uint32_t length; |
| } QEMU_PACKED NBDStructuredReadHole; |
| |
| /* Header of all NBD_REPLY_TYPE_ERROR* errors */ |
| typedef struct NBDStructuredError { |
| NBDStructuredReplyChunk h; /* h.length >= 6 */ |
| uint32_t error; |
| uint16_t message_length; |
| } QEMU_PACKED NBDStructuredError; |
| |
| /* Header of NBD_REPLY_TYPE_BLOCK_STATUS */ |
| typedef struct NBDStructuredMeta { |
| NBDStructuredReplyChunk h; /* h.length >= 12 (at least one extent) */ |
| uint32_t context_id; |
| /* extents follows */ |
| } QEMU_PACKED NBDStructuredMeta; |
| |
| /* Extent chunk for NBD_REPLY_TYPE_BLOCK_STATUS */ |
| typedef struct NBDExtent { |
| uint32_t length; |
| uint32_t flags; /* NBD_STATE_* */ |
| } QEMU_PACKED NBDExtent; |
| |
| /* Transmission (export) flags: sent from server to client during handshake, |
| but describe what will happen during transmission */ |
| enum { |
| NBD_FLAG_HAS_FLAGS_BIT = 0, /* Flags are there */ |
| NBD_FLAG_READ_ONLY_BIT = 1, /* Device is read-only */ |
| NBD_FLAG_SEND_FLUSH_BIT = 2, /* Send FLUSH */ |
| NBD_FLAG_SEND_FUA_BIT = 3, /* Send FUA (Force Unit Access) */ |
| NBD_FLAG_ROTATIONAL_BIT = 4, /* Use elevator algorithm - |
| rotational media */ |
| NBD_FLAG_SEND_TRIM_BIT = 5, /* Send TRIM (discard) */ |
| NBD_FLAG_SEND_WRITE_ZEROES_BIT = 6, /* Send WRITE_ZEROES */ |
| NBD_FLAG_SEND_DF_BIT = 7, /* Send DF (Do not Fragment) */ |
| NBD_FLAG_CAN_MULTI_CONN_BIT = 8, /* Multi-client cache consistent */ |
| NBD_FLAG_SEND_RESIZE_BIT = 9, /* Send resize */ |
| NBD_FLAG_SEND_CACHE_BIT = 10, /* Send CACHE (prefetch) */ |
| NBD_FLAG_SEND_FAST_ZERO_BIT = 11, /* FAST_ZERO flag for WRITE_ZEROES */ |
| }; |
| |
| #define NBD_FLAG_HAS_FLAGS (1 << NBD_FLAG_HAS_FLAGS_BIT) |
| #define NBD_FLAG_READ_ONLY (1 << NBD_FLAG_READ_ONLY_BIT) |
| #define NBD_FLAG_SEND_FLUSH (1 << NBD_FLAG_SEND_FLUSH_BIT) |
| #define NBD_FLAG_SEND_FUA (1 << NBD_FLAG_SEND_FUA_BIT) |
| #define NBD_FLAG_ROTATIONAL (1 << NBD_FLAG_ROTATIONAL_BIT) |
| #define NBD_FLAG_SEND_TRIM (1 << NBD_FLAG_SEND_TRIM_BIT) |
| #define NBD_FLAG_SEND_WRITE_ZEROES (1 << NBD_FLAG_SEND_WRITE_ZEROES_BIT) |
| #define NBD_FLAG_SEND_DF (1 << NBD_FLAG_SEND_DF_BIT) |
| #define NBD_FLAG_CAN_MULTI_CONN (1 << NBD_FLAG_CAN_MULTI_CONN_BIT) |
| #define NBD_FLAG_SEND_RESIZE (1 << NBD_FLAG_SEND_RESIZE_BIT) |
| #define NBD_FLAG_SEND_CACHE (1 << NBD_FLAG_SEND_CACHE_BIT) |
| #define NBD_FLAG_SEND_FAST_ZERO (1 << NBD_FLAG_SEND_FAST_ZERO_BIT) |
| |
| /* New-style handshake (global) flags, sent from server to client, and |
| control what will happen during handshake phase. */ |
| #define NBD_FLAG_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */ |
| #define NBD_FLAG_NO_ZEROES (1 << 1) /* End handshake without zeroes. */ |
| |
| /* New-style client flags, sent from client to server to control what happens |
| during handshake phase. */ |
| #define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */ |
| #define NBD_FLAG_C_NO_ZEROES (1 << 1) /* End handshake without zeroes. */ |
| |
| /* Option requests. */ |
| #define NBD_OPT_EXPORT_NAME (1) |
| #define NBD_OPT_ABORT (2) |
| #define NBD_OPT_LIST (3) |
| /* #define NBD_OPT_PEEK_EXPORT (4) not in use */ |
| #define NBD_OPT_STARTTLS (5) |
| #define NBD_OPT_INFO (6) |
| #define NBD_OPT_GO (7) |
| #define NBD_OPT_STRUCTURED_REPLY (8) |
| #define NBD_OPT_LIST_META_CONTEXT (9) |
| #define NBD_OPT_SET_META_CONTEXT (10) |
| |
| /* Option reply types. */ |
| #define NBD_REP_ERR(value) ((UINT32_C(1) << 31) | (value)) |
| |
| #define NBD_REP_ACK (1) /* Data sending finished. */ |
| #define NBD_REP_SERVER (2) /* Export description. */ |
| #define NBD_REP_INFO (3) /* NBD_OPT_INFO/GO. */ |
| #define NBD_REP_META_CONTEXT (4) /* NBD_OPT_{LIST,SET}_META_CONTEXT */ |
| |
| #define NBD_REP_ERR_UNSUP NBD_REP_ERR(1) /* Unknown option */ |
| #define NBD_REP_ERR_POLICY NBD_REP_ERR(2) /* Server denied */ |
| #define NBD_REP_ERR_INVALID NBD_REP_ERR(3) /* Invalid length */ |
| #define NBD_REP_ERR_PLATFORM NBD_REP_ERR(4) /* Not compiled in */ |
| #define NBD_REP_ERR_TLS_REQD NBD_REP_ERR(5) /* TLS required */ |
| #define NBD_REP_ERR_UNKNOWN NBD_REP_ERR(6) /* Export unknown */ |
| #define NBD_REP_ERR_SHUTDOWN NBD_REP_ERR(7) /* Server shutting down */ |
| #define NBD_REP_ERR_BLOCK_SIZE_REQD NBD_REP_ERR(8) /* Need INFO_BLOCK_SIZE */ |
| |
| /* Info types, used during NBD_REP_INFO */ |
| #define NBD_INFO_EXPORT 0 |
| #define NBD_INFO_NAME 1 |
| #define NBD_INFO_DESCRIPTION 2 |
| #define NBD_INFO_BLOCK_SIZE 3 |
| |
| /* Request flags, sent from client to server during transmission phase */ |
| #define NBD_CMD_FLAG_FUA (1 << 0) /* 'force unit access' during write */ |
| #define NBD_CMD_FLAG_NO_HOLE (1 << 1) /* don't punch hole on zero run */ |
| #define NBD_CMD_FLAG_DF (1 << 2) /* don't fragment structured read */ |
| #define NBD_CMD_FLAG_REQ_ONE (1 << 3) /* only one extent in BLOCK_STATUS |
| * reply chunk */ |
| #define NBD_CMD_FLAG_FAST_ZERO (1 << 4) /* fail if WRITE_ZEROES is not fast */ |
| |
| /* Supported request types */ |
| enum { |
| NBD_CMD_READ = 0, |
| NBD_CMD_WRITE = 1, |
| NBD_CMD_DISC = 2, |
| NBD_CMD_FLUSH = 3, |
| NBD_CMD_TRIM = 4, |
| NBD_CMD_CACHE = 5, |
| NBD_CMD_WRITE_ZEROES = 6, |
| NBD_CMD_BLOCK_STATUS = 7, |
| }; |
| |
| #define NBD_DEFAULT_PORT 10809 |
| |
| /* Maximum size of a single READ/WRITE data buffer */ |
| #define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024) |
| |
| /* |
| * Maximum size of a protocol string (export name, metadata context name, |
| * etc.). Use malloc rather than stack allocation for storage of a |
| * string. |
| */ |
| #define NBD_MAX_STRING_SIZE 4096 |
| |
| /* Two types of reply structures */ |
| #define NBD_SIMPLE_REPLY_MAGIC 0x67446698 |
| #define NBD_STRUCTURED_REPLY_MAGIC 0x668e33ef |
| |
| /* Structured reply flags */ |
| #define NBD_REPLY_FLAG_DONE (1 << 0) /* This reply-chunk is last */ |
| |
| /* Structured reply types */ |
| #define NBD_REPLY_ERR(value) ((1 << 15) | (value)) |
| |
| #define NBD_REPLY_TYPE_NONE 0 |
| #define NBD_REPLY_TYPE_OFFSET_DATA 1 |
| #define NBD_REPLY_TYPE_OFFSET_HOLE 2 |
| #define NBD_REPLY_TYPE_BLOCK_STATUS 5 |
| #define NBD_REPLY_TYPE_ERROR NBD_REPLY_ERR(1) |
| #define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_ERR(2) |
| |
| /* Extent flags for base:allocation in NBD_REPLY_TYPE_BLOCK_STATUS */ |
| #define NBD_STATE_HOLE (1 << 0) |
| #define NBD_STATE_ZERO (1 << 1) |
| |
| /* Extent flags for qemu:dirty-bitmap in NBD_REPLY_TYPE_BLOCK_STATUS */ |
| #define NBD_STATE_DIRTY (1 << 0) |
| |
| /* No flags needed for qemu:allocation-depth in NBD_REPLY_TYPE_BLOCK_STATUS */ |
| |
| static inline bool nbd_reply_type_is_error(int type) |
| { |
| return type & (1 << 15); |
| } |
| |
| /* NBD errors are based on errno numbers, so there is a 1:1 mapping, |
| * but only a limited set of errno values is specified in the protocol. |
| * Everything else is squashed to EINVAL. |
| */ |
| #define NBD_SUCCESS 0 |
| #define NBD_EPERM 1 |
| #define NBD_EIO 5 |
| #define NBD_ENOMEM 12 |
| #define NBD_EINVAL 22 |
| #define NBD_ENOSPC 28 |
| #define NBD_EOVERFLOW 75 |
| #define NBD_ENOTSUP 95 |
| #define NBD_ESHUTDOWN 108 |
| |
| /* Details collected by NBD_OPT_EXPORT_NAME and NBD_OPT_GO */ |
| struct NBDExportInfo { |
| /* Set by client before nbd_receive_negotiate() */ |
| bool request_sizes; |
| char *x_dirty_bitmap; |
| |
| /* Set by client before nbd_receive_negotiate(), or by server results |
| * during nbd_receive_export_list() */ |
| char *name; /* must be non-NULL */ |
| |
| /* In-out fields, set by client before nbd_receive_negotiate() and |
| * updated by server results during nbd_receive_negotiate() */ |
| bool structured_reply; |
| bool base_allocation; /* base:allocation context for NBD_CMD_BLOCK_STATUS */ |
| |
| /* Set by server results during nbd_receive_negotiate() and |
| * nbd_receive_export_list() */ |
| uint64_t size; |
| uint16_t flags; |
| uint32_t min_block; |
| uint32_t opt_block; |
| uint32_t max_block; |
| |
| uint32_t context_id; |
| |
| /* Set by server results during nbd_receive_export_list() */ |
| char *description; |
| int n_contexts; |
| char **contexts; |
| }; |
| typedef struct NBDExportInfo NBDExportInfo; |
| |
| int nbd_receive_negotiate(AioContext *aio_context, QIOChannel *ioc, |
| QCryptoTLSCreds *tlscreds, |
| const char *hostname, QIOChannel **outioc, |
| NBDExportInfo *info, Error **errp); |
| void nbd_free_export_list(NBDExportInfo *info, int count); |
| int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, |
| const char *hostname, NBDExportInfo **info, |
| Error **errp); |
| int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info, |
| Error **errp); |
| int nbd_send_request(QIOChannel *ioc, NBDRequest *request); |
| int coroutine_fn nbd_receive_reply(BlockDriverState *bs, QIOChannel *ioc, |
| NBDReply *reply, Error **errp); |
| int nbd_client(int fd); |
| int nbd_disconnect(int fd); |
| int nbd_errno_to_system_errno(int err); |
| |
| typedef struct NBDExport NBDExport; |
| typedef struct NBDClient NBDClient; |
| |
| void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk); |
| |
| AioContext *nbd_export_aio_context(NBDExport *exp); |
| NBDExport *nbd_export_find(const char *name); |
| |
| void nbd_client_new(QIOChannelSocket *sioc, |
| QCryptoTLSCreds *tlscreds, |
| const char *tlsauthz, |
| void (*close_fn)(NBDClient *, bool)); |
| void nbd_client_get(NBDClient *client); |
| void nbd_client_put(NBDClient *client); |
| |
| void nbd_server_is_qemu_nbd(bool value); |
| bool nbd_server_is_running(void); |
| void nbd_server_start(SocketAddress *addr, const char *tls_creds, |
| const char *tls_authz, uint32_t max_connections, |
| Error **errp); |
| void nbd_server_start_options(NbdServerOptions *arg, Error **errp); |
| |
| /* nbd_read |
| * Reads @size bytes from @ioc. Returns 0 on success. |
| */ |
| static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size, |
| const char *desc, Error **errp) |
| { |
| ERRP_GUARD(); |
| int ret = qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0; |
| |
| if (ret < 0) { |
| if (desc) { |
| error_prepend(errp, "Failed to read %s: ", desc); |
| } |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| #define DEF_NBD_READ_N(bits) \ |
| static inline int nbd_read##bits(QIOChannel *ioc, \ |
| uint##bits##_t *val, \ |
| const char *desc, Error **errp) \ |
| { \ |
| int ret = nbd_read(ioc, val, sizeof(*val), desc, errp); \ |
| if (ret < 0) { \ |
| return ret; \ |
| } \ |
| *val = be##bits##_to_cpu(*val); \ |
| return 0; \ |
| } |
| |
| DEF_NBD_READ_N(16) /* Defines nbd_read16(). */ |
| DEF_NBD_READ_N(32) /* Defines nbd_read32(). */ |
| DEF_NBD_READ_N(64) /* Defines nbd_read64(). */ |
| |
| #undef DEF_NBD_READ_N |
| |
| static inline bool nbd_reply_is_simple(NBDReply *reply) |
| { |
| return reply->magic == NBD_SIMPLE_REPLY_MAGIC; |
| } |
| |
| static inline bool nbd_reply_is_structured(NBDReply *reply) |
| { |
| return reply->magic == NBD_STRUCTURED_REPLY_MAGIC; |
| } |
| |
| const char *nbd_reply_type_lookup(uint16_t type); |
| const char *nbd_opt_lookup(uint32_t opt); |
| const char *nbd_rep_lookup(uint32_t rep); |
| const char *nbd_info_lookup(uint16_t info); |
| const char *nbd_cmd_lookup(uint16_t info); |
| const char *nbd_err_lookup(int err); |
| |
| #endif |
