[qemu.git] / include / block / nbd.h

/*
 *  Copyright (C) 2016-2019 Red Hat, Inc.
 *  Copyright (C) 2005  Anthony Liguori <[email protected]>
 *
 *  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 "qapi/qapi-types-block.h"
#include "io/channel-socket.h"
#include "crypto/tlscreds.h"
#include "qapi/error.h"

/* 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;
    /* meta 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, meta 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)

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;

NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset,
                          uint64_t size, const char *name, const char *desc,
                          const char *bitmap, bool readonly, bool shared,
                          void (*close)(NBDExport *), bool writethrough,
                          BlockBackend *on_eject_blk, Error **errp);
void nbd_export_close(NBDExport *exp);
void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp);
void nbd_export_get(NBDExport *exp);
void nbd_export_put(NBDExport *exp);

BlockBackend *nbd_export_get_blockdev(NBDExport *exp);

AioContext *nbd_export_aio_context(NBDExport *exp);
NBDExport *nbd_export_find(const char *name);
void nbd_export_close_all(void);

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_start(SocketAddress *addr, const char *tls_creds,
                      const char *tls_authz, 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)
{
    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 -1;
    }

    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)        \
{                                                                       \
    if (nbd_read(ioc, val, sizeof(*val), desc, errp) < 0) {             \
        return -1;                                                      \
    }                                                                   \
    *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
Commit	Line	Data
75818250	1	/*
d21a2d34	2	* Copyright (C) 2016-2019 Red Hat, Inc.
7a5ca864 FB	3	* Copyright (C) 2005 Anthony Liguori <[email protected]>
	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
8167ee88	17	* along with this program; if not, see <http://www.gnu.org/licenses/>.
75818250	18	*/
7a5ca864 FB	19
	20	#ifndef NBD_H
	21	#define NBD_H
	22
9af23989	23	#include "qapi/qapi-types-block.h"
1c778ef7	24	#include "io/channel-socket.h"
f95910fe	25	#include "crypto/tlscreds.h"
e6798f06	26	#include "qapi/error.h"
c12504ce	27
c8a3a1b6 EB	28	/* Handshake phase structs - this struct is passed on the wire */
c8a3a1b6 EB	29
420a4e95	30	struct NBDOption {
c8a3a1b6 EB	31	uint64_t magic; /* NBD_OPTS_MAGIC */
	32	uint32_t option; /* NBD_OPT_* */
	33	uint32_t length;
	34	} QEMU_PACKED;
420a4e95	35	typedef struct NBDOption NBDOption;
c8a3a1b6	36
420a4e95	37	struct NBDOptionReply {
c8a3a1b6 EB	38	uint64_t magic; /* NBD_REP_MAGIC */
	39	uint32_t option; /* NBD_OPT_* */
	40	uint32_t type; /* NBD_REP_* */
	41	uint32_t length;
	42	} QEMU_PACKED;
420a4e95	43	typedef struct NBDOptionReply NBDOptionReply;
c8a3a1b6	44
25c14678 VSO	45	typedef struct NBDOptionReplyMetaContext {
	46	NBDOptionReply h; /* h.type = NBD_REP_META_CONTEXT, h.length > 4 */
	47	uint32_t context_id;
	48	/* meta context name follows */
	49	} QEMU_PACKED NBDOptionReplyMetaContext;
	50
c8a3a1b6 EB	51	/* Transmission phase structs
	52	*
	53	* Note: these are _NOT_ the same as the network representation of an NBD
56af2dda PB	54	* request and reply!
56af2dda PB	55	*/
ed2dd912	56	struct NBDRequest {
75818250 TS	57	uint64_t handle;
	58	uint64_t from;
	59	uint32_t len;
c8a3a1b6 EB	60	uint16_t flags; /* NBD_CMD_FLAG_* */
c8a3a1b6 EB	61	uint16_t type; /* NBD_CMD_* */
56af2dda	62	};
ed2dd912	63	typedef struct NBDRequest NBDRequest;
75818250	64
caad5384 VSO	65	typedef struct NBDSimpleReply {
	66	uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC */
	67	uint32_t error;
	68	uint64_t handle;
	69	} QEMU_PACKED NBDSimpleReply;
	70
bae245d1 EB	71	/* Header of all structured replies */
	72	typedef struct NBDStructuredReplyChunk {
	73	uint32_t magic; /* NBD_STRUCTURED_REPLY_MAGIC */
	74	uint16_t flags; /* combination of NBD_REPLY_FLAG_* */
	75	uint16_t type; /* NBD_REPLY_TYPE_* */
	76	uint64_t handle; /* request handle */
	77	uint32_t length; /* length of payload */
	78	} QEMU_PACKED NBDStructuredReplyChunk;
	79
d2febedb VSO	80	typedef union NBDReply {
	81	NBDSimpleReply simple;
	82	NBDStructuredReplyChunk structured;
	83	struct {
	84	/* @magic and @handle fields have the same offset and size both in
	85	* simple reply and structured reply chunk, so let them be accessible
	86	* without ".simple." or ".structured." specification
	87	*/
	88	uint32_t magic;
	89	uint32_t _skip;
	90	uint64_t handle;
	91	} QEMU_PACKED;
	92	} NBDReply;
	93
efdc0c10 EB	94	/* Header of chunk for NBD_REPLY_TYPE_OFFSET_DATA */
	95	typedef struct NBDStructuredReadData {
	96	NBDStructuredReplyChunk h; /* h.length >= 9 */
bae245d1	97	uint64_t offset;
efdc0c10 EB	98	/* At least one byte of data payload follows, calculated from h.length */
	99	} QEMU_PACKED NBDStructuredReadData;
	100
	101	/* Complete chunk for NBD_REPLY_TYPE_OFFSET_HOLE */
	102	typedef struct NBDStructuredReadHole {
	103	NBDStructuredReplyChunk h; /* h.length == 12 */
	104	uint64_t offset;
	105	uint32_t length;
	106	} QEMU_PACKED NBDStructuredReadHole;
bae245d1 EB	107
	108	/* Header of all NBD_REPLY_TYPE_ERROR* errors */
	109	typedef struct NBDStructuredError {
efdc0c10	110	NBDStructuredReplyChunk h; /* h.length >= 6 */
bae245d1 EB	111	uint32_t error;
	112	uint16_t message_length;
	113	} QEMU_PACKED NBDStructuredError;
	114
25c14678 VSO	115	/* Header of NBD_REPLY_TYPE_BLOCK_STATUS */
	116	typedef struct NBDStructuredMeta {
	117	NBDStructuredReplyChunk h; /* h.length >= 12 (at least one extent) */
	118	uint32_t context_id;
	119	/* extents follows */
	120	} QEMU_PACKED NBDStructuredMeta;
	121
	122	/* Extent chunk for NBD_REPLY_TYPE_BLOCK_STATUS */
	123	typedef struct NBDExtent {
	124	uint32_t length;
	125	uint32_t flags; /* NBD_STATE_* */
	126	} QEMU_PACKED NBDExtent;
	127
b626b51a EB	128	/* Transmission (export) flags: sent from server to client during handshake,
b626b51a EB	129	but describe what will happen during transmission */
c4e2aff8 HR	130	enum {
	131	NBD_FLAG_HAS_FLAGS_BIT = 0, /* Flags are there */
	132	NBD_FLAG_READ_ONLY_BIT = 1, /* Device is read-only */
	133	NBD_FLAG_SEND_FLUSH_BIT = 2, /* Send FLUSH */
	134	NBD_FLAG_SEND_FUA_BIT = 3, /* Send FUA (Force Unit Access) */
	135	NBD_FLAG_ROTATIONAL_BIT = 4, /* Use elevator algorithm -
	136	rotational media */
	137	NBD_FLAG_SEND_TRIM_BIT = 5, /* Send TRIM (discard) */
	138	NBD_FLAG_SEND_WRITE_ZEROES_BIT = 6, /* Send WRITE_ZEROES */
	139	NBD_FLAG_SEND_DF_BIT = 7, /* Send DF (Do not Fragment) */
	140	NBD_FLAG_CAN_MULTI_CONN_BIT = 8, /* Multi-client cache consistent */
	141	NBD_FLAG_SEND_RESIZE_BIT = 9, /* Send resize */
	142	NBD_FLAG_SEND_CACHE_BIT = 10, /* Send CACHE (prefetch) */
0a479545	143	NBD_FLAG_SEND_FAST_ZERO_BIT = 11, /* FAST_ZERO flag for WRITE_ZEROES */
c4e2aff8 HR	144	};
	145
	146	#define NBD_FLAG_HAS_FLAGS (1 << NBD_FLAG_HAS_FLAGS_BIT)
	147	#define NBD_FLAG_READ_ONLY (1 << NBD_FLAG_READ_ONLY_BIT)
	148	#define NBD_FLAG_SEND_FLUSH (1 << NBD_FLAG_SEND_FLUSH_BIT)
	149	#define NBD_FLAG_SEND_FUA (1 << NBD_FLAG_SEND_FUA_BIT)
	150	#define NBD_FLAG_ROTATIONAL (1 << NBD_FLAG_ROTATIONAL_BIT)
	151	#define NBD_FLAG_SEND_TRIM (1 << NBD_FLAG_SEND_TRIM_BIT)
	152	#define NBD_FLAG_SEND_WRITE_ZEROES (1 << NBD_FLAG_SEND_WRITE_ZEROES_BIT)
	153	#define NBD_FLAG_SEND_DF (1 << NBD_FLAG_SEND_DF_BIT)
	154	#define NBD_FLAG_CAN_MULTI_CONN (1 << NBD_FLAG_CAN_MULTI_CONN_BIT)
	155	#define NBD_FLAG_SEND_RESIZE (1 << NBD_FLAG_SEND_RESIZE_BIT)
	156	#define NBD_FLAG_SEND_CACHE (1 << NBD_FLAG_SEND_CACHE_BIT)
0a479545	157	#define NBD_FLAG_SEND_FAST_ZERO (1 << NBD_FLAG_SEND_FAST_ZERO_BIT)
bbb74edd	158
b626b51a EB	159	/* New-style handshake (global) flags, sent from server to client, and
b626b51a EB	160	control what will happen during handshake phase. */
c203c59a EB	161	#define NBD_FLAG_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
c203c59a EB	162	#define NBD_FLAG_NO_ZEROES (1 << 1) /* End handshake without zeroes. */
f5076b5a	163
b626b51a EB	164	/* New-style client flags, sent from client to server to control what happens
b626b51a EB	165	during handshake phase. */
c203c59a EB	166	#define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
c203c59a EB	167	#define NBD_FLAG_C_NO_ZEROES (1 << 1) /* End handshake without zeroes. */
f5076b5a	168
3736cc5b	169	/* Option requests. */
6bc86957 VSO	170	#define NBD_OPT_EXPORT_NAME (1)
	171	#define NBD_OPT_ABORT (2)
	172	#define NBD_OPT_LIST (3)
	173	/* #define NBD_OPT_PEEK_EXPORT (4) not in use */
	174	#define NBD_OPT_STARTTLS (5)
	175	#define NBD_OPT_INFO (6)
	176	#define NBD_OPT_GO (7)
	177	#define NBD_OPT_STRUCTURED_REPLY (8)
25c14678 VSO	178	#define NBD_OPT_LIST_META_CONTEXT (9)
25c14678 VSO	179	#define NBD_OPT_SET_META_CONTEXT (10)
3736cc5b EB	180
3736cc5b EB	181	/* Option reply types. */
b6f5d3b5 EB	182	#define NBD_REP_ERR(value) ((UINT32_C(1) << 31) \| (value))
b6f5d3b5 EB	183
6bc86957 VSO	184	#define NBD_REP_ACK (1) /* Data sending finished. */
	185	#define NBD_REP_SERVER (2) /* Export description. */
	186	#define NBD_REP_INFO (3) /* NBD_OPT_INFO/GO. */
25c14678	187	#define NBD_REP_META_CONTEXT (4) /* NBD_OPT_{LIST,SET}_META_CONTEXT */
3736cc5b EB	188
	189	#define NBD_REP_ERR_UNSUP NBD_REP_ERR(1) /* Unknown option */
	190	#define NBD_REP_ERR_POLICY NBD_REP_ERR(2) /* Server denied */
	191	#define NBD_REP_ERR_INVALID NBD_REP_ERR(3) /* Invalid length */
	192	#define NBD_REP_ERR_PLATFORM NBD_REP_ERR(4) /* Not compiled in */
	193	#define NBD_REP_ERR_TLS_REQD NBD_REP_ERR(5) /* TLS required */
	194	#define NBD_REP_ERR_UNKNOWN NBD_REP_ERR(6) /* Export unknown */
	195	#define NBD_REP_ERR_SHUTDOWN NBD_REP_ERR(7) /* Server shutting down */
	196	#define NBD_REP_ERR_BLOCK_SIZE_REQD NBD_REP_ERR(8) /* Need INFO_BLOCK_SIZE */
	197
	198	/* Info types, used during NBD_REP_INFO */
	199	#define NBD_INFO_EXPORT 0
	200	#define NBD_INFO_NAME 1
	201	#define NBD_INFO_DESCRIPTION 2
	202	#define NBD_INFO_BLOCK_SIZE 3
f95910fe	203
b626b51a	204	/* Request flags, sent from client to server during transmission phase */
1f4d6d18 EB	205	#define NBD_CMD_FLAG_FUA (1 << 0) /* 'force unit access' during write */
1f4d6d18 EB	206	#define NBD_CMD_FLAG_NO_HOLE (1 << 1) /* don't punch hole on zero run */
bae245d1	207	#define NBD_CMD_FLAG_DF (1 << 2) /* don't fragment structured read */
25c14678 VSO	208	#define NBD_CMD_FLAG_REQ_ONE (1 << 3) /* only one extent in BLOCK_STATUS
25c14678 VSO	209	* reply chunk */
0a479545	210	#define NBD_CMD_FLAG_FAST_ZERO (1 << 4) /* fail if WRITE_ZEROES is not fast */
f5076b5a	211
b626b51a	212	/* Supported request types */
75818250 TS	213	enum {
	214	NBD_CMD_READ = 0,
	215	NBD_CMD_WRITE = 1,
bbb74edd PB	216	NBD_CMD_DISC = 2,
bbb74edd PB	217	NBD_CMD_FLUSH = 3,
1f4d6d18	218	NBD_CMD_TRIM = 4,
bc37b06a	219	NBD_CMD_CACHE = 5,
1f4d6d18	220	NBD_CMD_WRITE_ZEROES = 6,
25c14678	221	NBD_CMD_BLOCK_STATUS = 7,
75818250 TS	222	};
75818250 TS	223
1d45f8b5 LV	224	#define NBD_DEFAULT_PORT 10809
1d45f8b5 LV	225
2d821488 SH	226	/* Maximum size of a single READ/WRITE data buffer */
2d821488 SH	227	#define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024)
476b923c	228
9d7ab222	229	/*
93676c88 EB	230	* Maximum size of a protocol string (export name, meta context name,
	231	* etc.). Use malloc rather than stack allocation for storage of a
	232	* string.
9d7ab222	233	*/
93676c88	234	#define NBD_MAX_STRING_SIZE 4096
3777b09f	235
bae245d1 EB	236	/* Two types of reply structures */
	237	#define NBD_SIMPLE_REPLY_MAGIC 0x67446698
	238	#define NBD_STRUCTURED_REPLY_MAGIC 0x668e33ef
	239
	240	/* Structured reply flags */
	241	#define NBD_REPLY_FLAG_DONE (1 << 0) /* This reply-chunk is last */
	242
	243	/* Structured reply types */
	244	#define NBD_REPLY_ERR(value) ((1 << 15) \| (value))
	245
	246	#define NBD_REPLY_TYPE_NONE 0
	247	#define NBD_REPLY_TYPE_OFFSET_DATA 1
	248	#define NBD_REPLY_TYPE_OFFSET_HOLE 2
25c14678	249	#define NBD_REPLY_TYPE_BLOCK_STATUS 5
bae245d1 EB	250	#define NBD_REPLY_TYPE_ERROR NBD_REPLY_ERR(1)
	251	#define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_ERR(2)
	252
3d068aff	253	/* Extent flags for base:allocation in NBD_REPLY_TYPE_BLOCK_STATUS */
25c14678 VSO	254	#define NBD_STATE_HOLE (1 << 0)
	255	#define NBD_STATE_ZERO (1 << 1)
	256
3d068aff VSO	257	/* Extent flags for qemu:dirty-bitmap in NBD_REPLY_TYPE_BLOCK_STATUS */
	258	#define NBD_STATE_DIRTY (1 << 0)
	259
f140e300 VSO	260	static inline bool nbd_reply_type_is_error(int type)
	261	{
	262	return type & (1 << 15);
	263	}
	264
dd689440 EB	265	/* NBD errors are based on errno numbers, so there is a 1:1 mapping,
	266	* but only a limited set of errno values is specified in the protocol.
	267	* Everything else is squashed to EINVAL.
	268	*/
	269	#define NBD_SUCCESS 0
	270	#define NBD_EPERM 1
	271	#define NBD_EIO 5
	272	#define NBD_ENOMEM 12
	273	#define NBD_EINVAL 22
	274	#define NBD_ENOSPC 28
bae245d1	275	#define NBD_EOVERFLOW 75
0a479545	276	#define NBD_ENOTSUP 95
dd689440 EB	277	#define NBD_ESHUTDOWN 108
dd689440 EB	278
004a89fc EB	279	/* Details collected by NBD_OPT_EXPORT_NAME and NBD_OPT_GO */
004a89fc EB	280	struct NBDExportInfo {
081dd1fe EB	281	/* Set by client before nbd_receive_negotiate() */
081dd1fe EB	282	bool request_sizes;
216ee365	283	char *x_dirty_bitmap;
d21a2d34 EB	284
	285	/* Set by client before nbd_receive_negotiate(), or by server results
	286	* during nbd_receive_export_list() */
6dc1667d	287	char name; / must be non-NULL */
f140e300 VSO	288
	289	/* In-out fields, set by client before nbd_receive_negotiate() and
	290	* updated by server results during nbd_receive_negotiate() */
	291	bool structured_reply;
78a33ab5	292	bool base_allocation; /* base:allocation context for NBD_CMD_BLOCK_STATUS */
f140e300	293
d21a2d34 EB	294	/* Set by server results during nbd_receive_negotiate() and
d21a2d34 EB	295	* nbd_receive_export_list() */
004a89fc EB	296	uint64_t size;
004a89fc EB	297	uint16_t flags;
081dd1fe EB	298	uint32_t min_block;
	299	uint32_t opt_block;
	300	uint32_t max_block;
78a33ab5	301
2df94eb5	302	uint32_t context_id;
d21a2d34 EB	303
	304	/* Set by server results during nbd_receive_export_list() */
	305	char *description;
0b576b6b EB	306	int n_contexts;
0b576b6b EB	307	char **contexts;
004a89fc EB	308	};
	309	typedef struct NBDExportInfo NBDExportInfo;
	310
a8e2bb6a VSO	311	int nbd_receive_negotiate(AioContext aio_context, QIOChannel ioc,
a8e2bb6a VSO	312	QCryptoTLSCreds *tlscreds,
6dc1667d EB	313	const char hostname, QIOChannel *outioc,
6dc1667d EB	314	NBDExportInfo info, Error *errp);
d21a2d34 EB	315	void nbd_free_export_list(NBDExportInfo *info, int count);
	316	int nbd_receive_export_list(QIOChannel ioc, QCryptoTLSCreds tlscreds,
	317	const char hostname, NBDExportInfo *info,
	318	Error **errp);
004a89fc	319	int nbd_init(int fd, QIOChannelSocket sioc, NBDExportInfo info,
be41c100	320	Error **errp);
490dc5ed	321	int nbd_send_request(QIOChannel ioc, NBDRequest request);
d3bd5b90 KW	322	int coroutine_fn nbd_receive_reply(BlockDriverState bs, QIOChannel ioc,
d3bd5b90 KW	323	NBDReply reply, Error *errp);
0a4eb864	324	int nbd_client(int fd);
7a5ca864	325	int nbd_disconnect(int fd);
dd689440	326	int nbd_errno_to_system_errno(int err);
7a5ca864	327
af49bbbe	328	typedef struct NBDExport NBDExport;
1743b515	329	typedef struct NBDClient NBDClient;
af49bbbe	330
9d26dfcb EB	331	NBDExport nbd_export_new(BlockDriverState bs, uint64_t dev_offset,
9d26dfcb EB	332	uint64_t size, const char name, const char desc,
dbb38caa	333	const char *bitmap, bool readonly, bool shared,
678ba275 EB	334	void (close)(NBDExport ), bool writethrough,
678ba275 EB	335	BlockBackend on_eject_blk, Error *errp);
af49bbbe	336	void nbd_export_close(NBDExport *exp);
a3b0dc75	337	void nbd_export_remove(NBDExport exp, NbdServerRemoveMode mode, Error *errp);
2c8d9f06 PB	338	void nbd_export_get(NBDExport *exp);
2c8d9f06 PB	339	void nbd_export_put(NBDExport *exp);
ce33967a	340
e140177d	341	BlockBackend nbd_export_get_blockdev(NBDExport exp);
125afda8	342
61bc846d	343	AioContext nbd_export_aio_context(NBDExport exp);
ee0a19ec	344	NBDExport nbd_export_find(const char name);
ee0a19ec PB	345	void nbd_export_close_all(void);
ee0a19ec PB	346
7f7dfe2a	347	void nbd_client_new(QIOChannelSocket *sioc,
f95910fe	348	QCryptoTLSCreds *tlscreds,
b25e12da	349	const char *tlsauthz,
0c9390d9	350	void (close_fn)(NBDClient , bool));
ce33967a PB	351	void nbd_client_get(NBDClient *client);
ce33967a PB	352	void nbd_client_put(NBDClient *client);
af49bbbe	353
bd269ebc	354	void nbd_server_start(SocketAddress addr, const char tls_creds,
00019455	355	const char tls_authz, Error *errp);
eed8b691	356	void nbd_server_start_options(NbdServerOptions arg, Error *errp);
bd269ebc	357
56dc682b EB	358	/* nbd_read
	359	* Reads @size bytes from @ioc. Returns 0 on success.
	360	*/
	361	static inline int nbd_read(QIOChannel ioc, void buffer, size_t size,
e6798f06	362	const char desc, Error *errp)
56dc682b	363	{
e6798f06 VSO	364	int ret = qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0;
	365
	366	if (ret < 0) {
	367	if (desc) {
	368	error_prepend(errp, "Failed to read %s: ", desc);
	369	}
	370	return -1;
	371	}
	372
	373	return 0;
	374	}
	375
	376	#define DEF_NBD_READ_N(bits) \
	377	static inline int nbd_read##bits(QIOChannel *ioc, \
	378	uint##bits##_t *val, \
	379	const char desc, Error *errp) \
	380	{ \
	381	if (nbd_read(ioc, val, sizeof(*val), desc, errp) < 0) { \
	382	return -1; \
	383	} \
	384	val = be##bits##_to_cpu(val); \
	385	return 0; \
56dc682b EB	386	}
56dc682b EB	387
e6798f06 VSO	388	DEF_NBD_READ_N(16) /* Defines nbd_read16(). */
	389	DEF_NBD_READ_N(32) /* Defines nbd_read32(). */
	390	DEF_NBD_READ_N(64) /* Defines nbd_read64(). */
	391
	392	#undef DEF_NBD_READ_N
	393
d2febedb VSO	394	static inline bool nbd_reply_is_simple(NBDReply *reply)
	395	{
	396	return reply->magic == NBD_SIMPLE_REPLY_MAGIC;
	397	}
	398
	399	static inline bool nbd_reply_is_structured(NBDReply *reply)
	400	{
	401	return reply->magic == NBD_STRUCTURED_REPLY_MAGIC;
	402	}
	403
f140e300	404	const char *nbd_reply_type_lookup(uint16_t type);
757a0d05 VSO	405	const char *nbd_opt_lookup(uint32_t opt);
	406	const char *nbd_rep_lookup(uint32_t rep);
	407	const char *nbd_info_lookup(uint16_t info);
	408	const char *nbd_cmd_lookup(uint16_t info);
	409	const char *nbd_err_lookup(int err);
f140e300	410
7a5ca864	411	#endif