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

/*
 *  Copyright (C) 2016-2017 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"

/* 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 */
#define NBD_FLAG_HAS_FLAGS         (1 << 0) /* Flags are there */
#define NBD_FLAG_READ_ONLY         (1 << 1) /* Device is read-only */
#define NBD_FLAG_SEND_FLUSH        (1 << 2) /* Send FLUSH */
#define NBD_FLAG_SEND_FUA          (1 << 3) /* Send FUA (Force Unit Access) */
#define NBD_FLAG_ROTATIONAL        (1 << 4) /* Use elevator algorithm -
                                               rotational media */
#define NBD_FLAG_SEND_TRIM         (1 << 5) /* Send TRIM (discard) */
#define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* Send WRITE_ZEROES */
#define NBD_FLAG_SEND_DF           (1 << 7) /* Send DF (Do not Fragment) */

/* 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 */

/* Supported request types */
enum {
    NBD_CMD_READ = 0,
    NBD_CMD_WRITE = 1,
    NBD_CMD_DISC = 2,
    NBD_CMD_FLUSH = 3,
    NBD_CMD_TRIM = 4,
    /* 5 reserved for failed experiment NBD_CMD_CACHE */
    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 an export name. The NBD spec requires 256 and
 * suggests that servers support up to 4096, but we stick to only the
 * required size so that we can stack-allocate the names, and because
 * going larger would require an audit of more code to make sure we
 * aren't overflowing some other buffer. */
#define NBD_MAX_NAME_SIZE 256

/* 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)

/* Flags for extents (NBDExtent.flags) of NBD_REPLY_TYPE_BLOCK_STATUS,
 * for base:allocation meta context */
#define NBD_STATE_HOLE (1 << 0)
#define NBD_STATE_ZERO (1 << 1)

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_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;

    /* 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() */
    uint64_t size;
    uint16_t flags;
    uint32_t min_block;
    uint32_t opt_block;
    uint32_t max_block;

    uint32_t meta_base_allocation_id;
};
typedef struct NBDExportInfo NBDExportInfo;

int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
                          QCryptoTLSCreds *tlscreds, const char *hostname,
                          QIOChannel **outioc, NBDExportInfo *info,
                          Error **errp);
int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
             Error **errp);
int nbd_send_request(QIOChannel *ioc, NBDRequest *request);
int nbd_receive_reply(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, off_t dev_offset, off_t size,
                          uint16_t nbdflags, 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);

NBDExport *nbd_export_find(const char *name);
void nbd_export_set_name(NBDExport *exp, const char *name);
void nbd_export_set_description(NBDExport *exp, const char *description);
void nbd_export_close_all(void);

void nbd_client_new(NBDExport *exp,
                    QIOChannelSocket *sioc,
                    QCryptoTLSCreds *tlscreds,
                    const char *tlsaclname,
                    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,
                      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,
                           Error **errp)
{
    return qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0;
}

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);

#endif
Commit	Line	Data
75818250	1	/*
3736cc5b	2	* Copyright (C) 2016-2017 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"
c12504ce	26
c8a3a1b6 EB	27	/* Handshake phase structs - this struct is passed on the wire */
c8a3a1b6 EB	28
420a4e95	29	struct NBDOption {
c8a3a1b6 EB	30	uint64_t magic; /* NBD_OPTS_MAGIC */
	31	uint32_t option; /* NBD_OPT_* */
	32	uint32_t length;
	33	} QEMU_PACKED;
420a4e95	34	typedef struct NBDOption NBDOption;
c8a3a1b6	35
420a4e95	36	struct NBDOptionReply {
c8a3a1b6 EB	37	uint64_t magic; /* NBD_REP_MAGIC */
	38	uint32_t option; /* NBD_OPT_* */
	39	uint32_t type; /* NBD_REP_* */
	40	uint32_t length;
	41	} QEMU_PACKED;
420a4e95	42	typedef struct NBDOptionReply NBDOptionReply;
c8a3a1b6	43
25c14678 VSO	44	typedef struct NBDOptionReplyMetaContext {
	45	NBDOptionReply h; /* h.type = NBD_REP_META_CONTEXT, h.length > 4 */
	46	uint32_t context_id;
	47	/* meta context name follows */
	48	} QEMU_PACKED NBDOptionReplyMetaContext;
	49
c8a3a1b6 EB	50	/* Transmission phase structs
	51	*
	52	* Note: these are _NOT_ the same as the network representation of an NBD
56af2dda PB	53	* request and reply!
56af2dda PB	54	*/
ed2dd912	55	struct NBDRequest {
75818250 TS	56	uint64_t handle;
	57	uint64_t from;
	58	uint32_t len;
c8a3a1b6 EB	59	uint16_t flags; /* NBD_CMD_FLAG_* */
c8a3a1b6 EB	60	uint16_t type; /* NBD_CMD_* */
56af2dda	61	};
ed2dd912	62	typedef struct NBDRequest NBDRequest;
75818250	63
caad5384 VSO	64	typedef struct NBDSimpleReply {
	65	uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC */
	66	uint32_t error;
	67	uint64_t handle;
	68	} QEMU_PACKED NBDSimpleReply;
	69
bae245d1 EB	70	/* Header of all structured replies */
	71	typedef struct NBDStructuredReplyChunk {
	72	uint32_t magic; /* NBD_STRUCTURED_REPLY_MAGIC */
	73	uint16_t flags; /* combination of NBD_REPLY_FLAG_* */
	74	uint16_t type; /* NBD_REPLY_TYPE_* */
	75	uint64_t handle; /* request handle */
	76	uint32_t length; /* length of payload */
	77	} QEMU_PACKED NBDStructuredReplyChunk;
	78
d2febedb VSO	79	typedef union NBDReply {
	80	NBDSimpleReply simple;
	81	NBDStructuredReplyChunk structured;
	82	struct {
	83	/* @magic and @handle fields have the same offset and size both in
	84	* simple reply and structured reply chunk, so let them be accessible
	85	* without ".simple." or ".structured." specification
	86	*/
	87	uint32_t magic;
	88	uint32_t _skip;
	89	uint64_t handle;
	90	} QEMU_PACKED;
	91	} NBDReply;
	92
efdc0c10 EB	93	/* Header of chunk for NBD_REPLY_TYPE_OFFSET_DATA */
	94	typedef struct NBDStructuredReadData {
	95	NBDStructuredReplyChunk h; /* h.length >= 9 */
bae245d1	96	uint64_t offset;
efdc0c10 EB	97	/* At least one byte of data payload follows, calculated from h.length */
	98	} QEMU_PACKED NBDStructuredReadData;
	99
	100	/* Complete chunk for NBD_REPLY_TYPE_OFFSET_HOLE */
	101	typedef struct NBDStructuredReadHole {
	102	NBDStructuredReplyChunk h; /* h.length == 12 */
	103	uint64_t offset;
	104	uint32_t length;
	105	} QEMU_PACKED NBDStructuredReadHole;
bae245d1 EB	106
	107	/* Header of all NBD_REPLY_TYPE_ERROR* errors */
	108	typedef struct NBDStructuredError {
efdc0c10	109	NBDStructuredReplyChunk h; /* h.length >= 6 */
bae245d1 EB	110	uint32_t error;
	111	uint16_t message_length;
	112	} QEMU_PACKED NBDStructuredError;
	113
25c14678 VSO	114	/* Header of NBD_REPLY_TYPE_BLOCK_STATUS */
	115	typedef struct NBDStructuredMeta {
	116	NBDStructuredReplyChunk h; /* h.length >= 12 (at least one extent) */
	117	uint32_t context_id;
	118	/* extents follows */
	119	} QEMU_PACKED NBDStructuredMeta;
	120
	121	/* Extent chunk for NBD_REPLY_TYPE_BLOCK_STATUS */
	122	typedef struct NBDExtent {
	123	uint32_t length;
	124	uint32_t flags; /* NBD_STATE_* */
	125	} QEMU_PACKED NBDExtent;
	126
b626b51a EB	127	/* Transmission (export) flags: sent from server to client during handshake,
b626b51a EB	128	but describe what will happen during transmission */
92652b12 VSO	129	#define NBD_FLAG_HAS_FLAGS (1 << 0) /* Flags are there */
	130	#define NBD_FLAG_READ_ONLY (1 << 1) /* Device is read-only */
	131	#define NBD_FLAG_SEND_FLUSH (1 << 2) /* Send FLUSH */
	132	#define NBD_FLAG_SEND_FUA (1 << 3) /* Send FUA (Force Unit Access) */
	133	#define NBD_FLAG_ROTATIONAL (1 << 4) /* Use elevator algorithm -
	134	rotational media */
	135	#define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */
	136	#define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* Send WRITE_ZEROES */
bae245d1	137	#define NBD_FLAG_SEND_DF (1 << 7) /* Send DF (Do not Fragment) */
bbb74edd	138
b626b51a EB	139	/* New-style handshake (global) flags, sent from server to client, and
b626b51a EB	140	control what will happen during handshake phase. */
c203c59a EB	141	#define NBD_FLAG_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
c203c59a EB	142	#define NBD_FLAG_NO_ZEROES (1 << 1) /* End handshake without zeroes. */
f5076b5a	143
b626b51a EB	144	/* New-style client flags, sent from client to server to control what happens
b626b51a EB	145	during handshake phase. */
c203c59a EB	146	#define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
c203c59a EB	147	#define NBD_FLAG_C_NO_ZEROES (1 << 1) /* End handshake without zeroes. */
f5076b5a	148
3736cc5b	149	/* Option requests. */
6bc86957 VSO	150	#define NBD_OPT_EXPORT_NAME (1)
	151	#define NBD_OPT_ABORT (2)
	152	#define NBD_OPT_LIST (3)
	153	/* #define NBD_OPT_PEEK_EXPORT (4) not in use */
	154	#define NBD_OPT_STARTTLS (5)
	155	#define NBD_OPT_INFO (6)
	156	#define NBD_OPT_GO (7)
	157	#define NBD_OPT_STRUCTURED_REPLY (8)
25c14678 VSO	158	#define NBD_OPT_LIST_META_CONTEXT (9)
25c14678 VSO	159	#define NBD_OPT_SET_META_CONTEXT (10)
3736cc5b EB	160
3736cc5b EB	161	/* Option reply types. */
b6f5d3b5 EB	162	#define NBD_REP_ERR(value) ((UINT32_C(1) << 31) \| (value))
b6f5d3b5 EB	163
6bc86957 VSO	164	#define NBD_REP_ACK (1) /* Data sending finished. */
	165	#define NBD_REP_SERVER (2) /* Export description. */
	166	#define NBD_REP_INFO (3) /* NBD_OPT_INFO/GO. */
25c14678	167	#define NBD_REP_META_CONTEXT (4) /* NBD_OPT_{LIST,SET}_META_CONTEXT */
3736cc5b EB	168
	169	#define NBD_REP_ERR_UNSUP NBD_REP_ERR(1) /* Unknown option */
	170	#define NBD_REP_ERR_POLICY NBD_REP_ERR(2) /* Server denied */
	171	#define NBD_REP_ERR_INVALID NBD_REP_ERR(3) /* Invalid length */
	172	#define NBD_REP_ERR_PLATFORM NBD_REP_ERR(4) /* Not compiled in */
	173	#define NBD_REP_ERR_TLS_REQD NBD_REP_ERR(5) /* TLS required */
	174	#define NBD_REP_ERR_UNKNOWN NBD_REP_ERR(6) /* Export unknown */
	175	#define NBD_REP_ERR_SHUTDOWN NBD_REP_ERR(7) /* Server shutting down */
	176	#define NBD_REP_ERR_BLOCK_SIZE_REQD NBD_REP_ERR(8) /* Need INFO_BLOCK_SIZE */
	177
	178	/* Info types, used during NBD_REP_INFO */
	179	#define NBD_INFO_EXPORT 0
	180	#define NBD_INFO_NAME 1
	181	#define NBD_INFO_DESCRIPTION 2
	182	#define NBD_INFO_BLOCK_SIZE 3
f95910fe	183
b626b51a	184	/* Request flags, sent from client to server during transmission phase */
1f4d6d18 EB	185	#define NBD_CMD_FLAG_FUA (1 << 0) /* 'force unit access' during write */
1f4d6d18 EB	186	#define NBD_CMD_FLAG_NO_HOLE (1 << 1) /* don't punch hole on zero run */
bae245d1	187	#define NBD_CMD_FLAG_DF (1 << 2) /* don't fragment structured read */
25c14678 VSO	188	#define NBD_CMD_FLAG_REQ_ONE (1 << 3) /* only one extent in BLOCK_STATUS
25c14678 VSO	189	* reply chunk */
f5076b5a	190
b626b51a	191	/* Supported request types */
75818250 TS	192	enum {
	193	NBD_CMD_READ = 0,
	194	NBD_CMD_WRITE = 1,
bbb74edd PB	195	NBD_CMD_DISC = 2,
bbb74edd PB	196	NBD_CMD_FLUSH = 3,
1f4d6d18 EB	197	NBD_CMD_TRIM = 4,
	198	/* 5 reserved for failed experiment NBD_CMD_CACHE */
	199	NBD_CMD_WRITE_ZEROES = 6,
25c14678	200	NBD_CMD_BLOCK_STATUS = 7,
75818250 TS	201	};
75818250 TS	202
1d45f8b5 LV	203	#define NBD_DEFAULT_PORT 10809
1d45f8b5 LV	204
2d821488 SH	205	/* Maximum size of a single READ/WRITE data buffer */
2d821488 SH	206	#define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024)
476b923c	207
943cec86 EB	208	/* Maximum size of an export name. The NBD spec requires 256 and
	209	* suggests that servers support up to 4096, but we stick to only the
	210	* required size so that we can stack-allocate the names, and because
	211	* going larger would require an audit of more code to make sure we
	212	* aren't overflowing some other buffer. */
	213	#define NBD_MAX_NAME_SIZE 256
3777b09f	214
bae245d1 EB	215	/* Two types of reply structures */
	216	#define NBD_SIMPLE_REPLY_MAGIC 0x67446698
	217	#define NBD_STRUCTURED_REPLY_MAGIC 0x668e33ef
	218
	219	/* Structured reply flags */
	220	#define NBD_REPLY_FLAG_DONE (1 << 0) /* This reply-chunk is last */
	221
	222	/* Structured reply types */
	223	#define NBD_REPLY_ERR(value) ((1 << 15) \| (value))
	224
	225	#define NBD_REPLY_TYPE_NONE 0
	226	#define NBD_REPLY_TYPE_OFFSET_DATA 1
	227	#define NBD_REPLY_TYPE_OFFSET_HOLE 2
25c14678	228	#define NBD_REPLY_TYPE_BLOCK_STATUS 5
bae245d1 EB	229	#define NBD_REPLY_TYPE_ERROR NBD_REPLY_ERR(1)
	230	#define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_ERR(2)
	231
25c14678 VSO	232	/* Flags for extents (NBDExtent.flags) of NBD_REPLY_TYPE_BLOCK_STATUS,
	233	* for base:allocation meta context */
	234	#define NBD_STATE_HOLE (1 << 0)
	235	#define NBD_STATE_ZERO (1 << 1)
	236
f140e300 VSO	237	static inline bool nbd_reply_type_is_error(int type)
	238	{
	239	return type & (1 << 15);
	240	}
	241
dd689440 EB	242	/* NBD errors are based on errno numbers, so there is a 1:1 mapping,
	243	* but only a limited set of errno values is specified in the protocol.
	244	* Everything else is squashed to EINVAL.
	245	*/
	246	#define NBD_SUCCESS 0
	247	#define NBD_EPERM 1
	248	#define NBD_EIO 5
	249	#define NBD_ENOMEM 12
	250	#define NBD_EINVAL 22
	251	#define NBD_ENOSPC 28
bae245d1	252	#define NBD_EOVERFLOW 75
dd689440 EB	253	#define NBD_ESHUTDOWN 108
dd689440 EB	254
004a89fc EB	255	/* Details collected by NBD_OPT_EXPORT_NAME and NBD_OPT_GO */
004a89fc EB	256	struct NBDExportInfo {
081dd1fe EB	257	/* Set by client before nbd_receive_negotiate() */
081dd1fe EB	258	bool request_sizes;
f140e300 VSO	259
	260	/* In-out fields, set by client before nbd_receive_negotiate() and
	261	* updated by server results during nbd_receive_negotiate() */
	262	bool structured_reply;
78a33ab5	263	bool base_allocation; /* base:allocation context for NBD_CMD_BLOCK_STATUS */
f140e300	264
081dd1fe	265	/* Set by server results during nbd_receive_negotiate() */
004a89fc EB	266	uint64_t size;
004a89fc EB	267	uint16_t flags;
081dd1fe EB	268	uint32_t min_block;
	269	uint32_t opt_block;
	270	uint32_t max_block;
78a33ab5 VSO	271
78a33ab5 VSO	272	uint32_t meta_base_allocation_id;
004a89fc EB	273	};
	274	typedef struct NBDExportInfo NBDExportInfo;
	275
004a89fc	276	int nbd_receive_negotiate(QIOChannel ioc, const char name,
f95910fe	277	QCryptoTLSCreds tlscreds, const char hostname,
004a89fc EB	278	QIOChannel *outioc, NBDExportInfo info,
	279	Error **errp);
	280	int nbd_init(int fd, QIOChannelSocket sioc, NBDExportInfo info,
be41c100	281	Error **errp);
490dc5ed	282	int nbd_send_request(QIOChannel ioc, NBDRequest request);
ba845644	283	int nbd_receive_reply(QIOChannel ioc, NBDReply reply, Error **errp);
0a4eb864	284	int nbd_client(int fd);
7a5ca864	285	int nbd_disconnect(int fd);
dd689440	286	int nbd_errno_to_system_errno(int err);
7a5ca864	287
af49bbbe	288	typedef struct NBDExport NBDExport;
1743b515	289	typedef struct NBDClient NBDClient;
af49bbbe	290
cd7fca95	291	NBDExport nbd_export_new(BlockDriverState bs, off_t dev_offset, off_t size,
7423f417	292	uint16_t nbdflags, void (close)(NBDExport ),
cd7fca95	293	bool writethrough, BlockBackend *on_eject_blk,
98f44bbe	294	Error **errp);
af49bbbe	295	void nbd_export_close(NBDExport *exp);
a3b0dc75	296	void nbd_export_remove(NBDExport exp, NbdServerRemoveMode mode, Error *errp);
2c8d9f06 PB	297	void nbd_export_get(NBDExport *exp);
2c8d9f06 PB	298	void nbd_export_put(NBDExport *exp);
ce33967a	299
e140177d	300	BlockBackend nbd_export_get_blockdev(NBDExport exp);
125afda8	301
ee0a19ec PB	302	NBDExport nbd_export_find(const char name);
ee0a19ec PB	303	void nbd_export_set_name(NBDExport exp, const char name);
b1a75b33	304	void nbd_export_set_description(NBDExport exp, const char description);
ee0a19ec PB	305	void nbd_export_close_all(void);
ee0a19ec PB	306
1c778ef7 DB	307	void nbd_client_new(NBDExport *exp,
1c778ef7 DB	308	QIOChannelSocket *sioc,
f95910fe DB	309	QCryptoTLSCreds *tlscreds,
f95910fe DB	310	const char *tlsaclname,
0c9390d9	311	void (close_fn)(NBDClient , bool));
ce33967a PB	312	void nbd_client_get(NBDClient *client);
ce33967a PB	313	void nbd_client_put(NBDClient *client);
af49bbbe	314
bd269ebc MA	315	void nbd_server_start(SocketAddress addr, const char tls_creds,
	316	Error **errp);
	317
56dc682b EB	318
	319	/* nbd_read
	320	* Reads @size bytes from @ioc. Returns 0 on success.
	321	*/
	322	static inline int nbd_read(QIOChannel ioc, void buffer, size_t size,
	323	Error **errp)
	324	{
	325	return qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0;
	326	}
	327
d2febedb VSO	328	static inline bool nbd_reply_is_simple(NBDReply *reply)
	329	{
	330	return reply->magic == NBD_SIMPLE_REPLY_MAGIC;
	331	}
	332
	333	static inline bool nbd_reply_is_structured(NBDReply *reply)
	334	{
	335	return reply->magic == NBD_STRUCTURED_REPLY_MAGIC;
	336	}
	337
f140e300 VSO	338	const char *nbd_reply_type_lookup(uint16_t type);
f140e300 VSO	339
7a5ca864	340	#endif