[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"

/* 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) */
#define NBD_FLAG_CAN_MULTI_CONN    (1 << 8) /* Multi-client cache consistent */
#define NBD_FLAG_SEND_RESIZE       (1 << 9) /* Send resize */
#define NBD_FLAG_SEND_CACHE        (1 << 10) /* Send CACHE (prefetch) */

/* 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,
    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 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)

/* 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_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(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 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, uint64_t dev_offset,
                          uint64_t size, const char *name, const char *desc,
                          const char *bitmap, 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_close_all(void);

void nbd_client_new(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);
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"
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) */
df91328a DL	138	#define NBD_FLAG_CAN_MULTI_CONN (1 << 8) /* Multi-client cache consistent */
	139	#define NBD_FLAG_SEND_RESIZE (1 << 9) /* Send resize */
	140	#define NBD_FLAG_SEND_CACHE (1 << 10) /* Send CACHE (prefetch) */
bbb74edd	141
b626b51a EB	142	/* New-style handshake (global) flags, sent from server to client, and
b626b51a EB	143	control what will happen during handshake phase. */
c203c59a EB	144	#define NBD_FLAG_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
c203c59a EB	145	#define NBD_FLAG_NO_ZEROES (1 << 1) /* End handshake without zeroes. */
f5076b5a	146
b626b51a EB	147	/* New-style client flags, sent from client to server to control what happens
b626b51a EB	148	during handshake phase. */
c203c59a EB	149	#define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */
c203c59a EB	150	#define NBD_FLAG_C_NO_ZEROES (1 << 1) /* End handshake without zeroes. */
f5076b5a	151
3736cc5b	152	/* Option requests. */
6bc86957 VSO	153	#define NBD_OPT_EXPORT_NAME (1)
	154	#define NBD_OPT_ABORT (2)
	155	#define NBD_OPT_LIST (3)
	156	/* #define NBD_OPT_PEEK_EXPORT (4) not in use */
	157	#define NBD_OPT_STARTTLS (5)
	158	#define NBD_OPT_INFO (6)
	159	#define NBD_OPT_GO (7)
	160	#define NBD_OPT_STRUCTURED_REPLY (8)
25c14678 VSO	161	#define NBD_OPT_LIST_META_CONTEXT (9)
25c14678 VSO	162	#define NBD_OPT_SET_META_CONTEXT (10)
3736cc5b EB	163
3736cc5b EB	164	/* Option reply types. */
b6f5d3b5 EB	165	#define NBD_REP_ERR(value) ((UINT32_C(1) << 31) \| (value))
b6f5d3b5 EB	166
6bc86957 VSO	167	#define NBD_REP_ACK (1) /* Data sending finished. */
	168	#define NBD_REP_SERVER (2) /* Export description. */
	169	#define NBD_REP_INFO (3) /* NBD_OPT_INFO/GO. */
25c14678	170	#define NBD_REP_META_CONTEXT (4) /* NBD_OPT_{LIST,SET}_META_CONTEXT */
3736cc5b EB	171
	172	#define NBD_REP_ERR_UNSUP NBD_REP_ERR(1) /* Unknown option */
	173	#define NBD_REP_ERR_POLICY NBD_REP_ERR(2) /* Server denied */
	174	#define NBD_REP_ERR_INVALID NBD_REP_ERR(3) /* Invalid length */
	175	#define NBD_REP_ERR_PLATFORM NBD_REP_ERR(4) /* Not compiled in */
	176	#define NBD_REP_ERR_TLS_REQD NBD_REP_ERR(5) /* TLS required */
	177	#define NBD_REP_ERR_UNKNOWN NBD_REP_ERR(6) /* Export unknown */
	178	#define NBD_REP_ERR_SHUTDOWN NBD_REP_ERR(7) /* Server shutting down */
	179	#define NBD_REP_ERR_BLOCK_SIZE_REQD NBD_REP_ERR(8) /* Need INFO_BLOCK_SIZE */
	180
	181	/* Info types, used during NBD_REP_INFO */
	182	#define NBD_INFO_EXPORT 0
	183	#define NBD_INFO_NAME 1
	184	#define NBD_INFO_DESCRIPTION 2
	185	#define NBD_INFO_BLOCK_SIZE 3
f95910fe	186
b626b51a	187	/* Request flags, sent from client to server during transmission phase */
1f4d6d18 EB	188	#define NBD_CMD_FLAG_FUA (1 << 0) /* 'force unit access' during write */
1f4d6d18 EB	189	#define NBD_CMD_FLAG_NO_HOLE (1 << 1) /* don't punch hole on zero run */
bae245d1	190	#define NBD_CMD_FLAG_DF (1 << 2) /* don't fragment structured read */
25c14678 VSO	191	#define NBD_CMD_FLAG_REQ_ONE (1 << 3) /* only one extent in BLOCK_STATUS
25c14678 VSO	192	* reply chunk */
f5076b5a	193
b626b51a	194	/* Supported request types */
75818250 TS	195	enum {
	196	NBD_CMD_READ = 0,
	197	NBD_CMD_WRITE = 1,
bbb74edd PB	198	NBD_CMD_DISC = 2,
bbb74edd PB	199	NBD_CMD_FLUSH = 3,
1f4d6d18	200	NBD_CMD_TRIM = 4,
bc37b06a	201	NBD_CMD_CACHE = 5,
1f4d6d18	202	NBD_CMD_WRITE_ZEROES = 6,
25c14678	203	NBD_CMD_BLOCK_STATUS = 7,
75818250 TS	204	};
75818250 TS	205
1d45f8b5 LV	206	#define NBD_DEFAULT_PORT 10809
1d45f8b5 LV	207
2d821488 SH	208	/* Maximum size of a single READ/WRITE data buffer */
2d821488 SH	209	#define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024)
476b923c	210
943cec86 EB	211	/* Maximum size of an export name. The NBD spec requires 256 and
	212	* suggests that servers support up to 4096, but we stick to only the
	213	* required size so that we can stack-allocate the names, and because
	214	* going larger would require an audit of more code to make sure we
	215	* aren't overflowing some other buffer. */
	216	#define NBD_MAX_NAME_SIZE 256
3777b09f	217
bae245d1 EB	218	/* Two types of reply structures */
	219	#define NBD_SIMPLE_REPLY_MAGIC 0x67446698
	220	#define NBD_STRUCTURED_REPLY_MAGIC 0x668e33ef
	221
	222	/* Structured reply flags */
	223	#define NBD_REPLY_FLAG_DONE (1 << 0) /* This reply-chunk is last */
	224
	225	/* Structured reply types */
	226	#define NBD_REPLY_ERR(value) ((1 << 15) \| (value))
	227
	228	#define NBD_REPLY_TYPE_NONE 0
	229	#define NBD_REPLY_TYPE_OFFSET_DATA 1
	230	#define NBD_REPLY_TYPE_OFFSET_HOLE 2
25c14678	231	#define NBD_REPLY_TYPE_BLOCK_STATUS 5
bae245d1 EB	232	#define NBD_REPLY_TYPE_ERROR NBD_REPLY_ERR(1)
	233	#define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_ERR(2)
	234
3d068aff	235	/* Extent flags for base:allocation in NBD_REPLY_TYPE_BLOCK_STATUS */
25c14678 VSO	236	#define NBD_STATE_HOLE (1 << 0)
	237	#define NBD_STATE_ZERO (1 << 1)
	238
3d068aff VSO	239	/* Extent flags for qemu:dirty-bitmap in NBD_REPLY_TYPE_BLOCK_STATUS */
	240	#define NBD_STATE_DIRTY (1 << 0)
	241
f140e300 VSO	242	static inline bool nbd_reply_type_is_error(int type)
	243	{
	244	return type & (1 << 15);
	245	}
	246
dd689440 EB	247	/* NBD errors are based on errno numbers, so there is a 1:1 mapping,
	248	* but only a limited set of errno values is specified in the protocol.
	249	* Everything else is squashed to EINVAL.
	250	*/
	251	#define NBD_SUCCESS 0
	252	#define NBD_EPERM 1
	253	#define NBD_EIO 5
	254	#define NBD_ENOMEM 12
	255	#define NBD_EINVAL 22
	256	#define NBD_ENOSPC 28
bae245d1	257	#define NBD_EOVERFLOW 75
dd689440 EB	258	#define NBD_ESHUTDOWN 108
dd689440 EB	259
004a89fc EB	260	/* Details collected by NBD_OPT_EXPORT_NAME and NBD_OPT_GO */
004a89fc EB	261	struct NBDExportInfo {
081dd1fe EB	262	/* Set by client before nbd_receive_negotiate() */
081dd1fe EB	263	bool request_sizes;
216ee365	264	char *x_dirty_bitmap;
d21a2d34 EB	265
	266	/* Set by client before nbd_receive_negotiate(), or by server results
	267	* during nbd_receive_export_list() */
6dc1667d	268	char name; / must be non-NULL */
f140e300 VSO	269
	270	/* In-out fields, set by client before nbd_receive_negotiate() and
	271	* updated by server results during nbd_receive_negotiate() */
	272	bool structured_reply;
78a33ab5	273	bool base_allocation; /* base:allocation context for NBD_CMD_BLOCK_STATUS */
f140e300	274
d21a2d34 EB	275	/* Set by server results during nbd_receive_negotiate() and
d21a2d34 EB	276	* nbd_receive_export_list() */
004a89fc EB	277	uint64_t size;
004a89fc EB	278	uint16_t flags;
081dd1fe EB	279	uint32_t min_block;
	280	uint32_t opt_block;
	281	uint32_t max_block;
78a33ab5	282
2df94eb5	283	uint32_t context_id;
d21a2d34 EB	284
	285	/* Set by server results during nbd_receive_export_list() */
	286	char *description;
0b576b6b EB	287	int n_contexts;
0b576b6b EB	288	char **contexts;
004a89fc EB	289	};
	290	typedef struct NBDExportInfo NBDExportInfo;
	291
6dc1667d EB	292	int nbd_receive_negotiate(QIOChannel ioc, QCryptoTLSCreds tlscreds,
	293	const char hostname, QIOChannel *outioc,
	294	NBDExportInfo info, Error *errp);
d21a2d34 EB	295	void nbd_free_export_list(NBDExportInfo *info, int count);
	296	int nbd_receive_export_list(QIOChannel ioc, QCryptoTLSCreds tlscreds,
	297	const char hostname, NBDExportInfo *info,
	298	Error **errp);
004a89fc	299	int nbd_init(int fd, QIOChannelSocket sioc, NBDExportInfo info,
be41c100	300	Error **errp);
490dc5ed	301	int nbd_send_request(QIOChannel ioc, NBDRequest request);
ba845644	302	int nbd_receive_reply(QIOChannel ioc, NBDReply reply, Error **errp);
0a4eb864	303	int nbd_client(int fd);
7a5ca864	304	int nbd_disconnect(int fd);
dd689440	305	int nbd_errno_to_system_errno(int err);
7a5ca864	306
af49bbbe	307	typedef struct NBDExport NBDExport;
1743b515	308	typedef struct NBDClient NBDClient;
af49bbbe	309
9d26dfcb EB	310	NBDExport nbd_export_new(BlockDriverState bs, uint64_t dev_offset,
9d26dfcb EB	311	uint64_t size, const char name, const char desc,
678ba275 EB	312	const char *bitmap, uint16_t nbdflags,
	313	void (close)(NBDExport ), bool writethrough,
	314	BlockBackend on_eject_blk, Error *errp);
af49bbbe	315	void nbd_export_close(NBDExport *exp);
a3b0dc75	316	void nbd_export_remove(NBDExport exp, NbdServerRemoveMode mode, Error *errp);
2c8d9f06 PB	317	void nbd_export_get(NBDExport *exp);
2c8d9f06 PB	318	void nbd_export_put(NBDExport *exp);
ce33967a	319
e140177d	320	BlockBackend nbd_export_get_blockdev(NBDExport exp);
125afda8	321
ee0a19ec	322	NBDExport nbd_export_find(const char name);
ee0a19ec PB	323	void nbd_export_close_all(void);
ee0a19ec PB	324
7f7dfe2a	325	void nbd_client_new(QIOChannelSocket *sioc,
f95910fe DB	326	QCryptoTLSCreds *tlscreds,
f95910fe DB	327	const char *tlsaclname,
0c9390d9	328	void (close_fn)(NBDClient , bool));
ce33967a PB	329	void nbd_client_get(NBDClient *client);
ce33967a PB	330	void nbd_client_put(NBDClient *client);
af49bbbe	331
bd269ebc MA	332	void nbd_server_start(SocketAddress addr, const char tls_creds,
	333	Error **errp);
	334
56dc682b EB	335	/* nbd_read
	336	* Reads @size bytes from @ioc. Returns 0 on success.
	337	*/
	338	static inline int nbd_read(QIOChannel ioc, void buffer, size_t size,
	339	Error **errp)
	340	{
	341	return qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0;
	342	}
	343
d2febedb VSO	344	static inline bool nbd_reply_is_simple(NBDReply *reply)
	345	{
	346	return reply->magic == NBD_SIMPLE_REPLY_MAGIC;
	347	}
	348
	349	static inline bool nbd_reply_is_structured(NBDReply *reply)
	350	{
	351	return reply->magic == NBD_STRUCTURED_REPLY_MAGIC;
	352	}
	353
f140e300	354	const char *nbd_reply_type_lookup(uint16_t type);
757a0d05 VSO	355	const char *nbd_opt_lookup(uint32_t opt);
	356	const char *nbd_rep_lookup(uint32_t rep);
	357	const char *nbd_info_lookup(uint16_t info);
	358	const char *nbd_cmd_lookup(uint16_t info);
	359	const char *nbd_err_lookup(int err);
f140e300	360
7a5ca864	361	#endif