include/block/nbd.h - qemu - Git at Google

 /*
  *  Copyright (C) 2016-2017 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 "qemu-common.h"
 #include "qemu/option.h"
 #include "io/channel-socket.h"
 #include "crypto/tlscreds.h"

 /* Handshake phase structs - this struct is passed on the wire */

 struct nbd_option {
     uint64_t magic; /* NBD_OPTS_MAGIC */
     uint32_t option; /* NBD_OPT_* */
     uint32_t length;
 } QEMU_PACKED;
 typedef struct nbd_option nbd_option;

 struct nbd_opt_reply {
     uint64_t magic; /* NBD_REP_MAGIC */
     uint32_t option; /* NBD_OPT_* */
     uint32_t type; /* NBD_REP_* */
     uint32_t length;
 } QEMU_PACKED;
 typedef struct nbd_opt_reply nbd_opt_reply;

 /* 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;

 struct NBDReply {
     uint64_t handle;
     uint32_t error;
 };
 typedef struct NBDReply NBDReply;

 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;

 /* Header of NBD_REPLY_TYPE_OFFSET_DATA, complete NBD_REPLY_TYPE_OFFSET_HOLE */
 typedef struct NBDStructuredRead {
     NBDStructuredReplyChunk h;
     uint64_t offset;
 } QEMU_PACKED NBDStructuredRead;

 /* Header of all NBD_REPLY_TYPE_ERROR* errors */
 typedef struct NBDStructuredError {
     NBDStructuredReplyChunk h;
     uint32_t error;
     uint16_t message_length;
 } QEMU_PACKED NBDStructuredError;

 /* 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)

 /* 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_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 */

 /* 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,
 };

 #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_ERROR         NBD_REPLY_ERR(1)
 #define NBD_REPLY_TYPE_ERROR_OFFSET  NBD_REPLY_ERR(2)

 /* 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;
     /* 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;
 };
 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_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);

 #endif
	/*
	* Copyright (C) 2016-2017 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 "qemu-common.h"
	#include "qemu/option.h"
	#include "io/channel-socket.h"
	#include "crypto/tlscreds.h"

	/* Handshake phase structs - this struct is passed on the wire */

	struct nbd_option {
	uint64_t magic; /* NBD_OPTS_MAGIC */
	uint32_t option; /* NBD_OPT_* */
	uint32_t length;
	} QEMU_PACKED;
	typedef struct nbd_option nbd_option;

	struct nbd_opt_reply {
	uint64_t magic; /* NBD_REP_MAGIC */
	uint32_t option; /* NBD_OPT_* */
	uint32_t type; /* NBD_REP_* */
	uint32_t length;
	} QEMU_PACKED;
	typedef struct nbd_opt_reply nbd_opt_reply;

	/* 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;

	struct NBDReply {
	uint64_t handle;
	uint32_t error;
	};
	typedef struct NBDReply NBDReply;

	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;

	/* Header of NBD_REPLY_TYPE_OFFSET_DATA, complete NBD_REPLY_TYPE_OFFSET_HOLE */
	typedef struct NBDStructuredRead {
	NBDStructuredReplyChunk h;
	uint64_t offset;
	} QEMU_PACKED NBDStructuredRead;

	/* Header of all NBD_REPLY_TYPE_ERROR* errors */
	typedef struct NBDStructuredError {
	NBDStructuredReplyChunk h;
	uint32_t error;
	uint16_t message_length;
	} QEMU_PACKED NBDStructuredError;

	/* 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)

	/* 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_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 */

	/* 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,
	};

	#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_ERROR NBD_REPLY_ERR(1)
	#define NBD_REPLY_TYPE_ERROR_OFFSET NBD_REPLY_ERR(2)

	/* 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;
	/* 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;
	};
	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_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);

	#endif