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

 /*
  *  Copyright (C) 2016 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;

 /* 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 */

 /* 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. */

 /* 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_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_SHUTDOWN    NBD_REP_ERR(7)  /* Server shutting down */

 /* 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 */

 /* 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

 ssize_t nbd_rwv(QIOChannel *ioc, struct iovec *iov, size_t niov, size_t length,
                 bool do_read, Error **errp);
 int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
                           QCryptoTLSCreds *tlscreds, const char *hostname,
                           QIOChannel **outioc,
                           off_t *size, Error **errp);
 int nbd_init(int fd, QIOChannelSocket *sioc, uint16_t flags, off_t size,
              Error **errp);
 ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *request);
 ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp);
 int nbd_client(int fd);
 int nbd_disconnect(int fd);

 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 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;

	/* 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 */

	/* 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. */

	/* 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_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_SHUTDOWN NBD_REP_ERR(7) /* Server shutting down */

	/* 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 */

	/* 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

	ssize_t nbd_rwv(QIOChannel ioc, struct iovec iov, size_t niov, size_t length,
	bool do_read, Error **errp);
	int nbd_receive_negotiate(QIOChannel ioc, const char name, uint16_t *flags,
	QCryptoTLSCreds tlscreds, const char hostname,
	QIOChannel **outioc,
	off_t size, Error *errp);
	int nbd_init(int fd, QIOChannelSocket *sioc, uint16_t flags, off_t size,
	Error **errp);
	ssize_t nbd_send_request(QIOChannel ioc, NBDRequest request);
	ssize_t nbd_receive_reply(QIOChannel ioc, NBDReply reply, Error **errp);
	int nbd_client(int fd);
	int nbd_disconnect(int fd);

	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