nbd.h

Go to the documentation of this file.

/*
 * 1999 Copyright (C) Pavel Machek, [email protected]. This code is GPL.
 * 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)
 *            Made nbd_end_request() use the io_request_lock
 * 2001 Copyright (C) Steven Whitehouse
 *            New nbd_end_request() for compatibility with new linux block
 *            layer code.
 * 2003/06/24 Louis D. Langholtz <[email protected]>
 *            Removed unneeded blksize_bits field from nbd_device struct.
 *            Cleanup PARANOIA usage & code.
 * 2004/02/19 Paul Clements
 *            Removed PARANOIA, plus various cleanup and comments
 */

#ifndef _UAPILINUX_NBD_H
#define _UAPILINUX_NBD_H

#include <linux/types.h>

#define NBD_SET_SOCK    _IO( 0xab, 0 )
#define NBD_SET_BLKSIZE _IO( 0xab, 1 )
#define NBD_SET_SIZE    _IO( 0xab, 2 )
#define NBD_DO_IT   _IO( 0xab, 3 )
#define NBD_CLEAR_SOCK  _IO( 0xab, 4 )
#define NBD_CLEAR_QUE   _IO( 0xab, 5 )
#define NBD_PRINT_DEBUG _IO( 0xab, 6 )
#define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 )
#define NBD_DISCONNECT  _IO( 0xab, 8 )
#define NBD_SET_TIMEOUT _IO( 0xab, 9 )
#define NBD_SET_FLAGS   _IO( 0xab, 10)

enum {
    NBD_CMD_READ = 0,
    NBD_CMD_WRITE = 1,
    NBD_CMD_DISC = 2,
    /* there is a gap here to match userspace */
    NBD_CMD_TRIM = 4
};

/* values for flags field */
#define NBD_FLAG_HAS_FLAGS    (1 << 0) /* nbd-server supports flags */
#define NBD_FLAG_READ_ONLY    (1 << 1) /* device is read-only */
/* there is a gap here to match userspace */
#define NBD_FLAG_SEND_TRIM    (1 << 5) /* send trim/discard */

#define nbd_cmd(req) ((req)->cmd[0])

/* userspace doesn't need the nbd_device structure */

/* These are sent over the network in the request/reply magic fields */

#define NBD_REQUEST_MAGIC 0x25609513
#define NBD_REPLY_MAGIC 0x67446698
/* Do *not* use magics: 0x12560953 0x96744668. */

/*
 * This is the packet used for communication between client and
 * server. All data are in network byte order.
 */
struct nbd_request {
    __be32 magic;
    __be32 type;    /* == READ || == WRITE  */
    char handle[8];
    __be64 from;
    __be32 len;
} __attribute__((packed));

/*
 * This is the reply packet that nbd-server sends back to the client after
 * it has completed an I/O request (or an error occurs).
 */
struct nbd_reply {
    __be32 magic;
    __be32 error;       /* 0 = ok, else error   */
    char handle[8];     /* handle you got from request  */
};
#endif /* _UAPILINUX_NBD_H */