/*
   * 1999 Copyright (C) Pavel Machek, pavel@ucw.cz. 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 <ldl@aros.net>
   *            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,
  	NBD_CMD_FLUSH = 3,
  	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 */
  #define NBD_FLAG_SEND_FLUSH   (1 << 2) /* can flush writeback cache */
  /* 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 */