1/*
  2 * 1999 Copyright (C) Pavel Machek, pavel@ucw.cz. This code is GPL.
  3 * 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)
  4 *            Made nbd_end_request() use the io_request_lock
  5 * 2001 Copyright (C) Steven Whitehouse
  6 *            New nbd_end_request() for compatibility with new linux block
  7 *            layer code.
  8 * 2003/06/24 Louis D. Langholtz <ldl@aros.net>
  9 *            Removed unneeded blksize_bits field from nbd_device struct.
 10 *            Cleanup PARANOIA usage & code.
 11 * 2004/02/19 Paul Clements
 12 *            Removed PARANOIA, plus various cleanup and comments
 13 */
 14
 15#ifndef LINUX_NBD_H
 16#define LINUX_NBD_H
 17
 18#include <linux/types.h>
 19
 20#define NBD_SET_SOCK	_IO( 0xab, 0 )
 21#define NBD_SET_BLKSIZE	_IO( 0xab, 1 )
 22#define NBD_SET_SIZE	_IO( 0xab, 2 )
 23#define NBD_DO_IT	_IO( 0xab, 3 )
 24#define NBD_CLEAR_SOCK	_IO( 0xab, 4 )
 25#define NBD_CLEAR_QUE	_IO( 0xab, 5 )
 26#define NBD_PRINT_DEBUG	_IO( 0xab, 6 )
 27#define NBD_SET_SIZE_BLOCKS	_IO( 0xab, 7 )
 28#define NBD_DISCONNECT  _IO( 0xab, 8 )
 29#define NBD_SET_TIMEOUT _IO( 0xab, 9 )
 30
 31enum {
 32	NBD_CMD_READ = 0,
 33	NBD_CMD_WRITE = 1,
 34	NBD_CMD_DISC = 2
 35};
 36
 37#define nbd_cmd(req) ((req)->cmd[0])
 38
 39/* userspace doesn't need the nbd_device structure */
 40#ifdef __KERNEL__
 41
 42#include <linux/wait.h>
 43#include <linux/mutex.h>
 44
 45/* values for flags field */
 46#define NBD_READ_ONLY 0x0001
 47#define NBD_WRITE_NOCHK 0x0002
 48
 49struct request;
 50
 51struct nbd_device {
 52	int flags;
 53	int harderror;		/* Code of hard error			*/
 54	struct socket * sock;
 55	struct file * file; 	/* If == NULL, device is not ready, yet	*/
 56	int magic;
 57
 58	spinlock_t queue_lock;
 59	struct list_head queue_head;	/* Requests waiting result */
 60	struct request *active_req;
 61	wait_queue_head_t active_wq;
 62	struct list_head waiting_queue;	/* Requests to be sent */
 63	wait_queue_head_t waiting_wq;
 64
 65	struct mutex tx_lock;
 66	struct gendisk *disk;
 67	int blksize;
 68	u64 bytesize;
 69	pid_t pid; /* pid of nbd-client, if attached */
 70	int xmit_timeout;
 71};
 72
 73#endif
 74
 75/* These are sent over the network in the request/reply magic fields */
 76
 77#define NBD_REQUEST_MAGIC 0x25609513
 78#define NBD_REPLY_MAGIC 0x67446698
 79/* Do *not* use magics: 0x12560953 0x96744668. */
 80
 81/*
 82 * This is the packet used for communication between client and
 83 * server. All data are in network byte order.
 84 */
 85struct nbd_request {
 86	__be32 magic;
 87	__be32 type;	/* == READ || == WRITE 	*/
 88	char handle[8];
 89	__be64 from;
 90	__be32 len;
 91} __attribute__((packed));
 92
 93/*
 94 * This is the reply packet that nbd-server sends back to the client after
 95 * it has completed an I/O request (or an error occurs).
 96 */
 97struct nbd_reply {
 98	__be32 magic;
 99	__be32 error;		/* 0 = ok, else error	*/
100	char handle[8];		/* handle you got from request	*/
101};
102#endif