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 _UAPILINUX_NBD_H
16 #define _UAPILINUX_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 #define NBD_SET_FLAGS   _IO( 0xab, 10)
31 
32 enum {
33 	NBD_CMD_READ = 0,
34 	NBD_CMD_WRITE = 1,
35 	NBD_CMD_DISC = 2,
36 	NBD_CMD_FLUSH = 3,
37 	NBD_CMD_TRIM = 4
38 };
39 
40 /* values for flags field */
41 #define NBD_FLAG_HAS_FLAGS    (1 << 0) /* nbd-server supports flags */
42 #define NBD_FLAG_READ_ONLY    (1 << 1) /* device is read-only */
43 #define NBD_FLAG_SEND_FLUSH   (1 << 2) /* can flush writeback cache */
44 /* there is a gap here to match userspace */
45 #define NBD_FLAG_SEND_TRIM    (1 << 5) /* send trim/discard */
46 
47 #define nbd_cmd(req) ((req)->cmd[0])
48 
49 /* userspace doesn't need the nbd_device structure */
50 
51 /* These are sent over the network in the request/reply magic fields */
52 
53 #define NBD_REQUEST_MAGIC 0x25609513
54 #define NBD_REPLY_MAGIC 0x67446698
55 /* Do *not* use magics: 0x12560953 0x96744668. */
56 
57 /*
58  * This is the packet used for communication between client and
59  * server. All data are in network byte order.
60  */
61 struct nbd_request {
62 	__be32 magic;
63 	__be32 type;	/* == READ || == WRITE 	*/
64 	char handle[8];
65 	__be64 from;
66 	__be32 len;
67 } __attribute__((packed));
68 
69 /*
70  * This is the reply packet that nbd-server sends back to the client after
71  * it has completed an I/O request (or an error occurs).
72  */
73 struct nbd_reply {
74 	__be32 magic;
75 	__be32 error;		/* 0 = ok, else error	*/
76 	char handle[8];		/* handle you got from request	*/
77 };
78 #endif /* _UAPILINUX_NBD_H */
79