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nbd.h
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1 /*
2  * 1999 Copyright (C) Pavel Machek, [email protected] 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 <[email protected]>
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 {
36  /* there is a gap here to match userspace */
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 /* there is a gap here to match userspace */
44 #define NBD_FLAG_SEND_TRIM (1 << 5) /* send trim/discard */
45 
46 #define nbd_cmd(req) ((req)->cmd[0])
47 
48 /* userspace doesn't need the nbd_device structure */
49 
50 /* These are sent over the network in the request/reply magic fields */
51 
52 #define NBD_REQUEST_MAGIC 0x25609513
53 #define NBD_REPLY_MAGIC 0x67446698
54 /* Do *not* use magics: 0x12560953 0x96744668. */
55 
56 /*
57  * This is the packet used for communication between client and
58  * server. All data are in network byte order.
59  */
60 struct nbd_request {
62  __be32 type; /* == READ || == WRITE */
63  char handle[8];
66 } __attribute__((packed));
67 
68 /*
69  * This is the reply packet that nbd-server sends back to the client after
70  * it has completed an I/O request (or an error occurs).
71  */
72 struct nbd_reply {
74  __be32 error; /* 0 = ok, else error */
75  char handle[8]; /* handle you got from request */
76 };
77 #endif /* _UAPILINUX_NBD_H */