include/uapi/linux/nbd.h

   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, these are server interaction specific. */
  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 #define NBD_FLAG_SEND_FUA       (1 << 3) /* send FUA (forced unit access) */
  45 /* there is a gap here to match userspace */
  46 #define NBD_FLAG_SEND_TRIM      (1 << 5) /* send trim/discard */
  47 #define NBD_FLAG_CAN_MULTI_CONN (1 << 8)        /* Server supports multiple connections per export. */
  48
  49 /* values for cmd flags in the upper 16 bits of request type */
  50 #define NBD_CMD_FLAG_FUA        (1 << 16) /* FUA (forced unit access) op */
  51
  52 /* These are client behavior specific flags. */
  53 #define NBD_CFLAG_DESTROY_ON_DISCONNECT (1 << 0) /* delete the nbd device on
  54                                                     disconnect. */
  55
  56 /* userspace doesn't need the nbd_device structure */
  57
  58 /* These are sent over the network in the request/reply magic fields */
  59
  60 #define NBD_REQUEST_MAGIC 0x25609513
  61 #define NBD_REPLY_MAGIC 0x67446698
  62 /* Do *not* use magics: 0x12560953 0x96744668. */
  63
  64 /*
  65  * This is the packet used for communication between client and
  66  * server. All data are in network byte order.
  67  */
  68 struct nbd_request {
  69         __be32 magic;
  70         __be32 type;    /* == READ || == WRITE  */
  71         char handle[8];
  72         __be64 from;
  73         __be32 len;
  74 } __attribute__((packed));
  75
  76 /*
  77  * This is the reply packet that nbd-server sends back to the client after
  78  * it has completed an I/O request (or an error occurs).
  79  */
  80 struct nbd_reply {
  81         __be32 magic;
  82         __be32 error;           /* 0 = ok, else error   */
  83         char handle[8];         /* handle you got from request  */
  84 };
  85 #endif /* _UAPILINUX_NBD_H */