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 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 #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 #define NBD_CMD_MASK_COMMAND 0x0000ffff
  41 #define NBD_CMD_SHIFT (16)
  42 #define NBD_CMD_FLAG_FUA ((1 << 0) << NBD_CMD_SHIFT)
  43
  44 /* values for flags field */
  45 #define NBD_FLAG_HAS_FLAGS      (1 << 0)        /* Flags are there */
  46 #define NBD_FLAG_READ_ONLY      (1 << 1)        /* Device is read-only */
  47 #define NBD_FLAG_SEND_FLUSH     (1 << 2)        /* Send FLUSH */
  48 #define NBD_FLAG_SEND_FUA       (1 << 3)        /* Send FUA (Force Unit Access) */
  49 #define NBD_FLAG_ROTATIONAL     (1 << 4)        /* Use elevator algorithm - rotational media */
  50 #define NBD_FLAG_SEND_TRIM      (1 << 5)        /* Send TRIM (discard) */
  51
  52 #define nbd_cmd(req) ((req)->cmd[0])
  53
  54 /* userspace doesn't need the nbd_device structure */
  55
  56 /* These are sent over the network in the request/reply magic fields */
  57
  58 #define NBD_REQUEST_MAGIC 0x25609513
  59 #define NBD_REPLY_MAGIC 0x67446698
  60 /* Do *not* use magics: 0x12560953 0x96744668. */
  61
  62 /*
  63  * This is the packet used for communication between client and
  64  * server. All data are in network byte order.
  65  */
  66 struct nbd_request {
  67         uint32_t magic;
  68         uint32_t type;  /* == READ || == WRITE  */
  69         char handle[8];
  70         uint64_t from;
  71         uint32_t len;
  72 } __attribute__ ((packed));
  73
  74 /*
  75  * This is the reply packet that nbd-server sends back to the client after
  76  * it has completed an I/O request (or an error occurs).
  77  */
  78 struct nbd_reply {
  79         uint32_t magic;
  80         uint32_t error;         /* 0 = ok, else error   */
  81         char handle[8];         /* handle you got from request  */
  82 };
  83 #endif