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         NBD_CMD_CACHE = 5,
  39         NBD_CMD_WRITE_ZEROES = 6,
  40         NBD_CMD_BLOCK_STATUS = 7,
  41         NBD_CMD_RESIZE = 8
  42 };
  43
  44 #define NBD_CMD_MASK_COMMAND 0x0000ffff
  45 #define NBD_CMD_SHIFT (16)
  46 #define NBD_CMD_FLAG_FUA ((1 << 0) << NBD_CMD_SHIFT)
  47 #define NBD_CMD_FLAG_NO_HOLE ((1 << 1) << NBD_CMD_SHIFT)
  48 #define NBD_CMD_FLAG_DF  ((1 << 2) << NBD_CMD_SHIFT)
  49
  50 /* values for flags field */
  51 #define NBD_FLAG_HAS_FLAGS      (1 << 0)        /* Flags are there */
  52 #define NBD_FLAG_READ_ONLY      (1 << 1)        /* Device is read-only */
  53 #define NBD_FLAG_SEND_FLUSH     (1 << 2)        /* Send FLUSH */
  54 #define NBD_FLAG_SEND_FUA       (1 << 3)        /* Send FUA (Force Unit Access) */
  55 #define NBD_FLAG_ROTATIONAL     (1 << 4)        /* Use elevator algorithm - rotational media */
  56 #define NBD_FLAG_SEND_TRIM      (1 << 5)        /* Send TRIM (discard) */
  57 #define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6)     /* Send NBD_CMD_WRITE_ZEROES */
  58 #define NBD_FLAG_SEND_DF        (1 << 7)        /* Send NBD_CMD_FLAG_DF */
  59 #define NBD_FLAG_CAN_MULTI_CONN (1 << 8)        /* multiple connections are okay */
  60
  61 #define nbd_cmd(req) ((req)->cmd[0])
  62
  63 /* userspace doesn't need the nbd_device structure */
  64
  65 /* These are sent over the network in the request/reply magic fields */
  66
  67 #define NBD_REQUEST_MAGIC 0x25609513
  68 #define NBD_REPLY_MAGIC 0x67446698
  69 #define NBD_STRUCTURED_REPLY_MAGIC 0x668e33ef
  70
  71 /* for the trace log, not part of the protocol, not sent over the wire */
  72 #define NBD_TRACELOG_MAGIC 0x25609514
  73
  74 #define NBD_OPT_REPLY_MAGIC 0x3e889045565a9LL
  75
  76 #define NBD_REPLY_TYPE_NONE             (0)
  77 #define NBD_REPLY_TYPE_OFFSET_DATA      (1)
  78 #define NBD_REPLY_TYPE_OFFSET_HOLE      (2)
  79 #define NBD_REPLY_TYPE_BLOCK_STATUS     (3)
  80
  81 #define NBD_REPLY_TYPE_ERROR            ((1 << 15) + 1)
  82 #define NBD_REPLY_TYPE_ERROR_OFFSET     ((1 << 15) + 2)
  83
  84 #define NBD_REPLY_FLAG_DONE             (1 << 0)
  85
  86 /*
  87  * This is the packet used for communication between client and
  88  * server. All data are in network byte order.
  89  */
  90 struct nbd_request {
  91         uint32_t magic;
  92         uint32_t type;  /* == READ || == WRITE  */
  93         uint64_t cookie;
  94         uint64_t from;
  95         uint32_t len;
  96 } __attribute__ ((packed));
  97
  98 /*
  99  * This is the reply packet that nbd-server sends back to the client after
 100  * it has completed an I/O request (or an error occurs).
 101  */
 102 struct nbd_reply {
 103         uint32_t magic;
 104         uint32_t error;         /* 0 = ok, else error   */
 105         uint64_t cookie;        /* cookie you got from request  */
 106 } __attribute__ ((packed));
 107
 108 /*
 109  * The reply packet for structured replies
 110  */
 111 struct nbd_structured_reply {
 112         uint32_t magic;
 113         uint16_t flags;
 114         uint16_t type;
 115         uint64_t cookie;
 116         uint32_t paylen;
 117 } __attribute__ ((packed));
 118
 119 struct nbd_structured_error_payload {
 120         uint32_t error;
 121         uint16_t msglen;
 122 } __attribute__ ((packed));
 123
 124 #define NBD_EPERM 1
 125 #define NBD_EIO 5
 126 #define NBD_ENOMEM 12
 127 #define NBD_EINVAL 22
 128 #define NBD_ENOSPC 28
 129 #define NBD_EOVERFLOW 75
 130 #define NBD_ENOTSUP 95
 131 #define NBD_ESHUTDOWN 108
 132
 133 #endif