LXR linux/include/uapi/linux/nbd.h

   1/* SPDX-License-Identifier: GPL-1.0+ WITH Linux-syscall-note */
   2/*
   3 * 1999 Copyright (C) Pavel Machek, pavel@ucw.cz. This code is GPL.
   4 * 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)
   5 *            Made nbd_end_request() use the io_request_lock
   6 * 2001 Copyright (C) Steven Whitehouse
   7 *            New nbd_end_request() for compatibility with new linux block
   8 *            layer code.
   9 * 2003/06/24 Louis D. Langholtz <ldl@aros.net>
  10 *            Removed unneeded blksize_bits field from nbd_device struct.
  11 *            Cleanup PARANOIA usage & code.
  12 * 2004/02/19 Paul Clements
  13 *            Removed PARANOIA, plus various cleanup and comments
  14 */
  15
  16#ifndef _UAPILINUX_NBD_H
  17#define _UAPILINUX_NBD_H
  18
  19#include <linux/types.h>
  20
  21#define NBD_SET_SOCK    _IO( 0xab, 0 )
  22#define NBD_SET_BLKSIZE _IO( 0xab, 1 )
  23#define NBD_SET_SIZE    _IO( 0xab, 2 )
  24#define NBD_DO_IT       _IO( 0xab, 3 )
  25#define NBD_CLEAR_SOCK  _IO( 0xab, 4 )
  26#define NBD_CLEAR_QUE   _IO( 0xab, 5 )
  27#define NBD_PRINT_DEBUG _IO( 0xab, 6 )
  28#define NBD_SET_SIZE_BLOCKS     _IO( 0xab, 7 )
  29#define NBD_DISCONNECT  _IO( 0xab, 8 )
  30#define NBD_SET_TIMEOUT _IO( 0xab, 9 )
  31#define NBD_SET_FLAGS   _IO( 0xab, 10)
  32
  33enum {
  34        NBD_CMD_READ = 0,
  35        NBD_CMD_WRITE = 1,
  36        NBD_CMD_DISC = 2,
  37        NBD_CMD_FLUSH = 3,
  38        NBD_CMD_TRIM = 4
  39};
  40
  41/* values for flags field, these are server interaction specific. */
  42#define NBD_FLAG_HAS_FLAGS      (1 << 0) /* nbd-server supports flags */
  43#define NBD_FLAG_READ_ONLY      (1 << 1) /* device is read-only */
  44#define NBD_FLAG_SEND_FLUSH     (1 << 2) /* can flush writeback cache */
  45#define NBD_FLAG_SEND_FUA       (1 << 3) /* send FUA (forced unit access) */
  46/* there is a gap here to match userspace */
  47#define NBD_FLAG_SEND_TRIM      (1 << 5) /* send trim/discard */
  48#define NBD_FLAG_CAN_MULTI_CONN (1 << 8)        /* Server supports multiple connections per export. */
  49
  50/* values for cmd flags in the upper 16 bits of request type */
  51#define NBD_CMD_FLAG_FUA        (1 << 16) /* FUA (forced unit access) op */
  52
  53/* These are client behavior specific flags. */
  54#define NBD_CFLAG_DESTROY_ON_DISCONNECT (1 << 0) /* delete the nbd device on
  55                                                    disconnect. */
  56#define NBD_CFLAG_DISCONNECT_ON_CLOSE (1 << 1) /* disconnect the nbd device on
  57                                                *  close by last opener.
  58                                                */
  59
  60/* userspace doesn't need the nbd_device structure */
  61
  62/* These are sent over the network in the request/reply magic fields */
  63
  64#define NBD_REQUEST_MAGIC 0x25609513
  65#define NBD_REPLY_MAGIC 0x67446698
  66/* Do *not* use magics: 0x12560953 0x96744668. */
  67
  68/*
  69 * This is the packet used for communication between client and
  70 * server. All data are in network byte order.
  71 */
  72struct nbd_request {
  73        __be32 magic;
  74        __be32 type;    /* == READ || == WRITE  */
  75        char handle[8];
  76        __be64 from;
  77        __be32 len;
  78} __attribute__((packed));
  79
  80/*
  81 * This is the reply packet that nbd-server sends back to the client after
  82 * it has completed an I/O request (or an error occurs).
  83 */
  84struct nbd_reply {
  85        __be32 magic;
  86        __be32 error;           /* 0 = ok, else error   */
  87        char handle[8];         /* handle you got from request  */
  88};
  89#endif /* _UAPILINUX_NBD_H */
  90