linux/include/uapi/linux/rfkill.h
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   1/*
   2 * Copyright (C) 2006 - 2007 Ivo van Doorn
   3 * Copyright (C) 2007 Dmitry Torokhov
   4 * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
   5 *
   6 * Permission to use, copy, modify, and/or distribute this software for any
   7 * purpose with or without fee is hereby granted, provided that the above
   8 * copyright notice and this permission notice appear in all copies.
   9 *
  10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17 */
  18#ifndef _UAPI__RFKILL_H
  19#define _UAPI__RFKILL_H
  20
  21
  22#include <linux/types.h>
  23
  24/* define userspace visible states */
  25#define RFKILL_STATE_SOFT_BLOCKED       0
  26#define RFKILL_STATE_UNBLOCKED          1
  27#define RFKILL_STATE_HARD_BLOCKED       2
  28
  29/**
  30 * enum rfkill_type - type of rfkill switch.
  31 *
  32 * @RFKILL_TYPE_ALL: toggles all switches (requests only - not a switch type)
  33 * @RFKILL_TYPE_WLAN: switch is on a 802.11 wireless network device.
  34 * @RFKILL_TYPE_BLUETOOTH: switch is on a bluetooth device.
  35 * @RFKILL_TYPE_UWB: switch is on a ultra wideband device.
  36 * @RFKILL_TYPE_WIMAX: switch is on a WiMAX device.
  37 * @RFKILL_TYPE_WWAN: switch is on a wireless WAN device.
  38 * @RFKILL_TYPE_GPS: switch is on a GPS device.
  39 * @RFKILL_TYPE_FM: switch is on a FM radio device.
  40 * @RFKILL_TYPE_NFC: switch is on an NFC device.
  41 * @NUM_RFKILL_TYPES: number of defined rfkill types
  42 */
  43enum rfkill_type {
  44        RFKILL_TYPE_ALL = 0,
  45        RFKILL_TYPE_WLAN,
  46        RFKILL_TYPE_BLUETOOTH,
  47        RFKILL_TYPE_UWB,
  48        RFKILL_TYPE_WIMAX,
  49        RFKILL_TYPE_WWAN,
  50        RFKILL_TYPE_GPS,
  51        RFKILL_TYPE_FM,
  52        RFKILL_TYPE_NFC,
  53        NUM_RFKILL_TYPES,
  54};
  55
  56/**
  57 * enum rfkill_operation - operation types
  58 * @RFKILL_OP_ADD: a device was added
  59 * @RFKILL_OP_DEL: a device was removed
  60 * @RFKILL_OP_CHANGE: a device's state changed -- userspace changes one device
  61 * @RFKILL_OP_CHANGE_ALL: userspace changes all devices (of a type, or all)
  62 *      into a state, also updating the default state used for devices that
  63 *      are hot-plugged later.
  64 */
  65enum rfkill_operation {
  66        RFKILL_OP_ADD = 0,
  67        RFKILL_OP_DEL,
  68        RFKILL_OP_CHANGE,
  69        RFKILL_OP_CHANGE_ALL,
  70};
  71
  72/**
  73 * enum rfkill_hard_block_reasons - hard block reasons
  74 * @RFKILL_HARD_BLOCK_SIGNAL: the hardware rfkill signal is active
  75 * @RFKILL_HARD_BLOCK_NOT_OWNER: the NIC is not owned by the host
  76 */
  77enum rfkill_hard_block_reasons {
  78        RFKILL_HARD_BLOCK_SIGNAL        = 1 << 0,
  79        RFKILL_HARD_BLOCK_NOT_OWNER     = 1 << 1,
  80};
  81
  82/**
  83 * struct rfkill_event - events for userspace on /dev/rfkill
  84 * @idx: index of dev rfkill
  85 * @type: type of the rfkill struct
  86 * @op: operation code
  87 * @hard: hard state (0/1)
  88 * @soft: soft state (0/1)
  89 *
  90 * Structure used for userspace communication on /dev/rfkill,
  91 * used for events from the kernel and control to the kernel.
  92 */
  93struct rfkill_event {
  94        __u32 idx;
  95        __u8  type;
  96        __u8  op;
  97        __u8  soft;
  98        __u8  hard;
  99} __attribute__((packed));
 100
 101/**
 102 * struct rfkill_event_ext - events for userspace on /dev/rfkill
 103 * @idx: index of dev rfkill
 104 * @type: type of the rfkill struct
 105 * @op: operation code
 106 * @hard: hard state (0/1)
 107 * @soft: soft state (0/1)
 108 * @hard_block_reasons: valid if hard is set. One or several reasons from
 109 *      &enum rfkill_hard_block_reasons.
 110 *
 111 * Structure used for userspace communication on /dev/rfkill,
 112 * used for events from the kernel and control to the kernel.
 113 *
 114 * See the extensibility docs below.
 115 */
 116struct rfkill_event_ext {
 117        __u32 idx;
 118        __u8  type;
 119        __u8  op;
 120        __u8  soft;
 121        __u8  hard;
 122
 123        /*
 124         * older kernels will accept/send only up to this point,
 125         * and if extended further up to any chunk marked below
 126         */
 127
 128        __u8  hard_block_reasons;
 129} __attribute__((packed));
 130
 131/**
 132 * DOC: Extensibility
 133 *
 134 * Originally, we had planned to allow backward and forward compatible
 135 * changes by just adding fields at the end of the structure that are
 136 * then not reported on older kernels on read(), and not written to by
 137 * older kernels on write(), with the kernel reporting the size it did
 138 * accept as the result.
 139 *
 140 * This would have allowed userspace to detect on read() and write()
 141 * which kernel structure version it was dealing with, and if was just
 142 * recompiled it would have gotten the new fields, but obviously not
 143 * accessed them, but things should've continued to work.
 144 *
 145 * Unfortunately, while actually exercising this mechanism to add the
 146 * hard block reasons field, we found that userspace (notably systemd)
 147 * did all kinds of fun things not in line with this scheme:
 148 *
 149 * 1. treat the (expected) short writes as an error;
 150 * 2. ask to read sizeof(struct rfkill_event) but then compare the
 151 *    actual return value to RFKILL_EVENT_SIZE_V1 and treat any
 152 *    mismatch as an error.
 153 *
 154 * As a consequence, just recompiling with a new struct version caused
 155 * things to no longer work correctly on old and new kernels.
 156 *
 157 * Hence, we've rolled back &struct rfkill_event to the original version
 158 * and added &struct rfkill_event_ext. This effectively reverts to the
 159 * old behaviour for all userspace, unless it explicitly opts in to the
 160 * rules outlined here by using the new &struct rfkill_event_ext.
 161 *
 162 * Userspace using &struct rfkill_event_ext must adhere to the following
 163 * rules
 164 *
 165 * 1. accept short writes, optionally using them to detect that it's
 166 *    running on an older kernel;
 167 * 2. accept short reads, knowing that this means it's running on an
 168 *    older kernel;
 169 * 3. treat reads that are as long as requested as acceptable, not
 170 *    checking against RFKILL_EVENT_SIZE_V1 or such.
 171 */
 172#define RFKILL_EVENT_SIZE_V1    sizeof(struct rfkill_event)
 173
 174/* ioctl for turning off rfkill-input (if present) */
 175#define RFKILL_IOC_MAGIC        'R'
 176#define RFKILL_IOC_NOINPUT      1
 177#define RFKILL_IOCTL_NOINPUT    _IO(RFKILL_IOC_MAGIC, RFKILL_IOC_NOINPUT)
 178
 179/* and that's all userspace gets */
 180
 181#endif /* _UAPI__RFKILL_H */
 182