rfkill.h (6607B) - Raw
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 __RFKILL_H 19 #define __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 */ 43 enum 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 */ 65 enum 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 */ 77 enum 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 */ 93 struct 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 */ 116 struct 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 * Additionally, some other userspace (bluez, g-s-d) was reading with a 163 * large size but as streaming reads rather than message-based, or with 164 * too strict checks for the returned size. So eventually, we completely 165 * reverted this, and extended messages need to be opted in to by using 166 * an ioctl: 167 * 168 * ioctl(fd, RFKILL_IOCTL_MAX_SIZE, sizeof(struct rfkill_event_ext)); 169 * 170 * Userspace using &struct rfkill_event_ext and the ioctl must adhere to 171 * the following rules: 172 * 173 * 1. accept short writes, optionally using them to detect that it's 174 * running on an older kernel; 175 * 2. accept short reads, knowing that this means it's running on an 176 * older kernel; 177 * 3. treat reads that are as long as requested as acceptable, not 178 * checking against RFKILL_EVENT_SIZE_V1 or such. 179 */ 180 #define RFKILL_EVENT_SIZE_V1 sizeof(struct rfkill_event) 181 182 /* ioctl for turning off rfkill-input (if present) */ 183 #define RFKILL_IOC_MAGIC 'R' 184 #define RFKILL_IOC_NOINPUT 1 185 #define RFKILL_IOCTL_NOINPUT _IO(RFKILL_IOC_MAGIC, RFKILL_IOC_NOINPUT) 186 #define RFKILL_IOC_MAX_SIZE 2 187 #define RFKILL_IOCTL_MAX_SIZE _IOW(RFKILL_IOC_MAGIC, RFKILL_IOC_MAX_SIZE, __u32) 188 189 /* and that's all userspace gets */ 190 191 #endif /* __RFKILL_H */