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Editing: rfkill.h
/* * Copyright (C) 2006 - 2007 Ivo van Doorn * Copyright (C) 2007 Dmitry Torokhov * Copyright 2009 Johannes Berg <johannes@sipsolutions.net> * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #ifndef __RFKILL_H #define __RFKILL_H #include <linux/types.h> /* define userspace visible states */ #define RFKILL_STATE_SOFT_BLOCKED 0 #define RFKILL_STATE_UNBLOCKED 1 #define RFKILL_STATE_HARD_BLOCKED 2 /** * enum rfkill_type - type of rfkill switch. * * @RFKILL_TYPE_ALL: toggles all switches (requests only - not a switch type) * @RFKILL_TYPE_WLAN: switch is on a 802.11 wireless network device. * @RFKILL_TYPE_BLUETOOTH: switch is on a bluetooth device. * @RFKILL_TYPE_UWB: switch is on a ultra wideband device. * @RFKILL_TYPE_WIMAX: switch is on a WiMAX device. * @RFKILL_TYPE_WWAN: switch is on a wireless WAN device. * @RFKILL_TYPE_GPS: switch is on a GPS device. * @RFKILL_TYPE_FM: switch is on a FM radio device. * @RFKILL_TYPE_NFC: switch is on an NFC device. * @NUM_RFKILL_TYPES: number of defined rfkill types */ enum rfkill_type { RFKILL_TYPE_ALL = 0, RFKILL_TYPE_WLAN, RFKILL_TYPE_BLUETOOTH, RFKILL_TYPE_UWB, RFKILL_TYPE_WIMAX, RFKILL_TYPE_WWAN, RFKILL_TYPE_GPS, RFKILL_TYPE_FM, RFKILL_TYPE_NFC, NUM_RFKILL_TYPES, }; /** * enum rfkill_operation - operation types * @RFKILL_OP_ADD: a device was added * @RFKILL_OP_DEL: a device was removed * @RFKILL_OP_CHANGE: a device's state changed -- userspace changes one device * @RFKILL_OP_CHANGE_ALL: userspace changes all devices (of a type, or all) * into a state, also updating the default state used for devices that * are hot-plugged later. */ enum rfkill_operation { RFKILL_OP_ADD = 0, RFKILL_OP_DEL, RFKILL_OP_CHANGE, RFKILL_OP_CHANGE_ALL, }; /** * enum rfkill_hard_block_reasons - hard block reasons * @RFKILL_HARD_BLOCK_SIGNAL: the hardware rfkill signal is active * @RFKILL_HARD_BLOCK_NOT_OWNER: the NIC is not owned by the host */ enum rfkill_hard_block_reasons { RFKILL_HARD_BLOCK_SIGNAL = 1 << 0, RFKILL_HARD_BLOCK_NOT_OWNER = 1 << 1, }; /** * struct rfkill_event - events for userspace on /dev/rfkill * @idx: index of dev rfkill * @type: type of the rfkill struct * @op: operation code * @hard: hard state (0/1) * @soft: soft state (0/1) * * Structure used for userspace communication on /dev/rfkill, * used for events from the kernel and control to the kernel. */ struct rfkill_event { __u32 idx; __u8 type; __u8 op; __u8 soft; __u8 hard; } __attribute__((packed)); /** * struct rfkill_event_ext - events for userspace on /dev/rfkill * @idx: index of dev rfkill * @type: type of the rfkill struct * @op: operation code * @hard: hard state (0/1) * @soft: soft state (0/1) * @hard_block_reasons: valid if hard is set. One or several reasons from * &enum rfkill_hard_block_reasons. * * Structure used for userspace communication on /dev/rfkill, * used for events from the kernel and control to the kernel. * * See the extensibility docs below. */ struct rfkill_event_ext { __u32 idx; __u8 type; __u8 op; __u8 soft; __u8 hard; /* * older kernels will accept/send only up to this point, * and if extended further up to any chunk marked below */ __u8 hard_block_reasons; } __attribute__((packed)); /** * DOC: Extensibility * * Originally, we had planned to allow backward and forward compatible * changes by just adding fields at the end of the structure that are * then not reported on older kernels on read(), and not written to by * older kernels on write(), with the kernel reporting the size it did * accept as the result. * * This would have allowed userspace to detect on read() and write() * which kernel structure version it was dealing with, and if was just * recompiled it would have gotten the new fields, but obviously not * accessed them, but things should've continued to work. * * Unfortunately, while actually exercising this mechanism to add the * hard block reasons field, we found that userspace (notably systemd) * did all kinds of fun things not in line with this scheme: * * 1. treat the (expected) short writes as an error; * 2. ask to read sizeof(struct rfkill_event) but then compare the * actual return value to RFKILL_EVENT_SIZE_V1 and treat any * mismatch as an error. * * As a consequence, just recompiling with a new struct version caused * things to no longer work correctly on old and new kernels. * * Hence, we've rolled back &struct rfkill_event to the original version * and added &struct rfkill_event_ext. This effectively reverts to the * old behaviour for all userspace, unless it explicitly opts in to the * rules outlined here by using the new &struct rfkill_event_ext. * * Additionally, some other userspace (bluez, g-s-d) was reading with a * large size but as streaming reads rather than message-based, or with * too strict checks for the returned size. So eventually, we completely * reverted this, and extended messages need to be opted in to by using * an ioctl: * * ioctl(fd, RFKILL_IOCTL_MAX_SIZE, sizeof(struct rfkill_event_ext)); * * Userspace using &struct rfkill_event_ext and the ioctl must adhere to * the following rules: * * 1. accept short writes, optionally using them to detect that it's * running on an older kernel; * 2. accept short reads, knowing that this means it's running on an * older kernel; * 3. treat reads that are as long as requested as acceptable, not * checking against RFKILL_EVENT_SIZE_V1 or such. */ #define RFKILL_EVENT_SIZE_V1 sizeof(struct rfkill_event) /* ioctl for turning off rfkill-input (if present) */ #define RFKILL_IOC_MAGIC 'R' #define RFKILL_IOC_NOINPUT 1 #define RFKILL_IOCTL_NOINPUT _IO(RFKILL_IOC_MAGIC, RFKILL_IOC_NOINPUT) #define RFKILL_IOC_MAX_SIZE 2 #define RFKILL_IOCTL_MAX_SIZE _IOW(RFKILL_IOC_MAGIC, RFKILL_IOC_EXT_SIZE, __u32) /* and that's all userspace gets */ #endif /* __RFKILL_H */
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