init/keychords.cpp - android-core - Git at Google

 /*
  * Copyright (C) 2010 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "keychords.h"

 #include <dirent.h>
 #include <fcntl.h>
 #include <linux/input.h>
 #include <sys/cdefs.h>
 #include <sys/inotify.h>
 #include <sys/ioctl.h>
 #include <sys/types.h>
 #include <unistd.h>

 #include <algorithm>
 #include <functional>
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>

 #include <android-base/logging.h>

 namespace android {
 namespace init {

 Keychords::Keychords() : epoll_(nullptr), inotify_fd_(-1) {}

 Keychords::~Keychords() noexcept {
     if (inotify_fd_ >= 0) {
         epoll_->UnregisterHandler(inotify_fd_);
         ::close(inotify_fd_);
     }
     while (!registration_.empty()) GeteventCloseDevice(registration_.begin()->first);
 }

 Keychords::Mask::Mask(size_t bit) : bits_((bit + sizeof(mask_t) - 1) / sizeof(mask_t), 0) {}

 void Keychords::Mask::SetBit(size_t bit, bool value) {
     auto idx = bit / (kBitsPerByte * sizeof(mask_t));
     if (idx >= bits_.size()) return;
     if (value) {
         bits_[idx] |= mask_t(1) << (bit % (kBitsPerByte * sizeof(mask_t)));
     } else {
         bits_[idx] &= ~(mask_t(1) << (bit % (kBitsPerByte * sizeof(mask_t))));
     }
 }

 bool Keychords::Mask::GetBit(size_t bit) const {
     auto idx = bit / (kBitsPerByte * sizeof(mask_t));
     return bits_[idx] & (mask_t(1) << (bit % (kBitsPerByte * sizeof(mask_t))));
 }

 size_t Keychords::Mask::bytesize() const {
     return bits_.size() * sizeof(mask_t);
 }

 void* Keychords::Mask::data() {
     return bits_.data();
 }

 size_t Keychords::Mask::size() const {
     return bits_.size() * sizeof(mask_t) * kBitsPerByte;
 }

 void Keychords::Mask::resize(size_t bit) {
     auto idx = bit / (kBitsPerByte * sizeof(mask_t));
     if (idx >= bits_.size()) {
         bits_.resize(idx + 1, 0);
     }
 }

 Keychords::Mask::operator bool() const {
     for (size_t i = 0; i < bits_.size(); ++i) {
         if (bits_[i]) return true;
     }
     return false;
 }

 Keychords::Mask Keychords::Mask::operator&(const Keychords::Mask& rval) const {
     auto len = std::min(bits_.size(), rval.bits_.size());
     Keychords::Mask ret;
     ret.bits_.resize(len);
     for (size_t i = 0; i < len; ++i) {
         ret.bits_[i] = bits_[i] & rval.bits_[i];
     }
     return ret;
 }

 void Keychords::Mask::operator|=(const Keychords::Mask& rval) {
     auto len = rval.bits_.size();
     bits_.resize(len);
     for (size_t i = 0; i < len; ++i) {
         bits_[i] |= rval.bits_[i];
     }
 }

 Keychords::Entry::Entry() : notified(false) {}

 void Keychords::LambdaCheck() {
     for (auto& [keycodes, entry] : entries_) {
         auto found = true;
         for (auto& code : keycodes) {
             if (!current_.GetBit(code)) {
                 entry.notified = false;
                 found = false;
                 break;
             }
         }
         if (!found) continue;
         if (entry.notified) continue;
         entry.notified = true;
         handler_(keycodes);
     }
 }

 void Keychords::LambdaHandler(int fd) {
     input_event event;
     auto res = TEMP_FAILURE_RETRY(::read(fd, &event, sizeof(event)));
     if ((res != sizeof(event)) || (event.type != EV_KEY)) return;
     current_.SetBit(event.code, event.value);
     LambdaCheck();
 }

 bool Keychords::GeteventEnable(int fd) {
     // Make sure it is an event channel, should pass this ioctl call
     int version;
     if (::ioctl(fd, EVIOCGVERSION, &version)) return false;

 #ifdef EVIOCSMASK
     static auto EviocsmaskSupported = true;
     if (EviocsmaskSupported) {
         Keychords::Mask mask(EV_KEY);
         mask.SetBit(EV_KEY);
         input_mask msg = {};
         msg.type = EV_SYN;
         msg.codes_size = mask.bytesize();
         msg.codes_ptr = reinterpret_cast<uintptr_t>(mask.data());
         if (::ioctl(fd, EVIOCSMASK, &msg) == -1) {
             PLOG(WARNING) << "EVIOCSMASK not supported";
             EviocsmaskSupported = false;
         }
     }
 #endif

     Keychords::Mask mask;
     for (auto& [keycodes, entry] : entries_) {
         for (auto& code : keycodes) {
             mask.resize(code);
             mask.SetBit(code);
         }
     }

     current_.resize(mask.size());
     Keychords::Mask available(mask.size());
     auto res = ::ioctl(fd, EVIOCGBIT(EV_KEY, available.bytesize()), available.data());
     if (res == -1) return false;
     if (!(available & mask)) return false;

 #ifdef EVIOCSMASK
     if (EviocsmaskSupported) {
         input_mask msg = {};
         msg.type = EV_KEY;
         msg.codes_size = mask.bytesize();
         msg.codes_ptr = reinterpret_cast<uintptr_t>(mask.data());
         ::ioctl(fd, EVIOCSMASK, &msg);
     }
 #endif

     Keychords::Mask set(mask.size());
     res = ::ioctl(fd, EVIOCGKEY(res), set.data());
     if (res > 0) {
         current_ |= mask & available & set;
         LambdaCheck();
     }
     epoll_->RegisterHandler(fd, [this, fd]() { this->LambdaHandler(fd); });
     return true;
 }

 void Keychords::GeteventOpenDevice(const std::string& device) {
     if (registration_.count(device)) return;
     auto fd = TEMP_FAILURE_RETRY(::open(device.c_str(), O_RDONLY | O_CLOEXEC));
     if (fd == -1) {
         PLOG(ERROR) << "Can not open " << device;
         return;
     }
     if (!GeteventEnable(fd)) {
         ::close(fd);
     } else {
         registration_.emplace(device, fd);
     }
 }

 void Keychords::GeteventCloseDevice(const std::string& device) {
     auto it = registration_.find(device);
     if (it == registration_.end()) return;
     auto fd = (*it).second;
     epoll_->UnregisterHandler(fd);
     registration_.erase(it);
     ::close(fd);
 }

 void Keychords::InotifyHandler() {
     unsigned char buf[512];  // History shows 32-64 bytes typical

     auto res = TEMP_FAILURE_RETRY(::read(inotify_fd_, buf, sizeof(buf)));
     if (res < 0) {
         PLOG(WARNING) << "could not get event";
         return;
     }

     auto event_buf = buf;
     while (static_cast<size_t>(res) >= sizeof(inotify_event)) {
         auto event = reinterpret_cast<inotify_event*>(event_buf);
         auto event_size = sizeof(inotify_event) + event->len;
         if (static_cast<size_t>(res) < event_size) break;
         if (event->len) {
             std::string devname(kDevicePath);
             devname += '/';
             devname += event->name;
             if (event->mask & IN_CREATE) {
                 GeteventOpenDevice(devname);
             } else {
                 GeteventCloseDevice(devname);
             }
         }
         res -= event_size;
         event_buf += event_size;
     }
 }

 void Keychords::GeteventOpenDevice() {
     inotify_fd_ = ::inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
     if (inotify_fd_ < 0) {
         PLOG(WARNING) << "Could not instantiate inotify for " << kDevicePath;
     } else if (::inotify_add_watch(inotify_fd_, kDevicePath, IN_DELETE | IN_CREATE | IN_ONLYDIR) <
                0) {
         PLOG(WARNING) << "Could not add watch for " << kDevicePath;
         ::close(inotify_fd_);
         inotify_fd_ = -1;
     }

     std::unique_ptr<DIR, decltype(&closedir)> device(opendir(kDevicePath), closedir);
     if (device) {
         dirent* entry;
         while ((entry = readdir(device.get()))) {
             if (entry->d_name[0] == '.') continue;
             std::string devname(kDevicePath);
             devname += '/';
             devname += entry->d_name;
             GeteventOpenDevice(devname);
         }
     }

     if (inotify_fd_ >= 0) {
         epoll_->RegisterHandler(inotify_fd_, [this]() { this->InotifyHandler(); });
     }
 }

 void Keychords::Register(const std::vector<int>& keycodes) {
     if (keycodes.empty()) return;
     entries_.try_emplace(keycodes, Entry());
 }

 void Keychords::Start(Epoll* epoll, std::function<void(const std::vector<int>&)> handler) {
     epoll_ = epoll;
     handler_ = handler;
     if (entries_.size()) GeteventOpenDevice();
 }

 }  // namespace init
 }  // namespace android
	/*
	* Copyright (C) 2010 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "keychords.h"

	#include <dirent.h>
	#include <fcntl.h>
	#include <linux/input.h>
	#include <sys/cdefs.h>
	#include <sys/inotify.h>
	#include <sys/ioctl.h>
	#include <sys/types.h>
	#include <unistd.h>

	#include <algorithm>
	#include <functional>
	#include <map>
	#include <memory>
	#include <string>
	#include <vector>

	#include <android-base/logging.h>

	namespace android {
	namespace init {

	Keychords::Keychords() : epoll_(nullptr), inotify_fd_(-1) {}

	Keychords::~Keychords() noexcept {
	if (inotify_fd_ >= 0) {
	epoll_->UnregisterHandler(inotify_fd_);
	::close(inotify_fd_);
	}
	while (!registration_.empty()) GeteventCloseDevice(registration_.begin()->first);
	}

	Keychords::Mask::Mask(size_t bit) : bits_((bit + sizeof(mask_t) - 1) / sizeof(mask_t), 0) {}

	void Keychords::Mask::SetBit(size_t bit, bool value) {
	auto idx = bit / (kBitsPerByte * sizeof(mask_t));
	if (idx >= bits_.size()) return;
	if (value) {
	bits_[idx] \|= mask_t(1) << (bit % (kBitsPerByte * sizeof(mask_t)));
	} else {
	bits_[idx] &= ~(mask_t(1) << (bit % (kBitsPerByte * sizeof(mask_t))));
	}
	}

	bool Keychords::Mask::GetBit(size_t bit) const {
	auto idx = bit / (kBitsPerByte * sizeof(mask_t));
	return bits_[idx] & (mask_t(1) << (bit % (kBitsPerByte * sizeof(mask_t))));
	}

	size_t Keychords::Mask::bytesize() const {
	return bits_.size() * sizeof(mask_t);
	}

	void* Keychords::Mask::data() {
	return bits_.data();
	}

	size_t Keychords::Mask::size() const {
	return bits_.size() * sizeof(mask_t) * kBitsPerByte;
	}

	void Keychords::Mask::resize(size_t bit) {
	auto idx = bit / (kBitsPerByte * sizeof(mask_t));
	if (idx >= bits_.size()) {
	bits_.resize(idx + 1, 0);
	}
	}

	Keychords::Mask::operator bool() const {
	for (size_t i = 0; i < bits_.size(); ++i) {
	if (bits_[i]) return true;
	}
	return false;
	}

	Keychords::Mask Keychords::Mask::operator&(const Keychords::Mask& rval) const {
	auto len = std::min(bits_.size(), rval.bits_.size());
	Keychords::Mask ret;
	ret.bits_.resize(len);
	for (size_t i = 0; i < len; ++i) {
	ret.bits_[i] = bits_[i] & rval.bits_[i];
	}
	return ret;
	}

	void Keychords::Mask::operator\|=(const Keychords::Mask& rval) {
	auto len = rval.bits_.size();
	bits_.resize(len);
	for (size_t i = 0; i < len; ++i) {
	bits_[i] \|= rval.bits_[i];
	}
	}

	Keychords::Entry::Entry() : notified(false) {}

	void Keychords::LambdaCheck() {
	for (auto& [keycodes, entry] : entries_) {
	auto found = true;
	for (auto& code : keycodes) {
	if (!current_.GetBit(code)) {
	entry.notified = false;
	found = false;
	break;
	}
	}
	if (!found) continue;
	if (entry.notified) continue;
	entry.notified = true;
	handler_(keycodes);
	}
	}

	void Keychords::LambdaHandler(int fd) {
	input_event event;
	auto res = TEMP_FAILURE_RETRY(::read(fd, &event, sizeof(event)));
	if ((res != sizeof(event)) \|\| (event.type != EV_KEY)) return;
	current_.SetBit(event.code, event.value);
	LambdaCheck();
	}

	bool Keychords::GeteventEnable(int fd) {
	// Make sure it is an event channel, should pass this ioctl call
	int version;
	if (::ioctl(fd, EVIOCGVERSION, &version)) return false;

	#ifdef EVIOCSMASK
	static auto EviocsmaskSupported = true;
	if (EviocsmaskSupported) {
	Keychords::Mask mask(EV_KEY);
	mask.SetBit(EV_KEY);
	input_mask msg = {};
	msg.type = EV_SYN;
	msg.codes_size = mask.bytesize();
	msg.codes_ptr = reinterpret_cast<uintptr_t>(mask.data());
	if (::ioctl(fd, EVIOCSMASK, &msg) == -1) {
	PLOG(WARNING) << "EVIOCSMASK not supported";
	EviocsmaskSupported = false;
	}
	}
	#endif

	Keychords::Mask mask;
	for (auto& [keycodes, entry] : entries_) {
	for (auto& code : keycodes) {
	mask.resize(code);
	mask.SetBit(code);
	}
	}

	current_.resize(mask.size());
	Keychords::Mask available(mask.size());
	auto res = ::ioctl(fd, EVIOCGBIT(EV_KEY, available.bytesize()), available.data());
	if (res == -1) return false;
	if (!(available & mask)) return false;

	#ifdef EVIOCSMASK
	if (EviocsmaskSupported) {
	input_mask msg = {};
	msg.type = EV_KEY;
	msg.codes_size = mask.bytesize();
	msg.codes_ptr = reinterpret_cast<uintptr_t>(mask.data());
	::ioctl(fd, EVIOCSMASK, &msg);
	}
	#endif

	Keychords::Mask set(mask.size());
	res = ::ioctl(fd, EVIOCGKEY(res), set.data());
	if (res > 0) {
	current_ \|= mask & available & set;
	LambdaCheck();
	}
	epoll_->RegisterHandler(fd, [this, fd]() { this->LambdaHandler(fd); });
	return true;
	}

	void Keychords::GeteventOpenDevice(const std::string& device) {
	if (registration_.count(device)) return;
	auto fd = TEMP_FAILURE_RETRY(::open(device.c_str(), O_RDONLY \| O_CLOEXEC));
	if (fd == -1) {
	PLOG(ERROR) << "Can not open " << device;
	return;
	}
	if (!GeteventEnable(fd)) {
	::close(fd);
	} else {
	registration_.emplace(device, fd);
	}
	}

	void Keychords::GeteventCloseDevice(const std::string& device) {
	auto it = registration_.find(device);
	if (it == registration_.end()) return;
	auto fd = (*it).second;
	epoll_->UnregisterHandler(fd);
	registration_.erase(it);
	::close(fd);
	}

	void Keychords::InotifyHandler() {
	unsigned char buf[512]; // History shows 32-64 bytes typical

	auto res = TEMP_FAILURE_RETRY(::read(inotify_fd_, buf, sizeof(buf)));
	if (res < 0) {
	PLOG(WARNING) << "could not get event";
	return;
	}

	auto event_buf = buf;
	while (static_cast<size_t>(res) >= sizeof(inotify_event)) {
	auto event = reinterpret_cast<inotify_event*>(event_buf);
	auto event_size = sizeof(inotify_event) + event->len;
	if (static_cast<size_t>(res) < event_size) break;
	if (event->len) {
	std::string devname(kDevicePath);
	devname += '/';
	devname += event->name;
	if (event->mask & IN_CREATE) {
	GeteventOpenDevice(devname);
	} else {
	GeteventCloseDevice(devname);
	}
	}
	res -= event_size;
	event_buf += event_size;
	}
	}

	void Keychords::GeteventOpenDevice() {
	inotify_fd_ = ::inotify_init1(IN_NONBLOCK \| IN_CLOEXEC);
	if (inotify_fd_ < 0) {
	PLOG(WARNING) << "Could not instantiate inotify for " << kDevicePath;
	} else if (::inotify_add_watch(inotify_fd_, kDevicePath, IN_DELETE \| IN_CREATE \| IN_ONLYDIR) <
	0) {
	PLOG(WARNING) << "Could not add watch for " << kDevicePath;
	::close(inotify_fd_);
	inotify_fd_ = -1;
	}

	std::unique_ptr<DIR, decltype(&closedir)> device(opendir(kDevicePath), closedir);
	if (device) {
	dirent* entry;
	while ((entry = readdir(device.get()))) {
	if (entry->d_name[0] == '.') continue;
	std::string devname(kDevicePath);
	devname += '/';
	devname += entry->d_name;
	GeteventOpenDevice(devname);
	}
	}

	if (inotify_fd_ >= 0) {
	epoll_->RegisterHandler(inotify_fd_, [this]() { this->InotifyHandler(); });
	}
	}

	void Keychords::Register(const std::vector<int>& keycodes) {
	if (keycodes.empty()) return;
	entries_.try_emplace(keycodes, Entry());
	}

	void Keychords::Start(Epoll* epoll, std::function<void(const std::vector<int>&)> handler) {
	epoll_ = epoll;
	handler_ = handler;
	if (entries_.size()) GeteventOpenDevice();
	}

	} // namespace init
	} // namespace android