usb/lib/MonitorFfs.cpp - LeafOS-Devices/android_hardware_samsung_slsi-linaro_exynos - Gitiles

 /*
  * Copyright (C) 2020 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.
  */

 #define LOG_TAG "libusbconfigfs"

 #include "include/UsbGadgetCommon.h"

 namespace android {
 namespace hardware {
 namespace usb {
 namespace gadget {

 static volatile bool gadgetPullup;

 MonitorFfs::MonitorFfs(const char* const gadget)
     : mWatchFd(),
       mEndpointList(),
       mLock(),
       mCv(),
       mLockFd(),
       mCurrentUsbFunctionsApplied(false),
       mMonitor(),
       mCallback(NULL),
       mPayload(NULL),
       mGadgetName(gadget),
       mMonitorRunning(false) {
     unique_fd eventFd(eventfd(0, 0));
     if (eventFd == -1) {
         ALOGE("mEventFd failed to create %d", errno);
         abort();
     }

     unique_fd epollFd(epoll_create(2));
     if (epollFd == -1) {
         ALOGE("mEpollFd failed to create %d", errno);
         abort();
     }

     unique_fd inotifyFd(inotify_init());
     if (inotifyFd < 0) {
         ALOGE("inotify init failed");
         abort();
     }

     if (addEpollFd(epollFd, inotifyFd) == -1) abort();

     if (addEpollFd(epollFd, eventFd) == -1) abort();

     mEpollFd = move(epollFd);
     mInotifyFd = move(inotifyFd);
     mEventFd = move(eventFd);
     gadgetPullup = false;
 }

 static void displayInotifyEvent(struct inotify_event* i) {
     ALOGE("    wd =%2d; ", i->wd);
     if (i->cookie > 0) ALOGE("cookie =%4d; ", i->cookie);

     ALOGE("mask = ");
     if (i->mask & IN_ACCESS) ALOGE("IN_ACCESS ");
     if (i->mask & IN_ATTRIB) ALOGE("IN_ATTRIB ");
     if (i->mask & IN_CLOSE_NOWRITE) ALOGE("IN_CLOSE_NOWRITE ");
     if (i->mask & IN_CLOSE_WRITE) ALOGE("IN_CLOSE_WRITE ");
     if (i->mask & IN_CREATE) ALOGE("IN_CREATE ");
     if (i->mask & IN_DELETE) ALOGE("IN_DELETE ");
     if (i->mask & IN_DELETE_SELF) ALOGE("IN_DELETE_SELF ");
     if (i->mask & IN_IGNORED) ALOGE("IN_IGNORED ");
     if (i->mask & IN_ISDIR) ALOGE("IN_ISDIR ");
     if (i->mask & IN_MODIFY) ALOGE("IN_MODIFY ");
     if (i->mask & IN_MOVE_SELF) ALOGE("IN_MOVE_SELF ");
     if (i->mask & IN_MOVED_FROM) ALOGE("IN_MOVED_FROM ");
     if (i->mask & IN_MOVED_TO) ALOGE("IN_MOVED_TO ");
     if (i->mask & IN_OPEN) ALOGE("IN_OPEN ");
     if (i->mask & IN_Q_OVERFLOW) ALOGE("IN_Q_OVERFLOW ");
     if (i->mask & IN_UNMOUNT) ALOGE("IN_UNMOUNT ");
     ALOGE("\n");

     if (i->len > 0) ALOGE("        name = %s\n", i->name);
 }

 void* MonitorFfs::startMonitorFd(void* param) {
     MonitorFfs* monitorFfs = (MonitorFfs*)param;
     char buf[kBufferSize];
     bool writeUdc = true, stopMonitor = false;
     struct epoll_event events[kEpollEvents];
     steady_clock::time_point disconnect;

     bool descriptorWritten = true;
     for (int i = 0; i < static_cast<int>(monitorFfs->mEndpointList.size()); i++) {
         if (access(monitorFfs->mEndpointList.at(i).c_str(), R_OK)) {
             descriptorWritten = false;
             break;
         }
     }

     // notify here if the endpoints are already present.
     if (descriptorWritten) {
         usleep(kPullUpDelay);
         if (!!WriteStringToFile(monitorFfs->mGadgetName, PULLUP_PATH)) {
             lock_guard<mutex> lock(monitorFfs->mLock);
             monitorFfs->mCurrentUsbFunctionsApplied = true;
             monitorFfs->mCallback(monitorFfs->mCurrentUsbFunctionsApplied, monitorFfs->mPayload);
             gadgetPullup = true;
             writeUdc = false;
             ALOGI("GADGET pulled up");
             monitorFfs->mCv.notify_all();
         }
     }

     while (!stopMonitor) {
         int nrEvents = epoll_wait(monitorFfs->mEpollFd, events, kEpollEvents, -1);

         if (nrEvents <= 0) {
             ALOGE("epoll wait did not return descriptor number");
             continue;
         }

         for (int i = 0; i < nrEvents; i++) {
             ALOGI("event=%u on fd=%d\n", events[i].events, events[i].data.fd);

             if (events[i].data.fd == monitorFfs->mInotifyFd) {
                 // Process all of the events in buffer returned by read().
                 int numRead = read(monitorFfs->mInotifyFd, buf, kBufferSize);
                 for (char* p = buf; p < buf + numRead;) {
                     struct inotify_event* event = (struct inotify_event*)p;
                     if (kDebug) displayInotifyEvent(event);

                     p += sizeof(struct inotify_event) + event->len;

                     bool descriptorPresent = true;
                     for (int j = 0; j < static_cast<int>(monitorFfs->mEndpointList.size()); j++) {
                         if (access(monitorFfs->mEndpointList.at(j).c_str(), R_OK)) {
                             if (kDebug) ALOGI("%s absent", monitorFfs->mEndpointList.at(j).c_str());
                             descriptorPresent = false;
                             break;
                         }
                     }

                     if (!descriptorPresent && !writeUdc) {
                         if (kDebug) ALOGI("endpoints not up");
                         writeUdc = true;
                         disconnect = std::chrono::steady_clock::now();
                     } else if (descriptorPresent && writeUdc) {
                         steady_clock::time_point temp = steady_clock::now();

                         if (std::chrono::duration_cast<microseconds>(temp - disconnect).count() <
                             kPullUpDelay)
                             usleep(kPullUpDelay);

                         if (!!WriteStringToFile(monitorFfs->mGadgetName, PULLUP_PATH)) {
                             lock_guard<mutex> lock(monitorFfs->mLock);
                             monitorFfs->mCurrentUsbFunctionsApplied = true;
                             monitorFfs->mCallback(monitorFfs->mCurrentUsbFunctionsApplied,
                                                   monitorFfs->mPayload);
                             ALOGI("GADGET pulled up");
                             writeUdc = false;
                             gadgetPullup = true;
                             // notify the main thread to signal userspace.
                             monitorFfs->mCv.notify_all();
                         }
                     }
                 }
             } else {
                 uint64_t flag;
                 read(monitorFfs->mEventFd, &flag, sizeof(flag));
                 if (flag == 100) {
                     stopMonitor = true;
                     break;
                 }
             }
         }
     }
     return NULL;
 }

 void MonitorFfs::reset() {
     lock_guard<mutex> lock(mLockFd);
     uint64_t flag = 100;
     unsigned long ret;

     if (mMonitorRunning) {
         // Stop the monitor thread by writing into signal fd.
         ret = TEMP_FAILURE_RETRY(write(mEventFd, &flag, sizeof(flag)));
         if (ret < 0) ALOGE("Error writing eventfd errno=%d", errno);

         ALOGI("mMonitor signalled to exit");
         mMonitor->join();
         ALOGI("mMonitor destroyed");
         mMonitorRunning = false;
     }

     for (std::vector<int>::size_type i = 0; i != mWatchFd.size(); i++)
         inotify_rm_watch(mInotifyFd, mWatchFd[i]);

     mEndpointList.clear();
     gadgetPullup = false;
     mCallback = NULL;
     mPayload = NULL;
 }

 bool MonitorFfs::startMonitor() {
     mMonitor = unique_ptr<thread>(new thread(this->startMonitorFd, this));
     mMonitorRunning = true;
     return true;
 }

 bool MonitorFfs::isMonitorRunning() {
     return mMonitorRunning;
 }

 bool MonitorFfs::waitForPullUp(int timeout_ms) {
     std::unique_lock<std::mutex> lk(mLock);

     if (gadgetPullup) return true;

     if (mCv.wait_for(lk, timeout_ms * 1ms, [] { return gadgetPullup; })) {
         ALOGI("monitorFfs signalled true");
         return true;
     } else {
         ALOGI("monitorFfs signalled error");
         // continue monitoring as the descriptors might be written at a later
         // point.
         return false;
     }
 }

 bool MonitorFfs::addInotifyFd(string fd) {
     lock_guard<mutex> lock(mLockFd);
     int wfd;

     wfd = inotify_add_watch(mInotifyFd, fd.c_str(), IN_ALL_EVENTS);
     if (wfd == -1)
         return false;
     else
         mWatchFd.push_back(wfd);

     return true;
 }

 void MonitorFfs::addEndPoint(string ep) {
     lock_guard<mutex> lock(mLockFd);

     mEndpointList.push_back(ep);
 }

 void MonitorFfs::registerFunctionsAppliedCallback(void (*callback)(bool functionsApplied,
                                                                    void* payload),
                                                   void* payload) {
     mCallback = callback;
     mPayload = payload;
 }

 }  // namespace gadget
 }  // namespace usb
 }  // namespace hardware
 }  // namespace android
	/*
	* Copyright (C) 2020 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.
	*/

	#define LOG_TAG "libusbconfigfs"

	#include "include/UsbGadgetCommon.h"

	namespace android {
	namespace hardware {
	namespace usb {
	namespace gadget {

	static volatile bool gadgetPullup;

	MonitorFfs::MonitorFfs(const char* const gadget)
	: mWatchFd(),
	mEndpointList(),
	mLock(),
	mCv(),
	mLockFd(),
	mCurrentUsbFunctionsApplied(false),
	mMonitor(),
	mCallback(NULL),
	mPayload(NULL),
	mGadgetName(gadget),
	mMonitorRunning(false) {
	unique_fd eventFd(eventfd(0, 0));
	if (eventFd == -1) {
	ALOGE("mEventFd failed to create %d", errno);
	abort();
	}

	unique_fd epollFd(epoll_create(2));
	if (epollFd == -1) {
	ALOGE("mEpollFd failed to create %d", errno);
	abort();
	}

	unique_fd inotifyFd(inotify_init());
	if (inotifyFd < 0) {
	ALOGE("inotify init failed");
	abort();
	}

	if (addEpollFd(epollFd, inotifyFd) == -1) abort();

	if (addEpollFd(epollFd, eventFd) == -1) abort();

	mEpollFd = move(epollFd);
	mInotifyFd = move(inotifyFd);
	mEventFd = move(eventFd);
	gadgetPullup = false;
	}

	static void displayInotifyEvent(struct inotify_event* i) {
	ALOGE(" wd =%2d; ", i->wd);
	if (i->cookie > 0) ALOGE("cookie =%4d; ", i->cookie);

	ALOGE("mask = ");
	if (i->mask & IN_ACCESS) ALOGE("IN_ACCESS ");
	if (i->mask & IN_ATTRIB) ALOGE("IN_ATTRIB ");
	if (i->mask & IN_CLOSE_NOWRITE) ALOGE("IN_CLOSE_NOWRITE ");
	if (i->mask & IN_CLOSE_WRITE) ALOGE("IN_CLOSE_WRITE ");
	if (i->mask & IN_CREATE) ALOGE("IN_CREATE ");
	if (i->mask & IN_DELETE) ALOGE("IN_DELETE ");
	if (i->mask & IN_DELETE_SELF) ALOGE("IN_DELETE_SELF ");
	if (i->mask & IN_IGNORED) ALOGE("IN_IGNORED ");
	if (i->mask & IN_ISDIR) ALOGE("IN_ISDIR ");
	if (i->mask & IN_MODIFY) ALOGE("IN_MODIFY ");
	if (i->mask & IN_MOVE_SELF) ALOGE("IN_MOVE_SELF ");
	if (i->mask & IN_MOVED_FROM) ALOGE("IN_MOVED_FROM ");
	if (i->mask & IN_MOVED_TO) ALOGE("IN_MOVED_TO ");
	if (i->mask & IN_OPEN) ALOGE("IN_OPEN ");
	if (i->mask & IN_Q_OVERFLOW) ALOGE("IN_Q_OVERFLOW ");
	if (i->mask & IN_UNMOUNT) ALOGE("IN_UNMOUNT ");
	ALOGE("\n");

	if (i->len > 0) ALOGE(" name = %s\n", i->name);
	}

	void* MonitorFfs::startMonitorFd(void* param) {
	MonitorFfs* monitorFfs = (MonitorFfs*)param;
	char buf[kBufferSize];
	bool writeUdc = true, stopMonitor = false;
	struct epoll_event events[kEpollEvents];
	steady_clock::time_point disconnect;

	bool descriptorWritten = true;
	for (int i = 0; i < static_cast<int>(monitorFfs->mEndpointList.size()); i++) {
	if (access(monitorFfs->mEndpointList.at(i).c_str(), R_OK)) {
	descriptorWritten = false;
	break;
	}
	}

	// notify here if the endpoints are already present.
	if (descriptorWritten) {
	usleep(kPullUpDelay);
	if (!!WriteStringToFile(monitorFfs->mGadgetName, PULLUP_PATH)) {
	lock_guard<mutex> lock(monitorFfs->mLock);
	monitorFfs->mCurrentUsbFunctionsApplied = true;
	monitorFfs->mCallback(monitorFfs->mCurrentUsbFunctionsApplied, monitorFfs->mPayload);
	gadgetPullup = true;
	writeUdc = false;
	ALOGI("GADGET pulled up");
	monitorFfs->mCv.notify_all();
	}
	}

	while (!stopMonitor) {
	int nrEvents = epoll_wait(monitorFfs->mEpollFd, events, kEpollEvents, -1);

	if (nrEvents <= 0) {
	ALOGE("epoll wait did not return descriptor number");
	continue;
	}

	for (int i = 0; i < nrEvents; i++) {
	ALOGI("event=%u on fd=%d\n", events[i].events, events[i].data.fd);

	if (events[i].data.fd == monitorFfs->mInotifyFd) {
	// Process all of the events in buffer returned by read().
	int numRead = read(monitorFfs->mInotifyFd, buf, kBufferSize);
	for (char* p = buf; p < buf + numRead;) {
	struct inotify_event* event = (struct inotify_event*)p;
	if (kDebug) displayInotifyEvent(event);

	p += sizeof(struct inotify_event) + event->len;

	bool descriptorPresent = true;
	for (int j = 0; j < static_cast<int>(monitorFfs->mEndpointList.size()); j++) {
	if (access(monitorFfs->mEndpointList.at(j).c_str(), R_OK)) {
	if (kDebug) ALOGI("%s absent", monitorFfs->mEndpointList.at(j).c_str());
	descriptorPresent = false;
	break;
	}
	}

	if (!descriptorPresent && !writeUdc) {
	if (kDebug) ALOGI("endpoints not up");
	writeUdc = true;
	disconnect = std::chrono::steady_clock::now();
	} else if (descriptorPresent && writeUdc) {
	steady_clock::time_point temp = steady_clock::now();

	if (std::chrono::duration_cast<microseconds>(temp - disconnect).count() <
	kPullUpDelay)
	usleep(kPullUpDelay);

	if (!!WriteStringToFile(monitorFfs->mGadgetName, PULLUP_PATH)) {
	lock_guard<mutex> lock(monitorFfs->mLock);
	monitorFfs->mCurrentUsbFunctionsApplied = true;
	monitorFfs->mCallback(monitorFfs->mCurrentUsbFunctionsApplied,
	monitorFfs->mPayload);
	ALOGI("GADGET pulled up");
	writeUdc = false;
	gadgetPullup = true;
	// notify the main thread to signal userspace.
	monitorFfs->mCv.notify_all();
	}
	}
	}
	} else {
	uint64_t flag;
	read(monitorFfs->mEventFd, &flag, sizeof(flag));
	if (flag == 100) {
	stopMonitor = true;
	break;
	}
	}
	}
	}
	return NULL;
	}

	void MonitorFfs::reset() {
	lock_guard<mutex> lock(mLockFd);
	uint64_t flag = 100;
	unsigned long ret;

	if (mMonitorRunning) {
	// Stop the monitor thread by writing into signal fd.
	ret = TEMP_FAILURE_RETRY(write(mEventFd, &flag, sizeof(flag)));
	if (ret < 0) ALOGE("Error writing eventfd errno=%d", errno);

	ALOGI("mMonitor signalled to exit");
	mMonitor->join();
	ALOGI("mMonitor destroyed");
	mMonitorRunning = false;
	}

	for (std::vector<int>::size_type i = 0; i != mWatchFd.size(); i++)
	inotify_rm_watch(mInotifyFd, mWatchFd[i]);

	mEndpointList.clear();
	gadgetPullup = false;
	mCallback = NULL;
	mPayload = NULL;
	}

	bool MonitorFfs::startMonitor() {
	mMonitor = unique_ptr<thread>(new thread(this->startMonitorFd, this));
	mMonitorRunning = true;
	return true;
	}

	bool MonitorFfs::isMonitorRunning() {
	return mMonitorRunning;
	}

	bool MonitorFfs::waitForPullUp(int timeout_ms) {
	std::unique_lock<std::mutex> lk(mLock);

	if (gadgetPullup) return true;

	if (mCv.wait_for(lk, timeout_ms * 1ms, [] { return gadgetPullup; })) {
	ALOGI("monitorFfs signalled true");
	return true;
	} else {
	ALOGI("monitorFfs signalled error");
	// continue monitoring as the descriptors might be written at a later
	// point.
	return false;
	}
	}

	bool MonitorFfs::addInotifyFd(string fd) {
	lock_guard<mutex> lock(mLockFd);
	int wfd;

	wfd = inotify_add_watch(mInotifyFd, fd.c_str(), IN_ALL_EVENTS);
	if (wfd == -1)
	return false;
	else
	mWatchFd.push_back(wfd);

	return true;
	}

	void MonitorFfs::addEndPoint(string ep) {
	lock_guard<mutex> lock(mLockFd);

	mEndpointList.push_back(ep);
	}

	void MonitorFfs::registerFunctionsAppliedCallback(void (*callback)(bool functionsApplied,
	void* payload),
	void* payload) {
	mCallback = callback;
	mPayload = payload;
	}

	} // namespace gadget
	} // namespace usb
	} // namespace hardware
	} // namespace android