[AOA FFS Implementation] Add Vendor Control Request Monitor (f73343a5) · Commits · e / os / android_frameworks_base

services/core/jni/com_android_server_UsbDeviceManager.cpp

+186 −1

Original line number	Diff line number	Diff line
		@@ -32,12 +32,12 @@

		#include "MtpDescriptors.h"
		#include "android_runtime/AndroidRuntime.h"
		#include "android_runtime/Log.h"
		#include "jni.h"
		#include "utils/Log.h"

		#define DRIVER_NAME "/dev/usb_accessory"
		#define EPOLL_MAX_EVENTS 4
		#define FFS_NUM_EVENTS 5
		#define USB_STATE_MAX_LEN 20

		namespace android
		@@ -177,6 +177,191 @@ public:
		};
		static std::unique_ptr<NativeGadgetMonitorThread> sGadgetMonitorThread;

		/*
		* NativeVendorControlRequestMonitorThread starts a new thread to monitor vendor
		* control requests. It issues state changes for accessory mode as required.
		*/
		class NativeVendorControlRequestMonitorThread {
		android::base::unique_fd mMonitorFd;
		int mShutdownPipefd[2];
		std::thread mThread;
		jobject mCallbackObj;

		void handleControlRequest(int fd, const struct usb_ctrlrequest *setup) {
		JNIEnv *env = AndroidRuntime::getJNIEnv();

		uint8_t type = setup->bRequestType;
		uint8_t code = setup->bRequest;
		uint16_t length = setup->wLength;
		uint16_t index = setup->wIndex;
		uint16_t value = setup->wValue;
		std::vector<char> buf;
		buf.resize(length + 1);
		std::string accessoryControlState;

		if ((type & USB_TYPE_MASK) == USB_TYPE_VENDOR) {
		switch (code) {
		// TODO(b/421809234): - Add support for accessory mode requests.
		// TODO(b/421807206): - Add support for accessory HID requests.

		default:
		ALOGE("Unrecognized USB vendor request! %d", (int)code);
		goto fail;
		}
		} else {
		ALOGE("Unrecognized USB request type %d", (int)type);
		goto fail;
		}

		if (type & USB_DIR_IN) {
		if (::write(fd, buf.data(), length) != length) {
		ALOGE("Usb error ctrlreq write data");
		goto fail;
		}
		}

		return;
		fail:
		// stall control endpoint by applying opposite i/o
		if (type & USB_DIR_IN) {
		if (::read(fd, buf.data(), 0) != -1 \|\| errno != EL2HLT) {
		ALOGE("Couldn't halt ep0 on in request");
		}
		} else {
		if (::write(fd, buf.data(), 0) != -1 \|\| errno != EL2HLT) {
		ALOGE("Couldn't halt ep0 on out request");
		}
		}
		}

		void teardown() {
		// Add teardown for vendor control requests being handled.

		ALOGI("Vendor control request monitor teardown");
		}

		int setupEpoll(android::base::unique_fd &epollFd) {
		struct epoll_event ev;

		ev.data.fd = mMonitorFd.get();
		ev.events = EPOLLIN;
		if (epoll_ctl(epollFd.get(), EPOLL_CTL_ADD, mMonitorFd.get(), &ev) != 0) {
		ALOGE("epoll_ctl failed for ctrl request monitor fd; %s", strerror(errno));
		return errno;
		}

		ev.data.fd = mShutdownPipefd[0];
		ev.events = EPOLLIN;
		if (epoll_ctl(epollFd.get(), EPOLL_CTL_ADD, mShutdownPipefd[0], &ev) != 0) {
		ALOGE("epoll_ctl failed for ctrl request pipe fd; %s", strerror(errno));
		return errno;
		}

		return 0;
		}

		void monitorLoop() {
		android::base::unique_fd epollFd(epoll_create(EPOLL_MAX_EVENTS));
		std::vector<struct usb_functionfs_event> ffs_events(FFS_NUM_EVENTS);

		ALOGI("Monitoring vendor control requests...");

		if (epollFd.get() == -1) {
		ALOGE("Vendor control request monitor epoll_create failed; %s", strerror(errno));
		return;
		}

		if (setupEpoll(epollFd) != 0) {
		ALOGE("Vendor control request monitor setupEpoll failed!");
		return;
		}

		JNIEnv *env = nullptr;
		JavaVMAttachArgs aargs = {JNI_VERSION_1_4, "NativeVendorControlRequestMonitorThread",
		nullptr};
		if (gvm->AttachCurrentThread(&env, &aargs) != JNI_OK \|\| env == nullptr) {
		ALOGE("Couldn't attach thread");
		return;
		}

		struct epoll_event events[EPOLL_MAX_EVENTS];
		int nevents = 0;
		while (true) {
		nevents = epoll_wait(epollFd.get(), events, EPOLL_MAX_EVENTS, -1);

		if (nevents < 0) {
		if (errno != EINTR)
		ALOGE("Vendor control request monitor epoll_wait failed; %s", strerror(errno));
		continue;
		}

		for (int i = 0; i < nevents; ++i) {
		int fd = events[i].data.fd;
		if (fd == mShutdownPipefd[0]) {
		ALOGE("Vendor control request monitor loop exiting...");
		goto exit;
		} else if (fd == mMonitorFd.get()) {
		if (events[i].events & EPOLLIN) {
		struct usb_functionfs_event *event = ffs_events.data();
		int nbytes = TEMP_FAILURE_RETRY(
		::read(fd, event,
		ffs_events.size() * sizeof(usb_functionfs_event)));
		if (nbytes == -1) {
		ALOGE("error reading Usb control events");
		continue;
		}
		for (size_t n = nbytes / sizeof(*event); n; --n, ++event) {
		switch (event->type) {
		case FUNCTIONFS_SETUP:
		handleControlRequest(fd, &event->u.setup);
		break;
		case FUNCTIONFS_UNBIND:
		teardown();
		break;
		default:
		continue;
		}
		}
		}
		}
		}
		}

		exit:
		auto res = gvm->DetachCurrentThread();
		ALOGE("Detaching thread");
		ALOGE_IF(res != JNI_OK, "Couldn't detach thread");
		return;
		}

		void stop() {
		if (mThread.joinable()) {
		int c = 'q';
		write(mShutdownPipefd[1], &c, 1);
		mThread.join();
		}
		}

		DISALLOW_COPY_AND_ASSIGN(NativeVendorControlRequestMonitorThread);

		public:
		explicit NativeVendorControlRequestMonitorThread(jobject obj,
		android::base::unique_fd monitorFd)
		: mMonitorFd(std::move(monitorFd)){
		mCallbackObj = AndroidRuntime::getJNIEnv()->NewGlobalRef(obj);
		pipe(mShutdownPipefd);
		mThread = std::thread(&NativeVendorControlRequestMonitorThread::monitorLoop, this);
		}

		~NativeVendorControlRequestMonitorThread() {
		stop();
		close(mShutdownPipefd[0]);
		close(mShutdownPipefd[1]);
		AndroidRuntime::getJNIEnv()->DeleteGlobalRef(mCallbackObj);
		}
		};
		static std::unique_ptr<NativeVendorControlRequestMonitorThread> sVendorControlRequestMonitorThread;

		static void set_accessory_string(JNIEnv *env, int fd, int cmd, jobjectArray strArray, int index)
		{
		char buffer[256];