contexthubhal/nanohubhal.cpp - device/google/contexthub - Git at Google

 /*
  * Copyright (C) 2016 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 "NanohubHAL"

 #include <fcntl.h>
 #include <poll.h>
 #include <pthread.h>
 #include <unistd.h>
 #include <sys/inotify.h>
 #include <sys/types.h>
 #include <sys/stat.h>

 #include <hardware/context_hub.h>
 #include <hardware/hardware.h>

 #include <utils/Log.h>
 #include <cutils/properties.h>

 #include <cinttypes>
 #include <iomanip>
 #include <sstream>

 #include "nanohub_perdevice.h"
 #include "system_comms.h"
 #include "nanohubhal.h"

 #define NANOHUB_LOCK_DIR        "/data/system/nanohub_lock"
 #define NANOHUB_LOCK_FILE       NANOHUB_LOCK_DIR "/lock"
 #define NANOHUB_LOCK_DIR_PERMS  (S_IRUSR | S_IWUSR | S_IXUSR)

 namespace android {

 namespace nanohub {

 inline std::ostream &operator << (std::ostream &os, const hub_app_name_t &appId)
 {
     char vendor[6];
     __be64 beAppId = htobe64(appId.id);
     uint32_t seqId = appId.id & NANOAPP_VENDOR_ALL_APPS;

     std::ios::fmtflags f(os.flags());
     memcpy(vendor, (void*)&beAppId, sizeof(vendor) - 1);
     vendor[sizeof(vendor) - 1] = 0;
     if (strlen(vendor) == 5)
         os << vendor << ", " << std::hex << std::setw(6)  << seqId;
     else
         os << "#" << std::hex << appId.id;
     os.flags(f);

     return os;
 }

 void dumpBuffer(const char *pfx, const hub_app_name_t &appId, uint32_t evtId, const void *data, size_t len, int status)
 {
     std::ostringstream os;
     const uint8_t *p = static_cast<const uint8_t *>(data);
     os << pfx << ": [ID=" << appId << "; SZ=" << std::dec << len;
     if (evtId)
         os << "; EVT=" << std::hex << evtId;
     os << "]:" << std::hex;
     for (size_t i = 0; i < len; ++i) {
         os << " "  << std::setfill('0') << std::setw(2) << (unsigned int)p[i];
     }
     if (status) {
         os << "; status=" << status << " [" << std::setfill('0') << std::setw(8) << status << "]";
     }
     ALOGI("%s", os.str().c_str());
 }

 static int rwrite(int fd, const void *buf, int len)
 {
     int ret;

     do {
         ret = write(fd, buf, len);
     } while (ret < 0 && errno == EINTR);

     if (ret != len) {
         return errno ? -errno : -EIO;
     }

     return 0;
 }

 static int rread(int fd, void *buf, int len)
 {
     int ret;

     do {
         ret = read(fd, buf, len);
     } while (ret < 0 && errno == EINTR);

     return ret;
 }

 static bool init_inotify(pollfd *pfd) {
     bool success = false;

     mkdir(NANOHUB_LOCK_DIR, NANOHUB_LOCK_DIR_PERMS);
     pfd->fd = inotify_init1(IN_NONBLOCK);
     if (pfd->fd < 0) {
         ALOGE("Couldn't initialize inotify: %s", strerror(errno));
     } else if (inotify_add_watch(pfd->fd, NANOHUB_LOCK_DIR, IN_CREATE | IN_DELETE) < 0) {
         ALOGE("Couldn't add inotify watch: %s", strerror(errno));
         close(pfd->fd);
     } else {
         pfd->events = POLLIN;
         success = true;
     }

     return success;
 }

 static void discard_inotify_evt(pollfd &pfd) {
     if ((pfd.revents & POLLIN)) {
         char buf[sizeof(inotify_event) + NAME_MAX + 1];
         int ret = read(pfd.fd, buf, sizeof(buf));
         ALOGD("Discarded %d bytes of inotify data", ret);
     }
 }

 static void wait_on_dev_lock(pollfd &pfd) {
     // While the lock file exists, poll on the inotify fd (with timeout)
     discard_inotify_evt(pfd);
     while (access(NANOHUB_LOCK_FILE, F_OK) == 0) {
         ALOGW("Nanohub is locked; blocking read thread");
         int ret = poll(&pfd, 1, 5000);
         if (ret > 0) {
             discard_inotify_evt(pfd);
         }
     }
 }

 int NanoHub::doSendToDevice(const hub_app_name_t *name, const void *data, uint32_t len)
 {
     if (len > MAX_RX_PACKET) {
         return -EINVAL;
     }

     nano_message msg = {
         .hdr = {
             .event_id = APP_FROM_HOST_EVENT_ID,
             .app_name = *name,
             .len = static_cast<uint8_t>(len),
         },
     };

     memcpy(&msg.data[0], data, len);

     return rwrite(mFd, &msg, len + sizeof(msg.hdr));
 }

 void NanoHub::doSendToApp(const hub_app_name_t *name, uint32_t typ, const void *data, uint32_t len)
 {
     hub_message_t msg = {
         .app_name = *name,
         .message_type = typ,
         .message_len = len,
         .message = data,
     };

     mMsgCbkFunc(0, &msg, mMsgCbkData);
 }

 void* NanoHub::run(void *data)
 {
     NanoHub *self = static_cast<NanoHub*>(data);
     return self->doRun();
 }

 void* NanoHub::doRun()
 {
     enum {
         IDX_NANOHUB,
         IDX_CLOSE_PIPE,
         IDX_INOTIFY
     };
     pollfd myFds[3] = {
         [IDX_NANOHUB] = { .fd = mFd, .events = POLLIN, },
         [IDX_CLOSE_PIPE] = { .fd = mThreadClosingPipe[0], .events = POLLIN, },
     };
     pollfd &inotifyFd = myFds[IDX_INOTIFY];
     bool hasInotify = false;
     int numPollFds = 2;

     if (init_inotify(&inotifyFd)) {
         numPollFds++;
         hasInotify = true;
     }

     setDebugFlags(property_get_int32("persist.nanohub.debug", 0));

     while (1) {
         int ret = poll(myFds, numPollFds, -1);
         if (ret <= 0) {
             ALOGD("poll returned with an error: %s", strerror(errno));
             continue;
         }

         if (hasInotify) {
             wait_on_dev_lock(inotifyFd);
         }

         if (myFds[IDX_NANOHUB].revents & POLLIN) { // we have data

             nano_message msg;

             ret = rread(mFd, &msg, sizeof(msg));
             if (ret <= 0) {
                 ALOGE("read failed with %d", ret);
                 break;
             }
             if (ret < (int)sizeof(msg.hdr)) {
                 ALOGE("Only read %d bytes", ret);
                 break;
             }

             uint32_t len = msg.hdr.len;

             if (len > sizeof(msg.data)) {
                 ALOGE("malformed packet with len %" PRIu32, len);
                 break;
             }

             if (ret != (int)(sizeof(msg.hdr) + len)) {
                 ALOGE("Expected %zu bytes, read %d bytes", sizeof(msg.hdr) + len, ret);
                 break;
             }

             ret = SystemComm::handleRx(&msg);
             if (ret < 0) {
                 ALOGE("SystemComm::handleRx() returned %d", ret);
             } else if (ret) {
                 if (messageTracingEnabled()) {
                     dumpBuffer("DEV -> APP", msg.hdr.app_name, msg.hdr.event_id, &msg.data[0], msg.hdr.len);
                 }
                 doSendToApp(&msg.hdr.app_name, msg.hdr.event_id, &msg.data[0], msg.hdr.len);
             }
         }

         if (myFds[IDX_CLOSE_PIPE].revents & POLLIN) { // we have been asked to die
             ALOGD("thread exiting");
             break;
         }
     }

     close(mFd);
     return NULL;
 }

 int NanoHub::openHub()
 {
     int ret = 0;

     mFd = open(get_devnode_path(), O_RDWR);
     if (mFd < 0) {
         ALOGE("cannot find hub devnode '%s'", get_devnode_path());
         ret = -errno;
         goto fail_open;
     }

     if (pipe(mThreadClosingPipe)) {
         ALOGE("failed to create signal pipe");
         ret = -errno;
         goto fail_pipe;
     }

     if (pthread_create(&mWorkerThread, NULL, &NanoHub::run, this)) {
         ALOGE("failed to spawn worker thread");
         ret = -errno;
         goto fail_thread;
     }

     return 0;

 fail_thread:
     close(mThreadClosingPipe[0]);
     close(mThreadClosingPipe[1]);

 fail_pipe:
     close(mFd);

 fail_open:
     return ret;
 }

 int NanoHub::closeHub(void)
 {
     char zero = 0;

     //signal
     while(write(mThreadClosingPipe[1], &zero, 1) != 1);

     //wait
     (void)pthread_join(mWorkerThread, NULL);

     //cleanup
     ::close(mThreadClosingPipe[0]);
     ::close(mThreadClosingPipe[1]);

     reset();

     return 0;
 }

 int NanoHub::doSubscribeMessages(uint32_t hub_id, context_hub_callback *cbk, void *cookie)
 {
     if (hub_id) {
         return -ENODEV;
     }

     Mutex::Autolock _l(mLock);
     int ret = 0;

     if (!mMsgCbkFunc && !cbk) { //we're off and staying off - do nothing

         ALOGD("staying off");
     } else if (cbk && mMsgCbkFunc) { //new callback but staying on

         ALOGD("staying on");
     } else if (mMsgCbkFunc) {     //we were on but turning off

         ALOGD("turning off");

         ret = closeHub();
     } else if (cbk) {             //we're turning on

         ALOGD("turning on");
         ret = openHub();
     }

     mMsgCbkFunc = cbk;
     mMsgCbkData = cookie;

     return ret;
 }

 int NanoHub::doSendToNanohub(uint32_t hub_id, const hub_message_t *msg)
 {
     if (hub_id) {
         return -ENODEV;
     }

     int ret = 0;
     Mutex::Autolock _l(mLock);

     if (!mMsgCbkFunc) {
         ALOGW("refusing to send a message when nobody around to get a reply!");
         ret = -EIO;
     } else {
         if (!msg || !msg->message) {
             ALOGW("not sending invalid message 1");
             ret = -EINVAL;
         } else if (get_hub_info()->os_app_name == msg->app_name) {
             //messages to the "system" app are special - hal handles them
             if (messageTracingEnabled()) {
                 dumpBuffer("APP -> HAL", msg->app_name, msg->message_type, msg->message, msg->message_len);
             }
             ret = SystemComm::handleTx(msg);
         } else if (msg->message_type || msg->message_len > MAX_RX_PACKET) {
             ALOGW("not sending invalid message 2");
             ret = -EINVAL;
         } else {
             if (messageTracingEnabled()) {
                 dumpBuffer("APP -> DEV", msg->app_name, 0, msg->message, msg->message_len);
             }
             ret = doSendToDevice(&msg->app_name, msg->message, msg->message_len);
         }
     }

     return ret;
 }

 static int hal_get_hubs(context_hub_module_t*, const context_hub_t ** list)
 {
     *list = get_hub_info();

     return 1; /* we have one hub */
 }

 }; // namespace nanohub

 }; // namespace android

 context_hub_module_t HAL_MODULE_INFO_SYM = {
     .common = {
         .tag = HARDWARE_MODULE_TAG,
         .module_api_version = CONTEXT_HUB_DEVICE_API_VERSION_1_0,
         .hal_api_version = HARDWARE_HAL_API_VERSION,
         .id = CONTEXT_HUB_MODULE_ID,
         .name = "Nanohub HAL",
         .author = "Google",
     },

     .get_hubs = android::nanohub::hal_get_hubs,
     .subscribe_messages = android::nanohub::NanoHub::subscribeMessages,
     .send_message = android::nanohub::NanoHub::sendToNanohub,
 };
	/*
	* Copyright (C) 2016 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 "NanohubHAL"

	#include <fcntl.h>
	#include <poll.h>
	#include <pthread.h>
	#include <unistd.h>
	#include <sys/inotify.h>
	#include <sys/types.h>
	#include <sys/stat.h>

	#include <hardware/context_hub.h>
	#include <hardware/hardware.h>

	#include <utils/Log.h>
	#include <cutils/properties.h>

	#include <cinttypes>
	#include <iomanip>
	#include <sstream>

	#include "nanohub_perdevice.h"
	#include "system_comms.h"
	#include "nanohubhal.h"

	#define NANOHUB_LOCK_DIR "/data/system/nanohub_lock"
	#define NANOHUB_LOCK_FILE NANOHUB_LOCK_DIR "/lock"
	#define NANOHUB_LOCK_DIR_PERMS (S_IRUSR \| S_IWUSR \| S_IXUSR)

	namespace android {

	namespace nanohub {

	inline std::ostream &operator << (std::ostream &os, const hub_app_name_t &appId)
	{
	char vendor[6];
	__be64 beAppId = htobe64(appId.id);
	uint32_t seqId = appId.id & NANOAPP_VENDOR_ALL_APPS;

	std::ios::fmtflags f(os.flags());
	memcpy(vendor, (void*)&beAppId, sizeof(vendor) - 1);
	vendor[sizeof(vendor) - 1] = 0;
	if (strlen(vendor) == 5)
	os << vendor << ", " << std::hex << std::setw(6) << seqId;
	else
	os << "#" << std::hex << appId.id;
	os.flags(f);

	return os;
	}

	void dumpBuffer(const char pfx, const hub_app_name_t &appId, uint32_t evtId, const void data, size_t len, int status)
	{
	std::ostringstream os;
	const uint8_t p = static_cast<const uint8_t >(data);
	os << pfx << ": [ID=" << appId << "; SZ=" << std::dec << len;
	if (evtId)
	os << "; EVT=" << std::hex << evtId;
	os << "]:" << std::hex;
	for (size_t i = 0; i < len; ++i) {
	os << " " << std::setfill('0') << std::setw(2) << (unsigned int)p[i];
	}
	if (status) {
	os << "; status=" << status << " [" << std::setfill('0') << std::setw(8) << status << "]";
	}
	ALOGI("%s", os.str().c_str());
	}

	static int rwrite(int fd, const void *buf, int len)
	{
	int ret;

	do {
	ret = write(fd, buf, len);
	} while (ret < 0 && errno == EINTR);

	if (ret != len) {
	return errno ? -errno : -EIO;
	}

	return 0;
	}

	static int rread(int fd, void *buf, int len)
	{
	int ret;

	do {
	ret = read(fd, buf, len);
	} while (ret < 0 && errno == EINTR);

	return ret;
	}

	static bool init_inotify(pollfd *pfd) {
	bool success = false;

	mkdir(NANOHUB_LOCK_DIR, NANOHUB_LOCK_DIR_PERMS);
	pfd->fd = inotify_init1(IN_NONBLOCK);
	if (pfd->fd < 0) {
	ALOGE("Couldn't initialize inotify: %s", strerror(errno));
	} else if (inotify_add_watch(pfd->fd, NANOHUB_LOCK_DIR, IN_CREATE \| IN_DELETE) < 0) {
	ALOGE("Couldn't add inotify watch: %s", strerror(errno));
	close(pfd->fd);
	} else {
	pfd->events = POLLIN;
	success = true;
	}

	return success;
	}

	static void discard_inotify_evt(pollfd &pfd) {
	if ((pfd.revents & POLLIN)) {
	char buf[sizeof(inotify_event) + NAME_MAX + 1];
	int ret = read(pfd.fd, buf, sizeof(buf));
	ALOGD("Discarded %d bytes of inotify data", ret);
	}
	}

	static void wait_on_dev_lock(pollfd &pfd) {
	// While the lock file exists, poll on the inotify fd (with timeout)
	discard_inotify_evt(pfd);
	while (access(NANOHUB_LOCK_FILE, F_OK) == 0) {
	ALOGW("Nanohub is locked; blocking read thread");
	int ret = poll(&pfd, 1, 5000);
	if (ret > 0) {
	discard_inotify_evt(pfd);
	}
	}
	}

	int NanoHub::doSendToDevice(const hub_app_name_t name, const void data, uint32_t len)
	{
	if (len > MAX_RX_PACKET) {
	return -EINVAL;
	}

	nano_message msg = {
	.hdr = {
	.event_id = APP_FROM_HOST_EVENT_ID,
	.app_name = *name,
	.len = static_cast<uint8_t>(len),
	},
	};

	memcpy(&msg.data[0], data, len);

	return rwrite(mFd, &msg, len + sizeof(msg.hdr));
	}

	void NanoHub::doSendToApp(const hub_app_name_t name, uint32_t typ, const void data, uint32_t len)
	{
	hub_message_t msg = {
	.app_name = *name,
	.message_type = typ,
	.message_len = len,
	.message = data,
	};

	mMsgCbkFunc(0, &msg, mMsgCbkData);
	}

	void* NanoHub::run(void *data)
	{
	NanoHub self = static_cast<NanoHub>(data);
	return self->doRun();
	}

	void* NanoHub::doRun()
	{
	enum {
	IDX_NANOHUB,
	IDX_CLOSE_PIPE,
	IDX_INOTIFY
	};
	pollfd myFds[3] = {
	[IDX_NANOHUB] = { .fd = mFd, .events = POLLIN, },
	[IDX_CLOSE_PIPE] = { .fd = mThreadClosingPipe[0], .events = POLLIN, },
	};
	pollfd &inotifyFd = myFds[IDX_INOTIFY];
	bool hasInotify = false;
	int numPollFds = 2;

	if (init_inotify(&inotifyFd)) {
	numPollFds++;
	hasInotify = true;
	}

	setDebugFlags(property_get_int32("persist.nanohub.debug", 0));

	while (1) {
	int ret = poll(myFds, numPollFds, -1);
	if (ret <= 0) {
	ALOGD("poll returned with an error: %s", strerror(errno));
	continue;
	}

	if (hasInotify) {
	wait_on_dev_lock(inotifyFd);
	}

	if (myFds[IDX_NANOHUB].revents & POLLIN) { // we have data

	nano_message msg;

	ret = rread(mFd, &msg, sizeof(msg));
	if (ret <= 0) {
	ALOGE("read failed with %d", ret);
	break;
	}
	if (ret < (int)sizeof(msg.hdr)) {
	ALOGE("Only read %d bytes", ret);
	break;
	}

	uint32_t len = msg.hdr.len;

	if (len > sizeof(msg.data)) {
	ALOGE("malformed packet with len %" PRIu32, len);
	break;
	}

	if (ret != (int)(sizeof(msg.hdr) + len)) {
	ALOGE("Expected %zu bytes, read %d bytes", sizeof(msg.hdr) + len, ret);
	break;
	}

	ret = SystemComm::handleRx(&msg);
	if (ret < 0) {
	ALOGE("SystemComm::handleRx() returned %d", ret);
	} else if (ret) {
	if (messageTracingEnabled()) {
	dumpBuffer("DEV -> APP", msg.hdr.app_name, msg.hdr.event_id, &msg.data[0], msg.hdr.len);
	}
	doSendToApp(&msg.hdr.app_name, msg.hdr.event_id, &msg.data[0], msg.hdr.len);
	}
	}

	if (myFds[IDX_CLOSE_PIPE].revents & POLLIN) { // we have been asked to die
	ALOGD("thread exiting");
	break;
	}
	}

	close(mFd);
	return NULL;
	}

	int NanoHub::openHub()
	{
	int ret = 0;

	mFd = open(get_devnode_path(), O_RDWR);
	if (mFd < 0) {
	ALOGE("cannot find hub devnode '%s'", get_devnode_path());
	ret = -errno;
	goto fail_open;
	}

	if (pipe(mThreadClosingPipe)) {
	ALOGE("failed to create signal pipe");
	ret = -errno;
	goto fail_pipe;
	}

	if (pthread_create(&mWorkerThread, NULL, &NanoHub::run, this)) {
	ALOGE("failed to spawn worker thread");
	ret = -errno;
	goto fail_thread;
	}

	return 0;

	fail_thread:
	close(mThreadClosingPipe[0]);
	close(mThreadClosingPipe[1]);

	fail_pipe:
	close(mFd);

	fail_open:
	return ret;
	}

	int NanoHub::closeHub(void)
	{
	char zero = 0;

	//signal
	while(write(mThreadClosingPipe[1], &zero, 1) != 1);

	//wait
	(void)pthread_join(mWorkerThread, NULL);

	//cleanup
	::close(mThreadClosingPipe[0]);
	::close(mThreadClosingPipe[1]);

	reset();

	return 0;
	}

	int NanoHub::doSubscribeMessages(uint32_t hub_id, context_hub_callback cbk, void cookie)
	{
	if (hub_id) {
	return -ENODEV;
	}

	Mutex::Autolock _l(mLock);
	int ret = 0;

	if (!mMsgCbkFunc && !cbk) { //we're off and staying off - do nothing

	ALOGD("staying off");
	} else if (cbk && mMsgCbkFunc) { //new callback but staying on

	ALOGD("staying on");
	} else if (mMsgCbkFunc) { //we were on but turning off

	ALOGD("turning off");

	ret = closeHub();
	} else if (cbk) { //we're turning on

	ALOGD("turning on");
	ret = openHub();
	}

	mMsgCbkFunc = cbk;
	mMsgCbkData = cookie;

	return ret;
	}

	int NanoHub::doSendToNanohub(uint32_t hub_id, const hub_message_t *msg)
	{
	if (hub_id) {
	return -ENODEV;
	}

	int ret = 0;
	Mutex::Autolock _l(mLock);

	if (!mMsgCbkFunc) {
	ALOGW("refusing to send a message when nobody around to get a reply!");
	ret = -EIO;
	} else {
	if (!msg \|\| !msg->message) {
	ALOGW("not sending invalid message 1");
	ret = -EINVAL;
	} else if (get_hub_info()->os_app_name == msg->app_name) {
	//messages to the "system" app are special - hal handles them
	if (messageTracingEnabled()) {
	dumpBuffer("APP -> HAL", msg->app_name, msg->message_type, msg->message, msg->message_len);
	}
	ret = SystemComm::handleTx(msg);
	} else if (msg->message_type \|\| msg->message_len > MAX_RX_PACKET) {
	ALOGW("not sending invalid message 2");
	ret = -EINVAL;
	} else {
	if (messageTracingEnabled()) {
	dumpBuffer("APP -> DEV", msg->app_name, 0, msg->message, msg->message_len);
	}
	ret = doSendToDevice(&msg->app_name, msg->message, msg->message_len);
	}
	}

	return ret;
	}

	static int hal_get_hubs(context_hub_module_t, const context_hub_t * list)
	{
	*list = get_hub_info();

	return 1; /* we have one hub */
	}

	}; // namespace nanohub

	}; // namespace android

	context_hub_module_t HAL_MODULE_INFO_SYM = {
	.common = {
	.tag = HARDWARE_MODULE_TAG,
	.module_api_version = CONTEXT_HUB_DEVICE_API_VERSION_1_0,
	.hal_api_version = HARDWARE_HAL_API_VERSION,
	.id = CONTEXT_HUB_MODULE_ID,
	.name = "Nanohub HAL",
	.author = "Google",
	},

	.get_hubs = android::nanohub::hal_get_hubs,
	.subscribe_messages = android::nanohub::NanoHub::subscribeMessages,
	.send_message = android::nanohub::NanoHub::sendToNanohub,
	};