automotive/can/1.0/default/CanBus.cpp - platform/hardware/interfaces - Git at Google

 /*
  * Copyright (C) 2019 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 "CanBus.h"

 #include "CloseHandle.h"

 #include <android-base/logging.h>
 #include <libnetdevice/can.h>
 #include <libnetdevice/libnetdevice.h>
 #include <linux/can.h>
 #include <linux/can/error.h>
 #include <linux/can/raw.h>

 namespace android::hardware::automotive::can::V1_0::implementation {

 /** Whether to log sent/received packets. */
 static constexpr bool kSuperVerbose = false;

 Return<Result> CanBus::send(const CanMessage& message) {
     std::lock_guard<std::mutex> lck(mIsUpGuard);
     if (!mIsUp) return Result::INTERFACE_DOWN;

     if (UNLIKELY(kSuperVerbose)) {
         LOG(VERBOSE) << "Sending " << toString(message);
     }

     if (message.payload.size() > CAN_MAX_DLEN) return Result::PAYLOAD_TOO_LONG;

     struct canfd_frame frame = {};
     frame.can_id = message.id;
     if (message.isExtendedId) frame.can_id |= CAN_EFF_FLAG;
     if (message.remoteTransmissionRequest) frame.can_id |= CAN_RTR_FLAG;
     frame.len = message.payload.size();
     memcpy(frame.data, message.payload.data(), message.payload.size());

     if (!mSocket->send(frame)) return Result::TRANSMISSION_FAILURE;

     return Result::OK;
 }

 Return<void> CanBus::listen(const hidl_vec<CanMessageFilter>& filter,
                             const sp<ICanMessageListener>& listenerCb, listen_cb _hidl_cb) {
     std::lock_guard<std::mutex> lck(mIsUpGuard);

     if (listenerCb == nullptr) {
         _hidl_cb(Result::INVALID_ARGUMENTS, nullptr);
         return {};
     }
     if (!mIsUp) {
         _hidl_cb(Result::INTERFACE_DOWN, nullptr);
         return {};
     }

     std::lock_guard<std::mutex> lckListeners(mMsgListenersGuard);

     sp<CloseHandle> closeHandle = new CloseHandle([this, listenerCb]() {
         std::lock_guard<std::mutex> lck(mMsgListenersGuard);
         std::erase_if(mMsgListeners, [&](const auto& e) { return e.callback == listenerCb; });
     });
     mMsgListeners.emplace_back(CanMessageListener{listenerCb, filter, closeHandle});
     auto& listener = mMsgListeners.back();

     // fix message IDs to have all zeros on bits not covered by mask
     std::for_each(listener.filter.begin(), listener.filter.end(),
                   [](auto& rule) { rule.id &= rule.mask; });

     _hidl_cb(Result::OK, closeHandle);
     return {};
 }

 CanBus::CanBus() {}

 CanBus::CanBus(const std::string& ifname) : mIfname(ifname) {}

 CanBus::~CanBus() {
     std::lock_guard<std::mutex> lck(mIsUpGuard);
     CHECK(!mIsUp) << "Interface is still up while being destroyed";

     std::lock_guard<std::mutex> lckListeners(mMsgListenersGuard);
     CHECK(mMsgListeners.empty()) << "Listener list is not empty while interface is being destroyed";
 }

 void CanBus::setErrorCallback(ErrorCallback errcb) {
     CHECK(!mIsUp) << "Can't set error callback while interface is up";
     CHECK(mErrCb == nullptr) << "Error callback is already set";
     mErrCb = errcb;
     CHECK(!mIsUp) << "Can't set error callback while interface is up";
 }

 ICanController::Result CanBus::preUp() {
     return ICanController::Result::OK;
 }

 bool CanBus::postDown() {
     return true;
 }

 ICanController::Result CanBus::up() {
     std::lock_guard<std::mutex> lck(mIsUpGuard);

     if (mIsUp) {
         LOG(WARNING) << "Interface is already up";
         return ICanController::Result::INVALID_STATE;
     }

     const auto preResult = preUp();
     if (preResult != ICanController::Result::OK) return preResult;

     const auto isUp = netdevice::isUp(mIfname);
     if (!isUp.has_value()) {
         // preUp() should prepare the interface (either create or make sure it's there)
         LOG(ERROR) << "Interface " << mIfname << " didn't get prepared";
         return ICanController::Result::BAD_INTERFACE_ID;
     }

     if (!*isUp && !netdevice::up(mIfname)) {
         LOG(ERROR) << "Can't bring " << mIfname << " up";
         return ICanController::Result::UNKNOWN_ERROR;
     }
     mDownAfterUse = !*isUp;

     using namespace std::placeholders;
     CanSocket::ReadCallback rdcb = std::bind(&CanBus::onRead, this, _1, _2);
     CanSocket::ErrorCallback errcb = std::bind(&CanBus::onError, this, _1);
     mSocket = CanSocket::open(mIfname, rdcb, errcb);
     if (!mSocket) {
         if (mDownAfterUse) netdevice::down(mIfname);
         return ICanController::Result::UNKNOWN_ERROR;
     }

     mIsUp = true;
     return ICanController::Result::OK;
 }

 void CanBus::clearMsgListeners() {
     std::vector<wp<ICloseHandle>> listenersToClose;
     {
         std::lock_guard<std::mutex> lck(mMsgListenersGuard);
         std::transform(mMsgListeners.begin(), mMsgListeners.end(),
                        std::back_inserter(listenersToClose),
                        [](const auto& e) { return e.closeHandle; });
     }

     for (auto& weakListener : listenersToClose) {
         /* Between populating listenersToClose and calling close method here, some listeners might
          * have been already removed from the original mMsgListeners list (resulting in a dangling
          * weak pointer here). It's fine - we just want to clean them up. */
         auto listener = weakListener.promote();
         if (listener != nullptr) listener->close();
     }

     std::lock_guard<std::mutex> lck(mMsgListenersGuard);
     CHECK(mMsgListeners.empty()) << "Listeners list wasn't emptied";
 }

 void CanBus::clearErrListeners() {
     std::lock_guard<std::mutex> lck(mErrListenersGuard);
     mErrListeners.clear();
 }

 Return<sp<ICloseHandle>> CanBus::listenForErrors(const sp<ICanErrorListener>& listener) {
     if (listener == nullptr) {
         return new CloseHandle();
     }

     std::lock_guard<std::mutex> upLck(mIsUpGuard);
     if (!mIsUp) {
         listener->onError(ErrorEvent::INTERFACE_DOWN, true);
         return new CloseHandle();
     }

     std::lock_guard<std::mutex> errLck(mErrListenersGuard);
     mErrListeners.emplace_back(listener);

     return new CloseHandle([this, listener]() {
         std::lock_guard<std::mutex> lck(mErrListenersGuard);
         std::erase(mErrListeners, listener);
     });
 }

 bool CanBus::down() {
     std::lock_guard<std::mutex> lck(mIsUpGuard);

     if (!mIsUp) {
         LOG(WARNING) << "Interface is already down";
         return false;
     }
     mIsUp = false;

     clearMsgListeners();
     clearErrListeners();
     mSocket.reset();

     bool success = true;

     if (mDownAfterUse && !netdevice::down(mIfname)) {
         LOG(ERROR) << "Can't bring " << mIfname << " down";
         // don't return yet, let's try to do best-effort cleanup
         success = false;
     }

     if (!postDown()) success = false;

     return success;
 }

 /**
  * Helper function to determine if a flag meets the requirements of a
  * FilterFlag. See definition of FilterFlag in types.hal
  *
  * \param filterFlag FilterFlag object to match flag against
  * \param flag bool object from CanMessage object
  */
 static bool satisfiesFilterFlag(FilterFlag filterFlag, bool flag) {
     if (filterFlag == FilterFlag::DONT_CARE) return true;
     if (filterFlag == FilterFlag::SET) return flag;
     if (filterFlag == FilterFlag::NOT_SET) return !flag;
     return false;
 }

 /**
  * Match the filter set against message id.
  *
  * For details on the filters syntax, please see CanMessageFilter at
  * the HAL definition (types.hal).
  *
  * \param filter Filter to match against
  * \param id Message id to filter
  * \return true if the message id matches the filter, false otherwise
  */
 static bool match(const hidl_vec<CanMessageFilter>& filter, CanMessageId id, bool isRtr,
                   bool isExtendedId) {
     if (filter.size() == 0) return true;

     bool anyNonExcludeRulePresent = false;
     bool anyNonExcludeRuleSatisfied = false;
     for (auto& rule : filter) {
         const bool satisfied = ((id & rule.mask) == rule.id) &&
                                satisfiesFilterFlag(rule.rtr, isRtr) &&
                                satisfiesFilterFlag(rule.extendedFormat, isExtendedId);

         if (rule.exclude) {
             // Any excluded (blacklist) rule not being satisfied invalidates the whole filter set.
             if (satisfied) return false;
         } else {
             anyNonExcludeRulePresent = true;
             if (satisfied) anyNonExcludeRuleSatisfied = true;
         }
     }
     return !anyNonExcludeRulePresent || anyNonExcludeRuleSatisfied;
 }

 void CanBus::notifyErrorListeners(ErrorEvent err, bool isFatal) {
     std::lock_guard<std::mutex> lck(mErrListenersGuard);
     for (auto& listener : mErrListeners) {
         if (!listener->onError(err, isFatal).isOk()) {
             LOG(WARNING) << "Failed to notify listener about error";
         }
     }
 }

 static ErrorEvent parseErrorFrame(const struct canfd_frame& frame) {
     // decode error frame (to a degree)
     if ((frame.can_id & (CAN_ERR_BUSERROR | CAN_ERR_BUSOFF)) != 0) {
         return ErrorEvent::BUS_ERROR;
     }
     if ((frame.data[1] & CAN_ERR_CRTL_TX_OVERFLOW) != 0) {
         return ErrorEvent::TX_OVERFLOW;
     }
     if ((frame.data[1] & CAN_ERR_CRTL_RX_OVERFLOW) != 0) {
         return ErrorEvent::RX_OVERFLOW;
     }
     if ((frame.data[2] & CAN_ERR_PROT_OVERLOAD) != 0) {
         return ErrorEvent::BUS_OVERLOAD;
     }
     if ((frame.can_id & CAN_ERR_PROT) != 0) {
         return ErrorEvent::MALFORMED_INPUT;
     }
     if ((frame.can_id & (CAN_ERR_CRTL | CAN_ERR_TRX | CAN_ERR_RESTARTED)) != 0) {
         // "controller restarted" constitutes a HARDWARE_ERROR imo
         return ErrorEvent::HARDWARE_ERROR;
     }
     return ErrorEvent::UNKNOWN_ERROR;
 }

 void CanBus::onRead(const struct canfd_frame& frame, std::chrono::nanoseconds timestamp) {
     if ((frame.can_id & CAN_ERR_FLAG) != 0) {
         // error bit is set
         LOG(WARNING) << "CAN Error frame received";
         notifyErrorListeners(parseErrorFrame(frame), false);
         return;
     }

     CanMessage message = {};
     message.id = frame.can_id & CAN_EFF_MASK;  // mask out eff/rtr/err flags
     message.payload = hidl_vec<uint8_t>(frame.data, frame.data + frame.len);
     message.timestamp = timestamp.count();
     message.isExtendedId = (frame.can_id & CAN_EFF_FLAG) != 0;
     message.remoteTransmissionRequest = (frame.can_id & CAN_RTR_FLAG) != 0;

     if (UNLIKELY(kSuperVerbose)) {
         LOG(VERBOSE) << "Got message " << toString(message);
     }

     std::lock_guard<std::mutex> lck(mMsgListenersGuard);
     for (auto& listener : mMsgListeners) {
         if (!match(listener.filter, message.id, message.remoteTransmissionRequest,
                    message.isExtendedId))
             continue;
         if (!listener.callback->onReceive(message).isOk() && !listener.failedOnce) {
             listener.failedOnce = true;
             LOG(WARNING) << "Failed to notify listener about message";
         }
     }
 }

 void CanBus::onError(int errnoVal) {
     auto eventType = ErrorEvent::HARDWARE_ERROR;

     if (errnoVal == ENODEV || errnoVal == ENETDOWN) {
         mDownAfterUse = false;
         eventType = ErrorEvent::INTERFACE_DOWN;
     }
     notifyErrorListeners(eventType, true);

     const auto errcb = mErrCb;
     if (errcb != nullptr) errcb();
 }

 }  // namespace android::hardware::automotive::can::V1_0::implementation
	/*
	* Copyright (C) 2019 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 "CanBus.h"

	#include "CloseHandle.h"

	#include <android-base/logging.h>
	#include <libnetdevice/can.h>
	#include <libnetdevice/libnetdevice.h>
	#include <linux/can.h>
	#include <linux/can/error.h>
	#include <linux/can/raw.h>

	namespace android::hardware::automotive::can::V1_0::implementation {

	/** Whether to log sent/received packets. */
	static constexpr bool kSuperVerbose = false;

	Return<Result> CanBus::send(const CanMessage& message) {
	std::lock_guard<std::mutex> lck(mIsUpGuard);
	if (!mIsUp) return Result::INTERFACE_DOWN;

	if (UNLIKELY(kSuperVerbose)) {
	LOG(VERBOSE) << "Sending " << toString(message);
	}

	if (message.payload.size() > CAN_MAX_DLEN) return Result::PAYLOAD_TOO_LONG;

	struct canfd_frame frame = {};
	frame.can_id = message.id;
	if (message.isExtendedId) frame.can_id \|= CAN_EFF_FLAG;
	if (message.remoteTransmissionRequest) frame.can_id \|= CAN_RTR_FLAG;
	frame.len = message.payload.size();
	memcpy(frame.data, message.payload.data(), message.payload.size());

	if (!mSocket->send(frame)) return Result::TRANSMISSION_FAILURE;

	return Result::OK;
	}

	Return<void> CanBus::listen(const hidl_vec<CanMessageFilter>& filter,
	const sp<ICanMessageListener>& listenerCb, listen_cb _hidl_cb) {
	std::lock_guard<std::mutex> lck(mIsUpGuard);

	if (listenerCb == nullptr) {
	_hidl_cb(Result::INVALID_ARGUMENTS, nullptr);
	return {};
	}
	if (!mIsUp) {
	_hidl_cb(Result::INTERFACE_DOWN, nullptr);
	return {};
	}

	std::lock_guard<std::mutex> lckListeners(mMsgListenersGuard);

	sp<CloseHandle> closeHandle = new CloseHandle([this, listenerCb]() {
	std::lock_guard<std::mutex> lck(mMsgListenersGuard);
	std::erase_if(mMsgListeners, [&](const auto& e) { return e.callback == listenerCb; });
	});
	mMsgListeners.emplace_back(CanMessageListener{listenerCb, filter, closeHandle});
	auto& listener = mMsgListeners.back();

	// fix message IDs to have all zeros on bits not covered by mask
	std::for_each(listener.filter.begin(), listener.filter.end(),
	[](auto& rule) { rule.id &= rule.mask; });

	_hidl_cb(Result::OK, closeHandle);
	return {};
	}

	CanBus::CanBus() {}

	CanBus::CanBus(const std::string& ifname) : mIfname(ifname) {}

	CanBus::~CanBus() {
	std::lock_guard<std::mutex> lck(mIsUpGuard);
	CHECK(!mIsUp) << "Interface is still up while being destroyed";

	std::lock_guard<std::mutex> lckListeners(mMsgListenersGuard);
	CHECK(mMsgListeners.empty()) << "Listener list is not empty while interface is being destroyed";
	}

	void CanBus::setErrorCallback(ErrorCallback errcb) {
	CHECK(!mIsUp) << "Can't set error callback while interface is up";
	CHECK(mErrCb == nullptr) << "Error callback is already set";
	mErrCb = errcb;
	CHECK(!mIsUp) << "Can't set error callback while interface is up";
	}

	ICanController::Result CanBus::preUp() {
	return ICanController::Result::OK;
	}

	bool CanBus::postDown() {
	return true;
	}

	ICanController::Result CanBus::up() {
	std::lock_guard<std::mutex> lck(mIsUpGuard);

	if (mIsUp) {
	LOG(WARNING) << "Interface is already up";
	return ICanController::Result::INVALID_STATE;
	}

	const auto preResult = preUp();
	if (preResult != ICanController::Result::OK) return preResult;

	const auto isUp = netdevice::isUp(mIfname);
	if (!isUp.has_value()) {
	// preUp() should prepare the interface (either create or make sure it's there)
	LOG(ERROR) << "Interface " << mIfname << " didn't get prepared";
	return ICanController::Result::BAD_INTERFACE_ID;
	}

	if (!*isUp && !netdevice::up(mIfname)) {
	LOG(ERROR) << "Can't bring " << mIfname << " up";
	return ICanController::Result::UNKNOWN_ERROR;
	}
	mDownAfterUse = !*isUp;

	using namespace std::placeholders;
	CanSocket::ReadCallback rdcb = std::bind(&CanBus::onRead, this, _1, _2);
	CanSocket::ErrorCallback errcb = std::bind(&CanBus::onError, this, _1);
	mSocket = CanSocket::open(mIfname, rdcb, errcb);
	if (!mSocket) {
	if (mDownAfterUse) netdevice::down(mIfname);
	return ICanController::Result::UNKNOWN_ERROR;
	}

	mIsUp = true;
	return ICanController::Result::OK;
	}

	void CanBus::clearMsgListeners() {
	std::vector<wp<ICloseHandle>> listenersToClose;
	{
	std::lock_guard<std::mutex> lck(mMsgListenersGuard);
	std::transform(mMsgListeners.begin(), mMsgListeners.end(),
	std::back_inserter(listenersToClose),
	[](const auto& e) { return e.closeHandle; });
	}

	for (auto& weakListener : listenersToClose) {
	/* Between populating listenersToClose and calling close method here, some listeners might
	* have been already removed from the original mMsgListeners list (resulting in a dangling
	* weak pointer here). It's fine - we just want to clean them up. */
	auto listener = weakListener.promote();
	if (listener != nullptr) listener->close();
	}

	std::lock_guard<std::mutex> lck(mMsgListenersGuard);
	CHECK(mMsgListeners.empty()) << "Listeners list wasn't emptied";
	}

	void CanBus::clearErrListeners() {
	std::lock_guard<std::mutex> lck(mErrListenersGuard);
	mErrListeners.clear();
	}

	Return<sp<ICloseHandle>> CanBus::listenForErrors(const sp<ICanErrorListener>& listener) {
	if (listener == nullptr) {
	return new CloseHandle();
	}

	std::lock_guard<std::mutex> upLck(mIsUpGuard);
	if (!mIsUp) {
	listener->onError(ErrorEvent::INTERFACE_DOWN, true);
	return new CloseHandle();
	}

	std::lock_guard<std::mutex> errLck(mErrListenersGuard);
	mErrListeners.emplace_back(listener);

	return new CloseHandle([this, listener]() {
	std::lock_guard<std::mutex> lck(mErrListenersGuard);
	std::erase(mErrListeners, listener);
	});
	}

	bool CanBus::down() {
	std::lock_guard<std::mutex> lck(mIsUpGuard);

	if (!mIsUp) {
	LOG(WARNING) << "Interface is already down";
	return false;
	}
	mIsUp = false;

	clearMsgListeners();
	clearErrListeners();
	mSocket.reset();

	bool success = true;

	if (mDownAfterUse && !netdevice::down(mIfname)) {
	LOG(ERROR) << "Can't bring " << mIfname << " down";
	// don't return yet, let's try to do best-effort cleanup
	success = false;
	}

	if (!postDown()) success = false;

	return success;
	}

	/**
	* Helper function to determine if a flag meets the requirements of a
	* FilterFlag. See definition of FilterFlag in types.hal
	*
	* \param filterFlag FilterFlag object to match flag against
	* \param flag bool object from CanMessage object
	*/
	static bool satisfiesFilterFlag(FilterFlag filterFlag, bool flag) {
	if (filterFlag == FilterFlag::DONT_CARE) return true;
	if (filterFlag == FilterFlag::SET) return flag;
	if (filterFlag == FilterFlag::NOT_SET) return !flag;
	return false;
	}

	/**
	* Match the filter set against message id.
	*
	* For details on the filters syntax, please see CanMessageFilter at
	* the HAL definition (types.hal).
	*
	* \param filter Filter to match against
	* \param id Message id to filter
	* \return true if the message id matches the filter, false otherwise
	*/
	static bool match(const hidl_vec<CanMessageFilter>& filter, CanMessageId id, bool isRtr,
	bool isExtendedId) {
	if (filter.size() == 0) return true;

	bool anyNonExcludeRulePresent = false;
	bool anyNonExcludeRuleSatisfied = false;
	for (auto& rule : filter) {
	const bool satisfied = ((id & rule.mask) == rule.id) &&
	satisfiesFilterFlag(rule.rtr, isRtr) &&
	satisfiesFilterFlag(rule.extendedFormat, isExtendedId);

	if (rule.exclude) {
	// Any excluded (blacklist) rule not being satisfied invalidates the whole filter set.
	if (satisfied) return false;
	} else {
	anyNonExcludeRulePresent = true;
	if (satisfied) anyNonExcludeRuleSatisfied = true;
	}
	}
	return !anyNonExcludeRulePresent \|\| anyNonExcludeRuleSatisfied;
	}

	void CanBus::notifyErrorListeners(ErrorEvent err, bool isFatal) {
	std::lock_guard<std::mutex> lck(mErrListenersGuard);
	for (auto& listener : mErrListeners) {
	if (!listener->onError(err, isFatal).isOk()) {
	LOG(WARNING) << "Failed to notify listener about error";
	}
	}
	}

	static ErrorEvent parseErrorFrame(const struct canfd_frame& frame) {
	// decode error frame (to a degree)
	if ((frame.can_id & (CAN_ERR_BUSERROR \| CAN_ERR_BUSOFF)) != 0) {
	return ErrorEvent::BUS_ERROR;
	}
	if ((frame.data[1] & CAN_ERR_CRTL_TX_OVERFLOW) != 0) {
	return ErrorEvent::TX_OVERFLOW;
	}
	if ((frame.data[1] & CAN_ERR_CRTL_RX_OVERFLOW) != 0) {
	return ErrorEvent::RX_OVERFLOW;
	}
	if ((frame.data[2] & CAN_ERR_PROT_OVERLOAD) != 0) {
	return ErrorEvent::BUS_OVERLOAD;
	}
	if ((frame.can_id & CAN_ERR_PROT) != 0) {
	return ErrorEvent::MALFORMED_INPUT;
	}
	if ((frame.can_id & (CAN_ERR_CRTL \| CAN_ERR_TRX \| CAN_ERR_RESTARTED)) != 0) {
	// "controller restarted" constitutes a HARDWARE_ERROR imo
	return ErrorEvent::HARDWARE_ERROR;
	}
	return ErrorEvent::UNKNOWN_ERROR;
	}

	void CanBus::onRead(const struct canfd_frame& frame, std::chrono::nanoseconds timestamp) {
	if ((frame.can_id & CAN_ERR_FLAG) != 0) {
	// error bit is set
	LOG(WARNING) << "CAN Error frame received";
	notifyErrorListeners(parseErrorFrame(frame), false);
	return;
	}

	CanMessage message = {};
	message.id = frame.can_id & CAN_EFF_MASK; // mask out eff/rtr/err flags
	message.payload = hidl_vec<uint8_t>(frame.data, frame.data + frame.len);
	message.timestamp = timestamp.count();
	message.isExtendedId = (frame.can_id & CAN_EFF_FLAG) != 0;
	message.remoteTransmissionRequest = (frame.can_id & CAN_RTR_FLAG) != 0;

	if (UNLIKELY(kSuperVerbose)) {
	LOG(VERBOSE) << "Got message " << toString(message);
	}

	std::lock_guard<std::mutex> lck(mMsgListenersGuard);
	for (auto& listener : mMsgListeners) {
	if (!match(listener.filter, message.id, message.remoteTransmissionRequest,
	message.isExtendedId))
	continue;
	if (!listener.callback->onReceive(message).isOk() && !listener.failedOnce) {
	listener.failedOnce = true;
	LOG(WARNING) << "Failed to notify listener about message";
	}
	}
	}

	void CanBus::onError(int errnoVal) {
	auto eventType = ErrorEvent::HARDWARE_ERROR;

	if (errnoVal == ENODEV \|\| errnoVal == ENETDOWN) {
	mDownAfterUse = false;
	eventType = ErrorEvent::INTERFACE_DOWN;
	}
	notifyErrorListeners(eventType, true);

	const auto errcb = mErrCb;
	if (errcb != nullptr) errcb();
	}

	} // namespace android::hardware::automotive::can::V1_0::implementation