automotive/can/aidl/default/CanBusNative.cpp

/*
 * Copyright 2022, 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 "CanBusNative.h"

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

namespace aidl::android::hardware::automotive::can {

using namespace ::android;

CanBusNative::CanBusNative(const std::string& ifname, uint32_t bitrate)
    : CanBus(ifname), mBitrate(bitrate) {}

Result CanBusNative::preUp() {
    if (!netdevice::exists(mIfname)) {
        LOG(ERROR) << "Interface " << mIfname << " doesn't exist";
        return Result::BAD_INTERFACE_ID;
    }

    if (mBitrate == 0) {
        // interface is already up and we just want to register it
        return Result::OK;
    }

    if (!netdevice::down(mIfname)) {
        LOG(ERROR) << "Can't bring " << mIfname << " down (to configure it)";
        return Result::UNKNOWN_ERROR;
    }

    if (!netdevice::can::setBitrate(mIfname, mBitrate)) {
        LOG(ERROR) << "Can't set bitrate " << mBitrate << " for " << mIfname;
        return Result::BAD_BITRATE;
    }

    return Result::OK;
}

}  // namespace aidl::android::hardware::automotive::can