src/core/thread/energy_scan_server.cpp

/*
 *  Copyright (c) 2016, The OpenThread Authors.
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 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
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 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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/**
 * @file
 *   This file implements the Energy Scan Server.
 */

#include "energy_scan_server.hpp"

#include "coap/coap_message.hpp"
#include "common/code_utils.hpp"
#include "common/debug.hpp"
#include "common/instance.hpp"
#include "common/locator-getters.hpp"
#include "common/logging.hpp"
#include "meshcop/meshcop.hpp"
#include "meshcop/meshcop_tlvs.hpp"
#include "thread/thread_netif.hpp"
#include "thread/thread_uri_paths.hpp"

namespace ot {

EnergyScanServer::EnergyScanServer(Instance &aInstance)
    : InstanceLocator(aInstance)
    , mChannelMask(0)
    , mChannelMaskCurrent(0)
    , mPeriod(0)
    , mScanDuration(0)
    , mCount(0)
    , mActive(false)
    , mScanResultsLength(0)
    , mTimer(aInstance, &EnergyScanServer::HandleTimer, this)
    , mNotifierCallback(aInstance, &EnergyScanServer::HandleStateChanged, this)
    , mEnergyScan(OT_URI_PATH_ENERGY_SCAN, &EnergyScanServer::HandleRequest, this)
{
    Get<Coap::Coap>().AddResource(mEnergyScan);
}

void EnergyScanServer::HandleRequest(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo)
{
    static_cast<EnergyScanServer *>(aContext)->HandleRequest(*static_cast<Coap::Message *>(aMessage),
                                                             *static_cast<const Ip6::MessageInfo *>(aMessageInfo));
}

void EnergyScanServer::HandleRequest(Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
{
    MeshCoP::CountTlv        count;
    MeshCoP::PeriodTlv       period;
    MeshCoP::ScanDurationTlv scanDuration;
    Ip6::MessageInfo         responseInfo(aMessageInfo);
    uint32_t                 mask;

    VerifyOrExit(aMessage.GetCode() == OT_COAP_CODE_POST);

    SuccessOrExit(MeshCoP::Tlv::GetTlv(aMessage, MeshCoP::Tlv::kCount, sizeof(count), count));
    VerifyOrExit(count.IsValid());

    SuccessOrExit(MeshCoP::Tlv::GetTlv(aMessage, MeshCoP::Tlv::kPeriod, sizeof(period), period));
    VerifyOrExit(period.IsValid());

    SuccessOrExit(MeshCoP::Tlv::GetTlv(aMessage, MeshCoP::Tlv::kScanDuration, sizeof(scanDuration), scanDuration));
    VerifyOrExit(scanDuration.IsValid());

    VerifyOrExit((mask = MeshCoP::ChannelMaskTlv::GetChannelMask(aMessage)) != 0);

    mChannelMask        = mask;
    mChannelMaskCurrent = mChannelMask;
    mCount              = count.GetCount();
    mPeriod             = period.GetPeriod();
    mScanDuration       = scanDuration.GetScanDuration();
    mScanResultsLength  = 0;
    mActive             = true;
    mTimer.Start(kScanDelay);

    mCommissioner = aMessageInfo.GetPeerAddr();

    if (aMessage.IsConfirmable() && !aMessageInfo.GetSockAddr().IsMulticast())
    {
        SuccessOrExit(Get<Coap::Coap>().SendEmptyAck(aMessage, responseInfo));
        otLogInfoMeshCoP("sent energy scan query response");
    }

exit:
    return;
}

void EnergyScanServer::HandleTimer(Timer &aTimer)
{
    aTimer.GetOwner<EnergyScanServer>().HandleTimer();
}

void EnergyScanServer::HandleTimer(void)
{
    VerifyOrExit(mActive);

    if (mCount)
    {
        // grab the lowest channel to scan
        uint32_t channelMask = mChannelMaskCurrent & ~(mChannelMaskCurrent - 1);
        Get<Mac::Mac>().EnergyScan(channelMask, mScanDuration, HandleScanResult, this);
    }
    else
    {
        SendReport();
    }

exit:
    return;
}

void EnergyScanServer::HandleScanResult(Mac::EnergyScanResult *aResult, void *aContext)
{
    static_cast<EnergyScanServer *>(aContext)->HandleScanResult(aResult);
}

void EnergyScanServer::HandleScanResult(Mac::EnergyScanResult *aResult)
{
    VerifyOrExit(mActive);

    if (aResult)
    {
        mScanResults[mScanResultsLength++] = aResult->mMaxRssi;
    }
    else
    {
        // clear the lowest channel to scan
        mChannelMaskCurrent &= mChannelMaskCurrent - 1;

        if (mChannelMaskCurrent == 0)
        {
            mChannelMaskCurrent = mChannelMask;
            mCount--;
        }

        if (mCount)
        {
            mTimer.Start(mPeriod);
        }
        else
        {
            mTimer.Start(kReportDelay);
        }
    }

exit:
    return;
}

otError EnergyScanServer::SendReport(void)
{
    otError                 error = OT_ERROR_NONE;
    MeshCoP::ChannelMaskTlv channelMask;
    MeshCoP::EnergyListTlv  energyList;
    Ip6::MessageInfo        messageInfo;
    Coap::Message *         message;

    VerifyOrExit((message = MeshCoP::NewMeshCoPMessage(Get<Coap::Coap>())) != NULL, error = OT_ERROR_NO_BUFS);

    SuccessOrExit(error = message->Init(OT_COAP_TYPE_CONFIRMABLE, OT_COAP_CODE_POST, OT_URI_PATH_ENERGY_REPORT));
    SuccessOrExit(error = message->SetPayloadMarker());

    channelMask.Init();
    channelMask.SetChannelMask(mChannelMask);
    SuccessOrExit(error = channelMask.AppendTo(*message));

    energyList.Init();
    energyList.SetLength(mScanResultsLength);
    SuccessOrExit(error = message->Append(&energyList, sizeof(energyList)));
    SuccessOrExit(error = message->Append(mScanResults, mScanResultsLength));

    messageInfo.SetSockAddr(Get<Mle::MleRouter>().GetMeshLocal16());
    messageInfo.SetPeerAddr(mCommissioner);
    messageInfo.SetPeerPort(kCoapUdpPort);
    SuccessOrExit(error = Get<Coap::Coap>().SendMessage(*message, messageInfo));

    otLogInfoMeshCoP("sent scan results");

exit:

    if (error != OT_ERROR_NONE && message != NULL)
    {
        message->Free();
    }

    mActive = false;

    return error;
}

void EnergyScanServer::HandleStateChanged(Notifier::Callback &aCallback, otChangedFlags aFlags)
{
    aCallback.GetOwner<EnergyScanServer>().HandleStateChanged(aFlags);
}

void EnergyScanServer::HandleStateChanged(otChangedFlags aFlags)
{
    if ((aFlags & OT_CHANGED_THREAD_NETDATA) != 0 && !mActive &&
        Get<NetworkData::Leader>().GetCommissioningData() == NULL)
    {
        mActive = false;
        mTimer.Stop();
    }
}

} // namespace ot