Beispiel #1
0
otError Leader::SendDatasetChanged(const Ip6::Address &aAddress)
{
    ThreadNetif &netif = GetNetif();
    otError error = OT_ERROR_NONE;
    Coap::Header header;
    Ip6::MessageInfo messageInfo;
    Message *message;

    header.Init(OT_COAP_TYPE_CONFIRMABLE, OT_COAP_CODE_POST);
    header.SetToken(Coap::Header::kDefaultTokenLength);
    header.AppendUriPathOptions(OT_URI_PATH_DATASET_CHANGED);

    VerifyOrExit((message = NewMeshCoPMessage(netif.GetCoap(), header)) != NULL, error = OT_ERROR_NO_BUFS);

    messageInfo.SetSockAddr(netif.GetMle().GetMeshLocal16());
    messageInfo.SetPeerAddr(aAddress);
    messageInfo.SetPeerPort(kCoapUdpPort);
    SuccessOrExit(error = netif.GetCoap().SendMessage(*message, messageInfo));

    otLogInfoMeshCoP(GetInstance(), "sent dataset changed");

exit:

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

    return error;
}
Beispiel #2
0
void Joiner::HandleUdpTransmit(void)
{
    ThreadError error = kThreadError_None;
    Ip6::MessageInfo messageInfo;

    otLogFuncEntry();

    VerifyOrExit(mTransmitMessage != NULL, error = kThreadError_NoBufs);

    otLogInfoMeshCoP("transmit %d (to %llX)", mTransmitMessage->GetLength(),
                     HostSwap64(*reinterpret_cast<uint64_t *>(&mJoinerRouter)));

    messageInfo.GetPeerAddr().mFields.m16[0] = HostSwap16(0xfe80);
    messageInfo.GetPeerAddr().SetIid(mJoinerRouter);
    messageInfo.SetPeerPort(mJoinerUdpPort);
    messageInfo.SetInterfaceId(OT_NETIF_INTERFACE_ID_THREAD);

    SuccessOrExit(error = mSocket.SendTo(*mTransmitMessage, messageInfo));

exit:

    if (error != kThreadError_None && mTransmitMessage != NULL)
    {
        mTransmitMessage->Free();
    }

    mTransmitMessage = NULL;
    otLogFuncExit();
}
Beispiel #3
0
void JoinerRouter::HandleUdpReceive(Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
{
    ThreadNetif &          netif = GetNetif();
    otError                error;
    Coap::Message *        message = NULL;
    Ip6::MessageInfo       messageInfo;
    JoinerUdpPortTlv       udpPort;
    JoinerIidTlv           iid;
    JoinerRouterLocatorTlv rloc;
    ExtendedTlv            tlv;
    uint16_t               borderAgentRloc;
    uint16_t               offset;

    otLogInfoMeshCoP("JoinerRouter::HandleUdpReceive");

    SuccessOrExit(error = GetBorderAgentRloc(GetNetif(), borderAgentRloc));

    VerifyOrExit((message = NewMeshCoPMessage(netif.GetCoap())) != NULL, error = OT_ERROR_NO_BUFS);

    message->Init(OT_COAP_TYPE_NON_CONFIRMABLE, OT_COAP_CODE_POST);
    message->SetToken(Coap::Message::kDefaultTokenLength);
    message->AppendUriPathOptions(OT_URI_PATH_RELAY_RX);
    message->SetPayloadMarker();

    udpPort.Init();
    udpPort.SetUdpPort(aMessageInfo.GetPeerPort());
    SuccessOrExit(error = message->Append(&udpPort, sizeof(udpPort)));

    iid.Init();
    iid.SetIid(aMessageInfo.GetPeerAddr().mFields.m8 + 8);
    SuccessOrExit(error = message->Append(&iid, sizeof(iid)));

    rloc.Init();
    rloc.SetJoinerRouterLocator(netif.GetMle().GetRloc16());
    SuccessOrExit(error = message->Append(&rloc, sizeof(rloc)));

    tlv.SetType(Tlv::kJoinerDtlsEncapsulation);
    tlv.SetLength(aMessage.GetLength() - aMessage.GetOffset());
    SuccessOrExit(error = message->Append(&tlv, sizeof(tlv)));
    offset = message->GetLength();
    SuccessOrExit(error = message->SetLength(offset + tlv.GetLength()));
    aMessage.CopyTo(aMessage.GetOffset(), offset, tlv.GetLength(), *message);

    messageInfo.SetSockAddr(netif.GetMle().GetMeshLocal16());
    messageInfo.SetPeerAddr(netif.GetMle().GetMeshLocal16());
    messageInfo.GetPeerAddr().mFields.m16[7] = HostSwap16(borderAgentRloc);
    messageInfo.SetPeerPort(kCoapUdpPort);

    SuccessOrExit(error = netif.GetCoap().SendMessage(*message, messageInfo));

    otLogInfoMeshCoP("Sent relay rx");

exit:

    if (error != OT_ERROR_NONE && message != NULL)
    {
        message->Free();
    }
}
otError AnnounceBeginClient::SendRequest(uint32_t aChannelMask, uint8_t aCount, uint16_t aPeriod,
                                         const Ip6::Address &aAddress)
{
    otError error = OT_ERROR_NONE;
    Coap::Header header;
    MeshCoP::CommissionerSessionIdTlv sessionId;
    MeshCoP::ChannelMask0Tlv channelMask;
    MeshCoP::CountTlv count;
    MeshCoP::PeriodTlv period;

    Ip6::MessageInfo messageInfo;
    Message *message = NULL;

    VerifyOrExit(GetNetif().GetCommissioner().IsActive(), error = OT_ERROR_INVALID_STATE);

    header.Init(aAddress.IsMulticast() ? OT_COAP_TYPE_NON_CONFIRMABLE : OT_COAP_TYPE_CONFIRMABLE,
                OT_COAP_CODE_POST);
    header.SetToken(Coap::Header::kDefaultTokenLength);
    header.AppendUriPathOptions(OT_URI_PATH_ANNOUNCE_BEGIN);
    header.SetPayloadMarker();

    VerifyOrExit((message = MeshCoP::NewMeshCoPMessage(GetNetif().GetCoap(), header)) != NULL,
                 error = OT_ERROR_NO_BUFS);

    sessionId.Init();
    sessionId.SetCommissionerSessionId(GetNetif().GetCommissioner().GetSessionId());
    SuccessOrExit(error = message->Append(&sessionId, sizeof(sessionId)));

    channelMask.Init();
    channelMask.SetMask(aChannelMask);
    SuccessOrExit(error = message->Append(&channelMask, sizeof(channelMask)));

    count.Init();
    count.SetCount(aCount);
    SuccessOrExit(error = message->Append(&count, sizeof(count)));

    period.Init();
    period.SetPeriod(aPeriod);
    SuccessOrExit(error = message->Append(&period, sizeof(period)));

    messageInfo.SetSockAddr(GetNetif().GetMle().GetMeshLocal16());
    messageInfo.SetPeerAddr(aAddress);
    messageInfo.SetPeerPort(kCoapUdpPort);
    messageInfo.SetInterfaceId(GetNetif().GetInterfaceId());

    SuccessOrExit(error = GetNetif().GetCoap().SendMessage(*message, messageInfo));

    otLogInfoMeshCoP(GetInstance(), "sent announce begin query");

exit:

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

    return error;
}
otError PanIdQueryClient::SendQuery(uint16_t aPanId, uint32_t aChannelMask, const Ip6::Address &aAddress,
                                    otCommissionerPanIdConflictCallback aCallback, void *aContext)
{
    ThreadNetif &netif = GetNetif();
    otError error = OT_ERROR_NONE;
    Coap::Header header;
    MeshCoP::CommissionerSessionIdTlv sessionId;
    MeshCoP::ChannelMask0Tlv channelMask;
    MeshCoP::PanIdTlv panId;
    Ip6::MessageInfo messageInfo;
    Message *message = NULL;

    VerifyOrExit(netif.GetCommissioner().IsActive(), error = OT_ERROR_INVALID_STATE);

    header.Init(aAddress.IsMulticast() ? OT_COAP_TYPE_NON_CONFIRMABLE : OT_COAP_TYPE_CONFIRMABLE,
                OT_COAP_CODE_POST);
    header.SetToken(Coap::Header::kDefaultTokenLength);
    header.AppendUriPathOptions(OT_URI_PATH_PANID_QUERY);
    header.SetPayloadMarker();

    VerifyOrExit((message = MeshCoP::NewMeshCoPMessage(netif.GetCoap(), header)) != NULL,
                 error = OT_ERROR_NO_BUFS);

    sessionId.Init();
    sessionId.SetCommissionerSessionId(netif.GetCommissioner().GetSessionId());
    SuccessOrExit(error = message->Append(&sessionId, sizeof(sessionId)));

    channelMask.Init();
    channelMask.SetMask(aChannelMask);
    SuccessOrExit(error = message->Append(&channelMask, sizeof(channelMask)));

    panId.Init();
    panId.SetPanId(aPanId);
    SuccessOrExit(error = message->Append(&panId, sizeof(panId)));

    messageInfo.SetSockAddr(netif.GetMle().GetMeshLocal16());
    messageInfo.SetPeerAddr(aAddress);
    messageInfo.SetPeerPort(kCoapUdpPort);
    messageInfo.SetInterfaceId(netif.GetInterfaceId());
    SuccessOrExit(error = netif.GetCoap().SendMessage(*message, messageInfo));

    otLogInfoMeshCoP(GetInstance(), "sent panid query");

    mCallback = aCallback;
    mContext = aContext;

exit:

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

    return error;
}
otError EnergyScanServer::SendReport(void)
{
    otError                  error = OT_ERROR_NONE;
    Coap::Header             header;
    MeshCoP::ChannelMask0Tlv channelMask;
    MeshCoP::EnergyListTlv   energyList;
    Ip6::MessageInfo         messageInfo;
    Message *                message;

    header.Init(OT_COAP_TYPE_CONFIRMABLE, OT_COAP_CODE_POST);
    header.SetToken(Coap::Header::kDefaultTokenLength);
    header.AppendUriPathOptions(OT_URI_PATH_ENERGY_REPORT);
    header.SetPayloadMarker();

    VerifyOrExit((message = MeshCoP::NewMeshCoPMessage(GetNetif().GetCoap(), header)) != NULL,
                 error = OT_ERROR_NO_BUFS);

    channelMask.Init();
    channelMask.SetMask(mChannelMask);
    SuccessOrExit(error = message->Append(&channelMask, sizeof(channelMask)));

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

    messageInfo.SetSockAddr(GetNetif().GetMle().GetMeshLocal16());
    messageInfo.SetPeerAddr(mCommissioner);
    messageInfo.SetPeerPort(kCoapUdpPort);
    SuccessOrExit(error = GetNetif().GetCoap().SendMessage(*message, messageInfo));

    otLogInfoMeshCoP(GetInstance(), "sent scan results");

exit:

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

    mActive = false;

    return error;
}
ThreadError DatasetManager::Register(void)
{
    ThreadError error = kThreadError_None;
    Coap::Header header;
    Message *message;
    Ip6::Address leader;
    Ip6::MessageInfo messageInfo;

    header.Init(kCoapTypeConfirmable, kCoapRequestPost);
    header.SetToken(Coap::Header::kDefaultTokenLength);
    header.AppendUriPathOptions(mUriSet);
    header.SetPayloadMarker();

    if (strcmp(mUriSet, OPENTHREAD_URI_PENDING_SET) == 0)
    {
        PendingDatasetBase *pending = static_cast<PendingDatasetBase *>(this);
        pending->UpdateDelayTimer();
    }

    VerifyOrExit((message = mNetif.GetCoapClient().NewMeshCoPMessage(header)) != NULL, error = kThreadError_NoBufs);

    SuccessOrExit(error = message->Append(mLocal.GetBytes(), mLocal.GetSize()));

    mNetif.GetMle().GetLeaderAloc(leader);

    messageInfo.SetPeerAddr(leader);
    messageInfo.SetPeerPort(kCoapUdpPort);
    SuccessOrExit(error = mNetif.GetCoapClient().SendMessage(*message, messageInfo));

    otLogInfoMeshCoP("sent dataset to leader");

exit:

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

    return error;
}
Beispiel #8
0
void otUdpProxyReceive(otInstance *        aInstance,
                       otMessage *         aMessage,
                       uint16_t            aPeerPort,
                       const otIp6Address *aPeerAddr,
                       uint16_t            aSockPort)
{
    Ip6::MessageInfo messageInfo;
    Instance &       instance = *static_cast<Instance *>(aInstance);
    Ip6::Ip6 &       ip6      = instance.Get<Ip6::Ip6>();

    assert(aMessage != NULL && aPeerAddr != NULL);

    messageInfo.SetSockAddr(instance.GetThreadNetif().GetMle().GetMeshLocal16());
    messageInfo.SetSockPort(aSockPort);
    messageInfo.SetPeerAddr(*static_cast<const ot::Ip6::Address *>(aPeerAddr));
    messageInfo.SetPeerPort(aPeerPort);
    messageInfo.SetInterfaceId(OT_NETIF_INTERFACE_ID_HOST);

    ip6.GetUdp().HandlePayload(*static_cast<ot::Message *>(aMessage), messageInfo);

    static_cast<ot::Message *>(aMessage)->Free();
}
Beispiel #9
0
otError JoinerRouter::DelaySendingJoinerEntrust(const Ip6::MessageInfo &aMessageInfo, const JoinerRouterKekTlv &aKek)
{
    ThreadNetif &    netif = GetNetif();
    otError          error;
    Coap::Message *  message = NULL;
    Ip6::MessageInfo messageInfo;
    Dataset          dataset(MeshCoP::Tlv::kActiveTimestamp);

    NetworkMasterKeyTlv   masterKey;
    MeshLocalPrefixTlv    meshLocalPrefix;
    ExtendedPanIdTlv      extendedPanId;
    NetworkNameTlv        networkName;
    NetworkKeySequenceTlv networkKeySequence;
    const Tlv *           tlv;

    DelayedJoinEntHeader delayedMessage;

    VerifyOrExit((message = NewMeshCoPMessage(netif.GetCoap())) != NULL, error = OT_ERROR_NO_BUFS);

    message->Init(OT_COAP_TYPE_CONFIRMABLE, OT_COAP_CODE_POST);
    message->AppendUriPathOptions(OT_URI_PATH_JOINER_ENTRUST);
    message->SetPayloadMarker();
    message->SetSubType(Message::kSubTypeJoinerEntrust);

    masterKey.Init();
    masterKey.SetNetworkMasterKey(netif.GetKeyManager().GetMasterKey());
    SuccessOrExit(error = message->Append(&masterKey, sizeof(masterKey)));

    meshLocalPrefix.Init();
    meshLocalPrefix.SetMeshLocalPrefix(netif.GetMle().GetMeshLocalPrefix());
    SuccessOrExit(error = message->Append(&meshLocalPrefix, sizeof(meshLocalPrefix)));

    extendedPanId.Init();
    extendedPanId.SetExtendedPanId(netif.GetMac().GetExtendedPanId());
    SuccessOrExit(error = message->Append(&extendedPanId, sizeof(extendedPanId)));

    networkName.Init();
    networkName.SetNetworkName(netif.GetMac().GetNetworkName());
    SuccessOrExit(error = message->Append(&networkName, sizeof(Tlv) + networkName.GetLength()));

    netif.GetActiveDataset().Get(dataset);
    if ((tlv = dataset.Get(Tlv::kActiveTimestamp)) != NULL)
    {
        SuccessOrExit(error = message->Append(tlv, sizeof(Tlv) + tlv->GetLength()));
    }
    else
    {
        ActiveTimestampTlv activeTimestamp;
        activeTimestamp.Init();
        SuccessOrExit(error = message->Append(&activeTimestamp, sizeof(activeTimestamp)));
    }

    if ((tlv = dataset.Get(Tlv::kChannelMask)) != NULL)
    {
        SuccessOrExit(error = message->Append(tlv, sizeof(Tlv) + tlv->GetLength()));
    }
    else
    {
        ChannelMaskBaseTlv channelMask;
        channelMask.Init();
        SuccessOrExit(error = message->Append(&channelMask, sizeof(channelMask)));
    }

    if ((tlv = dataset.Get(Tlv::kPSKc)) != NULL)
    {
        SuccessOrExit(error = message->Append(tlv, sizeof(Tlv) + tlv->GetLength()));
    }
    else
    {
        PSKcTlv pskc;
        pskc.Init();
        SuccessOrExit(error = message->Append(&pskc, sizeof(pskc)));
    }

    if ((tlv = dataset.Get(Tlv::kSecurityPolicy)) != NULL)
    {
        SuccessOrExit(error = message->Append(tlv, sizeof(Tlv) + tlv->GetLength()));
    }
    else
    {
        SecurityPolicyTlv securityPolicy;
        securityPolicy.Init();
        SuccessOrExit(error = message->Append(&securityPolicy, sizeof(securityPolicy)));
    }

    networkKeySequence.Init();
    networkKeySequence.SetNetworkKeySequence(netif.GetKeyManager().GetCurrentKeySequence());
    SuccessOrExit(error = message->Append(&networkKeySequence, networkKeySequence.GetSize()));

    messageInfo = aMessageInfo;
    messageInfo.SetPeerPort(kCoapUdpPort);

    delayedMessage = DelayedJoinEntHeader(TimerMilli::GetNow() + kDelayJoinEnt, messageInfo, aKek.GetKek());
    SuccessOrExit(delayedMessage.AppendTo(*message));
    mDelayedJoinEnts.Enqueue(*message);

    if (!mTimer.IsRunning())
    {
        mTimer.Start(kDelayJoinEnt);
    }

exit:

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

    return error;
}
Beispiel #10
0
void JoinerRouter::HandleRelayTransmit(Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
{
    OT_UNUSED_VARIABLE(aMessageInfo);

    otError            error;
    JoinerUdpPortTlv   joinerPort;
    JoinerIidTlv       joinerIid;
    JoinerRouterKekTlv kek;
    uint16_t           offset;
    uint16_t           length;
    Message *          message  = NULL;
    otMessageSettings  settings = {false, static_cast<otMessagePriority>(kMeshCoPMessagePriority)};
    Ip6::MessageInfo   messageInfo;

    VerifyOrExit(aMessage.GetType() == OT_COAP_TYPE_NON_CONFIRMABLE && aMessage.GetCode() == OT_COAP_CODE_POST,
                 error = OT_ERROR_DROP);

    otLogInfoMeshCoP("Received relay transmit");

    SuccessOrExit(error = Tlv::GetTlv(aMessage, Tlv::kJoinerUdpPort, sizeof(joinerPort), joinerPort));
    VerifyOrExit(joinerPort.IsValid(), error = OT_ERROR_PARSE);

    SuccessOrExit(error = Tlv::GetTlv(aMessage, Tlv::kJoinerIid, sizeof(joinerIid), joinerIid));
    VerifyOrExit(joinerIid.IsValid(), error = OT_ERROR_PARSE);

    SuccessOrExit(error = Tlv::GetValueOffset(aMessage, Tlv::kJoinerDtlsEncapsulation, offset, length));

    VerifyOrExit((message = mSocket.NewMessage(0, &settings)) != NULL, error = OT_ERROR_NO_BUFS);

    while (length)
    {
        uint16_t copyLength = length;
        uint8_t  tmp[16];

        if (copyLength >= sizeof(tmp))
        {
            copyLength = sizeof(tmp);
        }

        aMessage.Read(offset, copyLength, tmp);
        SuccessOrExit(error = message->Append(tmp, copyLength));

        offset += copyLength;
        length -= copyLength;
    }

    aMessage.CopyTo(offset, 0, length, *message);

    messageInfo.mPeerAddr.mFields.m16[0] = HostSwap16(0xfe80);
    memcpy(messageInfo.mPeerAddr.mFields.m8 + 8, joinerIid.GetIid(), 8);
    messageInfo.SetPeerPort(joinerPort.GetUdpPort());
    messageInfo.SetInterfaceId(GetNetif().GetInterfaceId());

    SuccessOrExit(error = mSocket.SendTo(*message, messageInfo));

    if (Tlv::GetTlv(aMessage, Tlv::kJoinerRouterKek, sizeof(kek), kek) == OT_ERROR_NONE)
    {
        otLogInfoMeshCoP("Received kek");

        DelaySendingJoinerEntrust(messageInfo, kek);
    }

exit:
    if (error != OT_ERROR_NONE && message != NULL)
    {
        message->Free();
    }
}
Beispiel #11
0
otError EnergyScanClient::SendQuery(uint32_t                           aChannelMask,
                                    uint8_t                            aCount,
                                    uint16_t                           aPeriod,
                                    uint16_t                           aScanDuration,
                                    const Ip6::Address &               aAddress,
                                    otCommissionerEnergyReportCallback aCallback,
                                    void *                             aContext)
{
    ThreadNetif &                     netif = GetNetif();
    otError                           error = OT_ERROR_NONE;
    MeshCoP::CommissionerSessionIdTlv sessionId;
    MeshCoP::ChannelMaskTlv           channelMask;
    MeshCoP::CountTlv                 count;
    MeshCoP::PeriodTlv                period;
    MeshCoP::ScanDurationTlv          scanDuration;
    Ip6::MessageInfo                  messageInfo;
    Coap::Message *                   message = NULL;

    VerifyOrExit(netif.GetCommissioner().IsActive(), error = OT_ERROR_INVALID_STATE);
    VerifyOrExit((message = MeshCoP::NewMeshCoPMessage(netif.GetCoap())) != NULL, error = OT_ERROR_NO_BUFS);

    message->Init(aAddress.IsMulticast() ? OT_COAP_TYPE_NON_CONFIRMABLE : OT_COAP_TYPE_CONFIRMABLE, OT_COAP_CODE_POST);
    message->SetToken(Coap::Message::kDefaultTokenLength);
    message->AppendUriPathOptions(OT_URI_PATH_ENERGY_SCAN);
    message->SetPayloadMarker();

    sessionId.Init();
    sessionId.SetCommissionerSessionId(netif.GetCommissioner().GetSessionId());
    SuccessOrExit(error = message->Append(&sessionId, sizeof(sessionId)));

    channelMask.Init();
    channelMask.SetChannelPage(OT_RADIO_CHANNEL_PAGE);
    channelMask.SetMask(aChannelMask);
    SuccessOrExit(error = message->Append(&channelMask, sizeof(channelMask)));

    count.Init();
    count.SetCount(aCount);
    SuccessOrExit(error = message->Append(&count, sizeof(count)));

    period.Init();
    period.SetPeriod(aPeriod);
    SuccessOrExit(error = message->Append(&period, sizeof(period)));

    scanDuration.Init();
    scanDuration.SetScanDuration(aScanDuration);
    SuccessOrExit(error = message->Append(&scanDuration, sizeof(scanDuration)));

    messageInfo.SetSockAddr(netif.GetMle().GetMeshLocal16());
    messageInfo.SetPeerAddr(aAddress);
    messageInfo.SetPeerPort(kCoapUdpPort);
    messageInfo.SetInterfaceId(netif.GetInterfaceId());
    SuccessOrExit(error = netif.GetCoap().SendMessage(*message, messageInfo));

    otLogInfoMeshCoP("sent energy scan query");

    mCallback = aCallback;
    mContext  = aContext;

exit:

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

    return error;
}
Beispiel #12
0
void Client::HandleRetransmissionTimer(void)
{
    uint32_t now = otPlatAlarmGetNow();
    uint32_t nextDelta = 0xffffffff;
    RequestMetadata requestMetadata;
    Message *message = mPendingRequests.GetHead();
    Message *nextMessage = NULL;
    Ip6::MessageInfo messageInfo;

    while (message != NULL)
    {
        nextMessage = message->GetNext();
        requestMetadata.ReadFrom(*message);

        if (requestMetadata.IsLater(now))
        {
            // Calculate the next delay and choose the lowest.
            if (requestMetadata.mNextTimerShot - now < nextDelta)
            {
                nextDelta = requestMetadata.mNextTimerShot - now;
            }
        }
        else if ((requestMetadata.mConfirmable) &&
                 (requestMetadata.mRetransmissionCount < kMaxRetransmit))
        {
            // Increment retransmission counter and timer.
            requestMetadata.mRetransmissionCount++;
            requestMetadata.mRetransmissionTimeout *= 2;
            requestMetadata.mNextTimerShot = now + requestMetadata.mRetransmissionTimeout;
            requestMetadata.UpdateIn(*message);

            // Check if retransmission time is lower than current lowest.
            if (requestMetadata.mRetransmissionTimeout < nextDelta)
            {
                nextDelta = requestMetadata.mRetransmissionTimeout;
            }

            // Retransmit
            if (!requestMetadata.mAcknowledged)
            {
                messageInfo.SetPeerAddr(requestMetadata.mDestinationAddress);
                messageInfo.SetPeerPort(requestMetadata.mDestinationPort);
                messageInfo.SetSockAddr(requestMetadata.mSourceAddress);

                SendCopy(*message, messageInfo);
            }
        }
        else
        {
            // No expected response or acknowledgment.
            FinalizeCoapTransaction(*message, requestMetadata, NULL, NULL, NULL, kThreadError_ResponseTimeout);
        }

        message = nextMessage;
    }

    if (nextDelta != 0xffffffff)
    {
        mRetransmissionTimer.Start(nextDelta);
    }
}