/// <summary>
/// Adds broadcast/mesh headers and sends SDU to MAC
/// </summary>
/// <returns>True on success</returns>
private void SendData(
UInt16 orgAddr,
UInt16 tgtAddr,
UInt16 nextHopAddr,
ref Frame sdu,
Byte sduHandle,
DataConfirmHandler handler)
{
bool success = false;
if (orgAddr != cInvalidShortAddr)
{
bool ok = true;
bool multicast = false;
if (IsMulticast(tgtAddr))
{
multicast = true;
Messages6LoWPAN.BroadcastHeader bh = new Messages6LoWPAN.BroadcastHeader();
bh.seqNo = IncSeqNoBroadcast();
ok = bh.WriteToFrameHeader(sdu);
}
if (ok && (multicast || (tgtAddr != nextHopAddr)))
{
// add mesh header
Messages6LoWPAN.MeshHeader mh = new Messages6LoWPAN.MeshHeader();
mh.originatorAddress = orgAddr;
mh.finalAddress = tgtAddr;
mh.HopsLeft = cDefaultHopLimit;
ok = mh.WriteToFrameHeader(sdu);
}
if (ok)
{
MacDataRequest(nextHopAddr, ref sdu, sduHandle, handler);
success = true;
}
}
Frame.Release(ref sdu);
if (!success && handler != null)
handler.Invoke(_net, sduHandle, Status.Busy);
}
private void HandleData(
UInt16 srcAddr,
UInt16 dstAddr,
ref Frame sdu)
{
Messages6LoWPAN.Dispatch dispatch;
if (!Messages6LoWPAN.GetType(sdu, out dispatch))
return;
bool consume = false; // receive locally
bool forward = false; // forward to another node
UInt16 origAddr = srcAddr; // originator
UInt16 targetAddr = dstAddr; // target
bool haveMeshHeader = false;
Messages6LoWPAN.MeshHeader mh = new Messages6LoWPAN.MeshHeader();
if (dispatch == Messages6LoWPAN.Dispatch.Mesh)
{
if (!mh.ReadFromFrameHeader(sdu) || !Messages6LoWPAN.GetType(sdu, out dispatch))
return;
haveMeshHeader = true;
origAddr = mh.originatorAddress;
targetAddr = mh.finalAddress;
}
bool haveBroadcastHeader = false;
Messages6LoWPAN.BroadcastHeader bh = new Messages6LoWPAN.BroadcastHeader();
if (dispatch == Messages6LoWPAN.Dispatch.IpPacket && bh.ReadFromFrameHeader(sdu))
{
haveBroadcastHeader = true;
bool usefull = _routingTable.CheckBroadcastSeqNo(origAddr, bh.seqNo) && (origAddr != _addrShort);
if (!usefull || !haveMeshHeader || !Messages6LoWPAN.GetType(sdu, out dispatch))
return;
}
bool multicast = IsMulticast(targetAddr);
consume = (targetAddr == _addrShort || multicast);
forward = (targetAddr != _addrShort || multicast) && haveMeshHeader && (mh.HopsLeft > 0);
if (forward)
{
mh.HopsLeft--;
// currently we always need to reallocate a frame to be forwarded, since mac header space is worst case assumption
Frame frame = Frame.GetFrame(_macHeader + Messages6LoWPAN.MeshHeader.cLengthMax + Messages6LoWPAN.BroadcastHeader.cLength,
sdu.LengthDataUsed + _macTailer);
frame.WriteToBack(sdu);
bool ok = true;
UInt16 nextHop;
if (multicast)
{
nextHop = cBroadcastShortAddr;
ok = haveBroadcastHeader && bh.WriteToFrameHeader(frame);
}
else
{
bool routeHasError;
ok = _routingTable.GetRoute(targetAddr, out nextHop, out routeHasError);
if (!ok || routeHasError)
{
SendRouteError(origAddr, targetAddr, !routeHasError);
}
}
ok &= mh.WriteToFrameHeader(frame);
if (ok)
{
MacDataRequest(nextHop, ref frame);
}
Frame.Release(ref frame);
}
if (consume)
{
if (dispatch == Messages6LoWPAN.Dispatch.NonLowPan)
{
Message.Type type;
if (Message.GetType(sdu, out type))
{
switch (type)
{
case Message.Type.Data:
{
Message.Data data = new Message.Data();
if (data.ReadFromFrameHeader(sdu))
{
_data.HandleDataIndication(origAddr, targetAddr, ref sdu);
}
break;
}
case Message.Type.DiscoveryReply:
{
Message.DiscoveryReply drep;
if (_isAddrServer && drep.ReadFromFrame(sdu))
{
_addrServer.HandleDiscoveryReply(origAddr);
}
break;
}
}
}
}
else
{ // must be 6LoWPAN frame
_data.HandleDataIndication6Low(origAddr, targetAddr, ref sdu);
}
}
Frame.Release(ref sdu);
}