/// <summary>
/// Encode command frame
/// </summary>
/// <param name="frame">target buffer</param>
/// <returns>True on success</returns>
public bool WriteToFrame(Frame frame)
{
if (frame == null || frame.LengthDataAvail < _lengthMax || frame.LengthDataUsed != 0)
return false;
frame.ReserveHeader(frame.LengthHeaderAvail + 1); // increase header space by one byte
frame.AllocBack(_lengthMax - 1); // reserve space without command type, so payload is at 0..n-1
EncodePayload(frame);
frame.AllocFront(1);
frame.Write(0, (byte)_type);
return true;
}
/// <summary>
/// Encodes the header into the front of the frame
/// </summary>
/// <param name="frame">The header is placed at the front of this frame</param>
/// <returns>True on success, false if the frame is too small or the header is invalid</returns>
public bool WriteToFrameHeader(Frame frame)
{
int len = Length();
if (frame.LengthHeaderAvail < len)
return false;
frame.AllocFront(len);
frame.WriteCanonical(0, fcs.Value);
frame.Write(2, seqNo);
int offset = 3;
AddressingMode dstMode = fcs.DstAddrMode;
AddressingMode srcMode = fcs.SrcAddrMode;
bool panIdCompression = fcs.PanIdCompression;
if (dstMode == AddressingMode.Reserved || srcMode == AddressingMode.Reserved ||
(panIdCompression && dstMode == AddressingMode.None))
return false;
if (dstMode != AddressingMode.None)
{ // dstPanId
frame.WriteCanonical(offset, dstPanId);
offset += 2;
}
if (dstMode == AddressingMode.Short)
{ // dstAddrShort
frame.WriteCanonical(offset, dstAddrShort);
offset += 2;
}
if (dstMode == AddressingMode.Extended)
{ // dstAddrShort
frame.WriteCanonical(offset, dstAddrExt);
offset += 8;
}
if (srcMode != AddressingMode.None && !panIdCompression)
{ // srcPanId
frame.WriteCanonical(offset, srcPanId);
offset += 2;
}
if (srcMode == AddressingMode.Short)
{ // dstAddrShort
frame.WriteCanonical(offset, srcAddrShort);
offset += 2;
}
if (srcMode == AddressingMode.Extended)
{ // dstAddrShort
frame.WriteCanonical(offset, srcAddrExt);
offset += 8;
}
// FIXME: secHeader
return true;
}
