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EthernetMacsecSecureEntity::RegisterOnBeforeSendMKPDU

CAPL Functions » Ethernet » Function Overview » EthernetMacsecSecureEntity::RegisterOnBeforeSendMKPDU Valid for: CANoe DE

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Method Syntax

byte EthernetMacsecSecureEntity.RegisterOnBeforeSendMKPDU(functionPtr callback);

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Description

Register a callback function which is called each time before the MKA key server sends a MKPDU (EAPOL-MKA frame). The callback function must have the following signature: 
dword OnBeforeSendMKPDU(EthernetMacsecSecureEntity, EthernetPacket*)
The callback function may manipulate the frame freely. The result value from the callback function determines whether the frame will actually be sent or discarded: returning 0 will cause the frame to be discarded, otherwise the frame will be sent. Note that the ICV needs to be recalculated if the frame has been modified in the callback. Any number of callback functions can be registered for a physical port’s secure entity. The execution order of the callback functions is not determined. Whenever a registered callback returns 0, execution stops and the remaining callbacks will not be called. Thus, these callback functions shall not rely on side effects of each other. There is no way to unregister a callback function, other than stopping measurement.

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Parameters

  • callback: The callback function to be registered.

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Return Values

  • byte: 1 if the call succeeded, 0 otherwise.

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Example

EthernetMacsecSecureEntity secY1;
secY1 = ethGetMacsecSecureEntity(ethernetport::Ethernet1::Port1);
if (secY1.isValid)
{
  secY1.RegisterOnBeforeSendMKPDU(ProcessMKPDU);
}

dword ProcessMKPDU(EthernetMacsecSecureEntity secy, EthernetPacket* packet)
{
  if (packet.mka.IsAvailable())
  {
    // invert the bytes of the MKPDU’s ICV
    byte disturbData[16];
    int i;
    packet.mka.icv.GetData(0, disturbData, 16);
    for (i=0;i<16;i++)
    {
      disturbData[i] = ~disturbData[i];
    }
    packet.mka.icv.SetData(0, disturbData, 16);
  }
  return 1; // MKPDU shall be transmitted
}