uint32_t SixLowPanHc1::Deserialize()

in simulation/src/sixlowpan/model/sixlowpan-header.cc [274:386]
105 lines of code
23 McCabe index (conditional complexity)

uint32_t SixLowPanHc1::Deserialize (Buffer::Iterator start)
{
  Buffer::Iterator i = start;
  uint32_t serializedSize = 3;

  uint8_t dispatch = i.ReadU8 ();
  if (dispatch != SixLowPanDispatch::LOWPAN_HC1)
    {
      return 0;
    }

  uint8_t encoding = i.ReadU8 ();
  m_hopLimit = i.ReadU8 ();

  m_srcCompression = LowPanHc1Addr_e (encoding >> 6);
  m_dstCompression = LowPanHc1Addr_e ( (encoding >> 4) & 0x3);
  m_tcflCompression = (encoding >> 3) & 0x1;
  m_nextHeaderCompression = LowPanHc1NextHeader_e ( (encoding >> 1) & 0x3);
  m_hc2HeaderPresent = encoding & 0x1;

  switch (m_srcCompression)
    {
    case HC1_PIII:
      for ( int j = 0; j < 8; j++)
        {
          m_srcPrefix[j] = i.ReadU8 ();
        }
      for ( int j = 0; j < 8; j++)
        {
          m_srcInterface[j] = i.ReadU8 ();
        }
      serializedSize += 16;
      break;
    case HC1_PIIC:
      for ( int j = 0; j < 8; j++)
        {
          m_srcPrefix[j] = i.ReadU8 ();
        }
      serializedSize += 8;
      break;
    case HC1_PCII:
      for ( int j = 0; j < 8; j++)
        {
          m_srcInterface[j] = i.ReadU8 ();
        }
      serializedSize += 8;
      break;
    case HC1_PCIC:
      break;
    }
  switch (m_dstCompression)
    {
    case HC1_PIII:
      for ( int j = 0; j < 8; j++)
        {
          m_dstPrefix[j] = i.ReadU8 ();
        }
      for ( int j = 0; j < 8; j++)
        {
          m_dstInterface[j] = i.ReadU8 ();
        }
      serializedSize += 16;
      break;
    case HC1_PIIC:
      for ( int j = 0; j < 8; j++)
        {
          m_dstPrefix[j] = i.ReadU8 ();
        }
      serializedSize += 8;
      break;
    case HC1_PCII:
      for ( int j = 0; j < 8; j++)
        {
          m_dstInterface[j] = i.ReadU8 ();
        }
      serializedSize += 8;
      break;
    case HC1_PCIC:
      break;
    }

  if ( m_tcflCompression == false )
    {
      m_trafficClass = i.ReadU8 ();
      uint8_t temp[3];
      i.Read (temp, 3);
      m_flowLabel = temp[2];
      m_flowLabel = (m_flowLabel << 8) | temp[1];
      m_flowLabel = (m_flowLabel << 8) | temp[0];
      serializedSize += 4;
    }

  switch ( m_nextHeaderCompression )
    {
    case HC1_NC:
      m_nextHeader = i.ReadU8 ();
      serializedSize++;
      break;
    case HC1_TCP:
      m_nextHeader = Ipv6Header::IPV6_TCP;
      break;
    case HC1_UDP:
      m_nextHeader = Ipv6Header::IPV6_UDP;
      break;
    case HC1_ICMP:
      m_nextHeader = Ipv6Header::IPV6_ICMPV6;
      break;
    }

  NS_ASSERT_MSG ( m_hc2HeaderPresent != true, "Can not compress HC2, exiting. Very sorry." );

  return GetSerializedSize ();
}