IP_REASS_CHECK_OVERLAP macro

The IP reassembly code currently has the following limitations: - IP header options are not supported - fragments must not overlap (e.g. due to different routes), currently, overlapping or duplicate fragments are thrown away if IP_REASS_CHECK_OVERLAP=1 (the default)! @todo: work with IP header options Setting this to 0, you can turn off checking the fragments for overlapping regions. The code gets a little smaller. Only use this if you know that overlapping won't occur on your network!