OFP incorrectly assumes that packet headers are contigous in memory

[JannePeltonen]

ODP API does not guarantee that packet headers are contiguous in memory. odp_packet_l3_ptr() and friends can return the number of contiguous bytes in the underlying packet segment but OFP does not use the information.

This bug does not generally cause problems with the current ODP reference implementation but the situation may be different with future versions and with other ODP implementations.

[sovu]

TSC 23.01.18

Janne : detect packets that are not in contiguous memory and drop these packets.
Next step would be to move packets in contiguous memory and continue normal processing.

A different aproach would be to have a scratch table for the headers.