For low-level packet analysis use-cases, these fields are currently
not script-land accessible via raw_packet() or so. They are accessible
on the icmp_context record, but not on the actual ip4_hdr record, so
add them.
We previously computed the length of the Geneve options field
incorrectly which lead to us passing data at an incorrect offset to
inner analyzers. With this patch we now interpret the length field
correctly, according the the spec
https://datatracker.ietf.org/doc/html/rfc8926#section-3.4.
Closes#1726.
This patch adds the ability to decap Geneve packets to process the inner
payload. The structure of the analyzer borrows heavily from the VXLAN
analyzer.
