eBPF has a data type which is a per CPU array. By adding one element
to the array it is in fact added to all per CPU arrays in the kernel.
This allows to have a lockless structure in the kernel even when doing
counter update.
In userspace, we need to update the flow bypass code to fetch all
elements of the per CPU arrays.
This patch implements bypass capability for af-packet.
The filter only bypass TCP and UDP in IPv4 and IPv6. It don't
don't bypass IPv6 with extended headers.
This patch also introduces a bypassed flow manager that takes
care of timeouting the bypassed flows. It uses a 60 sec
timeout on flow. As they are supposed to be active we can
try that. If they are not active then we don't care to get them
back in Suricata.