Added ConnState::Error to the connection state enum for ICMP error
packets. Added is_error detection for ICMPv4/v6 Dest Unreachable
and Time Exceeded types. When an ICMP error is detected, delegates
to track_icmp_error() which extracts the embedded original packet
tuple and relates it to an existing tracked connection (mirrors
Linux 7.1 nf_conntrack_icmp_error() in net/netfilter/nf_conntrack_proto_icmp.c).
Previously WIP — now committed to stabilize the base fork build.
Red Bear OS
b50fb644a9