log_in_vain:
log_in_vain turns on logging for packets to ports for which
there is no listener.
rc.sysctl:
A generic way to set sysctl values. It reads /etc/syslog.conf
and sets values based on that. No /etc/syslog.conf has been
checked in yet, and I've not added this to the makefile yet
until I get more feedback.
Reviewed by: -current, -hackers and bde especially