# $OpenBSD: ifstated.conf,v 1.2 2018/01/20 23:07:58 mpf Exp $
# This is a sample config for a pair of firewalls with three physical interfaces
#
# The two firefall interfaces are made redundant on each side using 
# carp0 and carp1.
#
# A third interface em2 connects each firewall to the DMZ where it can
# reach a syslog server with the IP 192.168.1.10
# 
# This config does two things:
#  1. Monitor the reachability of the syslog server and demote
#     the carp interface group to provoke a failover if the syslog server
#     is not reachable. We do that by using ping(1) and checking
#     the link state of em2.
#  2. Log carp failovers


dmz_if_up = 'em2.link.up'
dmz_if_down = 'em2.link.down'

syslog_ok = '"ping -q -c 1 -w 1 192.168.1.10 >/dev/null 2>&1" every 10'

# ifstated starts up with the first defined state
state neutral {
	if $dmz_if_down {
		run "logger -st ifstated 'interface to syslog server em2 is down'"
		set-state demoted
	}
	if ! $syslog_ok {
		run "logger -st ifstated 'could not reach syslog server'"
		set-state demoted
	}
}

state demoted {
	init {
		run "ifconfig -g carp carpdemote" 
	}
	if $dmz_if_up && $syslog_ok {
		run "logger -st ifstated 'syslog server is ok again'"
		# remove our carp demotion
		run "ifconfig -g carp -carpdemote" 
		set-state neutral
	}
}

# commands in the global scope are always run
if carp0.link.up
	run "logger -st ifstated 'carp0 is master'"
if carp0.link.down
	run "logger -st ifstated 'carp0 is backup'"