tag:
type: ipv4
help:  Set a static ARP translation
val_help: IPv4 destination address

#
# All the work is done here in the "end:" tag.  There are four possible cases:
#
#   1) A new node and possibly sub-tree with hwaddr has been created
#   2) Value of hwaddr node in sub-tree has been changed
#   3) The hwaddr node in sub-tree has been deleted
#   4) This node (and hence entire sub-tree) has been deleted
# 
# The flow is the same in all cases.  First, we delete any
# previous static ARP translation that may be in place for this
# IP addr.  This will typically fail in case (1) and in case (4) if the
# hwaddr node had been previously deleted.  Then, if a hwaddr is defined,
# we add a new startic ARP translation for this IP addr pointing to that
# hwaddr.  This should always succeed, so we don't try to hide error
# messages from the user.
# 
# We always force a successful return in order to prevent transient
# failures of the "arp" command from failing the commit.
# 
end:
	ipaddr=$VAR(@)
	hwaddr=$VAR(hwaddr/@)
	/usr/sbin/arp -d $ipaddr > /dev/null
	if [ -n "$hwaddr" ]; then
	    /usr/sbin/arp -s $ipaddr $hwaddr
	fi
	exit 0
