Netifd supports IP rule declarations which are required to implement policy routing.
IPv4 rules can be defined by declaring one or more sections of type rule, IPv6 rules are denoted by sections of type rule6. Both types share the same set of defined options.

A simple IPv4 rule may look like:

config rule
	option mark   '0xFF'
        option in     'lan'
	option dest   '172.16.0.0/16'
	option lookup '100'

• 0xFF is a fwmark to be matched
• lan is the incoming logical interface name
• 172.16.0.0/16 is the destination subnet to match
• 100 is the routing table ID to use for the matched traffic

Similary, an IPv6 rule looks like:

config rule6
        option in     'vpn'
	option dest   'fdca:1234::/64'
	option action 'prohibit'

• vpn is the incoming logical interface name
• fdca:1234::/64 is the destination subnet to match
• prohibit is a routing action to take