Open but shut: pf.conf

/etc/pf.conf

ext_if = "re0"
int_if = "ath0"
auth_web="192.168.27.20"
dhcp_services = "{ bootps, bootpc }" # DHCP server + client
table <authpf_users> persist 
pass in quick on $int_if proto tcp from ! <authpf_users> to port http rdr-to $auth_web
match out on $ext_if from $int_if:network nat-to ($ext_if)
anchor "authpf/*"
block all
pass quick on $int_if inet proto { tcp, udp } to $int_if port $dhcp_services
pass quick inet proto { tcp, udp } from $int_if:network to any port domain
pass quick on $int_if inet proto { tcp, udp } to $int_if port ssh

Pre-4.7:

ext_if = "re0"
int_if = "ath0"
auth_web="192.168.27.20"
dhcp_services = "{ bootps, bootpc }" # DHCP server + client
table <authpf_users> persist 
rdr pass on $int_if proto tcp from ! <authpf_users> to any port http -> $auth_web
nat on $ext_if from $localnet to any -> ($ext_if)
nat-anchor "authpf/*"
rdr-anchor "authpf/*"
binat-anchor "authpf/*"
anchor "authpf/*"
block all
pass quick on $int_if inet proto { tcp, udp } to $int_if port $dhcp_services
pass quick inet proto { tcp, udp } from $int_if:network to port domain
pass quick on $int_if inet proto { tcp, udp } to $int_if port ssh