# $NetBSD: host-npf.conf,v 1.12 2023/07/31 16:09:01 tsutsui Exp $
#
# Simple ruleset for a host with (i.e., not routing) two interfaces,
# ethernet and wifi.
#
# DHCP (v4 and v6), SLAAC, ICMPv6, ICMP echo requests, traceroute, mDNS traffic
# are permitted, inbound, on either interface.
#
# SSH to the host is allowed in via the ethernet interface.
# blacklistd(8) is used to prevent SSH bruteforce attempts.
#
# No specific rules for the wifi interface.
#
# All traffic from the host is permitted, outbound, on either interface.
#

$wired_if = "wm0"
$wifi_if  = "iwn0"
$wired_addrs= ifaddrs($wired_if)
$wifi_addrs = ifaddrs($wifi_if)

alg "icmp"

procedure "log" {
   # Send log events to npflog0, see npfd(8)
   log: npflog0
}

group "wired" on $wired_if {
   # Placeholder for blacklistd (configuration separate) to add blocked hosts
   ruleset "blacklistd"

   # Allow SSH on wired interface and log all connection attempts
   pass stateful in on $wired_if proto tcp to $wired_addrs port ssh apply "log"
}

group "wifi" on $wifi_if {

}

group default {
   # Default deny, otherwise last matching rule wins
   block all apply "log"

   # Don't block loopback
   pass on lo0 all

   # Allow incoming DHCP server responses
   pass in family inet4 proto udp from any port bootps to any port bootpc
   pass in family inet6 proto udp from any to any port "dhcpv6-client"

   # Allow IPv6 ICMP
   pass family inet6 proto ipv6-icmp all

   # Allow incoming IPv4 pings
   pass in family inet4 proto icmp icmp-type echo all

   # Allow being tracerouted
   pass in proto udp to any port 33434-33600

   # Allow incoming mDNS traffic from neighbours
   pass in proto udp to any port mdns

   # Allow all outbound traffic
   pass stateful out all
}