### -*-sh-*- ### ### Local firewall configuration ### ### (c) 2008 Mark Wooding ### ###----- Licensing notice --------------------------------------------------- ### ### This program is free software; you can redistribute it and/or modify ### it under the terms of the GNU General Public License as published by ### the Free Software Foundation; either version 2 of the License, or ### (at your option) any later version. ### ### This program is distributed in the hope that it will be useful, ### but WITHOUT ANY WARRANTY; without even the implied warranty of ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ### GNU General Public License for more details. ### ### You should have received a copy of the GNU General Public License ### along with this program; if not, write to the Free Software Foundation, ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ###-------------------------------------------------------------------------- ### Local configuration. m4_divert(6)m4_dnl ## Default NTP servers. defconf(ntp_servers, "81.187.26.174 90.155.23.205 2001:8b0:0:23::205 185.73.44.6 2001:ba8:0:2c06::") m4_divert(-1) ###-------------------------------------------------------------------------- ### Packet classification. ## IPv4 addressing. ## ## There are two small blocks of publicly routable IPv4 addresses, and a ## block of RFC1918 private-use addresses allocated from the Cambridge G-RIN. ## The former are as follows. ## ## 81.2.113.195, 81.187.238.128/28, 217.169.12.64/28 ## House border network (dmz). We have all of these; the loose ## address is for the router. ## ## The latter is the block 172.29.196.0/22. Currently the low half is ## unallocated (and may be returned to the G-RIN); the remaining addresses ## are allocated as follows. ## ## 172.29.198.0/24 Untrusted networks. ## .0/25 house wireless net ## .128/28 iodine (IP-over-DNS) network ## .144/28 hippotat (IP-over-HTTP) network ## .160/27 untrusted virtual network ## ## 172.29.199.0/24 Trusted networks. ## .0/25 house wired network ## .128/27 mobile VPN hosts ## .160/28 reserved, except .160/30 allocated for ITS ## .176/28 internal colocated network ## .192/27 house safe network ## .224/27 anycast services ## IPv6 addressing. ## ## There are five blocks of publicly routable IPv6 addresses, though some of ## them aren't very interesting. The ranges are as follows. ## ## 2001:8b0:c92::/48 ## Main house range (aaisp). See below for allocation policy. ## There is no explicit DMZ allocation (and no need for one). ## ## Addresses in the /64 networks are simply allocated in ascending order. ## The /48s are split into /64s by appending a 16-bit network number. The ## top nibble of the network number classifies the network, as follows. ## ## axxx Virtual, untrusted ## 8xxx Untrusted ## 6xxx Virtual, safe ## 4xxx Safe ## 0xxx Unsafe, trusted ## ## These have been chosen so that network properties can be deduced by ## inspecting bits of the network number: ## ## Bit 15 If set, the network is untrusted; otherwise it is trusted. ## Bit 14 If set, the network is safe; otherwise it is unsafe. ## ## Finally, the low-order nibbles identify the site. ## ## 0 No specific site: mobile VPN endpoints or anycast addresses. ## 1 House. ## fff Local border network. ## Define the available network classes. m4_divert(42)m4_dnl defnetclass scary scary trusted vpnnat mcast defnetclass untrusted scary untrusted trusted mcast defnetclass trusted scary untrusted trusted safe noloop vpnnat mcast defnetclass safe trusted safe noloop vpnnat mcast defnetclass noloop trusted safe mcast defnetclass vpnnat scary trusted safe mcast defnetclass link defnetclass mcast m4_divert(-1) m4_divert(26)m4_dnl ###-------------------------------------------------------------------------- ### Network layout. ## House networks. defnet dmz trusted addr 81.2.113.195 81.187.238.128/28 217.169.12.64/28 2001:8b0:c92:fff::/64 via unsafe untrusted defnet unsafe trusted addr 172.29.199.0/25 2001:8b0:c92:1::/64 via househub defnet safe safe addr 172.29.199.192/27 2001:8b0:c92:4001::/64 via househub defnet untrusted untrusted addr 172.29.198.0/25 2001:8b0:c92:8001::/64 via househub defnet househub virtual via housebdry dmz unsafe safe untrusted defnet housebdry virtual via househub hub ## House hosts. defhost radius hosttype router iface eth0 dmz unsafe safe untrusted vpn sgo default iface eth1 dmz unsafe safe untrusted vpn sgo default iface eth2 dmz unsafe safe untrusted vpn sgo iface eth3 unsafe untrusted vpn default iface ppp0 default iface t6-he default iface vpn-precision vpn sgo iface vpn-chiark sgo iface vpn-+ vpn defhost roadstar iface eth0 dmz unsafe iface eth1 dmz unsafe defhost jem iface eth0 dmz unsafe iface eth1 dmz unsafe defhost universe iface eth0 dmz unsafe iface eth1 dmz unsafe defhost artist hosttype router iface eth0 dmz unsafe untrusted iface eth1 dmz unsafe untrusted iface eth3 unsafe untrusted defhost vampire hosttype router iface eth0.4 dmz unsafe untrusted safe vpn sgo iface eth0.5 dmz unsafe untrusted safe vpn sgo iface eth0.6 dmz unsafe safe untrusted vpn sgo iface eth0.7 unsafe untrusted vpn iface vpn-precision vpn sgo iface vpn-chiark sgo iface vpn-+ vpn defhost ibanez iface br-dmz dmz unsafe iface br-unsafe unsafe defhost orange iface wlan0 untrusted iface vpn-radius unsafe defhost groove iface eth0 unsafe iface wlan0 untrusted iface vpn-radius unsafe defhost gibson hosttype client iface eth0 unsafe ## Formerly colocated hosts. defhost fender iface br-dmz dmz unsafe iface br-unsafe dmz unsafe defhost precision hosttype router iface eth0 dmz unsafe vpn sgo iface eth1 dmz unsafe vpn sgo iface vpn-mango binswood iface vpn-chiark sgo iface vpn-national upn iface vpn-mdwdev upn iface vpn-+ vpn defhost telecaster iface eth0 dmz unsafe vpn sgo iface eth1 dmz unsafe vpn sgo defhost stratocaster iface eth0 dmz unsafe vpn sgo iface eth1 dmz unsafe vpn sgo defhost jazz hosttype router iface eth0 dmz unsafe vpn sgo iface eth1 dmz unsafe vpn sgo iface dns0 iodine iface hippo-svc hippotat iface vpn-+ vpn ## Stunt connectivity networks. defnet iodine untrusted addr 172.29.198.128/28 via colohub defnet hippotat untrusted addr 172.29.198.144/28 via colohub ## Other networks. defnet hub virtual via housebdry defnet sgo noloop addr !172.29.198.0/23 addr !10.165.27.0/24 addr 10.0.0.0/8 addr 172.16.0.0/12 addr 192.168.0.0/16 via househub defnet vpn trusted addr 172.29.199.128/27 2001:8b0:c92:6000::/64 via househub host crybaby 1 ::1:1 host terror 2 ::2:1 host orange 3 ::3:1 host haze 4 ::4:1 host spirit 9 ::9:1 host groove 10 ::10:1 defnet anycast trusted addr 172.29.199.224/27 2001:8b0:c92:0::/64 via dmz unsafe safe untrusted vpn nvpn defnet default scary addr 81.2.113.195 81.187.238.128/28 217.169.12.64/28 \ 2001:8b0:c92::/48 via dmz unsafe untrusted defnet upn untrusted addr 172.29.198.160/27 2001:8b0:c92:a000::/64 via househub host national 1 ::1:1 host mdwdev 2 ::2:1 ## Linode hosts. defhost national iface eth0 default iface vpn-precision househub ## Satellite networks. defnet binswood vpnnat addr 10.165.27.0/24 via househub defhost mango hosttype router iface eth0 binswood default iface vpn-precision dmz default m4_divert(80)m4_dnl ###-------------------------------------------------------------------------- ### Connection tracking helper modules. for i in ftp; do modprobe nf_conntrack_$i done m4_divert(80)m4_dnl ###-------------------------------------------------------------------------- ### Special forwarding exemptions. case $forward in 1) ## Only allow these packets if they're not fragmented. (Don't trust safe ## hosts's fragment reassembly to be robust against malicious fragments.) ## There's a hideous bug in iptables 1.4.11.1 which botches the meaning ## of `! -f', so we do the negation using early return from a subchain. clearchain fwd-spec-nofrag run iptables -A fwd-spec-nofrag -j RETURN --fragment run ip6tables -A fwd-spec-nofrag -j RETURN \ -m ipv6header --soft --header frag run ip46tables -A FORWARD -j fwd-spec-nofrag ## Allow ping from safe/noloop to untrusted networks. run iptables -A fwd-spec-nofrag -j ACCEPT \ -p icmp --icmp-type echo-request \ -m mark --mark $to_untrusted/$MASK_TO run iptables -A fwd-spec-nofrag -j ACCEPT \ -p icmp --icmp-type echo-reply \ -m mark --mark $from_untrusted/$MASK_FROM \ -m state --state ESTABLISHED run ip6tables -A fwd-spec-nofrag -j ACCEPT \ -p icmpv6 --icmpv6-type echo-request \ -m mark --mark $to_untrusted/$MASK_TO run ip6tables -A fwd-spec-nofrag -j ACCEPT \ -p icmpv6 --icmpv6-type echo-reply \ -m mark --mark $from_untrusted/$MASK_FROM \ -m state --state ESTABLISHED ## Allow SSH from safe/noloop to untrusted networks. run ip46tables -A fwd-spec-nofrag -j ACCEPT \ -p tcp --destination-port $port_ssh \ -m mark --mark $to_untrusted/$MASK_TO run ip46tables -A fwd-spec-nofrag -j ACCEPT \ -p tcp --source-port $port_ssh \ -m mark --mark $from_untrusted/$MASK_FROM \ -m state --state ESTABLISHED ;; esac m4_divert(80)m4_dnl ###-------------------------------------------------------------------------- ### Kill things we don't understand properly. ### ### I don't like having to do this, but since I don't know how to do proper ### multicast filtering, I'm just going to ban it from being forwarded. errorchain poorly-understood REJECT ## Ban multicast destination addresses in forwarding. case $forward in 1) run iptables -A FORWARD -g poorly-understood \ -d 224.0.0.0/4 run ip6tables -A FORWARD -g poorly-understood \ -d ff::/8 ;; esac m4_divert(82)m4_dnl ###-------------------------------------------------------------------------- ### Check for source routing. clearchain check-srcroute run iptables -A check-srcroute -g forbidden \ -m ipv4options --any --flags lsrr,ssrr run ip6tables -A check-srcroute -g forbidden \ -m rt for c in INPUT FORWARD; do for m in $from_scary $from_untrusted; do run ip46tables -A $c -m mark --mark $m/$MASK_FROM -j check-srcroute done done m4_divert(84)m4_dnl ###-------------------------------------------------------------------------- ### Locally-bound packet inspection. clearchain inbound clearchain inbound-untrusted ## Track connections. commonrules inbound conntrack inbound ## Allow incoming bootp. Bootp won't be forwarded, so this is obviously a ## local request. run iptables -A inbound -j ACCEPT \ -s 0.0.0.0 -d 255.255.255.255 \ -p udp --source-port $port_bootpc --destination-port $port_bootps run iptables -A inbound -j ACCEPT \ -s 172.29.198.0/23 \ -p udp --source-port $port_bootpc --destination-port $port_bootps ## Allow incoming ping. This is the only ICMP left. run iptables -A inbound -j ACCEPT -p icmp run ip6tables -A inbound -j ACCEPT -p icmpv6 m4_divert(88)m4_dnl ## Allow unusual things. openports inbound ## Inspect inbound packets from untrusted sources. run iptables -A inbound -s 172.29.198.0/24 -g inbound-untrusted run ip6tables -A inbound -s 2001:8b0:c92:8000::/49 -g inbound-untrusted run ip46tables -A inbound-untrusted -g forbidden run ip46tables -A inbound -g forbidden run ip46tables -A INPUT -m mark --mark $from_scary/$MASK_FROM -g inbound run ip46tables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound ## Allow responses from the scary outside world into the untrusted net, but ## don't let untrusted things run services. case $forward in 1) run ip46tables -A FORWARD -j ACCEPT \ -m mark --mark $(( $from_scary | $to_untrusted ))/$(( $MASK_FROM | $MASK_TO )) \ -m state --state ESTABLISHED,RELATED ;; esac ## Otherwise process as indicated by the mark. for i in $inchains; do run ip46tables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT done m4_divert(-1) ###----- That's all, folks --------------------------------------------------