X-Git-Url: https://git.distorted.org.uk/~mdw/firewall/blobdiff_plain/bfdc045deb6149808d309b4ac3c292d9c57a8b38..e66833d3112cbea68ae6dfedeb59158ebc6bacd5:/local.m4 diff --git a/local.m4 b/local.m4 index 56c2253..9d4d917 100644 --- a/local.m4 +++ b/local.m4 @@ -1,4 +1,4 @@ -### -*-m4-*- +### -*-sh-*- ### ### Local firewall configuration ### @@ -22,6 +22,15 @@ ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ###-------------------------------------------------------------------------- +### Local configuration. + +m4_divert(6)m4_dnl +## Default NTP servers. +defconf(ntp_servers, + "158.152.1.76 158.152.1.204 194.159.253.2 195.173.57.232") + +m4_divert(-1) +###-------------------------------------------------------------------------- ### Packet classification. ## Define the available network classes. @@ -30,54 +39,191 @@ defnetclass untrusted untrusted trusted defnetclass trusted untrusted trusted safe noloop defnetclass safe trusted safe noloop defnetclass noloop trusted safe -m4_divert(-1)m4_dnl +m4_divert(-1) +m4_divert(26)m4_dnl ###-------------------------------------------------------------------------- ### Network layout. -m4_divert(46)m4_dnl -## Networks and routing. - -defiface $if_trusted \ - trusted:172.29.199.0/26 \ - safe:172.29.199.64/27 \ - untrusted:default -defiface $if_untrusted \ - untrusted:172.29.198.0/24 -defvpn $if_vpn safe 172.29.199.128/27 \ - crybaby:172.29.199.129 -defiface $if_its_mz safe:172.29.199.160/30 -defiface $if_its_pi safe:192.168.0.0/24 - -m4_divert(60)m4_dnl +## House networks. +defnet dmz trusted + addr 62.49.204.144/28 + forwards unsafe untrusted +defnet unsafe trusted + addr 172.29.199.0/25 + forwards househub +defnet safe safe + addr 172.29.199.192/28 + forwards househub +defnet untrusted untrusted + addr 172.29.198.0/25 + forwards househub +defnet vpn safe + addr 172.29.199.128/27 + forwards househub colohub + host crybaby 1 + host terror 2 +defnet iodine untrusted + addr 172.29.198.128/28 + +defnet househub virtual + forwards housebdry dmz unsafe safe untrusted +defnet housebdry virtual + forwards househub hub + noxit dmz + +## House hosts. +defhost radius + router + iface eth0 dmz unsafe safe + iface eth1 dmz unsafe safe + iface eth2 safe + iface eth3 untrusted +defhost roadstar + iface eth0 dmz unsafe + iface eth1 dmz unsafe +defhost jem + iface eth0 dmz unsafe + iface eth1 dmz unsafe +defhost artist + iface eth0 dmz unsafe + iface eth1 dmz unsafe +defhost vampire + router + iface eth0.0 dmz unsafe safe + iface eth0.1 dmz unsafe safe + iface eth0.2 safe + iface eth0.3 untrusted + iface dns0 dns + iface vpn-+ vpn + iface vpn-precision colobdry vpn +defhost ibanez + iface br-dmz dmz unsafe + iface br-unsafe unsafe + +defhost gibson + iface eth0 unsafe + +## Colocated networks. +defnet jump trusted + addr 212.13.198.64/28 + forwards colohub +defnet colo trusted + addr 172.29.199.176/28 + forwards colohub +defnet colohub virtual + forwards colobdry jump colo +defnet colobdry virtual + forwards colohub hub + noxit jump + +## Colocated hosts. +defhost fender + iface br-jump jump colo + iface br-colo jump colo +defhost precision + router + iface eth0 jump colo + iface eth1 jump colo + iface vpn-+ vpn + iface vpn-vampire housebdry vpn +defhost telecaster + iface eth0 jump colo + iface eth1 jump colo +defhost stratocaster + iface eth0 jump colo + iface eth1 jump colo +defhost jazz + iface eth0 jump colo + iface eth1 jump colo + +## Other networks. +defnet hub virtual + forwards housebdry colobdry +defnet default untrusted + addr 62.49.204.144/28 + addr 212.13.198.64/28 + forwards dmz untrusted unsafe jump colo + +m4_divert(80)m4_dnl ###-------------------------------------------------------------------------- ### Special forwarding exemptions. -## Allow ping from safe/noloop to untrusted networks. -run iptables -A FORWARD -j ACCEPT \ - -p icmp --icmp-type echo-request \ - -m mark --mark $to_untrusted/$MASK_TO -run iptables -A FORWARD -j ACCEPT \ - -p icmp --icmp-type echo-reply \ - -m mark --mark $from_untrusted/$MASK_FROM \ - -m state --state ESTABLISHED - -## Allow SSH from safe/noloop to untrusted networks. -run iptables -A FORWARD -j ACCEPT \ - -p tcp --destination-port $port_ssh \ - -m mark --mark $to_untrusted/$MASK_TO -run iptables -A FORWARD -j ACCEPT \ - -p tcp --source-port $port_ssh \ - -m mark --mark $from_untrusted/$MASK_FROM \ - -m state --state ESTABLISHED +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 iptables -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 ipv6-icmp --icmpv6-type echo-request \ + -m mark --mark $to_untrusted/$MASK_TO + run ip6tables -A fwd-spec-nofrag -j ACCEPT \ + -p ipv6-icmp --icmpv6-type echo-reply \ + -m mark --mark $from_untrusted/$MASK_FROM \ + -m state --state ESTABLISHED + + ## Allow SSH from safe/noloop to untrusted networks. + run iptables -A fwd-spec-nofrag -j ACCEPT \ + -p tcp --destination-port $port_ssh \ + -m mark --mark $to_untrusted/$MASK_TO + run iptables -A fwd-spec-nofrag -j ACCEPT \ + -p tcp --source-port $port_ssh \ + -m mark --mark $from_untrusted/$MASK_FROM \ + -m state --state ESTABLISHED + run ip6tables -A fwd-spec-nofrag -j ACCEPT \ + -p tcp --destination-port $port_ssh \ + -m mark --mark $to_untrusted/$MASK_TO + run ip6tables -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(84)m4_dnl +###-------------------------------------------------------------------------- ### Locally-bound packet inspection. clearchain inbound ## Track connections. +commonrules inbound conntrack inbound ## Allow incoming bootp. Bootp won't be forwarded, so this is obviously a @@ -89,21 +235,40 @@ run iptables -A inbound -j ACCEPT \ -s 172.29.198.0/23 \ -p udp --source-port $port_bootpc --destination-port $port_bootps +## Incoming multicast on a network interface associated with a trusted +## network is OK, since it must have originated there (or been forwarded, but +## we don't do that yet). +seen=:-: +for net in $allnets; do + eval class=\$net_class_$net + case $class in trusted) ;; *) continue ;; esac + for iface in $(net_interfaces FWHOST $net); do + case "$seen" in *:$iface:*) continue ;; esac + seen=$seen$iface: + run iptables -A inbound -j ACCEPT \ + -s 0.0.0.0 -d 224.0.0.0/24 \ + -i $iface + done +done + ## Allow incoming ping. This is the only ICMP left. -run iptables -A inbound -j ACCEPT -p icmp +run ip46tables -A inbound -j ACCEPT -p icmp m4_divert(88)m4_dnl ## Allow unusual things. openports inbound ## Inspect inbound packets from untrusted sources. -run iptables -A inbound -j forbidden -run iptables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound +run ip46tables -A inbound -j forbidden +run ip46tables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound ## Otherwise process as indicated by the mark. -for i in INPUT FORWARD; do - run iptables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT -done +run ip46tables -A INPUT -m mark ! --mark 0/$MASK_MASK -j ACCEPT +case $forward in + 1) + run ip46tables -A FORWARD -m mark ! --mark 0/$MASK_MASK -j ACCEPT + ;; +esac m4_divert(-1) ###----- That's all, folks --------------------------------------------------