mdw@git.distorted.org.uk Git - firewall/blob - local.m4

   1 ### -*-sh-*-
   2 ###
   3 ### Local firewall configuration
   4 ###
   5 ### (c) 2008 Mark Wooding
   6 ###
   7
   8 ###----- Licensing notice ---------------------------------------------------
   9 ###
  10 ### This program is free software; you can redistribute it and/or modify
  11 ### it under the terms of the GNU General Public License as published by
  12 ### the Free Software Foundation; either version 2 of the License, or
  13 ### (at your option) any later version.
  14 ###
  15 ### This program is distributed in the hope that it will be useful,
  16 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ### GNU General Public License for more details.
  19 ###
  20 ### You should have received a copy of the GNU General Public License
  21 ### along with this program; if not, write to the Free Software Foundation,
  22 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23
  24 ###--------------------------------------------------------------------------
  25 ### Local configuration.
  26
  27 m4_divert(6)m4_dnl
  28 ## Default NTP servers.
  29 defconf(ntp_servers,
  30         "158.152.1.76 158.152.1.204 194.159.253.2 195.173.57.232")
  31
  32 m4_divert(-1)
  33 ###--------------------------------------------------------------------------
  34 ### Packet classification.
  35
  36 ## Define the available network classes.
  37 m4_divert(42)m4_dnl
  38 defnetclass untrusted untrusted trusted
  39 defnetclass trusted untrusted trusted safe noloop
  40 defnetclass safe trusted safe noloop
  41 defnetclass noloop trusted safe
  42 m4_divert(-1)
  43
  44 m4_divert(26)m4_dnl
  45 ###--------------------------------------------------------------------------
  46 ### Network layout.
  47
  48 ## House networks.
  49 defnet dmz trusted
  50         addr 62.49.204.144/28
  51         forwards unsafe untrusted
  52 defnet unsafe trusted
  53         addr 172.29.199.0/25
  54         forwards househub
  55 defnet safe safe
  56         addr 172.29.199.192/28
  57         forwards househub
  58 defnet untrusted untrusted
  59         addr 172.29.198.0/25
  60         forwards househub
  61 defnet vpn safe
  62         addr 172.29.199.128/27
  63         forwards househub
  64         host crybaby 1
  65         host terror 2
  66 defnet iodine untrusted
  67         addr 172.29.198.128/28
  68
  69 defnet househub virtual
  70         forwards housebdry dmz unsafe safe untrusted
  71 defnet housebdry virtual
  72         forwards househub hub
  73         noxit dmz
  74
  75 ## House hosts.
  76 defhost radius
  77         router
  78         iface eth0 dmz unsafe
  79         iface eth1 dmz unsafe
  80         iface eth2 safe
  81         iface eth3 untrusted
  82 defhost roadstar
  83         iface eth0 dmz unsafe
  84         iface eth1 dmz unsafe
  85 defhost jem
  86         iface eth0 dmz unsafe
  87         iface eth1 dmz unsafe
  88 defhost artist
  89         iface eth0 dmz unsafe
  90         iface eth1 dmz unsafe
  91 defhost vampire
  92         router
  93         iface eth0.0 dmz unsafe
  94         iface eth0.1 dmz unsafe
  95         iface eth0.3 untrusted
  96         iface dns0 dns
  97         iface vpn-+ vpn
  98         iface vpn-precision colobdry vpn
  99 defhost ibanez
 100         iface br-dmz dmz
 101         iface br-unsafe unsafe
 102
 103 defhost gibson
 104         iface eth0 unsafe
 105
 106 ## Colocated networks.
 107 defnet jump trusted
 108         addr 212.13.198.64/28
 109         forwards colohub
 110 defnet colo trusted
 111         addr 172.29.199.176/28
 112         forwards colohub
 113 defnet colohub virtual
 114         forwards colobdry jump colo
 115 defnet colobdry virtual
 116         forwards colohub hub
 117         noxit jump
 118
 119 ## Colocated hosts.
 120 defhost fender
 121         iface br-jump jump colo
 122         iface br-colo jump colo
 123 defhost precision
 124         router
 125         iface eth0 jump colo
 126         iface eth1 jump colo
 127         iface vpn-+ vpn
 128         iface vpn-vampire housebdry vpn
 129 defhost telecaster
 130         iface eth0 jump colo
 131         iface eth1 jump colo
 132 defhost stratocaster
 133         iface eth0 jump colo
 134         iface eth1 jump colo
 135 defhost jazz
 136         iface eth0 jump colo
 137         iface eth1 jump colo
 138
 139 ## Other networks.
 140 defnet hub virtual
 141         forwards housebdry colobdry
 142 defnet default untrusted
 143         addr 62.49.204.144/28
 144         addr 212.13.198.64/28
 145         forwards dmz untrusted unsafe jump colo
 146
 147 m4_divert(80)m4_dnl
 148 ###--------------------------------------------------------------------------
 149 ### Special forwarding exemptions.
 150
 151 case $forward in
 152   1)
 153
 154     ## Only allow these packets if they're not fragmented.  (Don't trust safe
 155     ## hosts's fragment reassembly to be robust against malicious fragments.)
 156     ## There's a hideous bug in iptables 1.4.11.1 which botches the meaning
 157     ## of `! -f', so we do the negation using early return from a subchain.
 158     clearchain fwd-spec-nofrag
 159     run iptables -A fwd-spec-nofrag -j RETURN --fragment
 160     run ip6tables -A fwd-spec-nofrag -j RETURN \
 161             -m ipv6header --soft --header frag
 162     run iptables -A FORWARD -j fwd-spec-nofrag
 163
 164     ## Allow ping from safe/noloop to untrusted networks.
 165     run iptables -A fwd-spec-nofrag -j ACCEPT \
 166             -p icmp --icmp-type echo-request \
 167             -m mark --mark $to_untrusted/$MASK_TO
 168     run iptables -A fwd-spec-nofrag -j ACCEPT \
 169             -p icmp --icmp-type echo-reply \
 170             -m mark --mark $from_untrusted/$MASK_FROM \
 171             -m state --state ESTABLISHED
 172     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 173             -p ipv6-icmp --icmpv6-type echo-request \
 174             -m mark --mark $to_untrusted/$MASK_TO
 175     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 176             -p ipv6-icmp --icmpv6-type echo-reply \
 177             -m mark --mark $from_untrusted/$MASK_FROM \
 178             -m state --state ESTABLISHED
 179
 180     ## Allow SSH from safe/noloop to untrusted networks.
 181     run iptables -A fwd-spec-nofrag -j ACCEPT \
 182             -p tcp --destination-port $port_ssh \
 183             -m mark --mark $to_untrusted/$MASK_TO
 184     run iptables -A fwd-spec-nofrag -j ACCEPT \
 185             -p tcp --source-port $port_ssh \
 186             -m mark --mark $from_untrusted/$MASK_FROM \
 187             -m state --state ESTABLISHED
 188     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 189             -p tcp --destination-port $port_ssh \
 190             -m mark --mark $to_untrusted/$MASK_TO
 191     run ip6tables -A fwd-spec-nofrag -j ACCEPT \
 192             -p tcp --source-port $port_ssh \
 193             -m mark --mark $from_untrusted/$MASK_FROM \
 194             -m state --state ESTABLISHED
 195
 196     ;;
 197 esac
 198
 199 m4_divert(80)m4_dnl
 200 ###--------------------------------------------------------------------------
 201 ### Kill things we don't understand properly.
 202 ###
 203 ### I don't like having to do this, but since I don't know how to do proper
 204 ### multicast filtering, I'm just going to ban it from being forwarded.
 205
 206 errorchain poorly-understood REJECT
 207
 208 ## Ban multicast destination addresses in forwarding.
 209 case $forward in
 210   1)
 211     run iptables -A FORWARD -g poorly-understood \
 212             -d 224.0.0.0/4
 213     run ip6tables -A FORWARD -g poorly-understood \
 214             -d ff::/8
 215     ;;
 216 esac
 217
 218 m4_divert(84)m4_dnl
 219 ###--------------------------------------------------------------------------
 220 ### Locally-bound packet inspection.
 221
 222 clearchain inbound
 223
 224 ## Track connections.
 225 commonrules inbound
 226 conntrack inbound
 227
 228 ## Allow incoming bootp.  Bootp won't be forwarded, so this is obviously a
 229 ## local request.
 230 run iptables -A inbound -j ACCEPT \
 231         -s 0.0.0.0 -d 255.255.255.255 \
 232         -p udp --source-port $port_bootpc --destination-port $port_bootps
 233 run iptables -A inbound -j ACCEPT \
 234         -s 172.29.198.0/23 \
 235         -p udp --source-port $port_bootpc --destination-port $port_bootps
 236
 237 ## Incoming multicast on a network interface associated with a trusted
 238 ## network is OK, since it must have originated there (or been forwarded, but
 239 ## we don't do that yet).
 240 seen=:-:
 241 for net in $allnets; do
 242   eval class=\$net_class_$net
 243   case $class in trusted) ;; *) continue ;; esac
 244   for iface in $(net_interfaces FWHOST $net); do
 245     case "$seen" in *:$iface:*) continue ;; esac
 246     seen=$seen$iface:
 247     run iptables -A inbound -j ACCEPT \
 248         -s 0.0.0.0 -d 224.0.0.0/24 \
 249         -i $iface
 250   done
 251 done
 252
 253 ## Allow incoming ping.  This is the only ICMP left.
 254 run ip46tables -A inbound -j ACCEPT -p icmp
 255
 256 m4_divert(88)m4_dnl
 257 ## Allow unusual things.
 258 openports inbound
 259
 260 ## Inspect inbound packets from untrusted sources.
 261 run ip46tables -A inbound -j forbidden
 262 run ip46tables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound
 263
 264 ## Otherwise process as indicated by the mark.
 265 run ip46tables -A INPUT -m mark ! --mark 0/$MASK_MASK -j ACCEPT
 266 case $forward in
 267   1)
 268     run ip46tables -A FORWARD -m mark ! --mark 0/$MASK_MASK -j ACCEPT
 269     ;;
 270 esac
 271
 272 m4_divert(-1)
 273 ###----- That's all, folks --------------------------------------------------