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

   1 ### -*-m4-*-
   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 ### Packet classification.
  26
  27 ## Define the available network classes.
  28 m4_divert(42)m4_dnl
  29 defnetclass untrusted untrusted trusted
  30 defnetclass trusted untrusted trusted safe noloop
  31 defnetclass safe trusted safe noloop
  32 defnetclass noloop trusted safe
  33 m4_divert(-1)m4_dnl
  34
  35 ###--------------------------------------------------------------------------
  36 ### Network layout.
  37
  38 m4_divert(46)m4_dnl
  39 ## Networks and routing.
  40
  41 defiface $if_trusted \
  42         trusted:172.29.199.0/26 \
  43         safe:172.29.199.64/27 \
  44         untrusted:default
  45 defiface $if_untrusted \
  46         untrusted:172.29.198.0/24
  47 defvpn $if_vpn safe 172.29.199.128/27 \
  48         crybaby:172.29.199.129
  49 defiface $if_its_mz safe:172.29.199.160/30
  50 defiface $if_its_pi safe:192.168.0.0/24
  51
  52 m4_divert(60)m4_dnl
  53 ###--------------------------------------------------------------------------
  54 ### Special forwarding exemptions.
  55
  56 ## Allow ping from safe/noloop to untrusted networks.
  57 run iptables -A FORWARD -j ACCEPT \
  58         -p icmp ! -f --icmp-type echo-request \
  59         -m mark --mark $to_untrusted/$MASK_TO
  60 run iptables -A FORWARD -j ACCEPT \
  61         -p icmp ! -f --icmp-type echo-reply \
  62         -m mark --mark $from_untrusted/$MASK_FROM \
  63         -m state --state ESTABLISHED
  64
  65 ## Allow SSH from safe/noloop to untrusted networks.
  66 run iptables -A FORWARD -j ACCEPT \
  67         -p tcp ! -f --destination-port $port_ssh \
  68         -m mark --mark $to_untrusted/$MASK_TO
  69 run iptables -A FORWARD -j ACCEPT \
  70         -p tcp ! -f --source-port $port_ssh \
  71         -m mark --mark $from_untrusted/$MASK_FROM \
  72         -m state --state ESTABLISHED
  73
  74 m4_divert(80)m4_dnl
  75 ###--------------------------------------------------------------------------
  76 ### Locally-bound packet inspection.
  77
  78 clearchain inbound
  79
  80 ## Track connections.
  81 commonrules inbound
  82 conntrack inbound
  83
  84 ## Allow incoming bootp.  Bootp won't be forwarded, so this is obviously a
  85 ## local request.
  86 run iptables -A inbound -j ACCEPT \
  87         -s 0.0.0.0 -d 255.255.255.255 \
  88         -p udp --source-port $port_bootpc --destination-port $port_bootps
  89 run iptables -A inbound -j ACCEPT \
  90         -s 172.29.198.0/23 \
  91         -p udp --source-port $port_bootpc --destination-port $port_bootps
  92
  93 ## Allow incoming ping.  This is the only ICMP left.
  94 run iptables -A inbound -j ACCEPT -p icmp
  95
  96 m4_divert(88)m4_dnl
  97 ## Allow unusual things.
  98 openports inbound
  99
 100 ## Inspect inbound packets from untrusted sources.
 101 run iptables -A inbound -j forbidden
 102 run iptables -A INPUT -m mark --mark $from_untrusted/$MASK_FROM -g inbound
 103
 104 ## Otherwise process as indicated by the mark.
 105 for i in INPUT FORWARD; do
 106   run iptables -A $i -m mark ! --mark 0/$MASK_MASK -j ACCEPT
 107 done
 108
 109 m4_divert(-1)
 110 ###----- That's all, folks --------------------------------------------------