config/firewall/ipsec-policy

   1 #!/bin/bash
   2 ###############################################################################
   3 #                                                                             #
   4 # IPFire.org - A linux based firewall                                         #
   5 # Copyright (C) 2015 IPFire Team                                              #
   6 #                                                                             #
   7 # This program is free software: you can redistribute it and/or modify        #
   8 # it under the terms of the GNU General Public License as published by        #
   9 # the Free Software Foundation, either version 3 of the License, or           #
  10 # (at your option) any later version.                                         #
  11 #                                                                             #
  12 # This program is distributed in the hope that it will be useful,             #
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of              #
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
  15 # GNU General Public License for more details.                                #
  16 #                                                                             #
  17 # You should have received a copy of the GNU General Public License           #
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
  19 #                                                                             #
  20 ###############################################################################
  21
  22 VPN_CONFIG="/var/ipfire/vpn/config"
  23
  24 eval $(/usr/local/bin/readhash /var/ipfire/vpn/settings)
  25
  26 VARS=(
  27         id status name lefthost type ctype psk local local_id leftsubnets
  28         remote_id remote rightsubnets x3 x4 x5 x6 x7 x8 x9 x10 x11 x12
  29         x13 x14 x15 x16 x17 x18 x19 proto x20 x21 x22
  30         route x23 mode interface_mode interface_address interface_mtu rest
  31 )
  32
  33 block_subnet() {
  34         local subnet="${1}"
  35         local action="${2}"
  36
  37         # Don't block a wildcard subnet
  38         if [ "${subnet}" = "0.0.0.0/0" ] || [ "${subnet}" = "0.0.0.0/0.0.0.0" ]; then
  39                 return 0
  40         fi
  41
  42         case "${action}" in
  43                 reject)
  44                         iptables -A IPSECBLOCK -d "${subnet}" -j REJECT --reject-with icmp-net-unreachable
  45                         ;;
  46                 drop)
  47                         iptables -A IPSECBLOCK -d "${subnet}" -j DROP
  48                         ;;
  49                 *)
  50                         return 1
  51                         ;;
  52         esac
  53
  54         return 0
  55 }
  56
  57 install_policy() {
  58         # Flush existing rules
  59         iptables -F IPSECINPUT
  60         iptables -F IPSECOUTPUT
  61         iptables -F IPSECBLOCK
  62
  63         # We are done when IPsec is not enabled
  64         [ "${ENABLED}" = "on" ] || exit 0
  65
  66         # IKE
  67         iptables -A IPSECINPUT  -p udp --dport 500 -j ACCEPT
  68         iptables -A IPSECOUTPUT -p udp --dport 500 -j ACCEPT
  69
  70         # IKE NAT
  71         iptables -A IPSECINPUT  -p udp --dport 4500 -j ACCEPT
  72         iptables -A IPSECOUTPUT -p udp --dport 4500 -j ACCEPT
  73
  74         # Register local variables
  75         local "${VARS[@]}"
  76         local action
  77
  78         while IFS="," read -r "${VARS[@]}"; do
  79                 # Check if the connection is enabled
  80                 [ "${status}" = "on" ] || continue
  81
  82                 # Check if this a net-to-net connection
  83                 [ "${type}" = "net" ] || continue
  84
  85                 # Default local to 0.0.0.0/0
  86                 if [ "${local}" = "" -o "${local}" = "off" ]; then
  87                         local="0.0.0.0/0"
  88                 fi
  89
  90                 # Install permissions for GRE traffic
  91                 case "${interface_mode}" in
  92                         gre)
  93                                 if [ -n "${remote}" ]; then
  94                                         iptables -A IPSECINPUT -p gre \
  95                                                 -s "${remote}" -d "${local}" -j ACCEPT
  96
  97                                         iptables -A IPSECOUTPUT -p gre \
  98                                                 -s "${local}" -d "${remote}" -j ACCEPT
  99                                 fi
 100                                 ;;
 101                 esac
 102
 103                 # Install firewall rules only for interfaces without interface
 104                 [ -n "${interface_mode}" ] && continue
 105
 106                 # Split multiple subnets
 107                 rightsubnets="${rightsubnets//\|/ }"
 108
 109                 case "${route}" in
 110                         route)
 111                                 action="drop"
 112                                 ;;
 113                         *)
 114                                 action="reject"
 115                                 ;;
 116                 esac
 117
 118                 local rightsubnet
 119                 for rightsubnet in ${rightsubnets}; do
 120                         block_subnet "${rightsubnet}" "${action}"
 121                 done
 122         done < "${VPN_CONFIG}"
 123 }
 124
 125 install_policy || exit $?