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="${2}"
  36
  37         # Nothing to be done if no action is requested
  38         if [ "${action}" = "none" ]; then
  39                 return 0
  40         fi
  41
  42         # Don't block a wildcard subnet
  43         if [ "${subnet}" = "0.0.0.0/0" ] || [ "${subnet}" = "0.0.0.0/0.0.0.0" ]; then
  44                 return 0
  45         fi
  46
  47         case "${action}" in
  48                 reject)
  49                         iptables -A IPSECBLOCK -d "${subnet}" -j REJECT --reject-with icmp-net-unreachable
  50                         ;;
  51                 drop)
  52                         iptables -A IPSECBLOCK -d "${subnet}" -j DROP
  53                         ;;
  54                 *)
  55                         return 1
  56                         ;;
  57         esac
  58
  59         return 0
  60 }
  61
  62 install_policy() {
  63         # Flush existing rules
  64         iptables -F IPSECINPUT
  65         iptables -F IPSECOUTPUT
  66         iptables -F IPSECBLOCK
  67
  68         # We are done when IPsec is not enabled
  69         [ "${ENABLED}" = "on" ] || exit 0
  70
  71         # IKE
  72         iptables -A IPSECINPUT  -p udp --dport 500 -j ACCEPT
  73         iptables -A IPSECOUTPUT -p udp --dport 500 -j ACCEPT
  74
  75         # IKE NAT
  76         iptables -A IPSECINPUT  -p udp --dport 4500 -j ACCEPT
  77         iptables -A IPSECOUTPUT -p udp --dport 4500 -j ACCEPT
  78
  79         # Register local variables
  80         local "${VARS[@]}"
  81         local action
  82
  83         while IFS="," read -r "${VARS[@]}"; do
  84                 # Check if the connection is enabled
  85                 [ "${status}" = "on" ] || continue
  86
  87                 # Check if this a net-to-net connection
  88                 [ "${type}" = "net" ] || continue
  89
  90                 # Default local to 0.0.0.0/0
  91                 if [ "${local}" = "" -o "${local}" = "off" ]; then
  92                         local="0.0.0.0/0"
  93                 fi
  94
  95                 # Install permissions for GRE traffic
  96                 case "${interface_mode}" in
  97                         gre)
  98                                 if [ -n "${remote}" ]; then
  99                                         iptables -A IPSECINPUT -p gre \
 100                                                 -s "${remote}" -d "${local}" -j ACCEPT
 101
 102                                         iptables -A IPSECOUTPUT -p gre \
 103                                                 -s "${local}" -d "${remote}" -j ACCEPT
 104                                 fi
 105                                 ;;
 106                 esac
 107
 108                 # Install firewall rules only for interfaces without interface
 109                 [ -n "${interface_mode}" ] && continue
 110
 111                 # Split multiple subnets
 112                 rightsubnets="${rightsubnets//\|/ }"
 113
 114                 case "${route}" in
 115                         route)
 116                                 action="none"
 117                                 ;;
 118                         *)
 119                                 action="reject"
 120                                 ;;
 121                 esac
 122
 123                 local rightsubnet
 124                 for rightsubnet in ${rightsubnets}; do
 125                         block_subnet "${rightsubnet}" "${action}"
 126                 done
 127         done < "${VPN_CONFIG}"
 128 }
 129
 130 install_policy || exit $?