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|
#!/usr/bin/env bash
# Copyright (C) 2014 Multi-Tech Systems
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
set -e
do_start() {
lan_interfaces=$(echo "$lan" | sed "s/,/ /g")
echo "Configuring firewall rules..."
# Flush all the tables first
iptables -t filter -F
iptables -t nat -F
iptables -t mangle -F
# Drop all incoming packets by default
iptables -t filter -P INPUT DROP
# Accept all on local loopback
iptables -t filter -A INPUT -i lo -j ACCEPT
# Allow packets in for existing socket connections
iptables -t filter -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
# Accept all from LAN interfaces
for i in $lan_interfaces; do
iptables -t filter -A INPUT -i $i -j ACCEPT
# Accept ssh from the LAN (Wired)
#iptables -t filter -A INPUT -i $i -p tcp --dport 22 -j ACCEPT
# Accept http from the LAN (Wired)
#iptables -t filter -A INPUT -i $i -p tcp --dport 80 -j ACCEPT
# Accept tftp from the LAN (Wired)
#iptables -t filter -A INPUT -i $i -p udp --dport 69 -j ACCEPT
done
# Accept ssh from the WAN (Wireless)
#iptables -t filter -A INPUT -i $wan -p tcp --dport 22 -j ACCEPT
# Accept http from the WAN (Wireless)
#iptables -t filter -A INPUT -i $wan -p tcp --dport 80 -j ACCEPT
# Allow packet fowarding from LAN interfaces to WAN (cell router)
iptables -t filter -P FORWARD DROP
iptables -t filter -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
for i in $lan_interfaces; do
iptables -t filter -A FORWARD -i $i -o $wan -j ACCEPT
done
# Allow all output packets
iptables -t filter -P OUTPUT ACCEPT
# enable NAT for cell router
iptables -t nat -A POSTROUTING -o $wan -j MASQUERADE
echo "Enabling packet forwarding..."
# turn on packet forwarding last
echo 1 > /proc/sys/net/ipv4/ip_forward
echo "Done"
}
do_stop() {
echo "Clearing firewall rules..."
# clear all tables
iptables -t filter -F
iptables -t nat -F
iptables -t mangle -F
# reset policies to ACCEPT
iptables -t filter -P INPUT ACCEPT
iptables -t filter -P OUTPUT ACCEPT
iptables -t filter -P FORWARD ACCEPT
# turn off packet forwarding
echo "Disabling packet forwarding..."
echo 0 > /proc/sys/net/ipv4/ip_forward
echo "Done"
}
usage() {
echo "Usage: $(basename $0) start|stop [options]"
echo " options:"
echo " -l <lan-interfaces> LAN interfaces to allow, comma-separated (defaults to \"eth0\")"
echo " -w <wan-interface> WAN interface to route out (defaults to \"ppp0\")"
exit 1
}
# main
if [[ $# < 1 ]]; then
usage
fi
cmd=$1
shift
while getopts "l:w:h" opt; do
case "$opt" in
l)
l=$OPTARG
;;
w)
w=$OPTARG
;;
h)
usage
;;
*)
usage
;;
esac
done
# default lan to eth0 if not specified
lan=${l-eth0}
# default wan to ppp0 if not specified
wan=${w-ppp0}
case $cmd in
start)
echo "LAN: $lan"
echo "WAN: $wan"
do_start
;;
stop)
do_stop
;;
*)
usage
;;
esac
exit 0
|
