freedombone/src/freedombone-utils-firewall

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#!/bin/bash
#
# .---. . .
# | | |
# |--- .--. .-. .-. .-.| .-. .--.--. |.-. .-. .--. .-.
# | | (.-' (.-' ( | ( )| | | | )( )| | (.-'
# ' ' --' --' -' - -' ' ' -' -' -' ' - --'
#
# Freedom in the Cloud
#
# Firewall functions
#
# TODO: in future investigate using nftables
#
# License
# =======
#
# Copyright (C) 2014-2016 Bob Mottram <bob@freedombone.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
FIREWALL_CONFIG=$HOME/${PROJECT_NAME}-firewall.cfg
function save_firewall_settings {
iptables-save > /etc/firewall.conf
ip6tables-save > /etc/firewall6.conf
printf '#!/bin/sh\n' > /etc/network/if-up.d/iptables
printf 'iptables-restore < /etc/firewall.conf\n' >> /etc/network/if-up.d/iptables
printf 'ip6tables-restore < /etc/firewall6.conf\n' >> /etc/network/if-up.d/iptables
if [ -f /etc/network/if-up.d/iptables ]; then
chmod +x /etc/network/if-up.d/iptables
fi
}
function global_rate_limit {
if ! grep -q "tcp_challenge_ack_limit" /etc/sysctl.conf; then
echo 'net.ipv4.tcp_challenge_ack_limit = 999999999' >> /etc/sysctl.conf
else
sed -i 's|net.ipv4.tcp_challenge_ack_limit.*|net.ipv4.tcp_challenge_ack_limit = 999999999|g' /etc/sysctl.conf
fi
sysctl -p -q
}
function enable_ipv6 {
# endure that ipv6 is enabled and can route
sed -i 's/net.ipv6.conf.all.disable_ipv6.*/net.ipv6.conf.all.disable_ipv6 = 0/g' /etc/sysctl.conf
#sed -i "s/net.ipv6.conf.all.accept_redirects.*/net.ipv6.conf.all.accept_redirects = 1/g" /etc/sysctl.conf
#sed -i "s/net.ipv6.conf.all.accept_source_route.*/net.ipv6.conf.all.accept_source_route = 1/g" /etc/sysctl.conf
sed -i "s/net.ipv6.conf.all.forwarding.*/net.ipv6.conf.all.forwarding=1/g" /etc/sysctl.conf
echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
}
function configure_firewall {
if [ $INSTALLING_MESH ]; then
mesh_firewall
return
fi
if grep -q "RELATED" /etc/firewall.conf; then
# recreate the firewall to remove RELATED
sed -i "/firewall/d" $COMPLETION_FILE
fi
if [[ $(is_completed $FUNCNAME) == "1" ]]; then
return
fi
if [[ $INSTALLED_WITHIN_DOCKER == "yes" ]]; then
# docker does its own firewalling
return
fi
iptables -P INPUT ACCEPT
ip6tables -P INPUT ACCEPT
iptables -F
ip6tables -F
iptables -t nat -F
ip6tables -t nat -F
iptables -X
ip6tables -X
iptables -P INPUT DROP
ip6tables -P INPUT DROP
iptables -P FORWARD DROP
ip6tables -P FORWARD DROP
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -m conntrack --ctstate ESTABLISHED -j ACCEPT
# Make sure incoming tcp connections are SYN packets
iptables -A INPUT -p tcp ! --syn -m state --state NEW -j DROP
# Drop packets with incoming fragments
iptables -A INPUT -f -j DROP
# Drop bogons
iptables -A INPUT -p tcp --tcp-flags ALL ALL -j DROP
iptables -A INPUT -p tcp --tcp-flags ALL FIN,PSH,URG -j DROP
iptables -A INPUT -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP
# Incoming malformed NULL packets:
iptables -A INPUT -p tcp --tcp-flags ALL NONE -j DROP
mark_completed $FUNCNAME
}
function configure_firewall_ping {
if [[ $(is_completed $FUNCNAME) == "1" ]]; then
return
fi
# Only allow ping for mesh installs
if [[ $SYSTEM_TYPE != "mesh"* ]]; then
return
fi
iptables -A INPUT -p icmp --icmp-type echo-request -j ACCEPT
iptables -A OUTPUT -p icmp --icmp-type echo-reply -j ACCEPT
function_check save_firewall_settings
save_firewall_settings
mark_completed $FUNCNAME
}
function configure_internet_protocol {
if [[ $(is_completed $FUNCNAME) == "1" ]]; then
return
fi
if [[ $SYSTEM_TYPE == "mesh"* ]]; then
return
fi
sed -i "s/#net.ipv4.tcp_syncookies.*/net.ipv4.tcp_syncookies=1/g" /etc/sysctl.conf
sed -i "s/#net.ipv4.conf.all.accept_redirects.*/net.ipv4.conf.all.accept_redirects = 0/g" /etc/sysctl.conf
sed -i "s/#net.ipv6.conf.all.accept_redirects.*/net.ipv6.conf.all.accept_redirects = 0/g" /etc/sysctl.conf
sed -i "s/#net.ipv4.conf.all.send_redirects.*/net.ipv4.conf.all.send_redirects = 0/g" /etc/sysctl.conf
sed -i "s/#net.ipv4.conf.all.accept_source_route.*/net.ipv4.conf.all.accept_source_route = 0/g" /etc/sysctl.conf
sed -i "s/#net.ipv6.conf.all.accept_source_route.*/net.ipv6.conf.all.accept_source_route = 0/g" /etc/sysctl.conf
sed -i "s/#net.ipv4.conf.default.rp_filter.*/net.ipv4.conf.default.rp_filter=1/g" /etc/sysctl.conf
sed -i "s/#net.ipv4.conf.all.rp_filter.*/net.ipv4.conf.all.rp_filter=1/g" /etc/sysctl.conf
sed -i "s/#net.ipv4.ip_forward.*/net.ipv4.ip_forward=0/g" /etc/sysctl.conf
sed -i "s/#net.ipv6.conf.all.forwarding.*/net.ipv6.conf.all.forwarding=0/g" /etc/sysctl.conf
sed -i "s/# net.ipv4.tcp_syncookies.*/net.ipv4.tcp_syncookies=1/g" /etc/sysctl.conf
sed -i "s/# net.ipv4.conf.all.accept_redirects.*/net.ipv4.conf.all.accept_redirects = 0/g" /etc/sysctl.conf
sed -i "s/# net.ipv6.conf.all.accept_redirects.*/net.ipv6.conf.all.accept_redirects = 0/g" /etc/sysctl.conf
sed -i "s/# net.ipv4.conf.all.send_redirects.*/net.ipv4.conf.all.send_redirects = 0/g" /etc/sysctl.conf
sed -i "s/# net.ipv4.conf.all.accept_source_route.*/net.ipv4.conf.all.accept_source_route = 0/g" /etc/sysctl.conf
sed -i "s/# net.ipv6.conf.all.accept_source_route.*/net.ipv6.conf.all.accept_source_route = 0/g" /etc/sysctl.conf
sed -i "s/# net.ipv4.conf.default.rp_filter.*/net.ipv4.conf.default.rp_filter=1/g" /etc/sysctl.conf
sed -i "s/# net.ipv4.conf.all.rp_filter.*/net.ipv4.conf.all.rp_filter=1/g" /etc/sysctl.conf
sed -i "s/# net.ipv4.ip_forward.*/net.ipv4.ip_forward=0/g" /etc/sysctl.conf
sed -i "s/# net.ipv6.conf.all.forwarding.*/net.ipv6.conf.all.forwarding=0/g" /etc/sysctl.conf
if ! grep -q "ignore pings" /etc/sysctl.conf; then
echo '# ignore pings' >> /etc/sysctl.conf
echo 'net.ipv4.icmp_echo_ignore_all = 1' >> /etc/sysctl.conf
echo 'net.ipv6.icmp_echo_ignore_all = 1' >> /etc/sysctl.conf
fi
if ! grep -q "disable ipv6" /etc/sysctl.conf; then
echo '# disable ipv6' >> /etc/sysctl.conf
echo 'net.ipv6.conf.all.disable_ipv6 = 1' >> /etc/sysctl.conf
fi
if ! grep -q "net.ipv4.tcp_synack_retries" /etc/sysctl.conf; then
echo 'net.ipv4.tcp_synack_retries = 2' >> /etc/sysctl.conf
echo 'net.ipv4.tcp_syn_retries = 1' >> /etc/sysctl.conf
fi
if ! grep -q "keepalive" /etc/sysctl.conf; then
echo '# keepalive' >> /etc/sysctl.conf
echo 'net.ipv4.tcp_keepalive_probes = 9' >> /etc/sysctl.conf
echo 'net.ipv4.tcp_keepalive_intvl = 75' >> /etc/sysctl.conf
echo 'net.ipv4.tcp_keepalive_time = 7200' >> /etc/sysctl.conf
fi
if ! grep -q "net.ipv4.conf.default.send_redirects" /etc/sysctl.conf; then
echo "net.ipv4.conf.default.send_redirects = 0" >> /etc/sysctl.conf
else
sed -i "s|# net.ipv4.conf.default.send_redirects.*|net.ipv4.conf.default.send_redirects = 0|g" /etc/sysctl.conf
sed -i "s|#net.ipv4.conf.default.send_redirects.*|net.ipv4.conf.default.send_redirects = 0|g" /etc/sysctl.conf
sed -i "s|net.ipv4.conf.default.send_redirects.*|net.ipv4.conf.default.send_redirects = 0|g" /etc/sysctl.conf
fi
if ! grep -q "net.ipv4.conf.all.secure_redirects" /etc/sysctl.conf; then
echo "net.ipv4.conf.all.secure_redirects = 0" >> /etc/sysctl.conf
else
sed -i "s|# net.ipv4.conf.all.secure_redirects.*|net.ipv4.conf.all.secure_redirects = 0|g" /etc/sysctl.conf
sed -i "s|#net.ipv4.conf.all.secure_redirects.*|net.ipv4.conf.all.secure_redirects = 0|g" /etc/sysctl.conf
sed -i "s|net.ipv4.conf.all.secure_redirects.*|net.ipv4.conf.all.secure_redirects = 0|g" /etc/sysctl.conf
fi
if ! grep -q "net.ipv4.conf.default.accept_source_route" /etc/sysctl.conf; then
echo "net.ipv4.conf.default.accept_source_route = 0" >> /etc/sysctl.conf
else
sed -i "s|# net.ipv4.conf.default.accept_source_route.*|net.ipv4.conf.default.accept_source_route = 0|g" /etc/sysctl.conf
sed -i "s|#net.ipv4.conf.default.accept_source_route.*|net.ipv4.conf.default.accept_source_route = 0|g" /etc/sysctl.conf
sed -i "s|net.ipv4.conf.default.accept_source_route.*|net.ipv4.conf.default.accept_source_route = 0|g" /etc/sysctl.conf
fi
if ! grep -q "net.ipv4.conf.default.secure_redirects" /etc/sysctl.conf; then
echo "net.ipv4.conf.default.secure_redirects = 0" >> /etc/sysctl.conf
else
sed -i "s|# net.ipv4.conf.default.secure_redirects.*|net.ipv4.conf.default.secure_redirects = 0|g" /etc/sysctl.conf
sed -i "s|#net.ipv4.conf.default.secure_redirects.*|net.ipv4.conf.default.secure_redirects = 0|g" /etc/sysctl.conf
sed -i "s|net.ipv4.conf.default.secure_redirects.*|net.ipv4.conf.default.secure_redirects = 0|g" /etc/sysctl.conf
fi
if ! grep -q "net.ipv4.conf.default.accept_redirects" /etc/sysctl.conf; then
echo "net.ipv4.conf.default.accept_redirects = 0" >> /etc/sysctl.conf
else
sed -i "s|# net.ipv4.conf.default.accept_redirects.*|net.ipv4.conf.default.accept_redirects = 0|g" /etc/sysctl.conf
sed -i "s|#net.ipv4.conf.default.accept_redirects.*|net.ipv4.conf.default.accept_redirects = 0|g" /etc/sysctl.conf
sed -i "s|net.ipv4.conf.default.accept_redirects.*|net.ipv4.conf.default.accept_redirects = 0|g" /etc/sysctl.conf
fi
mark_completed $FUNCNAME
}
function mesh_firewall {
FIREWALL_FILENAME=${rootdir}/etc/systemd/system/meshfirewall.service
MESH_FIREWALL_SCRIPT=${rootdir}/usr/bin/mesh-firewall
echo '#!/bin/bash' > $MESH_FIREWALL_SCRIPT
echo 'iptables -P INPUT ACCEPT' >> $MESH_FIREWALL_SCRIPT
echo 'ip6tables -P INPUT ACCEPT' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -F' >> $MESH_FIREWALL_SCRIPT
echo 'ip6tables -F' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -t nat -F' >> $MESH_FIREWALL_SCRIPT
echo 'ip6tables -t nat -F' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -X' >> $MESH_FIREWALL_SCRIPT
echo 'ip6tables -X' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -P INPUT DROP' >> $MESH_FIREWALL_SCRIPT
echo 'ip6tables -P INPUT DROP' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -A INPUT -i lo -j ACCEPT' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT' >> $MESH_FIREWALL_SCRIPT
echo '' >> $MESH_FIREWALL_SCRIPT
echo '# Make sure incoming tcp connections are SYN packets' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -A INPUT -p tcp ! --syn -m state --state NEW -j DROP' >> $MESH_FIREWALL_SCRIPT
echo '' >> $MESH_FIREWALL_SCRIPT
echo '# Drop packets with incoming fragments' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -A INPUT -f -j DROP' >> $MESH_FIREWALL_SCRIPT
echo '' >> $MESH_FIREWALL_SCRIPT
echo '# Drop bogons' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -A INPUT -p tcp --tcp-flags ALL ALL -j DROP' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -A INPUT -p tcp --tcp-flags ALL FIN,PSH,URG -j DROP' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -A INPUT -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP' >> $MESH_FIREWALL_SCRIPT
echo '' >> $MESH_FIREWALL_SCRIPT
echo '# Incoming malformed NULL packets:' >> $MESH_FIREWALL_SCRIPT
echo 'iptables -A INPUT -p tcp --tcp-flags ALL NONE -j DROP' >> $MESH_FIREWALL_SCRIPT
echo '' >> $MESH_FIREWALL_SCRIPT
echo "iptables -A INPUT -p tcp --dport $TOX_PORT -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
echo "iptables -A INPUT -i $WIFI_INTERFACE -p udp --dport $ZERONET_PORT -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
echo "iptables -A INPUT -i $WIFI_INTERFACE -p tcp --dport $ZERONET_PORT -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
echo "iptables -A INPUT -i $WIFI_INTERFACE -p udp --dport $TRACKER_PORT -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
echo "iptables -A INPUT -i $WIFI_INTERFACE -p tcp --dport $TRACKER_PORT -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
echo "iptables -A INPUT -i $WIFI_INTERFACE -p udp --dport 1900 -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
chmod +x $MESH_FIREWALL_SCRIPT
echo '[Unit]' > $FIREWALL_FILENAME
echo 'Description=Mesh Firewall' >> $FIREWALL_FILENAME
echo '' >> $FIREWALL_FILENAME
echo '[Service]' >> $FIREWALL_FILENAME
echo 'Type=oneshot' >> $FIREWALL_FILENAME
echo 'ExecStart=/usr/bin/mesh-firewall' >> $FIREWALL_FILENAME
echo 'RemainAfterExit=no' >> $FIREWALL_FILENAME
echo '' >> $FIREWALL_FILENAME
echo 'TimeoutSec=30' >> $FIREWALL_FILENAME
echo '' >> $FIREWALL_FILENAME
echo '[Install]' >> $FIREWALL_FILENAME
echo 'WantedBy=multi-user.target' >> $FIREWALL_FILENAME
chmod +x $FIREWALL_FILENAME
chroot "$rootdir" systemctl enable meshfirewall
}
function firewall_add {
firewall_name=$(echo "$1" | sed "s| |-|g")
firewall_port=$2
firewall_protocol="$3"
if ! grep -q "${firewall_name}=${firewall_port}" $FIREWALL_CONFIG; then
echo "${firewall_name}=${firewall_port}" >> $FIREWALL_CONFIG
if [ ! ${firewall_protocol} ]; then
iptables -A INPUT -p udp --dport ${firewall_port} -j ACCEPT
iptables -A INPUT -p tcp --dport ${firewall_port} -j ACCEPT
else
if [[ "${firewall_protocol}" == *"udp"* ]]; then
iptables -A INPUT -p udp --dport ${firewall_port} -j ACCEPT
fi
if [[ "${firewall_protocol}" == *"tcp"* ]]; then
iptables -A INPUT -p tcp --dport ${firewall_port} -j ACCEPT
fi
fi
save_firewall_settings
fi
}
function firewall_add_range {
firewall_name=$(echo "$1" | sed "s| |-|g")
firewall_port_start=$2
firewall_port_end=$3
firewall_protocol="$4"
if ! grep -q "${firewall_name}=${firewall_port_start}:${firewall_port_end}" $FIREWALL_CONFIG; then
echo "${firewall_name}=${firewall_port_start}:${firewall_port_end}" >> $FIREWALL_CONFIG
if [ ! ${firewall_protocol} ]; then
iptables -A INPUT -p udp --dport ${firewall_port_start}:${firewall_port_end} -j ACCEPT
iptables -A INPUT -p tcp --dport ${firewall_port_start}:${firewall_port_end} -j ACCEPT
else
if [[ "${firewall_protocol}" == *"udp"* ]]; then
iptables -A INPUT -p udp --dport ${firewall_port_start}:${firewall_port_end} -j ACCEPT
fi
if [[ "${firewall_protocol}" == *"tcp"* ]]; then
iptables -A INPUT -p tcp --dport ${firewall_port_start}:${firewall_port_end} -j ACCEPT
fi
fi
save_firewall_settings
fi
}
function firewall_remove {
firewall_port=$1
firewall_protocol="$2"
if [ ! -f $FIREWALL_CONFIG ]; then
return
fi
if grep -q "=${firewall_port}" $FIREWALL_CONFIG; then
if [ ! ${firewall_protocol} ]; then
iptables -D INPUT -p udp --dport ${firewall_port} -j ACCEPT
iptables -D INPUT -p tcp --dport ${firewall_port} -j ACCEPT
else
if [[ "${firewall_protocol}" == *"udp"* ]]; then
iptables -D INPUT -p udp --dport ${firewall_port} -j ACCEPT
fi
if [[ "${firewall_protocol}" == *"tcp"* ]]; then
iptables -D INPUT -p tcp --dport ${firewall_port} -j ACCEPT
fi
fi
sed -i "/=${firewall_port}/d" $FIREWALL_CONFIG
save_firewall_settings
fi
}
# NOTE: deliberately no exit 0