eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
eval $(/usr/local/bin/readhash /var/ipfire/optionsfw/settings)
IFACE=`/bin/cat /var/ipfire/red/iface 2> /dev/null | /usr/bin/tr -d '\012'`
+if [ -z $IFACE]; then
+ IFACE="red0"
+fi
if [ -f /var/ipfire/red/device ]; then
DEVICE=`/bin/cat /var/ipfire/red/device 2> /dev/null | /usr/bin/tr -d '\012'`
fi
+NAT_MASK="0x0f000000"
+
+IPS_REPEAT_MARK="0x80000000"
+IPS_REPEAT_MASK="0x80000000"
+IPS_BYPASS_MARK="0x40000000"
+IPS_BYPASS_MASK="0x40000000"
+
function iptables() {
/sbin/iptables --wait "$@"
}
modprobe nf_log_ipv4
sysctl -q -w net.netfilter.nf_log.2=nf_log_ipv4
+ # IPS Bypass Chain which stores the BYPASS bit in connection tracking
+ iptables -N IPSBYPASS
+ iptables -A IPSBYPASS -j CONNMARK --save-mark --mask "$(( ~IPS_REPEAT_MASK & 0xffffffff ))"
+
+ # Jump into bypass chain when the BYPASS bit is set
+ for chain in INPUT FORWARD OUTPUT; do
+ iptables -A "${chain}" -m mark \
+ --mark "$(( IPS_REPEAT_MARK | IPS_BYPASS_MARK ))/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j IPSBYPASS
+ done
+
# Empty LOG_DROP and LOG_REJECT chains
iptables -N LOG_DROP
iptables -A LOG_DROP -m limit --limit 10/second -j LOG
fi
iptables -A NEWNOTSYN -j DROP -m comment --comment "DROP_NEWNOTSYN"
+ # Log and subsequently drop spoofed packets or "martians", arriving from sources
+ # on interfaces where we don't expect them
+ iptables -N SPOOFED_MARTIAN
+ if [ "$DROPSPOOFEDMARTIAN" == "on" ]; then
+ iptables -A SPOOFED_MARTIAN -m limit --limit 10/second -j LOG --log-prefix "DROP_SPOOFED_MARTIAN "
+ fi
+ iptables -A SPOOFED_MARTIAN -j DROP -m comment --comment "DROP_SPOOFED_MARTIAN"
+
# Chain to contain all the rules relating to bad TCP flags
iptables -N BADTCP
# Connection tracking chains
iptables -N CONNTRACK
iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED -j ACCEPT
- iptables -A CONNTRACK -m conntrack --ctstate INVALID -j DROP
+ iptables -A CONNTRACK -m conntrack --ctstate INVALID -j LOG_DROP
iptables -A CONNTRACK -p icmp -m conntrack --ctstate RELATED -j ACCEPT
- iptables -t raw -N CONNTRACK
- iptables -t raw -A PREROUTING -j CONNTRACK
-
- # Conntrack helpers (https://home.regit.org/netfilter-en/secure-use-of-helpers/)
-
- # GRE (always enabled)
- modprobe nf_conntrack_proto_gre
-
- # SIP
- if [ "${CONNTRACK_SIP}" = "on" ]; then
- modprobe nf_nat_sip
- iptables -A CONNTRACK -m conntrack --ctstate RELATED \
- -m helper --helper sip -j ACCEPT
- for proto in udp tcp; do
- iptables -t raw -A CONNTRACK -p "${proto}" --dport 5060 -j CT --helper sip
- done
- fi
-
- # H.323
- if [ "${CONNTRACK_H323}" = "on" ]; then
- modprobe nf_nat_h323
- iptables -A CONNTRACK -m conntrack --ctstate RELATED \
- -m helper --helper h323 -j ACCEPT
-
- # Gatekeeper RAS
- iptables -t raw -A CONNTRACK -p udp --dport 1719 -j CT --helper RAS
-
- # Q.931
- iptables -t raw -A CONNTRACK -p tcp --dport 1720 -j CT --helper Q.931
- fi
-
- # FTP
- if [ "${CONNTRACK_FTP}" = "on" ]; then
- modprobe nf_nat_ftp
- iptables -A CONNTRACK -m conntrack --ctstate RELATED \
- -m helper --helper ftp -p tcp --dport 1024: -j ACCEPT
- iptables -t raw -A CONNTRACK -p tcp --dport 21 -j CT --helper ftp
- fi
-
- # PPTP
- if [ "${CONNTRACK_PPTP}" = "on" ]; then
- modprobe nf_nat_pptp
- iptables -A CONNTRACK -m conntrack --ctstate RELATED \
- -m helper --helper pptp -j ACCEPT
- iptables -t raw -A CONNTRACK -p tcp --dport 1723 -j CT --helper pptp
- fi
- # TFTP
- if [ "${CONNTRACK_TFTP}" = "on" ]; then
- modprobe nf_nat_tftp
- iptables -A CONNTRACK -m conntrack --ctstate RELATED \
- -m helper --helper tftp -j ACCEPT
- iptables -t raw -A CONNTRACK -p udp --dport 69 -j CT --helper tftp
- fi
-
- # IRC
- if [ "${CONNTRACK_IRC}" = "on" ]; then
- modprobe nf_nat_irc
- iptables -A CONNTRACK -m conntrack --ctstate RELATED \
- -m helper --helper irc -j ACCEPT
- iptables -t raw -A CONNTRACK -p tcp --dport 6667 -j CT --helper irc
- fi
-
- # Amanda
- if [ "${CONNTRACK_AMANDA}" = "on" ]; then
- modprobe nf_nat_amanda
- iptables -A CONNTRACK -m conntrack --ctstate RELATED \
- -m helper --helper amanda -j ACCEPT
- iptables -t raw -A CONNTRACK -p tcp -j CT --helper amanda
- fi
+ # Restore any connection marks
+ iptables -t mangle -A PREROUTING -j CONNMARK --restore-mark
# Fix for braindead ISPs
iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
iptables -t nat -N CUSTOMPOSTROUTING
iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
+ # Log and drop any traffic from and to networks known as being hostile, posing
+ # a technical threat to our users (i. e. listed at Spamhaus DROP et al.)
+ iptables -N HOSTILE
+ if [ "$DROPHOSTILE" == "on" ]; then
+ iptables -A HOSTILE -m limit --limit 10/second -j LOG --log-prefix "DROP_HOSTILE "
+ iptables -A INPUT -i $IFACE -m geoip --src-cc XD -j HOSTILE
+ iptables -A FORWARD -i $IFACE -m geoip --src-cc XD -j HOSTILE
+ iptables -A FORWARD -o $IFACE -m geoip --dst-cc XD -j HOSTILE
+ iptables -A OUTPUT -o $IFACE -m geoip --src-cc XD -j HOSTILE
+ fi
+ iptables -A HOSTILE -j DROP -m comment --comment "DROP_HOSTILE"
+
# P2PBLOCK
iptables -N P2PBLOCK
iptables -A INPUT -j P2PBLOCK
iptables -A FORWARD -j P2PBLOCK
iptables -A OUTPUT -j P2PBLOCK
-
+
# IPS (Guardian) chains
iptables -N GUARDIAN
iptables -A INPUT -j GUARDIAN
iptables -N IPS_INPUT
iptables -N IPS_FORWARD
iptables -N IPS_OUTPUT
- iptables -A INPUT -j IPS_INPUT
- iptables -A FORWARD -j IPS_FORWARD
- iptables -A OUTPUT -j IPS_OUTPUT
+
+ for chain in INPUT FORWARD OUTPUT; do
+ iptables -A "${chain}" -m mark --mark "0x0/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j "IPS_${chain}"
+ done
# OpenVPN transfer network translation
iptables -t nat -N OVPNNAT
iptables -A INPUT -j ICMPINPUT
iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
- # Accept everything on loopback
+ # Accept everything on loopback if source/destination is loopback space...
iptables -N LOOPBACK
- iptables -A LOOPBACK -i lo -j ACCEPT
- iptables -A LOOPBACK -o lo -j ACCEPT
+ iptables -A LOOPBACK -i lo -s 127.0.0.0/8 -j ACCEPT
+ iptables -A LOOPBACK -o lo -d 127.0.0.0/8 -j ACCEPT
+
+ # ... and drop everything else on the loopback interface, since no other traffic should appear there
+ iptables -A LOOPBACK -i lo -j SPOOFED_MARTIAN
+ iptables -A LOOPBACK -o lo -j SPOOFED_MARTIAN
- # Filter all packets with loopback addresses on non-loopback interfaces.
- iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
- iptables -A LOOPBACK -d 127.0.0.0/8 -j DROP
+ # Filter all packets with loopback addresses on non-loopback interfaces (spoofed)
+ iptables -A LOOPBACK -s 127.0.0.0/8 -j SPOOFED_MARTIAN
+ iptables -A LOOPBACK -d 127.0.0.0/8 -j SPOOFED_MARTIAN
for i in INPUT FORWARD OUTPUT; do
iptables -A ${i} -j LOOPBACK
iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
fi
+ # Tor (inbound)
+ iptables -N TOR_INPUT
+ iptables -A INPUT -j TOR_INPUT
+
# Location Block
iptables -N LOCATIONBLOCK
iptables -A INPUT -j LOCATIONBLOCK
iptables -N OVPNINPUT
iptables -A INPUT -j OVPNINPUT
- # Tor (inbound and outbound)
- iptables -N TOR_INPUT
- iptables -A INPUT -j TOR_INPUT
+ # Tor (outbound)
iptables -N TOR_OUTPUT
iptables -A OUTPUT -j TOR_OUTPUT
-
+
# Jump into the actual firewall ruleset.
iptables -N INPUTFW
iptables -A INPUT -j INPUTFW
if [ -n "${GREEN_ADDRESS}" ]; then
iptables -t nat -A NAT_DESTINATION_FIX \
- -m mark --mark 1 -j SNAT --to-source "${GREEN_ADDRESS}"
+ -m mark --mark "0x01000000/${NAT_MASK}" -j SNAT --to-source "${GREEN_ADDRESS}"
fi
if [ -n "${BLUE_ADDRESS}" ]; then
iptables -t nat -A NAT_DESTINATION_FIX \
- -m mark --mark 2 -j SNAT --to-source "${BLUE_ADDRESS}"
+ -m mark --mark "0x02000000/${NAT_MASK}" -j SNAT --to-source "${BLUE_ADDRESS}"
fi
if [ -n "${ORANGE_ADDRESS}" ]; then
iptables -t nat -A NAT_DESTINATION_FIX \
- -m mark --mark 3 -j SNAT --to-source "${ORANGE_ADDRESS}"
+ -m mark --mark "0x04000000/${NAT_MASK}" -j SNAT --to-source "${ORANGE_ADDRESS}"
fi
# RED chain, used for the red interface
iptables -F REDFORWARD
iptables -t nat -F REDNAT
+ # Prohibit spoofing our own IP address on RED
+ if [ -f /var/ipfire/red/active ]; then
+ REDIP="$( cat /var/ipfire/red/local-ipaddress )";
+
+ if [ "$IFACE" != "" ]; then
+ iptables -A REDINPUT -s $REDIP -i $IFACE -j SPOOFED_MARTIAN
+ elif [ "$DEVICE" != "" ]; then
+ iptables -A REDINPUT -s $REDIP -i $DEVICE -j SPOOFED_MARTIAN
+ fi
+ fi
+
# PPPoE / PPTP Device
if [ "$IFACE" != "" ]; then
# PPPoE / PPTP
iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
fi
- # Outgoing masquerading (don't masqerade IPsec (mark 50))
- iptables -t nat -A REDNAT -m mark --mark 50 -o $IFACE -j RETURN
+ # Outgoing masquerading (don't masqerade IPsec)
+ iptables -t nat -A REDNAT -m policy --pol ipsec --dir=out -o "${IFACE}" -j RETURN
if [ "${IFACE}" = "${GREEN_DEV}" ]; then
iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN