option iptables
option clearall
option createchains
option automod

############# Define variables
set IFCONFIG   "/sbin/ifconfig"
set AWK 	     "/usr/bin/awk"
set GREP 	     "/bin/grep" 
set CAT 	     "/bin/cat"
set SED 	     "/bin/sed"

set MASK	     "29"  # Our netmask is /29 = 255.255.255.248
set IPS        "64.20.38.170"
set IFS        "eth0"
set IPSPEC     "64.20.38.170/%MASK"

set NSIP       `%CAT /etc/resolv.conf | %GREP nameserver | %AWK '{print $2}'`
#set NTPIP	   `%CAT /etc/ntp.conf | %GREP server | %AWK '{print $2}'`

############# Port/protocol combinations we allow in and out
set TCP_IN	   "ssh,smtp,auth,www,ssmtp,https,imap,imaps,pop3,pop3s"
set TCP_OUT_DELAY	   "ssh,ftp,auth"
set TCP_OUT_RELIABILITY	   "http,nntp,smtp,pop3,auth,domain"
set TCP_OUT_THROUGHPUT	   "ftp-data"
#set TCP_OUT_COST	   ""

set UDP_IN	   "ntp,domain"
set UDP_OUT	   "1:65535"

set ICMP_IN	   "ping,pong,destination-unreachable,source-quench,time-exceeded,parameter-problem"
set ICMP_OUT	 "ping,pong,fragmentation-needed,source-quench,parameter-problem"


# Make us insensitive to the environment

# Allow traffic in areas outside of our scope
policy DROP {
	table mangle chain forward;
	table filter chain forward;
	table filter chain (INPUT,OUTPUT);
}
policy ACCEPT {
	table mangle chain (PREROUTING,INPUT,OUTPUT,POSTROUTING);
	table nat    chain (PREROUTING,OUTPUT,POSTROUTING);
}

######################################################################
# Built-in chains that jump to our custom ones

chain INPUT {
	state INVALID goto LDROP;
	fragment goto LDROP;
#	goto IANA_BAN;
#	goto LOCAL_BAN;
	#goto PORTSCAN; # Do we need this? There are better, dedicated tools

	state (ESTABLISHED,RELATED) ACCEPT;

	if lo saddr 127.0.0.1/8 daddr 127.0.0.1/8 ACCEPT;
	if lo saddr %IPSPEC     daddr %IPSPEC     ACCEPT;
	if lo goto LDROP;

	#incoming traffic
	goto badguys;
	protocol tcp goto fw_tcp;
	protocol udp goto fw_udp;
	protocol icmp goto fw_icmp;

	goto LDROP;
}

chain OUTPUT {
	state INVALID goto LDENY;
	fragment goto LDENY;

	state (ESTABLISHED,RELATED) ACCEPT;

	of lo saddr 127.0.0.1/8 daddr 127.0.0.1/8 ACCEPT;
	of lo saddr %IPSPEC     daddr %IPSPEC     ACCEPT;
	of lo goto LDENY;

	saddr !%IPSPEC goto LDENY;

	# again uncomment for trojan horses protection and inside out
	# violations....
	proto (tcp,udp) sport 14000: goto LDENY;

	# queueing goes here, maybe some special fw rules as well
	proto tcp goto tosqueue; # ACCEPT must be handled here

	proto udp dport %UDP_OUT ACCEPT;
	proto icmp icmptype %ICMP_OUT ACCEPT;

	goto LDENY;
}

#####################################################################
# Deal with known offenders right away
# Make difference between notorious ones and unusual ones
chain badguys {

	saddr(
		# Mailbombing nion's email
		152.163.210.178
		205.188.135.170
		64.12.187.193

		# Executed nion's CGI script 400,000 times
		24.186.165.67

		# docelic, Wed Aug  3 04:18:56 EDT 2005
		# Trying out new server with all kinds of usernames on ssh
		# (All of those seem to be from the same "mastermind")
		211.48.20.153
		62.36.240.114
		62.75.240.62
		210.204.193.1
		84.26.59.170

		# Log says reverse mapping failed for this address
		# (hundreds of entries)
		114.67.19.241
	) {
		DROP;
	}
}

#####################################################################
# TCP traffic
chain fw_tcp proto tcp {
	# Standard allowances
	syn dport %TCP_IN sport 1024: {
		limit 5/s ACCEPT;
		limit 20/m LOG log-prefix "SYN flood attack:" LOG;
		goto LDROP;
	}

	# Should be covered by (RELATED,ESTABLISHED) ACCEPT above
	#dport %TCP_IN accept;

	# deny scanning via DNS port
	sport domain {
		dport domain ACCEPT;
		syn goto LDROP;
	}

	# special case to allow active ftp transfers to our machine!
	sport ftp-data dport 1024: {
		ACCEPT;
	}

	# awkward incoming connections
	syn {
		goto LDROP;
	}

	# want to deny inside-out fake stuff? uncomment this:
	# (see /proc/sys/net/ipv4/ip_local_port_range ): Tune the file to 13999 !
	dport 14000: { 
		goto LDROP;
	}
}

#####################################################################
# UDP traffic
chain fw_udp proto udp {
	# Standard allowances
	dport %UDP_IN sport 1024: {
		ACCEPT;
	}

	# again no dns fumbling around
	sport domain dport domain saddr %NSIP {
		ACCEPT;
	}
}


#####################################################################
# ICMP traffic
chain fw_icmp proto icmp {
	# Standard allowances
	icmptype %ICMP_IN {
		ACCEPT;
	}

	#icmp-type echo-request limit 1/s ACCEPT;
	#icmptype ( ping pong destination-unreachable time-exceeded) {
	#	ACCEPT;
	#}
	# never seen hits on this one:
}


#####################################################################
# TOS (Type-of-service) adjustments
chain tosqueue {
	protocol tcp {
		# rapid response protocols
#		dport %TCP_OUT_DELAY settos min-delay ACCEPT;
		dport %TCP_OUT_DELAY ACCEPT;
		sport %TCP_OUT_DELAY ACCEPT;
		# keep these from timing out
#		dport %TCP_OUT_RELIABILITY settos max-reliability ACCEPT;
		dport %TCP_OUT_RELIABILITY ACCEPT;
		sport %TCP_OUT_RELIABILITY ACCEPT;
		# bulk stuff
#		dport %TCP_OUT_THROUGHPUT settos max-throughput ACCEPT;
		dport %TCP_OUT_THROUGHPUT ACCEPT;
		sport %TCP_OUT_THROUGHPUT ACCEPT;
#    dport (ftp-data,8888,6699) settos max-throughput ACCEPT;
    dport (ftp-data,8888,6699) ACCEPT;
    sport (ftp-data,8888,6699) ACCEPT;
	}

#	proto tcp dport %TCP_OUT_COST settos min-cost ACCEPT;
	goto LDENY;
}

#####################################################################
# Supporting targets
chain LDROP {
	LOG {
		log-level info logprefix "Dropped";
		log-level warn fragment log-prefix "FRAGMENT Dropped";
	}
	DROP;
}

chain LDENY {
	LOG {
		log-level info proto tcp logprefix "Denied";
		log-level warn fragment log-prefix "FRAGMENT Denied";
	}
	DENY;
}