Copyright © 2017 Thomas M. Eastep
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover, and with no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License”.
2017/07/27
Table of Contents
Netfilter separates management of IPv4 and IPv6 configurations. Each address family has its own utility (iptables and ip6tables), and changes made to the configuration of one address family do not affect the other. While Shorewall also separates the address families in this way, it is possible for Shorewall and Shorewall6 to share almost all of the configuration files. This article gives an example.
In this example, each address family has two Internet interfaces. Both address families share a fast uplink (eth0) that has a single public IPv4 address, but can delegate IPv6 subnets to the Shorewall-based router. Both address families also have a production uplink. For IPv4, Ethernet is used (eth1) and supports the public IPv4 subnet 70.90.191.120/29. For IPv6, a Hurricane Electric 6in4 tunnel is used (sit1), which provides the public IPv6 subnet 2001:470:b:227::/64. The router also has two bridges. A DMZ bridge (br0) provides access to containers running a web server, a mail exchanger, and an IMAPS mail access server. The second bridge (br1) provides access to a container running irssi under screen, allowing constant access to and monitoring of IRC channels.
Here are the contents of /etc/shorewall/ and /etc/shorewal6/:
root@gateway:/etc# ls shorewall shorewall6 shorewall: action.Mirrors conntrack interfaces mangle params providers rtrules shorewall.conf started zones actions hosts isusable mirrors policy proxyarp rules snat tunnels shorewall6: shorewall6.conf root@gateway:/etc#
The various configuration files are described in the sections that follow. Note that in all cases, these files use the alternate format for column specification.
These are the only files that are not shared between the two address families. The key setting is CONFIG_PATH in shorewall6.conf:
CONFIG_PATH="${CONFDIR}/shorewall6:${CONFDIR}/shorewall:/usr/share/shorewall6:${SHAREDIR}/shorewall"AAny Shorewall6 configuration file not found in /etc/shorewall/shorewall6/ will be searched for in /etc/shorewall/.
The contents of /etc/shorewall/shorewall.conf are as follows:
###############################################################################
# S T A R T U P E N A B L E D
###############################################################################
STARTUP_ENABLED=Yes
###############################################################################
# V E R B O S I T Y
###############################################################################
VERBOSITY=1
###############################################################################
# P A G E R
###############################################################################
PAGER=pager
###############################################################################
# F I R E W A L L
###############################################################################
FIREWALL=
###############################################################################
# L O G G I N G
###############################################################################
LOG_LEVEL="NFLOG(0,64,1)"
BLACKLIST_LOG_LEVEL="none"
INVALID_LOG_LEVEL=
LOG_BACKEND=netlink
LOG_MARTIANS=Yes
LOG_VERBOSITY=1
LOGALLNEW=
LOGFILE=/var/log/ulogd/ulogd.syslogemu.log
LOGFORMAT=": %s %s"
LOGTAGONLY=Yes
LOGLIMIT="s:5/min"
MACLIST_LOG_LEVEL="$LOG_LEVEL"
RELATED_LOG_LEVEL="$LOG_LEVEL:,related"
RPFILTER_LOG_LEVEL="$LOG_LEVEL:,rpfilter"
SFILTER_LOG_LEVEL="$LOG_LEVEL"
SMURF_LOG_LEVEL="$LOG_LEVEL"
STARTUP_LOG=/var/log/shorewall-init.log
TCP_FLAGS_LOG_LEVEL="$LOG_LEVEL"
UNTRACKED_LOG_LEVEL=
###############################################################################
# L O C A T I O N O F F I L E S A N D D I R E C T O R I E S
###############################################################################
ARPTABLES=
CONFIG_PATH="/etc/shorewall:/usr/share/shorewall:/usr/share/shorewall/Shorewall"
GEOIPDIR=/usr/share/xt_geoip/LE
IPTABLES=/sbin/iptables
IP=/sbin/ip
IPSET=
LOCKFILE=/var/lib/shorewall/lock
MODULESDIR="+extra/RTPENGINE"
NFACCT=
PATH="/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin"
PERL=/usr/bin/perl
RESTOREFILE=
SHOREWALL_SHELL=/bin/sh
SUBSYSLOCK=
TC=
###############################################################################
# D E F A U L T A C T I O N S / M A C R O S
###############################################################################
ACCEPT_DEFAULT="none"
BLACKLIST_DEFAULT="NotSyn(DROP):$LOG_LEVEL"
DROP_DEFAULT="Broadcast(DROP),Multicast(DROP)"
NFQUEUE_DEFAULT="none"
QUEUE_DEFAULT="none"
REJECT_DEFAULT="Broadcast(DROP),Multicast(DROP)"
###############################################################################
# R S H / R C P C O M M A N D S
###############################################################################
RCP_COMMAND='scp ${files} ${root}@${system}:${destination}'
RSH_COMMAND='ssh ${root}@${system} ${command}'
###############################################################################
# F I R E W A L L O P T I O N S
###############################################################################
ACCOUNTING=Yes
ACCOUNTING_TABLE=mangle
ADD_IP_ALIASES=No
ADD_SNAT_ALIASES=No
ADMINISABSENTMINDED=Yes
AUTOCOMMENT=Yes
AUTOHELPERS=No
AUTOMAKE=Yes
BALANCE_PROVIDERS=No
BASIC_FILTERS=No
BLACKLIST="NEW,INVALID,UNTRACKED"
CLAMPMSS=Yes
CLEAR_TC=Yes
COMPLETE=No
DEFER_DNS_RESOLUTION=No
DELETE_THEN_ADD=No
DETECT_DNAT_IPADDRS=No
DISABLE_IPV6=No
DOCKER=No
DONT_LOAD="nf_nat_sip,nf_conntrack_sip,nf_conntrack_h323,nf_nat_h323"
DYNAMIC_BLACKLIST="ipset-only,disconnect,timeout=7200"
EXPAND_POLICIES=Yes
EXPORTMODULES=Yes
FASTACCEPT=Yes
FORWARD_CLEAR_MARK=Yes
HELPERS="ftp,irc"
IGNOREUNKNOWNVARIABLES=No
IMPLICIT_CONTINUE=No
INLINE_MATCHES=Yes
IPSET_WARNINGS=Yes
IP_FORWARDING=Yes
KEEP_RT_TABLES=Yes
LOAD_HELPERS_ONLY=Yes
MACLIST_TABLE=filter
MACLIST_TTL=60
MANGLE_ENABLED=Yes
MAPOLDACTIONS=No
MARK_IN_FORWARD_CHAIN=No
MINIUPNPD=Yes
MODULE_SUFFIX="ko ko.xz"
MULTICAST=No
MUTEX_TIMEOUT=60
NULL_ROUTE_RFC1918=unreachable
OPTIMIZE=All
OPTIMIZE_ACCOUNTING=No
PERL_HASH_SEED=12345
REJECT_ACTION=
REQUIRE_INTERFACE=No
RESTART=restart
RESTORE_DEFAULT_ROUTE=No
RESTORE_ROUTEMARKS=Yes
RETAIN_ALIASES=No
ROUTE_FILTER=No
SAVE_ARPTABLES=No
SAVE_IPSETS=ipv4
TC_ENABLED=No
TC_EXPERT=No
TC_PRIOMAP="2 3 3 3 2 3 1 1 2 2 2 2 2 2 2 2"
TRACK_PROVIDERS=Yes
TRACK_RULES=No
USE_DEFAULT_RT=Yes
USE_NFLOG_SIZE=No
USE_PHYSICAL_NAMES=Yes
USE_RT_NAMES=Yes
VERBOSE_MESSAGES=No
WARNOLDCAPVERSION=Yes
WORKAROUNDS=No
ZERO_MARKS=Yes
ZONE2ZONE=-
###############################################################################
# P A C K E T D I S P O S I T I O N
###############################################################################
BLACKLIST_DISPOSITION=DROP
INVALID_DISPOSITION=CONTINUE
MACLIST_DISPOSITION=ACCEPT
RELATED_DISPOSITION=REJECT
RPFILTER_DISPOSITION=DROP
SMURF_DISPOSITION=DROP
SFILTER_DISPOSITION=DROP
TCP_FLAGS_DISPOSITION=DROP
UNTRACKED_DISPOSITION=DROP
################################################################################
# P A C K E T M A R K L A Y O U T
################################################################################
TC_BITS=8
PROVIDER_BITS=2
PROVIDER_OFFSET=16
MASK_BITS=8
ZONE_BITS=0
The contents of /etc/shorewall6/shorewall6.conf are:
###############################################################################
# S T A R T U P E N A B L E D
###############################################################################
STARTUP_ENABLED=Yes
###############################################################################
# V E R B O S I T Y
###############################################################################
VERBOSITY=1
###############################################################################
# P A G E R
###############################################################################
PAGER=pager
###############################################################################
# F I R E W A L L
###############################################################################
FIREWALL=
###############################################################################
# L O G G I N G
###############################################################################
LOG_LEVEL="NFLOG(0,64,1)"
BLACKLIST_LOG_LEVEL="none"
INVALID_LOG_LEVEL=
LOG_BACKEND=netlink
LOG_VERBOSITY=2
LOGALLNEW=
LOGFILE=/var/log/ulogd/ulogd.syslogemu.log
LOGFORMAT="%s %s "
LOGLIMIT="s:5/min"
LOGTAGONLY=Yes
MACLIST_LOG_LEVEL="$LOG_LEVEL"
RELATED_LOG_LEVEL=
RPFILTER_LOG_LEVEL="$LOG_LEVEL"
SFILTER_LOG_LEVEL="$LOG_LEVEL"
SMURF_LOG_LEVEL="$LOG_LEVEL"
STARTUP_LOG=/var/log/shorewall6-init.log
TCP_FLAGS_LOG_LEVEL="$LOG_LEVEL"
UNTRACKED_LOG_LEVEL=
###############################################################################
# L O C A T I O N O F F I L E S A N D D I R E C T O R I E S
###############################################################################
CONFIG_PATH="${CONFDIR}/shorewall6:${CONFDIR}/shorewall:/usr/share/shorewall6:${SHAREDIR}/shorewall"
GEOIPDIR=/usr/share/xt_geoip/LE
IP6TABLES=
IP=
IPSET=
LOCKFILE=
MODULESDIR="+extra/RTPENGINE"
NFACCT=
PERL=/usr/bin/perl
PATH="/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin:/usr/local/sbin"
RESTOREFILE=restore
SHOREWALL_SHELL=/bin/sh
SUBSYSLOCK=/var/lock/subsys/shorewall6
TC=
###############################################################################
# D E F A U L T A C T I O N S / M A C R O S
###############################################################################
ACCEPT_DEFAULT="none"
BLACKLIST_DEFAULT="AllowICMPs,Broadcast(DROP),Multicast(DROP),dropNotSyn:$LOG_LEVEL,dropInvalid:$LOG_LEVEL,DropDNSrep:$LOG_LEVEL"
DROP_DEFAULT="AllowICMPs,Broadcast(DROP),Multicast(DROP)"
NFQUEUE_DEFAULT="none"
QUEUE_DEFAULT="none"
REJECT_DEFAULT="AllowICMPs,Broadcast(DROP),Multicast(DROP)"
###############################################################################
# R S H / R C P C O M M A N D S
###############################################################################
RCP_COMMAND='scp ${files} ${root}@${system}:${destination}'
RSH_COMMAND='ssh ${root}@${system} ${command}'
###############################################################################
# F I R E W A L L O P T I O N S
###############################################################################
ACCOUNTING=Yes
ACCOUNTING_TABLE=mangle
ADMINISABSENTMINDED=Yes
AUTOCOMMENT=Yes
AUTOHELPERS=Yes
AUTOMAKE=Yes
BALANCE_PROVIDERS=No
BASIC_FILTERS=No
BLACKLIST="NEW,INVALID,UNTRACKED"
CLAMPMSS=Yes
CLEAR_TC=No
COMPLETE=No
DEFER_DNS_RESOLUTION=Yes
DELETE_THEN_ADD=No
DONT_LOAD=
DYNAMIC_BLACKLIST="ipset-only,disconnect,timeout=7200"
EXPAND_POLICIES=Yes
EXPORTMODULES=Yes
FASTACCEPT=Yes
FORWARD_CLEAR_MARK=Yes
HELPERS=
IGNOREUNKNOWNVARIABLES=No
IMPLICIT_CONTINUE=No
INLINE_MATCHES=No
IPSET_WARNINGS=Yes
IP_FORWARDING=Keep
KEEP_RT_TABLES=Yes
LOAD_HELPERS_ONLY=Yes
MACLIST_TABLE=filter
MACLIST_TTL=
MANGLE_ENABLED=Yes
MARK_IN_FORWARD_CHAIN=No
MINIUPNPD=Yes
MODULE_SUFFIX=ko
MUTEX_TIMEOUT=60
OPTIMIZE=All
OPTIMIZE_ACCOUNTING=No
PERL_HASH_SEED=0
REJECT_ACTION=
REQUIRE_INTERFACE=No
RESTART=restart
RESTORE_DEFAULT_ROUTE=Yes
RESTORE_ROUTEMARKS=Yes
SAVE_IPSETS=No
TC_ENABLED=Shared
TC_EXPERT=No
TC_PRIOMAP="2 3 3 3 2 3 1 1 2 2 2 2 2 2 2 2"
TRACK_PROVIDERS=Yes
TRACK_RULES=No
USE_DEFAULT_RT=Yes
USE_NFLOG_SIZE=No
USE_PHYSICAL_NAMES=No
USE_RT_NAMES=No
VERBOSE_MESSAGES=Yes
WARNOLDCAPVERSION=Yes
WORKAROUNDS=No
ZERO_MARKS=No
ZONE2ZONE=-
###############################################################################
# P A C K E T D I S P O S I T I O N
###############################################################################
BLACKLIST_DISPOSITION=DROP
INVALID_DISPOSITION=CONTINUE
MACLIST_DISPOSITION=REJECT
RELATED_DISPOSITION=REJECT
SFILTER_DISPOSITION=DROP
RPFILTER_DISPOSITION=DROP
SMURF_DISPOSITION=DROP
TCP_FLAGS_DISPOSITION=DROP
UNTRACKED_DISPOSITION=DROP
################################################################################
# P A C K E T M A R K L A Y O U T
################################################################################
TC_BITS=8
PROVIDER_BITS=2
PROVIDER_OFFSET=8
MASK_BITS=8
ZONE_BITS=0
Because addresses and interfaces are different between the two address families, they cannot be hard-coded in the configuration files. /etc/shorewall/params is used to set shell variables whose contents will vary between Shorewall and Shorewall6. In the params file and in run-time extension files, the shell variable g_family can be used to determine which address family to use; if IPv4, then $g_family will expand to 4 and if IPv6, $g_family will expand to 6.
The contents of /etc/shorewall/params is as follows:
INCLUDE mirrors #Sets the MIRRORS variable for the Mirrors action
#
# Set compile-time variables depending on the address family
#
if [ $g_family = 4 ]; then
#
# IPv4 compilation
#
FALLBACK=Yes # Make FAST_IF the primary and PROD_IF the fallback interface
# See /etc/shorewall/providers
STATISTICAL=No # Don't use statistical load balancing
LISTS=70.90.191.124 # IP address of lists.shorewall.net (MX)
MAIL=70.90.191.122 # IP address of mail.shorewall.net (IMAPS)
SERVER=70.90.191.125 # IP address of www.shorewall.org
PROXY=Yes # Use TPROXY for local web access
ALL=0.0.0.0/0 # Entire address space
LOC_ADDR=172.20.1.253 # IP address of the local LAN interface
FAST_GATEWAY=10.2.10.1 # Default gateway through the IF_FAST interface
FAST_MARK=0x20000 # Multi-ISP mark setting for IF_FAST
#
# Interface Options
#
LOC_OPTIONS=dhcp,ignore=1,wait=5,routefilter,routeback,tcpflags=0,nodbl,physical=eth2
FAST_OPTIONS=optional,dhcp,tcpflags,logmartians,nosmurfs,sourceroute=0,arp_ignore=1,proxyarp=0,upnp,nosmurfs,physical=eth0
PROD_OPTIONS=optional,dhcp,tcpflags,logmartians,nosmurfs,sourceroute=0,arp_ignore=1,proxyarp=0,upnp,nosmurfs,physical=eth1
DMZ_OPTIONS=routeback,proxyarp=1,required,wait=30,nets=70.90.191.120/29,dhcp,nodbl,physical=br0
IRC_OPTIONS=routeback,proxyarp=1,required,wait=30,nets=172.20.2.0/24,dhcp,nodbl,physical=br1
else
#
# IPv6 compilation
#
FALLBACK=Yes # Make FAST_IF the primary and PROD_IF the fallback interface
# See /etc/shorewall/providers
STATISTICAL=No # Don't use statistical load balancing
LISTS=[2001:470:b:227::42] # IP address of lists.shorewall.net (MX and HTTPS)
MAIL=[2001:470:b:227::45] # IP address of mail.shorewall.net (IMAPS and HTTPS)
SERVER=[2001:470:b:227::43] # IP address of www.shorewall.org (HTTP, FTP and RSYNC)
PROXY=Yes # Use TPROXY for local web access
ALL=[::]/0 # Entire address space
LOC_ADDR=[2601:601:8b00:bf0::1] # IP address of the local LAN interface
FAST_GATEWAY=fe80::22e5:2aff:feb7:f2cf # Default gateway through the IF_FAST interface
FAST_MARK=0x100 # Multi-ISP mark setting for IF_FAST
#
# Interface Options
#
PROD_OPTIONS=forward=1,optional,physical=sit1
FAST_OPTIONS=forward=1,optional,dhcp,upnp,physical=eth0
LOC_OPTIONS=forward=1,nodbl,routeback,physical=eth2
DMZ_OPTIONS=routeback,forward=1,required,wait=30,nodbl,physical=br0
IRC_OPTIONS=routeback,forward=1,required,wait=30,nodbl,physical=br1
fi
Here is the /etc/shorewall/zones file:
#ZONE TYPE OPTIONS IN OUT
# OPTIONS OPTIONS
#
# By using the 'ip' type, both Shorewall and Shorewall6 can share this file
#
fw { TYPE=firewall }
net { TYPE=ip }
loc { TYPE=ip }
dmz { TYPE=ip }
apps { TYPE=ip }
vpn1 { TYPE=ipsec, OPTIONS=mode=tunnel,proto=esp }
/etc/shorewall/interfaces makes heavy use of variables set in /etc/shorewall/params:
#
# LOC_IF is the local LAN for both families
# FAST_IF is a Comcast IPv6 beta uplink which is used for internet access from the local lan for both families
# PROD_IF is the interface used by shorewall.org servers
# For IPv4, it is eth1
# For IPv6, it is sit1 (Hurricane Electric 6in4 link)
# DMZ_IF is a bridge to the production containers
# IRC_IF is a bridge to a container that currently runs irssi under screen
loc { INTERFACE=LOC_IF, OPTIONS=$LOC_OPTIONS }
net { INTERFACE=FAST_IF, OPTIONS=$FAST_OPTIONS }
net { INTERFACE=PROD_IF, OPTIONS=$PROD_OPTIONS }
dmz { INTERFACE=DMZ_IF, OPTIONS=$DMZ_OPTIONS }
apps { INTERFACE=IRC_IF, OPTIONS=$IRC_OPTIONS }/etc/shorewall/hosts is used to define the vpn zone:
#ZONE HOSTS OPTIONS
vpn1 { HOSTS=PROD_IF:$ALL }
vpn1 { HOSTS=FAST_IF:$ALL }
vpn1 { HOSTS=LOC_IF:$ALL }
The same set of policies apply to both address families:
#SOURCE DEST POLICY LOGLEVEL RATE
$FW { DEST=dmz,net, POLICY=REJECT, LOGLEVEL=$LOG_LEVEL }
$FW { DEST=all, POLICY=ACCEPT }
loc { DEST=net, POLICY=ACCEPT }
loc,vpn1,apps { DEST=loc,vpn1,apps POLICY=ACCEPT }
loc { DEST=fw, POLICY=REJECT, LOGLEVEL=$LOG_LEVEL }
net { DEST=net, POLICY=NONE }
net { DEST=fw, POLICY=BLACKLIST:+Broadcast(DROP),Multicast(DROP),DropDNSrep:$LOG_LEVEL, LOGLEVEL=$LOG_LEVEL, RATE=8/sec:30 }
net { DEST=all, POLICY=BLACKLIST:+DropDNSrep:$LOG_LEVEL, LOGLEVEL=$LOG_LEVEL, RATE=8/sec:30 }
dmz { DEST=fw, POLICY=REJECT, LOGLEVEL=$LOG_LEVEL }
all { DEST=all, POLICY=REJECT, LOGLEVEL=$LOG_LEVEL }
The providers file is set up to allow for three different configurations:
FALLBACK -- FAST_IF is the primary interface and PROD_IF is the fallback
STATISTICAL -- Statistical load balancing between FAST_IF and PROD_IF
IPv4 only -- balance between FAST_IF and PROD_IF
#
# This could be cleaned up a bit, but I'm leaving it as is for now
#
# - The two address families use different fw mark geometry
# - The two address families use different fallback interfaces
# - The 'balance' option doesn't work as expected in IPv6 so I have no balance configuration for Shorewall6
# - IPv4 uses the 'loose' option on PROD_IF
#
?if $FALLBACK
# FAST_IF is primary, PROD_IF is fallback
#
?info Compiling with FALLBACK
IPv6Fast { NUMBER=1, MARK=$FAST_MARK, INTERFACE=FAST_IF, GATEWAY=$FAST_GATEWAY, OPTIONS=loose,primary,persistent }
?if __IPV4
ComcastB { NUMBER=4, MARK=0x10000, INTERFACE=PROD_IF, GATEWAY=10.1.10.1, OPTIONS=loose,fallback,persistent }
?else
HE { NUMBER=2, MARK=0x200, INTERFACE=PROD_IF, OPTIONS=fallback,persistent }
?endif
?elsif $STATISTICAL
# Statistically balance traffic between FAST_IF and PROD_IF
?info Compiling with STATISTICAL
?if __IPV4
IPv6Fast { NUMBER=1, MARK=0x20000, INTERFACE=FAST_IF, GATEWAY=$FAST_GATEWAY, OPTIONS=loose,load=0.66666667,primary }
?else
HE { NUMBER=2, MARK=0x200, INTERFACE=PROD_IF, OPTIONS=track,load=0.33333333,persistent }
?endif
?else
?INFO Compiling with BALANCE
IPv6Fast { NUMBER=1, MARK=0x100, INTERFACE=eth0, GATEWAY=$FAST_GATEWAY, OPTIONS=track,balance=2,loose,persistent }
?if __IPV4
ComcastB { NUMBER=4, MARK=0x10000, INTERFACE=IPV4_IF, GATEWAY=10.1.10.1, OPTIONS=nohostroute,loose,balance,persistent }
?else
?warning No BALANCE IPv6 configuration - using FALLBACK
HE { NUMBER=2, MARK=0x200, INTERFACE=PROD_IF, OPTIONS=fallback,persistent }
?endif
?endif
Tproxy { NUMBER=3, INTERFACE=lo, OPTIONS=tproxy }
The routing rules are quite dependent on the address family:
#SOURCE DEST PROVIDER PRIORITY
#
# This file ensures that the DMZ is routed out of the IF_PROD interface
# and that the IPv6 subnets delegated by the Fast router are routed out
# of the IF_FAST interface.
#
?if __IPV4
{ SOURCE=70.90.191.121,70.90.191.123, PROVIDER=ComcastB, PRIORITY=1000! }
{ SOURCE=&FAST_IF, PROVIDER=IPv6Fast, PRIORITY=1000! }
{ SOURCE=br0, PROVIDER=ComcastB, PRIORITY=11000 }
?else
{ SOURCE=2001:470:A:227::/64, PROVIDER=HE, PRIORITY=1000! }
{ SOURCE=2001:470:B:227::/64, PROVIDER=HE, PRIORITY=11000 }
{ SOURCE=2601:601:8b00:bf0::/56 PROVIDER=IPv6Fast, PRIORITY=11000 }
?endif
/etc/shorewall/actions defines one action:
#ACTION COMMENT Mirrors # Accept traffic from Shorewall Mirrors
/etc/shorewall/action.Mirrors:
#TARGET SOURCE DEST PROTO DEST SOURCE ORIGINAL RATE # PORT PORT(S) DEST LIMIT ?COMMENT Accept traffic from Mirrors ?FORMAT 2 DEFAULTS - $1 $MIRRORS
In addition to invoking the FTP helper on TCP port 21, this file notracks some IPv4 traffic:
#ACTION SOURCE DEST PROTO DPORT SPORT USER SWITCH
CT:helper:ftp:P { PROTO=tcp, DPORT=21 }
CT:helper:ftp:O { PROTO=tcp, DPORT=21 }
?if __IPV4
#
# Don't track IPv4 broadcasts
#
NOTRACK:P { SOURCE=LOC_IF, DEST=172.20.1.255, PROTO=udp }
NOTRACK:P { DEST=255.255.255.255, PROTO=udp }
NOTRACK:O { DEST=255.255.255.255, PROTO=udp }
NOTRACK:O { DEST=172.20.1.255, PROTO=udp }
NOTRACK:O { DEST=70.90.191.127, PROTO=udp }
?endif
/etc/shorewall/rules has only a couple of rules that are conditional based on address family:
#ACTION SOURCE DEST PROTO DPORT SPORT ORIGDEST RATE USER MARK CONNLIMIT TIME HEADERS SWITCH HELPER
?SECTION ALL
Ping(ACCEPT) { SOURCE=net, DEST=all, RATE=d:ping:2/sec:10 }
Trcrt(ACCEPT) { SOURCE=net, DEST=all, RATE=d:ping:2/sec:10 }
?SECTION ESTABLISHED
?SECTION RELATED
ACCEPT { SOURCE=all, DEST=dmz:$SERVER, PROTO=tcp, DPORT=61001:62000, helper=ftp }
ACCEPT { SOURCE=dmz, DEST=all, PROTO=tcp, helper=ftp }
ACCEPT { SOURCE=all, DEST=net, PROTO=tcp, helper=ftp }
ACCEPT { SOURCE=all, DEST=all, PROTO=icmp }
RST(ACCEPT) { SOURCE=all, DEST=all }
ACCEPT { SOURCE=dmz, DEST=dmz }
?SECTION INVALID
RST(ACCEPT) { SOURCE=all, DEST=all }
DROP { SOURCE=net, DEST=all }
FIN { SOURCE=all, DEST=all }
?SECTION UNTRACKED
?if __IPV4
Broadcast(ACCEPT) { SOURCE=all, DEST=$FW }
ACCEPT { SOURCE=all, DEST=$FW, PROTO=udp }
CONTINUE { SOURCE=loc, DEST=$FW }
CONTINUE { SOURCE=$FW, DEST=all }
?endif
?SECTION NEW
######################################################################################################
# Stop certain outgoing traffic to the net
#
REJECT:$LOG_LEVEL { SOURCE=loc,vpn1,apps DEST=net, PROTO=tcp, DPORT=25 } #Stop direct loc->net SMTP (Comcast uses submission).
REJECT:$LOG_LEVEL { SOURCE=loc,vpn1,apps DEST=net, PROTO=udp, DPORT=1025:1031 } #MS Messaging
REJECT { SOURCE=all, DEST=net, PROTO=tcp, DPORT=137,445, comment="Stop NETBIOS Crap" }
REJECT { SOURCE=all, DEST=net, PROTO=udp, DPORT=137:139, comment="Stop NETBIOS Crap" }
REJECT { SOURCE=all, DEST=net, PROTO=tcp, DPORT=3333, comment="Disallow port 3333" }
REJECT { SOURCE=all, DEST=net, PROTO=udp, DPORT=3544, comment="Stop Teredo" }
?COMMENT
######################################################################################################
# 6in4
#
?if __IPV4
ACCEPT { SOURCE=net:216.218.226.238, DEST=$FW, PROTO=41 }
ACCEPT { SOURCE=$FW, DEST=net:216.218.226.238, PROTO=41 }
?endif
######################################################################################################
# Ping
#
Ping(ACCEPT) { SOURCE=$FW,loc,dmz,vpn1, DEST=$FW,loc,dmz,vpn1 }
Ping(ACCEPT) { SOURCE=all, DEST=net }
######################################################################################################
# SSH
#
AutoBL(SSH,60,-,-,-,-,$LOG_LEVEL)\
{ SOURCE=net, DEST=all, PROTO=tcp, DPORT=22 }
SSH(ACCEPT) { SOURCE=all, DEST=all }
?if __IPV4
SSH(DNAT-) { SOURCE=net, DEST=172.20.2.44, PROTO=tcp, DPORT=ssh, ORIGDEST=70.90.191.123 }
?endif
######################################################################################################
# DNS
#
DNS(ACCEPT) { SOURCE=loc,dmz,vpn1,apps, DEST=$FW }
DNS(ACCEPT) { SOURCE=$FW, DEST=net }
######################################################################################################
# Traceroute
#
Trcrt(ACCEPT) { SOURCE=all, DEST=net }
Trcrt(ACCEPT) { SOURCE=net, DEST=$FW,dmz }
######################################################################################################
# Email
#
SMTP(ACCEPT) { SOURCE=net,$FW, DEST=dmz:$LISTS }
SMTP(ACCEPT) { SOURCE=dmz:$LISTS, DEST=net:PROD_IF }
SMTP(REJECT) { SOURCE=dmz:$LISTS, DEST=net }
IMAPS(ACCEPT) { SOURCE=all, DEST=dmz:$MAIL }
Submission(ACCEPT) { SOURCE=all, DEST=dmz:$LISTS }
SMTPS(ACCEPT) { SOURCE=all, DEST=dmz:$LISTS }
IMAP(ACCEPT) { SOURCE=loc,vpn1, DEST=net }
######################################################################################################
# NTP
#
NTP(ACCEPT) { SOURCE=all, DEST=net }
NTP(ACCEPT) { SOURCE=loc,vpn1,dmz,apps DEST=$FW }
######################################################################################################
# HTTP/HTTPS
#
Web(ACCEPT) { SOURCE=loc,vpn1 DEST=$FW }
Web(ACCEPT) { SOURCE=$FW, DEST=net, USER=proxy }
Web(DROP) { SOURCE=net, DEST=fw, PROTO=tcp, comment="Do not blacklist web crawlers" }
HTTP(ACCEPT) { SOURCE=net,loc,vpn1,apps,$FW DEST=dmz:$SERVER,$LISTS }
HTTPS(ACCEPT) { SOURCE=net,loc,vpn1,apps,$FW DEST=dmz:$LISTS,$MAIL }
Web(ACCEPT) { SOURCE=dmz,apps DEST=net,$FW }
Web(ACCEPT) { SOURCE=$FW, DEST=net, USER=root }
Web(ACCEPT) { SOURCE=$FW, DEST=net, USER=teastep }
######################################################################################################
# FTP
#
FTP(ACCEPT) { SOURCE=loc,vpn1,apps DEST=net }
FTP(ACCEPT) { SOURCE=dmz, DEST=net }
FTP(ACCEPT) { SOURCE=$FW, DEST=net, USER=root }
FTP(ACCEPT) { SOURCE=all, DEST=dmz:$SERVER }
#
# Some FTP clients seem prone to sending the PORT command split over two packets.
# This prevents the FTP connection tracking code from processing the command and setting
# up the proper expectation.
#
# The following rule allows active FTP to work in these cases
# but logs the connection so I can keep an eye on this potential security hole.
#
ACCEPT:$LOG_LEVEL { SOURCE=dmz, DEST=net, PROTO=tcp, DPORT=1024:, SPORT=20 }
######################################################################################################
# whois
#
Whois(ACCEPT) { SOURCE=all, DEST=net }
######################################################################################################
# SMB
#
SMBBI(ACCEPT) { SOURCE=loc, DEST=$FW }
SMBBI(ACCEPT) { SOURCE=vpn1, DEST=$FW }
######################################################################################################
# IRC
#
IRC(ACCEPT) { SOURCE=loc,vpn1,apps:IRC_IF, DEST=net }
######################################################################################################
# Rsync
#
Mirrors(ACCEPT:none) { SOURCE=net, DEST=dmz:$SERVER, PROTO=tcp, DPORT=873 }
Note that TPROXY can be enabled/disabled via a shell variable setting in /etc/shorewall/params:
#ACTION SOURCE DEST PROTO DPORT SPORT USER TEST LENGTH TOS CONNBYTES HELPER PROBABILITY DSCP
?if __IPV4
#
# I've had a checksum issue with certain IPv4 UDP packets
#
CHECKSUM:T { DEST=FAST_IF, PROTO=udp }
CHECKSUM:T { DEST=DMZ_IF, PROTO=udp }
?endif
?if $PROXY
#
# Use TPROXY for web access from the local LAN
#
DIVERT:R { PROTO=tcp, SPORT=80 }
DIVERT:R { PROTO=tcp, DPORT=80 }
TPROXY(3129,$LOC_ADDR) { SOURCE=LOC_IF, PROTO=tcp, DPORT=80 }
?endif
NAT entries are quite dependent on the address family:
#ACTION SOURCE DEST PROTO PORT IPSEC MARK USER SWITCH ORIGDEST PROBABILITY
?if __IPV4
MASQUERADE { SOURCE=172.20.1.0/24,172.20.2.0/24, DEST=FAST_IF }
MASQUERADE { SOURCE=70.90.191.120/29, DEST=FAST_IF }
SNAT(70.90.191.121) { SOURCE=!70.90.191.120/29, DEST=PROD_IF, PROBABILITY=0.50, COMMENT="Masquerade Local Network" }
SNAT(70.90.191.123) { SOURCE=!70.90.191.120/29, DEST=PROD_IF, COMMENT="Masquerade Local Network" }
SNAT(172.20.1.253) { SOURCE=172.20.3.0/24, DEST=LOC_IF:172.20.1.100 }
?else
SNAT(&PROD_IF) { SOURCE=2601:601:8b00:bf0::56, DEST=PROD_IF }
SNAT(&FAST_IF) { SOURCE=2001:470:b:227::/64,2001:470:a:227::2, DEST=FAST_IF }
?endif
Both address families define IPSEC tunnels:
#TYPE ZONE GATEWAY GATEWAY_ZONE
ipsecnat {ZONE=net, GATEWAY=$ALL, GATEWAY_ZONE=vpn1 }
ipsecnat {ZONE=loc, GATEWAY=$ALL, GATEWAY_ZONE=vpn1 }
This file is only used in the IPv4 configuration:
#ADDRESS INTERFACE EXTERNAL HAVEROUTE PERSISTENT
70.90.191.122 { INTERFACE=br0, EXTERNAL=eth1, HAVEROUTE=yes, PERSISTENT=no }
This is just the standard Shorewall isusable extension script:
local status
status=0
[ -f ${VARDIR}/${1}.status ] && status=$(cat ${VARDIR}/${1}.status)
return $status