Shared Shorewall and Shorewall6 Configuration Tom Eastep 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.
Introduction 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. What is shown here currently works best with Debian and derivatives, or when the tarball installer is used and the SPARSE option is enabled when running configure[.pl].
Environment 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.
Configuration Here are the contents of /etc/shorewall/ and /etc/shorewal6/: root@gateway:/etc# ls -l shorewall shorewall6 shorewall: total 88 -rw-r--r-- 1 root root 201 Mar 19 08:43 action.Mirrors -rw-r--r-- 1 root root 109 Jun 29 15:13 actions -rw-r--r-- 1 root root 655 Jun 29 15:13 conntrack -rw-r--r-- 1 root root 107 Jul 1 10:40 hosts -rw-r--r-- 1 root root 867 Jul 1 10:50 interfaces -rw-r--r-- 1 root root 107 Jun 29 15:14 isusable -rw-r--r-- 1 root root 497 Jul 1 10:42 mangle -rw-r--r-- 1 root root 7 Jul 6 09:24 masq -rw-r--r-- 1 root root 1290 Jun 29 15:16 mirrors -rw-r--r-- 1 root root 2650 Jul 2 08:05 params -rw-r--r-- 1 root root 645 Jun 28 10:04 policy -rw-r--r-- 1 root root 1828 Jul 1 15:43 providers -rw-r--r-- 1 root root 398 Mar 18 20:18 proxyarp -rw-r--r-- 1 root root 702 Jul 1 10:42 rtrules -rw-r--r-- 1 root root 6214 Jul 2 08:45 rules lrwxrwxrwx 1 root root 29 Jul 6 12:42 shorewall6.conf -> ../shorewall6/shorewall6.conf -rw-r--r-- 1 root root 5571 Jun 25 18:09 shorewall.conf -rw-r--r-- 1 root root 1084 Jul 1 10:42 snat -rw-r--r-- 1 root root 181 Jun 29 15:12 started -rw-r--r-- 1 root root 437 Jun 28 10:45 tunnels -rw-r--r-- 1 root root 928 Jun 29 08:25 zones shorewall6: total 12 -rw------- 1 root root 954 Jul 6 12:48 conntrack lrwxrwxrwx 1 root root 20 Jul 6 16:35 mirrors -> ../shorewall/mirrors lrwxrwxrwx 1 root root 19 Jul 6 12:48 params -> ../shorewall/params -rw-r--r-- 1 root root 5328 Jul 6 12:45 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.
shorewall.conf and shorewall6.conf 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="${CONFDIR}/shorewall:/usr/share/shorewall6:${SHAREDIR}/shorewall" /etc/shorewall6/ is only used for processing the params and shorewall6.conf files. /etc/shorewall6/conntrack is installed when SPARSE=Yes, but is not used. The /etc/shorewall/shorewall6.conf symbolic link is required once the above CONFIG_PATH setting is in effect.
shorewall.conf 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
shorewall6.conf 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="${CONFDIR}/shorewall:/usr/share/shorewall6:${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
params 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= 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
zones 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 }
interfaces /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 }
hosts /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 }
policy 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 }
providers 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 }
rtrules 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::/60 PROVIDER=IPv6Fast, PRIORITY=11000 } ?endif
actions /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 $MIRRORS
conntrack In addition to invoking the FTP helper on TCP port 21, this file notracks some IPv4 traffic: #ACTION SOURCE DEST PROTO DPORT SPORT USER SWITCH CT:helper:ftp:P { PROTO=tcp, DPORT=21 } CT:helper:ftp:O { PROTO=tcp, DPORT=21 } ?if __IPV4 # # Don't track IPv4 broadcasts # NOTRACK:P { SOURCE=LOC_IF, DEST=172.20.1.255, PROTO=udp } NOTRACK:P { DEST=255.255.255.255, PROTO=udp } NOTRACK:O { DEST=255.255.255.255, PROTO=udp } NOTRACK:O { DEST=172.20.1.255, PROTO=udp } NOTRACK:O { DEST=70.90.191.127, PROTO=udp } ?endif
rules /etc/shorewall/rules has only a couple of rules that are conditional based on address family: #ACTION SOURCE DEST PROTO DPORT SPORT ORIGDEST RATE USER MARK CONNLIMIT TIME HEADERS SWITCH HELPER ?SECTION ALL Ping(ACCEPT) { SOURCE=net, DEST=all, RATE=d:ping:2/sec:10 } Trcrt(ACCEPT) { SOURCE=net, DEST=all, RATE=d:ping:2/sec:10 } ?SECTION ESTABLISHED ?SECTION RELATED ACCEPT { SOURCE=all, DEST=dmz:$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 }
mangle 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
snat 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::/60, DEST=PROD_IF } SNAT(&FAST_IF) { SOURCE=2001:470:b:227::/64,2001:470:a:227::2, DEST=FAST_IF } ?endif
tunnels 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 }
proxyarp 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 }
isuable This is just the standard Shorewall isusable extension script: local status status=0 [ -f ${VARDIR}/${1}.status ] && status=$(cat ${VARDIR}/${1}.status) return $status
started /etc/shorewall/started only does something in the IPv4 configuration, although it gets compiled into both scripts: if [ $g_family = 4 ]; then qt $IP -4 route replace 70.90.191.122 dev br0 qt $IP -4 route replace 70.90.191.124 dev br0 qt $IP -4 route replace 70.90.191.125 dev br0 fi