Name
files — Shorewall Configuration Files
Synopsis
/etc/shorewall[6]/*
Description
The following are the Shorewall[6] configuration files:
/etc/shorewall/shorewall.confand/etc/shorewall6/shorewall6.conf- used to set global firewall parameters./etc/shorewall[6]/params- use this file to set shell variables that you will expand in other files. It is always processed by /bin/sh or by the shell specified through SHOREWALL_SHELL in/etc/shorewall/shorewall.conf./etc/shorewall[6]/zones- partition the firewall's view of the world into zones./etc/shorewall[6]/policy- establishes firewall high-level policy./etc/shorewall[6]/initdone- An optional Perl script that will be invoked by the Shorewall rules compiler when the compiler has finished it's initialization./etc/shorewall[6]/interfaces- describes the interfaces on the firewall system./etc/shorewall[6]/hosts- allows defining zones in terms of individual hosts and subnetworks./etc/shorewall[6]/masq- directs the firewall where to use many-to-one (dynamic) Network Address Translation (a.k.a. Masquerading) and Source Network Address Translation (SNAT). Superseded by /etc/shorewall[6]/snat in Shorewall 5.0.14 and not supported in Shorewall 5.1.0 and later versions./etc/shorewall[6]/mangle- supersedes/etc/shorewall/tcrulesin Shorewall 4.6.0. Contains rules for packet marking, TTL, TPROXY, etc./etc/shorewall[6]/rules- defines rules that are exceptions to the overall policies established in /etc/shorewall/policy./etc/shorewall[6]/nat- defines one-to-one NAT rules./etc/shorewall6/proxyarp- defines use of Proxy ARP./etc/shorewall6/proxyndp- defines use of Proxy NDP./etc/shorewall[6]/routestopped- defines hosts accessible when Shorewall is stopped. Superseded in Shorewall 4.6.8 by/etc/shorewall/stoppedrules. Not supported in Shorewall 5.0.0 and later versions./etc/shorewall[6]/tcrules- The file has a rather unfortunate name because it is used to define marking of packets for later use by both traffic control/shaping and policy routing. This file is superseded by/etc/shorewall/manglein Shorewall 4.6.0. Not supported in Shorewall 5.0.0 and later releases./etc/shorewall[6]/tos- defines rules for setting the TOS field in packet headers. Superseded in Shorewall 4.5.1 by the TOS target in/etc/shorewall/tcrules(which file has since been superseded by/etc/shorewall/mangle). Not supported in Shorewall 5.0.0 and later versions./etc/shorewall[6]/tunnels- defines tunnels (VPN) with end-points on the firewall system./etc/shorewall[6]/blacklist- Deprecated in favor of/etc/shorewall/blrules. Lists blacklisted IP/subnet/MAC addresses. Not supported in Shorewall 5.0.0 and later releases./etc/shorewall[6]/blrules— Added in Shorewall 4.5.0. Define blacklisting and whitelisting. Supersedes/etc/shorewall/blacklist./etc/shorewall[6]/init- shell commands that you wish to execute at the beginning of a “shorewall start”, "shorewall reload" or “shorewall restart”./etc/shorewall[6]/start- shell commands that you wish to execute near the completion of a “shorewall start”, "shorewall reload" or “shorewall restart”/etc/shorewall[6]/started- shell commands that you wish to execute after the completion of a “shorewall start”, "shorewall reload" or “shorewall restart”/etc/shorewall[6]/stop- commands that you wish to execute at the beginning of a “shorewall stop”./etc/shorewall[6]/stopped- shell commands that you wish to execute at the completion of a “shorewall stop”./etc/shorewall/ecn - disable Explicit Congestion Notification (ECN - RFC 3168) to remote hosts or networks. Superseded by ECN entries in
/etc/shorewall/manglein Shorewall 5.0.6./etc/shorewall/accounting- define IP traffic accounting rules/etc/shorewall[6]/actionsand/usr/share/shorewall[6]/action.templateallow user-defined actions./etc/shorewall[6]/providers- defines alternate routing tables./etc/shorewall[6]/rtrules- Defines routing rules to be used in conjunction with the routing tables defined in/etc/shorewall/providers./etc/shorewall[6]/tcdevices,/etc/shorewall[6]/tcclasses,/etc/shorewall[6]/tcfilters- Define complex traffic shaping./etc/shorewall[6]/tcrules- Mark or classify traffic for traffic shaping or multiple providers. Deprecated in Shorewall 4.6.0 in favor of/etc/shorewall/mangle. Not supported in Shorewall 5.0.0 and later releases./etc/shorewall[6]/tcinterfacesand/etc/shorewall[6]/tcpri- Define simple traffic shaping./etc/shorewall[6]/secmarks- Added in Shorewall 4.4.13. Attach an SELinux context to selected packets./etc/shorewall[6]/vardir- Determines the directory where Shorewall maintains its state./etc/shorewall/arprules— Added in Shorewall 4.5.12. Allows specification of arptables rules./etc/shorewall/mangle-- Added in Shorewall 4.6.0. Supersedes/etc/shorewall/tcrules./etc/shorewall[6]/snat- directs the firewall where to use many-to-one (dynamic) Network Address Translation (a.k.a. Masquerading) and Source Network Address Translation (SNAT). Superseded /etc/shorewall[6]/masq in Shorewall 5.0.14/usr/share/shorewall[6]/actions.std- Actions defined by Shorewall./usr/share/shorewall[6]/action.*- Details of actions defined by Shorewall./usr/share/shorewall[6]/macro.*- Details of macros defined by Shorewall./usr/share/shorewall[6]/modules— Specifies the kernel modules to be loaded during shorewall start/restart./usr/share/shorewall[6]/helpers— Added in Shorewall 4.4.7. Specifies the kernel modules to be loaded during shorewall start/restart when LOAD_HELPERS_ONLY=Yes inshorewall.conf.
CONFIG_PATH
The CONFIG_PATH option in shorewall[6].conf(5) determines where the compiler searches for configuration files. The default setting is CONFIG_PATH=/etc/shorewall:/usr/share/shorewall which means that the compiler first looks in /etc/shorewall and if it doesn't find the file, it then looks in /usr/share/shorewall.
You can change this setting to have the compiler look in different places. For example, if you want to put your own versions of standard macros in /etc/shorewall/Macros, then you could set CONFIG_PATH=/etc/shorewall:/etc/shorewall/Macros:/usr/share/shorewall and the compiler will use your versions rather than the standard ones.
Comments
You may place comments in configuration files by making the first non-whitespace character a pound sign (“#”). You may also place comments at the end of any line, again by delimiting the comment from the rest of the line with a pound sign.
Example 1. Comments in a Configuration File
# This is a comment ACCEPT net $FW tcp www #This is an end-of-line comment
Important
Except in shorewall.conf(5) and params(5), if a comment ends with a backslash ("\"), the next line will also be treated as a comment. See Line Continuation below.
Blank Lines
Most of the configuration files are organized into space-separated columns. If you don't want to supply a value in a column but want to supply a value in a following column, simply enter '-' to make the column appear empty.
Example:
#INTERFACE BROADCAST OPTIONS br0 - routeback
Line Continuation
Lines may be continued using the usual backslash (“\”) followed immediately by a new line character (Enter key).
ACCEPT net $FW tcp \↵ smtp,www,pop3,imap #Services running on the firewall
Important
What follows does NOT apply to shorewall-params(5) and shorewall.conf(5).
In certain cases, leading white space is ignored in continuation lines:
The continued line ends with a colon (":")
The continued line ends with a comma (",")
Example (/etc/shorewall/rules):
#ACTION SOURCE DEST PROTO DPORT
ACCEPT net:\
206.124.146.177,\
206.124.146.178,\
206.124.146.180\
dmz tcp 873The leading white space on the first through third continuation lines is ignored so the SOURCE column effectively contains "net:206.124.146.177,206.124.147.178,206.124.146.180". Because the third continuation line does not end with a comma or colon, the leading white space in the last line is not ignored.
Important
A trailing backslash is not ignored in a comment. So the continued rule above can be commented out with a single '#' as follows:
#ACTION SOURCE DEST PROTO DPORT
#ACCEPT net:\
206.124.146.177,\
206.124.146.178,\
206.124.146.180\
dmz tcp 873Alternative Specification of Column Values
Some of the configuration files now have a large number of columns. That makes it awkward to specify a value for one of the right-most columns as you must have the correct number of intervening '-' columns.
This problem is addressed by allowing column values to be specified
as column-name/value
pairs.
There is considerable flexibility in how you specify the pairs:
At any point, you can enter a left curly bracket ('{') followed by one or more specifications of the following forms:
column-name=valuecolumn-name=>valuecolumn-name:valueThe pairs must be followed by a right curly bracket ("}").
The value may optionally be enclosed in double quotes.
The pairs must be separated by white space, but you can add a comma adjacent to the
valuesfor readability as in:{ proto=>udp, port=1024 } You can also separate the pairs from columns by using a semicolon:
; proto:udp, port:1024
In Shorewall 5.0.3, the sample configuration files and the man pages were updated to use the same column names in both the column headings and in the alternate specification format. The following table shows the column names for each of the table-oriented configuration files.
Note
Column names are case-insensitive.
| File | Column names |
| accounting | action,chain, source, dest, proto, dport, sport, user, mark, ipsec, headers |
| conntrack | action,source,dest,proto,dport,sport,user,switch |
| blacklist | networks,proto,port,options |
| blrules | action,source,dest,proto,dport,sport,origdest,rate,user,mark,connlimit,time,headers,switch,helper |
| ecn | interface,hosts. Beginning with Shorewall 4.5.4, 'host' is a synonym for 'hosts'. |
| hosts | zone,hosts,options. Beginning with Shorewall 4.5.4, 'host' is a synonym for 'hosts'. |
| interfaces | zone,interface,broadcast,options |
| maclist | disposition,interface,mac,addresses |
| mangle | action,source,dest,proto,dport,sport,user,test,length,tos,connbytes,helper,headers |
| masq | interface,source,address,proto,port,ipsec,mark,user,switch |
| nat | external,interface,internal,allints,local |
| netmap | type,net1,interface,net2,net3,proto,dport,sport |
| notrack | source,dest,proto,dport,sport,user |
| policy | source,dest,policy,loglevel,limit,connlimit |
| providers | table,number,mark,duplicate,interface,gateway,options,copy |
| proxyarp and proxyndp | address,interface,external,haveroute,persistent |
| rtrules | source,dest,provider,priority |
| routes | provider,dest,gateway,device |
| routestopped | interface,hosts,options,proto,dport,sport |
| rules | action,source,dest,proto,dport,sport,origdest,rate,user,mark,connlimit,time,headers,switch,helper |
| secmarks | secmark,chain,source,dest,proto,dport,sport,user,mark |
| tcclasses | interface,mark,rate,ceil,prio,options |
| tcdevices | interface,in_bandwidth,out_bandwidth,options,redirect |
| tcfilters | class,source,dest,proto,dport,sport,tos,length |
| tcinterfaces | interface,type,in_bandwidth,out_bandwidth |
| tcpri | band,proto,port,address,interface,helper |
| tcrules | mark,source,dest,proto,dport,sport,user,test,length,tos,connbytes,helper,headers. Beginning with Shorewall 4.5.3, 'action' is a synonym for 'mark'. |
| tos | source,dest,proto,dport,sport,tos,mark |
| tunnels | type,zone,gateway,gateway_zone. Beginning with Shorewall 4.5.3, 'gateways' is a synonym for 'gateway'. Beginning with Shorewall 4.5.4, 'gateway_zones' is a synonym for 'gateway_zone'. |
| zones | zone,type,options,in_options,out_options |
Example (rules file):
#ACTION SOURCE DEST PROTO DPORT DNAT net loc:10.0.0.1 tcp 80 ; mark="88"
Here's the same line in several equivalent formats:
{ action=>DNAT, source=>net, dest=>loc:10.0.0.1, proto=>tcp, dport=>80, mark=>88 }
; action:"DNAT" source:"net" dest:"loc:10.0.0.1" proto:"tcp" dport:"80" mark:"88"
DNAT { source=net dest=loc:10.0.0.1 proto=tcp dport=80 mark=88 }Beginning with Shorewall 5.0.11, ip[6]table comments can be attached
to individual rules using the comment keyword.
Example from the rules file:
ACCEPT net $FW { proto=tcp, dport=22, comment="Accept \"SSH\"" }As shown in that example, when the comment contains whitespace, it must be enclosed in double quotes and any embedded double quotes must be escaped using a backslash ("\").
Time Columns
Several of the files include a TIME column that allows you to
specify times when the rule is to be applied. Contents of this column is a
list of timeelements separated by apersands
(&).
Each timeelement is one of the
following:
- timestart=
hh:mm[:ss] Defines the starting time of day.
- timestop=
hh:mm[:ss] Defines the ending time of day.
- contiguous
Added in Shoreawll 5.0.12. When timestop is smaller than timestart value, match this as a single time period instead of distinct intervals. See the Examples below.
- utc
Times are expressed in Greenwich Mean Time.
- localtz
Deprecated by the Netfilter team in favor of kerneltz. Times are expressed in Local Civil Time (default).
- kerneltz
Added in Shorewall 4.5.2. Times are expressed in Local Kernel Time (requires iptables 1.4.12 or later).
- weekdays=ddd[,ddd]...
where
dddis one ofMon,Tue,Wed,Thu,Fri,SatorSun- monthdays=dd[,dd],...
where
ddis an ordinal day of the month- datestart=
yyyy[-mm[-dd[Thh[:mm[:ss]]]]] Defines the starting date and time.
- datestop=
yyyy[-mm[-dd[Thh[:mm[:ss]]]]] Defines the ending date and time.
Examples:
- To match on weekends, use:
weekdays=Sat,Sun
- Or, to match (once) on a national holiday block:
datestart=2016-12-24&datestop=2016-12-27
- Since the stop time is actually inclusive, you would need the following stop time to not match the first second of the new day:
datestart=2016-12-24T17:00&datestop=2016-12-27T23:59:59
- During Lunch Hour
- The fourth Friday in the month:
weekdays=Fri&monthdays=22,23,24,25,26,27,28
- Matching across days might not do what is expected. For instance,
weekdays=Mon×tart=23:00×top=01:00
Will match Monday, for one hour from midnight to 1 a.m., and then again for another hour from 23:00 onwards. If this is unwanted, e.g. if you would like 'match for two hours from Montay 23:00 onwards' you need to also specify the contiguous option in the example above.
Switches
here are times when you would like to enable or disable one or more rules in the configuration without having to do a shorewall reload or shorewall restart. This may be accomplished using the SWITCH column in shorewall-rules (5) or shorewall6-rules (5). Using this column requires that your kernel and iptables include Condition Match Support and you must be running Shorewall 4.4.24 or later. See the output of shorewall show capabilities and shorewall version to determine if you can use this feature.
The SWITCH column contains the name of a switch. Each switch is initially in the off position. You can turn on the switch named switch1 by:
| echo 1 > /proc/net/nf_condition/switch1 |
You can turn it off again by:
| echo 0 > /proc/net/nf_condition/switch1 |
If you simply include the switch name in the SWITCH column, then the rule is enabled only when the switch is on. If you precede the switch name with ! (e.g., !switch1), then the rule is enabled only when the switch is off. Switch settings are retained over shorewall reload.
Shorewall requires that switch names:
begin with a letter and be composed of letters, digits, underscore ('_') or hyphen ('-'); and
be 30 characters or less in length.
Multiple rules can be controlled by the same switch.
Example:
Forward port 80 to dmz host $BACKUP if switch 'primary_down' is on.
#ACTION SOURCE DEST PROTO DPORT SPORT ORIGDEST RATE USER MARK CONNLIMIT TIME HEADERS SWITCH DNAT net dmz:$BACKUP tcp 80 - - - - - - - - primary_down
