SHOREWALL.CONF(5) [FIXME: manual] SHOREWALL.CONF(5)NAMEshorewall.conf - Shorewall global configuration file
SYNOPSIS
/etc/shorewall/shorewall.conf
DESCRIPTION
This file sets options that apply to Shorewall as a whole.
The file consists of Shell comments (lines beginning with '#'), blank
lines and assignment statements (variable=value). If the value contains
shell meta characters or white-space, then it must be enclosed in
quotes. Example: MACLIST_LOG_LEVEL="NFLOG(1,0,1)".
OPTIONS
Many options have as their value a log-level. Log levels are a method
of describing to syslog (8) the importance of a message and a number of
parameters in this file have log levels as their value.
These levels are defined by syslog and are used to determine the
destination of the messages through entries in /etc/syslog.conf (5).
The syslog documentation refers to these as "priorities"; Netfilter
calls them "levels" and Shorewall also uses that term.
Valid levels are:
7 debug
6 info
5 notice
4 warning
3 err
2 crit
1 alert
0 emerg
For most Shorewall logging, a level of 6 (info) is appropriate.
Shorewall log messages are generated by NetFilter and are logged using
facility 'kern' and the level that you specify. If you are unsure of
the level to choose, 6 (info) is a safe bet. You may specify levels by
name or by number.
If you have built your kernel with ULOG and/or NFLOG target support,
you may also specify a log level of ULOG and/or NFLOG (must be all
caps). Rather than log its messages to syslogd, Shorewall will direct
netfilter to log the messages via the ULOG or NFLOG target which will
send them to a process called 'ulogd'. ulogd is available with most
Linux distributions (although it probably isn't installed by default).
Ulogd is also available from
http://www.netfilter.org/projects/ulogd/index.html and can be
configured to log all Shorewall messages to their own log file.
Note
If you want to specify parameters to ULOG or NFLOG (e.g.,
NFLOG(1,0,1)), then you must either quote the setting or you must
escape the parentheses.
Examples:
MACLIST_LOG_LEVEL="NFLOG(1,0,1)"
or
MACLIST_LOG_LEVEL=NFLOG\(1,0,1\)
Beginning with Shorewall 4.4.22, LOGMARK is also a valid level which
logs the packet's mark value along with the other usual information.
The syntax is:
LOGMARK[(priority)]
where priority is one of the levels listed in the list above. If
omitted, the default is info (6).
The following options may be set in shorewall.conf.
ACCEPT_DEFAULT={action[(parameters)][:level]|none}
DROP_DEFAULT={action[(parameters)][:level]|none}
NFQUEUE_DEFAULT={action[(parameters)][:level]|none}
QUEUE_DEFAULT={action[(parameters)][:level]|none}
REJECT_DEFAULT={action[(parameters)][:level]|none}
In earlier Shorewall versions, a "default action" for DROP and
REJECT policies was specified in the file
/usr/share/shorewall/actions.std.
In Shorewall 4.4.0, the DROP_DEFAULT, REJECT_DEFAULT,
ACCEPT_DEFAULT, QUEUE_DEFAULT and NFQUEUE_DEFAULT options were
added.
DROP_DEFAULT describes the rules to be applied before a connection
request is dropped by a DROP policy; REJECT_DEFAULT describes the
rules to be applied if a connection request is rejected by a REJECT
policy. The other three are similar for ACCEPT, QUEUE and NFQUEUE
policies.
The value applied to these may be:
The default values are:
DROP_DEFAULT="Drop"
REJECT_DEFAULT="Reject"
ACCEPT_DEFAULT="none"
QUEUE_DEFAULT="none"
NFQUEUE_DEFAULT="None"
If you set the value of either option to "None" then no default
action will be used and the default action or macro must be
specified in shorewall-policy[1](5).
You can pass parameters to the specified action (e.g.,
myaction(audit,DROP)).
Beginning with Shorewall 4.5.10, the action name can be followed
optionally by a colon and a log level. The level will be applied to
each rule in the action or body that does not already have a log
level.
ACCOUNTING=[Yes|No]
Added in Shorewall 4.4.7. If set to Yes, Shorewall accounting is
enabled (see shorewall-accounting[2](5)). If not specified or set
to the empty value, ACCOUNTING=Yes is assumed.
ACCOUNTING_TABLE=[filter|mangle]
Added in Shorewall 4.4.20. This setting determines which Netfilter
table the accounting rules are added in. By default,
ACCOUNTING_TABLE=filter is assumed. See also
shorewall-accounting[2](5).
ADD_IP_ALIASES=[Yes|No]
This parameter determines whether Shorewall automatically adds the
external address(es) in shorewall-nat[3](5). If the variable is set
to Yes or yes then Shorewall automatically adds these aliases. If
it is set to No or no, you must add these aliases yourself using
your distribution's network configuration tools.
If this variable is not set or is given an empty value
(ADD_IP_ALIASES="") then ADD_IP_ALIASES=Yes is assumed.
Warning
Addresses added by ADD_IP_ALIASES=Yes are deleted and re-added
during shorewall restart. As a consequence, connections using
those addresses may be severed.
ADD_SNAT_ALIASES=[Yes|No]
This parameter determines whether Shorewall automatically adds the
SNAT ADDRESS in shorewall-masq[4](5). If the variable is set to Yes
or yes then Shorewall automatically adds these addresses. If it is
set to No or no, you must add these addresses yourself using your
distribution's network configuration tools.
If this variable is not set or is given an empty value
(ADD_SNAT_ALIASES="") then ADD_SNAT_ALIASES=No is assumed.
Warning
Addresses added by ADD_SNAT_ALIASES=Yes are deleted and
re-added during shorewall restart. As a consequence,
connections using those addresses may be severed.
ADMINISABSENTMINDED=[Yes|No]
The value of this variable affects Shorewall's stopped state. When
ADMINISABSENTMINDED=No, only traffic to/from those addresses listed
in shorewall-routestopped[5](5) is accepted when Shorewall is
stopped. When ADMINISABSENTMINDED=Yes, in addition to traffic
to/from addresses in shorewall-routestopped[5](5), connections that
were active when Shorewall stopped continue to work and all new
connections from the firewall system itself are allowed. If this
variable is not set or is given the empty value then
ADMINISABSENTMINDED=No is assumed.
ARPTABLES=[pathname]
Added in Shorewall 4.5.12. This parameter names the arptables
executable to be used by Shorewall. If not specified or if
specified as a null value, then the arptables executable located
using the PATH option is used.
Regardless of how the arptables utility is located (specified via
arptables= or located via PATH), Shorewall uses the
arptables-restore and arptables-save utilities from that same
directory.
AUTOCOMMENT=[Yes|No]
Formerly named AUTO_COMMENT. If set, if there is not a current
comment when a macro is invoked, the behavior is as if the first
line of the macro file was "COMMENT <macro name>". The AUTO_COMMENT
option has a default value of 'Yes'.
The setting of the AUTOMAKE option is ignored if the start or
restart command includes a directory name (e.g., shorewall restart
/etc/shorewall.new).
AUTOHELPERS=[Yes|No]
Added in Shorewall 4.5.7. When set to Yes (the default), the
generated ruleset will automatically associate helpers with
applications that require them (FTP, IRC, etc.). When configuring
your firewall on systems running kernel 3.5 or later, it is
recommended that you:
1. Set AUTOHELPERS=No.
2. Either:
1. Modify shorewall-conntrack[6] (5) to only apply helpers
where they are required; or
2. Specify the appropriate helper in the HELPER column in
shorewall-rules[7] (5).
Note
The macros for those applications requiring a helper
automatically specify the appropriate HELPER where
required.
AUTOMAKE=[Yes|No]
If set, the behavior of the 'start' command is changed; if no files
in /etc/shorewall have been changed since the last successful start
or restart command, then the compilation step is skipped and the
compiled script that executed the last start or restart command is
used. The default is AUTOMAKE=No.
BLACKLIST=[{ALL|state[,...]}]
where state is one of NEW, ESTABLISHED, RELATED, INVALID,or
UNTRACKED.
Added in Shorewall 4.5.13 to replace the BLACKLISTNEWONLY option
below. Specifies the connection tracking states that are to be
subject to blacklist screening. If neither BLACKLIST nor
BLACKLISTNEWONLY are specified then the states subject to
blacklisting are NEW,ESTABLISHED,INVALID,UNTRACKED.
ALL sends all packets through the blacklist chains.
Note: The ESTABLISHED state may not be specified if FASTACCEPT is
specified.
BLACKLIST_DISPOSITION=[DROP|A_DROP|REJECT|A_REJECT]
This parameter determines the disposition of packets from
blacklisted hosts. It may have the value DROP if the packets are to
be dropped or REJECT if the packets are to be replied with an ICMP
port unreachable reply or a TCP RST (tcp only). If you do not
assign a value or if you assign an empty value then DROP is
assumed.
A_DROP and A_REJECT are audited versions of DROP and REJECT
respectively and were added in Shorewall 4.4.20. They require
AUDIT_TARGET in the kernel and iptables.
The BLACKLIST_DISPOSITION setting has no effect on entries in the
BLACKLIST section of shorewall-rules[7] (5). It determines the
disposition of packets sent to the blacklog target of
shorewall-blrules[8](5).
BLACKLIST_LOG_LEVEL=[log-level]
Formerly named BLACKLIST_LOGLEVEL. This parameter determines if
packets from blacklisted hosts are logged and it determines the
syslog level that they are to be logged at. Its value is a syslog
level (Example: BLACKLIST_LOG_LEVEL=debug). If you do not assign a
value or if you assign an empty value then packets from blacklisted
hosts are not logged. The setting determines the log level of
packets sent to the blacklog target of shorewall-blrules[8](5).
BLACKLISTNEWONLY={Yes|No}
Deprecated in Shorewall 4.5.13 in favor of BLACKLIST above.
When set to Yes or yes, blacklists are only consulted for new
connections and for packets in the INVALID connection state (such
as TCP SYN,ACK when there has been no corresponding SYN). That
includes entries in the shorewall-blrules[9] (5) file and in the
BLACKLIST section of shorewall-rules[7] (5).
When set to No or no, blacklists are consulted for every packet
(will slow down your firewall noticeably if you have large
blacklists). If the BLACKLISTNEWONLY option is not set or is set to
the empty value then BLACKLISTNEWONLY=No is assumed.
Note
BLACKLISTNEWONLY=No is incompatible with FASTACCEPT=Yes.
CHAIN_SCRIPTS={Yes|No}
Added in Shorewall 4.5.16. Prior to the availability of BEGIN
PERL....END PERL in configuration files, the only way to execute a
chain-specific script was to create a script file with the same
name as the chain and place it in a directory on the CONFIG_PATH.
That facility has the drawback that the compiler will attempt to
run a non-script file just because it has the same name as a chain.
To disable this facility, set CHAIN_SCRIPTS=No. If not specified or
specified as the empty value, CHAIN_SCRIPTS=Yes is assumed.
CLAMPMSS=[Yes|No|value]
This parameter enables the TCP Clamp MSS to PMTU feature of
Netfilter and is usually required when your internet connection is
through PPPoE or PPTP. If set to Yes or yes, the feature is
enabled. If left blank or set to No or no, the feature is not
enabled.
Important: This option requires CONFIG_IP_NF_TARGET_TCPMSS in your
kernel.
You may also set CLAMPMSS to a numeric value (e.g., CLAMPMSS=1400).
This will set the MSS field in TCP SYN packets going through the
firewall to the value that you specify.
CLEAR_TC=[Yes|No]
If this option is set to No then Shorewall won't clear the current
traffic control rules during [re]start. This setting is intended
for use by people who prefer to configure traffic shaping when the
network interfaces come up rather than when the firewall is
started. If that is what you want to do, set TC_ENABLED=Yes and
CLEAR_TC=No and do not supply an /etc/shorewall/tcstart file. That
way, your traffic shaping rules can still use the “fwmark”
classifier based on packet marking defined in
shorewall-tcrules[10](5). If not specified, CLEAR_TC=Yes is
assumed.
COMPLETE=[Yes|No]
Added in Shorewall 4.4.12. When you set this option to Yes, you are
asserting that the configuration is complete so that your set of
zones encompasses any hosts that can send or receive traffic
to/from/through the firewall. This causes Shorewall to omit the
rules that catch packets in which the source or destination IP
address is outside of any of your zones. Default is No. It is
recommended that this option only be set to Yes if:
· You have defined an interface whose effective physical setting
is '+'.
· That interface is assigned to a zone.
· You have no CONTINUE policies or rules.
CONFIG_PATH=[directory[:directory]...]
Specifies where configuration files other than shorewall.conf may
be found. CONFIG_PATH is specifies as a list of directory names
separated by colons (":"). When looking for a configuration file
other than shorewall.conf:
· If the command is "try" or a "<configuration directory>" was
specified in the command (e.g., shorewall check ./gateway) then
the directory given in the command is searched first.
· Next, each directory in the CONFIG_PATH setting is searched in
sequence.
If CONFIG_PATH is not given or if it is set to the empty value then
the contents of /usr/share/shorewall/configpath are used. As
released from shorewall.net, that file sets the CONFIG_PATH to
/etc/shorewall:/usr/share/shorewall but your particular
distribution may set it differently. See the output of shorewall
show config for the default on your system.
DEFER_DNS_RESOLUTION=[Yes|No]
Added in Shorewall 4.5.12. When set to 'Yes' (the default), DNS
names are validated in the compiler and then passed on to the
generated script where they are resolved by iptables-restore. This
is an advantage if you use AUTOMAKE=Yes and the IP address
associated with the DNS name is subject to change. When
DEFER_DNS_RESOLUTION=No, DNS names are converted into IP addresses
by the compiler. This has the advantage that when AUTOMAKE=Yes, the
start and restart commands will succeed even if no DNS server is
reachable (assuming that the configuration hasn't changed since the
compiled script was last generated).
DELETE_THEN_ADD={Yes|No}
If set to Yes (the default value), entries in the
/etc/shorewall/route_stopped files cause an 'ip rule del' command
to be generated in addition to an 'ip rule add' command. Setting
this option to No, causes the 'ip rule del' command to be omitted.
DETECT_DNAT_IPADDRS=[Yes|No]
If set to Yes or yes, Shorewall will detect the first IP address of
the interface to the source zone and will include this address in
DNAT rules as the original destination IP address. If set to No or
no, Shorewall will not detect this address and any destination IP
address will match the DNAT rule. If not specified or empty,
“DETECT_DNAT_IPADDRS=Yes” is assumed.
DISABLE_IPV6=[Yes|No]
If set to Yes or yes, IPv6 traffic to, from and through the
firewall system is disabled. If set to No or no, Shorewall will
take no action with respect to allowing or disallowing IPv6
traffic. If not specified or empty, “DISABLE_IPV6=No” is assumed.
It is important to note that changing DISABLE_IPV6=Yes to
DISABLE_IPV6=No does not enable IPV6. The recommended approach for
enabling IPv6 on your system is:
· Install, configure and start Shorewall6[11].
· Change DISABLE_IPV6=Yes to DISABLE_IPV6=No
· Restart Shorewall
DONT_LOAD=[module[,module]...]
Causes Shorewall to not load the listed kernel modules.
DYNAMIC_BLACKLIST={Yes|No}
Added in Shorewall 4.4.7. When set to No or no, dynamic
blacklisting using the shorewall drop, shorewall reject, shorewall
logdrop and shorewall logreject is disabled. Default is Yes.
EXPAND_POLICIES={Yes|No}
Normally, when the SOURCE or DEST columns in shorewall-policy(5)
contains 'all', a single policy chain is created and the policy is
enforced in that chain. For example, if the policy entry is
#SOURCE DEST POLICY LOG
# LEVEL
net all DROP info
then the chain name is 'net2all' which is also the chain named in
Shorewall log messages generated as a result of the policy. If
EXPAND_POLICIES=Yes, then Shorewall will create a separate chain
for each pair of zones covered by the policy. This makes the
resulting log messages easier to interpret since the chain in the
messages will have a name of the form 'a2b' where 'a' is the SOURCE
zone and 'b' is the DEST zone.
EXPORTMODULES=[Yes|No]
Added in Shorewall 4.4.17. When set to Yes when compiling for use
by Shorewall Lite (shorewall load, shorewall reload or shorewall
export commands), the compiler will copy the modules or helpers
file from the administrative system into the script. When set to No
or not specified, the compiler will not copy the modules or helpers
file from /usr/share/shorewall but will copy the found in another
location on the CONFIG_PATH.
When compiling for direct use by Shorewall, causes the contents of
the local module or helpers file to be copied into the compiled
script. When set to No or not set, the compiled script reads the
file itself.
EXPORTPARAMS={Yes|No}
Deprecated in Shorewall 4.4.17.
Beginning with Shorewall 4.4.17, the variables set in the 'params'
file at compile time are available at run time with
EXPORTPARAMS=No. As a consequence, beginning with that version the
recommended setting is EXPORTPARAMS=No.
It is quite difficult to code a 'params' file that assigns other
than constant values such that it works correctly with Shorewall
Lite. The EXPORTPARAMS option works around this problem. When
EXPORTPARAMS=No, the 'params' file is not copied to the compiler
output.
With EXPORTPARAMS=No, if you need to set environmental variables on
the firewall system for use by your extension scripts, then do so
in the init extension script.
The default is EXPORTPARAMS=Yes which is the recommended setting
unless you are using Shorewall Lite.
FASTACCEPT={Yes|No}
Normally, Shorewall defers accepting ESTABLISHED/RELATED packets
until these packets reach the chain in which the original
connection was accepted. So for packets going from the 'loc' zone
to the 'net' zone, ESTABLISHED/RELATED packets are ACCEPTED in the
'loc2net' chain.
If you set FASTACCEPT=Yes, then ESTABLISHED/RELATED packets are
accepted early in the INPUT, FORWARD and OUTPUT chains. If you set
FASTACCEPT=Yes then you may not include rules in the ESTABLISHED or
RELATED sections of shorewall-rules[7](5).
Note
FASTACCEPT=Yes is incompatible with BLACKLISTNEWONLY=No.
FORWARD_CLEAR_MARK={Yes|No}
Added in Shorewall 4.4.11 Beta 3. Traditionally, Shorewall has
cleared the packet mark in the first rule in the mangle FORWARD
chain. This behavior is maintained with the default setting of this
option (FORWARD_CLEAR_MARK=Yes). If FORWARD_CLEAR_MARK is set to
'No', packet marks set in the mangle PREROUTING chain are retained
in the FORWARD chains.
GEOIPDIR=[pathname]
Added in Shorewall 4.5.4. Specifies the pathname of the directory
containing the GeoIP Match database. See
http://www.shorewall.net/ISO-3661.html. If not specified, the
default value is /usr/share/xt_geoip/LE which is the default
location of the little-endian database.
HELPERS=[helper[,helper...]]
Added in Shorewall 4.5.7. This option lists the Netfilter
application helps that are to be enabled. If not specified, the
default is to enable all helpers.
Possible values for helper are:
· amanda
· ftp
· h323
· irc
· netbios-ns
· none - This special value was added in Shorewall 4.5.16 and
indicates that no helpers are to be enabled. It also prevents
the compiler for probing for helper support; such probing
generates messages on the system log of the form "xt_CT: No
such helper XXX" where XXX is the helper name. When used, none
must be the only helper specified.
· pptp
· sane
· sip
· snmp
· tftp
When HELPERS is specified on a system running Kernel 3.5.0 or
later, automatic association of helpers to connections is disabled.
HIGH_ROUTE_MARKS={Yes|No}
Deprecated in Shorewall 4.4.26 in favor of PROVIDER_OFFSET.
Prior to version 3.2.0, it was not possible to use connection
marking in shorewall-tcrules[10](5) if you had a multi-ISP
configuration that uses the track option.
You may set HIGH_ROUTE_MARKS=Yes in to effectively divide the
packet mark and connection mark into two mark fields.
The width of the fields are determined by the setting of
WIDE_TC_MARKS. If WIDE_TC_MARKS=No (the default):
1. The MARK field in the providers file must have a value that is
less than 65536 and that is a multiple of 256 (using hex
representation, the values are 0x0100-0xFF00 with the low-order
8 bits being zero).
2. You may only set those mark values in the PREROUTING chain.
3. Marks used for traffic shaping must still be in the range of
1-255 and may still not be set in the PREROUTING chain.
When WIDE_TC_MARKS=Yes:
1. The MARK field in the providers file must have a value that is
a multiple of 65536 (using hex representation, the values are
0x010000-0xFF0000 with the low-order 16 bits being zero).
2. You may only set those mark values in the PREROUTING chain.
3. Marks used for traffic shaping must be in the range of 1-16383
and may still not be set in the PREROUTING chain.
Regardless of the setting of WIDE_TC_MARKS, when you SAVE or
RESTORE in tcrules, only the TC mark value is saved or restored.
Shorewall handles saving and restoring the routing (provider)
marks.
IGNOREUNKNOWNVARIABLES=[Yes|No]
Added in Shorewall 4.5.11. Normally, if an unknown shell variable
is encountered in a configuration file (except in ?IF and ?ELSIF
directives), the compiler raises a fatal error. If
IGNOREUNKNOWNVARIABLES is set to Yes, then such variables simply
expand to an empty string. Default is No.
IMPLICIT_CONTINUE={Yes|No}
When this option is set to Yes, it causes subzones to be treated
differently with respect to policies.
Subzones are defined by following their name with ":" and a list of
parent zones (in shorewall-zones[12](5)). Normally, you want to
have a set of special rules for the subzone and if a connection
doesn't match any of those subzone-specific rules then you want the
parent zone rules and policies to be applied; see
shorewall-nesting[13](5). With IMPLICIT_CONTINUE=Yes, that happens
automatically.
If IMPLICIT_CONTINUE=No or if IMPLICIT_CONTINUE is not set, then
subzones are not subject to this special treatment. With
IMPLICIT_CONTINUE=Yes, an implicit CONTINUE policy may be
overridden by including an explicit policy (one that does not
specify "all" in either the SOURCE or the DEST columns).
INVALID_DISPOSITION=[A_DROP|A_REJECT|DROP|REJECT|CONTINUE]
Added in Shorewall 4.5.13. Shorewall has traditionally passed
INVALID packets through the NEW section of shorewall-rules[7] (5).
When a packet in INVALID state fails to match any rule in the
INVALID section, the packet is disposed of based on this setting.
The default value is CONTINUE for compatibility with earlier
versions.
INVALID_LOG_LEVEL=log-level
Added in Shorewall 4.5.13. Packets in the INVALID state that do not
match any rule in the INVALID section of shorewall-rules[14] (5)
are logged at this level. The default value is empty which means no
logging is performed.
IP=[pathname]
If specified, gives the pathname of the 'ip' executable. If not
specified, 'ip' is assumed and the utility will be located using
the current PATH setting.
IP_FORWARDING=[On|Off|Keep]
This parameter determines whether Shorewall enables or disables
IPV4 Packet Forwarding (/proc/sys/net/ipv4/ip_forward). Possible
values are:
On or on
packet forwarding will be enabled.
Off or off
packet forwarding will be disabled.
Keep or keep
Shorewall will neither enable nor disable packet forwarding.
If this variable is not set or is given an empty value
(IP_FORWARD="") then IP_FORWARD=On is assumed.
IPSECFILE=zones
This option indicates that zone-related ipsec information is found
in the zones file (shorewall-zones[12](5)). The option indicates to
the compiler that this is not a legacy configuration where the
ipsec information was contained in a separate file. The value of
this option must not be changed and the option must not be deleted.
IPSET=[pathname]
If specified, gives the pathname of the 'ipset' executable. If not
specified, 'ipset' is assumed and the utility will be located using
the current PATH setting.
IPSET_WARNINGS={Yes|No}
Added in Shorewall 4.5.2. Default is Yes. When set, causes the
rules compiler to issue a warning when:
· The compiler is being run by root and an ipset specified in the
configuration does not exists. Only one warning is issued for
each missing ipset.
· When [src] is specified in a destination column and when [dst]
is specified in a source column.
IPTABLES=[pathname]
This parameter names the iptables executable to be used by
Shorewall. If not specified or if specified as a null value, then
the iptables executable located using the PATH option is used.
Regardless of how the iptables utility is located (specified via
IPTABLES= or located via PATH), Shorewall uses the iptables-restore
and iptables-save utilities from that same directory.
KEEP_RT_TABLES={Yes|No}
When set to Yes, this option prevents generated scripts from
altering the /etc/iproute2/rt_tables database when there are
entries in /etc/shorewall/providers. If you set this option to Yes
while Shorewall (Shorewall-lite) is running, you should remove the
file /var/lib/shorewall/rt_tables
(/var/lib/shorewall-lite/rt_tables) before your next stop, refresh,
restore on restart command.
The default is KEEP_RT_TABLES=No.
LEGACY_FASTSTART={Yes|No}
Added in Shorewall 4.4.20. If not specified, the default is Yes
which preserves the legacy behavior of start -f (the modification
times of the files in /etc/shorewall are compare with that of
/var/lib/shorewall/restore). If set to No, then the times are
compared with that of /var/lib/shorewall/firewall, which is
consistent with the way that restart -f works.
LOAD_HELPERS_ONLY={Yes|No}
Added in Shorewall 4.4.7. When set to Yes, restricts the set of
modules loaded by shorewall to those listed in
/var/lib/shorewall/helpers and those that are actually used. When
not set, or set to the empty value, LOAD_HELPERS_ONLY=No is
assumed.
LOCKFILE=[pathname]
Specifies the name of the Shorewall lock file, used to prevent
simultaneous state-changing commands. If not specified,
${VARDIR}/shorewall/lock is assumed (${VARDIR} is normally /var/lib
but can be changed when Shorewall-core is installed -- see the
output of shorewall show vardir).
LOG_MARTIANS=[Yes|No|Keep]
If set to Yes or yes, sets /proc/sys/net/ipv4/conf/*/log_martians
to 1 with the exception of /proc/sys/net/ipv4/conf/all/log_martians
which is set to 0. The default value is Yes which sets both of the
above to one. If you do not enable martian logging for all
interfaces, you may still enable it for individual interfaces using
the logmartians interface option in shorewall-interfaces[15](5).
The value Keep causes Shorewall to ignore the option. If the option
is set to Yes, then martians are logged on all interfaces. If the
option is set to No, then martian logging is disabled on all
interfaces except those specified in shorewall-interfaces[15](5).
LOG_VERBOSITY=[number]
This option controls the amount of information logged to the file
specified in the STARTUP_LOG option.
Values are:
-1 - Logging is disabled
0 - Silent. Only error messages are logged.
1 - Major progress messages logged.
2 - All progress messages logged
If not specified, then -1 is assumed.
LOGALLNEW=[log-level]
This option is intended for use as a debugging aid. When set to a
log level, this option causes Shorewall to generate a logging rule
as the first rule in each builtin chain.
· The table name is used as the chain name in the log prefix.
· The chain name is used as the target in the log prefix.
For example, using the default LOGFORMAT, the log prefix for
logging from the nat table's PREROUTING chain is:
Shorewall:nat:PREROUTING
Important
To help insure that all packets in the NEW state are logged,
rate limiting (LOGBURST and LOGRATE) should be disabled when
using LOGALLNEW. Use LOGALLNEW at your own risk; it may cause
high CPU and disk utilization and you may not be able to
control your firewall after you enable this option.
Caution
Do not use this option if the resulting log messages will be
sent to another system.
LOGFILE=[pathname]
This parameter tells the /sbin/shorewall program where to look for
Shorewall messages when processing the dump, logwatch, show log,
and hits commands. If not assigned or if assigned an empty value,
/var/log/messages is assumed. For further information, see
http://www.shorewall.net/shorewall_logging.html.
LOGFORMAT=["formattemplate"]
The value of this variable generate the --log-prefix setting for
Shorewall logging rules. It contains a “printf” formatting template
which accepts three arguments (the chain name, logging rule number
(optional) and the disposition). To use LOGFORMAT with fireparse,
set it as:
LOGFORMAT="fp=%s:%d a=%s "
If the LOGFORMAT value contains the substring “%d” then the logging
rule number is calculated and formatted in that position; if that
substring is not included then the rule number is not included. If
not supplied or supplied as empty (LOGFORMAT="") then
“Shorewall:%s:%s:” is assumed.
Note
The setting of LOGFORMAT has an effect of the permitted length
of zone names. See shorewall-zones[12] (5).
LOGLIMIT=[[{s|d}:]rate/{sec|min|hour|day}[:burst]]
Added in Shorewall 4.4.12. Limits the logging rate, either overall,
or by source or destination IP address.
If the value starts with 's:' then logging is limited per source
IP. If the value starts with 'd:', then logging is limited per
destination IP. Otherwise, the overall logging rate is limited.
If burst is not specified, then a value of 5 is assumed.
LOGBURST=[burst]
Deprecated in Shorewall 4.4.12.
LOGRATE=[rate/{minute|second}]
Deprecated in Shorewall 4.4.12. These options are ignored when
LOGLIMIT is specified.
These parameters set the match rate and initial burst size for
logged packets. Please see iptables(8) for a description of the
behavior of these parameters (the iptables option --limit is set by
LOGRATE and --limit-burst is set by LOGBURST). If both parameters
are set empty, no rate-limiting will occur. If you supply one of
these, then you should also supply the other.
Example:
LOGRATE=10/minute
LOGBURST=5
For each logging rule, the first time the rule is reached, the
packet will be logged; in fact, since the burst is 5, the first
five packets will be logged. After this, it will be 6 seconds (1
minute divided by the rate of 10) before a message will be logged
from the rule, regardless of how many packets reach it. Also, every
6 seconds, one of the bursts will be regained; if no packets hit
the rule for 30 seconds, the burst will be fully recharged; back
where we started.
LOGTAGONLY=[Yes|No]
Using the default LOGFORMAT, chain names may not exceed 11
characters or truncation of the log prefix may occur. Longer chain
names may be used with log tags if you set LOGTAGONLY=Yes. With
LOGTAGONLY=Yes, if a log tag is specified then the tag is included
in the log prefix in place of the chain name.
Beginning with Shorewall 4.5.12, when LOGTAGONLY=Yes, you have more
control over the generated log prefix. Beginning with that release,
the tag is interpreted as a chain name and a disposition separated
by a comma. So this rule:
#ACTION SOURCE DEST
LOG:info:foo,bar net fw
would generate the following log prefix when using the default
LOGFORMAT setting:
Shorewall:foo:bar:
Similarly,
#ACTION SOURCE DEST
LOG:info:,bar net fw
would generate
Shorewall:net2fw:bar:
MACLIST_DISPOSITION=[ACCEPT|DROP|REJECT|A_DROP|A_REJECT]
Determines the disposition of connections requests that fail MAC
Verification and must have the value ACCEPT (accept the connection
request anyway), REJECT (reject the connection request) or DROP
(ignore the connection request). If not set or if set to the empty
value (e.g., MACLIST_DISPOSITION="") then
MACLIST_DISPOSITION=REJECT is assumed.
A_DROP and A_REJECT are audited versions of DROP and REJECT
respectively and were added in Shorewall 4.4.20. They require
AUDIT_TARGET in the kernel and iptables.
MACLIST_LOG_LEVEL=[log-level]
Determines the syslog level for logging connection requests that
fail MAC Verification. The value must be a valid syslogd log level.
If you don't want to log these connection requests, set to the
empty value (e.g., MACLIST_LOG_LEVEL="").
MACLIST_TABLE=[filter|mangle]
Normally, MAC verification occurs in the filter table (INPUT and
FORWARD) chains. When forwarding a packet from an interface with
MAC verification to a bridge interface, that doesn't work.
This problem can be worked around by setting MACLIST_TABLE=mangle
which will cause Mac verification to occur out of the PREROUTING
chain. Because REJECT isn't available in that environment, you may
not specify MACLIST_DISPOSITION=REJECT or
MACLIST_DISPOSITION=A_REJECT with MACLIST_TABLE=mangle.
MACLIST_TTL=[number]
The performance of configurations with a large numbers of entries
in shorewall-maclist[16](5) can be improved by setting the
MACLIST_TTL variable in shorewall.conf[17](5).
If your iptables and kernel support the "Recent Match" (see the
output of "shorewall check" near the top), you can cache the
results of a 'maclist' file lookup and thus reduce the overhead
associated with MAC Verification.
When a new connection arrives from a 'maclist' interface, the
packet passes through then list of entries for that interface in
shorewall-maclist[16](5). If there is a match then the source IP
address is added to the 'Recent' set for that interface. Subsequent
connection attempts from that IP address occurring within
$MACLIST_TTL seconds will be accepted without having to scan all of
the entries. After $MACLIST_TTL from the first accepted connection
request from an IP address, the next connection request from that
IP address will be checked against the entire list.
If MACLIST_TTL is not specified or is specified as empty (e.g,
MACLIST_TTL="" or is specified as zero then 'maclist' lookups will
not be cached).
MANGLE_ENABLED=[Yes|No]
Determines whether Shorewall will generate rules in the Netfilter
mangle table. Setting MANGLE_ENABLED=No disables all Shorewall
features that require the mangle table. The default is
MANGLE_ENABLED=Yes.
MAPOLDACTIONS=[Yes|No]
This option is included for compatibility with old Shorewall
configuration. New installs should always have MAPOLDACTIONS=No.
MARK_IN_FORWARD_CHAIN=[Yes|No]
If your kernel has a FORWARD chain in the mangle table, you may set
MARK_IN_FORWARD_CHAIN=Yes to cause the marking specified in the
tcrules file to occur in that chain rather than in the PREROUTING
chain. This permits you to mark inbound traffic based on its
destination address when DNAT is in use. To determine if your
kernel has a FORWARD chain in the mangle table, use the
/sbin/shorewall show mangle command; if a FORWARD chain is
displayed then your kernel will support this option. If this option
is not specified or if it is given the empty value (e.g.,
MARK_IN_FORWARD_CHAIN="") then MARK_IN_FORWARD_CHAIN=No is assumed.
MASK_BITS=[number]
Added in Shorewall 4.4.26. Number of bits on the right of the
32-bit packet mark to be masked when clearing the traffic shaping
mark. Must be >= TC_BITS and <= PROVIDER_OFFSET (if PROVIDER_OFFSET
> 0). Default value and the default values of the other mark layout
options is determined as follows:
Table 1. Default Packet Mark Layout
WIDE_TC_MARKS=No, TC_BITS=8,
HIGH_ROUTE_MARKS=No PROVIDER_BITS=8,
PROVIDER_OFFSET=0,
MASK_BITS=8
WIDE_TC_MARKS=No, TC_BITS=8, PROVIDER_BITS=8,
HIGH_ROUTE_MARKS=Yes PROVIDER_OFFSET=8,
MASK_BITS=8
WIDE_TC_MARKS=Yes, TC_BITS=14, PROVIDER_BITS=8,
HIGH_ROUTE_MARKS=No PROVIDER_OFFSET=0,
MASK_BITS=16
WIDE_TC_MARKS=Yes, TC_BITS=14, PROVIDER_BITS=8,
HIGH_ROUTE_MARKS=Yes PROVIDER_OFFSET=16,
MASK_BITS=16
MODULE_SUFFIX=["extension ..."]
The value of this option determines the possible file extensions of
kernel modules. The default value is "ko ko.gz o o.gz gz".
MODULESDIR=[pathname[:pathname]...]
This parameter specifies the directory/directories where your
kernel netfilter modules may be found. If you leave the variable
empty, Shorewall will supply the value "/lib/modules/`uname
-r`/kernel/net/ipv4/netfilter" in versions of Shorewall prior to
3.2.4 and "/lib/modules/`uname
-r`/kernel/net/ipv4/netfilter:/lib/modules/`uname
-r`/kernel/net/ipv4/netfilter" in later versions.
MULTICAST=[Yes|No]
This option will normally be set to 'No' (the default). It should
be set to 'Yes' under the following circumstances:
1. You have an interface that has parallel zones defined via
/etc/shorewall/hosts.
2. You want to forward multicast packets to two or more of those
parallel zones.
In such cases, you will configure a destonly network on each zone
receiving multicasts.
MUTEX_TIMEOUT=[seconds]
The value of this variable determines the number of seconds that
programs will wait for exclusive access to the Shorewall lock file.
After the number of seconds corresponding to the value of this
variable, programs will assume that the last program to hold the
lock died without releasing the lock.
If not set or set to the empty value, a value of 60 (60 seconds) is
assumed.
An appropriate value for this parameter would be twice the length
of time that it takes your firewall system to process a shorewall
restart command.
NFACCT=[pathname]
Added in Shorewall 4.5.7. Specifies the pathname of the nfacct
utility. If not specified, Shorewall will use the PATH setting to
find the program.
NULL_ROUTE_RFC1918=[Yes|No|blackhole|unreachable|prohibit]
When set to Yes, causes Shorewall to null-route the IPv4 address
ranges reserved by RFC1918. The default value is 'No'.
When combined with route filtering (ROUTE_FILTER=Yes or routefilter
in shorewall-interfaces[15](5)), this option ensures that packets
with an RFC1918 source address are only accepted from interfaces
having known routes to networks using such addresses.
Beginning with Shorewall 4.5.15, you may specify blackhole,
unreachable or prohibit to set the type of route to be created. See
http://www.shorewall.net/MultiISP.html#null_routing.
OPTIMIZE=[value]
The specified value enables certain optimizations. Each
optimization category is associated with a power of two. To enable
multiple optimization categories, simply add their corresponding
numbers together.
Beginning with Shorewall 4.5.20, you may specify OPTIMIZE=All to
enable all optimization categories, and you may also specify
OPTIMIZE=None to disable optimization.
· Optimization category 1 - Traditionally, Shorewall has created
rules for the complete matrix of host groups defined by the
zones, interfaces and hosts files[18]. Any traffic that didn't
correspond to an element of that matrix was rejected in one of
the built-in chains. When the matrix is sparse, this results in
lots of largely useless rules.
These extra rules can be eliminated by setting the 1 bit in
OPTIMIZE.
The 1 bit setting also controls the suppression of redundant
wildcard rules (those specifying "all" in the SOURCE or DEST
column). A wildcard rule is considered to be redundant when it
has the same ACTION and Log Level as the applicable policy.
Note
Optimization level 1 is ignored when optimization level 4
is also selected, since level 4 performs similar
optimizations in a more robust way.
· Optimization category 2 - Added in Shorewall 4.4.7. When set,
suppresses superfluous ACCEPT rules in a policy chain that
implements an ACCEPT policy. Any ACCEPT rules that immediately
precede the final blanket ACCEPT rule in the chain are now
omitted.
· Optimization category 4 - Added in Shorewall 4.4.7. When set,
causes short chains (those with less than 2 rules) to be
optimized away. The following chains are excluded from
optimization:
· accounting chains (unless OPTIMIZE_ACCOUNTING=Yes)
· action chains (user-defined)
· 'blacklst' chain
· dynamic
· forwardUPnP
· UPnP (nat table)
Additionally:
· If a built-in chain has a single rule that branches to a
second chain, then the rules from the second chain are
moved to the built-in chain and the target chain is
omitted.
· Chains with no references are deleted.
· Accounting chains are subject to optimization if the
OPTIMIZE_ACCOUNTING option is set to 'Yes'.
· If a chain ends with an unconditional branch to a second
chain (other than to 'reject'), then the branch is deleted
from the first chain and the rules from the second chain
are appended to it.
An additional optimization was added in Shorewall 4.5.4. If the
last rule in a chain is an unqualified jump to a simple target,
then all immediately preceding rules with the same simple
target are omitted.
For example, consider this chain:
-A fw-net -p udp --dport 67:68 -j ACCEPT
-A fw-net -p udp --sport 1194 -j ACCEPT
-A fw-net -p 41 -j ACCEPT
-A fw-net -j ACCEPT
Since all of the rules are jumps to the simple target ACCEPT,
this chain is totally optimized away and jumps to the chain are
replace with jumps to ACCEPT.
· Optimization category 8 - Added in Shorewall 4.4.9. When set,
causes chains with identical rules to be collapsed into a
single chain.
· Optimization category 16 - Added in Shorewall 4.4.26. When set,
causes sequences of compatible rules to be combined into a
single rule. Rules are considered compatible if they differ
only in their destination ports and comments.
A sequence of compatible rules is often generated when macros
are invoked in sequence.
The ability to combine adjacent rules is limited by two
factors:
· Destination port lists may only be combined up to a maximum
of 15 ports, where a port-pair counts as two ports.
· Rules may only be combined until the length of their
concatenated comment reaches 255 characters.
When either of these limits would be exceeded, the current
combined rule is emitted and the compiler attempts to combine
rules beginning with the one that would have exceeded the
limit. Adjacent combined comments are separated by ', '. Empty
comments at the front of a group of combined comments are
replaced by 'Others and'. Empty comments at the end of a group
of combined comments are replaced by 'and others'.
Beginning in Shorewall 4.5.10, this option also suppresses
duplicate adjacent rules and duplicate non-adjacent rules that
don't include mark, connmark, dscp, ecn, set, tos or u32
matches.
Example 1:
Rules with comments "FOO", <empty> and "BAR" would result
in the combined comment "FOO and others, BAR".
Example 2:
Rules with comments <empty>, "FOO" and "BAR" would result
in the combined comment "Others and FOO, BAR". Note:
Optimize level 16 requires "Extended Multi-port Match" in
your iptables and kernel.
The default value is zero which disables all optimizations.
OPTIMIZE_ACCOUNTING=[Yes|No]
Added in Shorewall 4.4.7. If set to Yes, Shorewall accounting
changes are subject to optimization (OPTIMIZE=4,5,6 or 7). If not
specified or set to the empty value, OPTIMIZE_ACCOUNTING=No is
assumed.
PATH=pathname[:pathname]...
Determines the order in which Shorewall searches directories for
executable files.
PERL=pathname
Added in Shorewall 4.4.11 RC1. Specifies the path name of the Perl
executable. Default is /usr/bin/perl. If the pathname specified by
this option does not exist or the named file is not executable,
then Shorewall falls back to /usr/bin/perl/
PROVIDER_BITS=[number]
Added in Shorewall 4.4.26. The number of bits in the 32-bit packet
mark to be used for provider numbers. May be zero. See MASK_BITS
above for default value.
PROVIDER_OFFSET=[number]If
Added in Shorewall 4.4.26. The offset from the right (low-order
end) of the provider number field in the 32-bit packet mark. If
non-zero, must be >= TC_BITS (Shorewall automatically adjusts
PROVIDER_OFFSET's value). PROVIDER_OFFSET + PROVIDER_BITS +
ZONE_BITS must be < 32. See MASK_BITS above for default value.
RCP_COMMAND="command"
RSH_COMMAND="command"
Earlier generations of Shorewall Lite required that remote root
login via ssh be enabled in order to use the load and reload
commands. Beginning with release 3.9.5, you may define an
alternative means for accessing the remote firewall system. In that
release, two new options were added to shorewall.conf:.RS 4
RSH_COMMAND
RCP_COMMAND
The default values for these are as follows:.RS 4 RSH_COMMAND: ssh
${root}@${system} ${command}
RCP_COMMAND: scp ${files}
${root}@${system}:${destination}
Shell variables that will be set when the commands are invoked are as
follows:.RS 4 root - root user. Normally
root but may be overridden using the '-r'
option.
system - The name/IP address
of the remote firewall system.
command - For RSH_COMMAND,
the command to be executed on the firewall system.
files - For RCP_COMMAND, a
space-separated list of files to be copied to the
remote
firewall system.
destination - The directory
on the remote system that the files are to be copied
into.
RELATED_DISPOSITION=[ACCEPT|A_ACCEPT|A_DROP|A_REJECT|DROP|REJECT|CONTINUE]
Added in Shorewall 4.4.27. Shorewall has traditionally ACCEPTed
RELATED packets that don't match any rule in the RELATED section of
shorewall-rules[7] (5). Concern about the safety of this practice
resulted in the addition of this option. When a packet in RELATED
state fails to match any rule in the RELATED section, the packet is
disposed of based on this setting. The default value is ACCEPT for
compatibility with earlier versions.
RELATED_LOG_LEVEL=log-level
Added in Shorewall 4.4.27. Packets in the related state that do not
match any rule in the RELATED section of shorewall-rules[7] (5) are
logged at this level. The default value is empty which means no
logging is performed.
REJECT_ACTION=action
Added in Shorewall 4.5.21. When a REJECT target is specified,
Shorewall normally handles the response as follows:
· If the destination address of the packet is a broadcast or
multicast address, the packet is dropped.
· if the protocol is ICMP (2) then the packet is dropped.
· if the protocol is TCP (6) then the packet is rejected with an
RST.
· if the protocol is UDP (17) then the packet is rejected with an
'port-unreachable' ICMP (ICMP6).
· if the protocol is ICMP (1) then the packet is rejected with a
'host-unreachable' ICMP.
· otherwise, the packet is rejected with a 'host-prohibited'
ICMP.
You can modify this behavior by implementing your own action that
handles REJECT and specifying it's name in this option. The nolog
and inline options will automatically be assumed for the specified
action.
The following action implements the standard behavior:
?format 2
#TARGET SOURCE DEST PROTO
Broadcast(DROP) - - -
DROP - - 2
INLINE - - 6 ; -j REJECT --reject-with tcp-reset
?if __ENHANCED_REJECT
INLINE - - 17 ; -j REJECT
?if __IPV4
INLINE - - 1 ; -j REJECT --reject-with icmp-host-unreachable
INLINE - - - ; -j REJECT --reject-with icmp-host-prohibited
?else
INLINE - - 58 ; -j REJECT --reject-with icmp6-addr-unreachable
INLINE - - - ; -j REJECT --reject-with icmp6-adm-prohibited
?endif
?else
INLINE - - - ; -j REJECT
?endif
REQUIRE_INTERFACE=[Yes|No]
Added in Shorewall 4.4.10. The default is No. If set to Yes, at
least one optional interface must be up in order for the firewall
to be in the started state. Intended to be used with the Shorewall
Init Package[19].
RESTORE_DEFAULT_ROUTE=[Yes|No]
This option determines whether to restore the default route saved
when here are 'balance' providers defined but all of them are down.
The default is RESTORE_DEFAULT_ROUTE=Yes which preserves the
pre-4.2.6 behavior.
RESTORE_DEFAULT_ROUTE=No is appropriate when you don't want a
default route in the main table (USE_DEFAULT_RT=No) or in the
default table (USE_DEFAULT_RT=Yes) when there are no balance
providers available. In that case, RESTORE_DEFAULT_ROUTE=No will
cause any default route in the relevant table to be deleted.
RESTORE_ROUTEMARKS=[Yes|No]
Added in Shorewall 4.5.9. When set to Yes (the default), provider
marks are restored unconditionally at the top of the mangle OUTPUT
and PREROUTING chains, even if the saved mark is zero. When this
option is set to No, the mark is restored even when it is zero. If
you have problems with IPSEC ESP packets not being routed correctly
on output, try setting this option to No.
RESTOREFILE=filename
Specifies the simple name of a file in /var/lib/shorewall to be
used as the default restore script in the shorewall save, shorewall
restore, shorewall forget and shorewall -f start commands.
RETAIN_ALIASES={Yes|No}
During shorewall start, IP addresses to be added as a consequence
of ADD_IP_ALIASES=Yes and ADD_SNAT_ALIASES=Yes are quietly deleted
when shorewall-nat[3](5) and shorewall-masq[4](5) are processed
then are re-added later. This is done to help ensure that the
addresses can be added with the specified labels but can have the
undesirable side effect of causing routes to be quietly deleted.
When RETAIN_ALIASES is set to Yes, existing addresses will not be
deleted. Regardless of the setting of RETAIN_ALIASES, addresses
added during shorewall start are still deleted at a subsequent
shorewall stop or shorewall restart.
ROUTE_FILTER=[Yes|No|Keep]
If this parameter is given the value Yes or yes then route
filtering (anti-spoofing) is enabled on all network interfaces
which are brought up while Shorewall is in the started state. The
default value is no.
The value Keep causes Shorewall to ignore the option. If the option
is set to Yes, then route filtering occurs on all interfaces. If
the option is set to No, then route filtering is disabled on all
interfaces except those specified in shorewall-interfaces[15](5).
Important
If you need to disable route filtering on any interface, then
you must set ROUTE_FILTER=No then set routefilter=1 or
routefilter=2 on those interfaces where you want route
filtering. See shorewall-interfaces[15](5) for additional
details.
RPFILTER_DISPOSITION=[DROP|REJECT|A_DROP|A_REJECT]
Added in Shorewall 4.5.7. Determines the disposition of packets
entering from interfaces the rpfilter option (see
shorewall-interfaces[15](5)). Packets disposed of by this option
are those whose response packets would not be sent through the same
interface receiving the packet.
RPFILTER_LOG_LEVEL=log-level
Added in shorewall 4.5.7. Determines the logging of packets
disposed via the RPFILTER_DISPOSITION. The default value is info.
SAVE_ARPTABLES={Yes|No}
Added in Shorewall 4.5.12. If SAVE_ARPTABLES=Yes, then the current
arptables contents will be saved by shorewall save command and
restored by shorewall restore command. Default value is No.
SAVE_IPSETS={Yes|No}
Re-enabled in Shorewall 4.4.6. If SAVE_IPSETS=Yes, then the current
contents of your ipsets will be saved by the shorewall stop and
shorewall save commands and restored by the shorewall start and
shorewall restore commands.
SFILTER_DISPOSITION=[DROP|REJECT|A_DROP|A_REJECT]
Added in Shorewall 4.4.20. Determines the disposition of packets
matching the sfilter option (see shorewall-interfaces[15](5)) and
of hairpin packets on interfaces without the routeback option.[20]
interfaces without the routeback option.
SFILTER_LOG_LEVEL=log-level
Added on Shorewall 4.4.20. Determines the logging of packets
matching the sfilter option (see shorewall-interfaces[15](5)) and
of hairpin packets on interfaces without the routeback option.[21]
interfaces without the routeback option. The default is info. If
you don't wish for these packets to be logged, use
SFILTER_LOG_LEVEL=none.
SHOREWALL_SHELL=[pathname]
This option is used to specify the shell program to be used to run
the Shorewall compiler and to interpret the compiled script. If not
specified or specified as a null value, /bin/sh is assumed. Using a
light-weight shell such as ash or dash can significantly improve
performance.
SMURF_DISPOSITION=[DROP|A_DROP]
Added in Shorewall 4.4.20. The default setting is DROP which causes
smurf packets (see the nosmurfs option in
shorewall-interfaces[15](5)) to be dropped. A_DROP causes the
packets to be audited prior to being dropped and requires
AUDIT_TARGET support in the kernel and iptables.
SMURF_LOG_LEVEL=[log-level]
Specifies the logging level for smurf packets (see the nosmurfs
option in shorewall-interfaces[15](5)). If set to the empty value (
SMURF_LOG_LEVEL="" ) then smurfs are not logged.
STARTUP_ENABLED={Yes|No}
Determines if Shorewall is allowed to start. As released from
shorewall.net, this option is set to No. When set to Yes or yes,
Shorewall may be started. Used as a guard against Shorewall being
accidentally started before it has been configured.
STARTUP_LOG=[pathname]
If specified, determines where Shorewall will log the details of
each start, restart and refresh command. Logging verbosity is
determined by the setting of LOG_VERBOSITY above.
SUBSYSLOCK=[pathname]
This parameter should be set to the name of a file that the
firewall should create if it starts successfully and remove when it
stops. Creating and removing this file allows Shorewall to work
with your distribution's initscripts. For RedHat and OpenSuSE, this
should be set to /var/lock/subsys/shorewall. For Debian, the value
is /var/lock/shorewall and in LEAF it is /var/run/shorewall.
TC=[pathname]
If specified, gives the pathname of the 'tc' executable. If not
specified, 'tc' is assumed and the utility will be located using
the current PATH setting.
TC_BITS=[number]
The number of bits at the low end of the 32-bit packet mark to be
used for traffic shaping marking. May be zero. See MASK_BITS above
for default value.
TC_ENABLED=[Yes|No|Internal|Simple|Shared]
If you say Yes or yes here, Shorewall will use a script that you
supply to configure traffic shaping. The script must be named
'tcstart' and must be placed in a directory on your CONFIG_PATH.
If you say No or no then traffic shaping is not enabled.
If you set TC_ENABLED=Simple (Shorewall 4.4.6 and later), simple
traffic shaping using shorewall-tcinterfaces[22](5) and
shorewall-tcpri[23](5) is enabled.
If you set TC_ENABLED=Internal or internal or leave the option
empty then Shorewall will use its builtin traffic shaper
(tc4shorewall written by Arne Bernin.
Beginning with Shorewall 4.4.15, you can set TC_ENABLED=Shared.
This allows you to configure the tcdevices and tcclasses in your
Shorewall6 configuration yet make them available to the compiler
when compiling your Shorewall configuration. In addition to setting
TC_ENABLED=Shared, you need to create symbolic links from your
Shorewall configuration directory (normally /etc/shorewall/) to the
tcdevices and tcclasses files in your Shorewall6 configuration
directory (normally /etc/shorewall6/).
TC_EXPERT={Yes|No}
Normally, Shorewall tries to protect users from themselves by
preventing PREROUTING and OUTPUT tcrules from being applied to
packets that have been marked by the 'track' option in
shorewall-providers[24](5).
If you know what you are doing, you can set TC_EXPERT=Yes and
Shorewall will not include these cautionary checks.
TC_PRIOMAP=map
Added in Shorewall 4.4.6. Determines the mapping of a packet's TOS
field to priority bands. See shorewall-tcpri[23](5). The map
consists of 16 space-separated digits with values 1, 2 or 3. A
value of 1 corresponds to Linux priority 0, 2 to Linux priority 1,
and 3 to Linux Priority 2. The first entry gives the priority of
TOS value 0, the second of TOS value 1, and so on. See tc-prio(8)
for additional information.
The default setting is TC_PRIOMAP="2 3 3 3 2 3 1 1 2 2 2 2 2 2 2
2".
TCP_FLAGS_DISPOSITION=[ACCEPT|DROP|REJECT|A_DROP|A_REJECT]
Determines the disposition of TCP packets that fail the checks
enabled by the tcpflags interface option (see
shorewall-interfaces[15](5)) and must have a value of ACCEPT
(accept the packet), REJECT (send an RST response) or DROP (ignore
the packet). If not set or if set to the empty value (e.g.,
TCP_FLAGS_DISPOSITION="") then TCP_FLAGS_DISPOSITION=DROP is
assumed.
A_DROP and A_REJECT are audited versions of DROP and REJECT
respectively and were added in Shorewall 4.4.20. They require
AUDIT_TARGET in the kernel and iptables.
TCP_FLAGS_LOG_LEVEL=[log-level]
Determines the syslog level for logging packets that fail the
checks enabled by the tcpflags interface option. The value must be
a valid syslogd log level. If you don't want to log these packets,
set to the empty value (e.g., TCP_FLAGS_LOG_LEVEL="").
TRACK_PROVIDERS={Yes|No}
Added in Shorewall 4.4.3. When set to Yes, causes the track option
to be assumed on all providers defined in
shorewall-providers[24](5). May be overridden on an individual
provider through use of the notrack option. The default value is
'No'.
Beginning in Shorewall 4.4.6, setting this option to 'Yes' also
simplifies PREROUTING rules in shorewall-tcrules[10](5).
Previously, when TC_EXPERT=No, packets arriving through 'tracked'
provider interfaces were unconditionally passed to the PREROUTING
tcrules. This was done so that tcrules could reset the packet mark
to zero, thus allowing the packet to be routed using the 'main'
routing table. Using the main table allowed dynamic routes (such as
those added for VPNs) to be effective. The rtrules file was created
to provide a better alternative to clearing the packet mark. As a
consequence, passing these packets to PREROUTING complicates things
without providing any real benefit. Beginning with Shorewall 4.4.6,
when TRACK_PROVIDERS=Yes and TC_EXPERT=No, packets arriving through
'tracked' interfaces will not be passed to the PREROUTING rules.
Since TRACK_PROVIDERS was just introduced in 4.4.3, this change
should be transparent to most, if not all, users.
TRACK_RULES={Yes|No}
Added in Shorewall 4.5.20. If set to Yes, causes the compiler to
add a comment to iptables rules to indicate the file name and line
number of the configuration entry that generated the rule. If set
to No (the default), then no such comments are added.
Setting this option to Yes requires the Comments capability in
iptables and kernel.
UNTRACKED_DISPOSITION=[ACCEPT|A_ACCEPT|A_DROP|A_REJECT|DROP|REJECT|CONTINUE]
Added in Shorewall 4.5.13. Shorewall has traditionally passed
UNTRACKED packets through the NEW section of shorewall-rules[7]
(5). When a packet in UNTRACKED state fails to match any rule in
the UNTRACKED section, the packet is disposed of based on this
setting. The default value is CONTINUE for compatibility with
earlier versions.
UNTRACKED_LOG_LEVEL=log-level
Added in Shorewall 4.5.13. Packets in the UNTRACKED state that do
not match any rule in the UNTRACKED section of shorewall-rules[7]
(5) are logged at this level. The default value is empty which
means no logging is performed.
USE_DEFAULT_RT=[Yes|No]
When set to 'Yes', this option causes the Shorewall multi-ISP
feature to create a different set of routing rules which are
resilient to changes in the main routing table. Such changes can
occur for a number of reasons, VPNs going up and down being an
example. The idea is to send packets through the main table prior
to applying any of the Shorewall-generated routing rules. So
changes to the main table will affect the routing of packets by
default.
When USE_DEFAULT_RT=Yes:
1. Both the DUPLICATE and the COPY columns in providers[24](5)
file must remain empty (or contain "-").
2. The default route is added to the the 'default' table rather
than to the main table.
3. balance is assumed unless loose is specified.
4. Packets are sent through the main routing table by a rule with
priority 999. In routing_rules[25](5), the range 1-998 may be
used for inserting rules that bypass the main table.
5. All provider gateways must be specified explicitly in the
GATEWAY column. detect may not be specified..if n .sp
Note
detect may be specified for interfaces whose configuration
is managed by dhcpcd. Shorewall will use dhcpcd's database
to find the interface's gateway.
6. You should disable all default route management outside of
Shorewall. If a default route is added to the main table while
Shorewall is started, then all policy routing will stop working
(except for those routing rules in the priority range 1-998).
If USE_DEFAULT_RT is not set or if it is set to the empty string
then USE_DEFAULT_RT=No is assumed.
USE_PHYSICAL_NAMES=[Yes|No]
Added in Shorewall 4.4.27. Normally, when Shorewall creates a
Netfilter chain that relates to an interface, it uses the
interface's logical name as the base of the chain name. For
example, if the logical name for an interface is OAKLAND, then the
input chain for traffic arriving on that interface would be
'OAKLAND_in'. If this option is set to Yes, then the physical name
of the interface will be used the base of the chain name.
USE_RT_NAMES=[Yes|No]
Added in Shorewall 4.5.15. When set to 'Yes', Shorewall will use
routing table (provider) names in the generated script rather than
table numbers. When set to 'No' (the default), routing table
numbers will be used.
Caution
If you set USE_RT_NAMES=Yes and KEEP_RT_TABLES=Yes, then you
must insure that all of your providers have entries in
/etc/iproute2/rt_tables as well as the following entries:
255 local
254 main
253 default
250 balance
0 unspec
Without these entries, the firewall will fail to start.
VERBOSITY=[number]
Shorewall has traditionally been very noisy (produced lots of
output). You may set the default level of verbosity using the
VERBOSITY OPTION.
Values are:
0 - Silent. You may make it more verbose using the -v
option
1 - Major progress messages displayed
2 - All progress messages displayed (pre Shorewall-3.2.0
behavior)
If not specified, then 2 is assumed.
WARNOLDCAPVERSION=[Yes|No]
Added in Shorewall 4.5.12. When set to Yes (the default), the
compiler issues a warning when it finds a capabilities file that
doesn't specify all of the capabilities supported by the compiler.
When WARNOLDCAPVERSION is set to No, no warning is issued.
WIDE_TC_MARKS={Yes|No}
Deprecated in Shorewall 4.4.26 in favor of TC_BITS and MASK_BITS.
When set to No (the default), traffic shaping marks are 8 bytes
wide (possible values are 1-255). When WIDE_TC_MARKS=Yes, traffic
shaping marks are 14 bytes wide (values 1-16383). The setting of
WIDE_TC_MARKS also has an effect on the HIGH_ROUTE_MARKS option
(see above).
ZONE_BITS=[number]
Added in Shorewall 4.4.26. When non-zero, enables automatic packet
marking by source zone and determines the number of bits in the
32-bit packet mark to be used for the zone mark. Default value is
0.
ZONE2ZONE={2|-}
Added in Shorewall 4.4.4. This option determines how Shorewall
constructs chain names involving zone names and/or 'all'. The
default is '2' (e.g., fw2net).
FILES
/etc/shorewall/shorewall.conf
SEE ALSOshorewall(8), shorewall-accounting(5), shorewall-actions(5),
shorewall-blacklist(5), shorewall-hosts(5), shorewall_interfaces(5),
shorewall-ipsets(5), shorewall-maclist(5), shorewall-masq(5),
shorewall-nat(5), shorewall-netmap(5), shorewall-params(5),
shorewall-policy(5), shorewall-providers(5), shorewall-proxyarp(5),
shorewall-rtrules(5), shorewall-routestopped(5), shorewall-rules(5),
shorewall-tcclasses(5), shorewall-tcdevices(5),
shorewall-tcinterfaces(5), shorewall-tcpri(5), shorewall-tcrules(5),
shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)NOTES
1. shorewall-policy
http://www.shorewall.net/manpages/shorewall-policy.html
2. shorewall-accounting
http://www.shorewall.net/manpages/shorewall-accounting.html
3. shorewall-nat
http://www.shorewall.net/manpages/shorewall-nat.html
4. shorewall-masq
http://www.shorewall.net/manpages/shorewall-masq.html
5. shorewall-routestopped
http://www.shorewall.net/manpages/shorewall-routestopped.html
6. shorewall-conntrack
http://www.shorewall.net/manpages/shorewall-conntrack.html
7. shorewall-rules
http://www.shorewall.net/manpages/shorewall-rules.html
8. shorewall-blrules
http://www.shorewall.net/manpages/shorewall-blrules.html
9. shorewall-blrules
http://www.shorewall.net/manpages/???
10. shorewall-tcrules
http://www.shorewall.net/manpages/shorewall-tcrules.html
11. Shorewall6
http://www.shorewall.net/manpages/../IPv6Support.html
12. shorewall-zones
http://www.shorewall.net/manpages/shorewall-zones.html
13. shorewall-nesting
http://www.shorewall.net/manpages/shorewall-nesting.html
14. shorewall-rules
http://www.shorewall.net/manpages/manpages/shorewall-rules.html
15. shorewall-interfaces
http://www.shorewall.net/manpages/shorewall-interfaces.html
16. shorewall-maclist
http://www.shorewall.net/manpages/shorewall-maclist.html
17. shorewall.conf
http://www.shorewall.net/manpages/shorewall.conf.html
18. the complete matrix of host groups defined by the zones, interfaces
and hosts files
http://www.shorewall.net/manpages/../ScalabilityAndPerformance.html
19. Shorewall Init Package
http://www.shorewall.net/manpages/shorewall-init.html
20. Hairpin packets are packets that are routed out of the same
interface that they arrived on.
21. Hairpin packets are packets that are routed out of the same
interface that they arrived on.
22. shorewall-tcinterfaces
http://www.shorewall.net/manpages/shorewall-tcinterfaces.html
23. shorewall-tcpri
http://www.shorewall.net/manpages/shorewall-tcpri.html
24. shorewall-providers
http://www.shorewall.net/manpages/shorewall-providers.html
25. routing_rules
http://www.shorewall.net/manpages/shorewall-routing_rules.html
[FIXME: source] 12/19/2013 SHOREWALL.CONF(5)
