SHOREWALL6.CONF(5) | [FIXME: manual] | SHOREWALL6.CONF(5) |
NAME¶
shorewall6.conf - Shorewall6 global configuration fileSYNOPSIS¶
/etc/shorewall6/shorewall6.conf
DESCRIPTION¶
This file sets options that apply to Shorewall6 as a whole. The file consists of Shell comments (lines beginning with '#'), blank lines and assignment statements ( variable=value). If the value contains shell metacharacters or white-space, then it must be enclosed in quotes. Example: 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 Shorewall6 also uses that term. Valid levels are:7 debug 6 info 5 notice 4 warning 3 err 2 crit 1 alert 0 emerg
To allow for default rules to be applied when
USE_ACTIONS=No, the DROP_DEFAULT, REJECT_DEFAULT, ACCEPT_DEFAULT,
QUEUE_DEFAULT and NFQUEUE_DEFAULT options have been 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:
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
shorewall6-policy[1](5).
ACCOUNTING=[Yes|No]
a) The name of an
action.
action.
b) The name of a macro
(Shorewall6-shell only)
(Shorewall6-shell only)
c) None or none
The default values are:
DROP_DEFAULT="Drop"
REJECT_DEFAULT="Reject"
ACCEPT_DEFAULT="none"
QUEUE_DEFAULT="none"
NFQUEUE_DEFAULT="None"
If USE_ACTIONS=Yes, then these values refer to action.Drop and action.Reject
respectively. If USE_ACTIONS=No, then these values refer to macro.Drop and
macro.Reject.
Added in Shorewall 4.4.7. If set to Yes,
Shorewall6 accounting is enabled (see shorewall6-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[3](5).
ADMINISABSENTMINDED=[Yes|No]
The value of this variable affects
Shorewall6's stopped state. When ADMINISABSENTMINDED=No, only traffic to/from
those addresses listed in shorewall6-routestopped[4](5) is accepted
when Shorewall6 is stopped. When ADMINISABSENTMINDED=Yes, in addition to
traffic to/from addresses in shorewall6-routestopped[4](5), connections
that were active when Shorewall6 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.
AUTO_COMMENT=[Yes|No]
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'.
AUTOMAKE=[Yes|No]
If set, the behavior of the start and
restart commands is change; 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.
The setting of the AUTOMAKE option is ignored if the start or
restart command includes a directory name (e.g., shorewall6 restart
/etc/shorewall.new).
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. The BLACKLIST_DISPOSITION
setting has no effect on entries in the BLACKLIST section of
shorewall6-rules[5] (5). It determines the disposition of packets sent
to the blacklog target of shorewall6-blrules[6](5).
BLACKLIST_LOGLEVEL=[log-level]
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_LOGLEVEL=debug). If you do not assign a value or if you assign an
empty value then packets from blacklisted hosts are not logged. The
BLACKLIST_LOGLEVEL setting has no effect on entries in the BLACKLIST section
of shorewall6-rules[5] (5). It determines the log level of packets sent
to the blacklog target of shorewall6-blrules[6](5).
BLACKLISTNEWONLY={Yes|No}
When set to Yes or yes,
blacklists are only consulted for new connections. This includes entries in
the shorewall-blrules[7] (5) file and in the BLACKLIST section of
shorewall6-rules[5] (5).
When set to No or no, blacklists are consulted for every packet
(will slow down your firewall noticably 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.
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
Shorewall6 won't clear the current traffic control rules during [re]start.
This setting is intended for use by people that 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/shorewall6/tcstart file. That way, your traffic
shaping rules can still use the “fwmark” classifier based on
packet marking defined in shorewall6-tcrules[8](5). If not specified,
CLEAR_TC=No is assumed.
Warning
If you also run Shorewall and if you have TC_ENABLED=Internal in your
shorewall-conf[9](5), then you will want CLEAR_TC=No in this file.
COMPLETE=[Yes|No]
Added in Shorewall6 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 Shorewall6 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:
CONFIG_PATH=[directory[:directory]...]
•You have defined an interface whose
effective physical setting is '+'.
•That interface is assigned to a
zone.
•You have no CONTINUE policies or
rules.
Specifies where configuration files other than
shorewall6.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 shorewall6.conf:
If CONFIG_PATH is not given or if it is set to the empty value then the contents
of /usr/share/shorewall6/configpath are used. As released from shorewall.net,
that file sets the CONFIG_PATH to
/etc/shorewall6:/usr/share/shorewall6:/usr/share/shorewall but your particular
distribution may set it differently. See the output of shorewall6 show config
for the default on your system.
Note that the setting in /usr/share/shorewall6/configpath is always used to
locate shorewall6.conf.
DELETE_THEN_ADD={Yes|No}
•If the command is "try" or a
"<configuration directory>" was specified in the command
(e.g., shorewall6 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 set to Yes (the default value), entries in
the /etc/shorewall6/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.
DONT_LOAD=[module[,module]...]
Causes Shorewall6 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 shorewall6 drop,
shorewall6 reject, shorewall6 logdrop and shorewall6
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
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]
#SOURCE DEST POLICY LOG # LEVEL net all DROP info
Added in Shorewall 4.4.17. When set to Yes
when compiling for use by Shorewall6 Lite ( shorewall6 load,
shorewall6 reload or shorewall6 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/shorewall6 but will copy the found in
another location on the CONFIG_PATH.
When compiling for direct use by Shorewall6, 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 beginning with 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 Shorewall6 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
running Shorewall6 Lite.
FASTACCEPT={Yes|No}
Normally, Shorewall6 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/RELEATED 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
shorewall6-rules[5](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/ISOCODES.html. If not specified, the default
value is /usr/share/xt_geoip/LE which is the default location of the
little-endian database.
HIGH_ROUTE_MARKS={Yes|No}
Deprecated in Shorewall 4.4.26 in favor of
PROVIDER_OFFSET.
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 the WIDE_TC_MARKS
option.
When WIDE_TC_MARKS=No (the default):
When WIDE_TC_MARKS=Yes:
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.
IMPLICIT_CONTINUE={Yes|No}
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.
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.
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 shorewall6-zones[10](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 shorewall6-nesting[11](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).
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 rather useless parameter determines
whether Shorewall6 enables or disables IPV6 Packet Forwarding on all
interfaces (/proc/sys/net/ipv6/config/all/forwarding). Possible values are:
On or on
If this variable is not set or is given an empty value (IP_FORWARD="")
then IP_FORWARD=On is assumed.
IP6TABLES=[pathname]
packet forwarding will be enabled.
Off or off
packet forwarding will be disabled.
Keep or keep
Shorewall6 will neither enable nor disable
packet forwarding
This parameter names the ip6tables executable
to be used by Shorewall6. If not specified or if specified as a null value,
then the ip6tables executable located using the PATH option is used.
Regardless of how the ip6tables utility is located (specified via IP6TABLES= or
located via PATH), Shorewall6 uses the ip6tables-restore and ip6tables-save
utilities from that same directory.
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:
KEEP_RT_TABLES={Yes|No}
•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.
When set to Yes, this option prevents
scripts generated by Shorewall6 from altering the /etc/iproute2/rt_tables
database when there are entries in /etc/shorewall6/providers. If you set this
option to Yes while Shorewall6 (Shorewall6-lite) is running, you should
remove the file /var/lib/shorewall6/rt_tables
(/var/lib/shorewall6-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 Shorewall6 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/shorewall6 are compare with that of
/var/lib/shorewall6/restore). If set to No, then the times are compared with
that of /var/lib/shorewall6/firewall, which is consistant 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/shorewall6/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 Shorewall6 lock
file, used to prevent simultaneous state-changing commands. If not specified,
${VARDIR}/shorewall6/lock is assumed (${VARDIR} is normally /var/lib but can
be changed when Shorewall-core is installed -- see the output of shorewall6
show vardir).
LOG_VERBOSITY=[number]
This option controls the amount of information
logged to the file specified in the STARTUP_LOG option.
Values are:
LOGALLNEW=[log-level]
-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.This option is intended for use as a debugging
aid. When set to a log level, this option causes Shorewall6 to generate a
logging rule as the first rule in each builtin chain.
For example, using the default LOGFORMAT, the log prefix for logging from the
nat table's PREROUTING chain is:
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]
•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.
Shorewall:nat:PREROUTING
This parameter tells the /sbin/shorewall6
program where to look for Shorewall6 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.
LOGFORMAT=["formattemplate"]
The value of this variable generate the
--log-prefix setting for Shorewall6 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:
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 “Shorewall6:%s:%s:” is
assumed.
Note
The setting of LOGFORMAT has an effect of the permitted length of zone names.
See shorewall6-zones[10] (5).
LOGLIMIT=[[{s|d}:]rate/{sec|min|hour|day}[:burst]]
LOGFORMAT="fp=%s:%d a=%s "
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}]
As of Shorewall 4.4.12, these parameters are
Deprecated.
These parameters set the match rate and initial burst size for logged packets.
Please see ip6tables(8) for a description of the behavior of these parameters
(the ip6tables 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:
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]
LOGRATE=10/minute LOGBURST=5
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.
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
ip6tables.
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 with MACLIST_TABLE=mangle.
MACLIST_TTL=[number]
The performance of configurations with a large
numbers of entries in shorewall-maclist[12](5) can be improved by
setting the MACLIST_TTL variable in shorewall.conf[13](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[12](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.
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/shorewall6 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
MODULE_SUFFIX=["extension ..."]
WIDE_TC_MARKS=No, HIGH_ROUTE_MARKS=No | TC_BITS=8, PROVIDER_BITS=8, PROVIDER_OFFSET=0, MASK_BITS=8 |
WIDE_TC_MARKS=No, HIGH_ROUTE_MARKS=Yes | TC_BITS=8, PROVIDER_BITS=8, PROVIDER_OFFSET=8, MASK_BITS=8 |
WIDE_TC_MARKS=Yes, HIGH_ROUTE_MARKS=No | TC_BITS=14, PROVIDER_BITS=8, PROVIDER_OFFSET=0, MASK_BITS=16 |
WIDE_TC_MARKS=Yes, HIGH_ROUTE_MARKS=Yes | TC_BITS=14, PROVIDER_BITS=8, PROVIDER_OFFSET=16, MASK_BITS=16 |
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, Shorewall6 will supply "/lib/modules/`uname
-r`/kernel/net/ipv4/netfilter:/lib/modules/`uname
-r`/kernel/net/ipv4/netfilter".
MUTEX_TIMEOUT=[seconds]
The value of this variable determines the
number of seconds that programs will wait for exclusive access to the
Shorewall6 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 shorewall6 restart
command.
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.
The default value is zero which disables all optimizations.
OPTIMIZE_ACCOUNTING=[Yes|No]
•Optimization category 1 -
Traditionally, Shorewall has created rules for the complete matrix of host
groups defined by the zones, interfaces and hosts files[14]. 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.
•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
preceed 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:
Additionally:
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:
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.
•accounting chains (unless
OPTIMIZE_ACCOUNTING=Yes)
•action chains (user-defined)
•'blacklst' chain
•dynamic
•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.
-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
•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 combatible rules is often generated when macros are invoked in
sequence.
The ability to combine adjacent rules is limited by two factors:
When either of these limits would be exceeded, the current combined rule is
emitted and the compiler attemts 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'.
Example 1:
•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 concatinated comment reaches 255 characters.
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 reult in the combined comment
"Others and FOO, BAR". Note: Optimize level 16 requires
"Extended Multi-port Match" in your iptables and kernel.
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 Shorewall6
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 Shorewall6 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]
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"
Eariler generations of Shorewall6 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 shorewall6.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 envoked are as
follows:.RS 4 root - root user. Normally
${root}@${system}:${destination}
root but may be overridden using the '-r'
option.
system - The name/IP address
of the remote firewall system.
of the remote firewall system.
command - For RSH_COMMAND,
the command to be executed on the firewall system.
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.
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]
on the remote system that the files are to be copied
into.
Added in Shorewall 4.4.27. Shorewall has
traditionally ACCEPTed RELATED packets that don't match any rule in the
RELATED section of shorewall6-rules[15] (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
shorewall6-rules[16] (5) are logged at this level. The default value is
empty which means no logging is performed.
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[17].
RESTOREFILE=filename
Specifies the simple name of a file in
/var/lib/shorewall6 to be used as the default restore script in the
shorewall6 save, shorewall6 restore, shorewall6 forget
and shorewall6 -f start commands.
SHOREWALL_SHELL=[pathname]
This option is used to specify the shell
program to be used 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[18](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 ip6tables.
SMURF_LOG_LEVEL=[log-level]
Specifies the logging level for smurf packets
(see the nosmurfs option in shorewall6-interfaces[19](5)). If set to
the empty value ( SMURF_LOG_LEVEL="" ) then smurfs are not
logged.
SFILTER_DISPOSITION=[DROP|REJECT|A_DROP|A_REJECT]
Added in Shorewall 4.4.20. Determines the
disposition of packets matching the filter option (see
shorewall6-interfaces[19](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 filter option (see
shorewall6-interfaces[19](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.
STARTUP_ENABLED={Yes|No}
Determines if Shorewall6 is allowed to start.
As released from shorewall.net, this option is set to No. When set to
Yes or yes, Shorewall6 may be started. Used as a guard against
Shorewall6 being accidentally started before it has been configured.
STARTUP_LOG=[pathname]
If specified, determines where Shorewall6 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 Shorewall6 to work with your
distribution's initscripts. For RedHat, this should be set to
/var/lock/subsys/shorewall6. For Debian, the value is /var/lock/shorewall6 and
in LEAF it is /var/run/shorwall.
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]
Added in Shorewall 4.4.26. 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|Shared]
If you say Yes or yes here,
Shorewall6 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=Internal or internal or leave the option empty then
Shorewall6 will use its builtin traffic shaper (tc4shorewall6 written by Arne
Bernin.
Beginning with Shorewall 4.4.15, if you set TC_ENABLED=Shared or shared, then
you should create symbolic links from your Shorewall6 configuration directory
(normally /etc/shorewall6/) to your Shorewall tcdevices and tcclasses files.
This allows the compiler to have access to your Shorewall traffic shaping
configuration so that it can validate CLASSIFY rules in
shorewall6-tcrules[22] (5).
Warning
If you also run Shorewall and if you have TC_ENABLED=Internal in your
shorewall-conf[9](5), then you will want TC_ENABLED=No or
TC_ENABLED=Shared in this file.
TC_EXPERT={Yes|No}
Normally, Shorewall6 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
shorewall6-providers[23](5).
If you know what you are doing, you can set TC_EXPERT=Yes and Shorewall6 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
shorewall6-tcpri[24](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]
Determines the disposition of TCP packets that
fail the checks enabled by the tcpflags interface option (see
shorewall6-interfaces[19](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.
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
shorewall6-providers[23](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 shorewall6-tcrules[8](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
shorewall6-rtrules[25](5) 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.
USE_DEFAULT_RT=[Yes|No]
Added in Shorewall6 4.4.25. When set to 'Yes',
this option causes the Shorewall6 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 Shorewall6-generated routing rules. So changes to the main
table will affect the routing of packets by default.
When USE_DEFAULT_RT=Yes:
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]
1.Both the DUPLICATE and the COPY columns in
shorewall6-providers[23](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 shorewall6-routing_rules[26](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.
6.You should disable all default route
management outside of Shorewall6. 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).
Added in Shorewall 4.4.27. Normally, when
Shorewall creates a Netfilter chain that relates to an interface, it uses the
interfaces'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.
VERBOSITY=[number]
Shorewall6 has traditionally been very noisy
(produced lots of output). You may set the default level of verbosity using
the VERBOSITY OPTION.
Values are:
WIDE_TC_MARKS={Yes|No}
0 - Silent. You may make it more verbose using
the -v
option
option
1 - Major progress messages displayed
2 - All progress messages displayed (pre
Shorewall6-3.2.0
behavior)
If not specified, then 2 is assumed.behavior)
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/shorewall6/shorewall6.confSEE ALSO¶
shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5), shorewall6-blacklist(5), shorewall6-hosts(5), shorewall6-interfaces(5), shorewall6-ipsec(5), shorewall6-maclist(5), shorewall6-masq(5), shorewall6-nat(5), shorewall6-netmap(5), shoewall6-netmap(5),shorewall6-params(5), shorewall6-policy(5), shorewall6-providers(5), shorewall6-proxyarp(5), shorewall6-rtrules(5), shorewall6-routestopped(5), shorewall6-rules(5), shorewall6-tcclasses(5), shorewall6-tcdevices(5), shorewall6-tcrules(5), shorewall6-tos(5), shorewall6-tunnels(5), shorewall6-zones(5)NOTES¶
- 1.
- shorewall6-policy
- 2.
- shorewall6-accounting
- 3.
- shorewall-accounting
- 4.
- shorewall6-routestopped
- 5.
- shorewall6-rules
- 6.
- shorewall6-blrules
- 7.
- shorewall-blrules
- 8.
- shorewall6-tcrules
- 9.
- shorewall-conf
- 10.
- shorewall6-zones
- 11.
- shorewall6-nesting
- 12.
- shorewall-maclist
- 13.
- shorewall.conf
- 14.
- the complete matrix of host groups defined by the zones, interfaces and hosts files
- 15.
- shorewall6-rules
- 16.
- shorewall6-rules
- 17.
- Shorewall Init Package
- 18.
- shorewall-interfaces
- 19.
- shorewall6-interfaces
- 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.
- shorewall6-tcrules
- 23.
- shorewall6-providers
- 24.
- shorewall6-tcpri
- 25.
- shorewall6-rtrules
- 26.
- shorewall6-routing_rules
06/28/2012 | [FIXME: source] |