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NetBSD 6.1.5 - man page for pfctl (netbsd section 8)

PFCTL(8)			   BSD System Manager's Manual				 PFCTL(8)

     pfctl -- control the packet filter (PF) and network address translation (NAT) device

     pfctl [-AdeghmNnOqRrvz] [-a anchor] [-D macro= value] [-F modifier] [-f file] [-i interface]
	   [-K host | network] [-k host | network] [-o level] [-p device] [-s modifier] [-t table
	   -T command [address ...]] [-x level]

     The pfctl utility communicates with the packet filter device using the ioctl interface
     described in pf(4).  It allows ruleset and parameter configuration and retrieval of status
     information from the packet filter.

     Packet filtering restricts the types of packets that pass through network interfaces enter-
     ing or leaving the host based on filter rules as described in pf.conf(5).	The packet filter
     can also replace addresses and ports of packets.  Replacing source addresses and ports of
     outgoing packets is called NAT (Network Address Translation) and is used to connect an
     internal network (usually reserved address space) to an external one (the Internet) by mak-
     ing all connections to external hosts appear to come from the gateway.  Replacing destina-
     tion addresses and ports of incoming packets is used to redirect connections to different
     hosts and/or ports.  A combination of both translations, bidirectional NAT, is also sup-
     ported.  Translation rules are described in pf.conf(5).

     When the variable pf is set to YES in rc.conf(5), the rule file specified with the variable
     pf_rules is loaded automatically by the rc(8) scripts and the packet filter is enabled.

     The packet filter does not itself forward packets between interfaces.  Forwarding can be
     enabled by setting the sysctl(8) variables net.inet.ip.forwarding and/or
     net.inet6.ip6.forwarding to 1.  Set them permanently in /etc/sysctl.conf.

     The pfctl utility provides several commands.  The options are as follows:

     -A      Load only the queue rules present in the rule file.  Other rules and options are

     -a anchor
	     Apply flags -f, -F, and -s only to the rules in the specified anchor.  In addition
	     to the main ruleset, pfctl can load and manipulate additional rulesets by name,
	     called anchors.  The main ruleset is the default anchor.

	     Anchors are referenced by name and may be nested, with the various components of the
	     anchor path separated by '/' characters, similar to how file system hierarchies are
	     laid out.	The last component of the anchor path is where ruleset operations are

	     Evaluation of anchor rules from the main ruleset is described in pf.conf(5).

	     For example, the following will show all filter rules (see the -s flag below) inside
	     the anchor ``authpf/smith(1234)'', which would have been created for user ``smith''
	     by authpf(8), PID 1234:

		   # pfctl -a "authpf/smith(1234)" -s rules

	     Private tables can also be put inside anchors, either by having table statements in
	     the pf.conf(5) file that is loaded in the anchor, or by using regular table com-
	     mands, as in:

		   # pfctl -a foo/bar -t mytable -T add

	     When a rule referring to a table is loaded in an anchor, the rule will use the pri-
	     vate table if one is defined, and then fall back to the table defined in the main
	     ruleset, if there is one.	This is similar to C rules for variable scope.	It is
	     possible to create distinct tables with the same name in the global ruleset and in
	     an anchor, but this is often bad design and a warning will be issued in that case.

	     By default, recursive inline printing of anchors applies only to unnamed anchors
	     specified inline in the ruleset.  If the anchor name is terminated with a '*' char-
	     acter, the -s flag will recursively print all anchors in a brace delimited block.
	     For example the following will print the ``authpf'' ruleset recursively:

		   # pfctl -a 'authpf/*' -sr

	     To print the main ruleset recursively, specify only '*' as the anchor name:

		   # pfctl -a '*' -sr

     -D macro=value
	     Define macro to be set to value on the command line.  Overrides the definition of
	     macro in the ruleset.

     -d      Disable the packet filter.

     -e      Enable the packet filter.

     -F modifier
	     Flush the filter parameters specified by modifier (may be abbreviated):

	     -F nat	   Flush the NAT rules.
	     -F queue	   Flush the queue rules.
	     -F rules	   Flush the filter rules.
	     -F states	   Flush the state table (NAT and filter).
	     -F Sources    Flush the source tracking table.
	     -F info	   Flush the filter information (statistics that are not bound to rules).
	     -F Tables	   Flush the tables.
	     -F osfp	   Flush the passive operating system fingerprints.
	     -F all	   Flush all of the above.

     -f file
	     Load the rules contained in file.	This file may contain macros, tables, options,
	     and normalization, queueing, translation, and filtering rules.  With the exception
	     of macros and tables, the statements must appear in that order.

     -g      Include output helpful for debugging.

     -h      Help.

     -i interface
	     Restrict the operation to the given interface.

     -K host | network
	     Kill all of the source tracking entries originating from the specified host or
	     network.  A second -K host or -K network option may be specified, which will kill
	     all the source tracking entries from the first host/network to the second.

     -k host | network
	     Kill all of the state entries originating from the specified host or network.  A
	     second -k host or -k network option may be specified, which will kill all the state
	     entries from the first host/network to the second.  For example, to kill all of the
	     state entries originating from ``host'':

		   # pfctl -k host

	     To kill all of the state entries from ``host1'' to ``host2'':

		   # pfctl -k host1 -k host2

	     To kill all states originating from to

		   # pfctl -k -k

	     A network prefix length of 0 can be used as a wildcard.  To kill all states with the
	     target ``host2'':

		   # pfctl -k -k host2

     -m      Merge in explicitly given options without resetting those which are omitted.  Allows
	     single options to be modified without disturbing the others:

		   # echo "set loginterface fxp0" | pfctl -mf -

     -N      Load only the NAT rules present in the rule file.	Other rules and options are

     -n      Do not actually load rules, just parse them.

     -O      Load only the options present in the rule file.  Other rules and options are

     -o level
	     Control the ruleset optimizer, overriding any rule file settings.

	     -o none	   Disable the ruleset optimizer.
	     -o basic	   Enable basic ruleset optimizations.	This is the default behaviour.
	     -o profile    Enable basic ruleset optimizations with profiling.
	     For further information on the ruleset optimizer, see pf.conf(5).

     -p device
	     Use the device file device instead of the default /dev/pf.

     -q      Only print errors and warnings.

     -R      Load only the filter rules present in the rule file.  Other rules and options are

     -r      Perform reverse DNS lookups on states when displaying them.

     -s modifier
	     Show the filter parameters specified by modifier (may be abbreviated):

	     -s nat	    Show the currently loaded NAT rules.
	     -s queue	    Show the currently loaded queue rules.  When used together with -v,
			    per-queue statistics are also shown.  When used together with -v -v,
			    pfctl will loop and show updated queue statistics every five seconds,
			    including measured bandwidth and packets per second.
	     -s rules	    Show the currently loaded filter rules.  When used together with -v,
			    the per-rule statistics (number of evaluations, packets and bytes)
			    are also shown.  Note that the ``skip step'' optimization done auto-
			    matically by the kernel will skip evaluation of rules where possible.
			    Packets passed statefully are counted in the rule that created the
			    state (even though the rule isn't evaluated more than once for the
			    entire connection).
	     -s Anchors     Show the currently loaded anchors directly attached to the main rule-
			    set.  If -a anchor is specified as well, the anchors loaded directly
			    below the given anchor are shown instead.  If -v is specified, all
			    anchors attached under the target anchor will be displayed recur-
	     -s states	    Show the contents of the state table.
	     -s Sources     Show the contents of the source tracking table.
	     -s info	    Show filter information (statistics and counters).	When used
			    together with -v, source tracking statistics are also shown.
	     -s labels	    Show per-rule statistics (label, evaluations, packets total, bytes
			    total, packets in, bytes in, packets out, bytes out) of filter rules
			    with labels, useful for accounting.
	     -s timeouts    Show the current global timeouts.
	     -s memory	    Show the current pool memory hard limits.
	     -s Tables	    Show the list of tables.
	     -s osfp	    Show the list of operating system fingerprints.
	     -s Interfaces  Show the list of interfaces and interface drivers available to PF.
			    When used together with -v, it additionally lists which interfaces
			    have skip rules activated.	When used together with -vv, interface
			    statistics are also shown.	-i can be used to select an interface or
			    a group of interfaces.
	     -s all	    Show all of the above, except for the lists of interfaces and operat-
			    ing system fingerprints.

     -T command [address ...]
	     Specify the command (may be abbreviated) to apply to the table.  Commands include:

	     -T kill	   Kill a table.
	     -T flush	   Flush all addresses of a table.
	     -T add	   Add one or more addresses in a table.  Automatically create a nonex-
			   isting table.
	     -T delete	   Delete one or more addresses from a table.
	     -T expire number
			   Delete addresses which had their statistics cleared more than number
			   seconds ago.  For entries which have never had their statistics
			   cleared, number refers to the time they were added to the table.
	     -T replace    Replace the addresses of the table.	Automatically create a nonexist-
			   ing table.
	     -T show	   Show the content (addresses) of a table.
	     -T test	   Test if the given addresses match a table.
	     -T zero	   Clear all the statistics of a table.
	     -T load	   Load only the table definitions from pf.conf(5).  This is used in con-
			   junction with the -f flag, as in:

				 # pfctl -Tl -f pf.conf

	     For the add, delete, replace, and test commands, the list of addresses can be speci-
	     fied either directly on the command line and/or in an unformatted text file, using
	     the -f flag.  Comments starting with a '#' are allowed in the text file.  With these
	     commands, the -v flag can also be used once or twice, in which case pfctl will print
	     the detailed result of the operation for each individual address, prefixed by one of
	     the following letters:

	     A	  The address/network has been added.
	     C	  The address/network has been changed (negated).
	     D	  The address/network has been deleted.
	     M	  The address matches (test operation only).
	     X	  The address/network is duplicated and therefore ignored.
	     Y	  The address/network cannot be added/deleted due to conflicting '!' attributes.
	     Z	  The address/network has been cleared (statistics).

	     Each table maintains a set of counters that can be retrieved using the -v flag of
	     pfctl.  For example, the following commands define a wide open firewall which will
	     keep track of packets going to or coming from the OpenBSD FTP server.  The following
	     commands configure the firewall and send 10 pings to the FTP server:

		   # printf "table <test> { ftp.NetBSD.org }\n \
		       pass out to <test>\n" | pfctl -f-
		   # ping -qc10 ftp.NetBSD.org

	     We can now use the table show command to output, for each address and packet direc-
	     tion, the number of packets and bytes that are being passed or blocked by rules ref-
	     erencing the table.  The time at which the current accounting started is also shown
	     with the ``Cleared'' line.

		   # pfctl -t test -vTshow
		       Cleared:     Thu Feb 13 18:55:18 2003
		       In/Block:    [ Packets: 0	Bytes: 0	]
		       In/Pass:     [ Packets: 10	Bytes: 840	]
		       Out/Block:   [ Packets: 0	Bytes: 0	]
		       Out/Pass:    [ Packets: 10	Bytes: 840	]

	     Similarly, it is possible to view global information about the tables by using the
	     -v modifier twice and the -s Tables command.  This will display the number of
	     addresses on each table, the number of rules which reference the table, and the
	     global packet statistics for the whole table:

		   # pfctl -vvsTables
		   --a-r-  test
		       Addresses:   1
		       Cleared:     Thu Feb 13 18:55:18 2003
		       References:  [ Anchors: 0	Rules: 1	]
		       Evaluations: [ NoMatch: 3496	Match: 1	]
		       In/Block:    [ Packets: 0	Bytes: 0	]
		       In/Pass:     [ Packets: 10	Bytes: 840	]
		       In/XPass:    [ Packets: 0	Bytes: 0	]
		       Out/Block:   [ Packets: 0	Bytes: 0	]
		       Out/Pass:    [ Packets: 10	Bytes: 840	]
		       Out/XPass:   [ Packets: 0	Bytes: 0	]

	     As we can see here, only one packet - the initial ping request - matched the table,
	     but all packets passing as the result of the state are correctly accounted for.
	     Reloading the table(s) or ruleset will not affect packet accounting in any way.  The
	     two ``XPass'' counters are incremented instead of the ``Pass'' counters when a
	     ``stateful'' packet is passed but doesn't match the table anymore.  This will happen
	     in our example if someone flushes the table while the ping(8) command is running.

	     When used with a single -v, pfctl will only display the first line containing the
	     table flags and name.  The flags are defined as follows:

	     c	  For constant tables, which cannot be altered outside pf.conf(5).
	     p	  For persistent tables, which don't get automatically killed when no rules refer
		  to them.
	     a	  For tables which are part of the active tableset.  Tables without this flag do
		  not really exist, cannot contain addresses, and are only listed if the -g flag
		  is given.
	     i	  For tables which are part of the inactive tableset.  This flag can only be wit-
		  nessed briefly during the loading of pf.conf(5).
	     r	  For tables which are referenced (used) by rules.
	     h	  This flag is set when a table in the main ruleset is hidden by one or more
		  tables of the same name from anchors attached below it.

     -t table
	     Specify the name of the table.

     -v      Produce more verbose output.  A second use of -v will produce even more verbose out-
	     put including ruleset warnings.  See the previous section for its effect on table

     -x level
	     Set the debug level (may be abbreviated) to one of the following:

	     -x none	   Don't generate debug messages.
	     -x urgent	   Generate debug messages only for serious errors.
	     -x misc	   Generate debug messages for various errors.
	     -x loud	   Generate debug messages for common conditions.

     -z      Clear per-rule statistics.

     /etc/pf.conf  Packet filter rules file.
     /etc/pf.os    Passive operating system fingerprint database.

     pf(4), pf.conf(5), pf.os(5), rc.conf(5), authpf(8), ftp-proxy(8), rc(8), sysctl(8)

     The pfctl program and the pf(4) filter mechanism first appeared in OpenBSD 3.0.

BSD					   May 31, 2007 				      BSD

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