1 .\" $OpenBSD: pfctl.8,v 1.138 2008/06/10 20:55:02 mcbride Exp $
3 .\" Copyright (c) 2001 Kjell Wooding. All rights reserved.
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34 .Nd control the packet filter (PF) device
38 .Op Fl AdeghMmNnOPqRrvz
40 .Oo Fl D Ar macro Ns =
45 .Op Fl K Ar host | network
48 .Ar host | network | label | id | gateway
63 utility communicates with the packet filter device using the
64 ioctl interface described in
66 It allows ruleset and parameter configuration and retrieval of status
67 information from the packet filter.
69 Packet filtering restricts the types of packets that pass through
70 network interfaces entering or leaving the host based on filter
73 The packet filter can also replace addresses and ports of packets.
74 Replacing source addresses and ports of outgoing packets is called
75 NAT (Network Address Translation) and is used to connect an internal
76 network (usually reserved address space) to an external one (the
77 Internet) by making all connections to external hosts appear to
78 come from the gateway.
79 Replacing destination addresses and ports of incoming packets
80 is used to redirect connections to different hosts and/or ports.
81 A combination of both translations, bidirectional NAT, is also
83 Translation rules are described in
92 the rule file specified with the variable
94 is loaded automatically by the
96 scripts and the packet filter is enabled.
98 The packet filter does not itself forward packets between interfaces.
99 Forwarding can be enabled by setting the
102 .Em net.inet.ip.forwarding
104 .Em net.inet6.ip6.forwarding
106 Set them permanently in
111 utility provides several commands.
112 The options are as follows:
115 Load only the queue rules present in the rule file.
116 Other rules and options are ignored.
123 only to the rules in the specified
125 In addition to the main ruleset,
127 can load and manipulate additional rulesets by name,
129 The main ruleset is the default anchor.
131 Anchors are referenced by name and may be nested,
132 with the various components of the anchor path separated by
134 characters, similar to how file system hierarchies are laid out.
135 The last component of the anchor path is where ruleset operations are
140 rules from the main ruleset is described in
143 For example, the following will show all filter rules (see the
145 flag below) inside the anchor
146 .Dq authpf/smith(1234) ,
147 which would have been created for user
152 .Bd -literal -offset indent
153 # pfctl -a "authpf/smith(1234)" -s rules
156 Private tables can also be put inside anchors, either by having table
159 file that is loaded in the anchor, or by using regular table commands, as in:
160 .Bd -literal -offset indent
161 # pfctl -a foo/bar -t mytable -T add 1.2.3.4 5.6.7.8
164 When a rule referring to a table is loaded in an anchor, the rule will use the
165 private table if one is defined, and then fall back to the table defined in the
166 main ruleset, if there is one.
167 This is similar to C rules for variable scope.
168 It is possible to create distinct tables with the same name in the global
169 ruleset and in an anchor, but this is often bad design and a warning will be
172 By default, recursive inline printing of anchors applies only to unnamed
173 anchors specified inline in the ruleset.
174 If the anchor name is terminated with a
178 flag will recursively print all anchors in a brace delimited block.
179 For example the following will print the
182 .Bd -literal -offset indent
183 # pfctl -a 'authpf/*' -sr
186 To print the main ruleset recursively, specify only
189 .Bd -literal -offset indent
192 .It Fl D Ar macro Ns = Ns Ar value
198 Overrides the definition of
202 Disable the packet filter.
204 Enable the packet filter.
206 Flush the filter parameters specified by
208 (may be abbreviated):
210 .Bl -tag -width xxxxxxxxxxxx -compact
214 Flush the queue rules.
216 Flush the filter rules.
218 Flush the state table (NAT and filter).
220 Flush the source tracking table.
222 Flush the filter information (statistics that are not bound to rules).
226 Flush the passive operating system fingerprints.
228 Flush all of the above.
231 Load the rules contained in
235 may contain macros, tables, options, and normalization, queueing,
236 translation, and filtering rules.
237 With the exception of macros and tables, the statements must appear in that
240 Include output helpful for debugging.
243 .It Fl i Ar interface
244 Restrict the operation to the given
246 .It Fl K Ar host | network
247 Kill all of the source tracking entries originating from the specified
255 option may be specified, which will kill all the source tracking
256 entries from the first host/network to the second.
259 .Ar host | network | label | id | gateway
261 Kill all of the state entries matching the specified
269 For example, to kill all of the state entries originating from
278 option may be specified, which will kill all the state entries
279 from the first host/network to the second.
280 To kill all of the state entries from
285 .Dl # pfctl -k host1 -k host2
287 To kill all states originating from 192.168.1.0/24 to 172.16.0.0/16:
289 .Dl # pfctl -k 192.168.1.0/24 -k 172.16.0.0/16
291 A network prefix length of 0 can be used as a wildcard.
292 To kill all states with the target
295 .Dl # pfctl -k 0.0.0.0/0 -k host2
297 It is also possible to kill states by rule label or state ID.
298 In this mode the first
300 argument is used to specify the type
301 of the second argument.
302 The following command would kill all states that have been created
303 from rules carrying the label
306 .Dl # pfctl -k label -k foobar
308 To kill one specific state by its unique state ID
309 (as shown by pfctl -s state -vv),
312 modifier and as a second argument the state ID and optional creator ID.
313 To kill a state with ID 4823e84500000003 use:
315 .Dl # pfctl -k id -k 4823e84500000003
317 To kill a state with ID 4823e84500000018 created from a backup
318 firewall with hostid 00000002 use:
320 .Dl # pfctl -k id -k 4823e84500000018/2
322 It is also possible to kill states created from a rule with the route-to/reply-to
323 parameter set to route the connection through a particular gateway.
324 Note that rules routing via the default routing table (not via a route-to
325 rule) will have their rt_addr set as 0.0.0.0 or ::.
326 To kill all states using a gateway of 192.168.0.1 use:
328 .Dl # pfctl -k gateway -k 192.168.0.1
330 A network prefix length can also be specified.
331 To kill all states using a gateway in 192.168.0.0/24:
333 .Dl # pfctl -k gateway -k 192.168.0.0/24
336 Kill matching states in the opposite direction (on other interfaces) when
338 This applies to states killed using the -k option and also will apply to the
339 flush command when flushing states.
340 This is useful when an interface is specified when flushing states.
343 .Dl # pfctl -M -i interface -Fs
346 Merge in explicitly given options without resetting those
348 Allows single options to be modified without disturbing the others:
349 .Bd -literal -offset indent
350 # echo "set loginterface fxp0" | pfctl -mf -
353 Load only the NAT rules present in the rule file.
354 Other rules and options are ignored.
356 Do not actually load rules, just parse them.
358 Load only the options present in the rule file.
359 Other rules and options are ignored.
361 Control the ruleset optimizer, overriding any rule file settings.
363 .Bl -tag -width xxxxxxxxxxxx -compact
365 Disable the ruleset optimizer.
367 Enable basic ruleset optimizations.
368 This is the default behaviour.
370 Enable basic ruleset optimizations with profiling.
372 For further information on the ruleset optimizer, see
375 Do not perform service name lookup for port specific rules,
376 instead display the ports numerically.
380 instead of the default
383 Only print errors and warnings.
385 Load only the filter rules present in the rule file.
386 Other rules and options are ignored.
388 Perform reverse DNS lookups on states when displaying them.
390 Show the filter parameters specified by
392 (may be abbreviated):
394 .Bl -tag -width xxxxxxxxxxxxx -compact
396 Show the currently loaded NAT rules.
398 Show the currently loaded queue rules.
399 When used together with
401 per-queue statistics are also shown.
402 When used together with
405 will loop and show updated queue statistics every five seconds, including
406 measured bandwidth and packets per second.
408 Show the currently loaded filter rules.
409 When used together with
411 the per-rule statistics (number of evaluations,
412 packets and bytes) are also shown.
415 optimization done automatically by the kernel
416 will skip evaluation of rules where possible.
417 Packets passed statefully are counted in the rule that created the state
418 (even though the rule is not evaluated more than once for the entire
421 Show the currently loaded anchors directly attached to the main ruleset.
424 is specified as well, the anchors loaded directly below the given
429 is specified, all anchors attached under the target anchor will be
430 displayed recursively.
432 Show the contents of the state table.
434 Show the contents of the source tracking table.
436 Show filter information (statistics and counters).
437 When used together with
439 source tracking statistics are also shown.
441 Show the running status and provide a non-zero exit status when disabled.
443 Show per-rule statistics (label, evaluations, packets total, bytes total,
444 packets in, bytes in, packets out, bytes out, state creations) of
445 filter rules with labels, useful for accounting.
447 Show the current global timeouts.
449 Show the current pool memory hard limits.
451 Show the list of tables.
453 Show the list of operating system fingerprints.
454 .It Fl s Cm Interfaces
455 Show the list of interfaces and interface drivers available to PF.
456 When used together with
458 it additionally lists which interfaces have skip rules activated.
459 When used together with
461 interface statistics are also shown.
463 can be used to select an interface or a group of interfaces.
465 Show all of the above, except for the lists of interfaces and operating
468 .It Fl T Ar command Op Ar address ...
471 (may be abbreviated) to apply to the table.
474 .Bl -tag -width xxxxxxxxxxxx -compact
478 Flush all addresses of a table.
480 Add one or more addresses in a table.
481 Automatically create a nonexisting table.
483 Delete one or more addresses from a table.
484 .It Fl T Cm expire Ar number
485 Delete addresses which had their statistics cleared more than
488 For entries which have never had their statistics cleared,
490 refers to the time they were added to the table.
492 Replace the addresses of the table.
493 Automatically create a nonexisting table.
495 Show the content (addresses) of a table.
497 Test if the given addresses match a table.
499 Clear all the statistics of a table.
501 Load only the table definitions from
503 This is used in conjunction with the
506 .Bd -literal -offset indent
507 # pfctl -Tl -f pf.conf
517 commands, the list of addresses can be specified either directly on the command
518 line and/or in an unformatted text file, using the
521 Comments starting with a
523 are allowed in the text file.
524 With these commands, the
526 flag can also be used once or twice, in which case
529 detailed result of the operation for each individual address, prefixed by
530 one of the following letters:
532 .Bl -tag -width XXX -compact
534 The address/network has been added.
536 The address/network has been changed (negated).
538 The address/network has been deleted.
546 The address/network is duplicated and therefore ignored.
548 The address/network cannot be added/deleted due to conflicting
552 The address/network has been cleared (statistics).
555 Each table can maintain a set of counters that can be retrieved using the
559 For example, the following commands define a wide open firewall which will keep
560 track of packets going to or coming from the
563 The following commands configure the firewall and send 10 pings to the FTP
565 .Bd -literal -offset indent
566 # printf "table <test> counters { ftp.openbsd.org }\en \e
567 pass out to <test>\en" | pfctl -f-
568 # ping -qc10 ftp.openbsd.org
571 We can now use the table
573 command to output, for each address and packet direction, the number of packets
574 and bytes that are being passed or blocked by rules referencing the table.
575 The time at which the current accounting started is also shown with the
578 .Bd -literal -offset indent
579 # pfctl -t test -vTshow
581 Cleared: Thu Feb 13 18:55:18 2003
582 In/Block: [ Packets: 0 Bytes: 0 ]
583 In/Pass: [ Packets: 10 Bytes: 840 ]
584 Out/Block: [ Packets: 0 Bytes: 0 ]
585 Out/Pass: [ Packets: 10 Bytes: 840 ]
588 Similarly, it is possible to view global information about the tables
591 modifier twice and the
595 This will display the number of addresses on each table,
596 the number of rules which reference the table, and the global
597 packet statistics for the whole table:
598 .Bd -literal -offset indent
602 Cleared: Thu Feb 13 18:55:18 2003
603 References: [ Anchors: 0 Rules: 1 ]
604 Evaluations: [ NoMatch: 3496 Match: 1 ]
605 In/Block: [ Packets: 0 Bytes: 0 ]
606 In/Pass: [ Packets: 10 Bytes: 840 ]
607 In/XPass: [ Packets: 0 Bytes: 0 ]
608 Out/Block: [ Packets: 0 Bytes: 0 ]
609 Out/Pass: [ Packets: 10 Bytes: 840 ]
610 Out/XPass: [ Packets: 0 Bytes: 0 ]
613 As we can see here, only one packet \- the initial ping request \- matched the
614 table, but all packets passing as the result of the state are correctly
616 Reloading the table(s) or ruleset will not affect packet accounting in any way.
619 counters are incremented instead of the
623 packet is passed but does not match the table anymore.
624 This will happen in our example if someone flushes the table while the
628 When used with a single
631 will only display the first line containing the table flags and name.
632 The flags are defined as follows:
634 .Bl -tag -width XXX -compact
636 For constant tables, which cannot be altered outside
639 For persistent tables, which do not get automatically killed when no rules
642 For tables which are part of the
645 Tables without this flag do not really exist, cannot contain addresses, and are
650 For tables which are part of the
653 This flag can only be witnessed briefly during the loading of
656 For tables which are referenced (used) by rules.
658 This flag is set when a table in the main ruleset is hidden by one or more
659 tables of the same name from anchors attached below it.
661 This flag is set when per-address counters are enabled on the table.
664 Specify the name of the table.
666 Produce more verbose output.
669 will produce even more verbose output including ruleset warnings.
670 See the previous section for its effect on table commands.
674 (may be abbreviated) to one of the following:
676 .Bl -tag -width xxxxxxxxxxxx -compact
678 Do not generate debug messages.
680 Generate debug messages only for serious errors.
682 Generate debug messages for various errors.
684 Generate debug messages for common conditions.
687 Clear per-rule statistics.
690 .Bl -tag -width "/etc/pf.conf" -compact
692 Packet filter rules file.
694 Passive operating system fingerprint database.
712 filter mechanism appeared in
714 They first appeared in
716 ported from the version in