1 .\" $OpenBSD: pfctl.8,v 1.128 2007/01/30 21:01:56 jmc Exp $
3 .\" Copyright (c) 2001 Kjell Wooding. All rights reserved.
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34 .Nd "control the packet filter (PF) and network address translation (NAT) device"
38 .Op Fl AdeghmNnOPqRrvz
40 .Oo Fl D Ar macro Ns =
45 .Op Fl K Ar host | network
46 .Op Fl k Ar host | network
60 utility communicates with the packet filter device using the
61 ioctl interface described in
63 It allows ruleset and parameter configuration and retrieval of status
64 information from the packet filter.
66 Packet filtering restricts the types of packets that pass through
67 network interfaces entering or leaving the host based on filter
70 The packet filter can also replace addresses and ports of packets.
71 Replacing source addresses and ports of outgoing packets is called
72 NAT (Network Address Translation) and is used to connect an internal
73 network (usually reserved address space) to an external one (the
74 Internet) by making all connections to external hosts appear to
75 come from the gateway.
76 Replacing destination addresses and ports of incoming packets
77 is used to redirect connections to different hosts and/or ports.
78 A combination of both translations, bidirectional NAT, is also
80 Translation rules are described in
89 the rule file specified with the variable
91 is loaded automatically by the
93 scripts and the packet filter is enabled.
95 The packet filter does not itself forward packets between interfaces.
96 Forwarding can be enabled by setting the
99 .Em net.inet.ip.forwarding
101 .Em net.inet6.ip6.forwarding
103 Set them permanently in
108 utility provides several commands.
109 The options are as follows:
112 Load only the queue rules present in the rule file.
113 Other rules and options are ignored.
120 only to the rules in the specified
122 In addition to the main ruleset,
124 can load and manipulate additional rulesets by name,
126 The main ruleset is the default anchor.
128 Anchors are referenced by name and may be nested,
129 with the various components of the anchor path separated by
131 characters, similar to how file system hierarchies are laid out.
132 The last component of the anchor path is where ruleset operations are
137 rules from the main ruleset is described in
140 For example, the following will show all filter rules (see the
142 flag below) inside the anchor
143 .Dq authpf/smith(1234) ,
144 which would have been created for user
149 .Bd -literal -offset indent
150 # pfctl -a "authpf/smith(1234)" -s rules
153 Private tables can also be put inside anchors, either by having table
156 file that is loaded in the anchor, or by using regular table commands, as in:
157 .Bd -literal -offset indent
158 # pfctl -a foo/bar -t mytable -T add 1.2.3.4 5.6.7.8
161 When a rule referring to a table is loaded in an anchor, the rule will use the
162 private table if one is defined, and then fall back to the table defined in the
163 main ruleset, if there is one.
164 This is similar to C rules for variable scope.
165 It is possible to create distinct tables with the same name in the global
166 ruleset and in an anchor, but this is often bad design and a warning will be
169 By default, recursive inline printing of anchors applies only to unnamed
170 anchors specified inline in the ruleset.
171 If the anchor name is terminated with a
175 flag will recursively print all anchors in a brace delimited block.
176 For example the following will print the
179 .Bd -literal -offset indent
180 # pfctl -a 'authpf/*' -sr
183 To print the main ruleset recursively, specify only
186 .Bd -literal -offset indent
189 .It Fl D Ar macro Ns = Ns Ar value
195 Overrides the definition of
199 Disable the packet filter.
201 Enable the packet filter.
203 Flush the filter parameters specified by
205 (may be abbreviated):
207 .Bl -tag -width xxxxxxxxxxxx -compact
211 Flush the queue rules.
213 Flush the filter rules.
215 Flush the state table (NAT and filter).
217 Flush the source tracking table.
219 Flush the filter information (statistics that are not bound to rules).
223 Flush the passive operating system fingerprints.
225 Flush all of the above.
228 Load the rules contained in
232 may contain macros, tables, options, and normalization, queueing,
233 translation, and filtering rules.
234 With the exception of macros and tables, the statements must appear in that
237 Include output helpful for debugging.
240 .It Fl i Ar interface
241 Restrict the operation to the given
243 .It Fl K Ar host | network
244 Kill all of the source tracking entries originating from the specified
252 option may be specified, which will kill all the source tracking
253 entries from the first host/network to the second.
254 .It Fl k Ar host | network
255 Kill all of the state entries originating from the specified
263 option may be specified, which will kill all the state entries
264 from the first host/network to the second.
265 For example, to kill all of the state entries originating from
270 To kill all of the state entries from
275 .Dl # pfctl -k host1 -k host2
277 To kill all states originating from 192.168.1.0/24 to 172.16.0.0/16:
279 .Dl # pfctl -k 192.168.1.0/24 -k 172.16.0.0/16
281 A network prefix length of 0 can be used as a wildcard.
282 To kill all states with the target
285 .Dl # pfctl -k 0.0.0.0/0 -k host2
287 Merge in explicitly given options without resetting those
289 Allows single options to be modified without disturbing the others:
290 .Bd -literal -offset indent
291 # echo "set loginterface fxp0" | pfctl -mf -
294 Load only the NAT rules present in the rule file.
295 Other rules and options are ignored.
297 Do not actually load rules, just parse them.
299 Load only the options present in the rule file.
300 Other rules and options are ignored.
302 Control the ruleset optimizer.
303 The ruleset optimizer attempts to improve rulesets by removing rule
304 duplication and making better use of rule ordering.
306 .Bl -tag -width xxxxxxxxxxxx -compact
308 Disable the ruleset optimizer.
310 Enable basic ruleset optimizations.
312 Enable basic ruleset optimizations with profiling.
316 optimization does does four things:
320 remove duplicate rules
322 remove rules that are a subset of another rule
324 combine multiple rules into a table when advantageous
326 re-order the rules to improve evaluation performance
331 is specified, the currently loaded ruleset will be examined as a feedback
332 profile to tailor the optimization of the
334 rules to the actual network behavior.
336 It is important to note that the ruleset optimizer will modify the ruleset
337 to improve performance.
338 A side effect of the ruleset modification is that per-rule accounting
339 statistics will have different meanings than before.
340 If per-rule accounting is important for billing purposes or whatnot, either
341 the ruleset optimizer should not be used or a
343 field should be added to all of the accounting rules to act as optimization
346 To retain compatibility with previous behaviour, a single
348 without any options will enable
350 optimizations, and a second
352 will enable profiling.
354 Do not perform service name lookup for port specific rules,
355 instead display the ports numerically.
359 instead of the default
362 Only print errors and warnings.
364 Load only the filter rules present in the rule file.
365 Other rules and options are ignored.
367 Perform reverse DNS lookups on states when displaying them.
369 Show the filter parameters specified by
371 (may be abbreviated):
373 .Bl -tag -width xxxxxxxxxxxxx -compact
375 Show the currently loaded NAT rules.
377 Show the currently loaded queue rules.
378 When used together with
380 per-queue statistics are also shown.
381 When used together with
384 will loop and show updated queue statistics every five seconds, including
385 measured bandwidth and packets per second.
387 Show the currently loaded filter rules.
388 When used together with
390 the per-rule statistics (number of evaluations,
391 packets and bytes) are also shown.
394 optimization done automatically by the kernel
395 will skip evaluation of rules where possible.
396 Packets passed statefully are counted in the rule that created the state
397 (even though the rule isn't evaluated more than once for the entire
400 Show the currently loaded anchors directly attached to the main ruleset.
403 is specified as well, the anchors loaded directly below the given
408 is specified, all anchors attached under the target anchor will be
409 displayed recursively.
411 Show the contents of the state table.
413 Show the contents of the source tracking table.
415 Show filter information (statistics and counters).
416 When used together with
418 source tracking statistics are also shown.
420 Show per-rule statistics (label, evaluations, packets total, bytes total,
421 packets in, bytes in, packets out, bytes out) of
422 filter rules with labels, useful for accounting.
424 Show the current global timeouts.
426 Show the current pool memory hard limits.
428 Show the list of tables.
430 Show the list of operating system fingerprints.
431 .It Fl s Cm Interfaces
432 Show the list of interfaces and interface drivers available to PF.
433 When used together with
435 it additionally lists which interfaces have skip rules activated.
436 When used together with
438 interface statistics are also shown.
440 can be used to select an interface or a group of interfaces.
442 Show all of the above, except for the lists of interfaces and operating
445 .It Fl T Ar command Op Ar address ...
448 (may be abbreviated) to apply to the table.
451 .Bl -tag -width xxxxxxxxxxxx -compact
455 Flush all addresses of a table.
457 Add one or more addresses in a table.
458 Automatically create a nonexisting table.
460 Delete one or more addresses from a table.
461 .It Fl T Cm expire Ar number
462 Delete addresses which had their statistics cleared more than
465 For entries which have never had their statistics cleared,
467 refers to the time they were added to the table.
469 Replace the addresses of the table.
470 Automatically create a nonexisting table.
472 Show the content (addresses) of a table.
474 Test if the given addresses match a table.
476 Clear all the statistics of a table.
478 Load only the table definitions from
480 This is used in conjunction with the
483 .Bd -literal -offset indent
484 # pfctl -Tl -f pf.conf
494 commands, the list of addresses can be specified either directly on the command
495 line and/or in an unformatted text file, using the
498 Comments starting with a
500 are allowed in the text file.
501 With these commands, the
503 flag can also be used once or twice, in which case
506 detailed result of the operation for each individual address, prefixed by
507 one of the following letters:
509 .Bl -tag -width XXX -compact
511 The address/network has been added.
513 The address/network has been changed (negated).
515 The address/network has been deleted.
523 The address/network is duplicated and therefore ignored.
525 The address/network cannot be added/deleted due to conflicting
529 The address/network has been cleared (statistics).
532 Each table maintains a set of counters that can be retrieved using the
536 For example, the following commands define a wide open firewall which will keep
537 track of packets going to or coming from the
540 The following commands configure the firewall and send 10 pings to the FTP
542 .Bd -literal -offset indent
543 # printf "table <test> { ftp.openbsd.org }\en \e
544 pass out to <test>\en" | pfctl -f-
545 # ping -qc10 ftp.openbsd.org
548 We can now use the table
550 command to output, for each address and packet direction, the number of packets
551 and bytes that are being passed or blocked by rules referencing the table.
552 The time at which the current accounting started is also shown with the
555 .Bd -literal -offset indent
556 # pfctl -t test -vTshow
558 Cleared: Thu Feb 13 18:55:18 2003
559 In/Block: [ Packets: 0 Bytes: 0 ]
560 In/Pass: [ Packets: 10 Bytes: 840 ]
561 Out/Block: [ Packets: 0 Bytes: 0 ]
562 Out/Pass: [ Packets: 10 Bytes: 840 ]
565 Similarly, it is possible to view global information about the tables
568 modifier twice and the
572 This will display the number of addresses on each table,
573 the number of rules which reference the table, and the global
574 packet statistics for the whole table:
575 .Bd -literal -offset indent
579 Cleared: Thu Feb 13 18:55:18 2003
580 References: [ Anchors: 0 Rules: 1 ]
581 Evaluations: [ NoMatch: 3496 Match: 1 ]
582 In/Block: [ Packets: 0 Bytes: 0 ]
583 In/Pass: [ Packets: 10 Bytes: 840 ]
584 In/XPass: [ Packets: 0 Bytes: 0 ]
585 Out/Block: [ Packets: 0 Bytes: 0 ]
586 Out/Pass: [ Packets: 10 Bytes: 840 ]
587 Out/XPass: [ Packets: 0 Bytes: 0 ]
590 As we can see here, only one packet \- the initial ping request \- matched the
591 table, but all packets passing as the result of the state are correctly
593 Reloading the table(s) or ruleset will not affect packet accounting in any way.
596 counters are incremented instead of the
600 packet is passed but doesn't match the table anymore.
601 This will happen in our example if someone flushes the table while the
605 When used with a single
608 will only display the first line containing the table flags and name.
609 The flags are defined as follows:
611 .Bl -tag -width XXX -compact
613 For constant tables, which cannot be altered outside
616 For persistent tables, which don't get automatically killed when no rules
619 For tables which are part of the
622 Tables without this flag do not really exist, cannot contain addresses, and are
627 For tables which are part of the
630 This flag can only be witnessed briefly during the loading of
633 For tables which are referenced (used) by rules.
635 This flag is set when a table in the main ruleset is hidden by one or more
636 tables of the same name from anchors attached below it.
639 Specify the name of the table.
641 Produce more verbose output.
644 will produce even more verbose output including ruleset warnings.
645 See the previous section for its effect on table commands.
649 (may be abbreviated) to one of the following:
651 .Bl -tag -width xxxxxxxxxxxx -compact
653 Don't generate debug messages.
655 Generate debug messages only for serious errors.
657 Generate debug messages for various errors.
659 Generate debug messages for common conditions.
662 Clear per-rule statistics.
665 .Bl -tag -width "/etc/pf.conf" -compact
667 Packet filter rules file.
669 Passive operating system fingerprint database.
687 filter mechanism first appeared in