xref: /openbsd-src/sbin/pfctl/pfctl.8 (revision e08605c7f2d4f3a5540bdbbdf70eaa19abe1f819)
1.\" $OpenBSD: pfctl.8,v 1.185 2024/11/21 18:16:01 kn Exp $
2.\"
3.\" Copyright (c) 2001 Kjell Wooding.  All rights reserved.
4.\"
5.\" Redistribution and use in source and binary forms, with or without
6.\" modification, are permitted provided that the following conditions
7.\" are met:
8.\" 1. Redistributions of source code must retain the above copyright
9.\"    notice, this list of conditions and the following disclaimer.
10.\" 2. Redistributions in binary form must reproduce the above copyright
11.\"    notice, this list of conditions and the following disclaimer in the
12.\"    documentation and/or other materials provided with the distribution.
13.\" 3. The name of the author may not be used to endorse or promote products
14.\"    derived from this software without specific prior written permission.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26.\"
27.Dd $Mdocdate: November 21 2024 $
28.Dt PFCTL 8
29.Os
30.Sh NAME
31.Nm pfctl
32.Nd control the packet filter (PF) device
33.Sh SYNOPSIS
34.Nm pfctl
35.Bk -words
36.Op Fl deghNnPqrvz
37.Op Fl a Ar anchor
38.Op Fl D Ar macro Ns = Ns Ar value
39.Op Fl F Ar modifier
40.Op Fl f Ar file
41.Op Fl i Ar interface
42.Op Fl K Ar key
43.Op Fl k Ar key
44.Op Fl L Ar statefile
45.Op Fl o Ar level
46.Op Fl p Ar device
47.Op Fl S Ar statefile
48.Op Fl s Ar modifier Op Fl R Ar id
49.Op Fl t Ar table Fl T Ar command Op Ar address ...
50.Op Fl V Ar rdomain
51.Op Fl x Ar level
52.Ek
53.Sh DESCRIPTION
54The
55.Nm
56utility communicates with the packet filter device using the
57ioctl interface described in
58.Xr pf 4 .
59It allows ruleset and parameter configuration,
60and retrieval of status information from the packet filter.
61Packet filtering restricts the types of packets that pass through
62network interfaces entering or leaving the host based on filter
63rules as described in
64.Xr pf.conf 5 .
65The packet filter can also replace addresses and ports of packets.
66.Pp
67The packet filter is enabled by default.
68Should
69.Nm
70be unable to load a ruleset,
71an error occurs and the original ruleset remains in place.
72If this happens at system startup,
73the ruleset defined by the
74.Va RULES
75variable in
76.Xr rc 8
77remains in place.
78.Pp
79The packet filter does not itself forward packets between interfaces.
80Forwarding can be enabled by setting the
81.Xr sysctl 8
82variables
83.Em net.inet.ip.forwarding
84and/or
85.Em net.inet6.ip6.forwarding
86to 1.
87Set them permanently in
88.Xr sysctl.conf 5 .
89.Pp
90At least one option must be specified.
91The options are as follows:
92.Bl -tag -width Ds
93.It Fl a Ar anchor
94Apply flags
95.Fl f ,
96.Fl F ,
97.Fl s ,
98and
99.Fl T
100only to the rules in the specified
101.Ar anchor .
102In addition to the main ruleset,
103.Nm
104can load and manipulate additional rulesets by name,
105called anchors.
106The main ruleset is the default anchor.
107.Pp
108Anchors are referenced by name and may be nested,
109with the various components of the anchor path separated by
110.Sq /
111characters, similar to how file system hierarchies are laid out.
112The last component of the anchor path is where ruleset operations are
113performed.
114.Pp
115Evaluation of
116.Ar anchor
117rules from the main ruleset is described in
118.Xr pf.conf 5 .
119.Pp
120For example, the following will show all filter rules (see the
121.Fl s
122flag below) inside the anchor
123.Dq authpf/smith(1234) ,
124which would have been created for user
125.Dq smith
126by
127.Xr authpf 8 ,
128PID 1234:
129.Bd -literal -offset indent
130# pfctl -a "authpf/smith(1234)" -s rules
131.Ed
132.Pp
133Private tables can also be put inside anchors, either by having table
134statements in the
135.Xr pf.conf 5
136file that is loaded in the anchor, or by using regular table commands, as in:
137.Bd -literal -offset indent
138# pfctl -a foo/bar -t mytable -T add 1.2.3.4 5.6.7.8
139.Ed
140.Pp
141When a rule referring to a table is loaded in an anchor, the rule will use the
142private table if one is defined, and then fall back to the table defined in the
143main ruleset, if there is one.
144This is similar to C rules for variable scope.
145It is possible to create distinct tables with the same name in the global
146ruleset and in an anchor, but this is often bad design and a warning will be
147issued in that case.
148.Pp
149By default, recursive inline printing of anchors applies only to unnamed
150anchors specified inline in the ruleset.
151If the anchor name is terminated with a
152.Sq *
153character, the
154.Fl s
155flag will recursively print all anchors in a brace delimited block.
156For example the following will print the
157.Dq authpf
158ruleset recursively:
159.Bd -literal -offset indent
160# pfctl -a 'authpf/*' -sr
161.Ed
162.Pp
163To print the main ruleset recursively, specify only
164.Sq *
165as the anchor name:
166.Bd -literal -offset indent
167# pfctl -a '*' -sr
168.Ed
169.Pp
170To flush all rulesets and tables recursively, specify only
171.Sq *
172as the anchor name:
173.Bd -literal -offset indent
174# pfctl -a '*' -Fa
175.Ed
176.It Fl D Ar macro Ns = Ns Ar value
177Define
178.Ar macro
179to be set to
180.Ar value
181on the command line.
182Overrides the definition of
183.Ar macro
184in the ruleset.
185.It Fl d
186Disable the packet filter.
187.It Fl e
188Enable the packet filter.
189.It Fl F Ar modifier
190Flush the filter parameters specified by
191.Ar modifier
192(may be abbreviated):
193.Pp
194.Bl -tag -width xxxxxxxxx -compact
195.It Cm rules
196Flush the filter rules.
197.It Cm states
198Flush the state table (NAT and filter).
199.It Cm Sources
200Flush the source tracking table.
201.It Cm info
202Flush the filter information (statistics that are not bound to rules).
203.It Cm Tables
204Flush the tables.
205.It Cm osfp
206Flush the passive operating system fingerprints.
207.It Cm Reset
208Reset limits, timeouts and other options back to default settings.
209See the OPTIONS section in
210.Xr pf.conf 5
211for details.
212.It Cm all
213Flush all of the above.
214.El
215.Pp
216If
217.Fl a
218is specified as well and
219.Ar anchor
220is terminated with a
221.Sq *
222character,
223.Cm rules ,
224.Cm Tables
225and
226.Cm all
227flush the given anchor recursively.
228.It Fl f Ar file
229Replace the current ruleset with
230the rules contained in
231.Ar file .
232This
233.Ar file
234may contain macros, tables, options, and normalization, queueing,
235translation, and filtering rules.
236With the exception of macros and tables, the statements must appear in that
237order.
238.It Fl g
239Include output helpful for debugging.
240.It Fl h
241Help.
242.It Fl i Ar interface
243Restrict the operation to the given
244.Ar interface .
245.It Fl K Ar key
246Kill all of the source tracking entries originating from the
247host or network specified by
248.Ar key .
249A second
250.Fl K
251option may be specified, which will kill all the source tracking entries
252from the first host/network to the second.
253.It Fl k Ar key
254Kill all of the state entries originating from the
255host or network specified by
256.Ar key .
257A second
258.Fl k
259option may be specified, which will kill all the state entries
260from the first host/network to the second.
261.Pp
262A network prefix length of 0 can be used as a wildcard.
263To kill all states with the target
264.Dq host2 :
265.Pp
266.Dl # pfctl -k 0.0.0.0/0 -k host2
267.Pp
268It is also possible to kill states by rule label, state key, or state ID.
269In this mode the first
270.Fl k
271argument is used to specify the type;
272a second
273.Fl k
274gives the actual target.
275.Pp
276To kill states by rule label,
277use the
278.Cm label
279modifier.
280To kill all states created from rules carrying the label
281.Dq foobar :
282.Pp
283.Dl # pfctl -k label -k foobar
284.Pp
285To kill one specific state by its state key
286(as shown by pfctl -s state),
287use the
288.Cm key
289modifier.
290To kill a state originating from 10.0.0.101:32123 to 10.0.0.1:80,
291protocol TCP, use:
292.Pp
293.Dl # pfctl -k key -k 'tcp 10.0.0.1:80 <- 10.0.0.101:32123'
294.Pp
295To kill one specific state by its unique state ID
296(as shown by pfctl -s state -vv),
297use the
298.Cm id
299modifier.
300To kill a state with ID 4823e84500000003 use:
301.Pp
302.Dl # pfctl -k id -k 4823e84500000003
303.Pp
304To kill a state with ID 4823e84500000018 created from a backup
305firewall with hostid 00000002 use:
306.Pp
307.Dl # pfctl -k id -k 4823e84500000018/2
308.It Fl L Ar statefile
309Load pf states from the file specified by
310.Ar statefile .
311.It Fl N
312Do not perform domain name resolution.
313If a name cannot be resolved without DNS, an error will be reported.
314.It Fl n
315Do not actually load rules, just parse them.
316.It Fl o Ar level
317Control the ruleset optimizer, overriding any rule file settings.
318.Pp
319.Bl -tag -width xxxxxxxxx -compact
320.It Cm none
321Disable the ruleset optimizer.
322.It Cm basic
323Enable basic ruleset optimizations.
324This is the default behaviour.
325.It Cm profile
326Enable basic ruleset optimizations with profiling.
327.El
328.Pp
329For further information on the ruleset optimizer, see
330.Xr pf.conf 5 .
331.It Fl P
332Print ports using their names in
333.Pa /etc/services
334if available.
335.It Fl p Ar device
336Use the device file
337.Ar device
338instead of the default
339.Pa /dev/pf .
340.It Fl q
341Only print errors and warnings.
342.It Fl r
343Perform reverse DNS lookups on states and tables when displaying them.
344.Fl N
345and
346.Fl r
347are mutually exclusive.
348.It Fl S Ar statefile
349Store the pf state table in the file specified by
350.Ar statefile .
351.Tg R
352.It Fl s Ar modifier Op Fl R Ar id
353Show the filter parameters specified by
354.Ar modifier
355(may be abbreviated):
356.Pp
357.Bl -tag -width xxxxxxxxxxx -compact
358.It Cm queue
359Show the currently loaded queue definitions.
360When used together with
361.Fl v ,
362per-queue statistics are also shown.
363When used together with
364.Fl v v ,
365.Nm
366will loop and show updated queue statistics every five seconds, including
367measured bandwidth and packets per second.
368.It Cm rules
369Show the currently loaded filter rules.
370If
371.Fl R Ar id
372is specified as well,
373only the rule with the specified numeric ID is shown.
374When used together with
375.Fl v ,
376the per-rule statistics (number of evaluations,
377packets and bytes) are also shown.
378When used together with
379.Fl g
380or
381.Fl vv ,
382expired rules
383.Pq marked as Dq # expired
384are also shown.
385Note that the
386.Dq skip step
387optimization done automatically by the kernel
388will skip evaluation of rules where possible.
389Packets passed statefully are counted in the rule that created the state
390(even though the rule isn't evaluated more than once for the entire
391connection).
392.It Cm Anchors
393Show the currently loaded anchors directly attached to the main ruleset.
394If
395.Fl a Ar anchor
396is specified as well, the anchors loaded directly below the given
397.Ar anchor
398are shown instead.
399If
400.Fl v
401is specified, all anchors attached under the target anchor will be
402displayed recursively.
403.It Cm states
404Show the contents of the state table.
405If
406.Fl R Ar id
407is specified as well,
408only states created by the rule with the specified numeric ID are shown.
409.It Cm Sources
410Show the contents of the source tracking table.
411.It Cm info
412Show filter information (statistics and counters).
413When used together with
414.Fl v ,
415source tracking statistics, the firewall's 32-bit hostid number and the
416main ruleset's MD5 checksum for use with
417.Xr pfsync 4
418are also shown.
419.It Cm labels
420Show per-rule statistics (label, evaluations, packets total, bytes total,
421packets in, bytes in, packets out, bytes out, state creations) of
422filter rules with labels, useful for accounting.
423If
424.Fl R Ar id
425is specified as well,
426only the statistics for the rule with the specified numeric ID are shown.
427.It Cm timeouts
428Show the current global timeouts.
429.It Cm memory
430Show the current pool memory hard limits.
431.It Cm Tables
432Show the list of tables.
433.It Cm osfp
434Show the list of operating system fingerprints.
435.It Cm Interfaces
436Show the list of interfaces and interface groups available to PF.
437When used together with
438.Fl v ,
439it additionally lists which interfaces have skip rules activated.
440When used together with
441.Fl vv ,
442interface statistics are also shown.
443.Fl i
444can be used to select an interface or a group of interfaces.
445.It Cm all
446Show all of the above, except for the lists of interfaces and operating
447system fingerprints.
448.El
449.Pp
450Counters shown with
451.Fl s Cm info
452are:
453.Pp
454.Bl -tag -width xxxxxxxxxxxxxx -compact
455.It match
456explicit rule match
457.It bad-offset
458currently unused
459.It fragment
460invalid fragments dropped
461.It short
462short packets dropped
463.It normalize
464dropped by normalizer: illegal packets
465.It memory
466memory could not be allocated
467.It bad-timestamp
468bad TCP timestamp; RFC 1323
469.It congestion
470network interface queue congested
471.It ip-option
472bad IP/IPv6 options
473.It proto-cksum
474invalid protocol checksum
475.It state-mismatch
476packet was associated with a state entry, but sequence numbers did not match
477.It state-insert
478state insertion failure
479.It state-limit
480configured state limit was reached
481.It src-limit
482source node/connection limit
483.It synproxy
484dropped by synproxy
485.It translate
486no free ports in translation port range
487.It no-route
488dropped by no-route
489.El
490.Tg T
491.It Fl t Ar table Fl T Ar command Op Ar address ...
492Specify the
493.Ar command
494(may be abbreviated) to apply to
495.Ar table .
496Commands include:
497.Pp
498.Bl -tag -width "expire number" -compact
499.It Cm add
500Add one or more addresses to a table.
501Automatically create a persistent table if it does not exist.
502.It Cm delete
503Delete one or more addresses from a table.
504.It Cm expire Ar number
505Delete addresses which had their statistics cleared more than
506.Ar number
507seconds ago.
508For entries which have never had their statistics cleared,
509.Ar number
510refers to the time they were added to the table.
511.It Cm flush
512Flush all addresses in a table.
513.It Cm kill
514Kill a table.
515.It Cm replace
516Replace the addresses of the table.
517Automatically create a persistent table if it does not exist.
518.It Cm show
519Show the content (addresses) of a table.
520.It Cm test
521Test if the given addresses match a table.
522.It Cm zero
523Clear all the statistics of a table, or only for specified addresses.
524.El
525.Pp
526For the
527.Cm add ,
528.Cm delete ,
529.Cm replace ,
530and
531.Cm test
532commands, the list of addresses can be specified either directly on the command
533line and/or in an unformatted text file, using the
534.Fl f
535flag.
536Comments starting with a
537.Sq #
538are allowed in the text file.
539With these commands, the
540.Fl v
541flag can also be used once or twice, in which case
542.Nm
543will print the
544detailed result of the operation for each individual address, prefixed by
545one of the following letters:
546.Pp
547.Bl -tag -width XXX -compact
548.It A
549The address/network has been added.
550.It C
551The address/network has been changed (negated).
552.It D
553The address/network has been deleted.
554.It M
555The address matches
556.Po
557.Cm test
558operation only
559.Pc .
560.It X
561The address/network is duplicated and therefore ignored.
562.It Y
563The address/network cannot be added/deleted due to conflicting
564.Sq \&!
565attributes.
566.It Z
567The address/network has been cleared (statistics).
568.El
569.Pp
570Each table can maintain a set of counters that can be retrieved using the
571.Fl v
572flag of
573.Nm .
574For example, the following commands define a wide open firewall which will keep
575track of packets going to or coming from the
576.Ox
577FTP server.
578The following commands configure the firewall and send 10 pings to the FTP
579server:
580.Bd -literal -offset indent
581# printf "table <test> counters { ftp.openbsd.org }\en \e
582    pass out to <test>\en" | pfctl -f-
583# ping -qc10 ftp.openbsd.org
584.Ed
585.Pp
586We can now use the table
587.Cm show
588command to output, for each address and packet direction, the number of packets
589and bytes that are being passed, matched or blocked by rules referencing the
590table.
591Note that the match counters are incremented for every match rule in which
592they are referenced, meaning that a single packet may be counted multiple times.
593The time at which the current accounting started is also shown with the
594.Dq Cleared
595line.
596.Bd -literal -offset indent
597# pfctl -t test -vTshow
598   198.51.100.81
599        Cleared:        Fri Jun 28 11:17:37 2013
600        In/Block:       [ Packets: 0	Bytes: 0	]
601        In/Match        [ Packets: 54	Bytes: 10028	]
602        In/Pass:        [ Packets: 5	Bytes: 1949	]
603        Out/Block:      [ Packets: 0	Bytes: 0	]
604        Out/Match       [ Packets: 65	Bytes: 12684	]
605        Out/Pass:       [ Packets: 6	Bytes: 389	]
606.Ed
607.Pp
608Similarly, it is possible to view global information about the tables
609by using the
610.Fl v
611modifier twice and the
612.Fl s
613.Cm Tables
614command.
615This will display the number of addresses on each table,
616the number of rules which reference the table, and the global
617packet statistics for the whole table:
618.Bd -literal -offset indent
619# pfctl -vvsTables
620--a-r-C test
621        Addresses:   1
622        Cleared:     Fri Jun 28 11:17:37 2013
623        References:  [ Anchors: 0	Rules: 4	]
624        Evaluations: [ NoMatch: 35	Match: 8	]
625        In/Block:    [ Packets: 0	Bytes: 0	]
626        In/Match:    [ Packets: 54	Bytes: 10028	]
627        In/Pass:     [ Packets: 5	Bytes: 1949	]
628        In/XPass:    [ Packets: 0	Bytes: 0	]
629        Out/Block:   [ Packets: 0	Bytes: 0	]
630        Out/Match:   [ Packets: 65	Bytes: 12684	]
631        Out/Pass:    [ Packets: 6	Bytes: 389	]
632        Out/XPass:   [ Packets: 0	Bytes: 0	]
633.Ed
634.Pp
635Only packets creating state are matched in the Evaluations line,
636but all packets passing as a result of the state are correctly accounted for.
637Reloading the table(s) or ruleset will not affect packet accounting in any way.
638The two
639.Dq XPass
640counters are incremented instead of the
641.Dq Pass
642counters when a
643.Dq stateful
644packet is passed but doesn't match the table anymore.
645This will happen in our example if someone flushes the table while the
646.Xr ping 8
647command is running.
648.Pp
649When used with a single
650.Fl v ,
651.Nm
652will only display the first line containing the table flags and name.
653The flags are defined as follows:
654.Pp
655.Bl -tag -width XXX -compact
656.It c
657For constant tables, which cannot be altered outside
658.Xr pf.conf 5 .
659.It p
660For persistent tables, which don't get automatically killed when no rules
661refer to them.
662.It a
663For tables which are part of the
664.Em active
665tableset.
666Tables without this flag do not really exist, cannot contain addresses, and are
667only listed if the
668.Fl g
669flag is given.
670.It i
671For tables which are part of the
672.Em inactive
673tableset.
674This flag can only be witnessed briefly during the loading of
675.Xr pf.conf 5 .
676.It r
677For tables which are referenced (used) by rules.
678.It h
679This flag is set when a table in the main ruleset is hidden by one or more
680tables of the same name from anchors attached below it.
681.It C
682This flag is set when per-address counters are enabled on the table.
683.El
684.It Fl V Ar rdomain
685Select the routing domain to be used to kill states by host or by label.
686The rdomain of a state is displayed in parentheses before the host by
687.Fl s Cm states .
688.It Fl v
689Produce more verbose output.
690A second use of
691.Fl v
692will produce even more verbose output including ruleset warnings.
693See the previous section for its effect on table commands.
694.It Fl x Ar level
695Set the debug
696.Ar level ,
697which limits the severity of log messages printed by
698.Xr pf 4 .
699This should be a keyword from the following ordered list
700(highest to lowest):
701.Cm emerg ,
702.Cm alert ,
703.Cm crit ,
704.Cm err ,
705.Cm warning ,
706.Cm notice ,
707.Cm info ,
708and
709.Cm debug .
710These keywords correspond to the similar (LOG_) values specified to the
711.Xr syslog 3
712library routine,
713and may be abbreviated on the command line.
714.It Fl z
715Clear per-rule statistics.
716.El
717.Sh FILES
718.Bl -tag -width "/etc/pf.conf" -compact
719.It Pa /etc/pf.conf
720Packet filter rules file.
721.It Pa /etc/pf.os
722Passive operating system fingerprint database.
723.El
724.Sh SEE ALSO
725.Xr pf 4 ,
726.Xr pf.conf 5 ,
727.Xr pf.os 5 ,
728.Xr sysctl.conf 5 ,
729.Xr authpf 8 ,
730.Xr ftp-proxy 8 ,
731.Xr rc 8 ,
732.Xr rc.conf 8 ,
733.Xr sysctl 8
734.Sh HISTORY
735The
736.Nm
737program and the
738.Xr pf 4
739filter mechanism first appeared in
740.Ox 3.0 .
741