summaryrefslogtreecommitdiff
path: root/sbin/pfctl/pfctl.8
blob: 2e055e5df61d8f3dea03c49883703130035b89c6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
.\" $OpenBSD: pfctl.8,v 1.77 2003/02/14 12:04:23 henning Exp $
.\"
.\" Copyright (c) 2001 Kjell Wooding.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd Nov 20, 2002
.Dt PFCTL 8
.Os
.Sh NAME
.Nm pfctl
.Nd control the packet filter (PF) and network address translation (NAT) device
.Sh SYNOPSIS
.Nm pfctl
.Bk -words
.Op Fl AdehnNqrRvzO
.Op Fl a Ar anchor[:ruleset]
.Op Fl D Ar macro=value
.Op Fl F Ar modifier
.Op Fl f Ar file
.Op Fl k Ar host
.Op Fl s Ar modifier
.Op Fl x Ar level
.Op Fl t Ar table
.Op Fl T Ar command
.Ek
.Sh DESCRIPTION
The
.Nm
utility communicates with the packet filter device using the
ioctl interface described in
.Xr pf 4 .
It allows ruleset and parameter configuration and retrieval of status
information from the packet filter.
.Pp
Packet filtering restricts the types of packets that pass through
network interfaces entering or leaving the host based on filter
rules as described in
.Xr 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 making all connections to external hosts appear to
come from the gateway.
Replacing destination 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
supported.
Translation rules are described in
.Xr pf.conf 5 .
.Pp
When the variable pf is set to YES in
.Xr rc.conf 8 ,
the rule file specified with the variable pf_rules
is loaded automatically by the
.Xr rc 8
scripts and the packet filter is enabled.
.Pp
The packet filter does not itself forward packets between interfaces.
Forwarding can be enabled by setting the
.Xr sysctl 8
variables
.Em net.inet.ip.forwarding
and/or
.Em net.inet6.ip6.forwarding ,
to 1.
Set them permanently in
.Xr sysctl.conf 5 .
.Pp
The
.Nm
utility provides several commands.
The options are as follows:
.Bl -tag -width Ds
.It Fl a Ar anchor Ns Op Ar :ruleset
Apply flags
.Fl f ,
.Fl F
and
.Fl s
only to the rules in the specified
.Pa anchor
and optional named ruleset
.Ar ruleset .
In addition to the main ruleset,
.Nm
can load and manipulate additional rulesets by name.
Named rulesets are attached at
.Pa anchor
points, which are also referenced by name.
Evaluation of
.Pa anchor
rules from the main ruleset is described in
.Xr pf.conf 5 .
.Bd -literal -offset indent
Example:
Show all filter rules inside anchor foo
.Ic # pfctl -a foo -s rules
.Ed
.It Fl A
Load only the queue rules present in the rule file.
Other rules and options are ignored.
.It Fl d
Disable the packet filter.
.It Fl D Ar macro=value
Define macros on the command line.
Overrides macro definition in the ruleset.
.It Fl e
Enable the packet filter.
.It Fl f Ar file
Load rule 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.
.It Fl F Ar modifier
Flush one of the following.
Modifier name may be abbreviated:
.Bl -tag -width "F tables " -compact
.It Fl F Ar nat
Flush the NAT rules.
.It Fl F Ar queue
Flush the queue rules.
.It Fl F Ar rules
Flush the filter rules.
.It Fl F Ar state
Flush the state table (NAT and filter).
.It Fl F Ar info
Flush the filter information (statistics that are not bound to rules).
.It Fl F Ar Tables
Flush the tables.
.It Fl F Ar all
Flush all of the above.
.El
.It Fl k Ar host
Kill all of the state entries from the specified host.
A second
.Fl k Ar host
option may be specified, which will kill all the state entries
from the first host to the second host.
.Bd -literal -offset indent
Example:
Kill all of the state entries from host
.Ic # pfctl -k host
.Pp
Kill all of the state entries from host1 to host2
.Ic # pfctl -k host1 -k host2
.Ed
.It Fl h
Help.
.It Fl n
Do not actually load rules, just parse them.
.It Fl N
Load only the NAT rules present in the rule file.
Other rules and options are ignored.
.It Fl q
Only print errors and warnings.
.It Fl r
Perform reverse DNS lookups on states when displaying them.
.It Fl R
Load only the filter rules present in the rule file.
Other rules and options are ignored.
.It Fl O
Load only the options present in the rule file.
Other rules and options are ignored.
.It Fl s Ar modifier
Show filter parameters.
Modifier names may be abbreviated:
.Bl -tag -width "s timeouts " -compact
.It Fl s Ar nat
Show the currently loaded NAT rules.
.It Fl s Ar queue
Show the currently loaded queue rules.
When used together with
.Fl v ,
per-queue statistics are also shown.
When used together with
.Fl v v ,
.Nm
will loop and show updated queue statistics every five seconds, including
measured bandwidth and packets per second.
.It Fl s Ar 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 automatically 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).
.It Fl s Ar Anchors
Show the currently loaded anchors.
If
.Fl a Ar anchor
is specified as well, the named rulesets currently loaded in the specified
anchor are shown instead.
.It Fl s Ar state
Show the contents of the state table.
.It Fl s Ar info
Show filter information (statistics and counters).
.It Fl s Ar labels
Show per-rule statistics (in terse format) of filter rules with labels,
useful for accounting.
.It Fl s Ar timeouts
Show the current global timeouts.
.It Fl s Ar memory
Show the current pool memory hard limits.
.It Fl s Ar Tables
Show the list of tables.
.It Fl s Ar all
Show all of the above.
.El
.It Fl t Ar table
Specify the name of the table.
.It Fl T Ar command
Specify the command to apply to the table.
commands include:
.Bl -tag -width "T Replace " -compact
.It Fl T Ar create
Create a new table.
.It Fl T Ar kill
Kill a table.
.It Fl T Ar flush
Flush all addresses of a table.
.It Fl T Ar add
Add one or more addresses in a table.
Automatically create a nonexisting table.
.It Fl T Ar delete
Delete one or more addresses from a table.
.It Fl T Ar replace
Replace the addresses of the table.
Automatically create a nonexisting table.
.It Fl T Ar show
Show the content (addresses) of a table.
.It Fl T Ar test
Test if the given addresses match a table.
.It Fl T Ar zero
Clear all the statistics of a table.
.It Fl T Ar load
Load only the table definitions from pf.conf.
Used in conjunction with the
.Fl f
flag, like in: "pfctl -Tl -f pf.conf".
.El
.Pp
For the
.Ar add ,
.Ar delete ,
.Ar replace
and
.Ar test
commands, the list of addresses can be specified either directly on the command
line and/or in an unformatted text file, using the
.Fl f
flag.
#-starting comments are allowed in the text file.
With these commands, the
.Fl v
flag can also be used once or twice, in which case
.Nm pfctl
will print the
detailed result of the operation for each individual address, prefixed by
one of the following letters:
.Pp
.Bl -tag -width XXX -compact
.It A
The address/network has been added.
.It C
The address/network has been changed (negated).
.It D
The address/network has been deleted.
.It M
The address match (test operation only).
.It X
The address/network is duplicated and therefore ignored.
.It Y
The address/network cannot be added/deleted due to conflicting "!" attribute.
.It Z
The address/network has been cleared (statistics).
.El
.Pp
Each table maintains a set of counters that can be retrieved using the
.Fl v
flag of
.Nm pfctl .
For example, the following command define a wide open firewall which will keep
track of packets going to or coming from OpenBSD ftp server.
The following commands configure the firewall and send 10 pings to the ftp
server:
.Pp
.Bd -literal -offset indent
.Ic # echo \&"table <test> { ftp.openbsd.org }\en\&"\e
.Ic > \&"pass out to <test> keep state\&" Xo
.Ic \&| pfctl -f-
.Xc
.Ic # ping -qc10 ftp.openbsd.org
.Ed
.Pp
We can now use the table
.Ar show
command to output, for each address and packet direction, the number of packets
and bytes that are being passed or blocked by rules referencing the table.
The time at which the current accounting started is also shown with the
.Ar Cleared
line.
.Pp
.Bd -literal -offset indent
.Ic # pfctl -t test -vTshow
.Ic \ \ 129.128.5.191
.Ic \ \ \ \ Cleared: \ \ \ \ Thu Feb 13 18:55:18 2003
.Ic \ \ \ \ In/Block: \ \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ]
.Ic \ \ \ \ In/Pass: \ \ \ \ [ Packets: 10 \ \ \ \ \ \ Bytes: 840 \ \ \ \ \ ]
.Ic \ \ \ \ Out/Block: \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ]
.Ic \ \ \ \ Out/Pass: \ \ \ [ Packets: 10 \ \ \ \ \ \ Bytes: 840 \ \ \ \ \ ]
.Ed
.Pp
Similarly, It is possible to view global information about the tables
by using two times the
.Fl v
modifier and the
.Ar show 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:
.Pp
.Bd -literal -offset indent
.Ic # pfctl -vvsTables
.Ic --a-r   test
.Ic \ \ \ \ Addresses: \ \ 1
.Ic \ \ \ \ References: \ 1
.Ic \ \ \ \ Cleared: \ \ \ \ Thu Feb 13 18:55:18 2003
.Ic \ \ \ \ Evaluations: [\ NoMatch: 3496 \ \ \ \ Match: 1 \ \ \ \ \ \ \ ]
.Ic \ \ \ \ In/Block: \ \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ]
.Ic \ \ \ \ In/Pass: \ \ \ \ [ Packets: 10 \ \ \ \ \ \ Bytes: 840 \ \ \ \ \ ]
.Ic \ \ \ \ In/XPass: \ \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ]
.Ic \ \ \ \ Out/Block: \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ]
.Ic \ \ \ \ Out/Pass: \ \ \ [ Packets: 10 \ \ \ \ \ \ Bytes: 840 \ \ \ \ \ ]
.Ic \ \ \ \ Out/XPass: \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ]
.Ed
.Pp
As we can see here, only one packet - the initial ping request - matched the
table; but all packets passing at the result of the state are correctly
accounted for.
Reloading the table(s) will not affect packet accounting in any way; however,
the state accounting will stop if the rules are reloaded or flushed.
The two
.Ar XPass
counters are incremented instead of the
.Ar 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
command is running.
.Pp
When used with a single
.Fl v ,
.Nm pfctl
will only display the first line containing the table flags and name.
The flags are defined as follows:
.Pp
.Bl -tag -width XXX -compact
.It c
For constant tables, which cannot be altered outside
.Nm pf.conf .
.It p
For persistant tables, which don't get automatically flushed when no rules
refers to them.
.It a
For tables which are part of the
.Ar active
tableset.
Tables without this flag do not really exist, cannot contain addresses, and are
not listed if no
.Fl v
flag is given.
.It i
For tables which are part of the
.Ar inactive
tableset.
This flag can only be witnessed briefly during the loading of
.Nm pf.conf .
.It r
For tables which are referenced (used) by rules.
.El
.It Fl v
Produce more verbose output.
A second use of
.Fl v
will produce even more verbose output.
See previous section for its effect on table commands.
.It Fl x Ar level
Set the debug level to one of the following.
Level names may be abbreviated:
.Bl -tag -width "x urgent " -compact
.It Fl x Ar none
Don't generate debug messages.
.It Fl x Ar urgent
Generate debug messages only for serious errors.
.It Fl x Ar misc
Generate debug messages for various errors.
.El
.It Fl z
Clear per-rule statistics.
.El
.Sh FILES
.Bl -tag -width "/etc/pf.conf" -compact
.It Pa /etc/pf.conf
Packet filter rules file.
.El
.Sh SEE ALSO
.Xr pf 4 ,
.Xr pf.conf 5 ,
.Xr sysctl.conf 5 ,
.Xr ftp-proxy 8 ,
.Xr rc 8 ,
.Xr rc.conf 8 ,
.Xr sysctl 8
.Sh HISTORY
The
.Nm
program and the
.Xr pf 4
filter mechanism first appeared in
.Ox 3.0 .