path: root/sbin/pfctl/pfctl.8

.\" $OpenBSD: pfctl.8,v 1.176 2019/01/29 08:56:22 kn 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 $Mdocdate: January 29 2019 $
.Dt PFCTL 8
.Os
.Sh NAME
.Nm pfctl
.Nd control the packet filter (PF) device
.Sh SYNOPSIS
.Nm pfctl
.Bk -words
.Op Fl deghNnPqrvz
.Op Fl a Ar anchor
.Op Fl D Ar macro Ns = Ns Ar value
.Op Fl F Ar modifier
.Op Fl f Ar file
.Op Fl i Ar interface
.Op Fl K Ar key
.Op Fl k Ar key
.Op Fl L Ar statefile
.Op Fl o Ar level
.Op Fl p Ar device
.Op Fl S Ar statefile
.Op Fl s Ar modifier Op Fl R Ar id
.Op Fl t Ar table Fl T Ar command Op Ar address ...
.Op Fl V Ar rdomain
.Op Fl x Ar level
.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.
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.
.Pp
The packet filter is enabled by default.
Should
.Nm
be unable to load a ruleset,
an error occurs and the original ruleset remains in place.
If this happens at system startup,
the ruleset defined by the
.Va RULES
variable in
.Xr rc 8
remains in place.
.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
At least one option must be specified.
The options are as follows:
.Bl -tag -width Ds
.It Fl a Ar anchor
Apply flags
.Fl f ,
.Fl F ,
.Fl s ,
and
.Fl T
only to the rules in the specified
.Ar anchor .
In addition to the main ruleset,
.Nm
can load and manipulate additional rulesets by name,
called anchors.
The main ruleset is the default anchor.
.Pp
Anchors are referenced by name and may be nested,
with the various components of the anchor path separated by
.Sq /
characters, similar to how file system hierarchies are laid out.
The last component of the anchor path is where ruleset operations are
performed.
.Pp
Evaluation of
.Ar anchor
rules from the main ruleset is described in
.Xr pf.conf 5 .
.Pp
For example, the following will show all filter rules (see the
.Fl s
flag below) inside the anchor
.Dq authpf/smith(1234) ,
which would have been created for user
.Dq smith
by
.Xr authpf 8 ,
PID 1234:
.Bd -literal -offset indent
# pfctl -a "authpf/smith(1234)" -s rules
.Ed
.Pp
Private tables can also be put inside anchors, either by having table
statements in the
.Xr pf.conf 5
file that is loaded in the anchor, or by using regular table commands, as in:
.Bd -literal -offset indent
# pfctl -a foo/bar -t mytable -T add 1.2.3.4 5.6.7.8
.Ed
.Pp
When a rule referring to a table is loaded in an anchor, the rule will use the
private 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.
.Pp
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
.Sq *
character, the
.Fl s
flag will recursively print all anchors in a brace delimited block.
For example the following will print the
.Dq authpf
ruleset recursively:
.Bd -literal -offset indent
# pfctl -a 'authpf/*' -sr
.Ed
.Pp
To print the main ruleset recursively, specify only
.Sq *
as the anchor name:
.Bd -literal -offset indent
# pfctl -a '*' -sr
.Ed
.It Fl D Ar macro Ns = Ns Ar value
Define
.Ar macro
to be set to
.Ar value
on the command line.
Overrides the definition of
.Ar macro
in the ruleset.
.It Fl d
Disable the packet filter.
.It Fl e
Enable the packet filter.
.It Fl F Ar modifier
Flush the filter parameters specified by
.Ar modifier
(may be abbreviated):
.Pp
.Bl -tag -width xxxxxxxxxxxx -compact
.It Fl F Cm rules
Flush the filter rules.
.It Fl F Cm states
Flush the state table (NAT and filter).
.It Fl F Cm Sources
Flush the source tracking table.
.It Fl F Cm info
Flush the filter information (statistics that are not bound to rules).
.It Fl F Cm Tables
Flush the tables.
.It Fl F Cm osfp
Flush the passive operating system fingerprints.
.It Fl F Cm all
Flush all of the above.
.El
.It Fl f Ar file
Replace the current ruleset with
the rules contained in
.Ar file .
This
.Ar 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 g
Include output helpful for debugging.
.It Fl h
Help.
.It Fl i Ar interface
Restrict the operation to the given
.Ar interface .
.It Fl K Ar key
Kill all of the source tracking entries originating from the
host or network specified by
.Ar key .
A second
.Fl K
option may be specified, which will kill all the source tracking entries
from the first host/network to the second.
.It Fl k Ar key
Kill all of the state entries originating from the
host or network specified by
.Ar key .
A second
.Fl k
option may be specified, which will kill all the state entries
from the first host/network to the second.
.Pp
A network prefix length of 0 can be used as a wildcard.
To kill all states with the target
.Dq host2 :
.Pp
.Dl # pfctl -k 0.0.0.0/0 -k host2
.Pp
It is also possible to kill states by rule label, state key, or state ID.
In this mode the first
.Fl k
argument is used to specify the type;
a second
.Fl k
gives the actual target.
.Pp
To kill states by rule label,
use the
.Cm label
modifier.
To kill all states created from rules carrying the label
.Dq foobar :
.Pp
.Dl # pfctl -k label -k foobar
.Pp
To kill one specific state by its state key
(as shown by pfctl -s state),
use the
.Cm key
modifier.
To kill a state originating from 10.0.0.101:32123 to 10.0.0.1:80,
protocol TCP, use:
.Pp
.Dl # pfctl -k key -k 'tcp 10.0.0.1:80 <- 10.0.0.101:32123'
.Pp
To kill one specific state by its unique state ID
(as shown by pfctl -s state -vv),
use the
.Cm id
modifier.
To kill a state with ID 4823e84500000003 use:
.Pp
.Dl # pfctl -k id -k 4823e84500000003
.Pp
To kill a state with ID 4823e84500000018 created from a backup
firewall with hostid 00000002 use:
.Pp
.Dl # pfctl -k id -k 4823e84500000018/2
.It Fl L Ar statefile
Load pf states from the file specified by
.Ar statefile .
.It Fl N
Do not perform domain name resolution.
If a name cannot be resolved without DNS, an error will be reported.
.It Fl n
Do not actually load rules, just parse them.
.It Fl o Ar level
Control the ruleset optimizer, overriding any rule file settings.
.Pp
.Bl -tag -width xxxxxxxxxxxx -compact
.It Fl o Cm none
Disable the ruleset optimizer.
.It Fl o Cm basic
Enable basic ruleset optimizations.
This is the default behaviour.
.It Fl o Cm profile
Enable basic ruleset optimizations with profiling.
.El
For further information on the ruleset optimizer, see
.Xr pf.conf 5 .
.It Fl P
Print ports using their names in
.Pa /etc/services
if available.
.It Fl p Ar device
Use the device file
.Ar device
instead of the default
.Pa /dev/pf .
.It Fl q
Only print errors and warnings.
.It Fl r
Perform reverse DNS lookups on states and tables when displaying them.
.Fl N
and
.Fl r
are mutually exclusive.
.It Fl S Ar statefile
Store the pf state table in the file specified by
.Ar statefile .
.It Fl s Ar modifier
Show the filter parameters specified by
.Ar modifier
(may be abbreviated):
.Pp
.Bl -tag -width xxxxxxxxxxxxxx -compact
.It Fl s Cm queue
Show the currently loaded queue definitions.
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 Cm rules
Show the currently loaded filter rules.
If
.Fl R Ar id
is specified as well,
only the rule with the specified numeric ID is shown.
When used together with
.Fl v ,
the per-rule statistics (number of evaluations,
packets and bytes) are also shown.
Note that the
.Dq 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 Cm Anchors
Show the currently loaded anchors directly attached to the main ruleset.
If
.Fl a Ar anchor
is specified as well, the anchors loaded directly below the given
.Ar anchor
are shown instead.
If
.Fl v
is specified, all anchors attached under the target anchor will be
displayed recursively.
.It Fl s Cm states
Show the contents of the state table.
If
.Fl R Ar id
is specified as well,
only states created by the rule with the specified numeric ID are shown.
.It Fl s Cm Sources
Show the contents of the source tracking table.
.It Fl s Cm info
Show filter information (statistics and counters).
When used together with
.Fl v ,
source tracking statistics are also shown.
.It Fl s Cm labels
Show per-rule statistics (label, evaluations, packets total, bytes total,
packets in, bytes in, packets out, bytes out, state creations) of
filter rules with labels, useful for accounting.
If
.Fl R Ar id
is specified as well,
only the statistics for the rule with the specified numeric ID are shown.
.It Fl s Cm timeouts
Show the current global timeouts.
.It Fl s Cm memory
Show the current pool memory hard limits.
.It Fl s Cm Tables
Show the list of tables.
.It Fl s Cm osfp
Show the list of operating system fingerprints.
.It Fl s Cm Interfaces
Show the list of interfaces and interface groups available to PF.
When used together with
.Fl v ,
it additionally lists which interfaces have skip rules activated.
When used together with
.Fl vv ,
interface statistics are also shown.
.Fl i
can be used to select an interface or a group of interfaces.
.It Fl s Cm all
Show all of the above, except for the lists of interfaces and operating
system fingerprints.
.El
.Pp
Counters shown with
.Fl s Cm info
are:
.Pp
.Bl -tag -width xxxxxxxxxxxxxx -compact
.It match
explicit rule match
.It bad-offset
currently unused
.It fragment
invalid fragments dropped
.It short
short packets dropped
.It normalize
dropped by normalizer: illegal packets
.It memory
memory could not be allocated
.It bad-timestamp
bad TCP timestamp; RFC 1323
.It congestion
network interface queue congested
.It ip-option
bad IP/IPv6 options
.It proto-cksum
invalid protocol checksum
.It state-mismatch
packet was associated with a state entry, but sequence numbers did not match
.It state-insert
state insertion failure
.It state-limit
configured state limit was reached
.It src-limit
source node/connection limit
.It synproxy
dropped by synproxy
.It translate
no free ports in translation port range
.It no-route
dropped by no-route
.El
.It Fl T Ar command Op Ar address ...
Specify the
.Ar command
(may be abbreviated) to apply to the table.
Commands include:
.Pp
.Bl -tag -width xxxxxxxxxxxx -compact
.It Fl T Cm kill
Kill a table.
.It Fl T Cm flush
Flush all addresses of a table.
.It Fl T Cm add
Add one or more addresses in a table.
Automatically create a persistent table if it does not exist.
.It Fl T Cm delete
Delete one or more addresses from a table.
.It Fl T Cm expire Ar number
Delete addresses which had their statistics cleared more than
.Ar number
seconds ago.
For entries which have never had their statistics cleared,
.Ar number
refers to the time they were added to the table.
.It Fl T Cm replace
Replace the addresses of the table.
Automatically create a persistent table if it does not exist.
.It Fl T Cm show
Show the content (addresses) of a table.
.It Fl T Cm test
Test if the given addresses match a table.
.It Fl T Cm zero
Clear all the statistics of a table.
.El
.Pp
For the
.Cm add ,
.Cm delete ,
.Cm replace ,
and
.Cm 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.
Comments starting with a
.Sq #
are allowed in the text file.
With these commands, the
.Fl v
flag can also be used once or twice, in which case
.Nm
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 matches
.Po
.Cm test
operation only
.Pc .
.It X
The address/network is duplicated and therefore ignored.
.It Y
The address/network cannot be added/deleted due to conflicting
.Sq \&!
attributes.
.It Z
The address/network has been cleared (statistics).
.El
.Pp
Each table can maintain a set of counters that can be retrieved using the
.Fl v
flag of
.Nm .
For example, the following commands define a wide open firewall which will keep
track of packets going to or coming from the
.Ox
FTP server.
The following commands configure the firewall and send 10 pings to the FTP
server:
.Bd -literal -offset indent
# printf "table <test> counters { ftp.openbsd.org }\en \e
    pass out to <test>\en" | pfctl -f-
# ping -qc10 ftp.openbsd.org
.Ed
.Pp
We can now use the table
.Cm show
command to output, for each address and packet direction, the number of packets
and bytes that are being passed, matched or blocked by rules referencing the
table.
Note that the match counters are incremented for every match rule in which
they are referenced, meaning that a single packet may be counted multiple times.
The time at which the current accounting started is also shown with the
.Dq Cleared
line.
.Bd -literal -offset indent
# pfctl -t test -vTshow
   198.51.100.81
        Cleared:        Fri Jun 28 11:17:37 2013
        In/Block:       [ Packets: 0	Bytes: 0	]
        In/Match        [ Packets: 54	Bytes: 10028	]
        In/Pass:        [ Packets: 5	Bytes: 1949	]
        Out/Block:      [ Packets: 0	Bytes: 0	]
        Out/Match       [ Packets: 65	Bytes: 12684	]
        Out/Pass:       [ Packets: 6	Bytes: 389	]
.Ed
.Pp
Similarly, it is possible to view global information about the tables
by using the
.Fl v
modifier twice and the
.Fl s
.Cm 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:
.Bd -literal -offset indent
# pfctl -vvsTables
--a-r-C test
        Addresses:   1
        Cleared:     Fri Jun 28 11:17:37 2013
        References:  [ Anchors: 0	Rules: 4	]
        Evaluations: [ NoMatch: 35	Match: 8	]
        In/Block:    [ Packets: 0	Bytes: 0	]
        In/Match:    [ Packets: 54	Bytes: 10028	]
        In/Pass:     [ Packets: 5	Bytes: 1949	]
        In/XPass:    [ Packets: 0	Bytes: 0	]
        Out/Block:   [ Packets: 0	Bytes: 0	]
        Out/Match:   [ Packets: 65	Bytes: 12684	]
        Out/Pass:    [ Packets: 6	Bytes: 389	]
        Out/XPass:   [ Packets: 0	Bytes: 0	]
.Ed
.Pp
Only packets creating state are matched in the Evaluations line,
but all packets passing as a result of the state are correctly accounted for.
Reloading the table(s) or ruleset will not affect packet accounting in any way.
The two
.Dq XPass
counters are incremented instead of the
.Dq Pass
counters when a
.Dq stateful
packet is passed but doesn't match the table anymore.
This will happen in our example if someone flushes the table while the
.Xr ping 8
command is running.
.Pp
When used with a single
.Fl v ,
.Nm
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
.Xr pf.conf 5 .
.It p
For persistent tables, which don't get automatically killed when no rules
refer to them.
.It a
For tables which are part of the
.Em active
tableset.
Tables without this flag do not really exist, cannot contain addresses, and are
only listed if the
.Fl g
flag is given.
.It i
For tables which are part of the
.Em inactive
tableset.
This flag can only be witnessed briefly during the loading of
.Xr pf.conf 5 .
.It r
For tables which are referenced (used) by rules.
.It 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.
.It C
This flag is set when per-address counters are enabled on the table.
.El
.It Fl t Ar table
Specify the name of the table.
.It Fl V Ar rdomain
Select the routing domain to be used to kill states by host or by label.
The rdomain of a state is displayed in parentheses before the host by
.Fl s Cm states .
.It Fl v
Produce more verbose output.
A second use of
.Fl v
will produce even more verbose output including ruleset warnings.
See the previous section for its effect on table commands.
.It Fl x Ar level
Set the debug
.Ar level ,
which limits the severity of log messages printed by
.Xr pf 4 .
This should be a keyword from the following ordered list
(highest to lowest):
.Cm emerg ,
.Cm alert ,
.Cm crit ,
.Cm err ,
.Cm warning ,
.Cm notice ,
.Cm info ,
and
.Cm debug .
These keywords correspond to the similar (LOG_) values specified to the
.Xr syslog 3
library routine,
and may be abbreviated on the command line.
.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.
.It Pa /etc/pf.os
Passive operating system fingerprint database.
.El
.Sh SEE ALSO
.Xr pf 4 ,
.Xr pf.conf 5 ,
.Xr pf.os 5 ,
.Xr sysctl.conf 5 ,
.Xr authpf 8 ,
.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 .