.\" $OpenBSD: pfctl.8,v 1.102 2003/09/18 09:18:51 jmc 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 November 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 AdeghnNqrROvz .Op Fl a Ar anchor Ns Op Ar :ruleset .Op Fl D Ar macro=value .Op Fl f Ar file .Op Fl F Ar modifier .Op Fl k Ar host .Op Fl s Ar modifier .Op Fl t Ar table .Op Fl T Ar command Op Ar address ... .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. .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 .Ar 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 .Ar anchor points, which are also referenced by name. Evaluation of .Ar anchor rules from the main ruleset is described in .Xr pf.conf 5 . For example, to show all filter rules inside anchor .Li foo : .Bd -literal -offset indent # pfctl -a foo -s rules .Ed .Pp Private tables can also be put inside subrulesets, 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 fallback to the table defined in the main ruleset, if there is one. This is similar to C rules for variables. 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. .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 .Ar macro to be set to .Ar value on the command line. Overrides the definition of .Ar macro in the ruleset. .It Fl e Enable the packet filter. .It Fl f Ar file Load 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 F Ar modifier Flush the filter parameters specified by .Ar modifier (may be abbreviated): .Pp .Bl -tag -width xxxxxxxxxxxx -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 osfp Flush the passive operating system fingerprints. .It Fl F Ar all Flush all of the above. .El .It Fl g Include output helpful for debugging. .It Fl k Ar host Kill all of the state entries originating from the specified .Ar host . A second .Fl k Ar host option may be specified, which will kill all the state entries from the first .Ar host to the second .Ar host . For example, to kill all of the state entries originating from .Li host : .Bd -literal -offset indent # pfctl -k host .Ed .Pp To kill all of the state entries from .Li host1 to .Li host2 : .Bd -literal -offset indent # 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 the filter parameters specified by .Ar modifier (may be abbreviated): .Pp .Bl -tag -width xxxxxxxxxxxx -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 .Fl 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 (label, evaluations, packets, bytes) 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 osfp Show the list of operating system fingerprints. Can be used in combination with .Fl o Ar file to list the fingerprints in a .Xr pf.os 5 file. .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 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 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 .Xr pf.conf 5 . This is used in conjunction with the .Fl f flag, as in: .Bd -literal -offset indent # pfctl -Tl -f pf.conf .Ed .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. Comments starting with a "#" 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 matches (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 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 { ftp.openbsd.org }\en \e \ \ pass out to keep state\en" \&| pfctl -f- # 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. .Bd -literal -offset indent # pfctl -t test -vTshow \ \ \ 129.128.5.191 \ \ \ \ Cleared: \ \ \ \ Thu Feb 13 18:55:18 2003 \ \ \ \ In/Block: \ \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ] \ \ \ \ In/Pass: \ \ \ \ [ Packets: 10 \ \ \ \ \ \ Bytes: 840 \ \ \ \ \ ] \ \ \ \ Out/Block: \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ] \ \ \ \ Out/Pass: \ \ \ [ Packets: 10 \ \ \ \ \ \ Bytes: 840 \ \ \ \ \ ] .Ed .Pp Similarly, it is possible to view global information about the tables by using the .Fl v modifier twice 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: .Bd -literal -offset indent # pfctl -vvsTables --a-r- test \ \ \ \ Addresses: \ \ 1 \ \ \ \ Cleared: \ \ \ \ Thu Feb 13 18:55:18 2003 \ \ \ \ References: \ [ Anchors: 0 \ \ \ \ \ \ \ Rules: 1 \ \ \ \ \ \ \ ] \ \ \ \ Evaluations: [ NoMatch: 3496 \ \ \ \ Match: 1 \ \ \ \ \ \ \ ] \ \ \ \ In/Block: \ \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ] \ \ \ \ In/Pass: \ \ \ \ [ Packets: 10 \ \ \ \ \ \ Bytes: 840 \ \ \ \ \ ] \ \ \ \ In/XPass: \ \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ] \ \ \ \ Out/Block: \ \ [ Packets: 0 \ \ \ \ \ \ \ Bytes: 0 \ \ \ \ \ \ \ ] \ \ \ \ Out/Pass: \ \ \ [ Packets: 10 \ \ \ \ \ \ Bytes: 840 \ \ \ \ \ ] \ \ \ \ 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 as the result of the state are correctly accounted for. Reloading the table(s) or ruleset will not affect packet accounting in any way. 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 .Xr pf.conf 5 . .It p For persistent tables, which don't get automatically flushed when no rules refer 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 only listed if the .Fl g 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 .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 in sub-rulesets (anchors). .El .It Fl v Produce more verbose output. A second use of .Fl v will produce even more verbose output including ruleset warnings. See previous section for its effect on table commands. .It Fl x Ar level Set the debug .Ar level (may be abbreviated) to one of the following: .Pp .Bl -tag -width xxxxxxxxxxxx -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. .It Fl x Ar loud Generate debug messages for common conditions. .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 pf.os 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 .