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Command: pfctl | Section: 8 | Source: OpenBSD | File: pfctl.8
PFCTL(8) FreeBSD System Manager's Manual PFCTL(8)
NAME
pfctl - control the packet filter (PF) device
SYNOPSIS
pfctl [-deghNnPqrvz] [-a anchor] [-D macro=value] [-F modifier] [-f file]
[-i interface] [-K key] [-k key] [-L statefile] [-o level]
[-p device] [-S statefile] [-s modifier [-R id]]
[-t table -T command [address ...]] [-V rdomain] [-x level]
DESCRIPTION
The pfctl utility communicates with the packet filter device using the
ioctl interface described in 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 pf.conf(5). The packet filter can also replace
addresses and ports of packets.
The packet filter is enabled by default. Should pfctl 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 RULES variable
in rc(8) remains in place.
The packet filter does not itself forward packets between interfaces.
Forwarding can be enabled by setting the sysctl(8) variables
net.inet.ip.forwarding and/or net.inet6.ip6.forwarding to 1. Set them
permanently in sysctl.conf(5).
At least one option must be specified. The options are as follows:
-a anchor
Apply flags -f, -F, -s, and -T only to the rules in the specified
anchor. In addition to the main ruleset, pfctl can load and
manipulate additional rulesets by name, called anchors. The main
ruleset is the default anchor.
Anchors are referenced by name and may be nested, with the
various components of the anchor path separated by `/'
characters, similar to how file system hierarchies are laid out.
The last component of the anchor path is where ruleset operations
are performed.
Evaluation of anchor rules from the main ruleset is described in
pf.conf(5).
For example, the following will show all filter rules (see the -s
flag below) inside the anchor "authpf/smith(1234)", which would
have been created for user "smith" by authpf(8), PID 1234:
# pfctl -a "authpf/smith(1234)" -s rules
Private tables can also be put inside anchors, either by having
table statements in the pf.conf(5) file that is loaded in the
anchor, or by using regular table commands, as in:
# pfctl -a foo/bar -t mytable -T add 1.2.3.4 5.6.7.8
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.
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 `*' character, the -s flag will
recursively print all anchors in a brace delimited block. For
example the following will print the "authpf" ruleset
recursively:
# pfctl -a 'authpf/*' -sr
To print the main ruleset recursively, specify only `*' as the
anchor name:
# pfctl -a '*' -sr
To flush all rulesets and tables recursively, specify only `*' as
the anchor name:
# pfctl -a '*' -Fa
-D macro=value
Define macro to be set to value on the command line. Overrides
the definition of macro in the ruleset.
-d Disable the packet filter.
-e Enable the packet filter.
-F modifier
Flush the filter parameters specified by modifier (may be
abbreviated):
rules Flush the filter rules.
states Flush the state table (NAT and filter).
Sources Flush the source tracking table.
info Flush the filter information (statistics that are not
bound to rules).
Tables Flush the tables.
osfp Flush the passive operating system fingerprints.
Reset Reset limits, timeouts and other options back to
default settings. See the OPTIONS section in
pf.conf(5) for details.
all Flush all of the above.
If -a is specified as well and anchor is terminated with a `*'
character, rules, Tables and all flush the given anchor
recursively.
-f file
Replace the current ruleset with the rules contained in 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.
-g Include output helpful for debugging.
-h Help.
-i interface
Restrict the operation to the given interface.
-K key Kill all of the source tracking entries originating from the host
or network specified by key. A second -K option may be
specified, which will kill all the source tracking entries from
the first host/network to the second.
-k key Kill all of the state entries originating from the host or
network specified by key. A second -k option may be specified,
which will kill all the state entries from the first host/network
to the second.
A network prefix length of 0 can be used as a wildcard. To kill
all states with the target "host2":
# pfctl -k 0.0.0.0/0 -k host2
It is also possible to kill states by rule label, state key, or
state ID. In this mode the first -k argument is used to specify
the type; a second -k gives the actual target.
To kill states by rule label, use the label modifier. To kill
all states created from rules carrying the label "foobar":
# pfctl -k label -k foobar
To kill one specific state by its state key (as shown by pfctl -s
state), use the key modifier. To kill a state originating from
10.0.0.101:32123 to 10.0.0.1:80, protocol TCP, use:
# pfctl -k key -k 'tcp 10.0.0.1:80 <- 10.0.0.101:32123'
To kill one specific state by its unique state ID (as shown by
pfctl -s state -vv), use the id modifier. To kill a state with
ID 4823e84500000003 use:
# pfctl -k id -k 4823e84500000003
To kill a state with ID 4823e84500000018 created from a backup
firewall with hostid 00000002 use:
# pfctl -k id -k 4823e84500000018/2
-L statefile
Load pf states from the file specified by statefile.
-N Do not perform domain name resolution. If a name cannot be
resolved without DNS, an error will be reported.
-n Do not actually load rules, just parse them.
-o level
Control the ruleset optimizer, overriding any rule file settings.
none Disable the ruleset optimizer.
basic Enable basic ruleset optimizations. This is the
default behaviour.
profile Enable basic ruleset optimizations with profiling.
For further information on the ruleset optimizer, see pf.conf(5).
-P Print ports using their names in /etc/services if available.
-p device
Use the device file device instead of the default /dev/pf.
-q Only print errors and warnings.
-r Perform reverse DNS lookups on states and tables when displaying
them. -N and -r are mutually exclusive.
-S statefile
Store the pf state table in the file specified by statefile.
-s modifier [-R id]
Show the filter parameters specified by modifier (may be
abbreviated):
queue Show the currently loaded queue definitions. When
used together with -v, per-queue statistics are also
shown. When used together with -v -v, pfctl will
loop and show updated queue statistics every five
seconds, including measured bandwidth and packets
per second.
rules Show the currently loaded filter rules. If -R id is
specified as well, only the rule with the specified
numeric ID is shown. When used together with -v,
the per-rule statistics (number of evaluations,
packets and bytes) are also shown. When used
together with -g or -vv, expired rules (marked as "#
expired") 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).
Anchors Show the currently loaded anchors directly attached
to the main ruleset. If -a anchor is specified as
well, the anchors loaded directly below the given
anchor are shown instead. If -v is specified, all
anchors attached under the target anchor will be
displayed recursively.
states Show the contents of the state table. If -R id is
specified as well, only states created by the rule
with the specified numeric ID are shown.
Sources Show the contents of the source tracking table.
info Show filter information (statistics and counters).
When used together with -v, source tracking
statistics, the firewall's 32-bit hostid number and
the main ruleset's MD5 checksum for use with
pfsync(4) are also shown.
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 -R id
is specified as well, only the statistics for the
rule with the specified numeric ID are shown.
timeouts Show the current global timeouts.
memory Show the current pool memory hard limits.
Tables Show the list of tables.
osfp Show the list of operating system fingerprints.
Interfaces Show the list of interfaces and interface groups
available to PF. When used together with -v, it
additionally lists which interfaces have skip rules
activated. When used together with -vv, interface
statistics are also shown. -i can be used to select
an interface or a group of interfaces.
all Show all of the above, except for the lists of
interfaces and operating system fingerprints.
Counters shown with -s info are:
match explicit rule match
bad-offset currently unused
fragment invalid fragments dropped
short short packets dropped
normalize dropped by normalizer: illegal packets
memory memory could not be allocated
bad-timestamp bad TCP timestamp; RFC 1323
congestion network interface queue congested
ip-option bad IP/IPv6 options
proto-cksum invalid protocol checksum
state-mismatch packet was associated with a state entry, but
sequence numbers did not match
state-insert state insertion failure
state-limit configured state limit was reached
src-limit source node/connection limit
synproxy dropped by synproxy
translate no free ports in translation port range
no-route dropped by no-route
-t table -T command [address ...]
Specify the command (may be abbreviated) to apply to table.
Commands include:
add Add one or more addresses to a table.
Automatically create a persistent table if it does
not exist.
delete Delete one or more addresses from a table.
expire number Delete addresses which had their statistics
cleared more than number seconds ago. For entries
which have never had their statistics cleared,
number refers to the time they were added to the
table.
flush Flush all addresses in a table.
kill Kill a table.
replace Replace the addresses of the table. Automatically
create a persistent table if it does not exist.
show Show the content (addresses) of a table.
test Test if the given addresses match a table.
zero Clear all the statistics of a table, or only for
specified addresses.
For the add, delete, replace, and test commands, the list of
addresses can be specified either directly on the command line
and/or in an unformatted text file, using the -f flag. Comments
starting with a `#' are allowed in the text file. With these
commands, the -v flag can also be used once or twice, in which
case pfctl will print the detailed result of the operation for
each individual address, prefixed by one of the following
letters:
A The address/network has been added.
C The address/network has been changed (negated).
D The address/network has been deleted.
M The address matches (test operation only).
X The address/network is duplicated and therefore ignored.
Y The address/network cannot be added/deleted due to
conflicting `!' attributes.
Z The address/network has been cleared (statistics).
Each table can maintain a set of counters that can be retrieved
using the -v flag of pfctl. For example, the following commands
define a wide open firewall which will keep track of packets
going to or coming from the OpenBSD FTP server. The following
commands configure the firewall and send 10 pings to the FTP
server:
# printf "table <test> counters { ftp.openbsd.org }\n \
pass out to <test>\n" | pfctl -f-
# ping -qc10 ftp.openbsd.org
We can now use the table 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 "Cleared" line.
# 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 ]
Similarly, it is possible to view global information about the
tables by using the -v modifier twice and the -s 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:
# 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 ]
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 "XPass" counters are
incremented instead of the "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(8) command is running.
When used with a single -v, pfctl will only display the first
line containing the table flags and name. The flags are defined
as follows:
c For constant tables, which cannot be altered outside
pf.conf(5).
p For persistent tables, which don't get automatically killed
when no rules refer to them.
a For tables which are part of the active tableset. Tables
without this flag do not really exist, cannot contain
addresses, and are only listed if the -g flag is given.
i For tables which are part of the inactive tableset. This
flag can only be witnessed briefly during the loading of
pf.conf(5).
r For tables which are referenced (used) by rules.
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.
C This flag is set when per-address counters are enabled on
the table.
-V 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 -s states.
-v Produce more verbose output. A second use of -v will produce
even more verbose output including ruleset warnings. See the
previous section for its effect on table commands.
-x level
Set the debug level, which limits the severity of log messages
printed by pf(4). This should be a keyword from the following
ordered list (highest to lowest): emerg, alert, crit, err,
warning, notice, info, and debug. These keywords correspond to
the similar (LOG_) values specified to the syslog(3) library
routine, and may be abbreviated on the command line.
-z Clear per-rule statistics.
FILES
/etc/pf.conf Packet filter rules file.
/etc/pf.os Passive operating system fingerprint database.
SEE ALSO
pf(4), pf.conf(5), pf.os(5), sysctl.conf(5), authpf(8), ftp-proxy(8),
rc(8), rc.conf(8), sysctl(8)
HISTORY
The pfctl program and the pf(4) filter mechanism first appeared in
OpenBSD 3.0.
FreeBSD 14.1-RELEASE-p8 November 21, 2024 FreeBSD 14.1-RELEASE-p8