pfctl



PFCTL(8)                OpenBSD System Manager's Manual               PFCTL(8)


NAME

     pfctl - control the packet filter (PF) device


SYNOPSIS

     pfctl [-deghnPqrvz] [-a anchor] [-D macro=value] [-F modifier] [-f file]
           [-i interface] [-K host | network] [-k host | network | label | id]
           [-L statefile] [-o level] [-p device] [-S statefile]
           [-s modifier [-R id]] [-t table -T command [address ...]]
           [-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, and -s 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

     -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):

             -F queue      Flush the queue rules.
             -F rules      Flush the filter rules.
             -F states     Flush the state table (NAT and filter).
             -F Sources    Flush the source tracking table.
             -F info       Flush the filter information (statistics that are
                           not bound to rules).
             -F Tables     Flush the tables.
             -F osfp       Flush the passive operating system fingerprints.
             -F all        Flush all of the above.

     -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 host | network
             Kill all of the source tracking entries originating from the
             specified host or network.  A second -K host or -K network option
             may be specified, which will kill all the source tracking entries
             from the first host/network to the second.

     -k host | network | label | id
             Kill all of the state entries matching the specified host,
             network, label, or id.

             For example, to kill all of the state entries originating from
             ``host'':

                   # pfctl -k host

             A second -k host or -k network option may be specified, which
             will kill all the state entries from the first host/network to
             the second.  To kill all of the state entries from ``host1'' to
             ``host2'':

                   # pfctl -k host1 -k host2

             To kill all states originating from 192.168.1.0/24 to
             172.16.0.0/16:

                   # pfctl -k 192.168.1.0/24 -k 172.16.0.0/16

             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 or state ID.  In
             this mode the first -k argument is used to specify the type of
             the second argument.  The following command would kill all states
             that have been created from rules carrying the label ``foobar'':

                   # pfctl -k label -k foobar

             To kill one specific state by its unique state ID (as shown by
             pfctl -s state -vv), use the id modifier and as a second argument
             the state ID and optional creator ID.  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 actually load rules, just parse them.

     -o level
             Control the ruleset optimizer, overriding any rule file settings.

             -o none       Disable the ruleset optimizer.
             -o basic      Enable basic ruleset optimizations.  This is the
                           default behaviour.
             -o 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 when displaying them.

     -S statefile
             Store the pf state table in the file specified by statefile.

     -s modifier
             Show the filter parameters specified by modifier (may be
             abbreviated):

             -s queue        Show the currently loaded queue rules.  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.
             -s 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.  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).
             -s 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.
             -s states       Show the contents of the state table.
             -s Sources      Show the contents of the source tracking table.
             -s info         Show filter information (statistics and
                             counters).  When used together with -v, source
                             tracking statistics are also shown.
             -s 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.
             -s timeouts     Show the current global timeouts.
             -s memory       Show the current pool memory hard limits.
             -s Tables       Show the list of tables.
             -s osfp         Show the list of operating system fingerprints.
             -s Interfaces   Show the list of interfaces and interface drivers
                             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.
             -s 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

     -T command [address ...]
             Specify the command (may be abbreviated) to apply to the table.
             Commands include:

             -T kill       Kill a table.
             -T flush      Flush all addresses of a table.
             -T add        Add one or more addresses in a table.
                           Automatically create a nonexisting table.
             -T delete     Delete one or more addresses from a table.
             -T 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.
             -T replace    Replace the addresses of the table.  Automatically
                           create a nonexisting table.
             -T show       Show the content (addresses) of a table.
             -T test       Test if the given addresses match a table.
             -T zero       Clear all the statistics of a table.

             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.

     -t table
             Specify the name of the table.

     -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.

OpenBSD 5.4                      July 21, 2013                     OpenBSD 5.4

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