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PF(4)			 BSD Kernel Interfaces Manual			 PF(4)

NAME
     pf — packet filter

SYNOPSIS
     device pf

DESCRIPTION
     Packet filtering takes place in the kernel.  A pseudo-device, /dev/pf,
     allows userland processes to control the behavior of the packet filter
     through an ioctl(2) interface.  There are commands to enable and disable
     the filter, load rulesets, add and remove individual rules or state table
     entries, and retrieve statistics.	The most commonly used functions are
     covered by pfctl(8).

     Manipulations like loading a ruleset that involve more than a single
     ioctl(2) call require a so-called ticket, which prevents the occurrence
     of multiple concurrent manipulations.

     Fields of ioctl(2) parameter structures that refer to packet data (like
     addresses and ports) are generally expected in network byte-order.

     Rules and address tables are contained in so-called anchors.  When ser‐
     vicing an ioctl(2) request, if the anchor field of the argument structure
     is empty, the kernel will use the default anchor (i.e., the main ruleset)
     in operations.  Anchors are specified by name and may be nested, with
     components separated by ‘/’ characters, similar to how file system hier‐
     archies are laid out.  The final component of the anchor path is the
     anchor under which operations will be performed.

IOCTL INTERFACE
     pf supports the following ioctl(2) commands, available through
     ⟨net/pfvar.h⟩:

     DIOCSTART
	     Start the packet filter.

     DIOCSTOP
	     Stop the packet filter.

     DIOCSTARTALTQ
	     Start the ALTQ bandwidth control system (see altq(9)).

     DIOCSTOPALTQ
	     Stop the ALTQ bandwidth control system.

     DIOCBEGINADDRS struct pfioc_pooladdr *pp

	     struct pfioc_pooladdr {
		     u_int32_t		     action;
		     u_int32_t		     ticket;
		     u_int32_t		     nr;
		     u_int32_t		     r_num;
		     u_int8_t		     r_action;
		     u_int8_t		     r_last;
		     u_int8_t		     af;
		     char		     anchor[MAXPATHLEN];
		     struct pf_pooladdr	     addr;
	     };

	     Clear the buffer address pool and get a ticket for subsequent
	     DIOCADDADDR, DIOCADDRULE, and DIOCCHANGERULE calls.

     DIOCADDADDR struct pfioc_pooladdr *pp

	     Add the pool address addr to the buffer address pool to be used
	     in the following DIOCADDRULE or DIOCCHANGERULE call.  All other
	     members of the structure are ignored.

     DIOCADDRULE struct pfioc_rule *pr

	     struct pfioc_rule {
		     u_int32_t	     action;
		     u_int32_t	     ticket;
		     u_int32_t	     pool_ticket;
		     u_int32_t	     nr;
		     char	     anchor[MAXPATHLEN];
		     char	     anchor_call[MAXPATHLEN];
		     struct pf_rule  rule;
	     };

	     Add rule at the end of the inactive ruleset.  This call requires
	     a ticket obtained through a preceding DIOCXBEGIN call and a
	     pool_ticket obtained through a DIOCBEGINADDRS call.  DIOCADDADDR
	     must also be called if any pool addresses are required.  The
	     optional anchor name indicates the anchor in which to append the
	     rule.  nr and action are ignored.

     DIOCADDALTQ struct pfioc_altq *pa
	     Add an ALTQ discipline or queue.

	     struct pfioc_altq {
		     u_int32_t	     action;
		     u_int32_t	     ticket;
		     u_int32_t	     nr;
		     struct pf_altq  altq;
	     };

     DIOCGETRULES struct pfioc_rule *pr
	     Get a ticket for subsequent DIOCGETRULE calls and the number nr
	     of rules in the active ruleset.

     DIOCGETRULE struct pfioc_rule *pr
	     Get a rule by its number nr using the ticket obtained through a
	     preceding DIOCGETRULES call.  If action is set to
	     PF_GET_CLR_CNTR, the per-rule statistics on the requested rule
	     are cleared.

     DIOCGETADDRS struct pfioc_pooladdr *pp
	     Get a ticket for subsequent DIOCGETADDR calls and the number nr
	     of pool addresses in the rule specified with r_action, r_num, and
	     anchor.

     DIOCGETADDR struct pfioc_pooladdr *pp
	     Get the pool address addr by its number nr from the rule speci‐
	     fied with r_action, r_num, and anchor using the ticket obtained
	     through a preceding DIOCGETADDRS call.

     DIOCGETALTQS struct pfioc_altq *pa
	     Get a ticket for subsequent DIOCGETALTQ calls and the number nr
	     of queues in the active list.

     DIOCGETALTQ struct pfioc_altq *pa
	     Get the queueing discipline altq by its number nr using the
	     ticket obtained through a preceding DIOCGETALTQS call.

     DIOCGETQSTATS struct pfioc_qstats *pq
	     Get the statistics on a queue.

	     struct pfioc_qstats {
		     u_int32_t	      ticket;
		     u_int32_t	      nr;
		     void	     *buf;
		     int	      nbytes;
		     u_int8_t	      scheduler;
	     };

	     This call fills in a pointer to the buffer of statistics buf, of
	     length nbytes, for the queue specified by nr.

     DIOCGETRULESETS struct pfioc_ruleset *pr

	     struct pfioc_ruleset {
		     u_int32_t	      nr;
		     char	      path[MAXPATHLEN];
		     char	      name[PF_ANCHOR_NAME_SIZE];
	     };

	     Get the number nr of rulesets (i.e., anchors) directly attached
	     to the anchor named by path for use in subsequent DIOCGETRULESET
	     calls.  Nested anchors, since they are not directly attached to
	     the given anchor, will not be included.  This ioctl returns
	     EINVAL if the given anchor does not exist.

     DIOCGETRULESET struct pfioc_ruleset *pr
	     Get a ruleset (i.e., an anchor) name by its number nr from the
	     given anchor path, the maximum number of which can be obtained
	     from a preceding DIOCGETRULESETS call.  This ioctl returns EINVAL
	     if the given anchor does not exist or EBUSY if another process is
	     concurrently updating a ruleset.

     DIOCADDSTATE struct pfioc_state *ps
	     Add a state entry.

	     struct pfioc_state {
		     u_int32_t	      nr;
		     struct pf_state  state;
	     };

     DIOCGETSTATE struct pfioc_state *ps
	     Extract the entry with the specified number nr from the state ta‐
	     ble.

     DIOCKILLSTATES struct pfioc_state_kill *psk
	     Remove matching entries from the state table.  This ioctl returns
	     the number of killed states in psk_af.

	     struct pfioc_state_kill {
		     sa_family_t	     psk_af;
		     int		     psk_proto;
		     struct pf_rule_addr     psk_src;
		     struct pf_rule_addr     psk_dst;
		     char		     psk_ifname[IFNAMSIZ];
	     };

     DIOCCLRSTATES struct pfioc_state_kill *psk
	     Clear all states.	It works like DIOCKILLSTATES, but ignores the
	     psk_af, psk_proto, psk_src, and psk_dst fields of the
	     pfioc_state_kill structure.

     DIOCSETSTATUSIF struct pfioc_if *pi
	     Specify the interface for which statistics are accumulated.

	     struct pfioc_if {
		     char	      ifname[IFNAMSIZ];
	     };

     DIOCGETSTATUS struct pf_status *s
	     Get the internal packet filter statistics.

	     struct pf_status {
		     u_int64_t	     counters[PFRES_MAX];
		     u_int64_t	     lcounters[LCNT_MAX];
		     u_int64_t	     fcounters[FCNT_MAX];
		     u_int64_t	     scounters[SCNT_MAX];
		     u_int64_t	     pcounters[2][2][3];
		     u_int64_t	     bcounters[2][2];
		     u_int64_t	     stateid;
		     u_int32_t	     running;
		     u_int32_t	     states;
		     u_int32_t	     src_nodes;
		     u_int32_t	     since;
		     u_int32_t	     debug;
		     u_int32_t	     hostid;
		     char	     ifname[IFNAMSIZ];
		     u_int8_t	     pf_chksum[MD5_DIGEST_LENGTH];
	     };

     DIOCCLRSTATUS
	     Clear the internal packet filter statistics.

     DIOCNATLOOK struct pfioc_natlook *pnl
	     Look up a state table entry by source and destination addresses
	     and ports.

	     struct pfioc_natlook {
		     struct pf_addr   saddr;
		     struct pf_addr   daddr;
		     struct pf_addr   rsaddr;
		     struct pf_addr   rdaddr;
		     u_int16_t	      sport;
		     u_int16_t	      dport;
		     u_int16_t	      rsport;
		     u_int16_t	      rdport;
		     sa_family_t      af;
		     u_int8_t	      proto;
		     u_int8_t	      direction;
	     };

     DIOCSETDEBUG u_int32_t *level
	     Set the debug level.

	     enum    { PF_DEBUG_NONE, PF_DEBUG_URGENT, PF_DEBUG_MISC,
		       PF_DEBUG_NOISY };

     DIOCGETSTATES struct pfioc_states *ps
	     Get state table entries.

	     struct pfioc_states {
		     int     ps_len;
		     union {
			     caddr_t	      psu_buf;
			     struct pf_state *psu_states;
		     } ps_u;
	     #define ps_buf	     ps_u.psu_buf
	     #define ps_states	     ps_u.psu_states
	     };

	     If ps_len is non-zero on entry, as many states as possible that
	     can fit into this size will be copied into the supplied buffer
	     ps_states.	 On exit, ps_len is always set to the total size
	     required to hold all state table entries (i.e., it is set to
	     sizeof(struct pf_state) * nr).

     DIOCCHANGERULE struct pfioc_rule *pcr
	     Add or remove the rule in the ruleset specified by rule.action.

	     The type of operation to be performed is indicated by action,
	     which can be any of the following:

	     enum    { PF_CHANGE_NONE, PF_CHANGE_ADD_HEAD, PF_CHANGE_ADD_TAIL,
		       PF_CHANGE_ADD_BEFORE, PF_CHANGE_ADD_AFTER,
		       PF_CHANGE_REMOVE, PF_CHANGE_GET_TICKET };

	     ticket must be set to the value obtained with
	     PF_CHANGE_GET_TICKET for all actions except PF_CHANGE_GET_TICKET.
	     pool_ticket must be set to the value obtained with the
	     DIOCBEGINADDRS call for all actions except PF_CHANGE_REMOVE and
	     PF_CHANGE_GET_TICKET.  anchor indicates to which anchor the oper‐
	     ation applies.  nr indicates the rule number against which
	     PF_CHANGE_ADD_BEFORE, PF_CHANGE_ADD_AFTER, or PF_CHANGE_REMOVE
	     actions are applied.

     DIOCCHANGEADDR struct pfioc_pooladdr *pca
	     Add or remove the pool address addr from the rule specified by
	     r_action, r_num, and anchor.

     DIOCSETTIMEOUT struct pfioc_tm *pt

	     struct pfioc_tm {
		     int	      timeout;
		     int	      seconds;
	     };

	     Set the state timeout of timeout to seconds.  The old value will
	     be placed into seconds.  For possible values of timeout, consult
	     the PFTM_* values in ⟨net/pfvar.h⟩.

     DIOCGETTIMEOUT struct pfioc_tm *pt
	     Get the state timeout of timeout.	The value will be placed into
	     the seconds field.

     DIOCCLRRULECTRS
	     Clear per-rule statistics.

     DIOCSETLIMIT struct pfioc_limit *pl
	     Set the hard limits on the memory pools used by the packet fil‐
	     ter.

	     struct pfioc_limit {
		     int	     index;
		     unsigned	     limit;
	     };

	     enum    { PF_LIMIT_STATES, PF_LIMIT_SRC_NODES, PF_LIMIT_FRAGS,
		       PF_LIMIT_TABLES, PF_LIMIT_TABLE_ENTRIES, PF_LIMIT_MAX };

     DIOCGETLIMIT struct pfioc_limit *pl
	     Get the hard limit for the memory pool indicated by index.

     DIOCRCLRTABLES struct pfioc_table *io
	     Clear all tables.	All the ioctls that manipulate radix tables
	     use the same structure described below.  For DIOCRCLRTABLES,
	     pfrio_ndel contains on exit the number of tables deleted.

	     struct pfioc_table {
		     struct pfr_table	      pfrio_table;
		     void		     *pfrio_buffer;
		     int		      pfrio_esize;
		     int		      pfrio_size;
		     int		      pfrio_size2;
		     int		      pfrio_nadd;
		     int		      pfrio_ndel;
		     int		      pfrio_nchange;
		     int		      pfrio_flags;
		     u_int32_t		      pfrio_ticket;
	     };
	     #define pfrio_exists    pfrio_nadd
	     #define pfrio_nzero     pfrio_nadd
	     #define pfrio_nmatch    pfrio_nadd
	     #define pfrio_naddr     pfrio_size2
	     #define pfrio_setflag   pfrio_size2
	     #define pfrio_clrflag   pfrio_nadd

     DIOCRADDTABLES struct pfioc_table *io
	     Create one or more tables.	 On entry, pfrio_buffer must point to
	     an array of struct pfr_table containing at least pfrio_size ele‐
	     ments.  pfrio_esize must be the size of struct pfr_table.	On
	     exit, pfrio_nadd contains the number of tables effectively cre‐
	     ated.

	     struct pfr_table {
		     char	     pfrt_anchor[MAXPATHLEN];
		     char	     pfrt_name[PF_TABLE_NAME_SIZE];
		     u_int32_t	     pfrt_flags;
		     u_int8_t	     pfrt_fback;
	     };

     DIOCRDELTABLES struct pfioc_table *io
	     Delete one or more tables.	 On entry, pfrio_buffer must point to
	     an array of struct pfr_table containing at least pfrio_size ele‐
	     ments.  pfrio_esize must be the size of struct pfr_table.	On
	     exit, pfrio_ndel contains the number of tables effectively
	     deleted.

     DIOCRGETTABLES struct pfioc_table *io
	     Get the list of all tables.  On entry, pfrio_buffer[pfrio_size]
	     contains a valid writeable buffer for pfr_table structures.  On
	     exit, pfrio_size contains the number of tables written into the
	     buffer.  If the buffer is too small, the kernel does not store
	     anything but just returns the required buffer size, without
	     error.

     DIOCRGETTSTATS struct pfioc_table *io
	     This call is like DIOCRGETTABLES but is used to get an array of
	     pfr_tstats structures.

	     struct pfr_tstats {
		     struct pfr_table pfrts_t;
		     u_int64_t	      pfrts_packets
					  [PFR_DIR_MAX][PFR_OP_TABLE_MAX];
		     u_int64_t	      pfrts_bytes
					  [PFR_DIR_MAX][PFR_OP_TABLE_MAX];
		     u_int64_t	      pfrts_match;
		     u_int64_t	      pfrts_nomatch;
		     long	      pfrts_tzero;
		     int	      pfrts_cnt;
		     int	      pfrts_refcnt[PFR_REFCNT_MAX];
	     };
	     #define pfrts_name	      pfrts_t.pfrt_name
	     #define pfrts_flags      pfrts_t.pfrt_flags

     DIOCRCLRTSTATS struct pfioc_table *io
	     Clear the statistics of one or more tables.  On entry,
	     pfrio_buffer must point to an array of struct pfr_table contain‐
	     ing at least pfrio_size elements.	pfrio_esize must be the size
	     of struct pfr_table.  On exit, pfrio_nzero contains the number of
	     tables effectively cleared.

     DIOCRCLRADDRS struct pfioc_table *io
	     Clear all addresses in a table.  On entry, pfrio_table contains
	     the table to clear.  On exit, pfrio_ndel contains the number of
	     addresses removed.

     DIOCRADDADDRS struct pfioc_table *io
	     Add one or more addresses to a table.  On entry, pfrio_table con‐
	     tains the table ID and pfrio_buffer must point to an array of
	     struct pfr_addr containing at least pfrio_size elements to add to
	     the table.	 pfrio_esize must be the size of struct pfr_addr.  On
	     exit, pfrio_nadd contains the number of addresses effectively
	     added.

	     struct pfr_addr {
		     union {
			     struct in_addr   _pfra_ip4addr;
			     struct in6_addr  _pfra_ip6addr;
		     }		      pfra_u;
		     u_int8_t	      pfra_af;
		     u_int8_t	      pfra_net;
		     u_int8_t	      pfra_not;
		     u_int8_t	      pfra_fback;
	     };
	     #define pfra_ip4addr    pfra_u._pfra_ip4addr
	     #define pfra_ip6addr    pfra_u._pfra_ip6addr

     DIOCRDELADDRS struct pfioc_table *io
	     Delete one or more addresses from a table.	 On entry, pfrio_table
	     contains the table ID and pfrio_buffer must point to an array of
	     struct pfr_addr containing at least pfrio_size elements to delete
	     from the table.  pfrio_esize must be the size of struct pfr_addr.
	     On exit, pfrio_ndel contains the number of addresses effectively
	     deleted.

     DIOCRSETADDRS struct pfioc_table *io
	     Replace the content of a table by a new address list.  This is
	     the most complicated command, which uses all the structure mem‐
	     bers.

	     On entry, pfrio_table contains the table ID and pfrio_buffer must
	     point to an array of struct pfr_addr containing at least
	     pfrio_size elements which become the new contents of the table.
	     pfrio_esize must be the size of struct pfr_addr.  Additionally,
	     if pfrio_size2 is non-zero, pfrio_buffer[pfrio_size..pfrio_size2]
	     must be a writeable buffer, into which the kernel can copy the
	     addresses that have been deleted during the replace operation.
	     On exit, pfrio_ndel, pfrio_nadd, and pfrio_nchange contain the
	     number of addresses deleted, added, and changed by the kernel.
	     If pfrio_size2 was set on entry, pfrio_size2 will point to the
	     size of the buffer used, exactly like DIOCRGETADDRS.

     DIOCRGETADDRS struct pfioc_table *io
	     Get all the addresses of a table.	On entry, pfrio_table contains
	     the table ID and pfrio_buffer[pfrio_size] contains a valid write‐
	     able buffer for pfr_addr structures.  On exit, pfrio_size con‐
	     tains the number of addresses written into the buffer.  If the
	     buffer was too small, the kernel does not store anything but just
	     returns the required buffer size, without returning an error.

     DIOCRGETASTATS struct pfioc_table *io
	     This call is like DIOCRGETADDRS but is used to get an array of
	     pfr_astats structures.

	     struct pfr_astats {
		     struct pfr_addr  pfras_a;
		     u_int64_t	      pfras_packets
					  [PFR_DIR_MAX][PFR_OP_ADDR_MAX];
		     u_int64_t	      pfras_bytes
					  [PFR_DIR_MAX][PFR_OP_ADDR_MAX];
		     long	      pfras_tzero;
	     };

     DIOCRCLRASTATS struct pfioc_table *io
	     Clear the statistics of one or more addresses.  On entry,
	     pfrio_table contains the table ID and pfrio_buffer must point to
	     an array of struct pfr_addr containing at least pfrio_size ele‐
	     ments to be cleared from the table.  pfrio_esize must be the size
	     of struct pfr_addr.  On exit, pfrio_nzero contains the number of
	     addresses effectively cleared.

     DIOCRTSTADDRS struct pfioc_table *io
	     Test if the given addresses match a table.	 On entry, pfrio_table
	     contains the table ID and pfrio_buffer must point to an array of
	     struct pfr_addr containing at least pfrio_size elements, each of
	     which will be tested for a match in the table.  pfrio_esize must
	     be the size of struct pfr_addr.  On exit, the kernel updates the
	     pfr_addr array by setting the pfra_fback member appropriately.

     DIOCRSETTFLAGS struct pfioc_table *io
	     Change the PFR_TFLAG_CONST or PFR_TFLAG_PERSIST flags of a table.
	     On entry, pfrio_buffer must point to an array of struct pfr_table
	     containing at least pfrio_size elements.  pfrio_esize must be the
	     size of struct pfr_table.	pfrio_setflag must contain the flags
	     to add, while pfrio_clrflag must contain the flags to remove.  On
	     exit, pfrio_nchange and pfrio_ndel contain the number of tables
	     altered or deleted by the kernel.	Yes, tables can be deleted if
	     one removes the PFR_TFLAG_PERSIST flag of an unreferenced table.

     DIOCRINADEFINE struct pfioc_table *io
	     Defines a table in the inactive set.  On entry, pfrio_table con‐
	     tains the table ID and pfrio_buffer[pfrio_size] contains an array
	     of pfr_addr structures to put in the table.  A valid ticket must
	     also be supplied to pfrio_ticket.	On exit, pfrio_nadd contains 0
	     if the table was already defined in the inactive list or 1 if a
	     new table has been created.  pfrio_naddr contains the number of
	     addresses effectively put in the table.

     DIOCXBEGIN struct pfioc_trans *io

	     struct pfioc_trans {
		     int	      size;  /* number of elements */
		     int	      esize; /* size of each element in bytes */
		     struct pfioc_trans_e {
			     int	     rs_num;
			     char	     anchor[MAXPATHLEN];
			     u_int32_t	     ticket;
		     }		     *array;
	     };

	     Clear all the inactive rulesets specified in the pfioc_trans_e
	     array.  For each ruleset, a ticket is returned for subsequent
	     "add rule" ioctls, as well as for the DIOCXCOMMIT and
	     DIOCXROLLBACK calls.

	     Ruleset types, identified by rs_num, include the following:

		PF_RULESET_SCRUB   Scrub (packet normalization) rules.
		PF_RULESET_FILTER  Filter rules.
		PF_RULESET_NAT	   NAT (Network Address Translation) rules.
		PF_RULESET_BINAT   Bidirectional NAT rules.
		PF_RULESET_RDR	   Redirect rules.
		PF_RULESET_ALTQ	   ALTQ disciplines.
		PF_RULESET_TABLE   Address tables.

     DIOCXCOMMIT struct pfioc_trans *io
	     Atomically switch a vector of inactive rulesets to the active
	     rulesets.	This call is implemented as a standard two-phase com‐
	     mit, which will either fail for all rulesets or completely suc‐
	     ceed.  All tickets need to be valid.  This ioctl returns EBUSY if
	     another process is concurrently updating some of the same rule‐
	     sets.

     DIOCXROLLBACK struct pfioc_trans *io
	     Clean up the kernel by undoing all changes that have taken place
	     on the inactive rulesets since the last DIOCXBEGIN.
	     DIOCXROLLBACK will silently ignore rulesets for which the ticket
	     is invalid.

     DIOCSETHOSTID u_int32_t *hostid
	     Set the host ID, which is used by pfsync(4) to identify which
	     host created state table entries.

     DIOCOSFPFLUSH
	     Flush the passive OS fingerprint table.

     DIOCOSFPADD struct pf_osfp_ioctl *io

	     struct pf_osfp_ioctl {
		     struct pf_osfp_entry {
			     SLIST_ENTRY(pf_osfp_entry) fp_entry;
			     pf_osfp_t		     fp_os;
			     char		     fp_class_nm[PF_OSFP_LEN];
			     char		     fp_version_nm[PF_OSFP_LEN];
			     char		     fp_subtype_nm[PF_OSFP_LEN];
		     }			     fp_os;
		     pf_tcpopts_t	     fp_tcpopts;
		     u_int16_t		     fp_wsize;
		     u_int16_t		     fp_psize;
		     u_int16_t		     fp_mss;
		     u_int16_t		     fp_flags;
		     u_int8_t		     fp_optcnt;
		     u_int8_t		     fp_wscale;
		     u_int8_t		     fp_ttl;
		     int		     fp_getnum;
	     };

	     Add a passive OS fingerprint to the table.	 Set fp_os.fp_os to
	     the packed fingerprint, fp_os.fp_class_nm to the name of the
	     class (Linux, Windows, etc), fp_os.fp_version_nm to the name of
	     the version (NT, 95, 98), and fp_os.fp_subtype_nm to the name of
	     the subtype or patchlevel.	 The members fp_mss, fp_wsize,
	     fp_psize, fp_ttl, fp_optcnt, and fp_wscale are set to the TCP
	     MSS, the TCP window size, the IP length, the IP TTL, the number
	     of TCP options, and the TCP window scaling constant of the TCP
	     SYN packet, respectively.

	     The fp_flags member is filled according to the ⟨net/pfvar.h⟩
	     include file PF_OSFP_* defines.  The fp_tcpopts member contains
	     packed TCP options.  Each option uses PF_OSFP_TCPOPT_BITS bits in
	     the packed value.	Options include any of PF_OSFP_TCPOPT_NOP,
	     PF_OSFP_TCPOPT_SACK, PF_OSFP_TCPOPT_WSCALE, PF_OSFP_TCPOPT_MSS,
	     or PF_OSFP_TCPOPT_TS.

	     The fp_getnum member is not used with this ioctl.

	     The structure's slack space must be zeroed for correct operation;
	     memset(3) the whole structure to zero before filling and sending
	     to the kernel.

     DIOCOSFPGET struct pf_osfp_ioctl *io
	     Get the passive OS fingerprint number fp_getnum from the kernel's
	     fingerprint list.	The rest of the structure members will come
	     back filled.  Get the whole list by repeatedly incrementing the
	     fp_getnum number until the ioctl returns EBUSY.

     DIOCGETSRCNODES struct pfioc_src_nodes *psn

	     struct pfioc_src_nodes {
		     int     psn_len;
		     union {
			     caddr_t	     psu_buf;
			     struct pf_src_node	     *psu_src_nodes;
		     } psn_u;
	     #define psn_buf	     psn_u.psu_buf
	     #define psn_src_nodes   psn_u.psu_src_nodes
	     };

	     Get the list of source nodes kept by sticky addresses and source
	     tracking.	The ioctl must be called once with psn_len set to 0.
	     If the ioctl returns without error, psn_len will be set to the
	     size of the buffer required to hold all the pf_src_node struc‐
	     tures held in the table.  A buffer of this size should then be
	     allocated, and a pointer to this buffer placed in psn_buf.	 The
	     ioctl must then be called again to fill this buffer with the
	     actual source node data.  After that call, psn_len will be set to
	     the length of the buffer actually used.

     DIOCCLRSRCNODES
	     Clear the tree of source tracking nodes.

     DIOCIGETIFACES struct pfioc_iface *io
	     Get the list of interfaces and interface drivers known to pf.
	     All the ioctls that manipulate interfaces use the same structure
	     described below:

	     struct pfioc_iface {
		     char		      pfiio_name[IFNAMSIZ];
		     void		     *pfiio_buffer;
		     int		      pfiio_esize;
		     int		      pfiio_size;
		     int		      pfiio_nzero;
		     int		      pfiio_flags;
	     };

	     If not empty, pfiio_name can be used to restrict the search to a
	     specific interface or driver.  pfiio_buffer[pfiio_size] is the
	     user-supplied buffer for returning the data.  On entry,
	     pfiio_size contains the number of pfi_kif entries that can fit
	     into the buffer.  The kernel will replace this value by the real
	     number of entries it wants to return.  pfiio_esize should be set
	     to sizeof(struct pfi_kif).

	     The data is returned in the pfi_kif structure described below:

	     struct pfi_kif {
		     RB_ENTRY(pfi_kif)		      pfik_tree;
		     char			      pfik_name[IFNAMSIZ];
		     u_int64_t			      pfik_packets[2][2][2];
		     u_int64_t			      pfik_bytes[2][2][2];
		     u_int32_t			      pfik_tzero;
		     int			      pfik_flags;
		     struct pf_state_tree_lan_ext     pfik_lan_ext;
		     struct pf_state_tree_ext_gwy     pfik_ext_gwy;
		     TAILQ_ENTRY(pfi_kif)	      pfik_w_states;
		     void			     *pfik_ah_cookie;
		     struct ifnet		     *pfik_ifp;
		     struct ifg_group		     *pfik_group;
		     int			      pfik_states;
		     int			      pfik_rules;
		     TAILQ_HEAD(, pfi_dynaddr)	      pfik_dynaddrs;
	     };

     DIOCSETIFFLAG struct pfioc_iface *io
	     Set the user setable flags (described above) of the pf internal
	     interface description.  The filtering process is the same as for
	     DIOCIGETIFACES.

	     #define PFI_IFLAG_SKIP	     0x0100  /* skip filtering on interface */

     DIOCCLRIFFLAG struct pfioc_iface *io
	     Works as DIOCSETIFFLAG above but clears the flags.

FILES
     /dev/pf  packet filtering device.

EXAMPLES
     The following example demonstrates how to use the DIOCNATLOOK command to
     find the internal host/port of a NATed connection:

     #include <sys/types.h>
     #include <sys/socket.h>
     #include <sys/ioctl.h>
     #include <sys/fcntl.h>
     #include <net/if.h>
     #include <netinet/in.h>
     #include <net/pfvar.h>
     #include <err.h>
     #include <stdio.h>
     #include <stdlib.h>

     u_int32_t
     read_address(const char *s)
     {
	     int a, b, c, d;

	     sscanf(s, "%i.%i.%i.%i", &a, &b, &c, &d);
	     return htonl(a << 24 | b << 16 | c << 8 | d);
     }

     void
     print_address(u_int32_t a)
     {
	     a = ntohl(a);
	     printf("%d.%d.%d.%d", a >> 24 & 255, a >> 16 & 255,
		 a >> 8 & 255, a & 255);
     }

     int
     main(int argc, char *argv[])
     {
	     struct pfioc_natlook nl;
	     int dev;

	     if (argc != 5) {
		     printf("%s <gwy addr> <gwy port> <ext addr> <ext port>\n",
			 argv[0]);
		     return 1;
	     }

	     dev = open("/dev/pf", O_RDWR);
	     if (dev == -1)
		     err(1, "open(\"/dev/pf\") failed");

	     memset(&nl, 0, sizeof(struct pfioc_natlook));
	     nl.saddr.v4.s_addr	     = read_address(argv[1]);
	     nl.sport		     = htons(atoi(argv[2]));
	     nl.daddr.v4.s_addr	     = read_address(argv[3]);
	     nl.dport		     = htons(atoi(argv[4]));
	     nl.af		     = AF_INET;
	     nl.proto		     = IPPROTO_TCP;
	     nl.direction	     = PF_IN;

	     if (ioctl(dev, DIOCNATLOOK, &nl))
		     err(1, "DIOCNATLOOK");

	     printf("internal host ");
	     print_address(nl.rsaddr.v4.s_addr);
	     printf(":%u\n", ntohs(nl.rsport));
	     return 0;
     }

SEE ALSO
     ioctl(2), altq(4), if_bridge(4), pflog(4), pfsync(4), pfctl(8), altq(9)

HISTORY
     The pf packet filtering mechanism first appeared in OpenBSD 3.0.

BSD			       February 7, 2005				   BSD
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