pf

Packet Filter pseudo-device

Name:

/dev/pf

Description:

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

Manipulations such as loading a rule set that involve more than a single ioctl() call require a ticket, which prevents the occurrence of multiple concurrent manipulations.

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

Rules and address tables are contained in anchors. When servicing an ioctl() request, if the anchor field of the argument structure is empty, io-pkt uses the default anchor (i.e. the main rule set) in operations. Anchors are specified by name and may be nested, with components separated by slashes, similar to the way that filesystem hierarchies are laid out. The final component of the anchor path is the anchor under which operations will be performed.

ioctl() interface

The pf pseudo-device supports the following ioctl() 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 in the NetBSD documentation).
DIOCSTOPALTQ
Stop the ALTQ bandwidth control system.
DIOCBEGINADDRS struct pfioc_pooladdr *pp
Clear the buffer address pool and get a ticket for subsequent DIOCADDADDR, DIOCADDRULE, and DIOCCHANGERULE calls. The pfioc_pooladdr structure is defined as follows:
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;
};
  
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
Add the given rule at the end of the inactive rule set. The pfioc_rule structure is defined as follows:
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;
};
  

This call requires a ticket obtained through a preceding DIOCXBEGIN call and a pool_ticket obtained through a DIOCBEGINADDRS call. You must also call DIOCADDADDR if any pool addresses are required.

The optional anchor name indicates the anchor in which to append the rule. The nr and action members. are ignored.

DIOCADDALTQ struct pfioc_altq *pa
Add an ALTQ discipline or queue. The pfioc_altq structure is defined as follows:
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 rule set.
DIOCGETRULE struct pfioc_rule *pr
Get a rule by its number nr, using the ticket obtained through a preceding DIOCGETRULES call.
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 specified 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 for a queue. The pfioc_qstats structure is defined as follows:
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
Get the number nr of rule sets (i.e., anchors) directly attached to the anchor named by path for use in subsequent DIOCGETRULESET calls. The pfioc_ruleset structure is defined as follows:
struct pfioc_ruleset {
        u_int32_t        nr;
        char             path[MAXPATHLEN];
        char             name[PF_ANCHOR_NAME_SIZE];
};
  

Nested anchors, since they aren't directly attached to the given anchor, aren't included. This ioctl() command returns EINVAL if the given anchor doesn't exist.

DIOCGETRULESET struct pfioc_ruleset *pr
Get a rule set (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() command returns EINVAL if the given anchor doesn't exist, or EBUSY if another process is concurrently updating a rule set.
DIOCADDSTATE struct pfioc_state *ps
Add a state entry. The pfioc_state structure is defined as follows:
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 table.
DIOCKILLSTATES struct pfioc_state_kill *psk
Remove matching entries from the state table. This ioctl() command returns the number of killed states in psk_af. The pfioc_state_kill structure is defined as follows:
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. This command 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 to gather statistics. The pfioc_if structure is defined as follows:
struct pfioc_if {
        char             ifname[IFNAMSIZ];
};
  
DIOCGETSTATUS struct pf_status *s
Get the internal packet filter statistics. The pf_status structure is defined as follows:
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];
};
  
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. The pfioc_natlook structure is defined as follows:
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 to one of PF_DEBUG_NONE, PF_DEBUG_URGENT, PF_DEBUG_MISC, or PF_DEBUG_NOISY.
DIOCGETSTATES struct pfioc_states *ps
Get state table entries. The pfioc_states structure is defined as follows:
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 zero, all states are gathered into pf_states, and ps_len is set to the size they take in memory (i.e. sizeof(struct pf_state) * nr). If ps_len is nonzero, as many states that can fit into ps_len as possible are gathered, and ps_len is updated to the size those rules take in memory.

DIOCCHANGERULE struct pfioc_rule *pcr
Add or remove the rule in the rule set specified by rule.action. The type of operation to be performed is indicated by action, which can be any of the following:
  • 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

You must set ticket to the value obtained with PF_CHANGE_GET_TICKET for all actions except PF_CHANGE_GET_TICKET. You must set pool_ticket to the value obtained with the DIOCBEGINADDRS call for all actions except PF_CHANGE_REMOVE and PF_CHANGE_GET_TICKET. The anchor indicates which anchor the operation applies to. The nr member indicates the rule number against which to apply PF_CHANGE_ADD_BEFORE, PF_CHANGE_ADD_AFTER, or PF_CHANGE_REMOVE actions.

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
Set the state timeout of timeout to seconds. The pfioc_tm structure is defined as follows:
struct pfioc_tm {
        int timeout;
        int seconds;
};
  

The old value is placed into seconds. For the possible values of timeout, see the PFTM_* values in <net/pfvar.h>.

DIOCGETTIMEOUT struct pfioc_tm *pt
Get the state timeout of timeout. The value is 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 filter. The pfioc_limit structure is defined as follows:
struct pfioc_limit {
        int        index;
        unsigned   limit;
};

enum { PF_LIMIT_STATES, PF_LIMIT_SRC_NODES,
       PF_LIMIT_FRAGS };
  
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 ioctl() commands that manipulate radix tables use the same structure described below. On exit from the DIOCRCLRTABLES command, pfrio_ndel contains the number of tables deleted. The pfioc_table structure is defined as follows:
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[pfrio_size] contains a table of pfr_table structures. On exit, pfrio_nadd contains the number of tables effectively created. The pfr_table structure is defined as follows:
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[pfrio_size] contains a table of pfr_table structures. On exit, pfrio_nadd contains the number of tables effectively deleted.
DIOCRGETTABLES struct pfioc_table *io
Get a 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, io-pkt doesn't 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. The pfr_tstats structure is defined as follows:
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[pfrio_size] contains a table of pfr_table structures. 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 contains the table ID, and pfrio_buffer[pfrio_size] contains the list of pfr_addr structures to add. On exit, pfrio_nadd contains the number of addresses effectively added.

The pfr_addr structure is defined as follows:

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[pfrio_size] contains the list of pfr_addr structures to delete. 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 members.

On entry, pfrio_table contains the table ID, and pfrio_buffer[pfrio_size] contains the new list of pfr_addr structures. Additionally, if pfrio_size2 is nonzero, pfrio_buffer[pfrio_size..pfrio_size2] must be a writeable buffer, into which io-pkt 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 io-pkt. If pfrio_size2 was set on entry, pfrio_size2 points to the size of the buffer used, exactly as for 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 writeable buffer for pfr_addr structures. On exit, pfrio_size contains the number of addresses written into the buffer. If the buffer is too small, io-pkt doesn't 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[pfrio_size] contains a table of pfr_addr structures to clear. 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[pfrio_size] contains a table of pfr_addr structures to test. On exit, io-pkt updates the pfr_addr table 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[pfrio_size] contains a table of pfr_table structures, and pfrio_setflag contains the flags to add, while pfrio_clrflag contains the flags to remove. On exit, pfrio_nchange and pfrio_ndel contain the number of tables altered or deleted by io-pkt.

You can delete tables if you remove the PFR_TFLAG_PERSIST flag of an unreferenced table.

DIOCRINADEFINE struct pfioc_table *io
Define a table in the inactive set. On entry, pfrio_table contains the table ID, and pfrio_buffer[pfrio_size] contains the list 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. The pfrio_naddr member contains the number of addresses effectively put in the table.
DIOCXBEGIN struct pfioc_trans *io
Clear all the inactive rule sets specified in the pfioc_trans_e array. The pfioc_trans structure is defined as follows:
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;
};
  

For each rule set, a ticket is returned for subsequent "add rule" ioctl() commands, as well as for the DIOCXCOMMIT and DIOCXROLLBACK calls.

Rule set 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 rule sets to the active rule sets. This call is implemented as a standard two-phase commit, which either fails for all rule sets, or completely succeeds. All tickets need to be valid. This ioctl() command returns EBUSY if another process is concurrently updating some of the same rule sets.
DIOCXROLLBACK struct pfioc_trans *io
Clean up io-pkt by undoing all changes that have taken place on the inactive rule sets since the last DIOCXBEGIN. DIOCXROLLBACK silently ignores rule sets for which the ticket is invalid.
DIOCSETHOSTID u_int32_t *hostid
Set the host ID, which is used by pfsync to identify which host created state table entries.
DIOCOSFPFLUSH
Flush the passive OS fingerprint table.
DIOCOSFPADD struct pf_osfp_ioctl *io
Add a passive OS fingerprint to the table. The pf_osfp_ioctl structure is defined as follows:
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;
};
  

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 patch level. 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 PF_OSFP_* definition in <net/pfvar.h>. 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.

This ioctl() command doesn't use the fp_getnum member.

You must zero the structure's slack space for correct operation; memset() the whole structure to zero before filling and sending it to io-pkt.

DIOCOSFPGET struct pf_osfp_ioctl *io
Get the passive OS fingerprint number fp_getnum from io-pkt's fingerprint list. The rest of the structure members comes back filled. Get the whole list by repeatedly incrementing the fp_getnum number until ioctl() gives an error of EBUSY.
DIOCGETSRCNODES struct pfioc_src_nodes *psn
Get the list of source nodes kept by sticky addresses and source tracking. The pfioc_src_nodes structure is defined as follows:
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
};
  

You must call ioctl() once with psn_len set to 0. If ioctl() returns without error, psn_len is set to the size of the buffer required to hold all the pf_src_node structures held in the table. You should then allocate a buffer of this size and place a pointer to this buffer in psn_buf. You must then call ioctl() again to fill this buffer with the actual source node data. After that call, psn_len is set to the length of the buffer actually used.

DIOCCLRSRCNODES
Clear the tree of source-tracking nodes.
DIOCIGETIFACES struct pfioc_iface *io
Get a list of interfaces and interface drivers known to pf. All the ioctl() commands that manipulate interfaces use the 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;
};

#define PFI_FLAG_GROUP     0x0001  /* gets groups of interfaces */
#define PFI_FLAG_INSTANCE  0x0002  /* gets single interfaces */
#define PFI_FLAG_ALLMASK   0x0003
  

If it isn't empty, you can use pfiio_name to restrict the search to a specific interface or driver. The pfiio_buffer[pfiio_size] member is the user-supplied buffer for returning the data. On entry, pfiio_size represents the number of pfi_if entries that can fit into the buffer. The io-pkt manager replaces this value with the real number of entries it wants to return.

You should set pfiio_esize to sizeof(struct pfi_if). You should set pfiio_flags to PFI_FLAG_GROUP, PFI_FLAG_INSTANCE, or both, to tell io-pkt to return a group of interfaces (drivers, such as fxp), real interface instances (e.g. fxp1), or both. The data is returned in the pfi_if structure described below:

struct pfi_if {
        char        pfif_name[IFNAMSIZ];
        u_int64_t   pfif_packets[2][2][2];
        u_int64_t   pfif_bytes[2][2][2];
        u_int64_t   pfif_addcnt;
        u_int64_t   pfif_delcnt;
        long        pfif_tzero;
        int         pfif_states;
        int         pfif_rules;
        int         pfif_flags;
};

#define PFI_IFLAG_GROUP    0x0001  /* group of interfaces */
#define PFI_IFLAG_INSTANCE 0x0002  /* single instance */
#define PFI_IFLAG_CLONABLE 0x0010  /* clonable group */
#define PFI_IFLAG_DYNAMIC  0x0020  /* dynamic group */
#define PFI_IFLAG_ATTACHED 0x0040  /* interface attached */
  
DIOCICLRISTATS struct pfioc_iface *io
Clear the statistics counters of one or more interfaces. You can use pfiio_name and pfiio_flags to select which interfaces need to be cleared. The filtering process is the same as for DIOCIGETIFACES. The pfiio_nzero member is set by io-pkt to the number of interfaces and drivers that have been cleared.
DIOCSETIFFLAG struct pfioc_iface *io
Set the user-setable flags of the pf internal interface description:
  • PFI_IFLAG_SKIP — skip the interface.

The filtering process is the same as for DIOCIGETIFACES.

DIOCCLRIFFLAG struct pfioc_iface *io
Similar to DIOCSETIFFLAG, but clear the flags.

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;
}

Caveats:

The following functionality is missing from pf in this version of NetBSD:

  • The pfsync protocol isn't supported.
  • The group keyword isn't supported.

Last modified: 2014-05-14



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