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pfil.h revision 1.15 
      1 /*	$NetBSD: pfil.h,v 1.15 2000/12/12 18:03:25 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1996 Matthew R. Green
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. The name of the author may not be used to endorse or promote products
     16  *    derived from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     25  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 #ifndef _NET_PFIL_H_
     32 #define _NET_PFIL_H_
     33 
     34 #include <sys/queue.h>
     35 #include <net/dlt.h>
     36 
     37 struct mbuf;
     38 struct ifnet;
     39 
     40 /*
     41  * The packet filter hooks are designed for anything to call them to
     42  * possibly intercept the packet.
     43  */
     44 struct packet_filter_hook {
     45         TAILQ_ENTRY(packet_filter_hook) pfil_link;
     46 	int	(*pfil_func)(void *, struct mbuf **, struct ifnet *, int);
     47 	void	*pfil_arg;
     48 	int	pfil_flags;
     49 };
     50 
     51 #define PFIL_IN		0x00000001
     52 #define PFIL_OUT	0x00000002
     53 #define PFIL_WAITOK	0x00000004
     54 #define PFIL_ALL	(PFIL_IN|PFIL_OUT)
     55 
     56 typedef	TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t;
     57 
     58 struct pfil_head {
     59 	pfil_list_t	ph_in;
     60 	pfil_list_t	ph_out;
     61 	void		*ph_key;
     62 	int		ph_dlt;
     63 	LIST_ENTRY(pfil_head) ph_list;
     64 };
     65 typedef struct pfil_head pfil_head_t;
     66 
     67 int	pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *,
     68 	    int);
     69 
     70 int	pfil_add_hook(int (*func)(void *, struct mbuf **,
     71 	    struct ifnet *, int), void *, int, struct pfil_head *);
     72 int	pfil_remove_hook(int (*func)(void *, struct mbuf **,
     73 	    struct ifnet *, int), void *, int, struct pfil_head *);
     74 
     75 int	pfil_head_register(struct pfil_head *);
     76 int	pfil_head_unregister(struct pfil_head *);
     77 
     78 struct pfil_head *pfil_head_get(void *, int);
     79 
     80 static __inline struct packet_filter_hook *
     81 pfil_hook_get(int dir, struct pfil_head *ph)
     82 {
     83 
     84 	if (dir == PFIL_IN)
     85 		return (TAILQ_FIRST(&ph->ph_in));
     86 	else if (dir == PFIL_OUT)
     87 		return (TAILQ_FIRST(&ph->ph_out));
     88 	else
     89 		return (NULL);
     90 }
     91 
     92 /* XXX */
     93 #if defined(_KERNEL) && !defined(_LKM)
     94 #include "ipfilter.h"
     95 #endif
     96 
     97 #if NIPFILTER > 0
     98 #ifdef PFIL_HOOKS
     99 #undef PFIL_HOOKS
    100 #endif
    101 #define PFIL_HOOKS
    102 #endif /* NIPFILTER */
    103 
    104 #endif /* _NET_PFIL_H_ */
    105