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pfil.h revision 1.21 
      1 /*	$NetBSD: pfil.h,v 1.21 2003/06/23 11:02:11 martin 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 "opt_pfil_hooks.h"
     35 
     36 #include <sys/queue.h>
     37 #include <net/dlt.h>
     38 #include <sys/null.h>
     39 
     40 struct mbuf;
     41 struct ifnet;
     42 
     43 /*
     44  * The packet filter hooks are designed for anything to call them to
     45  * possibly intercept the packet.
     46  */
     47 struct packet_filter_hook {
     48         TAILQ_ENTRY(packet_filter_hook) pfil_link;
     49 	int	(*pfil_func)(void *, struct mbuf **, struct ifnet *, int);
     50 	void	*pfil_arg;
     51 	int	pfil_flags;
     52 };
     53 
     54 #define PFIL_IN		0x00000001
     55 #define PFIL_OUT	0x00000002
     56 #define PFIL_WAITOK	0x00000004
     57 #define PFIL_ALL	(PFIL_IN|PFIL_OUT)
     58 
     59 typedef	TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t;
     60 
     61 #define	PFIL_TYPE_AF		1	/* key is AF_* type */
     62 #define	PFIL_TYPE_IFNET		2	/* key is ifnet pointer */
     63 
     64 struct pfil_head {
     65 	pfil_list_t	ph_in;
     66 	pfil_list_t	ph_out;
     67 	int		ph_type;
     68 	union {
     69 		u_long		phu_val;
     70 		void		*phu_ptr;
     71 	} ph_un;
     72 #define	ph_af		ph_un.phu_val
     73 #define	ph_ifnet	ph_un.phu_ptr
     74 	LIST_ENTRY(pfil_head) ph_list;
     75 };
     76 typedef struct pfil_head pfil_head_t;
     77 
     78 int	pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *,
     79 	    int);
     80 
     81 int	pfil_add_hook(int (*func)(void *, struct mbuf **,
     82 	    struct ifnet *, int), void *, int, struct pfil_head *);
     83 int	pfil_remove_hook(int (*func)(void *, struct mbuf **,
     84 	    struct ifnet *, int), void *, int, struct pfil_head *);
     85 
     86 int	pfil_head_register(struct pfil_head *);
     87 int	pfil_head_unregister(struct pfil_head *);
     88 
     89 struct pfil_head *pfil_head_get(int, u_long);
     90 
     91 static __inline struct packet_filter_hook *
     92 pfil_hook_get(int dir, struct pfil_head *ph)
     93 {
     94 
     95 	if (dir == PFIL_IN)
     96 		return (TAILQ_FIRST(&ph->ph_in));
     97 	else if (dir == PFIL_OUT)
     98 		return (TAILQ_FIRST(&ph->ph_out));
     99 	else
    100 		return (NULL);
    101 }
    102 
    103 /* XXX */
    104 #if defined(_KERNEL_OPT)
    105 #include "ipfilter.h"
    106 #endif
    107 
    108 #if NIPFILTER > 0
    109 #ifdef PFIL_HOOKS
    110 #undef PFIL_HOOKS
    111 #endif
    112 #define PFIL_HOOKS
    113 #endif /* NIPFILTER */
    114 
    115 #endif /* _NET_PFIL_H_ */
    116