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pfil.h revision 1.24 
      1 /*	$NetBSD: pfil.h,v 1.24 2004/07/27 12:22:59 yamt 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 #ifdef _KERNEL_OPT
     35 #include "opt_pfil_hooks.h"
     36 #endif
     37 
     38 #include <sys/queue.h>
     39 #include <net/dlt.h>
     40 #include <sys/null.h>
     41 
     42 struct mbuf;
     43 struct ifnet;
     44 
     45 /*
     46  * The packet filter hooks are designed for anything to call them to
     47  * possibly intercept the packet.
     48  */
     49 struct packet_filter_hook {
     50         TAILQ_ENTRY(packet_filter_hook) pfil_link;
     51 	int	(*pfil_func)(void *, struct mbuf **, struct ifnet *, int);
     52 	void	*pfil_arg;
     53 	int	pfil_flags;
     54 };
     55 
     56 #define PFIL_IN		0x00000001
     57 #define PFIL_OUT	0x00000002
     58 #define PFIL_ALL	(PFIL_IN|PFIL_OUT)
     59 #define PFIL_WAITOK	0x00000004
     60 #define PFIL_IFADDR	0x00000008
     61 #define PFIL_IFNET	0x00000010
     62 
     63 /* events notified by PFIL_IFNET */
     64 #define	PFIL_IFNET_ATTACH	0
     65 #define	PFIL_IFNET_DETACH	1
     66 
     67 typedef	TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t;
     68 
     69 #define	PFIL_TYPE_AF		1	/* key is AF_* type */
     70 #define	PFIL_TYPE_IFNET		2	/* key is ifnet pointer */
     71 
     72 struct pfil_head {
     73 	pfil_list_t	ph_in;
     74 	pfil_list_t	ph_out;
     75 	pfil_list_t	ph_ifaddr;
     76 	pfil_list_t	ph_ifnetevent; /* XXX naming collision */
     77 	int		ph_type;
     78 	union {
     79 		u_long		phu_val;
     80 		void		*phu_ptr;
     81 	} ph_un;
     82 #define	ph_af		ph_un.phu_val
     83 #define	ph_ifnet	ph_un.phu_ptr
     84 	LIST_ENTRY(pfil_head) ph_list;
     85 };
     86 typedef struct pfil_head pfil_head_t;
     87 
     88 int	pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *,
     89 	    int);
     90 
     91 int	pfil_add_hook(int (*func)(void *, struct mbuf **,
     92 	    struct ifnet *, int), void *, int, struct pfil_head *);
     93 int	pfil_remove_hook(int (*func)(void *, struct mbuf **,
     94 	    struct ifnet *, int), void *, int, struct pfil_head *);
     95 
     96 int	pfil_head_register(struct pfil_head *);
     97 int	pfil_head_unregister(struct pfil_head *);
     98 
     99 struct pfil_head *pfil_head_get(int, u_long);
    100 
    101 static __inline struct packet_filter_hook *
    102 pfil_hook_get(int dir, struct pfil_head *ph)
    103 {
    104 
    105 	if (dir == PFIL_IN)
    106 		return (TAILQ_FIRST(&ph->ph_in));
    107 	else if (dir == PFIL_OUT)
    108 		return (TAILQ_FIRST(&ph->ph_out));
    109 	else if (dir == PFIL_IFADDR)
    110 		return (TAILQ_FIRST(&ph->ph_ifaddr));
    111 	else if (dir == PFIL_IFNET)
    112 		return (TAILQ_FIRST(&ph->ph_ifnetevent));
    113 	else
    114 		return (NULL);
    115 }
    116 
    117 /* XXX */
    118 #if defined(_KERNEL_OPT)
    119 #include "ipfilter.h"
    120 #endif
    121 
    122 #if NIPFILTER > 0
    123 #ifdef PFIL_HOOKS
    124 #undef PFIL_HOOKS
    125 #endif
    126 #define PFIL_HOOKS
    127 #endif /* NIPFILTER */
    128 
    129 #ifdef _KERNEL
    130 /* in sys/net/if.c */
    131 extern struct pfil_head if_pfil; /* packet filtering hook for interfaces */
    132 #endif
    133 
    134 #endif /* _NET_PFIL_H_ */
    135