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pfil.h revision 1.28.70.1
      1 /*	$NetBSD: pfil.h,v 1.28.70.1 2008/06/23 04:31:58 wrstuden 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  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #ifndef _NET_PFIL_H_
     30 #define _NET_PFIL_H_
     31 
     32 #ifdef _KERNEL_OPT
     33 #include "opt_pfil_hooks.h"
     34 #endif
     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_ALL	(PFIL_IN|PFIL_OUT)
     57 #define PFIL_WAITOK	0x00000004
     58 #define PFIL_IFADDR	0x00000008
     59 #define PFIL_IFNET	0x00000010
     60 
     61 /* events notified by PFIL_IFNET */
     62 #define	PFIL_IFNET_ATTACH	0
     63 #define	PFIL_IFNET_DETACH	1
     64 
     65 typedef	TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t;
     66 
     67 #define	PFIL_TYPE_AF		1	/* key is AF_* type */
     68 #define	PFIL_TYPE_IFNET		2	/* key is ifnet pointer */
     69 
     70 struct pfil_head {
     71 	pfil_list_t	ph_in;
     72 	pfil_list_t	ph_out;
     73 	pfil_list_t	ph_ifaddr;
     74 	pfil_list_t	ph_ifnetevent; /* XXX naming collision */
     75 	int		ph_type;
     76 	union {
     77 		u_long		phu_val;
     78 		void		*phu_ptr;
     79 	} ph_un;
     80 #define	ph_af		ph_un.phu_val
     81 #define	ph_ifnet	ph_un.phu_ptr
     82 	LIST_ENTRY(pfil_head) ph_list;
     83 };
     84 typedef struct pfil_head pfil_head_t;
     85 
     86 #ifdef _KERNEL
     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 #endif /* _KERNEL */
    118 
    119 /* XXX */
    120 #if defined(_KERNEL_OPT)
    121 #include "ipfilter.h"
    122 #endif
    123 
    124 #if NIPFILTER > 0
    125 #ifdef PFIL_HOOKS
    126 #undef PFIL_HOOKS
    127 #endif
    128 #define PFIL_HOOKS
    129 #endif /* NIPFILTER */
    130 
    131 #ifdef _KERNEL
    132 /* in sys/net/if.c */
    133 extern struct pfil_head if_pfil; /* packet filtering hook for interfaces */
    134 #endif /* _KERNEL */
    135 
    136 #endif /* !_NET_PFIL_H_ */
    137