sys/net/pfil.h

   1 /*      $NetBSD: pfil.h,v 1.28 2006/02/16 20:17:20 perry 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_ */