sys/net/pfil.h

   1 /*      $NetBSD: pfil.h,v 1.22 2003/06/23 12:57:08 martin Exp $ */
   2 /* $DragonFly: src/sys/net/pfil.h,v 1.5 2006/05/20 02:42:08 dillon Exp $ */
   3
   4 /*
   5  * Copyright (c) 1996 Matthew R. Green
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #ifndef _NET_PFIL_H_
  33 #define _NET_PFIL_H_
  34
  35 #ifndef _SYS_TYPES_H_
  36 #include <sys/types.h>
  37 #endif
  38 #ifndef _SYS_PARAM_H_
  39 #include <sys/param.h>
  40 #endif
  41 #ifndef _SYS_QUEUE_H_
  42 #include <sys/queue.h>
  43 #endif
  44
  45 struct mbuf;
  46 struct ifnet;
  47
  48 /*
  49  * The packet filter hooks are designed for anything to call them to
  50  * possibly intercept the packet.
  51  */
  52 struct packet_filter_hook {
  53         TAILQ_ENTRY(packet_filter_hook) pfil_link;
  54         int     (*pfil_func)(void *, struct mbuf **, struct ifnet *, int);
  55         void    *pfil_arg;
  56         int     pfil_flags;
  57 };
  58
  59 #define PFIL_IN         0x00000001
  60 #define PFIL_OUT        0x00000002
  61 #define PFIL_WAITOK     0x00000004
  62 #define PFIL_ALL        (PFIL_IN|PFIL_OUT)
  63
  64 typedef TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t;
  65
  66 #define PFIL_TYPE_AF            1       /* key is AF_* type */
  67 #define PFIL_TYPE_IFNET         2       /* key is ifnet pointer */
  68
  69 struct pfil_head {
  70         pfil_list_t     ph_in;
  71         pfil_list_t     ph_out;
  72         int             ph_type;
  73         int             ph_hashooks;    /* 0 if no hooks installed */
  74         union {
  75                 u_long          phu_val;
  76                 void            *phu_ptr;
  77         } ph_un;
  78 #define ph_af           ph_un.phu_val
  79 #define ph_ifnet        ph_un.phu_ptr
  80         LIST_ENTRY(pfil_head) ph_list;
  81 };
  82 typedef struct pfil_head pfil_head_t;
  83
  84 int     pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *, int);
  85
  86 int     pfil_add_hook(int (*func)(void *, struct mbuf **,
  87             struct ifnet *, int), void *, int, struct pfil_head *);
  88 int     pfil_remove_hook(int (*func)(void *, struct mbuf **,
  89             struct ifnet *, int), void *, int, struct pfil_head *);
  90
  91 int     pfil_head_register(struct pfil_head *);
  92 int     pfil_head_unregister(struct pfil_head *);
  93
  94 struct pfil_head *pfil_head_get(int, u_long);
  95
  96 static __inline struct packet_filter_hook *
  97 pfil_hook_get(int dir, struct pfil_head *ph)
  98 {
  99
 100         if (dir == PFIL_IN)
 101                 return (TAILQ_FIRST(&ph->ph_in));
 102         else if (dir == PFIL_OUT)
 103                 return (TAILQ_FIRST(&ph->ph_out));
 104         else
 105                 return (NULL);
 106 }
 107
 108 /*
 109  * Used for a quick shortcut around the pfil routines if no hooks have been
 110  * installed.
 111  */
 112 static __inline int
 113 pfil_has_hooks(struct pfil_head *ph)
 114 {
 115         return(ph->ph_hashooks);
 116 }
 117
 118 /* XXX */
 119 #if defined(_KERNEL_OPT)
 120 #include "ipfilter.h"
 121 #endif
 122
 123 #endif /* _NET_PFIL_H_ */