text: /*	$NetBSD: pfil.h,v 1.31 2013/06/29 21:06:58 rmind Exp $	*/
  
  /*
   * Copyright (c) 1996 Matthew R. Green
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  #ifndef _NET_PFIL_H_
  #define _NET_PFIL_H_
  
  #include <sys/queue.h>
  
  struct mbuf;
  struct ifnet;
  
  /*
   * The packet filter hooks are designed for anything to call them to
   * possibly intercept the packet.
   */
  typedef int (*pfil_func_t)(void *, struct mbuf **, struct ifnet *, int);
  
  #define PFIL_IN		0x00000001
  #define PFIL_OUT	0x00000002
  #define PFIL_ALL	(PFIL_IN|PFIL_OUT)
  #define PFIL_IFADDR	0x00000008
  #define PFIL_IFNET	0x00000010
  
  /* events notified by PFIL_IFNET */
  #define	PFIL_IFNET_ATTACH	0
  #define	PFIL_IFNET_DETACH	1
  
  #define	PFIL_TYPE_AF		1	/* key is AF_* type */
  #define	PFIL_TYPE_IFNET		2	/* key is ifnet pointer */
  
  typedef struct pfil_head	pfil_head_t;
  
  #ifdef _KERNEL
  
  int	pfil_run_hooks(pfil_head_t *, struct mbuf **, struct ifnet *, int);
  int	pfil_add_hook(pfil_func_t, void *, int, pfil_head_t *);
  int	pfil_remove_hook(pfil_func_t, void *, int, pfil_head_t *);
  
  pfil_head_t *	pfil_head_create(int, void *);
  void		pfil_head_destroy(pfil_head_t *);
  pfil_head_t *	pfil_head_get(int, void *);
  
  /* Packet filtering hook for interfaces (in sys/net/if.c module). */
  extern pfil_head_t *if_pfil;
  
  #endif /* _KERNEL */
  
  #endif /* !_NET_PFIL_H_ */
  