pfil.h revision 155201 
1/*	$FreeBSD: head/sys/net/pfil.h 155201 2006-02-02 03:13:16Z csjp $ */
2/*	$NetBSD: pfil.h,v 1.22 2003/06/23 12:57:08 martin 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#include <sys/systm.h>
36#include <sys/queue.h>
37#include <sys/_lock.h>
38#include <sys/_mutex.h>
39#include <sys/rwlock.h>
40
41struct mbuf;
42struct ifnet;
43struct inpcb;
44
45/*
46 * The packet filter hooks are designed for anything to call them to
47 * possibly intercept the packet.
48 */
49struct packet_filter_hook {
50        TAILQ_ENTRY(packet_filter_hook) pfil_link;
51	int	(*pfil_func)(void *, struct mbuf **, struct ifnet *, int, struct inpcb *);
52	void	*pfil_arg;
53	int	pfil_flags;
54};
55
56#define PFIL_IN		0x00000001
57#define PFIL_OUT	0x00000002
58#define PFIL_WAITOK	0x00000004
59#define PFIL_ALL	(PFIL_IN|PFIL_OUT)
60
61typedef	TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t;
62
63#define	PFIL_TYPE_AF		1	/* key is AF_* type */
64#define	PFIL_TYPE_IFNET		2	/* key is ifnet pointer */
65
66struct pfil_head {
67	pfil_list_t	ph_in;
68	pfil_list_t	ph_out;
69	int		ph_type;
70	int		ph_nhooks;
71	struct rwlock	ph_mtx;
72	union {
73		u_long		phu_val;
74		void		*phu_ptr;
75	} ph_un;
76#define	ph_af		ph_un.phu_val
77#define	ph_ifnet	ph_un.phu_ptr
78	LIST_ENTRY(pfil_head) ph_list;
79};
80
81int	pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *,
82	    int, struct inpcb *inp);
83
84int	pfil_add_hook(int (*func)(void *, struct mbuf **,
85	    struct ifnet *, int, struct inpcb *), void *, int, struct pfil_head *);
86int	pfil_remove_hook(int (*func)(void *, struct mbuf **,
87	    struct ifnet *, int, struct inpcb *), void *, int, struct pfil_head *);
88
89int	pfil_head_register(struct pfil_head *);
90int	pfil_head_unregister(struct pfil_head *);
91
92struct pfil_head *pfil_head_get(int, u_long);
93
94#define	PFIL_HOOKED(p) (&(p)->ph_nhooks > 0)
95#define PFIL_RLOCK(p) rw_rlock(&(p)->ph_mtx)
96#define PFIL_WLOCK(p) rw_wlock(&(p)->ph_mtx)
97#define PFIL_RUNLOCK(p) rw_runlock(&(p)->ph_mtx)
98#define PFIL_WUNLOCK(p) rw_wunlock(&(p)->ph_mtx)
99#define PFIL_LIST_LOCK() mtx_lock(&pfil_global_lock)
100#define PFIL_LIST_UNLOCK() mtx_unlock(&pfil_global_lock)
101
102static __inline struct packet_filter_hook *
103pfil_hook_get(int dir, struct pfil_head *ph)
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
110		return (NULL);
111}
112
113#endif /* _NET_PFIL_H_ */
114