pfil.h revision 317042 
1/*	$FreeBSD: stable/11/sys/net/pfil.h 317042 2017-04-17 09:34:09Z ae $ */
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/lock.h>
40#include <sys/rmlock.h>
41#include <net/vnet.h>
42
43struct mbuf;
44struct ifnet;
45struct inpcb;
46
47typedef	int	(*pfil_func_t)(void *, struct mbuf **, struct ifnet *, int,
48		    struct inpcb *);
49
50/*
51 * The packet filter hooks are designed for anything to call them to
52 * possibly intercept the packet.  Multiple filter hooks are chained
53 * together and after each other in the specified order.
54 */
55struct packet_filter_hook {
56	TAILQ_ENTRY(packet_filter_hook) pfil_chain;
57	pfil_func_t	 pfil_func;
58	void		*pfil_arg;
59};
60
61#define PFIL_IN		0x00000001
62#define PFIL_OUT	0x00000002
63#define PFIL_WAITOK	0x00000004
64#define PFIL_ALL	(PFIL_IN|PFIL_OUT)
65
66typedef	TAILQ_HEAD(pfil_chain, packet_filter_hook) pfil_chain_t;
67
68#define	PFIL_TYPE_AF		1	/* key is AF_* type */
69#define	PFIL_TYPE_IFNET		2	/* key is ifnet pointer */
70
71#define	PFIL_FLAG_PRIVATE_LOCK	0x01	/* Personal lock instead of global */
72
73/*
74 * A pfil head is created by each protocol or packet intercept point.
75 * For packet is then run through the hook chain for inspection.
76 */
77struct pfil_head {
78	pfil_chain_t	 ph_in;
79	pfil_chain_t	 ph_out;
80	int		 ph_type;
81	int		 ph_nhooks;
82#if defined( __linux__ ) || defined( _WIN32 )
83	rwlock_t	 ph_mtx;
84#else
85	struct rmlock	*ph_plock;	/* Pointer to the used lock */
86	struct rmlock	 ph_lock;	/* Private lock storage */
87	int		 flags;
88#endif
89	union {
90		u_long	 phu_val;
91		void	*phu_ptr;
92	} ph_un;
93#define	ph_af		 ph_un.phu_val
94#define	ph_ifnet	 ph_un.phu_ptr
95	LIST_ENTRY(pfil_head) ph_list;
96};
97
98VNET_DECLARE(struct rmlock, pfil_lock);
99#define	V_pfil_lock	VNET(pfil_lock)
100
101/* Public functions for pfil hook management by packet filters. */
102struct pfil_head *pfil_head_get(int, u_long);
103int	pfil_add_hook(pfil_func_t, void *, int, struct pfil_head *);
104int	pfil_remove_hook(pfil_func_t, void *, int, struct pfil_head *);
105#define	PFIL_HOOKED(p) ((p)->ph_nhooks > 0)
106
107/* Public functions to run the packet inspection by protocols. */
108int	pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *,
109	    int, struct inpcb *inp);
110
111/* Public functions for pfil head management by protocols. */
112int	pfil_head_register(struct pfil_head *);
113int	pfil_head_unregister(struct pfil_head *);
114
115/* Public pfil locking functions for self managed locks by packet filters. */
116int	pfil_try_rlock(struct pfil_head *, struct rm_priotracker *);
117void	pfil_rlock(struct pfil_head *, struct rm_priotracker *);
118void	pfil_runlock(struct pfil_head *, struct rm_priotracker *);
119void	pfil_wlock(struct pfil_head *);
120void	pfil_wunlock(struct pfil_head *);
121int	pfil_wowned(struct pfil_head *ph);
122
123#endif /* _NET_PFIL_H_ */
124