1/*	$FreeBSD$ */
2/*	$NetBSD: pfil.h,v 1.22 2003/06/23 12:57:08 martin Exp $	*/
3
4/*-
5 * SPDX-License-Identifier: BSD-3-Clause
6 *
7 * Copyright (c) 1996 Matthew R. Green
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef _NET_PFIL_H_
35#define _NET_PFIL_H_
36
37#include <sys/systm.h>
38#include <sys/queue.h>
39#include <sys/_lock.h>
40#include <sys/_mutex.h>
41#include <sys/lock.h>
42#include <sys/rmlock.h>
43#include <net/vnet.h>
44
45struct mbuf;
46struct ifnet;
47struct inpcb;
48
49typedef	int	(*pfil_func_t)(void *, struct mbuf **, struct ifnet *, int,
50		    struct inpcb *);
51typedef	int	(*pfil_func_flags_t)(void *, struct mbuf **, struct ifnet *,
52		    int, int, struct inpcb *);
53
54/*
55 * The packet filter hooks are designed for anything to call them to
56 * possibly intercept the packet.  Multiple filter hooks are chained
57 * together and after each other in the specified order.
58 */
59struct packet_filter_hook {
60	TAILQ_ENTRY(packet_filter_hook) pfil_chain;
61	pfil_func_t		 pfil_func;
62	pfil_func_flags_t	 pfil_func_flags;
63	void			*pfil_arg;
64};
65
66#define PFIL_IN		0x00000001
67#define PFIL_OUT	0x00000002
68#define PFIL_WAITOK	0x00000004
69#define PFIL_FWD	0x00000008
70#define PFIL_ALL	(PFIL_IN|PFIL_OUT)
71
72typedef	TAILQ_HEAD(pfil_chain, packet_filter_hook) pfil_chain_t;
73
74#define	PFIL_TYPE_AF		1	/* key is AF_* type */
75#define	PFIL_TYPE_IFNET		2	/* key is ifnet pointer */
76
77#define	PFIL_FLAG_PRIVATE_LOCK	0x01	/* Personal lock instead of global */
78
79/*
80 * A pfil head is created by each protocol or packet intercept point.
81 * For packet is then run through the hook chain for inspection.
82 */
83struct pfil_head {
84	pfil_chain_t	 ph_in;
85	pfil_chain_t	 ph_out;
86	int		 ph_type;
87	int		 ph_nhooks;
88#if defined( __linux__ ) || defined( _WIN32 )
89	rwlock_t	 ph_mtx;
90#else
91	struct rmlock	*ph_plock;	/* Pointer to the used lock */
92	struct rmlock	 ph_lock;	/* Private lock storage */
93	int		 flags;
94#endif
95	union {
96		u_long	 phu_val;
97		void	*phu_ptr;
98	} ph_un;
99#define	ph_af		 ph_un.phu_val
100#define	ph_ifnet	 ph_un.phu_ptr
101	LIST_ENTRY(pfil_head) ph_list;
102};
103
104VNET_DECLARE(struct rmlock, pfil_lock);
105#define	V_pfil_lock	VNET(pfil_lock)
106
107/* Public functions for pfil hook management by packet filters. */
108struct pfil_head *pfil_head_get(int, u_long);
109int	pfil_add_hook_flags(pfil_func_flags_t, void *, int, struct pfil_head *);
110int	pfil_add_hook(pfil_func_t, void *, int, struct pfil_head *);
111int	pfil_remove_hook_flags(pfil_func_flags_t, void *, int, struct pfil_head *);
112int	pfil_remove_hook(pfil_func_t, void *, int, struct pfil_head *);
113#define	PFIL_HOOKED(p) ((p)->ph_nhooks > 0)
114
115/* Public functions to run the packet inspection by protocols. */
116int	pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *, int,
117    int, struct inpcb *inp);
118
119/* Public functions for pfil head management by protocols. */
120int	pfil_head_register(struct pfil_head *);
121int	pfil_head_unregister(struct pfil_head *);
122
123/* Public pfil locking functions for self managed locks by packet filters. */
124int	pfil_try_rlock(struct pfil_head *, struct rm_priotracker *);
125void	pfil_rlock(struct pfil_head *, struct rm_priotracker *);
126void	pfil_runlock(struct pfil_head *, struct rm_priotracker *);
127void	pfil_wlock(struct pfil_head *);
128void	pfil_wunlock(struct pfil_head *);
129int	pfil_wowned(struct pfil_head *ph);
130
131#endif /* _NET_PFIL_H_ */
132