xref: /freebsd/sys/net/pfil.h (revision f0cfa1b168014f56c02b83e5f28412cc5f78d117)
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 
45 struct mbuf;
46 struct ifnet;
47 struct inpcb;
48 
49 typedef	int	(*pfil_func_t)(void *, struct mbuf **, struct ifnet *, int,
50 		    struct inpcb *);
51 
52 /*
53  * The packet filter hooks are designed for anything to call them to
54  * possibly intercept the packet.  Multiple filter hooks are chained
55  * together and after each other in the specified order.
56  */
57 struct packet_filter_hook {
58 	TAILQ_ENTRY(packet_filter_hook) pfil_chain;
59 	pfil_func_t	 pfil_func;
60 	void		*pfil_arg;
61 };
62 
63 #define PFIL_IN		0x00000001
64 #define PFIL_OUT	0x00000002
65 #define PFIL_WAITOK	0x00000004
66 #define PFIL_ALL	(PFIL_IN|PFIL_OUT)
67 
68 typedef	TAILQ_HEAD(pfil_chain, packet_filter_hook) pfil_chain_t;
69 
70 #define	PFIL_TYPE_AF		1	/* key is AF_* type */
71 #define	PFIL_TYPE_IFNET		2	/* key is ifnet pointer */
72 
73 #define	PFIL_FLAG_PRIVATE_LOCK	0x01	/* Personal lock instead of global */
74 
75 /*
76  * A pfil head is created by each protocol or packet intercept point.
77  * For packet is then run through the hook chain for inspection.
78  */
79 struct pfil_head {
80 	pfil_chain_t	 ph_in;
81 	pfil_chain_t	 ph_out;
82 	int		 ph_type;
83 	int		 ph_nhooks;
84 #if defined( __linux__ ) || defined( _WIN32 )
85 	rwlock_t	 ph_mtx;
86 #else
87 	struct rmlock	*ph_plock;	/* Pointer to the used lock */
88 	struct rmlock	 ph_lock;	/* Private lock storage */
89 	int		 flags;
90 #endif
91 	union {
92 		u_long	 phu_val;
93 		void	*phu_ptr;
94 	} ph_un;
95 #define	ph_af		 ph_un.phu_val
96 #define	ph_ifnet	 ph_un.phu_ptr
97 	LIST_ENTRY(pfil_head) ph_list;
98 };
99 
100 VNET_DECLARE(struct rmlock, pfil_lock);
101 #define	V_pfil_lock	VNET(pfil_lock)
102 
103 /* Public functions for pfil hook management by packet filters. */
104 struct pfil_head *pfil_head_get(int, u_long);
105 int	pfil_add_hook(pfil_func_t, void *, int, struct pfil_head *);
106 int	pfil_remove_hook(pfil_func_t, void *, int, struct pfil_head *);
107 #define	PFIL_HOOKED(p) ((p)->ph_nhooks > 0)
108 
109 /* Public functions to run the packet inspection by protocols. */
110 int	pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *,
111 	    int, struct inpcb *inp);
112 
113 /* Public functions for pfil head management by protocols. */
114 int	pfil_head_register(struct pfil_head *);
115 int	pfil_head_unregister(struct pfil_head *);
116 
117 /* Public pfil locking functions for self managed locks by packet filters. */
118 int	pfil_try_rlock(struct pfil_head *, struct rm_priotracker *);
119 void	pfil_rlock(struct pfil_head *, struct rm_priotracker *);
120 void	pfil_runlock(struct pfil_head *, struct rm_priotracker *);
121 void	pfil_wlock(struct pfil_head *);
122 void	pfil_wunlock(struct pfil_head *);
123 int	pfil_wowned(struct pfil_head *ph);
124 
125 #endif /* _NET_PFIL_H_ */
126