summaryrefslogtreecommitdiffstats
path: root/sys/net/pfil.h
blob: c9a1b65918e5209849b2efeabd4e338932a25df0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
/*	$FreeBSD$ */
/*	$NetBSD: pfil.h,v 1.22 2003/06/23 12:57:08 martin 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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 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/systm.h>
#include <sys/queue.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/lock.h>
#include <sys/rmlock.h>

struct mbuf;
struct ifnet;
struct inpcb;

typedef	int	(*pfil_func_t)(void *, struct mbuf **, struct ifnet *, int,
		    struct inpcb *);

/*
 * The packet filter hooks are designed for anything to call them to
 * possibly intercept the packet.  Multiple filter hooks are chained
 * together and after each other in the specified order.
 */
struct packet_filter_hook {
	TAILQ_ENTRY(packet_filter_hook) pfil_chain;
	pfil_func_t	 pfil_func;
	void		*pfil_arg;
};

#define PFIL_IN		0x00000001
#define PFIL_OUT	0x00000002
#define PFIL_WAITOK	0x00000004
#define PFIL_ALL	(PFIL_IN|PFIL_OUT)

typedef	TAILQ_HEAD(pfil_chain, packet_filter_hook) pfil_chain_t;

#define	PFIL_TYPE_AF		1	/* key is AF_* type */
#define	PFIL_TYPE_IFNET		2	/* key is ifnet pointer */

#define	PFIL_FLAG_PRIVATE_LOCK	0x01	/* Personal lock instead of global */

/*
 * A pfil head is created by each protocol or packet intercept point.
 * For packet is then run through the hook chain for inspection.
 */
struct pfil_head {
	pfil_chain_t	 ph_in;
	pfil_chain_t	 ph_out;
	int		 ph_type;
	int		 ph_nhooks;
#if defined( __linux__ ) || defined( _WIN32 )
	rwlock_t	 ph_mtx;
#else
	struct rmlock	*ph_plock;	/* Pointer to the used lock */
	struct rmlock	 ph_lock;	/* Private lock storage */
	int		 flags;
#endif
	union {
		u_long	 phu_val;
		void	*phu_ptr;
	} ph_un;
#define	ph_af		 ph_un.phu_val
#define	ph_ifnet	 ph_un.phu_ptr
	LIST_ENTRY(pfil_head) ph_list;
};

/* Public functions for pfil hook management by packet filters. */
struct pfil_head *pfil_head_get(int, u_long);
int	pfil_add_hook(pfil_func_t, void *, int, struct pfil_head *);
int	pfil_remove_hook(pfil_func_t, void *, int, struct pfil_head *);
#define	PFIL_HOOKED(p) ((p)->ph_nhooks > 0)

/* Public functions to run the packet inspection by protocols. */
int	pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *,
	    int, struct inpcb *inp);

/* Public functions for pfil head management by protocols. */
int	pfil_head_register(struct pfil_head *);
int	pfil_head_unregister(struct pfil_head *);

/* Public pfil locking functions for self managed locks by packet filters. */
struct rm_priotracker;	/* Do not require including rmlock header */
int	pfil_try_rlock(struct pfil_head *, struct rm_priotracker *);
void	pfil_rlock(struct pfil_head *, struct rm_priotracker *);
void	pfil_runlock(struct pfil_head *, struct rm_priotracker *);
void	pfil_wlock(struct pfil_head *);
void	pfil_wunlock(struct pfil_head *);
int	pfil_wowned(struct pfil_head *ph);

/* Internal pfil locking functions. */
#define	PFIL_LOCK_INIT_REAL(l, t)	\
	rm_init_flags(l, "PFil " t " rmlock", RM_RECURSE)
#define	PFIL_LOCK_DESTROY_REAL(l)	\
	rm_destroy(l)
#define	PFIL_LOCK_INIT(p)	do {			\
	if ((p)->flags & PFIL_FLAG_PRIVATE_LOCK) {	\
		PFIL_LOCK_INIT_REAL(&(p)->ph_lock, "private");	\
		(p)->ph_plock = &(p)->ph_lock;		\
	} else						\
		(p)->ph_plock = &V_pfil_lock;		\
} while (0)
#define	PFIL_LOCK_DESTROY(p)	do {			\
	if ((p)->flags & PFIL_FLAG_PRIVATE_LOCK)	\
		PFIL_LOCK_DESTROY_REAL((p)->ph_plock);	\
} while (0)

#define	PFIL_TRY_RLOCK(p, t)	rm_try_rlock((p)->ph_plock, (t))
#define	PFIL_RLOCK(p, t)	rm_rlock((p)->ph_plock, (t))
#define	PFIL_WLOCK(p)		rm_wlock((p)->ph_plock)
#define	PFIL_RUNLOCK(p, t)	rm_runlock((p)->ph_plock, (t))
#define	PFIL_WUNLOCK(p)		rm_wunlock((p)->ph_plock)
#define	PFIL_WOWNED(p)		rm_wowned((p)->ph_plock)

/* Internal locking macros for global/vnet pfil_head_list. */
#define	PFIL_HEADLIST_LOCK()	mtx_lock(&pfil_global_lock)
#define	PFIL_HEADLIST_UNLOCK()	mtx_unlock(&pfil_global_lock)

#endif /* _NET_PFIL_H_ */
OpenPOWER on IntegriCloud