1237434Skib/*	$FreeBSD$ */
2237434Skib/*	$NetBSD: pfil.h,v 1.22 2003/06/23 12:57:08 martin Exp $	*/
3237434Skib
4237434Skib/*-
5237434Skib * Copyright (c) 1996 Matthew R. Green
6237434Skib * All rights reserved.
7237434Skib *
8237434Skib * Redistribution and use in source and binary forms, with or without
9237434Skib * modification, are permitted provided that the following conditions
10237434Skib * are met:
11237434Skib * 1. Redistributions of source code must retain the above copyright
12237434Skib *    notice, this list of conditions and the following disclaimer.
13237434Skib * 2. Redistributions in binary form must reproduce the above copyright
14237434Skib *    notice, this list of conditions and the following disclaimer in the
15237434Skib *    documentation and/or other materials provided with the distribution.
16237434Skib * 3. The name of the author may not be used to endorse or promote products
17237434Skib *    derived from this software without specific prior written permission.
18237434Skib *
19237434Skib * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20237434Skib * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21237434Skib * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22237434Skib * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23237434Skib * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24237434Skib * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25237434Skib * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26237434Skib * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27237434Skib * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28237434Skib * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29237434Skib * SUCH DAMAGE.
30237434Skib */
31237434Skib
32237434Skib#ifndef _NET_PFIL_H_
33237434Skib#define _NET_PFIL_H_
34237434Skib
35237434Skib#include <sys/systm.h>
36237434Skib#include <sys/queue.h>
37237434Skib#include <sys/_lock.h>
38237434Skib#include <sys/_mutex.h>
39237434Skib#include <sys/lock.h>
40237434Skib#include <sys/rmlock.h>
41237434Skib
42237434Skibstruct mbuf;
43237434Skibstruct ifnet;
44237434Skibstruct inpcb;
45237434Skib
46237434Skibtypedef	int	(*pfil_func_t)(void *, struct mbuf **, struct ifnet *, int,
47237434Skib		    struct inpcb *);
48237434Skib
49237434Skib/*
50237434Skib * The packet filter hooks are designed for anything to call them to
51237434Skib * possibly intercept the packet.  Multiple filter hooks are chained
52237434Skib * together and after each other in the specified order.
53 */
54struct packet_filter_hook {
55	TAILQ_ENTRY(packet_filter_hook) pfil_chain;
56	pfil_func_t	 pfil_func;
57	void		*pfil_arg;
58};
59
60#define PFIL_IN		0x00000001
61#define PFIL_OUT	0x00000002
62#define PFIL_WAITOK	0x00000004
63#define PFIL_ALL	(PFIL_IN|PFIL_OUT)
64
65typedef	TAILQ_HEAD(pfil_chain, packet_filter_hook) pfil_chain_t;
66
67#define	PFIL_TYPE_AF		1	/* key is AF_* type */
68#define	PFIL_TYPE_IFNET		2	/* key is ifnet pointer */
69
70#define	PFIL_FLAG_PRIVATE_LOCK	0x01	/* Personal lock instead of global */
71
72/*
73 * A pfil head is created by each protocol or packet intercept point.
74 * For packet is then run through the hook chain for inspection.
75 */
76struct pfil_head {
77	pfil_chain_t	 ph_in;
78	pfil_chain_t	 ph_out;
79	int		 ph_type;
80	int		 ph_nhooks;
81#if defined( __linux__ ) || defined( _WIN32 )
82	rwlock_t	 ph_mtx;
83#else
84	struct rmlock	*ph_plock;	/* Pointer to the used lock */
85	struct rmlock	 ph_lock;	/* Private lock storage */
86	int		 flags;
87#endif
88	union {
89		u_long	 phu_val;
90		void	*phu_ptr;
91	} ph_un;
92#define	ph_af		 ph_un.phu_val
93#define	ph_ifnet	 ph_un.phu_ptr
94	LIST_ENTRY(pfil_head) ph_list;
95};
96
97/* Public functions for pfil hook management by packet filters. */
98struct pfil_head *pfil_head_get(int, u_long);
99int	pfil_add_hook(pfil_func_t, void *, int, struct pfil_head *);
100int	pfil_remove_hook(pfil_func_t, void *, int, struct pfil_head *);
101#define	PFIL_HOOKED(p) ((p)->ph_nhooks > 0)
102
103/* Public functions to run the packet inspection by protocols. */
104int	pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *,
105	    int, struct inpcb *inp);
106
107/* Public functions for pfil head management by protocols. */
108int	pfil_head_register(struct pfil_head *);
109int	pfil_head_unregister(struct pfil_head *);
110
111/* Public pfil locking functions for self managed locks by packet filters. */
112struct rm_priotracker;	/* Do not require including rmlock header */
113int	pfil_try_rlock(struct pfil_head *, struct rm_priotracker *);
114void	pfil_rlock(struct pfil_head *, struct rm_priotracker *);
115void	pfil_runlock(struct pfil_head *, struct rm_priotracker *);
116void	pfil_wlock(struct pfil_head *);
117void	pfil_wunlock(struct pfil_head *);
118int	pfil_wowned(struct pfil_head *ph);
119
120/* Internal pfil locking functions. */
121#define	PFIL_LOCK_INIT_REAL(l, t)	\
122	rm_init_flags(l, "PFil " t " rmlock", RM_RECURSE)
123#define	PFIL_LOCK_DESTROY_REAL(l)	\
124	rm_destroy(l)
125#define	PFIL_LOCK_INIT(p)	do {			\
126	if ((p)->flags & PFIL_FLAG_PRIVATE_LOCK) {	\
127		PFIL_LOCK_INIT_REAL(&(p)->ph_lock, "private");	\
128		(p)->ph_plock = &(p)->ph_lock;		\
129	} else						\
130		(p)->ph_plock = &V_pfil_lock;		\
131} while (0)
132#define	PFIL_LOCK_DESTROY(p)	do {			\
133	if ((p)->flags & PFIL_FLAG_PRIVATE_LOCK)	\
134		PFIL_LOCK_DESTROY_REAL((p)->ph_plock);	\
135} while (0)
136
137#define	PFIL_TRY_RLOCK(p, t)	rm_try_rlock((p)->ph_plock, (t))
138#define	PFIL_RLOCK(p, t)	rm_rlock((p)->ph_plock, (t))
139#define	PFIL_WLOCK(p)		rm_wlock((p)->ph_plock)
140#define	PFIL_RUNLOCK(p, t)	rm_runlock((p)->ph_plock, (t))
141#define	PFIL_WUNLOCK(p)		rm_wunlock((p)->ph_plock)
142#define	PFIL_WOWNED(p)		rm_wowned((p)->ph_plock)
143
144/* Internal locking macros for global/vnet pfil_head_list. */
145#define	PFIL_HEADLIST_LOCK()	mtx_lock(&pfil_global_lock)
146#define	PFIL_HEADLIST_UNLOCK()	mtx_unlock(&pfil_global_lock)
147
148#endif /* _NET_PFIL_H_ */
149