FreeBSD/Linux Kernel Cross Reference
sys/net/pfil.h
1 /* $FreeBSD: src/sys/net/pfil.h,v 1.11.2.2 2005/01/31 23:26:23 imp Exp $ */
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/condvar.h> /* XXX */
40
41 struct mbuf;
42 struct ifnet;
43 struct inpcb;
44
45 /*
46 * The packet filter hooks are designed for anything to call them to
47 * possibly intercept the packet.
48 */
49 struct packet_filter_hook {
50 TAILQ_ENTRY(packet_filter_hook) pfil_link;
51 int (*pfil_func)(void *, struct mbuf **, struct ifnet *, int, struct inpcb *);
52 void *pfil_arg;
53 int pfil_flags;
54 };
55
56 #define PFIL_IN 0x00000001
57 #define PFIL_OUT 0x00000002
58 #define PFIL_WAITOK 0x00000004
59 #define PFIL_ALL (PFIL_IN|PFIL_OUT)
60
61 typedef TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t;
62
63 #define PFIL_TYPE_AF 1 /* key is AF_* type */
64 #define PFIL_TYPE_IFNET 2 /* key is ifnet pointer */
65
66 struct pfil_head {
67 pfil_list_t ph_in;
68 pfil_list_t ph_out;
69 int ph_type;
70 /*
71 * Locking: use a busycounter per pfil_head.
72 * Use ph_busy_count = -1 to indicate pfil_head is empty.
73 */
74 int ph_busy_count; /* count of threads with read lock */
75 int ph_want_write; /* want write lock flag */
76 struct cv ph_cv; /* for waking up writers */
77 struct mtx ph_mtx; /* mutex on locking state */
78 union {
79 u_long phu_val;
80 void *phu_ptr;
81 } ph_un;
82 #define ph_af ph_un.phu_val
83 #define ph_ifnet ph_un.phu_ptr
84 LIST_ENTRY(pfil_head) ph_list;
85 };
86
87 int pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *,
88 int, struct inpcb *inp);
89
90 int pfil_add_hook(int (*func)(void *, struct mbuf **,
91 struct ifnet *, int, struct inpcb *), void *, int, struct pfil_head *);
92 int pfil_remove_hook(int (*func)(void *, struct mbuf **,
93 struct ifnet *, int, struct inpcb *), void *, int, struct pfil_head *);
94
95 int pfil_head_register(struct pfil_head *);
96 int pfil_head_unregister(struct pfil_head *);
97
98 struct pfil_head *pfil_head_get(int, u_long);
99
100 static __inline struct packet_filter_hook *
101 pfil_hook_get(int dir, struct pfil_head *ph)
102 {
103 KASSERT(ph->ph_busy_count > 0,
104 ("pfil_hook_get: called on unbusy pfil_head"));
105 if (dir == PFIL_IN)
106 return (TAILQ_FIRST(&ph->ph_in));
107 else if (dir == PFIL_OUT)
108 return (TAILQ_FIRST(&ph->ph_out));
109 else
110 return (NULL);
111 }
112
113 #endif /* _NET_PFIL_H_ */
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