pfil_get_hook() is gone
[dragonfly.git] / sys / net / pfil.c
CommitLineData
9e99d0a2 1/* $NetBSD: pfil.c,v 1.20 2001/11/12 23:49:46 lukem Exp $ */
7f8565be 2/* $DragonFly: src/sys/net/pfil.c,v 1.8 2008/09/14 04:34:26 sephe Exp $ */
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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#include <sys/param.h>
33#include <sys/errno.h>
34#include <sys/malloc.h>
35#include <sys/socket.h>
36#include <sys/socketvar.h>
37#include <sys/systm.h>
38#include <sys/proc.h>
39#include <sys/queue.h>
40
41#include <net/if.h>
42#include <net/pfil.h>
43
afabe90c 44static int pfil_list_add(struct pfil_head *,
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45 int (*)(void *, struct mbuf **, struct ifnet *, int), void *, int);
46
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47static int pfil_list_remove(struct pfil_head *,
48 int (*)(void *, struct mbuf **, struct ifnet *, int), void *, int);
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49
50LIST_HEAD(, pfil_head) pfil_head_list =
51 LIST_HEAD_INITIALIZER(&pfil_head_list);
52
53/*
54 * pfil_run_hooks() runs the specified packet filter hooks.
55 */
56int
57pfil_run_hooks(struct pfil_head *ph, struct mbuf **mp, struct ifnet *ifp,
58 int dir)
59{
60 struct packet_filter_hook *pfh;
61 struct mbuf *m = *mp;
7f8565be 62 pfil_list_t *list;
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63 int rv = 0;
64
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65 if (dir == PFIL_IN)
66 list = &ph->ph_in;
67 else if (dir == PFIL_OUT)
68 list = &ph->ph_out;
69 else
70 return 0; /* XXX panic? */
71
72 TAILQ_FOREACH(pfh, list, pfil_link) {
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73 if (pfh->pfil_func != NULL) {
74 rv = (*pfh->pfil_func)(pfh->pfil_arg, &m, ifp, dir);
75 if (rv != 0 || m == NULL)
76 break;
77 }
78 }
79
80 *mp = m;
81 return (rv);
82}
83
84/*
85 * pfil_head_register() registers a pfil_head with the packet filter
86 * hook mechanism.
87 */
88int
89pfil_head_register(struct pfil_head *ph)
90{
91 struct pfil_head *lph;
92
94171836 93 LIST_FOREACH(lph, &pfil_head_list, ph_list) {
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94 if (ph->ph_type == lph->ph_type &&
95 ph->ph_un.phu_val == lph->ph_un.phu_val)
96 return EEXIST;
97 }
98
99 TAILQ_INIT(&ph->ph_in);
100 TAILQ_INIT(&ph->ph_out);
afabe90c 101 ph->ph_hashooks = 0;
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102
103 LIST_INSERT_HEAD(&pfil_head_list, ph, ph_list);
104
105 return (0);
106}
107
108/*
109 * pfil_head_unregister() removes a pfil_head from the packet filter
110 * hook mechanism.
111 */
112int
113pfil_head_unregister(struct pfil_head *pfh)
114{
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115 LIST_REMOVE(pfh, ph_list);
116 return (0);
117}
118
119/*
120 * pfil_head_get() returns the pfil_head for a given key/dlt.
121 */
122struct pfil_head *
123pfil_head_get(int type, u_long val)
124{
125 struct pfil_head *ph;
126
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127 LIST_FOREACH(ph, &pfil_head_list, ph_list) {
128 if (ph->ph_type == type && ph->ph_un.phu_val == val)
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129 break;
130 }
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131 return (ph);
132}
133
134/*
135 * pfil_add_hook() adds a function to the packet filter hook. the
136 * flags are:
137 * PFIL_IN call me on incoming packets
138 * PFIL_OUT call me on outgoing packets
139 * PFIL_ALL call me on all of the above
702cc4db 140 * PFIL_WAITOK OK to call kmalloc with M_WAITOK.
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141 */
142int
143pfil_add_hook(int (*func)(void *, struct mbuf **, struct ifnet *, int),
144 void *arg, int flags, struct pfil_head *ph)
145{
146 int err = 0;
147
148 if (flags & PFIL_IN) {
afabe90c 149 err = pfil_list_add(ph, func, arg, flags & ~PFIL_OUT);
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150 if (err)
151 return err;
152 }
153 if (flags & PFIL_OUT) {
afabe90c 154 err = pfil_list_add(ph, func, arg, flags & ~PFIL_IN);
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155 if (err) {
156 if (flags & PFIL_IN)
afabe90c 157 pfil_list_remove(ph, func, arg, PFIL_IN);
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158 return err;
159 }
160 }
161 return 0;
162}
163
164static int
afabe90c 165pfil_list_add(struct pfil_head *ph,
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166 int (*func)(void *, struct mbuf **, struct ifnet *, int), void *arg,
167 int flags)
168{
169 struct packet_filter_hook *pfh;
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170 pfil_list_t *list;
171
172 list = (flags & PFIL_IN) ? &ph->ph_in : &ph->ph_out;
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173
174 /*
175 * First make sure the hook is not already there.
176 */
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177 TAILQ_FOREACH(pfh, list, pfil_link) {
178 if (pfh->pfil_func == func && pfh->pfil_arg == arg)
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179 return EEXIST;
180 }
181
efda3bd0 182 pfh = (struct packet_filter_hook *)kmalloc(sizeof(*pfh), M_IFADDR,
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183 (flags & PFIL_WAITOK) ? M_WAITOK : M_NOWAIT);
184 if (pfh == NULL)
185 return ENOMEM;
186
187 pfh->pfil_func = func;
188 pfh->pfil_arg = arg;
189
190 /*
191 * insert the input list in reverse order of the output list
192 * so that the same path is followed in or out of the kernel.
193 */
194 if (flags & PFIL_IN)
195 TAILQ_INSERT_HEAD(list, pfh, pfil_link);
196 else
197 TAILQ_INSERT_TAIL(list, pfh, pfil_link);
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198 ph->ph_hashooks = 1;
199 return (0);
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200}
201
202/*
203 * pfil_remove_hook removes a specific function from the packet filter
204 * hook list.
205 */
206int
207pfil_remove_hook(int (*func)(void *, struct mbuf **, struct ifnet *, int),
208 void *arg, int flags, struct pfil_head *ph)
209{
210 int err = 0;
211
212 if (flags & PFIL_IN)
afabe90c 213 err = pfil_list_remove(ph, func, arg, PFIL_IN);
9e99d0a2 214 if ((err == 0) && (flags & PFIL_OUT))
afabe90c 215 err = pfil_list_remove(ph, func, arg, PFIL_OUT);
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216 return err;
217}
218
219/*
220 * pfil_list_remove is an internal function that takes a function off the
afabe90c 221 * specified list. Clear ph_hashooks if no functions remain on any list.
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222 */
223static int
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224pfil_list_remove(struct pfil_head *ph,
225 int (*func)(void *, struct mbuf **, struct ifnet *, int), void *arg,
226 int flags)
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227{
228 struct packet_filter_hook *pfh;
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229 pfil_list_t *list;
230
231 list = (flags & PFIL_IN) ? &ph->ph_in : &ph->ph_out;
9e99d0a2 232
94171836 233 TAILQ_FOREACH(pfh, list, pfil_link) {
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234 if (pfh->pfil_func == func && pfh->pfil_arg == arg) {
235 TAILQ_REMOVE(list, pfh, pfil_link);
efda3bd0 236 kfree(pfh, M_IFADDR);
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237 if (TAILQ_EMPTY(&ph->ph_in) && TAILQ_EMPTY(&ph->ph_out))
238 ph->ph_hashooks = 0;
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239 return 0;
240 }
241 }
242 return ENOENT;
243}