1 /* $NetBSD: pfil.c,v 1.20 2001/11/12 23:49:46 lukem Exp $ */
2 /* $DragonFly: src/sys/net/pfil.c,v 1.1 2003/12/02 09:18:17 asmodai Exp $ */
5 * Copyright (c) 1996 Matthew R. Green
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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.
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
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>
39 #include <sys/queue.h>
44 static int pfil_list_add(pfil_list_t *,
45 int (*)(void *, struct mbuf **, struct ifnet *, int), void *, int);
47 static int pfil_list_remove(pfil_list_t *,
48 int (*)(void *, struct mbuf **, struct ifnet *, int), void *);
50 LIST_HEAD(, pfil_head) pfil_head_list =
51 LIST_HEAD_INITIALIZER(&pfil_head_list);
54 * pfil_run_hooks() runs the specified packet filter hooks.
57 pfil_run_hooks(struct pfil_head *ph, struct mbuf **mp, struct ifnet *ifp,
60 struct packet_filter_hook *pfh;
64 for (pfh = pfil_hook_get(dir, ph); pfh != NULL;
65 pfh = TAILQ_NEXT(pfh, pfil_link)) {
66 if (pfh->pfil_func != NULL) {
67 rv = (*pfh->pfil_func)(pfh->pfil_arg, &m, ifp, dir);
68 if (rv != 0 || m == NULL)
78 * pfil_head_register() registers a pfil_head with the packet filter
82 pfil_head_register(struct pfil_head *ph)
84 struct pfil_head *lph;
86 for (lph = LIST_FIRST(&pfil_head_list); lph != NULL;
87 lph = LIST_NEXT(lph, ph_list)) {
88 if (ph->ph_type == lph->ph_type &&
89 ph->ph_un.phu_val == lph->ph_un.phu_val)
93 TAILQ_INIT(&ph->ph_in);
94 TAILQ_INIT(&ph->ph_out);
96 LIST_INSERT_HEAD(&pfil_head_list, ph, ph_list);
102 * pfil_head_unregister() removes a pfil_head from the packet filter
106 pfil_head_unregister(struct pfil_head *pfh)
109 LIST_REMOVE(pfh, ph_list);
114 * pfil_head_get() returns the pfil_head for a given key/dlt.
117 pfil_head_get(int type, u_long val)
119 struct pfil_head *ph;
121 for (ph = LIST_FIRST(&pfil_head_list); ph != NULL;
122 ph = LIST_NEXT(ph, ph_list)) {
123 if (ph->ph_type == type &&
124 ph->ph_un.phu_val == val)
132 * pfil_add_hook() adds a function to the packet filter hook. the
134 * PFIL_IN call me on incoming packets
135 * PFIL_OUT call me on outgoing packets
136 * PFIL_ALL call me on all of the above
137 * PFIL_WAITOK OK to call malloc with M_WAITOK.
140 pfil_add_hook(int (*func)(void *, struct mbuf **, struct ifnet *, int),
141 void *arg, int flags, struct pfil_head *ph)
145 if (flags & PFIL_IN) {
146 err = pfil_list_add(&ph->ph_in, func, arg, flags & ~PFIL_OUT);
150 if (flags & PFIL_OUT) {
151 err = pfil_list_add(&ph->ph_out, func, arg, flags & ~PFIL_IN);
154 pfil_list_remove(&ph->ph_in, func, arg);
162 pfil_list_add(pfil_list_t *list,
163 int (*func)(void *, struct mbuf **, struct ifnet *, int), void *arg,
166 struct packet_filter_hook *pfh;
169 * First make sure the hook is not already there.
171 for (pfh = TAILQ_FIRST(list); pfh != NULL;
172 pfh = TAILQ_NEXT(pfh, pfil_link)) {
173 if (pfh->pfil_func == func &&
174 pfh->pfil_arg == arg)
178 pfh = (struct packet_filter_hook *)malloc(sizeof(*pfh), M_IFADDR,
179 (flags & PFIL_WAITOK) ? M_WAITOK : M_NOWAIT);
183 pfh->pfil_func = func;
187 * insert the input list in reverse order of the output list
188 * so that the same path is followed in or out of the kernel.
191 TAILQ_INSERT_HEAD(list, pfh, pfil_link);
193 TAILQ_INSERT_TAIL(list, pfh, pfil_link);
199 * pfil_remove_hook removes a specific function from the packet filter
203 pfil_remove_hook(int (*func)(void *, struct mbuf **, struct ifnet *, int),
204 void *arg, int flags, struct pfil_head *ph)
209 err = pfil_list_remove(&ph->ph_in, func, arg);
210 if ((err == 0) && (flags & PFIL_OUT))
211 err = pfil_list_remove(&ph->ph_out, func, arg);
216 * pfil_list_remove is an internal function that takes a function off the
220 pfil_list_remove(pfil_list_t *list,
221 int (*func)(void *, struct mbuf **, struct ifnet *, int), void *arg)
223 struct packet_filter_hook *pfh;
225 for (pfh = TAILQ_FIRST(list); pfh != NULL;
226 pfh = TAILQ_NEXT(pfh, pfil_link)) {
227 if (pfh->pfil_func == func && pfh->pfil_arg == arg) {
228 TAILQ_REMOVE(list, pfh, pfil_link);