1 /* $NetBSD: pfil.c,v 1.20 2001/11/12 23:49:46 lukem Exp $ */
2 /* $DragonFly: src/sys/net/pfil.c,v 1.10 2008/09/14 08:58:55 sephe 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>
43 #include <net/netmsg2.h>
45 #define PFIL_CFGPORT cpu_portfn(0)
48 struct netmsg pfil_nmsg;
49 pfil_func_t pfil_func;
52 struct pfil_head *pfil_ph;
55 static int pfil_list_add(struct pfil_head *, pfil_func_t, void *, int);
56 static int pfil_list_remove(struct pfil_head *, pfil_func_t, void *, int);
58 LIST_HEAD(, pfil_head) pfil_head_list =
59 LIST_HEAD_INITIALIZER(&pfil_head_list);
62 * pfil_run_hooks() runs the specified packet filter hooks.
65 pfil_run_hooks(struct pfil_head *ph, struct mbuf **mp, struct ifnet *ifp,
68 struct packet_filter_hook *pfh;
75 else if (dir == PFIL_OUT)
78 return 0; /* XXX panic? */
80 TAILQ_FOREACH(pfh, list, pfil_link) {
81 if (pfh->pfil_func != NULL) {
82 rv = (*pfh->pfil_func)(pfh->pfil_arg, &m, ifp, dir);
83 if (rv != 0 || m == NULL)
93 * pfil_head_register() registers a pfil_head with the packet filter
97 pfil_head_register(struct pfil_head *ph)
99 struct pfil_head *lph;
101 LIST_FOREACH(lph, &pfil_head_list, ph_list) {
102 if (ph->ph_type == lph->ph_type &&
103 ph->ph_un.phu_val == lph->ph_un.phu_val)
107 TAILQ_INIT(&ph->ph_in);
108 TAILQ_INIT(&ph->ph_out);
111 LIST_INSERT_HEAD(&pfil_head_list, ph, ph_list);
117 * pfil_head_unregister() removes a pfil_head from the packet filter
121 pfil_head_unregister(struct pfil_head *pfh)
123 LIST_REMOVE(pfh, ph_list);
128 * pfil_head_get() returns the pfil_head for a given key/dlt.
131 pfil_head_get(int type, u_long val)
133 struct pfil_head *ph;
135 LIST_FOREACH(ph, &pfil_head_list, ph_list) {
136 if (ph->ph_type == type && ph->ph_un.phu_val == val)
143 pfil_add_hook_dispatch(struct netmsg *nmsg)
145 struct netmsg_pfil *pfilmsg = (struct netmsg_pfil *)nmsg;
146 pfil_func_t func = pfilmsg->pfil_func;
147 void *arg = pfilmsg->pfil_arg;
148 int flags = pfilmsg->pfil_flags;
149 struct pfil_head *ph = pfilmsg->pfil_ph;
152 if (flags & PFIL_IN) {
153 err = pfil_list_add(ph, func, arg, flags & ~PFIL_OUT);
157 if (flags & PFIL_OUT) {
158 err = pfil_list_add(ph, func, arg, flags & ~PFIL_IN);
161 pfil_list_remove(ph, func, arg, PFIL_IN);
165 lwkt_replymsg(&nmsg->nm_lmsg, err);
169 * pfil_add_hook() adds a function to the packet filter hook. the
171 * PFIL_IN call me on incoming packets
172 * PFIL_OUT call me on outgoing packets
173 * PFIL_ALL call me on all of the above
174 * PFIL_WAITOK OK to call kmalloc with M_WAITOK.
177 pfil_add_hook(pfil_func_t func, void *arg, int flags, struct pfil_head *ph)
179 struct netmsg_pfil pfilmsg;
182 nmsg = &pfilmsg.pfil_nmsg;
183 netmsg_init(nmsg, &curthread->td_msgport, 0, pfil_add_hook_dispatch);
184 pfilmsg.pfil_func = func;
185 pfilmsg.pfil_arg = arg;
186 pfilmsg.pfil_flags = flags;
187 pfilmsg.pfil_ph = ph;
189 return lwkt_domsg(PFIL_CFGPORT, &nmsg->nm_lmsg, 0);
193 pfil_list_add(struct pfil_head *ph, pfil_func_t func, void *arg, int flags)
195 struct packet_filter_hook *pfh;
198 KKASSERT(&curthread->td_msgport == PFIL_CFGPORT);
200 list = (flags & PFIL_IN) ? &ph->ph_in : &ph->ph_out;
203 * First make sure the hook is not already there.
205 TAILQ_FOREACH(pfh, list, pfil_link) {
206 if (pfh->pfil_func == func && pfh->pfil_arg == arg)
210 pfh = (struct packet_filter_hook *)kmalloc(sizeof(*pfh), M_IFADDR,
211 (flags & PFIL_WAITOK) ? M_WAITOK : M_NOWAIT);
215 pfh->pfil_func = func;
219 * insert the input list in reverse order of the output list
220 * so that the same path is followed in or out of the kernel.
223 TAILQ_INSERT_HEAD(list, pfh, pfil_link);
225 TAILQ_INSERT_TAIL(list, pfh, pfil_link);
231 pfil_remove_hook_dispatch(struct netmsg *nmsg)
233 struct netmsg_pfil *pfilmsg = (struct netmsg_pfil *)nmsg;
234 pfil_func_t func = pfilmsg->pfil_func;
235 void *arg = pfilmsg->pfil_arg;
236 int flags = pfilmsg->pfil_flags;
237 struct pfil_head *ph = pfilmsg->pfil_ph;
241 err = pfil_list_remove(ph, func, arg, PFIL_IN);
242 if ((err == 0) && (flags & PFIL_OUT))
243 err = pfil_list_remove(ph, func, arg, PFIL_OUT);
244 lwkt_replymsg(&nmsg->nm_lmsg, err);
248 * pfil_remove_hook removes a specific function from the packet filter
252 pfil_remove_hook(pfil_func_t func, void *arg, int flags, struct pfil_head *ph)
254 struct netmsg_pfil pfilmsg;
257 nmsg = &pfilmsg.pfil_nmsg;
258 netmsg_init(nmsg, &curthread->td_msgport, 0, pfil_remove_hook_dispatch);
259 pfilmsg.pfil_func = func;
260 pfilmsg.pfil_arg = arg;
261 pfilmsg.pfil_flags = flags;
262 pfilmsg.pfil_ph = ph;
264 return lwkt_domsg(PFIL_CFGPORT, &nmsg->nm_lmsg, 0);
268 * pfil_list_remove is an internal function that takes a function off the
269 * specified list. Clear ph_hashooks if no functions remain on any list.
272 pfil_list_remove(struct pfil_head *ph, pfil_func_t func, void *arg, int flags)
274 struct packet_filter_hook *pfh;
277 KKASSERT(&curthread->td_msgport == PFIL_CFGPORT);
279 list = (flags & PFIL_IN) ? &ph->ph_in : &ph->ph_out;
281 TAILQ_FOREACH(pfh, list, pfil_link) {
282 if (pfh->pfil_func == func && pfh->pfil_arg == arg) {
283 TAILQ_REMOVE(list, pfh, pfil_link);
284 kfree(pfh, M_IFADDR);
285 if (TAILQ_EMPTY(&ph->ph_in) && TAILQ_EMPTY(&ph->ph_out))