ieee80211_acl.c revision 149028 
1/*-
2 * Copyright (c) 2004-2005 Sam Leffler, Errno Consulting
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * Alternatively, this software may be distributed under the terms of the
17 * GNU General Public License ("GPL") version 2 as published by the Free
18 * Software Foundation.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: head/sys/net80211/ieee80211_acl.c 149028 2005-08-13 17:31:48Z sam $");
34
35/*
36 * IEEE 802.11 MAC ACL support.
37 *
38 * When this module is loaded the sender address of each received
39 * frame is passed to the iac_check method and the module indicates
40 * if the frame should be accepted or rejected.  If the policy is
41 * set to ACL_POLICY_OPEN then all frames are accepted w/o checking
42 * the address.  Otherwise, the address is looked up in the database
43 * and if found the frame is either accepted (ACL_POLICY_ALLOW)
44 * or rejected (ACL_POLICY_DENT).
45 */
46#include <sys/param.h>
47#include <sys/kernel.h>
48#include <sys/systm.h>
49#include <sys/mbuf.h>
50#include <sys/module.h>
51#include <sys/queue.h>
52
53#include <sys/socket.h>
54
55#include <net/if.h>
56#include <net/if_media.h>
57#include <net/ethernet.h>
58#include <net/route.h>
59
60#include <net80211/ieee80211_var.h>
61
62enum {
63	ACL_POLICY_OPEN		= 0,	/* open, don't check ACL's */
64	ACL_POLICY_ALLOW	= 1,	/* allow traffic from MAC */
65	ACL_POLICY_DENY		= 2,	/* deny traffic from MAC */
66};
67
68#define	ACL_HASHSIZE	32
69
70struct acl {
71	TAILQ_ENTRY(acl)	acl_list;
72	LIST_ENTRY(acl)		acl_hash;
73	u_int8_t		acl_macaddr[IEEE80211_ADDR_LEN];
74};
75struct aclstate {
76	acl_lock_t		as_lock;
77	int			as_policy;
78	int			as_nacls;
79	TAILQ_HEAD(, acl)	as_list;	/* list of all ACL's */
80	LIST_HEAD(, acl)	as_hash[ACL_HASHSIZE];
81	struct ieee80211com	*as_ic;
82};
83
84/* simple hash is enough for variation of macaddr */
85#define	ACL_HASH(addr)	\
86	(((const u_int8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE)
87
88MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl");
89
90static	int acl_free_all(struct ieee80211com *);
91
92static int
93acl_attach(struct ieee80211com *ic)
94{
95	struct aclstate *as;
96
97	MALLOC(as, struct aclstate *, sizeof(struct aclstate),
98		M_80211_ACL, M_NOWAIT | M_ZERO);
99	if (as == NULL)
100		return 0;
101	ACL_LOCK_INIT(as, "acl");
102	TAILQ_INIT(&as->as_list);
103	as->as_policy = ACL_POLICY_OPEN;
104	as->as_ic = ic;
105	ic->ic_as = as;
106	return 1;
107}
108
109static void
110acl_detach(struct ieee80211com *ic)
111{
112	struct aclstate *as = ic->ic_as;
113
114	acl_free_all(ic);
115	ic->ic_as = NULL;
116	ACL_LOCK_DESTROY(as);
117	FREE(as, M_DEVBUF);
118}
119
120static __inline struct acl *
121_find_acl(struct aclstate *as, const u_int8_t *macaddr)
122{
123	struct acl *acl;
124	int hash;
125
126	hash = ACL_HASH(macaddr);
127	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
128		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
129			return acl;
130	}
131	return NULL;
132}
133
134static void
135_acl_free(struct aclstate *as, struct acl *acl)
136{
137	ACL_LOCK_ASSERT(as);
138
139	TAILQ_REMOVE(&as->as_list, acl, acl_list);
140	LIST_REMOVE(acl, acl_hash);
141	FREE(acl, M_80211_ACL);
142	as->as_nacls--;
143}
144
145static int
146acl_check(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN])
147{
148	struct aclstate *as = ic->ic_as;
149
150	switch (as->as_policy) {
151	case ACL_POLICY_OPEN:
152		return 1;
153	case ACL_POLICY_ALLOW:
154		return _find_acl(as, mac) != NULL;
155	case ACL_POLICY_DENY:
156		return _find_acl(as, mac) == NULL;
157	}
158	return 0;		/* should not happen */
159}
160
161static int
162acl_add(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN])
163{
164	struct aclstate *as = ic->ic_as;
165	struct acl *acl, *new;
166	int hash;
167
168	MALLOC(new, struct acl *, sizeof(struct acl), M_80211_ACL, M_NOWAIT | M_ZERO);
169	if (new == NULL) {
170		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
171			"ACL: add %s failed, no memory\n", ether_sprintf(mac));
172		/* XXX statistic */
173		return ENOMEM;
174	}
175
176	ACL_LOCK(as);
177	hash = ACL_HASH(mac);
178	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
179		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
180			ACL_UNLOCK(as);
181			FREE(new, M_80211_ACL);
182			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
183				"ACL: add %s failed, already present\n",
184				ether_sprintf(mac));
185			return EEXIST;
186		}
187	}
188	IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
189	TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
190	LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
191	as->as_nacls++;
192	ACL_UNLOCK(as);
193
194	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
195		"ACL: add %s\n", ether_sprintf(mac));
196	return 0;
197}
198
199static int
200acl_remove(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN])
201{
202	struct aclstate *as = ic->ic_as;
203	struct acl *acl;
204
205	ACL_LOCK(as);
206	acl = _find_acl(as, mac);
207	if (acl != NULL)
208		_acl_free(as, acl);
209	ACL_UNLOCK(as);
210
211	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
212		"ACL: remove %s%s\n", ether_sprintf(mac),
213		acl == NULL ? ", not present" : "");
214
215	return (acl == NULL ? ENOENT : 0);
216}
217
218static int
219acl_free_all(struct ieee80211com *ic)
220{
221	struct aclstate *as = ic->ic_as;
222	struct acl *acl;
223
224	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
225
226	ACL_LOCK(as);
227	while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
228		_acl_free(as, acl);
229	ACL_UNLOCK(as);
230
231	return 0;
232}
233
234static int
235acl_setpolicy(struct ieee80211com *ic, int policy)
236{
237	struct aclstate *as = ic->ic_as;
238
239	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
240		"ACL: set policy to %u\n", policy);
241
242	switch (policy) {
243	case IEEE80211_MACCMD_POLICY_OPEN:
244		as->as_policy = ACL_POLICY_OPEN;
245		break;
246	case IEEE80211_MACCMD_POLICY_ALLOW:
247		as->as_policy = ACL_POLICY_ALLOW;
248		break;
249	case IEEE80211_MACCMD_POLICY_DENY:
250		as->as_policy = ACL_POLICY_DENY;
251		break;
252	default:
253		return EINVAL;
254	}
255	return 0;
256}
257
258static int
259acl_getpolicy(struct ieee80211com *ic)
260{
261	struct aclstate *as = ic->ic_as;
262
263	return as->as_policy;
264}
265
266static int
267acl_setioctl(struct ieee80211com *ic, struct ieee80211req *ireq)
268{
269
270	return EINVAL;
271}
272
273static int
274acl_getioctl(struct ieee80211com *ic, struct ieee80211req *ireq)
275{
276	struct aclstate *as = ic->ic_as;
277	struct acl *acl;
278	struct ieee80211req_maclist *ap;
279	int error, space, i;
280
281	switch (ireq->i_val) {
282	case IEEE80211_MACCMD_POLICY:
283		ireq->i_val = as->as_policy;
284		return 0;
285	case IEEE80211_MACCMD_LIST:
286		space = as->as_nacls * IEEE80211_ADDR_LEN;
287		if (ireq->i_len == 0) {
288			ireq->i_len = space;	/* return required space */
289			return 0;		/* NB: must not error */
290		}
291		MALLOC(ap, struct ieee80211req_maclist *, space,
292			M_TEMP, M_NOWAIT);
293		if (ap == NULL)
294			return ENOMEM;
295		i = 0;
296		ACL_LOCK(as);
297		TAILQ_FOREACH(acl, &as->as_list, acl_list) {
298			IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
299			i++;
300		}
301		ACL_UNLOCK(as);
302		if (ireq->i_len >= space) {
303			error = copyout(ap, ireq->i_data, space);
304			ireq->i_len = space;
305		} else
306			error = copyout(ap, ireq->i_data, ireq->i_len);
307		FREE(ap, M_TEMP);
308		return error;
309	}
310	return EINVAL;
311}
312
313static const struct ieee80211_aclator mac = {
314	.iac_name	= "mac",
315	.iac_attach	= acl_attach,
316	.iac_detach	= acl_detach,
317	.iac_check	= acl_check,
318	.iac_add	= acl_add,
319	.iac_remove	= acl_remove,
320	.iac_flush	= acl_free_all,
321	.iac_setpolicy	= acl_setpolicy,
322	.iac_getpolicy	= acl_getpolicy,
323	.iac_setioctl	= acl_setioctl,
324	.iac_getioctl	= acl_getioctl,
325};
326
327/*
328 * Module glue.
329 */
330static int
331wlan_acl_modevent(module_t mod, int type, void *unused)
332{
333	switch (type) {
334	case MOD_LOAD:
335		if (bootverbose)
336			printf("wlan: <802.11 MAC ACL support>\n");
337		ieee80211_aclator_register(&mac);
338		return 0;
339	case MOD_UNLOAD:
340		ieee80211_aclator_unregister(&mac);
341		return 0;
342	}
343	return EINVAL;
344}
345
346static moduledata_t wlan_acl_mod = {
347	"wlan_acl",
348	wlan_acl_modevent,
349	0
350};
351DECLARE_MODULE(wlan_acl, wlan_acl_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
352MODULE_VERSION(wlan_acl, 1);
353MODULE_DEPEND(wlan_acl, wlan, 1, 1, 1);
354