ieee80211_acl.c revision 170530 
1/*-
2 * Copyright (c) 2004-2007 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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include <sys/cdefs.h>
27__FBSDID("$FreeBSD: head/sys/net80211/ieee80211_acl.c 170530 2007-06-11 03:36:55Z sam $");
28
29/*
30 * IEEE 802.11 MAC ACL support.
31 *
32 * When this module is loaded the sender address of each received
33 * frame is passed to the iac_check method and the module indicates
34 * if the frame should be accepted or rejected.  If the policy is
35 * set to ACL_POLICY_OPEN then all frames are accepted w/o checking
36 * the address.  Otherwise, the address is looked up in the database
37 * and if found the frame is either accepted (ACL_POLICY_ALLOW)
38 * or rejected (ACL_POLICY_DENT).
39 */
40#include <sys/param.h>
41#include <sys/kernel.h>
42#include <sys/systm.h>
43#include <sys/mbuf.h>
44#include <sys/module.h>
45#include <sys/queue.h>
46
47#include <sys/socket.h>
48
49#include <net/if.h>
50#include <net/if_media.h>
51#include <net/ethernet.h>
52#include <net/route.h>
53
54#include <net80211/ieee80211_var.h>
55
56enum {
57	ACL_POLICY_OPEN		= 0,	/* open, don't check ACL's */
58	ACL_POLICY_ALLOW	= 1,	/* allow traffic from MAC */
59	ACL_POLICY_DENY		= 2,	/* deny traffic from MAC */
60};
61
62#define	ACL_HASHSIZE	32
63
64struct acl {
65	TAILQ_ENTRY(acl)	acl_list;
66	LIST_ENTRY(acl)		acl_hash;
67	uint8_t			acl_macaddr[IEEE80211_ADDR_LEN];
68};
69struct aclstate {
70	acl_lock_t		as_lock;
71	int			as_policy;
72	int			as_nacls;
73	TAILQ_HEAD(, acl)	as_list;	/* list of all ACL's */
74	LIST_HEAD(, acl)	as_hash[ACL_HASHSIZE];
75	struct ieee80211com	*as_ic;
76};
77
78/* simple hash is enough for variation of macaddr */
79#define	ACL_HASH(addr)	\
80	(((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE)
81
82MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl");
83
84static	int acl_free_all(struct ieee80211com *);
85
86static int
87acl_attach(struct ieee80211com *ic)
88{
89	struct aclstate *as;
90
91	MALLOC(as, struct aclstate *, sizeof(struct aclstate),
92		M_80211_ACL, M_NOWAIT | M_ZERO);
93	if (as == NULL)
94		return 0;
95	ACL_LOCK_INIT(as, "acl");
96	TAILQ_INIT(&as->as_list);
97	as->as_policy = ACL_POLICY_OPEN;
98	as->as_ic = ic;
99	ic->ic_as = as;
100	return 1;
101}
102
103static void
104acl_detach(struct ieee80211com *ic)
105{
106	struct aclstate *as = ic->ic_as;
107
108	acl_free_all(ic);
109	ic->ic_as = NULL;
110	ACL_LOCK_DESTROY(as);
111	FREE(as, M_DEVBUF);
112}
113
114static __inline struct acl *
115_find_acl(struct aclstate *as, const uint8_t *macaddr)
116{
117	struct acl *acl;
118	int hash;
119
120	hash = ACL_HASH(macaddr);
121	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
122		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
123			return acl;
124	}
125	return NULL;
126}
127
128static void
129_acl_free(struct aclstate *as, struct acl *acl)
130{
131	ACL_LOCK_ASSERT(as);
132
133	TAILQ_REMOVE(&as->as_list, acl, acl_list);
134	LIST_REMOVE(acl, acl_hash);
135	FREE(acl, M_80211_ACL);
136	as->as_nacls--;
137}
138
139static int
140acl_check(struct ieee80211com *ic, const uint8_t mac[IEEE80211_ADDR_LEN])
141{
142	struct aclstate *as = ic->ic_as;
143
144	switch (as->as_policy) {
145	case ACL_POLICY_OPEN:
146		return 1;
147	case ACL_POLICY_ALLOW:
148		return _find_acl(as, mac) != NULL;
149	case ACL_POLICY_DENY:
150		return _find_acl(as, mac) == NULL;
151	}
152	return 0;		/* should not happen */
153}
154
155static int
156acl_add(struct ieee80211com *ic, const uint8_t mac[IEEE80211_ADDR_LEN])
157{
158	struct aclstate *as = ic->ic_as;
159	struct acl *acl, *new;
160	int hash;
161
162	MALLOC(new, struct acl *, sizeof(struct acl), M_80211_ACL, M_NOWAIT | M_ZERO);
163	if (new == NULL) {
164		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
165			"ACL: add %s failed, no memory\n", ether_sprintf(mac));
166		/* XXX statistic */
167		return ENOMEM;
168	}
169
170	ACL_LOCK(as);
171	hash = ACL_HASH(mac);
172	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
173		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
174			ACL_UNLOCK(as);
175			FREE(new, M_80211_ACL);
176			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
177				"ACL: add %s failed, already present\n",
178				ether_sprintf(mac));
179			return EEXIST;
180		}
181	}
182	IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
183	TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
184	LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
185	as->as_nacls++;
186	ACL_UNLOCK(as);
187
188	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
189		"ACL: add %s\n", ether_sprintf(mac));
190	return 0;
191}
192
193static int
194acl_remove(struct ieee80211com *ic, const uint8_t mac[IEEE80211_ADDR_LEN])
195{
196	struct aclstate *as = ic->ic_as;
197	struct acl *acl;
198
199	ACL_LOCK(as);
200	acl = _find_acl(as, mac);
201	if (acl != NULL)
202		_acl_free(as, acl);
203	ACL_UNLOCK(as);
204
205	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
206		"ACL: remove %s%s\n", ether_sprintf(mac),
207		acl == NULL ? ", not present" : "");
208
209	return (acl == NULL ? ENOENT : 0);
210}
211
212static int
213acl_free_all(struct ieee80211com *ic)
214{
215	struct aclstate *as = ic->ic_as;
216	struct acl *acl;
217
218	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
219
220	ACL_LOCK(as);
221	while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
222		_acl_free(as, acl);
223	ACL_UNLOCK(as);
224
225	return 0;
226}
227
228static int
229acl_setpolicy(struct ieee80211com *ic, int policy)
230{
231	struct aclstate *as = ic->ic_as;
232
233	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
234		"ACL: set policy to %u\n", policy);
235
236	switch (policy) {
237	case IEEE80211_MACCMD_POLICY_OPEN:
238		as->as_policy = ACL_POLICY_OPEN;
239		break;
240	case IEEE80211_MACCMD_POLICY_ALLOW:
241		as->as_policy = ACL_POLICY_ALLOW;
242		break;
243	case IEEE80211_MACCMD_POLICY_DENY:
244		as->as_policy = ACL_POLICY_DENY;
245		break;
246	default:
247		return EINVAL;
248	}
249	return 0;
250}
251
252static int
253acl_getpolicy(struct ieee80211com *ic)
254{
255	struct aclstate *as = ic->ic_as;
256
257	return as->as_policy;
258}
259
260static int
261acl_setioctl(struct ieee80211com *ic, struct ieee80211req *ireq)
262{
263
264	return EINVAL;
265}
266
267static int
268acl_getioctl(struct ieee80211com *ic, struct ieee80211req *ireq)
269{
270	struct aclstate *as = ic->ic_as;
271	struct acl *acl;
272	struct ieee80211req_maclist *ap;
273	int error, space, i;
274
275	switch (ireq->i_val) {
276	case IEEE80211_MACCMD_POLICY:
277		ireq->i_val = as->as_policy;
278		return 0;
279	case IEEE80211_MACCMD_LIST:
280		space = as->as_nacls * IEEE80211_ADDR_LEN;
281		if (ireq->i_len == 0) {
282			ireq->i_len = space;	/* return required space */
283			return 0;		/* NB: must not error */
284		}
285		MALLOC(ap, struct ieee80211req_maclist *, space,
286			M_TEMP, M_NOWAIT);
287		if (ap == NULL)
288			return ENOMEM;
289		i = 0;
290		ACL_LOCK(as);
291		TAILQ_FOREACH(acl, &as->as_list, acl_list) {
292			IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
293			i++;
294		}
295		ACL_UNLOCK(as);
296		if (ireq->i_len >= space) {
297			error = copyout(ap, ireq->i_data, space);
298			ireq->i_len = space;
299		} else
300			error = copyout(ap, ireq->i_data, ireq->i_len);
301		FREE(ap, M_TEMP);
302		return error;
303	}
304	return EINVAL;
305}
306
307static const struct ieee80211_aclator mac = {
308	.iac_name	= "mac",
309	.iac_attach	= acl_attach,
310	.iac_detach	= acl_detach,
311	.iac_check	= acl_check,
312	.iac_add	= acl_add,
313	.iac_remove	= acl_remove,
314	.iac_flush	= acl_free_all,
315	.iac_setpolicy	= acl_setpolicy,
316	.iac_getpolicy	= acl_getpolicy,
317	.iac_setioctl	= acl_setioctl,
318	.iac_getioctl	= acl_getioctl,
319};
320
321/*
322 * Module glue.
323 */
324static int
325wlan_acl_modevent(module_t mod, int type, void *unused)
326{
327	switch (type) {
328	case MOD_LOAD:
329		if (bootverbose)
330			printf("wlan: <802.11 MAC ACL support>\n");
331		ieee80211_aclator_register(&mac);
332		return 0;
333	case MOD_UNLOAD:
334		ieee80211_aclator_unregister(&mac);
335		return 0;
336	}
337	return EINVAL;
338}
339
340static moduledata_t wlan_acl_mod = {
341	"wlan_acl",
342	wlan_acl_modevent,
343	0
344};
345DECLARE_MODULE(wlan_acl, wlan_acl_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
346MODULE_VERSION(wlan_acl, 1);
347MODULE_DEPEND(wlan_acl, wlan, 1, 1, 1);
348