ieee80211_acl.c revision 228622 
1/*-
2 * Copyright (c) 2004-2008 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 228622 2011-12-17 10:32:31Z bschmidt $");
28
29/*
30 * IEEE 802.11 MAC ACL support.
31 *
32 * When this module is loaded the sender address of each auth mgt
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 "opt_wlan.h"
41
42#include <sys/param.h>
43#include <sys/kernel.h>
44#include <sys/systm.h>
45#include <sys/mbuf.h>
46#include <sys/module.h>
47#include <sys/queue.h>
48
49#include <sys/socket.h>
50
51#include <net/if.h>
52#include <net/if_media.h>
53#include <net/ethernet.h>
54#include <net/route.h>
55
56#include <net80211/ieee80211_var.h>
57
58enum {
59	ACL_POLICY_OPEN		= 0,	/* open, don't check ACL's */
60	ACL_POLICY_ALLOW	= 1,	/* allow traffic from MAC */
61	ACL_POLICY_DENY		= 2,	/* deny traffic from MAC */
62	/*
63	 * NB: ACL_POLICY_RADIUS must be the same value as
64	 *     IEEE80211_MACCMD_POLICY_RADIUS because of the way
65	 *     acl_getpolicy() works.
66	 */
67	ACL_POLICY_RADIUS	= 7,	/* defer to RADIUS ACL server */
68};
69
70#define	ACL_HASHSIZE	32
71
72struct acl {
73	TAILQ_ENTRY(acl)	acl_list;
74	LIST_ENTRY(acl)		acl_hash;
75	uint8_t			acl_macaddr[IEEE80211_ADDR_LEN];
76};
77struct aclstate {
78	acl_lock_t		as_lock;
79	int			as_policy;
80	uint32_t		as_nacls;
81	TAILQ_HEAD(, acl)	as_list;	/* list of all ACL's */
82	LIST_HEAD(, acl)	as_hash[ACL_HASHSIZE];
83	struct ieee80211vap	*as_vap;
84};
85
86/* simple hash is enough for variation of macaddr */
87#define	ACL_HASH(addr)	\
88	(((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE)
89
90static MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl");
91
92static	int acl_free_all(struct ieee80211vap *);
93
94/* number of references from net80211 layer */
95static	int nrefs = 0;
96
97static int
98acl_attach(struct ieee80211vap *vap)
99{
100	struct aclstate *as;
101
102	as = (struct aclstate *) malloc(sizeof(struct aclstate),
103		M_80211_ACL, M_NOWAIT | M_ZERO);
104	if (as == NULL)
105		return 0;
106	ACL_LOCK_INIT(as, "acl");
107	TAILQ_INIT(&as->as_list);
108	as->as_policy = ACL_POLICY_OPEN;
109	as->as_vap = vap;
110	vap->iv_as = as;
111	nrefs++;			/* NB: we assume caller locking */
112	return 1;
113}
114
115static void
116acl_detach(struct ieee80211vap *vap)
117{
118	struct aclstate *as = vap->iv_as;
119
120	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
121	nrefs--;			/* NB: we assume caller locking */
122
123	acl_free_all(vap);
124	vap->iv_as = NULL;
125	ACL_LOCK_DESTROY(as);
126	free(as, M_80211_ACL);
127}
128
129static __inline struct acl *
130_find_acl(struct aclstate *as, const uint8_t *macaddr)
131{
132	struct acl *acl;
133	int hash;
134
135	hash = ACL_HASH(macaddr);
136	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
137		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
138			return acl;
139	}
140	return NULL;
141}
142
143static void
144_acl_free(struct aclstate *as, struct acl *acl)
145{
146	ACL_LOCK_ASSERT(as);
147
148	TAILQ_REMOVE(&as->as_list, acl, acl_list);
149	LIST_REMOVE(acl, acl_hash);
150	free(acl, M_80211_ACL);
151	as->as_nacls--;
152}
153
154static int
155acl_check(struct ieee80211vap *vap, const struct ieee80211_frame *wh)
156{
157	struct aclstate *as = vap->iv_as;
158
159	switch (as->as_policy) {
160	case ACL_POLICY_OPEN:
161	case ACL_POLICY_RADIUS:
162		return 1;
163	case ACL_POLICY_ALLOW:
164		return _find_acl(as, wh->i_addr2) != NULL;
165	case ACL_POLICY_DENY:
166		return _find_acl(as, wh->i_addr2) == NULL;
167	}
168	return 0;		/* should not happen */
169}
170
171static int
172acl_add(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
173{
174	struct aclstate *as = vap->iv_as;
175	struct acl *acl, *new;
176	int hash;
177
178	new = (struct acl *) malloc(sizeof(struct acl), M_80211_ACL, M_NOWAIT | M_ZERO);
179	if (new == NULL) {
180		IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
181			"ACL: add %s failed, no memory\n", ether_sprintf(mac));
182		/* XXX statistic */
183		return ENOMEM;
184	}
185
186	ACL_LOCK(as);
187	hash = ACL_HASH(mac);
188	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
189		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
190			ACL_UNLOCK(as);
191			free(new, M_80211_ACL);
192			IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
193				"ACL: add %s failed, already present\n",
194				ether_sprintf(mac));
195			return EEXIST;
196		}
197	}
198	IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
199	TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
200	LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
201	as->as_nacls++;
202	ACL_UNLOCK(as);
203
204	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
205		"ACL: add %s\n", ether_sprintf(mac));
206	return 0;
207}
208
209static int
210acl_remove(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
211{
212	struct aclstate *as = vap->iv_as;
213	struct acl *acl;
214
215	ACL_LOCK(as);
216	acl = _find_acl(as, mac);
217	if (acl != NULL)
218		_acl_free(as, acl);
219	ACL_UNLOCK(as);
220
221	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
222		"ACL: remove %s%s\n", ether_sprintf(mac),
223		acl == NULL ? ", not present" : "");
224
225	return (acl == NULL ? ENOENT : 0);
226}
227
228static int
229acl_free_all(struct ieee80211vap *vap)
230{
231	struct aclstate *as = vap->iv_as;
232	struct acl *acl;
233
234	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
235
236	ACL_LOCK(as);
237	while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
238		_acl_free(as, acl);
239	ACL_UNLOCK(as);
240
241	return 0;
242}
243
244static int
245acl_setpolicy(struct ieee80211vap *vap, int policy)
246{
247	struct aclstate *as = vap->iv_as;
248
249	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
250		"ACL: set policy to %u\n", policy);
251
252	switch (policy) {
253	case IEEE80211_MACCMD_POLICY_OPEN:
254		as->as_policy = ACL_POLICY_OPEN;
255		break;
256	case IEEE80211_MACCMD_POLICY_ALLOW:
257		as->as_policy = ACL_POLICY_ALLOW;
258		break;
259	case IEEE80211_MACCMD_POLICY_DENY:
260		as->as_policy = ACL_POLICY_DENY;
261		break;
262	case IEEE80211_MACCMD_POLICY_RADIUS:
263		as->as_policy = ACL_POLICY_RADIUS;
264		break;
265	default:
266		return EINVAL;
267	}
268	return 0;
269}
270
271static int
272acl_getpolicy(struct ieee80211vap *vap)
273{
274	struct aclstate *as = vap->iv_as;
275
276	return as->as_policy;
277}
278
279static int
280acl_setioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
281{
282
283	return EINVAL;
284}
285
286static int
287acl_getioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
288{
289	struct aclstate *as = vap->iv_as;
290	struct acl *acl;
291	struct ieee80211req_maclist *ap;
292	int error;
293	uint32_t i, space;
294
295	switch (ireq->i_val) {
296	case IEEE80211_MACCMD_POLICY:
297		ireq->i_val = as->as_policy;
298		return 0;
299	case IEEE80211_MACCMD_LIST:
300		space = as->as_nacls * IEEE80211_ADDR_LEN;
301		if (ireq->i_len == 0) {
302			ireq->i_len = space;	/* return required space */
303			return 0;		/* NB: must not error */
304		}
305		ap = (struct ieee80211req_maclist *) malloc(space,
306		    M_TEMP, M_NOWAIT);
307		if (ap == NULL)
308			return ENOMEM;
309		i = 0;
310		ACL_LOCK(as);
311		TAILQ_FOREACH(acl, &as->as_list, acl_list) {
312			IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
313			i++;
314		}
315		ACL_UNLOCK(as);
316		if (ireq->i_len >= space) {
317			error = copyout(ap, ireq->i_data, space);
318			ireq->i_len = space;
319		} else
320			error = copyout(ap, ireq->i_data, ireq->i_len);
321		free(ap, M_TEMP);
322		return error;
323	}
324	return EINVAL;
325}
326
327static const struct ieee80211_aclator mac = {
328	.iac_name	= "mac",
329	.iac_attach	= acl_attach,
330	.iac_detach	= acl_detach,
331	.iac_check	= acl_check,
332	.iac_add	= acl_add,
333	.iac_remove	= acl_remove,
334	.iac_flush	= acl_free_all,
335	.iac_setpolicy	= acl_setpolicy,
336	.iac_getpolicy	= acl_getpolicy,
337	.iac_setioctl	= acl_setioctl,
338	.iac_getioctl	= acl_getioctl,
339};
340IEEE80211_ACL_MODULE(wlan_acl, mac, 1);
341