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("$FreeBSD$");
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/malloc.h>
46#include <sys/mbuf.h>
47#include <sys/module.h>
48#include <sys/queue.h>
49
50#include <sys/socket.h>
51
52#include <net/if.h>
53#include <net/if_media.h>
54#include <net/ethernet.h>
55#include <net/route.h>
56
57#include <net80211/ieee80211_var.h>
58
59enum {
60	ACL_POLICY_OPEN		= 0,	/* open, don't check ACL's */
61	ACL_POLICY_ALLOW	= 1,	/* allow traffic from MAC */
62	ACL_POLICY_DENY		= 2,	/* deny traffic from MAC */
63	/*
64	 * NB: ACL_POLICY_RADIUS must be the same value as
65	 *     IEEE80211_MACCMD_POLICY_RADIUS because of the way
66	 *     acl_getpolicy() works.
67	 */
68	ACL_POLICY_RADIUS	= 7,	/* defer to RADIUS ACL server */
69};
70
71#define	ACL_HASHSIZE	32
72
73struct acl {
74	TAILQ_ENTRY(acl)	acl_list;
75	LIST_ENTRY(acl)		acl_hash;
76	uint8_t			acl_macaddr[IEEE80211_ADDR_LEN];
77};
78struct aclstate {
79	acl_lock_t		as_lock;
80	int			as_policy;
81	uint32_t		as_nacls;
82	TAILQ_HEAD(, acl)	as_list;	/* list of all ACL's */
83	LIST_HEAD(, acl)	as_hash[ACL_HASHSIZE];
84	struct ieee80211vap	*as_vap;
85};
86
87/* simple hash is enough for variation of macaddr */
88#define	ACL_HASH(addr)	\
89	(((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE)
90
91static MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl");
92
93static	int acl_free_all(struct ieee80211vap *);
94
95/* number of references from net80211 layer */
96static	int nrefs = 0;
97
98static int
99acl_attach(struct ieee80211vap *vap)
100{
101	struct aclstate *as;
102
103	as = (struct aclstate *) IEEE80211_MALLOC(sizeof(struct aclstate),
104		M_80211_ACL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
105	if (as == NULL)
106		return 0;
107	ACL_LOCK_INIT(as, "acl");
108	TAILQ_INIT(&as->as_list);
109	as->as_policy = ACL_POLICY_OPEN;
110	as->as_vap = vap;
111	vap->iv_as = as;
112	nrefs++;			/* NB: we assume caller locking */
113	return 1;
114}
115
116static void
117acl_detach(struct ieee80211vap *vap)
118{
119	struct aclstate *as = vap->iv_as;
120
121	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
122	nrefs--;			/* NB: we assume caller locking */
123
124	acl_free_all(vap);
125	vap->iv_as = NULL;
126	ACL_LOCK_DESTROY(as);
127	IEEE80211_FREE(as, M_80211_ACL);
128}
129
130static __inline struct acl *
131_find_acl(struct aclstate *as, const uint8_t *macaddr)
132{
133	struct acl *acl;
134	int hash;
135
136	hash = ACL_HASH(macaddr);
137	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
138		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
139			return acl;
140	}
141	return NULL;
142}
143
144static void
145_acl_free(struct aclstate *as, struct acl *acl)
146{
147	ACL_LOCK_ASSERT(as);
148
149	TAILQ_REMOVE(&as->as_list, acl, acl_list);
150	LIST_REMOVE(acl, acl_hash);
151	IEEE80211_FREE(acl, M_80211_ACL);
152	as->as_nacls--;
153}
154
155static int
156acl_check(struct ieee80211vap *vap, const struct ieee80211_frame *wh)
157{
158	struct aclstate *as = vap->iv_as;
159
160	switch (as->as_policy) {
161	case ACL_POLICY_OPEN:
162	case ACL_POLICY_RADIUS:
163		return 1;
164	case ACL_POLICY_ALLOW:
165		return _find_acl(as, wh->i_addr2) != NULL;
166	case ACL_POLICY_DENY:
167		return _find_acl(as, wh->i_addr2) == NULL;
168	}
169	return 0;		/* should not happen */
170}
171
172static int
173acl_add(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
174{
175	struct aclstate *as = vap->iv_as;
176	struct acl *acl, *new;
177	int hash;
178
179	new = (struct acl *) IEEE80211_MALLOC(sizeof(struct acl),
180	    M_80211_ACL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
181	if (new == NULL) {
182		IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
183			"ACL: add %s failed, no memory\n", ether_sprintf(mac));
184		/* XXX statistic */
185		return ENOMEM;
186	}
187
188	ACL_LOCK(as);
189	hash = ACL_HASH(mac);
190	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
191		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
192			ACL_UNLOCK(as);
193			IEEE80211_FREE(new, M_80211_ACL);
194			IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
195				"ACL: add %s failed, already present\n",
196				ether_sprintf(mac));
197			return EEXIST;
198		}
199	}
200	IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
201	TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
202	LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
203	as->as_nacls++;
204	ACL_UNLOCK(as);
205
206	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
207		"ACL: add %s\n", ether_sprintf(mac));
208	return 0;
209}
210
211static int
212acl_remove(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
213{
214	struct aclstate *as = vap->iv_as;
215	struct acl *acl;
216
217	ACL_LOCK(as);
218	acl = _find_acl(as, mac);
219	if (acl != NULL)
220		_acl_free(as, acl);
221	ACL_UNLOCK(as);
222
223	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
224		"ACL: remove %s%s\n", ether_sprintf(mac),
225		acl == NULL ? ", not present" : "");
226
227	return (acl == NULL ? ENOENT : 0);
228}
229
230static int
231acl_free_all(struct ieee80211vap *vap)
232{
233	struct aclstate *as = vap->iv_as;
234	struct acl *acl;
235
236	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
237
238	ACL_LOCK(as);
239	while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
240		_acl_free(as, acl);
241	ACL_UNLOCK(as);
242
243	return 0;
244}
245
246static int
247acl_setpolicy(struct ieee80211vap *vap, int policy)
248{
249	struct aclstate *as = vap->iv_as;
250
251	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
252		"ACL: set policy to %u\n", policy);
253
254	switch (policy) {
255	case IEEE80211_MACCMD_POLICY_OPEN:
256		as->as_policy = ACL_POLICY_OPEN;
257		break;
258	case IEEE80211_MACCMD_POLICY_ALLOW:
259		as->as_policy = ACL_POLICY_ALLOW;
260		break;
261	case IEEE80211_MACCMD_POLICY_DENY:
262		as->as_policy = ACL_POLICY_DENY;
263		break;
264	case IEEE80211_MACCMD_POLICY_RADIUS:
265		as->as_policy = ACL_POLICY_RADIUS;
266		break;
267	default:
268		return EINVAL;
269	}
270	return 0;
271}
272
273static int
274acl_getpolicy(struct ieee80211vap *vap)
275{
276	struct aclstate *as = vap->iv_as;
277
278	return as->as_policy;
279}
280
281static int
282acl_setioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
283{
284
285	return EINVAL;
286}
287
288static int
289acl_getioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
290{
291	struct aclstate *as = vap->iv_as;
292	struct acl *acl;
293	struct ieee80211req_maclist *ap;
294	int error;
295	uint32_t i, space;
296
297	switch (ireq->i_val) {
298	case IEEE80211_MACCMD_POLICY:
299		ireq->i_val = as->as_policy;
300		return 0;
301	case IEEE80211_MACCMD_LIST:
302		space = as->as_nacls * IEEE80211_ADDR_LEN;
303		if (ireq->i_len == 0) {
304			ireq->i_len = space;	/* return required space */
305			return 0;		/* NB: must not error */
306		}
307		ap = (struct ieee80211req_maclist *) IEEE80211_MALLOC(space,
308		    M_TEMP, IEEE80211_M_NOWAIT);
309		if (ap == NULL)
310			return ENOMEM;
311		i = 0;
312		ACL_LOCK(as);
313		TAILQ_FOREACH(acl, &as->as_list, acl_list) {
314			IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
315			i++;
316		}
317		ACL_UNLOCK(as);
318		if (ireq->i_len >= space) {
319			error = copyout(ap, ireq->i_data, space);
320			ireq->i_len = space;
321		} else
322			error = copyout(ap, ireq->i_data, ireq->i_len);
323		IEEE80211_FREE(ap, M_TEMP);
324		return error;
325	}
326	return EINVAL;
327}
328
329static const struct ieee80211_aclator mac = {
330	.iac_name	= "mac",
331	.iac_attach	= acl_attach,
332	.iac_detach	= acl_detach,
333	.iac_check	= acl_check,
334	.iac_add	= acl_add,
335	.iac_remove	= acl_remove,
336	.iac_flush	= acl_free_all,
337	.iac_setpolicy	= acl_setpolicy,
338	.iac_getpolicy	= acl_getpolicy,
339	.iac_setioctl	= acl_setioctl,
340	.iac_getioctl	= acl_getioctl,
341};
342IEEE80211_ACL_MODULE(wlan_acl, mac, 1);
343