ieee80211_acl.c revision 283538 
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 283538 2015-05-25 19:18:16Z adrian $");
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 *) IEEE80211_MALLOC(sizeof(struct aclstate),
103		M_80211_ACL, IEEE80211_M_NOWAIT | IEEE80211_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	IEEE80211_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	IEEE80211_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 *) IEEE80211_MALLOC(sizeof(struct acl),
179	    M_80211_ACL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
180	if (new == NULL) {
181		IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
182			"ACL: add %s failed, no memory\n", ether_sprintf(mac));
183		/* XXX statistic */
184		return ENOMEM;
185	}
186
187	ACL_LOCK(as);
188	hash = ACL_HASH(mac);
189	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
190		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
191			ACL_UNLOCK(as);
192			IEEE80211_FREE(new, M_80211_ACL);
193			IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
194				"ACL: add %s failed, already present\n",
195				ether_sprintf(mac));
196			return EEXIST;
197		}
198	}
199	IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
200	TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
201	LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
202	as->as_nacls++;
203	ACL_UNLOCK(as);
204
205	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
206		"ACL: add %s\n", ether_sprintf(mac));
207	return 0;
208}
209
210static int
211acl_remove(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
212{
213	struct aclstate *as = vap->iv_as;
214	struct acl *acl;
215
216	ACL_LOCK(as);
217	acl = _find_acl(as, mac);
218	if (acl != NULL)
219		_acl_free(as, acl);
220	ACL_UNLOCK(as);
221
222	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
223		"ACL: remove %s%s\n", ether_sprintf(mac),
224		acl == NULL ? ", not present" : "");
225
226	return (acl == NULL ? ENOENT : 0);
227}
228
229static int
230acl_free_all(struct ieee80211vap *vap)
231{
232	struct aclstate *as = vap->iv_as;
233	struct acl *acl;
234
235	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
236
237	ACL_LOCK(as);
238	while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
239		_acl_free(as, acl);
240	ACL_UNLOCK(as);
241
242	return 0;
243}
244
245static int
246acl_setpolicy(struct ieee80211vap *vap, int policy)
247{
248	struct aclstate *as = vap->iv_as;
249
250	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
251		"ACL: set policy to %u\n", policy);
252
253	switch (policy) {
254	case IEEE80211_MACCMD_POLICY_OPEN:
255		as->as_policy = ACL_POLICY_OPEN;
256		break;
257	case IEEE80211_MACCMD_POLICY_ALLOW:
258		as->as_policy = ACL_POLICY_ALLOW;
259		break;
260	case IEEE80211_MACCMD_POLICY_DENY:
261		as->as_policy = ACL_POLICY_DENY;
262		break;
263	case IEEE80211_MACCMD_POLICY_RADIUS:
264		as->as_policy = ACL_POLICY_RADIUS;
265		break;
266	default:
267		return EINVAL;
268	}
269	return 0;
270}
271
272static int
273acl_getpolicy(struct ieee80211vap *vap)
274{
275	struct aclstate *as = vap->iv_as;
276
277	return as->as_policy;
278}
279
280static int
281acl_setioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
282{
283
284	return EINVAL;
285}
286
287static int
288acl_getioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
289{
290	struct aclstate *as = vap->iv_as;
291	struct acl *acl;
292	struct ieee80211req_maclist *ap;
293	int error;
294	uint32_t i, space;
295
296	switch (ireq->i_val) {
297	case IEEE80211_MACCMD_POLICY:
298		ireq->i_val = as->as_policy;
299		return 0;
300	case IEEE80211_MACCMD_LIST:
301		space = as->as_nacls * IEEE80211_ADDR_LEN;
302		if (ireq->i_len == 0) {
303			ireq->i_len = space;	/* return required space */
304			return 0;		/* NB: must not error */
305		}
306		ap = (struct ieee80211req_maclist *) IEEE80211_MALLOC(space,
307		    M_TEMP, IEEE80211_M_NOWAIT);
308		if (ap == NULL)
309			return ENOMEM;
310		i = 0;
311		ACL_LOCK(as);
312		TAILQ_FOREACH(acl, &as->as_list, acl_list) {
313			IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
314			i++;
315		}
316		ACL_UNLOCK(as);
317		if (ireq->i_len >= space) {
318			error = copyout(ap, ireq->i_data, space);
319			ireq->i_len = space;
320		} else
321			error = copyout(ap, ireq->i_data, ireq->i_len);
322		IEEE80211_FREE(ap, M_TEMP);
323		return error;
324	}
325	return EINVAL;
326}
327
328static const struct ieee80211_aclator mac = {
329	.iac_name	= "mac",
330	.iac_attach	= acl_attach,
331	.iac_detach	= acl_detach,
332	.iac_check	= acl_check,
333	.iac_add	= acl_add,
334	.iac_remove	= acl_remove,
335	.iac_flush	= acl_free_all,
336	.iac_setpolicy	= acl_setpolicy,
337	.iac_getpolicy	= acl_getpolicy,
338	.iac_setioctl	= acl_setioctl,
339	.iac_getioctl	= acl_getioctl,
340};
341IEEE80211_ACL_MODULE(wlan_acl, mac, 1);
342