1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2004-2008 Sam Leffler, Errno Consulting
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: releng/12.0/sys/net80211/ieee80211_acl.c 326272 2017-11-27 15:23:17Z pfg $");
30
31/*
32 * IEEE 802.11 MAC ACL support.
33 *
34 * When this module is loaded the sender address of each auth mgt
35 * frame is passed to the iac_check method and the module indicates
36 * if the frame should be accepted or rejected.  If the policy is
37 * set to ACL_POLICY_OPEN then all frames are accepted w/o checking
38 * the address.  Otherwise, the address is looked up in the database
39 * and if found the frame is either accepted (ACL_POLICY_ALLOW)
40 * or rejected (ACL_POLICY_DENT).
41 */
42#include "opt_wlan.h"
43
44#include <sys/param.h>
45#include <sys/kernel.h>
46#include <sys/systm.h>
47#include <sys/malloc.h>
48#include <sys/mbuf.h>
49#include <sys/module.h>
50#include <sys/queue.h>
51
52#include <sys/socket.h>
53
54#include <net/if.h>
55#include <net/if_media.h>
56#include <net/ethernet.h>
57#include <net/route.h>
58
59#include <net80211/ieee80211_var.h>
60
61enum {
62	ACL_POLICY_OPEN		= 0,	/* open, don't check ACL's */
63	ACL_POLICY_ALLOW	= 1,	/* allow traffic from MAC */
64	ACL_POLICY_DENY		= 2,	/* deny traffic from MAC */
65	/*
66	 * NB: ACL_POLICY_RADIUS must be the same value as
67	 *     IEEE80211_MACCMD_POLICY_RADIUS because of the way
68	 *     acl_getpolicy() works.
69	 */
70	ACL_POLICY_RADIUS	= 7,	/* defer to RADIUS ACL server */
71};
72
73#define	ACL_HASHSIZE	32
74
75struct acl {
76	TAILQ_ENTRY(acl)	acl_list;
77	LIST_ENTRY(acl)		acl_hash;
78	uint8_t			acl_macaddr[IEEE80211_ADDR_LEN];
79};
80struct aclstate {
81	acl_lock_t		as_lock;
82	int			as_policy;
83	uint32_t		as_nacls;
84	TAILQ_HEAD(, acl)	as_list;	/* list of all ACL's */
85	LIST_HEAD(, acl)	as_hash[ACL_HASHSIZE];
86	struct ieee80211vap	*as_vap;
87};
88
89/* simple hash is enough for variation of macaddr */
90#define	ACL_HASH(addr)	\
91	(((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE)
92
93static MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl");
94
95static	int acl_free_all(struct ieee80211vap *);
96
97/* number of references from net80211 layer */
98static	int nrefs = 0;
99
100static int
101acl_attach(struct ieee80211vap *vap)
102{
103	struct aclstate *as;
104
105	as = (struct aclstate *) IEEE80211_MALLOC(sizeof(struct aclstate),
106		M_80211_ACL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
107	if (as == NULL)
108		return 0;
109	ACL_LOCK_INIT(as, "acl");
110	TAILQ_INIT(&as->as_list);
111	as->as_policy = ACL_POLICY_OPEN;
112	as->as_vap = vap;
113	vap->iv_as = as;
114	nrefs++;			/* NB: we assume caller locking */
115	return 1;
116}
117
118static void
119acl_detach(struct ieee80211vap *vap)
120{
121	struct aclstate *as = vap->iv_as;
122
123	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
124	nrefs--;			/* NB: we assume caller locking */
125
126	acl_free_all(vap);
127	vap->iv_as = NULL;
128	ACL_LOCK_DESTROY(as);
129	IEEE80211_FREE(as, M_80211_ACL);
130}
131
132static __inline struct acl *
133_find_acl(struct aclstate *as, const uint8_t *macaddr)
134{
135	struct acl *acl;
136	int hash;
137
138	hash = ACL_HASH(macaddr);
139	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
140		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
141			return acl;
142	}
143	return NULL;
144}
145
146static void
147_acl_free(struct aclstate *as, struct acl *acl)
148{
149	ACL_LOCK_ASSERT(as);
150
151	TAILQ_REMOVE(&as->as_list, acl, acl_list);
152	LIST_REMOVE(acl, acl_hash);
153	IEEE80211_FREE(acl, M_80211_ACL);
154	as->as_nacls--;
155}
156
157static int
158acl_check(struct ieee80211vap *vap, const struct ieee80211_frame *wh)
159{
160	struct aclstate *as = vap->iv_as;
161
162	switch (as->as_policy) {
163	case ACL_POLICY_OPEN:
164	case ACL_POLICY_RADIUS:
165		return 1;
166	case ACL_POLICY_ALLOW:
167		return _find_acl(as, wh->i_addr2) != NULL;
168	case ACL_POLICY_DENY:
169		return _find_acl(as, wh->i_addr2) == NULL;
170	}
171	return 0;		/* should not happen */
172}
173
174static int
175acl_add(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
176{
177	struct aclstate *as = vap->iv_as;
178	struct acl *acl, *new;
179	int hash;
180
181	new = (struct acl *) IEEE80211_MALLOC(sizeof(struct acl),
182	    M_80211_ACL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
183	if (new == NULL) {
184		IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
185			"ACL: add %s failed, no memory\n", ether_sprintf(mac));
186		/* XXX statistic */
187		return ENOMEM;
188	}
189
190	ACL_LOCK(as);
191	hash = ACL_HASH(mac);
192	LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
193		if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
194			ACL_UNLOCK(as);
195			IEEE80211_FREE(new, M_80211_ACL);
196			IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
197				"ACL: add %s failed, already present\n",
198				ether_sprintf(mac));
199			return EEXIST;
200		}
201	}
202	IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
203	TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
204	LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
205	as->as_nacls++;
206	ACL_UNLOCK(as);
207
208	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
209		"ACL: add %s\n", ether_sprintf(mac));
210	return 0;
211}
212
213static int
214acl_remove(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
215{
216	struct aclstate *as = vap->iv_as;
217	struct acl *acl;
218
219	ACL_LOCK(as);
220	acl = _find_acl(as, mac);
221	if (acl != NULL)
222		_acl_free(as, acl);
223	ACL_UNLOCK(as);
224
225	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
226		"ACL: remove %s%s\n", ether_sprintf(mac),
227		acl == NULL ? ", not present" : "");
228
229	return (acl == NULL ? ENOENT : 0);
230}
231
232static int
233acl_free_all(struct ieee80211vap *vap)
234{
235	struct aclstate *as = vap->iv_as;
236	struct acl *acl;
237
238	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
239
240	ACL_LOCK(as);
241	while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
242		_acl_free(as, acl);
243	ACL_UNLOCK(as);
244
245	return 0;
246}
247
248static int
249acl_setpolicy(struct ieee80211vap *vap, int policy)
250{
251	struct aclstate *as = vap->iv_as;
252
253	IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
254		"ACL: set policy to %u\n", policy);
255
256	switch (policy) {
257	case IEEE80211_MACCMD_POLICY_OPEN:
258		as->as_policy = ACL_POLICY_OPEN;
259		break;
260	case IEEE80211_MACCMD_POLICY_ALLOW:
261		as->as_policy = ACL_POLICY_ALLOW;
262		break;
263	case IEEE80211_MACCMD_POLICY_DENY:
264		as->as_policy = ACL_POLICY_DENY;
265		break;
266	case IEEE80211_MACCMD_POLICY_RADIUS:
267		as->as_policy = ACL_POLICY_RADIUS;
268		break;
269	default:
270		return EINVAL;
271	}
272	return 0;
273}
274
275static int
276acl_getpolicy(struct ieee80211vap *vap)
277{
278	struct aclstate *as = vap->iv_as;
279
280	return as->as_policy;
281}
282
283static int
284acl_setioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
285{
286
287	return EINVAL;
288}
289
290static int
291acl_getioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
292{
293	struct aclstate *as = vap->iv_as;
294	struct acl *acl;
295	struct ieee80211req_maclist *ap;
296	int error;
297	uint32_t i, space;
298
299	switch (ireq->i_val) {
300	case IEEE80211_MACCMD_POLICY:
301		ireq->i_val = as->as_policy;
302		return 0;
303	case IEEE80211_MACCMD_LIST:
304		space = as->as_nacls * IEEE80211_ADDR_LEN;
305		if (ireq->i_len == 0) {
306			ireq->i_len = space;	/* return required space */
307			return 0;		/* NB: must not error */
308		}
309		ap = (struct ieee80211req_maclist *) IEEE80211_MALLOC(space,
310		    M_TEMP, IEEE80211_M_NOWAIT);
311		if (ap == NULL)
312			return ENOMEM;
313		i = 0;
314		ACL_LOCK(as);
315		TAILQ_FOREACH(acl, &as->as_list, acl_list) {
316			IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
317			i++;
318		}
319		ACL_UNLOCK(as);
320		if (ireq->i_len >= space) {
321			error = copyout(ap, ireq->i_data, space);
322			ireq->i_len = space;
323		} else
324			error = copyout(ap, ireq->i_data, ireq->i_len);
325		IEEE80211_FREE(ap, M_TEMP);
326		return error;
327	}
328	return EINVAL;
329}
330
331static const struct ieee80211_aclator mac = {
332	.iac_name	= "mac",
333	.iac_attach	= acl_attach,
334	.iac_detach	= acl_detach,
335	.iac_check	= acl_check,
336	.iac_add	= acl_add,
337	.iac_remove	= acl_remove,
338	.iac_flush	= acl_free_all,
339	.iac_setpolicy	= acl_setpolicy,
340	.iac_getpolicy	= acl_getpolicy,
341	.iac_setioctl	= acl_setioctl,
342	.iac_getioctl	= acl_getioctl,
343};
344IEEE80211_ACL_MODULE(wlan_acl, mac, 1);
345