xref: /freebsd/contrib/wpa/src/ap/ap_list.c (revision bb15ca603fa442c72dde3f3cb8b46db6970e3950)
1 /*
2  * hostapd / AP table
3  * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
4  * Copyright (c) 2003-2004, Instant802 Networks, Inc.
5  * Copyright (c) 2006, Devicescape Software, Inc.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * Alternatively, this software may be distributed under the terms of BSD
12  * license.
13  *
14  * See README and COPYING for more details.
15  */
16 
17 #include "utils/includes.h"
18 
19 #include "utils/common.h"
20 #include "utils/eloop.h"
21 #include "common/ieee802_11_defs.h"
22 #include "common/ieee802_11_common.h"
23 #include "drivers/driver.h"
24 #include "hostapd.h"
25 #include "ap_config.h"
26 #include "ieee802_11.h"
27 #include "sta_info.h"
28 #include "beacon.h"
29 #include "ap_list.h"
30 
31 
32 /* AP list is a double linked list with head->prev pointing to the end of the
33  * list and tail->next = NULL. Entries are moved to the head of the list
34  * whenever a beacon has been received from the AP in question. The tail entry
35  * in this link will thus be the least recently used entry. */
36 
37 
38 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
39 {
40 	int i;
41 
42 	if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
43 	    iface->conf->channel != ap->channel)
44 		return 0;
45 
46 	if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
47 		return 1;
48 
49 	for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
50 		int rate = (ap->supported_rates[i] & 0x7f) * 5;
51 		if (rate == 60 || rate == 90 || rate > 110)
52 			return 0;
53 	}
54 
55 	return 1;
56 }
57 
58 
59 struct ap_info * ap_get_ap(struct hostapd_iface *iface, const u8 *ap)
60 {
61 	struct ap_info *s;
62 
63 	s = iface->ap_hash[STA_HASH(ap)];
64 	while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
65 		s = s->hnext;
66 	return s;
67 }
68 
69 
70 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
71 {
72 	if (iface->ap_list) {
73 		ap->prev = iface->ap_list->prev;
74 		iface->ap_list->prev = ap;
75 	} else
76 		ap->prev = ap;
77 	ap->next = iface->ap_list;
78 	iface->ap_list = ap;
79 }
80 
81 
82 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
83 {
84 	if (iface->ap_list == ap)
85 		iface->ap_list = ap->next;
86 	else
87 		ap->prev->next = ap->next;
88 
89 	if (ap->next)
90 		ap->next->prev = ap->prev;
91 	else if (iface->ap_list)
92 		iface->ap_list->prev = ap->prev;
93 }
94 
95 
96 static void ap_ap_iter_list_add(struct hostapd_iface *iface,
97 				struct ap_info *ap)
98 {
99 	if (iface->ap_iter_list) {
100 		ap->iter_prev = iface->ap_iter_list->iter_prev;
101 		iface->ap_iter_list->iter_prev = ap;
102 	} else
103 		ap->iter_prev = ap;
104 	ap->iter_next = iface->ap_iter_list;
105 	iface->ap_iter_list = ap;
106 }
107 
108 
109 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
110 				struct ap_info *ap)
111 {
112 	if (iface->ap_iter_list == ap)
113 		iface->ap_iter_list = ap->iter_next;
114 	else
115 		ap->iter_prev->iter_next = ap->iter_next;
116 
117 	if (ap->iter_next)
118 		ap->iter_next->iter_prev = ap->iter_prev;
119 	else if (iface->ap_iter_list)
120 		iface->ap_iter_list->iter_prev = ap->iter_prev;
121 }
122 
123 
124 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
125 {
126 	ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
127 	iface->ap_hash[STA_HASH(ap->addr)] = ap;
128 }
129 
130 
131 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
132 {
133 	struct ap_info *s;
134 
135 	s = iface->ap_hash[STA_HASH(ap->addr)];
136 	if (s == NULL) return;
137 	if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
138 		iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
139 		return;
140 	}
141 
142 	while (s->hnext != NULL &&
143 	       os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
144 		s = s->hnext;
145 	if (s->hnext != NULL)
146 		s->hnext = s->hnext->hnext;
147 	else
148 		printf("AP: could not remove AP " MACSTR " from hash table\n",
149 		       MAC2STR(ap->addr));
150 }
151 
152 
153 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
154 {
155 	ap_ap_hash_del(iface, ap);
156 	ap_ap_list_del(iface, ap);
157 	ap_ap_iter_list_del(iface, ap);
158 
159 	iface->num_ap--;
160 	os_free(ap);
161 }
162 
163 
164 static void hostapd_free_aps(struct hostapd_iface *iface)
165 {
166 	struct ap_info *ap, *prev;
167 
168 	ap = iface->ap_list;
169 
170 	while (ap) {
171 		prev = ap;
172 		ap = ap->next;
173 		ap_free_ap(iface, prev);
174 	}
175 
176 	iface->ap_list = NULL;
177 }
178 
179 
180 int ap_ap_for_each(struct hostapd_iface *iface,
181 		   int (*func)(struct ap_info *s, void *data), void *data)
182 {
183 	struct ap_info *s;
184 	int ret = 0;
185 
186 	s = iface->ap_list;
187 
188 	while (s) {
189 		ret = func(s, data);
190 		if (ret)
191 			break;
192 		s = s->next;
193 	}
194 
195 	return ret;
196 }
197 
198 
199 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, const u8 *addr)
200 {
201 	struct ap_info *ap;
202 
203 	ap = os_zalloc(sizeof(struct ap_info));
204 	if (ap == NULL)
205 		return NULL;
206 
207 	/* initialize AP info data */
208 	os_memcpy(ap->addr, addr, ETH_ALEN);
209 	ap_ap_list_add(iface, ap);
210 	iface->num_ap++;
211 	ap_ap_hash_add(iface, ap);
212 	ap_ap_iter_list_add(iface, ap);
213 
214 	if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
215 		wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
216 			   MACSTR " from AP table", MAC2STR(ap->prev->addr));
217 		ap_free_ap(iface, ap->prev);
218 	}
219 
220 	return ap;
221 }
222 
223 
224 void ap_list_process_beacon(struct hostapd_iface *iface,
225 			    const struct ieee80211_mgmt *mgmt,
226 			    struct ieee802_11_elems *elems,
227 			    struct hostapd_frame_info *fi)
228 {
229 	struct ap_info *ap;
230 	int new_ap = 0;
231 	size_t len;
232 	int set_beacon = 0;
233 
234 	if (iface->conf->ap_table_max_size < 1)
235 		return;
236 
237 	ap = ap_get_ap(iface, mgmt->bssid);
238 	if (!ap) {
239 		ap = ap_ap_add(iface, mgmt->bssid);
240 		if (!ap) {
241 			printf("Failed to allocate AP information entry\n");
242 			return;
243 		}
244 		new_ap = 1;
245 	}
246 
247 	ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
248 	ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
249 
250 	if (elems->ssid) {
251 		len = elems->ssid_len;
252 		if (len >= sizeof(ap->ssid))
253 			len = sizeof(ap->ssid) - 1;
254 		os_memcpy(ap->ssid, elems->ssid, len);
255 		ap->ssid[len] = '\0';
256 		ap->ssid_len = len;
257 	}
258 
259 	os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
260 	len = 0;
261 	if (elems->supp_rates) {
262 		len = elems->supp_rates_len;
263 		if (len > WLAN_SUPP_RATES_MAX)
264 			len = WLAN_SUPP_RATES_MAX;
265 		os_memcpy(ap->supported_rates, elems->supp_rates, len);
266 	}
267 	if (elems->ext_supp_rates) {
268 		int len2;
269 		if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
270 			len2 = WLAN_SUPP_RATES_MAX - len;
271 		else
272 			len2 = elems->ext_supp_rates_len;
273 		os_memcpy(ap->supported_rates + len, elems->ext_supp_rates,
274 			  len2);
275 	}
276 
277 	ap->wpa = elems->wpa_ie != NULL;
278 
279 	if (elems->erp_info && elems->erp_info_len == 1)
280 		ap->erp = elems->erp_info[0];
281 	else
282 		ap->erp = -1;
283 
284 	if (elems->ds_params && elems->ds_params_len == 1)
285 		ap->channel = elems->ds_params[0];
286 	else if (fi)
287 		ap->channel = fi->channel;
288 
289 	if (elems->ht_capabilities)
290 		ap->ht_support = 1;
291 	else
292 		ap->ht_support = 0;
293 
294 	ap->num_beacons++;
295 	time(&ap->last_beacon);
296 	if (fi) {
297 		ap->ssi_signal = fi->ssi_signal;
298 		ap->datarate = fi->datarate;
299 	}
300 
301 	if (!new_ap && ap != iface->ap_list) {
302 		/* move AP entry into the beginning of the list so that the
303 		 * oldest entry is always in the end of the list */
304 		ap_ap_list_del(iface, ap);
305 		ap_ap_list_add(iface, ap);
306 	}
307 
308 	if (!iface->olbc &&
309 	    ap_list_beacon_olbc(iface, ap)) {
310 		iface->olbc = 1;
311 		wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
312 			   "protection", MAC2STR(ap->addr));
313 		set_beacon++;
314 	}
315 
316 #ifdef CONFIG_IEEE80211N
317 	if (!iface->olbc_ht && !ap->ht_support) {
318 		iface->olbc_ht = 1;
319 		hostapd_ht_operation_update(iface);
320 		wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
321 			   " - enable protection", MAC2STR(ap->addr));
322 		set_beacon++;
323 	}
324 #endif /* CONFIG_IEEE80211N */
325 
326 	if (set_beacon)
327 		ieee802_11_set_beacons(iface);
328 }
329 
330 
331 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
332 {
333 	struct hostapd_iface *iface = eloop_ctx;
334 	time_t now;
335 	struct ap_info *ap;
336 	int set_beacon = 0;
337 
338 	eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
339 
340 	if (!iface->ap_list)
341 		return;
342 
343 	time(&now);
344 
345 	while (iface->ap_list) {
346 		ap = iface->ap_list->prev;
347 		if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
348 		    now)
349 			break;
350 
351 		ap_free_ap(iface, ap);
352 	}
353 
354 	if (iface->olbc || iface->olbc_ht) {
355 		int olbc = 0;
356 		int olbc_ht = 0;
357 
358 		ap = iface->ap_list;
359 		while (ap && (olbc == 0 || olbc_ht == 0)) {
360 			if (ap_list_beacon_olbc(iface, ap))
361 				olbc = 1;
362 			if (!ap->ht_support)
363 				olbc_ht = 1;
364 			ap = ap->next;
365 		}
366 		if (!olbc && iface->olbc) {
367 			wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
368 			iface->olbc = 0;
369 			set_beacon++;
370 		}
371 #ifdef CONFIG_IEEE80211N
372 		if (!olbc_ht && iface->olbc_ht) {
373 			wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
374 			iface->olbc_ht = 0;
375 			hostapd_ht_operation_update(iface);
376 			set_beacon++;
377 		}
378 #endif /* CONFIG_IEEE80211N */
379 	}
380 
381 	if (set_beacon)
382 		ieee802_11_set_beacons(iface);
383 }
384 
385 
386 int ap_list_init(struct hostapd_iface *iface)
387 {
388 	eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
389 	return 0;
390 }
391 
392 
393 void ap_list_deinit(struct hostapd_iface *iface)
394 {
395 	eloop_cancel_timeout(ap_list_timer, iface, NULL);
396 	hostapd_free_aps(iface);
397 }
398