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 software may be distributed under the terms of the BSD license.
8 * See README for more details.
9 */
10
11 #include "utils/includes.h"
12
13 #include "utils/common.h"
14 #include "utils/eloop.h"
15 #include "common/ieee802_11_defs.h"
16 #include "common/ieee802_11_common.h"
17 #include "drivers/driver.h"
18 #include "hostapd.h"
19 #include "ap_config.h"
20 #include "ieee802_11.h"
21 #include "sta_info.h"
22 #include "beacon.h"
23 #include "ap_list.h"
24
25
26 /* AP list is a double linked list with head->prev pointing to the end of the
27 * list and tail->next = NULL. Entries are moved to the head of the list
28 * whenever a beacon has been received from the AP in question. The tail entry
29 * in this link will thus be the least recently used entry. */
30
31
ap_list_beacon_olbc(struct hostapd_iface * iface,struct ap_info * ap)32 static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
33 {
34 int i;
35
36 if (iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
37 iface->conf->channel != ap->channel)
38 return 0;
39
40 if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
41 return 1;
42
43 for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
44 int rate = (ap->supported_rates[i] & 0x7f) * 5;
45 if (rate == 60 || rate == 90 || rate > 110)
46 return 0;
47 }
48
49 return 1;
50 }
51
52
ap_get_ap(struct hostapd_iface * iface,const u8 * ap)53 struct ap_info * ap_get_ap(struct hostapd_iface *iface, const u8 *ap)
54 {
55 struct ap_info *s;
56
57 s = iface->ap_hash[STA_HASH(ap)];
58 while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
59 s = s->hnext;
60 return s;
61 }
62
63
ap_ap_list_add(struct hostapd_iface * iface,struct ap_info * ap)64 static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
65 {
66 if (iface->ap_list) {
67 ap->prev = iface->ap_list->prev;
68 iface->ap_list->prev = ap;
69 } else
70 ap->prev = ap;
71 ap->next = iface->ap_list;
72 iface->ap_list = ap;
73 }
74
75
ap_ap_list_del(struct hostapd_iface * iface,struct ap_info * ap)76 static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
77 {
78 if (iface->ap_list == ap)
79 iface->ap_list = ap->next;
80 else
81 ap->prev->next = ap->next;
82
83 if (ap->next)
84 ap->next->prev = ap->prev;
85 else if (iface->ap_list)
86 iface->ap_list->prev = ap->prev;
87 }
88
89
ap_ap_iter_list_add(struct hostapd_iface * iface,struct ap_info * ap)90 static void ap_ap_iter_list_add(struct hostapd_iface *iface,
91 struct ap_info *ap)
92 {
93 if (iface->ap_iter_list) {
94 ap->iter_prev = iface->ap_iter_list->iter_prev;
95 iface->ap_iter_list->iter_prev = ap;
96 } else
97 ap->iter_prev = ap;
98 ap->iter_next = iface->ap_iter_list;
99 iface->ap_iter_list = ap;
100 }
101
102
ap_ap_iter_list_del(struct hostapd_iface * iface,struct ap_info * ap)103 static void ap_ap_iter_list_del(struct hostapd_iface *iface,
104 struct ap_info *ap)
105 {
106 if (iface->ap_iter_list == ap)
107 iface->ap_iter_list = ap->iter_next;
108 else
109 ap->iter_prev->iter_next = ap->iter_next;
110
111 if (ap->iter_next)
112 ap->iter_next->iter_prev = ap->iter_prev;
113 else if (iface->ap_iter_list)
114 iface->ap_iter_list->iter_prev = ap->iter_prev;
115 }
116
117
ap_ap_hash_add(struct hostapd_iface * iface,struct ap_info * ap)118 static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
119 {
120 ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
121 iface->ap_hash[STA_HASH(ap->addr)] = ap;
122 }
123
124
ap_ap_hash_del(struct hostapd_iface * iface,struct ap_info * ap)125 static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
126 {
127 struct ap_info *s;
128
129 s = iface->ap_hash[STA_HASH(ap->addr)];
130 if (s == NULL) return;
131 if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
132 iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
133 return;
134 }
135
136 while (s->hnext != NULL &&
137 os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
138 s = s->hnext;
139 if (s->hnext != NULL)
140 s->hnext = s->hnext->hnext;
141 else
142 printf("AP: could not remove AP " MACSTR " from hash table\n",
143 MAC2STR(ap->addr));
144 }
145
146
ap_free_ap(struct hostapd_iface * iface,struct ap_info * ap)147 static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
148 {
149 ap_ap_hash_del(iface, ap);
150 ap_ap_list_del(iface, ap);
151 ap_ap_iter_list_del(iface, ap);
152
153 iface->num_ap--;
154 os_free(ap);
155 }
156
157
hostapd_free_aps(struct hostapd_iface * iface)158 static void hostapd_free_aps(struct hostapd_iface *iface)
159 {
160 struct ap_info *ap, *prev;
161
162 ap = iface->ap_list;
163
164 while (ap) {
165 prev = ap;
166 ap = ap->next;
167 ap_free_ap(iface, prev);
168 }
169
170 iface->ap_list = NULL;
171 }
172
173
ap_ap_for_each(struct hostapd_iface * iface,int (* func)(struct ap_info * s,void * data),void * data)174 int ap_ap_for_each(struct hostapd_iface *iface,
175 int (*func)(struct ap_info *s, void *data), void *data)
176 {
177 struct ap_info *s;
178 int ret = 0;
179
180 s = iface->ap_list;
181
182 while (s) {
183 ret = func(s, data);
184 if (ret)
185 break;
186 s = s->next;
187 }
188
189 return ret;
190 }
191
192
ap_ap_add(struct hostapd_iface * iface,const u8 * addr)193 static struct ap_info * ap_ap_add(struct hostapd_iface *iface, const u8 *addr)
194 {
195 struct ap_info *ap;
196
197 ap = os_zalloc(sizeof(struct ap_info));
198 if (ap == NULL)
199 return NULL;
200
201 /* initialize AP info data */
202 os_memcpy(ap->addr, addr, ETH_ALEN);
203 ap_ap_list_add(iface, ap);
204 iface->num_ap++;
205 ap_ap_hash_add(iface, ap);
206 ap_ap_iter_list_add(iface, ap);
207
208 if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
209 wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
210 MACSTR " from AP table", MAC2STR(ap->prev->addr));
211 ap_free_ap(iface, ap->prev);
212 }
213
214 return ap;
215 }
216
217
ap_list_process_beacon(struct hostapd_iface * iface,const struct ieee80211_mgmt * mgmt,struct ieee802_11_elems * elems,struct hostapd_frame_info * fi)218 void ap_list_process_beacon(struct hostapd_iface *iface,
219 const struct ieee80211_mgmt *mgmt,
220 struct ieee802_11_elems *elems,
221 struct hostapd_frame_info *fi)
222 {
223 struct ap_info *ap;
224 struct os_time now;
225 int new_ap = 0;
226 size_t len;
227 int set_beacon = 0;
228
229 if (iface->conf->ap_table_max_size < 1)
230 return;
231
232 ap = ap_get_ap(iface, mgmt->bssid);
233 if (!ap) {
234 ap = ap_ap_add(iface, mgmt->bssid);
235 if (!ap) {
236 printf("Failed to allocate AP information entry\n");
237 return;
238 }
239 new_ap = 1;
240 }
241
242 ap->beacon_int = le_to_host16(mgmt->u.beacon.beacon_int);
243 ap->capability = le_to_host16(mgmt->u.beacon.capab_info);
244
245 if (elems->ssid) {
246 len = elems->ssid_len;
247 if (len >= sizeof(ap->ssid))
248 len = sizeof(ap->ssid) - 1;
249 os_memcpy(ap->ssid, elems->ssid, len);
250 ap->ssid[len] = '\0';
251 ap->ssid_len = len;
252 }
253
254 merge_byte_arrays(ap->supported_rates, WLAN_SUPP_RATES_MAX,
255 elems->supp_rates, elems->supp_rates_len,
256 elems->ext_supp_rates, elems->ext_supp_rates_len);
257
258 ap->wpa = elems->wpa_ie != NULL;
259
260 if (elems->erp_info && elems->erp_info_len == 1)
261 ap->erp = elems->erp_info[0];
262 else
263 ap->erp = -1;
264
265 if (elems->ds_params && elems->ds_params_len == 1)
266 ap->channel = elems->ds_params[0];
267 else if (fi)
268 ap->channel = fi->channel;
269
270 if (elems->ht_capabilities)
271 ap->ht_support = 1;
272 else
273 ap->ht_support = 0;
274
275 ap->num_beacons++;
276 os_get_time(&now);
277 ap->last_beacon = now.sec;
278 if (fi)
279 ap->datarate = fi->datarate;
280
281 if (!new_ap && ap != iface->ap_list) {
282 /* move AP entry into the beginning of the list so that the
283 * oldest entry is always in the end of the list */
284 ap_ap_list_del(iface, ap);
285 ap_ap_list_add(iface, ap);
286 }
287
288 if (!iface->olbc &&
289 ap_list_beacon_olbc(iface, ap)) {
290 iface->olbc = 1;
291 wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR " - enable "
292 "protection", MAC2STR(ap->addr));
293 set_beacon++;
294 }
295
296 #ifdef CONFIG_IEEE80211N
297 if (!iface->olbc_ht && !ap->ht_support) {
298 iface->olbc_ht = 1;
299 hostapd_ht_operation_update(iface);
300 wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
301 " - enable protection", MAC2STR(ap->addr));
302 set_beacon++;
303 }
304 #endif /* CONFIG_IEEE80211N */
305
306 if (set_beacon)
307 ieee802_11_update_beacons(iface);
308 }
309
310
ap_list_timer(void * eloop_ctx,void * timeout_ctx)311 static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
312 {
313 struct hostapd_iface *iface = eloop_ctx;
314 struct os_time now;
315 struct ap_info *ap;
316 int set_beacon = 0;
317
318 eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
319
320 if (!iface->ap_list)
321 return;
322
323 os_get_time(&now);
324
325 while (iface->ap_list) {
326 ap = iface->ap_list->prev;
327 if (ap->last_beacon + iface->conf->ap_table_expiration_time >=
328 now.sec)
329 break;
330
331 ap_free_ap(iface, ap);
332 }
333
334 if (iface->olbc || iface->olbc_ht) {
335 int olbc = 0;
336 int olbc_ht = 0;
337
338 ap = iface->ap_list;
339 while (ap && (olbc == 0 || olbc_ht == 0)) {
340 if (ap_list_beacon_olbc(iface, ap))
341 olbc = 1;
342 if (!ap->ht_support)
343 olbc_ht = 1;
344 ap = ap->next;
345 }
346 if (!olbc && iface->olbc) {
347 wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
348 iface->olbc = 0;
349 set_beacon++;
350 }
351 #ifdef CONFIG_IEEE80211N
352 if (!olbc_ht && iface->olbc_ht) {
353 wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
354 iface->olbc_ht = 0;
355 hostapd_ht_operation_update(iface);
356 set_beacon++;
357 }
358 #endif /* CONFIG_IEEE80211N */
359 }
360
361 if (set_beacon)
362 ieee802_11_update_beacons(iface);
363 }
364
365
ap_list_init(struct hostapd_iface * iface)366 int ap_list_init(struct hostapd_iface *iface)
367 {
368 eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
369 return 0;
370 }
371
372
ap_list_deinit(struct hostapd_iface * iface)373 void ap_list_deinit(struct hostapd_iface *iface)
374 {
375 eloop_cancel_timeout(ap_list_timer, iface, NULL);
376 hostapd_free_aps(iface);
377 }
378