Line data Source code
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 "hostapd.h"
18 : #include "ap_config.h"
19 : #include "ieee802_11.h"
20 : #include "sta_info.h"
21 : #include "beacon.h"
22 : #include "ap_list.h"
23 :
24 :
25 : /* AP list is a double linked list with head->prev pointing to the end of the
26 : * list and tail->next = NULL. Entries are moved to the head of the list
27 : * whenever a beacon has been received from the AP in question. The tail entry
28 : * in this link will thus be the least recently used entry. */
29 :
30 :
31 5642 : static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
32 : {
33 : int i;
34 :
35 11284 : if (iface->current_mode == NULL ||
36 11251 : iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
37 5609 : iface->conf->channel != ap->channel)
38 63 : return 0;
39 :
40 5579 : if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
41 0 : return 1;
42 :
43 26743 : for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
44 26742 : int rate = (ap->supported_rates[i] & 0x7f) * 5;
45 26742 : if (rate == 60 || rate == 90 || rate > 110)
46 5578 : return 0;
47 : }
48 :
49 1 : return 1;
50 : }
51 :
52 :
53 5647 : static struct ap_info * ap_get_ap(struct hostapd_iface *iface, const u8 *ap)
54 : {
55 : struct ap_info *s;
56 :
57 5647 : s = iface->ap_hash[STA_HASH(ap)];
58 11305 : while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
59 11 : s = s->hnext;
60 5647 : return s;
61 : }
62 :
63 :
64 287 : static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
65 : {
66 287 : if (iface->ap_list) {
67 35 : ap->prev = iface->ap_list->prev;
68 35 : iface->ap_list->prev = ap;
69 : } else
70 252 : ap->prev = ap;
71 287 : ap->next = iface->ap_list;
72 287 : iface->ap_list = ap;
73 287 : }
74 :
75 :
76 287 : static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
77 : {
78 287 : if (iface->ap_list == ap)
79 259 : iface->ap_list = ap->next;
80 : else
81 28 : ap->prev->next = ap->next;
82 :
83 287 : if (ap->next)
84 7 : ap->next->prev = ap->prev;
85 280 : else if (iface->ap_list)
86 28 : iface->ap_list->prev = ap->prev;
87 287 : }
88 :
89 :
90 281 : static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
91 : {
92 281 : ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
93 281 : iface->ap_hash[STA_HASH(ap->addr)] = ap;
94 281 : }
95 :
96 :
97 281 : static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
98 : {
99 : struct ap_info *s;
100 :
101 281 : s = iface->ap_hash[STA_HASH(ap->addr)];
102 281 : if (s == NULL) return;
103 281 : if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
104 278 : iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
105 278 : return;
106 : }
107 :
108 9 : while (s->hnext != NULL &&
109 3 : os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
110 0 : s = s->hnext;
111 3 : if (s->hnext != NULL)
112 3 : s->hnext = s->hnext->hnext;
113 : else
114 0 : wpa_printf(MSG_INFO, "AP: could not remove AP " MACSTR
115 0 : " from hash table", MAC2STR(ap->addr));
116 : }
117 :
118 :
119 281 : static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
120 : {
121 281 : ap_ap_hash_del(iface, ap);
122 281 : ap_ap_list_del(iface, ap);
123 :
124 281 : iface->num_ap--;
125 281 : os_free(ap);
126 281 : }
127 :
128 :
129 1531 : static void hostapd_free_aps(struct hostapd_iface *iface)
130 : {
131 : struct ap_info *ap, *prev;
132 :
133 1531 : ap = iface->ap_list;
134 :
135 3320 : while (ap) {
136 258 : prev = ap;
137 258 : ap = ap->next;
138 258 : ap_free_ap(iface, prev);
139 : }
140 :
141 1531 : iface->ap_list = NULL;
142 1531 : }
143 :
144 :
145 282 : static struct ap_info * ap_ap_add(struct hostapd_iface *iface, const u8 *addr)
146 : {
147 : struct ap_info *ap;
148 :
149 282 : ap = os_zalloc(sizeof(struct ap_info));
150 282 : if (ap == NULL)
151 1 : return NULL;
152 :
153 : /* initialize AP info data */
154 281 : os_memcpy(ap->addr, addr, ETH_ALEN);
155 281 : ap_ap_list_add(iface, ap);
156 281 : iface->num_ap++;
157 281 : ap_ap_hash_add(iface, ap);
158 :
159 281 : if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
160 132 : wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
161 132 : MACSTR " from AP table", MAC2STR(ap->prev->addr));
162 22 : ap_free_ap(iface, ap->prev);
163 : }
164 :
165 281 : return ap;
166 : }
167 :
168 :
169 5659 : void ap_list_process_beacon(struct hostapd_iface *iface,
170 : const struct ieee80211_mgmt *mgmt,
171 : struct ieee802_11_elems *elems,
172 : struct hostapd_frame_info *fi)
173 : {
174 : struct ap_info *ap;
175 5659 : int new_ap = 0;
176 5659 : int set_beacon = 0;
177 :
178 5659 : if (iface->conf->ap_table_max_size < 1)
179 12 : return;
180 :
181 5647 : ap = ap_get_ap(iface, mgmt->bssid);
182 5647 : if (!ap) {
183 282 : ap = ap_ap_add(iface, mgmt->bssid);
184 282 : if (!ap) {
185 1 : wpa_printf(MSG_INFO,
186 : "Failed to allocate AP information entry");
187 1 : return;
188 : }
189 281 : new_ap = 1;
190 : }
191 :
192 11292 : merge_byte_arrays(ap->supported_rates, WLAN_SUPP_RATES_MAX,
193 5646 : elems->supp_rates, elems->supp_rates_len,
194 5646 : elems->ext_supp_rates, elems->ext_supp_rates_len);
195 :
196 5646 : if (elems->erp_info && elems->erp_info_len == 1)
197 5613 : ap->erp = elems->erp_info[0];
198 : else
199 33 : ap->erp = -1;
200 :
201 5646 : if (elems->ds_params && elems->ds_params_len == 1)
202 5646 : ap->channel = elems->ds_params[0];
203 0 : else if (elems->ht_operation && elems->ht_operation_len >= 1)
204 0 : ap->channel = elems->ht_operation[0];
205 0 : else if (fi)
206 0 : ap->channel = fi->channel;
207 :
208 5646 : if (elems->ht_capabilities)
209 5635 : ap->ht_support = 1;
210 : else
211 11 : ap->ht_support = 0;
212 :
213 5646 : os_get_reltime(&ap->last_beacon);
214 :
215 5646 : if (!new_ap && ap != iface->ap_list) {
216 : /* move AP entry into the beginning of the list so that the
217 : * oldest entry is always in the end of the list */
218 6 : ap_ap_list_del(iface, ap);
219 6 : ap_ap_list_add(iface, ap);
220 : }
221 :
222 11288 : if (!iface->olbc &&
223 5642 : ap_list_beacon_olbc(iface, ap)) {
224 1 : iface->olbc = 1;
225 7 : wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR
226 : " (channel %d) - enable protection",
227 6 : MAC2STR(ap->addr), ap->channel);
228 1 : set_beacon++;
229 : }
230 :
231 : #ifdef CONFIG_IEEE80211N
232 5651 : if (!iface->olbc_ht && !ap->ht_support &&
233 10 : (ap->channel == 0 ||
234 6 : ap->channel == iface->conf->channel ||
235 2 : ap->channel == iface->conf->channel +
236 1 : iface->conf->secondary_channel * 4)) {
237 4 : iface->olbc_ht = 1;
238 4 : hostapd_ht_operation_update(iface);
239 28 : wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
240 : " (channel %d) - enable protection",
241 24 : MAC2STR(ap->addr), ap->channel);
242 4 : set_beacon++;
243 : }
244 : #endif /* CONFIG_IEEE80211N */
245 :
246 5646 : if (set_beacon)
247 4 : ieee802_11_update_beacons(iface);
248 : }
249 :
250 :
251 979 : static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
252 : {
253 979 : struct hostapd_iface *iface = eloop_ctx;
254 : struct os_reltime now;
255 : struct ap_info *ap;
256 979 : int set_beacon = 0;
257 :
258 979 : eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
259 :
260 979 : if (!iface->ap_list)
261 1934 : return;
262 :
263 24 : os_get_reltime(&now);
264 :
265 49 : while (iface->ap_list) {
266 24 : ap = iface->ap_list->prev;
267 24 : if (!os_reltime_expired(&now, &ap->last_beacon,
268 24 : iface->conf->ap_table_expiration_time))
269 23 : break;
270 :
271 1 : ap_free_ap(iface, ap);
272 : }
273 :
274 24 : if (iface->olbc || iface->olbc_ht) {
275 1 : int olbc = 0;
276 1 : int olbc_ht = 0;
277 :
278 1 : ap = iface->ap_list;
279 2 : while (ap && (olbc == 0 || olbc_ht == 0)) {
280 0 : if (ap_list_beacon_olbc(iface, ap))
281 0 : olbc = 1;
282 0 : if (!ap->ht_support)
283 0 : olbc_ht = 1;
284 0 : ap = ap->next;
285 : }
286 1 : if (!olbc && iface->olbc) {
287 1 : wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
288 1 : iface->olbc = 0;
289 1 : set_beacon++;
290 : }
291 : #ifdef CONFIG_IEEE80211N
292 1 : if (!olbc_ht && iface->olbc_ht) {
293 1 : wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
294 1 : iface->olbc_ht = 0;
295 1 : hostapd_ht_operation_update(iface);
296 1 : set_beacon++;
297 : }
298 : #endif /* CONFIG_IEEE80211N */
299 : }
300 :
301 24 : if (set_beacon)
302 1 : ieee802_11_update_beacons(iface);
303 : }
304 :
305 :
306 1337 : int ap_list_init(struct hostapd_iface *iface)
307 : {
308 1337 : eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
309 1337 : return 0;
310 : }
311 :
312 :
313 1531 : void ap_list_deinit(struct hostapd_iface *iface)
314 : {
315 1531 : eloop_cancel_timeout(ap_list_timer, iface, NULL);
316 1531 : hostapd_free_aps(iface);
317 1531 : }
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