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 1851 : static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
32 : {
33 : int i;
34 :
35 3702 : if (iface->current_mode == NULL ||
36 3660 : iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
37 1809 : iface->conf->channel != ap->channel)
38 44 : return 0;
39 :
40 1807 : if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
41 0 : return 1;
42 :
43 8211 : for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
44 8210 : int rate = (ap->supported_rates[i] & 0x7f) * 5;
45 8210 : if (rate == 60 || rate == 90 || rate > 110)
46 1806 : return 0;
47 : }
48 :
49 1 : return 1;
50 : }
51 :
52 :
53 1855 : static struct ap_info * ap_get_ap(struct hostapd_iface *iface, const u8 *ap)
54 : {
55 : struct ap_info *s;
56 :
57 1855 : s = iface->ap_hash[STA_HASH(ap)];
58 3715 : while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
59 5 : s = s->hnext;
60 1855 : return s;
61 : }
62 :
63 :
64 151 : static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
65 : {
66 151 : if (iface->ap_list) {
67 2 : ap->prev = iface->ap_list->prev;
68 2 : iface->ap_list->prev = ap;
69 : } else
70 149 : ap->prev = ap;
71 151 : ap->next = iface->ap_list;
72 151 : iface->ap_list = ap;
73 151 : }
74 :
75 :
76 151 : static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
77 : {
78 151 : if (iface->ap_list == ap)
79 150 : iface->ap_list = ap->next;
80 : else
81 1 : ap->prev->next = ap->next;
82 :
83 151 : if (ap->next)
84 1 : ap->next->prev = ap->prev;
85 150 : else if (iface->ap_list)
86 1 : iface->ap_list->prev = ap->prev;
87 151 : }
88 :
89 :
90 150 : static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
91 : {
92 150 : ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
93 150 : iface->ap_hash[STA_HASH(ap->addr)] = ap;
94 150 : }
95 :
96 :
97 150 : static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
98 : {
99 : struct ap_info *s;
100 :
101 150 : s = iface->ap_hash[STA_HASH(ap->addr)];
102 150 : if (s == NULL) return;
103 150 : if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
104 149 : iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
105 149 : return;
106 : }
107 :
108 3 : while (s->hnext != NULL &&
109 1 : os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
110 0 : s = s->hnext;
111 1 : if (s->hnext != NULL)
112 1 : s->hnext = s->hnext->hnext;
113 : else
114 0 : printf("AP: could not remove AP " MACSTR " from hash table\n",
115 0 : MAC2STR(ap->addr));
116 : }
117 :
118 :
119 150 : static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
120 : {
121 150 : ap_ap_hash_del(iface, ap);
122 150 : ap_ap_list_del(iface, ap);
123 :
124 150 : iface->num_ap--;
125 150 : os_free(ap);
126 150 : }
127 :
128 :
129 691 : static void hostapd_free_aps(struct hostapd_iface *iface)
130 : {
131 : struct ap_info *ap, *prev;
132 :
133 691 : ap = iface->ap_list;
134 :
135 1531 : while (ap) {
136 149 : prev = ap;
137 149 : ap = ap->next;
138 149 : ap_free_ap(iface, prev);
139 : }
140 :
141 691 : iface->ap_list = NULL;
142 691 : }
143 :
144 :
145 150 : static struct ap_info * ap_ap_add(struct hostapd_iface *iface, const u8 *addr)
146 : {
147 : struct ap_info *ap;
148 :
149 150 : ap = os_zalloc(sizeof(struct ap_info));
150 150 : if (ap == NULL)
151 0 : return NULL;
152 :
153 : /* initialize AP info data */
154 150 : os_memcpy(ap->addr, addr, ETH_ALEN);
155 150 : ap_ap_list_add(iface, ap);
156 150 : iface->num_ap++;
157 150 : ap_ap_hash_add(iface, ap);
158 :
159 150 : if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
160 0 : wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
161 0 : MACSTR " from AP table", MAC2STR(ap->prev->addr));
162 0 : ap_free_ap(iface, ap->prev);
163 : }
164 :
165 150 : return ap;
166 : }
167 :
168 :
169 1855 : 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 1855 : int new_ap = 0;
176 1855 : int set_beacon = 0;
177 :
178 1855 : if (iface->conf->ap_table_max_size < 1)
179 0 : return;
180 :
181 1855 : ap = ap_get_ap(iface, mgmt->bssid);
182 1855 : if (!ap) {
183 150 : ap = ap_ap_add(iface, mgmt->bssid);
184 150 : if (!ap) {
185 0 : printf("Failed to allocate AP information entry\n");
186 0 : return;
187 : }
188 150 : new_ap = 1;
189 : }
190 :
191 3710 : merge_byte_arrays(ap->supported_rates, WLAN_SUPP_RATES_MAX,
192 1855 : elems->supp_rates, elems->supp_rates_len,
193 1855 : elems->ext_supp_rates, elems->ext_supp_rates_len);
194 :
195 1855 : if (elems->erp_info && elems->erp_info_len == 1)
196 1813 : ap->erp = elems->erp_info[0];
197 : else
198 42 : ap->erp = -1;
199 :
200 1855 : if (elems->ds_params && elems->ds_params_len == 1)
201 1855 : ap->channel = elems->ds_params[0];
202 0 : else if (elems->ht_operation && elems->ht_operation_len >= 1)
203 0 : ap->channel = elems->ht_operation[0];
204 0 : else if (fi)
205 0 : ap->channel = fi->channel;
206 :
207 1855 : if (elems->ht_capabilities)
208 1843 : ap->ht_support = 1;
209 : else
210 12 : ap->ht_support = 0;
211 :
212 1855 : os_get_reltime(&ap->last_beacon);
213 :
214 1855 : if (!new_ap && ap != iface->ap_list) {
215 : /* move AP entry into the beginning of the list so that the
216 : * oldest entry is always in the end of the list */
217 1 : ap_ap_list_del(iface, ap);
218 1 : ap_ap_list_add(iface, ap);
219 : }
220 :
221 3706 : if (!iface->olbc &&
222 1851 : ap_list_beacon_olbc(iface, ap)) {
223 1 : iface->olbc = 1;
224 7 : wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR
225 : " (channel %d) - enable protection",
226 6 : MAC2STR(ap->addr), ap->channel);
227 1 : set_beacon++;
228 : }
229 :
230 : #ifdef CONFIG_IEEE80211N
231 1858 : if (!iface->olbc_ht && !ap->ht_support &&
232 6 : (ap->channel == 0 ||
233 4 : ap->channel == iface->conf->channel ||
234 2 : ap->channel == iface->conf->channel +
235 1 : iface->conf->secondary_channel * 4)) {
236 2 : iface->olbc_ht = 1;
237 2 : hostapd_ht_operation_update(iface);
238 14 : wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
239 : " (channel %d) - enable protection",
240 12 : MAC2STR(ap->addr), ap->channel);
241 2 : set_beacon++;
242 : }
243 : #endif /* CONFIG_IEEE80211N */
244 :
245 1855 : if (set_beacon)
246 2 : ieee802_11_update_beacons(iface);
247 : }
248 :
249 :
250 531 : static void ap_list_timer(void *eloop_ctx, void *timeout_ctx)
251 : {
252 531 : struct hostapd_iface *iface = eloop_ctx;
253 : struct os_reltime now;
254 : struct ap_info *ap;
255 531 : int set_beacon = 0;
256 :
257 531 : eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
258 :
259 531 : if (!iface->ap_list)
260 1061 : return;
261 :
262 1 : os_get_reltime(&now);
263 :
264 3 : while (iface->ap_list) {
265 1 : ap = iface->ap_list->prev;
266 1 : if (!os_reltime_expired(&now, &ap->last_beacon,
267 1 : iface->conf->ap_table_expiration_time))
268 0 : break;
269 :
270 1 : ap_free_ap(iface, ap);
271 : }
272 :
273 1 : if (iface->olbc || iface->olbc_ht) {
274 1 : int olbc = 0;
275 1 : int olbc_ht = 0;
276 :
277 1 : ap = iface->ap_list;
278 2 : while (ap && (olbc == 0 || olbc_ht == 0)) {
279 0 : if (ap_list_beacon_olbc(iface, ap))
280 0 : olbc = 1;
281 0 : if (!ap->ht_support)
282 0 : olbc_ht = 1;
283 0 : ap = ap->next;
284 : }
285 1 : if (!olbc && iface->olbc) {
286 1 : wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
287 1 : iface->olbc = 0;
288 1 : set_beacon++;
289 : }
290 : #ifdef CONFIG_IEEE80211N
291 1 : if (!olbc_ht && iface->olbc_ht) {
292 1 : wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
293 1 : iface->olbc_ht = 0;
294 1 : hostapd_ht_operation_update(iface);
295 1 : set_beacon++;
296 : }
297 : #endif /* CONFIG_IEEE80211N */
298 : }
299 :
300 1 : if (set_beacon)
301 1 : ieee802_11_update_beacons(iface);
302 : }
303 :
304 :
305 661 : int ap_list_init(struct hostapd_iface *iface)
306 : {
307 661 : eloop_register_timeout(10, 0, ap_list_timer, iface, NULL);
308 661 : return 0;
309 : }
310 :
311 :
312 691 : void ap_list_deinit(struct hostapd_iface *iface)
313 : {
314 691 : eloop_cancel_timeout(ap_list_timer, iface, NULL);
315 691 : hostapd_free_aps(iface);
316 691 : }
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