aboutsummaryrefslogtreecommitdiffstats
path: root/src/ap/ap_list.c
blob: 8bf6ddec8d3756e5d0aef3cb6ed99892677886f5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
/*
 * hostapd / AP table
 * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
 * Copyright (c) 2003-2004, Instant802 Networks, Inc.
 * Copyright (c) 2006, Devicescape Software, Inc.
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "utils/includes.h"

#include "utils/common.h"
#include "utils/eloop.h"
#include "common/ieee802_11_defs.h"
#include "common/ieee802_11_common.h"
#include "hostapd.h"
#include "ap_config.h"
#include "ieee802_11.h"
#include "sta_info.h"
#include "beacon.h"
#include "ap_list.h"


/* AP list is a double linked list with head->prev pointing to the end of the
 * list and tail->next = NULL. Entries are moved to the head of the list
 * whenever a beacon has been received from the AP in question. The tail entry
 * in this link will thus be the least recently used entry. */


static int ap_list_beacon_olbc(struct hostapd_iface *iface, struct ap_info *ap)
{
	int i;

	if (iface->current_mode == NULL ||
	    iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G ||
	    iface->conf->channel != ap->channel)
		return 0;

	if (ap->erp != -1 && (ap->erp & ERP_INFO_NON_ERP_PRESENT))
		return 1;

	for (i = 0; i < WLAN_SUPP_RATES_MAX; i++) {
		int rate = (ap->supported_rates[i] & 0x7f) * 5;
		if (rate == 60 || rate == 90 || rate > 110)
			return 0;
	}

	return 1;
}


static struct ap_info * ap_get_ap(struct hostapd_iface *iface, const u8 *ap)
{
	struct ap_info *s;

	s = iface->ap_hash[STA_HASH(ap)];
	while (s != NULL && os_memcmp(s->addr, ap, ETH_ALEN) != 0)
		s = s->hnext;
	return s;
}


static void ap_ap_list_add(struct hostapd_iface *iface, struct ap_info *ap)
{
	if (iface->ap_list) {
		ap->prev = iface->ap_list->prev;
		iface->ap_list->prev = ap;
	} else
		ap->prev = ap;
	ap->next = iface->ap_list;
	iface->ap_list = ap;
}


static void ap_ap_list_del(struct hostapd_iface *iface, struct ap_info *ap)
{
	if (iface->ap_list == ap)
		iface->ap_list = ap->next;
	else
		ap->prev->next = ap->next;

	if (ap->next)
		ap->next->prev = ap->prev;
	else if (iface->ap_list)
		iface->ap_list->prev = ap->prev;
}


static void ap_ap_hash_add(struct hostapd_iface *iface, struct ap_info *ap)
{
	ap->hnext = iface->ap_hash[STA_HASH(ap->addr)];
	iface->ap_hash[STA_HASH(ap->addr)] = ap;
}


static void ap_ap_hash_del(struct hostapd_iface *iface, struct ap_info *ap)
{
	struct ap_info *s;

	s = iface->ap_hash[STA_HASH(ap->addr)];
	if (s == NULL) return;
	if (os_memcmp(s->addr, ap->addr, ETH_ALEN) == 0) {
		iface->ap_hash[STA_HASH(ap->addr)] = s->hnext;
		return;
	}

	while (s->hnext != NULL &&
	       os_memcmp(s->hnext->addr, ap->addr, ETH_ALEN) != 0)
		s = s->hnext;
	if (s->hnext != NULL)
		s->hnext = s->hnext->hnext;
	else
		wpa_printf(MSG_INFO, "AP: could not remove AP " MACSTR
			   " from hash table",  MAC2STR(ap->addr));
}


static void ap_free_ap(struct hostapd_iface *iface, struct ap_info *ap)
{
	ap_ap_hash_del(iface, ap);
	ap_ap_list_del(iface, ap);

	iface->num_ap--;
	os_free(ap);
}


static void hostapd_free_aps(struct hostapd_iface *iface)
{
	struct ap_info *ap, *prev;

	ap = iface->ap_list;

	while (ap) {
		prev = ap;
		ap = ap->next;
		ap_free_ap(iface, prev);
	}

	iface->ap_list = NULL;
}


static struct ap_info * ap_ap_add(struct hostapd_iface *iface, const u8 *addr)
{
	struct ap_info *ap;

	ap = os_zalloc(sizeof(struct ap_info));
	if (ap == NULL)
		return NULL;

	/* initialize AP info data */
	os_memcpy(ap->addr, addr, ETH_ALEN);
	ap_ap_list_add(iface, ap);
	iface->num_ap++;
	ap_ap_hash_add(iface, ap);

	if (iface->num_ap > iface->conf->ap_table_max_size && ap != ap->prev) {
		wpa_printf(MSG_DEBUG, "Removing the least recently used AP "
			   MACSTR " from AP table", MAC2STR(ap->prev->addr));
		ap_free_ap(iface, ap->prev);
	}

	return ap;
}


void ap_list_process_beacon(struct hostapd_iface *iface,
			    const struct ieee80211_mgmt *mgmt,
			    struct ieee802_11_elems *elems,
			    struct hostapd_frame_info *fi)
{
	struct ap_info *ap;
	int new_ap = 0;
	int set_beacon = 0;

	if (iface->conf->ap_table_max_size < 1)
		return;

	ap = ap_get_ap(iface, mgmt->bssid);
	if (!ap) {
		ap = ap_ap_add(iface, mgmt->bssid);
		if (!ap) {
			wpa_printf(MSG_INFO,
				   "Failed to allocate AP information entry");
			return;
		}
		new_ap = 1;
	}

	merge_byte_arrays(ap->supported_rates, WLAN_SUPP_RATES_MAX,
			  elems->supp_rates, elems->supp_rates_len,
			  elems->ext_supp_rates, elems->ext_supp_rates_len);

	if (elems->erp_info)
		ap->erp = elems->erp_info[0];
	else
		ap->erp = -1;

	if (elems->ds_params)
		ap->channel = elems->ds_params[0];
	else if (elems->ht_operation)
		ap->channel = elems->ht_operation[0];
	else if (fi)
		ap->channel = fi->channel;

	if (elems->ht_capabilities)
		ap->ht_support = 1;
	else
		ap->ht_support = 0;

	os_get_reltime(&ap->last_beacon);

	if (!new_ap && ap != iface->ap_list) {
		/* move AP entry into the beginning of the list so that the
		 * oldest entry is always in the end of the list */
		ap_ap_list_del(iface, ap);
		ap_ap_list_add(iface, ap);
	}

	if (!iface->olbc &&
	    ap_list_beacon_olbc(iface, ap)) {
		iface->olbc = 1;
		wpa_printf(MSG_DEBUG, "OLBC AP detected: " MACSTR
			   " (channel %d) - enable protection",
			   MAC2STR(ap->addr), ap->channel);
		set_beacon++;
	}

#ifdef CONFIG_IEEE80211N
	if (!iface->olbc_ht && !ap->ht_support &&
	    (ap->channel == 0 ||
	     ap->channel == iface->conf->channel ||
	     ap->channel == iface->conf->channel +
	     iface->conf->secondary_channel * 4)) {
		iface->olbc_ht = 1;
		hostapd_ht_operation_update(iface);
		wpa_printf(MSG_DEBUG, "OLBC HT AP detected: " MACSTR
			   " (channel %d) - enable protection",
			   MAC2STR(ap->addr), ap->channel);
		set_beacon++;
	}
#endif /* CONFIG_IEEE80211N */

	if (set_beacon)
		ieee802_11_update_beacons(iface);
}


void ap_list_timer(struct hostapd_iface *iface)
{
	struct os_reltime now;
	struct ap_info *ap;
	int set_beacon = 0;

	if (!iface->ap_list)
		return;

	os_get_reltime(&now);

	while (iface->ap_list) {
		ap = iface->ap_list->prev;
		if (!os_reltime_expired(&now, &ap->last_beacon,
					iface->conf->ap_table_expiration_time))
			break;

		ap_free_ap(iface, ap);
	}

	if (iface->olbc || iface->olbc_ht) {
		int olbc = 0;
		int olbc_ht = 0;

		ap = iface->ap_list;
		while (ap && (olbc == 0 || olbc_ht == 0)) {
			if (ap_list_beacon_olbc(iface, ap))
				olbc = 1;
			if (!ap->ht_support)
				olbc_ht = 1;
			ap = ap->next;
		}
		if (!olbc && iface->olbc) {
			wpa_printf(MSG_DEBUG, "OLBC not detected anymore");
			iface->olbc = 0;
			set_beacon++;
		}
#ifdef CONFIG_IEEE80211N
		if (!olbc_ht && iface->olbc_ht) {
			wpa_printf(MSG_DEBUG, "OLBC HT not detected anymore");
			iface->olbc_ht = 0;
			hostapd_ht_operation_update(iface);
			set_beacon++;
		}
#endif /* CONFIG_IEEE80211N */
	}

	if (set_beacon)
		ieee802_11_update_beacons(iface);
}


int ap_list_init(struct hostapd_iface *iface)
{
	return 0;
}


void ap_list_deinit(struct hostapd_iface *iface)
{
	hostapd_free_aps(iface);
}