3 * Copyright (c) 2009-2010, Jouni Malinen <j@w1.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
15 #include "utils/includes.h"
17 #include "utils/common.h"
18 #include "utils/eloop.h"
19 #include "common/ieee802_11_defs.h"
20 #include "drivers/driver.h"
21 #include "wpa_supplicant_i.h"
29 * WPA_BSS_EXPIRATION_PERIOD - Period of expiration run in seconds
31 #define WPA_BSS_EXPIRATION_PERIOD 10
34 * WPA_BSS_EXPIRATION_AGE - BSS entry age after which it can be expired
36 * This value control the time in seconds after which a BSS entry gets removed
37 * if it has not been updated or is not in use.
39 #define WPA_BSS_EXPIRATION_AGE 180
42 * WPA_BSS_EXPIRATION_SCAN_COUNT - Expire BSS after number of scans
44 * If the BSS entry has not been seen in this many scans, it will be removed.
45 * Value 1 means that the entry is removed after the first scan without the
46 * BSSID being seen. Larger values can be used to avoid BSS entries
47 * disappearing if they are not visible in every scan (e.g., low signal quality
50 #define WPA_BSS_EXPIRATION_SCAN_COUNT 2
52 #define WPA_BSS_FREQ_CHANGED_FLAG BIT(0)
53 #define WPA_BSS_SIGNAL_CHANGED_FLAG BIT(1)
54 #define WPA_BSS_PRIVACY_CHANGED_FLAG BIT(2)
55 #define WPA_BSS_MODE_CHANGED_FLAG BIT(3)
56 #define WPA_BSS_WPAIE_CHANGED_FLAG BIT(4)
57 #define WPA_BSS_RSNIE_CHANGED_FLAG BIT(5)
58 #define WPA_BSS_WPS_CHANGED_FLAG BIT(6)
59 #define WPA_BSS_RATES_CHANGED_FLAG BIT(7)
60 #define WPA_BSS_IES_CHANGED_FLAG BIT(8)
63 static void wpa_bss_remove(struct wpa_supplicant
*wpa_s
, struct wpa_bss
*bss
)
65 dl_list_del(&bss
->list
);
66 dl_list_del(&bss
->list_id
);
68 wpa_printf(MSG_DEBUG
, "BSS: Remove id %u BSSID " MACSTR
" SSID '%s'",
69 bss
->id
, MAC2STR(bss
->bssid
),
70 wpa_ssid_txt(bss
->ssid
, bss
->ssid_len
));
71 wpas_notify_bss_removed(wpa_s
, bss
->bssid
, bss
->id
);
76 struct wpa_bss
* wpa_bss_get(struct wpa_supplicant
*wpa_s
, const u8
*bssid
,
77 const u8
*ssid
, size_t ssid_len
)
80 dl_list_for_each(bss
, &wpa_s
->bss
, struct wpa_bss
, list
) {
81 if (os_memcmp(bss
->bssid
, bssid
, ETH_ALEN
) == 0 &&
82 bss
->ssid_len
== ssid_len
&&
83 os_memcmp(bss
->ssid
, ssid
, ssid_len
) == 0)
90 static void wpa_bss_copy_res(struct wpa_bss
*dst
, struct wpa_scan_res
*src
)
94 dst
->flags
= src
->flags
;
95 os_memcpy(dst
->bssid
, src
->bssid
, ETH_ALEN
);
96 dst
->freq
= src
->freq
;
97 dst
->beacon_int
= src
->beacon_int
;
98 dst
->caps
= src
->caps
;
99 dst
->qual
= src
->qual
;
100 dst
->noise
= src
->noise
;
101 dst
->level
= src
->level
;
104 os_get_time(&dst
->last_update
);
105 dst
->last_update
.sec
-= src
->age
/ 1000;
106 usec
= (src
->age
% 1000) * 1000;
107 if (dst
->last_update
.usec
< usec
) {
108 dst
->last_update
.sec
--;
109 dst
->last_update
.usec
+= 1000000;
111 dst
->last_update
.usec
-= usec
;
115 static void wpa_bss_add(struct wpa_supplicant
*wpa_s
,
116 const u8
*ssid
, size_t ssid_len
,
117 struct wpa_scan_res
*res
)
121 bss
= os_zalloc(sizeof(*bss
) + res
->ie_len
+ res
->beacon_ie_len
);
124 bss
->id
= wpa_s
->bss_next_id
++;
125 bss
->last_update_idx
= wpa_s
->bss_update_idx
;
126 wpa_bss_copy_res(bss
, res
);
127 os_memcpy(bss
->ssid
, ssid
, ssid_len
);
128 bss
->ssid_len
= ssid_len
;
129 bss
->ie_len
= res
->ie_len
;
130 bss
->beacon_ie_len
= res
->beacon_ie_len
;
131 os_memcpy(bss
+ 1, res
+ 1, res
->ie_len
+ res
->beacon_ie_len
);
133 dl_list_add_tail(&wpa_s
->bss
, &bss
->list
);
134 dl_list_add_tail(&wpa_s
->bss_id
, &bss
->list_id
);
136 wpa_printf(MSG_DEBUG
, "BSS: Add new id %u BSSID " MACSTR
" SSID '%s'",
137 bss
->id
, MAC2STR(bss
->bssid
), wpa_ssid_txt(ssid
, ssid_len
));
138 wpas_notify_bss_added(wpa_s
, bss
->bssid
, bss
->id
);
139 if (wpa_s
->num_bss
> wpa_s
->conf
->bss_max_count
) {
140 /* Remove the oldest entry */
141 wpa_bss_remove(wpa_s
, dl_list_first(&wpa_s
->bss
,
142 struct wpa_bss
, list
));
147 static int are_ies_equal(const struct wpa_bss
*old
,
148 const struct wpa_scan_res
*new, u32 ie
)
150 const u8
*old_ie
, *new_ie
;
151 struct wpabuf
*old_ie_buff
= NULL
;
152 struct wpabuf
*new_ie_buff
= NULL
;
153 int new_ie_len
, old_ie_len
, ret
, is_multi
;
156 case WPA_IE_VENDOR_TYPE
:
157 old_ie
= wpa_bss_get_vendor_ie(old
, ie
);
158 new_ie
= wpa_scan_get_vendor_ie(new, ie
);
161 case WPS_IE_VENDOR_TYPE
:
162 old_ie_buff
= wpa_bss_get_vendor_ie_multi(old
, ie
);
163 new_ie_buff
= wpa_scan_get_vendor_ie_multi(new, ie
);
167 case WLAN_EID_SUPP_RATES
:
168 case WLAN_EID_EXT_SUPP_RATES
:
169 old_ie
= wpa_bss_get_ie(old
, ie
);
170 new_ie
= wpa_scan_get_ie(new, ie
);
174 wpa_printf(MSG_DEBUG
, "bss: %s: cannot compare IEs", __func__
);
179 /* in case of multiple IEs stored in buffer */
180 old_ie
= old_ie_buff
? wpabuf_head_u8(old_ie_buff
) : NULL
;
181 new_ie
= new_ie_buff
? wpabuf_head_u8(new_ie_buff
) : NULL
;
182 old_ie_len
= old_ie_buff
? wpabuf_len(old_ie_buff
) : 0;
183 new_ie_len
= new_ie_buff
? wpabuf_len(new_ie_buff
) : 0;
185 /* in case of single IE */
186 old_ie_len
= old_ie
? old_ie
[1] + 2 : 0;
187 new_ie_len
= new_ie
? new_ie
[1] + 2 : 0;
190 ret
= (old_ie_len
== new_ie_len
&&
191 os_memcmp(old_ie
, new_ie
, old_ie_len
) == 0);
193 wpabuf_free(old_ie_buff
);
194 wpabuf_free(new_ie_buff
);
200 static u32
wpa_bss_compare_res(const struct wpa_bss
*old
,
201 const struct wpa_scan_res
*new)
204 int caps_diff
= old
->caps
^ new->caps
;
206 if (old
->freq
!= new->freq
)
207 changes
|= WPA_BSS_FREQ_CHANGED_FLAG
;
209 if (old
->level
!= new->level
)
210 changes
|= WPA_BSS_SIGNAL_CHANGED_FLAG
;
212 if (caps_diff
& IEEE80211_CAP_PRIVACY
)
213 changes
|= WPA_BSS_PRIVACY_CHANGED_FLAG
;
215 if (caps_diff
& IEEE80211_CAP_IBSS
)
216 changes
|= WPA_BSS_MODE_CHANGED_FLAG
;
218 if (old
->ie_len
== new->ie_len
&&
219 os_memcmp(old
+ 1, new + 1, old
->ie_len
) == 0)
221 changes
|= WPA_BSS_IES_CHANGED_FLAG
;
223 if (!are_ies_equal(old
, new, WPA_IE_VENDOR_TYPE
))
224 changes
|= WPA_BSS_WPAIE_CHANGED_FLAG
;
226 if (!are_ies_equal(old
, new, WLAN_EID_RSN
))
227 changes
|= WPA_BSS_RSNIE_CHANGED_FLAG
;
229 if (!are_ies_equal(old
, new, WPS_IE_VENDOR_TYPE
))
230 changes
|= WPA_BSS_WPS_CHANGED_FLAG
;
232 if (!are_ies_equal(old
, new, WLAN_EID_SUPP_RATES
) ||
233 !are_ies_equal(old
, new, WLAN_EID_EXT_SUPP_RATES
))
234 changes
|= WPA_BSS_RATES_CHANGED_FLAG
;
240 static void notify_bss_changes(struct wpa_supplicant
*wpa_s
, u32 changes
,
241 const struct wpa_bss
*bss
)
243 if (changes
& WPA_BSS_FREQ_CHANGED_FLAG
)
244 wpas_notify_bss_freq_changed(wpa_s
, bss
->id
);
246 if (changes
& WPA_BSS_SIGNAL_CHANGED_FLAG
)
247 wpas_notify_bss_signal_changed(wpa_s
, bss
->id
);
249 if (changes
& WPA_BSS_PRIVACY_CHANGED_FLAG
)
250 wpas_notify_bss_privacy_changed(wpa_s
, bss
->id
);
252 if (changes
& WPA_BSS_MODE_CHANGED_FLAG
)
253 wpas_notify_bss_mode_changed(wpa_s
, bss
->id
);
255 if (changes
& WPA_BSS_WPAIE_CHANGED_FLAG
)
256 wpas_notify_bss_wpaie_changed(wpa_s
, bss
->id
);
258 if (changes
& WPA_BSS_RSNIE_CHANGED_FLAG
)
259 wpas_notify_bss_rsnie_changed(wpa_s
, bss
->id
);
261 if (changes
& WPA_BSS_WPS_CHANGED_FLAG
)
262 wpas_notify_bss_wps_changed(wpa_s
, bss
->id
);
264 if (changes
& WPA_BSS_IES_CHANGED_FLAG
)
265 wpas_notify_bss_ies_changed(wpa_s
, bss
->id
);
267 if (changes
& WPA_BSS_RATES_CHANGED_FLAG
)
268 wpas_notify_bss_rates_changed(wpa_s
, bss
->id
);
272 static void wpa_bss_update(struct wpa_supplicant
*wpa_s
, struct wpa_bss
*bss
,
273 struct wpa_scan_res
*res
)
277 changes
= wpa_bss_compare_res(bss
, res
);
278 bss
->scan_miss_count
= 0;
279 bss
->last_update_idx
= wpa_s
->bss_update_idx
;
280 wpa_bss_copy_res(bss
, res
);
281 /* Move the entry to the end of the list */
282 dl_list_del(&bss
->list
);
283 if (bss
->ie_len
+ bss
->beacon_ie_len
>=
284 res
->ie_len
+ res
->beacon_ie_len
) {
285 os_memcpy(bss
+ 1, res
+ 1, res
->ie_len
+ res
->beacon_ie_len
);
286 bss
->ie_len
= res
->ie_len
;
287 bss
->beacon_ie_len
= res
->beacon_ie_len
;
289 struct wpa_bss
*nbss
;
290 struct dl_list
*prev
= bss
->list_id
.prev
;
291 dl_list_del(&bss
->list_id
);
292 nbss
= os_realloc(bss
, sizeof(*bss
) + res
->ie_len
+
296 os_memcpy(bss
+ 1, res
+ 1,
297 res
->ie_len
+ res
->beacon_ie_len
);
298 bss
->ie_len
= res
->ie_len
;
299 bss
->beacon_ie_len
= res
->beacon_ie_len
;
301 dl_list_add(prev
, &bss
->list_id
);
303 dl_list_add_tail(&wpa_s
->bss
, &bss
->list
);
305 notify_bss_changes(wpa_s
, changes
, bss
);
309 static int wpa_bss_in_use(struct wpa_supplicant
*wpa_s
, struct wpa_bss
*bss
)
311 return bss
== wpa_s
->current_bss
||
312 os_memcmp(bss
->bssid
, wpa_s
->bssid
, ETH_ALEN
) == 0 ||
313 os_memcmp(bss
->bssid
, wpa_s
->pending_bssid
, ETH_ALEN
) == 0;
317 void wpa_bss_update_start(struct wpa_supplicant
*wpa_s
)
319 wpa_s
->bss_update_idx
++;
320 wpa_printf(MSG_DEBUG
, "BSS: Start scan result update %u",
321 wpa_s
->bss_update_idx
);
325 void wpa_bss_update_scan_res(struct wpa_supplicant
*wpa_s
,
326 struct wpa_scan_res
*res
)
331 ssid
= wpa_scan_get_ie(res
, WLAN_EID_SSID
);
333 wpa_printf(MSG_DEBUG
, "BSS: No SSID IE included for " MACSTR
,
334 MAC2STR(res
->bssid
));
338 wpa_printf(MSG_DEBUG
, "BSS: Too long SSID IE included for "
339 MACSTR
, MAC2STR(res
->bssid
));
343 /* TODO: add option for ignoring BSSes we are not interested in
344 * (to save memory) */
345 bss
= wpa_bss_get(wpa_s
, res
->bssid
, ssid
+ 2, ssid
[1]);
347 wpa_bss_add(wpa_s
, ssid
+ 2, ssid
[1], res
);
349 wpa_bss_update(wpa_s
, bss
, res
);
353 static int wpa_bss_included_in_scan(const struct wpa_bss
*bss
,
354 const struct scan_info
*info
)
362 if (info
->num_freqs
) {
364 for (i
= 0; i
< info
->num_freqs
; i
++) {
365 if (bss
->freq
== info
->freqs
[i
]) {
374 if (info
->num_ssids
) {
376 for (i
= 0; i
< info
->num_ssids
; i
++) {
377 const struct wpa_driver_scan_ssid
*s
= &info
->ssids
[i
];
378 if ((s
->ssid
== NULL
|| s
->ssid_len
== 0) ||
379 (s
->ssid_len
== bss
->ssid_len
&&
380 os_memcmp(s
->ssid
, bss
->ssid
, bss
->ssid_len
) ==
394 void wpa_bss_update_end(struct wpa_supplicant
*wpa_s
, struct scan_info
*info
,
397 struct wpa_bss
*bss
, *n
;
400 return; /* do not expire entries without new scan */
402 dl_list_for_each_safe(bss
, n
, &wpa_s
->bss
, struct wpa_bss
, list
) {
403 if (wpa_bss_in_use(wpa_s
, bss
))
405 if (!wpa_bss_included_in_scan(bss
, info
))
406 continue; /* expire only BSSes that were scanned */
407 if (bss
->last_update_idx
< wpa_s
->bss_update_idx
)
408 bss
->scan_miss_count
++;
409 if (bss
->scan_miss_count
>= WPA_BSS_EXPIRATION_SCAN_COUNT
) {
410 wpa_printf(MSG_DEBUG
, "BSS: Expire BSS %u due to no "
411 "match in scan", bss
->id
);
412 wpa_bss_remove(wpa_s
, bss
);
418 static void wpa_bss_timeout(void *eloop_ctx
, void *timeout_ctx
)
420 struct wpa_supplicant
*wpa_s
= eloop_ctx
;
421 struct wpa_bss
*bss
, *n
;
424 if (dl_list_empty(&wpa_s
->bss
))
428 t
.sec
-= WPA_BSS_EXPIRATION_AGE
;
430 dl_list_for_each_safe(bss
, n
, &wpa_s
->bss
, struct wpa_bss
, list
) {
431 if (wpa_bss_in_use(wpa_s
, bss
))
434 if (os_time_before(&bss
->last_update
, &t
)) {
435 wpa_printf(MSG_DEBUG
, "BSS: Expire BSS %u due to age",
437 wpa_bss_remove(wpa_s
, bss
);
441 eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD
, 0,
442 wpa_bss_timeout
, wpa_s
, NULL
);
446 int wpa_bss_init(struct wpa_supplicant
*wpa_s
)
448 dl_list_init(&wpa_s
->bss
);
449 dl_list_init(&wpa_s
->bss_id
);
450 eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD
, 0,
451 wpa_bss_timeout
, wpa_s
, NULL
);
456 void wpa_bss_deinit(struct wpa_supplicant
*wpa_s
)
458 struct wpa_bss
*bss
, *n
;
459 eloop_cancel_timeout(wpa_bss_timeout
, wpa_s
, NULL
);
460 if (wpa_s
->bss
.next
== NULL
)
461 return; /* BSS table not yet initialized */
462 dl_list_for_each_safe(bss
, n
, &wpa_s
->bss
, struct wpa_bss
, list
)
463 wpa_bss_remove(wpa_s
, bss
);
467 struct wpa_bss
* wpa_bss_get_bssid(struct wpa_supplicant
*wpa_s
,
471 dl_list_for_each(bss
, &wpa_s
->bss
, struct wpa_bss
, list
) {
472 if (os_memcmp(bss
->bssid
, bssid
, ETH_ALEN
) == 0)
479 struct wpa_bss
* wpa_bss_get_id(struct wpa_supplicant
*wpa_s
, unsigned int id
)
482 dl_list_for_each(bss
, &wpa_s
->bss
, struct wpa_bss
, list
) {
490 const u8
* wpa_bss_get_ie(const struct wpa_bss
*bss
, u8 ie
)
494 pos
= (const u8
*) (bss
+ 1);
495 end
= pos
+ bss
->ie_len
;
497 while (pos
+ 1 < end
) {
498 if (pos
+ 2 + pos
[1] > end
)
509 const u8
* wpa_bss_get_vendor_ie(const struct wpa_bss
*bss
, u32 vendor_type
)
513 pos
= (const u8
*) (bss
+ 1);
514 end
= pos
+ bss
->ie_len
;
516 while (pos
+ 1 < end
) {
517 if (pos
+ 2 + pos
[1] > end
)
519 if (pos
[0] == WLAN_EID_VENDOR_SPECIFIC
&& pos
[1] >= 4 &&
520 vendor_type
== WPA_GET_BE32(&pos
[2]))
529 struct wpabuf
* wpa_bss_get_vendor_ie_multi(const struct wpa_bss
*bss
,
535 buf
= wpabuf_alloc(bss
->ie_len
);
539 pos
= (const u8
*) (bss
+ 1);
540 end
= pos
+ bss
->ie_len
;
542 while (pos
+ 1 < end
) {
543 if (pos
+ 2 + pos
[1] > end
)
545 if (pos
[0] == WLAN_EID_VENDOR_SPECIFIC
&& pos
[1] >= 4 &&
546 vendor_type
== WPA_GET_BE32(&pos
[2]))
547 wpabuf_put_data(buf
, pos
+ 2 + 4, pos
[1] - 4);
551 if (wpabuf_len(buf
) == 0) {
560 int wpa_bss_get_max_rate(const struct wpa_bss
*bss
)
566 ie
= wpa_bss_get_ie(bss
, WLAN_EID_SUPP_RATES
);
567 for (i
= 0; ie
&& i
< ie
[1]; i
++) {
568 if ((ie
[i
+ 2] & 0x7f) > rate
)
569 rate
= ie
[i
+ 2] & 0x7f;
572 ie
= wpa_bss_get_ie(bss
, WLAN_EID_EXT_SUPP_RATES
);
573 for (i
= 0; ie
&& i
< ie
[1]; i
++) {
574 if ((ie
[i
+ 2] & 0x7f) > rate
)
575 rate
= ie
[i
+ 2] & 0x7f;
582 int wpa_bss_get_bit_rates(const struct wpa_bss
*bss
, u8
**rates
)
589 ie
= wpa_bss_get_ie(bss
, WLAN_EID_SUPP_RATES
);
590 ie2
= wpa_bss_get_ie(bss
, WLAN_EID_EXT_SUPP_RATES
);
592 len
= (ie
? ie
[1] : 0) + (ie2
? ie2
[1] : 0);
598 for (i
= 0; ie
&& i
< ie
[1]; i
++)
599 r
[i
] = ie
[i
+ 2] & 0x7f;
601 for (j
= 0; ie2
&& j
< ie2
[1]; j
++)
602 r
[i
+ j
] = ie2
[j
+ 2] & 0x7f;