1/*
2 * BSS table
3 * Copyright (c) 2009-2015, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9#include "utils/includes.h"
10
11#include "utils/common.h"
12#include "utils/eloop.h"
13#include "common/ieee802_11_defs.h"
14#include "drivers/driver.h"
15#include "wpa_supplicant_i.h"
16#include "config.h"
17#include "notify.h"
18#include "scan.h"
19#include "bss.h"
20
21
22/**
23 * WPA_BSS_EXPIRATION_PERIOD - Period of expiration run in seconds
24 */
25#define WPA_BSS_EXPIRATION_PERIOD 10
26
27#define WPA_BSS_FREQ_CHANGED_FLAG	BIT(0)
28#define WPA_BSS_SIGNAL_CHANGED_FLAG	BIT(1)
29#define WPA_BSS_PRIVACY_CHANGED_FLAG	BIT(2)
30#define WPA_BSS_MODE_CHANGED_FLAG	BIT(3)
31#define WPA_BSS_WPAIE_CHANGED_FLAG	BIT(4)
32#define WPA_BSS_RSNIE_CHANGED_FLAG	BIT(5)
33#define WPA_BSS_WPS_CHANGED_FLAG	BIT(6)
34#define WPA_BSS_RATES_CHANGED_FLAG	BIT(7)
35#define WPA_BSS_IES_CHANGED_FLAG	BIT(8)
36
37
38static void wpa_bss_set_hessid(struct wpa_bss *bss)
39{
40#ifdef CONFIG_INTERWORKING
41	const u8 *ie = wpa_bss_get_ie(bss, WLAN_EID_INTERWORKING);
42	if (ie == NULL || (ie[1] != 7 && ie[1] != 9)) {
43		os_memset(bss->hessid, 0, ETH_ALEN);
44		return;
45	}
46	if (ie[1] == 7)
47		os_memcpy(bss->hessid, ie + 3, ETH_ALEN);
48	else
49		os_memcpy(bss->hessid, ie + 5, ETH_ALEN);
50#endif /* CONFIG_INTERWORKING */
51}
52
53
54/**
55 * wpa_bss_anqp_alloc - Allocate ANQP data structure for a BSS entry
56 * Returns: Allocated ANQP data structure or %NULL on failure
57 *
58 * The allocated ANQP data structure has its users count set to 1. It may be
59 * shared by multiple BSS entries and each shared entry is freed with
60 * wpa_bss_anqp_free().
61 */
62struct wpa_bss_anqp * wpa_bss_anqp_alloc(void)
63{
64	struct wpa_bss_anqp *anqp;
65	anqp = os_zalloc(sizeof(*anqp));
66	if (anqp == NULL)
67		return NULL;
68	anqp->users = 1;
69	return anqp;
70}
71
72
73/**
74 * wpa_bss_anqp_clone - Clone an ANQP data structure
75 * @anqp: ANQP data structure from wpa_bss_anqp_alloc()
76 * Returns: Cloned ANQP data structure or %NULL on failure
77 */
78static struct wpa_bss_anqp * wpa_bss_anqp_clone(struct wpa_bss_anqp *anqp)
79{
80	struct wpa_bss_anqp *n;
81
82	n = os_zalloc(sizeof(*n));
83	if (n == NULL)
84		return NULL;
85
86#define ANQP_DUP(f) if (anqp->f) n->f = wpabuf_dup(anqp->f)
87#ifdef CONFIG_INTERWORKING
88	ANQP_DUP(capability_list);
89	ANQP_DUP(venue_name);
90	ANQP_DUP(network_auth_type);
91	ANQP_DUP(roaming_consortium);
92	ANQP_DUP(ip_addr_type_availability);
93	ANQP_DUP(nai_realm);
94	ANQP_DUP(anqp_3gpp);
95	ANQP_DUP(domain_name);
96#endif /* CONFIG_INTERWORKING */
97#ifdef CONFIG_HS20
98	ANQP_DUP(hs20_capability_list);
99	ANQP_DUP(hs20_operator_friendly_name);
100	ANQP_DUP(hs20_wan_metrics);
101	ANQP_DUP(hs20_connection_capability);
102	ANQP_DUP(hs20_operating_class);
103	ANQP_DUP(hs20_osu_providers_list);
104#endif /* CONFIG_HS20 */
105#undef ANQP_DUP
106
107	return n;
108}
109
110
111/**
112 * wpa_bss_anqp_unshare_alloc - Unshare ANQP data (if shared) in a BSS entry
113 * @bss: BSS entry
114 * Returns: 0 on success, -1 on failure
115 *
116 * This function ensures the specific BSS entry has an ANQP data structure that
117 * is not shared with any other BSS entry.
118 */
119int wpa_bss_anqp_unshare_alloc(struct wpa_bss *bss)
120{
121	struct wpa_bss_anqp *anqp;
122
123	if (bss->anqp && bss->anqp->users > 1) {
124		/* allocated, but shared - clone an unshared copy */
125		anqp = wpa_bss_anqp_clone(bss->anqp);
126		if (anqp == NULL)
127			return -1;
128		anqp->users = 1;
129		bss->anqp->users--;
130		bss->anqp = anqp;
131		return 0;
132	}
133
134	if (bss->anqp)
135		return 0; /* already allocated and not shared */
136
137	/* not allocated - allocate a new storage area */
138	bss->anqp = wpa_bss_anqp_alloc();
139	return bss->anqp ? 0 : -1;
140}
141
142
143/**
144 * wpa_bss_anqp_free - Free an ANQP data structure
145 * @anqp: ANQP data structure from wpa_bss_anqp_alloc() or wpa_bss_anqp_clone()
146 */
147static void wpa_bss_anqp_free(struct wpa_bss_anqp *anqp)
148{
149	if (anqp == NULL)
150		return;
151
152	anqp->users--;
153	if (anqp->users > 0) {
154		/* Another BSS entry holds a pointer to this ANQP info */
155		return;
156	}
157
158#ifdef CONFIG_INTERWORKING
159	wpabuf_free(anqp->capability_list);
160	wpabuf_free(anqp->venue_name);
161	wpabuf_free(anqp->network_auth_type);
162	wpabuf_free(anqp->roaming_consortium);
163	wpabuf_free(anqp->ip_addr_type_availability);
164	wpabuf_free(anqp->nai_realm);
165	wpabuf_free(anqp->anqp_3gpp);
166	wpabuf_free(anqp->domain_name);
167#endif /* CONFIG_INTERWORKING */
168#ifdef CONFIG_HS20
169	wpabuf_free(anqp->hs20_capability_list);
170	wpabuf_free(anqp->hs20_operator_friendly_name);
171	wpabuf_free(anqp->hs20_wan_metrics);
172	wpabuf_free(anqp->hs20_connection_capability);
173	wpabuf_free(anqp->hs20_operating_class);
174	wpabuf_free(anqp->hs20_osu_providers_list);
175#endif /* CONFIG_HS20 */
176
177	os_free(anqp);
178}
179
180
181static void wpa_bss_update_pending_connect(struct wpa_supplicant *wpa_s,
182					   struct wpa_bss *old_bss,
183					   struct wpa_bss *new_bss)
184{
185	struct wpa_radio_work *work;
186	struct wpa_connect_work *cwork;
187
188	work = radio_work_pending(wpa_s, "sme-connect");
189	if (!work)
190		work = radio_work_pending(wpa_s, "connect");
191	if (!work)
192		return;
193
194	cwork = work->ctx;
195	if (cwork->bss != old_bss)
196		return;
197
198	wpa_printf(MSG_DEBUG,
199		   "Update BSS pointer for the pending connect radio work");
200	cwork->bss = new_bss;
201	if (!new_bss)
202		cwork->bss_removed = 1;
203}
204
205
206static void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
207			   const char *reason)
208{
209	if (wpa_s->last_scan_res) {
210		unsigned int i;
211		for (i = 0; i < wpa_s->last_scan_res_used; i++) {
212			if (wpa_s->last_scan_res[i] == bss) {
213				os_memmove(&wpa_s->last_scan_res[i],
214					   &wpa_s->last_scan_res[i + 1],
215					   (wpa_s->last_scan_res_used - i - 1)
216					   * sizeof(struct wpa_bss *));
217				wpa_s->last_scan_res_used--;
218				break;
219			}
220		}
221	}
222	wpa_bss_update_pending_connect(wpa_s, bss, NULL);
223	dl_list_del(&bss->list);
224	dl_list_del(&bss->list_id);
225	wpa_s->num_bss--;
226	wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Remove id %u BSSID " MACSTR
227		" SSID '%s' due to %s", bss->id, MAC2STR(bss->bssid),
228		wpa_ssid_txt(bss->ssid, bss->ssid_len), reason);
229	wpas_notify_bss_removed(wpa_s, bss->bssid, bss->id);
230	wpa_bss_anqp_free(bss->anqp);
231	os_free(bss);
232}
233
234
235/**
236 * wpa_bss_get - Fetch a BSS table entry based on BSSID and SSID
237 * @wpa_s: Pointer to wpa_supplicant data
238 * @bssid: BSSID
239 * @ssid: SSID
240 * @ssid_len: Length of @ssid
241 * Returns: Pointer to the BSS entry or %NULL if not found
242 */
243struct wpa_bss * wpa_bss_get(struct wpa_supplicant *wpa_s, const u8 *bssid,
244			     const u8 *ssid, size_t ssid_len)
245{
246	struct wpa_bss *bss;
247	if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
248		return NULL;
249	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
250		if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0 &&
251		    bss->ssid_len == ssid_len &&
252		    os_memcmp(bss->ssid, ssid, ssid_len) == 0)
253			return bss;
254	}
255	return NULL;
256}
257
258
259static void calculate_update_time(const struct os_reltime *fetch_time,
260				  unsigned int age_ms,
261				  struct os_reltime *update_time)
262{
263	os_time_t usec;
264
265	update_time->sec = fetch_time->sec;
266	update_time->usec = fetch_time->usec;
267	update_time->sec -= age_ms / 1000;
268	usec = (age_ms % 1000) * 1000;
269	if (update_time->usec < usec) {
270		update_time->sec--;
271		update_time->usec += 1000000;
272	}
273	update_time->usec -= usec;
274}
275
276
277static void wpa_bss_copy_res(struct wpa_bss *dst, struct wpa_scan_res *src,
278			     struct os_reltime *fetch_time)
279{
280	dst->flags = src->flags;
281	os_memcpy(dst->bssid, src->bssid, ETH_ALEN);
282	dst->freq = src->freq;
283	dst->beacon_int = src->beacon_int;
284	dst->caps = src->caps;
285	dst->qual = src->qual;
286	dst->noise = src->noise;
287	dst->level = src->level;
288	dst->tsf = src->tsf;
289	dst->est_throughput = src->est_throughput;
290	dst->snr = src->snr;
291
292	calculate_update_time(fetch_time, src->age, &dst->last_update);
293}
294
295
296static int wpa_bss_known(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
297{
298	struct wpa_ssid *ssid;
299
300	for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
301		if (ssid->ssid == NULL || ssid->ssid_len == 0)
302			continue;
303		if (ssid->ssid_len == bss->ssid_len &&
304		    os_memcmp(ssid->ssid, bss->ssid, ssid->ssid_len) == 0)
305			return 1;
306	}
307
308	return 0;
309}
310
311
312static int wpa_bss_in_use(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
313{
314	return bss == wpa_s->current_bss ||
315		(!is_zero_ether_addr(bss->bssid) &&
316		 (os_memcmp(bss->bssid, wpa_s->bssid, ETH_ALEN) == 0 ||
317		  os_memcmp(bss->bssid, wpa_s->pending_bssid, ETH_ALEN) == 0));
318}
319
320
321static int wpa_bss_remove_oldest_unknown(struct wpa_supplicant *wpa_s)
322{
323	struct wpa_bss *bss;
324
325	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
326		if (!wpa_bss_known(wpa_s, bss)) {
327			wpa_bss_remove(wpa_s, bss, __func__);
328			return 0;
329		}
330	}
331
332	return -1;
333}
334
335
336static int wpa_bss_remove_oldest(struct wpa_supplicant *wpa_s)
337{
338	struct wpa_bss *bss;
339
340	/*
341	 * Remove the oldest entry that does not match with any configured
342	 * network.
343	 */
344	if (wpa_bss_remove_oldest_unknown(wpa_s) == 0)
345		return 0;
346
347	/*
348	 * Remove the oldest entry that isn't currently in use.
349	 */
350	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
351		if (!wpa_bss_in_use(wpa_s, bss)) {
352			wpa_bss_remove(wpa_s, bss, __func__);
353			return 0;
354		}
355	}
356
357	return -1;
358}
359
360
361static struct wpa_bss * wpa_bss_add(struct wpa_supplicant *wpa_s,
362				    const u8 *ssid, size_t ssid_len,
363				    struct wpa_scan_res *res,
364				    struct os_reltime *fetch_time)
365{
366	struct wpa_bss *bss;
367
368	bss = os_zalloc(sizeof(*bss) + res->ie_len + res->beacon_ie_len);
369	if (bss == NULL)
370		return NULL;
371	bss->id = wpa_s->bss_next_id++;
372	bss->last_update_idx = wpa_s->bss_update_idx;
373	wpa_bss_copy_res(bss, res, fetch_time);
374	os_memcpy(bss->ssid, ssid, ssid_len);
375	bss->ssid_len = ssid_len;
376	bss->ie_len = res->ie_len;
377	bss->beacon_ie_len = res->beacon_ie_len;
378	os_memcpy(bss + 1, res + 1, res->ie_len + res->beacon_ie_len);
379	wpa_bss_set_hessid(bss);
380
381	if (wpa_s->num_bss + 1 > wpa_s->conf->bss_max_count &&
382	    wpa_bss_remove_oldest(wpa_s) != 0) {
383		wpa_printf(MSG_ERROR, "Increasing the MAX BSS count to %d "
384			   "because all BSSes are in use. We should normally "
385			   "not get here!", (int) wpa_s->num_bss + 1);
386		wpa_s->conf->bss_max_count = wpa_s->num_bss + 1;
387	}
388
389	dl_list_add_tail(&wpa_s->bss, &bss->list);
390	dl_list_add_tail(&wpa_s->bss_id, &bss->list_id);
391	wpa_s->num_bss++;
392	wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Add new id %u BSSID " MACSTR
393		" SSID '%s'",
394		bss->id, MAC2STR(bss->bssid), wpa_ssid_txt(ssid, ssid_len));
395	wpas_notify_bss_added(wpa_s, bss->bssid, bss->id);
396	return bss;
397}
398
399
400static int are_ies_equal(const struct wpa_bss *old,
401			 const struct wpa_scan_res *new_res, u32 ie)
402{
403	const u8 *old_ie, *new_ie;
404	struct wpabuf *old_ie_buff = NULL;
405	struct wpabuf *new_ie_buff = NULL;
406	int new_ie_len, old_ie_len, ret, is_multi;
407
408	switch (ie) {
409	case WPA_IE_VENDOR_TYPE:
410		old_ie = wpa_bss_get_vendor_ie(old, ie);
411		new_ie = wpa_scan_get_vendor_ie(new_res, ie);
412		is_multi = 0;
413		break;
414	case WPS_IE_VENDOR_TYPE:
415		old_ie_buff = wpa_bss_get_vendor_ie_multi(old, ie);
416		new_ie_buff = wpa_scan_get_vendor_ie_multi(new_res, ie);
417		is_multi = 1;
418		break;
419	case WLAN_EID_RSN:
420	case WLAN_EID_SUPP_RATES:
421	case WLAN_EID_EXT_SUPP_RATES:
422		old_ie = wpa_bss_get_ie(old, ie);
423		new_ie = wpa_scan_get_ie(new_res, ie);
424		is_multi = 0;
425		break;
426	default:
427		wpa_printf(MSG_DEBUG, "bss: %s: cannot compare IEs", __func__);
428		return 0;
429	}
430
431	if (is_multi) {
432		/* in case of multiple IEs stored in buffer */
433		old_ie = old_ie_buff ? wpabuf_head_u8(old_ie_buff) : NULL;
434		new_ie = new_ie_buff ? wpabuf_head_u8(new_ie_buff) : NULL;
435		old_ie_len = old_ie_buff ? wpabuf_len(old_ie_buff) : 0;
436		new_ie_len = new_ie_buff ? wpabuf_len(new_ie_buff) : 0;
437	} else {
438		/* in case of single IE */
439		old_ie_len = old_ie ? old_ie[1] + 2 : 0;
440		new_ie_len = new_ie ? new_ie[1] + 2 : 0;
441	}
442
443	if (!old_ie || !new_ie)
444		ret = !old_ie && !new_ie;
445	else
446		ret = (old_ie_len == new_ie_len &&
447		       os_memcmp(old_ie, new_ie, old_ie_len) == 0);
448
449	wpabuf_free(old_ie_buff);
450	wpabuf_free(new_ie_buff);
451
452	return ret;
453}
454
455
456static u32 wpa_bss_compare_res(const struct wpa_bss *old,
457			       const struct wpa_scan_res *new_res)
458{
459	u32 changes = 0;
460	int caps_diff = old->caps ^ new_res->caps;
461
462	if (old->freq != new_res->freq)
463		changes |= WPA_BSS_FREQ_CHANGED_FLAG;
464
465	if (old->level != new_res->level)
466		changes |= WPA_BSS_SIGNAL_CHANGED_FLAG;
467
468	if (caps_diff & IEEE80211_CAP_PRIVACY)
469		changes |= WPA_BSS_PRIVACY_CHANGED_FLAG;
470
471	if (caps_diff & IEEE80211_CAP_IBSS)
472		changes |= WPA_BSS_MODE_CHANGED_FLAG;
473
474	if (old->ie_len == new_res->ie_len &&
475	    os_memcmp(old + 1, new_res + 1, old->ie_len) == 0)
476		return changes;
477	changes |= WPA_BSS_IES_CHANGED_FLAG;
478
479	if (!are_ies_equal(old, new_res, WPA_IE_VENDOR_TYPE))
480		changes |= WPA_BSS_WPAIE_CHANGED_FLAG;
481
482	if (!are_ies_equal(old, new_res, WLAN_EID_RSN))
483		changes |= WPA_BSS_RSNIE_CHANGED_FLAG;
484
485	if (!are_ies_equal(old, new_res, WPS_IE_VENDOR_TYPE))
486		changes |= WPA_BSS_WPS_CHANGED_FLAG;
487
488	if (!are_ies_equal(old, new_res, WLAN_EID_SUPP_RATES) ||
489	    !are_ies_equal(old, new_res, WLAN_EID_EXT_SUPP_RATES))
490		changes |= WPA_BSS_RATES_CHANGED_FLAG;
491
492	return changes;
493}
494
495
496static void notify_bss_changes(struct wpa_supplicant *wpa_s, u32 changes,
497			       const struct wpa_bss *bss)
498{
499	if (changes & WPA_BSS_FREQ_CHANGED_FLAG)
500		wpas_notify_bss_freq_changed(wpa_s, bss->id);
501
502	if (changes & WPA_BSS_SIGNAL_CHANGED_FLAG)
503		wpas_notify_bss_signal_changed(wpa_s, bss->id);
504
505	if (changes & WPA_BSS_PRIVACY_CHANGED_FLAG)
506		wpas_notify_bss_privacy_changed(wpa_s, bss->id);
507
508	if (changes & WPA_BSS_MODE_CHANGED_FLAG)
509		wpas_notify_bss_mode_changed(wpa_s, bss->id);
510
511	if (changes & WPA_BSS_WPAIE_CHANGED_FLAG)
512		wpas_notify_bss_wpaie_changed(wpa_s, bss->id);
513
514	if (changes & WPA_BSS_RSNIE_CHANGED_FLAG)
515		wpas_notify_bss_rsnie_changed(wpa_s, bss->id);
516
517	if (changes & WPA_BSS_WPS_CHANGED_FLAG)
518		wpas_notify_bss_wps_changed(wpa_s, bss->id);
519
520	if (changes & WPA_BSS_IES_CHANGED_FLAG)
521		wpas_notify_bss_ies_changed(wpa_s, bss->id);
522
523	if (changes & WPA_BSS_RATES_CHANGED_FLAG)
524		wpas_notify_bss_rates_changed(wpa_s, bss->id);
525
526	wpas_notify_bss_seen(wpa_s, bss->id);
527}
528
529
530static struct wpa_bss *
531wpa_bss_update(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
532	       struct wpa_scan_res *res, struct os_reltime *fetch_time)
533{
534	u32 changes;
535
536	changes = wpa_bss_compare_res(bss, res);
537	bss->scan_miss_count = 0;
538	bss->last_update_idx = wpa_s->bss_update_idx;
539	wpa_bss_copy_res(bss, res, fetch_time);
540	/* Move the entry to the end of the list */
541	dl_list_del(&bss->list);
542#ifdef CONFIG_P2P
543	if (wpa_bss_get_vendor_ie(bss, P2P_IE_VENDOR_TYPE) &&
544	    !wpa_scan_get_vendor_ie(res, P2P_IE_VENDOR_TYPE)) {
545		/*
546		 * This can happen when non-P2P station interface runs a scan
547		 * without P2P IE in the Probe Request frame. P2P GO would reply
548		 * to that with a Probe Response that does not include P2P IE.
549		 * Do not update the IEs in this BSS entry to avoid such loss of
550		 * information that may be needed for P2P operations to
551		 * determine group information.
552		 */
553		wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Do not update scan IEs for "
554			MACSTR " since that would remove P2P IE information",
555			MAC2STR(bss->bssid));
556	} else
557#endif /* CONFIG_P2P */
558	if (bss->ie_len + bss->beacon_ie_len >=
559	    res->ie_len + res->beacon_ie_len) {
560		os_memcpy(bss + 1, res + 1, res->ie_len + res->beacon_ie_len);
561		bss->ie_len = res->ie_len;
562		bss->beacon_ie_len = res->beacon_ie_len;
563	} else {
564		struct wpa_bss *nbss;
565		struct dl_list *prev = bss->list_id.prev;
566		dl_list_del(&bss->list_id);
567		nbss = os_realloc(bss, sizeof(*bss) + res->ie_len +
568				  res->beacon_ie_len);
569		if (nbss) {
570			unsigned int i;
571			for (i = 0; i < wpa_s->last_scan_res_used; i++) {
572				if (wpa_s->last_scan_res[i] == bss) {
573					wpa_s->last_scan_res[i] = nbss;
574					break;
575				}
576			}
577			if (wpa_s->current_bss == bss)
578				wpa_s->current_bss = nbss;
579			wpa_bss_update_pending_connect(wpa_s, bss, nbss);
580			bss = nbss;
581			os_memcpy(bss + 1, res + 1,
582				  res->ie_len + res->beacon_ie_len);
583			bss->ie_len = res->ie_len;
584			bss->beacon_ie_len = res->beacon_ie_len;
585		}
586		dl_list_add(prev, &bss->list_id);
587	}
588	if (changes & WPA_BSS_IES_CHANGED_FLAG)
589		wpa_bss_set_hessid(bss);
590	dl_list_add_tail(&wpa_s->bss, &bss->list);
591
592	notify_bss_changes(wpa_s, changes, bss);
593
594	return bss;
595}
596
597
598/**
599 * wpa_bss_update_start - Start a BSS table update from scan results
600 * @wpa_s: Pointer to wpa_supplicant data
601 *
602 * This function is called at the start of each BSS table update round for new
603 * scan results. The actual scan result entries are indicated with calls to
604 * wpa_bss_update_scan_res() and the update round is finished with a call to
605 * wpa_bss_update_end().
606 */
607void wpa_bss_update_start(struct wpa_supplicant *wpa_s)
608{
609	wpa_s->bss_update_idx++;
610	wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Start scan result update %u",
611		wpa_s->bss_update_idx);
612	wpa_s->last_scan_res_used = 0;
613}
614
615
616/**
617 * wpa_bss_update_scan_res - Update a BSS table entry based on a scan result
618 * @wpa_s: Pointer to wpa_supplicant data
619 * @res: Scan result
620 * @fetch_time: Time when the result was fetched from the driver
621 *
622 * This function updates a BSS table entry (or adds one) based on a scan result.
623 * This is called separately for each scan result between the calls to
624 * wpa_bss_update_start() and wpa_bss_update_end().
625 */
626void wpa_bss_update_scan_res(struct wpa_supplicant *wpa_s,
627			     struct wpa_scan_res *res,
628			     struct os_reltime *fetch_time)
629{
630	const u8 *ssid, *p2p, *mesh;
631	struct wpa_bss *bss;
632
633	if (wpa_s->conf->ignore_old_scan_res) {
634		struct os_reltime update;
635		calculate_update_time(fetch_time, res->age, &update);
636		if (os_reltime_before(&update, &wpa_s->scan_trigger_time)) {
637			struct os_reltime age;
638			os_reltime_sub(&wpa_s->scan_trigger_time, &update,
639				       &age);
640			wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Ignore driver BSS "
641				"table entry that is %u.%06u seconds older "
642				"than our scan trigger",
643				(unsigned int) age.sec,
644				(unsigned int) age.usec);
645			return;
646		}
647	}
648
649	ssid = wpa_scan_get_ie(res, WLAN_EID_SSID);
650	if (ssid == NULL) {
651		wpa_dbg(wpa_s, MSG_DEBUG, "BSS: No SSID IE included for "
652			MACSTR, MAC2STR(res->bssid));
653		return;
654	}
655	if (ssid[1] > SSID_MAX_LEN) {
656		wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Too long SSID IE included for "
657			MACSTR, MAC2STR(res->bssid));
658		return;
659	}
660
661	p2p = wpa_scan_get_vendor_ie(res, P2P_IE_VENDOR_TYPE);
662#ifdef CONFIG_P2P
663	if (p2p == NULL &&
664	    wpa_s->p2p_group_interface != NOT_P2P_GROUP_INTERFACE) {
665		/*
666		 * If it's a P2P specific interface, then don't update
667		 * the scan result without a P2P IE.
668		 */
669		wpa_printf(MSG_DEBUG, "BSS: No P2P IE - skipping BSS " MACSTR
670			   " update for P2P interface", MAC2STR(res->bssid));
671		return;
672	}
673#endif /* CONFIG_P2P */
674	if (p2p && ssid[1] == P2P_WILDCARD_SSID_LEN &&
675	    os_memcmp(ssid + 2, P2P_WILDCARD_SSID, P2P_WILDCARD_SSID_LEN) == 0)
676		return; /* Skip P2P listen discovery results here */
677
678	/* TODO: add option for ignoring BSSes we are not interested in
679	 * (to save memory) */
680
681	mesh = wpa_scan_get_ie(res, WLAN_EID_MESH_ID);
682	if (mesh && mesh[1] <= SSID_MAX_LEN)
683		ssid = mesh;
684
685	bss = wpa_bss_get(wpa_s, res->bssid, ssid + 2, ssid[1]);
686	if (bss == NULL)
687		bss = wpa_bss_add(wpa_s, ssid + 2, ssid[1], res, fetch_time);
688	else {
689		bss = wpa_bss_update(wpa_s, bss, res, fetch_time);
690		if (wpa_s->last_scan_res) {
691			unsigned int i;
692			for (i = 0; i < wpa_s->last_scan_res_used; i++) {
693				if (bss == wpa_s->last_scan_res[i]) {
694					/* Already in the list */
695					return;
696				}
697			}
698		}
699	}
700
701	if (bss == NULL)
702		return;
703	if (wpa_s->last_scan_res_used >= wpa_s->last_scan_res_size) {
704		struct wpa_bss **n;
705		unsigned int siz;
706		if (wpa_s->last_scan_res_size == 0)
707			siz = 32;
708		else
709			siz = wpa_s->last_scan_res_size * 2;
710		n = os_realloc_array(wpa_s->last_scan_res, siz,
711				     sizeof(struct wpa_bss *));
712		if (n == NULL)
713			return;
714		wpa_s->last_scan_res = n;
715		wpa_s->last_scan_res_size = siz;
716	}
717
718	if (wpa_s->last_scan_res)
719		wpa_s->last_scan_res[wpa_s->last_scan_res_used++] = bss;
720}
721
722
723static int wpa_bss_included_in_scan(const struct wpa_bss *bss,
724				    const struct scan_info *info)
725{
726	int found;
727	size_t i;
728
729	if (info == NULL)
730		return 1;
731
732	if (info->num_freqs) {
733		found = 0;
734		for (i = 0; i < info->num_freqs; i++) {
735			if (bss->freq == info->freqs[i]) {
736				found = 1;
737				break;
738			}
739		}
740		if (!found)
741			return 0;
742	}
743
744	if (info->num_ssids) {
745		found = 0;
746		for (i = 0; i < info->num_ssids; i++) {
747			const struct wpa_driver_scan_ssid *s = &info->ssids[i];
748			if ((s->ssid == NULL || s->ssid_len == 0) ||
749			    (s->ssid_len == bss->ssid_len &&
750			     os_memcmp(s->ssid, bss->ssid, bss->ssid_len) ==
751			     0)) {
752				found = 1;
753				break;
754			}
755		}
756		if (!found)
757			return 0;
758	}
759
760	return 1;
761}
762
763
764/**
765 * wpa_bss_update_end - End a BSS table update from scan results
766 * @wpa_s: Pointer to wpa_supplicant data
767 * @info: Information about scan parameters
768 * @new_scan: Whether this update round was based on a new scan
769 *
770 * This function is called at the end of each BSS table update round for new
771 * scan results. The start of the update was indicated with a call to
772 * wpa_bss_update_start().
773 */
774void wpa_bss_update_end(struct wpa_supplicant *wpa_s, struct scan_info *info,
775			int new_scan)
776{
777	struct wpa_bss *bss, *n;
778
779	os_get_reltime(&wpa_s->last_scan);
780	if (!new_scan)
781		return; /* do not expire entries without new scan */
782
783	dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
784		if (wpa_bss_in_use(wpa_s, bss))
785			continue;
786		if (!wpa_bss_included_in_scan(bss, info))
787			continue; /* expire only BSSes that were scanned */
788		if (bss->last_update_idx < wpa_s->bss_update_idx)
789			bss->scan_miss_count++;
790		if (bss->scan_miss_count >=
791		    wpa_s->conf->bss_expiration_scan_count) {
792			wpa_bss_remove(wpa_s, bss, "no match in scan");
793		}
794	}
795
796	wpa_printf(MSG_DEBUG, "BSS: last_scan_res_used=%u/%u",
797		   wpa_s->last_scan_res_used, wpa_s->last_scan_res_size);
798}
799
800
801/**
802 * wpa_bss_flush_by_age - Flush old BSS entries
803 * @wpa_s: Pointer to wpa_supplicant data
804 * @age: Maximum entry age in seconds
805 *
806 * Remove BSS entries that have not been updated during the last @age seconds.
807 */
808void wpa_bss_flush_by_age(struct wpa_supplicant *wpa_s, int age)
809{
810	struct wpa_bss *bss, *n;
811	struct os_reltime t;
812
813	if (dl_list_empty(&wpa_s->bss))
814		return;
815
816	os_get_reltime(&t);
817	t.sec -= age;
818
819	dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
820		if (wpa_bss_in_use(wpa_s, bss))
821			continue;
822
823		if (os_reltime_before(&bss->last_update, &t)) {
824			wpa_bss_remove(wpa_s, bss, __func__);
825		} else
826			break;
827	}
828}
829
830
831static void wpa_bss_timeout(void *eloop_ctx, void *timeout_ctx)
832{
833	struct wpa_supplicant *wpa_s = eloop_ctx;
834
835	wpa_bss_flush_by_age(wpa_s, wpa_s->conf->bss_expiration_age);
836	eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0,
837			       wpa_bss_timeout, wpa_s, NULL);
838}
839
840
841/**
842 * wpa_bss_init - Initialize BSS table
843 * @wpa_s: Pointer to wpa_supplicant data
844 * Returns: 0 on success, -1 on failure
845 *
846 * This prepares BSS table lists and timer for periodic updates. The BSS table
847 * is deinitialized with wpa_bss_deinit() once not needed anymore.
848 */
849int wpa_bss_init(struct wpa_supplicant *wpa_s)
850{
851	dl_list_init(&wpa_s->bss);
852	dl_list_init(&wpa_s->bss_id);
853	eloop_register_timeout(WPA_BSS_EXPIRATION_PERIOD, 0,
854			       wpa_bss_timeout, wpa_s, NULL);
855	return 0;
856}
857
858
859/**
860 * wpa_bss_flush - Flush all unused BSS entries
861 * @wpa_s: Pointer to wpa_supplicant data
862 */
863void wpa_bss_flush(struct wpa_supplicant *wpa_s)
864{
865	struct wpa_bss *bss, *n;
866
867	wpa_s->clear_driver_scan_cache = 1;
868
869	if (wpa_s->bss.next == NULL)
870		return; /* BSS table not yet initialized */
871
872	dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
873		if (wpa_bss_in_use(wpa_s, bss))
874			continue;
875		wpa_bss_remove(wpa_s, bss, __func__);
876	}
877}
878
879
880/**
881 * wpa_bss_deinit - Deinitialize BSS table
882 * @wpa_s: Pointer to wpa_supplicant data
883 */
884void wpa_bss_deinit(struct wpa_supplicant *wpa_s)
885{
886	eloop_cancel_timeout(wpa_bss_timeout, wpa_s, NULL);
887	wpa_bss_flush(wpa_s);
888}
889
890
891/**
892 * wpa_bss_get_bssid - Fetch a BSS table entry based on BSSID
893 * @wpa_s: Pointer to wpa_supplicant data
894 * @bssid: BSSID
895 * Returns: Pointer to the BSS entry or %NULL if not found
896 */
897struct wpa_bss * wpa_bss_get_bssid(struct wpa_supplicant *wpa_s,
898				   const u8 *bssid)
899{
900	struct wpa_bss *bss;
901	if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
902		return NULL;
903	dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
904		if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0)
905			return bss;
906	}
907	return NULL;
908}
909
910
911/**
912 * wpa_bss_get_bssid_latest - Fetch the latest BSS table entry based on BSSID
913 * @wpa_s: Pointer to wpa_supplicant data
914 * @bssid: BSSID
915 * Returns: Pointer to the BSS entry or %NULL if not found
916 *
917 * This function is like wpa_bss_get_bssid(), but full BSS table is iterated to
918 * find the entry that has the most recent update. This can help in finding the
919 * correct entry in cases where the SSID of the AP may have changed recently
920 * (e.g., in WPS reconfiguration cases).
921 */
922struct wpa_bss * wpa_bss_get_bssid_latest(struct wpa_supplicant *wpa_s,
923					  const u8 *bssid)
924{
925	struct wpa_bss *bss, *found = NULL;
926	if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
927		return NULL;
928	dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
929		if (os_memcmp(bss->bssid, bssid, ETH_ALEN) != 0)
930			continue;
931		if (found == NULL ||
932		    os_reltime_before(&found->last_update, &bss->last_update))
933			found = bss;
934	}
935	return found;
936}
937
938
939#ifdef CONFIG_P2P
940/**
941 * wpa_bss_get_p2p_dev_addr - Fetch a BSS table entry based on P2P Device Addr
942 * @wpa_s: Pointer to wpa_supplicant data
943 * @dev_addr: P2P Device Address of the GO
944 * Returns: Pointer to the BSS entry or %NULL if not found
945 */
946struct wpa_bss * wpa_bss_get_p2p_dev_addr(struct wpa_supplicant *wpa_s,
947					  const u8 *dev_addr)
948{
949	struct wpa_bss *bss;
950	dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
951		u8 addr[ETH_ALEN];
952		if (p2p_parse_dev_addr((const u8 *) (bss + 1), bss->ie_len,
953				       addr) == 0 &&
954		    os_memcmp(addr, dev_addr, ETH_ALEN) == 0)
955			return bss;
956	}
957	return NULL;
958}
959#endif /* CONFIG_P2P */
960
961
962/**
963 * wpa_bss_get_id - Fetch a BSS table entry based on identifier
964 * @wpa_s: Pointer to wpa_supplicant data
965 * @id: Unique identifier (struct wpa_bss::id) assigned for the entry
966 * Returns: Pointer to the BSS entry or %NULL if not found
967 */
968struct wpa_bss * wpa_bss_get_id(struct wpa_supplicant *wpa_s, unsigned int id)
969{
970	struct wpa_bss *bss;
971	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
972		if (bss->id == id)
973			return bss;
974	}
975	return NULL;
976}
977
978
979/**
980 * wpa_bss_get_id_range - Fetch a BSS table entry based on identifier range
981 * @wpa_s: Pointer to wpa_supplicant data
982 * @idf: Smallest allowed identifier assigned for the entry
983 * @idf: Largest allowed identifier assigned for the entry
984 * Returns: Pointer to the BSS entry or %NULL if not found
985 *
986 * This function is similar to wpa_bss_get_id() but allows a BSS entry with the
987 * smallest id value to be fetched within the specified range without the
988 * caller having to know the exact id.
989 */
990struct wpa_bss * wpa_bss_get_id_range(struct wpa_supplicant *wpa_s,
991				      unsigned int idf, unsigned int idl)
992{
993	struct wpa_bss *bss;
994	dl_list_for_each(bss, &wpa_s->bss_id, struct wpa_bss, list_id) {
995		if (bss->id >= idf && bss->id <= idl)
996			return bss;
997	}
998	return NULL;
999}
1000
1001
1002/**
1003 * wpa_bss_get_ie - Fetch a specified information element from a BSS entry
1004 * @bss: BSS table entry
1005 * @ie: Information element identitifier (WLAN_EID_*)
1006 * Returns: Pointer to the information element (id field) or %NULL if not found
1007 *
1008 * This function returns the first matching information element in the BSS
1009 * entry.
1010 */
1011const u8 * wpa_bss_get_ie(const struct wpa_bss *bss, u8 ie)
1012{
1013	const u8 *end, *pos;
1014
1015	pos = (const u8 *) (bss + 1);
1016	end = pos + bss->ie_len;
1017
1018	while (pos + 1 < end) {
1019		if (pos + 2 + pos[1] > end)
1020			break;
1021		if (pos[0] == ie)
1022			return pos;
1023		pos += 2 + pos[1];
1024	}
1025
1026	return NULL;
1027}
1028
1029
1030/**
1031 * wpa_bss_get_vendor_ie - Fetch a vendor information element from a BSS entry
1032 * @bss: BSS table entry
1033 * @vendor_type: Vendor type (four octets starting the IE payload)
1034 * Returns: Pointer to the information element (id field) or %NULL if not found
1035 *
1036 * This function returns the first matching information element in the BSS
1037 * entry.
1038 */
1039const u8 * wpa_bss_get_vendor_ie(const struct wpa_bss *bss, u32 vendor_type)
1040{
1041	const u8 *end, *pos;
1042
1043	pos = (const u8 *) (bss + 1);
1044	end = pos + bss->ie_len;
1045
1046	while (pos + 1 < end) {
1047		if (pos + 2 + pos[1] > end)
1048			break;
1049		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1050		    vendor_type == WPA_GET_BE32(&pos[2]))
1051			return pos;
1052		pos += 2 + pos[1];
1053	}
1054
1055	return NULL;
1056}
1057
1058
1059/**
1060 * wpa_bss_get_vendor_ie_beacon - Fetch a vendor information from a BSS entry
1061 * @bss: BSS table entry
1062 * @vendor_type: Vendor type (four octets starting the IE payload)
1063 * Returns: Pointer to the information element (id field) or %NULL if not found
1064 *
1065 * This function returns the first matching information element in the BSS
1066 * entry.
1067 *
1068 * This function is like wpa_bss_get_vendor_ie(), but uses IE buffer only
1069 * from Beacon frames instead of either Beacon or Probe Response frames.
1070 */
1071const u8 * wpa_bss_get_vendor_ie_beacon(const struct wpa_bss *bss,
1072					u32 vendor_type)
1073{
1074	const u8 *end, *pos;
1075
1076	if (bss->beacon_ie_len == 0)
1077		return NULL;
1078
1079	pos = (const u8 *) (bss + 1);
1080	pos += bss->ie_len;
1081	end = pos + bss->beacon_ie_len;
1082
1083	while (pos + 1 < end) {
1084		if (pos + 2 + pos[1] > end)
1085			break;
1086		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1087		    vendor_type == WPA_GET_BE32(&pos[2]))
1088			return pos;
1089		pos += 2 + pos[1];
1090	}
1091
1092	return NULL;
1093}
1094
1095
1096/**
1097 * wpa_bss_get_vendor_ie_multi - Fetch vendor IE data from a BSS entry
1098 * @bss: BSS table entry
1099 * @vendor_type: Vendor type (four octets starting the IE payload)
1100 * Returns: Pointer to the information element payload or %NULL if not found
1101 *
1102 * This function returns concatenated payload of possibly fragmented vendor
1103 * specific information elements in the BSS entry. The caller is responsible for
1104 * freeing the returned buffer.
1105 */
1106struct wpabuf * wpa_bss_get_vendor_ie_multi(const struct wpa_bss *bss,
1107					    u32 vendor_type)
1108{
1109	struct wpabuf *buf;
1110	const u8 *end, *pos;
1111
1112	buf = wpabuf_alloc(bss->ie_len);
1113	if (buf == NULL)
1114		return NULL;
1115
1116	pos = (const u8 *) (bss + 1);
1117	end = pos + bss->ie_len;
1118
1119	while (pos + 1 < end) {
1120		if (pos + 2 + pos[1] > end)
1121			break;
1122		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1123		    vendor_type == WPA_GET_BE32(&pos[2]))
1124			wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1125		pos += 2 + pos[1];
1126	}
1127
1128	if (wpabuf_len(buf) == 0) {
1129		wpabuf_free(buf);
1130		buf = NULL;
1131	}
1132
1133	return buf;
1134}
1135
1136
1137/**
1138 * wpa_bss_get_vendor_ie_multi_beacon - Fetch vendor IE data from a BSS entry
1139 * @bss: BSS table entry
1140 * @vendor_type: Vendor type (four octets starting the IE payload)
1141 * Returns: Pointer to the information element payload or %NULL if not found
1142 *
1143 * This function returns concatenated payload of possibly fragmented vendor
1144 * specific information elements in the BSS entry. The caller is responsible for
1145 * freeing the returned buffer.
1146 *
1147 * This function is like wpa_bss_get_vendor_ie_multi(), but uses IE buffer only
1148 * from Beacon frames instead of either Beacon or Probe Response frames.
1149 */
1150struct wpabuf * wpa_bss_get_vendor_ie_multi_beacon(const struct wpa_bss *bss,
1151						   u32 vendor_type)
1152{
1153	struct wpabuf *buf;
1154	const u8 *end, *pos;
1155
1156	buf = wpabuf_alloc(bss->beacon_ie_len);
1157	if (buf == NULL)
1158		return NULL;
1159
1160	pos = (const u8 *) (bss + 1);
1161	pos += bss->ie_len;
1162	end = pos + bss->beacon_ie_len;
1163
1164	while (pos + 1 < end) {
1165		if (pos + 2 + pos[1] > end)
1166			break;
1167		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1168		    vendor_type == WPA_GET_BE32(&pos[2]))
1169			wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1170		pos += 2 + pos[1];
1171	}
1172
1173	if (wpabuf_len(buf) == 0) {
1174		wpabuf_free(buf);
1175		buf = NULL;
1176	}
1177
1178	return buf;
1179}
1180
1181
1182/**
1183 * wpa_bss_get_max_rate - Get maximum legacy TX rate supported in a BSS
1184 * @bss: BSS table entry
1185 * Returns: Maximum legacy rate in units of 500 kbps
1186 */
1187int wpa_bss_get_max_rate(const struct wpa_bss *bss)
1188{
1189	int rate = 0;
1190	const u8 *ie;
1191	int i;
1192
1193	ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES);
1194	for (i = 0; ie && i < ie[1]; i++) {
1195		if ((ie[i + 2] & 0x7f) > rate)
1196			rate = ie[i + 2] & 0x7f;
1197	}
1198
1199	ie = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES);
1200	for (i = 0; ie && i < ie[1]; i++) {
1201		if ((ie[i + 2] & 0x7f) > rate)
1202			rate = ie[i + 2] & 0x7f;
1203	}
1204
1205	return rate;
1206}
1207
1208
1209/**
1210 * wpa_bss_get_bit_rates - Get legacy TX rates supported in a BSS
1211 * @bss: BSS table entry
1212 * @rates: Buffer for returning a pointer to the rates list (units of 500 kbps)
1213 * Returns: number of legacy TX rates or -1 on failure
1214 *
1215 * The caller is responsible for freeing the returned buffer with os_free() in
1216 * case of success.
1217 */
1218int wpa_bss_get_bit_rates(const struct wpa_bss *bss, u8 **rates)
1219{
1220	const u8 *ie, *ie2;
1221	int i, j;
1222	unsigned int len;
1223	u8 *r;
1224
1225	ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES);
1226	ie2 = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES);
1227
1228	len = (ie ? ie[1] : 0) + (ie2 ? ie2[1] : 0);
1229
1230	r = os_malloc(len);
1231	if (!r)
1232		return -1;
1233
1234	for (i = 0; ie && i < ie[1]; i++)
1235		r[i] = ie[i + 2] & 0x7f;
1236
1237	for (j = 0; ie2 && j < ie2[1]; j++)
1238		r[i + j] = ie2[j + 2] & 0x7f;
1239
1240	*rates = r;
1241	return len;
1242}
1243