1 /*
2  * BSS table
3  * Copyright (c) 2009-2019, 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 "eap_peer/eap.h"
16 #include "wpa_supplicant_i.h"
17 #include "config.h"
18 #include "notify.h"
19 #include "scan.h"
20 #include "bss.h"
21 
wpa_bss_set_hessid(struct wpa_bss * bss)22 static void wpa_bss_set_hessid(struct wpa_bss *bss)
23 {
24 #ifdef CONFIG_INTERWORKING
25 	const u8 *ie = wpa_bss_get_ie(bss, WLAN_EID_INTERWORKING);
26 	if (ie == NULL || (ie[1] != 7 && ie[1] != 9)) {
27 		os_memset(bss->hessid, 0, ETH_ALEN);
28 		return;
29 	}
30 	if (ie[1] == 7)
31 		os_memcpy(bss->hessid, ie + 3, ETH_ALEN);
32 	else
33 		os_memcpy(bss->hessid, ie + 5, ETH_ALEN);
34 #endif /* CONFIG_INTERWORKING */
35 }
36 
37 
38 /**
39  * wpa_bss_anqp_alloc - Allocate ANQP data structure for a BSS entry
40  * Returns: Allocated ANQP data structure or %NULL on failure
41  *
42  * The allocated ANQP data structure has its users count set to 1. It may be
43  * shared by multiple BSS entries and each shared entry is freed with
44  * wpa_bss_anqp_free().
45  */
wpa_bss_anqp_alloc(void)46 struct wpa_bss_anqp * wpa_bss_anqp_alloc(void)
47 {
48 	struct wpa_bss_anqp *anqp;
49 	anqp = os_zalloc(sizeof(*anqp));
50 	if (anqp == NULL)
51 		return NULL;
52 #ifdef CONFIG_INTERWORKING
53 	dl_list_init(&anqp->anqp_elems);
54 #endif /* CONFIG_INTERWORKING */
55 	anqp->users = 1;
56 	return anqp;
57 }
58 
59 
60 /**
61  * wpa_bss_anqp_clone - Clone an ANQP data structure
62  * @anqp: ANQP data structure from wpa_bss_anqp_alloc()
63  * Returns: Cloned ANQP data structure or %NULL on failure
64  */
wpa_bss_anqp_clone(struct wpa_bss_anqp * anqp)65 static struct wpa_bss_anqp * wpa_bss_anqp_clone(struct wpa_bss_anqp *anqp)
66 {
67 	struct wpa_bss_anqp *n;
68 
69 	n = os_zalloc(sizeof(*n));
70 	if (n == NULL)
71 		return NULL;
72 
73 #define ANQP_DUP(f) if (anqp->f) n->f = wpabuf_dup(anqp->f)
74 #ifdef CONFIG_INTERWORKING
75 	dl_list_init(&n->anqp_elems);
76 	ANQP_DUP(capability_list);
77 	ANQP_DUP(venue_name);
78 	ANQP_DUP(network_auth_type);
79 	ANQP_DUP(roaming_consortium);
80 	ANQP_DUP(ip_addr_type_availability);
81 	ANQP_DUP(nai_realm);
82 	ANQP_DUP(anqp_3gpp);
83 	ANQP_DUP(domain_name);
84 	ANQP_DUP(fils_realm_info);
85 #endif /* CONFIG_INTERWORKING */
86 #ifdef CONFIG_HS20
87 	ANQP_DUP(hs20_capability_list);
88 	ANQP_DUP(hs20_operator_friendly_name);
89 	ANQP_DUP(hs20_wan_metrics);
90 	ANQP_DUP(hs20_connection_capability);
91 	ANQP_DUP(hs20_operating_class);
92 	ANQP_DUP(hs20_osu_providers_list);
93 	ANQP_DUP(hs20_operator_icon_metadata);
94 	ANQP_DUP(hs20_osu_providers_nai_list);
95 #endif /* CONFIG_HS20 */
96 #undef ANQP_DUP
97 
98 	return n;
99 }
100 
101 
102 /**
103  * wpa_bss_anqp_unshare_alloc - Unshare ANQP data (if shared) in a BSS entry
104  * @bss: BSS entry
105  * Returns: 0 on success, -1 on failure
106  *
107  * This function ensures the specific BSS entry has an ANQP data structure that
108  * is not shared with any other BSS entry.
109  */
wpa_bss_anqp_unshare_alloc(struct wpa_bss * bss)110 int wpa_bss_anqp_unshare_alloc(struct wpa_bss *bss)
111 {
112 	struct wpa_bss_anqp *anqp;
113 
114 	if (bss->anqp && bss->anqp->users > 1) {
115 		/* allocated, but shared - clone an unshared copy */
116 		anqp = wpa_bss_anqp_clone(bss->anqp);
117 		if (anqp == NULL)
118 			return -1;
119 		anqp->users = 1;
120 		bss->anqp->users--;
121 		bss->anqp = anqp;
122 		return 0;
123 	}
124 
125 	if (bss->anqp)
126 		return 0; /* already allocated and not shared */
127 
128 	/* not allocated - allocate a new storage area */
129 	bss->anqp = wpa_bss_anqp_alloc();
130 	return bss->anqp ? 0 : -1;
131 }
132 
133 
134 /**
135  * wpa_bss_anqp_free - Free an ANQP data structure
136  * @anqp: ANQP data structure from wpa_bss_anqp_alloc() or wpa_bss_anqp_clone()
137  */
wpa_bss_anqp_free(struct wpa_bss_anqp * anqp)138 static void wpa_bss_anqp_free(struct wpa_bss_anqp *anqp)
139 {
140 #ifdef CONFIG_INTERWORKING
141 	struct wpa_bss_anqp_elem *elem;
142 #endif /* CONFIG_INTERWORKING */
143 
144 	if (anqp == NULL)
145 		return;
146 
147 	anqp->users--;
148 	if (anqp->users > 0) {
149 		/* Another BSS entry holds a pointer to this ANQP info */
150 		return;
151 	}
152 
153 #ifdef CONFIG_INTERWORKING
154 	wpabuf_free(anqp->capability_list);
155 	wpabuf_free(anqp->venue_name);
156 	wpabuf_free(anqp->network_auth_type);
157 	wpabuf_free(anqp->roaming_consortium);
158 	wpabuf_free(anqp->ip_addr_type_availability);
159 	wpabuf_free(anqp->nai_realm);
160 	wpabuf_free(anqp->anqp_3gpp);
161 	wpabuf_free(anqp->domain_name);
162 	wpabuf_free(anqp->fils_realm_info);
163 
164 	while ((elem = dl_list_first(&anqp->anqp_elems,
165 				     struct wpa_bss_anqp_elem, list))) {
166 		dl_list_del(&elem->list);
167 		wpabuf_free(elem->payload);
168 		os_free(elem);
169 	}
170 #endif /* CONFIG_INTERWORKING */
171 #ifdef CONFIG_HS20
172 	wpabuf_free(anqp->hs20_capability_list);
173 	wpabuf_free(anqp->hs20_operator_friendly_name);
174 	wpabuf_free(anqp->hs20_wan_metrics);
175 	wpabuf_free(anqp->hs20_connection_capability);
176 	wpabuf_free(anqp->hs20_operating_class);
177 	wpabuf_free(anqp->hs20_osu_providers_list);
178 	wpabuf_free(anqp->hs20_operator_icon_metadata);
179 	wpabuf_free(anqp->hs20_osu_providers_nai_list);
180 #endif /* CONFIG_HS20 */
181 
182 	os_free(anqp);
183 }
184 
wpa_bss_check_pending_connect(struct wpa_supplicant * wpa_s,struct wpa_bss * bss)185 static bool wpa_bss_check_pending_connect(struct wpa_supplicant *wpa_s,
186 					   struct wpa_bss *bss)
187 {
188 	struct wpa_radio_work *work;
189 	struct wpa_connect_work *cwork;
190 
191 	work = radio_work_pending(wpa_s, "sme-connect");
192 	if (!work)
193 		work = radio_work_pending(wpa_s, "connect");
194 	if (!work)
195 		return false;
196 
197 	cwork = work->ctx;
198 	if (cwork->bss != bss)
199 		return false;
200 
201 	return true;
202 }
203 
wpa_bss_update_pending_connect(struct wpa_supplicant * wpa_s,struct wpa_bss * new_bss)204 static void wpa_bss_update_pending_connect(struct wpa_supplicant *wpa_s,
205 					   struct wpa_bss *new_bss)
206 {
207 	struct wpa_radio_work *work;
208 	struct wpa_connect_work *cwork;
209 
210 	work = radio_work_pending(wpa_s, "sme-connect");
211 	if (!work)
212 		work = radio_work_pending(wpa_s, "connect");
213 	if (!work)
214 		return;
215 
216 	cwork = work->ctx;
217 
218 	wpa_printf(MSG_DEBUG,
219 		   "Update BSS pointer for the pending connect radio work");
220 	cwork->bss = new_bss;
221 	if (!new_bss)
222 		cwork->bss_removed = 1;
223 }
224 
225 
wpa_bss_remove(struct wpa_supplicant * wpa_s,struct wpa_bss * bss,const char * reason)226 void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
227 		    const char *reason)
228 {
229 	if (wpa_s->last_scan_res) {
230 		unsigned int i;
231 		for (i = 0; i < wpa_s->last_scan_res_used; i++) {
232 			if (wpa_s->last_scan_res[i] == bss) {
233 				os_memmove(&wpa_s->last_scan_res[i],
234 					   &wpa_s->last_scan_res[i + 1],
235 					   (wpa_s->last_scan_res_used - i - 1)
236 					   * sizeof(struct wpa_bss *));
237 				wpa_s->last_scan_res_used--;
238 				break;
239 			}
240 		}
241 	}
242 	if (wpa_bss_check_pending_connect(wpa_s, bss))
243 		wpa_bss_update_pending_connect(wpa_s, NULL);
244 	dl_list_del(&bss->list);
245 	dl_list_del(&bss->list_id);
246 	wpa_s->num_bss--;
247 	wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Remove id %u BSSID " MACSTR
248 		" SSID '%s' due to %s", bss->id, MAC2STR(bss->bssid),
249 		wpa_ssid_txt(bss->ssid, bss->ssid_len), reason);
250 	wpas_notify_bss_removed(wpa_s, bss->bssid, bss->id);
251 	wpa_bss_anqp_free(bss->anqp);
252 	os_free(bss);
253 }
254 
255 
256 /**
257  * wpa_bss_get - Fetch a BSS table entry based on BSSID and SSID
258  * @wpa_s: Pointer to wpa_supplicant data
259  * @bssid: BSSID
260  * @ssid: SSID
261  * @ssid_len: Length of @ssid
262  * Returns: Pointer to the BSS entry or %NULL if not found
263  */
wpa_bss_get(struct wpa_supplicant * wpa_s,const u8 * bssid,const u8 * ssid,size_t ssid_len)264 struct wpa_bss * wpa_bss_get(struct wpa_supplicant *wpa_s, const u8 *bssid,
265 			     const u8 *ssid, size_t ssid_len)
266 {
267 	struct wpa_bss *bss;
268 	if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
269 		return NULL;
270 	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
271 		if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0 &&
272 		    bss->ssid_len == ssid_len &&
273 		    os_memcmp(bss->ssid, ssid, ssid_len) == 0)
274 			return bss;
275 	}
276 	return NULL;
277 }
278 
279 
calculate_update_time(const struct os_reltime * fetch_time,unsigned int age_ms,struct os_reltime * update_time)280 void calculate_update_time(const struct os_reltime *fetch_time,
281 			   unsigned int age_ms,
282 			   struct os_reltime *update_time)
283 {
284 	os_time_t usec;
285 
286 	update_time->sec = fetch_time->sec;
287 	update_time->usec = fetch_time->usec;
288 	update_time->sec -= age_ms / 1000;
289 	usec = (age_ms % 1000) * 1000;
290 	if (update_time->usec < usec) {
291 		update_time->sec--;
292 		update_time->usec += 1000000;
293 	}
294 	update_time->usec -= usec;
295 }
296 
297 
wpa_bss_copy_res(struct wpa_bss * dst,struct wpa_scan_res * src,struct os_reltime * fetch_time)298 static void wpa_bss_copy_res(struct wpa_bss *dst, struct wpa_scan_res *src,
299 			     struct os_reltime *fetch_time)
300 {
301 	dst->flags = src->flags;
302 	os_memcpy(dst->bssid, src->bssid, ETH_ALEN);
303 	dst->freq = src->freq;
304 	dst->beacon_int = src->beacon_int;
305 	dst->caps = src->caps;
306 	dst->qual = src->qual;
307 	dst->noise = src->noise;
308 	dst->level = src->level;
309 	dst->tsf = src->tsf;
310 	dst->est_throughput = src->est_throughput;
311 	dst->snr = src->snr;
312 
313 	calculate_update_time(fetch_time, src->age, &dst->last_update);
314 }
315 
316 
wpa_bss_is_wps_candidate(struct wpa_supplicant * wpa_s,struct wpa_bss * bss)317 static int wpa_bss_is_wps_candidate(struct wpa_supplicant *wpa_s,
318 				    struct wpa_bss *bss)
319 {
320 #ifdef CONFIG_WPS
321 	struct wpa_ssid *ssid;
322 	struct wpabuf *wps_ie;
323 	int pbc = 0, ret;
324 
325 	wps_ie = wpa_bss_get_vendor_ie_multi(bss, WPS_IE_VENDOR_TYPE);
326 	if (!wps_ie)
327 		return 0;
328 
329 	if (wps_is_selected_pbc_registrar(wps_ie)) {
330 		pbc = 1;
331 	} else if (!wps_is_addr_authorized(wps_ie, wpa_s->own_addr, 1)) {
332 		wpabuf_free(wps_ie);
333 		return 0;
334 	}
335 
336 	for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
337 		if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
338 			continue;
339 		if (ssid->ssid_len &&
340 		    (ssid->ssid_len != bss->ssid_len ||
341 		     os_memcmp(ssid->ssid, bss->ssid, ssid->ssid_len) != 0))
342 			continue;
343 
344 		if (pbc)
345 			ret = eap_is_wps_pbc_enrollee(&ssid->eap);
346 		else
347 			ret = eap_is_wps_pin_enrollee(&ssid->eap);
348 		wpabuf_free(wps_ie);
349 		return ret;
350 	}
351 	wpabuf_free(wps_ie);
352 #endif /* CONFIG_WPS */
353 
354 	return 0;
355 }
356 
357 
is_p2p_pending_bss(struct wpa_supplicant * wpa_s,struct wpa_bss * bss)358 static bool is_p2p_pending_bss(struct wpa_supplicant *wpa_s,
359 			       struct wpa_bss *bss)
360 {
361 #ifdef CONFIG_P2P
362 	u8 addr[ETH_ALEN];
363 
364 	if (os_memcmp(bss->bssid, wpa_s->pending_join_iface_addr,
365 		      ETH_ALEN) == 0)
366 		return true;
367 	if (!is_zero_ether_addr(wpa_s->pending_join_dev_addr) &&
368 	    p2p_parse_dev_addr(wpa_bss_ie_ptr(bss), bss->ie_len, addr) == 0 &&
369 	    os_memcmp(addr, wpa_s->pending_join_dev_addr, ETH_ALEN) == 0)
370 		return true;
371 #endif /* CONFIG_P2P */
372 	return false;
373 }
374 
375 
wpa_bss_known(struct wpa_supplicant * wpa_s,struct wpa_bss * bss)376 static int wpa_bss_known(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
377 {
378 	struct wpa_ssid *ssid;
379 
380 	if (is_p2p_pending_bss(wpa_s, bss))
381 		return 1;
382 
383 	for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
384 		if (ssid->ssid == NULL || ssid->ssid_len == 0)
385 			continue;
386 		if (ssid->ssid_len == bss->ssid_len &&
387 		    os_memcmp(ssid->ssid, bss->ssid, ssid->ssid_len) == 0)
388 			return 1;
389 	}
390 
391 	return 0;
392 }
393 
394 
wpa_bss_in_use(struct wpa_supplicant * wpa_s,struct wpa_bss * bss)395 static int wpa_bss_in_use(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
396 {
397 	if (bss == wpa_s->current_bss)
398 		return 1;
399 
400 	if (wpa_s->current_bss &&
401 	    (bss->ssid_len != wpa_s->current_bss->ssid_len ||
402 	     os_memcmp(bss->ssid, wpa_s->current_bss->ssid,
403 		       bss->ssid_len) != 0))
404 		return 0; /* SSID has changed */
405 
406 	return !is_zero_ether_addr(bss->bssid) &&
407 		(os_memcmp(bss->bssid, wpa_s->bssid, ETH_ALEN) == 0 ||
408 		 os_memcmp(bss->bssid, wpa_s->pending_bssid, ETH_ALEN) == 0);
409 }
410 
411 
wpa_bss_remove_oldest_unknown(struct wpa_supplicant * wpa_s)412 static int wpa_bss_remove_oldest_unknown(struct wpa_supplicant *wpa_s)
413 {
414 	struct wpa_bss *bss;
415 
416 	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
417 		if (!wpa_bss_known(wpa_s, bss) &&
418 		    !wpa_bss_is_wps_candidate(wpa_s, bss)) {
419 			wpa_bss_remove(wpa_s, bss, __func__);
420 			return 0;
421 		}
422 	}
423 
424 	return -1;
425 }
426 
427 
wpa_bss_remove_oldest(struct wpa_supplicant * wpa_s)428 static int wpa_bss_remove_oldest(struct wpa_supplicant *wpa_s)
429 {
430 	struct wpa_bss *bss;
431 
432 	/*
433 	 * Remove the oldest entry that does not match with any configured
434 	 * network.
435 	 */
436 	if (wpa_bss_remove_oldest_unknown(wpa_s) == 0)
437 		return 0;
438 
439 	/*
440 	 * Remove the oldest entry that isn't currently in use.
441 	 */
442 	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
443 		if (!wpa_bss_in_use(wpa_s, bss)) {
444 			wpa_bss_remove(wpa_s, bss, __func__);
445 			return 0;
446 		}
447 	}
448 
449 	return -1;
450 }
451 
452 
wpa_bss_add(struct wpa_supplicant * wpa_s,const u8 * ssid,size_t ssid_len,struct wpa_scan_res * res,struct os_reltime * fetch_time)453 static struct wpa_bss * wpa_bss_add(struct wpa_supplicant *wpa_s,
454 				    const u8 *ssid, size_t ssid_len,
455 				    struct wpa_scan_res *res,
456 				    struct os_reltime *fetch_time)
457 {
458 	struct wpa_bss *bss;
459 	char extra[50];
460 
461 	bss = os_zalloc(sizeof(*bss) + res->ie_len + res->beacon_ie_len);
462 	if (bss == NULL)
463 		return NULL;
464 	bss->id = wpa_s->bss_next_id++;
465 	bss->last_update_idx = wpa_s->bss_update_idx;
466 	wpa_bss_copy_res(bss, res, fetch_time);
467 	os_memcpy(bss->ssid, ssid, ssid_len);
468 	bss->ssid_len = ssid_len;
469 	bss->ie_len = res->ie_len;
470 	bss->beacon_ie_len = res->beacon_ie_len;
471 	os_memcpy(bss->ies, res + 1, res->ie_len + res->beacon_ie_len);
472 	wpa_bss_set_hessid(bss);
473 
474 	if (wpa_s->num_bss + 1 > wpa_s->conf->bss_max_count &&
475 	    wpa_bss_remove_oldest(wpa_s) != 0) {
476 		wpa_printf(MSG_ERROR, "Increasing the MAX BSS count to %d "
477 			   "because all BSSes are in use. We should normally "
478 			   "not get here!", (int) wpa_s->num_bss + 1);
479 		wpa_s->conf->bss_max_count = wpa_s->num_bss + 1;
480 	}
481 
482 	dl_list_add_tail(&wpa_s->bss, &bss->list);
483 	dl_list_add_tail(&wpa_s->bss_id, &bss->list_id);
484 	wpa_s->num_bss++;
485 	if (!is_zero_ether_addr(bss->hessid))
486 		os_snprintf(extra, sizeof(extra), " HESSID " MACSTR,
487 			    MAC2STR(bss->hessid));
488 	else
489 		extra[0] = '\0';
490 	wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Add new id %u BSSID " MACSTR
491 		" SSID '%s' freq %d%s",
492 		bss->id, MAC2STR(bss->bssid), wpa_ssid_txt(ssid, ssid_len),
493 		bss->freq, extra);
494 	wpas_notify_bss_added(wpa_s, bss->bssid, bss->id);
495 	return bss;
496 }
497 
498 
are_ies_equal(const struct wpa_bss * old,const struct wpa_scan_res * new_res,u32 ie)499 static int are_ies_equal(const struct wpa_bss *old,
500 			 const struct wpa_scan_res *new_res, u32 ie)
501 {
502 	const u8 *old_ie, *new_ie;
503 	struct wpabuf *old_ie_buff = NULL;
504 	struct wpabuf *new_ie_buff = NULL;
505 	int new_ie_len, old_ie_len, ret, is_multi;
506 
507 	switch (ie) {
508 	case WPA_IE_VENDOR_TYPE:
509 		old_ie = wpa_bss_get_vendor_ie(old, ie);
510 		new_ie = wpa_scan_get_vendor_ie(new_res, ie);
511 		is_multi = 0;
512 		break;
513 	case WPS_IE_VENDOR_TYPE:
514 		old_ie_buff = wpa_bss_get_vendor_ie_multi(old, ie);
515 		new_ie_buff = wpa_scan_get_vendor_ie_multi(new_res, ie);
516 		is_multi = 1;
517 		break;
518 	case WLAN_EID_RSN:
519 	case WLAN_EID_SUPP_RATES:
520 	case WLAN_EID_EXT_SUPP_RATES:
521 		old_ie = wpa_bss_get_ie(old, ie);
522 		new_ie = wpa_scan_get_ie(new_res, ie);
523 		is_multi = 0;
524 		break;
525 	default:
526 		wpa_printf(MSG_DEBUG, "bss: %s: cannot compare IEs", __func__);
527 		return 0;
528 	}
529 
530 	if (is_multi) {
531 		/* in case of multiple IEs stored in buffer */
532 		old_ie = old_ie_buff ? wpabuf_head_u8(old_ie_buff) : NULL;
533 		new_ie = new_ie_buff ? wpabuf_head_u8(new_ie_buff) : NULL;
534 		old_ie_len = old_ie_buff ? wpabuf_len(old_ie_buff) : 0;
535 		new_ie_len = new_ie_buff ? wpabuf_len(new_ie_buff) : 0;
536 	} else {
537 		/* in case of single IE */
538 		old_ie_len = old_ie ? old_ie[1] + 2 : 0;
539 		new_ie_len = new_ie ? new_ie[1] + 2 : 0;
540 	}
541 
542 	if (!old_ie || !new_ie)
543 		ret = !old_ie && !new_ie;
544 	else
545 		ret = (old_ie_len == new_ie_len &&
546 		       os_memcmp(old_ie, new_ie, old_ie_len) == 0);
547 
548 	wpabuf_free(old_ie_buff);
549 	wpabuf_free(new_ie_buff);
550 
551 	return ret;
552 }
553 
554 
wpa_bss_compare_res(const struct wpa_bss * old,const struct wpa_scan_res * new_res)555 static u32 wpa_bss_compare_res(const struct wpa_bss *old,
556 			       const struct wpa_scan_res *new_res)
557 {
558 	u32 changes = 0;
559 	int caps_diff = old->caps ^ new_res->caps;
560 
561 	if (old->freq != new_res->freq)
562 		changes |= WPA_BSS_FREQ_CHANGED_FLAG;
563 
564 	if (old->level != new_res->level)
565 		changes |= WPA_BSS_SIGNAL_CHANGED_FLAG;
566 
567 	if (caps_diff & IEEE80211_CAP_PRIVACY)
568 		changes |= WPA_BSS_PRIVACY_CHANGED_FLAG;
569 
570 	if (caps_diff & IEEE80211_CAP_IBSS)
571 		changes |= WPA_BSS_MODE_CHANGED_FLAG;
572 
573 	if (old->ie_len == new_res->ie_len &&
574 	    os_memcmp(wpa_bss_ie_ptr(old), new_res + 1, old->ie_len) == 0)
575 		return changes;
576 	changes |= WPA_BSS_IES_CHANGED_FLAG;
577 
578 	if (!are_ies_equal(old, new_res, WPA_IE_VENDOR_TYPE))
579 		changes |= WPA_BSS_WPAIE_CHANGED_FLAG;
580 
581 	if (!are_ies_equal(old, new_res, WLAN_EID_RSN))
582 		changes |= WPA_BSS_RSNIE_CHANGED_FLAG;
583 
584 	if (!are_ies_equal(old, new_res, WPS_IE_VENDOR_TYPE))
585 		changes |= WPA_BSS_WPS_CHANGED_FLAG;
586 
587 	if (!are_ies_equal(old, new_res, WLAN_EID_SUPP_RATES) ||
588 	    !are_ies_equal(old, new_res, WLAN_EID_EXT_SUPP_RATES))
589 		changes |= WPA_BSS_RATES_CHANGED_FLAG;
590 
591 	return changes;
592 }
593 
594 
notify_bss_changes(struct wpa_supplicant * wpa_s,u32 changes,const struct wpa_bss * bss)595 void notify_bss_changes(struct wpa_supplicant *wpa_s, u32 changes,
596 			const struct wpa_bss *bss)
597 {
598 	if (changes & WPA_BSS_FREQ_CHANGED_FLAG)
599 		wpas_notify_bss_freq_changed(wpa_s, bss->id);
600 
601 	if (changes & WPA_BSS_SIGNAL_CHANGED_FLAG)
602 		wpas_notify_bss_signal_changed(wpa_s, bss->id);
603 
604 	if (changes & WPA_BSS_PRIVACY_CHANGED_FLAG)
605 		wpas_notify_bss_privacy_changed(wpa_s, bss->id);
606 
607 	if (changes & WPA_BSS_MODE_CHANGED_FLAG)
608 		wpas_notify_bss_mode_changed(wpa_s, bss->id);
609 
610 	if (changes & WPA_BSS_WPAIE_CHANGED_FLAG)
611 		wpas_notify_bss_wpaie_changed(wpa_s, bss->id);
612 
613 	if (changes & WPA_BSS_RSNIE_CHANGED_FLAG)
614 		wpas_notify_bss_rsnie_changed(wpa_s, bss->id);
615 
616 	if (changes & WPA_BSS_WPS_CHANGED_FLAG)
617 		wpas_notify_bss_wps_changed(wpa_s, bss->id);
618 
619 	if (changes & WPA_BSS_IES_CHANGED_FLAG)
620 		wpas_notify_bss_ies_changed(wpa_s, bss->id);
621 
622 	if (changes & WPA_BSS_RATES_CHANGED_FLAG)
623 		wpas_notify_bss_rates_changed(wpa_s, bss->id);
624 
625 	wpas_notify_bss_seen(wpa_s, bss->id);
626 }
627 
628 
629 static struct wpa_bss *
wpa_bss_update(struct wpa_supplicant * wpa_s,struct wpa_bss * bss,struct wpa_scan_res * res,struct os_reltime * fetch_time)630 wpa_bss_update(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
631 	       struct wpa_scan_res *res, struct os_reltime *fetch_time)
632 {
633 	u32 changes;
634 
635 	if (bss->last_update_idx == wpa_s->bss_update_idx) {
636 		struct os_reltime update_time;
637 
638 		/*
639 		 * Some drivers (e.g., cfg80211) include multiple BSS entries
640 		 * for the same BSS if that BSS's channel changes. The BSS list
641 		 * implementation in wpa_supplicant does not do that and we need
642 		 * to filter out the obsolete results here to make sure only the
643 		 * most current BSS information remains in the table.
644 		 */
645 		wpa_printf(MSG_DEBUG, "BSS: " MACSTR
646 			   " has multiple entries in the scan results - select the most current one",
647 			   MAC2STR(bss->bssid));
648 		calculate_update_time(fetch_time, res->age, &update_time);
649 		wpa_printf(MSG_DEBUG,
650 			   "Previous last_update: %u.%06u (freq %d%s)",
651 			   (unsigned int) bss->last_update.sec,
652 			   (unsigned int) bss->last_update.usec,
653 			   bss->freq,
654 			   (bss->flags & WPA_BSS_ASSOCIATED) ? " assoc" : "");
655 		wpa_printf(MSG_DEBUG, "New last_update: %u.%06u (freq %d%s)",
656 			   (unsigned int) update_time.sec,
657 			   (unsigned int) update_time.usec,
658 			   res->freq,
659 			   (res->flags & WPA_SCAN_ASSOCIATED) ? " assoc" : "");
660 		if ((bss->flags & WPA_BSS_ASSOCIATED) ||
661 		    (!(res->flags & WPA_SCAN_ASSOCIATED) &&
662 		     !os_reltime_before(&bss->last_update, &update_time))) {
663 			wpa_printf(MSG_DEBUG,
664 				   "Ignore this BSS entry since the previous update looks more current");
665 			return bss;
666 		}
667 		wpa_printf(MSG_DEBUG,
668 			   "Accept this BSS entry since it looks more current than the previous update");
669 	}
670 
671 	changes = wpa_bss_compare_res(bss, res);
672 	if (changes & WPA_BSS_FREQ_CHANGED_FLAG)
673 		wpa_printf(MSG_DEBUG, "BSS: " MACSTR " changed freq %d --> %d",
674 			   MAC2STR(bss->bssid), bss->freq, res->freq);
675 	bss->scan_miss_count = 0;
676 	bss->last_update_idx = wpa_s->bss_update_idx;
677 	wpa_bss_copy_res(bss, res, fetch_time);
678 	/* Move the entry to the end of the list */
679 	dl_list_del(&bss->list);
680 #ifdef CONFIG_P2P
681 	if (wpa_bss_get_vendor_ie(bss, P2P_IE_VENDOR_TYPE) &&
682 	    !wpa_scan_get_vendor_ie(res, P2P_IE_VENDOR_TYPE)) {
683 		/*
684 		 * This can happen when non-P2P station interface runs a scan
685 		 * without P2P IE in the Probe Request frame. P2P GO would reply
686 		 * to that with a Probe Response that does not include P2P IE.
687 		 * Do not update the IEs in this BSS entry to avoid such loss of
688 		 * information that may be needed for P2P operations to
689 		 * determine group information.
690 		 */
691 		wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Do not update scan IEs for "
692 			MACSTR " since that would remove P2P IE information",
693 			MAC2STR(bss->bssid));
694 	} else
695 #endif /* CONFIG_P2P */
696 	if (bss->ie_len + bss->beacon_ie_len >=
697 	    res->ie_len + res->beacon_ie_len) {
698 		os_memcpy(bss->ies, res + 1, res->ie_len + res->beacon_ie_len);
699 		bss->ie_len = res->ie_len;
700 		bss->beacon_ie_len = res->beacon_ie_len;
701 	} else {
702 		struct wpa_bss *nbss;
703 		struct dl_list *prev = bss->list_id.prev;
704 		bool update_pending_connect = wpa_bss_check_pending_connect(
705 			wpa_s, bss);
706 		unsigned int i;
707 		bool update_current_bss = wpa_s->current_bss == bss;
708 		for (i = 0; i < wpa_s->last_scan_res_used; i++) {
709 			if (wpa_s->last_scan_res[i] == bss)
710 				break;
711 		}
712 		dl_list_del(&bss->list_id);
713 		nbss = os_realloc(bss, sizeof(*bss) + res->ie_len +
714 				  res->beacon_ie_len);
715 		if (nbss) {
716 			if (i != wpa_s->last_scan_res_used)
717 				wpa_s->last_scan_res[i] = nbss;
718 			if (update_current_bss)
719 				wpa_s->current_bss = nbss;
720 			if (update_pending_connect)
721 				wpa_bss_update_pending_connect(wpa_s, nbss);
722 			bss = nbss;
723 			os_memcpy(bss->ies, res + 1,
724 				  res->ie_len + res->beacon_ie_len);
725 			bss->ie_len = res->ie_len;
726 			bss->beacon_ie_len = res->beacon_ie_len;
727 		}
728 		dl_list_add(prev, &bss->list_id);
729 	}
730 	if (changes & WPA_BSS_IES_CHANGED_FLAG)
731 		wpa_bss_set_hessid(bss);
732 	dl_list_add_tail(&wpa_s->bss, &bss->list);
733 
734 	notify_bss_changes(wpa_s, changes, bss);
735 
736 	return bss;
737 }
738 
739 
740 /**
741  * wpa_bss_update_start - Start a BSS table update from scan results
742  * @wpa_s: Pointer to wpa_supplicant data
743  *
744  * This function is called at the start of each BSS table update round for new
745  * scan results. The actual scan result entries are indicated with calls to
746  * wpa_bss_update_scan_res() and the update round is finished with a call to
747  * wpa_bss_update_end().
748  */
wpa_bss_update_start(struct wpa_supplicant * wpa_s)749 void wpa_bss_update_start(struct wpa_supplicant *wpa_s)
750 {
751 	wpa_s->bss_update_idx++;
752 	wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Start scan result update %u",
753 		wpa_s->bss_update_idx);
754 	wpa_s->last_scan_res_used = 0;
755 }
756 
757 
758 /**
759  * wpa_bss_update_scan_res - Update a BSS table entry based on a scan result
760  * @wpa_s: Pointer to wpa_supplicant data
761  * @res: Scan result
762  * @fetch_time: Time when the result was fetched from the driver
763  *
764  * This function updates a BSS table entry (or adds one) based on a scan result.
765  * This is called separately for each scan result between the calls to
766  * wpa_bss_update_start() and wpa_bss_update_end().
767  */
wpa_bss_update_scan_res(struct wpa_supplicant * wpa_s,struct wpa_scan_res * res,struct os_reltime * fetch_time)768 void wpa_bss_update_scan_res(struct wpa_supplicant *wpa_s,
769 			     struct wpa_scan_res *res,
770 			     struct os_reltime *fetch_time)
771 {
772 	const u8 *ssid, *p2p, *mesh;
773 	struct wpa_bss *bss;
774 
775 	if (wpa_s->conf->ignore_old_scan_res) {
776 		struct os_reltime update;
777 		calculate_update_time(fetch_time, res->age, &update);
778 		if (os_reltime_before(&update, &wpa_s->scan_trigger_time)) {
779 			struct os_reltime age;
780 			os_reltime_sub(&wpa_s->scan_trigger_time, &update,
781 				       &age);
782 			wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Ignore driver BSS "
783 				"table entry that is %u.%06u seconds older "
784 				"than our scan trigger",
785 				(unsigned int) age.sec,
786 				(unsigned int) age.usec);
787 			return;
788 		}
789 	}
790 
791 	ssid = wpa_scan_get_ie(res, WLAN_EID_SSID);
792 	if (ssid == NULL) {
793 		wpa_dbg(wpa_s, MSG_DEBUG, "BSS: No SSID IE included for "
794 			MACSTR, MAC2STR(res->bssid));
795 		return;
796 	}
797 	if (ssid[1] > SSID_MAX_LEN) {
798 		wpa_dbg(wpa_s, MSG_DEBUG, "BSS: Too long SSID IE included for "
799 			MACSTR, MAC2STR(res->bssid));
800 		return;
801 	}
802 
803 	p2p = wpa_scan_get_vendor_ie(res, P2P_IE_VENDOR_TYPE);
804 #ifdef CONFIG_P2P
805 	if (p2p == NULL &&
806 	    wpa_s->p2p_group_interface != NOT_P2P_GROUP_INTERFACE) {
807 		/*
808 		 * If it's a P2P specific interface, then don't update
809 		 * the scan result without a P2P IE.
810 		 */
811 		wpa_printf(MSG_DEBUG, "BSS: No P2P IE - skipping BSS " MACSTR
812 			   " update for P2P interface", MAC2STR(res->bssid));
813 		return;
814 	}
815 #endif /* CONFIG_P2P */
816 	if (p2p && ssid[1] == P2P_WILDCARD_SSID_LEN &&
817 	    os_memcmp(ssid + 2, P2P_WILDCARD_SSID, P2P_WILDCARD_SSID_LEN) == 0)
818 		return; /* Skip P2P listen discovery results here */
819 
820 	/* TODO: add option for ignoring BSSes we are not interested in
821 	 * (to save memory) */
822 
823 	mesh = wpa_scan_get_ie(res, WLAN_EID_MESH_ID);
824 	if (mesh && mesh[1] <= SSID_MAX_LEN)
825 		ssid = mesh;
826 
827 	bss = wpa_bss_get(wpa_s, res->bssid, ssid + 2, ssid[1]);
828 	if (bss == NULL)
829 		bss = wpa_bss_add(wpa_s, ssid + 2, ssid[1], res, fetch_time);
830 	else {
831 		bss = wpa_bss_update(wpa_s, bss, res, fetch_time);
832 		if (wpa_s->last_scan_res) {
833 			unsigned int i;
834 			for (i = 0; i < wpa_s->last_scan_res_used; i++) {
835 				if (bss == wpa_s->last_scan_res[i]) {
836 					/* Already in the list */
837 					return;
838 				}
839 			}
840 		}
841 	}
842 
843 	if (bss == NULL)
844 		return;
845 	if (wpa_s->last_scan_res_used >= wpa_s->last_scan_res_size) {
846 		struct wpa_bss **n;
847 		unsigned int siz;
848 		if (wpa_s->last_scan_res_size == 0)
849 			siz = 32;
850 		else
851 			siz = wpa_s->last_scan_res_size * 2;
852 		n = os_realloc_array(wpa_s->last_scan_res, siz,
853 				     sizeof(struct wpa_bss *));
854 		if (n == NULL)
855 			return;
856 		wpa_s->last_scan_res = n;
857 		wpa_s->last_scan_res_size = siz;
858 	}
859 
860 	if (wpa_s->last_scan_res)
861 		wpa_s->last_scan_res[wpa_s->last_scan_res_used++] = bss;
862 }
863 
864 
wpa_bss_included_in_scan(const struct wpa_bss * bss,const struct scan_info * info)865 static int wpa_bss_included_in_scan(const struct wpa_bss *bss,
866 				    const struct scan_info *info)
867 {
868 	int found;
869 	size_t i;
870 
871 	if (info == NULL)
872 		return 1;
873 
874 	if (info->num_freqs) {
875 		found = 0;
876 		for (i = 0; i < info->num_freqs; i++) {
877 			if (bss->freq == info->freqs[i]) {
878 				found = 1;
879 				break;
880 			}
881 		}
882 		if (!found)
883 			return 0;
884 	}
885 
886 	if (info->num_ssids) {
887 		found = 0;
888 		for (i = 0; i < info->num_ssids; i++) {
889 			const struct wpa_driver_scan_ssid *s = &info->ssids[i];
890 			if ((s->ssid == NULL || s->ssid_len == 0) ||
891 			    (s->ssid_len == bss->ssid_len &&
892 			     os_memcmp(s->ssid, bss->ssid, bss->ssid_len) ==
893 			     0)) {
894 				found = 1;
895 				break;
896 			}
897 		}
898 		if (!found)
899 			return 0;
900 	}
901 
902 	return 1;
903 }
904 
905 
906 /**
907  * wpa_bss_update_end - End a BSS table update from scan results
908  * @wpa_s: Pointer to wpa_supplicant data
909  * @info: Information about scan parameters
910  * @new_scan: Whether this update round was based on a new scan
911  *
912  * This function is called at the end of each BSS table update round for new
913  * scan results. The start of the update was indicated with a call to
914  * wpa_bss_update_start().
915  */
wpa_bss_update_end(struct wpa_supplicant * wpa_s,struct scan_info * info,int new_scan)916 void wpa_bss_update_end(struct wpa_supplicant *wpa_s, struct scan_info *info,
917 			int new_scan)
918 {
919 	struct wpa_bss *bss, *n;
920 
921 	os_get_reltime(&wpa_s->last_scan);
922 	if ((info && info->aborted) || !new_scan)
923 		return; /* do not expire entries without new scan */
924 
925 	dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
926 		if (wpa_bss_in_use(wpa_s, bss))
927 			continue;
928 		if (!wpa_bss_included_in_scan(bss, info))
929 			continue; /* expire only BSSes that were scanned */
930 		if (bss->last_update_idx < wpa_s->bss_update_idx)
931 			bss->scan_miss_count++;
932 		if (bss->scan_miss_count >=
933 		    wpa_s->conf->bss_expiration_scan_count) {
934 			wpa_bss_remove(wpa_s, bss, "no match in scan");
935 		}
936 	}
937 
938 	wpa_printf(MSG_DEBUG, "BSS: last_scan_res_used=%zu/%zu",
939 		   wpa_s->last_scan_res_used, wpa_s->last_scan_res_size);
940 }
941 
942 
943 /**
944  * wpa_bss_flush_by_age - Flush old BSS entries
945  * @wpa_s: Pointer to wpa_supplicant data
946  * @age: Maximum entry age in seconds
947  *
948  * Remove BSS entries that have not been updated during the last @age seconds.
949  */
wpa_bss_flush_by_age(struct wpa_supplicant * wpa_s,int age)950 void wpa_bss_flush_by_age(struct wpa_supplicant *wpa_s, int age)
951 {
952 	struct wpa_bss *bss, *n;
953 	struct os_reltime t;
954 
955 	if (dl_list_empty(&wpa_s->bss))
956 		return;
957 
958 	os_get_reltime(&t);
959 	t.sec -= age;
960 
961 	dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
962 		if (wpa_bss_in_use(wpa_s, bss))
963 			continue;
964 
965 		if (os_reltime_before(&bss->last_update, &t)) {
966 			wpa_bss_remove(wpa_s, bss, __func__);
967 		} else
968 			break;
969 	}
970 }
971 
972 
973 /**
974  * wpa_bss_init - Initialize BSS table
975  * @wpa_s: Pointer to wpa_supplicant data
976  * Returns: 0 on success, -1 on failure
977  *
978  * This prepares BSS table lists and timer for periodic updates. The BSS table
979  * is deinitialized with wpa_bss_deinit() once not needed anymore.
980  */
wpa_bss_init(struct wpa_supplicant * wpa_s)981 int wpa_bss_init(struct wpa_supplicant *wpa_s)
982 {
983 	dl_list_init(&wpa_s->bss);
984 	dl_list_init(&wpa_s->bss_id);
985 	return 0;
986 }
987 
988 
989 /**
990  * wpa_bss_flush - Flush all unused BSS entries
991  * @wpa_s: Pointer to wpa_supplicant data
992  */
wpa_bss_flush(struct wpa_supplicant * wpa_s)993 void wpa_bss_flush(struct wpa_supplicant *wpa_s)
994 {
995 	struct wpa_bss *bss, *n;
996 
997 	wpa_s->clear_driver_scan_cache = 1;
998 
999 	if (wpa_s->bss.next == NULL)
1000 		return; /* BSS table not yet initialized */
1001 
1002 	dl_list_for_each_safe(bss, n, &wpa_s->bss, struct wpa_bss, list) {
1003 		if (wpa_bss_in_use(wpa_s, bss))
1004 			continue;
1005 		wpa_bss_remove(wpa_s, bss, __func__);
1006 	}
1007 }
1008 
1009 
1010 /**
1011  * wpa_bss_deinit - Deinitialize BSS table
1012  * @wpa_s: Pointer to wpa_supplicant data
1013  */
wpa_bss_deinit(struct wpa_supplicant * wpa_s)1014 void wpa_bss_deinit(struct wpa_supplicant *wpa_s)
1015 {
1016 	wpa_bss_flush(wpa_s);
1017 }
1018 
1019 
1020 /**
1021  * wpa_bss_get_bssid - Fetch a BSS table entry based on BSSID
1022  * @wpa_s: Pointer to wpa_supplicant data
1023  * @bssid: BSSID
1024  * Returns: Pointer to the BSS entry or %NULL if not found
1025  */
wpa_bss_get_bssid(struct wpa_supplicant * wpa_s,const u8 * bssid)1026 struct wpa_bss * wpa_bss_get_bssid(struct wpa_supplicant *wpa_s,
1027 				   const u8 *bssid)
1028 {
1029 	struct wpa_bss *bss;
1030 	if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
1031 		return NULL;
1032 	dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
1033 		if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0)
1034 			return bss;
1035 	}
1036 	return NULL;
1037 }
1038 
1039 
1040 /**
1041  * wpa_bss_get_bssid_latest - Fetch the latest BSS table entry based on BSSID
1042  * @wpa_s: Pointer to wpa_supplicant data
1043  * @bssid: BSSID
1044  * Returns: Pointer to the BSS entry or %NULL if not found
1045  *
1046  * This function is like wpa_bss_get_bssid(), but full BSS table is iterated to
1047  * find the entry that has the most recent update. This can help in finding the
1048  * correct entry in cases where the SSID of the AP may have changed recently
1049  * (e.g., in WPS reconfiguration cases).
1050  */
wpa_bss_get_bssid_latest(struct wpa_supplicant * wpa_s,const u8 * bssid)1051 struct wpa_bss * wpa_bss_get_bssid_latest(struct wpa_supplicant *wpa_s,
1052 					  const u8 *bssid)
1053 {
1054 	struct wpa_bss *bss, *found = NULL;
1055 	if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
1056 		return NULL;
1057 	dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
1058 		if (os_memcmp(bss->bssid, bssid, ETH_ALEN) != 0)
1059 			continue;
1060 		if (found == NULL ||
1061 		    os_reltime_before(&found->last_update, &bss->last_update))
1062 			found = bss;
1063 	}
1064 	return found;
1065 }
1066 
1067 
1068 #ifdef CONFIG_P2P
1069 /**
1070  * wpa_bss_get_p2p_dev_addr - Fetch the latest BSS table entry based on P2P Device Addr
1071  * @wpa_s: Pointer to wpa_supplicant data
1072  * @dev_addr: P2P Device Address of the GO
1073  * Returns: Pointer to the BSS entry or %NULL if not found
1074  *
1075  * This function tries to find the entry that has the most recent update. This
1076  * can help in finding the correct entry in cases where the SSID of the P2P
1077  * Device may have changed recently.
1078  */
wpa_bss_get_p2p_dev_addr(struct wpa_supplicant * wpa_s,const u8 * dev_addr)1079 struct wpa_bss * wpa_bss_get_p2p_dev_addr(struct wpa_supplicant *wpa_s,
1080 					  const u8 *dev_addr)
1081 {
1082 	struct wpa_bss *bss, *found = NULL;
1083 	dl_list_for_each_reverse(bss, &wpa_s->bss, struct wpa_bss, list) {
1084 		u8 addr[ETH_ALEN];
1085 		if (p2p_parse_dev_addr(wpa_bss_ie_ptr(bss), bss->ie_len,
1086 				       addr) != 0 ||
1087 		    os_memcmp(addr, dev_addr, ETH_ALEN) != 0)
1088 			continue;
1089 		if (!found ||
1090 		    os_reltime_before(&found->last_update, &bss->last_update))
1091 			found = bss;
1092 	}
1093 	return found;
1094 }
1095 #endif /* CONFIG_P2P */
1096 
1097 
1098 /**
1099  * wpa_bss_get_id - Fetch a BSS table entry based on identifier
1100  * @wpa_s: Pointer to wpa_supplicant data
1101  * @id: Unique identifier (struct wpa_bss::id) assigned for the entry
1102  * Returns: Pointer to the BSS entry or %NULL if not found
1103  */
wpa_bss_get_id(struct wpa_supplicant * wpa_s,unsigned int id)1104 struct wpa_bss * wpa_bss_get_id(struct wpa_supplicant *wpa_s, unsigned int id)
1105 {
1106 	struct wpa_bss *bss;
1107 	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
1108 		if (bss->id == id)
1109 			return bss;
1110 	}
1111 	return NULL;
1112 }
1113 
1114 
1115 /**
1116  * wpa_bss_get_id_range - Fetch a BSS table entry based on identifier range
1117  * @wpa_s: Pointer to wpa_supplicant data
1118  * @idf: Smallest allowed identifier assigned for the entry
1119  * @idf: Largest allowed identifier assigned for the entry
1120  * Returns: Pointer to the BSS entry or %NULL if not found
1121  *
1122  * This function is similar to wpa_bss_get_id() but allows a BSS entry with the
1123  * smallest id value to be fetched within the specified range without the
1124  * caller having to know the exact id.
1125  */
wpa_bss_get_id_range(struct wpa_supplicant * wpa_s,unsigned int idf,unsigned int idl)1126 struct wpa_bss * wpa_bss_get_id_range(struct wpa_supplicant *wpa_s,
1127 				      unsigned int idf, unsigned int idl)
1128 {
1129 	struct wpa_bss *bss;
1130 	dl_list_for_each(bss, &wpa_s->bss_id, struct wpa_bss, list_id) {
1131 		if (bss->id >= idf && bss->id <= idl)
1132 			return bss;
1133 	}
1134 	return NULL;
1135 }
1136 
1137 
1138 /**
1139  * wpa_bss_get_ie - Fetch a specified information element from a BSS entry
1140  * @bss: BSS table entry
1141  * @ie: Information element identitifier (WLAN_EID_*)
1142  * Returns: Pointer to the information element (id field) or %NULL if not found
1143  *
1144  * This function returns the first matching information element in the BSS
1145  * entry.
1146  */
wpa_bss_get_ie(const struct wpa_bss * bss,u8 ie)1147 const u8 * wpa_bss_get_ie(const struct wpa_bss *bss, u8 ie)
1148 {
1149 	return get_ie(wpa_bss_ie_ptr(bss), bss->ie_len, ie);
1150 }
1151 
1152 
1153 /**
1154  * wpa_bss_get_ie_ext - Fetch a specified extended IE from a BSS entry
1155  * @bss: BSS table entry
1156  * @ext: Information element extension identifier (WLAN_EID_EXT_*)
1157  * Returns: Pointer to the information element (id field) or %NULL if not found
1158  *
1159  * This function returns the first matching information element in the BSS
1160  * entry.
1161  */
wpa_bss_get_ie_ext(const struct wpa_bss * bss,u8 ext)1162 const u8 * wpa_bss_get_ie_ext(const struct wpa_bss *bss, u8 ext)
1163 {
1164 	return get_ie_ext(wpa_bss_ie_ptr(bss), bss->ie_len, ext);
1165 }
1166 
1167 
1168 /**
1169  * wpa_bss_get_vendor_ie - Fetch a vendor information element from a BSS entry
1170  * @bss: BSS table entry
1171  * @vendor_type: Vendor type (four octets starting the IE payload)
1172  * Returns: Pointer to the information element (id field) or %NULL if not found
1173  *
1174  * This function returns the first matching information element in the BSS
1175  * entry.
1176  */
wpa_bss_get_vendor_ie(const struct wpa_bss * bss,u32 vendor_type)1177 const u8 * wpa_bss_get_vendor_ie(const struct wpa_bss *bss, u32 vendor_type)
1178 {
1179 	const u8 *ies;
1180 	const struct element *elem;
1181 
1182 	ies = wpa_bss_ie_ptr(bss);
1183 
1184 	for_each_element_id(elem, WLAN_EID_VENDOR_SPECIFIC, ies, bss->ie_len) {
1185 		if (elem->datalen >= 4 &&
1186 		    vendor_type == WPA_GET_BE32(elem->data))
1187 			return &elem->id;
1188 	}
1189 
1190 	return NULL;
1191 }
1192 
1193 
1194 /**
1195  * wpa_bss_get_vendor_ie_beacon - Fetch a vendor information from a BSS entry
1196  * @bss: BSS table entry
1197  * @vendor_type: Vendor type (four octets starting the IE payload)
1198  * Returns: Pointer to the information element (id field) or %NULL if not found
1199  *
1200  * This function returns the first matching information element in the BSS
1201  * entry.
1202  *
1203  * This function is like wpa_bss_get_vendor_ie(), but uses IE buffer only
1204  * from Beacon frames instead of either Beacon or Probe Response frames.
1205  */
wpa_bss_get_vendor_ie_beacon(const struct wpa_bss * bss,u32 vendor_type)1206 const u8 * wpa_bss_get_vendor_ie_beacon(const struct wpa_bss *bss,
1207 					u32 vendor_type)
1208 {
1209 	const u8 *ies;
1210 	const struct element *elem;
1211 
1212 	if (bss->beacon_ie_len == 0)
1213 		return NULL;
1214 
1215 	ies = wpa_bss_ie_ptr(bss);
1216 	ies += bss->ie_len;
1217 
1218 	for_each_element_id(elem, WLAN_EID_VENDOR_SPECIFIC, ies,
1219 			    bss->beacon_ie_len) {
1220 		if (elem->datalen >= 4 &&
1221 		    vendor_type == WPA_GET_BE32(elem->data))
1222 			return &elem->id;
1223 	}
1224 
1225 	return NULL;
1226 }
1227 
1228 
1229 /**
1230  * wpa_bss_get_vendor_ie_multi - Fetch vendor IE data from a BSS entry
1231  * @bss: BSS table entry
1232  * @vendor_type: Vendor type (four octets starting the IE payload)
1233  * Returns: Pointer to the information element payload or %NULL if not found
1234  *
1235  * This function returns concatenated payload of possibly fragmented vendor
1236  * specific information elements in the BSS entry. The caller is responsible for
1237  * freeing the returned buffer.
1238  */
wpa_bss_get_vendor_ie_multi(const struct wpa_bss * bss,u32 vendor_type)1239 struct wpabuf * wpa_bss_get_vendor_ie_multi(const struct wpa_bss *bss,
1240 					    u32 vendor_type)
1241 {
1242 	struct wpabuf *buf;
1243 	const u8 *end, *pos;
1244 
1245 	buf = wpabuf_alloc(bss->ie_len);
1246 	if (buf == NULL)
1247 		return NULL;
1248 
1249 	pos = wpa_bss_ie_ptr(bss);
1250 	end = pos + bss->ie_len;
1251 
1252 	while (end - pos > 1) {
1253 		u8 ie, len;
1254 
1255 		ie = pos[0];
1256 		len = pos[1];
1257 		if (len > end - pos - 2)
1258 			break;
1259 		pos += 2;
1260 		if (ie == WLAN_EID_VENDOR_SPECIFIC && len >= 4 &&
1261 		    vendor_type == WPA_GET_BE32(pos))
1262 			wpabuf_put_data(buf, pos + 4, len - 4);
1263 		pos += len;
1264 	}
1265 
1266 	if (wpabuf_len(buf) == 0) {
1267 		wpabuf_free(buf);
1268 		buf = NULL;
1269 	}
1270 
1271 	return buf;
1272 }
1273 
1274 
1275 /**
1276  * wpa_bss_get_vendor_ie_multi_beacon - Fetch vendor IE data from a BSS entry
1277  * @bss: BSS table entry
1278  * @vendor_type: Vendor type (four octets starting the IE payload)
1279  * Returns: Pointer to the information element payload or %NULL if not found
1280  *
1281  * This function returns concatenated payload of possibly fragmented vendor
1282  * specific information elements in the BSS entry. The caller is responsible for
1283  * freeing the returned buffer.
1284  *
1285  * This function is like wpa_bss_get_vendor_ie_multi(), but uses IE buffer only
1286  * from Beacon frames instead of either Beacon or Probe Response frames.
1287  */
wpa_bss_get_vendor_ie_multi_beacon(const struct wpa_bss * bss,u32 vendor_type)1288 struct wpabuf * wpa_bss_get_vendor_ie_multi_beacon(const struct wpa_bss *bss,
1289 						   u32 vendor_type)
1290 {
1291 	struct wpabuf *buf;
1292 	const u8 *end, *pos;
1293 
1294 	buf = wpabuf_alloc(bss->beacon_ie_len);
1295 	if (buf == NULL)
1296 		return NULL;
1297 
1298 	pos = wpa_bss_ie_ptr(bss);
1299 	pos += bss->ie_len;
1300 	end = pos + bss->beacon_ie_len;
1301 
1302 	while (end - pos > 1) {
1303 		if (2 + pos[1] > end - pos)
1304 			break;
1305 		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1306 		    vendor_type == WPA_GET_BE32(&pos[2]))
1307 			wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1308 		pos += 2 + pos[1];
1309 	}
1310 
1311 	if (wpabuf_len(buf) == 0) {
1312 		wpabuf_free(buf);
1313 		buf = NULL;
1314 	}
1315 
1316 	return buf;
1317 }
1318 
1319 
1320 /**
1321  * wpa_bss_get_max_rate - Get maximum legacy TX rate supported in a BSS
1322  * @bss: BSS table entry
1323  * Returns: Maximum legacy rate in units of 500 kbps
1324  */
wpa_bss_get_max_rate(const struct wpa_bss * bss)1325 int wpa_bss_get_max_rate(const struct wpa_bss *bss)
1326 {
1327 	int rate = 0;
1328 	const u8 *ie;
1329 	int i;
1330 
1331 	ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES);
1332 	for (i = 0; ie && i < ie[1]; i++) {
1333 		if ((ie[i + 2] & 0x7f) > rate)
1334 			rate = ie[i + 2] & 0x7f;
1335 	}
1336 
1337 	ie = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES);
1338 	for (i = 0; ie && i < ie[1]; i++) {
1339 		if ((ie[i + 2] & 0x7f) > rate)
1340 			rate = ie[i + 2] & 0x7f;
1341 	}
1342 
1343 	return rate;
1344 }
1345 
1346 
1347 /**
1348  * wpa_bss_get_bit_rates - Get legacy TX rates supported in a BSS
1349  * @bss: BSS table entry
1350  * @rates: Buffer for returning a pointer to the rates list (units of 500 kbps)
1351  * Returns: number of legacy TX rates or -1 on failure
1352  *
1353  * The caller is responsible for freeing the returned buffer with os_free() in
1354  * case of success.
1355  */
wpa_bss_get_bit_rates(const struct wpa_bss * bss,u8 ** rates)1356 int wpa_bss_get_bit_rates(const struct wpa_bss *bss, u8 **rates)
1357 {
1358 	const u8 *ie, *ie2;
1359 	int i, j;
1360 	unsigned int len;
1361 	u8 *r;
1362 
1363 	ie = wpa_bss_get_ie(bss, WLAN_EID_SUPP_RATES);
1364 	ie2 = wpa_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES);
1365 
1366 	len = (ie ? ie[1] : 0) + (ie2 ? ie2[1] : 0);
1367 
1368 	r = os_malloc(len);
1369 	if (!r)
1370 		return -1;
1371 
1372 	for (i = 0; ie && i < ie[1]; i++)
1373 		r[i] = ie[i + 2] & 0x7f;
1374 
1375 	for (j = 0; ie2 && j < ie2[1]; j++)
1376 		r[i + j] = ie2[j + 2] & 0x7f;
1377 
1378 	*rates = r;
1379 	return len;
1380 }
1381 
1382 
1383 #ifdef CONFIG_FILS
wpa_bss_get_fils_cache_id(const struct wpa_bss * bss)1384 const u8 * wpa_bss_get_fils_cache_id(const struct wpa_bss *bss)
1385 {
1386 	const u8 *ie;
1387 
1388 	if (bss) {
1389 		ie = wpa_bss_get_ie(bss, WLAN_EID_FILS_INDICATION);
1390 		if (ie && ie[1] >= 4 && WPA_GET_LE16(ie + 2) & BIT(7))
1391 			return ie + 4;
1392 	}
1393 
1394 	return NULL;
1395 }
1396 #endif /* CONFIG_FILS */
1397 
1398 
wpa_bss_ext_capab(const struct wpa_bss * bss,unsigned int capab)1399 int wpa_bss_ext_capab(const struct wpa_bss *bss, unsigned int capab)
1400 {
1401 	if (!bss)
1402 		return 0;
1403 	return ieee802_11_ext_capab(wpa_bss_get_ie(bss, WLAN_EID_EXT_CAPAB),
1404 				    capab);
1405 }
1406