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1 /*
2  * WPA Supplicant - Scanning
3  * Copyright (c) 2003-2010, 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 "config.h"
15 #include "wpa_supplicant_i.h"
16 #include "driver_i.h"
17 #include "wps_supplicant.h"
18 #include "p2p_supplicant.h"
19 #include "p2p/p2p.h"
20 #include "notify.h"
21 #include "bss.h"
22 #include "scan.h"
23 
24 
wpa_supplicant_gen_assoc_event(struct wpa_supplicant * wpa_s)25 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
26 {
27 	struct wpa_ssid *ssid;
28 	union wpa_event_data data;
29 
30 	ssid = wpa_supplicant_get_ssid(wpa_s);
31 	if (ssid == NULL)
32 		return;
33 
34 	if (wpa_s->current_ssid == NULL) {
35 		wpa_s->current_ssid = ssid;
36 		if (wpa_s->current_ssid != NULL)
37 			wpas_notify_network_changed(wpa_s);
38 	}
39 	wpa_supplicant_initiate_eapol(wpa_s);
40 	wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
41 		"network - generating associated event");
42 	os_memset(&data, 0, sizeof(data));
43 	wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
44 }
45 
46 
47 #ifdef CONFIG_WPS
wpas_wps_in_use(struct wpa_supplicant * wpa_s,enum wps_request_type * req_type)48 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
49 			   enum wps_request_type *req_type)
50 {
51 	struct wpa_ssid *ssid;
52 	int wps = 0;
53 
54 	for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
55 		if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
56 			continue;
57 
58 		wps = 1;
59 		*req_type = wpas_wps_get_req_type(ssid);
60 		if (!ssid->eap.phase1)
61 			continue;
62 
63 		if (os_strstr(ssid->eap.phase1, "pbc=1"))
64 			return 2;
65 	}
66 
67 #ifdef CONFIG_P2P
68 	if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p) {
69 		wpa_s->wps->dev.p2p = 1;
70 		if (!wps) {
71 			wps = 1;
72 			*req_type = WPS_REQ_ENROLLEE_INFO;
73 		}
74 	}
75 #endif /* CONFIG_P2P */
76 
77 	return wps;
78 }
79 #endif /* CONFIG_WPS */
80 
81 
wpa_supplicant_enabled_networks(struct wpa_config * conf)82 int wpa_supplicant_enabled_networks(struct wpa_config *conf)
83 {
84 	struct wpa_ssid *ssid = conf->ssid;
85 	int count = 0;
86 	while (ssid) {
87 		if (!ssid->disabled)
88 			count++;
89 		ssid = ssid->next;
90 	}
91 	return count;
92 }
93 
94 
wpa_supplicant_assoc_try(struct wpa_supplicant * wpa_s,struct wpa_ssid * ssid)95 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
96 				     struct wpa_ssid *ssid)
97 {
98 	while (ssid) {
99 		if (!ssid->disabled)
100 			break;
101 		ssid = ssid->next;
102 	}
103 
104 	/* ap_scan=2 mode - try to associate with each SSID. */
105 	if (ssid == NULL) {
106 		wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
107 			"end of scan list - go back to beginning");
108 		wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
109 		wpa_supplicant_req_scan(wpa_s, 0, 0);
110 		return;
111 	}
112 	if (ssid->next) {
113 		/* Continue from the next SSID on the next attempt. */
114 		wpa_s->prev_scan_ssid = ssid;
115 	} else {
116 		/* Start from the beginning of the SSID list. */
117 		wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
118 	}
119 	wpa_supplicant_associate(wpa_s, NULL, ssid);
120 }
121 
122 
int_array_len(const int * a)123 static int int_array_len(const int *a)
124 {
125 	int i;
126 	for (i = 0; a && a[i]; i++)
127 		;
128 	return i;
129 }
130 
131 
int_array_concat(int ** res,const int * a)132 static void int_array_concat(int **res, const int *a)
133 {
134 	int reslen, alen, i;
135 	int *n;
136 
137 	reslen = int_array_len(*res);
138 	alen = int_array_len(a);
139 
140 	n = os_realloc(*res, (reslen + alen + 1) * sizeof(int));
141 	if (n == NULL) {
142 		os_free(*res);
143 		*res = NULL;
144 		return;
145 	}
146 	for (i = 0; i <= alen; i++)
147 		n[reslen + i] = a[i];
148 	*res = n;
149 }
150 
151 
freq_cmp(const void * a,const void * b)152 static int freq_cmp(const void *a, const void *b)
153 {
154 	int _a = *(int *) a;
155 	int _b = *(int *) b;
156 
157 	if (_a == 0)
158 		return 1;
159 	if (_b == 0)
160 		return -1;
161 	return _a - _b;
162 }
163 
164 
int_array_sort_unique(int * a)165 static void int_array_sort_unique(int *a)
166 {
167 	int alen;
168 	int i, j;
169 
170 	if (a == NULL)
171 		return;
172 
173 	alen = int_array_len(a);
174 	qsort(a, alen, sizeof(int), freq_cmp);
175 
176 	i = 0;
177 	j = 1;
178 	while (a[i] && a[j]) {
179 		if (a[i] == a[j]) {
180 			j++;
181 			continue;
182 		}
183 		a[++i] = a[j++];
184 	}
185 	if (a[i])
186 		i++;
187 	a[i] = 0;
188 }
189 
190 
wpa_supplicant_trigger_scan(struct wpa_supplicant * wpa_s,struct wpa_driver_scan_params * params)191 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
192 				struct wpa_driver_scan_params *params)
193 {
194 	int ret;
195 
196 	wpa_supplicant_notify_scanning(wpa_s, 1);
197 
198 	ret = wpa_drv_scan(wpa_s, params);
199 	if (ret) {
200 		wpa_supplicant_notify_scanning(wpa_s, 0);
201 		wpas_notify_scan_done(wpa_s, 0);
202 	} else {
203 		wpa_s->scan_runs++;
204 		wpa_s->normal_scans++;
205 	}
206 
207 	return ret;
208 }
209 
210 
211 static void
wpa_supplicant_delayed_sched_scan_timeout(void * eloop_ctx,void * timeout_ctx)212 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
213 {
214 	struct wpa_supplicant *wpa_s = eloop_ctx;
215 
216 	wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
217 
218 	if (wpa_supplicant_req_sched_scan(wpa_s))
219 		wpa_supplicant_req_scan(wpa_s, 0, 0);
220 }
221 
222 
223 static void
wpa_supplicant_sched_scan_timeout(void * eloop_ctx,void * timeout_ctx)224 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
225 {
226 	struct wpa_supplicant *wpa_s = eloop_ctx;
227 
228 	wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
229 
230 	wpa_s->sched_scan_timed_out = 1;
231 	wpa_supplicant_cancel_sched_scan(wpa_s);
232 }
233 
234 
235 static int
wpa_supplicant_start_sched_scan(struct wpa_supplicant * wpa_s,struct wpa_driver_scan_params * params,int interval)236 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
237 				struct wpa_driver_scan_params *params,
238 				int interval)
239 {
240 	int ret;
241 #ifndef ANDROID_P2P
242 	wpa_supplicant_notify_scanning(wpa_s, 1);
243 #endif
244 	ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
245 	if (ret)
246 		wpa_supplicant_notify_scanning(wpa_s, 0);
247 	else {
248 		wpa_s->sched_scanning = 1;
249 #ifdef ANDROID_P2P
250 		wpa_supplicant_notify_scanning(wpa_s, 1);
251 #endif
252 	}
253 
254 	return ret;
255 }
256 
257 
wpa_supplicant_stop_sched_scan(struct wpa_supplicant * wpa_s)258 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
259 {
260 	int ret;
261 
262 	ret = wpa_drv_stop_sched_scan(wpa_s);
263 	if (ret) {
264 		wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
265 		/* TODO: what to do if stopping fails? */
266 		return -1;
267 	}
268 
269 	return ret;
270 }
271 
272 
273 static struct wpa_driver_scan_filter *
wpa_supplicant_build_filter_ssids(struct wpa_config * conf,size_t * num_ssids)274 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
275 {
276 	struct wpa_driver_scan_filter *ssids;
277 	struct wpa_ssid *ssid;
278 	size_t count;
279 
280 	*num_ssids = 0;
281 	if (!conf->filter_ssids)
282 		return NULL;
283 
284 	for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
285 		if (ssid->ssid && ssid->ssid_len)
286 			count++;
287 	}
288 	if (count == 0)
289 		return NULL;
290 	ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
291 	if (ssids == NULL)
292 		return NULL;
293 
294 	for (ssid = conf->ssid; ssid; ssid = ssid->next) {
295 		if (!ssid->ssid || !ssid->ssid_len)
296 			continue;
297 		os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
298 		ssids[*num_ssids].ssid_len = ssid->ssid_len;
299 		(*num_ssids)++;
300 	}
301 
302 	return ssids;
303 }
304 
305 
wpa_supplicant_optimize_freqs(struct wpa_supplicant * wpa_s,struct wpa_driver_scan_params * params)306 static void wpa_supplicant_optimize_freqs(
307 	struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
308 {
309 #ifdef CONFIG_P2P
310 	if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
311 	    wpa_s->go_params) {
312 		/* Optimize provisioning state scan based on GO information */
313 		if (wpa_s->p2p_in_provisioning < 5 &&
314 		    wpa_s->go_params->freq > 0) {
315 			wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
316 				"preferred frequency %d MHz",
317 				wpa_s->go_params->freq);
318 			params->freqs = os_zalloc(2 * sizeof(int));
319 			if (params->freqs)
320 				params->freqs[0] = wpa_s->go_params->freq;
321 		} else if (wpa_s->p2p_in_provisioning < 8 &&
322 			   wpa_s->go_params->freq_list[0]) {
323 			wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
324 				"channels");
325 			int_array_concat(&params->freqs,
326 					 wpa_s->go_params->freq_list);
327 			if (params->freqs)
328 				int_array_sort_unique(params->freqs);
329 		}
330 		wpa_s->p2p_in_provisioning++;
331 	}
332 #endif /* CONFIG_P2P */
333 
334 #ifdef CONFIG_WPS
335 	if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
336 		/*
337 		 * Optimize post-provisioning scan based on channel used
338 		 * during provisioning.
339 		 */
340 		wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
341 			"that was used during provisioning", wpa_s->wps_freq);
342 		params->freqs = os_zalloc(2 * sizeof(int));
343 		if (params->freqs)
344 			params->freqs[0] = wpa_s->wps_freq;
345 		wpa_s->after_wps--;
346 	}
347 
348 	if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
349 	{
350 		/* Optimize provisioning scan based on already known channel */
351 		wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
352 			wpa_s->wps_freq);
353 		params->freqs = os_zalloc(2 * sizeof(int));
354 		if (params->freqs)
355 			params->freqs[0] = wpa_s->wps_freq;
356 		wpa_s->known_wps_freq = 0; /* only do this once */
357 	}
358 #endif /* CONFIG_WPS */
359 }
360 
361 
362 #ifdef CONFIG_INTERWORKING
wpas_add_interworking_elements(struct wpa_supplicant * wpa_s,struct wpabuf * buf)363 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
364 					   struct wpabuf *buf)
365 {
366 	if (wpa_s->conf->interworking == 0)
367 		return;
368 
369 	wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
370 	wpabuf_put_u8(buf, 4);
371 	wpabuf_put_u8(buf, 0x00);
372 	wpabuf_put_u8(buf, 0x00);
373 	wpabuf_put_u8(buf, 0x00);
374 	wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
375 
376 	wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
377 	wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
378 		      1 + ETH_ALEN);
379 	wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
380 	/* No Venue Info */
381 	if (!is_zero_ether_addr(wpa_s->conf->hessid))
382 		wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
383 }
384 #endif /* CONFIG_INTERWORKING */
385 
386 
387 static struct wpabuf *
wpa_supplicant_extra_ies(struct wpa_supplicant * wpa_s,struct wpa_driver_scan_params * params)388 wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s,
389 			 struct wpa_driver_scan_params *params)
390 {
391 	struct wpabuf *extra_ie = NULL;
392 #ifdef CONFIG_WPS
393 	int wps = 0;
394 	enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
395 #endif /* CONFIG_WPS */
396 
397 #ifdef CONFIG_INTERWORKING
398 	if (wpa_s->conf->interworking &&
399 	    wpabuf_resize(&extra_ie, 100) == 0)
400 		wpas_add_interworking_elements(wpa_s, extra_ie);
401 #endif /* CONFIG_INTERWORKING */
402 
403 #ifdef CONFIG_WPS
404 	wps = wpas_wps_in_use(wpa_s, &req_type);
405 
406 	if (wps) {
407 		struct wpabuf *wps_ie;
408 		wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
409 						wpa_s->wps->uuid, req_type,
410 						0, NULL);
411 		if (wps_ie) {
412 			if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
413 				wpabuf_put_buf(extra_ie, wps_ie);
414 			wpabuf_free(wps_ie);
415 		}
416 	}
417 
418 #ifdef CONFIG_P2P
419 	if (wps) {
420 		size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
421 		if (wpabuf_resize(&extra_ie, ielen) == 0)
422 			wpas_p2p_scan_ie(wpa_s, extra_ie);
423 	}
424 #endif /* CONFIG_P2P */
425 
426 #endif /* CONFIG_WPS */
427 
428 	return extra_ie;
429 }
430 
431 
wpa_supplicant_scan(void * eloop_ctx,void * timeout_ctx)432 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
433 {
434 	struct wpa_supplicant *wpa_s = eloop_ctx;
435 	struct wpa_ssid *ssid;
436 	int scan_req = 0, ret;
437 	struct wpabuf *extra_ie;
438 	struct wpa_driver_scan_params params;
439 	size_t max_ssids;
440 	enum wpa_states prev_state;
441 
442 	if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
443 		wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
444 		return;
445 	}
446 
447 	if (wpa_s->disconnected && !wpa_s->scan_req) {
448 		wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
449 		return;
450 	}
451 
452 	if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
453 	    !wpa_s->scan_req) {
454 		wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
455 		wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
456 		return;
457 	}
458 
459 	if (wpa_s->conf->ap_scan != 0 &&
460 	    (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
461 		wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
462 			"overriding ap_scan configuration");
463 		wpa_s->conf->ap_scan = 0;
464 		wpas_notify_ap_scan_changed(wpa_s);
465 	}
466 
467 	if (wpa_s->conf->ap_scan == 0) {
468 		wpa_supplicant_gen_assoc_event(wpa_s);
469 		return;
470 	}
471 
472 #ifdef CONFIG_P2P
473 	if (wpas_p2p_in_progress(wpa_s)) {
474 		if (wpa_s->wpa_state == WPA_SCANNING) {
475 			wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
476 				"while P2P operation is in progress");
477 			wpa_supplicant_req_scan(wpa_s, 5, 0);
478 		} else {
479 			wpa_dbg(wpa_s, MSG_DEBUG, "Do not request scan while "
480 				"P2P operation is in progress");
481 		}
482 		return;
483 	}
484 #endif /* CONFIG_P2P */
485 
486 	if (wpa_s->conf->ap_scan == 2)
487 		max_ssids = 1;
488 	else {
489 		max_ssids = wpa_s->max_scan_ssids;
490 		if (max_ssids > WPAS_MAX_SCAN_SSIDS)
491 			max_ssids = WPAS_MAX_SCAN_SSIDS;
492 	}
493 
494 	scan_req = wpa_s->scan_req;
495 	wpa_s->scan_req = 0;
496 
497 	os_memset(&params, 0, sizeof(params));
498 
499 	prev_state = wpa_s->wpa_state;
500 	if (wpa_s->wpa_state == WPA_DISCONNECTED ||
501 	    wpa_s->wpa_state == WPA_INACTIVE)
502 		wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
503 
504 	if (scan_req != 2 && wpa_s->connect_without_scan) {
505 		for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
506 			if (ssid == wpa_s->connect_without_scan)
507 				break;
508 		}
509 		wpa_s->connect_without_scan = NULL;
510 		if (ssid) {
511 			wpa_printf(MSG_DEBUG, "Start a pre-selected network "
512 				   "without scan step");
513 			wpa_supplicant_associate(wpa_s, NULL, ssid);
514 			return;
515 		}
516 	}
517 
518 	/* Find the starting point from which to continue scanning */
519 	ssid = wpa_s->conf->ssid;
520 	if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
521 		while (ssid) {
522 			if (ssid == wpa_s->prev_scan_ssid) {
523 				ssid = ssid->next;
524 				break;
525 			}
526 			ssid = ssid->next;
527 		}
528 	}
529 
530 	if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
531 		wpa_s->connect_without_scan = NULL;
532 		wpa_s->prev_scan_wildcard = 0;
533 		wpa_supplicant_assoc_try(wpa_s, ssid);
534 		return;
535 #ifndef ANDROID
536 	} else if (wpa_s->conf->ap_scan == 2) {
537 		/*
538 		 * User-initiated scan request in ap_scan == 2; scan with
539 		 * wildcard SSID.
540 		 */
541 		ssid = NULL;
542 #endif
543 	} else {
544 		struct wpa_ssid *start = ssid, *tssid;
545 		int freqs_set = 0;
546 		if (ssid == NULL && max_ssids > 1)
547 			ssid = wpa_s->conf->ssid;
548 		while (ssid) {
549 			if (!ssid->disabled && ssid->scan_ssid) {
550 				wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
551 						  ssid->ssid, ssid->ssid_len);
552 				params.ssids[params.num_ssids].ssid =
553 					ssid->ssid;
554 				params.ssids[params.num_ssids].ssid_len =
555 					ssid->ssid_len;
556 				params.num_ssids++;
557 				if (params.num_ssids + 1 >= max_ssids)
558 					break;
559 			}
560 			ssid = ssid->next;
561 			if (ssid == start)
562 				break;
563 			if (ssid == NULL && max_ssids > 1 &&
564 			    start != wpa_s->conf->ssid)
565 				ssid = wpa_s->conf->ssid;
566 		}
567 
568 		for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
569 			if (tssid->disabled)
570 				continue;
571 			if ((params.freqs || !freqs_set) && tssid->scan_freq) {
572 				int_array_concat(&params.freqs,
573 						 tssid->scan_freq);
574 			} else {
575 				os_free(params.freqs);
576 				params.freqs = NULL;
577 			}
578 			freqs_set = 1;
579 		}
580 		int_array_sort_unique(params.freqs);
581 	}
582 
583 	if (ssid && max_ssids == 1) {
584 		/*
585 		 * If the driver is limited to 1 SSID at a time interleave
586 		 * wildcard SSID scans with specific SSID scans to avoid
587 		 * waiting a long time for a wildcard scan.
588 		 */
589 		if (!wpa_s->prev_scan_wildcard) {
590 			params.ssids[0].ssid = NULL;
591 			params.ssids[0].ssid_len = 0;
592 			wpa_s->prev_scan_wildcard = 1;
593 			wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
594 				"wildcard SSID (Interleave with specific)");
595 		} else {
596 			wpa_s->prev_scan_ssid = ssid;
597 			wpa_s->prev_scan_wildcard = 0;
598 			wpa_dbg(wpa_s, MSG_DEBUG,
599 				"Starting AP scan for specific SSID: %s",
600 				wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
601 		}
602 	} else if (ssid) {
603 		/* max_ssids > 1 */
604 
605 		wpa_s->prev_scan_ssid = ssid;
606 		wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
607 			"the scan request");
608 		params.num_ssids++;
609 	} else {
610 		wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
611 		params.num_ssids++;
612 		wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
613 			"SSID");
614 	}
615 
616 	wpa_supplicant_optimize_freqs(wpa_s, &params);
617 	extra_ie = wpa_supplicant_extra_ies(wpa_s, &params);
618 
619 	if (params.freqs == NULL && wpa_s->next_scan_freqs) {
620 		wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
621 			"generated frequency list");
622 		params.freqs = wpa_s->next_scan_freqs;
623 	} else
624 		os_free(wpa_s->next_scan_freqs);
625 	wpa_s->next_scan_freqs = NULL;
626 
627 	params.filter_ssids = wpa_supplicant_build_filter_ssids(
628 		wpa_s->conf, &params.num_filter_ssids);
629 	if (extra_ie) {
630 		params.extra_ies = wpabuf_head(extra_ie);
631 		params.extra_ies_len = wpabuf_len(extra_ie);
632 	}
633 
634 #ifdef CONFIG_P2P
635 	if (wpa_s->p2p_in_provisioning) {
636 		/*
637 		 * The interface may not yet be in P2P mode, so we have to
638 		 * explicitly request P2P probe to disable CCK rates.
639 		 */
640 		params.p2p_probe = 1;
641 	}
642 #endif /* CONFIG_P2P */
643 
644 	ret = wpa_supplicant_trigger_scan(wpa_s, &params);
645 
646 	wpabuf_free(extra_ie);
647 	os_free(params.freqs);
648 	os_free(params.filter_ssids);
649 
650 	if (ret) {
651 		wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
652 		if (prev_state != wpa_s->wpa_state)
653 			wpa_supplicant_set_state(wpa_s, prev_state);
654 		wpa_supplicant_req_scan(wpa_s, 1, 0);
655 	}
656 }
657 
658 
659 /**
660  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
661  * @wpa_s: Pointer to wpa_supplicant data
662  * @sec: Number of seconds after which to scan
663  * @usec: Number of microseconds after which to scan
664  *
665  * This function is used to schedule a scan for neighboring access points after
666  * the specified time.
667  */
wpa_supplicant_req_scan(struct wpa_supplicant * wpa_s,int sec,int usec)668 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
669 {
670 #ifndef ANDROID
671 	/* If there's at least one network that should be specifically scanned
672 	 * then don't cancel the scan and reschedule.  Some drivers do
673 	 * background scanning which generates frequent scan results, and that
674 	 * causes the specific SSID scan to get continually pushed back and
675 	 * never happen, which causes hidden APs to never get probe-scanned.
676 	 */
677 	if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
678 	    wpa_s->conf->ap_scan == 1) {
679 		struct wpa_ssid *ssid = wpa_s->conf->ssid;
680 
681 		while (ssid) {
682 			if (!ssid->disabled && ssid->scan_ssid)
683 				break;
684 			ssid = ssid->next;
685 		}
686 		if (ssid) {
687 			wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
688 			        "ensure that specific SSID scans occur");
689 			return;
690 		}
691 	}
692 #endif
693 	wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
694 		sec, usec);
695 	eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
696 	eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
697 }
698 
699 
700 /**
701  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
702  * @wpa_s: Pointer to wpa_supplicant data
703  * @sec: Number of seconds after which to scan
704  * @usec: Number of microseconds after which to scan
705  *
706  * This function is used to schedule periodic scans for neighboring
707  * access points after the specified time.
708  */
wpa_supplicant_delayed_sched_scan(struct wpa_supplicant * wpa_s,int sec,int usec)709 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
710 				      int sec, int usec)
711 {
712 	if (!wpa_s->sched_scan_supported)
713 		return -1;
714 
715 	eloop_register_timeout(sec, usec,
716 			       wpa_supplicant_delayed_sched_scan_timeout,
717 			       wpa_s, NULL);
718 
719 	return 0;
720 }
721 
722 
723 /**
724  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
725  * @wpa_s: Pointer to wpa_supplicant data
726  *
727  * This function is used to schedule periodic scans for neighboring
728  * access points repeating the scan continuously.
729  */
wpa_supplicant_req_sched_scan(struct wpa_supplicant * wpa_s)730 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
731 {
732 	struct wpa_driver_scan_params params;
733 	enum wpa_states prev_state;
734 	struct wpa_ssid *ssid;
735 	struct wpabuf *wps_ie = NULL;
736 	int ret;
737 	unsigned int max_sched_scan_ssids;
738 	int wildcard = 0;
739 	int need_ssids;
740 
741 	if (!wpa_s->sched_scan_supported)
742 		return -1;
743 
744 	if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
745 		max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
746 	else
747 		max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
748 	if (max_sched_scan_ssids < 1)
749 		return -1;
750 
751 	if (wpa_s->sched_scanning) {
752 		wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
753 		return 0;
754 	}
755 
756 	need_ssids = 0;
757 	for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
758 		if (!ssid->disabled && !ssid->scan_ssid) {
759 			/* Use wildcard SSID to find this network */
760 			wildcard = 1;
761 		} else if (!ssid->disabled && ssid->ssid_len)
762 			need_ssids++;
763 	}
764 	if (wildcard)
765 		need_ssids++;
766 
767 	if (wpa_s->normal_scans < 3 &&
768 	    (need_ssids <= wpa_s->max_scan_ssids ||
769 	     wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
770 		/*
771 		 * When normal scan can speed up operations, use that for the
772 		 * first operations before starting the sched_scan to allow
773 		 * user space sleep more. We do this only if the normal scan
774 		 * has functionality that is suitable for this or if the
775 		 * sched_scan does not have better support for multiple SSIDs.
776 		 */
777 		wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
778 			"sched_scan for initial scans (normal_scans=%d)",
779 			wpa_s->normal_scans);
780 		return -1;
781 	}
782 
783 	os_memset(&params, 0, sizeof(params));
784 
785 	/* If we can't allocate space for the filters, we just don't filter */
786 	params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
787 					sizeof(struct wpa_driver_scan_filter));
788 
789 	prev_state = wpa_s->wpa_state;
790 #ifndef ANDROID_P2P
791 	if (wpa_s->wpa_state == WPA_DISCONNECTED ||
792 	    wpa_s->wpa_state == WPA_INACTIVE)
793 		wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
794 #endif
795 
796 	/* Find the starting point from which to continue scanning */
797 	ssid = wpa_s->conf->ssid;
798 	if (wpa_s->prev_sched_ssid) {
799 		while (ssid) {
800 			if (ssid == wpa_s->prev_sched_ssid) {
801 				ssid = ssid->next;
802 				break;
803 			}
804 			ssid = ssid->next;
805 		}
806 	}
807 
808 	if (!ssid || !wpa_s->prev_sched_ssid) {
809 		wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
810 
811 		wpa_s->sched_scan_interval = 10;
812 		wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
813 		wpa_s->first_sched_scan = 1;
814 		ssid = wpa_s->conf->ssid;
815 		wpa_s->prev_sched_ssid = ssid;
816 	}
817 
818 	if (wildcard) {
819 		wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
820 		params.num_ssids++;
821 	}
822 
823 	while (ssid) {
824 		if (ssid->disabled)
825 			goto next;
826 
827 		if (params.num_filter_ssids < wpa_s->max_match_sets &&
828 		    params.filter_ssids && ssid->ssid && ssid->ssid_len) {
829 			wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
830 				wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
831 			os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
832 				  ssid->ssid, ssid->ssid_len);
833 			params.filter_ssids[params.num_filter_ssids].ssid_len =
834 				ssid->ssid_len;
835 			params.num_filter_ssids++;
836 		} else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
837 		{
838 			wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
839 				"filter for sched_scan - drop filter");
840 			os_free(params.filter_ssids);
841 			params.filter_ssids = NULL;
842 			params.num_filter_ssids = 0;
843 		}
844 
845 		if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
846 			if (params.num_ssids == max_sched_scan_ssids)
847 				break; /* only room for broadcast SSID */
848 			wpa_dbg(wpa_s, MSG_DEBUG,
849 				"add to active scan ssid: %s",
850 				wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
851 			params.ssids[params.num_ssids].ssid =
852 				ssid->ssid;
853 			params.ssids[params.num_ssids].ssid_len =
854 				ssid->ssid_len;
855 			params.num_ssids++;
856 			if (params.num_ssids >= max_sched_scan_ssids) {
857 				wpa_s->prev_sched_ssid = ssid;
858 				break;
859 			}
860 		}
861 
862 	next:
863 		wpa_s->prev_sched_ssid = ssid;
864 		ssid = ssid->next;
865 	}
866 
867 	if (params.num_filter_ssids == 0) {
868 		os_free(params.filter_ssids);
869 		params.filter_ssids = NULL;
870 	}
871 
872 	if (wpa_s->wps)
873 		wps_ie = wpa_supplicant_extra_ies(wpa_s, &params);
874 
875 	if (ssid || !wpa_s->first_sched_scan) {
876 		wpa_dbg(wpa_s, MSG_DEBUG,
877 			"Starting sched scan: interval %d (no timeout)",
878 			wpa_s->sched_scan_interval);
879 	} else {
880 		wpa_dbg(wpa_s, MSG_DEBUG,
881 			"Starting sched scan: interval %d timeout %d",
882 			wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
883 	}
884 
885 	ret = wpa_supplicant_start_sched_scan(wpa_s, &params,
886 					      wpa_s->sched_scan_interval);
887 	wpabuf_free(wps_ie);
888 	os_free(params.filter_ssids);
889 	if (ret) {
890 		wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
891 		if (prev_state != wpa_s->wpa_state)
892 			wpa_supplicant_set_state(wpa_s, prev_state);
893 		return ret;
894 	}
895 
896 	/* If we have more SSIDs to scan, add a timeout so we scan them too */
897 	if (ssid || !wpa_s->first_sched_scan) {
898 		wpa_s->sched_scan_timed_out = 0;
899 		eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
900 				       wpa_supplicant_sched_scan_timeout,
901 				       wpa_s, NULL);
902 		wpa_s->first_sched_scan = 0;
903 		wpa_s->sched_scan_timeout /= 2;
904 		wpa_s->sched_scan_interval *= 2;
905 	}
906 
907 	return 0;
908 }
909 
910 
911 /**
912  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
913  * @wpa_s: Pointer to wpa_supplicant data
914  *
915  * This function is used to cancel a scan request scheduled with
916  * wpa_supplicant_req_scan().
917  */
wpa_supplicant_cancel_scan(struct wpa_supplicant * wpa_s)918 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
919 {
920 	wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
921 	eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
922 #ifdef ANDROID
923 	wpa_supplicant_notify_scanning(wpa_s, 0);
924 #endif
925 }
926 
927 
928 /**
929  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
930  * @wpa_s: Pointer to wpa_supplicant data
931  *
932  * This function is used to stop a periodic scheduled scan.
933  */
wpa_supplicant_cancel_sched_scan(struct wpa_supplicant * wpa_s)934 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
935 {
936 	if (!wpa_s->sched_scanning)
937 		return;
938 
939 	wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
940 	eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
941 	wpa_supplicant_stop_sched_scan(wpa_s);
942 }
943 
944 
wpa_supplicant_notify_scanning(struct wpa_supplicant * wpa_s,int scanning)945 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
946 				    int scanning)
947 {
948 	if (wpa_s->scanning != scanning) {
949 #ifdef ANDROID_P2P
950 		if(!wpa_s->sched_scanning)
951 			wpa_s->scanning = scanning;
952 #else
953 		wpa_s->scanning = scanning;
954 #endif
955 		wpas_notify_scanning(wpa_s);
956 	}
957 }
958 
959 
wpa_scan_get_max_rate(const struct wpa_scan_res * res)960 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
961 {
962 	int rate = 0;
963 	const u8 *ie;
964 	int i;
965 
966 	ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
967 	for (i = 0; ie && i < ie[1]; i++) {
968 		if ((ie[i + 2] & 0x7f) > rate)
969 			rate = ie[i + 2] & 0x7f;
970 	}
971 
972 	ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
973 	for (i = 0; ie && i < ie[1]; i++) {
974 		if ((ie[i + 2] & 0x7f) > rate)
975 			rate = ie[i + 2] & 0x7f;
976 	}
977 
978 	return rate;
979 }
980 
981 
wpa_scan_get_ie(const struct wpa_scan_res * res,u8 ie)982 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
983 {
984 	const u8 *end, *pos;
985 
986 	pos = (const u8 *) (res + 1);
987 	end = pos + res->ie_len;
988 
989 	while (pos + 1 < end) {
990 		if (pos + 2 + pos[1] > end)
991 			break;
992 		if (pos[0] == ie)
993 			return pos;
994 		pos += 2 + pos[1];
995 	}
996 
997 	return NULL;
998 }
999 
1000 
wpa_scan_get_vendor_ie(const struct wpa_scan_res * res,u32 vendor_type)1001 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1002 				  u32 vendor_type)
1003 {
1004 	const u8 *end, *pos;
1005 
1006 	pos = (const u8 *) (res + 1);
1007 	end = pos + res->ie_len;
1008 
1009 	while (pos + 1 < end) {
1010 		if (pos + 2 + pos[1] > end)
1011 			break;
1012 		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1013 		    vendor_type == WPA_GET_BE32(&pos[2]))
1014 			return pos;
1015 		pos += 2 + pos[1];
1016 	}
1017 
1018 	return NULL;
1019 }
1020 
1021 
wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res * res,u32 vendor_type)1022 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1023 					     u32 vendor_type)
1024 {
1025 	struct wpabuf *buf;
1026 	const u8 *end, *pos;
1027 
1028 	buf = wpabuf_alloc(res->ie_len);
1029 	if (buf == NULL)
1030 		return NULL;
1031 
1032 	pos = (const u8 *) (res + 1);
1033 	end = pos + res->ie_len;
1034 
1035 	while (pos + 1 < end) {
1036 		if (pos + 2 + pos[1] > end)
1037 			break;
1038 		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1039 		    vendor_type == WPA_GET_BE32(&pos[2]))
1040 			wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1041 		pos += 2 + pos[1];
1042 	}
1043 
1044 	if (wpabuf_len(buf) == 0) {
1045 		wpabuf_free(buf);
1046 		buf = NULL;
1047 	}
1048 
1049 	return buf;
1050 }
1051 
1052 
wpa_scan_get_vendor_ie_multi_beacon(const struct wpa_scan_res * res,u32 vendor_type)1053 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1054 	const struct wpa_scan_res *res, u32 vendor_type)
1055 {
1056 	struct wpabuf *buf;
1057 	const u8 *end, *pos;
1058 
1059 	if (res->beacon_ie_len == 0)
1060 		return NULL;
1061 	buf = wpabuf_alloc(res->beacon_ie_len);
1062 	if (buf == NULL)
1063 		return NULL;
1064 
1065 	pos = (const u8 *) (res + 1);
1066 	pos += res->ie_len;
1067 	end = pos + res->beacon_ie_len;
1068 
1069 	while (pos + 1 < end) {
1070 		if (pos + 2 + pos[1] > end)
1071 			break;
1072 		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1073 		    vendor_type == WPA_GET_BE32(&pos[2]))
1074 			wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1075 		pos += 2 + pos[1];
1076 	}
1077 
1078 	if (wpabuf_len(buf) == 0) {
1079 		wpabuf_free(buf);
1080 		buf = NULL;
1081 	}
1082 
1083 	return buf;
1084 }
1085 
1086 
1087 /*
1088  * Channels with a great SNR can operate at full rate. What is a great SNR?
1089  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1090  * rule of thumb is that any SNR above 20 is good." This one
1091  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1092  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1093  * conservative value.
1094  */
1095 #define GREAT_SNR 30
1096 
1097 /* Compare function for sorting scan results. Return >0 if @b is considered
1098  * better. */
wpa_scan_result_compar(const void * a,const void * b)1099 static int wpa_scan_result_compar(const void *a, const void *b)
1100 {
1101 #define IS_5GHZ(n) (n > 4000)
1102 #define MIN(a,b) a < b ? a : b
1103 	struct wpa_scan_res **_wa = (void *) a;
1104 	struct wpa_scan_res **_wb = (void *) b;
1105 	struct wpa_scan_res *wa = *_wa;
1106 	struct wpa_scan_res *wb = *_wb;
1107 	int wpa_a, wpa_b, maxrate_a, maxrate_b;
1108 	int snr_a, snr_b;
1109 
1110 	/* WPA/WPA2 support preferred */
1111 	wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1112 		wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1113 	wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1114 		wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1115 
1116 	if (wpa_b && !wpa_a)
1117 		return 1;
1118 	if (!wpa_b && wpa_a)
1119 		return -1;
1120 
1121 	/* privacy support preferred */
1122 	if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1123 	    (wb->caps & IEEE80211_CAP_PRIVACY))
1124 		return 1;
1125 	if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1126 	    (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1127 		return -1;
1128 
1129 	if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1130 	    !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1131 		snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1132 		snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1133 	} else {
1134 		/* Not suitable information to calculate SNR, so use level */
1135 		snr_a = wa->level;
1136 		snr_b = wb->level;
1137 	}
1138 
1139 	/* best/max rate preferred if SNR close enough */
1140         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1141 	    (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1142 		maxrate_a = wpa_scan_get_max_rate(wa);
1143 		maxrate_b = wpa_scan_get_max_rate(wb);
1144 		if (maxrate_a != maxrate_b)
1145 			return maxrate_b - maxrate_a;
1146 		if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1147 			return IS_5GHZ(wa->freq) ? -1 : 1;
1148 	}
1149 
1150 	/* use freq for channel preference */
1151 
1152 	/* all things being equal, use SNR; if SNRs are
1153 	 * identical, use quality values since some drivers may only report
1154 	 * that value and leave the signal level zero */
1155 	if (snr_b == snr_a)
1156 		return wb->qual - wa->qual;
1157 	return snr_b - snr_a;
1158 #undef MIN
1159 #undef IS_5GHZ
1160 }
1161 
1162 
1163 #ifdef CONFIG_WPS
1164 /* Compare function for sorting scan results when searching a WPS AP for
1165  * provisioning. Return >0 if @b is considered better. */
wpa_scan_result_wps_compar(const void * a,const void * b)1166 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1167 {
1168 	struct wpa_scan_res **_wa = (void *) a;
1169 	struct wpa_scan_res **_wb = (void *) b;
1170 	struct wpa_scan_res *wa = *_wa;
1171 	struct wpa_scan_res *wb = *_wb;
1172 	int uses_wps_a, uses_wps_b;
1173 	struct wpabuf *wps_a, *wps_b;
1174 	int res;
1175 
1176 	/* Optimization - check WPS IE existence before allocated memory and
1177 	 * doing full reassembly. */
1178 	uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1179 	uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1180 	if (uses_wps_a && !uses_wps_b)
1181 		return -1;
1182 	if (!uses_wps_a && uses_wps_b)
1183 		return 1;
1184 
1185 	if (uses_wps_a && uses_wps_b) {
1186 		wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1187 		wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1188 		res = wps_ap_priority_compar(wps_a, wps_b);
1189 		wpabuf_free(wps_a);
1190 		wpabuf_free(wps_b);
1191 		if (res)
1192 			return res;
1193 	}
1194 
1195 	/*
1196 	 * Do not use current AP security policy as a sorting criteria during
1197 	 * WPS provisioning step since the AP may get reconfigured at the
1198 	 * completion of provisioning.
1199 	 */
1200 
1201 	/* all things being equal, use signal level; if signal levels are
1202 	 * identical, use quality values since some drivers may only report
1203 	 * that value and leave the signal level zero */
1204 	if (wb->level == wa->level)
1205 		return wb->qual - wa->qual;
1206 	return wb->level - wa->level;
1207 }
1208 #endif /* CONFIG_WPS */
1209 
1210 
dump_scan_res(struct wpa_scan_results * scan_res)1211 static void dump_scan_res(struct wpa_scan_results *scan_res)
1212 {
1213 #ifndef CONFIG_NO_STDOUT_DEBUG
1214 	size_t i;
1215 
1216 	if (scan_res->res == NULL || scan_res->num == 0)
1217 		return;
1218 
1219 	wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1220 
1221 	for (i = 0; i < scan_res->num; i++) {
1222 		struct wpa_scan_res *r = scan_res->res[i];
1223 		if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1224 		    == WPA_SCAN_LEVEL_DBM) {
1225 			int snr = r->level - r->noise;
1226 			wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1227 				   "noise=%d level=%d snr=%d%s flags=0x%x",
1228 				   MAC2STR(r->bssid), r->freq, r->qual,
1229 				   r->noise, r->level, snr,
1230 				   snr >= GREAT_SNR ? "*" : "", r->flags);
1231 		} else {
1232 			wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1233 				   "noise=%d level=%d flags=0x%x",
1234 				   MAC2STR(r->bssid), r->freq, r->qual,
1235 				   r->noise, r->level, r->flags);
1236 		}
1237 	}
1238 #endif /* CONFIG_NO_STDOUT_DEBUG */
1239 }
1240 
1241 
1242 /**
1243  * wpa_supplicant_get_scan_results - Get scan results
1244  * @wpa_s: Pointer to wpa_supplicant data
1245  * @info: Information about what was scanned or %NULL if not available
1246  * @new_scan: Whether a new scan was performed
1247  * Returns: Scan results, %NULL on failure
1248  *
1249  * This function request the current scan results from the driver and updates
1250  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1251  * results with wpa_scan_results_free().
1252  */
1253 struct wpa_scan_results *
wpa_supplicant_get_scan_results(struct wpa_supplicant * wpa_s,struct scan_info * info,int new_scan)1254 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1255 				struct scan_info *info, int new_scan)
1256 {
1257 	struct wpa_scan_results *scan_res;
1258 	size_t i;
1259 	int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1260 
1261 	scan_res = wpa_drv_get_scan_results2(wpa_s);
1262 	if (scan_res == NULL) {
1263 		wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1264 		return NULL;
1265 	}
1266 
1267 #ifdef CONFIG_WPS
1268 	if (wpas_wps_in_progress(wpa_s)) {
1269 		wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1270 			"provisioning rules");
1271 		compar = wpa_scan_result_wps_compar;
1272 	}
1273 #endif /* CONFIG_WPS */
1274 
1275 	qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1276 	      compar);
1277 	dump_scan_res(scan_res);
1278 
1279 	wpa_bss_update_start(wpa_s);
1280 	for (i = 0; i < scan_res->num; i++)
1281 		wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1282 	wpa_bss_update_end(wpa_s, info, new_scan);
1283 
1284 	return scan_res;
1285 }
1286 
1287 
wpa_supplicant_update_scan_results(struct wpa_supplicant * wpa_s)1288 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1289 {
1290 	struct wpa_scan_results *scan_res;
1291 	scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1292 	if (scan_res == NULL)
1293 		return -1;
1294 	wpa_scan_results_free(scan_res);
1295 
1296 	return 0;
1297 }
1298