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P2P: Avoid multi-channel scans when they are not needed
[thirdparty/hostap.git] / wpa_supplicant / scan.c
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 "hs20_supplicant.h"
21 #include "notify.h"
22 #include "bss.h"
23 #include "scan.h"
24
25
26 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
27 {
28 struct wpa_ssid *ssid;
29 union wpa_event_data data;
30
31 ssid = wpa_supplicant_get_ssid(wpa_s);
32 if (ssid == NULL)
33 return;
34
35 if (wpa_s->current_ssid == NULL) {
36 wpa_s->current_ssid = ssid;
37 if (wpa_s->current_ssid != NULL)
38 wpas_notify_network_changed(wpa_s);
39 }
40 wpa_supplicant_initiate_eapol(wpa_s);
41 wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
42 "network - generating associated event");
43 os_memset(&data, 0, sizeof(data));
44 wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
45 }
46
47
48 #ifdef CONFIG_WPS
49 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
50 enum wps_request_type *req_type)
51 {
52 struct wpa_ssid *ssid;
53 int wps = 0;
54
55 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
56 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
57 continue;
58
59 wps = 1;
60 *req_type = wpas_wps_get_req_type(ssid);
61 if (!ssid->eap.phase1)
62 continue;
63
64 if (os_strstr(ssid->eap.phase1, "pbc=1"))
65 return 2;
66 }
67
68 #ifdef CONFIG_P2P
69 if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p &&
70 !wpa_s->conf->p2p_disabled) {
71 wpa_s->wps->dev.p2p = 1;
72 if (!wps) {
73 wps = 1;
74 *req_type = WPS_REQ_ENROLLEE_INFO;
75 }
76 }
77 #endif /* CONFIG_P2P */
78
79 return wps;
80 }
81 #endif /* CONFIG_WPS */
82
83
84 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
85 {
86 struct wpa_ssid *ssid = wpa_s->conf->ssid;
87 int count = 0, disabled = 0;
88 while (ssid) {
89 if (!wpas_network_disabled(wpa_s, ssid))
90 count++;
91 else
92 disabled++;
93 ssid = ssid->next;
94 }
95 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
96 wpa_s->conf->auto_interworking)
97 count++;
98 if (count == 0 && disabled > 0) {
99 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled "
100 "networks)", disabled);
101 }
102 return count;
103 }
104
105
106 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
107 struct wpa_ssid *ssid)
108 {
109 while (ssid) {
110 if (!wpas_network_disabled(wpa_s, ssid))
111 break;
112 ssid = ssid->next;
113 }
114
115 /* ap_scan=2 mode - try to associate with each SSID. */
116 if (ssid == NULL) {
117 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
118 "end of scan list - go back to beginning");
119 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
120 wpa_supplicant_req_scan(wpa_s, 0, 0);
121 return;
122 }
123 if (ssid->next) {
124 /* Continue from the next SSID on the next attempt. */
125 wpa_s->prev_scan_ssid = ssid;
126 } else {
127 /* Start from the beginning of the SSID list. */
128 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
129 }
130 wpa_supplicant_associate(wpa_s, NULL, ssid);
131 }
132
133
134 static int int_array_len(const int *a)
135 {
136 int i;
137 for (i = 0; a && a[i]; i++)
138 ;
139 return i;
140 }
141
142
143 static void int_array_concat(int **res, const int *a)
144 {
145 int reslen, alen, i;
146 int *n;
147
148 reslen = int_array_len(*res);
149 alen = int_array_len(a);
150
151 n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
152 if (n == NULL) {
153 os_free(*res);
154 *res = NULL;
155 return;
156 }
157 for (i = 0; i <= alen; i++)
158 n[reslen + i] = a[i];
159 *res = n;
160 }
161
162
163 static int freq_cmp(const void *a, const void *b)
164 {
165 int _a = *(int *) a;
166 int _b = *(int *) b;
167
168 if (_a == 0)
169 return 1;
170 if (_b == 0)
171 return -1;
172 return _a - _b;
173 }
174
175
176 static void int_array_sort_unique(int *a)
177 {
178 int alen;
179 int i, j;
180
181 if (a == NULL)
182 return;
183
184 alen = int_array_len(a);
185 qsort(a, alen, sizeof(int), freq_cmp);
186
187 i = 0;
188 j = 1;
189 while (a[i] && a[j]) {
190 if (a[i] == a[j]) {
191 j++;
192 continue;
193 }
194 a[++i] = a[j++];
195 }
196 if (a[i])
197 i++;
198 a[i] = 0;
199 }
200
201
202 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
203 struct wpa_driver_scan_params *params)
204 {
205 int ret;
206
207 wpa_supplicant_notify_scanning(wpa_s, 1);
208
209 ret = wpa_drv_scan(wpa_s, params);
210 if (ret) {
211 wpa_supplicant_notify_scanning(wpa_s, 0);
212 wpas_notify_scan_done(wpa_s, 0);
213 } else {
214 wpa_s->scan_runs++;
215 wpa_s->normal_scans++;
216 }
217
218 return ret;
219 }
220
221
222 static void
223 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
224 {
225 struct wpa_supplicant *wpa_s = eloop_ctx;
226
227 wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
228
229 if (wpa_supplicant_req_sched_scan(wpa_s))
230 wpa_supplicant_req_scan(wpa_s, 0, 0);
231 }
232
233
234 static void
235 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
236 {
237 struct wpa_supplicant *wpa_s = eloop_ctx;
238
239 wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
240
241 wpa_s->sched_scan_timed_out = 1;
242 wpa_supplicant_cancel_sched_scan(wpa_s);
243 }
244
245
246 static int
247 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
248 struct wpa_driver_scan_params *params,
249 int interval)
250 {
251 int ret;
252
253 wpa_supplicant_notify_scanning(wpa_s, 1);
254 ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
255 if (ret)
256 wpa_supplicant_notify_scanning(wpa_s, 0);
257 else
258 wpa_s->sched_scanning = 1;
259
260 return ret;
261 }
262
263
264 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
265 {
266 int ret;
267
268 ret = wpa_drv_stop_sched_scan(wpa_s);
269 if (ret) {
270 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
271 /* TODO: what to do if stopping fails? */
272 return -1;
273 }
274
275 return ret;
276 }
277
278
279 static struct wpa_driver_scan_filter *
280 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
281 {
282 struct wpa_driver_scan_filter *ssids;
283 struct wpa_ssid *ssid;
284 size_t count;
285
286 *num_ssids = 0;
287 if (!conf->filter_ssids)
288 return NULL;
289
290 for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
291 if (ssid->ssid && ssid->ssid_len)
292 count++;
293 }
294 if (count == 0)
295 return NULL;
296 ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
297 if (ssids == NULL)
298 return NULL;
299
300 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
301 if (!ssid->ssid || !ssid->ssid_len)
302 continue;
303 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
304 ssids[*num_ssids].ssid_len = ssid->ssid_len;
305 (*num_ssids)++;
306 }
307
308 return ssids;
309 }
310
311
312 static void wpa_supplicant_optimize_freqs(
313 struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
314 {
315 #ifdef CONFIG_P2P
316 if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
317 wpa_s->go_params) {
318 /* Optimize provisioning state scan based on GO information */
319 if (wpa_s->p2p_in_provisioning < 5 &&
320 wpa_s->go_params->freq > 0) {
321 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
322 "preferred frequency %d MHz",
323 wpa_s->go_params->freq);
324 params->freqs = os_zalloc(2 * sizeof(int));
325 if (params->freqs)
326 params->freqs[0] = wpa_s->go_params->freq;
327 } else if (wpa_s->p2p_in_provisioning < 8 &&
328 wpa_s->go_params->freq_list[0]) {
329 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
330 "channels");
331 int_array_concat(&params->freqs,
332 wpa_s->go_params->freq_list);
333 if (params->freqs)
334 int_array_sort_unique(params->freqs);
335 }
336 wpa_s->p2p_in_provisioning++;
337 }
338 #endif /* CONFIG_P2P */
339
340 #ifdef CONFIG_WPS
341 if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
342 /*
343 * Optimize post-provisioning scan based on channel used
344 * during provisioning.
345 */
346 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
347 "that was used during provisioning", wpa_s->wps_freq);
348 params->freqs = os_zalloc(2 * sizeof(int));
349 if (params->freqs)
350 params->freqs[0] = wpa_s->wps_freq;
351 wpa_s->after_wps--;
352 }
353
354 if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
355 {
356 /* Optimize provisioning scan based on already known channel */
357 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
358 wpa_s->wps_freq);
359 params->freqs = os_zalloc(2 * sizeof(int));
360 if (params->freqs)
361 params->freqs[0] = wpa_s->wps_freq;
362 wpa_s->known_wps_freq = 0; /* only do this once */
363 }
364 #endif /* CONFIG_WPS */
365 }
366
367
368 #ifdef CONFIG_INTERWORKING
369 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
370 struct wpabuf *buf)
371 {
372 if (wpa_s->conf->interworking == 0)
373 return;
374
375 wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
376 wpabuf_put_u8(buf, 4);
377 wpabuf_put_u8(buf, 0x00);
378 wpabuf_put_u8(buf, 0x00);
379 wpabuf_put_u8(buf, 0x00);
380 wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
381
382 wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
383 wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
384 1 + ETH_ALEN);
385 wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
386 /* No Venue Info */
387 if (!is_zero_ether_addr(wpa_s->conf->hessid))
388 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
389 }
390 #endif /* CONFIG_INTERWORKING */
391
392
393 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
394 {
395 struct wpabuf *extra_ie = NULL;
396 #ifdef CONFIG_WPS
397 int wps = 0;
398 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
399 #endif /* CONFIG_WPS */
400
401 #ifdef CONFIG_INTERWORKING
402 if (wpa_s->conf->interworking &&
403 wpabuf_resize(&extra_ie, 100) == 0)
404 wpas_add_interworking_elements(wpa_s, extra_ie);
405 #endif /* CONFIG_INTERWORKING */
406
407 #ifdef CONFIG_WPS
408 wps = wpas_wps_in_use(wpa_s, &req_type);
409
410 if (wps) {
411 struct wpabuf *wps_ie;
412 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
413 DEV_PW_DEFAULT,
414 &wpa_s->wps->dev,
415 wpa_s->wps->uuid, req_type,
416 0, NULL);
417 if (wps_ie) {
418 if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
419 wpabuf_put_buf(extra_ie, wps_ie);
420 wpabuf_free(wps_ie);
421 }
422 }
423
424 #ifdef CONFIG_P2P
425 if (wps) {
426 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
427 if (wpabuf_resize(&extra_ie, ielen) == 0)
428 wpas_p2p_scan_ie(wpa_s, extra_ie);
429 }
430 #endif /* CONFIG_P2P */
431
432 #endif /* CONFIG_WPS */
433
434 return extra_ie;
435 }
436
437
438 #ifdef CONFIG_P2P
439
440 /*
441 * Check whether there are any enabled networks or credentials that could be
442 * used for a non-P2P connection.
443 */
444 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
445 {
446 struct wpa_ssid *ssid;
447
448 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
449 if (wpas_network_disabled(wpa_s, ssid))
450 continue;
451 if (!ssid->p2p_group)
452 return 1;
453 }
454
455 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
456 wpa_s->conf->auto_interworking)
457 return 1;
458
459 return 0;
460 }
461
462
463 /*
464 * Find the operating frequency of any other virtual interface that is using
465 * the same radio concurrently.
466 */
467 static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s)
468 {
469 const char *rn, *rn2;
470 struct wpa_supplicant *ifs;
471 u8 bssid[ETH_ALEN];
472
473 if (!wpa_s->driver->get_radio_name)
474 return -1;
475
476 rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv);
477 if (rn == NULL || rn[0] == '\0')
478 return -1;
479
480 for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) {
481 if (ifs == wpa_s || !ifs->driver->get_radio_name)
482 continue;
483
484 rn2 = ifs->driver->get_radio_name(ifs->drv_priv);
485 if (!rn2 || os_strcmp(rn, rn2) != 0)
486 continue;
487
488 if (ifs->current_ssid == NULL || ifs->assoc_freq == 0)
489 continue;
490
491 if (ifs->current_ssid->mode == WPAS_MODE_AP ||
492 ifs->current_ssid->mode == WPAS_MODE_P2P_GO)
493 return ifs->current_ssid->frequency;
494 if (wpa_drv_get_bssid(ifs, bssid) == 0)
495 return ifs->assoc_freq;
496 }
497
498 return 0;
499 }
500
501 #endif /* CONFIG_P2P */
502
503
504 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
505 {
506 struct wpa_supplicant *wpa_s = eloop_ctx;
507 struct wpa_ssid *ssid;
508 int scan_req = 0, ret;
509 struct wpabuf *extra_ie = NULL;
510 struct wpa_driver_scan_params params;
511 struct wpa_driver_scan_params *scan_params;
512 size_t max_ssids;
513 enum wpa_states prev_state;
514
515 if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
516 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
517 return;
518 }
519
520 if (wpa_s->disconnected && !wpa_s->scan_req) {
521 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
522 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
523 return;
524 }
525
526 if (!wpa_supplicant_enabled_networks(wpa_s) &&
527 !wpa_s->scan_req) {
528 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
529 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
530 #ifdef CONFIG_P2P
531 wpa_s->sta_scan_pending = 0;
532 #endif /* CONFIG_P2P */
533 return;
534 }
535
536 if (wpa_s->conf->ap_scan != 0 &&
537 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
538 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
539 "overriding ap_scan configuration");
540 wpa_s->conf->ap_scan = 0;
541 wpas_notify_ap_scan_changed(wpa_s);
542 }
543
544 if (wpa_s->conf->ap_scan == 0) {
545 wpa_supplicant_gen_assoc_event(wpa_s);
546 return;
547 }
548
549 #ifdef CONFIG_P2P
550 if (wpas_p2p_in_progress(wpa_s)) {
551 if (wpa_s->sta_scan_pending &&
552 wpas_p2p_in_progress(wpa_s) == 2 &&
553 wpa_s->global->p2p_cb_on_scan_complete) {
554 wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
555 "mode scan during P2P search");
556 } else {
557 wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
558 "while P2P operation is in progress");
559 wpa_s->sta_scan_pending = 1;
560 wpa_supplicant_req_scan(wpa_s, 5, 0);
561 return;
562 }
563 }
564 #endif /* CONFIG_P2P */
565
566 if (wpa_s->conf->ap_scan == 2)
567 max_ssids = 1;
568 else {
569 max_ssids = wpa_s->max_scan_ssids;
570 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
571 max_ssids = WPAS_MAX_SCAN_SSIDS;
572 }
573
574 scan_req = wpa_s->scan_req;
575 wpa_s->scan_req = 0;
576
577 os_memset(&params, 0, sizeof(params));
578
579 prev_state = wpa_s->wpa_state;
580 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
581 wpa_s->wpa_state == WPA_INACTIVE)
582 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
583
584 /*
585 * If autoscan has set its own scanning parameters
586 */
587 if (wpa_s->autoscan_params != NULL) {
588 scan_params = wpa_s->autoscan_params;
589 goto scan;
590 }
591
592 if (scan_req != 2 && wpa_s->connect_without_scan) {
593 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
594 if (ssid == wpa_s->connect_without_scan)
595 break;
596 }
597 wpa_s->connect_without_scan = NULL;
598 if (ssid) {
599 wpa_printf(MSG_DEBUG, "Start a pre-selected network "
600 "without scan step");
601 wpa_supplicant_associate(wpa_s, NULL, ssid);
602 return;
603 }
604 }
605
606 #ifdef CONFIG_P2P
607 if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
608 wpa_s->go_params) {
609 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
610 "P2P group formation");
611 params.ssids[0].ssid = wpa_s->go_params->ssid;
612 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
613 params.num_ssids = 1;
614 goto ssid_list_set;
615 }
616 #endif /* CONFIG_P2P */
617
618 /* Find the starting point from which to continue scanning */
619 ssid = wpa_s->conf->ssid;
620 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
621 while (ssid) {
622 if (ssid == wpa_s->prev_scan_ssid) {
623 ssid = ssid->next;
624 break;
625 }
626 ssid = ssid->next;
627 }
628 }
629
630 if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
631 wpa_s->connect_without_scan = NULL;
632 wpa_s->prev_scan_wildcard = 0;
633 wpa_supplicant_assoc_try(wpa_s, ssid);
634 return;
635 } else if (wpa_s->conf->ap_scan == 2) {
636 /*
637 * User-initiated scan request in ap_scan == 2; scan with
638 * wildcard SSID.
639 */
640 ssid = NULL;
641 } else {
642 struct wpa_ssid *start = ssid, *tssid;
643 int freqs_set = 0;
644 if (ssid == NULL && max_ssids > 1)
645 ssid = wpa_s->conf->ssid;
646 while (ssid) {
647 if (!wpas_network_disabled(wpa_s, ssid) &&
648 ssid->scan_ssid) {
649 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
650 ssid->ssid, ssid->ssid_len);
651 params.ssids[params.num_ssids].ssid =
652 ssid->ssid;
653 params.ssids[params.num_ssids].ssid_len =
654 ssid->ssid_len;
655 params.num_ssids++;
656 if (params.num_ssids + 1 >= max_ssids)
657 break;
658 }
659 ssid = ssid->next;
660 if (ssid == start)
661 break;
662 if (ssid == NULL && max_ssids > 1 &&
663 start != wpa_s->conf->ssid)
664 ssid = wpa_s->conf->ssid;
665 }
666
667 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
668 if (wpas_network_disabled(wpa_s, tssid))
669 continue;
670 if ((params.freqs || !freqs_set) && tssid->scan_freq) {
671 int_array_concat(&params.freqs,
672 tssid->scan_freq);
673 } else {
674 os_free(params.freqs);
675 params.freqs = NULL;
676 }
677 freqs_set = 1;
678 }
679 int_array_sort_unique(params.freqs);
680 }
681
682 if (ssid && max_ssids == 1) {
683 /*
684 * If the driver is limited to 1 SSID at a time interleave
685 * wildcard SSID scans with specific SSID scans to avoid
686 * waiting a long time for a wildcard scan.
687 */
688 if (!wpa_s->prev_scan_wildcard) {
689 params.ssids[0].ssid = NULL;
690 params.ssids[0].ssid_len = 0;
691 wpa_s->prev_scan_wildcard = 1;
692 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
693 "wildcard SSID (Interleave with specific)");
694 } else {
695 wpa_s->prev_scan_ssid = ssid;
696 wpa_s->prev_scan_wildcard = 0;
697 wpa_dbg(wpa_s, MSG_DEBUG,
698 "Starting AP scan for specific SSID: %s",
699 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
700 }
701 } else if (ssid) {
702 /* max_ssids > 1 */
703
704 wpa_s->prev_scan_ssid = ssid;
705 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
706 "the scan request");
707 params.num_ssids++;
708 } else {
709 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
710 params.num_ssids++;
711 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
712 "SSID");
713 }
714 #ifdef CONFIG_P2P
715 ssid_list_set:
716 #endif /* CONFIG_P2P */
717
718 wpa_supplicant_optimize_freqs(wpa_s, &params);
719 extra_ie = wpa_supplicant_extra_ies(wpa_s);
720
721 #ifdef CONFIG_HS20
722 if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
723 wpas_hs20_add_indication(extra_ie);
724 #endif /* CONFIG_HS20 */
725
726 if (params.freqs == NULL && wpa_s->next_scan_freqs) {
727 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
728 "generated frequency list");
729 params.freqs = wpa_s->next_scan_freqs;
730 } else
731 os_free(wpa_s->next_scan_freqs);
732 wpa_s->next_scan_freqs = NULL;
733
734 params.filter_ssids = wpa_supplicant_build_filter_ssids(
735 wpa_s->conf, &params.num_filter_ssids);
736 if (extra_ie) {
737 params.extra_ies = wpabuf_head(extra_ie);
738 params.extra_ies_len = wpabuf_len(extra_ie);
739 }
740
741 #ifdef CONFIG_P2P
742 if (wpa_s->p2p_in_provisioning ||
743 (wpa_s->show_group_started && wpa_s->go_params)) {
744 /*
745 * The interface may not yet be in P2P mode, so we have to
746 * explicitly request P2P probe to disable CCK rates.
747 */
748 params.p2p_probe = 1;
749 }
750 #endif /* CONFIG_P2P */
751
752 scan_params = &params;
753
754 scan:
755 #ifdef CONFIG_P2P
756 /*
757 * If the driver does not support multi-channel concurrency and a
758 * virtual interface that shares the same radio with the wpa_s interface
759 * is operating there may not be need to scan other channels apart from
760 * the current operating channel on the other virtual interface. Filter
761 * out other channels in case we are trying to find a connection for a
762 * station interface when we are not configured to prefer station
763 * connection and a concurrent operation is already in process.
764 */
765 if (wpa_s->scan_for_connection && !scan_req &&
766 !scan_params->freqs && !params.freqs &&
767 wpas_is_p2p_prioritized(wpa_s) &&
768 !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) &&
769 wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
770 non_p2p_network_enabled(wpa_s)) {
771 int freq = shared_vif_oper_freq(wpa_s);
772 if (freq > 0) {
773 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current "
774 "operating channel (%d MHz) since driver does "
775 "not support multi-channel concurrency", freq);
776 params.freqs = os_zalloc(sizeof(int) * 2);
777 if (params.freqs)
778 params.freqs[0] = freq;
779 scan_params->freqs = params.freqs;
780 }
781 }
782 #endif /* CONFIG_P2P */
783
784 ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
785
786 wpabuf_free(extra_ie);
787 os_free(params.freqs);
788 os_free(params.filter_ssids);
789
790 if (ret) {
791 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
792 if (prev_state != wpa_s->wpa_state)
793 wpa_supplicant_set_state(wpa_s, prev_state);
794 /* Restore scan_req since we will try to scan again */
795 wpa_s->scan_req = scan_req;
796 wpa_supplicant_req_scan(wpa_s, 1, 0);
797 } else {
798 wpa_s->scan_for_connection = 0;
799 }
800 }
801
802
803 /**
804 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
805 * @wpa_s: Pointer to wpa_supplicant data
806 * @sec: Number of seconds after which to scan
807 * @usec: Number of microseconds after which to scan
808 *
809 * This function is used to schedule a scan for neighboring access points after
810 * the specified time.
811 */
812 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
813 {
814 /* If there's at least one network that should be specifically scanned
815 * then don't cancel the scan and reschedule. Some drivers do
816 * background scanning which generates frequent scan results, and that
817 * causes the specific SSID scan to get continually pushed back and
818 * never happen, which causes hidden APs to never get probe-scanned.
819 */
820 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
821 wpa_s->conf->ap_scan == 1) {
822 struct wpa_ssid *ssid = wpa_s->conf->ssid;
823
824 while (ssid) {
825 if (!wpas_network_disabled(wpa_s, ssid) &&
826 ssid->scan_ssid)
827 break;
828 ssid = ssid->next;
829 }
830 if (ssid) {
831 wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
832 "ensure that specific SSID scans occur");
833 return;
834 }
835 }
836
837 wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
838 sec, usec);
839 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
840 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
841 }
842
843
844 /**
845 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
846 * @wpa_s: Pointer to wpa_supplicant data
847 * @sec: Number of seconds after which to scan
848 * @usec: Number of microseconds after which to scan
849 *
850 * This function is used to schedule periodic scans for neighboring
851 * access points after the specified time.
852 */
853 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
854 int sec, int usec)
855 {
856 if (!wpa_s->sched_scan_supported)
857 return -1;
858
859 eloop_register_timeout(sec, usec,
860 wpa_supplicant_delayed_sched_scan_timeout,
861 wpa_s, NULL);
862
863 return 0;
864 }
865
866
867 /**
868 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
869 * @wpa_s: Pointer to wpa_supplicant data
870 *
871 * This function is used to schedule periodic scans for neighboring
872 * access points repeating the scan continuously.
873 */
874 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
875 {
876 struct wpa_driver_scan_params params;
877 struct wpa_driver_scan_params *scan_params;
878 enum wpa_states prev_state;
879 struct wpa_ssid *ssid = NULL;
880 struct wpabuf *extra_ie = NULL;
881 int ret;
882 unsigned int max_sched_scan_ssids;
883 int wildcard = 0;
884 int need_ssids;
885
886 if (!wpa_s->sched_scan_supported)
887 return -1;
888
889 if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
890 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
891 else
892 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
893 if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
894 return -1;
895
896 if (wpa_s->sched_scanning) {
897 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
898 return 0;
899 }
900
901 need_ssids = 0;
902 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
903 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
904 /* Use wildcard SSID to find this network */
905 wildcard = 1;
906 } else if (!wpas_network_disabled(wpa_s, ssid) &&
907 ssid->ssid_len)
908 need_ssids++;
909
910 #ifdef CONFIG_WPS
911 if (!wpas_network_disabled(wpa_s, ssid) &&
912 ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
913 /*
914 * Normal scan is more reliable and faster for WPS
915 * operations and since these are for short periods of
916 * time, the benefit of trying to use sched_scan would
917 * be limited.
918 */
919 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
920 "sched_scan for WPS");
921 return -1;
922 }
923 #endif /* CONFIG_WPS */
924 }
925 if (wildcard)
926 need_ssids++;
927
928 if (wpa_s->normal_scans < 3 &&
929 (need_ssids <= wpa_s->max_scan_ssids ||
930 wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
931 /*
932 * When normal scan can speed up operations, use that for the
933 * first operations before starting the sched_scan to allow
934 * user space sleep more. We do this only if the normal scan
935 * has functionality that is suitable for this or if the
936 * sched_scan does not have better support for multiple SSIDs.
937 */
938 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
939 "sched_scan for initial scans (normal_scans=%d)",
940 wpa_s->normal_scans);
941 return -1;
942 }
943
944 os_memset(&params, 0, sizeof(params));
945
946 /* If we can't allocate space for the filters, we just don't filter */
947 params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
948 sizeof(struct wpa_driver_scan_filter));
949
950 prev_state = wpa_s->wpa_state;
951 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
952 wpa_s->wpa_state == WPA_INACTIVE)
953 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
954
955 if (wpa_s->autoscan_params != NULL) {
956 scan_params = wpa_s->autoscan_params;
957 goto scan;
958 }
959
960 /* Find the starting point from which to continue scanning */
961 ssid = wpa_s->conf->ssid;
962 if (wpa_s->prev_sched_ssid) {
963 while (ssid) {
964 if (ssid == wpa_s->prev_sched_ssid) {
965 ssid = ssid->next;
966 break;
967 }
968 ssid = ssid->next;
969 }
970 }
971
972 if (!ssid || !wpa_s->prev_sched_ssid) {
973 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
974
975 if (wpa_s->sched_scan_interval == 0)
976 wpa_s->sched_scan_interval = 10;
977 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
978 wpa_s->first_sched_scan = 1;
979 ssid = wpa_s->conf->ssid;
980 wpa_s->prev_sched_ssid = ssid;
981 }
982
983 if (wildcard) {
984 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
985 params.num_ssids++;
986 }
987
988 while (ssid) {
989 if (wpas_network_disabled(wpa_s, ssid))
990 goto next;
991
992 if (params.num_filter_ssids < wpa_s->max_match_sets &&
993 params.filter_ssids && ssid->ssid && ssid->ssid_len) {
994 wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
995 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
996 os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
997 ssid->ssid, ssid->ssid_len);
998 params.filter_ssids[params.num_filter_ssids].ssid_len =
999 ssid->ssid_len;
1000 params.num_filter_ssids++;
1001 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1002 {
1003 wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1004 "filter for sched_scan - drop filter");
1005 os_free(params.filter_ssids);
1006 params.filter_ssids = NULL;
1007 params.num_filter_ssids = 0;
1008 }
1009
1010 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1011 if (params.num_ssids == max_sched_scan_ssids)
1012 break; /* only room for broadcast SSID */
1013 wpa_dbg(wpa_s, MSG_DEBUG,
1014 "add to active scan ssid: %s",
1015 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1016 params.ssids[params.num_ssids].ssid =
1017 ssid->ssid;
1018 params.ssids[params.num_ssids].ssid_len =
1019 ssid->ssid_len;
1020 params.num_ssids++;
1021 if (params.num_ssids >= max_sched_scan_ssids) {
1022 wpa_s->prev_sched_ssid = ssid;
1023 do {
1024 ssid = ssid->next;
1025 } while (ssid &&
1026 (wpas_network_disabled(wpa_s, ssid) ||
1027 !ssid->scan_ssid));
1028 break;
1029 }
1030 }
1031
1032 next:
1033 wpa_s->prev_sched_ssid = ssid;
1034 ssid = ssid->next;
1035 }
1036
1037 if (params.num_filter_ssids == 0) {
1038 os_free(params.filter_ssids);
1039 params.filter_ssids = NULL;
1040 }
1041
1042 extra_ie = wpa_supplicant_extra_ies(wpa_s);
1043 if (extra_ie) {
1044 params.extra_ies = wpabuf_head(extra_ie);
1045 params.extra_ies_len = wpabuf_len(extra_ie);
1046 }
1047
1048 scan_params = &params;
1049
1050 scan:
1051 if (ssid || !wpa_s->first_sched_scan) {
1052 wpa_dbg(wpa_s, MSG_DEBUG,
1053 "Starting sched scan: interval %d timeout %d",
1054 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1055 } else {
1056 wpa_dbg(wpa_s, MSG_DEBUG,
1057 "Starting sched scan: interval %d (no timeout)",
1058 wpa_s->sched_scan_interval);
1059 }
1060
1061 ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1062 wpa_s->sched_scan_interval);
1063 wpabuf_free(extra_ie);
1064 os_free(params.filter_ssids);
1065 if (ret) {
1066 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1067 if (prev_state != wpa_s->wpa_state)
1068 wpa_supplicant_set_state(wpa_s, prev_state);
1069 return ret;
1070 }
1071
1072 /* If we have more SSIDs to scan, add a timeout so we scan them too */
1073 if (ssid || !wpa_s->first_sched_scan) {
1074 wpa_s->sched_scan_timed_out = 0;
1075 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1076 wpa_supplicant_sched_scan_timeout,
1077 wpa_s, NULL);
1078 wpa_s->first_sched_scan = 0;
1079 wpa_s->sched_scan_timeout /= 2;
1080 wpa_s->sched_scan_interval *= 2;
1081 }
1082
1083 return 0;
1084 }
1085
1086
1087 /**
1088 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1089 * @wpa_s: Pointer to wpa_supplicant data
1090 *
1091 * This function is used to cancel a scan request scheduled with
1092 * wpa_supplicant_req_scan().
1093 */
1094 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1095 {
1096 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1097 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1098 }
1099
1100
1101 /**
1102 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1103 * @wpa_s: Pointer to wpa_supplicant data
1104 *
1105 * This function is used to stop a periodic scheduled scan.
1106 */
1107 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1108 {
1109 if (!wpa_s->sched_scanning)
1110 return;
1111
1112 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1113 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1114 wpa_supplicant_stop_sched_scan(wpa_s);
1115 }
1116
1117
1118 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1119 int scanning)
1120 {
1121 if (wpa_s->scanning != scanning) {
1122 wpa_s->scanning = scanning;
1123 wpas_notify_scanning(wpa_s);
1124 }
1125 }
1126
1127
1128 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1129 {
1130 int rate = 0;
1131 const u8 *ie;
1132 int i;
1133
1134 ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1135 for (i = 0; ie && i < ie[1]; i++) {
1136 if ((ie[i + 2] & 0x7f) > rate)
1137 rate = ie[i + 2] & 0x7f;
1138 }
1139
1140 ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1141 for (i = 0; ie && i < ie[1]; i++) {
1142 if ((ie[i + 2] & 0x7f) > rate)
1143 rate = ie[i + 2] & 0x7f;
1144 }
1145
1146 return rate;
1147 }
1148
1149
1150 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1151 {
1152 const u8 *end, *pos;
1153
1154 pos = (const u8 *) (res + 1);
1155 end = pos + res->ie_len;
1156
1157 while (pos + 1 < end) {
1158 if (pos + 2 + pos[1] > end)
1159 break;
1160 if (pos[0] == ie)
1161 return pos;
1162 pos += 2 + pos[1];
1163 }
1164
1165 return NULL;
1166 }
1167
1168
1169 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1170 u32 vendor_type)
1171 {
1172 const u8 *end, *pos;
1173
1174 pos = (const u8 *) (res + 1);
1175 end = pos + res->ie_len;
1176
1177 while (pos + 1 < end) {
1178 if (pos + 2 + pos[1] > end)
1179 break;
1180 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1181 vendor_type == WPA_GET_BE32(&pos[2]))
1182 return pos;
1183 pos += 2 + pos[1];
1184 }
1185
1186 return NULL;
1187 }
1188
1189
1190 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1191 u32 vendor_type)
1192 {
1193 struct wpabuf *buf;
1194 const u8 *end, *pos;
1195
1196 buf = wpabuf_alloc(res->ie_len);
1197 if (buf == NULL)
1198 return NULL;
1199
1200 pos = (const u8 *) (res + 1);
1201 end = pos + res->ie_len;
1202
1203 while (pos + 1 < end) {
1204 if (pos + 2 + pos[1] > end)
1205 break;
1206 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1207 vendor_type == WPA_GET_BE32(&pos[2]))
1208 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1209 pos += 2 + pos[1];
1210 }
1211
1212 if (wpabuf_len(buf) == 0) {
1213 wpabuf_free(buf);
1214 buf = NULL;
1215 }
1216
1217 return buf;
1218 }
1219
1220
1221 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1222 const struct wpa_scan_res *res, u32 vendor_type)
1223 {
1224 struct wpabuf *buf;
1225 const u8 *end, *pos;
1226
1227 if (res->beacon_ie_len == 0)
1228 return NULL;
1229 buf = wpabuf_alloc(res->beacon_ie_len);
1230 if (buf == NULL)
1231 return NULL;
1232
1233 pos = (const u8 *) (res + 1);
1234 pos += res->ie_len;
1235 end = pos + res->beacon_ie_len;
1236
1237 while (pos + 1 < end) {
1238 if (pos + 2 + pos[1] > end)
1239 break;
1240 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1241 vendor_type == WPA_GET_BE32(&pos[2]))
1242 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1243 pos += 2 + pos[1];
1244 }
1245
1246 if (wpabuf_len(buf) == 0) {
1247 wpabuf_free(buf);
1248 buf = NULL;
1249 }
1250
1251 return buf;
1252 }
1253
1254
1255 /*
1256 * Channels with a great SNR can operate at full rate. What is a great SNR?
1257 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1258 * rule of thumb is that any SNR above 20 is good." This one
1259 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1260 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1261 * conservative value.
1262 */
1263 #define GREAT_SNR 30
1264
1265 /* Compare function for sorting scan results. Return >0 if @b is considered
1266 * better. */
1267 static int wpa_scan_result_compar(const void *a, const void *b)
1268 {
1269 #define IS_5GHZ(n) (n > 4000)
1270 #define MIN(a,b) a < b ? a : b
1271 struct wpa_scan_res **_wa = (void *) a;
1272 struct wpa_scan_res **_wb = (void *) b;
1273 struct wpa_scan_res *wa = *_wa;
1274 struct wpa_scan_res *wb = *_wb;
1275 int wpa_a, wpa_b, maxrate_a, maxrate_b;
1276 int snr_a, snr_b;
1277
1278 /* WPA/WPA2 support preferred */
1279 wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1280 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1281 wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1282 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1283
1284 if (wpa_b && !wpa_a)
1285 return 1;
1286 if (!wpa_b && wpa_a)
1287 return -1;
1288
1289 /* privacy support preferred */
1290 if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1291 (wb->caps & IEEE80211_CAP_PRIVACY))
1292 return 1;
1293 if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1294 (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1295 return -1;
1296
1297 if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1298 !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1299 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1300 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1301 } else {
1302 /* Not suitable information to calculate SNR, so use level */
1303 snr_a = wa->level;
1304 snr_b = wb->level;
1305 }
1306
1307 /* best/max rate preferred if SNR close enough */
1308 if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1309 (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1310 maxrate_a = wpa_scan_get_max_rate(wa);
1311 maxrate_b = wpa_scan_get_max_rate(wb);
1312 if (maxrate_a != maxrate_b)
1313 return maxrate_b - maxrate_a;
1314 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1315 return IS_5GHZ(wa->freq) ? -1 : 1;
1316 }
1317
1318 /* use freq for channel preference */
1319
1320 /* all things being equal, use SNR; if SNRs are
1321 * identical, use quality values since some drivers may only report
1322 * that value and leave the signal level zero */
1323 if (snr_b == snr_a)
1324 return wb->qual - wa->qual;
1325 return snr_b - snr_a;
1326 #undef MIN
1327 #undef IS_5GHZ
1328 }
1329
1330
1331 #ifdef CONFIG_WPS
1332 /* Compare function for sorting scan results when searching a WPS AP for
1333 * provisioning. Return >0 if @b is considered better. */
1334 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1335 {
1336 struct wpa_scan_res **_wa = (void *) a;
1337 struct wpa_scan_res **_wb = (void *) b;
1338 struct wpa_scan_res *wa = *_wa;
1339 struct wpa_scan_res *wb = *_wb;
1340 int uses_wps_a, uses_wps_b;
1341 struct wpabuf *wps_a, *wps_b;
1342 int res;
1343
1344 /* Optimization - check WPS IE existence before allocated memory and
1345 * doing full reassembly. */
1346 uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1347 uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1348 if (uses_wps_a && !uses_wps_b)
1349 return -1;
1350 if (!uses_wps_a && uses_wps_b)
1351 return 1;
1352
1353 if (uses_wps_a && uses_wps_b) {
1354 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1355 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1356 res = wps_ap_priority_compar(wps_a, wps_b);
1357 wpabuf_free(wps_a);
1358 wpabuf_free(wps_b);
1359 if (res)
1360 return res;
1361 }
1362
1363 /*
1364 * Do not use current AP security policy as a sorting criteria during
1365 * WPS provisioning step since the AP may get reconfigured at the
1366 * completion of provisioning.
1367 */
1368
1369 /* all things being equal, use signal level; if signal levels are
1370 * identical, use quality values since some drivers may only report
1371 * that value and leave the signal level zero */
1372 if (wb->level == wa->level)
1373 return wb->qual - wa->qual;
1374 return wb->level - wa->level;
1375 }
1376 #endif /* CONFIG_WPS */
1377
1378
1379 static void dump_scan_res(struct wpa_scan_results *scan_res)
1380 {
1381 #ifndef CONFIG_NO_STDOUT_DEBUG
1382 size_t i;
1383
1384 if (scan_res->res == NULL || scan_res->num == 0)
1385 return;
1386
1387 wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1388
1389 for (i = 0; i < scan_res->num; i++) {
1390 struct wpa_scan_res *r = scan_res->res[i];
1391 u8 *pos;
1392 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1393 == WPA_SCAN_LEVEL_DBM) {
1394 int snr = r->level - r->noise;
1395 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1396 "noise=%d level=%d snr=%d%s flags=0x%x",
1397 MAC2STR(r->bssid), r->freq, r->qual,
1398 r->noise, r->level, snr,
1399 snr >= GREAT_SNR ? "*" : "", r->flags);
1400 } else {
1401 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1402 "noise=%d level=%d flags=0x%x",
1403 MAC2STR(r->bssid), r->freq, r->qual,
1404 r->noise, r->level, r->flags);
1405 }
1406 pos = (u8 *) (r + 1);
1407 if (r->ie_len)
1408 wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1409 pos += r->ie_len;
1410 if (r->beacon_ie_len)
1411 wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1412 pos, r->beacon_ie_len);
1413 }
1414 #endif /* CONFIG_NO_STDOUT_DEBUG */
1415 }
1416
1417
1418 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1419 const u8 *bssid)
1420 {
1421 size_t i;
1422
1423 if (wpa_s->bssid_filter == NULL)
1424 return 1;
1425
1426 for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1427 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1428 ETH_ALEN) == 0)
1429 return 1;
1430 }
1431
1432 return 0;
1433 }
1434
1435
1436 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1437 struct wpa_scan_results *res)
1438 {
1439 size_t i, j;
1440
1441 if (wpa_s->bssid_filter == NULL)
1442 return;
1443
1444 for (i = 0, j = 0; i < res->num; i++) {
1445 if (wpa_supplicant_filter_bssid_match(wpa_s,
1446 res->res[i]->bssid)) {
1447 res->res[j++] = res->res[i];
1448 } else {
1449 os_free(res->res[i]);
1450 res->res[i] = NULL;
1451 }
1452 }
1453
1454 if (res->num != j) {
1455 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1456 (int) (res->num - j));
1457 res->num = j;
1458 }
1459 }
1460
1461
1462 /**
1463 * wpa_supplicant_get_scan_results - Get scan results
1464 * @wpa_s: Pointer to wpa_supplicant data
1465 * @info: Information about what was scanned or %NULL if not available
1466 * @new_scan: Whether a new scan was performed
1467 * Returns: Scan results, %NULL on failure
1468 *
1469 * This function request the current scan results from the driver and updates
1470 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1471 * results with wpa_scan_results_free().
1472 */
1473 struct wpa_scan_results *
1474 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1475 struct scan_info *info, int new_scan)
1476 {
1477 struct wpa_scan_results *scan_res;
1478 size_t i;
1479 int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1480
1481 scan_res = wpa_drv_get_scan_results2(wpa_s);
1482 if (scan_res == NULL) {
1483 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1484 return NULL;
1485 }
1486 filter_scan_res(wpa_s, scan_res);
1487
1488 #ifdef CONFIG_WPS
1489 if (wpas_wps_in_progress(wpa_s)) {
1490 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1491 "provisioning rules");
1492 compar = wpa_scan_result_wps_compar;
1493 }
1494 #endif /* CONFIG_WPS */
1495
1496 qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1497 compar);
1498 dump_scan_res(scan_res);
1499
1500 wpa_bss_update_start(wpa_s);
1501 for (i = 0; i < scan_res->num; i++)
1502 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1503 wpa_bss_update_end(wpa_s, info, new_scan);
1504
1505 return scan_res;
1506 }
1507
1508
1509 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1510 {
1511 struct wpa_scan_results *scan_res;
1512 scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1513 if (scan_res == NULL)
1514 return -1;
1515 wpa_scan_results_free(scan_res);
1516
1517 return 0;
1518 }
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