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[thirdparty/hostap.git] / wpa_supplicant / scan.c
1 /*
2 * WPA Supplicant - Scanning
3 * Copyright (c) 2003-2012, 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 /**
85 * wpa_supplicant_enabled_networks - Check whether there are enabled networks
86 * @wpa_s: Pointer to wpa_supplicant data
87 * Returns: 0 if no networks are enabled, >0 if networks are enabled
88 *
89 * This function is used to figure out whether any networks (or Interworking
90 * with enabled credentials and auto_interworking) are present in the current
91 * configuration.
92 */
93 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
94 {
95 struct wpa_ssid *ssid = wpa_s->conf->ssid;
96 int count = 0, disabled = 0;
97 while (ssid) {
98 if (!wpas_network_disabled(wpa_s, ssid))
99 count++;
100 else
101 disabled++;
102 ssid = ssid->next;
103 }
104 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
105 wpa_s->conf->auto_interworking)
106 count++;
107 if (count == 0 && disabled > 0) {
108 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled "
109 "networks)", disabled);
110 }
111 return count;
112 }
113
114
115 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
116 struct wpa_ssid *ssid)
117 {
118 while (ssid) {
119 if (!wpas_network_disabled(wpa_s, ssid))
120 break;
121 ssid = ssid->next;
122 }
123
124 /* ap_scan=2 mode - try to associate with each SSID. */
125 if (ssid == NULL) {
126 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
127 "end of scan list - go back to beginning");
128 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
129 wpa_supplicant_req_scan(wpa_s, 0, 0);
130 return;
131 }
132 if (ssid->next) {
133 /* Continue from the next SSID on the next attempt. */
134 wpa_s->prev_scan_ssid = ssid;
135 } else {
136 /* Start from the beginning of the SSID list. */
137 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
138 }
139 wpa_supplicant_associate(wpa_s, NULL, ssid);
140 }
141
142
143 static int int_array_len(const int *a)
144 {
145 int i;
146 for (i = 0; a && a[i]; i++)
147 ;
148 return i;
149 }
150
151
152 static void int_array_concat(int **res, const int *a)
153 {
154 int reslen, alen, i;
155 int *n;
156
157 reslen = int_array_len(*res);
158 alen = int_array_len(a);
159
160 n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
161 if (n == NULL) {
162 os_free(*res);
163 *res = NULL;
164 return;
165 }
166 for (i = 0; i <= alen; i++)
167 n[reslen + i] = a[i];
168 *res = n;
169 }
170
171
172 static int freq_cmp(const void *a, const void *b)
173 {
174 int _a = *(int *) a;
175 int _b = *(int *) b;
176
177 if (_a == 0)
178 return 1;
179 if (_b == 0)
180 return -1;
181 return _a - _b;
182 }
183
184
185 static void int_array_sort_unique(int *a)
186 {
187 int alen;
188 int i, j;
189
190 if (a == NULL)
191 return;
192
193 alen = int_array_len(a);
194 qsort(a, alen, sizeof(int), freq_cmp);
195
196 i = 0;
197 j = 1;
198 while (a[i] && a[j]) {
199 if (a[i] == a[j]) {
200 j++;
201 continue;
202 }
203 a[++i] = a[j++];
204 }
205 if (a[i])
206 i++;
207 a[i] = 0;
208 }
209
210
211 /**
212 * wpa_supplicant_trigger_scan - Request driver to start a scan
213 * @wpa_s: Pointer to wpa_supplicant data
214 * @params: Scan parameters
215 * Returns: 0 on success, -1 on failure
216 */
217 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
218 struct wpa_driver_scan_params *params)
219 {
220 int ret;
221
222 wpa_supplicant_notify_scanning(wpa_s, 1);
223
224 ret = wpa_drv_scan(wpa_s, params);
225 if (ret) {
226 wpa_supplicant_notify_scanning(wpa_s, 0);
227 wpas_notify_scan_done(wpa_s, 0);
228 } else {
229 wpa_s->scan_runs++;
230 wpa_s->normal_scans++;
231 }
232
233 return ret;
234 }
235
236
237 static void
238 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
239 {
240 struct wpa_supplicant *wpa_s = eloop_ctx;
241
242 wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
243
244 if (wpa_supplicant_req_sched_scan(wpa_s))
245 wpa_supplicant_req_scan(wpa_s, 0, 0);
246 }
247
248
249 static void
250 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
251 {
252 struct wpa_supplicant *wpa_s = eloop_ctx;
253
254 wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
255
256 wpa_s->sched_scan_timed_out = 1;
257 wpa_supplicant_cancel_sched_scan(wpa_s);
258 }
259
260
261 static int
262 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
263 struct wpa_driver_scan_params *params,
264 int interval)
265 {
266 int ret;
267
268 wpa_supplicant_notify_scanning(wpa_s, 1);
269 ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
270 if (ret)
271 wpa_supplicant_notify_scanning(wpa_s, 0);
272 else
273 wpa_s->sched_scanning = 1;
274
275 return ret;
276 }
277
278
279 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
280 {
281 int ret;
282
283 ret = wpa_drv_stop_sched_scan(wpa_s);
284 if (ret) {
285 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
286 /* TODO: what to do if stopping fails? */
287 return -1;
288 }
289
290 return ret;
291 }
292
293
294 static struct wpa_driver_scan_filter *
295 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
296 {
297 struct wpa_driver_scan_filter *ssids;
298 struct wpa_ssid *ssid;
299 size_t count;
300
301 *num_ssids = 0;
302 if (!conf->filter_ssids)
303 return NULL;
304
305 for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
306 if (ssid->ssid && ssid->ssid_len)
307 count++;
308 }
309 if (count == 0)
310 return NULL;
311 ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
312 if (ssids == NULL)
313 return NULL;
314
315 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
316 if (!ssid->ssid || !ssid->ssid_len)
317 continue;
318 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
319 ssids[*num_ssids].ssid_len = ssid->ssid_len;
320 (*num_ssids)++;
321 }
322
323 return ssids;
324 }
325
326
327 static void wpa_supplicant_optimize_freqs(
328 struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
329 {
330 #ifdef CONFIG_P2P
331 if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
332 wpa_s->go_params) {
333 /* Optimize provisioning state scan based on GO information */
334 if (wpa_s->p2p_in_provisioning < 5 &&
335 wpa_s->go_params->freq > 0) {
336 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
337 "preferred frequency %d MHz",
338 wpa_s->go_params->freq);
339 params->freqs = os_zalloc(2 * sizeof(int));
340 if (params->freqs)
341 params->freqs[0] = wpa_s->go_params->freq;
342 } else if (wpa_s->p2p_in_provisioning < 8 &&
343 wpa_s->go_params->freq_list[0]) {
344 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
345 "channels");
346 int_array_concat(&params->freqs,
347 wpa_s->go_params->freq_list);
348 if (params->freqs)
349 int_array_sort_unique(params->freqs);
350 }
351 wpa_s->p2p_in_provisioning++;
352 }
353 #endif /* CONFIG_P2P */
354
355 #ifdef CONFIG_WPS
356 if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
357 /*
358 * Optimize post-provisioning scan based on channel used
359 * during provisioning.
360 */
361 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
362 "that was used during provisioning", wpa_s->wps_freq);
363 params->freqs = os_zalloc(2 * sizeof(int));
364 if (params->freqs)
365 params->freqs[0] = wpa_s->wps_freq;
366 wpa_s->after_wps--;
367 }
368
369 if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
370 {
371 /* Optimize provisioning scan based on already known channel */
372 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
373 wpa_s->wps_freq);
374 params->freqs = os_zalloc(2 * sizeof(int));
375 if (params->freqs)
376 params->freqs[0] = wpa_s->wps_freq;
377 wpa_s->known_wps_freq = 0; /* only do this once */
378 }
379 #endif /* CONFIG_WPS */
380 }
381
382
383 #ifdef CONFIG_INTERWORKING
384 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
385 struct wpabuf *buf)
386 {
387 if (wpa_s->conf->interworking == 0)
388 return;
389
390 wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
391 wpabuf_put_u8(buf, 4);
392 wpabuf_put_u8(buf, 0x00);
393 wpabuf_put_u8(buf, 0x00);
394 wpabuf_put_u8(buf, 0x00);
395 wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
396
397 wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
398 wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
399 1 + ETH_ALEN);
400 wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
401 /* No Venue Info */
402 if (!is_zero_ether_addr(wpa_s->conf->hessid))
403 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
404 }
405 #endif /* CONFIG_INTERWORKING */
406
407
408 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
409 {
410 struct wpabuf *extra_ie = NULL;
411 #ifdef CONFIG_WPS
412 int wps = 0;
413 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
414 #endif /* CONFIG_WPS */
415
416 #ifdef CONFIG_INTERWORKING
417 if (wpa_s->conf->interworking &&
418 wpabuf_resize(&extra_ie, 100) == 0)
419 wpas_add_interworking_elements(wpa_s, extra_ie);
420 #endif /* CONFIG_INTERWORKING */
421
422 #ifdef CONFIG_WPS
423 wps = wpas_wps_in_use(wpa_s, &req_type);
424
425 if (wps) {
426 struct wpabuf *wps_ie;
427 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
428 DEV_PW_DEFAULT,
429 &wpa_s->wps->dev,
430 wpa_s->wps->uuid, req_type,
431 0, NULL);
432 if (wps_ie) {
433 if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
434 wpabuf_put_buf(extra_ie, wps_ie);
435 wpabuf_free(wps_ie);
436 }
437 }
438
439 #ifdef CONFIG_P2P
440 if (wps) {
441 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
442 if (wpabuf_resize(&extra_ie, ielen) == 0)
443 wpas_p2p_scan_ie(wpa_s, extra_ie);
444 }
445 #endif /* CONFIG_P2P */
446
447 #endif /* CONFIG_WPS */
448
449 return extra_ie;
450 }
451
452
453 #ifdef CONFIG_P2P
454
455 /*
456 * Check whether there are any enabled networks or credentials that could be
457 * used for a non-P2P connection.
458 */
459 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
460 {
461 struct wpa_ssid *ssid;
462
463 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
464 if (wpas_network_disabled(wpa_s, ssid))
465 continue;
466 if (!ssid->p2p_group)
467 return 1;
468 }
469
470 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
471 wpa_s->conf->auto_interworking)
472 return 1;
473
474 return 0;
475 }
476
477
478 /*
479 * Find the operating frequency of any other virtual interface that is using
480 * the same radio concurrently.
481 */
482 static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s)
483 {
484 const char *rn, *rn2;
485 struct wpa_supplicant *ifs;
486 u8 bssid[ETH_ALEN];
487
488 if (!wpa_s->driver->get_radio_name)
489 return -1;
490
491 rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv);
492 if (rn == NULL || rn[0] == '\0')
493 return -1;
494
495 for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) {
496 if (ifs == wpa_s || !ifs->driver->get_radio_name)
497 continue;
498
499 rn2 = ifs->driver->get_radio_name(ifs->drv_priv);
500 if (!rn2 || os_strcmp(rn, rn2) != 0)
501 continue;
502
503 if (ifs->current_ssid == NULL || ifs->assoc_freq == 0)
504 continue;
505
506 if (ifs->current_ssid->mode == WPAS_MODE_AP ||
507 ifs->current_ssid->mode == WPAS_MODE_P2P_GO)
508 return ifs->current_ssid->frequency;
509 if (wpa_drv_get_bssid(ifs, bssid) == 0)
510 return ifs->assoc_freq;
511 }
512
513 return 0;
514 }
515
516 #endif /* CONFIG_P2P */
517
518
519 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
520 {
521 struct wpa_supplicant *wpa_s = eloop_ctx;
522 struct wpa_ssid *ssid;
523 enum scan_req_type scan_req = NORMAL_SCAN_REQ;
524 int ret;
525 struct wpabuf *extra_ie = NULL;
526 struct wpa_driver_scan_params params;
527 struct wpa_driver_scan_params *scan_params;
528 size_t max_ssids;
529 enum wpa_states prev_state;
530
531 if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
532 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
533 return;
534 }
535
536 if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
537 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
538 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
539 return;
540 }
541
542 if (!wpa_supplicant_enabled_networks(wpa_s) &&
543 wpa_s->scan_req == NORMAL_SCAN_REQ) {
544 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
545 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
546 #ifdef CONFIG_P2P
547 wpa_s->sta_scan_pending = 0;
548 #endif /* CONFIG_P2P */
549 return;
550 }
551
552 if (wpa_s->conf->ap_scan != 0 &&
553 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
554 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
555 "overriding ap_scan configuration");
556 wpa_s->conf->ap_scan = 0;
557 wpas_notify_ap_scan_changed(wpa_s);
558 }
559
560 if (wpa_s->conf->ap_scan == 0) {
561 wpa_supplicant_gen_assoc_event(wpa_s);
562 return;
563 }
564
565 #ifdef CONFIG_P2P
566 if (wpas_p2p_in_progress(wpa_s)) {
567 if (wpa_s->sta_scan_pending &&
568 wpas_p2p_in_progress(wpa_s) == 2 &&
569 wpa_s->global->p2p_cb_on_scan_complete) {
570 wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
571 "mode scan during P2P search");
572 } else {
573 wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
574 "while P2P operation is in progress");
575 wpa_s->sta_scan_pending = 1;
576 wpa_supplicant_req_scan(wpa_s, 5, 0);
577 return;
578 }
579 }
580 #endif /* CONFIG_P2P */
581
582 if (wpa_s->conf->ap_scan == 2)
583 max_ssids = 1;
584 else {
585 max_ssids = wpa_s->max_scan_ssids;
586 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
587 max_ssids = WPAS_MAX_SCAN_SSIDS;
588 }
589
590 scan_req = wpa_s->scan_req;
591 wpa_s->scan_req = NORMAL_SCAN_REQ;
592
593 os_memset(&params, 0, sizeof(params));
594
595 prev_state = wpa_s->wpa_state;
596 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
597 wpa_s->wpa_state == WPA_INACTIVE)
598 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
599
600 /*
601 * If autoscan has set its own scanning parameters
602 */
603 if (wpa_s->autoscan_params != NULL) {
604 scan_params = wpa_s->autoscan_params;
605 goto scan;
606 }
607
608 if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
609 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
610 if (ssid == wpa_s->connect_without_scan)
611 break;
612 }
613 wpa_s->connect_without_scan = NULL;
614 if (ssid) {
615 wpa_printf(MSG_DEBUG, "Start a pre-selected network "
616 "without scan step");
617 wpa_supplicant_associate(wpa_s, NULL, ssid);
618 return;
619 }
620 }
621
622 #ifdef CONFIG_P2P
623 if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
624 wpa_s->go_params) {
625 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
626 "P2P group formation");
627 params.ssids[0].ssid = wpa_s->go_params->ssid;
628 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
629 params.num_ssids = 1;
630 goto ssid_list_set;
631 }
632 #endif /* CONFIG_P2P */
633
634 /* Find the starting point from which to continue scanning */
635 ssid = wpa_s->conf->ssid;
636 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
637 while (ssid) {
638 if (ssid == wpa_s->prev_scan_ssid) {
639 ssid = ssid->next;
640 break;
641 }
642 ssid = ssid->next;
643 }
644 }
645
646 if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
647 wpa_s->connect_without_scan = NULL;
648 wpa_s->prev_scan_wildcard = 0;
649 wpa_supplicant_assoc_try(wpa_s, ssid);
650 return;
651 } else if (wpa_s->conf->ap_scan == 2) {
652 /*
653 * User-initiated scan request in ap_scan == 2; scan with
654 * wildcard SSID.
655 */
656 ssid = NULL;
657 } else {
658 struct wpa_ssid *start = ssid, *tssid;
659 int freqs_set = 0;
660 if (ssid == NULL && max_ssids > 1)
661 ssid = wpa_s->conf->ssid;
662 while (ssid) {
663 if (!wpas_network_disabled(wpa_s, ssid) &&
664 ssid->scan_ssid) {
665 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
666 ssid->ssid, ssid->ssid_len);
667 params.ssids[params.num_ssids].ssid =
668 ssid->ssid;
669 params.ssids[params.num_ssids].ssid_len =
670 ssid->ssid_len;
671 params.num_ssids++;
672 if (params.num_ssids + 1 >= max_ssids)
673 break;
674 }
675 ssid = ssid->next;
676 if (ssid == start)
677 break;
678 if (ssid == NULL && max_ssids > 1 &&
679 start != wpa_s->conf->ssid)
680 ssid = wpa_s->conf->ssid;
681 }
682
683 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
684 if (wpas_network_disabled(wpa_s, tssid))
685 continue;
686 if ((params.freqs || !freqs_set) && tssid->scan_freq) {
687 int_array_concat(&params.freqs,
688 tssid->scan_freq);
689 } else {
690 os_free(params.freqs);
691 params.freqs = NULL;
692 }
693 freqs_set = 1;
694 }
695 int_array_sort_unique(params.freqs);
696 }
697
698 if (ssid && max_ssids == 1) {
699 /*
700 * If the driver is limited to 1 SSID at a time interleave
701 * wildcard SSID scans with specific SSID scans to avoid
702 * waiting a long time for a wildcard scan.
703 */
704 if (!wpa_s->prev_scan_wildcard) {
705 params.ssids[0].ssid = NULL;
706 params.ssids[0].ssid_len = 0;
707 wpa_s->prev_scan_wildcard = 1;
708 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
709 "wildcard SSID (Interleave with specific)");
710 } else {
711 wpa_s->prev_scan_ssid = ssid;
712 wpa_s->prev_scan_wildcard = 0;
713 wpa_dbg(wpa_s, MSG_DEBUG,
714 "Starting AP scan for specific SSID: %s",
715 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
716 }
717 } else if (ssid) {
718 /* max_ssids > 1 */
719
720 wpa_s->prev_scan_ssid = ssid;
721 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
722 "the scan request");
723 params.num_ssids++;
724 } else {
725 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
726 params.num_ssids++;
727 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
728 "SSID");
729 }
730 #ifdef CONFIG_P2P
731 ssid_list_set:
732 #endif /* CONFIG_P2P */
733
734 wpa_supplicant_optimize_freqs(wpa_s, &params);
735 extra_ie = wpa_supplicant_extra_ies(wpa_s);
736
737 #ifdef CONFIG_HS20
738 if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
739 wpas_hs20_add_indication(extra_ie);
740 #endif /* CONFIG_HS20 */
741
742 if (params.freqs == NULL && wpa_s->next_scan_freqs) {
743 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
744 "generated frequency list");
745 params.freqs = wpa_s->next_scan_freqs;
746 } else
747 os_free(wpa_s->next_scan_freqs);
748 wpa_s->next_scan_freqs = NULL;
749
750 params.filter_ssids = wpa_supplicant_build_filter_ssids(
751 wpa_s->conf, &params.num_filter_ssids);
752 if (extra_ie) {
753 params.extra_ies = wpabuf_head(extra_ie);
754 params.extra_ies_len = wpabuf_len(extra_ie);
755 }
756
757 #ifdef CONFIG_P2P
758 if (wpa_s->p2p_in_provisioning ||
759 (wpa_s->show_group_started && wpa_s->go_params)) {
760 /*
761 * The interface may not yet be in P2P mode, so we have to
762 * explicitly request P2P probe to disable CCK rates.
763 */
764 params.p2p_probe = 1;
765 }
766 #endif /* CONFIG_P2P */
767
768 scan_params = &params;
769
770 scan:
771 #ifdef CONFIG_P2P
772 /*
773 * If the driver does not support multi-channel concurrency and a
774 * virtual interface that shares the same radio with the wpa_s interface
775 * is operating there may not be need to scan other channels apart from
776 * the current operating channel on the other virtual interface. Filter
777 * out other channels in case we are trying to find a connection for a
778 * station interface when we are not configured to prefer station
779 * connection and a concurrent operation is already in process.
780 */
781 if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
782 !scan_params->freqs && !params.freqs &&
783 wpas_is_p2p_prioritized(wpa_s) &&
784 !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) &&
785 wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
786 non_p2p_network_enabled(wpa_s)) {
787 int freq = shared_vif_oper_freq(wpa_s);
788 if (freq > 0) {
789 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current "
790 "operating channel (%d MHz) since driver does "
791 "not support multi-channel concurrency", freq);
792 params.freqs = os_zalloc(sizeof(int) * 2);
793 if (params.freqs)
794 params.freqs[0] = freq;
795 scan_params->freqs = params.freqs;
796 }
797 }
798 #endif /* CONFIG_P2P */
799
800 ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
801
802 wpabuf_free(extra_ie);
803 os_free(params.freqs);
804 os_free(params.filter_ssids);
805
806 if (ret) {
807 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
808 if (prev_state != wpa_s->wpa_state)
809 wpa_supplicant_set_state(wpa_s, prev_state);
810 /* Restore scan_req since we will try to scan again */
811 wpa_s->scan_req = scan_req;
812 wpa_supplicant_req_scan(wpa_s, 1, 0);
813 } else {
814 wpa_s->scan_for_connection = 0;
815 }
816 }
817
818
819 /**
820 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
821 * @wpa_s: Pointer to wpa_supplicant data
822 * @sec: Number of seconds after which to scan
823 * @usec: Number of microseconds after which to scan
824 *
825 * This function is used to schedule a scan for neighboring access points after
826 * the specified time.
827 */
828 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
829 {
830 /* If there's at least one network that should be specifically scanned
831 * then don't cancel the scan and reschedule. Some drivers do
832 * background scanning which generates frequent scan results, and that
833 * causes the specific SSID scan to get continually pushed back and
834 * never happen, which causes hidden APs to never get probe-scanned.
835 */
836 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
837 wpa_s->conf->ap_scan == 1) {
838 struct wpa_ssid *ssid = wpa_s->conf->ssid;
839
840 while (ssid) {
841 if (!wpas_network_disabled(wpa_s, ssid) &&
842 ssid->scan_ssid)
843 break;
844 ssid = ssid->next;
845 }
846 if (ssid) {
847 wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
848 "ensure that specific SSID scans occur");
849 return;
850 }
851 }
852
853 wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
854 sec, usec);
855 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
856 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
857 }
858
859
860 /**
861 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
862 * @wpa_s: Pointer to wpa_supplicant data
863 * @sec: Number of seconds after which to scan
864 * @usec: Number of microseconds after which to scan
865 * Returns: 0 on success or -1 otherwise
866 *
867 * This function is used to schedule periodic scans for neighboring
868 * access points after the specified time.
869 */
870 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
871 int sec, int usec)
872 {
873 if (!wpa_s->sched_scan_supported)
874 return -1;
875
876 eloop_register_timeout(sec, usec,
877 wpa_supplicant_delayed_sched_scan_timeout,
878 wpa_s, NULL);
879
880 return 0;
881 }
882
883
884 /**
885 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
886 * @wpa_s: Pointer to wpa_supplicant data
887 * Returns: 0 is sched_scan was started or -1 otherwise
888 *
889 * This function is used to schedule periodic scans for neighboring
890 * access points repeating the scan continuously.
891 */
892 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
893 {
894 struct wpa_driver_scan_params params;
895 struct wpa_driver_scan_params *scan_params;
896 enum wpa_states prev_state;
897 struct wpa_ssid *ssid = NULL;
898 struct wpabuf *extra_ie = NULL;
899 int ret;
900 unsigned int max_sched_scan_ssids;
901 int wildcard = 0;
902 int need_ssids;
903
904 if (!wpa_s->sched_scan_supported)
905 return -1;
906
907 if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
908 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
909 else
910 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
911 if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
912 return -1;
913
914 if (wpa_s->sched_scanning) {
915 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
916 return 0;
917 }
918
919 need_ssids = 0;
920 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
921 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
922 /* Use wildcard SSID to find this network */
923 wildcard = 1;
924 } else if (!wpas_network_disabled(wpa_s, ssid) &&
925 ssid->ssid_len)
926 need_ssids++;
927
928 #ifdef CONFIG_WPS
929 if (!wpas_network_disabled(wpa_s, ssid) &&
930 ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
931 /*
932 * Normal scan is more reliable and faster for WPS
933 * operations and since these are for short periods of
934 * time, the benefit of trying to use sched_scan would
935 * be limited.
936 */
937 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
938 "sched_scan for WPS");
939 return -1;
940 }
941 #endif /* CONFIG_WPS */
942 }
943 if (wildcard)
944 need_ssids++;
945
946 if (wpa_s->normal_scans < 3 &&
947 (need_ssids <= wpa_s->max_scan_ssids ||
948 wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
949 /*
950 * When normal scan can speed up operations, use that for the
951 * first operations before starting the sched_scan to allow
952 * user space sleep more. We do this only if the normal scan
953 * has functionality that is suitable for this or if the
954 * sched_scan does not have better support for multiple SSIDs.
955 */
956 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
957 "sched_scan for initial scans (normal_scans=%d)",
958 wpa_s->normal_scans);
959 return -1;
960 }
961
962 os_memset(&params, 0, sizeof(params));
963
964 /* If we can't allocate space for the filters, we just don't filter */
965 params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
966 sizeof(struct wpa_driver_scan_filter));
967
968 prev_state = wpa_s->wpa_state;
969 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
970 wpa_s->wpa_state == WPA_INACTIVE)
971 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
972
973 if (wpa_s->autoscan_params != NULL) {
974 scan_params = wpa_s->autoscan_params;
975 goto scan;
976 }
977
978 /* Find the starting point from which to continue scanning */
979 ssid = wpa_s->conf->ssid;
980 if (wpa_s->prev_sched_ssid) {
981 while (ssid) {
982 if (ssid == wpa_s->prev_sched_ssid) {
983 ssid = ssid->next;
984 break;
985 }
986 ssid = ssid->next;
987 }
988 }
989
990 if (!ssid || !wpa_s->prev_sched_ssid) {
991 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
992
993 if (wpa_s->sched_scan_interval == 0)
994 wpa_s->sched_scan_interval = 10;
995 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
996 wpa_s->first_sched_scan = 1;
997 ssid = wpa_s->conf->ssid;
998 wpa_s->prev_sched_ssid = ssid;
999 }
1000
1001 if (wildcard) {
1002 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1003 params.num_ssids++;
1004 }
1005
1006 while (ssid) {
1007 if (wpas_network_disabled(wpa_s, ssid))
1008 goto next;
1009
1010 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1011 params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1012 wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1013 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1014 os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1015 ssid->ssid, ssid->ssid_len);
1016 params.filter_ssids[params.num_filter_ssids].ssid_len =
1017 ssid->ssid_len;
1018 params.num_filter_ssids++;
1019 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1020 {
1021 wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1022 "filter for sched_scan - drop filter");
1023 os_free(params.filter_ssids);
1024 params.filter_ssids = NULL;
1025 params.num_filter_ssids = 0;
1026 }
1027
1028 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1029 if (params.num_ssids == max_sched_scan_ssids)
1030 break; /* only room for broadcast SSID */
1031 wpa_dbg(wpa_s, MSG_DEBUG,
1032 "add to active scan ssid: %s",
1033 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1034 params.ssids[params.num_ssids].ssid =
1035 ssid->ssid;
1036 params.ssids[params.num_ssids].ssid_len =
1037 ssid->ssid_len;
1038 params.num_ssids++;
1039 if (params.num_ssids >= max_sched_scan_ssids) {
1040 wpa_s->prev_sched_ssid = ssid;
1041 do {
1042 ssid = ssid->next;
1043 } while (ssid &&
1044 (wpas_network_disabled(wpa_s, ssid) ||
1045 !ssid->scan_ssid));
1046 break;
1047 }
1048 }
1049
1050 next:
1051 wpa_s->prev_sched_ssid = ssid;
1052 ssid = ssid->next;
1053 }
1054
1055 if (params.num_filter_ssids == 0) {
1056 os_free(params.filter_ssids);
1057 params.filter_ssids = NULL;
1058 }
1059
1060 extra_ie = wpa_supplicant_extra_ies(wpa_s);
1061 if (extra_ie) {
1062 params.extra_ies = wpabuf_head(extra_ie);
1063 params.extra_ies_len = wpabuf_len(extra_ie);
1064 }
1065
1066 scan_params = &params;
1067
1068 scan:
1069 if (ssid || !wpa_s->first_sched_scan) {
1070 wpa_dbg(wpa_s, MSG_DEBUG,
1071 "Starting sched scan: interval %d timeout %d",
1072 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1073 } else {
1074 wpa_dbg(wpa_s, MSG_DEBUG,
1075 "Starting sched scan: interval %d (no timeout)",
1076 wpa_s->sched_scan_interval);
1077 }
1078
1079 ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1080 wpa_s->sched_scan_interval);
1081 wpabuf_free(extra_ie);
1082 os_free(params.filter_ssids);
1083 if (ret) {
1084 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1085 if (prev_state != wpa_s->wpa_state)
1086 wpa_supplicant_set_state(wpa_s, prev_state);
1087 return ret;
1088 }
1089
1090 /* If we have more SSIDs to scan, add a timeout so we scan them too */
1091 if (ssid || !wpa_s->first_sched_scan) {
1092 wpa_s->sched_scan_timed_out = 0;
1093 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1094 wpa_supplicant_sched_scan_timeout,
1095 wpa_s, NULL);
1096 wpa_s->first_sched_scan = 0;
1097 wpa_s->sched_scan_timeout /= 2;
1098 wpa_s->sched_scan_interval *= 2;
1099 }
1100
1101 return 0;
1102 }
1103
1104
1105 /**
1106 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1107 * @wpa_s: Pointer to wpa_supplicant data
1108 *
1109 * This function is used to cancel a scan request scheduled with
1110 * wpa_supplicant_req_scan().
1111 */
1112 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1113 {
1114 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1115 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1116 }
1117
1118
1119 /**
1120 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1121 * @wpa_s: Pointer to wpa_supplicant data
1122 *
1123 * This function is used to stop a periodic scheduled scan.
1124 */
1125 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1126 {
1127 if (!wpa_s->sched_scanning)
1128 return;
1129
1130 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1131 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1132 wpa_supplicant_stop_sched_scan(wpa_s);
1133 }
1134
1135
1136 /**
1137 * wpa_supplicant_notify_scanning - Indicate possible scan state change
1138 * @wpa_s: Pointer to wpa_supplicant data
1139 * @scanning: Whether scanning is currently in progress
1140 *
1141 * This function is to generate scanning notifycations. It is called whenever
1142 * there may have been a change in scanning (scan started, completed, stopped).
1143 * wpas_notify_scanning() is called whenever the scanning state changed from the
1144 * previously notified state.
1145 */
1146 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1147 int scanning)
1148 {
1149 if (wpa_s->scanning != scanning) {
1150 wpa_s->scanning = scanning;
1151 wpas_notify_scanning(wpa_s);
1152 }
1153 }
1154
1155
1156 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1157 {
1158 int rate = 0;
1159 const u8 *ie;
1160 int i;
1161
1162 ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1163 for (i = 0; ie && i < ie[1]; i++) {
1164 if ((ie[i + 2] & 0x7f) > rate)
1165 rate = ie[i + 2] & 0x7f;
1166 }
1167
1168 ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1169 for (i = 0; ie && i < ie[1]; i++) {
1170 if ((ie[i + 2] & 0x7f) > rate)
1171 rate = ie[i + 2] & 0x7f;
1172 }
1173
1174 return rate;
1175 }
1176
1177
1178 /**
1179 * wpa_scan_get_ie - Fetch a specified information element from a scan result
1180 * @res: Scan result entry
1181 * @ie: Information element identitifier (WLAN_EID_*)
1182 * Returns: Pointer to the information element (id field) or %NULL if not found
1183 *
1184 * This function returns the first matching information element in the scan
1185 * result.
1186 */
1187 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1188 {
1189 const u8 *end, *pos;
1190
1191 pos = (const u8 *) (res + 1);
1192 end = pos + res->ie_len;
1193
1194 while (pos + 1 < end) {
1195 if (pos + 2 + pos[1] > end)
1196 break;
1197 if (pos[0] == ie)
1198 return pos;
1199 pos += 2 + pos[1];
1200 }
1201
1202 return NULL;
1203 }
1204
1205
1206 /**
1207 * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1208 * @res: Scan result entry
1209 * @vendor_type: Vendor type (four octets starting the IE payload)
1210 * Returns: Pointer to the information element (id field) or %NULL if not found
1211 *
1212 * This function returns the first matching information element in the scan
1213 * result.
1214 */
1215 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1216 u32 vendor_type)
1217 {
1218 const u8 *end, *pos;
1219
1220 pos = (const u8 *) (res + 1);
1221 end = pos + res->ie_len;
1222
1223 while (pos + 1 < end) {
1224 if (pos + 2 + pos[1] > end)
1225 break;
1226 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1227 vendor_type == WPA_GET_BE32(&pos[2]))
1228 return pos;
1229 pos += 2 + pos[1];
1230 }
1231
1232 return NULL;
1233 }
1234
1235
1236 /**
1237 * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1238 * @res: Scan result entry
1239 * @vendor_type: Vendor type (four octets starting the IE payload)
1240 * Returns: Pointer to the information element payload or %NULL if not found
1241 *
1242 * This function returns concatenated payload of possibly fragmented vendor
1243 * specific information elements in the scan result. The caller is responsible
1244 * for freeing the returned buffer.
1245 */
1246 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1247 u32 vendor_type)
1248 {
1249 struct wpabuf *buf;
1250 const u8 *end, *pos;
1251
1252 buf = wpabuf_alloc(res->ie_len);
1253 if (buf == NULL)
1254 return NULL;
1255
1256 pos = (const u8 *) (res + 1);
1257 end = pos + res->ie_len;
1258
1259 while (pos + 1 < end) {
1260 if (pos + 2 + pos[1] > end)
1261 break;
1262 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1263 vendor_type == WPA_GET_BE32(&pos[2]))
1264 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1265 pos += 2 + pos[1];
1266 }
1267
1268 if (wpabuf_len(buf) == 0) {
1269 wpabuf_free(buf);
1270 buf = NULL;
1271 }
1272
1273 return buf;
1274 }
1275
1276
1277 /**
1278 * wpa_scan_get_vendor_ie_multi_beacon - Fetch vendor IE data from a scan result
1279 * @res: Scan result entry
1280 * @vendor_type: Vendor type (four octets starting the IE payload)
1281 * Returns: Pointer to the information element payload or %NULL if not found
1282 *
1283 * This function returns concatenated payload of possibly fragmented vendor
1284 * specific information elements in the scan result. The caller is responsible
1285 * for freeing the returned buffer.
1286 *
1287 * This function is like wpa_scan_get_vendor_ie_multi(), but uses IE buffer only
1288 * from Beacon frames instead of either Beacon or Probe Response frames.
1289 */
1290 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1291 const struct wpa_scan_res *res, u32 vendor_type)
1292 {
1293 struct wpabuf *buf;
1294 const u8 *end, *pos;
1295
1296 if (res->beacon_ie_len == 0)
1297 return NULL;
1298 buf = wpabuf_alloc(res->beacon_ie_len);
1299 if (buf == NULL)
1300 return NULL;
1301
1302 pos = (const u8 *) (res + 1);
1303 pos += res->ie_len;
1304 end = pos + res->beacon_ie_len;
1305
1306 while (pos + 1 < end) {
1307 if (pos + 2 + pos[1] > end)
1308 break;
1309 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1310 vendor_type == WPA_GET_BE32(&pos[2]))
1311 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1312 pos += 2 + pos[1];
1313 }
1314
1315 if (wpabuf_len(buf) == 0) {
1316 wpabuf_free(buf);
1317 buf = NULL;
1318 }
1319
1320 return buf;
1321 }
1322
1323
1324 /*
1325 * Channels with a great SNR can operate at full rate. What is a great SNR?
1326 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1327 * rule of thumb is that any SNR above 20 is good." This one
1328 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1329 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1330 * conservative value.
1331 */
1332 #define GREAT_SNR 30
1333
1334 /* Compare function for sorting scan results. Return >0 if @b is considered
1335 * better. */
1336 static int wpa_scan_result_compar(const void *a, const void *b)
1337 {
1338 #define IS_5GHZ(n) (n > 4000)
1339 #define MIN(a,b) a < b ? a : b
1340 struct wpa_scan_res **_wa = (void *) a;
1341 struct wpa_scan_res **_wb = (void *) b;
1342 struct wpa_scan_res *wa = *_wa;
1343 struct wpa_scan_res *wb = *_wb;
1344 int wpa_a, wpa_b, maxrate_a, maxrate_b;
1345 int snr_a, snr_b;
1346
1347 /* WPA/WPA2 support preferred */
1348 wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1349 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1350 wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1351 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1352
1353 if (wpa_b && !wpa_a)
1354 return 1;
1355 if (!wpa_b && wpa_a)
1356 return -1;
1357
1358 /* privacy support preferred */
1359 if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1360 (wb->caps & IEEE80211_CAP_PRIVACY))
1361 return 1;
1362 if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1363 (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1364 return -1;
1365
1366 if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1367 !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1368 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1369 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1370 } else {
1371 /* Not suitable information to calculate SNR, so use level */
1372 snr_a = wa->level;
1373 snr_b = wb->level;
1374 }
1375
1376 /* best/max rate preferred if SNR close enough */
1377 if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1378 (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1379 maxrate_a = wpa_scan_get_max_rate(wa);
1380 maxrate_b = wpa_scan_get_max_rate(wb);
1381 if (maxrate_a != maxrate_b)
1382 return maxrate_b - maxrate_a;
1383 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1384 return IS_5GHZ(wa->freq) ? -1 : 1;
1385 }
1386
1387 /* use freq for channel preference */
1388
1389 /* all things being equal, use SNR; if SNRs are
1390 * identical, use quality values since some drivers may only report
1391 * that value and leave the signal level zero */
1392 if (snr_b == snr_a)
1393 return wb->qual - wa->qual;
1394 return snr_b - snr_a;
1395 #undef MIN
1396 #undef IS_5GHZ
1397 }
1398
1399
1400 #ifdef CONFIG_WPS
1401 /* Compare function for sorting scan results when searching a WPS AP for
1402 * provisioning. Return >0 if @b is considered better. */
1403 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1404 {
1405 struct wpa_scan_res **_wa = (void *) a;
1406 struct wpa_scan_res **_wb = (void *) b;
1407 struct wpa_scan_res *wa = *_wa;
1408 struct wpa_scan_res *wb = *_wb;
1409 int uses_wps_a, uses_wps_b;
1410 struct wpabuf *wps_a, *wps_b;
1411 int res;
1412
1413 /* Optimization - check WPS IE existence before allocated memory and
1414 * doing full reassembly. */
1415 uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1416 uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1417 if (uses_wps_a && !uses_wps_b)
1418 return -1;
1419 if (!uses_wps_a && uses_wps_b)
1420 return 1;
1421
1422 if (uses_wps_a && uses_wps_b) {
1423 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1424 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1425 res = wps_ap_priority_compar(wps_a, wps_b);
1426 wpabuf_free(wps_a);
1427 wpabuf_free(wps_b);
1428 if (res)
1429 return res;
1430 }
1431
1432 /*
1433 * Do not use current AP security policy as a sorting criteria during
1434 * WPS provisioning step since the AP may get reconfigured at the
1435 * completion of provisioning.
1436 */
1437
1438 /* all things being equal, use signal level; if signal levels are
1439 * identical, use quality values since some drivers may only report
1440 * that value and leave the signal level zero */
1441 if (wb->level == wa->level)
1442 return wb->qual - wa->qual;
1443 return wb->level - wa->level;
1444 }
1445 #endif /* CONFIG_WPS */
1446
1447
1448 static void dump_scan_res(struct wpa_scan_results *scan_res)
1449 {
1450 #ifndef CONFIG_NO_STDOUT_DEBUG
1451 size_t i;
1452
1453 if (scan_res->res == NULL || scan_res->num == 0)
1454 return;
1455
1456 wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1457
1458 for (i = 0; i < scan_res->num; i++) {
1459 struct wpa_scan_res *r = scan_res->res[i];
1460 u8 *pos;
1461 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1462 == WPA_SCAN_LEVEL_DBM) {
1463 int snr = r->level - r->noise;
1464 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1465 "noise=%d level=%d snr=%d%s flags=0x%x",
1466 MAC2STR(r->bssid), r->freq, r->qual,
1467 r->noise, r->level, snr,
1468 snr >= GREAT_SNR ? "*" : "", r->flags);
1469 } else {
1470 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1471 "noise=%d level=%d flags=0x%x",
1472 MAC2STR(r->bssid), r->freq, r->qual,
1473 r->noise, r->level, r->flags);
1474 }
1475 pos = (u8 *) (r + 1);
1476 if (r->ie_len)
1477 wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1478 pos += r->ie_len;
1479 if (r->beacon_ie_len)
1480 wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1481 pos, r->beacon_ie_len);
1482 }
1483 #endif /* CONFIG_NO_STDOUT_DEBUG */
1484 }
1485
1486
1487 /**
1488 * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1489 * @wpa_s: Pointer to wpa_supplicant data
1490 * @bssid: BSSID to check
1491 * Returns: 0 if the BSSID is filtered or 1 if not
1492 *
1493 * This function is used to filter out specific BSSIDs from scan reslts mainly
1494 * for testing purposes (SET bssid_filter ctrl_iface command).
1495 */
1496 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1497 const u8 *bssid)
1498 {
1499 size_t i;
1500
1501 if (wpa_s->bssid_filter == NULL)
1502 return 1;
1503
1504 for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1505 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1506 ETH_ALEN) == 0)
1507 return 1;
1508 }
1509
1510 return 0;
1511 }
1512
1513
1514 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1515 struct wpa_scan_results *res)
1516 {
1517 size_t i, j;
1518
1519 if (wpa_s->bssid_filter == NULL)
1520 return;
1521
1522 for (i = 0, j = 0; i < res->num; i++) {
1523 if (wpa_supplicant_filter_bssid_match(wpa_s,
1524 res->res[i]->bssid)) {
1525 res->res[j++] = res->res[i];
1526 } else {
1527 os_free(res->res[i]);
1528 res->res[i] = NULL;
1529 }
1530 }
1531
1532 if (res->num != j) {
1533 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1534 (int) (res->num - j));
1535 res->num = j;
1536 }
1537 }
1538
1539
1540 /**
1541 * wpa_supplicant_get_scan_results - Get scan results
1542 * @wpa_s: Pointer to wpa_supplicant data
1543 * @info: Information about what was scanned or %NULL if not available
1544 * @new_scan: Whether a new scan was performed
1545 * Returns: Scan results, %NULL on failure
1546 *
1547 * This function request the current scan results from the driver and updates
1548 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1549 * results with wpa_scan_results_free().
1550 */
1551 struct wpa_scan_results *
1552 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1553 struct scan_info *info, int new_scan)
1554 {
1555 struct wpa_scan_results *scan_res;
1556 size_t i;
1557 int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1558
1559 scan_res = wpa_drv_get_scan_results2(wpa_s);
1560 if (scan_res == NULL) {
1561 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1562 return NULL;
1563 }
1564 filter_scan_res(wpa_s, scan_res);
1565
1566 #ifdef CONFIG_WPS
1567 if (wpas_wps_in_progress(wpa_s)) {
1568 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1569 "provisioning rules");
1570 compar = wpa_scan_result_wps_compar;
1571 }
1572 #endif /* CONFIG_WPS */
1573
1574 qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1575 compar);
1576 dump_scan_res(scan_res);
1577
1578 wpa_bss_update_start(wpa_s);
1579 for (i = 0; i < scan_res->num; i++)
1580 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1581 wpa_bss_update_end(wpa_s, info, new_scan);
1582
1583 return scan_res;
1584 }
1585
1586
1587 /**
1588 * wpa_supplicant_update_scan_results - Update scan results from the driver
1589 * @wpa_s: Pointer to wpa_supplicant data
1590 * Returns: 0 on success, -1 on failure
1591 *
1592 * This function updates the BSS table within wpa_supplicant based on the
1593 * currently available scan results from the driver without requesting a new
1594 * scan. This is used in cases where the driver indicates an association
1595 * (including roaming within ESS) and wpa_supplicant does not yet have the
1596 * needed information to complete the connection (e.g., to perform validation
1597 * steps in 4-way handshake).
1598 */
1599 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1600 {
1601 struct wpa_scan_results *scan_res;
1602 scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1603 if (scan_res == NULL)
1604 return -1;
1605 wpa_scan_results_free(scan_res);
1606
1607 return 0;
1608 }
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