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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 "common/wpa_ctrl.h"
15 #include "config.h"
16 #include "wpa_supplicant_i.h"
17 #include "driver_i.h"
18 #include "wps_supplicant.h"
19 #include "p2p_supplicant.h"
20 #include "p2p/p2p.h"
21 #include "hs20_supplicant.h"
22 #include "notify.h"
23 #include "bss.h"
24 #include "scan.h"
25
26
27 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
28 {
29 struct wpa_ssid *ssid;
30 union wpa_event_data data;
31
32 ssid = wpa_supplicant_get_ssid(wpa_s);
33 if (ssid == NULL)
34 return;
35
36 if (wpa_s->current_ssid == NULL) {
37 wpa_s->current_ssid = ssid;
38 if (wpa_s->current_ssid != NULL)
39 wpas_notify_network_changed(wpa_s);
40 }
41 wpa_supplicant_initiate_eapol(wpa_s);
42 wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
43 "network - generating associated event");
44 os_memset(&data, 0, sizeof(data));
45 wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
46 }
47
48
49 #ifdef CONFIG_WPS
50 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
51 enum wps_request_type *req_type)
52 {
53 struct wpa_ssid *ssid;
54 int wps = 0;
55
56 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
57 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
58 continue;
59
60 wps = 1;
61 *req_type = wpas_wps_get_req_type(ssid);
62 if (!ssid->eap.phase1)
63 continue;
64
65 if (os_strstr(ssid->eap.phase1, "pbc=1"))
66 return 2;
67 }
68
69 #ifdef CONFIG_P2P
70 if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p &&
71 !wpa_s->conf->p2p_disabled) {
72 wpa_s->wps->dev.p2p = 1;
73 if (!wps) {
74 wps = 1;
75 *req_type = WPS_REQ_ENROLLEE_INFO;
76 }
77 }
78 #endif /* CONFIG_P2P */
79
80 return wps;
81 }
82 #endif /* CONFIG_WPS */
83
84
85 /**
86 * wpa_supplicant_enabled_networks - Check whether there are enabled networks
87 * @wpa_s: Pointer to wpa_supplicant data
88 * Returns: 0 if no networks are enabled, >0 if networks are enabled
89 *
90 * This function is used to figure out whether any networks (or Interworking
91 * with enabled credentials and auto_interworking) are present in the current
92 * configuration.
93 */
94 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
95 {
96 struct wpa_ssid *ssid = wpa_s->conf->ssid;
97 int count = 0, disabled = 0;
98 while (ssid) {
99 if (!wpas_network_disabled(wpa_s, ssid))
100 count++;
101 else
102 disabled++;
103 ssid = ssid->next;
104 }
105 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
106 wpa_s->conf->auto_interworking)
107 count++;
108 if (count == 0 && disabled > 0) {
109 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled "
110 "networks)", disabled);
111 }
112 return count;
113 }
114
115
116 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
117 struct wpa_ssid *ssid)
118 {
119 while (ssid) {
120 if (!wpas_network_disabled(wpa_s, ssid))
121 break;
122 ssid = ssid->next;
123 }
124
125 /* ap_scan=2 mode - try to associate with each SSID. */
126 if (ssid == NULL) {
127 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
128 "end of scan list - go back to beginning");
129 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
130 wpa_supplicant_req_scan(wpa_s, 0, 0);
131 return;
132 }
133 if (ssid->next) {
134 /* Continue from the next SSID on the next attempt. */
135 wpa_s->prev_scan_ssid = ssid;
136 } else {
137 /* Start from the beginning of the SSID list. */
138 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
139 }
140 wpa_supplicant_associate(wpa_s, NULL, ssid);
141 }
142
143
144 static int int_array_len(const int *a)
145 {
146 int i;
147 for (i = 0; a && a[i]; i++)
148 ;
149 return i;
150 }
151
152
153 static void int_array_concat(int **res, const int *a)
154 {
155 int reslen, alen, i;
156 int *n;
157
158 reslen = int_array_len(*res);
159 alen = int_array_len(a);
160
161 n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
162 if (n == NULL) {
163 os_free(*res);
164 *res = NULL;
165 return;
166 }
167 for (i = 0; i <= alen; i++)
168 n[reslen + i] = a[i];
169 *res = n;
170 }
171
172
173 static int freq_cmp(const void *a, const void *b)
174 {
175 int _a = *(int *) a;
176 int _b = *(int *) b;
177
178 if (_a == 0)
179 return 1;
180 if (_b == 0)
181 return -1;
182 return _a - _b;
183 }
184
185
186 static void int_array_sort_unique(int *a)
187 {
188 int alen;
189 int i, j;
190
191 if (a == NULL)
192 return;
193
194 alen = int_array_len(a);
195 qsort(a, alen, sizeof(int), freq_cmp);
196
197 i = 0;
198 j = 1;
199 while (a[i] && a[j]) {
200 if (a[i] == a[j]) {
201 j++;
202 continue;
203 }
204 a[++i] = a[j++];
205 }
206 if (a[i])
207 i++;
208 a[i] = 0;
209 }
210
211
212 /**
213 * wpa_supplicant_trigger_scan - Request driver to start a scan
214 * @wpa_s: Pointer to wpa_supplicant data
215 * @params: Scan parameters
216 * Returns: 0 on success, -1 on failure
217 */
218 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
219 struct wpa_driver_scan_params *params)
220 {
221 int ret;
222
223 wpa_supplicant_notify_scanning(wpa_s, 1);
224
225 ret = wpa_drv_scan(wpa_s, params);
226 if (ret) {
227 wpa_supplicant_notify_scanning(wpa_s, 0);
228 wpas_notify_scan_done(wpa_s, 0);
229 } else {
230 os_get_time(&wpa_s->scan_trigger_time);
231 wpa_s->scan_runs++;
232 wpa_s->normal_scans++;
233 }
234
235 return ret;
236 }
237
238
239 static void
240 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
241 {
242 struct wpa_supplicant *wpa_s = eloop_ctx;
243
244 wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
245
246 if (wpa_supplicant_req_sched_scan(wpa_s))
247 wpa_supplicant_req_scan(wpa_s, 0, 0);
248 }
249
250
251 static void
252 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
253 {
254 struct wpa_supplicant *wpa_s = eloop_ctx;
255
256 wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
257
258 wpa_s->sched_scan_timed_out = 1;
259 wpa_supplicant_cancel_sched_scan(wpa_s);
260 }
261
262
263 static int
264 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
265 struct wpa_driver_scan_params *params,
266 int interval)
267 {
268 int ret;
269
270 wpa_supplicant_notify_scanning(wpa_s, 1);
271 ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
272 if (ret)
273 wpa_supplicant_notify_scanning(wpa_s, 0);
274 else
275 wpa_s->sched_scanning = 1;
276
277 return ret;
278 }
279
280
281 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
282 {
283 int ret;
284
285 ret = wpa_drv_stop_sched_scan(wpa_s);
286 if (ret) {
287 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
288 /* TODO: what to do if stopping fails? */
289 return -1;
290 }
291
292 return ret;
293 }
294
295
296 static struct wpa_driver_scan_filter *
297 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
298 {
299 struct wpa_driver_scan_filter *ssids;
300 struct wpa_ssid *ssid;
301 size_t count;
302
303 *num_ssids = 0;
304 if (!conf->filter_ssids)
305 return NULL;
306
307 for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
308 if (ssid->ssid && ssid->ssid_len)
309 count++;
310 }
311 if (count == 0)
312 return NULL;
313 ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
314 if (ssids == NULL)
315 return NULL;
316
317 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
318 if (!ssid->ssid || !ssid->ssid_len)
319 continue;
320 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
321 ssids[*num_ssids].ssid_len = ssid->ssid_len;
322 (*num_ssids)++;
323 }
324
325 return ssids;
326 }
327
328
329 static void wpa_supplicant_optimize_freqs(
330 struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
331 {
332 #ifdef CONFIG_P2P
333 if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
334 wpa_s->go_params) {
335 /* Optimize provisioning state scan based on GO information */
336 if (wpa_s->p2p_in_provisioning < 5 &&
337 wpa_s->go_params->freq > 0) {
338 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
339 "preferred frequency %d MHz",
340 wpa_s->go_params->freq);
341 params->freqs = os_zalloc(2 * sizeof(int));
342 if (params->freqs)
343 params->freqs[0] = wpa_s->go_params->freq;
344 } else if (wpa_s->p2p_in_provisioning < 8 &&
345 wpa_s->go_params->freq_list[0]) {
346 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
347 "channels");
348 int_array_concat(&params->freqs,
349 wpa_s->go_params->freq_list);
350 if (params->freqs)
351 int_array_sort_unique(params->freqs);
352 }
353 wpa_s->p2p_in_provisioning++;
354 }
355 #endif /* CONFIG_P2P */
356
357 #ifdef CONFIG_WPS
358 if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
359 /*
360 * Optimize post-provisioning scan based on channel used
361 * during provisioning.
362 */
363 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
364 "that was used during provisioning", wpa_s->wps_freq);
365 params->freqs = os_zalloc(2 * sizeof(int));
366 if (params->freqs)
367 params->freqs[0] = wpa_s->wps_freq;
368 wpa_s->after_wps--;
369 }
370
371 if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
372 {
373 /* Optimize provisioning scan based on already known channel */
374 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
375 wpa_s->wps_freq);
376 params->freqs = os_zalloc(2 * sizeof(int));
377 if (params->freqs)
378 params->freqs[0] = wpa_s->wps_freq;
379 wpa_s->known_wps_freq = 0; /* only do this once */
380 }
381 #endif /* CONFIG_WPS */
382 }
383
384
385 #ifdef CONFIG_INTERWORKING
386 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
387 struct wpabuf *buf)
388 {
389 if (wpa_s->conf->interworking == 0)
390 return;
391
392 wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
393 wpabuf_put_u8(buf, 4);
394 wpabuf_put_u8(buf, 0x00);
395 wpabuf_put_u8(buf, 0x00);
396 wpabuf_put_u8(buf, 0x00);
397 wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
398
399 wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
400 wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
401 1 + ETH_ALEN);
402 wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
403 /* No Venue Info */
404 if (!is_zero_ether_addr(wpa_s->conf->hessid))
405 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
406 }
407 #endif /* CONFIG_INTERWORKING */
408
409
410 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
411 {
412 struct wpabuf *extra_ie = NULL;
413 #ifdef CONFIG_WPS
414 int wps = 0;
415 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
416 #endif /* CONFIG_WPS */
417
418 #ifdef CONFIG_INTERWORKING
419 if (wpa_s->conf->interworking &&
420 wpabuf_resize(&extra_ie, 100) == 0)
421 wpas_add_interworking_elements(wpa_s, extra_ie);
422 #endif /* CONFIG_INTERWORKING */
423
424 #ifdef CONFIG_WPS
425 wps = wpas_wps_in_use(wpa_s, &req_type);
426
427 if (wps) {
428 struct wpabuf *wps_ie;
429 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
430 DEV_PW_DEFAULT,
431 &wpa_s->wps->dev,
432 wpa_s->wps->uuid, req_type,
433 0, NULL);
434 if (wps_ie) {
435 if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
436 wpabuf_put_buf(extra_ie, wps_ie);
437 wpabuf_free(wps_ie);
438 }
439 }
440
441 #ifdef CONFIG_P2P
442 if (wps) {
443 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
444 if (wpabuf_resize(&extra_ie, ielen) == 0)
445 wpas_p2p_scan_ie(wpa_s, extra_ie);
446 }
447 #endif /* CONFIG_P2P */
448
449 #endif /* CONFIG_WPS */
450
451 #ifdef CONFIG_HS20
452 if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0)
453 wpas_hs20_add_indication(extra_ie);
454 #endif /* CONFIG_HS20 */
455
456 return extra_ie;
457 }
458
459
460 #ifdef CONFIG_P2P
461
462 /*
463 * Check whether there are any enabled networks or credentials that could be
464 * used for a non-P2P connection.
465 */
466 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
467 {
468 struct wpa_ssid *ssid;
469
470 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
471 if (wpas_network_disabled(wpa_s, ssid))
472 continue;
473 if (!ssid->p2p_group)
474 return 1;
475 }
476
477 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
478 wpa_s->conf->auto_interworking)
479 return 1;
480
481 return 0;
482 }
483
484
485 /*
486 * Find the operating frequency of any other virtual interface that is using
487 * the same radio concurrently.
488 */
489 static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s)
490 {
491 const char *rn, *rn2;
492 struct wpa_supplicant *ifs;
493 u8 bssid[ETH_ALEN];
494
495 if (!wpa_s->driver->get_radio_name)
496 return -1;
497
498 rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv);
499 if (rn == NULL || rn[0] == '\0')
500 return -1;
501
502 for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) {
503 if (ifs == wpa_s || !ifs->driver->get_radio_name)
504 continue;
505
506 rn2 = ifs->driver->get_radio_name(ifs->drv_priv);
507 if (!rn2 || os_strcmp(rn, rn2) != 0)
508 continue;
509
510 if (ifs->current_ssid == NULL || ifs->assoc_freq == 0)
511 continue;
512
513 if (ifs->current_ssid->mode == WPAS_MODE_AP ||
514 ifs->current_ssid->mode == WPAS_MODE_P2P_GO)
515 return ifs->current_ssid->frequency;
516 if (wpa_drv_get_bssid(ifs, bssid) == 0)
517 return ifs->assoc_freq;
518 }
519
520 return 0;
521 }
522
523 #endif /* CONFIG_P2P */
524
525
526 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
527 {
528 struct wpa_supplicant *wpa_s = eloop_ctx;
529 struct wpa_ssid *ssid;
530 enum scan_req_type scan_req = NORMAL_SCAN_REQ;
531 int ret;
532 struct wpabuf *extra_ie = NULL;
533 struct wpa_driver_scan_params params;
534 struct wpa_driver_scan_params *scan_params;
535 size_t max_ssids;
536 enum wpa_states prev_state;
537
538 if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
539 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
540 wpas_p2p_continue_after_scan(wpa_s);
541 return;
542 }
543
544 if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
545 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
546 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
547 wpas_p2p_continue_after_scan(wpa_s);
548 return;
549 }
550
551 if (!wpa_supplicant_enabled_networks(wpa_s) &&
552 wpa_s->scan_req == NORMAL_SCAN_REQ) {
553 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
554 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
555 wpas_p2p_continue_after_scan(wpa_s);
556 return;
557 }
558
559 if (wpa_s->conf->ap_scan != 0 &&
560 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
561 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
562 "overriding ap_scan configuration");
563 wpa_s->conf->ap_scan = 0;
564 wpas_notify_ap_scan_changed(wpa_s);
565 }
566
567 if (wpa_s->conf->ap_scan == 0) {
568 wpa_supplicant_gen_assoc_event(wpa_s);
569 return;
570 }
571
572 #ifdef CONFIG_P2P
573 if (wpas_p2p_in_progress(wpa_s)) {
574 if (wpa_s->sta_scan_pending &&
575 wpas_p2p_in_progress(wpa_s) == 2 &&
576 wpa_s->global->p2p_cb_on_scan_complete) {
577 wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
578 "mode scan during P2P search");
579 } else {
580 wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
581 "while P2P operation is in progress");
582 wpa_s->sta_scan_pending = 1;
583 wpa_supplicant_req_scan(wpa_s, 5, 0);
584 return;
585 }
586 }
587 #endif /* CONFIG_P2P */
588
589 if (wpa_s->conf->ap_scan == 2)
590 max_ssids = 1;
591 else {
592 max_ssids = wpa_s->max_scan_ssids;
593 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
594 max_ssids = WPAS_MAX_SCAN_SSIDS;
595 }
596
597 scan_req = wpa_s->scan_req;
598 wpa_s->scan_req = NORMAL_SCAN_REQ;
599
600 os_memset(&params, 0, sizeof(params));
601
602 prev_state = wpa_s->wpa_state;
603 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
604 wpa_s->wpa_state == WPA_INACTIVE)
605 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
606
607 /*
608 * If autoscan has set its own scanning parameters
609 */
610 if (wpa_s->autoscan_params != NULL) {
611 scan_params = wpa_s->autoscan_params;
612 goto scan;
613 }
614
615 if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
616 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
617 if (ssid == wpa_s->connect_without_scan)
618 break;
619 }
620 wpa_s->connect_without_scan = NULL;
621 if (ssid) {
622 wpa_printf(MSG_DEBUG, "Start a pre-selected network "
623 "without scan step");
624 wpa_supplicant_associate(wpa_s, NULL, ssid);
625 return;
626 }
627 }
628
629 #ifdef CONFIG_P2P
630 if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
631 wpa_s->go_params) {
632 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
633 "P2P group formation");
634 params.ssids[0].ssid = wpa_s->go_params->ssid;
635 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
636 params.num_ssids = 1;
637 goto ssid_list_set;
638 }
639 #endif /* CONFIG_P2P */
640
641 /* Find the starting point from which to continue scanning */
642 ssid = wpa_s->conf->ssid;
643 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
644 while (ssid) {
645 if (ssid == wpa_s->prev_scan_ssid) {
646 ssid = ssid->next;
647 break;
648 }
649 ssid = ssid->next;
650 }
651 }
652
653 if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
654 wpa_s->connect_without_scan = NULL;
655 wpa_s->prev_scan_wildcard = 0;
656 wpa_supplicant_assoc_try(wpa_s, ssid);
657 return;
658 } else if (wpa_s->conf->ap_scan == 2) {
659 /*
660 * User-initiated scan request in ap_scan == 2; scan with
661 * wildcard SSID.
662 */
663 ssid = NULL;
664 } else {
665 struct wpa_ssid *start = ssid, *tssid;
666 int freqs_set = 0;
667 if (ssid == NULL && max_ssids > 1)
668 ssid = wpa_s->conf->ssid;
669 while (ssid) {
670 if (!wpas_network_disabled(wpa_s, ssid) &&
671 ssid->scan_ssid) {
672 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
673 ssid->ssid, ssid->ssid_len);
674 params.ssids[params.num_ssids].ssid =
675 ssid->ssid;
676 params.ssids[params.num_ssids].ssid_len =
677 ssid->ssid_len;
678 params.num_ssids++;
679 if (params.num_ssids + 1 >= max_ssids)
680 break;
681 }
682 ssid = ssid->next;
683 if (ssid == start)
684 break;
685 if (ssid == NULL && max_ssids > 1 &&
686 start != wpa_s->conf->ssid)
687 ssid = wpa_s->conf->ssid;
688 }
689
690 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
691 if (wpas_network_disabled(wpa_s, tssid))
692 continue;
693 if ((params.freqs || !freqs_set) && tssid->scan_freq) {
694 int_array_concat(&params.freqs,
695 tssid->scan_freq);
696 } else {
697 os_free(params.freqs);
698 params.freqs = NULL;
699 }
700 freqs_set = 1;
701 }
702 int_array_sort_unique(params.freqs);
703 }
704
705 if (ssid && max_ssids == 1) {
706 /*
707 * If the driver is limited to 1 SSID at a time interleave
708 * wildcard SSID scans with specific SSID scans to avoid
709 * waiting a long time for a wildcard scan.
710 */
711 if (!wpa_s->prev_scan_wildcard) {
712 params.ssids[0].ssid = NULL;
713 params.ssids[0].ssid_len = 0;
714 wpa_s->prev_scan_wildcard = 1;
715 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
716 "wildcard SSID (Interleave with specific)");
717 } else {
718 wpa_s->prev_scan_ssid = ssid;
719 wpa_s->prev_scan_wildcard = 0;
720 wpa_dbg(wpa_s, MSG_DEBUG,
721 "Starting AP scan for specific SSID: %s",
722 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
723 }
724 } else if (ssid) {
725 /* max_ssids > 1 */
726
727 wpa_s->prev_scan_ssid = ssid;
728 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
729 "the scan request");
730 params.num_ssids++;
731 } else {
732 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
733 params.num_ssids++;
734 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
735 "SSID");
736 }
737 #ifdef CONFIG_P2P
738 ssid_list_set:
739 #endif /* CONFIG_P2P */
740
741 wpa_supplicant_optimize_freqs(wpa_s, &params);
742 extra_ie = wpa_supplicant_extra_ies(wpa_s);
743
744 if (params.freqs == NULL && wpa_s->next_scan_freqs) {
745 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
746 "generated frequency list");
747 params.freqs = wpa_s->next_scan_freqs;
748 } else
749 os_free(wpa_s->next_scan_freqs);
750 wpa_s->next_scan_freqs = NULL;
751
752 params.filter_ssids = wpa_supplicant_build_filter_ssids(
753 wpa_s->conf, &params.num_filter_ssids);
754 if (extra_ie) {
755 params.extra_ies = wpabuf_head(extra_ie);
756 params.extra_ies_len = wpabuf_len(extra_ie);
757 }
758
759 #ifdef CONFIG_P2P
760 if (wpa_s->p2p_in_provisioning ||
761 (wpa_s->show_group_started && wpa_s->go_params)) {
762 /*
763 * The interface may not yet be in P2P mode, so we have to
764 * explicitly request P2P probe to disable CCK rates.
765 */
766 params.p2p_probe = 1;
767 }
768 #endif /* CONFIG_P2P */
769
770 scan_params = &params;
771
772 scan:
773 #ifdef CONFIG_P2P
774 /*
775 * If the driver does not support multi-channel concurrency and a
776 * virtual interface that shares the same radio with the wpa_s interface
777 * is operating there may not be need to scan other channels apart from
778 * the current operating channel on the other virtual interface. Filter
779 * out other channels in case we are trying to find a connection for a
780 * station interface when we are not configured to prefer station
781 * connection and a concurrent operation is already in process.
782 */
783 if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
784 !scan_params->freqs && !params.freqs &&
785 wpas_is_p2p_prioritized(wpa_s) &&
786 !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) &&
787 wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
788 non_p2p_network_enabled(wpa_s)) {
789 int freq = shared_vif_oper_freq(wpa_s);
790 if (freq > 0) {
791 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current "
792 "operating channel (%d MHz) since driver does "
793 "not support multi-channel concurrency", freq);
794 params.freqs = os_zalloc(sizeof(int) * 2);
795 if (params.freqs)
796 params.freqs[0] = freq;
797 scan_params->freqs = params.freqs;
798 }
799 }
800 #endif /* CONFIG_P2P */
801
802 ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
803
804 wpabuf_free(extra_ie);
805 os_free(params.freqs);
806 os_free(params.filter_ssids);
807
808 if (ret) {
809 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
810 if (prev_state != wpa_s->wpa_state)
811 wpa_supplicant_set_state(wpa_s, prev_state);
812 /* Restore scan_req since we will try to scan again */
813 wpa_s->scan_req = scan_req;
814 wpa_supplicant_req_scan(wpa_s, 1, 0);
815 } else {
816 wpa_s->scan_for_connection = 0;
817 }
818 }
819
820
821 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
822 {
823 struct os_time remaining, new_int;
824 int cancelled;
825
826 cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
827 &remaining);
828
829 new_int.sec = sec;
830 new_int.usec = 0;
831 if (cancelled && os_time_before(&remaining, &new_int)) {
832 new_int.sec = remaining.sec;
833 new_int.usec = remaining.usec;
834 }
835
836 eloop_register_timeout(new_int.sec, new_int.usec, wpa_supplicant_scan,
837 wpa_s, NULL);
838 wpa_s->scan_interval = sec;
839 }
840
841
842 /**
843 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
844 * @wpa_s: Pointer to wpa_supplicant data
845 * @sec: Number of seconds after which to scan
846 * @usec: Number of microseconds after which to scan
847 *
848 * This function is used to schedule a scan for neighboring access points after
849 * the specified time.
850 */
851 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
852 {
853 /* If there's at least one network that should be specifically scanned
854 * then don't cancel the scan and reschedule. Some drivers do
855 * background scanning which generates frequent scan results, and that
856 * causes the specific SSID scan to get continually pushed back and
857 * never happen, which causes hidden APs to never get probe-scanned.
858 */
859 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
860 wpa_s->conf->ap_scan == 1) {
861 struct wpa_ssid *ssid = wpa_s->conf->ssid;
862
863 while (ssid) {
864 if (!wpas_network_disabled(wpa_s, ssid) &&
865 ssid->scan_ssid)
866 break;
867 ssid = ssid->next;
868 }
869 if (ssid) {
870 wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
871 "ensure that specific SSID scans occur");
872 return;
873 }
874 }
875
876 wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
877 sec, usec);
878 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
879 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
880 }
881
882
883 /**
884 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
885 * @wpa_s: Pointer to wpa_supplicant data
886 * @sec: Number of seconds after which to scan
887 * @usec: Number of microseconds after which to scan
888 * Returns: 0 on success or -1 otherwise
889 *
890 * This function is used to schedule periodic scans for neighboring
891 * access points after the specified time.
892 */
893 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
894 int sec, int usec)
895 {
896 if (!wpa_s->sched_scan_supported)
897 return -1;
898
899 eloop_register_timeout(sec, usec,
900 wpa_supplicant_delayed_sched_scan_timeout,
901 wpa_s, NULL);
902
903 return 0;
904 }
905
906
907 /**
908 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
909 * @wpa_s: Pointer to wpa_supplicant data
910 * Returns: 0 is sched_scan was started or -1 otherwise
911 *
912 * This function is used to schedule periodic scans for neighboring
913 * access points repeating the scan continuously.
914 */
915 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
916 {
917 struct wpa_driver_scan_params params;
918 struct wpa_driver_scan_params *scan_params;
919 enum wpa_states prev_state;
920 struct wpa_ssid *ssid = NULL;
921 struct wpabuf *extra_ie = NULL;
922 int ret;
923 unsigned int max_sched_scan_ssids;
924 int wildcard = 0;
925 int need_ssids;
926
927 if (!wpa_s->sched_scan_supported)
928 return -1;
929
930 if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
931 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
932 else
933 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
934 if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
935 return -1;
936
937 if (wpa_s->sched_scanning) {
938 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
939 return 0;
940 }
941
942 need_ssids = 0;
943 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
944 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
945 /* Use wildcard SSID to find this network */
946 wildcard = 1;
947 } else if (!wpas_network_disabled(wpa_s, ssid) &&
948 ssid->ssid_len)
949 need_ssids++;
950
951 #ifdef CONFIG_WPS
952 if (!wpas_network_disabled(wpa_s, ssid) &&
953 ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
954 /*
955 * Normal scan is more reliable and faster for WPS
956 * operations and since these are for short periods of
957 * time, the benefit of trying to use sched_scan would
958 * be limited.
959 */
960 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
961 "sched_scan for WPS");
962 return -1;
963 }
964 #endif /* CONFIG_WPS */
965 }
966 if (wildcard)
967 need_ssids++;
968
969 if (wpa_s->normal_scans < 3 &&
970 (need_ssids <= wpa_s->max_scan_ssids ||
971 wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
972 /*
973 * When normal scan can speed up operations, use that for the
974 * first operations before starting the sched_scan to allow
975 * user space sleep more. We do this only if the normal scan
976 * has functionality that is suitable for this or if the
977 * sched_scan does not have better support for multiple SSIDs.
978 */
979 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
980 "sched_scan for initial scans (normal_scans=%d)",
981 wpa_s->normal_scans);
982 return -1;
983 }
984
985 os_memset(&params, 0, sizeof(params));
986
987 /* If we can't allocate space for the filters, we just don't filter */
988 params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
989 sizeof(struct wpa_driver_scan_filter));
990
991 prev_state = wpa_s->wpa_state;
992 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
993 wpa_s->wpa_state == WPA_INACTIVE)
994 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
995
996 if (wpa_s->autoscan_params != NULL) {
997 scan_params = wpa_s->autoscan_params;
998 goto scan;
999 }
1000
1001 /* Find the starting point from which to continue scanning */
1002 ssid = wpa_s->conf->ssid;
1003 if (wpa_s->prev_sched_ssid) {
1004 while (ssid) {
1005 if (ssid == wpa_s->prev_sched_ssid) {
1006 ssid = ssid->next;
1007 break;
1008 }
1009 ssid = ssid->next;
1010 }
1011 }
1012
1013 if (!ssid || !wpa_s->prev_sched_ssid) {
1014 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1015
1016 if (wpa_s->sched_scan_interval == 0)
1017 wpa_s->sched_scan_interval = 10;
1018 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1019 wpa_s->first_sched_scan = 1;
1020 ssid = wpa_s->conf->ssid;
1021 wpa_s->prev_sched_ssid = ssid;
1022 }
1023
1024 if (wildcard) {
1025 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1026 params.num_ssids++;
1027 }
1028
1029 while (ssid) {
1030 if (wpas_network_disabled(wpa_s, ssid))
1031 goto next;
1032
1033 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1034 params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1035 wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1036 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1037 os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1038 ssid->ssid, ssid->ssid_len);
1039 params.filter_ssids[params.num_filter_ssids].ssid_len =
1040 ssid->ssid_len;
1041 params.num_filter_ssids++;
1042 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1043 {
1044 wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1045 "filter for sched_scan - drop filter");
1046 os_free(params.filter_ssids);
1047 params.filter_ssids = NULL;
1048 params.num_filter_ssids = 0;
1049 }
1050
1051 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1052 if (params.num_ssids == max_sched_scan_ssids)
1053 break; /* only room for broadcast SSID */
1054 wpa_dbg(wpa_s, MSG_DEBUG,
1055 "add to active scan ssid: %s",
1056 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1057 params.ssids[params.num_ssids].ssid =
1058 ssid->ssid;
1059 params.ssids[params.num_ssids].ssid_len =
1060 ssid->ssid_len;
1061 params.num_ssids++;
1062 if (params.num_ssids >= max_sched_scan_ssids) {
1063 wpa_s->prev_sched_ssid = ssid;
1064 do {
1065 ssid = ssid->next;
1066 } while (ssid &&
1067 (wpas_network_disabled(wpa_s, ssid) ||
1068 !ssid->scan_ssid));
1069 break;
1070 }
1071 }
1072
1073 next:
1074 wpa_s->prev_sched_ssid = ssid;
1075 ssid = ssid->next;
1076 }
1077
1078 if (params.num_filter_ssids == 0) {
1079 os_free(params.filter_ssids);
1080 params.filter_ssids = NULL;
1081 }
1082
1083 extra_ie = wpa_supplicant_extra_ies(wpa_s);
1084 if (extra_ie) {
1085 params.extra_ies = wpabuf_head(extra_ie);
1086 params.extra_ies_len = wpabuf_len(extra_ie);
1087 }
1088
1089 scan_params = &params;
1090
1091 scan:
1092 if (ssid || !wpa_s->first_sched_scan) {
1093 wpa_dbg(wpa_s, MSG_DEBUG,
1094 "Starting sched scan: interval %d timeout %d",
1095 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1096 } else {
1097 wpa_dbg(wpa_s, MSG_DEBUG,
1098 "Starting sched scan: interval %d (no timeout)",
1099 wpa_s->sched_scan_interval);
1100 }
1101
1102 ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1103 wpa_s->sched_scan_interval);
1104 wpabuf_free(extra_ie);
1105 os_free(params.filter_ssids);
1106 if (ret) {
1107 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1108 if (prev_state != wpa_s->wpa_state)
1109 wpa_supplicant_set_state(wpa_s, prev_state);
1110 return ret;
1111 }
1112
1113 /* If we have more SSIDs to scan, add a timeout so we scan them too */
1114 if (ssid || !wpa_s->first_sched_scan) {
1115 wpa_s->sched_scan_timed_out = 0;
1116 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1117 wpa_supplicant_sched_scan_timeout,
1118 wpa_s, NULL);
1119 wpa_s->first_sched_scan = 0;
1120 wpa_s->sched_scan_timeout /= 2;
1121 wpa_s->sched_scan_interval *= 2;
1122 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1123 wpa_s->sched_scan_interval = 10;
1124 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1125 }
1126 }
1127
1128 /* If there is no more ssids, start next time from the beginning */
1129 if (!ssid)
1130 wpa_s->prev_sched_ssid = NULL;
1131
1132 return 0;
1133 }
1134
1135
1136 /**
1137 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1138 * @wpa_s: Pointer to wpa_supplicant data
1139 *
1140 * This function is used to cancel a scan request scheduled with
1141 * wpa_supplicant_req_scan().
1142 */
1143 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1144 {
1145 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1146 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1147 wpas_p2p_continue_after_scan(wpa_s);
1148 }
1149
1150
1151 /**
1152 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1153 * @wpa_s: Pointer to wpa_supplicant data
1154 *
1155 * This function is used to stop a periodic scheduled scan.
1156 */
1157 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1158 {
1159 if (!wpa_s->sched_scanning)
1160 return;
1161
1162 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1163 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1164 wpa_supplicant_stop_sched_scan(wpa_s);
1165 }
1166
1167
1168 /**
1169 * wpa_supplicant_notify_scanning - Indicate possible scan state change
1170 * @wpa_s: Pointer to wpa_supplicant data
1171 * @scanning: Whether scanning is currently in progress
1172 *
1173 * This function is to generate scanning notifycations. It is called whenever
1174 * there may have been a change in scanning (scan started, completed, stopped).
1175 * wpas_notify_scanning() is called whenever the scanning state changed from the
1176 * previously notified state.
1177 */
1178 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1179 int scanning)
1180 {
1181 if (wpa_s->scanning != scanning) {
1182 wpa_s->scanning = scanning;
1183 wpas_notify_scanning(wpa_s);
1184 }
1185 }
1186
1187
1188 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1189 {
1190 int rate = 0;
1191 const u8 *ie;
1192 int i;
1193
1194 ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1195 for (i = 0; ie && i < ie[1]; i++) {
1196 if ((ie[i + 2] & 0x7f) > rate)
1197 rate = ie[i + 2] & 0x7f;
1198 }
1199
1200 ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1201 for (i = 0; ie && i < ie[1]; i++) {
1202 if ((ie[i + 2] & 0x7f) > rate)
1203 rate = ie[i + 2] & 0x7f;
1204 }
1205
1206 return rate;
1207 }
1208
1209
1210 /**
1211 * wpa_scan_get_ie - Fetch a specified information element from a scan result
1212 * @res: Scan result entry
1213 * @ie: Information element identitifier (WLAN_EID_*)
1214 * Returns: Pointer to the information element (id field) or %NULL if not found
1215 *
1216 * This function returns the first matching information element in the scan
1217 * result.
1218 */
1219 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1220 {
1221 const u8 *end, *pos;
1222
1223 pos = (const u8 *) (res + 1);
1224 end = pos + res->ie_len;
1225
1226 while (pos + 1 < end) {
1227 if (pos + 2 + pos[1] > end)
1228 break;
1229 if (pos[0] == ie)
1230 return pos;
1231 pos += 2 + pos[1];
1232 }
1233
1234 return NULL;
1235 }
1236
1237
1238 /**
1239 * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1240 * @res: Scan result entry
1241 * @vendor_type: Vendor type (four octets starting the IE payload)
1242 * Returns: Pointer to the information element (id field) or %NULL if not found
1243 *
1244 * This function returns the first matching information element in the scan
1245 * result.
1246 */
1247 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1248 u32 vendor_type)
1249 {
1250 const u8 *end, *pos;
1251
1252 pos = (const u8 *) (res + 1);
1253 end = pos + res->ie_len;
1254
1255 while (pos + 1 < end) {
1256 if (pos + 2 + pos[1] > end)
1257 break;
1258 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1259 vendor_type == WPA_GET_BE32(&pos[2]))
1260 return pos;
1261 pos += 2 + pos[1];
1262 }
1263
1264 return NULL;
1265 }
1266
1267
1268 /**
1269 * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1270 * @res: Scan result entry
1271 * @vendor_type: Vendor type (four octets starting the IE payload)
1272 * Returns: Pointer to the information element payload or %NULL if not found
1273 *
1274 * This function returns concatenated payload of possibly fragmented vendor
1275 * specific information elements in the scan result. The caller is responsible
1276 * for freeing the returned buffer.
1277 */
1278 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1279 u32 vendor_type)
1280 {
1281 struct wpabuf *buf;
1282 const u8 *end, *pos;
1283
1284 buf = wpabuf_alloc(res->ie_len);
1285 if (buf == NULL)
1286 return NULL;
1287
1288 pos = (const u8 *) (res + 1);
1289 end = pos + res->ie_len;
1290
1291 while (pos + 1 < end) {
1292 if (pos + 2 + pos[1] > end)
1293 break;
1294 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1295 vendor_type == WPA_GET_BE32(&pos[2]))
1296 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1297 pos += 2 + pos[1];
1298 }
1299
1300 if (wpabuf_len(buf) == 0) {
1301 wpabuf_free(buf);
1302 buf = NULL;
1303 }
1304
1305 return buf;
1306 }
1307
1308
1309 /*
1310 * Channels with a great SNR can operate at full rate. What is a great SNR?
1311 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1312 * rule of thumb is that any SNR above 20 is good." This one
1313 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1314 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1315 * conservative value.
1316 */
1317 #define GREAT_SNR 30
1318
1319 /* Compare function for sorting scan results. Return >0 if @b is considered
1320 * better. */
1321 static int wpa_scan_result_compar(const void *a, const void *b)
1322 {
1323 #define IS_5GHZ(n) (n > 4000)
1324 #define MIN(a,b) a < b ? a : b
1325 struct wpa_scan_res **_wa = (void *) a;
1326 struct wpa_scan_res **_wb = (void *) b;
1327 struct wpa_scan_res *wa = *_wa;
1328 struct wpa_scan_res *wb = *_wb;
1329 int wpa_a, wpa_b, maxrate_a, maxrate_b;
1330 int snr_a, snr_b;
1331
1332 /* WPA/WPA2 support preferred */
1333 wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1334 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1335 wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1336 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1337
1338 if (wpa_b && !wpa_a)
1339 return 1;
1340 if (!wpa_b && wpa_a)
1341 return -1;
1342
1343 /* privacy support preferred */
1344 if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1345 (wb->caps & IEEE80211_CAP_PRIVACY))
1346 return 1;
1347 if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1348 (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1349 return -1;
1350
1351 if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1352 !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1353 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1354 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1355 } else {
1356 /* Not suitable information to calculate SNR, so use level */
1357 snr_a = wa->level;
1358 snr_b = wb->level;
1359 }
1360
1361 /* best/max rate preferred if SNR close enough */
1362 if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1363 (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1364 maxrate_a = wpa_scan_get_max_rate(wa);
1365 maxrate_b = wpa_scan_get_max_rate(wb);
1366 if (maxrate_a != maxrate_b)
1367 return maxrate_b - maxrate_a;
1368 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1369 return IS_5GHZ(wa->freq) ? -1 : 1;
1370 }
1371
1372 /* use freq for channel preference */
1373
1374 /* all things being equal, use SNR; if SNRs are
1375 * identical, use quality values since some drivers may only report
1376 * that value and leave the signal level zero */
1377 if (snr_b == snr_a)
1378 return wb->qual - wa->qual;
1379 return snr_b - snr_a;
1380 #undef MIN
1381 #undef IS_5GHZ
1382 }
1383
1384
1385 #ifdef CONFIG_WPS
1386 /* Compare function for sorting scan results when searching a WPS AP for
1387 * provisioning. Return >0 if @b is considered better. */
1388 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1389 {
1390 struct wpa_scan_res **_wa = (void *) a;
1391 struct wpa_scan_res **_wb = (void *) b;
1392 struct wpa_scan_res *wa = *_wa;
1393 struct wpa_scan_res *wb = *_wb;
1394 int uses_wps_a, uses_wps_b;
1395 struct wpabuf *wps_a, *wps_b;
1396 int res;
1397
1398 /* Optimization - check WPS IE existence before allocated memory and
1399 * doing full reassembly. */
1400 uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1401 uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1402 if (uses_wps_a && !uses_wps_b)
1403 return -1;
1404 if (!uses_wps_a && uses_wps_b)
1405 return 1;
1406
1407 if (uses_wps_a && uses_wps_b) {
1408 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1409 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1410 res = wps_ap_priority_compar(wps_a, wps_b);
1411 wpabuf_free(wps_a);
1412 wpabuf_free(wps_b);
1413 if (res)
1414 return res;
1415 }
1416
1417 /*
1418 * Do not use current AP security policy as a sorting criteria during
1419 * WPS provisioning step since the AP may get reconfigured at the
1420 * completion of provisioning.
1421 */
1422
1423 /* all things being equal, use signal level; if signal levels are
1424 * identical, use quality values since some drivers may only report
1425 * that value and leave the signal level zero */
1426 if (wb->level == wa->level)
1427 return wb->qual - wa->qual;
1428 return wb->level - wa->level;
1429 }
1430 #endif /* CONFIG_WPS */
1431
1432
1433 static void dump_scan_res(struct wpa_scan_results *scan_res)
1434 {
1435 #ifndef CONFIG_NO_STDOUT_DEBUG
1436 size_t i;
1437
1438 if (scan_res->res == NULL || scan_res->num == 0)
1439 return;
1440
1441 wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1442
1443 for (i = 0; i < scan_res->num; i++) {
1444 struct wpa_scan_res *r = scan_res->res[i];
1445 u8 *pos;
1446 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1447 == WPA_SCAN_LEVEL_DBM) {
1448 int snr = r->level - r->noise;
1449 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1450 "noise=%d level=%d snr=%d%s flags=0x%x "
1451 "age=%u",
1452 MAC2STR(r->bssid), r->freq, r->qual,
1453 r->noise, r->level, snr,
1454 snr >= GREAT_SNR ? "*" : "", r->flags,
1455 r->age);
1456 } else {
1457 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1458 "noise=%d level=%d flags=0x%x age=%u",
1459 MAC2STR(r->bssid), r->freq, r->qual,
1460 r->noise, r->level, r->flags, r->age);
1461 }
1462 pos = (u8 *) (r + 1);
1463 if (r->ie_len)
1464 wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1465 pos += r->ie_len;
1466 if (r->beacon_ie_len)
1467 wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1468 pos, r->beacon_ie_len);
1469 }
1470 #endif /* CONFIG_NO_STDOUT_DEBUG */
1471 }
1472
1473
1474 /**
1475 * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1476 * @wpa_s: Pointer to wpa_supplicant data
1477 * @bssid: BSSID to check
1478 * Returns: 0 if the BSSID is filtered or 1 if not
1479 *
1480 * This function is used to filter out specific BSSIDs from scan reslts mainly
1481 * for testing purposes (SET bssid_filter ctrl_iface command).
1482 */
1483 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1484 const u8 *bssid)
1485 {
1486 size_t i;
1487
1488 if (wpa_s->bssid_filter == NULL)
1489 return 1;
1490
1491 for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1492 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1493 ETH_ALEN) == 0)
1494 return 1;
1495 }
1496
1497 return 0;
1498 }
1499
1500
1501 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1502 struct wpa_scan_results *res)
1503 {
1504 size_t i, j;
1505
1506 if (wpa_s->bssid_filter == NULL)
1507 return;
1508
1509 for (i = 0, j = 0; i < res->num; i++) {
1510 if (wpa_supplicant_filter_bssid_match(wpa_s,
1511 res->res[i]->bssid)) {
1512 res->res[j++] = res->res[i];
1513 } else {
1514 os_free(res->res[i]);
1515 res->res[i] = NULL;
1516 }
1517 }
1518
1519 if (res->num != j) {
1520 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1521 (int) (res->num - j));
1522 res->num = j;
1523 }
1524 }
1525
1526
1527 /**
1528 * wpa_supplicant_get_scan_results - Get scan results
1529 * @wpa_s: Pointer to wpa_supplicant data
1530 * @info: Information about what was scanned or %NULL if not available
1531 * @new_scan: Whether a new scan was performed
1532 * Returns: Scan results, %NULL on failure
1533 *
1534 * This function request the current scan results from the driver and updates
1535 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1536 * results with wpa_scan_results_free().
1537 */
1538 struct wpa_scan_results *
1539 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1540 struct scan_info *info, int new_scan)
1541 {
1542 struct wpa_scan_results *scan_res;
1543 size_t i;
1544 int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1545
1546 scan_res = wpa_drv_get_scan_results2(wpa_s);
1547 if (scan_res == NULL) {
1548 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1549 return NULL;
1550 }
1551 if (scan_res->fetch_time.sec == 0) {
1552 /*
1553 * Make sure we have a valid timestamp if the driver wrapper
1554 * does not set this.
1555 */
1556 os_get_time(&scan_res->fetch_time);
1557 }
1558 filter_scan_res(wpa_s, scan_res);
1559
1560 #ifdef CONFIG_WPS
1561 if (wpas_wps_in_progress(wpa_s)) {
1562 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1563 "provisioning rules");
1564 compar = wpa_scan_result_wps_compar;
1565 }
1566 #endif /* CONFIG_WPS */
1567
1568 qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1569 compar);
1570 dump_scan_res(scan_res);
1571
1572 wpa_bss_update_start(wpa_s);
1573 for (i = 0; i < scan_res->num; i++)
1574 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1575 &scan_res->fetch_time);
1576 wpa_bss_update_end(wpa_s, info, new_scan);
1577
1578 return scan_res;
1579 }
1580
1581
1582 /**
1583 * wpa_supplicant_update_scan_results - Update scan results from the driver
1584 * @wpa_s: Pointer to wpa_supplicant data
1585 * Returns: 0 on success, -1 on failure
1586 *
1587 * This function updates the BSS table within wpa_supplicant based on the
1588 * currently available scan results from the driver without requesting a new
1589 * scan. This is used in cases where the driver indicates an association
1590 * (including roaming within ESS) and wpa_supplicant does not yet have the
1591 * needed information to complete the connection (e.g., to perform validation
1592 * steps in 4-way handshake).
1593 */
1594 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1595 {
1596 struct wpa_scan_results *scan_res;
1597 scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1598 if (scan_res == NULL)
1599 return -1;
1600 wpa_scan_results_free(scan_res);
1601
1602 return 0;
1603 }
1604
1605
1606 /**
1607 * scan_only_handler - Reports scan results
1608 */
1609 void scan_only_handler(struct wpa_supplicant *wpa_s,
1610 struct wpa_scan_results *scan_res)
1611 {
1612 wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1613 wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1614 wpas_notify_scan_results(wpa_s);
1615 wpas_notify_scan_done(wpa_s, 1);
1616 }
1617
1618
1619 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1620 {
1621 return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1622 }
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