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Don't start second scan when changing scan interval
[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 "gas_query.h"
25 #include "scan.h"
26
27
28 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
29 {
30 struct wpa_ssid *ssid;
31 union wpa_event_data data;
32
33 ssid = wpa_supplicant_get_ssid(wpa_s);
34 if (ssid == NULL)
35 return;
36
37 if (wpa_s->current_ssid == NULL) {
38 wpa_s->current_ssid = ssid;
39 if (wpa_s->current_ssid != NULL)
40 wpas_notify_network_changed(wpa_s);
41 }
42 wpa_supplicant_initiate_eapol(wpa_s);
43 wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
44 "network - generating associated event");
45 os_memset(&data, 0, sizeof(data));
46 wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
47 }
48
49
50 #ifdef CONFIG_WPS
51 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
52 enum wps_request_type *req_type)
53 {
54 struct wpa_ssid *ssid;
55 int wps = 0;
56
57 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
58 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
59 continue;
60
61 wps = 1;
62 *req_type = wpas_wps_get_req_type(ssid);
63 if (!ssid->eap.phase1)
64 continue;
65
66 if (os_strstr(ssid->eap.phase1, "pbc=1"))
67 return 2;
68 }
69
70 #ifdef CONFIG_P2P
71 if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p &&
72 !wpa_s->conf->p2p_disabled) {
73 wpa_s->wps->dev.p2p = 1;
74 if (!wps) {
75 wps = 1;
76 *req_type = WPS_REQ_ENROLLEE_INFO;
77 }
78 }
79 #endif /* CONFIG_P2P */
80
81 return wps;
82 }
83 #endif /* CONFIG_WPS */
84
85
86 /**
87 * wpa_supplicant_enabled_networks - Check whether there are enabled networks
88 * @wpa_s: Pointer to wpa_supplicant data
89 * Returns: 0 if no networks are enabled, >0 if networks are enabled
90 *
91 * This function is used to figure out whether any networks (or Interworking
92 * with enabled credentials and auto_interworking) are present in the current
93 * configuration.
94 */
95 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
96 {
97 struct wpa_ssid *ssid = wpa_s->conf->ssid;
98 int count = 0, disabled = 0;
99 while (ssid) {
100 if (!wpas_network_disabled(wpa_s, ssid))
101 count++;
102 else
103 disabled++;
104 ssid = ssid->next;
105 }
106 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
107 wpa_s->conf->auto_interworking)
108 count++;
109 if (count == 0 && disabled > 0) {
110 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled "
111 "networks)", disabled);
112 }
113 return count;
114 }
115
116
117 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
118 struct wpa_ssid *ssid)
119 {
120 while (ssid) {
121 if (!wpas_network_disabled(wpa_s, ssid))
122 break;
123 ssid = ssid->next;
124 }
125
126 /* ap_scan=2 mode - try to associate with each SSID. */
127 if (ssid == NULL) {
128 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
129 "end of scan list - go back to beginning");
130 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
131 wpa_supplicant_req_scan(wpa_s, 0, 0);
132 return;
133 }
134 if (ssid->next) {
135 /* Continue from the next SSID on the next attempt. */
136 wpa_s->prev_scan_ssid = ssid;
137 } else {
138 /* Start from the beginning of the SSID list. */
139 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
140 }
141 wpa_supplicant_associate(wpa_s, NULL, ssid);
142 }
143
144
145 static int int_array_len(const int *a)
146 {
147 int i;
148 for (i = 0; a && a[i]; i++)
149 ;
150 return i;
151 }
152
153
154 static void int_array_concat(int **res, const int *a)
155 {
156 int reslen, alen, i;
157 int *n;
158
159 reslen = int_array_len(*res);
160 alen = int_array_len(a);
161
162 n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
163 if (n == NULL) {
164 os_free(*res);
165 *res = NULL;
166 return;
167 }
168 for (i = 0; i <= alen; i++)
169 n[reslen + i] = a[i];
170 *res = n;
171 }
172
173
174 static int freq_cmp(const void *a, const void *b)
175 {
176 int _a = *(int *) a;
177 int _b = *(int *) b;
178
179 if (_a == 0)
180 return 1;
181 if (_b == 0)
182 return -1;
183 return _a - _b;
184 }
185
186
187 static void int_array_sort_unique(int *a)
188 {
189 int alen;
190 int i, j;
191
192 if (a == NULL)
193 return;
194
195 alen = int_array_len(a);
196 qsort(a, alen, sizeof(int), freq_cmp);
197
198 i = 0;
199 j = 1;
200 while (a[i] && a[j]) {
201 if (a[i] == a[j]) {
202 j++;
203 continue;
204 }
205 a[++i] = a[j++];
206 }
207 if (a[i])
208 i++;
209 a[i] = 0;
210 }
211
212
213 /**
214 * wpa_supplicant_trigger_scan - Request driver to start a scan
215 * @wpa_s: Pointer to wpa_supplicant data
216 * @params: Scan parameters
217 * Returns: 0 on success, -1 on failure
218 */
219 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
220 struct wpa_driver_scan_params *params)
221 {
222 int ret;
223
224 wpa_supplicant_notify_scanning(wpa_s, 1);
225
226 ret = wpa_drv_scan(wpa_s, params);
227 if (ret) {
228 wpa_supplicant_notify_scanning(wpa_s, 0);
229 wpas_notify_scan_done(wpa_s, 0);
230 } else {
231 os_get_time(&wpa_s->scan_trigger_time);
232 wpa_s->scan_runs++;
233 wpa_s->normal_scans++;
234 }
235
236 return ret;
237 }
238
239
240 static void
241 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
242 {
243 struct wpa_supplicant *wpa_s = eloop_ctx;
244
245 wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
246
247 if (wpa_supplicant_req_sched_scan(wpa_s))
248 wpa_supplicant_req_scan(wpa_s, 0, 0);
249 }
250
251
252 static void
253 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
254 {
255 struct wpa_supplicant *wpa_s = eloop_ctx;
256
257 wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
258
259 wpa_s->sched_scan_timed_out = 1;
260 wpa_supplicant_cancel_sched_scan(wpa_s);
261 }
262
263
264 static int
265 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
266 struct wpa_driver_scan_params *params,
267 int interval)
268 {
269 int ret;
270
271 wpa_supplicant_notify_scanning(wpa_s, 1);
272 ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
273 if (ret)
274 wpa_supplicant_notify_scanning(wpa_s, 0);
275 else
276 wpa_s->sched_scanning = 1;
277
278 return ret;
279 }
280
281
282 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
283 {
284 int ret;
285
286 ret = wpa_drv_stop_sched_scan(wpa_s);
287 if (ret) {
288 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
289 /* TODO: what to do if stopping fails? */
290 return -1;
291 }
292
293 return ret;
294 }
295
296
297 static struct wpa_driver_scan_filter *
298 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
299 {
300 struct wpa_driver_scan_filter *ssids;
301 struct wpa_ssid *ssid;
302 size_t count;
303
304 *num_ssids = 0;
305 if (!conf->filter_ssids)
306 return NULL;
307
308 for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
309 if (ssid->ssid && ssid->ssid_len)
310 count++;
311 }
312 if (count == 0)
313 return NULL;
314 ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
315 if (ssids == NULL)
316 return NULL;
317
318 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
319 if (!ssid->ssid || !ssid->ssid_len)
320 continue;
321 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
322 ssids[*num_ssids].ssid_len = ssid->ssid_len;
323 (*num_ssids)++;
324 }
325
326 return ssids;
327 }
328
329
330 static void wpa_supplicant_optimize_freqs(
331 struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
332 {
333 #ifdef CONFIG_P2P
334 if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
335 wpa_s->go_params) {
336 /* Optimize provisioning state scan based on GO information */
337 if (wpa_s->p2p_in_provisioning < 5 &&
338 wpa_s->go_params->freq > 0) {
339 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
340 "preferred frequency %d MHz",
341 wpa_s->go_params->freq);
342 params->freqs = os_zalloc(2 * sizeof(int));
343 if (params->freqs)
344 params->freqs[0] = wpa_s->go_params->freq;
345 } else if (wpa_s->p2p_in_provisioning < 8 &&
346 wpa_s->go_params->freq_list[0]) {
347 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
348 "channels");
349 int_array_concat(&params->freqs,
350 wpa_s->go_params->freq_list);
351 if (params->freqs)
352 int_array_sort_unique(params->freqs);
353 }
354 wpa_s->p2p_in_provisioning++;
355 }
356 #endif /* CONFIG_P2P */
357
358 #ifdef CONFIG_WPS
359 if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
360 /*
361 * Optimize post-provisioning scan based on channel used
362 * during provisioning.
363 */
364 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
365 "that was used during provisioning", wpa_s->wps_freq);
366 params->freqs = os_zalloc(2 * sizeof(int));
367 if (params->freqs)
368 params->freqs[0] = wpa_s->wps_freq;
369 wpa_s->after_wps--;
370 }
371
372 if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
373 {
374 /* Optimize provisioning scan based on already known channel */
375 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
376 wpa_s->wps_freq);
377 params->freqs = os_zalloc(2 * sizeof(int));
378 if (params->freqs)
379 params->freqs[0] = wpa_s->wps_freq;
380 wpa_s->known_wps_freq = 0; /* only do this once */
381 }
382 #endif /* CONFIG_WPS */
383 }
384
385
386 #ifdef CONFIG_INTERWORKING
387 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
388 struct wpabuf *buf)
389 {
390 if (wpa_s->conf->interworking == 0)
391 return;
392
393 wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
394 wpabuf_put_u8(buf, 4);
395 wpabuf_put_u8(buf, 0x00);
396 wpabuf_put_u8(buf, 0x00);
397 wpabuf_put_u8(buf, 0x00);
398 wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
399
400 wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
401 wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
402 1 + ETH_ALEN);
403 wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
404 /* No Venue Info */
405 if (!is_zero_ether_addr(wpa_s->conf->hessid))
406 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
407 }
408 #endif /* CONFIG_INTERWORKING */
409
410
411 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
412 {
413 struct wpabuf *extra_ie = NULL;
414 #ifdef CONFIG_WPS
415 int wps = 0;
416 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
417 #endif /* CONFIG_WPS */
418
419 #ifdef CONFIG_INTERWORKING
420 if (wpa_s->conf->interworking &&
421 wpabuf_resize(&extra_ie, 100) == 0)
422 wpas_add_interworking_elements(wpa_s, extra_ie);
423 #endif /* CONFIG_INTERWORKING */
424
425 #ifdef CONFIG_WPS
426 wps = wpas_wps_in_use(wpa_s, &req_type);
427
428 if (wps) {
429 struct wpabuf *wps_ie;
430 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
431 DEV_PW_DEFAULT,
432 &wpa_s->wps->dev,
433 wpa_s->wps->uuid, req_type,
434 0, NULL);
435 if (wps_ie) {
436 if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
437 wpabuf_put_buf(extra_ie, wps_ie);
438 wpabuf_free(wps_ie);
439 }
440 }
441
442 #ifdef CONFIG_P2P
443 if (wps) {
444 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
445 if (wpabuf_resize(&extra_ie, ielen) == 0)
446 wpas_p2p_scan_ie(wpa_s, extra_ie);
447 }
448 #endif /* CONFIG_P2P */
449
450 #endif /* CONFIG_WPS */
451
452 #ifdef CONFIG_HS20
453 if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0)
454 wpas_hs20_add_indication(extra_ie);
455 #endif /* CONFIG_HS20 */
456
457 return extra_ie;
458 }
459
460
461 #ifdef CONFIG_P2P
462
463 /*
464 * Check whether there are any enabled networks or credentials that could be
465 * used for a non-P2P connection.
466 */
467 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
468 {
469 struct wpa_ssid *ssid;
470
471 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
472 if (wpas_network_disabled(wpa_s, ssid))
473 continue;
474 if (!ssid->p2p_group)
475 return 1;
476 }
477
478 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
479 wpa_s->conf->auto_interworking)
480 return 1;
481
482 return 0;
483 }
484
485 #endif /* CONFIG_P2P */
486
487
488 static struct hostapd_hw_modes * get_mode(struct hostapd_hw_modes *modes,
489 u16 num_modes,
490 enum hostapd_hw_mode mode)
491 {
492 u16 i;
493
494 for (i = 0; i < num_modes; i++) {
495 if (modes[i].mode == mode)
496 return &modes[i];
497 }
498
499 return NULL;
500 }
501
502
503 static void wpa_setband_scan_freqs_list(struct wpa_supplicant *wpa_s,
504 enum hostapd_hw_mode band,
505 struct wpa_driver_scan_params *params)
506 {
507 /* Include only supported channels for the specified band */
508 struct hostapd_hw_modes *mode;
509 int count, i;
510
511 mode = get_mode(wpa_s->hw.modes, wpa_s->hw.num_modes, band);
512 if (mode == NULL) {
513 /* No channels supported in this band - use empty list */
514 params->freqs = os_zalloc(sizeof(int));
515 return;
516 }
517
518 params->freqs = os_zalloc((mode->num_channels + 1) * sizeof(int));
519 if (params->freqs == NULL)
520 return;
521 for (count = 0, i = 0; i < mode->num_channels; i++) {
522 if (mode->channels[i].flag & HOSTAPD_CHAN_DISABLED)
523 continue;
524 params->freqs[count++] = mode->channels[i].freq;
525 }
526 }
527
528
529 static void wpa_setband_scan_freqs(struct wpa_supplicant *wpa_s,
530 struct wpa_driver_scan_params *params)
531 {
532 if (wpa_s->hw.modes == NULL)
533 return; /* unknown what channels the driver supports */
534 if (params->freqs)
535 return; /* already using a limited channel set */
536 if (wpa_s->setband == WPA_SETBAND_5G)
537 wpa_setband_scan_freqs_list(wpa_s, HOSTAPD_MODE_IEEE80211A,
538 params);
539 else if (wpa_s->setband == WPA_SETBAND_2G)
540 wpa_setband_scan_freqs_list(wpa_s, HOSTAPD_MODE_IEEE80211G,
541 params);
542 }
543
544
545 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
546 {
547 struct wpa_supplicant *wpa_s = eloop_ctx;
548 struct wpa_ssid *ssid;
549 enum scan_req_type scan_req = NORMAL_SCAN_REQ;
550 int ret;
551 struct wpabuf *extra_ie = NULL;
552 struct wpa_driver_scan_params params;
553 struct wpa_driver_scan_params *scan_params;
554 size_t max_ssids;
555 enum wpa_states prev_state;
556
557 if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
558 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
559 wpas_p2p_continue_after_scan(wpa_s);
560 return;
561 }
562
563 if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
564 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
565 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
566 wpas_p2p_continue_after_scan(wpa_s);
567 return;
568 }
569
570 if (!wpa_supplicant_enabled_networks(wpa_s) &&
571 wpa_s->scan_req == NORMAL_SCAN_REQ) {
572 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
573 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
574 wpas_p2p_continue_after_scan(wpa_s);
575 return;
576 }
577
578 if (wpa_s->conf->ap_scan != 0 &&
579 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
580 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
581 "overriding ap_scan configuration");
582 wpa_s->conf->ap_scan = 0;
583 wpas_notify_ap_scan_changed(wpa_s);
584 }
585
586 if (wpa_s->conf->ap_scan == 0) {
587 wpa_supplicant_gen_assoc_event(wpa_s);
588 return;
589 }
590
591 #ifdef CONFIG_P2P
592 if (wpas_p2p_in_progress(wpa_s) || wpas_wpa_is_in_progress(wpa_s, 0)) {
593 if (wpa_s->sta_scan_pending &&
594 wpas_p2p_in_progress(wpa_s) == 2 &&
595 wpa_s->global->p2p_cb_on_scan_complete) {
596 wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
597 "mode scan during P2P search");
598 } else {
599 wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
600 "while P2P operation is in progress");
601 wpa_s->sta_scan_pending = 1;
602 wpa_supplicant_req_scan(wpa_s, 5, 0);
603 return;
604 }
605 }
606 #endif /* CONFIG_P2P */
607
608 #ifdef CONFIG_GAS
609 if (gas_query_in_progress(wpa_s->gas)) {
610 wpa_dbg(wpa_s, MSG_DEBUG, "Delay scan while GAS query is in progress");
611 wpa_supplicant_req_scan(wpa_s, 1, 0);
612 return;
613 }
614 #endif /* CONFIG_GAS */
615
616 if (wpa_s->conf->ap_scan == 2)
617 max_ssids = 1;
618 else {
619 max_ssids = wpa_s->max_scan_ssids;
620 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
621 max_ssids = WPAS_MAX_SCAN_SSIDS;
622 }
623
624 scan_req = wpa_s->scan_req;
625 wpa_s->scan_req = NORMAL_SCAN_REQ;
626
627 os_memset(&params, 0, sizeof(params));
628
629 prev_state = wpa_s->wpa_state;
630 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
631 wpa_s->wpa_state == WPA_INACTIVE)
632 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
633
634 /*
635 * If autoscan has set its own scanning parameters
636 */
637 if (wpa_s->autoscan_params != NULL) {
638 scan_params = wpa_s->autoscan_params;
639 goto scan;
640 }
641
642 if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
643 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
644 if (ssid == wpa_s->connect_without_scan)
645 break;
646 }
647 wpa_s->connect_without_scan = NULL;
648 if (ssid) {
649 wpa_printf(MSG_DEBUG, "Start a pre-selected network "
650 "without scan step");
651 wpa_supplicant_associate(wpa_s, NULL, ssid);
652 return;
653 }
654 }
655
656 #ifdef CONFIG_P2P
657 if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
658 wpa_s->go_params) {
659 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
660 "P2P group formation");
661 params.ssids[0].ssid = wpa_s->go_params->ssid;
662 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
663 params.num_ssids = 1;
664 goto ssid_list_set;
665 }
666 #endif /* CONFIG_P2P */
667
668 /* Find the starting point from which to continue scanning */
669 ssid = wpa_s->conf->ssid;
670 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
671 while (ssid) {
672 if (ssid == wpa_s->prev_scan_ssid) {
673 ssid = ssid->next;
674 break;
675 }
676 ssid = ssid->next;
677 }
678 }
679
680 if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
681 wpa_s->connect_without_scan = NULL;
682 wpa_s->prev_scan_wildcard = 0;
683 wpa_supplicant_assoc_try(wpa_s, ssid);
684 return;
685 } else if (wpa_s->conf->ap_scan == 2) {
686 /*
687 * User-initiated scan request in ap_scan == 2; scan with
688 * wildcard SSID.
689 */
690 ssid = NULL;
691 } else {
692 struct wpa_ssid *start = ssid, *tssid;
693 int freqs_set = 0;
694 if (ssid == NULL && max_ssids > 1)
695 ssid = wpa_s->conf->ssid;
696 while (ssid) {
697 if (!wpas_network_disabled(wpa_s, ssid) &&
698 ssid->scan_ssid) {
699 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
700 ssid->ssid, ssid->ssid_len);
701 params.ssids[params.num_ssids].ssid =
702 ssid->ssid;
703 params.ssids[params.num_ssids].ssid_len =
704 ssid->ssid_len;
705 params.num_ssids++;
706 if (params.num_ssids + 1 >= max_ssids)
707 break;
708 }
709 ssid = ssid->next;
710 if (ssid == start)
711 break;
712 if (ssid == NULL && max_ssids > 1 &&
713 start != wpa_s->conf->ssid)
714 ssid = wpa_s->conf->ssid;
715 }
716
717 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
718 if (wpas_network_disabled(wpa_s, tssid))
719 continue;
720 if ((params.freqs || !freqs_set) && tssid->scan_freq) {
721 int_array_concat(&params.freqs,
722 tssid->scan_freq);
723 } else {
724 os_free(params.freqs);
725 params.freqs = NULL;
726 }
727 freqs_set = 1;
728 }
729 int_array_sort_unique(params.freqs);
730 }
731
732 if (ssid && max_ssids == 1) {
733 /*
734 * If the driver is limited to 1 SSID at a time interleave
735 * wildcard SSID scans with specific SSID scans to avoid
736 * waiting a long time for a wildcard scan.
737 */
738 if (!wpa_s->prev_scan_wildcard) {
739 params.ssids[0].ssid = NULL;
740 params.ssids[0].ssid_len = 0;
741 wpa_s->prev_scan_wildcard = 1;
742 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
743 "wildcard SSID (Interleave with specific)");
744 } else {
745 wpa_s->prev_scan_ssid = ssid;
746 wpa_s->prev_scan_wildcard = 0;
747 wpa_dbg(wpa_s, MSG_DEBUG,
748 "Starting AP scan for specific SSID: %s",
749 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
750 }
751 } else if (ssid) {
752 /* max_ssids > 1 */
753
754 wpa_s->prev_scan_ssid = ssid;
755 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
756 "the scan request");
757 params.num_ssids++;
758 } else {
759 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
760 params.num_ssids++;
761 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
762 "SSID");
763 }
764 #ifdef CONFIG_P2P
765 ssid_list_set:
766 #endif /* CONFIG_P2P */
767
768 wpa_supplicant_optimize_freqs(wpa_s, &params);
769 extra_ie = wpa_supplicant_extra_ies(wpa_s);
770
771 if (params.freqs == NULL && wpa_s->next_scan_freqs) {
772 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
773 "generated frequency list");
774 params.freqs = wpa_s->next_scan_freqs;
775 } else
776 os_free(wpa_s->next_scan_freqs);
777 wpa_s->next_scan_freqs = NULL;
778 wpa_setband_scan_freqs(wpa_s, &params);
779
780 /* See if user specified frequencies. If so, scan only those. */
781 if (wpa_s->conf->freq_list && !params.freqs) {
782 wpa_dbg(wpa_s, MSG_DEBUG,
783 "Optimize scan based on conf->freq_list");
784 int_array_concat(&params.freqs, wpa_s->conf->freq_list);
785 }
786
787 /* Use current associated channel? */
788 if (wpa_s->conf->scan_cur_freq && !params.freqs) {
789 unsigned int num = wpa_s->num_multichan_concurrent;
790
791 params.freqs = os_calloc(num + 1, sizeof(int));
792 if (params.freqs) {
793 num = get_shared_radio_freqs(wpa_s, params.freqs, num);
794 if (num > 0) {
795 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the "
796 "current operating channels since "
797 "scan_cur_freq is enabled");
798 } else {
799 os_free(params.freqs);
800 params.freqs = NULL;
801 }
802 }
803 }
804
805 params.filter_ssids = wpa_supplicant_build_filter_ssids(
806 wpa_s->conf, &params.num_filter_ssids);
807 if (extra_ie) {
808 params.extra_ies = wpabuf_head(extra_ie);
809 params.extra_ies_len = wpabuf_len(extra_ie);
810 }
811
812 #ifdef CONFIG_P2P
813 if (wpa_s->p2p_in_provisioning ||
814 (wpa_s->show_group_started && wpa_s->go_params)) {
815 /*
816 * The interface may not yet be in P2P mode, so we have to
817 * explicitly request P2P probe to disable CCK rates.
818 */
819 params.p2p_probe = 1;
820 }
821 #endif /* CONFIG_P2P */
822
823 scan_params = &params;
824
825 scan:
826 #ifdef CONFIG_P2P
827 /*
828 * If the driver does not support multi-channel concurrency and a
829 * virtual interface that shares the same radio with the wpa_s interface
830 * is operating there may not be need to scan other channels apart from
831 * the current operating channel on the other virtual interface. Filter
832 * out other channels in case we are trying to find a connection for a
833 * station interface when we are not configured to prefer station
834 * connection and a concurrent operation is already in process.
835 */
836 if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
837 !scan_params->freqs && !params.freqs &&
838 wpas_is_p2p_prioritized(wpa_s) &&
839 wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
840 non_p2p_network_enabled(wpa_s)) {
841 unsigned int num = wpa_s->num_multichan_concurrent;
842
843 params.freqs = os_calloc(num + 1, sizeof(int));
844 if (params.freqs) {
845 num = get_shared_radio_freqs(wpa_s, params.freqs, num);
846 if (num > 0 && num == wpa_s->num_multichan_concurrent) {
847 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the current operating channels since all channels are already used");
848 } else {
849 os_free(params.freqs);
850 params.freqs = NULL;
851 }
852 }
853 }
854 #endif /* CONFIG_P2P */
855
856 ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
857
858 wpabuf_free(extra_ie);
859 os_free(params.freqs);
860 os_free(params.filter_ssids);
861
862 if (ret) {
863 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
864 if (prev_state != wpa_s->wpa_state)
865 wpa_supplicant_set_state(wpa_s, prev_state);
866 /* Restore scan_req since we will try to scan again */
867 wpa_s->scan_req = scan_req;
868 wpa_supplicant_req_scan(wpa_s, 1, 0);
869 } else {
870 wpa_s->scan_for_connection = 0;
871 }
872 }
873
874
875 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
876 {
877 struct os_time remaining, new_int;
878 int cancelled;
879
880 cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
881 &remaining);
882
883 new_int.sec = sec;
884 new_int.usec = 0;
885 if (cancelled && os_time_before(&remaining, &new_int)) {
886 new_int.sec = remaining.sec;
887 new_int.usec = remaining.usec;
888 }
889
890 if (cancelled) {
891 eloop_register_timeout(new_int.sec, new_int.usec,
892 wpa_supplicant_scan, wpa_s, NULL);
893 }
894 wpa_s->scan_interval = sec;
895 }
896
897
898 /**
899 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
900 * @wpa_s: Pointer to wpa_supplicant data
901 * @sec: Number of seconds after which to scan
902 * @usec: Number of microseconds after which to scan
903 *
904 * This function is used to schedule a scan for neighboring access points after
905 * the specified time.
906 */
907 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
908 {
909 /* If there's at least one network that should be specifically scanned
910 * then don't cancel the scan and reschedule. Some drivers do
911 * background scanning which generates frequent scan results, and that
912 * causes the specific SSID scan to get continually pushed back and
913 * never happen, which causes hidden APs to never get probe-scanned.
914 */
915 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
916 wpa_s->conf->ap_scan == 1) {
917 struct wpa_ssid *ssid = wpa_s->conf->ssid;
918
919 while (ssid) {
920 if (!wpas_network_disabled(wpa_s, ssid) &&
921 ssid->scan_ssid)
922 break;
923 ssid = ssid->next;
924 }
925 if (ssid) {
926 wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
927 "ensure that specific SSID scans occur");
928 return;
929 }
930 }
931
932 wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
933 sec, usec);
934 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
935 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
936 }
937
938
939 /**
940 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
941 * @wpa_s: Pointer to wpa_supplicant data
942 * @sec: Number of seconds after which to scan
943 * @usec: Number of microseconds after which to scan
944 * Returns: 0 on success or -1 otherwise
945 *
946 * This function is used to schedule periodic scans for neighboring
947 * access points after the specified time.
948 */
949 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
950 int sec, int usec)
951 {
952 if (!wpa_s->sched_scan_supported)
953 return -1;
954
955 eloop_register_timeout(sec, usec,
956 wpa_supplicant_delayed_sched_scan_timeout,
957 wpa_s, NULL);
958
959 return 0;
960 }
961
962
963 /**
964 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
965 * @wpa_s: Pointer to wpa_supplicant data
966 * Returns: 0 is sched_scan was started or -1 otherwise
967 *
968 * This function is used to schedule periodic scans for neighboring
969 * access points repeating the scan continuously.
970 */
971 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
972 {
973 struct wpa_driver_scan_params params;
974 struct wpa_driver_scan_params *scan_params;
975 enum wpa_states prev_state;
976 struct wpa_ssid *ssid = NULL;
977 struct wpabuf *extra_ie = NULL;
978 int ret;
979 unsigned int max_sched_scan_ssids;
980 int wildcard = 0;
981 int need_ssids;
982
983 if (!wpa_s->sched_scan_supported)
984 return -1;
985
986 if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
987 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
988 else
989 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
990 if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
991 return -1;
992
993 if (wpa_s->sched_scanning) {
994 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
995 return 0;
996 }
997
998 need_ssids = 0;
999 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
1000 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
1001 /* Use wildcard SSID to find this network */
1002 wildcard = 1;
1003 } else if (!wpas_network_disabled(wpa_s, ssid) &&
1004 ssid->ssid_len)
1005 need_ssids++;
1006
1007 #ifdef CONFIG_WPS
1008 if (!wpas_network_disabled(wpa_s, ssid) &&
1009 ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
1010 /*
1011 * Normal scan is more reliable and faster for WPS
1012 * operations and since these are for short periods of
1013 * time, the benefit of trying to use sched_scan would
1014 * be limited.
1015 */
1016 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1017 "sched_scan for WPS");
1018 return -1;
1019 }
1020 #endif /* CONFIG_WPS */
1021 }
1022 if (wildcard)
1023 need_ssids++;
1024
1025 if (wpa_s->normal_scans < 3 &&
1026 (need_ssids <= wpa_s->max_scan_ssids ||
1027 wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
1028 /*
1029 * When normal scan can speed up operations, use that for the
1030 * first operations before starting the sched_scan to allow
1031 * user space sleep more. We do this only if the normal scan
1032 * has functionality that is suitable for this or if the
1033 * sched_scan does not have better support for multiple SSIDs.
1034 */
1035 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1036 "sched_scan for initial scans (normal_scans=%d)",
1037 wpa_s->normal_scans);
1038 return -1;
1039 }
1040
1041 os_memset(&params, 0, sizeof(params));
1042
1043 /* If we can't allocate space for the filters, we just don't filter */
1044 params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1045 sizeof(struct wpa_driver_scan_filter));
1046
1047 prev_state = wpa_s->wpa_state;
1048 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1049 wpa_s->wpa_state == WPA_INACTIVE)
1050 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1051
1052 if (wpa_s->autoscan_params != NULL) {
1053 scan_params = wpa_s->autoscan_params;
1054 goto scan;
1055 }
1056
1057 /* Find the starting point from which to continue scanning */
1058 ssid = wpa_s->conf->ssid;
1059 if (wpa_s->prev_sched_ssid) {
1060 while (ssid) {
1061 if (ssid == wpa_s->prev_sched_ssid) {
1062 ssid = ssid->next;
1063 break;
1064 }
1065 ssid = ssid->next;
1066 }
1067 }
1068
1069 if (!ssid || !wpa_s->prev_sched_ssid) {
1070 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1071 if (wpa_s->conf->sched_scan_interval)
1072 wpa_s->sched_scan_interval =
1073 wpa_s->conf->sched_scan_interval;
1074 if (wpa_s->sched_scan_interval == 0)
1075 wpa_s->sched_scan_interval = 10;
1076 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1077 wpa_s->first_sched_scan = 1;
1078 ssid = wpa_s->conf->ssid;
1079 wpa_s->prev_sched_ssid = ssid;
1080 }
1081
1082 if (wildcard) {
1083 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1084 params.num_ssids++;
1085 }
1086
1087 while (ssid) {
1088 if (wpas_network_disabled(wpa_s, ssid))
1089 goto next;
1090
1091 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1092 params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1093 wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1094 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1095 os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1096 ssid->ssid, ssid->ssid_len);
1097 params.filter_ssids[params.num_filter_ssids].ssid_len =
1098 ssid->ssid_len;
1099 params.num_filter_ssids++;
1100 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1101 {
1102 wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1103 "filter for sched_scan - drop filter");
1104 os_free(params.filter_ssids);
1105 params.filter_ssids = NULL;
1106 params.num_filter_ssids = 0;
1107 }
1108
1109 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1110 if (params.num_ssids == max_sched_scan_ssids)
1111 break; /* only room for broadcast SSID */
1112 wpa_dbg(wpa_s, MSG_DEBUG,
1113 "add to active scan ssid: %s",
1114 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1115 params.ssids[params.num_ssids].ssid =
1116 ssid->ssid;
1117 params.ssids[params.num_ssids].ssid_len =
1118 ssid->ssid_len;
1119 params.num_ssids++;
1120 if (params.num_ssids >= max_sched_scan_ssids) {
1121 wpa_s->prev_sched_ssid = ssid;
1122 do {
1123 ssid = ssid->next;
1124 } while (ssid &&
1125 (wpas_network_disabled(wpa_s, ssid) ||
1126 !ssid->scan_ssid));
1127 break;
1128 }
1129 }
1130
1131 next:
1132 wpa_s->prev_sched_ssid = ssid;
1133 ssid = ssid->next;
1134 }
1135
1136 if (params.num_filter_ssids == 0) {
1137 os_free(params.filter_ssids);
1138 params.filter_ssids = NULL;
1139 }
1140
1141 extra_ie = wpa_supplicant_extra_ies(wpa_s);
1142 if (extra_ie) {
1143 params.extra_ies = wpabuf_head(extra_ie);
1144 params.extra_ies_len = wpabuf_len(extra_ie);
1145 }
1146
1147 scan_params = &params;
1148
1149 scan:
1150 if (ssid || !wpa_s->first_sched_scan) {
1151 wpa_dbg(wpa_s, MSG_DEBUG,
1152 "Starting sched scan: interval %d timeout %d",
1153 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1154 } else {
1155 wpa_dbg(wpa_s, MSG_DEBUG,
1156 "Starting sched scan: interval %d (no timeout)",
1157 wpa_s->sched_scan_interval);
1158 }
1159
1160 wpa_setband_scan_freqs(wpa_s, scan_params);
1161
1162 ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1163 wpa_s->sched_scan_interval);
1164 wpabuf_free(extra_ie);
1165 os_free(params.filter_ssids);
1166 if (ret) {
1167 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1168 if (prev_state != wpa_s->wpa_state)
1169 wpa_supplicant_set_state(wpa_s, prev_state);
1170 return ret;
1171 }
1172
1173 /* If we have more SSIDs to scan, add a timeout so we scan them too */
1174 if (ssid || !wpa_s->first_sched_scan) {
1175 wpa_s->sched_scan_timed_out = 0;
1176 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1177 wpa_supplicant_sched_scan_timeout,
1178 wpa_s, NULL);
1179 wpa_s->first_sched_scan = 0;
1180 wpa_s->sched_scan_timeout /= 2;
1181 wpa_s->sched_scan_interval *= 2;
1182 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1183 wpa_s->sched_scan_interval = 10;
1184 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1185 }
1186 }
1187
1188 /* If there is no more ssids, start next time from the beginning */
1189 if (!ssid)
1190 wpa_s->prev_sched_ssid = NULL;
1191
1192 return 0;
1193 }
1194
1195
1196 /**
1197 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1198 * @wpa_s: Pointer to wpa_supplicant data
1199 *
1200 * This function is used to cancel a scan request scheduled with
1201 * wpa_supplicant_req_scan().
1202 */
1203 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1204 {
1205 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1206 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1207 wpas_p2p_continue_after_scan(wpa_s);
1208 }
1209
1210
1211 /**
1212 * wpa_supplicant_cancel_delayed_sched_scan - Stop a delayed scheduled scan
1213 * @wpa_s: Pointer to wpa_supplicant data
1214 *
1215 * This function is used to stop a delayed scheduled scan.
1216 */
1217 void wpa_supplicant_cancel_delayed_sched_scan(struct wpa_supplicant *wpa_s)
1218 {
1219 if (!wpa_s->sched_scan_supported)
1220 return;
1221
1222 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling delayed sched scan");
1223 eloop_cancel_timeout(wpa_supplicant_delayed_sched_scan_timeout,
1224 wpa_s, NULL);
1225 }
1226
1227
1228 /**
1229 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1230 * @wpa_s: Pointer to wpa_supplicant data
1231 *
1232 * This function is used to stop a periodic scheduled scan.
1233 */
1234 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1235 {
1236 if (!wpa_s->sched_scanning)
1237 return;
1238
1239 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1240 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1241 wpa_supplicant_stop_sched_scan(wpa_s);
1242 }
1243
1244
1245 /**
1246 * wpa_supplicant_notify_scanning - Indicate possible scan state change
1247 * @wpa_s: Pointer to wpa_supplicant data
1248 * @scanning: Whether scanning is currently in progress
1249 *
1250 * This function is to generate scanning notifycations. It is called whenever
1251 * there may have been a change in scanning (scan started, completed, stopped).
1252 * wpas_notify_scanning() is called whenever the scanning state changed from the
1253 * previously notified state.
1254 */
1255 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1256 int scanning)
1257 {
1258 if (wpa_s->scanning != scanning) {
1259 wpa_s->scanning = scanning;
1260 wpas_notify_scanning(wpa_s);
1261 }
1262 }
1263
1264
1265 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1266 {
1267 int rate = 0;
1268 const u8 *ie;
1269 int i;
1270
1271 ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1272 for (i = 0; ie && i < ie[1]; i++) {
1273 if ((ie[i + 2] & 0x7f) > rate)
1274 rate = ie[i + 2] & 0x7f;
1275 }
1276
1277 ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1278 for (i = 0; ie && i < ie[1]; i++) {
1279 if ((ie[i + 2] & 0x7f) > rate)
1280 rate = ie[i + 2] & 0x7f;
1281 }
1282
1283 return rate;
1284 }
1285
1286
1287 /**
1288 * wpa_scan_get_ie - Fetch a specified information element from a scan result
1289 * @res: Scan result entry
1290 * @ie: Information element identitifier (WLAN_EID_*)
1291 * Returns: Pointer to the information element (id field) or %NULL if not found
1292 *
1293 * This function returns the first matching information element in the scan
1294 * result.
1295 */
1296 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1297 {
1298 const u8 *end, *pos;
1299
1300 pos = (const u8 *) (res + 1);
1301 end = pos + res->ie_len;
1302
1303 while (pos + 1 < end) {
1304 if (pos + 2 + pos[1] > end)
1305 break;
1306 if (pos[0] == ie)
1307 return pos;
1308 pos += 2 + pos[1];
1309 }
1310
1311 return NULL;
1312 }
1313
1314
1315 /**
1316 * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1317 * @res: Scan result entry
1318 * @vendor_type: Vendor type (four octets starting the IE payload)
1319 * Returns: Pointer to the information element (id field) or %NULL if not found
1320 *
1321 * This function returns the first matching information element in the scan
1322 * result.
1323 */
1324 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1325 u32 vendor_type)
1326 {
1327 const u8 *end, *pos;
1328
1329 pos = (const u8 *) (res + 1);
1330 end = pos + res->ie_len;
1331
1332 while (pos + 1 < end) {
1333 if (pos + 2 + pos[1] > end)
1334 break;
1335 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1336 vendor_type == WPA_GET_BE32(&pos[2]))
1337 return pos;
1338 pos += 2 + pos[1];
1339 }
1340
1341 return NULL;
1342 }
1343
1344
1345 /**
1346 * wpa_scan_get_vendor_ie_beacon - Fetch vendor information from a scan result
1347 * @res: Scan result entry
1348 * @vendor_type: Vendor type (four octets starting the IE payload)
1349 * Returns: Pointer to the information element (id field) or %NULL if not found
1350 *
1351 * This function returns the first matching information element in the scan
1352 * result.
1353 *
1354 * This function is like wpa_scan_get_vendor_ie(), but uses IE buffer only
1355 * from Beacon frames instead of either Beacon or Probe Response frames.
1356 */
1357 const u8 * wpa_scan_get_vendor_ie_beacon(const struct wpa_scan_res *res,
1358 u32 vendor_type)
1359 {
1360 const u8 *end, *pos;
1361
1362 if (res->beacon_ie_len == 0)
1363 return NULL;
1364
1365 pos = (const u8 *) (res + 1);
1366 pos += res->ie_len;
1367 end = pos + res->beacon_ie_len;
1368
1369 while (pos + 1 < end) {
1370 if (pos + 2 + pos[1] > end)
1371 break;
1372 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1373 vendor_type == WPA_GET_BE32(&pos[2]))
1374 return pos;
1375 pos += 2 + pos[1];
1376 }
1377
1378 return NULL;
1379 }
1380
1381
1382 /**
1383 * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1384 * @res: Scan result entry
1385 * @vendor_type: Vendor type (four octets starting the IE payload)
1386 * Returns: Pointer to the information element payload or %NULL if not found
1387 *
1388 * This function returns concatenated payload of possibly fragmented vendor
1389 * specific information elements in the scan result. The caller is responsible
1390 * for freeing the returned buffer.
1391 */
1392 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1393 u32 vendor_type)
1394 {
1395 struct wpabuf *buf;
1396 const u8 *end, *pos;
1397
1398 buf = wpabuf_alloc(res->ie_len);
1399 if (buf == NULL)
1400 return NULL;
1401
1402 pos = (const u8 *) (res + 1);
1403 end = pos + res->ie_len;
1404
1405 while (pos + 1 < end) {
1406 if (pos + 2 + pos[1] > end)
1407 break;
1408 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1409 vendor_type == WPA_GET_BE32(&pos[2]))
1410 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1411 pos += 2 + pos[1];
1412 }
1413
1414 if (wpabuf_len(buf) == 0) {
1415 wpabuf_free(buf);
1416 buf = NULL;
1417 }
1418
1419 return buf;
1420 }
1421
1422
1423 /*
1424 * Channels with a great SNR can operate at full rate. What is a great SNR?
1425 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1426 * rule of thumb is that any SNR above 20 is good." This one
1427 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1428 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1429 * conservative value.
1430 */
1431 #define GREAT_SNR 30
1432
1433 /* Compare function for sorting scan results. Return >0 if @b is considered
1434 * better. */
1435 static int wpa_scan_result_compar(const void *a, const void *b)
1436 {
1437 #define IS_5GHZ(n) (n > 4000)
1438 #define MIN(a,b) a < b ? a : b
1439 struct wpa_scan_res **_wa = (void *) a;
1440 struct wpa_scan_res **_wb = (void *) b;
1441 struct wpa_scan_res *wa = *_wa;
1442 struct wpa_scan_res *wb = *_wb;
1443 int wpa_a, wpa_b, maxrate_a, maxrate_b;
1444 int snr_a, snr_b;
1445
1446 /* WPA/WPA2 support preferred */
1447 wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1448 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1449 wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1450 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1451
1452 if (wpa_b && !wpa_a)
1453 return 1;
1454 if (!wpa_b && wpa_a)
1455 return -1;
1456
1457 /* privacy support preferred */
1458 if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1459 (wb->caps & IEEE80211_CAP_PRIVACY))
1460 return 1;
1461 if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1462 (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1463 return -1;
1464
1465 if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1466 !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1467 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1468 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1469 } else {
1470 /* Not suitable information to calculate SNR, so use level */
1471 snr_a = wa->level;
1472 snr_b = wb->level;
1473 }
1474
1475 /* best/max rate preferred if SNR close enough */
1476 if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1477 (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1478 maxrate_a = wpa_scan_get_max_rate(wa);
1479 maxrate_b = wpa_scan_get_max_rate(wb);
1480 if (maxrate_a != maxrate_b)
1481 return maxrate_b - maxrate_a;
1482 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1483 return IS_5GHZ(wa->freq) ? -1 : 1;
1484 }
1485
1486 /* use freq for channel preference */
1487
1488 /* all things being equal, use SNR; if SNRs are
1489 * identical, use quality values since some drivers may only report
1490 * that value and leave the signal level zero */
1491 if (snr_b == snr_a)
1492 return wb->qual - wa->qual;
1493 return snr_b - snr_a;
1494 #undef MIN
1495 #undef IS_5GHZ
1496 }
1497
1498
1499 #ifdef CONFIG_WPS
1500 /* Compare function for sorting scan results when searching a WPS AP for
1501 * provisioning. Return >0 if @b is considered better. */
1502 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1503 {
1504 struct wpa_scan_res **_wa = (void *) a;
1505 struct wpa_scan_res **_wb = (void *) b;
1506 struct wpa_scan_res *wa = *_wa;
1507 struct wpa_scan_res *wb = *_wb;
1508 int uses_wps_a, uses_wps_b;
1509 struct wpabuf *wps_a, *wps_b;
1510 int res;
1511
1512 /* Optimization - check WPS IE existence before allocated memory and
1513 * doing full reassembly. */
1514 uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1515 uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1516 if (uses_wps_a && !uses_wps_b)
1517 return -1;
1518 if (!uses_wps_a && uses_wps_b)
1519 return 1;
1520
1521 if (uses_wps_a && uses_wps_b) {
1522 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1523 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1524 res = wps_ap_priority_compar(wps_a, wps_b);
1525 wpabuf_free(wps_a);
1526 wpabuf_free(wps_b);
1527 if (res)
1528 return res;
1529 }
1530
1531 /*
1532 * Do not use current AP security policy as a sorting criteria during
1533 * WPS provisioning step since the AP may get reconfigured at the
1534 * completion of provisioning.
1535 */
1536
1537 /* all things being equal, use signal level; if signal levels are
1538 * identical, use quality values since some drivers may only report
1539 * that value and leave the signal level zero */
1540 if (wb->level == wa->level)
1541 return wb->qual - wa->qual;
1542 return wb->level - wa->level;
1543 }
1544 #endif /* CONFIG_WPS */
1545
1546
1547 static void dump_scan_res(struct wpa_scan_results *scan_res)
1548 {
1549 #ifndef CONFIG_NO_STDOUT_DEBUG
1550 size_t i;
1551
1552 if (scan_res->res == NULL || scan_res->num == 0)
1553 return;
1554
1555 wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1556
1557 for (i = 0; i < scan_res->num; i++) {
1558 struct wpa_scan_res *r = scan_res->res[i];
1559 u8 *pos;
1560 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1561 == WPA_SCAN_LEVEL_DBM) {
1562 int snr = r->level - r->noise;
1563 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1564 "noise=%d level=%d snr=%d%s flags=0x%x "
1565 "age=%u",
1566 MAC2STR(r->bssid), r->freq, r->qual,
1567 r->noise, r->level, snr,
1568 snr >= GREAT_SNR ? "*" : "", r->flags,
1569 r->age);
1570 } else {
1571 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1572 "noise=%d level=%d flags=0x%x age=%u",
1573 MAC2STR(r->bssid), r->freq, r->qual,
1574 r->noise, r->level, r->flags, r->age);
1575 }
1576 pos = (u8 *) (r + 1);
1577 if (r->ie_len)
1578 wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1579 pos += r->ie_len;
1580 if (r->beacon_ie_len)
1581 wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1582 pos, r->beacon_ie_len);
1583 }
1584 #endif /* CONFIG_NO_STDOUT_DEBUG */
1585 }
1586
1587
1588 /**
1589 * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1590 * @wpa_s: Pointer to wpa_supplicant data
1591 * @bssid: BSSID to check
1592 * Returns: 0 if the BSSID is filtered or 1 if not
1593 *
1594 * This function is used to filter out specific BSSIDs from scan reslts mainly
1595 * for testing purposes (SET bssid_filter ctrl_iface command).
1596 */
1597 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1598 const u8 *bssid)
1599 {
1600 size_t i;
1601
1602 if (wpa_s->bssid_filter == NULL)
1603 return 1;
1604
1605 for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1606 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1607 ETH_ALEN) == 0)
1608 return 1;
1609 }
1610
1611 return 0;
1612 }
1613
1614
1615 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1616 struct wpa_scan_results *res)
1617 {
1618 size_t i, j;
1619
1620 if (wpa_s->bssid_filter == NULL)
1621 return;
1622
1623 for (i = 0, j = 0; i < res->num; i++) {
1624 if (wpa_supplicant_filter_bssid_match(wpa_s,
1625 res->res[i]->bssid)) {
1626 res->res[j++] = res->res[i];
1627 } else {
1628 os_free(res->res[i]);
1629 res->res[i] = NULL;
1630 }
1631 }
1632
1633 if (res->num != j) {
1634 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1635 (int) (res->num - j));
1636 res->num = j;
1637 }
1638 }
1639
1640
1641 /**
1642 * wpa_supplicant_get_scan_results - Get scan results
1643 * @wpa_s: Pointer to wpa_supplicant data
1644 * @info: Information about what was scanned or %NULL if not available
1645 * @new_scan: Whether a new scan was performed
1646 * Returns: Scan results, %NULL on failure
1647 *
1648 * This function request the current scan results from the driver and updates
1649 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1650 * results with wpa_scan_results_free().
1651 */
1652 struct wpa_scan_results *
1653 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1654 struct scan_info *info, int new_scan)
1655 {
1656 struct wpa_scan_results *scan_res;
1657 size_t i;
1658 int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1659
1660 scan_res = wpa_drv_get_scan_results2(wpa_s);
1661 if (scan_res == NULL) {
1662 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1663 return NULL;
1664 }
1665 if (scan_res->fetch_time.sec == 0) {
1666 /*
1667 * Make sure we have a valid timestamp if the driver wrapper
1668 * does not set this.
1669 */
1670 os_get_time(&scan_res->fetch_time);
1671 }
1672 filter_scan_res(wpa_s, scan_res);
1673
1674 #ifdef CONFIG_WPS
1675 if (wpas_wps_in_progress(wpa_s)) {
1676 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1677 "provisioning rules");
1678 compar = wpa_scan_result_wps_compar;
1679 }
1680 #endif /* CONFIG_WPS */
1681
1682 qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1683 compar);
1684 dump_scan_res(scan_res);
1685
1686 wpa_bss_update_start(wpa_s);
1687 for (i = 0; i < scan_res->num; i++)
1688 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1689 &scan_res->fetch_time);
1690 wpa_bss_update_end(wpa_s, info, new_scan);
1691
1692 return scan_res;
1693 }
1694
1695
1696 /**
1697 * wpa_supplicant_update_scan_results - Update scan results from the driver
1698 * @wpa_s: Pointer to wpa_supplicant data
1699 * Returns: 0 on success, -1 on failure
1700 *
1701 * This function updates the BSS table within wpa_supplicant based on the
1702 * currently available scan results from the driver without requesting a new
1703 * scan. This is used in cases where the driver indicates an association
1704 * (including roaming within ESS) and wpa_supplicant does not yet have the
1705 * needed information to complete the connection (e.g., to perform validation
1706 * steps in 4-way handshake).
1707 */
1708 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1709 {
1710 struct wpa_scan_results *scan_res;
1711 scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1712 if (scan_res == NULL)
1713 return -1;
1714 wpa_scan_results_free(scan_res);
1715
1716 return 0;
1717 }
1718
1719
1720 /**
1721 * scan_only_handler - Reports scan results
1722 */
1723 void scan_only_handler(struct wpa_supplicant *wpa_s,
1724 struct wpa_scan_results *scan_res)
1725 {
1726 wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1727 wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1728 wpas_notify_scan_results(wpa_s);
1729 wpas_notify_scan_done(wpa_s, 1);
1730 }
1731
1732
1733 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1734 {
1735 return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1736 }
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