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
wpa_supplicant_gen_assoc_event(struct wpa_supplicant * wpa_s)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
wpas_wps_in_use(struct wpa_supplicant * wpa_s,enum wps_request_type * req_type)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 */
wpa_supplicant_enabled_networks(struct wpa_supplicant * wpa_s)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
wpa_supplicant_assoc_try(struct wpa_supplicant * wpa_s,struct wpa_ssid * ssid)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
int_array_len(const int * a)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
int_array_concat(int ** res,const int * a)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
freq_cmp(const void * a,const void * b)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
int_array_sort_unique(int * a)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 */
wpa_supplicant_trigger_scan(struct wpa_supplicant * wpa_s,struct wpa_driver_scan_params * params)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
wpa_supplicant_delayed_sched_scan_timeout(void * eloop_ctx,void * timeout_ctx)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
wpa_supplicant_sched_scan_timeout(void * eloop_ctx,void * timeout_ctx)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
wpa_supplicant_start_sched_scan(struct wpa_supplicant * wpa_s,struct wpa_driver_scan_params * params,int interval)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
278 return ret;
279 }
280
281
wpa_supplicant_stop_sched_scan(struct wpa_supplicant * wpa_s)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 *
wpa_supplicant_build_filter_ssids(struct wpa_config * conf,size_t * num_ssids)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
wpa_supplicant_optimize_freqs(struct wpa_supplicant * wpa_s,struct wpa_driver_scan_params * params)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(¶ms->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
wpas_add_interworking_elements(struct wpa_supplicant * wpa_s,struct wpabuf * buf)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
wpa_supplicant_extra_ies(struct wpa_supplicant * wpa_s)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 */
non_p2p_network_enabled(struct wpa_supplicant * wpa_s)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
get_mode(struct hostapd_hw_modes * modes,u16 num_modes,enum hostapd_hw_mode mode)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
wpa_setband_scan_freqs_list(struct wpa_supplicant * wpa_s,enum hostapd_hw_mode band,struct wpa_driver_scan_params * params)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
wpa_setband_scan_freqs(struct wpa_supplicant * wpa_s,struct wpa_driver_scan_params * params)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
wpa_supplicant_scan(void * eloop_ctx,void * timeout_ctx)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 #ifdef ANDROID
570 if (wpa_s->scanning) {
571 /* If we are already in scanning state, we shall ignore this new scan request*/
572 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - already scanning");
573 return;
574 }
575 #endif
576 if (!wpa_supplicant_enabled_networks(wpa_s) &&
577 wpa_s->scan_req == NORMAL_SCAN_REQ) {
578 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
579 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
580 wpas_p2p_continue_after_scan(wpa_s);
581 return;
582 }
583
584 if (wpa_s->conf->ap_scan != 0 &&
585 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
586 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
587 "overriding ap_scan configuration");
588 wpa_s->conf->ap_scan = 0;
589 wpas_notify_ap_scan_changed(wpa_s);
590 }
591
592 if (wpa_s->conf->ap_scan == 0) {
593 wpa_supplicant_gen_assoc_event(wpa_s);
594 return;
595 }
596
597 #ifdef CONFIG_P2P
598 if (wpas_p2p_in_progress(wpa_s) || wpas_wpa_is_in_progress(wpa_s)) {
599 if (wpa_s->sta_scan_pending &&
600 wpas_p2p_in_progress(wpa_s) == 2 &&
601 wpa_s->global->p2p_cb_on_scan_complete) {
602 wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
603 "mode scan during P2P search");
604 } else {
605 wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
606 "while P2P operation is in progress");
607 wpa_s->sta_scan_pending = 1;
608 wpa_supplicant_req_scan(wpa_s, 5, 0);
609 return;
610 }
611 }
612 #endif /* CONFIG_P2P */
613
614 if (wpa_s->conf->ap_scan == 2)
615 max_ssids = 1;
616 else {
617 max_ssids = wpa_s->max_scan_ssids;
618 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
619 max_ssids = WPAS_MAX_SCAN_SSIDS;
620 }
621
622 scan_req = wpa_s->scan_req;
623 wpa_s->scan_req = NORMAL_SCAN_REQ;
624
625 os_memset(¶ms, 0, sizeof(params));
626
627 prev_state = wpa_s->wpa_state;
628 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
629 wpa_s->wpa_state == WPA_INACTIVE)
630 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
631
632 /*
633 * If autoscan has set its own scanning parameters
634 */
635 if (wpa_s->autoscan_params != NULL) {
636 scan_params = wpa_s->autoscan_params;
637 goto scan;
638 }
639
640 if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
641 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
642 if (ssid == wpa_s->connect_without_scan)
643 break;
644 }
645 wpa_s->connect_without_scan = NULL;
646 if (ssid) {
647 wpa_printf(MSG_DEBUG, "Start a pre-selected network "
648 "without scan step");
649 wpa_supplicant_associate(wpa_s, NULL, ssid);
650 return;
651 }
652 }
653
654 #ifdef CONFIG_P2P
655 if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
656 wpa_s->go_params) {
657 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
658 "P2P group formation");
659 params.ssids[0].ssid = wpa_s->go_params->ssid;
660 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
661 params.num_ssids = 1;
662 goto ssid_list_set;
663 }
664 #endif /* CONFIG_P2P */
665
666 /* Find the starting point from which to continue scanning */
667 ssid = wpa_s->conf->ssid;
668 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
669 while (ssid) {
670 if (ssid == wpa_s->prev_scan_ssid) {
671 ssid = ssid->next;
672 break;
673 }
674 ssid = ssid->next;
675 }
676 }
677
678 if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
679 wpa_s->connect_without_scan = NULL;
680 wpa_s->prev_scan_wildcard = 0;
681 wpa_supplicant_assoc_try(wpa_s, ssid);
682 return;
683 #ifndef ANDROID
684 } else if (wpa_s->conf->ap_scan == 2) {
685 /*
686 * User-initiated scan request in ap_scan == 2; scan with
687 * wildcard SSID.
688 */
689 ssid = NULL;
690 #endif
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(¶ms.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, ¶ms);
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, ¶ms);
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(¶ms.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, ¶ms.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 = ¶ms;
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
wpa_supplicant_update_scan_int(struct wpa_supplicant * wpa_s,int sec)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 eloop_register_timeout(new_int.sec, new_int.usec, wpa_supplicant_scan,
891 wpa_s, NULL);
892 wpa_s->scan_interval = sec;
893 }
894
895
896 /**
897 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
898 * @wpa_s: Pointer to wpa_supplicant data
899 * @sec: Number of seconds after which to scan
900 * @usec: Number of microseconds after which to scan
901 *
902 * This function is used to schedule a scan for neighboring access points after
903 * the specified time.
904 */
wpa_supplicant_req_scan(struct wpa_supplicant * wpa_s,int sec,int usec)905 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
906 {
907 #ifndef ANDROID
908 /* If there's at least one network that should be specifically scanned
909 * then don't cancel the scan and reschedule. Some drivers do
910 * background scanning which generates frequent scan results, and that
911 * causes the specific SSID scan to get continually pushed back and
912 * never happen, which causes hidden APs to never get probe-scanned.
913 */
914 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
915 wpa_s->conf->ap_scan == 1) {
916 struct wpa_ssid *ssid = wpa_s->conf->ssid;
917
918 while (ssid) {
919 if (!wpas_network_disabled(wpa_s, ssid) &&
920 ssid->scan_ssid)
921 break;
922 ssid = ssid->next;
923 }
924 if (ssid) {
925 wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
926 "ensure that specific SSID scans occur");
927 return;
928 }
929 }
930 #endif
931 wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
932 sec, usec);
933 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
934 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
935 }
936
937
938 /**
939 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
940 * @wpa_s: Pointer to wpa_supplicant data
941 * @sec: Number of seconds after which to scan
942 * @usec: Number of microseconds after which to scan
943 * Returns: 0 on success or -1 otherwise
944 *
945 * This function is used to schedule periodic scans for neighboring
946 * access points after the specified time.
947 */
wpa_supplicant_delayed_sched_scan(struct wpa_supplicant * wpa_s,int sec,int usec)948 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
949 int sec, int usec)
950 {
951 if (!wpa_s->sched_scan_supported)
952 return -1;
953
954 eloop_register_timeout(sec, usec,
955 wpa_supplicant_delayed_sched_scan_timeout,
956 wpa_s, NULL);
957
958 return 0;
959 }
960
961
962 /**
963 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
964 * @wpa_s: Pointer to wpa_supplicant data
965 * Returns: 0 is sched_scan was started or -1 otherwise
966 *
967 * This function is used to schedule periodic scans for neighboring
968 * access points repeating the scan continuously.
969 */
wpa_supplicant_req_sched_scan(struct wpa_supplicant * wpa_s)970 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
971 {
972 struct wpa_driver_scan_params params;
973 struct wpa_driver_scan_params *scan_params;
974 enum wpa_states prev_state;
975 struct wpa_ssid *ssid = NULL;
976 struct wpabuf *extra_ie = NULL;
977 int ret;
978 unsigned int max_sched_scan_ssids;
979 int wildcard = 0;
980 int need_ssids;
981
982 if (!wpa_s->sched_scan_supported)
983 return -1;
984
985 if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
986 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
987 else
988 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
989 if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
990 return -1;
991
992 if (wpa_s->sched_scanning) {
993 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
994 return 0;
995 }
996
997 need_ssids = 0;
998 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
999 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
1000 /* Use wildcard SSID to find this network */
1001 wildcard = 1;
1002 } else if (!wpas_network_disabled(wpa_s, ssid) &&
1003 ssid->ssid_len)
1004 need_ssids++;
1005
1006 #ifdef CONFIG_WPS
1007 if (!wpas_network_disabled(wpa_s, ssid) &&
1008 ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
1009 /*
1010 * Normal scan is more reliable and faster for WPS
1011 * operations and since these are for short periods of
1012 * time, the benefit of trying to use sched_scan would
1013 * be limited.
1014 */
1015 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1016 "sched_scan for WPS");
1017 return -1;
1018 }
1019 #endif /* CONFIG_WPS */
1020 }
1021 if (wildcard)
1022 need_ssids++;
1023
1024 if (wpa_s->normal_scans < 3 &&
1025 (need_ssids <= wpa_s->max_scan_ssids ||
1026 wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
1027 /*
1028 * When normal scan can speed up operations, use that for the
1029 * first operations before starting the sched_scan to allow
1030 * user space sleep more. We do this only if the normal scan
1031 * has functionality that is suitable for this or if the
1032 * sched_scan does not have better support for multiple SSIDs.
1033 */
1034 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
1035 "sched_scan for initial scans (normal_scans=%d)",
1036 wpa_s->normal_scans);
1037 return -1;
1038 }
1039
1040 os_memset(¶ms, 0, sizeof(params));
1041
1042 /* If we can't allocate space for the filters, we just don't filter */
1043 params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1044 sizeof(struct wpa_driver_scan_filter));
1045
1046 prev_state = wpa_s->wpa_state;
1047 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1048 wpa_s->wpa_state == WPA_INACTIVE)
1049 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1050
1051 if (wpa_s->autoscan_params != NULL) {
1052 scan_params = wpa_s->autoscan_params;
1053 goto scan;
1054 }
1055
1056 /* Find the starting point from which to continue scanning */
1057 ssid = wpa_s->conf->ssid;
1058 if (wpa_s->prev_sched_ssid) {
1059 while (ssid) {
1060 if (ssid == wpa_s->prev_sched_ssid) {
1061 ssid = ssid->next;
1062 break;
1063 }
1064 ssid = ssid->next;
1065 }
1066 }
1067
1068 if (!ssid || !wpa_s->prev_sched_ssid) {
1069 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1070 if (wpa_s->conf->sched_scan_interval)
1071 wpa_s->sched_scan_interval =
1072 wpa_s->conf->sched_scan_interval;
1073 if (wpa_s->sched_scan_interval == 0)
1074 wpa_s->sched_scan_interval = 10;
1075 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1076 wpa_s->first_sched_scan = 1;
1077 ssid = wpa_s->conf->ssid;
1078 wpa_s->prev_sched_ssid = ssid;
1079 }
1080
1081 if (wildcard) {
1082 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1083 params.num_ssids++;
1084 }
1085
1086 while (ssid) {
1087 if (wpas_network_disabled(wpa_s, ssid))
1088 goto next;
1089
1090 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1091 params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1092 wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1093 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1094 os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1095 ssid->ssid, ssid->ssid_len);
1096 params.filter_ssids[params.num_filter_ssids].ssid_len =
1097 ssid->ssid_len;
1098 params.num_filter_ssids++;
1099 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1100 {
1101 wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1102 "filter for sched_scan - drop filter");
1103 os_free(params.filter_ssids);
1104 params.filter_ssids = NULL;
1105 params.num_filter_ssids = 0;
1106 }
1107
1108 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1109 if (params.num_ssids == max_sched_scan_ssids)
1110 break; /* only room for broadcast SSID */
1111 wpa_dbg(wpa_s, MSG_DEBUG,
1112 "add to active scan ssid: %s",
1113 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1114 params.ssids[params.num_ssids].ssid =
1115 ssid->ssid;
1116 params.ssids[params.num_ssids].ssid_len =
1117 ssid->ssid_len;
1118 params.num_ssids++;
1119 if (params.num_ssids >= max_sched_scan_ssids) {
1120 wpa_s->prev_sched_ssid = ssid;
1121 do {
1122 ssid = ssid->next;
1123 } while (ssid &&
1124 (wpas_network_disabled(wpa_s, ssid) ||
1125 !ssid->scan_ssid));
1126 break;
1127 }
1128 }
1129
1130 next:
1131 wpa_s->prev_sched_ssid = ssid;
1132 ssid = ssid->next;
1133 }
1134
1135 if (params.num_filter_ssids == 0) {
1136 os_free(params.filter_ssids);
1137 params.filter_ssids = NULL;
1138 }
1139
1140 extra_ie = wpa_supplicant_extra_ies(wpa_s);
1141 if (extra_ie) {
1142 params.extra_ies = wpabuf_head(extra_ie);
1143 params.extra_ies_len = wpabuf_len(extra_ie);
1144 }
1145
1146 scan_params = ¶ms;
1147
1148 scan:
1149 if (ssid || !wpa_s->first_sched_scan) {
1150 wpa_dbg(wpa_s, MSG_DEBUG,
1151 "Starting sched scan: interval %d timeout %d",
1152 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1153 } else {
1154 wpa_dbg(wpa_s, MSG_DEBUG,
1155 "Starting sched scan: interval %d (no timeout)",
1156 wpa_s->sched_scan_interval);
1157 }
1158
1159 wpa_setband_scan_freqs(wpa_s, scan_params);
1160
1161 ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1162 wpa_s->sched_scan_interval);
1163 wpabuf_free(extra_ie);
1164 os_free(params.filter_ssids);
1165 if (ret) {
1166 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1167 if (prev_state != wpa_s->wpa_state)
1168 wpa_supplicant_set_state(wpa_s, prev_state);
1169 return ret;
1170 }
1171
1172 /* If we have more SSIDs to scan, add a timeout so we scan them too */
1173 if (ssid || !wpa_s->first_sched_scan) {
1174 wpa_s->sched_scan_timed_out = 0;
1175 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1176 wpa_supplicant_sched_scan_timeout,
1177 wpa_s, NULL);
1178 wpa_s->first_sched_scan = 0;
1179 wpa_s->sched_scan_timeout /= 2;
1180 wpa_s->sched_scan_interval *= 2;
1181 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1182 wpa_s->sched_scan_interval = 10;
1183 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1184 }
1185 }
1186
1187 /* If there is no more ssids, start next time from the beginning */
1188 if (!ssid)
1189 wpa_s->prev_sched_ssid = NULL;
1190
1191 return 0;
1192 }
1193
1194
1195 /**
1196 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1197 * @wpa_s: Pointer to wpa_supplicant data
1198 *
1199 * This function is used to cancel a scan request scheduled with
1200 * wpa_supplicant_req_scan().
1201 */
wpa_supplicant_cancel_scan(struct wpa_supplicant * wpa_s)1202 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1203 {
1204 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1205 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1206 wpas_p2p_continue_after_scan(wpa_s);
1207 #ifdef ANDROID
1208 wpa_supplicant_notify_scanning(wpa_s, 0);
1209 #endif
1210 }
1211
1212
1213 /**
1214 * wpa_supplicant_cancel_delayed_sched_scan - Stop a delayed scheduled scan
1215 * @wpa_s: Pointer to wpa_supplicant data
1216 *
1217 * This function is used to stop a delayed scheduled scan.
1218 */
wpa_supplicant_cancel_delayed_sched_scan(struct wpa_supplicant * wpa_s)1219 void wpa_supplicant_cancel_delayed_sched_scan(struct wpa_supplicant *wpa_s)
1220 {
1221 if (!wpa_s->sched_scan_supported)
1222 return;
1223
1224 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling delayed sched scan");
1225 eloop_cancel_timeout(wpa_supplicant_delayed_sched_scan_timeout,
1226 wpa_s, NULL);
1227 }
1228
1229
1230 /**
1231 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1232 * @wpa_s: Pointer to wpa_supplicant data
1233 *
1234 * This function is used to stop a periodic scheduled scan.
1235 */
wpa_supplicant_cancel_sched_scan(struct wpa_supplicant * wpa_s)1236 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1237 {
1238 if (!wpa_s->sched_scanning)
1239 return;
1240
1241 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1242 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1243 wpa_supplicant_stop_sched_scan(wpa_s);
1244 }
1245
1246
1247 /**
1248 * wpa_supplicant_notify_scanning - Indicate possible scan state change
1249 * @wpa_s: Pointer to wpa_supplicant data
1250 * @scanning: Whether scanning is currently in progress
1251 *
1252 * This function is to generate scanning notifycations. It is called whenever
1253 * there may have been a change in scanning (scan started, completed, stopped).
1254 * wpas_notify_scanning() is called whenever the scanning state changed from the
1255 * previously notified state.
1256 */
wpa_supplicant_notify_scanning(struct wpa_supplicant * wpa_s,int scanning)1257 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1258 int scanning)
1259 {
1260 if (wpa_s->scanning != scanning) {
1261 wpa_s->scanning = scanning;
1262 wpas_notify_scanning(wpa_s);
1263 }
1264 }
1265
1266
wpa_scan_get_max_rate(const struct wpa_scan_res * res)1267 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1268 {
1269 int rate = 0;
1270 const u8 *ie;
1271 int i;
1272
1273 ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1274 for (i = 0; ie && i < ie[1]; i++) {
1275 if ((ie[i + 2] & 0x7f) > rate)
1276 rate = ie[i + 2] & 0x7f;
1277 }
1278
1279 ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1280 for (i = 0; ie && i < ie[1]; i++) {
1281 if ((ie[i + 2] & 0x7f) > rate)
1282 rate = ie[i + 2] & 0x7f;
1283 }
1284
1285 return rate;
1286 }
1287
1288
1289 /**
1290 * wpa_scan_get_ie - Fetch a specified information element from a scan result
1291 * @res: Scan result entry
1292 * @ie: Information element identitifier (WLAN_EID_*)
1293 * Returns: Pointer to the information element (id field) or %NULL if not found
1294 *
1295 * This function returns the first matching information element in the scan
1296 * result.
1297 */
wpa_scan_get_ie(const struct wpa_scan_res * res,u8 ie)1298 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1299 {
1300 const u8 *end, *pos;
1301
1302 pos = (const u8 *) (res + 1);
1303 end = pos + res->ie_len;
1304
1305 while (pos + 1 < end) {
1306 if (pos + 2 + pos[1] > end)
1307 break;
1308 if (pos[0] == ie)
1309 return pos;
1310 pos += 2 + pos[1];
1311 }
1312
1313 return NULL;
1314 }
1315
1316
1317 /**
1318 * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1319 * @res: Scan result entry
1320 * @vendor_type: Vendor type (four octets starting the IE payload)
1321 * Returns: Pointer to the information element (id field) or %NULL if not found
1322 *
1323 * This function returns the first matching information element in the scan
1324 * result.
1325 */
wpa_scan_get_vendor_ie(const struct wpa_scan_res * res,u32 vendor_type)1326 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1327 u32 vendor_type)
1328 {
1329 const u8 *end, *pos;
1330
1331 pos = (const u8 *) (res + 1);
1332 end = pos + res->ie_len;
1333
1334 while (pos + 1 < end) {
1335 if (pos + 2 + pos[1] > end)
1336 break;
1337 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1338 vendor_type == WPA_GET_BE32(&pos[2]))
1339 return pos;
1340 pos += 2 + pos[1];
1341 }
1342
1343 return NULL;
1344 }
1345
1346
1347 /**
1348 * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1349 * @res: Scan result entry
1350 * @vendor_type: Vendor type (four octets starting the IE payload)
1351 * Returns: Pointer to the information element payload or %NULL if not found
1352 *
1353 * This function returns concatenated payload of possibly fragmented vendor
1354 * specific information elements in the scan result. The caller is responsible
1355 * for freeing the returned buffer.
1356 */
wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res * res,u32 vendor_type)1357 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1358 u32 vendor_type)
1359 {
1360 struct wpabuf *buf;
1361 const u8 *end, *pos;
1362
1363 buf = wpabuf_alloc(res->ie_len);
1364 if (buf == NULL)
1365 return NULL;
1366
1367 pos = (const u8 *) (res + 1);
1368 end = pos + res->ie_len;
1369
1370 while (pos + 1 < end) {
1371 if (pos + 2 + pos[1] > end)
1372 break;
1373 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1374 vendor_type == WPA_GET_BE32(&pos[2]))
1375 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1376 pos += 2 + pos[1];
1377 }
1378
1379 if (wpabuf_len(buf) == 0) {
1380 wpabuf_free(buf);
1381 buf = NULL;
1382 }
1383
1384 return buf;
1385 }
1386
1387
1388 /*
1389 * Channels with a great SNR can operate at full rate. What is a great SNR?
1390 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1391 * rule of thumb is that any SNR above 20 is good." This one
1392 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1393 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1394 * conservative value.
1395 */
1396 #define GREAT_SNR 30
1397
1398 /* Compare function for sorting scan results. Return >0 if @b is considered
1399 * better. */
wpa_scan_result_compar(const void * a,const void * b)1400 static int wpa_scan_result_compar(const void *a, const void *b)
1401 {
1402 #define IS_5GHZ(n) (n > 4000)
1403 #define MIN(a,b) a < b ? a : b
1404 struct wpa_scan_res **_wa = (void *) a;
1405 struct wpa_scan_res **_wb = (void *) b;
1406 struct wpa_scan_res *wa = *_wa;
1407 struct wpa_scan_res *wb = *_wb;
1408 int wpa_a, wpa_b, maxrate_a, maxrate_b;
1409 int snr_a, snr_b;
1410
1411 /* WPA/WPA2 support preferred */
1412 wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1413 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1414 wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1415 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1416
1417 if (wpa_b && !wpa_a)
1418 return 1;
1419 if (!wpa_b && wpa_a)
1420 return -1;
1421
1422 /* privacy support preferred */
1423 if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1424 (wb->caps & IEEE80211_CAP_PRIVACY))
1425 return 1;
1426 if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1427 (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1428 return -1;
1429
1430 if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1431 !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1432 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1433 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1434 } else {
1435 /* Not suitable information to calculate SNR, so use level */
1436 snr_a = wa->level;
1437 snr_b = wb->level;
1438 }
1439
1440 /* best/max rate preferred if SNR close enough */
1441 if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1442 (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1443 maxrate_a = wpa_scan_get_max_rate(wa);
1444 maxrate_b = wpa_scan_get_max_rate(wb);
1445 if (maxrate_a != maxrate_b)
1446 return maxrate_b - maxrate_a;
1447 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1448 return IS_5GHZ(wa->freq) ? -1 : 1;
1449 }
1450
1451 /* use freq for channel preference */
1452
1453 /* all things being equal, use SNR; if SNRs are
1454 * identical, use quality values since some drivers may only report
1455 * that value and leave the signal level zero */
1456 if (snr_b == snr_a)
1457 return wb->qual - wa->qual;
1458 return snr_b - snr_a;
1459 #undef MIN
1460 #undef IS_5GHZ
1461 }
1462
1463
1464 #ifdef CONFIG_WPS
1465 /* Compare function for sorting scan results when searching a WPS AP for
1466 * provisioning. Return >0 if @b is considered better. */
wpa_scan_result_wps_compar(const void * a,const void * b)1467 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1468 {
1469 struct wpa_scan_res **_wa = (void *) a;
1470 struct wpa_scan_res **_wb = (void *) b;
1471 struct wpa_scan_res *wa = *_wa;
1472 struct wpa_scan_res *wb = *_wb;
1473 int uses_wps_a, uses_wps_b;
1474 struct wpabuf *wps_a, *wps_b;
1475 int res;
1476
1477 /* Optimization - check WPS IE existence before allocated memory and
1478 * doing full reassembly. */
1479 uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1480 uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1481 if (uses_wps_a && !uses_wps_b)
1482 return -1;
1483 if (!uses_wps_a && uses_wps_b)
1484 return 1;
1485
1486 if (uses_wps_a && uses_wps_b) {
1487 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1488 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1489 res = wps_ap_priority_compar(wps_a, wps_b);
1490 wpabuf_free(wps_a);
1491 wpabuf_free(wps_b);
1492 if (res)
1493 return res;
1494 }
1495
1496 /*
1497 * Do not use current AP security policy as a sorting criteria during
1498 * WPS provisioning step since the AP may get reconfigured at the
1499 * completion of provisioning.
1500 */
1501
1502 /* all things being equal, use signal level; if signal levels are
1503 * identical, use quality values since some drivers may only report
1504 * that value and leave the signal level zero */
1505 if (wb->level == wa->level)
1506 return wb->qual - wa->qual;
1507 return wb->level - wa->level;
1508 }
1509 #endif /* CONFIG_WPS */
1510
1511
dump_scan_res(struct wpa_scan_results * scan_res)1512 static void dump_scan_res(struct wpa_scan_results *scan_res)
1513 {
1514 #ifndef CONFIG_NO_STDOUT_DEBUG
1515 size_t i;
1516
1517 if (scan_res->res == NULL || scan_res->num == 0)
1518 return;
1519
1520 wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1521
1522 for (i = 0; i < scan_res->num; i++) {
1523 struct wpa_scan_res *r = scan_res->res[i];
1524 u8 *pos;
1525 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1526 == WPA_SCAN_LEVEL_DBM) {
1527 int snr = r->level - r->noise;
1528 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1529 "noise=%d level=%d snr=%d%s flags=0x%x "
1530 "age=%u",
1531 MAC2STR(r->bssid), r->freq, r->qual,
1532 r->noise, r->level, snr,
1533 snr >= GREAT_SNR ? "*" : "", r->flags,
1534 r->age);
1535 } else {
1536 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1537 "noise=%d level=%d flags=0x%x age=%u",
1538 MAC2STR(r->bssid), r->freq, r->qual,
1539 r->noise, r->level, r->flags, r->age);
1540 }
1541 pos = (u8 *) (r + 1);
1542 if (r->ie_len)
1543 wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1544 pos += r->ie_len;
1545 if (r->beacon_ie_len)
1546 wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1547 pos, r->beacon_ie_len);
1548 }
1549 #endif /* CONFIG_NO_STDOUT_DEBUG */
1550 }
1551
1552
1553 /**
1554 * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1555 * @wpa_s: Pointer to wpa_supplicant data
1556 * @bssid: BSSID to check
1557 * Returns: 0 if the BSSID is filtered or 1 if not
1558 *
1559 * This function is used to filter out specific BSSIDs from scan reslts mainly
1560 * for testing purposes (SET bssid_filter ctrl_iface command).
1561 */
wpa_supplicant_filter_bssid_match(struct wpa_supplicant * wpa_s,const u8 * bssid)1562 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1563 const u8 *bssid)
1564 {
1565 size_t i;
1566
1567 if (wpa_s->bssid_filter == NULL)
1568 return 1;
1569
1570 for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1571 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1572 ETH_ALEN) == 0)
1573 return 1;
1574 }
1575
1576 return 0;
1577 }
1578
1579
filter_scan_res(struct wpa_supplicant * wpa_s,struct wpa_scan_results * res)1580 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1581 struct wpa_scan_results *res)
1582 {
1583 size_t i, j;
1584
1585 if (wpa_s->bssid_filter == NULL)
1586 return;
1587
1588 for (i = 0, j = 0; i < res->num; i++) {
1589 if (wpa_supplicant_filter_bssid_match(wpa_s,
1590 res->res[i]->bssid)) {
1591 res->res[j++] = res->res[i];
1592 } else {
1593 os_free(res->res[i]);
1594 res->res[i] = NULL;
1595 }
1596 }
1597
1598 if (res->num != j) {
1599 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1600 (int) (res->num - j));
1601 res->num = j;
1602 }
1603 }
1604
1605
1606 /**
1607 * wpa_supplicant_get_scan_results - Get scan results
1608 * @wpa_s: Pointer to wpa_supplicant data
1609 * @info: Information about what was scanned or %NULL if not available
1610 * @new_scan: Whether a new scan was performed
1611 * Returns: Scan results, %NULL on failure
1612 *
1613 * This function request the current scan results from the driver and updates
1614 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1615 * results with wpa_scan_results_free().
1616 */
1617 struct wpa_scan_results *
wpa_supplicant_get_scan_results(struct wpa_supplicant * wpa_s,struct scan_info * info,int new_scan)1618 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1619 struct scan_info *info, int new_scan)
1620 {
1621 struct wpa_scan_results *scan_res;
1622 size_t i;
1623 int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1624
1625 scan_res = wpa_drv_get_scan_results2(wpa_s);
1626 if (scan_res == NULL) {
1627 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1628 return NULL;
1629 }
1630 if (scan_res->fetch_time.sec == 0) {
1631 /*
1632 * Make sure we have a valid timestamp if the driver wrapper
1633 * does not set this.
1634 */
1635 os_get_time(&scan_res->fetch_time);
1636 }
1637 filter_scan_res(wpa_s, scan_res);
1638
1639 #ifdef CONFIG_WPS
1640 if (wpas_wps_in_progress(wpa_s)) {
1641 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1642 "provisioning rules");
1643 compar = wpa_scan_result_wps_compar;
1644 }
1645 #endif /* CONFIG_WPS */
1646
1647 qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1648 compar);
1649 dump_scan_res(scan_res);
1650
1651 wpa_bss_update_start(wpa_s);
1652 for (i = 0; i < scan_res->num; i++)
1653 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1654 &scan_res->fetch_time);
1655 wpa_bss_update_end(wpa_s, info, new_scan);
1656
1657 return scan_res;
1658 }
1659
1660
1661 /**
1662 * wpa_supplicant_update_scan_results - Update scan results from the driver
1663 * @wpa_s: Pointer to wpa_supplicant data
1664 * Returns: 0 on success, -1 on failure
1665 *
1666 * This function updates the BSS table within wpa_supplicant based on the
1667 * currently available scan results from the driver without requesting a new
1668 * scan. This is used in cases where the driver indicates an association
1669 * (including roaming within ESS) and wpa_supplicant does not yet have the
1670 * needed information to complete the connection (e.g., to perform validation
1671 * steps in 4-way handshake).
1672 */
wpa_supplicant_update_scan_results(struct wpa_supplicant * wpa_s)1673 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1674 {
1675 struct wpa_scan_results *scan_res;
1676 scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1677 if (scan_res == NULL)
1678 return -1;
1679 wpa_scan_results_free(scan_res);
1680
1681 return 0;
1682 }
1683
1684
1685 /**
1686 * scan_only_handler - Reports scan results
1687 */
scan_only_handler(struct wpa_supplicant * wpa_s,struct wpa_scan_results * scan_res)1688 void scan_only_handler(struct wpa_supplicant *wpa_s,
1689 struct wpa_scan_results *scan_res)
1690 {
1691 wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1692 wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1693 wpas_notify_scan_results(wpa_s);
1694 wpas_notify_scan_done(wpa_s, 1);
1695 }
1696
1697
wpas_scan_scheduled(struct wpa_supplicant * wpa_s)1698 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1699 {
1700 return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1701 }
1702