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 #ifndef ANDROID_P2P
270 wpa_supplicant_notify_scanning(wpa_s, 1);
271 #endif
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 #ifdef ANDROID_P2P
278 wpa_supplicant_notify_scanning(wpa_s, 1);
279 #endif
280 }
281
282 return ret;
283 }
284
285
wpa_supplicant_stop_sched_scan(struct wpa_supplicant * wpa_s)286 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
287 {
288 int ret;
289
290 ret = wpa_drv_stop_sched_scan(wpa_s);
291 if (ret) {
292 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
293 /* TODO: what to do if stopping fails? */
294 return -1;
295 }
296
297 return ret;
298 }
299
300
301 static struct wpa_driver_scan_filter *
wpa_supplicant_build_filter_ssids(struct wpa_config * conf,size_t * num_ssids)302 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
303 {
304 struct wpa_driver_scan_filter *ssids;
305 struct wpa_ssid *ssid;
306 size_t count;
307
308 *num_ssids = 0;
309 if (!conf->filter_ssids)
310 return NULL;
311
312 for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
313 if (ssid->ssid && ssid->ssid_len)
314 count++;
315 }
316 if (count == 0)
317 return NULL;
318 ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
319 if (ssids == NULL)
320 return NULL;
321
322 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
323 if (!ssid->ssid || !ssid->ssid_len)
324 continue;
325 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
326 ssids[*num_ssids].ssid_len = ssid->ssid_len;
327 (*num_ssids)++;
328 }
329
330 return ssids;
331 }
332
333
wpa_supplicant_optimize_freqs(struct wpa_supplicant * wpa_s,struct wpa_driver_scan_params * params)334 static void wpa_supplicant_optimize_freqs(
335 struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
336 {
337 #ifdef CONFIG_P2P
338 if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
339 wpa_s->go_params) {
340 /* Optimize provisioning state scan based on GO information */
341 if (wpa_s->p2p_in_provisioning < 5 &&
342 wpa_s->go_params->freq > 0) {
343 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
344 "preferred frequency %d MHz",
345 wpa_s->go_params->freq);
346 params->freqs = os_zalloc(2 * sizeof(int));
347 if (params->freqs)
348 params->freqs[0] = wpa_s->go_params->freq;
349 } else if (wpa_s->p2p_in_provisioning < 8 &&
350 wpa_s->go_params->freq_list[0]) {
351 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
352 "channels");
353 int_array_concat(¶ms->freqs,
354 wpa_s->go_params->freq_list);
355 if (params->freqs)
356 int_array_sort_unique(params->freqs);
357 }
358 wpa_s->p2p_in_provisioning++;
359 }
360 #endif /* CONFIG_P2P */
361
362 #ifdef CONFIG_WPS
363 if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
364 /*
365 * Optimize post-provisioning scan based on channel used
366 * during provisioning.
367 */
368 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
369 "that was used during provisioning", wpa_s->wps_freq);
370 params->freqs = os_zalloc(2 * sizeof(int));
371 if (params->freqs)
372 params->freqs[0] = wpa_s->wps_freq;
373 wpa_s->after_wps--;
374 }
375
376 if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
377 {
378 /* Optimize provisioning scan based on already known channel */
379 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
380 wpa_s->wps_freq);
381 params->freqs = os_zalloc(2 * sizeof(int));
382 if (params->freqs)
383 params->freqs[0] = wpa_s->wps_freq;
384 wpa_s->known_wps_freq = 0; /* only do this once */
385 }
386 #endif /* CONFIG_WPS */
387 }
388
389
390 #ifdef CONFIG_INTERWORKING
wpas_add_interworking_elements(struct wpa_supplicant * wpa_s,struct wpabuf * buf)391 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
392 struct wpabuf *buf)
393 {
394 if (wpa_s->conf->interworking == 0)
395 return;
396
397 wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
398 wpabuf_put_u8(buf, 4);
399 wpabuf_put_u8(buf, 0x00);
400 wpabuf_put_u8(buf, 0x00);
401 wpabuf_put_u8(buf, 0x00);
402 wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
403
404 wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
405 wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
406 1 + ETH_ALEN);
407 wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
408 /* No Venue Info */
409 if (!is_zero_ether_addr(wpa_s->conf->hessid))
410 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
411 }
412 #endif /* CONFIG_INTERWORKING */
413
414
wpa_supplicant_extra_ies(struct wpa_supplicant * wpa_s)415 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
416 {
417 struct wpabuf *extra_ie = NULL;
418 #ifdef CONFIG_WPS
419 int wps = 0;
420 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
421 #endif /* CONFIG_WPS */
422
423 #ifdef CONFIG_INTERWORKING
424 if (wpa_s->conf->interworking &&
425 wpabuf_resize(&extra_ie, 100) == 0)
426 wpas_add_interworking_elements(wpa_s, extra_ie);
427 #endif /* CONFIG_INTERWORKING */
428
429 #ifdef CONFIG_WPS
430 wps = wpas_wps_in_use(wpa_s, &req_type);
431
432 if (wps) {
433 struct wpabuf *wps_ie;
434 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
435 DEV_PW_DEFAULT,
436 &wpa_s->wps->dev,
437 wpa_s->wps->uuid, req_type,
438 0, NULL);
439 if (wps_ie) {
440 if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
441 wpabuf_put_buf(extra_ie, wps_ie);
442 wpabuf_free(wps_ie);
443 }
444 }
445
446 #ifdef CONFIG_P2P
447 if (wps) {
448 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
449 if (wpabuf_resize(&extra_ie, ielen) == 0)
450 wpas_p2p_scan_ie(wpa_s, extra_ie);
451 }
452 #endif /* CONFIG_P2P */
453
454 #endif /* CONFIG_WPS */
455
456 return extra_ie;
457 }
458
459
460 #ifdef CONFIG_P2P
461
462 /*
463 * Check whether there are any enabled networks or credentials that could be
464 * used for a non-P2P connection.
465 */
non_p2p_network_enabled(struct wpa_supplicant * wpa_s)466 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
467 {
468 struct wpa_ssid *ssid;
469
470 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
471 if (wpas_network_disabled(wpa_s, ssid))
472 continue;
473 if (!ssid->p2p_group)
474 return 1;
475 }
476
477 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
478 wpa_s->conf->auto_interworking)
479 return 1;
480
481 return 0;
482 }
483
484
485 /*
486 * Find the operating frequency of any other virtual interface that is using
487 * the same radio concurrently.
488 */
shared_vif_oper_freq(struct wpa_supplicant * wpa_s)489 static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s)
490 {
491 const char *rn, *rn2;
492 struct wpa_supplicant *ifs;
493 u8 bssid[ETH_ALEN];
494
495 if (!wpa_s->driver->get_radio_name)
496 return -1;
497
498 rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv);
499 if (rn == NULL || rn[0] == '\0')
500 return -1;
501
502 for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) {
503 if (ifs == wpa_s || !ifs->driver->get_radio_name)
504 continue;
505
506 rn2 = ifs->driver->get_radio_name(ifs->drv_priv);
507 if (!rn2 || os_strcmp(rn, rn2) != 0)
508 continue;
509
510 if (ifs->current_ssid == NULL || ifs->assoc_freq == 0)
511 continue;
512
513 if (ifs->current_ssid->mode == WPAS_MODE_AP ||
514 ifs->current_ssid->mode == WPAS_MODE_P2P_GO)
515 return ifs->current_ssid->frequency;
516 if (wpa_drv_get_bssid(ifs, bssid) == 0)
517 return ifs->assoc_freq;
518 }
519
520 return 0;
521 }
522
523 #endif /* CONFIG_P2P */
524
525
wpa_supplicant_scan(void * eloop_ctx,void * timeout_ctx)526 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
527 {
528 struct wpa_supplicant *wpa_s = eloop_ctx;
529 struct wpa_ssid *ssid;
530 enum scan_req_type scan_req = NORMAL_SCAN_REQ;
531 int ret;
532 struct wpabuf *extra_ie = NULL;
533 struct wpa_driver_scan_params params;
534 struct wpa_driver_scan_params *scan_params;
535 size_t max_ssids;
536 enum wpa_states prev_state;
537
538 if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
539 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
540 wpas_p2p_continue_after_scan(wpa_s);
541 return;
542 }
543
544 if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
545 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
546 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
547 wpas_p2p_continue_after_scan(wpa_s);
548 return;
549 }
550 #ifdef ANDROID
551 if (wpa_s->scanning) {
552 /* If we are already in scanning state, we shall ignore this new scan request*/
553 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - already scanning");
554 return;
555 }
556 #endif
557 if (!wpa_supplicant_enabled_networks(wpa_s) &&
558 wpa_s->scan_req == NORMAL_SCAN_REQ) {
559 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
560 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
561 wpas_p2p_continue_after_scan(wpa_s);
562 return;
563 }
564
565 if (wpa_s->conf->ap_scan != 0 &&
566 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
567 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
568 "overriding ap_scan configuration");
569 wpa_s->conf->ap_scan = 0;
570 wpas_notify_ap_scan_changed(wpa_s);
571 }
572
573 if (wpa_s->conf->ap_scan == 0) {
574 wpa_supplicant_gen_assoc_event(wpa_s);
575 return;
576 }
577
578 #ifdef CONFIG_P2P
579 if (wpas_p2p_in_progress(wpa_s)) {
580 if (wpa_s->sta_scan_pending &&
581 wpas_p2p_in_progress(wpa_s) == 2 &&
582 wpa_s->global->p2p_cb_on_scan_complete) {
583 wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
584 "mode scan during P2P search");
585 } else {
586 wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
587 "while P2P operation is in progress");
588 wpa_s->sta_scan_pending = 1;
589 wpa_supplicant_req_scan(wpa_s, 5, 0);
590 return;
591 }
592 }
593 #endif /* CONFIG_P2P */
594
595 if (wpa_s->conf->ap_scan == 2)
596 max_ssids = 1;
597 else {
598 max_ssids = wpa_s->max_scan_ssids;
599 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
600 max_ssids = WPAS_MAX_SCAN_SSIDS;
601 }
602
603 scan_req = wpa_s->scan_req;
604 wpa_s->scan_req = NORMAL_SCAN_REQ;
605
606 os_memset(¶ms, 0, sizeof(params));
607
608 prev_state = wpa_s->wpa_state;
609 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
610 wpa_s->wpa_state == WPA_INACTIVE)
611 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
612
613 /*
614 * If autoscan has set its own scanning parameters
615 */
616 if (wpa_s->autoscan_params != NULL) {
617 scan_params = wpa_s->autoscan_params;
618 goto scan;
619 }
620
621 if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
622 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
623 if (ssid == wpa_s->connect_without_scan)
624 break;
625 }
626 wpa_s->connect_without_scan = NULL;
627 if (ssid) {
628 wpa_printf(MSG_DEBUG, "Start a pre-selected network "
629 "without scan step");
630 wpa_supplicant_associate(wpa_s, NULL, ssid);
631 return;
632 }
633 }
634
635 #ifdef CONFIG_P2P
636 if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
637 wpa_s->go_params) {
638 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
639 "P2P group formation");
640 params.ssids[0].ssid = wpa_s->go_params->ssid;
641 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
642 params.num_ssids = 1;
643 goto ssid_list_set;
644 }
645 #endif /* CONFIG_P2P */
646
647 /* Find the starting point from which to continue scanning */
648 ssid = wpa_s->conf->ssid;
649 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
650 while (ssid) {
651 if (ssid == wpa_s->prev_scan_ssid) {
652 ssid = ssid->next;
653 break;
654 }
655 ssid = ssid->next;
656 }
657 }
658
659 if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
660 wpa_s->connect_without_scan = NULL;
661 wpa_s->prev_scan_wildcard = 0;
662 wpa_supplicant_assoc_try(wpa_s, ssid);
663 return;
664 #ifndef ANDROID
665 } else if (wpa_s->conf->ap_scan == 2) {
666 /*
667 * User-initiated scan request in ap_scan == 2; scan with
668 * wildcard SSID.
669 */
670 ssid = NULL;
671 #endif
672 } else {
673 struct wpa_ssid *start = ssid, *tssid;
674 int freqs_set = 0;
675 if (ssid == NULL && max_ssids > 1)
676 ssid = wpa_s->conf->ssid;
677 while (ssid) {
678 if (!wpas_network_disabled(wpa_s, ssid) &&
679 ssid->scan_ssid) {
680 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
681 ssid->ssid, ssid->ssid_len);
682 params.ssids[params.num_ssids].ssid =
683 ssid->ssid;
684 params.ssids[params.num_ssids].ssid_len =
685 ssid->ssid_len;
686 params.num_ssids++;
687 if (params.num_ssids + 1 >= max_ssids)
688 break;
689 }
690 ssid = ssid->next;
691 if (ssid == start)
692 break;
693 if (ssid == NULL && max_ssids > 1 &&
694 start != wpa_s->conf->ssid)
695 ssid = wpa_s->conf->ssid;
696 }
697
698 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
699 if (wpas_network_disabled(wpa_s, tssid))
700 continue;
701 if ((params.freqs || !freqs_set) && tssid->scan_freq) {
702 int_array_concat(¶ms.freqs,
703 tssid->scan_freq);
704 } else {
705 os_free(params.freqs);
706 params.freqs = NULL;
707 }
708 freqs_set = 1;
709 }
710 int_array_sort_unique(params.freqs);
711 }
712
713 if (ssid && max_ssids == 1) {
714 /*
715 * If the driver is limited to 1 SSID at a time interleave
716 * wildcard SSID scans with specific SSID scans to avoid
717 * waiting a long time for a wildcard scan.
718 */
719 if (!wpa_s->prev_scan_wildcard) {
720 params.ssids[0].ssid = NULL;
721 params.ssids[0].ssid_len = 0;
722 wpa_s->prev_scan_wildcard = 1;
723 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
724 "wildcard SSID (Interleave with specific)");
725 } else {
726 wpa_s->prev_scan_ssid = ssid;
727 wpa_s->prev_scan_wildcard = 0;
728 wpa_dbg(wpa_s, MSG_DEBUG,
729 "Starting AP scan for specific SSID: %s",
730 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
731 }
732 } else if (ssid) {
733 /* max_ssids > 1 */
734
735 wpa_s->prev_scan_ssid = ssid;
736 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
737 "the scan request");
738 params.num_ssids++;
739 } else {
740 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
741 params.num_ssids++;
742 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
743 "SSID");
744 }
745 #ifdef CONFIG_P2P
746 ssid_list_set:
747 #endif /* CONFIG_P2P */
748
749 wpa_supplicant_optimize_freqs(wpa_s, ¶ms);
750 extra_ie = wpa_supplicant_extra_ies(wpa_s);
751
752 #ifdef CONFIG_HS20
753 if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0)
754 wpas_hs20_add_indication(extra_ie);
755 #endif /* CONFIG_HS20 */
756
757 if (params.freqs == NULL && wpa_s->next_scan_freqs) {
758 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
759 "generated frequency list");
760 params.freqs = wpa_s->next_scan_freqs;
761 } else
762 os_free(wpa_s->next_scan_freqs);
763 wpa_s->next_scan_freqs = NULL;
764
765 params.filter_ssids = wpa_supplicant_build_filter_ssids(
766 wpa_s->conf, ¶ms.num_filter_ssids);
767 if (extra_ie) {
768 params.extra_ies = wpabuf_head(extra_ie);
769 params.extra_ies_len = wpabuf_len(extra_ie);
770 }
771
772 #ifdef CONFIG_P2P
773 if (wpa_s->p2p_in_provisioning ||
774 (wpa_s->show_group_started && wpa_s->go_params)) {
775 /*
776 * The interface may not yet be in P2P mode, so we have to
777 * explicitly request P2P probe to disable CCK rates.
778 */
779 params.p2p_probe = 1;
780 }
781 #endif /* CONFIG_P2P */
782
783 scan_params = ¶ms;
784
785 scan:
786 #ifdef CONFIG_P2P
787 /*
788 * If the driver does not support multi-channel concurrency and a
789 * virtual interface that shares the same radio with the wpa_s interface
790 * is operating there may not be need to scan other channels apart from
791 * the current operating channel on the other virtual interface. Filter
792 * out other channels in case we are trying to find a connection for a
793 * station interface when we are not configured to prefer station
794 * connection and a concurrent operation is already in process.
795 */
796 if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
797 !scan_params->freqs && !params.freqs &&
798 wpas_is_p2p_prioritized(wpa_s) &&
799 !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) &&
800 wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
801 non_p2p_network_enabled(wpa_s)) {
802 int freq = shared_vif_oper_freq(wpa_s);
803 if (freq > 0) {
804 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current "
805 "operating channel (%d MHz) since driver does "
806 "not support multi-channel concurrency", freq);
807 params.freqs = os_zalloc(sizeof(int) * 2);
808 if (params.freqs)
809 params.freqs[0] = freq;
810 scan_params->freqs = params.freqs;
811 }
812 }
813 #endif /* CONFIG_P2P */
814
815 ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
816
817 wpabuf_free(extra_ie);
818 os_free(params.freqs);
819 os_free(params.filter_ssids);
820
821 if (ret) {
822 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
823 if (prev_state != wpa_s->wpa_state)
824 wpa_supplicant_set_state(wpa_s, prev_state);
825 /* Restore scan_req since we will try to scan again */
826 wpa_s->scan_req = scan_req;
827 wpa_supplicant_req_scan(wpa_s, 1, 0);
828 } else {
829 wpa_s->scan_for_connection = 0;
830 }
831 }
832
833
wpa_supplicant_update_scan_int(struct wpa_supplicant * wpa_s,int sec)834 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
835 {
836 struct os_time remaining, new_int;
837 int cancelled;
838
839 cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
840 &remaining);
841
842 new_int.sec = sec;
843 new_int.usec = 0;
844 if (cancelled && os_time_before(&remaining, &new_int)) {
845 new_int.sec = remaining.sec;
846 new_int.usec = remaining.usec;
847 }
848
849 eloop_register_timeout(new_int.sec, new_int.usec, wpa_supplicant_scan,
850 wpa_s, NULL);
851 wpa_s->scan_interval = sec;
852 }
853
854
855 /**
856 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
857 * @wpa_s: Pointer to wpa_supplicant data
858 * @sec: Number of seconds after which to scan
859 * @usec: Number of microseconds after which to scan
860 *
861 * This function is used to schedule a scan for neighboring access points after
862 * the specified time.
863 */
wpa_supplicant_req_scan(struct wpa_supplicant * wpa_s,int sec,int usec)864 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
865 {
866 #ifndef ANDROID
867 /* If there's at least one network that should be specifically scanned
868 * then don't cancel the scan and reschedule. Some drivers do
869 * background scanning which generates frequent scan results, and that
870 * causes the specific SSID scan to get continually pushed back and
871 * never happen, which causes hidden APs to never get probe-scanned.
872 */
873 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
874 wpa_s->conf->ap_scan == 1) {
875 struct wpa_ssid *ssid = wpa_s->conf->ssid;
876
877 while (ssid) {
878 if (!wpas_network_disabled(wpa_s, ssid) &&
879 ssid->scan_ssid)
880 break;
881 ssid = ssid->next;
882 }
883 if (ssid) {
884 wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
885 "ensure that specific SSID scans occur");
886 return;
887 }
888 }
889 #endif
890 wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
891 sec, usec);
892 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
893 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
894 }
895
896
897 /**
898 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
899 * @wpa_s: Pointer to wpa_supplicant data
900 * @sec: Number of seconds after which to scan
901 * @usec: Number of microseconds after which to scan
902 * Returns: 0 on success or -1 otherwise
903 *
904 * This function is used to schedule periodic scans for neighboring
905 * access points after the specified time.
906 */
wpa_supplicant_delayed_sched_scan(struct wpa_supplicant * wpa_s,int sec,int usec)907 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
908 int sec, int usec)
909 {
910 if (!wpa_s->sched_scan_supported)
911 return -1;
912
913 eloop_register_timeout(sec, usec,
914 wpa_supplicant_delayed_sched_scan_timeout,
915 wpa_s, NULL);
916
917 return 0;
918 }
919
920
921 /**
922 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
923 * @wpa_s: Pointer to wpa_supplicant data
924 * Returns: 0 is sched_scan was started or -1 otherwise
925 *
926 * This function is used to schedule periodic scans for neighboring
927 * access points repeating the scan continuously.
928 */
wpa_supplicant_req_sched_scan(struct wpa_supplicant * wpa_s)929 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
930 {
931 struct wpa_driver_scan_params params;
932 struct wpa_driver_scan_params *scan_params;
933 enum wpa_states prev_state;
934 struct wpa_ssid *ssid = NULL;
935 struct wpabuf *extra_ie = NULL;
936 int ret;
937 unsigned int max_sched_scan_ssids;
938 int wildcard = 0;
939 int need_ssids;
940
941 if (!wpa_s->sched_scan_supported)
942 return -1;
943
944 if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
945 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
946 else
947 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
948 if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
949 return -1;
950
951 if (wpa_s->sched_scanning) {
952 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
953 return 0;
954 }
955
956 need_ssids = 0;
957 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
958 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
959 /* Use wildcard SSID to find this network */
960 wildcard = 1;
961 } else if (!wpas_network_disabled(wpa_s, ssid) &&
962 ssid->ssid_len)
963 need_ssids++;
964
965 #ifdef CONFIG_WPS
966 if (!wpas_network_disabled(wpa_s, ssid) &&
967 ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
968 /*
969 * Normal scan is more reliable and faster for WPS
970 * operations and since these are for short periods of
971 * time, the benefit of trying to use sched_scan would
972 * be limited.
973 */
974 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
975 "sched_scan for WPS");
976 return -1;
977 }
978 #endif /* CONFIG_WPS */
979 }
980 if (wildcard)
981 need_ssids++;
982
983 if (wpa_s->normal_scans < 3 &&
984 (need_ssids <= wpa_s->max_scan_ssids ||
985 wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
986 /*
987 * When normal scan can speed up operations, use that for the
988 * first operations before starting the sched_scan to allow
989 * user space sleep more. We do this only if the normal scan
990 * has functionality that is suitable for this or if the
991 * sched_scan does not have better support for multiple SSIDs.
992 */
993 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
994 "sched_scan for initial scans (normal_scans=%d)",
995 wpa_s->normal_scans);
996 return -1;
997 }
998
999 os_memset(¶ms, 0, sizeof(params));
1000
1001 /* If we can't allocate space for the filters, we just don't filter */
1002 params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1003 sizeof(struct wpa_driver_scan_filter));
1004
1005 prev_state = wpa_s->wpa_state;
1006 #ifndef ANDROID_P2P
1007 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1008 wpa_s->wpa_state == WPA_INACTIVE)
1009 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1010 #endif
1011
1012 if (wpa_s->autoscan_params != NULL) {
1013 scan_params = wpa_s->autoscan_params;
1014 goto scan;
1015 }
1016
1017 /* Find the starting point from which to continue scanning */
1018 ssid = wpa_s->conf->ssid;
1019 if (wpa_s->prev_sched_ssid) {
1020 while (ssid) {
1021 if (ssid == wpa_s->prev_sched_ssid) {
1022 ssid = ssid->next;
1023 break;
1024 }
1025 ssid = ssid->next;
1026 }
1027 }
1028
1029 if (!ssid || !wpa_s->prev_sched_ssid) {
1030 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1031
1032 if (wpa_s->sched_scan_interval == 0)
1033 wpa_s->sched_scan_interval = 10;
1034 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1035 wpa_s->first_sched_scan = 1;
1036 ssid = wpa_s->conf->ssid;
1037 wpa_s->prev_sched_ssid = ssid;
1038 }
1039
1040 if (wildcard) {
1041 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1042 params.num_ssids++;
1043 }
1044
1045 while (ssid) {
1046 if (wpas_network_disabled(wpa_s, ssid))
1047 goto next;
1048
1049 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1050 params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1051 wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1052 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1053 os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1054 ssid->ssid, ssid->ssid_len);
1055 params.filter_ssids[params.num_filter_ssids].ssid_len =
1056 ssid->ssid_len;
1057 params.num_filter_ssids++;
1058 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1059 {
1060 wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1061 "filter for sched_scan - drop filter");
1062 os_free(params.filter_ssids);
1063 params.filter_ssids = NULL;
1064 params.num_filter_ssids = 0;
1065 }
1066
1067 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1068 if (params.num_ssids == max_sched_scan_ssids)
1069 break; /* only room for broadcast SSID */
1070 wpa_dbg(wpa_s, MSG_DEBUG,
1071 "add to active scan ssid: %s",
1072 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1073 params.ssids[params.num_ssids].ssid =
1074 ssid->ssid;
1075 params.ssids[params.num_ssids].ssid_len =
1076 ssid->ssid_len;
1077 params.num_ssids++;
1078 if (params.num_ssids >= max_sched_scan_ssids) {
1079 wpa_s->prev_sched_ssid = ssid;
1080 do {
1081 ssid = ssid->next;
1082 } while (ssid &&
1083 (wpas_network_disabled(wpa_s, ssid) ||
1084 !ssid->scan_ssid));
1085 break;
1086 }
1087 }
1088
1089 next:
1090 wpa_s->prev_sched_ssid = ssid;
1091 ssid = ssid->next;
1092 }
1093
1094 if (params.num_filter_ssids == 0) {
1095 os_free(params.filter_ssids);
1096 params.filter_ssids = NULL;
1097 }
1098
1099 extra_ie = wpa_supplicant_extra_ies(wpa_s);
1100 if (extra_ie) {
1101 params.extra_ies = wpabuf_head(extra_ie);
1102 params.extra_ies_len = wpabuf_len(extra_ie);
1103 }
1104
1105 scan_params = ¶ms;
1106
1107 scan:
1108 if (ssid || !wpa_s->first_sched_scan) {
1109 wpa_dbg(wpa_s, MSG_DEBUG,
1110 "Starting sched scan: interval %d timeout %d",
1111 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1112 } else {
1113 wpa_dbg(wpa_s, MSG_DEBUG,
1114 "Starting sched scan: interval %d (no timeout)",
1115 wpa_s->sched_scan_interval);
1116 }
1117
1118 ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1119 wpa_s->sched_scan_interval);
1120 wpabuf_free(extra_ie);
1121 os_free(params.filter_ssids);
1122 if (ret) {
1123 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1124 if (prev_state != wpa_s->wpa_state)
1125 wpa_supplicant_set_state(wpa_s, prev_state);
1126 return ret;
1127 }
1128
1129 /* If we have more SSIDs to scan, add a timeout so we scan them too */
1130 if (ssid || !wpa_s->first_sched_scan) {
1131 wpa_s->sched_scan_timed_out = 0;
1132 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1133 wpa_supplicant_sched_scan_timeout,
1134 wpa_s, NULL);
1135 wpa_s->first_sched_scan = 0;
1136 wpa_s->sched_scan_timeout /= 2;
1137 wpa_s->sched_scan_interval *= 2;
1138 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1139 wpa_s->sched_scan_interval = 10;
1140 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1141 }
1142 }
1143
1144 /* If there is no more ssids, start next time from the beginning */
1145 if (!ssid)
1146 wpa_s->prev_sched_ssid = NULL;
1147
1148 return 0;
1149 }
1150
1151
1152 /**
1153 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1154 * @wpa_s: Pointer to wpa_supplicant data
1155 *
1156 * This function is used to cancel a scan request scheduled with
1157 * wpa_supplicant_req_scan().
1158 */
wpa_supplicant_cancel_scan(struct wpa_supplicant * wpa_s)1159 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1160 {
1161 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1162 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1163 wpas_p2p_continue_after_scan(wpa_s);
1164 #ifdef ANDROID
1165 wpa_supplicant_notify_scanning(wpa_s, 0);
1166 #endif
1167 }
1168
1169
1170 /**
1171 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1172 * @wpa_s: Pointer to wpa_supplicant data
1173 *
1174 * This function is used to stop a periodic scheduled scan.
1175 */
wpa_supplicant_cancel_sched_scan(struct wpa_supplicant * wpa_s)1176 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1177 {
1178 if (!wpa_s->sched_scanning)
1179 return;
1180
1181 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1182 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1183 wpa_supplicant_stop_sched_scan(wpa_s);
1184 }
1185
1186
1187 /**
1188 * wpa_supplicant_notify_scanning - Indicate possible scan state change
1189 * @wpa_s: Pointer to wpa_supplicant data
1190 * @scanning: Whether scanning is currently in progress
1191 *
1192 * This function is to generate scanning notifycations. It is called whenever
1193 * there may have been a change in scanning (scan started, completed, stopped).
1194 * wpas_notify_scanning() is called whenever the scanning state changed from the
1195 * previously notified state.
1196 */
wpa_supplicant_notify_scanning(struct wpa_supplicant * wpa_s,int scanning)1197 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1198 int scanning)
1199 {
1200 if (wpa_s->scanning != scanning) {
1201 #ifdef ANDROID_P2P
1202 if(!wpa_s->sched_scanning)
1203 wpa_s->scanning = scanning;
1204 #else
1205 wpa_s->scanning = scanning;
1206 #endif
1207 wpas_notify_scanning(wpa_s);
1208 }
1209 }
1210
1211
wpa_scan_get_max_rate(const struct wpa_scan_res * res)1212 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1213 {
1214 int rate = 0;
1215 const u8 *ie;
1216 int i;
1217
1218 ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1219 for (i = 0; ie && i < ie[1]; i++) {
1220 if ((ie[i + 2] & 0x7f) > rate)
1221 rate = ie[i + 2] & 0x7f;
1222 }
1223
1224 ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1225 for (i = 0; ie && i < ie[1]; i++) {
1226 if ((ie[i + 2] & 0x7f) > rate)
1227 rate = ie[i + 2] & 0x7f;
1228 }
1229
1230 return rate;
1231 }
1232
1233
1234 /**
1235 * wpa_scan_get_ie - Fetch a specified information element from a scan result
1236 * @res: Scan result entry
1237 * @ie: Information element identitifier (WLAN_EID_*)
1238 * Returns: Pointer to the information element (id field) or %NULL if not found
1239 *
1240 * This function returns the first matching information element in the scan
1241 * result.
1242 */
wpa_scan_get_ie(const struct wpa_scan_res * res,u8 ie)1243 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1244 {
1245 const u8 *end, *pos;
1246
1247 pos = (const u8 *) (res + 1);
1248 end = pos + res->ie_len;
1249
1250 while (pos + 1 < end) {
1251 if (pos + 2 + pos[1] > end)
1252 break;
1253 if (pos[0] == ie)
1254 return pos;
1255 pos += 2 + pos[1];
1256 }
1257
1258 return NULL;
1259 }
1260
1261
1262 /**
1263 * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1264 * @res: Scan result entry
1265 * @vendor_type: Vendor type (four octets starting the IE payload)
1266 * Returns: Pointer to the information element (id field) or %NULL if not found
1267 *
1268 * This function returns the first matching information element in the scan
1269 * result.
1270 */
wpa_scan_get_vendor_ie(const struct wpa_scan_res * res,u32 vendor_type)1271 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1272 u32 vendor_type)
1273 {
1274 const u8 *end, *pos;
1275
1276 pos = (const u8 *) (res + 1);
1277 end = pos + res->ie_len;
1278
1279 while (pos + 1 < end) {
1280 if (pos + 2 + pos[1] > end)
1281 break;
1282 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1283 vendor_type == WPA_GET_BE32(&pos[2]))
1284 return pos;
1285 pos += 2 + pos[1];
1286 }
1287
1288 return NULL;
1289 }
1290
1291
1292 /**
1293 * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1294 * @res: Scan result entry
1295 * @vendor_type: Vendor type (four octets starting the IE payload)
1296 * Returns: Pointer to the information element payload or %NULL if not found
1297 *
1298 * This function returns concatenated payload of possibly fragmented vendor
1299 * specific information elements in the scan result. The caller is responsible
1300 * for freeing the returned buffer.
1301 */
wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res * res,u32 vendor_type)1302 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1303 u32 vendor_type)
1304 {
1305 struct wpabuf *buf;
1306 const u8 *end, *pos;
1307
1308 buf = wpabuf_alloc(res->ie_len);
1309 if (buf == NULL)
1310 return NULL;
1311
1312 pos = (const u8 *) (res + 1);
1313 end = pos + res->ie_len;
1314
1315 while (pos + 1 < end) {
1316 if (pos + 2 + pos[1] > end)
1317 break;
1318 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1319 vendor_type == WPA_GET_BE32(&pos[2]))
1320 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1321 pos += 2 + pos[1];
1322 }
1323
1324 if (wpabuf_len(buf) == 0) {
1325 wpabuf_free(buf);
1326 buf = NULL;
1327 }
1328
1329 return buf;
1330 }
1331
1332
1333 /*
1334 * Channels with a great SNR can operate at full rate. What is a great SNR?
1335 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1336 * rule of thumb is that any SNR above 20 is good." This one
1337 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1338 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1339 * conservative value.
1340 */
1341 #define GREAT_SNR 30
1342
1343 /* Compare function for sorting scan results. Return >0 if @b is considered
1344 * better. */
wpa_scan_result_compar(const void * a,const void * b)1345 static int wpa_scan_result_compar(const void *a, const void *b)
1346 {
1347 #define IS_5GHZ(n) (n > 4000)
1348 #define MIN(a,b) a < b ? a : b
1349 struct wpa_scan_res **_wa = (void *) a;
1350 struct wpa_scan_res **_wb = (void *) b;
1351 struct wpa_scan_res *wa = *_wa;
1352 struct wpa_scan_res *wb = *_wb;
1353 int wpa_a, wpa_b, maxrate_a, maxrate_b;
1354 int snr_a, snr_b;
1355
1356 /* WPA/WPA2 support preferred */
1357 wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1358 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1359 wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1360 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1361
1362 if (wpa_b && !wpa_a)
1363 return 1;
1364 if (!wpa_b && wpa_a)
1365 return -1;
1366
1367 /* privacy support preferred */
1368 if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1369 (wb->caps & IEEE80211_CAP_PRIVACY))
1370 return 1;
1371 if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1372 (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1373 return -1;
1374
1375 if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1376 !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1377 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1378 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1379 } else {
1380 /* Not suitable information to calculate SNR, so use level */
1381 snr_a = wa->level;
1382 snr_b = wb->level;
1383 }
1384
1385 /* best/max rate preferred if SNR close enough */
1386 if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1387 (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1388 maxrate_a = wpa_scan_get_max_rate(wa);
1389 maxrate_b = wpa_scan_get_max_rate(wb);
1390 if (maxrate_a != maxrate_b)
1391 return maxrate_b - maxrate_a;
1392 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1393 return IS_5GHZ(wa->freq) ? -1 : 1;
1394 }
1395
1396 /* use freq for channel preference */
1397
1398 /* all things being equal, use SNR; if SNRs are
1399 * identical, use quality values since some drivers may only report
1400 * that value and leave the signal level zero */
1401 if (snr_b == snr_a)
1402 return wb->qual - wa->qual;
1403 return snr_b - snr_a;
1404 #undef MIN
1405 #undef IS_5GHZ
1406 }
1407
1408
1409 #ifdef CONFIG_WPS
1410 /* Compare function for sorting scan results when searching a WPS AP for
1411 * provisioning. Return >0 if @b is considered better. */
wpa_scan_result_wps_compar(const void * a,const void * b)1412 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1413 {
1414 struct wpa_scan_res **_wa = (void *) a;
1415 struct wpa_scan_res **_wb = (void *) b;
1416 struct wpa_scan_res *wa = *_wa;
1417 struct wpa_scan_res *wb = *_wb;
1418 int uses_wps_a, uses_wps_b;
1419 struct wpabuf *wps_a, *wps_b;
1420 int res;
1421
1422 /* Optimization - check WPS IE existence before allocated memory and
1423 * doing full reassembly. */
1424 uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1425 uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1426 if (uses_wps_a && !uses_wps_b)
1427 return -1;
1428 if (!uses_wps_a && uses_wps_b)
1429 return 1;
1430
1431 if (uses_wps_a && uses_wps_b) {
1432 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1433 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1434 res = wps_ap_priority_compar(wps_a, wps_b);
1435 wpabuf_free(wps_a);
1436 wpabuf_free(wps_b);
1437 if (res)
1438 return res;
1439 }
1440
1441 /*
1442 * Do not use current AP security policy as a sorting criteria during
1443 * WPS provisioning step since the AP may get reconfigured at the
1444 * completion of provisioning.
1445 */
1446
1447 /* all things being equal, use signal level; if signal levels are
1448 * identical, use quality values since some drivers may only report
1449 * that value and leave the signal level zero */
1450 if (wb->level == wa->level)
1451 return wb->qual - wa->qual;
1452 return wb->level - wa->level;
1453 }
1454 #endif /* CONFIG_WPS */
1455
1456
dump_scan_res(struct wpa_scan_results * scan_res)1457 static void dump_scan_res(struct wpa_scan_results *scan_res)
1458 {
1459 #ifndef CONFIG_NO_STDOUT_DEBUG
1460 size_t i;
1461
1462 if (scan_res->res == NULL || scan_res->num == 0)
1463 return;
1464
1465 wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1466
1467 for (i = 0; i < scan_res->num; i++) {
1468 struct wpa_scan_res *r = scan_res->res[i];
1469 u8 *pos;
1470 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1471 == WPA_SCAN_LEVEL_DBM) {
1472 int snr = r->level - r->noise;
1473 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1474 "noise=%d level=%d snr=%d%s flags=0x%x "
1475 "age=%u",
1476 MAC2STR(r->bssid), r->freq, r->qual,
1477 r->noise, r->level, snr,
1478 snr >= GREAT_SNR ? "*" : "", r->flags,
1479 r->age);
1480 } else {
1481 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1482 "noise=%d level=%d flags=0x%x age=%u",
1483 MAC2STR(r->bssid), r->freq, r->qual,
1484 r->noise, r->level, r->flags, r->age);
1485 }
1486 pos = (u8 *) (r + 1);
1487 if (r->ie_len)
1488 wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1489 pos += r->ie_len;
1490 if (r->beacon_ie_len)
1491 wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1492 pos, r->beacon_ie_len);
1493 }
1494 #endif /* CONFIG_NO_STDOUT_DEBUG */
1495 }
1496
1497
1498 /**
1499 * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1500 * @wpa_s: Pointer to wpa_supplicant data
1501 * @bssid: BSSID to check
1502 * Returns: 0 if the BSSID is filtered or 1 if not
1503 *
1504 * This function is used to filter out specific BSSIDs from scan reslts mainly
1505 * for testing purposes (SET bssid_filter ctrl_iface command).
1506 */
wpa_supplicant_filter_bssid_match(struct wpa_supplicant * wpa_s,const u8 * bssid)1507 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1508 const u8 *bssid)
1509 {
1510 size_t i;
1511
1512 if (wpa_s->bssid_filter == NULL)
1513 return 1;
1514
1515 for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1516 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1517 ETH_ALEN) == 0)
1518 return 1;
1519 }
1520
1521 return 0;
1522 }
1523
1524
filter_scan_res(struct wpa_supplicant * wpa_s,struct wpa_scan_results * res)1525 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1526 struct wpa_scan_results *res)
1527 {
1528 size_t i, j;
1529
1530 if (wpa_s->bssid_filter == NULL)
1531 return;
1532
1533 for (i = 0, j = 0; i < res->num; i++) {
1534 if (wpa_supplicant_filter_bssid_match(wpa_s,
1535 res->res[i]->bssid)) {
1536 res->res[j++] = res->res[i];
1537 } else {
1538 os_free(res->res[i]);
1539 res->res[i] = NULL;
1540 }
1541 }
1542
1543 if (res->num != j) {
1544 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1545 (int) (res->num - j));
1546 res->num = j;
1547 }
1548 }
1549
1550
1551 /**
1552 * wpa_supplicant_get_scan_results - Get scan results
1553 * @wpa_s: Pointer to wpa_supplicant data
1554 * @info: Information about what was scanned or %NULL if not available
1555 * @new_scan: Whether a new scan was performed
1556 * Returns: Scan results, %NULL on failure
1557 *
1558 * This function request the current scan results from the driver and updates
1559 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1560 * results with wpa_scan_results_free().
1561 */
1562 struct wpa_scan_results *
wpa_supplicant_get_scan_results(struct wpa_supplicant * wpa_s,struct scan_info * info,int new_scan)1563 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1564 struct scan_info *info, int new_scan)
1565 {
1566 struct wpa_scan_results *scan_res;
1567 size_t i;
1568 int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1569
1570 scan_res = wpa_drv_get_scan_results2(wpa_s);
1571 if (scan_res == NULL) {
1572 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1573 return NULL;
1574 }
1575 if (scan_res->fetch_time.sec == 0) {
1576 /*
1577 * Make sure we have a valid timestamp if the driver wrapper
1578 * does not set this.
1579 */
1580 os_get_time(&scan_res->fetch_time);
1581 }
1582 filter_scan_res(wpa_s, scan_res);
1583
1584 #ifdef CONFIG_WPS
1585 if (wpas_wps_in_progress(wpa_s)) {
1586 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1587 "provisioning rules");
1588 compar = wpa_scan_result_wps_compar;
1589 }
1590 #endif /* CONFIG_WPS */
1591
1592 qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1593 compar);
1594 dump_scan_res(scan_res);
1595
1596 wpa_bss_update_start(wpa_s);
1597 for (i = 0; i < scan_res->num; i++)
1598 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1599 &scan_res->fetch_time);
1600 wpa_bss_update_end(wpa_s, info, new_scan);
1601
1602 return scan_res;
1603 }
1604
1605
1606 /**
1607 * wpa_supplicant_update_scan_results - Update scan results from the driver
1608 * @wpa_s: Pointer to wpa_supplicant data
1609 * Returns: 0 on success, -1 on failure
1610 *
1611 * This function updates the BSS table within wpa_supplicant based on the
1612 * currently available scan results from the driver without requesting a new
1613 * scan. This is used in cases where the driver indicates an association
1614 * (including roaming within ESS) and wpa_supplicant does not yet have the
1615 * needed information to complete the connection (e.g., to perform validation
1616 * steps in 4-way handshake).
1617 */
wpa_supplicant_update_scan_results(struct wpa_supplicant * wpa_s)1618 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1619 {
1620 struct wpa_scan_results *scan_res;
1621 scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1622 if (scan_res == NULL)
1623 return -1;
1624 wpa_scan_results_free(scan_res);
1625
1626 return 0;
1627 }
1628
1629
1630 /**
1631 * scan_only_handler - Reports scan results
1632 */
scan_only_handler(struct wpa_supplicant * wpa_s,struct wpa_scan_results * scan_res)1633 void scan_only_handler(struct wpa_supplicant *wpa_s,
1634 struct wpa_scan_results *scan_res)
1635 {
1636 wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1637 wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1638 wpas_notify_scan_results(wpa_s);
1639 wpas_notify_scan_done(wpa_s, 1);
1640 }
1641
1642
wpas_scan_scheduled(struct wpa_supplicant * wpa_s)1643 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1644 {
1645 return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1646 }
1647