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Defer scan if connection is in progress on any of the shared interfaces
[thirdparty/hostap.git] / wpa_supplicant / scan.c
1 /*
2 * WPA Supplicant - Scanning
3 * Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "utils/includes.h"
10
11 #include "utils/common.h"
12 #include "utils/eloop.h"
13 #include "common/ieee802_11_defs.h"
14 #include "common/wpa_ctrl.h"
15 #include "config.h"
16 #include "wpa_supplicant_i.h"
17 #include "driver_i.h"
18 #include "wps_supplicant.h"
19 #include "p2p_supplicant.h"
20 #include "p2p/p2p.h"
21 #include "hs20_supplicant.h"
22 #include "notify.h"
23 #include "bss.h"
24 #include "scan.h"
25
26
27 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
28 {
29 struct wpa_ssid *ssid;
30 union wpa_event_data data;
31
32 ssid = wpa_supplicant_get_ssid(wpa_s);
33 if (ssid == NULL)
34 return;
35
36 if (wpa_s->current_ssid == NULL) {
37 wpa_s->current_ssid = ssid;
38 if (wpa_s->current_ssid != NULL)
39 wpas_notify_network_changed(wpa_s);
40 }
41 wpa_supplicant_initiate_eapol(wpa_s);
42 wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
43 "network - generating associated event");
44 os_memset(&data, 0, sizeof(data));
45 wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
46 }
47
48
49 #ifdef CONFIG_WPS
50 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
51 enum wps_request_type *req_type)
52 {
53 struct wpa_ssid *ssid;
54 int wps = 0;
55
56 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
57 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
58 continue;
59
60 wps = 1;
61 *req_type = wpas_wps_get_req_type(ssid);
62 if (!ssid->eap.phase1)
63 continue;
64
65 if (os_strstr(ssid->eap.phase1, "pbc=1"))
66 return 2;
67 }
68
69 #ifdef CONFIG_P2P
70 if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p &&
71 !wpa_s->conf->p2p_disabled) {
72 wpa_s->wps->dev.p2p = 1;
73 if (!wps) {
74 wps = 1;
75 *req_type = WPS_REQ_ENROLLEE_INFO;
76 }
77 }
78 #endif /* CONFIG_P2P */
79
80 return wps;
81 }
82 #endif /* CONFIG_WPS */
83
84
85 /**
86 * wpa_supplicant_enabled_networks - Check whether there are enabled networks
87 * @wpa_s: Pointer to wpa_supplicant data
88 * Returns: 0 if no networks are enabled, >0 if networks are enabled
89 *
90 * This function is used to figure out whether any networks (or Interworking
91 * with enabled credentials and auto_interworking) are present in the current
92 * configuration.
93 */
94 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
95 {
96 struct wpa_ssid *ssid = wpa_s->conf->ssid;
97 int count = 0, disabled = 0;
98 while (ssid) {
99 if (!wpas_network_disabled(wpa_s, ssid))
100 count++;
101 else
102 disabled++;
103 ssid = ssid->next;
104 }
105 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
106 wpa_s->conf->auto_interworking)
107 count++;
108 if (count == 0 && disabled > 0) {
109 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled "
110 "networks)", disabled);
111 }
112 return count;
113 }
114
115
116 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
117 struct wpa_ssid *ssid)
118 {
119 while (ssid) {
120 if (!wpas_network_disabled(wpa_s, ssid))
121 break;
122 ssid = ssid->next;
123 }
124
125 /* ap_scan=2 mode - try to associate with each SSID. */
126 if (ssid == NULL) {
127 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
128 "end of scan list - go back to beginning");
129 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
130 wpa_supplicant_req_scan(wpa_s, 0, 0);
131 return;
132 }
133 if (ssid->next) {
134 /* Continue from the next SSID on the next attempt. */
135 wpa_s->prev_scan_ssid = ssid;
136 } else {
137 /* Start from the beginning of the SSID list. */
138 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
139 }
140 wpa_supplicant_associate(wpa_s, NULL, ssid);
141 }
142
143
144 static int int_array_len(const int *a)
145 {
146 int i;
147 for (i = 0; a && a[i]; i++)
148 ;
149 return i;
150 }
151
152
153 static void int_array_concat(int **res, const int *a)
154 {
155 int reslen, alen, i;
156 int *n;
157
158 reslen = int_array_len(*res);
159 alen = int_array_len(a);
160
161 n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
162 if (n == NULL) {
163 os_free(*res);
164 *res = NULL;
165 return;
166 }
167 for (i = 0; i <= alen; i++)
168 n[reslen + i] = a[i];
169 *res = n;
170 }
171
172
173 static int freq_cmp(const void *a, const void *b)
174 {
175 int _a = *(int *) a;
176 int _b = *(int *) b;
177
178 if (_a == 0)
179 return 1;
180 if (_b == 0)
181 return -1;
182 return _a - _b;
183 }
184
185
186 static void int_array_sort_unique(int *a)
187 {
188 int alen;
189 int i, j;
190
191 if (a == NULL)
192 return;
193
194 alen = int_array_len(a);
195 qsort(a, alen, sizeof(int), freq_cmp);
196
197 i = 0;
198 j = 1;
199 while (a[i] && a[j]) {
200 if (a[i] == a[j]) {
201 j++;
202 continue;
203 }
204 a[++i] = a[j++];
205 }
206 if (a[i])
207 i++;
208 a[i] = 0;
209 }
210
211
212 /**
213 * wpa_supplicant_trigger_scan - Request driver to start a scan
214 * @wpa_s: Pointer to wpa_supplicant data
215 * @params: Scan parameters
216 * Returns: 0 on success, -1 on failure
217 */
218 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
219 struct wpa_driver_scan_params *params)
220 {
221 int ret;
222
223 wpa_supplicant_notify_scanning(wpa_s, 1);
224
225 ret = wpa_drv_scan(wpa_s, params);
226 if (ret) {
227 wpa_supplicant_notify_scanning(wpa_s, 0);
228 wpas_notify_scan_done(wpa_s, 0);
229 } else {
230 os_get_time(&wpa_s->scan_trigger_time);
231 wpa_s->scan_runs++;
232 wpa_s->normal_scans++;
233 }
234
235 return ret;
236 }
237
238
239 static void
240 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
241 {
242 struct wpa_supplicant *wpa_s = eloop_ctx;
243
244 wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
245
246 if (wpa_supplicant_req_sched_scan(wpa_s))
247 wpa_supplicant_req_scan(wpa_s, 0, 0);
248 }
249
250
251 static void
252 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
253 {
254 struct wpa_supplicant *wpa_s = eloop_ctx;
255
256 wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
257
258 wpa_s->sched_scan_timed_out = 1;
259 wpa_supplicant_cancel_sched_scan(wpa_s);
260 }
261
262
263 static int
264 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
265 struct wpa_driver_scan_params *params,
266 int interval)
267 {
268 int ret;
269
270 wpa_supplicant_notify_scanning(wpa_s, 1);
271 ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
272 if (ret)
273 wpa_supplicant_notify_scanning(wpa_s, 0);
274 else
275 wpa_s->sched_scanning = 1;
276
277 return ret;
278 }
279
280
281 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
282 {
283 int ret;
284
285 ret = wpa_drv_stop_sched_scan(wpa_s);
286 if (ret) {
287 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
288 /* TODO: what to do if stopping fails? */
289 return -1;
290 }
291
292 return ret;
293 }
294
295
296 static struct wpa_driver_scan_filter *
297 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
298 {
299 struct wpa_driver_scan_filter *ssids;
300 struct wpa_ssid *ssid;
301 size_t count;
302
303 *num_ssids = 0;
304 if (!conf->filter_ssids)
305 return NULL;
306
307 for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
308 if (ssid->ssid && ssid->ssid_len)
309 count++;
310 }
311 if (count == 0)
312 return NULL;
313 ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
314 if (ssids == NULL)
315 return NULL;
316
317 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
318 if (!ssid->ssid || !ssid->ssid_len)
319 continue;
320 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
321 ssids[*num_ssids].ssid_len = ssid->ssid_len;
322 (*num_ssids)++;
323 }
324
325 return ssids;
326 }
327
328
329 static void wpa_supplicant_optimize_freqs(
330 struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
331 {
332 #ifdef CONFIG_P2P
333 if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
334 wpa_s->go_params) {
335 /* Optimize provisioning state scan based on GO information */
336 if (wpa_s->p2p_in_provisioning < 5 &&
337 wpa_s->go_params->freq > 0) {
338 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
339 "preferred frequency %d MHz",
340 wpa_s->go_params->freq);
341 params->freqs = os_zalloc(2 * sizeof(int));
342 if (params->freqs)
343 params->freqs[0] = wpa_s->go_params->freq;
344 } else if (wpa_s->p2p_in_provisioning < 8 &&
345 wpa_s->go_params->freq_list[0]) {
346 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
347 "channels");
348 int_array_concat(&params->freqs,
349 wpa_s->go_params->freq_list);
350 if (params->freqs)
351 int_array_sort_unique(params->freqs);
352 }
353 wpa_s->p2p_in_provisioning++;
354 }
355 #endif /* CONFIG_P2P */
356
357 #ifdef CONFIG_WPS
358 if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
359 /*
360 * Optimize post-provisioning scan based on channel used
361 * during provisioning.
362 */
363 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
364 "that was used during provisioning", wpa_s->wps_freq);
365 params->freqs = os_zalloc(2 * sizeof(int));
366 if (params->freqs)
367 params->freqs[0] = wpa_s->wps_freq;
368 wpa_s->after_wps--;
369 }
370
371 if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
372 {
373 /* Optimize provisioning scan based on already known channel */
374 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
375 wpa_s->wps_freq);
376 params->freqs = os_zalloc(2 * sizeof(int));
377 if (params->freqs)
378 params->freqs[0] = wpa_s->wps_freq;
379 wpa_s->known_wps_freq = 0; /* only do this once */
380 }
381 #endif /* CONFIG_WPS */
382 }
383
384
385 #ifdef CONFIG_INTERWORKING
386 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
387 struct wpabuf *buf)
388 {
389 if (wpa_s->conf->interworking == 0)
390 return;
391
392 wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
393 wpabuf_put_u8(buf, 4);
394 wpabuf_put_u8(buf, 0x00);
395 wpabuf_put_u8(buf, 0x00);
396 wpabuf_put_u8(buf, 0x00);
397 wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
398
399 wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
400 wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
401 1 + ETH_ALEN);
402 wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
403 /* No Venue Info */
404 if (!is_zero_ether_addr(wpa_s->conf->hessid))
405 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
406 }
407 #endif /* CONFIG_INTERWORKING */
408
409
410 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
411 {
412 struct wpabuf *extra_ie = NULL;
413 #ifdef CONFIG_WPS
414 int wps = 0;
415 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
416 #endif /* CONFIG_WPS */
417
418 #ifdef CONFIG_INTERWORKING
419 if (wpa_s->conf->interworking &&
420 wpabuf_resize(&extra_ie, 100) == 0)
421 wpas_add_interworking_elements(wpa_s, extra_ie);
422 #endif /* CONFIG_INTERWORKING */
423
424 #ifdef CONFIG_WPS
425 wps = wpas_wps_in_use(wpa_s, &req_type);
426
427 if (wps) {
428 struct wpabuf *wps_ie;
429 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
430 DEV_PW_DEFAULT,
431 &wpa_s->wps->dev,
432 wpa_s->wps->uuid, req_type,
433 0, NULL);
434 if (wps_ie) {
435 if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
436 wpabuf_put_buf(extra_ie, wps_ie);
437 wpabuf_free(wps_ie);
438 }
439 }
440
441 #ifdef CONFIG_P2P
442 if (wps) {
443 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
444 if (wpabuf_resize(&extra_ie, ielen) == 0)
445 wpas_p2p_scan_ie(wpa_s, extra_ie);
446 }
447 #endif /* CONFIG_P2P */
448
449 #endif /* CONFIG_WPS */
450
451 #ifdef CONFIG_HS20
452 if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0)
453 wpas_hs20_add_indication(extra_ie);
454 #endif /* CONFIG_HS20 */
455
456 return extra_ie;
457 }
458
459
460 #ifdef CONFIG_P2P
461
462 /*
463 * Check whether there are any enabled networks or credentials that could be
464 * used for a non-P2P connection.
465 */
466 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
467 {
468 struct wpa_ssid *ssid;
469
470 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
471 if (wpas_network_disabled(wpa_s, ssid))
472 continue;
473 if (!ssid->p2p_group)
474 return 1;
475 }
476
477 if (wpa_s->conf->cred && wpa_s->conf->interworking &&
478 wpa_s->conf->auto_interworking)
479 return 1;
480
481 return 0;
482 }
483
484 #endif /* CONFIG_P2P */
485
486 /*
487 * Find the operating frequency of any other virtual interface that is using
488 * the same radio concurrently.
489 */
490 static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s)
491 {
492 const char *rn, *rn2;
493 struct wpa_supplicant *ifs;
494 u8 bssid[ETH_ALEN];
495
496 if (!wpa_s->driver->get_radio_name)
497 return -1;
498
499 rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv);
500 if (rn == NULL || rn[0] == '\0')
501 return -1;
502
503 for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) {
504 if (ifs == wpa_s || !ifs->driver->get_radio_name)
505 continue;
506
507 rn2 = ifs->driver->get_radio_name(ifs->drv_priv);
508 if (!rn2 || os_strcmp(rn, rn2) != 0)
509 continue;
510
511 if (ifs->current_ssid == NULL || ifs->assoc_freq == 0)
512 continue;
513
514 if (ifs->current_ssid->mode == WPAS_MODE_AP ||
515 ifs->current_ssid->mode == WPAS_MODE_P2P_GO)
516 return ifs->current_ssid->frequency;
517 if (wpa_drv_get_bssid(ifs, bssid) == 0)
518 return ifs->assoc_freq;
519 }
520
521 return 0;
522 }
523
524
525 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
526 {
527 struct wpa_supplicant *wpa_s = eloop_ctx;
528 struct wpa_ssid *ssid;
529 enum scan_req_type scan_req = NORMAL_SCAN_REQ;
530 int ret;
531 struct wpabuf *extra_ie = NULL;
532 struct wpa_driver_scan_params params;
533 struct wpa_driver_scan_params *scan_params;
534 size_t max_ssids;
535 enum wpa_states prev_state;
536
537 if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
538 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
539 wpas_p2p_continue_after_scan(wpa_s);
540 return;
541 }
542
543 if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
544 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
545 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
546 wpas_p2p_continue_after_scan(wpa_s);
547 return;
548 }
549
550 if (!wpa_supplicant_enabled_networks(wpa_s) &&
551 wpa_s->scan_req == NORMAL_SCAN_REQ) {
552 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
553 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
554 wpas_p2p_continue_after_scan(wpa_s);
555 return;
556 }
557
558 if (wpa_s->conf->ap_scan != 0 &&
559 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
560 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
561 "overriding ap_scan configuration");
562 wpa_s->conf->ap_scan = 0;
563 wpas_notify_ap_scan_changed(wpa_s);
564 }
565
566 if (wpa_s->conf->ap_scan == 0) {
567 wpa_supplicant_gen_assoc_event(wpa_s);
568 return;
569 }
570
571 #ifdef CONFIG_P2P
572 if (wpas_p2p_in_progress(wpa_s) || wpas_wpa_is_in_progress(wpa_s)) {
573 if (wpa_s->sta_scan_pending &&
574 wpas_p2p_in_progress(wpa_s) == 2 &&
575 wpa_s->global->p2p_cb_on_scan_complete) {
576 wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
577 "mode scan during P2P search");
578 } else {
579 wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
580 "while P2P operation is in progress");
581 wpa_s->sta_scan_pending = 1;
582 wpa_supplicant_req_scan(wpa_s, 5, 0);
583 return;
584 }
585 }
586 #endif /* CONFIG_P2P */
587
588 if (wpa_s->conf->ap_scan == 2)
589 max_ssids = 1;
590 else {
591 max_ssids = wpa_s->max_scan_ssids;
592 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
593 max_ssids = WPAS_MAX_SCAN_SSIDS;
594 }
595
596 scan_req = wpa_s->scan_req;
597 wpa_s->scan_req = NORMAL_SCAN_REQ;
598
599 os_memset(&params, 0, sizeof(params));
600
601 prev_state = wpa_s->wpa_state;
602 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
603 wpa_s->wpa_state == WPA_INACTIVE)
604 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
605
606 /*
607 * If autoscan has set its own scanning parameters
608 */
609 if (wpa_s->autoscan_params != NULL) {
610 scan_params = wpa_s->autoscan_params;
611 goto scan;
612 }
613
614 if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
615 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
616 if (ssid == wpa_s->connect_without_scan)
617 break;
618 }
619 wpa_s->connect_without_scan = NULL;
620 if (ssid) {
621 wpa_printf(MSG_DEBUG, "Start a pre-selected network "
622 "without scan step");
623 wpa_supplicant_associate(wpa_s, NULL, ssid);
624 return;
625 }
626 }
627
628 #ifdef CONFIG_P2P
629 if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
630 wpa_s->go_params) {
631 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
632 "P2P group formation");
633 params.ssids[0].ssid = wpa_s->go_params->ssid;
634 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
635 params.num_ssids = 1;
636 goto ssid_list_set;
637 }
638 #endif /* CONFIG_P2P */
639
640 /* Find the starting point from which to continue scanning */
641 ssid = wpa_s->conf->ssid;
642 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
643 while (ssid) {
644 if (ssid == wpa_s->prev_scan_ssid) {
645 ssid = ssid->next;
646 break;
647 }
648 ssid = ssid->next;
649 }
650 }
651
652 if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
653 wpa_s->connect_without_scan = NULL;
654 wpa_s->prev_scan_wildcard = 0;
655 wpa_supplicant_assoc_try(wpa_s, ssid);
656 return;
657 } else if (wpa_s->conf->ap_scan == 2) {
658 /*
659 * User-initiated scan request in ap_scan == 2; scan with
660 * wildcard SSID.
661 */
662 ssid = NULL;
663 } else {
664 struct wpa_ssid *start = ssid, *tssid;
665 int freqs_set = 0;
666 if (ssid == NULL && max_ssids > 1)
667 ssid = wpa_s->conf->ssid;
668 while (ssid) {
669 if (!wpas_network_disabled(wpa_s, ssid) &&
670 ssid->scan_ssid) {
671 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
672 ssid->ssid, ssid->ssid_len);
673 params.ssids[params.num_ssids].ssid =
674 ssid->ssid;
675 params.ssids[params.num_ssids].ssid_len =
676 ssid->ssid_len;
677 params.num_ssids++;
678 if (params.num_ssids + 1 >= max_ssids)
679 break;
680 }
681 ssid = ssid->next;
682 if (ssid == start)
683 break;
684 if (ssid == NULL && max_ssids > 1 &&
685 start != wpa_s->conf->ssid)
686 ssid = wpa_s->conf->ssid;
687 }
688
689 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
690 if (wpas_network_disabled(wpa_s, tssid))
691 continue;
692 if ((params.freqs || !freqs_set) && tssid->scan_freq) {
693 int_array_concat(&params.freqs,
694 tssid->scan_freq);
695 } else {
696 os_free(params.freqs);
697 params.freqs = NULL;
698 }
699 freqs_set = 1;
700 }
701 int_array_sort_unique(params.freqs);
702 }
703
704 if (ssid && max_ssids == 1) {
705 /*
706 * If the driver is limited to 1 SSID at a time interleave
707 * wildcard SSID scans with specific SSID scans to avoid
708 * waiting a long time for a wildcard scan.
709 */
710 if (!wpa_s->prev_scan_wildcard) {
711 params.ssids[0].ssid = NULL;
712 params.ssids[0].ssid_len = 0;
713 wpa_s->prev_scan_wildcard = 1;
714 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
715 "wildcard SSID (Interleave with specific)");
716 } else {
717 wpa_s->prev_scan_ssid = ssid;
718 wpa_s->prev_scan_wildcard = 0;
719 wpa_dbg(wpa_s, MSG_DEBUG,
720 "Starting AP scan for specific SSID: %s",
721 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
722 }
723 } else if (ssid) {
724 /* max_ssids > 1 */
725
726 wpa_s->prev_scan_ssid = ssid;
727 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
728 "the scan request");
729 params.num_ssids++;
730 } else {
731 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
732 params.num_ssids++;
733 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
734 "SSID");
735 }
736 #ifdef CONFIG_P2P
737 ssid_list_set:
738 #endif /* CONFIG_P2P */
739
740 wpa_supplicant_optimize_freqs(wpa_s, &params);
741 extra_ie = wpa_supplicant_extra_ies(wpa_s);
742
743 if (params.freqs == NULL && wpa_s->next_scan_freqs) {
744 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
745 "generated frequency list");
746 params.freqs = wpa_s->next_scan_freqs;
747 } else
748 os_free(wpa_s->next_scan_freqs);
749 wpa_s->next_scan_freqs = NULL;
750
751 /* See if user specified frequencies. If so, scan only those. */
752 if (wpa_s->conf->freq_list && !params.freqs) {
753 wpa_dbg(wpa_s, MSG_DEBUG,
754 "Optimize scan based on conf->freq_list");
755 int_array_concat(&params.freqs, wpa_s->conf->freq_list);
756 }
757
758 /* Use current associated channel? */
759 if (wpa_s->conf->scan_cur_freq && !params.freqs) {
760 int freq = shared_vif_oper_freq(wpa_s);
761 if (freq > 0) {
762 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the current "
763 "operating channel (%d MHz) since "
764 "scan_cur_freq is enabled", freq);
765 params.freqs = os_zalloc(sizeof(int) * 2);
766 if (params.freqs)
767 params.freqs[0] = freq;
768 }
769 }
770
771 params.filter_ssids = wpa_supplicant_build_filter_ssids(
772 wpa_s->conf, &params.num_filter_ssids);
773 if (extra_ie) {
774 params.extra_ies = wpabuf_head(extra_ie);
775 params.extra_ies_len = wpabuf_len(extra_ie);
776 }
777
778 #ifdef CONFIG_P2P
779 if (wpa_s->p2p_in_provisioning ||
780 (wpa_s->show_group_started && wpa_s->go_params)) {
781 /*
782 * The interface may not yet be in P2P mode, so we have to
783 * explicitly request P2P probe to disable CCK rates.
784 */
785 params.p2p_probe = 1;
786 }
787 #endif /* CONFIG_P2P */
788
789 scan_params = &params;
790
791 scan:
792 #ifdef CONFIG_P2P
793 /*
794 * If the driver does not support multi-channel concurrency and a
795 * virtual interface that shares the same radio with the wpa_s interface
796 * is operating there may not be need to scan other channels apart from
797 * the current operating channel on the other virtual interface. Filter
798 * out other channels in case we are trying to find a connection for a
799 * station interface when we are not configured to prefer station
800 * connection and a concurrent operation is already in process.
801 */
802 if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
803 !scan_params->freqs && !params.freqs &&
804 wpas_is_p2p_prioritized(wpa_s) &&
805 !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) &&
806 wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
807 non_p2p_network_enabled(wpa_s)) {
808 int freq = shared_vif_oper_freq(wpa_s);
809 if (freq > 0) {
810 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current "
811 "operating channel (%d MHz) since driver does "
812 "not support multi-channel concurrency", freq);
813 params.freqs = os_zalloc(sizeof(int) * 2);
814 if (params.freqs)
815 params.freqs[0] = freq;
816 scan_params->freqs = params.freqs;
817 }
818 }
819 #endif /* CONFIG_P2P */
820
821 ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
822
823 wpabuf_free(extra_ie);
824 os_free(params.freqs);
825 os_free(params.filter_ssids);
826
827 if (ret) {
828 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
829 if (prev_state != wpa_s->wpa_state)
830 wpa_supplicant_set_state(wpa_s, prev_state);
831 /* Restore scan_req since we will try to scan again */
832 wpa_s->scan_req = scan_req;
833 wpa_supplicant_req_scan(wpa_s, 1, 0);
834 } else {
835 wpa_s->scan_for_connection = 0;
836 }
837 }
838
839
840 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
841 {
842 struct os_time remaining, new_int;
843 int cancelled;
844
845 cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
846 &remaining);
847
848 new_int.sec = sec;
849 new_int.usec = 0;
850 if (cancelled && os_time_before(&remaining, &new_int)) {
851 new_int.sec = remaining.sec;
852 new_int.usec = remaining.usec;
853 }
854
855 eloop_register_timeout(new_int.sec, new_int.usec, wpa_supplicant_scan,
856 wpa_s, NULL);
857 wpa_s->scan_interval = sec;
858 }
859
860
861 /**
862 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
863 * @wpa_s: Pointer to wpa_supplicant data
864 * @sec: Number of seconds after which to scan
865 * @usec: Number of microseconds after which to scan
866 *
867 * This function is used to schedule a scan for neighboring access points after
868 * the specified time.
869 */
870 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
871 {
872 /* If there's at least one network that should be specifically scanned
873 * then don't cancel the scan and reschedule. Some drivers do
874 * background scanning which generates frequent scan results, and that
875 * causes the specific SSID scan to get continually pushed back and
876 * never happen, which causes hidden APs to never get probe-scanned.
877 */
878 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
879 wpa_s->conf->ap_scan == 1) {
880 struct wpa_ssid *ssid = wpa_s->conf->ssid;
881
882 while (ssid) {
883 if (!wpas_network_disabled(wpa_s, ssid) &&
884 ssid->scan_ssid)
885 break;
886 ssid = ssid->next;
887 }
888 if (ssid) {
889 wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
890 "ensure that specific SSID scans occur");
891 return;
892 }
893 }
894
895 wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
896 sec, usec);
897 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
898 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
899 }
900
901
902 /**
903 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
904 * @wpa_s: Pointer to wpa_supplicant data
905 * @sec: Number of seconds after which to scan
906 * @usec: Number of microseconds after which to scan
907 * Returns: 0 on success or -1 otherwise
908 *
909 * This function is used to schedule periodic scans for neighboring
910 * access points after the specified time.
911 */
912 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
913 int sec, int usec)
914 {
915 if (!wpa_s->sched_scan_supported)
916 return -1;
917
918 eloop_register_timeout(sec, usec,
919 wpa_supplicant_delayed_sched_scan_timeout,
920 wpa_s, NULL);
921
922 return 0;
923 }
924
925
926 /**
927 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
928 * @wpa_s: Pointer to wpa_supplicant data
929 * Returns: 0 is sched_scan was started or -1 otherwise
930 *
931 * This function is used to schedule periodic scans for neighboring
932 * access points repeating the scan continuously.
933 */
934 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
935 {
936 struct wpa_driver_scan_params params;
937 struct wpa_driver_scan_params *scan_params;
938 enum wpa_states prev_state;
939 struct wpa_ssid *ssid = NULL;
940 struct wpabuf *extra_ie = NULL;
941 int ret;
942 unsigned int max_sched_scan_ssids;
943 int wildcard = 0;
944 int need_ssids;
945
946 if (!wpa_s->sched_scan_supported)
947 return -1;
948
949 if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
950 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
951 else
952 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
953 if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
954 return -1;
955
956 if (wpa_s->sched_scanning) {
957 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
958 return 0;
959 }
960
961 need_ssids = 0;
962 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
963 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
964 /* Use wildcard SSID to find this network */
965 wildcard = 1;
966 } else if (!wpas_network_disabled(wpa_s, ssid) &&
967 ssid->ssid_len)
968 need_ssids++;
969
970 #ifdef CONFIG_WPS
971 if (!wpas_network_disabled(wpa_s, ssid) &&
972 ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
973 /*
974 * Normal scan is more reliable and faster for WPS
975 * operations and since these are for short periods of
976 * time, the benefit of trying to use sched_scan would
977 * be limited.
978 */
979 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
980 "sched_scan for WPS");
981 return -1;
982 }
983 #endif /* CONFIG_WPS */
984 }
985 if (wildcard)
986 need_ssids++;
987
988 if (wpa_s->normal_scans < 3 &&
989 (need_ssids <= wpa_s->max_scan_ssids ||
990 wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
991 /*
992 * When normal scan can speed up operations, use that for the
993 * first operations before starting the sched_scan to allow
994 * user space sleep more. We do this only if the normal scan
995 * has functionality that is suitable for this or if the
996 * sched_scan does not have better support for multiple SSIDs.
997 */
998 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
999 "sched_scan for initial scans (normal_scans=%d)",
1000 wpa_s->normal_scans);
1001 return -1;
1002 }
1003
1004 os_memset(&params, 0, sizeof(params));
1005
1006 /* If we can't allocate space for the filters, we just don't filter */
1007 params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1008 sizeof(struct wpa_driver_scan_filter));
1009
1010 prev_state = wpa_s->wpa_state;
1011 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1012 wpa_s->wpa_state == WPA_INACTIVE)
1013 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1014
1015 if (wpa_s->autoscan_params != NULL) {
1016 scan_params = wpa_s->autoscan_params;
1017 goto scan;
1018 }
1019
1020 /* Find the starting point from which to continue scanning */
1021 ssid = wpa_s->conf->ssid;
1022 if (wpa_s->prev_sched_ssid) {
1023 while (ssid) {
1024 if (ssid == wpa_s->prev_sched_ssid) {
1025 ssid = ssid->next;
1026 break;
1027 }
1028 ssid = ssid->next;
1029 }
1030 }
1031
1032 if (!ssid || !wpa_s->prev_sched_ssid) {
1033 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1034 if (wpa_s->conf->sched_scan_interval)
1035 wpa_s->sched_scan_interval =
1036 wpa_s->conf->sched_scan_interval;
1037 if (wpa_s->sched_scan_interval == 0)
1038 wpa_s->sched_scan_interval = 10;
1039 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1040 wpa_s->first_sched_scan = 1;
1041 ssid = wpa_s->conf->ssid;
1042 wpa_s->prev_sched_ssid = ssid;
1043 }
1044
1045 if (wildcard) {
1046 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1047 params.num_ssids++;
1048 }
1049
1050 while (ssid) {
1051 if (wpas_network_disabled(wpa_s, ssid))
1052 goto next;
1053
1054 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1055 params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1056 wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1057 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1058 os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1059 ssid->ssid, ssid->ssid_len);
1060 params.filter_ssids[params.num_filter_ssids].ssid_len =
1061 ssid->ssid_len;
1062 params.num_filter_ssids++;
1063 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1064 {
1065 wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1066 "filter for sched_scan - drop filter");
1067 os_free(params.filter_ssids);
1068 params.filter_ssids = NULL;
1069 params.num_filter_ssids = 0;
1070 }
1071
1072 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1073 if (params.num_ssids == max_sched_scan_ssids)
1074 break; /* only room for broadcast SSID */
1075 wpa_dbg(wpa_s, MSG_DEBUG,
1076 "add to active scan ssid: %s",
1077 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1078 params.ssids[params.num_ssids].ssid =
1079 ssid->ssid;
1080 params.ssids[params.num_ssids].ssid_len =
1081 ssid->ssid_len;
1082 params.num_ssids++;
1083 if (params.num_ssids >= max_sched_scan_ssids) {
1084 wpa_s->prev_sched_ssid = ssid;
1085 do {
1086 ssid = ssid->next;
1087 } while (ssid &&
1088 (wpas_network_disabled(wpa_s, ssid) ||
1089 !ssid->scan_ssid));
1090 break;
1091 }
1092 }
1093
1094 next:
1095 wpa_s->prev_sched_ssid = ssid;
1096 ssid = ssid->next;
1097 }
1098
1099 if (params.num_filter_ssids == 0) {
1100 os_free(params.filter_ssids);
1101 params.filter_ssids = NULL;
1102 }
1103
1104 extra_ie = wpa_supplicant_extra_ies(wpa_s);
1105 if (extra_ie) {
1106 params.extra_ies = wpabuf_head(extra_ie);
1107 params.extra_ies_len = wpabuf_len(extra_ie);
1108 }
1109
1110 scan_params = &params;
1111
1112 scan:
1113 if (ssid || !wpa_s->first_sched_scan) {
1114 wpa_dbg(wpa_s, MSG_DEBUG,
1115 "Starting sched scan: interval %d timeout %d",
1116 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1117 } else {
1118 wpa_dbg(wpa_s, MSG_DEBUG,
1119 "Starting sched scan: interval %d (no timeout)",
1120 wpa_s->sched_scan_interval);
1121 }
1122
1123 ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1124 wpa_s->sched_scan_interval);
1125 wpabuf_free(extra_ie);
1126 os_free(params.filter_ssids);
1127 if (ret) {
1128 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1129 if (prev_state != wpa_s->wpa_state)
1130 wpa_supplicant_set_state(wpa_s, prev_state);
1131 return ret;
1132 }
1133
1134 /* If we have more SSIDs to scan, add a timeout so we scan them too */
1135 if (ssid || !wpa_s->first_sched_scan) {
1136 wpa_s->sched_scan_timed_out = 0;
1137 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1138 wpa_supplicant_sched_scan_timeout,
1139 wpa_s, NULL);
1140 wpa_s->first_sched_scan = 0;
1141 wpa_s->sched_scan_timeout /= 2;
1142 wpa_s->sched_scan_interval *= 2;
1143 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1144 wpa_s->sched_scan_interval = 10;
1145 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1146 }
1147 }
1148
1149 /* If there is no more ssids, start next time from the beginning */
1150 if (!ssid)
1151 wpa_s->prev_sched_ssid = NULL;
1152
1153 return 0;
1154 }
1155
1156
1157 /**
1158 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1159 * @wpa_s: Pointer to wpa_supplicant data
1160 *
1161 * This function is used to cancel a scan request scheduled with
1162 * wpa_supplicant_req_scan().
1163 */
1164 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1165 {
1166 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1167 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1168 wpas_p2p_continue_after_scan(wpa_s);
1169 }
1170
1171
1172 /**
1173 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1174 * @wpa_s: Pointer to wpa_supplicant data
1175 *
1176 * This function is used to stop a periodic scheduled scan.
1177 */
1178 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1179 {
1180 if (!wpa_s->sched_scanning)
1181 return;
1182
1183 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1184 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1185 wpa_supplicant_stop_sched_scan(wpa_s);
1186 }
1187
1188
1189 /**
1190 * wpa_supplicant_notify_scanning - Indicate possible scan state change
1191 * @wpa_s: Pointer to wpa_supplicant data
1192 * @scanning: Whether scanning is currently in progress
1193 *
1194 * This function is to generate scanning notifycations. It is called whenever
1195 * there may have been a change in scanning (scan started, completed, stopped).
1196 * wpas_notify_scanning() is called whenever the scanning state changed from the
1197 * previously notified state.
1198 */
1199 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1200 int scanning)
1201 {
1202 if (wpa_s->scanning != scanning) {
1203 wpa_s->scanning = scanning;
1204 wpas_notify_scanning(wpa_s);
1205 }
1206 }
1207
1208
1209 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1210 {
1211 int rate = 0;
1212 const u8 *ie;
1213 int i;
1214
1215 ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1216 for (i = 0; ie && i < ie[1]; i++) {
1217 if ((ie[i + 2] & 0x7f) > rate)
1218 rate = ie[i + 2] & 0x7f;
1219 }
1220
1221 ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1222 for (i = 0; ie && i < ie[1]; i++) {
1223 if ((ie[i + 2] & 0x7f) > rate)
1224 rate = ie[i + 2] & 0x7f;
1225 }
1226
1227 return rate;
1228 }
1229
1230
1231 /**
1232 * wpa_scan_get_ie - Fetch a specified information element from a scan result
1233 * @res: Scan result entry
1234 * @ie: Information element identitifier (WLAN_EID_*)
1235 * Returns: Pointer to the information element (id field) or %NULL if not found
1236 *
1237 * This function returns the first matching information element in the scan
1238 * result.
1239 */
1240 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1241 {
1242 const u8 *end, *pos;
1243
1244 pos = (const u8 *) (res + 1);
1245 end = pos + res->ie_len;
1246
1247 while (pos + 1 < end) {
1248 if (pos + 2 + pos[1] > end)
1249 break;
1250 if (pos[0] == ie)
1251 return pos;
1252 pos += 2 + pos[1];
1253 }
1254
1255 return NULL;
1256 }
1257
1258
1259 /**
1260 * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1261 * @res: Scan result entry
1262 * @vendor_type: Vendor type (four octets starting the IE payload)
1263 * Returns: Pointer to the information element (id field) or %NULL if not found
1264 *
1265 * This function returns the first matching information element in the scan
1266 * result.
1267 */
1268 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1269 u32 vendor_type)
1270 {
1271 const u8 *end, *pos;
1272
1273 pos = (const u8 *) (res + 1);
1274 end = pos + res->ie_len;
1275
1276 while (pos + 1 < end) {
1277 if (pos + 2 + pos[1] > end)
1278 break;
1279 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1280 vendor_type == WPA_GET_BE32(&pos[2]))
1281 return pos;
1282 pos += 2 + pos[1];
1283 }
1284
1285 return NULL;
1286 }
1287
1288
1289 /**
1290 * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1291 * @res: Scan result entry
1292 * @vendor_type: Vendor type (four octets starting the IE payload)
1293 * Returns: Pointer to the information element payload or %NULL if not found
1294 *
1295 * This function returns concatenated payload of possibly fragmented vendor
1296 * specific information elements in the scan result. The caller is responsible
1297 * for freeing the returned buffer.
1298 */
1299 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1300 u32 vendor_type)
1301 {
1302 struct wpabuf *buf;
1303 const u8 *end, *pos;
1304
1305 buf = wpabuf_alloc(res->ie_len);
1306 if (buf == NULL)
1307 return NULL;
1308
1309 pos = (const u8 *) (res + 1);
1310 end = pos + res->ie_len;
1311
1312 while (pos + 1 < end) {
1313 if (pos + 2 + pos[1] > end)
1314 break;
1315 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1316 vendor_type == WPA_GET_BE32(&pos[2]))
1317 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1318 pos += 2 + pos[1];
1319 }
1320
1321 if (wpabuf_len(buf) == 0) {
1322 wpabuf_free(buf);
1323 buf = NULL;
1324 }
1325
1326 return buf;
1327 }
1328
1329
1330 /*
1331 * Channels with a great SNR can operate at full rate. What is a great SNR?
1332 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1333 * rule of thumb is that any SNR above 20 is good." This one
1334 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1335 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1336 * conservative value.
1337 */
1338 #define GREAT_SNR 30
1339
1340 /* Compare function for sorting scan results. Return >0 if @b is considered
1341 * better. */
1342 static int wpa_scan_result_compar(const void *a, const void *b)
1343 {
1344 #define IS_5GHZ(n) (n > 4000)
1345 #define MIN(a,b) a < b ? a : b
1346 struct wpa_scan_res **_wa = (void *) a;
1347 struct wpa_scan_res **_wb = (void *) b;
1348 struct wpa_scan_res *wa = *_wa;
1349 struct wpa_scan_res *wb = *_wb;
1350 int wpa_a, wpa_b, maxrate_a, maxrate_b;
1351 int snr_a, snr_b;
1352
1353 /* WPA/WPA2 support preferred */
1354 wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1355 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1356 wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1357 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1358
1359 if (wpa_b && !wpa_a)
1360 return 1;
1361 if (!wpa_b && wpa_a)
1362 return -1;
1363
1364 /* privacy support preferred */
1365 if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1366 (wb->caps & IEEE80211_CAP_PRIVACY))
1367 return 1;
1368 if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1369 (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1370 return -1;
1371
1372 if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1373 !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1374 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1375 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1376 } else {
1377 /* Not suitable information to calculate SNR, so use level */
1378 snr_a = wa->level;
1379 snr_b = wb->level;
1380 }
1381
1382 /* best/max rate preferred if SNR close enough */
1383 if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1384 (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1385 maxrate_a = wpa_scan_get_max_rate(wa);
1386 maxrate_b = wpa_scan_get_max_rate(wb);
1387 if (maxrate_a != maxrate_b)
1388 return maxrate_b - maxrate_a;
1389 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1390 return IS_5GHZ(wa->freq) ? -1 : 1;
1391 }
1392
1393 /* use freq for channel preference */
1394
1395 /* all things being equal, use SNR; if SNRs are
1396 * identical, use quality values since some drivers may only report
1397 * that value and leave the signal level zero */
1398 if (snr_b == snr_a)
1399 return wb->qual - wa->qual;
1400 return snr_b - snr_a;
1401 #undef MIN
1402 #undef IS_5GHZ
1403 }
1404
1405
1406 #ifdef CONFIG_WPS
1407 /* Compare function for sorting scan results when searching a WPS AP for
1408 * provisioning. Return >0 if @b is considered better. */
1409 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1410 {
1411 struct wpa_scan_res **_wa = (void *) a;
1412 struct wpa_scan_res **_wb = (void *) b;
1413 struct wpa_scan_res *wa = *_wa;
1414 struct wpa_scan_res *wb = *_wb;
1415 int uses_wps_a, uses_wps_b;
1416 struct wpabuf *wps_a, *wps_b;
1417 int res;
1418
1419 /* Optimization - check WPS IE existence before allocated memory and
1420 * doing full reassembly. */
1421 uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1422 uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1423 if (uses_wps_a && !uses_wps_b)
1424 return -1;
1425 if (!uses_wps_a && uses_wps_b)
1426 return 1;
1427
1428 if (uses_wps_a && uses_wps_b) {
1429 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1430 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1431 res = wps_ap_priority_compar(wps_a, wps_b);
1432 wpabuf_free(wps_a);
1433 wpabuf_free(wps_b);
1434 if (res)
1435 return res;
1436 }
1437
1438 /*
1439 * Do not use current AP security policy as a sorting criteria during
1440 * WPS provisioning step since the AP may get reconfigured at the
1441 * completion of provisioning.
1442 */
1443
1444 /* all things being equal, use signal level; if signal levels are
1445 * identical, use quality values since some drivers may only report
1446 * that value and leave the signal level zero */
1447 if (wb->level == wa->level)
1448 return wb->qual - wa->qual;
1449 return wb->level - wa->level;
1450 }
1451 #endif /* CONFIG_WPS */
1452
1453
1454 static void dump_scan_res(struct wpa_scan_results *scan_res)
1455 {
1456 #ifndef CONFIG_NO_STDOUT_DEBUG
1457 size_t i;
1458
1459 if (scan_res->res == NULL || scan_res->num == 0)
1460 return;
1461
1462 wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1463
1464 for (i = 0; i < scan_res->num; i++) {
1465 struct wpa_scan_res *r = scan_res->res[i];
1466 u8 *pos;
1467 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1468 == WPA_SCAN_LEVEL_DBM) {
1469 int snr = r->level - r->noise;
1470 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1471 "noise=%d level=%d snr=%d%s flags=0x%x "
1472 "age=%u",
1473 MAC2STR(r->bssid), r->freq, r->qual,
1474 r->noise, r->level, snr,
1475 snr >= GREAT_SNR ? "*" : "", r->flags,
1476 r->age);
1477 } else {
1478 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1479 "noise=%d level=%d flags=0x%x age=%u",
1480 MAC2STR(r->bssid), r->freq, r->qual,
1481 r->noise, r->level, r->flags, r->age);
1482 }
1483 pos = (u8 *) (r + 1);
1484 if (r->ie_len)
1485 wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1486 pos += r->ie_len;
1487 if (r->beacon_ie_len)
1488 wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1489 pos, r->beacon_ie_len);
1490 }
1491 #endif /* CONFIG_NO_STDOUT_DEBUG */
1492 }
1493
1494
1495 /**
1496 * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1497 * @wpa_s: Pointer to wpa_supplicant data
1498 * @bssid: BSSID to check
1499 * Returns: 0 if the BSSID is filtered or 1 if not
1500 *
1501 * This function is used to filter out specific BSSIDs from scan reslts mainly
1502 * for testing purposes (SET bssid_filter ctrl_iface command).
1503 */
1504 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1505 const u8 *bssid)
1506 {
1507 size_t i;
1508
1509 if (wpa_s->bssid_filter == NULL)
1510 return 1;
1511
1512 for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1513 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1514 ETH_ALEN) == 0)
1515 return 1;
1516 }
1517
1518 return 0;
1519 }
1520
1521
1522 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1523 struct wpa_scan_results *res)
1524 {
1525 size_t i, j;
1526
1527 if (wpa_s->bssid_filter == NULL)
1528 return;
1529
1530 for (i = 0, j = 0; i < res->num; i++) {
1531 if (wpa_supplicant_filter_bssid_match(wpa_s,
1532 res->res[i]->bssid)) {
1533 res->res[j++] = res->res[i];
1534 } else {
1535 os_free(res->res[i]);
1536 res->res[i] = NULL;
1537 }
1538 }
1539
1540 if (res->num != j) {
1541 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1542 (int) (res->num - j));
1543 res->num = j;
1544 }
1545 }
1546
1547
1548 /**
1549 * wpa_supplicant_get_scan_results - Get scan results
1550 * @wpa_s: Pointer to wpa_supplicant data
1551 * @info: Information about what was scanned or %NULL if not available
1552 * @new_scan: Whether a new scan was performed
1553 * Returns: Scan results, %NULL on failure
1554 *
1555 * This function request the current scan results from the driver and updates
1556 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1557 * results with wpa_scan_results_free().
1558 */
1559 struct wpa_scan_results *
1560 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1561 struct scan_info *info, int new_scan)
1562 {
1563 struct wpa_scan_results *scan_res;
1564 size_t i;
1565 int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1566
1567 scan_res = wpa_drv_get_scan_results2(wpa_s);
1568 if (scan_res == NULL) {
1569 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1570 return NULL;
1571 }
1572 if (scan_res->fetch_time.sec == 0) {
1573 /*
1574 * Make sure we have a valid timestamp if the driver wrapper
1575 * does not set this.
1576 */
1577 os_get_time(&scan_res->fetch_time);
1578 }
1579 filter_scan_res(wpa_s, scan_res);
1580
1581 #ifdef CONFIG_WPS
1582 if (wpas_wps_in_progress(wpa_s)) {
1583 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1584 "provisioning rules");
1585 compar = wpa_scan_result_wps_compar;
1586 }
1587 #endif /* CONFIG_WPS */
1588
1589 qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1590 compar);
1591 dump_scan_res(scan_res);
1592
1593 wpa_bss_update_start(wpa_s);
1594 for (i = 0; i < scan_res->num; i++)
1595 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1596 &scan_res->fetch_time);
1597 wpa_bss_update_end(wpa_s, info, new_scan);
1598
1599 return scan_res;
1600 }
1601
1602
1603 /**
1604 * wpa_supplicant_update_scan_results - Update scan results from the driver
1605 * @wpa_s: Pointer to wpa_supplicant data
1606 * Returns: 0 on success, -1 on failure
1607 *
1608 * This function updates the BSS table within wpa_supplicant based on the
1609 * currently available scan results from the driver without requesting a new
1610 * scan. This is used in cases where the driver indicates an association
1611 * (including roaming within ESS) and wpa_supplicant does not yet have the
1612 * needed information to complete the connection (e.g., to perform validation
1613 * steps in 4-way handshake).
1614 */
1615 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1616 {
1617 struct wpa_scan_results *scan_res;
1618 scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1619 if (scan_res == NULL)
1620 return -1;
1621 wpa_scan_results_free(scan_res);
1622
1623 return 0;
1624 }
1625
1626
1627 /**
1628 * scan_only_handler - Reports scan results
1629 */
1630 void scan_only_handler(struct wpa_supplicant *wpa_s,
1631 struct wpa_scan_results *scan_res)
1632 {
1633 wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1634 wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1635 wpas_notify_scan_results(wpa_s);
1636 wpas_notify_scan_done(wpa_s, 1);
1637 }
1638
1639
1640 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1641 {
1642 return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1643 }
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