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