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[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / net / wireless / scan.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * cfg80211 scan result handling
4 *
5 * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
6 * Copyright 2013-2014 Intel Mobile Communications GmbH
7 * Copyright 2016 Intel Deutschland GmbH
8 */
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <linux/netdevice.h>
13 #include <linux/wireless.h>
14 #include <linux/nl80211.h>
15 #include <linux/etherdevice.h>
16 #include <net/arp.h>
17 #include <net/cfg80211.h>
18 #include <net/cfg80211-wext.h>
19 #include <net/iw_handler.h>
20 #include "core.h"
21 #include "nl80211.h"
22 #include "wext-compat.h"
23 #include "rdev-ops.h"
24
25 /**
26 * DOC: BSS tree/list structure
27 *
28 * At the top level, the BSS list is kept in both a list in each
29 * registered device (@bss_list) as well as an RB-tree for faster
30 * lookup. In the RB-tree, entries can be looked up using their
31 * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
32 * for other BSSes.
33 *
34 * Due to the possibility of hidden SSIDs, there's a second level
35 * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
36 * The hidden_list connects all BSSes belonging to a single AP
37 * that has a hidden SSID, and connects beacon and probe response
38 * entries. For a probe response entry for a hidden SSID, the
39 * hidden_beacon_bss pointer points to the BSS struct holding the
40 * beacon's information.
41 *
42 * Reference counting is done for all these references except for
43 * the hidden_list, so that a beacon BSS struct that is otherwise
44 * not referenced has one reference for being on the bss_list and
45 * one for each probe response entry that points to it using the
46 * hidden_beacon_bss pointer. When a BSS struct that has such a
47 * pointer is get/put, the refcount update is also propagated to
48 * the referenced struct, this ensure that it cannot get removed
49 * while somebody is using the probe response version.
50 *
51 * Note that the hidden_beacon_bss pointer never changes, due to
52 * the reference counting. Therefore, no locking is needed for
53 * it.
54 *
55 * Also note that the hidden_beacon_bss pointer is only relevant
56 * if the driver uses something other than the IEs, e.g. private
57 * data stored stored in the BSS struct, since the beacon IEs are
58 * also linked into the probe response struct.
59 */
60
61 /*
62 * Limit the number of BSS entries stored in mac80211. Each one is
63 * a bit over 4k at most, so this limits to roughly 4-5M of memory.
64 * If somebody wants to really attack this though, they'd likely
65 * use small beacons, and only one type of frame, limiting each of
66 * the entries to a much smaller size (in order to generate more
67 * entries in total, so overhead is bigger.)
68 */
69 static int bss_entries_limit = 1000;
70 module_param(bss_entries_limit, int, 0644);
71 MODULE_PARM_DESC(bss_entries_limit,
72 "limit to number of scan BSS entries (per wiphy, default 1000)");
73
74 #define IEEE80211_SCAN_RESULT_EXPIRE (7 * HZ)
75
76 static void bss_free(struct cfg80211_internal_bss *bss)
77 {
78 struct cfg80211_bss_ies *ies;
79
80 if (WARN_ON(atomic_read(&bss->hold)))
81 return;
82
83 ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
84 if (ies && !bss->pub.hidden_beacon_bss)
85 kfree_rcu(ies, rcu_head);
86 ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
87 if (ies)
88 kfree_rcu(ies, rcu_head);
89
90 /*
91 * This happens when the module is removed, it doesn't
92 * really matter any more save for completeness
93 */
94 if (!list_empty(&bss->hidden_list))
95 list_del(&bss->hidden_list);
96
97 kfree(bss);
98 }
99
100 static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
101 struct cfg80211_internal_bss *bss)
102 {
103 lockdep_assert_held(&rdev->bss_lock);
104
105 bss->refcount++;
106 if (bss->pub.hidden_beacon_bss) {
107 bss = container_of(bss->pub.hidden_beacon_bss,
108 struct cfg80211_internal_bss,
109 pub);
110 bss->refcount++;
111 }
112 }
113
114 static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
115 struct cfg80211_internal_bss *bss)
116 {
117 lockdep_assert_held(&rdev->bss_lock);
118
119 if (bss->pub.hidden_beacon_bss) {
120 struct cfg80211_internal_bss *hbss;
121 hbss = container_of(bss->pub.hidden_beacon_bss,
122 struct cfg80211_internal_bss,
123 pub);
124 hbss->refcount--;
125 if (hbss->refcount == 0)
126 bss_free(hbss);
127 }
128 bss->refcount--;
129 if (bss->refcount == 0)
130 bss_free(bss);
131 }
132
133 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
134 struct cfg80211_internal_bss *bss)
135 {
136 lockdep_assert_held(&rdev->bss_lock);
137
138 if (!list_empty(&bss->hidden_list)) {
139 /*
140 * don't remove the beacon entry if it has
141 * probe responses associated with it
142 */
143 if (!bss->pub.hidden_beacon_bss)
144 return false;
145 /*
146 * if it's a probe response entry break its
147 * link to the other entries in the group
148 */
149 list_del_init(&bss->hidden_list);
150 }
151
152 list_del_init(&bss->list);
153 rb_erase(&bss->rbn, &rdev->bss_tree);
154 rdev->bss_entries--;
155 WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list),
156 "rdev bss entries[%d]/list[empty:%d] corruption\n",
157 rdev->bss_entries, list_empty(&rdev->bss_list));
158 bss_ref_put(rdev, bss);
159 return true;
160 }
161
162 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
163 unsigned long expire_time)
164 {
165 struct cfg80211_internal_bss *bss, *tmp;
166 bool expired = false;
167
168 lockdep_assert_held(&rdev->bss_lock);
169
170 list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
171 if (atomic_read(&bss->hold))
172 continue;
173 if (!time_after(expire_time, bss->ts))
174 continue;
175
176 if (__cfg80211_unlink_bss(rdev, bss))
177 expired = true;
178 }
179
180 if (expired)
181 rdev->bss_generation++;
182 }
183
184 static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev)
185 {
186 struct cfg80211_internal_bss *bss, *oldest = NULL;
187 bool ret;
188
189 lockdep_assert_held(&rdev->bss_lock);
190
191 list_for_each_entry(bss, &rdev->bss_list, list) {
192 if (atomic_read(&bss->hold))
193 continue;
194
195 if (!list_empty(&bss->hidden_list) &&
196 !bss->pub.hidden_beacon_bss)
197 continue;
198
199 if (oldest && time_before(oldest->ts, bss->ts))
200 continue;
201 oldest = bss;
202 }
203
204 if (WARN_ON(!oldest))
205 return false;
206
207 /*
208 * The callers make sure to increase rdev->bss_generation if anything
209 * gets removed (and a new entry added), so there's no need to also do
210 * it here.
211 */
212
213 ret = __cfg80211_unlink_bss(rdev, oldest);
214 WARN_ON(!ret);
215 return ret;
216 }
217
218 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
219 bool send_message)
220 {
221 struct cfg80211_scan_request *request;
222 struct wireless_dev *wdev;
223 struct sk_buff *msg;
224 #ifdef CONFIG_CFG80211_WEXT
225 union iwreq_data wrqu;
226 #endif
227
228 ASSERT_RTNL();
229
230 if (rdev->scan_msg) {
231 nl80211_send_scan_msg(rdev, rdev->scan_msg);
232 rdev->scan_msg = NULL;
233 return;
234 }
235
236 request = rdev->scan_req;
237 if (!request)
238 return;
239
240 wdev = request->wdev;
241
242 /*
243 * This must be before sending the other events!
244 * Otherwise, wpa_supplicant gets completely confused with
245 * wext events.
246 */
247 if (wdev->netdev)
248 cfg80211_sme_scan_done(wdev->netdev);
249
250 if (!request->info.aborted &&
251 request->flags & NL80211_SCAN_FLAG_FLUSH) {
252 /* flush entries from previous scans */
253 spin_lock_bh(&rdev->bss_lock);
254 __cfg80211_bss_expire(rdev, request->scan_start);
255 spin_unlock_bh(&rdev->bss_lock);
256 }
257
258 msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted);
259
260 #ifdef CONFIG_CFG80211_WEXT
261 if (wdev->netdev && !request->info.aborted) {
262 memset(&wrqu, 0, sizeof(wrqu));
263
264 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
265 }
266 #endif
267
268 if (wdev->netdev)
269 dev_put(wdev->netdev);
270
271 rdev->scan_req = NULL;
272 kfree(request);
273
274 if (!send_message)
275 rdev->scan_msg = msg;
276 else
277 nl80211_send_scan_msg(rdev, msg);
278 }
279
280 void __cfg80211_scan_done(struct work_struct *wk)
281 {
282 struct cfg80211_registered_device *rdev;
283
284 rdev = container_of(wk, struct cfg80211_registered_device,
285 scan_done_wk);
286
287 rtnl_lock();
288 ___cfg80211_scan_done(rdev, true);
289 rtnl_unlock();
290 }
291
292 void cfg80211_scan_done(struct cfg80211_scan_request *request,
293 struct cfg80211_scan_info *info)
294 {
295 trace_cfg80211_scan_done(request, info);
296 WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req);
297
298 request->info = *info;
299 request->notified = true;
300 queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
301 }
302 EXPORT_SYMBOL(cfg80211_scan_done);
303
304 void cfg80211_add_sched_scan_req(struct cfg80211_registered_device *rdev,
305 struct cfg80211_sched_scan_request *req)
306 {
307 ASSERT_RTNL();
308
309 list_add_rcu(&req->list, &rdev->sched_scan_req_list);
310 }
311
312 static void cfg80211_del_sched_scan_req(struct cfg80211_registered_device *rdev,
313 struct cfg80211_sched_scan_request *req)
314 {
315 ASSERT_RTNL();
316
317 list_del_rcu(&req->list);
318 kfree_rcu(req, rcu_head);
319 }
320
321 static struct cfg80211_sched_scan_request *
322 cfg80211_find_sched_scan_req(struct cfg80211_registered_device *rdev, u64 reqid)
323 {
324 struct cfg80211_sched_scan_request *pos;
325
326 WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
327
328 list_for_each_entry_rcu(pos, &rdev->sched_scan_req_list, list) {
329 if (pos->reqid == reqid)
330 return pos;
331 }
332 return NULL;
333 }
334
335 /*
336 * Determines if a scheduled scan request can be handled. When a legacy
337 * scheduled scan is running no other scheduled scan is allowed regardless
338 * whether the request is for legacy or multi-support scan. When a multi-support
339 * scheduled scan is running a request for legacy scan is not allowed. In this
340 * case a request for multi-support scan can be handled if resources are
341 * available, ie. struct wiphy::max_sched_scan_reqs limit is not yet reached.
342 */
343 int cfg80211_sched_scan_req_possible(struct cfg80211_registered_device *rdev,
344 bool want_multi)
345 {
346 struct cfg80211_sched_scan_request *pos;
347 int i = 0;
348
349 list_for_each_entry(pos, &rdev->sched_scan_req_list, list) {
350 /* request id zero means legacy in progress */
351 if (!i && !pos->reqid)
352 return -EINPROGRESS;
353 i++;
354 }
355
356 if (i) {
357 /* no legacy allowed when multi request(s) are active */
358 if (!want_multi)
359 return -EINPROGRESS;
360
361 /* resource limit reached */
362 if (i == rdev->wiphy.max_sched_scan_reqs)
363 return -ENOSPC;
364 }
365 return 0;
366 }
367
368 void cfg80211_sched_scan_results_wk(struct work_struct *work)
369 {
370 struct cfg80211_registered_device *rdev;
371 struct cfg80211_sched_scan_request *req, *tmp;
372
373 rdev = container_of(work, struct cfg80211_registered_device,
374 sched_scan_res_wk);
375
376 rtnl_lock();
377 list_for_each_entry_safe(req, tmp, &rdev->sched_scan_req_list, list) {
378 if (req->report_results) {
379 req->report_results = false;
380 if (req->flags & NL80211_SCAN_FLAG_FLUSH) {
381 /* flush entries from previous scans */
382 spin_lock_bh(&rdev->bss_lock);
383 __cfg80211_bss_expire(rdev, req->scan_start);
384 spin_unlock_bh(&rdev->bss_lock);
385 req->scan_start = jiffies;
386 }
387 nl80211_send_sched_scan(req,
388 NL80211_CMD_SCHED_SCAN_RESULTS);
389 }
390 }
391 rtnl_unlock();
392 }
393
394 void cfg80211_sched_scan_results(struct wiphy *wiphy, u64 reqid)
395 {
396 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
397 struct cfg80211_sched_scan_request *request;
398
399 trace_cfg80211_sched_scan_results(wiphy, reqid);
400 /* ignore if we're not scanning */
401
402 rcu_read_lock();
403 request = cfg80211_find_sched_scan_req(rdev, reqid);
404 if (request) {
405 request->report_results = true;
406 queue_work(cfg80211_wq, &rdev->sched_scan_res_wk);
407 }
408 rcu_read_unlock();
409 }
410 EXPORT_SYMBOL(cfg80211_sched_scan_results);
411
412 void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy, u64 reqid)
413 {
414 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
415
416 ASSERT_RTNL();
417
418 trace_cfg80211_sched_scan_stopped(wiphy, reqid);
419
420 __cfg80211_stop_sched_scan(rdev, reqid, true);
421 }
422 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
423
424 void cfg80211_sched_scan_stopped(struct wiphy *wiphy, u64 reqid)
425 {
426 rtnl_lock();
427 cfg80211_sched_scan_stopped_rtnl(wiphy, reqid);
428 rtnl_unlock();
429 }
430 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
431
432 int cfg80211_stop_sched_scan_req(struct cfg80211_registered_device *rdev,
433 struct cfg80211_sched_scan_request *req,
434 bool driver_initiated)
435 {
436 ASSERT_RTNL();
437
438 if (!driver_initiated) {
439 int err = rdev_sched_scan_stop(rdev, req->dev, req->reqid);
440 if (err)
441 return err;
442 }
443
444 nl80211_send_sched_scan(req, NL80211_CMD_SCHED_SCAN_STOPPED);
445
446 cfg80211_del_sched_scan_req(rdev, req);
447
448 return 0;
449 }
450
451 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
452 u64 reqid, bool driver_initiated)
453 {
454 struct cfg80211_sched_scan_request *sched_scan_req;
455
456 ASSERT_RTNL();
457
458 sched_scan_req = cfg80211_find_sched_scan_req(rdev, reqid);
459 if (!sched_scan_req)
460 return -ENOENT;
461
462 return cfg80211_stop_sched_scan_req(rdev, sched_scan_req,
463 driver_initiated);
464 }
465
466 void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
467 unsigned long age_secs)
468 {
469 struct cfg80211_internal_bss *bss;
470 unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
471
472 spin_lock_bh(&rdev->bss_lock);
473 list_for_each_entry(bss, &rdev->bss_list, list)
474 bss->ts -= age_jiffies;
475 spin_unlock_bh(&rdev->bss_lock);
476 }
477
478 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
479 {
480 __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
481 }
482
483 const u8 *cfg80211_find_ie_match(u8 eid, const u8 *ies, int len,
484 const u8 *match, int match_len,
485 int match_offset)
486 {
487 /* match_offset can't be smaller than 2, unless match_len is
488 * zero, in which case match_offset must be zero as well.
489 */
490 if (WARN_ON((match_len && match_offset < 2) ||
491 (!match_len && match_offset)))
492 return NULL;
493
494 while (len >= 2 && len >= ies[1] + 2) {
495 if ((ies[0] == eid) &&
496 (ies[1] + 2 >= match_offset + match_len) &&
497 !memcmp(ies + match_offset, match, match_len))
498 return ies;
499
500 len -= ies[1] + 2;
501 ies += ies[1] + 2;
502 }
503
504 return NULL;
505 }
506 EXPORT_SYMBOL(cfg80211_find_ie_match);
507
508 const u8 *cfg80211_find_vendor_ie(unsigned int oui, int oui_type,
509 const u8 *ies, int len)
510 {
511 const u8 *ie;
512 u8 match[] = { oui >> 16, oui >> 8, oui, oui_type };
513 int match_len = (oui_type < 0) ? 3 : sizeof(match);
514
515 if (WARN_ON(oui_type > 0xff))
516 return NULL;
517
518 ie = cfg80211_find_ie_match(WLAN_EID_VENDOR_SPECIFIC, ies, len,
519 match, match_len, 2);
520
521 if (ie && (ie[1] < 4))
522 return NULL;
523
524 return ie;
525 }
526 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
527
528 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
529 const u8 *ssid, size_t ssid_len)
530 {
531 const struct cfg80211_bss_ies *ies;
532 const u8 *ssidie;
533
534 if (bssid && !ether_addr_equal(a->bssid, bssid))
535 return false;
536
537 if (!ssid)
538 return true;
539
540 ies = rcu_access_pointer(a->ies);
541 if (!ies)
542 return false;
543 ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
544 if (!ssidie)
545 return false;
546 if (ssidie[1] != ssid_len)
547 return false;
548 return memcmp(ssidie + 2, ssid, ssid_len) == 0;
549 }
550
551 /**
552 * enum bss_compare_mode - BSS compare mode
553 * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
554 * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
555 * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
556 */
557 enum bss_compare_mode {
558 BSS_CMP_REGULAR,
559 BSS_CMP_HIDE_ZLEN,
560 BSS_CMP_HIDE_NUL,
561 };
562
563 static int cmp_bss(struct cfg80211_bss *a,
564 struct cfg80211_bss *b,
565 enum bss_compare_mode mode)
566 {
567 const struct cfg80211_bss_ies *a_ies, *b_ies;
568 const u8 *ie1 = NULL;
569 const u8 *ie2 = NULL;
570 int i, r;
571
572 if (a->channel != b->channel)
573 return b->channel->center_freq - a->channel->center_freq;
574
575 a_ies = rcu_access_pointer(a->ies);
576 if (!a_ies)
577 return -1;
578 b_ies = rcu_access_pointer(b->ies);
579 if (!b_ies)
580 return 1;
581
582 if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
583 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
584 a_ies->data, a_ies->len);
585 if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
586 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
587 b_ies->data, b_ies->len);
588 if (ie1 && ie2) {
589 int mesh_id_cmp;
590
591 if (ie1[1] == ie2[1])
592 mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
593 else
594 mesh_id_cmp = ie2[1] - ie1[1];
595
596 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
597 a_ies->data, a_ies->len);
598 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
599 b_ies->data, b_ies->len);
600 if (ie1 && ie2) {
601 if (mesh_id_cmp)
602 return mesh_id_cmp;
603 if (ie1[1] != ie2[1])
604 return ie2[1] - ie1[1];
605 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
606 }
607 }
608
609 r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
610 if (r)
611 return r;
612
613 ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
614 ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
615
616 if (!ie1 && !ie2)
617 return 0;
618
619 /*
620 * Note that with "hide_ssid", the function returns a match if
621 * the already-present BSS ("b") is a hidden SSID beacon for
622 * the new BSS ("a").
623 */
624
625 /* sort missing IE before (left of) present IE */
626 if (!ie1)
627 return -1;
628 if (!ie2)
629 return 1;
630
631 switch (mode) {
632 case BSS_CMP_HIDE_ZLEN:
633 /*
634 * In ZLEN mode we assume the BSS entry we're
635 * looking for has a zero-length SSID. So if
636 * the one we're looking at right now has that,
637 * return 0. Otherwise, return the difference
638 * in length, but since we're looking for the
639 * 0-length it's really equivalent to returning
640 * the length of the one we're looking at.
641 *
642 * No content comparison is needed as we assume
643 * the content length is zero.
644 */
645 return ie2[1];
646 case BSS_CMP_REGULAR:
647 default:
648 /* sort by length first, then by contents */
649 if (ie1[1] != ie2[1])
650 return ie2[1] - ie1[1];
651 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
652 case BSS_CMP_HIDE_NUL:
653 if (ie1[1] != ie2[1])
654 return ie2[1] - ie1[1];
655 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
656 for (i = 0; i < ie2[1]; i++)
657 if (ie2[i + 2])
658 return -1;
659 return 0;
660 }
661 }
662
663 static bool cfg80211_bss_type_match(u16 capability,
664 enum nl80211_band band,
665 enum ieee80211_bss_type bss_type)
666 {
667 bool ret = true;
668 u16 mask, val;
669
670 if (bss_type == IEEE80211_BSS_TYPE_ANY)
671 return ret;
672
673 if (band == NL80211_BAND_60GHZ) {
674 mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
675 switch (bss_type) {
676 case IEEE80211_BSS_TYPE_ESS:
677 val = WLAN_CAPABILITY_DMG_TYPE_AP;
678 break;
679 case IEEE80211_BSS_TYPE_PBSS:
680 val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
681 break;
682 case IEEE80211_BSS_TYPE_IBSS:
683 val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
684 break;
685 default:
686 return false;
687 }
688 } else {
689 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
690 switch (bss_type) {
691 case IEEE80211_BSS_TYPE_ESS:
692 val = WLAN_CAPABILITY_ESS;
693 break;
694 case IEEE80211_BSS_TYPE_IBSS:
695 val = WLAN_CAPABILITY_IBSS;
696 break;
697 case IEEE80211_BSS_TYPE_MBSS:
698 val = 0;
699 break;
700 default:
701 return false;
702 }
703 }
704
705 ret = ((capability & mask) == val);
706 return ret;
707 }
708
709 /* Returned bss is reference counted and must be cleaned up appropriately. */
710 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
711 struct ieee80211_channel *channel,
712 const u8 *bssid,
713 const u8 *ssid, size_t ssid_len,
714 enum ieee80211_bss_type bss_type,
715 enum ieee80211_privacy privacy)
716 {
717 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
718 struct cfg80211_internal_bss *bss, *res = NULL;
719 unsigned long now = jiffies;
720 int bss_privacy;
721
722 trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
723 privacy);
724
725 spin_lock_bh(&rdev->bss_lock);
726
727 list_for_each_entry(bss, &rdev->bss_list, list) {
728 if (!cfg80211_bss_type_match(bss->pub.capability,
729 bss->pub.channel->band, bss_type))
730 continue;
731
732 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
733 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
734 (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
735 continue;
736 if (channel && bss->pub.channel != channel)
737 continue;
738 if (!is_valid_ether_addr(bss->pub.bssid))
739 continue;
740 /* Don't get expired BSS structs */
741 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
742 !atomic_read(&bss->hold))
743 continue;
744 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
745 res = bss;
746 bss_ref_get(rdev, res);
747 break;
748 }
749 }
750
751 spin_unlock_bh(&rdev->bss_lock);
752 if (!res)
753 return NULL;
754 trace_cfg80211_return_bss(&res->pub);
755 return &res->pub;
756 }
757 EXPORT_SYMBOL(cfg80211_get_bss);
758
759 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
760 struct cfg80211_internal_bss *bss)
761 {
762 struct rb_node **p = &rdev->bss_tree.rb_node;
763 struct rb_node *parent = NULL;
764 struct cfg80211_internal_bss *tbss;
765 int cmp;
766
767 while (*p) {
768 parent = *p;
769 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
770
771 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
772
773 if (WARN_ON(!cmp)) {
774 /* will sort of leak this BSS */
775 return;
776 }
777
778 if (cmp < 0)
779 p = &(*p)->rb_left;
780 else
781 p = &(*p)->rb_right;
782 }
783
784 rb_link_node(&bss->rbn, parent, p);
785 rb_insert_color(&bss->rbn, &rdev->bss_tree);
786 }
787
788 static struct cfg80211_internal_bss *
789 rb_find_bss(struct cfg80211_registered_device *rdev,
790 struct cfg80211_internal_bss *res,
791 enum bss_compare_mode mode)
792 {
793 struct rb_node *n = rdev->bss_tree.rb_node;
794 struct cfg80211_internal_bss *bss;
795 int r;
796
797 while (n) {
798 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
799 r = cmp_bss(&res->pub, &bss->pub, mode);
800
801 if (r == 0)
802 return bss;
803 else if (r < 0)
804 n = n->rb_left;
805 else
806 n = n->rb_right;
807 }
808
809 return NULL;
810 }
811
812 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
813 struct cfg80211_internal_bss *new)
814 {
815 const struct cfg80211_bss_ies *ies;
816 struct cfg80211_internal_bss *bss;
817 const u8 *ie;
818 int i, ssidlen;
819 u8 fold = 0;
820 u32 n_entries = 0;
821
822 ies = rcu_access_pointer(new->pub.beacon_ies);
823 if (WARN_ON(!ies))
824 return false;
825
826 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
827 if (!ie) {
828 /* nothing to do */
829 return true;
830 }
831
832 ssidlen = ie[1];
833 for (i = 0; i < ssidlen; i++)
834 fold |= ie[2 + i];
835
836 if (fold) {
837 /* not a hidden SSID */
838 return true;
839 }
840
841 /* This is the bad part ... */
842
843 list_for_each_entry(bss, &rdev->bss_list, list) {
844 /*
845 * we're iterating all the entries anyway, so take the
846 * opportunity to validate the list length accounting
847 */
848 n_entries++;
849
850 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
851 continue;
852 if (bss->pub.channel != new->pub.channel)
853 continue;
854 if (bss->pub.scan_width != new->pub.scan_width)
855 continue;
856 if (rcu_access_pointer(bss->pub.beacon_ies))
857 continue;
858 ies = rcu_access_pointer(bss->pub.ies);
859 if (!ies)
860 continue;
861 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
862 if (!ie)
863 continue;
864 if (ssidlen && ie[1] != ssidlen)
865 continue;
866 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
867 continue;
868 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
869 list_del(&bss->hidden_list);
870 /* combine them */
871 list_add(&bss->hidden_list, &new->hidden_list);
872 bss->pub.hidden_beacon_bss = &new->pub;
873 new->refcount += bss->refcount;
874 rcu_assign_pointer(bss->pub.beacon_ies,
875 new->pub.beacon_ies);
876 }
877
878 WARN_ONCE(n_entries != rdev->bss_entries,
879 "rdev bss entries[%d]/list[len:%d] corruption\n",
880 rdev->bss_entries, n_entries);
881
882 return true;
883 }
884
885 /* Returned bss is reference counted and must be cleaned up appropriately. */
886 static struct cfg80211_internal_bss *
887 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
888 struct cfg80211_internal_bss *tmp,
889 bool signal_valid)
890 {
891 struct cfg80211_internal_bss *found = NULL;
892
893 if (WARN_ON(!tmp->pub.channel))
894 return NULL;
895
896 tmp->ts = jiffies;
897
898 spin_lock_bh(&rdev->bss_lock);
899
900 if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
901 spin_unlock_bh(&rdev->bss_lock);
902 return NULL;
903 }
904
905 found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
906
907 if (found) {
908 /* Update IEs */
909 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
910 const struct cfg80211_bss_ies *old;
911
912 old = rcu_access_pointer(found->pub.proberesp_ies);
913
914 rcu_assign_pointer(found->pub.proberesp_ies,
915 tmp->pub.proberesp_ies);
916 /* Override possible earlier Beacon frame IEs */
917 rcu_assign_pointer(found->pub.ies,
918 tmp->pub.proberesp_ies);
919 if (old)
920 kfree_rcu((struct cfg80211_bss_ies *)old,
921 rcu_head);
922 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
923 const struct cfg80211_bss_ies *old;
924 struct cfg80211_internal_bss *bss;
925
926 if (found->pub.hidden_beacon_bss &&
927 !list_empty(&found->hidden_list)) {
928 const struct cfg80211_bss_ies *f;
929
930 /*
931 * The found BSS struct is one of the probe
932 * response members of a group, but we're
933 * receiving a beacon (beacon_ies in the tmp
934 * bss is used). This can only mean that the
935 * AP changed its beacon from not having an
936 * SSID to showing it, which is confusing so
937 * drop this information.
938 */
939
940 f = rcu_access_pointer(tmp->pub.beacon_ies);
941 kfree_rcu((struct cfg80211_bss_ies *)f,
942 rcu_head);
943 goto drop;
944 }
945
946 old = rcu_access_pointer(found->pub.beacon_ies);
947
948 rcu_assign_pointer(found->pub.beacon_ies,
949 tmp->pub.beacon_ies);
950
951 /* Override IEs if they were from a beacon before */
952 if (old == rcu_access_pointer(found->pub.ies))
953 rcu_assign_pointer(found->pub.ies,
954 tmp->pub.beacon_ies);
955
956 /* Assign beacon IEs to all sub entries */
957 list_for_each_entry(bss, &found->hidden_list,
958 hidden_list) {
959 const struct cfg80211_bss_ies *ies;
960
961 ies = rcu_access_pointer(bss->pub.beacon_ies);
962 WARN_ON(ies != old);
963
964 rcu_assign_pointer(bss->pub.beacon_ies,
965 tmp->pub.beacon_ies);
966 }
967
968 if (old)
969 kfree_rcu((struct cfg80211_bss_ies *)old,
970 rcu_head);
971 }
972
973 found->pub.beacon_interval = tmp->pub.beacon_interval;
974 /*
975 * don't update the signal if beacon was heard on
976 * adjacent channel.
977 */
978 if (signal_valid)
979 found->pub.signal = tmp->pub.signal;
980 found->pub.capability = tmp->pub.capability;
981 found->ts = tmp->ts;
982 found->ts_boottime = tmp->ts_boottime;
983 found->parent_tsf = tmp->parent_tsf;
984 ether_addr_copy(found->parent_bssid, tmp->parent_bssid);
985 } else {
986 struct cfg80211_internal_bss *new;
987 struct cfg80211_internal_bss *hidden;
988 struct cfg80211_bss_ies *ies;
989
990 /*
991 * create a copy -- the "res" variable that is passed in
992 * is allocated on the stack since it's not needed in the
993 * more common case of an update
994 */
995 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
996 GFP_ATOMIC);
997 if (!new) {
998 ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
999 if (ies)
1000 kfree_rcu(ies, rcu_head);
1001 ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
1002 if (ies)
1003 kfree_rcu(ies, rcu_head);
1004 goto drop;
1005 }
1006 memcpy(new, tmp, sizeof(*new));
1007 new->refcount = 1;
1008 INIT_LIST_HEAD(&new->hidden_list);
1009
1010 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
1011 hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
1012 if (!hidden)
1013 hidden = rb_find_bss(rdev, tmp,
1014 BSS_CMP_HIDE_NUL);
1015 if (hidden) {
1016 new->pub.hidden_beacon_bss = &hidden->pub;
1017 list_add(&new->hidden_list,
1018 &hidden->hidden_list);
1019 hidden->refcount++;
1020 rcu_assign_pointer(new->pub.beacon_ies,
1021 hidden->pub.beacon_ies);
1022 }
1023 } else {
1024 /*
1025 * Ok so we found a beacon, and don't have an entry. If
1026 * it's a beacon with hidden SSID, we might be in for an
1027 * expensive search for any probe responses that should
1028 * be grouped with this beacon for updates ...
1029 */
1030 if (!cfg80211_combine_bsses(rdev, new)) {
1031 kfree(new);
1032 goto drop;
1033 }
1034 }
1035
1036 if (rdev->bss_entries >= bss_entries_limit &&
1037 !cfg80211_bss_expire_oldest(rdev)) {
1038 kfree(new);
1039 goto drop;
1040 }
1041
1042 list_add_tail(&new->list, &rdev->bss_list);
1043 rdev->bss_entries++;
1044 rb_insert_bss(rdev, new);
1045 found = new;
1046 }
1047
1048 rdev->bss_generation++;
1049 bss_ref_get(rdev, found);
1050 spin_unlock_bh(&rdev->bss_lock);
1051
1052 return found;
1053 drop:
1054 spin_unlock_bh(&rdev->bss_lock);
1055 return NULL;
1056 }
1057
1058 /*
1059 * Update RX channel information based on the available frame payload
1060 * information. This is mainly for the 2.4 GHz band where frames can be received
1061 * from neighboring channels and the Beacon frames use the DSSS Parameter Set
1062 * element to indicate the current (transmitting) channel, but this might also
1063 * be needed on other bands if RX frequency does not match with the actual
1064 * operating channel of a BSS.
1065 */
1066 static struct ieee80211_channel *
1067 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
1068 struct ieee80211_channel *channel,
1069 enum nl80211_bss_scan_width scan_width)
1070 {
1071 const u8 *tmp;
1072 u32 freq;
1073 int channel_number = -1;
1074 struct ieee80211_channel *alt_channel;
1075
1076 tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
1077 if (tmp && tmp[1] == 1) {
1078 channel_number = tmp[2];
1079 } else {
1080 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
1081 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
1082 struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
1083
1084 channel_number = htop->primary_chan;
1085 }
1086 }
1087
1088 if (channel_number < 0) {
1089 /* No channel information in frame payload */
1090 return channel;
1091 }
1092
1093 freq = ieee80211_channel_to_frequency(channel_number, channel->band);
1094 alt_channel = ieee80211_get_channel(wiphy, freq);
1095 if (!alt_channel) {
1096 if (channel->band == NL80211_BAND_2GHZ) {
1097 /*
1098 * Better not allow unexpected channels when that could
1099 * be going beyond the 1-11 range (e.g., discovering
1100 * BSS on channel 12 when radio is configured for
1101 * channel 11.
1102 */
1103 return NULL;
1104 }
1105
1106 /* No match for the payload channel number - ignore it */
1107 return channel;
1108 }
1109
1110 if (scan_width == NL80211_BSS_CHAN_WIDTH_10 ||
1111 scan_width == NL80211_BSS_CHAN_WIDTH_5) {
1112 /*
1113 * Ignore channel number in 5 and 10 MHz channels where there
1114 * may not be an n:1 or 1:n mapping between frequencies and
1115 * channel numbers.
1116 */
1117 return channel;
1118 }
1119
1120 /*
1121 * Use the channel determined through the payload channel number
1122 * instead of the RX channel reported by the driver.
1123 */
1124 if (alt_channel->flags & IEEE80211_CHAN_DISABLED)
1125 return NULL;
1126 return alt_channel;
1127 }
1128
1129 /* Returned bss is reference counted and must be cleaned up appropriately. */
1130 struct cfg80211_bss *
1131 cfg80211_inform_bss_data(struct wiphy *wiphy,
1132 struct cfg80211_inform_bss *data,
1133 enum cfg80211_bss_frame_type ftype,
1134 const u8 *bssid, u64 tsf, u16 capability,
1135 u16 beacon_interval, const u8 *ie, size_t ielen,
1136 gfp_t gfp)
1137 {
1138 struct cfg80211_bss_ies *ies;
1139 struct ieee80211_channel *channel;
1140 struct cfg80211_internal_bss tmp = {}, *res;
1141 int bss_type;
1142 bool signal_valid;
1143
1144 if (WARN_ON(!wiphy))
1145 return NULL;
1146
1147 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1148 (data->signal < 0 || data->signal > 100)))
1149 return NULL;
1150
1151 channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan,
1152 data->scan_width);
1153 if (!channel)
1154 return NULL;
1155
1156 memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
1157 tmp.pub.channel = channel;
1158 tmp.pub.scan_width = data->scan_width;
1159 tmp.pub.signal = data->signal;
1160 tmp.pub.beacon_interval = beacon_interval;
1161 tmp.pub.capability = capability;
1162 tmp.ts_boottime = data->boottime_ns;
1163
1164 /*
1165 * If we do not know here whether the IEs are from a Beacon or Probe
1166 * Response frame, we need to pick one of the options and only use it
1167 * with the driver that does not provide the full Beacon/Probe Response
1168 * frame. Use Beacon frame pointer to avoid indicating that this should
1169 * override the IEs pointer should we have received an earlier
1170 * indication of Probe Response data.
1171 */
1172 ies = kzalloc(sizeof(*ies) + ielen, gfp);
1173 if (!ies)
1174 return NULL;
1175 ies->len = ielen;
1176 ies->tsf = tsf;
1177 ies->from_beacon = false;
1178 memcpy(ies->data, ie, ielen);
1179
1180 switch (ftype) {
1181 case CFG80211_BSS_FTYPE_BEACON:
1182 ies->from_beacon = true;
1183 /* fall through to assign */
1184 case CFG80211_BSS_FTYPE_UNKNOWN:
1185 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1186 break;
1187 case CFG80211_BSS_FTYPE_PRESP:
1188 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1189 break;
1190 }
1191 rcu_assign_pointer(tmp.pub.ies, ies);
1192
1193 signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1194 wiphy->max_adj_channel_rssi_comp;
1195 res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1196 if (!res)
1197 return NULL;
1198
1199 if (channel->band == NL80211_BAND_60GHZ) {
1200 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1201 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1202 bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1203 regulatory_hint_found_beacon(wiphy, channel, gfp);
1204 } else {
1205 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1206 regulatory_hint_found_beacon(wiphy, channel, gfp);
1207 }
1208
1209 trace_cfg80211_return_bss(&res->pub);
1210 /* cfg80211_bss_update gives us a referenced result */
1211 return &res->pub;
1212 }
1213 EXPORT_SYMBOL(cfg80211_inform_bss_data);
1214
1215 /* cfg80211_inform_bss_width_frame helper */
1216 struct cfg80211_bss *
1217 cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
1218 struct cfg80211_inform_bss *data,
1219 struct ieee80211_mgmt *mgmt, size_t len,
1220 gfp_t gfp)
1221
1222 {
1223 struct cfg80211_internal_bss tmp = {}, *res;
1224 struct cfg80211_bss_ies *ies;
1225 struct ieee80211_channel *channel;
1226 bool signal_valid;
1227 size_t ielen = len - offsetof(struct ieee80211_mgmt,
1228 u.probe_resp.variable);
1229 int bss_type;
1230
1231 BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
1232 offsetof(struct ieee80211_mgmt, u.beacon.variable));
1233
1234 trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);
1235
1236 if (WARN_ON(!mgmt))
1237 return NULL;
1238
1239 if (WARN_ON(!wiphy))
1240 return NULL;
1241
1242 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1243 (data->signal < 0 || data->signal > 100)))
1244 return NULL;
1245
1246 if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
1247 return NULL;
1248
1249 channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
1250 ielen, data->chan, data->scan_width);
1251 if (!channel)
1252 return NULL;
1253
1254 ies = kzalloc(sizeof(*ies) + ielen, gfp);
1255 if (!ies)
1256 return NULL;
1257 ies->len = ielen;
1258 ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1259 ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1260 memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1261
1262 if (ieee80211_is_probe_resp(mgmt->frame_control))
1263 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1264 else
1265 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1266 rcu_assign_pointer(tmp.pub.ies, ies);
1267
1268 memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1269 tmp.pub.channel = channel;
1270 tmp.pub.scan_width = data->scan_width;
1271 tmp.pub.signal = data->signal;
1272 tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1273 tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1274 tmp.ts_boottime = data->boottime_ns;
1275 tmp.parent_tsf = data->parent_tsf;
1276 ether_addr_copy(tmp.parent_bssid, data->parent_bssid);
1277
1278 signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1279 wiphy->max_adj_channel_rssi_comp;
1280 res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1281 if (!res)
1282 return NULL;
1283
1284 if (channel->band == NL80211_BAND_60GHZ) {
1285 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1286 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1287 bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1288 regulatory_hint_found_beacon(wiphy, channel, gfp);
1289 } else {
1290 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1291 regulatory_hint_found_beacon(wiphy, channel, gfp);
1292 }
1293
1294 trace_cfg80211_return_bss(&res->pub);
1295 /* cfg80211_bss_update gives us a referenced result */
1296 return &res->pub;
1297 }
1298 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
1299
1300 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1301 {
1302 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1303 struct cfg80211_internal_bss *bss;
1304
1305 if (!pub)
1306 return;
1307
1308 bss = container_of(pub, struct cfg80211_internal_bss, pub);
1309
1310 spin_lock_bh(&rdev->bss_lock);
1311 bss_ref_get(rdev, bss);
1312 spin_unlock_bh(&rdev->bss_lock);
1313 }
1314 EXPORT_SYMBOL(cfg80211_ref_bss);
1315
1316 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1317 {
1318 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1319 struct cfg80211_internal_bss *bss;
1320
1321 if (!pub)
1322 return;
1323
1324 bss = container_of(pub, struct cfg80211_internal_bss, pub);
1325
1326 spin_lock_bh(&rdev->bss_lock);
1327 bss_ref_put(rdev, bss);
1328 spin_unlock_bh(&rdev->bss_lock);
1329 }
1330 EXPORT_SYMBOL(cfg80211_put_bss);
1331
1332 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1333 {
1334 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1335 struct cfg80211_internal_bss *bss;
1336
1337 if (WARN_ON(!pub))
1338 return;
1339
1340 bss = container_of(pub, struct cfg80211_internal_bss, pub);
1341
1342 spin_lock_bh(&rdev->bss_lock);
1343 if (!list_empty(&bss->list)) {
1344 if (__cfg80211_unlink_bss(rdev, bss))
1345 rdev->bss_generation++;
1346 }
1347 spin_unlock_bh(&rdev->bss_lock);
1348 }
1349 EXPORT_SYMBOL(cfg80211_unlink_bss);
1350
1351 #ifdef CONFIG_CFG80211_WEXT
1352 static struct cfg80211_registered_device *
1353 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1354 {
1355 struct cfg80211_registered_device *rdev;
1356 struct net_device *dev;
1357
1358 ASSERT_RTNL();
1359
1360 dev = dev_get_by_index(net, ifindex);
1361 if (!dev)
1362 return ERR_PTR(-ENODEV);
1363 if (dev->ieee80211_ptr)
1364 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1365 else
1366 rdev = ERR_PTR(-ENODEV);
1367 dev_put(dev);
1368 return rdev;
1369 }
1370
1371 int cfg80211_wext_siwscan(struct net_device *dev,
1372 struct iw_request_info *info,
1373 union iwreq_data *wrqu, char *extra)
1374 {
1375 struct cfg80211_registered_device *rdev;
1376 struct wiphy *wiphy;
1377 struct iw_scan_req *wreq = NULL;
1378 struct cfg80211_scan_request *creq = NULL;
1379 int i, err, n_channels = 0;
1380 enum nl80211_band band;
1381
1382 if (!netif_running(dev))
1383 return -ENETDOWN;
1384
1385 if (wrqu->data.length == sizeof(struct iw_scan_req))
1386 wreq = (struct iw_scan_req *)extra;
1387
1388 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1389
1390 if (IS_ERR(rdev))
1391 return PTR_ERR(rdev);
1392
1393 if (rdev->scan_req || rdev->scan_msg) {
1394 err = -EBUSY;
1395 goto out;
1396 }
1397
1398 wiphy = &rdev->wiphy;
1399
1400 /* Determine number of channels, needed to allocate creq */
1401 if (wreq && wreq->num_channels)
1402 n_channels = wreq->num_channels;
1403 else
1404 n_channels = ieee80211_get_num_supported_channels(wiphy);
1405
1406 creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1407 n_channels * sizeof(void *),
1408 GFP_ATOMIC);
1409 if (!creq) {
1410 err = -ENOMEM;
1411 goto out;
1412 }
1413
1414 creq->wiphy = wiphy;
1415 creq->wdev = dev->ieee80211_ptr;
1416 /* SSIDs come after channels */
1417 creq->ssids = (void *)&creq->channels[n_channels];
1418 creq->n_channels = n_channels;
1419 creq->n_ssids = 1;
1420 creq->scan_start = jiffies;
1421
1422 /* translate "Scan on frequencies" request */
1423 i = 0;
1424 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1425 int j;
1426
1427 if (!wiphy->bands[band])
1428 continue;
1429
1430 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1431 /* ignore disabled channels */
1432 if (wiphy->bands[band]->channels[j].flags &
1433 IEEE80211_CHAN_DISABLED)
1434 continue;
1435
1436 /* If we have a wireless request structure and the
1437 * wireless request specifies frequencies, then search
1438 * for the matching hardware channel.
1439 */
1440 if (wreq && wreq->num_channels) {
1441 int k;
1442 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1443 for (k = 0; k < wreq->num_channels; k++) {
1444 struct iw_freq *freq =
1445 &wreq->channel_list[k];
1446 int wext_freq =
1447 cfg80211_wext_freq(freq);
1448
1449 if (wext_freq == wiphy_freq)
1450 goto wext_freq_found;
1451 }
1452 goto wext_freq_not_found;
1453 }
1454
1455 wext_freq_found:
1456 creq->channels[i] = &wiphy->bands[band]->channels[j];
1457 i++;
1458 wext_freq_not_found: ;
1459 }
1460 }
1461 /* No channels found? */
1462 if (!i) {
1463 err = -EINVAL;
1464 goto out;
1465 }
1466
1467 /* Set real number of channels specified in creq->channels[] */
1468 creq->n_channels = i;
1469
1470 /* translate "Scan for SSID" request */
1471 if (wreq) {
1472 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1473 if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1474 err = -EINVAL;
1475 goto out;
1476 }
1477 memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1478 creq->ssids[0].ssid_len = wreq->essid_len;
1479 }
1480 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1481 creq->n_ssids = 0;
1482 }
1483
1484 for (i = 0; i < NUM_NL80211_BANDS; i++)
1485 if (wiphy->bands[i])
1486 creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1487
1488 eth_broadcast_addr(creq->bssid);
1489
1490 rdev->scan_req = creq;
1491 err = rdev_scan(rdev, creq);
1492 if (err) {
1493 rdev->scan_req = NULL;
1494 /* creq will be freed below */
1495 } else {
1496 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1497 /* creq now owned by driver */
1498 creq = NULL;
1499 dev_hold(dev);
1500 }
1501 out:
1502 kfree(creq);
1503 return err;
1504 }
1505 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
1506
1507 static char *ieee80211_scan_add_ies(struct iw_request_info *info,
1508 const struct cfg80211_bss_ies *ies,
1509 char *current_ev, char *end_buf)
1510 {
1511 const u8 *pos, *end, *next;
1512 struct iw_event iwe;
1513
1514 if (!ies)
1515 return current_ev;
1516
1517 /*
1518 * If needed, fragment the IEs buffer (at IE boundaries) into short
1519 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1520 */
1521 pos = ies->data;
1522 end = pos + ies->len;
1523
1524 while (end - pos > IW_GENERIC_IE_MAX) {
1525 next = pos + 2 + pos[1];
1526 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1527 next = next + 2 + next[1];
1528
1529 memset(&iwe, 0, sizeof(iwe));
1530 iwe.cmd = IWEVGENIE;
1531 iwe.u.data.length = next - pos;
1532 current_ev = iwe_stream_add_point_check(info, current_ev,
1533 end_buf, &iwe,
1534 (void *)pos);
1535 if (IS_ERR(current_ev))
1536 return current_ev;
1537 pos = next;
1538 }
1539
1540 if (end > pos) {
1541 memset(&iwe, 0, sizeof(iwe));
1542 iwe.cmd = IWEVGENIE;
1543 iwe.u.data.length = end - pos;
1544 current_ev = iwe_stream_add_point_check(info, current_ev,
1545 end_buf, &iwe,
1546 (void *)pos);
1547 if (IS_ERR(current_ev))
1548 return current_ev;
1549 }
1550
1551 return current_ev;
1552 }
1553
1554 static char *
1555 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1556 struct cfg80211_internal_bss *bss, char *current_ev,
1557 char *end_buf)
1558 {
1559 const struct cfg80211_bss_ies *ies;
1560 struct iw_event iwe;
1561 const u8 *ie;
1562 u8 buf[50];
1563 u8 *cfg, *p, *tmp;
1564 int rem, i, sig;
1565 bool ismesh = false;
1566
1567 memset(&iwe, 0, sizeof(iwe));
1568 iwe.cmd = SIOCGIWAP;
1569 iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1570 memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1571 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1572 IW_EV_ADDR_LEN);
1573 if (IS_ERR(current_ev))
1574 return current_ev;
1575
1576 memset(&iwe, 0, sizeof(iwe));
1577 iwe.cmd = SIOCGIWFREQ;
1578 iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1579 iwe.u.freq.e = 0;
1580 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1581 IW_EV_FREQ_LEN);
1582 if (IS_ERR(current_ev))
1583 return current_ev;
1584
1585 memset(&iwe, 0, sizeof(iwe));
1586 iwe.cmd = SIOCGIWFREQ;
1587 iwe.u.freq.m = bss->pub.channel->center_freq;
1588 iwe.u.freq.e = 6;
1589 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1590 IW_EV_FREQ_LEN);
1591 if (IS_ERR(current_ev))
1592 return current_ev;
1593
1594 if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1595 memset(&iwe, 0, sizeof(iwe));
1596 iwe.cmd = IWEVQUAL;
1597 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1598 IW_QUAL_NOISE_INVALID |
1599 IW_QUAL_QUAL_UPDATED;
1600 switch (wiphy->signal_type) {
1601 case CFG80211_SIGNAL_TYPE_MBM:
1602 sig = bss->pub.signal / 100;
1603 iwe.u.qual.level = sig;
1604 iwe.u.qual.updated |= IW_QUAL_DBM;
1605 if (sig < -110) /* rather bad */
1606 sig = -110;
1607 else if (sig > -40) /* perfect */
1608 sig = -40;
1609 /* will give a range of 0 .. 70 */
1610 iwe.u.qual.qual = sig + 110;
1611 break;
1612 case CFG80211_SIGNAL_TYPE_UNSPEC:
1613 iwe.u.qual.level = bss->pub.signal;
1614 /* will give range 0 .. 100 */
1615 iwe.u.qual.qual = bss->pub.signal;
1616 break;
1617 default:
1618 /* not reached */
1619 break;
1620 }
1621 current_ev = iwe_stream_add_event_check(info, current_ev,
1622 end_buf, &iwe,
1623 IW_EV_QUAL_LEN);
1624 if (IS_ERR(current_ev))
1625 return current_ev;
1626 }
1627
1628 memset(&iwe, 0, sizeof(iwe));
1629 iwe.cmd = SIOCGIWENCODE;
1630 if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1631 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1632 else
1633 iwe.u.data.flags = IW_ENCODE_DISABLED;
1634 iwe.u.data.length = 0;
1635 current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1636 &iwe, "");
1637 if (IS_ERR(current_ev))
1638 return current_ev;
1639
1640 rcu_read_lock();
1641 ies = rcu_dereference(bss->pub.ies);
1642 rem = ies->len;
1643 ie = ies->data;
1644
1645 while (rem >= 2) {
1646 /* invalid data */
1647 if (ie[1] > rem - 2)
1648 break;
1649
1650 switch (ie[0]) {
1651 case WLAN_EID_SSID:
1652 memset(&iwe, 0, sizeof(iwe));
1653 iwe.cmd = SIOCGIWESSID;
1654 iwe.u.data.length = ie[1];
1655 iwe.u.data.flags = 1;
1656 current_ev = iwe_stream_add_point_check(info,
1657 current_ev,
1658 end_buf, &iwe,
1659 (u8 *)ie + 2);
1660 if (IS_ERR(current_ev))
1661 goto unlock;
1662 break;
1663 case WLAN_EID_MESH_ID:
1664 memset(&iwe, 0, sizeof(iwe));
1665 iwe.cmd = SIOCGIWESSID;
1666 iwe.u.data.length = ie[1];
1667 iwe.u.data.flags = 1;
1668 current_ev = iwe_stream_add_point_check(info,
1669 current_ev,
1670 end_buf, &iwe,
1671 (u8 *)ie + 2);
1672 if (IS_ERR(current_ev))
1673 goto unlock;
1674 break;
1675 case WLAN_EID_MESH_CONFIG:
1676 ismesh = true;
1677 if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1678 break;
1679 cfg = (u8 *)ie + 2;
1680 memset(&iwe, 0, sizeof(iwe));
1681 iwe.cmd = IWEVCUSTOM;
1682 sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1683 "0x%02X", cfg[0]);
1684 iwe.u.data.length = strlen(buf);
1685 current_ev = iwe_stream_add_point_check(info,
1686 current_ev,
1687 end_buf,
1688 &iwe, buf);
1689 if (IS_ERR(current_ev))
1690 goto unlock;
1691 sprintf(buf, "Path Selection Metric ID: 0x%02X",
1692 cfg[1]);
1693 iwe.u.data.length = strlen(buf);
1694 current_ev = iwe_stream_add_point_check(info,
1695 current_ev,
1696 end_buf,
1697 &iwe, buf);
1698 if (IS_ERR(current_ev))
1699 goto unlock;
1700 sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1701 cfg[2]);
1702 iwe.u.data.length = strlen(buf);
1703 current_ev = iwe_stream_add_point_check(info,
1704 current_ev,
1705 end_buf,
1706 &iwe, buf);
1707 if (IS_ERR(current_ev))
1708 goto unlock;
1709 sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1710 iwe.u.data.length = strlen(buf);
1711 current_ev = iwe_stream_add_point_check(info,
1712 current_ev,
1713 end_buf,
1714 &iwe, buf);
1715 if (IS_ERR(current_ev))
1716 goto unlock;
1717 sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1718 iwe.u.data.length = strlen(buf);
1719 current_ev = iwe_stream_add_point_check(info,
1720 current_ev,
1721 end_buf,
1722 &iwe, buf);
1723 if (IS_ERR(current_ev))
1724 goto unlock;
1725 sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1726 iwe.u.data.length = strlen(buf);
1727 current_ev = iwe_stream_add_point_check(info,
1728 current_ev,
1729 end_buf,
1730 &iwe, buf);
1731 if (IS_ERR(current_ev))
1732 goto unlock;
1733 sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1734 iwe.u.data.length = strlen(buf);
1735 current_ev = iwe_stream_add_point_check(info,
1736 current_ev,
1737 end_buf,
1738 &iwe, buf);
1739 if (IS_ERR(current_ev))
1740 goto unlock;
1741 break;
1742 case WLAN_EID_SUPP_RATES:
1743 case WLAN_EID_EXT_SUPP_RATES:
1744 /* display all supported rates in readable format */
1745 p = current_ev + iwe_stream_lcp_len(info);
1746
1747 memset(&iwe, 0, sizeof(iwe));
1748 iwe.cmd = SIOCGIWRATE;
1749 /* Those two flags are ignored... */
1750 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1751
1752 for (i = 0; i < ie[1]; i++) {
1753 iwe.u.bitrate.value =
1754 ((ie[i + 2] & 0x7f) * 500000);
1755 tmp = p;
1756 p = iwe_stream_add_value(info, current_ev, p,
1757 end_buf, &iwe,
1758 IW_EV_PARAM_LEN);
1759 if (p == tmp) {
1760 current_ev = ERR_PTR(-E2BIG);
1761 goto unlock;
1762 }
1763 }
1764 current_ev = p;
1765 break;
1766 }
1767 rem -= ie[1] + 2;
1768 ie += ie[1] + 2;
1769 }
1770
1771 if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1772 ismesh) {
1773 memset(&iwe, 0, sizeof(iwe));
1774 iwe.cmd = SIOCGIWMODE;
1775 if (ismesh)
1776 iwe.u.mode = IW_MODE_MESH;
1777 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1778 iwe.u.mode = IW_MODE_MASTER;
1779 else
1780 iwe.u.mode = IW_MODE_ADHOC;
1781 current_ev = iwe_stream_add_event_check(info, current_ev,
1782 end_buf, &iwe,
1783 IW_EV_UINT_LEN);
1784 if (IS_ERR(current_ev))
1785 goto unlock;
1786 }
1787
1788 memset(&iwe, 0, sizeof(iwe));
1789 iwe.cmd = IWEVCUSTOM;
1790 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1791 iwe.u.data.length = strlen(buf);
1792 current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1793 &iwe, buf);
1794 if (IS_ERR(current_ev))
1795 goto unlock;
1796 memset(&iwe, 0, sizeof(iwe));
1797 iwe.cmd = IWEVCUSTOM;
1798 sprintf(buf, " Last beacon: %ums ago",
1799 elapsed_jiffies_msecs(bss->ts));
1800 iwe.u.data.length = strlen(buf);
1801 current_ev = iwe_stream_add_point_check(info, current_ev,
1802 end_buf, &iwe, buf);
1803 if (IS_ERR(current_ev))
1804 goto unlock;
1805
1806 current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
1807
1808 unlock:
1809 rcu_read_unlock();
1810 return current_ev;
1811 }
1812
1813
1814 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1815 struct iw_request_info *info,
1816 char *buf, size_t len)
1817 {
1818 char *current_ev = buf;
1819 char *end_buf = buf + len;
1820 struct cfg80211_internal_bss *bss;
1821 int err = 0;
1822
1823 spin_lock_bh(&rdev->bss_lock);
1824 cfg80211_bss_expire(rdev);
1825
1826 list_for_each_entry(bss, &rdev->bss_list, list) {
1827 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1828 err = -E2BIG;
1829 break;
1830 }
1831 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1832 current_ev, end_buf);
1833 if (IS_ERR(current_ev)) {
1834 err = PTR_ERR(current_ev);
1835 break;
1836 }
1837 }
1838 spin_unlock_bh(&rdev->bss_lock);
1839
1840 if (err)
1841 return err;
1842 return current_ev - buf;
1843 }
1844
1845
1846 int cfg80211_wext_giwscan(struct net_device *dev,
1847 struct iw_request_info *info,
1848 struct iw_point *data, char *extra)
1849 {
1850 struct cfg80211_registered_device *rdev;
1851 int res;
1852
1853 if (!netif_running(dev))
1854 return -ENETDOWN;
1855
1856 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1857
1858 if (IS_ERR(rdev))
1859 return PTR_ERR(rdev);
1860
1861 if (rdev->scan_req || rdev->scan_msg)
1862 return -EAGAIN;
1863
1864 res = ieee80211_scan_results(rdev, info, extra, data->length);
1865 data->length = 0;
1866 if (res >= 0) {
1867 data->length = res;
1868 res = 0;
1869 }
1870
1871 return res;
1872 }
1873 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
1874 #endif