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cfg80211: add and use strongly typed element iteration macros
[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 const struct element *elem;
488
489 /* match_offset can't be smaller than 2, unless match_len is
490 * zero, in which case match_offset must be zero as well.
491 */
492 if (WARN_ON((match_len && match_offset < 2) ||
493 (!match_len && match_offset)))
494 return NULL;
495
496 for_each_element_id(elem, eid, ies, len) {
497 if (elem->datalen >= match_offset - 2 + match_len &&
498 !memcmp(elem->data + match_offset - 2, match, match_len))
499 return (void *)elem;
500 }
501
502 return NULL;
503 }
504 EXPORT_SYMBOL(cfg80211_find_ie_match);
505
506 const u8 *cfg80211_find_vendor_ie(unsigned int oui, int oui_type,
507 const u8 *ies, int len)
508 {
509 const u8 *ie;
510 u8 match[] = { oui >> 16, oui >> 8, oui, oui_type };
511 int match_len = (oui_type < 0) ? 3 : sizeof(match);
512
513 if (WARN_ON(oui_type > 0xff))
514 return NULL;
515
516 ie = cfg80211_find_ie_match(WLAN_EID_VENDOR_SPECIFIC, ies, len,
517 match, match_len, 2);
518
519 if (ie && (ie[1] < 4))
520 return NULL;
521
522 return ie;
523 }
524 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
525
526 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
527 const u8 *ssid, size_t ssid_len)
528 {
529 const struct cfg80211_bss_ies *ies;
530 const u8 *ssidie;
531
532 if (bssid && !ether_addr_equal(a->bssid, bssid))
533 return false;
534
535 if (!ssid)
536 return true;
537
538 ies = rcu_access_pointer(a->ies);
539 if (!ies)
540 return false;
541 ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
542 if (!ssidie)
543 return false;
544 if (ssidie[1] != ssid_len)
545 return false;
546 return memcmp(ssidie + 2, ssid, ssid_len) == 0;
547 }
548
549 /**
550 * enum bss_compare_mode - BSS compare mode
551 * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
552 * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
553 * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
554 */
555 enum bss_compare_mode {
556 BSS_CMP_REGULAR,
557 BSS_CMP_HIDE_ZLEN,
558 BSS_CMP_HIDE_NUL,
559 };
560
561 static int cmp_bss(struct cfg80211_bss *a,
562 struct cfg80211_bss *b,
563 enum bss_compare_mode mode)
564 {
565 const struct cfg80211_bss_ies *a_ies, *b_ies;
566 const u8 *ie1 = NULL;
567 const u8 *ie2 = NULL;
568 int i, r;
569
570 if (a->channel != b->channel)
571 return b->channel->center_freq - a->channel->center_freq;
572
573 a_ies = rcu_access_pointer(a->ies);
574 if (!a_ies)
575 return -1;
576 b_ies = rcu_access_pointer(b->ies);
577 if (!b_ies)
578 return 1;
579
580 if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
581 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
582 a_ies->data, a_ies->len);
583 if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
584 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
585 b_ies->data, b_ies->len);
586 if (ie1 && ie2) {
587 int mesh_id_cmp;
588
589 if (ie1[1] == ie2[1])
590 mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
591 else
592 mesh_id_cmp = ie2[1] - ie1[1];
593
594 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
595 a_ies->data, a_ies->len);
596 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
597 b_ies->data, b_ies->len);
598 if (ie1 && ie2) {
599 if (mesh_id_cmp)
600 return mesh_id_cmp;
601 if (ie1[1] != ie2[1])
602 return ie2[1] - ie1[1];
603 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
604 }
605 }
606
607 r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
608 if (r)
609 return r;
610
611 ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
612 ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
613
614 if (!ie1 && !ie2)
615 return 0;
616
617 /*
618 * Note that with "hide_ssid", the function returns a match if
619 * the already-present BSS ("b") is a hidden SSID beacon for
620 * the new BSS ("a").
621 */
622
623 /* sort missing IE before (left of) present IE */
624 if (!ie1)
625 return -1;
626 if (!ie2)
627 return 1;
628
629 switch (mode) {
630 case BSS_CMP_HIDE_ZLEN:
631 /*
632 * In ZLEN mode we assume the BSS entry we're
633 * looking for has a zero-length SSID. So if
634 * the one we're looking at right now has that,
635 * return 0. Otherwise, return the difference
636 * in length, but since we're looking for the
637 * 0-length it's really equivalent to returning
638 * the length of the one we're looking at.
639 *
640 * No content comparison is needed as we assume
641 * the content length is zero.
642 */
643 return ie2[1];
644 case BSS_CMP_REGULAR:
645 default:
646 /* sort by length first, then by contents */
647 if (ie1[1] != ie2[1])
648 return ie2[1] - ie1[1];
649 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
650 case BSS_CMP_HIDE_NUL:
651 if (ie1[1] != ie2[1])
652 return ie2[1] - ie1[1];
653 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
654 for (i = 0; i < ie2[1]; i++)
655 if (ie2[i + 2])
656 return -1;
657 return 0;
658 }
659 }
660
661 static bool cfg80211_bss_type_match(u16 capability,
662 enum nl80211_band band,
663 enum ieee80211_bss_type bss_type)
664 {
665 bool ret = true;
666 u16 mask, val;
667
668 if (bss_type == IEEE80211_BSS_TYPE_ANY)
669 return ret;
670
671 if (band == NL80211_BAND_60GHZ) {
672 mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
673 switch (bss_type) {
674 case IEEE80211_BSS_TYPE_ESS:
675 val = WLAN_CAPABILITY_DMG_TYPE_AP;
676 break;
677 case IEEE80211_BSS_TYPE_PBSS:
678 val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
679 break;
680 case IEEE80211_BSS_TYPE_IBSS:
681 val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
682 break;
683 default:
684 return false;
685 }
686 } else {
687 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
688 switch (bss_type) {
689 case IEEE80211_BSS_TYPE_ESS:
690 val = WLAN_CAPABILITY_ESS;
691 break;
692 case IEEE80211_BSS_TYPE_IBSS:
693 val = WLAN_CAPABILITY_IBSS;
694 break;
695 case IEEE80211_BSS_TYPE_MBSS:
696 val = 0;
697 break;
698 default:
699 return false;
700 }
701 }
702
703 ret = ((capability & mask) == val);
704 return ret;
705 }
706
707 /* Returned bss is reference counted and must be cleaned up appropriately. */
708 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
709 struct ieee80211_channel *channel,
710 const u8 *bssid,
711 const u8 *ssid, size_t ssid_len,
712 enum ieee80211_bss_type bss_type,
713 enum ieee80211_privacy privacy)
714 {
715 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
716 struct cfg80211_internal_bss *bss, *res = NULL;
717 unsigned long now = jiffies;
718 int bss_privacy;
719
720 trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
721 privacy);
722
723 spin_lock_bh(&rdev->bss_lock);
724
725 list_for_each_entry(bss, &rdev->bss_list, list) {
726 if (!cfg80211_bss_type_match(bss->pub.capability,
727 bss->pub.channel->band, bss_type))
728 continue;
729
730 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
731 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
732 (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
733 continue;
734 if (channel && bss->pub.channel != channel)
735 continue;
736 if (!is_valid_ether_addr(bss->pub.bssid))
737 continue;
738 /* Don't get expired BSS structs */
739 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
740 !atomic_read(&bss->hold))
741 continue;
742 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
743 res = bss;
744 bss_ref_get(rdev, res);
745 break;
746 }
747 }
748
749 spin_unlock_bh(&rdev->bss_lock);
750 if (!res)
751 return NULL;
752 trace_cfg80211_return_bss(&res->pub);
753 return &res->pub;
754 }
755 EXPORT_SYMBOL(cfg80211_get_bss);
756
757 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
758 struct cfg80211_internal_bss *bss)
759 {
760 struct rb_node **p = &rdev->bss_tree.rb_node;
761 struct rb_node *parent = NULL;
762 struct cfg80211_internal_bss *tbss;
763 int cmp;
764
765 while (*p) {
766 parent = *p;
767 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
768
769 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
770
771 if (WARN_ON(!cmp)) {
772 /* will sort of leak this BSS */
773 return;
774 }
775
776 if (cmp < 0)
777 p = &(*p)->rb_left;
778 else
779 p = &(*p)->rb_right;
780 }
781
782 rb_link_node(&bss->rbn, parent, p);
783 rb_insert_color(&bss->rbn, &rdev->bss_tree);
784 }
785
786 static struct cfg80211_internal_bss *
787 rb_find_bss(struct cfg80211_registered_device *rdev,
788 struct cfg80211_internal_bss *res,
789 enum bss_compare_mode mode)
790 {
791 struct rb_node *n = rdev->bss_tree.rb_node;
792 struct cfg80211_internal_bss *bss;
793 int r;
794
795 while (n) {
796 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
797 r = cmp_bss(&res->pub, &bss->pub, mode);
798
799 if (r == 0)
800 return bss;
801 else if (r < 0)
802 n = n->rb_left;
803 else
804 n = n->rb_right;
805 }
806
807 return NULL;
808 }
809
810 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
811 struct cfg80211_internal_bss *new)
812 {
813 const struct cfg80211_bss_ies *ies;
814 struct cfg80211_internal_bss *bss;
815 const u8 *ie;
816 int i, ssidlen;
817 u8 fold = 0;
818 u32 n_entries = 0;
819
820 ies = rcu_access_pointer(new->pub.beacon_ies);
821 if (WARN_ON(!ies))
822 return false;
823
824 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
825 if (!ie) {
826 /* nothing to do */
827 return true;
828 }
829
830 ssidlen = ie[1];
831 for (i = 0; i < ssidlen; i++)
832 fold |= ie[2 + i];
833
834 if (fold) {
835 /* not a hidden SSID */
836 return true;
837 }
838
839 /* This is the bad part ... */
840
841 list_for_each_entry(bss, &rdev->bss_list, list) {
842 /*
843 * we're iterating all the entries anyway, so take the
844 * opportunity to validate the list length accounting
845 */
846 n_entries++;
847
848 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
849 continue;
850 if (bss->pub.channel != new->pub.channel)
851 continue;
852 if (bss->pub.scan_width != new->pub.scan_width)
853 continue;
854 if (rcu_access_pointer(bss->pub.beacon_ies))
855 continue;
856 ies = rcu_access_pointer(bss->pub.ies);
857 if (!ies)
858 continue;
859 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
860 if (!ie)
861 continue;
862 if (ssidlen && ie[1] != ssidlen)
863 continue;
864 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
865 continue;
866 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
867 list_del(&bss->hidden_list);
868 /* combine them */
869 list_add(&bss->hidden_list, &new->hidden_list);
870 bss->pub.hidden_beacon_bss = &new->pub;
871 new->refcount += bss->refcount;
872 rcu_assign_pointer(bss->pub.beacon_ies,
873 new->pub.beacon_ies);
874 }
875
876 WARN_ONCE(n_entries != rdev->bss_entries,
877 "rdev bss entries[%d]/list[len:%d] corruption\n",
878 rdev->bss_entries, n_entries);
879
880 return true;
881 }
882
883 /* Returned bss is reference counted and must be cleaned up appropriately. */
884 static struct cfg80211_internal_bss *
885 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
886 struct cfg80211_internal_bss *tmp,
887 bool signal_valid)
888 {
889 struct cfg80211_internal_bss *found = NULL;
890
891 if (WARN_ON(!tmp->pub.channel))
892 return NULL;
893
894 tmp->ts = jiffies;
895
896 spin_lock_bh(&rdev->bss_lock);
897
898 if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
899 spin_unlock_bh(&rdev->bss_lock);
900 return NULL;
901 }
902
903 found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
904
905 if (found) {
906 /* Update IEs */
907 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
908 const struct cfg80211_bss_ies *old;
909
910 old = rcu_access_pointer(found->pub.proberesp_ies);
911
912 rcu_assign_pointer(found->pub.proberesp_ies,
913 tmp->pub.proberesp_ies);
914 /* Override possible earlier Beacon frame IEs */
915 rcu_assign_pointer(found->pub.ies,
916 tmp->pub.proberesp_ies);
917 if (old)
918 kfree_rcu((struct cfg80211_bss_ies *)old,
919 rcu_head);
920 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
921 const struct cfg80211_bss_ies *old;
922 struct cfg80211_internal_bss *bss;
923
924 if (found->pub.hidden_beacon_bss &&
925 !list_empty(&found->hidden_list)) {
926 const struct cfg80211_bss_ies *f;
927
928 /*
929 * The found BSS struct is one of the probe
930 * response members of a group, but we're
931 * receiving a beacon (beacon_ies in the tmp
932 * bss is used). This can only mean that the
933 * AP changed its beacon from not having an
934 * SSID to showing it, which is confusing so
935 * drop this information.
936 */
937
938 f = rcu_access_pointer(tmp->pub.beacon_ies);
939 kfree_rcu((struct cfg80211_bss_ies *)f,
940 rcu_head);
941 goto drop;
942 }
943
944 old = rcu_access_pointer(found->pub.beacon_ies);
945
946 rcu_assign_pointer(found->pub.beacon_ies,
947 tmp->pub.beacon_ies);
948
949 /* Override IEs if they were from a beacon before */
950 if (old == rcu_access_pointer(found->pub.ies))
951 rcu_assign_pointer(found->pub.ies,
952 tmp->pub.beacon_ies);
953
954 /* Assign beacon IEs to all sub entries */
955 list_for_each_entry(bss, &found->hidden_list,
956 hidden_list) {
957 const struct cfg80211_bss_ies *ies;
958
959 ies = rcu_access_pointer(bss->pub.beacon_ies);
960 WARN_ON(ies != old);
961
962 rcu_assign_pointer(bss->pub.beacon_ies,
963 tmp->pub.beacon_ies);
964 }
965
966 if (old)
967 kfree_rcu((struct cfg80211_bss_ies *)old,
968 rcu_head);
969 }
970
971 found->pub.beacon_interval = tmp->pub.beacon_interval;
972 /*
973 * don't update the signal if beacon was heard on
974 * adjacent channel.
975 */
976 if (signal_valid)
977 found->pub.signal = tmp->pub.signal;
978 found->pub.capability = tmp->pub.capability;
979 found->ts = tmp->ts;
980 found->ts_boottime = tmp->ts_boottime;
981 found->parent_tsf = tmp->parent_tsf;
982 ether_addr_copy(found->parent_bssid, tmp->parent_bssid);
983 } else {
984 struct cfg80211_internal_bss *new;
985 struct cfg80211_internal_bss *hidden;
986 struct cfg80211_bss_ies *ies;
987
988 /*
989 * create a copy -- the "res" variable that is passed in
990 * is allocated on the stack since it's not needed in the
991 * more common case of an update
992 */
993 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
994 GFP_ATOMIC);
995 if (!new) {
996 ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
997 if (ies)
998 kfree_rcu(ies, rcu_head);
999 ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
1000 if (ies)
1001 kfree_rcu(ies, rcu_head);
1002 goto drop;
1003 }
1004 memcpy(new, tmp, sizeof(*new));
1005 new->refcount = 1;
1006 INIT_LIST_HEAD(&new->hidden_list);
1007
1008 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
1009 hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
1010 if (!hidden)
1011 hidden = rb_find_bss(rdev, tmp,
1012 BSS_CMP_HIDE_NUL);
1013 if (hidden) {
1014 new->pub.hidden_beacon_bss = &hidden->pub;
1015 list_add(&new->hidden_list,
1016 &hidden->hidden_list);
1017 hidden->refcount++;
1018 rcu_assign_pointer(new->pub.beacon_ies,
1019 hidden->pub.beacon_ies);
1020 }
1021 } else {
1022 /*
1023 * Ok so we found a beacon, and don't have an entry. If
1024 * it's a beacon with hidden SSID, we might be in for an
1025 * expensive search for any probe responses that should
1026 * be grouped with this beacon for updates ...
1027 */
1028 if (!cfg80211_combine_bsses(rdev, new)) {
1029 kfree(new);
1030 goto drop;
1031 }
1032 }
1033
1034 if (rdev->bss_entries >= bss_entries_limit &&
1035 !cfg80211_bss_expire_oldest(rdev)) {
1036 kfree(new);
1037 goto drop;
1038 }
1039
1040 list_add_tail(&new->list, &rdev->bss_list);
1041 rdev->bss_entries++;
1042 rb_insert_bss(rdev, new);
1043 found = new;
1044 }
1045
1046 rdev->bss_generation++;
1047 bss_ref_get(rdev, found);
1048 spin_unlock_bh(&rdev->bss_lock);
1049
1050 return found;
1051 drop:
1052 spin_unlock_bh(&rdev->bss_lock);
1053 return NULL;
1054 }
1055
1056 /*
1057 * Update RX channel information based on the available frame payload
1058 * information. This is mainly for the 2.4 GHz band where frames can be received
1059 * from neighboring channels and the Beacon frames use the DSSS Parameter Set
1060 * element to indicate the current (transmitting) channel, but this might also
1061 * be needed on other bands if RX frequency does not match with the actual
1062 * operating channel of a BSS.
1063 */
1064 static struct ieee80211_channel *
1065 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
1066 struct ieee80211_channel *channel,
1067 enum nl80211_bss_scan_width scan_width)
1068 {
1069 const u8 *tmp;
1070 u32 freq;
1071 int channel_number = -1;
1072 struct ieee80211_channel *alt_channel;
1073
1074 tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
1075 if (tmp && tmp[1] == 1) {
1076 channel_number = tmp[2];
1077 } else {
1078 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
1079 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
1080 struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
1081
1082 channel_number = htop->primary_chan;
1083 }
1084 }
1085
1086 if (channel_number < 0) {
1087 /* No channel information in frame payload */
1088 return channel;
1089 }
1090
1091 freq = ieee80211_channel_to_frequency(channel_number, channel->band);
1092 alt_channel = ieee80211_get_channel(wiphy, freq);
1093 if (!alt_channel) {
1094 if (channel->band == NL80211_BAND_2GHZ) {
1095 /*
1096 * Better not allow unexpected channels when that could
1097 * be going beyond the 1-11 range (e.g., discovering
1098 * BSS on channel 12 when radio is configured for
1099 * channel 11.
1100 */
1101 return NULL;
1102 }
1103
1104 /* No match for the payload channel number - ignore it */
1105 return channel;
1106 }
1107
1108 if (scan_width == NL80211_BSS_CHAN_WIDTH_10 ||
1109 scan_width == NL80211_BSS_CHAN_WIDTH_5) {
1110 /*
1111 * Ignore channel number in 5 and 10 MHz channels where there
1112 * may not be an n:1 or 1:n mapping between frequencies and
1113 * channel numbers.
1114 */
1115 return channel;
1116 }
1117
1118 /*
1119 * Use the channel determined through the payload channel number
1120 * instead of the RX channel reported by the driver.
1121 */
1122 if (alt_channel->flags & IEEE80211_CHAN_DISABLED)
1123 return NULL;
1124 return alt_channel;
1125 }
1126
1127 /* Returned bss is reference counted and must be cleaned up appropriately. */
1128 struct cfg80211_bss *
1129 cfg80211_inform_bss_data(struct wiphy *wiphy,
1130 struct cfg80211_inform_bss *data,
1131 enum cfg80211_bss_frame_type ftype,
1132 const u8 *bssid, u64 tsf, u16 capability,
1133 u16 beacon_interval, const u8 *ie, size_t ielen,
1134 gfp_t gfp)
1135 {
1136 struct cfg80211_bss_ies *ies;
1137 struct ieee80211_channel *channel;
1138 struct cfg80211_internal_bss tmp = {}, *res;
1139 int bss_type;
1140 bool signal_valid;
1141
1142 if (WARN_ON(!wiphy))
1143 return NULL;
1144
1145 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1146 (data->signal < 0 || data->signal > 100)))
1147 return NULL;
1148
1149 channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan,
1150 data->scan_width);
1151 if (!channel)
1152 return NULL;
1153
1154 memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
1155 tmp.pub.channel = channel;
1156 tmp.pub.scan_width = data->scan_width;
1157 tmp.pub.signal = data->signal;
1158 tmp.pub.beacon_interval = beacon_interval;
1159 tmp.pub.capability = capability;
1160 tmp.ts_boottime = data->boottime_ns;
1161
1162 /*
1163 * If we do not know here whether the IEs are from a Beacon or Probe
1164 * Response frame, we need to pick one of the options and only use it
1165 * with the driver that does not provide the full Beacon/Probe Response
1166 * frame. Use Beacon frame pointer to avoid indicating that this should
1167 * override the IEs pointer should we have received an earlier
1168 * indication of Probe Response data.
1169 */
1170 ies = kzalloc(sizeof(*ies) + ielen, gfp);
1171 if (!ies)
1172 return NULL;
1173 ies->len = ielen;
1174 ies->tsf = tsf;
1175 ies->from_beacon = false;
1176 memcpy(ies->data, ie, ielen);
1177
1178 switch (ftype) {
1179 case CFG80211_BSS_FTYPE_BEACON:
1180 ies->from_beacon = true;
1181 /* fall through to assign */
1182 case CFG80211_BSS_FTYPE_UNKNOWN:
1183 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1184 break;
1185 case CFG80211_BSS_FTYPE_PRESP:
1186 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1187 break;
1188 }
1189 rcu_assign_pointer(tmp.pub.ies, ies);
1190
1191 signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1192 wiphy->max_adj_channel_rssi_comp;
1193 res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1194 if (!res)
1195 return NULL;
1196
1197 if (channel->band == NL80211_BAND_60GHZ) {
1198 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1199 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1200 bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1201 regulatory_hint_found_beacon(wiphy, channel, gfp);
1202 } else {
1203 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1204 regulatory_hint_found_beacon(wiphy, channel, gfp);
1205 }
1206
1207 trace_cfg80211_return_bss(&res->pub);
1208 /* cfg80211_bss_update gives us a referenced result */
1209 return &res->pub;
1210 }
1211 EXPORT_SYMBOL(cfg80211_inform_bss_data);
1212
1213 /* cfg80211_inform_bss_width_frame helper */
1214 struct cfg80211_bss *
1215 cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
1216 struct cfg80211_inform_bss *data,
1217 struct ieee80211_mgmt *mgmt, size_t len,
1218 gfp_t gfp)
1219
1220 {
1221 struct cfg80211_internal_bss tmp = {}, *res;
1222 struct cfg80211_bss_ies *ies;
1223 struct ieee80211_channel *channel;
1224 bool signal_valid;
1225 size_t ielen = len - offsetof(struct ieee80211_mgmt,
1226 u.probe_resp.variable);
1227 int bss_type;
1228
1229 BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
1230 offsetof(struct ieee80211_mgmt, u.beacon.variable));
1231
1232 trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);
1233
1234 if (WARN_ON(!mgmt))
1235 return NULL;
1236
1237 if (WARN_ON(!wiphy))
1238 return NULL;
1239
1240 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1241 (data->signal < 0 || data->signal > 100)))
1242 return NULL;
1243
1244 if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
1245 return NULL;
1246
1247 channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
1248 ielen, data->chan, data->scan_width);
1249 if (!channel)
1250 return NULL;
1251
1252 ies = kzalloc(sizeof(*ies) + ielen, gfp);
1253 if (!ies)
1254 return NULL;
1255 ies->len = ielen;
1256 ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1257 ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1258 memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1259
1260 if (ieee80211_is_probe_resp(mgmt->frame_control))
1261 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1262 else
1263 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1264 rcu_assign_pointer(tmp.pub.ies, ies);
1265
1266 memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1267 tmp.pub.channel = channel;
1268 tmp.pub.scan_width = data->scan_width;
1269 tmp.pub.signal = data->signal;
1270 tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1271 tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1272 tmp.ts_boottime = data->boottime_ns;
1273 tmp.parent_tsf = data->parent_tsf;
1274 ether_addr_copy(tmp.parent_bssid, data->parent_bssid);
1275
1276 signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1277 wiphy->max_adj_channel_rssi_comp;
1278 res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1279 if (!res)
1280 return NULL;
1281
1282 if (channel->band == NL80211_BAND_60GHZ) {
1283 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1284 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1285 bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1286 regulatory_hint_found_beacon(wiphy, channel, gfp);
1287 } else {
1288 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1289 regulatory_hint_found_beacon(wiphy, channel, gfp);
1290 }
1291
1292 trace_cfg80211_return_bss(&res->pub);
1293 /* cfg80211_bss_update gives us a referenced result */
1294 return &res->pub;
1295 }
1296 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
1297
1298 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1299 {
1300 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1301 struct cfg80211_internal_bss *bss;
1302
1303 if (!pub)
1304 return;
1305
1306 bss = container_of(pub, struct cfg80211_internal_bss, pub);
1307
1308 spin_lock_bh(&rdev->bss_lock);
1309 bss_ref_get(rdev, bss);
1310 spin_unlock_bh(&rdev->bss_lock);
1311 }
1312 EXPORT_SYMBOL(cfg80211_ref_bss);
1313
1314 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1315 {
1316 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1317 struct cfg80211_internal_bss *bss;
1318
1319 if (!pub)
1320 return;
1321
1322 bss = container_of(pub, struct cfg80211_internal_bss, pub);
1323
1324 spin_lock_bh(&rdev->bss_lock);
1325 bss_ref_put(rdev, bss);
1326 spin_unlock_bh(&rdev->bss_lock);
1327 }
1328 EXPORT_SYMBOL(cfg80211_put_bss);
1329
1330 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1331 {
1332 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1333 struct cfg80211_internal_bss *bss;
1334
1335 if (WARN_ON(!pub))
1336 return;
1337
1338 bss = container_of(pub, struct cfg80211_internal_bss, pub);
1339
1340 spin_lock_bh(&rdev->bss_lock);
1341 if (!list_empty(&bss->list)) {
1342 if (__cfg80211_unlink_bss(rdev, bss))
1343 rdev->bss_generation++;
1344 }
1345 spin_unlock_bh(&rdev->bss_lock);
1346 }
1347 EXPORT_SYMBOL(cfg80211_unlink_bss);
1348
1349 #ifdef CONFIG_CFG80211_WEXT
1350 static struct cfg80211_registered_device *
1351 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1352 {
1353 struct cfg80211_registered_device *rdev;
1354 struct net_device *dev;
1355
1356 ASSERT_RTNL();
1357
1358 dev = dev_get_by_index(net, ifindex);
1359 if (!dev)
1360 return ERR_PTR(-ENODEV);
1361 if (dev->ieee80211_ptr)
1362 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1363 else
1364 rdev = ERR_PTR(-ENODEV);
1365 dev_put(dev);
1366 return rdev;
1367 }
1368
1369 int cfg80211_wext_siwscan(struct net_device *dev,
1370 struct iw_request_info *info,
1371 union iwreq_data *wrqu, char *extra)
1372 {
1373 struct cfg80211_registered_device *rdev;
1374 struct wiphy *wiphy;
1375 struct iw_scan_req *wreq = NULL;
1376 struct cfg80211_scan_request *creq = NULL;
1377 int i, err, n_channels = 0;
1378 enum nl80211_band band;
1379
1380 if (!netif_running(dev))
1381 return -ENETDOWN;
1382
1383 if (wrqu->data.length == sizeof(struct iw_scan_req))
1384 wreq = (struct iw_scan_req *)extra;
1385
1386 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1387
1388 if (IS_ERR(rdev))
1389 return PTR_ERR(rdev);
1390
1391 if (rdev->scan_req || rdev->scan_msg) {
1392 err = -EBUSY;
1393 goto out;
1394 }
1395
1396 wiphy = &rdev->wiphy;
1397
1398 /* Determine number of channels, needed to allocate creq */
1399 if (wreq && wreq->num_channels)
1400 n_channels = wreq->num_channels;
1401 else
1402 n_channels = ieee80211_get_num_supported_channels(wiphy);
1403
1404 creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1405 n_channels * sizeof(void *),
1406 GFP_ATOMIC);
1407 if (!creq) {
1408 err = -ENOMEM;
1409 goto out;
1410 }
1411
1412 creq->wiphy = wiphy;
1413 creq->wdev = dev->ieee80211_ptr;
1414 /* SSIDs come after channels */
1415 creq->ssids = (void *)&creq->channels[n_channels];
1416 creq->n_channels = n_channels;
1417 creq->n_ssids = 1;
1418 creq->scan_start = jiffies;
1419
1420 /* translate "Scan on frequencies" request */
1421 i = 0;
1422 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1423 int j;
1424
1425 if (!wiphy->bands[band])
1426 continue;
1427
1428 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1429 /* ignore disabled channels */
1430 if (wiphy->bands[band]->channels[j].flags &
1431 IEEE80211_CHAN_DISABLED)
1432 continue;
1433
1434 /* If we have a wireless request structure and the
1435 * wireless request specifies frequencies, then search
1436 * for the matching hardware channel.
1437 */
1438 if (wreq && wreq->num_channels) {
1439 int k;
1440 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1441 for (k = 0; k < wreq->num_channels; k++) {
1442 struct iw_freq *freq =
1443 &wreq->channel_list[k];
1444 int wext_freq =
1445 cfg80211_wext_freq(freq);
1446
1447 if (wext_freq == wiphy_freq)
1448 goto wext_freq_found;
1449 }
1450 goto wext_freq_not_found;
1451 }
1452
1453 wext_freq_found:
1454 creq->channels[i] = &wiphy->bands[band]->channels[j];
1455 i++;
1456 wext_freq_not_found: ;
1457 }
1458 }
1459 /* No channels found? */
1460 if (!i) {
1461 err = -EINVAL;
1462 goto out;
1463 }
1464
1465 /* Set real number of channels specified in creq->channels[] */
1466 creq->n_channels = i;
1467
1468 /* translate "Scan for SSID" request */
1469 if (wreq) {
1470 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1471 if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1472 err = -EINVAL;
1473 goto out;
1474 }
1475 memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1476 creq->ssids[0].ssid_len = wreq->essid_len;
1477 }
1478 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1479 creq->n_ssids = 0;
1480 }
1481
1482 for (i = 0; i < NUM_NL80211_BANDS; i++)
1483 if (wiphy->bands[i])
1484 creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1485
1486 eth_broadcast_addr(creq->bssid);
1487
1488 rdev->scan_req = creq;
1489 err = rdev_scan(rdev, creq);
1490 if (err) {
1491 rdev->scan_req = NULL;
1492 /* creq will be freed below */
1493 } else {
1494 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1495 /* creq now owned by driver */
1496 creq = NULL;
1497 dev_hold(dev);
1498 }
1499 out:
1500 kfree(creq);
1501 return err;
1502 }
1503 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
1504
1505 static char *ieee80211_scan_add_ies(struct iw_request_info *info,
1506 const struct cfg80211_bss_ies *ies,
1507 char *current_ev, char *end_buf)
1508 {
1509 const u8 *pos, *end, *next;
1510 struct iw_event iwe;
1511
1512 if (!ies)
1513 return current_ev;
1514
1515 /*
1516 * If needed, fragment the IEs buffer (at IE boundaries) into short
1517 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1518 */
1519 pos = ies->data;
1520 end = pos + ies->len;
1521
1522 while (end - pos > IW_GENERIC_IE_MAX) {
1523 next = pos + 2 + pos[1];
1524 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1525 next = next + 2 + next[1];
1526
1527 memset(&iwe, 0, sizeof(iwe));
1528 iwe.cmd = IWEVGENIE;
1529 iwe.u.data.length = next - pos;
1530 current_ev = iwe_stream_add_point_check(info, current_ev,
1531 end_buf, &iwe,
1532 (void *)pos);
1533 if (IS_ERR(current_ev))
1534 return current_ev;
1535 pos = next;
1536 }
1537
1538 if (end > pos) {
1539 memset(&iwe, 0, sizeof(iwe));
1540 iwe.cmd = IWEVGENIE;
1541 iwe.u.data.length = end - pos;
1542 current_ev = iwe_stream_add_point_check(info, current_ev,
1543 end_buf, &iwe,
1544 (void *)pos);
1545 if (IS_ERR(current_ev))
1546 return current_ev;
1547 }
1548
1549 return current_ev;
1550 }
1551
1552 static char *
1553 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1554 struct cfg80211_internal_bss *bss, char *current_ev,
1555 char *end_buf)
1556 {
1557 const struct cfg80211_bss_ies *ies;
1558 struct iw_event iwe;
1559 const u8 *ie;
1560 u8 buf[50];
1561 u8 *cfg, *p, *tmp;
1562 int rem, i, sig;
1563 bool ismesh = false;
1564
1565 memset(&iwe, 0, sizeof(iwe));
1566 iwe.cmd = SIOCGIWAP;
1567 iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1568 memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1569 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1570 IW_EV_ADDR_LEN);
1571 if (IS_ERR(current_ev))
1572 return current_ev;
1573
1574 memset(&iwe, 0, sizeof(iwe));
1575 iwe.cmd = SIOCGIWFREQ;
1576 iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1577 iwe.u.freq.e = 0;
1578 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1579 IW_EV_FREQ_LEN);
1580 if (IS_ERR(current_ev))
1581 return current_ev;
1582
1583 memset(&iwe, 0, sizeof(iwe));
1584 iwe.cmd = SIOCGIWFREQ;
1585 iwe.u.freq.m = bss->pub.channel->center_freq;
1586 iwe.u.freq.e = 6;
1587 current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1588 IW_EV_FREQ_LEN);
1589 if (IS_ERR(current_ev))
1590 return current_ev;
1591
1592 if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1593 memset(&iwe, 0, sizeof(iwe));
1594 iwe.cmd = IWEVQUAL;
1595 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1596 IW_QUAL_NOISE_INVALID |
1597 IW_QUAL_QUAL_UPDATED;
1598 switch (wiphy->signal_type) {
1599 case CFG80211_SIGNAL_TYPE_MBM:
1600 sig = bss->pub.signal / 100;
1601 iwe.u.qual.level = sig;
1602 iwe.u.qual.updated |= IW_QUAL_DBM;
1603 if (sig < -110) /* rather bad */
1604 sig = -110;
1605 else if (sig > -40) /* perfect */
1606 sig = -40;
1607 /* will give a range of 0 .. 70 */
1608 iwe.u.qual.qual = sig + 110;
1609 break;
1610 case CFG80211_SIGNAL_TYPE_UNSPEC:
1611 iwe.u.qual.level = bss->pub.signal;
1612 /* will give range 0 .. 100 */
1613 iwe.u.qual.qual = bss->pub.signal;
1614 break;
1615 default:
1616 /* not reached */
1617 break;
1618 }
1619 current_ev = iwe_stream_add_event_check(info, current_ev,
1620 end_buf, &iwe,
1621 IW_EV_QUAL_LEN);
1622 if (IS_ERR(current_ev))
1623 return current_ev;
1624 }
1625
1626 memset(&iwe, 0, sizeof(iwe));
1627 iwe.cmd = SIOCGIWENCODE;
1628 if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1629 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1630 else
1631 iwe.u.data.flags = IW_ENCODE_DISABLED;
1632 iwe.u.data.length = 0;
1633 current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1634 &iwe, "");
1635 if (IS_ERR(current_ev))
1636 return current_ev;
1637
1638 rcu_read_lock();
1639 ies = rcu_dereference(bss->pub.ies);
1640 rem = ies->len;
1641 ie = ies->data;
1642
1643 while (rem >= 2) {
1644 /* invalid data */
1645 if (ie[1] > rem - 2)
1646 break;
1647
1648 switch (ie[0]) {
1649 case WLAN_EID_SSID:
1650 memset(&iwe, 0, sizeof(iwe));
1651 iwe.cmd = SIOCGIWESSID;
1652 iwe.u.data.length = ie[1];
1653 iwe.u.data.flags = 1;
1654 current_ev = iwe_stream_add_point_check(info,
1655 current_ev,
1656 end_buf, &iwe,
1657 (u8 *)ie + 2);
1658 if (IS_ERR(current_ev))
1659 goto unlock;
1660 break;
1661 case WLAN_EID_MESH_ID:
1662 memset(&iwe, 0, sizeof(iwe));
1663 iwe.cmd = SIOCGIWESSID;
1664 iwe.u.data.length = ie[1];
1665 iwe.u.data.flags = 1;
1666 current_ev = iwe_stream_add_point_check(info,
1667 current_ev,
1668 end_buf, &iwe,
1669 (u8 *)ie + 2);
1670 if (IS_ERR(current_ev))
1671 goto unlock;
1672 break;
1673 case WLAN_EID_MESH_CONFIG:
1674 ismesh = true;
1675 if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1676 break;
1677 cfg = (u8 *)ie + 2;
1678 memset(&iwe, 0, sizeof(iwe));
1679 iwe.cmd = IWEVCUSTOM;
1680 sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1681 "0x%02X", cfg[0]);
1682 iwe.u.data.length = strlen(buf);
1683 current_ev = iwe_stream_add_point_check(info,
1684 current_ev,
1685 end_buf,
1686 &iwe, buf);
1687 if (IS_ERR(current_ev))
1688 goto unlock;
1689 sprintf(buf, "Path Selection Metric ID: 0x%02X",
1690 cfg[1]);
1691 iwe.u.data.length = strlen(buf);
1692 current_ev = iwe_stream_add_point_check(info,
1693 current_ev,
1694 end_buf,
1695 &iwe, buf);
1696 if (IS_ERR(current_ev))
1697 goto unlock;
1698 sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1699 cfg[2]);
1700 iwe.u.data.length = strlen(buf);
1701 current_ev = iwe_stream_add_point_check(info,
1702 current_ev,
1703 end_buf,
1704 &iwe, buf);
1705 if (IS_ERR(current_ev))
1706 goto unlock;
1707 sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1708 iwe.u.data.length = strlen(buf);
1709 current_ev = iwe_stream_add_point_check(info,
1710 current_ev,
1711 end_buf,
1712 &iwe, buf);
1713 if (IS_ERR(current_ev))
1714 goto unlock;
1715 sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1716 iwe.u.data.length = strlen(buf);
1717 current_ev = iwe_stream_add_point_check(info,
1718 current_ev,
1719 end_buf,
1720 &iwe, buf);
1721 if (IS_ERR(current_ev))
1722 goto unlock;
1723 sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1724 iwe.u.data.length = strlen(buf);
1725 current_ev = iwe_stream_add_point_check(info,
1726 current_ev,
1727 end_buf,
1728 &iwe, buf);
1729 if (IS_ERR(current_ev))
1730 goto unlock;
1731 sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1732 iwe.u.data.length = strlen(buf);
1733 current_ev = iwe_stream_add_point_check(info,
1734 current_ev,
1735 end_buf,
1736 &iwe, buf);
1737 if (IS_ERR(current_ev))
1738 goto unlock;
1739 break;
1740 case WLAN_EID_SUPP_RATES:
1741 case WLAN_EID_EXT_SUPP_RATES:
1742 /* display all supported rates in readable format */
1743 p = current_ev + iwe_stream_lcp_len(info);
1744
1745 memset(&iwe, 0, sizeof(iwe));
1746 iwe.cmd = SIOCGIWRATE;
1747 /* Those two flags are ignored... */
1748 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1749
1750 for (i = 0; i < ie[1]; i++) {
1751 iwe.u.bitrate.value =
1752 ((ie[i + 2] & 0x7f) * 500000);
1753 tmp = p;
1754 p = iwe_stream_add_value(info, current_ev, p,
1755 end_buf, &iwe,
1756 IW_EV_PARAM_LEN);
1757 if (p == tmp) {
1758 current_ev = ERR_PTR(-E2BIG);
1759 goto unlock;
1760 }
1761 }
1762 current_ev = p;
1763 break;
1764 }
1765 rem -= ie[1] + 2;
1766 ie += ie[1] + 2;
1767 }
1768
1769 if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1770 ismesh) {
1771 memset(&iwe, 0, sizeof(iwe));
1772 iwe.cmd = SIOCGIWMODE;
1773 if (ismesh)
1774 iwe.u.mode = IW_MODE_MESH;
1775 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1776 iwe.u.mode = IW_MODE_MASTER;
1777 else
1778 iwe.u.mode = IW_MODE_ADHOC;
1779 current_ev = iwe_stream_add_event_check(info, current_ev,
1780 end_buf, &iwe,
1781 IW_EV_UINT_LEN);
1782 if (IS_ERR(current_ev))
1783 goto unlock;
1784 }
1785
1786 memset(&iwe, 0, sizeof(iwe));
1787 iwe.cmd = IWEVCUSTOM;
1788 sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1789 iwe.u.data.length = strlen(buf);
1790 current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1791 &iwe, buf);
1792 if (IS_ERR(current_ev))
1793 goto unlock;
1794 memset(&iwe, 0, sizeof(iwe));
1795 iwe.cmd = IWEVCUSTOM;
1796 sprintf(buf, " Last beacon: %ums ago",
1797 elapsed_jiffies_msecs(bss->ts));
1798 iwe.u.data.length = strlen(buf);
1799 current_ev = iwe_stream_add_point_check(info, current_ev,
1800 end_buf, &iwe, buf);
1801 if (IS_ERR(current_ev))
1802 goto unlock;
1803
1804 current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
1805
1806 unlock:
1807 rcu_read_unlock();
1808 return current_ev;
1809 }
1810
1811
1812 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1813 struct iw_request_info *info,
1814 char *buf, size_t len)
1815 {
1816 char *current_ev = buf;
1817 char *end_buf = buf + len;
1818 struct cfg80211_internal_bss *bss;
1819 int err = 0;
1820
1821 spin_lock_bh(&rdev->bss_lock);
1822 cfg80211_bss_expire(rdev);
1823
1824 list_for_each_entry(bss, &rdev->bss_list, list) {
1825 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1826 err = -E2BIG;
1827 break;
1828 }
1829 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1830 current_ev, end_buf);
1831 if (IS_ERR(current_ev)) {
1832 err = PTR_ERR(current_ev);
1833 break;
1834 }
1835 }
1836 spin_unlock_bh(&rdev->bss_lock);
1837
1838 if (err)
1839 return err;
1840 return current_ev - buf;
1841 }
1842
1843
1844 int cfg80211_wext_giwscan(struct net_device *dev,
1845 struct iw_request_info *info,
1846 struct iw_point *data, char *extra)
1847 {
1848 struct cfg80211_registered_device *rdev;
1849 int res;
1850
1851 if (!netif_running(dev))
1852 return -ENETDOWN;
1853
1854 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1855
1856 if (IS_ERR(rdev))
1857 return PTR_ERR(rdev);
1858
1859 if (rdev->scan_req || rdev->scan_msg)
1860 return -EAGAIN;
1861
1862 res = ieee80211_scan_results(rdev, info, extra, data->length);
1863 data->length = 0;
1864 if (res >= 0) {
1865 data->length = res;
1866 res = 0;
1867 }
1868
1869 return res;
1870 }
1871 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
1872 #endif