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TOMOYO Linux Cross Reference
Linux/net/wireless/scan.c

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  1 /*
  2  * cfg80211 scan result handling
  3  *
  4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
  5  * Copyright 2013-2014  Intel Mobile Communications GmbH
  6  */
  7 #include <linux/kernel.h>
  8 #include <linux/slab.h>
  9 #include <linux/module.h>
 10 #include <linux/netdevice.h>
 11 #include <linux/wireless.h>
 12 #include <linux/nl80211.h>
 13 #include <linux/etherdevice.h>
 14 #include <net/arp.h>
 15 #include <net/cfg80211.h>
 16 #include <net/cfg80211-wext.h>
 17 #include <net/iw_handler.h>
 18 #include "core.h"
 19 #include "nl80211.h"
 20 #include "wext-compat.h"
 21 #include "rdev-ops.h"
 22 
 23 /**
 24  * DOC: BSS tree/list structure
 25  *
 26  * At the top level, the BSS list is kept in both a list in each
 27  * registered device (@bss_list) as well as an RB-tree for faster
 28  * lookup. In the RB-tree, entries can be looked up using their
 29  * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
 30  * for other BSSes.
 31  *
 32  * Due to the possibility of hidden SSIDs, there's a second level
 33  * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
 34  * The hidden_list connects all BSSes belonging to a single AP
 35  * that has a hidden SSID, and connects beacon and probe response
 36  * entries. For a probe response entry for a hidden SSID, the
 37  * hidden_beacon_bss pointer points to the BSS struct holding the
 38  * beacon's information.
 39  *
 40  * Reference counting is done for all these references except for
 41  * the hidden_list, so that a beacon BSS struct that is otherwise
 42  * not referenced has one reference for being on the bss_list and
 43  * one for each probe response entry that points to it using the
 44  * hidden_beacon_bss pointer. When a BSS struct that has such a
 45  * pointer is get/put, the refcount update is also propagated to
 46  * the referenced struct, this ensure that it cannot get removed
 47  * while somebody is using the probe response version.
 48  *
 49  * Note that the hidden_beacon_bss pointer never changes, due to
 50  * the reference counting. Therefore, no locking is needed for
 51  * it.
 52  *
 53  * Also note that the hidden_beacon_bss pointer is only relevant
 54  * if the driver uses something other than the IEs, e.g. private
 55  * data stored stored in the BSS struct, since the beacon IEs are
 56  * also linked into the probe response struct.
 57  */
 58 
 59 #define IEEE80211_SCAN_RESULT_EXPIRE    (30 * HZ)
 60 
 61 static void bss_free(struct cfg80211_internal_bss *bss)
 62 {
 63         struct cfg80211_bss_ies *ies;
 64 
 65         if (WARN_ON(atomic_read(&bss->hold)))
 66                 return;
 67 
 68         ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
 69         if (ies && !bss->pub.hidden_beacon_bss)
 70                 kfree_rcu(ies, rcu_head);
 71         ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
 72         if (ies)
 73                 kfree_rcu(ies, rcu_head);
 74 
 75         /*
 76          * This happens when the module is removed, it doesn't
 77          * really matter any more save for completeness
 78          */
 79         if (!list_empty(&bss->hidden_list))
 80                 list_del(&bss->hidden_list);
 81 
 82         kfree(bss);
 83 }
 84 
 85 static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
 86                                struct cfg80211_internal_bss *bss)
 87 {
 88         lockdep_assert_held(&rdev->bss_lock);
 89 
 90         bss->refcount++;
 91         if (bss->pub.hidden_beacon_bss) {
 92                 bss = container_of(bss->pub.hidden_beacon_bss,
 93                                    struct cfg80211_internal_bss,
 94                                    pub);
 95                 bss->refcount++;
 96         }
 97 }
 98 
 99 static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
100                                struct cfg80211_internal_bss *bss)
101 {
102         lockdep_assert_held(&rdev->bss_lock);
103 
104         if (bss->pub.hidden_beacon_bss) {
105                 struct cfg80211_internal_bss *hbss;
106                 hbss = container_of(bss->pub.hidden_beacon_bss,
107                                     struct cfg80211_internal_bss,
108                                     pub);
109                 hbss->refcount--;
110                 if (hbss->refcount == 0)
111                         bss_free(hbss);
112         }
113         bss->refcount--;
114         if (bss->refcount == 0)
115                 bss_free(bss);
116 }
117 
118 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
119                                   struct cfg80211_internal_bss *bss)
120 {
121         lockdep_assert_held(&rdev->bss_lock);
122 
123         if (!list_empty(&bss->hidden_list)) {
124                 /*
125                  * don't remove the beacon entry if it has
126                  * probe responses associated with it
127                  */
128                 if (!bss->pub.hidden_beacon_bss)
129                         return false;
130                 /*
131                  * if it's a probe response entry break its
132                  * link to the other entries in the group
133                  */
134                 list_del_init(&bss->hidden_list);
135         }
136 
137         list_del_init(&bss->list);
138         rb_erase(&bss->rbn, &rdev->bss_tree);
139         bss_ref_put(rdev, bss);
140         return true;
141 }
142 
143 static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
144                                   unsigned long expire_time)
145 {
146         struct cfg80211_internal_bss *bss, *tmp;
147         bool expired = false;
148 
149         lockdep_assert_held(&rdev->bss_lock);
150 
151         list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
152                 if (atomic_read(&bss->hold))
153                         continue;
154                 if (!time_after(expire_time, bss->ts))
155                         continue;
156 
157                 if (__cfg80211_unlink_bss(rdev, bss))
158                         expired = true;
159         }
160 
161         if (expired)
162                 rdev->bss_generation++;
163 }
164 
165 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
166                            bool send_message)
167 {
168         struct cfg80211_scan_request *request;
169         struct wireless_dev *wdev;
170         struct sk_buff *msg;
171 #ifdef CONFIG_CFG80211_WEXT
172         union iwreq_data wrqu;
173 #endif
174 
175         ASSERT_RTNL();
176 
177         if (rdev->scan_msg) {
178                 nl80211_send_scan_result(rdev, rdev->scan_msg);
179                 rdev->scan_msg = NULL;
180                 return;
181         }
182 
183         request = rdev->scan_req;
184         if (!request)
185                 return;
186 
187         wdev = request->wdev;
188 
189         /*
190          * This must be before sending the other events!
191          * Otherwise, wpa_supplicant gets completely confused with
192          * wext events.
193          */
194         if (wdev->netdev)
195                 cfg80211_sme_scan_done(wdev->netdev);
196 
197         if (!request->aborted &&
198             request->flags & NL80211_SCAN_FLAG_FLUSH) {
199                 /* flush entries from previous scans */
200                 spin_lock_bh(&rdev->bss_lock);
201                 __cfg80211_bss_expire(rdev, request->scan_start);
202                 spin_unlock_bh(&rdev->bss_lock);
203         }
204 
205         msg = nl80211_build_scan_msg(rdev, wdev, request->aborted);
206 
207 #ifdef CONFIG_CFG80211_WEXT
208         if (wdev->netdev && !request->aborted) {
209                 memset(&wrqu, 0, sizeof(wrqu));
210 
211                 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
212         }
213 #endif
214 
215         if (wdev->netdev)
216                 dev_put(wdev->netdev);
217 
218         rdev->scan_req = NULL;
219         kfree(request);
220 
221         if (!send_message)
222                 rdev->scan_msg = msg;
223         else
224                 nl80211_send_scan_result(rdev, msg);
225 }
226 
227 void __cfg80211_scan_done(struct work_struct *wk)
228 {
229         struct cfg80211_registered_device *rdev;
230 
231         rdev = container_of(wk, struct cfg80211_registered_device,
232                             scan_done_wk);
233 
234         rtnl_lock();
235         ___cfg80211_scan_done(rdev, true);
236         rtnl_unlock();
237 }
238 
239 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
240 {
241         trace_cfg80211_scan_done(request, aborted);
242         WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req);
243 
244         request->aborted = aborted;
245         request->notified = true;
246         queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
247 }
248 EXPORT_SYMBOL(cfg80211_scan_done);
249 
250 void __cfg80211_sched_scan_results(struct work_struct *wk)
251 {
252         struct cfg80211_registered_device *rdev;
253         struct cfg80211_sched_scan_request *request;
254 
255         rdev = container_of(wk, struct cfg80211_registered_device,
256                             sched_scan_results_wk);
257 
258         rtnl_lock();
259 
260         request = rtnl_dereference(rdev->sched_scan_req);
261 
262         /* we don't have sched_scan_req anymore if the scan is stopping */
263         if (request) {
264                 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
265                         /* flush entries from previous scans */
266                         spin_lock_bh(&rdev->bss_lock);
267                         __cfg80211_bss_expire(rdev, request->scan_start);
268                         spin_unlock_bh(&rdev->bss_lock);
269                         request->scan_start = jiffies;
270                 }
271                 nl80211_send_sched_scan_results(rdev, request->dev);
272         }
273 
274         rtnl_unlock();
275 }
276 
277 void cfg80211_sched_scan_results(struct wiphy *wiphy)
278 {
279         trace_cfg80211_sched_scan_results(wiphy);
280         /* ignore if we're not scanning */
281 
282         if (rcu_access_pointer(wiphy_to_rdev(wiphy)->sched_scan_req))
283                 queue_work(cfg80211_wq,
284                            &wiphy_to_rdev(wiphy)->sched_scan_results_wk);
285 }
286 EXPORT_SYMBOL(cfg80211_sched_scan_results);
287 
288 void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy)
289 {
290         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
291 
292         ASSERT_RTNL();
293 
294         trace_cfg80211_sched_scan_stopped(wiphy);
295 
296         __cfg80211_stop_sched_scan(rdev, true);
297 }
298 EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
299 
300 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
301 {
302         rtnl_lock();
303         cfg80211_sched_scan_stopped_rtnl(wiphy);
304         rtnl_unlock();
305 }
306 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
307 
308 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
309                                bool driver_initiated)
310 {
311         struct cfg80211_sched_scan_request *sched_scan_req;
312         struct net_device *dev;
313 
314         ASSERT_RTNL();
315 
316         if (!rdev->sched_scan_req)
317                 return -ENOENT;
318 
319         sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
320         dev = sched_scan_req->dev;
321 
322         if (!driver_initiated) {
323                 int err = rdev_sched_scan_stop(rdev, dev);
324                 if (err)
325                         return err;
326         }
327 
328         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
329 
330         RCU_INIT_POINTER(rdev->sched_scan_req, NULL);
331         kfree_rcu(sched_scan_req, rcu_head);
332 
333         return 0;
334 }
335 
336 void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
337                       unsigned long age_secs)
338 {
339         struct cfg80211_internal_bss *bss;
340         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
341 
342         spin_lock_bh(&rdev->bss_lock);
343         list_for_each_entry(bss, &rdev->bss_list, list)
344                 bss->ts -= age_jiffies;
345         spin_unlock_bh(&rdev->bss_lock);
346 }
347 
348 void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
349 {
350         __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
351 }
352 
353 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
354 {
355         while (len > 2 && ies[0] != eid) {
356                 len -= ies[1] + 2;
357                 ies += ies[1] + 2;
358         }
359         if (len < 2)
360                 return NULL;
361         if (len < 2 + ies[1])
362                 return NULL;
363         return ies;
364 }
365 EXPORT_SYMBOL(cfg80211_find_ie);
366 
367 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
368                                   const u8 *ies, int len)
369 {
370         struct ieee80211_vendor_ie *ie;
371         const u8 *pos = ies, *end = ies + len;
372         int ie_oui;
373 
374         while (pos < end) {
375                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
376                                        end - pos);
377                 if (!pos)
378                         return NULL;
379 
380                 ie = (struct ieee80211_vendor_ie *)pos;
381 
382                 /* make sure we can access ie->len */
383                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
384 
385                 if (ie->len < sizeof(*ie))
386                         goto cont;
387 
388                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
389                 if (ie_oui == oui && ie->oui_type == oui_type)
390                         return pos;
391 cont:
392                 pos += 2 + ie->len;
393         }
394         return NULL;
395 }
396 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
397 
398 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
399                    const u8 *ssid, size_t ssid_len)
400 {
401         const struct cfg80211_bss_ies *ies;
402         const u8 *ssidie;
403 
404         if (bssid && !ether_addr_equal(a->bssid, bssid))
405                 return false;
406 
407         if (!ssid)
408                 return true;
409 
410         ies = rcu_access_pointer(a->ies);
411         if (!ies)
412                 return false;
413         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
414         if (!ssidie)
415                 return false;
416         if (ssidie[1] != ssid_len)
417                 return false;
418         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
419 }
420 
421 /**
422  * enum bss_compare_mode - BSS compare mode
423  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
424  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
425  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
426  */
427 enum bss_compare_mode {
428         BSS_CMP_REGULAR,
429         BSS_CMP_HIDE_ZLEN,
430         BSS_CMP_HIDE_NUL,
431 };
432 
433 static int cmp_bss(struct cfg80211_bss *a,
434                    struct cfg80211_bss *b,
435                    enum bss_compare_mode mode)
436 {
437         const struct cfg80211_bss_ies *a_ies, *b_ies;
438         const u8 *ie1 = NULL;
439         const u8 *ie2 = NULL;
440         int i, r;
441 
442         if (a->channel != b->channel)
443                 return b->channel->center_freq - a->channel->center_freq;
444 
445         a_ies = rcu_access_pointer(a->ies);
446         if (!a_ies)
447                 return -1;
448         b_ies = rcu_access_pointer(b->ies);
449         if (!b_ies)
450                 return 1;
451 
452         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
453                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
454                                        a_ies->data, a_ies->len);
455         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
456                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
457                                        b_ies->data, b_ies->len);
458         if (ie1 && ie2) {
459                 int mesh_id_cmp;
460 
461                 if (ie1[1] == ie2[1])
462                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
463                 else
464                         mesh_id_cmp = ie2[1] - ie1[1];
465 
466                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
467                                        a_ies->data, a_ies->len);
468                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
469                                        b_ies->data, b_ies->len);
470                 if (ie1 && ie2) {
471                         if (mesh_id_cmp)
472                                 return mesh_id_cmp;
473                         if (ie1[1] != ie2[1])
474                                 return ie2[1] - ie1[1];
475                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
476                 }
477         }
478 
479         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
480         if (r)
481                 return r;
482 
483         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
484         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
485 
486         if (!ie1 && !ie2)
487                 return 0;
488 
489         /*
490          * Note that with "hide_ssid", the function returns a match if
491          * the already-present BSS ("b") is a hidden SSID beacon for
492          * the new BSS ("a").
493          */
494 
495         /* sort missing IE before (left of) present IE */
496         if (!ie1)
497                 return -1;
498         if (!ie2)
499                 return 1;
500 
501         switch (mode) {
502         case BSS_CMP_HIDE_ZLEN:
503                 /*
504                  * In ZLEN mode we assume the BSS entry we're
505                  * looking for has a zero-length SSID. So if
506                  * the one we're looking at right now has that,
507                  * return 0. Otherwise, return the difference
508                  * in length, but since we're looking for the
509                  * 0-length it's really equivalent to returning
510                  * the length of the one we're looking at.
511                  *
512                  * No content comparison is needed as we assume
513                  * the content length is zero.
514                  */
515                 return ie2[1];
516         case BSS_CMP_REGULAR:
517         default:
518                 /* sort by length first, then by contents */
519                 if (ie1[1] != ie2[1])
520                         return ie2[1] - ie1[1];
521                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
522         case BSS_CMP_HIDE_NUL:
523                 if (ie1[1] != ie2[1])
524                         return ie2[1] - ie1[1];
525                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
526                 for (i = 0; i < ie2[1]; i++)
527                         if (ie2[i + 2])
528                                 return -1;
529                 return 0;
530         }
531 }
532 
533 static bool cfg80211_bss_type_match(u16 capability,
534                                     enum ieee80211_band band,
535                                     enum ieee80211_bss_type bss_type)
536 {
537         bool ret = true;
538         u16 mask, val;
539 
540         if (bss_type == IEEE80211_BSS_TYPE_ANY)
541                 return ret;
542 
543         if (band == IEEE80211_BAND_60GHZ) {
544                 mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
545                 switch (bss_type) {
546                 case IEEE80211_BSS_TYPE_ESS:
547                         val = WLAN_CAPABILITY_DMG_TYPE_AP;
548                         break;
549                 case IEEE80211_BSS_TYPE_PBSS:
550                         val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
551                         break;
552                 case IEEE80211_BSS_TYPE_IBSS:
553                         val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
554                         break;
555                 default:
556                         return false;
557                 }
558         } else {
559                 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
560                 switch (bss_type) {
561                 case IEEE80211_BSS_TYPE_ESS:
562                         val = WLAN_CAPABILITY_ESS;
563                         break;
564                 case IEEE80211_BSS_TYPE_IBSS:
565                         val = WLAN_CAPABILITY_IBSS;
566                         break;
567                 case IEEE80211_BSS_TYPE_MBSS:
568                         val = 0;
569                         break;
570                 default:
571                         return false;
572                 }
573         }
574 
575         ret = ((capability & mask) == val);
576         return ret;
577 }
578 
579 /* Returned bss is reference counted and must be cleaned up appropriately. */
580 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
581                                       struct ieee80211_channel *channel,
582                                       const u8 *bssid,
583                                       const u8 *ssid, size_t ssid_len,
584                                       enum ieee80211_bss_type bss_type,
585                                       enum ieee80211_privacy privacy)
586 {
587         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
588         struct cfg80211_internal_bss *bss, *res = NULL;
589         unsigned long now = jiffies;
590         int bss_privacy;
591 
592         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
593                                privacy);
594 
595         spin_lock_bh(&rdev->bss_lock);
596 
597         list_for_each_entry(bss, &rdev->bss_list, list) {
598                 if (!cfg80211_bss_type_match(bss->pub.capability,
599                                              bss->pub.channel->band, bss_type))
600                         continue;
601 
602                 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
603                 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
604                     (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
605                         continue;
606                 if (channel && bss->pub.channel != channel)
607                         continue;
608                 if (!is_valid_ether_addr(bss->pub.bssid))
609                         continue;
610                 /* Don't get expired BSS structs */
611                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
612                     !atomic_read(&bss->hold))
613                         continue;
614                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
615                         res = bss;
616                         bss_ref_get(rdev, res);
617                         break;
618                 }
619         }
620 
621         spin_unlock_bh(&rdev->bss_lock);
622         if (!res)
623                 return NULL;
624         trace_cfg80211_return_bss(&res->pub);
625         return &res->pub;
626 }
627 EXPORT_SYMBOL(cfg80211_get_bss);
628 
629 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
630                           struct cfg80211_internal_bss *bss)
631 {
632         struct rb_node **p = &rdev->bss_tree.rb_node;
633         struct rb_node *parent = NULL;
634         struct cfg80211_internal_bss *tbss;
635         int cmp;
636 
637         while (*p) {
638                 parent = *p;
639                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
640 
641                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
642 
643                 if (WARN_ON(!cmp)) {
644                         /* will sort of leak this BSS */
645                         return;
646                 }
647 
648                 if (cmp < 0)
649                         p = &(*p)->rb_left;
650                 else
651                         p = &(*p)->rb_right;
652         }
653 
654         rb_link_node(&bss->rbn, parent, p);
655         rb_insert_color(&bss->rbn, &rdev->bss_tree);
656 }
657 
658 static struct cfg80211_internal_bss *
659 rb_find_bss(struct cfg80211_registered_device *rdev,
660             struct cfg80211_internal_bss *res,
661             enum bss_compare_mode mode)
662 {
663         struct rb_node *n = rdev->bss_tree.rb_node;
664         struct cfg80211_internal_bss *bss;
665         int r;
666 
667         while (n) {
668                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
669                 r = cmp_bss(&res->pub, &bss->pub, mode);
670 
671                 if (r == 0)
672                         return bss;
673                 else if (r < 0)
674                         n = n->rb_left;
675                 else
676                         n = n->rb_right;
677         }
678 
679         return NULL;
680 }
681 
682 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
683                                    struct cfg80211_internal_bss *new)
684 {
685         const struct cfg80211_bss_ies *ies;
686         struct cfg80211_internal_bss *bss;
687         const u8 *ie;
688         int i, ssidlen;
689         u8 fold = 0;
690 
691         ies = rcu_access_pointer(new->pub.beacon_ies);
692         if (WARN_ON(!ies))
693                 return false;
694 
695         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
696         if (!ie) {
697                 /* nothing to do */
698                 return true;
699         }
700 
701         ssidlen = ie[1];
702         for (i = 0; i < ssidlen; i++)
703                 fold |= ie[2 + i];
704 
705         if (fold) {
706                 /* not a hidden SSID */
707                 return true;
708         }
709 
710         /* This is the bad part ... */
711 
712         list_for_each_entry(bss, &rdev->bss_list, list) {
713                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
714                         continue;
715                 if (bss->pub.channel != new->pub.channel)
716                         continue;
717                 if (bss->pub.scan_width != new->pub.scan_width)
718                         continue;
719                 if (rcu_access_pointer(bss->pub.beacon_ies))
720                         continue;
721                 ies = rcu_access_pointer(bss->pub.ies);
722                 if (!ies)
723                         continue;
724                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
725                 if (!ie)
726                         continue;
727                 if (ssidlen && ie[1] != ssidlen)
728                         continue;
729                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
730                         continue;
731                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
732                         list_del(&bss->hidden_list);
733                 /* combine them */
734                 list_add(&bss->hidden_list, &new->hidden_list);
735                 bss->pub.hidden_beacon_bss = &new->pub;
736                 new->refcount += bss->refcount;
737                 rcu_assign_pointer(bss->pub.beacon_ies,
738                                    new->pub.beacon_ies);
739         }
740 
741         return true;
742 }
743 
744 /* Returned bss is reference counted and must be cleaned up appropriately. */
745 static struct cfg80211_internal_bss *
746 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
747                     struct cfg80211_internal_bss *tmp,
748                     bool signal_valid)
749 {
750         struct cfg80211_internal_bss *found = NULL;
751 
752         if (WARN_ON(!tmp->pub.channel))
753                 return NULL;
754 
755         tmp->ts = jiffies;
756 
757         spin_lock_bh(&rdev->bss_lock);
758 
759         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
760                 spin_unlock_bh(&rdev->bss_lock);
761                 return NULL;
762         }
763 
764         found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
765 
766         if (found) {
767                 /* Update IEs */
768                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
769                         const struct cfg80211_bss_ies *old;
770 
771                         old = rcu_access_pointer(found->pub.proberesp_ies);
772 
773                         rcu_assign_pointer(found->pub.proberesp_ies,
774                                            tmp->pub.proberesp_ies);
775                         /* Override possible earlier Beacon frame IEs */
776                         rcu_assign_pointer(found->pub.ies,
777                                            tmp->pub.proberesp_ies);
778                         if (old)
779                                 kfree_rcu((struct cfg80211_bss_ies *)old,
780                                           rcu_head);
781                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
782                         const struct cfg80211_bss_ies *old;
783                         struct cfg80211_internal_bss *bss;
784 
785                         if (found->pub.hidden_beacon_bss &&
786                             !list_empty(&found->hidden_list)) {
787                                 const struct cfg80211_bss_ies *f;
788 
789                                 /*
790                                  * The found BSS struct is one of the probe
791                                  * response members of a group, but we're
792                                  * receiving a beacon (beacon_ies in the tmp
793                                  * bss is used). This can only mean that the
794                                  * AP changed its beacon from not having an
795                                  * SSID to showing it, which is confusing so
796                                  * drop this information.
797                                  */
798 
799                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
800                                 kfree_rcu((struct cfg80211_bss_ies *)f,
801                                           rcu_head);
802                                 goto drop;
803                         }
804 
805                         old = rcu_access_pointer(found->pub.beacon_ies);
806 
807                         rcu_assign_pointer(found->pub.beacon_ies,
808                                            tmp->pub.beacon_ies);
809 
810                         /* Override IEs if they were from a beacon before */
811                         if (old == rcu_access_pointer(found->pub.ies))
812                                 rcu_assign_pointer(found->pub.ies,
813                                                    tmp->pub.beacon_ies);
814 
815                         /* Assign beacon IEs to all sub entries */
816                         list_for_each_entry(bss, &found->hidden_list,
817                                             hidden_list) {
818                                 const struct cfg80211_bss_ies *ies;
819 
820                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
821                                 WARN_ON(ies != old);
822 
823                                 rcu_assign_pointer(bss->pub.beacon_ies,
824                                                    tmp->pub.beacon_ies);
825                         }
826 
827                         if (old)
828                                 kfree_rcu((struct cfg80211_bss_ies *)old,
829                                           rcu_head);
830                 }
831 
832                 found->pub.beacon_interval = tmp->pub.beacon_interval;
833                 /*
834                  * don't update the signal if beacon was heard on
835                  * adjacent channel.
836                  */
837                 if (signal_valid)
838                         found->pub.signal = tmp->pub.signal;
839                 found->pub.capability = tmp->pub.capability;
840                 found->ts = tmp->ts;
841                 found->ts_boottime = tmp->ts_boottime;
842         } else {
843                 struct cfg80211_internal_bss *new;
844                 struct cfg80211_internal_bss *hidden;
845                 struct cfg80211_bss_ies *ies;
846 
847                 /*
848                  * create a copy -- the "res" variable that is passed in
849                  * is allocated on the stack since it's not needed in the
850                  * more common case of an update
851                  */
852                 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
853                               GFP_ATOMIC);
854                 if (!new) {
855                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
856                         if (ies)
857                                 kfree_rcu(ies, rcu_head);
858                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
859                         if (ies)
860                                 kfree_rcu(ies, rcu_head);
861                         goto drop;
862                 }
863                 memcpy(new, tmp, sizeof(*new));
864                 new->refcount = 1;
865                 INIT_LIST_HEAD(&new->hidden_list);
866 
867                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
868                         hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
869                         if (!hidden)
870                                 hidden = rb_find_bss(rdev, tmp,
871                                                      BSS_CMP_HIDE_NUL);
872                         if (hidden) {
873                                 new->pub.hidden_beacon_bss = &hidden->pub;
874                                 list_add(&new->hidden_list,
875                                          &hidden->hidden_list);
876                                 hidden->refcount++;
877                                 rcu_assign_pointer(new->pub.beacon_ies,
878                                                    hidden->pub.beacon_ies);
879                         }
880                 } else {
881                         /*
882                          * Ok so we found a beacon, and don't have an entry. If
883                          * it's a beacon with hidden SSID, we might be in for an
884                          * expensive search for any probe responses that should
885                          * be grouped with this beacon for updates ...
886                          */
887                         if (!cfg80211_combine_bsses(rdev, new)) {
888                                 kfree(new);
889                                 goto drop;
890                         }
891                 }
892 
893                 list_add_tail(&new->list, &rdev->bss_list);
894                 rb_insert_bss(rdev, new);
895                 found = new;
896         }
897 
898         rdev->bss_generation++;
899         bss_ref_get(rdev, found);
900         spin_unlock_bh(&rdev->bss_lock);
901 
902         return found;
903  drop:
904         spin_unlock_bh(&rdev->bss_lock);
905         return NULL;
906 }
907 
908 static struct ieee80211_channel *
909 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
910                          struct ieee80211_channel *channel)
911 {
912         const u8 *tmp;
913         u32 freq;
914         int channel_number = -1;
915 
916         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
917         if (tmp && tmp[1] == 1) {
918                 channel_number = tmp[2];
919         } else {
920                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
921                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
922                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
923 
924                         channel_number = htop->primary_chan;
925                 }
926         }
927 
928         if (channel_number < 0)
929                 return channel;
930 
931         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
932         channel = ieee80211_get_channel(wiphy, freq);
933         if (!channel)
934                 return NULL;
935         if (channel->flags & IEEE80211_CHAN_DISABLED)
936                 return NULL;
937         return channel;
938 }
939 
940 /* Returned bss is reference counted and must be cleaned up appropriately. */
941 struct cfg80211_bss *
942 cfg80211_inform_bss_data(struct wiphy *wiphy,
943                          struct cfg80211_inform_bss *data,
944                          enum cfg80211_bss_frame_type ftype,
945                          const u8 *bssid, u64 tsf, u16 capability,
946                          u16 beacon_interval, const u8 *ie, size_t ielen,
947                          gfp_t gfp)
948 {
949         struct cfg80211_bss_ies *ies;
950         struct ieee80211_channel *channel;
951         struct cfg80211_internal_bss tmp = {}, *res;
952         int bss_type;
953         bool signal_valid;
954 
955         if (WARN_ON(!wiphy))
956                 return NULL;
957 
958         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
959                     (data->signal < 0 || data->signal > 100)))
960                 return NULL;
961 
962         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan);
963         if (!channel)
964                 return NULL;
965 
966         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
967         tmp.pub.channel = channel;
968         tmp.pub.scan_width = data->scan_width;
969         tmp.pub.signal = data->signal;
970         tmp.pub.beacon_interval = beacon_interval;
971         tmp.pub.capability = capability;
972         tmp.ts_boottime = data->boottime_ns;
973 
974         /*
975          * If we do not know here whether the IEs are from a Beacon or Probe
976          * Response frame, we need to pick one of the options and only use it
977          * with the driver that does not provide the full Beacon/Probe Response
978          * frame. Use Beacon frame pointer to avoid indicating that this should
979          * override the IEs pointer should we have received an earlier
980          * indication of Probe Response data.
981          */
982         ies = kzalloc(sizeof(*ies) + ielen, gfp);
983         if (!ies)
984                 return NULL;
985         ies->len = ielen;
986         ies->tsf = tsf;
987         ies->from_beacon = false;
988         memcpy(ies->data, ie, ielen);
989 
990         switch (ftype) {
991         case CFG80211_BSS_FTYPE_BEACON:
992                 ies->from_beacon = true;
993                 /* fall through to assign */
994         case CFG80211_BSS_FTYPE_UNKNOWN:
995                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
996                 break;
997         case CFG80211_BSS_FTYPE_PRESP:
998                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
999                 break;
1000         }
1001         rcu_assign_pointer(tmp.pub.ies, ies);
1002 
1003         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1004                 wiphy->max_adj_channel_rssi_comp;
1005         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1006         if (!res)
1007                 return NULL;
1008 
1009         if (channel->band == IEEE80211_BAND_60GHZ) {
1010                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1011                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1012                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1013                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1014         } else {
1015                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1016                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1017         }
1018 
1019         trace_cfg80211_return_bss(&res->pub);
1020         /* cfg80211_bss_update gives us a referenced result */
1021         return &res->pub;
1022 }
1023 EXPORT_SYMBOL(cfg80211_inform_bss_data);
1024 
1025 /* cfg80211_inform_bss_width_frame helper */
1026 struct cfg80211_bss *
1027 cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
1028                                struct cfg80211_inform_bss *data,
1029                                struct ieee80211_mgmt *mgmt, size_t len,
1030                                gfp_t gfp)
1031 
1032 {
1033         struct cfg80211_internal_bss tmp = {}, *res;
1034         struct cfg80211_bss_ies *ies;
1035         struct ieee80211_channel *channel;
1036         bool signal_valid;
1037         size_t ielen = len - offsetof(struct ieee80211_mgmt,
1038                                       u.probe_resp.variable);
1039         int bss_type;
1040 
1041         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
1042                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
1043 
1044         trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);
1045 
1046         if (WARN_ON(!mgmt))
1047                 return NULL;
1048 
1049         if (WARN_ON(!wiphy))
1050                 return NULL;
1051 
1052         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1053                     (data->signal < 0 || data->signal > 100)))
1054                 return NULL;
1055 
1056         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
1057                 return NULL;
1058 
1059         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
1060                                            ielen, data->chan);
1061         if (!channel)
1062                 return NULL;
1063 
1064         ies = kzalloc(sizeof(*ies) + ielen, gfp);
1065         if (!ies)
1066                 return NULL;
1067         ies->len = ielen;
1068         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1069         ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1070         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1071 
1072         if (ieee80211_is_probe_resp(mgmt->frame_control))
1073                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1074         else
1075                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1076         rcu_assign_pointer(tmp.pub.ies, ies);
1077         
1078         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1079         tmp.pub.channel = channel;
1080         tmp.pub.scan_width = data->scan_width;
1081         tmp.pub.signal = data->signal;
1082         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1083         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1084         tmp.ts_boottime = data->boottime_ns;
1085 
1086         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1087                 wiphy->max_adj_channel_rssi_comp;
1088         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1089         if (!res)
1090                 return NULL;
1091 
1092         if (channel->band == IEEE80211_BAND_60GHZ) {
1093                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1094                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1095                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1096                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1097         } else {
1098                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1099                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1100         }
1101 
1102         trace_cfg80211_return_bss(&res->pub);
1103         /* cfg80211_bss_update gives us a referenced result */
1104         return &res->pub;
1105 }
1106 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
1107 
1108 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1109 {
1110         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1111         struct cfg80211_internal_bss *bss;
1112 
1113         if (!pub)
1114                 return;
1115 
1116         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1117 
1118         spin_lock_bh(&rdev->bss_lock);
1119         bss_ref_get(rdev, bss);
1120         spin_unlock_bh(&rdev->bss_lock);
1121 }
1122 EXPORT_SYMBOL(cfg80211_ref_bss);
1123 
1124 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1125 {
1126         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1127         struct cfg80211_internal_bss *bss;
1128 
1129         if (!pub)
1130                 return;
1131 
1132         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1133 
1134         spin_lock_bh(&rdev->bss_lock);
1135         bss_ref_put(rdev, bss);
1136         spin_unlock_bh(&rdev->bss_lock);
1137 }
1138 EXPORT_SYMBOL(cfg80211_put_bss);
1139 
1140 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1141 {
1142         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1143         struct cfg80211_internal_bss *bss;
1144 
1145         if (WARN_ON(!pub))
1146                 return;
1147 
1148         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1149 
1150         spin_lock_bh(&rdev->bss_lock);
1151         if (!list_empty(&bss->list)) {
1152                 if (__cfg80211_unlink_bss(rdev, bss))
1153                         rdev->bss_generation++;
1154         }
1155         spin_unlock_bh(&rdev->bss_lock);
1156 }
1157 EXPORT_SYMBOL(cfg80211_unlink_bss);
1158 
1159 #ifdef CONFIG_CFG80211_WEXT
1160 static struct cfg80211_registered_device *
1161 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1162 {
1163         struct cfg80211_registered_device *rdev;
1164         struct net_device *dev;
1165 
1166         ASSERT_RTNL();
1167 
1168         dev = dev_get_by_index(net, ifindex);
1169         if (!dev)
1170                 return ERR_PTR(-ENODEV);
1171         if (dev->ieee80211_ptr)
1172                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1173         else
1174                 rdev = ERR_PTR(-ENODEV);
1175         dev_put(dev);
1176         return rdev;
1177 }
1178 
1179 int cfg80211_wext_siwscan(struct net_device *dev,
1180                           struct iw_request_info *info,
1181                           union iwreq_data *wrqu, char *extra)
1182 {
1183         struct cfg80211_registered_device *rdev;
1184         struct wiphy *wiphy;
1185         struct iw_scan_req *wreq = NULL;
1186         struct cfg80211_scan_request *creq = NULL;
1187         int i, err, n_channels = 0;
1188         enum ieee80211_band band;
1189 
1190         if (!netif_running(dev))
1191                 return -ENETDOWN;
1192 
1193         if (wrqu->data.length == sizeof(struct iw_scan_req))
1194                 wreq = (struct iw_scan_req *)extra;
1195 
1196         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1197 
1198         if (IS_ERR(rdev))
1199                 return PTR_ERR(rdev);
1200 
1201         if (rdev->scan_req || rdev->scan_msg) {
1202                 err = -EBUSY;
1203                 goto out;
1204         }
1205 
1206         wiphy = &rdev->wiphy;
1207 
1208         /* Determine number of channels, needed to allocate creq */
1209         if (wreq && wreq->num_channels)
1210                 n_channels = wreq->num_channels;
1211         else
1212                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1213 
1214         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1215                        n_channels * sizeof(void *),
1216                        GFP_ATOMIC);
1217         if (!creq) {
1218                 err = -ENOMEM;
1219                 goto out;
1220         }
1221 
1222         creq->wiphy = wiphy;
1223         creq->wdev = dev->ieee80211_ptr;
1224         /* SSIDs come after channels */
1225         creq->ssids = (void *)&creq->channels[n_channels];
1226         creq->n_channels = n_channels;
1227         creq->n_ssids = 1;
1228         creq->scan_start = jiffies;
1229 
1230         /* translate "Scan on frequencies" request */
1231         i = 0;
1232         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1233                 int j;
1234 
1235                 if (!wiphy->bands[band])
1236                         continue;
1237 
1238                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1239                         /* ignore disabled channels */
1240                         if (wiphy->bands[band]->channels[j].flags &
1241                                                 IEEE80211_CHAN_DISABLED)
1242                                 continue;
1243 
1244                         /* If we have a wireless request structure and the
1245                          * wireless request specifies frequencies, then search
1246                          * for the matching hardware channel.
1247                          */
1248                         if (wreq && wreq->num_channels) {
1249                                 int k;
1250                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1251                                 for (k = 0; k < wreq->num_channels; k++) {
1252                                         struct iw_freq *freq =
1253                                                 &wreq->channel_list[k];
1254                                         int wext_freq =
1255                                                 cfg80211_wext_freq(freq);
1256 
1257                                         if (wext_freq == wiphy_freq)
1258                                                 goto wext_freq_found;
1259                                 }
1260                                 goto wext_freq_not_found;
1261                         }
1262 
1263                 wext_freq_found:
1264                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1265                         i++;
1266                 wext_freq_not_found: ;
1267                 }
1268         }
1269         /* No channels found? */
1270         if (!i) {
1271                 err = -EINVAL;
1272                 goto out;
1273         }
1274 
1275         /* Set real number of channels specified in creq->channels[] */
1276         creq->n_channels = i;
1277 
1278         /* translate "Scan for SSID" request */
1279         if (wreq) {
1280                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1281                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1282                                 err = -EINVAL;
1283                                 goto out;
1284                         }
1285                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1286                         creq->ssids[0].ssid_len = wreq->essid_len;
1287                 }
1288                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1289                         creq->n_ssids = 0;
1290         }
1291 
1292         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1293                 if (wiphy->bands[i])
1294                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1295 
1296         rdev->scan_req = creq;
1297         err = rdev_scan(rdev, creq);
1298         if (err) {
1299                 rdev->scan_req = NULL;
1300                 /* creq will be freed below */
1301         } else {
1302                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1303                 /* creq now owned by driver */
1304                 creq = NULL;
1305                 dev_hold(dev);
1306         }
1307  out:
1308         kfree(creq);
1309         return err;
1310 }
1311 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
1312 
1313 static char *ieee80211_scan_add_ies(struct iw_request_info *info,
1314                                     const struct cfg80211_bss_ies *ies,
1315                                     char *current_ev, char *end_buf)
1316 {
1317         const u8 *pos, *end, *next;
1318         struct iw_event iwe;
1319 
1320         if (!ies)
1321                 return current_ev;
1322 
1323         /*
1324          * If needed, fragment the IEs buffer (at IE boundaries) into short
1325          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1326          */
1327         pos = ies->data;
1328         end = pos + ies->len;
1329 
1330         while (end - pos > IW_GENERIC_IE_MAX) {
1331                 next = pos + 2 + pos[1];
1332                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1333                         next = next + 2 + next[1];
1334 
1335                 memset(&iwe, 0, sizeof(iwe));
1336                 iwe.cmd = IWEVGENIE;
1337                 iwe.u.data.length = next - pos;
1338                 current_ev = iwe_stream_add_point_check(info, current_ev,
1339                                                         end_buf, &iwe,
1340                                                         (void *)pos);
1341                 if (IS_ERR(current_ev))
1342                         return current_ev;
1343                 pos = next;
1344         }
1345 
1346         if (end > pos) {
1347                 memset(&iwe, 0, sizeof(iwe));
1348                 iwe.cmd = IWEVGENIE;
1349                 iwe.u.data.length = end - pos;
1350                 current_ev = iwe_stream_add_point_check(info, current_ev,
1351                                                         end_buf, &iwe,
1352                                                         (void *)pos);
1353                 if (IS_ERR(current_ev))
1354                         return current_ev;
1355         }
1356 
1357         return current_ev;
1358 }
1359 
1360 static char *
1361 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1362               struct cfg80211_internal_bss *bss, char *current_ev,
1363               char *end_buf)
1364 {
1365         const struct cfg80211_bss_ies *ies;
1366         struct iw_event iwe;
1367         const u8 *ie;
1368         u8 buf[50];
1369         u8 *cfg, *p, *tmp;
1370         int rem, i, sig;
1371         bool ismesh = false;
1372 
1373         memset(&iwe, 0, sizeof(iwe));
1374         iwe.cmd = SIOCGIWAP;
1375         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1376         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1377         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1378                                                 IW_EV_ADDR_LEN);
1379         if (IS_ERR(current_ev))
1380                 return current_ev;
1381 
1382         memset(&iwe, 0, sizeof(iwe));
1383         iwe.cmd = SIOCGIWFREQ;
1384         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1385         iwe.u.freq.e = 0;
1386         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1387                                                 IW_EV_FREQ_LEN);
1388         if (IS_ERR(current_ev))
1389                 return current_ev;
1390 
1391         memset(&iwe, 0, sizeof(iwe));
1392         iwe.cmd = SIOCGIWFREQ;
1393         iwe.u.freq.m = bss->pub.channel->center_freq;
1394         iwe.u.freq.e = 6;
1395         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1396                                                 IW_EV_FREQ_LEN);
1397         if (IS_ERR(current_ev))
1398                 return current_ev;
1399 
1400         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1401                 memset(&iwe, 0, sizeof(iwe));
1402                 iwe.cmd = IWEVQUAL;
1403                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1404                                      IW_QUAL_NOISE_INVALID |
1405                                      IW_QUAL_QUAL_UPDATED;
1406                 switch (wiphy->signal_type) {
1407                 case CFG80211_SIGNAL_TYPE_MBM:
1408                         sig = bss->pub.signal / 100;
1409                         iwe.u.qual.level = sig;
1410                         iwe.u.qual.updated |= IW_QUAL_DBM;
1411                         if (sig < -110)         /* rather bad */
1412                                 sig = -110;
1413                         else if (sig > -40)     /* perfect */
1414                                 sig = -40;
1415                         /* will give a range of 0 .. 70 */
1416                         iwe.u.qual.qual = sig + 110;
1417                         break;
1418                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1419                         iwe.u.qual.level = bss->pub.signal;
1420                         /* will give range 0 .. 100 */
1421                         iwe.u.qual.qual = bss->pub.signal;
1422                         break;
1423                 default:
1424                         /* not reached */
1425                         break;
1426                 }
1427                 current_ev = iwe_stream_add_event_check(info, current_ev,
1428                                                         end_buf, &iwe,
1429                                                         IW_EV_QUAL_LEN);
1430                 if (IS_ERR(current_ev))
1431                         return current_ev;
1432         }
1433 
1434         memset(&iwe, 0, sizeof(iwe));
1435         iwe.cmd = SIOCGIWENCODE;
1436         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1437                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1438         else
1439                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1440         iwe.u.data.length = 0;
1441         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1442                                                 &iwe, "");
1443         if (IS_ERR(current_ev))
1444                 return current_ev;
1445 
1446         rcu_read_lock();
1447         ies = rcu_dereference(bss->pub.ies);
1448         rem = ies->len;
1449         ie = ies->data;
1450 
1451         while (rem >= 2) {
1452                 /* invalid data */
1453                 if (ie[1] > rem - 2)
1454                         break;
1455 
1456                 switch (ie[0]) {
1457                 case WLAN_EID_SSID:
1458                         memset(&iwe, 0, sizeof(iwe));
1459                         iwe.cmd = SIOCGIWESSID;
1460                         iwe.u.data.length = ie[1];
1461                         iwe.u.data.flags = 1;
1462                         current_ev = iwe_stream_add_point_check(info,
1463                                                                 current_ev,
1464                                                                 end_buf, &iwe,
1465                                                                 (u8 *)ie + 2);
1466                         if (IS_ERR(current_ev))
1467                                 goto unlock;
1468                         break;
1469                 case WLAN_EID_MESH_ID:
1470                         memset(&iwe, 0, sizeof(iwe));
1471                         iwe.cmd = SIOCGIWESSID;
1472                         iwe.u.data.length = ie[1];
1473                         iwe.u.data.flags = 1;
1474                         current_ev = iwe_stream_add_point_check(info,
1475                                                                 current_ev,
1476                                                                 end_buf, &iwe,
1477                                                                 (u8 *)ie + 2);
1478                         if (IS_ERR(current_ev))
1479                                 goto unlock;
1480                         break;
1481                 case WLAN_EID_MESH_CONFIG:
1482                         ismesh = true;
1483                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1484                                 break;
1485                         cfg = (u8 *)ie + 2;
1486                         memset(&iwe, 0, sizeof(iwe));
1487                         iwe.cmd = IWEVCUSTOM;
1488                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1489                                 "0x%02X", cfg[0]);
1490                         iwe.u.data.length = strlen(buf);
1491                         current_ev = iwe_stream_add_point_check(info,
1492                                                                 current_ev,
1493                                                                 end_buf,
1494                                                                 &iwe, buf);
1495                         if (IS_ERR(current_ev))
1496                                 goto unlock;
1497                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1498                                 cfg[1]);
1499                         iwe.u.data.length = strlen(buf);
1500                         current_ev = iwe_stream_add_point_check(info,
1501                                                                 current_ev,
1502                                                                 end_buf,
1503                                                                 &iwe, buf);
1504                         if (IS_ERR(current_ev))
1505                                 goto unlock;
1506                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1507                                 cfg[2]);
1508                         iwe.u.data.length = strlen(buf);
1509                         current_ev = iwe_stream_add_point_check(info,
1510                                                                 current_ev,
1511                                                                 end_buf,
1512                                                                 &iwe, buf);
1513                         if (IS_ERR(current_ev))
1514                                 goto unlock;
1515                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1516                         iwe.u.data.length = strlen(buf);
1517                         current_ev = iwe_stream_add_point_check(info,
1518                                                                 current_ev,
1519                                                                 end_buf,
1520                                                                 &iwe, buf);
1521                         if (IS_ERR(current_ev))
1522                                 goto unlock;
1523                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1524                         iwe.u.data.length = strlen(buf);
1525                         current_ev = iwe_stream_add_point_check(info,
1526                                                                 current_ev,
1527                                                                 end_buf,
1528                                                                 &iwe, buf);
1529                         if (IS_ERR(current_ev))
1530                                 goto unlock;
1531                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1532                         iwe.u.data.length = strlen(buf);
1533                         current_ev = iwe_stream_add_point_check(info,
1534                                                                 current_ev,
1535                                                                 end_buf,
1536                                                                 &iwe, buf);
1537                         if (IS_ERR(current_ev))
1538                                 goto unlock;
1539                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1540                         iwe.u.data.length = strlen(buf);
1541                         current_ev = iwe_stream_add_point_check(info,
1542                                                                 current_ev,
1543                                                                 end_buf,
1544                                                                 &iwe, buf);
1545                         if (IS_ERR(current_ev))
1546                                 goto unlock;
1547                         break;
1548                 case WLAN_EID_SUPP_RATES:
1549                 case WLAN_EID_EXT_SUPP_RATES:
1550                         /* display all supported rates in readable format */
1551                         p = current_ev + iwe_stream_lcp_len(info);
1552 
1553                         memset(&iwe, 0, sizeof(iwe));
1554                         iwe.cmd = SIOCGIWRATE;
1555                         /* Those two flags are ignored... */
1556                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1557 
1558                         for (i = 0; i < ie[1]; i++) {
1559                                 iwe.u.bitrate.value =
1560                                         ((ie[i + 2] & 0x7f) * 500000);
1561                                 tmp = p;
1562                                 p = iwe_stream_add_value(info, current_ev, p,
1563                                                          end_buf, &iwe,
1564                                                          IW_EV_PARAM_LEN);
1565                                 if (p == tmp) {
1566                                         current_ev = ERR_PTR(-E2BIG);
1567                                         goto unlock;
1568                                 }
1569                         }
1570                         current_ev = p;
1571                         break;
1572                 }
1573                 rem -= ie[1] + 2;
1574                 ie += ie[1] + 2;
1575         }
1576 
1577         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1578             ismesh) {
1579                 memset(&iwe, 0, sizeof(iwe));
1580                 iwe.cmd = SIOCGIWMODE;
1581                 if (ismesh)
1582                         iwe.u.mode = IW_MODE_MESH;
1583                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1584                         iwe.u.mode = IW_MODE_MASTER;
1585                 else
1586                         iwe.u.mode = IW_MODE_ADHOC;
1587                 current_ev = iwe_stream_add_event_check(info, current_ev,
1588                                                         end_buf, &iwe,
1589                                                         IW_EV_UINT_LEN);
1590                 if (IS_ERR(current_ev))
1591                         goto unlock;
1592         }
1593 
1594         memset(&iwe, 0, sizeof(iwe));
1595         iwe.cmd = IWEVCUSTOM;
1596         sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1597         iwe.u.data.length = strlen(buf);
1598         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1599                                                 &iwe, buf);
1600         if (IS_ERR(current_ev))
1601                 goto unlock;
1602         memset(&iwe, 0, sizeof(iwe));
1603         iwe.cmd = IWEVCUSTOM;
1604         sprintf(buf, " Last beacon: %ums ago",
1605                 elapsed_jiffies_msecs(bss->ts));
1606         iwe.u.data.length = strlen(buf);
1607         current_ev = iwe_stream_add_point_check(info, current_ev,
1608                                                 end_buf, &iwe, buf);
1609         if (IS_ERR(current_ev))
1610                 goto unlock;
1611 
1612         current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
1613 
1614  unlock:
1615         rcu_read_unlock();
1616         return current_ev;
1617 }
1618 
1619 
1620 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1621                                   struct iw_request_info *info,
1622                                   char *buf, size_t len)
1623 {
1624         char *current_ev = buf;
1625         char *end_buf = buf + len;
1626         struct cfg80211_internal_bss *bss;
1627         int err = 0;
1628 
1629         spin_lock_bh(&rdev->bss_lock);
1630         cfg80211_bss_expire(rdev);
1631 
1632         list_for_each_entry(bss, &rdev->bss_list, list) {
1633                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1634                         err = -E2BIG;
1635                         break;
1636                 }
1637                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1638                                            current_ev, end_buf);
1639                 if (IS_ERR(current_ev)) {
1640                         err = PTR_ERR(current_ev);
1641                         break;
1642                 }
1643         }
1644         spin_unlock_bh(&rdev->bss_lock);
1645 
1646         if (err)
1647                 return err;
1648         return current_ev - buf;
1649 }
1650 
1651 
1652 int cfg80211_wext_giwscan(struct net_device *dev,
1653                           struct iw_request_info *info,
1654                           struct iw_point *data, char *extra)
1655 {
1656         struct cfg80211_registered_device *rdev;
1657         int res;
1658 
1659         if (!netif_running(dev))
1660                 return -ENETDOWN;
1661 
1662         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1663 
1664         if (IS_ERR(rdev))
1665                 return PTR_ERR(rdev);
1666 
1667         if (rdev->scan_req || rdev->scan_msg)
1668                 return -EAGAIN;
1669 
1670         res = ieee80211_scan_results(rdev, info, extra, data->length);
1671         data->length = 0;
1672         if (res >= 0) {
1673                 data->length = res;
1674                 res = 0;
1675         }
1676 
1677         return res;
1678 }
1679 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
1680 #endif
1681 

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