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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, int 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         if (WARN_ON(oui_type > 0xff))
375                 return NULL;
376 
377         while (pos < end) {
378                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
379                                        end - pos);
380                 if (!pos)
381                         return NULL;
382 
383                 ie = (struct ieee80211_vendor_ie *)pos;
384 
385                 /* make sure we can access ie->len */
386                 BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
387 
388                 if (ie->len < sizeof(*ie))
389                         goto cont;
390 
391                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
392                 if (ie_oui == oui &&
393                     (oui_type < 0 || ie->oui_type == oui_type))
394                         return pos;
395 cont:
396                 pos += 2 + ie->len;
397         }
398         return NULL;
399 }
400 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
401 
402 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
403                    const u8 *ssid, size_t ssid_len)
404 {
405         const struct cfg80211_bss_ies *ies;
406         const u8 *ssidie;
407 
408         if (bssid && !ether_addr_equal(a->bssid, bssid))
409                 return false;
410 
411         if (!ssid)
412                 return true;
413 
414         ies = rcu_access_pointer(a->ies);
415         if (!ies)
416                 return false;
417         ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
418         if (!ssidie)
419                 return false;
420         if (ssidie[1] != ssid_len)
421                 return false;
422         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
423 }
424 
425 /**
426  * enum bss_compare_mode - BSS compare mode
427  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
428  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
429  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
430  */
431 enum bss_compare_mode {
432         BSS_CMP_REGULAR,
433         BSS_CMP_HIDE_ZLEN,
434         BSS_CMP_HIDE_NUL,
435 };
436 
437 static int cmp_bss(struct cfg80211_bss *a,
438                    struct cfg80211_bss *b,
439                    enum bss_compare_mode mode)
440 {
441         const struct cfg80211_bss_ies *a_ies, *b_ies;
442         const u8 *ie1 = NULL;
443         const u8 *ie2 = NULL;
444         int i, r;
445 
446         if (a->channel != b->channel)
447                 return b->channel->center_freq - a->channel->center_freq;
448 
449         a_ies = rcu_access_pointer(a->ies);
450         if (!a_ies)
451                 return -1;
452         b_ies = rcu_access_pointer(b->ies);
453         if (!b_ies)
454                 return 1;
455 
456         if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
457                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
458                                        a_ies->data, a_ies->len);
459         if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
460                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
461                                        b_ies->data, b_ies->len);
462         if (ie1 && ie2) {
463                 int mesh_id_cmp;
464 
465                 if (ie1[1] == ie2[1])
466                         mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
467                 else
468                         mesh_id_cmp = ie2[1] - ie1[1];
469 
470                 ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
471                                        a_ies->data, a_ies->len);
472                 ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
473                                        b_ies->data, b_ies->len);
474                 if (ie1 && ie2) {
475                         if (mesh_id_cmp)
476                                 return mesh_id_cmp;
477                         if (ie1[1] != ie2[1])
478                                 return ie2[1] - ie1[1];
479                         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
480                 }
481         }
482 
483         r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
484         if (r)
485                 return r;
486 
487         ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
488         ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
489 
490         if (!ie1 && !ie2)
491                 return 0;
492 
493         /*
494          * Note that with "hide_ssid", the function returns a match if
495          * the already-present BSS ("b") is a hidden SSID beacon for
496          * the new BSS ("a").
497          */
498 
499         /* sort missing IE before (left of) present IE */
500         if (!ie1)
501                 return -1;
502         if (!ie2)
503                 return 1;
504 
505         switch (mode) {
506         case BSS_CMP_HIDE_ZLEN:
507                 /*
508                  * In ZLEN mode we assume the BSS entry we're
509                  * looking for has a zero-length SSID. So if
510                  * the one we're looking at right now has that,
511                  * return 0. Otherwise, return the difference
512                  * in length, but since we're looking for the
513                  * 0-length it's really equivalent to returning
514                  * the length of the one we're looking at.
515                  *
516                  * No content comparison is needed as we assume
517                  * the content length is zero.
518                  */
519                 return ie2[1];
520         case BSS_CMP_REGULAR:
521         default:
522                 /* sort by length first, then by contents */
523                 if (ie1[1] != ie2[1])
524                         return ie2[1] - ie1[1];
525                 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
526         case BSS_CMP_HIDE_NUL:
527                 if (ie1[1] != ie2[1])
528                         return ie2[1] - ie1[1];
529                 /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
530                 for (i = 0; i < ie2[1]; i++)
531                         if (ie2[i + 2])
532                                 return -1;
533                 return 0;
534         }
535 }
536 
537 static bool cfg80211_bss_type_match(u16 capability,
538                                     enum nl80211_band band,
539                                     enum ieee80211_bss_type bss_type)
540 {
541         bool ret = true;
542         u16 mask, val;
543 
544         if (bss_type == IEEE80211_BSS_TYPE_ANY)
545                 return ret;
546 
547         if (band == NL80211_BAND_60GHZ) {
548                 mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
549                 switch (bss_type) {
550                 case IEEE80211_BSS_TYPE_ESS:
551                         val = WLAN_CAPABILITY_DMG_TYPE_AP;
552                         break;
553                 case IEEE80211_BSS_TYPE_PBSS:
554                         val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
555                         break;
556                 case IEEE80211_BSS_TYPE_IBSS:
557                         val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
558                         break;
559                 default:
560                         return false;
561                 }
562         } else {
563                 mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
564                 switch (bss_type) {
565                 case IEEE80211_BSS_TYPE_ESS:
566                         val = WLAN_CAPABILITY_ESS;
567                         break;
568                 case IEEE80211_BSS_TYPE_IBSS:
569                         val = WLAN_CAPABILITY_IBSS;
570                         break;
571                 case IEEE80211_BSS_TYPE_MBSS:
572                         val = 0;
573                         break;
574                 default:
575                         return false;
576                 }
577         }
578 
579         ret = ((capability & mask) == val);
580         return ret;
581 }
582 
583 /* Returned bss is reference counted and must be cleaned up appropriately. */
584 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
585                                       struct ieee80211_channel *channel,
586                                       const u8 *bssid,
587                                       const u8 *ssid, size_t ssid_len,
588                                       enum ieee80211_bss_type bss_type,
589                                       enum ieee80211_privacy privacy)
590 {
591         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
592         struct cfg80211_internal_bss *bss, *res = NULL;
593         unsigned long now = jiffies;
594         int bss_privacy;
595 
596         trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
597                                privacy);
598 
599         spin_lock_bh(&rdev->bss_lock);
600 
601         list_for_each_entry(bss, &rdev->bss_list, list) {
602                 if (!cfg80211_bss_type_match(bss->pub.capability,
603                                              bss->pub.channel->band, bss_type))
604                         continue;
605 
606                 bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
607                 if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
608                     (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
609                         continue;
610                 if (channel && bss->pub.channel != channel)
611                         continue;
612                 if (!is_valid_ether_addr(bss->pub.bssid))
613                         continue;
614                 /* Don't get expired BSS structs */
615                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
616                     !atomic_read(&bss->hold))
617                         continue;
618                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
619                         res = bss;
620                         bss_ref_get(rdev, res);
621                         break;
622                 }
623         }
624 
625         spin_unlock_bh(&rdev->bss_lock);
626         if (!res)
627                 return NULL;
628         trace_cfg80211_return_bss(&res->pub);
629         return &res->pub;
630 }
631 EXPORT_SYMBOL(cfg80211_get_bss);
632 
633 static void rb_insert_bss(struct cfg80211_registered_device *rdev,
634                           struct cfg80211_internal_bss *bss)
635 {
636         struct rb_node **p = &rdev->bss_tree.rb_node;
637         struct rb_node *parent = NULL;
638         struct cfg80211_internal_bss *tbss;
639         int cmp;
640 
641         while (*p) {
642                 parent = *p;
643                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
644 
645                 cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
646 
647                 if (WARN_ON(!cmp)) {
648                         /* will sort of leak this BSS */
649                         return;
650                 }
651 
652                 if (cmp < 0)
653                         p = &(*p)->rb_left;
654                 else
655                         p = &(*p)->rb_right;
656         }
657 
658         rb_link_node(&bss->rbn, parent, p);
659         rb_insert_color(&bss->rbn, &rdev->bss_tree);
660 }
661 
662 static struct cfg80211_internal_bss *
663 rb_find_bss(struct cfg80211_registered_device *rdev,
664             struct cfg80211_internal_bss *res,
665             enum bss_compare_mode mode)
666 {
667         struct rb_node *n = rdev->bss_tree.rb_node;
668         struct cfg80211_internal_bss *bss;
669         int r;
670 
671         while (n) {
672                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
673                 r = cmp_bss(&res->pub, &bss->pub, mode);
674 
675                 if (r == 0)
676                         return bss;
677                 else if (r < 0)
678                         n = n->rb_left;
679                 else
680                         n = n->rb_right;
681         }
682 
683         return NULL;
684 }
685 
686 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
687                                    struct cfg80211_internal_bss *new)
688 {
689         const struct cfg80211_bss_ies *ies;
690         struct cfg80211_internal_bss *bss;
691         const u8 *ie;
692         int i, ssidlen;
693         u8 fold = 0;
694 
695         ies = rcu_access_pointer(new->pub.beacon_ies);
696         if (WARN_ON(!ies))
697                 return false;
698 
699         ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
700         if (!ie) {
701                 /* nothing to do */
702                 return true;
703         }
704 
705         ssidlen = ie[1];
706         for (i = 0; i < ssidlen; i++)
707                 fold |= ie[2 + i];
708 
709         if (fold) {
710                 /* not a hidden SSID */
711                 return true;
712         }
713 
714         /* This is the bad part ... */
715 
716         list_for_each_entry(bss, &rdev->bss_list, list) {
717                 if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
718                         continue;
719                 if (bss->pub.channel != new->pub.channel)
720                         continue;
721                 if (bss->pub.scan_width != new->pub.scan_width)
722                         continue;
723                 if (rcu_access_pointer(bss->pub.beacon_ies))
724                         continue;
725                 ies = rcu_access_pointer(bss->pub.ies);
726                 if (!ies)
727                         continue;
728                 ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
729                 if (!ie)
730                         continue;
731                 if (ssidlen && ie[1] != ssidlen)
732                         continue;
733                 if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
734                         continue;
735                 if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
736                         list_del(&bss->hidden_list);
737                 /* combine them */
738                 list_add(&bss->hidden_list, &new->hidden_list);
739                 bss->pub.hidden_beacon_bss = &new->pub;
740                 new->refcount += bss->refcount;
741                 rcu_assign_pointer(bss->pub.beacon_ies,
742                                    new->pub.beacon_ies);
743         }
744 
745         return true;
746 }
747 
748 /* Returned bss is reference counted and must be cleaned up appropriately. */
749 static struct cfg80211_internal_bss *
750 cfg80211_bss_update(struct cfg80211_registered_device *rdev,
751                     struct cfg80211_internal_bss *tmp,
752                     bool signal_valid)
753 {
754         struct cfg80211_internal_bss *found = NULL;
755 
756         if (WARN_ON(!tmp->pub.channel))
757                 return NULL;
758 
759         tmp->ts = jiffies;
760 
761         spin_lock_bh(&rdev->bss_lock);
762 
763         if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
764                 spin_unlock_bh(&rdev->bss_lock);
765                 return NULL;
766         }
767 
768         found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
769 
770         if (found) {
771                 /* Update IEs */
772                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
773                         const struct cfg80211_bss_ies *old;
774 
775                         old = rcu_access_pointer(found->pub.proberesp_ies);
776 
777                         rcu_assign_pointer(found->pub.proberesp_ies,
778                                            tmp->pub.proberesp_ies);
779                         /* Override possible earlier Beacon frame IEs */
780                         rcu_assign_pointer(found->pub.ies,
781                                            tmp->pub.proberesp_ies);
782                         if (old)
783                                 kfree_rcu((struct cfg80211_bss_ies *)old,
784                                           rcu_head);
785                 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
786                         const struct cfg80211_bss_ies *old;
787                         struct cfg80211_internal_bss *bss;
788 
789                         if (found->pub.hidden_beacon_bss &&
790                             !list_empty(&found->hidden_list)) {
791                                 const struct cfg80211_bss_ies *f;
792 
793                                 /*
794                                  * The found BSS struct is one of the probe
795                                  * response members of a group, but we're
796                                  * receiving a beacon (beacon_ies in the tmp
797                                  * bss is used). This can only mean that the
798                                  * AP changed its beacon from not having an
799                                  * SSID to showing it, which is confusing so
800                                  * drop this information.
801                                  */
802 
803                                 f = rcu_access_pointer(tmp->pub.beacon_ies);
804                                 kfree_rcu((struct cfg80211_bss_ies *)f,
805                                           rcu_head);
806                                 goto drop;
807                         }
808 
809                         old = rcu_access_pointer(found->pub.beacon_ies);
810 
811                         rcu_assign_pointer(found->pub.beacon_ies,
812                                            tmp->pub.beacon_ies);
813 
814                         /* Override IEs if they were from a beacon before */
815                         if (old == rcu_access_pointer(found->pub.ies))
816                                 rcu_assign_pointer(found->pub.ies,
817                                                    tmp->pub.beacon_ies);
818 
819                         /* Assign beacon IEs to all sub entries */
820                         list_for_each_entry(bss, &found->hidden_list,
821                                             hidden_list) {
822                                 const struct cfg80211_bss_ies *ies;
823 
824                                 ies = rcu_access_pointer(bss->pub.beacon_ies);
825                                 WARN_ON(ies != old);
826 
827                                 rcu_assign_pointer(bss->pub.beacon_ies,
828                                                    tmp->pub.beacon_ies);
829                         }
830 
831                         if (old)
832                                 kfree_rcu((struct cfg80211_bss_ies *)old,
833                                           rcu_head);
834                 }
835 
836                 found->pub.beacon_interval = tmp->pub.beacon_interval;
837                 /*
838                  * don't update the signal if beacon was heard on
839                  * adjacent channel.
840                  */
841                 if (signal_valid)
842                         found->pub.signal = tmp->pub.signal;
843                 found->pub.capability = tmp->pub.capability;
844                 found->ts = tmp->ts;
845                 found->ts_boottime = tmp->ts_boottime;
846         } else {
847                 struct cfg80211_internal_bss *new;
848                 struct cfg80211_internal_bss *hidden;
849                 struct cfg80211_bss_ies *ies;
850 
851                 /*
852                  * create a copy -- the "res" variable that is passed in
853                  * is allocated on the stack since it's not needed in the
854                  * more common case of an update
855                  */
856                 new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
857                               GFP_ATOMIC);
858                 if (!new) {
859                         ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
860                         if (ies)
861                                 kfree_rcu(ies, rcu_head);
862                         ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
863                         if (ies)
864                                 kfree_rcu(ies, rcu_head);
865                         goto drop;
866                 }
867                 memcpy(new, tmp, sizeof(*new));
868                 new->refcount = 1;
869                 INIT_LIST_HEAD(&new->hidden_list);
870 
871                 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
872                         hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
873                         if (!hidden)
874                                 hidden = rb_find_bss(rdev, tmp,
875                                                      BSS_CMP_HIDE_NUL);
876                         if (hidden) {
877                                 new->pub.hidden_beacon_bss = &hidden->pub;
878                                 list_add(&new->hidden_list,
879                                          &hidden->hidden_list);
880                                 hidden->refcount++;
881                                 rcu_assign_pointer(new->pub.beacon_ies,
882                                                    hidden->pub.beacon_ies);
883                         }
884                 } else {
885                         /*
886                          * Ok so we found a beacon, and don't have an entry. If
887                          * it's a beacon with hidden SSID, we might be in for an
888                          * expensive search for any probe responses that should
889                          * be grouped with this beacon for updates ...
890                          */
891                         if (!cfg80211_combine_bsses(rdev, new)) {
892                                 kfree(new);
893                                 goto drop;
894                         }
895                 }
896 
897                 list_add_tail(&new->list, &rdev->bss_list);
898                 rb_insert_bss(rdev, new);
899                 found = new;
900         }
901 
902         rdev->bss_generation++;
903         bss_ref_get(rdev, found);
904         spin_unlock_bh(&rdev->bss_lock);
905 
906         return found;
907  drop:
908         spin_unlock_bh(&rdev->bss_lock);
909         return NULL;
910 }
911 
912 static struct ieee80211_channel *
913 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
914                          struct ieee80211_channel *channel)
915 {
916         const u8 *tmp;
917         u32 freq;
918         int channel_number = -1;
919 
920         tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
921         if (tmp && tmp[1] == 1) {
922                 channel_number = tmp[2];
923         } else {
924                 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
925                 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
926                         struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
927 
928                         channel_number = htop->primary_chan;
929                 }
930         }
931 
932         if (channel_number < 0)
933                 return channel;
934 
935         freq = ieee80211_channel_to_frequency(channel_number, channel->band);
936         channel = ieee80211_get_channel(wiphy, freq);
937         if (!channel)
938                 return NULL;
939         if (channel->flags & IEEE80211_CHAN_DISABLED)
940                 return NULL;
941         return channel;
942 }
943 
944 /* Returned bss is reference counted and must be cleaned up appropriately. */
945 struct cfg80211_bss *
946 cfg80211_inform_bss_data(struct wiphy *wiphy,
947                          struct cfg80211_inform_bss *data,
948                          enum cfg80211_bss_frame_type ftype,
949                          const u8 *bssid, u64 tsf, u16 capability,
950                          u16 beacon_interval, const u8 *ie, size_t ielen,
951                          gfp_t gfp)
952 {
953         struct cfg80211_bss_ies *ies;
954         struct ieee80211_channel *channel;
955         struct cfg80211_internal_bss tmp = {}, *res;
956         int bss_type;
957         bool signal_valid;
958 
959         if (WARN_ON(!wiphy))
960                 return NULL;
961 
962         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
963                     (data->signal < 0 || data->signal > 100)))
964                 return NULL;
965 
966         channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan);
967         if (!channel)
968                 return NULL;
969 
970         memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
971         tmp.pub.channel = channel;
972         tmp.pub.scan_width = data->scan_width;
973         tmp.pub.signal = data->signal;
974         tmp.pub.beacon_interval = beacon_interval;
975         tmp.pub.capability = capability;
976         tmp.ts_boottime = data->boottime_ns;
977 
978         /*
979          * If we do not know here whether the IEs are from a Beacon or Probe
980          * Response frame, we need to pick one of the options and only use it
981          * with the driver that does not provide the full Beacon/Probe Response
982          * frame. Use Beacon frame pointer to avoid indicating that this should
983          * override the IEs pointer should we have received an earlier
984          * indication of Probe Response data.
985          */
986         ies = kzalloc(sizeof(*ies) + ielen, gfp);
987         if (!ies)
988                 return NULL;
989         ies->len = ielen;
990         ies->tsf = tsf;
991         ies->from_beacon = false;
992         memcpy(ies->data, ie, ielen);
993 
994         switch (ftype) {
995         case CFG80211_BSS_FTYPE_BEACON:
996                 ies->from_beacon = true;
997                 /* fall through to assign */
998         case CFG80211_BSS_FTYPE_UNKNOWN:
999                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1000                 break;
1001         case CFG80211_BSS_FTYPE_PRESP:
1002                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1003                 break;
1004         }
1005         rcu_assign_pointer(tmp.pub.ies, ies);
1006 
1007         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1008                 wiphy->max_adj_channel_rssi_comp;
1009         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1010         if (!res)
1011                 return NULL;
1012 
1013         if (channel->band == NL80211_BAND_60GHZ) {
1014                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1015                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1016                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1017                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1018         } else {
1019                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1020                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1021         }
1022 
1023         trace_cfg80211_return_bss(&res->pub);
1024         /* cfg80211_bss_update gives us a referenced result */
1025         return &res->pub;
1026 }
1027 EXPORT_SYMBOL(cfg80211_inform_bss_data);
1028 
1029 /* cfg80211_inform_bss_width_frame helper */
1030 struct cfg80211_bss *
1031 cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
1032                                struct cfg80211_inform_bss *data,
1033                                struct ieee80211_mgmt *mgmt, size_t len,
1034                                gfp_t gfp)
1035 
1036 {
1037         struct cfg80211_internal_bss tmp = {}, *res;
1038         struct cfg80211_bss_ies *ies;
1039         struct ieee80211_channel *channel;
1040         bool signal_valid;
1041         size_t ielen = len - offsetof(struct ieee80211_mgmt,
1042                                       u.probe_resp.variable);
1043         int bss_type;
1044 
1045         BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
1046                         offsetof(struct ieee80211_mgmt, u.beacon.variable));
1047 
1048         trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len);
1049 
1050         if (WARN_ON(!mgmt))
1051                 return NULL;
1052 
1053         if (WARN_ON(!wiphy))
1054                 return NULL;
1055 
1056         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
1057                     (data->signal < 0 || data->signal > 100)))
1058                 return NULL;
1059 
1060         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
1061                 return NULL;
1062 
1063         channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
1064                                            ielen, data->chan);
1065         if (!channel)
1066                 return NULL;
1067 
1068         ies = kzalloc(sizeof(*ies) + ielen, gfp);
1069         if (!ies)
1070                 return NULL;
1071         ies->len = ielen;
1072         ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
1073         ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
1074         memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
1075 
1076         if (ieee80211_is_probe_resp(mgmt->frame_control))
1077                 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
1078         else
1079                 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
1080         rcu_assign_pointer(tmp.pub.ies, ies);
1081         
1082         memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
1083         tmp.pub.channel = channel;
1084         tmp.pub.scan_width = data->scan_width;
1085         tmp.pub.signal = data->signal;
1086         tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
1087         tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
1088         tmp.ts_boottime = data->boottime_ns;
1089 
1090         signal_valid = abs(data->chan->center_freq - channel->center_freq) <=
1091                 wiphy->max_adj_channel_rssi_comp;
1092         res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
1093         if (!res)
1094                 return NULL;
1095 
1096         if (channel->band == NL80211_BAND_60GHZ) {
1097                 bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
1098                 if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
1099                     bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
1100                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1101         } else {
1102                 if (res->pub.capability & WLAN_CAPABILITY_ESS)
1103                         regulatory_hint_found_beacon(wiphy, channel, gfp);
1104         }
1105 
1106         trace_cfg80211_return_bss(&res->pub);
1107         /* cfg80211_bss_update gives us a referenced result */
1108         return &res->pub;
1109 }
1110 EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
1111 
1112 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1113 {
1114         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1115         struct cfg80211_internal_bss *bss;
1116 
1117         if (!pub)
1118                 return;
1119 
1120         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1121 
1122         spin_lock_bh(&rdev->bss_lock);
1123         bss_ref_get(rdev, bss);
1124         spin_unlock_bh(&rdev->bss_lock);
1125 }
1126 EXPORT_SYMBOL(cfg80211_ref_bss);
1127 
1128 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1129 {
1130         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1131         struct cfg80211_internal_bss *bss;
1132 
1133         if (!pub)
1134                 return;
1135 
1136         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1137 
1138         spin_lock_bh(&rdev->bss_lock);
1139         bss_ref_put(rdev, bss);
1140         spin_unlock_bh(&rdev->bss_lock);
1141 }
1142 EXPORT_SYMBOL(cfg80211_put_bss);
1143 
1144 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1145 {
1146         struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
1147         struct cfg80211_internal_bss *bss;
1148 
1149         if (WARN_ON(!pub))
1150                 return;
1151 
1152         bss = container_of(pub, struct cfg80211_internal_bss, pub);
1153 
1154         spin_lock_bh(&rdev->bss_lock);
1155         if (!list_empty(&bss->list)) {
1156                 if (__cfg80211_unlink_bss(rdev, bss))
1157                         rdev->bss_generation++;
1158         }
1159         spin_unlock_bh(&rdev->bss_lock);
1160 }
1161 EXPORT_SYMBOL(cfg80211_unlink_bss);
1162 
1163 #ifdef CONFIG_CFG80211_WEXT
1164 static struct cfg80211_registered_device *
1165 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1166 {
1167         struct cfg80211_registered_device *rdev;
1168         struct net_device *dev;
1169 
1170         ASSERT_RTNL();
1171 
1172         dev = dev_get_by_index(net, ifindex);
1173         if (!dev)
1174                 return ERR_PTR(-ENODEV);
1175         if (dev->ieee80211_ptr)
1176                 rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
1177         else
1178                 rdev = ERR_PTR(-ENODEV);
1179         dev_put(dev);
1180         return rdev;
1181 }
1182 
1183 int cfg80211_wext_siwscan(struct net_device *dev,
1184                           struct iw_request_info *info,
1185                           union iwreq_data *wrqu, char *extra)
1186 {
1187         struct cfg80211_registered_device *rdev;
1188         struct wiphy *wiphy;
1189         struct iw_scan_req *wreq = NULL;
1190         struct cfg80211_scan_request *creq = NULL;
1191         int i, err, n_channels = 0;
1192         enum nl80211_band band;
1193 
1194         if (!netif_running(dev))
1195                 return -ENETDOWN;
1196 
1197         if (wrqu->data.length == sizeof(struct iw_scan_req))
1198                 wreq = (struct iw_scan_req *)extra;
1199 
1200         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1201 
1202         if (IS_ERR(rdev))
1203                 return PTR_ERR(rdev);
1204 
1205         if (rdev->scan_req || rdev->scan_msg) {
1206                 err = -EBUSY;
1207                 goto out;
1208         }
1209 
1210         wiphy = &rdev->wiphy;
1211 
1212         /* Determine number of channels, needed to allocate creq */
1213         if (wreq && wreq->num_channels)
1214                 n_channels = wreq->num_channels;
1215         else
1216                 n_channels = ieee80211_get_num_supported_channels(wiphy);
1217 
1218         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1219                        n_channels * sizeof(void *),
1220                        GFP_ATOMIC);
1221         if (!creq) {
1222                 err = -ENOMEM;
1223                 goto out;
1224         }
1225 
1226         creq->wiphy = wiphy;
1227         creq->wdev = dev->ieee80211_ptr;
1228         /* SSIDs come after channels */
1229         creq->ssids = (void *)&creq->channels[n_channels];
1230         creq->n_channels = n_channels;
1231         creq->n_ssids = 1;
1232         creq->scan_start = jiffies;
1233 
1234         /* translate "Scan on frequencies" request */
1235         i = 0;
1236         for (band = 0; band < NUM_NL80211_BANDS; band++) {
1237                 int j;
1238 
1239                 if (!wiphy->bands[band])
1240                         continue;
1241 
1242                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1243                         /* ignore disabled channels */
1244                         if (wiphy->bands[band]->channels[j].flags &
1245                                                 IEEE80211_CHAN_DISABLED)
1246                                 continue;
1247 
1248                         /* If we have a wireless request structure and the
1249                          * wireless request specifies frequencies, then search
1250                          * for the matching hardware channel.
1251                          */
1252                         if (wreq && wreq->num_channels) {
1253                                 int k;
1254                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1255                                 for (k = 0; k < wreq->num_channels; k++) {
1256                                         struct iw_freq *freq =
1257                                                 &wreq->channel_list[k];
1258                                         int wext_freq =
1259                                                 cfg80211_wext_freq(freq);
1260 
1261                                         if (wext_freq == wiphy_freq)
1262                                                 goto wext_freq_found;
1263                                 }
1264                                 goto wext_freq_not_found;
1265                         }
1266 
1267                 wext_freq_found:
1268                         creq->channels[i] = &wiphy->bands[band]->channels[j];
1269                         i++;
1270                 wext_freq_not_found: ;
1271                 }
1272         }
1273         /* No channels found? */
1274         if (!i) {
1275                 err = -EINVAL;
1276                 goto out;
1277         }
1278 
1279         /* Set real number of channels specified in creq->channels[] */
1280         creq->n_channels = i;
1281 
1282         /* translate "Scan for SSID" request */
1283         if (wreq) {
1284                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1285                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1286                                 err = -EINVAL;
1287                                 goto out;
1288                         }
1289                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1290                         creq->ssids[0].ssid_len = wreq->essid_len;
1291                 }
1292                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1293                         creq->n_ssids = 0;
1294         }
1295 
1296         for (i = 0; i < NUM_NL80211_BANDS; i++)
1297                 if (wiphy->bands[i])
1298                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1299 
1300         eth_broadcast_addr(creq->bssid);
1301 
1302         rdev->scan_req = creq;
1303         err = rdev_scan(rdev, creq);
1304         if (err) {
1305                 rdev->scan_req = NULL;
1306                 /* creq will be freed below */
1307         } else {
1308                 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1309                 /* creq now owned by driver */
1310                 creq = NULL;
1311                 dev_hold(dev);
1312         }
1313  out:
1314         kfree(creq);
1315         return err;
1316 }
1317 EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
1318 
1319 static char *ieee80211_scan_add_ies(struct iw_request_info *info,
1320                                     const struct cfg80211_bss_ies *ies,
1321                                     char *current_ev, char *end_buf)
1322 {
1323         const u8 *pos, *end, *next;
1324         struct iw_event iwe;
1325 
1326         if (!ies)
1327                 return current_ev;
1328 
1329         /*
1330          * If needed, fragment the IEs buffer (at IE boundaries) into short
1331          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1332          */
1333         pos = ies->data;
1334         end = pos + ies->len;
1335 
1336         while (end - pos > IW_GENERIC_IE_MAX) {
1337                 next = pos + 2 + pos[1];
1338                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1339                         next = next + 2 + next[1];
1340 
1341                 memset(&iwe, 0, sizeof(iwe));
1342                 iwe.cmd = IWEVGENIE;
1343                 iwe.u.data.length = next - pos;
1344                 current_ev = iwe_stream_add_point_check(info, current_ev,
1345                                                         end_buf, &iwe,
1346                                                         (void *)pos);
1347                 if (IS_ERR(current_ev))
1348                         return current_ev;
1349                 pos = next;
1350         }
1351 
1352         if (end > pos) {
1353                 memset(&iwe, 0, sizeof(iwe));
1354                 iwe.cmd = IWEVGENIE;
1355                 iwe.u.data.length = end - pos;
1356                 current_ev = iwe_stream_add_point_check(info, current_ev,
1357                                                         end_buf, &iwe,
1358                                                         (void *)pos);
1359                 if (IS_ERR(current_ev))
1360                         return current_ev;
1361         }
1362 
1363         return current_ev;
1364 }
1365 
1366 static char *
1367 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1368               struct cfg80211_internal_bss *bss, char *current_ev,
1369               char *end_buf)
1370 {
1371         const struct cfg80211_bss_ies *ies;
1372         struct iw_event iwe;
1373         const u8 *ie;
1374         u8 buf[50];
1375         u8 *cfg, *p, *tmp;
1376         int rem, i, sig;
1377         bool ismesh = false;
1378 
1379         memset(&iwe, 0, sizeof(iwe));
1380         iwe.cmd = SIOCGIWAP;
1381         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1382         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1383         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1384                                                 IW_EV_ADDR_LEN);
1385         if (IS_ERR(current_ev))
1386                 return current_ev;
1387 
1388         memset(&iwe, 0, sizeof(iwe));
1389         iwe.cmd = SIOCGIWFREQ;
1390         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1391         iwe.u.freq.e = 0;
1392         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1393                                                 IW_EV_FREQ_LEN);
1394         if (IS_ERR(current_ev))
1395                 return current_ev;
1396 
1397         memset(&iwe, 0, sizeof(iwe));
1398         iwe.cmd = SIOCGIWFREQ;
1399         iwe.u.freq.m = bss->pub.channel->center_freq;
1400         iwe.u.freq.e = 6;
1401         current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
1402                                                 IW_EV_FREQ_LEN);
1403         if (IS_ERR(current_ev))
1404                 return current_ev;
1405 
1406         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1407                 memset(&iwe, 0, sizeof(iwe));
1408                 iwe.cmd = IWEVQUAL;
1409                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1410                                      IW_QUAL_NOISE_INVALID |
1411                                      IW_QUAL_QUAL_UPDATED;
1412                 switch (wiphy->signal_type) {
1413                 case CFG80211_SIGNAL_TYPE_MBM:
1414                         sig = bss->pub.signal / 100;
1415                         iwe.u.qual.level = sig;
1416                         iwe.u.qual.updated |= IW_QUAL_DBM;
1417                         if (sig < -110)         /* rather bad */
1418                                 sig = -110;
1419                         else if (sig > -40)     /* perfect */
1420                                 sig = -40;
1421                         /* will give a range of 0 .. 70 */
1422                         iwe.u.qual.qual = sig + 110;
1423                         break;
1424                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1425                         iwe.u.qual.level = bss->pub.signal;
1426                         /* will give range 0 .. 100 */
1427                         iwe.u.qual.qual = bss->pub.signal;
1428                         break;
1429                 default:
1430                         /* not reached */
1431                         break;
1432                 }
1433                 current_ev = iwe_stream_add_event_check(info, current_ev,
1434                                                         end_buf, &iwe,
1435                                                         IW_EV_QUAL_LEN);
1436                 if (IS_ERR(current_ev))
1437                         return current_ev;
1438         }
1439 
1440         memset(&iwe, 0, sizeof(iwe));
1441         iwe.cmd = SIOCGIWENCODE;
1442         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1443                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1444         else
1445                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1446         iwe.u.data.length = 0;
1447         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1448                                                 &iwe, "");
1449         if (IS_ERR(current_ev))
1450                 return current_ev;
1451 
1452         rcu_read_lock();
1453         ies = rcu_dereference(bss->pub.ies);
1454         rem = ies->len;
1455         ie = ies->data;
1456 
1457         while (rem >= 2) {
1458                 /* invalid data */
1459                 if (ie[1] > rem - 2)
1460                         break;
1461 
1462                 switch (ie[0]) {
1463                 case WLAN_EID_SSID:
1464                         memset(&iwe, 0, sizeof(iwe));
1465                         iwe.cmd = SIOCGIWESSID;
1466                         iwe.u.data.length = ie[1];
1467                         iwe.u.data.flags = 1;
1468                         current_ev = iwe_stream_add_point_check(info,
1469                                                                 current_ev,
1470                                                                 end_buf, &iwe,
1471                                                                 (u8 *)ie + 2);
1472                         if (IS_ERR(current_ev))
1473                                 goto unlock;
1474                         break;
1475                 case WLAN_EID_MESH_ID:
1476                         memset(&iwe, 0, sizeof(iwe));
1477                         iwe.cmd = SIOCGIWESSID;
1478                         iwe.u.data.length = ie[1];
1479                         iwe.u.data.flags = 1;
1480                         current_ev = iwe_stream_add_point_check(info,
1481                                                                 current_ev,
1482                                                                 end_buf, &iwe,
1483                                                                 (u8 *)ie + 2);
1484                         if (IS_ERR(current_ev))
1485                                 goto unlock;
1486                         break;
1487                 case WLAN_EID_MESH_CONFIG:
1488                         ismesh = true;
1489                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1490                                 break;
1491                         cfg = (u8 *)ie + 2;
1492                         memset(&iwe, 0, sizeof(iwe));
1493                         iwe.cmd = IWEVCUSTOM;
1494                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1495                                 "0x%02X", cfg[0]);
1496                         iwe.u.data.length = strlen(buf);
1497                         current_ev = iwe_stream_add_point_check(info,
1498                                                                 current_ev,
1499                                                                 end_buf,
1500                                                                 &iwe, buf);
1501                         if (IS_ERR(current_ev))
1502                                 goto unlock;
1503                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1504                                 cfg[1]);
1505                         iwe.u.data.length = strlen(buf);
1506                         current_ev = iwe_stream_add_point_check(info,
1507                                                                 current_ev,
1508                                                                 end_buf,
1509                                                                 &iwe, buf);
1510                         if (IS_ERR(current_ev))
1511                                 goto unlock;
1512                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1513                                 cfg[2]);
1514                         iwe.u.data.length = strlen(buf);
1515                         current_ev = iwe_stream_add_point_check(info,
1516                                                                 current_ev,
1517                                                                 end_buf,
1518                                                                 &iwe, buf);
1519                         if (IS_ERR(current_ev))
1520                                 goto unlock;
1521                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1522                         iwe.u.data.length = strlen(buf);
1523                         current_ev = iwe_stream_add_point_check(info,
1524                                                                 current_ev,
1525                                                                 end_buf,
1526                                                                 &iwe, buf);
1527                         if (IS_ERR(current_ev))
1528                                 goto unlock;
1529                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1530                         iwe.u.data.length = strlen(buf);
1531                         current_ev = iwe_stream_add_point_check(info,
1532                                                                 current_ev,
1533                                                                 end_buf,
1534                                                                 &iwe, buf);
1535                         if (IS_ERR(current_ev))
1536                                 goto unlock;
1537                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1538                         iwe.u.data.length = strlen(buf);
1539                         current_ev = iwe_stream_add_point_check(info,
1540                                                                 current_ev,
1541                                                                 end_buf,
1542                                                                 &iwe, buf);
1543                         if (IS_ERR(current_ev))
1544                                 goto unlock;
1545                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1546                         iwe.u.data.length = strlen(buf);
1547                         current_ev = iwe_stream_add_point_check(info,
1548                                                                 current_ev,
1549                                                                 end_buf,
1550                                                                 &iwe, buf);
1551                         if (IS_ERR(current_ev))
1552                                 goto unlock;
1553                         break;
1554                 case WLAN_EID_SUPP_RATES:
1555                 case WLAN_EID_EXT_SUPP_RATES:
1556                         /* display all supported rates in readable format */
1557                         p = current_ev + iwe_stream_lcp_len(info);
1558 
1559                         memset(&iwe, 0, sizeof(iwe));
1560                         iwe.cmd = SIOCGIWRATE;
1561                         /* Those two flags are ignored... */
1562                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1563 
1564                         for (i = 0; i < ie[1]; i++) {
1565                                 iwe.u.bitrate.value =
1566                                         ((ie[i + 2] & 0x7f) * 500000);
1567                                 tmp = p;
1568                                 p = iwe_stream_add_value(info, current_ev, p,
1569                                                          end_buf, &iwe,
1570                                                          IW_EV_PARAM_LEN);
1571                                 if (p == tmp) {
1572                                         current_ev = ERR_PTR(-E2BIG);
1573                                         goto unlock;
1574                                 }
1575                         }
1576                         current_ev = p;
1577                         break;
1578                 }
1579                 rem -= ie[1] + 2;
1580                 ie += ie[1] + 2;
1581         }
1582 
1583         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1584             ismesh) {
1585                 memset(&iwe, 0, sizeof(iwe));
1586                 iwe.cmd = SIOCGIWMODE;
1587                 if (ismesh)
1588                         iwe.u.mode = IW_MODE_MESH;
1589                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1590                         iwe.u.mode = IW_MODE_MASTER;
1591                 else
1592                         iwe.u.mode = IW_MODE_ADHOC;
1593                 current_ev = iwe_stream_add_event_check(info, current_ev,
1594                                                         end_buf, &iwe,
1595                                                         IW_EV_UINT_LEN);
1596                 if (IS_ERR(current_ev))
1597                         goto unlock;
1598         }
1599 
1600         memset(&iwe, 0, sizeof(iwe));
1601         iwe.cmd = IWEVCUSTOM;
1602         sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1603         iwe.u.data.length = strlen(buf);
1604         current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
1605                                                 &iwe, buf);
1606         if (IS_ERR(current_ev))
1607                 goto unlock;
1608         memset(&iwe, 0, sizeof(iwe));
1609         iwe.cmd = IWEVCUSTOM;
1610         sprintf(buf, " Last beacon: %ums ago",
1611                 elapsed_jiffies_msecs(bss->ts));
1612         iwe.u.data.length = strlen(buf);
1613         current_ev = iwe_stream_add_point_check(info, current_ev,
1614                                                 end_buf, &iwe, buf);
1615         if (IS_ERR(current_ev))
1616                 goto unlock;
1617 
1618         current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
1619 
1620  unlock:
1621         rcu_read_unlock();
1622         return current_ev;
1623 }
1624 
1625 
1626 static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
1627                                   struct iw_request_info *info,
1628                                   char *buf, size_t len)
1629 {
1630         char *current_ev = buf;
1631         char *end_buf = buf + len;
1632         struct cfg80211_internal_bss *bss;
1633         int err = 0;
1634 
1635         spin_lock_bh(&rdev->bss_lock);
1636         cfg80211_bss_expire(rdev);
1637 
1638         list_for_each_entry(bss, &rdev->bss_list, list) {
1639                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1640                         err = -E2BIG;
1641                         break;
1642                 }
1643                 current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
1644                                            current_ev, end_buf);
1645                 if (IS_ERR(current_ev)) {
1646                         err = PTR_ERR(current_ev);
1647                         break;
1648                 }
1649         }
1650         spin_unlock_bh(&rdev->bss_lock);
1651 
1652         if (err)
1653                 return err;
1654         return current_ev - buf;
1655 }
1656 
1657 
1658 int cfg80211_wext_giwscan(struct net_device *dev,
1659                           struct iw_request_info *info,
1660                           struct iw_point *data, char *extra)
1661 {
1662         struct cfg80211_registered_device *rdev;
1663         int res;
1664 
1665         if (!netif_running(dev))
1666                 return -ENETDOWN;
1667 
1668         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1669 
1670         if (IS_ERR(rdev))
1671                 return PTR_ERR(rdev);
1672 
1673         if (rdev->scan_req || rdev->scan_msg)
1674                 return -EAGAIN;
1675 
1676         res = ieee80211_scan_results(rdev, info, extra, data->length);
1677         data->length = 0;
1678         if (res >= 0) {
1679                 data->length = res;
1680                 res = 0;
1681         }
1682 
1683         return res;
1684 }
1685 EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
1686 #endif
1687 

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