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
61static 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
85static 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
99static 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
118static 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
143static 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
165void ___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
227void __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
239void 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}
248EXPORT_SYMBOL(cfg80211_scan_done);
249
250void __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
277void 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}
286EXPORT_SYMBOL(cfg80211_sched_scan_results);
287
288void 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}
298EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
299
300void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
301{
302	rtnl_lock();
303	cfg80211_sched_scan_stopped_rtnl(wiphy);
304	rtnl_unlock();
305}
306EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
307
308int __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
336void 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
348void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
349{
350	__cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
351}
352
353const 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}
365EXPORT_SYMBOL(cfg80211_find_ie);
366
367const 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;
391cont:
392		pos += 2 + ie->len;
393	}
394	return NULL;
395}
396EXPORT_SYMBOL(cfg80211_find_vendor_ie);
397
398static 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 */
427enum bss_compare_mode {
428	BSS_CMP_REGULAR,
429	BSS_CMP_HIDE_ZLEN,
430	BSS_CMP_HIDE_NUL,
431};
432
433static 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
533static 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. */
580struct 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}
627EXPORT_SYMBOL(cfg80211_get_bss);
628
629static 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
658static struct cfg80211_internal_bss *
659rb_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
682static 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. */
745static struct cfg80211_internal_bss *
746cfg80211_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
908static struct ieee80211_channel *
909cfg80211_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. */
941struct cfg80211_bss *
942cfg80211_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}
1023EXPORT_SYMBOL(cfg80211_inform_bss_data);
1024
1025/* cfg80211_inform_bss_width_frame helper */
1026struct cfg80211_bss *
1027cfg80211_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}
1106EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);
1107
1108void 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}
1122EXPORT_SYMBOL(cfg80211_ref_bss);
1123
1124void 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}
1138EXPORT_SYMBOL(cfg80211_put_bss);
1139
1140void 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}
1157EXPORT_SYMBOL(cfg80211_unlink_bss);
1158
1159#ifdef CONFIG_CFG80211_WEXT
1160static struct cfg80211_registered_device *
1161cfg80211_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
1179int 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}
1311EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
1312
1313static 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
1360static char *
1361ieee80211_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
1620static 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
1652int 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}
1679EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
1680#endif
1681