scan.c revision e60d7443e00a72a2c056950cdaab79c7b077f3d4
1/*
2 * cfg80211 scan result handling
3 *
4 * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
5 */
6#include <linux/kernel.h>
7#include <linux/module.h>
8#include <linux/netdevice.h>
9#include <linux/wireless.h>
10#include <linux/nl80211.h>
11#include <linux/etherdevice.h>
12#include <net/arp.h>
13#include <net/cfg80211.h>
14#include <net/iw_handler.h>
15#include "core.h"
16#include "nl80211.h"
17#include "wext-compat.h"
18
19#define IEEE80211_SCAN_RESULT_EXPIRE	(15 * HZ)
20
21void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
22{
23	struct cfg80211_scan_request *request;
24	struct net_device *dev;
25#ifdef CONFIG_CFG80211_WEXT
26	union iwreq_data wrqu;
27#endif
28
29	ASSERT_RDEV_LOCK(rdev);
30
31	request = rdev->scan_req;
32
33	if (!request)
34		return;
35
36	dev = request->dev;
37
38	/*
39	 * This must be before sending the other events!
40	 * Otherwise, wpa_supplicant gets completely confused with
41	 * wext events.
42	 */
43	cfg80211_sme_scan_done(dev);
44
45	if (request->aborted)
46		nl80211_send_scan_aborted(rdev, dev);
47	else
48		nl80211_send_scan_done(rdev, dev);
49
50#ifdef CONFIG_CFG80211_WEXT
51	if (!request->aborted) {
52		memset(&wrqu, 0, sizeof(wrqu));
53
54		wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
55	}
56#endif
57
58	dev_put(dev);
59
60	rdev->scan_req = NULL;
61
62	/*
63	 * OK. If this is invoked with "leak" then we can't
64	 * free this ... but we've cleaned it up anyway. The
65	 * driver failed to call the scan_done callback, so
66	 * all bets are off, it might still be trying to use
67	 * the scan request or not ... if it accesses the dev
68	 * in there (it shouldn't anyway) then it may crash.
69	 */
70	if (!leak)
71		kfree(request);
72}
73
74void __cfg80211_scan_done(struct work_struct *wk)
75{
76	struct cfg80211_registered_device *rdev;
77
78	rdev = container_of(wk, struct cfg80211_registered_device,
79			    scan_done_wk);
80
81	cfg80211_lock_rdev(rdev);
82	___cfg80211_scan_done(rdev, false);
83	cfg80211_unlock_rdev(rdev);
84}
85
86void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
87{
88	WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
89
90	request->aborted = aborted;
91	queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
92}
93EXPORT_SYMBOL(cfg80211_scan_done);
94
95static void bss_release(struct kref *ref)
96{
97	struct cfg80211_internal_bss *bss;
98
99	bss = container_of(ref, struct cfg80211_internal_bss, ref);
100	if (bss->pub.free_priv)
101		bss->pub.free_priv(&bss->pub);
102
103	if (bss->ies_allocated)
104		kfree(bss->pub.information_elements);
105
106	BUG_ON(atomic_read(&bss->hold));
107
108	kfree(bss);
109}
110
111/* must hold dev->bss_lock! */
112void cfg80211_bss_age(struct cfg80211_registered_device *dev,
113                      unsigned long age_secs)
114{
115	struct cfg80211_internal_bss *bss;
116	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
117
118	list_for_each_entry(bss, &dev->bss_list, list) {
119		bss->ts -= age_jiffies;
120	}
121}
122
123/* must hold dev->bss_lock! */
124void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
125{
126	struct cfg80211_internal_bss *bss, *tmp;
127	bool expired = false;
128
129	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
130		if (atomic_read(&bss->hold))
131			continue;
132		if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
133			continue;
134		list_del(&bss->list);
135		rb_erase(&bss->rbn, &dev->bss_tree);
136		kref_put(&bss->ref, bss_release);
137		expired = true;
138	}
139
140	if (expired)
141		dev->bss_generation++;
142}
143
144static u8 *find_ie(u8 num, u8 *ies, int len)
145{
146	while (len > 2 && ies[0] != num) {
147		len -= ies[1] + 2;
148		ies += ies[1] + 2;
149	}
150	if (len < 2)
151		return NULL;
152	if (len < 2 + ies[1])
153		return NULL;
154	return ies;
155}
156
157static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
158{
159	const u8 *ie1 = find_ie(num, ies1, len1);
160	const u8 *ie2 = find_ie(num, ies2, len2);
161	int r;
162
163	if (!ie1 && !ie2)
164		return 0;
165	if (!ie1 || !ie2)
166		return -1;
167
168	r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
169	if (r == 0 && ie1[1] != ie2[1])
170		return ie2[1] - ie1[1];
171	return r;
172}
173
174static bool is_bss(struct cfg80211_bss *a,
175		   const u8 *bssid,
176		   const u8 *ssid, size_t ssid_len)
177{
178	const u8 *ssidie;
179
180	if (bssid && compare_ether_addr(a->bssid, bssid))
181		return false;
182
183	if (!ssid)
184		return true;
185
186	ssidie = find_ie(WLAN_EID_SSID,
187			 a->information_elements,
188			 a->len_information_elements);
189	if (!ssidie)
190		return false;
191	if (ssidie[1] != ssid_len)
192		return false;
193	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
194}
195
196static bool is_mesh(struct cfg80211_bss *a,
197		    const u8 *meshid, size_t meshidlen,
198		    const u8 *meshcfg)
199{
200	const u8 *ie;
201
202	if (!is_zero_ether_addr(a->bssid))
203		return false;
204
205	ie = find_ie(WLAN_EID_MESH_ID,
206		     a->information_elements,
207		     a->len_information_elements);
208	if (!ie)
209		return false;
210	if (ie[1] != meshidlen)
211		return false;
212	if (memcmp(ie + 2, meshid, meshidlen))
213		return false;
214
215	ie = find_ie(WLAN_EID_MESH_CONFIG,
216		     a->information_elements,
217		     a->len_information_elements);
218	if (!ie)
219		return false;
220	if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
221		return false;
222
223	/*
224	 * Ignore mesh capability (last two bytes of the IE) when
225	 * comparing since that may differ between stations taking
226	 * part in the same mesh.
227	 */
228	return memcmp(ie + 2, meshcfg,
229	    sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
230}
231
232static int cmp_bss(struct cfg80211_bss *a,
233		   struct cfg80211_bss *b)
234{
235	int r;
236
237	if (a->channel != b->channel)
238		return b->channel->center_freq - a->channel->center_freq;
239
240	r = memcmp(a->bssid, b->bssid, ETH_ALEN);
241	if (r)
242		return r;
243
244	if (is_zero_ether_addr(a->bssid)) {
245		r = cmp_ies(WLAN_EID_MESH_ID,
246			    a->information_elements,
247			    a->len_information_elements,
248			    b->information_elements,
249			    b->len_information_elements);
250		if (r)
251			return r;
252		return cmp_ies(WLAN_EID_MESH_CONFIG,
253			       a->information_elements,
254			       a->len_information_elements,
255			       b->information_elements,
256			       b->len_information_elements);
257	}
258
259	return cmp_ies(WLAN_EID_SSID,
260		       a->information_elements,
261		       a->len_information_elements,
262		       b->information_elements,
263		       b->len_information_elements);
264}
265
266struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
267				      struct ieee80211_channel *channel,
268				      const u8 *bssid,
269				      const u8 *ssid, size_t ssid_len,
270				      u16 capa_mask, u16 capa_val)
271{
272	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
273	struct cfg80211_internal_bss *bss, *res = NULL;
274
275	spin_lock_bh(&dev->bss_lock);
276
277	list_for_each_entry(bss, &dev->bss_list, list) {
278		if ((bss->pub.capability & capa_mask) != capa_val)
279			continue;
280		if (channel && bss->pub.channel != channel)
281			continue;
282		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
283			res = bss;
284			kref_get(&res->ref);
285			break;
286		}
287	}
288
289	spin_unlock_bh(&dev->bss_lock);
290	if (!res)
291		return NULL;
292	return &res->pub;
293}
294EXPORT_SYMBOL(cfg80211_get_bss);
295
296struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
297				       struct ieee80211_channel *channel,
298				       const u8 *meshid, size_t meshidlen,
299				       const u8 *meshcfg)
300{
301	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
302	struct cfg80211_internal_bss *bss, *res = NULL;
303
304	spin_lock_bh(&dev->bss_lock);
305
306	list_for_each_entry(bss, &dev->bss_list, list) {
307		if (channel && bss->pub.channel != channel)
308			continue;
309		if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
310			res = bss;
311			kref_get(&res->ref);
312			break;
313		}
314	}
315
316	spin_unlock_bh(&dev->bss_lock);
317	if (!res)
318		return NULL;
319	return &res->pub;
320}
321EXPORT_SYMBOL(cfg80211_get_mesh);
322
323
324static void rb_insert_bss(struct cfg80211_registered_device *dev,
325			  struct cfg80211_internal_bss *bss)
326{
327	struct rb_node **p = &dev->bss_tree.rb_node;
328	struct rb_node *parent = NULL;
329	struct cfg80211_internal_bss *tbss;
330	int cmp;
331
332	while (*p) {
333		parent = *p;
334		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
335
336		cmp = cmp_bss(&bss->pub, &tbss->pub);
337
338		if (WARN_ON(!cmp)) {
339			/* will sort of leak this BSS */
340			return;
341		}
342
343		if (cmp < 0)
344			p = &(*p)->rb_left;
345		else
346			p = &(*p)->rb_right;
347	}
348
349	rb_link_node(&bss->rbn, parent, p);
350	rb_insert_color(&bss->rbn, &dev->bss_tree);
351}
352
353static struct cfg80211_internal_bss *
354rb_find_bss(struct cfg80211_registered_device *dev,
355	    struct cfg80211_internal_bss *res)
356{
357	struct rb_node *n = dev->bss_tree.rb_node;
358	struct cfg80211_internal_bss *bss;
359	int r;
360
361	while (n) {
362		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
363		r = cmp_bss(&res->pub, &bss->pub);
364
365		if (r == 0)
366			return bss;
367		else if (r < 0)
368			n = n->rb_left;
369		else
370			n = n->rb_right;
371	}
372
373	return NULL;
374}
375
376static struct cfg80211_internal_bss *
377cfg80211_bss_update(struct cfg80211_registered_device *dev,
378		    struct cfg80211_internal_bss *res,
379		    bool overwrite)
380{
381	struct cfg80211_internal_bss *found = NULL;
382	const u8 *meshid, *meshcfg;
383
384	/*
385	 * The reference to "res" is donated to this function.
386	 */
387
388	if (WARN_ON(!res->pub.channel)) {
389		kref_put(&res->ref, bss_release);
390		return NULL;
391	}
392
393	res->ts = jiffies;
394
395	if (is_zero_ether_addr(res->pub.bssid)) {
396		/* must be mesh, verify */
397		meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
398				 res->pub.len_information_elements);
399		meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
400				  res->pub.information_elements,
401				  res->pub.len_information_elements);
402		if (!meshid || !meshcfg ||
403		    meshcfg[1] != sizeof(struct ieee80211_meshconf_ie)) {
404			/* bogus mesh */
405			kref_put(&res->ref, bss_release);
406			return NULL;
407		}
408	}
409
410	spin_lock_bh(&dev->bss_lock);
411
412	found = rb_find_bss(dev, res);
413
414	if (found) {
415		found->pub.beacon_interval = res->pub.beacon_interval;
416		found->pub.tsf = res->pub.tsf;
417		found->pub.signal = res->pub.signal;
418		found->pub.capability = res->pub.capability;
419		found->ts = res->ts;
420
421		/* overwrite IEs */
422		if (overwrite) {
423			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
424			size_t ielen = res->pub.len_information_elements;
425
426			if (!found->ies_allocated && ksize(found) >= used + ielen) {
427				memcpy(found->pub.information_elements,
428				       res->pub.information_elements, ielen);
429				found->pub.len_information_elements = ielen;
430			} else {
431				u8 *ies = found->pub.information_elements;
432
433				if (found->ies_allocated)
434					ies = krealloc(ies, ielen, GFP_ATOMIC);
435				else
436					ies = kmalloc(ielen, GFP_ATOMIC);
437
438				if (ies) {
439					memcpy(ies, res->pub.information_elements, ielen);
440					found->ies_allocated = true;
441					found->pub.information_elements = ies;
442					found->pub.len_information_elements = ielen;
443				}
444			}
445		}
446
447		kref_put(&res->ref, bss_release);
448	} else {
449		/* this "consumes" the reference */
450		list_add_tail(&res->list, &dev->bss_list);
451		rb_insert_bss(dev, res);
452		found = res;
453	}
454
455	dev->bss_generation++;
456	spin_unlock_bh(&dev->bss_lock);
457
458	kref_get(&found->ref);
459	return found;
460}
461
462struct cfg80211_bss*
463cfg80211_inform_bss(struct wiphy *wiphy,
464		    struct ieee80211_channel *channel,
465		    const u8 *bssid,
466		    u64 timestamp, u16 capability, u16 beacon_interval,
467		    const u8 *ie, size_t ielen,
468		    s32 signal, gfp_t gfp)
469{
470	struct cfg80211_internal_bss *res;
471	size_t privsz;
472
473	if (WARN_ON(!wiphy))
474		return NULL;
475
476	privsz = wiphy->bss_priv_size;
477
478	if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
479			(signal < 0 || signal > 100)))
480		return NULL;
481
482	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
483	if (!res)
484		return NULL;
485
486	memcpy(res->pub.bssid, bssid, ETH_ALEN);
487	res->pub.channel = channel;
488	res->pub.signal = signal;
489	res->pub.tsf = timestamp;
490	res->pub.beacon_interval = beacon_interval;
491	res->pub.capability = capability;
492	/* point to after the private area */
493	res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
494	memcpy(res->pub.information_elements, ie, ielen);
495	res->pub.len_information_elements = ielen;
496
497	kref_init(&res->ref);
498
499	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
500	if (!res)
501		return NULL;
502
503	if (res->pub.capability & WLAN_CAPABILITY_ESS)
504		regulatory_hint_found_beacon(wiphy, channel, gfp);
505
506	/* cfg80211_bss_update gives us a referenced result */
507	return &res->pub;
508}
509EXPORT_SYMBOL(cfg80211_inform_bss);
510
511struct cfg80211_bss *
512cfg80211_inform_bss_frame(struct wiphy *wiphy,
513			  struct ieee80211_channel *channel,
514			  struct ieee80211_mgmt *mgmt, size_t len,
515			  s32 signal, gfp_t gfp)
516{
517	struct cfg80211_internal_bss *res;
518	size_t ielen = len - offsetof(struct ieee80211_mgmt,
519				      u.probe_resp.variable);
520	bool overwrite;
521	size_t privsz = wiphy->bss_priv_size;
522
523	if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
524	            (signal < 0 || signal > 100)))
525		return NULL;
526
527	if (WARN_ON(!mgmt || !wiphy ||
528		    len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
529		return NULL;
530
531	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
532	if (!res)
533		return NULL;
534
535	memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
536	res->pub.channel = channel;
537	res->pub.signal = signal;
538	res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
539	res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
540	res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
541	/* point to after the private area */
542	res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
543	memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
544	res->pub.len_information_elements = ielen;
545
546	kref_init(&res->ref);
547
548	overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
549
550	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
551	if (!res)
552		return NULL;
553
554	if (res->pub.capability & WLAN_CAPABILITY_ESS)
555		regulatory_hint_found_beacon(wiphy, channel, gfp);
556
557	/* cfg80211_bss_update gives us a referenced result */
558	return &res->pub;
559}
560EXPORT_SYMBOL(cfg80211_inform_bss_frame);
561
562void cfg80211_put_bss(struct cfg80211_bss *pub)
563{
564	struct cfg80211_internal_bss *bss;
565
566	if (!pub)
567		return;
568
569	bss = container_of(pub, struct cfg80211_internal_bss, pub);
570	kref_put(&bss->ref, bss_release);
571}
572EXPORT_SYMBOL(cfg80211_put_bss);
573
574void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
575{
576	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
577	struct cfg80211_internal_bss *bss;
578
579	if (WARN_ON(!pub))
580		return;
581
582	bss = container_of(pub, struct cfg80211_internal_bss, pub);
583
584	spin_lock_bh(&dev->bss_lock);
585
586	list_del(&bss->list);
587	dev->bss_generation++;
588	rb_erase(&bss->rbn, &dev->bss_tree);
589
590	spin_unlock_bh(&dev->bss_lock);
591
592	kref_put(&bss->ref, bss_release);
593}
594EXPORT_SYMBOL(cfg80211_unlink_bss);
595
596#ifdef CONFIG_CFG80211_WEXT
597int cfg80211_wext_siwscan(struct net_device *dev,
598			  struct iw_request_info *info,
599			  union iwreq_data *wrqu, char *extra)
600{
601	struct cfg80211_registered_device *rdev;
602	struct wiphy *wiphy;
603	struct iw_scan_req *wreq = NULL;
604	struct cfg80211_scan_request *creq;
605	int i, err, n_channels = 0;
606	enum ieee80211_band band;
607
608	if (!netif_running(dev))
609		return -ENETDOWN;
610
611	if (wrqu->data.length == sizeof(struct iw_scan_req))
612		wreq = (struct iw_scan_req *)extra;
613
614	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
615
616	if (IS_ERR(rdev))
617		return PTR_ERR(rdev);
618
619	if (rdev->scan_req) {
620		err = -EBUSY;
621		goto out;
622	}
623
624	wiphy = &rdev->wiphy;
625
626	/* Determine number of channels, needed to allocate creq */
627	if (wreq && wreq->num_channels)
628		n_channels = wreq->num_channels;
629	else {
630		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
631			if (wiphy->bands[band])
632				n_channels += wiphy->bands[band]->n_channels;
633	}
634
635	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
636		       n_channels * sizeof(void *),
637		       GFP_ATOMIC);
638	if (!creq) {
639		err = -ENOMEM;
640		goto out;
641	}
642
643	creq->wiphy = wiphy;
644	creq->dev = dev;
645	/* SSIDs come after channels */
646	creq->ssids = (void *)&creq->channels[n_channels];
647	creq->n_channels = n_channels;
648	creq->n_ssids = 1;
649
650	/* translate "Scan on frequencies" request */
651	i = 0;
652	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
653		int j;
654
655		if (!wiphy->bands[band])
656			continue;
657
658		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
659			/* ignore disabled channels */
660			if (wiphy->bands[band]->channels[j].flags &
661						IEEE80211_CHAN_DISABLED)
662				continue;
663
664			/* If we have a wireless request structure and the
665			 * wireless request specifies frequencies, then search
666			 * for the matching hardware channel.
667			 */
668			if (wreq && wreq->num_channels) {
669				int k;
670				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
671				for (k = 0; k < wreq->num_channels; k++) {
672					int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
673					if (wext_freq == wiphy_freq)
674						goto wext_freq_found;
675				}
676				goto wext_freq_not_found;
677			}
678
679		wext_freq_found:
680			creq->channels[i] = &wiphy->bands[band]->channels[j];
681			i++;
682		wext_freq_not_found: ;
683		}
684	}
685	/* No channels found? */
686	if (!i) {
687		err = -EINVAL;
688		goto out;
689	}
690
691	/* Set real number of channels specified in creq->channels[] */
692	creq->n_channels = i;
693
694	/* translate "Scan for SSID" request */
695	if (wreq) {
696		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
697			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
698				return -EINVAL;
699			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
700			creq->ssids[0].ssid_len = wreq->essid_len;
701		}
702		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
703			creq->n_ssids = 0;
704	}
705
706	rdev->scan_req = creq;
707	err = rdev->ops->scan(wiphy, dev, creq);
708	if (err) {
709		rdev->scan_req = NULL;
710		kfree(creq);
711	} else {
712		nl80211_send_scan_start(rdev, dev);
713		dev_hold(dev);
714	}
715 out:
716	cfg80211_unlock_rdev(rdev);
717	return err;
718}
719EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
720
721static void ieee80211_scan_add_ies(struct iw_request_info *info,
722				   struct cfg80211_bss *bss,
723				   char **current_ev, char *end_buf)
724{
725	u8 *pos, *end, *next;
726	struct iw_event iwe;
727
728	if (!bss->information_elements ||
729	    !bss->len_information_elements)
730		return;
731
732	/*
733	 * If needed, fragment the IEs buffer (at IE boundaries) into short
734	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
735	 */
736	pos = bss->information_elements;
737	end = pos + bss->len_information_elements;
738
739	while (end - pos > IW_GENERIC_IE_MAX) {
740		next = pos + 2 + pos[1];
741		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
742			next = next + 2 + next[1];
743
744		memset(&iwe, 0, sizeof(iwe));
745		iwe.cmd = IWEVGENIE;
746		iwe.u.data.length = next - pos;
747		*current_ev = iwe_stream_add_point(info, *current_ev,
748						   end_buf, &iwe, pos);
749
750		pos = next;
751	}
752
753	if (end > pos) {
754		memset(&iwe, 0, sizeof(iwe));
755		iwe.cmd = IWEVGENIE;
756		iwe.u.data.length = end - pos;
757		*current_ev = iwe_stream_add_point(info, *current_ev,
758						   end_buf, &iwe, pos);
759	}
760}
761
762static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
763{
764	unsigned long end = jiffies;
765
766	if (end >= start)
767		return jiffies_to_msecs(end - start);
768
769	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
770}
771
772static char *
773ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
774	      struct cfg80211_internal_bss *bss, char *current_ev,
775	      char *end_buf)
776{
777	struct iw_event iwe;
778	u8 *buf, *cfg, *p;
779	u8 *ie = bss->pub.information_elements;
780	int rem = bss->pub.len_information_elements, i, sig;
781	bool ismesh = false;
782
783	memset(&iwe, 0, sizeof(iwe));
784	iwe.cmd = SIOCGIWAP;
785	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
786	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
787	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
788					  IW_EV_ADDR_LEN);
789
790	memset(&iwe, 0, sizeof(iwe));
791	iwe.cmd = SIOCGIWFREQ;
792	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
793	iwe.u.freq.e = 0;
794	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
795					  IW_EV_FREQ_LEN);
796
797	memset(&iwe, 0, sizeof(iwe));
798	iwe.cmd = SIOCGIWFREQ;
799	iwe.u.freq.m = bss->pub.channel->center_freq;
800	iwe.u.freq.e = 6;
801	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
802					  IW_EV_FREQ_LEN);
803
804	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
805		memset(&iwe, 0, sizeof(iwe));
806		iwe.cmd = IWEVQUAL;
807		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
808				     IW_QUAL_NOISE_INVALID |
809				     IW_QUAL_QUAL_UPDATED;
810		switch (wiphy->signal_type) {
811		case CFG80211_SIGNAL_TYPE_MBM:
812			sig = bss->pub.signal / 100;
813			iwe.u.qual.level = sig;
814			iwe.u.qual.updated |= IW_QUAL_DBM;
815			if (sig < -110)		/* rather bad */
816				sig = -110;
817			else if (sig > -40)	/* perfect */
818				sig = -40;
819			/* will give a range of 0 .. 70 */
820			iwe.u.qual.qual = sig + 110;
821			break;
822		case CFG80211_SIGNAL_TYPE_UNSPEC:
823			iwe.u.qual.level = bss->pub.signal;
824			/* will give range 0 .. 100 */
825			iwe.u.qual.qual = bss->pub.signal;
826			break;
827		default:
828			/* not reached */
829			break;
830		}
831		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
832						  &iwe, IW_EV_QUAL_LEN);
833	}
834
835	memset(&iwe, 0, sizeof(iwe));
836	iwe.cmd = SIOCGIWENCODE;
837	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
838		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
839	else
840		iwe.u.data.flags = IW_ENCODE_DISABLED;
841	iwe.u.data.length = 0;
842	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
843					  &iwe, "");
844
845	while (rem >= 2) {
846		/* invalid data */
847		if (ie[1] > rem - 2)
848			break;
849
850		switch (ie[0]) {
851		case WLAN_EID_SSID:
852			memset(&iwe, 0, sizeof(iwe));
853			iwe.cmd = SIOCGIWESSID;
854			iwe.u.data.length = ie[1];
855			iwe.u.data.flags = 1;
856			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
857							  &iwe, ie + 2);
858			break;
859		case WLAN_EID_MESH_ID:
860			memset(&iwe, 0, sizeof(iwe));
861			iwe.cmd = SIOCGIWESSID;
862			iwe.u.data.length = ie[1];
863			iwe.u.data.flags = 1;
864			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
865							  &iwe, ie + 2);
866			break;
867		case WLAN_EID_MESH_CONFIG:
868			ismesh = true;
869			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
870				break;
871			buf = kmalloc(50, GFP_ATOMIC);
872			if (!buf)
873				break;
874			cfg = ie + 2;
875			memset(&iwe, 0, sizeof(iwe));
876			iwe.cmd = IWEVCUSTOM;
877			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
878				"0x%02X", cfg[0]);
879			iwe.u.data.length = strlen(buf);
880			current_ev = iwe_stream_add_point(info, current_ev,
881							  end_buf,
882							  &iwe, buf);
883			sprintf(buf, "Path Selection Metric ID: 0x%02X",
884				cfg[1]);
885			iwe.u.data.length = strlen(buf);
886			current_ev = iwe_stream_add_point(info, current_ev,
887							  end_buf,
888							  &iwe, buf);
889			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
890				cfg[2]);
891			iwe.u.data.length = strlen(buf);
892			current_ev = iwe_stream_add_point(info, current_ev,
893							  end_buf,
894							  &iwe, buf);
895			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
896			iwe.u.data.length = strlen(buf);
897			current_ev = iwe_stream_add_point(info, current_ev,
898							  end_buf,
899							  &iwe, buf);
900			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
901			iwe.u.data.length = strlen(buf);
902			current_ev = iwe_stream_add_point(info, current_ev,
903							  end_buf,
904							  &iwe, buf);
905			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
906			iwe.u.data.length = strlen(buf);
907			current_ev = iwe_stream_add_point(info, current_ev,
908							  end_buf,
909							  &iwe, buf);
910			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
911			iwe.u.data.length = strlen(buf);
912			current_ev = iwe_stream_add_point(info, current_ev,
913							  end_buf,
914							  &iwe, buf);
915			kfree(buf);
916			break;
917		case WLAN_EID_SUPP_RATES:
918		case WLAN_EID_EXT_SUPP_RATES:
919			/* display all supported rates in readable format */
920			p = current_ev + iwe_stream_lcp_len(info);
921
922			memset(&iwe, 0, sizeof(iwe));
923			iwe.cmd = SIOCGIWRATE;
924			/* Those two flags are ignored... */
925			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
926
927			for (i = 0; i < ie[1]; i++) {
928				iwe.u.bitrate.value =
929					((ie[i + 2] & 0x7f) * 500000);
930				p = iwe_stream_add_value(info, current_ev, p,
931						end_buf, &iwe, IW_EV_PARAM_LEN);
932			}
933			current_ev = p;
934			break;
935		}
936		rem -= ie[1] + 2;
937		ie += ie[1] + 2;
938	}
939
940	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
941	    || ismesh) {
942		memset(&iwe, 0, sizeof(iwe));
943		iwe.cmd = SIOCGIWMODE;
944		if (ismesh)
945			iwe.u.mode = IW_MODE_MESH;
946		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
947			iwe.u.mode = IW_MODE_MASTER;
948		else
949			iwe.u.mode = IW_MODE_ADHOC;
950		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
951						  &iwe, IW_EV_UINT_LEN);
952	}
953
954	buf = kmalloc(30, GFP_ATOMIC);
955	if (buf) {
956		memset(&iwe, 0, sizeof(iwe));
957		iwe.cmd = IWEVCUSTOM;
958		sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
959		iwe.u.data.length = strlen(buf);
960		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
961						  &iwe, buf);
962		memset(&iwe, 0, sizeof(iwe));
963		iwe.cmd = IWEVCUSTOM;
964		sprintf(buf, " Last beacon: %ums ago",
965			elapsed_jiffies_msecs(bss->ts));
966		iwe.u.data.length = strlen(buf);
967		current_ev = iwe_stream_add_point(info, current_ev,
968						  end_buf, &iwe, buf);
969		kfree(buf);
970	}
971
972	ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
973
974	return current_ev;
975}
976
977
978static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
979				  struct iw_request_info *info,
980				  char *buf, size_t len)
981{
982	char *current_ev = buf;
983	char *end_buf = buf + len;
984	struct cfg80211_internal_bss *bss;
985
986	spin_lock_bh(&dev->bss_lock);
987	cfg80211_bss_expire(dev);
988
989	list_for_each_entry(bss, &dev->bss_list, list) {
990		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
991			spin_unlock_bh(&dev->bss_lock);
992			return -E2BIG;
993		}
994		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
995					   current_ev, end_buf);
996	}
997	spin_unlock_bh(&dev->bss_lock);
998	return current_ev - buf;
999}
1000
1001
1002int cfg80211_wext_giwscan(struct net_device *dev,
1003			  struct iw_request_info *info,
1004			  struct iw_point *data, char *extra)
1005{
1006	struct cfg80211_registered_device *rdev;
1007	int res;
1008
1009	if (!netif_running(dev))
1010		return -ENETDOWN;
1011
1012	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1013
1014	if (IS_ERR(rdev))
1015		return PTR_ERR(rdev);
1016
1017	if (rdev->scan_req) {
1018		res = -EAGAIN;
1019		goto out;
1020	}
1021
1022	res = ieee80211_scan_results(rdev, info, extra, data->length);
1023	data->length = 0;
1024	if (res >= 0) {
1025		data->length = res;
1026		res = 0;
1027	}
1028
1029 out:
1030	cfg80211_unlock_rdev(rdev);
1031	return res;
1032}
1033EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1034#endif
1035