Initial import

1 files changed, 1679 insertions, 0 deletions

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
new file mode 100644
index 000000000..3a50aa255
--- /dev/null
+++ b/net/wireless/scan.c
@@ -0,0 +1,1679 @@
+/*
+ * cfg80211 scan result handling
+ *
+ * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2013-2014  Intel Mobile Communications GmbH
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/wireless.h>
+#include <linux/nl80211.h>
+#include <linux/etherdevice.h>
+#include <net/arp.h>
+#include <net/cfg80211.h>
+#include <net/cfg80211-wext.h>
+#include <net/iw_handler.h>
+#include "core.h"
+#include "nl80211.h"
+#include "wext-compat.h"
+#include "rdev-ops.h"
+
+/**
+ * DOC: BSS tree/list structure
+ *
+ * At the top level, the BSS list is kept in both a list in each
+ * registered device (@bss_list) as well as an RB-tree for faster
+ * lookup. In the RB-tree, entries can be looked up using their
+ * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
+ * for other BSSes.
+ *
+ * Due to the possibility of hidden SSIDs, there's a second level
+ * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
+ * The hidden_list connects all BSSes belonging to a single AP
+ * that has a hidden SSID, and connects beacon and probe response
+ * entries. For a probe response entry for a hidden SSID, the
+ * hidden_beacon_bss pointer points to the BSS struct holding the
+ * beacon's information.
+ *
+ * Reference counting is done for all these references except for
+ * the hidden_list, so that a beacon BSS struct that is otherwise
+ * not referenced has one reference for being on the bss_list and
+ * one for each probe response entry that points to it using the
+ * hidden_beacon_bss pointer. When a BSS struct that has such a
+ * pointer is get/put, the refcount update is also propagated to
+ * the referenced struct, this ensure that it cannot get removed
+ * while somebody is using the probe response version.
+ *
+ * Note that the hidden_beacon_bss pointer never changes, due to
+ * the reference counting. Therefore, no locking is needed for
+ * it.
+ *
+ * Also note that the hidden_beacon_bss pointer is only relevant
+ * if the driver uses something other than the IEs, e.g. private
+ * data stored stored in the BSS struct, since the beacon IEs are
+ * also linked into the probe response struct.
+ */
+
+#define IEEE80211_SCAN_RESULT_EXPIRE	(30 * HZ)
+
+static void bss_free(struct cfg80211_internal_bss *bss)
+{
+	struct cfg80211_bss_ies *ies;
+
+	if (WARN_ON(atomic_read(&bss->hold)))
+		return;
+
+	ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
+	if (ies && !bss->pub.hidden_beacon_bss)
+		kfree_rcu(ies, rcu_head);
+	ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
+	if (ies)
+		kfree_rcu(ies, rcu_head);
+
+	/*
+	 * This happens when the module is removed, it doesn't
+	 * really matter any more save for completeness
+	 */
+	if (!list_empty(&bss->hidden_list))
+		list_del(&bss->hidden_list);
+
+	kfree(bss);
+}
+
+static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
+			       struct cfg80211_internal_bss *bss)
+{
+	lockdep_assert_held(&rdev->bss_lock);
+
+	bss->refcount++;
+	if (bss->pub.hidden_beacon_bss) {
+		bss = container_of(bss->pub.hidden_beacon_bss,
+				   struct cfg80211_internal_bss,
+				   pub);
+		bss->refcount++;
+	}
+}
+
+static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
+			       struct cfg80211_internal_bss *bss)
+{
+	lockdep_assert_held(&rdev->bss_lock);
+
+	if (bss->pub.hidden_beacon_bss) {
+		struct cfg80211_internal_bss *hbss;
+		hbss = container_of(bss->pub.hidden_beacon_bss,
+				    struct cfg80211_internal_bss,
+				    pub);
+		hbss->refcount--;
+		if (hbss->refcount == 0)
+			bss_free(hbss);
+	}
+	bss->refcount--;
+	if (bss->refcount == 0)
+		bss_free(bss);
+}
+
+static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev,
+				  struct cfg80211_internal_bss *bss)
+{
+	lockdep_assert_held(&rdev->bss_lock);
+
+	if (!list_empty(&bss->hidden_list)) {
+		/*
+		 * don't remove the beacon entry if it has
+		 * probe responses associated with it
+		 */
+		if (!bss->pub.hidden_beacon_bss)
+			return false;
+		/*
+		 * if it's a probe response entry break its
+		 * link to the other entries in the group
+		 */
+		list_del_init(&bss->hidden_list);
+	}
+
+	list_del_init(&bss->list);
+	rb_erase(&bss->rbn, &rdev->bss_tree);
+	bss_ref_put(rdev, bss);
+	return true;
+}
+
+static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev,
+				  unsigned long expire_time)
+{
+	struct cfg80211_internal_bss *bss, *tmp;
+	bool expired = false;
+
+	lockdep_assert_held(&rdev->bss_lock);
+
+	list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) {
+		if (atomic_read(&bss->hold))
+			continue;
+		if (!time_after(expire_time, bss->ts))
+			continue;
+
+		if (__cfg80211_unlink_bss(rdev, bss))
+			expired = true;
+	}
+
+	if (expired)
+		rdev->bss_generation++;
+}
+
+void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
+			   bool send_message)
+{
+	struct cfg80211_scan_request *request;
+	struct wireless_dev *wdev;
+	struct sk_buff *msg;
+#ifdef CONFIG_CFG80211_WEXT
+	union iwreq_data wrqu;
+#endif
+
+	ASSERT_RTNL();
+
+	if (rdev->scan_msg) {
+		nl80211_send_scan_result(rdev, rdev->scan_msg);
+		rdev->scan_msg = NULL;
+		return;
+	}
+
+	request = rdev->scan_req;
+	if (!request)
+		return;
+
+	wdev = request->wdev;
+
+	/*
+	 * This must be before sending the other events!
+	 * Otherwise, wpa_supplicant gets completely confused with
+	 * wext events.
+	 */
+	if (wdev->netdev)
+		cfg80211_sme_scan_done(wdev->netdev);
+
+	if (!request->aborted &&
+	    request->flags & NL80211_SCAN_FLAG_FLUSH) {
+		/* flush entries from previous scans */
+		spin_lock_bh(&rdev->bss_lock);
+		__cfg80211_bss_expire(rdev, request->scan_start);
+		spin_unlock_bh(&rdev->bss_lock);
+	}
+
+	msg = nl80211_build_scan_msg(rdev, wdev, request->aborted);
+
+#ifdef CONFIG_CFG80211_WEXT
+	if (wdev->netdev && !request->aborted) {
+		memset(&wrqu, 0, sizeof(wrqu));
+
+		wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
+	}
+#endif
+
+	if (wdev->netdev)
+		dev_put(wdev->netdev);
+
+	rdev->scan_req = NULL;
+	kfree(request);
+
+	if (!send_message)
+		rdev->scan_msg = msg;
+	else
+		nl80211_send_scan_result(rdev, msg);
+}
+
+void __cfg80211_scan_done(struct work_struct *wk)
+{
+	struct cfg80211_registered_device *rdev;
+
+	rdev = container_of(wk, struct cfg80211_registered_device,
+			    scan_done_wk);
+
+	rtnl_lock();
+	___cfg80211_scan_done(rdev, true);
+	rtnl_unlock();
+}
+
+void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
+{
+	trace_cfg80211_scan_done(request, aborted);
+	WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req);
+
+	request->aborted = aborted;
+	request->notified = true;
+	queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk);
+}
+EXPORT_SYMBOL(cfg80211_scan_done);
+
+void __cfg80211_sched_scan_results(struct work_struct *wk)
+{
+	struct cfg80211_registered_device *rdev;
+	struct cfg80211_sched_scan_request *request;
+
+	rdev = container_of(wk, struct cfg80211_registered_device,
+			    sched_scan_results_wk);
+
+	rtnl_lock();
+
+	request = rtnl_dereference(rdev->sched_scan_req);
+
+	/* we don't have sched_scan_req anymore if the scan is stopping */
+	if (request) {
+		if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
+			/* flush entries from previous scans */
+			spin_lock_bh(&rdev->bss_lock);
+			__cfg80211_bss_expire(rdev, request->scan_start);
+			spin_unlock_bh(&rdev->bss_lock);
+			request->scan_start =
+				jiffies + msecs_to_jiffies(request->interval);
+		}
+		nl80211_send_sched_scan_results(rdev, request->dev);
+	}
+
+	rtnl_unlock();
+}
+
+void cfg80211_sched_scan_results(struct wiphy *wiphy)
+{
+	trace_cfg80211_sched_scan_results(wiphy);
+	/* ignore if we're not scanning */
+
+	if (rcu_access_pointer(wiphy_to_rdev(wiphy)->sched_scan_req))
+		queue_work(cfg80211_wq,
+			   &wiphy_to_rdev(wiphy)->sched_scan_results_wk);
+}
+EXPORT_SYMBOL(cfg80211_sched_scan_results);
+
+void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy)
+{
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+
+	ASSERT_RTNL();
+
+	trace_cfg80211_sched_scan_stopped(wiphy);
+
+	__cfg80211_stop_sched_scan(rdev, true);
+}
+EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl);
+
+void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
+{
+	rtnl_lock();
+	cfg80211_sched_scan_stopped_rtnl(wiphy);
+	rtnl_unlock();
+}
+EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
+
+int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
+			       bool driver_initiated)
+{
+	struct cfg80211_sched_scan_request *sched_scan_req;
+	struct net_device *dev;
+
+	ASSERT_RTNL();
+
+	if (!rdev->sched_scan_req)
+		return -ENOENT;
+
+	sched_scan_req = rtnl_dereference(rdev->sched_scan_req);
+	dev = sched_scan_req->dev;
+
+	if (!driver_initiated) {
+		int err = rdev_sched_scan_stop(rdev, dev);
+		if (err)
+			return err;
+	}
+
+	nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
+
+	RCU_INIT_POINTER(rdev->sched_scan_req, NULL);
+	kfree_rcu(sched_scan_req, rcu_head);
+
+	return 0;
+}
+
+void cfg80211_bss_age(struct cfg80211_registered_device *rdev,
+                      unsigned long age_secs)
+{
+	struct cfg80211_internal_bss *bss;
+	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
+
+	spin_lock_bh(&rdev->bss_lock);
+	list_for_each_entry(bss, &rdev->bss_list, list)
+		bss->ts -= age_jiffies;
+	spin_unlock_bh(&rdev->bss_lock);
+}
+
+void cfg80211_bss_expire(struct cfg80211_registered_device *rdev)
+{
+	__cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
+}
+
+const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
+{
+	while (len > 2 && ies[0] != eid) {
+		len -= ies[1] + 2;
+		ies += ies[1] + 2;
+	}
+	if (len < 2)
+		return NULL;
+	if (len < 2 + ies[1])
+		return NULL;
+	return ies;
+}
+EXPORT_SYMBOL(cfg80211_find_ie);
+
+const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
+				  const u8 *ies, int len)
+{
+	struct ieee80211_vendor_ie *ie;
+	const u8 *pos = ies, *end = ies + len;
+	int ie_oui;
+
+	while (pos < end) {
+		pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
+				       end - pos);
+		if (!pos)
+			return NULL;
+
+		ie = (struct ieee80211_vendor_ie *)pos;
+
+		/* make sure we can access ie->len */
+		BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
+
+		if (ie->len < sizeof(*ie))
+			goto cont;
+
+		ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
+		if (ie_oui == oui && ie->oui_type == oui_type)
+			return pos;
+cont:
+		pos += 2 + ie->len;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(cfg80211_find_vendor_ie);
+
+static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
+		   const u8 *ssid, size_t ssid_len)
+{
+	const struct cfg80211_bss_ies *ies;
+	const u8 *ssidie;
+
+	if (bssid && !ether_addr_equal(a->bssid, bssid))
+		return false;
+
+	if (!ssid)
+		return true;
+
+	ies = rcu_access_pointer(a->ies);
+	if (!ies)
+		return false;
+	ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
+	if (!ssidie)
+		return false;
+	if (ssidie[1] != ssid_len)
+		return false;
+	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
+}
+
+/**
+ * enum bss_compare_mode - BSS compare mode
+ * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
+ * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
+ * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
+ */
+enum bss_compare_mode {
+	BSS_CMP_REGULAR,
+	BSS_CMP_HIDE_ZLEN,
+	BSS_CMP_HIDE_NUL,
+};
+
+static int cmp_bss(struct cfg80211_bss *a,
+		   struct cfg80211_bss *b,
+		   enum bss_compare_mode mode)
+{
+	const struct cfg80211_bss_ies *a_ies, *b_ies;
+	const u8 *ie1 = NULL;
+	const u8 *ie2 = NULL;
+	int i, r;
+
+	if (a->channel != b->channel)
+		return b->channel->center_freq - a->channel->center_freq;
+
+	a_ies = rcu_access_pointer(a->ies);
+	if (!a_ies)
+		return -1;
+	b_ies = rcu_access_pointer(b->ies);
+	if (!b_ies)
+		return 1;
+
+	if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
+		ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
+				       a_ies->data, a_ies->len);
+	if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
+		ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
+				       b_ies->data, b_ies->len);
+	if (ie1 && ie2) {
+		int mesh_id_cmp;
+
+		if (ie1[1] == ie2[1])
+			mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
+		else
+			mesh_id_cmp = ie2[1] - ie1[1];
+
+		ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
+				       a_ies->data, a_ies->len);
+		ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
+				       b_ies->data, b_ies->len);
+		if (ie1 && ie2) {
+			if (mesh_id_cmp)
+				return mesh_id_cmp;
+			if (ie1[1] != ie2[1])
+				return ie2[1] - ie1[1];
+			return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
+		}
+	}
+
+	r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
+	if (r)
+		return r;
+
+	ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
+	ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
+
+	if (!ie1 && !ie2)
+		return 0;
+
+	/*
+	 * Note that with "hide_ssid", the function returns a match if
+	 * the already-present BSS ("b") is a hidden SSID beacon for
+	 * the new BSS ("a").
+	 */
+
+	/* sort missing IE before (left of) present IE */
+	if (!ie1)
+		return -1;
+	if (!ie2)
+		return 1;
+
+	switch (mode) {
+	case BSS_CMP_HIDE_ZLEN:
+		/*
+		 * In ZLEN mode we assume the BSS entry we're
+		 * looking for has a zero-length SSID. So if
+		 * the one we're looking at right now has that,
+		 * return 0. Otherwise, return the difference
+		 * in length, but since we're looking for the
+		 * 0-length it's really equivalent to returning
+		 * the length of the one we're looking at.
+		 *
+		 * No content comparison is needed as we assume
+		 * the content length is zero.
+		 */
+		return ie2[1];
+	case BSS_CMP_REGULAR:
+	default:
+		/* sort by length first, then by contents */
+		if (ie1[1] != ie2[1])
+			return ie2[1] - ie1[1];
+		return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
+	case BSS_CMP_HIDE_NUL:
+		if (ie1[1] != ie2[1])
+			return ie2[1] - ie1[1];
+		/* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
+		for (i = 0; i < ie2[1]; i++)
+			if (ie2[i + 2])
+				return -1;
+		return 0;
+	}
+}
+
+static bool cfg80211_bss_type_match(u16 capability,
+				    enum ieee80211_band band,
+				    enum ieee80211_bss_type bss_type)
+{
+	bool ret = true;
+	u16 mask, val;
+
+	if (bss_type == IEEE80211_BSS_TYPE_ANY)
+		return ret;
+
+	if (band == IEEE80211_BAND_60GHZ) {
+		mask = WLAN_CAPABILITY_DMG_TYPE_MASK;
+		switch (bss_type) {
+		case IEEE80211_BSS_TYPE_ESS:
+			val = WLAN_CAPABILITY_DMG_TYPE_AP;
+			break;
+		case IEEE80211_BSS_TYPE_PBSS:
+			val = WLAN_CAPABILITY_DMG_TYPE_PBSS;
+			break;
+		case IEEE80211_BSS_TYPE_IBSS:
+			val = WLAN_CAPABILITY_DMG_TYPE_IBSS;
+			break;
+		default:
+			return false;
+		}
+	} else {
+		mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS;
+		switch (bss_type) {
+		case IEEE80211_BSS_TYPE_ESS:
+			val = WLAN_CAPABILITY_ESS;
+			break;
+		case IEEE80211_BSS_TYPE_IBSS:
+			val = WLAN_CAPABILITY_IBSS;
+			break;
+		case IEEE80211_BSS_TYPE_MBSS:
+			val = 0;
+			break;
+		default:
+			return false;
+		}
+	}
+
+	ret = ((capability & mask) == val);
+	return ret;
+}
+
+/* Returned bss is reference counted and must be cleaned up appropriately. */
+struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
+				      struct ieee80211_channel *channel,
+				      const u8 *bssid,
+				      const u8 *ssid, size_t ssid_len,
+				      enum ieee80211_bss_type bss_type,
+				      enum ieee80211_privacy privacy)
+{
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+	struct cfg80211_internal_bss *bss, *res = NULL;
+	unsigned long now = jiffies;
+	int bss_privacy;
+
+	trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type,
+			       privacy);
+
+	spin_lock_bh(&rdev->bss_lock);
+
+	list_for_each_entry(bss, &rdev->bss_list, list) {
+		if (!cfg80211_bss_type_match(bss->pub.capability,
+					     bss->pub.channel->band, bss_type))
+			continue;
+
+		bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY);
+		if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) ||
+		    (privacy == IEEE80211_PRIVACY_OFF && bss_privacy))
+			continue;
+		if (channel && bss->pub.channel != channel)
+			continue;
+		if (!is_valid_ether_addr(bss->pub.bssid))
+			continue;
+		/* Don't get expired BSS structs */
+		if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
+		    !atomic_read(&bss->hold))
+			continue;
+		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
+			res = bss;
+			bss_ref_get(rdev, res);
+			break;
+		}
+	}
+
+	spin_unlock_bh(&rdev->bss_lock);
+	if (!res)
+		return NULL;
+	trace_cfg80211_return_bss(&res->pub);
+	return &res->pub;
+}
+EXPORT_SYMBOL(cfg80211_get_bss);
+
+static void rb_insert_bss(struct cfg80211_registered_device *rdev,
+			  struct cfg80211_internal_bss *bss)
+{
+	struct rb_node **p = &rdev->bss_tree.rb_node;
+	struct rb_node *parent = NULL;
+	struct cfg80211_internal_bss *tbss;
+	int cmp;
+
+	while (*p) {
+		parent = *p;
+		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
+
+		cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
+
+		if (WARN_ON(!cmp)) {
+			/* will sort of leak this BSS */
+			return;
+		}
+
+		if (cmp < 0)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+
+	rb_link_node(&bss->rbn, parent, p);
+	rb_insert_color(&bss->rbn, &rdev->bss_tree);
+}
+
+static struct cfg80211_internal_bss *
+rb_find_bss(struct cfg80211_registered_device *rdev,
+	    struct cfg80211_internal_bss *res,
+	    enum bss_compare_mode mode)
+{
+	struct rb_node *n = rdev->bss_tree.rb_node;
+	struct cfg80211_internal_bss *bss;
+	int r;
+
+	while (n) {
+		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
+		r = cmp_bss(&res->pub, &bss->pub, mode);
+
+		if (r == 0)
+			return bss;
+		else if (r < 0)
+			n = n->rb_left;
+		else
+			n = n->rb_right;
+	}
+
+	return NULL;
+}
+
+static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev,
+				   struct cfg80211_internal_bss *new)
+{
+	const struct cfg80211_bss_ies *ies;
+	struct cfg80211_internal_bss *bss;
+	const u8 *ie;
+	int i, ssidlen;
+	u8 fold = 0;
+
+	ies = rcu_access_pointer(new->pub.beacon_ies);
+	if (WARN_ON(!ies))
+		return false;
+
+	ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
+	if (!ie) {
+		/* nothing to do */
+		return true;
+	}
+
+	ssidlen = ie[1];
+	for (i = 0; i < ssidlen; i++)
+		fold |= ie[2 + i];
+
+	if (fold) {
+		/* not a hidden SSID */
+		return true;
+	}
+
+	/* This is the bad part ... */
+
+	list_for_each_entry(bss, &rdev->bss_list, list) {
+		if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
+			continue;
+		if (bss->pub.channel != new->pub.channel)
+			continue;
+		if (bss->pub.scan_width != new->pub.scan_width)
+			continue;
+		if (rcu_access_pointer(bss->pub.beacon_ies))
+			continue;
+		ies = rcu_access_pointer(bss->pub.ies);
+		if (!ies)
+			continue;
+		ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
+		if (!ie)
+			continue;
+		if (ssidlen && ie[1] != ssidlen)
+			continue;
+		if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
+			continue;
+		if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
+			list_del(&bss->hidden_list);
+		/* combine them */
+		list_add(&bss->hidden_list, &new->hidden_list);
+		bss->pub.hidden_beacon_bss = &new->pub;
+		new->refcount += bss->refcount;
+		rcu_assign_pointer(bss->pub.beacon_ies,
+				   new->pub.beacon_ies);
+	}
+
+	return true;
+}
+
+/* Returned bss is reference counted and must be cleaned up appropriately. */
+static struct cfg80211_internal_bss *
+cfg80211_bss_update(struct cfg80211_registered_device *rdev,
+		    struct cfg80211_internal_bss *tmp,
+		    bool signal_valid)
+{
+	struct cfg80211_internal_bss *found = NULL;
+
+	if (WARN_ON(!tmp->pub.channel))
+		return NULL;
+
+	tmp->ts = jiffies;
+
+	spin_lock_bh(&rdev->bss_lock);
+
+	if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
+		spin_unlock_bh(&rdev->bss_lock);
+		return NULL;
+	}
+
+	found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR);
+
+	if (found) {
+		/* Update IEs */
+		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
+			const struct cfg80211_bss_ies *old;
+
+			old = rcu_access_pointer(found->pub.proberesp_ies);
+
+			rcu_assign_pointer(found->pub.proberesp_ies,
+					   tmp->pub.proberesp_ies);
+			/* Override possible earlier Beacon frame IEs */
+			rcu_assign_pointer(found->pub.ies,
+					   tmp->pub.proberesp_ies);
+			if (old)
+				kfree_rcu((struct cfg80211_bss_ies *)old,
+					  rcu_head);
+		} else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
+			const struct cfg80211_bss_ies *old;
+			struct cfg80211_internal_bss *bss;
+
+			if (found->pub.hidden_beacon_bss &&
+			    !list_empty(&found->hidden_list)) {
+				const struct cfg80211_bss_ies *f;
+
+				/*
+				 * The found BSS struct is one of the probe
+				 * response members of a group, but we're
+				 * receiving a beacon (beacon_ies in the tmp
+				 * bss is used). This can only mean that the
+				 * AP changed its beacon from not having an
+				 * SSID to showing it, which is confusing so
+				 * drop this information.
+				 */
+
+				f = rcu_access_pointer(tmp->pub.beacon_ies);
+				kfree_rcu((struct cfg80211_bss_ies *)f,
+					  rcu_head);
+				goto drop;
+			}
+
+			old = rcu_access_pointer(found->pub.beacon_ies);
+
+			rcu_assign_pointer(found->pub.beacon_ies,
+					   tmp->pub.beacon_ies);
+
+			/* Override IEs if they were from a beacon before */
+			if (old == rcu_access_pointer(found->pub.ies))
+				rcu_assign_pointer(found->pub.ies,
+						   tmp->pub.beacon_ies);
+
+			/* Assign beacon IEs to all sub entries */
+			list_for_each_entry(bss, &found->hidden_list,
+					    hidden_list) {
+				const struct cfg80211_bss_ies *ies;
+
+				ies = rcu_access_pointer(bss->pub.beacon_ies);
+				WARN_ON(ies != old);
+
+				rcu_assign_pointer(bss->pub.beacon_ies,
+						   tmp->pub.beacon_ies);
+			}
+
+			if (old)
+				kfree_rcu((struct cfg80211_bss_ies *)old,
+					  rcu_head);
+		}
+
+		found->pub.beacon_interval = tmp->pub.beacon_interval;
+		/*
+		 * don't update the signal if beacon was heard on
+		 * adjacent channel.
+		 */
+		if (signal_valid)
+			found->pub.signal = tmp->pub.signal;
+		found->pub.capability = tmp->pub.capability;
+		found->ts = tmp->ts;
+	} else {
+		struct cfg80211_internal_bss *new;
+		struct cfg80211_internal_bss *hidden;
+		struct cfg80211_bss_ies *ies;
+
+		/*
+		 * create a copy -- the "res" variable that is passed in
+		 * is allocated on the stack since it's not needed in the
+		 * more common case of an update
+		 */
+		new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size,
+			      GFP_ATOMIC);
+		if (!new) {
+			ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
+			if (ies)
+				kfree_rcu(ies, rcu_head);
+			ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
+			if (ies)
+				kfree_rcu(ies, rcu_head);
+			goto drop;
+		}
+		memcpy(new, tmp, sizeof(*new));
+		new->refcount = 1;
+		INIT_LIST_HEAD(&new->hidden_list);
+
+		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
+			hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
+			if (!hidden)
+				hidden = rb_find_bss(rdev, tmp,
+						     BSS_CMP_HIDE_NUL);
+			if (hidden) {
+				new->pub.hidden_beacon_bss = &hidden->pub;
+				list_add(&new->hidden_list,
+					 &hidden->hidden_list);
+				hidden->refcount++;
+				rcu_assign_pointer(new->pub.beacon_ies,
+						   hidden->pub.beacon_ies);
+			}
+		} else {
+			/*
+			 * Ok so we found a beacon, and don't have an entry. If
+			 * it's a beacon with hidden SSID, we might be in for an
+			 * expensive search for any probe responses that should
+			 * be grouped with this beacon for updates ...
+			 */
+			if (!cfg80211_combine_bsses(rdev, new)) {
+				kfree(new);
+				goto drop;
+			}
+		}
+
+		list_add_tail(&new->list, &rdev->bss_list);
+		rb_insert_bss(rdev, new);
+		found = new;
+	}
+
+	rdev->bss_generation++;
+	bss_ref_get(rdev, found);
+	spin_unlock_bh(&rdev->bss_lock);
+
+	return found;
+ drop:
+	spin_unlock_bh(&rdev->bss_lock);
+	return NULL;
+}
+
+static struct ieee80211_channel *
+cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
+			 struct ieee80211_channel *channel)
+{
+	const u8 *tmp;
+	u32 freq;
+	int channel_number = -1;
+
+	tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
+	if (tmp && tmp[1] == 1) {
+		channel_number = tmp[2];
+	} else {
+		tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
+		if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
+			struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
+
+			channel_number = htop->primary_chan;
+		}
+	}
+
+	if (channel_number < 0)
+		return channel;
+
+	freq = ieee80211_channel_to_frequency(channel_number, channel->band);
+	channel = ieee80211_get_channel(wiphy, freq);
+	if (!channel)
+		return NULL;
+	if (channel->flags & IEEE80211_CHAN_DISABLED)
+		return NULL;
+	return channel;
+}
+
+/* Returned bss is reference counted and must be cleaned up appropriately. */
+struct cfg80211_bss*
+cfg80211_inform_bss_width(struct wiphy *wiphy,
+			  struct ieee80211_channel *rx_channel,
+			  enum nl80211_bss_scan_width scan_width,
+			  enum cfg80211_bss_frame_type ftype,
+			  const u8 *bssid, u64 tsf, u16 capability,
+			  u16 beacon_interval, const u8 *ie, size_t ielen,
+			  s32 signal, gfp_t gfp)
+{
+	struct cfg80211_bss_ies *ies;
+	struct ieee80211_channel *channel;
+	struct cfg80211_internal_bss tmp = {}, *res;
+	int bss_type;
+	bool signal_valid;
+
+	if (WARN_ON(!wiphy))
+		return NULL;
+
+	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
+			(signal < 0 || signal > 100)))
+		return NULL;
+
+	channel = cfg80211_get_bss_channel(wiphy, ie, ielen, rx_channel);
+	if (!channel)
+		return NULL;
+
+	memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
+	tmp.pub.channel = channel;
+	tmp.pub.scan_width = scan_width;
+	tmp.pub.signal = signal;
+	tmp.pub.beacon_interval = beacon_interval;
+	tmp.pub.capability = capability;
+	/*
+	 * If we do not know here whether the IEs are from a Beacon or Probe
+	 * Response frame, we need to pick one of the options and only use it
+	 * with the driver that does not provide the full Beacon/Probe Response
+	 * frame. Use Beacon frame pointer to avoid indicating that this should
+	 * override the IEs pointer should we have received an earlier
+	 * indication of Probe Response data.
+	 */
+	ies = kzalloc(sizeof(*ies) + ielen, gfp);
+	if (!ies)
+		return NULL;
+	ies->len = ielen;
+	ies->tsf = tsf;
+	ies->from_beacon = false;
+	memcpy(ies->data, ie, ielen);
+
+	switch (ftype) {
+	case CFG80211_BSS_FTYPE_BEACON:
+		ies->from_beacon = true;
+		/* fall through to assign */
+	case CFG80211_BSS_FTYPE_UNKNOWN:
+		rcu_assign_pointer(tmp.pub.beacon_ies, ies);
+		break;
+	case CFG80211_BSS_FTYPE_PRESP:
+		rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
+		break;
+	}
+	rcu_assign_pointer(tmp.pub.ies, ies);
+
+	signal_valid = abs(rx_channel->center_freq - channel->center_freq) <=
+		wiphy->max_adj_channel_rssi_comp;
+	res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
+	if (!res)
+		return NULL;
+
+	if (channel->band == IEEE80211_BAND_60GHZ) {
+		bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
+		if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
+		    bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
+			regulatory_hint_found_beacon(wiphy, channel, gfp);
+	} else {
+		if (res->pub.capability & WLAN_CAPABILITY_ESS)
+			regulatory_hint_found_beacon(wiphy, channel, gfp);
+	}
+
+	trace_cfg80211_return_bss(&res->pub);
+	/* cfg80211_bss_update gives us a referenced result */
+	return &res->pub;
+}
+EXPORT_SYMBOL(cfg80211_inform_bss_width);
+
+/* Returned bss is reference counted and must be cleaned up appropriately. */
+struct cfg80211_bss *
+cfg80211_inform_bss_width_frame(struct wiphy *wiphy,
+				struct ieee80211_channel *rx_channel,
+				enum nl80211_bss_scan_width scan_width,
+				struct ieee80211_mgmt *mgmt, size_t len,
+				s32 signal, gfp_t gfp)
+{
+	struct cfg80211_internal_bss tmp = {}, *res;
+	struct cfg80211_bss_ies *ies;
+	struct ieee80211_channel *channel;
+	bool signal_valid;
+	size_t ielen = len - offsetof(struct ieee80211_mgmt,
+				      u.probe_resp.variable);
+	int bss_type;
+
+	BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
+			offsetof(struct ieee80211_mgmt, u.beacon.variable));
+
+	trace_cfg80211_inform_bss_width_frame(wiphy, rx_channel, scan_width, mgmt,
+					      len, signal);
+
+	if (WARN_ON(!mgmt))
+		return NULL;
+
+	if (WARN_ON(!wiphy))
+		return NULL;
+
+	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
+		    (signal < 0 || signal > 100)))
+		return NULL;
+
+	if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
+		return NULL;
+
+	channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
+					   ielen, rx_channel);
+	if (!channel)
+		return NULL;
+
+	ies = kzalloc(sizeof(*ies) + ielen, gfp);
+	if (!ies)
+		return NULL;
+	ies->len = ielen;
+	ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
+	ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control);
+	memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
+
+	if (ieee80211_is_probe_resp(mgmt->frame_control))
+		rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
+	else
+		rcu_assign_pointer(tmp.pub.beacon_ies, ies);
+	rcu_assign_pointer(tmp.pub.ies, ies);
+	
+	memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
+	tmp.pub.channel = channel;
+	tmp.pub.scan_width = scan_width;
+	tmp.pub.signal = signal;
+	tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
+	tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
+
+	signal_valid = abs(rx_channel->center_freq - channel->center_freq) <=
+		wiphy->max_adj_channel_rssi_comp;
+	res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid);
+	if (!res)
+		return NULL;
+
+	if (channel->band == IEEE80211_BAND_60GHZ) {
+		bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK;
+		if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP ||
+		    bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS)
+			regulatory_hint_found_beacon(wiphy, channel, gfp);
+	} else {
+		if (res->pub.capability & WLAN_CAPABILITY_ESS)
+			regulatory_hint_found_beacon(wiphy, channel, gfp);
+	}
+
+	trace_cfg80211_return_bss(&res->pub);
+	/* cfg80211_bss_update gives us a referenced result */
+	return &res->pub;
+}
+EXPORT_SYMBOL(cfg80211_inform_bss_width_frame);
+
+void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
+{
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+	struct cfg80211_internal_bss *bss;
+
+	if (!pub)
+		return;
+
+	bss = container_of(pub, struct cfg80211_internal_bss, pub);
+
+	spin_lock_bh(&rdev->bss_lock);
+	bss_ref_get(rdev, bss);
+	spin_unlock_bh(&rdev->bss_lock);
+}
+EXPORT_SYMBOL(cfg80211_ref_bss);
+
+void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
+{
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+	struct cfg80211_internal_bss *bss;
+
+	if (!pub)
+		return;
+
+	bss = container_of(pub, struct cfg80211_internal_bss, pub);
+
+	spin_lock_bh(&rdev->bss_lock);
+	bss_ref_put(rdev, bss);
+	spin_unlock_bh(&rdev->bss_lock);
+}
+EXPORT_SYMBOL(cfg80211_put_bss);
+
+void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
+{
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+	struct cfg80211_internal_bss *bss;
+
+	if (WARN_ON(!pub))
+		return;
+
+	bss = container_of(pub, struct cfg80211_internal_bss, pub);
+
+	spin_lock_bh(&rdev->bss_lock);
+	if (!list_empty(&bss->list)) {
+		if (__cfg80211_unlink_bss(rdev, bss))
+			rdev->bss_generation++;
+	}
+	spin_unlock_bh(&rdev->bss_lock);
+}
+EXPORT_SYMBOL(cfg80211_unlink_bss);
+
+#ifdef CONFIG_CFG80211_WEXT
+static struct cfg80211_registered_device *
+cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
+{
+	struct cfg80211_registered_device *rdev;
+	struct net_device *dev;
+
+	ASSERT_RTNL();
+
+	dev = dev_get_by_index(net, ifindex);
+	if (!dev)
+		return ERR_PTR(-ENODEV);
+	if (dev->ieee80211_ptr)
+		rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy);
+	else
+		rdev = ERR_PTR(-ENODEV);
+	dev_put(dev);
+	return rdev;
+}
+
+int cfg80211_wext_siwscan(struct net_device *dev,
+			  struct iw_request_info *info,
+			  union iwreq_data *wrqu, char *extra)
+{
+	struct cfg80211_registered_device *rdev;
+	struct wiphy *wiphy;
+	struct iw_scan_req *wreq = NULL;
+	struct cfg80211_scan_request *creq = NULL;
+	int i, err, n_channels = 0;
+	enum ieee80211_band band;
+
+	if (!netif_running(dev))
+		return -ENETDOWN;
+
+	if (wrqu->data.length == sizeof(struct iw_scan_req))
+		wreq = (struct iw_scan_req *)extra;
+
+	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
+
+	if (IS_ERR(rdev))
+		return PTR_ERR(rdev);
+
+	if (rdev->scan_req || rdev->scan_msg) {
+		err = -EBUSY;
+		goto out;
+	}
+
+	wiphy = &rdev->wiphy;
+
+	/* Determine number of channels, needed to allocate creq */
+	if (wreq && wreq->num_channels)
+		n_channels = wreq->num_channels;
+	else
+		n_channels = ieee80211_get_num_supported_channels(wiphy);
+
+	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
+		       n_channels * sizeof(void *),
+		       GFP_ATOMIC);
+	if (!creq) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	creq->wiphy = wiphy;
+	creq->wdev = dev->ieee80211_ptr;
+	/* SSIDs come after channels */
+	creq->ssids = (void *)&creq->channels[n_channels];
+	creq->n_channels = n_channels;
+	creq->n_ssids = 1;
+	creq->scan_start = jiffies;
+
+	/* translate "Scan on frequencies" request */
+	i = 0;
+	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+		int j;
+
+		if (!wiphy->bands[band])
+			continue;
+
+		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
+			/* ignore disabled channels */
+			if (wiphy->bands[band]->channels[j].flags &
+						IEEE80211_CHAN_DISABLED)
+				continue;
+
+			/* If we have a wireless request structure and the
+			 * wireless request specifies frequencies, then search
+			 * for the matching hardware channel.
+			 */
+			if (wreq && wreq->num_channels) {
+				int k;
+				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
+				for (k = 0; k < wreq->num_channels; k++) {
+					struct iw_freq *freq =
+						&wreq->channel_list[k];
+					int wext_freq =
+						cfg80211_wext_freq(freq);
+
+					if (wext_freq == wiphy_freq)
+						goto wext_freq_found;
+				}
+				goto wext_freq_not_found;
+			}
+
+		wext_freq_found:
+			creq->channels[i] = &wiphy->bands[band]->channels[j];
+			i++;
+		wext_freq_not_found: ;
+		}
+	}
+	/* No channels found? */
+	if (!i) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	/* Set real number of channels specified in creq->channels[] */
+	creq->n_channels = i;
+
+	/* translate "Scan for SSID" request */
+	if (wreq) {
+		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
+			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
+				err = -EINVAL;
+				goto out;
+			}
+			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
+			creq->ssids[0].ssid_len = wreq->essid_len;
+		}
+		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
+			creq->n_ssids = 0;
+	}
+
+	for (i = 0; i < IEEE80211_NUM_BANDS; i++)
+		if (wiphy->bands[i])
+			creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
+
+	rdev->scan_req = creq;
+	err = rdev_scan(rdev, creq);
+	if (err) {
+		rdev->scan_req = NULL;
+		/* creq will be freed below */
+	} else {
+		nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
+		/* creq now owned by driver */
+		creq = NULL;
+		dev_hold(dev);
+	}
+ out:
+	kfree(creq);
+	return err;
+}
+EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan);
+
+static char *ieee80211_scan_add_ies(struct iw_request_info *info,
+				    const struct cfg80211_bss_ies *ies,
+				    char *current_ev, char *end_buf)
+{
+	const u8 *pos, *end, *next;
+	struct iw_event iwe;
+
+	if (!ies)
+		return current_ev;
+
+	/*
+	 * If needed, fragment the IEs buffer (at IE boundaries) into short
+	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
+	 */
+	pos = ies->data;
+	end = pos + ies->len;
+
+	while (end - pos > IW_GENERIC_IE_MAX) {
+		next = pos + 2 + pos[1];
+		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
+			next = next + 2 + next[1];
+
+		memset(&iwe, 0, sizeof(iwe));
+		iwe.cmd = IWEVGENIE;
+		iwe.u.data.length = next - pos;
+		current_ev = iwe_stream_add_point_check(info, current_ev,
+							end_buf, &iwe,
+							(void *)pos);
+		if (IS_ERR(current_ev))
+			return current_ev;
+		pos = next;
+	}
+
+	if (end > pos) {
+		memset(&iwe, 0, sizeof(iwe));
+		iwe.cmd = IWEVGENIE;
+		iwe.u.data.length = end - pos;
+		current_ev = iwe_stream_add_point_check(info, current_ev,
+							end_buf, &iwe,
+							(void *)pos);
+		if (IS_ERR(current_ev))
+			return current_ev;
+	}
+
+	return current_ev;
+}
+
+static char *
+ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
+	      struct cfg80211_internal_bss *bss, char *current_ev,
+	      char *end_buf)
+{
+	const struct cfg80211_bss_ies *ies;
+	struct iw_event iwe;
+	const u8 *ie;
+	u8 buf[50];
+	u8 *cfg, *p, *tmp;
+	int rem, i, sig;
+	bool ismesh = false;
+
+	memset(&iwe, 0, sizeof(iwe));
+	iwe.cmd = SIOCGIWAP;
+	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
+	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
+	current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
+						IW_EV_ADDR_LEN);
+	if (IS_ERR(current_ev))
+		return current_ev;
+
+	memset(&iwe, 0, sizeof(iwe));
+	iwe.cmd = SIOCGIWFREQ;
+	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
+	iwe.u.freq.e = 0;
+	current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
+						IW_EV_FREQ_LEN);
+	if (IS_ERR(current_ev))
+		return current_ev;
+
+	memset(&iwe, 0, sizeof(iwe));
+	iwe.cmd = SIOCGIWFREQ;
+	iwe.u.freq.m = bss->pub.channel->center_freq;
+	iwe.u.freq.e = 6;
+	current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe,
+						IW_EV_FREQ_LEN);
+	if (IS_ERR(current_ev))
+		return current_ev;
+
+	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
+		memset(&iwe, 0, sizeof(iwe));
+		iwe.cmd = IWEVQUAL;
+		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
+				     IW_QUAL_NOISE_INVALID |
+				     IW_QUAL_QUAL_UPDATED;
+		switch (wiphy->signal_type) {
+		case CFG80211_SIGNAL_TYPE_MBM:
+			sig = bss->pub.signal / 100;
+			iwe.u.qual.level = sig;
+			iwe.u.qual.updated |= IW_QUAL_DBM;
+			if (sig < -110)		/* rather bad */
+				sig = -110;
+			else if (sig > -40)	/* perfect */
+				sig = -40;
+			/* will give a range of 0 .. 70 */
+			iwe.u.qual.qual = sig + 110;
+			break;
+		case CFG80211_SIGNAL_TYPE_UNSPEC:
+			iwe.u.qual.level = bss->pub.signal;
+			/* will give range 0 .. 100 */
+			iwe.u.qual.qual = bss->pub.signal;
+			break;
+		default:
+			/* not reached */
+			break;
+		}
+		current_ev = iwe_stream_add_event_check(info, current_ev,
+							end_buf, &iwe,
+							IW_EV_QUAL_LEN);
+		if (IS_ERR(current_ev))
+			return current_ev;
+	}
+
+	memset(&iwe, 0, sizeof(iwe));
+	iwe.cmd = SIOCGIWENCODE;
+	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
+		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
+	else
+		iwe.u.data.flags = IW_ENCODE_DISABLED;
+	iwe.u.data.length = 0;
+	current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
+						&iwe, "");
+	if (IS_ERR(current_ev))
+		return current_ev;
+
+	rcu_read_lock();
+	ies = rcu_dereference(bss->pub.ies);
+	rem = ies->len;
+	ie = ies->data;
+
+	while (rem >= 2) {
+		/* invalid data */
+		if (ie[1] > rem - 2)
+			break;
+
+		switch (ie[0]) {
+		case WLAN_EID_SSID:
+			memset(&iwe, 0, sizeof(iwe));
+			iwe.cmd = SIOCGIWESSID;
+			iwe.u.data.length = ie[1];
+			iwe.u.data.flags = 1;
+			current_ev = iwe_stream_add_point_check(info,
+								current_ev,
+								end_buf, &iwe,
+								(u8 *)ie + 2);
+			if (IS_ERR(current_ev))
+				goto unlock;
+			break;
+		case WLAN_EID_MESH_ID:
+			memset(&iwe, 0, sizeof(iwe));
+			iwe.cmd = SIOCGIWESSID;
+			iwe.u.data.length = ie[1];
+			iwe.u.data.flags = 1;
+			current_ev = iwe_stream_add_point_check(info,
+								current_ev,
+								end_buf, &iwe,
+								(u8 *)ie + 2);
+			if (IS_ERR(current_ev))
+				goto unlock;
+			break;
+		case WLAN_EID_MESH_CONFIG:
+			ismesh = true;
+			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
+				break;
+			cfg = (u8 *)ie + 2;
+			memset(&iwe, 0, sizeof(iwe));
+			iwe.cmd = IWEVCUSTOM;
+			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
+				"0x%02X", cfg[0]);
+			iwe.u.data.length = strlen(buf);
+			current_ev = iwe_stream_add_point_check(info,
+								current_ev,
+								end_buf,
+								&iwe, buf);
+			if (IS_ERR(current_ev))
+				goto unlock;
+			sprintf(buf, "Path Selection Metric ID: 0x%02X",
+				cfg[1]);
+			iwe.u.data.length = strlen(buf);
+			current_ev = iwe_stream_add_point_check(info,
+								current_ev,
+								end_buf,
+								&iwe, buf);
+			if (IS_ERR(current_ev))
+				goto unlock;
+			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
+				cfg[2]);
+			iwe.u.data.length = strlen(buf);
+			current_ev = iwe_stream_add_point_check(info,
+								current_ev,
+								end_buf,
+								&iwe, buf);
+			if (IS_ERR(current_ev))
+				goto unlock;
+			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
+			iwe.u.data.length = strlen(buf);
+			current_ev = iwe_stream_add_point_check(info,
+								current_ev,
+								end_buf,
+								&iwe, buf);
+			if (IS_ERR(current_ev))
+				goto unlock;
+			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
+			iwe.u.data.length = strlen(buf);
+			current_ev = iwe_stream_add_point_check(info,
+								current_ev,
+								end_buf,
+								&iwe, buf);
+			if (IS_ERR(current_ev))
+				goto unlock;
+			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
+			iwe.u.data.length = strlen(buf);
+			current_ev = iwe_stream_add_point_check(info,
+								current_ev,
+								end_buf,
+								&iwe, buf);
+			if (IS_ERR(current_ev))
+				goto unlock;
+			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
+			iwe.u.data.length = strlen(buf);
+			current_ev = iwe_stream_add_point_check(info,
+								current_ev,
+								end_buf,
+								&iwe, buf);
+			if (IS_ERR(current_ev))
+				goto unlock;
+			break;
+		case WLAN_EID_SUPP_RATES:
+		case WLAN_EID_EXT_SUPP_RATES:
+			/* display all supported rates in readable format */
+			p = current_ev + iwe_stream_lcp_len(info);
+
+			memset(&iwe, 0, sizeof(iwe));
+			iwe.cmd = SIOCGIWRATE;
+			/* Those two flags are ignored... */
+			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
+
+			for (i = 0; i < ie[1]; i++) {
+				iwe.u.bitrate.value =
+					((ie[i + 2] & 0x7f) * 500000);
+				tmp = p;
+				p = iwe_stream_add_value(info, current_ev, p,
+							 end_buf, &iwe,
+							 IW_EV_PARAM_LEN);
+				if (p == tmp) {
+					current_ev = ERR_PTR(-E2BIG);
+					goto unlock;
+				}
+			}
+			current_ev = p;
+			break;
+		}
+		rem -= ie[1] + 2;
+		ie += ie[1] + 2;
+	}
+
+	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
+	    ismesh) {
+		memset(&iwe, 0, sizeof(iwe));
+		iwe.cmd = SIOCGIWMODE;
+		if (ismesh)
+			iwe.u.mode = IW_MODE_MESH;
+		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
+			iwe.u.mode = IW_MODE_MASTER;
+		else
+			iwe.u.mode = IW_MODE_ADHOC;
+		current_ev = iwe_stream_add_event_check(info, current_ev,
+							end_buf, &iwe,
+							IW_EV_UINT_LEN);
+		if (IS_ERR(current_ev))
+			goto unlock;
+	}
+
+	memset(&iwe, 0, sizeof(iwe));
+	iwe.cmd = IWEVCUSTOM;
+	sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
+	iwe.u.data.length = strlen(buf);
+	current_ev = iwe_stream_add_point_check(info, current_ev, end_buf,
+						&iwe, buf);
+	if (IS_ERR(current_ev))
+		goto unlock;
+	memset(&iwe, 0, sizeof(iwe));
+	iwe.cmd = IWEVCUSTOM;
+	sprintf(buf, " Last beacon: %ums ago",
+		elapsed_jiffies_msecs(bss->ts));
+	iwe.u.data.length = strlen(buf);
+	current_ev = iwe_stream_add_point_check(info, current_ev,
+						end_buf, &iwe, buf);
+	if (IS_ERR(current_ev))
+		goto unlock;
+
+	current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf);
+
+ unlock:
+	rcu_read_unlock();
+	return current_ev;
+}
+
+
+static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
+				  struct iw_request_info *info,
+				  char *buf, size_t len)
+{
+	char *current_ev = buf;
+	char *end_buf = buf + len;
+	struct cfg80211_internal_bss *bss;
+	int err = 0;
+
+	spin_lock_bh(&rdev->bss_lock);
+	cfg80211_bss_expire(rdev);
+
+	list_for_each_entry(bss, &rdev->bss_list, list) {
+		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
+			err = -E2BIG;
+			break;
+		}
+		current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
+					   current_ev, end_buf);
+		if (IS_ERR(current_ev)) {
+			err = PTR_ERR(current_ev);
+			break;
+		}
+	}
+	spin_unlock_bh(&rdev->bss_lock);
+
+	if (err)
+		return err;
+	return current_ev - buf;
+}
+
+
+int cfg80211_wext_giwscan(struct net_device *dev,
+			  struct iw_request_info *info,
+			  struct iw_point *data, char *extra)
+{
+	struct cfg80211_registered_device *rdev;
+	int res;
+
+	if (!netif_running(dev))
+		return -ENETDOWN;
+
+	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
+
+	if (IS_ERR(rdev))
+		return PTR_ERR(rdev);
+
+	if (rdev->scan_req || rdev->scan_msg)
+		return -EAGAIN;
+
+	res = ieee80211_scan_results(rdev, info, extra, data->length);
+	data->length = 0;
+	if (res >= 0) {
+		data->length = res;
+		res = 0;
+	}
+
+	return res;
+}
+EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan);
+#endif