1 files changed, 336 insertions, 296 deletions

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 01592d7d478..674aadca007 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -19,55 +19,142 @@
 #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_release(struct kref *ref)
+static void bss_free(struct cfg80211_internal_bss *bss)
 {
 	struct cfg80211_bss_ies *ies;
-	struct cfg80211_internal_bss *bss;
-
-	bss = container_of(ref, struct cfg80211_internal_bss, ref);
 
 	if (WARN_ON(atomic_read(&bss->hold)))
 		return;
 
-	if (bss->pub.free_priv)
-		bss->pub.free_priv(&bss->pub);
-
 	ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
-	if (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);
 }
 
-/* must hold dev->bss_lock! */
-static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
+static inline void bss_ref_get(struct cfg80211_registered_device *dev,
+			       struct cfg80211_internal_bss *bss)
+{
+	lockdep_assert_held(&dev->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 *dev,
+			       struct cfg80211_internal_bss *bss)
+{
+	lockdep_assert_held(&dev->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 *dev,
 				  struct cfg80211_internal_bss *bss)
 {
+	lockdep_assert_held(&dev->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, &dev->bss_tree);
-	kref_put(&bss->ref, bss_release);
+	bss_ref_put(dev, bss);
+	return true;
 }
 
-/* must hold dev->bss_lock! */
 static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev,
 				  unsigned long expire_time)
 {
 	struct cfg80211_internal_bss *bss, *tmp;
 	bool expired = false;
 
+	lockdep_assert_held(&dev->bss_lock);
+
 	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
 		if (atomic_read(&bss->hold))
 			continue;
 		if (!time_after(expire_time, bss->ts))
 			continue;
 
-		__cfg80211_unlink_bss(dev, bss);
-		expired = true;
+		if (__cfg80211_unlink_bss(dev, bss))
+			expired = true;
 	}
 
 	if (expired)
@@ -234,15 +321,16 @@ int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
 	return 0;
 }
 
-/* must hold dev->bss_lock! */
 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
                       unsigned long age_secs)
 {
 	struct cfg80211_internal_bss *bss;
 	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
 
+	spin_lock_bh(&dev->bss_lock);
 	list_for_each_entry(bss, &dev->bss_list, list)
 		bss->ts -= age_jiffies;
+	spin_unlock_bh(&dev->bss_lock);
 }
 
 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
@@ -277,40 +365,24 @@ const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
 		if (!pos)
 			return NULL;
 
-		if (end - pos < sizeof(*ie))
-			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 int cmp_ies(u8 num, const u8 *ies1, int len1, const u8 *ies2, int len2)
-{
-	const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
-	const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
-
-	/* equal if both missing */
-	if (!ie1 && !ie2)
-		return 0;
-	/* sort missing IE before (left of) present IE */
-	if (!ie1)
-		return -1;
-	if (!ie2)
-		return 1;
-
-	/* 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]);
-}
-
 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 		   const u8 *ssid, size_t ssid_len)
 {
@@ -334,109 +406,30 @@ static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
 }
 
-static bool is_mesh_bss(struct cfg80211_bss *a)
-{
-	const struct cfg80211_bss_ies *ies;
-	const u8 *ie;
-
-	if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
-		return false;
-
-	ies = rcu_access_pointer(a->ies);
-	if (!ies)
-		return false;
-
-	ie = cfg80211_find_ie(WLAN_EID_MESH_ID, ies->data, ies->len);
-	if (!ie)
-		return false;
-
-	ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, ies->data, ies->len);
-	if (!ie)
-		return false;
-
-	return true;
-}
-
-static bool is_mesh(struct cfg80211_bss *a,
-		    const u8 *meshid, size_t meshidlen,
-		    const u8 *meshcfg)
-{
-	const struct cfg80211_bss_ies *ies;
-	const u8 *ie;
-
-	if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
-		return false;
-
-	ies = rcu_access_pointer(a->ies);
-	if (!ies)
-		return false;
-
-	ie = cfg80211_find_ie(WLAN_EID_MESH_ID, ies->data, ies->len);
-	if (!ie)
-		return false;
-	if (ie[1] != meshidlen)
-		return false;
-	if (memcmp(ie + 2, meshid, meshidlen))
-		return false;
-
-	ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, ies->data, ies->len);
-	if (!ie)
-		return false;
-	if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
-		return false;
-
-	/*
-	 * Ignore mesh capability (last two bytes of the IE) when
-	 * comparing since that may differ between stations taking
-	 * part in the same mesh.
-	 */
-	return memcmp(ie + 2, meshcfg,
-		      sizeof(struct ieee80211_meshconf_ie) - 2) == 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_core(struct cfg80211_bss *a, struct cfg80211_bss *b)
+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;
-	int r;
+	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;
 
-	if (is_mesh_bss(a) && is_mesh_bss(b)) {
-		a_ies = rcu_access_pointer(a->ies);
-		if (!a_ies)
-			return -1;
-		b_ies = rcu_access_pointer(b->ies);
-		if (!b_ies)
-			return 1;
-
-		r = cmp_ies(WLAN_EID_MESH_ID,
-			    a_ies->data, a_ies->len,
-			    b_ies->data, b_ies->len);
-		if (r)
-			return r;
-		return cmp_ies(WLAN_EID_MESH_CONFIG,
-			       a_ies->data, a_ies->len,
-			       b_ies->data, b_ies->len);
-	}
-
-	/*
-	 * we can't use compare_ether_addr here since we need a < > operator.
-	 * The binary return value of compare_ether_addr isn't enough
-	 */
-	return memcmp(a->bssid, b->bssid, sizeof(a->bssid));
-}
-
-static int cmp_bss(struct cfg80211_bss *a,
-		   struct cfg80211_bss *b)
-{
-	const struct cfg80211_bss_ies *a_ies, *b_ies;
-	int r;
-
-	r = cmp_bss_core(a, b);
-	if (r)
-		return r;
-
 	a_ies = rcu_access_pointer(a->ies);
 	if (!a_ies)
 		return -1;
@@ -444,42 +437,51 @@ static int cmp_bss(struct cfg80211_bss *a,
 	if (!b_ies)
 		return 1;
 
-	return cmp_ies(WLAN_EID_SSID,
-		       a_ies->data, a_ies->len,
-		       b_ies->data, b_ies->len);
-}
-
-static int cmp_hidden_bss(struct cfg80211_bss *a, struct cfg80211_bss *b)
-{
-	const struct cfg80211_bss_ies *a_ies, *b_ies;
-	const u8 *ie1;
-	const u8 *ie2;
-	int i;
-	int r;
+	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 = cmp_bss_core(a, b);
+	/*
+	 * we can't use compare_ether_addr here since we need a < > operator.
+	 * The binary return value of compare_ether_addr isn't enough
+	 */
+	r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
 	if (r)
 		return r;
 
-	a_ies = rcu_access_pointer(a->ies);
-	if (!a_ies)
-		return -1;
-	b_ies = rcu_access_pointer(b->ies);
-	if (!b_ies)
-		return 1;
-
 	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;
+
 	/*
-	 * Key comparator must use same algorithm in any rb-tree
-	 * search function (order is important), otherwise ordering
-	 * of items in the tree is broken and search gives incorrect
-	 * results. This code uses same order as cmp_ies() does.
-	 *
-	 * Note that due to the differring behaviour with hidden SSIDs
-	 * this function only works when "b" is the tree element and
-	 * "a" is the key we're looking for.
+	 * 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 */
@@ -488,24 +490,36 @@ static int cmp_hidden_bss(struct cfg80211_bss *a, struct cfg80211_bss *b)
 	if (!ie2)
 		return 1;
 
-	/* zero-size SSID is used as an indication of the hidden bss */
-	if (!ie2[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;
-
-	/* sort by length first, then by contents */
-	if (ie1[1] != ie2[1])
-		return ie2[1] - ie1[1];
-
-	/*
-	 * zeroed SSID ie is another indication of a hidden bss;
-	 * if it isn't zeroed just return the regular sort value
-	 * to find the next candidate
-	 */
-	for (i = 0; i < ie2[1]; i++)
-		if (ie2[i + 2])
-			return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
-
-	return 0;
+	}
 }
 
 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
@@ -534,7 +548,7 @@ struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 			continue;
 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 			res = bss;
-			kref_get(&res->ref);
+			bss_ref_get(dev, res);
 			break;
 		}
 	}
@@ -547,34 +561,6 @@ struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
 }
 EXPORT_SYMBOL(cfg80211_get_bss);
 
-struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
-				       struct ieee80211_channel *channel,
-				       const u8 *meshid, size_t meshidlen,
-				       const u8 *meshcfg)
-{
-	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
-	struct cfg80211_internal_bss *bss, *res = NULL;
-
-	spin_lock_bh(&dev->bss_lock);
-
-	list_for_each_entry(bss, &dev->bss_list, list) {
-		if (channel && bss->pub.channel != channel)
-			continue;
-		if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
-			res = bss;
-			kref_get(&res->ref);
-			break;
-		}
-	}
-
-	spin_unlock_bh(&dev->bss_lock);
-	if (!res)
-		return NULL;
-	return &res->pub;
-}
-EXPORT_SYMBOL(cfg80211_get_mesh);
-
-
 static void rb_insert_bss(struct cfg80211_registered_device *dev,
 			  struct cfg80211_internal_bss *bss)
 {
@@ -587,7 +573,7 @@ static void rb_insert_bss(struct cfg80211_registered_device *dev,
 		parent = *p;
 		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
 
-		cmp = cmp_bss(&bss->pub, &tbss->pub);
+		cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
 
 		if (WARN_ON(!cmp)) {
 			/* will sort of leak this BSS */
@@ -606,7 +592,8 @@ static void rb_insert_bss(struct cfg80211_registered_device *dev,
 
 static struct cfg80211_internal_bss *
 rb_find_bss(struct cfg80211_registered_device *dev,
-	    struct cfg80211_internal_bss *res)
+	    struct cfg80211_internal_bss *res,
+	    enum bss_compare_mode mode)
 {
 	struct rb_node *n = dev->bss_tree.rb_node;
 	struct cfg80211_internal_bss *bss;
@@ -614,7 +601,7 @@ rb_find_bss(struct cfg80211_registered_device *dev,
 
 	while (n) {
 		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
-		r = cmp_bss(&res->pub, &bss->pub);
+		r = cmp_bss(&res->pub, &bss->pub, mode);
 
 		if (r == 0)
 			return bss;
@@ -627,46 +614,67 @@ rb_find_bss(struct cfg80211_registered_device *dev,
 	return NULL;
 }
 
-static struct cfg80211_internal_bss *
-rb_find_hidden_bss(struct cfg80211_registered_device *dev,
-		   struct cfg80211_internal_bss *res)
+static bool cfg80211_combine_bsses(struct cfg80211_registered_device *dev,
+				   struct cfg80211_internal_bss *new)
 {
-	struct rb_node *n = dev->bss_tree.rb_node;
+	const struct cfg80211_bss_ies *ies;
 	struct cfg80211_internal_bss *bss;
-	int r;
+	const u8 *ie;
+	int i, ssidlen;
+	u8 fold = 0;
 
-	while (n) {
-		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
-		r = cmp_hidden_bss(&res->pub, &bss->pub);
+	ies = rcu_access_pointer(new->pub.beacon_ies);
+	if (WARN_ON(!ies))
+		return false;
 
-		if (r == 0)
-			return bss;
-		else if (r < 0)
-			n = n->rb_left;
-		else
-			n = n->rb_right;
+	ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
+	if (!ie) {
+		/* nothing to do */
+		return true;
 	}
 
-	return NULL;
-}
+	ssidlen = ie[1];
+	for (i = 0; i < ssidlen; i++)
+		fold |= ie[2 + i];
 
-static void
-copy_hidden_ies(struct cfg80211_internal_bss *res,
-		struct cfg80211_internal_bss *hidden)
-{
-	const struct cfg80211_bss_ies *ies;
+	if (fold) {
+		/* not a hidden SSID */
+		return true;
+	}
 
-	if (rcu_access_pointer(res->pub.beacon_ies))
-		return;
+	/* This is the bad part ... */
 
-	ies = rcu_access_pointer(hidden->pub.beacon_ies);
-	if (WARN_ON(!ies))
-		return;
+	list_for_each_entry(bss, &dev->bss_list, list) {
+		if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
+			continue;
+		if (bss->pub.channel != new->pub.channel)
+			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;
+		/* that would be odd ... */
+		if (bss->pub.beacon_ies)
+			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);
+	}
 
-	ies = kmemdup(ies, sizeof(*ies) + ies->len, GFP_ATOMIC);
-	if (unlikely(!ies))
-		return;
-	rcu_assign_pointer(res->pub.beacon_ies, ies);
+	return true;
 }
 
 static struct cfg80211_internal_bss *
@@ -687,11 +695,10 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev,
 		return NULL;
 	}
 
-	found = rb_find_bss(dev, tmp);
+	found = rb_find_bss(dev, tmp, BSS_CMP_REGULAR);
 
 	if (found) {
 		found->pub.beacon_interval = tmp->pub.beacon_interval;
-		found->pub.tsf = tmp->pub.tsf;
 		found->pub.signal = tmp->pub.signal;
 		found->pub.capability = tmp->pub.capability;
 		found->ts = tmp->ts;
@@ -711,19 +718,45 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev,
 				kfree_rcu((struct cfg80211_bss_ies *)old,
 					  rcu_head);
 		} else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
-			const struct cfg80211_bss_ies *old, *ies;
+			const struct cfg80211_bss_ies *old;
+			struct cfg80211_internal_bss *bss;
+
+			if (found->pub.hidden_beacon_bss &&
+			    !list_empty(&found->hidden_list)) {
+				/*
+				 * 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.
+				 */
+				goto drop;
+			}
 
 			old = rcu_access_pointer(found->pub.beacon_ies);
-			ies = rcu_access_pointer(found->pub.ies);
 
 			rcu_assign_pointer(found->pub.beacon_ies,
 					   tmp->pub.beacon_ies);
 
 			/* Override IEs if they were from a beacon before */
-			if (old == ies)
+			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);
@@ -733,19 +766,6 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev,
 		struct cfg80211_internal_bss *hidden;
 		struct cfg80211_bss_ies *ies;
 
-		/* First check if the beacon is a probe response from
-		 * a hidden bss. If so, copy beacon ies (with nullified
-		 * ssid) into the probe response bss entry (with real ssid).
-		 * It is required basically for PSM implementation
-		 * (probe responses do not contain tim ie) */
-
-		/* TODO: The code is not trying to update existing probe
-		 * response bss entries when beacon ies are
-		 * getting changed. */
-		hidden = rb_find_hidden_bss(dev, tmp);
-		if (hidden)
-			copy_hidden_ies(tmp, hidden);
-
 		/*
 		 * create a copy -- the "res" variable that is passed in
 		 * is allocated on the stack since it's not needed in the
@@ -760,21 +780,51 @@ cfg80211_bss_update(struct cfg80211_registered_device *dev,
 			ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
 			if (ies)
 				kfree_rcu(ies, rcu_head);
-			spin_unlock_bh(&dev->bss_lock);
-			return NULL;
+			goto drop;
 		}
 		memcpy(new, tmp, sizeof(*new));
-		kref_init(&new->ref);
+		new->refcount = 1;
+		INIT_LIST_HEAD(&new->hidden_list);
+
+		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
+			hidden = rb_find_bss(dev, tmp, BSS_CMP_HIDE_ZLEN);
+			if (!hidden)
+				hidden = rb_find_bss(dev, 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(dev, new)) {
+				kfree(new);
+				goto drop;
+			}
+		}
+
 		list_add_tail(&new->list, &dev->bss_list);
 		rb_insert_bss(dev, new);
 		found = new;
 	}
 
 	dev->bss_generation++;
+	bss_ref_get(dev, found);
 	spin_unlock_bh(&dev->bss_lock);
 
-	kref_get(&found->ref);
 	return found;
+ drop:
+	spin_unlock_bh(&dev->bss_lock);
+	return NULL;
 }
 
 static struct ieee80211_channel *
@@ -833,7 +883,6 @@ cfg80211_inform_bss(struct wiphy *wiphy,
 	memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
 	tmp.pub.channel = channel;
 	tmp.pub.signal = signal;
-	tmp.pub.tsf = tsf;
 	tmp.pub.beacon_interval = beacon_interval;
 	tmp.pub.capability = capability;
 	/*
@@ -841,16 +890,14 @@ cfg80211_inform_bss(struct wiphy *wiphy,
 	 * 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 iies pointer should we have received an earlier
+	 * override the IEs pointer should we have received an earlier
 	 * indication of Probe Response data.
-	 *
-	 * The initial buffer for the IEs is allocated with the BSS entry and
-	 * is located after the private area.
 	 */
 	ies = kmalloc(sizeof(*ies) + ielen, gfp);
 	if (!ies)
 		return NULL;
 	ies->len = ielen;
+	ies->tsf = tsf;
 	memcpy(ies->data, ie, ielen);
 
 	rcu_assign_pointer(tmp.pub.beacon_ies, ies);
@@ -907,6 +954,7 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy,
 	if (!ies)
 		return NULL;
 	ies->len = ielen;
+	ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 	memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
 
 	if (ieee80211_is_probe_resp(mgmt->frame_control))
@@ -918,7 +966,6 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy,
 	memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
 	tmp.pub.channel = channel;
 	tmp.pub.signal = signal;
-	tmp.pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
 	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);
 
@@ -935,27 +982,35 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy,
 }
 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
 
-void cfg80211_ref_bss(struct cfg80211_bss *pub)
+void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 {
+	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 	struct cfg80211_internal_bss *bss;
 
 	if (!pub)
 		return;
 
 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
-	kref_get(&bss->ref);
+
+	spin_lock_bh(&dev->bss_lock);
+	bss_ref_get(dev, bss);
+	spin_unlock_bh(&dev->bss_lock);
 }
 EXPORT_SYMBOL(cfg80211_ref_bss);
 
-void cfg80211_put_bss(struct cfg80211_bss *pub)
+void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 {
+	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 	struct cfg80211_internal_bss *bss;
 
 	if (!pub)
 		return;
 
 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
-	kref_put(&bss->ref, bss_release);
+
+	spin_lock_bh(&dev->bss_lock);
+	bss_ref_put(dev, bss);
+	spin_unlock_bh(&dev->bss_lock);
 }
 EXPORT_SYMBOL(cfg80211_put_bss);
 
@@ -971,8 +1026,8 @@ void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
 
 	spin_lock_bh(&dev->bss_lock);
 	if (!list_empty(&bss->list)) {
-		__cfg80211_unlink_bss(dev, bss);
-		dev->bss_generation++;
+		if (__cfg80211_unlink_bss(dev, bss))
+			dev->bss_generation++;
 	}
 	spin_unlock_bh(&dev->bss_lock);
 }
@@ -1155,16 +1210,6 @@ static void ieee80211_scan_add_ies(struct iw_request_info *info,
 	}
 }
 
-static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
-{
-	unsigned long end = jiffies;
-
-	if (end >= start)
-		return jiffies_to_msecs(end - start);
-
-	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
-}
-
 static char *
 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 	      struct cfg80211_internal_bss *bss, char *current_ev,
@@ -1241,15 +1286,10 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 
 	rcu_read_lock();
 	ies = rcu_dereference(bss->pub.ies);
-	if (ies) {
-		rem = ies->len;
-		ie = ies->data;
-	} else {
-		rem = 0;
-		ie = NULL;
-	}
+	rem = ies->len;
+	ie = ies->data;
 
-	while (ies && rem >= 2) {
+	while (rem >= 2) {
 		/* invalid data */
 		if (ie[1] > rem - 2)
 			break;
@@ -1358,11 +1398,11 @@ ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
 						  &iwe, IW_EV_UINT_LEN);
 	}
 
-	buf = kmalloc(30, GFP_ATOMIC);
+	buf = kmalloc(31, GFP_ATOMIC);
 	if (buf) {
 		memset(&iwe, 0, sizeof(iwe));
 		iwe.cmd = IWEVCUSTOM;
-		sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
+		sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
 		iwe.u.data.length = strlen(buf);
 		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
 						  &iwe, buf);