cfg80211: Add support for randomizing TA of Public Action frames

Add support to use a random local address (Address 2 = TA in transmit
and the same address in receive functionality) for Public Action frames
in order to improve privacy of WLAN clients. Applications fill the
random transmit address in the frame buffer in the NL80211_CMD_FRAME
command. This can be used only with the drivers that indicate support
for random local address by setting the new
NL80211_EXT_FEATURE_MGMT_TX_RANDOM_TA and/or
NL80211_EXT_FEATURE_MGMT_TX_RANDOM_TA_CONNECTED in ext_features.

The driver needs to configure receive behavior to accept frames to the
specified random address during the time the frame exchange is pending
and such frames need to be acknowledged similarly to frames sent to the
local permanent address when this random address functionality is not
used.

Signed-off-by: vamsi krishna <vamsin@qti.qualcomm.com>
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Git-commit: ab5bb2d51ba8da4add4612b529968446cdb504b1
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next.git
CRs-Fixed: 1112321
Change-Id: I205d7b4da5bd31af951675aaa77ac1472b73e1f6
Signed-off-by: Vidyullatha Kanchanapally <vidyullatha@codeaurora.org>
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 4646cf5..67764fa 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -657,8 +657,25 @@
 			return err;
 	}
 
-	if (!ether_addr_equal(mgmt->sa, wdev_address(wdev)))
-		return -EINVAL;
+	if (!ether_addr_equal(mgmt->sa, wdev_address(wdev))) {
+		/* Allow random TA to be used with Public Action frames if the
+		 * driver has indicated support for this. Otherwise, only allow
+		 * the local address to be used.
+		 */
+		if (!ieee80211_is_action(mgmt->frame_control) ||
+		    mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
+			return -EINVAL;
+		if (!wdev->current_bss &&
+		    !wiphy_ext_feature_isset(
+			    &rdev->wiphy,
+			    NL80211_EXT_FEATURE_MGMT_TX_RANDOM_TA))
+			return -EINVAL;
+		if (wdev->current_bss &&
+		    !wiphy_ext_feature_isset(
+			    &rdev->wiphy,
+			    NL80211_EXT_FEATURE_MGMT_TX_RANDOM_TA_CONNECTED))
+			return -EINVAL;
+	}
 
 	/* Transmit the Action frame as requested by user space */
 	return rdev_mgmt_tx(rdev, wdev, params, cookie);