mac80211_hwsim: support scanning with random MAC address

This adds support for scanning with random MAC address for
both software and hardware scan.

Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 6daaad5..c2303db 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -422,6 +422,7 @@
 	struct cfg80211_scan_request *hw_scan_request;
 	struct ieee80211_vif *hw_scan_vif;
 	int scan_chan_idx;
+	u8 scan_addr[ETH_ALEN];
 
 	struct ieee80211_channel *channel;
 	u64 beacon_int	/* beacon interval in us */;
@@ -830,6 +831,9 @@
 		.ret = false,
 	};
 
+	if (data->scanning && memcmp(addr, data->scan_addr, ETH_ALEN) == 0)
+		return true;
+
 	memcpy(md.addr, addr, ETH_ALEN);
 
 	ieee80211_iterate_active_interfaces_atomic(data->hw,
@@ -1802,7 +1806,7 @@
 			struct sk_buff *probe;
 
 			probe = ieee80211_probereq_get(hwsim->hw,
-						       hwsim->hw_scan_vif->addr,
+						       hwsim->scan_addr,
 						       req->ssids[i].ssid,
 						       req->ssids[i].ssid_len,
 						       req->ie_len);
@@ -1840,6 +1844,12 @@
 	hwsim->hw_scan_request = req;
 	hwsim->hw_scan_vif = vif;
 	hwsim->scan_chan_idx = 0;
+	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
+		get_random_mask_addr(hwsim->scan_addr,
+				     hw_req->req.mac_addr,
+				     hw_req->req.mac_addr_mask);
+	else
+		memcpy(hwsim->scan_addr, vif->addr, ETH_ALEN);
 	mutex_unlock(&hwsim->mutex);
 
 	wiphy_debug(hw->wiphy, "hwsim hw_scan request\n");
@@ -1880,6 +1890,8 @@
 	}
 
 	printk(KERN_DEBUG "hwsim sw_scan request, prepping stuff\n");
+
+	memcpy(hwsim->scan_addr, mac_addr, ETH_ALEN);
 	hwsim->scanning = true;
 
 out:
@@ -1895,6 +1907,7 @@
 
 	printk(KERN_DEBUG "hwsim sw_scan_complete\n");
 	hwsim->scanning = false;
+	memset(hwsim->scan_addr, 0, ETH_ALEN);
 
 	mutex_unlock(&hwsim->mutex);
 }
@@ -2320,7 +2333,8 @@
 	hw->wiphy->features |= NL80211_FEATURE_ACTIVE_MONITOR |
 			       NL80211_FEATURE_AP_MODE_CHAN_WIDTH_CHANGE |
 			       NL80211_FEATURE_STATIC_SMPS |
-			       NL80211_FEATURE_DYNAMIC_SMPS;
+			       NL80211_FEATURE_DYNAMIC_SMPS |
+			       NL80211_FEATURE_SCAN_RANDOM_MAC_ADDR;
 
 	/* ask mac80211 to reserve space for magic */
 	hw->vif_data_size = sizeof(struct hwsim_vif_priv);