cfg80211: add P2P Device abstraction

In order to support using a different MAC address
for the P2P Device address we must first have a
P2P Device abstraction that can be assigned a MAC
address.

This abstraction will also be useful to support
offloading P2P operations to the device, e.g.
periodic listen for discoverability.

Currently, the driver is responsible for assigning
a MAC address to the P2P Device, but this could be
changed by allowing a MAC address to be given to
the NEW_INTERFACE command.

As it has no associated netdev, a P2P Device can
only be identified by its wdev identifier but the
previous patches allowed using the wdev identifier
in various APIs, e.g. remain-on-channel.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/util.c b/net/wireless/util.c
index ce393dd..d7b6722 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -800,6 +800,10 @@
 	if (otype == NL80211_IFTYPE_AP_VLAN)
 		return -EOPNOTSUPP;
 
+	/* cannot change into P2P device type */
+	if (ntype == NL80211_IFTYPE_P2P_DEVICE)
+		return -EOPNOTSUPP;
+
 	if (!rdev->ops->change_virtual_intf ||
 	    !(rdev->wiphy.interface_modes & (1 << ntype)))
 		return -EOPNOTSUPP;
@@ -877,6 +881,9 @@
 		case NUM_NL80211_IFTYPES:
 			/* not happening */
 			break;
+		case NL80211_IFTYPE_P2P_DEVICE:
+			WARN_ON(1);
+			break;
 		}
 	}
 
@@ -1041,8 +1048,15 @@
 	list_for_each_entry(wdev_iter, &rdev->wdev_list, list) {
 		if (wdev_iter == wdev)
 			continue;
-		if (!netif_running(wdev_iter->netdev))
-			continue;
+		if (wdev_iter->netdev) {
+			if (!netif_running(wdev_iter->netdev))
+				continue;
+		} else if (wdev_iter->iftype == NL80211_IFTYPE_P2P_DEVICE) {
+			if (!wdev_iter->p2p_started)
+				continue;
+		} else {
+			WARN_ON(1);
+		}
 
 		if (rdev->wiphy.software_iftypes & BIT(wdev_iter->iftype))
 			continue;