Fix up some initial issues with creation and deletion of hotplugged

net80211 devices and vaps.

* vnet sets vnet0 during kldload and device probe/attach, but not for
  the hotplug event.  Thus, plugging in a NIC causes things to panic.
  So, add a CURVNET_SET(vnet0) for now during the attach phase, until
  the hotplug code is taught to set CURVNET_SET(vnet0).

* there's also no implied detach vnet context - so teach the detach
  path about ifp->if_vnet.

* When creating/deleting vaps, also set the vnet context appropriately.
  These can be done at any time.

Now, the problems!

* ieee80211.c is supposed to be OS-portable code, with no OS-specific stuff
  like vnet. That should be fixed.

* When the device hotplug code gets taught about CURVNET_SET(vnet0), the
  device vnet set can go away; but the VAP vnet set still needs to be there.

* .. and there still is the question about potentially adding an implied
  CURVNET_SET(ifp->if_vnet) on if_free(), since any/all devices may end up
  being detached by a hotplug event in today's world.  That's going to be
  a topic of a subsequent commit.

1 files changed, 2 insertions, 0 deletions

diff --git a/sys/net80211/ieee80211_freebsd.c b/sys/net80211/ieee80211_freebsd.c
index bf4acee..e307e9d 100644
--- a/sys/net80211/ieee80211_freebsd.c
+++ b/sys/net80211/ieee80211_freebsd.c
@@ -152,7 +152,9 @@ wlan_clone_destroy(struct ifnet *ifp)
 void
 ieee80211_vap_destroy(struct ieee80211vap *vap)
 {
+	CURVNET_SET(vap->iv_ifp->if_vnet);
 	if_clone_destroyif(wlan_cloner, vap->iv_ifp);
+	CURVNET_RESTORE();
 }
 
 int