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.

2 files changed, 24 insertions, 0 deletions

diff --git a/sys/net80211/ieee80211.c b/sys/net80211/ieee80211.c
index 78c876e..49f8a8e 100644
--- a/sys/net80211/ieee80211.c
+++ b/sys/net80211/ieee80211.c
@@ -317,7 +317,11 @@ ieee80211_ifattach(struct ieee80211com *ic,
 
 	ifp->if_addrlen = IEEE80211_ADDR_LEN;
 	ifp->if_hdrlen = 0;
+
+	CURVNET_SET(vnet0);
+
 	if_attach(ifp);
+
 	ifp->if_mtu = IEEE80211_MTU_MAX;
 	ifp->if_broadcastaddr = ieee80211broadcastaddr;
 	ifp->if_output = null_output;
@@ -331,6 +335,8 @@ ieee80211_ifattach(struct ieee80211com *ic,
 	sdl->sdl_alen = IEEE80211_ADDR_LEN;
 	IEEE80211_ADDR_COPY(LLADDR(sdl), macaddr);
 	ifa_free(ifa);
+
+	CURVNET_RESTORE();
 }
 
 /*
@@ -345,8 +351,18 @@ ieee80211_ifdetach(struct ieee80211com *ic)
 	struct ifnet *ifp = ic->ic_ifp;
 	struct ieee80211vap *vap;
 
+	/*
+	 * This detaches the main interface, but not the vaps.
+	 * Each VAP may be in a separate VIMAGE.
+	 */
+	CURVNET_SET(ifp->if_vnet);
 	if_detach(ifp);
+	CURVNET_RESTORE();
 
+	/*
+	 * The VAP is responsible for setting and clearing
+	 * the VIMAGE context.
+	 */
 	while ((vap = TAILQ_FIRST(&ic->ic_vaps)) != NULL)
 		ieee80211_vap_destroy(vap);
 	ieee80211_waitfor_parent(ic);
@@ -365,7 +381,9 @@ ieee80211_ifdetach(struct ieee80211com *ic)
 	ieee80211_power_detach(ic);
 	ieee80211_node_detach(ic);
 
+	/* XXX VNET needed? */
 	ifmedia_removeall(&ic->ic_media);
+
 	taskqueue_free(ic->ic_tq);
 	IEEE80211_LOCK_DESTROY(ic);
 }
@@ -586,6 +604,8 @@ ieee80211_vap_detach(struct ieee80211vap *vap)
 	struct ieee80211com *ic = vap->iv_ic;
 	struct ifnet *ifp = vap->iv_ifp;
 
+	CURVNET_SET(ifp->if_vnet);
+
 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s parent %s\n",
 	    __func__, ieee80211_opmode_name[vap->iv_opmode],
 	    ic->ic_ifp->if_xname);
@@ -638,6 +658,8 @@ ieee80211_vap_detach(struct ieee80211vap *vap)
 	ieee80211_sysctl_vdetach(vap);
 
 	if_free(ifp);
+
+	CURVNET_RESTORE();
 }
 
 /*
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