mac80211: add explicit monitor interface if needed

The queue mapping redesign that I'm planning to do
will break pure injection unless we handle monitor
interfaces explicitly. One possible option would
be to have the driver tell mac80211 about monitor
mode queues etc., but that would duplicate the API
since we already need to have queue assignments
handled per virtual interface.

So in order to solve this, have a virtual monitor
interface that is added whenever all active vifs
are monitors. We could also use the state of one
of the monitor interfaces, but managing that would
be complicated, so allocate separate state.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 4109ec7999a3..a8d0188ab408 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1283,8 +1283,11 @@ static bool __ieee80211_tx(struct ieee80211_local *local,
 
         switch (sdata->vif.type) {
         case NL80211_IFTYPE_MONITOR:
-                sdata = NULL;
-                vif = NULL;
+                sdata = rcu_dereference(local->monitor_sdata);
+                if (sdata)
+                        vif = &sdata->vif;
+                else
+                        vif = NULL;
                 break;
         case NL80211_IFTYPE_AP_VLAN:
                 sdata = container_of(sdata->bss,