mac80211: process the CSA frame for mesh accordingly

Process the CSA frame according to the procedures define in IEEE Std
802.11-2012 section 10.9.8.4.3 as follow:
* The mesh channel switch parameters element (MCSP) must be availabe.
* If the MCSP's TTL is 1, drop the frame but still process the CSA.
* If the MCSP's precedence value is less than or equal to the current
  precedence value, drop the frame and do not process the CSA.
* The CSA frame is forwarded after TTL is decremented by 1 and the
  initiator field is set to 0. Transmit restrict field and others
  are maintained as is.
* No beacon or probe response frame are handled here.

Also, introduce the debug message used for mesh CSA purpose.

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig
index dc31ec3db404..97b5dcad5025 100644
--- a/net/mac80211/Kconfig
+++ b/net/mac80211/Kconfig
@@ -259,6 +259,17 @@ config MAC80211_MESH_SYNC_DEBUG
 
           Do not select this option.
 
+config MAC80211_MESH_CSA_DEBUG
+        bool "Verbose mesh channel switch debugging"
+        depends on MAC80211_DEBUG_MENU
+        depends on MAC80211_MESH
+        ---help---
+          Selecting this option causes mac80211 to print out very verbose mesh
+          channel switch debugging messages (when mac80211 is taking part in a
+          mesh network).
+
+          Do not select this option.
+
 config MAC80211_MESH_PS_DEBUG
         bool "Verbose mesh powersave debugging"
         depends on MAC80211_DEBUG_MENU