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, 20 insertions, 0 deletions

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 7c1e1ebc0e23..8c3b26a21574 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -697,6 +697,18 @@ struct ieee80211_sec_chan_offs_ie {
 } __packed;
 
 /**
+ * struct ieee80211_mesh_chansw_params_ie - mesh channel switch parameters IE
+ *
+ * This structure represents the "Mesh Channel Switch Paramters element"
+ */
+struct ieee80211_mesh_chansw_params_ie {
+        u8 mesh_ttl;
+        u8 mesh_flags;
+        __le16 mesh_reason;
+        __le16 mesh_pre_value;
+} __packed;
+
+/**
  * struct ieee80211_wide_bw_chansw_ie - wide bandwidth channel switch IE
  */
 struct ieee80211_wide_bw_chansw_ie {
@@ -751,6 +763,14 @@ enum mesh_config_capab_flags {
 };
 
 /**
+ * mesh channel switch parameters element's flag indicator
+ *
+ */
+#define WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT BIT(0)
+#define WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR BIT(1)
+#define WLAN_EID_CHAN_SWITCH_PARAM_REASON BIT(2)
+
+/**
  * struct ieee80211_rann_ie
  *
  * This structure refers to "Root Announcement information element"