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, 9 insertions, 0 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 65ebe0c5e835..523783cedf6e 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -740,6 +740,7 @@ u32 ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,
                 case WLAN_EID_TIMEOUT_INTERVAL:
                 case WLAN_EID_SECONDARY_CHANNEL_OFFSET:
                 case WLAN_EID_WIDE_BW_CHANNEL_SWITCH:
+                case WLAN_EID_CHAN_SWITCH_PARAM:
                 /*
                  * not listing WLAN_EID_CHANNEL_SWITCH_WRAPPER -- it seems possible
                  * that if the content gets bigger it might be needed more than once
@@ -905,6 +906,14 @@ u32 ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,
                         }
                         elems->sec_chan_offs = (void *)pos;
                         break;
+                case WLAN_EID_CHAN_SWITCH_PARAM:
+                        if (elen !=
+                            sizeof(*elems->mesh_chansw_params_ie)) {
+                                elem_parse_failed = true;
+                                break;
+                        }
+                        elems->mesh_chansw_params_ie = (void *)pos;
+                        break;
                 case WLAN_EID_WIDE_BW_CHANNEL_SWITCH:
                         if (!action ||
                             elen != sizeof(*elems->wide_bw_chansw_ie)) {