mac80211: only set CSA beacon when at least one beacon must be transmitted
A beacon should never have a Channel Switch Announcement information
element with a count of 0, because a count of 1 means switch just
before the next beacon. So, if a count of 0 was valid in a beacon, it
would have been transmitted in the next channel already, which is
useless. A CSA count equal to zero is only meaningful in action
frames or probe_responses.
Fix the ieee80211_csa_is_complete() and ieee80211_update_csa()
functions accordingly.
With a CSA count of 0, we won't transmit any CSA beacons, because the
switch will happen before the next TBTT. To avoid extra work and
potential confusion in the drivers, complete the CSA immediately,
instead of waiting for the driver to call ieee80211_csa_finish().
To keep things simpler, we also switch immediately when the CSA count
is 1, while in theory we should delay the switch until just before the
next TBTT.
Additionally, move the ieee80211_csa_finish() function to cfg.c,
where it makes more sense.
Tested-by: Simon Wunderlich <sw@simonwunderlich.de>
Acked-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index b421993..b02ac33 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -1066,7 +1066,8 @@
/* Remove the CSA and MCSP elements from the beacon */
tmp_csa_settings = rcu_dereference(ifmsh->csa);
rcu_assign_pointer(ifmsh->csa, NULL);
- kfree_rcu(tmp_csa_settings, rcu_head);
+ if (tmp_csa_settings)
+ kfree_rcu(tmp_csa_settings, rcu_head);
ret = ieee80211_mesh_rebuild_beacon(sdata);
if (ret)
return -EINVAL;
@@ -1079,8 +1080,7 @@
}
int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata,
- struct cfg80211_csa_settings *csa_settings,
- bool csa_action)
+ struct cfg80211_csa_settings *csa_settings)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_csa_settings *tmp_csa_settings;
@@ -1104,9 +1104,6 @@
return ret;
}
- if (csa_action)
- ieee80211_send_action_csa(sdata, csa_settings);
-
return BSS_CHANGED_BEACON;
}