2008-12-12 15:08:44

by Jouni Malinen

[permalink] [raw]
Subject: [PATCH] mac80211: Send Layer 2 Update frame on reassociation

When a STA roams back to the same AP before the previous STA entry has
expired, a new STA entry is not added in mac80211. However, a Layer 2
Update frame still needs to be transmitted to update layer 2 devices
about the new location for the STA. Without this, switches may
continue to forward frames to the previous (now incorrect) port when
STA roams between APs.

Signed-off-by: Jouni Malinen <[email protected]>
---
net/mac80211/cfg.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

--- wireless-testing.orig/net/mac80211/cfg.c 2008-12-12 16:39:39.000000000 +0200
+++ wireless-testing/net/mac80211/cfg.c 2008-12-12 17:06:27.000000000 +0200
@@ -663,6 +663,7 @@ static int ieee80211_add_station(struct
struct sta_info *sta;
struct ieee80211_sub_if_data *sdata;
int err;
+ int layer2_update;

/* Prevent a race with changing the rate control algorithm */
if (!netif_running(dev))
@@ -693,17 +694,25 @@ static int ieee80211_add_station(struct

rate_control_rate_init(sta);

+ layer2_update = sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
+ sdata->vif.type == NL80211_IFTYPE_AP;
+
rcu_read_lock();

err = sta_info_insert(sta);
if (err) {
/* STA has been freed */
+ if (err == -EEXIST && layer2_update) {
+ /* Need to update layer 2 devices on reassociation */
+ sta = sta_info_get(local, mac);
+ if (sta)
+ ieee80211_send_layer2_update(sta);
+ }
rcu_read_unlock();
return err;
}

- if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
- sdata->vif.type == NL80211_IFTYPE_AP)
+ if (layer2_update)
ieee80211_send_layer2_update(sta);

rcu_read_unlock();

--
Jouni Malinen PGP id EFC895FA