mac80211: do not scan and monitor connection in parallel
Before we send probes in connection monitoring we check if scan is not
pending. But we do that check without locking. Fix that and also do not
start scan if connection monitoring is in progress.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4be11ea..1fd8cb2 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1260,6 +1260,7 @@
int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
struct cfg80211_scan_request *req);
void ieee80211_scan_cancel(struct ieee80211_local *local);
+void ieee80211_run_deferred_scan(struct ieee80211_local *local);
ieee80211_rx_result
ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index bbf1100..c8836fa 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1447,19 +1447,24 @@
static void ieee80211_reset_ap_probe(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+ struct ieee80211_local *local = sdata->local;
+ mutex_lock(&local->mtx);
if (!(ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
- IEEE80211_STA_CONNECTION_POLL)))
- return;
+ IEEE80211_STA_CONNECTION_POLL))) {
+ mutex_unlock(&local->mtx);
+ return;
+ }
ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
IEEE80211_STA_BEACON_POLL);
- mutex_lock(&sdata->local->iflist_mtx);
- ieee80211_recalc_ps(sdata->local, -1);
- mutex_unlock(&sdata->local->iflist_mtx);
+
+ mutex_lock(&local->iflist_mtx);
+ ieee80211_recalc_ps(local, -1);
+ mutex_unlock(&local->iflist_mtx);
if (sdata->local->hw.flags & IEEE80211_HW_CONNECTION_MONITOR)
- return;
+ goto out;
/*
* We've received a probe response, but are not sure whether
@@ -1471,6 +1476,9 @@
mod_timer(&ifmgd->conn_mon_timer,
round_jiffies_up(jiffies +
IEEE80211_CONNECTION_IDLE_TIME));
+out:
+ ieee80211_run_deferred_scan(local);
+ mutex_unlock(&local->mtx);
}
void ieee80211_sta_tx_notify(struct ieee80211_sub_if_data *sdata,
@@ -1546,17 +1554,18 @@
if (!ieee80211_sdata_running(sdata))
return;
- if (sdata->local->scanning)
- return;
-
- if (sdata->local->tmp_channel)
- return;
-
mutex_lock(&ifmgd->mtx);
if (!ifmgd->associated)
goto out;
+ mutex_lock(&sdata->local->mtx);
+
+ if (sdata->local->tmp_channel || sdata->local->scanning) {
+ mutex_unlock(&sdata->local->mtx);
+ goto out;
+ }
+
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
if (beacon && net_ratelimit())
printk(KERN_DEBUG "%s: detected beacon loss from AP "
@@ -1583,6 +1592,8 @@
else
ifmgd->flags |= IEEE80211_STA_CONNECTION_POLL;
+ mutex_unlock(&sdata->local->mtx);
+
if (already)
goto out;
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index c70e176..5617593 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -387,6 +387,33 @@
return 0;
}
+static bool ieee80211_can_scan(struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata)
+{
+ if (!list_empty(&local->work_list))
+ return false;
+
+ if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+ sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL |
+ IEEE80211_STA_CONNECTION_POLL))
+ return false;
+
+ return true;
+}
+
+void ieee80211_run_deferred_scan(struct ieee80211_local *local)
+{
+ lockdep_assert_held(&local->mtx);
+
+ if (!local->scan_req || local->scanning)
+ return;
+
+ if (!ieee80211_can_scan(local, local->scan_sdata))
+ return;
+
+ ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
+ round_jiffies_relative(0));
+}
static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
struct cfg80211_scan_request *req)
@@ -399,7 +426,7 @@
if (local->scan_req)
return -EBUSY;
- if (!list_empty(&local->work_list)) {
+ if (!ieee80211_can_scan(local, sdata)) {
/* wait for the work to finish/time out */
local->scan_req = req;
local->scan_sdata = sdata;
diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index c6e230e..1f74af3 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -226,13 +226,8 @@
run_again(local, jiffies + HZ/2);
}
- if (list_empty(&local->work_list) && local->scan_req &&
- !local->scanning)
- ieee80211_queue_delayed_work(&local->hw,
- &local->scan_work,
- round_jiffies_relative(0));
-
ieee80211_recalc_idle(local);
+ ieee80211_run_deferred_scan(local);
mutex_unlock(&local->mtx);