From 4e39ccac0d678eacb5dd6ffc5057531af33c12d6 Mon Sep 17 00:00:00 2001 From: Antonio Quartulli Date: Sat, 21 Nov 2015 18:13:40 +0800 Subject: [PATCH] mac80211: do not actively scan DFS channels DFS channels should not be actively scanned as we can't be sure if we are allowed or not. If the current channel is in the DFS band, active scan might be performed after CSA, but we have no guarantee about other channels, therefore it is safer to prevent active scanning at all. Cc: stable@vger.kernel.org Signed-off-by: Antonio Quartulli Signed-off-by: Johannes Berg --- net/mac80211/scan.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 4aeca4b0c3cb..a413e52f7691 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -597,8 +597,8 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, /* We need to ensure power level is at max for scanning. */ ieee80211_hw_config(local, 0); - if ((req->channels[0]->flags & - IEEE80211_CHAN_NO_IR) || + if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR | + IEEE80211_CHAN_RADAR)) || !req->n_ssids) { next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; } else { @@ -645,7 +645,7 @@ ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) * TODO: channel switching also consumes quite some time, * add that delay as well to get a better estimation */ - if (chan->flags & IEEE80211_CHAN_NO_IR) + if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) return IEEE80211_PASSIVE_CHANNEL_TIME; return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; } @@ -777,7 +777,8 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, * * In any case, it is not necessary for a passive scan. */ - if (chan->flags & IEEE80211_CHAN_NO_IR || !scan_req->n_ssids) { + if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) || + !scan_req->n_ssids) { *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; local->next_scan_state = SCAN_DECISION; return; -- 2.34.1