[PATCH] DFS: enter DFS state if no available channel is found

[David Bauer]

Previously hostapd would not stop transmitting when a DFS event was
detected and no available channel to switch to was available.

Disable and re-enable the interface to enter DFS state. This way, TX
does not happen until the kernel notifies hostapd about the NOP
expiring.

Signed-off-by: David Bauer <mail at david-bauer.net>
---
 src/ap/dfs.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/ap/dfs.c b/src/ap/dfs.c
index 3c078b9cb..9dddca338 100644
--- a/src/ap/dfs.c
+++ b/src/ap/dfs.c
@@ -1066,8 +1066,16 @@ static int hostapd_dfs_start_channel_switch(struct hostapd_iface *iface)
 						  &oper_centr_freq_seg0_idx,
 						  &oper_centr_freq_seg1_idx,
 						  &skip_radar);
-		if (!channel)
-			return err;
+		if (!channel) {
+			/*
+			 * Toggle interface state to enter DFS state
+			 * until NOP is finished.
+			 */
+			hostapd_disable_iface(iface);
+			hostapd_enable_iface(iface);
+			return 0;
+		}
+
 		if (!skip_radar) {
 			iface->freq = channel->freq;
 			iface->conf->channel = channel->chan;
-- 
2.27.0