nl80211: Add driver events for radar detection

This patch is based on the original work by Boris Presman and
Victor Goldenshtein. Channel Switch Announcement support has been
removed and event handling as well as channel set handling was
changed, among various other changes.

Cc: Boris Presman <boris.presman@ti.com>
Cc: Victor Goldenshtein <victorg@ti.com>
Signed-hostap: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>

src/drivers/driver.h

@@ -3100,7 +3100,38 @@ enum wpa_event_type {
 	 * with the specified client (for example, max client reached, etc.) in
 	 * AP mode.
 	 */
-	EVENT_CONNECT_FAILED_REASON
+	EVENT_CONNECT_FAILED_REASON,
+
+	/**
+	 * EVENT_RADAR_DETECTED - Notify of radar detection
+	 *
+	 * A radar has been detected on the supplied frequency, hostapd should
+	 * react accordingly (e.g., change channel).
+	 */
+	EVENT_DFS_RADAR_DETECTED,
+
+	/**
+	 * EVENT_CAC_FINISHED - Notify that channel availability check has been completed
+	 *
+	 * After a successful CAC, the channel can be marked clear and used.
+	 */
+	EVENT_DFS_CAC_FINISHED,
+
+	/**
+	 * EVENT_CAC_ABORTED - Notify that channel availability check has been aborted
+	 *
+	 * The CAC was not successful, and the channel remains in the previous
+	 * state. This may happen due to a radar beeing detected or other
+	 * external influences.
+	 */
+	EVENT_DFS_CAC_ABORTED,
+
+	/**
+	 * EVENT_DFS_CAC_NOP_FINISHED - Notify that non-occupancy period is over
+	 *
+	 * The channel which was previously unavailable is now available again.
+	 */
+	EVENT_DFS_NOP_FINISHED
 };
 
 
@@ -3738,6 +3769,14 @@ union wpa_event_data {
 			BLOCKED_CLIENT
 		} code;
 	} connect_failed_reason;
+
+	/**
+	 * struct dfs_event - Data for radar detected events
+	 * @freq: Frequency of the channel in MHz
+	 */
+	struct dfs_event {
+		int freq;
+	} dfs_event;
 };
 
 /**

src/drivers/driver_common.c

@@ -80,6 +80,10 @@ const char * event_to_string(enum wpa_event_type event)
 	E2S(CH_SWITCH);
 	E2S(WNM);
 	E2S(CONNECT_FAILED_REASON);
+	E2S(DFS_RADAR_DETECTED);
+	E2S(DFS_CAC_FINISHED);
+	E2S(DFS_CAC_ABORTED);
+	E2S(DFS_NOP_FINISHED);
 	}
 
 	return "UNKNOWN";

src/drivers/driver_nl80211.c

@@ -2234,6 +2234,43 @@ static void nl80211_connect_failed_event(struct wpa_driver_nl80211_data *drv,
 }
 
 
+static void nl80211_radar_event(struct wpa_driver_nl80211_data *drv,
+				struct nlattr **tb)
+{
+	union wpa_event_data data;
+	enum nl80211_radar_event event_type;
+
+	if (!tb[NL80211_ATTR_WIPHY_FREQ] || !tb[NL80211_ATTR_RADAR_EVENT])
+		return;
+
+	os_memset(&data, 0, sizeof(data));
+	data.dfs_event.freq = nla_get_u16(tb[NL80211_ATTR_WIPHY_FREQ]);
+	event_type = nla_get_u8(tb[NL80211_ATTR_RADAR_EVENT]);
+
+	wpa_printf(MSG_DEBUG, "nl80211: DFS event on freq %d MHz",
+		   data.dfs_event.freq);
+
+	switch (event_type) {
+	case NL80211_RADAR_DETECTED:
+		wpa_supplicant_event(drv->ctx, EVENT_DFS_RADAR_DETECTED, &data);
+		break;
+	case NL80211_RADAR_CAC_FINISHED:
+		wpa_supplicant_event(drv->ctx, EVENT_DFS_CAC_FINISHED, &data);
+		break;
+	case NL80211_RADAR_CAC_ABORTED:
+		wpa_supplicant_event(drv->ctx, EVENT_DFS_CAC_ABORTED, &data);
+		break;
+	case NL80211_RADAR_NOP_FINISHED:
+		wpa_supplicant_event(drv->ctx, EVENT_DFS_NOP_FINISHED, &data);
+		break;
+	default:
+		wpa_printf(MSG_DEBUG, "nl80211: Unknown radar event %d "
+			   "received", event_type);
+		break;
+	}
+}
+
+
 static void nl80211_spurious_frame(struct i802_bss *bss, struct nlattr **tb,
 				   int wds)
 {
@@ -2378,6 +2415,9 @@ static void do_process_drv_event(struct i802_bss *bss, int cmd,
 	case NL80211_CMD_FT_EVENT:
 		mlme_event_ft_event(drv, tb);
 		break;
+	case NL80211_CMD_RADAR_DETECT:
+		nl80211_radar_event(drv, tb);
+		break;
 	default:
 		wpa_dbg(drv->ctx, MSG_DEBUG, "nl80211: Ignored unknown event "
 			"(cmd=%d)", cmd);