nl80211: Add driver capability flag 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

@@ -866,6 +866,8 @@ struct wpa_driver_capa {
 #define WPA_DRIVER_FLAGS_OBSS_SCAN			0x04000000
 /* Driver supports IBSS (Ad-hoc) mode */
 #define WPA_DRIVER_FLAGS_IBSS				0x08000000
+/* Driver supports radar detection */
+#define WPA_DRIVER_FLAGS_RADAR				0x10000000
 	unsigned int flags;
 
 	int max_scan_ssids;

src/drivers/driver_nl80211.c

@@ -2680,6 +2680,7 @@ static int wiphy_info_iface_comb_process(struct wiphy_info_data *info,
 		[NL80211_IFACE_COMB_MAXNUM] = { .type = NLA_U32 },
 		[NL80211_IFACE_COMB_STA_AP_BI_MATCH] = { .type = NLA_FLAG },
 		[NL80211_IFACE_COMB_NUM_CHANNELS] = { .type = NLA_U32 },
+		[NL80211_IFACE_COMB_RADAR_DETECT_WIDTHS] = { .type = NLA_U32 },
 	},
 	iface_limit_policy[NUM_NL80211_IFACE_LIMIT] = {
 		[NL80211_IFACE_LIMIT_TYPES] = { .type = NLA_NESTED },
@@ -2693,6 +2694,9 @@ static int wiphy_info_iface_comb_process(struct wiphy_info_data *info,
 	    !tb_comb[NL80211_IFACE_COMB_NUM_CHANNELS])
 		return 0; /* broken combination */
 
+	if (tb_comb[NL80211_IFACE_COMB_RADAR_DETECT_WIDTHS])
+		info->capa->flags |= WPA_DRIVER_FLAGS_RADAR;
+
 	nla_for_each_nested(nl_limit, tb_comb[NL80211_IFACE_COMB_LIMITS],
 			    rem_limit) {
 		err = nla_parse_nested(tb_limit, MAX_NL80211_IFACE_LIMIT,