nl80211: conditionally add back radar information

If userspace is updated to deal with large split wiphy
information dumps, add back the radar information that
could otherwise push the data over the limit of the
netlink dump messages.

Cc: Simon Wunderlich <simon.wunderlich@s2003.tu-chemnitz.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

@@ -540,7 +540,8 @@ static inline void *nl80211hdr_put(struct sk_buff *skb, u32 portid, u32 seq,
 }
 
 static int nl80211_msg_put_channel(struct sk_buff *msg,
-				   struct ieee80211_channel *chan)
+				   struct ieee80211_channel *chan,
+				   bool large)
 {
 	if (nla_put_u32(msg, NL80211_FREQUENCY_ATTR_FREQ,
 			chan->center_freq))
@@ -555,9 +556,22 @@ static int nl80211_msg_put_channel(struct sk_buff *msg,
 	if ((chan->flags & IEEE80211_CHAN_NO_IBSS) &&
 	    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_NO_IBSS))
 		goto nla_put_failure;
-	if ((chan->flags & IEEE80211_CHAN_RADAR) &&
-	    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_RADAR))
+	if (chan->flags & IEEE80211_CHAN_RADAR) {
+		if (nla_put_flag(msg, NL80211_FREQUENCY_ATTR_RADAR))
+			goto nla_put_failure;
+		if (large) {
+			u32 time;
+
+			time = elapsed_jiffies_msecs(chan->dfs_state_entered);
+
+			if (nla_put_u32(msg, NL80211_FREQUENCY_ATTR_DFS_STATE,
+					chan->dfs_state))
+				goto nla_put_failure;
+			if (nla_put_u32(msg, NL80211_FREQUENCY_ATTR_DFS_TIME,
+					time))
 				goto nla_put_failure;
+		}
+	}
 
 	if (nla_put_u32(msg, NL80211_FREQUENCY_ATTR_MAX_TX_POWER,
 			DBM_TO_MBM(chan->max_power)))
@@ -833,7 +847,8 @@ static int nl80211_put_iftypes(struct sk_buff *msg, u32 attr, u16 ifmodes)
 }
 
 static int nl80211_put_iface_combinations(struct wiphy *wiphy,
-					  struct sk_buff *msg)
+					  struct sk_buff *msg,
+					  bool large)
 {
 	struct nlattr *nl_combis;
 	int i, j;
@@ -882,6 +897,10 @@ static int nl80211_put_iface_combinations(struct wiphy *wiphy,
 		    nla_put_u32(msg, NL80211_IFACE_COMB_MAXNUM,
 				c->max_interfaces))
 			goto nla_put_failure;
+		if (large &&
+		    nla_put_u32(msg, NL80211_IFACE_COMB_RADAR_DETECT_WIDTHS,
+				c->radar_detect_widths))
+			goto nla_put_failure;
 
 		nla_nest_end(msg, nl_combi);
 	}
@@ -1231,7 +1250,8 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
 
 					chan = &sband->channels[i];
 
-					if (nl80211_msg_put_channel(msg, chan))
+					if (nl80211_msg_put_channel(msg, chan,
+								    split))
 						goto nla_put_failure;
 
 					nla_nest_end(msg, nl_freq);
@@ -1385,7 +1405,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
 					dev->wiphy.software_iftypes))
 			goto nla_put_failure;
 
-		if (nl80211_put_iface_combinations(&dev->wiphy, msg))
+		if (nl80211_put_iface_combinations(&dev->wiphy, msg, split))
 			goto nla_put_failure;
 
 		(*split_start)++;
@@ -9377,7 +9397,7 @@ void nl80211_send_beacon_hint_event(struct wiphy *wiphy,
 	nl_freq = nla_nest_start(msg, NL80211_ATTR_FREQ_BEFORE);
 	if (!nl_freq)
 		goto nla_put_failure;
-	if (nl80211_msg_put_channel(msg, channel_before))
+	if (nl80211_msg_put_channel(msg, channel_before, false))
 		goto nla_put_failure;
 	nla_nest_end(msg, nl_freq);
 
@@ -9385,7 +9405,7 @@ void nl80211_send_beacon_hint_event(struct wiphy *wiphy,
 	nl_freq = nla_nest_start(msg, NL80211_ATTR_FREQ_AFTER);
 	if (!nl_freq)
 		goto nla_put_failure;
-	if (nl80211_msg_put_channel(msg, channel_after))
+	if (nl80211_msg_put_channel(msg, channel_after, false))
 		goto nla_put_failure;
 	nla_nest_end(msg, nl_freq);