commit 11f78ac32b06648c1dde9371b70323168b51a83e
author Johannes Berg <johannes.berg@intel.com> Fri Nov 14 16:43:50 2014 +0100
committer Johannes Berg <johannes.berg@intel.com> Thu Jan 08 15:27:54 2015 +0100
tree 2cea75cf1a053308f980dc69ebc9e7e7cd7a59e6
parent 4ed20bebf51578229a1986efcf46344075ec8447

cfg80211: allow survey data to return global data

Not all devices are able to report survey data (particularly
time spent for various operations) per channel. As all these
statistics already exist in survey data, allow such devices
to report them (if userspace requested it)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 94ab201..9555ef9 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -6613,12 +6613,17 @@
 }
 
 static int nl80211_send_survey(struct sk_buff *msg, u32 portid, u32 seq,
-				int flags, struct net_device *dev,
-				struct survey_info *survey)
+			       int flags, struct net_device *dev,
+			       bool allow_radio_stats,
+			       struct survey_info *survey)
 {
 	void *hdr;
 	struct nlattr *infoattr;
 
+	/* skip radio stats if userspace didn't request them */
+	if (!survey->channel && !allow_radio_stats)
+		return 0;
+
 	hdr = nl80211hdr_put(msg, portid, seq, flags,
 			     NL80211_CMD_NEW_SURVEY_RESULTS);
 	if (!hdr)
@@ -6631,7 +6636,8 @@
 	if (!infoattr)
 		goto nla_put_failure;
 
-	if (nla_put_u32(msg, NL80211_SURVEY_INFO_FREQUENCY,
+	if (survey->channel &&
+	    nla_put_u32(msg, NL80211_SURVEY_INFO_FREQUENCY,
 			survey->channel->center_freq))
 		goto nla_put_failure;
 
@@ -6671,19 +6677,22 @@
 	return -EMSGSIZE;
 }
 
-static int nl80211_dump_survey(struct sk_buff *skb,
-			struct netlink_callback *cb)
+static int nl80211_dump_survey(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct survey_info survey;
 	struct cfg80211_registered_device *rdev;
 	struct wireless_dev *wdev;
 	int survey_idx = cb->args[2];
 	int res;
+	bool radio_stats;
 
 	res = nl80211_prepare_wdev_dump(skb, cb, &rdev, &wdev);
 	if (res)
 		return res;
 
+	/* prepare_wdev_dump parsed the attributes */
+	radio_stats = nl80211_fam.attrbuf[NL80211_ATTR_SURVEY_RADIO_STATS];
+
 	if (!wdev->netdev) {
 		res = -EINVAL;
 		goto out_err;
@@ -6701,13 +6710,9 @@
 		if (res)
 			goto out_err;
 
-		/* Survey without a channel doesn't make sense */
-		if (!survey.channel) {
-			res = -EINVAL;
-			goto out;
-		}
-
-		if (survey.channel->flags & IEEE80211_CHAN_DISABLED) {
+		/* don't send disabled channels, but do send non-channel data */
+		if (survey.channel &&
+		    survey.channel->flags & IEEE80211_CHAN_DISABLED) {
 			survey_idx++;
 			continue;
 		}
@@ -6715,7 +6720,7 @@
 		if (nl80211_send_survey(skb,
 				NETLINK_CB(cb->skb).portid,
 				cb->nlh->nlmsg_seq, NLM_F_MULTI,
-				wdev->netdev, &survey) < 0)
+				wdev->netdev, radio_stats, &survey) < 0)
 			goto out;
 		survey_idx++;
 	}