cfg80211: fix reporting 5/10 MHz support to user space

nla_put_flag needs a real nl80211 attribute id, not a wiphy flag bit.
While at it, split 5 and 10 MHz capability flags in case we ever need
to support hardware that can only do one of the two.

Also move the flag settings to the split-only information so we don't
increase the space needed for old userspace.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
[change location of flag setting]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/uapi/linux/nl80211.h

@@ -1515,6 +1515,11 @@ enum nl80211_commands {
  *	to react to radar events, e.g. initiate a channel switch or leave the
  *	IBSS network.
  *
+ * @NL80211_ATTR_SUPPORT_5_MHZ: A flag indicating that the device supports
+ *	5 MHz channel bandwidth.
+ * @NL80211_ATTR_SUPPORT_10_MHZ: A flag indicating that the device supports
+ *	10 MHz channel bandwidth.
+ *
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
  */
@@ -1831,6 +1836,9 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_HANDLE_DFS,
 
+	NL80211_ATTR_SUPPORT_5_MHZ,
+	NL80211_ATTR_SUPPORT_10_MHZ,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,

net/wireless/nl80211.c

@@ -1228,10 +1228,6 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
 		if ((dev->wiphy.flags & WIPHY_FLAG_TDLS_EXTERNAL_SETUP) &&
 		    nla_put_flag(msg, NL80211_ATTR_TDLS_EXTERNAL_SETUP))
 			goto nla_put_failure;
-		if ((dev->wiphy.flags & WIPHY_FLAG_SUPPORTS_5_10_MHZ) &&
-		    nla_put_flag(msg, WIPHY_FLAG_SUPPORTS_5_10_MHZ))
-			goto nla_put_failure;
-
 		state->split_start++;
 		if (state->split)
 			break;
@@ -1560,6 +1556,11 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
 		if (nl80211_send_coalesce(msg, dev))
 			goto nla_put_failure;
 
+		if ((dev->wiphy.flags & WIPHY_FLAG_SUPPORTS_5_10_MHZ) &&
+		    (nla_put_flag(msg, NL80211_ATTR_SUPPORT_5_MHZ) ||
+		     nla_put_flag(msg, NL80211_ATTR_SUPPORT_10_MHZ)))
+			goto nla_put_failure;
+
 		/* done */
 		state->split_start = 0;
 		break;