mac80211-hwsim: Add HWSIM_CMD_GET_RADIO command

HWSIM_CMD_GET_RADIO returns information about a specific radio id or
all of them in response to a dump. Create the netlink skb or use the
one provided by the dump functionality. Use the existing attribute
appending function to fill in the same attributes when creating a
new hwsim radio.

Save alpha2 and struct ieee80211_regdomain in the hwsim data or else
they will be lost in the depths of regulatory infrastructure.

Signed-off-by: Patrik Flykt <patrik.flykt@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/mac80211_hwsim.h

@@ -69,6 +69,8 @@ enum hwsim_tx_control_flags {
  *	returns the radio ID (>= 0) or negative on errors, if successful
  *	then multicast the result
  * @HWSIM_CMD_DEL_RADIO: destroy a radio, reply is multicasted
+ * @HWSIM_CMD_GET_RADIO: fetch information about existing radios, uses:
+ *	%HWSIM_ATTR_RADIO_ID
  * @__HWSIM_CMD_MAX: enum limit
  */
 enum {
@@ -78,6 +80,7 @@ enum {
 	HWSIM_CMD_TX_INFO_FRAME,
 	HWSIM_CMD_NEW_RADIO,
 	HWSIM_CMD_DEL_RADIO,
+	HWSIM_CMD_GET_RADIO,
 	__HWSIM_CMD_MAX,
 };
 #define HWSIM_CMD_MAX (_HWSIM_CMD_MAX - 1)