nl80211: Indicate channel list change events

Listen to regulatory event messages from kernel and convert them to
internal driver event notifications indicated that the channel list
may have changed.

src/drivers/driver_nl80211.c

@@ -1305,6 +1305,16 @@ static int process_event(struct nl_msg *msg, void *arg)
 	case NL80211_CMD_NOTIFY_CQM:
 		nl80211_cqm_event(drv, tb);
 		break;
+	case NL80211_CMD_REG_CHANGE:
+		wpa_printf(MSG_DEBUG, "nl80211: Regulatory domain change");
+		wpa_supplicant_event(drv->ctx, EVENT_CHANNEL_LIST_CHANGED,
+				     NULL);
+		break;
+	case NL80211_CMD_REG_BEACON_HINT:
+		wpa_printf(MSG_DEBUG, "nl80211: Regulatory beacon hint");
+		wpa_supplicant_event(drv->ctx, EVENT_CHANNEL_LIST_CHANGED,
+				     NULL);
+		break;
 	default:
 		wpa_printf(MSG_DEBUG, "nl80211: Ignored unknown event "
 			   "(cmd=%d)", gnlh->cmd);
@@ -1578,6 +1588,16 @@ static int wpa_driver_nl80211_init_nl(struct wpa_driver_nl80211_data *drv)
 		goto err4;
 	}
 
+	ret = nl_get_multicast_id(drv, "nl80211", "regulatory");
+	if (ret >= 0)
+		ret = nl_socket_add_membership(drv->nl_handle_event, ret);
+	if (ret < 0) {
+		wpa_printf(MSG_DEBUG, "nl80211: Could not add multicast "
+			   "membership for regulatory events: %d (%s)",
+			   ret, strerror(-ret));
+		/* Continue without regulatory events */
+	}
+
 	eloop_register_read_sock(nl_socket_get_fd(drv->nl_handle_event),
 				 wpa_driver_nl80211_event_receive, drv,
 				 drv->nl_handle_event);