unblock wlan before starting networking

package/base-files/src/etc/network/if-pre-up.d/04-wireless

@@ -8,6 +8,8 @@ set -e
 [ "$IF_WIRELESS_HWMODE" ] || IF_WIRELESS_HWMODE=g
 [ "$IF_WIRELESS_EXTENSION" ] || IF_WIRELESS_EXTENSION=0
 
+rfkill unblock wlan 2>/dev/null
+
 wpa=0
 wpa1=0
 wpa2=0

package/busybox/config/miscutils/Config.in

@@ -547,6 +547,17 @@ config BUSYBOX_READAHEAD
 	  As readahead(2) blocks until each file has been read, it is best to
 	  run this applet as a background job.
 
+config BUSYBOX_RFKILL
+        bool "rfkill"
+        default y  # doesn't build on Ubuntu 9.04
+        help
+          Enable/disable wireless devices.
+
+          rfkill list : list all wireless devices
+          rfkill list bluetooth : list all bluetooth devices
+          rfkill list 1 : list device corresponding to the given index
+          rfkill block|unblock wlan : block/unblock all wlan(wifi) devices
+
 config BUSYBOX_RUNLEVEL
 	bool "runlevel"
 	default n