Hacking the Netgear wgt634u

Abstract: This paper gives you some hints about how to compile click ( http://pdos.csail.mit.edu/click/ ) and madwifi.stripped driver (http://pdos.csail.mit.edu/~jbicket/madwifi.stripped/) using openwrt ( http://openwrt.org ) for the Netgear wgt634u router. General information about the router you can find at http://pdos.csail.mit.edu/roofnet/doku.php?id=wgt634u.

Credits: http://pdos.csail.mit.edu/roofnet/

OpenWRT setup

First of all you need to install the openwrt toolchain on your build computer. Please follow the instructions given at http://openwrt.org/OpenWrtDocs/Installing.

Compiling click

To build click you have to copy the following Makefile (click.mk) to the $OPENWRT/buildroot/make directory:

 #############################################################
 #
 # click
 #
 #############################################################
 CLICK_DIR:=$(BUILD_DIR)/click
 
 click-source: $(CLICK_DIR)/.unpacked
 
 
 $(CLICK_DIR)/.unpacked: $(DL_DIR)/$(CLICK_SOURCE)
       (cd $(BUILD_DIR); \
       svn co svn://merkur.sardmn.informatik.hu-berlin.de/click)
       touch $(CLICK_DIR)/.unpacked
 
 
 $(CLICK_DIR)/.configured: $(CLICK_DIR)/.unpacked
       (cd $(CLICK_DIR); rm -rf config.cache; \
               $(TARGET_CONFIGURE_OPTS) \
               CFLAGS="$(TARGET_CFLAGS)" \
               AR_CREATEFLAGS="cru" \
               CLFLAGS=-static \
               CXXFLAGS=-static \
               ./configure \
               --build=i686-pc-linux-gnu \
               --host=mipsel-linux \
               --disable-linuxmodule \
               --enable-brn \
               --disable-ip \
               --enable-wifi \
               --disable-ip \
               --enable-tools=mixed \
       );
       touch  $(CLICK_DIR)/.configured
 
 $(CLICK_DIR)/click: $(CLICK_DIR)/.configured
       $(MAKE) CC=$(TARGET_CC) -C $(CLICK_DIR)
 
 $(TARGET_DIR)/usr/bin/click: $(CLICK_DIR)/click
       install -c $(CLICK_DIR)/userlevel/click $(TARGET_DIR)/usr/bin/click
       $(STRIP) $(TARGET_DIR)/usr/bin/click > /dev/null 2>&1
 
 click: uclibc $(TARGET_DIR)/usr/bin/click 
 
 click-clean: 
       $(MAKE) -C $(CLICK_DIR) clean
       rm -rf $(TARGET_DIR)/usr/bin/click
 
 click-dirclean: 
       rm -rf $(CLICK_DIR)

That's all: run make click to build click. Currently, I only tested the userlevel click binary.

Compiling Madwifi.stripped

The madwifi.stripped driver lets Click directly read and write raw frames from the wireless card, and strips out the usual driver logic. To build the madwifi.stripped driver you have to copy the following Makefile (madwifi.mk) to the $OPENWRT/buildroot/make directory:

 #############################################################
 #
 # madwifi.stripped
 #
 #############################################################
 MADWIFI_DIR:=$(BUILD_DIR)/madwifi
 
 
 $(DL_DIR)/$(MADWIFI_SOURCE):
       $(WGET) -P $(DL_DIR) $(MADWIFI_SITE)/$(MADWIFI_SOURCE)
 
 madwifi-source: $(DL_DIR)/$(MADWIFI_SOURCE)
 
 $(MADWIFI_DIR)/.unpacked: $(DL_DIR)/$(MADWIFI_SOURCE)
       (cd $(BUILD_DIR); \
       cvs -d :pserver:anoncvs@cvs.pdos.lcs.mit.edu:/cvs login)
       (cd $(BUILD_DIR); \
       cvs -z5 -d :pserver:anoncvs@cvs.pdos.lcs.mit.edu:/cvs co -d madwifi roofnet/release/stripped)
       touch $(MADWIFI_DIR)/.unpacked
 
 $(MADWIFI_DIR)/madwifi: $(MADWIFI_DIR)/.unpacked
       $(MAKE) CC=$(TARGET_CC) TARGET=mips-le-elf KERNELPATH=$(BUILD_DIR)/WRT54GS/release/src/linux/linux/ -C $(MADWIFI_DIR)
 
 $(TARGET_DIR)/usr/bin/madwifi: $(MADWIFI_DIR)/madwifi
       mkdir $(TARGET_DIR)/usr/bin/madwifi/
       cp $(MADWIFI_DIR)/madwifi/driver/ath_pci.o $(TARGET_DIR)/usr/bin/madwifi/
       cp $(MADWIFI_DIR)/madwifi/ath_hal/ath_hal.o $(TARGET_DIR)/usr/bin/madwifi/
       $(STRIP) $(TARGET_DIR)/usr/bin/madwifi/ath_pci.o > /dev/null 2>&1
       $(STRIP) $(TARGET_DIR)/usr/bin/madwifi/ath_hal.o > /dev/null 2>&1
 
 madwifi: uclibc $(TARGET_DIR)/usr/bin/madwifi/
 
 madwifi-clean: 
       $(MAKE) -C $(MADWIFI_DIR) clean
       rm -rf $(TARGET_DIR)/usr/bin/madwifi/
 
 madwifi-dirclean: 
       rm -rf $(MADWIFI_DIR)

That's all: run make madwifi to build the driver.