Error in building TUX module.

Hi,

I need to change the source code of TUX and then rebuild TUX as
a kernel module.

But when I go to "/usr/src/linux-2.4.9-31/net/tux" and use Makefile
to rebuild tux.o file, First I encounter an error:

Rules.make not found

Then I sepcify TOPDIR in the Makefile and build TUX again, this time
I got a different error as follows:

make[1]: Entering directory `/usr/src/linux-2.4.9-31/net/tux'
cc    -c -o accept.o accept.c
accept.c:9:21: net/tux.h: No such file or directory
make[1]: *** [accept.o] Error 1
make[1]: Leaving directory `/usr/src/linux-2.4.9-31/net/tux'
make: *** [first_rule] Error 2c:9:21: net/tux.h: No such file or directory

I found Linux kernel can build TUX module correctly when I rebuild
Linux kernel successfully. So maybe something wrong with the TUX Makefile
configuration when I use it seperately,but I don't know the reason.

Can you give me a solution?

Thank you.

Liang