[Click] Problem in install the linux kernel level

[me you]

Hi click team...

I want to configure the click router as linux kernel level,but having some error.
I am using the debain with kerenl 2.6.18-6-686.
The error as below.

/usr/include/linux/sysctl.h:912: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:913: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:917: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:917: error: ‘loff_t’ has not been declared
/usr/include/linux/sysctl.h:920: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:920: error: ‘loff_t’ has not been declared
/usr/include/linux/sysctl.h:922: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:922: error: ‘loff_t’ has not been declared
/usr/include/linux/sysctl.h:924: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:924: error: ‘loff_t’ has not been declared
/usr/include/linux/sysctl.h:926: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:926: error: ‘loff_t’ has not been declared
/usr/include/linux/sysctl.h:928: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:928: error: ‘loff_t’ has not been declared
/usr/include/linux/sysctl.h:930: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:930: error: ‘loff_t’ has not been declared
/usr/include/linux/sysctl.h:932: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:932: error: ‘loff_t’ has not been declared
/usr/include/linux/sysctl.h:934: error: ‘size_t’ has not been declared
/usr/include/linux/sysctl.h:934: error: ‘loff_t’ has not been declared

Is that error is due to kernel of patching the kernel....Please reply f some body knows...
thanks