compiling on linux-2.6.24 kernel

Hi, friends

I am running CentOS-5 (kernel-2.6.24).
I am trying to compile the netfilter-rtpproxy.0.5.tgz. I have downloaded the file. Firing the make command in following directory, gives me following result.

# cd iptables-1.3.5/patch-o-matic/xt_RTPPROXY

# make all

cd linux-2.6/net/netfilter;make -C /usr/src/linux M=`pwd` modules;cd -
make[1]: Entering directory `/usr/src/kernels/2.6.18-164.11.1.el5-i686'
scripts/Makefile.build:17: /usr/src/downloaded/iptables-1.3.5/patch-o-matic/xt_RTPPROXY/linux-2.6/net/netfilter/Makefile: No such file or directory
make[2]: *** No rule to make target `/usr/src/downloaded/iptables-1.3.5/patch-o-matic/xt_RTPPROXY/linux-2.6/net/netfilter/Makefile'. Stop.
make[1]: *** [_module_/usr/src/downloaded/iptables-1.3.5/patch-o-matic/xt_RTPPROXY/linux-2.6/net/netfilter] Error 2
make[1]: Leaving directory `/usr/src/kernels/2.6.18-164.11.1.el5-i686'
/usr/src/downloaded/iptables-1.3.5/patch-o-matic/xt_RTPPROXY
gcc -O2 -Wall -Wunused -I linux-2.6/include -I iptables/include -DIPTABLES_VERSION=\"1.3.5\" -fPIC -o iptables/extensions/libipt_RTPPROXY.o -c iptables/extensions/libipt_RTPPROXY.c
iptables/extensions/libipt_RTPPROXY.c:29:23: error: ../config.h: No such file or directory
iptables/extensions/libipt_RTPPROXY.c: In function ‘help’:
iptables/extensions/libipt_RTPPROXY.c:44: error: ‘XTABLES_VERSION’ undeclared (first use in this function)
iptables/extensions/libipt_RTPPROXY.c:44: error: (Each undeclared identifier is reported only once
iptables/extensions/libipt_RTPPROXY.c:44: error: for each function it appears in.)
iptables/extensions/libipt_RTPPROXY.c: At top level:
iptables/extensions/libipt_RTPPROXY.c:301: error: variable ‘rtpproxy’ has initializer but incomplete type
iptables/extensions/libipt_RTPPROXY.c:302: error: unknown field ‘version’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:302: error: ‘XTABLES_VERSION’ undeclared here (not in a function)
iptables/extensions/libipt_RTPPROXY.c:302: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:302: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:303: error: unknown field ‘name’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:303: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:303: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:304: error: unknown field ‘revision’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:304: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:304: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:305: error: unknown field ‘size’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:305: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:305: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:306: error: unknown field ‘userspacesize’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:306: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:306: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:307: error: unknown field ‘help’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:307: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:307: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:308: error: unknown field ‘init’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:308: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:308: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:309: error: unknown field ‘parse’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:309: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:309: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:310: error: unknown field ‘final_check’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:310: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:310: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:311: error: unknown field ‘print’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:311: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:311: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:312: error: unknown field ‘save’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:312: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:312: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c:313: error: unknown field ‘extra_opts’ specified in initializer
iptables/extensions/libipt_RTPPROXY.c:314: warning: excess elements in struct initializer
iptables/extensions/libipt_RTPPROXY.c:314: warning: (near initialization for ‘rtpproxy’)
iptables/extensions/libipt_RTPPROXY.c: In function ‘_init’:
iptables/extensions/libipt_RTPPROXY.c:317: warning: implicit declaration of function ‘xtables_register_target’
make: *** [iptables/extensions/libipt_RTPPROXY.o] Error 1

Which library/src am I missing ? What to do to get rid of this error ?
thnx