Compile grep/iptables under JNI

[nxia416]

Hey this is not really an issue because I can compile the app perfectly. I am trying to figure out how the grep and iptables are compiled. After I run "sudo ndk-build -B" I got an error:

arm-linux-androideabi-gcc: error: /libxt_AUDIT.c: No such file or directory
arm-linux-androideabi-gcc: fatal error: no input files
compilation terminated.
make: *** [obj/local/armeabi/objs/ext//libxt_AUDIT.o] Error 1

I am doing so because i need to install tcpdump to the app for a research project but I am not sure how. Any suggestions? I will really appreciate any help :)