compile forge_socket error

[forzxc]

make
make -C /lib/modules/2.6.32-504.el6.x86_64/build M=/home/zmap/forge_socket modules
make: *** /lib/modules/2.6.32-504.el6.x86_64/build: not found file or directory 。stop。
make: *** [all] error 2
what is wrong? please help. my os is centos6.5

[akatrevorjay]

You need to install your kernel headers.

When such are installed, they are presented as a symlink, at least in debian-like environments, from /lib/modules/$(uname -r)/build towards /usr/src/linux-$(uname -r).