Cerb - system firewall mechanism.
It's a kernel module, which is a complete security solution for FreeBSD.
- Fine graind supervision of selected system calls and their arguments.
- Possibility of system call arguments and return value change
- Nearly arbitratry process properties' modification
- Free runtime sysctl modification
- Precise and configurable logging
- Intuitive, flexible and powerful rule description language
For more information see Cerb Documentation: