mpac is a tool for creating Ethernet-TCP/IP packets with payload. Packets are built with plaintext configuration files representing each layer (ethernet, ip, tcp, payload).
You can download it from the following link: https://packetstormsecurity.com/files/download/11124/Mpac101_tar.gz
Source: https://packetstormsecurity.com/files/11124/Mpac101_tar.gz.html