TFTP Udp Hole Punching Helper Server

See this project for explanation.

Protocol

This server listens on the standard TFTP 69/udp port and waits for GET requests with filenames matching the regex v1_tftp_udp_\d+.

Details:

• v1 - protocol version
• _tftp_udp_ - literal string
• \d+ - local socket port number or 0

Request and response lengths are approximately equal in bytes, limiting the server’s usefulness in UDP amplification attacks.

Usage

It's recommended to run this daemon from systemd with limited priviliges using socket activation.

• install proper binary from build/*/tftpudpd into /usr/local/bin/tftpudpd
• copy tftpudpd.service and tftpudpd.socket from examples/systemd/ directory into /etc/systemd/system
• enable & start both tftpudpd.service and tftpudpd.socket with systemctl command