gotftpd

Go TFTP server

TFTP Background

This is a very simple implementation of a TFTP server. TFTP is a very simple protocol to transfer files. It is from this that the name comes, Trivial File Transfer Protocol or TFTP.

TFTP is defined in RFC 1350

Usage

  -addr string
    	Address to listen (default "0.0.0.0:69")
  -path string
    	Local file path (default ".")

-addr is the address/port that the system will listen on, 0.0.0.0 means the system will listen to any incoming connections.

-path is the directory where the files that need to be served are currently stored.

Example

We want to serve a firmware image for a router to update from. The file is called newfirmware.bin and we are storing it in our firmware folder. Our computer and user has the permissions to run on privileged ports (<1024).

Change directory to where the file is stored.

cd firmware

List the files to make sure the file is stored.

ls -l

total 1640
-rw-r--r-- 1 peterp peterp 1678336 Sep 26 09:38 newfirmware.bin

Start running the gotftpd server.

gotfptd

A client (router) connects and downloads the file.

1678336 bytes sent

When a client downloads the file we can that the transfer happened.

Common messages

You may see messages like.

read udp [::]:47539: i/o timeout
read udp [::]:32901: i/o timeout

This is common and is just the connection from a previous active session closing.