arnaldomf/dns

A Golang DNS implementation

dns

A Golang DNS implementation developed for learning purpose.

Building

The command below will build the program and create the executable file dns.

mkdir bin
go build -o bin/dns

Avaiable Commands

decode

The decode command prints the content of a dns message. The message may be provided from the stdin or from a file.

reading from a file

dns --path ./message

reading from stdin

cat ./message | dns --stdin

retrieving a dns message

There are many ways you can get a DNS message, but a quick way to do so is using dig and nc.

In a terminal, run the nc command:

nc -u -l -p 5553 > ./message

This will make nc to listen for a udp datagram on port 5553 and to write the datagram content to a file called message.

In another terminal, run the dig command:

dig +retry=0 -p 5553 @127.0.0.1 +noedns www.google.com

This instructs dig to send a DNS query to a server in localhost port 5553 (or nc command).