humandns53

humandns53

A reference implementation of humandns dns server: the dns server part of humandns

Run

$ go run . &
Listening at:  :1053

$ dig ack-ack-ack-low.ip4  @localhost -p 1053

; <<>> DiG 9.16.31-RH <<>> ack-ack-ack-low.ip4 @localhost -p 1053
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 23558
;; flags: qr; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;ack-ack-ack-low.ip4.		IN	A

;; ANSWER SECTION:
ack-ack-ack-low.ip4.	31337	IN	A	127.0.0.1

;; Query time: 0 msec
;; SERVER: ::1#1053(::1)
;; WHEN: Sun Feb 12 00:03:47 AEST 2023
;; MSG SIZE  rcvd: 72

Concepts

• Go structs and methods (Structs Instead of Classes - OOP in Go)
• Goroutines (Rob Pike - 'Concurrency Is Not Parallelism')
• Go slices (Go's dynamic lists)
• Efficiently writing to and reading from structs using binary.Read() and binary.Write() respectively
• DNS protocol (RFC 1035: Domain Names - Implementation and Specification)

TODO

• Add support for IPv6 records

Links

• RFC 1035: Domain Names - Implementation and Specification
• DNS Query Message Format
• Wireshark
• Structs Instead of Classes - OOP in Go
• Rob Pike - 'Concurrency Is Not Parallelism'