nslookup-go

This library let you do nslookup by UDP connection. You can choose the server, what you want to use or use default 8.8.8.8 server.

Supported query types

TypeA = 1 //IPv4
TypeNS = 2
TypeCNAME = 5
TypePTR = 12
TypeMX = 15
TypeTXT = 16
TyepAAAA= 28 //IPv6

Example usage

package main

import (
	"fmt"
	"log"

	"github.com/P1tirim/nslookup-go"
)

func main(){
    // Accept domain as first parametr and ip of DNS server as second.
    // You can not passing DNS server, then will be use standart 8.8.8.8 server
    // Return []net.IP
    ips, err := nslookup.LookupIP("google.com", "")
	if err != nil {
		log.Fatal(err)
	}

	for _, ip := range ips {
		fmt.Println("IP: " + ip.String())
	}
}

Another expamples you can find in the folder "examples"

Advanced usage

If you want to get answer from DNS server by DNS protocol message, then this exapmle for you

package main

import (
	"fmt"
	"log"

	"github.com/P1tirim/nslookup-go"
)

func main(){
    query := nslookup.NewQueryDNS("google.com", nslookup.TypeA)

    // This function return nslookup.Response
	resp, err := query.Lookup("8.8.8.8:53")
	if err != nil {
		log.Fatal(err)
	}

    // You need to assert every answer to struct
	for _, answer := range resp.Answers {
		if answer.Type == nslookup.TypeA {
			fmt.Println("IPv4: " + answer.Data.(nslookup.AnswerTypeString).Data)
		}
	}
}

The struct, what returns DNS server

type Response struct {
	TransactionID     uint16
	Flags             uint16
	QuestionsCount    uint16
	AnswersCount      uint16
	AuthorityCounts   uint16
	AdditionalCounts  uint16
	Queries           []Query
	Answers           []Answer
	AuthorityRecords  []Answer
	AdditionalRecords []Answer
}