retryabledns

README

Retryable dns resolver

Based on miekg/dns and freely inspired by bogdanovich/dns_resolver.

Features

• Supports system default resolvers along with user supplied ones
• Retries dns requests in case of I/O/Time/Network failures
• Allows arbitrary query types
• Resolution with random resolvers

Using go get

$ go get github.com/projectdiscovery/retryabledns

After this command retryabledns library source will be in your $GOPATH

Example

Usage Example:

package main

import (
    "log"
    dns "github.com/projectdiscovery/retryabledns"
)

func main() {
    // it requires a list of resolvers
    resolvers := []string{"8.8.8.8", "8.8.4.4"}
    retries := 2
    hostname := "hackerone.com"
    dnsClient := dns.New(resolvers, retries)

    ips, err := dnsClient.Resolve(hostname)
    if err != nil {
        log.Fatal(err)
    }

    log.Println(ips)

    // Query Types: dns.TypeA, dns.TypeNS, dns.TypeCNAME, dns.TypeSOA, dns.TypePTR, dns.TypeMX
    // dns.TypeTXT, dns.TypeAAAA (from github.com/miekg/dns)
    dnsResponses, err := dnsClient.ResolveRaw(hostname, dns.TypeA)
    if err != nil {
        log.Fatal(err)
    }

    log.Println(dnsResponses)
}

Documentation

Index

• type Client
  • func New(baseResolvers []string, maxRetries int) *Client
  • func (c *Client) Do(msg *dns.Msg) (*dns.Msg, error)
  • func (c *Client) Query(host string, requestType uint16) (*DNSData, error)
  • func (c *Client) QueryMultiple(host string, requestTypes []uint16) (*DNSData, error)
  • func (c *Client) Resolve(host string) (*DNSData, error)
  • func (c *Client) ResolveWithSyscall(host string) (*DNSData, error)
• type DNSData
  • func (d *DNSData) JSON() (string, error)
  • func (d *DNSData) Marshal() ([]byte, error)
  • func (d *DNSData) ParseFromMsg(msg *dns.Msg) error
  • func (d *DNSData) Unmarshal(b []byte) error

Types

type Client

type Client struct {
	// contains filtered or unexported fields
}

Client is a DNS resolver client to resolve hostnames.

func New

func New(baseResolvers []string, maxRetries int) *Client

New creates a new dns client

func (*Client) Do

func (c *Client) Do(msg *dns.Msg) (*dns.Msg, error)

Do sends a provided dns request and return the raw native response

func (*Client) Query

func (c *Client) Query(host string, requestType uint16) (*DNSData, error)

Query sends a provided dns request and return enriched response

func (*Client) QueryMultiple

func (c *Client) QueryMultiple(host string, requestTypes []uint16) (*DNSData, error)

QueryMultiple sends a provided dns request and return the data

func (*Client) Resolve

func (c *Client) Resolve(host string) (*DNSData, error)

Resolve is the underlying resolve function that actually resolves a host and gets the ip records for that host.

func (*Client) ResolveWithSyscall

func (c *Client) ResolveWithSyscall(host string) (*DNSData, error)

ResolveWithSyscall attempts to resolve the host through system calls

type DNSData

type DNSData struct {
	Host       string   `json:"host,omitempty"`
	TTL        int      `json:"ttl,omitempty"`
	Resolver   []string `json:"resolver,omitempty"`
	A          []string `json:"a,omitempty"`
	AAAA       []string `json:"aaaa,omitempty"`
	CNAME      []string `json:"cname,omitempty"`
	MX         []string `json:"mx,omitempty"`
	PTR        []string `json:"ptr,omitempty"`
	SOA        []string `json:"soa,omitempty"`
	NS         []string `json:"ns,omitempty"`
	TXT        []string `json:"txt,omitempty"`
	Raw        string   `json:"raw,omitempty"`
	StatusCode string   `json:"status_code,omitempty"`
}

DNSData is the data for a DNS request response

func (*DNSData) JSON

func (d *DNSData) JSON() (string, error)

JSON returns the object as json string

func (*DNSData) Marshal

func (d *DNSData) Marshal() ([]byte, error)

Marshal encodes the dnsdata to a binary representation

func (*DNSData) ParseFromMsg

func (d *DNSData) ParseFromMsg(msg *dns.Msg) error

ParseFromMsg and enrich data

func (*DNSData) Unmarshal

func (d *DNSData) Unmarshal(b []byte) error

Unmarshal decodes the dnsdata from a binary representation