dip/functions.go

package main

import (
	"flag"
	"fmt"
	"net"
	"net/http"
	"os"
	"strings"
  "log"

	"github.com/labstack/echo/v4"
	"github.com/likexian/whois-go"
	whoisparser "github.com/likexian/whois-parser-go"
)

// GetIPInfo returns IP address informations
func GetIPInfo(c echo.Context) (ip IP, err error) {
	if c.QueryParam("ip") != "" {
		ip.IP = c.QueryParam("ip")
	} else {
		ip.IP = c.RealIP()
	}

	err = ip.CheckIPAddress()
	if err != nil {
	  log.Println(fmt.Sprintf("Error checking IP address %s",ip.IP))
	}

	err = ip.GetHostname()
	if err != nil {
	  log.Println(fmt.Sprintf("Error checking revers DNS for IP address %s",ip.IP))
	}

	return
}

// Dip return webpage
func Dip(c echo.Context) (err error) {
	var ip IP

	ip, err = GetIPInfo(c)
  fmt.Println(err)
	if err != nil {
		return c.Render(http.StatusInternalServerError, "error.html", nil)
	}

	if strings.Contains(c.Request().Header.Get(echo.HeaderAccept), echo.MIMETextHTML) {
		return c.Render(http.StatusOK, "index.html", ip)
	} else {
		return c.JSON(http.StatusOK, ip)
	}
}

// Static returns static files
func Static(c echo.Context) (err error) {
	//static := c.Param("static")
	return c.Render(http.StatusOK, "static/js/uikit-icons.js", "")
}

// CheckIPAddress check if ip is an IP address, return err if there's an error
func (ip *IP) CheckIPAddress() (err error) {
	addr := net.ParseIP(ip.IP)
	if addr == nil {
		return fmt.Errorf("Supplied string isn't an IP address")
	}
	return
}

// GetHostname assign ip.Hostname value
func (ip *IP) GetHostname() (err error) {
	revip, err := net.LookupAddr(ip.IP)
	if err != nil {
		return fmt.Errorf(fmt.Sprintf("Supplied address %s doesn't have a valid reverse DNS entry", ip.IP))
	}
	ip.Hostname = revip[0]
	return
}

// GetWhois not implemented yet
func (ip *IP) GetWhois() (err error) {
	resultraw, err := whois.Whois("example.com")
	//resultraw, err := whois.Whois(ip.IP)
	fmt.Println(resultraw)
	result, err := whoisparser.Parse(resultraw)
	if err != nil {
		return
	}
	fmt.Println(result)
	return
}

// Usage displays possible arguments
func Usage() {
	flag.PrintDefaults()
	os.Exit(1)
}

// IP defines dip main struct
type IP struct {
	IP       string `json:"ip"`
	Hostname string `json:"hostname"`
}