Simple FI-domain availability checking

main.go

@@ -0,0 +1,183 @@
+package main
+
+import (
+	"database/sql"
+	"encoding/json"
+	"encoding/xml"
+	"fmt"
+	"html/template"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"io"
+	"strings"
+	"bytes"
+	"errors"
+	_ "modernc.org/sqlite"
+)
+
+type Config struct {
+	Port uint
+	SiteName string
+}
+
+type page struct {
+	Title string
+}
+
+type xmlDomain struct {
+	authority string
+	registryType string
+	entityClass string
+	entityName string
+}
+
+var C = Config{}
+var db *sql.DB
+
+func main() {	
+	var err error
+
+	domain := "snuff.fi"
+	av, err := checkDomainAvailability(domain)
+	if err != nil {
+		log.Fatal(err)
+		return
+	}
+	fmt.Printf("Domain '%s' available: %t\n", domain, av)
+	return
+	
+	// Load config
+	fmt.Println("Loading config.json")
+	cfgfile, err := os.Open("config.json")
+	if err != nil {
+		log.Fatal("Error reading config.json!")
+		return
+	}
+	defer cfgfile.Close()
+	
+	decoder := json.NewDecoder(cfgfile)
+	//Config := Config{}
+	err = decoder.Decode(&C)
+	if err != nil {
+		log.Fatal("Can't decode config.json!")
+		return
+	}
+
+
+
+	
+	db, err = sql.Open("sqlite", "database.db")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf("Starting listener on :%v", C.Port)
+	http.Handle("/static/", http.FileServer(http.Dir("./")))
+	http.HandleFunc("/", httpRootHandler)
+	err = http.ListenAndServe(fmt.Sprintf(":%v", C.Port), nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	db.Close()
+}
+
+func httpRootHandler(w http.ResponseWriter, r *http.Request) {
+	t, _ := template.ParseFiles("index.html")
+	// var err := do_get_stuff()
+	// if err != nil {
+	// 	log.Fatal(err)
+	// 	http.Error(w, http.StatusText(500), 500)
+	// 	return
+	// }
+
+	
+	
+	var p page
+	p.Title = C.SiteName;
+	t.Execute(w, p)
+}
+
+func checkDomainAvailability(domain string) (bool, error) {
+	dasHost := "das.domain.fi";
+	dasPort := 715
+	dasAddr := fmt.Sprintf("%s:%d", dasHost, dasPort)
+	request := fmt.Sprintf(`<?xml version="1.0" encoding="UTF-8"?>
+<iris1:request xmlns:iris1="urn:ietf:params:xml:ns:iris1">
+<iris1:searchSet>
+<iris1:lookupEntity registryType="dchk1" entityClass="domain-name" entityName="%s"/>
+</iris1:searchSet>
+</iris1:request>`, domain)
+	
+	conn, err := net.Dial("udp", dasAddr)
+	if err != nil {
+		log.Fatal(err)
+		return false, err
+	}
+	defer conn.Close()
+
+	fmt.Fprintf(conn, request)
+	response := make([]byte, 1024)
+	_, err = conn.Read(response)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	response = bytes.Trim(response, "\x00")
+
+	// Response can be:
+	// - active: already in use
+	// - available: go ahead and grab it while you can
+	// - invalid: malformed request: maybe check domain has .fi in the end
+	isAvailable, err := xmlCheckTag(string(response), "available")
+	if err != nil {
+		log.Fatal(err)
+		return false, err
+	} else if isAvailable {
+		// Domain is available
+		return true, nil
+	}
+	
+	isActive, err := xmlCheckTag(string(response), "active")
+	if err != nil {
+		log.Fatal(err)
+		return false, err
+	} else if isActive {
+		// Domain is already registered taken
+		return false, nil
+	}
+	
+	isInvalid, err := xmlCheckTag(string(response), "invalid")
+	if err != nil {
+		log.Fatal(err)
+		return false, err
+	} else if isInvalid {
+		// We got bonked for our request
+		return false, errors.New("Request or domain invalid")
+	}
+
+	// Execution should not lead here but hey might as well error it out
+	return false, errors.New("Error: Status field not found")
+}
+
+func xmlCheckTag(src, tag string) (bool, error) {
+	// Thanks icza for your stackoverflow
+	// https://stackoverflow.com/a/51649834
+	decoder := xml.NewDecoder(strings.NewReader(src))
+	for {
+		t, err := decoder.Token()
+		if err != nil {
+			if err == io.EOF {
+				return false, nil
+			}
+			return false, err
+		}
+		if se, ok := t.(xml.StartElement); ok {
+			if se.Name.Local == tag {
+				return true, nil
+			}
+		}
+	}
+}