From cb8f1f178ad92898a77a293d368d65849d206497 Mon Sep 17 00:00:00 2001
From: jbergner <jbergner@send.nrw>
Date: Fri, 17 Jan 2025 21:58:08 +0100
Subject: [PATCH] =?UTF-8?q?Weitere=20Tests=20f=C3=BCr=20IPv6?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 main.go | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/main.go b/main.go
index 7a38249..9db9850 100644
--- a/main.go
+++ b/main.go
@@ -17,6 +17,12 @@ import (
 	"github.com/miekg/dns"
 )
 
+/*
+
+DNS-Status-Code übersicht: https://pkg.go.dev/github.com/miekg/dns@v1.1.62#TypeSOA
+
+*/
+
 type DB map[string]dns_entry
 
 var D map[string]dns_entry
@@ -213,6 +219,57 @@ func handlerIP(w http.ResponseWriter, r *http.Request) {
 	w.Write([]byte(remoteIP))
 }
 
+func handlerIPv6Pro(w http.ResponseWriter, r *http.Request) {
+	// Funktion zum Extrahieren der IP-Adresse
+	getIP := func(r *http.Request) string {
+		// Prüfen, ob X-Forwarded-For vorhanden ist (für Proxys)
+		xff := r.Header.Get("X-Forwarded-For")
+		if xff != "" {
+			// X-Forwarded-For kann mehrere IPs enthalten (Client, Proxy, etc.)
+			ips := strings.Split(xff, ",")
+			return strings.TrimSpace(ips[0])
+		}
+
+		// Prüfen, ob X-Real-IP vorhanden ist (eine alternative Proxy-Header-Option)
+		xRealIP := r.Header.Get("X-Real-IP")
+		if xRealIP != "" {
+			return xRealIP
+		}
+
+		// Fallback: RemoteAddr verwenden
+		host, _, err := net.SplitHostPort(r.RemoteAddr)
+		if err != nil {
+			return r.RemoteAddr // Falls SplitHostPort fehlschlägt, gib die Raw-Adresse zurück
+		}
+		return host
+	}
+
+	// Die IP-Adresse des Clients auslesen
+	clientIP := getIP(r)
+
+	// Prüfen, ob IPv4 oder IPv6
+	parsedIP := net.ParseIP(clientIP)
+	if parsedIP == nil {
+		http.Error(w, "Ungültige IP-Adresse", http.StatusInternalServerError)
+		return
+	}
+
+	// Ausgabe der Adresse
+	if parsedIP.To4() != nil {
+		fmt.Fprintf(w, "Client IPv4-Adresse: %s\n", clientIP)
+	} else {
+		fmt.Fprintf(w, "Client IPv6-Adresse: %s\n", clientIP)
+	}
+
+	// Optionale Ausgabe aller Header (Debugging)
+	fmt.Fprintln(w, "\nAlle HTTP-Header:")
+	for name, values := range r.Header {
+		for _, value := range values {
+			fmt.Fprintf(w, "%s: %s\n", name, value)
+		}
+	}
+}
+
 func handleDNSRequest(w dns.ResponseWriter, r *dns.Msg) {
 	// Bereite die Antwort vor
 	msg := new(dns.Msg)
@@ -415,6 +472,7 @@ func main() {
 
 	http.HandleFunc("/", handler)
 	http.HandleFunc("/ip", handlerIP)
+	http.HandleFunc("/ipv6", handlerIPv6Pro)
 
 	/* DNS-PART */