refactor: seperate application into seperate files and add killForwarding

forwarder.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"io"
+	"log"
+	"net"
+
+	"golang.org/x/crypto/ssh"
+)
+
+type PortFowarder struct {
+	sshCon     *ssh.Client
+	localPort  string
+	remotePort string
+	remoteHost string
+}
+
+func NewPortForwarder(sshCon *ssh.Client, localPort, remotePort, remoteHost string) *PortFowarder {
+	return &PortFowarder{
+		sshCon:     sshCon,
+		localPort:  localPort,
+		remotePort: remotePort,
+		remoteHost: remoteHost,
+	}
+}
+
+func (pw *PortFowarder) forward() error {
+	listener, err := net.Listen("tcp", "127.0.0.1:"+pw.localPort)
+	if err != nil {
+		log.Printf("Fehler beim Öffnen des lokalen Ports %s: %v", pw.localPort, err)
+		return err
+	}
+	defer listener.Close()
+
+	for {
+		localConn, err := listener.Accept()
+		if err != nil {
+			log.Printf("Fehler beim Akzeptieren der Verbindung: %v", err)
+			continue
+		}
+
+		remoteConn, err := pw.sshCon.Dial("tcp", pw.remoteHost+":"+pw.remotePort)
+		if err != nil {
+			log.Printf("Fehler beim Verbinden zum Remote-Host %s:%s: %v", pw.remoteHost, pw.remotePort, err)
+			localConn.Close()
+			continue
+		}
+
+		go pw.copyConn(localConn, remoteConn)
+		go pw.copyConn(remoteConn, localConn)
+	}
+}
+
+func (pw *PortFowarder) copyConn(dst, src net.Conn) {
+	defer dst.Close()
+	defer src.Close()
+	io.Copy(dst, src)
+}