Added TCP proxy to proxy to different site

blackhatgo/chapter2/TcpProxy.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"io"
+	"log"
+	"net"
+)
+
+func handle(conn net.Conn) {
+	destConn, err := net.Dial("tcp", "scanme.nmap.org:80")
+	if err != nil {
+		log.Fatalln("Unable to connect to scan me ", err)
+	}
+	go func() {
+		_, err = io.Copy(destConn, conn)
+		if err != nil {
+			log.Fatalln("Unable to copy to dest writer ", err)
+		}
+	}()
+
+	_, err = io.Copy(conn, destConn)
+	if err != nil {
+		log.Fatalln("unable to copy response to source writer ", err)
+	}
+}
+
+func main() {
+	listener, err := net.Listen("tcp", ":9091")
+	if err != nil {
+		log.Fatalln("Unable to listen ", err)
+	}
+	for {
+		conn, err2 := listener.Accept()
+		if err2 != nil {
+			log.Fatalln("Unable to accept ", err2)
+		}
+		go handle(conn)
+	}
+}