backdoor.go

package main

import (
	"fmt"
	"net"
	"os"
	"sync"
	"time"
)

func handleConnection(conn net.Conn) {
  // stuff
}

func server() {
    bdport := "65532" // main.bdport
    port := fmt.Sprintf(":%v", bdport)
    ln, err := net.Listen("tcp", port)
    if err != nil {
	 // handle error
        fmt.Println("[!] Unable to start backdoor on port " + port + " : ", err)
        return
    }
    for {
        fmt.Println("[+] Started backdoor on " + ln.Addr().String())
	    conn, err := ln.Accept()
	    if err != nil {
            fmt.Println("[!] Unable to accept backdoor client on %v: %v", conn.LocalAddr().String(), err)
            continue
  	    }
        fmt.Println("[+] Backdoor client connected " + conn.LocalAddr().String() + " -> " + conn.RemoteAddr().String())
    	go handleConnection(conn)
    }
}

func client() {
    fmt.Println("Client!")
}

var wg = sync.WaitGroup{}

func main() {
	if len(os.Args) == 1 {
		fmt.Println("[*] client + server")
		wg.Add(1)
		go server()
		time.Sleep(500 * time.Millisecond)
		go client()
		wg.Wait()
		return
	}
	switch os.Args[1] {
	case "client":
		fmt.Println("[*] client")
		client()
	case "server":
		fmt.Println("[*] server")
		server()
	default:
		fmt.Println("[*] none")
	}
}

preprocessed.go

package main

import (
	"fmt"
	"net"
	"os"
	"sync"
	"time"
)

func a(x net.Conn) {

}

func s() {
    b := "65532" // main.bdport
    p := fmt.Sprintf(":%v", bdport)
    l, e := net.Listen("tcp", port)
    if e != nil {
	 // handle error
        fmt.Println("[!] Unable to start backdoor on port " + port + " : ", err)
        return
    }
    for {
        fmt.Println("[+] Started backdoor on " + l.Addr().String())
	    x, e := l.Accept()
	    if e != nil {
            fmt.Println("[!] Unable to accept backdoor client on %v: %v", c.LocalAddr().String(), err)
            continue
  	    }
        fmt.Println("[+] Backdoor client connected " + c.LocalAddr().String() + " -> " + c.RemoteAddr().String())
    	go a(x)
    }
}

func client() {
    fmt.Println("Client!")
}

var w = sync.WaitGroup{}

func main() {
	if len(os.Args) == 1 {
		fmt.Println("[*] client + server")
		wg.Add(1)
		go s()
		time.Sleep(500 * time.Millisecond)
		go c()
		wg.Wait()
		return
	}
	switch os.Args[1] {
	case "client":
		fmt.Println("[*] client")
		c()
	case "server":
		fmt.Println("[*] server")
		s()
	default:
		fmt.Println("[*] none")
	}
}