package main

import (
	"fmt"
	"net"
	"log"
	"sync"
	"syscall"
	"flag"
)

type Options struct {
	ConfigPath string
	Jail bool
}

func ParseOptions() Options {
	var opts Options

	flag.StringVar(&opts.ConfigPath, "config", "dentata.json", "config.json to load")
	flag.BoolVar(&opts.Jail, "jail", false, "drop to low priv jail")

	flag.Parse()

	return opts
}


func handleConnection(conn net.Conn) {
	defer conn.Close()
	addr := conn.RemoteAddr()
	fmt.Println("Connect from", addr.Network(), addr.String())

	// send explosion notice to dentata
	report, err := net.Dial("tcp","127.0.0.1:9001")
	if err != nil { panic(err) }
	defer report.Close()

	report.Write([]byte(addr.String()))
}


func listener(addr string) {
	server, err := net.Listen("tcp", addr)

	if err != nil { panic(err) }

	for {
		conn, err := server.Accept()

		if err != nil {	
			log.Println("ACCEPT ERROR", err)
		} else {
			go handleConnection(conn)
		}
	}
}

func ChrootJailLOL() {
	err := syscall.Chdir("tmp")
	if err != nil { panic(err) }

	err = syscall.Chroot(".")
	if err != nil { panic(err) }

	err = syscall.Setuid(1000)
	if err != nil { panic(err) }

	syscall.Setgid(1000)
	if err != nil { panic(err) }
}

func main() {
	opts := ParseOptions()

	var wg sync.WaitGroup

	for i := 0; i < 10; i++ {
		wg.Go(func () {
			listener(fmt.Sprintf("0.0.0.0:%d", 8000 + i))
		})
	}

	if opts.Jail {
		ChrootJailLOL()
	}

	wg.Wait()
}