// ucspi/cmd/proxy -- UCSPI TCP proxy
// Copyright (C) 2021-2024 Sergey Matveev <stargrave@stargrave.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 3 of the License.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package main

import (
	"flag"
	"fmt"
	"io"
	"log"
	"os"
)

func main() {
	flag.Usage = func() {
		fmt.Fprintln(os.Stderr, "Usage: UCSPIserver [address] UCSPIclient [address] ucspi-proxy")
	}
	flag.Parse()
	log.SetFlags(log.Lshortfile)

	r := os.NewFile(6, "R")
	if r == nil {
		log.Fatalln("no 6 file descriptor")
	}
	w := os.NewFile(7, "W")
	if w == nil {
		log.Fatalln("no 7 file descriptor")
	}
	worker := make(chan struct{})
	var err error
	go func() {
		_, err = io.Copy(w, os.Stdin)
		w.Close()
		close(worker)
	}()
	go func() {
		io.Copy(os.Stdout, r)
	}()
	<-worker
	if err != nil {
		log.Fatalln(err)
	}
}