Initial import

cmd/protodial/main.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"os"
+	"strings"
+	"sync"
+
+	"git.maze.io/go/dpi/protocol"
+)
+
+func main() {
+	acceptFlag := flag.String("accept", "", "comma separated list of accepted protocols")
+	flag.Parse()
+
+	if flag.NArg() != 2 {
+		fmt.Fprintf(os.Stderr, "Usage: %s <host> <port>\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	accept := make(map[string]bool)
+	acceptFlags := strings.Split(*acceptFlag, ",")
+	if len(acceptFlags) == 0 {
+		fmt.Fprintln(os.Stderr, "No -accept was provided, refusing all protocols!")
+	} else {
+		for _, proto := range acceptFlags {
+			accept[proto] = true
+		}
+	}
+
+	c, err := net.Dial("tcp", net.JoinHostPort(flag.Arg(0), flag.Arg(1)))
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	c = protocol.Limit(c, func(dir protocol.Direction, p *protocol.Protocol) error {
+		if p == nil {
+			return errors.New("No protocol detected")
+		}
+		if !accept[p.Name] {
+			return fmt.Errorf("Protocol %s is not accepted", p.Name)
+		}
+		fmt.Fprintf(os.Stderr, "Accepting protocol %s version %s initiated by %s\n",
+			p.Name, p.Version, dir)
+		return nil
+	})
+	defer c.Close()
+
+	var wait sync.WaitGroup
+	wait.Go(func() { multiplex(c, os.Stdin) })
+	wait.Go(func() { multiplex(os.Stdout, c) })
+	wait.Wait()
+}
+
+func multiplex(w io.Writer, r io.Reader) {
+	if _, err := io.Copy(w, r); err != nil && !errors.Is(err, io.EOF) {
+		log.Fatalln("Copy terminated:", err)
+	}
+}