#17 add command implementation

cmd/tcpproxy/main.go

@@ -1,5 +1,52 @@
 package main
 
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+
+	"waffle/internal/proxy"
+)
+
 func main() {
+	ctx := context.Background()
+
+	go func() {
+		if err := tcpDummy(); err != nil {
+			log.Panicf("dummy: %s", err.Error())
+		}
+	}()
+
+	sender := proxy.NewTCPSender("127.0.0.1:8083", "127.0.0.1:8081")
+	receiver := proxy.NewTCPReceiver("127.0.0.1:8080", sender)
+
+	if err := sender.Start(ctx); err != nil {
+		log.Panicf("start sender: %s", err.Error())
+	}
+
+	if err := receiver.Run(); err != nil {
+		log.Panicf("run receiver: %s", err.Error())
+	}
+}
+
+func tcpDummy() error {
+	addr, err := net.ResolveTCPAddr("tcp", ":8081")
+	if err != nil {
+		return fmt.Errorf("resolve tcp addr: %w", err)
+	}
+
+	listener, err := net.ListenTCP("tcp", addr)
+	if err != nil {
+		return fmt.Errorf("listen tcp: %w", err)
+	}
+
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			return fmt.Errorf("liistener accept: %w", err)
+		}
 
+		log.Println(conn)
+	}
 }

internal/proxy/tcp.go

@@ -18,9 +18,10 @@ type TCPReceiver struct {
 	sender    Sender // sender is a sender where tcp bytes are supposed to be redirected
 }
 
-func NewTCPReceiver(localAddr string) *TCPReceiver {
+func NewTCPReceiver(localAddr string, sender Sender) *TCPReceiver {
 	return &TCPReceiver{
 		localAddr: localAddr,
+		sender:    sender,
 	}
 }
 
@@ -106,9 +107,10 @@ func (s *TCPSender) Accept(rw io.ReadWriter) error {
 // startRemoteSender is used to start process of sending incoming bytes to the host.
 // It should be called in another go routine in order to not block the main routine.
 func (s *TCPSender) startRemoteSender(ctx context.Context, listenAddr, remoteAddr *net.TCPAddr) {
-	conn, err := net.DialTCP("tcp", listenAddr, remoteAddr)
+	conn, err := net.DialTCP("tcp", remoteAddr, listenAddr)
 	if err != nil {
 		fmt.Printf("error dialing remote host: %s", err.Error())
+		return
 	}
 
 	defer func() {