pub

internal/proxy/tcp.go

@@ -0,0 +1,59 @@
+package proxy
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"net"
+)
+
+// RunTCPProxy starts a basic TCP reverse proxy listening on the given port
+// and forwarding all traffic to the target backend.
+func RunTCPProxy(port int, targetBackend string) error {
+	addr := fmt.Sprintf(":%d", port)
+	listener, err := net.Listen("tcp", addr)
+	if err != nil {
+		return err
+	}
+	defer listener.Close()
+
+	log.Printf("Starting TCP proxy on %s, forwarding to %s\n", addr, targetBackend)
+
+	for {
+		clientConn, err := listener.Accept()
+		if err != nil {
+			log.Printf("TCP Accept error: %v", err)
+			continue
+		}
+
+		go handleTCPConnection(clientConn, targetBackend)
+	}
+}
+
+func handleTCPConnection(clientConn net.Conn, targetBackend string) {
+	defer clientConn.Close()
+
+	backendConn, err := net.Dial("tcp", targetBackend)
+	if err != nil {
+		log.Printf("TCP Dial error to %s: %v", targetBackend, err)
+		return
+	}
+	defer backendConn.Close()
+
+	errChan := make(chan error, 2)
+
+	// Copy data from client to backend
+	go func() {
+		_, err := io.Copy(backendConn, clientConn)
+		errChan <- err
+	}()
+
+	// Copy data from backend to client
+	go func() {
+		_, err := io.Copy(clientConn, backendConn)
+		errChan <- err
+	}()
+
+	// Wait for one of the streams to finish (either EOF or error)
+	<-errChan
+}