tunnelBackend/tunnelFrontend -> tcpTunnel (#170)

endpoints/tcpTunnel/backend.go

@@ -0,0 +1,120 @@
+package tcpTunnel
+
+import (
+	"github.com/openziti/sdk-golang/ziti"
+	"github.com/openziti/sdk-golang/ziti/config"
+	"github.com/openziti/sdk-golang/ziti/edge"
+	"github.com/openziti/transport/v2/tcp"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"net"
+	"time"
+)
+
+type BackendConfig struct {
+	IdentityPath    string
+	EndpointAddress string
+	ShrToken        string
+}
+
+type Backend struct {
+	cfg      *BackendConfig
+	listener edge.Listener
+}
+
+func NewBackend(cfg *BackendConfig) (*Backend, error) {
+	options := ziti.ListenOptions{
+		ConnectTimeout: 5 * time.Minute,
+		MaxConnections: 64,
+	}
+	zcfg, err := config.NewFromFile(cfg.IdentityPath)
+	if err != nil {
+		return nil, errors.Wrap(err, "error loading config")
+	}
+	listener, err := ziti.NewContextWithConfig(zcfg).ListenWithOptions(cfg.ShrToken, &options)
+	if err != nil {
+		return nil, errors.Wrap(err, "error listening")
+	}
+	b := &Backend{
+		cfg:      cfg,
+		listener: listener,
+	}
+	return b, nil
+}
+
+func (b *Backend) Run() error {
+	logrus.Info("started")
+	defer logrus.Info("exited")
+
+	for {
+		if conn, err := b.listener.Accept(); err == nil {
+			go b.handle(conn)
+		} else {
+			return err
+		}
+	}
+}
+
+func (b *Backend) handle(conn net.Conn) {
+	logrus.Infof("handling '%v'", conn.RemoteAddr())
+	rConn, err := tcp.Dial(b.cfg.EndpointAddress, "tcp", 30*time.Second)
+	if err != nil {
+		logrus.Errorf("error dialing '%v': %v", b.cfg.EndpointAddress, err)
+		_ = conn.Close()
+		return
+	}
+	go b.rxer(conn, rConn)
+	go b.txer(conn, rConn)
+}
+
+func (b *Backend) rxer(conn, rConn net.Conn) {
+	logrus.Infof("started '%v' <=> '%v'", conn.RemoteAddr(), rConn.RemoteAddr())
+	defer logrus.Warnf("exited '%v' <=> '%v'", conn.RemoteAddr(), rConn.RemoteAddr())
+
+	buf := make([]byte, 10240)
+	for {
+		if rxsz, err := conn.Read(buf); err == nil {
+			if txsz, err := rConn.Write(buf[:rxsz]); err == nil {
+				if txsz != rxsz {
+					logrus.Errorf("short write '%v' (%d != %d)", rConn.RemoteAddr(), txsz, rxsz)
+				}
+			} else {
+				logrus.Errorf("error writing '%v': %v", rConn.RemoteAddr(), err)
+				_ = rConn.Close()
+				_ = conn.Close()
+				return
+			}
+		} else {
+			logrus.Errorf("read error '%v': %v", rConn.RemoteAddr(), err)
+			_ = rConn.Close()
+			_ = conn.Close()
+			return
+		}
+	}
+}
+
+func (b *Backend) txer(conn, rConn net.Conn) {
+	logrus.Infof("started '%v' <=> '%v'", conn.RemoteAddr(), rConn.RemoteAddr())
+	defer logrus.Warnf("exited '%v' <=> '%v'", conn.RemoteAddr(), rConn.RemoteAddr())
+
+	buf := make([]byte, 10240)
+	for {
+		if rxsz, err := rConn.Read(buf); err == nil {
+			if txsz, err := conn.Write(buf[:rxsz]); err == nil {
+				if txsz != rxsz {
+					logrus.Errorf("short write '%v' (%d != %d)", conn.RemoteAddr(), txsz, rxsz)
+				}
+			} else {
+				logrus.Errorf("error writing '%v': %v", conn.RemoteAddr(), err)
+				_ = rConn.Close()
+				_ = conn.Close()
+				return
+			}
+		} else {
+			logrus.Errorf("read error '%v': %v", conn.RemoteAddr(), err)
+			_ = rConn.Close()
+			_ = conn.Close()
+			return
+		}
+	}
+}