add binder for connector

pkg/chain/route.go

@@ -3,7 +3,10 @@ package chain
 import (
 	"context"
 	"errors"
+	"fmt"
 	"net"
+
+	"github.com/go-gost/gost/pkg/connector"
 )
 
 var (
@@ -93,6 +96,41 @@ func (r *Route) dialDirect(ctx context.Context, network, address string) (net.Co
 	return d.DialContext(ctx, network, address)
 }
 
+func (r *Route) Bind(ctx context.Context, network, address string) (connector.Accepter, error) {
+	if r.IsEmpty() {
+		return r.bindLocal(ctx, network, address)
+	}
+
+	conn, err := r.Connect(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	accepter, err := r.Last().transport.Bind(ctx, conn, network, address)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	return accepter, nil
+}
+
+func (r *Route) bindLocal(ctx context.Context, network, address string) (connector.Accepter, error) {
+	switch network {
+	case "tcp", "tcp4", "tcp6":
+		addr, err := net.ResolveTCPAddr(network, address)
+		if err != nil {
+			return nil, err
+		}
+		return net.ListenTCP(network, addr)
+	case "udp", "udp4", "udp6":
+		return nil, nil
+	default:
+		err := fmt.Errorf("network %s unsupported", network)
+		return nil, err
+	}
+}
+
 func (r *Route) IsEmpty() bool {
 	return r == nil || len(r.nodes) == 0
 }

pkg/chain/router.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net"
 
+	"github.com/go-gost/gost/pkg/connector"
 	"github.com/go-gost/gost/pkg/logger"
 )
 
@@ -59,6 +60,35 @@ func (r *Router) Dial(ctx context.Context, network, address string) (conn net.Co
 	return
 }
 
+func (r *Router) Bind(ctx context.Context, network, address string) (accepter connector.Accepter, err error) {
+	count := r.retries + 1
+	if count <= 0 {
+		count = 1
+	}
+	r.logger.Debugf("bind: %s/%s", address, network)
+
+	for i := 0; i < count; i++ {
+		route := r.chain.GetRouteFor(network, address)
+
+		if r.logger.IsLevelEnabled(logger.DebugLevel) {
+			buf := bytes.Buffer{}
+			for _, node := range route.Path() {
+				fmt.Fprintf(&buf, "%s@%s > ", node.Name(), node.Addr())
+			}
+			fmt.Fprintf(&buf, "%s", address)
+			r.logger.Debugf("route(retry=%d): %s", i, buf.String())
+		}
+
+		accepter, err = route.Bind(ctx, network, address)
+		if err == nil {
+			break
+		}
+		r.logger.Errorf("route(retry=%d): %s", i, err)
+	}
+
+	return
+}
+
 func (r *Router) Connect(ctx context.Context) (conn net.Conn, err error) {
 	count := r.retries + 1
 	if count <= 0 {

pkg/chain/transport.go

@@ -62,6 +62,13 @@ func (tr *Transport) Connect(ctx context.Context, conn net.Conn, network, addres
 	return tr.connector.Connect(ctx, conn, network, address)
 }
 
+func (tr *Transport) Bind(ctx context.Context, conn net.Conn, network, address string) (connector.Accepter, error) {
+	if binder, ok := tr.connector.(connector.Binder); ok {
+		return binder.Bind(ctx, conn, network, address, connector.MuxBindOption(true))
+	}
+	return nil, connector.ErrBindUnsupported
+}
+
 func (tr *Transport) IsMultiplex() bool {
 	if mux, ok := tr.dialer.(dialer.Multiplexer); ok {
 		return mux.IsMultiplex()