initial commit

connector/relay/connector.go

@@ -0,0 +1,127 @@
+package relay
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/go-gost/gost/v3/pkg/connector"
+	md "github.com/go-gost/gost/v3/pkg/metadata"
+	"github.com/go-gost/gost/v3/pkg/registry"
+	"github.com/go-gost/relay"
+	relay_util "github.com/go-gost/x/internal/util/relay"
+)
+
+func init() {
+	registry.ConnectorRegistry().Register("relay", NewConnector)
+}
+
+type relayConnector struct {
+	md      metadata
+	options connector.Options
+}
+
+func NewConnector(opts ...connector.Option) connector.Connector {
+	options := connector.Options{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	return &relayConnector{
+		options: options,
+	}
+}
+
+func (c *relayConnector) Init(md md.Metadata) (err error) {
+	return c.parseMetadata(md)
+}
+
+func (c *relayConnector) Connect(ctx context.Context, conn net.Conn, network, address string, opts ...connector.ConnectOption) (net.Conn, error) {
+	log := c.options.Logger.WithFields(map[string]any{
+		"remote":  conn.RemoteAddr().String(),
+		"local":   conn.LocalAddr().String(),
+		"network": network,
+		"address": address,
+	})
+	log.Infof("connect %s/%s", address, network)
+
+	if c.md.connectTimeout > 0 {
+		conn.SetDeadline(time.Now().Add(c.md.connectTimeout))
+		defer conn.SetDeadline(time.Time{})
+	}
+
+	req := relay.Request{
+		Version: relay.Version1,
+		Flags:   relay.CONNECT,
+	}
+	if network == "udp" || network == "udp4" || network == "udp6" {
+		req.Flags |= relay.FUDP
+
+		// UDP association
+		if address == "" {
+			baddr, err := c.bind(conn, relay.FUDP|relay.BIND, network, address)
+			if err != nil {
+				return nil, err
+			}
+			log.Debugf("associate on %s OK", baddr)
+
+			return relay_util.UDPTunClientConn(conn, nil), nil
+		}
+	}
+
+	if c.options.Auth != nil {
+		pwd, _ := c.options.Auth.Password()
+		req.Features = append(req.Features, &relay.UserAuthFeature{
+			Username: c.options.Auth.Username(),
+			Password: pwd,
+		})
+	}
+
+	if address != "" {
+		af := &relay.AddrFeature{}
+		if err := af.ParseFrom(address); err != nil {
+			return nil, err
+		}
+
+		// forward mode if port is 0.
+		if af.Port > 0 {
+			req.Features = append(req.Features, af)
+		}
+	}
+
+	if c.md.noDelay {
+		if _, err := req.WriteTo(conn); err != nil {
+			return nil, err
+		}
+	}
+
+	switch network {
+	case "tcp", "tcp4", "tcp6":
+		cc := &tcpConn{
+			Conn: conn,
+		}
+		if !c.md.noDelay {
+			if _, err := req.WriteTo(&cc.wbuf); err != nil {
+				return nil, err
+			}
+		}
+		conn = cc
+	case "udp", "udp4", "udp6":
+		cc := &udpConn{
+			Conn: conn,
+		}
+		if !c.md.noDelay {
+			if _, err := req.WriteTo(&cc.wbuf); err != nil {
+				return nil, err
+			}
+		}
+		conn = cc
+	default:
+		err := fmt.Errorf("network %s is unsupported", network)
+		log.Error(err)
+		return nil, err
+	}
+
+	return conn, nil
+}