add tunnel feature for relay

connector/relay/metadata.go

@@ -5,21 +5,33 @@ import (
 
 	mdata "github.com/go-gost/core/metadata"
 	mdutil "github.com/go-gost/core/metadata/util"
+	"github.com/go-gost/relay"
+	"github.com/google/uuid"
 )
 
 type metadata struct {
 	connectTimeout time.Duration
 	noDelay        bool
+	tunnelID       relay.TunnelID
 }
 
 func (c *relayConnector) parseMetadata(md mdata.Metadata) (err error) {
 	const (
 		connectTimeout = "connectTimeout"
 		noDelay        = "nodelay"
+		tunnelID       = "tunnelID"
 	)
 
 	c.md.connectTimeout = mdutil.GetDuration(md, connectTimeout)
 	c.md.noDelay = mdutil.GetBool(md, noDelay)
 
+	if s := mdutil.GetString(md, tunnelID); s != "" {
+		uuid, err := uuid.Parse(s)
+		if err != nil {
+			return err
+		}
+		copy(c.md.tunnelID[:], uuid[:])
+	}
+
 	return
 }