Add a new protocol

Co-authored-by: Gérald Croës <gerald@containo.us>

tcp/switcher.go

@@ -0,0 +1,28 @@
+package tcp
+
+import (
+	"net"
+
+	"github.com/containous/traefik/safe"
+)
+
+// HandlerSwitcher is a TCP handler switcher
+type HandlerSwitcher struct {
+	router safe.Safe
+}
+
+// ServeTCP forwards the TCP connection to the current active handler
+func (s *HandlerSwitcher) ServeTCP(conn net.Conn) {
+	handler := s.router.Get()
+	h, ok := handler.(Handler)
+	if ok {
+		h.ServeTCP(conn)
+	} else {
+		conn.Close()
+	}
+}
+
+// Switch sets the new TCP handler to use for new connections
+func (s *HandlerSwitcher) Switch(handler Handler) {
+	s.router.Set(handler)
+}