diff --git a/openflow/utils.go b/openflow/utils.go
new file mode 100644
index 0000000..160b2ab
--- /dev/null
+++ b/openflow/utils.go
@@ -0,0 +1,40 @@
+/*
+   Copyright 2017 the original author or authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package openflow
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+)
+
+var mu sync.Mutex
+var xid uint32 = 1
+
+func GetXid() uint32 {
+	mu.Lock()
+	defer mu.Unlock()
+	xid++
+	return xid
+}
+func PadString(value string, padSize int) string {
+	size := len(value)
+	nullsNeeded := padSize - size
+	null := fmt.Sprintf("%c", '\000')
+	padded := strings.Repeat(null, nullsNeeded)
+	return fmt.Sprintf("%s%s", value, padded)
+}