1 files changed, 37 insertions, 0 deletions
diff --git a/plugin/rewrite/wire.go b/plugin/rewrite/wire.go
new file mode 100644
index 000000000..116b7dcc1
--- /dev/null
+++ b/plugin/rewrite/wire.go
@@ -0,0 +1,37 @@
+package rewrite
+
+import (
+	"encoding/binary"
+	"fmt"
+	"net"
+	"strconv"
+)
+
+// ipToWire writes IP address to wire/binary format, 4 or 16 bytes depends on IPV4 or IPV6.
+func ipToWire(family int, ipAddr string) ([]byte, error) {
+
+	switch family {
+	case 1:
+		return net.ParseIP(ipAddr).To4(), nil
+	case 2:
+		return net.ParseIP(ipAddr).To16(), nil
+	}
+	return nil, fmt.Errorf("invalid IP address family (i.e. version) %d", family)
+}
+
+// uint16ToWire writes unit16 to wire/binary format
+func uint16ToWire(data uint16) []byte {
+	buf := make([]byte, 2)
+	binary.BigEndian.PutUint16(buf, uint16(data))
+	return buf
+}
+
+// portToWire writes port to wire/binary format, 2 bytes
+func portToWire(portStr string) ([]byte, error) {
+
+	port, err := strconv.ParseUint(portStr, 10, 16)
+	if err != nil {
+		return nil, err
+	}
+	return uint16ToWire(uint16(port)), nil
+}