Cooperative email for PDS operators
1// Copyright 2017 Google Inc. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// +build !js
6
7package uuid
8
9import "net"
10
11var interfaces []net.Interface // cached list of interfaces
12
13// getHardwareInterface returns the name and hardware address of interface name.
14// If name is "" then the name and hardware address of one of the system's
15// interfaces is returned. If no interfaces are found (name does not exist or
16// there are no interfaces) then "", nil is returned.
17//
18// Only addresses of at least 6 bytes are returned.
19func getHardwareInterface(name string) (string, []byte) {
20 if interfaces == nil {
21 var err error
22 interfaces, err = net.Interfaces()
23 if err != nil {
24 return "", nil
25 }
26 }
27 for _, ifs := range interfaces {
28 if len(ifs.HardwareAddr) >= 6 && (name == "" || name == ifs.Name) {
29 return ifs.Name, ifs.HardwareAddr
30 }
31 }
32 return "", nil
33}