| divyadesai | 81bb7ba | 2020-03-11 11:45:23 +0000 | [diff] [blame^] | 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 | |
| 7 | package uuid |
| 8 | |
| 9 | import "net" |
| 10 | |
| 11 | var 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. |
| 19 | func 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 | } |