// Copyright 2011 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package net const hexDigit = "0123456789abcdef" // A HardwareAddr represents a physical hardware address. type HardwareAddr []byte func (a HardwareAddr) String() string { if len(a) == 0 { return "" } buf := make([]byte, 0, len(a)*3-1) for i, b := range a { if i > 0 { buf = append(buf, ':') } buf = append(buf, hexDigit[b>>4]) buf = append(buf, hexDigit[b&0xF]) } return string(buf) } // ParseMAC parses s as an IEEE 802 MAC-48, EUI-48, EUI-64, or a 20-octet // IP over InfiniBand link-layer address using one of the following formats: // // 00:00:5e:00:53:01 // 02:00:5e:10:00:00:00:01 // 00:00:00:00:fe:80:00:00:00:00:00:00:02:00:5e:10:00:00:00:01 // 00-00-5e-00-53-01 // 02-00-5e-10-00-00-00-01 // 00-00-00-00-fe-80-00-00-00-00-00-00-02-00-5e-10-00-00-00-01 // 0000.5e00.5301 // 0200.5e10.0000.0001 // 0000.0000.fe80.0000.0000.0000.0200.5e10.0000.0001 func ParseMAC(s string) (hw HardwareAddr, err error) { if len(s) < 14 { goto error } if s[2] == ':' || s[2] == '-' { if (len(s)+1)%3 != 0 { goto error } n := (len(s) + 1) / 3 if n != 6 && n != 8 && n != 20 { goto error } hw = make(HardwareAddr, n) for x, i := 0, 0; i < n; i++ { var ok bool if hw[i], ok = xtoi2(s[x:], s[2]); !ok { goto error } x += 3 } } else if s[4] == '.' { if (len(s)+1)%5 != 0 { goto error } n := 2 * (len(s) + 1) / 5 if n != 6 && n != 8 && n != 20 { goto error } hw = make(HardwareAddr, n) for x, i := 0, 0; i < n; i += 2 { var ok bool if hw[i], ok = xtoi2(s[x:x+2], 0); !ok { goto error } if hw[i+1], ok = xtoi2(s[x+2:], s[4]); !ok { goto error } x += 5 } } else { goto error } return hw, nil error: return nil, &AddrError{Err: "invalid MAC address", Addr: s} }