| // 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. |
| |
| // MAC address manipulations |
| |
| package net |
| |
| import ( |
| "bytes" |
| "errors" |
| "fmt" |
| ) |
| |
| // A HardwareAddr represents a physical hardware address. |
| type HardwareAddr []byte |
| |
| func (a HardwareAddr) String() string { |
| var buf bytes.Buffer |
| for i, b := range a { |
| if i > 0 { |
| buf.WriteByte(':') |
| } |
| fmt.Fprintf(&buf, "%02x", b) |
| } |
| return buf.String() |
| } |
| |
| // ParseMAC parses s as an IEEE 802 MAC-48, EUI-48, or EUI-64 using one of the |
| // following formats: |
| // 01:23:45:67:89:ab |
| // 01:23:45:67:89:ab:cd:ef |
| // 01-23-45-67-89-ab |
| // 01-23-45-67-89-ab-cd-ef |
| // 0123.4567.89ab |
| // 0123.4567.89ab.cdef |
| 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 { |
| 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 { |
| 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, errors.New("invalid MAC address: " + s) |
| } |