1 files changed, 85 insertions, 0 deletions
diff --git a/src/net/mac.go b/src/net/mac.go
new file mode 100644
index 0000000..373ac3d
--- /dev/null
+++ b/src/net/mac.go
@@ -0,0 +1,85 @@
+// 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}
+}