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authorPatricio Whittingslow <[email protected]>2021-06-29 22:16:21 -0300
committerRon Evans <[email protected]>2021-07-02 18:49:14 +0200
commit42785e08e88dcbcfbbb36e6b12f081de16c86093 (patch)
tree8cacb2522fb138ee70d4b0a88a131616739dd214 /src/net
parent2d633e3a28b11254fc5bf643c1730bd5759c69c6 (diff)
downloadtinygo-42785e08e88dcbcfbbb36e6b12f081de16c86093.tar.gz
tinygo-42785e08e88dcbcfbbb36e6b12f081de16c86093.zip
add MAC address implementation to net
Diffstat (limited to 'src/net')
-rw-r--r--src/net/mac.go90
1 files changed, 90 insertions, 0 deletions
diff --git a/src/net/mac.go b/src/net/mac.go
index 13f505192..ea3b921f0 100644
--- a/src/net/mac.go
+++ b/src/net/mac.go
@@ -7,3 +7,93 @@
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 err
+ }
+
+ if s[2] == ':' || s[2] == '-' {
+ if (len(s)+1)%3 != 0 {
+ goto err
+ }
+ n := (len(s) + 1) / 3
+ if n != 6 && n != 8 && n != 20 {
+ goto err
+ }
+ 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 err
+ }
+ x += 3
+ }
+ } else if s[4] == '.' {
+ if (len(s)+1)%5 != 0 {
+ goto err
+ }
+ n := 2 * (len(s) + 1) / 5
+ if n != 6 && n != 8 && n != 20 {
+ goto err
+ }
+ 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 err
+ }
+ if hw[i+1], ok = xtoi2(s[x+2:], s[4]); !ok {
+ goto err
+ }
+ x += 5
+ }
+ } else {
+ goto err
+ }
+ return hw, nil
+
+err:
+ return nil, &AddrError{Err: "invalid MAC address", Addr: s}
+}
+
+// xtoi2 converts the next two hex digits of s into a byte.
+// If s is longer than 2 bytes then the third byte must be e.
+// If the first two bytes of s are not hex digits or the third byte
+// does not match e, false is returned.
+func xtoi2(s string, e byte) (byte, bool) {
+ if len(s) > 2 && s[2] != e {
+ return 0, false
+ }
+ n, ei, ok := xtoi(s[:2])
+ return byte(n), ok && ei == 2
+}