// SerializeTo writes the serialized form of this layer into the
// SerializationBuffer, implementing gopacket.SerializableLayer.
// See the docs for gopacket.SerializableLayer for more info.
func (eth *Ethernet) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
if len(eth.DstMAC) != 6 {
return fmt.Errorf("invalid dst MAC: %v", eth.DstMAC)
}
if len(eth.SrcMAC) != 6 {
return fmt.Errorf("invalid src MAC: %v", eth.SrcMAC)
}
payload := b.Bytes()
bytes, err := b.PrependBytes(14)
if err != nil {
return err
}
copy(bytes, eth.DstMAC)
copy(bytes[6:], eth.SrcMAC)
if eth.Length != 0 || eth.EthernetType == EthernetTypeLLC {
if opts.FixLengths {
eth.Length = uint16(len(payload))
}
if eth.EthernetType != EthernetTypeLLC {
return fmt.Errorf("ethernet type %v not compatible with length value %v", eth.EthernetType, eth.Length)
} else if eth.Length > 0x0600 {
return fmt.Errorf("invalid ethernet length %v", eth.Length)
}
binary.BigEndian.PutUint16(bytes[12:], eth.Length)
} else {
binary.BigEndian.PutUint16(bytes[12:], uint16(eth.EthernetType))
}
length := len(b.Bytes())
if length < 60 {
// Pad out to 60 bytes.
padding, err := b.AppendBytes(60 - length)
if err != nil {
return err
}
copy(padding, lotsOfZeros[:])
}
return nil
}
