// SerializeTo writes the serialized form of this layer into the
// SerializationBuffer, implementing gopacket.SerializableLayer.
// See the docs for gopacket.SerializableLayer for more info.
func (u *UDP) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
payload := b.Bytes()
bytes, err := b.PrependBytes(8)
if err != nil {
return err
}
binary.BigEndian.PutUint16(bytes, uint16(u.SrcPort))
binary.BigEndian.PutUint16(bytes[2:], uint16(u.DstPort))
if opts.FixLengths {
u.Length = uint16(len(payload)) + 8
}
binary.BigEndian.PutUint16(bytes[4:], u.Length)
if opts.ComputeChecksums {
// zero out checksum bytes
bytes[6] = 0
bytes[7] = 0
csum, err := u.computeChecksum(b.Bytes())
if err != nil {
return err
}
u.Checksum = csum
}
binary.BigEndian.PutUint16(bytes[6:], u.Checksum)
return nil
}
// SerializeTo writes the serialized form of this layer into the
// SerializationBuffer, implementing gopacket.SerializableLayer.
// See the docs for gopacket.SerializableLayer for more info.
func (ip6 *IPv6) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
payload := b.Bytes()
if ip6.HopByHop != nil {
return fmt.Errorf("unable to serialize hopbyhop for now")
}
bytes, err := b.PrependBytes(40)
if err != nil {
return err
}
bytes[0] = (ip6.Version << 4) | (ip6.TrafficClass >> 4)
bytes[1] = (ip6.TrafficClass << 4) | uint8(ip6.FlowLabel>>16)
binary.BigEndian.PutUint16(bytes[2:], uint16(ip6.FlowLabel))
if opts.FixLengths {
ip6.Length = uint16(len(payload))
}
binary.BigEndian.PutUint16(bytes[4:], ip6.Length)
bytes[6] = byte(ip6.NextHeader)
bytes[7] = byte(ip6.HopLimit)
if len(ip6.SrcIP) != 16 {
return fmt.Errorf("invalid src ip %v", ip6.SrcIP)
}
if len(ip6.DstIP) != 16 {
return fmt.Errorf("invalid dst ip %v", ip6.DstIP)
}
copy(bytes[8:], ip6.SrcIP)
copy(bytes[24:], ip6.DstIP)
return nil
}
// SerializeTo writes the serialized form of this layer into the
// SerializationBuffer, implementing gopacket.SerializableLayer.
// See the docs for gopacket.SerializableLayer for more info.
func (t *TCP) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
var optionLength int
for _, o := range t.Options {
switch o.OptionType {
case 0, 1:
optionLength += 1
default:
optionLength += 2 + len(o.OptionData)
}
}
if opts.FixLengths {
t.Padding = lotsOfZeros[:optionLength%4]
t.DataOffset = uint8((len(t.Padding) + optionLength + 20) / 4)
}
bytes, err := b.PrependBytes(20 + optionLength + len(t.Padding))
if err != nil {
return err
}
binary.BigEndian.PutUint16(bytes, uint16(t.SrcPort))
binary.BigEndian.PutUint16(bytes[2:], uint16(t.DstPort))
binary.BigEndian.PutUint32(bytes[4:], t.Seq)
binary.BigEndian.PutUint32(bytes[8:], t.Ack)
binary.BigEndian.PutUint16(bytes[12:], t.flagsAndOffset())
binary.BigEndian.PutUint16(bytes[14:], t.Window)
binary.BigEndian.PutUint16(bytes[18:], t.Urgent)
start := 20
for _, o := range t.Options {
bytes[start] = o.OptionType
switch o.OptionType {
case 0, 1:
start++
default:
if opts.FixLengths {
o.OptionLength = uint8(len(o.OptionData) + 2)
}
bytes[start+1] = o.OptionLength
copy(bytes[start+2:start+len(o.OptionData)+2], o.OptionData)
start += int(o.OptionLength)
}
}
copy(bytes[start:], t.Padding)
if opts.ComputeChecksums {
// zero out checksum bytes in current serialization.
bytes[16] = 0
bytes[17] = 0
csum, err := t.computeChecksum(b.Bytes())
if err != nil {
return err
}
t.Checksum = csum
}
binary.BigEndian.PutUint16(bytes[16:], t.Checksum)
return nil
}
// SerializeTo writes the serialized form of this layer into the
// SerializationBuffer, implementing gopacket.SerializableLayer.
// See the docs for gopacket.SerializableLayer for more info.
func (p *PPPoE) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
payload := b.Bytes()
bytes, err := b.PrependBytes(6)
if err != nil {
return err
}
bytes[0] = (p.Version << 4) | p.Type
bytes[1] = byte(p.Code)
binary.BigEndian.PutUint16(bytes[2:], p.SessionId)
if opts.FixLengths {
p.Length = uint16(len(payload))
}
binary.BigEndian.PutUint16(bytes[4:], p.Length)
return nil
}
// SerializeTo is for gopacket.SerializableLayer.
func (s SCTP) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
bytes, err := b.PrependBytes(12)
if err != nil {
return err
}
binary.BigEndian.PutUint16(bytes[0:2], uint16(s.SrcPort))
binary.BigEndian.PutUint16(bytes[2:4], uint16(s.DstPort))
binary.BigEndian.PutUint32(bytes[4:8], s.VerificationTag)
if opts.ComputeChecksums {
// Note: MakeTable(Castagnoli) actually only creates the table once, then
// passes back a singleton on every other call, so this shouldn't cause
// excessive memory allocation.
binary.LittleEndian.PutUint32(bytes[8:12], crc32.Checksum(b.Bytes(), crc32.MakeTable(crc32.Castagnoli)))
}
return nil
}
// SerializeTo writes the serialized form of this layer into the
// SerializationBuffer, implementing gopacket.SerializableLayer.
// See the docs for gopacket.SerializableLayer for more info.
func (i *ICMPv4) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
bytes, err := b.PrependBytes(8)
if err != nil {
return err
}
binary.BigEndian.PutUint16(bytes, uint16(i.TypeCode))
binary.BigEndian.PutUint16(bytes[4:], i.Id)
binary.BigEndian.PutUint16(bytes[6:], i.Seq)
if opts.ComputeChecksums {
bytes[2] = 0
bytes[3] = 0
i.Checksum = tcpipChecksum(b.Bytes(), 0)
}
binary.BigEndian.PutUint16(bytes[2:], i.Checksum)
return nil
}
// SerializeTo writes the serialized form of this layer into the
// SerializationBuffer, implementing gopacket.SerializableLayer.
func (ip *IPv4) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
if len(ip.Options) > 0 {
return fmt.Errorf("cannot currently serialize IPv4 options")
}
bytes, err := b.PrependBytes(20)
if err != nil {
return err
}
if opts.FixLengths {
ip.IHL = 5 // Fix when we add support for options.
ip.Length = uint16(len(b.Bytes()))
}
bytes[0] = (ip.Version << 4) | ip.IHL
bytes[1] = ip.TOS
binary.BigEndian.PutUint16(bytes[2:], ip.Length)
binary.BigEndian.PutUint16(bytes[4:], ip.Id)
binary.BigEndian.PutUint16(bytes[6:], ip.flagsfrags())
bytes[8] = ip.TTL
bytes[9] = byte(ip.Protocol)
if len(ip.SrcIP) != 4 {
return fmt.Errorf("invalid src IP %v", ip.SrcIP)
}
if len(ip.DstIP) != 4 {
return fmt.Errorf("invalid dst IP %v", ip.DstIP)
}
copy(bytes[12:16], ip.SrcIP)
copy(bytes[16:20], ip.DstIP)
if opts.ComputeChecksums {
// Clear checksum bytes
bytes[10] = 0
bytes[11] = 0
// Compute checksum
var csum uint32
for i := 0; i < len(bytes); i += 2 {
csum += uint32(bytes[i]) << 8
csum += uint32(bytes[i+1])
}
ip.Checksum = ^uint16((csum >> 16) + csum)
}
binary.BigEndian.PutUint16(bytes[10:], ip.Checksum)
return nil
}
// 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
}
// SerializeTo writes the serialized form of this layer into the
// SerializationBuffer, implementing gopacket.SerializableLayer.
// See the docs for gopacket.SerializableLayer for more info.
func (i *ICMPv6) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
if i.TypeBytes == nil {
i.TypeBytes = lotsOfZeros[:4]
} else if len(i.TypeBytes) != 4 {
return fmt.Errorf("invalid type bytes for ICMPv6 packet: %v", i.TypeBytes)
}
bytes, err := b.PrependBytes(8)
if err != nil {
return err
}
binary.BigEndian.PutUint16(bytes, uint16(i.TypeCode))
copy(bytes[4:8], i.TypeBytes)
if opts.ComputeChecksums {
bytes[2] = 0
bytes[3] = 0
csum, err := i.computeChecksum(b.Bytes())
if err != nil {
return err
}
i.Checksum = csum
}
binary.BigEndian.PutUint16(bytes[2:], i.Checksum)
return nil
}
