blob: afbf24f1bab3357c1f5b719f169836f63c1064fe [file] [log] [blame]
// Copyright 2014 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 icmp
import "encoding/binary"
// A PacketTooBig represents an ICMP packet too big message body.
type PacketTooBig struct {
MTU int // maximum transmission unit of the nexthop link
Data []byte // data, known as original datagram field
// Len implements the Len method of MessageBody interface.
func (p *PacketTooBig) Len(proto int) int {
if p == nil {
return 0
return 4 + len(p.Data)
// Marshal implements the Marshal method of MessageBody interface.
func (p *PacketTooBig) Marshal(proto int) ([]byte, error) {
b := make([]byte, 4+len(p.Data))
binary.BigEndian.PutUint32(b[:4], uint32(p.MTU))
copy(b[4:], p.Data)
return b, nil
// parsePacketTooBig parses b as an ICMP packet too big message body.
func parsePacketTooBig(proto int, _ Type, b []byte) (MessageBody, error) {
bodyLen := len(b)
if bodyLen < 4 {
return nil, errMessageTooShort
p := &PacketTooBig{MTU: int(binary.BigEndian.Uint32(b[:4]))}
if bodyLen > 4 {
p.Data = make([]byte, bodyLen-4)
copy(p.Data, b[4:])
return p, nil