99 lines
2.6 KiB
Go
99 lines
2.6 KiB
Go
// Copyright 2016 The Netstack Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package header
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import (
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"encoding/binary"
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"gvisor.googlesource.com/gvisor/pkg/tcpip"
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)
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// ICMPv4 represents an ICMPv4 header stored in a byte array.
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type ICMPv4 []byte
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const (
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// ICMPv4MinimumSize is the minimum size of a valid ICMP packet.
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ICMPv4MinimumSize = 4
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// ICMPv4EchoMinimumSize is the minimum size of a valid ICMP echo packet.
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ICMPv4EchoMinimumSize = 6
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// ICMPv4DstUnreachableMinimumSize is the minimum size of a valid ICMP
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// destination unreachable packet.
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ICMPv4DstUnreachableMinimumSize = ICMPv4MinimumSize + 4
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// ICMPv4ProtocolNumber is the ICMP transport protocol number.
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ICMPv4ProtocolNumber tcpip.TransportProtocolNumber = 1
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)
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// ICMPv4Type is the ICMP type field described in RFC 792.
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type ICMPv4Type byte
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// Typical values of ICMPv4Type defined in RFC 792.
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const (
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ICMPv4EchoReply ICMPv4Type = 0
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ICMPv4DstUnreachable ICMPv4Type = 3
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ICMPv4SrcQuench ICMPv4Type = 4
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ICMPv4Redirect ICMPv4Type = 5
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ICMPv4Echo ICMPv4Type = 8
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ICMPv4TimeExceeded ICMPv4Type = 11
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ICMPv4ParamProblem ICMPv4Type = 12
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ICMPv4Timestamp ICMPv4Type = 13
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ICMPv4TimestampReply ICMPv4Type = 14
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ICMPv4InfoRequest ICMPv4Type = 15
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ICMPv4InfoReply ICMPv4Type = 16
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)
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// Values for ICMP code as defined in RFC 792.
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const (
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ICMPv4PortUnreachable = 3
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ICMPv4FragmentationNeeded = 4
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)
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// Type is the ICMP type field.
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func (b ICMPv4) Type() ICMPv4Type { return ICMPv4Type(b[0]) }
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// SetType sets the ICMP type field.
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func (b ICMPv4) SetType(t ICMPv4Type) { b[0] = byte(t) }
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// Code is the ICMP code field. Its meaning depends on the value of Type.
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func (b ICMPv4) Code() byte { return b[1] }
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// SetCode sets the ICMP code field.
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func (b ICMPv4) SetCode(c byte) { b[1] = c }
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// Checksum is the ICMP checksum field.
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func (b ICMPv4) Checksum() uint16 {
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return binary.BigEndian.Uint16(b[2:])
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}
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// SetChecksum sets the ICMP checksum field.
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func (b ICMPv4) SetChecksum(checksum uint16) {
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binary.BigEndian.PutUint16(b[2:], checksum)
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}
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// SourcePort implements Transport.SourcePort.
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func (ICMPv4) SourcePort() uint16 {
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return 0
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}
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// DestinationPort implements Transport.DestinationPort.
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func (ICMPv4) DestinationPort() uint16 {
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return 0
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}
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// SetSourcePort implements Transport.SetSourcePort.
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func (ICMPv4) SetSourcePort(uint16) {
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}
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// SetDestinationPort implements Transport.SetDestinationPort.
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func (ICMPv4) SetDestinationPort(uint16) {
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}
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// Payload implements Transport.Payload.
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func (b ICMPv4) Payload() []byte {
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return b[ICMPv4MinimumSize:]
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}
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