| // Copyright 2018 The gVisor Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package header |
| |
| import ( |
| "encoding/binary" |
| |
| "github.com/google/netstack/tcpip" |
| ) |
| |
| // ICMPv4 represents an ICMPv4 header stored in a byte array. |
| type ICMPv4 []byte |
| |
| const ( |
| // ICMPv4MinimumSize is the minimum size of a valid ICMP packet. |
| ICMPv4MinimumSize = 4 |
| |
| // ICMPv4EchoMinimumSize is the minimum size of a valid ICMP echo packet. |
| ICMPv4EchoMinimumSize = 6 |
| |
| // ICMPv4DstUnreachableMinimumSize is the minimum size of a valid ICMP |
| // destination unreachable packet. |
| ICMPv4DstUnreachableMinimumSize = ICMPv4MinimumSize + 4 |
| |
| // ICMPv4ProtocolNumber is the ICMP transport protocol number. |
| ICMPv4ProtocolNumber tcpip.TransportProtocolNumber = 1 |
| ) |
| |
| // ICMPv4Type is the ICMP type field described in RFC 792. |
| type ICMPv4Type byte |
| |
| // Typical values of ICMPv4Type defined in RFC 792. |
| const ( |
| ICMPv4EchoReply ICMPv4Type = 0 |
| ICMPv4DstUnreachable ICMPv4Type = 3 |
| ICMPv4SrcQuench ICMPv4Type = 4 |
| ICMPv4Redirect ICMPv4Type = 5 |
| ICMPv4Echo ICMPv4Type = 8 |
| ICMPv4TimeExceeded ICMPv4Type = 11 |
| ICMPv4ParamProblem ICMPv4Type = 12 |
| ICMPv4Timestamp ICMPv4Type = 13 |
| ICMPv4TimestampReply ICMPv4Type = 14 |
| ICMPv4InfoRequest ICMPv4Type = 15 |
| ICMPv4InfoReply ICMPv4Type = 16 |
| ) |
| |
| // Values for ICMP code as defined in RFC 792. |
| const ( |
| ICMPv4PortUnreachable = 3 |
| ICMPv4FragmentationNeeded = 4 |
| ) |
| |
| // Type is the ICMP type field. |
| func (b ICMPv4) Type() ICMPv4Type { return ICMPv4Type(b[0]) } |
| |
| // SetType sets the ICMP type field. |
| func (b ICMPv4) SetType(t ICMPv4Type) { b[0] = byte(t) } |
| |
| // Code is the ICMP code field. Its meaning depends on the value of Type. |
| func (b ICMPv4) Code() byte { return b[1] } |
| |
| // SetCode sets the ICMP code field. |
| func (b ICMPv4) SetCode(c byte) { b[1] = c } |
| |
| // Checksum is the ICMP checksum field. |
| func (b ICMPv4) Checksum() uint16 { |
| return binary.BigEndian.Uint16(b[2:]) |
| } |
| |
| // SetChecksum sets the ICMP checksum field. |
| func (b ICMPv4) SetChecksum(checksum uint16) { |
| binary.BigEndian.PutUint16(b[2:], checksum) |
| } |
| |
| // SourcePort implements Transport.SourcePort. |
| func (ICMPv4) SourcePort() uint16 { |
| return 0 |
| } |
| |
| // DestinationPort implements Transport.DestinationPort. |
| func (ICMPv4) DestinationPort() uint16 { |
| return 0 |
| } |
| |
| // SetSourcePort implements Transport.SetSourcePort. |
| func (ICMPv4) SetSourcePort(uint16) { |
| } |
| |
| // SetDestinationPort implements Transport.SetDestinationPort. |
| func (ICMPv4) SetDestinationPort(uint16) { |
| } |
| |
| // Payload implements Transport.Payload. |
| func (b ICMPv4) Payload() []byte { |
| return b[ICMPv4MinimumSize:] |
| } |