diff options
Diffstat (limited to 'pkg/tcpip/header/icmpv4.go')
| -rw-r--r-- | pkg/tcpip/header/icmpv4.go | 57 |
1 files changed, 47 insertions, 10 deletions
diff --git a/pkg/tcpip/header/icmpv4.go b/pkg/tcpip/header/icmpv4.go index 1a631b31a..504408878 100644 --- a/pkg/tcpip/header/icmpv4.go +++ b/pkg/tcpip/header/icmpv4.go @@ -31,6 +31,27 @@ const ( // ICMPv4MinimumSize is the minimum size of a valid ICMP packet. ICMPv4MinimumSize = 8 + // ICMPv4MinimumErrorPayloadSize Is the smallest number of bytes of an + // errant packet's transport layer that an ICMP error type packet should + // attempt to send as per RFC 792 (see each type) and RFC 1122 + // section 3.2.2 which states: + // Every ICMP error message includes the Internet header and at + // least the first 8 data octets of the datagram that triggered + // the error; more than 8 octets MAY be sent; this header and data + // MUST be unchanged from the received datagram. + // + // RFC 792 shows: + // 0 1 2 3 + // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + // | Type | Code | Checksum | + // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + // | unused | + // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + // | Internet Header + 64 bits of Original Data Datagram | + // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + ICMPv4MinimumErrorPayloadSize = 8 + // ICMPv4ProtocolNumber is the ICMP transport protocol number. ICMPv4ProtocolNumber tcpip.TransportProtocolNumber = 1 @@ -39,21 +60,28 @@ const ( icmpv4ChecksumOffset = 2 // icmpv4MTUOffset is the offset of the MTU field - // in a ICMPv4FragmentationNeeded message. + // in an ICMPv4FragmentationNeeded message. icmpv4MTUOffset = 6 // icmpv4IdentOffset is the offset of the ident field - // in a ICMPv4EchoRequest/Reply message. + // in an ICMPv4EchoRequest/Reply message. icmpv4IdentOffset = 4 + // icmpv4PointerOffset is the offset of the pointer field + // in an ICMPv4ParamProblem message. + icmpv4PointerOffset = 4 + // icmpv4SequenceOffset is the offset of the sequence field - // in a ICMPv4EchoRequest/Reply message. + // in an ICMPv4EchoRequest/Reply message. icmpv4SequenceOffset = 6 ) // ICMPv4Type is the ICMP type field described in RFC 792. type ICMPv4Type byte +// ICMPv4Code is the ICMP code field described in RFC 792. +type ICMPv4Code byte + // Typical values of ICMPv4Type defined in RFC 792. const ( ICMPv4EchoReply ICMPv4Type = 0 @@ -69,14 +97,23 @@ const ( ICMPv4InfoReply ICMPv4Type = 16 ) -// Values for ICMP code as defined in RFC 792. +// ICMP codes for ICMPv4 Time Exceeded messages as defined in RFC 792. const ( - ICMPv4TTLExceeded = 0 - ICMPv4HostUnreachable = 1 - ICMPv4PortUnreachable = 3 - ICMPv4FragmentationNeeded = 4 + ICMPv4TTLExceeded ICMPv4Code = 0 ) +// ICMP codes for ICMPv4 Destination Unreachable messages as defined in RFC 792. +const ( + ICMPv4NetUnreachable ICMPv4Code = 0 + ICMPv4HostUnreachable ICMPv4Code = 1 + ICMPv4ProtoUnreachable ICMPv4Code = 2 + ICMPv4PortUnreachable ICMPv4Code = 3 + ICMPv4FragmentationNeeded ICMPv4Code = 4 +) + +// ICMPv4UnusedCode is a code to use in ICMP messages where no code is needed. +const ICMPv4UnusedCode ICMPv4Code = 0 + // Type is the ICMP type field. func (b ICMPv4) Type() ICMPv4Type { return ICMPv4Type(b[0]) } @@ -84,10 +121,10 @@ func (b ICMPv4) Type() ICMPv4Type { return ICMPv4Type(b[0]) } 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] } +func (b ICMPv4) Code() ICMPv4Code { return ICMPv4Code(b[1]) } // SetCode sets the ICMP code field. -func (b ICMPv4) SetCode(c byte) { b[1] = c } +func (b ICMPv4) SetCode(c ICMPv4Code) { b[1] = byte(c) } // Checksum is the ICMP checksum field. func (b ICMPv4) Checksum() uint16 { |