mirror of
https://github.com/soypat/lneto.git
synced 2026-08-16 04:43:29 +00:00
soypat
139 lines
3.5 KiB
Go
139 lines
3.5 KiB
Go
package icmpv4
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"errors"
|
|
|
|
"github.com/soypat/lneto"
|
|
)
|
|
|
|
type Type uint8
|
|
|
|
const (
|
|
TypeEchoReply Type = 0 // echo reply
|
|
TypeEcho Type = 8 // echo
|
|
|
|
TypeDestinationUnreachable Type = 3 // destination unreachable
|
|
TypeSourceQuench Type = 4 // source quench
|
|
TypeRedirect Type = 5 // redirect
|
|
|
|
TypeTimeExceeded Type = 11 // time exceeded
|
|
TypeParameterProblem Type = 12 // parameter problem
|
|
|
|
TypeTimestamp Type = 13 // timestamp
|
|
TypeTimestampReply Type = 14 // timestamp reply
|
|
|
|
TypeInfoRequest Type = 15 // information request
|
|
TypeInfoRequestReply Type = 16 // information request reply
|
|
)
|
|
|
|
type CodeTimeExceeded uint8
|
|
|
|
const (
|
|
CodeExceededInTransit CodeTimeExceeded = iota // TTL exceeded in transit
|
|
CodeFragmentReassembly // fragment reassembly time exceeded
|
|
)
|
|
|
|
type CodeDestinationUnreachable uint8
|
|
|
|
const (
|
|
CodeNetUnreachable CodeDestinationUnreachable = iota // net unreachable
|
|
CodeHostUnreachable // host unreachable
|
|
CodeProtoUnreachable // protocol unreachable
|
|
CodePortUnreachable // port unreachable
|
|
CodeFragNeededAndDFSet // fragmentation needed and DF set
|
|
CodeSourceRouteFailed // source route failed
|
|
)
|
|
|
|
type CodeRedirect uint8
|
|
|
|
const (
|
|
CodeRedirectForNetwork CodeRedirect = iota // redirect for network
|
|
CodeRedirectForHost // redirect for host
|
|
CodeRedirectForToSAndNetwork // redirect for ToS+network
|
|
CodeRedirectToSAndHost // redirect for ToS+host
|
|
)
|
|
|
|
var (
|
|
errShortFrame = errors.New("icmpv4: short frame")
|
|
)
|
|
|
|
func NewFrame(buf []byte) (Frame, error) {
|
|
if len(buf) < 8 {
|
|
return Frame{}, errShortFrame
|
|
}
|
|
return Frame{buf: buf}, nil
|
|
}
|
|
|
|
type Frame struct {
|
|
buf []byte
|
|
}
|
|
|
|
func (frm Frame) Type() Type { return Type(frm.buf[0]) }
|
|
|
|
func (frm Frame) SetType(t Type) { frm.buf[0] = uint8(t) }
|
|
|
|
func (frm Frame) Code() uint8 { return frm.buf[1] }
|
|
|
|
func (frm Frame) SetCode(code uint8) { frm.buf[1] = code }
|
|
|
|
// CRC returns the checksum field of the frame.
|
|
func (frm Frame) CRC() uint16 {
|
|
return binary.BigEndian.Uint16(frm.buf[2:4])
|
|
}
|
|
|
|
// SetCRC sets the checksum field of the frame.
|
|
func (frm Frame) SetCRC(crc uint16) {
|
|
binary.BigEndian.PutUint16(frm.buf[2:4], crc)
|
|
}
|
|
|
|
// CRCWrite calculates the checksum of the ICMP packet. Treats the checksum field as zero as per RFC 792.
|
|
func (frm Frame) CRCWrite(crc *lneto.CRC791) {
|
|
crc.AddUint16(binary.BigEndian.Uint16(frm.buf[0:2]))
|
|
crc.Write(frm.buf[4:])
|
|
}
|
|
|
|
func (frm Frame) payload() []byte {
|
|
return frm.buf[4:]
|
|
}
|
|
|
|
type FrameDestinationUnreachable struct {
|
|
Frame
|
|
}
|
|
|
|
func (frm FrameDestinationUnreachable) Code() CodeDestinationUnreachable {
|
|
return CodeDestinationUnreachable(frm.Frame.Code())
|
|
}
|
|
|
|
func (frm FrameDestinationUnreachable) SetCode(code CodeDestinationUnreachable) {
|
|
frm.Frame.SetCode(uint8(code))
|
|
}
|
|
|
|
type FrameEcho struct {
|
|
Frame
|
|
}
|
|
|
|
func (frm FrameEcho) Identifier() uint16 {
|
|
return binary.BigEndian.Uint16(frm.buf[4:6])
|
|
}
|
|
|
|
func (frm FrameEcho) SetIdentifier(id uint16) {
|
|
binary.BigEndian.PutUint16(frm.buf[4:6], id)
|
|
}
|
|
|
|
func (frm FrameEcho) SequenceNumber() uint16 {
|
|
return binary.BigEndian.Uint16(frm.buf[6:8])
|
|
}
|
|
|
|
func (frm FrameEcho) SetSequenceNumber(seq uint16) {
|
|
binary.BigEndian.PutUint16(frm.buf[6:8], seq)
|
|
}
|
|
|
|
func (frm FrameEcho) Data() []byte {
|
|
return frm.buf[8:]
|
|
}
|
|
|
|
func (frm FrameEcho) RawData() []byte {
|
|
return frm.buf
|
|
}
|