ICMP

class ryu.lib.packet.icmp.TimeExceeded(data_len=0, data=None)

ICMP sub encoder/decoder class for Time Exceeded Message.

This is used with ryu.lib.packet.icmp.icmp for ICMP Time Exceeded Message.

An instance has the following attributes at least. Most of them are same to the on-wire counterparts but in host byte order. __init__ takes the corresponding args in this order.

[RFC4884] introduced 8-bit data length attribute.

Attribute Description
data_len data length
data Internet Header + leading octets of original datagram
class ryu.lib.packet.icmp.dest_unreach(data_len=0, mtu=0, data=None)

ICMP sub encoder/decoder class for Destination Unreachable Message.

This is used with ryu.lib.packet.icmp.icmp for ICMP Destination Unreachable Message.

An instance has the following attributes at least. Most of them are same to the on-wire counterparts but in host byte order. __init__ takes the corresponding args in this order.

[RFC1191] reserves bits for the "Next-Hop MTU" field. [RFC4884] introduced 8-bit data length attribute.

Attribute Description
data_len data length
mtu

Next-Hop MTU

NOTE: This field is required when icmp code is 4

code 4 = fragmentation needed and DF set

data Internet Header + leading octets of original datagram
class ryu.lib.packet.icmp.echo(id_=0, seq=0, data=None)

ICMP sub encoder/decoder class for Echo and Echo Reply messages.

This is used with ryu.lib.packet.icmp.icmp for ICMP Echo and Echo Reply messages.

An instance has the following attributes at least. Most of them are same to the on-wire counterparts but in host byte order. __init__ takes the corresponding args in this order.

Attribute Description
id Identifier
seq Sequence Number
data Internet Header + 64 bits of Original Data Datagram
class ryu.lib.packet.icmp.icmp(type_=8, code=0, csum=0, data=None)

ICMP (RFC 792) header encoder/decoder class.

An instance has the following attributes at least. Most of them are same to the on-wire counterparts but in host byte order. __init__ takes the corresponding args in this order.

Attribute Description
type Type
code Code
csum CheckSum (0 means automatically-calculate when encoding)
data Payload. Either a bytearray, or ryu.lib.packet.icmp.echo or ryu.lib.packet.icmp.dest_unreach or ryu.lib.packet.icmp.TimeExceeded object NOTE for icmp.echo: This includes "unused" 16 bits and the following "Internet Header + 64 bits of Original Data Datagram" of the ICMP header. NOTE for icmp.dest_unreach and icmp.TimeExceeded: This includes "unused" 8 or 24 bits and the following "Internet Header + leading octets of original datagram" of the original packet.