ICMP¶
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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
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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
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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
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class
ryu.lib.packet.icmp.icmp(type_=8, code=0, csum=0, data=b'')¶ 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. -
classmethod
parser(buf)¶ Decode a protocol header.
This method is used only when decoding a packet.
Decode a protocol header at offset 0 in bytearray buf. Returns the following three objects.
- An object to describe the decoded header.
- A packet_base.PacketBase subclass appropriate for the rest of the packet. None when the rest of the packet should be considered as raw payload.
- The rest of packet.
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serialize(payload, prev)¶ Encode a protocol header.
This method is used only when encoding a packet.
Encode a protocol header. Returns a bytearray which contains the header.
payload is the rest of the packet which will immediately follow this header.
prev is a packet_base.PacketBase subclass for the outer protocol header. prev is None if the current header is the outer-most. For example, prev is ipv4 or ipv6 for tcp.serialize.
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classmethod