Block diagram
This page hosts a formal specification of ICMP network packet using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
meta:
id: icmp_packet
title: ICMP network packet
xref:
rfc: 792
wikidata: Q13162
license: CC0-1.0
endian: be
seq:
- id: icmp_type
type: u1
enum: icmp_type_enum
- id: destination_unreachable
type: destination_unreachable_msg
if: icmp_type == icmp_type_enum::destination_unreachable
- id: time_exceeded
type: time_exceeded_msg
if: icmp_type == icmp_type_enum::time_exceeded
- id: echo
type: echo_msg
if: icmp_type == icmp_type_enum::echo or icmp_type == icmp_type_enum::echo_reply
enums:
icmp_type_enum:
0: echo_reply
3: destination_unreachable
4: source_quench
5: redirect
8: echo
11: time_exceeded
types:
destination_unreachable_msg:
seq:
- id: code
type: u1
enum: destination_unreachable_code
- id: checksum
type: u2
enums:
destination_unreachable_code:
0: net_unreachable
1: host_unreachable
2: protocol_unreachable
3: port_unreachable
4: fragmentation_needed_and_df_set
5: source_route_failed
6: dst_net_unkown
7: sdt_host_unkown
8: src_isolated
9: net_prohibited_by_admin
10: host_prohibited_by_admin
11: net_unreachable_for_tos
12: host_unreachable_for_tos
13: communication_prohibited_by_admin
14: host_precedence_violation
15: precedence_cuttoff_in_effect
time_exceeded_msg:
seq:
- id: code
type: u1
enum: time_exceeded_code
- id: checksum
type: u2
enums:
time_exceeded_code:
0: time_to_live_exceeded_in_transit
1: fragment_reassembly_time_exceeded
echo_msg:
seq:
- id: code
contents: [0]
- id: checksum
type: u2
- id: identifier
type: u2
- id: seq_num
type: u2
- id: data
size-eos: true