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|
(* Read in IPv4 and IPv6 ping packets and display them.
* $Id: ping.ml 142 2008-07-17 15:45:56Z richard.wm.jones $
*)
open Printf
let display pkt =
bitmatch pkt with
(* IPv4 packet header *)
| { 4 : 4; hdrlen : 4; tos : 8; length : 16;
identification : 16; flags : 3; fragoffset : 13;
ttl : 8; protocol : 8; checksum : 16;
source : 32;
dest : 32;
options : (hdrlen-5)*32 : bitstring;
payload : -1 : bitstring } ->
printf "IPv4:\n";
printf " header length: %d * 32 bit words\n" hdrlen;
printf " type of service: %d\n" tos;
printf " packet length: %d bytes\n" length;
printf " identification: %d\n" identification;
printf " flags: %d\n" flags;
printf " fragment offset: %d\n" fragoffset;
printf " ttl: %d\n" ttl;
printf " protocol: %d\n" protocol;
printf " checksum: %d\n" checksum;
printf " source: %lx dest: %lx\n" source dest;
printf " header options + padding:\n";
Bitstring.hexdump_bitstring stdout options;
printf " packet payload:\n";
Bitstring.hexdump_bitstring stdout payload
(* IPv6 packet header *)
| { 6 : 4; tclass : 8; flow : 20;
length : 16; nexthdr : 8; ttl : 8;
source : 128 : bitstring;
dest : 128 : bitstring;
payload : -1 : bitstring } ->
printf "IPv6:\n";
printf " traffic class: %d\n" tclass;
printf " flow label: %d\n" flow;
printf " packet (payload) length: %d bytes\n" length;
printf " next header: %d\n" nexthdr;
printf " ttl: %d\n" ttl;
printf " source address:\n";
Bitstring.hexdump_bitstring stdout source;
printf " destination address:\n";
Bitstring.hexdump_bitstring stdout dest;
printf "packet payload:\n";
Bitstring.hexdump_bitstring stdout payload
| { version : 4 } ->
eprintf "unknown IP version %d\n" version;
exit 1
| { _ } as pkt ->
eprintf "data is smaller than one nibble:\n";
Bitstring.hexdump_bitstring stderr pkt;
exit 1
let () =
let pkt = Bitstring.bitstring_of_file "ping.ipv4" in
display pkt;
let pkt = Bitstring.bitstring_of_file "ping.ipv6" in
display pkt
|
