From: Wejn <lists+rubytalk@...>
Date: 2003-01-29T08:37:32+09:00
Subject: Re: ping with ruby

> For telnet and ftp I have found how to do, but no for ping.

The following source comes from RAA and it's modified by me
(to suit my own needs) ... enjoy :)

#---= begin =---------------------------------------------------------------
#!/usr/bin/env ruby
=begin
 Copyright(c) 2001 arton, under GPL2.
 Modifications and fixes 2003 Wejn <wejn@box.cz>

== SYNOPSIS
 require 'icmpping'
 result = ICMPPing.ping hostname [, timeout(millisecs) [, packetsize(<1024)]]

== Return Value

 -1 : Any Socket Error
 -2 : Timeout
 -3 : Not root
 >=0: round trip time (in milliseconds)

== Notes
 Only Linux now supported
 You must be root
 Miliseconds now work correctly
 Only a class now
 
=end

require 'socket'
require 'timeout'

class ICMPPing
  IPPROTO_ICMP = 1
  ICMP_ECHO = 8
  ICMP_ECHOREPLY = 0
  DEF_PACKET_SIZE = 64
  MAX_PACKET_SIZE = 1024

  def ICMPPing.ping(host, timeout = 1000, dlen = self::DEF_PACKET_SIZE)
    begin
      raise ArgumentError, "Packet too long" if dlen > MAX_PACKET_SIZE
      hp = [Socket::AF_INET, 0, Socket.gethostbyname(host)[3], 0, 0]
      s = Socket.new(Socket::AF_INET, Socket::SOCK_RAW, IPPROTO_ICMP)
    rescue Errno::EPERM
      $stderr.puts "Error: #{$!.message}" if $VERBOSE
      return -3
    rescue
      $stderr.puts "Error: #{$!.message}" if $VERBOSE
      return -1
    end

    start = Time.now.to_f * 1000
    id = $$ & 0xffff
    icmph = [ ICMP_ECHO, 0, 0, id, 0, start.to_i & 0xffffffff, nil ]
    icmph[6] = "E" * dlen
    dat = icmph.pack("C2n3Na*")
    cksum = checksum(((dat.length & 1) ? (dat + "\0") : dat).unpack("n*"))
    dat[2], dat[3] = cksum >> 8, cksum & 0xff
    begin
      s.send dat, 0, hp.pack("v2a*N2")
      timeout(timeout / 1000.0) do
        while true
          rdat = s.recvfrom(self::MAX_PACKET_SIZE + 500)
          icmpdat = rdat[0].slice((rdat[0][0] & 0x0f) * 4..-1)
          resp = icmpdat.unpack("C2n3N")
          next if resp[0] != ICMP_ECHOREPLY || resp[3] != id
          break
        end
      end
    rescue TimeoutError
      $stderr.puts "Error: #{$!.message}" if $VERBOSE
      return -2
    rescue
      $stderr.puts "Error: #{$!.message}" if $VERBOSE
      return -1
    end

    Time.now.to_f * 1000 - start
  end

  def ICMPPing.checksum(n)
    ck = 0
    n.each{ |v| ck += v }
    ck = (ck >> 16) + (ck & 0xffff)
    ck += ck >> 16
    ~ck
  end
end

if $0 == __FILE__
  if ARGV.empty?
    print "usage: icmpping.rb <host> [timeout(ms=2000)]\n"
    exit 1
  end
  $VERBOSE = true
  rd = ICMPPing.ping(ARGV[0], (ARGV[1] || "2000").to_i)
  if rd < 0
    exit rd.abs
  else
    puts "#{ICMPPing::DEF_PACKET_SIZE} bytes, rtt: #{rd} msec"
  end
end
#---=  end  =---------------------------------------------------------------

W.
-- 
              Wejn <lists+rubytalk(at)box.cz>
(svamberk.net's Linux section, fi.muni.cz student, linuxfan)
>>>         Bored?  Want hours of entertainment?         <<<
>>>           Just set the initdefault to 6!             <<<