#!/usr/bin/ruby

$logfile = 'fake-rexec.log'

def readstrz fd
	ret = ''
	loop do
		chr = fd.read 1 rescue nil
		break ret if not chr or chr[0] == 0
		ret << chr
	end
end
			
def handle_rexec fd
	File.open($logfile, 'a') { |logfd|
		logfd.print Time.now.strftime('%d/%m %H:%M:%S ')

		proto, port, *ip = fd.getpeername.unpack('Sn'+'C'*255).compact rescue nil
		ip = case proto
			when nil
			when 2
				ip[0..3].join '.'
			when 10
				ip = ip[4..19]
				if ip[0..11] == [0]*10 + [255, 255]
					'::ffff:' + ip[12..15].join('.')
				else
					p = 0
					ip.map { |i| p += 1 ; "%.2x#{':' if (p & 3) == 0 and p < 13 }" % i }.join.sub(/(^|:)[0:]*/, '::')
				end
			else
				ip.inspect
			end
			
		logfd.print "#{ip}:#{port} "
		
		stderr = readstrz fd
		user = readstrz fd
		pass = readstrz fd
		cmd = readstrz fd
		logfd.puts [stderr, user, pass, cmd].inspect
	}
end

if ARGV.include? '--standalone'
	require 'socket'
	s=TCPServer.new(512)
	loop do
		a = s.accept
		handle_rexec a
		a.shutdown
		a.close
	end
else
	handle_rexec $stdin
end