Qmail-greyd

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#!/usr/bin/python

# Before running this script make sure to have done :
# mkdir /var/qmail/grey
# chown qmaild.nofiles /var/qmail/grey
# test with env TCPREMOTEIP="127.0.0.1" GREY="" ./greyd /bin/bash -c env | grep RB
# and do not forget to delete the folder and file created before going in production
# Design similar to http://www.jonatkins.com/page/software/qgreylist

import os
import sys
import time

minute = 60
hour = 60*60
day = 60*60*24

# Configuration start

config = {}
config['WAITING'] = 1*minute		# How long should a sender wait before being allowed
config['LAST_SEEN'] = 32*day		# How long before we clean IP which have sent several time
config['FIRST_SEEN'] = 5*day		# How long before we clean IP which have seen one time only
config['CLEANUP'] = 20*minute		# How often we cleanup the IPS
config['BASE'] = os.path.join('/','var','qmail','grey')

log_per_ip = True			# Log per IP (true) or per Class C (false)

# Configuration end

def log (*param):
	sys.stderr.write('greyd: ')
	sys.stderr.write(*param)
	sys.stderr.write('\n')
	sys.stderr.flush()

def out (code,*param):
	log(*param)
	sys.exit(code)

def run_next ():
	if len(sys.argv) > 1:
		try:
			prog = sys.argv[1]
			param = sys.argv[1:]
			os.execve(prog,param,os.environ)
		except:
			out(1,"issue whish trying to exec %s" % prog)
	else:
		out(1,"can not execute the smtp application")

def cleanup ():
	global config
	
	try:
		filename = os.path.join(config['BASE'],'clean')
		last_clean = os.path.getmtime(filename)
	except:
		try:
			open(filename,'w').close()
		except:
			log('can not create the timestamp file (%s) used for cleanup' % filename)
		return

	try:
		now = time.time()
		if now - last_clean > config['CLEANUP']:
			log('running cleanup')
			open(filename,'w').close()
			for root, dirs, files in os.walk(config['BASE'], topdown=False):
				if not dirs:
					for file in  files:
						filename = os.path.join(root,file)
						#log('checking %s' % filename)
						try:
							ctime = os.path.getctime(filename)
							mtime = os.path.getmtime(filename)

							deltac = now - ctime
							deltam = now - mtime
						except:
							log('%s must have been deleted by another process' % filename)
							continue
						try:
							# You sent us one mail 5 days ago, bye, bye
							if ctime == mtime :
								if deltac > config['FIRST_SEEN']:
									os.unlink(filename)
									log('removed inactive one off sender %s' % filename)
							# You sent us several mails 32 days ago, bye, bye
							else:
								if deltam > config['LAST_SEEN']:
									os.unlink(filename)
									log('removed inactive sender %s' % filename)
						except:
							log('could not cleanup %s' % filename)
							continue
	except:
		log('problem with cleanup')

# Main

# Get all environment variable

remote_ip = os.environ.get('TCPREMOTEIP')
if remote_ip == None:
	# should never happen
	out(1,"Can not get TCPREMOTEIP from environment")

if os.environ.get('GREY') == None:
	run_next()

if os.environ.get('RELAYCLIENT') != None:
	sys.stderr.write('Both GREY and RELAYCLIENT set for the same IP : %s' % remote_ip)
	os.environ['RBLSMTPD'] = ''
	run_next()

# Build the name of the file to check

ips = remote_ip.split('.')
foldername = config['BASE']

foldername = os.path.join(foldername,ips[0],ips[1])
filename = os.path.join(foldername,ips[2])

if log_per_ip:
	filename += "-" + ips[3]

# Check time and perform according action

try:
	now = time.time()

	last_seen = os.path.getmtime(filename)
	first_seen = os.path.getctime(filename)
	
	delta_last = now - last_seen
	delta_first = now - first_seen
except:
	try:
		os.makedirs(foldername,0700)
	except:
		# The folder most likely already exist
		pass
	try:
		open(filename,'w').close()
		os.environ['RBLSMTPD'] = 'greylisting, IP %s time -' % remote_ip
	except:
		log('issue trying the initial touching of the file %s (or creating the folder)' % filename)
	cleanup()
	run_next()

# if you never waited two minutes without sending
if delta_first < config['WAITING']:
	try:
		os.unlink(filename)
		open(filename,'w').close()
		os.environ['RBLSMTPD'] = 'greylisting, IP %s time %d' % (remote_ip,int(delta_last))
	except:
		log('issue with touching file %s' % filename)
	cleanup()
	run_next()
	
# deliver valid email
run_next()