root / pykota / trunk / bin / lprngpykota @ 2403

#! /usr/bin/env python
# -*- coding: ISO-8859-15 -*-

# LPRngPyKota accounting filter
#
# PyKota - Print Quotas for CUPS and LPRng
#
# (c) 2003, 2004, 2005 Jerome Alet <alet@librelogiciel.com>
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# $Id$
#
#

import sys
import os

from pykota.tool import PyKotaFilterOrBackend, PyKotaToolError, crashed
from pykota.config import PyKotaConfigError
from pykota.storage import PyKotaStorageError
from pykota.accounter import PyKotaAccounterError
    
# Exit codes
JSUCC = 0       # filter succeeded
JFAIL = 1       # filter failed, print server should retry later
JABORT = 2      # filter failed, print server should suspend the queue
JREMOVE = 3     # job will be removed from print queue
JHOLD = 6       # job will be prevented from printing until lpc release

# Environment variables
# PRINTER = printer name
# PRINTCAP_ENTRY = complete printcap entry for this printer
# HF = job hold file contents
# SPOOL_DIR = spool directory

# HF contains df_name which is DataFile_Name created in SPOOL_DIR

class PyKotaFilter(PyKotaFilterOrBackend) :        
    """A class for the pykota filter for LPRng."""
    def acceptJob(self) :        
        """Returns the appropriate exit code to tell LPRng all is OK."""
        return JSUCC
            
    def removeJob(self) :            
        """Returns the appropriate exit code to tell LPRng job has to be removed."""   
        return JREMOVE
        
    def getJobOriginatingHostname(self, printername, username, jobid) :
        """Retrieves the job-originating-hostname if possible."""
        try :
            return [line[11:] for line in os.environ.get("HF", "").split() if line.startswith("remotehost=")][0]
        except IndexError :    
            try :
                return [line[1:] for line in os.environ.get("CONTROL", "").split() if line.startswith("H")][0]
            except IndexError :    
                return None
                
    def firstPass(self, policy, printer, user, userpquota) :            
        """First pass done here."""
        # first we have to check if previous job was correctly accounted for
        self.logdebug("First pass begins : POLICY_%s => %s => %s" % (policy, getattr(printer, "Name", None), getattr(user, "Name", None)))
        if printer.LastJob.Exists and not printer.LastJob.JobSize :
            # here we know that previous job wasn't accounted for correctly
            # we are sure (?) that it was hardware accounting which was used
            # and that the second pass didn't work or wasn't even launched
            # we know have to act just as if we were in second pass
            # for previous user on this printer, then we will continue
            # with normal processing of current user.
            self.secondPass(policy, printer, None, None)
        
        # export user info with initial values
        self.exportUserInfo(userpquota)
        
        # tries to extract job-originating-hostname 
        clienthost = self.getJobOriginatingHostname(printer.Name, user.Name, self.jobid)
        self.logdebug("Client Hostname : %s" % (clienthost or "Unknown"))    
        os.environ["PYKOTAJOBORIGINATINGHOSTNAME"] = str(clienthost or "")
        
        # indicates first pass
        os.environ["PYKOTAPHASE"] = "BEFORE"
        
        # precomputes the job's price
        self.softwareJobPrice = userpquota.computeJobPrice(self.softwareJobSize)
        os.environ["PYKOTAPRECOMPUTEDJOBPRICE"] = str(self.softwareJobPrice)
        self.logdebug("Precomputed job's size is %s pages, price is %s units" % (self.softwareJobSize, self.softwareJobPrice))
        
        # if no data to pass to real backend, probably a filter
        # higher in the chain failed because of a misconfiguration.
        # we deny the job in this case (nothing to print anyway)
        if not self.jobSizeBytes :
            self.printMoreInfo(user, printer, _("Job contains no data. Printing is denied."), "warn")
            action = "DENY"
        elif self.config.getDenyDuplicates(printer.Name) \
             and printer.LastJob.Exists \
             and (printer.LastJob.UserName == user.Name) \
             and (printer.LastJob.JobMD5Sum == self.checksum) :
            self.printMoreInfo(user, printer, _("Job is a duplicate. Printing is denied."), "warn")
            action = "DENY" 
        else :    
            # checks the user's quota
            action = self.warnUserPQuota(userpquota)
        
        # exports some new environment variables
        os.environ["PYKOTAACTION"] = action
        
        # launches the pre hook
        self.prehook(userpquota)
        
        self.printMoreInfo(user, printer, _("Job accounting begins."))
        self.accounter.beginJob(printer)
        
        jobsize = None
        if self.accounter.isSoftware :
            self.accounter.endJob(printer)
            jobsize = self.accounter.getJobSize(printer)
            self.printMoreInfo(user, printer, _("Job accounting ends."))
            
        if action == "DENY" :   
            jobsize = 0
            self.printMoreInfo(user, printer, _("Job size forced to 0 because printing is denied."))
            
        if (self.accounter.isSoftware) or (action == "DENY") :    
            # update the quota for the current user on this printer 
            self.printMoreInfo(user, printer, _("Job size : %i") % jobsize)
            self.printInfo(_("Updating user %s's quota on printer %s") % (user.Name, printer.Name))
            jobprice = userpquota.increasePagesUsage(jobsize)
            
            printer.addJobToHistory(self.jobid, user, self.accounter.getLastPageCounter(), \
                                    action, jobsize, jobprice, self.preserveinputfile, \
                                    self.title, self.copies, self.options, clienthost, \
                                    self.jobSizeBytes, self.checksum, None, None) # TODO : pages detail and billing code
            self.printMoreInfo(user, printer, _("Job added to history."))
            
            # exports some new environment variables
            os.environ["PYKOTAPHASE"] = "AFTER"
            os.environ["PYKOTAJOBSIZE"] = str(jobsize)
            os.environ["PYKOTAJOBPRICE"] = str(jobprice)
            
            # then re-export user information with new value
            self.exportUserInfo(userpquota)
            
            # Launches the post hook
            self.posthook(userpquota)
            
            # here accounting was completed, either software, or hardware but over quota
        else :
            printer.addJobToHistory(self.jobid, user, self.accounter.getLastPageCounter(), \
                                    action, filename=self.preserveinputfile, title=self.title, \
                                    copies=self.copies, options=self.options, clienthost=clienthost, \
                                    jobsizebytes=self.jobSizeBytes, jobmd5sum=self.checksum, jobpages=None, jobbilling=None) # TODO : pages detail and billing code
            self.logdebug("Job added to history during first pass : Job's size and price are still unknown.")
            
        self.logdebug("First pass ends : ACTION_%s => %s => %s" % (action, getattr(printer, "Name", None), getattr(user, "Name", None)))
        if action == "DENY" :
            return self.removeJob()
        else :    
            return self.acceptJob()
        
    def secondPass(self, policy, printer, user, userpquota) :    
        """Second pass done here."""
        # Last job for current printer has the same JobId than
        # the current job, so we know we are in the second pass
        self.logdebug("Second pass begins : POLICY_%s => %s => %s" % (policy, getattr(printer, "Name", None), getattr(user, "Name", None)))
        if self.accounter.isSoftware :
            # Software accounting method was used, and we are
            # in second pass, so all work is already done, 
            # now we just have to exit successfully
            self.printInfo(_("Software accounting already done in first pass. Ignoring."))
        elif printer.LastJob.JobAction == "DENY" :
            # Hardware accounting method was used, but job
            # was rejected during first pass, so nothing to do
            self.printInfo(_("Hardware accounting already done in first pass. Ignoring."))
        else :    
            # here if user and userpquota are both None
            # then it's a special second pass for a job
            # which should have had one but didn't, so
            # we need to get the last user, not the current one.
            if (user is None) and (userpquota is None) :
                user = printer.LastJob.User
                userpquota = self.storage.getUserPQuota(user, printer)
                
            # exports user info for last user    
            self.exportUserInfo(userpquota)
            
            # indicate phase change
            os.environ["PYKOTAPHASE"] = "AFTER"
            
            # fakes beginning of job with old page counter
            self.accounter.LastPageCounter = int(printer.LastJob.PrinterPageCounter or 0)
            self.accounter.fakeBeginJob()
            self.logdebug("Fakes beginning of job with LastPageCounter: %s" % self.accounter.getLastPageCounter())
            
            # stops accounting. 
            self.accounter.endJob(printer)
            self.logdebug("Job accounting ends.")
                
            # retrieve the job size    
            jobsize = self.accounter.getJobSize(printer)
            if self.softwareJobSize and (jobsize != self.softwareJobSize) :
                self.printInfo(_("Beware : computed job size (%s) != precomputed job size (%s)") % (jobsize, self.softwareJobSize), "error")
                (limit, replacement) = self.config.getTrustJobSize(printer.Name)
                if limit is None :
                    self.printInfo(_("The job size will be trusted anyway according to the 'trustjobsize' directive"), "warn")
                else :
                    if jobsize <= limit :
                        self.printInfo(_("The job size will be trusted because it is inferior to the 'trustjobsize' directive's limit %s") % limit, "warn")
                    else :
                        self.printInfo(_("The job size will be modified according to the 'trustjobsize' directive : %s") % replacement, "warn")
                        if replacement == "PRECOMPUTED" :
                            jobsize = self.softwareJobSize
                        else :    
                            jobsize = replacement
            
            self.printMoreInfo(user, printer, _("Job size : %i") % jobsize)
            self.printInfo(_("Updating user %s's quota on printer %s") % (user.Name, printer.Name))
            jobprice = userpquota.increasePagesUsage(jobsize)
            
            self.storage.writeLastJobSize(printer.LastJob, jobsize, jobprice)
            self.printMoreInfo(user, printer, _("Job size and price now set in history."))
            
            # exports some new environment variables
            os.environ["PYKOTAPHASE"] = "AFTER"
            os.environ["PYKOTAJOBSIZE"] = str(jobsize)
            os.environ["PYKOTAJOBPRICE"] = str(jobprice)
            
            # then re-export user information with new value
            self.exportUserInfo(userpquota)
            
            # Launches the post hook
            self.posthook(userpquota)
            
            # here hardware accounting was completed.
        self.logdebug("Second pass ends : POLICY_%s => %s => %s" % (policy, getattr(printer, "Name", None), getattr(user, "Name", None)))
        return self.acceptJob()
        
    def doWork(self, policy, printer, user, userpquota) :    
        """Most of the work is done here."""
        # Two different values possible for policy here :
        # ALLOW means : Either printer, user or user print quota doesn't exist,
        #               but the job should be allowed anyway.
        # OK means : Both printer, user and user print quota exist, job should
        #            be allowed if current user is allowed to print on this printer
        if policy == "ALLOW" :
            # nothing to do, just accept the job
            return self.acceptJob()
        else :    
            if printer.LastJob.Exists and (printer.LastJob.JobId == self.jobid) :
                # here we know we are in second pass.
                return self.secondPass(policy, printer, user, userpquota)
            else :    
                # Last job for current printer has a different JobId than
                # the current job, so we know we are in the first pass.
                return self.firstPass(policy, printer, user, userpquota)
            
if __name__ == "__main__" :    
    retcode = JSUCC
    try :
        # Initializes the backend
        kotabackend = PyKotaFilter()    
        kotabackend.deferredInit()
        retcode = kotabackend.mainWork()
        kotabackend.storage.close()
        kotabackend.closeJobDataStream()    
    except SystemExit :    
        retcode = JABORT
    except :
        try :
            kotabackend.crashed("lprngpykota filter failed")
        except :    
            crashed("lprngpykota filter failed")
        retcode = JABORT
        
    sys.exit(retcode)