root / pykota / trunk / bin / pknotify @ 2992

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

# A notifier for PyKota
#
# PyKota - Print Quotas for CUPS and LPRng
#
# (c) 2003, 2004, 2005, 2006 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 socket
import signal
import xmlrpclib

try :
    import PAM
except ImportError :    
    hasPAM = 0
else :    
    hasPAM = 1

from pykota.tool import Tool, PyKotaCommandLineError, crashed, N_

__doc__ = N_("""pknotify v%(__version__)s (c) %(__years__)s %(__author__)s

Notifies or ask questions to end users who launched the PyKotIcon application.

command line usage :

  pknotify  [options]  [arguments]

options :

  -v | --version             Prints pknotify's version number then exits.
  -h | --help                Prints this message then exits.
  
  -d | --destination h[:p]   Sets the destination hostname and optional
                             port onto which contact the remote PyKotIcon
                             application. This option is mandatory.
                             When not specified, the port defaults to 7654.
                             
  -a | --ask                 Tells pknotify to ask something to the end
                             user. Then pknotify will output the result.
                       
  -C | --checkauth           When --ask is used and both an 'username' and a
                             'password' are asked to the end user, then
                             pknotify will try to authenticate the user
                             through PAM. If authentified, this program
                             will print "AUTH=YES", else "AUTH=NO".
                             If a field is missing, "AUTH=IMPOSSIBLE" will
                             be printed. If the user is authenticated, then
                             "USERNAME=xxxx" will be printed as well.
                             
  -c | --confirm             Tells pknotify to ask for either a confirmation                       
                             or abortion.
                             
  -D | --denyafter N         With --checkauth above, makes pknotify loop                           
                             up to N times if the password is incorrect.
                             After having reached the limit, "DENY" will
                             be printed, which effectively rejects the job.
                             The default value of N is 1, meaning the job
                             is denied after the first unsuccessful try.
                             
  -n | --notify              Tells pknotify to send an informational message
                             to the end user.
                             
  -q | --quit                Tells pknotify to send a message asking the
                             PyKotIcon application to exit. This option can
                             be combined with the other ones to make PyKotIcon
                             exit after having sent the answer from the dialog.
                             
  -t | --timeout T           Tells pknotify to ignore the end user's answer if
                             it comes past T seconds after the dialog box being
                             opened. The default value is 0 seconds, which 
                             tells pknotify to wait indefinitely.
                             Use this option to avoid having an user who
                             leaved his computer stall a whole print queue.
                             
  You MUST specify either --ask, --confirm, --notify or --quit.

  arguments :             
  
    -a | --ask : Several arguments are accepted, of the form
                 "label:varname:defaultvalue". The result will
                 be printed to stdout in the following format :
                 VAR1NAME=VAR1VALUE
                 VAR2NAME=VAR2VALUE
                 ...
                 If the dialog was cancelled, nothing will be
                 printed. If one of the varname is 'password'
                 then this field is asked as a password (you won't
                 see what you type in), and is NOT printed. Although
                 it is not printed, it will be used to check if
                 authentication is valid if you specify --checkauth.
                 
    -c | --confirm : A single argument is expected, representing the
                     message to display. If the dialog is confirmed
                     then pknotify will print OK, else CANCEL.
                     
    -n | --notify : A single argument is expected, representing the                 
                    message to display. In this case pknotify will
                    always print OK.
                    
examples :                    

  pknotify -d client:7654 --confirm "This job costs :\n10 credits !"
  
  Would display the cost of a print job and asks for confirmation.
  
  pknotify --destination $PYKOTAJOBORIGINATINGHOSTNAME:7654 \\
           --checkauth --ask "Your name:username:" "Your password:password:"
           
  Asks an username and password, and checks if they are valid.         
  NB : The PYKOTAJOBORIGINATINGHOSTNAME environment variable is
  only set if you launch pknotify from cupspykota through a directive
  in ~pykota/pykota.conf
  
  The TCP port you'll use must be reachable on the client from the
  print server.
""")
        
class TimeoutError(Exception) :        
    """An exception for timeouts."""
    def __init__(self, message = ""):
        self.message = message
        Exception.__init__(self, message)
    def __repr__(self):
        return self.message
    __str__ = __repr__
    
class PyKotaNotify(Tool) :        
    """A class for pknotify."""
    def sanitizeMessage(self, msg) :
        """Replaces \\n and returns a messagee in xmlrpclib Binary format."""
        return xmlrpclib.Binary(self.userCharsetToUTF8(msg.replace("\\n", "\n")))
        
    def convPAM(self, auth, queries=[], userdata=None) :
        """Prepares PAM datas."""
        response = []
        for (query, qtype) in queries :
            if qtype == PAM.PAM_PROMPT_ECHO_OFF :
                response.append((self.password, 0))
            elif qtype in (PAM.PAM_PROMPT_ECHO_ON, PAM.PAM_ERROR_MSG, PAM.PAM_TEXT_INFO) :
                self.printInfo("Unexpected PAM query : %s (%s)" % (query, qtype), "warn")
                response.append(('', 0))
            else:
                return None
        return response

    def checkAuth(self, username, password) :    
        """Checks if we could authenticate an username with a password."""
        if not hasPAM :    
            raise PyKotaCommandLineError, _("You MUST install PyPAM for this functionnality to work !")
        else :    
            retcode = False
            self.password = password
            self.regainPriv()
            auth = PAM.pam()
            auth.start("passwd")
            auth.set_item(PAM.PAM_USER, username)
            auth.set_item(PAM.PAM_CONV, self.convPAM)
            try :
                auth.authenticate()
                auth.acct_mgmt()
            except PAM.error, resp :
                self.printInfo(_("Authentication error for user %s : %s") % (username, resp), "warn")
            except :
                self.printInfo(_("Internal error : can't authenticate user %s") % username, "error")
            else :
                self.logdebug(_("Password correct for user %s") % username)
                retcode = True
            self.dropPriv()    
            return retcode
            
    def alarmHandler(self, signum, frame) :        
        """Alarm handler."""
        raise TimeoutError, _("The end user at %s:%i didn't answer within %i seconds. The print job will be cancelled.") % (self.destination, self.port, self.timeout)
        
    def main(self, arguments, options) :
        """Notifies or asks questions to end users through PyKotIcon."""
        try :
            (self.destination, self.port) = options["destination"].split(":")
            self.port = int(self.port)
        except ValueError :
            self.destination = options["destination"]
            self.port = 7654
            
        try :
            denyafter = int(options["denyafter"])
            if denyafter < 1 :
                raise ValueError
        except (ValueError, TypeError) :        
            denyafter = 1
            
        try :    
            self.timeout = int(options["timeout"])
            if self.timeout < 0 :
                raise ValueError
        except (ValueError, TypeError) :
            self.timeout = 0
            
        if self.timeout :
            signal.signal(signal.SIGALRM, self.alarmHandler)
            signal.alarm(self.timeout)
            
        try :    
            server = xmlrpclib.ServerProxy("http://%s:%s" % (self.destination, self.port))
            if options["ask"] :
                try :
                    denyafter = int(options["denyafter"])
                    if denyafter < 1 :
                        raise ValueError
                except (ValueError, TypeError) :    
                    denyafter = 1
                labels = []
                varnames = []
                varvalues = {}
                for arg in arguments :
                    try :
                        (label, varname, varvalue) = arg.split(":", 2)
                    except ValueError :    
                        raise PyKotaCommandLineError, "argument '%s' is invalid !" % arg
                    labels.append(self.sanitizeMessage(label))
                    varname = varname.lower()
                    varnames.append(varname)
                    varvalues[varname] = self.sanitizeMessage(varvalue)
                    
                passnumber = 1    
                authok = None
                while (authok != "AUTH=YES") and (passnumber <= denyafter) :
                    result = server.askDatas(labels, varnames, varvalues)    
                    if not options["checkauth"] :
                        break
                    if result["isValid"] :
                        if ("username" in varnames) and ("password" in varnames) :
                            if self.checkAuth(self.UTF8ToUserCharset(result["username"].data[:]), 
                                              self.UTF8ToUserCharset(result["password"].data[:])) :
                                authok = "AUTH=YES"
                            else :    
                                authok = "AUTH=NO"
                        else :        
                            authok = "AUTH=IMPOSSIBLE"        
                    passnumber += 1        
                                
                if options["checkauth"] and options["denyafter"] \
                   and (passnumber > denyafter) \
                   and (authok != "AUTH=YES") :
                    print "DENY"
                if result["isValid"] :
                    for varname in varnames :
                        if (varname != "password") \
                           and ((varname != "username") or (authok in (None, "AUTH=YES"))) :
                            print "%s=%s" % (varname.upper(), self.UTF8ToUserCharset(result[varname].data[:]))
                    if authok is not None :        
                        print authok        
            elif options["confirm"] :
                print server.showDialog(self.sanitizeMessage(arguments[0]), True)
            elif options["notify"] :
                print server.showDialog(self.sanitizeMessage(arguments[0]), False)
                
            if options["quit"] :    
                server.quitApplication()
        except (socket.error, socket.gaierror), msg :
            raise PyKotaCommandLineError, "%s : %s" % (_("Connection error"), str(msg))
        except TimeoutError, msg :    
            self.printInfo(msg, "warn")
            print "CANCEL"      # Timeout occured : job is cancelled.
            
        if self.timeout :    
            signal.alarm(0)    
        
if __name__ == "__main__" :
    retcode = 0
    try :
        defaults = { \
                     "timeout" : 0,
                   }
        short_options = "vhd:acnqCD:t:"
        long_options = ["help", "version", "destination=", "denyafter=", \
                        "timeout=", "ask", "checkauth", "confirm", "notify", \
                        "quit" ]
        
        # Initializes the command line tool
        notifier = PyKotaNotify(doc=__doc__)
        notifier.deferredInit()
        
        # parse and checks the command line
        (options, args) = notifier.parseCommandline(sys.argv[1:], short_options, long_options)
        
        # sets long options
        options["help"] = options["h"] or options["help"]
        options["version"] = options["v"] or options["version"]
        options["destination"] = options["d"] or options["destination"]
        options["ask"] = options["a"] or options["ask"]
        options["confirm"] = options["c"] or options["confirm"]
        options["notify"] = options["n"] or options["notify"]
        options["quit"] = options["q"] or options["quit"]
        options["checkauth"] = options["C"] or options["checkauth"]
        options["denyafter"] = options["D"] or options["denyafter"]
        options["timeout"] = options["t"] or options["timeout"] or defaults["timeout"]
        
        if options["help"] :
            notifier.display_usage_and_quit()
        elif options["version"] :
            notifier.display_version_and_quit()
        elif (options["ask"] and (options["confirm"] or options["notify"])) \
             or (options["confirm"] and (options["ask"] or options["notify"])) \
             or ((options["checkauth"] or options["denyafter"]) and not options["ask"]) \
             or (options["notify"] and (options["ask"] or options["confirm"])) :
            raise PyKotaCommandLineError, _("incompatible options, see help.")
        elif (not options["destination"]) \
             or not (options["quit"] or options["ask"] or options["confirm"] or options["notify"]) :
            raise PyKotaCommandLineError, _("some options are mandatory, see help.")
        elif (not args) and (not options["quit"]) :
            raise PyKotaCommandLineError, _("some options require arguments, see help.")
        else :
            retcode = notifier.main(args, options)
    except KeyboardInterrupt :        
        sys.stderr.write("\nInterrupted with Ctrl+C !\n")
        retcode = -3
    except PyKotaCommandLineError, msg :    
        sys.stderr.write("%s : %s\n" % (sys.argv[0], msg))
        retcode = -2
    except SystemExit :        
        pass
    except :
        try :
            notifier.crashed("%s failed" % sys.argv[0])
        except :    
            crashed("%s failed" % sys.argv[0])
        retcode = -1
        
    sys.exit(retcode)