root / pykota / trunk / bin / pknotify @ 3260

#! /usr/bin/env python
# -*- coding: UTF-8 -*-
#
# PyKota : Print Quotas for CUPS
#
# (c) 2003, 2004, 2005, 2006, 2007 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 3 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, see <http://www.gnu.org/licenses/>.
#
# $Id$
#
#

import sys
import socket
import errno
import signal
import xmlrpclib

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

from pykota.tool import Tool, PyKotaToolError, 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 | --noremote action     If it's impossible to connect to the remote
                             PyKotIcon machine, do this action instead.
                             Allowed actions are 'CONTINUE' and 'CANCEL', 
                             which will respectively allow the processing
                             of the print job to continue, or the job to
                             be cancelled. The default value is CANCEL.
                             
  -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 --noremote CONTINUE --confirm "This job costs 10 credits"
  
  Would display the cost of the print job and asks for confirmation.
  If the end user doesn't have PyKotIcon running and accepting connections
  from the print server, PyKota will consider that the end user accepted
  to print this job.
  
  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 PyKotaToolError, _("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 :
            print options["noremote"]
            try :
                errnum = msg.args[0]
            except (AttributeError, IndexError) :
                pass
            else :    
                if errnum == errno.ECONNREFUSED :
                    raise PyKotaToolError, "%s : %s" % (str(msg), (_("Are you sure that PyKotIcon is running and accepting incoming connections on %s:%s ?") % (self.destination, self.port)))
            self.printInfo("%s : %s" % (_("Connection error"), str(msg)), "warn")
        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,
                     "noremote" : "CANCEL",
                   }
        short_options = "vhd:acnqCD:t:N:"
        long_options = ["help", "version", "destination=", "denyafter=", \
                        "timeout=", "ask", "checkauth", "confirm", "notify", \
                        "quit", "noremote=" ]
        
        # 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"]
        options["noremote"] = (options["N"] or options["noremote"] or defaults["noremote"]).upper()
        
        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 options["noremote"] not in ("CANCEL", "CONTINUE") :
            raise PyKotaCommandLineError, _("incorrect value for the --noremote command line switch, 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))
        print "CANCEL"  # Forces the cancellation of the print job if a command line switch is incorrect
        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)