[nanny: 5/7] Add new LinuxSessionFiltering

[Roberto Majadas <telemaco src gnome org>]

commit cc0d6b5b3328934b96444aa594d611ed3e175b35
Author: Roberto Majadas <roberto majadas openshine com>
Date:   Sat Jun 4 02:24:40 2011 +0200

    Add new LinuxSessionFiltering

 daemon/src/LinuxSessionFiltering.py |  196 +++++++++++++++++++++++++++++++++++
 daemon/src/Makefile.am              |    2 +-
 daemon/src/QuarterBack.py           |    2 +-
 3 files changed, 198 insertions(+), 2 deletions(-)
---
diff --git a/daemon/src/LinuxSessionFiltering.py b/daemon/src/LinuxSessionFiltering.py
new file mode 100644
index 0000000..e08ea2c
--- /dev/null
+++ b/daemon/src/LinuxSessionFiltering.py
@@ -0,0 +1,196 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2009,2010,2011 Junta de Andalucia
+# 
+# Authors:
+#   Roberto Majadas <roberto.majadas at openshine.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, 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
+
+
+import gobject
+import os
+import dbus
+
+from twisted.internet import reactor, threads
+
+from subprocess import Popen, PIPE
+import time
+
+import gtop
+
+(
+SESSION_APPID,
+WEB_APPID,
+MAIL_APPID,
+IM_APPID) = range(4)
+
+class LinuxSessionBlocker(gobject.GObject) :
+    def __init__(self, quarterback, session_blocker="nanny-desktop-blocker"):
+        gobject.GObject.__init__(self)
+        self.quarterback = quarterback
+        self.sb = session_blocker
+        self.block_status = []
+
+    def is_user_blocked(self, user_id):
+        if user_id in self.block_status:
+            return True
+        else:
+            return False
+
+    def blocker_terminate_from_thread(self, user_id, ret):
+        print "[LinuxSessionFiltering] self.blocker_terminate_from_thread %s %s" % (user_id, ret)
+        if ret == 0:
+            gobject.timeout_add(5000, self.__remove_block_status, user_id)
+        else:
+            print "[LinuxSessionFiltering] User or other try to kill blocker :)"
+            gobject.timeout_add(5000, self.__launch_blocker_to_badboy, user_id)
+            
+
+    def set_block(self, user_id, block_status):
+        if block_status == True:
+            if user_id not in self.block_status :
+                self.__launch_blocker(user_id)
+        else:
+            try:
+                self.block_status.pop(self.block_status.index(user_id))
+            except:
+                pass
+
+    def __remove_block_status(self, user_id):
+        print "[LinuxSessionFiltering] Remove block status to user_id :  %s" % (user_id)
+        self.block_status.pop(self.block_status.index(user_id))
+        return False
+
+    def __launch_blocker_to_badboy(self, user_id):
+        x11_display = self.__get_user_session_display(user_id)
+        if x11_display != None :
+            user_name = self.quarterback.usersmanager.get_username_by_uid(user_id)
+            reactor.callInThread(self.__launch_blocker_thread, user_id, user_name, x11_display, self)
+        else:
+            self.block_status.pop(self.block_status.index(user_id))
+        return False
+
+    def __launch_blocker(self, user_id):
+        x11_display = self.__get_user_session_display(user_id)
+        
+        if x11_display != None :
+            self.block_status.append(user_id)
+            print "[LinuxSessionFiltering] blocking user %s" % user_id
+            user_name = self.quarterback.usersmanager.get_username_by_uid(user_id)
+            reactor.callInThread(self.__launch_blocker_thread, user_id, user_name, x11_display, self)
+        
+    def __launch_blocker_thread(self, user_id, user_name, x11_display, linuxsb):
+        try:
+            proclist = gtop.proclist(gtop.PROCLIST_KERN_PROC_UID, int(user_id))
+            env_lang_var = 'C'
+
+            if len(proclist) > 0 :
+                for proc in proclist :
+                    lang_var = Popen('cat /proc/%s/environ | tr "\\000" "\\n" | grep ^LANG= ' % proc , 
+                                     shell=True, stdout=PIPE).stdout.readline().strip("\n")
+                    if len(lang_var) > 0 :
+                        env_lang_var = lang_var.replace("LANG=","")
+                        break
+            
+            cmd = ['su', user_name, '-c', 
+                   'LANG=%s DISPLAY=%s nanny-desktop-blocker' % (env_lang_var, 
+                                                                 x11_display)]
+            print cmd
+            
+            p = Popen(cmd)
+            print "[LinuxSessionFiltering] launching blocker (pid : %s)" % p.pid
+
+            while p.poll() == None :
+                time.sleep(1)
+                b = threads.blockingCallFromThread(reactor, linuxsb.is_user_blocked, user_id)
+                if b == False:
+                    p.terminate()
+                    print "[LinuxSessionFiltering] Unblocking session %s" % user_id
+                    return
+
+            print "[LinuxSessionFiltering] blocker terminated by user interaction"
+            threads.blockingCallFromThread(reactor, linuxsb.blocker_terminate_from_thread, user_id, p.poll())
+        except:
+            print "[LinuxSessionFiltering] blocker terminated by exception"
+            threads.blockingCallFromThread(reactor, linuxsb.blocker_terminate_from_thread, user_id, 1)
+
+    def __get_user_session_display(self, user_id):
+        d = dbus.SystemBus()
+        manager = dbus.Interface(d.get_object("org.freedesktop.ConsoleKit", 
+                                              "/org/freedesktop/ConsoleKit/Manager"), 
+                                 "org.freedesktop.ConsoleKit.Manager")
+
+        sessions = manager.GetSessionsForUnixUser(int(user_id))
+        for session_name in sessions :
+            session = dbus.Interface(d.get_object("org.freedesktop.ConsoleKit", session_name),
+                                     "org.freedesktop.ConsoleKit.Session")
+            x11_display = session.GetX11Display()
+            if x11_display != "":
+                return x11_display
+        
+        return None
+
+class LinuxSessionFiltering(gobject.GObject) :
+    def __init__(self, quarterback) :
+        gobject.GObject.__init__(self)
+        self.quarterback = quarterback
+        
+        reactor.addSystemEventTrigger("before", "startup", self.start)
+        reactor.addSystemEventTrigger("before", "shutdown", self.stop)
+
+        self.updater_session_hd = None
+
+    def start(self):
+        print "Start Linux Session Filtering"
+        self.linuxsb = LinuxSessionBlocker(self.quarterback)
+        if self.linuxsb.sb != None :
+            print "[LinuxSessionFiltering] start watcher :)"
+            self.updater_session_hd = gobject.timeout_add(1000, self.__update_session_blocker_status)
+
+    def stop(self):
+        print "Stop Linux Session Filtering"
+        if self.updater_session_hd != None:
+            gobject.source_remove(self.updater_session_hd)
+        
+        self.linuxsb.block_status = []
+        reactor.iterate(delay=2)
+        print "Stopped Linux Session Filtering"
+
+
+    def __update_session_blocker_status(self):
+        blocks = self.quarterback.blocks
+        for user_id in blocks.keys() :
+            for app_id in blocks[user_id].keys() :
+                if app_id != SESSION_APPID :
+                    continue
+
+                if self.quarterback.get_available_time(user_id, app_id) == 0 :
+                    self.linuxsb.set_block(int(user_id), True)
+                    continue
+
+                try:
+                    block_status, next_block = self.quarterback.is_blocked(user_id, app_id)
+                except:
+                    print "[LinuxSessionFiltering] Fail getting self.quarterback.is_blocked"
+                    block_status = False
+
+                if block_status == True :
+                    self.linuxsb.set_block(int(user_id), True)
+                else:
+                    self.linuxsb.set_block(int(user_id), False)
+
+        return True
diff --git a/daemon/src/Makefile.am b/daemon/src/Makefile.am
index 982ac1d..1057137 100644
--- a/daemon/src/Makefile.am
+++ b/daemon/src/Makefile.am
@@ -11,7 +11,7 @@ corelib_PYTHON =	 __init__.py 			\
 			LinuxFiltering.py		\
 			LinuxWebContentFiltering.py 	\
 			LinuxUsersManager.py		\
-			LinuxSessionCKFiltering.py	\
+			LinuxSessionFiltering.py	\
 			Win32Filtering.py		\
 			Win32WebContentFiltering.py	\
 			Win32UsersManager.py		\
diff --git a/daemon/src/QuarterBack.py b/daemon/src/QuarterBack.py
index 9730951..42a0029 100644
--- a/daemon/src/QuarterBack.py
+++ b/daemon/src/QuarterBack.py
@@ -36,7 +36,7 @@ if os.name == "posix" :
     from LinuxFiltering import LinuxFiltering as FirewallFilter
     from LinuxWebContentFiltering import LinuxWebContentFiltering as WebContentFilter
     from LinuxUsersManager import LinuxUsersManager as UsersManager
-    from LinuxSessionCKFiltering import LinuxSessionCKFiltering as SessionFilter
+    from LinuxSessionFiltering import LinuxSessionFiltering as SessionFilter
     from FilterManager import FilterManager as FilterManager
     from Chrono import Chrono
 elif os.name == "nt" :