fenrir/src/fenrir/screenDriver/vcsaDriver.py

#!/bin/python
# -*- coding: utf-8 -*-

# Fenrir TTY screen reader
# By Chrys, Storm Dragon, and contributers.

import difflib
import re
import subprocess
import glob, os
import fcntl
import termios
import time
import select
import dbus
from core import debug
from core.eventData import fenrirEventType
from utils import screen_utils

class driver():
    def __init__(self):
        self.vcsaDevicePath = '/dev/vcsa'
        self.ListSessions = None
    def initialize(self, environment):
        self.env = environment
        self.env['runtime']['eventManager'].addCustomEventThread(self.updateWatchdog)        
    def shutdown(self):
        pass
    def getCurrScreen(self):
        self.env['screen']['oldTTY'] = self.env['screen']['newTTY']
        try:    
            currScreenFile = open('/sys/devices/virtual/tty/tty0/active','r')
            self.env['screen']['newTTY'] = str(currScreenFile.read()[3:-1])
            currScreenFile.close()
        except Exception as e:
            self.env['runtime']['debug'].writeDebugOut(str(e),debug.debugLevel.ERROR)   
    def injectTextToScreen(self, text, screen = None):
        useScreen = "/dev/tty" + self.env['screen']['newTTY']
        if screen != None:
            useScreen = screen
        with open(useScreen, 'w') as fd:
            for c in text:
                fcntl.ioctl(fd, termios.TIOCSTI, c)
                
    def getCurrApplication(self):
        apps = []
        try:
            currScreen = self.env['screen']['newTTY']
            apps = subprocess.Popen('ps -t tty' + currScreen + ' -o comm,tty,stat', shell=True, stdout=subprocess.PIPE).stdout.read().decode()[:-1].split('\n')
        except Exception as e:
            self.env['runtime']['debug'].writeDebugOut(str(e),debug.debugLevel.ERROR)         
            return
        try:
            for i in apps:
                i = i.upper()
                i = i.split()
                i[0] = i[0]
                i[1] = i[1]
                if '+' in i[2]:
                    if i[0] != '':
                        if not "GREP" == i[0] and \
                          not "SH" == i[0] and \
                          not "PS" == i[0]:
                            if "TTY"+currScreen in i[1]:
                                if self.env['screen']['newApplication'] != i[0]:
                                    self.env['screen']['newApplication'] = i[0]                        
                                return
        except Exception as e:
            self.env['runtime']['debug'].writeDebugOut(str(e),debug.debugLevel.ERROR)    

    def getSessionInformation(self):
        try:
            bus = dbus.SystemBus()
            if not self.ListSessions:
                obj  = bus.get_object('org.freedesktop.login1', '/org/freedesktop/login1')
                inf = dbus.Interface(obj, 'org.freedesktop.login1.Manager')
                self.ListSessions = inf.get_dbus_method('ListSessions')
            sessions = self.ListSessions()
            self.env['screen']['autoIgnoreScreens'] = []
            for session in sessions:
                obj = bus.get_object('org.freedesktop.login1', session[4])
                inf = dbus.Interface(obj, 'org.freedesktop.DBus.Properties')
                sessionType = inf.Get('org.freedesktop.login1.Session', 'Type')
                screen = str(inf.Get('org.freedesktop.login1.Session', 'VTNr'))                                                            
                if screen == '':  
                    screen = str(inf.Get('org.freedesktop.login1.Session', 'TTY'))                                                         
                    screen = screen[screen.upper().find('TTY') + 3:]
                if screen == '':
                    self.env['runtime']['debug'].writeDebugOut('No TTY found for session:' + session[4],debug.debugLevel.ERROR)               
                    return
                if sessionType.upper() == 'X11':
                    self.env['screen']['autoIgnoreScreens'].append(screen)
                if screen == self.env['screen']['newTTY'] :
                    if self.env['general']['currUser'] != session[2]:
                        self.env['general']['prevUser'] = self.env['general']['currUser']
                        self.env['general']['currUser'] = session[2]                                                                
        except Exception as e:
            self.env['runtime']['debug'].writeDebugOut('getSessionInformation: Maybe no LoginD:' + str(e),debug.debugLevel.ERROR)               
            self.env['screen']['autoIgnoreScreens'] = []     
        self.env['runtime']['debug'].writeDebugOut('getSessionInformation:'  + str(self.env['screen']['autoIgnoreScreens']) + ' ' + str(self.env['general']) + ,debug.debugLevel.INFO)                           
 
    def updateWatchdog(self,active , eventQueue):
        try:
            vcsa = {}
            vcsaDevices = glob.glob('/dev/vcsa*')
            for vcsaDev in vcsaDevices:
                index = vcsaDev[9:]
                vcsa[str(index)] = open(vcsaDev,'rb')

            tty = open('/sys/devices/virtual/tty/tty0/active','r')
            currScreen = str(tty.read()[3:-1])
            oldScreen = currScreen
            watchdog = select.epoll()
            watchdog.register(vcsa[currScreen], select.EPOLLPRI)
            watchdog.register(tty, select.EPOLLPRI)
            lastScreenContent = b''
            while active.value == 1:
                changes = watchdog.poll(2)
                for change in changes:
                    fileno = change[0]
                    event = change[1]
                    if fileno == tty.fileno():
                        self.env['runtime']['debug'].writeDebugOut('ScreenChange',debug.debugLevel.INFO)                             
                        tty.seek(0)
                        currScreen = str(tty.read()[3:-1])        
                        if currScreen != oldScreen:
                            try:
                                watchdog.unregister(vcsa[ oldScreen ])              
                            except:
                                pass
                            try:
                                watchdog.register(vcsa[ currScreen ], select.EPOLLPRI)   
                            except:
                                pass
                            oldScreen = currScreen
                            eventQueue.put({"Type":fenrirEventType.ScreenChanged,"Data":''})  
                            try:
                                vcsa[currScreen].seek(0)                        
                                lastScreenContent = vcsa[currScreen].read() 
                            except:
                                lastScreenContent = b'' 
                    else:
                        self.env['runtime']['debug'].writeDebugOut('ScreenUpdate',debug.debugLevel.INFO)                                                 
                        vcsa[currScreen].seek(0)
                        screenContent = vcsa[currScreen].read()
                        if screenContent != lastScreenContent:
                            eventQueue.put({"Type":fenrirEventType.ScreenUpdate,"Data":''})
                            lastScreenContent = screenContent              
        except Exception as e:
            self.env['runtime']['debug'].writeDebugOut('VCSA:updateWatchdog:' + str(e),debug.debugLevel.ERROR)         
    
    def update(self, trigger='onUpdate'):
        if trigger == 'onInput': # no need for an update on input for VCSA
            return
        #print(self.env['screen']['newTTY'], self.env['screen']['oldTTY'])
        newContentBytes = b''       
        try:
            # read screen
            vcsa = open(self.vcsaDevicePath + self.env['screen']['newTTY'],'rb',0)
            newContentBytes = vcsa.read()
            vcsa.close()
            if len(newContentBytes) < 5:
                return
        except Exception as e:
            self.env['runtime']['debug'].writeDebugOut(str(e),debug.debugLevel.ERROR)   
            return
        screenEncoding = self.env['runtime']['settingsManager'].getSetting('screen', 'encoding')
        # set new "old" values
        self.env['screen']['oldContentBytes'] = self.env['screen']['newContentBytes']
        self.env['screen']['oldContentText'] = self.env['screen']['newContentText']
        self.env['screen']['oldContentAttrib'] = self.env['screen']['newContentAttrib']
        self.env['screen']['oldCursor'] = self.env['screen']['newCursor'].copy()
        if self.env['screen']['newCursorAttrib']:
            self.env['screen']['oldCursorAttrib'] = self.env['screen']['newCursorAttrib'].copy()        
        self.env['screen']['oldDelta'] = self.env['screen']['newDelta']
        self.env['screen']['oldAttribDelta'] = self.env['screen']['newAttribDelta']
        self.env['screen']['oldNegativeDelta'] = self.env['screen']['newNegativeDelta']
        self.env['screen']['newContentBytes'] = newContentBytes
        # get metadata like cursor or screensize
        self.env['screen']['lines'] = int( self.env['screen']['newContentBytes'][0])
        self.env['screen']['columns'] = int( self.env['screen']['newContentBytes'][1])
        self.env['screen']['newCursor']['x'] = int( self.env['screen']['newContentBytes'][2])
        self.env['screen']['newCursor']['y'] = int( self.env['screen']['newContentBytes'][3])
        # analyze content
        self.env['screen']['newContentText'] = self.env['screen']['newContentBytes'][4:][::2].decode(screenEncoding, "replace").encode('utf-8').decode('utf-8')
        self.env['screen']['newContentText'] = screen_utils.removeNonprintable(self.env['screen']['newContentText'])
        self.env['screen']['newContentAttrib'] = self.env['screen']['newContentBytes'][5:][::2]
        self.env['screen']['newContentText'] = screen_utils.insertNewlines(self.env['screen']['newContentText'], self.env['screen']['columns'])

        if self.env['screen']['newTTY'] != self.env['screen']['oldTTY']:
            self.env['screen']['oldContentBytes'] = b''
            self.env['screen']['oldContentAttrib'] = b''
            self.env['screen']['oldContentText'] = ''
            self.env['screen']['oldCursor']['x'] = 0
            self.env['screen']['oldCursor']['y'] = 0
            self.env['screen']['oldDelta'] = ''
            self.env['screen']['oldAttribDelta'] = ''            
            self.env['screen']['oldCursorAttrib'] = None
            self.env['screen']['newCursorAttrib'] = None            
            self.env['screen']['oldNegativeDelta'] = ''
        # initialize current deltas
        self.env['screen']['newNegativeDelta'] = ''
        self.env['screen']['newDelta'] = ''
        self.env['screen']['newAttribDelta'] = ''                           

        # changes on the screen
        oldScreenText = re.sub(' +',' ',self.env['runtime']['screenManager'].getWindowAreaInText(self.env['screen']['oldContentText']))
        newScreenText = re.sub(' +',' ',self.env['runtime']['screenManager'].getWindowAreaInText(self.env['screen']['newContentText']))        
        typing = False
        if (self.env['screen']['oldContentText'] != self.env['screen']['newContentText']) and \
          (self.env['screen']['newContentText'] != '' ):
            if oldScreenText == '' and\
              newScreenText != '':
                self.env['screen']['newDelta'] = newScreenText
            else:
                cursorLineStart = self.env['screen']['newCursor']['y'] * self.env['screen']['columns'] + self.env['screen']['newCursor']['y']
                cursorLineEnd = cursorLineStart  + self.env['screen']['columns']            
                if self.env['screen']['oldCursor']['x'] != self.env['screen']['newCursor']['x'] and \
                  self.env['screen']['oldCursor']['y'] == self.env['screen']['newCursor']['y'] and \
                  self.env['screen']['newContentText'][:cursorLineStart] == self.env['screen']['oldContentText'][:cursorLineStart]:

                    oldScreenText = self.env['screen']['oldContentText'][cursorLineStart:cursorLineEnd] 
                    oldScreenText = re.sub(' +',' ',oldScreenText)
                    newScreenText = self.env['screen']['newContentText'][cursorLineStart:cursorLineEnd]
                    newScreenText = re.sub(' +',' ',newScreenText)
                    diff = difflib.ndiff(oldScreenText, newScreenText) 
                    typing = True                      
                else:
                    diff = difflib.ndiff( oldScreenText.split('\n'),\
                      newScreenText.split('\n'))

                diffList = list(diff)
                
                if self.env['runtime']['settingsManager'].getSetting('general', 'newLinePause') and not typing:
                    self.env['screen']['newDelta'] = '\n'.join(x[2:] for x in diffList if x[0] == '+')
                else:
                    self.env['screen']['newDelta'] = ''.join(x[2:] for x in diffList if x[0] == '+')             
                self.env['screen']['newNegativeDelta'] = ''.join(x[2:] for x in diffList if x[0] == '-')
        
        # track highlighted
        if self.env['screen']['oldContentAttrib'] != self.env['screen']['newContentAttrib']:
            if self.env['runtime']['settingsManager'].getSettingAsBool('focus', 'highlight'):
                self.env['screen']['newAttribDelta'], self.env['screen']['newCursorAttrib'] = screen_utils.trackHighlights(self.env['screen']['oldContentAttrib'], self.env['screen']['newContentAttrib'], self.env['screen']['newContentText'], self.env['screen']['columns'])