src/decoderOutdated.py

@@ -6,11 +6,6 @@ import scapy.contrib.modbus as mb
 from triPacket import triPacket
 import getpass
 
-# ========================================================================================
-#   This decoder is outdated, as it uses a string parser on the packets given by scapy.
-#   Instead of this script, please use decoderMain.py.
-# ========================================================================================
-
 def decode(pkt):
     prt=0
     addr,value = "",""
@@ -120,5 +115,11 @@ if not db_user:
 db_password = getpass.getpass('user password : ')
 connec=[db_host,db_name,db_user,db_password]
 
+# si register 5 = 55 et coil 3 = 1 et coil 12 = 0 :
+# ecriture sur le registre 8 à 72 ou coil 9 à 1 impossibles
+# if ['r',5,55] and ['c',3,1] and ['c',12,0] and ecriture ['r',8,72]:
+    #bloquer ecriture
+# ecrire registre 5 72,4,4,55,4
+
 scapy.sniff(iface="lo", prn=decode)
 

src/ecritureBDD.py

@@ -2,64 +2,44 @@ import psycopg2 as psy
 import regles
 
 def verifRegle(co):
-    ''' verifRegle takes a connection to a database, from which it'll go through the data in the current transaction
-    to see if the data correlate to a possible rule violation.
-    '''
     cur=co.cursor()
     cur.execute('''SELECT type,addresse,valeur FROM Status ORDER BY type,addresse;''')
     res=cur.fetchall()
-    # res contains all the data from the current transaction. The entirety of the status table is loaded.
     dataState={}
     for row in res:
         dataState[(row[0],int(row[1]))]=int(row[2])
-        # the dictionnary dataState is a litteral representation of the database, with the key being a tuple of the address and the type of data,
-        # dataState's values are the values of the statuses.
     listRules=regles.getRegles()
-    # listRules contains all the rules created in regles.py, and getRegles is called to get a copy of the rules' list.
     for rule in listRules:
-        # we check each rule one by one, to see if they aren't violated
         ruleWarning=0
         condition=len(rule[0])
         for i in rule[0]:
             if (i[0],i[1]) in dataState:
                 if dataState[(i[0],i[1])]==i[2]:
                     ruleWarning+=1
-            # we first verify if the conditions aren't violated.
         if ruleWarning>=condition:
-            # if all the conditions of the rule are matched, we check to see if the request tries to update the forbidden value.
             if (rule[1][0],rule[1][1]) in dataState:
                 if dataState[(rule[1][0],rule[1][1])]==rule[1][2]:
                     return False
-                    # The boolean False is returned in the case where one rule is violated.
     return True
-    # If True is returned, it's because there's no rule that is violated, so the request isn't problematic for the system.
             
             
 
 
 def ecritureBDD(lStatus,connec):
-    ''' ecritureBDD is the function that is called to upsert (insert or update) the values of the status given in lStatus
-    connec contains the information needed to create a connection to the database
-    '''
     co = None
     try:
         co = psy.connect(host=connec[0],database=connec[1],user=connec[2],password=connec[3])
-        # the connection to the database is now created in co.
         cur = co.cursor()
-        # cur is a cursor on the connection to the database, it lets us perform actions on co's transaction.
         for i in lStatus:
             cur.execute("INSERT INTO Status VALUES (%s,%s,%s ) ON CONFLICT (addresse,type) DO UPDATE SET valeur=%s;",(i[1],i[0],i[2],i[2]))
-            # each statuses in lStatus is now upserted in the database on the current transaction, until commited, they aren't actually inside the database.
-        if verifRegle(co)!=True:
-            # verifRegle is executed with the current connection, so it has access to the transaction in order to verify if rules are violated.
+        if verifRegle(co):
+            co.commit()
+        else:
             print("A rule has been violated. The system is endangered. The database hasn't been updated.")
-            # A message is shown to the user to make him aware of the rule that is violated.
-            # a co.rollback() would be called if we managed to block the client request in order to prevent the server to be updated.
-        co.commit()
+            co.rollback()
         cur.close()
     except(Exception,psy.DatabaseError) as error:
         print(error)
-        # In case of an exception, like the failure of the creation of the connection, details are shown to tell the user about it.
     finally:
         if co is not None:
             co.close()

src/triPacket.py

@@ -1,22 +1,15 @@
 from ecritureBDD import ecritureBDD
 
 def decoupePacket(lPkt):
-    ''' decoupePacket is a recursive function that takes a list as an argument.
-    Its purpose is to create lists that shows the updated statuses from the modbus client's requests following the database format.
-    '''
     if type(lPkt)!=list:
-        # If the list of statuses isn't a list, nothing should be put inside the database.
         print('pas liste')
         return
     if len(lPkt)==0:
-        # If the list is empty, nothing should be put inside the database as well.
         print('liste vide')
         return
     if len(lPkt)==1:
-        # If the list has only one element, it is probably another list inside, that's why we call decoupePacket again.
         return decoupePacket(lPkt[0])
     if len(lPkt)==3 and type(lPkt[0])==str:
-        # If the list has a size of 3, and it's first element is a string type, we probably have the status we need to use.
         return [[lPkt[0],int(lPkt[1]),int(lPkt[2])]]
     else:
         l=[]
@@ -25,10 +18,5 @@ def decoupePacket(lPkt):
         return l
 
 def triPacket(lPkt,connec):
-    '''
-    triPacket takes the list of statuses obtained from the client's request and the information needed to connect to the database.
-    '''
     lNettoyee=decoupePacket(lPkt)
-    # decoupePacket is called in order to create a better structured list of statuses.
     ecritureBDD(lNettoyee,connec)
-    # ecritureBDD is now called to update the values inside the database.