POLYLARVA Technology Agnostic Runtime Verification

1. POLYLARVA Technology Agnostic Runtime Verification

2. A System’s Behaviour

3. Testing

4. Model Checking

5. Runtime Verification

6. Inputs to Runtime Verification System • No more than 10 users can be logged onto the system at any one time • A user cannot execute more than 3 failed transactions in one session • A user which has been idle for more than 5 minutes should be logged out

7. Creating a Runtime Monitor

8. Creating a Runtime Monitor

9. Creating a Runtime Monitor

10. Creating a Runtime Monitor

11. Creating a Runtime Monitor

12. The LARVAArchitecture

13. LARVA– JAVA Specific Property to be verified : New accounts can be added for a User if the User settings allow It. Otherwise this should be disallowed. before ( User u1) : (call(* User.addAccount(..)) && target(u1) && !cflow(adviceexecution())) { Monitor monitor_instance = getMonitorInstance(u1); monitor_instance.call(thisJoinPoint.getSignature().toString(), 8/*addAccount*/); }

14. LARVA– JAVA Specific Property to be verified : New accounts can be added for a User if the User settings allow It. Otherwise this should be disallowed. if ((_occurredEvent(_event,8/*addAccount*/)) && (!u .canAddAccounts ())){ _state_id_account = 5;//moving to state cannotadd _goto_account(_info); }

15. LARVA– JAVA Specific Property to be verified : New accounts can be added for a User if the User settings allow It. Otherwise this should be disallowed. if ((_occurredEvent(_event,8/*addAccount*/)) && (!u .canAddAccounts ())){ _state_id_account = 5;//moving to state cannotadd _goto_account(_info); }

16. Goals for PolyLARVA • Improve LARVA framework to become a customisable monitoring architecture supporting potentially numerous platforms and technologies System (Any Language) Notifies monitor when specific Events take place Generated Monitor Evaluates monitoring logic

17. The PolyLARVASpecification Language • The PolyLarvaspecification language proposed is an ECA (Event-Condition-Action) rule-based language rule name : event \ condition  action ruleAddAccnt: addAccount(u2, a) \ isTooManyAccts -> logTooMany;

18. The PolyLARVASpecification Language ruleAddAccnt: addAccount(u2, a) \ isTooManyAccts -> logTooMany; states { intaccountCnt } conditions{ isTooManyAccts = {accountCnt > 5;} }

19. The PolyLARVASpecification Language ruleAddAccnt: addAccount(u2, a) \ isTooManyAccts -> logTooMany; states { intaccountCnt } conditions{ isTooManyAccts = {accountCnt > 5;} } actions { logTooMany = {System.out.println("Account limit of 5 exceeded.");}} }

20. Evaluating Conditions & Actions ruleAddUser: addUser( ) \ usercount > 5  logTooManyUsers Monitor System addUser() Keep Integer count of users in system - usercount Increment counter on new user addition. Compare this counter against a set limit on every new user addition Log warning message

21. Evaluating Conditions & Actions ruleAddUser: addAccount( User u ) \ u.canAddAccounts() logNewAccount u.canAddAccounts() Monitor System addAccount(User u) canAddAccounts is a property of a User Instance Monitor must refer to system to obtain evaluation of condition

22. Evaluating Conditions & Actions ruleAddUser: addAccount( User u ) \ u.canAddAccounts() logNewAccount u.canAddAccounts() Monitor System canAddAccounts is a property of a User Instance Monitor must refer to system to obtain evaluation of condition

23. System vs Monitor Conditions & Actions Monitor System conditions { monitorSide { isTooManyAccts = {accountCnt > 5;} } } conditions { systemSide { cannotAddAccts = {return !user.canAddAcounts();} } }

24. The PolyLARVAArchitecture Phase 1: Creation of JAVA code which covers the monitor logic for validating properties

25. The PolyLARVAArchitecture Phase 2: Creation of code which will be used to instrument the system code Creation of ‘Aspect’ code

26. The PolyLARVAArchitecture Phase 2: Creation of code which will be used to instrument the system code Creation of code that adds monitor logic on system side

27. The PolyLARVAArchitecture - Communication Communication between Monitor and Instrumented System via Sockets

28. The PolyLARVALanguage Specific Compiler

29. Generation of ‘Aspect’ Code • The Runtime Monitor must be aware of any events, relevant to monitoring, that occur on the system • Aspect Programming is ideal for use in Runtime Monitoring systems • Can support a large number of programming languages , though not all Aspect Code

30. Generation of JAVA ‘Aspect’ Code Event Specification Aspect Code addAccount(User u2, Account a) = {execution Account a.new(User u2)} Context_Aspect.aj before(Account a,User u2):target(a) && execution(Account.new(..)) && args (u2)&& !cflow(adviceexecution()){ LarvaCommClient.getClientConnection().sendMessage( LarvaCommClient.ASPECT_EVENT, 5, UniqueIDGenerator.getIdentifier(a)+","+ UniqueIDGenerator.getIdentifier(u2)+","); }

31. What if our system program is written in PERL? Event Specification Aspect Code addAccount(User u2, Account a) = {execution Account a.new(User u2)} Context_Aspect.pl PERL Aspect Code [uses Aspect.pm] Uses socket connection to communicate with monitor

32. Generation of Monitor ‘Helper’ Code(System Side) Helper Code conditions{ systemSide { cannotAddAccts = {!user.canAddAcounts();} } } %%conditions System side code copied verbatim to generated code. Helper code becomes part of System.

33. PolyLARVA – A Flexible Runtime Monitoring System

34. PolyLARVA – A Flexible Runtime Monitoring System

35. PolyLARVA– A Flexible Runtime Monitoring System

36. PolyLARVA– A Flexible Runtime Monitoring System

37. Future Work on PolyLARVARuntime Monitor • Implementation of other Language Specific Compilers • Implementation of translator for specification in DATEs format to new PolyLarvaspecification • Analysis of specification script for optimisation of rules • Ability to save and load Monitor state • Any more?

38. POLYLARVA Technology Agnostic Runtime Verification The END