METHODS AND SYSTEMS FOR PROVIDING A LEVEL OF ACCESS TO A COMPUTING DEVICE

• US 20090019226A1
• Filed: 07/11/2008
• Published: 01/15/2009
• Est. Priority Date: 07/11/2007
• Status: Abandoned Application

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Underwood, Daron R., Edwards, Matthew F.
• Application Number:
  US12/171,367
• Publication Number:
  US 20090019226A1
• Time in Patent Office: Days
• US Class Current: 711/128
• CPC Class Codes: G06F 9/4418 Suspend and resume; Hibernate and awake
• CPC Class Codes: G06F 9/5027 the resource being a machine, e.g. CPUs, Servers, Terminals

Abstract

A method for responding to read requests for a data block of a storage device, the storage device providing access to a hardened appliance and providing unrestricted access to a computing device, includes the step of executing a computing device in a requested one of a plurality of execution modes. A process intercepts a read request for a first data set stored in a data block of a storage device associated with the computing device. The read request is responded to with a second data set, the second data set stored in a cache and representing an unmodified version of the first data set presently stored in the data block of the storage device.

Claims

1. A method for responding to read requests for a data block of a storage device, the storage device providing access to a hardened appliance and providing unrestricted access to a computing device, the method comprising:

executing a computing device in a requested one of a plurality of execution modes;

intercepting, by a process, a read request for a first data set stored in a data block of a storage device associated with the computing device; and

responding to the read request with a second data set, the second data set stored in a cache and representing an unmodified version of the first data set presently stored in the data block of the storage device.

2. The method of claim 1, further comprising determining whether the requested data block comprises a previous modification to the first data set.

3. The method of claim 1, wherein the step of executing the computing device further comprises executing the computing device in the requested one of the plurality of execution modes, the requested one of the plurality of operating system execution modes granting read-only access to a storage device associated with the computing device, the plurality of execution modes including an execution mode providing read-write access to the hard drive.

4. The method of claim 1, wherein the step of intercepting further comprises intercepting, by a hook process, a read request for a first data set stored in the data block of the storage device.

5. The method of claim 1, wherein the step of intercepting further comprises intercepting, by a filter driver, the read request for the first data set stored in the data block of the storage device.

6. The method of claim 1, wherein the step of intercepting further comprises intercepting, by a write filter, the read request for the first data set stored in the data block of the storage device.

7. A system for responding to read requests for a data block of a storage device, the storage device providing both access to a hardened appliance and unrestricted access to a computing device, comprising:

means for executing a computing device in a requested one of a plurality of execution modes;

means for intercepting, by a process, a read request for a first data set stored in a data block of a storage device associated with the computing device; and

means for responding to the read request with a second data set, the second data set stored in a cache and representing an unmodified version of the first data set presently stored in the data block of the storage device.

8. The system of claim 7, further comprising means for determining whether the requested data block comprises a previous modification to the first data set.

9. The system of claim 7, wherein the means for executing the operating system further comprises means for executing the computing device in the requested one of the plurality of execution modes, the requested one of the plurality of execution modes granting read-only access to the storage device associated with the computing device, the plurality of execution modes including an execution mode providing read-write access to the storage device.

10. The system of claim 7, wherein the means for intercepting further comprises intercepting, by a hook process, a read request for a first data set stored in a data block of the storage device.

11. The system of claim 7, wherein the means for intercepting further comprises intercepting, by a filter driver, the read request for the first data set stored in the data block of the storage device.

12. The system of claim 7, wherein the means for intercepting further comprises intercepting, by a write filter, the read request for the first data set stored in the data block of the storage device.

13. A system for responding to read requests for a data block of a storage device, the storage device providing both access to a hardened appliance and unrestricted access to a computing device, comprising:

a computing device executing in a requested one of a plurality of execution modes;

a cache storing a first data set representing an unmodified version of a second data set stored in a data block of a storage device associated with the computing device;

a process intercepting a read request for the second data set and responding to the read request with the first data set.

14. The system of claim 13, wherein the process further comprises means for determining whether the requested data block comprises a modification to the first data set, the modification performed during a previously-executed session.

15. The system of claim 13, wherein the process further comprises means for accessing a lookup table to determine whether the requested data block comprises a modification to the first data set, the modification performed during a previously-executed session.

16. The system of claim 13, wherein the plurality of execution modes includes an execution mode providing read-write access to the hard drive.

17. The system of claim 13, wherein a hook process intercepts a read request for a first data set stored in the data block of the storage device.

18. The system of claim 13, wherein a filter driver intercepts the read request for the first data set stored in the data block of the storage device.

19. The system of claim 13, wherein a write filter intercepts the read request for the first data set stored in the data block of the storage device.

20. The system of claim 13, further comprising a second process intercepting a request to write data to a data block of the storage device, the request made during a session providing read-write access to the storage device.

21. The system of claim 20, wherein the cache stores an unmodified version of the data block of the storage device, prior to the execution of the write request.

22. The system of claim 21, wherein the second process allows the request to write data to the data block creating a modified data set in the data block.

23. A computer readable medium having instructions thereon that when executed provide a method for responding to read requests for a data block of a storage device providing both access to a hardened appliance and unrestricted access to a computing device, the computer readable medium comprising:

instructions to execute a computing device in a requested one of a plurality of execution modes;

instructions to intercept, by a process, a read request for a first data set stored in a data block of a storage device associated with the computing device; and

instructions to respond to the read request with a second data set, the second data set stored in a cache and representing an unmodified version of the first data set presently stored in the data block of the hard drive.

24. The computer readable medium of claim 23, further comprising instructions to determine whether the requested data block comprises a previous modification to the first data.

25. The computer readable medium of claim 23, wherein the instructions to execute further comprises instructions to execute the computing device in the requested one of the plurality of execution modes, the requested one of the plurality of execution modes granting read-only access to a storage device associated with the computing device, the plurality of execution modes including an execution mode providing read-write access to the storage device.

26. The computer readable medium of claim 23, wherein the instructions to intercept further comprises instructions to intercept, by a hook process, a read request for a first data set stored in the data block of the storage device.

27. The computer readable medium of claim 23, wherein the instructions to intercept further comprises instructions to intercept, by a filter driver, the read request for the first data set stored in the data block of the storage device.

28. The computer readable medium of claim 23, wherein the instructions to intercept further comprises instructions to intercept, by a write filter, the read request for the first data set stored in the data block of the storage device.

29. A method for providing a level of access to a computing device, the level selected according to a requested execution mode and a storage device associated with the computing device providing both access to a hardened appliance and unrestricted access to the computing device, the method comprising:

executing, during a first session, a computing device in a requested one of a plurality of execution modes available to a user of the computing device;

intercepting, by a first process, a request to write data to a data block of the storage device;

recording, in a cache, an unmodified data set in the data block, prior to the execution of the write request;

granting the request to write data to the data block to create a modified data set in the data block;

executing, during a second session, the computing device in a second one of the plurality of execution modes;

intercepting, by a second process, a request to read a data set in the data block of the storage device; and

responding to the read request using the unmodified data set.

30. The method of claim 29 further comprising the steps of:

executing, during a third session, the computing device in a third one of the plurality of execution modes;

intercepting, by a third process, a request to read data in the data block of the storage device; and

granting the request to read data in the data block of the storage device.

31. The method of claim 29 wherein the step of executing, during the second session, the computing device, further comprises the steps of

selecting a state file;

and

restoring the computing device to a pre-defined state responsive to data in the state file.

32. A system for providing a level of access to a computing device, the level selected according to a requested execution mode and a storage device associated with the computing device providing both access to a hardened appliance and unrestricted access to the computing device, comprising:

means for executing, during a first session, a computing device in a requested one of a plurality of execution modes available to a user of the computing device;

means for intercepting, by a first process, a request to write data to a data block of the storage device;

means for recording, in a cache, an unmodified data set in the data block, prior to the execution of the write request;

means for granting the request to write data to the data block to create a modified data set in the data block;

means for executing, during a second session, the computing device in a second one of the plurality of execution modes;

means for intercepting, by a second process, a request to read a data set in the data block of the storage device; and

means for responding to the read request using the unmodified data set.

33. The system of claim 32, wherein the means for intercepting a request to write data comprises intercepting, by a write filter, the write request for the data stored in the data block of the storage device.

34. The system of claim 32 further comprising

means for executing, during a third session, the computing device in a third one of the plurality of execution modes;

means for intercepting, by a hook process, a request to read data in the data block of the storage device; and

means for granting the request to read data in the data block of the storage device.

35. The system of claim 32 wherein the means for executing, during the second session, the operating system, further comprises

means for selecting a state file;

and

means for restoring the computing device to a pre-defined state responsive to data in the state file.

36. A system for providing a level of access to a computing device, the level selected according to a requested execution mode and a storage device associated with the computing device providing both access to a hardened appliance and unrestricted access to the computing device comprising:

a first operating system executing in a requested one of a plurality of execution modes available to a user of a computing device, the requested one of the plurality of execution modes providing write access to a storage device associated with the computing device;

a first process intercepting a request to write data to a data block of the storage device and granting the request to write data to the data block to create a modified data set in the data block;

a cache storing an unmodified data set in the data block, prior to the execution of the write request;

a second operating system executing in a second one of a plurality of execution modes, the second one of the plurality of execution modes providing read-only access to a storage device associated with a computing device;

a second process intercepting a read request for the data set stored in the data block of the storage device and responding to the read request with the unmodified data set stored in the cache.

37. The system of claim 36, wherein the first process further comprises a write filter intercepting the write request for the data stored in the data block of the storage device.

38. The system of claim 36 further comprising means for

selecting a state file;

and

restoring the computing device to a pre-defined state responsive to data in the state file.

39. The system of claim 36, wherein the second process further comprises means for determining whether the requested data block comprises a modification to the first data, the modification performed during a previously-executed session.

40. The system of claim 36, wherein the second process further comprises means for accessing a lookup table to determine whether the requested data block comprises a modification to the first data, the modification performed during a previously-executed session.

41. The system of claim 36, wherein a hook process intercepts a read request for the data set stored in the data block of the storage device.

42. The system of claim 36, wherein a filter driver intercepts the read request for the data set stored in the data block of the storage device.

43. The system of claim 36, wherein a write filter intercepts the read request for the data set stored in the data block of the storage device.

44. A computer readable medium having instructions thereon that when executed provide a method for providing a level of access to a computing device, the level selected according to a requested execution mode and a storage device associated with the hard drive providing both access to a hardened appliance and unrestricted access to a computing device, the computer readable medium comprising:

instructions to execute, during a first session, a computing device in a requested one of a plurality of operating system execution modes available to a user of a computing device, the requested one of the plurality of operating system execution modes providing write access to a hard drive associated with the computing device;

instructions to intercept, by a first process, a request to write data to a data block of the storage device;

instructions to record, in a cache, an unmodified data set in the data block, prior to the execution of the write request;

instructions to grant the request to write data to the data block to create a modified data set in the data block;

instructions to execute, during a second session, the computing device in a second one of the plurality of execution modes, the second one of the plurality of operating system execution modes providing read-only access to the hard drive;

instructions to intercept, by a second process, a request to read a data set in the data block of the hard drive; and

instructions to respond to the read request using the unmodified data set.

45. The computer readable medium of claim 44, wherein the instructions to intercept a request to write data comprises instructions to intercept, by a write filter, the write request for the data stored in the data block of the storage device.

46. The computer readable medium of claim 44 wherein the instructions to execute, during the second session, the computing device, further comprises

instructions to select a state file;

and

instructions to restore the computing device to a pre-defined state responsive to data in the state file.

47. The computer readable medium of claim 44 further comprising

instructions to execute, during a second session, the computing device in a second one of the plurality of operating system execution modes, the second one of the plurality of operating system execution modes providing write access to the hard drive;

instructions to intercept, by a hook process, a request to read data in a data block of the storage device; and

instructions to grant the request to read data in the data block of the storage device.