Apparatus and method of accessing target devices across a bus utilizing initiator identifiers

• US 6,061,753 A
• Filed: 01/27/1998
• Issued: 05/09/2000
• Est. Priority Date: 01/27/1998
• Status: Expired due to Term

• Current Assignee: Data General Corp. (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Ericson, George M.
• Primary Examiner(s): AUVE, GLENN ALLEN
• Application Number:
  US09/014,064
• Time in Patent Office: 833 Days
• Field of Search: 710/240, 710/107, 710/36, 710/200, 710/110, 710/113, 711/147
• US Class Current: 710/107
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 2221/2141 Access rights, e.g. capability lists, access control lists, access tables, access matrices

Abstract

A method, apparatus, and computer program product for controlling access to a target device utilizes an initiator identifier to either permit or deny access to a selected portion of the target device. To that end, a message having the initiator identifier is directed from the initiator device to the target device to request access to the selected portion of the target device. Upon receipt by the target device, it is determined if the initiator identifier is in a permitted set of identifiers associated with the selected portion of the target device. If the initiator identifier is in the permitted set, then access to the portion of the target device is permitted and the initiator can access the target in accordance with conventionally known processes.

Claims

1. A method of controlling access by an initiator device to a target device on a bus, the initiator device being identified by an initiator identifier, the initiator device producing a message that is transmitted to the target device, the message including the initiator identifier, the method comprising the steps of:

A. determining, in response to receipt of the message, if the initiator identifier is in a permitted set of identifiers associated with a selected portion of the target device; and

B. denying access by the initiator device to the selected portion of the target device if it is determined that the initiator identifier is not in the permitted set of identifiers.

2. The method as defined by claim 1 wherein the message identifies the selected portion.

3. The method as defined by claim 1 further including the step of:

C. permitting access by the initiator device to the selected portion of the target device if it is determined that the initiator identifier is in the permitted set of identifiers.

4. The method as defined by claim 1 wherein step A comprises the steps of:

A1. identifying which portions of the target are accessible by the initiator device; and

A2. determining if the selected portion of the target is identified in step A1.

5. The method as defined by claim 1 wherein the bus is a SCSI bus and the message includes a logical unit number associated with the selected portion of the target device.

6. The method as defined by claim 1 wherein the initiator identifier specifies the physical address of the initiator on the bus.

7. The method as defined by claim 1 wherein the target includes a target identifier identifying the target, the initiator being connected to the bus, the step of determining including the steps of:

A3. determining the identity of the bus; and

A4. determining the target identifier.

8. The method as defined by claim 1 wherein the permitted set of identifiers has no more than one identifier.

9. The method as defined by claim 1 wherein the target device is a disk array.

10. The method as defined by claim 1 wherein the message is received by a target controller, and further wherein the target controller permits access by the initiator if the initiator identifier is in the permitted set of identifiers.

11. The method as defined by claim 1 wherein the target device receives the message and performs step A.

12. The method as defined by claim 1 wherein the permitted set of identifiers includes a logical unit number zero.

13. An apparatus for controlling access by an initiator device to a target device on a bus, the initiator device being identified by an initiator identifier, the initiator device producing a message that is transmitted to the target device, the message including the initiator identifier, the apparatus comprising:

means for determining, in response to receipt of the message, if the initiator identifier is in a permitted set of identifiers associated with a selected portion of the target device; and

means for denying access by the initiator device to the selected portion of the target device if it is determined that the initiator identifier is not in the permitted set of identifiers.

14. The apparatus as defined by claim 13 wherein the message identifies the selected portion.

15. The apparatus as defined by claim 13 further including:

means for permitting access by the initiator device to the selected portion of the target device if it is determined that the initiator identifier is in the permitted set of identifiers.

16. The apparatus as defined by claim 13 wherein the determining means comprises:

means for identifying which portions of the target are accessible by the initiator device; and

means for determining if the selected portion of the target is identified by the identifying means.

17. The apparatus as defined by claim 13 wherein the bus is a SCSI bus and the message includes a logical unit number associated with the selected portion of the target device.

18. The apparatus as defined by claim 13 wherein the target device is a disk array.

19. The apparatus as defined by claim 13 wherein the target includes a target identifier identifying the target, the initiator being connected to the bus, the means for determining including:

means for determining the identity of the bus; and

means for determining the target identifier.

20. The apparatus as defined by claim 13 wherein the permitted set of identifiers has no more than one identifier.

21. The apparatus as defined by claim 13 wherein the initiator identifier specifies the physical location of the initiator on the bus.

22. The apparatus as defined by claim 13 wherein the message is received by a target controller, and further wherein the target controller permits access by the initiator if the initiator identifier is in the permitted set of identifiers.

23. The apparatus as defined by claim 13 wherein the target device includes means for receiving the message and the determining means.

24. The apparatus as defined by claim 13 wherein the initiator has a specified configuration, the apparatus further including:

a driver having the specified configuration for processing messages received by the initiator; and

means for associating the initiator identifier with the driver.

25. A computer program product for use on a computer system for controlling access by an initiator device to a target device on a bus, the initiator device being identified by an initiator identifier, the initiator device producing a message that is transmitted to the target device, the message including the initiator identifier, the computer program product comprising a computer usable medium having computer readable program code thereon, the computer readable program code including:

program code for determining, in response to receipt of the message, if the initiator identifier is in a permitted set of identifiers associated with a selected portion of the target device; and

program code for permitting access by the initiator device to the selected portion of the target device if it is determined that the initiator identifier is in the permitted set of identifiers.

26. The computer program product as defined by claim 25 wherein the message identifies the selected portion.

27. The computer program product as defined by claim 25 further including:

program code for denying access by the initiator device to the selected portion of the target device if it is determined that the initiator identifier is not in the permitted set of identifiers.

28. The computer program product as defined by claim 25 wherein the program code for determining comprises:

program code for identifying which portions of the target are accessible by the initiator device; and

program code for determining if the selected portion of the target is identified by the execution of the program code for identifying.

29. The computer program product as defined by claim 25 wherein the bus is a SCSI bus and the message includes a logical unit number associated with the selected portion of the target device.

30. The computer program product as defined by claim 25 wherein the target device is a disk array.

31. The computer program product as defined by claim 25 wherein the target includes a target identifier identifying the target, the initiator being connected to the bus, the program code for determining including:

program code for determining the identity of the bus; and

program code for determining the target identifier.

32. The computer program product as defined by claim 25 wherein the permitted set of identifiers has no more than one identifier.

33. The computer program product as defined by claim 25 wherein the initiator identifier specifies the physical location of the initiator on the bus.

34. The computer program product as defined by claim 25 wherein the target device includes program code for receiving the message and the program code for determining.

35. A method of controlling access to a target device by an initiator device, the target device and initiator device each connected to a bus, the initiator device being identified by an initiator identifier, the initiator device producing a probe message that is transmitted to the target device, the probe message including the initiator identifier, the method comprising the steps of:

A. determining the initiator identifier from the probe message;

B. identifying, based upon the initiator identifier, at least zero portions of the target device that are accessible to the initiator device; and

C. producing a reply message that is transmitted to the initiator device, the reply message identifying the at least zero portions of the target device that are accessible to the initiator device.

36. The method as defined by claim 35 whereby in response to receipt of the reply message by the initiator device, the initiator device produces an access message, the method further comprising the step of:

D. permitting access, by the initiator device, to the at least zero portions of the target device in response to receipt of the access message, the access message identifying the at least zero portions of the target device.

37. The method as defined by claim 36 wherein the bus operates in accord with a specified bus protocol, step B comprising the step of:

B1. mapping the initiator identifier to the at least zero portions of the target device; and

B2. identifying the at least zero portions in accord with the bus protocol.

38. The method as defined by claim 35 wherein step B comprises the step of:

B1. locating an access set having data identifying any portion of the target to which the initiator may access.

39. An apparatus for controlling access to a target device by an initiator device, the target device and initiator device each connected to a bus, the initiator device being identified by an initiator identifier, the initiator device producing a probe message that is transmitted to the target device, the probe message including the initiator identifier, the apparatus comprising:

means for determining the initiator identifier from the probe message;

means for identifying, based upon the initiator identifier, at least zero portions of the target device that are accessible to the initiator device; and

means for producing a reply message that is transmitted to the initiator device, the reply message identifying the at least zero portions of the target device that are accessible to the initiator device.

40. The apparatus as defined by claim 39 wherein the bus operates in accord with a specified bus protocol, the means for identifying including:

means for mapping the initiator identifier to the at least zero portions of the target device; and

means for identifying the at least zero portions in accord with the bus protocol.

41. The apparatus as defined by claim 39 whereby in response to receipt of the reply message by the initiator device, the initiator device produces an access message, the apparatus further comprising:

means for permitting access, by the initiator device, to the at least zero portions of the target device in response to receipt of the access message, the access message identifying the at least zero portions of the target device.

42. The apparatus as defined by claim 39 wherein the identifying means comprises:

means for locating an access set having data identifying any portion of the target to which the initiator may access.

43. A computer program product for use on a computer system for controlling access to a target device by an initiator device, the target device and initiator device each connected to a bus, the initiator device being identified by an initiator identifier, the initiator device producing a probe message that is transmitted to the target device, the probe message including the initiator identifier, the computer program product comprising a computer usable medium having computer readable program code thereon, the computer readable program code including:

program code for determining the initiator identifier from the probe message;

program code for identifying, based upon the initiator identifier, at least zero portions of the target device that are accessible to the initiator device; and

program code for producing a reply message that is transmitted to the initiator device, the reply message identifying the at least zero portions of the target device that are accessible to the initiator device.

44. The computer program product as defined by claim 43 wherein the bus operates in accord with a specified bus protocol, the program code for identifying including:

program code for mapping the initiator identifier to the at least zero portions of the target device; and

program code for identifying the at least zero portions in accord with the bus protocol.

45. The computer program product as defined by claim 43 whereby in response to receipt of the reply message by the initiator device, the initiator device produces an access message, the computer program product further comprising:

program code for permitting access, by the initiator device, to the at least zero portions of the target device in response to receipt of the access message, the access message identifying the at least zero portions of the target device.

46. The computer program product as defined by claim 43 wherein the program code for identifying comprises:

program code for locating an access set having data identifying any portion of the target to which the initiator may access.

47. A target device for access by an initiator, the initiators being identified by an initiator identifier, the target device comprising:

a plurality of logical units;

means for ascertaining the initiator identifier; and

a target controller including means for permitting access by the initiator to a permitted set of the plurality of logical units target, the permitted set being less than all of the logical units in the target,

the target controller further including a memory for storing mapping data for mapping the initiator identifier to those logical units in the permitted set.

48. The target device as defined by claim 47 wherein the plurality of logical units are identified by the target by a first set of logical unit identifiers in a first format, the target device further including:

a receiving port for receiving a request message from initiators, each message including a second set of logical unit identifiers for identifying a set of logical units on the target to which access is requested by such initiator;

means for converting the identifiers in the second set of identifiers into the first format.

49. The target device as defined by claim 48 wherein the converting means converts at least one of the logical unit identifiers in the second set of identifiers into a logical unit number zero.

50. The target device as defined by claim 47 wherein the ascertaining means includes means for receiving a message from the initiator.

51. The target device as defined by claim 47 further including means for denying access if the initiator identifier is not mapped to the permitted set.

52. A method of controlling access to a target by two initiators on a bus, the first initiator having a first configuration and first initiator identifier, the second initiator having a second configuration and a second initiator identifier, the method comprising the steps of:

providing a first driver for interpreting the first configuration and facilitating access by the first initiator;

providing a second driver for interpreting the second configuration and facilitating access by the second initiator;

receiving an access message having one of the first initiator identifier and the second initiator identifier;

if the message has the first initiator identifier, directing the message to the first driver; and

if the message has the second initiator identifier, directing the message to the second driver.

53. The method as defined by claim 52 further including the step of:

permitting access by the first initiator to the target if the initiator identifier in the message is the first initiator identifier.

54. The method as defined by claim 52 further including the step of:

permitting access by the second initiator to the target if the initiator identifier in the message is the second initiator identifier.

55. An apparatus for controlling access to a target by two initiators on a bus, the first initiator having a first configuration and first initiator identifier, the second initiator having a second configuration and a second initiator identifier, the apparatus comprising:

a first driver for interpreting the first configuration and facilitating access by the first initiator;

a second driver for interpreting the second configuration and facilitating access by the second initiator;

a receiver for receiving an access message having one of the first initiator identifier and the second initiator identifier;

means for directing the access message to the first driver if the access message has the first initiator identifier; and

means for directing the access message to the second driver if the access message has the second initiator identifier.

56. The apparatus as defined by claim 55 further including:

means for permitting access by the first initiator to the target if the initiator identifier in the access message is the first initiator identifier.

57. The apparatus as defined by claim 55 further including:

means for permitting access by the second initiator to the target if the initiator identifier in the access message is the second initiator identifier.

58. A computer program product for use on a computer system for controlling access to a target by two initiators on a bus, the first initiator having a first configuration and first initiator identifier, the second initiator having a second configuration and a second initiator identifier, the computer program product comprising a computer usable medium having computer readable program code thereon, the computer readable program code including:

driver program code for interpreting the first configuration and facilitating access by the first initiator;

driver program code for interpreting the second configuration and facilitating access by the second initiator;

program code for receiving an access message having one of the first initiator identifier and the second initiator identifier;

program code for directing the message to the first driver if the message has the first initiator identifier; and

program code for directing the message to the second driver if the message has the second initiator identifier.

59. The computer program product as defined by claim 58 further including:

program code for permitting access by the first initiator to the target if the initiator identifier in the message is the first initiator identifier.

60. The computer program product as defined by claim 58 further including:

program code for permitting access by the second initiator to the target if the initiator identifier in the message is the second initiator identifier.

61. A method of controlling access by an initiator device to a target device on a bus, the initiator device being identified by an initiator identifier, the method comprising:

receiving a message from the initiator device, the message including the initiator identifier and a request to access a selected portion of the target device;

determining, in response to receipt of the message, if the initiator identifier is in a permitted set of identifiers associated with the selected portion of the target device; and

denying access by the initiator device to the selected portion of the target device if it is determined that the initiator identifier is not in the permitted set of identifiers.

62. The method as defined by claim 61 wherein the request to access the selected portion of the target device includes a first portion identifier identifying the selected portion of the target device.

63. The method as defined by claim 62 wherein the first portion identifier identifies a virtual portion of the target device, the method further comprising:

mapping the first portion identifier to an actual portion identifier, the actual portion identifier identifying the actual identity of the selected portion of the target device.

64. The method as defined by claim 61 wherein the bus comprises a plurality of ports, the initiator device being coupled with a first port on the bus, the target device being coupled with a second port on the bus.

65. The method as defined by claim 64 wherein the bus complies with the SCSI family of bus protocols.