Multiple offload of network state objects with support for failover events

• US 7,526,577 B2
• Filed: 09/19/2003
• Issued: 04/28/2009
• Est. Priority Date: 09/19/2003
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Pinkerton, James T., Kaniyar, Sanjay N.
• Primary Examiner(s): Dalencourt; Yves
• Application Number:
  US10/666,086
• Publication Number:
  US 20050066060A1
• Time in Patent Office: 2,048 Days
• Field of Search: 709/238, 709/230, 709/247, 709/249, 709/227, 709/228, 709/243, 792/02, 370/229, 370/230, 370/231, 370/232, 710/15, 710/316
• US Class Current: 709/249
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 69/10 Streamlined, light-weight or high-speed protocols, e.g. express transfer protocol [XTP] or byte stream
• CPC Class Codes: H04L 69/32 Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level

Abstract

The present invention provides mechanisms for transferring processor control of multiple network connections between two component devices of a computerized system, such as between a host CPU and a NIC. In one aspect of the invention, two or more network communications may each have a different state object in the upper layers of a network protocol stack, and have a common state object in the lower layers (e.g., the Framing Layer) of the network protocol stack. In part due to the commonalities in the lower software layer states, the invention provides for offloading processor control of multiple network communications at once, including long and short-lived connections. In addition, the invention can negotiate with an alternative peripheral device to offload the network communication to the alternative peripheral device in the event of a failover event, and provides a solution to incoming data packets destined for one or more VLANs.

Claims

1. In a computerized system comprising a processor, a switching layer, and a sequence of one or more intermediate software layers of a network protocol stack, each of the intermediate software layers having a state object, a method for transferring control between one or more destination component devices and one or more source component devices, the control needed to process a plurality of network connections while still maintaining integrity of established network communication, the method comprising the following:

an act of generating an offload data structure, the offload data structure comprising a hierarchy of a plurality of state objects forming an inverted tree structure, the hierarchy corresponding to a plurality of network connections sharing a common path state object, the plurality of state objects corresponding to a network protocol state for one or more intermediate software layers;

an act of concurrently transferring from a source component device to a destination component device two or more state objects corresponding to the plurality of network connections in the same intermediate software layer of the offload data structure wherein one of the destination component and source component is a peripheral device;

an act of the destination component processing the two or more state objects at the same protocol layer after the transfer an act of detecting a failover event at one or more peripheral device, which includes;

an act of detecting that one or more links being processed at one or more corresponding peripheral devices have failed, the one or more failed peripheral devices having been given processor control of one or more offload data structures and one or more state objects; and

an act of detecting a different one or more peripheral devices for handling processing control of the one or more links by receiving the one or more offload data structures and control of the one or more state objects.

2. The method of claim 1, wherein at least one of the two or more state objects includes a cached state variable, wherein the source component device maintains ownership of the cached state variable and the source component ensures that any changes to the cached state variable in the source component device is updated on the destination component device.

3. The method of claim 1, wherein the offload data structure further comprises a block list having at least a next block pointer that points to the same intermediate software layer of a different network connection path through the network protocol stack, and a dependent block pointer that points to a different hierarchal layer of the same network connection path through the network protocol stack.

4. The method of claim 1, wherein the act of transferring the offload data structure and the portion of the state object for each software layer is performed during the slow-start phase of a TCP connection.

5. The method of claim 1, further comprising an act of inserting an intermediate driver data structure in the offload data structure, the intermediate driver having programming to decipher and encapsulate deciphering and encapsulating incoming and outgoing data packets, as appropriate, wherein the outgoing data packets are packaged with one or more virtual local area network identifiers, and incoming packets are stripped of one or more virtual local area network identifiers.

6. The method of claim 5, wherein the intermediate driver includes programming for securing network traffic over one or more network links using an IPSEC protocol by performing one or more of adding and removing an authentication header to a data packet, and encrypting and decrypting the data packet, as appropriate.

7. The method of claim 1, further comprising:

an act of the peripheral device generating one or more handles for one or more intermediate software layers, wherein the peripheral device transfers the one or more handles to one or more corresponding host protocol stack layers; and

an act of, when at least one of the intermediate software layers changes cached state, the at least one of the intermediate software layers updating the cached state of the peripheral device.

8. The method of claim 1, wherein the one or more state objects comprise at least one of a delegated state or a cached state, the method further comprising transferring to the source component the one or more offload data structures and processing control of only the one or more state objects corresponding to a delegated state from the one or more failed peripheral devices wherein the cached states are not transferred to the source component, thereby uploading processing control of the one or more links from the one or more failed peripheral devices to the source component.

9. The method of claim 8, further comprising an act of detecting a processing resource of the different one or more peripheral devices;

and adjusting the one or more state objects that have been uploaded from the one or more failed peripheral devices to match the detected resource of the different one or more peripheral devices, so that the one or more links can be processed at the different one or more peripheral devices rather than at the failed one or more peripheral devices.

10. The method of claim 9, wherein the one or more links are aggregated 802.3ad links.

11. The method of claim 1, further comprising:

an act of detecting a processing resource of the different one or more peripheral devices;

when one of the one or more offloaded state objects can be processed by the different one or more peripheral devices based on the detected processing resource, transferring processing control of the one of the one or more offloaded state objects to the different one or more peripheral devices; and

when the one or more offloaded state objects cannot be processed by the different one or more peripheral devices based on the detected processing resource, transferring processing control of the one of the one or more offloaded state objects to the host protocol stack.

12. The method of claim 11, wherein the one or more links are aggregated 802.3ad links.

13. The method of claim 1, wherein the plurality of state objects are of

a plurality of short-lived network connections, wherein the act of transferring comprises transferring two or more short-lived network connections in the same intermediate software layer of the offload data structure and wherein the act of processing comprises processing the two or more short-lived connections after the transfer.

14. The method of claim 13, wherein one of the destination component and source component is a peripheral device.

15. The method of claim 14, wherein a state object includes a cached state variable, and one or more of a constant state variable, and a delegated state variable.

16. The method of claim 14, wherein the offload data structure includes a block list having at least a next block pointer that points to the same intermediate software layer of a different connection path through the network protocol stack, and a dependent block pointer that points to a different hierarchal layer of the same connection path through the network protocol stack.

17. The method of claim 14, wherein the act of transferring the two or more short-lived connections is performed during the slow-start phase of a TCP connection.

18. The method of claim 14, further comprising an act of inserting an intermediate driver data structure in the offload data structure, the intermediate driver including programming for deciphering and encapsulating incoming and outgoing data packets, as appropriate, wherein the outgoing data packets are packaged with one or more virtual local area network identifiers and incoming packets are stripped of one or more virtual local area network identifiers.

19. The method of claim 18, wherein the intermediate driver includes programming for securing network traffic over one or more network links using an JIPSEC protocol by performing one or more of adding and removing an authentication header to a data packet, and encrypting and decrypting the data packet, as appropriate.

20. The method of claim 14, further comprising:

an act of generating a handle for each layer of the intermediate software layers, wherein the peripheral device transfers the handle for each intermediate software layer to each intermediate software layer; and

an act of, when at least one of the intermediate software layers changes cached state, the at least one of the intermediate software layers updating the cached state of the peripheral device.

21. The method of claim 14, further comprising:

an act of detecting that one or more links being processed at one or more corresponding peripheral devices have failed, the one or more failed peripheral devices having been given processor control of the two or more short-lived network connections; and

an act of detecting a different one or more peripheral devices for handling processing control of the one or more links by receiving the two or more short-lived network connections.

22. The method of claim 21, further comprising transferring to the source component the one or more offload data structures and processing control of the one or more state objects from the one or more failed peripheral devices, thereby uploading processing control of the one or more links from the one or more failed peripheral devices to the source component.

23. The method of claim 22, further comprising an act of detecting a processing resource of the different one or more peripheral devices;

and adjusting the one or more state objects that have been uploaded from the one or more failed peripheral devices to match the detected resource of the different one or more peripheral devices, so that the one or more links can be processed at the different one or more peripheral devices rather than at the failed one or more peripheral devices.

24. The method of claim 23, wherein the one or more links are aggregated 802.3ad links.

25. The method of claim 21, further comprising:

an act of detecting a processing resource of the different one or more peripheral devices;

when one of the one or more offloaded state objects can be processed by the different one or more peripheral devices based on the detected processing resource, transferring processing control of the one of the one or more offloaded state objects to the different one or more peripheral devices; and

when the one or more offloaded state objects cannot be processed by the different one or more peripheral devices based on the detected processing resource, transferring processing control of the one of the one or more offloaded state objects to the host protocol stack.

26. The method of claim 25, wherein the one or more links are aggregated 802.3ad links.

27. The method of claim 1, wherein the computerized system further comprises a host processing unit, and wherein at least some of the intermediate software layers have a state object, and wherein the method further comprises:

an act of inserting one or more intermediate driver data structures within the offload data structure; and

wherein transferring comprises transferring from the source component device to the peripheral device the two or more state objects.

28. The method of claim 27, wherein an intermediate driver corresponding with at least one of the one or more intermediate driver data structures performs the act of detecting that one or more links being processed at one or more corresponding peripheral devices have failed, and the act of detecting a different one or more peripheral devices for handling processing control of the one or more links, and wherein the intermediate drive data structures further perform:

an act of detecting a processing resource of any of the detected one or more peripheral devices;

an act of detecting a processing resource of any of the detected one or more peripheral devices.

29. The method of claim 27, wherein the one or more intermediate driver data structures are inserted into the offload data structure prior to offloading processing control of the offload data structure to the one or more peripheral devices.

30. The method of claim 27, wherein the one or more intermediate driver data structures are inserted at the point of initiating an offload request of the offload data structure to the one or more peripheral devices.

31. The method of claim 30, wherein, at least one of the one or more intermediate drivers includes instructions for performing an act of directing the sub-data packet to a VLAN address based on a virtual LAN tag associated with the sub-data packet, the instructions further comprising and at least one of:

an act of receiving a multiplexed data packet;

an act of de-multiplexing the data packet into one or more sub-data packets;

an act of multiplexing a data packet; and

an act of sending a multiplexed data packet.

32. The method of claim 27, wherein, the offload data structure corresponds with two or more state objects corresponding to the same intermediate software layer, and wherein the two or more state objects point to a single state object at a lower software layer of a network protocol stack.

33. The method of claim 32, further comprising an act of transferring processing control of the entire inverted tree offload data structure to one or more of the one or more peripheral devices.

34. The method of claim 33, further comprising an act of transferring processing control of one or more of the state objects of the inverted tree offload data structure from the at least one of the one or more peripheral devices to the host protocol stack.

35. The method of claim 34, wherein the act of transferring from a source component device to one or more peripheral devices one or more state objects occurs in response to an act of detecting that at least one of the one or more peripheral devices has failed.

36. The method of claim 35, wherein an intermediate driver that corresponds with at least one of the one or more intermediate driver data structures performs the method comprising:

the act of detecting a different one or more peripheral devices that are for handling processing control of only the one or more links;

the act of detecting a different one or more peripheral devices that are for receiving processing control of the one or more links and one or more state objects; and

an act of detecting a processing resource of any of the detected one or more peripheral devices,

when the different one or more peripheral devices are capable of handling processing control of only the one or more links based on the detected processing resource, an act of transferring processing control of only the one or more links to the different one or more peripheral devices;

when the different one or more peripheral devices are capable of handling processing control of one or more links and one or more state objects based on the detected processing resource, an act of transferring processing control of the one or more links and the one or more offloaded state objects to the different one or more peripheral devices; and

an act of transferring processing control of any remaining of the one or more links and any remaining of the one or more offloaded state objects to the host protocol stack.

37. A computer program product comprising one or more computer-readable storage media storing computer-executable instructions that, when executed by one or more processors at the host computing system, cause the host computing system to perform the method recited in claim 1.

38. The computer program product of claim 37, wherein the computer-executable instructions, when executed by the one or more processors, further cause the computerized system to perform the following:

an act of generating a handle for each layer of the intermediate software layers, wherein the destination component is a NIC, and the NIC transfers the handle for each intermediate software layer to each intermediate software layer; and

an act of, when at least one of the intermediate software layers changes cached state, the at least one of the intermediate software layers updating the cached state of the NIC.

39. The computer program product of claim 37, wherein the computer-executable instructions, when executed by the one or more processors, further cause the computerized system to perform the following:

an act of detecting a processing resource of the different one or more peripheral devices;

when one of the one or more offloaded state objects can be processed by the different one or more peripheral devices based on the detected processing resource, transferring processing control of the one of the one or more offloaded state objects to the different one or more peripheral devices; and

when the one or more offloaded state objects cannot be processed by the different one or more peripheral devices based on the detected processing resource, transferring processing control of the one of the one or more offloaded state objects to the host protocol stack.