System and method for TCP/IP offload independent of bandwidth delay product

• US 7,313,623 B2
• Filed: 08/29/2003
• Issued: 12/25/2007
• Est. Priority Date: 08/30/2002
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Elzur, Uri, McDaniel, Scott S., Fan, Frankie, Lindsay, Steven B
• Primary Examiner(s): Tran; Philip
• Application Number:
  US10/652,183
• Publication Number:
  US 20040042464A1
• Time in Patent Office: 1,579 Days
• Field of Search: 709227-228, 709/230, 709223-224, 709/250, 709/232, 709/242, 370/395.52, 370/235
• US Class Current: 709/227
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9063 Intermediate storage in different physical parts of a node or terminal
• 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 69/12 Protocol engines
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/162 involving adaptations of sockets based mechanisms secure socket layer H04L63/168
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/166 IP fragmentation; TCP segmentation

Abstract

Aspects of the invention may provide TCP offload, which may include acquiring TCP connection variables from a host and managing at least one TCP connection using the acquired TCP connection variables. At least a portion of the acquired TCP connection variables may be updated and at least some of the updated TCP connection variables may be transferred back to the host. In an aspect of the invention, the TCP connection variables may be variables that are independent of bandwidth delay product. At least a portion of the updated TCP connection variables may be utilized by the host to process the TCP connection or another TCP connection. The host may push the variables onto the stack and the TOE may pull the variables from the stack. Also, updated TCP connection variables may be pushed on the stack by the TOE and pulled from the stack by the host.

Claims

1. A system for providing TCP/IP offload, comprising:

a Transmission Control Protocol/Internet Protocol (TCP/IP) offload engine (TOE) for operatively coupling to a host, wherein when said TCP/IP Offload Engine and said host are operatively coupled, said host transfers control of at least a portion of Transmission Control Protocol (TCP) connection variables to said TCP/IP Offload Engine, said TCP/IP Offload Engine updates said at least a portion of said TCP/IP Offload Engine connection variables, and said TCP/IP Offload Engine provides said at least a portion of said undated TCP connection variables to said host.

2. The system according to claim 1, wherein when said TCP/IP Offload Engine and host are operatively coupled, said host transfers control of segment-variant TCP connection variables to said TCP/IP Offload Engine and said TCP/IP Offload Engine provides updated TOP segment-variant TCP connection variables to said host.

3. The method according to claim 2, wherein said Transmission Control Protocol segment-variant Transmission Control Protocol connection variables comprise at least one of the following:

IP packet identifier;

time remaining for retransmission;

time remaining for delay acknowledgement;

time remaining for keep alive;

congestion window variables comprising;

congestion window (SND_CWIN); and

slow start threshold (SSTHRESH);

round trip time variables comprising;

smoothed round trip time (RTT);

smoothed delta (DELTA); and

time remaining for PUSH; and

Transmission Control Protocol state and timestamp send and receive sequence variables comprising;

sequence number for first un-ACK'"'"'d data (SND_UNA);

sequence number for next send (SND_NXT);

maximum sequence number ever sent (SND_MAX);

maximum send window (MAX_WIN);

sequence number for next receive (RCV_NXT); and

receive window size (RCV_WND).

4. The system according to claim 1,

wherein when said TCP/IP Offload Engine and said host are operatively coupled, said TCP/IP Offload Engine receives from said host a snapshot of at least one of:

connection-invariant Transmission Control Protocol connection variables and segment-invariant Transmission Control Protocol connection variables, said TCP/IP Offload Engine transferring updated at least one of;

connection-invariant Transmission Control Protocol connection variables and segment-invariant Transmission Control Protocol connection variables to said host; and

wherein during operation, said TCP/IP Offload Engine utilizes transferred segment-variant Transmission Control Protocol connection variables and said snapshot of said at least one of said connection-invariant Transmission Control Protocol connection variables and said segment-invariant Transmission Control Protocol connection variables to process at least one of the following;

incoming and outgoing Transmission Control Protocol segments.

5. The system according to claim 4, wherein during operation, said TCP/IP Offload Engine utilizes said transferred segment-variant Transmission Control Protocol connection variables and a snapshot of at least one of:

connection-invariant Transmission Control Protocol connection variables and segment-invariant Transmission Control Protocol connection variables to independently process incoming Transmission Control Protocol segments.

6. The system according to claim 1, wherein when said TCP/IP Offload Engine and said host are operatively coupled, said TCP/IP Offload Engine receives from said host a snapshot of connection-invariant Transmission Control Protocol connection variables and segment-invariant Transmission Control Protocol connection variables.

7. The system according to claim 1, wherein when said TCP/IP Offload Engine and said host are operatively coupled, said TCP/IP Offload Engine receives from said host a snapshot of Transmission Control Protocol connection variables that are not segment-variant Transmission Control Protocol connection variables.

8. The system according to claim 1, wherein when said TCP/IP Offload Engine and said host are operatively coupled, said host posts at least one of the following:

a buffer that is utilized by any Transmission Control Protocol connection, a buffer that is dedicated to one or more Transmission Control Protocol connections, and an application buffer.

9. The system according to claim 1, wherein during operation, said TCP/IP Offload Engine manages said Transmission Control Protocol connection.

10. The system according to claim 1, wherein during operation, said TCP/IP Offload Engine manages at least one of the following:

segmentation, acknowledgement processing, windowing and congestion avoidance.

11. The system according to claim 1, wherein during operation, said TCP/IP Offload Engine maintains exclusive read-write access to offloaded segment-variant variables.

12. The system according to claim 1, wherein during operation, said TCP/IP Offload Engine exclusively updates offloaded segment-variant variables.

13. The system according to claim 1, wherein when said TCP/IP Offload Engine and said host are operatively coupled, said host maintains read-write access to segment-invariant variables.

14. The system according to claim 1, wherein during operation, said TCP/IP Offload Engine has read-only access to segment-invariant variables.

15. The system according to claim 1, wherein:

when said TCP/IP Offload Engine and said host are operatively coupled, said TCP/IP Offload Engine receives from said host a message concerning a change in a particular Transmission Control Protocol connection variable whose control was not transferred to said TCP/IP Offload Engine, and

during operation, said TCP/IP Offload Engine updates said particular Transmission Control Protocol connection variable.

16. The system according to claim 1, wherein said Transmission Control Protocol connection is an ESTABLISHED state.

17. The system according to claim 1, wherein said Transmission Control Protocol connection variables are Transmission Control Protocol connection variables that are independent of bandwidth delay product.

18. The system according to claim 1, wherein when said TCP/IP Offload Engine and said host are operatively coupled, said TCP/IP Offload Engine receives connection setups from said host.

19. The system according to claim 18, wherein when said TCP/IP Offload Engine and said host are operatively coupled, the system provides resistance to DoS attacks by allowing said host to handle said connection setups.

20. The system according to claim 1, wherein when said TCP/IP Offload Engine and said host are operatively coupled, said host handles all TCP states exclusive of an ESTABLISHED state which may be offloaded to said TCP/IP Offload Engine.

21. The system according to claim 1, wherein during operation, said TCP/IP Offload Engine handles only connections that are in performance sensitive states.

22. The system according to claim 1, wherein when said TCP/IP Offload Engine and said host are operatively coupled, said host processes resource utilization statistics in helping to determine which connections to offload and which connections to upload.

23. The system according to claim 1, wherein when said TCP/IP Offload Engine and said host are operatively coupled, said host determines which connections to offload and which connections to upload.

24. The system according to claim 1, wherein during operation, at least one of:

said TCP/IP Offload Engine and a device driver software for said TCP/IP Offload Engine determines at least one of;

Transmission Control Protocol connections to offload and Transmission Control Protocol connections to upload.

25. A system for providing connection offload, comprising:

a network interface card (NIC) for operatively coupling to a host, wherein when said NIC and said host are operatively coupled, for a particular connection offloaded to said NIC, control of state information is split between said host and said NIC, said NIC updates at least a portion of updated connection variables for said particular connection, and said NIC unloads said at least a portion of said updated connection variables for said particular connection to said host.

26. The system according to claim 25, wherein during operation, said particular connection employs a connection-oriented transport layer protocol (TLP).

27. The system according to claim 26, wherein during operation, said connection-oriented TLP comprises a Transmission Control Protocol.

28. The system according to claim 25, wherein when said NIC and said host are operatively coupled, said host transfers control of segment variant variables corresponding to said particular connection to said NIC.

29. A method for providing TCP/IP offload, comprising:

receiving by a TCP/IP Offload Engine transfer of control of connection variables of a particular TCP connection from a host and a snapshot of remaining connection variables whose control was not transferred to said TCP/IP Offload Engine from said host;

managing said particular Transmission Control Protocol connection via said TCP/IP Offload Engine using said at least a portion of said connection variables transferred to said TCP/IP Offload Engine and at least a portion of said snapshot; and

updating at least a portion of said connection variables and a portion of said snapshot and transferring said updated at least said portion of said connection variables and said portion of said snapshot back to said host.

30. The method according to claim 29, wherein said one or more connection variables of said particular Transmission Control Protocol connection transferred to said TCP/IP Offload Engine comprise at least one segment-variant variables of said particular Transmission Control Protocol connection.

31. The method according to claim 29, wherein said connection variables of said particular Transmission Control Protocol connection transferred to said TCP/IP Offload Engine lacks segment-invariant variables of said particular Transmission Control Protocol connection.

32. The method according to claim 29, wherein said connection variables of said particular Transmission Control Protocol connection transferred to the TCP/IP Offload Engine lacks segment-invariant variables and connection-invariant variables of said particular Transmission Control Protocol connection.

33. The method according to claim 29, comprising:

determining if at least one of said connection variables controlled by said host have changed;

notifying said TCP/IP Offload Engine of changes in said at least one connection variables controlled by said host that has changed; and

updating said connection variables in said TCP/IP Offload Engine in accordance with said notified changes.

34. A method for providing TCP/IP offload, comprising:

receiving transfer of control of segment-variant variables by a TCP/IP Offload Engine from a host;

receiving a snapshot of segment-invariant variables and connection-invariant variables by said TCP/IP Offload Engine;

independently processing incoming Transmission Control Protocol packets via said TCP/IP Offload Engine based upon said segment-variant variables and said snapshot; and

updating at least a portion of said snapshot and at least a portion of said segment-variant variables and transferring at least a portion of said updated at least said portion of said snapshot and at least said portion of said updated segment-variant variables back to said host.

35. A method for processing a Transmission Control Protocol connection, comprising:

establishing a Transmission Control Protocol connection between a TCP/IP Offload Engine and a host;

sharing a control plane for said Transmission Control Protocol connection by said TCP/IP Offload Engine with said host;

updating Transmission Control Protocol connection variables by said TCP/IP Offload Engine; and

communicating said updated Transmission Control Protocol connection variables from said TCP/IP Offload Engine to said host.

36. The method according to claim 35, wherein said sharing of said control plane comprises receiving control of segment-variant variables corresponding to said Transmission Control Protocol connection by said TCP/IP Offload Engine.

37. The method according to claim 35, comprising uploading said Transmission Control Protocol connection to said host from said TCP/IP Offload Engine.

38. The method according to claim 37, wherein uploading said Transmission Control Protocol connection comprises transferring control of segment-variant variables corresponding to said Transmission Control Protocol connection to said host.

39. The method according to claim 37, comprising offloading said uploaded Transmission Control Protocol connection to said TCP/IP Offload Engine from said host.

40. The method according to claim 37, wherein offloading said uploaded Transmission Control Protocol connection comprises transferring said control of said segment-variant variables corresponding to said uploaded Transmission Control Protocol connection to said TCP/IP Offload Engine.

41. A method for Transmission Control Protocol offload, the method comprising:

acquiring Transmission Control Protocol connection variables from a host;

managing at least one Transmission Control Protocol connection using said acquired Transmission Control Protocol connection variables;

updating at least a portion of said acquired Transmission Control Protocol connection variables; and

transferring said updated at least a portion of said acquired Transmission Control Protocol connection variables to said host.

42. The method according to claim 41, wherein said Transmission Control Protocol connection variables are independent of bandwidth delay product.

43. The method according to claim 41, comprising utilizing at least a portion of said updated at least said portion of said acquired TCP connection variables to process said at least said at least one Transmission Control Protocol connection by said host.

44. The method according to claim 41, comprising pulling said Transmission Control Protocol connection variables from a stack.

45. The method according to claim 41, comprising pushing said updated at least a portion of said acquired Transmission Control Protocol connection variables onto a stack.

46. A machine-readable storage, having stored thereon, a computer program having at least one code section for providing Transmission Control Protocol offload, the at least one code section being executable by a machine for causing the machine to perform steps comprising:

acquiring TCP connection variables from a host;

managing at least one Transmission Control Protocol connection using said acquired Transmission Control Protocol connection variables;

updating at least a portion of said acquired Transmission Control Protocol connection variables; and

transferring said updated at least a portion of said acquired Transmission Control Protocol connection variables to said host.

47. The machine-readable storage according to claim 46, wherein said Transmission Control Protocol connection variables are independent of bandwidth delay product.

48. The machine-readable storage according to claim 46, comprising code for utilizing at least a portion of said updated at least said portion of said acquired Transmission Control Protocol connection variables to process said at least said at least one Transmission Control Protocol connection by said host.

49. The machine-readable storage according to claim 46, comprising code for pulling said Transmission Control Protocol connection variables from a stack.

50. The machine-readable storage according to claim 46, comprising code for pushing said updated at least a portion of said acquired Transmission Control Protocol connection variables onto a stack.