Method and apparatus for offloading message segmentation to a network interface card

• US 20040062275A1
• Filed: 09/27/2002
• Published: 04/01/2004
• Est. Priority Date: 09/27/2002
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Siddabathuni, Ajoy C.
• Granted Patent: US 7,283,522 B2
• Time in Patent Office: Days
• US Class Current: 370/474
• CPC Class Codes: H04L 47/36 by determining packet size, e.g. maximum transfer unit [MTU]
• 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 69/16 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 69/166 IP fragmentation; TCP segmentation

Abstract

One embodiment of the present invention provides a system that facilitates offloading message segmentation from a central processing unit onto a network interface card. The system operates by first receiving a TSO-send message at the network interface card, wherein the TSO-send message contains information about the message to be sent. Next, the system uses a header address from the TSO-send message to access a message header from memory using remote direct memory access. The system then uses a payload address from the TSO-send message to access a payload from memory that contains message data using remote direct memory access. Finally, the network interface card segments the payload into a set of maximum segment size (mss) segments and transmits the set of mss segments on the network.

Claims

1. A method for offloading message segmentation from a central processing unit to a network interface card, comprising:

receiving a Message send packet at the network interface card from the central processing unit, wherein the Message send packet contains information about a message to be sent;

using a header address from the Message send packet to access a message header from memory using remote direct memory access;

using a payload address from the Message send packet to access a payload containing message data from memory using remote direct memory access;

segmenting the payload into a set of maximum segment size segments; and

transmitting the payload on a network by transmitting the set of maximum segment size segments.

2. The method of claim 1, wherein the Message send packet includes a maximum segment size that has been negotiated by a Transmission Control Protocol (TCP) stack.

3. The method of claim 1, wherein segmenting the payload involves updating Internet Protocol (IP) parameters and Transmission Control Protocol (TCP) parameters for each segment.

4. The method of claim 1, wherein the Message send packet includes a data length for the payload.

5. The method of claim 1, wherein if a last segment of the payload is less than a specified minimum size, the method further comprises padding the last segment with bytes until it is at least the specified minimum size.

6. The method of claim 1, further comprising processing a segment acknowledge message for each segment.

7. The method of claim 6, further comprising sending an acknowledge message to a Transmission Control Protocol (TCP) stack that originated the Message send packet after receiving the segment acknowledge message for each segment.

8. The method of claim 1, wherein the message header includes an Ethernet header, an Internet Protocol (IP) header, and a Transmission Control Protocol (TCP) header for the message.

9. A computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for offloading message segmentation from a central processing unit to a network interface card, the method comprising:

receiving a Message send packet at the network interface card from the central processing unit, wherein the Message send packet contains information about a message to be sent;

using a header address from the Message send packet to access a message header from memory using remote direct memory access;

using a payload address from the Message send packet to access a payload containing message data from memory using remote direct memory access;

segmenting the payload into a set of maximum segment size segments; and

transmitting the payload on a network by transmitting the set of maximum segment size segments.

10. The computer-readable storage medium of claim 9, wherein the Message send packet includes a maximum segment size that has been negotiated by a Transmission Control Protocol (TCP) stack.

11. The computer-readable storage medium of claim 9, wherein segmenting the payload involves updating Internet Protocol (IP) parameters and Transmission Control Protocol (TCP) parameters for each segment.

12. The computer-readable storage medium of claim 9, wherein the Message send packet includes a data length for the payload.

13. The computer-readable storage medium of claim 9, wherein if a last segment of the payload is less than a specified minimum size, the method further comprises padding the last segment with bytes until it is at least the specified minimum size.

14. The computer-readable storage medium of claim 9, the method further comprising processing a segment acknowledge message for each segment.

15. The computer-readable storage medium of claim 14, the method further comprising sending an acknowledge message to a Transmission Control Protocol (TCP) stack that originated the Message send packet after receiving the segment acknowledge message for each segment.

16. The computer-readable storage medium of claim 9, wherein the message header includes an Ethernet header, an Internet Protocol (IP) header, and a Transmission Control Protocol (TCP) header for the message.

17. An apparatus for offloading message segmentation from a central processing unit to a network interface card, comprising:

a receiving mechanism that is configured to receive a Message send packet at the network interface card from the central processing unit, wherein the Message send packet contains information about a message to be sent;

an accessing mechanism that is configured to use a header address from the Message send packet to access a message header from memory using remote direct memory access;

wherein the accessing mechanism is further configured to use a payload address from the Message send packet to access a payload containing message data from memory using remote direct memory access;

a segmenting mechanism that is configured to segment the payload into a set of maximum segment size segments; and

a transmitting mechanism that is configured to transmit the payload on a network by transmitting the set of maximum segment size segments.

18. The apparatus of claim 17, wherein the Message send packet includes a maximum segment size that has been negotiated by a Transmission Control Protocol (TCP) stack.

19. The apparatus of claim 17, wherein the segmenting mechanism is further configured to update Internet Protocol (IP) parameters and Transmission Control Protocol (TCP) parameters for each segment.

20. The apparatus of claim 17, wherein the Message send packet includes a data length for the payload.

21. The apparatus of claim 17, further comprising a padding mechanism that is configured to pad a last segment with bytes until it is at least a specified minimum size.

22. The apparatus of claim 17, further comprising a processing mechanism that is configured to process a segment acknowledge message for each segment.

23. The apparatus of claim 22, further comprising a sending mechanism that is configured to send an acknowledge message to a Transmission Control Protocol (TCP) stack that originated the Message send packet after receiving the segment acknowledge message for each segment.

24. The apparatus of claim 17, wherein the message header includes an Ethernet header, an Internet Protocol (IP) header, and a Transmission Control Protocol (TCP) header for the message.