Fast-path apparatus for transmitting data corresponding to a TCP connection

• US 7,673,072 B2
• Filed: 06/25/2007
• Issued: 03/02/2010
• Est. Priority Date: 10/14/1997
• Status: Expired due to Term

• Current Assignee: Alacritech, Inc.
• Original Assignee: Alacritech, Inc.
• Inventors: Higgen, David A., Philbrick, Clive M., Boucher, Laurence B., Craft, Peter K., Blightman, Stephen E. J., Starr, Daryl D.
• Primary Examiner(s): JEAN GILLES, JUDE
• Application Number:
  US11/821,820
• Publication Number:
  US 20080126553A1
• Time in Patent Office: 981 Days
• Field of Search: 709/245, 709230-234, 709/239, 709/250, 370/235, 370/468, 370/237, 370/230, 370/233, 370/234
• US Class Current: 709/245
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• 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 69/22 Parsing or analysis of headers

Abstract

A system for protocol processing in a computer network has an intelligent network interface card (INIC) or communication processing device (CPD) associated with a host computer. The INIC provides a fast-path that avoids protocol processing for most large multi-packet messages, greatly accelerating data communication. The INIC also assists the host for those message packets that are chosen for processing by host software layers. A communication control block for a message is defined that allows DMA controllers of the INIC to move data, free of headers, directly to or from a destination or source in the host. The context is stored in the INIC as a communication control block (CCB) that can be passed back to the host for message processing by the host. The INIC contains specialized hardware circuits that are much faster at their specific tasks than a general purpose CPU. A preferred embodiment includes a trio of pipelined processors with separate processors devoted to transmit, receive and management processing, with full duplex communication for four fast Ethernet nodes.

Claims

1. A method comprising:

establishing, at a host computer, a transport layer connection, including creating a context that includes protocol header information for the connection;

transferring the protocol header information to an interface device;

transferring data from the network host to the interface device, after transferring the protocol header information to the interface device;

dividing, by the interface device, the data into segments;

creating headers for the segments, by the interface device, from a template header containing the protocol header information; and

prepending the headers to the segments to form transmit packets.

2. The method of claim 1, further comprising transferring status information for the context to the interface device during the same operation as transferring protocol header information to the interface device.

3. The method of claim 1, wherein creating headers for the segments includes adding status information to the template header.

4. The method of claim 1, wherein the protocol header information includes Internet Protocol (IP) addresses and Transmission Control Protocol (TCP) ports for the connection, and creating headers for the segments includes forming headers containing the IP addresses and TCP ports.

5. The method of claim 1, wherein the protocol header information includes a Media Access Control (MAC) layer address, and creating headers for the segments includes forming headers containing the MAC layer address.

6. The method of claim 1, further comprising adding to the context a descriptor for a buffer, in a memory of the computer, that has been allocated for application data.

7. The method of claim 1, further comprising receiving, by the interface device, receive packets that correspond to the context, and updating the context by the interface device to account for the receive packets.

8. The method of claim 1, further comprising transmitting the transmit packets on a network.

9. A method comprising:

creating, at a computer, a context including protocol information and status information for a network connection, the protocol information providing a template header for the network connection;

transferring the protocol information and status information to an interface device;

transferring data from the computer to the interface device, after transferring the protocol information and status information to the interface device;

dividing, by the interface device, the data into segments;

creating headers for the segments, by the interface device, from the template header;

prepending the headers to the segments to form packets; and

transmitting the packets on a network.

10. The method of claim 9, wherein creating headers for the segments includes adding current status information to the template header, the current status information being different than the status information that was transferred to the interface device.

11. The method of claim 9, wherein the protocol header information includes Internet Protocol (IP) addresses and Transmission Control Protocol (TCP) ports for the connection, and creating headers for the segments includes forming headers containing the IP addresses and TCP ports.

12. The method of claim 9, wherein the protocol header information includes a Media Access Control (MAC) layer address, and creating headers for the segments includes forming headers containing the MAC layer address.

13. The method of claim 9, further comprising transferring to the interface device a descriptor for a buffer, in a memory of the computer, that has been allocated for application data that is transferred according to the protocol information.

14. The method of claim 9, further comprising receiving, by the interface device, receive packets that correspond to the protocol information, and updating the status information by the interface device to account for the receive packets.

15. A method comprising:

establishing, at a computer, a Transmission Control Protocol (TCP) connection corresponding to a context that includes status information and Internet Protocol (IP) addresses and TCP ports for the connection;

transferring the context to an interface device;

transferring data from the network host to the interface device;

dividing, by the interface device, the data into segments;

creating headers for the segments, by the interface device, from a template header that includes the IP addresses and TCP ports; and

prepending the headers to the segments to form transmit packets.

16. The method of claim 15, wherein transferring the context to the interface device occurs prior to transferring the data to the interface device.

17. The method of claim 15, wherein creating headers for the segments includes adding current status information to the template header, the current status information being different than the status information that was transferred to the interface device.

18. The method of claim 15, wherein the template header includes a Media Access Control (MAC) layer address, and creating headers for the segments includes forming headers containing the MAC layer address.

19. The method of claim 15, wherein the context includes a Media Access Control (MAC) layer address, and creating headers for the segments includes forming headers containing the MAC layer address.

20. The method of claim 15, further comprising adding to the context a descriptor for a buffer, in a memory of the computer, that has been allocated for application data.

21. The method of claim 15, further comprising receiving, by the interface device, receive packets that correspond to the context, and updating the status information by the interface device to account for the receive packets.