Fast-path processing for receiving data on TCP connection offload devices

• US 20020161919A1
• Filed: 05/06/2002
• Published: 10/31/2002
• Est. Priority Date: 10/14/1997
• Status: Active Grant

• 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.
• Granted Patent: US 7,089,326 B2
• Time in Patent Office: Days
• US Class Current: 709/238
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04L 67/62 Establishing a time schedule for servicing the requests
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context
• 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 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/166 IP fragmentation; TCP segmentation
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A network interface device provides a fast-path that avoids most host TCP and IP protocol processing for most messages. The host retains a fallback slow-path processing capability. In one embodiment, generation of a response to a TCP/IP packet received onto the network interface device is accelerated by determining the TCP and IP source and destination information from the incoming packet, retrieving an appropriate template header, using a finite state machine to fill in the TCP and IP fields in the template header without sequential TCP and IP protocol processing, combining the filled-in template header with a data payload to form a packet, and then outputting the packet from the network interface device by pushing a pointer to the packet onto a transmit queue. A transmit sequencer retrieves the pointer from the transmit queue and causes the corresponding packet to be output from the network interface device.

Claims

1. A system for receiving information from a network, the system comprising:

a first device coupled to the network and receiving a packet including data and protocol information from the network, the first device including a mechanism that processes the protocol information, and

a second device coupled to the network and including a processor executing instructions that establish a TCP connection,

wherein the data is placed in a destination by the first device when the first device detremines that the packet corresponds to the TCP connection.

2. The system of claim 1, wherein the first device is an intelligent network interface card (INIC) that is coupled to the second device.

3. The system of claim 1, wherein the first device is a communication processing device (CPD) that is integrated into the second device.

4. The system of claim 1, wherein the TCP connection is identified by an IP source address, an IP destination address, a TCP source port and a TCP destination port.

5. The system of claim 1, wherein the instructions cause control of the TCP connection to be passed from the second device to the first device.

6. The system of claim 5, wherein the first device includes a second processor executing a code that causes control of the TCP connection to be passed from the first device to the second device.

7. The system of claim 6, wherein a second packet received from the network and corresponding to the TCP connection is generally processed by the second device when the second device has control of the TCP connection.

8. The system of claim 1, wherein the first device is coupled to the second device by a bus.

9. The system of claim 1, wherein the first device includes means for processing a TCP header.

10. A system for receiving information from a network, the system comprising:

a first device coupled to the network to receive a packet including data and protocol information from the network, the first device including a mechanism configured to process the protocol information, and

a second device coupled to the network and including a processor adapted to establish a TCP connection and cause control of the TCP connection to be passed to the first device,

wherein the data is placed in a destination by the first device when the packet corresponds to the TCP connection and the first device is controlling the TCP connection.

11. The system of claim 10, wherein the first device is an intelligent network interface card (INIC) that is coupled to the second device.

12. The system of claim 10, wherein the first device is a communication processing device (CPD) that is integrated into the second device.

13. The system of claim 10, wherein the TCP connection is identified by an IP source address, an IP destination address, a TCP source port and a TCP destination port.

14. The system of claim 10, wherein the instructions cause control of the TCP connection to be passed from the second device to the first device.

15. The system of claim 14, wherein the first device includes a second processor executing a code that causes control of the TCP connection to be passed from the first device to the second device.

16. The system of claim 15, wherein a second packet received from the network and corresponding to the TCP connection is generally processed by the second device when the second device has control of the TCP connection.

17. The system of claim 10, wherein the first device is coupled to the second device by a bus.

18. The system of claim 10, wherein the first device includes means for processing a TCP header.

20. The system of claim 19, wherein the processor has means for causing the TCP connection to be passed from the second device to the first device.

19. A system for receiving information from a network, the system comprising:

a first device coupled to the network for receiving a packet including data and protocol information from the network, the first device including means for processing the protocol information, and

a second device coupled to the network and including a processor having means for establishing a TCP connection,

wherein the data is placed in a destination by the first device when the packet corresponds to the TCP connection and the first device is controlling the TCP connection.