Parsing a packet header

• US 20040078480A1
• Filed: 10/18/2002
• Published: 04/22/2004
• Est. Priority Date: 10/14/1997
• Status: Active Grant

• Current Assignee: Alacritech, Inc.
• Original Assignee: A Tech LLC
• Inventors: Higgen, David A., Philbrick, Clive M., Boucher, Laurence B., Craft, Peter K., Blightman, Stephen E. J., Starr, Daryl D.
• Granted Patent: US 8,782,199 B2
• Time in Patent Office: Days
• US Class Current: 709/237
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 47/27 Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets
• CPC Class Codes: H04L 47/43 Assembling or disassembling of packets, e.g. segmentation and reassembly [SAR]
• 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 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• 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
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

An intelligent network interface card (INIC) or communication processing device (CPD) works with a host computer for data communication. The device provides a fast-path that avoids protocol processing for most messages, greatly accelerating data transfer and offloading time-intensive processing tasks from the host CPU. The host retains a fallback processing capability for messages that do not fit fast-path criteria, with the device providing assistance such as validation even for slow-path messages, and messages being selected for either fast-path or slow-path processing. A context for a connection is defined that allows the device to move data, free of headers, directly to or from a destination or source in the host. The context can be passed back to the host for message processing by the host. The device 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 devoted to transmit, receive and utility processing, providing full duplex communication for four Fast Ethernet nodes.

Claims

1. A method for use with a computer system, comprising:

receiving a packet that includes a header, the header indicating at least one characteristic that is associated with a layer of a multiple layer protocol stack;

parsing the packet with a network controller to extract said at least one characteristic; and

passing a handle from the network controller to indicate said at least one characteristic.

2. The method of claim 1, wherein the act of passing comprises:

passing the handle to another layer of the protocol stack.

3. The method of claim 1, wherein said at least one characteristic comprises:

a port number associated with an application program.

4. The method of claim 1, wherein the layer comprises a data link layer.

5. The method of claim 1, wherein said at least one characteristic comprises:

a type of the packet.

6. The method of claim 1, wherein the handle associates the packet with a flow.

7. The method of claim 1, further comprising:

selectively transmitting acknowledgement packets based on said at least one characteristic.

8. The method of claim 1, further comprising:

storing data associated with the packet in a region of memory that is used by execution of an application based on said at least one characteristic.

9. The method of claim 1, wherein the layer comprises a transport layer.

10. The method of claim 1, wherein the act of receiving comprises:

receiving the packet from a network.

11. The method of claim 1, wherein the handle comprises an IP address and a TCP port.

12. The method of claim 1, wherein the handle comprises a number corresponding to a context.

13. The method of claim 1, wherein the handle is passed to the network controller.

14. The method of claim 1, further comprising:

using the packet to obtain memory space for another packet.

36. The method of claim 8, wherein the network controller comprises means for parsing the packet, and wherein said at least one characteristic is a combination of a TCP source port, a TCP destination port, an IP source address, and an IP destination address, and wherein the handle associates the packet with a flow.

37. The method of claim 8, wherein the computer system comprises:

means for determining a memory address at which to store data.

38. The method of claim 8, wherein the network controller is a TCP offload device.

39. The method of claim 8, further comprising:

passing an indication of said at least one characteristic to the network controller, and wherein the network controller matches said at least one characteristic extracted from the packet with said at least one characteristic passed to the network interface device.

40. The method of claim 8, further comprising:

receiving onto the network controller from the protocol stack an indication of the region of memory.

41. The method of claim 8, further comprising:

a step for receiving onto the network controller from the protocol stack an indication of the region of memory.

42. The method of claim 8, wherein the handle is a header buffer, and wherein the header buffer contains status information about the packet.

43. The method of claim 8, wherein the handle is a header buffer, and wherein the header buffer specifies a fast-path connection, the fast-path connection being identified by a TCP source port, a TCP destination port, an IP source address, and an IP destination address.

15. An apparatus for use with a computer system capable of executing software of a protocol stack to extract at least one characteristic of a packet, comprising:

an interface adapted to receive the packet, the packet including a header indicating said at least one characteristic; and

a circuit adapted to;

parse the header to extract said at least one characteristic of the packet without causing the computer system to execute the software, and

process the packet based on the extracted characteristic.

16. The apparatus of claim 15, wherein said at least one characteristic comprises:

a port number being associated with an application program.

17. The apparatus of claim 15, wherein the circuit comprises means for parsing the header.

18. The apparatus of claim 15, wherein said at least one characteristic comprises:

a type of the packet.

19. The apparatus of claim 15, wherein the circuit is further adapted to:

use said at least one characteristic to associate the packet with a flow.

20. The apparatus of claim 15, wherein the circuit is further adapted to:

store data from the packet in a final destination in a memory.

21. The apparatus of claim 15, wherein the apparatus comprises a network controller.

22. A computer system comprising:

a processor adapted to execute software of a network stack to extract at least one characteristic of a packet; and

a peripheral device adapted to;

receive the packet, the packet including a header indicating said at least one characteristic,

parse the header to extract said at least one characteristic, and

at least partially process the packet based on the at least one extracted characteristic.

23. The computer system of claim 22, wherein the software comprises a network layer.

24. The computer system of claim 22, wherein said at least one characteristic comprises:

a port number associated with an application program.

25. The computer of claim 22, further comprising:

means for determining a memory address at which to store data.

26. The computer system of claim 22, wherein said at least one characteristic comprises:

a type of the packet.

27. The computer system of claim 22, wherein the peripheral device is further adapted to:

use said at least one characteristic to associate the packet with a flow.

28. The computer system of claim 22, wherein the peripheral device is further adapted to:

provide zero-copy support for an upper layer protocol layer, wherein the upper layer protocol layer is a layer that is higher than a transport layer.

29. The computer system of claim 22, wherein the peripheral device comprises a network controller.

30. The computer system of claim 28, wherein said at least one characteristic is a combination of a TCP source port, a TCP destination port, an IP source address, and an IP destination address.

31. The computer system of claim 30, wherein the peripheral device receives an indication of a destination address from the processor, and wherein the peripheral device provides said zero-copy support by transferring a data payload of the packet from the peripheral device directly into the destination address.

32. The computer system of claim 31, wherein the stack includes a transport processing layer, and wherein the stack performs substantially no TCP processing on the packet, and wherein the peripheral device performs substantially all TCP processing on the packet.

33. The computer system of claim 22, wherein the characteristic is that the packet is a fast-path packet.

34. The computer system of claim 22, wherein the peripheral device is further adapted to:

choose between slow-path processing the packet and fast-path processing the packet.

35. The computer system of claim 22, wherein the peripheral device is further adapted to:

receive an indication of said at least one characteristic onto said peripheral device from said processor, the peripheral device matching said at least one characteristic extracted from the header with said at least one characteristic received onto the peripheral device from said processor.

44. A method for use with a computer system, comprising:

receiving a packet that includes a header, the header including a TCP source port, a TCP destination port, an IP source address, and an IP destination address, and wherein a TCP connection is identified by the TCP source port, the TCP destination port, the IP source address, and the IP destination address;

parsing the packet with a network controller to extract said TCP source port, said TCP destination port, said IP source address and said IP destination address; and

passing an indication of the TCP connection from the network controller.

45. A computer system comprising:

a processor adapted to execute software of a protocol stack, the protocol stack having a TCP protocol processing layer; and

a peripheral device adapted to;

receive a packet from a network, the packet including a header, the header indicating a TCP source port, a TCP destination port, an IP source address, and an IP destination address;

parse the header to extract said TCP source port, said TCP destination port, said IP source address, and said IP destination address;

determine based at least in part on said TCP source port, said TCP destination port, said IP source address, and said IP destination address whether the packet is a fast-path packet; and

perform at least some TCP protocol processing on the packet if the packet is determined to be a fast-path packet.