System and method for computing a blind checksum in a host ethernet adapter (HEA)

• US 20060221969A1
• Filed: 04/01/2005
• Published: 10/05/2006
• Est. Priority Date: 04/01/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chang, Chih-jen, Damon, Philippe, Vaidhyanathan, Natarajan, Calvignac, Jean Louis, Verplanken, Fabrice Jean, Basso, Claude, Verrilli, Colin Beaton, Fuhs, Ronald Edward, Willenborg, Scott Michael
• Granted Patent: US 7,606,166 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• 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

Abstract

A system and method for computing a blind checksum includes a host Ethernet adapter (HEA) with a system for receiving a packet. The system determines whether or not the packet is in Internet protocol version four (IPv4). If the packet is not in IPv4, the system computes the checksum of the packet. If the packet is in IPv4, the system determines whether the packet is in transmission control protocol (TCP) or user datagram protocol (UDP). If the packet is not in either of TCP or UDP the system attaches a pseudo-header to the packet and computes the checksum of the packet based on the pseudo-header and the IPv4 standard.

Claims

1. A method for computing a blind checksum in a host Ethernet adapter (HEA) comprising:

receiving a packet in the HEA;

determining whether the packet is in Internet protocol version four (IPv4);

computing by the HEA, if the packet is not in IPv4, the checksum of the packet;

determining, if the packet is in IPv4, whether the packet is in transmission control protocol (TCP) or user datagram protocol (UDP);

attaching, if the packet is in IPv4 and not in either of TCP or UDP, a pseudo-header to the packet; and

computing by the HEA, if the packet is in IPv4 and not in either of TCP or UDP, the checksum of the packet based on the pseudo-header and the IPv4 standard.

2. The method of claim 1, determining whether the packet is in IPv4 further comprising:

parsing the IP header in order to determine the protocol.

3. The method of claim 1, the packet further having a cyclic redundancy check (CRC), computing by the HEA, if the packet is not in IPv4 further comprising:

computing the checksum of layer three to the beginning of the CRC.

4. The method of claim 1, further comprising:

parsing the packet for a source address and a destination address; and

building the pseudo-header with the source address and the destination address.

5. The method of claim 4, the packet having an IP header, further comprising:

giving the pseudo-header a length of the product of the IP header length field in the IPv4 Header with the number four, subtracted from the “

Total Length”

field in the IP header.

6. The method of claim 1, computing by the HEA, if the packet is not in IPv4 further comprising:

computing by the HEA, if the packet is not in IPv4, the checksum of the packet over a layer-2 payload;

7. The method of claim 1, determining, if the packet is in IPv4 further comprising:

determining, if the packet is in IPv4, whether a layer-3 payload of the packet is in transmission control protocol (TCP) or user datagram protocol (UDP).

8. A computer readable medium containing programming instructions for computing a blind checksum in a host Ethernet adapter (HEA), the programming instructions comprising:

receiving a packet in the HEA;

determining whether the packet is in Internet protocol version four (IPv4);

computing by the HEA, if the packet is not in IPv4, the checksum of the packet;

determining, if the packet is in IPv4, whether the packet is in transmission control protocol (TCP) or user datagram protocol (UDP);

attaching, if the packet is in IPv4 and not in either of TCP or UDP, a pseudo-header to the packet; and

computing by the HEA, if the packet is in IPv4 and not in either of TCP or UDP, the checksum of the packet based on the pseudo-header and the IPv4 standard.

9. The computer readable medium of claim 8, determining whether the packet is in IPv4 further comprising:

parsing the packet in order to determine the protocol.

10. The computer readable medium of claim 8, the packet further having a cyclic redundancy check (CRC), computing by the HEA, if the packet is not in IPv4 further comprising:

computing the checksum of the packet at layer three to the beginning of the CRC.

11. The computer readable medium of claim 8, the programming instructions further comprising:

parsing the packet for a source address and a destination address; and

building the pseudo-header with the source address and the destination address.

12. The computer readable medium of claim 11, the packet having an IP header, the programming instructions further comprising:

giving the pseudo-header a length of the product of the IP header length field in the IPv4 Header with the number four, subtracted from the “

Total Length”

field in the IP header.

13. The computer readable medium of claim 8, computing by the HEA, if the packet is not in IPv4 further comprising:

computing by the HEA, if the packet is not in IPv4, the checksum of the packet over a layer-2 payload;

14. The computer readable medium of claim 8, determining, if the packet is in IPv4 further comprising:

determining, if the packet is in IPv4, whether a layer-3 payload of the packet is in transmission control protocol (TCP) or user datagram protocol (UDP).

15. A host Ethernet adapter (HEA) for computing a blind checksum comprising:

a system for receiving a packet, determining whether the packet is in Internet protocol version four (IPv4), computing, if the packet is not in IPv4, the checksum of the packet, determining, if the packet is in IPv4, whether the packet is in transmission control protocol (TCP) or user datagram protocol (UDP), attaching, if the packet is in IPv4 and not in either of TCP or UDP, a pseudo-header to the packet, and computing, if the packet is in IPv4 and not in either of TCP or UDP, the checksum of the packet based on the pseudo-header and the IPv4 standard.

16. The HEA of claim 15, the system further for parsing the packet in order to determine the protocol.

17. The HEA of claim 15, the packet further having a cyclic redundancy check (CRC), the system further for computing the checksum of the packet at layer three to the beginning of the CRC.

18. The HEA of claim 15, the system further for parsing the packet for a source address and a destination address, and for building the pseudo-header with the source address and the destination address.

19. The HEA of claim 18, the packet having an IP header, the system further for giving the pseudo-header a length of the product of the IP header length field in the IPv4 Header with the number four, subtracted from the “

Total Length”

field in the IP header.

20. The HEA of claim 15, the system further for computing by the HEA, if the packet is not in IPv4, the checksum of the packet over a layer-2 payload;

21. The HEA of claim 15, the system further for determining, if the packet is in IPv4, whether a layer-3 payload of the packet is in transmission control protocol (TCP) or user datagram protocol (UDP).