Packet processing with re-insertion into network interface circuitry

• US 7,620,070 B1
• Filed: 06/24/2003
• Issued: 11/17/2009
• Est. Priority Date: 06/24/2003
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: Sidenblad, Paul J., Nanda, Sameer, Maufer, Thomas A., Gyugyi, Paul J.
• Primary Examiner(s): Moore, Jr.; Michael J
• Application Number:
  US10/603,792
• Time in Patent Office: 2,338 Days
• Field of Search: 714/712, 370/412
• US Class Current: 370/474
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9026 Single buffer per packet
• CPC Class Codes: H04L 49/9094 Arrangements for simultaneous transmit and receive, e.g. simultaneous reading/writing from/to the storage element

Abstract

Method and apparatus for packet processing by re-insertion into network interface circuitry. A method for handling a burst of packets sent to network interface circuitry includes checking for a connection table entry for received packets, and responsive to non-existence of the connection table entry for the received packets, sending the packets to network interface software for processing. The network interface software processing includes: building the connection table entry; processing the packets; and sending the packets as processed to the network interface circuitry. Additionally, a method for re-inserting a packet responsive to an active audit mode is described.

Claims

1. A method for assembling a plurality of packet fragments into a packet for transmission by network interface circuitry, the method comprising:

determining at the network interface circuitry that received data is a first packet fragment associated with a first packet;

storing the first packet fragment in a reserved buffer space in memory corresponding to the first packet, wherein the reserved buffer space stores one or more different packet fragments associated with the first packet;

determining that the first packet fragment is valid by matching a first checksum included in the first packet fragment with a second checksum included in a second packet fragment stored in the reserved buffer space;

sorting the one or more different packet fragments stored in the reserved buffer space based on a fragment number associated with each packet fragment;

determining, at a predetermined time interval, that the one or more different packet fragments associated with the first packet stored in the reserved buffer space constitute all packet fragments associated with the first packet;

combining the one or more different packet fragments associated with the first packet stored in the reserved buffer space to generate the first packet; and

transmitting the first packet from the network interface circuitry over a network to a receiver.

2. The method, according to claim 1, further comprising the steps of:

storing the first packet in a buffer accessible by the network interface circuitry;

incrementing a counter of the network interface circuitry;

determining that a connection table entry associated with the first packet does not exist in the connection table;

transmitting the first packet to network interface software for preparing the first packet for the network interface circuitry;

clearing the first packet from the buffer; and

decrementing the counter.

3. The method, according to claim 2, wherein the first packet is a Voice Over Internet Protocol formatted packet or a User Datagram Protocol formatted packet.

4. The method, according to claim 2, further comprising the step of generating a total count signal from the buffer, wherein the total count signal indicates to the network interface circuitry whether all the packets sent to the network interface software for processing have been at least partially processed.

5. The method, according to claim 2, wherein preparing the first packet for the network interface circuitry includes the steps of:

generating an address resolution table (ART) index for an address resolution table entry based on information stored in the first packet, wherein the address resolution table entry stores a media access control (MAC) address and MAC layer attributes associated with the first packet;

building the connection table entry that stores the ART index;

processing, at least in part, the first packet; and

transmitting the first packet to the network interface circuitry.

6. The method, according to claim 5, further comprising the step of setting a do not use flag for the connection table entry, wherein the packets subsequent to the first packet are transmitted to the network interface software for processing responsive to the do not use flag.

7. The method, according to claim 5, wherein the first packet is completely processed by the network interface software.

8. The method, according to claim 5, further comprising the step of completing the processing of the first packet with the network interface circuitry.

9. A computer readable medium storing instructions for causing a network interface to assemble a plurality of packet fragments into a packet for transmission by a network interface, by performing the steps of:

determining at the network interface that received data is a first packet fragment associated with a first packet;

storing the first packet fragment in a reserved buffer space in memory corresponding to the first packet, wherein the reserved buffer space stores one or more different packet fragments associated with the first packet;

determining that the first packet fragment is valid by matching a first checksum included in the first packet fragment with a second checksum included in one of the one or more different packet fragments;

sorting the one or more different packet fragments stored in the reserved buffer space based on a fragment number associated with each of the packet fragments;

determining, at a predetermined time interval, that the one or more different packet fragments associated with the first packet stored in the reserved buffer space constitute all packet fragments associated with the first packet;

combining the one or more different packet fragments associated with the first packet stored in the reserved buffer space to generate the first packet; and

transmitting the first packet from the network interface over a network to a receiver.

10. The computer readable medium, according to claim 9, wherein no packet fragments are missing at the end of the time period, and further comprising the steps of:

storing the first packet in a buffer accessible by the network interface circuitry;

incrementing a counter of the network interface circuitry;

determining that an entry associated with the first packet does not exist in the connection table;

transmitting the first packet to network interface software for preparing the first packet for the network interface circuitry;

clearing the first packet from the buffer; and

decrementing the counter.

11. The computer readable medium, according to claim 10, further comprising the step of generating a total count signal from the buffer, wherein the total count signal indicates to the network interface circuitry whether all the packets sent to the network interface software for processing have been at least partially processed.

12. The computer readable medium, according to claim 10, wherein the first packet is a Voice Over Internet Protocol formatted packet or a User Datagram Protocol formatted packet.

13. The computer readable medium, according to claim 10, wherein preparing the first packet for the network interface circuitry includes the steps of:

generating an address resolution table (ART) index for an address resolution table entry based on information stored in the first packet, wherein the address resolution table entry stores a media access control (MAC) address and MAC layer attributes associated with the first packet;

building the connection table entry that stores the ART index;

processing, at least in part, the first packet; and

transmitting the first packet to the network interface circuitry.

14. The computer readable medium, according to claim 13, further comprising the step of setting a do not use flag for the connection table entry, wherein the packets obtained after creation of the connection table entry are sent to the network interface software responsive to the do not use flag being set.

15. The computer readable medium, according to claim 13, wherein the first packet is completely processed by the network interface software.

16. A system for assembling a plurality of packet fragments into a packet for transmission from a network interface, the system comprising:

a central processing unit;

a system memory coupled to the central processing unit; and

the network interface coupled to the system memory and the central processing unit, the network interface configured to;

determine at the network interface that received data is a first packet fragment associated with a first packet,

store the first packet fragment in a reserved buffer space in a network interface local memory corresponding to the first packet, wherein the reserved buffer space stores one or more different packet fragments associated with the first packet,

determine that the first packet fragment is valid by matching a first checksum included in the first packet fragment with a second checksum included in a second packet fragment stored in the reserved buffer space,

sort the one or more different packet fragments stored in the reserved buffer space based on a fragment number associated with each of the packet fragments,

determine, at a predetermined time interval, that the one or more different packet fragments associated with the first packet stored in the reserved buffer space constitute all packet fragments associated with the first packet,

combining the one or more different packet fragments associated with the first packet stored in the reserved buffer space to generate the first packet, and

transmit the first packet from the network interface over a network to a receiver.

17. The system, according to claim 16, wherein at least one packet fragment is missing at the end of the time period, and the network interface further configured to clear the reserved buffer space corresponding to the first packet.

18. The system, according to claim 16, wherein no packet fragments are missing at the end of the time period, and the network interface further configured to:

store the first packet in a buffer accessible by the network interface,

increment a counter of the network interface circuitry;

determine that an entry associated with the first packet does not exist in the connection table;

transmit the first packet to network interface software for preparing the first packet for the network interface;

clear the first packet from the buffer; and

decrement the counter.

19. The system, according to claim 18, wherein the network interface is further configured to generate a total count signal from the buffer, wherein the total count signal indicates to the network interface circuitry whether all the packets sent to the network interface software for processing have been at least partially processed.

20. The system, according to claim 18, wherein the network interface software is configured to:

generate an address resolution table (ART) index for an address resolution table entry based on information stored in the first packet, wherein the address resolution table entry stores a media access control (MAC) address and MAC layer attributes associated with the first packet;

build the connection table entry that stores the ART index;

process, at least in part, the first packet; and

transmit the first packet to the network interface circuitry.