Parsing a packet header

摘要

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.

主权项

1. A method for use with a computer system, comprising:
receiving, with a network controller for a host computer, a packet that includes a header, the header indicating a first characteristic that is associated with a transport layer of a multiple layer protocol stack and a second characteristic that is associated with an application layer of the stack; parsing the packet with the network controller to extract said first and second characteristics, wherein said first characteristic includes an identification of a Transmission Control Protocol (TCP) connection, and said second characteristic includes a length of application data being received; and passing a handle from the network controller to the host computer to indicate said first and second characteristics, wherein the handle associates the packet with a flow that corresponds to the TCP connection, and indicates an amount of said application data to be stored in the host computer.