Method and apparatus for data re-assembly with a high performance network interface

Abstract

A system and method are provided for transferring a packet received from a network to a host computer according to an operation code associated with the packet. A packet received at a network interface is parsed to retrieve information from a header portion of the packet. A flow key is generated for a received packet that was formatted with one of a set of predetermined protocols. A packet's flow key identifies a communication flow that comprises the packet. Based on some of the retrieved information, a code is associated with the packet to inform a transfer engine how the packet should be transferred to host memory. Based on a packet's code, the transfer engine stores the packet in one or more host memory buffers. If the packet was formatted with one of the set of predetermined protocols, its data is re-assembled in a re-assembly buffer with data from other packets in the same communication flow. Re-assembled data may be provided to a destination application or user through page flipping. If the packet is being re-assembled, a header portion of the packet is stored in a separate header buffer. If the packet is not being re-assembled, it is stored in its entirety in the header buffer if it is smaller than a predetermined threshold. If a non-re-assembled packet is larger than the threshold for the header buffer, it is stored in another type of buffer for larger non-re-assembled packets. After a packet is stored in a buffer, the transfer engine informs the host computer of the packet by configuring a descriptor with information on the packet and releasing the descriptor to the host computer.