Abstract: Method and apparatus for reassembling a packet from fragments. The fragments of the packet are obtained by a device, such as a firewalling device. The fragments are sorted according to the packet and order of the fragments. The fragments are stored in association with the packet and in order. Once all the fragments to reconstitute the packet have been collected, the fragments are assembled in order to reconstitute the packet.

Abstract: Method and apparatus for routing and bridging are described. An address from a packet is obtained and used to find an index in a table. If the address is found in the table, the index stored in association with the address obtained. The index is stored in a data structure associated with the packet.

Abstract: A method and apparatus for filtering a packet on a connection within a computing system. In one embodiment, the method includes: receiving the packet; delegating the packet to an offload unit for filtering the packet; and determining, by the offload unit, whether the connection is a delegated connection.

Abstract: A method of setting up a delegated connection for processing by an offload unit is described. The method comprises establishing a TCP connection and determining whether or not to delegate the TCP connection for processing by the offload unit, producing a delegated connection, and setting up the delegated connection by creating a delegated connection table entry. When frames are received on the delegated connection by the offload unit, the offload unit determines if user buffers are available. When user buffers are available, the offload unit uploads payload data to the user buffers. When user buffers are not available, the offload unit uploads a portion of the payload data to a buffer allocated in Operating System memory space.

Abstract: A method and apparatus for processing data received and transmitted on a TCP connection is described. An offload unit processes received data for which a special case does not exist, to produce payload data, which is uploaded directly to application memory. The offload unit partially processes received data for which a special case does exist and uploads the partially processed received data to a buffer stored in system memory. The partially processed received data is then further processed by a TCP stack to produce payload data, which is copied to application memory.

Abstract: A method and apparatus for editing outbound frames and generating acknowledgements for a TCP connection is described. Acknowledgements are automatically generated and included in outbound frames during data transmissions with minimal processor intervention.

Abstract: A method and apparatus for storing and accessing connection information is described. A delegated connection table stores an entry for each connection delegated by a TCP stack for processing by an offload unit. A portion of the delegated connection table storing receive buffer information is accessed by the TCP stack without disrupting receive or transmit traffic. The offload unit offloads some TCP processing from a host processor and processes data received on connections not stored in the delegated connection table while accepting incoming data.

Abstract: A system and methods of uploading payload data to user buffers in system memory and of uploading partially processed frame data to legacy buffers allocated in Operating System memory space are described. User buffers are stored in a portion of system memory allocated to an application program, therefore data stored in user buffers does not need to be copied from another portion of system memory to the portion of system memory allocated to the application program. When partially processed frame data is uploaded by hardware to a legacy buffer in system memory, a tag, uniquely identifying the legacy buffer location is transferred by the hardware to a TCP stack, enabling the TCP stack to locate the legacy buffer.

Abstract: A method and apparatus for transmitting commands between a TCP stack and an offload unit and for communicating receive and transmit data buffer locations is described. A command ring buffer stored in system memory is used to transmit commands from the TCP stack to the offload unit and to transmit command status from the offload unit to the TCP stack. A notification ring buffer is used to transmit connection information from the offload unit to the TCP stack. Other ring buffers are used to transmit locations of transmit buffers or receive buffers stored in system memory from the TCP stack to the offload unit.