System and Method for Providing Transformation of Multi-Protocol Packets in a Data Stream

Abstract

A system and method for facilitating packet transformation of multi-protocol, multi-flow, streaming data. Packet portions subject to change are temporarily stored, and acted upon through processing of protocol-dependent instructions, resulting in a protocol-dependent modification of the temporarily stored packet information. Validity tags are associated with different segments of the temporarily-stored packet, where the state of each tag determines whether its corresponding packet segment will form part of the resulting modified packet. Only those packet segments identified as being part of the resulting modified packet are reassembled prior to dispatch of the packet.

1 . A system comprising:
 a programmable lookup word generator to receive a set of information and to produce a lookup word, the programmable lookup word generator including:   a profile memory configured to store a set of instructions for generating the lookup word; and   a selection mechanism for selecting portions of the set of information in response to the set of instructions retrieved from the profile memory, the selection mechanism including a matrix of storage elements and shift logic for use in generating the lookup word; and   a content-addressable memory, coupled to the programmable lookup word generator, configured to receive said generated lookup word and to perform a lookup operation based on said generated lookup word in order to generate one or more lookup result indications.   
     
     
         2 . The system of  claim 1 , further comprising a queue coupled to the matrix of storage elements and the content addressable memory. 
     
     
         3 . The system of  claim 1 , wherein the profile memory is responsive to a profile selection in retrieving the set of instructions used by the selection mechanism; and wherein the received set of information includes the profile selection. 
     
     
         4 . The system of  claim 3 , wherein the programmable lookup word generator includes a shift logic control unit responsive to the set of instruction for controlling said shift logic. 
     
     
         5 . A method for generating a lookup word, the method comprising:
 receiving a set of information including a profile identification;   retrieving a set of instructions from a profile memory based on the profile identification;   manipulating the set of information in response to the set of instructions to generate the lookup word, said manipulation including controlling a selection mechanism, the selection mechanism including a matrix of storage elements and shift logic for use in generating the lookup word; and   exporting the lookup word to a content-addressable memory for use by said content-addressable memory in performing a lookup operation to identify one or more content-addressable memory lookup results.   
     
     
         6 . The method of  claim 5 , further comprising programming the profile memory with the set of instructions. 
     
     
         7 . The method of  claim 5 , wherein the set of information includes information related to a packet, and said one or more content-addressable memory results include a packet classification. 
     
     
         8 . A system for generating a lookup word, the system comprising:
 means for receiving a set of information including a profile identification;   means for retrieving a set of instructions from a profile memory based on the profile identification;   means for manipulating the set of information in response to the set of instructions to generate the lookup word, said means for manipulating the set of information includes a matrix of storage elements and shift logic for use in generating the lookup word; and   means for exporting the generated lookup word to a content-addressable memory for use by said content-addressable memory in performing a lookup operation to identify one or more content-addressable memory lookup results.   
     
     
         9 . A packet editor module comprising:
 an input memory configured to store incoming packet header information of a packet;   a packet processing unit configured to generate packet header information for the packet by operating on the packet header information stored in the input memory, the packet processing unit including a first processing component configured to generate layer 2 (L2) packet header information for the packet and a second processing component implemented in parallel with the first processing component and configured to generate layer 3 (L3) packet header information for the packet; and   a build component configured to receive the generated packet header information while the input memory stores incoming packet header information for a next packet.