Method of forming a hash input from packet contents and an apparatus thereof

A method of implementing a parser engine, the method comprising:

• identifying one or more protocol layers of a packet, wherein each of the protocol layers have one or more fields;
• for each protocol layer of the protocol layers, expanding the protocol layer to a generic format based on the identification of the protocol layer thereby forming an expanded protocol layer;
• and
• selecting contents from each of the expanded protocol layers to apply a hash function, wherein the expanding of the protocol layer comprises:
• maintaining a bit vector for the expanded protocol layer, wherein the bit vector includes a bit for each byte of the expanded protocol layer such that each of the bits corresponds to one of the bytes of the expanded protocol layer;
• for each of the bits, setting the bit to a first value if the corresponding byte is a part of a valid field of the protocol layer, wherein each of the valid fields is a field existing in the protocol layer of the packet before the protocol layer has been expanded to the expanded protocol layer;
• and
• for each of the bits, setting the bit to a second value if the corresponding byte is a part of an invalid field of the protocol layer, wherein each of the invalid fields is a field that did not exist in the protocol layer of the packet before the protocol layer has been expanded to the expanded protocol layer.

A method of implementing network switch, the method comprising:

• receiving a packet having a packet header at an incoming port of the network switch, wherein the packet header includes one or more protocol headers;
• for each of the protocol headers, generalizing the protocol header to a generic format for a corresponding protocol thereby forming a generalized protocol header;
• for each generalized protocol header, extracting one or more fields from the generalized protocol header;
• for each generalized protocol header, concatenating the one or more extracted fields from the generalized protocol header to form a hash layer;
• and
• using a bit vector to determine which hash layers of all expanded protocol headers are to be selected to form a hash input.

A network switch comprising:

• an input port and an output port for receiving and transmitting packets having headers including one or more protocol layers;
• a memory for storing a set of software-defined mappings of generic protocol layer formats for one or more protocols and for storing sets of generic hash commands for extracting desired fields from the protocol layers that have been converted into one of the generic protocol layer formats, and for storing a table of bit vectors;
• and
• a parser engine for:
• performing a header generalization process on the header of each of the packets to generalize each of the protocol layers of the header of the packet according to one of the generic protocol layer formats thereby forming an expanded protocol layer:
• selecting one or more of a set of generic hash commands based on a layer type of the expanded protocol layer;
• and
• for selecting contents from the expanded protocol layers to apply to a hash function by applying the one or more of the set of generic hash commands to the expanded protocol layer.

A parser engine comprising a circuit configured to:

• identify one or more protocol layers of a packet, wherein each of the protocol layers have one or more fields;
• for each protocol layer of the protocol layers:
• expand the protocol layer to a generic format based on the identification of the protocol layer thereby forming an expanded protocol layer;
• selecting one or more of a set of generic hash commands based on a layer type of the expanded protocol layer;
• and
• select contents from the expanded protocol layer to apply to a hash function by applying the one or more of the set of generic hash commands to the expanded protocol layer.