HASHING TECHNIQUES FOR USE IN A NETWORK ENVIRONMENT

摘要

Some embodiments provide a physical forwarding element that hashes portions of packet headers using several novel hashing techniques. The techniques include a novel set of finishing operations that improve the quality of resulting hashes by increasing their distribution and improving their apparent-randomness. In addition, the finishing operations virtually guarantee that different length inputs will hash to different results, even when padded to be the same initial values. The techniques also include efficient handling of remainder sections when distributing sections of a hash input across multiple processing units. The remainders are hashed into various previously generated hashes based on how many remainders result. These hashing techniques are useful for many network applications.

主权项

1. A non-transitory machine readable medium storing a program that, when executed by at least one processing unit, generates a hash to process a packet, the program comprising sets of instructions for:
dividing at least a portion of a packet's header into a plurality of chunks, including a set of chunks that are of equal size; hashing the set of chunks to generate a set of hashes; for each remaining chunk, hashing each remaining chunk into one of the generated hashes in the set of hashes; merging the set of hashes with one another to produce a final hash for the portion of the header; and processing the packet based on the final hash.