Patent ID: 7509673

Claim:
A firewall framework implemented within a computer system for providing multi-layering filtering of a packet, comprising: a set of layer processors, wherein each layer processor in the set is associated with a respective layer within a protocol stack, each layer processor being capable of processing layer parameters for the packet being processed by the layer processor and each layer processor being further capable of forming a requesting layer that receives a packet context from another layer processor, issues a classification request that includes the layer parameters, the packet and the packet context, and modifies the packet context by adding the layer parameters; and a first firewall engine of a kernel mode including: a layer interface for receiving the classification request from the requesting layer and for returning an action to the requesting layer, a set of installed filters, and a lookup component for identifying at least one matching filter from the set of installed filters and identifying from the matching filter the action to be returned by the layer interface; and a second firewall engine of a user mode including: a filter module for replicating filtering of the packet by the first firewall engine for at least one layer processor of the user mode and installing a new filter to the set of installed filters.