NETWORK GATEWAY MECHANISM HAVING A PROTOCOL STACK PROXY

A system for a network gateway that provides computer data security using a protocol stack proxy is disclosed. The system evaluates data that arrives at a computer system that is executing a network operating system. The system comprises a protocol stack proxy, coupled between a device driver on the computer system that is configured to receive the data from a network and deliver the data according to a first protocol associated with a first network layer, and one or more components of the network operating system that receive packets according to the first protocol. The protocol stack proxy has one or more protocol proxy layers configured to (A) receive the data from the device driver; (B) pass the data to a second network layer that is higher than the first network layer; (C) evaluate the data to determine whether the data satisfies a predetermined criteria; and (D) if the data satisfies the predetermined criteria, to (D1) pass the data to the first network layer, and (D2) transmit the data to the one or more components to the network operating system.