Patent ID: 8272055
Filing Date: 2012-09-18
Classification: H04L

Abstract:
1. A method performed in a processor of an intrusion detection/prevention system (IDS/IPS), for checking for valid packets in a server message block (SMB) named pipe in a communication network, comprising: receiving, in a processor configured as an IDS/IPS, a packet in a transmission and determining a kind of application of a target of the packet in response to receiving the packet; including, in the IDS/IPS, data in the packet as part of the SMB named pipe data inspected by the IDS/IPS as part of the SMB named pipe on only one of a condition that: receiving, in the processor configured as an IDS/IPS, a fragment/segment, and determining a kind of application of a target of the fragment/segment in response to receiving the fragment/segment; separating, in the IDS/IPS, fragments/segments with a same multiplex ID (MID) as part of a same SMB transaction command from fragments/segments with a different MID, the MID being in the SMB frame header, all for fragments/segments in the same SMB named pipe, when a reassembly table indicates that the kind of application of the target separates based on MID; processing, in the IDS/IPS, the same SMB transaction command with the same MID as being in a separate SMB transaction command instead of with the fragments/segments with the different MID when the kind of application of the target separates based on MID; receiving, in the processor configured as an IDS/IPS, plural request fragments belonging to a single distributed computing environment/remote procedure call (DCE/RPC) request; determining, in the IDS/IPS, the kind of application of a target of the DCE/RPC request; selecting, in the IDS/IPS, one of the request fragments as a source of a context ID depending on the target kind of application as indicated in a reassembly table; selecting, in the IDS/IPS, one of the request fragments as a source of an operation number as indicated in a reassembly table depending on the target kind of application; reassembling, in the IDS/IPS, the plural request fragments into a reassembled request; and inserting, in the IDS/IPS, the context ID from the selected request fragment into the context ID of a DCE/RPC header of the reassembled request; and inserting, in the IDS/IPS, the operation number from a DCE/RPC header of the selected request fragment into the operation number of a DCE/RPC header of the reassembled request.