Secure synthesis and activation of protocol translation agents

Protocol heterogeneity is pervasive and is a major obstacle to effective integration of services in large systems. However, standardization is not a complete answer. Standardized protocols must be general to prevent a proliferation of standards, and can therefore become complex and inefficient. Specialized protocols can be simple and efficient, since they can ignore situations that are precluded by application characteristics. One solution is to maintain agents for translating between protocols. However, n protocol types would require agents, since an agent must exist for a source - destination pair. A better solution is to create agents as needed. This paper examines the issues in the creation and management of protocol translation agents. We focus on the design of Nestor, an environment for synthesizing and managing RPC protocol translation agents. We provide rationale for the translation mechanism and the synthesis environment, with specific emphasis on the security issues arising in Nestor. Nestor has been implemented and manages heterogeneous RPC agents generated using the Cicero protocol construction language and the URPC toolkit.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49229/2/ds7402.pd

Pharmacology of MDMA- and Amphetamine-Like New Psychoactive Substances

New psychoactive substances (NPS) with amphetamine-, aminoindan-, and benzofuran basic chemical structures have recently emerged for recreational drug use. Detailed information about their psychotropic effects and health risks is often limited. At the same time, it emerged that the pharmacological profiles of these NPS resemble those of amphetamine or 3,4-methylenedioxymethamphetamine (MDMA). Amphetamine-like NPS induce psychostimulation and euphoria mediated predominantly by norepinephrine (NE) and dopamine (DA) transporter (NET and DAT) inhibition and transporter-mediated release of NE and DA, thus showing a more catecholamine-selective profile. MDMA-like NPS frequently induce well-being, empathy, and prosocial effects and have only moderate psychostimulant properties. These MDMA-like substances primarily act by inhibiting the serotonin (5-HT) transporter (SERT) and NET, also inducing 5-HT and NE release. Monoamine receptor interactions vary considerably among amphetamine- and MDMA-like NPS. Clinically, amphetamine- and MDMA-like NPS can induce sympathomimetic toxicity. The aim of this chapter is to review the state of knowledge regarding these substances with a focus on the description of the in vitro pharmacology of selected amphetamine- and MDMA-like NPS. In addition, it is aimed to provide links between pharmacological profiles and in vivo effects and toxicity, which leads to the conclusion that abuse liability for amphetamine-like NPS may be higher than for MDMA-like NPS, but that the risk for developing the life-threatening serotonin syndrome may be increased for MDMA-like NPS

Lightweight Thread Tunnelling in Network Applications

Active Network nodes are increasingly being used for nontrivial processing of data streams. These complex network applications typically benefit from protection between their components for faulttolerance or security. However, fine-grained memory protection introduces bottlenecks in communication among components. This paper describes memory protection in Expert, an OS for programmable network elements which re-examines thread tunnelling as a way of allowing these complex applications to be split over multiple protection domains. We argue that previous problems with tunnelling are symptoms of overly general designs, and we demonstrate a minimal domain-crossing primitive which nevertheless achieves the majority of benefits possible from tunnelling

Efficient Packet Demultiplexing for Multiple Endpoints and Large Messages

This paper describes a new packet filter mechanism that efficiently dispatches incoming network packets to one of multiple endpoints, for example address spaces. Earlier packet filter systems iteratively applied each installed filter against every incoming packet, resulting in high processing overhead whenever multiple filters existed. Our new packet filter provides an associative match function that enables similar but not identical filters to be combined together into a single filter. The filter mechanism, which we call the Mach Packet Filter (MPF), has been implemented for the Mach 3.0 operating system and is being used to support endpoint-based protocol processing, whereby each address space implements its own suite of network protocols. With large numbers of registered endpoints, MPF outperforms the earlier BSD Packet Filter (BPF) by over a factor of four. MPF also allows a filter program to dispatch fragmented packets, which was quite difficult with previous filter mechanisms

Language Support for Connector Abstractions

Software connectors are increasingly recognized as an important consideration in the design and implementation of object-oriented software systems. Connectors can be used to communicate across a distributed system, coordinate the activities of several objects, or adapt one object's interface to the interface of another. Mainstream object-oriented languages, however, do not provide explicit support for connectors. As a result, connection code is intermingled with application code, making it difficult to understand, evolve, and reuse connection mechanisms