35 research outputs found

    A Machine-Independent port of the MPD language run time system to NetBSD

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    SR (synchronizing resources) is a PASCAL - style language enhanced with constructs for concurrent programming developed at the University of Arizona in the late 1980s. MPD (presented in Gregory Andrews' book about Foundations of Multithreaded, Parallel, and Distributed Programming) is its successor, providing the same language primitives with a different, more C-style, syntax. The run-time system (in theory, identical, but not designed for sharing) of those languages provides the illusion of a multiprocessor machine on a single Unix-like system or a (local area) network of Unix-like machines. Chair V of the Computer Science Department of the University of Bonn is operating a laboratory for a practical course in parallel programming consisting of computing nodes running NetBSD/arm, normally used via PVM, MPI etc. We are considering to offer SR and MPD for this, too. As the original language distributions were only targeted at a few commercial Unix systems, some porting effort is needed. However, some of the porting effort of our earlier SR port should be reusable. The integrated POSIX threads support of NetBSD-2.0 and later allows us to use library primitives provided for NetBSD's phtread system to implement the primitives needed by the SR run-time system, thus implementing 13 target CPUs at once and automatically making use of SMP on VAX, Alpha, PowerPC, Sparc, 32-bit Intel and 64 bit AMD CPUs. We'll present some methods used for the impementation and compare some performance values to the traditional implementation.Comment: 6 page

    LibrettOS: A Dynamically Adaptable Multiserver-Library OS

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    We present LibrettOS, an OS design that fuses two paradigms to simultaneously address issues of isolation, performance, compatibility, failure recoverability, and run-time upgrades. LibrettOS acts as a microkernel OS that runs servers in an isolated manner. LibrettOS can also act as a library OS when, for better performance, selected applications are granted exclusive access to virtual hardware resources such as storage and networking. Furthermore, applications can switch between the two OS modes with no interruption at run-time. LibrettOS has a uniquely distinguishing advantage in that, the two paradigms seamlessly coexist in the same OS, enabling users to simultaneously exploit their respective strengths (i.e., greater isolation, high performance). Systems code, such as device drivers, network stacks, and file systems remain identical in the two modes, enabling dynamic mode switching and reducing development and maintenance costs. To illustrate these design principles, we implemented a prototype of LibrettOS using rump kernels, allowing us to reuse existent, hardened NetBSD device drivers and a large ecosystem of POSIX/BSD-compatible applications. We use hardware (VM) virtualization to strongly isolate different rump kernel instances from each other. Because the original rumprun unikernel targeted a much simpler model for uniprocessor systems, we redesigned it to support multicore systems. Unlike kernel-bypass libraries such as DPDK, applications need not be modified to benefit from direct hardware access. LibrettOS also supports indirect access through a network server that we have developed. Applications remain uninterrupted even when network components fail or need to be upgraded. Finally, to efficiently use hardware resources, applications can dynamically switch between the indirect and direct modes based on their I/O load at run-time. [full abstract is in the paper]Comment: 16th ACM SIGPLAN/SIGOPS International Conference on Virtual Execution Environments (VEE '20), March 17, 2020, Lausanne, Switzerlan

    The development of a node for a hardware reconfigurable parallel processor

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    This dissertation concerns the design and implementation of a node for a hardware reconfigurable parallel processor. The hardware that was developed allows for the further development of a parallel processor with configurable hardware acceleration. Each node in the system has a standard microprocessor and reconfigurable logic device and has high speed communications channels for inter-node communication. The design of the node provided high-speed serial communications channels allowing the implementation of various network topographies. The node also provided a PCI master interface to provide an external interface and communicate with local nodes on the bus. A high speed RlSC processor provided communication and system control functions and the reconfigurable logic device provided communication interfaces and data processing functions. The node was designed and implemented as a PCI card that interfaced a standard PCI bus. VHDL designs for logic devices that provided system support were developed, VHDL designs for the reconfigurable logic FPGA and software including drivers and system software were written for the node. The 64-bit version Linux operating system was then ported to the processor providing a UNIX environment for the system. The node functioned as specified and parallel and hardware accelerated processing was demonstrated. The hardware acceleration was shown to provide substantial performance benefits for the system

    Virtualization to build large scale networks

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    Abstract. There is not much research concerning network virtualization, even though virtualization has been a hot topic for some time and networks keep growing. Physical routers can be expensive and laborious to setup and manage, not to mention immobile. Network virtualization can be utilized in many ways, such as reducing costs, increasing agility and increasing deployment speed. Virtual routers are easy to create, copy and move. This study will research into the subjects of networks, virtualization solutions and network virtualization. Furthermore, it will show how to build a virtual network consisting of hundreds of nodes, all performing network routing. In addition, the virtual network can be connected to physical routers in the real world to provide benefits, such as performance testing or large-scale deployment. All this will be achieved using only commodity hardware

    Design and Performance of Scalable High-Performance Programmable Routers - Doctoral Dissertation, August 2002

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    The flexibility to adapt to new services and protocols without changes in the underlying hardware is and will increasingly be a key requirement for advanced networks. Introducing a processing component into the data path of routers and implementing packet processing in software provides this ability. In such a programmable router, a powerful processing infrastructure is necessary to achieve to level of performance that is comparable to custom silicon-based routers and to demonstrate the feasibility of this approach. This work aims at the general design of such programmable routers and, specifically, at the design and performance analysis of the processing subsystem. The necessity of programmable routers is motivated, and a router design is proposed. Based on the design, a general performance model is developed and quantitatively evaluated using a new network processor benchmark. Operational challenges, like scheduling of packets to processing engines, are addressed, and novel algorithms are presented. The results of this work give qualitative and quantitative insights into this new domain that combines issues from networking, computer architecture, and system design

    Development of an Android App to control and manage Cognitive Networks

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    As the interest in Mobile Ad Hoc networks is constantly growing for tactical, disaster-response situation, academic research and civilian contexts, some new protocol must be implemented to let those network scale. Cognitive networking may solve the problem thanks to its network-wide performances goal. The goal of this project is to develop a working testbed that will be exploited in the study and the analysis of cognitive networking mechanism and algorithms. This tool is developed in Androidope

    Understanding retargeting compilation techniques for network processors

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    Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

    Web attack risk awareness with lessons learned from high interaction honeypots

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    Tese de mestrado, Segurança Informática, Universidade de Lisboa, Faculdade de Ciências, 2009Com a evolução da web 2.0, a maioria das empresas elabora negócios através da Internet usando aplicações web. Estas aplicações detêm dados importantes com requisitos cruciais como confidencialidade, integridade e disponibilidade. A perda destas propriedades influencia directamente o negócio colocando-o em risco. A percepção de risco providencia o necessário conhecimento de modo a agir para a sua mitigação. Nesta tese foi concretizada uma colecção de honeypots web de alta interacção utilizando diversas aplicações e sistemas operativos para analisar o comportamento do atacante. A utilização de ambientes de virtualização assim como ferramentas de monitorização de honeypots amplamente utilizadas providencia a informação forense necessária para ajudar a comunidade de investigação no estudo do modus operandi do atacante, armazenando os últimos exploits e ferramentas maliciosas, e a desenvolver as necessárias medidas de protecção que lidam com a maioria das técnicas de ataque. Utilizando a informação detalhada de ataque obtida com os honeypots web, o comportamento do atacante é classificado entre diferentes perfis de ataque para poderem ser analisadas as medidas de mitigação de risco que lidam com as perdas de negócio. Diferentes frameworks de segurança são analisadas para avaliar os benefícios que os conceitos básicos de segurança dos honeypots podem trazer na resposta aos requisitos de cada uma e a consequente mitigação de risco.With the evolution of web 2.0, the majority of enterprises deploy their business over the Internet using web applications. These applications carry important data with crucial requirements such as confidentiality, integrity and availability. The loss of those properties influences directly the business putting it at risk. Risk awareness provides the necessary know-how on how to act to achieve its mitigation. In this thesis a collection of high interaction web honeypots is deployed using multiple applications and diverse operating systems in order to analyse the attacker behaviour. The use of virtualization environments along with widely used honeypot monitoring tools provide the necessary forensic information that helps the research community to study the modus operandi of the attacker gathering the latest exploits and malicious tools and to develop adequate safeguards that deal with the majority of attacking techniques. Using the detailed attacking information gathered with the web honeypots, the attacking behaviour will be classified across different attacking profiles to analyse the necessary risk mitigation safeguards to deal with business losses. Different security frameworks commonly used by enterprises are analysed to evaluate the benefits of the honeypots security concepts in responding to each framework’s requirements and consequently mitigating the risk
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