This masters thesis deals with updating the Linux emulation layer (so called Linuxulator). The task was to update the layer to match the functionality of Linux 2.6. As a reference implementation, the Linux 2.6.16 kernel was chosen. The concept is loosely based on the NetBSD implementation. Most of the work was done in the summer of 2006 as a part of the Google Summer of Code students program. The focus was on bringing the NPTL (new posix thread library) support into the emulation layer, including TLS (thread local storage), futexes (fast user space mutexes), PID mangling, and some other minor things. Many small problems were identified and fixed in the process. My work was integrated into the main FreeBSD source repository and will be shipped in the upcoming 7.0R release. We, the emulation development team, are working toward making the Linux 2.6 emulation the default emulation layer in FreeBSD.

<p>Security in operating systems is a highly topical subject nowadays as the Internet keeps expanding. The larger the Internet gets the more systems, with valuable information, get connected, which could be subjects of attacks. An operating system needs to protect its information from these attacks. Many servers are using UNIX based operating systems and the security in these systems is a widely discussed topic.</p><p>This project is going to test and investigate the security in two of the most common UNIX distributions, both based on the Berkley Software Distribution (BSD). The selected systems are FreeBSD and OpenBSD. The Add-on called TrustedBSD/SEBSD for FreeBSD will also be a subject for this project. A comparison of the security features in the two systems was performed both theoretically and practically and this report reflects the results of these experiments and comparisons. A conclusion is that each system suits best in different environments with different needs. The selected distributions also have different level of security in specific areas. An introduction to security in operating systems on a general basis is provided before the actual comparison begins.</p>

Security in operating systems is a highly topical subject nowadays as the Internet keeps expanding. The larger the Internet gets the more systems, with valuable information, get connected, which could be subjects of attacks. An operating system needs to protect its information from these attacks. Many servers are using UNIX based operating systems and the security in these systems is a widely discussed topic. This project is going to test and investigate the security in two of the most common UNIX distributions, both based on the Berkley Software Distribution (BSD). The selected systems are FreeBSD and OpenBSD. The Add-on called TrustedBSD/SEBSD for FreeBSD will also be a subject for this project. A comparison of the security features in the two systems was performed both theoretically and practically and this report reflects the results of these experiments and comparisons. A conclusion is that each system suits best in different environments with different needs. The selected distributions also have different level of security in specific areas. An introduction to security in operating systems on a general basis is provided before the actual comparison begins.

Virtualization is used extensively by Enterprise IT architecture and cloud computing, it is used to provide customers a part of their hardware resources as a service. Container technology is the new generation of virtualization and provides performance benefits due to less overhead. Earlier research has compared different container technologies regarding their performance, including Docker which is the most popular container technology. Most of this research has been focusing on Linux based container technologies. Even though there is interest in knowing how other container technologies under different operating systems perform. In this study we explore the performance of Docker in contrast to the performance of a contending container technology named Jails. We present how well each container technology performs running one or multiple containers, in the areas of CPU, memory, read from disk, write to disk, network and startup time efficiency. The comparison was done using collected statistics from different benchmarking tools. Results from this study have shown that Docker is utilizing shared resources and has better stability compared to Jails. We also discuss what unexplored benefits Docker and Jails can have by implementing each other’s unique features. Future work could consist of writing to disk or reading from disk performance tests under one common filesystem, e.g., ZFS file system. / Virtualisering används i stor utsträckning av Enterprise IT-arkitektur och molntjänster, den används för att kunna erbjuda sina kunder en del av sina hårdvaruresurser som en tjänst. Containerteknologi är den nya generationen virtualisering och ger prestandafördelar på grund av mindre omkostnader. Tidigare forskning har jämfört olika containerteknologier angående deras prestanda, inklusive Docker, som är den mest populära containertekniken. Merparten av tidigare forskning har fokuserat på Linuxbaserade containerteknologier, även om det finns intresse för att veta hur andra containerteknologier under olika operativsystem fungerar. I denna studie undersöker vi Dockers prestanda jämfört med prestandan till containerteknologin med namnet Jails. Vi presenterar hur bra varje containerteknologi fungerar med att köra en eller flera containrar inom områdena CPU, minne, läsa från disk, skriva till disk, nätverkshastighet och starttid. Jämförelsen gjordes med insamlad statistik från olika referensverktyg. Resultat från denna studie har visat att Docker använder delade resurser på ett effektivare sätt och har bättre stabilitet jämfört med Jails. Vi diskuterar också vilka outforskade fördelar Docker och Jails kan ha genom att implementera varandras unika funktioner. Framtida arbete kan bestå av att skriva till disk eller läsa från diskprestanda under ett gemensamt filsystem, t.ex. ZFS-filsystem.

Com o recente desenvolvimento de tecnologias de redes de altas taxas de transmissão, tais como Asynchronous Transfer Mode (ATM), o problema da carência por largura de banda foi solucionado. A questão atual é a implementação de sistemas que suportem os protocolos ATM de forma nativa e integral. Atualmente tem-se utilizado aplicativos tradicionais baseados nos protocolos TCP(UDP)/IP no topo da pilha de protocolos ATM. Tal modelo traz redundâncias que implicam diretamente em aumento de overhead na comunicação. Muitos modelos têm sido desenvolvidos para levar de forma direta a aplicação os serviços ATM. O propósito deste trabalho foi comparar o desempenho de transmissões de dados utilizando os protocolos TCP(UDP)/IP sobre ATM com transmissões de dados no modo ATM nativo. Para tal, utilizamos a plataforma de pesquisa HARP do sistema operacional FreeBSD. Tal plataforma implementa o modelo Classical IP sobre ATM utilizando os serviços AAL5 e ainda fornece uma API para sockets ATM permitindo que uma aplicação tenha acesso direto a camada AALS. Testes de taxa de transmissão, perda de células, e atraso na rede, foram realizados com base na modificação de parâmetros relacionados à aplicação e sistema operacional, tais como tamanho da mensagem sendo transmitida e tamanho dos buffers de socket. / The solution for the lack of bandwidth was solved by the recent development of high speed networks technologies, such as Asynchronous Transfer Mode - ATM. The question now is the implementation of systems, which provide support for ATM protocols in an integral way. Nowadays, legacy network applications, based in TCP/IP protocols have been used on top of ATM protocol stack. Such approach generates redundances that have as consequence an increase in the communication overhead. Many models have been developed to provide ATM services directly to applications. The goal of this study was to evaluate the performance of data transfers comparing the TCP/IP protocols over ATM with the performance of data transfers in native ATM mode. The Host ATM Research Plataform (HARP) was utilized on the FreeBSD operating system. This plataform implements Classical IP over ATM, utilizing AAL5 services. Furthermore, it provides an API for ATM sockets, allowing that an application directly access the AAL5 services. Measurements of throughput and investigations about cell loss and delay were carried out altering parameters related to the application and operating system. The parameters adopted were message size and socket buffer sizes.

Com o recente desenvolvimento de tecnologias de redes de altas taxas de transmissão, tais como Asynchronous Transfer Mode (ATM), o problema da carência por largura de banda foi solucionado. A questão atual é a implementação de sistemas que suportem os protocolos ATM de forma nativa e integral. Atualmente tem-se utilizado aplicativos tradicionais baseados nos protocolos TCP(UDP)/IP no topo da pilha de protocolos ATM. Tal modelo traz redundâncias que implicam diretamente em aumento de overhead na comunicação. Muitos modelos têm sido desenvolvidos para levar de forma direta a aplicação os serviços ATM. O propósito deste trabalho foi comparar o desempenho de transmissões de dados utilizando os protocolos TCP(UDP)/IP sobre ATM com transmissões de dados no modo ATM nativo. Para tal, utilizamos a plataforma de pesquisa HARP do sistema operacional FreeBSD. Tal plataforma implementa o modelo Classical IP sobre ATM utilizando os serviços AAL5 e ainda fornece uma API para sockets ATM permitindo que uma aplicação tenha acesso direto a camada AALS. Testes de taxa de transmissão, perda de células, e atraso na rede, foram realizados com base na modificação de parâmetros relacionados à aplicação e sistema operacional, tais como tamanho da mensagem sendo transmitida e tamanho dos buffers de socket. / The solution for the lack of bandwidth was solved by the recent development of high speed networks technologies, such as Asynchronous Transfer Mode - ATM. The question now is the implementation of systems, which provide support for ATM protocols in an integral way. Nowadays, legacy network applications, based in TCP/IP protocols have been used on top of ATM protocol stack. Such approach generates redundances that have as consequence an increase in the communication overhead. Many models have been developed to provide ATM services directly to applications. The goal of this study was to evaluate the performance of data transfers comparing the TCP/IP protocols over ATM with the performance of data transfers in native ATM mode. The Host ATM Research Plataform (HARP) was utilized on the FreeBSD operating system. This plataform implements Classical IP over ATM, utilizing AAL5 services. Furthermore, it provides an API for ATM sockets, allowing that an application directly access the AAL5 services. Measurements of throughput and investigations about cell loss and delay were carried out altering parameters related to the application and operating system. The parameters adopted were message size and socket buffer sizes.

This master thesis discourses upon problems with automatic building and testing of network security solution AVG for Linux/FreeBSD on platforms GNU/Linux and FreeBSD. This work introduces AVG for Linux/FreeBSD and its usage.  Compilation and link are discussed from the source code to the distribution packages, which users can install on your computer. Also, the repository term was introduced, containing the information about their creation and usage. The part about AVG for Linux/FreeBSD testing discusses suitable  automatic testing proposals for this product and implementation of the best solutions. In the practical part, the testing tool was developed. AVG for Linux/FreeBSD was tested using the test tool and implemented test set.

Denna rapport innehåller en studie över ett operativsystems påverkan på lastbalanserarenHAproxy. Studien utfördes i en experimentmiljö med fyra virtuella testklienter, en lastbalanseraresamt tre webbservernoder kopplade till lastbalanseraren. Operativsystemet varhuvudpunkten i studien där belastningen på dess hårdvara, svarstiden, antalet anslutningarsamt det maximala antalet anslutninger per sekund undersöktes. De operativsystem somtestades var Ubuntu 10.04, CentOS 6.5, FreeBSD 9.1 och OpenBSD 5.5. Resultaten fråntesterna visar att hårdvaran och svarstiden är näst intill identisk på samtliga operativsystemmed undantag för OpenBSD där förutsättningarna för att genomföra hårdvarutesternainte kunde uppnås. FreeBSD var det operativsystem som klarade av att hantera flestantal anslutningar tillsammans med CentOS. Ubuntu visade sig vara mer begränsat ochOpenBSD var mycket begränsat. FreeBSD klarade även av högst antal anslutningar persekund, följt av Ubuntu, CentOS och slutligen OpenBSD som visade sig vara det sämstpresterande. / This report contains a study over an operating system’s impact on the load balancerHAproxy. The study was performed in an experimental environment with four virtualclients for testing, one load balancer and three web server nodes connected to the loadbalancer. The operating system was the main point in the study where the load on theload balancer’s hardware, the response time, the amount of connections and the maximumamount of connections per second were examined. The operating systems whichwere tested was Ubuntu 10.04, CentOS 6.5, FreeBSD 9.1 and OpenBSD 5.5. The resultsfrom the tests shows that the load on the hardware and the response time are almost identicalon all operating systems with the exception of OpenBSD where the conditions to beable to run the hardware tests could not be achieved. FreeBSD was the operating systemthat was able to manage the highest amount of connections along with CentOS. Ubuntuturned out to be more limited and OpenBSD was very limited. FreeBSD also managedthe highest amount of connections per second, followed by Ubuntu, CentOS and finallyOpenBSD which turned out to be the worst performer.

Digital forensics is the investigation and recovery of data from digital hardware. The field has grown in recent years to include support for operating systems such as Windows, Linux and Mac OS X. However, little to no support has been provided for less well known systems such as the FreeBSD operating system. The project presented in this paper focuses on creating the foundational support for FreeBSD via Volatility, a leading forensic tool in the digital forensic community. The kernel and source code for FreeBSD were studied to understand how to recover various data from analysis of a given system’s memory image. This paper will focus on the base Volatility support that was implemented, as well as the additional plugins created to recover desired data, including but not limited to the retrieval of a system’s process list and mounted file systems.

<p>The Transmission Control Protocol (TCP) has been the dominant transport protocol in the Internet for many years. One of the reasons to this is that TCP employs congestion control mechanisms which prevent the Internet from being overloaded. Although TCP's congestion control has evolved during almost twenty years, the area is still an active research area since the environments where TCP are employed keep on changing. One of the congestion control mechanisms that TCP uses is fast retransmit, which allows for fast retransmission of data that has been lost in the network. Although this mechanism provides the most effective way of retransmitting lost data, it can not always be employed by TCP due to restrictions in the TCP specification.</p><p>The primary goal of this work was to investigate when fast retransmit inhibitions occur, and how much they affect the performance of a TCP flow. In order to achieve this goal a large series of practical experiments were conducted on a real TCP implementation.</p><p>The result showed that fast retransmit inhibitions existed, in the end of TCP flows, and that the increase in total transmission time could be as much as 301% when a loss were introduced at a fast retransmit inhibited position in the flow. Even though this increase was large for all of the experiments, ranging from 16-301%, the average performance loss, due to an arbitrary placed loss, was not that severe. Because fast retransmit was inhibited in fewer positions of a TCP flow than it was employed, the average increase of the transmission time due to these inhibitions was relatively small, ranging from 0,3-20,4%.</p>