Using Upstream MPTCP in Linux Systems
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Improving Route Scalability: Nexthops As Separate Objects
Improving Route Scalability: Nexthops as Separate Objects September 2019 David Ahern | Cumulus Networks !1 Agenda Executive Summary ▪ If you remember nothing else about this talk … Driving use case Review legacy route API Dive into Nexthop API Benefits of the new API Cumulus Networks !2 Performance with the Legacy Route API route route route prefix/lenroute prefix/lendev prefix/lendev gatewayprefix/len gatewaydev gatewaydev gateway Cumulus Networks !3 Splitting Next Hops from Routes Routes with separate Nexthop objects Legacy Route API route route prefix/len nexthop route nexthop id dev route gateway prefix/lenroute prefix/lendev prefix/lendev gatewayprefix/len gatewaydev gatewaydev gateway route prefix/len nexthop nexthop nexthop id group nexthopdev nexthop[N] gatewaydev gateway Cumulus Networks !4 Dramatically Improves Route Scalability … Cumulus Networks !5 … with the Potential for Constant Insert Times Cumulus Networks !6 Networking Operating System Using Linux APIs Routing daemon or utility manages switchd ip FRR entries in kernel FIBs via rtnetlink APIs SDK userspace ▪ Enables other control plane software to use Linux networking APIs rtnetlink Data path connections, stats, troubleshooting, … FIB notifications FIB Management of hardware offload is separate kernel upper devices tunnels ▪ Keeps hardware in sync with kernel ... eth0 swp1 swp2 swpN Userspace driver with SDK leveraging driver driver driver kernel notifications NIC switch ASIC H / W Cumulus Networks !7 NOS with switchdev Driver In-kernel switchdev driver ip FRR Leverages -
Mesalock Linux: Towards a Memory-Safe Linux Distribution
MesaLock Linux Towards a memory-safe Linux distribution Mingshen Sun MesaLock Linux Maintainer | Baidu X-Lab, USA Shanghai Jiao Tong University, 2018 whoami • Senior Security Research in Baidu X-Lab, Baidu USA • PhD, The Chinese University of Hong Kong • System security, mobile security, IoT security, and car hacking • MesaLock Linux, TaintART, Pass for iOS, etc. • mssun @ GitHub | https://mssun.me !2 MesaLock Linux • Why • What • How !3 Why • Memory corruption occurs in a computer program when the contents of a memory location are unintentionally modified; this is termed violating memory safety. • Memory safety is the state of being protected from various software bugs and security vulnerabilities when dealing with memory access, such as buffer overflows and dangling pointers. !4 Stack Buffer Overflow • https://youtu.be/T03idxny9jE !5 Types of memory errors • Access errors • Buffer overflow • Race condition • Use after free • Uninitialized variables • Memory leak • Double free !6 Memory-safety in user space • CVE-2017-13089 wget: Stack-based buffer overflow in HTTP protocol handling • A stack-based buffer overflow when processing chunked, encoded HTTP responses was found in wget. By tricking an unsuspecting user into connecting to a malicious HTTP server, an attacker could exploit this flaw to potentially execute arbitrary code. • https://bugzilla.redhat.com/show_bug.cgi?id=1505444 • POC: https://github.com/r1b/CVE-2017-13089 !7 What • Linux distribution • Memory-safe user space !8 Linux Distribution • A Linux distribution (often abbreviated as distro) is an operating system made from a software collection, which is based upon the Linux kernel and, often, a package management system. !9 Linux Distros • Server: CentOS, Federa, RedHat, Debian • Desktop: Ubuntu • Mobile: Android • Embedded: OpenWRT, Yocto • Hard-core: Arch Linux, Gentoo • Misc: ChromeOS, Alpine Linux !10 Security and Safety? • Gentoo Hardened: enables several risk-mitigating options in the toolchain, supports PaX, grSecurity, SELinux, TPE and more. -
Communicating Between the Kernel and User-Space in Linux Using Netlink Sockets
SOFTWARE—PRACTICE AND EXPERIENCE Softw. Pract. Exper. 2010; 00:1–7 Prepared using speauth.cls [Version: 2002/09/23 v2.2] Communicating between the kernel and user-space in Linux using Netlink sockets Pablo Neira Ayuso∗,∗1, Rafael M. Gasca1 and Laurent Lefevre2 1 QUIVIR Research Group, Departament of Computer Languages and Systems, University of Seville, Spain. 2 RESO/LIP team, INRIA, University of Lyon, France. SUMMARY When developing Linux kernel features, it is a good practise to expose the necessary details to user-space to enable extensibility. This allows the development of new features and sophisticated configurations from user-space. Commonly, software developers have to face the task of looking for a good way to communicate between kernel and user-space in Linux. This tutorial introduces you to Netlink sockets, a flexible and extensible messaging system that provides communication between kernel and user-space. In this tutorial, we provide fundamental guidelines for practitioners who wish to develop Netlink-based interfaces. key words: kernel interfaces, netlink, linux 1. INTRODUCTION Portable open-source operating systems like Linux [1] provide a good environment to develop applications for the real-world since they can be used in very different platforms: from very small embedded devices, like smartphones and PDAs, to standalone computers and large scale clusters. Moreover, the availability of the source code also allows its study and modification, this renders Linux useful for both the industry and the academia. The core of Linux, like many modern operating systems, follows a monolithic † design for performance reasons. The main bricks that compose the operating system are implemented ∗Correspondence to: Pablo Neira Ayuso, ETS Ingenieria Informatica, Department of Computer Languages and Systems. -
Linux Kernel and Driver Development Training Slides
Linux Kernel and Driver Development Training Linux Kernel and Driver Development Training © Copyright 2004-2021, Bootlin. Creative Commons BY-SA 3.0 license. Latest update: October 9, 2021. Document updates and sources: https://bootlin.com/doc/training/linux-kernel Corrections, suggestions, contributions and translations are welcome! embedded Linux and kernel engineering Send them to [email protected] - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 1/470 Rights to copy © Copyright 2004-2021, Bootlin License: Creative Commons Attribution - Share Alike 3.0 https://creativecommons.org/licenses/by-sa/3.0/legalcode You are free: I to copy, distribute, display, and perform the work I to make derivative works I to make commercial use of the work Under the following conditions: I Attribution. You must give the original author credit. I Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under a license identical to this one. I For any reuse or distribution, you must make clear to others the license terms of this work. I Any of these conditions can be waived if you get permission from the copyright holder. Your fair use and other rights are in no way affected by the above. Document sources: https://github.com/bootlin/training-materials/ - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 2/470 Hyperlinks in the document There are many hyperlinks in the document I Regular hyperlinks: https://kernel.org/ I Kernel documentation links: dev-tools/kasan I Links to kernel source files and directories: drivers/input/ include/linux/fb.h I Links to the declarations, definitions and instances of kernel symbols (functions, types, data, structures): platform_get_irq() GFP_KERNEL struct file_operations - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 3/470 Company at a glance I Engineering company created in 2004, named ”Free Electrons” until Feb. -
Adecuándose a La Norma ISO/IEC 1799 Mediante Software Libre
Adecu´andose a la norma ISO/IEC 1799 mediante software libre * Jose Fernando Carvajal Vi´on Grupo de Inter´esen Seguridad de ATI (ATI-GISI) <[email protected]> Javier Fern´andez-Sanguino Pe˜na Grupo de Inter´esen Seguridad de ATI (ATI-GISI) <[email protected]> 28 de octubre de 2002 Resumen Este art´ıculo muestra la forma de adecuar a la norma ISO/IEC 17999 un sistema de informaci´onimplementado en un servidor cuyo software de sistema operativo se basa en alguna alternativa de software Libre y c´odigo abierto. La utilizaci´onde una distribuci´onDebian GNU/Linux sirve como base a la que a˜nadir las utilidades y paquetes necesarios para conseguir el objetivo. ´Indice 1. Introducci´on 1 2. Objetivo y Asunciones 2 3. Cumplimiento de la Norma ISO/IEC 17799 en GNU/Linux 4 4. Conclusiones 4 5. Referencias 5 6. Referencias de herramientas 7 7. Referencias Generales 11 *Copyright (c) 2002 Jose Fernando Carvajal y Javier Fern´andez-Sanguino. Se otorga permiso para copiar, distribuir y/o modificar este documento bajo los t´erminos de la Licencia de Documen- taci´onLibre GNU, Versi´on1.1 o cualquier otra versi´onposterior publicada por la Free Software Foundation. Puede consultar una copia de la licencia en: http://www.gnu.org/copyleft/fdl.html 1 1. Introducci´on De forma general para mantener la seguridad de los activos de informaci´on se deben preservar las caracter´ısticas siguientes [1]. 1. Confidencialidad: s´oloel personal o equipos autorizados pueden acceder a la informaci´on. 2. Integridad: la informaci´on y sus m´etodos de proceso son exactos y completos. -
Linux Networking 101
The Gorilla ® Guide to… Linux Networking 101 Inside this Guide: • Discover how Linux continues its march toward world domination • Learn basic Linux administration tips • See how easy it can be to build your entire network on a Linux foundation • Find out how Cumulus Linux is your ticket to networking freedom David M. Davis ActualTech Media Helping You Navigate The Technology Jungle! In Partnership With www.actualtechmedia.com The Gorilla Guide To… Linux Networking 101 Author David M. Davis, ActualTech Media Editors Hilary Kirchner, Dream Write Creative, LLC Christina Guthrie, Guthrie Writing & Editorial, LLC Madison Emery, Cumulus Networks Layout and Design Scott D. Lowe, ActualTech Media Copyright © 2017 by ActualTech Media. All rights reserved. No portion of this book may be reproduced or used in any manner without the express written permission of the publisher except for the use of brief quotations. The information provided within this eBook is for general informational purposes only. While we try to keep the information up- to-date and correct, there are no representations or warranties, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the information, products, services, or related graphics contained in this book for any purpose. Any use of this information is at your own risk. ActualTech Media Okatie Village Ste 103-157 Bluffton, SC 29909 www.actualtechmedia.com Entering the Jungle Introduction: Six Reasons You Need to Learn Linux ....................................................... 7 1. Linux is the future ........................................................................ 9 2. Linux is on everything .................................................................. 9 3. Linux is adaptable ....................................................................... 10 4. Linux has a strong community and ecosystem ........................... 10 5. -
Linux 2.5 Kernel Developers Summit
conference reports This issue’s reports are on the Linux 2.5 Linux 2.5 Kernel Developers Linux development, but I certainly Kernel Developers Summit Summit thought that, in all of this time, someone would have brought this group together OUR THANKS TO THE SUMMARIZER: SAN JOSE, CALIFORNIA before. Rik Farrow, with thanks to La Monte MARCH 30-31, 2001 Yarroll and Chris Mason for sharing their Summarized by Rik Farrow Another difference appeared when the notes. first session started on Friday morning. The purpose of this workshop was to The conference room was set up with cir- provide a forum for discussion of cular tables, each with power strips for changes to be made in the 2.5 release of For additional information on the Linux laptops, and only a few attendees were Linux (a trademark of Linus Torvalds). I not using a laptop. USENIX had pro- 2.5 Kernel Developers Summit, see the assume that many people reading this vided Aeronet wireless setup via the following sites: will be familiar with Linux, and I will hotel’s T1 link, and people were busy <http://lwn.net/2001/features/KernelSummit/> attempt to explain things that might be typing and compiling. Chris Mason of unfamiliar to others. That said, the odd- <http://cgi.zdnet.com/slink?91362:12284618> OSDN noticed that Dave Miller had numbered releases, like 2.3 and now 2.5, <http://www.osdn.com/conferences/kernel/> written a utility to modulate the speed of are development releases where the the CPU fans based upon the tempera- intent is to try out new features or make ture reading from his motherboard. -
Linux Kernel 8.1 Introduction
Page 1 of 6 Linux Kernel 8.1 Introduction: The Linux kernel is a Unix-like operating system kernel used by a variety of operating systems based on it, which are usually in the form of Linux distributions. The Linux kernel is a prominent example of free and open source software. The Linux kernel is released under the GNU General Public License version 2 (GPLv2) (plus some firmware images with various non-free licenses), and is developed by contributors worldwide. Day-to-day development discussions take place on the Linux kernel mailing list. The Linux kernel was initially conceived and created in 1991 by Finnish computer science student Linus Torvalds. Linux rapidly accumulated developers and users who adapted code from other free software projects for use with the new operating system. The Linux kernel has received contributions from thousands of programmers. 8.2 History: History In April 1991, Linus Torvalds, a 21-year-old student at the University of Helsinki, Finland started working on some simple ideas for an operating system. He started with a task switcher in Intel 80386 assembly language and a terminal driver. On 25 August 1991, Torvalds posted the following to comp.os.minix, a newsgroup on Usenet: I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones. This has been brewing since April, and is starting to get ready. I'd like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of the file-system (due to practical reasons) among other things). -
Practical Practical
PRACTICAL PRACTICAL GPLCOMPLIANCE GPLCOMPLIANCE A GUIDE FOR STARTUPS, SMALL ABUSINESSES GUIDE FOR STARTUPS, AND ENGINEERS SMALL BUSINESSES AND ENGINEERS ARMIJN HEMEL, MSC AND SHANE COUGHLAN ARMIJN HEMEL, MSC AND SHANE COUGHLAN Copyright © 2017 Linux Foundation All rights reserved. This book or any portion thereof may not be reproduced or used in any manner whatsoever without the express written permission of the publisher except for the use of brief quotations in a book review and certain other noncommercial uses permitted by copyright law. Printed in the United States of America First Edition, 2017 ISBN: 978-0-9989078-0-2 1 Letterman Drive Building D Suite D4700 San Francisco CA 94129 Phone/Fax: +1 415 723 9709 https://linuxfoundation.org About the Authors Shane Coughlan Shane Coughlan is an expert in communi- cation, security, and business development. His professional accomplishments include spearheading the licensing team that elevated Open Invention Network into the largest patent non-aggression community in history, establishing the leading professional network of open source legal experts, and aligning stakeholders to launch both the first law journal and the first law book dedicated to open source. He currently leads the OpenChain community as Program Manager. Shane has extensive knowledge of open source governance, internal process development, supply chain management, and community building. His experience includes engagement with the enterprise, embedded, mobile, and automotive industries. Armijn Hemel Armijn Hemel is the owner of Tjaldur Software Governance Solutions. He is an active re- searcher of and internationally recognized expert in open source license compliance and supply chain management. He studied computer science at Utrecht University in The Netherlands, where he pioneered reproducible builds with NixOS. -
Open Source Used in CVR100W 1.0.1.1X
Open Source Used In CVR100W 1.0.1.1x Cisco Systems, Inc. www.cisco.com Cisco has more than 200 offices worldwide. Addresses, phone numbers, and fax numbers are listed on the Cisco website at www.cisco.com/go/offices. Text Part Number: 78EE117C99-35996155 78-21097-01 Open Source Used In CVR100W 1.0.1.1x 1 This document contains the licenses and notices for open source software used in this product. With respect to the free/open source software listed in this document, if you have any questions or wish to receive a copy of the source code to which you are entitled under the applicable free/open source license(s) (such as the GNU Lesser/General Public License), please contact us at [email protected]. In your requests please include the following reference number 78EE117C99-35996155 En ce qui a trait au logiciel gratuit ou à exploitation libre figurant dans ce document, si vous avez des questions ou souhaitez recevoir une copie du code source, auquel vous avez droit en vertu des licences gratuites ou d'exploitation libre applicables (telles que licences GNU Lesser/General Public), veuillez communiquer avec nous à l'adresse external- [email protected]. Dans vos demandes, veuillez inclure le numéro de référence 78EE117C99-35996155 Contents 1.1 binutils 2.17 1.1.1 Available under license 1.2 brcm_rstp 0.21 1.2.1 Available under license 1.3 bridge-utils 1.0.6 1.3.1 Available under license 1.4 BusyBox 1.7.2 1.4.1 Available under license 1.5 config 1.0 1.5.1 Available under license 1.6 conntrack-tools 1.0.0 1.6.1 -
Community Notebook Kernel News Zack’S Kernel News
Community Notebook Kernel News Zack’s Kernel News Chronicler Zack Licensing Confusion performing source distribution, a complete An interesting little licensing escapade occurred machine-readable copy of the corresponding Brown reports on recently. Matthew Garrett noticed that CloudLi- source code, to be distributed under the the latest news, nux corporation had released their lve kernel terms of Sections 1 and 2 above on a medium driver under a new, proprietary license, whereas customarily used for software interchange.” views, dilemmas, before, it had been released under the GPL. So apparently, a written offer would be good Technically, nothing too fishy is going on here enough, and the three-week delay might be and developments because the original author of GPL’d code is still legally acceptable. within the Linux free to release that code under other licenses. But Matthew noticed that, in this particular Kernel Development kernel community. case, the driver still pretended to the kernel to Overflow be a GPL’d driver and still used kernel symbols Thomas Gleixner posed an interesting ques- By Zack Brown that were restricted to GPL-only code. tion – all the more interesting in that it was That’s a big no-no, and Matthew submitted taken so seriously. He pointed out that inter- a patch to make the kernel automatically treat est in the kernel was continuing to grow and the lve module as non-GPL, whether it said it that the number of patch submissions from was or not. But that wasn’t the end of the story individuals and corporations was growing as because licensing is a very touchy legal sub- well. -
BERKELEY PACKET FILTER: Theory, Practice and Perspectives
Alma Mater Studiorum · Universita` di Bologna SCUOLA DI SCIENZE Corso di Laurea in Informatica BERKELEY PACKET FILTER: theory, practice and perspectives Relatore: Presentata da: Chiar.mo Prof. MICHELE DI STEFANO RENZO DAVOLI Sessione II Anno Accademico 2019/2020 All operating systems sucks, but Linux just sucks less. Linus Torvalds Introduction Initially packet filtering mechanism in many Unix versions was imple- mented in the userspace, meaning that each packet was copied from the kernel-space to the user-space before being filtered. This approach resulted to be inefficient compared with the performance shown by the introduction of the BSD classic Berkeley Packet Filter (cBPF). cBPF consists of an as- sembly language for a virtual machine which resides inside the kernel. The assembly language can be used to write filters that are loaded in to the ker- nel from the user-space allowing the filtering to happen in the kernel-space without copying each packet as before. cBPF use is not limited to just the networking domain but it is also applied as a mechanism to filter system calls through seccomp mode. Seccomp allows the programmer to arbitrary select which system calls to permit, representing an useful mechanism to implement sandboxing. In order to increase the number of use cases and to update the architecture accordingly to new advancements in modern processors, the virtual machine has been rewritten and new features have been added. The result is extended Berkeley Packet Filter (eBPF) which consists of a richer assembly, more pro- gram types, maps to store key/value pairs and more components. Currently eBPF (or just BPF) is under continuous development and its capacities are evolving, although the main uses are networking and tracing.