Jails: Confining the Omnipotent Root
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Iocage Documentation Release 1.2
iocage Documentation Release 1.2 Brandon Schneider and Peter Toth Sep 26, 2019 Contents 1 Documentation: 3 1.1 Install iocage...............................................3 1.2 Basic Usage...............................................6 1.3 Plugins.................................................. 10 1.4 Networking................................................ 11 1.5 Jail Types................................................. 14 1.6 Best Practices............................................... 15 1.7 Advanced Usage............................................. 16 1.8 Using Templates............................................. 20 1.9 Create a Debian Squeeze Jail (GNU/kFreeBSD)............................ 21 1.10 Known Issues............................................... 22 1.11 FAQ.................................................... 23 1.12 Indices and tables............................................ 24 Index 25 i ii iocage Documentation, Release 1.2 iocage is a jail/container manager written in Python, combining some of the best features and technologies the FreeBSD operating system has to offer. It is geared for ease of use with a simplistic and easy to learn command syntax. FEATURES: • Templates, basejails, and normal jails • Easy to use • Rapid thin provisioning within seconds • Automatic package installation • Virtual networking stacks (vnet) • Shared IP based jails (non vnet) • Dedicated ZFS datasets inside jails • Transparent ZFS snapshot management • Binary updates • Export and import • And many more! Contents 1 iocage Documentation, -
Proceedings of the Bsdcon 2002 Conference
USENIX Association Proceedings of the BSDCon 2002 Conference San Francisco, California, USA February 11-14, 2002 THE ADVANCED COMPUTING SYSTEMS ASSOCIATION © 2002 by The USENIX Association All Rights Reserved For more information about the USENIX Association: Phone: 1 510 528 8649 FAX: 1 510 548 5738 Email: [email protected] WWW: http://www.usenix.org Rights to individual papers remain with the author or the author's employer. Permission is granted for noncommercial reproduction of the work for educational or research purposes. This copyright notice must be included in the reproduced paper. USENIX acknowledges all trademarks herein. Rethinking /devand devices in the UNIX kernel Poul-Henning Kamp <[email protected]> The FreeBSD Project Abstract An outstanding novelty in UNIX at its introduction was the notion of ‘‘a file is a file is a file and evenadevice is a file.’’ Going from ‘‘hardware only changes when the DEC Field engineer is here’’to‘‘my toaster has USB’’has put serious strain on the rather crude implementation of the ‘‘devices as files’’concept, an implementation which has survivedpractically unchanged for 30 years in most UNIX variants. Starting from a high-levelviewofdevices and the semantics that have grown around them overthe years, this paper takes the audience on a grand tour of the redesigned FreeBSD device-I/O system, to convey anoverviewofhow itall fits together,and to explain whythings ended up as theydid, howtouse the newfeatures and in particular hownot to. 1. Introduction tax and meaning, so that a program expecting a file name as a parameter can be passed a device name; There are really only twofundamental ways to concep- finally,special files are subject to the same protec- tualise I/O devices in an operating system: The usual tion mechanism as regular files. -
Freebsd's Jail(2) Facility
Lousy virtualization, Happy users: FreeBSD's jail(2) facility Poul-Henning Kamp [email protected] CHROOT(2) FreeBSD System Calls Manual CHROOT(2) NAME chroot -- change root directory LIBRARY Standard C Library (libc, -lc) SYNOPSIS #include <unistd.h> int chroot(const char *dirname); Calling chroot(2) in ftpd(1) implemented ”anonymous FTP” without the hazzle of file/pathname parsing and editing. ”anonymous FTP” became used as a tool to enhance network security. By inference, chroot(2) became seen as a security enhancing feature. ...The source were not strong in those. Exercise 1: List at least four ways to escape chroot(2). Then the Internet happened, ...and web-servers, ...and web-hosting Virtual hosts in Apache User get their own ”virtual apache” but do do not get your own machine. Also shared: Databases mailprograms PHP/Perl etc. Upgrading tools (PHP, mySQL etc) on virtual hosting machines is a nightmare. A really bad nightmare: Cust#1 needs mySQL version > N Cust#2 cannot use mySQL version <M (unless PHP version > K) Cust#3 does not answer telephone Cust#4 has new sysadmin Cust#5 is just about ready with new version Wanted: Lightweight virtualization Same kernel, but virtual filesystem and network address plus root limitations. Just like chroot(2) with IP numbers on top. Will pay cash. Close holes in chroot(2) Introduce ”jail” syscall + kernel struct Block jailed root in most suser(9) calls. Check ”if jail, same jail ?” in strategic places. Fiddle socket syscall arguments: INADDR_ANY -> jail.ip INADDR_LOOPBACK -> jail.ip Not part of jail(2): Resource restriction Hardware virtualization Covert channel prevention (the hard stuff) Total implementation: 350 changed source lines 400 new lines of code FreeBSD without jail usr Resources of various sorts / home var process process process process process process Kernel FreeBSD with jail usr Resources of various sorts / home var process process process process* process process Kernel error = priv_check_cred( cred, PRIV_VFS_LINK, SUSER_ALLOWJAIL); if (error) return (error); The unjailed part One jailed part of the system. -
Sandboxing 2 Change Root: Chroot()
Sandboxing 2 Change Root: chroot() Oldest Unix isolation mechanism Make a process believe that some subtree is the entire file system File outside of this subtree simply don’t exist Sounds good, but. Sandboxing 2 2 / 47 Chroot Sandboxing 2 3 / 47 Limitations of Chroot Only root can invoke it. (Why?) Setting up minimum necessary environment can be painful The program to execute generally needs to live within the subtree, where it’s exposed Still vulnerable to root compromise Doesn’t protect network identity Sandboxing 2 4 / 47 Root versus Chroot Suppose an ordinary user could use chroot() Create a link to the sudo command Create /etc and /etc/passwd with a known root password Create links to any files you want to read or write Besides, root can escape from chroot() Sandboxing 2 5 / 47 Escaping Chroot What is the current directory? If it’s not under the chroot() tree, try chdir("../../..") Better escape: create device files On Unix, all (non-network) devices have filenames Even physical memory has a filename Create a physical memory device, open it, and change the kernel data structures to remove the restriction Create a disk device, and mount a file system on it. Then chroot() to the real root (On Unix systems, disks other than the root file system are “mounted” as a subtree somewhere) Sandboxing 2 6 / 47 Trying Chroot # mkdir /usr/sandbox /usr/sandbox/bin # cp /bin/sh /usr/sandbox/bin/sh # chroot /usr/sandbox /bin/sh chroot: /bin/sh: Exec format error # mkdir /usr/sandbox/libexec # cp /libexec/ld.elf_so /usr/sandbox/libexec # chroot /usr/sandbox -
The Complete Freebsd
The Complete FreeBSD® If you find errors in this book, please report them to Greg Lehey <grog@Free- BSD.org> for inclusion in the errata list. The Complete FreeBSD® Fourth Edition Tenth anniversary version, 24 February 2006 Greg Lehey The Complete FreeBSD® by Greg Lehey <[email protected]> Copyright © 1996, 1997, 1999, 2002, 2003, 2006 by Greg Lehey. This book is licensed under the Creative Commons “Attribution-NonCommercial-ShareAlike 2.5” license. The full text is located at http://creativecommons.org/licenses/by-nc-sa/2.5/legalcode. You are free: • to copy, distribute, display, and perform the work • to make derivative works under the following conditions: • Attribution. You must attribute the work in the manner specified by the author or licensor. • Noncommercial. You may not use this work for commercial purposes. This clause is modified from the original by the provision: You may use this book for commercial purposes if you pay me the sum of USD 20 per copy printed (whether sold or not). You must also agree to allow inspection of printing records and other material necessary to confirm the royalty sums. The purpose of this clause is to make it attractive to negotiate sensible royalties before printing. • 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. • For any reuse or distribution, you must make clear to others the license terms of this work. • 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. -
Kratka Povijest Unixa Od Unicsa Do Freebsda I Linuxa
Kratka povijest UNIXa Od UNICSa do FreeBSDa i Linuxa 1 Autor: Hrvoje Horvat Naslov: Kratka povijest UNIXa - Od UNICSa do FreeBSDa i Linuxa Licenca i prava korištenja: Svi imaju pravo koristiti, mijenjati, kopirati i štampati (printati) knjigu, prema pravilima GNU GPL licence. Mjesto i godina izdavanja: Osijek, 2017 ISBN: 978-953-59438-0-8 (PDF-online) URL publikacije (PDF): https://www.opensource-osijek.org/knjige/Kratka povijest UNIXa - Od UNICSa do FreeBSDa i Linuxa.pdf ISBN: 978-953- 59438-1- 5 (HTML-online) DokuWiki URL (HTML): https://www.opensource-osijek.org/dokuwiki/wiki:knjige:kratka-povijest- unixa Verzija publikacije : 1.0 Nakalada : Vlastita naklada Uz pravo svakoga na vlastito štampanje (printanje), prema pravilima GNU GPL licence. Ova knjiga je napisana unutar inicijative Open Source Osijek: https://www.opensource-osijek.org Inicijativa Open Source Osijek je član udruge Osijek Software City: http://softwarecity.hr/ UNIX je registrirano i zaštićeno ime od strane tvrtke X/Open (Open Group). FreeBSD i FreeBSD logo su registrirani i zaštićeni od strane FreeBSD Foundation. Imena i logo : Apple, Mac, Macintosh, iOS i Mac OS su registrirani i zaštićeni od strane tvrtke Apple Computer. Ime i logo IBM i AIX su registrirani i zaštićeni od strane tvrtke International Business Machines Corporation. IEEE, POSIX i 802 registrirani i zaštićeni od strane instituta Institute of Electrical and Electronics Engineers. Ime Linux je registrirano i zaštićeno od strane Linusa Torvaldsa u Sjedinjenim Američkim Državama. Ime i logo : Sun, Sun Microsystems, SunOS, Solaris i Java su registrirani i zaštićeni od strane tvrtke Sun Microsystems, sada u vlasništvu tvrtke Oracle. Ime i logo Oracle su u vlasništvu tvrtke Oracle. -
April 2006 Volume 31 Number 2
APRIL 2006 VOLUME 31 NUMBER 2 THE USENIX MAGAZINE OPINION Musings RIK FARROW OpenSolaris:The Model TOM HAYNES PROGRAMMING Code Testing and Its Role in Teaching BRIAN KERNIGHAN Modular System Programming in MINIX 3 JORRIT N. HERDER, HERBERT BOS, BEN GRAS, PHILIP HOMBURG, AND ANDREW S. TANENBAUM Some Types of Memory Are More Equal Than Others DIOMEDIS SPINELLIS Simple Software Flow Analysis Using GNU Cflow CHAOS GOLUBITSKY Why You Should Use Ruby LU KE KANIES SYSADMIN Unwanted HTTP:Who Has the Time? DAVI D MALONE Auditing Superuser Usage RANDOLPH LANGLEY C OLUMNS Practical Perl Tools:Programming, Ho Hum DAVID BLANK-EDELMAN VoIP Watch HEISON CHAK /dev/random ROBERT G. FERRELL STANDARDS USENIX Standards Activities NICHOLAS M. STOUGHTON B O OK REVIEWS Book Reviews ELIZABETH ZWICKY, WITH SAM STOVER AND RI K FARROW USENIX NOTES Letter to the Editor TED DOLOTTA Fund to Establish the John Lions Chair C ONFERENCES LISA ’05:The 19th Large Installation System Administration Conference WORLDS ’05: Second Workshop on Real, Large Distributed Systems FAST ’05: 4th USENIX Conference on File and Storage Technologies The Advanced Computing Systems Association Upcoming Events 3RD SYMPOSIUM ON NETWORKED SYSTEMS 2ND STEPS TO REDUCING UNWANTED TRAFFIC ON DESIGN AND IMPLEMENTATION (NSDI ’06) THE INTERNET WORKSHOP (SRUTI ’06) Sponsored by USENIX, in cooperation with ACM SIGCOMM JULY 6–7, 2006, SAN JOSE, CA, USA and ACM SIGOPS http://www.usenix.org/sruti06 MAY 8–10, 2006, SAN JOSE, CA, USA Paper submissions due: April 20, 2006 http://www.usenix.org/nsdi06 2006 -
In PDF Format
Arranging Your Virtual Network on FreeBSD Michael Gmelin ([email protected]) January 2020 1 CONTENTS CONTENTS Contents Introduction 3 Document Conventions . .3 License . .3 Plain Jails 4 Plain Jails Using Inherited IP Configuration . .4 Plain Jails Using a Dedicated IP Address . .5 Plain Jails Using a VLAN IP Address . .6 Plain Jails Using a Loopback IP Address . .7 Adding Outbound NAT for Public Traffic . .7 Running a Service and Redirecting Traffic to It . .9 VNET Jails and bhyve VMs 10 VNET Jails Using sysutils/pot ............................. 10 VNET Jails Using sysutils/iocage ............................ 13 Managing Bridges . 13 Adding bhyve VMs and DHCP to the Mix . 16 Preventing Traffic Between VNET Jails/VMs . 17 Firewalling Inside VNET Jails/VMs . 20 VXLAN 22 VXLAN Example Overview . 22 Gateway Configuration . 24 Jailhost-a . 25 Network Configuration (jailhost-a) . 25 VM Configuration (jailhost-a) . 26 Jail Configuration (jailhost-a) . 27 Jailhost-b . 27 Network Configuration (jailhost-b) . 27 Plain Jail Configuration (jailhost-b) . 28 Network Switch Setup (jailhost-b) . 29 VNET Jail Configuration (jailhost-b) . 30 VM Configuration (jailhost-b) . 30 VXLAN Multicast Troubleshooting . 31 Conclusion and Further Reading 33 2020-01-08 (final) 2 CC BY 4.0 INTRODUCTION Introduction Modern FreeBSD offers a range of virtualization options, from the traditional jail environment sharing the network stack with the host operating system, over vnet jails, which allow each jail to have its own network stack, to bhyve virtual machines running their own kernels/operating systems. Depending on individual requirements, there are different ways to configure the virtual network. Jail and VM management tools can ease the process by abstracting away (at least some of) the underlying complexities. -
Running Untrusted Application Code: Sandboxing Running Untrusted Code
Running Untrusted Application Code: Sandboxing Running untrusted code We often need to run buggy/unstrusted code: programs from untrusted Internet sites: toolbars, viewers, codecs for media player old or insecure applications: ghostview, outlook legacy daemons: sendmail, bind honeypots Goal : if application “misbehaves,” kill it Approach: confinement Confinement : ensure application does not deviate from pre-approved behavior Can be implemented at many levels: Hardware : run application on isolated hw (air gap) difficult to manage Virtual machines : isolate OS’s on single hardware System call interposition : Isolates a process in a single operating system Isolating threads sharing same address space: Software Fault Isolation (SFI) Application specific: e.g. browser-based confinement Implementing confinement Key component: reference monitor Mediates requests from applications Implements protection policy Enforces isolation and confinement Must always be invoked: Every application request must be mediated Tamperproof : Reference monitor cannot be killed … or if killed, then monitored process is killed too Small enough to be analyzed and validated A simple example: chroot Often used for “guest” accounts on ftp sites To use do: (must be root) chroot /tmp/guest root dir “/” is now “/tmp/guest” su guest EUID set to “guest” Now “/tmp/guest” is added to file system accesses for applications in jail open(“/etc/passwd”, “r”) ⇒⇒⇒ open(“/tmp/guest/etc/passwd”, “r”) ⇒ application cannot access files outside of jail Jailkit Problem: all utility progs (ls, ps, vi) must live inside jail • jailkit project: auto builds files, libs, and dirs needed in jail environment • jk_init : creates jail environment • jk_check: checks jail env for security problems • checks for any modified programs, • checks for world writable directories, etc. -
User-Space Process Virtualization in the Context of Checkpoint-Restart and Virtual Machines
User-Space Process Virtualization in the Context of Checkpoint-Restart and Virtual Machines A dissertation presented by Kapil Arya to the Faculty of the Graduate School of the College of Computer and Information Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy Northeastern University Boston, Massachusetts August 2014 Copyright c August 2014 by Kapil Arya NORTHEASTERN UNIVERSITY GRADUATE SCHOOL OF COMPUTER SCIENCE Ph.D. THESIS APPROVAL FORM THESIS TITLE: User-Space Process Virtualization in the Context of Checkpoint-Restart and Virtual Machines AUTHOR: Kapil Arya Ph.D. Thesis approved to complete all degree requirements for the Ph.D. degree in Computer Science Distribution: Once completed, this form should be scanned and attached to the front of the electronic dissertation document (page 1). An electronic version of the document can then be uploaded to the Northeastern University-UMI website. Abstract Checkpoint-Restart is the ability to save a set of running processes to a check- point image on disk, and to later restart them from the disk. In addition to its traditional use in fault tolerance, recovering from a system failure, it has numerous other uses, such as for application debugging and save/restore of the workspace of an interactive problem-solving environment. Transparent checkpointing operates without modifying the underlying application pro- gram, but it implicitly relies on a “Closed World Assumption” — the world (including file system, network, etc.) will look the same upon restart as it did at the time of checkpoint. This is not valid for more complex programs. Until now, checkpoint-restart packages have adopted ad hoc solutions for each case where the environment changes upon restart. -
Jails and Unikernels
Virtualisation: Jails and Unikernels Advanced Operating Systems Lecture 18 Colin Perkins | https://csperkins.org/ | Copyright © 2017 | This work is licensed under the Creative Commons Attribution-NoDerivatives 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nd/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA. Lecture Outline • Alternatives to full virtualisation • Sandboxing processes: • FreeBSD jails and Linux containers • Container management • Unikernels and library operating systems Colin Perkins | https://csperkins.org/ | Copyright © 2017 2 Alternatives to Full Virtualisation • Full operating system virtualisation is expensive • Need to run a hypervisor • Need to run a complete guest operating system instance for each VM • High memory and storage overhead, high CPU load from running multiple OS instances on a single machine – but excellent isolation between VMs • Running multiple services on a single OS instance can offer insufficient isolation • All must share the same OS • A bug in a privileged service can easily compromise entire system – all services running on the host, and any unrelated data • A sandbox is desirable – to isolate multiple services running on a single operating system Colin Perkins | https://csperkins.org/ | Copyright © 2017 3 Sandboxing: Jails and Containers • Concept – lightweight virtualisation • A single operating system kernel • Multiple services /bin • Each service runs within a jail a service specific container, running just what’s needed /bin /dev for that application /dev /etc /etc /mail /home /home /jail /www /lib • Jail restricted to see only a subset of the / /lib /local /usr filesystem and processes of the host /usr /lib /sbin • A sandbox within the operating system /sbin /sbin /tmp /tmp /share /var • Partially virtualised /var Colin Perkins | https://csperkins.org/ | Copyright © 2017 4 Example: FreeBSD Jail subsystem Jails: Confining the omnipotent root. -
BSD Professional Certification Job Task Analysis Survey Results
BSD Professional Certification Job Task Analysis Survey Results March 21, 2010 BSD Professional Job Task Analysis Survey Results 2 Copyright © 2010 BSD Certification Group All Rights Reserved All trademarks are owned by their respective companies. This work is protected by a Creative Commons License which requires attribution and prevents commercial and derivative works. The human friendly version of the license can be viewed at http://creativecommons.org/licenses/by-nc-nd/3.0/ which also provides a hyperlink to the legal code. These conditions can only be waived by written permission from the BSD Certification Group. See the website for contact details. BSD Daemon Copyright 1988 by Marshall Kirk McKusick. All Rights Reserved. Puffy Artwork Copyright© 2004 by OpenBSD. FreeBSD® is a registered trademark of The FreeBSD Foundation, Inc. NetBSD® is a registered trademark of The NetBSD Foundation, Inc. The NetBSD Logo Copyright© 2004 by The NetBSD Foundation, Inc. Fred Artwork Copyright© 2005 by DragonFly BSD. Use of the above names, trademarks, logos, and artwork does not imply endorsement of this certification program by their respective owners. www.bsdcertification.org BSD Professional Job Task Analysis Survey Results 3 Table of Contents Executive Summary ................................................................................................................................... 9 Introduction .............................................................................................................................................