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Episode 269: Tiny Daemon Lib | BSD Now 269

FreeBSD Foundation September Update, tiny C lib for programming Unix daemons, EuroBSDcon trip reports, GhostBSD tested on real hardware, and a BSD auth module for duress. ##Headlines ###FreeBSD Foundation Update, September 2018 MESSAGE FROM THE EXECUTIVE DIRECTOR Dear FreeBSD Community Member, It is hard to believe that September is over. The Foundation team had a busy month promoting FreeBSD all over the globe, bug fixing in preparation for 12.0, and setting plans in motion to kick off our 4th quarter fundraising and advocacy efforts. Take a minute to see what we’ve been up to and please consider making a donation to help us continue our efforts supporting FreeBSD! September 2018 Development Projects Update In preparation for the release of FreeBSD 12.0, I have been working on investigating and fixing a backlog of kernel bug reports. Of course, this kind of work is never finished, and we will continue to make progress after the release. In the past couple of months I have fixed a combination of long-standing issues and recent regressions. Of note are a pair of UNIX domain socket bugs which had been affecting various applications for years. In particular, Chromium tabs would frequently hang unless a workaround was manually applied to the system, and the bug had started affecting recent versions of Firefox as well. Fixing these issues gave me an opportunity to revisit and extend our regression testing for UNIX sockets, which, in turn, resulted in some related bugs being identified and fixed. Of late I have also been investigating reports of issues with ZFS, particularly, those reported on FreeBSD 11.2. A number of regressions, including a kernel memory leak and issues with ARC reclamation, have already been fixed for 12.0; investigation of other reports is ongoing. Those who closely follow FreeBSD-CURRENT know that some exciting work to improve memory usage on NUMA systems is now enabled by default. As is usually the case when new code is deployed in a diverse array of systems and workloads, a number of problems since have been identified. We are working on resolving them as soon as possible to ensure the quality of the release. I’m passionate about maintaining FreeBSD’s stability and dependability as it continues to expand and grow new features, and I’m grateful to the FreeBSD Foundation for sponsoring this work. We depend on users to report problems to the mailing lists and via the bug tracker, so please try running the 12.0 candidate builds and help us make 12.0 a great release. Fundraising Update: Supporting the Project It’s officially Fall here at Foundation headquarters and we’re heading full-steam into our final fundraising campaign of the year. We couldn’t even have begun to reach our funding goal of $1.25 million dollars without the support from the companies who have partnered with us this year. Thank you to Verisign for becoming a Silver Partner. They now join a growing list of companies like Xiplink, NetApp, Microsoft, Tarsnap, VMware, and NeoSmart Technologies that are stepping up and showing their commitment to FreeBSD! Funding from commercial users like these and individual users like yourself, help us continue our efforts of supporting critical areas of FreeBSD such as: Operating System Improvements: Providing staff to immediately respond to urgent problems and implement new features and functionality allowing for the innovation and stability you’ve come to rely on. Security: Providing engineering resources to bolster the capacity and responsiveness of the Security team providing your users with piece of mind when security issues arise. Release Engineering: Continue providing a full-time release engineer, resulting in timely and reliable releases you can plan around. Quality Assurance: Improving and increasing test coverage, continuous integration, and automated testing with a full-time software engineer to ensure you receive the highest quality, secure, and reliable operating system. New User Experience: Improving the process and documentation for getting new people involved with FreeBSD, and supporting those people as they become integrated into the FreeBSD Community providing the resources you may need to get new folks up to speed. Training: Supporting more FreeBSD training for undergraduates, graduates, and postgraduates. Growing the community means reaching people and catching their interest in systems software as early as possible and providing you with a bigger pool of candidates with the FreeBSD skills you’re looking for. Face-to-Face Opportunities: Facilitating collaboration among members of the community, and building connections throughout the industry to support a healthy and growing ecosystem and make it easier for you to find resources when questions emerge . We can continue the above work, if we meet our goal this year! If your company uses FreeBSD, please consider joining our growing list of 2018 partners. If you haven’t made your donation yet, please consider donating today.

Oct 24, 20181h 28m

Episode 268: Netcat Demystified | BSD Now 268

6 metrics for zpool performance, 2FA with ssh on OpenBSD, ZFS maintaining file type information in dirs, everything old is new again, netcat demystified, and more. ##Headlines ###Six Metrics for Measuring ZFS Pool Performance Part 1 The layout of a ZFS storage pool has a significant impact on system performance under various workloads. Given the importance of picking the right configuration for your workload and the fact that making changes to an in-use ZFS pool is far from trivial, it is important for an administrator to understand the mechanics of pool performance when designing a storage system. To quantify pool performance, we will consider six primary metrics: Read I/O operations per second (IOPS) Write IOPS Streaming read speed Streaming write speed Storage space efficiency (usable capacity after parity versus total raw capacity) Fault tolerance (maximum number of drives that can fail before data loss) For the sake of comparison, we’ll use an example system with 12 drives, each one sized at 6TB, and say that each drive does 100MB/s streaming reads and writes and can do 250 read and write IOPS. We will visualize how the data is spread across the drives by writing 12 multi-colored blocks, shown below. The blocks are written to the pool starting with the brown block on the left (number one), and working our way to the pink block on the right (number 12). Note that when we calculate data rates and IOPS values for the example system, they are only approximations. Many other factors can impact pool access speeds for better (compression, caching) or worse (poor CPU performance, not enough memory). There is no single configuration that maximizes all six metrics. Like so many things in life, our objective is to find an appropriate balance of the metrics to match a target workload. For example, a cold-storage backup system will likely want a pool configuration that emphasizes usable storage space and fault tolerance over the other data-rate focused metrics. Let’s start with a quick review of ZFS storage pools before diving into specific configuration options. ZFS storage pools are comprised of one or more virtual devices, or vdevs. Each vdev is comprised of one or more storage providers, typically physical hard disks. All disk-level redundancy is configured at the vdev level. That is, the RAID layout is set on each vdev as opposed to on the storage pool. Data written to the storage pool is then striped across all the vdevs. Because pool data is striped across the vdevs, the loss of any one vdev means total pool failure. This is perhaps the single most important fact to keep in mind when designing a ZFS storage system. We will circle back to this point in the next post, but keep it in mind as we go through the vdev configuration options. Because storage pools are made up of one or more vdevs with the pool data striped over the top, we’ll take a look at pool configuration in terms of various vdev configurations. There are three basic vdev configurations: striping, mirroring, and RAIDZ (which itself has three different varieties). The first section will cover striped and mirrored vdevs in this post; the second post will cover RAIDZ and some example scenarios. A striped vdev is the simplest configuration. Each vdev consists of a single disk with no redundancy. When several of these single-disk, striped vdevs are combined into a single storage pool, the total usable storage space would be the sum of all the drives. When you write data to a pool made of striped vdevs, the data is broken into small chunks called “blocks” and distributed across all the disks in the pool. The blocks are written in “round-robin” sequence, meaning after all the disks receive one row of blocks, called a stripe, it loops back around and writes another stripe under the first. A striped pool has excellent performance and storage space efficiency, but absolutely zero fault tolerance. If even a single drive in the pool fails, the entire pool will fail and all data stored on that pool will be lost. The excellent performance of a striped pool comes from the fact that all of the disks can work independently for all read and write operations. If you have a bunch of small read or write operations (IOPS), each disk can work independently to fetch the next block. For streaming reads and writes, each disk can fetch the next block in line synchronized with its neighbors. For example, if a given disk is fetching block n, its neighbor to the left can be fetching block n-1, and its neighbor to the right can be fetching block n+1. Therefore, the speed of all read and write operations as well as the quantity of read and write operations (IOPS) on a striped pool will scale with the number of vdevs. Note here that I said the speeds and IOPS scale with the number of vdevs rather than the number of drives; there’s a reason for this and we’ll cover it in the next post when we discuss RAID-Z. Here’s a summary of the total pool performance (where N is the number of

Oct 17, 20181h 7m

Episode 267: Absolute FreeBSD | BSD Now 267

We have a long interview with fiction and non-fiction author Michael W. Lucas for you this week as well as questions from the audience. ##Headlines ##Interview - Michael W. Lucas - [email protected] / @mwlauthor BR: [Welcome Back] AJ: What have you been doing since last we talked to you [ed, ssh, and af3e] BR: Tell us more about AF3e AJ: How did the first Absolute FreeBSD come about? BR: Do you have anything special planned for MeetBSD? AJ: What are you working on now? [FM:Jails, Git sync Murder] BR: What are your plans for next year? AJ: How has SEMIBug been going? Auction at https://mwl.io Patreon Link: ##Feedback/Questions Paul - Recent bhyve related videos (daemon) Michael - freebsd-update question Sigflup - pkg file search Send questions, comments, show ideas/topics, or stories you want mentioned on the show to [email protected]

Oct 10, 20181h 7m

Episode 266: File Type History | BSD Now 266

Running OpenBSD/NetBSD on FreeBSD using grub2-bhyve, vermaden’s FreeBSD story, thoughts on OpenBSD on the desktop, history of file type info in Unix dirs, Multiboot a Pinebook KDE neon image, and more. ##Headlines ###OpenBSD/NetBSD on FreeBSD using grub2-bhyve When I was writing a blog post about the process title, I needed a couple of virtual machines with OpenBSD, NetBSD, and Ubuntu. Before that day I mainly used FreeBSD and Windows with bhyve. I spent some time trying to set up an OpenBSD using bhyve and UEFI as described here. I had numerous problems trying to use it, and this was the day I discovered the grub2-bhyve tool, and I love it! The grub2-bhyve allows you to load a kernel using GRUB bootloader. GRUB supports most of the operating systems with a standard configuration, so exactly the same method can be used to install NetBSD or Ubuntu. First, let’s install grub2-bhyve on our FreeBSD box: # pkg install grub2-bhyve To run grub2-bhyve we need to provide at least the name of the VM. In bhyve, if the memsize is not specified the default VM is created with 256MB of the memory. # grub-bhyve test GNU GRUB version 2.00 Minimal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists possible device or file completions. grub> After running grub-bhyve command we will enter the GRUB loader. If we type the ls command, we will see all the available devices. In the case of the grub2-bhyve there is one additional device called “(host)” that is always available and allows the host filesystem to be accessed. We can list files under that device. grub> ls (host) grub> ls (host)/ libexec/ bin/ usr/ bhyve/ compat/ tank/ etc/ boot/ net/ entropy proc/ lib/ root/ sys/ mnt/ rescue/ tmp/ home/ sbin/ media/ jail/ COPYRIGHT var/ dev/ grub> To exit console simply type ‘reboot’. I would like to install my new operating system under a ZVOL ztank/bhyve/post. On another terminal, we create: # zfs create -V 10G ztank/bhyve/post If you don’t use ZFS for some crazy reason you can also create a raw blob using the truncate(1) command. # truncate -s 10G post.img I recommend installing an operating system from the disk image (installXX.fs for OpenBSD and NetBSD-X.X-amd64-install.img for NetBSD). Now we need to create a device map for a GRUB. cat > /tmp/post.map << EOF (hd0) /directory/to/disk/image (hd1) /dev/zvol/ztank/bhyve/post EOF The mapping files describe the names for files in the GRUB. In our case under hd0 we will have an installation image and in hd1 we will have our ZVOL/blob. You can also try to use an ISO image then instead of using hd0 device name use a cd0. When we will run the grub-bhyve command we will see two additional devices. # grub-bhyve -m /tmp/post.map post grub> ls (hd0) (hd0,msdos4) (hd0,msdos1) (hd0,openbsd9) (hd0,openbsd1) (hd1) (host) The hd0 (in this example OpenBSD image) contains multiple partitions. We can check what is on it. grub> ls (hd0,msdos4)/ boot bsd 6.4/ etc/ And this is the partition that contains a kernel. Now we can set a root device, load an OpenBSD kernel and boot: grub> set root=(hd0,msdos4) grub> kopenbsd -h com0 -r sd0a /bsd grub> boot After that, we can run bhyve virtual machine. In my case it is: # bhyve -c 1 -w -u -H \ -s 0,amd_hostbridge \ -s 3,ahci-hd,/directory/to/disk/image \ -s 4,ahci-hd,/dev/zvol/ztank/bhyve/post \ -s 31,lpc -l com1,stdio \ post Unfortunately explaining the whole bhyve(8) command line is beyond this article. After installing the operating system remove hd0 from the mapping file and the image from the bhyve(8) command. If you don’t want to type all those GRUB commands, you can simply redirect them to the standard input. cat << EOF | grub-bhyve -m /tmp/post.map -M 512 post set root=(hd0,4) kopenbsd -h com0 -r sd0a /bsd boot EOF ###My FreeBSD Story My first devices/computers/consoles (not at the same time) that I remember were Atari 2600 and Pegasus console which was hardware clone of the Nintendo NES. Back then I did not even knew that it was Atari 2600 as I referred to it as Video Computer System … and I did not even knew any english by then. It took me about two decades to get to know (by accident) that this Video Computer System was Atari 2600 Then I got AMIGA 600 computer (or should I say my parents bought it for me) which served both for playing computer games and also other activities for the first time. AMIGA is the computer that had the greatest influence on me, as it was the first time I studied the books about Amiga Workbench operating system and learned commands from Amiga Shell terminal. I loved the idea of Ram Disk icon/directory on the desktop that allowed me to transparently put any things in system memory. I still miss that concept on today’s desktop systems … and I still remember how dismal I was when I watched Amiga Deathbed Vigil movie. At the end of 1998 I got my first PC that of course came with Windows and that computer served both as ga

Oct 3, 20181h 15m

Episode 265: Software Disenchantment | BSD Now 265

We report from our experiences at EuroBSDcon, disenchant software, LLVM 7.0.0 has been released, Thinkpad BIOS update options, HardenedBSD Foundation announced, and ZFS send vs. rsync. ##Headlines ###[FreeBSD DevSummit & EuroBSDcon 2018 in Romania] Your hosts are back from EuroBSDcon 2018 held in Bucharest, Romania this year. The first two days of the conference are used for tutorials and devsummits (FreeBSD and NetBSD), while the last two are for talks. Although Benedict organized the devsummit in large parts, he did not attend it this year. He held his Ansible tutorial in the morning of the first day, followed by Niclas Zeising’s new ports and poudriere tutorial (which had a record attendance). It was intended for beginners that had never used poudriere before and those who wanted to create their first port. The tutorial was well received and Niclas already has ideas for extending it for future conferences. On the second day, Benedict took Kirk McKusick’s “An Introduction to the FreeBSD Open-Source Operating System” tutorial, held as a one full day class this year. Although it was reduced in content, it went into enough depth of many areas of the kernel and operating system to spark many questions from attendees. Clearly, this is a good start into kernel programming as Kirk provides enough material and backstories to understand why certain things are implemented as they are. Olivier Robert took [https://www.talegraph.com/tales/l2o9ltrvsE](pictures from the devsummit) and created a nice gallery out of it. Devsummit evenings saw dinners at two restaurants that allowed developers to spend some time talking over food and drinks. The conference opened on the next day with the opening session held by Mihai Carabas. He introduced the first keynote speaker, a colleague of his who presented “Lightweight virtualization with LightVM and Unikraft”. Benedict helped out at the FreeBSD Foundation sponsor table and talked to people. He saw the following talks in between: Selfhosting as an alternative to the public cloud (by Albert Dengg) Using Boot Environments at Scale (by Allan Jude) Livepatching FreeBSD kernel (by Maciej Grochowski) FreeBSD: What to (Not) Monitor (by Andrew Fengler) FreeBSD Graphics (by Niclas Zeising) Allan spent a lot of time talking to people and helping track down issues they were having, in addition to attending many talks: Hacking together a FreeBSD presentation streaming box – For as little as possible (by Tom Jones) Introduction of FreeBSD in new environments (by Baptiste Daroussin) Keynote: Some computing and networking historical perspectives (by Ron Broersma) Livepatching FreeBSD kernel (by Maciej Grochowski) FreeBSD: What to (Not) Monitor (by Andrew Fengler) Being a BSD user (by Roller Angel) From “Hello World” to the VFS Layer: building a beadm for DragonFly BSD (by Michael Voight) We also met the winner of our Power Bagel raffle from Episode 2^8. He received the item in the meantime and had it with him at the conference, providing a power outlet to charge other people’s devices. During the closing session, GroffTheBSDGoat was handed over to Deb Goodkin, who will bring the little guy to the Grace Hopper Celebration of Women in Computing conference and then to MeetBSD later this year. It was also revealed that next year’s EuroBSDcon will be held in Lillehammer, Norway. Thanks to all the speakers, helpers, sponsors, organizers, and attendees for making it a successful conferences. There were no talks recorded this year, but the slides will be uploaded to the EuroBSDcon website in a couple of weeks. The OpenBSD talks are already available, so check them out. ###Software disenchantment I’ve been programming for 15 years now. Recently our industry’s lack of care for efficiency, simplicity, and excellence started really getting to me, to the point of me getting depressed by my own career and the IT in general. Modern cars work, let’s say for the sake of argument, at 98% of what’s physically possible with the current engine design. Modern buildings use just enough material to fulfill their function and stay safe under the given conditions. All planes converged to the optimal size/form/load and basically look the same. Only in software, it’s fine if a program runs at 1% or even 0.01% of the possible performance. Everybody just seems to be ok with it. People are often even proud about how much inefficient it is, as in “why should we worry, computers are fast enough”: @tveastman: I have a Python program I run every day, it takes 1.5 seconds. I spent six hours re-writing it in rust, now it takes 0.06 seconds. That efficiency improvement means I’ll make my time back in 41 years, 24 days :-) You’ve probably heard this mantra: “programmer time is more expensive than computer time”. What it means basically is that we’re wasting computers at an unprecedented scale. Would you buy a car if it eats 100 liters per 100 kilometers? How about 1000 liters? With computers, we do that all the time. Everything

Sep 27, 20181h 41m

Episode 264: Optimized-out | BSD Now 264

FreeBSD and DragonflyBSD benchmarks on AMD’s Threadripper, NetBSD 7.2 has been released, optimized out DTrace kernel symbols, stuck UEFI bootloaders, why ed is not a good editor today, tell your BSD story, and more. ##Headlines ###FreeBSD & DragonFlyBSD Put Up A Strong Fight On AMD’s Threadripper 2990WX, Benchmarks Against Linux The past two weeks I have been delivering a great deal of AMD Threadripper 2990WX benchmarks on Linux as well as some against Windows and Windows Server. But recently I got around to trying out some of the BSD operating systems on this 32-core / 64-thread processor to see how they would run and to see whether they would have similar scaling issues or not like we’ve seen on the Windows side against Linux. In this article are FreeBSD and DragonFlyBSD benchmarks with the X399 + 2990WX compared to a few Linux distributions. The BSDs I focused my testing on were FreeBSD 11.2-STABLE and 12.0-CURRENT/ALPHA1 (the version in development) as well as iX System’s TrueOS that is tracking FreeBSD 12.0-CURRENT. Also included were DragonFlyBSD, with FreeBSD and DragonFlyBSD being tied as my favorite operating systems when it comes to the BSDs. When it came to FreeBSD 11.2-STABLE and 12.0-ALPHA1 on the Threadripper 2990WX, it worked out surprisingly well. I encountered no real issues during my two days of benchmarking on FreeBSD (and TrueOS). It was a great experience and FreeBSD was happy to exploit the 64 threads on the system. DragonFlyBSD was a bit of a different story… Last week when I started this BSD testing I tried DragonFly 5.2.2 as the latest stable release as well as a DragonFlyBSD 5.3 development snapshot from last week: both failed to boot in either BIOS or UEFI modes. But then a few days ago DragonFlyBSD lead developer Matthew Dillon bought himself a 2990WX platform. He made the necessary changes to get DragonFlyBSD 5.3 working and he ended up finding really great performance and potential out of the platform. So I tried the latest DragonFlyBSD 5.3 daily ISO on 22 August and indeed it now booted successfully and we were off to the races. Thus there are some DragonFlyBSD 5.3 benchmarks included in this article too. Just hours ago, Matthew Dillon landed some 2990WX topology and scheduler enhancements but that fell out of the scope of when DragonFly was installed on this system. But over the weekend or so I plan to re-test DragonFlyBSD 5.3 and see how those optimizations affect the overall 2990WX performance now on that BSD. DragonFlyBSD 5.4 stable should certainly be an interesting release on several fronts! With FreeBSD 11.2-STABLE and 12.0-ALPHA1 I ran benchmarks when using their stock compiler (LLVM Clang 6.0) as well as GCC 7.3 obtained via GCC 7.3. That was done to rule out compiler differences in benchmarking against the GCC-based Linux distributions. On DragonFlyBSD 5.3 it defaults to the GCC 5.4.1 but via pkg I also did a secondary run when upgraded to GCC 7.3. The hardware and BIOS/UEFI settings were maintained the same throughout the entire benchmarking process. The system was made up of the AMD Ryzen Threadripper 2990WX at stock speeds, the ASUS ROG ZENITH EXTREME motherboard, 4 x 8GB DDR4-3200MHz memory, Samsung 970 EVO 500GB NVMe SSD, and Radeon RX Vega 56 graphics card. All of these Linux vs. BSD benchmarks were carried out in a fully-automated and reproducible manner using the open-source Phoronix Test Suite benchmarking framework. While for the last of today’s BSD vs. Linux benchmarking on the Threadripper 2990WX, the Linux distributions came out slightly ahead of FreeBSD and DragonFlyBSD with GCC (another test having issues with Clang 6.0 on the BSDs). Overall, I was quite taken away by the BSD performance on the Threadripper 2990WX – particularly FreeBSD. In a surprising number of benchmarks, the BSDs were outperforming the tested Linux distributions though often by incredibly thin margins. Still, quite an accomplishment for these BSD operating systems and considering how much better Linux is already doing than Windows 10 / Windows Server on this 32-core / 64-thread processor. Then again, the BSDs like Linux have a long history of running on high core/thread-count systems, super computers, and other HPC environments. It will be interesting to see how much faster DragonFlyBSD can run given today’s commit to its kernel with scheduler and topology improvements for the 2990WX. Those additional DragonFlyBSD benchmarks will be published in the coming days once they are completed. ###NetBSD 7.2 released The NetBSD Project is pleased to announce NetBSD 7.2, the second feature update of the NetBSD 7 release branch. It represents a selected subset of fixes deemed important for security or stability reasons, as well as new features and enhancements. General Security Note The NetBSD 7.2 release is a maintenance release of the netbsd-7 branch, which had it's first major release, NetBSD 7.0 in September 2015. A lot of security features have been added to later NetBSD versions, an

Sep 20, 20181h 11m

Episode 263: Encrypt That Pool | BSD Now 263

Mitigating Spectre/Meltdown on HP Proliant servers, omniOS installation setup, debugging a memory corruption issue on OpenBSD, CfT for OpenZFS native encryption, Asigra TrueNAS backup appliance shown at VMworld, NetBSD 6 EoL, and more. ##Headlines ###How to mitigate Spectre and Meltdown on an HP Proliant server with FreeBSD As recently announced in a previous article I wanted to write a couple of guides on how to mitigate Spectre and Meltdown vulnerabilities in GNU/Linux and UNIX environments. It is always a good and I hope a standard practice to have your systems patched and if they aren’t for whatever the reason (that legacy thing you’re carrying on for ages) you may take the necessary extra steps to protect your environment. I never planned to do any article on patching anything. Nowadays it’s a no brainer and operating systems have provided the necessary tools for this to be easy and as smooth as possible. So why this article? Spectre and Meltdown are both hardware vulnerabilities. Major ones. They are meaningful for several reasons among them the world wide impact since they affect Intel and AMD systems which are ubiquitous. And second because patching hardware is not as easy, for the manufacturer and for the users or administrators in charge of the systems. There is still no known exploit around left out in the open hitting servers or desktops anywhere. The question is not if it will ever happen. The question is when will it happen. And it may be sooner than later. This is why big companies, governments and people in charge of big deployments are patching or have already patched their systems. But have you done it to your system? I know you have a firewall. Have you thought about CVE-2018-3639? This particular one could make your browser being a vector to get into your system. So, no, there is no reason to skip this. Patching these set of vulnerabilities implies some more steps and concerns than updating the operating system. If you are a regular Windows user I find rare you to be here and many of the things you will read may be foreign to you. I am not planning to do a guide on Windows systems since I believe someone else has or will do it and will do it better than me since I am not a pro Windows user. However there is one basic and common thing for all OS’s when dealing with Spectre and Meltdown and that is a microcode update is necessary for the OS patches to effectively work. What is microcode? You can read the Wikipedia article but in short it is basically a layer of code that allows chip manufacturers to deal with modifications on the hardware they’ve produced and the operating systems that will manage that hardware. Since there’s been some issues (namely Spectre and Meltdown) Intel and AMD respectively have released a series of microcode updates to address those problems. First series did come with serious problems and some regressions, to the point GNU/Linux producers stopped releasing the microcode updates through their release channels for updates and placed the ball on Intel’s roof. Patching fast does always include risks, specially when dealing with hardware. OS vendors have resumed their microcode update releases so all seems to be fine now. In order to update the microcode we’re faced with two options. Download the most recent BIOS release from our vendor, provided it patches the Spectre and Meltdown vulnerabilities, or patch it from the OS. If your hardware vendor has decided not to provide support on your hardware you are forced to use the latter solution. Yes, you can still keep your hardware. They usually come accompanied with a “release notes” file where there are some explanatory notes on what is fixed, what is new, etc. To make the search easy for you a news site collected the vendors list and linked the right support pages for anyone to look. In some scenarios it would be desirable not to replace the whole BIOS but just update the microcode from the OS side. In my case I should update an HP Proliant ML110 G7 box and the download link for that would be this. Instead of using the full blown BIOS update path we’ll use the inner utilities to patch Spectre and Meltdown on FreeBSD. So let’s put our hands on it See the article for the technical breakdown ###A look beyond the BSD teacup: OmniOS installation Five years ago I wrote a post about taking a look beyond the Linux teacup. I was an Arch Linux user back then and since there were projects like ArchBSD (called PacBSD today) and Arch Hurd, I decided to take a look at and write about them. Things have changed. Today I’m a happy FreeBSD user, but it’s time again to take a look beyond the teacup of operating systems that I’m familiar with. Why Illumos / OmniOS? There are a couple of reasons. The Solaris derivatives are the other big community in the *nix family besides Linux and the BSDs and we hadn’t met so far. Working with ZFS on FreeBSD, I now and then I read messages that contain a reference to Illumos which certainly helps to kee

Sep 7, 20181h 3m

Episode 262: OpenBSD Surfacing | BSD Now 262

OpenBSD on Microsoft Surface Go, FreeBSD Foundation August Update, What’s taking so long with Project Trident, pkgsrc config file versioning, and MacOS remnants in ZFS code. ##Headlines ###OpenBSD on the Microsoft Surface Go For some reason I like small laptops and the constraints they place on me (as long as they’re still usable). I used a Dell Mini 9 for a long time back in the netbook days and was recently using an 11" MacBook Air as my primary development machine for many years. Recently Microsoft announced a smaller, cheaper version of its Surface tablets called Surface Go which piqued my interest. Hardware The Surface Go is available in two hardware configurations: one with 4Gb of RAM and a 64Gb eMMC, and another with 8Gb of RAM with a 128Gb NVMe SSD. (I went with the latter.) Both ship with an Intel Pentium Gold 4415Y processor which is not very fast, but it’s certainly usable. The tablet measures 9.65" across, 6.9" tall, and 0.3" thick. Its 10" diagonal 3:2 touchscreen is covered with Gorilla Glass and has a resolution of 1800x1200. The bezel is quite large, especially for such a small screen, but it makes sense on a device that is meant to be held, to avoid accidental screen touches. The keyboard and touchpad are located on a separate, removable slab called the Surface Go Signature Type Cover which is sold separately. I opted for the “cobalt blue” cover which has a soft, cloth-like alcantara material. The cover attaches magnetically along the bottom edge of the device and presents USB-attached keyboard and touchpad devices. When the cover is folded up against the screen, it sends an ACPI sleep signal and is held to the screen magnetically. During normal use, the cover can be positioned flat on a surface or slightly raised up about 3/4" near the screen for better ergonomics. When using the device as a tablet, the cover can be rotated behind the screen which causes it to automatically stop sending keyboard and touchpad events until it is rotated back around. The keyboard has a decent amount of key travel and a good layout, with Home/End/Page Up/Page Down being accessible via Fn+Left/Right/Up/Down but also dedicated Home/End/Page Up/Page Down keys on the F9-F12 keys which I find quite useful since the keyboard layout is somewhat small. By default, the F1-F12 keys do not send F1-F12 key codes and Fn must be used, either held down temporarily or Fn pressed by itself to enable Fn-lock which annoyingly keeps the bright Fn LED illuminated. The keys are backlit with three levels of adjustment, handled by the keyboard itself with the F7 key. The touchpad on the Type Cover is a Windows Precision Touchpad connected via USB HID. It has a decent click feel but when the cover is angled up instead of flat on a surface, it sounds a bit hollow and cheap. Surface Go Pen The touchscreen is powered by an Elantech chip connected via HID-over-i2c, which also supports pen input. A Surface Pen digitizer is available separately from Microsoft and comes in the same colors as the Type Covers. The pen works without any pairing necessary, though the top button on it works over Bluetooth so it requires pairing to use. Either way, the pen requires an AAAA battery inside it to operate. The Surface Pen can attach magnetically to the left side of the screen when not in use. A kickstand can swing out behind the display to use the tablet in a laptop form factor, which can adjust to any angle up to about 170 degrees. The kickstand stays firmly in place wherever it is positioned, which also means it requires a bit of force to pull it out when initially placing the Surface Go on a desk. Along the top of the display are a power button and physical volume rocker buttons. Along the right side are the 3.5mm headphone jack, USB-C port, power port, and microSD card slot located behind the kickstand. Charging can be done via USB-C or the dedicated charge port, which accommodates a magnetically-attached, thin barrel similar to Apple’s first generation MagSafe adapter. The charging cable has a white LED that glows when connected, which is kind of annoying since it’s near the mid-line of the screen rather than down by the keyboard. Unlike Apple’s MagSafe, the indicator light does not indicate whether the battery is charged or not. The barrel charger plug can be placed up or down, but in either direction I find it puts an awkward strain on the power cable coming out of it due to the vertical position of the port. Wireless connectivity is provided by a Qualcomm Atheros QCA6174 802.11ac chip which also provides Bluetooth connectivity. Most of the sensors on the device such as the gyroscope and ambient light sensor are connected behind an Intel Sensor Hub PCI device, which provides some power savings as the host CPU doesn’t have to poll the sensors all the time. Firmware The Surface Go’s BIOS/firmware menu can be entered by holding down the Volume Up button, then pressing and releasing the Power button, and releasing Volu

Sep 6, 20181h 13m

Episode 261: FreeBSDcon Flashback | BSD Now 261

Insight into TrueOS and Trident, stop evildoers with pf-badhost, Flashback to FreeBSDcon ‘99, OpenBSD’s measures against TLBleed, play Morrowind on OpenBSD in 5 steps, DragonflyBSD developers shocked at Threadripper performance, and more. ##Headlines ###An Insight into the Future of TrueOS BSD and Project Trident Last month, TrueOS announced that they would be spinning off their desktop offering. The team behind the new project, named Project Trident, have been working furiously towards their first release. They did take a few minutes to answer some of our question about Project Trident and TrueOS. I would like to thank JT and Ken for taking the time to compile these answers. It’s FOSS: What is Project Trident? Project Trident: Project Trident is the continuation of the TrueOS Desktop. Essentially, it is the continuation of the primary “TrueOS software” that people have been using for the past 2 years. The continuing evolution of the entire TrueOS project has reached a stage where it became necessary to reorganize the project. To understand this change, it is important to know the history of the TrueOS project. Originally, Kris Moore created PC-BSD. This was a Desktop release of FreeBSD focused on providing a simple and user-friendly graphical experience for FreeBSD. PC-BSD grew and matured over many years. During the evolution of PC-BSD, many users began asking for a server focused version of the software. Kris agreed, and TrueOS was born as a scaled down server version of PC-BSD. In late 2016, more contributors and growth resulted in significant changes to the PC-BSD codebase. Because the new development was so markedly different from the original PC-BSD design, it was decided to rebrand the project. TrueOS was chosen as the name for this new direction for PC-BSD as the project had grown beyond providing only a graphical front to FreeBSD and was beginning to make fundamental changes to the FreeBSD operating system. One of these changes was moving PC-BSD from being based on each FreeBSD Release to TrueOS being based on the active and less outdated FreeBSD Current. Other major changes are using OpenRC for service management and being more aggressive about addressing long-standing issues with the FreeBSD release process. TrueOS moved toward a rolling release cycle, twice a year, which tested and merged FreeBSD changes directly from the developer instead of waiting months or even years for the FreeBSD review process to finish. TrueOS also deprecated and removed obsolete technology much more regularly. As the TrueOS Project grew, the developers found these changes were needed by other FreeBSD-based projects. These projects began expressing interest in using TrueOS rather than FreeBSD as the base for their project. This demonstrated that TrueOS needed to again evolve into a distribution framework for any BSD project to use. This allows port maintainers and source developers from any BSD project to pool their resources and use the same source repositories while allowing every distribution to still customize, build, and release their own self-contained project. The result is a natural split of the traditional TrueOS team. There were now naturally two teams in the TrueOS project: those working on the build infrastructure and FreeBSD enhancements – the “core” part of the project, and those working on end-user experience and utility – the “desktop” part of the project. When the decision was made to formally split the projects, the obvious question that arose was what to call the “Desktop” project. As TrueOS was already positioned to be a BSD distribution platform, the developers agreed the desktop side should pick a new name. There were other considerations too, one notable being that we were concerned that if we continued to call the desktop project “TrueOS Desktop”, it would prevent people from considering TrueOS as the basis for their distribution because of misconceptions that TrueOS was a desktop-focused OS. It also helps to “level the playing field” for other desktop distributions like GhostBSD so that TrueOS is not viewed as having a single “blessed” desktop version. It’s FOSS: What features will TrueOS add to the FreeBSD base? Project Trident: TrueOS has already added a number of features to FreeBSD: OpenRC replaces rc.d for service management LibreSSL in base Root NSS certificates out-of-box Scriptable installations (pc-sysinstall) The full list of changes can be seen on the TrueOS repository (https://github.com/trueos/trueos/blob/trueos-master/README.md). This list does change quite regularly as FreeBSD development itself changes. It’s FOSS: I understand that TrueOS will have a new feature that will make creating a desktop spin of TrueOS very easy. Could you explain that new feature? Project Trident: Historically, one of the biggest hurdles for creating a desktop version of FreeBSD is that the build options for packages are tuned for servers rather than desktops. This means a desktop distribution cannot us

Aug 30, 20181h 49m

Episode 260: Hacking Tour of Europe | BSD Now 260

Trip reports from the Essen Hackathon and BSDCam, CfT: ZFS native encryption and UFS trim consolidation, ZFS performance benchmarks on a FreeBSD server, how to port your OS to EC2, Vint Cerf about traceability, Remote Access console to an RPi3 running FreeBSD, and more. ##Headlines ###Essen Hackathon & BSDCam 2018 trip report Allan and Benedict met at FRA airport and then headed to the Air Rail terminal for our train to Essen where the Hackathon would happen over the weekend of Aug 10 - 12, 2018. Once there, we did not have to wait long until other early-arrivals would show up and soon we had about 10 people gathered for lunch. After buying some take-out pizzas and bringing it back to the Linuxhotel (there was a training still going on there so we could not get into our rooms yet), we sat in the sunny park and talked. More and more people arrived and soon, people started hacking on their laptops. Some people would not arrive until a few hours before midnight, but we already had a record appearance of 20 people in total. On Saturday, we gathered everyone in one of the seminar rooms that had rooms and chairs for us. After some organizational infos, we did an introductory round and Benedict wrote down on the whiteboard what people were interested in. It was not long until groups formed to talk about SSL in base, weird ZFS scrubs that would go over 100% completion (fixed now). Other people started working on ports, fixing bugs, or wrote documentation. The day ended in a BBQ in the Linuxhotel park, which was well received by everyone. On Sunday, after attendees packed up their luggage and stored it in the seminar room, we continued hacking until lunchtime. After a quick group picture, we headed to a local restaurant for the social event (which was not open on Saturday, otherwise we would have had it then). In the afternoon, most people departed, a good half of them were heading for BSDCam. Commits from the hackathon (the ones from 2018) Overall, the hackathon was well received by attendees and a lot of them liked the fact that it was close to another BSD gathering so they could nicely combine the two. Also, people thought about doing their own hackathon in the future, which is an exciting prospect. Thanks to all who attended, helped out here and there when needed. Special Thanks to Netzkommune GmbH for sponsoring the social event and the Linuxhotel for having us. Benedict was having a regular work day on Monday after coming back from the hackathon, but flew out to Heathrow on Tuesday. Allan was in London a day earlier and arrived a couple of hours before Benedict in Cambridge. He headed for the Computer Lab even though the main event would not start until Wednesday. Most people gathered at the Maypole pub on Tuesday evening for welcomes, food and drinks. On Wednesday, a lot of people met in the breakfast room of Churchill College where most people were staying and went to the Computer Lab, which served as the main venue for BSDCam, together. The morning was spend with introductions and collecting what most people were interested in talking. This unconference style has worked well in the past and soon we had 10 main sessions together for the rest of this and the following two days (full schedule). Most sessions took notes, which you can find on the FreeBSD wiki. On Thursday evening, we had a nice formal dinner at Trinity Hall. BSDCam 2018 was a great success with a lot of fruitful discussions and planning sessions. We thank the organizers for BSDCam for making it happen. A special mentions goes out to Robert Watson and his family. Even though he was not there, he had a good reason to miss it: they had their first child born at the beginning of the week. Congratulations and best wishes to all three of them! ###Call for Testing: ZFS Native Encryption for FreeBSD A port of the ZoL (ZFS-on-Linux) feature that provides native crypto support for ZFS is ready for testing on FreeBSD Most of the porting was done by [email protected] (Sean Eric Fagan) The original ZoL commit is here: https://github.com/zfsonlinux/zfs/pull/5769/commits/5aef9bedc801830264428c64cd2242d1b786fd49 For an overview, see Tom Caputi’s presentation from the OpenZFS Developers Summit in 2016 Video: https://youtu.be/frnLiXclAMo Slides: https://drive.google.com/file/d/0B5hUzsxe4cdmU3ZTRXNxa2JIaDQ/view?usp=sharing WARNING: test in VMs or with spare disks etc, pools created with this code, or upgraded to this version, will no longer be importable on systems that do not support this feature. The on-disk format or other things may change before the final version, so you will likely have to ‘zfs send | zfs recv’ the data on to a new pool Thanks for testing to help this feature land in FreeBSD iXsystems ###Call for Testing: UFS TRIM Consolidation Kirk Mckusick posts to the FreeBSD mailing list looking for testers for the new UFS TRIM Consolidation code When deleting files on filesystems that are stored on flash-memory (solid-state) disk drives, the filesyst

Aug 23, 20181h 20m

Episode 259: Long Live Unix | BSD Now 259

The strange birth and long life of Unix, FreeBSD jail with a single public IP, EuroBSDcon 2018 talks and schedule, OpenBSD on G4 iBook, PAM template user, ZFS file server, and reflections on one year of OpenBSD use. Picking the contest winner Vincent Bostjan Andrew Klaus-Hendrik Will Toby Johnny David manfrom Niclas Gary Eddy Bruce Lizz Jim Random number generator ##Headlines ###The Strange Birth and Long Life of Unix They say that when one door closes on you, another opens. People generally offer this bit of wisdom just to lend some solace after a misfortune. But sometimes it’s actually true. It certainly was for Ken Thompson and the late Dennis Ritchie, two of the greats of 20th-century information technology, when they created the Unix operating system, now considered one of the most inspiring and influential pieces of software ever written. A door had slammed shut for Thompson and Ritchie in March of 1969, when their employer, the American Telephone & Telegraph Co., withdrew from a collaborative project with the Massachusetts Institute of Technology and General Electric to create an interactive time-sharing system called Multics, which stood for “Multiplexed Information and Computing Service.” Time-sharing, a technique that lets multiple people use a single computer simultaneously, had been invented only a decade earlier. Multics was to combine time-sharing with other technological advances of the era, allowing users to phone a computer from remote terminals and then read e-mail, edit documents, run calculations, and so forth. It was to be a great leap forward from the way computers were mostly being used, with people tediously preparing and submitting batch jobs on punch cards to be run one by one. Over five years, AT&T invested millions in the Multics project, purchasing a GE-645 mainframe computer and dedicating to the effort many of the top researchers at the company’s renowned Bell Telephone Laboratories—­including Thompson and Ritchie, Joseph F. Ossanna, Stuart Feldman, M. Douglas McIlroy, and the late Robert Morris. But the new system was too ambitious, and it fell troublingly behind schedule. In the end, AT&T’s corporate leaders decided to pull the plug. After AT&T’s departure from the Multics project, managers at Bell Labs, in Murray Hill, N.J., became reluctant to allow any further work on computer operating systems, leaving some researchers there very frustrated. Although Multics hadn’t met many of its objectives, it had, as Ritchie later recalled, provided them with a “convenient interactive computing service, a good environment in which to do programming, [and] a system around which a fellowship could form.” Suddenly, it was gone. With heavy hearts, the researchers returned to using their old batch system. At such an inauspicious moment, with management dead set against the idea, it surely would have seemed foolhardy to continue designing computer operating systems. But that’s exactly what Thompson, Ritchie, and many of their Bell Labs colleagues did. Now, some 40 years later, we should be thankful that these programmers ignored their bosses and continued their labor of love, which gave the world Unix, one of the greatest computer operating systems of all time. The rogue project began in earnest when Thompson, Ritchie, and a third Bell Labs colleague, Rudd Canaday, began to sketch out on paper the design for a file system. Thompson then wrote the basics of a new operating system for the lab’s GE-645 mainframe. But with the Multics project ended, so too was the need for the GE-645. Thompson realized that any further programming he did on it was likely to go nowhere, so he dropped the effort. Thompson had passed some of his time after the demise of Multics writing a computer game called Space Travel, which simulated all the major bodies in the solar system along with a spaceship that could fly around them. Written for the GE-645, Space Travel was clunky to play—and expensive: roughly US $75 a game for the CPU time. Hunting around, Thompson came across a dusty PDP-7, a minicomputer built by Digital Equipment Corp. that some of his Bell Labs colleagues had purchased earlier for a circuit-analysis project. Thompson rewrote Space Travel to run on it. And with that little programming exercise, a second door cracked ajar. It was to swing wide open during the summer of 1969 when Thompson’s wife, Bonnie, spent a month visiting his parents to show off their newborn son. Thompson took advantage of his temporary bachelor existence to write a good chunk of what would become the Unix operating system for the discarded PDP‑7. The name Unix stems from a joke one of Thompson’s colleagues made: Because the new operating system supported only one user (Thompson), he saw it as an emasculated version of Multics and dubbed it “Un-multiplexed Information and Computing Service,” or Unics. The name later morphed into Unix. Initially, Thompson used the GE-645 to compose and compile the software, which

Aug 16, 20181h 47m

Episode 258: OS Foundations | BSD Now 258

FreeBSD Foundation July Newsletter, a bunch of BSDCan trip reports, HardenedBSD Foundation status, FreeBSD and OSPFd, ZFS disk structure overview, and more Spectre mitigations in OpenBSD. ##Headlines ###FreeBSD Foundation Update, July 2018 MESSAGE FROM THE EXECUTIVE DIRECTOR We’re in the middle of summer here, in Boulder, CO. While the days are typically hot, they can also be quite unpredictable. Thanks to the Rocky Mountains, waking up to 50-degree (~10 C) foggy weather is not surprising. In spite of the unpredictable weather, many of us took some vacation this month. Whether it was extending the Fourth of July celebration, spending time with family, or relaxing and enjoying the summer weather, we appreciated our time off, while still managing to accomplish a lot! In this newsletter, Glen Barber enlightens us about the upcoming 12.0 release. I gave a recap of OSCON, that Ed Maste and I attended, and Mark Johnston explains the work on his improved microcode loading project, that we are funding. Finally, Anne Dickison gives us a rundown on upcoming events and information on submitting a talk for MeetBSD. Your support helps us continue this work. Please consider making a donation today. We can’t do it without you. Happy reading!! June 2018 Development Projects Update Fundraising Update: Supporting the Project July 2018 Release Engineering Update OSCON 2018 Recap Submit Your Work: MeetBSD 2018 FreeBSD Discount for 2018 SNIA Developer Conference EuroBSDcon 2018 Travel Grant Application Deadline: August 2 iXsystems ###BSDCan Trip Reports BSDCan 2018 Trip Report: Constantin Stan BSDCan 2018 Trip Report: Danilo G. Baio BSDCan 2018 Trip Report: Rodrigo Osorio BSDCan 2018 Trip Report: Dhananjay Balan BSDCan 2018 Trip Report: Kyle Evans ##News Roundup ###FreeBSD and OSPFd With FreeBSD jails deployed around the world, static routing was getting a bit out of hand. Plus, when I needed to move a jail from one data center to another, I would have to update routing tables across multiple sites. Not ideal. Enter dynamic routing… OSPF (open shortest path first) is an internal dynamic routing protocol that provides the autonomy that I needed and it’s fairly easy to setup. This article does not cover configuration of VPN links, ZFS, or Freebsd jails, however it’s recommended that you use seperate ZFS datasets per jail so that migration between hosts can be done with zfs send & receive. In this scenario, we have five FreeBSD servers in two different data centers. Each physical server runs anywhere between three to ten jails. When jails are deployed, they are assigned a /32 IP on lo2. From here, pf handles inbound port forwarding and outbound NAT. Links between each server are provided by OpenVPN TAP interfaces. (I used TAP to pass layer 2 traffic. I seem to remember that I needed TAP interfaces due to needing GRE tunnels on top of TUN interfaces to get OSPF to communicate. I’ve heard TAP is slower than TUN so I may revisit this.) In this example, we will use 172.16.2.0/24 as the range for OpenVPN P2P links and 172.16.3.0/24 as the range of IPs available for assignment to each jail. Previously, when deploying a jail, I assigned IPs based on the following groups: Server 1: 172.16.3.0/28 Server 2: 172.16.3.16/28 Server 3: 172.16.3.32/28 Server 4: 172.16.3.48/28 Server 5: 172.16.3.64/28 When statically routing, this made routing tables a bit smaller and easier to manage. However, when I needed to migrate a jail to a new host, I had to add a new /32 to all routing tables. Now, with OSPF, this is no longer an issue, nor is it required. To get started, first we install the Quagga package. The two configuration files needed to get OSPFv2 running are /usr/local/etc/quagga/zebra.conf and /usr/local/etc/quagga/ospfd.conf. Starting with zebra.conf, we’ll define the hostname and a management password. Second, we will populate the ospfd.conf file. To break this down: service advanced-vty allows you to skip the en or enable command. Since I’m the only one who uses this service, it’s one less command to type. ip ospf authentication message-digest and ip ospf message-diget-key… ignores non-authenticated OSPF communication. This is useful when communicating over the WAN and to prevent a replay attack. Since I’m using a VPN to communicate, I could exclude these. passive-interface default turns off the active communication of OSPF messages on all interfaces except for the interfaces listed as no passive-interface [interface name]. Since my ospf communication needs to leverage the VPNs, this prevents the servers from trying to send ospf data out the WAN interface (a firewall would work too). network 172.16.2.0/23 area 0.0.0.0 lists a supernet of both 172.16.2.0/24 and 172.16.3.0/24. This ensures routes for the jails are advertised along with the P2P links used by OpenVPN. The OpenVPN links are not required but can provide another IP to access your server if one of the links goes down. (See the suggested tasks below). At this point, we can enabl

Aug 8, 20181h 27m

Episode 257: Great NetBSD 8 | BSD Now 257

NetBSD 8.0 available, FreeBSD on Scaleway’s ARM64 VPS, encrypted backups with OpenBSD, Dragonfly server storage upgrade, zpool checkpoints, g2k18 hackathon reports, and more. ##Headlines ###NetBSD v8.0 Released The NetBSD Project is pleased to announce NetBSD 8.0, the sixteenth major release of the NetBSD operating system. This release brings stability improvements, hundreds of bug fixes, and many new features. Some highlights of the NetBSD 8.0 release are: USB stack rework, USB3 support added. In-kernel audio mixer (audio_system(9)). Reproducible builds (MKREPRO, see mk.conf(5)). Full userland debug information (MKDEBUG, see mk.conf(5)) available. While most install media do not come with them (for size reasons), the debug and xdebug sets can be downloaded and extracted as needed later. They provide full symbol information for all base system and X binaries and libraries and allow better error reporting and (userland) crash analysis. PaX MPROTECT (W^X) memory protection enforced by default on some architectures with fine-grained memory protection and suitable ELF formats: i386, amd64, evbarm, landisk. PaX ASLR (Address Space Layout Randomization) enabled by default on: i386, amd64, evbarm, landisk, sparc64. Position independent executables by default for userland on: i386, amd64, arm, m68k, mips, sh3, sparc64. A new socket layer can(4) has been added for communication of devices on a CAN bus. A special pseudo interface ipsecif(4) for route-based VPNs has been added. Parts of the network stack have been made MP-safe. The kernel option NET_MPSAFE is required to enable this. Hardening of the network stack in general. Various WAPBL (the NetBSD file system “log” option) stability and performance improvements. Specific to i386 and amd64 CPUs: Meltdown mitigation: SVS (Separate Virtual Space), enabled by default. SpectreV2 mitigation: retpoline (support in gcc), used by default for kernels. Other hardware mitigations are also available. SpectreV4 mitigations available for Intel and AMD. PopSS workaround: user access to debug registers is turned off by default. Lazy FPU saving disabled on vulnerable Intel CPUs (“eagerfpu”). SMAP support. Improvement and hardening of the memory layout: W^X, fewer writable pages, better consistency, better performance. (U)EFI bootloader. Many evbarm kernels now use FDT (flat device tree) information (loadable at boot time from an external file) for device configuration, the number of kernels has decreased but the number of boards has vastly increased. Lots of updates to 3rd party software included: GCC 5.5 with support for Address Sanitizer and Undefined Behavior Sanitizer GDB 7.12 GNU binutils 2.27 Clang/LLVM 3.8.1 OpenSSH 7.6 OpenSSL 1.0.2k mdocml 1.14.1 acpica 20170303 ntp 4.2.8p11-o dhcpcd 7.0.6 Lua 5.3.4 ###Running FreeBSD on the ARM64 VPS from Scaleway I’ve been thinking about this 6 since 2017, but only yesterday signed up for an account and played around with the ARM64 offering. Turns out it’s pretty great! KVM boots into UEFI, there’s a local VirtIO disk attached, no NBD junk required. So we can definitely run FreeBSD. I managed to “depenguinate” a running instance, the notes are below. Would be great if Scaleway offered an official image instead :wink: For some reason, unlike on x86 4, mounting additional volumes is not allowed 4 on ARM64 instances. So we’ll have to move the running Linux to a ramdisk using pivot_root and then we can do whatever to our one and only disk. Spin up an instance with Ubuntu Zesty and ssh in. Prepare the system and change the root to a tmpfs: apt install gdisk mount -t tmpfs tmpfs /tmp cp -r /bin /sbin /etc /dev /root /home /lib /run /usr /var /tmp mkdir /tmp/proc /tmp/sys /tmp/oldroot mount /dev/vda /tmp/oldroot mount --make-rprivate / pivot_root /tmp /tmp/oldroot for i in dev proc sys run; do mount --move /oldroot/$i /$i; done systemctl daemon-reload systemctl restart sshd Now reconnect to ssh from a second terminal (note: rm the connection file if you use ControlPersist in ssh config), then exit the old session. Kill the old sshd process, restart or stop the rest of the stuff using the old disk: pkill -f notty sed -ibak 's/RefuseManualStart.*$//g' /lib/systemd/system/dbus.service systemctl daemon-reload systemctl restart dbus systemctl daemon-reexec systemctl stop user@0 ntp cron systemd-logind systemctl restart systemd-journald systemd-udevd pkill agetty pkill rsyslogd Check that nothing is touching /oldroot: lsof | grep oldroot There will probably be an old dbus-daemon, kill it. And finally, unmount the old root and overwrite the hard disk with a memstick image: umount -R /oldroot wget https://download.freebsd.org/ftp/snapshots/arm64/aarch64/ISO-IMAGES/12.0/FreeBSD-12.0-CURRENT-arm64-aarch64-20180719-r336479-mini-memstick.img.xz xzcat FreeBSD-12.0-CURRENT-arm64-aarch64-20180719-r336479-mini-memstick.img.xz | dd if=/dev/stdin of=/dev/vda bs=1M (Look for the newest snapshot, don’t copy paste the July 19 link above if you’re reading this in th

Aug 2, 20181h 23m

Episode 256: Because Computers | BSD Now 2^8

FreeBSD ULE vs. Linux CFS, OpenBSD on Tuxedo InfinityBook, how zfs diff reports filenames efficiently, why choose FreeBSD over Linux, PS4 double free exploit, OpenBSD’s wifi autojoin, and FreeBSD jails the hard way. Win Celebrate our 256th episode with us. You can win a Mogics Power Bagel (not sponsored). To enter, go find the 4 episodes we did in December of 2017. In the opening, find the 4 letters in the bookshelf behind me. They spell different words in each of the 4 episodes. Send us these words in order to [email protected] with the subject “bsdnow256” until August 8th, 2018 18:00 UTC and we’ll randomly draw the winner on the live show. We’ll then contact you to ship the item. Only one item to win. All decisions are final. Better luck next time. Headlines Battle of the Schedulers: FreeBSD ULE vs. Linux CFS Introduction This paper analyzes the impact on application performance of the design and implementation choices made in two widely used open-source schedulers: ULE, the default FreeBSD scheduler, and CFS, the default Linux scheduler. We compare ULE and CFS in otherwise identical circumstances. We have ported ULE to Linux, and use it to schedule all threads that are normally scheduled by CFS. We compare the performance of a large suite of applications on the modified kernel running ULE and on the standard Linux kernel running CFS. The observed performance differences are solely the result of scheduling decisions, and do not reflect differences in other subsystems between FreeBSD and Linux. There is no overall winner. On many workloads the two schedulers perform similarly, but for some workloads there are significant and even surprising differences. ULE may cause starvation, even when executing a single application with identical threads, but this starvation may actually lead to better application performance for some workloads. The more complex load balancing mechanism of CFS reacts more quickly to workload changes, but ULE achieves better load balance in the long run. Operating system kernel schedulers are responsible for maintaining high utilization of hardware resources (CPU cores, memory, I/O devices) while providing fast response time to latency-sensitive applications. They have to react to workload changes, and handle large numbers of cores and threads with minimal overhead [12]. This paper provides a comparison between the default schedulers of two of the most widely deployed open-source operating systems: the Completely Fair Scheduler (CFS) used in Linux, and the ULE scheduler used in FreeBSD. Our goal is not to declare an overall winner. In fact, we find that for some workloads ULE is better and for others CFS is better. Instead, our goal is to illustrate how differences in the design and the implementation of the two schedulers are reflected in application performance under different workloads. ULE and CFS are both designed to schedule large numbers of threads on large multicore machines. Scalability considerations have led both schedulers to adopt per-core run-queues. On a context switch, a core accesses only its local run-queue to find the next thread to run. Periodically and at select times, e.g., when a thread wakes up, both ULE and CFS perform load balancing, i.e., they try to balance the amount of work waiting in the run-queues of different cores. ULE and CFS, however, differ greatly in their design and implementation choices. FreeBSD ULE is a simple scheduler (2,950 lines of code in FreeBSD 11.1), while Linux CFS is much more complex (17,900 lines of code in the latest LTS Linux kernel, Linux 4.9). FreeBSD run-queues are FIFO. For load balancing, FreeBSD strives to even out the number of threads per core. In Linux, a core decides which thread to run next based on prior execution time, priority, and perceived cache behavior of the threads in its runqueue. Instead of evening out the number of threads between cores, Linux strives to even out the average amount of pending work. Performance analysis We now analyze the impact of the per-core scheduling on the performance of 37 applications. We define “performance” as follows: for database workloads and NAS applications, we compare the number of operations per second, and for the other applications we compare “execution time”. The higher the “performance”, the better a scheduler performs. Figure 5 presents the performance difference between CFS and ULE on a single core, with percentages above 0 meaning that the application executes faster with ULE than CFS. Overall, the scheduler has little influence on most workloads. Indeed, most applications use threads that all perform the same work, thus both CFS and ULE endup scheduling all of the threads in a round-robin fashion. The average performance difference is 1.5%, in favor of ULE. Still, scimark is 36% slower on ULE than CFS, and apache is 40% faster on ULE than CFS. Scimark is a single-threaded Java application. It launches one compute thread, and the Java runtime executes other Java system

Jul 25, 20181h 44m

Episode 255: What Are You Pointing At | BSD Now 255

What ZFS blockpointers are, zero-day rewards offered, KDE on FreeBSD status, new FreeBSD core team, NetBSD WiFi refresh, poor man’s CI, and the power of Ctrl+T. ##Headlines ###What ZFS block pointers are and what’s in them I’ve mentioned ZFS block pointers in the past; for example, when I wrote about some details of ZFS DVAs, I said that DVAs are embedded in block pointers. But I’ve never really looked carefully at what is in block pointers and what that means and implies for ZFS. The very simple way to describe a ZFS block pointer is that it’s what ZFS uses in places where other filesystems would simply put a block number. Just like block numbers but unlike things like ZFS dnodes, a block pointer isn’t a separate on-disk entity; instead it’s an on disk data format and an in memory structure that shows up in other things. To quote from the (draft and old) ZFS on-disk specification (PDF): A block pointer (blkptr_t) is a 128 byte ZFS structure used to physically locate, verify, and describe blocks of data on disk. Block pointers are embedded in any ZFS on disk structure that points directly to other disk blocks, both for data and metadata. For instance, the dnode for a file contains block pointers that refer to either its data blocks (if it’s small enough) or indirect blocks, as I saw in this entry. However, as I discovered when I paid attention, most things in ZFS only point to dnodes indirectly, by giving their object number (either in a ZFS filesystem or in pool-wide metadata). So what’s in a block pointer itself? You can find the technical details for modern ZFS in spa.h, so I’m going to give a sort of summary. A regular block pointer contains: various metadata and flags about what the block pointer is for and what parts of it mean, including what type of object it points to. Up to three DVAs that say where to actually find the data on disk. There can be more than one DVA because you may have set the copies property to 2 or 3, or this may be metadata (which normally has two copies and may have more for sufficiently important metadata). The logical size (size before compression) and ‘physical’ size (the nominal size after compression) of the disk block. The physical size can do odd things and is not necessarily the asize (allocated size) for the DVA(s). The txgs that the block was born in, both logically and physically (the physical txg is apparently for dva[0]). The physical txg was added with ZFS deduplication but apparently also shows up in vdev removal. The checksum of the data the block pointer describes. This checksum implicitly covers the entire logical size of the data, and as a result you must read all of the data in order to verify it. This can be an issue on raidz vdevs or if the block had to use gang blocks. Just like basically everything else in ZFS, block pointers don’t have an explicit checksum of their contents. Instead they’re implicitly covered by the checksum of whatever they’re embedded in; the block pointers in a dnode are covered by the overall checksum of the dnode, for example. Block pointers must include a checksum for the data they point to because such data is ‘out of line’ for the containing object. (The block pointers in a dnode don’t necessarily point straight to data. If there’s more than a bit of data in whatever the dnode covers, the dnode’s block pointers will instead point to some level of indirect block, which itself has some number of block pointers.) There is a special type of block pointer called an embedded block pointer. Embedded block pointers directly contain up to 112 bytes of data; apart from the data, they contain only the metadata fields and a logical birth txg. As with conventional block pointers, this data is implicitly covered by the checksum of the containing object. Since block pointers directly contain the address of things on disk (in the form of DVAs), they have to change any time that address changes, which means any time ZFS does its copy on write thing. This forces a change in whatever contains the block pointer, which in turn ripples up to another block pointer (whatever points to said containing thing), and so on until we eventually reach the Meta Object Set and the uberblock. How this works is a bit complicated, but ZFS is designed to generally make this a relatively shallow change with not many levels of things involved (as I discovered recently). As far as I understand things, the logical birth txg of a block pointer is the transaction group in which the block pointer was allocated. Because of ZFS’s copy on write principle, this means that nothing underneath the block pointer has been updated or changed since that txg; if something changed, it would have been written to a new place on disk, which would have forced a change in at least one DVA and thus a ripple of updates that would update the logical birth txg. However, this doesn’t quite mean what I used to think it meant because of ZFS’s level of indirection. If you change a file by writing d

Jul 18, 20181h 20m

Episode 254: Bare the OS | BSD Now 254

Control flow integrity with HardenedBSD, fixing bufferbloat with OpenBSD’s pf, Bareos Backup Server on FreeBSD, MeetBSD CfP, crypto simplified interface, twitter gems, interesting BSD commits, and more. ##Headlines ###Silent Fanless FreeBSD Desktop/Server Today I will write about silent fanless FreeBSD desktop or server computer … or NAS … or you name it, it can have multa##Headlines ###Cross-DSO CFI in HardenedBSD Control Flow Integrity, or CFI, raises the bar for attackers aiming to hijack control flow and execute arbitrary code. The llvm compiler toolchain, included and used by default in HardenedBSD 12-CURRENT/amd64, supports forward-edge CFI. Backward-edge CFI support is gained via a tangential feature called SafeStack. Cross-DSO CFI builds upon ASLR and PaX NOEXEC for effectiveness. HardenedBSD supports non-Cross-DSO CFI in base for 12-CURRENT/amd64 and has it enabled for a few individual ports. The term “non-Cross-DSO CFI” means that CFI is enabled for code within an application’s codebase, but not for the shared libraries it depends on. Supporting non-Cross-DSO CFI is an important initial milestone for supporting Cross-DSO CFI, or CFI applied to both shared libraries and applications. This article discusses where HardenedBSD stands with regards to Cross-DSO CFI in base. We have made a lot of progress, yet we’re not even half-way there. Brace yourself: This article is going to be full of references to “Cross-DSO CFI.” Make a drinking game out of it. Or don’t. It’s your call. ;) Using More llvm Toolchain Components CFI requires compiling source files with Link-Time Optimization (LTO). I remembered hearing a few years back that llvm developers were able to compile the entirety of FreeBSD’s source code with LTO. Compiling with LTO produces intermediate object files as LLVM IR bitcode instead of ELF objects. In March of 2017, we started compiling all applications with LTO and non-Cross-DSO CFI. This also enabled ld.lld as the default linker in base since CFI requires lld. Commit f38b51668efcd53b8146789010611a4632cafade made the switch to ld.lld as the default linker while enabling non-Cross-DSO CFI at the same time. Building libraries in base requires applications like ar, ranlib, nm, and objdump. In FreeBSD 12-CURRENT, ar and ranlib are known as “BSD ar” and “BSD ranlib.” In fact, ar and ranlib are the same applications. One is hardlinked to another and the application changes behavior depending on arvgv[0] ending in “ranlib”. The ar, nm, and objdump used in FreeBSD do not support LLVM IR bitcode object files. In preparation for Cross-DSO CFI support, commit fe4bb0104fc75c7216a6dafe2d7db0e3f5fe8257 in October 2017 saw HardenedBSD switching ar, ranlib, nm, and objdump to their respective llvm components. The llvm versions due support LLVM IR bitcode object files (surprise!) There has been some fallout in the ports tree and we’ve added LLVM_AR_UNSAFE and friends to help transition those ports that dislike llvm-ar, llvm-ranlib, llvm-nm, and llvm-objdump. With ld.lld, llvm-ar, llvm-ranlib, llvm-nm, and llvm-objdump the default, HardenedBSD has effectively switched to a full llvm compiler toolchain in 12-CURRENT/amd64. Building Libraries With LTO The primary 12-CURRENT development branch in HardenedBSD (hardened/current/master) only builds applications with LTO as mentioned in the secion above. My first attempt at building all static and shared libraries failed due to issues within llvm itself. I reported these issues to FreeBSD. Ed Maste (emaste@), Dimitry Andric (dim@), and llvm’s Rafael Espindola expertly helped address these issues. Various commits within the llvm project by Rafael fully and quickly resolved the issues brought up privately in emails. With llvm fixed, I could now build nearly every library in base with LTO. I noticed, however, that if I kept non-Cross-DSO CFI and SafeStack enabled, all applications would segfault. Even simplistic applications like /bin/ls. Disabling both non-Cross-DSO CFI and SafeStack, but keeping LTO produced a fully functioning world! I have spent the last few months figuring out why enabling either non-Cross-DSO CFI or SafeStack caused issues. This brings us to today. The Sanitizers in FreeBSD FreeBSD brought in all the files required for SafeStack and CFI. When compiling with SafeStack, llvm statically links a full sanitization framework into the application. FreeBSD includes a full copy of the sanitization framework in SafeStack, including the common C++ sanization namespaces. Thus, libclang_rt.safestack included code meant to be shared among all the sanitizers, not just SafeStack. I had naively taken a brute-force approach to setting up the libclang_rt.cfi static library. I copied the Makefile from libclang_rt.safestack and used that as a template for libclang_rt.cfi. This approach was incorrect due to breaking the One Definition Rule (ODR). Essentially, I ended up including a duplicate copy of the C++ classes and sanitizer runtime if both CFI and SafeStack were us

Jul 12, 20181h 31m

Episode 253: Silence of the Fans | BSD Now 253

Fanless server setup with FreeBSD, NetBSD on pinebooks, another BSDCan trip report, transparent network audio, MirBSD's Korn Shell on Plan9, static site generators on OpenBSD, and more. ##Headlines ###Silent Fanless FreeBSD Desktop/Server Today I will write about silent fanless FreeBSD desktop or server computer … or NAS … or you name it, it can have multiple purposes. It also very low power solution, which also means that it will not overheat. Silent means no fans at all, even for the PSU. The format of the system should also be brought to minimum, so Mini-ITX seems best solution here. I have chosen Intel based solutions as they are very low power (6-10W), if you prefer AMD (as I often do) the closest solution in comparable price and power is Biostar A68N-2100 motherboard with AMD E1-2100 CPU and 9W power. Of course AMD has even more low power SoC solutions but finding the Mini-ITX motherboard with decent price is not an easy task. For comparison Intel has lots of such solutions below 6W whose can be nicely filtered on the ark.intel.com page. Pity that AMD does not provide such filtration for their products. I also chosen AES instructions as storage encryption (GELI on FreeBSD) today seems as obvious as HTTPS for the web pages. Here is how the system look powered up and working This motherboard uses Intel J3355 SoC which uses 10W and has AES instructions. It has two cores at your disposal but it also supports VT-x and EPT extensions so you can even run Bhyve on it. Components Now, an example system would look like that one below, here are the components with their prices. $49 CPU/Motherboard ASRock J3355B-ITX Mini-ITX $14 RAM Crucial 4 GB DDR3L 1.35V (low power) $17 PSU 12V 160W Pico (internal) $11 PSU 12V 96W FSP (external) $5 USB 2.0 Drive 16 GB ADATA $4 USB Wireless 802.11n $100 TOTAL The PSU 12V 160W Pico (internal) and PSU 12V 96W FSP can be purchased on aliexpress.com or ebay.com for example, at least I got them there. Here is the 12V 160W Pico (internal) PSU and its optional additional cables to power the optional HDDs. If course its one SATA power and one MOLEX power so additional MOLEX-SATA power adapter for about 1$ would be needed. Here is the 12V 96W FSP (external) PSU without the power cord. This gives as total silent fanless system price of about $120. Its about ONE TENTH OF THE COST of the cheapest FreeNAS hardware solution available – the FreeNAS Mini (Diskless) costs $1156 also without disks. You can put plain FreeBSD on top of it or Solaris/Illumos distribution OmniOSce which is server oriented. You can use prebuilt NAS solution based on FreeBSD like FreeNAS, NAS4Free, ZFSguru or even Solaris/Illumos based storage with napp-it appliance. ###An annotated look at a NetBSD Pinebook’s startup Pinebook is an affordable 64-bit ARM notebook. Today we’re going to take a look at the kernel output at startup and talk about what hardware support is available on NetBSD. Photo Pinebook comes with 2GB RAM standard. A small amount of this is reserved by the kernel and framebuffer. NetBSD uses flattened device-tree (FDT) to enumerate devices on all Allwinner based SoCs. On a running system, you can inspect the device tree using the ofctl(8) utility: Pinebook’s Allwinner A64 processor is based on the ARM Cortex-A53. It is designed to run at frequencies up to 1.2GHz. The A64 is a quad core design. NetBSD’s aarch64 pmap does not yet support SMP, so three cores are disabled for now. The interrupt controller is a standard ARM GIC-400 design. Clock drivers for managing PLLs, module clock dividers, clock gating, software resets, etc. Information about the clock tree is exported in the hw.clk sysctl namespace (root access required to read these values). # sysctl hw.clk.sun50ia64ccu0.mmc2 hw.clk.sun50ia64ccu0.mmc2.rate = 200000000 hw.clk.sun50ia64ccu0.mmc2.parent = pll_periph0_2x hw.clk.sun50ia64ccu0.mmc2.parent_domain = sun50ia64ccu0 Digital Ocean http://do.co/bsdnow ###BSDCan 2018 Trip Report: Mark Johnston BSDCan is a highlight of my summers: the ability to have face-to-face conversations with fellow developers and contributors is invaluable and always helps refresh my enthusiasm for FreeBSD. While in a perfect world we would all be able to communicate effectively over the Internet, it’s often noted that locking a group of developers together in a room can be a very efficient way to make progress on projects that otherwise get strung out over time, and to me this is one of the principal functions of BSD conferences. In my case I was able to fix some kgdb bugs that had been hindering me for months; get some opinions on the design of a feature I’ve been working on for FreeBSD 12.0; hear about some ongoing usage of code that I’ve worked on; and do some pair-debugging of an issue that has been affecting another developer. As is tradition, on Tuesday night I dropped off my things at the university residence where I was staying, and headed straight to the Royal Oak. This year it didn’t seem quite as packed with

Jul 5, 20181h 26m

Episode 252: Goes to 11.2 | BSD Now 252

FreeBSD 11.2 has been released, setting up an MTA behind Tor, running pfsense on DigitalOcean, one year of C, using OpenBGPD to announce VM networks, the power to serve, and a BSDCan trip report. ##Headlines ###FreeBSD 11.2-RELEASE Available FreeBSD 11.2 was released today (June 27th) and is ready for download Highlights: OpenSSH has been updated to version 7.5p1. OpenSSL has been updated to version 1.0.2o. The clang, llvm, lldb and compiler-rt utilities have been updated to version 6.0.0. The libarchive(3) library has been updated to version 3.3.2. The libxo(3) library has been updated to version 0.9.0. Major Device driver updates to: cxgbe(4) – Chelsio 10/25/40/50/100 gigabit NICs – version 1.16.63.0 supports T4, T5 and T6 ixl(4) – Intel 10 and 40 gigabit NICs, updated to version 1.9.9-k ng_pppoe(4) – driver has been updated to add support for user-supplied Host-Uniq tags New drivers: + drm-next-kmod driver supporting integrated Intel graphics with the i915 driver. mlx5io(4) – a new IOCTL interface for Mellanox ConnectX-4 and ConnectX-5 10/20/25/40/50/56/100 gigabit NICs ocs_fc(4) – Emulex Fibre Channel 8/16/32 gigabit Host Adapters smartpqi(4) – HP Gen10 Smart Array Controller Family The newsyslog(8) utility has been updated to support RFC5424-compliant messages when rotating system logs The diskinfo(8) utility has been updated to include two new flags, -s which displays the disk identity (usually the serial number), and -p which displays the physical path to the disk in a storage controller. The top(1) utility has been updated to allow filtering on multiple user names when the -U flag is used The umount(8) utility has been updated to include a new flag, -N, which is used to forcefully unmount an NFS mounted filesystem. The ps(1) utility has been updated to display if a process is running with capsicum(4) capability mode, indicated by the flag ‘C’ The service(8) utility has been updated to include a new flag, -j, which is used to interact with services running within a jail(8). The argument to -j can be either the name or numeric jail ID The mlx5tool(8) utility has been added, which is used to manage Connect-X 4 and Connect-X 5 devices supported by mlx5io(4). The ifconfig(8) utility has been updated to include a random option, which when used with the ether option, generates a random MAC address for an interface. The dwatch(1) utility has been introduced The efibootmgr(8) utility has been added, which is used to manipulate the EFI boot manager. The etdump(1) utility has been added, which is used to view El Torito boot catalog information. The linux(4) ABI compatibility layer has been updated to include support for musl consumers. The fdescfs(5) filesystem has been updated to support Linux®-specific fd(4) /dev/fd and /proc/self/fd behavior Support for virtio_console(4) has been added to bhyve(4). The length of GELI passphrases entered when booting a system with encrypted disks is now hidden by default. See the configuration options in geli(8) to restore the previous behavior. In addition to the usual CD/DVD ISO, Memstick, and prebuilt VM images (raw, qcow2, vhd, and vmdk), FreeBSD 11.2 is also available on: Amazon EC2 Google Compute Engine Hashicorp/Atlas Vagrant Microsoft Azure In addition to a generic ARM64 image for devices like the Pine64 and Raspberry Pi 3, specific images are provided for: GUMSTIX BANANAPI BEAGLEBONE CUBIEBOARD CUBIEBOARD2 CUBOX-HUMMINGBOARD RASPBERRY PI 2 PANDABOARD WANDBOARD Full Release Notes ###Setting up an MTA Behind Tor This article will document how to set up OpenSMTPD behind a fully Tor-ified network. Given that Tor’s DNS resolver code does not support MX record lookups, care must be taken for setting up an MTA behind a fully Tor-ified network. OpenSMTPD was chosen because it was easy to modify to force it to fall back to A/AAAA lookups when MX lookups failed with a DNS result code of NOTIMP (4). Note that as of 08 May 2018, the OpenSMTPD project is planning a configuration file language change. The proposed change has not landed. Once it does, this article will be updated to reflect both the old language and new. The reason to use an MTA behing a fully Tor-ified network is to be able to support email behind the .onion TLD. This setup will only allow us to send and receive email to and from the .onion TLD. Requirements: A fully Tor-ified network HardenedBSD as the operating system A server (or VM) running HardenedBSD behind the fully Tor-ified network. /usr/ports is empty Or is already pre-populated with the HardenedBSD Ports tree Why use HardenedBSD? We get all the features of FreeBSD (ZFS, DTrace, bhyve, and jails) with enhanced security through exploit mitigations and system hardening. Tor has a very unique threat landscape and using a hardened ecosystem is crucial to mitigating risks and threats. Also note that this article reflects how I’ve set up my MTA. I’ve included configuration files verbatim. You will need to replace the text that refers to my .onion domain with

Jun 28, 20181h 34m

Episode 251: Crypto HAMMER | BSD Now 251

DragonflyBSD’s hammer1 encrypted master/slave setup, second part of our BSDCan recap, NomadBSD 1.1-RC1 available, OpenBSD adds an LDAP client to base, FreeBSD gets pNFS support, Intel FPU Speculation Vulnerability confirmed, and what some Unix command names mean. ##Headlines ###DragonflyBSD: Towards a HAMMER1 master/slave encrypted setup with LUKS I just wanted to share my experience with setting up DragonFly master/slave HAMMER1 PFS’s on top of LUKS So after a long time using an Synology for my NFS needs, I decided it was time to rethink my setup a little since I had several issues with it : You cannot run NFS on top of encrypted partitions easily I suspect I am having some some data corruption (bitrot) on the ext4 filesystem the NIC was stcuk to 100 Mbps instead of 1 Gbps even after swapping cables, switches, you name it It’s proprietary I have been playing with DragonFly in the past and knew about HAMMER, now I just had the perfect excuse to actually use it in production :) After setting up the OS, creating the LUKS partition and HAMMER FS was easy : kdload dm cryptsetup luksFormat /dev/serno/<id1> cryptsetup luksOpen /dev/serno/<id1> fort_knox newfs_hammer -L hammer1_secure_master /dev/mapper/fort_knox cryptsetup luksFormat /dev/serno/<id2> cryptsetup luksOpen /dev/serno/<id2> fort_knox_slave newfs_hammer -L hammer1_secure_slave /dev/mapper/fort_knox_slave Mount the 2 drives : mount /dev/mapper/fort_knox /fort_knox mount /dev/mapper_fort_know_slave /fort_knox_slave You can now put your data under /fort_knox Now, off to setting up the replication, first get the shared-uuid of /fort_knox hammer pfs-status /fort_knox Create a PFS slave “linked” to the master hammer pfs-slave /fort_knox_slave/pfs/slave shared-uuid=f9e7cc0d-eb59-10e3-a5b5-01e6e7cefc12 And then stream your data to the slave PFS ! hammer mirror-stream /fort_knox /fort_knox_slave/pfs/slave After that, setting NFS is fairly trivial even though I had problem with the /etc/exports syntax which is different than Linux There’s a few things I wish would be better though but nothing too problematic or without workarounds : Cannot unlock LUKS partitions at boot time afaik (Acceptable tradeoff for the added security LUKS gives me vs my old Synology setup) but this force me to run a script to unlock LUKS, mount hammer and start mirror-stream at each boot No S1/S3 sleep so I made a script to shutdown the system when there’s no network neighborgs to serve the NFS As my system isn’t online 24/7 for energy reasons, I guess will have to run hammer cleanup myself from time to time Some uncertainty because hey, it’s kind of exotic but exciting too :) Overall, I am happy, HAMMER1 and PFS are looking really good, DragonFly is a neat Unix and the community is super friendly (Matthew Dillon actually provided me with a kernel patch to fix the broken ACPI on the PC holding this setup, many thanks!), the system is still a “work in progress” but it is already serving my files as I write this post. Let’s see in 6 months how it goes in the longer run ! Helpful resources : https://www.dragonflybsd.org/docs/how_to_implement_hammer_pseudo_file_system__40___pfs___41___slave_mirroring_from_pfs_master/ ###BSDCan 2018 Recap As promised, here is our second part of our BSDCan report, covering the conference proper. The last tutorials/devsummit of that day lead directly into the conference, as people could pick up their registration packs at the Red Lion and have a drink with fellow BSD folks. Allan and I were there only briefly, as we wanted to get back to the “Newcomers orientation and mentorship” session lead by Michael W. Lucas. This session is intended for people that are new to BSDCan (maybe their first BSD conference ever?) and may have questions. Michael explained everything from the 6-2-1 rule (hours of sleep, meals per day, and number of showers that attendees should have at a minimum), to the partner and widowers program (lead by his wife Liz), to the sessions that people should not miss (opening, closing, and hallway track). Old-time BSDCan folks were asked to stand up so that people can recognize them and ask them any questions they might have during the conferences. The session was well attended. Afterwards, people went for dinner in groups, a big one lead by Michael Lucas to his favorite Shawarma place, followed by gelato (of course). This allowed newbies to mingle over dinner and ice cream, creating a welcoming atmosphere. The next day, after Dan Langille opened the conference, Benno Rice gave the keynote presentation about “The Tragedy of Systemd”. Benedict went to the following talks: “Automating Network Infrastructures with Ansible on FreeBSD” in the DevSummit track. A good talk that connected well with his Ansible tutorial and even allowed some discussions among participants. “All along the dwatch tower”: Devin delivered a well prepared talk. I first thought that the number of slides would not fit into the time slot, but she even managed

Jun 21, 20181h 28m

Episode 250: BSDCan 2018 Recap | BSD Now 250

TrueOS becoming a downstream fork with Trident, our BSDCan 2018 recap, HardenedBSD Foundation founding efforts, VPN with OpenIKED on OpenBSD, FreeBSD on a System76 Galago Pro, and hardware accelerated crypto on Octeons. ##Headlines## ###TrueOS to Focus on Core Operating System The TrueOS Project has some big plans in the works, and we want to take a minute and share them with you. Many have come to know TrueOS as the “graphical FreeBSD” that makes things easy for newcomers to the BSDs. Today we’re announcing that TrueOS is shifting our focus a bit to become a cutting-edge operating system that keeps all of the stability that you know and love from ZFS (OpenZFS) and FreeBSD, and adds additional features to create a fresh, innovative operating system. Our goal is to create a core-centric operating system that is modular, functional, and perfect for do-it-yourselfers and advanced users alike. TrueOS will become a downstream fork that will build on FreeBSD by integrating new software technologies like OpenRC and LibreSSL. Work has already begun which allows TrueOS to be used as a base platform for other projects, including JSON-based manifests, integrated Poudriere / pkg tools and much more. We’re planning on a six month release cycle to keep development moving and fresh, allowing us to bring you hot new features to ZFS, bhyve and related tools in a timely manner. This makes TrueOS the perfect fit to serve as the basis for building other distributions. Some of you are probably asking yourselves “But what if I want to have a graphical desktop?” Don’t worry! We’re making sure that everyone who knows and loves the legacy desktop version of TrueOS will be able to continue using a FreeBSD-based, graphical operating system in the future. For instance, if you want to add KDE, just use sudo pkg install kde and voila! You have your new shiny desktop. Easy right? This allows us to get back to our roots of being a desktop agnostic operating system. If you want to add a new desktop environment, you get to pick the one that best suits your use. We know that some of you will still be looking for an out-of-the-box solution similar to legacy PC-BSD and TrueOS. We’re happy to announce that Project Trident will take over graphical FreeBSD development going forward. Not much is going to change in that regard other than a new name! You’ll still have Lumina Desktop as a lightweight and feature-rich desktop environment and tons of utilities from the legacy TrueOS toolchain like sysadm and AppCafe. There will be migration paths available for those that would like to move to other FreeBSD-based distributions like Project Trident or GhostBSD. We look forward to this new chapter for TrueOS and hope you will give the new edition a spin! Tell us what you think about the new changes by leaving us a comment. Don’t forget you can ask us questions on our Twitter and be a part of our community by joining the new TrueOS Forums when they go live in about a week. Thanks for being a loyal fan of TrueOS. ###Project Trident FAQ Q: Why did you pick the name “Project Trident”? A: We were looking for a name that was unique, yet would still relate to the BSD community. Since Beastie (the FreeBSD mascot) is always pictured with a trident, it felt like that would be a great name. Q: Where can users go for technical support? A: At the moment, Project Trident will continue sharing the TrueOS community forums and Telegram channels. We are currently evaluating dedicated options for support channels in the future. Q: Can I help contribute to the project? A: We are always looking for developers who want to join the project. If you’re not a developer you can still help, as a community project we will be more reliant on contributions from the community in the form of how-to guides and other user-centric documentation and support systems. Q: How is the project supported financially? A: Project Trident is sponsored by the community, from both individuals and corporations. iXsystems has stepped up as the first enterprise-level sponsor of the project, and has been instrumental in getting Project Trident up and running. Please visit the Sponsors page to see all the current sponsors. Q: How can I help support the project financially? A: Several methods exist, from one time or recurring donations via Paypal to limited time swag t-shirt campaigns during the year. We are also looking into more alternative methods of support, so please visit the Sponsors page to see all the current methods of sponsorship. Q: Will there be any transparency of the financial donations and expenditures? A: Yes, we will be totally open with how much money comes into the project and what it is spent on. Due to concerns of privacy, we will not identify individuals and their donation amounts unless they specifically request to be identified. We will release a monthly overview in/out ledger, so that community members can see where their money is going. Relationship with TrueOS Project Trident does

Jun 14, 20181h 41m

Episode 249: Router On A Stick | BSD Now 249

OpenZFS and DTrace updates in NetBSD, NetBSD network security stack audit, Performance of MySQL on ZFS, OpenSMTP results from p2k18, legacy Windows backup to FreeNAS, ZFS block size importance, and NetBSD as router on a stick. ##Headlines ###ZFS and DTrace update lands in NetBSD merge a new version of the CDDL dtrace and ZFS code. This changes the upstream vendor from OpenSolaris to FreeBSD, and this version is based on FreeBSD svn r315983. r315983 is from March 2017 (14 months ago), so there is still more work to do in addition to the 10 years of improvements from upstream, this version also has these NetBSD-specific enhancements: dtrace FBT probes can now be placed in kernel modules. ZFS now supports mmap(). This brings NetBSD 10 years forward, and they should be able to catch the rest of the way up fairly quickly ###NetBSD network stack security audit Maxime Villard has been working on an audit of the NetBSD network stack, a project sponsored by The NetBSD Foundation, which has served all users of BSD-derived operating systems. Over the last five months, hundreds of patches were committed to the source tree as a result of this work. Dozens of bugs were fixed, among which a good number of actual, remotely-triggerable vulnerabilities. Changes were made to strengthen the networking subsystems and improve code quality: reinforce the mbuf API, add many KASSERTs to enforce assumptions, simplify packet handling, and verify compliance with RFCs. This was done in several layers of the NetBSD kernel, from device drivers to L4 handlers. In the course of investigating several bugs discovered in NetBSD, I happened to look at the network stacks of other operating systems, to see whether they had already fixed the issues, and if so how. Needless to say, I found bugs there too. A lot of code is shared between the BSDs, so it is especially helpful when one finds a bug, to check the other BSDs and share the fix. The IPv6 Buffer Overflow: The overflow allowed an attacker to write one byte of packet-controlled data into ‘packet_storage+off’, where ‘off’ could be approximately controlled too. This allowed at least a pretty bad remote DoS/Crash The IPsec Infinite Loop: When receiving an IPv6-AH packet, the IPsec entry point was not correctly computing the length of the IPv6 suboptions, and this, before authentication. As a result, a specially-crafted IPv6 packet could trigger an infinite loop in the kernel (making it unresponsive). In addition this flaw allowed a limited buffer overflow - where the data being written was however not controllable by the attacker. The IPPROTO Typo: While looking at the IPv6 Multicast code, I stumbled across a pretty simple yet pretty bad mistake: at one point the Pim6 entry point would return IPPROTO_NONE instead of IPPROTO_DONE. Returning IPPROTO_NONE was entirely wrong: it caused the kernel to keep iterating on the IPv6 packet chain, while the packet storage was already freed. The PF Signedness Bug: A bug was found in NetBSD’s implementation of the PF firewall, that did not affect the other BSDs. In the initial PF code a particular macro was used as an alias to a number. This macro formed a signed integer. NetBSD replaced the macro with a sizeof(), which returns an unsigned result. The NPF Integer Overflow: An integer overflow could be triggered in NPF, when parsing an IPv6 packet with large options. This could cause NPF to look for the L4 payload at the wrong offset within the packet, and it allowed an attacker to bypass any L4 filtering rule on IPv6. The IPsec Fragment Attack: I noticed some time ago that when reassembling fragments (in either IPv4 or IPv6), the kernel was not removing the M_PKTHDR flag on the secondary mbufs in mbuf chains. This flag is supposed to indicate that a given mbuf is the head of the chain it forms; having the flag on secondary mbufs was suspicious. What Now: Not all protocols and layers of the network stack were verified, because of time constraints, and also because of unexpected events: the recent x86 CPU bugs, which I was the only one able to fix promptly. A todo list will be left when the project end date is reached, for someone else to pick up. Me perhaps, later this year? We’ll see. This security audit of NetBSD’s network stack is sponsored by The NetBSD Foundation, and serves all users of BSD-derived operating systems. The NetBSD Foundation is a non-profit organization, and welcomes any donations that help continue funding projects of this kind. DigitalOcean ###MySQL on ZFS Performance I used sysbench to create a table of 10M rows and then, using export/import tablespace, I copied it 329 times. I ended up with 330 tables for a total size of about 850GB. The dataset generated by sysbench is not very compressible, so I used lz4 compression in ZFS. For the other ZFS settings, I used what can be found in my earlier ZFS posts but with the ARC size limited to 1GB. I then used that plain configuration for the first benchmarks. Here are the results with the sysbe

Jun 6, 20181h 25m

Episode 248: Show Me The Mooney | BSD Now 248

DragonflyBSD release 5.2.1 is here, BPF kernel exploit writeup, Remote Debugging the running OpenBSD kernel, interview with Patrick Mooney, FreeBSD buildbot setup in a jail, dumping your USB, and 5 years of gaming on FreeBSD. Headlines DragonFlyBSD: release52 (w/stable HAMMER2, as default root) DragonflyBSD 5.2.1 was released on May 21, 2018 > Big Ticket items: Meltdown and Spectre mitigation support Meltdown isolation and spectre mitigation support added. Meltdown mitigation is automatically enabled for all Intel cpus. Spectre mitigation must be enabled manually via sysctl if desired, using sysctls machdep.spectremitigation and machdep.meltdownmitigation. HAMMER2 H2 has received a very large number of bug fixes and performance improvements. We can now recommend H2 as the default root filesystem in non-clustered mode. Clustered support is not yet available. ipfw Updates Implement state based "redirect", i.e. without using libalias. ipfw now supports all possible ICMP types. Fix ICMPMAXTYPE assumptions (now 40 as of this release). Improved graphics support The drm/i915 kernel driver has been updated to support Intel Coffeelake GPUs Add 24-bit pixel format support to the EFI frame buffer code. Significantly improve fbio support for the "scfb" XOrg driver. This allows EFI frame buffers to be used by X in situations where we do not otherwise support the GPU. Partly implement the FBIOBLANK ioctl for display powersaving. Syscons waits for drm modesetting at appropriate places, avoiding races. PS4 4.55 BPF Race Condition Kernel Exploit Writeup Note: While this bug is primarily interesting for exploitation on the PS4, this bug can also potentially be exploited on other unpatched platforms using FreeBSD if the attacker has read/write permissions on /dev/bpf, or if they want to escalate from root user to kernel code execution. As such, I've published it under the "FreeBSD" folder and not the "PS4" folder. Introduction Welcome to the kernel portion of the PS4 4.55FW full exploit chain write-up. This bug was found by qwerty, and is fairly unique in the way it's exploited, so I wanted to do a detailed write-up on how it worked. The full source of the exploit can be found here. I've previously covered the webkit exploit implementation for userland access here. FreeBSD or Sony's fault? Why not both... Interestingly, this bug is actually a FreeBSD bug and was not (at least directly) introduced by Sony code. While this is a FreeBSD bug however, it's not very useful for most systems because the /dev/bpf device driver is root-owned, and the permissions for it are set to 0600 (meaning owner has read/write privileges, and nobody else does) - though it can be used for escalating from root to kernel mode code execution. However, let’s take a look at the make_dev() call inside the PS4 kernel for /dev/bpf (taken from a 4.05 kernel dump). seg000:FFFFFFFFA181F15B lea rdi, unk_FFFFFFFFA2D77640 seg000:FFFFFFFFA181F162 lea r9, aBpf ; "bpf" seg000:FFFFFFFFA181F169 mov esi, 0 seg000:FFFFFFFFA181F16E mov edx, 0 seg000:FFFFFFFFA181F173 xor ecx, ecx seg000:FFFFFFFFA181F175 mov r8d, 1B6h seg000:FFFFFFFFA181F17B xor eax, eax seg000:FFFFFFFFA181F17D mov cs:qword_FFFFFFFFA34EC770, 0 seg000:FFFFFFFFA181F188 call make_dev We see UID 0 (the UID for the root user) getting moved into the register for the 3rd argument, which is the owner argument. However, the permissions bits are being set to 0x1B6, which in octal is 0666. This means anyone can open /dev/bpf with read/write privileges. I’m not sure why this is the case, qwerty speculates that perhaps bpf is used for LAN gaming. In any case, this was a poor design decision because bpf is usually considered privileged, and should not be accessible to a process that is completely untrusted, such as WebKit. On most platforms, permissions for /dev/bpf will be set to 0x180, or 0600. Race Conditions - What are they? The class of the bug abused in this exploit is known as a "race condition". Before we get into bug specifics, it's important for the reader to understand what race conditions are and how they can be an issue (especially in something like a kernel). Often in complex software (such as a kernel), resources will be shared (or "global"). This means other threads could potentially execute code that will access some resource that could be accessed by another thread at the same point in time. What happens if one thread accesses this resource while another thread does without exclusive access? Race conditions are introduced. Race conditions are defined as possible scenarios where events happen in a sequence different than the developer intended which leads to undefined behavior. In simple, single-threaded programs, this is not an issue because execution is linear. In more complex programs where code can be running in parallel however, this becomes a real issue. To prevent these problems, atomic instructions and locking mechanisms were introduced. When one thread wants to access a critical resource, it wi

May 29, 20181h 44m

Episode 247: Interning for FreeBSD | BSD Now 247

FreeBSD internship learnings, exciting developments coming to FreeBSD, running FreeNAS on DigitalOcean, Network Manager control for OpenBSD, OpenZFS User Conference Videos are here and batch editing files with ed. Headlines What I learned during my FreeBSD intership Hi, my name is Mitchell Horne. I am a computer engineering student at the University of Waterloo, currently in my third year of studies, and fortunate to have been one of the FreeBSD Foundation’s co-op students this past term (January to April). During this time I worked under Ed Maste, in the Foundation’s small Kitchener office, along with another co-op student Arshan Khanifar. My term has now come to an end, and so I’d like to share a little bit about my experience as a newcomer to FreeBSD and open-source development. I’ll begin with some quick background — and a small admission of guilt. I have been an open-source user for a large part of my life. When I was a teenager I started playing around with Linux, which opened my eyes to the wider world of free software. Other than some small contributions to GNOME, my experience has been mostly as an end user; however, the value of these projects and the open-source philosophy was not lost on me, and is most of what motivated my interest in this position. Before beginning this term I had no personal experience with any of the BSDs, although I knew of their existence and was extremely excited to receive the position. I knew it would be a great opportunity for growth, but I must confess that my naivety about FreeBSD caused me to make the silent assumption that this would be a form of compromise — a stepping stone that would eventually allow me to work on open-source projects that are somehow “greater” or more “legitimate”. After four months spent immersed in this project I have learned how it operates, witnessed its community, and learned about its history. I am happy to admit that I was completely mistaken. Saying it now seems obvious, but FreeBSD is a project with its own distinct uses, goals, and identity. For many there may exist no greater opportunity than to work on FreeBSD full time, and with what I know now I would have a hard time coming up with a project that is more “legitimate”. What I Liked In all cases, the work I submitted this term was reviewed by no less than two people before being committed. The feedback and criticism I received was always both constructive and to the point, and it commented on everything from high-level ideas to small style issues. I appreciate having these thorough reviews in place, since I believe it ultimately encourages people to accept only their best work. It is indicative of the high quality that already exists within every aspect of this project, and this commitment to quality is something that should continue to be honored as a core value. As I’ve discovered in some of my previous work terms, it is all too easy cut corners in the name of a deadline or changing priorities, but the fact that FreeBSD doesn’t need to make these types of compromises is a testament to the power of free software. It’s a small thing, but the quality and completeness of the FreeBSD documentation was hugely helpful throughout my term. Everything you might need to know about utilities, library functions, the kernel, and more can be found in a man page; and the handbook is a great resource as both an introduction to the operating system and a reference. I only wish I had taken some time earlier in the term to explore the different documents more thoroughly, as they cover a wide range of interesting and useful topics. The effort people put into writing and maintaining FreeBSD’s documentation is easy to overlook, but its value cannot be overstated. What I Learned Although there was a lot I enjoyed, there were certainly many struggles I faced throughout the term, and lessons to be learned from them. I expect that some of issues I faced may be specific to FreeBSD, while others may be common to open-source projects in general. I don’t have enough experience to speculate on which is which, so I will leave this to the reader. The first lesson can be summed up simply: you have to advocate for your own work. FreeBSD is made up in large part by volunteer efforts, and in many cases there is more work to go around than people available to do it. A consequence of this is that there will not be anybody there to check up on you. Even in my position where I actually had a direct supervisor, Ed often had his plate full with so many other things that the responsibility to find someone to look at my work fell to me. Admittedly, a couple of smaller changes I worked on got left behind or stuck in review simply because there wasn’t a clear person/place to reach out to. I think this is both a barrier of entry to FreeBSD and a mental hurdle that I needed to get over. If there’s a change you want to see included or reviewed, then you may have to be the one to push for it, and there’s nothing wrong with that. P

May 24, 20181h 29m

Episode 246: Properly Coordinated Disclosure | BSD Now 246

How Intel docs were misinterpreted by almost any OS, a look at the mininet SDN emulator, do’s and don’ts for FreeBSD, OpenBSD community going gold, ed mastery is a must read, and the distributed object store minio on FreeBSD. Headlines Intel documentation flaw sees instruction misimplemented in almost every OS A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures Software Developer's Manual (SDM) was mishandled in the development of some or all operating-system kernels, resulting in unexpected behavior for #DB exceptions that are deferred by MOV SS or POP SS, as demonstrated by (for example) privilege escalation in Windows, macOS, some Xen configurations, or FreeBSD, or a Linux kernel crash. OS kernels may not expect this order of events and may therefore experience unexpected behavior when it occurs. + A detailed white paper describes this behavior here + FreeBSD Commit Thank you to the MSRC Incident Response Team, and in particular Greg Lenti and Nate Warfield, for coordinating the response to this issue across multiple vendors. Thanks to Computer Recycling at The Working Center of Kitchener for making hardware available to allow us to test the patch on additional CPU families. + FreeBSD Security Advisory + DragonFlyBSD Post + NetBSD does not support debug register and so is not affected. + OpenBSD also appears to not be affected, “We are not aware of further vendor information regarding this vulnerability.” + IllumOS Not Impacted Guest Post – A Look at SDN Emulator Mininet A guest post on the FreeBSD Foundation’s blog by developer Ayaka Koshibe At this year’s AsiaBSDCon, I presented a talk about a SDN network emulator called Mininet, and my ongoing work to make it more portable. That presentation was focused on the OpenBSD version of the port, and I breezed past the detail that I also had a version or Mininet working on FreeBSD. Because I was given the opportunity, I’d like to share a bit about the FreeBSD version of Mininet. It will not only be about what Mininet is and why it might be interesting, but also a recounting of my experience as a user making a first-time attempt at porting an application to FreeBSD. Mininet started off as a tool used by academic researchers to emulate OpenFlow networks when they didn’t have convenient access to actual networks. Because of its history, Mininet became associated strongly with networks that use OpenFlow for their control channels. But, it has also become fairly popular among developers working in, and among several universities for research and teaching about, SDN (Software Defined Networking) I began using Mininet as an intern at my university’s network research lab. I was using FreeBSD by that time, and wasn’t too happy to learn that Mininet wouldn’t work on anything but Linux. I gradually got tired of having to run a Linux VM just to use Mininet, and one day it clicked in my mind that I can actually try porting it to FreeBSD. Mininet creates a topology using the resource virtualization features that Linux has. Specifically, nodes are bash processes running in network namespaces, and the nodes are interconnected using veth virtual Ethernet links. Switches and controllers are just nodes whose shells have run the right commands to configure a software switch or start a controller application. Mininet can therefore be viewed as a series of Python libraries that run the system commands necessary to create network namespaces and veth interfaces, assemble a specified topology, and coordinate how user commands aimed at nodes (since they are just shells) are run. Coming back to the port, I chose to use vnet jails to replace the network namespaces, and epair(4) links to replace the veth links. For the SDN functionality, I needed at least one switch and controller that can be run on FreeBSD. I chose OpenvSwitch(OVS) for the switch, since it was available in ports and is well-known by the SDN world, and Ryu for the controller since it’s being actively developed and used and supports more recent versions of OpenFlow. I have discussed the possibility of upstreaming my work. Although they were excited about it, I was asked about a script for creating VMs with Mininet preinstalled, and continuous integration support for my fork of the repository. I started taking a look at the release scripts for creating a VM, and after seeing that it would be much easier to use the scripts if I can get Mininet and Ryu added to the ports tree, I also tried a hand at submitting some ports. For CI support, Mininet uses Travis, which unfortunately doesn’t support FreeBSD. For this, I plan to look at a minimalistic CI tool called contbuild, which looks simple enough to get running and is written portably. This is very much a work-in-progress, and one going at a glacial pace. Even though the company that I work for does use Mininet, but doesn’t use FreeBSD, so this is something that I’ve been working on in my free time. Earlier on, it was the learning curve that ma

May 17, 20181h 29m

Episode 245: ZFS User Conf 2018 | BSD Now 245

Allan’s recap of the ZFS User conference, first impressions of OmniOS by a BSD user, Nextcloud 13 setup on FreeBSD, OpenBSD on a fanless desktop computer, an intro to HardenedBSD, and DragonFlyBSD getting some SMP improvements. Headlines ZFS User Conference Recap Attendees met for breakfast on the fourth floor, in a lunchroom type area just outside of the theatre. One entire wall was made of lego base plates, and there were buckets of different coloured lego embedded in the wall. The talks started with Matt Ahrens discussing how the 2nd most requested feature of ZFS, Device Removal, has now landed, then pivoting into the MOST requested feature, RAID-Z expansion, and his work on that so far, which included the first functional prototype, on FreeBSD. Then our friend Calvin Hendryx-Parker presented how he solves all of his backup headaches with ZFS. I provided him some helpful hints to optimize his setup and improve the throughput of his backups Then Steven Umbehocker of OSNEXUS talked about their products, and how they manage large numbers of ZFS nodes After a very nice lunch, Orlando Pichardo of Micron talked about the future of flash, and their new 7.5TB SATA SSDs. Discussion of these devices after the talk may lead to enhancements to ZFS to better support these new larger flash devices that use larger logical sector sizes. Alek Pinchuk of Datto talked about Pool Layout Considerations then Tony Hutter of LLNL talked about the release process for ZFS on Linux Then Tom Caputi of Datto presented: Helping Developers Help You, guidance for users submitting bug reports, with some good and bad examples Then we had a nice cocktail party and dinner, and stayed late into the night talked about ZFS The next day, Jervin Real of Percona, presented: ZFS and MySQL on Linux, the Sweet Spots. Mostly outlining some benchmark they had done, some of the results were curious and some additional digging may turn up enhancements that can be made to ZFS, or just better tuning advice for high traffic MySQL servers. Then I presented my ZSTD compression work, which had been referenced in 2 of the previous talks, as people are anxious to get their hands on this code. Lastly, Eric Sproul of Circonus, gave his talk: Thank You, ZFS. It thanked ZFS and its Community for making their companies product possible, and then provided an update to his presentation from last year, where they were having problems with extremely high levels of ZFS fragmentation. This also sparked a longer conversation after the talk was over. Then we had a BBQ lunch, and after some more talking, the conference broke up. Initial OmniOS impressions by a BSD user I had been using FreeBSD as my main web server OS since 2012 and I liked it so much that I even contributed money and code to it. However, since the FreeBSD guys (and gals) decided to install anti-tech feminism, I have been considering to move away from it for quite some time now. As my growing needs require stronger hardware, it was finally time to rent a new server. I do not intend to run FreeBSD on it. Although the most obvious choice would be OpenBSD (I run it on another server and it works just fine), I plan to have a couple of databases running on the new machine, and database throughput has never been one of OpenBSD's strong points. This is my chance to give illumos another try. As neither WiFi nor desktop environments are relevant on a no-X11 server, the server-focused OmniOS seemed to fit my needs. My current (to be phased out) setup on FreeBSD is: apache24 with SSL support, running five websites on six domains (both HTTP and HTTPS) a (somewhat large) Tiny Tiny RSS installation from git, updated via cronjob sbcl running a daily cronjob of my Web-to-RSS parser an FTP server where I share stuff with friends an IRC bouncer MariaDB and PostgreSQL for some of the hosted services I would not consider anything of that too esoteric for a modern operating system. Since I was not really using anything mod_rewrite-related, I was perfectly ready to replace apache24 by nginx, remembering that the prepackaged apache24 on FreeBSD did not support HTTPS out of the box and I had ended up installing it from the ports. That is the only change in my setup which I am actively planning. So here's what I noticed. First impressions: Hooray, a BSD boot loader! Finally an operating system without grub - I made my experiences with that and I don't want to repeat them too often. It is weird that the installer won't accept "mydomain.org" as a hostname but sendmail complains that "mydomain" is not a valid hostname right from the start, OmniOS sent me into Maintenance Mode to fix that. A good start, right? So the first completely new thing I had to find out on my new shiny toy was how to change the hostname. There is no /etc/rc.conf in it and hostname mydomain.org was only valid for one login session. I found out that the hostname has to be changed in three different files under /etc on Solaris - the third one did not even exist fo

May 10, 20181h 24m

Episode 244: C is a Lie | BSD Now 244

Arcan and OpenBSD, running OpenBSD 6.3 on RPI 3, why C is not a low-level language, HardenedBSD switching back to OpenSSL, how the Internet was almost broken, EuroBSDcon CfP is out, and the BSDCan 2018 schedule is available. Headlines Towards Secure System Graphics: Arcan and OpenBSD Let me preface this by saying that this is a (very) long and medium-rare technical article about the security considerations and minutiae of porting (most of) the Arcan ecosystem to work under OpenBSD. The main point of this article is not so much flirting with the OpenBSD crowd or adding further noise to software engineering topics, but to go through the special considerations that had to be taken, as notes to anyone else that decides to go down this overgrown and lonesome trail, or are curious about some less than obvious differences between how these things “work” on Linux vs. other parts of the world. A disclaimer is also that most of this have been discovered by experimentation and combining bits and pieces scattered in everything from Xorg code to man pages, there may be smarter ways to solve some of the problems mentioned – this is just the best I could find within the time allotted. I’d be happy to be corrected, in patch/pull request form that is 😉 Each section will start with a short rant-like explanation of how it works in Linux, and what the translation to OpenBSD involved or, in the cases that are still partly or fully missing, will require. The topics that will be covered this time are: Graphics Device Access Hotplug Input Backlight Xorg Pledging Missing Installing OpenBSD 6.3 (snapshots) on Raspberry pi 3 The Easy way Installing the OpenBSD on raspberry pi 3 is very easy and well documented which almost convinced me of not writing about it, but still I felt like it may help somebody new to the project (But again I really recommend reading the document if you are interested and have the time). Note: I'm always running snapshots and recommend anybody to do it as well. But the snapshots links will change to the next version every 6 month, so I changed the links to the 6.3 version to keep the blog post valid over times. If you're familiar to the OpenBSD flavors, feel free to use the snapshots links instead. Requirements Due to the lack of driver, the OpenBSD can not boot directly from the SD Card yet, So we'll need an USB Stick for the installtion target aside the SD Card for the U-Boot and installer. Also, a Serial Console connection is required. I Used a PL2303 USB to Serial (TTL) adapter connected to my Laptop via USB port and connected to the Raspberry via TX, RX and GND pins. iXsystems https://www.ixsystems.com/blog/truenas-m-series-veeam-pr-2018/ Why Didn’t Larrabee Fail? Every month or so, someone will ask me what happened to Larrabee and why it failed so badly. And I then try to explain to them that not only didn't it fail, it was a pretty huge success. And they are understandably very puzzled by this, because in the public consciousness Larrabee was like the Itanic and the SPU rolled into one, wasn't it? Well, not quite. So rather than explain it in person a whole bunch more times, I thought I should write it down. This is not a history, and I'm going to skip a TON of details for brevity. One day I'll write the whole story down, because it's a pretty decent escapade with lots of fun characters. But not today. Today you just get the very start and the very end. When I say "Larrabee" I mean all of Knights, all of MIC, all of Xeon Phi, all of the "Isle" cards - they're all exactly the same chip and the same people and the same software effort. Marketing seemed to dream up a new codeword every week, but there was only ever three chips: Knights Ferry / Aubrey Isle / LRB1 - mostly a prototype, had some performance gotchas, but did work, and shipped to partners. Knights Corner / Xeon Phi / LRB2 - the thing we actually shipped in bulk. Knights Landing - the new version that is shipping any day now (mid 2016). That's it. There were some other codenames I've forgotten over the years, but they're all of one of the above chips. Behind all the marketing smoke and mirrors there were only three chips ever made (so far), and only four planned in total (we had a thing called LRB3 planned between KNC and KNL for a while). All of them are "Larrabee", whether they do graphics or not. When Larrabee was originally conceived back in about 2005, it was called "SMAC", and its original goals were, from most to least important: Make the most powerful flops-per-watt machine for real-world workloads using a huge array of simple cores, on systems and boards that could be built into bazillo-core supercomputers. Make it from x86 cores. That means memory coherency, store ordering, memory protection, real OSes, no ugly scratchpads, it runs legacy code, and so on. No funky DSPs or windowed register files or wacky programming models allowed. Do not build another Itanium or SPU! Make it soon. That means keeping it simple. Support the eme

May 3, 20181h 25m

Episode 243: Understanding The Scheduler | BSD Now 243

OpenBSD 6.3 and DragonflyBSD 5.2 are released, bug fix for disappearing files in OpenZFS on Linux (and only Linux), understanding the FreeBSD CPU scheduler, NetBSD on RPI3, thoughts on being a committer for 20 years, and 5 reasons to use FreeBSD in 2018. Headlines OpenBSD 6.3 released Punctual as ever, OpenBSD 6.3 has been releases with the following features/changes: Improved HW support, including: SMP support on OpenBSD/arm64 platforms vmm/vmd improvements: IEEE 802.11 wireless stack improvements Generic network stack improvements Installer improvements Routing daemons and other userland network improvements Security improvements dhclient(8) improvements Assorted improvements OpenSMTPD 6.0.4 OpenSSH 7.7 LibreSSL 2.7.2 DragonFlyBSD 5.2 released Big-ticket items Meltdown and Spectre mitigation support Meltdown isolation and spectre mitigation support added. Meltdown mitigation is automatically enabled for all Intel cpus. Spectre mitigation must be enabled manually via sysctl if desired, using sysctls machdep.spectremitigation and machdep.meltdownmitigation. HAMMER2 H2 has received a very large number of bug fixes and performance improvements. We can now recommend H2 as the default root filesystem in non-clustered mode. Clustered support is not yet available. ipfw Updates Implement state based "redirect", i.e. without using libalias. ipfw now supports all possible ICMP types. Fix ICMPMAXTYPE assumptions (now 40 as of this release). Improved graphics support The drm/i915 kernel driver has been updated to support Intel Coffeelake GPUs Add 24-bit pixel format support to the EFI frame buffer code. Significantly improve fbio support for the "scfb" XOrg driver. This allows EFI frame buffers to be used by X in situations where we do not otherwise support the GPU. Partly implement the FBIOBLANK ioctl for display powersaving. Syscons waits for drm modesetting at appropriate places, avoiding races. + For more details, check out the “All changes since DragonFly 5.0” section. ZFS on Linux bug causes files to disappear A bug in ZoL 0.7.7 caused 0.7.8 to be released just 3 days after the release The bug only impacts Linux, the change that caused the problem was not upstreamed yet, so does not impact ZFS on illumos, FreeBSD, OS X, or Windows The bug can cause files being copied into a directory to not be properly linked to the directory, so they will no longer be listed in the contents of the directory ZoL developers are working on a tool to allow you to recover the data, since no data was actually lost, the files were just not properly registered as part of the directory The bug was introduced in a commit made in February, that attempted to improve performance of datasets created with the case insensitivity option. In an effort to improve performance, they introduced a limit to cap to give up (return ENOSPC) if growing the directory ZAP failed twice. The ZAP is the key-value pair data structure that contains metadata for a directory, including a hash table of the files that are in a directory. When a directory has a large number of files, the ZAP is converted to a FatZAP, and additional space may need to be allocated as additional files are added. Commit cc63068 caused ENOSPC error when copy a large amount of files between two directories. The reason is that the patch limits zap leaf expansion to 2 retries, and return ENOSPC when failed. Finding the root cause of this issue was somewhat hampered by the fact that many people were not able to reproduce the issue. It turns out this was caused by an entirely unrelated change to GNU coreutils. On later versions of GNU Coreutils, the files were returned in a sorted order, resulting in them hitting different buckets in the hash table, and not tripping the retry limit Tools like rsync were unaffected, because they always sort the files before copying If you did not see any ENOSPC errors, you were likely not impacted The intent for limiting retries is to prevent pointlessly growing table to max size when adding a block full of entries with same name in different case in mixed mode. However, it turns out we cannot use any limit on the retry. When we copy files from one directory in readdir order, we are copying in hash order, one leaf block at a time. Which means that if the leaf block in source directory has expanded 6 times, and you copy those entries in that block, by the time you need to expand the leaf in destination directory, you need to expand it 6 times in one go. So any limit on the retry will result in error where it shouldn't. Recommendations for Users from Ryan Yao: The regression makes it so that creating a new file could fail with ENOSPC after which files created in that directory could become orphaned. Existing files seem okay, but I have yet to confirm that myself and I cannot speak for what others know. It is incredibly difficult to reproduce on systems running coreutils 8.23 or later. So far, reports have only come from people using coreutils 8.22 or older. The d

Apr 25, 20181h 25m

Episode 242: Linux Takes The Fastpath | BSD Now 242

TrueOS Stable 18.03 released, a look at F-stack, the secret to an open source business model, intro to jails and jail networking, FreeBSD Foundation March update, and the ipsec Errata. Headlines TrueOS STABLE 18.03 Release The TrueOS team is pleased to announce the availability of a new STABLE release of the TrueOS project (version 18.03). This is a special release due to the security issues impacting the computing world since the beginning of 2018. In particular, mitigating the “Meltdown” and “Spectre” system exploits make it necessary to update the entire package ecosystem for TrueOS. This release does not replace the scheduled June STABLE update, but provides the necessary and expected security updates for the STABLE release branch of TrueOS, even though this is part-way through our normal release cycle. Important changes between version 17.12 and 18.03 “Meltdown” security fixes: This release contains all the fixes to FreeBSD which mitigate the security issues for systems that utilize Intel-based processors when running virtual machines such as FreeBSD jails. Please note that virtual machines or jails must also be updated to a version of FreeBSD or TrueOS which contains these security fixes. “Spectre” security mitigations: This release contains all current mitigations from FreeBSD HEAD for the Spectre memory-isolation attacks (Variant 2). All 3rd-party packages for this release are also compiled with LLVM/Clang 6 (the “retpoline” mitigation strategy). This fixes many memory allocation issues and enforces stricter requirements for code completeness and memory usage within applications. Unfortunately, some 3rd-party applications became unavailable as pre-compiled packages due to non-compliance with these updated standards. These applications are currently being fixed either by the upstream authors or the FreeBSD port maintainers. If there are any concerns about the availability of a critical application for a specific workflow, please search through the changelog of packages between TrueOS 17.12 and 18.03 to verify the status of the application. Most systems will need microcode updates for additional Spectre mitigations. The microcode updates are not enabled by default. This work is considered experimental because it is in active development by the upstream vendors. If desired, the microcode updates are available with the new devcpu-data package, which is available in the Appcafe. Install this package and enable the new microcode_update service to apply the latest runtime code when booting the system. Important security-based package updates LibreSSL is updated from version 2.6.3 -> 2.6.4 Reminder: LibreSSL is used on TrueOS to build any package which does not explicitly require OpenSSL. All applications that utilize the SSL transport layer are now running with the latest security updates. Browser updates: (Keep in mind that many browsers have also implemented their own security mitigations in the aftermath of the Spectre exploit.) Firefox: 57.0.1 -> 58.0.2 Chromium: 61.0.3163.100 -> 63.0.3239.132 Qt5 Webengine (QupZilla, Falkon, many others): 5.7.1 -> 5.9.4 All pre-compiled packages for this release are built with the latest versions of LLVM/Clang, unless the package explicitly requires GCC. These packages also utilize the latest compile-time mitigations for memory-access security concerns. F-Stack F-Stack is an user space network development kit with high performance based on DPDK, FreeBSD TCP/IP stack and coroutine API. http://www.f-stack.org Introduction With the rapid development of NIC, the poor performance of data packets processing with Linux kernel has become the bottleneck. However, the rapid development of the Internet needs high performance of network processing, kernel bypass has caught more and more attentions. There are various similar technologies appear, such as DPDK, NETMAP and PF_RING. The main idea of kernel bypass is that Linux is only used to deal with control flow, all data streams are processed in user space. Therefore, kernel bypass can avoid performance bottlenecks caused by kernel packet copying, thread scheduling, system calls and interrupts. Furthermore, kernel bypass can achieve higher performance with multi optimizing methods. Within various techniques, DPDK has been widely used because of its more thorough isolation from kernel scheduling and active community support. F-Stack is an open source network framework with high performance based on DPDK. With following characteristics Ultra high network performance which can achieve network card under full load, 10 million concurrent connections, 5 million RPS, 1 million CPS. Transplant FreeBSD 11.01 user space stack, provides a complete stack function, cut a great amount of irrelevant features. Therefore greatly enhance the performance. Support Nginx, Redis and other mature applications, service can easily use F-Stack With Multi-process architecture, easy to extend Provide micro thread interface. Various applications with stateful

Apr 18, 20181h 23m

Episode 241: Bowling in the LimeLight | BSD Now 241

Second round of ZFS improvements in FreeBSD, Postgres finds that non-FreeBSD/non-Illumos systems are corrupting data, interview with Kevin Bowling, BSDCan list of talks, and cryptographic right answers. Headlines [Other big ZFS improvements you might have missed] 9075 Improve ZFS pool import/load process and corrupted pool recovery One of the first tasks during the pool load process is to parse a config provided from userland that describes what devices the pool is composed of. A vdev tree is generated from that config, and then all the vdevs are opened. The Meta Object Set (MOS) of the pool is accessed, and several metadata objects that are necessary to load the pool are read. The exact configuration of the pool is also stored inside the MOS. Since the configuration provided from userland is external and might not accurately describe the vdev tree of the pool at the txg that is being loaded, it cannot be relied upon to safely operate the pool. For that reason, the configuration in the MOS is read early on. In the past, the two configurations were compared together and if there was a mismatch then the load process was aborted and an error was returned. The latter was a good way to ensure a pool does not get corrupted, however it made the pool load process needlessly fragile in cases where the vdev configuration changed or the userland configuration was outdated. Since the MOS is stored in 3 copies, the configuration provided by userland doesn't have to be perfect in order to read its contents. Hence, a new approach has been adopted: The pool is first opened with the untrusted userland configuration just so that the real configuration can be read from the MOS. The trusted MOS configuration is then used to generate a new vdev tree and the pool is re-opened. When the pool is opened with an untrusted configuration, writes are disabled to avoid accidentally damaging it. During reads, some sanity checks are performed on block pointers to see if each DVA points to a known vdev; when the configuration is untrusted, instead of panicking the system if those checks fail we simply avoid issuing reads to the invalid DVAs. This new two-step pool load process now allows rewinding pools across vdev tree changes such as device replacement, addition, etc. Loading a pool from an external config file in a clustering environment also becomes much safer now since the pool will import even if the config is outdated and didn't, for instance, register a recent device addition. With this code in place, it became relatively easy to implement a long-sought-after feature: the ability to import a pool with missing top level (i.e. non-redundant) devices. Note that since this almost guarantees some loss Of data, this feature is for now restricted to a read-only import. 7614 zfs device evacuation/removal This project allows top-level vdevs to be removed from the storage pool with “zpool remove”, reducing the total amount of storage in the pool. This operation copies all allocated regions of the device to be removed onto other devices, recording the mapping from old to new location. After the removal is complete, read and free operations to the removed (now “indirect”) vdev must be remapped and performed at the new location on disk. The indirect mapping table is kept in memory whenever the pool is loaded, so there is minimal performance overhead when doing operations on the indirect vdev. The size of the in-memory mapping table will be reduced when its entries become “obsolete” because they are no longer used by any block pointers in the pool. An entry becomes obsolete when all the blocks that use it are freed. An entry can also become obsolete when all the snapshots that reference it are deleted, and the block pointers that reference it have been “remapped” in all filesystems/zvols (and clones). Whenever an indirect block is written, all the block pointers in it will be “remapped” to their new (concrete) locations if possible. This process can be accelerated by using the “zfs remap” command to proactively rewrite all indirect blocks that reference indirect (removed) vdevs. Note that when a device is removed, we do not verify the checksum of the data that is copied. This makes the process much faster, but if it were used on redundant vdevs (i.e. mirror or raidz vdevs), it would be possible to copy the wrong data, when we have the correct data on e.g. the other side of the mirror. Therefore, mirror and raidz devices can not be removed. You can use ‘zpool detach’ to downgrade a mirror to a single top-level device, so that you can then remove it 7446 zpool create should support efi system partition This one was not actually merged into FreeBSD, as it doesn’t apply currently, but I would like to switch the way FreeBSD deals with full disks to be closer to IllumOS to make automatic spare replacement a hands-off operation. Since we support whole-disk configuration for boot pool, we also will need whole disk support with UEFI boot and for this, zp

Apr 12, 20182h 1m

Episode 240: TCP Blackbox Recording | BSD Now 240

New ZFS features landing in FreeBSD, MAP_STACK for OpenBSD, how to write safer C code with Clang’s address sanitizer, Michael W. Lucas on sponsor gifts, TCP blackbox recorder, and Dell disk system hacking. Headlines [A number of Upstream ZFS features landed in FreeBSD this week] 9188 increase size of dbuf cache to reduce indirect block decompression With compressed ARC (6950) we use up to 25% of our CPU to decompress indirect blocks, under a workload of random cached reads. To reduce this decompression cost, we would like to increase the size of the dbuf cache so that more indirect blocks can be stored uncompressed. If we are caching entire large files of recordsize=8K, the indirect blocks use 1/64th as much memory as the data blocks (assuming they have the same compression ratio). We suggest making the dbuf cache be 1/32nd of all memory, so that in this scenario we should be able to keep all the indirect blocks decompressed in the dbuf cache. (We want it to be more than the 1/64th that the indirect blocks would use because we need to cache other stuff in the dbuf cache as well.) In real world workloads, this won't help as dramatically as the example above, but we think it's still worth it because the risk of decreasing performance is low. The potential negative performance impact is that we will be slightly reducing the size of the ARC (by ~3%). 9166 zfs storage pool checkpoint The idea of Storage Pool Checkpoint (aka zpool checkpoint) deals with exactly that. It can be thought of as a “pool-wide snapshot” (or a variation of extreme rewind that doesn’t corrupt your data). It remembers the entire state of the pool at the point that it was taken and the user can revert back to it later or discard it. Its generic use case is an administrator that is about to perform a set of destructive actions to ZFS as part of a critical procedure. She takes a checkpoint of the pool before performing the actions, then rewinds back to it if one of them fails or puts the pool into an unexpected state. Otherwise, she discards it. With the assumption that no one else is making modifications to ZFS, she basically wraps all these actions into a “high-level transaction”. More information 8484 Implement aggregate sum and use for arc counters In pursuit of improving performance on multi-core systems, we should implements fanned out counters and use them to improve the performance of some of the arc statistics. These stats are updated extremely frequently, and can consume a significant amount of CPU time. And a small bug fix authored by me: 9321 arcloancompressedbuf() can increment arcloanedbytes by the wrong value arcloancompressedbuf() increments arcloanedbytes by psize unconditionally In the case of zfscompressedarcenabled=0, when the buf is returned via arcreturnbuf(), if ARCBUFCOMPRESSED(buf) is false, then arcloanedbytes is decremented by lsize, not psize. Switch to using arcbufsize(buf), instead of psize, which will return psize or lsize, depending on the result of ARCBUF_COMPRESSED(buf). MAP_STACK for OpenBSD Almost 2 decades ago we started work on W^X. The concept was simple. Pages that are writable, should not be executable. We applied this concept object by object, trying to seperate objects with different qualities to different pages. The first one we handled was the signal trampoline at the top of the stack. We just kept making changes in the same vein. Eventually W^X came to some of our kernel address spaces also. The fundamental concept is that an object should only have the permissions necessary, and any other operation should fault. The only permission separations we have are kernel vs userland, and then read, write, and execute. How about we add another new permission! This is not a hardware permission, but a software permission. It is opportunistically enforced by the kernel. the permission is MAPSTACK. If you want to use memory as a stack, you must mmap it with that flag bit. The kernel does so automatically for the stack region of a process's stack. Two other types of stack occur: thread stacks, and alternate signal stacks. Those are handled in clever ways. When a system call happens, we check if the stack-pointer register points to such a page. If it doesn't, the program is killed. We have tightened the ABI. You may no longer point your stack register at non-stack memory. You'll be killed. This checking code is MI, so it works for all platforms. Since page-permissions are generally done on page boundaries, there is caveat that thread and altstacks must now be page-sized and page-aligned, so that we can enforce the MAPSTACK attribute correctly. It is possible that a few ports need some massaging to satisfy this condition, but we haven't found any which break yet. A syslog_r has been added so that we can identify these failure cases. Also, the faulting cases are quite verbose for now, to help identify the programs we need to repair. **iXsystems** Writing Safer C with the Clang Address Sanitizer We wanted to improv

Apr 7, 20181h 39m

Episode 239: The Return To ptrace | BSD Now 239

OpenBSD firewalling Windows 10, NetBSD’s return to ptrace, TCP Alternative Backoff, the BSD Poetic license, and AsiaBSDcon 2018 videos available. RSS Feeds: MP3 Feed | iTunes Feed | HD Vid Feed | HD Torrent Feed Become a supporter on Patreon: - Show Notes: - Headlines Preventing Windows 10 and untrusted software from having full access to the internet using OpenBSD Whilst setting up one of my development laptops to port some software to Windows I noticed Windows 10 doing crazy things like installing or updating apps and games by default after initial setup. The one I noticed in particular was Candy Crush Soda Saga which for those who don't know of it is some cheesy little puzzle game originally for consumer devices. I honestly did not want software like this near to a development machine. It has also been reported that Windows 10 now also updates core system software without notifying the user. Surely this destroys any vaguely deterministic behaviour, in my opinion making Windows 10 by default almost useless for development testbeds. Deciding instead to start from scratch but this time to set the inbuilt Windows Firewall to be very restrictive and only allow a few select programs to communicate. In this case all I really needed to be online was Firefox, Subversion and Putty. To my amusement (and astonishment) I found out that the Windows firewall could be modified to give access very easily by programs during installation (usually because this task needs to be done with admin privileges). It also seems that Windows store Apps can change the windows firewall settings at any point. One way to get around this issue could be to install a 3rd party firewall that most software will not have knowledge about and thus not attempt to break through. However the only decent firewall I have used was Sygate Pro which unfortunately is no longer supported by recent operating systems. The last supported versions was 2003, XP and 2000. In short, I avoid 3rd party firewalls. Instead I decided to trap Windows 10 (and all of it's rogue updaters) behind a virtual machine running OpenBSD. This effectively provided me with a full blown firewall appliance. From here I could then allow specific software I trusted through the firewall (via a proxy) in a safe, controlled and deterministic manner. For other interested developers (and security conscious users) and for my own reference, I have listed the steps taken here: 1) First and foremost disable the Windows DHCP service - this is so no IP can be obtained on any interface. This effectively stops any communication with any network on the host system. This can be done by running services.msc with admin privileges and stopping and disabling the service called DHCP Client. 2) Install or enable your favorite virtualization software - I have tested this with both VirtualBox and Hyper-V. Note that on non-server versions of Windows, in order to get Hyper-V working, your processor also needs to support SLAT which is daft so to avoid faffing about, I recommend using VirtualBox to get round this seemingly arbitrary restriction. 3) Install OpenBSD on the VM - Note, if you decide to use Hyper-V, its hardware support isn't 100% perfect to run OpenBSD and you will need to disable a couple of things in the kernel. At the initial boot prompt, run the following commands. config -e -o /bsd /bsd disable acpi disable mpbios 4) Add a host only virtual adapter to the VM - This is the one which we are going to connect through the VM with. Look at the IP that VirtualBox assigns this in network manager on the host machine. Mine was [b]192.168.56.1[/b]. Set up the adapter in the OpenBSD VM to have a static address on the same subnet. For example [b]192.168.56.2[/b]. If you are using Hyper-V and OpenBSD, make sure you add a "Legacy Interface" because no guest additions are available. Then set up a virtual switch which is host only. 5) Add a bridged adapter to the VM - then assign it to whichever interface you wanted to connect to the external network with. Note that if using Wireless, set the bridged adapters MAC address to the same as your physical device or the access point will reject it. This is not needed (or possible) on Hyper-V because the actual device is "shared" rather than bridged so the same MAC address is used. Again, if you use Hyper-V, then add another virtual switch and attach it to your chosen external interface. VMs in Hyper-V "share" an adapter within a virtual switch and there is the option to also disable the hosts ability to use this interface at the same time which is fine for an additional level of security if those pesky rogue apps and updaters can also enable / disable DHCP service one day which wouldn't be too surprising. 6) Connect to your network in the host OS - In case of Wireless, select the correct network from the list and type in a password if needed. Windows will probably say "no internet available", it also does not assign an IP address which is fine. 7) Install the Squid p

Mar 29, 20181h 32m

238: VLAN-Zezes-ki in Hardware

Looking at Lumina Desktop 2.0, 2 months of KPTI development in SmartOS, OpenBSD email service, an interview with Ryan Zezeski, NomadBSD released, and John Carmack's programming retreat with OpenBSD. This episode was brought to you by Headlines Looking at Lumina Desktop 2.0 A few weeks ago I sat down with Lead Developer Ken Moore of the TrueOS Project to get answers to some of the most frequently asked questions about Lumina Desktop from the open source community. Here is what he said on Lumina Desktop 2.0. Do you have a question for Ken and the rest of the team over at the TrueOS Project? Make sure to read the interview and comment below. We are glad to answer your questions! Ken: Lumina Desktop 2.0 is a significant overhaul compared to Lumina 1.x. Almost every single subsystem of the desktop has been streamlined, resulting in a nearly-total conversion in many important areas. With Lumina Desktop 2.0 we will finally achieve our long-term goal of turning Lumina into a complete, end-to-end management system for the graphical session and removing all the current runtime dependencies from Lumina 1.x (Fluxbox, xscreensaver, compton/xcompmgr). The functionality from those utilities is now provided by Lumina Desktop itself. Going along with the session management changes, we have compressed the entire desktop into a single, multi-threaded binary. This means that if any rogue script or tool starts trying to muck about with the memory used by the desktop (probably even more relevant now than when we started working on this), the entire desktop session will close/crash rather than allowing targeted application crashes to bypass the session security mechanisms. By the same token, this also prevents “man-in-the-middle” type of attacks because the desktop does not use any sort of external messaging system to communicate (looking at you dbus). This also gives a large performance boost to Lumina Desktop The entire system for how a user’s settings get saved and loaded has been completely redone, making it a “layered” settings system which allows the default settings (Lumina) to get transparently replaced by system settings (OS/Distributor/SysAdmin) which can get replaced by individual user settings. This results in the actual changes in the user setting files to be kept to a minimum and allows for a smooth transition between updates to the OS or Desktop. This also provides the ability to “restrict” a user’s desktop session (based on a system config file) to the default system settings and read-only user sessions for certain business applications. The entire graphical interface has been written in QML in order to fully-utilize hardware-based GPU acceleration with OpenGL while the backend logic and management systems are still written entirely in C++. This results in blazing fast performance on the backend systems (myriad multi-threaded C++ objects) as well as a smooth and responsive graphical interface with all the bells and whistles (drag and drop, compositing, shading, etc). Q: Are there future plans to implement something like Lumina in a MAC Jail? While I have never tried out Lumina in a MAC jail, I do not see anything on that page which should stop it from running in one right now. Lumina is already designed to be run as an unpriviledged user and is very smart about probing the system to find out what is/not available before showing anything to the user. The only thing that comes to mind is that you might need to open up some other system devices so that X11 itself can draw to the display (graphical environment setup is a bit different than CLI environment). Q: I look forward to these changes. I know the last time I used it when I would scroll I would get flashes like the refresh rate was not high enough. It will be nice to have a fast system as well as I know with the more changes Linux is becoming slower. Not once it has loaded but in the loading process. I will do another download when these changes come out and install again and maybe stay this time. If I recall correctly, one of the very first versions of Lumina (pre-1.0) would occasionally flicker. If that is still happening, you might want to verify that you are using the proper video driver for your hardware and/or enable the compositor within the Lumina settings. Q: Why was enlightenment project not considered for TrueOS? It is BSD licensed and is written in C. This was a common question about 4(?) years ago with the first release of the Lumina desktop and it basically boiled down to long-term support and reliability of the underlying toolkit. Some of the things we had to consider were: cross-platform/cross-architecture support, dependency reliability and support framework (Qt5 > EFL), and runtime requirements and dependency tracking (Qt5 is lighter than the EFL). That plus the fact that the EFL specifically states that it is linux-focused and the BSD’s are just an afterthought (especially at the time we were doing the evaluation). Q: I have two questio

Mar 21, 20182h 3m

237: AsiaBSDcon 2018

AsiaBSDcon review, Meltdown and Spectre Patches in FreeBSD stable, Interview with MidnightBSD founder, 8 months with TrueOS, mysteries of GNU and BSD split This episode was brought to you by Headlines AsiaBSDCon 2018 has concluded We have just returned from AsiaBSDCon in Tokyo, Japan last weekend Please excuse our jetlag The conference consisted two days of meeting followed by 2 days of paper presentations We arrived a few days early to see some sights and take a few extra delicious meals in Tokyo The first day of meetings was a FreeBSD developer summit (while Benedict was teaching his two tutorials) where we discussed the FreeBSD release cycle and our thoughts on improving it, the new Casper capsicum helper service, and developments in SDIO which will eventually enable WiFi and SD card readers on more embedded devices The second day of meetings consisted of bhyvecon, a miniconf that covered development in all hypervisors on all BSDs. It also included presentations on the porting of bhyve to IllumOS. Then the conference started There were a number of great presentations, plus an amazing hallway track as usual It was great to see many old friends and to spend time discussing the latest happenings in BSD. A couple of people came by and asked to take a picture with us and we were happy to do that. *** FreeBSD releases Spectre and Meltdown mitigations for 11.1 Speculative execution vulnerability mitigation is a work in progress. This advisory addresses the most significant issues for FreeBSD 11.1 on amd64 CPUs. We expect to update this advisory to include 10.x for amd64 CPUs. Future FreeBSD releases will address this issue on i386 and other CPUs. freebsd-update will include changes on i386 as part of this update due to common code changes shared between amd64 and i386, however it contains no functional changes for i386 (in particular, it does not mitigate the issue on i386). Many modern processors have implementation issues that allow unprivileged attackers to bypass user-kernel or inter-process memory access restrictions by exploiting speculative execution and shared resources (for example, caches). An attacker may be able to read secret data from the kernel or from a process when executing untrusted code (for example, in a web browser). Meltdown: The mitigation is known as Page Table Isolation (PTI). PTI largely separates kernel and user mode page tables, so that even during speculative execution most of the kernel's data is unmapped and not accessible. A demonstration of the Meltdown vulnerability is available at https://github.com/dag-erling/meltdown. A positive result is definitive (that is, the vulnerability exists with certainty). A negative result indicates either that the CPU is not affected, or that the test is not capable of demonstrating the issue on the CPU (and may need to be modified). A patched kernel will automatically enable PTI on Intel CPUs. The status can be checked via the vm.pmap.pti sysctl PTI introduces a performance regression. The observed performance loss is significant in microbenchmarks of system call overhead, but is much smaller for many real workloads. Spectre V2: There are two common mitigations for Spectre V2. This patch includes a mitigation using Indirect Branch Restricted Speculation, a feature available via a microcode update from processor manufacturers. The alternate mitigation, Retpoline, is a feature available in newer compilers. The feasibility of applying Retpoline to stable branches and/or releases is under investigation. The patch includes the IBRS mitigation for Spectre V2. To use the mitigation the system must have an updated microcode; with older microcode a patched kernel will function without the mitigation. IBRS can be disabled via the hw.ibrs_disable sysctl (and tunable), and the status can be checked via the hw.ibrs_active sysctl. IBRS may be enabled or disabled at runtime. Additional detail on microcode updates will follow. Wiki tracking the vulnerabilities and mitigations on different platforms *** Interview with MidnightBSD Founder and Lead Dev Lucas Holt Recently, I have taken a little dip into the world of BSD. As part of my attempt to understand the BSD world a little better, I connected with Lucas Holt (MidnightBSD founder and lead developer) to ask him a few questions about his project. Here are his answers. It’s FOSS: Please explain MidnightBSD in a nutshell. How is it different than other BSDs? Lucas Holt: MidnightBSD is a desktop focused operating system. When it’s considered stable, it will provide a full desktop experience. This differs from other efforts such as TrueOS or GhostBSD in that it’s not a distro of FreeBSD, but rather a fork. MidnightBSD has its own package manager, mport as well as unique package cluster software and several features built into user land such as mDNSresponder, libdispatch, and customizations throughout the system. It’s FOSS: Who is MidnightBSD aimed at? Lucas Holt: The goal with MidnightBSD has always been to p

Mar 14, 20181h 39m

236: How a cd works

We’ll cover OpenBSD’s defensive approach to OS security, help you Understanding Syscall Conventions for Different Platforms, Mishandling SMTP Sender Verification, how the cd command works, and the LUA boot loader coming to FreeBSD. This episode was brought to you by Headlines Pledge: OpenBSD’s defensive approach to OS Security The meaning of Pledge is same as in the real world, that is, “a solemn promise or undertaking”. So, in OpenBSD: Calling pledge in a program means to promise that the program will only use certain resources. How does it make a program more secure? It limits the operation of a program. Example: You wrote a program named ‘abc’ that only needed the stdio to just print something to stdout. You added pledge to use only stdio and nothing else. Then, a malicious user found out that there is a vulnerability in your program which one can exploit and get into shell (or root shell). Exploiting your program to open a shell (or root shell) will result in the kernel killing the process with SIGABRT (which cannot be caught/ignored) and will generate a log (which you can find with dmesg). This happens because before executing other codes of your program, the code first pledges not to use anything other than stdio promise/operations. But, opening a shell or root shell will call several other system-calls which are distributed in lots of other promises like “stdio”, “proc”, “exec” etc. They are all forbidden because the program has already promised not to use any promises other than stdio. Pledge is not a system call filter. So, it is not used to restrict system calls. For example, pledge(“read”,NULL) ? wrong syntax of the pledge() pledge(“stdio inet”,NULL) ? correct syntax of the pledge() Pledge works on stdio, dns, inet, etc. promises but not directly on system calls like read, write, etc. And, unique functionality of pledge() is that it works on behavioral approach not just like 1:1 approach with the system calls. On 11 December 2017, Theo de Raadt said: List: openbsd-tech Subject: pledge execpromises From: Theo de Raadt <deraadt () openbsd ! org> Date: 2017–12–11 21:20:51 Message-ID: 6735.1513027251 () cvs ! openbsd ! org This will probably be committed in the next day or so. The 2nd argument of pledge() becomes execpromises, which is what will gets activated after execve. There is also a small new feature called “error”, which causes violating system calls to return -1 with ENOSYS rather than killing the process. This must be used with EXTREME CAUTION because libraries and programs are full of unchecked system calls. If you carry on past one of these failures, your program is in uncharted territory and risks of exploitation become high. “error” is being introduced for a different reason: The pre-exec process’s expectation of what the post-exec process will do might mismatch, so “error” allows things like starting an editor which has no network access or maybe other restrictions in the future… Every Journey Starts with a FAIL...or Understanding Syscall Conventions for Different Platforms Introduction Not long ago I started looking into FreeBSD kernel exploitation. There are only a few resources but probably the best starting point is argp's Phrack article from 2009[0]. And while he does only provide one technique, I wanted to understand it and port it to a modern FreeBSD release before describing new, own researched techniques. Well, at least this was my plan. In reality I ended researching how different operating systems resp. the same operating system but for different architectures implement syscalls. Hence, new exploiting methods have to wait for another post. In this one I want to describe my personal FAIL while porting argp's exploit example to a FreeBSD 11.1-RELEASE running on a 64bit processor. Maybe this will give other people interested in kernel stuff some insights they didn't know before. If you already know how syscalls work on 32bit and 64bit *BSD because you are an experienced exploit or kernel developer, you will probably want to search for something else to read. Moreover, some of the debugging stuff can look laborious because I wanted to show the steps I have done while attacking my problem instead of showing a simple walkthrough to the solution. The Problem argp described in his article vulnerable code consisting of a loadable kernel module which exposes a syscall to the userland. Because it was written around the time when FreeBSD 8-RELEASE came out and because he has written himself that the code needs smaller adjustments to work with this version (it was written for FreeBSD 7) I thought I will first port it to FreeBSD 11.1-RELEASE. Moreover it was written for an Intel 32bit processor architecture as we can see from his shellcode examples. Hence, I wanted to go right away the harder way and modify it to work on an 64bit processor. Why the Original Code Worked While It Was Wrong As written above, the syscall convention for the 32bit architecture is different fro

Mar 7, 20182h 1m

235: I C you BSD

How the term open source was created, running FreeBSD on ThinkPad T530, Moving away from Windows, Unknown Giants, as well as OpenBSD and FreeDOS. This episode was brought to you by Headlines How I coined the term 'open source' In a few days, on February 3, the 20th anniversary of the introduction of the term "open source software" is upon us. As open source software grows in popularity and powers some of the most robust and important innovations of our time, we reflect on its rise to prominence. I am the originator of the term "open source software" and came up with it while executive director at Foresight Institute. Not a software developer like the rest, I thank Linux programmer Todd Anderson for supporting the term and proposing it to the group. This is my account of how I came up with it, how it was proposed, and the subsequent reactions. Of course, there are a number of accounts of the coining of the term, for example by Eric Raymond and Richard Stallman, yet this is mine, written on January 2, 2006. It has never been published, until today. The introduction of the term "open source software" was a deliberate effort to make this field of endeavor more understandable to newcomers and to business, which was viewed as necessary to its spread to a broader community of users. The problem with the main earlier label, "free software," was not its political connotations, but that—to newcomers—its seeming focus on price is distracting. A term was needed that focuses on the key issue of source code and that does not immediately confuse those new to the concept. The first term that came along at the right time and fulfilled these requirements was rapidly adopted: open source. This term had long been used in an "intelligence" (i.e., spying) context, but to my knowledge, use of the term with respect to software prior to 1998 has not been confirmed. The account below describes how the term open source software caught on and became the name of both an industry and a movement. Meetings on computer security In late 1997, weekly meetings were being held at Foresight Institute to discuss computer security. Foresight is a nonprofit think tank focused on nanotechnology and artificial intelligence, and software security is regarded as central to the reliability and security of both. We had identified free software as a promising approach to improving software security and reliability and were looking for ways to promote it. Interest in free software was starting to grow outside the programming community, and it was increasingly clear that an opportunity was coming to change the world. However, just how to do this was unclear, and we were groping for strategies. At these meetings, we discussed the need for a new term due to the confusion factor. The argument was as follows: those new to the term "free software" assume it is referring to the price. Oldtimers must then launch into an explanation, usually given as follows: "We mean free as in freedom, not free as in beer." At this point, a discussion on software has turned into one about the price of an alcoholic beverage. The problem was not that explaining the meaning is impossible—the problem was that the name for an important idea should not be so confusing to newcomers. A clearer term was needed. No political issues were raised regarding the free software term; the issue was its lack of clarity to those new to the concept. Releasing Netscape On February 2, 1998, Eric Raymond arrived on a visit to work with Netscape on the plan to release the browser code under a free-software-style license. We held a meeting that night at Foresight's office in Los Altos to strategize and refine our message. In addition to Eric and me, active participants included Brian Behlendorf, Michael Tiemann, Todd Anderson, Mark S. Miller, and Ka-Ping Yee. But at that meeting, the field was still described as free software or, by Brian, "source code available" software. While in town, Eric used Foresight as a base of operations. At one point during his visit, he was called to the phone to talk with a couple of Netscape legal and/or marketing staff. When he was finished, I asked to be put on the phone with them—one man and one woman, perhaps Mitchell Baker—so I could bring up the need for a new term. They agreed in principle immediately, but no specific term was agreed upon. Between meetings that week, I was still focused on the need for a better name and came up with the term "open source software." While not ideal, it struck me as good enough. I ran it by at least four others: Eric Drexler, Mark Miller, and Todd Anderson liked it, while a friend in marketing and public relations felt the term "open" had been overused and abused and believed we could do better. He was right in theory; however, I didn't have a better idea, so I thought I would try to go ahead and introduce it. In hindsigh

Feb 28, 20182h 5m

234: Code and Community

GSoC 2018 Projects announced, tutorial FreeBSD jails with iocage, new Code of Conduct for FreeBSD, libhijack, and fancy monitoring for OpenSMTPD This episode was brought to you by Headlines Google Summer of Code 2018 FreeBSD FreeBSD Google Summer oF Code Ideas You can join #freebsd-soc on the efnet IRC network to chat with FreeBSD developers interested in mentoring student proposals and projects, past FreeBSD/GSoC students, and other students applying to FreeBSD/GSoC this year. NetBSD You can get a stipend (paid for by Google) and spend a few months getting to know and improving the insides of NetBSD or pkgsrc. The schedule is: 12-27 March Applying 23 April Find out if you were accepted 14 May - 22 August Do the project! We have some suggestions for suitable projects: - ARM EFI bootloader - Using libFuzzer on base tools - Refactoring ALTQ (QoS implementation) and integrating with NPF - Testsuite for libcurses - Improve pkgin Other suggestions and details are at: https://wiki.netbsd.org/projects/gsoc/ These projects are suggestions; you can come up with your own. Suggestions for other suitable projects are welcome. Feel free to contact, or chat around on IRC: irc.freenode.org #netbsd #netbsd-code #pkgsrc Haiku Students: How to Apply for a Haiku Idea Project Ideas > If you have questions you can contact the devs on IRC: irc.freenode.org #haiku FreeBSD Jails with iocage Introduction FreeBSD jails allow users to run multiple, isolated instances of FreeBSD on a single server. Iocage simplifies the management of FreeBSD Jails. Following this tutorial, the jails will be configured to bind to an IP address on the jail host's internal network, and the host OS will pass traffic from the external network to the jail. The jails will be managed with Iocage. Iocage uses ZFS properties to store configuration data for each jail, so a ZFS file system is required. Network setup These steps will: Set up the internal network. Enable the pf packet filter Configure pf pass internet traffic to and from the jail. PF is full featured firewall, and can do more than just pass traffic to an internal network. Refer to the PF documentation for additional configuration options. Run the following to configure the internal network and enable pf. sysrc cloned_interfaces+="lo1" sysrc ifconfig_lo1="inet 192.0.2.1/24" sysrc pf_enable="YES" Put the following in /etc/pf.conf # Variables # ext_if should be set to the hosts external NIC ext_if = "vtnet0" jail_if = "lo1" jail_net = $jail_if:network # NAT allows the jails to access the external network nat on $ext_if from $jail_net to any -> ($ext_if) # Redirect traffic on port 80 to the web server jail # Add similar rules for additional jails rdr pass on $ext_if inet proto tcp to port 80 -> 192.0.2.10 Reboot to activate the network changes ZFS The best way to use ZFS on a VPS is to attach block storage as a new disk. If block storage is not available, you can optionally use a file as the ZFS device. Enable and start ZFS. sysrc zfs_enable="YES" service zfs start ZFS using Block storage List the available disks. If you are using a VPS, the block store will probably be the second disk. geom disk list Create a ZFS pool named jailstore. zpool create jailstore /dev/vtbd1 ZFS using a file Create the ZFS file. dd if=/dev/zero of=/zfsfile bs=1M count=4096 Create a ZFS pool named jailstore. zpool create jailstore /zfsfile Install iocage the easy way pkg install py36-iocage Skip to "Using iocage" Install iocage the hard way Swap file Smaller servers may not have enough RAM to build iocage. If needed, create a swap file and reboot. dd if=/dev/zero of=/swapfile bs=1M count=1024 echo 'swapfile="/swapfile"' >> /etc/rc.conf reboot Install some build dependencies pkg install subversion python36 git-lite libgit2 py36-pip Building iocage requires the FreeBSD source. svn checkout https://svn.freebsd.org/base/releng/11.1 /usr/src Get the latest FreeBSD ports tree. portsnap fetch portsnap extract build iocage. cd /usr/ports/sysutils/iocage/ make install Using iocage iocage activate jailstore iocage fetch iocage create -n www ip4_addr="lo1|192.0.2.10/24" -r 11.1-RELEASE iocage start www iocage console www Once you have a shell inside the jail, install and start Apache. pkg install apache24 sysrc apache24_enable="yes" service apache24 start Port 80 on the jail will now be accessible on the hosts IP address. Multiple jails. Additional jails can be installed using the example above. Install the new jail with the iocage create command , but use a different IP address Expose the new jail to the network by adding additional rules to pf.conf. iXsystems SNIA Persistent Memory Summit 2018 Report New FreeBSD Code of Conduct The FreeBSD Project is inclusive. We want the FreeBSD Project to be a venue where people of all backgrounds can work together to make the best operating system, built by a strong commun

Feb 21, 20181h 43m

233: High on ZFS

We explain the physics behind ZFS, DTrace switching to the GPL, Emacs debugging, syncookies coming to PF & FreeBSD’s history on EC2. This episode was brought to you by Headlines 128 bit storage: Are you high? For people who have heard about ZFS boiling oceans and wonder where that is coming from, we dug out this old piece from 2004 on the blog of ZFS co-creator Jeff Bonwick, originally from the Sun website. 64 bits would have been plenty ... but then you can't talk out of your ass about boiling oceans then, can you? Well, it's a fair question. Why did we make ZFS a 128-bit storage system? What on earth made us think it's necessary? And how do we know it's sufficient? Let's start with the easy one: how do we know it's necessary? Some customers already have datasets on the order of a petabyte, or 250 bytes. Thus the 64-bit capacity limit of 264 bytes is only 14 doublings away. Moore's Law for storage predicts that capacity will continue to double every 9-12 months, which means we'll start to hit the 64-bit limit in about a decade. Storage systems tend to live for several decades, so it would be foolish to create a new one without anticipating the needs that will surely arise within its projected lifetime. If 64 bits isn't enough, the next logical step is 128 bits. That's enough to survive Moore's Law until I'm dead, and after that, it's not my problem. But it does raise the question: what are the theoretical limits to storage capacity? Although we'd all like Moore's Law to continue forever, quantum mechanics imposes some fundamental limits on the computation rate and information capacity of any physical device. In particular, it has been shown that 1 kilogram of matter confined to 1 liter of space can perform at most 1051 operations per second on at most 1031 bits of information [see Seth Lloyd, "Ultimate physical limits to computation." Nature 406, 1047-1054 (2000)]. A fully-populated 128-bit storage pool would contain 2128 blocks = 2137 bytes = 2140 bits; therefore the minimum mass required to hold the bits would be (2140 bits) / (1031 bits/kg) = 136 billion kg. That's a lot of gear. To operate at the 1031 bits/kg limit, however, the entire mass of the computer must be in the form of pure energy. By E=mc2, the rest energy of 136 billion kg is 1.2x1028 J. The mass of the oceans is about 1.4x1021 kg. It takes about 4,000 J to raise the temperature of 1 kg of water by 1 degree Celcius, and thus about 400,000 J to heat 1 kg of water from freezing to boiling. The latent heat of vaporization adds another 2 million J/kg. Thus the energy required to boil the oceans is about 2.4x106 J/kg * 1.4x1021 kg = 3.4x1027 J. Thus, fully populating a 128-bit storage pool would, literally, require more energy than boiling the oceans. Best part of all: you don’t have to understand any of this to use ZFS. Rest assured that you won’t hit any limits with that filesystem for a long time. You still have to buy bigger disks over time, though... *** dtrace for Linux, Oracle relicenses dtrace At Fosdem we had a talk on dtrace for linux in the Debugging Tools devroom. Not explicitly mentioned in that talk, but certainly the most exciting thing, is that Oracle is doing a proper linux kernel port: commit e1744f50ee9bc1978d41db7cc93bcf30687853e6 Author: Tomas Jedlicka <[email protected]> Date: Tue Aug 1 09:15:44 2017 -0400 dtrace: Integrate DTrace Modules into kernel proper This changeset integrates DTrace module sources into the main kernel source tree under the GPLv2 license. Sources have been moved to appropriate locations in the kernel tree. That is right, dtrace dropped the CDDL and switched to the GPL! The user space code dtrace-utils and libdtrace-ctf (a combination of GPLv2 and UPL) can be found on the DTrace Project Source Control page. The NEWS file mentions the license switch (and that it is build upon elfutils, which I personally was pleased to find out). The kernel sources (GPLv2+ for the core kernel and UPL for the uapi) are slightly harder to find because they are inside the uek kernel source tree, but following the above commit you can easily get at the whole linux kernel dtrace directory. The UPL is the Universal Permissive License, which according to the FSF is a lax, non-copyleft license that is compatible with the GNU GPL. Thank you Oracle for making everyone’s life easier by waving your magic relicensing wand! Now there is lots of hard work to do to actually properly integrate this. And I am sure there are a lot of technical hurdles when trying to get this upstreamed into the mainline kernel. But that is just hard work. Which we can now start collaborating on in earnest. Like systemtap and the Dynamic Probes (dprobes) before it, dtrace is a whole system observability tool combining tracing, profiling and probing/debugging techniques. Something the upstream linux kernel hackers don’t always appreciate when presented as one large s

Feb 14, 20181h 50m

232: FOSDEM 2018

We talk about our recent trip to FOSDEM, we discuss the pros and cons of permissive licensing, cover the installation of OpenBSD on a dedibox with full-disk encryption, the new Lumina guide repository, and we explain ZFS vs. OpenZFS. This episode was brought to you by Headlines [FOSDEM Trip report] Your BSDNow hosts were both at FOSDEM in Brussels, Belgium over the weekend. On the friday before FOSDEM, we held a FreeBSD devsummit (3rd consecutive year), sponsored by the FreeBSD Foundation and organized by Benedict (with the help from Kristof Provost, who did it in previous years but could not make it this year). We had 21 people attend, a good mixture of FreeBSD committers (mostly ports) and guests. After introductions, we collected topics and discussed various topics, including a new plan for a future FreeBSD release roadmap (more frequent releases, so that features from HEAD can be tried out earlier in RELEASES). The devsummit concluded with a nice dinner in a nearby restaurant. On Saturday, first day of FOSDEM, we set up the FreeBSD Foundation table with flyers, stickers, FreeBSD Journal print editions, and a small RPI 3 demo system that Deb Goodkin brought. Our table was located next to the Illumos table like last year. This allowed us to continue the good relationship that we have with the Illumos people and Allan helped a little bit getting bhyve to run on Illumos with UEFI. Meanwhile, our table was visited by a lot of people who would ask questions about FreeBSD, take info material, or talk about their use cases. We were busy refilling the table throughout the day and luckily, we had many helpers at the table. Some items we had ran out in the early afternoon, an indicator of how popular they were. Saturday also featured a BSD devroom, organized by Rodrigo Osorio. You can find the list of talks and the recordings on the BSD Devroom schedule. The room was very crowded and popular. Deb Goodkin gave the opening talk with an overview of what the Foundation is doing to change the world. Other speakers from various BSD projects presented their talks after that with a range of topics. Among them, Allan gave his talk about ZFS: Advanced Integration, while Benedict presented his Reflections on Teaching a Unix Class With FreeBSD. Sunday was just as busy on the FreeBSD table as Saturday and we finally ran out of stickers and some other goodies. We were happy with the results of the two days. Some very interesting conversations at the table about FreeBSD took place, some of which we’re going to follow up afterwards. Check out the FOSDEM schedule as many talk recordings are already available, and especially the ones from the BSD devroom if you could not attend the conference. We would like to thank everyone who attended the FreeBSD devsummit, who helped out at the FreeBSD table and organized the BSD devroom. Also, thanks to all the speakers, organizers, and helping hands making FOSDEM another success this year. *** NetBSD kernel wscons IOCTL vulnerable bug class I discovered this bug class during the InfoSect public code review session we ran looking specifically at the NetBSD kernel. I found a couple of these bugs and then after the session was complete, I went back and realised the same bug was scattered in other drivers. In total, 17 instances of this vulnerability and its variants were discovered. In all fairness, I came across this bug class during my kernel audits in 2002 and most instances were patched. It just seems there are more bugs now in NetBSD while OpenBSD and FreeBSD have practically eliminated them. See slide 41 in http://www.blackhat.com/presentations/bh-usa-03/bh-us-03-cesare.pdf for exactly the same bug (class) 16 years ago. The format of the this blog post is as follows: Introduction Example of the Bug Class How to Fix How to Detect Automatically with Coccinelle More Bugs Conclusion These source files had bugs ./dev/tc/tfb.c ./dev/ic/bt485.c ./dev/pci/radeonfb.c ./dev/ic/sti.c ./dev/sbus/tcx.c ./dev/tc/mfb.c ./dev/tc/sfb.c ./dev/tc/stic.c ./dev/tc/cfb.c ./dev/tc/xcfb.c ./dev/tc/sfbplus.c ./arch/arm/allwinner/awin_debe.c ./arch/arm/iomd/vidcvideo.c ./arch/pmax/ibus/pm.c ./dev/ic/igfsb.c ./dev/ic/bt463.c ./arch/luna68k/dev/lunafb.c Reporting of the bugs was easy. In less than a week from reporting the specific instances of each bug, patches were committed into the mainline kernel. Thanks to Luke Mewburn from NetBSD for coming to the code review session at InfoSect and coordinating with the NetBSD security team. The patches to fix these issues are in NetBSD: https://mail-index.netbsd.org/source-changes/2018/01/24/msg091428.html "Permissive licensing is wrong!” – Is it? A few weeks ago I’ve been attacked by some GNU zealots on a German tech site after speaking in favor of permissive licenses. Unfortunately a discussion was not possible there because that would require the will to actually communicate instead of simply accusing the other side of vile motives. Since I actually do care about thi

Feb 7, 20181h 35m

231: Unix Architecture Evolution

We cover an interview about Unix Architecture Evolution, another vBSDcon trip report, how to teach an old Unix about backspace, new NUMA support coming to FreeBSD, and stack pointer checking in OpenBSD. This episode was brought to you by Headlines Unix Architecture Evolution from the 1970 PDP-7 to the 2017 FreeBSD Q: Could you briefly introduce yourself? I’m a professor of software engineering, a programmer at heart, and a technology author. Currently I’m also the editor in chief of the IEEE Software magazine. I recently published the book Effective Debugging, where I detail 66 ways to debug software and systems. Q: What will your talk be about, exactly? I will describe how the architecture of the Unix operating system evolved over the past half century, starting from an unnamed system written in PDP-7 assembly language and ending with a modern FreeBSD system. My talk is based, first, on a GitHub repository where I tried to record the system’s history from 1970 until today and, second, on the evolution of documented facilities (user commands, system calls, library functions) across revisions. I will thus present the early system’s defining architectural features (layering, system calls, devices as files, an interpreter, and process management) and the important ones that followed in subsequent releases: the tree directory structure, user contributed code, I/O redirection, the shell as a user program, groups, pipes, scripting, and little languages. Q: Why this topic? Unix stands out as a major engineering breakthrough due to its exemplary design, its numerous technical contributions, its impact, its development model, and its widespread use. Furthermore, the design of the Unix programming environment has been characterized as one offering unusual simplicity, power, and elegance. Consequently, there are many lessons that we can learn by studying the evolution of the Unix architecture, which we can apply to the design of new systems. I often see modern systems that suffer from a bloat of architectural features and a lack of clear form on which functionality can be built. I believe that many of the modern Unix architecture defining features are excellent examples of what we should strive toward as system architects. Q: What do you hope to accomplish by giving this talk? What do you expect? I’d like FOSDEM attendees to leave the talk with their mind full with architectural features of timeless quality. I want them to realize that architectural elegance isn’t derived by piling design patterns and does not need to be expensive in terms of resources. Rather, beautiful architecture can be achieved on an extremely modest scale. Furthermore, I want attendees to appreciate the importance of adopting flexible conventions rather than rigid enforcement mechanisms. Finally, I want to demonstrate through examples that the open source culture was part of Unix from its earliest days. Q: What are the most significant milestones in the development of Unix? The architectural development of Unix follows a path of continuous evolution, albeit at a slowing pace, so I don’t see here the most important milestones. I would however define as significant milestones two key changes in the way Unix was developed. The first occurred in the late 1970s when significant activity shifted from a closely-knit team of researchers at the AT&T Bell Labs to the Computer Science Research Group in the University of California at Berkeley. This opened the system to academic contributions and growth through competitive research funding. The second took place in the late 1980s and the 1990s when Berkeley open-sourced the the code it had developed (by that time a large percentage of the system) and enthusiasts built on it to create complete open source operating system distributions: 386BSD, and then FreeBSD, NetBSD, OpenBSD, and others. Q: In which areas has the development of Unix stalled? The data I will show demonstrate that there were in the past some long periods where the number of C library functions and system calls remained mostly stable. Nowadays there is significant growth in the number of all documented facilities with the exception of file formats. I’m looking forward to a discussion regarding the meaning of these growth patterns in the Q&A session after the talk. Q: What are the core features that still link the 1970 PDP-7 system to the latest FreeBSD 11.1 release, almost half a century apart? Over the past half-century the Unix system has grown by four orders of magnitude from a few thousand lines of code to many millions. Nevertheless, looking at a 1970s architecture diagram and a current one reveals that the initial architectural blocks are still with us today. Furthermore, most system calls, user programs, and C library functions of that era have survived until today with essentially similar functionality. I’ve even found in modern FreeBSD some lines of code that have survived unchanged for 40 years. Q: Can we still add innovati

Feb 1, 20181h 24m

230: Your questions, Part III

We provide you with updates to Spectre and Meltdown from various BSD projects, a review of TrueOS from Linux, how to set up FreeBSD on ThinkPad x240, and a whole bunch of beastie bits. This episode was brought to you by Headlines KPTI patch lands in FreeBSD -current After a heroic effort by Konstantin Belousov [email protected], the first meltdown patch has landed in FreeBSD This creates separate page tables for the Kernel and userland, and switches between them when executions enters the kernel, and when it returns to userland It is currently off by default, but you are encouraged to test it, so it can be merged back to the release branches. Set vm.pmap.pti=1 in /boot/loader.conf The existing implementation of PCID (process-context identifiers), is not compatible with the new PTI code, and is disabled when PTI is enabled, decreasing performance. A future patch will use PCID in a way that is compatible with PTI. PCID allows the OS to annotate memory mappings to specific processes, so that they can be flushed selectively, and so that they are only used when in the context of that application. Once the developers are relatively confident in the correctness of the code that has landed in -current, it will be ported back to FreeBSD 10 and 11, and released as a security advisory. Apparently porting back to FreeBSD 11 only has some relatively simple merge conflicts, but 10 will be more work. Former FreeBSD Security Officer Dag-Erling Smørgrav has created a meltdown testing and PoC tool that you can use to check your system. It is not finished yet, and doesn’t seem to work with newer processors (haswell and newer). The first partial mitigation for Spectre variant 2 for bhyve on AMD64 has also been committed The latest information is always available on the FreeBSD Wiki *** Some thoughts on Spectre and Meltdown Colin Percival breaks down how these vulnerabilities work, with same nice analogies What is a side channel: I want to know when my girlfriend's passport expires, but she won't show me her passport (she complains that it has a horrible photo) and refuses to tell me the expiry date. I tell her that I'm going to take her to Europe on vacation in August and watch what happens: If she runs out to renew her passport, I know that it will expire before August; while if she doesn't get her passport renewed, I know that it will remain valid beyond that date. Her desire to ensure that her passport would be valid inadvertently revealed to me some information: Whether its expiry date was before or after August. Spectre Variant 1: I tell my girlfriend that I'm going to take her on vacation in June, but I don't tell her where yet; however, she knows that it will either be somewhere within Canada (for which she doesn't need a passport, since we live in Vancouver) or somewhere in Europe. She knows that it takes time to get a passport renewed, so she checks her passport and (if it was about to expire) gets it renewed just in case I later reveal that I'm going to take her to Europe. If I tell her later that I'm only taking her to Ottawa — well, she didn't need to renew her passport after all, but in the meantime her behaviour has already revealed to me whether her passport was about to expire. This is what Google refers to "variant 1" of the Spectre vulnerability: Even though she didn't need her passport, she made sure it was still valid just in case she was going to need it. Spectre Variant 2: I spend a week talking about how Oxford is a wonderful place to visit and I really enjoyed the years I spent there, and then I tell her that I want to take her on vacation. She very reasonably assumes that — since I've been talking about Oxford so much — I must be planning on taking her to England, and runs off to check her passport and potentially renew it... but in fact I tricked her and I'm only planning on taking her to Ottawa. Meltdown: I tell my girlfriend that I want to take her to the Korean peninsula. She knows that her passport is valid for long enough; but she immediately runs off to check that her North Korean visa hasn't expired. Why does she have a North Korean visa, you ask? Good question. She doesn't — but she runs off to check its expiry date anyway! Because she doesn't have a North Korean visa, she (somehow) checks the expiry date on someone else's North Korean visa, and then (if it is about to expire) runs out to renew it — and so by telling her that I want to take her to Korea for a vacation I find out something she couldn't have told me even if she wanted to. Final thoughts on vulnerability disclosure The way these issues were handled was a mess; frankly, I expected better of Google, I expected better of Intel, and I expected better of the Linux community. When I found that Hyper-Threading was easily exploitable, I spent five months notifying the security community and preparing everyone for my announcement of the vulnerability; but when

Jan 24, 20181h 56m

229: The Meltdown of Spectre

We review Meltdown and Spectre responses from various BSD projects, show you how to run CentOS with bhyve, GhostBSD 11.1 is out, and we look at the case against the fork syscall. This episode was brought to you by Headlines More Meltdown Much has been happened this week, but before we get into a status update of the various mitigations on the other BSDs, some important updates: Intel has recalled the microcode update they issued on January 8th. It turns out this update can cause Haswell and Broadwell based systems to randomly reboot, with some frequency. AMD has confirmed that its processors are vulnerable to both variants of Spectre, and the the fix for variant #2 will require a forthcoming microcode update, in addition to OS level mitigations Fujitsu has provided a status report for most of its products, including SPARC hardware The Register of course has some commentary If new code is needed, Intel will need to get it right: the company already faces numerous class action lawsuits. Data centre operators already scrambling to conduct unplanned maintenance will not be happy about the fix reducing stability. AMD has said that operating system patches alone will address the Spectre bounds check bypass bug. Fixing Spectre’s branch target injection flaw will require firmware fixes that AMD has said will start to arrive for Ryzen and EPYC CPUs this week. The Register has also asked other server vendors how they’re addressing the bugs. Oracle has patched its Linux, but has told us it has “No comment/statement on this as of now” in response to our query about its x86 systems, x86 cloud, Linux and Solaris on x86. The no comment regarding Linux is odd as fixes for Oracle Linux landed here on January 9th. SPARC-using Fujitsu, meanwhile, has published advice (PDF) revealing how it will address the twin bugs in its servers and PCs, and also saying its SPARC systems are “under investigation”. Response from OpenBSD: 'Meltdown, aka "Dear Intel, you suck"' Theo de Raadt's response to Meltdown That time in 2007 when Theo talked about how Intel x86 had major design problems in their chips OpenBSD gets a Microcode updater Response from Dragonfly BSD: The longer response in four commits One Two Three Four Even more Meltdown DragonflyBSD master now has full IBRS and IBPB support IBRS (Indirect Branch Restricted Speculation): The x86 IBRS feature requires corresponding microcode support. It mitigates the variant 2 vulnerability. If IBRS is set, near returns and near indirect jumps/calls will not allow their predicted target address to be controlled by code that executed in a less privileged prediction mode before the IBRS mode was last written with a value of 1 or on another logical processor so long as all RSB entries from the previous less privileged prediction mode are overwritten. Speculation on Skylake and later requires these patches ("dynamic IBRS") be used instead of retpoline. If you are very paranoid or you run on a CPU where IBRS=1 is cheaper, you may also want to run in "IBRS always" mode. IBPB (Indirect Branch Prediction Barrier): Setting of IBPB ensures that earlier code's behavior does not control later indirect branch predictions. It is used when context switching to new untrusted address space. Unlike IBRS, IBPB is a command MSR and does not retain its state. DragonFlyBSD's Meltdown Fix Causing More Slowdowns Than Linux NetBSD HOTPATCH() NetBSD SVS (Separate Virtual Space) Running CentOS with Bhyve With the addition of UEFI in FreeBSD (since version 11), users of bhyve can use the UEFI boot loader instead of the grub2-bhyve port for booting operating systems such as Microsoft Windows, Linux and OpenBSD. The following page provides information necessary for setting up bhyve with UEFI boot loader support: https://wiki.freebsd.org/bhyve/UEFI Features have been added to vmrun.sh to make it easier to setup the UEFI boot loader, but the following is required to install the UEFI firmware pkg: # pkg install -y uefi-edk2-bhyve With graphical support, you can use a vnc client like tigervnc, which can be installed with the following command: # pkg install -y tigervnc In the case of most corporate or government environments, the Linux of choice is RHEL, or CentOS. Utilizing bhyve, you can test and install CentOS in a bhyve VM the same way you would deploy a Linux VM in production. The first step is to download the CentOS iso (for this tutorial I used the CentOS minimal ISO): http://isoredirect.centos.org/centos/7/isos/x86_64/CentOS-7-x86_64-Minimal-1708.iso I normally use a ZFS Volume (zvol) when running bhyve VMs. Run the following commands to create a zvol (ensure you have enough disk space to perform these operations): # zfs create -V20G -o volmode=dev zroot/centos0 (zroot in this case is the zpool I am using) Similar to my previous post about vmrun.sh, you need certain items to be configured on FreeBSD in order to use bhyve. The following commands are necessary to get t

Jan 17, 20181h 48m

228: The Spectre of Meltdown

We review the information about Spectre & Meltdown thus far, we look at NetBSD memory sanitizer progress, Postgres on ZFS & show you a bit about NomadBSD. This episode was brought to you by Headlines Meltdown Spectre Official Site Kernel-memory-leaking Intel processor design flaw forces Linux, Windows redesign Intel’s official response The Register mocks intels response with pithy annotations Intel’s Analysis PDF XKCD Response from FreeBSD FreeBSD's patch WIP Why Raspberry Pi isn’t vulnerable to Spectre or Meltdown Xen mitigation patches Overview of affected FreeBSD Platforms/Architectures Groff's response ##### We’ll cover OpenBSD, NetBSD, and DragonflyBSD’s responses in next weeks episode. *** ###The LLVM Memory Sanitizer support work in progress > In the past 31 days, I've managed to get the core functionality of MSan to work. This is an uninitialized memory usage detector. MSan is a special sanitizer because it requires knowledge of every entry to the basesystem library and every entry to the kernel through public interfaces. This is mandatory in order to mark memory regions as initialized. Most of the work has been done directly for MSan. However, part of the work helped generic features in compiler-rt. Sanitizers > Changes in the sanitizer are listed below in chronological order. Almost all of the changes mentioned here landed upstream. A few small patches were reverted due to breaking non-NetBSD hosts and are rescheduled for further investigation. I maintain these patches locally and have moved on for now to work on the remaining features. NetBSD syscall hooks > I wrote a large patch (815kb!) adding support for NetBSD syscall hooks for use with sanitizers. NetBSD ioctl(2) hooks > Similar to the syscall hooks, there is need to handle every ioctl(2) call. I've created the needed patch, this time shorter - for less than 300kb. New patches still pending for upstream review > There are two corrections that I've created, and they are still pending upstream for review: Add MSan interceptor for fstat(2)](https://reviews.llvm.org/D41637) Correct the setitimer interceptor on NetBSD)](https://reviews.llvm.org/D41502) > I've got a few more local patches that require cleanup before submitting to review. NetBSD basesystem corrections Sanitizers in Go The MSan state as of today Solaris support in sanitizers > I've helped the Solaris team add basic support for Sanitizers (ASan, UBsan). This does not help NetBSD directly, however indirectly it improves the overall support for non-Linux hosts and helps to catch more Linuxisms in the code. Plan for the next milestone > I plan to continue the work on MSan and correct sanitizing of the NetBSD basesystem utilities. This mandates me to iterate over the basesystem libraries implementing the missing interceptors and correcting the current support of the existing ones. My milestone is to build all src/bin programs against Memory Sanitizer and when possible execute them cleanly. This work was sponsored by The NetBSD Foundation. The NetBSD Foundation is a non-profit organization and welcomes any donations to help us continue funding projects and services to the open-source community. Please consider visiting the following URL, and chip in what you can: http://netbsd.org/donations/#how-to-donate *** ##News Roundup ###MWL’s 2017 Wrap-Up > The obvious place to start is my 2016 wrap-up post](https://blather.michaelwlucas.com/archives/2822), where I listed goals for 2017. As usual, these goals were wildly delusional. > The short answer is, my iron was back up to normal. My writing speed wasn’t, though. I’d lost too much general health, and needed hard exercise to recover it. Yes, writing requires physical endurance. Maintaining that level of concentration for several hours a day demands a certain level of blood flow to the brain. I could have faked it in a day job, but when self-employed as an artist? Not so much. > Then there’s travel. I did my usual BSDCan trip, plus two educational trips to Lincoln City, Oregon. The current political mayhem convinced me that if I wanted to hit EuroBSDCon any time in the next few years, I should do it in the very near future. So I went to Paris, where I promptly got pickpocketed. (Thankfully, they didn’t get my passport.) I was actively writing the third edition of Absolute FreeBSD, so I visited BSDCam in Cambridge to get the latest information and a sense of where FreeBSD was going. I also did weekends at Kansas LinuxFest (because they asked and paid for my trip) and Penguicon. > (Because people will ask: why EuroBSDCon and not AsiaBSDCon? A six-hour transatlantic flight requires that I take a substantial dose of heavy-grade tranquilizers. I’m incapable of making intelligent decisions while on those drugs, or for several hours afterward. They don’t last long enough for twelve-hour flight to Japan, so I need to be accompanied by someone qualified to tell me when I need to take

Jan 10, 20181h 51m

227: The long core dump

We walk through dumping a PS4 kernel in only 6 days, tell you the news that NetBSD 7.1.1 has been released, details on how to run FreeBSD on a Thinkpad T470, and there’s progress in OpenBSD’s pledge. This episode was brought to you by Headlines NetBSD 7.1.1 released The NetBSD Project is pleased to announce NetBSD 7.1.1, the first security/critical update of the NetBSD 7.1 release branch. It represents a selected subset of fixes deemed important for security or stability reasons. Complete source and binaries for NetBSD 7.1.1 are available for download at many sites around the world. A list of download sites providing FTP, AnonCVS, and other services may be found at https://www.NetBSD.org/mirrors/. We encourage users who wish to install via ISO or USB disk images to download via BitTorrent by using the torrent files supplied in the images area. A list of hashes for the NetBSD 7.1.1 distribution has been signed with the well-connected PGP key for the NetBSD Security Officer: https://ftp.NetBSD.org/pub/NetBSD/security/hashes/NetBSD-7.1.1_hashes.asc NetBSD is free. All of the code is under non-restrictive licenses, and may be used without paying royalties to anyone. Free support services are available via our mailing lists and website. Commercial support is available from a variety of sources. More extensive information on NetBSD is available from our website: [NetBSD website](www.NetBSD.org) +Changes Between 7.1 and 7.1.1 Below is an abbreviated list of changes in this release. The complete list can be found in the CHANGES-7.1.1 file in the top level directory of the NetBSD 7.1.1 release tree. Security Advisory Fixes The following security advisories were fixed: NetBSD-SA2017-004 buffer overflow via cmap for 4 graphics drivers. NetBSD-SA2017-005 x86: vulnerabilities in context handling. NetBSD-SA2017-006 Vnode reference leak in the openat system call. NetBSD-SA2018-001 Several vulnerabilities in context handling NetBSD-SA2018-002 Local DoS in virecover Note: Advisories prior to NetBSD-SA2017-004 do not affect NetBSD 7.1.1. Userland changes dhcrelay(8): Fix bug that prevented proper operation when run in the background. Heimdal: Update to 7.1. Fix CVE-2017-11103. mtree(8): Don't modify strings stored in hash, otherwise filling up of directory hierarchy stops if the same hash value occurs in directory and leaf. ping(8): Fix cksum calculation for clearing the cached route. resize_ffs(8): Fix numerous overflow errors which can lead to superblock corruption on large filesystems. rtadvd(8): Fix the default value of rltime. PR bin/51994. Update BIND to 9.10.5-P2. Update expat to 2.2.1. Update ntp to 4.2.8p10. Update root.cache to 2017102400. Update tzdata to 2017c. vi(1): Don't garble display when when resizing nvi in xterm. wpa_supplicant/hostapd: Update to 2.6. Apply fixes for CVEs 2017-13077 through 2017-13082 and CVEs 2017-13086 through 2017-13088. X: Apply fixes for CVEs 2017-12176 through 2017-12187, 2017-10971, 2017-10972, 2017-13722, 2017-13720, 2017-16611, and 2017-16612. *** ###Dumping a PS4 Kernel in "Only" 6 Days > What if a secure device had an attacker-viewable crashdump format? What if that same device allowed putting arbitrary memory into the crashdump? Amazingly, the ps4 tempted fate by supporting both of these features! Let’s see how that turned out… Crashdumps on PS4 The crash handling infrastructure of the ps4 kernel is interesting for 2 main reasons: It is ps4-specific code (likely to be buggy) If the crashdump can be decoded, we will gain very useful info for finding bugs and creating reliable exploits On a normal FreeBSD system, a kernel panic will create a dump by calling kern_reboot with the RB_DUMP flag. This then leads to doadump being called, which will dump a rather tiny amount of information about the kernel image itself to some storage device. On ps4, the replacement for doadump is mdbg_run_dump, which can be called from panic or directly from trap_fatal. The amount of information stored into the dump is gigantic by comparison - kernel state for all process, thread, and vm objects are included, along with some metadata about loaded libraries. Other obvious changes from the vanilla FreeBSD method are that the mdbg_run_dump encodes data recorded into the dump on a field-by-field basis and additionally encrypts the resulting buffer before finally storing it to disk. Dumping Anything Let’s zoom in to a special part of mdbg_run_dump - where it iterates over all process’ threads and tries to dump some pthread state: dumpstate is a temporary buffer which will eventually make it into the crashdump. To summarize, sysdump__internal_call_readuser can be made to function as a read-anywhere oracle. This is because fsbase will point into our (owned) webkit process’ usermode address space. Thus, even without changing the actual fsbase value, we may freely change the value of tcb_thread, which is stored at fsbase + 0x10. Further, sysdump__internal_call_readuser will happily read fr

Jan 3, 20181h 31m

226: SSL: Santa’s Syscall List

We read the FreeBSD Q3 status report, explore good and bad syscalls, list GOG Games for OpenBSD, and show you what devmatch can do. This episode was brought to you by Headlines FreeBSD Q3 Status Report 2017 FreeBSD Team Reports FreeBSD Release Engineering Team Ports Collection The FreeBSD Core Team The FreeBSD Foundation Projects FreeBSD CI Kernel Intel 10G iflib Driver Update Intel iWARP Support pNFS Server Plan B Architectures AMD Zen (family 17h) support Userland Programs Updates to GDB Ports FreeBSDDesktop OpenJFX 8 Puppet Documentation Absolute FreeBSD, 3rd Edition Manual Pages Third-Party Projects The nosh Project ####FreeBSD Foundation Q4 Update *** ###11 syscalls that rock the world 0. read > You cannot go wrong with a read. You can barely EFAULT it! On Linux amd64 it is syscall zero. If all its arguments are zero it returns zero. Cool! 1. pipe > The society for the preservation of historic calling conventions is very fond of pipe, as in many operating systems and architectures it preserves the fun feature of returning both of the file descriptors as return values. At least Linux MIPS does, and NetBSD does even on x86 and amd64. Multiple return values are making a comeback in languages like Lua and Go, but C has always had a bit of a funny thing about them, but they have long been supported in many calling conventions, so let us use them in syscalls! Well, one syscall. 2. kqueue > When the world went all C10K on our ass, and scaleable polling was a thing, Linux went epoll, the BSDs went kqueue and Solaris went /dev/poll. The nicest interface was kqueue, while epoll is some mix of edge and level triggered semantics and design errors so bugs are still being found. 3. unshare > Sounds like a selfish syscall, but this generous syscall call is the basis of Linux namespaces, allowing a process to isolate its resources. Containers are built from unshares. 4. setns > If you liked unshare, its younger but cooler friend takes file descriptors for namespaces. Pass it down a unix socket to another process, or stash it for later, and do that namespace switching. All the best system calls take file descriptors. 5. execveat > Despite its somewhat confusing name (FreeBSD has the saner fexecve, but other BSDs do not have support last time I checked), this syscall finally lets you execute a program just given a file descriptor for the file. I say finally, as Linux only implemented this in 3.19, which means it is hard to rely on it (yeah, stop using those stupid old kernels folks). Before that Glibc had a terrible userspace implementation that is basically useless. Perfect for creating sandboxes, as you can sandbox a program into a filesystem with nothing at all in, or with a totally controlled tree, by opening the file to execute before chroot or changing the namespace. 6. pdfork > Too cool for Linux, you have to head out to FreeBSD for this one. Like fork, but you get a file descriptor for the process not a pid. Then you can throw it in the kqueue or send it to another process. Once you have tried process descriptors you will never go back. 7. signalfd > You might detect a theme here, but if you have ever written traditional 1980s style signal handlers you know how much they suck. How about turning your signals into messages that you can read on, you guessed it, file descriptors. Like, usable. 8. wstat > This one is from Plan 9. It does the opposite of stat and writes the same structure. Simples. Avoids having chmod, chown, rename, utime and so on, by the simple expedient of making the syscall symmetric. Why not? 9. clonefile > The only cool syscall on OSX, and only supported on the new APFS filesystem. Copies whole files or directories on a single syscall using copy on write for all the data. Look on my works, copy_file_range and despair. 10. pledge > The little sandbox that worked. OpenBSD only here, they managed to make a simple sandbox that was practical for real programs, like the base OpenBSD system. Capsicum form FreeBSD (and promised for Linux for years but no sign) is a lovely design, and gave us pdfork, but its still kind of difficult and intrusive to implement. Linux has, well, seccomp, LSMs, and still nothing that usable for the average program. ###Eleven syscalls that suck 0. ioctl > It can‘t decide if it‘s arguments are integers, strings, or some struct that is lost in the midst of time. Make up your mind! Plan 9 was invented to get rid of this. 1. fcntl > Just like ioctl but for some different miscellaneous operations, because one miscelleny is not enough. 2. tuxcall > Linux put a web server in the kernel! To win a benchmark contest with Microsoft! It had it‘s own syscall! My enum tux_reactions are YUK! Don‘t worry though, it was a distro patch (thanks Red Hat!) and never made it upstream, so only the man page and reserved number survive to taunt you and remind you that the path of the righteous is beset by premature optmization! 3. io_setup > The Linux asy

Dec 27, 20172h 7m

225: The one true OS

TrueOS stable 17.12 is out, we have an OpenBSD workstation guide for you, learnings from the PDP-11, FreeBSD 2017 Releng recap and Duo SSH. This episode was brought to you by Headlines TrueOS stable release 17.12 We are pleased to announce a new release of the 6-month STABLE version of TrueOS! This release cycle focused on lots of cleanup and stabilization of the distinguishing features of TrueOS: OpenRC, boot speed, removable-device management, SysAdm API integrations, Lumina improvements, and more. We have also been working quite a bit on the server offering of TrueOS, and are pleased to provide new text-based server images with support for Virtualization systems such as bhyve! This allows for simple server deployments which also take advantage of the TrueOS improvements to FreeBSD such as: Sane service management and status reporting with OpenRC Reliable, non-interactive system update mechanism with fail-safe boot environment support. Graphical management of remote TrueOS servers through SysAdm (also provides a reliable API for administrating systems remotely). LibreSSL for all base SSL support. Base system managed via packages (allows for additional fine-tuning). Base system is smaller due to the removal of the old GCC version in base. Any compiler and/or version may be installed and used via packages as desired. Support for newer graphics drivers and chipsets (graphics, networking, wifi, and more) TrueOS Version 17.12 (2017, December) is now available for download from the TrueOS website. Both the STABLE and UNSTABLE package repositories have also been updated in-sync with each other, so current users only need to follow the prompts about updating their system to run the new release. We are also pleased to announce the availability of TrueOS Sponsorships! If you would like to help contribute to the project financially we now have the ability to accept both one-time donations as well as recurring monthly donations which wil help us advocate for TrueOS around the world. Thank you all for using and supporting TrueOS! Notable Changes: Over 1100 OpenRC services have been created for 3rd-party packages. This should ensure the functionality of nearly all available 3rd-party packages that install/use their own services. The OpenRC services for FreeBSD itself have been overhauled, resulting in significantly shorter boot times. Separate install images for desktops and servers (server image uses a text/console installer) Bhyve support for TrueOS Server Install FreeBSD base is synced with 12.0-CURRENT as of December 4th, 2017 (Github commit: 209d01f) FreeBSD ports tree is synced as of November 30th (pre-FLAVOR changes) Lumina Desktop has been updated/developed from 1.3.0 to 1.4.1 PCDM now supports multiple simultaneous graphical sessions Removable devices are now managed through the “automounter” service. Devices are “announced” as available to the system via *.desktop shortcuts in /media. These shortcuts also contain a variety of optional “Actions” that may be performed on the device. Devices are only mounted while they are being used (such as when browsing via the command line or a file manager). Devices are automatically unmounted as soon as they stop being accessed. Integrated support for all major filesystems (UFS, EXT, FAT, NTFS, ExFAT, etc..) NOTE: The Lumina desktop is the only one which supports this functionality at the present time. The TrueOS update system has moved to an “active” update backend. This means that the user will need to actually start the update process by clicking the “Update Now” button in SysAdm, Lumina, or PCDM (as well as the command-line option). The staging of the update files is still performed automatically by default but this (and many other options) can be easily changed in the “Update Manager” settings as desired. Known Errata: [VirtualBox] Running FreeBSD within a VirtualBox VM is known to occasionally receive non-existent mouse clicks – particularly when using a scroll wheel or two-finger scroll. Quick Links: TrueOS Forums TrueOS Bugs TrueOS Handbook TrueOS Community Chat on Telegram *** OpenBSD Workstation Guide Design Goals User actions should complete instantaneously. While I understand if compiling code and rendering videos takes time, opening programs and moving windows should have no observable delay. The system should use minimalist tools. Corollary: cache data offline when possible. Everything from OpenStreetMaps to StackExchange can be stored locally. No reason to repeatedly hit the internet to query them. This also improves privacy because the initial download is indiscriminate and doesn’t reveal personal queries or patterns of computer activity. No idling program should use a perceptible amount of CPU. Why does CalendarAgent on my Macbook sometimes use 150% CPU for fifteen minutes? Who knows. Why are background ChromeHelpers chugging along at upper-single-digit CPU? I didn’t realize that holding a rendered DOM could be so challenging. Avoid interpreted languages,

Dec 20, 20171h 47m

224: The Bus Factor

We try to answer what happens to an open source project after a developers death, we tell you about the last bootstrapped tech company in Silicon Valley, we have an update to the NetBSD Thread sanitizer, and show how to use use cabal on OpenBSD This episode was brought to you by Headlines Life after death, for code YOU'VE PROBABLY NEVER heard of the late Jim Weirich or his software. But you've almost certainly used apps built on his work. Weirich helped create several key tools for Ruby, the popular programming language used to write the code for sites like Hulu, Kickstarter, Twitter, and countless others. His code was open source, meaning that anyone could use it and modify it. "He was a seminal member of the western world's Ruby community," says Justin Searls, a Ruby developer and co-founder of the software company Test Double. When Weirich died in 2014, Searls noticed that no one was maintaining one of Weirich's software-testing tools. That meant there would be no one to approve changes if other developers submitted bug fixes, security patches, or other improvements. Any tests that relied on the tool would eventually fail, as the code became outdated and incompatible with newer tech. The incident highlights a growing concern in the open-source software community. What happens to code after programmers pass away? Much has been written about what happens to social-media accounts after users die. But it’s been less of an issue among programmers. In part, that’s because most companies and governments relied on commercial software maintained by teams of people. But today, more programs rely on obscure but crucial software like Weirich's. Some open-source projects are well known, such as the Linux operating system or Google's artificial-intelligence framework TensorFlow. But each of these projects depend on smaller libraries of open-source code. And those libraries depend on other libraries. The result is a complex, but largely hidden, web of software dependencies. That can create big problems, as in 2014 when a security vulnerability known as "Heartbleed" was found in OpenSSL, an open-source program used by nearly every website that processes credit- or debit-card payments. The software comes bundled with most versions of Linux, but was maintained by a small team of volunteers who didn't have the time or resources to do extensive security audits. Shortly after the Heartbleed fiasco, a security issue was discovered in another common open-source application called Bash that left countless web servers and other devices vulnerable to attack. There are surely more undiscovered vulnerabilities. Libraries.io, a group that analyzes connections between software projects, has identified more than 2,400 open-source libraries that are used in at least 1,000 other programs but have received little attention from the open-source community. Security problems are only one part of the issue. If software libraries aren't kept up to date, they may stop working with newer software. That means an application that depends on an outdated library may not work after a user updates other software. When a developer dies or abandons a project, everyone who depends on that software can be affected. Last year when programmer Azer Koçulu deleted a tiny library called Leftpad from the internet, it created ripple effects that reportedly caused headaches at Facebook, Netflix, and elsewhere. The Bus Factor The fewer people with ownership of a piece of software, the greater the risk that it could be orphaned. Developers even have a morbid name for this: the bus factor, meaning the number of people who would have to be hit by a bus before there's no one left to maintain the project. Libraries.io has identified about 3,000 open-source libraries that are used in many other programs but have only a handful of contributors. Orphaned projects are a risk of using open-source software, though commercial software makers can leave users in a similar bind when they stop supporting or updating older programs. In some cases, motivated programmers adopt orphaned open-source code. That's what Searls did with one of Weirich’s projects. Weirich's most-popular projects had co-managers by the time of his death. But Searls noticed one, the testing tool Rspec-Given, hadn't been handed off, and wanted to take responsibility for updating it. But he ran into a few snags along the way. Rspec-Given's code was hosted on the popular code-hosting and collaboration site GitHub, home to 67 million codebases. Weirich's Rspec-Given page on GitHub was the main place for people to report bugs or to volunteer to help improve the code. But GitHub wouldn’t give Searls control of the page, because Weirich had not named him before he died. So Searls had to create a new copy of the code, and host it elsewhere. He also had to convince the operators of Ruby Gems, a “package-management system” for distributing co

Dec 13, 20171h 40m

223: Compile once, debug twice

Picking a compiler for debuggability, how to port Rust apps to FreeBSD, what the point of Docker is on FreeBSD/Solaris, another EuroBSDcon recap, and network manager control in OpenBSD This episode was brought to you by Headlines Compile once, Debug twice: Picking a compiler for debuggability, part 1 of 3 An interesting look into why when you try to debug a crash, you can often find all of the useful information has been ‘optimized out’ Have you ever had an assert get triggered only to result in a useless core dump with missing variable information or an invalid callstack? Common factors that go into selecting a C or C++ compiler are: availability, correctness, compilation speed and application performance. A factor that is often neglected is debug information quality, which symbolic debuggers use to reconcile application executable state to the source-code form that is familiar to most software engineers. When production builds of an application fail, the level of access to program state directly impacts the ability for a software engineer to investigate and fix a bug. If a compiler has optimized out a variable or is unable to express to a symbolic debugger how to reconstruct the value of a variable, the engineer’s investigation process is significantly impacted. Either the engineer has to attempt to recreate the problem, iterate through speculative fixes or attempt to perform prohibitively expensive debugging, such as reconstructing program state through executable code analysis. Debug information quality is in fact not proportionally related to the quality of the generated executable code and wildly varies from compiler to compiler. Different compilers emit debug information at varying levels of quality and accuracy. However, certain optimizations will certainly impact any debugger’s ability to generate accurate stack traces or extract variable values. In the above program, the value of argv is extracted and then the program is paused. The ck_pr_load_ptr function performs a read from the region of memory pointed to by argv, in a manner that prevents the compiler from performing optimization on it. This ensures that the memory access occurs and for this reason, the value of argv must be accessible by the time ck_pr_load_ptr is executed. When compiled with gcc, the debugger fails to find the value of the variable. The compiler determines that the value of argv is no longer needed after the ck_pr_load_ptr operation and so doesn’t bother paying the cost of saving the value. Some optimizations generate executable code whose call stack cannot be sufficiently disambiguated to reconcile a call stack that mirrors that of the source program. Two common culprits for this are tail call optimization and basic block commoning. In another example If the program receives a first argument of 1, then function is called with the argument of "a". If the program receives a first argument of 2, then function is called with the argument of "b". However, if we compile this program with clang, the stack traces in both cases are identical! clang informs the debugger that the function f invoked the function("b") branch where x = 2 even if x = 1. Though some optimizations will certainly impact the accuracy of a symbolic debugger, some compilers simply lack the ability to generate debug information in the presence of certain optimizations. One common optimization is induction variable elimination. A variable that’s incremented or decremented by a constant on every iteration of a loop or derived from another variable that follows this pattern, is an induction variable. Coupled with other optimizations, the compiler is then able to generate code that doesn’t actually rely on a dedicated counter variable “i” for maintaining the current offset into “buffer”. As you can see, i is completely optimized out. The compiler determines it doesn’t have to pay the cost of maintaining the induction variable i. It maintains the pointer in the register %rdi. The code is effectively rewritten to something closer to this: So the for loop, changes into a while loop, with a condition of the end of the input We have shown some common optimizations that may get in the way of the debuggability of your application and demonstrated a disparity in debug information quality across two popular compilers. In the next blog post of this series, we will examine how gcc and clang stack up with regards to debug information quality across a myriad of synthetic applications and real world applications. Looking forward to part 2 *** This is how you can port your rust application to FreeBSD This is how you can port your rust application to FreeBSD The FreeBSD Ports Collection is the way almost everyone installs applications (“ports”) on FreeBSD. Like everything else about FreeBSD, it is primarily a volunteer effort. It is important to keep this in mind when reading this document. In FreeBSD, anyone may submit a new port, or volunteer to main

Dec 6, 20171h 51m

222: How Netflix works

We take a look at two-faced Oracle, cover a FAMP installation, how Netflix works the complex stuff, and show you who the patron of yak shaving is. This episode was brought to you by Headlines Why is Oracle so two-faced over open source? Oracle loves open source. Except when the database giant hates open source. Which, according to its recent lobbying of the US federal government, seems to be "most of the time". Yes, Oracle has recently joined the Cloud Native Computing Foundation (CNCF) to up its support for open-source Kubernetes and, yes, it has long supported (and contributed to) Linux. And, yes, Oracle has even gone so far as to (finally) open up Java development by putting it under a foundation's stewardship. Yet this same, seemingly open Oracle has actively hammered the US government to consider that "there is no math that can justify open source from a cost perspective as the cost of support plus the opportunity cost of forgoing features, functions, automation and security overwhelm any presumed cost savings." That punch to the face was delivered in a letter to Christopher Liddell, a former Microsoft CFO and now director of Trump's American Technology Council, by Kenneth Glueck, Oracle senior vice president. The US government had courted input on its IT modernisation programme. Others writing back to Liddell included AT&T, Cisco, Microsoft and VMware. In other words, based on its letter, what Oracle wants us to believe is that open source leads to greater costs and poorly secured, limply featured software. Nor is Oracle content to leave it there, also arguing that open source is exactly how the private sector does not function, seemingly forgetting that most of the leading infrastructure, big data, and mobile software today is open source. Details! Rather than take this counterproductive detour into self-serving silliness, Oracle would do better to follow Microsoft's path. Microsoft, too, used to Janus-face its way through open source, simultaneously supporting and bashing it. Only under chief executive Satya Nadella's reign did Microsoft realise it's OK to fully embrace open source, and its financial results have loved the commitment. Oracle has much to learn, and emulate, in Microsoft's approach. I love you, you're perfect. Now change Oracle has never been particularly warm and fuzzy about open source. As founder Larry Ellison might put it, Oracle is a profit-seeking corporation, not a peace-loving charity. To the extent that Oracle embraces open source, therefore it does so for financial reward, just like every other corporation. Few, however, are as blunt as Oracle about this fact of corporate open-source life. As Ellison told the Financial Times back in 2006: "If an open-source product gets good enough, we'll simply take it. So the great thing about open source is nobody owns it – a company like Oracle is free to take it for nothing, include it in our products and charge for support, and that's what we'll do. "So it is not disruptive at all – you have to find places to add value. Once open source gets good enough, competing with it would be insane... We don't have to fight open source, we have to exploit open source." "Exploit" sounds about right. While Oracle doesn't crack the top-10 corporate contributors to the Linux kernel, it does register a respectable number 12, which helps it influence the platform enough to feel comfortable building its IaaS offering on Linux (and Xen for virtualisation). Oracle has also managed to continue growing MySQL's clout in the industry while improving it as a product and business. As for Kubernetes, Oracle's decision to join the CNCF also came with P&L strings attached. "CNCF technologies such as Kubernetes, Prometheus, gRPC and OpenTracing are critical parts of both our own and our customers' development toolchains," said Mark Cavage, vice president of software development at Oracle. One can argue that Oracle has figured out the exploitation angle reasonably well. This, however, refers to the right kind of exploitation, the kind that even free software activist Richard Stallman can love (or, at least, tolerate). But when it comes to government lobbying, Oracle looks a lot more like Mr Hyde than Dr Jekyll. Lies, damned lies, and Oracle lobbying The current US president has many problems (OK, many, many problems), but his decision to follow the Obama administration's support for IT modernisation is commendable. Most recently, the Trump White House asked for feedback on how best to continue improving government IT. Oracle's response is high comedy in many respects. As TechDirt's Mike Masnick summarises, Oracle's "latest crusade is against open-source technology being used by the federal government – and against the government hiring people out of Silicon Valley to help create more modern systems. Instead, Oracle would app

Nov 29, 20172h 7m

221: BSD in Taiwan

Allan reports on his trip to BSD Taiwan, new versions of Lumina and GhostBSD are here, a bunch of OpenBSD p2k17 hackathon reports. This episode was brought to you by Headlines Allan’s Trip Report from BSD Taiwan BSD TW and Taiwan in general was a fun and interesting experience I arrived Thursday night and took the high speed train to Taipei main station, and then got on the Red line subway to the venue. The dorm rooms were on par with BSDCan, except the mattress was better. I spent Friday with a number of other FreeBSD developers doing touristy things. We went to Taipei 101, the world’s tallest building from 2004 - 2010. It also features the world’s fastest elevator (2004 - 2016), traveling at 60.6 km/h and transporting passengers from the 5th to 89th floor in 37 seconds. We also got to see the “tuned mass damper”, a 660 tonne steel pendulum suspended between the 92nd and 87th floors. This device resists the swaying of the building caused by high winds. There are interesting videos on display beside the damper, of its reaction during recent typhoons and earthquakes. The Taipei 101 building sits just 200 meters from a major fault line. Then we had excellent dumplings for lunch After walking around the city for a few more hours, we retired to a pub to escape the heat of the sunny Friday afternoon. Then came the best part of each day in Taipei, dinner! We continued our efforts to cause a nation wide shortage of dumplings Special thanks to Scott Tsai who took detailed notes for each of the presentations Saturday marked the start of the conference: Arun Thomas provided background and then a rundown of what is happening with the RISC-V architecture. Notes George Neville-Neil talked about using DTrace in distributed systems as an in-depth auditing system (who did what to whom and when). Notes Baptiste Daroussin presented Poudrière image, an extension of everyone’s favourite package building system, to build custom images of FreeBSD. There was discussion of making this generate ZFS based images as well, making it mesh very well with my talk the next day. Notes Brooks Davis presented his work on an API design for a replacement for mmap. It started with a history of address space management in the BSD family of operating systems going all the way back to the beginning. This overview of the feature and how it evolved filled in many gaps for me, and showed why the newer work would be beneficial. The motivation for the work includes further extensions to support the CHERI hardware platform. Notes Johannes M Dieterich gave an interesting presentation about using FreeBSD and GPU acceleration for high performance computing. One of the slides showed that amd64 has taken almost the entire market for the top 500 super computers, and that linux dominates the list, with only a few remaining non-linux systems. Sadly, at the supercomputing conference the next week, it was announced that linux has achieved 100% saturation of the top 500 super computers list. Johannes detailed the available tools, what ports are missing, what changes should be made to the base system (mostly OpenMP), and generally what FreeBSD needs to do to become a player in the supercomputer OS market. Johannes’ perspective is interesting, as he is a computational chemist, not a computer scientist. Those interested in improving the numerical libraries and GPU acceleration frameworks on FreeBSD should join the ports team. Notes The final talk of the day was Peter Grehan, who spoke about how graphics support in bhyve came to be. He provided a history of how the feature evolved, and where it stands today. Notes Afterwards, we traveled as a group to a large restaurant for dinner. There was even Mongolian Vodka, provided by Ganbold Tsagaankhuu of the FreeBSD project. Sunday: The first talk of the day Sunday was mine. I presented “ZFS: Advanced Integration”, mostly talking about how boot environments work, and the new libbe and be(1) tools that my GSoC student Kyle Kneitinger created to manage them. I talked about how they can be used for laptop and developer systems, but also how boot environments can be used to replace nanobsd for appliances (as already done in FreeNAS and pfSense). I also presented about zfsbootcfg (zfs nextboot), and some future extensions to it to make it even more useful in appliance type workloads. I also provided a rundown of new developments out of the ZFS developer summit, two weeks previous. Notes Theo de Raadt presented “Mitigations and other real Security Features”, and made his case for changing to a ‘fail closed’ mode of interoperability. Computer’s cannot actually self heal, so lets stop pretending that they can. Notes Ruslan Bukin talked about doing the port of FreeBSD for RISC-V and writing the Device Drivers. Ruslan walked through the process step by step, leading members of the audience to suggest he turn it into a developer’s handbook article, explaining how to do the initial bringup on new hardware. Ruslan also showed off a FreeB

Nov 22, 20171h 56m

220: Opening ZFS in 2017

We have a first PS4 kernel exploit, the long awaited OpenZFS devsummit report by Allan, DragonflyBSD 5.0 is out, we show you vmadm to manage jails, and parallel processing with Unix tools. This episode was brought to you by Headlines The First PS4 Kernel Exploit: Adieu The First PS4 Kernel Exploit: Adieu Plenty of time has passed since we first demonstrated Linux running on the PS4. Now we will step back a bit and explain how we managed to jump from the browser process into the kernel such that ps4-kexec et al. are usable. Over time, ps4 firmware revisions have progressively added many mitigations and in general tried to lock down the system. This post will mainly touch on vulnerabilities and issues which are not present on the latest releases, but should still be useful for people wanting to investigate ps4 security. Vulnerability Discovery As previously explained, we were able to get a dump of the ps4 firmware 1.01 kernel via a PCIe man-in-the-middle attack. Like all FreeBSD kernels, this image included “export symbols” - symbols which are required to perform kernel and module initialization processes. However, the ps4 1.01 kernel also included full ELF symbols (obviously an oversight as they have been removed in later firmware versions). This oversight was beneficial to the reverse engineering process, although of course not a true prerequisite. Indeed, we began exploring the kernel by examining built-in metadata in the form of the syscall handler table - focusing on the ps4-specific entries. Each process object in the kernel contains its own “idt” (ID Table) object. As can be inferred from the snippet above, the hash table essentially just stores pointers to opaque data blobs, along with a given kind and name. Entries may be accessed (and thus “locked”) with either read or write intent. Note that IDT_TYPE is not a bitfield consisting of only unique powers of 2. This means that if we can control the kind of an id_entry, we may be able to cause a type confusion to occur (it is assumed that we may control name). Exploitation To an exploiter without ps4 background, it might seem that the easiest way to exploit this bug would be to take advantage of the write off the end of the malloc’d namedobj_usr_t object. However, this turns out to be impossible (as far as I know) because of a side effect of the ps4 page size being changed to 0x4000 bytes (from the normal of 0x1000). It appears that in order to change the page size globally, the ps4 kernel developers opted to directly change the related macros. One of the many changes resulting from this is that the smallest actual amount of memory which malloc may give back to a caller becomes 0x40 bytes. While this also results in tons of memory being completely wasted, it does serve to nullify certain exploitation techniques (likely completely by accident…). Adieu The namedobj exploit was present and exploitable (albeit using a slightly different method than described here) until it was fixed in firmware version 4.06. This vulnerability was also found and exploited by (at least) Chaitin Tech, so props to them! Taking a quick look at the 4.07 kernel, we can see a straightforward fix (4.06 is assumed to be identical - only had 4.07 on hand while writing this post): int sys_namedobj_create(struct thread *td, void *args) { // ... rv = EINVAL; kind = *((_DWORD *)args + 4) if ( !(kind & 0x4000) && *(_QWORD *)args ) { // ... (unchanged) } return rv; } And so we say goodbye to a nice exploit. I hope you enjoyed this blast from the past :) Keep hacking! OpenZFS Developer Summit 2017 Recap The 5th annual OpenZFS Developer Summit was held in San Francisco on October 24-25. Hosted by Delphix at the Children’s Creativity Museum in San Francisco, over a hundred OpenZFS contributors from a wide variety of companies attended and collaborated during the conference and developer summit. iXsystems was a Gold sponsor and several iXsystems employees attended the conference, including the entire Technical Documentation Team, the Director of Engineering, the Senior Analyst, a Tier 3 Support Engineer, and a Tier 2 QA Engineer. Day 1 of the conference had 9 highly detailed, informative, and interactive technical presentations from companies which use or contribute to OpenZFS. The presentations highlighted improvements to OpenZFS developed “in-house” at each of these companies, with most improvements looking to be made available to the entire OpenZFS community in the near to long term. There’s a lot of exciting stuff happening in the OpenZFS community and this post provides an overview of the presented features and proof-of-concepts. The keynote was delivered by Mark Maybee who spoke about the past, present, and future of ZFS at Oracle. An original ZFS developer, he outlined the history of closed-source ZFS development after Oracle’s acquisition of Sun. ZFS has a fascinating history, as the project has evolved over the last decade in both open and closed source forms, independent o

Nov 15, 20171h 54m