Search Results: "will"

24 September 2017

Iain R. Learmonth: Free Software Efforts (2017W38)

Here s my weekly report for week 38 of 2017. This week has not been a great week as I saw my primary development machine die in a spectacular reboot loop. Thanks to the wonderful community around Debian and free software (that if you re reading this, you re probably part of), I should be back up to speed soon. A replacement workstation is currently moving towards me and I ve received a number of smaller donations that will go towards video converters and upgrades to get me back to full productivity.

Debian I ve prepared and tested backports for 3 packages in the tasktools packaging team: tasksh, bugwarrior and powerline-taskwarrior. Unfortunately I am not currently in the backports ACLs and so I can t upload these but I m hoping this to be resolved soon. Once these are uploaded, the latest upstream release for all packages in the tasktools team will be available either in the stable suite or in the stable backports suite. In preparation for the shutdown of Alioth mailing lists, I ve set up a new mailing list for the tasktools team and have already updated the maintainer fields for all the team s packages in git. I ve subscribed the old mailing list s user to the new mailing list in DDPO so there will still be a comprehensive view there during the migration. I am currently in the process of reaching out to the admins of git.tasktools.org with a view to moving our git repositories there. I ve also continued to review the scapy package and have closed a couple more bugs that were already fixed in the latest upstream release but had been missed in the changelog. Bugs closed (fixed/wontfix): #774962, #850570

Tor Project I ve deployed a small fix to an update from last week where the platform field on Atlas had been pulled across to the left column. It has now been returned to the right hand column and is not pushed down the page by long family lists. I ve been thinking about the merge of Compass functionality into a future Atlas and this is being tracked in #23517. Tor Project has approved expenses (flights and hotel) for me to attend an in-person meeting of the Metrics Team. This meeting will occur in Berlin on the 28th September and I will write up a report detailing outcomes relevant to my work after the meeting. I have spent some time this week preparing for this meeting. Bugs closed (fixed/wontfix): #22146, #22297, #23511

Sustainability I believe it is important to be clear not only about the work I have already completed but also about the sustainability of this work into the future. I plan to include a short report on the current sustainability of my work in each weekly report. The loss of my primary development machine was a setback, however, I have been donated a new workstation which should hopefully arrive soon. The hard drives in my NAS can now also be replaced as I have budget available for this now. I do not see any hardware failures being imminent at this time, however should they occur I would not have budget to replace hardware, I only have funds to replace the hardware that has already failed.

Iain R. Learmonth: Free Software Efforts (2017W38)

Here s my weekly report for week 38 of 2017. This week has not been a great week as I saw my primary development machine die in a spectacular reboot loop. Thanks to the wonderful community around Debian and free software (that if you re reading this, you re probably part of), I should be back up to speed soon. A replacement workstation is currently moving towards me and I ve received a number of smaller donations that will go towards video converters and upgrades to get me back to full productivity.

Petter Reinholdtsen: Easier recipe to observe the cell phones around you

A little more than a month ago I wrote how to observe the SIM card ID (aka IMSI number) of mobile phones talking to nearby mobile phone base stations using Debian GNU/Linux and a cheap USB software defined radio, and thus being able to pinpoint the location of people and equipment (like cars and trains) with an accuracy of a few kilometer. Since then we have worked to make the procedure even simpler, and it is now possible to do this without any manual frequency tuning and without building your own packages. The gr-gsm package is now included in Debian testing and unstable, and the IMSI-catcher code no longer require root access to fetch and decode the GSM data collected using gr-gsm. Here is an updated recipe, using packages built by Debian and a git clone of two python scripts:
  1. Start with a Debian machine running the Buster version (aka testing).
  2. Run 'apt install gr-gsm python-numpy python-scipy python-scapy' as root to install required packages.
  3. Fetch the code decoding GSM packages using 'git clone github.com/Oros42/IMSI-catcher.git'.
  4. Insert USB software defined radio supported by GNU Radio.
  5. Enter the IMSI-catcher directory and run 'python scan-and-livemon' to locate the frequency of nearby base stations and start listening for GSM packages on one of them.
  6. Enter the IMSI-catcher directory and run 'python simple_IMSI-catcher.py' to display the collected information.
Note, due to a bug somewhere the scan-and-livemon program (actually its underlying program grgsm_scanner) do not work with the HackRF radio. It does work with RTL 8232 and other similar USB radio receivers you can get very cheaply (for example from ebay), so for now the solution is to scan using the RTL radio and only use HackRF for fetching GSM data. As far as I can tell, a cell phone only show up on one of the frequencies at the time, so if you are going to track and count every cell phone around you, you need to listen to all the frequencies used. To listen to several frequencies, use the --numrecv argument to scan-and-livemon to use several receivers. Further, I am not sure if phones using 3G or 4G will show as talking GSM to base stations, so this approach might not see all phones around you. I typically see 0-400 IMSI numbers an hour when looking around where I live. I've tried to run the scanner on a Raspberry Pi 2 and 3 running Debian Buster, but the grgsm_livemon_headless process seem to be too CPU intensive to keep up. When GNU Radio print 'O' to stdout, I am told there it is caused by a buffer overflow between the radio and GNU Radio, caused by the program being unable to read the GSM data fast enough. If you see a stream of 'O's from the terminal where you started scan-and-livemon, you need a give the process more CPU power. Perhaps someone are able to optimize the code to a point where it become possible to set up RPi3 based GSM sniffers? I tried using Raspbian instead of Debian, but there seem to be something wrong with GNU Radio on raspbian, causing glibc to abort().

23 September 2017

Russell Coker: Converting Mbox to Maildir

MBox is the original and ancient format for storing mail on Unix systems, it consists of a single file per user under /var/spool/mail that has messages concatenated. Obviously performance is very poor when deleting messages from a large mail store as the entire file has to be rewritten. Maildir was invented for Qmail by Dan Bernstein and has a single message per file giving fast deletes among other performance benefits. An ongoing issue over the last 20 years has been converting Mbox systems to Maildir. The various ways of getting IMAP to work with Mbox only made this more complex. The Dovecot Wiki has a good page about converting Mbox to Maildir [1]. If you want to keep the same message UIDs and the same path separation characters then it will be a complex task. But if you just want to copy a small number of Mbox accounts to an existing server then it s a bit simpler. Dovecot has a mb2md.pl script to convert folders [2].
cd /var/spool/mail
mkdir -p /mailstore/example.com
for U in * ; do
  ~/mb2md.pl -s $(pwd)/$U -d /mailstore/example.com/$U
done
To convert the inboxes shell code like the above is needed. If the users don t have IMAP folders (EG they are just POP users or use local Unix MUAs) then that s all you need to do.
cd /home
for DIR in */mail ; do
  U=$(echo $DIR  cut -f1 -d/)
  cd /home/$DIR
  for FOLDER in * ; do
    ~/mb2md.pl -s $(pwd)/$FOLDER -d /mailstore/example.com/$U/.$FOLDER
  done
  cp .subscriptions /mailstore/example.com/$U/ subscriptions
done
Some shell code like the above will convert the IMAP folders to Maildir format. The end result is that the users will have to download all the mail again as their MUA will think that every message had been deleted and replaced. But as all servers with significant amounts of mail or important mail were probably converted to Maildir a decade ago this shouldn t be a problem.

22 September 2017

Enrico Zini: Systemd on the command line

These are the notes of a training course on systemd I gave as part of my work with Truelite. Exploring the state of a system Start and stop services Similar to the System V service command, systemctl provides commands to start/stop/restart/reload units or services: Changing global system state systemctl has halt, poweroff, reboot, suspend, hibernate, and hybrid-sleep commands to tell systemd to reboot, power off, suspend and so on. kexec and switch-root also work. The rescue and emergency commands switch the system to rescue and emergency mode (see man systemd.special. systemctl default switches to the default mode, which also happens when exiting the rescue or emergency shell. Run services at boot systemd does not implement runlevels, and services start at boot based on their dependencies. To start a service at boot, you add to its .service file a WantedBy= dependency on a well-known .target unit. At boot, systemd brings up the whole chain of dependency started from a default unit, and that will eventually activate also your service. See systemctl get-default for what unit is currently the default in your system. You can change it via the systemd.unit= kernel command line, so you can configure multiple entries in the boot loader that boot the system running different services. For example systemd.unit=rescue.target for a rescue mode, systemd.unit=multi-user.target for a non-graphical mode, or add your own .target file to implement new system modes. See systemctl list-units -t target --all for a list of all currently available targets in your system. Notes: systemctl start activates a unit right now, but does not automatically enable it at boot systemctl enable enables a unit at boot, but does not automatically start it right now * a disabled unit can still be activated if another unit depends on it To disable a unit so that it will never get started even if another unit depends on it, use systemctl mask unitname. Use systemctl unmask unitname to undo the masking. Reloading / restarting systemd systemctl daemon-reload tells systemd to reload its configuration. systemctl daemon-reexec tells systemd to restart iself.

Iain R. Learmonth: It Died: An Update

Update: I ve had an offer of a used workstation that I m following up. I would still appreciate any donations to go towards costs for cables/converters/upgrades needed with the new system but the hard part should hopefully be out the way now. (: Thanks for all the responses I ve received about the death of my desktop PC. As I updated in my previous post, I find it unlikely that I will have to orphan any of my packages as I believe that I should be able to get a new workstation soon.

20 September 2017

Steve Kemp: Retiring the Debian-Administration.org site

So previously I've documented the setup of the Debian-Administration website, and now I'm going to retire it I'm planning how that will work. There are currently 12 servers powering the site: I've made a bunch of commits recently to drop the event-sending, since no more dynamic actions will be possible. So events can be retired immediately. redis will go when I turn off logins, as there will be no need for sessions/cookies. beta is only used for development, so I'll kill that too. Once logins are gone, and anonymous content is disabled there will be no need to send out emails, so mailer can be shutdown. That leaves a bunch of hosts left: All in all I think we'll just have five hosts left: I think that's sane for the moment. I'm still pondering whether to export the code to static HTML, there's a lot of appeal as the load would drop a log, but equally I have a hell of a lot of mod_rewrite redirections in place, and reworking all of them would be a pain. Suspect this is something that will be done in the future, maybe next year.

19 September 2017

Gunnar Wolf: Call to Mexicans: Open up your wifi #sismo

Hi friends, ~3hr ago, we just had a big earthquake, quite close to Mexico City. Fortunately, we are fine, as are (at least) most of our friends and family. Hopefully, all of them. But there are many (as in, tens) damaged or destroyed buildings; there have been over 50 deceased people, and numbers will surely rise until a good understanding of the event's strength are evaluated. Mainly in these early hours after the quake, many people need to get in touch with their families and friends. There is a little help we can all provide: Provide communication. Open up your wireless network. Set it up unencrypted, for anybody to use. Refrain from over-sharing graphical content Your social network groups don't need to see every video and every photo of the shaking moments and of broken buildings. Download of all those images takes up valuable time-space for the saturated cellular networks. This advice might be slow to flow... The important moment to act is two or three hours ago, even now... But we are likely to have replicas; we are likely to have panic moments again. Do a little bit to help others in need!

18 September 2017

Carl Chenet: The Github threat

Many voices arise now and then against risks linked to the Github use by Free Software projects. Yet the infatuation for the collaborative forge of the Octocat Californian start-ups doesn t seem to fade away.

These recent years, Github and its services take an important role in software engineering as they are seen as easy to use, efficient for a daily workload with interesting functions in enterprise collaborative workflow or amid a Free Software project. What are the arguments against using its services and are they valid? We will list them first, then we ll examine their validity.

1. Critical points

1.1 Centralization

The Github application belongs to a single entity, Github Inc, a US company which manage it alone. So, a unique company under US legislation manages the access to most of Free Software application code sources, which may be a problem with groups using it when a code source is no longer available, for political or technical reason.

The Octocat, the Github mascot

This centralization leads to another trouble: as it obtained critical mass, it becomes more and more difficult not having a Github account. People who don t use Github, by choice or not, are becoming a silent minority. It is now fashionable to use Github, and not doing so is seen as out of date . The same phenomenon is a classic, and even the norm, for proprietary social networks (Facebook, Twitter, Instagram).

1.2 A Proprietary Software

When you interact with Github, you are using a proprietary software, with no access to its source code and which may not work the way you think it is. It is a problem at different levels. First, ideologically, but foremost in practice. In the Github case, we send them code we can control outside of their interface. We also send them personal information (profile, Github interactions). And mostly, Github forces any project which goes through the US platform to use a crucial proprietary tools: its bug tracking system.

Windows, the epitome of proprietary software, even if others took the same path

1.3 The Uniformization

Working with Github interface seems easy and intuitive to most. Lots of companies now use it as a source repository, and many developers leaving a company find the same Github working environment in the next one. This pervasive presence of Github in free software development environment is a part of the uniformization of said developers working space.

Uniforms always bring Army in my mind, here the Clone army

2 Critical points cross-examination

2.1 Regarding the centralization

2.1.1 Service availability rate

As said above, nowadays, Github is the main repository of Free Software source code. As such it is a favorite target for cyberattacks. DDOS hit it in March and August 2015. On December 15, 2015, an outage led to the inaccessibility of 5% of the repositories. The same occurred on November 15. And these are only the incident reported by Github itself. One can imagine that the mean outage rate of the platform is underestimated.

2.1.2 Chain reaction could block Free Software development

Today many dependency maintenance tools, as npm for javascript, Bundler for Ruby or even pip for Python can access an application source code directly from Github. Free Software projects getting more and more linked and codependents, if one component is down, all the developing process stop.

One of the best examples is the npmgate. Any company could legally demand that Github take down some source code from its repository, which could create a chain reaction and blocking the development of many Free Software projects, as suffered the Node.js community from the decisions of Npm, Inc, the company managing npm.

2.2 A historical precedent: SourceForge

Github didn t appear out of the blue. In his time, its predecessor, SourceForge, was also extremely popular.

Heavily centralized, based on strong interaction with the community, SourceForge is now seen as an aging SAAS (Software As A Service) and sees most of its customers fleeing to Github. Which creates lots of hurdles for those who stayed. The Gimp project suffered from spams and terrible advertising, which led to the departure of the VLC project, then from installers corrupted with adwares instead of the official Gimp installer for Windows. And finally, the Project Gimp s SourceForge account was hacked by SourceForge team itself!

These are very recent examples of what can do a commercial entity when it is under its stakeholders pressure. It is vital to really understand what it means to trust them with data and exchange centralization, where it could have tremendous repercussion on the day-to-day life and the habits of the Free Software and open source community.

2.3. Regarding proprietary software

2.3.1 One community, several opinions on proprietary software

Mostly based on ideology, this point deals with the definition every member of the community gives to Free Software and open source. Mostly about one thing: is it viral or not? Or GPL vs MIT/BSD.

Those on the side of the viral Free Software will have trouble to use a proprietary software as this last one shouldn t even exist. It must be assimilated, to quote Star Trek, as it is a connected black box, endangering privacy, corrupting for profit our uses and restrain our freedom to use as we re pleased what we own, etc.

Those on the side of complete freedom have no qualms using proprietary software as their very existence is a consequence of freedom without restriction. They even agree that code they developed may be a part of proprietary software, which is quite a common occurrence. This part of the Free Software community has no qualm using Github, which is well within their ideology parameters. Just take a look at the Janson amphitheater during Fosdem and check how many Apple laptops running on macOS are around.

FreeBSD, the main BSD project under the BSD license

2.3.2 Data loss and data restrictions linked to proprietary software use

Even without ideological consideration, and just focusing on Github infrastructure, the bug tracking system is a major problem by itself.

Bug report builds the memory of Free Software projects. It is the entrance point for new contributors, the place to find bug reporting, requests for new functions, etc. The project history can t be limited only to the code. It s very common to find bug reports when you copy and paste an error message in a search engine. Not their historical importance is precious for the project itself, but also for its present and future users.

Github gives the ability to extract bug reports through its API. What would happen if Github is down or if the platform doesn t support this feature anymore? In my opinion, not that many projects ever thought of this outcome. How could they move all the data generated by Github into a new bug tracking system? One old example now is Astrid, a TODO list bought by Yahoo a few years ago. Very popular, it grew fast until it was closed overnight, with only a few weeks for its users to extract their data. It was only a to-do list. The same situation with Github would be tremendously difficult to manage for several projects if they even have the ability to deal with it. Code would still be available and could still live somewhere else, but the project memory would be lost. A project like Debian has today more than 800,000 bug reports, which are a data treasure trove about problems solved, function requests and where the development stand on each. The developers of the Cpython project have anticipated the problem and decided not to use Github bug tracking systems.

Issues, the Github proprietary bug tracking system

Another thing we could lose if Github suddenly disappear: all the work currently done regarding the push requests (aka PRs). This Github function gives the ability to clone one project s Github repository, to modify it to fit your needs, then to offer your own modification to the original repository. The original repository s owner will then review said modification, and if he or she agrees with them will fuse them into the original repository. As such, it s one of the main advantages of Github, since it can be done easily through its graphic interface.

However reviewing all the PRs may be quite long, and most of the successful projects have several ongoing PRs. And this PRs and/or the proprietary bug tracking system are commonly used as a platform for comment and discussion between developers.

Code itself is not lost if Github is down (except one specific situation as seen below), but the peer review works materialized in the PRs and the bug tracking system is lost. Let s remember than the PR mechanism let you clone and modify projects and then generate PRs directly from its proprietary web interface without downloading a single code line on your computer. In this particular case, if Github is down, all the code and the work in progress is lost. Some also use Github as a bookmark place. They follow their favorite projects activity through the Watch function. This technological watch style of data collection would also be lost if Github is down.

Debian, one of the main Free Software projects with at least a thousand official contributors

2.4 Uniformization

The Free Software community is walking a thigh rope between normalization needed for an easier interoperability between its products and an attraction for novelty led by a strong need for differentiation from what is already there.

Github popularized the use of Git, a great tool now used through various sectors far away from its original programming field. Step by step, Git is now so prominent it s almost impossible to even think to another source control manager, even if awesome alternate solutions, unfortunately not as popular, exist as Mercurial.

A new Free Software project is now a Git repository on Github with README.md added as a quick description. All the other solutions are ostracized? How? None or very few potential contributors would notice said projects. It seems very difficult now to encourage potential contributors into learning a new source control manager AND a new forge for every project they want to contribute. Which was a basic requirement a few years ago. It s quite sad because Github, offering an original experience to its users, cut them out of a whole possibility realm. Maybe Github is one of the best web versioning control systems. But being the main one doesn t let room for a new competitor to grow. And it let Github initiate development newcomers into a narrow function set, totally unrelated to the strength of the Git tool itself.

3. Centralization, uniformization, proprietary software What s next? Laziness?

Fight against centralization is a main part of the Free Software ideology as centralization strengthens the power of those who manage it and who through it control those who are managed by it. Uniformization allergies born against main software companies and their wishes to impose a closed commercial software world was for a long time the main fuel for innovation thirst and intelligent alternative development. As we said above, part of the Free Software community was built as a reaction to proprietary software and their threat. The other part, without hoping for their disappearance, still chose a development model opposite to proprietary software, at least in the beginning, as now there s more and more bridges between the two.

The Github effect is a morbid one because of its consequences: at least centralization, uniformization, proprietary software usage as their bug tracking system. But some years ago the Dear Github buzz showed one more side effect, one I ve never thought about: laziness. For those who don t know what it is about, this letter is a complaint from several spokespersons from several Free Software projects which demand to Github team to finally implement, after years of polite asking, new functions. Since when Free Software project facing a roadblock request for clemency and don t build themselves the path they need? When Torvalds was involved in the Bitkeeper problem and the Linux kernel development team couldn t use anymore their revision control software, he developed Git. The mere fact of not being able to use one tool or functions lacking is the main motivation to seek alternative solutions and, as such, of the Free Software movement. Every Free Software community member able to code should have this reflex. You don t like what Github offers? Switch to Gitlab. You don t like it Gitlab? Improve it or make your own solution.

The Gitlab logo

Let s be crystal clear. I ve never said that every Free Software developers blocked should code his or her own alternative. We all have our own priorities, and some of us even like their beauty sleep, including me. But, to see that this open letter to Github has 1340 names attached to it, among them some spokespersons for major Free Software project showed me that need, willpower and strength to code a replacement are here. Maybe said replacement will be born from this letter, it would be the best outcome of this buzz.

In the end, Github usage is just another example of Internet usage massification. As Internet users are bound to go to massively centralized social network as Facebook or Twitter, developers are following the same path with Github. Even if a large fraction of developers realize the threat linked this centralized and proprietary organization, the whole community is following this centralization and uniformization trend. Github service is useful, free or with a reasonable price (depending on the functions you need) easy to use and up most of the time. Why would we try something else? Maybe because others are using us while we are savoring the convenience? The Free Software community seems to be quite sleepy to me.

The lion enjoying the hearth warm

About Me Carl Chenet, Free Software Indie Hacker, founder of the French-speaking Hacker News-like Journal du hacker. Follow me on social networks Translated from French by St phanie Chaptal. Original article written in 2015.

Russ Allbery: Consolidation haul

My parents are less fond than I am of filling every available wall in their house with bookshelves and did a pruning of their books. A lot of them duplicated other things that I had, or didn't sound interesting, but I still ended up with two boxes of books (and now have to decide which of my books to prune, since I'm out of shelf space). Also included is the regular accumulation of new ebook purchases. Mitch Albom Tuesdays with Morrie (nonfiction)
Ilona Andrews Clean Sweep (sff)
Catherine Asaro Charmed Sphere (sff)
Isaac Asimov The Caves of Steel (sff)
Isaac Asimov The Naked Sun (sff)
Marie Brennan Dice Tales (nonfiction)
Captain Eric "Winkle" Brown Wings on My Sleeve (nonfiction)
Brian Christian & Tom Griffiths Algorithms to Live By (nonfiction)
Tom Clancy The Cardinal of the Kremlin (thriller)
Tom Clancy The Hunt for the Red October (thriller)
Tom Clancy Red Storm Rising (thriller)
April Daniels Sovereign (sff)
Tom Flynn Galactic Rapture (sff)
Neil Gaiman American Gods (sff)
Gary J. Hudson They Had to Go Out (nonfiction)
Catherine Ryan Hyde Pay It Forward (mainstream)
John Irving A Prayer for Owen Meany (mainstream)
John Irving The Cider House Rules (mainstream)
John Irving The Hotel New Hampshire (mainstream)
Lawrence M. Krauss Beyond Star Trek (nonfiction)
Lawrence M. Krauss The Physics of Star Trek (nonfiction)
Ursula K. Le Guin Four Ways to Forgiveness (sff collection)
Ursula K. Le Guin Words Are My Matter (nonfiction)
Richard Matheson Somewhere in Time (sff)
Larry Niven Limits (sff collection)
Larry Niven The Long ARM of Gil Hamilton (sff collection)
Larry Niven The Magic Goes Away (sff)
Larry Niven Protector (sff)
Larry Niven World of Ptavvs (sff)
Larry Niven & Jerry Pournelle The Gripping Hand (sff)
Larry Niven & Jerry Pournelle Inferno (sff)
Larry Niven & Jerry Pournelle The Mote in God's Eye (sff)
Flann O'Brien The Best of Myles (nonfiction)
Jerry Pournelle Exiles to Glory (sff)
Jerry Pournelle The Mercenary (sff)
Jerry Pournelle Prince of Mercenaries (sff)
Jerry Pournelle West of Honor (sff)
Jerry Pournelle (ed.) Codominium: Revolt on War World (sff anthology)
Jerry Pournelle & S.M. Stirling Go Tell the Spartans (sff)
J.D. Salinger The Catcher in the Rye (mainstream)
Jessica Amanda Salmonson The Swordswoman (sff)
Stanley Schmidt Aliens and Alien Societies (nonfiction)
Cecilia Tan (ed.) Sextopia (sff anthology)
Lavie Tidhar Central Station (sff)
Catherynne Valente Chicks Dig Gaming (nonfiction)
J.E. Zimmerman Dictionary of Classical Mythology (nonfiction) This is an interesting tour of a lot of stuff I read as a teenager (Asimov, Niven, Clancy, and Pournelle, mostly in combination with Niven but sometimes his solo work). I suspect I will no longer consider many of these books to be very good, and some of them will probably go back into used bookstores after I've re-read them for memory's sake, or when I run low on space again. But all those mass market SF novels were a big part of my teenage years, and a few (like Mote In God's Eye) I definitely want to read again. Also included is a random collection of stuff my parents picked up over the years. I don't know what to expect from a lot of it, which makes it fun to anticipate. Fall vacation is coming up, and with it a large amount of uninterrupted reading time.

17 September 2017

Russ Allbery: Free software log (July and August 2017)

I've wanted to start making one of these posts for a few months but have struggled to find the time. But it seems like a good idea, particularly since I get more done when I write down what I do, so you all get a rather belated one. This covers July and August; hopefully the September one will come closer to the end of September. Debian August was DebConf, which included a ton of Policy work thanks to Sean Whitton's energy and encouragement. During DebConf, we incorporated work from Hideki Yamane to convert Policy to reStructuredText, which has already made it far easier to maintain. (Thanks also to David Bremner for a lot of proofreading of the result.) We also did a massive bug triage and closed a ton of older bugs on which there had been no forward progress for many years. After DebConf, as expected, we flushed out various bugs in the reStructuredText conversion and build infrastructure. I fixed a variety of build and packaging issues and started doing some more formatting cleanup, including moving some footnotes to make the resulting document more readable. During July and August, partly at DebConf and partly not, I also merged wording fixes for seven bugs and proposed wording (not yet finished) for three more, as well as participated in various Policy discussions. Policy was nearly all of my Debian work over these two months, but I did upload a new version of the webauth package to build with OpenSSL 1.1 and drop transitional packages. Kerberos I still haven't decided my long-term strategy with the Kerberos packages I maintain. My personal use of Kerberos is now fairly marginal, but I still care a lot about the software and can't convince myself to give it up. This month, I started dusting off pam-krb5 in preparation for a new release. There's been an open issue for a while around defer_pwchange support in Heimdal, and I spent some time on that and tracked it down to an upstream bug in Heimdal as well as a few issues in pam-krb5. The pam-krb5 issues are now fixed in Git, but I haven't gotten any response upstream from the Heimdal bug report. I also dusted off three old Heimdal patches and submitted them as upstream merge requests and reported some more deficiencies I found in FAST support. On the pam-krb5 front, I updated the test suite for the current version of Heimdal (which changed some of the prompting) and updated the portability support code, but haven't yet pulled the trigger on a new release. Other Software I merged a couple of pull requests in podlators, one to fix various typos (thanks, Jakub Wilk) and one to change the formatting of man page references and function names to match the current Linux manual page standard (thanks, Guillem Jover). I also documented a bad interaction with line-buffered output in the Term::ANSIColor man page. Neither of these have seen a new release yet.

Iain R. Learmonth: Free Software Efforts (2017W37)

I d like to start making weekly reports again on my free software efforts. Part of the reason for these reports is for me to see how much time I m putting into free software. Hopefully I can keep these reports up.

Debian I have updated txtorcon (a Twisted-based asynchronous Tor control protocol implementation used by ooniprobe, magic-wormhole and tahoe-lafs) to its latest upstream version. I ve also added two new binary packages that are built by the txtorcon source package: python3-txtorcon and python-txtorcon-doc for Python 3 support and generated HTML documentation respectively. I have gone through the scapy (Python module for the forging and dissection of network packets) bugs and closed a couple that seem to have been silently fixed by new upstream releases and not been caught in the BTS. I ve uploaded a minor revision to include a patch that fixes the version number reported by scapy. I have prepared and uploaded a new package for measurement-kit (a portable C++11 network measurement library) from the Open Observatory of Network Interference, which at time of writing is still in the NEW queue. I have also updated ooniprobe (probe for the Open Observatory of Network Interference) to its latest upstream version. I have updated the Swedish debconf strings in the xastir (X Amateur Station Tracking and Information Reporting) package, thanks to the translators. I have updated the direwolf (soundcard terminal node controller for APRS) package to its latest upstream version and fixed the creation of the system user to run direwolf with systemd to happen at the time the package is installed. Unfortunately, it has been necessary to drop the PDF documentation from the package as I was unable to contact the upstream author and acquire the Microsoft Word sources for this release. I have reviewed and sponsored the uploads of the new packages comptext (GUI based tool to compare two text streams), comptty (GUI based tool to compare two radio teletype streams) and flnet (amateur radio net control station software) in the hamradio team. Thanks to Ana Custura for preparing those packages, comptext and comptty are now available in unstable. I have updated the Debian Hamradio Blend metapackages to include cubicsdr (a software defined radio receiver). This build also refreshes the list of packages that can now be included as they had not been packaged at the time of the last build. I have produced and uploaded an initial package for python-azure-devtools (development tools for Azure SDK and CLI for Python) and have updated python-azure (the Azure SDK for Python) to a recent git snapshot. Due to some issues with python-vcr it is currently not possible to run the test suite as part of the build process and I m watching the situation. I have also fixed the auto dependency generation for python3-azure, which had previously been broken. Bugs closed (fixed/wontfix): #873036, #871940, #869566, #873083, #867420, #861753, #855385, #855497, #684727, #683711

Tor Project I have been working through tickets for Atlas (a tool for looking up details about Tor relays and bridges) and have merged and deployed a number of fixes. Some highlights include: bandwidth sorting in search results is now semantically correct (not just an alphanumeric sort ignoring units), added when a relay was first seen to the details page along with the host name if a reverse DNS record has been found for the IP address of the relay and added support for the NoEdConsensus flag (although happily no relays had this flag at the time this support was added). The metrics team has been working on merging projects into the metrics team website to give a unified view of information about the Tor network. This week I have been working towards a prototype of a port of Atlas to the metrics website s style and this work has been published in my personal Atlas git repository. If you d like to have a click around, you can do so. A relay operators meetup will be happening in Montreal on the 14th of October. I won t be present, but I have taken this opportunity to ask operators if there s anything that they would like from Atlas that they are not currently getting. Some feedback has already been received and turned into code and trac tickets. I also attended the weekly metrics team meeting in #tor-dev. Bugs closed (fixed/wontfix): #6787, #9814, #21958, #21636, #23296, #23160

Sustainability I believe it is important to be clear not only about the work I have already completed but also about the sustainability of this work into the future. I plan to include a short report on the current sustainability of my work in each weekly report. I continue to be happy to spend my time on this work, however I do find myself in a position where it may not be sustainable when it comes to hardware. My desktop, a Sun Ultra 24, is now 10 years old and I m starting to see random reboots which so far have not been explained. It is incredibly annoying to have this happen during a long build. Further, the hard drives in my NAS which are used for the local backups and for my local Debian mirror are starting to show SMART errors. It is not currently within my budget to replace any of this hardware. Please contact me if you believe you can help.
This week's energy was provided by Club Mate

15 September 2017

Ben Hutchings: Debian LTS work, August 2017

I was assigned 15 hours of work by Freexian's Debian LTS initiative and carried over 1 hour from July. I only worked 10 hours, so I will carry over 6 hours to the next month. I prepared and released an update on the Linux 3.2 longterm stable branch (3.2.92), and started work on the next update. I rebased the Debian linux package on this version, but didn't yet upload it.

14 September 2017

James McCoy: devscripts needs YOU!

Over the past 10 years, I've been a member of a dwindling team of people maintaining the devscripts package in Debian. Nearly two years ago, I sent out a "Request For Help" since it was clear I didn't have adequate time to keep driving the maintenance. In the mean time, Jonas split licensecheck out into its own project and took over development. Osamu has taken on much of the maintenance for uscan, uupdate, and mk-origtargz. Although that has helped spread the maintenance costs, there's still a lot that I haven't had time to address. Since Debian is still fairly early in the development cycle for Buster, I've decided this is as good a time as any for me to officially step down from active involvement in devscripts. I'm willing to keep moderating the mailing list and other related administrivia (which is fairly minimal given the repo is part of collab-maint), but I'll be unsubscribing from all other notifications. I think devscripts serves as a good funnel for useful scripts to get in front of Debian (and its derivatives) developers, but Jonas may also be onto something by pulling scripts out to stand on their own. One of the troubles with "bucket" packages like devscripts is the lack of visibility into when to retire scripts. Breaking scripts out on their own, and possibly creating multiple binary packages, certainly helps with that. Maybe uscan and friends would be a good next candidate. At the end of the day, I've certainly enjoyed being able to play my role in helping simplify the life of all the people contributing to Debian. I may come back to it some day, but for now it's time to let someone else pick up the reins. If you're interested in helping out, you can join #devscripts on OFTC and/or send a mail to <devscripts-devel@lists.alioth.debian.org>.

13 September 2017

Shirish Agarwal: Android, Android marketplace and gaming addiction.

This would be a longish piece so please bear and play with tea, coffee, beer or anything stronger that you desire while reading below  I had bought an Android phone, a Samsung J5 just before going to debconf 2016. It was more for being in-trend rather than really using it. The one which I shared is the upgraded version (recentish) the one I have is 2 GB for which I had paid around double of what the list price was. The only reason I bought the model is that it had removable battery at the price point I was willing to pay. I did see that Samsung has the same ham-handed issues with audio as previous Nokia devices use to, the speakers and microphone probably the cheapest you can get on the market. Nokia was same too, at least on the lower-end of the market, while Oppo has loud ringtones and loud music, perfect for those who are a bit hard of hearing (as yours truly is). I had been pleasantly surprised by the quality of photos Samsung J5 was churning even though I m less than average shooter, never been really into it so was a sort of wake-up call for where camera sensor technology is advancing. And of course with newer phones the kind of detail it can capture is mesmerizing to say the least, although wide-angle shots still would take some time to get right I guess. If memory serves me right, sometime back Laura Arjona Reina (who handles part of debian-publicity and part of debian-women among other responsibilities) shared a blog post on p.d.o. where she had shared the troubles she had while exporting data from the phone. While she shared that and I lack the time or the energy to try and find it ( the entry is really bookmarkable, at least that specific blog post). What was interesting though that I had gone few years ago to Bangalore, there is an organization which I like and admire CIS great for researchers. Anyways they had done a project getting between 10-20 phones from the market made of Chinese origin (almost all mobiles sold in India, the fabrication of CPU and APU etc. are done in China/Taiwan and then assembled here). Here what is done at the most is assembly which for all political purposes is called manufacturing . All the mobiles kept quite a bit of info. on the device even after you wiped them clean/put some other ROM on them. The CIS site is more than a bit cluttered otherwise would have shared the direct link. I do hope to send an e-mail to CIS and hopefully they will respond with the report and will share that here as and when. It would be interesting to know if after people flash a custom rom if the status quo is the same as it was before. I do suspect it would be the former as flashing ROMs on phones is still a bit of specialized subject at least here in India with even an average phone costing a month or two s salary or more and the idea of bricking the phone scares most people (including yours truly). Anyways, for a long time I was on bed and had the phone. I used 2 games from the android marketplace which both mum and I enjoy and enjoyed. Those are Real jigsaw and Jigsaw puzzle HD . The permissions dialog which Real jigsaw among other games has is horrible and part of me freaks that all such apps. have unrestricted access to my storage area. Ideally, what Android should have done is either partition or give functionality to the user to have private space for their photos and whatever media they have and the rest of the area is like a public park. If anybody has any thoughts on partitioning on Android phone would like to hear that. One game though which really hooked mumma and me is The Island Experiment . It reminded me of my younger days when gaming addiction was not treated as a disease but thankfully now is . I would call myself somewhat of a functional addict as in do my every day things, work etc. but do dream about the game as to what it will show me next. A part of it is the game is web-based (which means it needs constant internet connection) and web access is somewhat pricey, although with Reliance Jio an upcoming data network operator having bundles of money and promising the moon, network issues at least on low-bandwidth game which I and mum are playing hopefully will not have any issues. I haven t used tshark or any such tool to analyze the traffic but I guess it probably just sends short messages of number of clicks in a time period and things like that, all the rest (I guess) is happening on the mobile itself. I know at sometime I probably will try to put a custom rom on it but which one is the question as there are so many and also which is most compatible with my device. It seems I would have to do lot of homework before I can make any choices. Couple of months back, a friend of mine Akshat who has been using Android for few years enabled Developer Options which I didn t know about till he shared that info. with me. I do hope people do check Akshat s repo. as he has made/has quite a few useful scripts, especially if you are into digital photography. I have shared with him gimp scripting few days back so along with imagemagick you might see him doing some rough scripts in it. Of course, if people use it and give feedback he might clean the scripts a bit so it gives useful error messages and gives statement like gimp is not installed on your system, please install it or ask for specific version but as it works in free software it is somewhat directly proportional to the number of users, bugs and users behind it. A good example of what I mean is youtube-dl . I filed 873853 where I shared the upstream ticket. Apparently YouTube again changed few days back and while upstream has fixed it, the youtube-dl maintainer probably needs to find time and get the new version up. Apparently the issues lies in [$] dpkg -L youtube-dl grep youtube.py
/usr/lib/python3/dist-packages/youtube_dl/extractor/youtube.py
Hopefully somebody does the needful. Btw, I find f-droid extremely useful and especially osmand but sadly both of them are not shared or talked about by people  The reason I shared about Developer Options in Android is that few days back I noticed that the phone wonks off and has unpredictable behaviour such as not letting me browse the web, do additions or deletions using the google play store and alike . Things came to a head when few days back I saw a fibre-optic splicing operation being carried by some workers near my home by the state operator which elated me and wanted to shoot the video for it but the battery died/there was no power even though I hadn t used it much. I have deliberately shared the hindi version which tells how that knowledge is now coming to the masses. I had seen fibre-optic splicing more than a decade and a half back at some net conference where it was going to be in your neighbourhood soonish, hopefully it will happen soon  I had my suspicions for quite sometime all the issues with the phone were not due to proper charging. During course of my investigation, found out that in Developer Options there is an option called USB Configuration and changing that from the default MTP (Media Transfer Protocol) (which is basically used to put or take movies, music or any file from the phone to the computer or vice-versa improved much better behaviour on my android phone. But this caused an unexpected side-effect, I got pretty aggressive polling of the phone by the computer even after saying I do not want to share the phone details with the computer. This I filed as 874216 . The phone and I am guessing most Samsung phones today come with an adaptor with a USB male socket which goes in to the phone s usb port. There is the classical port for electricity but like most people heavily rely on usb charging even for deep fully powered down phone for full charging. One interesting project which I saw which came in Debian some days back is dummydroid. I did file a bug about it . I do hope that either the maintainer gives some more documentation. I am sure many people might use and add to the resource if the documentation was/is there. I did take a look at the package and the profile seems to be like an xml pair kind of database. Having more profiles shouldn t be hard if we knew what info. needs to be added and how do we find that info. Lastly, I am slowly transferring all the above knowledge to my mum as well, although in small doses. She, just like me has and had problems coming from resistive touchscreen to capacitive touchscreen. You can call me wrong but resistive touchscreen seemed to be superior and not as error-prone or liable to commit mistakes as is possible in capacitive touchscreens. There may be a setting to higher/lower the threshold for touching which I have not been able to find as of yet. Hope somebody finds something useful in there. I do hope that Debian does become a replacement to be used on such mobiles but then they would have to duplicate/also have some sort of mainstream content with editors to help people find stuff, something that Debian is not so good at currently. Also I m not sure Synaptic is good fit as a mobile store.
Filed under: Miscellenous Tagged: #Android, #capacitive touchscreen, #custom ROMs, #digital photography, #dummydroid, #f-droid, #fabrication, #flashing, #game addiction, #Google Play Store, #Mainstreaming Debian, #mobile connectivity, #Oppo, #osmand, #planet-debian, #resistive touchscreen, #Samsung Galaxy J5, #scripting, #USB charging, #USB configuration, #youtube-dl, gaming

Vincent Bernat: Route-based IPsec VPN on Linux with strongSwan

A common way to establish an IPsec tunnel on Linux is to use an IKE daemon, like the one from the strongSwan project, with a minimal configuration1:
conn V2-1
  left        = 2001:db8:1::1
  leftsubnet  = 2001:db8:a1::/64
  right       = 2001:db8:2::1
  rightsubnet = 2001:db8:a2::/64
  authby      = psk
  auto        = route
The same configuration can be used on both sides. Each side will figure out if it is left or right . The IPsec site-to-site tunnel endpoints are 2001:db8: 1::1 and 2001:db8: 2::1. The protected subnets are 2001:db8: a1::/64 and 2001:db8: a2::/64. As a result, strongSwan configures the following policies in the kernel:
$ ip xfrm policy
src 2001:db8:a1::/64 dst 2001:db8:a2::/64
        dir out priority 399999 ptype main
        tmpl src 2001:db8:1::1 dst 2001:db8:2::1
                proto esp reqid 4 mode tunnel
src 2001:db8:a2::/64 dst 2001:db8:a1::/64
        dir fwd priority 399999 ptype main
        tmpl src 2001:db8:2::1 dst 2001:db8:1::1
                proto esp reqid 4 mode tunnel
src 2001:db8:a2::/64 dst 2001:db8:a1::/64
        dir in priority 399999 ptype main
        tmpl src 2001:db8:2::1 dst 2001:db8:1::1
                proto esp reqid 4 mode tunnel
[ ]
This kind of IPsec tunnel is a policy-based VPN: encapsulation and decapsulation are governed by these policies. Each of them contains the following elements: When a matching policy is found, the kernel will look for a corresponding security association (using reqid and the endpoint source and destination addresses):
$ ip xfrm state
src 2001:db8:1::1 dst 2001:db8:2::1
        proto esp spi 0xc1890b6e reqid 4 mode tunnel
        replay-window 0 flag af-unspec
        auth-trunc hmac(sha256) 0x5b68[ ]8ba2904 128
        enc cbc(aes) 0x8e0e377ad8fd91e8553648340ff0fa06
        anti-replay context: seq 0x0, oseq 0x0, bitmap 0x00000000
[ ]
If no security association is found, the packet is put on hold and the IKE daemon is asked to negotiate an appropriate one. Otherwise, the packet is encapsulated. The receiving end identifies the appropriate security association using the SPI in the header. Two security associations are needed to establish a bidirectionnal tunnel:
$ tcpdump -pni eth0 -c2 -s0 esp
13:07:30.871150 IP6 2001:db8:1::1 > 2001:db8:2::1: ESP(spi=0xc1890b6e,seq=0x222)
13:07:30.872297 IP6 2001:db8:2::1 > 2001:db8:1::1: ESP(spi=0xcf2426b6,seq=0x204)
All IPsec implementations are compatible with policy-based VPNs. However, some configurations are difficult to implement. For example, consider the following proposition for redundant site-to-site VPNs: Redundant VPNs between 3 sites A possible configuration between V1-1 and V2-1 could be:
conn V1-1-to-V2-1
  left        = 2001:db8:1::1
  leftsubnet  = 2001:db8:a1::/64,2001:db8:a6::cc:1/128,2001:db8:a6::cc:5/128
  right       = 2001:db8:2::1
  rightsubnet = 2001:db8:a2::/64,2001:db8:a6::/64,2001:db8:a8::/64
  authby      = psk
  keyexchange = ikev2
  auto        = route
Each time a subnet is modified on one site, the configurations need to be updated on all sites. Moreover, overlapping subnets (2001:db8: a6::/64 on one side and 2001:db8: a6::cc:1/128 at the other) can also be problematic. The alternative is to use route-based VPNs: any packet traversing a pseudo-interface will be encapsulated using a security policy bound to the interface. This brings two features:
  1. Routing daemons can be used to distribute routes to be protected by the VPN. This decreases the administrative burden when many subnets are present on each side.
  2. Encapsulation and decapsulation can be executed in a different routing instance or namespace. This enables a clean separation between a private routing instance (where VPN users are) and a public routing instance (where VPN endpoints are).

Route-based VPN on Juniper Before looking at how to achieve that on Linux, let s have a look at the way it works with a JunOS-based platform (like a Juniper vSRX). This platform as long-standing history of supporting route-based VPNs (a feature already present in the Netscreen ISG platform). Let s assume we want to configure the IPsec VPN from V3-2 to V1-1. First, we need to configure the tunnel interface and bind it to the private routing instance containing only internal routes (with IPv4, they would have been RFC 1918 routes):
interfaces  
    st0  
        unit 1  
            family inet6  
                address 2001:db8:ff::7/127;
             
         
     
 
routing-instances  
    private  
        instance-type virtual-router;
        interface st0.1;
     
 
The second step is to configure the VPN:
security  
    /* Phase 1 configuration */
    ike  
        proposal IKE-P1  
            authentication-method pre-shared-keys;
            dh-group group20;
            encryption-algorithm aes-256-gcm;
         
        policy IKE-V1-1  
            mode main;
            proposals IKE-P1;
            pre-shared-key ascii-text "d8bdRxaY22oH1j89Z2nATeYyrXfP9ga6xC5mi0RG1uc";
         
        gateway GW-V1-1  
            ike-policy IKE-V1-1;
            address 2001:db8:1::1;
            external-interface lo0.1;
            general-ikeid;
            version v2-only;
         
     
    /* Phase 2 configuration */
    ipsec  
        proposal ESP-P2  
            protocol esp;
            encryption-algorithm aes-256-gcm;
         
        policy IPSEC-V1-1  
            perfect-forward-secrecy keys group20;
            proposals ESP-P2;
         
        vpn VPN-V1-1  
            bind-interface st0.1;
            df-bit copy;
            ike  
                gateway GW-V1-1;
                ipsec-policy IPSEC-V1-1;
             
            establish-tunnels on-traffic;
         
     
 
We get a route-based VPN because we bind the st0.1 interface to the VPN-V1-1 VPN. Once the VPN is up, any packet entering st0.1 will be encapsulated and sent to the 2001:db8: 1::1 endpoint. The last step is to configure BGP in the private routing instance to exchange routes with the remote site:
routing-instances  
    private  
        routing-options  
            router-id 1.0.3.2;
            maximum-paths 16;
         
        protocols  
            bgp  
                preference 140;
                log-updown;
                group v4-VPN  
                    type external;
                    local-as 65003;
                    hold-time 6;
                    neighbor 2001:db8:ff::6 peer-as 65001;
                    multipath;
                    export [ NEXT-HOP-SELF OUR-ROUTES NOTHING ];
                 
             
         
     
 
The export filter OUR-ROUTES needs to select the routes to be advertised to the other peers. For example:
policy-options  
    policy-statement OUR-ROUTES  
        term 10  
            from  
                protocol ospf3;
                route-type internal;
             
            then  
                metric 0;
                accept;
             
         
     
 
The configuration needs to be repeated for the other peers. The complete version is available on GitHub. Once the BGP sessions are up, we start learning routes from the other sites. For example, here is the route for 2001:db8: a1::/64:
> show route 2001:db8:a1::/64 protocol bgp table private.inet6.0 best-path
private.inet6.0: 15 destinations, 19 routes (15 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
2001:db8:a1::/64   *[BGP/140] 01:12:32, localpref 100, from 2001:db8:ff::6
                      AS path: 65001 I, validation-state: unverified
                      to 2001:db8:ff::6 via st0.1
                    > to 2001:db8:ff::14 via st0.2
It was learnt both from V1-1 (through st0.1) and V1-2 (through st0.2). The route is part of the private routing instance but encapsulated packets are sent/received in the public routing instance. No route-leaking is needed for this configuration. The VPN cannot be used as a gateway from internal hosts to external hosts (or vice-versa). This could also have been done with JunOS security policies (stateful firewall rules) but doing the separation with routing instances also ensure routes from different domains are not mixed and a simple policy misconfiguration won t lead to a disaster.

Route-based VPN on Linux Starting from Linux 3.15, a similar configuration is possible with the help of a virtual tunnel interface3. First, we create the private namespace:
# ip netns add private
# ip netns exec private sysctl -qw net.ipv6.conf.all.forwarding=1
Any private interface needs to be moved to this namespace (no IP is configured as we can use IPv6 link-local addresses):
# ip link set netns private dev eth1
# ip link set netns private dev eth2
# ip netns exec private ip link set up dev eth1
# ip netns exec private ip link set up dev eth2
Then, we create vti6, a tunnel interface (similar to st0.1 in the JunOS example):
# ip tunnel add vti6 \
   mode vti6 \
   local 2001:db8:1::1 \
   remote 2001:db8:3::2 \
   key 6
# ip link set netns private dev vti6
# ip netns exec private ip addr add 2001:db8:ff::6/127 dev vti6
# ip netns exec private sysctl -qw net.ipv4.conf.vti6.disable_policy=1
# ip netns exec private sysctl -qw net.ipv4.conf.vti6.disable_xfrm=1
# ip netns exec private ip link set vti6 mtu 1500
# ip netns exec private ip link set vti6 up
The tunnel interface is created in the initial namespace and moved to the private one. It will remember its original namespace where it will process encapsulated packets. Any packet entering the interface will temporarily get a firewall mark of 6 that will be used only to match the appropriate IPsec policy4 below. The kernel sets a low MTU on the interface to handle any possible combination of ciphers and protocols. We set it to 1500 and let PMTUD do its work. We can then configure strongSwan5:
conn V3-2
  left        = 2001:db8:1::1
  leftsubnet  = ::/0
  right       = 2001:db8:3::2
  rightsubnet = ::/0
  authby      = psk
  mark        = 6
  auto        = route
  keyexchange = ikev2
  keyingtries = %forever
  ike         = aes256gcm16-prfsha384-ecp384!
  esp         = aes256gcm16-prfsha384-ecp384!
  mobike      = no
The IKE daemon configures the following policies in the kernel:
$ ip xfrm policy
src ::/0 dst ::/0
        dir out priority 399999 ptype main
        mark 0x6/0xffffffff
        tmpl src 2001:db8:1::1 dst 2001:db8:3::2
                proto esp reqid 1 mode tunnel
src ::/0 dst ::/0
        dir fwd priority 399999 ptype main
        mark 0x6/0xffffffff
        tmpl src 2001:db8:3::2 dst 2001:db8:1::1
                proto esp reqid 1 mode tunnel
src ::/0 dst ::/0
        dir in priority 399999 ptype main
        mark 0x6/0xffffffff
        tmpl src 2001:db8:3::2 dst 2001:db8:1::1
                proto esp reqid 1 mode tunnel
[ ]
Those policies are used for any source or destination as long as the firewall mark is equal to 6, which matches the mark configured for the tunnel interface. The last step is to configure BGP to exchange routes. We can use BIRD for this:
router id 1.0.1.1;
protocol device  
   scan time 10;
 
protocol kernel  
   persist;
   learn;
   import all;
   export all;
   merge paths yes;
 
protocol bgp IBGP_V3_2  
   local 2001:db8:ff::6 as 65001;
   neighbor 2001:db8:ff::7 as 65003;
   import all;
   export where ifname ~ "eth*";
   preference 160;
   hold time 6;
 
Once BIRD is started in the private namespace, we can check routes are learned correctly:
$ ip netns exec private ip -6 route show 2001:db8:a3::/64
2001:db8:a3::/64 proto bird metric 1024
        nexthop via 2001:db8:ff::5  dev vti5 weight 1
        nexthop via 2001:db8:ff::7  dev vti6 weight 1
The above route was learnt from both V3-1 (through vti5) and V3-2 (through vti6). Like for the JunOS version, there is no route-leaking between the private namespace and the initial one. The VPN cannot be used as a gateway between the two namespaces, only for encapsulation. This also prevent a misconfiguration (for example, IKE daemon not running) from allowing packets to leave the private network. As a bonus, unencrypted traffic can be observed with tcpdump on the tunnel interface:
$ ip netns exec private tcpdump -pni vti6 icmp6
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on vti6, link-type LINUX_SLL (Linux cooked), capture size 262144 bytes
20:51:15.258708 IP6 2001:db8:a1::1 > 2001:db8:a3::1: ICMP6, echo request, seq 69
20:51:15.260874 IP6 2001:db8:a3::1 > 2001:db8:a1::1: ICMP6, echo reply, seq 69
You can find all the configuration files for this example on GitHub. The documentation of strongSwan also features a page about route-based VPNs.

  1. Everything in this post should work with Libreswan.
  2. fwd is for incoming packets on non-local addresses. It only makes sense in transport mode and is a Linux-only particularity.
  3. Virtual tunnel interfaces (VTI) were introduced in Linux 3.6 (for IPv4) and Linux 3.12 (for IPv6). Appropriate namespace support was added in 3.15. KLIPS, an alternative out-of-tree stack available since Linux 2.2, also features tunnel interfaces.
  4. The mark is set right before doing a policy lookup and restored after that. Consequently, it doesn t affect other possible uses (filtering, routing). However, as Netfilter can also set a mark, one should be careful for conflicts.
  5. The ciphers used here are the strongest ones currently possible while keeping compatibility with JunOS. The documentation for strongSwan contains a complete list of supported algorithms as well as security recommendations to choose them.

Reproducible builds folks: Reproducible Builds: Weekly report #124

Here's what happened in the Reproducible Builds effort between Sunday September 3 and Saturday September 9 2017: Media coverage GSoC and Outreachy updates Debian will participate in this year's Outreachy initiative and the Reproducible Builds is soliciting mentors and students to join this round. For more background please see the following mailing list posts: 1, 2 & 3. Reproduciblity work in Debian In addition, the following NMUs were accepted: Reproduciblity work in other projects Patches sent upstream: Packages reviewed and fixed, and bugs filed Reviews of unreproducible packages 3 package reviews have been added, 2 have been updated and 2 have been removed in this week, adding to our knowledge about identified issues. Weekly QA work During our reproducibility testing, FTBFS bugs have been detected and reported by: diffoscope development Development continued in git, including the following contributions: Mattia Rizzolo also uploaded the version 86 released last week to stretch-backports. reprotest development tests.reproducible-builds.org Misc. This week's edition was written by Bernhard M. Wiedemann, Chris Lamb, Holger Levsen, Mattia Rizzolo & reviewed by a bunch of Reproducible Builds folks on IRC & the mailing lists.

11 September 2017

Steinar H. Gunderson: rANS encoding of signed coefficients

I'm currently trying to make sense of some still image coding (more details to come at a much later stage!), and for a variety of reasons, I've chosen to use rANS as the entropy coder. However, there's an interesting little detail that I haven't actually seen covered anywhere; maybe it's just because I've missed something, or maybe because it's too blindingly obvious, but I thought I would document what I ended up with anyway. (I had hoped for something even more elegant, but I guess the obvious would have to do.) For those that don't know rANS coding, let me try to handwave it as much as possible. Your state is typically a single word (in my case, a 32-bit word), which is refilled from the input stream as needed. The encoder and decoder works in reverse order; let's just talk about the decoder. Basically it works by looking at the lowest 12 (or whatever) bits of the decoder state, mapping each of those 2^12 slots to a decoded symbol. More common symbols are given more slots, proportionally to the frequency. Let me just write a tiny, tiny example with 2 bits and three symbols instead, giving four slots:
Lowest bits Symbol
00 0
01 0
10 1
11 2
Note that the zero coefficient here maps to one out of two slots (ie., a range); you don't choose which one yourself, the encoder stashes some information in there (which is used to recover the next control word once you know which symbol there is). Now for the actual problem: When storing DCT coefficients, we typically want to also store a sign (ie., not just 1 or 2, but also -1/+1 and -2/+2). The statistical distribution is symmetrical, so the sign bit is incompressible (except that of course there's no sign bit needed for 0). We could have done this by introducing new symbols -1 and -2 in addition to our three other ones, but this means we'll need more bits of precision, and accordingly larger look-up tables (which is negative for performance). So let's find something better. We could also simply store it separately somehow; if the coefficient is non-zero, store the bits in some separate repository. Perhaps more elegantly, you can encode a second symbol in the rANS stream with probability 1/2, but this is more expensive computationally. But both of these have the problem that they're divergent in terms of control flow; nonzero coefficients potentially need to do a lot of extra computation and even loads. This isn't nice for SIMD, and it's not nice for GPU. It's generally not really nice. The solution I ended up with was simulating a larger table with a smaller one. Simply rotate the table so that the zero symbol has the top slots instead of the bottom slots, and then replicate the rest of the table. For instance, take this new table:
Lowest bits Symbol
000 1
001 2
010 0
011 0
100 0
101 0
110 -1
111 -2
(The observant reader will note that this doesn't describe the exact same distribution as last time zero has twice the relative frequency as in the other table but ignore that for the time being.) In this case, the bottom half of the table doesn't actually need to be stored! We know that if the three bottom bits are >= 110 (6 in decimal), we have a negative value, can subtract 6, and then continue decoding. If we are go past the end of our 2-bit table despite that, we know we are decoding a zero coefficient (which doesn't have a sign), so we can just clamp the read; or for a GPU, reads out-of-bounds on a texture will typically return 0 anyway. So it all works nicely, and the divergent I/O is gone. If this pickled your interest, you probably want to read up on rANS in general; Fabian Giesen (aka ryg) has some notes that work as a good starting point, but beware; some of this is pretty confusing. :-)

10 September 2017

Steve Kemp: Debian-Administration.org is closing down

After 13 years the Debian-Administration website will be closing down towards the end of the year. The site will go read-only at the end of the month, and will slowly be stripped back from that point towards the end of the year - leaving only a static copy of the articles, and content. This is largely happening due to lack of content. There were only two articles posted last year, and every time I consider writing more content I lose my enthusiasm. There was a time when people contributed articles, but these days they tend to post such things on their own blogs, on medium, on Reddit, etc. So it seems like a good time to retire things. An official notice has been posted on the site-proper.

Adnan Hodzic: Secure traffic to ZNC on Synology with Let s Encrypt

I ve been using IRC since late 1990 s, and I continue to do so to this day due to it (still) being one of the driving development forces in various open source communities. Especially in Linux development and some of my acquintances I can only get in touch with via IRC :) My Setup On my Synology NAS I run ZNC (IRC bouncer/proxy) to which I connect using various IRC clients (irssi/XChat Azure/AndChat) from various platforms (Linux/Mac/Android). In this case ZNC serves as a gateway and no matter which device/client I connect from, I m always connected to same IRC servers/chat rooms/settings when I left off. This is all fine and dandy, but connecting from external networks to ZNC means you will hand in your ZNC credentials in plain text. Which is a problem for me, even thought we re only talking about IRC bouncer/proxy. With that said, how do we encrypt external traffic to our ZNC? HowTo: Chat securely with ZNC on Synology using Let s Encrypt SSL certificate For reference or more thorough explanation of some of the steps/topics please refer to: Secure (HTTPS) public access to Synology NAS using Let s Encrypt (free) SSL certificate

Requirements:

1: DNS setup Create A record for sub/domain you d like to use to connect to your ZNC and point it to your Synology NAS external (WAN) IP. For your reference, subdomain I ll use is: irc.hodzic.org 2: Create Let s Encrypt certificate
DSM: Control Panel > Security > Certificates > Add
Followed by:
Add a new certificate > Get a certificate from Let's Encrypt
Followed by adding domain name A record was created for in Step 1, i.e: Get a certificate from Let's Encrypt for irc.hodzic.org After certificate is created, don t forget to configure newly created certificate to point to correct domain name, i.e: Configure Let's Encrypt Certificate 3: Install ZNC In case you already have ZNC installed, I suggest you remove it and do a clean install. Mainly due to some problems with package in past, where ZNC wouldn t start automatically on boot which lead to creating projects like: synology-znc-autostart. In latest version, all of these problems have been fixed and couple of new features have been added. ZNC can be installed using Synology s Package Center, if community package sources are enabled. Which can simply be done by adding new package sources:
Name: SynoCommunity
Location: http://packages.synocommunity.com
Enable Community package sources in Synology Package Center To successfuly authenticate newly added source, under General tab, Trust Level should be set to Any publisher As part of installation process, ZNC config will be run with most sane/useful options and admin user will be created allowing you access to ZNC webadmin. 4: Secure access to ZNC webadmin Now we want to bind our sub/domain created in Step 1 to ZNC webadmin, and secure external access to it. This can be done by creating a reverse proxy. As part of this, you need to know which port has been allocated for SSL in ZNC Webadmin, i.e: ZNC Webadmin > Global settings - Listen Ports In this case, we can see it s 8251. Reverse Proxy can be created in:
DSM: Control Panel > Application Portal > Reverse Proxy > Create
Where sub/domain created in Step 1 needs to be point to ZNC SSL port on localhost, i.e: Reverse proxy: irc.hodzic.org setup ZNC Webadmin is now available via HTTPS on external network for the sub/domain you setup as part of Step 1, or in my case: ZNC webadmin (HTTPS) As part of this step, in ZNC webadmin I d advise you to create IRC servers and chatrooms you would like to connect to later. Step 5: Create .pem file from LetsEncrpyt certificate for ZNC to use On Synology, Let s Encrypt certificates are stored and located on:
/usr/syno/etc/certificate/_archive/
In case you have multiple certificates, based on date your certificate was created, you can determine in which directory is your newly generated certificated stored, i.e:
drwx------ 2 root root 4096 Sep 10 12:57 JeRh3Y
Once it s determined which certifiate is the one we want use, generate .pem by running following: sudo cat /usr/syno/etc/certificate/_archive/JeRh3Y/ privkey,cert,chain .pem > /usr/local/znc/var/znc.pem After this restart ZNC: sudo /var/packages/znc/scripts/start-stop-status stop && sudo /var/packages/znc/scripts/start-stop-status start 6: Configure IRC client In this example I ll use XChat Azure on MacOS, and same procedure should be identical for HexChat/XChat clients on any other platform. Altough all information is picked up from ZNC itself, user details will need to be filled in. In my setup I automatically connect to freenode and oftc networks, so I created two for local network and two for external network usage, later is the one we re concentrating on. On General tab of our newly created server, hostname for our server should be the sub/domain we ve setup as part of Step 1 , and port number should be the one we defined in Step 4 , SSL checkbox must be checked. Xchat Azure: Network list - General tab On Connecting tab Server password field needs to be filled in following format:
johndoe/freenode:password
Where, johndoe is ZNC username. freenode is ZNC network name, and password is ZNC password. Xchat Azure: Network list - Connecting tab freenode in this case must first be created as part of ZNC webadmin configuration, mentioned in step 4 . Same case is for oftc network configuration. As part of establishing the connection, information about our Let s Encrypt certificate will be displayed, after which connection will be established and you ll be automatically logged into all chatrooms. Happy hacking!

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