X-Git-Url: http://pere.pagekite.me/gitweb/homepage.git/blobdiff_plain/6b0c1fa519b278178825b3b550343129140b2ca7..f8d49bb59302ba8de63e67fcd752c0263619772c:/blog/index.rss diff --git a/blog/index.rss b/blog/index.rss index d2a8c98f0b..4629eda765 100644 --- a/blog/index.rss +++ b/blog/index.rss @@ -7,767 +7,636 @@ - Some notes on fault tolerant storage systems - http://people.skolelinux.org/pere/blog/Some_notes_on_fault_tolerant_storage_systems.html - http://people.skolelinux.org/pere/blog/Some_notes_on_fault_tolerant_storage_systems.html - Wed, 1 Nov 2017 15:35:00 +0100 - <p>If you care about how fault tolerant your storage is, you might -find these articles and papers interesting. They have formed how I -think of when designing a storage system.</p> - -<ul> - -<li>USENIX :login; <a -href="https://www.usenix.org/publications/login/summer2017/ganesan">Redundancy -Does Not Imply Fault Tolerance. Analysis of Distributed Storage -Reactions to Single Errors and Corruptions</a> by Aishwarya Ganesan, -Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, and Remzi -H. Arpaci-Dusseau</li> - -<li>ZDNet -<a href="http://www.zdnet.com/article/why-raid-5-stops-working-in-2009/">Why -RAID 5 stops working in 2009</a> by Robin Harris</li> - -<li>ZDNet -<a href="http://www.zdnet.com/article/why-raid-6-stops-working-in-2019/">Why -RAID 6 stops working in 2019</a> by Robin Harris</li> - -<li>USENIX FAST'07 -<a href="http://research.google.com/archive/disk_failures.pdf">Failure -Trends in a Large Disk Drive Population</a> by Eduardo Pinheiro, -Wolf-Dietrich Weber and Luiz André Barroso</li> - -<li>USENIX ;login: <a -href="https://www.usenix.org/system/files/login/articles/hughes12-04.pdf">Data -Integrity. Finding Truth in a World of Guesses and Lies</a> by Doug -Hughes</li> - -<li>USENIX FAST'08 -<a href="https://www.usenix.org/events/fast08/tech/full_papers/bairavasundaram/bairavasundaram_html/">An -cAnalysis of Data Corruption in the Storage Stack</a> - -L. N. Bairavasundaram, G. R. Goodson, B. Schroeder, A. C. -Arpaci-Dusseau, and R. H. Arpaci-Dusseau</li> - -<li>USENIX FAST'07 <a -href="https://www.usenix.org/legacy/events/fast07/tech/schroeder/schroeder_html/">Disk -failures in the real world: what does an MTTF of 1,000,000 hours mean -to you?</a> by B. Schroeder and G. A. Gibson.</li> - -<li>USENIX ;login: <a -href="https://www.usenix.org/events/fast08/tech/full_papers/jiang/jiang_html/">Are -Disks the Dominant Contributor for Storage Failures? A Comprehensive -Study of Storage Subsystem Failure Characteristics</a> by Weihang -Jiang, Chongfeng Hu, Yuanyuan Zhou, and Arkady Kanevsky</li> - -<li>SIGMETRICS 2007 -<a href="http://research.cs.wisc.edu/adsl/Publications/latent-sigmetrics07.pdf">An -analysis of latent sector errors in disk drives</a> - -L. N. Bairavasundaram, G. R. Goodson, S. Pasupathy, and J. Schindler</li> - -</ul> - -<p>Several of these research papers are based on data collected from -hundred thousands or millions of disk, and their findings are eye -opening. The short story is simply do not implicitly trust RAID or -redundant storage systems. Details matter. And unfortunately there -are few options on Linux addressing all the identified issues. Both -ZFS and Btrfs are doing a fairly good job, but have legal and -practical issues on their own. I wonder how cluster file systems like -Ceph do in this regard.</p> - -<p>Just remember, in the end, it do not matter how redundant, or how -fault tolerant your storage is, if you do not continuously monitor its -status to detect and replace failed disks.</p> + Streaming the Linux desktop to Kodi using VLC and RTSP + http://people.skolelinux.org/pere/blog/Streaming_the_Linux_desktop_to_Kodi_using_VLC_and_RTSP.html + http://people.skolelinux.org/pere/blog/Streaming_the_Linux_desktop_to_Kodi_using_VLC_and_RTSP.html + Thu, 12 Jul 2018 02:00:00 +0200 + <p>A while back, I was asked by a friend how to stream the desktop to +my projector connected to Kodi. I sadly had to admit that I had no +idea, as it was a task I never had tried. Since then, I have been +looking for a way to do so, preferable without much extra software to +install on either side. Today I found a way that seem to kind of +work. Not great, but it is a start.</p> + +<p>I had a look at several approaches, for example +<a href="https://github.com/mfoetsch/dlna_live_streaming">using uPnP +DLNA as described in 2011</a>, but it required a uPnP server, fuse and +local storage enough to store the stream locally. This is not going +to work well for me, lacking enough free space, and it would +impossible for my friend to get working.</p> + +<p>Next, it occurred to me that perhaps I could use VLC to create a +video stream that Kodi could play. Preferably using +broadcast/multicast, to avoid having to change any setup on the Kodi +side when starting such stream. Unfortunately, the only recipe I +could find using multicast used the rtp protocol, and this protocol +seem to not be supported by Kodi.</p> + +<p>On the other hand, the rtsp protocol is working! Unfortunately I +have to specify the IP address of the streaming machine in both the +sending command and the file on the Kodi server. But it is showing my +desktop, and thus allow us to have a shared look on the big screen at +the programs I work on.</p> + +<p>I did not spend much time investigating codeces. I combined the +rtp and rtsp recipes from +<a href="https://wiki.videolan.org/Documentation:Streaming_HowTo/Command_Line_Examples/">the +VLC Streaming HowTo/Command Line Examples</a>, and was able to get +this working on the desktop/streaming end.</p> + +<blockquote><pre> +vlc screen:// --sout \ + '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128}:rtp{dst=projector.local,port=1234,sdp=rtsp://192.168.11.4:8080/test.sdp}' +</pre></blockquote> + +<p>I ssh-ed into my Kodi box and created a file like this with the +same IP address:</p> + +<blockquote><pre> +echo rtsp://192.168.11.4:8080/test.sdp \ + > /storage/videos/screenstream.m3u +</pre></blockquote> + +<p>Note the 192.168.11.4 IP address is my desktops IP address. As far +as I can tell the IP must be hardcoded for this to work. In other +words, if someone elses machine is going to do the steaming, you have +to update screenstream.m4u on the Kodi machine and adjust the vlc +recipe. To get started, locate the file in Kodi and select the m3u +file while the VLC stream is running. The desktop then show up in my +big screen. :)</p> + +<p>When using the same technique to stream a video file with audio, +the audio quality is really bad. No idea if the problem is package +loss or bad parameters for the transcode. I do not know VLC nor Kodi +enough to tell.</p> + +<p><strong>Update 2018-07-12</strong>: Johannes Schauer send me a few +succestions and reminded me about an important step. The "screen:" +input source is only available once the vlc-plugin-access-extra +package is installed on Debian. Without it, you will see this error +message: "VLC is unable to open the MRL 'screen://'. Check the log +for details." He further found that it is possible to drop some parts +of the VLC command line to reduce the amount of hardcoded information. +It is also useful to consider using cvlc to avoid having the VLC +window in the desktop view. In sum, this give us this command line on +the source end + +<blockquote><pre> +cvlc screen:// --sout \ + '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128}:rtp{sdp=rtsp://:8080/}' +</pre></blockquote> + +<p>and this on the Kodi end<p> + +<blockquote><pre> +echo rtsp://192.168.11.4:8080/ \ + > /storage/videos/screenstream.m3u +</pre></blockquote> + +<p>Still bad image quality, though. But I did discover that streaming +a DVD using dvdsimple:///dev/dvd as the source had excellent video and +audio quality, so I guess the issue is in the input or transcoding +parts, not the rtsp part. I've tried to change the vb and ab +parameters to use more bandwidth, but it did not make a +difference.</p> + +<p>I further received a suggestion from Einar Haraldseid to try using +gstreamer instead of VLC, and this proved to work great! He also +provided me with the trick to get Kodi to use a multicast stream as +its source. By using this monstrous oneliner, I can stream my desktop +with good video quality in reasonable framerate to the 239.255.0.1 +multicast address on port 1234: + +<blockquote><pre> +gst-launch-1.0 ximagesrc use-damage=0 ! video/x-raw,framerate=30/1 ! \ + videoconvert ! queue2 ! \ + x264enc bitrate=8000 speed-preset=superfast tune=zerolatency qp-min=30 \ + key-int-max=15 bframes=2 ! video/x-h264,profile=high ! queue2 ! \ + mpegtsmux alignment=7 name=mux ! rndbuffersize max=1316 min=1316 ! \ + udpsink host=239.255.0.1 port=1234 ttl-mc=0 auto-multicast=1 sync=0 \ + pulsesrc device=$(pactl list | grep -A2 'Source #' | \ + grep 'Name: .*\.monitor$' | cut -d" " -f2|head -1) ! \ + audioconvert ! queue2 ! avenc_aac ! queue2 ! mux. +</pre></blockquote> + +<p>and this on the Kodi end<p> + +<blockquote><pre> +echo udp://@239.255.0.1:1234 \ + > /storage/videos/screenstream.m3u +</pre></blockquote> + +<p>Note the trick to pick a valid pulseaudio source. It might not +pick the one you need. This approach will of course lead to trouble +if more than one source uses the same multicast port and address. +Note the ttl-mc=0 setting, which limit the multicast packages to the +local network. If the value is increased, your screen will be +broadcasted further, one network "hop" for each increase (read up on +multicast to learn more. :)!</p> + +<p>Having cracked how to get Kodi to receive multicast streams, I +could use this VLC command to stream to the same multicast address. +The image quality is way better than the rtsp approach.</p> + +<blockquote><pre> +cvlc screen:// --sout '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128}:rtp{mux=ts,dst=239.255.0.1,port=1234,sdp=sap}' +</pre></blockquote> + +<p>As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p> - Web services for writing academic LaTeX papers as a team - http://people.skolelinux.org/pere/blog/Web_services_for_writing_academic_LaTeX_papers_as_a_team.html - http://people.skolelinux.org/pere/blog/Web_services_for_writing_academic_LaTeX_papers_as_a_team.html - Tue, 31 Oct 2017 21:00:00 +0100 - <p>I was surprised today to learn that a friend in academia did not -know there are easily available web services available for writing -LaTeX documents as a team. I thought it was common knowledge, but to -make sure at least my readers are aware of it, I would like to mention -these useful services for writing LaTeX documents. Some of them even -provide a WYSIWYG editor to ease writing even further.</p> - -<p>There are two commercial services available, -<a href="https://sharelatex.com">ShareLaTeX</a> and -<a href="https://overleaf.com">Overleaf</a>. They are very easy to -use. Just start a new document, select which publisher to write for -(ie which LaTeX style to use), and start writing. Note, these two -have announced their intention to join forces, so soon it will only be -one joint service. I've used both for different documents, and they -work just fine. While -<a href="https://github.com/sharelatex/sharelatex">ShareLaTeX is free -software</a>, while the latter is not. According to <a -href="https://www.overleaf.com/help/17-is-overleaf-open-source">a -announcement from Overleaf</a>, they plan to keep the ShareLaTeX code -base maintained as free software.</p> - -But these two are not the only alternatives. -<a href="https://app.fiduswriter.org/">Fidus Writer</a> is another free -software solution with <a href="https://github.com/fiduswriter">the -source available on github</a>. I have not used it myself. Several -others can be found on the nice -<a href="https://alternativeto.net/software/sharelatex/">alterntiveTo -web service</a>. - -<p>If you like Google Docs or Etherpad, but would like to write -documents in LaTeX, you should check out these services. You can even -host your own, if you want to. :)</p> - + What is the most supported MIME type in Debian in 2018? + http://people.skolelinux.org/pere/blog/What_is_the_most_supported_MIME_type_in_Debian_in_2018_.html + http://people.skolelinux.org/pere/blog/What_is_the_most_supported_MIME_type_in_Debian_in_2018_.html + Mon, 9 Jul 2018 08:05:00 +0200 + <p>Five years ago, +<a href="http://people.skolelinux.org/pere/blog/What_is_the_most_supported_MIME_type_in_Debian_.html">I +measured what the most supported MIME type in Debian was</a>, by +analysing the desktop files in all packages in the archive. Since +then, the DEP-11 AppStream system has been put into production, making +the task a lot easier. This made me want to repeat the measurement, +to see how much things changed. Here are the new numbers, for +unstable only this time: + +<p><strong>Debian Unstable:</strong></p> + +<pre> + count MIME type + ----- ----------------------- + 56 image/jpeg + 55 image/png + 49 image/tiff + 48 image/gif + 39 image/bmp + 38 text/plain + 37 audio/mpeg + 34 application/ogg + 33 audio/x-flac + 32 audio/x-mp3 + 30 audio/x-wav + 30 audio/x-vorbis+ogg + 29 image/x-portable-pixmap + 27 inode/directory + 27 image/x-portable-bitmap + 27 audio/x-mpeg + 26 application/x-ogg + 25 audio/x-mpegurl + 25 audio/ogg + 24 text/html +</pre> + +<p>The list was created like this using a sid chroot: "cat +/var/lib/apt/lists/*sid*_dep11_Components-amd64.yml.gz| zcat | awk '/^ +- \S+\/\S+$/ {print $2 }' | sort | uniq -c | sort -nr | head -20"</p> + +<p>It is interesting to see how image formats have passed text/plain +as the most announced supported MIME type. These days, thanks to the +AppStream system, if you run into a file format you do not know, and +want to figure out which packages support the format, you can find the +MIME type of the file using "file --mime &lt;filename&gt;", and then +look up all packages announcing support for this format in their +AppStream metadata (XML or .desktop file) using "appstreamcli +what-provides mimetype &lt;mime-type&gt;. For example if you, like +me, want to know which packages support inode/directory, you can get a +list like this:</p> + +<p><blockquote><pre> +% appstreamcli what-provides mimetype inode/directory | grep Package: | sort +Package: anjuta +Package: audacious +Package: baobab +Package: cervisia +Package: chirp +Package: dolphin +Package: doublecmd-common +Package: easytag +Package: enlightenment +Package: ephoto +Package: filelight +Package: gwenview +Package: k4dirstat +Package: kaffeine +Package: kdesvn +Package: kid3 +Package: kid3-qt +Package: nautilus +Package: nemo +Package: pcmanfm +Package: pcmanfm-qt +Package: qweborf +Package: ranger +Package: sirikali +Package: spacefm +Package: spacefm +Package: vifm +% +</pre></blockquote></p> + +<p>Using the same method, I can quickly discover that the Sketchup file +format is not yet supported by any package in Debian:</p> + +<p><blockquote><pre> +% appstreamcli what-provides mimetype application/vnd.sketchup.skp +Could not find component providing 'mimetype::application/vnd.sketchup.skp'. +% +</pre></blockquote></p> + +<p>Yesterday I used it to figure out which packages support the STL 3D +format:</p> + +<p><blockquote><pre> +% appstreamcli what-provides mimetype application/sla|grep Package +Package: cura +Package: meshlab +Package: printrun +% +</pre></blockquote></p> + +<p>PS: A new version of Cura was uploaded to Debian yesterday.</p> + +<p>As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p> - Locating IMDB IDs of movies in the Internet Archive using Wikidata - http://people.skolelinux.org/pere/blog/Locating_IMDB_IDs_of_movies_in_the_Internet_Archive_using_Wikidata.html - http://people.skolelinux.org/pere/blog/Locating_IMDB_IDs_of_movies_in_the_Internet_Archive_using_Wikidata.html - Wed, 25 Oct 2017 12:20:00 +0200 - <p>Recently, I needed to automatically check the copyright status of a -set of <a href="http://www.imdb.com/">The Internet Movie database -(IMDB)</a> entries, to figure out which one of the movies they refer -to can be freely distributed on the Internet. This proved to be -harder than it sounds. IMDB for sure list movies without any -copyright protection, where the copyright protection has expired or -where the movie is lisenced using a permissive license like one from -Creative Commons. These are mixed with copyright protected movies, -and there seem to be no way to separate these classes of movies using -the information in IMDB.</p> - -<p>First I tried to look up entries manually in IMDB, -<a href="https://www.wikipedia.org/">Wikipedia</a> and -<a href="https://www.archive.org/">The Internet Archive</a>, to get a -feel how to do this. It is hard to know for sure using these sources, -but it should be possible to be reasonable confident a movie is "out -of copyright" with a few hours work per movie. As I needed to check -almost 20,000 entries, this approach was not sustainable. I simply -can not work around the clock for about 6 years to check this data -set.</p> - -<p>I asked the people behind The Internet Archive if they could -introduce a new metadata field in their metadata XML for IMDB ID, but -was told that they leave it completely to the uploaders to update the -metadata. Some of the metadata entries had IMDB links in the -description, but I found no way to download all metadata files in bulk -to locate those ones and put that approach aside.</p> - -<p>In the process I noticed several Wikipedia articles about movies -had links to both IMDB and The Internet Archive, and it occured to me -that I could use the Wikipedia RDF data set to locate entries with -both, to at least get a lower bound on the number of movies on The -Internet Archive with a IMDB ID. This is useful based on the -assumption that movies distributed by The Internet Archive can be -legally distributed on the Internet. With some help from the RDF -community (thank you DanC), I was able to come up with this query to -pass to <a href="https://query.wikidata.org/">the SPARQL interface on -Wikidata</a>: - -<p><pre> -SELECT ?work ?imdb ?ia ?when ?label -WHERE -{ - ?work wdt:P31/wdt:P279* wd:Q11424. - ?work wdt:P345 ?imdb. - ?work wdt:P724 ?ia. - OPTIONAL { - ?work wdt:P577 ?when. - ?work rdfs:label ?label. - FILTER(LANG(?label) = "en"). - } + Debian APT upgrade without enough free space on the disk... + http://people.skolelinux.org/pere/blog/Debian_APT_upgrade_without_enough_free_space_on_the_disk___.html + http://people.skolelinux.org/pere/blog/Debian_APT_upgrade_without_enough_free_space_on_the_disk___.html + Sun, 8 Jul 2018 12:10:00 +0200 + <p>Quite regularly, I let my Debian Sid/Unstable chroot stay untouch +for a while, and when I need to update it there is not enough free +space on the disk for apt to do a normal 'apt upgrade'. I normally +would resolve the issue by doing 'apt install &lt;somepackages&gt;' to +upgrade only some of the packages in one batch, until the amount of +packages to download fall below the amount of free space available. +Today, I had about 500 packages to upgrade, and after a while I got +tired of trying to install chunks of packages manually. I concluded +that I did not have the spare hours required to complete the task, and +decided to see if I could automate it. I came up with this small +script which I call 'apt-in-chunks':</p> + +<p><blockquote><pre> +#!/bin/sh +# +# Upgrade packages when the disk is too full to upgrade every +# upgradable package in one lump. Fetching packages to upgrade using +# apt, and then installing using dpkg, to avoid changing the package +# flag for manual/automatic. + +set -e + +ignore() { + if [ "$1" ]; then + grep -v "$1" + else + cat + fi } -</pre></p> - -<p>If I understand the query right, for every film entry anywhere in -Wikpedia, it will return the IMDB ID and The Internet Archive ID, and -when the movie was released and its English title, if either or both -of the latter two are available. At the moment the result set contain -2338 entries. Of course, it depend on volunteers including both -correct IMDB and The Internet Archive IDs in the wikipedia articles -for the movie. It should be noted that the result will include -duplicates if the movie have entries in several languages. There are -some bogus entries, either because The Internet Archive ID contain a -typo or because the movie is not available from The Internet Archive. -I did not verify the IMDB IDs, as I am unsure how to do that -automatically.</p> - -<p>I wrote a small python script to extract the data set from Wikidata -and check if the XML metadata for the movie is available from The -Internet Archive, and after around 1.5 hour it produced a list of 2097 -free movies and their IMDB ID. In total, 171 entries in Wikidata lack -the refered Internet Archive entry. I assume the 70 "disappearing" -entries (ie 2338-2097-171) are duplicate entries.</p> - -<p>This is not too bad, given that The Internet Archive report to -contain <a href="https://archive.org/details/feature_films">5331 -feature films</a> at the moment, but it also mean more than 3000 -movies are missing on Wikipedia or are missing the pair of references -on Wikipedia.</p> - -<p>I was curious about the distribution by release year, and made a -little graph to show how the amount of free movies is spread over the -years:<p> - -<p><img src="http://people.skolelinux.org/pere/blog/images/2017-10-25-verk-i-det-fri-filmer.png"></p> - -<p>I expect the relative distribution of the remaining 3000 movies to -be similar.</p> - -<p>If you want to help, and want to ensure Wikipedia can be used to -cross reference The Internet Archive and The Internet Movie Database, -please make sure entries like this are listed under the "External -links" heading on the Wikipedia article for the movie:</p> - -<p><pre> -* {{Internet Archive film|id=FightingLady}} -* {{IMDb title|id=0036823|title=The Fighting Lady}} -</pre></p> -<p>Please verify the links on the final page, to make sure you did not -introduce a typo.</p> - -<p>Here is the complete list, if you want to correct the 171 -identified Wikipedia entries with broken links to The Internet -Archive: <a href="http://www.wikidata.org/entity/Q1140317">Q1140317</a>, -<a href="http://www.wikidata.org/entity/Q458656">Q458656</a>, -<a href="http://www.wikidata.org/entity/Q458656">Q458656</a>, -<a href="http://www.wikidata.org/entity/Q470560">Q470560</a>, -<a href="http://www.wikidata.org/entity/Q743340">Q743340</a>, -<a href="http://www.wikidata.org/entity/Q822580">Q822580</a>, -<a href="http://www.wikidata.org/entity/Q480696">Q480696</a>, -<a href="http://www.wikidata.org/entity/Q128761">Q128761</a>, -<a href="http://www.wikidata.org/entity/Q1307059">Q1307059</a>, -<a href="http://www.wikidata.org/entity/Q1335091">Q1335091</a>, -<a 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href="http://www.wikidata.org/entity/Q3372642">Q3372642</a>, -<a href="http://www.wikidata.org/entity/Q3372816">Q3372816</a>, -<a href="http://www.wikidata.org/entity/Q3372909">Q3372909</a>, -<a href="http://www.wikidata.org/entity/Q7959649">Q7959649</a>, -<a href="http://www.wikidata.org/entity/Q7977485">Q7977485</a>, -<a href="http://www.wikidata.org/entity/Q7992684">Q7992684</a>, -<a href="http://www.wikidata.org/entity/Q3817966">Q3817966</a>, -<a href="http://www.wikidata.org/entity/Q3821852">Q3821852</a>, -<a href="http://www.wikidata.org/entity/Q3420907">Q3420907</a>, -<a href="http://www.wikidata.org/entity/Q3429733">Q3429733</a>, -<a href="http://www.wikidata.org/entity/Q774474">Q774474</a></p> +for p in $(apt list --upgradable | ignore "$@" |cut -d/ -f1 | grep -v '^Listing...'); do + echo "Upgrading $p" + apt clean + apt install --download-only -y $p + for f in /var/cache/apt/archives/*.deb; do + if [ -e "$f" ]; then + dpkg -i /var/cache/apt/archives/*.deb + break + fi + done +done +</pre></blockquote></p> + +<p>The script will extract the list of packages to upgrade, try to +download the packages needed to upgrade one package, install the +downloaded packages using dpkg. The idea is to upgrade packages +without changing the APT mark for the package (ie the one recording of +the package was manually requested or pulled in as a dependency). To +use it, simply run it as root from the command line. If it fail, try +'apt install -f' to clean up the mess and run the script again. This +might happen if the new packages conflict with one of the old +packages. dpkg is unable to remove, while apt can do this.</p> + +<p>It take one option, a package to ignore in the list of packages to +upgrade. The option to ignore a package is there to be able to skip +the packages that are simply too large to unpack. Today this was +'ghc', but I have run into other large packages causing similar +problems earlier (like TeX).</p> + +<p>Update 2018-07-08: Thanks to Paul Wise, I am aware of two +alternative ways to handle this. The "unattended-upgrades +--minimal-upgrade-steps" option will try to calculate upgrade sets for +each package to upgrade, and then upgrade them in order, smallest set +first. It might be a better option than my above mentioned script. +Also, "aptutude upgrade" can upgrade single packages, thus avoiding +the need for using "dpkg -i" in the script above.</p> + +<p>As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p> - A one-way wall on the border? - http://people.skolelinux.org/pere/blog/A_one_way_wall_on_the_border_.html - http://people.skolelinux.org/pere/blog/A_one_way_wall_on_the_border_.html - Sat, 14 Oct 2017 22:10:00 +0200 - <p>I find it fascinating how many of the people being locked inside -the proposed border wall between USA and Mexico support the idea. The -proposal to keep Mexicans out reminds me of -<a href="http://www.history.com/news/10-things-you-may-not-know-about-the-berlin-wall">the -propaganda twist from the East Germany government</a> calling the wall -the “Antifascist Bulwark” after erecting the Berlin Wall, claiming -that the wall was erected to keep enemies from creeping into East -Germany, while it was obvious to the people locked inside it that it -was erected to keep the people from escaping.</p> - -<p>Do the people in USA supporting this wall really believe it is a -one way wall, only keeping people on the outside from getting in, -while not keeping people in the inside from getting out?</p> + The worlds only stone power plant? + http://people.skolelinux.org/pere/blog/The_worlds_only_stone_power_plant_.html + http://people.skolelinux.org/pere/blog/The_worlds_only_stone_power_plant_.html + Sat, 30 Jun 2018 10:35:00 +0200 + <p>So far, at least hydro-electric power, coal power, wind power, +solar power, and wood power are well known. Until a few days ago, I +had never heard of stone power. Then I learn about a quarry in a +mountain in +<a href="https://en.wikipedia.org/wiki/Bremanger">Bremanger</a> i +Norway, where +<a href="https://www.bontrup.com/en/activities/raw-materials/bremanger-quarry/">the +Bremanger Quarry</a> company is extracting stone and dumping the stone +into a shaft leading to its shipping harbour. This downward movement +in this shaft is used to produce electricity. In short, it is using +falling rocks instead of falling water to produce electricity, and +according to its own statements it is producing more power than it is +using, and selling the surplus electricity to the Norwegian power +grid. I find the concept truly amazing. Is this the worlds only +stone power plant?</p> + +<p>As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p> - Generating 3D prints in Debian using Cura and Slic3r(-prusa) - http://people.skolelinux.org/pere/blog/Generating_3D_prints_in_Debian_using_Cura_and_Slic3r__prusa_.html - http://people.skolelinux.org/pere/blog/Generating_3D_prints_in_Debian_using_Cura_and_Slic3r__prusa_.html - Mon, 9 Oct 2017 10:50:00 +0200 - <p>At my nearby maker space, -<a href="http://sonen.ifi.uio.no/">Sonen</a>, I heard the story that it -was easier to generate gcode files for theyr 3D printers (Ultimake 2+) -on Windows and MacOS X than Linux, because the software involved had -to be manually compiled and set up on Linux while premade packages -worked out of the box on Windows and MacOS X. I found this annoying, -as the software involved, -<a href="https://github.com/Ultimaker/Cura">Cura</a>, is free software -and should be trivial to get up and running on Linux if someone took -the time to package it for the relevant distributions. I even found -<a href="https://bugs.debian.org/706656">a request for adding into -Debian</a> from 2013, which had seem some activity over the years but -never resulted in the software showing up in Debian. So a few days -ago I offered my help to try to improve the situation.</p> - -<p>Now I am very happy to see that all the packages required by a -working Cura in Debian are uploaded into Debian and waiting in the NEW -queue for the ftpmasters to have a look. You can track the progress -on -<a href="https://qa.debian.org/developer.php?email=3dprinter-general%40lists.alioth.debian.org">the -status page for the 3D printer team</a>.</p> - -<p>The uploaded packages are a bit behind upstream, and was uploaded -now to get slots in <a href="https://ftp-master.debian.org/new.html">the NEW -queue</a> while we work up updating the packages to the latest -upstream version.</p> - -<p>On a related note, two competitors for Cura, which I found harder -to use and was unable to configure correctly for Ultimaker 2+ in the -short time I spent on it, are already in Debian. If you are looking -for 3D printer "slicers" and want something already available in -Debian, check out -<a href="https://tracker.debian.org/pkg/slic3r">slic3r</a> and -<a href="https://tracker.debian.org/pkg/slic3r-prusa">slic3r-prusa</a>. -The latter is a fork of the former.</p> + Add-on to control the projector from within Kodi + http://people.skolelinux.org/pere/blog/Add_on_to_control_the_projector_from_within_Kodi.html + http://people.skolelinux.org/pere/blog/Add_on_to_control_the_projector_from_within_Kodi.html + Tue, 26 Jun 2018 23:55:00 +0200 + <p>My movie playing setup involve <a href="https://kodi.tv/">Kodi</a>, +<a href="https://openelec.tv">OpenELEC</a> (probably soon to be +replaced with <a href="https://libreelec.tv/">LibreELEC</a>) and an +Infocus IN76 video projector. My projector can be controlled via both +a infrared remote controller, and a RS-232 serial line. The vendor of +my projector, <a href="https://www.infocus.com/">InFocus</a>, had been +sensible enough to document the serial protocol in its user manual, so +it is easily available, and I used it some years ago to write +<a href="https://github.com/petterreinholdtsen/infocus-projector-control">a +small script to control the projector</a>. For a while now, I longed +for a setup where the projector was controlled by Kodi, for example in +such a way that when the screen saver went on, the projector was +turned off, and when the screen saver exited, the projector was turned +on again.</p> + +<p>A few days ago, with very good help from parts of my family, I +managed to find a Kodi Add-on for controlling a Epson projector, and +got in touch with its author to see if we could join forces and make a +Add-on with support for several projectors. To my pleasure, he was +positive to the idea, and we set out to add InFocus support to his +add-on, and make the add-on suitable for the official Kodi add-on +repository.</p> + +<p>The Add-on is now working (for me, at least), with a few minor +adjustments. The most important change I do relative to the master +branch in the github repository is embedding the +<a href="https://github.com/pyserial/pyserial">pyserial module</a> in +the add-on. The long term solution is to make a "script" type +pyserial module for Kodi, that can be pulled in as a dependency in +Kodi. But until that in place, I embed it.</p> + +<p>The add-on can be configured to turn on the projector when Kodi +starts, off when Kodi stops as well as turn the projector off when the +screensaver start and on when the screesaver stops. It can also be +told to set the projector source when turning on the projector. + +<p>If this sound interesting to you, check out +<a href="https://github.com/fredrik-eriksson/kodi_projcontrol">the +project github repository</a>. Perhaps you can send patches to +support your projector too? As soon as we find time to wrap up the +latest changes, it should be available for easy installation using any +Kodi instance.</p> + +<p>For future improvements, I would like to add projector model +detection and the ability to adjust the brightness level of the +projector from within Kodi. We also need to figure out how to handle +the cooling period of the projector. My projector refuses to turn on +for 60 seconds after it was turned off. This is not handled well by +the add-on at the moment.</p> + +<p>As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p> - Mangler du en skrue, eller har du en skrue løs? - http://people.skolelinux.org/pere/blog/Mangler_du_en_skrue__eller_har_du_en_skrue_l_s_.html - http://people.skolelinux.org/pere/blog/Mangler_du_en_skrue__eller_har_du_en_skrue_l_s_.html - Wed, 4 Oct 2017 09:40:00 +0200 - Når jeg holder på med ulike prosjekter, så trenger jeg stadig ulike -skruer. Det siste prosjektet jeg holder på med er å lage -<a href="https://www.thingiverse.com/thing:676916">en boks til en -HDMI-touch-skjerm</a> som skal brukes med Raspberry Pi. Boksen settes -sammen med skruer og bolter, og jeg har vært i tvil om hvor jeg kan -få tak i de riktige skruene. Clas Ohlson og Jernia i nærheten har -sjelden hatt det jeg trenger. Men her om dagen fikk jeg et fantastisk -tips for oss som bor i Oslo. -<a href="http://www.zachskruer.no/">Zachariassen Jernvare AS</a> i -<a href="http://www.openstreetmap.org/?mlat=59.93421&mlon=10.76795#map=19/59.93421/10.76795">Hegermannsgate -23A på Torshov</a> har et fantastisk utvalg, og åpent mellom 09:00 og -17:00. De selger skruer, muttere, bolter, skiver etc i løs vekt, og -så langt har jeg fått alt jeg har lett etter. De har i tillegg det -meste av annen jernvare, som verktøy, lamper, ledninger, etc. Jeg -håper de har nok kunder til å holde det gående lenge, da dette er en -butikk jeg kommer til å besøke ofte. Butikken er et funn å ha i -nabolaget for oss som liker å bygge litt selv. :)</p> + youtube-dl for nedlasting fra NRK med undertekster - nice free software + http://people.skolelinux.org/pere/blog/youtube_dl_for_nedlasting_fra_NRK_med_undertekster___nice_free_software.html + http://people.skolelinux.org/pere/blog/youtube_dl_for_nedlasting_fra_NRK_med_undertekster___nice_free_software.html + Sat, 28 Apr 2018 10:30:00 +0200 + <p>I <a href="https://no.wikipedia.org/wiki/VHS">VHS-kassettenes</a> +tid var det rett frem å ta vare på et TV-program en ønsket å kunne se +senere, uten å være avhengig av at programmet ble sendt på nytt. +Kanskje ønsket en å se programmet på hytten der det ikke var +TV-signal, eller av andre grunner ha det tilgjengelig for fremtidig +fornøyelse. Dette er blitt vanskeligere med introduksjon av +digital-TV og webstreaming, der opptak til harddisk er utenfor de +flestes kontroll hvis de bruker ufri programvare og bokser kontrollert +av andre. Men for NRK her i Norge, finnes det heldigvis flere fri +programvare-alternativer, som jeg har +<a href="http://people.skolelinux.org/pere/blog/Hvordan_enkelt_laste_ned_filmer_fra_NRK.html">skrevet</a> +<a href="http://people.skolelinux.org/pere/blog/Hvordan_enkelt_laste_ned_filmer_fra_NRK_med_den__nye__l_sningen.html">om</a> +<a href="http://people.skolelinux.org/pere/blog/Nedlasting_fra_NRK__som_Matroska_med_undertekster.html">før</a>. +Så lenge kilden for nedlastingen er lovlig lagt ut på nett (hvilket +jeg antar NRK gjør), så er slik lagring til privat bruk også lovlig i +Norge.</p> + +<p>Sist jeg så på saken, i 2016, nevnte jeg at +<a href="https://rg3.github.com/youtube-dl/">youtube-dl</a> ikke kunne +bake undertekster fra NRK inn i videofilene, og at jeg derfor +foretrakk andre alternativer. Nylig oppdaget jeg at dette har endret +seg. Fordelen med youtube-dl er at den er tilgjengelig direkte fra +Linux-distribusjoner som <a href="https://www.debian.org/">Debian</a> +og <a href="https://www.ubuntu.com/">Ubuntu</a>, slik at en slipper å +finne ut selv hvordan en skal få dem til å virke.</p> + +<p>For å laste ned et NRK-innslag med undertekster, og få den norske +underteksten pakket inn i videofilen, så kan følgende kommando +brukes:</p> + +<p><pre> +youtube-dl --write-sub --sub-format ttml \ + --convert-subtitles srt --embed-subs \ + https://tv.nrk.no/serie/ramm-ferdig-gaa/MUHU11000316/27-04-2018 +</pre></p> + +<p>URL-eksemplet er dagens toppsak på tv.nrk.no. Resultatet er en +MP4-fil med filmen og undertekster som kan spilles av med VLC. Merk +at VLC ikke viser frem undertekster før du aktiverer dem. For å gjøre +det, høyreklikk med musa i fremviservinduet, velg menyvalget for +undertekst og så norsk språk. Jeg testet også '--write-auto-sub', +men det kommandolinjeargumentet ser ikke ut til å fungere, så jeg +endte opp med settet med argumentlisten over, som jeg fant i en +feilrapport i youtube-dl-prosjektets samling over feilrapporter.</p> + +<p>Denne støtten i youtube-dl gjør det svært enkelt å lagre +NRK-innslag, det være seg nyheter, filmer, serier eller dokumentater, +for å ha dem tilgjengelig for fremtidig referanse og bruk, uavhengig +av hvor lenge innslagene ligger tilgjengelig hos NRK. Så får det ikke +hjelpe at NRKs jurister mener at det er +<a href="http://people.skolelinux.org/pere/blog/Best___ikke_fortelle_noen_at_streaming_er_nedlasting___.html">vesensforskjellig +å legge tilgjengelig for nedlasting og for streaming</a>, når det rent +teknisk er samme sak.</p> + +<p>Programmet youtube-dl støtter også en rekke andre nettsteder, se +prosjektoversikten for +<a href="http://rg3.github.io/youtube-dl/supportedsites.html">en +komplett liste</a>.</p> - Visualizing GSM radio chatter using gr-gsm and Hopglass - http://people.skolelinux.org/pere/blog/Visualizing_GSM_radio_chatter_using_gr_gsm_and_Hopglass.html - http://people.skolelinux.org/pere/blog/Visualizing_GSM_radio_chatter_using_gr_gsm_and_Hopglass.html - Fri, 29 Sep 2017 10:30:00 +0200 - <p>Every mobile phone announce its existence over radio to the nearby -mobile cell towers. And this radio chatter is available for anyone -with a radio receiver capable of receiving them. Details about the -mobile phones with very good accuracy is of course collected by the -phone companies, but this is not the topic of this blog post. The -mobile phone radio chatter make it possible to figure out when a cell -phone is nearby, as it include the SIM card ID (IMSI). By paying -attention over time, one can see when a phone arrive and when it leave -an area. I believe it would be nice to make this information more -available to the general public, to make more people aware of how -their phones are announcing their whereabouts to anyone that care to -listen.</p> - -<p>I am very happy to report that we managed to get something -visualizing this information up and running for -<a href="http://norwaymakers.org/osf17">Oslo Skaperfestival 2017</a> -(Oslo Makers Festival) taking place today and tomorrow at Deichmanske -library. The solution is based on the -<a href="http://people.skolelinux.org/pere/blog/Easier_recipe_to_observe_the_cell_phones_around_you.html">simple -recipe for listening to GSM chatter</a> I posted a few days ago, and -will show up at the stand of <a href="http://sonen.ifi.uio.no/">Åpen -Sone from the Computer Science department of the University of -Oslo</a>. The presentation will show the nearby mobile phones (aka -IMSIs) as dots in a web browser graph, with lines to the dot -representing mobile base station it is talking to. It was working in -the lab yesterday, and was moved into place this morning.</p> - -<p>We set up a fairly powerful desktop machine using Debian -Buster/Testing with several (five, I believe) RTL2838 DVB-T receivers -connected and visualize the visible cell phone towers using an -<a href="https://github.com/marlow925/hopglass">English version of -Hopglass</a>. A fairly powerfull machine is needed as the -grgsm_livemon_headless processes from -<a href="https://tracker.debian.org/pkg/gr-gsm">gr-gsm</a> converting -the radio signal to data packages is quite CPU intensive.</p> - -<p>The frequencies to listen to, are identified using a slightly -patched scan-and-livemon (to set the --args values for each receiver), -and the Hopglass data is generated using the -<a href="https://github.com/petterreinholdtsen/IMSI-catcher/tree/meshviewer-output">patches -in my meshviewer-output branch</a>. For some reason we could not get -more than four SDRs working. There is also a geographical map trying -to show the location of the base stations, but I believe their -coordinates are hardcoded to some random location in Germany, I -believe. The code should be replaced with code to look up location in -a text file, a sqlite database or one of the online databases -mentioned in -<a href="https://github.com/Oros42/IMSI-catcher/issues/14">the github -issue for the topic</a>. - -<p>If this sound interesting, visit the stand at the festival!</p> + Stortingsflertallet går inn for ny IP-basert sensurinfrastruktur i Norge + http://people.skolelinux.org/pere/blog/Stortingsflertallet_g_r_inn_for_ny_IP_basert_sensurinfrastruktur_i_Norge.html + http://people.skolelinux.org/pere/blog/Stortingsflertallet_g_r_inn_for_ny_IP_basert_sensurinfrastruktur_i_Norge.html + Tue, 24 Apr 2018 15:00:00 +0200 + <p><a href="https://www.vg.no/sport/i/J1g8zj/stortingsvedtak-snart-ip-blokkerer-utenlandske-spillselskaper">VG</a>, +<a href="https://www.dagbladet.no/nyheter/stortinget-blokkerer-utenlandske-spillselskaper/69740219">Dagbladet</a> +og +<a href="https://www.nrk.no/ostfold/tar-opp-kampen-mot-utenlandske-spillselskap-1.14021381">NRK</a> +melder i dag at flertallet i Familie- og kulturkomiteen på Stortinget +har bestemt seg for å introdusere en ny sensurinfrastruktur i Norge. +Fra før har Norge en «frivillig» sensurinfrastruktur basert på +DNS-navn, der de største ISP-ene basert på en liste med DNS-navn +forgifter DNS-svar og omdirigerer til et annet IP-nummer enn det som +ligger i DNS. Nå kommer altså IP-basert omdirigering i tillegg. Når +infrastrukturen er på plass, er sensur av IP-adresser redusert et +spørsmål om hvilke IP-nummer som skal blokkeres. Listen over +IP-adresser vil naturligvis endre seg etter hvert som myndighetene +endrer seg. Det er ingen betryggende tanke.</p> - Easier recipe to observe the cell phones around you - http://people.skolelinux.org/pere/blog/Easier_recipe_to_observe_the_cell_phones_around_you.html - http://people.skolelinux.org/pere/blog/Easier_recipe_to_observe_the_cell_phones_around_you.html - Sun, 24 Sep 2017 08:30:00 +0200 - <p>A little more than a month ago I wrote -<a href="http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html">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</a>, 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.</p> - -<p>The <a href="https://tracker.debian.org/pkg/gr-gsm">gr-gsm</a> -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.</p> - -<p>Here is an updated recipe, using packages built by Debian and a git -clone of two python scripts:</p> - -<ol> - -<li>Start with a Debian machine running the Buster version (aka - testing).</li> - -<li>Run '<tt>apt install gr-gsm python-numpy python-scipy - python-scapy</tt>' as root to install required packages.</li> - -<li>Fetch the code decoding GSM packages using '<tt>git clone - github.com/Oros42/IMSI-catcher.git</tt>'.</li> - -<li>Insert USB software defined radio supported by GNU Radio.</li> - -<li>Enter the IMSI-catcher directory and run '<tt>python - scan-and-livemon</tt>' to locate the frequency of nearby base - stations and start listening for GSM packages on one of them.</li> - -<li>Enter the IMSI-catcher directory and run '<tt>python - simple_IMSI-catcher.py</tt>' to display the collected information.</li> - -</ol> - -<p>Note, due to a bug somewhere the scan-and-livemon program (actually -<a href="https://github.com/ptrkrysik/gr-gsm/issues/336">its underlying -program grgsm_scanner</a>) do not work with the HackRF radio. It does -work with RTL 8232 and other similar USB radio receivers you can get -very cheaply -(<a href="https://www.ebay.com/sch/items/?_nkw=rtl+2832">for example -from ebay</a>), so for now the solution is to scan using the RTL radio -and only use HackRF for fetching GSM data.</p> - -<p>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.</p> - -<p>I've tried to run the scanner on a -<a href="https://wiki.debian.org/RaspberryPi">Raspberry Pi 2 and 3 -running Debian Buster</a>, 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().</p> + En grunn til å takke nei til usikker digital post + http://people.skolelinux.org/pere/blog/En_grunn_til___takke_nei_til_usikker_digital_post.html + http://people.skolelinux.org/pere/blog/En_grunn_til___takke_nei_til_usikker_digital_post.html + Mon, 2 Apr 2018 13:30:00 +0200 + <p>Brevpost er beskyttet av straffelovens bestemmelse som gjør det +kriminelt å åpne andres brev. Dette følger av (ny) straffelovs +<a href="https://lovdata.no/dokument/NL/lov/2005-05-20-28/§205">§ 205 +(Krenkelse av retten til privat kommunikasjon)</a>, som sier at «Med +bot eller fengsel inntil 2 år straffes den som uberettiget ... c) +åpner brev eller annen lukket skriftlig meddelelse som er adressert +til en annen, eller på annen måte skaffer seg uberettiget tilgang til +innholdet.» Dette gjelder såvel postbud som alle andre som har +befatning med brevet etter at avsender har befatning med et lukket +brev. Tilsvarende står også tidligere utgaver av den norske +straffeloven.</p> + +<p>Når en registrerer seg på usikre digitale postkasseløsningene, som +f.eks. Digipost og e-Boks, og slik tar disse i bruk, så gir en de som +står bak løsningene tillatelse til å åpne sine brev. Dette er +nødvendig for at innholdet i digital post skal kunne vises frem til +mottaker via tjenestens websider. Dermed gjelder ikke straffelovens +paragraf om forbud mot å åpne brev, da tilgangen ikke lenger er +uberettiget. En gir altså fremmede tilgang til å lese sin +korrespondanse. I tillegg vil bruk av slike usikre digitale +postbokser føre til at det blir registrert når du leser brevene, hvor +du befinner deg (vha. tilkoblingens IP-adresse), hvilket utstyr du +bruker og en rekke annen personlig informasjon som ikke er +tilgjengelig når papirpost brukes. Jeg foretrekker at det er +lovmessig beskyttelse av min korrespondanse, som jo inneholder privat +og personlig informasjon. Det bidrar til litt bedre vern av personlig +integritet i dagens norske samfunn.</p> - Datalagringsdirektivet kaster skygger over Høyre og Arbeiderpartiet - http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_kaster_skygger_over_H_yre_og_Arbeiderpartiet.html - http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_kaster_skygger_over_H_yre_og_Arbeiderpartiet.html - Thu, 7 Sep 2017 21:35:00 +0200 - <p>For noen dager siden publiserte Jon Wessel-Aas en bloggpost om -«<a href="http://www.uhuru.biz/?p=1821">Konklusjonen om datalagring som -EU-kommisjonen ikke ville at vi skulle få se</a>». Det er en -interessant gjennomgang av EU-domstolens syn på snurpenotovervåkning -av befolkningen, som er klar på at det er i strid med -EU-lovgivingen.</p> - -<p>Valgkampen går for fullt i Norge, og om noen få dager er siste -frist for å avgi stemme. En ting er sikkert, Høyre og Arbeiderpartiet -får ikke min stemme -<a href="http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_gj_r_at_Oslo_H_yre_og_Arbeiderparti_ikke_f_r_min_stemme_i__r.html">denne -gangen heller</a>. Jeg har ikke glemt at de tvang igjennom loven som -skulle pålegge alle data- og teletjenesteleverandører å overvåke alle -sine kunder. En lov som er vedtatt, og aldri opphevet igjen.</p> - -<p>Det er tydelig fra diskusjonen rundt grenseløs digital overvåkning -(eller "Digital Grenseforsvar" som det kalles i Orvellisk nytale) at -hverken Høyre og Arbeiderpartiet har noen prinsipielle sperrer mot å -overvåke hele befolkningen, og diskusjonen så langt tyder på at flere -av de andre partiene heller ikke har det. Mange av -<a href="https://data.holderdeord.no/votes/1301946411e">de som stemte -for Datalagringsdirektivet i Stortinget</a> (64 fra Arbeiderpartiet, -25 fra Høyre) er fortsatt aktive og argumenterer fortsatt for å radere -vekk mer av innbyggernes privatsfære.</p> - -<p>Når myndighetene demonstrerer sin mistillit til folket, tror jeg -folket selv bør legge litt innsats i å verne sitt privatliv, ved å ta -i bruk ende-til-ende-kryptert kommunikasjon med sine kjente og kjære, -og begrense hvor mye privat informasjon som deles med uvedkommende. -Det er jo ingenting som tyder på at myndighetene kommer til å være vår -privatsfære. -<a href="http://people.skolelinux.org/pere/blog/How_to_talk_with_your_loved_ones_in_private.html">Det -er mange muligheter</a>. Selv har jeg litt sans for -<a href="https://ring.cx/">Ring</a>, som er basert på p2p-teknologi -uten sentral kontroll, er fri programvare, og støtter meldinger, tale -og video. Systemet er tilgjengelig ut av boksen fra -<a href="https://tracker.debian.org/pkg/ring">Debian</a> og -<a href="https://launchpad.net/ubuntu/+source/ring">Ubuntu</a>, og det -finnes pakker for Android, MacOSX og Windows. Foreløpig er det få -brukere med Ring, slik at jeg også bruker -<a href="https://signal.org/">Signal</a> som nettleserutvidelse.</p> + Self-appointed leaders of the Free World + http://people.skolelinux.org/pere/blog/Self_appointed_leaders_of_the_Free_World.html + http://people.skolelinux.org/pere/blog/Self_appointed_leaders_of_the_Free_World.html + Thu, 22 Mar 2018 11:00:00 +0100 + <p>The leaders of the worlds have started to congratulate the +re-elected Russian head of state, and this causes some criticism. I +am though a little fascinated by a comment from USA senator John McCain, +<a href="http://thehill.com/homenews/senate/379339-mccain-rips-trumps-congratulatory-call-to-putin-as-insult-to-russian-people">sited +by The Hill and others</a>: + +<p><blockquote> +<p>"An American president does not lead the Free World by +congratulating dictators on winning sham elections."</p> +</blockquote></p> + +<p>While I totally agree with the senator here, the way the quote is +phrased make me suspect that he is unaware of the simple fact that USA +have not lead the Free World since at least before its government +<a href="https://en.wikipedia.org/wiki/Maher_Arar">kidnapped a +completely innocent Canadian citizen in transit on his way home to +Canada via John F. Kennedy International Airport in September 2002 and +sent him to be tortured in Syria for a year</a>.</p> + +<p>USA might be running ahead, but the path they are taking is not the +one taken by any Free World.</p> - Simpler recipe on how to make a simple $7 IMSI Catcher using Debian - http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html - http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html - Wed, 9 Aug 2017 23:59:00 +0200 - <p>On friday, I came across an interesting article in the Norwegian -web based ICT news magazine digi.no on -<a href="https://www.digi.no/artikler/sikkerhetsforsker-lagde-enkel-imsi-catcher-for-60-kroner-na-kan-mobiler-kartlegges-av-alle/398588">how -to collect the IMSI numbers of nearby cell phones</a> using the cheap -DVB-T software defined radios. The article refered to instructions -and <a href="https://www.youtube.com/watch?v=UjwgNd_as30">a recipe by -Keld Norman on Youtube on how to make a simple $7 IMSI Catcher</a>, and I decided to test them out.</p> - -<p>The instructions said to use Ubuntu, install pip using apt (to -bypass apt), use pip to install pybombs (to bypass both apt and pip), -and the ask pybombs to fetch and build everything you need from -scratch. I wanted to see if I could do the same on the most recent -Debian packages, but this did not work because pybombs tried to build -stuff that no longer build with the most recent openssl library or -some other version skew problem. While trying to get this recipe -working, I learned that the apt->pip->pybombs route was a long detour, -and the only piece of software dependency missing in Debian was the -gr-gsm package. I also found out that the lead upstream developer of -gr-gsm (the name stand for GNU Radio GSM) project already had a set of -Debian packages provided in an Ubuntu PPA repository. All I needed to -do was to dget the Debian source package and built it.</p> - -<p>The IMSI collector is a python script listening for packages on the -loopback network device and printing to the terminal some specific GSM -packages with IMSI numbers in them. The code is fairly short and easy -to understand. The reason this work is because gr-gsm include a tool -to read GSM data from a software defined radio like a DVB-T USB stick -and other software defined radios, decode them and inject them into a -network device on your Linux machine (using the loopback device by -default). This proved to work just fine, and I've been testing the -collector for a few days now.</p> - -<p>The updated and simpler recipe is thus to</p> - -<ol> - -<li>start with a Debian machine running Stretch or newer,</li> - -<li>build and install the gr-gsm package available from -<a href="http://ppa.launchpad.net/ptrkrysik/gr-gsm/ubuntu/pool/main/g/gr-gsm/">http://ppa.launchpad.net/ptrkrysik/gr-gsm/ubuntu/pool/main/g/gr-gsm/</a>,</li> - -<li>clone the git repostory from <a href="https://github.com/Oros42/IMSI-catcher">https://github.com/Oros42/IMSI-catcher</a>,</li> - -<li>run grgsm_livemon and adjust the frequency until the terminal -where it was started is filled with a stream of text (meaning you -found a GSM station).</li> - -<li>go into the IMSI-catcher directory and run 'sudo python simple_IMSI-catcher.py' to extract the IMSI numbers.</li> - -</ol> - -<p>To make it even easier in the future to get this sniffer up and -running, I decided to package -<a href="https://github.com/ptrkrysik/gr-gsm/">the gr-gsm project</a> -for Debian (<a href="https://bugs.debian.org/871055">WNPP -#871055</a>), and the package was uploaded into the NEW queue today. -Luckily the gnuradio maintainer has promised to help me, as I do not -know much about gnuradio stuff yet.</p> - -<p>I doubt this "IMSI cacher" is anywhere near as powerfull as -commercial tools like -<a href="https://www.thespyphone.com/portable-imsi-imei-catcher/">The -Spy Phone Portable IMSI / IMEI Catcher</a> or the -<a href="https://en.wikipedia.org/wiki/Stingray_phone_tracker">Harris -Stingray</a>, but I hope the existance of cheap alternatives can make -more people realise how their whereabouts when carrying a cell phone -is easily tracked. Seeing the data flow on the screen, realizing that -I live close to a police station and knowing that the police is also -wearing cell phones, I wonder how hard it would be for criminals to -track the position of the police officers to discover when there are -police near by, or for foreign military forces to track the location -of the Norwegian military forces, or for anyone to track the location -of government officials...</p> - -<p>It is worth noting that the data reported by the IMSI-catcher -script mentioned above is only a fraction of the data broadcasted on -the GSM network. It will only collect one frequency at the time, -while a typical phone will be using several frequencies, and not all -phones will be using the frequencies tracked by the grgsm_livemod -program. Also, there is a lot of radio chatter being ignored by the -simple_IMSI-catcher script, which would be collected by extending the -parser code. I wonder if gr-gsm can be set up to listen to more than -one frequency?</p> + Facebooks ability to sell your personal information is the real Cambridge Analytica scandal + http://people.skolelinux.org/pere/blog/Facebooks_ability_to_sell_your_personal_information_is_the_real_Cambridge_Analytica_scandal.html + http://people.skolelinux.org/pere/blog/Facebooks_ability_to_sell_your_personal_information_is_the_real_Cambridge_Analytica_scandal.html + Wed, 21 Mar 2018 16:30:00 +0100 + <p>So, Cambridge Analytica is getting some well deserved criticism for +(mis)using information it got from Facebook about 50 million people, +mostly in the USA. What I find a bit surprising, is how little +criticism Facebook is getting for handing the information over to +Cambridge Analytica and others in the first place. And what about the +people handing their private and personal information to Facebook? +And last, but not least, what about the government offices who are +handing information about the visitors of their web pages to Facebook? +No-one who looked at the terms of use of Facebook should be surprised +that information about peoples interests, political views, personal +lifes and whereabouts would be sold by Facebook.</p> + +<p>What I find to be the real scandal is the fact that Facebook is +selling your personal information, not that one of the buyers used it +in a way Facebook did not approve when exposed. It is well known that +Facebook is selling out their users privacy, but a scandal +nevertheless. Of course the information provided to them by Facebook +would be misused by one of the parties given access to personal +information about the millions of Facebook users. Collected +information will be misused sooner or later. The only way to avoid +such misuse, is to not collect the information in the first place. If +you do not want Facebook to hand out information about yourself for +the use and misuse of its customers, do not give Facebook the +information.</p> + +<p>Personally, I would recommend to completely remove your Facebook +account, and take back some control of your personal information. +<a href="https://www.theguardian.com/technology/2018/mar/19/how-to-protect-your-facebook-privacy-or-delete-yourself-completely">According +to The Guardian</a>, it is a bit hard to find out how to request +account removal (and not just 'disabling'). You need to +<a href="https://www.facebook.com/help/224562897555674?helpref=faq_content">visit +a specific Facebook page</a> and click on 'let us know' on that page +to get to <a href="https://www.facebook.com/help/delete_account">the +real account deletion screen</a>. Perhaps something to consider? I +would not trust the information to really be deleted (who knows, +perhaps NSA, GCHQ and FRA already got a copy), but it might reduce the +exposure a bit.</p> + +<p>If you want to learn more about the capabilities of Cambridge +Analytica, I recommend to see the video recording of the one hour talk +Paul-Olivier Dehaye gave to <a href="">NUUG</a> last april about +<a href="https://www.nuug.no/aktiviteter/20170404-big-data-psychometric/"> +Data collection, psychometric profiling and their impact on +politics</a>.</p> + +<p>And if you want to communicate with your friends and loved ones, +use some end-to-end encrypted method like +<a href="https://www.signal.org/">Signal</a> or +<a href="https://ring.cx/">Ring</a>, and stop sharing your private +messages with strangers like Facebook and Google.</p>