Search Results: "jan"

5 May 2017

Patrick Matth i: Be careful: Upgrading Debian Jessie to Stretch, with Pacemaker DRBD and an nested ext4 LVM hosted on VMware products

Detached DRBD (diskless) In the past I setup some new Pacemaker clustered nodes with a fresh Debian Stretch installation. I followed our standard installation guide, created also shared replicated DRBD storage, but whenever I tried to mount the ext4 storage DRBD detached the disks on both node sides with I/O errors. After recreating it, using other storage volumes and testing my ProLiant hardware (whop I thought it had got a defect..) it still occurs, but somewhere in the middle of testing, a quicker setup without LVM it worked fine, hum.. Much later I found this (only post at this time about it) on the DRBD-user mailinglist: [0]
This means, if you use the combination of VMware-Product -> Debian Stretch -> local Storage -> DRBD -> LVM -> ext4 you will be affected by this bug. This happens, because VMware always publishs the information, that the guest is able to support the WRITE SAME feature, which is wrong. Since the DRBD version, which is also shipped with Stretch, DRBD now also supports WRITE SAME, so it tries to use this feature, but this fails then.
This is btw the same reason, why VMware users see in their dmesg this: 
WRITE SAME failed.Manually zeroing.
As a workaround I am using now systemd, to disable WRITE SAME for all attached block devices in the guest. Simply run the following:
for i in find /sys/block/*/device/scsi_disk/*/max_write_same_blocks ; do echo w $i 0 ; done > /etc/tmpfiles.d/write_same.conf
[0]: http://lists.linbit.com/pipermail/drbd-user/2017-January/022931.html Pacemaker failovers with DRBD+LVM do not work If you use a DRBD with a nested LVM, you already had to add the following lines to your /etc/lvm/lvm.conf in past Debian releases (assuming that sdb and sdc are DRBD devices):
filter = [ r /dev/sdb.* /dev/sdc.* ]
write_cache_state = 0
Wit Debian Stretch this is not enough. Your failovers will result in a broken state on the second node, because it can not find your LVs and VGs. I found out, that killing lvmetad helps. So I also added a global_filter (it should be used for all LVM services):
global_filter = [ r /dev/sdb.* /dev/sdc.* ]
But this also didn t helped.. My only solution was to disable lvmetad (which I am also not using at all). So adding this all in combination works now for me and failovers are as smooth as with Jessie:
filter = [ r /dev/sdb.* /dev/sdc.* ]
global_filter = [ r /dev/sdb.* /dev/sdc.* ]
write_cache_state = 0
use_lvmetad = 0
Do not forget to update your initrd, so that the LVM configuration is updated on booting your server:
update-initramfs -k all -u
Reboot, that s it :)

3 May 2017

Reproducible builds folks: Reproducing R packages

In the past couple of weeks, Ximin Luo worked on making R generate reproducible output. This is now mostly complete, and we're waiting on feedback from upstream about our patch. In the meantime, there are a few packages that remain unreproducible, but the issue probably lies in those specific packages rather than the R toolchain. Perhaps you can help out with them, after reading this!
R packages compile into a .rdb database format that contains the package's definitions, plus a .rdx index file for easy lookup in the .rdb file. Usually, there is a main rdb with the package contents, plus another rdb that stores the help data. There is also a paths.rds (same format as .rdx) that contains some more stuff. One can actually read these files by hand using Rscript, see the diffoscope code in rdata.py. If you run that, you can see that path.rds contains some obvious paths, but the other files contain less obvious stuff, and in fact these scripts give identical output for the .rdb files, even though they are bitwise different. To get to the bottom of this, we'll have to use the R debugger. Attached to this post is a script that smooths this process. I ran this against Debian's R packages, but it probably also works with other distros' R packages - try it and see. You run it like ./r-mini-repro-test.sh $pkgdir $builddir and it will output some hashes for you; make sure to install the build dependencies first. You should manually vary both $pkgdir and $builddir to introduce the build-path variations; $builddir can be an arbitrary string but $pkgdir should point to the actual R package's source directory, so I just copy that to two locations and point the script at each of them in turn. Now, we can begin debugging. Before I did this, we had 478 unreproducible R packages so the biggest problem was likely with R itself. I downloaded the source code of both R and a small example package (r-cran-tensor), then figured out how the R packages were actually being built. This resulted in me writing the script above, to speed up debugging. You can read about R's debugger here (no HTTPS), it's a bit primitive but it supports the basic stuff (step, continue, where, print/eval) and that was adequate for me. Debugging R core So let's take a small example with Debian R 3.4.0-1: 
$ ../r-mini-repro-test.sh r-cran-tensor-1.5 123
[..]
* installing *source* package  tensor  ...
** package  tensor  successfully unpacked and MD5 sums checked
** R
** preparing package for lazy loading
** help
*** installing help indices
** building package indices
** testing if installed package can be loaded
* DONE (tensor)
[..]
c71a766429151a13e46039f3c37a14edc704004f410c34f8f37a2f098506421d  ./debian/123/usr/lib/R/site-library/tensor/R/tensor.rdx
736b5b4a885db71fb3fe2a538faeefe43c500c4080dbf2c75b97135b98401acd  ./debian/123/usr/lib/R/site-library/tensor/R/tensor.rdb
8a3f9616de7ee78a83b07395dd6ec43c5259d3f1b1b653d397808fc9fc5d96c2  ./debian/123/usr/lib/R/site-library/tensor/help/tensor.rdx
d1ac634987b24606a5da627ec073f45edce2bddf071391dd17c246a0a01eba63  ./debian/123/usr/lib/R/site-library/tensor/help/tensor.rdb
80796cc1a2cfcac40c394153f67617d575e103a405430b8483c2261a903db046  ./debian/123/usr/lib/R/site-library/tensor/help/paths.rds
$ ../r-mini-repro-test.sh r-cran-tensor-1.5 1234
[..]
5f081f4d6f9da1fbe06e374067e6636d926de4cdf09886058b15c5928c636c0d  ./debian/1234/usr/lib/R/site-library/tensor/R/tensor.rdx
7145669891e1b766ca0d8d89fa9c317af716e61a62650abe3a11a848240f1d57  ./debian/1234/usr/lib/R/site-library/tensor/R/tensor.rdb
8a3f9616de7ee78a83b07395dd6ec43c5259d3f1b1b653d397808fc9fc5d96c2  ./debian/1234/usr/lib/R/site-library/tensor/help/tensor.rdx
d1ac634987b24606a5da627ec073f45edce2bddf071391dd17c246a0a01eba63  ./debian/1234/usr/lib/R/site-library/tensor/help/tensor.rdb
80796cc1a2cfcac40c394153f67617d575e103a405430b8483c2261a903db046  ./debian/1234/usr/lib/R/site-library/tensor/help/paths.rds
The files are created by the ** preparing package for lazy loading and ** help steps. In retrospect this seems somewhat obvious from the output, but I had never done R before so I spent a while using strace to be sure; one can see that those files are indeed written to after those strings are printed. Then we can grep the R source code for these strings. 
r-base-3.4.0$ grep -Ri "preparing package for lazy loading" src
src/library/tools/R/install.R:                starsmsg(stars, "preparing package for lazy loading")
Reading the file, we see that this happens in the tools:::.install_packages function, and reading it further we see that it calls makeLazyLoading then code2LazyLoadDB then makeLazyLoadDB. Seems promising, let's confirm it before chasing potential wild geese. Important: In the rest of these command-line outputs I'll prepend what I input with >>> but this doesn't actually get printed by Rscript. So don't be surprised that you don't see these, when you're trying to recreate my steps. Also I am a total R noob so possibly there are more elegant ways to do what I'm about to show you; this is what I came up with after 2-3 hours of research. 
$ DEBUG=1 ../r-mini-repro-test.sh r-cran-tensor-1.5 123
enter (some or all of) the following into R:
[.. helpful commands ..]
+ R_DEFAULT_PACKAGES= LC_COLLATE=C /usr/lib/R/bin/R --no-restore --slave --args nextArg-lnextArgdebian/123/usr/lib/R/site-librarynextArg-dnextArg.nextArg--built-timestamp="Thu, 01 Jan 1970 00:00:00 +0000"
>>> debug(tools:::makeLazyLoadDB)
>>> tools:::.install_packages()
processing  . 
[..]
** preparing package for lazy loading
debugging in: makeLazyLoadDB(ns, dbbase, compress = compress)
debug:  
[.. source code of makeLazyLoadDB, not yet run ..]
OK so we just entered the function and it's paused, in a separate shell let's check what it's doing: 
$ find r-cran-tensor-1.5 -name '*.rdb'
[ no output ]
So, no files have been written yet, which means none of the parent functions did anything, we are in the right function (or it's in a child). If we continue the function, we get: 
>>> c
exiting from: makeLazyLoadDB(ns, dbbase, compress = compress)
** help
debugging in: makeLazyLoadDB(db, file.path(manOutDir, basename(outDir)))
debug:  
[.. source code of makeLazyLoadDB, not yet run ..]
 
$ find r-cran-tensor-1.5 -name '*.rdb'
r-cran-tensor-1.5/debian/123/usr/lib/R/site-library/tensor/R/tensor.rdb
Then continuing again: 
>>> c
exiting from: makeLazyLoadDB(db, file.path(manOutDir, basename(outDir)))
*** installing help indices
** building package indices
** testing if installed package can be loaded
* DONE (tensor)
$ find r-cran-tensor-1.5 -name '*.rdb'
r-cran-tensor-1.5/debian/123/usr/lib/R/site-library/tensor/help/tensor.rdb
r-cran-tensor-1.5/debian/123/usr/lib/R/site-library/tensor/R/tensor.rdb
So it seems likely this function is the correct one. After reading the source code of makeLazyLoadDB, even though I don't understand the whole thing, it looks like possibly this part is the one that does the actual writing: 
    for (i in seq_along(vars))  
        key <- if (is.null(from)   is.environment(from))
            lazyLoadDBinsertVariable(vars[i], from, datafile,
                                     ascii, compress,  envhook)
        else lazyLoadDBinsertListElement(from, i, datafile, ascii,
                                         compress, envhook)
        assign(vars[i], key, envir = varenv)
So let's step through it and see if the data contains any paths. 
$ DEBUG=1 ../r-mini-repro-test.sh r-cran-tensor-1.5 123
[..]
>>> debug(tools:::makeLazyLoadDB)
>>> tools:::.install_packages()
processing  . 
[..]
** preparing package for lazy loading
debugging in: makeLazyLoadDB(ns, dbbase, compress = compress)
debug:  
[.. source code of makeLazyLoadDB, not yet run ..]
 
>>>                                                                             # pressing <Enter> just means "step"
debug: ascii <- as.logical(ascii)                                               # this is the first line of the function
>>>                                                                             # keep stepping
[..]
>>>
debug: for (i in seq_along(vars))  
[.. source code of the inside of the block, not yet run ..]
 
>>>
debug: key <- if (is.null(from)   is.environment(from)) lazyLoadDBinsertVariable(vars[i],
    from, datafile, ascii, compress, envhook) else lazyLoadDBinsertListElement(from,
    i, datafile, ascii, compress, envhook)
>>>
debug: lazyLoadDBinsertVariable(vars[i], from, datafile, ascii, compress,
    envhook)                                                                    # not yet run
If we look at the source code we see that it will try to insert the value of .Internal(getVarsFromFrame(vars[i], from, FALSE))[[1L]] into the file, so let's evaluate it: 
>>> .Internal(getVarsFromFrame(vars[i], from, FALSE))[[1L]]
function (x, y)
tensor(x, y, 2, 2)
<environment: namespace:tensor>
>>> typeof(.Internal(getVarsFromFrame(vars[i], from, FALSE))[[1L]])
[1] "closure"
>>> environment(.Internal(getVarsFromFrame(vars[i], from, FALSE))[[1L]])        # get the environment of a closure
<environment: namespace:tensor>
>>> envlist(environment(.Internal(getVarsFromFrame(vars[i], from, FALSE))[[1L]])) # environment as an envlist, more detailed output
$ %*t% 
function (x, y)
tensor(x, y, 2, 2)
<environment: namespace:tensor>
$ %t*% 
function (x, y)
tensor(x, y, 1, 1)
<environment: namespace:tensor>
$ %t*t% 
function (x, y)
tensor(x, y, 1, 2)
<environment: namespace:tensor>
$.__NAMESPACE__.
<environment: 0x55eb55d00be0>
$.__S3MethodsTable__.
<environment: 0x55eb55d166e8>
$.packageName
[1] "tensor"
$tensor
function (A, B, alongA = integer(0), alongB = integer(0))
 
[.. function definition ..]
 
<environment: namespace:tensor>
Nothing obviously containing paths so far, let's keep stepping and dumping the objects 
>>>
debug: assign(vars[i], key, envir = varenv)
>>>                                                                             # next iteration now
debug: key <- if (is.null(from)   is.environment(from)) lazyLoadDBinsertVariable(vars[i],
    from, datafile, ascii, compress, envhook) else lazyLoadDBinsertListElement(from,
    i, datafile, ascii, compress, envhook)
>>>
debug: lazyLoadDBinsertVariable(vars[i], from, datafile, ascii, compress,
    envhook)
>>> .Internal(getVarsFromFrame(vars[i], from, FALSE))[[1L]]
function (x, y)
tensor(x, y, 1, 1)
<environment: namespace:tensor>
>>>
[.. more stepping ..]
debug: lazyLoadDBinsertVariable(vars[i], from, datafile, ascii, compress,
    envhook)
>>> .Internal(getVarsFromFrame(vars[i], from, FALSE))[[1L]]
<environment: 0x55eb55d00be0>
>>> envlist(.Internal(getVarsFromFrame(vars[i], from, FALSE))[[1L]])
$S3methods
     [,1] [,2] [,3]
$dynlibs
NULL
$exports
<environment: 0x55eb55d0a4f8>
$imports
$imports$base
[1] TRUE
$lazydata
<environment: 0x55eb55d0a178>
attr(,"name")
[1] "lazydata:tensor"
$path
[1] "/mystupidbuildpath/r-tests/r-cran-tensor-1.5/debian/123/usr/lib/R/site-library/tensor"
$spec
    name  version
"tensor"    "1.5"
Oh, here we go. (In fact we could have got this earlier, it was part of the .__NAMESPACE__. key of the first environment that we examined.) Naturally, you'll sometimes miss stuff, and sometimes go down dead ends when doing something like this, perseverence is important. The names are also a hint, after grepping the R source code for names like "S3methods" and "lazydata" we see that src/library/base/R/namespace.R is the only one that contains all of them, then reading that code in more depth reveals this. After patching it, rebuilding r-base, installing this patched version, then running our tests again, we see that we've eliminated differences in the main rdb file but not the help rdb file. :( In fact, after some more time stepping through the loop repeatedly and printing out all the objects, nothing obvious shows up. Time to re-read the source code of makeLazyLoadDB. We notice that all the lazyLoadDBinsert* functions have a hook parameter that we haven't been stepping through because it's in a separate function. So let's do that. Since it's an inner function, one has to call debug() inside makeLazyLoadDB: 
$ DEBUG=1 ../r-mini-repro-test.sh r-cran-tensor-1.5 123
[..]
>>> debug(tools:::makeLazyLoadDB)
>>> tools:::.install_packages()
processing  . 
[..]
** preparing package for lazy loading
debugging in: makeLazyLoadDB(ns, dbbase, compress = compress)
debug:  
[.. source code of makeLazyLoadDB, not yet run ..]
 
>>> c
exiting from: makeLazyLoadDB(ns, dbbase, compress = compress)
** help
debugging in: makeLazyLoadDB(db, file.path(manOutDir, basename(outDir)))
debug:  
[.. source code of makeLazyLoadDB, not yet run ..]
 
[.. stepping through the function ..]
debug: envhook <- function(e)  
[.. function definition ..]
 
>>>                                                                             # step next, to define that function
[.. next statement, we don't care about it ..]
>>> debug(envhook)
[.. then keep stepping through makeLazyLoadDB ..]
>>>
debug: lazyLoadDBinsertVariable(vars[i], from, datafile, ascii, compress,
    envhook)
[.. then keep stepping through makeLazyLoadDB ..]
debug: lazyLoadDBinsertVariable(vars[i], from, datafile, ascii, compress,
    envhook)
[.. hook wasn't run for these previous iterations for some reason, but keep stepping ..]
[.. eventually we get ..]
debugging in: (function (e)
 
[.. function definition ..]
 )(<environment>)                                                               # "(..)(<environment>)" is R's name for that function (actually a closure)
debug:  
[.. source code, not yet run ..]
 
>>> e
/mystupidbuildpath/r-tests/r-cran-tensor-1.5/man/tensor.Rd
>>> typeof(e)
[1] "environment"
>>> envlist(e)
$Enc
[1] "UTF-8"
$encoding
[1] ""
$filename
[1] "/mystupidbuildpath/r-tests/r-cran-tensor-1.5/man/tensor.Rd"
$timestamp
[1] "2002-01-16 11:51:14 CET"
$wd
[1] "/mystupidbuildpath/r-tests/r-cran-tensor-1.5"
After doing the same thing as before, i.e. grepping the R source code for "Enc" "timestamp" etc, we spot a few different places that are setting the wd field. Then after some experimenting, we find that overwriting this in a different file (src/library/tools/R/parseRd.R) seems to work to get rid of this irreproducibility. (This may not be the best; our exact strategy is still being discussed with upstream, but at least we know which areas of the code are responsible.) Exercise for the reader to figure out how to get rid of the paths.rds difference. After doing the previous two, this one is fairly easy. These three issues allowed us to write a preliminary patch that enabled us to reproduce r-cran-tensor. 
$ ./r-mini-repro-test.sh r-cran-tensor-1.5 123
[..]
bca9de1351ab265475cf6f1af3f6aff49bde1d209e8fafb33954caa8d90f3462  ./debian/123/usr/lib/R/site-library/tensor/R/tensor.rdx
ac7fffeb751ffc2d13c5317704b19787a7078446d97d1c6f259c93f282e04cef  ./debian/123/usr/lib/R/site-library/tensor/R/tensor.rdb
d989603340d1e8f14c35551ef379956653bf3b6e7b1868b4bf9a66d85820998e  ./debian/123/usr/lib/R/site-library/tensor/help/tensor.rdx
30e543cda9f97c202dc9c0291933940dfe71b94d352f66d8ed6c035c1a722b41  ./debian/123/usr/lib/R/site-library/tensor/help/tensor.rdb
e9f78ba2cca39a6face1ed88fce4bb718d911d567d01db49bc00a3011720ac50  ./debian/123/usr/lib/R/site-library/tensor/help/paths.rds
$ ./r-mini-repro-test.sh r-cran-tensor-1.5 1234
[..]
bca9de1351ab265475cf6f1af3f6aff49bde1d209e8fafb33954caa8d90f3462  ./debian/1234/usr/lib/R/site-library/tensor/R/tensor.rdx
ac7fffeb751ffc2d13c5317704b19787a7078446d97d1c6f259c93f282e04cef  ./debian/1234/usr/lib/R/site-library/tensor/R/tensor.rdb
d989603340d1e8f14c35551ef379956653bf3b6e7b1868b4bf9a66d85820998e  ./debian/1234/usr/lib/R/site-library/tensor/help/tensor.rdx
30e543cda9f97c202dc9c0291933940dfe71b94d352f66d8ed6c035c1a722b41  ./debian/1234/usr/lib/R/site-library/tensor/help/tensor.rdb
e9f78ba2cca39a6face1ed88fce4bb718d911d567d01db49bc00a3011720ac50  ./debian/1234/usr/lib/R/site-library/tensor/help/paths.rds
$ ./r-mini-repro-test.sh r-cran-tensor 1234
[..]
bca9de1351ab265475cf6f1af3f6aff49bde1d209e8fafb33954caa8d90f3462  ./debian/1234/usr/lib/R/site-library/tensor/R/tensor.rdx
ac7fffeb751ffc2d13c5317704b19787a7078446d97d1c6f259c93f282e04cef  ./debian/1234/usr/lib/R/site-library/tensor/R/tensor.rdb
d989603340d1e8f14c35551ef379956653bf3b6e7b1868b4bf9a66d85820998e  ./debian/1234/usr/lib/R/site-library/tensor/help/tensor.rdx
30e543cda9f97c202dc9c0291933940dfe71b94d352f66d8ed6c035c1a722b41  ./debian/1234/usr/lib/R/site-library/tensor/help/tensor.rdb
e9f78ba2cca39a6face1ed88fce4bb718d911d567d01db49bc00a3011720ac50  ./debian/1234/usr/lib/R/site-library/tensor/help/paths.rds
Testing the patch Of course r-cran-tensor is just 1 package, so then we tested this patch on all 478 tagged R packages. Before the patch, all of these were unreproducible. Now 463/478 are reproducible, hurray! The first version of the patch made 2 packages FTBFS ("fail to build from source"), r-bioc-biobase and r-cran-shinybs; this was fixed in a subsequent version of the patch. (Some other packages, r-cran-randomfields r-cran-randomfieldsutils, FTBFS even with an unpatched r-base, due to differences between 3.3.3 and 3.4.0 (#861333), and not because of our patch.) Given the overwhelming proportion of packages that did reproduce, the other 14 packages that are still unreproducible, are quite probably due to issues in those specific packages. Only 2 of these are certainly due to build-path differences: r-cran-runit r-cran-rinside. This is because, we currently see they are reproducible in Debian testing but not Debian unstable. This is slightly misleading, the real reason is not testing vs unstable directly; rather the fact that we (at the time of writing) use the same build path when trying to reproduce Debian testing packages, and different paths for unstable. The other 12 are unreproducible in both testing and unstable, so it either suffers from a non-build-path issue as well as a build-path issue, or only a non-build-path issue. So, further investigation of each package is needed. This is where you can help. :) Debugging R packages To investigate why (for example) r-cran-runit doesn't reproduce despite our patches, we just do the above process again: 
$ DEBUG=1 ../r-mini-repro-test.sh r-cran-runit
[..]
>>> debug(tools:::makeLazyLoadDB)
>>> tools:::.install_packages()
processing  . 
a directory
* build_help_types=
* DBG: 'R CMD INSTALL' now doing do_install()
* created lock directory  /mystupidbuildpath/r-tests/r-cran-runit/debian/r-cran-runit/usr/lib/R/site-library/00LOCK-r-cran-runit 
* installing *source* package  RUnit  ...
** package  RUnit  successfully unpacked and MD5 sums checked
** backing up earlier installation
** R
** inst
** preparing package for lazy loading
debugging in: makeLazyLoadDB(ns, dbbase, compress = compress)
debug:  
[.. source code of makeLazyLoadDB ..]
We know our irreproducibility is with the help files and not the main package, so c to skip this part: 
>>> c
exiting from: makeLazyLoadDB(ns, dbbase, compress = compress)
** help
debugging in: makeLazyLoadDB(db, file.path(manOutDir, basename(outDir)))
debug:  
[.. source code of makeLazyLoadDB ..]
Examine the "from" object, grep the output for our builddir 
>>> from
$ RUnit-internal 
[..]
$ RUnit-intro 
[..]
[.. etc ..]
[..]
$checkFuncs
\title RUnit check [..]
[..]
  For a simple example see the provided test cases in
  /mystupidbuildpath/r-tests/r-cran-runit/debian/r-cran-runit/usr/lib/R/site-library/RUnit/examples/runitVirtualClassTest.r.
[..]
Found it, now we quit, patch the source code, and try again. 
>>> Q
[..]
exit code 1
[.. hack hack hack ..]
$ ../r-mini-repro-test.sh r-cran-runit-0.4.31/ 123
[..]
01347305351a45bb88dab909c56942498e97f5edbe583cf6ab1327138914e315  ./debian/123/usr/lib/R/site-library/RUnit/R/RUnit.rdx
ecde40bdfac5b070acc30a0d5889d9d7f65418844d14312aceff6af5b9d0bf7a  ./debian/123/usr/lib/R/site-library/RUnit/R/RUnit.rdb
182d38ac5adc160eb9edd40d5bd7e27b95b756b8f14cee7d912ba4745ae81bdc  ./debian/123/usr/lib/R/site-library/RUnit/help/RUnit.rdx
f8a9f22acc9f937cb47a92f3979d619e83a791ad734796c2fcd9d0a34e1f11ca  ./debian/123/usr/lib/R/site-library/RUnit/help/RUnit.rdb
5c37672fdc1f325b8a3846f4eafd2624b246ec70ce01d197134fa1b97a9ee849  ./debian/123/usr/lib/R/site-library/RUnit/help/paths.rds
$ ../r-mini-repro-test.sh r-cran-runit-0.4.31/ 1234
[..]
01347305351a45bb88dab909c56942498e97f5edbe583cf6ab1327138914e315  ./debian/1234/usr/lib/R/site-library/RUnit/R/RUnit.rdx
ecde40bdfac5b070acc30a0d5889d9d7f65418844d14312aceff6af5b9d0bf7a  ./debian/1234/usr/lib/R/site-library/RUnit/R/RUnit.rdb
182d38ac5adc160eb9edd40d5bd7e27b95b756b8f14cee7d912ba4745ae81bdc  ./debian/1234/usr/lib/R/site-library/RUnit/help/RUnit.rdx
f8a9f22acc9f937cb47a92f3979d619e83a791ad734796c2fcd9d0a34e1f11ca  ./debian/1234/usr/lib/R/site-library/RUnit/help/RUnit.rdb
5c37672fdc1f325b8a3846f4eafd2624b246ec70ce01d197134fa1b97a9ee849  ./debian/1234/usr/lib/R/site-library/RUnit/help/paths.rds
Works! All finished. :) If yours doesn't, just repeat the above loop; hopefully eventually you'll get there.

30 April 2017

Chris Lamb: Free software activities in April 2017

Here is my monthly update covering what I have been doing in the free software world (previous month):
Reproducible builds

Whilst anyone can inspect the source code of free software for malicious flaws, most software is distributed pre-compiled to end users. The motivation behind the Reproducible Builds effort is to permit verification that no flaws have been introduced either maliciously or accidentally during this compilation process by promising identical results are always generated from a given source, thus allowing multiple third-parties to come to a consensus on whether a build was compromised. I have generously been awarded a grant from the Core Infrastructure Initiative to fund my work in this area. This month I:
I also made the following changes to diffoscope, our recursive and content-aware diff utility used to locate and diagnose reproducibility issues:
  • New features:
    • Add support for comparing Ogg Vorbis files. (0436f9b)
  • Bug fixes:
    • Prevent a traceback when using --new-file with containers. (#861286)
    • Don't crash on invalid archives; print a useful error instead. (#833697).
    • Don't print error output from bzip2 call. (21180c4)
  • Cleanups:
    • Prevent abstraction-level violations by defining visual diff support on Presenter classes. (7b68309)
    • Show Debian packages installed in test output. (c86a9e1)


Debian
Debian LTS

This month I have been paid to work 18 hours on Debian Long Term Support (LTS). In that time I did the following:
  • "Frontdesk" duties, triaging CVEs, etc.
  • Issued DLA 882-1 for the tryton-server general application platform to fix a path suffix injection attack.
  • Issued DLA 883-1 for curl preventing a buffer read overrun vulnerability.
  • Issued DLA 884-1 for collectd (a statistics collection daemon) to close a potential infinite loop vulnerability.
  • Issued DLA 885-1 for the python-django web development framework patching two open redirect & XSS attack issues.
  • Issued DLA 890-1 for ming, a library to create Flash files, closing multiple heap-based buffer overflows.
  • Issued DLA 892-1 and DLA 891-1 for the libnl3/libnl Netlink protocol libraries, fixing integer overflow issues which could have allowed arbitrary code execution.
Uploads
  • redis (4:4.0-rc3-1) New upstream RC release.
  • adminer:
    • 4.3.0-2 Fix debian/watch file.
    • 4.3.1-1 New upstream release.
  • bfs:
    • 1.0-1 Initial release.
    • 1.0-2 Drop fstype tests as they rely on /etc/mtab being available. (#861471)
  • python-django:
    • 1:1.10.7-1 New upstream security release.
    • 1:1.11-1 New upstream stable release to experimental.

I sponsored the following uploads: I also performed the following QA uploads:
  • gtkglext (1.2.0-7) Correct installation location of gdkglext-config.h after "Multi-Archification" in 1.2.0-5. (#860007)
Finally, I made the following non-maintainer uploads (NMUs):
  • python-formencode (1.3.0-2) Don't ship files in /usr/lib/python 2.7,3 /dist-packages/docs. (#860146)
  • django-assets (0.12-2) Patch pytest plugin to check whether we are running in a Django context, otherwise we can break unrelated testsuites. (#859916)
FTP Team

As a Debian FTP assistant I ACCEPTed 155 packages: aiohttp-cors, bear, colorize, erlang-p1-xmpp, fenrir, firejail, fizmo-console, flask-ldapconn, flask-socketio, fontmanager.app, fonts-blankenburg, fortune-zh, fw4spl, fzy, gajim-antispam, gdal, getdns, gfal2, gmime, golang-github-go-macaron-captcha, golang-github-go-macaron-i18n, golang-github-gogits-chardet, golang-github-gopherjs-gopherjs, golang-github-jroimartin-gocui, golang-github-lunny-nodb, golang-github-markbates-goth, golang-github-neowaylabs-wabbit, golang-github-pkg-xattr, golang-github-siddontang-goredis, golang-github-unknwon-cae, golang-github-unknwon-i18n, golang-github-unknwon-paginater, grpc, grr-client-templates, gst-omx, hddemux, highwayhash, icedove, indexed-gzip, jawn, khal, kytos-utils, libbloom, libdrilbo, libhtml-gumbo-perl, libmonospaceif, libpsortb, libundead, llvm-toolchain-4.0, minetest-mod-homedecor, mini-buildd, mrboom, mumps, nnn, node-anymatch, node-asn1.js, node-assert-plus, node-binary-extensions, node-bn.js, node-boom, node-brfs, node-browser-resolve, node-browserify-des, node-browserify-zlib, node-cipher-base, node-console-browserify, node-constants-browserify, node-delegates, node-diffie-hellman, node-errno, node-falafel, node-hash-base, node-hash-test-vectors, node-hash.js, node-hmac-drbg, node-https-browserify, node-jsbn, node-json-loader, node-json-schema, node-loader-runner, node-miller-rabin, node-minimalistic-crypto-utils, node-p-limit, node-prr, node-sha.js, node-sntp, node-static-module, node-tapable, node-tough-cookie, node-tunein, node-umd, open-infrastructure-storage-tools, opensvc, openvas, pgaudit, php-cassandra, protracker, pygame, pypng, python-ase, python-bip32utils, python-ltfatpy, python-pyqrcode, python-rpaths, python-statistics, python-xarray, qtcharts-opensource-src, r-cran-cellranger, r-cran-lexrankr, r-cran-pwt9, r-cran-rematch, r-cran-shinyjs, r-cran-snowballc, ruby-ddplugin, ruby-google-protobuf, ruby-rack-proxy, ruby-rails-assets-underscore, rustc, sbt, sbt-launcher-interface, sbt-serialization, sbt-template-resolver, scopt, seqsero, shim-signed, sniproxy, sortedcollections, starjava-array, starjava-connect, starjava-datanode, starjava-fits, starjava-registry, starjava-table, starjava-task, starjava-topcat, starjava-ttools, starjava-util, starjava-vo, starjava-votable, switcheroo-control, systemd, tilix, tslib, tt-rss-notifier-chrome, u-boot, unittest++, vc, vim-ledger, vis, wesnoth-1.13, wolfssl, wuzz, xandikos, xtensor-python & xwallpaper. I additionally filed 14 RC bugs against packages that had incomplete debian/copyright files against getdns, gfal2, grpc, mrboom, mumps, opensvc, python-ase, sniproxy, starjava-topcat, starjava-ttools, unittest++, wolfssl, xandikos & xtensor-python.

23 April 2017

Andreas Metzler: balance sheet snowboarding season 2016/17

Another year of minimal snow. Again there was early snowfall in the mountains at the start of November, but the snow was gone soon again. There was no snow up to 2000 meters of altitude until about January 3. Christmas week was spent hiking up and taking the lift down. I had my first day on board on January 6 on artificial snow, and the first one on natural snow on January 19. Down where I live (800m), snow was tight the whole winter, never topping 1m. Measuring station Diedamskopf at 1800m above sea-level topped at slightly above 200cm, on April 19. Last boarding day was yesterday (April 22) in Warth with hero-conditions. I had a preopening on the glacier in Pitztal at start of November with Pure Boarding. However due to the long waiting-period between pre-opening and start of season it did not pay off. By the time I rode regularily I had forgotten almost everything I learned at Carving-School. Nevertheless I strong season due to long periods on stable, sunny weather with 30 days on piste (counting the day I went up and barely managed a single blind run in superdense fog). Anyway, here is the balance-sheet:
2005/06 2006/07 2007/08 2008/09 2009/10 2010/11 2011/12 2012/13 2013/14 2014/15 2015/16 2016/17
number of (partial) days251729373030252330241730
Dam ls1010510162310429944
Diedamskopf154242313414191131223
Warth/Schr cken030413100213
total meters of altitude12463474096219936226774202089203918228588203562274706224909138037269819
highscore10247m8321m12108m11272m11888m10976m13076m13885m12848m132781101512245
# of runs309189503551462449516468597530354634

17 April 2017

Sylvain Beucler: Practical basics of reproducible builds 3

On my quest to generate reproducible standalone binaries for GNU FreeDink, I met new friends but currently lie defeated by an unexpected enemy... Episode 1: Episode 2:
First, the random build differences when using -Wl,--no-insert-timestamp were explained.
peanalysis shows random build dates: 
$ reprotest 'i686-w64-mingw32.static-gcc hello.c -I /opt/mxe/usr/i686-w64-mingw32.static/include -I/opt/mxe/usr/i686-w64-mingw32.static/include/SDL2 -L/opt/mxe/usr/i686-w64-mingw32.static/lib -lmingw32 -Dmain=SDL_main -lSDL2main -lSDL2 -lSDL2main -Wl,--no-insert-timestamp -luser32 -lgdi32 -lwinmm -limm32 -lole32 -loleaut32 -lshell32 -lversion -o hello && chmod 700 hello && analysePE.py hello   tee /tmp/hello.log-$(date +%s); sleep 1' 'hello'
$ diff -au /tmp/hello.log-1*
--- /tmp/hello.log-1490950327   2017-03-31 10:52:07.788616930 +0200
+++ /tmp/hello.log-1523203509   2017-03-31 10:52:09.064633539 +0200
@@ -18,7 +18,7 @@
 found PE header (size: 20)
     machine: i386
     number of sections: 17
-    timedatestamp: -1198218512 (Tue Jan 12 05:31:28 1932)
+    timedatestamp: 632430928 (Tue Jan 16 09:15:28 1990)
     pointer to symbol table: 4593152 (0x461600)
     number of symbols: 11581 (0x2d3d)
     size of optional header: 224
@@ -47,7 +47,7 @@
     Win32VersionValue: 0
     size of image (memory): 4640768
     size of headers (offset to first section raw data): 1536
-    checksum (for drivers): 4927867
+    checksum (for drivers): 4922616
     subsystem: 3
         win32 console binary
     DllCharacteristics: 0
Stephen Kitt mentioned 2 simple patches (1 2) fixing uninitialized memory in binutils. These patches fix the variation and were submitted to MXE (pull request).
Next was playing with compiler support for SOURCE_DATE_EPOCH (which e.g. sets __DATE__ macros).
The FreeDink DFArc frontend historically displays a build date in the About box: 
    "Build Date: %s\n", ..., __TDATE__
sadly support is only landing upstream in GCC 7 :/
I had to remove that date.
Now comes the challenging parts. All my tests with reprotest checked. I started writing a reproducible build environment based on Docker (git browse).
At first I could not run reprotest in the container, so I reworked it with SSH support, and reprotest validated determinism.
(I also generate a reproducible .zip archive, more on that later.) So far so good, but were the release identical when running reprotest successively on the different environments?
(reminder: this is a .exe build that is insensitive to varying path, hence consistent in a full reprotest) 
$ sha256sum *.zip
189d0ca5240374896c6ecc6dfcca00905ae60797ab48abce2162fa36568e7cf1  freedink-109.0-bin-buildsh.zip
e182406b4f4d7c3a4d239eee126134ba5c0304bbaa4af3de15fd4f8bda5634a9  freedink-109.0-bin-docker.zip
e182406b4f4d7c3a4d239eee126134ba5c0304bbaa4af3de15fd4f8bda5634a9  freedink-109.0-bin-reprotest-docker.zip
37007f6ee043d9479d8c48ea0a861ae1d79fb234cd05920a25bb3db704828ece  freedink-109.0-bin-reprotest-null.zip
Ouch! Even though both the Docker and my host are running Stretch, there are differences.
For the two host builds (direct and reprotest), there is a subtle but simple difference: HOME.
HOME is invariably non-existant in reprotest, while my normal compilation environment has an existing home (duh!). This caused a subtle bug when cross-compiling with mingw and wine-binfmt: 
  checking whether we are cross compiling... no

  checking whether we are cross compiling... yes
The respective binaries were very different notably due to a different config.h.
This can be fixed by specifying --build in addition to --host when calling ./configure. I suggested reprotest have one of the tests with a valid HOME (#860428).
Now comes the big one, after the fix I still got: 
$ sha256sum *.zip
3545270ef6eaa997640cb62d66dc610a328ce0e7d412f24c8f18fdc7445907fd  freedink-109.0-bin-buildsh.zip
cc50ec1a38598d143650bdff66904438f0f5c1d3e2bea0219b749be2dcd2c3eb  freedink-109.0-bin-docker.zip
3545270ef6eaa997640cb62d66dc610a328ce0e7d412f24c8f18fdc7445907fd  freedink-109.0-bin-reprotest-chroot.zip
cc50ec1a38598d143650bdff66904438f0f5c1d3e2bea0219b749be2dcd2c3eb  freedink-109.0-bin-reprotest-docker.zip
3545270ef6eaa997640cb62d66dc610a328ce0e7d412f24c8f18fdc7445907fd  freedink-109.0-bin-reprotest-null.zip
There is consistency on my host, and consistency within docker, but both are different.
Moreover, all the .o files were identical, so something must have gone wrong when compiling the libs, that is MXE. After many checks it appears that libstdc++.a is different.
Just overwriting it gets me a consistent FreeDink release on all environments.
Still, when rebuilding it (make gcc), libstdc++.a always has the same environment-dependent checksum. 
45f8c5d50a68aa9919ee3602a4e3f5b2bd0333bc8d781d7852b2b6121c8ba27b  /opt/mxe/usr/lib/gcc/i686-w64-mingw32.static/5.4.0/libstdc++.a  # host
6870b84f8e17aec4b5cf23cfe9c2e87e40d9cf59772a92707152361b6ebc1eb4  /opt/mxe/usr/lib/gcc/i686-w64-mingw32.static/5.4.0/libstdc++.a  # docker
The 2 libraries are much different, there's barely any blue in hexcompare. At that time, I realized that the Docker "official" Debian are not really official, as Joey explains.
Could it be that Docker maliciously tampered with the compiler as Ken Thompson warned in 1984?? Well before jumping to conclusion let's mix & match. 
$ sudo env -i /usr/sbin/chroot chroot-docker/
$ exec bash -l
$ cd /opt/mxe
$ touch src/gcc.mk
$ sha256sum /opt/mxe/usr/lib/gcc/i686-w64-mingw32.static/5.4.0/libstdc++.a 
6870b84f8e17aec4b5cf23cfe9c2e87e40d9cf59772a92707152361b6ebc1eb4  /opt/mxe/usr/lib/gcc/i686-w64-mingw32.static/5.4.0/libstdc++.a
$ make gcc
[build]     gcc                    i686-w64-mingw32.static
[done]      gcc                    i686-w64-mingw32.static                                 2709464 KiB    7m2.039s
$ sha256sum /opt/mxe/usr/lib/gcc/i686-w64-mingw32.static/5.4.0/libstdc++.a 
45f8c5d50a68aa9919ee3602a4e3f5b2bd0333bc8d781d7852b2b6121c8ba27b  /opt/mxe/usr/lib/gcc/i686-w64-mingw32.static/5.4.0/libstdc++.a
# consistent with host builds

$ sudo tar -C chroot -c .   docker import - chroot-debootstrap
$ docker run -ti chroot-debootstrap /bin/bash
$ sha256sum /opt/mxe/usr/lib/gcc/i686-w64-mingw32.static/5.4.0/libstdc++.a
45f8c5d50a68aa9919ee3602a4e3f5b2bd0333bc8d781d7852b2b6121c8ba27b  /opt/mxe/usr/lib/gcc/i686-w64-mingw32.static/5.4.0/libstdc++.a
$ touch src/gcc.mk
$ make gcc
[build]     gcc                    i686-w64-mingw32.static
[done]      gcc                    i686-w64-mingw32.static                                 2709412 KiB    7m6.608s
$ sha256sum /opt/mxe/usr/lib/gcc/i686-w64-mingw32.static/5.4.0/libstdc++.a
6870b84f8e17aec4b5cf23cfe9c2e87e40d9cf59772a92707152361b6ebc1eb4  /opt/mxe/usr/lib/gcc/i686-w64-mingw32.static/5.4.0/libstdc++.a
# consistent with docker builds
So, AFAICS when building with: then depending on whether running in a container or not we get a consistent but different libstdc++.a. This kind of issue is not detected with a simple reprotest build, as it only tests variations within a fixed build environment.
This is quite worrisome, I intend to use a container to control my build environment, but I can't guarantee that the container technology will be exactly the same 5 years from now. All my setup is simple and available for inspection at https://git.savannah.gnu.org/cgit/freedink.git/tree/autobuild/freedink-w32-snapshot/. I'd very much welcome enlightenment :)

Ross Gammon: My March 2017 Activities

March was a busy month, so this monthly report is a little late. I worked two weekends, and I was planning my Easter holiday, so there wasn t a lot of spare time. Debian
  • Updated Dominate to the latest version and uploaded to experimental (due to the Debian Stretch release freeze).
  • Uploaded the latest version of abcmidi (also to experimental).
  • Pinged the bugs for reverse dependencies of pygoocanvas and goocanvas with a view to getting them removed from the archive during the Buster cycle.
  • Asked for help on the Ubuntu Studio developers and users mailing lists to test the coming Ubuntu Studio 17.04 release ISO, because I would be away on holiday for most of it.
Ubuntu
  • Worked on ubuntustudio-controls, reverting it back to an earlier revision that Len said was working fine. Unfortunately, when I built and installed it from my ppa, it crashed. Eventually found my mistake with the bzr reversion, fixed it and prepared an upload ready for sponsorship. Submitted a Freeze Exception bug in the hope that the Release Team would accept it even though we had missed the Final Beta.
  • Put a new power supply in an old computer that was kaput, and got it working again. Set up Ubuntu Server 16.04 on it so that I could get a bit more experience with running a server. It won t last very long, because it is a 32 bit machine, and Ubuntu will probably drop support for that architecture eventually. I used two small spare drives to set up RAID 1 & LVM (so that I can add more space to it later). I set up some Samba shares, so that my wife will be able to get at them from her Windows machine. For music streaming, I set up Emby Server. I wold be great to see this packaged for Debian. I uploaded all of my photos and music for Emby to serve around the home (and remotely as well). Set up Obnam to back up the server to an external USB stick (temporarily until I set up something remote). Set LetsEncrypt with the wonderful Certbot program.
  • Did the Release Notes for Ubuntu Studio 17.04 Final Beta. As I was in Brussels for two days, I was not able to do any ISO testing myself.
Other
  • Measured up the new model railway layout and documented it in xtrkcad.
  • Started learning Ansible some more by setting up ssh on all my machines so that I could access them with Ansible and manipulate them using a playbook.
  • Went to the Open Source Days conference just down the road in Copenhagen. Saw some good presentations. Of interest for my previous work in the Debian GIS Team, was a presentation from the Danish Municipalities on how they run projects using Open Source. I noted how their use of Proj 4 and OSGeo. I was also pleased to see a presentation from Ximin Luo on Reproducible Builds, and introduced myself briefly after his talk (during the break).
  • Started looking at creating a Django website to store and publish my One Name Study sources (indexes). Started by creating a library to list some of my recently read Journals. I will eventually need to import all the others I have listed in a cvs spreadsheet that was originally exported from the commercial (Windows only) Custodian software.
Plan status from last month & update for next month Debian For the Debian Stretch release:
  • Keep an eye on the Release Critical bugs list, and see if I can help fix any. In Progress
Generally:
  • Package all the latest upstream versions of my Debian packages, and upload them to Experimental to keep them out of the way of the Stretch release. In Progress
  • Begin working again on all the new stuff I want packaged in Debian.
Ubuntu
  • Start working on an Ubuntu Studio package tracker website so that we can keep an eye on the status of the packages we are interested in. Started
  • Start testing & bug triaging Ubuntu Studio packages. In progress
  • Test Len s work on ubuntustudio-controls Done
  • Do the Ubuntu Studio Zesty 17.04 Final Beta release. Done
  • Sort out the Blueprints for the coming Ubuntu Studio 17.10 release cycle.
Other
  • Give JMRI a good try out and look at what it would take to package it. In progress
  • Also look at OpenPLC for simulating the relay logic of real railway interlockings (i.e. a little bit of the day job at home involving free software fun!). In progress

15 April 2017

Dirk Eddelbuettel: Rcpp now used by 1000 CRAN packages

800 Rcpp packages Moments ago Rcpp passed a big milestone as there are now 1000 packages on CRAN depending on it (as measured by Depends, Imports and LinkingTo, but excluding Suggests). The graph is on the left depicts the growth of Rcpp usage over time. One easy way to compute such reverse dependency counts is the tools::dependsOnPkgs() function that was just mentioned in yesterday's R^4 blog post. Another way is to use the reverse_dependencies_with_maintainers() function from this helper scripts file on CRAN. Lastly, devtools has a function revdep() but it has the wrong default parameters as it includes Suggests: which you'd have to override to get the count I use here (it currently gets 1012 in this wider measure). Rcpp cleared 300 packages in November 2014. It passed 400 packages in June 2015 (when I only tweeted about it), 500 packages in late October 2015, 600 packages last March, 700 packages last July, 800 packages last October and 900 packages early January. The chart extends to the very beginning via manually compiled data from CRANberries and checked with crandb. The next part uses manually saved entries. The core (and by far largest) part of the data set was generated semi-automatically via a short script appending updates to a small file-based backend. A list of packages using Rcpp is kept on this page. Also displayed in the graph is the relative proportion of CRAN packages using Rcpp. The four per-cent hurdle was cleared just before useR! 2014 where I showed a similar graph (as two distinct graphs) in my invited talk. We passed five percent in December of 2014, six percent July of 2015, seven percent just before Christmas 2015, eight percent last summer, and nine percent mid-December 2016. Ten percent is next; we may get there during the summer. 1000 user packages is a really large number. This puts a whole lot of responsibility on us in the Rcpp team as we continue to keep Rcpp as performant and reliable as it has been. And with that a very big Thank You! to all users and contributors of Rcpp for help, suggestions, bug reports, documentation or, of course, code.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

14 April 2017

Laura Arjona Reina: Underestimating Debian

I had two issues in the last days that lead me a bit into panic until they got solved. In both cases the issue was external to Debian but I first thought that the problem was in Debian. I m not sure why I had those thoughts, I should be more confident in myself, this awesome operating system, and the community around it! The good thing is that I ll be more confident from now on, and I ve learned that hurry is not a good friend, and I should face my computer problems (and everything in life, probably) with a bit more patience (and backups). Issue 1: Corrupt ext partition in a laptop I have a laptop at home with dual boot Windows 7 + Debian 9 (Stretch). I rarely boot the Windows partition. When I do, I do whatever I need to do/test there, then install updates, and then shutdown the laptop or reboot in Debian to feel happy again when using computers. Some months ago I noticed that booting in Debian was not possible and I was left in an initramfs console that was suggesting to e2fsck /dev/sda6 (my Debian partition). Then I ran e2fsck, say a to fix all the issues found, and the system was booting properly. This issue was a bit scary-looking because of the e2fsck output making screen show random numbers and scrolling quickly for 1 or 2 minutes, until all the inodes or blocks or whatever were fixed. I thought about the disk being faulty, and ran badblocks, but faced the former boot issue again some time after, and then decided to change the disk (then I took the opportunity to make backups, and install a fresh Debian 9 Stretch in the laptop, instead of the Debian 8 stable that was running). The experience with Stretch has been great since then, but some days ago I faced the boot issue again. Then I realised that maybe the issue was appearing when I booted Debian right after using Windows (and this was why it was appearing not very often in my timeline ). Then I payed more attention to the message that I was receiving in the console 
Superblock checksum does not match superblock while trying to open /dev/sda6
 /dev/sda6:
 The superblock could not be read or does not describe a valid ext2/ext3/ext4
 filesystem. If the device is valid and it really contains an ext2/ext3/ext4
 filesystem (and not swap or ufs or something else), then the superblock
 is corrupt, and you might try running e2fsck with an alternate superblock:
 e2fsck -b 8193
 or
 e2fsck -b 32768
and searched about it, and also asked about it to my friends in the redeslibres XMPP chat room I found this question in the AskUbuntu forum that was exactly my issue (I had ext2fsd installed in Windows). My friends in the XMPP room friendly yelled booo! at me for letting Windows touch my ext partitions (I apologised, it will never happen again!). I now consistently could reproduce the issue (boot Windows, then boot Debian, bang!: initramfs console, e2fsck, reboot Debian, no problem, boot Windows, boot Debian, again the problem, etc). I uninstalled the ext2fsd program and tried to reproduce the issue, and I couldn t reproduce it. So happy end. Issue 2: Accessing Android internal memory to backup files The other issue was with my tablet running Android 4.0.4. It was facing a charge issue, and I wanted to backup the files there before sending it to repair. I connected the tablet with USB to my laptop, and enabled USB debugging. The laptop recognized a MZ604 camera connected, but Dolphin (the file browser of my KDE Plasma desktop) could not show the files. I looked at the settings in the tablet to try to find the setting that allowed me to switch between camera/MTP when connecting with USB, but couldn t find it. I guessed that the tablet was correctly configured because I recall having made a backup some months ago, with no hassle (in Debian 8). I checked that my Debian (9) had installed the needed packages: 
 ii kio-mtp 0.75+git20140304-2 amd64 access to MTP devices for applications using the KDE Platform
 ii libmtp-common 1.1.12-1 all Media Transfer Protocol (MTP) common files
 ii libmtp-runtime 1.1.12-1+b1 amd64 Media Transfer Protocol (MTP) runtime tools
 ii libmtp9:amd64 1.1.12-1+b1 amd64 Media Transfer Protocol (MTP) library
So I had no idea about what was going on. Then I suspected some problem in my Debian (maybe I was needing some driver for the Motorola tablet?) and booted Windows 7 to see what happened there. Windows detected a MZ604 device too, but couldn t access the files either (when clicking in the device, no folders were shown). I began to search the internet to see if there were some Motorola drivers out there, and then found the clue to enable the correct settings in the Android device: you need to go to Settings > Storage, and then press the 3-dots button that makes the Menu function, and then appears USB computer connection and there, you can enable Camera or MTP. Very hidden setting! I enabled MTP, and then I could see the folders and files in my Windows system (without need of installing any additional driver), and make my backup. And of course after rebooting and trying in Debian, it worked too. Some outcomes/conclusions Comments? You can comment on this post using this pump.io thread.
Filed under: My experiences and opinion Tagged: Android, Debian, English, KDE, Libre software for Windows

13 April 2017

Antoine Beaupr : New approaches to network fast paths

With the speed of network hardware now reaching 100 Gbps and distributed denial-of-service (DDoS) attacks going in the Tbps range, Linux kernel developers are scrambling to optimize key network paths in the kernel to keep up. Many efforts are actually geared toward getting traffic out of the costly Linux TCP stack. We have already covered the XDP (eXpress Data Path) patch set, but two new ideas surfaced during the Netconf and Netdev conferences held in Toronto and Montreal in early April 2017. One is a patch set called af_packet, which aims at extracting raw packets from the kernel as fast as possible; the other is the idea of implementing in-kernel layer-7 proxying. There are also user-space network stacks like Netmap, DPDK, or Snabb (which we previously covered). This article aims at clarifying what all those components do and to provide a short status update for the tools we have already covered. We will focus on in-kernel solutions for now. Indeed, user-space tools have a fundamental limitation: if they need to re-inject packets onto the network, they must again pay the expensive cost of crossing the kernel barrier. User-space performance is effectively bounded by that fundamental design. So we'll focus on kernel solutions here. We will start from the lowest part of the stack, the af_packet patch set, and work our way up the stack all the way up to layer-7 and in-kernel proxying.

af_packet v4 John Fastabend presented a new version of a patch set that was first published in January regarding the af_packet protocol family, which is currently used by tcpdump to extract packets from network interfaces. The goal of this change is to allow zero-copy transfers between user-space applications and the NIC (network interface card) transmit and receive ring buffers. Such optimizations are useful for telecommunications companies, which may use it for deep packet inspection or running exotic protocols in user space. Another use case is running a high-performance intrusion detection system that needs to watch large traffic streams in realtime to catch certain types of attacks. Fastabend presented his work during the Netdev network-performance workshop, but also brought the patch set up for discussion during Netconf. There, he said he could achieve line-rate extraction (and injection) of packets, with packet rates as high as 30Mpps. This performance gain is possible because user-space pages are directly DMA-mapped to the NIC, which is also a security concern. The other downside of this approach is that a complete pair of ring buffers needs to be dedicated for this purpose; whereas before packets were copied to user space, now they are memory-mapped, so the user-space side needs to process those packets quickly otherwise they are simply dropped. Furthermore, it's an "all or nothing" approach; while NIC-level classifiers could be used to steer part of the traffic to a specific queue, once traffic hits that queue, it is only accessible through the af_packet interface and not the rest of the regular stack. If done correctly, however, this could actually improve the way user-space stacks access those packets, providing projects like DPDK a safer way to share pages with the NIC, because it is well defined and kernel-controlled. According to Jesper Dangaard Brouer (during review of this article):
This proposal will be a safer way to share raw packet data between user space and kernel space than what DPDK is doing, [by providing] a cleaner separation as we keep driver code in the kernel where it belongs.
During the Netdev network-performance workshop, Fastabend asked if there was a better data structure to use for such a purpose. The goal here is to provide a consistent interface to user space regardless of the driver or hardware used to extract packets from the wire. af_packet currently defines its own packet format that abstracts away the NIC-specific details, but there are other possible formats. For example, someone in the audience proposed the virtio packet format. Alexei Starovoitov rejected this idea because af_packet is a kernel-specific facility while virtio has its own separate specification with its own requirements. The next step for af_packet is the posting of the new "v4" patch set, although Miller warned that this wouldn't get merged until proper XDP support lands in the Intel drivers. The concern, of course, is that the kernel would have multiple incomplete bypass solutions available at once. Hopefully, Fastabend will present the (by then) merged patch set at the next Netdev conference in November.

XDP updates Higher up in the networking stack sits XDP. The af_packet feature differs from XDP in that it does not perform any sort of analysis or mangling of packets; its objective is purely to get the data into and out of the kernel as fast as possible, completely bypassing the regular kernel networking stack. XDP also sits before the networking stack except that, according to Brouer, it is "focused on cooperating with the existing network stack infrastructure, and on use-cases where the packet doesn't necessarily need to leave kernel space (like routing and bridging, or skipping complex code-paths)." XDP has evolved quite a bit since we last covered it in LWN. It seems that most of the controversy surrounding the introduction of XDP in the Linux kernel has died down in public discussions, under the leadership of David Miller, who heralded XDP as the right solution for a long-term architecture in the kernel. He presented XDP as a fast, flexible, and safe solution. Indeed, one of the controversies surrounding XDP was the question of the inherent security challenges with introducing user-provided programs directly into the Linux kernel to mangle packets at such a low level. Miller argued that whatever protections are expected for user-space programs also apply to XDP programs, comparing the virtual memory protections to the eBPF (extended BPF) verifier applied to XDP programs. Those programs are actually eBPF that have an interesting set of restrictions:
  • they have a limited size
  • they cannot jump backward (and thus cannot loop), so they execute in predictable time
  • they do only static allocation, so they are also limited in memory
XDP is not a one-size-fits-all solution: netfilter, the TC traffic shaper, and other normal Linux utilities still have their place. There is, however, a clear use case for a solution like XDP in the kernel. For example, Facebook and Cloudflare have both started testing XDP and, in Facebook's case, deploying XDP in production. Martin Kafai Lau, from Facebook, presented the tool set the company is using to construct a DDoS-resilience solution and a level-4 load balancer (L4LB), which got a ten-times performance improvement over the previous IPVS-based solution. Facebook rolled out its own user-space solution called "Droplet" to detect hostile traffic and deploy blocking rules in the form of eBPF programs loaded in XDP. Lau demonstrated the way Facebook deploys a three-part chained eBPF program: the first part allows debugging and dumping of packets, the second is Droplet itself, which drops undesirable traffic, and the last segment is the load balancer, which mangles the packets to tweak their destination according to internal rules. Droplet can drop DDoS attacks at line rate while keeping the architecture flexible, which were two key design requirements. Gilberto Bertin, from Cloudflare, presented a similar approach: Cloudflare has a tool that processes sFlow data generated from iptables in order to generate cBPF (classic BPF) mitigation rules that are then deployed on edge routers. Those rules are created with a tool called bpfgen, part of Cloudflare's BSD-licensed bpftools suite. For example, it could create a cBPF bytecode blob that would match DNS queries to any example.com domain with something like: 
    bpfgen dns *.example.com
Originally, Cloudflare would deploy those rules to plain iptables firewalls with the xt_bpf module, but this led to performance issues. It then deployed a proprietary user-space solution based on Solarflare hardware, but this has the performance limitations of user-space applications getting packets back onto the wire involves the cost of re-injecting packets back into the kernel. This is why Cloudflare is experimenting with XDP, which was partly developed in response to the company's problems, to deploy those BPF programs. A concern that Bertin identified was the lack of visibility into dropped packets. Cloudflare currently samples some of the dropped traffic to analyze attacks; this is not currently possible with XDP unless you pass the packets down the stack, which is expensive. Miller agreed that the lack of monitoring for XDP programs is a large issue that needs to be resolved, and suggested creating a way to mark packets for extraction to allow analysis. Cloudflare is currently in a testing phase with XDP and it is unclear if its whole XDP tool chain will be publicly available. While those two companies are starting to use XDP as-is, there is more work needed to complete the XDP project. As mentioned above and in our previous coverage, massive statistics extraction is still limited in the Linux kernel and introspection is difficult. Furthermore, while the existing actions (XDP_DROP and XDP_TX, see the documentation for more information) are well implemented and used, another action may be introduced, called XDP_REDIRECT, which would allow redirecting packets to different network interfaces. Such an action could also be used to accelerate bridges as packets could be "switched" based on the MAC address table. XDP also requires network driver support, which is currently limited. For example, the Intel drivers still do not support XDP, although that should come pretty soon. Miller, in his Netdev keynote, focused on XDP and presented it as the standard solution that is safe, fast, and usable. He identified the next steps of XDP development to be the addition of debugging mechanisms, better sampling tools for statistics and analysis, and user-space consistency. Miller foresees a future for XDP similar to the popularization of the Arduino chips: a simple set of tools that anyone, not just developers, can use. He gave the example of an Arduino tutorial that he followed where he could just look up a part number and get easy-to-use instructions on how to program it. Similar components should be available for XDP. For this purpose, the conference saw the creation of a new mailing list called xdp-newbies where people can learn how to create XDP build environments and how to write XDP programs.

In-kernel layer-7 proxying The third approach that struck me as innovative is the idea of doing layer-7 (application) proxying directly in the kernel. This comes from the idea that, traditionally, we build firewalls to segregate traffic and apply controls, but as most services move to HTTP, those policies become ineffective. Thomas Graf, presented this idea during Netconf using a Star Wars allegory: what if the Death Star were a server with an API? You would have endpoints like /dock or /comms that would allow you to dock a ship or communicate with the Death Star. Those API endpoints should obviously be public, but then there is this /exhaust-port endpoint that should never be publicly available. In order for a firewall to protect such a system, it must be able to inspect traffic at a higher level than the traditional address-port pairs. Graf presented a design where the kernel would create an in-kernel socket that would negotiate TCP connections on behalf of user space and then be able to apply arbitrary eBPF rules in the kernel. Graf's design of in-kernel proxying In this scenario, instead of doing the traditional transfer from Netfilter's TPROXY to user space, the kernel directly decapsulates the HTTP traffic and passes it to BPF rules that can make decisions without doing expensive context switches or memory copies in the case of simply wanting to refuse traffic (e.g. issue an HTTP 403 error). This, of course, requires the inclusion of kTLS to process HTTPS connections. HTTP2 support may also prove problematic, as it multiplexes connections and is harder to decapsulate. This design was described as a "pure pre-accept() hook". Starovoitov also compared the design to the kernel connection multiplexer (KCM). Tom Herbert, KCM's author, agreed that it could be extended to support this, but would require some extensions in user space to provide an interface between regular socket-based applications and the KCM layer. In any case, if the application does TLS (and lots of them do), kTLS gets tricky because it breaks the end-to-end nature of TLS, in effect becoming a man in the middle between the client and the application. Eric Dumazet argued that HA-Proxy already does things like this: it uses splice() to avoid copying too much data around, but it still does a context switch to hand over processing to user space, something that could be fixed in the general case. Another similar project that was presented at Netdev is the Tempesta firewall and reverse-proxy. The speaker, Alex Krizhanovsky, explained the Tempesta developers have taken one person month to port the mbed TLS stack to the Linux kernel to allow an in-kernel TLS handshake. Tempesta also implements rate limiting, cookies, and JavaScript challenges to mitigate DDoS attacks. The argument behind the project is that "it's easier to move TLS to the kernel than it is to move the TCP/IP stack to user space". Graf explained that he is familiar with Krizhanovsky's work and he is hoping to collaborate. In effect, the design Graf is working on would serve as a foundation for Krizhanovsky's in-kernel HTTP server (kHTTP). In a private email, Graf explained that:
The main differences in the implementation are currently that we foresee to use BPF for protocol parsing to avoid having to implement every single application protocol natively in the kernel. Tempesta likely sees this less of an issue as they are probably only targeting HTTP/1.1 and HTTP/2 and to some [extent] JavaScript.
Neither project is really ready for production yet. There didn't seem to be any significant pushback from key network developers against the idea, which surprised some people, so it is likely we will see more and more layer-7 intelligence move into the kernel sooner rather than later.

Conclusion All of this work aims at replacing a rag-tag bunch of proprietary solutions that recently came up to bypass the Linux kernel TCP/IP stack and improve performance for firewalls, proxies, and other key edge network elements. The idea is that, unless the kernel improves its performance, or at least provides a way to bypass its more complex code paths, people will work around it. With this set of solutions in place, engineers will now be able to use standard APIs to hook high-performance systems into the Linux kernel.
The author would like to thank the Netdev and Netconf organizers for travel assistance, Thomas Graf for a review of the in-kernel proxying section of this article, and Jesper Dangaard Brouer for review of the af_packet and XDP sections. Note: this article first appeared in the Linux Weekly News.

10 April 2017

Daniel Pocock: If Alan Turing was born today, would he be a Muslim?

Alan Turing's name and his work are well known to anybody with a theoretical grounding in computer science. Turing developed his theories well before anybody invented file sharing, overclocking or mass surveillance. In fact, Turing was largely working in the absence of any computers at all: the transistor was only invented in 1947 and the microchip, the critical innovation that has made computing both affordable and portable, only came in 1960, four years after Turing's death. To this day, the Turing Test remains a well known challenge in the field of Artificial Intelligence. The most prestigious prize in computing, the A.M. Turing Award from the ACM, equivalent to the Nobel Prize in other fields of endeavour, is named in Turing's honour. (This year's award is another British scientist, Sir Tim Berners-Lee, inventor of the World Wide Web).
Potentially far more people know of Alan Turing for his groundbreaking work at Bletchley Park and the impact it had on cracking the Nazi's Enigma machines during World War 2, giving the allies an advantage against Hitler. While in his lifetime, Turing exposed the secret communications of the Nazis, in his death, he exposed something manifestly repugnant about his own society. Turing's challenges with his sexuality (or Britain's challenge with it) are just as well documented as his greatest scientific achievements. The 2014 movie The Imitation Game tells Turing's story, bringing together the themes from his professional and personal life. Had Turing chosen to flee British persecution by going abroad, he would be a refugee in the same sense as any person who crossed the seas to reach Europe today to avoid persecution elsewhere. Please prove me wrong In March, I blogged about the problem of racism that plagues Britain today. While some may have felt the tone of the blog was quite strong, I was in no way pleased to find my position affirmed by the events that occurred in the two days after the blog appeared. Two days and two more human beings (both immigrants and both refugees) subjected to abhorrent and unnecessary acts of abuse in Great Britain. Both cases appear to be fuelled directly by the evil that has been oozing out of number 10 Downing Street since they decided to have a referendum on "Brexit". What stands out about these latest crimes is not that they occurred (this type of thing has been going on for months now) but certain contrasts between their circumstances and to a lesser extent, the fact they occurred immediately after Theresa May formalized Britain's departure from the EU. One of the victims was almost beaten to death by a street gang, while the other was abused by men wearing uniforms. One was only a child, while the other is a mature adult who has been in the UK almost three decades, completely assimilated into British life, working and paying taxes. Both were doing nothing out of the ordinary at the time the abuse occurred: one had engaged in a conversation at a bus stop, the other was on a routine visit to a Government office. There is no evidence that either of them had done anything to provoke or invite the abhorrent treatment meted out to them by the followers of Theresa May and Nigel Farage. The first victim, on 30 March, was Stojan Jankovic, a refugee from Yugoslavia who has been in the UK for 26 years. He had a routine meeting at an immigration department office where he was ambushed, thrown in the back of a van and sent to rot in a prison cell by Theresa May's gestapo. On Friday, 31 March, it was Reker Ahmed, a 17 year old Kurdish-Iranian beaten to the brink of death by a crowd in south London. One of the more remarkable facts to emerge about these two cases is that while Stojan Jankovic was basically locked up for no reason at all, the street thugs who the police apprehended for the assault on Ahmed were kept in a cell for less than 48 hours and released again on bail. While the harmless and innocent Jankovic was eventually released after a massive public outcry, he spent more time locked up than that gang of violent criminals who beat Reker Ahmed. In other words, Theresa May and Nigel Farage's Britain has more concern for the liberty of violent criminals than somebody like Jankovic who has been working and paying taxes in the UK since before any of those street thugs were born. A deeper insight into Turing's fate With gay marriage having been legal in the UK for a number of years now, the rainbow flag flying at the Tate and Sir Elton John achieving a knighthood, it becomes difficult for people to relate to the world in which Turing and many other victims were collectively classified by their sexuality, systematically persecuted by the state and ultimately died far sooner than they should have. (Turing was only 41 when he died). In fact, the cruel and brutal forces that ripped Turing apart (and countless other victims too) haven't dissipated at all, they have simply shifted their target. The slanderous comments insinuating that immigrants "steal" jobs or that Islam is about terrorism are eerily reminiscent of suggestions that gay men abduct young boys or work as Soviet spies. None of these lies has any basis in fact, but repeat them often enough in certain types of newspaper and these ideas spread like weeds. In an ironic twist, Turing's groundbreaking work at Bletchley Park was founded on the contributions of Polish mathematicians, their own country having been the first casualty to Hitler, they were also both immigrants and refugees in Britain. Today, under the Theresa May/Nigel Farage leadership, Polish citizens have been subjected to regular vilification by the media and some have even been killed in the street. It is said that a picture is worth a thousand words. When you compare these two pieces of propaganda: a 1963 article in the Sunday Mirror advising people "How to spot a possible homo" and a UK Government billboard encouraging people to be on the lookout for people who look different, could you imagine the same type of small-minded and power-hungry tyrants crafting them, singling out a minority so as to keep the public's attention in the wrong place?
Many people have noticed that these latest UK Government posters portray foreigners, Muslims and basically anybody who is not white using a range of characteristics found in anti-semetic propaganda from the Third Reich: Do the people who create such propaganda appear to have any concern whatsoever for the people they hurt? How would Alan Turing have felt when he encountered propaganda like that from the Sunday Mirror? Do posters like these encourage us to judge people by their gifts in science, the arts or sporting prowess or do they encourage us to lump them all together based on their physical appearance? It is a basic expectation of scientific methodology that when you repeat the same experiment, you should get the same result. What type of experiment are Theresa May and Nigel Farage conducting and what type of result would you expect? Playing ping-pong with children If anybody has any doubt that this evil comes from the top, take a moment to contemplate the 3,000 children who were baited with the promise of resettlement from the Calais "jungle" camp into the UK under the Dubs amendment. When French authorities closed the "jungle" in 2016, the children were lured out of the camp and left with nowhere to go as Theresa May and French authorities played ping-pong with them. Given that the UK parliament had already agreed they should be accepted, was there any reason for Theresa May to dig her heels in and make these children suffer? Or was she just trying to prove her credentials as somebody who can bastardize migrants just the way Nigel Farage would do it? How do British politicians really view migrants? Parliamentarian Keith Vaz, former chair of the Home Affairs Select Committee (responsible for security, crime, prostitution and similar things) was exposed with young men from eastern Europe, encouraging them to take drugs before he ordered them "Take your shirt off. I'm going to attack you.". How many British MP's see foreigners this way? Next time you are groped at an airport security checkpoint, remember it was people like Keith Vaz and his committee who oversee those abuses, writing among other things that "The wider introduction of full-body scanners is a welcome development". No need to "take your shirt off" when these machines can look through it as easily as they can look through your children's underwear. According to the World Health Organization, HIV/AIDS kills as many people as the September 11 attacks every single day. Keith Vaz apparently had no concern for the possibility he might spread this disease any further: the media reported he doesn't use any protection in his extra-marital relationships. While Britain's new management continue to round up foreigners like Stojan Jankovic who have done nothing wrong, they chose not to prosecute Keith Vaz for his antics with drugs and prostitution. Who is Britain's next Alan Turing? Britain's next Alan Turing may not be a homosexual. He or she may have been a child turned away by Theresa May's spat with the French at Calais, a migrant bundled into a deportation van by the gestapo (who are just following orders) or perhaps somebody of Muslim appearance who is set upon by thugs in the street who have been energized by Nigel Farage. If you still have any uncertainty about what Brexit really means, this is it. A country that denies itself the opportunity to be great by subjecting itself to be ruled under the "divide and conquer" mantra of the colonial era. Throughout the centuries, Britain has produced some of the most brilliant scientists of their time. Newton, Darwin and Hawking are just some of those who are even more prominent than Turing, household names around the world. One can only wonder what the history books will have to say about Theresa May and Nigel Farage however. Next time you see a British policeman accosting a Muslim, whether it is at an airport, in a shopping centre, keeping Manchester United souvenirs or simply taking a photograph, spare a thought for Alan Turing and the era when homosexuals were their target of choice.

1 April 2017

Antoine Beaupr : My free software activities, February and March 2017

Looking into self-financing Before I begin, I should mention that I started tracking my time working on free software more systematically. I spend a lot of time on the computer, as regular readers of this blog might remember so I wanted to know exactly how much time was paid vs free work. I was already using org-mode's time clock system to keep track of my work hours, so I just extended this to my regular free software contributions, which also helps in writing those reports. It turns out that over 60% of my computer time is spent working on free software. That's huge! I was expecting something more along the range of 20 to 40% of my time. So I started thinking about ways of financing this work. I created a Patreon page but I'm hesitant into launching such a campaign: the only thing worse than "no patreon page" is "a patreon page with failed goals and no one financing it". So before starting such an effort, I'd like to get a feeling of what other people's experience with it are. I know that joeyh is close to achieving his goals, but I can't compare with the guy that invented git-annex or debhelper, so I'm concerned I wouldn't be able to raise the same level of funding. So any advice you have, feel free to contact me in private or in the comments. If you would be ready to fund my work, I'd love to know about it, obviously, but I guess I wouldn't get real numbers until I actually open up such a page... Now, onto the regular report.

Wallabako I spent a good chunk of time completing most of the things I had in mind for Wallabako, which I mentioned quickly in the previous report. Wallabako is now much easier to installed, with clearer instructions, an easier to use configuration file, more reliable synchronization and read status propagation. As usual the Wallabako README file has all the details. I've also looked at better integration with Koreader, the free software e-reader that forms the basis of the okreader free software distribution which has been able to port Debian to the Kobo e-readers, a project I am really excited about. This project has the potential of supporting Kobo readers beyond the lifetime that upstream grants it and removes a lot of proprietary software and spyware that ships with the Kobo readers. So I have made a few contributions to okreader and also on koreader, the ebook reader okreader is based on.

Stressant I rewrote stressant, my simple burn-in and stress-testing tool. After struggling in turn with Debirf, live-build, vmdebootstrap and even FAI, I just figured maybe it wasn't the best idea to try and reinvent that particular wheel: instead of reinventing how to build yet another Debian system build tool, maybe I should just reuse what's already there. It turns out there's a well known, succesful and fairly complete recovery system called Grml. It is a Debian Derivative, so all I needed to do was to stop procrastinating and actually write the actual stressant tool instead of just creating a distribution with a bunch of random tools shipped in. This allowed me to focus on which tools were the best to stress test different components. This selection ended up being: fio can also be used to overwrite disk drives with the proper options (--overwrite and --size=100%), although grml also ships with nwipe for wiping old spinning disks and hdparm to do a secure erase of SSD disks (whatever that's worth). Stressant still needs to be shipped with grml for this transition to be complete. In the meantime, I was able to configure the excellent public Gitlab CI service to provide ISO images with Stressant built-in as a stopgap measure. I also need to figure out a way to automate starting stressant from a boot menu to automate deployments on a larger scale, although because I have little need for the feature at this moment in time, this will likely wait for a sponsor to show up for this to be implemented. Still, stressant has useful features like the capability of sending logs by email using a fresh new implementation of the Python SMTPHandler (BufferedSMTPHandler) which waits for logging to complete before sending a single email. Another interesting piece of code in there is the NegateAction argparse handler that enables the use of "toggle flags" (e.g. --flag / --no-flag). I'm so happy with the code that I figure I could just share it here directly: 
class NegateAction(argparse.Action):
    '''add a toggle flag to argparse

    this is similar to 'store_true' or 'store_false', but allows
    arguments prefixed with --no to disable the default. the default
    is set depending on the first argument - if it starts with the
    negative form (define by default as '--no'), the default is False,
    otherwise True.
    '''
    negative = '--no'
    def __init__(self, option_strings, *args, **kwargs):
        '''set default depending on the first argument'''
        default = not option_strings[0].startswith(self.negative)
        super(NegateAction, self).__init__(option_strings, *args,
                                           default=default, nargs=0, **kwargs)
    def __call__(self, parser, ns, values, option):
        '''set the truth value depending on whether
        it starts with the negative form'''
        setattr(ns, self.dest, not option.startswith(self.negative))
Short and sweet. I wonder why stuff like this is not in the standard library yet - maybe just because no one bothered yet? It'd be great to get feedback of more experienced Pythonistas on this one. I hope that my work on Stressant is complete. I get zero funding for this work, and have little use for it myself: I manage only a few machines and such a tool really shines when you regularly put new hardware online, which is (fortunately?) not my case anymore. I'd be happy, of course, to accompany organisations and people that wish to further develop and use such a tool. A short demo of stressant as well as detailed description of how it works is of course available in its README file.

Standard third party repositories After looking at improvements for the grml repository instructions, I realized there was no real "best practices" document on how to configure an Apt repository. Sure, there are tools like reprepro and others, but those hardly qualify as policy: they are very flexible and there are lots of ways to create insecure repositories or curl sh style instructions, which we of course generally want to avoid. While the larger problem of Unstrusted Debian packages remain generally unsolved (e.g. when you install any .deb file, it can get root on your system), it seemed to me one critical part of this problem was how to add a random third-party repository to your machine while limiting, as much as possible, what possible attackers could do with such a repository. In other words, to solve the more general problem of insecure .deb files, we also need to solve the distribution problem, otherwise fixing the .deb files themselves will be useless. This lead to the creation of standardized repository instructions that define:
  1. how to distribute the repository's public signing key (ie. over HTTPS)
  2. how to name suites and components (e.g. use stable and main unless you have a good reason, and explain yourself)
  3. recommend a healthy does of apt preferences pinning
  4. how to distribute keys (e.g. with a derive-archive-keyring package)
I've seen so many third party repositories get this wrong. For example, a lot of repositories recommend this type of command to intialize the OpenPGP trust path: 
curl http://example.com/key.asc   apt-key add -
This has the following problems:
  • the key is transfered in plaintext and can easily be manipulated by an active attacker (e.g. a router on your path to the server or a neighbor in a Wifi cafe)
  • the key is added to the main trust root, which allows the key to authentify as the real Debian archive, therefore giving it all rights over all packages
  • since it's part of the global archive, it's difficult for a package to remove/add the key when a key rollover is necessary (and repositories generally don't provide a deriv-archive-keyring to do that process anyways)
An example of this are the Docker install instructions that, at least, manage to do this over HTTPS. Some other repositories don't even bother teaching people about the proper way of adding those keys. We settled for: 
wget -O /usr/share/keyrings/deriv-archive-keyring.gpg https://deriv.example.net/debian/deriv-archive-keyring.gpg
That location was explicitly chosen to be out of the main trust directory, so that it needs to be explicitly added to the sources.list as well: 
deb [signed-by=/usr/share/keyrings/deriv-archive-keyring.gpg] https://deriv.example.net/debian/ stable main
Similarly, we highly recommend users setup "apt pinning" to restrict what a given repository can do. Since pinning is so confusing, most people don't actually bother even configuring it and I have yet to see a single repo advise its users to configure those preferences, which are essential to limit what a repository can do. To keep configuration simple, we recommend this: 
Package: *
Pin: origin deriv.example.net
Pin-Priority: 100
Obviously, for a single-package repository, the actual package name should be listed, e.g.: 
Package: foo
Pin: origin deriv.example.net
Pin-Priority: 100
And the priority should probably be set to 1 unless you want to allow automatic upgrades. It is my hope that this design will get more traction in the years to come and become a de-facto standard that will be a key part in safely adding third party repositories. There is obviously much more work to be done to improve security when installing untrusted .deb files, and I encourage Debian developers to consider contributing to the UntrustedDebs discussions and particularly to the Teams/Dpkg/Spec/DeclarativePackaging work.

Signal R&D I spent a significant amount of time this month struggling with the Signal project on my phone. I'm still ambivalent on Signal: it's a centralized designed, too dependent on phone numbers, but I must admit they get a lot of things right and it's the only free-software platform that allows for easy-to-use, multi-platform videoconferencing that my family can use. I've been following Signal for a while: up until now, I had been using the LibreSignal rebuild of the official client, as it is distributed on a F-Droid repository. Because I try to avoid Google (proprietary) software on my phone, it's basically the only way I could even install Signal. Unfortunately, the repository is out of date and introduces another point of trust in the distribution model: now you not only need to trust the Signal authors to do the right thing, you also need to trust that F-Droid repo not to inject nasty code on your phone. I've therefore started a discussion about how Signal could be distributed outside of the Google Play Store. I'd like to think it's one of the things that led the Signal people to distribute an official copy of Signal outside of the playstore. After much struggling, I was able to upgrade to this official client and will be able to upgrade easily by just downloading the APK. (Do note that I ended up reinstalling and re-registering Signal, which unfortunately changed my secret keys.) I do hope Signal enters F-Droid one day, but it could take a while because it still doesn't work without Google services and barely works with MicroG, the free software alternative to the Google services clients. Moxie also set a list of requirements like crash reporting and statistics that need to be implemented on F-Droid's side before he agrees to the deployment, so this could take a while. I've also participated in the, ahem, discussion on the JWZ blog regarding a supposed vulnerability in Signal where it would leak previously unknown phone numbers to third parties. I reviewed the way the phone number is uploaded and, while it's possible to create a rainbow table of phone numbers (which are hashed with a truncated SHA-1 checksum), I couldn't verify the claims of other participants in the thread. For me, Signal still does the right thing with contacts, although I do question the way "read status" notifications get transmitted, but that belong in another bug report / blog post.

Debian Long Term Support (LTS) It's been more than a year working on Debian LTS, started by Raphael Hertzog at Freexian. I didn't work much in February so I had a lot of hours to catchup with, and was unfortunately unable to do so, partly because I was busy with other projects, and partly because my colleagues are doing a great job at resolving the most important issues. So one my concerns this month was finding work. It seemed that all the hard packages were either taken (e.g. my usual favorites, tiff and imagemagick, we done by others) or just too challenging (e.g. I don't feel quite comfortable tackling the LTS branch of the Linux kernel yet). I spent quite a bit of time trying to figure out what was wrong with pcre3, only to realise the "32" in the report was not about the architecture, but about the character width. Because of thise, I marked 4 CVEs (CVE-2017-7186, CVE-2017-7244, CVE-2017-7245, CVE-2017-7246) as "not-affected", since the 32-bith character support wasn't enabled in wheezy (or jessie, for that matter). I still spent some time trying to reproduce the issues, which require a compiler with an AddressSanitizer, something that was introduced in both Clang and GCC after Wheezy was released, which makes reproducing this fairly complicated... This allowed me to experiment more with Vagrant, however, and I have provided the Debian cloud team with a 32-bit Vagrant box that was merged in shortly after, although it doesn't show up yet in the official list of Debian images. Then I looked at the apparmor situation (CVE-2017-6507), Debian bug #858768). That was one tricky bug as well, since it's not a security issue in apparmor per se, but more an issue with things that assume a certain behavior from apparmor. I have concluded that Wheezy was not affected because there are no assumptions of proper isolation there - which are provided only starting from LXC 1.0 - and Docker is not in Wheezy. I also couldn't reproduce the issue on Jessie, but, as it turns out, the issue was sysvinit-specific, which is why I couldn't reproduce it under the default systemd configuration shipped with Jessie. I also looked at the various binutils security issues: as I reported on the mailing list, I didn't see anything serious enough in there to warrant a a security release and followed the lead of both the stable and Red Hat security teams by marking this "no-dsa". I similiarly reviewed the mp3splt security issues (specifically CVE-2017-5666) and was fairly puzzled by that issue, which seems to be triggered only the same address sanitization extensions than PCRE, although there was some pretty wild interplay with debugging flags in there. All in all, it seems we can't reproduce that issue in wheezy, but I do not feel confident enough in the results to push that issue aside for now. I finally uploaded the pending graphicsmagick issue (DLA-547-2), a regression update to fix a crash that was introduced in the previous release (DLA-547-1, mistakenly named DLA-574-1). Hopefully that release should clear up some of the confusion and fix the regression. I also released DLA-879-1 for the CVE-2017-6369 in firebird2.5 which was an interesting experiment: I couldn't reproduce the issue in a local VM. After following the Ubuntu setup tutorial, as I wasn't too familiar with the Firebird database until now (hint: the default username and password is sysdba/masterkey), I ended up assuming we were vulnerable and just backporting the patch after seeing the jessie folks push out a release just in case. I also looked at updating the ca-certificates package to deal with the pending WoSign/Startcom removal: I made an explicit list of the CAs that need to be removed after reviewing the Mozilla list. I also sent a patch for an unrelated issue where ca-certificates is writing to /usr/local (!!) in Debian bug #843722. I have also done some "meta" work in starting a discussion about fixing the missing DLA links in the tracker, as you will notice all of the above links lead to nowhere. Thanks to pabs, there are now some links but unfortunately there are about 500 DLAs missing from the website. We also discussed ways to Debian bug #859123, something which is currently a manual process. This is now in the hands of the excellent webmaster team. I have also filed a few missing security bugs (Debian bug #859135, Debian bug #859136), partly because I wanted to help the security team. But it turned out that I felt the script needed some improvements, so I submitted a patch to improve the script so it is easier to run.

Other projects As usual, there's the usual mixed bags of chaos: More stuff on Github...

Bits from Debian: Unknown parallel universe uses Debian

This post was an April Fools' Day joke. The space agencies running the International Space Station (ISS) reported that a laptop accidentally threw to space as waste in 2013 from the International State Station may have connected with a parallel Universe. This laptop was running Debian 6 and the ISS engineers managed to track its travel through the outer space. In early January, the laptop signal was lost but recovered back two weeks later in the same place. ISS engineers suspect that the laptop may had met and crossed a wormhole arriving a parallel Universe from where "somebody" sent it back later. Eventually the laptop was recovered and in an first analysis the ISS engineers found that the laptop have a dual boot: a partition running the Debian installation made by them and a second partition running what seems to be a Debian fork or derivative totally unknown until now. The engineers have been in contact with the Debian Project in the last weeks and a Debian group formed with delegates from different Debian teams have begun to study this new Debian derivative system. From the early results of this research, we can proudly say that somebody (or a group of beings) in a parallel universe understand Earth computers, and Debian, enough to: The work towards knowing better this new Universe and find a way to communicate with them has just began; all the Debian users and contributors are invited to join the effort to study the operating system found. We want to prepare our Community and our Universe to live and work peacefully and respectfully with the parallel Universe communities, in the true spirit of Free Software. In the following weeks a General Resolution will be proposed for updating our motto to "the multiversal operating system".

31 March 2017

Chris Lamb: Free software activities in March 2017

Here is my monthly update covering what I have been doing in the free software world (previous month):
Reproducible builds

Whilst anyone can inspect the source code of free software for malicious flaws, most software is distributed pre-compiled to end users. The motivation behind the Reproducible Builds effort is to permit verification that no flaws have been introduced either maliciously or accidentally during this compilation process by promising identical results are always generated from a given source, thus allowing multiple third-parties to come to a consensus on whether a build was compromised. I have generously been awarded a grant from the Core Infrastructure Initiative to fund my work in this area. This month I:
I also made the following changes to our tooling:
diffoscope

diffoscope is our in-depth and content-aware diff utility that can locate and diagnose reproducibility issues.

  • New features/optimisations:
    • Extract squashfs archive in one go rather than per-file, speeding up ISO comparison by ~10x.
    • Add support for .docx and .odt files via docx2txt & odt2txt. (#859056).
    • Add support for PGP files via pgpdump. (#859034).
    • Add support for comparing Pcap files. (#858867).
    • Compare GIF images using gifbuild. (#857610).
  • Bug fixes:
    • Ensure that we really are using ImageMagick and not the GraphicsMagick compatibility layer. (#857940).
    • Fix and add test for meaningless 1234-content metadata when introspecting archives. (#858223).
    • Fix detection of ISO9660 images processed with isohybrid.
    • Skip icc tests if the Debian-specific patch is not present. (#856447).
    • Support newer versions of cbfstool to avoid test failures. (#856446).
    • Update the progress bar prior to working to ensure filename is in sync.
  • Cleanups:
    • Use /usr/share/dpkg/pkg-info.mk over manual calls to dpkg-parsechangelog in debian/rules.
    • Ensure tests and the runtime environment can locate binaries in /usr/sbin (eg. tcpdump).

strip-nondeterminism

strip-nondeterminism is our tool to remove specific non-deterministic results from a completed build.

  • Fix a possible endless loop while stripping .ar files due to trusting the file's own file size data. (#857975).
  • Add support for testing files we should reject and include the filename when evaluating fixtures.

buildinfo.debian.net

buildinfo.debian.net is my experiment into how to process, store and distribute .buildinfo files after the Debian archive software has processed them.

  • Add support for Format: 1.0. (#20).
  • Don't parse Format: header as the source package version. (#21).
  • Show the reproducible status of packages.


Debian


I submitted my platform for the 2017 Debian Project Leader Elections. This was subsequently covered on LWN and I have been participating in the discussions on the debian-vote mailing list since then.

Debian LTS

This month I have been paid to work 14.75 hours on Debian Long Term Support (LTS). In that time I did the following:
  • "Frontdesk" duties, triaging CVEs, etc.
  • Issued DLA 848-1 for the freetype font library fixing a denial of service vulnerability.
  • Issued DLA 851-1 for wget preventing a header injection attack.
  • Issued DLA 863-1 for the deluge BitTorrent client correcting a cross-site request forgery vulnerability.
  • Issued DLA 864-1 for jhead (an EXIF metadata tool) patching an arbitrary code execution vulnerability.
  • Issued DLA 865-1 for the suricata intrusion detection system, fixing an IP protocol matching error.
  • Issued DLA 871-1 for python3.2 fixing a TLS stripping vulnerability in the smptlib library.
  • Issued DLA 873-1 for apt-cacher preventing a HTTP response splitting vulnerability.
  • Issued DLA 876-1 for eject to prevent an issue regarding the checking of setuid(2) and setgid(2) return values.
Uploads
  • python-django:
    • 1:1.10.6-1 New upstream bugfix release.
    • 1:1.11~rc1-1 New upstream release candidate.
  • redis:
    • 3:3.2.8-2 Avoid conflict between RuntimeDirectory and tmpfiles.d(5) both attempting to create /run/redis with differing permissions. (#856116)
    • 3:3.2.8-3 Revert the creation of a /usr/bin/redis-check-rdb to /usr/bin/redis-server symlink to avoid a dangling symlink if only the redis-tools package is installed. (#858519)
  • gunicorn 19.7.0-1 & 19.7.1-1 New upstream releases.
  • adminer 4.3.0-1 New upstream release.

Finally, I also made the following non-maintainer uploads (NMUs):
FTP Team

As a Debian FTP assistant I ACCEPTed 121 packages: 4pane, adql, android-platform-system-core, android-sdk-helper, braillegraph, deepnano, dh-runit, django-auth-ldap, django-dirtyfields, drf-extensions, gammaray, gcc-7, gnome-keysign, golang-code.gitea-sdk, golang-github-bluebreezecf-opentsdb-goclient, golang-github-bsm-redeo, golang-github-cupcake-rdb, golang-github-denisenkom-go-mssqldb, golang-github-exponent-io-jsonpath, golang-github-facebookgo-ensure, golang-github-facebookgo-freeport, golang-github-facebookgo-grace, golang-github-facebookgo-httpdown, golang-github-facebookgo-stack, golang-github-facebookgo-subset, golang-github-go-openapi-loads, golang-github-go-openapi-runtime, golang-github-go-openapi-strfmt, golang-github-go-openapi-validate, golang-github-golang-geo, golang-github-gorilla-pat, golang-github-gorilla-securecookie, golang-github-issue9-assert, golang-github-issue9-identicon, golang-github-jaytaylor-html2text, golang-github-joho-godotenv, golang-github-juju-errors, golang-github-kisielk-gotool, golang-github-kubernetes-gengo, golang-github-lpabon-godbc, golang-github-lunny-log, golang-github-makenowjust-heredoc, golang-github-mrjones-oauth, golang-github-nbutton23-zxcvbn-go, golang-github-neelance-sourcemap, golang-github-ngaut-deadline, golang-github-ngaut-go-zookeeper, golang-github-ngaut-log, golang-github-ngaut-pools, golang-github-ngaut-sync2, golang-github-optiopay-kafka, golang-github-quobyte-api, golang-github-renstrom-dedent, golang-github-sergi-go-diff, golang-github-siddontang-go, golang-github-smartystreets-go-aws-auth, golang-github-xanzy-go-cloudstack, golang-github-xtaci-kcp, golang-github-yohcop-openid-go, graywolf, haskell-raaz, hfst-ospell, hikaricp, iptraf-ng, kanboard-cli, kcptun, kreport, libbluray, libcatmandu-store-elasticsearch-perl, libcsfml, libnet-prometheus-perl, libosmocore, libpandoc-wrapper-perl, libseqlib, matrix-synapse, mockldap, nfs-ganesha, node-buffer, node-pako, nose-el, nvptx-tools, nx-libs, open-ath9k-htc-firmware, pagein, paleomix, pgsql-ogr-fdw, profanity, pyosmium, python-biotools, python-django-extra-views, python-django-otp, python-django-push-notifications, python-dnslib, python-gmpy, python-gmpy2, python-holidays, python-kanboard, python-line-profiler, python-pgpy, python-pweave, python-raven, python-xapian-haystack, python-xopen, r-cran-v8, repetier-host, ruby-jar-dependencies, ruby-maven-libs, ruby-psych, ruby-retriable, seafile-client, spyder-unittest, stressant, systray-mdstat, telegram-desktop, thawab, tigris, tnseq-transit, typesafe-config, vibe.d, x2goserver & xmlrpc-c. I additionally filed 14 RC bugs against packages that had incomplete debian/copyright files against: golang-github-cupcake-rdb, golang-github-sergi-go-diff, graywolf, hfst-ospell, libbluray, pgsql-ogr-fdw, python-gmpy, python-gmpy2, python-pgpy, python-xapian-haystack, repetier-host, telegram-desktop, tigris & xmlrpc-c.

29 March 2017

Daniel Pocock: Brexit: If it looks like racism, if it smells like racism and if it feels like racism, who else but a politician could argue it isn't?

Since the EU referendum got under way in the UK, it has become almost an everyday occurence to turn on the TV and hear some politician explaining "I don't mean to sound racist, but..." (example) Of course, if you didn't mean to sound racist, you wouldn't sound racist in the first place, now would you? The reality is, whether you like politics or not, political leaders have a significant impact on society and the massive rise in UK hate crimes, including deaths of Polish workers, is a direct reflection of the leadership (or profound lack of it) coming down from Westminster. Maybe you don't mean to sound racist, but if this is the impact your words are having, maybe it's time to shut up? Choosing your referendum Why choose to have a referendum on immigration issues and not on any number of other significant topics? Why not have a referendum on nuking Mr Putin to punish him for what looks like an act of terrorism against the Malaysian Airlines flight MH17? Why not have a referendum on cutting taxes or raising speed limits, turning British motorways into freeways or an autobahn? Why choose to keep those issues in the hands of the Government, but invite the man-in-a-white-van from middle England to regurgitate Nigel Farage's fears and anxieties about migrants onto a ballot paper? Even if David Cameron sincerely hoped and believed that the referendum would turn out otherwise, surely he must have contemplated that he was playing Russian Roulette with the future of millions of innocent people? Let's start at the top For those who are fortunate enough to live in parts of the world where the press provides little exposure to the antics of British royalty, an interesting fact you may have missed is that the Queen's husband, Prince Philip, Duke of Edinburgh is actually a foreigner. He was born in Greece and has Danish and German ancestry. Migration (in both directions) is right at the heart of the UK's identity. Queen and Prince Philip Home office minister Amber Rudd recently suggested British firms should publish details about how many foreign people they employ and in which positions. She argued this is necessary to help boost funding for training local people. If that is such a brilliant idea, why hasn't it worked for the Premier League? It is a matter of public knowledge how many foreigners play football in England's most prestigious division, so why hasn't this caused local clubs to boost training budgets for local recruits? After all, when you consider that England hasn't won a World Cup since 1966, what have they got to lose? Kevin Pietersen All this racism, it's just not cricket. Or is it? One of the most remarkable cricketers to play for England in recent times, Kevin Pietersen, dubbed "the most complete batsman in cricket" by The Times and "England's greatest modern batsman" by the Guardian, was born in South Africa. In the five years he was contracted to the Hampshire county team, he only played one match, because he was too busy representing England abroad. His highest position was nothing less than becoming England's team captain. Are the British superior to every other European citizen? One of the implications of the rhetoric coming out of London these days is that the British are superior to their neighbours, entitled to have their cake and eat it too, making foreigners queue up at Paris' Gare du Nord to board the Eurostar while British travelers should be able to walk or drive into European countries unchallenged. This superiority complex is not uniquely British, you can observe similar delusions are rampant in many of the places where I've lived, including Australia, Switzerland and France. America's Donald Trump has taken this style of politics to a new level. Look in the mirror Theresa May: after British 10-year old schoolboys Robert Thompson and Jon Venables abducted, tortured, murdered and mutilated 2 year old James Bulger in 1993, why not have all British schoolchildren fingerprinted and added to the police DNA database? Why should "security" only apply based on the country where people are born, their religion or skin colour? Jon Venables and Robert Thompson In fact, after Brexit, people like Venables and Thompson will remain in Britain while a Dutch woman, educated at Cambridge and with two British children will not. If that isn't racism, what is? Running foreigner's off the roads Theresa May has only been Prime Minister for less than a year but she has a history of bullying and abusing foreigners in her previous role in the Home Office. One example of this was a policy of removing driving licenses from foreigners, which has caused administrative chaos and even taken away the licenses of many people who technically should not have been subject to these regulations anyway. Shouldn't the DVLA (Britain's office for driving licenses) simply focus on the competence of somebody to drive a vehicle? Bringing all these other factors into licensing creates a hostile environment full of mistakes and inconvenience at best and opportunities for low-level officials to engage in arbitrary acts of racism and discrimination. Of course, when you are taking your country on the road to nowhere, who needs a driving license anyway? Run off the road What does "maximum control" over other human beings mean to you? The new British PM has said she wants "maximum control" over immigrants. What exactly does "maximum control" mean? Donald Trump appears to be promising "maximum control" over Muslims, Hitler sought "maximum control" over the Jews, hasn't the whole point of the EU been to avoid similar situations from ever arising again? This talk of "maximum control" in British politics has grown like a weed out of the UKIP. One of their senior figures has been linked to kidnappings and extortion, which reveals a lot about the character of the people who want to devise and administer these policies. Similar people in Australia aspire to jobs in the immigration department where they can extort money out of people for getting them pushed up the queue. It is no surprise that the first member of Australia's parliament ever sent to jail was put there for obtaining bribes and sexual favours from immigrants. When Nigel Farage talks about copying the Australian immigration system, he is talking about creating jobs like these for his mates. Even if "maximum control" is important, who really believes that a bunch of bullies in Westminster should have the power to exercise that control? Is May saying that British bosses are no longer competent to make their own decisions about who to employ or that British citizens are not reliable enough to make their own decisions about who they marry and they need a helping hand from paper-pushers in the immigration department? maximum control over Jewish people Echoes of the Third Reich Most people associate acts of mass murder with the Germans who lived in the time of Adolf Hitler. These are the stories told over and and over again in movies, books and the press. Look more closely, however, and it appears that the vast majority of Germans were not in immediate contact with the gas chambers. Even Gobels' secretary writes that she was completely oblivious to it all. Many people were simply small cogs in a big bad machine. The clues were there, but many of them couldn't see the big picture. Even if they did get a whiff of it, many chose not to ask questions, to carry on with their comfortable lives. Today, with mass media and the Internet, it is a lot easier for people to discover the truth if they look, but many are still reluctant to do so. Consider, for example, the fingerprint scanners installed in British post offices and police stations to fingerprint foreigners and criminals (as if they have something in common). If all the post office staff refused to engage in racist conduct the fingerprint scanners would be put out of service. Nonetheless, these people carry on, just doing their job, just following orders. It was through many small abuses like this, rather than mass murder on every street corner, that Hitler motivated an entire nation to serve his evil purposes. Technology like this is introduced in small steps: first it was used for serious criminals, then anybody accused of a crime, then people from Africa and next it appears they will try and apply it to all EU citizens remaining in the UK. How will a British man married to a French woman explain to their children that mummy has to be fingerprinted by the border guard each time they return from vacation? The Nazis pioneered biometric technology with the tracking numbers branded onto Jews. While today's technology is electronic and digital, isn't it performing the same function? There is no middle ground between "soft" and "hard" brexit An important point for British citizens and foreigners in the UK to consider today is that there is no compromise between a "soft" Brexit and a "hard" Brexit. It is one or the other. Anything less (for example, a deal that is "better" for British companies and worse for EU citizens) would imply that the British are a superior species and it is impossible to imagine the EU putting their stamp on such a deal. Anybody from the EU who is trying to make a life in the UK now is playing a game of Russian Roulette - sure, everything might be fine if it morphs into "soft" Brexit, but if Theresa May has her way, at some point in your life, maybe 20 years down the track, you could be rounded up by the gestapo and thrown behind bars for a parking violation. There has already been a five-fold increase in the detention of EU citizens in British concentration camps and they are using grandmothers from Asian countries to refine their tactics for the efficient removal of EU citizens. One can only wonder what type of monsters Theresa May has been employing to run such inhumane operations. This is not politics Edmund Burke's quote "The only thing necessary for the triumph of evil is for good men to do nothing" comes to mind on a day like today. Too many people think it is just politics and they can go on with their lives and ignore it. Barely half the British population voted in the referendum. This is about human beings treating each other with dignity and respect. Anything less is abhorrent and may well come back to bite.

25 March 2017

Russ Allbery: Spring haul

Work has been hellishly busy lately, so that's pretty much all I've been doing. The major project I'm working on should be basically done in the next couple of weeks, though (fingers crossed), so maybe I'll be able to surface a bit more after that. In the meantime, I'm still acquiring books I don't have time to read, since that's my life. In this case, two great Humble Book Bundles were too good of a bargain to pass up. There are a bunch of books in here that I already own in paperback (and hence showed up in previous haul posts), but I'm running low on shelf room, so some of those paper copies may go to the used bookstore to make more space. Kelley Armstrong Lost Souls (sff)
Clive Barker Tortured Souls (horror)
Jim Butcher Working for Bigfoot (sff collection)
Octavia E. Butler Parable of the Sower (sff)
Octavia E. Butler Parable of the Talents (sff)
Octavia E. Butler Unexpected Stories (sff collection)
Octavia E. Butler Wild Seed (sff)
Jacqueline Carey One Hundred Ablutions (sff)
Richard Chizmar A Long December (sff collection)
Jo Clayton Skeen's Leap (sff)
Kate Elliot Jaran (sff)
Harlan Ellison Can & Can'tankerous (sff collection)
Diana Pharoh Francis Path of Fate (sff)
Mira Grant Final Girls (sff)
Elizabeth Hand Black Light (sff)
Elizabeth Hand Saffron & Brimstone (sff collection)
Elizabeth Hand Wylding Hall (sff)
Kevin Hearne The Purloined Poodle (sff)
Nalo Hopkinson Skin Folk (sff)
Katherine Kurtz Camber of Culdi (sff)
Katherine Kurtz Lammas Night (sff)
Joe R. Lansdale Fender Lizards (mainstream)
Robert McCammon The Border (sff)
Robin McKinley Beauty (sff)
Robin McKinley The Hero and the Crown (sff)
Robin McKinley Sunshine (sff)
Tim Powers Down and Out in Purgatory (sff)
Cherie Priest Jacaranda (sff)
Alastair Reynolds Deep Navigation (sff collection)
Pamela Sargent The Shore of Women (sff)
John Scalzi Miniatures (sff collection)
Lewis Shiner Glimpses (sff)
Angie Thomas The Hate U Give (mainstream)
Catherynne M. Valente The Bread We Eat in Dreams (sff collection)
Connie Willis The Winds of Marble Arch (sff collection)
M.K. Wren Sword of the Lamb (sff)
M.K. Wren Shadow of the Swan (sff)
M.K. Wren House of the Wolf (sff)
Jane Yolen Sister Light, Sister Dark (sff)

19 March 2017

Dirk Eddelbuettel: Rcpp 0.12.10: Some small fixes

The tenth update in the 0.12.* series of Rcpp just made it to the main CRAN repository providing GNU R with by now over 10,000 packages. Windows binaries for Rcpp, as well as updated Debian packages will follow in due course. This 0.12.10 release follows the 0.12.0 release from late July, the 0.12.1 release in September, the 0.12.2 release in November, the 0.12.3 release in January, the 0.12.4 release in March, the 0.12.5 release in May, the 0.12.6 release in July, the 0.12.7 release in September, the 0.12.8 release in November, and the 0.12.9 release in January --- making it the fourteenth release at the steady and predictable bi-montly release frequency. Rcpp has become the most popular way of enhancing GNU R with C or C++ code. As of today, 975 packages on CRAN depend on Rcpp for making analytical code go faster and further. That is up by sixtynine packages over the two months since the last release -- or just over a package a day! The changes in this release are almost exclusively minor bugfixes and enhancements to documentation and features: James "coatless" Balamuta rounded out the API, I aki Ucar fixed a bug concerning one-character output, Jeroen Ooms allowed for finalizers on XPtr objects, Nathan Russell corrected handling of lower (upper) triangular matrices, Dan Dillon and I dealt with Intel compiler quirks for his algorithm.h header, and I added a C++17 plugin along with some (overdue!) documentation regarding the various C++ standards that are supported by Rcpp (which is in essence whatever your compiler supports, i.e., C++98, C++11, C++14 all the way to C++17 but always keep in mind what CRAN and different users may deploy).

Changes in Rcpp version 0.12.10 (2017-03-17)
  • Changes in Rcpp API:
    • Added new size attribute aliases for number of rows and columns in DataFrame (James Balamuta in #638 addressing #630).
    • Fixed single-character handling in Rstreambuf (I aki Ucar in #649 addressing #647).
    • XPtr gains a parameter finalizeOnExit to enable running the finalizer when R quits (Jeroen Ooms in #656 addressing #655).
  • Changes in Rcpp Sugar:
    • Fixed sugar functions upper_tri() and lower_tri() (Nathan Russell in #642 addressing #641).
    • The algorithm.h file now accomodates the Intel compiler (Dirk in #643 and Dan in #645 addressing issue #640).
  • Changes in Rcpp Attributes
    • The C++17 standard is supported with a new plugin (used eg for g++-6.2).
  • Changes in Rcpp Documentation:
    • An overdue explanation of how C++11, C++14, and C++17 can be used was added to the Rcpp FAQ.

Thanks to CRANberries, you can also look at a diff to the previous release. As always, even fuller details are on the Rcpp Changelog page and the Rcpp page which also leads to the downloads page, the browseable doxygen docs and zip files of doxygen output for the standard formats. A local directory has source and documentation too. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

17 March 2017

Shirish Agarwal: Science Day at GMRT, Khodad 2017

The whole team posing at the end of day 2 The above picture is the blend of the two communities from foss community and mozilla India. And unless you were there you wouldn t know who is from which community which is what FOSS is all about. But as always I m getting a bit ahead of myself. Akshat, who works at NCRA as a programmer, the standing guy on the left shared with me in January this year that this year too, we should have two stalls, foss community and mozilla India stalls next to each other. While we had the banners, we were missing stickers and flyers. Funds were and are always an issue and this year too, it would have been emptier if we didn t get some money saved from last year minidebconf 2016 that we had in Mumbai. Our major expenses included printing stickers, stationery and flyers which came to around INR 5000/- and couple of LCD TV monitors which came for around INR 2k/- as rent. All the labour was voluntary in nature, but both me and Akshat easily spending upto 100 hours before the event. Next year, we want to raise to around INR 10-15k so we can buy 1 or 2 LCD monitors and we don t have to think for funds for next couple of years. How will we do that I have no idea atm. Printing leaflets Me and Akshat did all the printing and stationery runs and hence had not been using my lappy for about 3-4 days. Come to the evening before the event and the laptop would not start. Coincidentally, or not few months or even last at last year s Debconf people had commented on IBM/Lenovo s obsession with proprietary power cords and adaptors. I hadn t given it much thought but when I got no power even after putting it on AC power for 3-4 hours, I looked up on the web and saw that the power cord and power adaptors were all different even in T440 and even that under existing models. In fact I couldn t find mine hence sharing it via pictures below. thinkpad power cord male thinkpad power adaptor female I knew/suspected that thinkpads would be rare where I was going, it would be rarer still to find the exact power cord and I was unsure whether it was the power cord at fault or adaptor or whatever goes for SMPS in laptop or memory or motherboard/CPU itself. I did look up the documentation at support.lenovo.com and was surprised at the extensive documentation that Lenovo has for remote troubleshooting. I did the usual take out the battery, put it back in, twiddle with the little hole in the bottom of the laptop, trying to switch on without the battery on AC mains, trying to switch on with battery power only but nothing worked. Couple of hours had gone by and with a resigned thought went to bed, convincing myself that anyways it s good I am not taking the lappy as it is extra-dusty there and who needs a dead laptop anyways. Update After the event was over, I did contact Lenovo support and within a week, with one visit from a service engineer, he was able to identify that it was a faulty cable which was at fault and not the the other things which I was afraid of. Another week gone by and lenovo replaced the cable. Going by service standards that I have seen of other companies, Lenovo deserves a gold star here for the prompt service they provided. I probably would end up subscribing to their extended 2-year warranty service when my existing 3 year warranty is about to be over. Next day, woke up early morning, two students from COEP hostel were volunteering and we made our way to NCRA, Pune University Campus. Ironically, though we were under the impression that we would be the late arrivals, it turned out we were the early birds. 5-10 minutes passed by and soon enough we were joined by Aniket and we played catch-up for a while. We hadn t met each other for a while so it was good to catch-up. Then slowly other people starting coming in and around 07:10-07:15 we started for GMRT, Khodad. Now I had been curious as had been hearing for years that the Pune-Nashik NH-50 highway would be concreted and widened to six-lane highways but the experience was below par. Came back and realized the proposal has now been pushed back to 2020. From the mozilla team, only Aniket was with us, the rest of the group was coming straight from Nashik. Interestingly, all the six people who came, came on bikes which depending upon how you look at it was either brave or stupid. Travelling on bikes on Indian highways you either have to be brave or stupid or both, we have more than enough accidents due to quality of road construction, road design, lane-changing drivers and many other issues. This is probably not the place for it hence will use some other blog post to rant about that. We reached around 10:00 hrs. IST and hung around till lunch as Akshat had all the marketing material, monitors etc. The only thing we had were couple of lappies and couple of SBC s, an RPI 3 and a BBB. Aarti Kashyap sharing something about SBC Our find for the event was Aarti Kashyap who you can see above. She is a third-year student at COEP and one of the rare people who chose to interact with hardware rather than software. From last several years, we had been trying, successfully and unsuccessfully to get more Indian women and girls interested into technology. It is a vicious circle as till a girl/woman doesn t volunteer we are unable to share our knowledge to the extent we can which leads them to not have much interest in FOSS or even technology in general. While there are groups are djangogirls, Pyladies and railgirls and even Outreachy which tries to motivate getting girls into computing but it s a long road ahead. We are short of both funds and ideas as to how to motivate more girls to get into computing and then to get into playing with hardware. I don t know where to start and end for whoever wants to play with hardware. From SBC s, routers to blade servers the sky is the limit. Again this probably isn t the place for it, hence probably we can chew it on more at some other blog post. This year, we had a lowish turnout due to the fact that the 12th board exams 1st paper was on the day we had opened. So instead of 20-25k, we probably had 5-7k fewer people pass through. There were two-three things that we were showing, we were showing Debian on one of the systems, we were showing the output from the SBC s on the other monitor but the glare kept hitting the monitors. While the organizers had done exemplary work over last year. They had taped the carpets on the ground so there was hardly any dust moving around. However, I wished the organizers had taken the pains to have two cloth roofs over our head instead of just one, the other roof head could be say 2 feet up, this would have done two things a. It probably would have cooled the place a bit more as b. We could get diffused sunlight which would have lessened the glare and reflection the LCD s kept throwing back. At times we also got people to come to our side as can be seen in Aarti s photo as can be seen above. If these improvements can be made for next year, this would result in everybody in our Pandal would benefit, not just us and mozilla. This would be benefiting around 10-15 organizations which were within the same temporary structure. Of course, it depends very much on the budget they are able to have and people who are executing, we can just advise. The other thing which had been missing last year and this year is writing about Single Board Computers in Marathi. If we are to promote them as something to replace a computer or something for a younger brother/sister to learn computing upon at a lower cost, we need leaflets written in their language to be more effective. And this needs to be in the language and mannerisms that people in that region understand. India, as probably people might have experienced is a dialect-prone country. Which means every 2-5 kms, the way the language is spoken is different from anywhere else. The Marathi spoken by somebody who has lived in Ravivar Peth for his whole life and a person who has lived in say Kothrud are different. The same goes from any place and this place, Khodad, Narayangaon would have its own dialect, its own mini-codespeak. Just to share, we did have one in English but it would have been a vast improvement if we could do it in the local language. Maybe we can discuss about this and ask for help from people. Outside, Looking in Mozillians helping FOSS community and vice-versa What had been interesting about the whole journey were the new people who were bringing all their passion and creativity to the fore. From the mozilla community, we had Akshay who is supposed to be a wizard on graphics, animation, editing anything to do with the visual medium. He shared some of the work he had done and also shared a bit about how blender works with people who wanted to learn about that. Mayur, whom you see in the picture pointing out something about FOSS and this was the culture that we strove to have. I know and love and hate the browser but haven t been able to fathom the recklessness that Mozilla has been doing the last few years, which has just been having one mis-adventure after another. For instance, mozstumbler was an effort which I thought would go places. From what little I understood, it served/serves as a user-friendly interface to a potential user while still sharing all the data with OSM . They (Mozilla) seems/seemed to have a fatalistic take as it provided initial funding but then never fully committing to the project. Later, at night we had the whole free software and open-source sharings where I tried to emphasize that without free software, the term open-source would not have come into existence. We talked and talked and somewhere around 02:00 I slept, the next day was an extension of the first day itself where we ribbed each other good-naturedly and still shared whatever we could share with each other. I do hope that we continue this tradition for great many years to come and engage with more and more people every passing year.
Filed under: Miscellenous Tagged: #budget, #COEP< #volunteering, #debian, #Events, #Expenses, #mozstumbler, #printing, #SBC's, #Science Day 2017, #thinkpad cable issue, FOSS, mozilla

Antonio Terceiro: Patterns for Testing Debian Packages

At the and of 2016 I had the pleasure to attend the 11th Latin American Conference on Pattern Languages of Programs, a.k.a SugarLoaf PLoP. PLoP is a series of conferences on Patterns (as in Design Patterns ), a subject that I appreciate a lot. Each of the PLoP conferences but the original main big conference has a funny name. SugarLoaf PLoP is called that way because its very first edition was held in Rio de Janeiro, so the organizers named it after a very famous mountain in Rio. The name stuck even though a long time has passed since it was held in Rio for the last time. 2016 was actually the first time SugarLoaf PLoP was held outside of Brazil, finally justifying the Latin American part of its name. I was presenting a paper I wrote on patterns for testing Debian packages. The Debian project funded my travel expenses through the generous donations of its supporters. PLoP s are very fun conferences with a relaxed atmosphere, and is amazing how many smart (and interesting!) people gather together for them. My paper is titled Patterns for Writing As-Installed Tests for Debian Packages , and has the following abstract:
Large software ecosystems, such as GNU/Linux distributions, demand a large amount of effort to make sure all of its components work correctly invidually, and also integrate correctly with each other to form a coherent system. Automated Quality Assurance techniques can prevent issues from reaching end users. This paper presents a pattern language originated in the Debian project for automated software testing in production-like environments. Such environments are closer in similarity to the environment where software will be actually deployed and used, as opposed to the development environment under which developers and regular Continuous Integration mechanisms usually test software products. The pattern language covers the handling of issues arising from the difference between development and production-like environments, as well as solutions for writing new, exclusive tests for as-installed functional tests. Even though the patterns are documented here in the context of the Debian project, they can also be generalized to other contexts.
In practical terms, the paper documents a set of patterns I have noticed in the last few years, when I have been pushing the Debian Continous Integration project. It should be an interesting read for people interested in the testing of Debian packages in their installed form, as done with autopkgtest. It should also be useful for people from other distributions interested in the subject, as the issues are not really Debian-specific. I have recently finished the final version of the paper, which should be published in the ACM Digital Library at any point now. You can download a copy of the paper in PDF. Source is also available, if you are into markdown, LaTeX, makefiles and this sort of thing. If everything goes according to plan, I should be presenting a talk on this at the next Debconf in Montreal.

16 March 2017

Rapha&#235;l Hertzog: Freexian s report about Debian Long Term Support, February 2017

A Debian LTS logoLike each month, here comes a report about the work of paid contributors to Debian LTS. Individual reports In January, about 154 work hours have been dispatched among 13 paid contributors. Their reports are available: Evolution of the situation The number of sponsored hours increased slightly thanks to Bearstech and LiHAS joining us. The security tracker currently lists 45 packages with a known CVE and the dla-needed.txt file 39. The number of open issues continued its slight increase, this time it could be explained by the fact that many contributors did not spend all the hours allocated (for various reasons). There s nothing worrisome at this point. Thanks to our sponsors New sponsors are in bold.

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Enrico Zini: Django signing signs, does not encrypt

As is says in the documentation. django.core.signing signs, and does not encyrpt. Even though signing.dumps creates obscure-looking tokens, they are not encrypted, and here's a proof: 
>>> from django.core import signing
>>> a = signing.dumps( "action":"set-password", "username": "enrico", "password": "SECRET" )
>>> from django.utils.encoding import force_bytes
>>> print(signing.b64_decode(force_bytes(a.split(":",1)[0])))
b' "action":"set-password","password":"SECRET","username":"enrico" '
I'm writing it down so one day I won't be tempted to think otherwise.

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