This is to track down what file in .git/annex/ is being written to via a
temp file when the repository is read-only.
Sponsored-by: Dartmouth College's Datalad project
9cb250f7be got the ones in RawFilePath,
but there were others that used the one from unix-compat, which fails at
runtime on windows. To avoid this,
import System.PosixCompat.Files hiding removeLink
This commit was sponsored by Ethan Aubin.
Fixed several cases where files were created without file mode bits that
the umask would usually set. This included exports to the directory special
remote, torrent files used by the bittorrent special remote, hooks written
by git-annex init, and some log files in .git/annex/
Audited all calls, looking for ones that didn't want the umask bits to be
set. All such turned out to already set the specific restrictive file mode
they wanted.
Also audited for other calls to openTempFile, and all are ok,
except for viaTmp which will need further work.
Remote.Directory fixed to set umask mode when writing to an export,
although it has another one using viaTmp that's not fixed.
Will make exports that are published via a http server running as
another user work, for example.
Remote.BitTorrent fixed to set umask mode when downloading the torrent
file. Normally this does not matter as that file does not hang around
after the download, but if a bittorrent download were started by one user,
got interrupted and then another user ran it, this will let them access
the torrent file created by the first user.
Also tested what happens if the other special remote has importtree=yes
and exporttree=yes, and in that case, download via httpalso works too,
without needing to implement any importtree methods here.
It might be possible to make it automatically set exporttree=yes if the
--sameas does. Didn't try, will probably be layering issues.
Or perhaps it should be inherited by sameas like some
other configs? But then, wouldn't it also make sense to inherit
importree=yes? But as shown here, it's not needed by this kind of
remote.
Fourth or fifth try at this and finally found a way to make it work.
Absurd amount of busy-work forced on me by change in cabal's behavior.
Split up Utility modules that need posix stuff out of ones used by
Setup. Various other hacks around inability for Setup to use anything
that ifdefs a use of unix.
Probably lost a full day of my life to this.
This is how build systems make their users hate them. Just saying.
That version has my patches for the problems that Utility.PosixFiles
was working around, so am able to get rid of that module now.
This will later allow bringing back the custom-setup stanza in the cabal
file. It will need to depend on unix-compat 0.5 on all OS's, which I'm
not ready to do yet.
This commit was sponsored by Nick Daly on Patreon.
This avoids needing to deal with the complexity of partially transferred
files in the export. We'd not be able to resume uploading to such a file
anyway, so just avoid them.
The implementation in Remote.Directory is not completely ideal, because
it could leave the temp file hanging around in the export directory.
This only happens if it's killed with -9, or there's a power failure;
normally viaTmp cleans up after itself, even when interrupted. I could
not see a better way to do it though, since the export directory might
be the root of a filesystem.
Also some design thoughts on resuming, which depend on storeExport being
atomic.
This commit was sponsored by Fernando Jimenez on Partreon.
It started exporting a isSymbolicLink which supports windows. But,
git-annex does no use symlinks on windows yet and this conflicts with the
function by the same name from unix-compat, so hide it.
http://bugs.debian.org/807341
* Fix insecure temporary permissions when git-annex repair is used in
in a corrupted git repository.
Other calls to withTmpDir didn't leak any potentially private data,
but repair clones the git repository to a temp directory which is made
using the user's umask. Thus, it might expose a git repo that is
otherwise locked down.
* Fix potential denial of service attack when creating temp dirs.
Since withTmpDir used easily predictable temporary directory names,
an attacker could create foo.0, foo.1, etc and as long as it managed to
keep ahead of it, could prevent it from ever returning.
I'd rate this as a low utility DOS attack. Most attackers in a position
to do this could just fill up the disk /tmp is on to prevent anything
from writing temp files. And few parts of git-annex use withTmpDir
anyway, so DOS potential is quite low.
Examined all callers of withTmpDir and satisfied myself that
switching to mkdtmp and so getting a mode 700 temp dir wouldn't break any
of them.
Note that withTmpDirIn continues to not force temp dir to 700.
But it's only used for temp directories inside .git/annex/wherever/
so that is not a problem.
Also re-audited all other uses of temp files and dirs in git-annex.
This is certianly a cabal bug for not passing the build options in the
cabal file when building Setup.hs.
And, why oh why did ghc enable this warning by default? So unhappy with
this choice.
Removed old extensible-exceptions, only needed for very old ghc.
Made webdav use Utility.Exception, to work after some changes in DAV's
exception handling.
Removed Annex.Exception. Mostly this was trivial, but note that
tryAnnex is replaced with tryNonAsync and catchAnnex replaced with
catchNonAsync. In theory that could be a behavior change, since the former
caught all exceptions, and the latter don't catch async exceptions.
However, in practice, nothing in the Annex monad uses async exceptions.
Grepping for throwTo and killThread only find stuff in the assistant,
which does not seem related.
Command.Add.undo is changed to accept a SomeException, and things
that use it for rollback now catch non-async exceptions, rather than
only IOExceptions.
Some remotes like External need to run store and retrieve actions in Annex,
not IO. In order to do that lift, I had to dive pretty deep into the
utilities, making Utility.Gpg and Utility.Tmp be partly converted to using
MonadIO, and Control.Monad.Catch for exception handling.
There should be no behavior changes in this commit.
This commit was sponsored by Michael Barabanov.
Started with a problem when running addurl on a really long url,
because the whole url is munged into the filename. Ended up doing
a fairly extensive review for places where filenames could get too large,
although it's hard to say I'm not missed any..
Backend.Url had a 128 character limit, which is fine when the limit is 255,
but not if it's a lot shorter on some systems. So check the pathconf()
limit. Note that this could result in fromUrl creating different keys
for the same url, if run on systems with different limits. I don't see
this is likely to cause any problems. That can already happen when using
addurl --fast, or if the content of an url changes.
Both Command.AddUrl and Backend.Url assumed that urls don't contain a
lot of multi-byte unicode, and would fail to truncate an url that did
properly.
A few places use a filename as the template to make a temp file.
While that's nice in that the temp file name can be easily related back to
the original filename, it could lead to `git annex add` failing to add a
filename that was at or close to the maximum length.
Note that in Command.Add.lockdown, the template is still derived from the
filename, just with enough space left to turn it into a temp file.
This is an important optimisation, because the assistant may lock down
a bunch of files all at once, and using the same template for all of them
would cause openTempFile to iterate through the same set of names,
looking for an unused temp file. I'm not very happy with the relatedTemplate
hack, but it avoids that slowdown.
Backend.WORM does not limit the filename stored in the key.
I have not tried to change that; so git annex add will fail on really long
filenames when using the WORM backend. It seems better to preserve the
invariant that a WORM key always contains the complete filename, since
the filename is the only unique material in the key, other than mtime and
size. Since nobody has complained about add failing (I think I saw it
once?) on WORM, probably it's ok, or nobody but me uses it.
There may be compatability problems if using git annex addurl --fast
or the WORM backend on a system with the 255 limit and then trying to use
that repo in a system with a smaller limit. I have not tried to deal with
those.
This commit was sponsored by Alexander Brem. Thanks!
