Commit Graph

124 Commits (d6e75be3769d9750eba70fa5fbef918a5a4bf8d7)

Author SHA1 Message Date
Sebastian Lackner 616a468180 syscallcompat: Improve the Openat and Mknodat syscall emulation
This avoids the conversion to an absolute path.
2017-12-01 09:41:52 +01:00
Sebastian Lackner f30522a0c1 syscallcompat: Fix syscall emulation for absolute paths
For absolute paths, the file descriptor should be ignored. In such a case
there is also no need to hold the lock or change the working directory.
2017-12-01 09:41:52 +01:00
Jakob Unterwurzacher e97c23e083 syscallcompat: check that we get NOFOLLOW wherever possible
...and fix the instances where the AT_SYMLINK_NOFOLLOW /
O_NOFOLLOW / O_EXCL flag was missing.
2017-11-30 19:40:53 +01:00
Jakob Unterwurzacher 22282aefe6 syscallcompat: add tests for emulated syscalls
Also fix the bug in emulateFchmodat that was found by the tests.
2017-11-30 19:10:21 +01:00
Jakob Unterwurzacher bd79a8cd0d syscallcompat: build emulated syscalls under linux, too
This will allow to test them under linux as well.
2017-11-30 17:07:55 +01:00
Sebastian Lackner 614745ee57 fusefrontend: allow_other: close race between mkdir and chown
Fixes the same problem as described in 72b975867a,
except for directories instead of device nodes.
2017-11-29 13:28:04 +01:00
Sebastian Lackner 0162392a28 fusefrontend: Use Fchmodat to implement Chmod 2017-11-29 12:55:41 +01:00
Sebastian Lackner 0f44c617d0 syscallcompat: Introduce unlinkat syscall with flags argument 2017-11-29 12:41:23 +01:00
Sebastian Lackner 5a56810603 fusefrontend: Use the Symlinkat syscall for longname handling 2017-11-28 09:28:06 +01:00
Sebastian Lackner 8c5069c637 syscallcompat: Fix Fchownat syscall wrapper on darwin
* Acquire the lock before reading the current directory
* Fix a file descriptor leak
2017-11-28 09:28:06 +01:00
Jakob Unterwurzacher 72b975867a fusefronted: allow_other: close race between mknod and chown
If the user manages to replace the directory with
a symlink at just the right time, we could be tricked
into chown'ing the wrong file.

This change fixes the race by using fchownat, which
unfortunately is not available on darwin, hence a compat
wrapper is added.

Scenario, as described by @slackner at :

1. Create a forward mount point with `plaintextnames` enabled
2. Mount as root user with `allow_other`
3. For testing purposes create a file `/tmp/file_owned_by_root`
   which is owned by the root user
4. As a regular user run inside of the GoCryptFS mount:

mkdir tempdir
mknod tempdir/file_owned_by_root p &
mv tempdir tempdir2
ln -s /tmp tempdir

When the steps are done fast enough and in the right order
(run in a loop!), the device file will be created in
`tempdir`, but the `lchown` will be executed by following
the symlink. As a result, the ownership of the file located
at `/tmp/file_owned_by_root` will be changed.
2017-11-27 21:04:45 +01:00
Jakob Unterwurzacher 34547a6c39 tests: don't read /proc, the number of entries changes too quickly
This could lead to test failures like this:

  --- FAIL: TestGetdents (0.02s)
  	getdents_test.go:57: len(getdentsEntries)=362, len(readdirEntries)=360
2017-10-22 18:13:08 +02:00
Jakob Unterwurzacher 538cae610c syscallcompat: Getdents: warn once if we get DT_UNKNOWN
...and if Getdents is not available at all.

Due to this warning I now know that SSHFS always returns DT_UNKNOWN:

    gocryptfs[8129]: Getdents: convertDType: received DT_UNKNOWN, falling back to Lstat

This behavoir is confirmed at

    "With sshfs, I finally found that obscure case. The dtype is always set to DT_UNKNOWN [...]"
2017-09-03 15:05:54 +02:00
Jakob Unterwurzacher e50a6a57e5 syscallcompat: implement Getdents()
The Readdir function provided by os is inherently slow because
it calls Lstat on all files.

Getdents gives us all the information we need, but does not have
a proper wrapper in the stdlib.

Implement the "Getdents()" wrapper function that calls
syscall.Getdents() and parses the returned byte blob to a
fuse.DirEntry slice.
2017-08-15 19:03:57 +02:00
Jakob Unterwurzacher a4563e21ec main, syscallcompat: use Dup3 instead of Dup2
Dup2 is not implemented on linux/arm64.

Fixes .

Also adds cross-compilation to CI.
2017-06-18 15:43:22 +02:00
Jakob Unterwurzacher 8bbc1038fe syscallcompat: OSX compat: fix variable warnings
As suggested by
2017-02-16 19:23:17 +01:00
Jakob Unterwurzacher a4956fa6bf A few more lint fixes 2016-10-04 23:30:05 +02:00
Valient Gough b764917cd5 lint fixes 2016-10-04 23:18:33 +02:00
Jakob Unterwurzacher e8a234f658 Add godoc comments to all internal packages 2016-07-06 21:51:25 +02:00
Jakob Unterwurzacher 741bf0726e syscallcompat: OSX: add Mknodat wrapper
Protip: find naked *at syscalls using:

   git grep "syscall." | grep "at(" | grep -v syscallcompat
2016-07-03 20:22:22 +02:00
Jakob Unterwurzacher d8524c7369 syscallcompat: OSX: add Unlinkat wrapper
Also, replace remaining naked syscall.Openat calls.
2016-07-03 20:17:40 +02:00
Jakob Unterwurzacher 79851bf6cc syscallcompat: OSX: add Renamat wrapper
Adds a poor man's renameat implementation for OSX.
2016-07-03 20:05:32 +02:00
Jakob Unterwurzacher 9b725c15cf syscallcompat: OSX: add Fallocate and Openat wrappers
...and convert all calls to syscall.{Fallocate,Openat}
to syscallcompat .

Both syscalls are not available on OSX. We emulate Openat and just
return EOPNOTSUPP for Fallocate.
2016-07-03 19:18:34 +02:00
Jakob Unterwurzacher c9a472c12f syscallcompat: move syscall wrapper to their own package
We will get more of them as OSX also lacks support for openat.
2016-07-03 17:51:40 +02:00