The `G_FILE_CREATE_REPLACE_DESTINATION` flag is equivalent to unlinking
the destination file and re-creating it from scratch. That did
previously work, but in the process the code would call `open(O_CREAT)`
on the file. If the file was a dangling symlink, this would create the
destination file (empty). That’s not an intended side-effect, and has
security implications if the symlink is controlled by a lower-privileged
process.
Fix that by not opening the destination file if it’s a symlink, and
adjusting the rest of the code to cope with
- the fact that `fd == -1` is not an error iff `is_symlink` is true,
- and that `original_stat` will contain the `lstat()` results for the
symlink now, rather than the `stat()` results for its target (again,
iff `is_symlink` is true).
This means that the target of the dangling symlink is no longer created,
which was the bug. The symlink itself continues to be replaced (as
before) with the new file — this is the intended behaviour of
`g_file_replace()`.
The behaviour for non-symlink cases, or cases where the symlink was not
dangling, should be unchanged.
Includes a unit test.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Fixes: #2325
This currently just implements the same functionality as the existing
`stat()`/`fstat()`/`fstatat()`/`lstat()` calls, although where a reduced
field set is requested it may return faster.
Helps: #1970
This is a step towards supporting `statx()`, which allows the set of
fields it returns to be specified by the caller. Currently, the existing
`stat()` and `fstat()` calls continue to be made, and there are no
behavioural changes — but the new wrapper functions will be extended in
future.
Helps: #1970
chmod() technically only accepts file modes, not the file type and mode
as returned by stat(). Filter by `S_IFMT` to avoid sending the file
type (regular file, directory, symbolic link, etc.).
In practice, chmod() ignores anything except the file mode, but we might
as well comply with the specification.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
More vectors will give an error and we can simply clamp here and
consider it like a short write instead.
In case of GSocketOutputStream this is done here instead of inside
GSocket before calling sendmsg() because we we can't generically handle
short writes when sending messages on a socket, e.g. for datagram
sockets this causes only part of the datagram to be sent and an error
would be more useful in this case than sending corrupted data.
Also reduce the fallback limit to 16 in gsocket.c as that's the minimum
value required by POSIX and add a static assertion that the limit is
never bigger than G_MAXINT as that's the type recvmmsg/sendmmsg take.
This commit adds new W32-only functions to gstdio.c,
and a new header file, gstdioprivate.h.
These functions are:
g_win32_stat_utf8()
g_win32_lstat_utf8()
g_win32_fstat()
and they fill a private structure, GWin32PrivateStat,
which has all the fields that normal stat has, as well as some
extras.
These functions are then used throughout glib and gio to get better
data about the system. Specifically:
* Full, 64-bit size, guaranteed (g_stat() is forced to use 32-bit st_size)
* Full, 64-bit file identifier (st_ino is 0 when normal stat() is used, and still is)
* W32 File attributes (which stat() doesn't report); in particular, this allows
symlinks to be correctly identified
* Full, 64-bit time, guaranteed (g_stat() uses 32-bit st_*time on 32-bit Windows)
* Allocated file size (as a W32 replacement for the missing st_blocks)
st_mode remains unchanged (thus, no S_ISLNK), so when these are given back to
glib users (via g_stat(), for example, which is now implemented by calling g_win32_stat_utf8),
this field does not contain anything unexpected.
g_lstat() now calls g_win32_lstat_utf8(), which works on symlinks the way it's supposed to.
Also adds the g_win32_readlink_utf8() function, which behaves like readlink()
(including its inability to return 0-terminated strings and inability to say how large
the output buffer should be; these limitations are purely for compatibility with
existing glib code).
Thus, symlink support should now be much better, although far from being complete.
A new W32-only test in gio/tests/file.c highlights the following features:
* allocated size
* 64-bit time
* unique file IDs
https://bugzilla.gnome.org/show_bug.cgi?id=788180
Prevent the situation where errno is set by function A, then function B
is called (which is typically _(), but could be anything else) and it
overwrites errno, then errno is checked by the caller.
errno is a horrific API, and we need to be careful to save its value as
soon as a function call (which might set it) returns. i.e. Follow the
pattern:
int errsv, ret;
ret = some_call_which_might_set_errno ();
errsv = errno;
if (ret < 0)
puts (strerror (errsv));
This patch implements that pattern throughout GLib. There might be a few
places in the test code which still use errno directly. They should be
ported as necessary. It doesn’t modify all the call sites like this:
if (some_call_which_might_set_errno () && errno == ESOMETHING)
since the refactoring involved is probably more harmful than beneficial
there. It does, however, refactor other call sites regardless of whether
they were originally buggy.
https://bugzilla.gnome.org/show_bug.cgi?id=785577
FreeBSD, DragonflyBSD and NetBSD support O_NOFOLLOW, but they use error
numbers that are different from what POSIX standard specifies. They are
not going to change the behavior, and existing programs on these systems
already take advantage of this difference. To support them, we have to
add a check in GIO to use different error numbers on these systems.
https://bugzilla.gnome.org/show_bug.cgi?id=775593
If a backup file is created, opened successfully, then fstat() on it
fails (perhaps due to another process deleting it in the mean time?),
the FD will be leaked.
Coverity issue: #1159485https://bugzilla.gnome.org/show_bug.cgi?id=730187
In Windows development environments that have it, <unistd.h> is mostly
just a wrapper around several other native headers (in particular,
<io.h>, which contains read(), close(), etc, and <process.h>, which
contains getpid()). But given that some Windows dev environments don't
have <unistd.h>, everything that uses those functions on Windows
already needed to include the correct Windows header as well, and so
there is never any point to including <unistd.h> on Windows.
Also, remove some <unistd.h> includes (and a few others) that were
unnecessary even on unix.
https://bugzilla.gnome.org/show_bug.cgi?id=710519
Assume unix platforms support the original POSIX.1 standard.
Specifically, assume that if G_OS_UNIX, then we have chown(),
getcwd(), getgrgid(), getpwuid(), link(), <grp.h>, <pwd.h>,
<sys/types.h>, <sys/uio.h>, <sys/wait.h>, and <unistd.h>.
Additionally, since all versions of Windows that we care about also
have <sys/types.h>, we can remove HAVE_SYS_TYPES_H checks everywhere.
Also remove one include of <sys/times.h>, and the corresponding
configure check, since the include is not currently needed (and may
always have just been a typo for <sys/time.h>).
https://bugzilla.gnome.org/show_bug.cgi?id=710519
As it turns out, we have examples of internal functions called
type_name_get_private() in the wild (especially among older libraries),
so we need to use a name for the per-instance private data getter
function that hopefully won't conflict with anything.
Previously, g_file_copy() would (on Unix) create files with the
default mode of 644. For applications which might at user request
copy arbitrary private files such as ~/.ssh or /etc/shadow, a
world-readable copy would be temporarily exposed.
This patch is suboptimal in that it *only* fixes g_file_copy()
for the case where both source and destination are instances of
GLocalFile on Unix.
The reason for this is that the public GFile APIs for creating files
allow very limited control over the access permissions for the created
file; one can either say a file is "private" or not. Fixing
this by adding e.g. g_file_create_with_attributes() would make sense,
except this would entail 8 new API calls for all the variants of
_create(), _create_async(), _replace(), _replace_async(),
_create_readwrite(), _create_readwrite_async(), _replace_readwrite(),
_replace_readwrite_async(). That can be done as a separate patch
later.
https://bugzilla.gnome.org/show_bug.cgi?id=699959
There are two benefits to this:
1) We can centralize any operating system specific knowledge of
close-vs-EINTR handling. For example, while on Linux we should never
retry, if someone cared enough later about HP-UX, they could come by
and change this one spot.
2) For places that do care about the return value and want to provide
the caller with a GError, this function makes it convenient to do so.
Note that gspawn.c had an incorrect EINTR loop-retry around close().
https://bugzilla.gnome.org/show_bug.cgi?id=682819
Non-technical users won't know that "stating" refers to stat(2), so we
just use "error when getting information" now.
Signed-off-by: Federico Mena Quintero <federico@gnome.org>
- Fix various #include issues
- Change #error to #warning for the EXTERNAL authentication mechanism.
It is not clear if this should work on Win32 at all.
- Call close() before unlink() for the SHA1 keyring
- Change #error to #warning so we don't forget to do
permission checking of the .dbus-keyrings directory
- Use Win32 SID for the SHA1 auth mech
- Apparently we can't use word 'interface' as an identifier
- Implement a _g_dbus_win32_get_user_sid() function. For now it's
private. Don't know if it should be public somewhere. Maybe in
a future GCredentials support for Win32? I don't know.
- GFileDescriptorBased is not available on Win32. So avoid using
it in GLocalFile stuff. Now, Win32 still uses GLocalFile + friends
(which works with file descriptors) so expose a private function
to get the fd for an OutputStream so things still work.
- Fixup gio.symbols
- Fixup tests/gdbus-peer.c so it builds
With this, at least things compile and the gdbus-peer.exe test case
passes. Which is a great start. I've tested this by cross-compiling on
a x86_64 Fedora 13 host using mingw32 and running the code on a 32-bit
Windows 7 box.
https://bugzilla.gnome.org/show_bug.cgi?id=619142
Signed-off-by: David Zeuthen <davidz@redhat.com>
Previous code used g_mkstemp(). But when using
G_FILE_CREATE_REPLACE_DESTINATION, no attempt was made to ensure proper
mode and flags of the created temporary file. The visible issue was that
the file was always created with mode 0600 as opposed to using 0666.
(The invisible issue was that O_RDWR was used instead of O_WRONLY.)
This implements all the GIOStream file ops for local files.
We use the "fallback to output stream" for all GFileIOStream ops.
Some helpers stuff was added to the local input and output streams
so they could be reused.
2009-03-16 Alexander Larsson <alexl@redhat.com>
Bug 575555 – Use fsync() when replacing files to avoid data loss on crash
* configure.in:
Look for fsync().
* glib/gfileutils.c:
(write_to_temp_file):
fsync temp file if destination file exists
2009-03-16 Alexander Larsson <alexl@redhat.com>
Bug 575555 – Use fsync() when replacing files to avoid data loss on crash
* glocalfileoutputstream.c:
(g_local_file_output_stream_close):
(_g_local_file_output_stream_replace):
fsync temp file before closing if replacing target file
svn path=/trunk/; revision=7991
2009-02-18 Alexander Larsson <alexl@redhat.com>
Bug 560564 – Replacing a symlink with its linked file truncates the original file
* gioenums.h:
Add G_FILE_CREATE_REPLACE_DESTINATION
* glocalfileoutputstream.c:
(handle_overwrite_open):
(_g_local_file_output_stream_replace):
Handle G_FILE_CREATE_REPLACE_DESTINATION when overwriting files.
* gfile.c:
(file_copy_fallback):
Pass G_FILE_CREATE_REPLACE_DESTINATION to g_file_replace when copying
with overwrite.
svn path=/trunk/; revision=7880
2008-08-23 Tor Lillqvist <tml@novell.com>
Bug 548988 - g_file_replace fails on Windows when the target file
exists already
* glocalfileoutputstream.c (g_local_file_output_stream_close): On
Windows, close the file before renaming it (in case we have been
writing to a file with a temporary name).
(g_local_file_output_stream_close, handle_overwrite_open): Use
GLocalFileStat instead of plain struct stat, for passing to
_g_local_file_info_create_etag(). Thus also use _fstati64()
instead of plain fstat() on Windows.
svn path=/trunk/; revision=7388
2008-07-01 Cody Russell <bratsche@gnome.org>
* gio/gioenums.h:
* gio/giotypes.h:
Moved all relevant typedefs into these files.
* gio/*.[ch]:
Updated wrt added files.
Split types into separate file for easier maintainership. (#538564)
svn path=/trunk/; revision=7127
2008-06-16 Michael Natterer <mitch@imendio.com>
* *.c: chain up unconditionally in finalize() and dispose(). Also
don't dereference these function pointers when calling them since
that has no meaning at all.
svn path=/trunk/; revision=7048
2008-02-18 Alexander Larsson <alexl@redhat.com>
* glocalfile.c:
* glocalfileinfo.c:
* glocalfileoutputstream.c:
Use g_unlink/g_rename instead of unlink/rename;
do not pass raw filenames to g_set_error. (#517239)
Patch from Yevgen Muntyan.
svn path=/trunk/; revision=6533
