The child process needs access to the handle to be able to
unload it when switching user context.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Does this work? There's not much feedback given.
TODO: We might want to try unloading the user profile at process
exit as well, FWIW.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
s4uath was only callable to create an impersonation token so
far. Rework the function to allow creating an identification
token for informational purposes even from untrusted processes.
Take domainname and username instead of a passwd pointer to be
more multi-purpose.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Under WOW64 on 64 bit Windows 7, MsV1_0S4ULogon appears to be
unimplemented, probably under Vista as well. Re-enable
create_token method, to allow basic seteuid on W7 WOW64 and
Vista as well.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
In preparation to protect fork() against dll- and exe-updates, create
hardlinks to the main executable and each loaded dll in subdirectories
of /var/run/cygfork/, if that one exists on the NTFS file system.
The directory names consist of the user sid, the main executable's NTFS
IndexNumber, and the most recent LastWriteTime of all involved binaries
(dlls and main executable). Next to the main.exe hardlink we create the
empty file main.exe.local to enable dll redirection.
The name of the mutex to synchronize hardlink creation/cleanup also is
assembled from these directory names, to allow for synchronized cleanup
of even orphaned hardlink directories.
The hardlink to each dynamically loaded dll goes into another directory,
named using the NTFS IndexNumber of the dll's original directory.
* Makefile.in (DLL_OFILES): Add forkable.o.
* dll_init.h (struct dll): Declare member variables fbi, fii,
forkable_ntname. Declare methods nominate_forkable,
create_forkable.
(struct dll_list): Declare enum forkables_needs. Declare member
variables forkables_dirx_size, forkables_dirx_ntname,
forkables_mutex_name, forkables_mutex. Declare private methods
forkable_ntnamesize, prepare_forkables_nomination,
update_forkables_needs, update_forkables, create_forkables,
denominate_forkables, close_mutex, try_remove_forkables,
set_forkables_inheritance, request_forkables. Declare public
static methods ntopenfile, read_fii, read_fbi. Declare public
methods release_forkables, cleanup_forkables. Define public
inline method setup_forkables.
* dll_init.cc (dll_list::alloc): Allocate memory to hold the
name of the hardlink in struct dll member forkable_ntname.
Initialize struct dll members fbi, fii.
(dll_list::load_after_fork): Call release_forkables method.
* fork.cc: Rename public fork function to static dofork, add
with_forkables as bool pointer parameter. Add new fork function
calling dofork. (struct frok): Add bool pointer member
with_forkables, add as constructor parameter.
(frok::parent): Call dlls.setup_forkables before CreateProcessW,
dlls.release_forkables afterwards.
* pinfo.cc (pinfo::exit): Call dlls.cleanup_forkables.
* syscalls.cc (_unlink_nt): Rename public unlink_nt function to
static _unlink_nt, with 'shareable' as additional argument.
(unlink_nt): New, wrap _unlink_nt for original behaviour.
(unlink_nt_shareable): New, wrap _unlink_nt to keep a binary
file still loadable while removing one of its hardlinks.
* forkable.cc: New file.
Implement static functions mkdirs, rmdirs, rmdirs_synchronized,
stat_real_file_once, format_IndexNumber, rootname, sidname,
exename, lwtimename. Define static array forkable_nameparts.
(struct dll): Implement nominate_forkable, create_forkable.
(struct dll_list): Implement static methods ntopenfile,
read_fii, read_fbi. Implement forkable_ntnamesize,
Trying to delete in-use executables and DLLs using
FILE_DISPOSITION_POSIX_SEMANTICS returns STATUS_CANNOT_DELETE.
Fall back to the former method if that error occurs to allow
unlinking these files.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The symlink target of /proc/PID/fd files pointing to pipes and
sockets are just artificial filenames referencing the object using
some internal number. The pipe open code expects a path specifying
process pid and the internal number so it access the right process
and pipe.
- Set the posix path of the pipe to the simple pipe name only,
as it shows up in /proc/PID/fd. A /proc/self prefix is just
as wrong as a /dev/fd prefix.
- Revert thinko in fhandler_pipe::open expecting the name as
/proc/self/fd/... In fact this should never happen.
- Fix up the path before re-opening the pipe instead.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The reopen code neglected to pass along the requested open
mode correctly. This may end up reopening the file with
incorrect access mask, or duplicating the wrong pipe handle.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- This simple and official method replaces cyglsa and "create token"
methods. No network share access, same as before.
- lsaauth and create_token are disabled now. If problems crop up,
they can be easily reactivated. If no problems crop up, they
can be removed in a while, together with the lsaauth subdir.
- Bump Cygwin version to 3.0.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
While FileRenameInformationEx is defined starting with Windows
10 1709 per MSDN, it only starts working in W10 1809, apparently.
Users of 1803 report "Function not implemented".
Introduce wincap_10_1809 and change the version check in
wincapc::init accordingly. Split has_posix_file_info into
has_posix_unlink_semantics and has_posix_rename_semantics.
Enable the latter only starting with W10 1809.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
So far we check the recycler name all the time, and the last interation
also only managed to handle two ways to write the recycler. However,
an adventurous user might change the case of the recycler arbitrarily.
Fix this problem by keeping track of the name in a somewhat relaxed
fashion. Use camel back on drive C by default, all upper case elsewhere.
Only if the rename op fails do we fix the recycler name on the fly
when trying to create it, and it turns out it already existed.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
If the first rename fails, we reopen the rootdir for creating a subdir.
The rootdir handle can change its value at this point, but the code
doesn't take this into account. The subsequent rename then fails with
STATUS_INVALID_HANDLE. Fix this by copying the new rootdir value to
pfri->RootDirectory.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
So far we reopened the file if it was opened case sensitive to
workaround the problem that the recycler could be named in
camel back or all upper case, depending on who created it.
That's a problem for O_TMPFILE on pre-W10. As soon as the
original HANDLE gets closed, delete-on-close is converted to full
delete disposition and all useful operations on the file cease to
work (STATUS_ACCESS_DENIED or STATUS_FILE_DELETED).
To avoid that problem drop the reopen code and check for the exact
recycler filename, either $Recycle.Bin or $RECYCLE.BIN, if the file
has been opened case sensitive.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
move special fd symlink code into own fhandler_process_fd class
to simplify further additions to /proc/PID/fd/DESCRIPTOR symlink
handling.
Add a method to handle stat(2) on such a proc fd symlink by handle.
This allows correct reply from stat(2) if the target file has been
deleted. This eventually fixes `awk -f /dev/fd/3 3<<eof'.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
path_conv now sets the PATH_RESOLVE_PROCFD flag in path_flags if
the PC_SYM_NOFOLLOW_PROCFD pathconv_arg flag has been set on input
*and* the file is actually a proc fd symlink.
Add matching path_conv::follow_fd_symlink method for checking and
use it in open(2).
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Along the same lines as the previous patch: By reopening an
O_TMPFILE by handle, we can now move the file to the bin at
open time and thus free'ing up the parent dir and *still*
open the file as /proc/PID/fd/DESCRIPTOR by linkat(2).
Allows expressions along the lines of `cat /proc/self/fd/0 <<EOF'.
The problem here is that the temporary file used for the here script
has already been deleted by the shell. Opening by filename, as
implemented so far, doesn't work because the file has been moved
to the bin.
Allow reopening files by handle the same way from another process
as long as we have sufficient permissions on the foreign process.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The commit message of commit 07e0a9584f
and the expectation set therein, are wrong.
There's no POSIX semantics allowing to link a file with a link
count of 0 and making it available in the file system again.
In fact, the Linux linkat extension AT_EMPTY_PATH explicitely
disallows to link a file descriptor to a file with a link count
of 0, except for O_TMPFILE without O_EXCL.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Turns out, the definition of POSIX unlink semantics is half-hearted
so far: It's not possible to link an open file HANDLE if it has
been deleted with POSIX semantics, nor is it possible to remove
the delete disposition. This breaks linkat on an O_TMPFILE.
Tested with W10 1809.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- short-circuit most code in unlink_nt since it's not necessary
anymore if FILE_DISPOSITION_POSIX_SEMANTICS is supported.
- Immediately remove O_TMPFILE from filesystem after creation.
Disable code for now because we have to implement /proc/self/fd
opening by handle first, lest linkat fails.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Difference to Linux: We can't create files which don't show up
in the filesystem due to OS restrictions. As a kludge, make a
(half-hearted) attempt to hide the file in the filesystem.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Also updates the fhandler_*::ftruncate implementations to adhere to the same
semantics. The error handling semantics of those syscalls that use
fhandler_*::ftruncate are moved to the implementations of those syscalls (
in particular ftruncate() and friends still set errno and return -1 on error
but that logic is handled in the syscall implementation).
Under some not quite clear conditions, NFS fails to use its
unlink workaround to rename a file to ".nfsXYZ". The problem has been
reproduced with the GAWK testext.awk testcase. To workaround this in
Cygwin, we now call try_to_bin on NFS, too. For some reason NFS doesn't
fail to rename the .cygXYZ file to .nfsXYZ after this Cygwin rename.
Fix comment in unlink_nt accordingly.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The "final trick" code in try_to_bin accidentally never worked on
remote drives because it relies on rootdir. Which isn't set for
remote unlinks. The code now creates a full path for remote files.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The try_to_bin function isn't called for netapp FSes anyway, so testing
for this FS type in the function is moot.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
If newfile already exists and is in use, trying to overwrite it with
NtSetInformationFile(FileRenameInformation) fails exactly as if we
don't have the permissions to delete it. Unfortunately the return code
is the same STATUS_ACCESS_DENIED, so we have no way to distinguish
these cases. What we do here so far is to start a transaction to delete
newfile. If this open fails with a transactional error we stop the
transaction and retry opening the file without transaction.
But, here's the problem: If newfile is in use, NtOpenFile(oldfile)
naturally does NOT fail with a transactional error. Rather, the
subsequent call to unlink_nt(newfile) does, because there's another
handle open to newfile outside a transaction. However, the code does
not check if unlink_nt fails with a transactional error and so fails
to retry without transaction.
This patch recifies the problem and checks unlink_nt's status as well.
Refactor code to get rid of goto into another code block.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Corinna Vinschen
Michael Haubenwallner
Erik M. Bray
Ken Brown
Sebastian Huber