This reverts commit 0390cc8572.
There's no indication what exact situation this patch was supposed to
solve, and local testing doesn't show any such problems. However, this
patch itself introduced a new problem, as outlined by
https://cygwin.com/pipermail/cygwin/2022-January/250629.html
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The file attributes after creating a file are not necessarily
identical to the attributes we passed as argument to NtCreateFile.
This results in subsequent operations like fchmod or facl to
set the DOS file attributes to unexpected values.
The fix is to request file attributes from the OS after file creation
and cache those.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Cygwin always requests FILE_WRITE_ATTRIBUTES permissions when trying to
change DAC information. This can lead to permission problems when
trying to chmod/chown files on Samba shares. Drop requesting
FILE_WRITE_ATTRIBUTES on Samba shares and go with WRITE_DAC/WRITE_OWNER
only.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
open_setup is called by dtable::init_std_file_from_handle and
fhandler_base::open_with_arch. In both cases, failure of open_setup
is now a fatal error.
Currently this can only happen in the following situation: A Cygwin
process is started by a non-Cygwin process, one of the standard IO
handles is a pipe handle, and Cygwin is unable to create a required
mutex (read_mtx or hdl_cnt_mtx).
Analyzing the fhandler::copyto logic shows that the fhandler_base::reset
method was only called from copyto anyway.
Trying to convert reset to a protected method uncovered that the copyto
method is actually thought upside down from an object oriented POV.
Rather than calling copyto, manipulating the object given as parameter,
rename the method to copy_from, which manipulates the calling object
itself with data from the object given as parameter.
Eventually make reset a protected method and rename it to
_copy_from_reset_helper to clarify it's only called from copy_from.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
There's a slim chance that duplicating fhandlers may end up duplicating
path_conv_handle handles twice ending up with a handle leak, due to
fhandler_base::reset calling path_conv::operator<< after the only
caller, fhandler::copyto, already called path_conv::operator=.
Just drop the call which basically duplicates what path_conv::operator=
already did.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The following Windows system calls currently fail with
STATUS_IO_REPARSE_TAG_NOT_HANDLED when called on an AF_UNIX socket:
- NtOpenFile in get_file_sd
- NtOpenFile in set_file_sd
- NtCreateFile in fhandler_base::open
Fix this by adding the FILE_OPEN_REPARSE_POINT flag to those calls
when the file is a known reparse point.
This patch has been inspired by the Linux kernel patch
294f69e662d1 compiler_attributes.h: Add 'fallthrough' pseudo keyword for switch/case use
written by Joe Perches <joe AT perches DOT com> based on an idea from
Dan Carpenter <dan DOT carpenter AT oracle DOT com>. The following text
is from the original log message:
Reserve the pseudo keyword 'fallthrough' for the ability to convert the
various case block /* fallthrough */ style comments to appear to be an
actual reserved word with the same gcc case block missing fallthrough
warning capability.
All switch/case blocks now should end in one of:
break;
fallthrough;
goto <label>;
return [expression];
continue;
In C mode, GCC supports the __fallthrough__ attribute since 7.1,
the same time the warning and the comment parsing were introduced.
Cygwin-only: add an explicit -Wimplicit-fallthrough=5 to the build
flags.
The return type of fhandler write methods is ssize_t. Don't
use an int to store the return value, use ssize_t. Use ptrdiff_t
for the buffer size.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- The cause of the problem reported in
https://www.cygwin.com/ml/cygwin/2020-01/msg00220.html is that the
chars input before dup() cannot be read from the new file descriptor.
This is because the readahead buffer (rabuf) in the console is newly
created by dup(), and does not inherit from the parent. This patch
fixes the issue.
If O_PATH is set in the flags argument of
fhandler_base::device_access_denied, return false. No
read/write/execute access should be required in this case.
Previously, the call to device_access_denied in open(2) would lead to
an attempt to open the file with read access even if the O_PATH flag
was set.
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>
First cut of a signalfd implementation.
Still TODO: Non-polling select.
This should mostly work as on Linux except for missing support
for some members of struct signalfd_siginfo, namely ssi_fd,
ssi_band (both SIGIO/SIGPOLL, not fully implemented) and ssi_trapno
(HW exception, required HW support).
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
On pre-W10 systems there's no way to reopen a file by handle if
the delete disposition is set. We try to get around with
duplicating the handle.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
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>
So far io_handle is NULL when calling fhandler_base::open to
open or create a file. Add a check for io_handle to allow
priming the fhandler with a HANDLE value so we can reopen a
file from a HANDLE on file systems supporting it. This allows
to open already deleted files for further action. This will
be used by open("/proc/PID/fd/DESCRIPTOR") scenarios.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This code is where the AIO implementation is wired into existing Cygwin
mechanisms for file and device I/O: the fhandler* functions. It makes
use of an existing internal routine prw_open to supply a "shadow fd"
that permits asynchronous operations on a file the user app accesses
via its own fd. This allows AIO to read or write at arbitrary locations
within a file without disturbing the app's file pointer. (This was
already the case with normal pread|pwrite; we're just adding "async"
to the mix.)
Insert another class fhandler_socket_wsock between fhandler_socket
and fhandler_socket_inet/fhandler_socket_local.
Also, add a new method fhandler::is_wsock_socket to allow asking
for sockets in general (is_socket) vs. Winsock-based sockets
(is_wsock_socket).
This allows to develop a new handler_socket_unix class as derived
class from fhandler_socket without any trace of wsock code left
in fhandler_socket.
While this is basically a temporary measure at this time, it may
prove useful for later interoperability with the upcoming Windows 10
AF_UNIX implementation at one point.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Windows does not remove FILE_ATTRIBUTE_TEMPORARY by itself after a
file has been closed. It's just some attribute which can be set or
removed at will, despite its purpose.
Apparently there are tools out there which use FILE_ATTRIBUTE_TEMPORARY
accidentally or wrongly, even Microsoft's own tools are affected. In
the end, the filesystem is potentially full of files with this attribute
set.
Implement O_TMPFILE files with FILE_ATTRIBUTE_TEMPORARY and
FILE_ATTRIBUTE_HIDDEN set. This combination is pretty unlikely.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Commit 603ef545bd broke this snippet and
commit 5b312b4747 didn't help at all since
FILE_CREATE is exactly *not* the situation the test was originally
supposed to handle.
In fact, none of the open flags used by fhandler_base::open actually
hits this problem anymore, so just drop the code.
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).
Windows NUL device returns only the lower 32 bit of the number of
bytes written. Implement a fake write function to ignore the underlying
NUL device.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The termios code doesn't handle erasing of multibyte characters
in canonical mode, it always erases a single byte. When entering
a multibyte character and then pressing VERASE, the input ends up
with an invalid character.
Following Linux we introduce the IUTF8 input flag now, set by
default. When this flag is set, VERASE or VWERASE will check
if the just erased input byte is a UTF-8 continuation byte. If
so, it erases another byte and checks again until the entire
UTF-8 character has been removed from the input buffer.
Note that this (just as on Linux) does NOT work with arbitrary
multibyte codesets. This only works with UTF-8.
For a discussion what happens, see
https://cygwin.com/ml/cygwin/2017-01/msg00299.html
Sidenote: The eat_readahead function is now member of fhandler_termios,
not fhandler_base. That's necessary to get access to the terminal's
termios flags.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This patch fixes the following problem:
Commit 9636c426 refactored the pipe code especially to make sure
to call WriteFile only with chunks matching the maximum atomic write
count. This accidentally introduced a small change in behaviour
on blocking pipes due to the success case falling through into the
error case. Rather then writing atomic chunks until all bytes are
written, the code immediately broke from the loop after writing
the first chunk, basically the same as in case of non-blocking
writes. This behaviour is not compliant to POSIX which requires
"Write requests to a pipe or FIFO [...]
* If the O_NONBLOCK flag is clear, a write request may cause the
thread to block, but on normal completion it shall return nbyte."
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Update the getconf utility to support the new flag as well as
_PC_POSIX_PERMISSIONS and _PC_POSIX_SECURITY. These were previously
unsupported, probably as an oversight.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Revamp device parsing code. Introducing support for more partitions
into the shilka-generated parser has the unfortunate side-effect of
raising the size of the DLL by almost 2 Megs. Therefore we split out
the handling for /dev/sdXY devices into a tiny bit of hand-written
code.
While at it, remove some unused cruft from devices.* and generally
clean up the device class to provide access methods instead of direct
access to members.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Bump GPLv2+ to GPLv3+ for some files, clarify BSD 2-clause.
Everything else stays under GPLv3+.
New Linking Exception exempts resulting executables from LGPLv3 section 4.
Add CONTRIBUTORS file to keep track of licensing.
Remove 'Copyright Red Hat Inc' comments.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Corinna Vinschen
Takashi Yano
Ken Brown
Yaakov Selkowitz
Mark Geisert
Erik M. Bray