Using posix timers "timer_tracker" as base class for timerfd was flawed.
Posix timers are not inherited by child processes and don't survive
execve. The method used by posix timers didn't allow to share timers
between processes. The timers were still per-process timers and worked
entirely separate from each other. Reading from these timers via
different descriptors was only synchronized within the same process.
This does not reflect the timerfd semantics in Linux: The per-file
timers can be dup'ed and survive fork and execve. They are still just
descriptors pointing to the same timer object originally created by
timerfd_create. Synchronization is performed between all descriptor
instances of the same timer, system-wide.
Thus, reimplement timerfd using a timer instance in shared memory,
a kernel timer, and a handful of sync objects.
Every process maintains a per-process timerfd struct on the cygheap
maintaining a per-process thread. Every process sharing the same
timerfd will run this thread checking the state of the timer, similar
to the posix timer thread, just working on the shared objects and
synchronizing its job with each other thread.
Drop the timerfd implementation in the posix timer code and move the
public API to fhandler_timerfd.c. Keep the ttstart timer_tracker
anchor out of "NO_COPY" since the fixup_after_fork code should run to
avoid memory leakage.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Linux returns EINVAL, "fd is attached to an object which is unsuitable
for writing". If we don't handle write locally, write returns EBADF.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Puzzeling: Commit ec98d19a08
changed ttstart to NO_COPY but kept all the code to handle
fixup after fork. Revert to not-NO_COPY and make timerfd
fork work.
- On fixup_after_fork, keep timerfd timers and restart thread
if they were armed in the parent.
- Move timerfd timer_trackers to cygheap. Overload timer_tracker
new and delete methods to handle timers accordingly. This is not
exactly required for fork, but exec will be grateful.
- Give up on TFD_TIMER_CANCEL_ON_SET for now. There's no easy way
to recognize a discontinuous change in a clock.
- Be paranoid when cleaning out ttstart.
- Fix some minor issues.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
First cut of a timerfd implementation.
Still TODO:
- fork/exec semantics
- timerfd_settime TFD_TIMER_CANCEL_ON_SET flag
- ioctl(TFD_IOC_SET_TICKS)
- bug fixes
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Allow the signal thread to recognize we're called in consequence of
select on a signalfd. If the signal is part of the wait mask, don't
call any signal handler and don't remove the signal from the queue,
so a subsequent read (or sigwaitinfo/sigtimedwait) still gets the
signal. Instead, just signal the event object at
_cygtls::signalfd_select_wait for the thread running select.
The addition of signalfd_select_wait to _cygtls unearthed the alignment
problem of the context member again. To make sure this doesn't get lost,
improve the related comment in the header file so that this (hopefully)
doesn't get lost (again).
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>
The new proc fd code accidentally allowed to linkat an O_TMPFILE
even if the file has been opened with O_EXCL. This patch fixes it.
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>
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 fhandler_base_overlapped::copyto clears atomic_write_buf on the
clone, but none of the derived classes were doing this. This allowed
the destructor to double-free the buffer and corrupt cygheap.
Clear atomic_write_buf in copyto of all derived classes.
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.)
* fhandler.h (class fhandler_socket_inet): Add variable bool oobinline.
* fhandler_socket_inet.cc (fhandler_socket_inet::fhandler_socket_inet):
Initialize variable oobinline.
(fhandler_socket_inet::recv_internal): Make the handling of OOB data
as consistent with POSIX as possible. Add simulation of inline mode
for OOB data as a workaround for broken winsock behavior.
(fhandler_socket_inet::setsockopt): Ditto.
(fhandler_socket_inet::getsockopt): Ditto.
(fhandler_socket_wsock::ioctl): Fix return value of SIOCATMARK command.
The return value of SIOCATMARK of winsock is almost opposite to
expectation.
* fhandler_socket_local.cc (fhandler_socket_local::recv_internal):
Remove the handling of OOB data from AF_LOCAL domain socket. Operation
related to OOB data will result in an error like Linux does.
(fhandler_socket_local::sendto): Ditto.
(fhandler_socket_local::sendmsg): Ditto.
This fixes the issue reported in following post.
https://cygwin.com/ml/cygwin/2018-06/msg00143.html
* Change set_socket_type/get_socket_type to virtual methods
* Move various variables into af_unix_shmem_t
* Change sun_name_t to match new usage pattern
* Move shut_state definition and add a name for the 0 value
* Allow marking packet as administrative packet. This allows
filtering out info packets exchange between peers and tweak
data accordingly.
* Rename send_my_name to send_sock_info and send credentials
if not called from bind (so the socket was already connected)
* Handle SO_PASSCRED in setsockopt/getsockopt
* Add input size checking to setsockopt/getsockopt
* Use NT functions where appropriate
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
We need to share socket info between threads *and* processes.
SRWLOCKs are single-process only, unfortunately. Provide a
sharable low-profile spinlock instead.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
E.g. arm ABI requires -fshort-enums for bare-metal toolchains.
Given there are only 29 category enums, the compiler chooses an
8 bit enum type, so a size of 11 bits for the bitfield leads to
a compile time error:
error: width of 'cat' exceeds its type
enum category cat: 11;
^~~
Fix this by aligning the size of the category members to byte
borders.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Per-socket info in fhandler isn't correctly shared between multiple
instances of th same descriptor. Implement a basic shared info which
is shared between all instances of a socket.
This also requires to move the fhandler_socket status bits into
fhandler_socket_wsock since the data is moved to the shared region
for AF_UNIX sockets.
Also, drop backing file requirement for socketpair server socket.
This will be handled differently in recvmsg/sendmsg.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Using TerminateThread potentially leaks resources. In our case,
the connect wait thread may be forcefully terminated after
having successfully opened a client side pipe handle. If this
occurs, we have a stale pipe server instance, so the pipe will
never be closed as long as the process lives.
Avoid this by changing the npfs handle to non-blocking, so we can
wait on a termination event object from inside the thread itself
and cleanly exit from the thread instead of terminating.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The handle to the device is never needed. As the name impies,
FSCTL_PIPE_WAIT works on the file system, not on the device level.
Drop opening the device and make sure to open only one handle to NPFS.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
They are only used there anyway and it allows to use the AF_UNIX
macro without tweaking header files. While at it, improve
both constructors. The default constructor now creates the name
of an unnamed socket, the constructor taking parameters carefully
checks its input.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
...plus lots of helper functions. Add comment to explain how everything
works. This comment will be improved while implementing the yet missing
parts.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Add constructors and new/delete operators to make sure sun_name_t
objects are allocated on the cygheap.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
fhandler_cygdrive has a size of 696 bytes on x86_64, while the next
biggest fhandler type, fhandler_pty_master, is 584 bytes. The members
responsible for the size are private to opendir/readdir/closedir usage.
fhandler_disk_file stores private readdir data in DIR->__d_internal
instead. Use equivalent method with fhandler_cygdrive. This drops
the size to 464 bytes.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* Make distinct from AF_LOCAL for testing purposes. This will have
to be reverted as soon as fhandler_socket_unix goes life.
* Move saw_reuseaddr flag back to fhandler_socket status
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
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>
Corinna Vinschen
Ken Brown
David McFarland
Mark Geisert
Takashi Yano