newlib/winsup/cygwin/fhandler_fifo.cc

335 lines
7.6 KiB
C++

/* fhandler_fifo.cc - See fhandler.h for a description of the fhandler classes.
Copyright 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include "miscfuncs.h"
#include "cygerrno.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "sigproc.h"
#include "cygtls.h"
#include "shared_info.h"
fhandler_fifo::fhandler_fifo ():
fhandler_base_overlapped (), wait_state (fifo_unknown), dummy_client (NULL)
{
max_atomic_write = DEFAULT_PIPEBUFSIZE;
need_fork_fixup (true);
}
HANDLE
fhandler_fifo::open_nonserver (const char *npname, unsigned low_flags,
LPSECURITY_ATTRIBUTES sa_buf)
{
DWORD mode = 0;
if (low_flags == O_RDONLY)
mode = GENERIC_READ;
else if (low_flags == O_WRONLY)
mode = GENERIC_WRITE;
else
mode = GENERIC_READ | GENERIC_WRITE;
while (1)
{
HANDLE h = CreateFile (npname, mode, 0, sa_buf, OPEN_EXISTING,
FILE_FLAG_OVERLAPPED, NULL);
if (h != INVALID_HANDLE_VALUE || GetLastError () != ERROR_PIPE_NOT_CONNECTED)
return h;
if (&_my_tls != _main_tls)
yield ();
else if (WaitForSingleObject (signal_arrived, 0) == WAIT_OBJECT_0)
{
set_errno (EINTR);
return NULL;
}
}
}
char *
fhandler_fifo::fifo_name (char *buf)
{
/* Generate a semi-unique name to associate with this fifo. */
__small_sprintf (buf, "\\\\.\\pipe\\__cygfifo__%S_%08x_%016X",
&installation_key, get_dev (), get_ino ());
return buf;
}
#define FIFO_PIPE_MODE (PIPE_TYPE_BYTE | PIPE_READMODE_BYTE)
#define FIFO_BUF_SIZE 4096
#define cnp(m, s) CreateNamedPipe(npname, (m), FIFO_PIPE_MODE, \
PIPE_UNLIMITED_INSTANCES, (s), (s), \
NMPWAIT_WAIT_FOREVER, sa_buf)
inline PSECURITY_ATTRIBUTES
sec_user_cloexec (bool cloexec, PSECURITY_ATTRIBUTES sa, PSID sid)
{
return cloexec ? sec_user_nih (sa, sid) : sec_user (sa, sid);
}
int
fhandler_fifo::open (int flags, mode_t)
{
int res = 1;
char npname[MAX_PATH];
fifo_name (npname);
unsigned low_flags = flags & O_ACCMODE;
DWORD mode = 0;
if (low_flags == O_WRONLY)
mode = PIPE_ACCESS_OUTBOUND;
else if (low_flags == O_RDONLY || low_flags == O_RDWR)
mode = PIPE_ACCESS_DUPLEX;
else
{
set_errno (EINVAL);
res = 0;
}
if (res)
{
char char_sa_buf[1024];
LPSECURITY_ATTRIBUTES sa_buf =
sec_user_cloexec (flags & O_CLOEXEC, (PSECURITY_ATTRIBUTES) char_sa_buf,
cygheap->user.sid());
bool do_seterrno = true;
HANDLE h;
bool nonblocking_write = !!((flags & (O_WRONLY | O_NONBLOCK)) == (O_WRONLY | O_NONBLOCK));
wait_state = fifo_unknown;
if (mode != PIPE_ACCESS_OUTBOUND)
{
h = cnp (mode | FILE_FLAG_OVERLAPPED, FIFO_BUF_SIZE);
wait_state = fifo_wait_for_client;
}
else
{
h = open_nonserver (npname, low_flags, sa_buf);
if (h != INVALID_HANDLE_VALUE)
wait_state = fifo_ok;
else if (nonblocking_write)
{
set_errno (ENXIO);
do_seterrno = false;
}
else if ((h = cnp (PIPE_ACCESS_DUPLEX, 1)) != INVALID_HANDLE_VALUE)
{
if ((dummy_client = open_nonserver (npname, low_flags, sa_buf))
!= INVALID_HANDLE_VALUE)
{
wait_state = fifo_wait_for_server;
ProtectHandle (dummy_client);
}
else
{
DWORD saveerr = GetLastError ();
CloseHandle (h);
h = INVALID_HANDLE_VALUE;
SetLastError (saveerr);
}
}
}
if (h == INVALID_HANDLE_VALUE)
{
if (do_seterrno)
__seterrno ();
res = 0;
}
else if (setup_overlapped ())
{
CloseHandle (h);
__seterrno ();
res = 0;
}
else
{
set_io_handle (h);
set_flags (flags);
res = 1;
}
}
debug_printf ("returning %d, errno %d", res, get_errno ());
return res;
}
bool
fhandler_fifo::wait (bool iswrite)
{
DWORD ninstances;
switch (wait_state)
{
case fifo_wait_for_next_client:
DisconnectNamedPipe (get_handle ());
if (!GetNamedPipeHandleState (get_handle (), NULL, &ninstances, NULL, NULL, NULL, 0))
{
__seterrno ();
wait_state = fifo_error;
return false;
}
if (ninstances <= 1)
{
wait_state = fifo_eof;
return false;
}
case fifo_wait_for_client:
{
DWORD dummy_bytes;
while (1)
{
int res = ConnectNamedPipe (get_handle (), get_overlapped ());
if (GetLastError () != ERROR_NO_DATA && GetLastError () != ERROR_PIPE_CONNECTED)
{
res = wait_overlapped (res, iswrite, &dummy_bytes, false);
if (!res)
{
if (get_errno () != EINTR)
wait_state = fifo_error;
else if (!_my_tls.call_signal_handler ())
wait_state = fifo_eintr;
else
continue;
return false;
}
}
wait_state = fifo_ok;
break;
}
}
break;
case fifo_wait_for_server:
char npname[MAX_PATH];
fifo_name (npname);
char char_sa_buf[1024];
LPSECURITY_ATTRIBUTES sa_buf;
sa_buf = sec_user_cloexec (close_on_exec (),
(PSECURITY_ATTRIBUTES) char_sa_buf,
cygheap->user.sid());
while (1)
{
if (WaitNamedPipe (npname, 10))
/* connected, maybe */;
else if (GetLastError () != ERROR_SEM_TIMEOUT)
{
__seterrno ();
return false;
}
else if (WaitForSingleObject (signal_arrived, 0) != WAIT_OBJECT_0)
continue;
else if (_my_tls.call_signal_handler ())
continue;
else
{
set_errno (EINTR);
return false;
}
HANDLE h = open_nonserver (npname, get_flags () & O_ACCMODE, sa_buf);
if (h != INVALID_HANDLE_VALUE)
{
ForceCloseHandle (get_handle ());
ForceCloseHandle (dummy_client);
dummy_client = NULL;
wait_state = fifo_ok;
set_io_handle (h);
break;
}
if (GetLastError () == ERROR_PIPE_LISTENING)
continue;
else
{
__seterrno ();
return false;
}
}
default:
break;
}
return true;
}
void __stdcall
fhandler_fifo::raw_read (void *in_ptr, size_t& len)
{
while (wait_state != fifo_eof && wait_state != fifo_error && wait_state != fifo_eintr)
if (!wait (false))
len = (wait_state == fifo_error || wait_state == fifo_eintr) ? (size_t) -1 : 0;
else
{
size_t prev_len = len;
read_overlapped (in_ptr, len);
if (len)
break;
wait_state = fifo_wait_for_next_client;
len = prev_len;
}
if (wait_state == fifo_eintr)
wait_state = fifo_wait_for_client;
debug_printf ("returning %d, mode %d, %E\n", len, get_errno ());
}
ssize_t __stdcall
fhandler_fifo::raw_write (const void *ptr, size_t len)
{
return wait (true) ? write_overlapped (ptr, len) : -1;
}
int __stdcall
fhandler_fifo::fstatvfs (struct statvfs *sfs)
{
fhandler_disk_file fh (pc);
fh.get_device () = FH_FS;
return fh.fstatvfs (sfs);
}
int
fhandler_fifo::close ()
{
wait_state = fifo_eof;
if (dummy_client)
{
ForceCloseHandle (dummy_client);
dummy_client = NULL;
}
return fhandler_base::close ();
}
int
fhandler_fifo::dup (fhandler_base *child)
{
int res = fhandler_base_overlapped::dup (child);
fhandler_fifo *fifo_child = (fhandler_fifo *) child;
if (res == 0 && dummy_client)
{
bool dres = DuplicateHandle (GetCurrentProcess (), dummy_client,
GetCurrentProcess (),
&fifo_child->dummy_client, 0,
TRUE, DUPLICATE_SAME_ACCESS);
if (!dres)
{
fifo_child->dummy_client = NULL;
child->close ();
__seterrno ();
res = -1;
}
}
return res;
}
void
fhandler_fifo::set_close_on_exec (bool val)
{
fhandler_base::set_close_on_exec (val);
if (dummy_client)
set_no_inheritance (dummy_client, val);
}