newlib-cygwin/winsup/cygwin/fhandler_fifo.cc

178 lines
3.9 KiB
C++

/* fhandler_fifo.cc - See fhandler.h for a description of the fhandler classes.
Copyright 2002, 2003, 2004, 2005, 2006, 2007 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 <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/statvfs.h>
#include "cygerrno.h"
#include "perprocess.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "pinfo.h"
#include "sigproc.h"
#include "cygtls.h"
fhandler_fifo::fhandler_fifo ():
wait_state (fifo_unknown)
{
get_overlapped ()->hEvent = NULL;
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)
low_priority_sleep (0);
else if (WaitForSingleObject (signal_arrived, 0) == WAIT_OBJECT_0)
{
set_errno (EINTR);
return NULL;
}
}
}
#define FIFO_PIPE_MODE (PIPE_TYPE_BYTE | PIPE_READMODE_BYTE)
int
fhandler_fifo::open (int flags, mode_t)
{
int res;
char npname[CYG_MAX_PATH];
DWORD mode = 0;
/* Generate a semi-unique name to associate with this fifo.
FIXME: Probably should use "inode" and "dev" from stat for this. */
__small_sprintf (npname, "\\\\.\\pipe\\__cygfifo__%lx", get_namehash ());
unsigned low_flags = flags & O_ACCMODE;
if (low_flags == O_RDONLY)
mode = PIPE_ACCESS_INBOUND;
else if (low_flags == O_WRONLY)
mode = PIPE_ACCESS_OUTBOUND;
else if (low_flags == O_RDWR)
mode = PIPE_ACCESS_DUPLEX;
if (!mode)
{
set_errno (EINVAL);
res = 0;
}
else
{
char char_sa_buf[1024];
LPSECURITY_ATTRIBUTES sa_buf =
sec_user ((PSECURITY_ATTRIBUTES) char_sa_buf, cygheap->user.sid());
mode |= FILE_FLAG_OVERLAPPED;
HANDLE h = CreateNamedPipe(npname, mode, FIFO_PIPE_MODE,
PIPE_UNLIMITED_INSTANCES, 0, 0,
NMPWAIT_WAIT_FOREVER, sa_buf);
if (h != INVALID_HANDLE_VALUE)
wait_state = fifo_wait_for_client;
else
switch (GetLastError ())
{
case ERROR_ACCESS_DENIED:
h = open_nonserver (npname, low_flags, sa_buf);
if (h != INVALID_HANDLE_VALUE)
{
wait_state = fifo_wait_for_server;
break;
}
/* fall through intentionally */
default:
__seterrno ();
break;
}
if (!h || h == INVALID_HANDLE_VALUE)
res = 0;
else if (!setup_overlapped ())
{
__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)
{
switch (wait_state)
{
case fifo_wait_for_client:
bool res = ConnectNamedPipe (get_handle (), get_overlapped ());
if (res || GetLastError () == ERROR_PIPE_CONNECTED)
return true;
return wait_overlapped (res, iswrite);
default:
break;
}
return true;
}
void
fhandler_fifo::read (void *in_ptr, size_t& len)
{
if (!wait (false))
len = 0;
else
read_overlapped (in_ptr, len);
}
int
fhandler_fifo::write (const void *ptr, size_t len)
{
return wait (true) ? write_overlapped (ptr, len) : -1;
}
int __stdcall
fhandler_fifo::fstatvfs (struct statvfs *sfs)
{
/* Call statvfs on parent dir. */
char *c, dir[CYG_MAX_PATH];
strcpy (dir, get_name ());
if ((c = strrchr (dir, '/')))
{
*c = '\0';
return statvfs (dir, sfs);
}
set_errno (EBADF);
return -1;
}