newlib-cygwin/winsup/cygwin/syscalls.cc

/* syscalls.cc: syscalls

   Copyright 1996, 1997, 1998, 1999, 2000 Cygnus Solutions.

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 <sys/stat.h>
#include <sys/vfs.h> /* needed for statfs */
#include <fcntl.h>
#include <pwd.h>
#include <grp.h>
#include <stdlib.h>
#include <stdio.h>
#include <process.h>
#include <utmp.h>
#include <sys/uio.h>
#include <errno.h>
#include <limits.h>
#include <winnls.h>
#include <lmcons.h> /* for UNLEN */
#include <cygwin/version.h>
#include <sys/cygwin.h>
#include "cygerrno.h"
#include "fhandler.h"
#include "path.h"
#include "dtable.h"
#include "sync.h"
#include "sigproc.h"
#include "pinfo.h"
#include <unistd.h>
#include "shared_info.h"
#include "perprocess.h"
#include "security.h"
#include "cygheap.h"

/* Close all files and process any queued deletions.
   Lots of unix style applications will open a tmp file, unlink it,
   but never call close.  This function is called by _exit to
   ensure we don't leave any such files lying around.  */

void __stdcall
close_all_files (void)
{
  SetResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK," close");

  fhandler_base *fh;
  for (int i = 0; i < (int) fdtab.size; i++)
    if ((fh = fdtab[i]) != NULL)
      {
	fh->close ();
	fdtab.release (i);
      }

  ReleaseResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK," close");
  cygwin_shared->delqueue.process_queue ();
}

extern "C" int
_unlink (const char *ourname)
{
  int res = -1;
  sigframe thisframe (mainthread);

  path_conv win32_name (ourname, PC_SYM_NOFOLLOW | PC_FULL);

  if (win32_name.error)
    {
      set_errno (win32_name.error);
      goto done;
    }

  syscall_printf ("_unlink (%s)", win32_name.get_win32 ());

  DWORD atts;
  atts = win32_name.file_attributes ();
  if (atts != 0xffffffff && atts & FILE_ATTRIBUTE_DIRECTORY)
    {
      syscall_printf ("unlinking a directory");
      set_errno (EPERM);
      goto done;
    }

  /* Windows won't check the directory mode, so we do that ourselves.  */
  if (!writable_directory (win32_name))
    {
      syscall_printf ("non-writable directory");
      goto done;
    }

  for (int i = 0; i < 2; i++)
    {
      if (DeleteFile (win32_name))
	{
	  syscall_printf ("DeleteFile succeeded");
	  res = 0;
	  break;
	}

      DWORD lasterr;
      lasterr = GetLastError ();

      /* FIXME: There's a race here. */
      HANDLE h = CreateFile (win32_name, GENERIC_READ,
			    FILE_SHARE_READ,
			    &sec_none_nih, OPEN_EXISTING,
			    FILE_FLAG_DELETE_ON_CLOSE, 0);
      if (h != INVALID_HANDLE_VALUE)
	{
	  CloseHandle (h);
	  syscall_printf ("CreateFile/CloseHandle succeeded");
	  if (os_being_run == winNT || GetFileAttributes (win32_name) == (DWORD) -1)
	    {
	      res = 0;
	      break;
	    }
	}

      if (i > 0)
	{
	  DWORD dtype;
	  if (os_being_run == winNT || lasterr != ERROR_ACCESS_DENIED)
	    goto err;

	  char root[MAX_PATH];
	  strcpy (root, win32_name);
	  dtype = GetDriveType (rootdir (root));
	  if (dtype & DRIVE_REMOTE)
	    {
	      syscall_printf ("access denied on remote drive");
	      goto err;  /* Can't detect this, unfortunately */
	    }
	  lasterr = ERROR_SHARING_VIOLATION;
	}

      syscall_printf ("i %d, couldn't delete file, %E", i);

      /* If we get ERROR_SHARING_VIOLATION, the file may still be open -
	 Windows NT doesn't support deleting a file while it's open.  */
      if (lasterr == ERROR_SHARING_VIOLATION)
	{
	  cygwin_shared->delqueue.queue_file (win32_name);
	  res = 0;
	  break;
	}

      /* if access denied, chmod to be writable in case it is not
	 and try again */
      /* FIXME: Should check whether ourname is directory or file
	 and only try again if permissions are not sufficient */
      if (lasterr == ERROR_ACCESS_DENIED && chmod (win32_name, 0777) == 0)
	continue;

    err:
      __seterrno ();
      res = -1;
      break;
    }

done:
  syscall_printf ("%d = unlink (%s)", res, ourname);
  return res;
}

extern "C" int
remove (const char *ourname)
{
  path_conv win32_name (ourname, PC_SYM_NOFOLLOW | PC_FULL);

  if (win32_name.error)
    {
      set_errno (win32_name.error);
      syscall_printf ("-1 = remove (%s)", ourname);
      return -1;
    }

  DWORD atts = win32_name.file_attributes ();
  if (atts != 0xffffffff && atts & FILE_ATTRIBUTE_DIRECTORY)
    return rmdir (ourname);

  return _unlink (ourname);
}

extern "C" pid_t
_getpid ()
{
  return myself->pid;
}

/* getppid: POSIX 4.1.1.1 */
extern "C" pid_t
getppid ()
{
  return myself->ppid;
}

/* setsid: POSIX 4.3.2.1 */
extern "C" pid_t
setsid (void)
{
  /* FIXME: for now */
  if (myself->pgid != _getpid ())
    {
      myself->ctty = -1;
      myself->sid = _getpid ();
      myself->pgid = _getpid ();
      syscall_printf ("sid %d, pgid %d, ctty %d", myself->sid, myself->pgid, myself->ctty);
      return myself->sid;
    }
  set_errno (EPERM);
  return -1;
}

extern "C" int
_read (int fd, void *ptr, size_t len)
{
  sigframe thisframe (mainthread);
  extern int sigcatchers;
  if (fdtab.not_open (fd))
    {
      set_errno (EBADF);
      return -1;
    }

  // set_sig_errno (0);
  fhandler_base *fh = fdtab[fd];
  DWORD wait = (fh->get_flags () & (O_NONBLOCK | OLD_O_NDELAY)) ? 0 : INFINITE;

  /* Could block, so let user know we at least got here.  */
  syscall_printf ("read (%d, %p, %d) %sblocking, sigcatchers %d", fd, ptr, len, wait ? "" : "non", sigcatchers);

  int res;
  if (wait && (!sigcatchers || !fh->is_slow () || fh->get_r_no_interrupt ()))
    debug_printf ("non-interruptible read\n");
  else if (!fh->ready_for_read (fd, wait, 0))
    {
      if (!wait)
	set_sig_errno (EAGAIN);	/* Don't really need 'set_sig_errno' here, but... */
      else
	set_sig_errno (EINTR);
      res = -1;
      goto out;
    }

  /* Check to see if this is a background read from a "tty",
     sending a SIGTTIN, if appropriate */
  res = fh->bg_check (SIGTTIN);
  if (res > 0)
    {
      myself->process_state |= PID_TTYIN;
      res = fh->read (ptr, len);
      myself->process_state &= ~PID_TTYIN;
    }

out:
  syscall_printf ("%d = read (%d<%s>, %p, %d), errno %d", res, fd, fh->get_name (),
		  ptr, len, get_errno ());
  MALLOC_CHECK;
  return res;
}

extern "C" int
_write (int fd, const void *ptr, size_t len)
{
  int res = -1;
  sigframe thisframe (mainthread);

  if (fdtab.not_open (fd))
    {
      set_errno (EBADF);
      goto done;
    }

  /* Could block, so let user know we at least got here.  */
  if (fd == 1 || fd == 2)
    paranoid_printf ("write (%d, %p, %d)", fd, ptr, len);
  else
    syscall_printf  ("write (%d, %p, %d)", fd, ptr, len);

  fhandler_base *fh;
  fh = fdtab[fd];

  res = fh->bg_check (SIGTTOU);
  if (res > 0)
    {
      myself->process_state |= PID_TTYOU;
      res = fh->write (ptr, len);
      myself->process_state &= ~PID_TTYOU;
    }

done:
  if (fd == 1 || fd == 2)
    paranoid_printf ("%d = write (%d, %p, %d)", res, fd, ptr, len);
  else
    syscall_printf ("%d = write (%d, %p, %d)", res, fd, ptr, len);

  MALLOC_CHECK;
  return (ssize_t)res;
}

/*
 * FIXME - should really move this interface into fhandler, and implement
 * write in terms of it. There are devices in Win32 that could do this with
 * overlapped I/O much more efficiently - we should eventually use
 * these.
 */

extern "C" ssize_t
writev (int fd, const struct iovec *iov, int iovcnt)
{
  int i;
  ssize_t len, total;
  char *base;

  if (iovcnt < 1 || iovcnt > IOV_MAX)
    {
      set_errno (EINVAL);
      return -1;
    }

  /* Ensure that the sum of the iov_len values is less than
     SSIZE_MAX (per spec), if so, we must fail with no output (per spec).
  */
  total = 0;
  for (i = 0; i < iovcnt; ++i)
    {
    total += iov[i].iov_len;
    if (total > SSIZE_MAX)
      {
      set_errno (EINVAL);
      return -1;
      }
    }
  /* Now write the data */
  for (i = 0, total = 0; i < iovcnt; i++, iov++)
    {
      len = iov->iov_len;
      base = iov->iov_base;
      while (len > 0)
	{
	  register int nbytes;
	  nbytes = write (fd, base, len);
	  if (nbytes < 0 && total == 0)
	    return -1;
	  if (nbytes <= 0)
	    return total;
	  len -= nbytes;
	  total += nbytes;
	  base += nbytes;
	}
    }
  return total;
}

/*
 * FIXME - should really move this interface into fhandler, and implement
 * read in terms of it. There are devices in Win32 that could do this with
 * overlapped I/O much more efficiently - we should eventually use
 * these.
 */

extern "C" ssize_t
readv (int fd, const struct iovec *iov, int iovcnt)
{
  int i;
  ssize_t len, total;
  char *base;

  for (i = 0, total = 0; i < iovcnt; i++, iov++)
    {
      len = iov->iov_len;
      base = iov->iov_base;
      while (len > 0)
	{
	  register int nbytes;
	  nbytes = read (fd, base, len);
	  if (nbytes < 0 && total == 0)
	    return -1;
	  if (nbytes <= 0)
	    return total;
	  len -= nbytes;
	  total += nbytes;
	  base += nbytes;
	}
    }
  return total;
}

/* _open */
/* newlib's fcntl.h defines _open as taking variable args so we must
   correspond.  The third arg if it exists is: mode_t mode. */
extern "C" int
_open (const char *unix_path, int flags, ...)
{
  int fd;
  int res = -1;
  va_list ap;
  mode_t mode = 0;
  fhandler_base *fh;
  sigframe thisframe (mainthread);

  syscall_printf ("open (%s, %p)", unix_path, flags);
  if (!check_null_empty_path_errno(unix_path))
    {
      SetResourceLock(LOCK_FD_LIST, WRITE_LOCK|READ_LOCK, " open ");

      /* check for optional mode argument */
      va_start (ap, flags);
      mode = va_arg (ap, mode_t);
      va_end (ap);

      fd = fdtab.find_unused_handle ();

      if (fd < 0)
	set_errno (ENMFILE);
      else if ((fh = fdtab.build_fhandler (fd, unix_path, NULL)) == NULL)
	res = -1;		// errno already set
      else if (!fh->open (unix_path, flags, (mode & 0777) & ~cygheap->umask))
	{
	  fdtab.release (fd);
	  res = -1;
	}
      else if ((res = fd) <= 2)
	set_std_handle (res);
      ReleaseResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK," open");
    }

  syscall_printf ("%d = open (%s, %p)", res, unix_path, flags);
  return res;
}

extern "C" off_t
_lseek (int fd, off_t pos, int dir)
{
  off_t res;
  sigframe thisframe (mainthread);

  if (fdtab.not_open (fd))
    {
      set_errno (EBADF);
      res = -1;
    }
  else
    {
      res = fdtab[fd]->lseek (pos, dir);
    }
  syscall_printf ("%d = lseek (%d, %d, %d)", res, fd, pos, dir);

  return res;
}

extern "C" int
_close (int fd)
{
  int res;
  sigframe thisframe (mainthread);

  syscall_printf ("close (%d)", fd);

  MALLOC_CHECK;
  if (fdtab.not_open (fd))
    {
      debug_printf ("handle %d not open", fd);
      set_errno (EBADF);
      res = -1;
    }
  else
    {
      SetResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK," close");
      res = fdtab[fd]->close ();
      fdtab.release (fd);
      ReleaseResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK," close");
    }

  syscall_printf ("%d = close (%d)", res, fd);
  MALLOC_CHECK;
  return res;
}

extern "C" int
isatty (int fd)
{
  int res;
  sigframe thisframe (mainthread);

  if (fdtab.not_open (fd))
    {
      syscall_printf ("0 = isatty (%d)", fd);
      return 0;
    }

  res = fdtab[fd]->is_tty ();
  syscall_printf ("%d = isatty (%d)", res, fd);
  return res;
}

/* Under NT, try to make a hard link using backup API.  If that
   fails or we are Win 95, just copy the file.
   FIXME: We should actually be checking partition type, not OS.
   Under NTFS, we should support hard links.  On FAT partitions,
   we should just copy the file.
*/

extern "C" int
_link (const char *a, const char *b)
{
  int res = -1;
  sigframe thisframe (mainthread);
  path_conv real_a (a, PC_SYM_NOFOLLOW | PC_FULL);
  path_conv real_b (b, PC_SYM_NOFOLLOW | PC_FULL);

  if (real_a.error)
    {
      set_errno (real_a.error);
      goto done;
    }
  if (real_b.error)
    {
      set_errno (real_b.error);
      goto done;
    }
  if (real_b.get_win32 ()[strlen (real_b.get_win32 ()) - 1] == '.')
    {
      syscall_printf ("trailing dot, bailing out");
      set_errno (EINVAL);
      goto done;
    }

  /* Try to make hard link first on Windows NT */
  if (os_being_run == winNT)
    {
      HANDLE hFileSource;

      WIN32_STREAM_ID StreamId;
      DWORD dwBytesWritten;
      LPVOID lpContext;
      DWORD cbPathLen;
      DWORD StreamSize;
      WCHAR wbuf[MAX_PATH];

      BOOL bSuccess;

      hFileSource = CreateFile (
	real_a.get_win32 (),
	FILE_WRITE_ATTRIBUTES,
	FILE_SHARE_READ | FILE_SHARE_WRITE /*| FILE_SHARE_DELETE*/,
	&sec_none_nih, // sa
	OPEN_EXISTING,
	0,
	NULL
	);

      if (hFileSource == INVALID_HANDLE_VALUE)
	{
	  syscall_printf ("cannot open source, %E");
	  goto docopy;
	}

      lpContext = NULL;
      cbPathLen = sys_mbstowcs (wbuf, real_b.get_win32 (), MAX_PATH) * sizeof (WCHAR);

      StreamId.dwStreamId = BACKUP_LINK;
      StreamId.dwStreamAttributes = 0;
      StreamId.dwStreamNameSize = 0;
      StreamId.Size.HighPart = 0;
      StreamId.Size.LowPart = cbPathLen;

      StreamSize = sizeof (WIN32_STREAM_ID) - sizeof (WCHAR**) +
					    StreamId.dwStreamNameSize;

      /* Write the WIN32_STREAM_ID */
      bSuccess = BackupWrite (
	hFileSource,
	(LPBYTE) &StreamId,	// buffer to write
	StreamSize,		// number of bytes to write
	&dwBytesWritten,
	FALSE,			// don't abort yet
	FALSE,			// don't process security
	&lpContext);

      if (bSuccess)
	{
	  /* write the buffer containing the path */
	  /* FIXME: BackupWrite sometimes traps if linkname is invalid.
	     Need to handle. */
	  bSuccess = BackupWrite (
		hFileSource,
		(LPBYTE) wbuf,	// buffer to write
		cbPathLen,	// number of bytes to write
		&dwBytesWritten,
		FALSE,		// don't abort yet
		FALSE,		// don't process security
		&lpContext
		);

	  if (!bSuccess)
	    syscall_printf ("cannot write linkname, %E");

	  /* Free context */
	  BackupWrite (
	    hFileSource,
	    NULL,		// buffer to write
	    0,			// number of bytes to write
	    &dwBytesWritten,
	    TRUE,		// abort
	    FALSE,		// don't process security
	    &lpContext);
	}
      else
	syscall_printf ("cannot write streamId, %E");

      CloseHandle (hFileSource);

      if (!bSuccess)
	goto docopy;

      res = 0;
      goto done;
    }
docopy:
  /* do this with a copy */
  if (CopyFileA (real_a.get_win32 (), real_b.get_win32 (), 1))
    res = 0;
  else
    __seterrno ();

done:
  syscall_printf ("%d = link (%s, %s)", res, a, b);
  return res;
}

#if 0
static BOOL
rel2abssd (PSECURITY_DESCRIPTOR psd_rel, PSECURITY_DESCRIPTOR psd_abs,
		DWORD abslen)
{
#ifdef _MT_SAFE
  struct _winsup_t *r=_reent_winsup();
  char *dacl_buf=r->_dacl_buf;
  char *sacl_buf=r->_sacl_buf;
  char *ownr_buf=r->_ownr_buf;
  char *grp_buf=r->_grp_buf;
#else
  static char dacl_buf[1024];
  static char sacl_buf[1024];
  static char ownr_buf[1024];
  static char grp_buf[1024];
#endif
  DWORD dacl_len = 1024;
  DWORD sacl_len = 1024;
  DWORD ownr_len = 1024;
  DWORD grp_len = 1024;

  BOOL res = MakeAbsoluteSD (psd_rel, psd_abs, &abslen, (PACL) dacl_buf,
			     &dacl_len, (PACL) sacl_buf, &sacl_len,
			     (PSID) ownr_buf, &ownr_len, (PSID) grp_buf,
			     &grp_len);

  syscall_printf ("%d = rel2abssd (...)", res);
  return res;
}
#endif

/* chown: POSIX 5.6.5.1 */
/*
 * chown() is only implemented for Windows NT.  Under other operating
 * systems, it is only a stub that always returns zero.
 */
static int
chown_worker (const char *name, unsigned fmode, uid_t uid, gid_t gid)
{
  int res;
  uid_t old_uid;
  gid_t old_gid;

  if (check_null_empty_path_errno(name))
    return -1;

  if (os_being_run != winNT)    // real chown only works on NT
    res = 0;			// return zero (and do nothing) under Windows 9x
  else
    {
      /* we need Win32 path names because of usage of Win32 API functions */
      path_conv win32_path (PC_NONULLEMPTY, name, fmode);

      if (win32_path.error)
	{
	  set_errno (win32_path.error);
	  res = -1;
	  goto done;
	}

      /* FIXME: This makes chown on a device succeed always.  Someday we'll want
	 to actually allow chown to work properly on devices. */
      if (win32_path.is_device ())
	{
	  res = 0;
	  goto done;
	}

      DWORD attrib = 0;
      if (win32_path.file_attributes () & FILE_ATTRIBUTE_DIRECTORY)
	attrib |= S_IFDIR;
      res = get_file_attribute (win32_path.has_acls (),
				win32_path.get_win32 (),
				(int *) &attrib,
				&old_uid,
				&old_gid);
      if (!res)
	{
	  if (uid == (uid_t) -1)
	    uid = old_uid;
	  if (gid == (gid_t) -1)
	    gid = old_gid;
	  if (win32_path.file_attributes () & FILE_ATTRIBUTE_DIRECTORY)
	    attrib |= S_IFDIR;
	  res = set_file_attribute (win32_path.has_acls (),
				    win32_path.get_win32 (),
				    uid, gid, attrib,
				    cygheap->user.logsrv ());
	}
      if (res != 0 && get_errno () == ENOSYS)
      {
	/* fake - if not supported, pretend we're like win95
	   where it just works */
	res = 0;
      }
    }

done:
  syscall_printf ("%d = %schown (%s,...)",
		  res, (fmode & PC_SYM_IGNORE) ? "l" : "", name);
  return res;
}

extern "C" int
chown (const char * name, uid_t uid, gid_t gid)
{
  sigframe thisframe (mainthread);
  return chown_worker (name, PC_SYM_FOLLOW, uid, gid);
}

extern "C" int
lchown (const char * name, uid_t uid, gid_t gid)
{
  sigframe thisframe (mainthread);
  return chown_worker (name, PC_SYM_IGNORE, uid, gid);
}

extern "C" int
fchown (int fd, uid_t uid, gid_t gid)
{
  sigframe thisframe (mainthread);
  if (fdtab.not_open (fd))
    {
      syscall_printf ("-1 = fchown (%d,...)", fd);
      set_errno (EBADF);
      return -1;
    }

  const char *path = fdtab[fd]->get_name ();

  if (path == NULL)
    {
      syscall_printf ("-1 = fchown (%d,...) (no name)", fd);
      set_errno (ENOSYS);
      return -1;
    }

  syscall_printf ("fchown (%d,...): calling chown_worker (%s,FOLLOW,...)",
		  fd, path);
  return chown_worker (path, PC_SYM_FOLLOW, uid, gid);
}

/* umask: POSIX 5.3.3.1 */
extern "C" mode_t
umask (mode_t mask)
{
  mode_t oldmask;

  oldmask = cygheap->umask;
  cygheap->umask = mask & 0777;
  return oldmask;
}

/* chmod: POSIX 5.6.4.1 */
extern "C" int
chmod (const char *path, mode_t mode)
{
  int res = -1;
  sigframe thisframe (mainthread);

  path_conv win32_path (path);

  if (win32_path.error)
    {
      set_errno (win32_path.error);
      goto done;
    }

  /* FIXME: This makes chmod on a device succeed always.  Someday we'll want
     to actually allow chmod to work properly on devices. */
  if (win32_path.is_device ())
    {
      res = 0;
      goto done;
    }

  if (win32_path.file_attributes () == (DWORD)-1)
    __seterrno ();
  else
    {
      DWORD attr = win32_path.file_attributes ();
      /* temporary erase read only bit, to be able to set file security */
      SetFileAttributesA (win32_path.get_win32 (),
			  attr & ~FILE_ATTRIBUTE_READONLY);

      uid_t uid;
      gid_t gid;

      if (win32_path.file_attributes () & FILE_ATTRIBUTE_DIRECTORY)
	mode |= S_IFDIR;
      get_file_attribute (win32_path.has_acls (),
			  win32_path.get_win32 (),
			  NULL, &uid, &gid);
      if (win32_path.file_attributes () & FILE_ATTRIBUTE_DIRECTORY)
	mode |= S_IFDIR;
      if (! set_file_attribute (win32_path.has_acls (),
				win32_path.get_win32 (),
				uid, gid,
				mode, cygheap->user.logsrv ())
	  && allow_ntsec)
	res = 0;

      /* if the mode we want has any write bits set, we can't
	 be read only. */
      if (mode & (S_IWUSR | S_IWGRP | S_IWOTH))
	attr &= ~FILE_ATTRIBUTE_READONLY;
      else
	attr |= FILE_ATTRIBUTE_READONLY;

      if (S_ISLNK (mode) || S_ISSOCK (mode))
	attr |= FILE_ATTRIBUTE_SYSTEM;

      if (!SetFileAttributesA (win32_path.get_win32 (), attr))
	__seterrno ();
      else
	{
	  /* Correct NTFS security attributes have higher priority */
	  if (res == 0 || !allow_ntsec)
	    res = 0;
	}
    }

done:
  syscall_printf ("%d = chmod (%s, %p)", res, path, mode);
  return res;
}

/* fchmod: P96 5.6.4.1 */

extern "C" int
fchmod (int fd, mode_t mode)
{
  sigframe thisframe (mainthread);
  if (fdtab.not_open (fd))
    {
      syscall_printf ("-1 = fchmod (%d, 0%o)", fd, mode);
      set_errno (EBADF);
      return -1;
    }

  const char *path = fdtab[fd]->get_name ();

  if (path == NULL)
    {
      syscall_printf ("-1 = fchmod (%d, 0%o) (no name)", fd, mode);
      set_errno (ENOSYS);
      return -1;
    }

  syscall_printf ("fchmod (%d, 0%o): calling chmod (%s, 0%o)",
		  fd, mode, path, mode);
  return chmod (path, mode);
}

/* Cygwin internal */
static int
num_entries (const char *win32_name)
{
  WIN32_FIND_DATA buf;
  HANDLE handle;
  char buf1[MAX_PATH];
  int count = 0;

  strcpy (buf1, win32_name);
  int len = strlen (buf1);
  if (len == 0 || isdirsep (buf1[len - 1]))
    strcat (buf1, "*");
  else
    strcat (buf1, "/*");	/* */

  handle = FindFirstFileA (buf1, &buf);

  if (handle == INVALID_HANDLE_VALUE)
    return 0;
  count ++;
  while (FindNextFileA (handle, &buf))
    {
      if ((buf.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY))
	count ++;
    }
  FindClose (handle);
  return count;
}

extern "C" int
_fstat (int fd, struct stat *buf)
{
  int r;
  sigframe thisframe (mainthread);

  if (fdtab.not_open (fd))
    {
      syscall_printf ("-1 = fstat (%d, %p)", fd, buf);
      set_errno (EBADF);
      r = -1;
    }
  else
    {
      memset (buf, 0, sizeof (struct stat));
      r = fdtab[fd]->fstat (buf);
      syscall_printf ("%d = fstat (%d, %x)", r, fd, buf);
    }

  return r;
}

/* fsync: P96 6.6.1.1 */
extern "C" int
fsync (int fd)
{
  sigframe thisframe (mainthread);
  if (fdtab.not_open (fd))
    {
      syscall_printf ("-1 = fsync (%d)", fd);
      set_errno (EBADF);
      return -1;
    }

  HANDLE h = fdtab[fd]->get_handle ();

  if (FlushFileBuffers (h) == 0)
    {
      __seterrno ();
      return -1;
    }
  return 0;
}

/* sync: standards? */
extern "C" int
sync ()
{
  return 0;
}

int __stdcall
stat_dev (DWORD devn, int unit, unsigned long ino, struct stat *buf)
{
  sigframe thisframe (mainthread);
  switch (devn)
    {
    case FH_CONOUT:
    case FH_PIPEW:
      buf->st_mode = STD_WBITS;
      break;
    case FH_CONIN:
    case FH_PIPER:
      buf->st_mode = STD_RBITS;
      break;
    default:
      buf->st_mode = STD_RBITS | S_IWUSR | S_IWGRP | S_IWOTH;
      break;
    }

  buf->st_mode |= S_IFCHR;
  buf->st_blksize = S_BLKSIZE;
  buf->st_nlink = 1;
  buf->st_dev = buf->st_rdev = FHDEVN (devn) << 8 | (unit & 0xff);
  buf->st_ino = ino;
  buf->st_atime = buf->st_mtime = buf->st_ctime = time (NULL);
  return 0;
}

suffix_info stat_suffixes[] =
{
  suffix_info ("", 1),
  suffix_info (".exe", 1),
  suffix_info (NULL)
};

/* Cygwin internal */
static int
stat_worker (const char *caller, const char *name, struct stat *buf,
	     int nofollow)
{
  int res = -1;
  int oret = 1;
  int atts;
  char root[MAX_PATH];
  UINT dtype;
  fhandler_disk_file fh (NULL);

  MALLOC_CHECK;

  debug_printf ("%s (%s, %p)", caller, name, buf);

  path_conv real_path (name, (nofollow ? PC_SYM_NOFOLLOW : PC_SYM_FOLLOW) |
					 PC_FULL, stat_suffixes);

  if (real_path.error)
    {
      set_errno (real_path.error);
      goto done;
    }

  memset (buf, 0, sizeof (struct stat));

  if (real_path.is_device ())
    return stat_dev (real_path.get_devn (), real_path.get_unitn (),
		     hash_path_name (0, real_path.get_win32 ()), buf);

  atts = real_path.file_attributes ();

  debug_printf ("%d = GetFileAttributesA (%s)", atts, real_path.get_win32 ());

  strcpy (root, real_path.get_win32 ());
  dtype = GetDriveType (rootdir (root));

  if ((atts == -1 || !(atts & FILE_ATTRIBUTE_DIRECTORY) ||
       (os_being_run == winNT
	&& dtype != DRIVE_NO_ROOT_DIR
	&& dtype != DRIVE_UNKNOWN))
      && (oret = fh.open (real_path, O_RDONLY | O_BINARY | O_DIROPEN |
			  (nofollow ? O_NOSYMLINK : 0), 0)))
    {
      res = fh.fstat (buf);
      fh.close ();
      /* The number of links to a directory includes the
	 number of subdirectories in the directory, since all
	 those subdirectories point to it.
	 This is too slow on remote drives, so we do without it and
	 set the number of links to 2. */
      /* Unfortunately the count of 2 confuses `find(1)' command. So
	 let's try it with `1' as link count. */
      if (atts != -1 && (atts & FILE_ATTRIBUTE_DIRECTORY))
	buf->st_nlink =
	    (dtype == DRIVE_REMOTE ? 1 : num_entries (real_path.get_win32 ()));
    }
  else if (atts != -1 || (!oret && get_errno () != ENOENT
				&& get_errno () != ENOSHARE))
    {
      /* Unfortunately, the above open may fail if the file exists, though.
	 So we have to care for this case here, too. */
      WIN32_FIND_DATA wfd;
      HANDLE handle;
      buf->st_nlink = 1;
      if (atts != -1
	  && (atts & FILE_ATTRIBUTE_DIRECTORY)
	  && dtype != DRIVE_REMOTE)
	buf->st_nlink = num_entries (real_path.get_win32 ());
      buf->st_dev = FHDEVN(FH_DISK) << 8;
      buf->st_ino = hash_path_name (0, real_path.get_win32 ());
      if (atts != -1 && (atts & FILE_ATTRIBUTE_DIRECTORY))
	buf->st_mode = S_IFDIR;
      else if (real_path.issymlink ())
	buf->st_mode = S_IFLNK;
      else if (real_path.issocket ())
	buf->st_mode = S_IFSOCK;
      else
	buf->st_mode = S_IFREG;
      if (!real_path.has_acls ()
	  || get_file_attribute (real_path.has_acls (), real_path.get_win32 (),
				 &buf->st_mode, &buf->st_uid, &buf->st_gid))
	{
	  buf->st_mode |= STD_RBITS | STD_XBITS;
	  if ((atts & FILE_ATTRIBUTE_READONLY) == 0)
	    buf->st_mode |= STD_WBITS;
	  get_file_attribute (FALSE, real_path.get_win32 (),
			      NULL, &buf->st_uid, &buf->st_gid);
	}
      if ((handle = FindFirstFile (real_path.get_win32(), &wfd))
	  != INVALID_HANDLE_VALUE)
	{
	  buf->st_atime   = to_time_t (&wfd.ftLastAccessTime);
	  buf->st_mtime   = to_time_t (&wfd.ftLastWriteTime);
	  buf->st_ctime   = to_time_t (&wfd.ftCreationTime);
	  buf->st_size    = wfd.nFileSizeLow;
	  buf->st_blksize = S_BLKSIZE;
	  buf->st_blocks  = ((unsigned long) buf->st_size +
			    S_BLKSIZE-1) / S_BLKSIZE;
	  FindClose (handle);
	}
      res = 0;
    }

 done:
  MALLOC_CHECK;
  syscall_printf ("%d = %s (%s, %p)", res, caller, name, buf);
  return res;
}

extern "C" int
_stat (const char *name, struct stat *buf)
{
  sigframe thisframe (mainthread);
  return stat_worker ("stat", name, buf, 0);
}

/* lstat: Provided by SVR4 and 4.3+BSD, POSIX? */
extern "C" int
lstat (const char *name, struct stat *buf)
{
  sigframe thisframe (mainthread);
  return stat_worker ("lstat", name, buf, 1);
}

extern int acl_access (const char *, int);

extern "C" int
access (const char *fn, int flags)
{
  sigframe thisframe (mainthread);
  // flags were incorrectly specified
  if (flags & ~(F_OK|R_OK|W_OK|X_OK))
    {
      set_errno (EINVAL);
      return -1;
    }

  if (allow_ntsec)
    return acl_access (fn, flags);

  struct stat st;
  int r = stat (fn, &st);
  if (r)
    return -1;
  r = -1;
  if (flags & R_OK)
    {
      if (st.st_uid == myself->uid)
	{
	  if (!(st.st_mode & S_IRUSR))
	    goto done;
	}
      else if (st.st_gid == myself->gid)
	{
	  if (!(st.st_mode & S_IRGRP))
	    goto done;
	}
      else if (!(st.st_mode & S_IROTH))
	goto done;
    }
  if (flags & W_OK)
    {
      if (st.st_uid == myself->uid)
	{
	  if (!(st.st_mode & S_IWUSR))
	    goto done;
	}
      else if (st.st_gid == myself->gid)
	{
	  if (!(st.st_mode & S_IWGRP))
	    goto done;
	}
      else if (!(st.st_mode & S_IWOTH))
	goto done;
    }
  if (flags & X_OK)
    {
      if (st.st_uid == myself->uid)
	{
	  if (!(st.st_mode & S_IXUSR))
	    goto done;
	}
      else if (st.st_gid == myself->gid)
	{
	  if (!(st.st_mode & S_IXGRP))
	    goto done;
	}
      else if (!(st.st_mode & S_IXOTH))
	goto done;
    }
  r = 0;
done:
  if (r)
    set_errno (EACCES);
  return r;
}

extern "C" int
_rename (const char *oldpath, const char *newpath)
{
  sigframe thisframe (mainthread);
  int res = 0;

  path_conv real_old (oldpath, PC_SYM_NOFOLLOW);

  if (real_old.error)
    {
      set_errno (real_old.error);
      syscall_printf ("-1 = rename (%s, %s)", oldpath, newpath);
      return -1;
    }

  path_conv real_new (newpath, PC_SYM_NOFOLLOW);

  if (real_new.error)
    {
      set_errno (real_new.error);
      syscall_printf ("-1 = rename (%s, %s)", oldpath, newpath);
      return -1;
    }

  if (! writable_directory (real_old.get_win32 ())
      || ! writable_directory (real_new.get_win32 ()))
    {
      syscall_printf ("-1 = rename (%s, %s)", oldpath, newpath);
      return -1;
    }

  if (real_old.file_attributes () == (DWORD) -1) /* file to move doesn't exist */
    {
       syscall_printf ("file to move doesn't exist");
       return (-1);
    }

  if (real_new.file_attributes () != (DWORD) -1 &&
      real_new.file_attributes () & FILE_ATTRIBUTE_READONLY)
    {
      /* Destination file exists and is read only, change that or else
	 the rename won't work. */
      SetFileAttributesA (real_new.get_win32 (), real_new.file_attributes () & ~ FILE_ATTRIBUTE_READONLY);
    }

  if (!MoveFile (real_old.get_win32 (), real_new.get_win32 ()))
    res = -1;

  if (res == 0 || (GetLastError () != ERROR_ALREADY_EXISTS
		   && GetLastError () != ERROR_FILE_EXISTS))
    goto done;

  if (os_being_run == winNT)
    {
      if (MoveFileEx (real_old.get_win32 (), real_new.get_win32 (),
		      MOVEFILE_REPLACE_EXISTING))
	res = 0;
    }
  else
    {
      syscall_printf ("try win95 hack");
      for (;;)
	{
	  if (!DeleteFileA (real_new.get_win32 ()) &&
	      GetLastError () != ERROR_FILE_NOT_FOUND)
	    {
	      syscall_printf ("deleting %s to be paranoid",
			      real_new.get_win32 ());
	      break;
	    }
	  else
	    {
	      if (MoveFile (real_old.get_win32 (), real_new.get_win32 ()))
		{
		  res = 0;
		  break;
		}
	    }
	}
    }

done:
  if (res)
    __seterrno ();

  if (res == 0)
    {
      /* make the new file have the permissions of the old one */
      SetFileAttributesA (real_new.get_win32 (), real_old.file_attributes ());
    }

  syscall_printf ("%d = rename (%s, %s)", res, real_old.get_win32 (),
		  real_new.get_win32 ());

  return res;
}

extern "C" int
system (const char *cmdstring)
{
  sigframe thisframe (mainthread);
  int res;
  const char* command[4];
  _sig_func_ptr oldint, oldquit;
  sigset_t child_block, old_mask;

  if (cmdstring == (const char *) NULL)
	return 1;

  oldint = signal (SIGINT, SIG_IGN);
  oldquit = signal (SIGQUIT, SIG_IGN);
  sigemptyset (&child_block);
  sigaddset (&child_block, SIGCHLD);
  (void) sigprocmask (SIG_BLOCK, &child_block, &old_mask);

  command[0] = "sh";
  command[1] = "-c";
  command[2] = cmdstring;
  command[3] = (const char *) NULL;

  if ((res = spawnvp (_P_WAIT, "sh", command)) == -1)
    {
      // when exec fails, return value should be as if shell
      // executed exit (127)
      res = 127;
    }

  signal (SIGINT, oldint);
  signal (SIGQUIT, oldquit);
  (void) sigprocmask (SIG_SETMASK, &old_mask, 0);
  return res;
}

extern "C" void
setdtablesize (int size)
{
  if (size > (int)fdtab.size)
    fdtab.extend (size);
}

extern "C" int
getdtablesize ()
{
  return fdtab.size;
}

extern "C" size_t
getpagesize ()
{
  return sysconf (_SC_PAGESIZE);
}

/* FIXME: not all values are correct... */
extern "C" long int
fpathconf (int fd, int v)
{
  switch (v)
    {
    case _PC_LINK_MAX:
      return _POSIX_LINK_MAX;
    case _PC_MAX_CANON:
    case _PC_MAX_INPUT:
      if (isatty (fd))
	return _POSIX_MAX_CANON;
      else
	{
	  set_errno (EBADF);
	  return -1;
	}
    case _PC_NAME_MAX:
    case _PC_PATH_MAX:
      return PATH_MAX;
    case _PC_PIPE_BUF:
      return 4096;
    case _PC_CHOWN_RESTRICTED:
    case _PC_NO_TRUNC:
      return -1;
    case _PC_VDISABLE:
      if (isatty (fd))
	return -1;
      else
	{
	  set_errno (EBADF);
	  return -1;
	}
    default:
      set_errno (EINVAL);
      return -1;
    }
}

extern "C" long int
pathconf (const char *file, int v)
{
  switch (v)
    {
    case _PC_PATH_MAX:
      return PATH_MAX - strlen (file);
    case _PC_NAME_MAX:
      return PATH_MAX;
    case _PC_LINK_MAX:
      return _POSIX_LINK_MAX;
    case _PC_MAX_CANON:
    case _PC_MAX_INPUT:
	return _POSIX_MAX_CANON;
    case _PC_PIPE_BUF:
      return 4096;
    case _PC_CHOWN_RESTRICTED:
    case _PC_NO_TRUNC:
      return -1;
    case _PC_VDISABLE:
	return -1;
    default:
      set_errno (EINVAL);
      return -1;
    }
}

extern "C" char *
ttyname (int fd)
{
  if (fdtab.not_open (fd) || !fdtab[fd]->is_tty ())
    {
      return 0;
    }
  return (char *)(fdtab[fd]->ttyname ());
}

extern "C" char *
ctermid (char *str)
{
  static NO_COPY char buf[16];
  if (str == NULL)
    str = buf;
  if (!tty_attached (myself))
    strcpy (str, "/dev/conin");
  else
    __small_sprintf (str, "/dev/tty%d", myself->ctty);
  return str;
}

/* Tells stdio if it should do the cr/lf conversion for this file */
extern "C" int
_cygwin_istext_for_stdio (int fd)
{
  syscall_printf("_cygwin_istext_for_stdio (%d)\n", fd);
  if (CYGWIN_VERSION_OLD_STDIO_CRLF_HANDLING)
    {
      syscall_printf(" _cifs: old API\n");
      return 0; /* we do it for old apps, due to getc/putc macros */
    }

  if (fdtab.not_open (fd))
    {
      syscall_printf(" _cifs: fd not open\n");
      return 0;
    }

  fhandler_base *p = fdtab[fd];

  if (p->get_device() != FH_DISK)
    {
      syscall_printf(" _cifs: fd not disk file\n");
      return 0;
    }

  if (p->get_w_binary () || p->get_r_binary ())
    {
      syscall_printf(" _cifs: get_*_binary\n");
      return 0;
    }

  syscall_printf("_cygwin_istext_for_stdio says yes\n");
  return 1;
}

/* internal newlib function */
extern "C" int _fwalk (struct _reent *ptr, int (*function)(FILE *));

static int setmode_mode;
static int setmode_file;

static int
setmode_helper (FILE *f)
{
  if (fileno(f) != setmode_file)
    return 0;
  syscall_printf("setmode: file was %s now %s\n",
		 f->_flags & __SCLE ? "cle" : "raw",
		 setmode_mode & O_TEXT ? "cle" : "raw");
  if (setmode_mode & O_TEXT)
    f->_flags |= __SCLE;
  else
    f->_flags &= ~__SCLE;
  return 0;
}

extern "C" int
getmode (int fd)
{
  if (fdtab.not_open (fd))
    {
      set_errno (EBADF);
      return -1;
    }

  return fdtab[fd]->get_flags () & (O_BINARY | O_TEXT);
}

/* Set a file descriptor into text or binary mode, returning the
   previous mode.  */

extern "C" int
setmode (int fd, int mode)
{
  if (fdtab.not_open (fd))
    {
      set_errno (EBADF);
      return -1;
    }
  if (mode != O_BINARY  && mode != O_TEXT)
    {
      set_errno (EINVAL);
      return -1;
    }

  fhandler_base *p = fdtab[fd];

  /* Note that we have no way to indicate the case that writes are
     binary but not reads, or vice-versa.  These cases can arise when
     using the tty or console interface.  People using those
     interfaces should not use setmode.  */

  int res;
  if (p->get_w_binary () && p->get_r_binary ())
    res = O_BINARY;
  else
    res = O_TEXT;

  if (mode & O_BINARY)
    {
      p->set_w_binary (1);
      p->set_r_binary (1);
    }
  else
    {
      p->set_w_binary (0);
      p->set_r_binary (0);
    }

  if (_cygwin_istext_for_stdio (fd))
    setmode_mode = O_TEXT;
  else
    setmode_mode = O_BINARY;
  setmode_file = fd;
  _fwalk(_REENT, setmode_helper);

  syscall_printf ("setmode (%d, %s) returns %s\n", fd,
		  mode&O_TEXT ? "text" : "binary",
		  res&O_TEXT ? "text" : "binary");

  return res;
}

/* ftruncate: P96 5.6.7.1 */
extern "C" int
ftruncate (int fd, off_t length)
{
  sigframe thisframe (mainthread);
  int res = -1;

  if (fdtab.not_open (fd))
    {
      set_errno (EBADF);
    }
  else
    {
      HANDLE h = fdtab[fd]->get_handle ();
      off_t prev_loc;

      if (h)
	{
	  /* remember curr file pointer location */
	  prev_loc = fdtab[fd]->lseek (0, SEEK_CUR);

	  fdtab[fd]->lseek (length, SEEK_SET);
	  if (!SetEndOfFile (h))
	    {
	      __seterrno ();
	    }
	  else
	    res = 0;

	  /* restore original file pointer location */
	  fdtab[fd]->lseek (prev_loc, 0);
	}
    }
  syscall_printf ("%d = ftruncate (%d, %d)", res, fd, length);

  return res;
}

/* truncate: Provided by SVR4 and 4.3+BSD.  Not part of POSIX.1 or XPG3 */
/* FIXME: untested */
extern "C" int
truncate (const char *pathname, off_t length)
{
  sigframe thisframe (mainthread);
  int fd;
  int res = -1;

  fd = open (pathname, O_RDWR);

  if (fd == -1)
    {
      set_errno (EBADF);
    }
  else
    {
      res = ftruncate (fd, length);
      close (fd);
    }
  syscall_printf ("%d = truncate (%s, %d)", res, pathname, length);

  return res;
}

extern "C" long
get_osfhandle (int fd)
{
  long res = -1;

  if (fdtab.not_open (fd))
    {
      set_errno (EBADF);
    }
  else
    {
      res = (long) fdtab[fd]->get_handle ();
    }
  syscall_printf ("%d = get_osfhandle(%d)", res, fd);

  return res;
}

extern "C" int
statfs (const char *fname, struct statfs *sfs)
{
  sigframe thisframe (mainthread);
  if (!sfs)
    {
      set_errno (EFAULT);
      return -1;
    }

  path_conv full_path(fname, PC_SYM_FOLLOW | PC_FULL);
  char *root = rootdir (full_path);

  syscall_printf ("statfs %s", root);

  DWORD spc, bps, freec, totalc;

  if (!GetDiskFreeSpace (root, &spc, &bps, &freec, &totalc))
    {
      __seterrno ();
      return -1;
    }

  DWORD vsn, maxlen, flags;

  if (!GetVolumeInformation (root, NULL, 0, &vsn, &maxlen, &flags, NULL, 0))
    {
      __seterrno ();
      return -1;
    }
  sfs->f_type = flags;
  sfs->f_bsize = spc*bps;
  sfs->f_blocks = totalc;
  sfs->f_bfree = sfs->f_bavail = freec;
  sfs->f_files = -1;
  sfs->f_ffree = -1;
  sfs->f_fsid = vsn;
  sfs->f_namelen = maxlen;
  return 0;
}

extern "C" int
fstatfs (int fd, struct statfs *sfs)
{
  sigframe thisframe (mainthread);
  if (fdtab.not_open (fd))
    {
      set_errno (EBADF);
      return -1;
    }
  fhandler_disk_file *f = (fhandler_disk_file *) fdtab[fd];
  return statfs (f->get_name (), sfs);
}

/* setpgid: POSIX 4.3.3.1 */
extern "C" int
setpgid (pid_t pid, pid_t pgid)
{
  sigframe thisframe (mainthread);
  int res = -1;
  if (pid == 0)
    pid = getpid ();
  if (pgid == 0)
    pgid = pid;

  if (pgid < 0)
    {
      set_errno (EINVAL);
      goto out;
    }
  else
    {
      pinfo p (pid);
      if (!p)
	{
	  set_errno (ESRCH);
	  goto out;
	}
      /* A process may only change the process group of itself and its children */
      if (p == myself || p->ppid == myself->pid)
	{
	  p->pgid = pgid;
	  if (p->pid != p->pgid)
	    p->set_has_pgid_children (0);
	  res = 0;
	}
      else
	{
	  set_errno (EPERM);
	  goto out;
	}
    }
out:
  syscall_printf ("pid %d, pgid %d, res %d", pid, pgid, res);
  return res;
}

extern "C" pid_t
getpgid (pid_t pid)
{
  sigframe thisframe (mainthread);
  if (pid == 0)
    pid = getpid ();

  pinfo p (pid);
  if (p == 0)
    {
      set_errno (ESRCH);
      return -1;
    }
  return p->pgid;
}

extern "C" int
setpgrp (void)
{
  sigframe thisframe (mainthread);
  return setpgid (0, 0);
}

extern "C" pid_t
getpgrp (void)
{
  sigframe thisframe (mainthread);
  return getpgid (0);
}

extern "C" char *
ptsname (int fd)
{
  sigframe thisframe (mainthread);
  if (fdtab.not_open (fd))
    {
      set_errno (EBADF);
      return 0;
    }
  return (char *)(fdtab[fd]->ptsname ());
}

/* FIXME: what is this? */
extern "C" int
regfree ()
{
  return 0;
}

/* mknod was the call to create directories before the introduction
   of mkdir in 4.2BSD and SVR3.  Use of mknod required superuser privs
   so the mkdir command had to be setuid root.
   Although mknod hasn't been implemented yet, some GNU tools (e.g. the
   fileutils) assume its existence so we must provide a stub that always
   fails. */
extern "C" int
mknod ()
{
  set_errno (ENOSYS);
  return -1;
}

/* setgid: POSIX 4.2.2.1 */
extern "C" int
setgid (gid_t gid)
{
  int ret = setegid (gid);
  if (!ret)
    cygheap->user.real_gid = myself->gid;
  return ret;
}

/* setuid: POSIX 4.2.2.1 */
extern "C" int
setuid (uid_t uid)
{
  int ret = seteuid (uid);
  if (!ret)
    cygheap->user.real_uid = myself->uid;
  debug_printf ("real: %d, effective: %d", cygheap->user.real_uid, myself->uid);
  return ret;
}

extern const char *internal_getlogin (cygheap_user &user);

/* seteuid: standards? */
extern "C" int
seteuid (uid_t uid)
{
  sigframe thisframe (mainthread);
  if (os_being_run == winNT)
    {
      if (uid != (uid_t) -1)
	{
	  struct passwd *pw_new = getpwuid (uid);
	  if (!pw_new)
	    {
	      set_errno (EINVAL);
	      return -1;
	    }

	  if (uid != myself->uid)
	    if (uid == cygheap->user.orig_uid)
	      {
		debug_printf ("RevertToSelf() (uid == orig_uid, token=%d)",
			      cygheap->user.token);
		RevertToSelf();
		if (cygheap->user.token != INVALID_HANDLE_VALUE)
		  cygheap->user.impersonated = FALSE;
	      }
	    else if (!cygheap->user.impersonated)
	      {
		debug_printf ("Impersonate(uid == %d)", uid);
		RevertToSelf();
		if (cygheap->user.token != INVALID_HANDLE_VALUE)
		  if (!ImpersonateLoggedOnUser (cygheap->user.token))
		    system_printf ("Impersonate(%d) in set(e)uid failed: %E",
				   cygheap->user.token);
		  else
		    cygheap->user.impersonated = TRUE;
	      }

	  cygheap_user user;
	  /* user.token is used in internal_getlogin() to determine if
	     impersonation is active. If so, the token is used for
	     retrieving user's SID. */
	  user.token = cygheap->user.impersonated ? cygheap->user.token
					          : INVALID_HANDLE_VALUE;
	  struct passwd *pw_cur = getpwnam (internal_getlogin (user));
	  if (pw_cur != pw_new)
	    {
	      debug_printf ("Diffs!!! token: %d, cur: %d, new: %d, orig: %d",
			    cygheap->user.token, pw_cur->pw_uid,
			    pw_new->pw_uid, cygheap->user.orig_uid);
	      set_errno (EPERM);
	      return -1;
	    }
	  myself->uid = uid;
	  cygheap->user = user;
	}
    }
  else
    set_errno (ENOSYS);
  debug_printf ("real: %d, effective: %d", cygheap->user.real_uid, myself->uid);
  return 0;
}

/* setegid: from System V.  */
extern "C" int
setegid (gid_t gid)
{
  sigframe thisframe (mainthread);
  if (os_being_run == winNT)
    {
      if (gid != (gid_t) -1)
	{
	  if (!getgrgid (gid))
	    {
	      set_errno (EINVAL);
	      return -1;
	    }
	  myself->gid = gid;
	}
    }
  else
    set_errno (ENOSYS);
  return 0;
}

/* chroot: privileged Unix system call.  */
/* FIXME: Not privileged here. How should this be done? */
extern "C" int
chroot (const char *newroot)
{
  sigframe thisframe (mainthread);
  int ret = -1;
  path_conv path(newroot, PC_SYM_FOLLOW | PC_FULL);

  if (path.error)
    goto done;
  if (path.file_attributes () == (DWORD)-1)
    {
      set_errno (ENOENT);
      goto done;
    }
  if (!(path.file_attributes () & FILE_ATTRIBUTE_DIRECTORY))
    {
      set_errno (ENOTDIR);
      goto done;
    }
  char buf[MAX_PATH + 1];
  ret = cygwin_shared->mount.conv_to_posix_path (path.get_win32 (),
						 buf, 0);
  if (ret)
    {
      set_errno (ret);
      goto done;
    }
  cygheap->root = buf;
  ret = 0;

done:
  syscall_printf ("%d = chroot (%s)", ret ? get_errno () : 0,
				      newroot ? newroot : "NULL");
  return ret;
}

extern "C" int
creat (const char *path, mode_t mode)
{
  sigframe thisframe (mainthread);
  return open (path, O_WRONLY | O_CREAT | O_TRUNC, mode);
}

extern "C" void
__assertfail ()
{
  exit (99);
}

extern "C" int
getw (FILE *fp)
{
  sigframe thisframe (mainthread);
  int w, ret;
  ret = fread (&w, sizeof (int), 1, fp);
  return ret != 1 ? EOF : w;
}

extern "C" int
putw (int w, FILE *fp)
{
  sigframe thisframe (mainthread);
  int ret;
  ret = fwrite (&w, sizeof (int), 1, fp);
  if (feof (fp) || ferror (fp))
    return -1;
  return 0;
}

extern "C" int
wcscmp (const wchar_t *s1, const wchar_t *s2)
{
  while (*s1  && *s1 == *s2)
    {
      s1++;
      s2++;
    }

  return (*(unsigned short *) s1) - (*(unsigned short *) s2);
}

extern "C" size_t
wcslen (const wchar_t *s1)
{
  int l = 0;
  while (s1[l])
    l++;
  return l;
}

/* FIXME: to do this right, maybe work out the usoft va_list machine
   and use wsvprintfW instead?
*/
extern "C" int
wprintf (const char *fmt, ...)
{
  va_list ap;
  int ret;

  va_start (ap, fmt);
  ret = vprintf (fmt, ap);
  va_end (ap);
  return ret;
}

extern "C" int
vhangup ()
{
  set_errno (ENOSYS);
  return -1;
}

extern "C" _PTR
memccpy (_PTR out, const _PTR in, int c, size_t len)
{
  const char *inc = (char *) in;
  char *outc = (char *) out;

  while (len)
    {
      char x = *inc++;
      *outc++ = x;
      if (x == c)
	return outc;
      len --;
    }
  return 0;
}

extern "C" int
nice (int incr)
{
  sigframe thisframe (mainthread);
  DWORD priority[] =
    {
      IDLE_PRIORITY_CLASS,
      IDLE_PRIORITY_CLASS,
      NORMAL_PRIORITY_CLASS,
      HIGH_PRIORITY_CLASS,
      REALTIME_PRIORITY_CLASS,
      REALTIME_PRIORITY_CLASS
    };
  int curr = 2;

  switch (GetPriorityClass (hMainProc))
    {
      case IDLE_PRIORITY_CLASS:
	curr = 1;
	break;
      case NORMAL_PRIORITY_CLASS:
	curr = 2;
	break;
      case HIGH_PRIORITY_CLASS:
	curr = 3;
	break;
      case REALTIME_PRIORITY_CLASS:
	curr = 4;
	break;
    }
  if (incr > 0)
    incr = -1;
  else if (incr < 0)
    incr = 1;

  if (SetPriorityClass (hMainProc, priority[curr + incr]) == FALSE)
    {
      __seterrno ();
      return -1;
    }

  return 0;
}

/*
 * Find the first bit set in I.
 */

extern "C" int
ffs (int i)
{
  static const unsigned char table[] =
    {
      0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
      6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
      7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
      7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
      8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
      8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
      8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
      8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
    };
  unsigned long int a;
  unsigned long int x = i & -i;

  a = x <= 0xffff ? (x <= 0xff ? 0 : 8) : (x <= 0xffffff ?  16 : 24);

  return table[x >> a] + a;
}

extern "C" void
login (struct utmp *ut)
{
  sigframe thisframe (mainthread);
  register int fd;
  int currtty = ttyslot ();

  if (currtty >= 0 && (fd = open (_PATH_UTMP, O_WRONLY | O_CREAT | O_BINARY,
					 0644)) >= 0)
    {
      (void) lseek (fd, (long) (currtty * sizeof (struct utmp)), SEEK_SET);
      (void) write (fd, (char *) ut, sizeof (struct utmp));
      (void) close (fd);
    }
  if ((fd = open (_PATH_WTMP, O_WRONLY | O_APPEND | O_BINARY, 0)) >= 0)
    {
      (void) write (fd, (char *) ut, sizeof (struct utmp));
      (void) close (fd);
    }
}

/* It isn't possible to use unix-style I/O function in logout code because
cygwin's I/O subsystem may be inaccessible at logout() call time.
FIXME (cgf): huh?
*/
extern "C" int
logout (char *line)
{
  sigframe thisframe (mainthread);
  int res = 0;
  HANDLE ut_fd;
  static const char path_utmp[] = _PATH_UTMP;

  path_conv win32_path (path_utmp);
  if (win32_path.error)
    return 0;

  ut_fd = CreateFile (win32_path.get_win32 (),
			GENERIC_READ | GENERIC_WRITE,
			FILE_SHARE_READ | FILE_SHARE_WRITE,
			&sec_none_nih,
			OPEN_EXISTING,
			FILE_ATTRIBUTE_NORMAL,
			NULL);
  if (ut_fd != INVALID_HANDLE_VALUE)
    {
      struct utmp *ut;
      struct utmp ut_buf[100];
      off_t pos = 0;		/* Position in file */
      DWORD rd;

      while (!res && ReadFile (ut_fd, ut_buf, sizeof ut_buf, &rd, NULL)
	     && rd != 0)
	{
	  struct utmp *ut_end = (struct utmp *) ((char *) ut_buf + rd);

	  for (ut = ut_buf; ut < ut_end; ut++, pos += sizeof (*ut))
	    if (ut->ut_name[0]
		&& strncmp (ut->ut_line, line, sizeof (ut->ut_line)) == 0)
	      /* Found the entry for LINE; mark it as logged out.  */
	      {
		/* Zero out entries describing who's logged in.  */
		bzero (ut->ut_name, sizeof (ut->ut_name));
		bzero (ut->ut_host, sizeof (ut->ut_host));
		time (&ut->ut_time);

		/* Now seek back to the position in utmp at which UT occured,
		   and write the new version of UT there.  */
		if ((SetFilePointer (ut_fd, pos, 0, FILE_BEGIN) != 0xFFFFFFFF)
		    && (WriteFile (ut_fd, (char *) ut, sizeof (*ut),
				   &rd, NULL)))
		  {
		    res = 1;
		    break;
		  }
	      }
	}

      CloseHandle (ut_fd);
    }

  return res;
}