libc/winsup/cygwin/syscalls.cc

/* syscalls.cc: syscalls

   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002 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 <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 <wininet.h>
#include <lmcons.h> /* for UNLEN */
#include <cygwin/version.h>
#include <sys/cygwin.h>
#include "cygerrno.h"
#include "perprocess.h"
#include "security.h"
#include "fhandler.h"
#include "path.h"
#include "dtable.h"
#include "sigproc.h"
#include "pinfo.h"
#include <unistd.h>
#include "shared_info.h"
#include "cygheap.h"

SYSTEM_INFO system_info;

/* 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_all_files");

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

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

BOOL __stdcall
check_pty_fds (void)
{
  int res = FALSE;
  SetResourceLock (LOCK_FD_LIST, WRITE_LOCK, "check_pty_fds");
  fhandler_base *fh;
  for (int i = 0; i < (int) cygheap->fdtab.size; i++)
    if ((fh = cygheap->fdtab[i]) != NULL &&
	(fh->get_device () == FH_TTYS || fh->get_device () == FH_PTYM))
      {
	res = TRUE;
	break;
      }
  ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK, "check_pty_fds");
  return res;
}

int
dup (int fd)
{
  return cygheap->fdtab.dup2 (fd, cygheap_fdnew ());
}

int
dup2 (int oldfd, int newfd)
{
  return cygheap->fdtab.dup2 (oldfd, newfd);
}

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 ());

  if (!win32_name.exists ())
    {
      syscall_printf ("unlinking a nonexistent file");
      set_errno (ENOENT);
      goto done;
    }
  else if (win32_name.isdir ())
    {
      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;
    }

  /* Check for shortcut as symlink condition. */
  if (win32_name.has_attribute (FILE_ATTRIBUTE_READONLY))
    {
      int len = strlen (win32_name);
      if (len > 4 && strcasematch ((char *) win32_name + len - 4, ".lnk"))
	SetFileAttributes (win32_name, (DWORD) win32_name & ~FILE_ATTRIBUTE_READONLY);
    }

  DWORD lasterr;
  lasterr = 0;
  for (int i = 0; i < 2; i++)
    {
      if (DeleteFile (win32_name))
	{
	  syscall_printf ("DeleteFile succeeded");
	  goto ok;
	}

      lasterr = GetLastError ();
      if (i || lasterr != ERROR_ACCESS_DENIED || win32_name.issymlink ())
	break;		/* Couldn't delete it. */

      /* if access denied, chmod to be writable, in case it is not,
	 and try again */
      (void) chmod (win32_name, 0777);
    }

  /* Windows 9x seems to report ERROR_ACCESS_DENIED rather than sharing
     violation.  So, set lasterr to ERROR_SHARING_VIOLATION in this case
     to simplify tests. */
  if (wincap.access_denied_on_delete () && lasterr == ERROR_ACCESS_DENIED
      && !win32_name.isremote ())
    lasterr = ERROR_SHARING_VIOLATION;

  /* Tried to delete file by normal DeleteFile and by resetting protection
     and then deleting.  That didn't work.

     There are two possible reasons for this:  1) The file may be opened and
     Windows is not allowing it to be deleted, or 2) We may not have permissions
     to delete the file.

     So, first assume that it may be 1) and try to remove the file using the
     Windows FILE_FLAG_DELETE_ON_CLOSE semantics.  This seems to work only
     spottily on Windows 9x/Me but it does seem to work reliably on NT as
     long as the file doesn't exist on a remote drive. */

  bool delete_on_close_ok;

  delete_on_close_ok  = !win32_name.isremote ()
			&& wincap.has_delete_on_close ();

  /* Attempt to use "delete on close" semantics to handle removing
     a file which may be open. */
  HANDLE h;
  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)
    {
      if (GetLastError () == ERROR_FILE_NOT_FOUND)
	goto ok;
    }
  else
    {
      CloseHandle (h);
      syscall_printf ("CreateFile/CloseHandle succeeded");
      /* Everything is fine if the file has disappeared or if we know that the
	 FILE_FLAG_DELETE_ON_CLOSE will eventually work. */
      if (GetFileAttributes (win32_name) == INVALID_FILE_ATTRIBUTES
	  || delete_on_close_ok)
	goto ok;	/* The file is either gone already or will eventually be
			   deleted by the OS. */
    }

  /* FILE_FLAGS_DELETE_ON_CLOSE was a bust.  If this is a sharing
     violation, then queue the file for deletion when the process
     exits.  Otherwise, punt. */
  if (lasterr != ERROR_SHARING_VIOLATION)
    goto err;

  syscall_printf ("couldn't delete file, err %d", lasterr);

  /* Add file to the "to be deleted" queue. */
  cygwin_shared->delqueue.queue_file (win32_name);

 /* Success condition. */
 ok:
  res = 0;
  goto done;

 /* Error condition. */
 err:
  __seterrno ();
  res = -1;

 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;
    }

  return win32_name.isdir () ? rmdir (ourname) : _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)
{
  if (myself->pgid != _getpid ())
    {
      if (myself->ctty == TTY_CONSOLE &&
	  !cygheap->fdtab.has_console_fds () &&
	  !check_pty_fds ())
	FreeConsole ();
      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" ssize_t
_read (int fd, void *ptr, size_t len)
{
  if (len == 0)
    return 0;

  if (__check_null_invalid_struct_errno (ptr, len))
    return -1;

  int res;
  extern int sigcatchers;
  int e = get_errno ();

  while (1)
    {
      sigframe thisframe (mainthread);

      cygheap_fdget cfd (fd);
      if (cfd < 0)
	return -1;

      DWORD wait = cfd->is_nonblocking () ? 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);

      if (wait && (!cfd->is_slow () || cfd->get_r_no_interrupt ()))
	debug_printf ("non-interruptible read\n");
      else if (!cfd->ready_for_read (fd, wait))
	{
	  res = -1;
	  goto out;
	}

      /* FIXME: This is not thread safe.  We need some method to
	 ensure that an fd, closed in another thread, aborts I/O
	 operations. */
      if (!cfd.isopen())
	return -1;

      /* Check to see if this is a background read from a "tty",
	 sending a SIGTTIN, if appropriate */
      res = cfd->bg_check (SIGTTIN);

      if (!cfd.isopen())
	return -1;

      if (res > bg_eof)
	{
	  myself->process_state |= PID_TTYIN;
	  if (!cfd.isopen())
	    return -1;
	  res = cfd->read (ptr, len);
	  myself->process_state &= ~PID_TTYIN;
	}

    out:

      if (res && get_errno () == EACCES &&
	  !(cfd->get_flags () & (O_RDONLY | O_RDWR)))
	{
	  set_errno (EBADF);
	  break;
	}

      if (res >= 0 || get_errno () != EINTR || !thisframe.call_signal_handler ())
	break;
      set_errno (e);
    }

  syscall_printf ("%d = read (%d, %p, %d), errno %d", res, fd, ptr, len,
		  get_errno ());
  MALLOC_CHECK;
  return res;
}

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

  sigframe thisframe (mainthread);
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    goto done;

  /* No further action required for len == 0 */
  if (len == 0)
    {
      res = 0;
      goto done;
    }

  if (len && __check_invalid_read_ptr_errno (ptr, len))
    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);

  res = cfd->bg_check (SIGTTOU);

  if (res > bg_eof)
    {
      myself->process_state |= PID_TTYOU;
      res = cfd->write (ptr, len);
      myself->process_state &= ~PID_TTYOU;
      if (res && get_errno () == EACCES &&
	  !(cfd->get_flags () & (O_WRONLY | O_RDWR)))
	set_errno (EBADF);
    }

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);

  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 res = -1;
  va_list ap;
  mode_t mode = 0;
  sigframe thisframe (mainthread);

  syscall_printf ("open (%s, %p)", unix_path, flags);
  if (!check_null_empty_str_errno (unix_path))
    {
      /* check for optional mode argument */
      va_start (ap, flags);
      mode = va_arg (ap, mode_t);
      va_end (ap);

      fhandler_base *fh;
      cygheap_fdnew fd;

      if (fd >= 0)
	{
	  path_conv pc;
	  if (!(fh = cygheap->fdtab.build_fhandler_from_name (fd, unix_path,
							      NULL, pc)))
	    res = -1;		// errno already set
	  else if (!fh->open (&pc, flags, (mode & 07777) & ~cygheap->umask))
	    {
	      fd.release ();
	      res = -1;
	    }
	  else if ((res = fd) <= 2)
	    set_std_handle (res);
	}
    }

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

extern "C" __off64_t
lseek64 (int fd, __off64_t pos, int dir)
{
  __off64_t res;
  sigframe thisframe (mainthread);

  if (dir != SEEK_SET && dir != SEEK_CUR && dir != SEEK_END)
    {
      set_errno (EINVAL);
      res = -1;
    }
  else
    {
      cygheap_fdget cfd (fd);
      if (cfd >= 0)
	res = cfd->lseek (pos, dir);
      else
	res = -1;
    }
  syscall_printf ("%d = lseek (%d, %D, %d)", res, fd, pos, dir);

  return res;
}

extern "C" __off32_t
_lseek (int fd, __off32_t pos, int dir)
{
  return lseek64 (fd, (__off64_t) pos, dir);
}

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

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

  MALLOC_CHECK;
  cygheap_fdget cfd (fd, true);
  if (cfd < 0)
    res = -1;
  else
    {
      cfd->close ();
      cfd.release ();
      res = 0;
    }

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

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

  cygheap_fdget cfd (fd);
  if (cfd < 0)
    res = 0;
  else
    res = cfd->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.case_clash ? ECASECLASH : real_b.error);
      goto done;
    }

  if (real_b.exists ())
    {
      syscall_printf ("file '%s' exists?", (char *)real_b);
      set_errno (EEXIST);
      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 (wincap.has_hard_links ())
    {
      if (CreateHardLinkA (real_b.get_win32 (), real_a.get_win32 (), NULL))
	{
	  res = 0;
	  goto done;
	}

      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;
}

/* 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, __uid32_t uid, __gid32_t gid)
{
  int res;
  __uid32_t old_uid;
  __gid32_t old_gid;

  if (check_null_empty_str_errno (name))
    return -1;

  if (!wincap.has_security ())  // 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.isdir ())
	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 == ILLEGAL_UID)
	    uid = old_uid;
	  if (gid == ILLEGAL_GID)
	    gid = old_gid;
	  if (win32_path.isdir())
	    attrib |= S_IFDIR;
	  res = set_file_attribute (win32_path.has_acls (), win32_path, uid,
				    gid, attrib, cygheap->user.logsrv ());
	}
      if (res != 0 && (!win32_path.has_acls () || !allow_ntsec))
	{
	  /* 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_NOFOLLOW) ? "l" : "", name);
  return res;
}

extern "C" int
chown32 (const char * name, __uid32_t uid, __gid32_t gid)
{
  sigframe thisframe (mainthread);
  return chown_worker (name, PC_SYM_FOLLOW, uid, gid);
}

extern "C" int
chown (const char * name, __uid16_t uid, __gid16_t gid)
{
  sigframe thisframe (mainthread);
  return chown_worker (name, PC_SYM_FOLLOW, uid, gid16togid32 (gid));
}

extern "C" int
lchown32 (const char * name, __uid32_t uid, __gid32_t gid)
{
  sigframe thisframe (mainthread);
  return chown_worker (name, PC_SYM_NOFOLLOW, uid, gid);
}

extern "C" int
lchown (const char * name, __uid16_t uid, __gid16_t gid)
{
  sigframe thisframe (mainthread);
  return chown_worker (name, PC_SYM_NOFOLLOW, uid, gid16togid32 (gid));
}

extern "C" int
fchown32 (int fd, __uid32_t uid, __gid32_t gid)
{
  sigframe thisframe (mainthread);
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    {
      syscall_printf ("-1 = fchown (%d,...)", fd);
      return -1;
    }

  const char *path = cfd->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);
}

extern "C" int
fchown (int fd, __uid16_t uid, __gid16_t gid)
{
  return fchown32 (fd, uid, gid16togid32 (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.exists ())
    __seterrno ();
  else
    {
      /* temporary erase read only bit, to be able to set file security */
      SetFileAttributes (win32_path, (DWORD) win32_path & ~FILE_ATTRIBUTE_READONLY);

      __uid32_t uid;
      __gid32_t gid;

      if (win32_path.isdir ())
	mode |= S_IFDIR;
      get_file_attribute (win32_path.has_acls (),
			  win32_path.get_win32 (),
			  NULL, &uid, &gid);
      /* FIXME: Do we really need this to be specified twice? */
      if (win32_path.isdir ())
	mode |= S_IFDIR;
      if (!set_file_attribute (win32_path.has_acls (), win32_path, 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))
	(DWORD) win32_path &= ~FILE_ATTRIBUTE_READONLY;
      else
	(DWORD) win32_path |= FILE_ATTRIBUTE_READONLY;

      if (S_ISLNK (mode) || S_ISSOCK (mode))
	(DWORD) win32_path |= FILE_ATTRIBUTE_SYSTEM;

      if (!SetFileAttributes (win32_path, win32_path))
	__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);
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    {
      syscall_printf ("-1 = fchmod (%d, 0%o)", fd, mode);
      return -1;
    }

  const char *path = cfd->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);
}

static void
stat64_to_stat32 (struct __stat64 *src, struct __stat32 *dst)
{
  dst->st_dev = src->st_dev;
  dst->st_ino = src->st_ino;
  dst->st_mode = src->st_mode;
  dst->st_nlink = src->st_nlink;
  dst->st_uid = src->st_uid;
  dst->st_gid = src->st_gid;
  dst->st_rdev = src->st_rdev;
  dst->st_size = src->st_size;
  dst->st_atime = src->st_atime;
  dst->st_mtime = src->st_mtime;
  dst->st_ctime = src->st_ctime;
  dst->st_blksize = src->st_blksize;
  dst->st_blocks = src->st_blocks;
}

extern "C" int
fstat64 (int fd, struct __stat64 *buf)
{
  int res;
  sigframe thisframe (mainthread);

  cygheap_fdget cfd (fd);
  if (cfd < 0)
    res = -1;
  else
    {
      path_conv pc (cfd->get_win32_name ());
      memset (buf, 0, sizeof (struct __stat64));
      res = cfd->fstat (buf, &pc);
    }

  syscall_printf ("%d = fstat (%d, %p)", res, fd, buf);
  return res;
}

extern "C" int
_fstat (int fd, struct __stat32 *buf)
{
  struct __stat64 buf64;
  int ret = fstat64 (fd, &buf64);
  if (!ret)
    stat64_to_stat32 (&buf64, buf);
  return ret;
}

/* fsync: P96 6.6.1.1 */
extern "C" int
fsync (int fd)
{
  sigframe thisframe (mainthread);
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    {
      syscall_printf ("-1 = fsync (%d)", fd);
      return -1;
    }

  if (FlushFileBuffers (cfd->get_handle ()) == 0)
    {
      __seterrno ();
      return -1;
    }
  return 0;
}

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

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

/* Cygwin internal */
int __stdcall
stat_worker (const char *name, struct __stat64 *buf, int nofollow,
	     path_conv *pc)
{
  int res = -1;
  path_conv real_path;
  fhandler_base *fh = NULL;

  if (check_null_invalid_struct_errno (buf))
    goto done;

  if (!pc)
    pc = &real_path;

  fh = cygheap->fdtab.build_fhandler_from_name (-1, name, NULL, *pc,
						(nofollow ? PC_SYM_NOFOLLOW
							  : PC_SYM_FOLLOW)
						| PC_FULL, stat_suffixes);

  if (pc->error)
    {
      debug_printf ("got %d error from build_fhandler_from_name", pc->error);
      set_errno (pc->error);
    }
  else
    {
      debug_printf ("(%s, %p, %d, %p), file_attributes %d", name, buf, nofollow,
		    pc, (DWORD) real_path);
      memset (buf, 0, sizeof (*buf));
      res = fh->fstat (buf, pc);
      if (!res)
	{
	  if (!buf->st_ino)
	    buf->st_ino = hash_path_name (0, fh->get_win32_name ());
	  if (!buf->st_dev)
	    buf->st_dev = FHDEVN (fh->get_device ()) << 8 | (fh->get_unit () & 0xff);
	}
    }

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

extern "C" int
stat64 (const char *name, struct __stat64 *buf)
{
  sigframe thisframe (mainthread);
  syscall_printf ("entering");
  return stat_worker (name, buf, 0);
}

extern "C" int
_stat (const char *name, struct __stat32 *buf)
{
  struct __stat64 buf64;
  int ret = stat64 (name, &buf64);
  if (!ret)
    stat64_to_stat32 (&buf64, buf);
  return ret;
}

/* lstat: Provided by SVR4 and 4.3+BSD, POSIX? */
extern "C" int
lstat64 (const char *name, struct __stat64 *buf)
{
  sigframe thisframe (mainthread);
  syscall_printf ("entering");
  return stat_worker (name, buf, 1);
}

/* lstat: Provided by SVR4 and 4.3+BSD, POSIX? */
extern "C" int
cygwin_lstat (const char *name, struct __stat32 *buf)
{
  struct __stat64 buf64;
  int ret = lstat64 (name, &buf64);
  if (!ret)
    stat64_to_stat32 (&buf64, buf);
  return ret;
}

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 __stat64 st;
  int r = stat_worker (fn, &st, 0);
  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;
  char *lnk_suffix = NULL;

  path_conv real_old (oldpath, PC_SYM_NOFOLLOW);

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

  path_conv real_new (newpath, PC_SYM_NOFOLLOW);

  /* Shortcut hack. */
  char new_lnk_buf[MAX_PATH + 5];
  if (real_old.issymlink () && !real_new.error && !real_new.case_clash)
    {
      int len_old = strlen (real_old.get_win32 ());
      if (strcasematch (real_old.get_win32 () + len_old - 4, ".lnk"))
	{
	  strcpy (new_lnk_buf, newpath);
	  strcat (new_lnk_buf, ".lnk");
	  newpath = new_lnk_buf;
	  real_new.check (newpath, PC_SYM_NOFOLLOW);
	}
    }

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

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

  if (!real_old.exists ()) /* file to move doesn't exist */
    {
       syscall_printf ("file to move doesn't exist");
       set_errno (ENOENT);
       return (-1);
    }

  /* Destination file exists and is read only, change that or else
     the rename won't work. */
  if (real_new.has_attribute (FILE_ATTRIBUTE_READONLY))
    SetFileAttributes (real_new, (DWORD) real_new & ~FILE_ATTRIBUTE_READONLY);

  /* Shortcut hack No. 2, part 1 */
  if (!real_old.issymlink () && !real_new.error && real_new.issymlink () &&
      real_new.known_suffix && strcasematch (real_new.known_suffix, ".lnk") &&
      (lnk_suffix = strrchr (real_new.get_win32 (), '.')))
     *lnk_suffix = '\0';

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

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

  if (wincap.has_move_file_ex ())
    {
      if (MoveFileEx (real_old.get_win32 (), real_new.get_win32 (),
		      MOVEFILE_REPLACE_EXISTING))
	res = 0;
    }
  else
    {
      syscall_printf ("try win95 hack");
      for (int i = 0; i < 2; i++)
	{
	  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 ();
      /* Reset R/O attributes if neccessary. */
      if (real_new.has_attribute (FILE_ATTRIBUTE_READONLY))
	SetFileAttributes (real_new, real_new);
    }
  else
    {
      /* make the new file have the permissions of the old one */
      DWORD attr = real_old;
#ifdef HIDDEN_DOT_FILES
      char *c = strrchr (real_old.get_win32 (), '\\');
      if ((c && c[1] == '.') || *real_old.get_win32 () == '.')
	attr &= ~FILE_ATTRIBUTE_HIDDEN;
      c = strrchr (real_new.get_win32 (), '\\');
      if ((c && c[1] == '.') || *real_new.get_win32 () == '.')
	attr |= FILE_ATTRIBUTE_HIDDEN;
#endif
      SetFileAttributes (real_new, attr);

      /* Shortcut hack, No. 2, part 2 */
      /* if the new filename was an existing shortcut, remove it now if the
	 new filename is equal to the shortcut name without .lnk suffix. */
      if (lnk_suffix)
	{
	  *lnk_suffix = '.';
	  DeleteFile (real_new);
	}
    }

  syscall_printf ("%d = rename (%s, %s)", res, (char *) real_old,
		  (char *) real_new);

  return res;
}

extern "C" int
system (const char *cmdstring)
{
  if (check_null_empty_str_errno (cmdstring))
    return -1;

  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" int
setdtablesize (int size)
{
  if (size <= (int)cygheap->fdtab.size || cygheap->fdtab.extend (size - cygheap->fdtab.size))
    return 0;

  return -1;
}

extern "C" int
getdtablesize ()
{
  return cygheap->fdtab.size > OPEN_MAX ? cygheap->fdtab.size : OPEN_MAX;
}

extern "C" size_t
getpagesize ()
{
  if (!system_info.dwPageSize)
    GetSystemInfo (&system_info);
  return (int) system_info.dwPageSize;
}

static int
check_posix_perm (const char *fname, int v)
{
  extern int allow_ntea, allow_ntsec, allow_smbntsec;

  /* Windows 95/98/ME don't support file system security at all. */
  if (!wincap.has_security ())
    return 0;

  /* ntea is ok for supporting permission bits but it doesn't support
     full POSIX security settings. */
  if (v == _PC_POSIX_PERMISSIONS && allow_ntea)
    return 1;

  if (!allow_ntsec)
    return 0;

  char *root = rootdir (strcpy ((char *)alloca (strlen (fname)), fname));

  if (!allow_smbntsec
      && ((root[0] == '\\' && root[1] == '\\')
	  || GetDriveType (root) == DRIVE_REMOTE))
    return 0;

  DWORD vsn, len, flags;
  if (!GetVolumeInformation (root, NULL, 0, &vsn, &len, &flags, NULL, 16))
    {
      __seterrno ();
      return 0;
    }

  return (flags & FS_PERSISTENT_ACLS) ? 1 : 0;
}

/* FIXME: not all values are correct... */
extern "C" long int
fpathconf (int fd, int v)
{
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return -1;
  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 PIPE_BUF;
    case _PC_CHOWN_RESTRICTED:
    case _PC_NO_TRUNC:
      return -1;
    case _PC_VDISABLE:
      if (cfd->is_tty ())
	return -1;
      else
	{
	  set_errno (EBADF);
	  return -1;
	}
    case _PC_POSIX_PERMISSIONS:
    case _PC_POSIX_SECURITY:
      if (cfd->get_device () == FH_DISK)
	return check_posix_perm (cfd->get_win32_name (), v);
      set_errno (EINVAL);
      return -1;
    default:
      set_errno (EINVAL);
      return -1;
    }
}

extern "C" long int
pathconf (const char *file, int v)
{
  switch (v)
    {
    case _PC_PATH_MAX:
      if (check_null_empty_str_errno (file))
	  return -1;
      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 PIPE_BUF;
    case _PC_CHOWN_RESTRICTED:
    case _PC_NO_TRUNC:
      return -1;
    case _PC_VDISABLE:
      return -1;
    case _PC_POSIX_PERMISSIONS:
    case _PC_POSIX_SECURITY:
      {
	path_conv full_path (file, PC_SYM_FOLLOW | PC_FULL);
	if (full_path.error)
	  {
	    set_errno (full_path.error);
	    return -1;
	  }
	if (full_path.is_device ())
	  {
	    set_errno (EINVAL);
	    return -1;
	  }
	return check_posix_perm (full_path, v);
      }
    default:
      set_errno (EINVAL);
      return -1;
    }
}

extern "C" char *
ttyname (int fd)
{
  cygheap_fdget cfd (fd);
  if (cfd < 0 || !cfd->is_tty ())
    {
      return 0;
    }
  return (char *) (cfd->ttyname ());
}

extern "C" char *
ctermid (char *str)
{
  static NO_COPY char buf[16];
  if (str == NULL)
    str = buf;
  if (!real_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 */
    }

  cygheap_fdget cfd (fd, false, false);
  if (cfd < 0)
    {
      syscall_printf (" _cifs: fd not open\n");
      return 0;
    }

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

  if (cfd->get_w_binary () || cfd->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)
{
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return -1;

  return cfd->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)
{
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return -1;
  if (mode != O_BINARY  && mode != O_TEXT && mode != 0)
    {
      set_errno (EINVAL);
      return -1;
    }

  /* 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 (cfd->get_w_binary () && cfd->get_r_binary ())
    res = O_BINARY;
  else if (cfd->get_w_binset () && cfd->get_r_binset ())
    res = O_TEXT;	/* Specifically set O_TEXT */
  else
    res = 0;

  if (!mode)
    cfd->reset_to_open_binmode ();
  else if (mode & O_BINARY)
    {
      cfd->set_w_binary (1);
      cfd->set_r_binary (1);
    }
  else
    {
      cfd->set_w_binary (0);
      cfd->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>, %s) returns %s\n", fd, cfd->get_name (),
		  mode & O_TEXT ? "text" : "binary",
		  res & O_TEXT ? "text" : "binary");
  return res;
}

extern "C" int
ftruncate64 (int fd, __off64_t length)
{
  sigframe thisframe (mainthread);
  int res = -1;

  if (length < 0)
    set_errno (EINVAL);
  else
    {
      cygheap_fdget cfd (fd);
      if (cfd >= 0)
	{
	  HANDLE h = cygheap->fdtab[fd]->get_handle ();

	  if (cfd->get_handle ())
	    {
	      /* remember curr file pointer location */
	      __off64_t prev_loc = cfd->lseek (0, SEEK_CUR);

	      cfd->lseek (length, SEEK_SET);
	      if (!SetEndOfFile (h))
		__seterrno ();
	      else
		res = 0;

	      /* restore original file pointer location */
	      cfd->lseek (prev_loc, SEEK_SET);
	    }
	}
    }

  syscall_printf ("%d = ftruncate (%d, %d)", res, fd, length);
  return res;
}

/* ftruncate: P96 5.6.7.1 */
extern "C" int
ftruncate (int fd, __off32_t length)
{
  return ftruncate64 (fd, (__off64_t)length);
}

/* truncate: Provided by SVR4 and 4.3+BSD.  Not part of POSIX.1 or XPG3 */
extern "C" int
truncate64 (const char *pathname, __off64_t length)
{
  sigframe thisframe (mainthread);
  int fd;
  int res = -1;

  fd = open (pathname, O_RDWR);

  if (fd == -1)
    set_errno (EBADF);
  else
    {
      res = ftruncate64 (fd, length);
      close (fd);
    }
  syscall_printf ("%d = truncate (%s, %d)", res, pathname, length);

  return res;
}

/* truncate: Provided by SVR4 and 4.3+BSD.  Not part of POSIX.1 or XPG3 */
extern "C" int
truncate (const char *pathname, __off32_t length)
{
  return truncate64 (pathname, (__off64_t)length);
}

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

  cygheap_fdget cfd (fd);
  if (cfd >= 0)
    res = (long) cfd->get_handle ();
  else
    res = -1;

  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);
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return -1;
  return statfs (cfd->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);
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return 0;
  return (char *) (cfd->ptsname ());
}

/* FIXME: what is this? */
extern "C" int __declspec(dllexport)
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 (const char *_path, mode_t mode, dev_t dev)
{
  set_errno (ENOSYS);
  return -1;
}

extern "C" int
mkfifo (const char *_path, mode_t mode)
{
  set_errno (ENOSYS);
  return -1;
}

extern struct passwd *internal_getlogin (cygheap_user &user);

/* seteuid: standards? */
extern "C" int
seteuid32 (__uid32_t uid)
{
  if (!wincap.has_security ()) return 0;

  if (uid == ILLEGAL_UID)
    {
      debug_printf ("new euid == illegal euid, nothing happens");
      return 0;
    }

  sigframe thisframe (mainthread);
  DWORD ulen = UNLEN + 1;
  DWORD dlen = INTERNET_MAX_HOST_NAME_LENGTH + 1;
  char orig_username[UNLEN + 1];
  char orig_domain[INTERNET_MAX_HOST_NAME_LENGTH + 1];
  char username[UNLEN + 1];
  char domain[INTERNET_MAX_HOST_NAME_LENGTH + 1];
  cygsid usersid, pgrpsid;
  HANDLE ptok, sav_token;
  BOOL sav_impersonated, sav_token_is_internal_token;
  BOOL process_ok, explicitly_created_token = FALSE;
  struct passwd * pw_new, * pw_cur;
  cygheap_user user;
  PSID origpsid, psid2 = NO_SID;

  debug_printf ("uid: %d myself->gid: %d", uid, myself->gid);

  pw_new = getpwuid32 (uid);
  if (!usersid.getfrompw (pw_new) ||
      (!pgrpsid.getfromgr (getgrgid32 (myself->gid))))
    {
      set_errno (EINVAL);
      return -1;
    }
  /* Save current information */
  sav_token = cygheap->user.token;
  sav_impersonated = cygheap->user.impersonated;
  char *env;
  orig_username[0] = orig_domain[0] = '\0';
  if ((env = getenv ("USERNAME")))
    strlcpy (orig_username, env, sizeof(orig_username));
  if ((env = getenv ("USERDOMAIN")))
    strlcpy (orig_domain, env, sizeof(orig_domain));

  RevertToSelf();
  if (!OpenProcessToken (GetCurrentProcess (),
			 TOKEN_QUERY | TOKEN_ADJUST_DEFAULT, &ptok))
    {
      __seterrno ();
      goto failed;
    }
  /* Verify if the process token is suitable.
     Currently we do not try to differentiate between
	 internal tokens and others */
  process_ok = verify_token(ptok, usersid, pgrpsid);
  debug_printf("Process token %sverified", process_ok?"":"not ");
  if (process_ok)
    {
      if (cygheap->user.token == INVALID_HANDLE_VALUE ||
	  ! cygheap->user.impersonated )
	{
	  CloseHandle (ptok);
	  return 0; /* No change */
	}
      else cygheap->user.impersonated = FALSE;
    }

  if (!process_ok && cygheap->user.token != INVALID_HANDLE_VALUE)
    {
      /* Verify if the current tokem is suitable */
      BOOL token_ok = verify_token (cygheap->user.token, usersid, pgrpsid,
				    & sav_token_is_internal_token);
      debug_printf("Thread token %d %sverified",
		   cygheap->user.token, token_ok?"":"not ");
      if (token_ok)
	{
	  /* Return if current token is valid */
	  if (cygheap->user.impersonated)
	  {
	    CloseHandle (ptok);
	    if (!ImpersonateLoggedOnUser (cygheap->user.token))
	      system_printf ("Impersonating in seteuid failed: %E");
	    return 0; /* No change */
	  }
	}
      else cygheap->user.token = INVALID_HANDLE_VALUE;
    }

  /* Set process def dacl to allow access to impersonated token */
  char dacl_buf[MAX_DACL_LEN(5)];
  if (usersid != (origpsid =  cygheap->user.orig_sid())) psid2 = usersid;
  if (sec_acl ((PACL) dacl_buf, FALSE, origpsid, psid2))
    {
      TOKEN_DEFAULT_DACL tdacl;
      tdacl.DefaultDacl = (PACL) dacl_buf;
      if (!SetTokenInformation (ptok, TokenDefaultDacl,
				&tdacl, sizeof dacl_buf))
	debug_printf ("SetTokenInformation"
		      "(TokenDefaultDacl): %E");
    }
  CloseHandle (ptok);

  if (!process_ok && cygheap->user.token == INVALID_HANDLE_VALUE)
    {
      /* If no impersonation token is available, try to
	 authenticate using NtCreateToken() or subauthentication. */
      cygheap->user.token = create_token (usersid, pgrpsid);
      if (cygheap->user.token != INVALID_HANDLE_VALUE)
	explicitly_created_token = TRUE;
      else
	{
	  /* create_token failed. Try subauthentication. */
	  debug_printf ("create token failed, try subauthentication.");
	  cygheap->user.token = subauth (pw_new);
	  if (cygheap->user.token == INVALID_HANDLE_VALUE) goto failed;
	}
    }

  /* Lookup username and domain before impersonating,
     LookupAccountSid() returns a different answer afterwards. */
  SID_NAME_USE use;
  if (!LookupAccountSid (NULL, usersid, username, &ulen,
			 domain, &dlen, &use))
    {
      debug_printf ("LookupAccountSid (): %E");
      __seterrno ();
      goto failed;
    }
  /* If using the token, set info and impersonate */
  if (! process_ok )
    {
      /* If the token was explicitly created, all information has
	 already been set correctly. */
      if (!explicitly_created_token)
	{
	  /* Try setting owner to same value as user. */
	  if (!SetTokenInformation (cygheap->user.token, TokenOwner,
				    &usersid, sizeof usersid))
	    debug_printf ("SetTokenInformation(user.token, "
			  "TokenOwner): %E");
	  /* Try setting primary group in token to current group */
	  if (!SetTokenInformation (cygheap->user.token,
				    TokenPrimaryGroup,
				    &pgrpsid, sizeof pgrpsid))
	    debug_printf ("SetTokenInformation(user.token, "
			  "TokenPrimaryGroup): %E");
	}
      /* Now try to impersonate. */
      if (!ImpersonateLoggedOnUser (cygheap->user.token))
	{
	  debug_printf ("ImpersonateLoggedOnUser %E");
	  __seterrno ();
	  goto failed;
	}
      cygheap->user.impersonated = TRUE;
    }

  /* 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;
  /* Unsetting these two env vars is necessary to get NetUserGetInfo()
     called in internal_getlogin ().  Otherwise the wrong path is used
     after a user switch, probably. */
  unsetenv ("HOMEDRIVE");
  unsetenv ("HOMEPATH");
  setenv ("USERDOMAIN", domain, 1);
  setenv ("USERNAME", username, 1);
  pw_cur = internal_getlogin (user);
  if (pw_cur == pw_new)
    {
      /* If sav_token was internally created and is replaced, destroy it. */
      if (sav_token != INVALID_HANDLE_VALUE &&
	  sav_token != cygheap->user.token &&
	  sav_token_is_internal_token)
	CloseHandle (sav_token);
      myself->uid = uid;
      cygheap->user = user;
      return 0;
    }
  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);

 failed:
  setenv ("USERNAME", orig_username, 1);
  setenv ("USERDOMAIN", orig_domain, 1);
  cygheap->user.token = sav_token;
  cygheap->user.impersonated = sav_impersonated;
  if ( cygheap->user.token != INVALID_HANDLE_VALUE &&
       cygheap->user.impersonated &&
       !ImpersonateLoggedOnUser (cygheap->user.token))
    system_printf ("Impersonating in seteuid failed: %E");
  return -1;
}

extern "C" int
seteuid (__uid16_t uid)
{
  return seteuid32 (uid16touid32 (uid));
}

/* setuid: POSIX 4.2.2.1 */
extern "C" int
setuid32 (__uid32_t uid)
{
  int ret = seteuid32 (uid);
  if (!ret)
    cygheap->user.real_uid = myself->uid;
  debug_printf ("real: %d, effective: %d", cygheap->user.real_uid, myself->uid);
  return ret;
}

extern "C" int
setuid (__uid16_t uid)
{
  return setuid32 (uid16touid32 (uid));
}

/* setegid: from System V.  */
extern "C" int
setegid32 (__gid32_t gid)
{
  if ((!wincap.has_security ()) ||
      (gid == ILLEGAL_GID))
    return 0;

  sigframe thisframe (mainthread);
  cygsid gsid;
  HANDLE ptok;

  struct __group32 * gr = getgrgid32 (gid);
  if (!gr || gr->gr_gid != gid || !gsid.getfromgr (gr))
    {
      set_errno (EINVAL);
      return -1;
    }
  myself->gid = gid;

  /* If impersonated, update primary group and revert */
  if (cygheap->user.token != INVALID_HANDLE_VALUE
      && cygheap->user.impersonated)
    {
      if (!SetTokenInformation (cygheap->user.token,
				TokenPrimaryGroup,
				&gsid, sizeof gsid))
	debug_printf ("SetTokenInformation(thread, "
		      "TokenPrimaryGroup): %E");
      RevertToSelf ();
    }
  if (!OpenProcessToken (GetCurrentProcess (),
			 TOKEN_ADJUST_DEFAULT,
			 &ptok))
    debug_printf ("OpenProcessToken(): %E\n");
  else
    {
      if (!SetTokenInformation (ptok, TokenPrimaryGroup,
				&gsid, sizeof gsid))
	debug_printf ("SetTokenInformation(process, "
		      "TokenPrimaryGroup): %E");
      CloseHandle (ptok);
    }
  if (cygheap->user.token != INVALID_HANDLE_VALUE
      && cygheap->user.impersonated
      && !ImpersonateLoggedOnUser (cygheap->user.token))
    system_printf ("Impersonating in setegid failed: %E");
  return 0;
}

extern "C" int
setegid (__gid16_t gid)
{
  return setegid32 (gid16togid32 (gid));
}

/* setgid: POSIX 4.2.2.1 */
extern "C" int
setgid32 (__gid32_t gid)
{
  int ret = setegid32 (gid);
  if (!ret)
    cygheap->user.real_gid = myself->gid;
  return ret;
}

extern "C" int
setgid (__gid16_t gid)
{
  int ret = setegid32 (gid16togid32 (gid));
  if (!ret)
    cygheap->user.real_gid = myself->gid;
  return ret;
}

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

  int ret;
  if (path.error)
    ret = -1;
  else if (!path.exists ())
    {
      set_errno (ENOENT);
      ret = -1;
    }
  else if (!path.isdir ())
    {
      set_errno (ENOTDIR);
      ret = -1;
    }
  else
    {
      cygheap->root.set (path.normalized_path, path);
      ret = 0;
    }

  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];
      /* FIXME: utmp file access is not 64 bit clean for now. */
      __off32_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;
}

static int utmp_fd = -2;
static char *utmp_file = (char *) _PATH_UTMP;

static struct utmp utmp_data;

extern "C" void
setutent ()
{
  sigframe thisframe (mainthread);
  if (utmp_fd == -2)
    {
      utmp_fd = _open (utmp_file, O_RDONLY);
    }
  _lseek (utmp_fd, 0, SEEK_SET);
}

extern "C" void
endutent ()
{
  sigframe thisframe (mainthread);
  _close (utmp_fd);
  utmp_fd = -2;
}

extern "C" void
utmpname (_CONST char *file)
{
  sigframe thisframe (mainthread);
  if (check_null_empty_str (file))
    {
      debug_printf ("Invalid file");
      return;
    }
  utmp_file = strdup (file);
  debug_printf ("New UTMP file: %s", utmp_file);
}

extern "C" struct utmp *
getutent ()
{
  sigframe thisframe (mainthread);
  if (utmp_fd == -2)
    setutent ();
  if (_read (utmp_fd, &utmp_data, sizeof (utmp_data)) != sizeof (utmp_data))
    return NULL;
  return &utmp_data;
}

extern "C" struct utmp *
getutid (struct utmp *id)
{
  sigframe thisframe (mainthread);
  if (check_null_invalid_struct_errno (id))
    return NULL;
  while (_read (utmp_fd, &utmp_data, sizeof (utmp_data)) == sizeof (utmp_data))
    {
      switch (id->ut_type)
	{
#if 0 /* Not available in Cygwin. */
	case RUN_LVL:
	case BOOT_TIME:
	case OLD_TIME:
	case NEW_TIME:
	  if (id->ut_type == utmp_data.ut_type)
	    return &utmp_data;
	  break;
#endif
	case INIT_PROCESS:
	case LOGIN_PROCESS:
	case USER_PROCESS:
	case DEAD_PROCESS:
	  if (id->ut_id == utmp_data.ut_id)
	    return &utmp_data;
	  break;
	default:
	  return NULL;
	}
    }
  return NULL;
}

extern "C" struct utmp *
getutline (struct utmp *line)
{
  sigframe thisframe (mainthread);
  if (check_null_invalid_struct_errno (line))
    return NULL;
  while (_read (utmp_fd, &utmp_data, sizeof (utmp_data)) == sizeof (utmp_data))
    {
      if ((utmp_data.ut_type == LOGIN_PROCESS ||
	   utmp_data.ut_type == USER_PROCESS) &&
	  !strncmp (utmp_data.ut_line, line->ut_line,
		    sizeof (utmp_data.ut_line)))
	return &utmp_data;
    }
  return NULL;
}