newlib-cygwin/winsup/cygwin/syscalls.cc

/* syscalls.cc: syscalls

   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 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. */

#define fstat __FOOfstat__
#define lstat __FOOlstat__
#define stat __FOOstat__
#define _close __FOO_close__
#define _lseek __FOO_lseek__
#define _open __FOO_open__
#define _read __FOO_read__
#define _write __FOO_write__
#define _open64 __FOO_open64__
#define _lseek64 __FOO_lseek64__
#define _fstat64 __FOO_fstat64__

#include "winsup.h"
#include <sys/stat.h>
#include <sys/vfs.h> /* needed for statfs */
#include <pwd.h>
#include <grp.h>
#include <stdlib.h>
#include <stdio.h>
#include <process.h>
#include <utmp.h>
#include <sys/uio.h>
#include <limits.h>
#include <unistd.h>
#include <setjmp.h>
#include <winnls.h>
#include <wininet.h>
#include <lmcons.h> /* for UNLEN */
#include <rpc.h>

#undef fstat
#undef lstat
#undef stat

#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 "shared_info.h"
#include "cygheap.h"
#define NEED_VFORK
#include "perthread.h"
#include "pwdgrp.h"
#include "cpuid.h"
#include "registry.h"

#undef _close
#undef _lseek
#undef _open
#undef _read
#undef _write
#undef _open64
#undef _lseek64
#undef _fstat64

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 ();
}

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;
  DWORD devn;
  sigframe thisframe (mainthread);

  path_conv win32_name (ourname, PC_SYM_NOFOLLOW | PC_FULL);

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

  if ((devn = win32_name.get_devn ()) == FH_PROC || devn == FH_REGISTRY
      || devn == FH_PROCESS)
    {
      set_errno (EROFS);
      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");
      set_errno (EPERM);
      goto done;
    }

  bool setattrs;
  if (!((DWORD) win32_name & (FILE_ATTRIBUTE_READONLY | FILE_ATTRIBUTE_SYSTEM)))
    setattrs = false;
  else
    {
      /* Allow us to delete even if read-only */
      setattrs = SetFileAttributes (win32_name,
				    (DWORD) win32_name
				    & ~(FILE_ATTRIBUTE_READONLY
					| FILE_ATTRIBUTE_SYSTEM));
    }
  /* Attempt to use "delete on close" semantics to handle removing
     a file which may be open. */
  HANDLE h;
  h = CreateFile (win32_name, 0, FILE_SHARE_READ, &sec_none_nih,
		  OPEN_EXISTING, FILE_FLAG_DELETE_ON_CLOSE, 0);
  if (h != INVALID_HANDLE_VALUE)
    {
      if (wincap.has_hard_links () && setattrs)
	(void) SetFileAttributes (win32_name, (DWORD) win32_name);
      BOOL res = CloseHandle (h);
      syscall_printf ("%d = CloseHandle (%p)", res, h);
      if (GetFileAttributes (win32_name) == INVALID_FILE_ATTRIBUTES
	  || !win32_name.isremote ())
	{
	  syscall_printf ("CreateFile (FILE_FLAG_DELETE_ON_CLOSE) succeeded");
	  goto ok;
	}
      else
	{
	  syscall_printf ("CreateFile (FILE_FLAG_DELETE_ON_CLOSE) failed");
	  if (setattrs)
	    SetFileAttributes (win32_name, (DWORD) win32_name & ~(FILE_ATTRIBUTE_READONLY | FILE_ATTRIBUTE_SYSTEM));
	}
    }

  /* Try a delete with attributes reset */
  if (DeleteFile (win32_name))
    {
      syscall_printf ("DeleteFile after CreateFile/CloseHandle succeeded");
      goto ok;
    }

  DWORD lasterr;
  lasterr = GetLastError ();

  (void) SetFileAttributes (win32_name, (DWORD) win32_name);

  /* 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;

  /* 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;
}

extern "C" pid_t
_getpid_r (struct _reent *)
{
  return getpid ();
}

/* 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)
{
  vfork_save *vf = vfork_storage.val ();
  /* This is a horrible, horrible kludge */
  if (vf && vf->pid < 0)
    {
      pid_t pid = fork ();
      if (pid > 0)
	{
	  syscall_printf ("longjmping due to vfork");
	  vf->restore_pid (pid);
	}
      /* assuming that fork was successful */
    }

  if (myself->pgid != myself->pid)
    {
      if (myself->ctty >= 0 && fhandler_console::open_fhs <= 0)
	{
	  syscall_printf ("freeing console");
	  FreeConsole ();
	}
      myself->ctty = -1;
      myself->sid = getpid ();
      myself->pgid = getpid ();
      syscall_printf ("sid %d, pgid %d, ctty %d, open_fhs %d", myself->sid,
		      myself->pgid, myself->ctty, fhandler_console::open_fhs);
      return myself->sid;
    }

  set_errno (EPERM);
  return -1;
}

extern "C" pid_t
getsid (pid_t pid)
{
  pid_t res;
  if (!pid)
    res = myself->sid;
  else
    {
      pinfo p (pid);
      if (p)
	res = p->sid;
      else
	{
	  set_errno (ESRCH);
	  res = -1;
	}
    }
  return res;
}

extern "C" ssize_t
read (int fd, void *ptr, size_t len)
{
  const iovec iov =
    {
      iov_base: ptr,
      iov_len: len
    };

  return readv (fd, &iov, 1);
}

extern "C" ssize_t _read (int, void *, size_t)
  __attribute__ ((alias ("read")));

extern "C" ssize_t
write (int fd, const void *ptr, size_t len)
{
  const struct iovec iov =
    {
      iov_base: (void *) ptr,	// const_cast
      iov_len: len
    };

  return writev (fd, &iov, 1);
}

extern "C" ssize_t _write (int fd, const void *ptr, size_t len)
  __attribute__ ((alias ("write")));

extern "C" ssize_t
readv (int fd, const struct iovec *const iov, const int iovcnt)
{
  extern int sigcatchers;
  const int e = get_errno ();

  int res = -1;

  const ssize_t tot = check_iovec_for_read (iov, iovcnt);

  if (tot <= 0)
    {
      res = tot;
      goto done;
    }

  while (1)
    {
      sig_dispatch_pending ();
      sigframe thisframe (mainthread);

      cygheap_fdget cfd (fd);
      if (cfd < 0)
	break;

      if ((cfd->get_flags () & O_ACCMODE) == O_WRONLY)
	{
	  set_errno (EBADF);
	  break;
	}

      DWORD wait = cfd->is_nonblocking () ? 0 : INFINITE;

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

      if (wait && (!cfd->is_slow () || cfd->get_r_no_interrupt ()))
	debug_printf ("no need to call ready_for_read");
      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 ())
	break;

      /* 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 ())
	{
	  res = -1;
	  break;
	}

      if (res > bg_eof)
	{
	  myself->process_state |= PID_TTYIN;
	  if (!cfd.isopen ())
	    {
	      res = -1;
	      break;
	    }
	  res = cfd->readv (iov, iovcnt, tot);
	  myself->process_state &= ~PID_TTYIN;
	}

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

done:
  syscall_printf ("%d = readv (%d, %p, %d), errno %d", res, fd, iov, iovcnt,
		  get_errno ());
  MALLOC_CHECK;
  return res;
}

extern "C" ssize_t
writev (const int fd, const struct iovec *const iov, const int iovcnt)
{
  int res = -1;
  sig_dispatch_pending ();
  const ssize_t tot = check_iovec_for_write (iov, iovcnt);

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

  if (tot <= 0)
    {
      res = tot;
      goto done;
    }

  if ((cfd->get_flags () & O_ACCMODE) == O_RDONLY)
    {
      set_errno (EBADF);
      goto done;
    }

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

  res = cfd->bg_check (SIGTTOU);

  if (res > bg_eof)
    {
      myself->process_state |= PID_TTYOU;
      res = cfd->writev (iov, iovcnt, tot);
      myself->process_state &= ~PID_TTYOU;
    }

done:
  if (fd == 1 || fd == 2)
    paranoid_printf ("%d = write (%d, %p, %d), errno %d",
		     res, fd, iov, iovcnt, get_errno ());
  else
    syscall_printf ("%d = write (%d, %p, %d), errno %d",
		    res, fd, iov, iovcnt, get_errno ());

  MALLOC_CHECK;
  return res;
}

/* _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;
  sig_dispatch_pending ();
  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" int _open (const char *, int flags, ...)
  __attribute__ ((alias ("open")));

extern "C" int _open64 (const char *, int flags, ...)
  __attribute__ ((alias ("open")));

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" int _lseek64 (int fd, _off64_t pos, int dir)
  __attribute__ ((alias ("lseek64")));

extern "C" _off_t
lseek (int fd, _off_t pos, int dir)
{
  return lseek64 (fd, (_off64_t) pos, dir);
}

extern "C" _off_t _lseek (int, _off_t, int)
  __attribute__ ((alias ("lseek")));

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
    {
      res = cfd->close ();
      cfd.release ();
    }

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

extern "C" int _close (int) __attribute__ ((alias ("close")));

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);
  extern BOOL allow_winsymlinks;

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

  /* Shortcut hack. */
  char new_lnk_buf[MAX_PATH + 5];
  if (allow_winsymlinks && real_a.is_lnk_symlink () && !real_b.case_clash)
    {
      strcpy (new_lnk_buf, b);
      strcat (new_lnk_buf, ".lnk");
      b = new_lnk_buf;
      real_b.check (b, PC_SYM_NOFOLLOW | PC_FULL);
    }
  /* Try to make hard link first on Windows NT */
  if (wincap.has_hard_links ())
    {
      if (CreateHardLinkA (real_b, real_a, NULL))
	goto success;

      HANDLE hFileSource;

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

      BOOL bSuccess;

      hFileSource = CreateFile (real_a, 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;
	}

      cbPathLen = sys_mbstowcs (wbuf, real_b, 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;

      lpContext = NULL;
      /* 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;

    success:
      res = 0;
      if (!allow_winsymlinks && real_a.is_lnk_symlink ())
	SetFileAttributes (real_b, (DWORD) real_a
			           | FILE_ATTRIBUTE_SYSTEM
				   | FILE_ATTRIBUTE_READONLY);

      goto done;
    }
docopy:
  /* do this with a copy */
  if (CopyFileA (real_a, real_b, 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;

  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 () && !win32_path.issocket ())
	{
	  res = 0;
	  goto done;
	}

      mode_t attrib = 0;
      if (win32_path.isdir ())
	attrib |= S_IFDIR;
      res = get_file_attribute (win32_path.has_acls (),
				win32_path.get_win32 (),
				&attrib);
      if (!res)
	 res = set_file_attribute (win32_path.has_acls (), win32_path, uid,
				   gid, attrib);
      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,
		       uid16touid32 (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,
		       uid16touid32 (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, uid16touid32 (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 () && !win32_path.issocket ())
    {
      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);

      if (win32_path.isdir ())
	mode |= S_IFDIR;
      if (!set_file_attribute (win32_path.has_acls (), win32_path,
			       ILLEGAL_UID, ILLEGAL_GID, mode)
	  && 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 (!win32_path.is_lnk_symlink () && S_ISLNK (mode) || S_ISSOCK (mode))
	(DWORD) win32_path |= FILE_ATTRIBUTE_SYSTEM;

      if (!SetFileAttributes (win32_path, win32_path))
	__seterrno ();
      else if (!allow_ntsec)
	/* Correct NTFS security attributes have higher priority */
	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 >> 8) & 0xff00) | (src->st_dev & 0xff);
  dst->st_ino = ((unsigned) (src->st_ino >> 32)) | (unsigned) 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 >> 8) & 0xff00) | (src->st_rdev & 0xff);
  dst->st_size = src->st_size;
  dst->st_atim = src->st_atim;
  dst->st_mtim = src->st_mtim;
  dst->st_ctim = src->st_ctim;
  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_name (), PC_SYM_NOFOLLOW);
      memset (buf, 0, sizeof (struct __stat64));
      res = cfd->fstat (buf, &pc);
      if (!res && cfd->get_device () != FH_SOCKET)
	{
	  if (!buf->st_ino)
	    buf->st_ino = hash_path_name (0, cfd->get_win32_name ());
	  if (!buf->st_dev)
	    buf->st_dev = (cfd->get_device () << 16) | cfd->get_unit ();
	  if (!buf->st_rdev)
	    buf->st_rdev = buf->st_dev;
	}
    }

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

extern "C" int
_fstat64_r (struct _reent *ptr, int fd, struct __stat64 *buf)
{
  int ret;

  set_errno (0);
  if ((ret = fstat64 (fd, buf)) == -1 && get_errno () != 0)
    ptr->_errno = get_errno ();
  return ret;
}

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;
}

extern "C" int
_fstat_r (struct _reent *ptr, int fd, struct __stat32 *buf)
{
  int ret;

  set_errno (0);
  if ((ret = fstat (fd, buf)) == -1 && get_errno () != 0)
    ptr->_errno = get_errno ();
  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 && fh->get_device () != FH_SOCKET)
	{
	  if (!buf->st_ino)
	    buf->st_ino = hash_path_name (0, fh->get_win32_name ());
	  if (!buf->st_dev)
	    buf->st_dev = (fh->get_device () << 16) | fh->get_unit ();
	  if (!buf->st_rdev)
	    buf->st_rdev = buf->st_dev;
	}
    }

 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
_stat64_r (struct _reent *ptr, const char *name, struct __stat64 *buf)
{
  int ret;

  set_errno (0);
  if ((ret = stat64 (name, buf)) == -1 && get_errno () != 0)
    ptr->_errno = get_errno ();
  return ret;
}

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;
}

extern "C" int
_stat_r (struct _reent *ptr, const char *name, struct __stat32 *buf)
{
  int ret;

  set_errno (0);
  if ((ret = stat (name, buf)) == -1 && get_errno () != 0)
    ptr->_errno = get_errno ();
  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
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 "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;
    }

  path_conv real_path (fn, PC_SYM_FOLLOW | PC_FULL, stat_suffixes);
  if (real_path.error)
    {
      set_errno (real_path.error);
      return -1;
    }

  if (!real_path.exists ())
    {
      set_errno (ENOENT);
      return -1;
    }

  if (!(flags & (R_OK | W_OK | X_OK)))
    return 0;

  if (real_path.has_attribute (FILE_ATTRIBUTE_READONLY) && (flags & W_OK))
    {
      set_errno (EACCES);
      return -1;
    }

  if (real_path.has_acls () && allow_ntsec)
    return check_file_access (real_path, 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.is_lnk_symlink () && !real_new.error && !real_new.case_clash)
    {
      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.is_lnk_symlink ()
      && (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;
}

struct system_cleanup_args
{
  _sig_func_ptr oldint, oldquit;
  sigset_t old_mask;
};

static void system_cleanup (void *args)
{
  struct system_cleanup_args *cleanup_args = (struct system_cleanup_args *) args;

  signal (SIGINT, cleanup_args->oldint);
  signal (SIGQUIT, cleanup_args->oldquit);
  (void) sigprocmask (SIG_SETMASK, &cleanup_args->old_mask, 0);
}

extern "C" int
system (const char *cmdstring)
{
  pthread_testcancel ();

  if (check_null_empty_str_errno (cmdstring))
    return -1;

  sigframe thisframe (mainthread);
  int res;
  const char* command[4];
  struct system_cleanup_args cleanup_args;
  sigset_t child_block;

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

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

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

  pthread_cleanup_push (system_cleanup, (void *) &cleanup_args);

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

  pthread_cleanup_pop (1);

  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)
{
  /* 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)", fd);
  if (CYGWIN_VERSION_OLD_STDIO_CRLF_HANDLING)
    {
      syscall_printf (" _cifs: old API");
      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");
      return 0;
    }

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

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

  syscall_printf ("_cygwin_istext_for_stdio says yes");
  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",
		 f->_flags & __SCLE ? "text" : "raw",
		 setmode_mode & O_TEXT ? "text" : "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
    cfd->set_flags ((cfd->get_flags () & ~(O_TEXT | O_BINARY)) | mode);

  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>, %p) returns %s", fd, cfd->get_name (),
		  mode, 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, _off_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, _off_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);

  const char *root = full_path.root_dir();

  syscall_printf ("statfs %s", root);

  /* GetDiskFreeSpaceEx must be called before GetDiskFreeSpace on
     WinME, to avoid the MS KB 314417 bug */
  ULARGE_INTEGER availb, freeb, totalb;
  BOOL status = GetDiskFreeSpaceEx (root, &availb, &totalb, &freeb);

  DWORD spc, bps, availc, freec, totalc;

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

  if (status)
    {
      availc = availb.QuadPart / (spc*bps);
      totalc = totalb.QuadPart / (spc*bps);
      freec = freeb.QuadPart / (spc*bps);
    }
  else
    availc = freec;

  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_bavail = availc;
  sfs->f_bfree = 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
mknod32 (const char *_path, mode_t mode, __dev32_t dev)
{
  set_errno (ENOSYS);
  return -1;
}

extern "C" int
mknod (const char *_path, mode_t mode, __dev16_t dev)
{
  return mknod32 (_path, mode, (__dev32_t) dev);
}

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

/* seteuid: standards? */
extern "C" int
seteuid32 (__uid32_t uid)
{
  debug_printf ("uid: %u myself->gid: %u", uid, myself->gid);

  if (uid == myself->uid && !cygheap->user.groups.ischanged)
    {
      debug_printf ("Nothing happens");
      return 0;
    }

  sigframe thisframe (mainthread);
  cygsid usersid;
  user_groups &groups = cygheap->user.groups;
  HANDLE ptok, new_token = INVALID_HANDLE_VALUE;
  struct passwd * pw_new;
  PSID origpsid, psid2 = NO_SID;
  BOOL token_is_internal;

  pw_new = internal_getpwuid (uid);
  if (!wincap.has_security () && pw_new)
    goto success_9x;
  if (!usersid.getfrompw (pw_new))
    {
      set_errno (EINVAL);
      return -1;
    }

  RevertToSelf ();
  if (!OpenProcessToken (hMainProc, TOKEN_QUERY | TOKEN_ADJUST_DEFAULT, &ptok))
    {
      __seterrno ();
      goto failed_ptok;;
    }

  /* Verify if the process token is suitable. */
  if (verify_token (ptok, usersid, groups))
    new_token = ptok;
  /* Verify if the external token is suitable */
  else if (cygheap->user.external_token != INVALID_HANDLE_VALUE
	   && verify_token (cygheap->user.external_token, usersid, groups))
    new_token = cygheap->user.external_token;
  /* Verify if the current token (internal or former external) is suitable */
  else if (cygheap->user.current_token != INVALID_HANDLE_VALUE
	   && cygheap->user.current_token != cygheap->user.external_token
	   && verify_token (cygheap->user.current_token, usersid, groups,
			    &token_is_internal))
    new_token = cygheap->user.current_token;
  /* Verify if the internal token is suitable */
  else if (cygheap->user.internal_token != INVALID_HANDLE_VALUE
	   && cygheap->user.internal_token != cygheap->user.current_token
	   && verify_token (cygheap->user.internal_token, usersid, groups,
			    &token_is_internal))
    new_token = cygheap->user.internal_token;

  debug_printf ("Found token %d", new_token);

  /* Set process def dacl to allow access to impersonated token */
  if (cygheap->user.current_token != new_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");
	}
    }

  /* If no impersonation token is available, try to
     authenticate using NtCreateToken () or subauthentication. */
  if (new_token == INVALID_HANDLE_VALUE)
    {
      new_token = create_token (usersid, groups, pw_new);
      if (new_token == INVALID_HANDLE_VALUE)
	{
	  /* create_token failed. Try subauthentication. */
	  debug_printf ("create token failed, try subauthentication.");
	  new_token = subauth (pw_new);
	  if (new_token == INVALID_HANDLE_VALUE)
	    goto failed;
	}
      /* Keep at most one internal token */
      if (cygheap->user.internal_token != INVALID_HANDLE_VALUE)
	CloseHandle (cygheap->user.internal_token);
      cygheap->user.internal_token = new_token;
    }
  else if (new_token != ptok)
    {
      /* Try setting owner to same value as user. */
      if (!SetTokenInformation (new_token, TokenOwner,
				&usersid, sizeof usersid))
	debug_printf ("SetTokenInformation(user.token, "
		      "TokenOwner): %E");
      /* Try setting primary group in token to current group */
      if (!SetTokenInformation (new_token,
				TokenPrimaryGroup,
				&groups.pgsid, sizeof (cygsid)))
	debug_printf ("SetTokenInformation(user.token, "
		      "TokenPrimaryGroup): %E");
    }

  CloseHandle (ptok);
  cygheap->user.set_sid (usersid);
  cygheap->user.current_token = new_token == ptok ? INVALID_HANDLE_VALUE
						  : new_token;
  cygheap->user.reimpersonate ();
success_9x:
  cygheap->user.set_name (pw_new->pw_name);
  myself->uid = uid;
  groups.ischanged = FALSE;
  return 0;

failed:
  CloseHandle (ptok);
failed_ptok:
  cygheap->user.reimpersonate ();
  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));
}

extern "C" int
setreuid32 (__uid32_t ruid, __uid32_t euid)
{
  int ret = 0;
  bool tried = false;
  __uid32_t old_euid = myself->uid;

  if (ruid != ILLEGAL_UID && cygheap->user.real_uid != ruid && euid != ruid)
    tried = !(ret = seteuid32 (ruid));
  if (!ret && euid != ILLEGAL_UID)
    ret = seteuid32 (euid);
  if (tried && (ret || euid == ILLEGAL_UID) && seteuid32 (old_euid))
    system_printf ("Cannot restore original euid %u", old_euid);
  if (!ret && ruid != ILLEGAL_UID)
    cygheap->user.real_uid = ruid;
  debug_printf ("real: %u, effective: %u", cygheap->user.real_uid, myself->uid);
  return ret;
}

extern "C" int
setreuid (__uid16_t ruid, __uid16_t euid)
{
  return setreuid32 (uid16touid32 (ruid), uid16touid32 (euid));
}

/* setegid: from System V.  */
extern "C" int
setegid32 (__gid32_t gid)
{
  debug_printf ("new egid: %u current: %u", gid, myself->gid);

  if (gid == myself->gid || !wincap.has_security ())
    {
      myself->gid = gid;
      return 0;
    }

  sigframe thisframe (mainthread);
  user_groups * groups = &cygheap->user.groups;
  cygsid gsid;
  HANDLE ptok;
  struct __group32 * gr = internal_getgrgid (gid);

  if (!gsid.getfromgr (gr))
    {
      set_errno (EINVAL);
      return -1;
    }
  myself->gid = gid;

  groups->update_pgrp (gsid);
  /* If impersonated, update primary group and revert */
  if (cygheap->user.issetuid ())
    {
      if (!SetTokenInformation (cygheap->user.token (),
				TokenPrimaryGroup,
				&gsid, sizeof gsid))
	debug_printf ("SetTokenInformation(thread, "
		      "TokenPrimaryGroup): %E");
      RevertToSelf ();
    }
  if (!OpenProcessToken (hMainProc, TOKEN_ADJUST_DEFAULT, &ptok))
    debug_printf ("OpenProcessToken(): %E");
  else
    {
      if (!SetTokenInformation (ptok, TokenPrimaryGroup,
				&gsid, sizeof gsid))
	debug_printf ("SetTokenInformation(process, "
		      "TokenPrimaryGroup): %E");
      CloseHandle (ptok);
    }
  if (cygheap->user.issetuid ()
      && !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;
}

extern "C" int
setregid32 (__gid32_t rgid, __gid32_t egid)
{
  int ret = 0;
  bool tried = false;
  __gid32_t old_egid = myself->gid;

  if (rgid != ILLEGAL_GID && cygheap->user.real_gid != rgid && egid != rgid)
    tried = !(ret = setegid32 (rgid));
  if (!ret && egid != ILLEGAL_GID)
    ret = setegid32 (egid);
  if (tried && (ret || egid == ILLEGAL_GID) && setegid32 (old_egid))
    system_printf ("Cannot restore original egid %u", old_egid);
  if (!ret && rgid != ILLEGAL_GID)
    cygheap->user.real_gid = rgid;
  debug_printf ("real: %u, effective: %u", cygheap->user.real_gid, myself->gid);
  return ret;
}

extern "C" int
setregid (__gid16_t rgid, __gid16_t egid)
{
  return setregid32 (gid16togid32 (rgid), gid16togid32 (egid));
}

/* 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;

  pututline (ut);
  endutent ();
  /* Writing to wtmp must be atomic to prevent mixed up data. */
  char mutex_name[MAX_PATH];
  HANDLE mutex = CreateMutex (NULL, FALSE,
			      shared_name (mutex_name, "wtmp_mutex", 0));
  if (mutex)
    while (WaitForSingleObject (mutex, INFINITE) == WAIT_ABANDONED)
      ;
  if ((fd = open (_PATH_WTMP, O_WRONLY | O_APPEND | O_BINARY, 0)) >= 0)
    {
      write (fd, ut, sizeof *ut);
      close (fd);
    }
  if (mutex)
    {
      ReleaseMutex (mutex);
      CloseHandle (mutex);
    }
}

extern "C" int
logout (char *line)
{
  sigframe thisframe (mainthread);
  struct utmp ut_buf, *ut;

  memset (&ut_buf, 0, sizeof ut_buf);
  strncpy (ut_buf.ut_line, line, sizeof ut_buf.ut_line);
  setutent ();
  ut = getutline (&ut_buf);

  if (ut)
    {
      int fd;

      ut->ut_type = DEAD_PROCESS;
      memset (ut->ut_user, 0, sizeof ut->ut_user);
      time (&ut->ut_time);
      /* Writing to wtmp must be atomic to prevent mixed up data. */
      char mutex_name[MAX_PATH];
      HANDLE mutex = CreateMutex (NULL, FALSE,
				  shared_name (mutex_name, "wtmp_mutex", 0));
      if (mutex)
	while (WaitForSingleObject (mutex, INFINITE) == WAIT_ABANDONED)
	  ;
      if ((fd = open (_PATH_WTMP, O_WRONLY | O_APPEND | O_BINARY, 0)) >= 0)
	{
	  write (fd, &ut_buf, sizeof ut_buf);
	  debug_printf ("set logout time for %s", line);
	  close (fd);
	}
      if (mutex)
	{
	  ReleaseMutex (mutex);
	  CloseHandle (mutex);
	}
      memset (ut->ut_line, 0, sizeof ut_buf.ut_line);
      ut->ut_time = 0;
      pututline (ut);
      endutent ();
    }
  return 1;
}

static int utmp_fd = -1;
static bool utmp_readonly = false;
static char *utmp_file = (char *) _PATH_UTMP;

static void
internal_setutent (bool force_readwrite)
{
  sigframe thisframe (mainthread);
  if (force_readwrite && utmp_readonly)
    endutent ();
  if (utmp_fd < 0)
    {
      utmp_fd = open (utmp_file, O_RDWR | O_BINARY);
      /* If open fails, we assume an unprivileged process (who?).  In this
	 case we try again for reading only unless the process calls
	 pututline() (==force_readwrite) in which case opening just fails. */
      if (utmp_fd < 0 && !force_readwrite)
	{
	  utmp_fd = open (utmp_file, O_RDONLY | O_BINARY);
	  if (utmp_fd >= 0)
	    utmp_readonly = true;
	}
    }
  else
    lseek (utmp_fd, 0, SEEK_SET);
}

extern "C" void
setutent ()
{
  internal_setutent (false);
}

extern "C" void
endutent ()
{
  sigframe thisframe (mainthread);
  if (utmp_fd >= 0)
    {
      close (utmp_fd);
      utmp_fd = -1;
      utmp_readonly = false;
    }
}

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

/* Note: do not make NO_COPY */
static struct utmp utmp_data_buf[16];
static unsigned utix = 0;
#define nutdbuf (sizeof (utmp_data_buf) / sizeof (utmp_data_buf[0]))
#define utmp_data ({ \
  if (utix > nutdbuf) \
    utix = 0; \
  utmp_data_buf + utix++; \
})

extern "C" struct utmp *
getutent ()
{
  sigframe thisframe (mainthread);
  if (utmp_fd < 0)
    {
      internal_setutent (false);
      if (utmp_fd < 0)
	return NULL;
    }

  utmp *ut = utmp_data;
  if (read (utmp_fd, ut, sizeof *ut) != sizeof *ut)
    return NULL;
  return ut;
}

extern "C" struct utmp *
getutid (struct utmp *id)
{
  sigframe thisframe (mainthread);
  if (check_null_invalid_struct_errno (id))
    return NULL;
  if (utmp_fd < 0)
    {
      internal_setutent (false);
      if (utmp_fd < 0)
	return NULL;
    }

  utmp *ut = utmp_data;
  while (read (utmp_fd, ut, sizeof *ut) == sizeof *ut)
    {
      switch (id->ut_type)
	{
	case RUN_LVL:
	case BOOT_TIME:
	case OLD_TIME:
	case NEW_TIME:
	  if (id->ut_type == ut->ut_type)
	    return ut;
	  break;
	case INIT_PROCESS:
	case LOGIN_PROCESS:
	case USER_PROCESS:
	case DEAD_PROCESS:
	   if (strncmp (id->ut_id, ut->ut_id, UT_IDLEN) == 0)
	    return ut;
	  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;
  if (utmp_fd < 0)
    {
      internal_setutent (false);
      if (utmp_fd < 0)
	return NULL;
    }

  utmp *ut = utmp_data;
  while (read (utmp_fd, ut, sizeof *ut) == sizeof *ut)
    if ((ut->ut_type == LOGIN_PROCESS ||
	 ut->ut_type == USER_PROCESS) &&
	!strncmp (ut->ut_line, line->ut_line, sizeof (ut->ut_line)))
      return ut;

  return NULL;
}

extern "C" void
pututline (struct utmp *ut)
{
  sigframe thisframe (mainthread);
  if (check_null_invalid_struct (ut))
    return;
  internal_setutent (true);
  if (utmp_fd < 0)
    {
      debug_printf ("error: utmp_fd %d", utmp_fd);
      return;
    }
  debug_printf ("ut->ut_type %d, ut->ut_pid %d, ut->ut_line '%s', ut->ut_id '%s'\n",
		ut->ut_type, ut->ut_pid, ut->ut_line, ut->ut_id);
  debug_printf ("ut->ut_user '%s', ut->ut_host '%s'\n",
		ut->ut_user, ut->ut_host);
  /* Read/write to utmp must be atomic to prevent overriding data
     by concurrent processes. */
  char mutex_name[MAX_PATH];
  HANDLE mutex = CreateMutex (NULL, FALSE,
			      shared_name (mutex_name, "utmp_mutex", 0));
  if (mutex)
    while (WaitForSingleObject (mutex, INFINITE) == WAIT_ABANDONED)
      ;
  struct utmp *u;
  if ((u = getutid (ut)))
    lseek (utmp_fd, -sizeof *ut, SEEK_CUR);
  else
    lseek (utmp_fd, 0, SEEK_END);
  write (utmp_fd, ut, sizeof *ut);
  if (mutex)
    {
      ReleaseMutex (mutex);
      CloseHandle (mutex);
    }
}

extern "C"
long gethostid(void)
{
  unsigned data[13] = {0x92895012,
		       0x10293412,
		       0x29602018,
		       0x81928167,
		       0x34601329,
		       0x75630198,
		       0x89860395,
		       0x62897564,
		       0x00194362,
		       0x20548593,
		       0x96839102,
		       0x12219854,
		       0x00290012};

  bool has_cpuid = false;
  sigframe thisframe (mainthread);

  DWORD opmask = SetThreadAffinityMask (GetCurrentThread (), 1);
  if (!opmask)
    debug_printf ("SetThreadAffinityMask to 1 failed, %E");

  if (!can_set_flag (0x00040000))
    debug_printf ("386 processor - no cpuid");
  else
    {
      debug_printf ("486 processor");
      if (can_set_flag (0x00200000))
	{
	  debug_printf ("processor supports CPUID instruction");
	  has_cpuid = true;
	}
      else
	debug_printf ("processor does not support CPUID instruction");
    }
  if (has_cpuid)
    {
      unsigned maxf, unused[3];
      cpuid (&maxf, &unused[0], &unused[1], &unused[2], 0);
      maxf &= 0xffff;
      if (maxf >= 1)
	{
	  unsigned features;
	  cpuid (&data[0], &unused[0], &unused[1], &features, 1);
	  if (features & (1 << 18))
	    {
	      debug_printf ("processor has psn");
	      if (maxf >= 3)
		{
		  cpuid (&unused[0], &unused[1], &data[1], &data[2], 3);
		  debug_printf ("Processor PSN: %04x-%04x-%04x-%04x-%04x-%04x",
				data[0] >> 16, data[0] & 0xffff, data[2] >> 16, data[2] & 0xffff, data[1] >> 16, data[1] & 0xffff);
		}
	    }
	  else
	    debug_printf ("processor does not have psn");
	}
    }

  UUID Uuid;
  RPC_STATUS status = UuidCreateSequential (&Uuid);
  if (GetLastError () == ERROR_PROC_NOT_FOUND)
    status = UuidCreate (&Uuid);
  if (status == RPC_S_OK)
    {
      data[4] = *(unsigned *)&Uuid.Data4[2];
      data[5] = *(unsigned short *)&Uuid.Data4[6];
      // Unfortunately Windows will sometimes pick a virtual Ethernet card
      // e.g. VMWare Virtual Ethernet Adaptor
      debug_printf ("MAC address of first Ethernet card: %02x:%02x:%02x:%02x:%02x:%02x",
		    Uuid.Data4[2], Uuid.Data4[3], Uuid.Data4[4],
		    Uuid.Data4[5], Uuid.Data4[6], Uuid.Data4[7]);
    }
  else
    {
      debug_printf ("no Ethernet card installed");
    }

  reg_key key (HKEY_LOCAL_MACHINE, KEY_READ, "SOFTWARE", "Microsoft", "Windows", "CurrentVersion", NULL);
  key.get_string ("ProductId", (char *)&data[6], 24, "00000-000-0000000-00000");
  debug_printf ("Windows Product ID: %s", (char *)&data[6]);

  GetDiskFreeSpaceEx ("C:\\", NULL, (PULARGE_INTEGER) &data[11], NULL);
  if (GetLastError () == ERROR_PROC_NOT_FOUND)
    GetDiskFreeSpace ("C:\\", NULL, NULL, NULL, (DWORD *)&data[11]);

  debug_printf ("hostid entropy: %08x %08x %08x %08x "
				"%08x %08x %08x %08x "
				"%08x %08x %08x %08x "
				"%08x",
				data[0], data[1],
				data[2], data[3],
				data[4], data[5],
				data[6], data[7],
				data[8], data[9],
				data[10], data[11],
				data[12]);

  long hostid = 0x40291372;
  // a random hashing algorithm
  // dependancy on md5 is probably too costly
  for (int i=0;i<13;i++)
    hostid ^= ((data[i] << (i << 2)) | (data[i] >> (32 - (i << 2))));

  if (opmask && !SetThreadAffinityMask (GetCurrentThread (), opmask))
    debug_printf ("SetThreadAffinityMask to %p failed, %E", opmask);

  debug_printf ("hostid: %08x", hostid);

  return hostid;
}