newlib/winsup/cygwin/syscalls.cc

/* syscalls.cc: syscalls

   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   2005, 2006, 2007, 2008 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__
#define pread __FOO_pread
#define pwrite __FOO_pwrite

#include "winsup.h"
#include <sys/stat.h>
#include <sys/vfs.h> /* needed for statfs */
#include <sys/statvfs.h> /* needed for statvfs */
#include <pwd.h>
#include <grp.h>
#include <stdlib.h>
#include <stdio.h>
#include <process.h>
#include <utmp.h>
#include <utmpx.h>
#include <sys/uio.h>
#include <errno.h>
#include <ctype.h>
#include <limits.h>
#include <unistd.h>
#include <setjmp.h>
#include <sys/wait.h>
#include <winnls.h>
#include <wininet.h>
#include <winioctl.h>
#include <lmcons.h> /* for UNLEN */
#include <rpc.h>
#include <shellapi.h>
#include <ntdef.h>
#include "ntdll.h"

#undef fstat
#undef lstat
#undef stat
#undef pread
#undef pwrite

#include <cygwin/version.h>
#include <sys/cygwin.h>
#include "cygerrno.h"
#include "perprocess.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "sigproc.h"
#include "pinfo.h"
#include "shared_info.h"
#include "cygheap.h"
#include "pwdgrp.h"
#include "cpuid.h"
#include "registry.h"
#include "environ.h"

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

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

bool transparent_exe = false;

SYSTEM_INFO system_info;

static int __stdcall mknod_worker (const char *, mode_t, mode_t, _major_t,
				   _minor_t);

/* 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 (bool norelease)
{
  cygheap->fdtab.lock ();

  semaphore::terminate ();

  fhandler_base *fh;
  HANDLE h = NULL;

  for (int i = 0; i < (int) cygheap->fdtab.size; i++)
    if ((fh = cygheap->fdtab[i]) != NULL)
      {
#ifdef DEBUGGING
	debug_printf ("closing fd %d", i);
#endif
	if (i == 2)
	  DuplicateHandle (GetCurrentProcess (), fh->get_output_handle (), GetCurrentProcess (), &h, 0, false,
			   DUPLICATE_SAME_ACCESS);
	fh->close ();
	if (!norelease)
	  cygheap->fdtab.release (i);
      }

  if (!hExeced && cygheap->ctty)
    cygheap->close_ctty ();

  if (h)
    SetStdHandle (STD_ERROR_HANDLE, h);
  cygheap->fdtab.unlock ();
}

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

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

static char desktop_ini[] =
  "[.ShellClassInfo]\r\nCLSID={645FF040-5081-101B-9F08-00AA002F954E}\r\n";
static BYTE info2[] =
{
  0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x20, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

static void
try_to_bin (path_conv &win32_path, HANDLE h)
{
  NTSTATUS status;
  OBJECT_ATTRIBUTES attr;
  IO_STATUS_BLOCK io;
  HANDLE rootdir = NULL, recyclerdir = NULL;
  USHORT recycler_base_len = 0, recycler_user_len = 0;
  UNICODE_STRING root, recycler, fname;
  WCHAR recyclerbuf[NAME_MAX + 1]; /* Enough for recycler + SID + filename */
  PFILE_NAME_INFORMATION pfni;
  PFILE_INTERNAL_INFORMATION pfii;
  PFILE_RENAME_INFORMATION pfri;
  BYTE infobuf[sizeof (FILE_NAME_INFORMATION ) + 32767 * sizeof (WCHAR)];

  pfni = (PFILE_NAME_INFORMATION) infobuf;
  status = NtQueryInformationFile (h, &io, pfni, sizeof infobuf,
				   FileNameInformation);
  if (!NT_SUCCESS (status))
    {
      debug_printf ("NtQueryInformationFile (FileNameInformation) failed, %08x",
		    status);
      goto out;
    }
  /* The filename could change, the parent dir not.  So we split both paths
     and take the prefix.  However, there are two special cases:
     - The handle refers to the root dir of the volume.
     - The handle refers to the recycler or a subdir.
     Both cases are handled by just returning and not even trying to move
     them into the recycler. */
  if (pfni->FileNameLength == 2) /* root dir. */
    goto out;
  /* Initialize recycler path. */
  RtlInitEmptyUnicodeString (&recycler, recyclerbuf, sizeof recyclerbuf);
  if (wincap.has_recycle_dot_bin ())	/* NTFS and FAT since Vista */
    RtlAppendUnicodeToString (&recycler, L"\\$Recycle.Bin\\");
  else if (win32_path.fs_is_ntfs ())	/* NTFS up to 2K3 */
    RtlAppendUnicodeToString (&recycler, L"\\RECYCLER\\");
  else if (win32_path.fs_is_fat ())	/* FAT up to 2K3 */
    RtlAppendUnicodeToString (&recycler, L"\\Recycled\\");
  else
    goto out;
  /* Is the file a subdir of the recycler? */
  RtlInitCountedUnicodeString(&fname, pfni->FileName, pfni->FileNameLength);
  if (RtlEqualUnicodePathPrefix (&fname, recycler.Buffer, TRUE))
    goto out;
  /* Is fname the recycler?  Temporarily hide trailing backslash. */
  recycler.Length -= sizeof (WCHAR);
  if (RtlEqualUnicodeString (&fname, &recycler, TRUE))
    goto out;

  /* Create root dir path from file name information. */
  RtlSplitUnicodePath (&fname, &fname, NULL);
  RtlSplitUnicodePath (win32_path.get_nt_native_path (), &root, NULL);
  root.Length -= fname.Length - sizeof (WCHAR);

  /* Open root directory. */
  InitializeObjectAttributes (&attr, &root, OBJ_CASE_INSENSITIVE, NULL, NULL);
  status = NtOpenFile (&rootdir, FILE_TRAVERSE, &attr, &io,
		       FILE_SHARE_VALID_FLAGS, FILE_OPEN_FOR_BACKUP_INTENT);
  if (!NT_SUCCESS (status))
    {
      debug_printf ("NtOpenFile (%S) failed, %08x", &root, status);
      goto out;
    }

  /* Strip leading backslash */
  ++recycler.Buffer;
  recycler.Length -= sizeof (WCHAR);
  /* Store length of recycler base dir, should it be necessary to create it. */
  recycler_base_len = recycler.Length;
  /* On NTFS the recycler dir contains user specific subdirs, which are the
     actual recycle bins per user.  The name if this dir is the string
     representation of the user SID. */
  if (win32_path.fs_is_ntfs ())
    {
      UNICODE_STRING sid;
      WCHAR sidbuf[128];
      /* Unhide trailing backslash. */
      recycler.Length += sizeof (WCHAR);
      RtlInitEmptyUnicodeString (&sid, sidbuf, sizeof sidbuf);
      /* In contrast to what MSDN claims, this function is already available
	 since NT4. */
      RtlConvertSidToUnicodeString (&sid, cygheap->user.sid (), FALSE);
      RtlAppendUnicodeStringToString (&recycler, &sid);
      recycler_user_len = recycler.Length;
    }
  /* Create hopefully unique filename. */
  RtlAppendUnicodeToString (&recycler, L"\\cyg");
  pfii = (PFILE_INTERNAL_INFORMATION) infobuf;
  status = NtQueryInformationFile (h, &io, pfii, sizeof infobuf,
				   FileInternalInformation);
  if (!NT_SUCCESS (status))
    {
      debug_printf ("NtQueryInformationFile (FileInternalInformation) failed, "
		    "%08x", status);
      goto out;
    }
  RtlInt64ToHexUnicodeString (pfii->FileId.QuadPart, &recycler, TRUE);
  /* Shoot. */
  pfri = (PFILE_RENAME_INFORMATION) infobuf;
  pfri->ReplaceIfExists = TRUE;
  pfri->RootDirectory = rootdir;
  pfri->FileNameLength = recycler.Length;
  memcpy (pfri->FileName, recycler.Buffer, recycler.Length);
  status = NtSetInformationFile (h, &io, pfri, sizeof infobuf,
				 FileRenameInformation);
  if (status == STATUS_OBJECT_PATH_NOT_FOUND)
    {
      /* Ok, so the recycler and/or the recycler/SID directory don't exist.
	 First reopen root dir with permission to create subdirs. */
      NtClose (rootdir);
      status = NtOpenFile (&rootdir, FILE_ADD_SUBDIRECTORY, &attr, &io,
			   FILE_SHARE_VALID_FLAGS, FILE_OPEN_FOR_BACKUP_INTENT);
      if (!NT_SUCCESS (status))
	{
	  debug_printf ("NtOpenFile (%S) failed, %08x", &recycler, status);
	  goto out;
	}
      /* Then check if recycler exists by opening and potentially creating it.
	 Yes, we can really do that.  Typically the recycle bin is created
	 by the first user actually using the bin.  The permissions are the
	 default permissions propagated from the root directory. */
      InitializeObjectAttributes (&attr, &recycler, OBJ_CASE_INSENSITIVE,
				  rootdir, NULL);
      recycler.Length = recycler_base_len;
      status = NtCreateFile (&recyclerdir,
			     READ_CONTROL
			     | (win32_path.fs_is_ntfs () ? 0 : FILE_ADD_FILE),
			     &attr, &io, NULL,
			     FILE_ATTRIBUTE_DIRECTORY
			     | FILE_ATTRIBUTE_SYSTEM
			     | FILE_ATTRIBUTE_HIDDEN,
			     FILE_SHARE_VALID_FLAGS, FILE_OPEN_IF,
			     FILE_DIRECTORY_FILE, NULL, 0);
      if (!NT_SUCCESS (status))
	{
	  debug_printf ("NtCreateFile (%S) failed, %08x", &recycler, status);
	  goto out;
	}
      /* Next, if necessary, check if the recycler/SID dir exists and
	 create it if not. */
      if (win32_path.fs_is_ntfs ())
	{
	  NtClose (recyclerdir);
	  recycler.Length = recycler_user_len;
	  status = NtCreateFile (&recyclerdir, READ_CONTROL | FILE_ADD_FILE,
				 &attr, &io, NULL, FILE_ATTRIBUTE_DIRECTORY
						   | FILE_ATTRIBUTE_SYSTEM
						   | FILE_ATTRIBUTE_HIDDEN,
				 FILE_SHARE_VALID_FLAGS, FILE_OPEN_IF,
				 FILE_DIRECTORY_FILE, NULL, 0);
	  if (!NT_SUCCESS (status))
	    {
	      debug_printf ("NtCreateFile (%S) failed, %08x",
			    &recycler, status);
	      goto out;
	    }
	}
      /* The desktop.ini and INFO2 (pre-Vista) files are expected by
	 Windows Explorer.  Otherwise, the created bin is treated as
	 corrupted */
      if (io.Information == FILE_CREATED)
	{
	  HANDLE fh;
	  RtlInitUnicodeString (&fname, L"desktop.ini");
	  InitializeObjectAttributes (&attr, &fname, OBJ_CASE_INSENSITIVE,
				      recyclerdir, NULL);
	  status = NtCreateFile (&fh, FILE_GENERIC_WRITE, &attr, &io, NULL,
				 FILE_ATTRIBUTE_SYSTEM | FILE_ATTRIBUTE_HIDDEN,
				 FILE_SHARE_VALID_FLAGS, FILE_CREATE,
				 FILE_SYNCHRONOUS_IO_NONALERT
				 | FILE_NON_DIRECTORY_FILE, NULL, 0);
	  if (!NT_SUCCESS (status))
	    debug_printf ("NtCreateFile (%S) failed, %08x", &recycler, status);
	  else
	    {
	      status = NtWriteFile (fh, NULL, NULL, NULL, &io, desktop_ini,
				    sizeof desktop_ini - 1, NULL, NULL);
	      if (!NT_SUCCESS (status))
		debug_printf ("NtWriteFile (%S) failed, %08x", &fname, status);
	      NtClose (fh);
	    }
	  if (!wincap.has_recycle_dot_bin ()) /* No INFO2 file since Vista */
	    {
	      RtlInitUnicodeString (&fname, L"INFO2");
	      status = NtCreateFile (&fh, FILE_GENERIC_WRITE, &attr, &io, NULL,
				     FILE_ATTRIBUTE_ARCHIVE
				     | FILE_ATTRIBUTE_HIDDEN,
				     FILE_SHARE_VALID_FLAGS, FILE_CREATE,
				     FILE_SYNCHRONOUS_IO_NONALERT
				     | FILE_NON_DIRECTORY_FILE, NULL, 0);
		if (!NT_SUCCESS (status))
		  debug_printf ("NtCreateFile (%S) failed, %08x",
				&recycler, status);
		else
		{
		  status = NtWriteFile (fh, NULL, NULL, NULL, &io, info2,
					sizeof info2, NULL, NULL);
		  if (!NT_SUCCESS (status))
		    debug_printf ("NtWriteFile (%S) failed, %08x",
				  &fname, status);
		  NtClose (fh);
		}
	    }
	}
      NtClose (recyclerdir);
      /* Shoot again. */
      status = NtSetInformationFile (h, &io, pfri, sizeof infobuf,
				     FileRenameInformation);
    }
  if (!NT_SUCCESS (status))
    debug_printf ("Move %S to %S failed, status = %p",
		  win32_path.get_nt_native_path (), &recycler, status);
out:
  if (rootdir)
    NtClose (rootdir);
}

static NTSTATUS
check_dir_not_empty (HANDLE dir)
{
  IO_STATUS_BLOCK io;
  const ULONG bufsiz = 3 * sizeof (FILE_NAMES_INFORMATION)
		       + 3 * NAME_MAX * sizeof (WCHAR);
  PFILE_NAMES_INFORMATION pfni = (PFILE_NAMES_INFORMATION)
				 alloca (bufsiz);
  NTSTATUS status = NtQueryDirectoryFile (dir, NULL, NULL, 0, &io, pfni,
					  bufsiz, FileNamesInformation,
					  FALSE, NULL, TRUE);
  if (!NT_SUCCESS (status))
    {
      syscall_printf ("Checking if directory is empty failed, "
		      "status = %p", status);
      return status;
    }
  int cnt = 1;
  while (pfni->NextEntryOffset)
    {
      pfni = (PFILE_NAMES_INFORMATION)
	     ((caddr_t) pfni + pfni->NextEntryOffset);
      ++cnt;
    }
  if (cnt > 2)
    {
      syscall_printf ("Directory not empty");
      return STATUS_DIRECTORY_NOT_EMPTY;
    }
  return STATUS_SUCCESS;
}

NTSTATUS
unlink_nt (path_conv &pc)
{
  NTSTATUS status;
  HANDLE fh;
  OBJECT_ATTRIBUTES attr;
  IO_STATUS_BLOCK io;
  FILE_BASIC_INFORMATION fbi;

  ACCESS_MASK access = DELETE;
  /* If the R/O attribute is set, we have to open the file with
     FILE_WRITE_ATTRIBUTES to be able to remove this flags before trying
     to delete it. */
  if (pc.file_attributes () & FILE_ATTRIBUTE_READONLY)
    access |= FILE_WRITE_ATTRIBUTES;

  ULONG flags = FILE_OPEN_FOR_BACKUP_INTENT;
  /* Add the reparse point flag to native symlinks, otherwise we remove the
     target, not the symlink. */
  if (pc.is_rep_symlink ())
    flags |= FILE_OPEN_REPARSE_POINT;

  pc.get_object_attr (attr, sec_none_nih);
  /* First try to open the file with sharing not allowed.  If the file
     has an open handle on it, this will fail.  That indicates that the
     file has to be moved to the recycle bin so that it actually disappears
     from its directory even though its in use.  Otherwise, if opening
     doesn't fail, the file is not in use and by simply closing the handle
     the file will disappear. */
  bool move_to_bin = false;
  status = NtOpenFile (&fh, access, &attr, &io, 0, flags);
  if (status == STATUS_SHARING_VIOLATION)
    {
      move_to_bin = true;
      if (!pc.isdir () || pc.isremote ())
	status = NtOpenFile (&fh, access, &attr, &io,
			     FILE_SHARE_VALID_FLAGS, flags);
      else
	{
	  /* It's getting tricky.  The directory is opened in some process,
	     so we're supposed to move it to the recycler and mark it for
	     deletion.  But what if the directory is not empty?  The move
	     will work, but the subsequent delete will fail.  So we would
	     have to move it back.  That's bad, because the directory would
	     be moved around which results in a temporary inconsistent state.
	     So, what we do here is to test if the directory is empty.  If
	     not, we bail out with ERROR_DIR_NOT_EMTPY.  The below code
	     tests for at least three entries in the directory, ".", "..",
	     and another one.  Three entries means, not empty.  This doesn't
	     work for the root directory of a drive, but the root dir can
	     neither be deleted, nor moved anyway. */
	  status = NtOpenFile (&fh, access | FILE_LIST_DIRECTORY | SYNCHRONIZE,
			       &attr, &io, FILE_SHARE_VALID_FLAGS,
			       flags | FILE_SYNCHRONOUS_IO_NONALERT);
	  if (NT_SUCCESS (status))
	    {
	      status = check_dir_not_empty (fh);
	      if (!NT_SUCCESS (status))
		{
		  NtClose (fh);
		  return status;
		}
	    }
	}
    }
  if (!NT_SUCCESS (status))
    {
      if (status == STATUS_DELETE_PENDING)
	{
	  syscall_printf ("Delete already pending");
	  return 0;
	}
      syscall_printf ("Opening file for delete failed, status = %p", status);
      return status;
    }

  if (move_to_bin && !pc.isremote ())
    try_to_bin (pc, fh);

  /* Get rid of read-only attribute. */
  if (access & FILE_WRITE_ATTRIBUTES)
    {
      fbi.CreationTime.QuadPart = fbi.LastAccessTime.QuadPart =
      fbi.LastWriteTime.QuadPart = fbi.ChangeTime.QuadPart = 0LL;
      fbi.FileAttributes = (pc.file_attributes () & ~FILE_ATTRIBUTE_READONLY)
			   ?: FILE_ATTRIBUTE_NORMAL;
      NtSetInformationFile (fh, &io,  &fbi, sizeof fbi, FileBasicInformation);
    }

  FILE_DISPOSITION_INFORMATION disp = { TRUE };
  status = NtSetInformationFile (fh, &io, &disp, sizeof disp,
				 FileDispositionInformation);
  if (!NT_SUCCESS (status))
    {
      syscall_printf ("Setting delete disposition failed, status = %p", status);
      if (access & FILE_WRITE_ATTRIBUTES)
	{
	  /* Restore R/O attributes. */
	  fbi.FileAttributes = pc.file_attributes ();
	  NtSetInformationFile (fh, &io,  &fbi, sizeof fbi,
				FileBasicInformation);
	}
    }
  else if ((access & FILE_WRITE_ATTRIBUTES) && !pc.isdir ())
    {
      /* Restore R/O attribute to accommodate hardlinks.  Don't try this
	 with directories!  For some reason the below NtSetInformationFile
	 changes the disposition for delete back to FALSE, at least on XP. */
      fbi.FileAttributes = pc.file_attributes ();
      NtSetInformationFile (fh, &io,  &fbi, sizeof fbi,
			    FileBasicInformation);
    }

  NtClose (fh);
  return status;
}

extern "C" int
unlink (const char *ourname)
{
  int res = -1;
  DWORD devn;
  NTSTATUS status;

  path_conv win32_name (ourname, PC_SYM_NOFOLLOW,
			transparent_exe ? stat_suffixes : NULL);

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

  devn = win32_name.get_devn ();
  if (isproc_dev (devn))
    {
      set_errno (EROFS);
      goto done;
    }

  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;
    }

  status = unlink_nt (win32_name);
  if (NT_SUCCESS (status))
    res = 0;
  else
    __seterrno_from_nt_status (status);

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

extern "C" int
_remove_r (struct _reent *, const char *ourname)
{
  path_conv win32_name (ourname, PC_SYM_NOFOLLOW);

  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" int
remove (const char *ourname)
{
  path_conv win32_name (ourname, PC_SYM_NOFOLLOW);

  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)
{
#ifdef NEWVFORK
  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 */
    }
#endif

  if (myself->pgid == myself->pid)
    syscall_printf ("hmm.  pgid %d pid %d", myself->pgid, myself->pid);
  else
    {
      myself->ctty = -1;
      cygheap->manage_console_count ("setsid", 0);
      myself->sid = getpid ();
      myself->pgid = getpid ();
      if (cygheap->ctty)
	cygheap->close_ctty ();
      syscall_printf ("sid %d, pgid %d, %s", myself->sid, myself->pgid, myctty ());
      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
pread (int fd, void *ptr, size_t len, _off64_t off)
{
  ssize_t res;
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    res = -1;
  else
    res = cfd->pread (ptr, len, off);

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

extern "C" ssize_t
pwrite (int fd, void *ptr, size_t len, _off64_t off)
{
  ssize_t res;
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    res = -1;
  else
    res = cfd->pwrite (ptr, len, off);

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

EXPORT_ALIAS (read, _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);
}

EXPORT_ALIAS (write, _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)
    {
      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->uninterruptible_io ()))
	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 || !_my_tls.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;
  const ssize_t tot = check_iovec_for_write (iov, iovcnt);

  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 > (int) 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 ();

  syscall_printf ("open (%s, %p)", unix_path, flags);
  myfault efault;
  if (efault.faulted (EFAULT))
    /* errno already set */;
  else if (!*unix_path)
    set_errno (ENOENT);
  else
    {
      /* 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)
	{
	  if (!(fh = build_fh_name (unix_path, NULL,
				    (flags & (O_NOFOLLOW | O_EXCL))
				    ?  PC_SYM_NOFOLLOW : PC_SYM_FOLLOW,
				    transparent_exe ? stat_suffixes : NULL)))
	    res = -1;		// errno already set
	  else if ((flags & O_NOFOLLOW) && fh->issymlink ())
	    {
	      delete fh;
	      res = -1;
	      set_errno (ELOOP);
	    }
	  else if (((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) && fh->exists ())
	    {
	      delete fh;
	      res = -1;
	      set_errno (EEXIST);
	    }
	  else if (fh->is_fs_special () && fh->device_access_denied (flags))
	    {
	      delete fh;
	      res = -1;
	    }
	  else if (!fh->open (flags, (mode & 07777) & ~cygheap->umask))
	    {
	      delete fh;
	      res = -1;
	    }
	  else
	    {
	      cygheap->fdtab[fd] = fh;
	      if ((res = fd) <= 2)
		set_std_handle (res);
	    }
	}
    }

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

EXPORT_ALIAS (open, _open )
EXPORT_ALIAS (open, _open64 )

extern "C" _off64_t
lseek64 (int fd, _off64_t pos, int dir)
{
  _off64_t res;

  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;
}

EXPORT_ALIAS (lseek64, _lseek64)

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

EXPORT_ALIAS (lseek, _lseek)

extern "C" int
close (int fd)
{
  int res;

  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;
}

EXPORT_ALIAS (close, _close)

extern "C" int
isatty (int fd)
{
  int res;

  cygheap_fdget cfd (fd);
  if (cfd < 0)
    res = 0;
  else
    res = cfd->is_tty ();
  syscall_printf ("%d = isatty (%d)", res, fd);
  return res;
}
EXPORT_ALIAS (isatty, _isatty)

/* 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 *oldpath, const char *newpath)
{
  int res = -1;
  fhandler_base *fh;

  if (!(fh = build_fh_name (oldpath, NULL, PC_SYM_NOFOLLOW,
			    transparent_exe ? stat_suffixes : NULL)))
    goto error;

  if (fh->error ())
    {
      debug_printf ("got %d error from build_fh_name", fh->error ());
      set_errno (fh->error ());
    }
  else
    res = fh->link (newpath);

  delete fh;
 error:
  syscall_printf ("%d = link (%s, %s)", res, oldpath, newpath);
  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 = -1;
  fhandler_base *fh;

  if (!(fh = build_fh_name (name, NULL, fmode, stat_suffixes)))
    goto error;

  if (fh->error ())
    {
      debug_printf ("got %d error from build_fh_name", fh->error ());
      set_errno (fh->error ());
    }
  else
    res = fh->fchown (uid, gid);

  delete fh;
 error:
  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)
{
  return chown_worker (name, PC_SYM_FOLLOW, uid, gid);
}

extern "C" int
chown (const char * name, __uid16_t uid, __gid16_t gid)
{
  return chown_worker (name, PC_SYM_FOLLOW,
		       uid16touid32 (uid), gid16togid32 (gid));
}

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

extern "C" int
lchown (const char * name, __uid16_t uid, __gid16_t gid)
{
  return chown_worker (name, PC_SYM_NOFOLLOW,
		       uid16touid32 (uid), gid16togid32 (gid));
}

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

  int res = cfd->fchown (uid, gid);

  syscall_printf ("%d = fchown (%s,...)", res, cfd->get_name ());
  return res;
}

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;
}

int
chmod_device (path_conv& pc, mode_t mode)
{
  return mknod_worker (pc.get_win32 (), pc.dev.mode & S_IFMT, mode, pc.dev.major, pc.dev.minor);
}

/* chmod: POSIX 5.6.4.1 */
extern "C" int
chmod (const char *path, mode_t mode)
{
  int res = -1;
  fhandler_base *fh;
  if (!(fh = build_fh_name (path, NULL, PC_SYM_FOLLOW, stat_suffixes)))
    goto error;

  if (fh->error ())
    {
      debug_printf ("got %d error from build_fh_name", fh->error ());
      set_errno (fh->error ());
    }
  else
    res = fh->fchmod (mode);

  delete fh;
 error:
  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)
{
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    {
      syscall_printf ("-1 = fchmod (%d, 0%o)", fd, mode);
      return -1;
    }

  return cfd->fchmod (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;

  cygheap_fdget cfd (fd);
  if (cfd < 0)
    res = -1;
  else
    {
      memset (buf, 0, sizeof (struct __stat64));
      res = cfd->fstat (buf);
      if (!res)
	{
	  if (!buf->st_ino)
	    buf->st_ino = cfd->get_ino ();
	  if (!buf->st_dev)
	    buf->st_dev = cfd->get_device ();
	  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;

  if ((ret = fstat64 (fd, buf)) == -1)
    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;

  if ((ret = fstat (fd, buf)) == -1)
    ptr->_errno = get_errno ();
  return ret;
}

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

EXPORT_ALIAS (fsync, fdatasync)

static void
sync_worker (const char *vol)
{
  HANDLE fh = CreateFileA (vol, GENERIC_WRITE, FILE_SHARE_VALID_FLAGS,
			   &sec_none_nih, OPEN_EXISTING, 0, NULL);
  if (fh != INVALID_HANDLE_VALUE)
    {
      FlushFileBuffers (fh);
      CloseHandle (fh);
    }
  else
    debug_printf ("Open failed with %E");
}

/* sync: SUSv3 */
extern "C" void
sync ()
{
  /* Per MSDN, 50 bytes should be enough here. */
  char vol[MAX_PATH];

  if (wincap.has_guid_volumes ()) /* Win2k and newer */
    {
      char a_drive[MAX_PATH] = {0};
      char b_drive[MAX_PATH] = {0};

      if (is_floppy ("A:"))
	GetVolumeNameForVolumeMountPointA ("A:\\", a_drive, MAX_PATH);
      if (is_floppy ("B:"))
	GetVolumeNameForVolumeMountPointA ("B:\\", b_drive, MAX_PATH);

      HANDLE sh = FindFirstVolumeA (vol, MAX_PATH);
      if (sh != INVALID_HANDLE_VALUE)
	{
	  do
	    {
	      debug_printf ("Try volume %s", vol);

	      /* Check vol for being a floppy on A: or B:.  Skip them. */
	      if (strcasematch (vol, a_drive) || strcasematch (vol, b_drive))
		{
		  debug_printf ("Is floppy, don't sync");
		  continue;
		}

	      /* Eliminate trailing backslash. */
	      vol[strlen (vol) - 1] = '\0';
	      sync_worker (vol);
	    }
	  while (FindNextVolumeA (sh, vol, MAX_PATH));
	  FindVolumeClose (sh);
	}
    }
  else
    {
      DWORD drives = GetLogicalDrives ();
      DWORD mask = 1;
      /* Skip floppies on A: and B: as in setmntent. */
      if ((drives & 1) && is_floppy ("A:"))
	drives &= ~1;
      if ((drives & 2) && is_floppy ("B:"))
	drives &= ~2;
      strcpy (vol, "\\\\.\\A:");
      do
	{
	  /* Geeh.  Try to sync only non-floppy drives. */
	  if (drives & mask)
	    {
	      debug_printf ("Try volume %s", vol);
	      sync_worker (vol);
	    }
	  vol[4]++;
	}
      while ((mask <<= 1) <= 1 << 25);
    }
}

/* Cygwin internal */
int __stdcall
stat_worker (path_conv &pc, struct __stat64 *buf)
{
  int res = -1;

  myfault efault;
  if (efault.faulted (EFAULT))
    goto error;

  if (pc.error)
    {
      debug_printf ("got %d error from build_fh_name", pc.error);
      set_errno (pc.error);
    }
  else if (pc.exists ())
    {
      fhandler_base *fh;

      if (!(fh = build_fh_pc (pc)))
	goto error;

      debug_printf ("(%S, %p, %p), file_attributes %d",
		    pc.get_nt_native_path (), buf, fh, (DWORD) *fh);
      memset (buf, 0, sizeof (*buf));
      res = fh->fstat (buf);
      if (!res)
	{
	  if (!buf->st_ino)
	    buf->st_ino = fh->get_ino ();
	  if (!buf->st_dev)
	    buf->st_dev = fh->get_device ();
	  if (!buf->st_rdev)
	    buf->st_rdev = buf->st_dev;
	}
      delete fh;
    }
  else
    set_errno (ENOENT);

 error:
  MALLOC_CHECK;
  syscall_printf ("%d = (%S, %p)", res, pc.get_nt_native_path (), buf);
  return res;
}

extern "C" int
stat64 (const char *name, struct __stat64 *buf)
{
  syscall_printf ("entering");
  path_conv pc (name, PC_SYM_FOLLOW | PC_POSIX, stat_suffixes);
  return stat_worker (pc, buf);
}

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

  if ((ret = stat64 (name, buf)) == -1)
    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;

  if ((ret = stat (name, buf)) == -1)
    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)
{
  syscall_printf ("entering");
  path_conv pc (name, PC_SYM_NOFOLLOW | PC_POSIX, stat_suffixes);
  return stat_worker (pc, buf);
}

/* 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)
{
  // flags were incorrectly specified
  int res = -1;
  if (flags & ~(F_OK|R_OK|W_OK|X_OK))
    set_errno (EINVAL);
  else
    {
      fhandler_base *fh = build_fh_name (fn, NULL, PC_SYM_FOLLOW, stat_suffixes);
      if (fh)
	{
	  res =  fh->fhaccess (flags);
	  delete fh;
	}
    }
  debug_printf ("returning %d", res);
  return res;
}

static void
rename_append_suffix (path_conv &pc, const char *path, size_t len,
		      const char *suffix)
{
  char buf[len + 5];

  if (ascii_strcasematch (path + len - 4, ".lnk")
      || ascii_strcasematch (path + len - 4, ".exe"))
    len -= 4;
  stpcpy (stpncpy (buf, path, len), suffix);
  pc.check (buf, PC_SYM_NOFOLLOW);
}

extern "C" int
rename (const char *oldpath, const char *newpath)
{
  int res = -1;
  char *oldbuf, *newbuf;
  path_conv oldpc, newpc, new2pc, *dstpc, *removepc = NULL;
  bool old_dir_requested = false, new_dir_requested = false;
  bool old_explicit_suffix = false, new_explicit_suffix = false;
  size_t olen, nlen;
  bool equal_path;
  NTSTATUS status;
  HANDLE fh = NULL, nfh;
  OBJECT_ATTRIBUTES attr;
  IO_STATUS_BLOCK io;
  ULONG size;
  FILE_STANDARD_INFORMATION ofsi;
  PFILE_RENAME_INFORMATION pfri;

  myfault efault;
  if (efault.faulted (EFAULT))
    return -1;

  if (has_dot_last_component (oldpath, true))
    {
      oldpc.check (oldpath, PC_SYM_NOFOLLOW, stat_suffixes);
      set_errno (oldpc.isdir () ? EBUSY : ENOTDIR);
      goto out;
    }
  if (has_dot_last_component (newpath, true))
    {
      newpc.check (newpath, PC_SYM_NOFOLLOW, stat_suffixes);
      set_errno (!newpc.exists () ? ENOENT : newpc.isdir () ? EBUSY : ENOTDIR);
      goto out;
    }

  /* A trailing slash requires that the pathname points to an existing
     directory.  If it's not, it's a ENOTDIR condition.  The same goes
     for newpath a bit further down this function. */
  olen = strlen (oldpath);
  if (isdirsep (oldpath[olen - 1]))
    {
      stpcpy (oldbuf = (char *) alloca (olen + 1), oldpath);
      while (olen > 0 && isdirsep (oldbuf[olen - 1]))
	oldbuf[--olen] = '\0';
      oldpath = oldbuf;
      old_dir_requested = true;
    }
  oldpc.check (oldpath, PC_SYM_NOFOLLOW, stat_suffixes);
  if (oldpc.error)
    {
      set_errno (oldpc.error);
      goto out;
    }
  if (!oldpc.exists ())
    {
      set_errno (ENOENT);
      goto out;
    }
  if (oldpc.isspecial ()) /* No renames from virtual FS */
    {
      set_errno (EROFS);
      goto out;
    }
  if (old_dir_requested && !oldpc.isdir ())
    {
      set_errno (ENOTDIR);
      goto out;
    }
  if (oldpc.known_suffix
      && (ascii_strcasematch (oldpath + olen - 4, ".lnk")
	  || ascii_strcasematch (oldpath + olen - 4, ".exe")))
    old_explicit_suffix = true;

  nlen = strlen (newpath);
  if (isdirsep (newpath[nlen - 1]))
    {
      stpcpy (newbuf = (char *) alloca (nlen + 1), newpath);
      while (nlen > 0 && isdirsep (newbuf[nlen - 1]))
	newbuf[--nlen] = '\0';
      newpath = newbuf;
      new_dir_requested = true;
    }
  newpc.check (newpath, PC_SYM_NOFOLLOW, stat_suffixes);
  if (newpc.error)
    {
      set_errno (newpc.error);
      goto out;
    }
  if (newpc.isspecial ()) /* No renames to virtual FSes */
    {
      set_errno (EROFS);
      goto out;
    }
  if (new_dir_requested && !newpc.isdir ())
    {
      set_errno (ENOTDIR);
      goto out;
    }
  if (newpc.known_suffix
      && (ascii_strcasematch (newpath + nlen - 4, ".lnk")
	  || ascii_strcasematch (newpath + nlen - 4, ".exe")))
    new_explicit_suffix = true;

  /* This test is necessary in almost every case, so just do it once here. */
  equal_path = RtlEqualUnicodeString (oldpc.get_nt_native_path (),
				      newpc.get_nt_native_path (),
				      TRUE);

  /* First check if oldpath and newpath only differ by case.  If so, it's
     just a request to change the case of the filename.  By simply setting
     the file attributes to INVALID_FILE_ATTRIBUTES (which translates to
     "file doesn't exist"), all later tests are skipped. */
  if (newpc.exists () && equal_path)
    {
      if (RtlEqualUnicodeString (oldpc.get_nt_native_path (),
				 newpc.get_nt_native_path (),
				 FALSE))
	{
	  res = 0;
	  goto out;
	}
      newpc.file_attributes (INVALID_FILE_ATTRIBUTES);
    }
  else if (oldpc.isdir ())
    {
      if (newpc.exists () && !newpc.isdir ())
	{
	  set_errno (ENOTDIR);
	  goto out;
	}
      /* Check for newpath being a subdir of oldpath. */
      if (RtlPrefixUnicodeString (oldpc.get_nt_native_path (),
				  newpc.get_nt_native_path (),
				  TRUE)
	  && newpc.get_nt_native_path ()->Length >
	     oldpc.get_nt_native_path ()->Length
	  && *(PWCHAR) ((PBYTE) newpc.get_nt_native_path ()->Buffer
			+ oldpc.get_nt_native_path ()->Length) == L'\\')
	{
	  set_errno (EINVAL);
	  goto out;
	}
    }
  else if (!newpc.exists ())
    {
      if (equal_path && old_explicit_suffix != new_explicit_suffix)
	{
	  newpc.check (newpath, PC_SYM_NOFOLLOW);
	  if (RtlEqualUnicodeString (oldpc.get_nt_native_path (),
				     newpc.get_nt_native_path (),
				     TRUE))
	    {
	      res = 0;
	      goto out;
	    }
	}
      else if (oldpc.is_lnk_symlink ()
	       && !RtlEqualUnicodePathSuffix (newpc.get_nt_native_path (),
					      L".lnk", TRUE))
	rename_append_suffix (newpc, newpath, nlen, ".lnk");
      else if (oldpc.is_binary ()
	   && !RtlEqualUnicodePathSuffix (newpc.get_nt_native_path (),
					  L".exe", TRUE))
	/* NOTE: No way to rename an executable foo.exe to foo. */
	rename_append_suffix (newpc, newpath, nlen, ".exe");
    }
  else if (newpc.isdir ())
    {
      set_errno (EISDIR);
      goto out;
    }
  else
    {
      if (equal_path && old_explicit_suffix != new_explicit_suffix)
	{
	  newpc.check (newpath, PC_SYM_NOFOLLOW);
	  if (RtlEqualUnicodeString (oldpc.get_nt_native_path (),
				     newpc.get_nt_native_path (),
				     TRUE))
	    {
	      res = 0;
	      goto out;
	    }
	}
      else if (oldpc.is_lnk_symlink ())
	{
	  if (!newpc.is_lnk_symlink ()
	      && !RtlEqualUnicodePathSuffix (newpc.get_nt_native_path (),
					     L".lnk", TRUE))
	    {
	      rename_append_suffix (new2pc, newpath, nlen, ".lnk");
	      removepc = &newpc;
	    }
	}
      else if (oldpc.is_binary ())
	{
	  if (!RtlEqualUnicodePathSuffix (newpc.get_nt_native_path (),
					  L".exe", TRUE))
	    {
	      rename_append_suffix (new2pc, newpath, nlen, ".exe");
	      removepc = &newpc;
	    }
	}
      else
	{
	  if ((RtlEqualUnicodePathSuffix (newpc.get_nt_native_path (),
					  L".lnk", TRUE)
	       || RtlEqualUnicodePathSuffix (newpc.get_nt_native_path (),
					     L".exe", TRUE))
	      && !new_explicit_suffix)
	    {
	      new2pc.check (newpath, PC_SYM_NOFOLLOW, stat_suffixes);
	      newpc.get_nt_native_path ()->Length -= 4 * sizeof (WCHAR);
	      if (new2pc.is_binary () || new2pc.is_lnk_symlink ())
		removepc = &new2pc;
	    }
	}
    }
  dstpc = (removepc == &newpc) ? &new2pc : &newpc;

  /* DELETE is required to rename a file. */
  status = NtOpenFile (&fh, DELETE, oldpc.get_object_attr (attr, sec_none_nih),
		     &io, FILE_SHARE_VALID_FLAGS,
		     FILE_OPEN_FOR_BACKUP_INTENT
		     | (oldpc.is_rep_symlink () ? FILE_OPEN_REPARSE_POINT : 0));
  if (!NT_SUCCESS (status))
    {
      __seterrno_from_nt_status (status);
      goto out;
    }

  /* Renaming a dir to another, existing dir fails always, even if
     ReplaceIfExists is set to TRUE and the existing dir is empty.  So
     we have to remove the destination dir first.  This also covers the
     case that the destination directory is not empty.  In that case,
     unlink_nt returns with STATUS_DIRECTORY_NOT_EMPTY. */
  if (dstpc->isdir ())
    {
      status = unlink_nt (*dstpc);
      if (!NT_SUCCESS (status))
	{
	  __seterrno_from_nt_status (status);
	  goto out;
	}
    }
  /* You can't copy a file if the destination exists and has the R/O
     attribute set.  Remove the R/O attribute first. */
  else if (dstpc->has_attribute (FILE_ATTRIBUTE_READONLY))
    {
      status = NtOpenFile (&nfh, FILE_WRITE_ATTRIBUTES,
			   dstpc->get_object_attr (attr, sec_none_nih),
			   &io, FILE_SHARE_VALID_FLAGS,
			   FILE_OPEN_FOR_BACKUP_INTENT
			   | (dstpc->is_rep_symlink ()
			      ? FILE_OPEN_REPARSE_POINT : 0));
      if (!NT_SUCCESS (status))
	{
	  __seterrno_from_nt_status (status);
	  goto out;
	}
      FILE_BASIC_INFORMATION fbi;
      fbi.CreationTime.QuadPart = fbi.LastAccessTime.QuadPart =
      fbi.LastWriteTime.QuadPart = fbi.ChangeTime.QuadPart = 0LL;
      fbi.FileAttributes = (dstpc->file_attributes ()
			    & ~FILE_ATTRIBUTE_READONLY)
			   ?: FILE_ATTRIBUTE_NORMAL;
      status = NtSetInformationFile (nfh, &io,  &fbi, sizeof fbi,
				     FileBasicInformation);
      NtClose (nfh);
      if (!NT_SUCCESS (status))
	{
	  __seterrno_from_nt_status (status);
	  goto out;
	}
    }

  /* SUSv3: If the old argument and the new argument resolve to the same
     existing file, rename() shall return successfully and perform no
     other action.
     The test tries to be as quick as possible.  First it tests if oldpath
     has more than 1 hardlink, then it opens newpath and tests for identical
     file ids.  If so, it tests for identical volume serial numbers,  If so,
     oldpath and newpath refer to the same file. */
  if ((removepc || dstpc->exists ())
      && !oldpc.isdir ()
      && NT_SUCCESS (NtQueryInformationFile (fh, &io, &ofsi, sizeof ofsi,
					     FileStandardInformation))
      && ofsi.NumberOfLinks > 1
      && NT_SUCCESS (NtOpenFile (&nfh, READ_CONTROL,
		     (removepc ?: dstpc)->get_object_attr (attr, sec_none_nih),
		     &io, FILE_SHARE_VALID_FLAGS,
		     FILE_OPEN_FOR_BACKUP_INTENT
		     | ((removepc ?: dstpc)->is_rep_symlink ()
			? FILE_OPEN_REPARSE_POINT : 0))))
    {
      static const size_t vsiz = sizeof (FILE_FS_VOLUME_INFORMATION)
				 + 32 * sizeof (WCHAR);
      FILE_INTERNAL_INFORMATION ofii, nfii;
      PFILE_FS_VOLUME_INFORMATION opffvi, npffvi;

      if (NT_SUCCESS (NtQueryInformationFile (fh, &io, &ofii, sizeof ofii,
					      FileInternalInformation))
	  && NT_SUCCESS (NtQueryInformationFile (nfh, &io, &nfii, sizeof nfii,
						 FileInternalInformation))
	  && ofii.FileId.QuadPart == nfii.FileId.QuadPart
	  && (opffvi = (PFILE_FS_VOLUME_INFORMATION) alloca (vsiz))
	  && (npffvi = (PFILE_FS_VOLUME_INFORMATION) alloca (vsiz))
	  && NT_SUCCESS (NtQueryVolumeInformationFile (fh, &io, opffvi, vsiz,
						    FileFsVolumeInformation))
	  && NT_SUCCESS (NtQueryVolumeInformationFile (nfh, &io, npffvi, vsiz,
						    FileFsVolumeInformation))
	  && opffvi->VolumeSerialNumber == npffvi->VolumeSerialNumber)
	{
	  debug_printf ("%s and %s are the same file", oldpath, newpath);
	  NtClose (nfh);
	  res = 0;
	  goto out;
	}
      NtClose (nfh);
    }
  size = sizeof (FILE_RENAME_INFORMATION)
	 + dstpc->get_nt_native_path ()->Length;
  pfri = (PFILE_RENAME_INFORMATION) alloca (size);
  pfri->ReplaceIfExists = TRUE;
  pfri->RootDirectory = NULL;
  pfri->FileNameLength = dstpc->get_nt_native_path ()->Length;
  memcpy (&pfri->FileName,  dstpc->get_nt_native_path ()->Buffer,
	  pfri->FileNameLength);
  status = NtSetInformationFile (fh, &io, pfri, size, FileRenameInformation);
  /* This happens if the access rights don't allow deleting the destination.
     Even if the handle to the original file is opened with BACKUP
     and/or RECOVERY, these flags don't apply to the destination of the
     rename operation.  So, a privileged user can't rename a file to an
     existing file, if the permissions of the existing file aren't right.
     Like directories, we have to handle this separately by removing the
     destination before renaming. */
  if (status == STATUS_ACCESS_DENIED && dstpc->exists () && !dstpc->isdir ()
      && NT_SUCCESS (status = unlink_nt (*dstpc)))
    status = NtSetInformationFile (fh, &io, pfri, size, FileRenameInformation);
  if (NT_SUCCESS (status))
    {
      if (removepc)
	unlink_nt (*removepc);
      res = 0;
    }
  else
    __seterrno_from_nt_status (status);

out:
  if (fh)
    NtClose (fh);
  syscall_printf ("%d = rename (%s, %s)", res, oldpath, newpath);
  return res;
}

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

  myfault efault;
  if (efault.faulted (EFAULT))
    return -1;

  int res;
  const char* command[4];

  if (cmdstring == NULL)
    return 1;

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

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

  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.dwAllocationGranularity)
    GetSystemInfo (&system_info);
  return (size_t) system_info.dwAllocationGranularity;
}

size_t
getsystempagesize ()
{
  if (!system_info.dwPageSize)
    GetSystemInfo (&system_info);
  return (size_t) system_info.dwPageSize;
}

/* FIXME: not all values are correct... */
extern "C" long int
fpathconf (int fd, int v)
{
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return -1;
  return cfd->fpathconf (v);
}

extern "C" long int
pathconf (const char *file, int v)
{
  fhandler_base *fh;

  myfault efault;
  if (efault.faulted (EFAULT))
    return -1;
  if (!*file)
    {
      set_errno (ENOENT);
      return -1;
    }
  if (!(fh = build_fh_name (file, NULL, PC_SYM_FOLLOW,
			    transparent_exe ? stat_suffixes : NULL)))
    return -1;
  if (!fh->exists ())
    {
      set_errno (ENOENT);
      return -1;
    }
  return fh->fpathconf (v);
}

extern "C" int
ttyname_r (int fd, char *buf, size_t buflen)
{
  int ret = 0;
  myfault efault;
  if (efault.faulted ())
    ret = EFAULT;
  else
    {
      cygheap_fdget cfd (fd, true);
      if (cfd < 0)
	ret = EBADF;
      else if (!cfd->is_tty ())
	ret = ENOTTY;
      else if (buflen < strlen (cfd->ttyname ()) + 1)
	ret = ERANGE;
      else
	strcpy (buf, cfd->ttyname ());
    }
  debug_printf ("returning %d tty: %s", ret, ret ? "NULL" : buf);
  return ret;
}

extern "C" char *
ttyname (int fd)
{
  static char name[TTY_NAME_MAX];
  int ret = ttyname_r (fd, name, TTY_NAME_MAX);
  if (ret)
    {
      set_errno (ret);
      return NULL;
    }
  return name;
}

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)
{
  if (CYGWIN_VERSION_OLD_STDIO_CRLF_HANDLING)
    {
      syscall_printf ("fd %d: old API", fd);
      return 0; /* we do it for old apps, due to getc/putc macros */
    }

  cygheap_fdget cfd (fd, false, false);
  if (cfd < 0)
    {
      syscall_printf ("fd %d: not open", fd);
      return 0;
    }

#if 0
  if (cfd->get_device () != FH_FS)
    {
      syscall_printf ("fd not disk file.  Defaulting to binary.");
      return 0;
    }
#endif

  if (cfd->wbinary () || cfd->rbinary ())
    {
      syscall_printf ("fd %d: opened as binary", fd);
      return 0;
    }

  syscall_printf ("fd %d: defaulting to text", fd);
  return 1;
}

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

static int
setmode_helper (FILE *f)
{
  if (fileno (f) != _my_tls.locals.setmode_file)
    {
      syscall_printf ("improbable, but %d != %d", fileno (f), _my_tls.locals.setmode_file);
      return 0;
    }
  syscall_printf ("file was %s now %s", f->_flags & __SCLE ? "text" : "binary",
		  _my_tls.locals.setmode_mode & O_TEXT ? "text" : "binary");
  if (_my_tls.locals.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->wbinary () && cfd->rbinary ())
    res = O_BINARY;
  else if (cfd->wbinset () && cfd->rbinset ())
    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);

  syscall_printf ("(%d<%S>, %p) returning %s", fd,
		  cfd->pc.get_nt_native_path (), mode,
		  res & O_TEXT ? "text" : "binary");
  return res;
}

extern "C" int
cygwin_setmode (int fd, int mode)
{
  int res = setmode (fd, mode);
  if (res != -1)
    {
      _my_tls.locals.setmode_file = fd;
      if (_cygwin_istext_for_stdio (fd))
	_my_tls.locals.setmode_mode = O_TEXT;
      else
	_my_tls.locals.setmode_mode = O_BINARY;
      _fwalk (_GLOBAL_REENT, setmode_helper);
    }
  return res;
}

extern "C" int
posix_fadvise (int fd, _off64_t offset, _off64_t len, int advice)
{
  int res = -1;
  cygheap_fdget cfd (fd);
  if (cfd >= 0)
    res = cfd->fadvise (offset, len, advice);
  else
    set_errno (EBADF);
  syscall_printf ("%d = posix_fadvice (%d, %D, %D, %d)",
		  res, fd, offset, len, advice);
  return res;
}

extern "C" int
posix_fallocate (int fd, _off64_t offset, _off64_t len)
{
  int res = -1;
  if (offset < 0 || len == 0)
    set_errno (EINVAL);
  else
    {
      cygheap_fdget cfd (fd);
      if (cfd >= 0)
	res = cfd->ftruncate (offset + len, false);
      else
	set_errno (EBADF);
    }
  syscall_printf ("%d = posix_fallocate (%d, %D, %D)", res, fd, offset, len);
  return res;
}

extern "C" int
ftruncate64 (int fd, _off64_t length)
{
  int res = -1;
  cygheap_fdget cfd (fd);
  if (cfd >= 0)
    res = cfd->ftruncate (length, true);
  else
    set_errno (EBADF);
  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)
{
  int fd;
  int res = -1;

  fd = open (pathname, O_RDWR);

  if (fd != -1)
    {
      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
fstatvfs (int fd, struct statvfs *sfs)
{
  myfault efault;
  if (efault.faulted (EFAULT))
    return -1;

  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return -1;
  return cfd->fstatvfs (sfs);
}

extern "C" int
statvfs (const char *name, struct statvfs *sfs)
{
  int res = -1;
  fhandler_base *fh = NULL;

  myfault efault;
  if (efault.faulted (EFAULT))
    goto error;

  if (!(fh = build_fh_name (name, NULL, PC_SYM_FOLLOW, stat_suffixes)))
    goto error;

  if (fh->error ())
    {
      debug_printf ("got %d error from build_fh_name", fh->error ());
      set_errno (fh->error ());
    }
  else if (fh->exists ())
    {
      debug_printf ("(%s, %p), file_attributes %d", name, sfs, (DWORD) *fh);
      res = fh->fstatvfs (sfs);
    }
  else
    set_errno (ENOENT);

  delete fh;
 error:
  MALLOC_CHECK;
  syscall_printf ("%d = (%s, %p)", res, name, sfs);
  return res;
}

extern "C" int
fstatfs (int fd, struct statfs *sfs)
{
  struct statvfs vfs;
  int ret = fstatvfs (fd, &vfs);
  if (!ret)
    {
      sfs->f_type = vfs.f_flag;
      sfs->f_bsize = vfs.f_bsize;
      sfs->f_blocks = vfs.f_blocks;
      sfs->f_bavail = vfs.f_bavail;
      sfs->f_bfree = vfs.f_bfree;
      sfs->f_files = -1;
      sfs->f_ffree = -1;
      sfs->f_fsid = vfs.f_fsid;
      sfs->f_namelen = vfs.f_namemax;
    }
  return ret;
}

extern "C" int
statfs (const char *fname, struct statfs *sfs)
{
  struct statvfs vfs;
  int ret = statvfs (fname, &vfs);
  if (!ret)
    {
      sfs->f_type = vfs.f_flag;
      sfs->f_bsize = vfs.f_bsize;
      sfs->f_blocks = vfs.f_blocks;
      sfs->f_bavail = vfs.f_bavail;
      sfs->f_bfree = vfs.f_bfree;
      sfs->f_files = -1;
      sfs->f_ffree = -1;
      sfs->f_fsid = vfs.f_fsid;
      sfs->f_namelen = vfs.f_namemax;
    }
  return ret;
}

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

  if (pgid < 0)
    set_errno (EINVAL);
  else
    {
      pinfo p (pid, PID_MAP_RW);
      if (!p)
	set_errno (ESRCH);
      else if (p->pgid == pgid)
	res = 0;
      /* A process may only change the process group of itself and its children */
      else if (p != myself && p->ppid != myself->pid)
	set_errno (EPERM);
      else
	{
	  p->pgid = pgid;
	  if (p->pid != p->pgid)
	    p->set_has_pgid_children (0);
	  res = 0;
	}
    }

  syscall_printf ("pid %d, pgid %d, res %d", pid, pgid, res);
  return res;
}

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

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

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

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

extern "C" char *
ptsname (int fd)
{
  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;
}

static int __stdcall
mknod_worker (const char *path, mode_t type, mode_t mode, _major_t major,
	      _minor_t minor)
{
  char buf[sizeof (":\\00000000:00000000:00000000") + PATH_MAX];
  sprintf (buf, ":\\%x:%x:%x", major, minor,
	   type | (mode & (S_IRWXU | S_IRWXG | S_IRWXO)));
  return symlink_worker (buf, path, true, true);
}

extern "C" int
mknod32 (const char *path, mode_t mode, __dev32_t dev)
{
  myfault efault;
  if (efault.faulted (EFAULT))
    return -1;
  if (!*path)
    {
      set_errno (ENOENT);
      return -1;
    }

  if (strlen (path) >= PATH_MAX)
    return -1;

  path_conv w32path (path, PC_SYM_NOFOLLOW);
  if (w32path.exists ())
    {
      set_errno (EEXIST);
      return -1;
    }

  mode_t type = mode & S_IFMT;
  _major_t major = _major (dev);
  _minor_t minor = _minor (dev);
  switch (type)
    {
    case S_IFCHR:
    case S_IFBLK:
      break;

    case S_IFIFO:
      major = _major (FH_FIFO);
      minor = _minor (FH_FIFO);
      break;

    case 0:
    case S_IFREG:
      {
	int fd = open (path, O_CREAT, mode);
	if (fd < 0)
	  return -1;
	close (fd);
	return 0;
      }

    default:
      set_errno (EINVAL);
      return -1;
    }

  return mknod_worker (w32path.get_win32 (), type, mode, major, minor);
}

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)
{
  return mknod32 (path, (mode & ~S_IFMT) | S_IFIFO, 0);
}

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

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

  cygsid usersid;
  user_groups &groups = cygheap->user.groups;
  HANDLE new_token = INVALID_HANDLE_VALUE;
  struct passwd * pw_new;
  bool token_is_internal, issamesid = false;

  pw_new = internal_getpwuid (uid);
  if (!usersid.getfrompw (pw_new))
    {
      set_errno (EINVAL);
      return -1;
    }

  cygheap->user.deimpersonate ();

  /* Verify if the process token is suitable. */
  if (verify_token (hProcToken, usersid, groups))
    new_token = hProcToken;
  /* Verify if the external token is suitable */
  else if (cygheap->user.external_token != NO_IMPERSONATION
	   && 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.curr_primary_token != NO_IMPERSONATION
	   && cygheap->user.curr_primary_token != cygheap->user.external_token
	   && verify_token (cygheap->user.curr_primary_token, usersid, groups,
			    &token_is_internal))
    new_token = cygheap->user.curr_primary_token;
  /* Verify if the internal token is suitable */
  else if (cygheap->user.internal_token != NO_IMPERSONATION
	   && cygheap->user.internal_token != cygheap->user.curr_primary_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);

  /* If no impersonation token is available, try to
     authenticate using NtCreateToken () or LSA authentication. */
  if (new_token == INVALID_HANDLE_VALUE)
    {
      if (!(new_token = lsaauth (usersid, groups, pw_new)))
	{
	  debug_printf ("lsaauth failed, try create_token.");
	  new_token = create_token (usersid, groups, pw_new);
	  if (new_token == INVALID_HANDLE_VALUE)
	    {
	      debug_printf ("create_token failed, bail out of here");
	      cygheap->user.reimpersonate ();
	      return -1;
	    }
	}

      /* Keep at most one internal token */
      if (cygheap->user.internal_token != NO_IMPERSONATION)
	CloseHandle (cygheap->user.internal_token);
      cygheap->user.internal_token = new_token;
    }

  if (new_token != hProcToken)
    {
      /* Avoid having HKCU use default user */
      WCHAR name[128];
      load_registry_hive (usersid.string (name));

      /* 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");
      /* Try setting default DACL */
      PACL dacl_buf = (PACL) alloca (MAX_DACL_LEN (5));
      if (sec_acl (dacl_buf, true, true, usersid))
	{
	  TOKEN_DEFAULT_DACL tdacl = { dacl_buf };
	  if (!SetTokenInformation (new_token, TokenDefaultDacl,
				    &tdacl, sizeof (tdacl)))
	    debug_printf ("SetTokenInformation (TokenDefaultDacl), %E");
	}
    }

  issamesid = (usersid == cygheap->user.sid ());
  cygheap->user.set_sid (usersid);
  cygheap->user.curr_primary_token = new_token == hProcToken ? NO_IMPERSONATION
							: new_token;
  if (cygheap->user.curr_imp_token != NO_IMPERSONATION)
    {
      CloseHandle (cygheap->user.curr_imp_token);
      cygheap->user.curr_imp_token = NO_IMPERSONATION;
    }
  if (cygheap->user.curr_primary_token != NO_IMPERSONATION)
    {
      if (!DuplicateTokenEx (cygheap->user.curr_primary_token, MAXIMUM_ALLOWED,
			     &sec_none, SecurityImpersonation,
			     TokenImpersonation, &cygheap->user.curr_imp_token))
	{
	  __seterrno ();
	  cygheap->user.curr_primary_token = NO_IMPERSONATION;
	  return -1;
	}
      set_cygwin_privileges (cygheap->user.curr_imp_token);
    }
  if (!cygheap->user.reimpersonate ())
    {
      __seterrno ();
      return -1;
    }

  cygheap->user.set_name (pw_new->pw_name);
  myself->uid = uid;
  groups.ischanged = FALSE;
  if (!issamesid)
    user_shared_initialize (true);
  return 0;
}

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)
    {
      myself->gid = gid;
      return 0;
    }

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

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

  groups->update_pgrp (gsid);
  if (cygheap->user.issetuid ())
    {
      /* If impersonated, update impersonation token... */
      if (!SetTokenInformation (cygheap->user.primary_token (),
				TokenPrimaryGroup, &gsid, sizeof gsid))
	debug_printf ("SetTokenInformation(primary_token, "
		      "TokenPrimaryGroup), %E");
      if (!SetTokenInformation (cygheap->user.imp_token (), TokenPrimaryGroup,
				&gsid, sizeof gsid))
	debug_printf ("SetTokenInformation(token, TokenPrimaryGroup), %E");
    }
  cygheap->user.deimpersonate ();
  if (!SetTokenInformation (hProcToken, TokenPrimaryGroup, &gsid, sizeof gsid))
    debug_printf ("SetTokenInformation(hProcToken, TokenPrimaryGroup), %E");
  clear_procimptoken ();
  cygheap->user.reimpersonate ();
  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)
{
  path_conv path (newroot, PC_SYM_FOLLOW | PC_POSIX);

  int ret = -1;
  if (path.error)
    set_errno (path.error);
  else if (!path.exists ())
    set_errno (ENOENT);
  else if (!path.isdir ())
    set_errno (ENOTDIR);
  else if (path.isspecial ())
    set_errno (EPERM);
  else
    {
      getwinenv("PATH="); /* Save the native PATH */
      cygheap->root.set (path.normalized_path, path.get_win32 ());
      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)
{
  return open (path, O_WRONLY | O_CREAT | O_TRUNC, mode);
}

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

/* 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" int
setpriority (int which, id_t who, int value)
{
  DWORD prio = nice_to_winprio (value);
  int error = 0;

  switch (which)
    {
    case PRIO_PROCESS:
      if (!who)
	who = myself->pid;
      if ((pid_t) who == myself->pid)
	{
	  if (!SetPriorityClass (hMainProc, prio))
	    {
	      set_errno (EACCES);
	      return -1;
	    }
	  myself->nice = value;
	  debug_printf ("Set nice to %d", myself->nice);
	  return 0;
	}
      break;
    case PRIO_PGRP:
      if (!who)
	who = myself->pgid;
      break;
    case PRIO_USER:
      if (!who)
	who = myself->uid;
      break;
    default:
      set_errno (EINVAL);
      return -1;
    }
  winpids pids ((DWORD) PID_MAP_RW);
  for (DWORD i = 0; i < pids.npids; ++i)
    {
      _pinfo *p = pids[i];
      if (p)
	{
	  switch (which)
	    {
	    case PRIO_PROCESS:
	      if ((pid_t) who != p->pid)
		continue;
	      break;
	    case PRIO_PGRP:
	      if ((pid_t) who != p->pgid)
		continue;
	      break;
	    case PRIO_USER:
		if ((__uid32_t) who != p->uid)
		continue;
	      break;
	    }
	  HANDLE proc_h = OpenProcess (PROCESS_SET_INFORMATION, FALSE,
				       p->dwProcessId);
	  if (!proc_h)
	    error = EPERM;
	  else
	    {
	      if (!SetPriorityClass (proc_h, prio))
		error = EACCES;
	      else
		p->nice = value;
	      CloseHandle (proc_h);
	    }
	}
    }
  pids.reset ();
  if (error)
    {
      set_errno (error);
      return -1;
    }
  return 0;
}

extern "C" int
getpriority (int which, id_t who)
{
  int nice = NZERO * 2; /* Illegal value */

  switch (which)
    {
    case PRIO_PROCESS:
      if (!who)
	who = myself->pid;
      if ((pid_t) who == myself->pid)
	return myself->nice;
      break;
    case PRIO_PGRP:
      if (!who)
	who = myself->pgid;
      break;
    case PRIO_USER:
      if (!who)
	who = myself->uid;
      break;
    default:
      set_errno (EINVAL);
      return -1;
    }
  winpids pids ((DWORD) 0);
  for (DWORD i = 0; i < pids.npids; ++i)
    {
      _pinfo *p = pids[i];
      if (p)
	switch (which)
	  {
	  case PRIO_PROCESS:
	    if ((pid_t) who == p->pid)
	      {
		nice = p->nice;
		goto out;
	      }
	    break;
	  case PRIO_PGRP:
	    if ((pid_t) who == p->pgid && p->nice < nice)
	      nice = p->nice;
	    break;
	  case PRIO_USER:
	    if ((__uid32_t) who == p->uid && p->nice < nice)
	      nice = p->nice;
	      break;
	  }
    }
out:
  pids.reset ();
  if (nice == NZERO * 2)
    {
      set_errno (ESRCH);
      return -1;
    }
  return nice;
}

extern "C" int
nice (int incr)
{
  return setpriority (PRIO_PROCESS, myself->pid, myself->nice + incr);
}

/*
 * 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;
}

static void
locked_append (int fd, const void * buf, size_t size)
{
  struct __flock64 lock_buffer = {F_WRLCK, SEEK_SET, 0, 0, 0};
  int count = 0;

  do
    if ((lock_buffer.l_start = lseek64 (fd, 0, SEEK_END)) != (_off64_t) -1
	&& fcntl64 (fd, F_SETLKW, &lock_buffer) != -1)
      {
	if (lseek64 (fd, 0, SEEK_END) != (_off64_t) -1)
	  write (fd, buf, size);
	lock_buffer.l_type = F_UNLCK;
	fcntl64 (fd, F_SETLK, &lock_buffer);
	break;
      }
  while (count++ < 1000
	 && (errno == EACCES || errno == EAGAIN)
	 && !usleep (1000));
}

extern "C" void
updwtmp (const char *wtmp_file, const struct utmp *ut)
{
  int fd;

  if ((fd = open (wtmp_file, O_WRONLY | O_BINARY, 0)) >= 0)
    {
      locked_append (fd, ut, sizeof *ut);
      close (fd);
    }
}

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

static void
internal_setutent (bool force_readwrite)
{
  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 ()
{
  if (utmp_fd >= 0)
    {
      close (utmp_fd);
      utmp_fd = -1;
      utmp_readonly = false;
    }
}

extern "C" void
utmpname (const char *file)
{
  myfault efault;
  if (efault.faulted () || !*file)
    {
      debug_printf ("Invalid file");
      return;
    }
  endutent ();
  utmp_file = strdup (file);
  debug_printf ("New UTMP file: %s", utmp_file);
}
EXPORT_ALIAS (utmpname, utmpxname)

/* 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++; \
})

static struct utmpx *
copy_ut_to_utx (struct utmp *ut, struct utmpx *utx)
{
  if (!ut)
    return NULL;
  memcpy (utx, ut, sizeof *ut);
  utx->ut_tv.tv_sec = ut->ut_time;
  utx->ut_tv.tv_usec = 0;
  return utx;
}

extern "C" struct utmp *
getutent ()
{
  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)
{
  myfault efault;
  if (efault.faulted (EFAULT))
    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)
{
  myfault efault;
  if (efault.faulted (EFAULT))
    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" struct utmp *
pututline (struct utmp *ut)
{
  myfault efault;
  if (efault.faulted (EFAULT))
    return NULL;
  internal_setutent (true);
  if (utmp_fd < 0)
    {
      debug_printf ("error: utmp_fd %d", utmp_fd);
      return NULL;
    }
  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);

  struct utmp *u;
  if ((u = getutid (ut)))
    {
      lseek (utmp_fd, -sizeof *ut, SEEK_CUR);
      write (utmp_fd, ut, sizeof *ut);
    }
  else
    locked_append (utmp_fd, ut, sizeof *ut);
  return ut;
}

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

extern "C" void
endutxent ()
{
  endutent ();
}

extern "C" struct utmpx *
getutxent ()
{
  static struct utmpx utx;
  return copy_ut_to_utx (getutent (), &utx);
}

extern "C" struct utmpx *
getutxid (const struct utmpx *id)
{
  static struct utmpx utx;

  myfault efault;
  if (efault.faulted (EFAULT))
    return NULL;
  ((struct utmpx *)id)->ut_time = id->ut_tv.tv_sec;
  return copy_ut_to_utx (getutid ((struct utmp *) id), &utx);
}

extern "C" struct utmpx *
getutxline (const struct utmpx *line)
{
  static struct utmpx utx;

  myfault efault;
  if (efault.faulted (EFAULT))
    return NULL;
  ((struct utmpx *)line)->ut_time = line->ut_tv.tv_sec;
  return copy_ut_to_utx (getutline ((struct utmp *) line), &utx);
}

extern "C" struct utmpx *
pututxline (const struct utmpx *utmpx)
{
  static struct utmpx utx;

  myfault efault;
  if (efault.faulted (EFAULT))
    return NULL;
  ((struct utmpx *)utmpx)->ut_time = utmpx->ut_tv.tv_sec;
  return copy_ut_to_utx (pututline ((struct utmp *) utmpx), &utx);
}

extern "C" void
updwtmpx (const char *wtmpx_file, const struct utmpx *utmpx)
{
  ((struct utmpx *)utmpx)->ut_time = utmpx->ut_tv.tv_sec;
  updwtmp (wtmpx_file, (const struct utmp *) utmpx);
}

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;

  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]);

  /* Contrary to MSDN, NT4 requires the second argument
     or a STATUS_ACCESS_VIOLATION is generated */
  ULARGE_INTEGER availb;
  GetDiskFreeSpaceEx ("C:\\", &availb, (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;
}

#define ETC_SHELLS "/etc/shells"
static int shell_index;
static struct __sFILE64 *shell_fp;

extern "C" char *
getusershell ()
{
  /* List of default shells if no /etc/shells exists, defined as on Linux.
     FIXME: SunOS has a far longer list, containing all shells which
     might be shipped with the OS.  Should we do the same for the Cygwin
     distro, adding bash, tcsh, ksh, pdksh and zsh?  */
  static NO_COPY const char *def_shells[] = {
    "/bin/sh",
    "/bin/csh",
    "/usr/bin/sh",
    "/usr/bin/csh",
    NULL
  };
  static char buf[PATH_MAX];
  int ch, buf_idx;

  if (!shell_fp && !(shell_fp = fopen64 (ETC_SHELLS, "rt")))
    {
      if (def_shells[shell_index])
	return strcpy (buf, def_shells[shell_index++]);
      return NULL;
    }
  /* Skip white space characters. */
  while ((ch = getc (shell_fp)) != EOF && isspace (ch))
    ;
  /* Get each non-whitespace character as part of the shell path as long as
     it fits in buf. */
  for (buf_idx = 0;
       ch != EOF && !isspace (ch) && buf_idx < PATH_MAX;
       buf_idx++, ch = getc (shell_fp))
    buf[buf_idx] = ch;
  /* Skip any trailing non-whitespace character not fitting in buf.  If the
     path is longer than PATH_MAX, it's invalid anyway. */
  while (ch != EOF && !isspace (ch))
    ch = getc (shell_fp);
  if (buf_idx)
    {
      buf[buf_idx] = '\0';
      return buf;
    }
  return NULL;
}

extern "C" void
setusershell ()
{
  if (shell_fp)
    fseek (shell_fp, 0L, SEEK_SET);
  shell_index = 0;
}

extern "C" void
endusershell ()
{
  if (shell_fp)
    {
      fclose (shell_fp);
      shell_fp = NULL;
    }
  shell_index = 0;
}

extern "C" void
flockfile (FILE *file)
{
  _flockfile (file);
}

extern "C" int
ftrylockfile (FILE *file)
{
  return _ftrylockfile (file);
}

extern "C" void
funlockfile (FILE *file)
{
  _funlockfile (file);
}

extern "C" FILE *
popen (const char *command, const char *in_type)
{
  const char *type = in_type;
  char rw = *type++;

  if (*type == 'b' || *type == 't')
    type++;
  if ((rw != 'r' && rw != 'w') || (*type != '\0'))
    {
      set_errno (EINVAL);
      return NULL;
    }

  int fd, other_fd, __stdin, __stdout, stdwhat;

  int fds[2];
  if (pipe (fds) < 0)
    return NULL;

  switch (rw)
    {
    case 'r':
      __stdin = -1;
      stdwhat = 1;
      other_fd = __stdout = fds[1];
      fd = fds[0];
      break;
    case 'w':
      __stdout = -1;
      stdwhat = 0;
      other_fd = __stdin = fds[0];
      fd = fds[1];
      break;
    default:
      return NULL;	/* avoid a compiler warning */
    }

  FILE *fp = fdopen (fd, in_type);
  fcntl64 (fd, F_SETFD, fcntl64 (fd, F_GETFD, 0) | FD_CLOEXEC);

  if (!fp)
    goto err;

  pid_t pid;
  const char *argv[4];

  argv[0] = "/bin/sh";
  argv[1] = "-c";
  argv[2] = command;
  argv[3] = NULL;

  {
    lock_process now;
    int state = fcntl64 (stdwhat, F_GETFD, 0);
    fcntl64 (stdwhat, F_SETFD, state | FD_CLOEXEC);
    pid = spawn_guts ("/bin/sh", argv, cur_environ (), _P_NOWAIT,
		      __stdin, __stdout);
    fcntl64 (stdwhat, F_SETFD, state);
  }

  if (pid < 0)
    goto err;
  close (other_fd);

  fhandler_pipe *fh = (fhandler_pipe *) cygheap->fdtab[fd];
  fh->set_popen_pid (pid);

  return fp;

err:
  int save_errno = get_errno ();
  close (fds[0]);
  close (fds[1]);
  set_errno (save_errno);
  return NULL;
}

int
pclose (FILE *fp)
{
  fhandler_pipe *fh = (fhandler_pipe *) cygheap->fdtab[fileno(fp)];

  if (fh->get_device () != FH_PIPEW && fh->get_device () != FH_PIPER)
    {
      set_errno (EBADF);
      return -1;
    }

  int pid = fh->get_popen_pid ();
  if (!pid)
    {
      set_errno (ECHILD);
      return -1;
    }

  if (fclose (fp))
    return -1;

  int status;
  while (1)
    if (waitpid (pid, &status, 0) == pid)
      break;
    else if (get_errno () == EINTR)
      continue;
    else
      return -1;

  return status;
}