/* dir.cc: Posix directory-related routines

   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
   2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 Red Hat, Inc.

This file is part of Cygwin.

This software is a copyrighted work licensed under the terms of the
Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
details. */

#include "winsup.h"
#include <stdlib.h>
#include <unistd.h>

#define _COMPILING_NEWLIB
#include <dirent.h>

#include "cygerrno.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "cygtls.h"
#include "tls_pbuf.h"

extern "C" int
dirfd (DIR *dir)
{
  myfault efault;
  if (efault.faulted (EFAULT))
    return -1;
  if (dir->__d_cookie != __DIRENT_COOKIE)
    {
      set_errno (EBADF);
      syscall_printf ("-1 = dirfd (%p)", dir);
      return -1;
    }
  return dir->__d_fd;
}

/* Symbol kept for backward compatibility.  Don't remove.  Don't declare
   in public header file. */
extern "C" DIR *
__opendir_with_d_ino (const char *name)
{
  return opendir (name);
}

/* opendir: POSIX 5.1.2.1 */
extern "C" DIR *
opendir (const char *name)
{
  fhandler_base *fh;
  DIR *res;

  fh = build_fh_name (name, PC_SYM_FOLLOW);
  if (!fh)
    res = NULL;
  else if (fh->exists ())
    res = fh->opendir (-1);
  else
    {
      set_errno (ENOENT);
      res = NULL;
    }

  if (!res && fh)
    delete fh;
  /* Applications calling flock(2) on dirfd(fd) need this... */
  if (res && !fh->nohandle ())
    fh->set_unique_id ();
  return res;
}

extern "C" DIR *
fdopendir (int fd)
{
  DIR *res = NULL;

  cygheap_fdget cfd (fd);
  if (cfd >= 0)
    res = cfd->opendir (fd);
  return res;
}

static int
readdir_worker (DIR *dir, dirent *de)
{
  myfault efault;
  if (efault.faulted ())
    return EFAULT;

  if (dir->__d_cookie != __DIRENT_COOKIE)
    {
      syscall_printf ("%p = readdir (%p)", NULL, dir);
      return EBADF;
    }

  de->d_ino = 0;
  de->d_type = DT_UNKNOWN;
  memset (&de->__d_unused1, 0, sizeof (de->__d_unused1));

  int res = ((fhandler_base *) dir->__fh)->readdir (dir, de);

  if (res == ENMFILE)
    {
      if (!(dir->__flags & dirent_saw_dot))
	{
	  strcpy (de->d_name, ".");
	  dir->__flags |= dirent_saw_dot;
	  dir->__d_position++;
	  res = 0;
	}
      else if (!(dir->__flags & dirent_saw_dot_dot))
	{
	  strcpy (de->d_name, "..");
	  dir->__flags |= dirent_saw_dot_dot;
	  dir->__d_position++;
	  res = 0;
	}
    }

  if (!res && !de->d_ino)
    {
      bool is_dot = false;
      bool is_dot_dot = false;

      if (de->d_name[0] == '.')
	{
	  if (de->d_name[1] == '\0')
	    is_dot = true;
	  else if (de->d_name[1] == '.' && de->d_name[2] == '\0')
	    is_dot_dot = true;
	}

      if (is_dot_dot && !(dir->__flags & dirent_isroot))
	de->d_ino = readdir_get_ino (((fhandler_base *) dir->__fh)->get_name (),
				     true);
      else
	{
	  /* Compute d_ino by combining filename hash with directory hash. */
	  de->d_ino = ((fhandler_base *) dir->__fh)->get_ino ();
	  if (!is_dot && !is_dot_dot)
	    {
	      PUNICODE_STRING w32name =
		  ((fhandler_base *) dir->__fh)->pc.get_nt_native_path ();
	      DWORD devn = ((fhandler_base *) dir->__fh)->get_device ();
	      /* Paths below /proc don't have a Win32 pendant. */
	      if (isproc_dev (devn))
		de->d_ino = hash_path_name (de->d_ino, L"/");
	      else if (w32name->Buffer[w32name->Length / sizeof (WCHAR) - 1]
		       != L'\\')
		de->d_ino = hash_path_name (de->d_ino, L"\\");
	      de->d_ino = hash_path_name (de->d_ino, de->d_name);
	    }
	}
    }
  /* This fills out the old 32 bit d_ino field for old applications,
     build under Cygwin before 1.5.x. */
  de->__d_internal1 = de->d_ino;

  return res;
}

/* readdir: POSIX 5.1.2.1 */
extern "C" struct dirent *
readdir (DIR *dir)
{
  int res = readdir_worker (dir, dir->__d_dirent);
  if (res == 0)
    return dir->__d_dirent;
  if (res != ENMFILE)
    set_errno (res);
  return NULL;
}

extern "C" int
readdir_r (DIR *__restrict dir, dirent *__restrict de, dirent **__restrict ode)
{
  int res = readdir_worker (dir, de);
  if (!res)
    *ode = de;
  else
    {
      *ode = NULL;
      if (res == ENMFILE)
	res = 0;
    }
  return res;
}

/* telldir */
extern "C" long
telldir (DIR *dir)
{
  myfault efault;
  if (efault.faulted (EFAULT))
    return -1;

  if (dir->__d_cookie != __DIRENT_COOKIE)
    return 0;
  return ((fhandler_base *) dir->__fh)->telldir (dir);
}

/* telldir was never defined using off_t in POSIX, only in early versions
   of glibc.  We have to keep the function in as entry point for backward
   compatibility. */
extern "C" off_t
telldir64 (DIR *dir)
{
  return (off_t) telldir (dir);
}

/* seekdir */
extern "C" void
seekdir (DIR *dir, long loc)
{
  myfault efault;
  if (efault.faulted (EFAULT))
    return;

  if (dir->__d_cookie != __DIRENT_COOKIE)
    return;
  dir->__flags &= dirent_info_mask;
  return ((fhandler_base *) dir->__fh)->seekdir (dir, loc);
}

/* seekdir was never defined using off_t in POSIX, only in early versions
   of glibc.  We have to keep the function in as entry point for backward
   compatibility. */
extern "C" void
seekdir64 (DIR *dir, off_t loc)
{
  seekdir (dir, (long) loc);
}

/* rewinddir: POSIX 5.1.2.1 */
extern "C" void
rewinddir (DIR *dir)
{
  myfault efault;
  if (efault.faulted (EFAULT))
    return;

  if (dir->__d_cookie != __DIRENT_COOKIE)
    return;
  dir->__flags &= dirent_info_mask;
  return ((fhandler_base *) dir->__fh)->rewinddir (dir);
}

/* closedir: POSIX 5.1.2.1 */
extern "C" int
closedir (DIR *dir)
{
  myfault efault;
  if (efault.faulted (EFAULT))
    return -1;

  if (dir->__d_cookie != __DIRENT_COOKIE)
    {
      set_errno (EBADF);
      syscall_printf ("%R = closedir(%p)", -1, dir);
      return -1;
    }

  /* Reset the marker in case the caller tries to use `dir' again.  */
  dir->__d_cookie = 0;

  int res = ((fhandler_base *) dir->__fh)->closedir (dir);

  close (dir->__d_fd);
  free (dir->__d_dirname);
  free (dir->__d_dirent);
  free (dir);
  syscall_printf ("%R = closedir(%p)", res, dir);
  return res;
}

/* mkdir: POSIX 5.4.1.1 */
extern "C" int
mkdir (const char *dir, mode_t mode)
{
  int res = -1;
  fhandler_base *fh = NULL;
  tmp_pathbuf tp;

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

  /* POSIX says mkdir("symlink-to-missing/") should create the
     directory "missing", but Linux rejects it with EEXIST.  Copy
     Linux behavior for now.  */

  if (!*dir)
    {
      set_errno (ENOENT);
      goto done;
    }
  if (isdirsep (dir[strlen (dir) - 1]))
    {
      /* This converts // to /, but since both give EEXIST, we're okay.  */
      char *buf;
      char *p = stpcpy (buf = tp.c_get (), dir) - 1;
      dir = buf;
      while (p > dir && isdirsep (*p))
	*p-- = '\0';
    }
  if (!(fh = build_fh_name (dir, PC_SYM_NOFOLLOW)))
    goto done;   /* errno already set */;

  if (fh->error ())
    {
      debug_printf ("got %d error from build_fh_name", fh->error ());
      set_errno (fh->error ());
    }
  else if (has_dot_last_component (dir, true))
    set_errno (fh->exists () ? EEXIST : ENOENT);
  else if (!fh->mkdir (mode))
    res = 0;
  delete fh;

 done:
  syscall_printf ("%R = mkdir(%s, %d)", res, dir, mode);
  return res;
}

/* rmdir: POSIX 5.5.2.1 */
extern "C" int
rmdir (const char *dir)
{
  int res = -1;
  fhandler_base *fh = NULL;

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

  if (!(fh = build_fh_name (dir, PC_SYM_NOFOLLOW)))
    goto done;   /* errno already set */;

  if (fh->error ())
    {
      debug_printf ("got %d error from build_fh_name", fh->error ());
      set_errno (fh->error ());
    }
  else if (!fh->exists ())
    set_errno (ENOENT);
  else if (has_dot_last_component (dir, false))
    set_errno (EINVAL);
  else if (isdev_dev (fh->dev ()))
    {
      set_errno (ENOTEMPTY);
      goto done;
    }
  else if (!fh->rmdir ())
    res = 0;

  delete fh;

 done:
  syscall_printf ("%R = rmdir(%s)", res, dir);
  return res;
}