/* dir.cc: Posix directory-related routines

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)
{
  __try
    {
      if (dir->__d_cookie == __DIRENT_COOKIE)
	return dir->__d_fd;
      syscall_printf ("-1 = dirfd (%p)", dir);
      set_errno (EINVAL);
    }
  __except (EFAULT) {}
  __endtry
  return -1;
}

/* 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->error ())
    {
      set_errno (fh->error ());
      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)
{
  int res = 0;

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

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

      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;
    }
  __except (NO_ERROR)
    {
      res = EFAULT;
    }
  __endtry
  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)
{
  __try
    {
      if (dir->__d_cookie == __DIRENT_COOKIE)
	return ((fhandler_base *) dir->__fh)->telldir (dir);
      set_errno (EBADF);
    }
  __except (EFAULT) {}
  __endtry
  return -1;
}

/* 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)
{
  __try
    {
      if (dir->__d_cookie == __DIRENT_COOKIE)
	{
	  dir->__flags &= dirent_info_mask;
	  ((fhandler_base *) dir->__fh)->seekdir (dir, loc);
	}
      set_errno (EINVAL);	/* Diagnosis */
    }
  __except (EFAULT) {}
  __endtry
}

/* 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)
{
  __try
    {
      if (dir->__d_cookie == __DIRENT_COOKIE)
	{
	  dir->__flags &= dirent_info_mask;
	  ((fhandler_base *) dir->__fh)->rewinddir (dir);
	}
      set_errno (EINVAL);	/* Diagnosis */
    }
  __except (EFAULT) {}
  __endtry
}

/* closedir: POSIX 5.1.2.1 */
extern "C" int
closedir (DIR *dir)
{
  __try
    {
      if (dir->__d_cookie == __DIRENT_COOKIE)
	{
	  /* 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;
	}
      set_errno (EBADF);
    }
  __except (EFAULT) {}
  __endtry
  syscall_printf ("%R = closedir(%p)", -1, dir);
  return -1;
}

/* 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;

  __try
    {
      if (!*dir)
	{
	  set_errno (ENOENT);
	  __leave;
	}
      /* Following Linux, and intentionally ignoring POSIX, do not
	 resolve the last component of DIR if it is a symlink, even if
	 DIR has a trailing slash.  Achieve this by stripping trailing
	 slashes or backslashes.  */
      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)))
	__leave;   /* 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 (EEXIST);
      else if (has_dot_last_component (dir, true))
	set_errno (ENOENT);
      else if (!fh->mkdir (mode))
	res = 0;
      delete fh;
    }
  __except (EFAULT) {}
  __endtry
  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;
  tmp_pathbuf tp;

  __try
    {
      if (!*dir)
	{
	  set_errno (ENOENT);
	  __leave;
	}

      /* Following Linux, and intentionally ignoring POSIX, do not
	 resolve the last component of DIR if it is a symlink, even if
	 DIR has a trailing slash.  Achieve this by stripping trailing
	 slashes or backslashes.  */
      if (isdirsep (dir[strlen (dir) - 1]))
	{
	  /* This converts // to /, but since both give ENOTEMPTY,
	     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)))
	__leave;   /* 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);
      else if (!fh->rmdir ())
	res = 0;
      delete fh;
    }
  __except (EFAULT) {}
  __endtry
  syscall_printf ("%R = rmdir(%s)", res, dir);
  return res;
}