HardenedBSD/include/dirent.h
John Baldwin 9f72c0322c Fix some edge cases with rewinddir():
- In the unionfs case, opendir() and fdopendir() read the directory's full
  contents and cache it.  This cache is not refreshed when rewinddir() is
  called, so rewinddir() will not notice updates to a directory.  Fix this
  by splitting the code to fetch a directory's contents out of
  __opendir_common() into a new _filldir() function and call this from
  rewinddir() when operating on a unionfs directory.
- If rewinddir() is called on a directory opened with fdopendir() before
  any directory entries are fetched, rewinddir() will not adjust the seek
  location of the backing file descriptor.  If the file descriptor passed
  to fdopendir() had a non-zero offset, the rewinddir() will not rewind to
  the beginning.  Fix this by always seeking back to 0 in rewinddir().
  This means the dd_rewind hack can also be removed.

While here, add missing locking to rewinddir().

CR:   	    	https://phabric.freebsd.org/D312
Reviewed by:	jilles
MFC after:	1 week
2014-07-11 16:16:26 +00:00

115 lines
3.7 KiB
C

/*-
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)dirent.h 8.2 (Berkeley) 7/28/94
* $FreeBSD$
*/
#ifndef _DIRENT_H_
#define _DIRENT_H_
/*
* The kernel defines the format of directory entries returned by
* the getdirentries(2) system call.
*/
#include <sys/cdefs.h>
#include <sys/dirent.h>
#if __XSI_VISIBLE
/*
* XXX this is probably illegal in the __XSI_VISIBLE case, but brings us closer
* to the specification.
*/
#define d_ino d_fileno /* backward and XSI compatibility */
#endif
#if __BSD_VISIBLE
#include <sys/_null.h>
/* definitions for library routines operating on directories. */
#define DIRBLKSIZ 1024
struct _dirdesc;
typedef struct _dirdesc DIR;
/* flags for opendir2 */
#define DTF_HIDEW 0x0001 /* hide whiteout entries */
#define DTF_NODUP 0x0002 /* don't return duplicate names */
#define DTF_REWIND 0x0004 /* rewind after reading union stack */
#define __DTF_READALL 0x0008 /* everything has been read */
#define __DTF_SKIPREAD 0x0010 /* assume internal buffer is populated */
#else /* !__BSD_VISIBLE */
typedef void * DIR;
#endif /* __BSD_VISIBLE */
#ifndef _KERNEL
__BEGIN_DECLS
#if __POSIX_VISIBLE >= 200809 || __XSI_VISIBLE >= 700
int alphasort(const struct dirent **, const struct dirent **);
int dirfd(DIR *);
#endif
#if __BSD_VISIBLE
DIR *__opendir2(const char *, int);
int fdclosedir(DIR *);
int getdents(int, char *, int);
int getdirentries(int, char *, int, long *);
#endif
DIR *opendir(const char *);
DIR *fdopendir(int);
struct dirent *
readdir(DIR *);
#if __POSIX_VISIBLE >= 199506 || __XSI_VISIBLE >= 500
int readdir_r(DIR *, struct dirent *, struct dirent **);
#endif
void rewinddir(DIR *);
#if __POSIX_VISIBLE >= 200809 || __XSI_VISIBLE >= 700
int scandir(const char *, struct dirent ***,
int (*)(const struct dirent *), int (*)(const struct dirent **,
const struct dirent **));
#ifdef __BLOCKS__
int scandir_b(const char *, struct dirent ***,
int (^)(const struct dirent *),
int (^)(const struct dirent **, const struct dirent **));
#endif
#endif
#if __XSI_VISIBLE
void seekdir(DIR *, long);
long telldir(DIR *);
#endif
int closedir(DIR *);
__END_DECLS
#endif /* !_KERNEL */
#endif /* !_DIRENT_H_ */