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ef18a7a841
the user supplied buffer. this can be a problem when the user doesn't supply a full dirent and we corrupt their memory.
135 lines
3.9 KiB
C
135 lines
3.9 KiB
C
/*
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* Copyright (c) 1983, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)readdir.c 8.3 (Berkeley) 9/29/94";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "namespace.h"
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#include <sys/param.h>
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#include <dirent.h>
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#include <errno.h>
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#include <string.h>
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#include <pthread.h>
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#include "un-namespace.h"
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#include "libc_private.h"
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/*
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* get next entry in a directory.
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*/
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struct dirent *
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_readdir_unlocked(dirp)
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DIR *dirp;
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{
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struct dirent *dp;
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for (;;) {
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if (dirp->dd_loc >= dirp->dd_size) {
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if (dirp->dd_flags & __DTF_READALL)
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return (NULL);
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dirp->dd_loc = 0;
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}
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if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) {
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dirp->dd_size = _getdirentries(dirp->dd_fd,
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dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
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if (dirp->dd_size <= 0)
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return (NULL);
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}
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dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
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if ((long)dp & 03L) /* bogus pointer check */
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return (NULL);
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if (dp->d_reclen <= 0 ||
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dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc)
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return (NULL);
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dirp->dd_loc += dp->d_reclen;
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if (dp->d_ino == 0)
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continue;
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if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW))
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continue;
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return (dp);
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}
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}
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struct dirent *
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readdir(dirp)
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DIR *dirp;
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{
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struct dirent *dp;
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if (__isthreaded) {
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_pthread_mutex_lock((pthread_mutex_t *)&dirp->dd_lock);
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dp = _readdir_unlocked(dirp);
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_pthread_mutex_unlock((pthread_mutex_t *)&dirp->dd_lock);
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}
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else
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dp = _readdir_unlocked(dirp);
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return (dp);
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}
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int
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readdir_r(dirp, entry, result)
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DIR *dirp;
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struct dirent *entry;
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struct dirent **result;
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{
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struct dirent *dp;
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int saved_errno;
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saved_errno = errno;
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errno = 0;
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if (__isthreaded) {
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_pthread_mutex_lock((pthread_mutex_t *)&dirp->dd_lock);
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if ((dp = _readdir_unlocked(dirp)) != NULL)
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memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
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_pthread_mutex_unlock((pthread_mutex_t *)&dirp->dd_lock);
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}
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else if ((dp = _readdir_unlocked(dirp)) != NULL)
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memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
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if (errno != 0) {
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if (dp == NULL)
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return (errno);
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} else
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errno = saved_errno;
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if (dp != NULL)
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*result = entry;
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else
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*result = NULL;
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return (0);
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}
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