/* $NetBSD: readdir.c,v 1.26.42.1 2024/10/09 11:19:20 martin Exp $ */ /* * Copyright (c) 1983, 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. */ #include #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char sccsid[] = "@(#)readdir.c 8.3 (Berkeley) 9/29/94"; #else __RCSID("$NetBSD: readdir.c,v 1.26.42.1 2024/10/09 11:19:20 martin Exp $"); #endif #endif /* LIBC_SCCS and not lint */ #include "namespace.h" #include "reentrant.h" #include "extern.h" #include #include #include #include #include #include "dirent_private.h" /* * get next entry in a directory. */ struct dirent * _readdir_unlocked(DIR *dirp, int skipdeleted) { const int saved_errno = errno; struct dirent *dp; for (;;) { if (dirp->dd_loc >= dirp->dd_size) { if (dirp->dd_flags & __DTF_READALL) break; dirp->dd_loc = 0; } if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) { dirp->dd_seek = lseek(dirp->dd_fd, (off_t)0, SEEK_CUR); dirp->dd_size = getdents(dirp->dd_fd, dirp->dd_buf, (size_t)dirp->dd_len); if (dirp->dd_size == 0) /* end of directory */ break; if (dirp->dd_size == -1) /* getdents sets errno */ return NULL; if (dirp->dd_size < 0) { /* paranoia */ errno = EIO; return NULL; } } dp = (struct dirent *) (void *)(dirp->dd_buf + (size_t)dirp->dd_loc); /* bogus pointer check */ if ((intptr_t)dp & _DIRENT_ALIGN(dp)) { errno = EIO; return NULL; } /* d_reclen is unsigned; no need to compare it <= 0 */ if (dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc) { errno = EIO; return NULL; } dirp->dd_loc += dp->d_reclen; if (dp->d_ino == 0 && skipdeleted) continue; if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW)) continue; return dp; } errno = saved_errno; return NULL; } struct dirent * readdir(DIR *dirp) { struct dirent *dp; #ifdef _REENTRANT if (__isthreaded) { mutex_lock((mutex_t *)dirp->dd_lock); dp = _readdir_unlocked(dirp, 1); mutex_unlock((mutex_t *)dirp->dd_lock); } else #endif dp = _readdir_unlocked(dirp, 1); return (dp); } int readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result) { struct dirent *dp; int saved_errno; saved_errno = errno; errno = 0; #ifdef _REENTRANT if (__isthreaded) { mutex_lock((mutex_t *)dirp->dd_lock); if ((dp = _readdir_unlocked(dirp, 1)) != NULL) memcpy(entry, dp, (size_t)_DIRENT_SIZE(dp)); mutex_unlock((mutex_t *)dirp->dd_lock); } else #endif if ((dp = _readdir_unlocked(dirp, 1)) != NULL) memcpy(entry, dp, (size_t)_DIRENT_SIZE(dp)); if (errno != 0) { if (dp == NULL) return (errno); } else errno = saved_errno; if (dp != NULL) *result = entry; else *result = NULL; return (0); }