gen/FreeBSD/readdir.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)readdir.c   8.3 (Berkeley) 9/29/94";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/gen/readdir.c,v 1.11 2002/02/26 21:39:32 alfred Exp $");
  39
  40 #include "namespace.h"
  41 #include <sys/param.h>
  42 #include <dirent.h>
  43 #include <errno.h>
  44 #include <string.h>
  45 #include <pthread.h>
  46 #include "un-namespace.h"
  47
  48 #include "libc_private.h"
  49
  50 /*
  51  * get next entry in a directory.
  52  */
  53 struct dirent *
  54 _readdir_unlocked(dirp)
  55         DIR *dirp;
  56 {
  57         struct dirent *dp;
  58
  59         for (;;) {
  60                 if (dirp->dd_loc >= dirp->dd_size) {
  61                         if (dirp->dd_flags & __DTF_READALL)
  62                                 return (NULL);
  63                         dirp->dd_loc = 0;
  64                 }
  65                 if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) {
  66                         dirp->dd_size = _getdirentries(dirp->dd_fd,
  67                             dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
  68                         if (dirp->dd_size <= 0)
  69                                 return (NULL);
  70                 }
  71                 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
  72                 if ((long)dp & 03L)     /* bogus pointer check */
  73                         return (NULL);
  74                 if (dp->d_reclen <= 0 ||
  75                     dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc)
  76                         return (NULL);
  77                 dirp->dd_loc += dp->d_reclen;
  78                 if (dp->d_ino == 0)
  79                         continue;
  80                 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW))
  81                         continue;
  82                 return (dp);
  83         }
  84 }
  85
  86 struct dirent *
  87 readdir(dirp)
  88         DIR *dirp;
  89 {
  90         struct dirent   *dp;
  91
  92         if (__isthreaded) {
  93                 _pthread_mutex_lock((pthread_mutex_t *)&dirp->dd_lock);
  94                 dp = _readdir_unlocked(dirp);
  95                 _pthread_mutex_unlock((pthread_mutex_t *)&dirp->dd_lock);
  96         }
  97         else
  98                 dp = _readdir_unlocked(dirp);
  99         return (dp);
 100 }
 101
 102 int
 103 readdir_r(dirp, entry, result)
 104         DIR *dirp;
 105         struct dirent *entry;
 106         struct dirent **result;
 107 {
 108         struct dirent *dp;
 109         int saved_errno;
 110
 111         saved_errno = errno;
 112         errno = 0;
 113         if (__isthreaded) {
 114                 _pthread_mutex_lock((pthread_mutex_t *)&dirp->dd_lock);
 115                 if ((dp = _readdir_unlocked(dirp)) != NULL)
 116                         memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
 117                 _pthread_mutex_unlock((pthread_mutex_t *)&dirp->dd_lock);
 118         }
 119         else if ((dp = _readdir_unlocked(dirp)) != NULL)
 120                 memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
 121
 122         if (errno != 0) {
 123                 if (dp == NULL)
 124                         return (errno);
 125         } else
 126                 errno = saved_errno;
 127
 128         if (dp != NULL)
 129                 *result = entry;
 130         else
 131                 *result = NULL;
 132
 133         return (0);
 134 }