gen/readdir-fbsd.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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)readdir.c   8.3 (Berkeley) 9/29/94";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/gen/readdir.c,v 1.15 2008/05/05 14:05:23 kib Exp $");
  35
  36 #include "namespace.h"
  37 #include <sys/param.h>
  38 #include <dirent.h>
  39 #include <errno.h>
  40 #include <string.h>
  41 #include <pthread.h>
  42 #include <unistd.h>
  43 #include "un-namespace.h"
  44
  45 #include "libc_private.h"
  46 #include "telldir.h"
  47
  48 /*
  49  * get next entry in a directory.
  50  */
  51 struct dirent *
  52 _readdir_unlocked(dirp, skip)
  53         DIR *dirp;
  54         int skip;
  55 {
  56         struct dirent *dp;
  57
  58         for (;;) {
  59                 if (dirp->dd_loc >= dirp->dd_size) {
  60                         if (dirp->dd_flags & __DTF_READALL)
  61                                 return (NULL);
  62                         dirp->dd_loc = 0;
  63                 }
  64                 if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) {
  65 #if __DARWIN_64_BIT_INO_T
  66                         dirp->dd_size = __getdirentries64(dirp->dd_fd,
  67                             dirp->dd_buf, dirp->dd_len, &dirp->dd_td->seekoff);
  68 #else /* !__DARWIN_64_BIT_INO_T */
  69                         dirp->dd_size = _getdirentries(dirp->dd_fd,
  70                             dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
  71 #endif /* __DARWIN_64_BIT_INO_T */
  72                         if (dirp->dd_size <= 0)
  73                                 return (NULL);
  74                 }
  75                 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
  76                 if ((long)dp & 03L)     /* bogus pointer check */
  77                         return (NULL);
  78                 if (dp->d_reclen <= 0 ||
  79                     dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc)
  80                         return (NULL);
  81                 dirp->dd_loc += dp->d_reclen;
  82                 if (dp->d_ino == 0 && skip)
  83                         continue;
  84                 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW))
  85                         continue;
  86                 return (dp);
  87         }
  88 }
  89
  90 struct dirent *
  91 readdir(dirp)
  92         DIR *dirp;
  93 {
  94         struct dirent   *dp;
  95
  96         if (__isthreaded) {
  97                 _pthread_mutex_lock(&dirp->dd_lock);
  98                 dp = _readdir_unlocked(dirp, 1);
  99                 _pthread_mutex_unlock(&dirp->dd_lock);
 100         }
 101         else
 102                 dp = _readdir_unlocked(dirp, 1);
 103         return (dp);
 104 }
 105
 106 int
 107 readdir_r(dirp, entry, result)
 108         DIR *dirp;
 109         struct dirent *entry;
 110         struct dirent **result;
 111 {
 112         struct dirent *dp;
 113         int saved_errno;
 114
 115         saved_errno = errno;
 116         errno = 0;
 117         if (__isthreaded) {
 118                 _pthread_mutex_lock(&dirp->dd_lock);
 119                 if ((dp = _readdir_unlocked(dirp, 1)) != NULL)
 120                         memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
 121                 _pthread_mutex_unlock(&dirp->dd_lock);
 122         }
 123         else if ((dp = _readdir_unlocked(dirp, 1)) != NULL)
 124                 memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
 125
 126         if (errno != 0) {
 127                 if (dp == NULL)
 128                         return (errno);
 129         } else
 130                 errno = saved_errno;
 131
 132         if (dp != NULL)
 133                 *result = entry;
 134         else
 135                 *result = NULL;
 136
 137         return (0);
 138 }