toolchain/gcc/newlib/libc/posix/readdir.c

   1 #ifndef HAVE_OPENDIR
   2
   3 /*
   4  * Copyright (c) 1983 Regents of the University of California.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #if defined(LIBC_SCCS) && !defined(lint)
  37 static char sccsid[] = "@(#)readdir.c   5.7 (Berkeley) 6/1/90";
  38 #endif /* LIBC_SCCS and not lint */
  39
  40 #include <dirent.h>
  41
  42 extern int getdents (int fd, void *dp, int count);
  43
  44 /*
  45  * get next entry in a directory.
  46  */
  47 struct dirent *
  48 _DEFUN(readdir, (dirp),
  49        register DIR *dirp)
  50 {
  51   register struct dirent *dp;
  52
  53 #ifdef HAVE_DD_LOCK
  54   __lock_acquire_recursive(dirp->dd_lock);
  55 #endif
  56
  57   if (dirp->dd_fd == -1)
  58     return NULL;
  59
  60   for (;;) {
  61     if (dirp->dd_loc == 0) {
  62       dirp->dd_size = getdents (dirp->dd_fd,
  63                                 dirp->dd_buf,
  64                                 dirp->dd_len);
  65
  66       if (dirp->dd_size <= 0) {
  67 #ifdef HAVE_DD_LOCK
  68         __lock_release_recursive(dirp->dd_lock);
  69 #endif
  70         return NULL;
  71       }
  72     }
  73     if (dirp->dd_loc >= dirp->dd_size) {
  74       dirp->dd_loc = 0;
  75       continue;
  76     }
  77     dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
  78     if ((int)dp & 03) { /* bogus pointer check */
  79 #ifdef HAVE_DD_LOCK
  80       __lock_release_recursive(dirp->dd_lock);
  81 #endif
  82       return NULL;
  83     }
  84     if (dp->d_reclen <= 0 ||
  85         dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc) {
  86 #ifdef HAVE_DD_LOCK
  87       __lock_release_recursive(dirp->dd_lock);
  88 #endif
  89       return NULL;
  90     }
  91     dirp->dd_loc += dp->d_reclen;
  92     if (dp->d_ino == 0)
  93       continue;
  94 #ifdef HAVE_DD_LOCK
  95     __lock_release_recursive(dirp->dd_lock);
  96 #endif
  97     return (dp);
  98   }
  99 }
 100
 101 #endif /* ! HAVE_OPENDIR */