StdLib/PosixLib/Gen/readdir.c

   1 /** @file
   2     Get next entry in a directory.
   3
   4     Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR>
   5     This program and the accompanying materials
   6     are licensed and made available under the terms and conditions of the BSD License
   7     which accompanies this distribution.  The full text of the license may be found at
   8     http://opensource.org/licenses/bsd-license.php
   9
  10     THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11     WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13     Copyright (c) 1983, 1993
  14     The Regents of the University of California.  All rights reserved.
  15
  16     Redistribution and use in source and binary forms, with or without
  17     modification, are permitted provided that the following conditions
  18     are met:
  19     1. Redistributions of source code must retain the above copyright
  20       notice, this list of conditions and the following disclaimer.
  21     2. Redistributions in binary form must reproduce the above copyright
  22       notice, this list of conditions and the following disclaimer in the
  23       documentation and/or other materials provided with the distribution.
  24     3. Neither the name of the University nor the names of its contributors
  25       may be used to endorse or promote products derived from this software
  26       without specific prior written permission.
  27
  28     THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  29     ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31     ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  32     FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33     DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34     OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36     LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38     SUCH DAMAGE.
  39
  40     NetBSD: readdir.c,v 1.24 2008/05/04 18:53:26 tonnerre Exp
  41     readdir.c 8.3 (Berkeley) 9/29/94
  42  */
  43 #include <sys/cdefs.h>
  44
  45 #include  <namespace.h>
  46 #include  <reentrant.h>
  47 #include  <extern.h>
  48 #include <sys/param.h>
  49 #include  <sys/stdint.h>
  50
  51 #include  <stdio.h>
  52 #include <dirent.h>
  53 #include <errno.h>
  54 #include <string.h>
  55 #include <unistd.h>
  56
  57 #include  <sys/EfiSysCall.h>
  58
  59 /*
  60  * get next entry in a directory.
  61  */
  62 struct dirent *
  63 _readdir_unlocked(DIR *dirp, int skipdeleted)
  64 {
  65   struct dirent *dp;
  66
  67
  68   for (;;) {
  69     if (dirp->dd_loc >= dirp->dd_size) {
  70       if (dirp->dd_flags & __DTF_READALL)
  71         return (NULL);
  72       dirp->dd_loc = 0;
  73     }
  74     if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) {
  75       dirp->dd_size = (long)read(dirp->dd_fd, dirp->dd_buf, (size_t)dirp->dd_len);
  76       if (dirp->dd_size <= 0)
  77         return (NULL);
  78     }
  79     dp = (struct dirent *) (void *)(dirp->dd_buf + (size_t)dirp->dd_loc);
  80     if ((intptr_t)dp & _DIRENT_ALIGN(dp))/* bogus pointer check */
  81       return (NULL);
  82     dirp->dd_loc += (long)dp->Size;
  83     if ((dp->Attribute & DT_HIDDEN) && (dirp->dd_flags & DTF_HIDEW))
  84       continue;
  85     return (dp);
  86   }
  87 }
  88
  89 struct dirent *
  90 readdir(DIR *dirp)
  91 {
  92   struct dirent *dp;
  93
  94 #ifdef _REENTRANT
  95   if (__isthreaded) {
  96     mutex_lock((mutex_t *)dirp->dd_lock);
  97     dp = _readdir_unlocked(dirp, 1);
  98     mutex_unlock((mutex_t *)dirp->dd_lock);
  99   }
 100   else
 101 #endif
 102     dp = _readdir_unlocked(dirp, 1);
 103   return (dp);
 104 }
 105
 106 int
 107 readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
 108 {
 109   struct dirent *dp;
 110   int saved_errno;
 111
 112   saved_errno = errno;
 113   errno = 0;
 114 #ifdef _REENTRANT
 115   if (__isthreaded) {
 116     mutex_lock((mutex_t *)dirp->dd_lock);
 117     if ((dp = _readdir_unlocked(dirp, 1)) != NULL)
 118       memcpy(entry, dp, (size_t)_DIRENT_SIZE(dp));
 119     mutex_unlock((mutex_t *)dirp->dd_lock);
 120   }
 121   else
 122 #endif
 123     if ((dp = _readdir_unlocked(dirp, 1)) != NULL)
 124       memcpy(entry, dp, (size_t)_DIRENT_SIZE(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 }