usr/src/lib/libc/port/gen/readdir.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 /*
  31  * University Copyright- Copyright (c) 1982, 1986, 1988
  32  * The Regents of the University of California
  33  * All Rights Reserved
  34  *
  35  * University Acknowledgment- Portions of this document are derived from
  36  * software developed by the University of California, Berkeley, and its
  37  * contributors.
  38  */
  39
  40 #pragma ident   "%Z%%M% %I%     %E% SMI"
  41
  42 /*
  43  * readdir -- C library extension routine
  44  */
  45
  46 #include        <sys/feature_tests.h>
  47
  48 #if !defined(_LP64)
  49 #pragma weak _readdir64 = readdir64
  50 #else
  51 #pragma weak _readdir = readdir
  52 #endif
  53
  54 #include "lint.h"
  55 #include <dirent.h>
  56 #include <limits.h>
  57 #include <errno.h>
  58 #include "libc.h"
  59
  60 #ifdef _LP64
  61
  62 dirent_t *
  63 readdir(DIR *dirp)
  64 {
  65         dirent_t *dp;   /* -> directory data */
  66         int saveloc = 0;
  67
  68         if (dirp->dd_size != 0) {
  69                 dp = (dirent_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
  70                 saveloc = dirp->dd_loc;         /* save for possible EOF */
  71                 dirp->dd_loc += (int)dp->d_reclen;
  72         }
  73         if (dirp->dd_loc >= dirp->dd_size)
  74                 dirp->dd_loc = dirp->dd_size = 0;
  75
  76         if (dirp->dd_size == 0 &&       /* refill buffer */
  77             (dirp->dd_size = getdents(dirp->dd_fd,
  78             (dirent_t *)(uintptr_t)dirp->dd_buf, DIRBUF)) <= 0) {
  79                 if (dirp->dd_size == 0)         /* This means EOF */
  80                         dirp->dd_loc = saveloc; /* so save for telldir */
  81                 return (NULL);          /* error or EOF */
  82         }
  83
  84         return ((dirent_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc]);
  85 }
  86
  87 #else   /* _LP64 */
  88
  89 /*
  90  * Welcome to the complicated world of large files on a small system.
  91  */
  92
  93 dirent64_t *
  94 readdir64(DIR *dirp)
  95 {
  96         dirent64_t *dp64;       /* -> directory data */
  97         int saveloc = 0;
  98
  99         if (dirp->dd_size != 0) {
 100                 dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
 101                 /* was converted by readdir and needs to be reversed */
 102                 if (dp64->d_ino == (ino64_t)-1) {
 103                         dirent_t *dp32;
 104
 105                         dp32 = (dirent_t *)(&dp64->d_off);
 106                         dp64->d_ino = (ino64_t)dp32->d_ino;
 107                         dp64->d_off = (off64_t)dp32->d_off;
 108                         dp64->d_reclen = (unsigned short)(dp32->d_reclen +
 109                             ((char *)&dp64->d_off - (char *)dp64));
 110                 }
 111                 saveloc = dirp->dd_loc;         /* save for possible EOF */
 112                 dirp->dd_loc += (int)dp64->d_reclen;
 113         }
 114         if (dirp->dd_loc >= dirp->dd_size)
 115                 dirp->dd_loc = dirp->dd_size = 0;
 116
 117         if (dirp->dd_size == 0 &&       /* refill buffer */
 118             (dirp->dd_size = getdents64(dirp->dd_fd,
 119             (dirent64_t *)(uintptr_t)dirp->dd_buf, DIRBUF)) <= 0) {
 120                 if (dirp->dd_size == 0)         /* This means EOF */
 121                         dirp->dd_loc = saveloc; /* so save for telldir */
 122                 return (NULL);          /* error or EOF */
 123         }
 124
 125         dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
 126         return (dp64);
 127 }
 128 #endif  /* _LP64 */