1 /* $NetBSD: readdir.c,v 1.25 2010/09/16 02:38:50 yamt Exp $ */ 2 3 /* 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)readdir.c 8.3 (Berkeley) 9/29/94"; 36 #else 37 __RCSID("$NetBSD: readdir.c,v 1.25 2010/09/16 02:38:50 yamt Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "namespace.h" 42 #include "reentrant.h" 43 44 #ifdef __minix 45 #include <sys/cdefs.h> 46 #include <sys/types.h> 47 #endif 48 49 #include "extern.h" 50 #include <sys/param.h> 51 52 #include <dirent.h> 53 #include <errno.h> 54 #include <string.h> 55 #include <unistd.h> 56 57 #include "dirent_private.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 for (;;) { 68 if (dirp->dd_loc >= dirp->dd_size) { 69 if (dirp->dd_flags & __DTF_READALL) 70 return (NULL); 71 dirp->dd_loc = 0; 72 } 73 if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) { 74 dirp->dd_seek = lseek(dirp->dd_fd, (off_t)0, SEEK_CUR); 75 dirp->dd_size = getdents(dirp->dd_fd, 76 dirp->dd_buf, (size_t)dirp->dd_len); 77 if (dirp->dd_size <= 0) 78 return (NULL); 79 } 80 dp = (struct dirent *) 81 (void *)(dirp->dd_buf + (size_t)dirp->dd_loc); 82 if ((intptr_t)dp & _DIRENT_ALIGN(dp))/* bogus pointer check */ 83 return (NULL); 84 /* d_reclen is unsigned; no need to compare it <= 0 */ 85 if (dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc) 86 return (NULL); 87 dirp->dd_loc += dp->d_reclen; 88 if (dp->d_ino == 0 && skipdeleted) 89 continue; 90 #ifndef __minix 91 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW)) 92 continue; 93 #endif 94 return (dp); 95 } 96 } 97 98 struct dirent * 99 readdir(dirp) 100 DIR *dirp; 101 { 102 struct dirent *dp; 103 104 #ifdef _REENTRANT 105 if (__isthreaded) { 106 mutex_lock((mutex_t *)dirp->dd_lock); 107 dp = _readdir_unlocked(dirp, 1); 108 mutex_unlock((mutex_t *)dirp->dd_lock); 109 } 110 else 111 #endif 112 dp = _readdir_unlocked(dirp, 1); 113 return (dp); 114 } 115 116 int 117 readdir_r(dirp, entry, result) 118 DIR *dirp; 119 struct dirent *entry; 120 struct dirent **result; 121 { 122 struct dirent *dp; 123 int saved_errno; 124 125 saved_errno = errno; 126 errno = 0; 127 #ifdef _REENTRANT 128 if (__isthreaded) { 129 mutex_lock((mutex_t *)dirp->dd_lock); 130 if ((dp = _readdir_unlocked(dirp, 1)) != NULL) 131 memcpy(entry, dp, (size_t)_DIRENT_SIZE(dp)); 132 mutex_unlock((mutex_t *)dirp->dd_lock); 133 } 134 else 135 #endif 136 if ((dp = _readdir_unlocked(dirp, 1)) != NULL) 137 memcpy(entry, dp, (size_t)_DIRENT_SIZE(dp)); 138 139 if (errno != 0) { 140 if (dp == NULL) 141 return (errno); 142 } else 143 errno = saved_errno; 144 145 if (dp != NULL) 146 *result = entry; 147 else 148 *result = NULL; 149 150 return (0); 151 } 152