1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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 #if defined(LIBC_SCCS) && !defined(lint) 33 static char sccsid[] = "@(#)readdir.c 8.3 (Berkeley) 9/29/94"; 34 #endif /* LIBC_SCCS and not lint */ 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include "namespace.h" 39 #include <sys/param.h> 40 #include <dirent.h> 41 #include <errno.h> 42 #include <string.h> 43 #include <pthread.h> 44 #include "un-namespace.h" 45 46 #include "libc_private.h" 47 #include "gen-private.h" 48 #include "telldir.h" 49 50 /* 51 * get next entry in a directory. 52 */ 53 struct dirent * 54 _readdir_unlocked(DIR *dirp, int flags) 55 { 56 struct dirent *dp; 57 long initial_seek; 58 long initial_loc = 0; 59 60 for (;;) { 61 if (dirp->dd_loc >= dirp->dd_size) { 62 if (dirp->dd_flags & __DTF_READALL) 63 return (NULL); 64 initial_loc = dirp->dd_loc; 65 dirp->dd_flags &= ~__DTF_SKIPREAD; 66 dirp->dd_loc = 0; 67 } 68 if (dirp->dd_loc == 0 && 69 !(dirp->dd_flags & (__DTF_READALL | __DTF_SKIPREAD))) { 70 initial_seek = dirp->dd_seek; 71 dirp->dd_size = _getdirentries(dirp->dd_fd, 72 dirp->dd_buf, dirp->dd_len, &dirp->dd_seek); 73 if (dirp->dd_size <= 0) 74 return (NULL); 75 _fixtelldir(dirp, initial_seek, initial_loc); 76 } 77 dirp->dd_flags &= ~__DTF_SKIPREAD; 78 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc); 79 if ((long)dp & 03L) /* bogus pointer check */ 80 return (NULL); 81 if (dp->d_reclen <= 0 || 82 dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc) 83 return (NULL); 84 dirp->dd_loc += dp->d_reclen; 85 if (dp->d_ino == 0 && (flags & RDU_SKIP) != 0) 86 continue; 87 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW)) 88 continue; 89 if (dp->d_namlen >= sizeof(dp->d_name) && 90 (flags & RDU_SHORT) != 0) 91 continue; 92 return (dp); 93 } 94 } 95 96 struct dirent * 97 readdir(DIR *dirp) 98 { 99 struct dirent *dp; 100 101 if (__isthreaded) 102 _pthread_mutex_lock(&dirp->dd_lock); 103 dp = _readdir_unlocked(dirp, RDU_SKIP); 104 if (__isthreaded) 105 _pthread_mutex_unlock(&dirp->dd_lock); 106 return (dp); 107 } 108 109 int 110 __readdir_r(DIR *dirp, struct dirent *entry, 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 dp = _readdir_unlocked(dirp, RDU_SKIP | RDU_SHORT); 120 if (dp != NULL) 121 memcpy(entry, dp, _GENERIC_DIRSIZ(dp)); 122 if (__isthreaded) 123 _pthread_mutex_unlock(&dirp->dd_lock); 124 125 if (errno != 0) { 126 if (dp == NULL) 127 return (errno); 128 } else 129 errno = saved_errno; 130 131 if (dp != NULL) 132 *result = entry; 133 else 134 *result = NULL; 135 136 return (0); 137 } 138 139 __strong_reference(__readdir_r, readdir_r); 140