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 #include <sys/cdefs.h> 33 __SCCSID("@(#)readdir.c 8.3 (Berkeley) 9/29/94"); 34 __FBSDID("$FreeBSD$"); 35 36 #include "namespace.h" 37 #include <sys/param.h> 38 #include <dirent.h> 39 #include <errno.h> 40 #include <string.h> 41 #include <pthread.h> 42 #include "un-namespace.h" 43 44 #include "libc_private.h" 45 #include "gen-private.h" 46 #include "telldir.h" 47 48 /* 49 * get next entry in a directory. 50 */ 51 struct dirent * 52 _readdir_unlocked(DIR *dirp, int flags) 53 { 54 struct dirent *dp; 55 long initial_seek; 56 long initial_loc = 0; 57 58 for (;;) { 59 if (dirp->dd_loc >= dirp->dd_size) { 60 if (dirp->dd_flags & __DTF_READALL) 61 return (NULL); 62 initial_loc = dirp->dd_loc; 63 dirp->dd_flags &= ~__DTF_SKIPREAD; 64 dirp->dd_loc = 0; 65 } 66 if (dirp->dd_loc == 0 && 67 !(dirp->dd_flags & (__DTF_READALL | __DTF_SKIPREAD))) { 68 initial_seek = dirp->dd_seek; 69 dirp->dd_size = _getdirentries(dirp->dd_fd, 70 dirp->dd_buf, dirp->dd_len, &dirp->dd_seek); 71 if (dirp->dd_size <= 0) 72 return (NULL); 73 _fixtelldir(dirp, initial_seek, initial_loc); 74 } 75 dirp->dd_flags &= ~__DTF_SKIPREAD; 76 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc); 77 if ((long)dp & 03L) /* bogus pointer check */ 78 return (NULL); 79 if (dp->d_reclen <= 0 || 80 dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc) 81 return (NULL); 82 dirp->dd_loc += dp->d_reclen; 83 if (dp->d_ino == 0 && (flags & RDU_SKIP) != 0) 84 continue; 85 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW)) 86 continue; 87 if (dp->d_namlen >= sizeof(dp->d_name) && 88 (flags & RDU_SHORT) != 0) 89 continue; 90 return (dp); 91 } 92 } 93 94 struct dirent * 95 readdir(DIR *dirp) 96 { 97 struct dirent *dp; 98 99 if (__isthreaded) 100 _pthread_mutex_lock(&dirp->dd_lock); 101 dp = _readdir_unlocked(dirp, RDU_SKIP); 102 if (__isthreaded) 103 _pthread_mutex_unlock(&dirp->dd_lock); 104 return (dp); 105 } 106 107 int 108 __readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result) 109 { 110 struct dirent *dp; 111 int saved_errno; 112 113 saved_errno = errno; 114 errno = 0; 115 if (__isthreaded) 116 _pthread_mutex_lock(&dirp->dd_lock); 117 dp = _readdir_unlocked(dirp, RDU_SKIP | RDU_SHORT); 118 if (dp != NULL) 119 memcpy(entry, dp, _GENERIC_DIRSIZ(dp)); 120 if (__isthreaded) 121 _pthread_mutex_unlock(&dirp->dd_lock); 122 123 if (errno != 0) { 124 if (dp == NULL) 125 return (errno); 126 } else 127 errno = saved_errno; 128 129 if (dp != NULL) 130 *result = entry; 131 else 132 *result = NULL; 133 134 return (0); 135 } 136 137 __strong_reference(__readdir_r, readdir_r); 138