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 "namespace.h" 33 #include <sys/param.h> 34 #include <dirent.h> 35 #include <errno.h> 36 #include <string.h> 37 #include <pthread.h> 38 #include "un-namespace.h" 39 40 #include "libc_private.h" 41 #include "gen-private.h" 42 #include "telldir.h" 43 44 /* 45 * get next entry in a directory. 46 */ 47 struct dirent * 48 _readdir_unlocked(DIR *dirp, int flags) 49 { 50 struct dirent *dp; 51 off_t initial_seek; 52 size_t initial_loc = 0; 53 ssize_t ret; 54 55 for (;;) { 56 if (dirp->dd_loc >= dirp->dd_size) { 57 if (dirp->dd_flags & __DTF_READALL) 58 return (NULL); 59 initial_loc = dirp->dd_loc; 60 dirp->dd_flags &= ~__DTF_SKIPREAD; 61 dirp->dd_loc = 0; 62 } 63 if (dirp->dd_loc == 0 && 64 !(dirp->dd_flags & (__DTF_READALL | __DTF_SKIPREAD))) { 65 dirp->dd_size = 0; 66 initial_seek = dirp->dd_seek; 67 ret = _getdirentries(dirp->dd_fd, 68 dirp->dd_buf, dirp->dd_len, &dirp->dd_seek); 69 if (ret <= 0) 70 return (NULL); 71 dirp->dd_size = (size_t)ret; 72 _fixtelldir(dirp, initial_seek, initial_loc); 73 } 74 dirp->dd_flags &= ~__DTF_SKIPREAD; 75 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc); 76 if ((long)dp & 03L) /* bogus pointer check */ 77 return (NULL); 78 if (dp->d_reclen <= 0 || 79 dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc) 80 return (NULL); 81 dirp->dd_loc += dp->d_reclen; 82 if (dp->d_ino == 0 && (flags & RDU_SKIP) != 0) 83 continue; 84 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW)) 85 continue; 86 if (dp->d_namlen >= sizeof(dp->d_name) && 87 (flags & RDU_SHORT) != 0) 88 continue; 89 return (dp); 90 } 91 } 92 93 struct dirent * 94 readdir(DIR *dirp) 95 { 96 struct dirent *dp; 97 98 if (__isthreaded) 99 _pthread_mutex_lock(&dirp->dd_lock); 100 dp = _readdir_unlocked(dirp, RDU_SKIP); 101 if (__isthreaded) 102 _pthread_mutex_unlock(&dirp->dd_lock); 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 if (__isthreaded) 115 _pthread_mutex_lock(&dirp->dd_lock); 116 dp = _readdir_unlocked(dirp, RDU_SKIP | RDU_SHORT); 117 if (dp != NULL) 118 memcpy(entry, dp, _GENERIC_DIRSIZ(dp)); 119 if (__isthreaded) 120 _pthread_mutex_unlock(&dirp->dd_lock); 121 122 if (errno != 0) { 123 if (dp == NULL) 124 return (errno); 125 } else 126 errno = saved_errno; 127 128 if (dp != NULL) 129 *result = entry; 130 else 131 *result = NULL; 132 133 return (0); 134 } 135 136 __strong_reference(__readdir_r, readdir_r); 137 __warn_references(readdir_r, 138 "warning: this program uses readdir_r(), which is unsafe."); 139