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 long initial_seek; 52 long initial_loc = 0; 53 54 for (;;) { 55 if (dirp->dd_loc >= dirp->dd_size) { 56 if (dirp->dd_flags & __DTF_READALL) 57 return (NULL); 58 initial_loc = dirp->dd_loc; 59 dirp->dd_flags &= ~__DTF_SKIPREAD; 60 dirp->dd_loc = 0; 61 } 62 if (dirp->dd_loc == 0 && 63 !(dirp->dd_flags & (__DTF_READALL | __DTF_SKIPREAD))) { 64 initial_seek = dirp->dd_seek; 65 dirp->dd_size = _getdirentries(dirp->dd_fd, 66 dirp->dd_buf, dirp->dd_len, &dirp->dd_seek); 67 if (dirp->dd_size <= 0) 68 return (NULL); 69 _fixtelldir(dirp, initial_seek, initial_loc); 70 } 71 dirp->dd_flags &= ~__DTF_SKIPREAD; 72 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc); 73 if ((long)dp & 03L) /* bogus pointer check */ 74 return (NULL); 75 if (dp->d_reclen <= 0 || 76 dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc) 77 return (NULL); 78 dirp->dd_loc += dp->d_reclen; 79 if (dp->d_ino == 0 && (flags & RDU_SKIP) != 0) 80 continue; 81 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW)) 82 continue; 83 if (dp->d_namlen >= sizeof(dp->d_name) && 84 (flags & RDU_SHORT) != 0) 85 continue; 86 return (dp); 87 } 88 } 89 90 struct dirent * 91 readdir(DIR *dirp) 92 { 93 struct dirent *dp; 94 95 if (__isthreaded) 96 _pthread_mutex_lock(&dirp->dd_lock); 97 dp = _readdir_unlocked(dirp, RDU_SKIP); 98 if (__isthreaded) 99 _pthread_mutex_unlock(&dirp->dd_lock); 100 return (dp); 101 } 102 103 int 104 __readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result) 105 { 106 struct dirent *dp; 107 int saved_errno; 108 109 saved_errno = errno; 110 errno = 0; 111 if (__isthreaded) 112 _pthread_mutex_lock(&dirp->dd_lock); 113 dp = _readdir_unlocked(dirp, RDU_SKIP | RDU_SHORT); 114 if (dp != NULL) 115 memcpy(entry, dp, _GENERIC_DIRSIZ(dp)); 116 if (__isthreaded) 117 _pthread_mutex_unlock(&dirp->dd_lock); 118 119 if (errno != 0) { 120 if (dp == NULL) 121 return (errno); 122 } else 123 errno = saved_errno; 124 125 if (dp != NULL) 126 *result = entry; 127 else 128 *result = NULL; 129 130 return (0); 131 } 132 133 __strong_reference(__readdir_r, readdir_r); 134