1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * $FreeBSD: src/lib/libc/gen/opendir.c,v 1.10.2.1 2001/06/04 20:59:48 joerg Exp $ 34 * $DragonFly: src/lib/libc/gen/opendir.c,v 1.6 2005/11/13 00:07:42 swildner Exp $ 35 * 36 * @(#)opendir.c 8.8 (Berkeley) 5/1/95 37 */ 38 39 #include "namespace.h" 40 #include <sys/param.h> 41 #include <sys/stat.h> 42 43 #include <dirent.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <unistd.h> 49 #include "un-namespace.h" 50 51 /* 52 * Open a directory. 53 */ 54 DIR * 55 opendir(const char *name) 56 { 57 return (__opendir2(name, DTF_HIDEW|DTF_NODUP)); 58 } 59 60 DIR * 61 __opendir2(const char *name, int flags) 62 { 63 DIR *dirp; 64 int fd; 65 int incr; 66 int saved_errno; 67 struct stat statb; 68 69 /* 70 * stat() before _open() because opening of special files may be 71 * harmful. _fstat() after open because the file may have changed. 72 */ 73 if (stat(name, &statb) != 0) 74 return (NULL); 75 if (!S_ISDIR(statb.st_mode)) { 76 errno = ENOTDIR; 77 return (NULL); 78 } 79 if ((fd = _open(name, O_RDONLY | O_NONBLOCK)) == -1) 80 return (NULL); 81 dirp = NULL; 82 if (_fstat(fd, &statb) != 0) 83 goto fail; 84 if (!S_ISDIR(statb.st_mode)) { 85 errno = ENOTDIR; 86 goto fail; 87 } 88 if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 || 89 (dirp = malloc(sizeof(DIR))) == NULL) 90 goto fail; 91 92 /* 93 * Use the system page size if that is a multiple of DIRBLKSIZ. 94 * Hopefully this can be a big win someday by allowing page 95 * trades to user space to be done by _getdirentries(). 96 */ 97 incr = getpagesize(); 98 if ((incr % DIRBLKSIZ) != 0) 99 incr = DIRBLKSIZ; 100 101 dirp->dd_len = incr; 102 dirp->dd_buf = malloc(dirp->dd_len); 103 if (dirp->dd_buf == NULL) 104 goto fail; 105 dirp->dd_seek = 0; 106 flags &= ~DTF_REWIND; 107 108 dirp->dd_loc = 0; 109 dirp->dd_fd = fd; 110 dirp->dd_flags = flags; 111 dirp->dd_lock = NULL; 112 113 /* 114 * Set up seek point for rewinddir. 115 */ 116 dirp->dd_rewind = telldir(dirp); 117 118 return (dirp); 119 120 fail: 121 saved_errno = errno; 122 free(dirp); 123 _close(fd); 124 errno = saved_errno; 125 return (NULL); 126 } 127