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 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "@(#)opendir.c 8.2 (Berkeley) 2/12/94"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/param.h> 39 #include <sys/stat.h> 40 41 #include <dirent.h> 42 #include <errno.h> 43 #include <fcntl.h> 44 #include <stdlib.h> 45 #include <unistd.h> 46 47 /* 48 * open a directory. 49 */ 50 DIR * 51 opendir(name) 52 const char *name; 53 { 54 register DIR *dirp; 55 register int fd; 56 int saved_errno; 57 struct stat sb; 58 59 /* 60 * stat() before open() because opening of special files may be 61 * harmful. fstat() after open because the file may have changed. 62 */ 63 if (stat(name, &sb) != 0) 64 return NULL; 65 if (!S_ISDIR(sb.st_mode)) { 66 errno = ENOTDIR; 67 return NULL; 68 } 69 if ((fd = open(name, O_RDONLY | O_NONBLOCK)) == -1) 70 return NULL; 71 dirp = NULL; 72 if (fstat(fd, &sb) != 0) 73 goto fail; 74 if (!S_ISDIR(sb.st_mode)) { 75 errno = ENOTDIR; 76 goto fail; 77 } 78 if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 || 79 (dirp = malloc(sizeof(DIR))) == NULL) 80 goto fail; 81 /* 82 * Use the system page size if that is a multiple of DIRBLKSIZ 83 * this could speed things up in some cases we hope 84 */ 85 dirp->dd_len = getpagesize(); 86 if ((dirp->dd_len % DIRBLKSIZ) != 0) 87 dirp->dd_len = DIRBLKSIZ; 88 dirp->dd_buf = malloc(dirp->dd_len); 89 if (dirp->dd_buf == NULL) 90 goto fail; 91 dirp->dd_fd = fd; 92 dirp->dd_loc = 0; 93 dirp->dd_seek = 0; 94 /* 95 * Set up seek point for rewinddir. 96 */ 97 dirp->dd_rewind = telldir(dirp); 98 return dirp; 99 100 fail: 101 saved_errno = errno; 102 free(dirp); 103 close(fd); 104 errno = saved_errno; 105 return NULL; 106 } 107