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 if ((fd = open(name, O_RDONLY | O_NONBLOCK)) == -1) 60 return NULL; 61 dirp = NULL; 62 if (fstat(fd, &sb) != 0) 63 goto fail; 64 if (!S_ISDIR(sb.st_mode)) { 65 errno = ENOTDIR; 66 goto fail; 67 } 68 if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 || 69 (dirp = malloc(sizeof(DIR))) == NULL) 70 goto fail; 71 /* 72 * If CLBYTES is an exact multiple of DIRBLKSIZ, use a CLBYTES 73 * buffer that it cluster boundary aligned. 74 * Hopefully this can be a big win someday by allowing page trades 75 * to user space to be done by getdirentries() 76 */ 77 if ((CLBYTES % DIRBLKSIZ) == 0) { 78 dirp->dd_buf = malloc(CLBYTES); 79 dirp->dd_len = CLBYTES; 80 } else { 81 dirp->dd_buf = malloc(DIRBLKSIZ); 82 dirp->dd_len = DIRBLKSIZ; 83 } 84 if (dirp->dd_buf == NULL) 85 goto fail; 86 dirp->dd_fd = fd; 87 dirp->dd_loc = 0; 88 dirp->dd_seek = 0; 89 /* 90 * Set up seek point for rewinddir. 91 */ 92 dirp->dd_rewind = telldir(dirp); 93 return dirp; 94 95 fail: 96 saved_errno = errno; 97 free(dirp); 98 close(fd); 99 errno = saved_errno; 100 return NULL; 101 } 102