1 /* $NetBSD: readdir.c,v 1.12 1998/11/13 12:31:51 christos Exp $ */ 2 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)readdir.c 8.3 (Berkeley) 9/29/94"; 40 #else 41 __RCSID("$NetBSD: readdir.c,v 1.12 1998/11/13 12:31:51 christos Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "namespace.h" 46 #include <sys/param.h> 47 #include <unistd.h> 48 #include <dirent.h> 49 50 #ifdef __weak_alias 51 __weak_alias(readdir,_readdir); 52 #endif 53 54 /* 55 * get next entry in a directory. 56 */ 57 struct dirent * 58 readdir(dirp) 59 DIR *dirp; 60 { 61 struct dirent *dp; 62 63 for (;;) { 64 if (dirp->dd_loc >= dirp->dd_size) { 65 if (dirp->dd_flags & __DTF_READALL) 66 return (NULL); 67 dirp->dd_loc = 0; 68 } 69 if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) { 70 dirp->dd_seek = lseek(dirp->dd_fd, (off_t)0, SEEK_CUR); 71 dirp->dd_size = getdents(dirp->dd_fd, 72 dirp->dd_buf, (size_t)dirp->dd_len); 73 if (dirp->dd_size <= 0) 74 return (NULL); 75 } 76 dp = (struct dirent *) 77 (void *)(dirp->dd_buf + (size_t)dirp->dd_loc); 78 if ((long)dp & 03) /* bogus pointer check */ 79 return (NULL); 80 /* d_reclen is unsigned; no need to compare it <= 0 */ 81 if (dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc) 82 return (NULL); 83 dirp->dd_loc += dp->d_reclen; 84 if (dp->d_ino == 0) 85 continue; 86 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW)) 87 continue; 88 return (dp); 89 } 90 } 91