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/* $OpenBSD: opendir.c,v 1.30 2016/09/21 04:38:56 guenther Exp $ */ |
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/* |
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* Copyright (c) 1983, 1993 |
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* The Regents of the University of California. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. Neither the name of the University nor the names of its contributors |
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* may be used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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*/ |
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#include <sys/types.h> |
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#include <sys/stat.h> |
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#include <dirent.h> |
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#include <errno.h> |
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#include <fcntl.h> |
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#include <stdlib.h> |
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#include <unistd.h> |
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#include "telldir.h" |
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static DIR *__fdopendir(int fd); |
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/* |
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* Open a directory specified by name. |
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*/ |
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DIR * |
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opendir(const char *name) |
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{ |
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DIR *dirp; |
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int fd; |
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if ((fd = open(name, O_RDONLY | O_DIRECTORY | O_CLOEXEC)) == -1) |
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return (NULL); |
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dirp = __fdopendir(fd); |
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if (dirp == NULL) |
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close(fd); |
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return (dirp); |
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} |
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DEF_WEAK(opendir); |
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/* |
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* Open a directory specified by file descriptor. |
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*/ |
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DIR * |
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fdopendir(int fd) |
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{ |
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DIR *dirp; |
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int flags; |
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if ((flags = fcntl(fd, F_GETFL)) == -1) |
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return (NULL); |
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if ((flags & O_ACCMODE) != O_RDONLY && (flags & O_ACCMODE) != O_RDWR) { |
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errno = EBADF; |
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return (NULL); |
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} |
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dirp = __fdopendir(fd); |
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if (dirp != NULL) { |
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/* Record current offset for immediate telldir() */ |
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dirp->dd_bufpos = dirp->dd_curpos = lseek(fd, 0, SEEK_CUR); |
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/* |
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* POSIX doesn't require fdopendir() to set |
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* FD_CLOEXEC, so it's okay for this to fail. |
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*/ |
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(void)fcntl(fd, F_SETFD, FD_CLOEXEC); |
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} |
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return (dirp); |
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} |
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DEF_WEAK(fdopendir); |
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static DIR * |
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__fdopendir(int fd) |
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{ |
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DIR *dirp; |
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struct stat sb; |
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int pageoffset; |
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if (fstat(fd, &sb)) |
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return (NULL); |
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if (!S_ISDIR(sb.st_mode)) { |
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errno = ENOTDIR; |
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return (NULL); |
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} |
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if ((dirp = malloc(sizeof(DIR))) == NULL) |
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return (NULL); |
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pageoffset = getpagesize() - 1; |
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dirp->dd_len = ((int)sb.st_blksize * 4 + pageoffset) & ~pageoffset; |
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dirp->dd_buf = malloc(dirp->dd_len); |
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if (dirp->dd_buf == NULL) { |
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free(dirp); |
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return (NULL); |
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} |
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dirp->dd_size = 0; |
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dirp->dd_loc = 0; |
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dirp->dd_fd = fd; |
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dirp->dd_lock = NULL; |
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dirp->dd_curpos = 0; |
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dirp->dd_bufpos = 0; |
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return (dirp); |
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} |