118 lines
3.7 KiB
C
118 lines
3.7 KiB
C
/* $NetBSD: fopen.c,v 1.15 2012/03/15 18:22:30 christos Exp $ */
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/*-
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* Copyright (c) 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Chris Torek.
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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/cdefs.h>
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#if defined(LIBC_SCCS) && !defined(lint)
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#if 0
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static char sccsid[] = "@(#)fopen.c 8.1 (Berkeley) 6/4/93";
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#else
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__RCSID("$NetBSD: fopen.c,v 1.15 2012/03/15 18:22:30 christos Exp $");
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#endif
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#endif /* LIBC_SCCS and not lint */
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <assert.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <errno.h>
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#include <limits.h>
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#include "reentrant.h"
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#include "local.h"
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FILE *
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fopen(const char *file, const char *mode)
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{
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FILE *fp;
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int f;
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int flags, oflags;
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_DIAGASSERT(file != NULL);
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if ((flags = __sflags(mode, &oflags)) == 0)
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return NULL;
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if ((fp = __sfp()) == NULL)
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return NULL;
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if ((f = open(file, oflags, DEFFILEMODE)) < 0)
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goto release;
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if (oflags & O_NONBLOCK) {
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struct stat st;
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if (fstat(f, &st) == -1) {
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int sverrno = errno;
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(void)close(f);
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errno = sverrno;
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goto release;
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}
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if (!S_ISREG(st.st_mode)) {
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(void)close(f);
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errno = EFTYPE;
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goto release;
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}
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}
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/*
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* File descriptors are a full int, but _file is only a short.
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* If we get a valid file descriptor that is greater or equal to
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* USHRT_MAX, then the fd will get sign-extended into an
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* invalid file descriptor. Handle this case by failing the
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* open. (We treat the short as unsigned, and special-case -1).
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*/
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if (f >= USHRT_MAX) {
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errno = EMFILE;
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goto release;
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}
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fp->_file = f;
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fp->_flags = flags;
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fp->_cookie = fp;
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fp->_read = __sread;
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fp->_write = __swrite;
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fp->_seek = __sseek;
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fp->_close = __sclose;
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/*
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* When opening in append mode, even though we use O_APPEND,
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* we need to seek to the end so that ftell() gets the right
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* answer. If the user then alters the seek pointer, or
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* the file extends, this will fail, but there is not much
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* we can do about this. (We could set __SAPP and check in
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* fseek and ftell.)
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*/
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if (oflags & O_APPEND)
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(void) __sseek((void *)fp, (off_t)0, SEEK_END);
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return fp;
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release:
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fp->_flags = 0; /* release */
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return NULL;
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}
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