freebsd-skq/lib/libc/stdio/stdio.c
Andrey A. Chernov e41febc84b Help to recover from bad seek (i.e. negative or too big) happens beyond
our pre-check control. Do the same way as refill.c does when it set __SERR,
i.e. clear read and ungetc buffers. Clear EOF flag too.
2001-10-24 17:25:49 +00:00

193 lines
4.5 KiB
C

/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)stdio.c 8.1 (Berkeley) 6/4/93";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <unistd.h>
#include "un-namespace.h"
#include "local.h"
/*
* Small standard I/O/seek/close functions.
*/
int
__sread(cookie, buf, n)
void *cookie;
char *buf;
int n;
{
register FILE *fp = cookie;
return(_read(fp->_file, buf, (size_t)n));
}
int
__swrite(cookie, buf, n)
void *cookie;
char const *buf;
int n;
{
register FILE *fp = cookie;
return (_write(fp->_file, buf, (size_t)n));
}
fpos_t
__sseek(cookie, offset, whence)
void *cookie;
fpos_t offset;
int whence;
{
register FILE *fp = cookie;
return (lseek(fp->_file, (off_t)offset, whence));
}
int
__sclose(cookie)
void *cookie;
{
return (_close(((FILE *)cookie)->_file));
}
/*
* Higher level wrappers.
*/
int
_sread(fp, buf, n)
FILE *fp;
char *buf;
int n;
{
int ret;
ret = (*fp->_read)(fp->_cookie, buf, n);
if (ret > 0) {
if (fp->_flags & __SOFF) {
if (fp->_offset <= OFF_MAX - ret)
fp->_offset += ret;
else
fp->_flags &= ~__SOFF;
}
} else if (ret < 0)
fp->_flags &= ~__SOFF;
return (ret);
}
int
_swrite(fp, buf, n)
FILE *fp;
char const *buf;
int n;
{
int ret;
int serrno;
if (fp->_flags & __SAPP) {
serrno = errno;
if (_sseek(fp, (fpos_t)0, SEEK_END) == -1 &&
(fp->_flags & __SOPT))
return (-1);
errno = serrno;
}
ret = (*fp->_write)(fp->_cookie, buf, n);
/* __SOFF removed even on success in case O_APPEND mode is set. */
if (ret >= 0) {
if ((fp->_flags & (__SAPP|__SOFF)) == (__SAPP|__SOFF) &&
fp->_offset <= OFF_MAX - ret)
fp->_offset += ret;
else
fp->_flags &= ~__SOFF;
} else if (ret < 0)
fp->_flags &= ~__SOFF;
return (ret);
}
fpos_t
_sseek(fp, offset, whence)
FILE *fp;
fpos_t offset;
int whence;
{
fpos_t ret;
int serrno, errret;
serrno = errno;
errno = 0;
ret = (*fp->_seek)(fp->_cookie, offset, whence);
errret = errno;
if (errno == 0)
errno = serrno;
/*
* Disallow negative seeks per POSIX.
* It is needed here to help upper level caller
* in the cases it can't detect.
*/
if (ret < 0) {
if (errret == 0) {
if (offset != 0 || whence != SEEK_CUR) {
if (HASUB(fp))
FREEUB(fp);
fp->_p = fp->_bf._base;
fp->_r = 0;
fp->_flags &= ~__SEOF;
}
fp->_flags |= __SERR;
errno = EINVAL;
} else if (errret == ESPIPE)
fp->_flags &= ~__SAPP;
fp->_flags &= ~__SOFF;
ret = -1;
} else if (fp->_flags & __SOPT) {
fp->_flags |= __SOFF;
fp->_offset = ret;
}
return (ret);
}