NetBSD/lib/libc/stdio/getdelim.c

155 lines
3.9 KiB
C

/* $NetBSD: getdelim.c,v 1.14 2017/06/08 15:59:45 uwe Exp $ */
/*
* Copyright (c) 2009 The NetBSD Foundation, Inc.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Roy Marples.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: getdelim.c,v 1.14 2017/06/08 15:59:45 uwe Exp $");
#include "namespace.h"
#include <sys/param.h>
#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "reentrant.h"
#include "local.h"
#ifdef __weak_alias
__weak_alias(getdelim, _getdelim)
#endif
/* Minimum buffer size we create.
* This should allow config files to fit into our power of 2 buffer growth
* without the need for a realloc. */
#define MINBUF 128
ssize_t
__getdelim(char **__restrict buf, size_t *__restrict buflen,
int sep, FILE *__restrict fp)
{
unsigned char *p;
size_t len, newlen, off;
char *newb;
_DIAGASSERT(fp != NULL);
if (buf == NULL || buflen == NULL) {
errno = EINVAL;
goto error;
}
/* If buf is NULL, we have to assume a size of zero */
if (*buf == NULL)
*buflen = 0;
_SET_ORIENTATION(fp, -1);
off = 0;
do {
/* If the input buffer is empty, refill it */
if (fp->_r <= 0 && __srefill(fp)) {
if (__sferror(fp))
goto error;
/* No error, so EOF. */
break;
}
/* Scan through looking for the separator */
p = memchr(fp->_p, sep, (size_t)fp->_r);
if (p == NULL)
len = fp->_r;
else
len = (p - fp->_p) + 1;
newlen = off + len;
/* Ensure we can handle it */
if (newlen < off || newlen > SSIZE_MAX) {
errno = EOVERFLOW;
goto error;
}
newlen++; /* reserve space for the null terminator */
if (newlen > *buflen) {
if (newlen < MINBUF)
newlen = MINBUF;
if (!powerof2(newlen)) {
/* Grow the buffer to the next power of 2 */
newlen--;
newlen |= newlen >> 1;
newlen |= newlen >> 2;
newlen |= newlen >> 4;
newlen |= newlen >> 8;
newlen |= newlen >> 16;
#if SIZE_T_MAX > 0xffffffffU
newlen |= newlen >> 32;
#endif
newlen++;
}
newb = realloc(*buf, newlen);
if (newb == NULL)
goto error;
*buf = newb;
*buflen = newlen;
}
(void)memcpy((*buf + off), fp->_p, len);
/* Safe, len is never greater than what fp->_r can fit. */
fp->_r -= (int)len;
fp->_p += (int)len;
off += len;
} while (p == NULL);
/* POSIX demands we return -1 on EOF. */
if (off == 0)
return -1;
if (*buf != NULL)
*(*buf + off) = '\0';
return off;
error:
fp->_flags |= __SERR;
return -1;
}
ssize_t
getdelim(char **__restrict buf, size_t *__restrict buflen,
int sep, FILE *__restrict fp)
{
ssize_t n;
FLOCKFILE(fp);
n = __getdelim(buf, buflen, sep, fp);
FUNLOCKFILE(fp);
return n;
}