File: [local] / src / usr.bin / make / buf.c (download)
Revision 1.26, Sat Apr 25 15:33:47 2015 UTC (9 years, 1 month ago) by espie
Branch: MAIN
Changes since 1.25: +15 -2 lines
add check for overflow while doubling (very unlikely in practice, but still
better style code). Problem noticed by deraadt@ in m4.
okay doug@ deraadt@
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/* $OpenBSD: buf.c,v 1.26 2015/04/25 15:33:47 espie Exp $ */
/* $NetBSD: buf.c,v 1.9 1996/12/31 17:53:21 christos Exp $ */
/*
* Copyright (c) 1999 Marc Espie.
*
* Extensive code changes for the OpenBSD project.
*
* 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 OPENBSD PROJECT 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 OPENBSD
* PROJECT 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.
*/
/*
* Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
* Copyright (c) 1988, 1989 by Adam de Boor
* Copyright (c) 1989 by Berkeley Softworks
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Adam de Boor.
*
* 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. 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.
*/
/*-
* buf.c --
* Functions for automatically expanded buffers.
*/
#include <ctype.h>
#include <limits.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stdarg.h>
#include "config.h"
#include "defines.h"
#include "buf.h"
#include "stats.h"
#include "memory.h"
#ifdef STATS_BUF
#define DO_STAT_BUF(bp, nb) \
STAT_BUFS_EXPANSION++; \
if ((bp)->endPtr - (bp)->buffer == 1) \
STAT_WEIRD_INEFFICIENT++;
#else
#define DO_STAT_BUF(a, b)
#endif
static void
fatal_overflow()
{
fprintf(stderr, "buffer size overflow\n");
exit(2);
}
/* BufExpand(bp, nb)
* Expand buffer bp to hold upto nb additional
* chars. Makes sure there's room for an extra '\0' char at
* the end of the buffer to terminate the string. */
#define BufExpand(bp,nb) \
do { \
size_t occupied = (bp)->inPtr - (bp)->buffer; \
size_t size = (bp)->endPtr - (bp)->buffer; \
DO_STAT_BUF(bp, nb); \
\
do { \
if (size <= SIZE_MAX/2) { \
size *= 2 ; \
} else { \
fatal_overflow(); \
} \
} while (size - occupied < (nb)+1+BUF_MARGIN); \
(bp)->buffer = (bp)->inPtr = (bp)->endPtr = \
erealloc((bp)->buffer, size); \
(bp)->inPtr += occupied; \
(bp)->endPtr += size; \
} while (0);
#define BUF_DEF_SIZE 256 /* Default buffer size */
#define BUF_MARGIN 256 /* Make sure we are comfortable */
/* the hard case for Buf_AddChar: buffer must be expanded to accommodate
* one more char. */
void
BufOverflow(Buffer bp)
{
BufExpand(bp, 1);
}
void
Buf_AddChars(Buffer bp, size_t numBytes, const char *bytesPtr)
{
if ((size_t)(bp->endPtr - bp->inPtr) < numBytes+1)
BufExpand(bp, numBytes);
memcpy(bp->inPtr, bytesPtr, numBytes);
bp->inPtr += numBytes;
}
void
Buf_printf(Buffer bp, const char *fmt, ...)
{
va_list va;
int n;
va_start(va, fmt);
n = vsnprintf(bp->inPtr, bp->endPtr - bp->inPtr, fmt, va);
va_end(va);
if (n > bp->endPtr - bp->inPtr) {
va_list vb;
BufExpand(bp, n);
va_start(vb, fmt);
(void)vsnprintf(bp->inPtr, bp->endPtr - bp->inPtr, fmt, vb);
va_end(vb);
}
bp->inPtr += n;
}
void
Buf_Init(Buffer bp, size_t size)
{
#ifdef STATS_BUF
STAT_TOTAL_BUFS++;
if (size == 0)
STAT_DEFAULT_BUFS++;
if (size == 1)
STAT_WEIRD_BUFS++;
#endif
if (size == 0)
size = BUF_DEF_SIZE;
bp->inPtr = bp->endPtr = bp->buffer = emalloc(size);
bp->endPtr += size;
}