Mozilla/mozilla/ipc/ipcd/util/src/ipcMessageWriter.cpp
darin%meer.net 8090429064 more buffer overrun fixes
git-svn-id: svn://10.0.0.236/trunk@156545 18797224-902f-48f8-a5cc-f745e15eee43
2004-05-18 20:18:29 +00:00

120 lines
3.6 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla IPC.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 2003
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Conrad Carlen <ccarlen@netscape.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "ipcMessageWriter.h"
#include "prmem.h"
#include <string.h>
//*****************************************************************************
// ipcMessageWriter
//*****************************************************************************
ipcMessageWriter::~ipcMessageWriter()
{
if (mBuf)
free(mBuf);
}
void ipcMessageWriter::PutInt8(PRUint8 val)
{
if (EnsureCapacity(sizeof(PRUint8)))
*mBufPtr++ = val;
}
// PutInt16 and PutInt32 go to pains to avoid unaligned memory accesses that
// are larger than a byte. On some platforms, that causes a performance penalty.
// On other platforms, Tru64 for instance, it's an error.
void ipcMessageWriter::PutInt16(PRUint16 val)
{
if (EnsureCapacity(sizeof(PRUint16))) {
PRUint8 temp[2];
*(PRUint16*)temp = val;
*mBufPtr++ = temp[0];
*mBufPtr++ = temp[1];
}
}
void ipcMessageWriter::PutInt32(PRUint32 val)
{
if (EnsureCapacity(sizeof(PRUint32))) {
PRUint8 temp[4];
*(PRUint32*)temp = val;
*mBufPtr++ = temp[0];
*mBufPtr++ = temp[1];
*mBufPtr++ = temp[2];
*mBufPtr++ = temp[3];
}
}
PRUint32 ipcMessageWriter::PutBytes(const void* src, PRUint32 n)
{
if (EnsureCapacity(n)) {
memcpy(mBufPtr, src, n);
mBufPtr += n;
return n;
}
return 0;
}
PRBool ipcMessageWriter::GrowCapacity(PRInt32 sizeNeeded)
{
if (sizeNeeded < 0)
return PR_FALSE;
PRInt32 newCapacity = (mBufPtr - mBuf) + sizeNeeded;
if (mCapacity == 0)
mCapacity = newCapacity;
else
{
while (newCapacity > mCapacity && (mCapacity << 1) > 0)
mCapacity <<= 1;
if (newCapacity > mCapacity) // if we broke out because of rollover
return PR_FALSE;
}
PRInt32 curPos = mBufPtr - mBuf;
mBuf = (PRUint8*)realloc(mBuf, mCapacity);
if (!mBuf) {
mError = PR_TRUE;
return PR_FALSE;
}
mBufPtr = mBuf + curPos;
mBufEnd = mBuf + mCapacity;
return PR_TRUE;
}