Security-163.tar.gz

[apple/security.git] / SecurityServer / transwalkers.cpp

diff --git a/SecurityServer/transwalkers.cpp b/SecurityServer/transwalkers.cpp
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+/*
+ * Copyright (c) 2003 Apple Computer, Inc. All Rights Reserved.
+ * 
+ * The contents of this file constitute Original Code as defined in and are
+ * subject to the Apple Public Source License Version 1.2 (the 'License').
+ * You may not use this file except in compliance with the License. Please obtain
+ * a copy of the License at http://www.apple.com/publicsource and read it before
+ * using this file.
+ * 
+ * This Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
+ * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
+ * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+ * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
+ * specific language governing rights and limitations under the License.
+ */
+
+
+//
+// transwalkers - server side transition data walking support
+//
+// These are data walker operators for securely marshaling and unmarshaling
+// data structures across IPC. They are also in charge of fixing byte order
+// inconsistencies between server and clients.
+//
+#include <transwalkers.h>
+       
+
+using LowLevelMemoryUtilities::increment;
+using LowLevelMemoryUtilities::difference;
+
+
+bool flipClient()
+{
+       return Server::connection().process.byteFlipped();
+}
+
+
+//
+// CheckingRelocateWalkers
+//
+CheckingReconstituteWalker::CheckingReconstituteWalker(void *ptr, void *base, size_t size, bool flip)
+       : mBase(base), mFlip(flip)
+{
+       if (mFlip)
+               Flippers::flip(mBase);  // came in reversed; fix for base use
+       mOffset = difference(ptr, mBase);
+       mLimit = increment(mBase, size);
+}
+
+
+//
+// Relocation support
+//
+void relocate(Context &context, void *base, Context::Attr *attrs, uint32 attrSize)
+{
+       flip(context);
+       CheckingReconstituteWalker relocator(attrs, base, attrSize, flipClient());
+       context.ContextAttributes = attrs;      // fix context->attr vector link
+       for (uint32 n = 0; n < context.attributesInUse(); n++)
+               walk(relocator, context[n]);
+}
+
+
+//
+// Outbound flipping support
+//
+FlipWalker::~FlipWalker()
+{
+       for (set<Flipper>::const_iterator it = mFlips.begin(); it != mFlips.end(); it++)
+               delete it->impl;
+}
+
+void FlipWalker::doFlips(bool active)
+{
+       if (active) {
+               secdebug("flipwalkers", "starting outbound flips");
+               for (set<Flipper>::const_iterator it = mFlips.begin(); it != mFlips.end(); it++)
+                       it->impl->flip();
+               secdebug("flipwalkers", "outbound flips done");
+       }
+}