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// Copyright (c) 2009 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "app/clipboard/clipboard.h"
#include "base/logging.h"
#include "base/scoped_ptr.h"
#include "gfx/size.h"
namespace {
// A compromised renderer could send us bad data, so validate it.
// This function only checks that the size parameter makes sense, the caller
// is responsible for further validating the bitmap buffer against
// |bitmap_bytes|.
//
// |params| - Clipboard bitmap contents to validate.
// |bitmap_bytes| - On return contains the number of bytes needed to store
// the bitmap data or -1 if the data is invalid.
// returns: true if the bitmap size is valid, false otherwise.
bool IsBitmapSafe(const Clipboard::ObjectMapParams& params,
uint32* bitmap_bytes) {
*bitmap_bytes = -1;
if (params[1].size() != sizeof(gfx::Size))
return false;
const gfx::Size* size =
reinterpret_cast<const gfx::Size*>(&(params[1].front()));
uint32 total_size = size->width();
// Using INT_MAX not SIZE_T_MAX to put a reasonable bound on things.
if (INT_MAX / size->width() <= size->height())
return false;
total_size *= size->height();
if (INT_MAX / total_size <= 4)
return false;
total_size *= 4;
*bitmap_bytes = total_size;
return true;
}
// Validates a plain bitmap on the clipboard.
// Returns true if the clipboard data makes sense and it's safe to access the
// bitmap.
bool ValidatePlainBitmap(const Clipboard::ObjectMapParams& params) {
uint32 bitmap_bytes = -1;
if (!IsBitmapSafe(params, &bitmap_bytes))
return false;
if (bitmap_bytes != params[0].size())
return false;
return true;
}
// Valides a shared bitmap on the clipboard.
// Returns true if the clipboard data makes sense and it's safe to access the
// bitmap.
bool ValidateAndMapSharedBitmap(const Clipboard::ObjectMapParams& params,
base::SharedMemory* bitmap_data) {
using base::SharedMemory;
uint32 bitmap_bytes = -1;
if (!IsBitmapSafe(params, &bitmap_bytes))
return false;
if (!bitmap_data || !SharedMemory::IsHandleValid(bitmap_data->handle()))
return false;
if (!bitmap_data->Map(bitmap_bytes)) {
PLOG(ERROR) << "Failed to map bitmap memory";
return false;
}
return true;
}
} // namespace
void Clipboard::DispatchObject(ObjectType type, const ObjectMapParams& params) {
// All types apart from CBF_WEBKIT need at least 1 non-empty param.
if (type != CBF_WEBKIT && (params.empty() || params[0].empty()))
return;
// Some other types need a non-empty 2nd param.
if ((type == CBF_BOOKMARK || type == CBF_BITMAP ||
type == CBF_SMBITMAP || type == CBF_DATA) &&
(params.size() != 2 || params[1].empty()))
return;
switch (type) {
case CBF_TEXT:
WriteText(&(params[0].front()), params[0].size());
break;
case CBF_HTML:
if (params.size() == 2) {
if (params[1].empty())
return;
WriteHTML(&(params[0].front()), params[0].size(),
&(params[1].front()), params[1].size());
} else if (params.size() == 1) {
WriteHTML(&(params[0].front()), params[0].size(), NULL, 0);
}
break;
case CBF_BOOKMARK:
WriteBookmark(&(params[0].front()), params[0].size(),
&(params[1].front()), params[1].size());
break;
case CBF_WEBKIT:
WriteWebSmartPaste();
break;
case CBF_BITMAP:
if (!ValidatePlainBitmap(params))
return;
WriteBitmap(&(params[0].front()), &(params[1].front()));
break;
case CBF_SMBITMAP: {
using base::SharedMemory;
using base::SharedMemoryHandle;
if (params[0].size() != sizeof(SharedMemory*))
return;
// It's OK to cast away constness here since we map the handle as
// read-only.
const char* raw_bitmap_data_const =
reinterpret_cast<const char*>(&(params[0].front()));
char* raw_bitmap_data = const_cast<char*>(raw_bitmap_data_const);
scoped_ptr<SharedMemory> bitmap_data(
*reinterpret_cast<SharedMemory**>(raw_bitmap_data));
if (!ValidateAndMapSharedBitmap(params, bitmap_data.get()))
return;
WriteBitmap(static_cast<const char*>(bitmap_data->memory()),
&(params[1].front()));
break;
}
#if !defined(OS_MACOSX)
case CBF_DATA:
WriteData(&(params[0].front()), params[0].size(),
&(params[1].front()), params[1].size());
break;
#endif // !defined(OS_MACOSX)
default:
NOTREACHED();
}
}
// static
void Clipboard::ReplaceSharedMemHandle(ObjectMap* objects,
base::SharedMemoryHandle bitmap_handle,
base::ProcessHandle process) {
using base::SharedMemory;
bool has_shared_bitmap = false;
for (ObjectMap::iterator iter = objects->begin(); iter != objects->end();
++iter) {
if (iter->first == CBF_SMBITMAP) {
// The code currently only accepts sending a single bitmap over this way.
// Fail hard if we ever encounter more than one shared bitmap structure to
// fill.
CHECK(!has_shared_bitmap);
#if defined(OS_WIN)
SharedMemory* bitmap = new SharedMemory(bitmap_handle, true, process);
#else
SharedMemory* bitmap = new SharedMemory(bitmap_handle, true);
#endif
// We store the shared memory object pointer so it can be retrieved by the
// UI thread (see DispatchObject()).
iter->second[0].clear();
for (size_t i = 0; i < sizeof(SharedMemory*); ++i)
iter->second[0].push_back(reinterpret_cast<char*>(&bitmap)[i]);
has_shared_bitmap = true;
}
}
}
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