框架上的权限被拒绝 [英] Permission denied on frame
问题描述
我有一个基于CAxWindow的窗口。在这个窗口中我创建WebBrowser控件。当DISPID_DOCUMENTCOMPLETE发生时，我做：
I have a window based on the CAxWindow. In this window I create WebBrowser control. When the DISPID_DOCUMENTCOMPLETE happens I do:
void __stdcall document_complete( LPDISPATCH pBrowser, VARIANT* )
{
CComQIPtr< IWebBrowser2 > wb( pBrowser );
CComPtr< IDispatch > doc;
if( SUCCEEDED( wb->get_Document( &doc ) ) )
{
_docs.push_back( doc );
}
...
}
当页面加载时，我调用_docs中的每个文档的脚本（IActiveScript和IActiveScriptSite）：
When the page is loaded I call for each document in _docs the script (IActiveScript and IActiveScriptSite):
function main( doc )
{
try
{
return doc.URL;
}
catch( e )
{
return "Error: " + e.description;
}
}
在某些文档上，我收到错误：Permission denied 。
使用本地代码我没有任何问题：
On some documents I get error: "Permission denied". With native code I haven't any problems:
for( auto disp : _docs )
{
CComQIPtr< IHTMLDocument2 > doc( disp );
_bstr_t url;
ATLVERIFY( SUCCEEDED( doc->get_URL( url.GetAddress() ) ) );
}
如何避免此错误？
原来，脚本不是原因：
for( auto disp : _docs )
{
CComQIPtr< IDispatchEx > doc( disp );
DISPID id = 0;
auto hr = doc->GetDispID( _bstr_t( L"URL" ), 0, &id );
// hr == E_ACCESSDENIED
}
推荐答案
据我所知，你有一个自定义脚本宿主通过活动脚本接口托管JavaScript。 JavaScript引擎使用 IDispatchEx :: Invoke 调用COM对象（每当 IDispatchEx 可用，与MSHTML doc 对象一样），并传递自己的 IServiceProvider 。我想，这是 doc 实现意识到它是从与自己的脚本不同的脚本环境中调用，并且出于安全原因（与本机代码调用不同）限制其方法。
As far as I understand, you have a custom scripting host hosting JavaScript through Active Scripting interfaces. JavaScript engine uses IDispatchEx::Invoke to call COM objects (whenever IDispatchEx is available, as with MSHTML doc object) and passes its own IServiceProvider to the call. I suppose, that's how doc implementation is aware it's being called from a scripting environment different from its own scripts, and restrict its methods for security reasons (unlike with native code calls).
我不知道有一个文件化的方法来关闭这个行为，但你可以尝试这些选项：
I'm not aware of a documented way to turn this behavior off, but you could try these options:
- 在您的
IActiveScriptSite对象上实现IServiceProvider，并将所有服务请求转发到对象（c> c c c $doc）可以从IHTMLDocument2对象获取IServiceProvider code>并将其所有调用转发到IHTMLDocument2。将包装器对象传递给您的脚本，而不是原始的doc。
- Implement
IServiceProvideron yourIActiveScriptSiteobject and forward all service requests to theIServiceProvideryou would get from theIHTMLDocument2object (doc). This may or may not work. - Wrap
docwith a native C++ object which implements onlyIDispatchand forward all its calls toIHTMLDocument2. Pass the wrapper object to your script instead of the originaldoc. Chances are high this should work.
让我们知道您是否有上述任何运气。
Let us know if you have any luck with the above.
请尝试：
class CDispatchWrapper:
public CComObjectRoot,
public IDispatch
{
// http://stackoverflow.com/questions/18718366/permission-denied-on-frame/
protected:
CDispatchWrapper() {}
struct MEMBER
{
CComPtr<IUnknown> unk;
CComPtr<ITypeInfo> ti;
};
CComPtr<ITypeLib> m_typeLib;
CComPtr<IDispatch> m_dispatch;
CSimpleMap<CComBSTR, DISPID> m_dispids;
CSimpleMap<DISPID, MEMBER> m_members;
public:
BEGIN_COM_MAP(CDispatchWrapper)
COM_INTERFACE_ENTRY(IDispatch)
END_COM_MAP()
// create and initialize
static HRESULT Create(IDispatch* dispatch, const GUID& libid, CDispatchWrapper** pp)
{
CComObject<CDispatchWrapper>* pThis = NULL;
CComObject<CDispatchWrapper>::CreateInstance(&pThis);
if (!pThis)
return E_OUTOFMEMORY;
if ( FAILED(LoadRegTypeLib(libid, 0xFFFF, 0xFFFF, 0, &pThis->m_typeLib)) )
return E_FAIL;
pThis->m_dispatch = dispatch;
(*pp = pThis)->AddRef();
return S_OK;
}
// IDispatch
STDMETHODIMP GetTypeInfoCount(UINT* pctinfo)
{
return E_NOTIMPL;
}
STDMETHODIMP GetTypeInfo(UINT itinfo, LCID lcid, ITypeInfo** pptinfo)
{
return E_NOTIMPL;
}
STDMETHODIMP GetIDsOfNames(REFIID riid, LPOLESTR* rgszNames, UINT cNames, LCID lcid, DISPID* rgdispid)
{
if ( cNames != 1 || !rgszNames || !rgszNames[0] || !*rgszNames[0] || !rgdispid )
return E_INVALIDARG;
CComBSTR name(rgszNames[0]);
if ( !name )
return E_OUTOFMEMORY;
int n = m_dispids.FindKey(name);
if ( n >= 0 )
{
DISPID dispid = m_dispids.GetValueAt(n);
if ( dispid == DISPID_UNKNOWN )
return DISP_E_UNKNOWNNAME;
rgdispid[0] = dispid;
return S_OK;
}
// find the name(s) in the typelib
UINT cMax = m_typeLib->GetTypeInfoCount();
ITypeInfo** ppTypeInfo = (ITypeInfo**)_alloca(sizeof(ITypeInfo*) * cMax);
MEMBERID* pMemberid = (MEMBERID*)_alloca(sizeof(MEMBERID*) * cMax);
USHORT cTypes = cMax;
if ( FAILED(m_typeLib->FindName(name, 0, ppTypeInfo, pMemberid, &cTypes)) || !cTypes )
return DISP_E_UNKNOWNNAME;
bool found = false;
MEMBER member;
DISPID dispid = DISPID_UNKNOWN;
for ( int i = 0; i < cTypes && !found; i++ )
{
TYPEATTR* pTypeAttr = NULL;
member.ti.Release();
member.unk.Release();
member.ti = ppTypeInfo[i];
member.ti->GetTypeAttr(&pTypeAttr);
if (pTypeAttr)
{
// check to see if m_dispatch object also implements pTypeAttr->guid interface
m_dispatch->QueryInterface(pTypeAttr->guid, (void**)&member.unk);
if (member.unk)
{
// could use pMemberid[i], but let's make sure
dispid = DISPID_UNKNOWN;
if ( SUCCEEDED(member.ti->GetIDsOfNames(rgszNames, 1, &dispid)) )
found = true;
}
member.ti->ReleaseTypeAttr(pTypeAttr);
}
}
for ( int i = 0; i < cTypes; i++ )
ppTypeInfo[i]->Release();
if (found)
{
if ( !m_dispids.Add(name, dispid) )
return E_OUTOFMEMORY;
if ( !m_members.Add(dispid, member) )
return E_OUTOFMEMORY;
rgdispid[0] = dispid;
return S_OK;
}
if ( !m_dispids.Add(name, DISPID_UNKNOWN) )
return E_OUTOFMEMORY;
return DISP_E_UNKNOWNNAME;
}
STDMETHODIMP Invoke(DISPID dispidMember, REFIID riid, LCID lcid, WORD wFlags, DISPPARAMS* pdispparams, VARIANT* pvarResult, EXCEPINFO* pexcepinfo, UINT* puArgErr)
{
int n = m_members.FindKey(dispidMember);
if ( n >= 0 )
{
const MEMBER& member = m_members.GetValueAt(n);
return member.ti->Invoke(member.unk, dispidMember, wFlags, pdispparams, pvarResult, pexcepinfo, puArgErr);
}
return DISP_E_MEMBERNOTFOUND;
}
};
用法：
CComPtr<IHTMLDocument2> doc;
// ...
// once doc != NULL, wrap it
CComPtr<CDispatchWrapper> wrapper;
CDispatchWrapper::Create(doc, LIBID_MSHTML, &wrapper);
// now pass the wrapper to the script, instead of doc
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