IHttpRequest::GetForwardedUrl Method

Returns the forwarded URL.

Syntax

virtual PCWSTR GetForwardedUrl(  
   VOID  
) const = 0;  

Parameters

This method takes no parameters.

Return Value

A pointer to a string that contains the forwarded URL.

Remarks

The GetForwardedUrl method retrieves the URL after a call to the IHttpRequest::SetUrl method, but only when the URL does not refer to a local address. If you use SetUrl to specify a local URL, the GetForwardedUrl method will return NULL.

Example

The following code example demonstrates how to create an HTTP module that calls the IHttpRequest::SetUrl method to set the URL for the request to http://www.microsoft.com. The module then calls the GetForwardedUrl method to retrieve the forwarded URL. The module tests whether the forwarded URL is NULL. If the forwarded URL is not NULL, the module displays the URL to a Web client.

#define _WINSOCKAPI_
#include <windows.h>
#include <sal.h>
#include <httpserv.h>

// Create the module class.
class MyHttpModule : public CHttpModule
{
public:
    REQUEST_NOTIFICATION_STATUS
    OnSendResponse(
        IN IHttpContext * pHttpContext,
        IN ISendResponseProvider * pProvider
    )
    {
        HRESULT hr;

        // retrieve a pointer to the request
        IHttpRequest * pHttpRequest = pHttpContext->GetRequest();

        // retrieve a pointer to the response
        IHttpResponse * pHttpResponse = pHttpContext->GetResponse();

        // test for an error
        if ((pHttpRequest != NULL) && (pHttpResponse != NULL))
        {
            // Create a buffer with an example URL.
            PCSTR pszBuffer = "http://www.microsoft.com/";
            // Set the URL for the request.
            hr = pHttpRequest->SetUrl(
                pszBuffer,(DWORD)strlen(pszBuffer),true);

            // Test for an error.
            if (FAILED(hr))
            {
                // Set the error status.
                pProvider->SetErrorStatus( hr );
                // End additional processing.
                return RQ_NOTIFICATION_FINISH_REQUEST;
            }

            PCWSTR pwszForwardedUrl = pHttpRequest->GetForwardedUrl();
            if (NULL != pwszForwardedUrl)
            {
                if (pwszForwardedUrl[0] != L'\0')
                {
                    // Allocate space for the user name.
                    PSTR pszForwardedUrl =
                        (PSTR) pHttpContext->AllocateRequestMemory(
                        (DWORD) wcslen(pwszForwardedUrl)+1 );
                    // Test for an error.
                    if (pszForwardedUrl==NULL)
                    {
                        // Set the error status.
                        pProvider->SetErrorStatus(
                            HRESULT_FROM_WIN32(ERROR_NOT_ENOUGH_MEMORY) );
                    }
                    else
                    {
                        // Clear the existing response.
                        pHttpContext->GetResponse()->Clear();
                        // Set the MIME type to plain text.
                        pHttpContext->GetResponse()->SetHeader(
                            HttpHeaderContentType,"text/plain",
                            (USHORT)strlen("text/plain"),TRUE);

                        // Return the user information to the Web client.
                        wcstombs(pszForwardedUrl,pwszForwardedUrl,
                            wcslen(pwszForwardedUrl));
                        WriteResponseMessage(pHttpContext,
                            "Forwarded URL: ",pszForwardedUrl);
                        
                        // End additional processing
                        return RQ_NOTIFICATION_FINISH_REQUEST;
                    }
                }
            }
        }
 
        // Return processing to the pipeline.
        return RQ_NOTIFICATION_CONTINUE;
    }

private:

    // Create a utility method that inserts a name/value pair into the response.
    HRESULT WriteResponseMessage(
        IHttpContext * pHttpContext,
        PCSTR pszName,
        PCSTR pszValue
    )
    {
        // Create an HRESULT to receive return values from methods.
        HRESULT hr;
        
        // Create a data chunk.
        HTTP_DATA_CHUNK dataChunk;
        // Set the chunk to a chunk in memory.
        dataChunk.DataChunkType = HttpDataChunkFromMemory;
        // Buffer for bytes written of data chunk.
        DWORD cbSent;

        // Set the chunk to the first buffer.
        dataChunk.FromMemory.pBuffer =
            (PVOID) pszName;
        // Set the chunk size to the first buffer size.
        dataChunk.FromMemory.BufferLength =
            (USHORT) strlen(pszName);
        // Insert the data chunk into the response.
        hr = pHttpContext->GetResponse()->WriteEntityChunks(
            &dataChunk,1,FALSE,TRUE,&cbSent);
        // Test for an error.
        if (FAILED(hr))
        {
            // Return the error status.
            return hr;
        }

        // Set the chunk to the second buffer.
        dataChunk.FromMemory.pBuffer =
            (PVOID) pszValue;
        // Set the chunk size to the second buffer size.
        dataChunk.FromMemory.BufferLength =
            (USHORT) strlen(pszValue);
        // Insert the data chunk into the response.
        hr = pHttpContext->GetResponse()->WriteEntityChunks(
            &dataChunk,1,FALSE,TRUE,&cbSent);
        // Test for an error.
        if (FAILED(hr))
        {
            // Return the error status.
            return hr;
        }

        // Return a success status.
        return S_OK;
    }
};

// Create the module's class factory.
class MyHttpModuleFactory : public IHttpModuleFactory
{
public:
    HRESULT
    GetHttpModule(
        OUT CHttpModule ** ppModule, 
        IN IModuleAllocator * pAllocator
    )
    {
        UNREFERENCED_PARAMETER( pAllocator );

        // Create a new instance.
        MyHttpModule * pModule = new MyHttpModule;

        // Test for an error.
        if (!pModule)
        {
            // Return an error if the factory cannot create the instance.
            return HRESULT_FROM_WIN32( ERROR_NOT_ENOUGH_MEMORY );
        }
        else
        {
            // Return a pointer to the module.
            *ppModule = pModule;
            pModule = NULL;
            // Return a success status.
            return S_OK;
        }            
    }

    void Terminate()
    {
        // Remove the class from memory.
        delete this;
    }
};

// Create the module's exported registration function.
HRESULT
__stdcall
RegisterModule(
    DWORD dwServerVersion,
    IHttpModuleRegistrationInfo * pModuleInfo,
    IHttpServer * pGlobalInfo
)
{
    UNREFERENCED_PARAMETER( dwServerVersion );
    UNREFERENCED_PARAMETER( pGlobalInfo );

    // Set the request notifications and exit.
    return pModuleInfo->SetRequestNotifications(
        new MyHttpModuleFactory,
        RQ_SEND_RESPONSE,
        0
    );
}

Your module must export the RegisterModule function. You can export this function by creating a module definition (.def) file for your project, or you can compile the module by using the /EXPORT:RegisterModule switch. For more information, see Walkthrough: Creating a Request-Level HTTP Module By Using Native Code.

You can optionally compile the code by using the __stdcall (/Gz) calling convention instead of explicitly declaring the calling convention for each function.

Requirements

Type Description
Client - IIS 7.0 on Windows Vista
- IIS 7.5 on Windows 7
- IIS 8.0 on Windows 8
- IIS 10.0 on Windows 10
Server - IIS 7.0 on Windows Server 2008
- IIS 7.5 on Windows Server 2008 R2
- IIS 8.0 on Windows Server 2012
- IIS 8.5 on Windows Server 2012 R2
- IIS 10.0 on Windows Server 2016
Product - IIS 7.0, IIS 7.5, IIS 8.0, IIS 8.5, IIS 10.0
- IIS Express 7.5, IIS Express 8.0, IIS Express 10.0
Header Httpserv.h

See Also