ISAPI Filter not working in IIS 6

External Since: Jul 29, 2004 Posts: 8

Did anything change from IIS5 - IIS 6 in the way these 2 events are processed. SF_NOTIFY_PREPROC_HEADERS and SF_NOTIFY_URL_MAP.

We have a filter for image delivery. Incoming are URL requests for specific image resolutions.
Response is a image that could be on our file system or for a low res image that we generate on the fly based on the original image. If we have the image, we respond with a UNC path. If image doesnt exist, but can be generated, we
REDIRECT with the right params to a executable.
This works perfectly on IIS5/Windows 2000.

However on IIS6/Win2003:
------------------------------
Filter loads fine with green arrow in IIS5 compatible mode. But in the case where it has to redirect, it fails with a 500 error.

In IIS 6 mode, IIS mgr doesnt seem to load the filter, but, behaviour is similar to the IIS5 comptabile mode, where the filter is able to display the image but cannot redirect in case of a low res request.

We are not using any RAW DATA events. So, i dont think we need to run in IIS5 compatible mode. Some sample code:

DWORD OnPreprocHeaders(HTTP_FILTER_CONTEXT *pFC, HTTP_FILTER_PREPROC_HEADERS *pHeaderInfo) {
// Gets the URL that the user is requesting.
if (!pHeaderInfo->GetHeader(pFC, "url", url, &dwUrl)) {
   return SF_STATUS_REQ_ERROR;
}

// look for the trigger in the url request
ParseTokenAndView(url, &tkstr, viewpath);
PhysMapStruct *pmsInfo = (PhysMapStruct *) pFC->AllocMem(pFC, sizeof(PhysMapStruct), 0);
// if the mappath starts with REDIR:
if (strncmp(mapPath, "REDIR:", 6) == 0) {
   mapPath += 6;
   pHeaderInfo->SetHeader(pFC, "url", mapPath);

   pmsInfo->physMap = false;

}

return SF_STATUS_REQ_NEXT_NOTIFICATION;
}

Please help.

External Since: Aug 25, 2003 Posts: 2419

Thanks for the summary of your filter's expected behavior.

Please describe what you are doing in SF_NOTIFY_PREPROC_HEADERS and
SF_NOTIFY_URL_MAP events. Nothing in the code you showed seems related to
your current issue.

--
//David
IIS
This posting is provided "AS IS" with no warranties, and confers no rights.
//
"Ravi" <Ravi.RemoveThis@discussions.microsoft.com> wrote in message
news:2F4FB54E-69B4-425D-8EB1-693DDDA8C728@microsoft.com...
Did anything change from IIS5 - IIS 6 in the way these 2 events are
processed. SF_NOTIFY_PREPROC_HEADERS and SF_NOTIFY_URL_MAP.

We have a filter for image delivery. Incoming are URL requests for specific
image resolutions.
Response is a image that could be on our file system or for a low res image
that we generate on the fly based on the original image. If we have the
image, we respond with a UNC path. If image doesnt exist, but can be
generated, we
REDIRECT with the right params to a executable.
This works perfectly on IIS5/Windows 2000.

However on IIS6/Win2003:
------------------------------
Filter loads fine with green arrow in IIS5 compatible mode. But in the case
where it has to redirect, it fails with a 500 error.

In IIS 6 mode, IIS mgr doesnt seem to load the filter, but, behaviour is
similar to the IIS5 comptabile mode, where the filter is able to display the
image but cannot redirect in case of a low res request.

We are not using any RAW DATA events. So, i dont think we need to run in
IIS5 compatible mode. Some sample code:

DWORD OnPreprocHeaders(HTTP_FILTER_CONTEXT *pFC, HTTP_FILTER_PREPROC_HEADERS
*pHeaderInfo) {
// Gets the URL that the user is requesting.
if (!pHeaderInfo->GetHeader(pFC, "url", url, &dwUrl)) {
return SF_STATUS_REQ_ERROR;
}

// look for the trigger in the url request
ParseTokenAndView(url, &tkstr, viewpath);
PhysMapStruct *pmsInfo = (PhysMapStruct *) pFC->AllocMem(pFC,
sizeof(PhysMapStruct), 0);
// if the mappath starts with REDIR:
if (strncmp(mapPath, "REDIR:", 6) == 0) {
mapPath += 6;
pHeaderInfo->SetHeader(pFC, "url", mapPath);

pmsInfo->physMap = false;

}

return SF_STATUS_REQ_NEXT_NOTIFICATION;
}

Please help.