/*
* ModSecurity for Apache 2.x, http://www.modsecurity.org/
* Copyright (c) 2004-2013 Trustwave Holdings, Inc. (http://www.trustwave.com/)
*
* You may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* If any of the files related to licensing are missing or if you have any
* other questions related to licensing please contact Trustwave Holdings, Inc.
* directly using the email address security@modsecurity.org.
*/

#define WIN32_LEAN_AND_MEAN

#undef inline
#define inline inline

//  IIS7 Server API header file
#include <Windows.h>
#include <sal.h>
#include <strsafe.h>
#include "httpserv.h"

//  Project header files
#include "mymodule.h"
#include "mymodulefactory.h"

#include "api.h"
#include "moduleconfig.h"

#include "winsock2.h"

class REQUEST_STORED_CONTEXT : public IHttpStoredContext
{
 public:
    REQUEST_STORED_CONTEXT()
	{
		m_pConnRec = NULL;
		m_pRequestRec = NULL;
		m_pHttpContext = NULL;
		m_pProvider = NULL;
		m_pResponseBuffer = NULL;
		m_pResponseLength = 0;
		m_pResponsePosition = 0;
	}

    ~REQUEST_STORED_CONTEXT()
	{
		FinishRequest();
	}
    
    // virtual
    VOID
    CleanupStoredContext(
        VOID
    )
    {
		FinishRequest();
        delete this;
    }

	void FinishRequest()
	{
		if(m_pRequestRec != NULL)
		{
			modsecFinishRequest(m_pRequestRec);
			m_pRequestRec = NULL;
		}
		if(m_pConnRec != NULL)
		{
			modsecFinishConnection(m_pConnRec);
			m_pConnRec = NULL;
		}
	}

	conn_rec			*m_pConnRec;
	request_rec			*m_pRequestRec;
	IHttpContext		*m_pHttpContext;
	IHttpEventProvider	*m_pProvider;
	char				*m_pResponseBuffer;
	ULONGLONG			m_pResponseLength;
	ULONGLONG			m_pResponsePosition;
};

//----------------------------------------------------------------------------

char *GetIpAddr(apr_pool_t *pool, PSOCKADDR pAddr)
{
	const char *format = "%15[0-9.]:%5[0-9]";
	char ip[16] = { 0 };  // ip4 addresses have max len 15
	char port[6] = { 0 }; // port numbers are 16bit, ie 5 digits max

	DWORD len = 50;
	char *buf = (char *)apr_palloc(pool, len);

	if(buf == NULL)
		return "";

	buf[0] = 0;

	WSAAddressToString(pAddr, sizeof(SOCKADDR), NULL, buf, &len);

	// test for IPV4 with port on the end
	if (sscanf(buf, format, ip, port) == 2) {
		// IPV4 but with port - remove the port
		char* input = ":";
		char* ipv4 = strtok(buf, input);
		return ipv4;
	}

	return buf;
}

apr_sockaddr_t *CopySockAddr(apr_pool_t *pool, PSOCKADDR pAddr)
{
    apr_sockaddr_t *addr = (apr_sockaddr_t *)apr_palloc(pool, sizeof(apr_sockaddr_t));
	int adrlen = 16, iplen = 4;

	if(pAddr->sa_family == AF_INET6)
	{
		adrlen = 46;
		iplen = 16;
	}

	addr->addr_str_len = adrlen;
	addr->family = pAddr->sa_family;

	addr->hostname = "unknown";
#ifdef WIN32
    addr->ipaddr_len = sizeof(IN_ADDR);
#else
    addr->ipaddr_len = sizeof(struct in_addr);
#endif
    addr->ipaddr_ptr = &addr->sa.sin.sin_addr;
    addr->pool = pool;
    addr->port = 80;
#ifdef WIN32
	memcpy(&addr->sa.sin.sin_addr.S_un.S_addr, pAddr->sa_data, iplen);
#else
    memcpy(&addr->sa.sin.sin_addr.s_addr, pAddr->sa_data, iplen);
#endif
	addr->sa.sin.sin_family = pAddr->sa_family;
    addr->sa.sin.sin_port = 80;
    addr->salen = sizeof(addr->sa);
	addr->servname = addr->hostname;

	return addr;
}

//----------------------------------------------------------------------------

char *ZeroTerminate(const char *str, size_t len, apr_pool_t *pool)
{
	char *_n = (char *)apr_palloc(pool, len + 1);

	memcpy(_n, str, len);

	_n[len] = 0;

	return _n;
}

//----------------------------------------------------------------------------
// FUNCTION: ConvertUTF16ToUTF8
// DESC: Converts Unicode UTF-16 (Windows default) text to Unicode UTF-8.
//----------------------------------------------------------------------------

char *ConvertUTF16ToUTF8( __in const WCHAR * pszTextUTF16, size_t cchUTF16, apr_pool_t *pool )
{
    //
    // Special case of NULL or empty input string
    //
    if ( (pszTextUTF16 == NULL) || (*pszTextUTF16 == L'\0') || cchUTF16 == 0 )
    {
        // Return empty string
        return "";
    }

    //
    // Get size of destination UTF-8 buffer, in CHAR's (= bytes)
    //
    int cbUTF8 = ::WideCharToMultiByte(
        CP_UTF8,                // convert to UTF-8
        0,      // specify conversion behavior
        pszTextUTF16,           // source UTF-16 string
        static_cast<int>( cchUTF16 ),   // total source string length, in WCHAR's, 
        NULL,                   // unused - no conversion required in this step
        0,                      // request buffer size
        NULL, NULL              // unused
        );

    if ( cbUTF8 == 0 )
    {
		return "";
    }

    //
    // Allocate destination buffer for UTF-8 string
    //

    int cchUTF8 = cbUTF8; // sizeof(CHAR) = 1 byte

    char *pszUTF8 = (char *)apr_palloc(pool, cchUTF8 + 1 );

    //
    // Do the conversion from UTF-16 to UTF-8
    //
    int result = ::WideCharToMultiByte(
        CP_UTF8,                // convert to UTF-8
        0,      // specify conversion behavior
        pszTextUTF16,           // source UTF-16 string
        static_cast<int>( cchUTF16 ),   // total source string length, in WCHAR's, 
                                        // including end-of-string \0
        pszUTF8,                // destination buffer
        cbUTF8,                 // destination buffer size, in bytes
        NULL, NULL              // unused
        );  

    if ( result == 0 )
    {
		return "";
    }

	pszUTF8[cchUTF8] =  0;

    return pszUTF8;
}
 
void Log(void *obj, int level, char *str)
{
	CMyHttpModule *mod = (CMyHttpModule *)obj;
	WORD logcat = EVENTLOG_INFORMATION_TYPE;

	level &= APLOG_LEVELMASK;

	if(level <= APLOG_ERR)
		logcat = EVENTLOG_ERROR_TYPE;

	if(level == APLOG_WARNING || strstr(str, "Warning.") != NULL)
		logcat = EVENTLOG_WARNING_TYPE;

	mod->WriteEventViewerLog(str, logcat);
}

#define NOTE_IIS "iis-tx-context"

void StoreIISContext(request_rec *r, REQUEST_STORED_CONTEXT *rsc)
{
    apr_table_setn(r->notes, NOTE_IIS, (const char *)rsc);
}

REQUEST_STORED_CONTEXT *RetrieveIISContext(request_rec *r)
{
    REQUEST_STORED_CONTEXT *msr = NULL;
    request_rec *rx = NULL;

    /* Look in the current request first. */
    msr = (REQUEST_STORED_CONTEXT *)apr_table_get(r->notes, NOTE_IIS);
    if (msr != NULL) {
        //msr->r = r;
        return msr;
    }

    /* If this is a subrequest then look in the main request. */
    if (r->main != NULL) {
        msr = (REQUEST_STORED_CONTEXT *)apr_table_get(r->main->notes, NOTE_IIS);
        if (msr != NULL) {
            //msr->r = r;
            return msr;
        }
    }

    /* If the request was redirected then look in the previous requests. */
    rx = r->prev;
    while(rx != NULL) {
        msr = (REQUEST_STORED_CONTEXT *)apr_table_get(rx->notes, NOTE_IIS);
        if (msr != NULL) {
            //msr->r = r;
            return msr;
        }
        rx = rx->prev;
    }

    return NULL;
}

HRESULT CMyHttpModule::ReadFileChunk(HTTP_DATA_CHUNK *chunk, char *buf)
{
    OVERLAPPED ovl;
    DWORD dwDataStartOffset;
    ULONGLONG bytesTotal = 0;
	BYTE *	pIoBuffer = NULL;
	HANDLE	hIoEvent = INVALID_HANDLE_VALUE;
	HRESULT hr = S_OK;

    pIoBuffer = (BYTE *)VirtualAlloc(NULL,
                                        1,
                                        MEM_COMMIT | MEM_RESERVE,
                                        PAGE_READWRITE);
    if (pIoBuffer == NULL)
    {
        hr = HRESULT_FROM_WIN32(GetLastError());
		goto Done;
    }

    hIoEvent = CreateEvent(NULL,  // security attr
                                FALSE, // manual reset
                                FALSE, // initial state
                                NULL); // name
    if (hIoEvent == NULL)
    {
        hr = HRESULT_FROM_WIN32(GetLastError());
		goto Done;
    }

	while(bytesTotal < chunk->FromFileHandle.ByteRange.Length.QuadPart)
	{
		DWORD bytesRead = 0;
		int was_eof = 0;
		ULONGLONG offset = chunk->FromFileHandle.ByteRange.StartingOffset.QuadPart + bytesTotal;

		ZeroMemory(&ovl, sizeof ovl);
		ovl.hEvent     = hIoEvent;
		ovl.Offset = (DWORD)offset;
		dwDataStartOffset = ovl.Offset & (m_dwPageSize - 1);
		ovl.Offset &= ~(m_dwPageSize - 1);
		ovl.OffsetHigh = offset >> 32;

		if (!ReadFile(chunk->FromFileHandle.FileHandle,
					  pIoBuffer,
					  m_dwPageSize,
					  &bytesRead,
					  &ovl))
		{
			DWORD dwErr = GetLastError();

			switch (dwErr)
			{
			case ERROR_IO_PENDING:
				//
				// GetOverlappedResult can return without waiting for the
				// event thus leaving it signalled and causing problems
				// with future use of that event handle, so just wait ourselves
				//
				WaitForSingleObject(ovl.hEvent, INFINITE); // == WAIT_OBJECT_0);

				if (!GetOverlappedResult(
						 chunk->FromFileHandle.FileHandle,
						 &ovl,
						 &bytesRead,
						 TRUE))
				{
					dwErr = GetLastError();

					switch(dwErr)
					{
					case ERROR_HANDLE_EOF:
						was_eof = 1;
						break;

					default:
						hr = HRESULT_FROM_WIN32(dwErr);
						goto Done;
					}
				}
				break;

			case ERROR_HANDLE_EOF:
				was_eof = 1;
				break;

			default:
				hr = HRESULT_FROM_WIN32(dwErr);
				goto Done;
			}
		}

		bytesRead -= dwDataStartOffset;

		if (bytesRead > chunk->FromFileHandle.ByteRange.Length.QuadPart)
		{
			bytesRead = (DWORD)chunk->FromFileHandle.ByteRange.Length.QuadPart;
		}
		if ((bytesTotal + bytesRead) > chunk->FromFileHandle.ByteRange.Length.QuadPart)
		{ 
			bytesRead = chunk->FromFileHandle.ByteRange.Length.QuadPart - bytesTotal; 
		}

		memcpy(buf, pIoBuffer + dwDataStartOffset, bytesRead);

		buf += bytesRead;
		bytesTotal += bytesRead;

		if(was_eof != 0)
			chunk->FromFileHandle.ByteRange.Length.QuadPart = bytesTotal;
	}

Done:
	if(NULL != pIoBuffer)
	{
		VirtualFree(pIoBuffer, 0, MEM_RELEASE);
	}

	if(INVALID_HANDLE_VALUE != hIoEvent)
	{
		CloseHandle(hIoEvent);
	}

	return hr;
}

REQUEST_NOTIFICATION_STATUS
CMyHttpModule::OnSendResponse(
    IN IHttpContext * pHttpContext,
    IN ISendResponseProvider * pResponseProvider
)
{
	REQUEST_STORED_CONTEXT *rsc = NULL;

	rsc = (REQUEST_STORED_CONTEXT *)pHttpContext->GetModuleContextContainer()->GetModuleContext(g_pModuleContext);

	EnterCriticalSection(&m_csLock);

	// here we must check if response body processing is enabled
	//
	if(rsc == NULL || rsc->m_pRequestRec == NULL || rsc->m_pResponseBuffer != NULL || !modsecIsResponseBodyAccessEnabled(rsc->m_pRequestRec))
	{
		goto Exit;
	}

    HRESULT hr = S_OK;
	IHttpResponse *pHttpResponse = NULL;
    HTTP_RESPONSE *pRawHttpResponse = NULL;
    HTTP_BYTE_RANGE *pFileByteRange = NULL;
    HTTP_DATA_CHUNK *pSourceDataChunk = NULL;
    LARGE_INTEGER  lFileSize;
    REQUEST_NOTIFICATION_STATUS ret = RQ_NOTIFICATION_CONTINUE;
	ULONGLONG ulTotalLength = 0;
	DWORD c;
	request_rec *r = rsc->m_pRequestRec;

	pHttpResponse = pHttpContext->GetResponse();
	pRawHttpResponse = pHttpResponse->GetRawHttpResponse();

	// here we must add handling of chunked response
	// apparently IIS 7 calls this handler once per chunk
	// see: http://stackoverflow.com/questions/4385249/how-to-buffer-and-process-chunked-data-before-sending-headers-in-iis7-native-mod

	if(pRawHttpResponse->EntityChunkCount == 0)
		goto Exit;

	// here we must transfer response headers
	//
	USHORT ctcch = 0;
	char *ct = (char *)pHttpResponse->GetHeader(HttpHeaderContentType, &ctcch);
	char *ctz = ZeroTerminate(ct, ctcch, r->pool);

	// assume HTML if content type not set
	// without this output filter would not buffer response and processing would hang
	//
	if(ctz[0] == 0)
		ctz = "text/html";

	r->content_type = ctz;

#define _TRANSHEADER(id,str) if(pRawHttpResponse->Headers.KnownHeaders[id].pRawValue != NULL) \
	{\
		apr_table_setn(r->headers_out, str, \
			ZeroTerminate(pRawHttpResponse->Headers.KnownHeaders[id].pRawValue, pRawHttpResponse->Headers.KnownHeaders[id].RawValueLength, r->pool)); \
	}

    _TRANSHEADER(HttpHeaderCacheControl, "Cache-Control");
    _TRANSHEADER(HttpHeaderConnection, "Connection");
    _TRANSHEADER(HttpHeaderDate, "Date");
    _TRANSHEADER(HttpHeaderKeepAlive, "Keep-Alive");             
    _TRANSHEADER(HttpHeaderPragma, "Pragma");                
    _TRANSHEADER(HttpHeaderTrailer, "Trailer");               
    _TRANSHEADER(HttpHeaderTransferEncoding, "Transfer-Encoding");      
    _TRANSHEADER(HttpHeaderUpgrade, "Upgrade");               
    _TRANSHEADER(HttpHeaderVia, "Via");                   
    _TRANSHEADER(HttpHeaderWarning, "Warning");               
    _TRANSHEADER(HttpHeaderAllow, "Allow");                 
    _TRANSHEADER(HttpHeaderContentLength, "Content-Length");         
    _TRANSHEADER(HttpHeaderContentType, "Content-Type");           
    _TRANSHEADER(HttpHeaderContentEncoding, "Content-Encoding");       
    _TRANSHEADER(HttpHeaderContentLanguage, "Content-Language");       
    _TRANSHEADER(HttpHeaderContentLocation, "Content-Location");       
    _TRANSHEADER(HttpHeaderContentMd5, "Content-Md5");            
    _TRANSHEADER(HttpHeaderContentRange, "Content-Range");          
    _TRANSHEADER(HttpHeaderExpires, "Expires");               
    _TRANSHEADER(HttpHeaderLastModified, "Last-Modified");          
	_TRANSHEADER(HttpHeaderAcceptRanges, "Accept-Ranges");
    _TRANSHEADER(HttpHeaderAge, "Age");                   
    _TRANSHEADER(HttpHeaderEtag, "Etag");                  
    _TRANSHEADER(HttpHeaderLocation, "Location");              
    _TRANSHEADER(HttpHeaderProxyAuthenticate, "Proxy-Authenticate");     
    _TRANSHEADER(HttpHeaderRetryAfter, "Retry-After");            
    _TRANSHEADER(HttpHeaderServer, "Server");                
    _TRANSHEADER(HttpHeaderSetCookie, "Set-Cookie");             
    _TRANSHEADER(HttpHeaderVary, "Vary");                  
    _TRANSHEADER(HttpHeaderWwwAuthenticate, "Www-Authenticate");

#undef	_TRANSHEADER

	for(int i = 0; i < pRawHttpResponse->Headers.UnknownHeaderCount; i++)
	{
		apr_table_setn(r->headers_out, 
			ZeroTerminate(pRawHttpResponse->Headers.pUnknownHeaders[i].pName, pRawHttpResponse->Headers.pUnknownHeaders[i].NameLength, r->pool), 
			ZeroTerminate(pRawHttpResponse->Headers.pUnknownHeaders[i].pRawValue, pRawHttpResponse->Headers.pUnknownHeaders[i].RawValueLength, r->pool));
	}

	r->content_encoding = apr_table_get(r->headers_out, "Content-Encoding");
	//r->content_type = apr_table_get(r->headers_out, "Content-Type");		-- already set above

	const char *lng = apr_table_get(r->headers_out, "Content-Languages");

	if(lng != NULL)
	{
		r->content_languages = apr_array_make(r->pool, 1, sizeof(const char *));

		*(const char **)apr_array_push(r->content_languages) = lng;
	}

	// Disable kernel caching for this response
	// Probably we don't have to do it for ModSecurity

    //pHttpContext->GetResponse()->DisableKernelCache(
    //        IISCacheEvents::HTTPSYS_CACHEABLE::HANDLER_HTTPSYS_UNFRIENDLY);

    for(c = 0; c < pRawHttpResponse->EntityChunkCount; c++ )
    {
        pSourceDataChunk = &pRawHttpResponse->pEntityChunks[ c ];

        switch( pSourceDataChunk->DataChunkType )
        {
            case HttpDataChunkFromMemory:
                ulTotalLength += pSourceDataChunk->FromMemory.BufferLength;
                break;
            case HttpDataChunkFromFileHandle:
                pFileByteRange = &pSourceDataChunk->FromFileHandle.ByteRange;
                //
                // File chunks may contain by ranges with unspecified length 
                // (HTTP_BYTE_RANGE_TO_EOF).  In order to send parts of such a chunk, 
                // its necessary to know when the chunk is finished, and
                // we need to move to the next chunk.
                //              
                if ( pFileByteRange->Length.QuadPart == HTTP_BYTE_RANGE_TO_EOF)
                {
                    if ( GetFileType( pSourceDataChunk->FromFileHandle.FileHandle ) == 
                                    FILE_TYPE_DISK )
                    {
                        if ( !GetFileSizeEx( pSourceDataChunk->FromFileHandle.FileHandle,
                                             &lFileSize ) )
                        {
                            DWORD dwError = GetLastError();
                            hr = HRESULT_FROM_WIN32(dwError);
                            goto Finished;
                        }

                        // put the resolved file length in the chunk, replacing 
                        // HTTP_BYTE_RANGE_TO_EOF
                        pFileByteRange->Length.QuadPart = 
                              lFileSize.QuadPart - pFileByteRange->StartingOffset.QuadPart;
                    }
                    else
                    {
                        hr = HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
                        goto Finished;                        
                    }
                }  

                ulTotalLength += pFileByteRange->Length.QuadPart;
                break;
            default:
                // TBD: consider implementing HttpDataChunkFromFragmentCache, 
                // and HttpDataChunkFromFragmentCacheEx
                hr = HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
                goto Finished;                        
        }
    }

	rsc->m_pResponseBuffer = (char *)apr_palloc(rsc->m_pRequestRec->pool, ulTotalLength);

	ulTotalLength = 0;

    for(c = 0; c < pRawHttpResponse->EntityChunkCount; c++ )
    {
        pSourceDataChunk = &pRawHttpResponse->pEntityChunks[ c ];

        switch( pSourceDataChunk->DataChunkType )
        {
            case HttpDataChunkFromMemory:
				memcpy(rsc->m_pResponseBuffer + ulTotalLength, pSourceDataChunk->FromMemory.pBuffer, pSourceDataChunk->FromMemory.BufferLength);
                ulTotalLength += pSourceDataChunk->FromMemory.BufferLength;
                break;
            case HttpDataChunkFromFileHandle:
                pFileByteRange = &pSourceDataChunk->FromFileHandle.ByteRange;

				if(ReadFileChunk(pSourceDataChunk, rsc->m_pResponseBuffer + ulTotalLength) != S_OK)
				{
			        DWORD dwErr = GetLastError();

					hr = HRESULT_FROM_WIN32(dwErr);
	                goto Finished;
				}

                ulTotalLength += pFileByteRange->Length.QuadPart;
                break;
            default:
                // TBD: consider implementing HttpDataChunkFromFragmentCache, 
                // and HttpDataChunkFromFragmentCacheEx
                hr = HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
                goto Finished;                        
        }
    }

	rsc->m_pResponseLength = ulTotalLength;

	//
    // If there's no content-length set, we need to set it to avoid chunked transfer mode
    // We can only do it if there is it's the only response to be sent.
    //

    DWORD dwFlags = pResponseProvider->GetFlags();

	if (pResponseProvider->GetHeadersBeingSent() && 
         (dwFlags & HTTP_SEND_RESPONSE_FLAG_MORE_DATA) == 0 &&
         pHttpContext->GetResponse()->GetHeader(HttpHeaderContentLength) == NULL)    
    {
        CHAR szLength[21]; //Max length for a 64 bit int is 20

         ZeroMemory(szLength, sizeof(szLength));

         hr = StringCchPrintfA(
                    szLength, 
                    sizeof(szLength) / sizeof(CHAR) - 1, "%d", 
                    ulTotalLength);

        if(FAILED(hr))
        {
            goto Finished;      
        }

         hr = pHttpContext->GetResponse()->SetHeader(
                    HttpHeaderContentLength, 
                    szLength, 
                    (USHORT)strlen(szLength),
                    TRUE);

        if(FAILED(hr))
        {
            goto Finished;      
        }
    }

Finished:

	int status = modsecProcessResponse(rsc->m_pRequestRec);

	// the logic here is temporary, needs clarification
	//
	if(status != 0 && status != -1)
	{
		pHttpContext->GetResponse()->Clear();
		pHttpContext->GetResponse()->SetStatus(status, "ModSecurity Action");
		pHttpContext->SetRequestHandled();

		rsc->FinishRequest();

		LeaveCriticalSection(&m_csLock);
		
		return RQ_NOTIFICATION_FINISH_REQUEST;
	}
Exit:
	// temporary hack, in reality OnSendRequest theoretically could possibly come before OnEndRequest
	//
	if(rsc != NULL)
		rsc->FinishRequest();

	LeaveCriticalSection(&m_csLock);
		
	return RQ_NOTIFICATION_CONTINUE;
}

REQUEST_NOTIFICATION_STATUS
CMyHttpModule::OnPostEndRequest(
    IN IHttpContext * pHttpContext,
    IN IHttpEventProvider * pProvider
)
{
	REQUEST_STORED_CONTEXT *rsc = NULL;

	rsc = (REQUEST_STORED_CONTEXT *)pHttpContext->GetModuleContextContainer()->GetModuleContext(g_pModuleContext);

	// only finish request if OnSendResponse have been called already
	//
	if(rsc != NULL && rsc->m_pResponseBuffer != NULL)
	{
		EnterCriticalSection(&m_csLock);

		rsc->FinishRequest();

		LeaveCriticalSection(&m_csLock);
	}

	return RQ_NOTIFICATION_CONTINUE;
}

REQUEST_NOTIFICATION_STATUS
CMyHttpModule::OnBeginRequest(
    IN IHttpContext * pHttpContext,
    IN IHttpEventProvider * pProvider
)
{
    HRESULT                         hr                  = S_OK;
    IHttpRequest*                   pRequest            = NULL;
	MODSECURITY_STORED_CONTEXT*		pConfig = NULL;
    
    UNREFERENCED_PARAMETER ( pProvider );

	EnterCriticalSection(&m_csLock);

    if ( pHttpContext == NULL ) 
    {
        hr = E_UNEXPECTED;
        goto Finished;
    }

    pRequest = pHttpContext->GetRequest();

    if ( pRequest == NULL )
    {
        hr = E_UNEXPECTED;
        goto Finished;
    }

    hr = MODSECURITY_STORED_CONTEXT::GetConfig(pHttpContext, &pConfig );
    
    if ( FAILED( hr ) )
    {
        //hr = E_UNEXPECTED;
		hr = S_OK;
        goto Finished;
    }

	// If module is disabled, dont go any further
	//
	if( pConfig->GetIsEnabled() == false )
	{
        goto Finished;
	}

	// every 3 seconds we check for changes in config file
	//
	DWORD ctime = GetTickCount();

	if(pConfig->m_Config == NULL || (ctime - pConfig->m_dwLastCheck) > 3000)
	{
		char *path;
		USHORT pathlen;

		hr = pConfig->GlobalWideCharToMultiByte(pConfig->GetPath(), wcslen(pConfig->GetPath()), &path, &pathlen);

		if ( FAILED( hr ) )
		{
			hr = E_UNEXPECTED;
			goto Finished;
		}

		WIN32_FILE_ATTRIBUTE_DATA fdata;
		BOOL ret;

		ret = GetFileAttributesEx(path, GetFileExInfoStandard, &fdata);

		pConfig->m_dwLastCheck = ctime;

		if(pConfig->m_Config == NULL || (ret != 0 && (pConfig->m_LastChange.dwLowDateTime != fdata.ftLastWriteTime.dwLowDateTime ||
			pConfig->m_LastChange.dwHighDateTime != fdata.ftLastWriteTime.dwHighDateTime)))
		{
			pConfig->m_LastChange.dwLowDateTime = fdata.ftLastWriteTime.dwLowDateTime;
			pConfig->m_LastChange.dwHighDateTime = fdata.ftLastWriteTime.dwHighDateTime;

			pConfig->m_Config = modsecGetDefaultConfig();

			PCWSTR servpath = pHttpContext->GetApplication()->GetApplicationPhysicalPath();
			char *apppath;
			USHORT apppathlen;

			hr = pConfig->GlobalWideCharToMultiByte((WCHAR *)servpath, wcslen(servpath), &apppath, &apppathlen);

			if ( FAILED( hr ) )
			{
				delete path;
				hr = E_UNEXPECTED;
				goto Finished;
			}

			if(path[0] != 0)
			{
				const char * err = modsecProcessConfig((directory_config *)pConfig->m_Config, path, apppath);

				if(err != NULL)
				{
					WriteEventViewerLog(err, EVENTLOG_ERROR_TYPE);
					delete apppath;
					delete path;
					goto Finished;
				}

				modsecReportRemoteLoadedRules();
				if (this->status_call_already_sent == false)
				{
					this->status_call_already_sent = true;
					modsecStatusEngineCall();
				}
			}
			delete apppath;
		}
		delete path;
	}

	conn_rec *c;
	request_rec *r;

	c = modsecNewConnection();

	modsecProcessConnection(c);

	r = modsecNewRequest(c, (directory_config *)pConfig->m_Config);

	// on IIS we force input stream inspection flag, because its absence does not add any performance gain
	// it's because on IIS request body must be restored each time it was read
	//
	modsecSetConfigForIISRequestBody(r);

	REQUEST_STORED_CONTEXT *rsc = new REQUEST_STORED_CONTEXT();

	rsc->m_pConnRec = c;
	rsc->m_pRequestRec = r;
	rsc->m_pHttpContext = pHttpContext;
	rsc->m_pProvider = pProvider;

	pHttpContext->GetModuleContextContainer()->SetModuleContext(rsc, g_pModuleContext);

	StoreIISContext(r, rsc);

	HTTP_REQUEST *req = pRequest->GetRawHttpRequest();

	r->hostname = ConvertUTF16ToUTF8(req->CookedUrl.pHost, req->CookedUrl.HostLength / sizeof(WCHAR), r->pool);
	r->path_info = ConvertUTF16ToUTF8(req->CookedUrl.pAbsPath, req->CookedUrl.AbsPathLength / sizeof(WCHAR), r->pool);

	if(r->hostname == NULL)
	{
		if(req->Headers.KnownHeaders[HttpHeaderHost].pRawValue != NULL)
			r->hostname = ZeroTerminate(req->Headers.KnownHeaders[HttpHeaderHost].pRawValue,
										req->Headers.KnownHeaders[HttpHeaderHost].RawValueLength, r->pool);
	}

	int port = 0;
	char *port_str = NULL;

	if(r->hostname != NULL)
	{
		int k = 0;
		char *ptr = (char *)r->hostname;

		while(*ptr != 0 && *ptr != ':')
			ptr++;

		if(*ptr == ':')
		{
			*ptr = 0;
			port_str = ptr + 1;
			port = atoi(port_str);
		}
	}

	if(req->CookedUrl.pQueryString != NULL && req->CookedUrl.QueryStringLength > 0)
		r->args = ConvertUTF16ToUTF8(req->CookedUrl.pQueryString + 1, (req->CookedUrl.QueryStringLength / sizeof(WCHAR)) - 1, r->pool);

#define _TRANSHEADER(id,str) if(req->Headers.KnownHeaders[id].pRawValue != NULL) \
	{\
		apr_table_setn(r->headers_in, str, \
			ZeroTerminate(req->Headers.KnownHeaders[id].pRawValue, req->Headers.KnownHeaders[id].RawValueLength, r->pool)); \
	}

    _TRANSHEADER(HttpHeaderCacheControl, "Cache-Control");
    _TRANSHEADER(HttpHeaderConnection, "Connection");
    _TRANSHEADER(HttpHeaderDate, "Date");
    _TRANSHEADER(HttpHeaderKeepAlive, "Keep-Alive");             
    _TRANSHEADER(HttpHeaderPragma, "Pragma");                
    _TRANSHEADER(HttpHeaderTrailer, "Trailer");               
    _TRANSHEADER(HttpHeaderTransferEncoding, "Transfer-Encoding");      
    _TRANSHEADER(HttpHeaderUpgrade, "Upgrade");               
    _TRANSHEADER(HttpHeaderVia, "Via");                   
    _TRANSHEADER(HttpHeaderWarning, "Warning");               
    _TRANSHEADER(HttpHeaderAllow, "Allow");                 
    _TRANSHEADER(HttpHeaderContentLength, "Content-Length");         
    _TRANSHEADER(HttpHeaderContentType, "Content-Type");           
    _TRANSHEADER(HttpHeaderContentEncoding, "Content-Encoding");       
    _TRANSHEADER(HttpHeaderContentLanguage, "Content-Language");       
    _TRANSHEADER(HttpHeaderContentLocation, "Content-Location");       
    _TRANSHEADER(HttpHeaderContentMd5, "Content-Md5");            
    _TRANSHEADER(HttpHeaderContentRange, "Content-Range");          
    _TRANSHEADER(HttpHeaderExpires, "Expires");               
    _TRANSHEADER(HttpHeaderLastModified, "Last-Modified");          
    _TRANSHEADER(HttpHeaderAccept, "Accept");                
    _TRANSHEADER(HttpHeaderAcceptCharset, "Accept-Charset");        
    _TRANSHEADER(HttpHeaderAcceptEncoding, "Accept-Encoding");        
    _TRANSHEADER(HttpHeaderAcceptLanguage, "Accept-Language");        
    _TRANSHEADER(HttpHeaderAuthorization, "Authorization");         
    _TRANSHEADER(HttpHeaderCookie, "Cookie");                
    _TRANSHEADER(HttpHeaderExpect, "Expect");                
    _TRANSHEADER(HttpHeaderFrom, "From");                  
    _TRANSHEADER(HttpHeaderHost, "Host");                  
    _TRANSHEADER(HttpHeaderIfMatch, "If-Match");               
    _TRANSHEADER(HttpHeaderIfModifiedSince, "If-Modified-Since");       
    _TRANSHEADER(HttpHeaderIfNoneMatch, "If-None-Match");           
    _TRANSHEADER(HttpHeaderIfRange, "If-Range");               
    _TRANSHEADER(HttpHeaderIfUnmodifiedSince, "If-Unmodified-Since");     
    _TRANSHEADER(HttpHeaderMaxForwards, "Max-Forwards");           
    _TRANSHEADER(HttpHeaderProxyAuthorization, "Proxy-Authorization");    
    _TRANSHEADER(HttpHeaderReferer, "Referer");               
    _TRANSHEADER(HttpHeaderRange, "Range");                 
    _TRANSHEADER(HttpHeaderTe, "TE");                    
    _TRANSHEADER(HttpHeaderTranslate, "Translate");             
    _TRANSHEADER(HttpHeaderUserAgent, "User-Agent");

#undef _TRANSHEADER

	for(int i = 0; i < req->Headers.UnknownHeaderCount; i++)
	{
		apr_table_setn(r->headers_in, 
			ZeroTerminate(req->Headers.pUnknownHeaders[i].pName, req->Headers.pUnknownHeaders[i].NameLength, r->pool), 
			ZeroTerminate(req->Headers.pUnknownHeaders[i].pRawValue, req->Headers.pUnknownHeaders[i].RawValueLength, r->pool));
	}

	r->content_encoding = apr_table_get(r->headers_in, "Content-Encoding");
	r->content_type = apr_table_get(r->headers_in, "Content-Type");

	const char *lng = apr_table_get(r->headers_in, "Content-Languages");

	if(lng != NULL)
	{
		r->content_languages = apr_array_make(r->pool, 1, sizeof(const char *));

		*(const char **)apr_array_push(r->content_languages) = lng;
	}

	switch(req->Verb)
	{
	case HttpVerbUnparsed:
	case HttpVerbUnknown:
	case HttpVerbInvalid:
    case HttpVerbTRACK:  // used by Microsoft Cluster Server for a non-logged trace
    case HttpVerbSEARCH:
	default:
		r->method = "INVALID";
		r->method_number = M_INVALID;
		break;
	case HttpVerbOPTIONS:
		r->method = "OPTIONS";
		r->method_number = M_OPTIONS;
		break;
	case HttpVerbGET:
	case HttpVerbHEAD:
		r->method = "GET";
		r->method_number = M_GET;
		break;
	case HttpVerbPOST:
		r->method = "POST";
		r->method_number = M_POST;
		break;
    case HttpVerbPUT:
		r->method = "PUT";
		r->method_number = M_PUT;
		break;
    case HttpVerbDELETE:
		r->method = "DELETE";
		r->method_number = M_DELETE;
		break;
    case HttpVerbTRACE:
		r->method = "TRACE";
		r->method_number = M_TRACE;
		break;
    case HttpVerbCONNECT:
		r->method = "CONNECT";
		r->method_number = M_CONNECT;
		break;
    case HttpVerbMOVE:
		r->method = "MOVE";
		r->method_number = M_MOVE;
		break;
    case HttpVerbCOPY:
		r->method = "COPY";
		r->method_number = M_COPY;
		break;
    case HttpVerbPROPFIND:
		r->method = "PROPFIND";
		r->method_number = M_PROPFIND;
		break;
    case HttpVerbPROPPATCH:
		r->method = "PROPPATCH";
		r->method_number = M_PROPPATCH;
		break;
    case HttpVerbMKCOL:
		r->method = "MKCOL";
		r->method_number = M_MKCOL;
		break;
    case HttpVerbLOCK:
		r->method = "LOCK";
		r->method_number = M_LOCK;
		break;
    case HttpVerbUNLOCK:
		r->method = "UNLOCK";
		r->method_number = M_UNLOCK;
		break;
	}

	if(HTTP_EQUAL_VERSION(req->Version, 0, 9))
		r->protocol = "HTTP/0.9";
	else if(HTTP_EQUAL_VERSION(req->Version, 1, 0))
		r->protocol = "HTTP/1.0";
	else
		r->protocol = "HTTP/1.1";

	r->request_time = apr_time_now();

	r->parsed_uri.scheme = "http";
	r->parsed_uri.path = r->path_info;
	r->parsed_uri.hostname = (char *)r->hostname;
	r->parsed_uri.is_initialized = 1;
	r->parsed_uri.port = port;
	r->parsed_uri.port_str = port_str;
	r->parsed_uri.query = r->args;
	r->parsed_uri.dns_looked_up = 0;
	r->parsed_uri.dns_resolved = 0;
	r->parsed_uri.password = NULL;
	r->parsed_uri.user = NULL;
	r->parsed_uri.fragment = NULL;

	r->unparsed_uri = ZeroTerminate(req->pRawUrl, req->RawUrlLength, r->pool);
	r->uri = r->unparsed_uri;

	r->the_request = (char *)apr_palloc(r->pool, strlen(r->method) + 1 + req->RawUrlLength + 1 + strlen(r->protocol) + 1);

	strcpy(r->the_request, r->method);
	strcat(r->the_request, " ");
	strcat(r->the_request, r->uri);
	strcat(r->the_request, " ");
	strcat(r->the_request, r->protocol);

	HTTP_REQUEST_ID httpRequestID;
	char *pszValue = (char *)apr_palloc(r->pool, 24);

	httpRequestID = pRequest->GetRawHttpRequest()->RequestId;

	_ui64toa(httpRequestID, pszValue, 10);

	apr_table_setn(r->subprocess_env, "UNIQUE_ID", pszValue);

	PSOCKADDR pAddr = pRequest->GetRemoteAddress();

#if AP_SERVER_MAJORVERSION_NUMBER > 1 && AP_SERVER_MINORVERSION_NUMBER < 3
    c->remote_addr = CopySockAddr(r->pool, pAddr);
    c->remote_ip = GetIpAddr(r->pool, pAddr);
#else
    c->client_addr = CopySockAddr(r->pool, pAddr);
	c->client_ip = GetIpAddr(r->pool, pAddr);
#endif
	c->remote_host = NULL;

	int status = modsecProcessRequest(r);

	if(status != DECLINED)
	{
		pHttpContext->GetResponse()->SetStatus(status, "ModSecurity Action");
		pHttpContext->SetRequestHandled();

		hr = E_FAIL;
		goto Finished;
	}

Finished:
	LeaveCriticalSection(&m_csLock);

    if ( FAILED( hr )  )
    {
        return RQ_NOTIFICATION_FINISH_REQUEST;
    }
	return RQ_NOTIFICATION_CONTINUE;
}

apr_status_t ReadBodyCallback(request_rec *r, char *buf, unsigned int length, unsigned int *readcnt, int *is_eos)
{
	REQUEST_STORED_CONTEXT *rsc = RetrieveIISContext(r);

	*readcnt = 0;

	if(rsc == NULL)
	{
		*is_eos = 1;
		return APR_SUCCESS;
	}

	IHttpContext *pHttpContext = rsc->m_pHttpContext;
	IHttpRequest *pRequest = pHttpContext->GetRequest();

	if(pRequest->GetRemainingEntityBytes() == 0)
	{
		*is_eos = 1;
		return APR_SUCCESS;
	}

	HRESULT hr = pRequest->ReadEntityBody(buf, length, false, (DWORD *)readcnt, NULL);

	if (FAILED(hr))
    {
        // End of data is okay.
        if (ERROR_HANDLE_EOF != (hr  & 0x0000FFFF))
        {
            // Set the error status.
            rsc->m_pProvider->SetErrorStatus( hr );
        }

		*is_eos = 1;
    }

	return APR_SUCCESS;
}

apr_status_t WriteBodyCallback(request_rec *r, char *buf, unsigned int length)
{
	REQUEST_STORED_CONTEXT *rsc = RetrieveIISContext(r);

	if(rsc == NULL || rsc->m_pRequestRec == NULL)
		return APR_SUCCESS;

	IHttpContext *pHttpContext = rsc->m_pHttpContext;
	IHttpRequest *pHttpRequest = pHttpContext->GetRequest();

    CHAR szLength[21]; //Max length for a 64 bit int is 20

    ZeroMemory(szLength, sizeof(szLength));

    HRESULT hr = StringCchPrintfA(
            szLength, 
            sizeof(szLength) / sizeof(CHAR) - 1, "%d", 
            length);

    if(FAILED(hr))
    {
		// not possible
    }

    hr = pHttpRequest->SetHeader(
            HttpHeaderContentLength, 
            szLength, 
            (USHORT)strlen(szLength),
            TRUE);

    if(FAILED(hr))
    {
		// possible, but there's nothing we can do
    }

	// since we clean the APR pool at the end of OnSendRequest, we must get IIS-managed memory chunk
	//
	void *reqbuf = pHttpContext->AllocateRequestMemory(length);

	memcpy(reqbuf, buf, length);

	pHttpRequest->InsertEntityBody(reqbuf, length);

	return APR_SUCCESS;
}

apr_status_t ReadResponseCallback(request_rec *r, char *buf, unsigned int length, unsigned int *readcnt, int *is_eos)
{
	REQUEST_STORED_CONTEXT *rsc = RetrieveIISContext(r);

	*readcnt = 0;

	if(rsc == NULL || rsc->m_pResponseBuffer == NULL)
	{
		*is_eos = 1;
		return APR_SUCCESS;
	}

	unsigned int size = length;

	if(size > rsc->m_pResponseLength - rsc->m_pResponsePosition)
		size = rsc->m_pResponseLength - rsc->m_pResponsePosition;

	memcpy(buf, rsc->m_pResponseBuffer + rsc->m_pResponsePosition, size);

	*readcnt = size;
	rsc->m_pResponsePosition += size;

	if(rsc->m_pResponsePosition >= rsc->m_pResponseLength)
		*is_eos = 1;

	return APR_SUCCESS;
}

apr_status_t WriteResponseCallback(request_rec *r, char *buf, unsigned int length)
{
	REQUEST_STORED_CONTEXT *rsc = RetrieveIISContext(r);

	if(rsc == NULL || rsc->m_pRequestRec == NULL || rsc->m_pResponseBuffer == NULL)
		return APR_SUCCESS;

	IHttpContext *pHttpContext = rsc->m_pHttpContext;
	IHttpResponse *pHttpResponse = pHttpContext->GetResponse();
	HTTP_RESPONSE *pRawHttpResponse = pHttpResponse->GetRawHttpResponse();
	HTTP_DATA_CHUNK *pDataChunk = (HTTP_DATA_CHUNK *)apr_palloc(rsc->m_pRequestRec->pool, sizeof(HTTP_DATA_CHUNK));

	pRawHttpResponse->EntityChunkCount = 0;

	// since we clean the APR pool at the end of OnSendRequest, we must get IIS-managed memory chunk
	//
	void *reqbuf = pHttpContext->AllocateRequestMemory(length);

	memcpy(reqbuf, buf, length);

	pDataChunk->DataChunkType = HttpDataChunkFromMemory;
	pDataChunk->FromMemory.pBuffer = reqbuf;
	pDataChunk->FromMemory.BufferLength = length;

    CHAR szLength[21]; //Max length for a 64 bit int is 20

    ZeroMemory(szLength, sizeof(szLength));

    HRESULT hr = StringCchPrintfA(
            szLength, 
            sizeof(szLength) / sizeof(CHAR) - 1, "%d", 
            length);

    if(FAILED(hr))
    {
		// not possible
    }

    hr = pHttpResponse->SetHeader(
            HttpHeaderContentLength, 
            szLength, 
            (USHORT)strlen(szLength),
            TRUE);

    if(FAILED(hr))
    {
		// possible, but there's nothing we can do
    }

	pHttpResponse->WriteEntityChunkByReference(pDataChunk);

	return APR_SUCCESS;
}


CMyHttpModule::CMyHttpModule()
{
    // Open a handle to the Event Viewer.
    m_hEventLog = RegisterEventSource( NULL, "ModSecurity" );

    SYSTEM_INFO         sysInfo;

    GetSystemInfo(&sysInfo);
    m_dwPageSize = sysInfo.dwPageSize;

    this->status_call_already_sent = false;

	InitializeCriticalSection(&m_csLock);

	modsecSetLogHook(this, Log);

	modsecSetReadBody(ReadBodyCallback);
	modsecSetReadResponse(ReadResponseCallback);
	modsecSetWriteBody(WriteBodyCallback);
	modsecSetWriteResponse(WriteResponseCallback);

	server_rec *s = modsecInit();
	char *compname = (char *)malloc(128);
	DWORD size = 128;

	GetComputerName(compname, &size);

	s->server_hostname = compname;

	modsecStartConfig();

	modsecFinalizeConfig();

	modsecInitProcess();
}

CMyHttpModule::~CMyHttpModule()
{
	// ModSecurity registers APR pool cleanups, which interfere with APR pool tear down process
	// this causes crashes and since we are exiting the process here, so this is a temporary solution
	//
	//modsecTerminate();

	//WriteEventViewerLog("Module deleted.");

	// Test whether the handle for the Event Viewer is open.
    if (NULL != m_hEventLog)
    {
        // Close the handle to the Event Viewer.
        DeregisterEventSource( m_hEventLog );
        m_hEventLog = NULL;

		DeleteCriticalSection(&m_csLock);
    }
}

void CMyHttpModule::Dispose()
{
}

BOOL CMyHttpModule::WriteEventViewerLog(LPCSTR szNotification, WORD category)
{
    // Test whether the handle for the Event Viewer is open.
    if (NULL != m_hEventLog)
    {
        // Write any strings to the Event Viewer and return.
        return ReportEvent(
            m_hEventLog,
            category, 0, 0x1,
            NULL, 1, 0, &szNotification, NULL );
    }
    return FALSE;
}
