FWRITE.C
/*++
Copyright (c) 1995-1997 Microsoft Corporation
Module Name:
fwrite.c
Abstract:
This module demonstrates a simple file transfer using ISAPI application
using the WriteClient() callback.
Revision History:
--*/
# define WIN32_LEAN_AND_MEAN
# include <windows.h>
# include <stdio.h>
# include "httpext.h"
# include "openf.h"
DWORD
SendHeaderToClient( IN EXTENSION_CONTROL_BLOCK * pecb, IN LPCSTR pszErrorMsg);
DWORD
SendFileToClient( IN EXTENSION_CONTROL_BLOCK * pecb, IN LPCSTR pszFile);
DWORD
SendFileOver( IN EXTENSION_CONTROL_BLOCK * pecb, IN HANDLE hFile);
BOOL WINAPI
DllMain(
IN HINSTANCE hinstDll,
IN DWORD fdwReason,
IN LPVOID lpvContext OPTIONAL)
/*++
Routine Description:
This function DllLibMain() is the main initialization function for
this DLL. It initializes local variables and prepares it to be invoked
subsequently.
Arguments:
hinstDll Instance Handle of the DLL
fdwReason Reason why NT called this DLL
lpvReserved Reserved parameter for future use.
Return Value:
Returns TRUE is successful; otherwise FALSE is returned.
--*/
{
BOOL fReturn = TRUE;
switch (fdwReason ) {
case DLL_PROCESS_ATTACH:
{
OutputDebugString( " Initializing the global data in fwrite.dll\n");
//
// Initialize various data and modules.
//
fReturn = (InitFileHandleCache() == NO_ERROR);
break;
} /* case DLL_PROCESS_ATTACH */
case DLL_PROCESS_DETACH:
{
//
// Only cleanup when we are called because of a FreeLibrary().
// i.e., when lpvContext == NULL
// If we are called because of a process termination,
// dont free anything. System will free resources and memory for us.
//
CleanupFileHandleCache();
break;
} /* case DLL_PROCESS_DETACH */
default:
break;
} /* switch */
return ( fReturn);
} /* DllLibMain() */
DWORD WINAPI
HttpExtensionProc(
IN EXTENSION_CONTROL_BLOCK * pecb
)
{
DWORD hseStatus;
if ( pecb->lpszQueryString == NULL) {
hseStatus = SendHeaderToClient( pecb, "File Not Found");
} else {
hseStatus = SendFileToClient( pecb, pecb->lpszQueryString);
}
return ( hseStatus);
} // HttpExtensionProc()
BOOL WINAPI
GetExtensionVersion(
HSE_VERSION_INFO * pver
)
{
pver->dwExtensionVersion = MAKELONG( 1, 0 );
strcpy( pver->lpszExtensionDesc,
"File Transfer using WriteClient" );
return TRUE;
}
BOOL WINAPI
TerminateExtension(
/*IN */ DWORD dwFlags
)
/*++
This function is called when IIS decides to stop and unload the
ISAPI DLL. We can do any custom cleanup for the module inside this function
--*/
{
//
// Nothing specific do here for cleanup
// Cleanup is done in the dll process detach in DllLibMain()
//
return ( TRUE);
}
DWORD
SendHeaderToClient( IN EXTENSION_CONTROL_BLOCK * pecb, IN LPCSTR pszErrorMsg)
{
HSE_SEND_HEADER_EX_INFOSendHeaderExInfo;
char szStatus[] = "200 OK";
char szHeader[1024];
//
// Note the HTTP header block is terminated by a blank '\r\n' pair,
// followed by the document body
//
wsprintf( szHeader,
"Content-Type: text/html\r\n"
"\r\n" // marks the end of header block
"<head><title>Simple File Transfer (Synchronous Write)"
"</title></head>\n"
"<body><h1>%s</h1>\n"
,
pszErrorMsg );
//
// Populate SendHeaderExInfo struct
//
SendHeaderExInfo.pszStatus = szStatus;
SendHeaderExInfo.pszHeader = szHeader;
SendHeaderExInfo.cchStatus = lstrlen( szStatus);
SendHeaderExInfo.cchHeader = lstrlen( szHeader);
SendHeaderExInfo.fKeepConn = FALSE;
//
// Send header - use the EX Version to send the header blob
//
if ( !pecb->ServerSupportFunction(
pecb->ConnID
, HSE_REQ_SEND_RESPONSE_HEADER_EX
, &SendHeaderExInfo
, NULL
, NULL
) ) {
return HSE_STATUS_ERROR;
}
return ( HSE_STATUS_SUCCESS);
} // SendHeaderToClient()
DWORD
SendFileToClient( IN EXTENSION_CONTROL_BLOCK * pecb, IN LPCSTR pszFile)
{
CHAR pchBuffer[1024];
HANDLE hFile;
DWORD hseStatus = HSE_STATUS_SUCCESS;
hFile = FcOpenFile( pecb, pszFile);
if ( hFile == INVALID_HANDLE_VALUE) {
wsprintfA( pchBuffer,
"OpenFailed: Error (%d) while opening the file %s.\n",
GetLastError(), pszFile);
hseStatus = SendHeaderToClient( pecb, pchBuffer);
} else {
wsprintfA( pchBuffer, " Transferred file contains...");
hseStatus = SendHeaderToClient( pecb, pchBuffer);
if ( hseStatus == HSE_STATUS_SUCCESS) {
hseStatus = SendFileOver( pecb, hFile);
if ( hseStatus != HSE_STATUS_PENDING) {
if ( hseStatus != HSE_STATUS_SUCCESS) {
//
// Error in transmitting the file. Send error message.
//
wsprintfA( pchBuffer,
"Send Failed: Error (%d) for file %s.\n",
GetLastError(), pszFile);
SendHeaderToClient( pecb, pchBuffer);
}
}
if ( hseStatus != HSE_STATUS_PENDING) {
//
// assume that the data is transmitted.
//
// close file handle
FcCloseFile( hFile);
}
}
}
return (hseStatus);
} // SendFileToClient()
# define MAX_BUFFER_SIZE (4096)
DWORD
SendFileOver( IN EXTENSION_CONTROL_BLOCK * pecb, IN HANDLE hFile)
{
CHAR pchBuffer[MAX_BUFFER_SIZE];
DWORD dwBytesInFile = GetFileSize(hFile, NULL);
DWORD nRead = 0;
DWORD hseStatus = HSE_STATUS_SUCCESS;
OVERLAPPED ov;
DWORD err;
//
// Send the whole file.
// Loop thru reading the file and transmitting it to client
//
memset(&ov, 0, sizeof(OVERLAPPED));
ov.OffsetHigh = 0;
ov.Offset = 0;
ov.hEvent = CreateEvent(NULL, TRUE, FALSE, "OVERLAPPED::hEvent");
if ( ov.hEvent == NULL) {
return (HSE_STATUS_ERROR);
}
do {
nRead = 0;
// read data from the file
if (!FcReadFromFile( hFile, pchBuffer, MAX_BUFFER_SIZE, &nRead,
&ov)
) {
hseStatus = HSE_STATUS_ERROR;
break;
}
// write data to client
if ( !pecb->WriteClient( pecb->ConnID,
pchBuffer, &nRead,
0)
) {
hseStatus = HSE_STATUS_ERROR;
break;
}
} while (TRUE);
if ( ov.hEvent != NULL) {
err = GetLastError();
CloseHandle( ov.hEvent);
ov.hEvent = NULL;
SetLastError( err);
}
return (hseStatus);
} // SendFileOver()