/*++ Copyright (c) 1995-1996 Microsoft Corporation Module Name: main.c Abstract: Implements a simple lottery number generator for illustrating the working of ISAPI (Internet Server API). Project: Internet Server API Extensions (Samples) History: Created 06-Feb-1996 --*/ /************************************************************ * Include Headers ************************************************************/ # include # include # include # include # include "httpext.h" /************************************************************ * Globals for this module ************************************************************/ /* * g_dwLotteryNumberSequence * * This global variable maintains the current state about the * the lottery number generated. * The lottery number is generated using a combination * of the sequence number and a random number generated on the fly. * */ DWORD g_dwLotteryNumberSequence = 0; /* * Critical section to protect the global counter. * */ CRITICAL_SECTION g_csGlobal; /* * Prototype of the lottery number generator function */ VOID GenerateLotteryNumber( LPDWORD pLotNum1, LPDWORD pLotNum2); /************************************************************ * Functions ************************************************************/ BOOL WINAPI DllLibMain( 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: { time_t pTime; // // Initialize various data and modules. // InitializeCriticalSection(&g_csGlobal); srand(time(&pTime)); g_dwLotteryNumberSequence = rand(); 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. // if ( lpvContext != NULL) { DeleteCriticalSection(&g_csGlobal); } break; } /* case DLL_PROCESS_DETACH */ default: break; } /* switch */ return ( fReturn); } /* DllLibMain() */ BOOL WINAPI GetExtensionVersion( HSE_VERSION_INFO *pVer ) /*++ Routine Description: This is the first function that is called when this ISAPI DLL is loaded. We should fill in the version information in the structure passed in. Arguments: pVer - pointer to Server Extension Version Information structure. Returns: TRUE for success and FALSE for failure. On success the valid version information is stored in *pVer. --*/ { // // Store the version number and descriptor string // pVer->dwExtensionVersion = MAKELONG( HSE_VERSION_MINOR, HSE_VERSION_MAJOR ); lstrcpyn( pVer->lpszExtensionDesc, "Simple Lottery Number Generator", HSE_MAX_EXT_DLL_NAME_LEN); return TRUE; } /* GetExtensionVersion() */ DWORD WINAPI HttpExtensionProc( EXTENSION_CONTROL_BLOCK * pecb ) /*++ Routine Description: This is the main function that is called for this ISAPI Extension. This function processes the request and sends out appropriate response. Arguments: pecb - pointer to EXTENSION_CONTROL_BLOCK, which contains most of the required variables for the extension called. In addition, it contains the various callbacks as appropriate. Returns: HSE_STATUS code indicating the succes/failure of this call. --*/ { BOOL fReturn; char rgBuff[2048]; // // Generate Dynamic header for the message to send back. // Note the HTTP header block is terminated by a blank '\r\n' pair, // followed by the document body // wsprintf( rgBuff, "Content-Type: text/html\r\n" "\r\n" /* <--- header is terminated */ ); fReturn = pecb->ServerSupportFunction( pecb->ConnID, /* ConnID */ HSE_REQ_SEND_RESPONSE_HEADER, /* dwHSERRequest */ "200 OK", /* lpvBuffer */ NULL, /* lpdwSize. NULL=> send string */ (LPDWORD ) rgBuff); /* header contents */ if ( fReturn ) { CHAR rgchLuckyNumber[40]; DWORD dwLotNum1, dwLotNum2; DWORD cb; CHAR rgchClientHost[200] = "LT"; DWORD cbClientHost = 200; if ( !pecb->GetServerVariable(pecb->ConnID, "REMOTE_HOST", rgchClientHost, &cbClientHost) ) { // No host name is available. // Make up one strcpy(rgchClientHost, "RH"); } else { // terminate with just two characters rgchClientHost[2] = '\0'; } // // We are successful in sending the header. // // Generate a lottery number, generate the contents of body and // send the body to client. // GenerateLotteryNumber( &dwLotNum1, &dwLotNum2); // Lottery Number format is: Number-2letters-Number. wsprintf( rgchLuckyNumber, "%03d-%s-%05d", dwLotNum1, rgchClientHost, dwLotNum2); // // Body of the message sent back. // cb = wsprintf( rgBuff, "Lucky Number\n" "

Lucky Corner

" "

Your lottery number is: " " %s

\n" "

", rgchLuckyNumber); fReturn = pecb->WriteClient(pecb->ConnID, /* ConnID */ (LPVOID ) rgBuff, /* message */ &cb, /* lpdwBytes */ 0 ); /* reserved */ } return ( fReturn ? HSE_STATUS_SUCCESS : HSE_STATUS_ERROR); } /* HttpExtensionProc() */ VOID GenerateLotteryNumber( LPDWORD pLotNum1, LPDWORD pLotNum2) { DWORD dwLotteryNum; DWORD dwModulo; // // Obtain the current lottery number an increment the counter // To keep this multi-thread safe use critical section around it // EnterCriticalSection( &g_csGlobal); dwLotteryNum = g_dwLotteryNumberSequence++; LeaveCriticalSection( &g_csGlobal); // obtain a non-zero modulo value do { dwModulo = rand(); } while ( dwModulo == 0); // solit the lottery number into two parts. *pLotNum1 = (dwLotteryNum / dwModulo); *pLotNum2 = (dwLotteryNum % dwModulo); return; } // GenerateLotteryNumber() /**************************** End of File *************************/