Thread: Strange errors.

The Windows telnet client sends data as type you, not when you press the enter key. This means your application will probably not receive a complete command in one read. You'll need to buffer the incoming data until you know you have received a complete command before you determine which command it is.

To see what is happening, open an output file stream, and write all your incoming data to it, something like this (this is the contents of said debug file):

From read 2 bytes:>qu<
From read 3 bytes:>it\n<

(\n will actually be a 0xa or 0xd or both)

OK, i have modified my code as follows, and now after when I call readfile (right after "perror("5 1/2");" the application stops responding. Is this some kind of default behavior for readfile under certain circumstances? My win32.hlp file mentions overlapped IO. Do I need to use this? Now I'm even more confused.
Also as a side question, why would the windows telnet send each character, and the linux version buffer? It seems as if it wouldn't make any sense to buffer the responses like linux seems to be doing. For instance what if you were trying to use some sort of menu where 'q' meant quit, would you have to type q-->enter ?

Code:

#include <winsock.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>

    HANDLE rPipe, rInput;
    HANDLE wPipe, wInput;
    HANDLE wError;
    SECURITY_ATTRIBUTES pipesec;
    STARTUPINFO startInfo;
    PROCESS_INFORMATION pinfo;
    char buffer[1023];
    //char inbuffer[256];
    char tmpbuffer[256];
    void DiplayError();

    BOOL bRet;
    //HANDLE hThread; 
    //HANDLE hThread2;
    //DWORD dwThreadID2;
    //DWORD dwThreadID;

    DWORD bytesRead;
    DWORD bytesWrote;
    WSADATA wsda;			// Structure to store information returned from
					// WSAStartup

   char szRepMessage[80];               // Store the reply message
   int iMessageLen;

   char szInBuffer[1023];
   int iBufferLen;

   int iPort, iAddrLen;
   
   SOCKET sListen, sClient;                    // Our TCP socket handle
   SOCKADDR_IN addr,            // The local interface
               remote_addr;     // The address of the connecting host   
    
int main(int argc, int **argv)
{
int ret;


startup();
   // Receive data
for (;;) { 
sendconsole();
writeconsole();
}
   printf("Closing client socket & Pipe Handles...");
   closesocket(sClient);
   CloseHandle(rInput);
   CloseHandle(wInput);
   CloseHandle(wPipe);  
   CloseHandle(rPipe);
   printf("OK\n");

   return 0;
}

int writeconsole(){
int ret;

memset(szInBuffer, 0, sizeof(szInBuffer));
ret = recv(sClient, tmpbuffer, sizeof(tmpbuffer), 0);
   if(ret == SOCKET_ERROR)
   {
      DisplayError("Recieve Error!");
      strcpy(szInBuffer, "quit");
      checkcommandline();
   }
    while (!strstr(tmpbuffer, "\n")){
    strcat (szInBuffer, tmpbuffer);
    printf("szInBuffer: %s\n", szInBuffer);
    ret = recv(sClient, tmpbuffer, sizeof(tmpbuffer), 0);
   if(ret == SOCKET_ERROR)
   {
      DisplayError("Recieve Error!");
      strcpy(szInBuffer, "quit");
      checkcommandline();
   }}
   perror("1");
iBufferLen = strlen (szInBuffer);		// recv() returns the number of bytes read
perror("2");
strcat (szInBuffer, "\n\r\0");
perror("3");
checkcommandline();
perror("4");
WriteFile(wInput, szInBuffer, iBufferLen, &bytesWrote, 0); 
  }


int sendconsole(){
int ret;

    for(;;)
        {    DWORD dwRead; BOOL bRet;
        perror("5");
        memset(buffer, 0, sizeof(buffer));
        perror("5 1/2");
        bRet = ReadFile(rPipe, buffer, sizeof(buffer), &bytesRead,NULL);
        perror("6");
        if(bRet==FALSE) { // pipe closed
        perror("7");
        DisplayError ("ReadFile"); 
        break;
        }
        if (buffer == NULL){
        perror("8");
        DisplayError ("buffer == NULL!");  }
        ret = send(sClient, buffer, strlen(buffer), 0);
        perror("9");
               if(ret == SOCKET_ERROR) {
               DisplayError ("Send Error!");
               strcpy(szInBuffer, "quit");
               checkcommandline();
               }
        break;  
        }
    }
    
int DisplayError(char *pszAPI)
   {
       LPVOID lpvMessageBuffer;
       CHAR szPrintBuffer[512];
       DWORD nCharsWritten;

       FormatMessage(
                FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM,
                NULL, GetLastError(),
                MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                (LPTSTR)&lpvMessageBuffer, 0, NULL);

       wsprintf(szPrintBuffer,
         "ERROR: API    = %s.\n   error code = %d.\n   message    = %s.\n",
                pszAPI, GetLastError(), (char *)lpvMessageBuffer);

       WriteConsole(GetStdHandle(STD_OUTPUT_HANDLE),szPrintBuffer,
                     lstrlen(szPrintBuffer),&nCharsWritten,NULL);

       LocalFree(lpvMessageBuffer);
       //ExitProcess(GetLastError());
   }
   
int checkcommandline()
    {
if (strstr (szInBuffer, "quit")){
    printf("Closing client socket & Pipe Handles...");
    memset(szInBuffer, 0, sizeof(szInBuffer));
    memset(buffer, 0, sizeof(buffer));
    closesocket(sClient);
    CloseHandle(rInput);
    CloseHandle(wInput);
    CloseHandle(wPipe);  
    CloseHandle(rPipe);
    printf("OK\n");
    startup();}

}

int startup()
    {
    int ret;
   // Get the remote port
    pipesec.nLength = sizeof(SECURITY_ATTRIBUTES);
    pipesec.lpSecurityDescriptor = NULL;
    pipesec.bInheritHandle = TRUE;
    if (!CreatePipe(&rPipe, &wPipe, &pipesec, 0)) 
        MessageBox(NULL,"Error Creating Pipe!",NULL,0);
    if (!CreatePipe(&rInput,&wInput,&pipesec,0))
        MessageBox(NULL,"Error Creating Pipe!",NULL,0);
    startInfo.cb = sizeof(STARTUPINFO);
    GetStartupInfo(&startInfo);
    startInfo.hStdOutput = wPipe;
    startInfo.hStdInput = rInput;
    startInfo.hStdError = wPipe;
    startInfo.dwFlags =  STARTF_USESHOWWINDOW+ STARTF_USESTDHANDLES; 
    startInfo.wShowWindow = SW_HIDE;
    if (!CreateProcess(NULL, "cmd.exe", NULL, NULL, TRUE, 0, NULL, NULL, &startInfo, &pinfo))
        MessageBox(NULL,"Error Starting CMD.EXE!",NULL,0);
        
        
   iPort = atoi((char *) &"12374");

   // Load version 1.1 of Winsock

   WSAStartup(MAKEWORD(1,1), &wsda);

   // Create a TCP socket
   printf("Creating socket...");
   sListen = socket(AF_INET, SOCK_STREAM, IPPROTO_IP);

   // Error?
   if(sListen == SOCKET_ERROR)
   {
      printf("Error\nCall to socket(AF_INET, SOCK_STREAM, IPPROTO_IP); failed with:\n%d\n", WSAGetLastError());
      exit(1);
   }

   printf("OK\n");

   printf("Binding socket to port %d...", iPort);

   addr.sin_family = AF_INET;
   addr.sin_port = htons(iPort);
   addr.sin_addr.s_addr = htonl(INADDR_ANY);          // Listen on any interface

   ret = bind(sListen, (struct sockaddr *) &addr, sizeof(addr));

   // Error?
   if(ret == SOCKET_ERROR)
   {
      printf("Error\nCall to bind(sListen, (struct sockaddr *) &addr, sizeof(addr)); failed with:\n%d\n", WSAGetLastError());
      exit(1);
   }

   printf("OK\n");

   printf("Putting socket into listening mode...");

   ret = listen(sListen, 10);        // Backlog 10

   // Error?
   if(ret == SOCKET_ERROR)
   {
      printf("Error\nCall to listen(sListen, 10); failed with:\n%d\n", WSAGetLastError());
      exit(1);
   }

   printf("OK\n");

   printf("Waiting for connections (Press Ctrl-C to exit)...");

   iAddrLen = sizeof(remote_addr);

   sClient = accept(sListen, (struct sockaddr *) &remote_addr, &iAddrLen);

   // Error?
   if(sClient == SOCKET_ERROR)
   {
      printf("Error\nCall to accept(sListen, (struct sockaddr *) remote_addr, sizeof(remote_addr)); failed with:\n%d\n", WSAGetLastError());
      exit(1);
   }

   printf("%s connected\n",
          inet_ntoa(remote_addr.sin_addr));
   closesocket(sListen);

}