ttelhndl.cpp

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//Telnet Win32 : an ANSI telnet client.
//Copyright (C) 1998  Paul Brannan
//Copyright (C) 1998  I.Ioannou
//Copyright (C) 1997  Brad Johnson
//
//This program is free software; you can redistribute it and/or
//modify it under the terms of the GNU General Public License
//as published by the Free Software Foundation; either version 2
//of the License, or (at your option) any later version.
//
//This program is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//GNU General Public License for more details.
//
//You should have received a copy of the GNU General Public License
//along with this program; if not, write to the Free Software
//Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
//I.Ioannou
//roryt@hol.gr
//

//
// Module:      ttelhndl.cpp
//
// Contents:    Telnet Handler
//
// Product:     telnet
//
// Revisions: August 30, 1998 Paul Brannan <pbranna@clemson.edu>
//            June 15, 1998   pbranna@clemson.edu (Paul Brannan)
//
//            This is code originally from tnnet.cpp and ansiprsr.cpp
//

#include "precomp.h"

int naws_string(char *buf, int width, int height);

// This helps make the code more readable (Paul Brannan 1/1/99)
#ifdef DEBUG_TELOPT
#define TELOPT_PRINTD(x) printit(x);
#define TELOPT_PRINTD2(x,n) {       \
    static char buf[20];            \
    printit(s);                     \
    printit(" ");                   \
    itoa(d, buf, 10);               \
    printit(buf);                   \
    printit("\n");                  \
}
#else
#define TELOPT_PRINTD(x) ;
#define TELOPT_PRINTD2(x,n) ;
#endif

// A new print function for debugging (Paul Brannan 5/15/98)
#ifdef DEBUG_TELOPT
void TTelnetHandler::print_telopt(const char *s, int d) {
    static char buf[20];
    printit(s);
    printit(" ");
    itoa(d, buf, 10);
    printit(buf);
    printit("\n");
}
#endif

TTelnetHandler::TTelnetHandler(TNetwork &RefNetwork, TConsole &RefConsole,
                               TParser &RefParser):
Network(RefNetwork), Console(RefConsole), Parser(RefParser) {
    init();

    // Paul Brannan 9/13/98
    dwBuffer = ini.get_buffer_size();
    szBuffer = new char [dwBuffer];
    Network.SetNawsFunc(NULL);
}

void TTelnetHandler::init() {
    iTermSet = 0;
    bInBinaryRx = 0;
    bInBinaryTx = 0;
    bInEchoTx = 0;
    bInEchoRx = 0;
    Network.set_local_echo(1);
}

TTelnetHandler::~TTelnetHandler() {
    delete[] szBuffer;
}

int TTelnetHandler::escapeIAC(char *buf, int length){
    // The size of buffer must be greater than 2 * length to ensure no memory
    // out of bounds errors.  The 0xff is escaped into 0xff 0xff.
    char * temp;
    temp = new char [length * 2];
    int current=0;
    for (int x=0; x < length; x++){
        if (buf[x] == (signed char)IAC)
            temp[current++]=(char)IAC;
        temp[current++]=buf[x];
    }
    memcpy( buf, temp, current);
    delete [] temp;
    return current;
}

// This lets us get rid of all the printf's (Paul Brannan 5/15/98)
void TTelnetHandler::SendIAC(char c) {
    static char buf[2] = {IAC};
    buf[1] = c;
    Network.WriteString(buf, 2);
}
void TTelnetHandler::SendIAC(char c1, char c2) {
    static char buf[3] = {IAC};
    buf[1] = c1; buf[2] = c2;
    Network.WriteString(buf, 3);
}
void TTelnetHandler::SendIACParams(char c) {
    static char buf[2];
    buf[0] = c;
    static int length = escapeIAC(buf, 1);
    Network.WriteString(buf, length);
}
void TTelnetHandler::SendIACParams(char c1, char c2) {
    static char buf[4];
    buf[0] = c1; buf[1] = c2;
    static int length = escapeIAC(buf, 2);
    Network.WriteString(buf, length);
}

int naws_string(char *b, int width, int height) {
    int l = 0;
    unsigned char *buf = (unsigned char *)b;

    union {
        char szResponse[2];
        int n;
    };

    buf[l++] = IAC;
    buf[l++] = SB;
    buf[l++] = TELOPT_NAWS;

    n = width;
    buf[l] = szResponse[1];
    if(buf[l-1] == IAC) buf[l++] = IAC;
    buf[l++] = szResponse[0];
    if(buf[l-1] == IAC) buf[l++] = IAC;

    n = height;
    buf[l++] = szResponse[1];
    if(buf[l-1] == IAC) buf[l++] = IAC;
    buf[l++] = szResponse[0];
    if(buf[l-1] == IAC) buf[l++] = IAC;

    buf[l++] = IAC;
    buf[l++] = SE;

    return l;
}

//  Ioannou 29 May 1998 : Something strange happens with
//  Borland compiler at this point when it passes the arguments
//  to SendIACParams. It always sends 80 lines to the server !!!
//  There seems to be a bug with optimization (the disassemble shows
//  that it uses an address plus 0xa than the right one).
//  This turns them off for this point.
#ifdef __BORLANDC__
#pragma -O-
#endif

// Removed old printf code that was commented out to clean this function
// up a bit (Paul brannan 6/15/98)
char* TTelnetHandler::ParseIAC(char* pszBuffer, char* pszBufferEnd)
{
    //  int n,l;
    //  char szResponse[40];
    //  Ioannou 29 May 1998 : I prefer the union redefinitions
    //  than the typecasting (used with them from Pascal and Cobol :-) )
    //  FIX ME !!!! Shall we use the winsock routines instead ?

    union {
        char szResponse[2];
        int n;
    };

    // Added support for user-defined term name (Paul Brannan 5/13/98)
#define LASTTERM 4
    const char *pszTerms[] =  {ini.get_term(), "ANSI","DEC-VT100","DEC-VT52","UNKNOWN"};
    if(!iTermSet && (pszTerms[0] == 0 || *pszTerms[0] == 0)) iTermSet++;

    if (pszBuffer + 2 < pszBufferEnd) {
        switch ((unsigned char)pszBuffer[1]) {

        case DO:
            {
                switch (pszBuffer[2]){
                case TELOPT_BINARY:
                    TELOPT_PRINTD("RCVD DO TELOPT_BINARY\n");
                    if (!bInBinaryRx){
                        SendIAC(WILL, TELOPT_BINARY);
                        bInBinaryRx = 1;
                        TELOPT_PRINTD("SENT WILL TELOPT_BINARY\n");
                    }
                    break;
                case TELOPT_ECHO:
                    // we shouldn't echo for the server! (Paul Brannan 5/30/98)
                    TELOPT_PRINTD2("RCVD DO TELOPT_ECHO", pszBuffer[2]);
                    SendIAC(WONT, TELOPT_ECHO);
                    TELOPT_PRINTD("SENT WONT TELOPT_ECHO\n");
                    break;
                case TELOPT_TTYPE:
                    TELOPT_PRINTD("RCVD DO TELOPT_TTYPE\n");
                    SendIAC(WILL, TELOPT_TTYPE);
                    TELOPT_PRINTD("SENT WILL TELOPT_TTYPE\n");
                    break;
                case TELOPT_NAWS:
                    TELOPT_PRINTD("RCVD DO TELOPT_NAWS\n");
                    SendIAC(WILL, TELOPT_NAWS);
                    SendIAC(SB, TELOPT_NAWS);

                    Network.SetNawsFunc(naws_string);

                    n = Console.GetWidth();
                    SendIACParams(szResponse[1],szResponse [0]);

                    n = Console.GetHeight();
                    SendIACParams(szResponse[1],szResponse[0]);

                    SendIAC(SE);
                    TELOPT_PRINTD("SENT WILL TELOPT_NAWS\n");
                    break;
                case TELOPT_XDISPLOC:
                    TELOPT_PRINTD("RCVD DO TELOPT_XDISPLOC\n");
                    SendIAC(WILL, TELOPT_XDISPLOC);
                    TELOPT_PRINTD("SENT WILL TELOPT_XDISPLOC\n");
                    printit("Retrieving IP...");
                        break;
                default:
                    TELOPT_PRINTD2("RCVD DO", pszBuffer[2]);
                    SendIAC(WONT, pszBuffer[2]);
                    TELOPT_PRINTD2("SENT WONT", pszBuffer[2]);
                    break;
                }
                if (pszBuffer + 2 < pszBufferEnd)
                    pszBuffer += 3;
                break;
            }

        case WILL:
            {
                switch ((unsigned char)pszBuffer[2]){
                case TELOPT_BINARY:
                    TELOPT_PRINTD("RCVD WILL TELOPT_BINARY\n");
                    if (!bInBinaryTx){
                        SendIAC(DO, TELOPT_BINARY);
                        bInBinaryTx = 1;
                        TELOPT_PRINTD("SENT DO TELOPT_BINARY\n");
                    }
                    break;
                case TELOPT_ECHO:
                    TELOPT_PRINTD2("RCVD WILL TELOPT_ECHO", pszBuffer[2]);
                    if(!bInEchoRx) {
                        SendIAC(DO, TELOPT_ECHO);
                        bInEchoRx = 1;
                        Network.set_local_echo(0); // Paul Brannan 8/25/98
                        if(iWillSGA) Network.set_line_mode(0);
                        TELOPT_PRINTD2("SENT DO TELOPT_ECHO", pszBuffer[2]);
                        if(Network.get_local_echo()) Network.set_line_mode(0);
                    }
                    break;

                    // Suppress Go Ahead (Paul Brannan 12/31/98)
                case TELOPT_SGA:
                    TELOPT_PRINTD("RCVD WILL TELOPT_SGA\n");
                    if(!iWillSGA) {
                        SendIAC(DO, TELOPT_SGA);
                        if(bInEchoRx) Network.set_line_mode(0);
                        iWillSGA = 1;
                        TELOPT_PRINTD("SENT DO TELOPT_SGA\n");
                    }
                    break;

                default:
                    TELOPT_PRINTD2("RCVD WILL", pszBuffer[2]);
                    SendIAC(DONT, pszBuffer[2]);
                    TELOPT_PRINTD2("SENT DONT", pszBuffer[2]);
                    break;
                }
                if (pszBuffer + 2 < pszBufferEnd)
                    pszBuffer += 3;
                break;
            }

        case WONT:
            {
                switch ((unsigned char)pszBuffer[2]){
                case TELOPT_ECHO:
                    TELOPT_PRINTD("RCVD WONT TELOPT_ECHO\n");
                    if (bInEchoRx){
                        SendIAC(DONT, TELOPT_ECHO);
                        // bInBinaryRx = 0;
                        bInEchoRx = 0; // Paul Brannan 8/25/98
                        Network.set_local_echo(1);
                        Network.set_line_mode(0);
                        TELOPT_PRINTD("SENT DONT TELOPT_ECHO\n");
                    }
                    break;

                    // Suppress Go Ahead (Paul Brannan 12/31/98)
                case TELOPT_SGA:
                    TELOPT_PRINTD("RCVD WONT TELOPT_SGA\n");
                    if(iWillSGA) {
                        SendIAC(DONT, TELOPT_SGA);
                        Network.set_line_mode(0);
                        iWillSGA = 0;
                        TELOPT_PRINTD("SENT DONT TELOPT_SGA\n");
                    }
                    break;

                default:
                    TELOPT_PRINTD2("RCVD WONT", pszBuffer[2]);
                    break;
                }
                if (pszBuffer + 2 < pszBufferEnd)
                    pszBuffer += 3;
                break;
            }

        case DONT:
            {
                switch ((unsigned char)pszBuffer[2]){
                case TELOPT_ECHO:
                    TELOPT_PRINTD("RCVD DONT TELOPT_ECHO\n");
                    if (bInEchoTx){
                        SendIAC(WONT, TELOPT_ECHO);
                        bInEchoTx = 0;
                        TELOPT_PRINTD("SENT WONT TELOPT_ECHO\n");
                    }
                    break;
                case TELOPT_NAWS:
                    TELOPT_PRINTD("RCVD DONT TELOPT_NAWS\n");
                    SendIAC(WONT, TELOPT_NAWS);
                    Network.SetNawsFunc(naws_string);
                    TELOPT_PRINTD("SENT WONT TELOPT_NAWS\n");
                    break;
                default:
                    TELOPT_PRINTD2("RCVD DONT", pszBuffer[2]);
                    break;
                }
                if (pszBuffer + 2 < pszBufferEnd)
                    pszBuffer += 3;
                break;
            }

        case SB:
            {
                switch ((unsigned char)pszBuffer[2]){
                case TELOPT_TTYPE:
                    if (pszBuffer + 5 < pszBufferEnd) {
                        TELOPT_PRINTD("RCVD SB TELOPT_TTYPE\n");
                        if (pszBuffer[3] == 1){
                            TELOPT_PRINTD("SENT SB TT");
                            TELOPT_PRINTD(pszTerms[iTermSet]);
                            TELOPT_PRINTD("\n");
                            SendIAC(SB, TELOPT_TTYPE);
                            SendIACParams(0);
                            Network.WriteString(pszTerms[iTermSet], strlen(pszTerms[iTermSet]));
                            SendIAC(SE);

                            if (iTermSet < LASTTERM )
                                iTermSet+=1;
                        }
                        if (pszBuffer + 5 < pszBufferEnd)
                            pszBuffer += 6;
                    }
                        break;
                case TELOPT_XDISPLOC:
                    if(pszBuffer + 5 < pszBufferEnd) {
                        TELOPT_PRINTD("RCVD SB XDISPLOC\n");
                        SendIAC(SB, TELOPT_XDISPLOC);
                        TELOPT_PRINTD("SENT SB XDISPLOC");
                        SendIACParams(0);
                        if(Network.GetLocalAddress()) Network.WriteString(Network.GetLocalAddress(),
                            strlen(Network.GetLocalAddress()));
                        TELOPT_PRINTD(Network.GetLocalAddress());
                        TELOPT_PRINTD("\n");
                        SendIAC(SE);
                        if (pszBuffer + 5 < pszBufferEnd)
                            pszBuffer += 6;
                    }
                    break;
                default: break;
                }
                break;
            }
        default:
            pszBuffer += 2;
            break;
        }
    }
    return pszBuffer;
}

#ifdef __BORLANDC__
// bring bug optimazations
#pragma -O.
#endif

// This is the code from TANSIParser::ParseBuffer.  It parses out IACs, and
// then calls TParser::ParseBuffer to do the terminal emulation.
// (Paul Brannan 6/15/98)
// Hopefully eliminating the unnecessary copying should speed things up a
// little.  (Paul Brannan 6/28/98)
char* TTelnetHandler::ParseBuffer(char* pszBuffer, char* pszBufferEnd){
    char *pszResult;
    char *pszHead = pszBuffer;

    if(Network.get_net_type() == TN_NETSOCKET) {
        while (pszBuffer < pszBufferEnd) {
            // if IAC then parse IAC
            if((unsigned char) *pszBuffer == IAC) {

                // check for escaped IAC
                if((pszBufferEnd >= pszBuffer + 1) &&
                    (unsigned char)*(pszBuffer + 1) == IAC) {
                    // we move data at the front of the buffer to the end so
                    // that if we only have IACs we won't return pszBuffer
                    // even though we did parse something.  Returning
                    // pszBuffer is an error condition.
                    memmove(pszHead + 1, pszHead, pszBuffer - pszHead);
                    pszBuffer+=2;
                    pszHead++;
                }
                // parse the IAC
                else {
                    pszResult = ParseIAC(pszBuffer, pszBufferEnd);
                    if(pszBuffer == pszResult) return pszBuffer;
                    // see above regarding moving from front to end.
                    memmove(pszHead + (pszResult - pszBuffer), pszHead,
                        pszBuffer - pszHead);
                    pszHead += (pszResult - pszBuffer);
                    pszBuffer = pszResult;
                }
            }
            // else copy char over to ANSI buffer
            else {
                pszBuffer++;
            }
        }

    // Not a socket connection, so don't parse out IACs.
    // (Paul Brannan 3/19/99)
    } else {
        pszBuffer = pszBufferEnd;
    }

    return(Parser.ParseBuffer(pszHead, pszBuffer));
}

// telProcessNetwork calls the member function TTelnetHandler::Go, since
// TTelnetHandler::Go is not a static function, and cannot be called with
// CreateThread().  (Paul Brannan 6/15/98)
DWORD WINAPI telProcessNetwork(LPVOID lpParameter) {
    TelThreadParams *pParams = (TelThreadParams *)lpParameter;
    return pParams->TelHandler.Go(&pParams->p);
}

// This function is what used to be telProcessNetwork (Paul Brannan 6/15/98)
DWORD TTelnetHandler::Go(LPVOID pvParams)
{
    NetParams *pParams = (NetParams *)pvParams;

    // No longer a need to copy pParams-> socket and create an instance
    // of TANSIParser (Paul Brannan 6/15/98)

    Console.sync(); // Sync with the parser so the cursor is positioned

    Parser.Init(); // Reset the parser (Paul Brannan 9/19/98)
    init(); // Turn on local echo (Paul Brannan 9/19/98)

    *pParams->bNetFinished = 0;
    char* pszHead = szBuffer;
    char* pszTail = szBuffer;
    while (!*pParams->bNetFinish) {
        // Get data from Socket
        *pParams->bNetPaused = 1;  //Pause
        int Result = Network.ReadString(pszTail, (szBuffer + dwBuffer) - pszTail);

        // Speed up mouse by not going into loop (Paul Brannan 8/10/98)
        // while(*pParams->bNetPause && !*pParams->bNetFinish) *pParams->bNetPaused = 1;  //Pause
        if(WaitForSingleObject(pParams->hPause, 0) == WAIT_OBJECT_0)
            WaitForSingleObject(pParams->hUnPause, INFINITE);

        *pParams->bNetPaused = 0;  //UnPause

        if (Result <= 0 || Result > dwBuffer ){
            break;
        }
        pszTail += Result;

        // Process the buffer
        char* pszNewHead = pszHead;
        do {
            // Speed up mouse by not going into loop (Paul Brannan 8/10/98)
            if(WaitForSingleObject(pParams->hPause, 0) == WAIT_OBJECT_0) {
                *pParams->bNetPaused = 1;
                WaitForSingleObject(pParams->hUnPause, INFINITE);
                *pParams->bNetPaused = 0;
            }

            pszHead = pszNewHead;
            pszNewHead = ParseBuffer(pszHead, pszTail); // Parse buffer
        } while ((pszNewHead != pszHead) && (pszNewHead < pszTail) && !*pParams->bNetFinish);
        pszHead = pszNewHead;

        // When we reach the end of the buffer, move contents to the
        // beginning of the buffer to get free space at the end.
        if (pszTail == (szBuffer + dwBuffer)) {
            memmove(szBuffer, pszHead, pszTail - pszHead);
            pszTail = szBuffer + (pszTail - pszHead);
            pszHead = szBuffer;
        }
    }
    SetEvent(pParams->hExit);

    printm(0, FALSE, MSG_TERMBYREM);
    *pParams->bNetPaused = 1;  //Pause
    *pParams->bNetFinished = 1;
    return 0;
}