Ejemplo n.º 1
0
Archivo: state.c Proyecto: MarginC/kame
void
telrcv()
{
    register int c;
    static int state = TS_DATA;
#if	defined(CRAY2) && defined(UNICOS5)
    char *opfrontp = pfrontp;
#endif

    while (ncc > 0) {
        if ((&ptyobuf[BUFSIZ] - pfrontp) < 2)
            break;
        c = *netip++ & 0377, ncc--;
        switch (state) {

        case TS_CR:
            state = TS_DATA;
            /* Strip off \n or \0 after a \r */
            if ((c == 0) || (c == '\n')) {
                break;
            }
        /* FALL THROUGH */

        case TS_DATA:
            if (c == IAC) {
                state = TS_IAC;
                break;
            }
            /*
             * We now map \r\n ==> \r for pragmatic reasons.
             * Many client implementations send \r\n when
             * the user hits the CarriageReturn key.
             *
             * We USED to map \r\n ==> \n, since \r\n says
             * that we want to be in column 1 of the next
             * printable line, and \n is the standard
             * unix way of saying that (\r is only good
             * if CRMOD is set, which it normally is).
             */
            if ((c == '\r') && his_state_is_wont(TELOPT_BINARY)) {
                int nc = *netip;
#ifdef	LINEMODE
                /*
                 * If we are operating in linemode,
                 * convert to local end-of-line.
                 */
                if (linemode && (ncc > 0) && (('\n' == nc) ||
                                              ((0 == nc) && tty_iscrnl())) ) {
                    netip++;
                    ncc--;
                    c = '\n';
                } else
#endif
                {
                    state = TS_CR;
                }
            }
            *pfrontp++ = c;
            break;

        case TS_IAC:
gotiac:
            switch (c) {

            /*
             * Send the process on the pty side an
             * interrupt.  Do this with a NULL or
             * interrupt char; depending on the tty mode.
             */
            case IP:
                DIAG(TD_OPTIONS,
                     printoption("td: recv IAC", c));
                interrupt();
                break;

            case BREAK:
                DIAG(TD_OPTIONS,
                     printoption("td: recv IAC", c));
                sendbrk();
                break;

            /*
             * Are You There?
             */
            case AYT:
                DIAG(TD_OPTIONS,
                     printoption("td: recv IAC", c));
                recv_ayt();
                break;

            /*
             * Abort Output
             */
            case AO:
            {
                DIAG(TD_OPTIONS,
                     printoption("td: recv IAC", c));
                ptyflush();	/* half-hearted */
                init_termbuf();

                if (slctab[SLC_AO].sptr &&
                        *slctab[SLC_AO].sptr != (cc_t)(_POSIX_VDISABLE)) {
                    *pfrontp++ =
                        (unsigned char)*slctab[SLC_AO].sptr;
                }

                netclear();	/* clear buffer back */
                *nfrontp++ = IAC;
                *nfrontp++ = DM;
                neturg = nfrontp-1; /* off by one XXX */
                DIAG(TD_OPTIONS,
                     printoption("td: send IAC", DM));
                break;
            }

            /*
             * Erase Character and
             * Erase Line
             */
            case EC:
            case EL:
            {
                cc_t ch;

                DIAG(TD_OPTIONS,
                     printoption("td: recv IAC", c));
                ptyflush();	/* half-hearted */
                init_termbuf();
                if (c == EC)
                    ch = *slctab[SLC_EC].sptr;
                else
                    ch = *slctab[SLC_EL].sptr;
                if (ch != (cc_t)(_POSIX_VDISABLE))
                    *pfrontp++ = (unsigned char)ch;
                break;
            }

            /*
             * Check for urgent data...
             */
            case DM:
                DIAG(TD_OPTIONS,
                     printoption("td: recv IAC", c));
                SYNCHing = stilloob(net);
                settimer(gotDM);
                break;


            /*
             * Begin option subnegotiation...
             */
            case SB:
                state = TS_SB;
                SB_CLEAR();
                continue;

            case WILL:
                state = TS_WILL;
                continue;

            case WONT:
                state = TS_WONT;
                continue;

            case DO:
                state = TS_DO;
                continue;

            case DONT:
                state = TS_DONT;
                continue;
            case EOR:
                if (his_state_is_will(TELOPT_EOR))
                    doeof();
                break;

            /*
             * Handle RFC 10xx Telnet linemode option additions
             * to command stream (EOF, SUSP, ABORT).
             */
            case xEOF:
                doeof();
                break;

            case SUSP:
                sendsusp();
                break;

            case ABORT:
                sendbrk();
                break;

            case IAC:
                *pfrontp++ = c;
                break;
            }
            state = TS_DATA;
            break;

        case TS_SB:
            if (c == IAC) {
                state = TS_SE;
            } else {
                SB_ACCUM(c);
            }
            break;

        case TS_SE:
            if (c != SE) {
                if (c != IAC) {
                    /*
                     * bad form of suboption negotiation.
                     * handle it in such a way as to avoid
                     * damage to local state.  Parse
                     * suboption buffer found so far,
                     * then treat remaining stream as
                     * another command sequence.
                     */

                    /* for DIAGNOSTICS */
                    SB_ACCUM(IAC);
                    SB_ACCUM(c);
                    subpointer -= 2;

                    SB_TERM();
                    suboption();
                    state = TS_IAC;
                    goto gotiac;
                }
                SB_ACCUM(c);
                state = TS_SB;
            } else {
                /* for DIAGNOSTICS */
                SB_ACCUM(IAC);
                SB_ACCUM(SE);
                subpointer -= 2;

                SB_TERM();
                suboption();	/* handle sub-option */
                state = TS_DATA;
            }
            break;

        case TS_WILL:
            willoption(c);
            state = TS_DATA;
            continue;

        case TS_WONT:
            wontoption(c);
            state = TS_DATA;
            continue;

        case TS_DO:
            dooption(c);
            state = TS_DATA;
            continue;

        case TS_DONT:
            dontoption(c);
            state = TS_DATA;
            continue;

        default:
            syslog(LOG_ERR, "telnetd: panic state=%d\n", state);
            printf("telnetd: panic state=%d\n", state);
            exit(1);
        }
    }
#if	defined(CRAY2) && defined(UNICOS5)
    if (!linemode) {
        char	xptyobuf[BUFSIZ+NETSLOP];
        char	xbuf2[BUFSIZ];
        register char *cp;
        int n = pfrontp - opfrontp, oc;
        memmove(xptyobuf, opfrontp, n);
        pfrontp = opfrontp;
        pfrontp += term_input(xptyobuf, pfrontp, n, BUFSIZ+NETSLOP,
                              xbuf2, &oc, BUFSIZ);
        for (cp = xbuf2; oc > 0; --oc)
            if ((*nfrontp++ = *cp++) == IAC)
                *nfrontp++ = IAC;
    }
#endif	/* defined(CRAY2) && defined(UNICOS5) */
}  /* end of telrcv */
Ejemplo n.º 2
0
int
telrcv(void)
{
    int c;
    int scc;
    unsigned char *sbp;
    int count;
    int returnValue = 0;

    scc = 0;
    count = 0;
    while (TTYROOM() > 2) {
	if (scc == 0) {
	    if (count) {
		ring_consumed(&netiring, count);
		returnValue = 1;
		count = 0;
	    }
	    sbp = netiring.consume;
	    scc = ring_full_consecutive(&netiring);
	    if (scc == 0) {
		/* No more data coming in */
		break;
	    }
	}

	c = *sbp++ & 0xff, scc--; count++;
#ifdef	ENCRYPTION
	if (decrypt_input)
		c = (*decrypt_input)(c);
#endif	/* ENCRYPTION */

	switch (telrcv_state) {

	case TS_CR:
	    telrcv_state = TS_DATA;
	    if (c == '\0') {
		break;	/* Ignore \0 after CR */
	    }
	    else if ((c == '\n') && my_want_state_is_dont(TELOPT_ECHO) && !crmod) {
		TTYADD(c);
		break;
	    }
	    /* Else, fall through */

	case TS_DATA:
	    if (c == IAC) {
		telrcv_state = TS_IAC;
		break;
	    }
		    /*
		     * The 'crmod' hack (see following) is needed
		     * since we can't * set CRMOD on output only.
		     * Machines like MULTICS like to send \r without
		     * \n; since we must turn off CRMOD to get proper
		     * input, the mapping is done here (sigh).
		     */
	    if ((c == '\r') && my_want_state_is_dont(TELOPT_BINARY)) {
		if (scc > 0) {
		    c = *sbp&0xff;
#ifdef	ENCRYPTION
		    if (decrypt_input)
			c = (*decrypt_input)(c);
#endif	/* ENCRYPTION */
		    if (c == 0) {
			sbp++, scc--; count++;
			/* a "true" CR */
			TTYADD('\r');
		    } else if (my_want_state_is_dont(TELOPT_ECHO) &&
					(c == '\n')) {
			sbp++, scc--; count++;
			TTYADD('\n');
		    } else {
#ifdef	ENCRYPTION
			if (decrypt_input)
			    (*decrypt_input)(-1);
#endif	/* ENCRYPTION */

			TTYADD('\r');
			if (crmod) {
				TTYADD('\n');
			}
		    }
		} else {
		    telrcv_state = TS_CR;
		    TTYADD('\r');
		    if (crmod) {
			    TTYADD('\n');
		    }
		}
	    } else {
		TTYADD(c);
	    }
	    continue;

	case TS_IAC:
process_iac:
	    switch (c) {

	    case WILL:
		telrcv_state = TS_WILL;
		continue;

	    case WONT:
		telrcv_state = TS_WONT;
		continue;

	    case DO:
		telrcv_state = TS_DO;
		continue;

	    case DONT:
		telrcv_state = TS_DONT;
		continue;

	    case DM:
		    /*
		     * We may have missed an urgent notification,
		     * so make sure we flush whatever is in the
		     * buffer currently.
		     */
		printoption("RCVD", IAC, DM);
		SYNCHing = 1;
		(void) ttyflush(1);
		SYNCHing = stilloob();
		settimer(gotDM);
		break;

	    case SB:
		SB_CLEAR();
		telrcv_state = TS_SB;
		continue;

	    case IAC:
		TTYADD(IAC);
		break;

	    case NOP:
	    case GA:
	    default:
		printoption("RCVD", IAC, c);
		break;
	    }
	    telrcv_state = TS_DATA;
	    continue;

	case TS_WILL:
	    printoption("RCVD", WILL, c);
	    willoption(c);
	    telrcv_state = TS_DATA;
	    continue;

	case TS_WONT:
	    printoption("RCVD", WONT, c);
	    wontoption(c);
	    telrcv_state = TS_DATA;
	    continue;

	case TS_DO:
	    printoption("RCVD", DO, c);
	    dooption(c);
	    if (c == TELOPT_NAWS) {
		sendnaws();
	    } else if (c == TELOPT_LFLOW) {
		localflow = 1;
		setcommandmode();
		setconnmode(0);
	    }
	    telrcv_state = TS_DATA;
	    continue;

	case TS_DONT:
	    printoption("RCVD", DONT, c);
	    dontoption(c);
	    flushline = 1;
	    setconnmode(0);	/* set new tty mode (maybe) */
	    telrcv_state = TS_DATA;
	    continue;

	case TS_SB:
	    if (c == IAC) {
		telrcv_state = TS_SE;
	    } else {
		SB_ACCUM(c);
	    }
	    continue;

	case TS_SE:
	    if (c != SE) {
		if (c != IAC) {
		    /*
		     * This is an error.  We only expect to get
		     * "IAC IAC" or "IAC SE".  Several things may
		     * have happend.  An IAC was not doubled, the
		     * IAC SE was left off, or another option got
		     * inserted into the suboption are all possibilities.
		     * If we assume that the IAC was not doubled,
		     * and really the IAC SE was left off, we could
		     * get into an infinate loop here.  So, instead,
		     * we terminate the suboption, and process the
		     * partial suboption if we can.
		     */
		    SB_ACCUM(IAC);
		    SB_ACCUM(c);
		    subpointer -= 2;
		    SB_TERM();

		    printoption("In SUBOPTION processing, RCVD", IAC, c);
		    suboption();	/* handle sub-option */
		    telrcv_state = TS_IAC;
		    goto process_iac;
		}
		SB_ACCUM(c);
		telrcv_state = TS_SB;
	    } else {
		SB_ACCUM(IAC);
		SB_ACCUM(SE);
		subpointer -= 2;
		SB_TERM();
		suboption();	/* handle sub-option */
		telrcv_state = TS_DATA;
	    }
	}
    }
    if (count)
	ring_consumed(&netiring, count);
    return returnValue||count;
}
Ejemplo n.º 3
0
/*
 * Main loop.  Select from pty and network, and
 * hand data to telnet receiver finite state machine.
 */
void telnet(int f, int p)
{
    int on = 1;
    char *HE;
    const char *IM;

    /*
     * Initialize the slc mapping table.
     */
    get_slc_defaults();

    /*
     * Do some tests where it is desireable to wait for a response.
     * Rather than doing them slowly, one at a time, do them all
     * at once.
     */
    if (my_state_is_wont(TELOPT_SGA))
	send_will(TELOPT_SGA, 1);
    /*
     * Is the client side a 4.2 (NOT 4.3) system?  We need to know this
     * because 4.2 clients are unable to deal with TCP urgent data.
     *
     * To find out, we send out a "DO ECHO".  If the remote system
     * answers "WILL ECHO" it is probably a 4.2 client, and we note
     * that fact ("WILL ECHO" ==> that the client will echo what
     * WE, the server, sends it; it does NOT mean that the client will
     * echo the terminal input).
     */
    send_do(TELOPT_ECHO, 1);
    
#ifdef	LINEMODE
    if (his_state_is_wont(TELOPT_LINEMODE)) {
	/*
	 * Query the peer for linemode support by trying to negotiate
	 * the linemode option.
	 */
	linemode = 0;
	editmode = 0;
	send_do(TELOPT_LINEMODE, 1);  /* send do linemode */
    }
#endif	/* LINEMODE */

    /*
     * Send along a couple of other options that we wish to negotiate.
     */
    send_do(TELOPT_NAWS, 1);
    send_will(TELOPT_STATUS, 1);
    flowmode = 1;  /* default flow control state */
    send_do(TELOPT_LFLOW, 1);
    
    /*
     * Spin, waiting for a response from the DO ECHO.  However,
     * some REALLY DUMB telnets out there might not respond
     * to the DO ECHO.  So, we spin looking for NAWS, (most dumb
     * telnets so far seem to respond with WONT for a DO that
     * they don't understand...) because by the time we get the
     * response, it will already have processed the DO ECHO.
     * Kludge upon kludge.
     */
    while (his_will_wont_is_changing(TELOPT_NAWS)) {
	ttloop();
    }
    
    /*
     * But...
     * The client might have sent a WILL NAWS as part of its
     * startup code; if so, we'll be here before we get the
     * response to the DO ECHO.  We'll make the assumption
     * that any implementation that understands about NAWS
     * is a modern enough implementation that it will respond
     * to our DO ECHO request; hence we'll do another spin
     * waiting for the ECHO option to settle down, which is
     * what we wanted to do in the first place...
     */
    if (his_want_state_is_will(TELOPT_ECHO) &&
	his_state_is_will(TELOPT_NAWS)) {
	while (his_will_wont_is_changing(TELOPT_ECHO))
	    ttloop();
    }
    /*
     * On the off chance that the telnet client is broken and does not
     * respond to the DO ECHO we sent, (after all, we did send the
     * DO NAWS negotiation after the DO ECHO, and we won't get here
     * until a response to the DO NAWS comes back) simulate the
     * receipt of a will echo.  This will also send a WONT ECHO
     * to the client, since we assume that the client failed to
     * respond because it believes that it is already in DO ECHO
     * mode, which we do not want.
     */
    if (his_want_state_is_will(TELOPT_ECHO)) {
	DIAG(TD_OPTIONS, netoprintf("td: simulating recv\r\n"););
	willoption(TELOPT_ECHO);
    }