xref: /freebsd-11-stable/contrib/telnet/telnet/utilities.c

/*
 * Copyright (c) 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if 0
#ifndef lint
static const char sccsid[] = "@(#)utilities.c	8.3 (Berkeley) 5/30/95";
#endif
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: stable/11/contrib/telnet/telnet/utilities.c 351432 2019-08-23 17:40:47Z emaste $");

#define	TELOPTS
#define	TELCMDS
#define	SLC_NAMES
#include <arpa/telnet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>

#include "general.h"

#include "fdset.h"

#include "ring.h"

#include "defines.h"

#include "externs.h"

#ifdef	AUTHENTICATION
#include <libtelnet/auth.h>
#endif
#ifdef	ENCRYPTION
#include <libtelnet/encrypt.h>
#endif

FILE	*NetTrace = 0;		/* Not in bss, since needs to stay */
int	prettydump;

/*
 * upcase()
 *
 *	Upcase (in place) the argument.
 */

void
upcase(char *argument)
{
    int c;

    while ((c = *argument) != 0) {
	if (islower(c)) {
	    *argument = toupper(c);
	}
	argument++;
    }
}

/*
 * SetSockOpt()
 *
 * Compensate for differences in 4.2 and 4.3 systems.
 */

int
SetSockOpt(int fd, int level, int option, int yesno)
{
    return setsockopt(fd, level, option,
				(char *)&yesno, sizeof yesno);
}

/*
 * The following are routines used to print out debugging information.
 */

unsigned char NetTraceFile[256] = "(standard output)";

void
SetNetTrace(char *file)
{
    if (NetTrace && NetTrace != stdout)
	fclose(NetTrace);
    if (file  && (strcmp(file, "-") != 0)) {
	NetTrace = fopen(file, "w");
	if (NetTrace) {
	    strcpy((char *)NetTraceFile, file);
	    return;
	}
	fprintf(stderr, "Cannot open %s.\n", file);
    }
    NetTrace = stdout;
    strcpy((char *)NetTraceFile, "(standard output)");
}

void
Dump(char direction, unsigned char *buffer, int length)
{
#   define BYTES_PER_LINE	32
#   define min(x,y)	((x<y)? x:y)
    unsigned char *pThis;
    int offset;

    offset = 0;

    while (length) {
	/* print one line */
	fprintf(NetTrace, "%c 0x%x\t", direction, offset);
	pThis = buffer;
	if (prettydump) {
	    buffer = buffer + min(length, BYTES_PER_LINE/2);
	    while (pThis < buffer) {
		fprintf(NetTrace, "%c%.2x",
		    (((*pThis)&0xff) == 0xff) ? '*' : ' ',
		    (*pThis)&0xff);
		pThis++;
	    }
	    length -= BYTES_PER_LINE/2;
	    offset += BYTES_PER_LINE/2;
	} else {
	    buffer = buffer + min(length, BYTES_PER_LINE);
	    while (pThis < buffer) {
		fprintf(NetTrace, "%.2x", (*pThis)&0xff);
		pThis++;
	    }
	    length -= BYTES_PER_LINE;
	    offset += BYTES_PER_LINE;
	}
	if (NetTrace == stdout) {
	    fprintf(NetTrace, "\r\n");
	} else {
	    fprintf(NetTrace, "\n");
	}
	if (length < 0) {
	    fflush(NetTrace);
	    return;
	}
	/* find next unique line */
    }
    fflush(NetTrace);
}


void
printoption(const char *direction, int cmd, int option)
{
	if (!showoptions)
		return;
	if (cmd == IAC) {
		if (TELCMD_OK(option))
		    fprintf(NetTrace, "%s IAC %s", direction, TELCMD(option));
		else
		    fprintf(NetTrace, "%s IAC %d", direction, option);
	} else {
		const char *fmt;
		fmt = (cmd == WILL) ? "WILL" : (cmd == WONT) ? "WONT" :
			(cmd == DO) ? "DO" : (cmd == DONT) ? "DONT" : 0;
		if (fmt) {
		    fprintf(NetTrace, "%s %s ", direction, fmt);
		    if (TELOPT_OK(option))
			fprintf(NetTrace, "%s", TELOPT(option));
		    else if (option == TELOPT_EXOPL)
			fprintf(NetTrace, "EXOPL");
		    else
			fprintf(NetTrace, "%d", option);
		} else
		    fprintf(NetTrace, "%s %d %d", direction, cmd, option);
	}
	if (NetTrace == stdout) {
	    fprintf(NetTrace, "\r\n");
	    fflush(NetTrace);
	} else {
	    fprintf(NetTrace, "\n");
	}
	return;
}

void
optionstatus(void)
{
    int i;
    extern char will_wont_resp[], do_dont_resp[];

    for (i = 0; i < 256; i++) {
	if (do_dont_resp[i]) {
	    if (TELOPT_OK(i))
		printf("resp DO_DONT %s: %d\n", TELOPT(i), do_dont_resp[i]);
	    else if (TELCMD_OK(i))
		printf("resp DO_DONT %s: %d\n", TELCMD(i), do_dont_resp[i]);
	    else
		printf("resp DO_DONT %d: %d\n", i,
				do_dont_resp[i]);
	    if (my_want_state_is_do(i)) {
		if (TELOPT_OK(i))
		    printf("want DO   %s\n", TELOPT(i));
		else if (TELCMD_OK(i))
		    printf("want DO   %s\n", TELCMD(i));
		else
		    printf("want DO   %d\n", i);
	    } else {
		if (TELOPT_OK(i))
		    printf("want DONT %s\n", TELOPT(i));
		else if (TELCMD_OK(i))
		    printf("want DONT %s\n", TELCMD(i));
		else
		    printf("want DONT %d\n", i);
	    }
	} else {
	    if (my_state_is_do(i)) {
		if (TELOPT_OK(i))
		    printf("     DO   %s\n", TELOPT(i));
		else if (TELCMD_OK(i))
		    printf("     DO   %s\n", TELCMD(i));
		else
		    printf("     DO   %d\n", i);
	    }
	}
	if (will_wont_resp[i]) {
	    if (TELOPT_OK(i))
		printf("resp WILL_WONT %s: %d\n", TELOPT(i), will_wont_resp[i]);
	    else if (TELCMD_OK(i))
		printf("resp WILL_WONT %s: %d\n", TELCMD(i), will_wont_resp[i]);
	    else
		printf("resp WILL_WONT %d: %d\n",
				i, will_wont_resp[i]);
	    if (my_want_state_is_will(i)) {
		if (TELOPT_OK(i))
		    printf("want WILL %s\n", TELOPT(i));
		else if (TELCMD_OK(i))
		    printf("want WILL %s\n", TELCMD(i));
		else
		    printf("want WILL %d\n", i);
	    } else {
		if (TELOPT_OK(i))
		    printf("want WONT %s\n", TELOPT(i));
		else if (TELCMD_OK(i))
		    printf("want WONT %s\n", TELCMD(i));
		else
		    printf("want WONT %d\n", i);
	    }
	} else {
	    if (my_state_is_will(i)) {
		if (TELOPT_OK(i))
		    printf("     WILL %s\n", TELOPT(i));
		else if (TELCMD_OK(i))
		    printf("     WILL %s\n", TELCMD(i));
		else
		    printf("     WILL %d\n", i);
	    }
	}
    }

}

void
printsub(char direction, unsigned char *pointer, int length)
{
    int i;
#ifdef	AUTHENTICATION
    char buf[512];
#endif
    extern int want_status_response;

    if (showoptions || direction == 0 ||
	(want_status_response && (pointer[0] == TELOPT_STATUS))) {
	if (direction) {
	    fprintf(NetTrace, "%s IAC SB ",
				(direction == '<')? "RCVD":"SENT");
	    if (length >= 3) {
		int j;

		i = pointer[length-2];
		j = pointer[length-1];

		if (i != IAC || j != SE) {
		    fprintf(NetTrace, "(terminated by ");
		    if (TELOPT_OK(i))
			fprintf(NetTrace, "%s ", TELOPT(i));
		    else if (TELCMD_OK(i))
			fprintf(NetTrace, "%s ", TELCMD(i));
		    else
			fprintf(NetTrace, "%d ", i);
		    if (TELOPT_OK(j))
			fprintf(NetTrace, "%s", TELOPT(j));
		    else if (TELCMD_OK(j))
			fprintf(NetTrace, "%s", TELCMD(j));
		    else
			fprintf(NetTrace, "%d", j);
		    fprintf(NetTrace, ", not IAC SE!) ");
		}
	    }
	    length -= 2;
	}
	if (length < 1) {
	    fprintf(NetTrace, "(Empty suboption??\?)");
	    if (NetTrace == stdout)
		fflush(NetTrace);
	    return;
	}
	switch (pointer[0]) {
	case TELOPT_TTYPE:
	    fprintf(NetTrace, "TERMINAL-TYPE ");
	    switch (pointer[1]) {
	    case TELQUAL_IS:
		fprintf(NetTrace, "IS \"%.*s\"", length-2, (char *)pointer+2);
		break;
	    case TELQUAL_SEND:
		fprintf(NetTrace, "SEND");
		break;
	    default:
		fprintf(NetTrace,
				"- unknown qualifier %d (0x%x).",
				pointer[1], pointer[1]);
	    }
	    break;
	case TELOPT_TSPEED:
	    fprintf(NetTrace, "TERMINAL-SPEED");
	    if (length < 2) {
		fprintf(NetTrace, " (empty suboption??\?)");
		break;
	    }
	    switch (pointer[1]) {
	    case TELQUAL_IS:
		fprintf(NetTrace, " IS ");
		fprintf(NetTrace, "%.*s", length-2, (char *)pointer+2);
		break;
	    default:
		if (pointer[1] == 1)
		    fprintf(NetTrace, " SEND");
		else
		    fprintf(NetTrace, " %d (unknown)", pointer[1]);
		for (i = 2; i < length; i++)
		    fprintf(NetTrace, " ?%d?", pointer[i]);
		break;
	    }
	    break;

	case TELOPT_LFLOW:
	    fprintf(NetTrace, "TOGGLE-FLOW-CONTROL");
	    if (length < 2) {
		fprintf(NetTrace, " (empty suboption??\?)");
		break;
	    }
	    switch (pointer[1]) {
	    case LFLOW_OFF:
		fprintf(NetTrace, " OFF"); break;
	    case LFLOW_ON:
		fprintf(NetTrace, " ON"); break;
	    case LFLOW_RESTART_ANY:
		fprintf(NetTrace, " RESTART-ANY"); break;
	    case LFLOW_RESTART_XON:
		fprintf(NetTrace, " RESTART-XON"); break;
	    default:
		fprintf(NetTrace, " %d (unknown)", pointer[1]);
	    }
	    for (i = 2; i < length; i++)
		fprintf(NetTrace, " ?%d?", pointer[i]);
	    break;

	case TELOPT_NAWS:
	    fprintf(NetTrace, "NAWS");
	    if (length < 2) {
		fprintf(NetTrace, " (empty suboption??\?)");
		break;
	    }
	    if (length == 2) {
		fprintf(NetTrace, " ?%d?", pointer[1]);
		break;
	    }
	    fprintf(NetTrace, " %d %d (%d)",
		pointer[1], pointer[2],
		(int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
	    if (length == 4) {
		fprintf(NetTrace, " ?%d?", pointer[3]);
		break;
	    }
	    fprintf(NetTrace, " %d %d (%d)",
		pointer[3], pointer[4],
		(int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4])));
	    for (i = 5; i < length; i++)
		fprintf(NetTrace, " ?%d?", pointer[i]);
	    break;

#ifdef	AUTHENTICATION
	case TELOPT_AUTHENTICATION:
	    fprintf(NetTrace, "AUTHENTICATION");
	    if (length < 2) {
		fprintf(NetTrace, " (empty suboption??\?)");
		break;
	    }
	    switch (pointer[1]) {
	    case TELQUAL_REPLY:
	    case TELQUAL_IS:
		fprintf(NetTrace, " %s ", (pointer[1] == TELQUAL_IS) ?
							"IS" : "REPLY");
		if (AUTHTYPE_NAME_OK(pointer[2]))
		    fprintf(NetTrace, "%s ", AUTHTYPE_NAME(pointer[2]));
		else
		    fprintf(NetTrace, "%d ", pointer[2]);
		if (length < 3) {
		    fprintf(NetTrace, "(partial suboption??\?)");
		    break;
		}
		fprintf(NetTrace, "%s|%s",
			((pointer[3] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
			"CLIENT" : "SERVER",
			((pointer[3] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
			"MUTUAL" : "ONE-WAY");

		auth_printsub(&pointer[1], length - 1, buf, sizeof(buf));
		fprintf(NetTrace, "%s", buf);
		break;

	    case TELQUAL_SEND:
		i = 2;
		fprintf(NetTrace, " SEND ");
		while (i < length) {
		    if (AUTHTYPE_NAME_OK(pointer[i]))
			fprintf(NetTrace, "%s ", AUTHTYPE_NAME(pointer[i]));
		    else
			fprintf(NetTrace, "%d ", pointer[i]);
		    if (++i >= length) {
			fprintf(NetTrace, "(partial suboption??\?)");
			break;
		    }
		    fprintf(NetTrace, "%s|%s ",
			((pointer[i] & AUTH_WHO_MASK) == AUTH_WHO_CLIENT) ?
							"CLIENT" : "SERVER",
			((pointer[i] & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) ?
							"MUTUAL" : "ONE-WAY");
		    ++i;
		}
		break;

	    case TELQUAL_NAME:
		i = 2;
		fprintf(NetTrace, " NAME \"");
		while (i < length)
		    putc(pointer[i++], NetTrace);
		putc('"', NetTrace);
		break;

	    default:
		    for (i = 2; i < length; i++)
			fprintf(NetTrace, " ?%d?", pointer[i]);
		    break;
	    }
	    break;
#endif

#ifdef	ENCRYPTION
	case TELOPT_ENCRYPT:
	    fprintf(NetTrace, "ENCRYPT");
	    if (length < 2) {
		fprintf(NetTrace, " (empty suboption??\?)");
		break;
	    }
	    switch (pointer[1]) {
	    case ENCRYPT_START:
		fprintf(NetTrace, " START");
		break;

	    case ENCRYPT_END:
		fprintf(NetTrace, " END");
		break;

	    case ENCRYPT_REQSTART:
		fprintf(NetTrace, " REQUEST-START");
		break;

	    case ENCRYPT_REQEND:
		fprintf(NetTrace, " REQUEST-END");
		break;

	    case ENCRYPT_IS:
	    case ENCRYPT_REPLY:
		fprintf(NetTrace, " %s ", (pointer[1] == ENCRYPT_IS) ?
							"IS" : "REPLY");
		if (length < 3) {
		    fprintf(NetTrace, " (partial suboption??\?)");
		    break;
		}
		if (ENCTYPE_NAME_OK(pointer[2]))
		    fprintf(NetTrace, "%s ", ENCTYPE_NAME(pointer[2]));
		else
		    fprintf(NetTrace, " %d (unknown)", pointer[2]);

		encrypt_printsub(&pointer[1], length - 1, buf, sizeof(buf));
		fprintf(NetTrace, "%s", buf);
		break;

	    case ENCRYPT_SUPPORT:
		i = 2;
		fprintf(NetTrace, " SUPPORT ");
		while (i < length) {
		    if (ENCTYPE_NAME_OK(pointer[i]))
			fprintf(NetTrace, "%s ", ENCTYPE_NAME(pointer[i]));
		    else
			fprintf(NetTrace, "%d ", pointer[i]);
		    i++;
		}
		break;

	    case ENCRYPT_ENC_KEYID:
		fprintf(NetTrace, " ENC_KEYID ");
		goto encommon;

	    case ENCRYPT_DEC_KEYID:
		fprintf(NetTrace, " DEC_KEYID ");
		goto encommon;

	    default:
		fprintf(NetTrace, " %d (unknown)", pointer[1]);
	    encommon:
		for (i = 2; i < length; i++)
		    fprintf(NetTrace, " %d", pointer[i]);
		break;
	    }
	    break;
#endif	/* ENCRYPTION */

	case TELOPT_LINEMODE:
	    fprintf(NetTrace, "LINEMODE ");
	    if (length < 2) {
		fprintf(NetTrace, " (empty suboption??\?)");
		break;
	    }
	    switch (pointer[1]) {
	    case WILL:
		fprintf(NetTrace, "WILL ");
		goto common;
	    case WONT:
		fprintf(NetTrace, "WONT ");
		goto common;
	    case DO:
		fprintf(NetTrace, "DO ");
		goto common;
	    case DONT:
		fprintf(NetTrace, "DONT ");
	    common:
		if (length < 3) {
		    fprintf(NetTrace, "(no option??\?)");
		    break;
		}
		switch (pointer[2]) {
		case LM_FORWARDMASK:
		    fprintf(NetTrace, "Forward Mask");
		    for (i = 3; i < length; i++)
			fprintf(NetTrace, " %x", pointer[i]);
		    break;
		default:
		    fprintf(NetTrace, "%d (unknown)", pointer[2]);
		    for (i = 3; i < length; i++)
			fprintf(NetTrace, " %d", pointer[i]);
		    break;
		}
		break;

	    case LM_SLC:
		fprintf(NetTrace, "SLC");
		for (i = 2; i < length - 2; i += 3) {
		    if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
			fprintf(NetTrace, " %s", SLC_NAME(pointer[i+SLC_FUNC]));
		    else
			fprintf(NetTrace, " %d", pointer[i+SLC_FUNC]);
		    switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
		    case SLC_NOSUPPORT:
			fprintf(NetTrace, " NOSUPPORT"); break;
		    case SLC_CANTCHANGE:
			fprintf(NetTrace, " CANTCHANGE"); break;
		    case SLC_VARIABLE:
			fprintf(NetTrace, " VARIABLE"); break;
		    case SLC_DEFAULT:
			fprintf(NetTrace, " DEFAULT"); break;
		    }
		    fprintf(NetTrace, "%s%s%s",
			pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
			pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
			pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
		    if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
						SLC_FLUSHOUT| SLC_LEVELBITS))
			fprintf(NetTrace, "(0x%x)", pointer[i+SLC_FLAGS]);
		    fprintf(NetTrace, " %d;", pointer[i+SLC_VALUE]);
		    if ((pointer[i+SLC_VALUE] == IAC) &&
			(pointer[i+SLC_VALUE+1] == IAC))
				i++;
		}
		for (; i < length; i++)
		    fprintf(NetTrace, " ?%d?", pointer[i]);
		break;

	    case LM_MODE:
		fprintf(NetTrace, "MODE ");
		if (length < 3) {
		    fprintf(NetTrace, "(no mode??\?)");
		    break;
		}
		{
		    char tbuf[64];
		    snprintf(tbuf, sizeof(tbuf), "%s%s%s%s%s",
			pointer[2]&MODE_EDIT ? "|EDIT" : "",
			pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
			pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
			pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
			pointer[2]&MODE_ACK ? "|ACK" : "");
		    fprintf(NetTrace, "%s", tbuf[1] ? &tbuf[1] : "0");
		}
		if (pointer[2]&~(MODE_MASK))
		    fprintf(NetTrace, " (0x%x)", pointer[2]);
		for (i = 3; i < length; i++)
		    fprintf(NetTrace, " ?0x%x?", pointer[i]);
		break;
	    default:
		fprintf(NetTrace, "%d (unknown)", pointer[1]);
		for (i = 2; i < length; i++)
		    fprintf(NetTrace, " %d", pointer[i]);
	    }
	    break;

	case TELOPT_STATUS: {
	    const char *cp;
	    int j, k;

	    fprintf(NetTrace, "STATUS");

	    switch (pointer[1]) {
	    default:
		if (pointer[1] == TELQUAL_SEND)
		    fprintf(NetTrace, " SEND");
		else
		    fprintf(NetTrace, " %d (unknown)", pointer[1]);
		for (i = 2; i < length; i++)
		    fprintf(NetTrace, " ?%d?", pointer[i]);
		break;
	    case TELQUAL_IS:
		if (--want_status_response < 0)
		    want_status_response = 0;
		if (NetTrace == stdout)
		    fprintf(NetTrace, " IS\r\n");
		else
		    fprintf(NetTrace, " IS\n");

		for (i = 2; i < length; i++) {
		    switch(pointer[i]) {
		    case DO:	cp = "DO"; goto common2;
		    case DONT:	cp = "DONT"; goto common2;
		    case WILL:	cp = "WILL"; goto common2;
		    case WONT:	cp = "WONT"; goto common2;
		    common2:
			i++;
			if (TELOPT_OK((int)pointer[i]))
			    fprintf(NetTrace, " %s %s", cp, TELOPT(pointer[i]));
			else
			    fprintf(NetTrace, " %s %d", cp, pointer[i]);

			if (NetTrace == stdout)
			    fprintf(NetTrace, "\r\n");
			else
			    fprintf(NetTrace, "\n");
			break;

		    case SB:
			fprintf(NetTrace, " SB ");
			i++;
			j = k = i;
			while (j < length) {
			    if (pointer[j] == SE) {
				if (j+1 == length)
				    break;
				if (pointer[j+1] == SE)
				    j++;
				else
				    break;
			    }
			    pointer[k++] = pointer[j++];
			}
			printsub(0, &pointer[i], k - i);
			if (i < length) {
			    fprintf(NetTrace, " SE");
			    i = j;
			} else
			    i = j - 1;

			if (NetTrace == stdout)
			    fprintf(NetTrace, "\r\n");
			else
			    fprintf(NetTrace, "\n");

			break;

		    default:
			fprintf(NetTrace, " %d", pointer[i]);
			break;
		    }
		}
		break;
	    }
	    break;
	  }

	case TELOPT_XDISPLOC:
	    fprintf(NetTrace, "X-DISPLAY-LOCATION ");
	    switch (pointer[1]) {
	    case TELQUAL_IS:
		fprintf(NetTrace, "IS \"%.*s\"", length-2, (char *)pointer+2);
		break;
	    case TELQUAL_SEND:
		fprintf(NetTrace, "SEND");
		break;
	    default:
		fprintf(NetTrace, "- unknown qualifier %d (0x%x).",
				pointer[1], pointer[1]);
	    }
	    break;

	case TELOPT_NEW_ENVIRON:
	    fprintf(NetTrace, "NEW-ENVIRON ");
#ifdef	OLD_ENVIRON
	    goto env_common1;
	case TELOPT_OLD_ENVIRON:
	    fprintf(NetTrace, "OLD-ENVIRON");
	env_common1:
#endif
	    switch (pointer[1]) {
	    case TELQUAL_IS:
		fprintf(NetTrace, "IS ");
		goto env_common;
	    case TELQUAL_SEND:
		fprintf(NetTrace, "SEND ");
		goto env_common;
	    case TELQUAL_INFO:
		fprintf(NetTrace, "INFO ");
	    env_common:
		{
		    int noquote = 2;
#if defined(ENV_HACK) && defined(OLD_ENVIRON)
		    extern int old_env_var, old_env_value;
#endif
		    for (i = 2; i < length; i++ ) {
			switch (pointer[i]) {
			case NEW_ENV_VALUE:
#ifdef OLD_ENVIRON
		     /*	case NEW_ENV_OVAR: */
			    if (pointer[0] == TELOPT_OLD_ENVIRON) {
# ifdef	ENV_HACK
				if (old_env_var == OLD_ENV_VALUE)
				    fprintf(NetTrace, "\" (VALUE) " + noquote);
				else
# endif
				    fprintf(NetTrace, "\" VAR " + noquote);
			    } else
#endif /* OLD_ENVIRON */
				fprintf(NetTrace, "%s", "\" VALUE " + noquote);
			    noquote = 2;
			    break;

			case NEW_ENV_VAR:
#ifdef OLD_ENVIRON
		     /* case OLD_ENV_VALUE: */
			    if (pointer[0] == TELOPT_OLD_ENVIRON) {
# ifdef	ENV_HACK
				if (old_env_value == OLD_ENV_VAR)
				    fprintf(NetTrace, "\" (VAR) " + noquote);
				else
# endif
				    fprintf(NetTrace, "\" VALUE " + noquote);
			    } else
#endif /* OLD_ENVIRON */
				fprintf(NetTrace, "%s", "\" VAR " + noquote);
			    noquote = 2;
			    break;

			case ENV_ESC:
			    fprintf(NetTrace, "%s", "\" ESC " + noquote);
			    noquote = 2;
			    break;

			case ENV_USERVAR:
			    fprintf(NetTrace, "%s", "\" USERVAR " + noquote);
			    noquote = 2;
			    break;

			default:
			    if (isprint(pointer[i]) && pointer[i] != '"') {
				if (noquote) {
				    putc('"', NetTrace);
				    noquote = 0;
				}
				putc(pointer[i], NetTrace);
			    } else {
				fprintf(NetTrace, "\" %03o " + noquote,
							pointer[i]);
				noquote = 2;
			    }
			    break;
			}
		    }
		    if (!noquote)
			putc('"', NetTrace);
		    break;
		}
	    }
	    break;

	default:
	    if (TELOPT_OK(pointer[0]))
		fprintf(NetTrace, "%s (unknown)", TELOPT(pointer[0]));
	    else
		fprintf(NetTrace, "%d (unknown)", pointer[0]);
	    for (i = 1; i < length; i++)
		fprintf(NetTrace, " %d", pointer[i]);
	    break;
	}
	if (direction) {
	    if (NetTrace == stdout)
		fprintf(NetTrace, "\r\n");
	    else
		fprintf(NetTrace, "\n");
	}
	if (NetTrace == stdout)
	    fflush(NetTrace);
    }
}

/* EmptyTerminal - called to make sure that the terminal buffer is empty.
 *			Note that we consider the buffer to run all the
 *			way to the kernel (thus the select).
 */

static void
EmptyTerminal(void)
{
    fd_set	o;

    FD_ZERO(&o);

    if (TTYBYTES() == 0) {
	FD_SET(tout, &o);
	(void) select(tout+1, (fd_set *) 0, &o, (fd_set *) 0,
			(struct timeval *) 0);	/* wait for TTLOWAT */
    } else {
	while (TTYBYTES()) {
	    (void) ttyflush(0);
	    FD_SET(tout, &o);
	    (void) select(tout+1, (fd_set *) 0, &o, (fd_set *) 0,
				(struct timeval *) 0);	/* wait for TTLOWAT */
	}
    }
}

static void
SetForExit(void)
{
    setconnmode(0);
    do {
	(void)telrcv();			/* Process any incoming data */
	EmptyTerminal();
    } while (ring_full_count(&netiring));	/* While there is any */
    setcommandmode();
    fflush(stdout);
    fflush(stderr);
    setconnmode(0);
    EmptyTerminal();			/* Flush the path to the tty */
    setcommandmode();
}

void
Exit(int returnCode)
{
    SetForExit();
    exit(returnCode);
}

void
ExitString(const char *string, int returnCode)
{
    SetForExit();
    fwrite(string, 1, strlen(string), stderr);
    exit(returnCode);
}