/*
 * Copyright 1994-2002 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * usr/src/cmd/cmd-inet/usr.bin/telnet/terminal.c
 */

/*
 * Copyright (c) 1988, 1990, 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 */

#ifndef lint
static char sccsid[] = "@(#)terminal.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

#include <arpa/telnet.h>
#include <sys/types.h>
#include <errno.h>

#include "ring.h"

#include "externs.h"
#include "types.h"

Ring	ttyoring;
Ring	ttyiring;
static unsigned char ttyobuf[2*BUFSIZ];
static unsigned char ttyibuf[BUFSIZ];

int termdata;			/* Debugging flag */

#ifdef	USE_TERMIO
cc_t termAytChar;
#else
cc_t termForw2Char;
cc_t termAytChar;
#endif

/*
 * initialize the terminal data structures.
 */

    void
init_terminal()
{
	if (ring_init(&ttyoring, ttyobuf, sizeof (ttyobuf)) != 1) {
		exit(1);
	}
	if (ring_init(&ttyiring, ttyibuf, sizeof (ttyibuf)) != 1) {
		exit(1);
	}
	autoflush = 1;
}


/*
 *		Send as much data as possible to the terminal.
 *
 *		Return value:
 *			-2: Error occurred other than EWOULDBLOCK; see
 *			    'errno' for specifics
 *			-1: No useful work done, although data was waiting.
 *			    This may be due to EWOULDBLOCK error.
 *			 0: No data was waiting, so nothing was done.
 *			 1: All waiting data was written out.
 *			 n: Part of data was written.  'n' is the number
 *			    of bytes remaining which were not written.
 */

int
ttyflush(drop)
	int drop;
{
	register int n, n0, n1;

	n0 = ring_full_count(&ttyoring);
	if ((n1 = n = ring_full_consecutive(&ttyoring)) > 0) {
		if (drop) {
			TerminalFlushOutput();
			/* we leave 'n' alone! */
		} else {
			n = TerminalWrite((char *)ttyoring.consume, n);
			if (n == -1 && errno != EWOULDBLOCK)
				return (-2);
		}
	}
	if (n > 0) {
		if (termdata && n) {
			Dump('>', ttyoring.consume, n);
		}
		/*
		 * If we wrote everything, and the full count is
		 * larger than what we wrote, then write the
		 * rest of the buffer.
		 */
		if (n1 == n && n0 > n) {
			n1 = n0 - n;
			if (!drop) {
				n1 = TerminalWrite((char *)ttyoring.bottom, n1);
				if (n1 == -1) {
					if (errno != EWOULDBLOCK)
						return (-2);
					n1 = 0;
				}
			}
			n += n1;
		}
		ring_consumed(&ttyoring, n);
	}
	if (n < 0)
		return (-1);

	if (n == n0) {
		if (n0)
			return (-1);
		return (0);
	}
	return (n0 - n + 1);
}


/*
 * These routines decides on what the mode should be (based on the values
 * of various global variables).
 */


int
getconnmode()
{
	extern int linemode;
	int mode = 0;
#ifdef	KLUDGELINEMODE
	extern int kludgelinemode;
#endif

	if (my_want_state_is_dont(TELOPT_ECHO))
		mode |= MODE_ECHO;

	if (localflow)
		mode |= MODE_FLOW;

	if (my_want_state_is_will(TELOPT_BINARY))
		mode |= MODE_INBIN;

	if (my_want_state_is_do(TELOPT_BINARY))
		mode |= MODE_OUTBIN;

#ifdef	KLUDGELINEMODE
	if (kludgelinemode) {
		if (my_want_state_is_dont(TELOPT_SGA)) {
			mode |= (MODE_TRAPSIG|MODE_EDIT);
			if (dontlecho &&
			    (clocks.echotoggle > clocks.modenegotiated)) {
				mode &= ~MODE_ECHO;
			}
		}
		return (mode);
	}
#endif
	if (my_want_state_is_will(TELOPT_LINEMODE))
		mode |= linemode;
	return (mode);
}

void
setconnmode(force)
	int force;
{
	static int enc_passwd = 0;
	register int newmode;

	newmode = getconnmode()|(force?MODE_FORCE:0);

	TerminalNewMode(newmode);

	if ((newmode & (MODE_ECHO|MODE_EDIT)) == MODE_EDIT) {
		if (my_want_state_is_will(TELOPT_ENCRYPT) &&
		    (enc_passwd == 0) && !encrypt_output) {
			encrypt_request_start(0, 0);
			enc_passwd = 1;
		}
	} else {
		if (enc_passwd) {
			encrypt_request_end();
			enc_passwd = 0;
		}
	}
}


    void
setcommandmode()
{
	TerminalNewMode(-1);
}