/*      $NetBSD: terminal.c,v 1.16 2018/12/14 06:08:18 maya Exp $       */

/*
* 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. 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.
*/

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)terminal.c  8.2 (Berkeley) 2/16/95";
#else
__RCSID("$NetBSD: terminal.c,v 1.16 2018/12/14 06:08:18 maya Exp $");
#endif
#endif /* not lint */

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

#include "ring.h"

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

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

Ring            ttyoring, ttyiring;
unsigned char   ttyobuf[2*BUFSIZ], ttyibuf[BUFSIZ];
char line[] = { '\0' };

int termdata;                   /* Debugging flag */

/*
* initialize the terminal data structures.
*/

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


/*
*              Send as much data as possible to the terminal, else exits if
*              it encounters a permanent failure when writing to the tty.
*
*              Return value:
*                      -1: No useful work done, data waiting to go out.
*                       0: No data was waiting, so nothing was done.
*                       1: All waiting data was written out.
*                       n: All data - n was written out.
*/


int
ttyflush(int drop)
{
   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(ttyoring.consume, n);
       }
   }
   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(ttyoring.bottom, n1);
               if (n1 > 0)
                       n += n1;
       }
       ring_consumed(&ttyoring, n);
   }
   if (n < 0) {
       if (errno == EAGAIN || errno == EINTR) {
           return -1;
       } else {
           ring_consumed(&ttyoring, ring_full_count(&ttyoring));
           setconnmode(0);
           setcommandmode();
           NetClose(net);
           fprintf(stderr, "Connection closed by foreign host.\n");
           exit(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(void)
{
   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 (his_want_state_is_will(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(int force)
{
#ifdef  ENCRYPTION
   static int enc_passwd = 0;
#endif
   int newmode;

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

   TerminalNewMode(newmode);

#ifdef  ENCRYPTION
   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;
       }
   }
#endif  /* ENCRYPTION */
}


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