inetutils/telnet/tn3270.c

/*
  Copyright (C) 1995-2025 Free Software Foundation, Inc.

  This file is part of GNU Inetutils.

  GNU Inetutils 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 3 of the License, or (at
  your option) any later version.

  GNU Inetutils 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, see `http://www.gnu.org/licenses/'. */

/*
 * 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.
 */

#include <config.h>

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

#include "general.h"

#include "defines.h"
#include "ring.h"
#include "externs.h"

#if defined TN3270

# include "../ctlr/screen.h"
# include "../general/globals.h"

# include "../sys_curses/telextrn.h"
# include "../ctlr/externs.h"

# if defined unix || defined __unix || defined __unix__
int HaveInput,			/* There is input available to scan */
  cursesdata,			/* Do we dump curses data? */
  sigiocount;			/* Number of times we got a SIGIO */

char tline[200];
char *transcom = 0;		/* transparent mode command (default: none) */
# endif/* unix || __unix || __unix__ */

char Ibuf[8 * BUFSIZ], *Ifrontp, *Ibackp;

static char sb_terminal[] = { IAC, SB,
  TELOPT_TTYPE, TELQUAL_IS,
  'I', 'B', 'M', '-', '3', '2', '7', '8', '-', '2',
  IAC, SE
};

# define SBTERMMODEL	13

static int Sent3270TerminalType;	/* Have we said we are a 3270? */

#endif /* defined(TN3270) */


void
init_3270 (void)
{
#if defined TN3270
# if defined unix || defined __unix || defined __unix__
  HaveInput = 0;
  sigiocount = 0;
# endif/* unix || __unix || __unix__ */
  Sent3270TerminalType = 0;
  Ifrontp = Ibackp = Ibuf;
  init_ctlr ();			/* Initialize some things */
  init_keyboard ();
  init_screen ();
  init_system ();
#endif /* defined(TN3270) */
}


#if defined TN3270

/*
 * DataToNetwork - queue up some data to go to network.  If "done" is set,
 * then when last byte is queued, we add on an IAC EOR sequence (so,
 * don't call us with "done" until you want that done...)
 *
 * We actually do send all the data to the network buffer, since our
 * only client needs for us to do that.
 */

/*char *buffer; where the data is */
/* int  count;	 how much to send */
/* int		  done;	 is this the last of a logical block */
int
DataToNetwork (char *buffer, int count, int done)
{
  int loop, c;
  int origCount;

  origCount = count;

  while (count)
    {
      /* If not enough room for EORs, IACs, etc., wait */
      if (NETROOM () < 6)
	{
	  fd_set o;

	  FD_ZERO (&o);
	  netflush ();
	  while (NETROOM () < 6)
	    {
	      FD_SET (net, &o);
	      select (net + 1, (fd_set *) 0, &o, (fd_set *) 0,
		      (struct timeval *) 0);
	      netflush ();
	    }
	}
      c = ring_empty_count (&netoring);
      if (c > count)
	{
	  c = count;
	}
      loop = c;
      while (loop)
	{
	  if (((unsigned char) *buffer) == IAC)
	    {
	      break;
	    }
	  buffer++;
	  loop--;
	}
      if ((c = c - loop))
	{
	  ring_supply_data (&netoring, buffer - c, c);
	  count -= c;
	}
      if (loop)
	{
	  NET2ADD (IAC, IAC);
	  count--;
	  buffer++;
	}
    }

  if (done)
    {
      NET2ADD (IAC, EOR);
      netflush ();		/* try to move along as quickly as ... */
    }
  return (origCount - count);
}


# if defined unix || defined __unix || defined __unix__
void
inputAvailable (int signo)
{
  HaveInput = 1;
  sigiocount++;
}
# endif/* unix || __unix || __unix__ */

void
outputPurge (void)
{
  ttyflush (1);
}


/*
 * The following routines are places where the various tn3270
 * routines make calls into telnet.c.
 */

/*
 * DataToTerminal - queue up some data to go to terminal.
 *
 * Note: there are people who call us and depend on our processing
 * *all* the data at one time (thus the select).
 */

/* char *buffer;where the data is */
/* int	count;	 how much to send */
int
DataToTerminal (char *buffer, int count)
{
  int c;
  int origCount;

  origCount = count;

  while (count)
    {
      if (TTYROOM () == 0)
	{
# if defined unix || defined __unix || defined __unix__
	  fd_set o;

	  FD_ZERO (&o);
# endif/* unix || __unix || __unix__ */
	  ttyflush (0);
	  while (TTYROOM () == 0)
	    {
# if defined unix || defined __unix || defined __unix__
	      FD_SET (tout, &o);
	      select (tout + 1, (fd_set *) 0, &o, (fd_set *) 0,
		      (struct timeval *) 0);
# endif/* unix || __unix || __unix__ */
	      ttyflush (0);
	    }
	}
      c = TTYROOM ();
      if (c > count)
	{
	  c = count;
	}
      ring_supply_data (&ttyoring, buffer, c);
      count -= c;
      buffer += c;
    }
  return (origCount);
}


/*
 * Push3270 - Try to send data along the 3270 output (to screen) direction.
 */

int
Push3270 (void)
{
  int save = ring_full_count (&netiring);

  if (save)
    {
      if (Ifrontp + save > Ibuf + sizeof Ibuf)
	{
	  if (Ibackp != Ibuf)
	    {
	      memmove (Ibuf, Ibackp, Ifrontp - Ibackp);
	      Ifrontp -= (Ibackp - Ibuf);
	      Ibackp = Ibuf;
	    }
	}
      if (Ifrontp + save < Ibuf + sizeof Ibuf)
	{
	  telrcv ();
	}
    }
  return save != ring_full_count (&netiring);
}


/*
 * Finish3270 - get the last dregs of 3270 data out to the terminal
 *		before quitting.
 */

void
Finish3270 (void)
{
  while (Push3270 () || !DoTerminalOutput ())
    {
# if defined unix || defined __unix || defined __unix__
      HaveInput = 0;
# endif/* unix || __unix || __unix__ */
      ;
    }
}


/* StringToTerminal - output a null terminated string to the terminal */

void
StringToTerminal (char *s)
{
  int count;

  count = strlen (s);
  if (count)
    {
      DataToTerminal (s, count);	/* we know it always goes... */
    }
}


# if   !defined NOT43 || defined PUTCHAR
/* _putchar - output a single character to the terminal.  This name is so that
 *	curses(3x) can call us to send out data.
 */

void
_putchar (char c)
{
#  if defined sun		/* SunOS 4.0 bug */
  c &= 0x7f;
#  endif
  /* defined(sun) */
  if (cursesdata)
    {
      Dump ('>', &c, 1);
    }
  if (!TTYROOM ())
    {
      DataToTerminal (&c, 1);
    }
  else
    {
      TTYADD (c);
    }
}
# endif/* ((!defined(NOT43)) || defined(PUTCHAR)) */

void
SetIn3270 (void)
{
  if (Sent3270TerminalType && my_want_state_is_will (TELOPT_BINARY)
      && my_want_state_is_do (TELOPT_BINARY) && !donebinarytoggle)
    {
      if (!In3270)
	{
	  In3270 = 1;
	  Init3270 ();		/* Initialize 3270 functions */
	  /* initialize terminal key mapping */
	  InitTerminal ();	/* Start terminal going */
	  setconnmode (0);
	}
    }
  else
    {
      if (In3270)
	{
	  StopScreen (1);
	  In3270 = 0;
	  Stop3270 ();		/* Tell 3270 we aren't here anymore */
	  setconnmode (0);
	}
    }
}

/*
 * tn3270_ttype()
 *
 *	Send a response to a terminal type negotiation.
 *
 *	Return '0' if no more responses to send; '1' if a response sent.
 */

int
tn3270_ttype (void)
{
  /*
   * Try to send a 3270 type terminal name.  Decide which one based
   * on the format of our screen, and (in the future) color
   * capaiblities.
   */
  InitTerminal ();		/* Sets MaxNumberColumns, MaxNumberLines */
  if ((MaxNumberLines >= 24) && (MaxNumberColumns >= 80))
    {
      Sent3270TerminalType = 1;
      if ((MaxNumberLines >= 27) && (MaxNumberColumns >= 132))
	{
	  MaxNumberLines = 27;
	  MaxNumberColumns = 132;
	  sb_terminal[SBTERMMODEL] = '5';
	}
      else if (MaxNumberLines >= 43)
	{
	  MaxNumberLines = 43;
	  MaxNumberColumns = 80;
	  sb_terminal[SBTERMMODEL] = '4';
	}
      else if (MaxNumberLines >= 32)
	{
	  MaxNumberLines = 32;
	  MaxNumberColumns = 80;
	  sb_terminal[SBTERMMODEL] = '3';
	}
      else
	{
	  MaxNumberLines = 24;
	  MaxNumberColumns = 80;
	  sb_terminal[SBTERMMODEL] = '2';
	}
      NumberLines = 24;		/* before we start out... */
      NumberColumns = 80;
      ScreenSize = NumberLines * NumberColumns;
      if ((MaxNumberLines * MaxNumberColumns) > MAXSCREENSIZE)
	{
	  ExitString ("Programming error:  MAXSCREENSIZE too small.\n", 1);
	}
      printsub ('>', sb_terminal + 2, sizeof sb_terminal - 2);
      ring_supply_data (&netoring, sb_terminal, sizeof sb_terminal);
      return 1;
    }
  else
    {
      return 0;
    }
}

# if defined unix || defined __unix || defined __unix__
int
settranscom (int argc, char *argv[])
{
  int i;

  if (argc == 1 && transcom)
    {
      transcom = 0;
    }
  if (argc == 1)
    {
      return 1;
    }
  transcom = tline;
  strcpy (transcom, argv[1]);
  for (i = 2; i < argc; ++i)
    {
      strcat (transcom, " ");
      strcat (transcom, argv[i]);
    }
  return 1;
}
# endif/* unix || __unix || __unix__ */

#endif /* defined(TN3270) */