2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
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6 * modification, are permitted provided that the following conditions
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13 * 3. All advertising materials mentioning features or use of this software
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15 * This product includes software developed by the University of
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34 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD: src/libexec/telnetd/termstat.c,v 1.9.2.4 2002/04/13 11:07:12 markm Exp $");
39 static const char sccsid[] = "@(#)termstat.c 8.2 (Berkeley) 5/30/95";
48 int def_tspeed = -1, def_rspeed = -1;
50 int def_row = 0, def_col = 0;
53 static int _terminit = 0;
60 * This function handles all management of linemode.
62 * Linemode allows the client to do the local editing of data
63 * and send only complete lines to the server. Linemode state is
64 * based on the state of the pty driver. If the pty is set for
65 * external processing, then we can use linemode. Further, if we
66 * can use real linemode, then we can look at the edit control bits
67 * in the pty to determine what editing the client should do.
69 * Linemode support uses the following state flags to keep track of
70 * current and desired linemode state.
71 * alwayslinemode : true if -l was specified on the telnetd
72 * command line. It means to have linemode on as much as
75 * lmodetype: signifies whether the client can
76 * handle real linemode, or if use of kludgeomatic linemode
77 * is preferred. It will be set to one of the following:
78 * REAL_LINEMODE : use linemode option
79 * NO_KLUDGE : don't initiate kludge linemode.
80 * KLUDGE_LINEMODE : use kludge linemode
81 * NO_LINEMODE : client is ignorant of linemode
83 * linemode, uselinemode : linemode is true if linemode
84 * is currently on, uselinemode is the state that we wish
85 * to be in. If another function wishes to turn linemode
86 * on or off, it sets or clears uselinemode.
88 * editmode, useeditmode : like linemode/uselinemode, but
89 * these contain the edit mode states (edit and trapsig).
91 * The state variables correspond to some of the state information
94 * In real linemode, this corresponds to whether the pty
95 * expects external processing of incoming data.
96 * In kludge linemode, this more closely corresponds to the
97 * whether normal processing is on or not. (ICANON in
98 * system V, or COOKED mode in BSD.)
99 * If the -l option was specified (alwayslinemode), then
100 * an attempt is made to force external processing on at
103 * The following heuristics are applied to determine linemode
104 * handling within the server.
105 * 1) Early on in starting up the server, an attempt is made
106 * to negotiate the linemode option. If this succeeds
107 * then lmodetype is set to REAL_LINEMODE and all linemode
108 * processing occurs in the context of the linemode option.
109 * 2) If the attempt to negotiate the linemode option failed,
110 * and the "-k" (don't initiate kludge linemode) isn't set,
111 * then we try to use kludge linemode. We test for this
112 * capability by sending "do Timing Mark". If a positive
113 * response comes back, then we assume that the client
114 * understands kludge linemode (ech!) and the
115 * lmodetype flag is set to KLUDGE_LINEMODE.
116 * 3) Otherwise, linemode is not supported at all and
117 * lmodetype remains set to NO_LINEMODE (which happens
118 * to be 0 for convenience).
119 * 4) At any time a command arrives that implies a higher
120 * state of linemode support in the client, we move to that
123 * A short explanation of kludge linemode is in order here.
124 * 1) The heuristic to determine support for kludge linemode
125 * is to send a do timing mark. We assume that a client
126 * that supports timing marks also supports kludge linemode.
127 * A risky proposition at best.
128 * 2) Further negotiation of linemode is done by changing the
129 * the server's state regarding SGA. If server will SGA,
130 * then linemode is off, if server won't SGA, then linemode
136 int need_will_echo = 0;
139 * Check for changes to flow control if client supports it.
144 * Check linemode on/off state
146 uselinemode = tty_linemode();
149 * If alwayslinemode is on, and pty is changing to turn it off, then
150 * force linemode back on.
152 if (alwayslinemode && linemode && !uselinemode) {
154 tty_setlinemode(uselinemode);
159 * Check for state of BINARY options.
161 * We only need to do the binary dance if we are actually going
162 * to use linemode. As this confuses some telnet clients
163 * that don't support linemode, and doesn't gain us
164 * anything, we don't do it unless we're doing linemode.
165 * -Crh (henrich@msu.edu)
168 if (tty_isbinaryin()) {
169 if (his_want_state_is_wont(TELOPT_BINARY))
170 send_do(TELOPT_BINARY, 1);
172 if (his_want_state_is_will(TELOPT_BINARY))
173 send_dont(TELOPT_BINARY, 1);
176 if (tty_isbinaryout()) {
177 if (my_want_state_is_wont(TELOPT_BINARY))
178 send_will(TELOPT_BINARY, 1);
180 if (my_want_state_is_will(TELOPT_BINARY))
181 send_wont(TELOPT_BINARY, 1);
187 * Do echo mode handling as soon as we know what the
188 * linemode is going to be.
189 * If the pty has echo turned off, then tell the client that
190 * the server will echo. If echo is on, then the server
191 * will echo if in character mode, but in linemode the
192 * client should do local echoing. The state machine will
193 * not send anything if it is unnecessary, so don't worry
196 * If we need to send the WILL ECHO (because echo is off),
197 * then delay that until after we have changed the MODE.
198 * This way, when the user is turning off both editing
199 * and echo, the client will get editing turned off first.
200 * This keeps the client from going into encryption mode
201 * and then right back out if it is doing auto-encryption
202 * when passwords are being typed.
206 send_wont(TELOPT_ECHO, 1);
209 #ifdef KLUDGELINEMODE
210 if (lmodetype == KLUDGE_OK)
211 lmodetype = KLUDGE_LINEMODE;
216 * If linemode is being turned off, send appropriate
217 * command and then we're all done.
219 if (!uselinemode && linemode) {
220 # ifdef KLUDGELINEMODE
221 if (lmodetype == REAL_LINEMODE) {
222 # endif /* KLUDGELINEMODE */
223 send_dont(TELOPT_LINEMODE, 1);
224 # ifdef KLUDGELINEMODE
225 } else if (lmodetype == KLUDGE_LINEMODE)
226 send_will(TELOPT_SGA, 1);
227 # endif /* KLUDGELINEMODE */
228 send_will(TELOPT_ECHO, 1);
229 linemode = uselinemode;
233 # ifdef KLUDGELINEMODE
235 * If using real linemode check edit modes for possible later use.
236 * If we are in kludge linemode, do the SGA negotiation.
238 if (lmodetype == REAL_LINEMODE) {
239 # endif /* KLUDGELINEMODE */
242 useeditmode |= MODE_EDIT;
244 useeditmode |= MODE_TRAPSIG;
246 useeditmode |= MODE_SOFT_TAB;
248 useeditmode |= MODE_LIT_ECHO;
249 # ifdef KLUDGELINEMODE
250 } else if (lmodetype == KLUDGE_LINEMODE) {
251 if (tty_isediting() && uselinemode)
252 send_wont(TELOPT_SGA, 1);
254 send_will(TELOPT_SGA, 1);
256 # endif /* KLUDGELINEMODE */
259 * Negotiate linemode on if pty state has changed to turn it on.
260 * Send appropriate command and send along edit mode, then all done.
262 if (uselinemode && !linemode) {
263 # ifdef KLUDGELINEMODE
264 if (lmodetype == KLUDGE_LINEMODE) {
265 send_wont(TELOPT_SGA, 1);
266 } else if (lmodetype == REAL_LINEMODE) {
267 # endif /* KLUDGELINEMODE */
268 send_do(TELOPT_LINEMODE, 1);
269 /* send along edit modes */
270 output_data("%c%c%c%c%c%c%c", IAC, SB,
271 TELOPT_LINEMODE, LM_MODE, useeditmode,
273 editmode = useeditmode;
274 # ifdef KLUDGELINEMODE
276 # endif /* KLUDGELINEMODE */
277 linemode = uselinemode;
281 # ifdef KLUDGELINEMODE
283 * None of what follows is of any value if not using
286 if (lmodetype < REAL_LINEMODE)
288 # endif /* KLUDGELINEMODE */
290 if (linemode && his_state_is_will(TELOPT_LINEMODE)) {
292 * If edit mode changed, send edit mode.
294 if (useeditmode != editmode) {
296 * Send along appropriate edit mode mask.
298 output_data("%c%c%c%c%c%c%c", IAC, SB,
299 TELOPT_LINEMODE, LM_MODE, useeditmode,
301 editmode = useeditmode;
306 * Check for changes to special characters in use.
315 send_will(TELOPT_ECHO, 1);
317 * Some things should be deferred until after the pty state has
318 * been set by the local process. Do those things that have been
319 * deferred now. This only happens once.
321 if (_terminit == 0) {
330 } /* end of localstat */
331 #endif /* LINEMODE */
336 * Check for changes to flow control
341 if (his_state_is_will(TELOPT_LFLOW)) {
342 if (tty_flowmode() != flowmode) {
343 flowmode = tty_flowmode();
344 output_data("%c%c%c%c%c%c",
345 IAC, SB, TELOPT_LFLOW,
346 flowmode ? LFLOW_ON : LFLOW_OFF,
349 if (tty_restartany() != restartany) {
350 restartany = tty_restartany();
351 output_data("%c%c%c%c%c%c",
352 IAC, SB, TELOPT_LFLOW,
353 restartany ? LFLOW_RESTART_ANY
363 * Process linemode related requests from the client.
364 * Client can request a change to only one of linemode, editmode or slc's
365 * at a time, and if using kludge linemode, then only linemode may be
369 clientstat(int code, int parm1, int parm2)
373 * Get a copy of terminal characteristics.
378 * Process request from client. code tells what it is.
382 case TELOPT_LINEMODE:
384 * Don't do anything unless client is asking us to change
387 uselinemode = (parm1 == WILL);
388 if (uselinemode != linemode) {
389 # ifdef KLUDGELINEMODE
391 * If using kludge linemode, make sure that
392 * we can do what the client asks.
393 * We can not turn off linemode if alwayslinemode
394 * and the ICANON bit is set.
396 if (lmodetype == KLUDGE_LINEMODE) {
397 if (alwayslinemode && tty_isediting()) {
403 * Quit now if we can't do it.
405 if (uselinemode == linemode)
409 * If using real linemode and linemode is being
410 * turned on, send along the edit mode mask.
412 if (lmodetype == REAL_LINEMODE && uselinemode)
413 # else /* KLUDGELINEMODE */
415 # endif /* KLUDGELINEMODE */
419 useeditmode |= MODE_EDIT;
421 useeditmode |= MODE_TRAPSIG;
423 useeditmode |= MODE_SOFT_TAB;
425 useeditmode |= MODE_LIT_ECHO;
426 output_data("%c%c%c%c%c%c%c", IAC,
427 SB, TELOPT_LINEMODE, LM_MODE,
428 useeditmode, IAC, SE);
429 editmode = useeditmode;
433 tty_setlinemode(uselinemode);
435 linemode = uselinemode;
438 send_will(TELOPT_ECHO, 1);
447 * Client has sent along a mode mask. If it agrees with
448 * what we are currently doing, ignore it; if not, it could
449 * be viewed as a request to change. Note that the server
450 * will change to the modes in an ack if it is different from
451 * what we currently have, but we will not ack the ack.
453 useeditmode &= MODE_MASK;
454 ack = (useeditmode & MODE_ACK);
455 useeditmode &= ~MODE_ACK;
457 if ((changed = (useeditmode ^ editmode))) {
459 * This check is for a timing problem. If the
460 * state of the tty has changed (due to the user
461 * application) we need to process that info
462 * before we write in the state contained in the
463 * ack!!! This gets out the new MODE request,
464 * and when the ack to that command comes back
465 * we'll set it and be in the right mode.
469 if (changed & MODE_EDIT)
470 tty_setedit(useeditmode & MODE_EDIT);
472 if (changed & MODE_TRAPSIG)
473 tty_setsig(useeditmode & MODE_TRAPSIG);
475 if (changed & MODE_SOFT_TAB)
476 tty_setsofttab(useeditmode & MODE_SOFT_TAB);
478 if (changed & MODE_LIT_ECHO)
479 tty_setlitecho(useeditmode & MODE_LIT_ECHO);
484 output_data("%c%c%c%c%c%c%c", IAC,
485 SB, TELOPT_LINEMODE, LM_MODE,
486 useeditmode|MODE_ACK,
490 editmode = useeditmode;
495 } /* end of case LM_MODE */
496 #endif /* LINEMODE */
507 * Defer changing window size until after terminal is
512 #endif /* LINEMODE */
515 * Change window size as requested by client.
520 (void) ioctl(pty, TIOCSWINSZ, (char *)&ws);
522 #endif /* TIOCSWINSZ */
532 * Defer changing the terminal speed.
536 #endif /* LINEMODE */
538 * Change terminal speed as requested by client.
539 * We set the receive speed first, so that if we can't
540 * store separate receive and transmit speeds, the transmit
541 * speed will take precedence.
549 } /* end of case TELOPT_TSPEED */
554 } /* end of switch */
558 } /* end of clientstat */
564 * Some things should not be done until after the login process has started
565 * and all the pty modes are set to what they are supposed to be. This
566 * function is called when the pty state has been processed for the first time.
567 * It calls other functions that do things that were deferred in each module.
574 * local stuff that got deferred.
576 if (def_tspeed != -1) {
577 clientstat(TELOPT_TSPEED, def_tspeed, def_rspeed);
578 def_tspeed = def_rspeed = 0;
582 if (def_col || def_row) {
585 memset((char *)&ws, 0, sizeof(ws));
588 (void) ioctl(pty, TIOCSWINSZ, (char *)&ws);
593 * The only other module that currently defers anything.
597 } /* end of defer_terminit */
602 * Returns true if the pty state has been processed yet.
609 } /* end of terminit */
610 #endif /* LINEMODE */