xref: /csrg-svn/sys/kern/tty.c (revision 43377)
1 /*
2  * Copyright (c) 1982, 1986, 1990 Regents of the University of California.
3  * All rights reserved.  The Berkeley software License Agreement
4  * specifies the terms and conditions for redistribution.
5  *
6  *	@(#)tty.c	7.33 (Berkeley) 06/21/90
7  */
8 
9 #include "param.h"
10 #include "systm.h"
11 #include "user.h"
12 #include "ioctl.h"
13 #define TTYDEFCHARS
14 #include "tty.h"
15 #undef TTYDEFCHARS
16 #include "proc.h"
17 #include "file.h"
18 #include "conf.h"
19 #include "dkstat.h"
20 #include "uio.h"
21 #include "kernel.h"
22 #include "vnode.h"
23 #include "syslog.h"
24 
25 #include "machine/reg.h"
26 
27 /* symbolic sleep message strings */
28 char ttyin[] = "ttyin";
29 char ttyout[] = "ttyout";
30 char ttopen[] = "ttyopn";
31 char ttclos[] = "ttycls";
32 char ttybg[] = "ttybg";
33 char ttybuf[] = "ttybuf";
34 
35 /*
36  * Table giving parity for characters and indicating
37  * character classes to tty driver. The 8th bit
38  * indicates parity, the 7th bit indicates the character
39  * is an alphameric or underscore (for ALTWERASE), and the
40  * low 6 bits indicate delay type.  If the low 6 bits are 0
41  * then the character needs no special processing on output.
42  */
43 
44 char partab[] = {
45 	0001,0201,0201,0001,0201,0001,0001,0201,	/* nul - bel */
46 	0202,0004,0003,0201,0005,0206,0201,0001,	/* bs - si */
47 	0201,0001,0001,0201,0001,0201,0201,0001,	/* dle - etb */
48 	0001,0201,0201,0001,0201,0001,0001,0201,	/* can - us */
49 	0200,0000,0000,0200,0000,0200,0200,0000,	/* sp - ' */
50 	0000,0200,0200,0000,0200,0000,0000,0200,	/* ( - / */
51 	0100,0300,0300,0100,0300,0100,0100,0300,	/* 0 - 7 */
52 	0300,0100,0000,0200,0000,0200,0200,0000,	/* 8 - ? */
53 	0200,0100,0100,0300,0100,0300,0300,0100,	/* @ - G */
54 	0100,0300,0300,0100,0300,0100,0100,0300,	/* H - O */
55 	0100,0300,0300,0100,0300,0100,0100,0300,	/* P - W */
56 	0300,0100,0100,0200,0000,0200,0200,0300,	/* X - _ */
57 	0000,0300,0300,0100,0300,0100,0100,0300,	/* ` - g */
58 	0300,0100,0100,0300,0100,0300,0300,0100,	/* h - o */
59 	0300,0100,0100,0300,0100,0300,0300,0100,	/* p - w */
60 	0100,0300,0300,0000,0200,0000,0000,0201,	/* x - del */
61 	/*
62 	 * meta chars
63 	 */
64 	0001,0201,0201,0001,0201,0001,0001,0201,	/* nul - bel */
65 	0202,0004,0003,0201,0005,0206,0201,0001,	/* bs - si */
66 	0201,0001,0001,0201,0001,0201,0201,0001,	/* dle - etb */
67 	0001,0201,0201,0001,0201,0001,0001,0201,	/* can - us */
68 	0200,0000,0000,0200,0000,0200,0200,0000,	/* sp - ' */
69 	0000,0200,0200,0000,0200,0000,0000,0200,	/* ( - / */
70 	0100,0300,0300,0100,0300,0100,0100,0300,	/* 0 - 7 */
71 	0300,0100,0000,0200,0000,0200,0200,0000,	/* 8 - ? */
72 	0200,0100,0100,0300,0100,0300,0300,0100,	/* @ - G */
73 	0100,0300,0300,0100,0300,0100,0100,0300,	/* H - O */
74 	0100,0300,0300,0100,0300,0100,0100,0300,	/* P - W */
75 	0300,0100,0100,0200,0000,0200,0200,0300,	/* X - _ */
76 	0000,0300,0300,0100,0300,0100,0100,0300,	/* ` - g */
77 	0300,0100,0100,0300,0100,0300,0300,0100,	/* h - o */
78 	0300,0100,0100,0300,0100,0300,0300,0100,	/* p - w */
79 	0100,0300,0300,0000,0200,0000,0000,0201,	/* x - del */
80 };
81 
82 extern struct tty *constty;		/* temporary virtual console */
83 extern char partab[], maptab[];
84 
85 /*
86  * Is 'c' a line delimiter ("break" character)?
87  */
88 #define ttbreakc(c) ((c) == '\n' || ((c) == cc[VEOF] || \
89 	(c) == cc[VEOL] || (c) == cc[VEOL2]) && (c) != _POSIX_VDISABLE)
90 
91 ttychars(tp)
92 	struct tty *tp;
93 {
94 	bcopy(ttydefchars, tp->t_cc, sizeof(ttydefchars));
95 }
96 
97 /*
98  * Wait for output to drain, then flush input waiting.
99  */
100 ttywflush(tp)
101 	struct tty *tp;
102 {
103 	int error;
104 
105 	if ((error = ttywait(tp)) == 0)
106 		ttyflush(tp, FREAD);
107 	return (error);
108 }
109 
110 /*
111  * Wait for output to drain.
112  */
113 ttywait(tp)
114 	register struct tty *tp;
115 {
116 	int error = 0, s = spltty();
117 
118 	while ((tp->t_outq.c_cc || tp->t_state&TS_BUSY) &&
119 	    (tp->t_state&TS_CARR_ON || tp->t_cflag&CLOCAL) &&
120 	    tp->t_oproc) {
121 		(*tp->t_oproc)(tp);
122 		tp->t_state |= TS_ASLEEP;
123 		if (error = ttysleep(tp, (caddr_t)&tp->t_outq,
124 		    TTOPRI | PCATCH, ttyout, 0))
125 			break;
126 	}
127 	splx(s);
128 	return (error);
129 }
130 
131 /*
132  * Flush all TTY queues
133  */
134 ttyflush(tp, rw)
135 	register struct tty *tp;
136 {
137 	register s;
138 
139 	s = spltty();
140 	if (rw & FREAD) {
141 		while (getc(&tp->t_canq) >= 0)
142 			;
143 		ttwakeup(tp);
144 	}
145 	if (rw & FWRITE) {
146 		wakeup((caddr_t)&tp->t_outq); /* XXX? what about selwakeup? */
147 		tp->t_state &= ~TS_TTSTOP;
148 		(*cdevsw[major(tp->t_dev)].d_stop)(tp, rw);
149 		while (getc(&tp->t_outq) >= 0)
150 			;
151 	}
152 	if (rw & FREAD) {
153 		while (getc(&tp->t_rawq) >= 0)
154 			;
155 		tp->t_rocount = 0;
156 		tp->t_rocol = 0;
157 		tp->t_state &= ~TS_LOCAL;
158 	}
159 	splx(s);
160 }
161 
162 /*
163  * Send stop character on input overflow.
164  */
165 ttyblock(tp)
166 	register struct tty *tp;
167 {
168 	register x;
169 
170 	x = tp->t_rawq.c_cc + tp->t_canq.c_cc;
171 	if (tp->t_rawq.c_cc > TTYHOG) {
172 		ttyflush(tp, FREAD|FWRITE);
173 		tp->t_state &= ~TS_TBLOCK;
174 	}
175 	/*
176 	 * Block further input iff:
177 	 * Current input > threshold AND input is available to user program
178 	 */
179 	if (x >= TTYHOG/2 && (tp->t_state & TS_TBLOCK) == 0 &&
180 	    ((tp->t_lflag&ICANON) == 0) || (tp->t_canq.c_cc > 0) &&
181 	    tp->t_cc[VSTOP] != _POSIX_VDISABLE) {
182 		if (putc(tp->t_cc[VSTOP], &tp->t_outq) == 0) {
183 			tp->t_state |= TS_TBLOCK;
184 			ttstart(tp);
185 		}
186 	}
187 }
188 
189 /*
190  * Restart typewriter output following a delay
191  * timeout.
192  * The name of the routine is passed to the timeout
193  * subroutine and it is called during a clock interrupt.
194  */
195 ttrstrt(tp)
196 	struct tty *tp;
197 {
198 
199 #ifdef DIAGNOSTIC
200 	if (tp == 0)
201 		panic("ttrstrt");
202 #endif
203 	tp->t_state &= ~TS_TIMEOUT;
204 	ttstart(tp);
205 }
206 
207 /*
208  * Start output on the typewriter. It is used from the top half
209  * after some characters have been put on the output queue,
210  * from the interrupt routine to transmit the next
211  * character, and after a timeout has finished.
212  */
213 ttstart(tp)
214 	struct tty *tp;
215 {
216 
217 	if (tp->t_oproc)		/* kludge for pty */
218 		(*tp->t_oproc)(tp);
219 }
220 
221 /*
222  * Common code for tty ioctls.
223  */
224 /*ARGSUSED*/
225 ttioctl(tp, com, data, flag)
226 	register struct tty *tp;
227 	caddr_t data;
228 {
229 	extern int nldisp;
230 	int s, error;
231 
232 	/*
233 	 * If the ioctl involves modification,
234 	 * hang if in the background.
235 	 */
236 	switch (com) {
237 
238 	case TIOCSETD:
239 	case TIOCFLUSH:
240 	/*case TIOCSPGRP:*/
241 	case TIOCSTI:
242 	case TIOCSWINSZ:
243 	case TIOCSETA:
244 	case TIOCSETAW:
245 	case TIOCSETAF:
246 /**** these get removed ****
247 	case TIOCSETAS:
248 	case TIOCSETAWS:
249 	case TIOCSETAFS:
250 /***************************/
251 #ifdef COMPAT_43
252 	case TIOCSETP:
253 	case TIOCSETN:
254 	case TIOCSETC:
255 	case TIOCSLTC:
256 	case TIOCLBIS:
257 	case TIOCLBIC:
258 	case TIOCLSET:
259 	case OTIOCSETD:
260 #endif
261 		while (isbackground(u.u_procp, tp) &&
262 		   u.u_procp->p_pgrp->pg_jobc &&
263 		   (u.u_procp->p_flag&SVFORK) == 0 &&
264 		   (u.u_procp->p_sigignore & sigmask(SIGTTOU)) == 0 &&
265 		   (u.u_procp->p_sigmask & sigmask(SIGTTOU)) == 0) {
266 			pgsignal(u.u_procp->p_pgrp, SIGTTOU, 1);
267 			if (error = ttysleep(tp, (caddr_t)&lbolt,
268 			    TTOPRI | PCATCH, ttybg, 0))
269 				return (error);
270 		}
271 		break;
272 	}
273 
274 	/*
275 	 * Process the ioctl.
276 	 */
277 	switch (com) {
278 
279 	/* get discipline number */
280 	case TIOCGETD:
281 		*(int *)data = tp->t_line;
282 		break;
283 
284 	/* set line discipline */
285 	case TIOCSETD: {
286 		register int t = *(int *)data;
287 		dev_t dev = tp->t_dev;
288 
289 		if ((unsigned)t >= nldisp)
290 			return (ENXIO);
291 		if (t != tp->t_line) {
292 			s = spltty();
293 			(*linesw[tp->t_line].l_close)(tp);
294 			error = (*linesw[t].l_open)(dev, tp);
295 			if (error) {
296 				(void)(*linesw[tp->t_line].l_open)(dev, tp);
297 				splx(s);
298 				return (error);
299 			}
300 			tp->t_line = t;
301 			splx(s);
302 		}
303 		break;
304 	}
305 
306 	/* prevent more opens on channel */
307 	case TIOCEXCL:
308 		tp->t_state |= TS_XCLUDE;
309 		break;
310 
311 	case TIOCNXCL:
312 		tp->t_state &= ~TS_XCLUDE;
313 		break;
314 
315 	case TIOCHPCL:
316 		tp->t_cflag |= HUPCL;
317 		break;
318 
319 	case TIOCFLUSH: {
320 		register int flags = *(int *)data;
321 
322 		if (flags == 0)
323 			flags = FREAD|FWRITE;
324 		else
325 			flags &= FREAD|FWRITE;
326 		ttyflush(tp, flags);
327 		break;
328 	}
329 
330 	case FIOASYNC:
331 		if (*(int *)data)
332 			tp->t_state |= TS_ASYNC;
333 		else
334 			tp->t_state &= ~TS_ASYNC;
335 		break;
336 
337 	case FIONBIO:
338 		break;	/* XXX remove */
339 
340 	/* return number of characters immediately available */
341 	case FIONREAD:
342 		*(off_t *)data = ttnread(tp);
343 		break;
344 
345 	case TIOCOUTQ:
346 		*(int *)data = tp->t_outq.c_cc;
347 		break;
348 
349 	case TIOCSTOP:
350 		s = spltty();
351 		if ((tp->t_state&TS_TTSTOP) == 0) {
352 			tp->t_state |= TS_TTSTOP;
353 			(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
354 		}
355 		splx(s);
356 		break;
357 
358 	case TIOCSTART:
359 		s = spltty();
360 		if ((tp->t_state&TS_TTSTOP) || (tp->t_lflag&FLUSHO)) {
361 			tp->t_state &= ~TS_TTSTOP;
362 			tp->t_lflag &= ~FLUSHO;
363 			ttstart(tp);
364 		}
365 		splx(s);
366 		break;
367 
368 	/*
369 	 * Simulate typing of a character at the terminal.
370 	 */
371 	case TIOCSTI:
372 		if (u.u_uid && (flag & FREAD) == 0)
373 			return (EPERM);
374 		if (u.u_uid && !isctty(u.u_procp, tp))
375 			return (EACCES);
376 		(*linesw[tp->t_line].l_rint)(*(char *)data, tp);
377 		break;
378 
379 	case TIOCGETA: {
380 		struct termios *t = (struct termios *)data;
381 
382 		bcopy(&tp->t_termios, t, sizeof(struct termios));
383 		break;
384 	}
385 
386 	/*** THIS ALL GETS REMOVED ***/
387 	case JUNK_TIOCSETAS:
388 	case JUNK_TIOCSETAWS:
389 	case JUNK_TIOCSETAFS:
390 		((struct termios *)data)->c_cflag |= CIGNORE;
391 		switch(com) {
392 		case JUNK_TIOCSETAS:
393 			com = TIOCSETA;
394 			break;
395 		case JUNK_TIOCSETAWS:
396 			com = TIOCSETAW;
397 			break;
398 		case JUNK_TIOCSETAFS:
399 			com = TIOCSETAF;
400 			break;
401 		}
402 	/*******************************/
403 		/*FALLTHROGH*/
404 	case TIOCSETA:
405 	case TIOCSETAW:
406 	case TIOCSETAF: {
407 		register struct termios *t = (struct termios *)data;
408 
409 		s = spltty();
410 		if (com == TIOCSETAW || com == TIOCSETAF) {
411 			if (error = ttywait(tp)) {
412 				splx(s);
413 				return (error);
414 			}
415 			if (com == TIOCSETAF);
416 				ttyflush(tp, FREAD);
417 		}
418 		if ((t->c_cflag&CIGNORE) == 0) {
419 			/*
420 			 * set device hardware
421 			 */
422 			if (tp->t_param && (error = (*tp->t_param)(tp, t))) {
423 				splx(s);
424 				return (error);
425 			} else {
426 				if ((tp->t_state&TS_CARR_ON) == 0 &&
427 				    (tp->t_cflag&CLOCAL) &&
428 				    (t->c_cflag&CLOCAL) == 0) {
429 					tp->t_state &= ~TS_ISOPEN;
430 					tp->t_state |= TS_WOPEN;
431 					ttwakeup(tp);
432 				}
433 				tp->t_cflag = t->c_cflag;
434 				tp->t_ispeed = t->c_ispeed;
435 				tp->t_ospeed = t->c_ospeed;
436 			}
437 			ttsetwater(tp);
438 		}
439 		if (com != TIOCSETAF) {
440 			if ((t->c_lflag&ICANON) != (tp->t_lflag&ICANON))
441 				if (t->c_lflag&ICANON) {
442 					tp->t_lflag |= PENDIN;
443 					ttwakeup(tp);
444 				}
445 				else {
446 					struct clist tq;
447 
448 					catq(&tp->t_rawq, &tp->t_canq);
449 					tq = tp->t_rawq;
450 					tp->t_rawq = tp->t_canq;
451 					tp->t_canq = tq;
452 				}
453 		}
454 		tp->t_iflag = t->c_iflag;
455 		tp->t_oflag = t->c_oflag;
456 		/*
457 		 * Make the EXTPROC bit read only.
458 		 */
459 		if (tp->t_lflag&EXTPROC)
460 			t->c_lflag |= EXTPROC;
461 		else
462 			t->c_lflag &= ~EXTPROC;
463 		tp->t_lflag = t->c_lflag;
464 		bcopy(t->c_cc, tp->t_cc, sizeof(t->c_cc));
465 		splx(s);
466 		break;
467 	}
468 
469 	/*
470 	 * Set controlling terminal.
471 	 * Session ctty vnode pointer set in vnode layer.
472 	 */
473 	case TIOCSCTTY: {
474 		register struct proc *p = u.u_procp;
475 
476 		if (!SESS_LEADER(p) ||
477 		   (p->p_session->s_ttyvp || tp->t_session) &&
478 		   (tp->t_session != p->p_session))
479 			return (EPERM);
480 		tp->t_session = p->p_session;
481 		tp->t_pgrp = p->p_pgrp;
482 		p->p_session->s_ttyp = tp;
483 		p->p_flag |= SCTTY;
484 		break;
485 	}
486 
487 	/*
488 	 * Set terminal process group.
489 	 */
490 	case TIOCSPGRP: {
491 		register struct proc *p = u.u_procp;
492 		register struct pgrp *pgrp = pgfind(*(int *)data);
493 
494 		if (!isctty(p, tp))
495 			return (ENOTTY);
496 		else if (pgrp == NULL || pgrp->pg_session != p->p_session)
497 			return (EPERM);
498 		tp->t_pgrp = pgrp;
499 		break;
500 	}
501 
502 	case TIOCGPGRP:
503 		if (!isctty(u.u_procp, tp))
504 			return (ENOTTY);
505 		*(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
506 		break;
507 
508 	case TIOCSWINSZ:
509 		if (bcmp((caddr_t)&tp->t_winsize, data,
510 		    sizeof (struct winsize))) {
511 			tp->t_winsize = *(struct winsize *)data;
512 			pgsignal(tp->t_pgrp, SIGWINCH, 1);
513 		}
514 		break;
515 
516 	case TIOCGWINSZ:
517 		*(struct winsize *)data = tp->t_winsize;
518 		break;
519 
520 	case TIOCCONS:
521 		if (*(int *)data) {
522 			if (constty && constty != tp &&
523 			    (constty->t_state & (TS_CARR_ON|TS_ISOPEN)) ==
524 			    (TS_CARR_ON|TS_ISOPEN))
525 				return (EBUSY);
526 #ifndef	UCONSOLE
527 			if (error = suser(u.u_cred, &u.u_acflag))
528 				return (error);
529 #endif
530 			constty = tp;
531 		} else if (tp == constty)
532 			constty = NULL;
533 		break;
534 
535 #ifdef COMPAT_43
536 	case TIOCGETP:
537 	case TIOCSETP:
538 	case TIOCSETN:
539 	case TIOCGETC:
540 	case TIOCSETC:
541 	case TIOCSLTC:
542 	case TIOCGLTC:
543 	case TIOCLBIS:
544 	case TIOCLBIC:
545 	case TIOCLSET:
546 	case TIOCLGET:
547 	case OTIOCGETD:
548 	case OTIOCSETD:
549 	case OTIOCCONS:
550 		return(ttcompat(tp, com, data, flag));
551 #endif
552 
553 	default:
554 		return (-1);
555 	}
556 	return (0);
557 }
558 
559 ttnread(tp)
560 	struct tty *tp;
561 {
562 	int nread = 0;
563 
564 	if (tp->t_lflag & PENDIN)
565 		ttypend(tp);
566 	nread = tp->t_canq.c_cc;
567 	if ((tp->t_lflag & ICANON) == 0)
568 		nread += tp->t_rawq.c_cc;
569 	return (nread);
570 }
571 
572 ttselect(dev, rw)
573 	dev_t dev;
574 	int rw;
575 {
576 	register struct tty *tp = &cdevsw[major(dev)].d_ttys[minor(dev)];
577 	int nread;
578 	int s = spltty();
579 
580 	switch (rw) {
581 
582 	case FREAD:
583 		nread = ttnread(tp);
584 		if (nread > 0 ||
585 		   ((tp->t_cflag&CLOCAL) == 0 && (tp->t_state&TS_CARR_ON) == 0))
586 			goto win;
587 		if (tp->t_rsel && tp->t_rsel->p_wchan == (caddr_t)&selwait)
588 			tp->t_state |= TS_RCOLL;
589 		else
590 			tp->t_rsel = u.u_procp;
591 		break;
592 
593 	case FWRITE:
594 		if (tp->t_outq.c_cc <= tp->t_lowat)
595 			goto win;
596 		if (tp->t_wsel && tp->t_wsel->p_wchan == (caddr_t)&selwait)
597 			tp->t_state |= TS_WCOLL;
598 		else
599 			tp->t_wsel = u.u_procp;
600 		break;
601 	}
602 	splx(s);
603 	return (0);
604 win:
605 	splx(s);
606 	return (1);
607 }
608 
609 /*
610  * Initial open of tty, or (re)entry to line discipline.
611  */
612 ttyopen(dev, tp)
613 	dev_t dev;
614 	register struct tty *tp;
615 {
616 
617 	tp->t_dev = dev;
618 
619 	tp->t_state &= ~TS_WOPEN;
620 	if ((tp->t_state & TS_ISOPEN) == 0) {
621 		tp->t_state |= TS_ISOPEN;
622 		bzero((caddr_t)&tp->t_winsize, sizeof(tp->t_winsize));
623 	}
624 	return (0);
625 }
626 
627 /*
628  * "close" a line discipline
629  */
630 ttylclose(tp)
631 	register struct tty *tp;
632 {
633 
634 	ttywflush(tp);
635 }
636 
637 /*
638  * clean tp on last close
639  */
640 ttyclose(tp)
641 	register struct tty *tp;
642 {
643 	if (constty == tp)
644 		constty = NULL;
645 	ttyflush(tp, FREAD|FWRITE);
646 	tp->t_session = NULL;
647 	tp->t_pgrp = NULL;
648 	tp->t_state = 0;
649 	tp->t_gen++;
650 	return (0);
651 }
652 
653 /*
654  * Handle modem control transition on a tty.
655  * Flag indicates new state of carrier.
656  * Returns 0 if the line should be turned off, otherwise 1.
657  */
658 ttymodem(tp, flag)
659 	register struct tty *tp;
660 {
661 
662 	if ((tp->t_state&TS_WOPEN) == 0 && (tp->t_lflag&MDMBUF)) {
663 		/*
664 		 * MDMBUF: do flow control according to carrier flag
665 		 */
666 		if (flag) {
667 			tp->t_state &= ~TS_TTSTOP;
668 			ttstart(tp);
669 		} else if ((tp->t_state&TS_TTSTOP) == 0) {
670 			tp->t_state |= TS_TTSTOP;
671 			(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
672 		}
673 	} else if (flag == 0) {
674 		/*
675 		 * Lost carrier.
676 		 */
677 		tp->t_state &= ~TS_CARR_ON;
678 		if (tp->t_state&TS_ISOPEN && (tp->t_cflag&CLOCAL) == 0) {
679 			if (tp->t_session && tp->t_session->s_leader)
680 				psignal(tp->t_session->s_leader, SIGHUP);
681 			ttyflush(tp, FREAD|FWRITE);
682 			return (0);
683 		}
684 	} else {
685 		/*
686 		 * Carrier now on.
687 		 */
688 		tp->t_state |= TS_CARR_ON;
689 		ttwakeup(tp);
690 	}
691 	return (1);
692 }
693 
694 /*
695  * Default modem control routine (for other line disciplines).
696  * Return argument flag, to turn off device on carrier drop.
697  */
698 nullmodem(tp, flag)
699 	register struct tty *tp;
700 	int flag;
701 {
702 
703 	if (flag)
704 		tp->t_state |= TS_CARR_ON;
705 	else {
706 		tp->t_state &= ~TS_CARR_ON;
707 		if ((tp->t_cflag&CLOCAL) == 0) {
708 			if (tp->t_session && tp->t_session->s_leader)
709 				psignal(tp->t_session->s_leader, SIGHUP);
710 			return (0);
711 		}
712 	}
713 	return (1);
714 }
715 
716 /*
717  * reinput pending characters after state switch
718  * call at spltty().
719  */
720 ttypend(tp)
721 	register struct tty *tp;
722 {
723 	struct clist tq;
724 	register c;
725 
726 	tp->t_lflag &= ~PENDIN;
727 	tp->t_state |= TS_TYPEN;
728 	tq = tp->t_rawq;
729 	tp->t_rawq.c_cc = 0;
730 	tp->t_rawq.c_cf = tp->t_rawq.c_cl = 0;
731 	while ((c = getc(&tq)) >= 0)
732 		ttyinput(c, tp);
733 	tp->t_state &= ~TS_TYPEN;
734 }
735 
736 /*
737  *
738  * Place a character on raw TTY input queue,
739  * putting in delimiters and waking up top
740  * half as needed.  Also echo if required.
741  * The arguments are the character and the
742  * appropriate tty structure.
743  */
744 ttyinput(c, tp)
745 	register c;
746 	register struct tty *tp;
747 {
748 	register int iflag = tp->t_iflag;
749 	register int lflag = tp->t_lflag;
750 	register u_char *cc = tp->t_cc;
751 	int i, err;
752 
753 	/*
754 	 * If input is pending take it first.
755 	 */
756 	if (lflag&PENDIN)
757 		ttypend(tp);
758 	/*
759 	 * Gather stats.
760 	 */
761 	tk_nin++;
762 	if (lflag&ICANON) {
763 		tk_cancc++;
764 		tp->t_cancc++;
765 	} else {
766 		tk_rawcc++;
767 		tp->t_rawcc++;
768 	}
769 	/*
770 	 * Handle exceptional conditions (break, parity, framing).
771 	 */
772 	if (err = (c&TTY_ERRORMASK)) {
773 		c &= ~TTY_ERRORMASK;
774 		if (err&TTY_FE && !c) {		/* break */
775 			if (iflag&IGNBRK)
776 				goto endcase;
777 			else if (iflag&BRKINT && lflag&ISIG &&
778 				(cc[VINTR] != _POSIX_VDISABLE))
779 				c = cc[VINTR];
780 			else {
781 				c = 0;
782 				if (iflag&PARMRK)
783 					goto parmrk;
784 			}
785 		} else if ((err&TTY_PE && iflag&INPCK) || err&TTY_FE) {
786 			if (iflag&IGNPAR)
787 				goto endcase;
788 			else if (iflag&PARMRK) {
789 parmrk:
790 				putc(0377|TTY_QUOTE, &tp->t_rawq);
791 				putc(0|TTY_QUOTE, &tp->t_rawq);
792 				putc(c|TTY_QUOTE, &tp->t_rawq);
793 				goto endcase;
794 			} else
795 				c = 0;
796 		}
797 	}
798 	/*
799 	 * In tandem mode, check high water mark.
800 	 */
801 	if (iflag&IXOFF)
802 		ttyblock(tp);
803 	if ((tp->t_state&TS_TYPEN) == 0 && (iflag&ISTRIP))
804 		c &= 0177;
805     if ((tp->t_lflag&EXTPROC) == 0) {
806 	/*
807 	 * Check for literal nexting very first
808 	 */
809 	if (tp->t_state&TS_LNCH) {
810 		c |= TTY_QUOTE;
811 		tp->t_state &= ~TS_LNCH;
812 	}
813 	/*
814 	 * Scan for special characters.  This code
815 	 * is really just a big case statement with
816 	 * non-constant cases.  The bottom of the
817 	 * case statement is labeled ``endcase'', so goto
818 	 * it after a case match, or similar.
819 	 */
820 	/*
821 	 * Control chars which aren't controlled
822 	 * by ICANON, ISIG, or IXON.
823 	 */
824 	if (lflag&IEXTEN) {
825 		if (CCEQ(cc[VLNEXT], c)) {
826 			if (lflag&ECHO) {
827 				if (lflag&ECHOE)
828 					ttyoutstr("^\b", tp);
829 				else
830 					ttyecho(c, tp);
831 			}
832 			tp->t_state |= TS_LNCH;
833 			goto endcase;
834 		}
835 		if (CCEQ(cc[VDISCARD], c)) {
836 			if (lflag&FLUSHO)
837 				tp->t_lflag &= ~FLUSHO;
838 			else {
839 				ttyflush(tp, FWRITE);
840 				ttyecho(c, tp);
841 				if (tp->t_rawq.c_cc + tp->t_canq.c_cc)
842 					ttyretype(tp);
843 				tp->t_lflag |= FLUSHO;
844 			}
845 			goto startoutput;
846 		}
847 	}
848 	/*
849 	 * Signals.
850 	 */
851 	if (lflag&ISIG) {
852 		if (CCEQ(cc[VINTR], c) || CCEQ(cc[VQUIT], c)) {
853 			if ((lflag&NOFLSH) == 0)
854 				ttyflush(tp, FREAD|FWRITE);
855 			ttyecho(c, tp);
856 			pgsignal(tp->t_pgrp,
857 			    CCEQ(cc[VINTR], c) ? SIGINT : SIGQUIT, 1);
858 			goto endcase;
859 		}
860 		if (CCEQ(cc[VSUSP], c)) {
861 			if ((lflag&NOFLSH) == 0)
862 				ttyflush(tp, FREAD);
863 			ttyecho(c, tp);
864 			pgsignal(tp->t_pgrp, SIGTSTP, 1);
865 			goto endcase;
866 		}
867 	}
868 	/*
869 	 * Handle start/stop characters.
870 	 */
871 	if (iflag&IXON) {
872 		if (CCEQ(cc[VSTOP], c)) {
873 			if ((tp->t_state&TS_TTSTOP) == 0) {
874 				tp->t_state |= TS_TTSTOP;
875 				(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
876 				return;
877 			}
878 			if (!CCEQ(cc[VSTART], c))
879 				return;
880 			/*
881 			 * if VSTART == VSTOP then toggle
882 			 */
883 			goto endcase;
884 		}
885 		if (CCEQ(cc[VSTART], c))
886 			goto restartoutput;
887 	}
888 	/*
889 	 * IGNCR, ICRNL, & INLCR
890 	 */
891 	if (c == '\r') {
892 		if (iflag&IGNCR)
893 			goto endcase;
894 		else if (iflag&ICRNL)
895 			c = '\n';
896 	}
897 	else if (c == '\n' && iflag&INLCR)
898 		c = '\r';
899     }
900 	/*
901 	 * Non canonical mode; don't process line editing
902 	 * characters; check high water mark for wakeup.
903 	 *
904 	 */
905 	if ((lflag&ICANON) == 0) {
906 		if (tp->t_rawq.c_cc > TTYHOG) {
907 			if (iflag&IMAXBEL) {
908 				if (tp->t_outq.c_cc < tp->t_hiwat)
909 					(void) ttyoutput(CTRL('g'), tp);
910 			} else
911 				ttyflush(tp, FREAD | FWRITE);
912 		} else {
913 			if (putc(c, &tp->t_rawq) >= 0) {
914 				ttwakeup(tp);
915 				ttyecho(c, tp);
916 			}
917 		}
918 		goto endcase;
919 	}
920     if ((tp->t_lflag&EXTPROC) == 0) {
921 	/*
922 	 * From here on down canonical mode character
923 	 * processing takes place.
924 	 */
925 	/*
926 	 * erase (^H / ^?)
927 	 */
928 	if ((c == cc[VERASE] || c == cc[VERASE2]) && c != _POSIX_VDISABLE &&
929 	     cc[VERASE] != _POSIX_VDISABLE) {
930 		if (tp->t_rawq.c_cc)
931 			ttyrub(unputc(&tp->t_rawq), tp);
932 		goto endcase;
933 	}
934 	/*
935 	 * kill (^U)
936 	 */
937 	if (CCEQ(cc[VKILL], c)) {
938 		if (lflag&ECHOKE && tp->t_rawq.c_cc == tp->t_rocount &&
939 		    (lflag&ECHOPRT) == 0) {
940 			while (tp->t_rawq.c_cc)
941 				ttyrub(unputc(&tp->t_rawq), tp);
942 		} else {
943 			ttyecho(c, tp);
944 			if (lflag&ECHOK || lflag&ECHOKE)
945 				ttyecho('\n', tp);
946 			while (getc(&tp->t_rawq) > 0)
947 				;
948 			tp->t_rocount = 0;
949 		}
950 		tp->t_state &= ~TS_LOCAL;
951 		goto endcase;
952 	}
953 	/*
954 	 * word erase (^W)
955 	 */
956 	if (CCEQ(cc[VWERASE], c)) {
957 		int ctype;
958 
959 #define CTYPE(c) ((lflag&ALTWERASE) ? (partab[(c)&TTY_CHARMASK]&0100) : 0)
960 		/*
961 		 * erase whitespace
962 		 */
963 		while ((c = unputc(&tp->t_rawq)) == ' ' || c == '\t')
964 			ttyrub(c, tp);
965 		if (c == -1)
966 			goto endcase;
967 		/*
968 		 * special case last char of token
969 		 */
970 		ttyrub(c, tp);
971 		c = unputc(&tp->t_rawq);
972 		if (c == -1 || c == ' ' || c == '\t') {
973 			if (c != -1)
974 				(void) putc(c, &tp->t_rawq);
975 			goto endcase;
976 		}
977 		/*
978 		 * erase rest of token
979 		 */
980 		ctype = CTYPE(c);
981 		do {
982 			ttyrub(c, tp);
983 			c = unputc(&tp->t_rawq);
984 			if (c == -1)
985 				goto endcase;
986 		} while (c != ' ' && c != '\t' && CTYPE(c) == ctype);
987 		(void) putc(c, &tp->t_rawq);
988 		goto endcase;
989 #undef CTYPE
990 	}
991 	/*
992 	 * reprint line (^R)
993 	 */
994 	if (CCEQ(cc[VREPRINT], c)) {
995 		ttyretype(tp);
996 		goto endcase;
997 	}
998 	/*
999 	 * ^T - kernel info and generate SIGINFO
1000 	 */
1001 	if (CCEQ(cc[VSTATUS], c)) {
1002 		pgsignal(tp->t_pgrp, SIGINFO, 1);
1003 		if ((lflag&NOKERNINFO) == 0)
1004 			ttyinfo(tp);
1005 		goto endcase;
1006 	}
1007     }
1008 	/*
1009 	 * Check for input buffer overflow
1010 	 */
1011 	if (tp->t_rawq.c_cc+tp->t_canq.c_cc >= TTYHOG) {
1012 		if (iflag&IMAXBEL) {
1013 			if (tp->t_outq.c_cc < tp->t_hiwat)
1014 				(void) ttyoutput(CTRL('g'), tp);
1015 		} else
1016 			ttyflush(tp, FREAD | FWRITE);
1017 		goto endcase;
1018 	}
1019 	/*
1020 	 * Put data char in q for user and
1021 	 * wakeup on seeing a line delimiter.
1022 	 */
1023 	if (putc(c, &tp->t_rawq) >= 0) {
1024 		if (ttbreakc(c)) {
1025 			tp->t_rocount = 0;
1026 			catq(&tp->t_rawq, &tp->t_canq);
1027 			ttwakeup(tp);
1028 		} else if (tp->t_rocount++ == 0)
1029 			tp->t_rocol = tp->t_col;
1030 		if (tp->t_state&TS_ERASE) {
1031 			/*
1032 			 * end of prterase \.../
1033 			 */
1034 			tp->t_state &= ~TS_ERASE;
1035 			(void) ttyoutput('/', tp);
1036 		}
1037 		i = tp->t_col;
1038 		ttyecho(c, tp);
1039 		if (CCEQ(cc[VEOF], c) && lflag&ECHO) {
1040 			/*
1041 			 * Place the cursor over the '^' of the ^D.
1042 			 */
1043 			i = MIN(2, tp->t_col - i);
1044 			while (i > 0) {
1045 				(void) ttyoutput('\b', tp);
1046 				i--;
1047 			}
1048 		}
1049 	}
1050 endcase:
1051 	/*
1052 	 * IXANY means allow any character to restart output.
1053 	 */
1054 	if ((tp->t_state&TS_TTSTOP) && (iflag&IXANY) == 0 &&
1055 	    cc[VSTART] != cc[VSTOP])
1056 		return;
1057 restartoutput:
1058 	tp->t_state &= ~TS_TTSTOP;
1059 	tp->t_lflag &= ~FLUSHO;
1060 startoutput:
1061 	ttstart(tp);
1062 }
1063 
1064 /*
1065  * Put character on TTY output queue, adding delays,
1066  * expanding tabs, and handling the CR/NL bit.
1067  * This is called both from the top half for output,
1068  * and from interrupt level for echoing.
1069  * The arguments are the character and the tty structure.
1070  * Returns < 0 if putc succeeds, otherwise returns char to resend
1071  * Must be recursive.
1072  */
1073 ttyoutput(c, tp)
1074 	register c;
1075 	register struct tty *tp;
1076 {
1077 	register char *colp;
1078 	register ctype;
1079 	register long oflag = tp->t_oflag;
1080 
1081 	if ((oflag&OPOST) == 0) {
1082 		if (tp->t_lflag&FLUSHO)
1083 			return (-1);
1084 		if (putc(c, &tp->t_outq))
1085 			return (c);
1086 		tk_nout++;
1087 		tp->t_outcc++;
1088 		return (-1);
1089 	}
1090 	c &= TTY_CHARMASK;
1091 	/*
1092 	 * Turn tabs to spaces as required
1093 	 *
1094 	 * Special case if we have external processing, we don't
1095 	 * do the tab expansion because we'll probably get it
1096 	 * wrong.  If tab expansion needs to be done, let it
1097 	 * happen externally.
1098 	 */
1099 	if ((tp->t_lflag&EXTPROC) == 0 &&
1100 	    c == '\t' && oflag&OXTABS ) {
1101 		register int s;
1102 
1103 		c = 8 - (tp->t_col&7);
1104 		if ((tp->t_lflag&FLUSHO) == 0) {
1105 			s = spltty();		/* don't interrupt tabs */
1106 			c -= b_to_q("        ", c, &tp->t_outq);
1107 			tk_nout += c;
1108 			tp->t_outcc += c;
1109 			splx(s);
1110 		}
1111 		tp->t_col += c;
1112 		return (c ? -1 : '\t');
1113 	}
1114 	if (c == CEOT && oflag&ONOEOT)
1115 		return(-1);
1116 	tk_nout++;
1117 	tp->t_outcc++;
1118 	/*
1119 	 * turn <nl> to <cr><lf> if desired.
1120 	 */
1121 	if (c == '\n' && (tp->t_oflag&ONLCR) && ttyoutput('\r', tp) >= 0)
1122 		return (c);
1123 	if ((tp->t_lflag&FLUSHO) == 0 && putc(c, &tp->t_outq))
1124 		return (c);
1125 	/*
1126 	 * Calculate delays.
1127 	 * The numbers here represent clock ticks
1128 	 * and are not necessarily optimal for all terminals.
1129 	 *
1130 	 * SHOULD JUST ALLOW USER TO SPECIFY DELAYS
1131 	 *
1132 	 * (actually, should THROW AWAY terminals which need delays)
1133 	 */
1134 	colp = &tp->t_col;
1135 	ctype = partab[c];
1136 	c = 0;
1137 	switch (ctype&077) {
1138 
1139 	case ORDINARY:
1140 		(*colp)++;
1141 
1142 	case CONTROL:
1143 		break;
1144 
1145 	case BACKSPACE:
1146 		if (*colp)
1147 			(*colp)--;
1148 		break;
1149 
1150 	/*
1151 	 * This macro is close enough to the correct thing;
1152 	 * it should be replaced by real user settable delays
1153 	 * in any event...
1154 	 */
1155 #define	mstohz(ms)	(((ms) * hz) >> 10)
1156 	case NEWLINE:
1157 		ctype = (tp->t_flags >> 8) & 03;
1158 		if (ctype == 1) { /* tty 37 */
1159 			if (*colp > 0) {
1160 				c = (((unsigned)*colp) >> 4) + 3;
1161 				if ((unsigned)c > 6)
1162 					c = 6;
1163 			}
1164 		} else if (ctype == 2) /* vt05 */
1165 			c = mstohz(100);
1166 		*colp = 0;
1167 		break;
1168 
1169 	case TAB:
1170 		ctype = (tp->t_flags >> 10) & 03;
1171 		if (ctype == 1) { /* tty 37 */
1172 			c = 1 - (*colp | ~07);
1173 			if (c < 5)
1174 				c = 0;
1175 		}
1176 		*colp |= 07;
1177 		(*colp)++;
1178 		break;
1179 
1180 	case VTAB:
1181 		if (tp->t_flags&VTDELAY) /* tty 37 */
1182 			c = 0177;
1183 		break;
1184 
1185 	case RETURN:
1186 		ctype = (tp->t_flags >> 12) & 03;
1187 		if (ctype == 1) /* tn 300 */
1188 			c = mstohz(83);
1189 		else if (ctype == 2) /* ti 700 */
1190 			c = mstohz(166);
1191 		else if (ctype == 3) { /* concept 100 */
1192 			int i;
1193 
1194 			if ((i = *colp) >= 0)
1195 				for (; i < 9; i++)
1196 					(void) putc(0177, &tp->t_outq);
1197 		}
1198 		*colp = 0;
1199 	}
1200 	if (c && (tp->t_lflag&FLUSHO) == 0)
1201 		(void) putc(c|TTY_QUOTE, &tp->t_outq);
1202 	return (-1);
1203 }
1204 #undef mstohz
1205 
1206 /*
1207  * Called from device's read routine after it has
1208  * calculated the tty-structure given as argument.
1209  */
1210 ttread(tp, uio, flag)
1211 	register struct tty *tp;
1212 	struct uio *uio;
1213 {
1214 	register struct clist *qp;
1215 	register int c;
1216 	register long lflag;
1217 	register u_char *cc = tp->t_cc;
1218 	int s, first, error = 0;
1219 
1220 loop:
1221 	lflag = tp->t_lflag;
1222 	s = spltty();
1223 	/*
1224 	 * take pending input first
1225 	 */
1226 	if (lflag&PENDIN)
1227 		ttypend(tp);
1228 	splx(s);
1229 
1230 	/*
1231 	 * Hang process if it's in the background.
1232 	 */
1233 	if (isbackground(u.u_procp, tp)) {
1234 		if ((u.u_procp->p_sigignore & sigmask(SIGTTIN)) ||
1235 		   (u.u_procp->p_sigmask & sigmask(SIGTTIN)) ||
1236 		    u.u_procp->p_flag&SVFORK || u.u_procp->p_pgrp->pg_jobc == 0)
1237 			return (EIO);
1238 		pgsignal(u.u_procp->p_pgrp, SIGTTIN, 1);
1239 		if (error = ttysleep(tp, (caddr_t)&lbolt, TTIPRI | PCATCH,
1240 		    ttybg, 0))
1241 			return (error);
1242 		goto loop;
1243 	}
1244 
1245 	/*
1246 	 * If canonical, use the canonical queue,
1247 	 * else use the raw queue.
1248 	 *
1249 	 * XXX - should get rid of canonical queue.
1250 	 * (actually, should get rid of clists...)
1251 	 */
1252 	qp = lflag&ICANON ? &tp->t_canq : &tp->t_rawq;
1253 
1254 	/*
1255 	 * If there is no input, sleep on rawq
1256 	 * awaiting hardware receipt and notification.
1257 	 * If we have data, we don't need to check for carrier.
1258 	 */
1259 	s = spltty();
1260 	if (qp->c_cc <= 0) {
1261 		int carrier;
1262 
1263 		carrier = (tp->t_state&TS_CARR_ON) || (tp->t_cflag&CLOCAL);
1264 		if (!carrier && tp->t_state&TS_ISOPEN) {
1265 			splx(s);
1266 			return (0);	/* EOF */
1267 		}
1268 		if (flag & IO_NDELAY) {
1269 			splx(s);
1270 			return (EWOULDBLOCK);
1271 		}
1272 		error = ttysleep(tp, (caddr_t)&tp->t_rawq, TTIPRI | PCATCH,
1273 		    carrier ? ttyin : ttopen, 0);
1274 		splx(s);
1275 		if (error)
1276 			return (error);
1277 		goto loop;
1278 	}
1279 	splx(s);
1280 
1281 	/*
1282 	 * Input present, check for input mapping and processing.
1283 	 */
1284 	first = 1;
1285 	while ((c = getc(qp)) >= 0) {
1286 		/*
1287 		 * delayed suspend (^Y)
1288 		 */
1289 		if (CCEQ(cc[VDSUSP], c) && lflag&ISIG) {
1290 			pgsignal(tp->t_pgrp, SIGTSTP, 1);
1291 			if (first) {
1292 				if (error = ttysleep(tp, (caddr_t)&lbolt,
1293 				    TTIPRI | PCATCH, ttybg, 0))
1294 					break;
1295 				goto loop;
1296 			}
1297 			break;
1298 		}
1299 		/*
1300 		 * Interpret EOF only in canonical mode.
1301 		 */
1302 		if (CCEQ(cc[VEOF], c) && lflag&ICANON)
1303 			break;
1304 		/*
1305 		 * Give user character.
1306 		 */
1307  		error = ureadc(c, uio);
1308 		if (error)
1309 			break;
1310  		if (uio->uio_resid == 0)
1311 			break;
1312 		/*
1313 		 * In canonical mode check for a "break character"
1314 		 * marking the end of a "line of input".
1315 		 */
1316 		if (lflag&ICANON && ttbreakc(c))
1317 			break;
1318 		first = 0;
1319 	}
1320 	/*
1321 	 * Look to unblock output now that (presumably)
1322 	 * the input queue has gone down.
1323 	 */
1324 	if (tp->t_state&TS_TBLOCK && tp->t_rawq.c_cc < TTYHOG/5) {
1325 		if (cc[VSTART] != _POSIX_VDISABLE
1326 		   && putc(cc[VSTART], &tp->t_outq) == 0) {
1327 			tp->t_state &= ~TS_TBLOCK;
1328 			ttstart(tp);
1329 		}
1330 	}
1331 	return (error);
1332 }
1333 
1334 /*
1335  * Check the output queue on tp for space for a kernel message
1336  * (from uprintf/tprintf).  Allow some space over the normal
1337  * hiwater mark so we don't lose messages due to normal flow
1338  * control, but don't let the tty run amok.
1339  * Sleeps here are not interruptible, but we return prematurely
1340  * if new signals come in.
1341  */
1342 ttycheckoutq(tp, wait)
1343 	register struct tty *tp;
1344 	int wait;
1345 {
1346 	int hiwat, s, oldsig;
1347 
1348 	hiwat = tp->t_hiwat;
1349 	s = spltty();
1350 	oldsig = u.u_procp->p_sig;
1351 	if (tp->t_outq.c_cc > hiwat + 200)
1352 		while (tp->t_outq.c_cc > hiwat) {
1353 			ttstart(tp);
1354 			if (wait == 0 || u.u_procp->p_sig != oldsig) {
1355 				splx(s);
1356 				return (0);
1357 			}
1358 			timeout(wakeup, (caddr_t)&tp->t_outq, hz);
1359 			tp->t_state |= TS_ASLEEP;
1360 			sleep((caddr_t)&tp->t_outq, PZERO - 1);
1361 		}
1362 	splx(s);
1363 	return (1);
1364 }
1365 
1366 /*
1367  * Called from the device's write routine after it has
1368  * calculated the tty-structure given as argument.
1369  */
1370 ttwrite(tp, uio, flag)
1371 	register struct tty *tp;
1372 	register struct uio *uio;
1373 {
1374 	register char *cp;
1375 	register int cc = 0, ce;
1376 	int i, hiwat, cnt, error, s;
1377 	char obuf[OBUFSIZ];
1378 
1379 	hiwat = tp->t_hiwat;
1380 	cnt = uio->uio_resid;
1381 	error = 0;
1382 loop:
1383 	s = spltty();
1384 	if ((tp->t_state&TS_CARR_ON) == 0 && (tp->t_cflag&CLOCAL) == 0) {
1385 		if (tp->t_state&TS_ISOPEN) {
1386 			splx(s);
1387 			return (EIO);
1388 		} else if (flag & IO_NDELAY) {
1389 			splx(s);
1390 			error = EWOULDBLOCK;
1391 			goto out;
1392 		} else {
1393 			/*
1394 			 * sleep awaiting carrier
1395 			 */
1396 			error = ttysleep(tp, (caddr_t)&tp->t_rawq,
1397 					TTIPRI | PCATCH,ttopen, 0);
1398 			splx(s);
1399 			if (error)
1400 				goto out;
1401 			goto loop;
1402 		}
1403 	}
1404 	splx(s);
1405 	/*
1406 	 * Hang the process if it's in the background.
1407 	 */
1408 	if (isbackground(u.u_procp, tp) &&
1409 	    (tp->t_lflag&TOSTOP) && (u.u_procp->p_flag&SVFORK)==0 &&
1410 	    (u.u_procp->p_sigignore & sigmask(SIGTTOU)) == 0 &&
1411 	    (u.u_procp->p_sigmask & sigmask(SIGTTOU)) == 0 &&
1412 	     u.u_procp->p_pgrp->pg_jobc) {
1413 		pgsignal(u.u_procp->p_pgrp, SIGTTOU, 1);
1414 		if (error = ttysleep(tp, (caddr_t)&lbolt, TTIPRI | PCATCH,
1415 		    ttybg, 0))
1416 			goto out;
1417 		goto loop;
1418 	}
1419 	/*
1420 	 * Process the user's data in at most OBUFSIZ
1421 	 * chunks.  Perform any output translation.
1422 	 * Keep track of high water mark, sleep on overflow
1423 	 * awaiting device aid in acquiring new space.
1424 	 */
1425 	while (uio->uio_resid > 0 || cc > 0) {
1426 		if (tp->t_lflag&FLUSHO) {
1427 			uio->uio_resid = 0;
1428 			return (0);
1429 		}
1430 		if (tp->t_outq.c_cc > hiwat)
1431 			goto ovhiwat;
1432 		/*
1433 		 * Grab a hunk of data from the user,
1434 		 * unless we have some leftover from last time.
1435 		 */
1436 		if (cc == 0) {
1437 			cc = min(uio->uio_resid, OBUFSIZ);
1438 			cp = obuf;
1439 			error = uiomove(cp, cc, uio);
1440 			if (error) {
1441 				cc = 0;
1442 				break;
1443 			}
1444 		}
1445 		/*
1446 		 * If nothing fancy need be done, grab those characters we
1447 		 * can handle without any of ttyoutput's processing and
1448 		 * just transfer them to the output q.  For those chars
1449 		 * which require special processing (as indicated by the
1450 		 * bits in partab), call ttyoutput.  After processing
1451 		 * a hunk of data, look for FLUSHO so ^O's will take effect
1452 		 * immediately.
1453 		 */
1454 		while (cc > 0) {
1455 			if ((tp->t_oflag&OPOST) == 0)
1456 				ce = cc;
1457 			else {
1458 				ce = cc - scanc((unsigned)cc, (u_char *)cp,
1459 				   (u_char *)partab, 077);
1460 				/*
1461 				 * If ce is zero, then we're processing
1462 				 * a special character through ttyoutput.
1463 				 */
1464 				if (ce == 0) {
1465 					tp->t_rocount = 0;
1466 					if (ttyoutput(*cp, tp) >= 0) {
1467 					    /* no c-lists, wait a bit */
1468 					    ttstart(tp);
1469 					    if (error = ttysleep(tp,
1470 						(caddr_t)&lbolt,
1471 						 TTOPRI | PCATCH, ttybuf, 0))
1472 						    break;
1473 					    goto loop;
1474 					}
1475 					cp++, cc--;
1476 					if ((tp->t_lflag&FLUSHO) ||
1477 					    tp->t_outq.c_cc > hiwat)
1478 						goto ovhiwat;
1479 					continue;
1480 				}
1481 			}
1482 			/*
1483 			 * A bunch of normal characters have been found,
1484 			 * transfer them en masse to the output queue and
1485 			 * continue processing at the top of the loop.
1486 			 * If there are any further characters in this
1487 			 * <= OBUFSIZ chunk, the first should be a character
1488 			 * requiring special handling by ttyoutput.
1489 			 */
1490 			tp->t_rocount = 0;
1491 			i = b_to_q(cp, ce, &tp->t_outq);
1492 			ce -= i;
1493 			tp->t_col += ce;
1494 			cp += ce, cc -= ce, tk_nout += ce;
1495 			tp->t_outcc += ce;
1496 			if (i > 0) {
1497 				/* out of c-lists, wait a bit */
1498 				ttstart(tp);
1499 				if (error = ttysleep(tp, (caddr_t)&lbolt,
1500 					    TTOPRI | PCATCH, ttybuf, 0))
1501 					break;
1502 				goto loop;
1503 			}
1504 			if (tp->t_lflag&FLUSHO || tp->t_outq.c_cc > hiwat)
1505 				break;
1506 		}
1507 		ttstart(tp);
1508 	}
1509 out:
1510 	/*
1511 	 * If cc is nonzero, we leave the uio structure inconsistent,
1512 	 * as the offset and iov pointers have moved forward,
1513 	 * but it doesn't matter (the call will either return short
1514 	 * or restart with a new uio).
1515 	 */
1516 	uio->uio_resid += cc;
1517 	return (error);
1518 
1519 ovhiwat:
1520 	ttstart(tp);
1521 	s = spltty();
1522 	/*
1523 	 * This can only occur if FLUSHO is set in t_lflag,
1524 	 * or if ttstart/oproc is synchronous (or very fast).
1525 	 */
1526 	if (tp->t_outq.c_cc <= hiwat) {
1527 		splx(s);
1528 		goto loop;
1529 	}
1530 	if (flag & IO_NDELAY) {
1531 		splx(s);
1532 		uio->uio_resid += cc;
1533 		if (uio->uio_resid == cnt)
1534 			return (EWOULDBLOCK);
1535 		return (0);
1536 	}
1537 	tp->t_state |= TS_ASLEEP;
1538 	error = ttysleep(tp, (caddr_t)&tp->t_outq, TTOPRI | PCATCH, ttyout, 0);
1539 	splx(s);
1540 	if (error)
1541 		goto out;
1542 	goto loop;
1543 }
1544 
1545 /*
1546  * Rubout one character from the rawq of tp
1547  * as cleanly as possible.
1548  */
1549 ttyrub(c, tp)
1550 	register c;
1551 	register struct tty *tp;
1552 {
1553 	register char *cp;
1554 	register int savecol;
1555 	int s;
1556 	char *nextc();
1557 
1558 	if ((tp->t_lflag&ECHO) == 0 || (tp->t_lflag&EXTPROC))
1559 		return;
1560 	tp->t_lflag &= ~FLUSHO;
1561 	if (tp->t_lflag&ECHOE) {
1562 		if (tp->t_rocount == 0) {
1563 			/*
1564 			 * Screwed by ttwrite; retype
1565 			 */
1566 			ttyretype(tp);
1567 			return;
1568 		}
1569 		if (c == ('\t'|TTY_QUOTE) || c == ('\n'|TTY_QUOTE))
1570 			ttyrubo(tp, 2);
1571 		else switch (partab[c&=0377]&077) {
1572 
1573 		case ORDINARY:
1574 			ttyrubo(tp, 1);
1575 			break;
1576 
1577 		case VTAB:
1578 		case BACKSPACE:
1579 		case CONTROL:
1580 		case RETURN:
1581 			if (tp->t_lflag&ECHOCTL)
1582 				ttyrubo(tp, 2);
1583 			break;
1584 
1585 		case TAB: {
1586 			int c;
1587 
1588 			if (tp->t_rocount < tp->t_rawq.c_cc) {
1589 				ttyretype(tp);
1590 				return;
1591 			}
1592 			s = spltty();
1593 			savecol = tp->t_col;
1594 			tp->t_state |= TS_CNTTB;
1595 			tp->t_lflag |= FLUSHO;
1596 			tp->t_col = tp->t_rocol;
1597 			cp = tp->t_rawq.c_cf;
1598 			if (cp)
1599 				c = *cp;	/* XXX FIX NEXTC */
1600 			for (; cp; cp = nextc(&tp->t_rawq, cp, &c))
1601 				ttyecho(c, tp);
1602 			tp->t_lflag &= ~FLUSHO;
1603 			tp->t_state &= ~TS_CNTTB;
1604 			splx(s);
1605 			/*
1606 			 * savecol will now be length of the tab
1607 			 */
1608 			savecol -= tp->t_col;
1609 			tp->t_col += savecol;
1610 			if (savecol > 8)
1611 				savecol = 8;		/* overflow screw */
1612 			while (--savecol >= 0)
1613 				(void) ttyoutput('\b', tp);
1614 			break;
1615 		}
1616 
1617 		default:
1618 			/* XXX */
1619 			printf("ttyrub: would panic c = %d, val = %d\n",
1620 				c, partab[c&=0377]&077);
1621 			/*panic("ttyrub");*/
1622 		}
1623 	} else if (tp->t_lflag&ECHOPRT) {
1624 		if ((tp->t_state&TS_ERASE) == 0) {
1625 			(void) ttyoutput('\\', tp);
1626 			tp->t_state |= TS_ERASE;
1627 		}
1628 		ttyecho(c, tp);
1629 	} else
1630 		ttyecho(tp->t_cc[VERASE], tp);
1631 	tp->t_rocount--;
1632 }
1633 
1634 /*
1635  * Crt back over cnt chars perhaps
1636  * erasing them.
1637  */
1638 ttyrubo(tp, cnt)
1639 	register struct tty *tp;
1640 	int cnt;
1641 {
1642 
1643 	while (--cnt >= 0)
1644 		ttyoutstr("\b \b", tp);
1645 }
1646 
1647 /*
1648  * Reprint the rawq line.
1649  * We assume c_cc has already been checked.
1650  */
1651 ttyretype(tp)
1652 	register struct tty *tp;
1653 {
1654 	register char *cp;
1655 	char *nextc();
1656 	int s, c;
1657 
1658 	if (tp->t_cc[VREPRINT] != _POSIX_VDISABLE)
1659 		ttyecho(tp->t_cc[VREPRINT], tp);
1660 	(void) ttyoutput('\n', tp);
1661 	s = spltty();
1662 	/*** XXX *** FIX *** NEXTC IS BROKEN - DOESN'T CHECK QUOTE
1663 	  BIT OF FIRST CHAR ****/
1664 	for (cp = tp->t_canq.c_cf, c=(cp?*cp:0); cp; cp = nextc(&tp->t_canq, cp, &c)) {
1665 		ttyecho(c, tp);
1666 	}
1667 	for (cp = tp->t_rawq.c_cf, c=(cp?*cp:0); cp; cp = nextc(&tp->t_rawq, cp, &c)) {
1668 		ttyecho(c, tp);
1669 	}
1670 	tp->t_state &= ~TS_ERASE;
1671 	splx(s);
1672 	tp->t_rocount = tp->t_rawq.c_cc;
1673 	tp->t_rocol = 0;
1674 }
1675 
1676 /*
1677  * Echo a typed character to the terminal.
1678  */
1679 ttyecho(c, tp)
1680 	register c;
1681 	register struct tty *tp;
1682 {
1683 	if ((tp->t_state&TS_CNTTB) == 0)
1684 		tp->t_lflag &= ~FLUSHO;
1685 	if (((tp->t_lflag&ECHO) == 0 && ((tp->t_lflag&ECHONL) == 0 ||
1686 					  c == '\n')) || (tp->t_lflag&EXTPROC))
1687 		return;
1688 	if (tp->t_lflag&ECHOCTL) {
1689 		if ((c&TTY_CHARMASK) <= 037 && c != '\t' && c != '\n' ||
1690 		    c == 0177) {
1691 			(void) ttyoutput('^', tp);
1692 			c &= TTY_CHARMASK;
1693 			if (c == 0177)
1694 				c = '?';
1695 			else
1696 				c += 'A' - 1;
1697 		}
1698 	}
1699 	(void) ttyoutput(c, tp);
1700 }
1701 
1702 /*
1703  * send string cp to tp
1704  */
1705 ttyoutstr(cp, tp)
1706 	register char *cp;
1707 	register struct tty *tp;
1708 {
1709 	register char c;
1710 
1711 	while (c = *cp++)
1712 		(void) ttyoutput(c, tp);
1713 }
1714 
1715 ttwakeup(tp)
1716 	struct tty *tp;
1717 {
1718 
1719 	if (tp->t_rsel) {
1720 		selwakeup(tp->t_rsel, tp->t_state&TS_RCOLL);
1721 		tp->t_state &= ~TS_RCOLL;
1722 		tp->t_rsel = 0;
1723 	}
1724 	if (tp->t_state & TS_ASYNC)
1725 		pgsignal(tp->t_pgrp, SIGIO, 1);
1726 	wakeup((caddr_t)&tp->t_rawq);
1727 }
1728 
1729 /*
1730  * set tty hi and low water marks
1731  *
1732  * Try to arrange the dynamics so there's about one second
1733  * from hi to low water.
1734  *
1735  */
1736 ttsetwater(tp)
1737 	struct tty *tp;
1738 {
1739 	register cps = tp->t_ospeed / 10;
1740 	register x;
1741 
1742 #define clamp(x, h, l) ((x)>h ? h : ((x)<l) ? l : (x))
1743 	tp->t_lowat = x = clamp(cps/2, TTMAXLOWAT, TTMINLOWAT);
1744 	x += cps;
1745 	x = clamp(x, TTMAXHIWAT, TTMINHIWAT);
1746 	tp->t_hiwat = roundup(x, CBSIZE);
1747 #undef clamp
1748 }
1749 
1750 ttspeedtab(speed, table)
1751 	struct speedtab table[];
1752 {
1753 	register int i;
1754 
1755 	for (i = 0; table[i].sp_speed != -1; i++)
1756 		if (table[i].sp_speed == speed)
1757 			return(table[i].sp_code);
1758 	return(-1);
1759 }
1760 
1761 int ttyhostname = 0;
1762 /*
1763  * (^T)
1764  * Report on state of foreground process group.
1765  */
1766 ttyinfo(tp)
1767 	struct tty *tp;
1768 {
1769 	register struct proc *p, *pick = NULL;
1770 	register char *cp = hostname;
1771 	int x, s;
1772 	struct timeval utime, stime;
1773 #define	pgtok(a)	(((a)*NBPG)/1024)
1774 
1775 	if (ttycheckoutq(tp,0) == 0)
1776 		return;
1777 	/*
1778 	 * hostname
1779 	 */
1780 	if (ttyhostname) {
1781 		if (*cp == '\0')
1782 			ttyprintf(tp, "amnesia");
1783 		else
1784 			while (*cp && *cp != '.')
1785 				tputchar(*cp++, tp);
1786 		tputchar(' ');
1787 	}
1788 	/*
1789 	 * load average
1790 	 */
1791 	x = (averunnable[0] * 100 + FSCALE/2) >> FSHIFT;
1792 	ttyprintf(tp, "load: %d.", x/100);
1793 	ttyoutint(x%100, 10, 2, tp);
1794 	if (tp->t_session == NULL)
1795 		ttyprintf(tp, " not a controlling terminal\n");
1796 	else if (tp->t_pgrp == NULL)
1797 		ttyprintf(tp, " no foreground process group\n");
1798 	else if ((p = tp->t_pgrp->pg_mem) == NULL)
1799 		ttyprintf(tp, " empty foreground process group\n");
1800 	else {
1801 		/* pick interesting process */
1802 		for (; p != NULL; p = p->p_pgrpnxt) {
1803 			if (proc_compare(pick, p))
1804 				pick = p;
1805 		}
1806 		ttyprintf(tp, "  cmd: %s %d [%s] ",
1807 			pick->p_comm, pick->p_pid,
1808 			pick->p_wmesg ? pick->p_wmesg : "running");
1809 		/*
1810 		 * cpu time
1811 		 */
1812 		if (u.u_procp == pick)
1813 			s = splclock();
1814 		utime = pick->p_utime;
1815 		stime = pick->p_stime;
1816 		if (u.u_procp == pick)
1817 			splx(s);
1818 		/* user time */
1819 		x = (utime.tv_usec + 5000) / 10000; /* scale to 100's */
1820 		ttyoutint(utime.tv_sec, 10, 1, tp);
1821 		tputchar('.', tp);
1822 		ttyoutint(x, 10, 2, tp);
1823 		tputchar('u', tp);
1824 		tputchar(' ', tp);
1825 		/* system time */
1826 		x = (stime.tv_usec + 5000) / 10000; /* scale to 100's */
1827 		ttyoutint(stime.tv_sec, 10, 1, tp);
1828 		tputchar('.', tp);
1829 		ttyoutint(x, 10, 2, tp);
1830 		tputchar('s', tp);
1831 		tputchar(' ', tp);
1832 		/*
1833 		 * pctcpu
1834 		 */
1835 		x = pick->p_pctcpu * 10000 + FSCALE/2 >> FSHIFT;
1836 		ttyoutint(x/100, 10, 1, tp);
1837 #ifdef notdef	/* do we really want this ??? */
1838 		tputchar('.', tp);
1839 		ttyoutint(x%100, 10, 2, tp);
1840 #endif
1841 		ttyprintf(tp, "%% %dk\n", pgtok(pick->p_ssize + pick->p_dsize));
1842 	}
1843 	tp->t_rocount = 0;	/* so pending input will be retyped if BS */
1844 }
1845 
1846 ttyoutint(n, base, min, tp)
1847 	register int n, base, min;
1848 	register struct tty *tp;
1849 {
1850 	char info[16];
1851 	register char *p = info;
1852 
1853 	while (--min >= 0 || n) {
1854 		*p++ = "0123456789abcdef"[n%base];
1855 		n /= base;
1856 	}
1857 	while (p > info)
1858 		ttyoutput(*--p, tp);
1859 }
1860 
1861 /*
1862  * Returns 1 if p2 is "better" than p1
1863  *
1864  * The algorithm for picking the "interesting" process is thus:
1865  *
1866  *	1) (Only foreground processes are eligable - implied)
1867  *	2) Runnable processes are favored over anything
1868  *	   else.  The runner with the highest cpu
1869  *	   utilization is picked (p_cpu).  Ties are
1870  *	   broken by picking the highest pid.
1871  *	3  Next, the sleeper with the shortest sleep
1872  *	   time is favored.  With ties, we pick out
1873  *	   just "short-term" sleepers (SSINTR == 0).
1874  *	   Further ties are broken by picking the highest
1875  *	   pid.
1876  *
1877  */
1878 #define isrun(p)	(((p)->p_stat == SRUN) || ((p)->p_stat == SIDL))
1879 proc_compare(p1, p2)
1880 	register struct proc *p1, *p2;
1881 {
1882 
1883 	if (p1 == NULL)
1884 		return (1);
1885 	/*
1886 	 * see if at least one of them is runnable
1887 	 */
1888 	switch (isrun(p1)<<1 | isrun(p2)) {
1889 	case 0x01:
1890 		return (1);
1891 	case 0x10:
1892 		return (0);
1893 	case 0x11:
1894 		/*
1895 		 * tie - favor one with highest recent cpu utilization
1896 		 */
1897 		if (p2->p_cpu > p1->p_cpu)
1898 			return (1);
1899 		if (p1->p_cpu > p2->p_cpu)
1900 			return (0);
1901 		return (p2->p_pid > p1->p_pid);	/* tie - return highest pid */
1902 	}
1903 	/*
1904 	 * pick the one with the smallest sleep time
1905 	 */
1906 	if (p2->p_slptime > p1->p_slptime)
1907 		return (0);
1908 	if (p1->p_slptime > p2->p_slptime)
1909 		return (1);
1910 	/*
1911 	 * favor one sleeping in a non-interruptible sleep
1912 	 */
1913 	if (p1->p_flag&SSINTR && (p2->p_flag&SSINTR) == 0)
1914 		return (1);
1915 	if (p2->p_flag&SSINTR && (p1->p_flag&SSINTR) == 0)
1916 		return (0);
1917 	return(p2->p_pid > p1->p_pid);		/* tie - return highest pid */
1918 }
1919 #define TOTTY	0x2	/* XXX should be in header */
1920 /*VARARGS2*/
1921 ttyprintf(tp, fmt, x1)
1922 	struct tty *tp;
1923 	char *fmt;
1924 	unsigned x1;
1925 {
1926 	prf(fmt, &x1, TOTTY, (caddr_t)tp);
1927 }
1928 
1929 /*
1930  * Output char to tty; console putchar style.
1931  */
1932 tputchar(c, tp)
1933 	int c;
1934 	struct tty *tp;
1935 {
1936 	register s = spltty();
1937 
1938 	if ((tp->t_state & (TS_CARR_ON | TS_ISOPEN))
1939 	    == (TS_CARR_ON | TS_ISOPEN)) {
1940 		if (c == '\n')
1941 			(void) ttyoutput('\r', tp);
1942 		(void) ttyoutput(c, tp);
1943 		ttstart(tp);
1944 		splx(s);
1945 		return (0);
1946 	}
1947 	splx(s);
1948 	return (-1);
1949 }
1950 
1951 ttysleep(tp, chan, pri, wmesg, timo)
1952 	struct tty *tp;
1953 	caddr_t chan;
1954 	int pri;
1955 	char *wmesg;
1956 	int timo;
1957 {
1958 	int error;
1959 	short gen = tp->t_gen;
1960 
1961 	if (error = tsleep(chan, pri, wmesg, timo))
1962 		return (error);
1963 	if (tp->t_gen != gen)
1964 		return (ERESTART);
1965 	return (0);
1966 }
1967