xref: /csrg-svn/sys/kern/tty.c (revision 42882)
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	7.28 (Berkeley) 06/05/90
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 = tsleep((caddr_t)&tp->t_outq, TTOPRI | PCATCH,
124 		    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 = tsleep((caddr_t)&lbolt, TTOPRI | PCATCH,
268 			    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 		return(ttcompat(tp, com, data, flag));
550 #endif
551 
552 	default:
553 		return (-1);
554 	}
555 	return (0);
556 }
557 
558 ttnread(tp)
559 	struct tty *tp;
560 {
561 	int nread = 0;
562 
563 	if (tp->t_lflag & PENDIN)
564 		ttypend(tp);
565 	nread = tp->t_canq.c_cc;
566 	if ((tp->t_lflag & ICANON) == 0)
567 		nread += tp->t_rawq.c_cc;
568 	return (nread);
569 }
570 
571 ttselect(dev, rw)
572 	dev_t dev;
573 	int rw;
574 {
575 	register struct tty *tp = &cdevsw[major(dev)].d_ttys[minor(dev)];
576 	int nread;
577 	int s = spltty();
578 
579 	switch (rw) {
580 
581 	case FREAD:
582 		nread = ttnread(tp);
583 		if (nread > 0 ||
584 		   ((tp->t_cflag&CLOCAL) == 0 && (tp->t_state&TS_CARR_ON) == 0))
585 			goto win;
586 		if (tp->t_rsel && tp->t_rsel->p_wchan == (caddr_t)&selwait)
587 			tp->t_state |= TS_RCOLL;
588 		else
589 			tp->t_rsel = u.u_procp;
590 		break;
591 
592 	case FWRITE:
593 		if (tp->t_outq.c_cc <= tp->t_lowat)
594 			goto win;
595 		if (tp->t_wsel && tp->t_wsel->p_wchan == (caddr_t)&selwait)
596 			tp->t_state |= TS_WCOLL;
597 		else
598 			tp->t_wsel = u.u_procp;
599 		break;
600 	}
601 	splx(s);
602 	return (0);
603 win:
604 	splx(s);
605 	return (1);
606 }
607 
608 /*
609  * Initial open of tty, or (re)entry to line discipline.
610  */
611 ttyopen(dev, tp)
612 	dev_t dev;
613 	register struct tty *tp;
614 {
615 
616 	tp->t_dev = dev;
617 
618 	tp->t_state &= ~TS_WOPEN;
619 	if ((tp->t_state & TS_ISOPEN) == 0) {
620 		tp->t_state |= TS_ISOPEN;
621 		bzero((caddr_t)&tp->t_winsize, sizeof(tp->t_winsize));
622 	}
623 	return (0);
624 }
625 
626 /*
627  * "close" a line discipline
628  */
629 ttylclose(tp)
630 	register struct tty *tp;
631 {
632 
633 	ttywflush(tp);
634 }
635 
636 /*
637  * clean tp on last close
638  */
639 ttyclose(tp)
640 	register struct tty *tp;
641 {
642 	if (constty == tp)
643 		constty = NULL;
644 	ttyflush(tp, FREAD|FWRITE);
645 	tp->t_session = NULL;
646 	tp->t_pgrp = NULL;
647 	tp->t_state = 0;
648 	return (0);
649 }
650 
651 /*
652  * Handle modem control transition on a tty.
653  * Flag indicates new state of carrier.
654  * Returns 0 if the line should be turned off, otherwise 1.
655  */
656 ttymodem(tp, flag)
657 	register struct tty *tp;
658 {
659 
660 	if ((tp->t_state&TS_WOPEN) == 0 && (tp->t_lflag&MDMBUF)) {
661 		/*
662 		 * MDMBUF: do flow control according to carrier flag
663 		 */
664 		if (flag) {
665 			tp->t_state &= ~TS_TTSTOP;
666 			ttstart(tp);
667 		} else if ((tp->t_state&TS_TTSTOP) == 0) {
668 			tp->t_state |= TS_TTSTOP;
669 			(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
670 		}
671 	} else if (flag == 0) {
672 		/*
673 		 * Lost carrier.
674 		 */
675 		tp->t_state &= ~TS_CARR_ON;
676 		if (tp->t_state&TS_ISOPEN && (tp->t_cflag&CLOCAL) == 0) {
677 			if (tp->t_session && tp->t_session->s_leader)
678 				psignal(tp->t_session->s_leader, SIGHUP);
679 			ttyflush(tp, FREAD|FWRITE);
680 			return (0);
681 		}
682 	} else {
683 		/*
684 		 * Carrier now on.
685 		 */
686 		tp->t_state |= TS_CARR_ON;
687 		ttwakeup(tp);
688 	}
689 	return (1);
690 }
691 
692 /*
693  * Default modem control routine (for other line disciplines).
694  * Return argument flag, to turn off device on carrier drop.
695  */
696 nullmodem(tp, flag)
697 	register struct tty *tp;
698 	int flag;
699 {
700 
701 	if (flag)
702 		tp->t_state |= TS_CARR_ON;
703 	else {
704 		tp->t_state &= ~TS_CARR_ON;
705 		if ((tp->t_cflag&CLOCAL) == 0) {
706 			if (tp->t_session && tp->t_session->s_leader)
707 				psignal(tp->t_session->s_leader, SIGHUP);
708 			return (0);
709 		}
710 	}
711 	return (1);
712 }
713 
714 /*
715  * reinput pending characters after state switch
716  * call at spltty().
717  */
718 ttypend(tp)
719 	register struct tty *tp;
720 {
721 	struct clist tq;
722 	register c;
723 
724 	tp->t_lflag &= ~PENDIN;
725 	tp->t_state |= TS_TYPEN;
726 	tq = tp->t_rawq;
727 	tp->t_rawq.c_cc = 0;
728 	tp->t_rawq.c_cf = tp->t_rawq.c_cl = 0;
729 	while ((c = getc(&tq)) >= 0)
730 		ttyinput(c, tp);
731 	tp->t_state &= ~TS_TYPEN;
732 }
733 
734 /*
735  *
736  * Place a character on raw TTY input queue,
737  * putting in delimiters and waking up top
738  * half as needed.  Also echo if required.
739  * The arguments are the character and the
740  * appropriate tty structure.
741  */
742 ttyinput(c, tp)
743 	register c;
744 	register struct tty *tp;
745 {
746 	register int iflag = tp->t_iflag;
747 	register int lflag = tp->t_lflag;
748 	register u_char *cc = tp->t_cc;
749 	int i, err;
750 
751 	/*
752 	 * If input is pending take it first.
753 	 */
754 	if (lflag&PENDIN)
755 		ttypend(tp);
756 	/*
757 	 * Gather stats.
758 	 */
759 	tk_nin++;
760 	if (lflag&ICANON) {
761 		tk_cancc++;
762 		tp->t_cancc++;
763 	} else {
764 		tk_rawcc++;
765 		tp->t_rawcc++;
766 	}
767 	/*
768 	 * Handle exceptional conditions (break, parity, framing).
769 	 */
770 	if (err = (c&TTY_ERRORMASK)) {
771 		c &= ~TTY_ERRORMASK;
772 		if (err&TTY_FE && !c) {		/* break */
773 			if (iflag&IGNBRK)
774 				goto endcase;
775 			else if (iflag&BRKINT && lflag&ISIG &&
776 				(cc[VINTR] != _POSIX_VDISABLE))
777 				c = cc[VINTR];
778 			else {
779 				c = 0;
780 				if (iflag&PARMRK)
781 					goto parmrk;
782 			}
783 		} else if ((err&TTY_PE && iflag&INPCK) || err&TTY_FE) {
784 			if (iflag&IGNPAR)
785 				goto endcase;
786 			else if (iflag&PARMRK) {
787 parmrk:
788 				putc(0377|TTY_QUOTE, &tp->t_rawq);
789 				putc(0|TTY_QUOTE, &tp->t_rawq);
790 				putc(c|TTY_QUOTE, &tp->t_rawq);
791 				goto endcase;
792 			} else
793 				c = 0;
794 		}
795 	}
796 	/*
797 	 * In tandem mode, check high water mark.
798 	 */
799 	if (iflag&IXOFF)
800 		ttyblock(tp);
801 	if ((tp->t_state&TS_TYPEN) == 0 && (iflag&ISTRIP))
802 		c &= 0177;
803     if ((tp->t_lflag&EXTPROC) == 0) {
804 	/*
805 	 * Check for literal nexting very first
806 	 */
807 	if (tp->t_state&TS_LNCH) {
808 		c |= TTY_QUOTE;
809 		tp->t_state &= ~TS_LNCH;
810 	}
811 	/*
812 	 * Scan for special characters.  This code
813 	 * is really just a big case statement with
814 	 * non-constant cases.  The bottom of the
815 	 * case statement is labeled ``endcase'', so goto
816 	 * it after a case match, or similar.
817 	 */
818 	/*
819 	 * Control chars which aren't controlled
820 	 * by ICANON, ISIG, or IXON.
821 	 */
822 	if (lflag&IEXTEN) {
823 		if (CCEQ(cc[VLNEXT], c)) {
824 			if (lflag&ECHO) {
825 				if (lflag&ECHOE)
826 					ttyoutstr("^\b", tp);
827 				else
828 					ttyecho(c, tp);
829 			}
830 			tp->t_state |= TS_LNCH;
831 			goto endcase;
832 		}
833 		if (CCEQ(cc[VFLUSHO], c)) {
834 			if (lflag&FLUSHO)
835 				tp->t_lflag &= ~FLUSHO;
836 			else {
837 				ttyflush(tp, FWRITE);
838 				ttyecho(c, tp);
839 				if (tp->t_rawq.c_cc + tp->t_canq.c_cc)
840 					ttyretype(tp);
841 				tp->t_lflag |= FLUSHO;
842 			}
843 			goto startoutput;
844 		}
845 	}
846 	/*
847 	 * Signals.
848 	 */
849 	if (lflag&ISIG) {
850 		if (CCEQ(cc[VINTR], c) || CCEQ(cc[VQUIT], c)) {
851 			if ((lflag&NOFLSH) == 0)
852 				ttyflush(tp, FREAD|FWRITE);
853 			ttyecho(c, tp);
854 			pgsignal(tp->t_pgrp,
855 			    CCEQ(cc[VINTR], c) ? SIGINT : SIGQUIT, 1);
856 			goto endcase;
857 		}
858 		if (CCEQ(cc[VSUSP], c)) {
859 			if ((lflag&NOFLSH) == 0)
860 				ttyflush(tp, FREAD);
861 			ttyecho(c, tp);
862 			pgsignal(tp->t_pgrp, SIGTSTP, 1);
863 			goto endcase;
864 		}
865 	}
866 	/*
867 	 * Handle start/stop characters.
868 	 */
869 	if (iflag&IXON) {
870 		if (CCEQ(cc[VSTOP], c)) {
871 			if ((tp->t_state&TS_TTSTOP) == 0) {
872 				tp->t_state |= TS_TTSTOP;
873 				(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
874 				return;
875 			}
876 			if (!CCEQ(cc[VSTART], c))
877 				return;
878 			/*
879 			 * if VSTART == VSTOP then toggle
880 			 */
881 			goto endcase;
882 		}
883 		if (CCEQ(cc[VSTART], c))
884 			goto restartoutput;
885 	}
886 	/*
887 	 * IGNCR, ICRNL, & INLCR
888 	 */
889 	if (c == '\r') {
890 		if (iflag&IGNCR)
891 			goto endcase;
892 		else if (iflag&ICRNL)
893 			c = '\n';
894 	}
895 	else if (c == '\n' && iflag&INLCR)
896 		c = '\r';
897     }
898 	/*
899 	 * Non canonical mode; don't process line editing
900 	 * characters; check high water mark for wakeup.
901 	 *
902 	 */
903 	if ((lflag&ICANON) == 0) {
904 		if (tp->t_rawq.c_cc > TTYHOG) {
905 			if (iflag&IMAXBEL) {
906 				if (tp->t_outq.c_cc < tp->t_hiwat)
907 					(void) ttyoutput(CTRL('g'), tp);
908 			} else
909 				ttyflush(tp, FREAD | FWRITE);
910 		} else {
911 			if (putc(c, &tp->t_rawq) >= 0) {
912 				ttwakeup(tp);
913 				ttyecho(c, tp);
914 			}
915 		}
916 		goto endcase;
917 	}
918     if ((tp->t_lflag&EXTPROC) == 0) {
919 	/*
920 	 * From here on down canonical mode character
921 	 * processing takes place.
922 	 */
923 	/*
924 	 * erase (^H / ^?)
925 	 */
926 	if (CCEQ(cc[VERASE], c)) {
927 		if (tp->t_rawq.c_cc)
928 			ttyrub(unputc(&tp->t_rawq), tp);
929 		goto endcase;
930 	}
931 	/*
932 	 * kill (^U)
933 	 */
934 	if (CCEQ(cc[VKILL], c)) {
935 		if (lflag&ECHOKE && tp->t_rawq.c_cc == tp->t_rocount &&
936 		    (lflag&ECHOPRT) == 0) {
937 			while (tp->t_rawq.c_cc)
938 				ttyrub(unputc(&tp->t_rawq), tp);
939 		} else {
940 			ttyecho(c, tp);
941 			if (lflag&ECHOK || lflag&ECHOKE)
942 				ttyecho('\n', tp);
943 			while (getc(&tp->t_rawq) > 0)
944 				;
945 			tp->t_rocount = 0;
946 		}
947 		tp->t_state &= ~TS_LOCAL;
948 		goto endcase;
949 	}
950 	/*
951 	 * word erase (^W)
952 	 */
953 	if (CCEQ(cc[VWERASE], c)) {
954 		int ctype;
955 
956 #define CTYPE(c) ((lflag&ALTWERASE) ? (partab[(c)&TTY_CHARMASK]&0100) : 0)
957 		/*
958 		 * erase whitespace
959 		 */
960 		while ((c = unputc(&tp->t_rawq)) == ' ' || c == '\t')
961 			ttyrub(c, tp);
962 		if (c == -1)
963 			goto endcase;
964 		/*
965 		 * special case last char of token
966 		 */
967 		ttyrub(c, tp);
968 		c = unputc(&tp->t_rawq);
969 		if (c == -1 || c == ' ' || c == '\t') {
970 			if (c != -1)
971 				(void) putc(c, &tp->t_rawq);
972 			goto endcase;
973 		}
974 		/*
975 		 * erase rest of token
976 		 */
977 		ctype = CTYPE(c);
978 		do {
979 			ttyrub(c, tp);
980 			c = unputc(&tp->t_rawq);
981 			if (c == -1)
982 				goto endcase;
983 		} while (c != ' ' && c != '\t' && CTYPE(c) == ctype);
984 		(void) putc(c, &tp->t_rawq);
985 		goto endcase;
986 #undef CTYPE
987 	}
988 	/*
989 	 * reprint line (^R)
990 	 */
991 	if (CCEQ(cc[VREPRINT], c)) {
992 		ttyretype(tp);
993 		goto endcase;
994 	}
995 	if (CCEQ(cc[VINFO], c)) {
996 		pgsignal(tp->t_pgrp, SIGINFO, 1);
997 		if ((lflag&NOKERNINFO) == 0)
998 			ttyinfo(tp);
999 		goto endcase;
1000 	}
1001     }
1002 	/*
1003 	 * Check for input buffer overflow
1004 	 */
1005 	if (tp->t_rawq.c_cc+tp->t_canq.c_cc >= TTYHOG) {
1006 		if (iflag&IMAXBEL) {
1007 			if (tp->t_outq.c_cc < tp->t_hiwat)
1008 				(void) ttyoutput(CTRL('g'), tp);
1009 		} else
1010 			ttyflush(tp, FREAD | FWRITE);
1011 		goto endcase;
1012 	}
1013 	/*
1014 	 * Put data char in q for user and
1015 	 * wakeup on seeing a line delimiter.
1016 	 */
1017 	if (putc(c, &tp->t_rawq) >= 0) {
1018 		if (ttbreakc(c)) {
1019 			tp->t_rocount = 0;
1020 			catq(&tp->t_rawq, &tp->t_canq);
1021 			ttwakeup(tp);
1022 		} else if (tp->t_rocount++ == 0)
1023 			tp->t_rocol = tp->t_col;
1024 		if (tp->t_state&TS_ERASE) {
1025 			/*
1026 			 * end of prterase \.../
1027 			 */
1028 			tp->t_state &= ~TS_ERASE;
1029 			(void) ttyoutput('/', tp);
1030 		}
1031 		i = tp->t_col;
1032 		ttyecho(c, tp);
1033 		if (CCEQ(cc[VEOF], c) && lflag&ECHO) {
1034 			/*
1035 			 * Place the cursor over the '^' of the ^D.
1036 			 */
1037 			i = MIN(2, tp->t_col - i);
1038 			while (i > 0) {
1039 				(void) ttyoutput('\b', tp);
1040 				i--;
1041 			}
1042 		}
1043 	}
1044 endcase:
1045 	/*
1046 	 * IXANY means allow any character to restart output.
1047 	 */
1048 	if ((tp->t_state&TS_TTSTOP) && (iflag&IXANY) == 0 &&
1049 	    cc[VSTART] != cc[VSTOP])
1050 		return;
1051 restartoutput:
1052 	tp->t_state &= ~TS_TTSTOP;
1053 	tp->t_lflag &= ~FLUSHO;
1054 startoutput:
1055 	ttstart(tp);
1056 }
1057 
1058 /*
1059  * Put character on TTY output queue, adding delays,
1060  * expanding tabs, and handling the CR/NL bit.
1061  * This is called both from the top half for output,
1062  * and from interrupt level for echoing.
1063  * The arguments are the character and the tty structure.
1064  * Returns < 0 if putc succeeds, otherwise returns char to resend
1065  * Must be recursive.
1066  */
1067 ttyoutput(c, tp)
1068 	register c;
1069 	register struct tty *tp;
1070 {
1071 	register char *colp;
1072 	register ctype;
1073 	register long oflag = tp->t_oflag;
1074 
1075 	if ((oflag&OPOST) == 0) {
1076 		if (tp->t_lflag&FLUSHO)
1077 			return (-1);
1078 		if (putc(c, &tp->t_outq))
1079 			return (c);
1080 		tk_nout++;
1081 		tp->t_outcc++;
1082 		return (-1);
1083 	}
1084 	c &= TTY_CHARMASK;
1085 	/*
1086 	 * Turn tabs to spaces as required
1087 	 *
1088 	 * Special case if we have external processing, we don't
1089 	 * do the tab expansion because we'll probably get it
1090 	 * wrong.  If tab expansion needs to be done, let it
1091 	 * happen externally.
1092 	 */
1093 	if ((tp->t_lflag&EXTPROC) == 0 &&
1094 	    c == '\t' && oflag&OXTABS ) {
1095 		register int s;
1096 
1097 		c = 8 - (tp->t_col&7);
1098 		if ((tp->t_lflag&FLUSHO) == 0) {
1099 			s = spltty();		/* don't interrupt tabs */
1100 			c -= b_to_q("        ", c, &tp->t_outq);
1101 			tk_nout += c;
1102 			tp->t_outcc += c;
1103 			splx(s);
1104 		}
1105 		tp->t_col += c;
1106 		return (c ? -1 : '\t');
1107 	}
1108 	if (c == CEOT && oflag&ONOEOT)
1109 		return(-1);
1110 	tk_nout++;
1111 	tp->t_outcc++;
1112 	/*
1113 	 * turn <nl> to <cr><lf> if desired.
1114 	 */
1115 	if (c == '\n' && (tp->t_oflag&ONLCR) && ttyoutput('\r', tp) >= 0)
1116 		return (c);
1117 	if ((tp->t_lflag&FLUSHO) == 0 && putc(c, &tp->t_outq))
1118 		return (c);
1119 	/*
1120 	 * Calculate delays.
1121 	 * The numbers here represent clock ticks
1122 	 * and are not necessarily optimal for all terminals.
1123 	 *
1124 	 * SHOULD JUST ALLOW USER TO SPECIFY DELAYS
1125 	 *
1126 	 * (actually, should THROW AWAY terminals which need delays)
1127 	 */
1128 	colp = &tp->t_col;
1129 	ctype = partab[c];
1130 	c = 0;
1131 	switch (ctype&077) {
1132 
1133 	case ORDINARY:
1134 		(*colp)++;
1135 
1136 	case CONTROL:
1137 		break;
1138 
1139 	case BACKSPACE:
1140 		if (*colp)
1141 			(*colp)--;
1142 		break;
1143 
1144 	/*
1145 	 * This macro is close enough to the correct thing;
1146 	 * it should be replaced by real user settable delays
1147 	 * in any event...
1148 	 */
1149 #define	mstohz(ms)	(((ms) * hz) >> 10)
1150 	case NEWLINE:
1151 		ctype = (tp->t_flags >> 8) & 03;
1152 		if (ctype == 1) { /* tty 37 */
1153 			if (*colp > 0) {
1154 				c = (((unsigned)*colp) >> 4) + 3;
1155 				if ((unsigned)c > 6)
1156 					c = 6;
1157 			}
1158 		} else if (ctype == 2) /* vt05 */
1159 			c = mstohz(100);
1160 		*colp = 0;
1161 		break;
1162 
1163 	case TAB:
1164 		ctype = (tp->t_flags >> 10) & 03;
1165 		if (ctype == 1) { /* tty 37 */
1166 			c = 1 - (*colp | ~07);
1167 			if (c < 5)
1168 				c = 0;
1169 		}
1170 		*colp |= 07;
1171 		(*colp)++;
1172 		break;
1173 
1174 	case VTAB:
1175 		if (tp->t_flags&VTDELAY) /* tty 37 */
1176 			c = 0177;
1177 		break;
1178 
1179 	case RETURN:
1180 		ctype = (tp->t_flags >> 12) & 03;
1181 		if (ctype == 1) /* tn 300 */
1182 			c = mstohz(83);
1183 		else if (ctype == 2) /* ti 700 */
1184 			c = mstohz(166);
1185 		else if (ctype == 3) { /* concept 100 */
1186 			int i;
1187 
1188 			if ((i = *colp) >= 0)
1189 				for (; i < 9; i++)
1190 					(void) putc(0177, &tp->t_outq);
1191 		}
1192 		*colp = 0;
1193 	}
1194 	if (c && (tp->t_lflag&FLUSHO) == 0)
1195 		(void) putc(c|TTY_QUOTE, &tp->t_outq);
1196 	return (-1);
1197 }
1198 #undef mstohz
1199 
1200 /*
1201  * Called from device's read routine after it has
1202  * calculated the tty-structure given as argument.
1203  */
1204 ttread(tp, uio, flag)
1205 	register struct tty *tp;
1206 	struct uio *uio;
1207 {
1208 	register struct clist *qp;
1209 	register int c;
1210 	register long lflag;
1211 	register u_char *cc = tp->t_cc;
1212 	int s, first, error = 0;
1213 
1214 loop:
1215 	lflag = tp->t_lflag;
1216 	s = spltty();
1217 	/*
1218 	 * take pending input first
1219 	 */
1220 	if (lflag&PENDIN)
1221 		ttypend(tp);
1222 	splx(s);
1223 
1224 	/*
1225 	 * Hang process if it's in the background.
1226 	 */
1227 	if (isbackground(u.u_procp, tp)) {
1228 		if ((u.u_procp->p_sigignore & sigmask(SIGTTIN)) ||
1229 		   (u.u_procp->p_sigmask & sigmask(SIGTTIN)) ||
1230 		    u.u_procp->p_flag&SVFORK || u.u_procp->p_pgrp->pg_jobc == 0)
1231 			return (EIO);
1232 		pgsignal(u.u_procp->p_pgrp, SIGTTIN, 1);
1233 		if (error = tsleep((caddr_t)&lbolt, TTIPRI | PCATCH, ttybg, 0))
1234 			return (error);
1235 		goto loop;
1236 	}
1237 
1238 	/*
1239 	 * If canonical, use the canonical queue,
1240 	 * else use the raw queue.
1241 	 *
1242 	 * XXX - should get rid of canonical queue.
1243 	 * (actually, should get rid of clists...)
1244 	 */
1245 	qp = lflag&ICANON ? &tp->t_canq : &tp->t_rawq;
1246 
1247 	/*
1248 	 * If there is no input, sleep on rawq
1249 	 * awaiting hardware receipt and notification.
1250 	 * If we have data, we don't need to check for carrier.
1251 	 */
1252 	s = spltty();
1253 	if (qp->c_cc <= 0) {
1254 		int carrier;
1255 
1256 		carrier = (tp->t_state&TS_CARR_ON) || (tp->t_cflag&CLOCAL);
1257 		if (!carrier && tp->t_state&TS_ISOPEN) {
1258 			splx(s);
1259 			return (0);	/* EOF */
1260 		}
1261 		if (flag & IO_NDELAY) {
1262 			splx(s);
1263 			return (EWOULDBLOCK);
1264 		}
1265 		error = tsleep((caddr_t)&tp->t_rawq, TTIPRI | PCATCH,
1266 		    carrier ? ttyin : ttopen, 0);
1267 		splx(s);
1268 		if (error)
1269 			return (error);
1270 		goto loop;
1271 	}
1272 	splx(s);
1273 
1274 	/*
1275 	 * Input present, check for input mapping and processing.
1276 	 */
1277 	first = 1;
1278 	while ((c = getc(qp)) >= 0) {
1279 		/*
1280 		 * delayed suspend (^Y)
1281 		 */
1282 		if (CCEQ(cc[VDSUSP], c) && lflag&ISIG) {
1283 			pgsignal(tp->t_pgrp, SIGTSTP, 1);
1284 			if (first) {
1285 				if (error = tsleep((caddr_t)&lbolt,
1286 				    TTIPRI | PCATCH, ttybg, 0))
1287 					break;
1288 				goto loop;
1289 			}
1290 			break;
1291 		}
1292 		/*
1293 		 * Interpret EOF only in canonical mode.
1294 		 */
1295 		if (CCEQ(cc[VEOF], c) && lflag&ICANON)
1296 			break;
1297 		/*
1298 		 * Give user character.
1299 		 */
1300  		error = ureadc(c, uio);
1301 		if (error)
1302 			break;
1303  		if (uio->uio_resid == 0)
1304 			break;
1305 		/*
1306 		 * In canonical mode check for a "break character"
1307 		 * marking the end of a "line of input".
1308 		 */
1309 		if (lflag&ICANON && ttbreakc(c))
1310 			break;
1311 		first = 0;
1312 	}
1313 	/*
1314 	 * Look to unblock output now that (presumably)
1315 	 * the input queue has gone down.
1316 	 */
1317 	if (tp->t_state&TS_TBLOCK && tp->t_rawq.c_cc < TTYHOG/5) {
1318 		if (cc[VSTART] != _POSIX_VDISABLE
1319 		   && putc(cc[VSTART], &tp->t_outq) == 0) {
1320 			tp->t_state &= ~TS_TBLOCK;
1321 			ttstart(tp);
1322 		}
1323 	}
1324 	return (error);
1325 }
1326 
1327 /*
1328  * Check the output queue on tp for space for a kernel message
1329  * (from uprintf/tprintf).  Allow some space over the normal
1330  * hiwater mark so we don't lose messages due to normal flow
1331  * control, but don't let the tty run amok.
1332  * Sleeps here are not interruptible, but we return prematurely
1333  * if new signals come in.
1334  */
1335 ttycheckoutq(tp, wait)
1336 	register struct tty *tp;
1337 	int wait;
1338 {
1339 	int hiwat, s, oldsig;
1340 
1341 	hiwat = tp->t_hiwat;
1342 	s = spltty();
1343 	oldsig = u.u_procp->p_sig;
1344 	if (tp->t_outq.c_cc > hiwat + 200)
1345 		while (tp->t_outq.c_cc > hiwat) {
1346 			ttstart(tp);
1347 			if (wait == 0 || u.u_procp->p_sig != oldsig) {
1348 				splx(s);
1349 				return (0);
1350 			}
1351 			timeout(wakeup, (caddr_t)&tp->t_outq, hz);
1352 			tp->t_state |= TS_ASLEEP;
1353 			sleep((caddr_t)&tp->t_outq, PZERO - 1);
1354 		}
1355 	splx(s);
1356 	return (1);
1357 }
1358 
1359 /*
1360  * Called from the device's write routine after it has
1361  * calculated the tty-structure given as argument.
1362  */
1363 ttwrite(tp, uio, flag)
1364 	register struct tty *tp;
1365 	register struct uio *uio;
1366 {
1367 	register char *cp;
1368 	register int cc = 0, ce;
1369 	int i, hiwat, cnt, error, s;
1370 	char obuf[OBUFSIZ];
1371 
1372 	hiwat = tp->t_hiwat;
1373 	cnt = uio->uio_resid;
1374 	error = 0;
1375 loop:
1376 	s = spltty();
1377 	if ((tp->t_state&TS_CARR_ON) == 0 && (tp->t_cflag&CLOCAL) == 0) {
1378 		if (tp->t_state&TS_ISOPEN) {
1379 			splx(s);
1380 			return (EIO);
1381 		} else if (flag & IO_NDELAY) {
1382 			splx(s);
1383 			error = EWOULDBLOCK;
1384 			goto out;
1385 		} else {
1386 			/*
1387 			 * sleep awaiting carrier
1388 			 */
1389 			error = tsleep((caddr_t)&tp->t_rawq, TTIPRI | PCATCH,
1390 			    ttopen, 0);
1391 			splx(s);
1392 			if (error)
1393 				goto out;
1394 			goto loop;
1395 		}
1396 	}
1397 	splx(s);
1398 	/*
1399 	 * Hang the process if it's in the background.
1400 	 */
1401 	if (isbackground(u.u_procp, tp) &&
1402 	    (tp->t_lflag&TOSTOP) && (u.u_procp->p_flag&SVFORK)==0 &&
1403 	    (u.u_procp->p_sigignore & sigmask(SIGTTOU)) == 0 &&
1404 	    (u.u_procp->p_sigmask & sigmask(SIGTTOU)) == 0 &&
1405 	     u.u_procp->p_pgrp->pg_jobc) {
1406 		pgsignal(u.u_procp->p_pgrp, SIGTTOU, 1);
1407 		if (error = tsleep((caddr_t)&lbolt, TTIPRI | PCATCH, ttybg, 0))
1408 			goto out;
1409 		goto loop;
1410 	}
1411 	/*
1412 	 * Process the user's data in at most OBUFSIZ
1413 	 * chunks.  Perform any output translation.
1414 	 * Keep track of high water mark, sleep on overflow
1415 	 * awaiting device aid in acquiring new space.
1416 	 */
1417 	while (uio->uio_resid > 0 || cc > 0) {
1418 		if (tp->t_lflag&FLUSHO) {
1419 			uio->uio_resid = 0;
1420 			return (0);
1421 		}
1422 		if (tp->t_outq.c_cc > hiwat)
1423 			goto ovhiwat;
1424 		/*
1425 		 * Grab a hunk of data from the user,
1426 		 * unless we have some leftover from last time.
1427 		 */
1428 		if (cc == 0) {
1429 			cc = min(uio->uio_resid, OBUFSIZ);
1430 			cp = obuf;
1431 			error = uiomove(cp, cc, uio);
1432 			if (error) {
1433 				cc = 0;
1434 				break;
1435 			}
1436 		}
1437 		/*
1438 		 * If nothing fancy need be done, grab those characters we
1439 		 * can handle without any of ttyoutput's processing and
1440 		 * just transfer them to the output q.  For those chars
1441 		 * which require special processing (as indicated by the
1442 		 * bits in partab), call ttyoutput.  After processing
1443 		 * a hunk of data, look for FLUSHO so ^O's will take effect
1444 		 * immediately.
1445 		 */
1446 		while (cc > 0) {
1447 			if ((tp->t_oflag&OPOST) == 0)
1448 				ce = cc;
1449 			else {
1450 				ce = cc - scanc((unsigned)cc, (u_char *)cp,
1451 				   (u_char *)partab, 077);
1452 				/*
1453 				 * If ce is zero, then we're processing
1454 				 * a special character through ttyoutput.
1455 				 */
1456 				if (ce == 0) {
1457 					tp->t_rocount = 0;
1458 					if (ttyoutput(*cp, tp) >= 0) {
1459 					    /* no c-lists, wait a bit */
1460 					    ttstart(tp);
1461 					    if (error = tsleep((caddr_t)&lbolt,
1462 						TTOPRI | PCATCH, ttybuf, 0))
1463 						    break;
1464 					    goto loop;
1465 					}
1466 					cp++, cc--;
1467 					if ((tp->t_lflag&FLUSHO) ||
1468 					    tp->t_outq.c_cc > hiwat)
1469 						goto ovhiwat;
1470 					continue;
1471 				}
1472 			}
1473 			/*
1474 			 * A bunch of normal characters have been found,
1475 			 * transfer them en masse to the output queue and
1476 			 * continue processing at the top of the loop.
1477 			 * If there are any further characters in this
1478 			 * <= OBUFSIZ chunk, the first should be a character
1479 			 * requiring special handling by ttyoutput.
1480 			 */
1481 			tp->t_rocount = 0;
1482 			i = b_to_q(cp, ce, &tp->t_outq);
1483 			ce -= i;
1484 			tp->t_col += ce;
1485 			cp += ce, cc -= ce, tk_nout += ce;
1486 			tp->t_outcc += ce;
1487 			if (i > 0) {
1488 				/* out of c-lists, wait a bit */
1489 				ttstart(tp);
1490 				if (error = tsleep((caddr_t)&lbolt,
1491 				    TTOPRI | PCATCH, ttybuf, 0))
1492 					break;
1493 				goto loop;
1494 			}
1495 			if (tp->t_lflag&FLUSHO || tp->t_outq.c_cc > hiwat)
1496 				break;
1497 		}
1498 		ttstart(tp);
1499 	}
1500 out:
1501 	/*
1502 	 * If cc is nonzero, we leave the uio structure inconsistent,
1503 	 * as the offset and iov pointers have moved forward,
1504 	 * but it doesn't matter (the call will either return short
1505 	 * or restart with a new uio).
1506 	 */
1507 	uio->uio_resid += cc;
1508 	return (error);
1509 
1510 ovhiwat:
1511 	ttstart(tp);
1512 	s = spltty();
1513 	/*
1514 	 * This can only occur if FLUSHO is set in t_lflag,
1515 	 * or if ttstart/oproc is synchronous (or very fast).
1516 	 */
1517 	if (tp->t_outq.c_cc <= hiwat) {
1518 		splx(s);
1519 		goto loop;
1520 	}
1521 	if (flag & IO_NDELAY) {
1522 		splx(s);
1523 		uio->uio_resid += cc;
1524 		if (uio->uio_resid == cnt)
1525 			return (EWOULDBLOCK);
1526 		return (0);
1527 	}
1528 	tp->t_state |= TS_ASLEEP;
1529 	error = tsleep((caddr_t)&tp->t_outq, TTOPRI | PCATCH, ttyout, 0);
1530 	splx(s);
1531 	if (error)
1532 		goto out;
1533 	goto loop;
1534 }
1535 
1536 /*
1537  * Rubout one character from the rawq of tp
1538  * as cleanly as possible.
1539  */
1540 ttyrub(c, tp)
1541 	register c;
1542 	register struct tty *tp;
1543 {
1544 	register char *cp;
1545 	register int savecol;
1546 	int s;
1547 	char *nextc();
1548 
1549 	if ((tp->t_lflag&ECHO) == 0 || (tp->t_lflag&EXTPROC))
1550 		return;
1551 	tp->t_lflag &= ~FLUSHO;
1552 	if (tp->t_lflag&ECHOE) {
1553 		if (tp->t_rocount == 0) {
1554 			/*
1555 			 * Screwed by ttwrite; retype
1556 			 */
1557 			ttyretype(tp);
1558 			return;
1559 		}
1560 		if (c == ('\t'|TTY_QUOTE) || c == ('\n'|TTY_QUOTE))
1561 			ttyrubo(tp, 2);
1562 		else switch (partab[c&=0377]&077) {
1563 
1564 		case ORDINARY:
1565 			ttyrubo(tp, 1);
1566 			break;
1567 
1568 		case VTAB:
1569 		case BACKSPACE:
1570 		case CONTROL:
1571 		case RETURN:
1572 			if (tp->t_lflag&ECHOCTL)
1573 				ttyrubo(tp, 2);
1574 			break;
1575 
1576 		case TAB: {
1577 			int c;
1578 
1579 			if (tp->t_rocount < tp->t_rawq.c_cc) {
1580 				ttyretype(tp);
1581 				return;
1582 			}
1583 			s = spltty();
1584 			savecol = tp->t_col;
1585 			tp->t_state |= TS_CNTTB;
1586 			tp->t_lflag |= FLUSHO;
1587 			tp->t_col = tp->t_rocol;
1588 			cp = tp->t_rawq.c_cf;
1589 			if (cp)
1590 				c = *cp;	/* XXX FIX NEXTC */
1591 			for (; cp; cp = nextc(&tp->t_rawq, cp, &c))
1592 				ttyecho(c, tp);
1593 			tp->t_lflag &= ~FLUSHO;
1594 			tp->t_state &= ~TS_CNTTB;
1595 			splx(s);
1596 			/*
1597 			 * savecol will now be length of the tab
1598 			 */
1599 			savecol -= tp->t_col;
1600 			tp->t_col += savecol;
1601 			if (savecol > 8)
1602 				savecol = 8;		/* overflow screw */
1603 			while (--savecol >= 0)
1604 				(void) ttyoutput('\b', tp);
1605 			break;
1606 		}
1607 
1608 		default:
1609 			/* XXX */
1610 			printf("ttyrub: would panic c = %d, val = %d\n",
1611 				c, partab[c&=0377]&077);
1612 			/*panic("ttyrub");*/
1613 		}
1614 	} else if (tp->t_lflag&ECHOPRT) {
1615 		if ((tp->t_state&TS_ERASE) == 0) {
1616 			(void) ttyoutput('\\', tp);
1617 			tp->t_state |= TS_ERASE;
1618 		}
1619 		ttyecho(c, tp);
1620 	} else
1621 		ttyecho(tp->t_cc[VERASE], tp);
1622 	tp->t_rocount--;
1623 }
1624 
1625 /*
1626  * Crt back over cnt chars perhaps
1627  * erasing them.
1628  */
1629 ttyrubo(tp, cnt)
1630 	register struct tty *tp;
1631 	int cnt;
1632 {
1633 
1634 	while (--cnt >= 0)
1635 		ttyoutstr("\b \b", tp);
1636 }
1637 
1638 /*
1639  * Reprint the rawq line.
1640  * We assume c_cc has already been checked.
1641  */
1642 ttyretype(tp)
1643 	register struct tty *tp;
1644 {
1645 	register char *cp;
1646 	char *nextc();
1647 	int s, c;
1648 
1649 	if (tp->t_cc[VREPRINT] != _POSIX_VDISABLE)
1650 		ttyecho(tp->t_cc[VREPRINT], tp);
1651 	(void) ttyoutput('\n', tp);
1652 	s = spltty();
1653 	/*** XXX *** FIX *** NEXTC IS BROKEN - DOESN'T CHECK QUOTE
1654 	  BIT OF FIRST CHAR ****/
1655 	for (cp = tp->t_canq.c_cf, c=(cp?*cp:0); cp; cp = nextc(&tp->t_canq, cp, &c)) {
1656 		ttyecho(c, tp);
1657 	}
1658 	for (cp = tp->t_rawq.c_cf, c=(cp?*cp:0); cp; cp = nextc(&tp->t_rawq, cp, &c)) {
1659 		ttyecho(c, tp);
1660 	}
1661 	tp->t_state &= ~TS_ERASE;
1662 	splx(s);
1663 	tp->t_rocount = tp->t_rawq.c_cc;
1664 	tp->t_rocol = 0;
1665 }
1666 
1667 /*
1668  * Echo a typed character to the terminal.
1669  */
1670 ttyecho(c, tp)
1671 	register c;
1672 	register struct tty *tp;
1673 {
1674 	if ((tp->t_state&TS_CNTTB) == 0)
1675 		tp->t_lflag &= ~FLUSHO;
1676 	if (((tp->t_lflag&ECHO) == 0 && ((tp->t_lflag&ECHONL) == 0 ||
1677 					  c == '\n')) || (tp->t_lflag&EXTPROC))
1678 		return;
1679 	if (tp->t_lflag&ECHOCTL) {
1680 		if ((c&TTY_CHARMASK) <= 037 && c != '\t' && c != '\n' ||
1681 		    c == 0177) {
1682 			(void) ttyoutput('^', tp);
1683 			c &= TTY_CHARMASK;
1684 			if (c == 0177)
1685 				c = '?';
1686 			else
1687 				c += 'A' - 1;
1688 		}
1689 	}
1690 	(void) ttyoutput(c, tp);
1691 }
1692 
1693 /*
1694  * send string cp to tp
1695  */
1696 ttyoutstr(cp, tp)
1697 	register char *cp;
1698 	register struct tty *tp;
1699 {
1700 	register char c;
1701 
1702 	while (c = *cp++)
1703 		(void) ttyoutput(c, tp);
1704 }
1705 
1706 ttwakeup(tp)
1707 	struct tty *tp;
1708 {
1709 
1710 	if (tp->t_rsel) {
1711 		selwakeup(tp->t_rsel, tp->t_state&TS_RCOLL);
1712 		tp->t_state &= ~TS_RCOLL;
1713 		tp->t_rsel = 0;
1714 	}
1715 	if (tp->t_state & TS_ASYNC)
1716 		pgsignal(tp->t_pgrp, SIGIO, 1);
1717 	wakeup((caddr_t)&tp->t_rawq);
1718 }
1719 
1720 /*
1721  * set tty hi and low water marks
1722  *
1723  * Try to arrange the dynamics so there's about one second
1724  * from hi to low water.
1725  *
1726  */
1727 ttsetwater(tp)
1728 	struct tty *tp;
1729 {
1730 	register cps = tp->t_ospeed / 10;
1731 	register x;
1732 
1733 #define clamp(x, h, l) ((x)>h ? h : ((x)<l) ? l : (x))
1734 	tp->t_lowat = x = clamp(cps/2, TTMAXLOWAT, TTMINLOWAT);
1735 	x += cps;
1736 	x = clamp(x, TTMAXHIWAT, TTMINHIWAT);
1737 	tp->t_hiwat = roundup(x, CBSIZE);
1738 #undef clamp
1739 }
1740 
1741 ttspeedtab(speed, table)
1742 	struct speedtab table[];
1743 {
1744 	register int i;
1745 
1746 	for (i = 0; table[i].sp_speed != -1; i++)
1747 		if (table[i].sp_speed == speed)
1748 			return(table[i].sp_code);
1749 	return(-1);
1750 }
1751 
1752 int ttyhostname = 0;
1753 /*
1754  * (^T)
1755  * Report on state of foreground process group.
1756  */
1757 ttyinfo(tp)
1758 	struct tty *tp;
1759 {
1760 	register struct proc *p, *pick = NULL;
1761 	register char *cp = hostname;
1762 	int x, s;
1763 	struct timeval utime, stime;
1764 #define	pgtok(a)	(((a)*NBPG)/1024)
1765 
1766 	if (ttycheckoutq(tp,0) == 0)
1767 		return;
1768 	/*
1769 	 * hostname
1770 	 */
1771 	if (ttyhostname) {
1772 		if (*cp == '\0')
1773 			ttyprintf(tp, "amnesia");
1774 		else
1775 			while (*cp && *cp != '.')
1776 				tputchar(*cp++, tp);
1777 		tputchar(' ');
1778 	}
1779 	/*
1780 	 * load average
1781 	 */
1782 	x = (averunnable[0] * 100 + FSCALE/2) >> FSHIFT;
1783 	ttyprintf(tp, "load: %d.", x/100);
1784 	ttyoutint(x%100, 10, 2, tp);
1785 	if (tp->t_session == NULL)
1786 		ttyprintf(tp, " not a controlling terminal\n");
1787 	else if (tp->t_pgrp == NULL)
1788 		ttyprintf(tp, " no foreground process group\n");
1789 	else if ((p = tp->t_pgrp->pg_mem) == NULL)
1790 		ttyprintf(tp, " empty foreground process group\n");
1791 	else {
1792 		/* pick interesting process */
1793 		for (; p != NULL; p = p->p_pgrpnxt) {
1794 			if (proc_compare(pick, p))
1795 				pick = p;
1796 		}
1797 		ttyprintf(tp, "  cmd: %s %d [%s] ",
1798 			pick->p_comm, pick->p_pid,
1799 			pick->p_wmesg ? pick->p_wmesg : "running");
1800 		/*
1801 		 * cpu time
1802 		 */
1803 		if (u.u_procp == pick)
1804 			s = splclock();
1805 		utime = pick->p_utime;
1806 		stime = pick->p_stime;
1807 		if (u.u_procp == pick)
1808 			splx(s);
1809 		/* user time */
1810 		x = (utime.tv_usec + 5000) / 10000; /* scale to 100's */
1811 		ttyoutint(utime.tv_sec, 10, 1, tp);
1812 		tputchar('.', tp);
1813 		ttyoutint(x, 10, 2, tp);
1814 		tputchar('u', tp);
1815 		tputchar(' ', tp);
1816 		/* system time */
1817 		x = (stime.tv_usec + 5000) / 10000; /* scale to 100's */
1818 		ttyoutint(stime.tv_sec, 10, 1, tp);
1819 		tputchar('.', tp);
1820 		ttyoutint(x, 10, 2, tp);
1821 		tputchar('s', tp);
1822 		tputchar(' ', tp);
1823 		/*
1824 		 * pctcpu
1825 		 */
1826 		x = pick->p_pctcpu * 10000 + FSCALE/2 >> FSHIFT;
1827 		ttyoutint(x/100, 10, 1, tp);
1828 #ifdef notdef	/* do we really want this ??? */
1829 		tputchar('.', tp);
1830 		ttyoutint(x%100, 10, 2, tp);
1831 #endif
1832 		ttyprintf(tp, "%% %dk\n", pgtok(pick->p_ssize + pick->p_dsize));
1833 	}
1834 	tp->t_rocount = 0;	/* so pending input will be retyped if BS */
1835 }
1836 
1837 ttyoutint(n, base, min, tp)
1838 	register int n, base, min;
1839 	register struct tty *tp;
1840 {
1841 	char info[16];
1842 	register char *p = info;
1843 
1844 	while (--min >= 0 || n) {
1845 		*p++ = "0123456789abcdef"[n%base];
1846 		n /= base;
1847 	}
1848 	while (p > info)
1849 		ttyoutput(*--p, tp);
1850 }
1851 
1852 /*
1853  * Returns 1 if p2 is "better" than p1
1854  *
1855  * The algorithm for picking the "interesting" process is thus:
1856  *
1857  *	1) (Only foreground processes are eligable - implied)
1858  *	2) Runnable processes are favored over anything
1859  *	   else.  The runner with the highest cpu
1860  *	   utilization is picked (p_cpu).  Ties are
1861  *	   broken by picking the highest pid.
1862  *	3  Next, the sleeper with the shortest sleep
1863  *	   time is favored.  With ties, we pick out
1864  *	   just "short-term" sleepers (SSINTR == 0).
1865  *	   Further ties are broken by picking the highest
1866  *	   pid.
1867  *
1868  */
1869 #define isrun(p)	(((p)->p_stat == SRUN) || ((p)->p_stat == SIDL))
1870 proc_compare(p1, p2)
1871 	register struct proc *p1, *p2;
1872 {
1873 
1874 	if (p1 == NULL)
1875 		return (1);
1876 	/*
1877 	 * see if at least one of them is runnable
1878 	 */
1879 	switch (isrun(p1)<<1 | isrun(p2)) {
1880 	case 0x01:
1881 		return (1);
1882 	case 0x10:
1883 		return (0);
1884 	case 0x11:
1885 		/*
1886 		 * tie - favor one with highest recent cpu utilization
1887 		 */
1888 		if (p2->p_cpu > p1->p_cpu)
1889 			return (1);
1890 		if (p1->p_cpu > p2->p_cpu)
1891 			return (0);
1892 		return (p2->p_pid > p1->p_pid);	/* tie - return highest pid */
1893 	}
1894 	/*
1895 	 * pick the one with the smallest sleep time
1896 	 */
1897 	if (p2->p_slptime > p1->p_slptime)
1898 		return (0);
1899 	if (p1->p_slptime > p2->p_slptime)
1900 		return (1);
1901 	/*
1902 	 * favor one sleeping in a non-interruptible sleep
1903 	 */
1904 	if (p1->p_flag&SSINTR && (p2->p_flag&SSINTR) == 0)
1905 		return (1);
1906 	if (p2->p_flag&SSINTR && (p1->p_flag&SSINTR) == 0)
1907 		return (0);
1908 	return(p2->p_pid > p1->p_pid);		/* tie - return highest pid */
1909 }
1910 #define TOTTY	0x2	/* XXX should be in header */
1911 /*VARARGS2*/
1912 ttyprintf(tp, fmt, x1)
1913 	struct tty *tp;
1914 	char *fmt;
1915 	unsigned x1;
1916 {
1917 	prf(fmt, &x1, TOTTY, (caddr_t)tp);
1918 }
1919 
1920 /*
1921  * Output char to tty; console putchar style.
1922  */
1923 tputchar(c, tp)
1924 	int c;
1925 	struct tty *tp;
1926 {
1927 	register s = spltty();
1928 
1929 	if ((tp->t_state & (TS_CARR_ON | TS_ISOPEN))
1930 	    == (TS_CARR_ON | TS_ISOPEN)) {
1931 		if (c == '\n')
1932 			(void) ttyoutput('\r', tp);
1933 		(void) ttyoutput(c, tp);
1934 		ttstart(tp);
1935 		splx(s);
1936 		return (0);
1937 	}
1938 	splx(s);
1939 	return (-1);
1940 }
1941