xref: /csrg-svn/sys/kern/tty.c (revision 42141)
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	7.25 (Berkeley) 05/16/90
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 &&
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);
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 		tp->t_lflag = t->c_lflag;
457 		bcopy(t->c_cc, tp->t_cc, sizeof(t->c_cc));
458 		splx(s);
459 		break;
460 	}
461 
462 	/*
463 	 * Set controlling terminal.
464 	 * Session ctty vnode pointer set in vnode layer.
465 	 */
466 	case TIOCSCTTY: {
467 		register struct proc *p = u.u_procp;
468 
469 		if (!SESS_LEADER(p) ||
470 		   (p->p_session->s_ttyvp || tp->t_session) &&
471 		   (tp->t_session != p->p_session))
472 			return (EPERM);
473 		tp->t_session = p->p_session;
474 		tp->t_pgrp = p->p_pgrp;
475 		p->p_session->s_ttyp = tp;
476 		p->p_flag |= SCTTY;
477 		break;
478 	}
479 
480 	/*
481 	 * Set terminal process group.
482 	 */
483 	case TIOCSPGRP: {
484 		register struct proc *p = u.u_procp;
485 		register struct pgrp *pgrp = pgfind(*(int *)data);
486 
487 		if (!isctty(p, tp))
488 			return (ENOTTY);
489 		else if (pgrp == NULL || pgrp->pg_session != p->p_session)
490 			return (EPERM);
491 		tp->t_pgrp = pgrp;
492 		break;
493 	}
494 
495 	case TIOCGPGRP:
496 		if (!isctty(u.u_procp, tp))
497 			return (ENOTTY);
498 		*(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
499 		break;
500 
501 	case TIOCSWINSZ:
502 		if (bcmp((caddr_t)&tp->t_winsize, data,
503 		    sizeof (struct winsize))) {
504 			tp->t_winsize = *(struct winsize *)data;
505 			pgsignal(tp->t_pgrp, SIGWINCH);
506 		}
507 		break;
508 
509 	case TIOCGWINSZ:
510 		*(struct winsize *)data = tp->t_winsize;
511 		break;
512 
513 	case TIOCCONS:
514 		if (*(int *)data) {
515 			if (constty && constty != tp &&
516 			    (constty->t_state & (TS_CARR_ON|TS_ISOPEN)) ==
517 			    (TS_CARR_ON|TS_ISOPEN))
518 				return (EBUSY);
519 #ifndef	UCONSOLE
520 			if (error = suser(u.u_cred, &u.u_acflag))
521 				return (error);
522 #endif
523 			constty = tp;
524 		} else if (tp == constty)
525 			constty = NULL;
526 		break;
527 
528 #ifdef COMPAT_43
529 	case TIOCGETP:
530 	case TIOCSETP:
531 	case TIOCSETN:
532 	case TIOCGETC:
533 	case TIOCSETC:
534 	case TIOCSLTC:
535 	case TIOCGLTC:
536 	case TIOCLBIS:
537 	case TIOCLBIC:
538 	case TIOCLSET:
539 	case TIOCLGET:
540 	case OTIOCGETD:
541 	case OTIOCSETD:
542 		return(ttcompat(tp, com, data, flag));
543 #endif
544 
545 	default:
546 		return (-1);
547 	}
548 	return (0);
549 }
550 
551 ttnread(tp)
552 	struct tty *tp;
553 {
554 	int nread = 0;
555 
556 	if (tp->t_lflag & PENDIN)
557 		ttypend(tp);
558 	nread = tp->t_canq.c_cc;
559 	if ((tp->t_lflag & ICANON) == 0)
560 		nread += tp->t_rawq.c_cc;
561 	return (nread);
562 }
563 
564 ttselect(dev, rw)
565 	dev_t dev;
566 	int rw;
567 {
568 	register struct tty *tp = &cdevsw[major(dev)].d_ttys[minor(dev)];
569 	int nread;
570 	int s = spltty();
571 
572 	switch (rw) {
573 
574 	case FREAD:
575 		nread = ttnread(tp);
576 		if (nread > 0 ||
577 		   ((tp->t_cflag&CLOCAL) == 0 && (tp->t_state&TS_CARR_ON) == 0))
578 			goto win;
579 		if (tp->t_rsel && tp->t_rsel->p_wchan == (caddr_t)&selwait)
580 			tp->t_state |= TS_RCOLL;
581 		else
582 			tp->t_rsel = u.u_procp;
583 		break;
584 
585 	case FWRITE:
586 		if (tp->t_outq.c_cc <= tp->t_lowat)
587 			goto win;
588 		if (tp->t_wsel && tp->t_wsel->p_wchan == (caddr_t)&selwait)
589 			tp->t_state |= TS_WCOLL;
590 		else
591 			tp->t_wsel = u.u_procp;
592 		break;
593 	}
594 	splx(s);
595 	return (0);
596 win:
597 	splx(s);
598 	return (1);
599 }
600 
601 /*
602  * Initial open of tty, or (re)entry to line discipline.
603  */
604 ttyopen(dev, tp)
605 	dev_t dev;
606 	register struct tty *tp;
607 {
608 
609 	tp->t_dev = dev;
610 
611 	tp->t_state &= ~TS_WOPEN;
612 	if ((tp->t_state & TS_ISOPEN) == 0) {
613 		tp->t_state |= TS_ISOPEN;
614 		bzero((caddr_t)&tp->t_winsize, sizeof(tp->t_winsize));
615 	}
616 	return (0);
617 }
618 
619 /*
620  * "close" a line discipline
621  */
622 ttylclose(tp)
623 	register struct tty *tp;
624 {
625 
626 	ttywflush(tp);
627 }
628 
629 /*
630  * clean tp on last close
631  */
632 ttyclose(tp)
633 	register struct tty *tp;
634 {
635 	if (constty == tp)
636 		constty = NULL;
637 	ttyflush(tp, FREAD|FWRITE);
638 	tp->t_session = NULL;
639 	tp->t_pgrp = NULL;
640 	tp->t_state = 0;
641 	return (0);
642 }
643 
644 /*
645  * Handle modem control transition on a tty.
646  * Flag indicates new state of carrier.
647  * Returns 0 if the line should be turned off, otherwise 1.
648  */
649 ttymodem(tp, flag)
650 	register struct tty *tp;
651 {
652 
653 	if ((tp->t_state&TS_WOPEN) == 0 && (tp->t_lflag & MDMBUF)) {
654 		/*
655 		 * MDMBUF: do flow control according to carrier flag
656 		 */
657 		if (flag) {
658 			tp->t_state &= ~TS_TTSTOP;
659 			ttstart(tp);
660 		} else if ((tp->t_state&TS_TTSTOP) == 0) {
661 			tp->t_state |= TS_TTSTOP;
662 			(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
663 		}
664 	} else if (flag == 0) {
665 		/*
666 		 * Lost carrier.
667 		 */
668 		tp->t_state &= ~TS_CARR_ON;
669 		if (tp->t_state & TS_ISOPEN) {
670 			if ((tp->t_lflag & NOHANG) == 0) {
671 				pgsignal(tp->t_pgrp, SIGHUP);
672 				pgsignal(tp->t_pgrp, SIGCONT);
673 				ttyflush(tp, FREAD|FWRITE);
674 				return (0);
675 			}
676 		}
677 	} else {
678 		/*
679 		 * Carrier now on.
680 		 */
681 		tp->t_state |= TS_CARR_ON;
682 		ttwakeup(tp);
683 	}
684 	return (1);
685 }
686 
687 /*
688  * Default modem control routine (for other line disciplines).
689  * Return argument flag, to turn off device on carrier drop.
690  */
691 nullmodem(tp, flag)
692 	register struct tty *tp;
693 	int flag;
694 {
695 
696 	if (flag)
697 		tp->t_state |= TS_CARR_ON;
698 	else {
699 		tp->t_state &= ~TS_CARR_ON;
700 		if ((tp->t_lflag & NOHANG) == 0)
701 			pgsignal(tp->t_pgrp, SIGHUP);
702 	}
703 	return (flag);
704 }
705 
706 /*
707  * reinput pending characters after state switch
708  * call at spltty().
709  */
710 ttypend(tp)
711 	register struct tty *tp;
712 {
713 	struct clist tq;
714 	register c;
715 
716 	tp->t_lflag &= ~PENDIN;
717 	tp->t_state |= TS_TYPEN;
718 	tq = tp->t_rawq;
719 	tp->t_rawq.c_cc = 0;
720 	tp->t_rawq.c_cf = tp->t_rawq.c_cl = 0;
721 	while ((c = getc(&tq)) >= 0)
722 		ttyinput(c, tp);
723 	tp->t_state &= ~TS_TYPEN;
724 }
725 
726 /*
727  *
728  * Place a character on raw TTY input queue,
729  * putting in delimiters and waking up top
730  * half as needed.  Also echo if required.
731  * The arguments are the character and the
732  * appropriate tty structure.
733  */
734 ttyinput(c, tp)
735 	register c;
736 	register struct tty *tp;
737 {
738 	register int iflag = tp->t_iflag;
739 	register int lflag = tp->t_lflag;
740 	register u_char *cc = tp->t_cc;
741 	int i, err;
742 
743 	/*
744 	 * If input is pending take it first.
745 	 */
746 	if (lflag&PENDIN)
747 		ttypend(tp);
748 	/*
749 	 * Gather stats.
750 	 */
751 	tk_nin++;
752 	if (lflag&ICANON) {
753 		tk_cancc++;
754 		tp->t_cancc++;
755 	} else {
756 		tk_rawcc++;
757 		tp->t_rawcc++;
758 	}
759 	/*
760 	 * Handle exceptional conditions (break, parity, framing).
761 	 */
762 	if (err = (c&TTY_ERRORMASK)) {
763 		c &= ~TTY_ERRORMASK;
764 		if (err&TTY_FE && !c) {		/* break */
765 			if (iflag&IGNBRK)
766 				goto endcase;
767 			else if (iflag&BRKINT && lflag&ISIG &&
768 				(cc[VINTR] != _POSIX_VDISABLE))
769 				c = cc[VINTR];
770 			else {
771 				c = 0;
772 				if (iflag&PARMRK)
773 					goto parmrk;
774 			}
775 		} else if ((err&TTY_PE && iflag&INPCK) || err&TTY_FE) {
776 			if (iflag&IGNPAR)
777 				goto endcase;
778 			else if (iflag&PARMRK) {
779 parmrk:
780 				putc(0377|TTY_QUOTE, &tp->t_rawq);
781 				putc(0|TTY_QUOTE, &tp->t_rawq);
782 				putc(c|TTY_QUOTE, &tp->t_rawq);
783 				goto endcase;
784 			} else
785 				c = 0;
786 		}
787 	}
788 	/*
789 	 * In tandem mode, check high water mark.
790 	 */
791 	if (iflag&IXOFF)
792 		ttyblock(tp);
793 	if ((tp->t_state&TS_TYPEN) == 0 && (iflag&ISTRIP))
794 		c &= 0177;
795 	/*
796 	 * Check for literal nexting very first
797 	 */
798 	if (tp->t_state&TS_LNCH) {
799 		c |= TTY_QUOTE;
800 		tp->t_state &= ~TS_LNCH;
801 	}
802 	/*
803 	 * Scan for special characters.  This code
804 	 * is really just a big case statement with
805 	 * non-constant cases.  The bottom of the
806 	 * case statement is labeled ``endcase'', so goto
807 	 * it after a case match, or similar.
808 	 */
809 	/*
810 	 * Control chars which aren't controlled
811 	 * by ICANON, ISIG, or IXON.
812 	 */
813 	if (lflag&IEXTEN) {
814 		if (CCEQ(cc[VLNEXT], c)) {
815 			if (lflag&ECHO) {
816 				if (lflag&ECHOE)
817 					ttyoutstr("^\b", tp);
818 				else
819 					ttyecho(c, tp);
820 			}
821 			tp->t_state |= TS_LNCH;
822 			goto endcase;
823 		}
824 		if (CCEQ(cc[VFLUSHO], c)) {
825 			if (lflag&FLUSHO)
826 				tp->t_lflag &= ~FLUSHO;
827 			else {
828 				ttyflush(tp, FWRITE);
829 				ttyecho(c, tp);
830 				if (tp->t_rawq.c_cc + tp->t_canq.c_cc)
831 					ttyretype(tp);
832 				tp->t_lflag |= FLUSHO;
833 			}
834 			goto startoutput;
835 		}
836 	}
837 	/*
838 	 * Signals.
839 	 */
840 	if (lflag&ISIG) {
841 		if (CCEQ(cc[VINTR], c) || CCEQ(cc[VQUIT], c)) {
842 			if ((lflag&NOFLSH) == 0)
843 				ttyflush(tp, FREAD|FWRITE);
844 			ttyecho(c, tp);
845 			pgsignal(tp->t_pgrp,
846 			    CCEQ(cc[VINTR], c) ? SIGINT : SIGQUIT);
847 			goto endcase;
848 		}
849 		if (CCEQ(cc[VSUSP], c)) {
850 			if ((lflag&NOFLSH) == 0)
851 				ttyflush(tp, FREAD);
852 			ttyecho(c, tp);
853 			pgsignal(tp->t_pgrp, SIGTSTP);
854 			goto endcase;
855 		}
856 	}
857 	/*
858 	 * Handle start/stop characters.
859 	 */
860 	if (iflag&IXON) {
861 		if (CCEQ(cc[VSTOP], c)) {
862 			if ((tp->t_state&TS_TTSTOP) == 0) {
863 				tp->t_state |= TS_TTSTOP;
864 				(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
865 				return;
866 			}
867 			if (!CCEQ(cc[VSTART], c))
868 				return;
869 			/*
870 			 * if VSTART == VSTOP then toggle
871 			 */
872 			goto endcase;
873 		}
874 		if (CCEQ(cc[VSTART], c))
875 			goto restartoutput;
876 	}
877 	/*
878 	 * IGNCR, ICRNL, & INLCR
879 	 */
880 	if (c == '\r') {
881 		if (iflag&IGNCR)
882 			goto endcase;
883 		else if (iflag&ICRNL)
884 			c = '\n';
885 	}
886 	else if (c == '\n' && iflag&INLCR)
887 		c = '\r';
888 	/*
889 	 * Non canonical mode; don't process line editing
890 	 * characters; check high water mark for wakeup.
891 	 *
892 	 */
893 	if ((lflag&ICANON) == 0) {
894 		if (tp->t_rawq.c_cc > TTYHOG) {
895 			if (iflag&IMAXBEL) {
896 				if (tp->t_outq.c_cc < tp->t_hiwat)
897 					(void) ttyoutput(CTRL('g'), tp);
898 			} else
899 				ttyflush(tp, FREAD | FWRITE);
900 		} else {
901 			if (putc(c, &tp->t_rawq) >= 0) {
902 				ttwakeup(tp);
903 				ttyecho(c, tp);
904 			}
905 		}
906 		goto endcase;
907 	}
908 	/*
909 	 * From here on down canonical mode character
910 	 * processing takes place.
911 	 */
912 	/*
913 	 * erase (^H / ^?)
914 	 */
915 	if (CCEQ(cc[VERASE], c)) {
916 		if (tp->t_rawq.c_cc)
917 			ttyrub(unputc(&tp->t_rawq), tp);
918 		goto endcase;
919 	}
920 	/*
921 	 * kill (^U)
922 	 */
923 	if (CCEQ(cc[VKILL], c)) {
924 		if (lflag&ECHOKE && tp->t_rawq.c_cc == tp->t_rocount &&
925 		    (lflag&ECHOPRT) == 0) {
926 			while (tp->t_rawq.c_cc)
927 				ttyrub(unputc(&tp->t_rawq), tp);
928 		} else {
929 			ttyecho(c, tp);
930 			if (lflag&ECHOK || lflag&ECHOKE)
931 				ttyecho('\n', tp);
932 			while (getc(&tp->t_rawq) > 0)
933 				;
934 			tp->t_rocount = 0;
935 		}
936 		tp->t_state &= ~TS_LOCAL;
937 		goto endcase;
938 	}
939 	/*
940 	 * word erase (^W)
941 	 */
942 	if (CCEQ(cc[VWERASE], c)) {
943 		int ctype;
944 
945 #define CTYPE(c) ((lflag&ALTWERASE) ? (partab[(c)&TTY_CHARMASK]&0100) : 0)
946 		/*
947 		 * erase whitespace
948 		 */
949 		while ((c = unputc(&tp->t_rawq)) == ' ' || c == '\t')
950 			ttyrub(c, tp);
951 		if (c == -1)
952 			goto endcase;
953 		/*
954 		 * special case last char of token
955 		 */
956 		ttyrub(c, tp);
957 		c = unputc(&tp->t_rawq);
958 		if (c == -1 || c == ' ' || c == '\t') {
959 			if (c != -1)
960 				(void) putc(c, &tp->t_rawq);
961 			goto endcase;
962 		}
963 		/*
964 		 * erase rest of token
965 		 */
966 		ctype = CTYPE(c);
967 		do {
968 			ttyrub(c, tp);
969 			c = unputc(&tp->t_rawq);
970 			if (c == -1)
971 				goto endcase;
972 		} while (c != ' ' && c != '\t' && CTYPE(c) == ctype);
973 		(void) putc(c, &tp->t_rawq);
974 		goto endcase;
975 #undef CTYPE
976 	}
977 	/*
978 	 * reprint line (^R)
979 	 */
980 	if (CCEQ(cc[VREPRINT], c)) {
981 		ttyretype(tp);
982 		goto endcase;
983 	}
984 	if (CCEQ(cc[VINFO], c)) {
985 		pgsignal(tp->t_pgrp, SIGINFO);
986 		if ((lflag&NOKERNINFO) == 0)
987 			ttyinfo(tp);
988 		goto endcase;
989 	}
990 	/*
991 	 * Check for input buffer overflow
992 	 */
993 	if (tp->t_rawq.c_cc+tp->t_canq.c_cc >= TTYHOG) {
994 		if (iflag&IMAXBEL) {
995 			if (tp->t_outq.c_cc < tp->t_hiwat)
996 				(void) ttyoutput(CTRL('g'), tp);
997 		} else
998 			ttyflush(tp, FREAD | FWRITE);
999 		goto endcase;
1000 	}
1001 	/*
1002 	 * Put data char in q for user and
1003 	 * wakeup on seeing a line delimiter.
1004 	 */
1005 	if (putc(c, &tp->t_rawq) >= 0) {
1006 		if (ttbreakc(c)) {
1007 			tp->t_rocount = 0;
1008 			catq(&tp->t_rawq, &tp->t_canq);
1009 			ttwakeup(tp);
1010 		} else if (tp->t_rocount++ == 0)
1011 			tp->t_rocol = tp->t_col;
1012 		if (tp->t_state&TS_ERASE) {
1013 			/*
1014 			 * end of prterase \.../
1015 			 */
1016 			tp->t_state &= ~TS_ERASE;
1017 			(void) ttyoutput('/', tp);
1018 		}
1019 		i = tp->t_col;
1020 		ttyecho(c, tp);
1021 		if (CCEQ(cc[VEOF], c) && lflag&ECHO) {
1022 			/*
1023 			 * Place the cursor over the '^' of the ^D.
1024 			 */
1025 			i = MIN(2, tp->t_col - i);
1026 			while (i > 0) {
1027 				(void) ttyoutput('\b', tp);
1028 				i--;
1029 			}
1030 		}
1031 	}
1032 endcase:
1033 	/*
1034 	 * IXANY means allow any character to restart output.
1035 	 */
1036 	if ((tp->t_state&TS_TTSTOP) && (iflag&IXANY) == 0 &&
1037 	    cc[VSTART] != cc[VSTOP])
1038 		return;
1039 restartoutput:
1040 	tp->t_state &= ~TS_TTSTOP;
1041 	tp->t_lflag &= ~FLUSHO;
1042 startoutput:
1043 	ttstart(tp);
1044 }
1045 
1046 /*
1047  * Put character on TTY output queue, adding delays,
1048  * expanding tabs, and handling the CR/NL bit.
1049  * This is called both from the top half for output,
1050  * and from interrupt level for echoing.
1051  * The arguments are the character and the tty structure.
1052  * Returns < 0 if putc succeeds, otherwise returns char to resend
1053  * Must be recursive.
1054  */
1055 ttyoutput(c, tp)
1056 	register c;
1057 	register struct tty *tp;
1058 {
1059 	register char *colp;
1060 	register ctype;
1061 	register long oflag = tp->t_oflag;
1062 
1063 	if ((oflag&OPOST) == 0) {
1064 		if (tp->t_lflag&FLUSHO)
1065 			return (-1);
1066 		if (putc(c, &tp->t_outq))
1067 			return (c);
1068 		tk_nout++;
1069 		tp->t_outcc++;
1070 		return (-1);
1071 	}
1072 	c &= TTY_CHARMASK;
1073 	/*
1074 	 * Turn tabs to spaces as required
1075 	 */
1076 	if (c == '\t' && oflag&OXTABS ) {
1077 		register int s;
1078 
1079 		c = 8 - (tp->t_col&7);
1080 		if ((tp->t_lflag&FLUSHO) == 0) {
1081 			s = spltty();		/* don't interrupt tabs */
1082 			c -= b_to_q("        ", c, &tp->t_outq);
1083 			tk_nout += c;
1084 			tp->t_outcc += c;
1085 			splx(s);
1086 		}
1087 		tp->t_col += c;
1088 		return (c ? -1 : '\t');
1089 	}
1090 	if (c == CEOT && oflag&ONOEOT)
1091 		return(-1);
1092 	tk_nout++;
1093 	tp->t_outcc++;
1094 	/*
1095 	 * turn <nl> to <cr><lf> if desired.
1096 	 */
1097 	if (c == '\n' && (tp->t_oflag&ONLCR) && ttyoutput('\r', tp) >= 0)
1098 		return (c);
1099 	if ((tp->t_lflag&FLUSHO) == 0 && putc(c, &tp->t_outq))
1100 		return (c);
1101 	/*
1102 	 * Calculate delays.
1103 	 * The numbers here represent clock ticks
1104 	 * and are not necessarily optimal for all terminals.
1105 	 *
1106 	 * SHOULD JUST ALLOW USER TO SPECIFY DELAYS
1107 	 *
1108 	 * (actually, should THROW AWAY terminals which need delays)
1109 	 */
1110 	colp = &tp->t_col;
1111 	ctype = partab[c];
1112 	c = 0;
1113 	switch (ctype&077) {
1114 
1115 	case ORDINARY:
1116 		(*colp)++;
1117 
1118 	case CONTROL:
1119 		break;
1120 
1121 	case BACKSPACE:
1122 		if (*colp)
1123 			(*colp)--;
1124 		break;
1125 
1126 	/*
1127 	 * This macro is close enough to the correct thing;
1128 	 * it should be replaced by real user settable delays
1129 	 * in any event...
1130 	 */
1131 #define	mstohz(ms)	(((ms) * hz) >> 10)
1132 	case NEWLINE:
1133 		ctype = (tp->t_flags >> 8) & 03;
1134 		if (ctype == 1) { /* tty 37 */
1135 			if (*colp > 0) {
1136 				c = (((unsigned)*colp) >> 4) + 3;
1137 				if ((unsigned)c > 6)
1138 					c = 6;
1139 			}
1140 		} else if (ctype == 2) /* vt05 */
1141 			c = mstohz(100);
1142 		*colp = 0;
1143 		break;
1144 
1145 	case TAB:
1146 		ctype = (tp->t_flags >> 10) & 03;
1147 		if (ctype == 1) { /* tty 37 */
1148 			c = 1 - (*colp | ~07);
1149 			if (c < 5)
1150 				c = 0;
1151 		}
1152 		*colp |= 07;
1153 		(*colp)++;
1154 		break;
1155 
1156 	case VTAB:
1157 		if (tp->t_flags&VTDELAY) /* tty 37 */
1158 			c = 0177;
1159 		break;
1160 
1161 	case RETURN:
1162 		ctype = (tp->t_flags >> 12) & 03;
1163 		if (ctype == 1) /* tn 300 */
1164 			c = mstohz(83);
1165 		else if (ctype == 2) /* ti 700 */
1166 			c = mstohz(166);
1167 		else if (ctype == 3) { /* concept 100 */
1168 			int i;
1169 
1170 			if ((i = *colp) >= 0)
1171 				for (; i < 9; i++)
1172 					(void) putc(0177, &tp->t_outq);
1173 		}
1174 		*colp = 0;
1175 	}
1176 	if (c && (tp->t_lflag&FLUSHO) == 0)
1177 		(void) putc(c|TTY_QUOTE, &tp->t_outq);
1178 	return (-1);
1179 }
1180 #undef mstohz
1181 
1182 /*
1183  * Called from device's read routine after it has
1184  * calculated the tty-structure given as argument.
1185  */
1186 ttread(tp, uio, flag)
1187 	register struct tty *tp;
1188 	struct uio *uio;
1189 {
1190 	register struct clist *qp;
1191 	register int c;
1192 	register long lflag;
1193 	register u_char *cc = tp->t_cc;
1194 	int s, first, error = 0;
1195 
1196 loop:
1197 	lflag = tp->t_lflag;
1198 	s = spltty();
1199 	/*
1200 	 * take pending input first
1201 	 */
1202 	if (lflag&PENDIN)
1203 		ttypend(tp);
1204 	splx(s);
1205 
1206 	/*
1207 	 * Hang process if it's in the background.
1208 	 */
1209 	if (isbackground(u.u_procp, tp)) {
1210 		if ((u.u_procp->p_sigignore & sigmask(SIGTTIN)) ||
1211 		   (u.u_procp->p_sigmask & sigmask(SIGTTIN)) ||
1212 		    u.u_procp->p_flag&SVFORK || u.u_procp->p_pgrp->pg_jobc == 0)
1213 			return (EIO);
1214 		pgsignal(u.u_procp->p_pgrp, SIGTTIN);
1215 		if (error = tsleep((caddr_t)&lbolt, TTIPRI | PCATCH, ttybg, 0))
1216 			return (error);
1217 		goto loop;
1218 	}
1219 
1220 	/*
1221 	 * If canonical, use the canonical queue,
1222 	 * else use the raw queue.
1223 	 *
1224 	 * XXX - should get rid of canonical queue.
1225 	 * (actually, should get rid of clists...)
1226 	 */
1227 	qp = lflag&ICANON ? &tp->t_canq : &tp->t_rawq;
1228 
1229 	/*
1230 	 * If there is no input, sleep on rawq
1231 	 * awaiting hardware receipt and notification.
1232 	 * If we have data, we don't need to check for carrier.
1233 	 */
1234 	s = spltty();
1235 	if (qp->c_cc <= 0) {
1236 		int carrier;
1237 
1238 		carrier = (tp->t_state&TS_CARR_ON) || (tp->t_cflag&CLOCAL);
1239 		if (!carrier && tp->t_state&TS_ISOPEN) {
1240 			splx(s);
1241 			return (0);	/* EOF */
1242 		}
1243 		if (flag & IO_NDELAY) {
1244 			splx(s);
1245 			return (EWOULDBLOCK);
1246 		}
1247 		error = tsleep((caddr_t)&tp->t_rawq, TTIPRI | PCATCH,
1248 		    carrier ? ttyin : ttopen, 0);
1249 		splx(s);
1250 		if (error)
1251 			return (error);
1252 		goto loop;
1253 	}
1254 	splx(s);
1255 
1256 	/*
1257 	 * Input present, check for input mapping and processing.
1258 	 */
1259 	first = 1;
1260 	while ((c = getc(qp)) >= 0) {
1261 		/*
1262 		 * delayed suspend (^Y)
1263 		 */
1264 		if (CCEQ(cc[VDSUSP], c) && lflag&ISIG) {
1265 			pgsignal(tp->t_pgrp, SIGTSTP);
1266 			if (first) {
1267 				if (error = tsleep((caddr_t)&lbolt,
1268 				    TTIPRI | PCATCH, ttybg, 0))
1269 					break;
1270 				goto loop;
1271 			}
1272 			break;
1273 		}
1274 		/*
1275 		 * Interpret EOF only in canonical mode.
1276 		 */
1277 		if (CCEQ(cc[VEOF], c) && lflag&ICANON)
1278 			break;
1279 		/*
1280 		 * Give user character.
1281 		 */
1282  		error = ureadc(c, uio);
1283 		if (error)
1284 			break;
1285  		if (uio->uio_resid == 0)
1286 			break;
1287 		/*
1288 		 * In canonical mode check for a "break character"
1289 		 * marking the end of a "line of input".
1290 		 */
1291 		if (lflag&ICANON && ttbreakc(c))
1292 			break;
1293 		first = 0;
1294 	}
1295 	/*
1296 	 * Look to unblock output now that (presumably)
1297 	 * the input queue has gone down.
1298 	 */
1299 	if (tp->t_state&TS_TBLOCK && tp->t_rawq.c_cc < TTYHOG/5) {
1300 		if (cc[VSTART] != _POSIX_VDISABLE
1301 		   && putc(cc[VSTART], &tp->t_outq) == 0) {
1302 			tp->t_state &= ~TS_TBLOCK;
1303 			ttstart(tp);
1304 		}
1305 	}
1306 	return (error);
1307 }
1308 
1309 /*
1310  * Check the output queue on tp for space for a kernel message
1311  * (from uprintf/tprintf).  Allow some space over the normal
1312  * hiwater mark so we don't lose messages due to normal flow
1313  * control, but don't let the tty run amok.
1314  * Sleeps here are not interruptible, but we return prematurely
1315  * if new signals come in.
1316  */
1317 ttycheckoutq(tp, wait)
1318 	register struct tty *tp;
1319 	int wait;
1320 {
1321 	int hiwat, s, oldsig;
1322 
1323 	hiwat = tp->t_hiwat;
1324 	s = spltty();
1325 	oldsig = u.u_procp->p_sig;
1326 	if (tp->t_outq.c_cc > hiwat + 200)
1327 		while (tp->t_outq.c_cc > hiwat) {
1328 			ttstart(tp);
1329 			if (wait == 0 || u.u_procp->p_sig != oldsig) {
1330 				splx(s);
1331 				return (0);
1332 			}
1333 			timeout(wakeup, (caddr_t)&tp->t_outq, hz);
1334 			tp->t_state |= TS_ASLEEP;
1335 			sleep((caddr_t)&tp->t_outq, PZERO - 1);
1336 		}
1337 	splx(s);
1338 	return (1);
1339 }
1340 
1341 /*
1342  * Called from the device's write routine after it has
1343  * calculated the tty-structure given as argument.
1344  */
1345 ttwrite(tp, uio, flag)
1346 	register struct tty *tp;
1347 	register struct uio *uio;
1348 {
1349 	register char *cp;
1350 	register int cc = 0, ce;
1351 	int i, hiwat, cnt, error, s;
1352 	char obuf[OBUFSIZ];
1353 
1354 	hiwat = tp->t_hiwat;
1355 	cnt = uio->uio_resid;
1356 	error = 0;
1357 loop:
1358 	s = spltty();
1359 	if ((tp->t_state&TS_CARR_ON) == 0 && (tp->t_cflag&CLOCAL) == 0) {
1360 		if (tp->t_state&TS_ISOPEN) {
1361 			splx(s);
1362 			return (EIO);
1363 		} else if (flag & IO_NDELAY) {
1364 			splx(s);
1365 			error = EWOULDBLOCK;
1366 			goto out;
1367 		} else {
1368 			/*
1369 			 * sleep awaiting carrier
1370 			 */
1371 			error = tsleep((caddr_t)&tp->t_rawq, TTIPRI | PCATCH,
1372 			    ttopen, 0);
1373 			splx(s);
1374 			if (error)
1375 				goto out;
1376 			goto loop;
1377 		}
1378 	}
1379 	splx(s);
1380 	/*
1381 	 * Hang the process if it's in the background.
1382 	 */
1383 	if (isbackground(u.u_procp, tp) &&
1384 	    (tp->t_lflag&TOSTOP) && (u.u_procp->p_flag&SVFORK)==0 &&
1385 	    (u.u_procp->p_sigignore & sigmask(SIGTTOU)) == 0 &&
1386 	    (u.u_procp->p_sigmask & sigmask(SIGTTOU)) == 0 &&
1387 	     u.u_procp->p_pgrp->pg_jobc) {
1388 		pgsignal(u.u_procp->p_pgrp, SIGTTOU);
1389 		if (error = tsleep((caddr_t)&lbolt, TTIPRI | PCATCH, ttybg, 0))
1390 			goto out;
1391 		goto loop;
1392 	}
1393 	/*
1394 	 * Process the user's data in at most OBUFSIZ
1395 	 * chunks.  Perform any output translation.
1396 	 * Keep track of high water mark, sleep on overflow
1397 	 * awaiting device aid in acquiring new space.
1398 	 */
1399 	while (uio->uio_resid > 0 || cc > 0) {
1400 		if (tp->t_lflag&FLUSHO) {
1401 			uio->uio_resid = 0;
1402 			return (0);
1403 		}
1404 		if (tp->t_outq.c_cc > hiwat)
1405 			goto ovhiwat;
1406 		/*
1407 		 * Grab a hunk of data from the user,
1408 		 * unless we have some leftover from last time.
1409 		 */
1410 		if (cc == 0) {
1411 			cc = min(uio->uio_resid, OBUFSIZ);
1412 			cp = obuf;
1413 			error = uiomove(cp, cc, uio);
1414 			if (error) {
1415 				cc = 0;
1416 				break;
1417 			}
1418 		}
1419 		/*
1420 		 * If nothing fancy need be done, grab those characters we
1421 		 * can handle without any of ttyoutput's processing and
1422 		 * just transfer them to the output q.  For those chars
1423 		 * which require special processing (as indicated by the
1424 		 * bits in partab), call ttyoutput.  After processing
1425 		 * a hunk of data, look for FLUSHO so ^O's will take effect
1426 		 * immediately.
1427 		 */
1428 		while (cc > 0) {
1429 			if ((tp->t_oflag&OPOST) == 0)
1430 				ce = cc;
1431 			else {
1432 				ce = cc - scanc((unsigned)cc, (u_char *)cp,
1433 				   (u_char *)partab, 077);
1434 				/*
1435 				 * If ce is zero, then we're processing
1436 				 * a special character through ttyoutput.
1437 				 */
1438 				if (ce == 0) {
1439 					tp->t_rocount = 0;
1440 					if (ttyoutput(*cp, tp) >= 0) {
1441 					    /* no c-lists, wait a bit */
1442 					    ttstart(tp);
1443 					    if (error = tsleep((caddr_t)&lbolt,
1444 						TTOPRI | PCATCH, ttybuf, 0))
1445 						    break;
1446 					    goto loop;
1447 					}
1448 					cp++, cc--;
1449 					if ((tp->t_lflag&FLUSHO) ||
1450 					    tp->t_outq.c_cc > hiwat)
1451 						goto ovhiwat;
1452 					continue;
1453 				}
1454 			}
1455 			/*
1456 			 * A bunch of normal characters have been found,
1457 			 * transfer them en masse to the output queue and
1458 			 * continue processing at the top of the loop.
1459 			 * If there are any further characters in this
1460 			 * <= OBUFSIZ chunk, the first should be a character
1461 			 * requiring special handling by ttyoutput.
1462 			 */
1463 			tp->t_rocount = 0;
1464 			i = b_to_q(cp, ce, &tp->t_outq);
1465 			ce -= i;
1466 			tp->t_col += ce;
1467 			cp += ce, cc -= ce, tk_nout += ce;
1468 			tp->t_outcc += ce;
1469 			if (i > 0) {
1470 				/* out of c-lists, wait a bit */
1471 				ttstart(tp);
1472 				if (error = tsleep((caddr_t)&lbolt,
1473 				    TTOPRI | PCATCH, ttybuf, 0))
1474 					break;
1475 				goto loop;
1476 			}
1477 			if (tp->t_lflag&FLUSHO || tp->t_outq.c_cc > hiwat)
1478 				break;
1479 		}
1480 		ttstart(tp);
1481 	}
1482 out:
1483 	/*
1484 	 * If cc is nonzero, we leave the uio structure inconsistent,
1485 	 * as the offset and iov pointers have moved forward,
1486 	 * but it doesn't matter (the call will either return short
1487 	 * or restart with a new uio).
1488 	 */
1489 	uio->uio_resid += cc;
1490 	return (error);
1491 
1492 ovhiwat:
1493 	ttstart(tp);
1494 	s = spltty();
1495 	/*
1496 	 * This can only occur if FLUSHO is set in t_lflag,
1497 	 * or if ttstart/oproc is synchronous (or very fast).
1498 	 */
1499 	if (tp->t_outq.c_cc <= hiwat) {
1500 		splx(s);
1501 		goto loop;
1502 	}
1503 	if (flag & IO_NDELAY) {
1504 		splx(s);
1505 		uio->uio_resid += cc;
1506 		if (uio->uio_resid == cnt)
1507 			return (EWOULDBLOCK);
1508 		return (0);
1509 	}
1510 	tp->t_state |= TS_ASLEEP;
1511 	error = tsleep((caddr_t)&tp->t_outq, TTOPRI | PCATCH, ttyout, 0);
1512 	splx(s);
1513 	if (error)
1514 		goto out;
1515 	goto loop;
1516 }
1517 
1518 /*
1519  * Rubout one character from the rawq of tp
1520  * as cleanly as possible.
1521  */
1522 ttyrub(c, tp)
1523 	register c;
1524 	register struct tty *tp;
1525 {
1526 	register char *cp;
1527 	register int savecol;
1528 	int s;
1529 	char *nextc();
1530 
1531 	if ((tp->t_lflag&ECHO) == 0)
1532 		return;
1533 	tp->t_lflag &= ~FLUSHO;
1534 	if (tp->t_lflag&ECHOE) {
1535 		if (tp->t_rocount == 0) {
1536 			/*
1537 			 * Screwed by ttwrite; retype
1538 			 */
1539 			ttyretype(tp);
1540 			return;
1541 		}
1542 		if (c == ('\t'|TTY_QUOTE) || c == ('\n'|TTY_QUOTE))
1543 			ttyrubo(tp, 2);
1544 		else switch (partab[c&=0377]&077) {
1545 
1546 		case ORDINARY:
1547 			ttyrubo(tp, 1);
1548 			break;
1549 
1550 		case VTAB:
1551 		case BACKSPACE:
1552 		case CONTROL:
1553 		case RETURN:
1554 			if (tp->t_lflag&ECHOCTL)
1555 				ttyrubo(tp, 2);
1556 			break;
1557 
1558 		case TAB: {
1559 			int c;
1560 
1561 			if (tp->t_rocount < tp->t_rawq.c_cc) {
1562 				ttyretype(tp);
1563 				return;
1564 			}
1565 			s = spltty();
1566 			savecol = tp->t_col;
1567 			tp->t_state |= TS_CNTTB;
1568 			tp->t_lflag |= FLUSHO;
1569 			tp->t_col = tp->t_rocol;
1570 			cp = tp->t_rawq.c_cf;
1571 			if (cp)
1572 				c = *cp;	/* XXX FIX NEXTC */
1573 			for (; cp; cp = nextc(&tp->t_rawq, cp, &c))
1574 				ttyecho(c, tp);
1575 			tp->t_lflag &= ~FLUSHO;
1576 			tp->t_state &= ~TS_CNTTB;
1577 			splx(s);
1578 			/*
1579 			 * savecol will now be length of the tab
1580 			 */
1581 			savecol -= tp->t_col;
1582 			tp->t_col += savecol;
1583 			if (savecol > 8)
1584 				savecol = 8;		/* overflow screw */
1585 			while (--savecol >= 0)
1586 				(void) ttyoutput('\b', tp);
1587 			break;
1588 		}
1589 
1590 		default:
1591 			/* XXX */
1592 			printf("ttyrub: would panic c = %d, val = %d\n",
1593 				c, partab[c&=0377]&077);
1594 			/*panic("ttyrub");*/
1595 		}
1596 	} else if (tp->t_lflag&ECHOPRT) {
1597 		if ((tp->t_state&TS_ERASE) == 0) {
1598 			(void) ttyoutput('\\', tp);
1599 			tp->t_state |= TS_ERASE;
1600 		}
1601 		ttyecho(c, tp);
1602 	} else
1603 		ttyecho(tp->t_cc[VERASE], tp);
1604 	tp->t_rocount--;
1605 }
1606 
1607 /*
1608  * Crt back over cnt chars perhaps
1609  * erasing them.
1610  */
1611 ttyrubo(tp, cnt)
1612 	register struct tty *tp;
1613 	int cnt;
1614 {
1615 
1616 	while (--cnt >= 0)
1617 		ttyoutstr("\b \b", tp);
1618 }
1619 
1620 /*
1621  * Reprint the rawq line.
1622  * We assume c_cc has already been checked.
1623  */
1624 ttyretype(tp)
1625 	register struct tty *tp;
1626 {
1627 	register char *cp;
1628 	char *nextc();
1629 	int s, c;
1630 
1631 	if (tp->t_cc[VREPRINT] != _POSIX_VDISABLE)
1632 		ttyecho(tp->t_cc[VREPRINT], tp);
1633 	(void) ttyoutput('\n', tp);
1634 	s = spltty();
1635 	/*** XXX *** FIX *** NEXTC IS BROKEN - DOESN'T CHECK QUOTE
1636 	  BIT OF FIRST CHAR ****/
1637 	for (cp = tp->t_canq.c_cf, c=(cp?*cp:0); cp; cp = nextc(&tp->t_canq, cp, &c)) {
1638 		ttyecho(c, tp);
1639 	}
1640 	for (cp = tp->t_rawq.c_cf, c=(cp?*cp:0); cp; cp = nextc(&tp->t_rawq, cp, &c)) {
1641 		ttyecho(c, tp);
1642 	}
1643 	tp->t_state &= ~TS_ERASE;
1644 	splx(s);
1645 	tp->t_rocount = tp->t_rawq.c_cc;
1646 	tp->t_rocol = 0;
1647 }
1648 
1649 /*
1650  * Echo a typed character to the terminal.
1651  */
1652 ttyecho(c, tp)
1653 	register c;
1654 	register struct tty *tp;
1655 {
1656 	if ((tp->t_state&TS_CNTTB) == 0)
1657 		tp->t_lflag &= ~FLUSHO;
1658 	if ((tp->t_lflag&ECHO) == 0 && ((tp->t_lflag&ECHONL) == 0 || c == '\n'))
1659 		return;
1660 	if (tp->t_lflag&ECHOCTL) {
1661 		if ((c&TTY_CHARMASK) <= 037 && c != '\t' && c != '\n' ||
1662 		    c == 0177) {
1663 			(void) ttyoutput('^', tp);
1664 			c &= TTY_CHARMASK;
1665 			if (c == 0177)
1666 				c = '?';
1667 			else
1668 				c += 'A' - 1;
1669 		}
1670 	}
1671 	(void) ttyoutput(c, tp);
1672 }
1673 
1674 /*
1675  * send string cp to tp
1676  */
1677 ttyoutstr(cp, tp)
1678 	register char *cp;
1679 	register struct tty *tp;
1680 {
1681 	register char c;
1682 
1683 	while (c = *cp++)
1684 		(void) ttyoutput(c, tp);
1685 }
1686 
1687 ttwakeup(tp)
1688 	struct tty *tp;
1689 {
1690 
1691 	if (tp->t_rsel) {
1692 		selwakeup(tp->t_rsel, tp->t_state&TS_RCOLL);
1693 		tp->t_state &= ~TS_RCOLL;
1694 		tp->t_rsel = 0;
1695 	}
1696 	if (tp->t_state & TS_ASYNC)
1697 		pgsignal(tp->t_pgrp, SIGIO);
1698 	wakeup((caddr_t)&tp->t_rawq);
1699 }
1700 
1701 /*
1702  * set tty hi and low water marks
1703  *
1704  * Try to arrange the dynamics so there's about one second
1705  * from hi to low water.
1706  *
1707  */
1708 ttsetwater(tp)
1709 	struct tty *tp;
1710 {
1711 	register cps = tp->t_ospeed / 10;
1712 	register x;
1713 
1714 #define clamp(x, h, l) ((x)>h ? h : ((x)<l) ? l : (x))
1715 	tp->t_lowat = x = clamp(cps/2, TTMAXLOWAT, TTMINLOWAT);
1716 	x += cps;
1717 	x = clamp(x, TTMAXHIWAT, TTMINHIWAT);
1718 	tp->t_hiwat = roundup(x, CBSIZE);
1719 #undef clamp
1720 }
1721 
1722 ttspeedtab(speed, table)
1723 	struct speedtab table[];
1724 {
1725 	register int i;
1726 
1727 	for (i = 0; table[i].sp_speed != -1; i++)
1728 		if (table[i].sp_speed == speed)
1729 			return(table[i].sp_code);
1730 	return(-1);
1731 }
1732 
1733 int ttyhostname = 0;
1734 /*
1735  * (^T)
1736  * Report on state of foreground process group.
1737  */
1738 ttyinfo(tp)
1739 	struct tty *tp;
1740 {
1741 	register struct proc *p, *pick = NULL;
1742 	register char *cp = hostname;
1743 	int x, s;
1744 	struct timeval utime, stime;
1745 #define	pgtok(a)	((a)/(1024/NBPG))
1746 
1747 	if (ttycheckoutq(tp,0) == 0)
1748 		return;
1749 	/*
1750 	 * hostname
1751 	 */
1752 	if (ttyhostname) {
1753 		if (*cp == '\0')
1754 			ttyprintf(tp, "amnesia");
1755 		else
1756 			while (*cp && *cp != '.')
1757 				tputchar(*cp++, tp);
1758 		tputchar(' ');
1759 	}
1760 	/*
1761 	 * load average
1762 	 */
1763 	x = (averunnable[0] * 100 + FSCALE/2) >> FSHIFT;
1764 	ttyprintf(tp, "load: %d.", x/100);
1765 	ttyoutint(x%100, 10, 2, tp);
1766 	if (tp->t_session == NULL)
1767 		ttyprintf(tp, " not a controlling terminal\n");
1768 	else if (tp->t_pgrp == NULL)
1769 		ttyprintf(tp, " no foreground process group\n");
1770 	else if ((p = tp->t_pgrp->pg_mem) == NULL)
1771 		ttyprintf(tp, " empty foreground process group\n");
1772 	else {
1773 		/* pick interesting process */
1774 		for (; p != NULL; p = p->p_pgrpnxt) {
1775 			if (proc_compare(pick, p))
1776 				pick = p;
1777 		}
1778 		ttyprintf(tp, "  cmd: %s %d [%s] ",
1779 			pick->p_comm, pick->p_pid,
1780 			pick->p_wmesg ? pick->p_wmesg : "running");
1781 		/*
1782 		 * cpu time
1783 		 */
1784 		if (u.u_procp == pick)
1785 			s = splclock();
1786 		utime = pick->p_utime;
1787 		stime = pick->p_stime;
1788 		if (u.u_procp == pick)
1789 			splx(s);
1790 		/* user time */
1791 		x = (utime.tv_usec + 5000) / 10000; /* scale to 100's */
1792 		ttyoutint(utime.tv_sec, 10, 1, tp);
1793 		tputchar('.', tp);
1794 		ttyoutint(x, 10, 2, tp);
1795 		tputchar('u', tp);
1796 		tputchar(' ', tp);
1797 		/* system time */
1798 		x = (stime.tv_usec + 5000) / 10000; /* scale to 100's */
1799 		ttyoutint(stime.tv_sec, 10, 1, tp);
1800 		tputchar('.', tp);
1801 		ttyoutint(x, 10, 2, tp);
1802 		tputchar('s', tp);
1803 		tputchar(' ', tp);
1804 		/*
1805 		 * pctcpu
1806 		 */
1807 		x = pick->p_pctcpu * 10000 + FSCALE/2 >> FSHIFT;
1808 		ttyoutint(x/100, 10, 1, tp);
1809 #ifdef notdef	/* do we really want this ??? */
1810 		tputchar('.', tp);
1811 		ttyoutint(x%100, 10, 2, tp);
1812 #endif
1813 		ttyprintf(tp, "%% %dk\n", pgtok(pick->p_ssize + pick->p_dsize));
1814 	}
1815 	tp->t_rocount = 0;	/* so pending input will be retyped if BS */
1816 }
1817 
1818 ttyoutint(n, base, min, tp)
1819 	register int n, base, min;
1820 	register struct tty *tp;
1821 {
1822 	char info[16];
1823 	register char *p = info;
1824 
1825 	while (--min >= 0 || n) {
1826 		*p++ = "0123456789abcdef"[n%base];
1827 		n /= base;
1828 	}
1829 	while (p > info)
1830 		ttyoutput(*--p, tp);
1831 }
1832 
1833 /*
1834  * Returns 1 if p2 is "better" than p1
1835  *
1836  * The algorithm for picking the "interesting" process is thus:
1837  *
1838  *	1) (Only foreground processes are eligable - implied)
1839  *	2) Runnable processes are favored over anything
1840  *	   else.  The runner with the highest cpu
1841  *	   utilization is picked (p_cpu).  Ties are
1842  *	   broken by picking the highest pid.
1843  *	3  Next, the sleeper with the shortest sleep
1844  *	   time is favored.  With ties, we pick out
1845  *	   just "short-term" sleepers (SSINTR == 0).
1846  *	   Further ties are broken by picking the highest
1847  *	   pid.
1848  *
1849  */
1850 #define isrun(p)	(((p)->p_stat == SRUN) || ((p)->p_stat == SIDL))
1851 proc_compare(p1, p2)
1852 	register struct proc *p1, *p2;
1853 {
1854 
1855 	if (p1 == NULL)
1856 		return (1);
1857 	/*
1858 	 * see if at least one of them is runnable
1859 	 */
1860 	switch (isrun(p1)<<1 | isrun(p2)) {
1861 	case 0x01:
1862 		return (1);
1863 	case 0x10:
1864 		return (0);
1865 	case 0x11:
1866 		/*
1867 		 * tie - favor one with highest recent cpu utilization
1868 		 */
1869 		if (p2->p_cpu > p1->p_cpu)
1870 			return (1);
1871 		if (p1->p_cpu > p2->p_cpu)
1872 			return (0);
1873 		return (p2->p_pid > p1->p_pid);	/* tie - return highest pid */
1874 	}
1875 	/*
1876 	 * pick the one with the smallest sleep time
1877 	 */
1878 	if (p2->p_slptime > p1->p_slptime)
1879 		return (0);
1880 	if (p1->p_slptime > p2->p_slptime)
1881 		return (1);
1882 	/*
1883 	 * favor one sleeping in a non-interruptible sleep
1884 	 */
1885 	if (p1->p_flag&SSINTR && (p2->p_flag&SSINTR) == 0)
1886 		return (1);
1887 	if (p2->p_flag&SSINTR && (p1->p_flag&SSINTR) == 0)
1888 		return (0);
1889 	return(p2->p_pid > p1->p_pid);		/* tie - return highest pid */
1890 }
1891 #define TOTTY	0x2	/* XXX should be in header */
1892 /*VARARGS2*/
1893 ttyprintf(tp, fmt, x1)
1894 	struct tty *tp;
1895 	char *fmt;
1896 	unsigned x1;
1897 {
1898 	prf(fmt, &x1, TOTTY, (caddr_t)tp);
1899 }
1900 
1901 /*
1902  * Output char to tty; console putchar style.
1903  */
1904 tputchar(c, tp)
1905 	int c;
1906 	struct tty *tp;
1907 {
1908 	register s = spltty();
1909 
1910 	if ((tp->t_state & (TS_CARR_ON | TS_ISOPEN))
1911 	    == (TS_CARR_ON | TS_ISOPEN)) {
1912 		if (c == '\n')
1913 			(void) ttyoutput('\r', tp);
1914 		(void) ttyoutput(c, tp);
1915 		ttstart(tp);
1916 		splx(s);
1917 		return (0);
1918 	}
1919 	splx(s);
1920 	return (-1);
1921 }
1922