xref: /csrg-svn/sys/kern/tty.c (revision 5622)
1 /*	tty.c	4.20	82/01/25	*/
2 
3 /*
4  * TTY subroutines common to more than one line discipline
5  */
6 #include "../h/param.h"
7 #include "../h/systm.h"
8 #include "../h/dir.h"
9 #include "../h/user.h"
10 #include "../h/tty.h"
11 #include "../h/proc.h"
12 #include "../h/inode.h"
13 #include "../h/file.h"
14 #include "../h/reg.h"
15 #include "../h/conf.h"
16 #include "../h/buf.h"
17 #include "../h/dk.h"
18 
19 char	partab[];
20 
21 /*
22  * Input mapping table-- if an entry is non-zero, when the
23  * corresponding character is typed preceded by "\" the escape
24  * sequence is replaced by the table value.  Mostly used for
25  * upper-case only terminals.
26  */
27 
28 char	maptab[] ={
29 	000,000,000,000,000,000,000,000,
30 	000,000,000,000,000,000,000,000,
31 	000,000,000,000,000,000,000,000,
32 	000,000,000,000,000,000,000,000,
33 	000,'|',000,000,000,000,000,'`',
34 	'{','}',000,000,000,000,000,000,
35 	000,000,000,000,000,000,000,000,
36 	000,000,000,000,000,000,000,000,
37 	000,000,000,000,000,000,000,000,
38 	000,000,000,000,000,000,000,000,
39 	000,000,000,000,000,000,000,000,
40 	000,000,000,000,000,000,'~',000,
41 	000,'A','B','C','D','E','F','G',
42 	'H','I','J','K','L','M','N','O',
43 	'P','Q','R','S','T','U','V','W',
44 	'X','Y','Z',000,000,000,000,000,
45 };
46 
47 short	tthiwat[16] =
48    { 100,100,100,100,100,100,100,200,200,400,400,400,650,650,650,650 };
49 short	ttlowat[16] =
50    {  30, 30, 30, 30, 30, 30, 30, 50, 50,120,120,120,125,125,125,125 };
51 
52 #define	OBUFSIZ	100
53 
54 /*
55  * set default control characters.
56  */
57 ttychars(tp)
58 register struct tty *tp;
59 {
60 
61 	tun.t_intrc = CINTR;
62 	tun.t_quitc = CQUIT;
63 	tun.t_startc = CSTART;
64 	tun.t_stopc = CSTOP;
65 	tun.t_eofc = CEOT;
66 	tun.t_brkc = CBRK;
67 	tp->t_erase = CERASE;
68 	tp->t_kill = CKILL;
69 /* begin local */
70 	tlun.t_suspc = CTRL(z);
71 	tlun.t_dsuspc = CTRL(y);
72 	tlun.t_rprntc = CTRL(r);
73 	tlun.t_flushc = CTRL(o);
74 	tlun.t_werasc = CTRL(w);
75 	tlun.t_lnextc = CTRL(v);
76 	tp->t_local = 0;
77 	tp->t_lstate = 0;
78 /* end local */
79 }
80 
81 /*
82  * Wait for output to drain, then flush input waiting.
83  */
84 wflushtty(tp)
85 	register struct tty *tp;
86 {
87 
88 	(void) spl5();
89 	while (tp->t_outq.c_cc && tp->t_state&TS_CARR_ON
90 	    && tp->t_oproc) {		/* kludge for pty */
91 		(*tp->t_oproc)(tp);
92 		tp->t_state |= TS_ASLEEP;
93 		sleep((caddr_t)&tp->t_outq, TTOPRI);
94 	}
95 	flushtty(tp, FREAD);
96 	(void) spl0();
97 }
98 
99 /*
100  * flush all TTY queues
101  */
102 flushtty(tp, rw)
103 register struct tty *tp;
104 {
105 	register s;
106 
107 	s = spl6();
108 	if (rw & FREAD) {
109 		while (getc(&tp->t_canq) >= 0)
110 			;
111 		wakeup((caddr_t)&tp->t_rawq);
112 	}
113 	if (rw & FWRITE) {
114 		wakeup((caddr_t)&tp->t_outq);
115 		tp->t_state &= ~TS_TTSTOP;
116 		(*cdevsw[major(tp->t_dev)].d_stop)(tp, rw);
117 		while (getc(&tp->t_outq) >= 0)
118 			;
119 	}
120 	if (rw & FREAD) {
121 		while (getc(&tp->t_rawq) >= 0)
122 			;
123 		tp->t_delct = 0;
124 		tp->t_rocount = 0;		/* local */
125 		tp->t_rocol = 0;
126 		tp->t_lstate = 0;
127 	}
128 	splx(s);
129 }
130 
131 /*
132  * Send stop character on input overflow.
133  */
134 ttyblock(tp)
135 register struct tty *tp;
136 {
137 	register x;
138 	x = tp->t_rawq.c_cc + tp->t_canq.c_cc;
139 	if (tp->t_rawq.c_cc > TTYHOG) {
140 		flushtty(tp, FREAD|FWRITE);
141 		tp->t_state &= ~TS_TBLOCK;
142 	}
143 	if (x >= TTYHOG/2) {
144 		if (putc(tun.t_stopc, &tp->t_outq)==0) {
145 			tp->t_state |= TS_TBLOCK;
146 			tp->t_char++;
147 			ttstart(tp);
148 		}
149 	}
150 }
151 
152 /*
153  * Restart typewriter output following a delay
154  * timeout.
155  * The name of the routine is passed to the timeout
156  * subroutine and it is called during a clock interrupt.
157  */
158 ttrstrt(tp)
159 register struct tty *tp;
160 {
161 
162 	if (tp == 0) {
163 		printf("ttrstrt: arg was 0!\n");
164 		return;
165 	}
166 	tp->t_state &= ~TS_TIMEOUT;
167 	ttstart(tp);
168 }
169 
170 /*
171  * Start output on the typewriter. It is used from the top half
172  * after some characters have been put on the output queue,
173  * from the interrupt routine to transmit the next
174  * character, and after a timeout has finished.
175  */
176 ttstart(tp)
177 register struct tty *tp;
178 {
179 	register s;
180 
181 	s = spl5();
182 	if((tp->t_state&(TS_TIMEOUT|TS_TTSTOP|TS_BUSY)) == 0 &&
183 	    tp->t_oproc)		/* kludge for pty */
184 		(*tp->t_oproc)(tp);
185 	splx(s);
186 }
187 
188 /*
189  * Common code for tty ioctls.
190  */
191 /*ARGSUSED*/
192 ttioctl(tp, com, addr, flag)
193 register struct tty *tp;
194 caddr_t addr;
195 {
196 	int dev;
197 	unsigned t;
198 	struct sgttyb iocb;
199 	struct clist tq;
200 	extern int nldisp;
201 	register c;
202 	int temp;
203 
204 	/*
205 	 * This is especially so that isatty() will
206 	 * fail when carrier is gone.
207 	 */
208 	if ((tp->t_state&TS_CARR_ON) == 0) {
209 		u.u_error = EBADF;
210 		return (1);
211 	}
212 
213 	dev = tp->t_dev;
214 	/*
215 	 * If the ioctl involves modification,
216 	 * insist on being able to write the device,
217 	 * and hang if in the background.
218 	 */
219 	switch(com) {
220 
221 	case TIOCSETD:
222 	case TIOCSETP:
223 	case TIOCSETN:
224 	case TIOCFLUSH:
225 	case TIOCSETC:
226 	case TIOCSLTC:
227 	case TIOCSPGRP:
228 	case TIOCLBIS:
229 	case TIOCLBIC:
230 	case TIOCLSET:
231 	case TIOCSTI:
232 /* this is reasonable, but impractical...
233 		if ((flag & FWRITE) == 0) {
234 			u.u_error = EBADF;
235 			return (1);
236 		}
237  */
238 		while (tp->t_line == NTTYDISC &&
239 		   u.u_procp->p_pgrp != tp->t_pgrp && tp == u.u_ttyp &&
240 		   (u.u_procp->p_flag&SVFORK) == 0 &&
241 		   u.u_signal[SIGTTOU] != SIG_IGN &&
242 		   u.u_signal[SIGTTOU] != SIG_HOLD &&
243 		   (u.u_procp->p_flag&SDETACH)==0) {
244 			gsignal(u.u_procp->p_pgrp, SIGTTOU);
245 			sleep((caddr_t)&lbolt, TTOPRI);
246 		}
247 		break;
248 	}
249 
250 	/*
251 	 * Process the ioctl.
252 	 */
253 	switch(com) {
254 
255 	/*
256 	 * Get discipline number
257 	 */
258 	case TIOCGETD:
259 		t = tp->t_line;
260 		if (copyout((caddr_t)&t, addr, sizeof(t)))
261 			u.u_error = EFAULT;
262 		break;
263 
264 	/*
265 	 * Set line discipline
266 	 */
267 	case TIOCSETD:
268 		if (copyin(addr, (caddr_t)&t, sizeof(t))) {
269 			u.u_error = EFAULT;
270 			break;
271 		}
272 		if (t >= nldisp) {
273 			u.u_error = ENXIO;
274 			break;
275 		}
276 		(void) spl5();
277 		if (tp->t_line)
278 			(*linesw[tp->t_line].l_close)(tp);
279 		if (t)
280 			(*linesw[t].l_open)(dev, tp, addr);
281 		if (u.u_error==0)
282 			tp->t_line = t;
283 		(void) spl0();
284 		break;
285 
286 	/*
287 	 * Prevent more opens on channel
288 	 */
289 	case TIOCEXCL:
290 		tp->t_state |= TS_XCLUDE;
291 		break;
292 
293 	case TIOCNXCL:
294 		tp->t_state &= ~TS_XCLUDE;
295 		break;
296 
297 	/*
298 	 * Set new parameters
299 	 */
300 	case TIOCSETP:
301 	case TIOCSETN:
302 		if (copyin(addr, (caddr_t)&iocb, sizeof(iocb))) {
303 			u.u_error = EFAULT;
304 			return(1);
305 		}
306 		(void) spl5();
307 		if (tp->t_flags&RAW || iocb.sg_flags&RAW ||
308 		    com == TIOCSETP)
309 			wflushtty(tp);
310 		else if ((tp->t_flags&CBREAK) != (iocb.sg_flags&CBREAK)) {
311 			if (iocb.sg_flags & CBREAK) {
312 				catq(&tp->t_rawq, &tp->t_canq);
313 				tq = tp->t_rawq;
314 				tp->t_rawq = tp->t_canq;
315 				tp->t_canq = tq;
316 			} else {
317 				tp->t_local |= LPENDIN;
318 				ttwakeup(tp);
319 			}
320 		}
321 		tp->t_ispeed = iocb.sg_ispeed;
322 		tp->t_ospeed = iocb.sg_ospeed;
323 		tp->t_erase = iocb.sg_erase;
324 		tp->t_kill = iocb.sg_kill;
325 		tp->t_flags = iocb.sg_flags;
326 		if (tp->t_flags & RAW) {
327 			tp->t_state &= ~TS_TTSTOP;
328 			ttstart(tp);
329 		}
330 		(void) spl0();
331 		break;
332 
333 	/*
334 	 * Send current parameters to user
335 	 */
336 	case TIOCGETP:
337 		iocb.sg_ispeed = tp->t_ispeed;
338 		iocb.sg_ospeed = tp->t_ospeed;
339 		iocb.sg_erase = tp->t_erase;
340 		iocb.sg_kill = tp->t_kill;
341 		iocb.sg_flags = tp->t_flags;
342 		if (copyout((caddr_t)&iocb, addr, sizeof(iocb)))
343 			u.u_error = EFAULT;
344 		break;
345 
346 	/*
347 	 * Hang up line on last close
348 	 */
349 	case TIOCHPCL:
350 		tp->t_state |= TS_HUPCLS;
351 		break;
352 
353 	case TIOCFLUSH: {
354 		int flags;
355 		if (addr == 0)
356 			flags = FREAD|FWRITE;
357 		else if (copyin(addr, (caddr_t)&flags, sizeof (flags))) {
358 			u.u_error = EFAULT;
359 			return(1);
360 		}
361 		flushtty(tp, flags);
362 		break;
363 	}
364 
365 	case FIONBIO: {
366 		int nbio;
367 		if (copyin(addr, (caddr_t)&nbio, sizeof (nbio))) {
368 			u.u_error = EFAULT;
369 			return(1);
370 		}
371 		if (nbio)
372 			tp->t_state |= TS_NBIO;
373 		else
374 			tp->t_state &= ~TS_NBIO;
375 		break;
376 	}
377 
378 	/*
379 	 * Set and fetch special characters
380 	 */
381 	case TIOCSETC:
382 		if (copyin(addr, (caddr_t)&tun, sizeof(struct tchars)))
383 			u.u_error = EFAULT;
384 		break;
385 
386 	case TIOCGETC:
387 		if (copyout((caddr_t)&tun, addr, sizeof(struct tchars)))
388 			u.u_error = EFAULT;
389 		break;
390 
391 /* local ioctls */
392 	/*
393 	 * Set/get local special characters.
394 	 */
395 	case TIOCSLTC:
396 		if (copyin(addr, (caddr_t)&tlun, sizeof (struct ltchars)))
397 			u.u_error = EFAULT;
398 		break;
399 
400 	case TIOCGLTC:
401 		if (copyout((caddr_t)&tlun, addr, sizeof (struct ltchars)))
402 			u.u_error = EFAULT;
403 		break;
404 
405 	/*
406 	 * Return number of characters immediately available.
407 	 */
408 	case FIONREAD: {
409 		off_t nread = ttnread(tp);
410 		if (copyout((caddr_t)&nread, addr, sizeof (off_t)))
411 			u.u_error = EFAULT;
412 		break;
413 		}
414 
415 	/*
416 	 * Should allow SPGRP and GPGRP only if tty open for reading.
417 	 */
418 	case TIOCSPGRP:
419 		if (copyin(addr, (caddr_t)&tp->t_pgrp, sizeof (tp->t_pgrp)))
420 			u.u_error = EFAULT;
421 		break;
422 
423 	case TIOCGPGRP:
424 		if (copyout((caddr_t)&tp->t_pgrp, addr, sizeof(tp->t_pgrp)))
425 			u.u_error = EFAULT;
426 		break;
427 
428 	/*
429 	 * Modify local mode word.
430 	 */
431 	case TIOCLBIS:
432 		if (copyin(addr, (caddr_t)&temp, sizeof (tp->t_local)))
433 			u.u_error = EFAULT;
434 		else
435 			tp->t_local |= temp;
436 		break;
437 
438 	case TIOCLBIC:
439 		if (copyin(addr, (caddr_t)&temp, sizeof (tp->t_local)))
440 			u.u_error = EFAULT;
441 		else
442 			tp->t_local &= ~temp;
443 		break;
444 
445 	case TIOCLSET:
446 		if (copyin(addr, (caddr_t)&temp, sizeof (tp->t_local)))
447 			u.u_error = EFAULT;
448 		else
449 			tp->t_local = temp;
450 		break;
451 
452 	case TIOCLGET:
453 		if (copyout((caddr_t)&tp->t_local, addr, sizeof(tp->t_local)))
454 			u.u_error = EFAULT;
455 		break;
456 
457 	/*
458 	 * Return number of characters in
459 	 * the output.
460 	 */
461 	case TIOCOUTQ:
462 		if (copyout((caddr_t)&tp->t_outq.c_cc, addr, sizeof(tp->t_outq.c_cc)))
463 			u.u_error = EFAULT;
464 		break;
465 
466 	/*
467 	 * Simulate typing of a character at the terminal.
468 	 */
469 	case TIOCSTI:
470 		c = fubyte(addr);
471 		if (u.u_uid && u.u_ttyp != tp || c < 0)
472 			u.u_error = EFAULT;
473 		else
474 			(*linesw[tp->t_line].l_rint)(c, tp);
475 		break;
476 
477 	case TIOCSTOP:
478 		c = spl5();
479 		if ((tp->t_state & TS_TTSTOP) == 0) {
480 			tp->t_state |= TS_TTSTOP;
481 			(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
482 		}
483 		splx(c);
484 		break;
485 
486 	case TIOCSTART:
487 		c = spl5();
488 		if ((tp->t_state & TS_TTSTOP) || (tp->t_local & LFLUSHO)) {
489 			tp->t_state &= ~TS_TTSTOP;
490 			tp->t_local &= ~LFLUSHO;
491 			ttstart(tp);
492 		}
493 		splx(c);
494 		break;
495 
496 /* end of locals */
497 
498 	default:
499 		return(0);
500 	}
501 	return(1);
502 }
503 
504 ttnread(tp)
505 	struct tty *tp;
506 {
507 	int nread = 0;
508 
509 	if (tp->t_local & LPENDIN)
510 		ttypend(tp);
511 	nread = tp->t_canq.c_cc;
512 	if (tp->t_flags & (RAW|CBREAK))
513 		nread += tp->t_rawq.c_cc;
514 	return (nread);
515 }
516 
517 ttselect(dev, rw)
518 	dev_t dev;
519 	int rw;
520 {
521 	register struct tty *tp = &cdevsw[major(dev)].d_ttys[minor(dev)];
522 	int nread;
523 	int s = spl5();
524 
525 	switch (rw) {
526 
527 	case FREAD:
528 		nread = ttnread(tp);
529 		if (nread > 0)
530 			goto win;
531 		if (tp->t_rsel && tp->t_rsel->p_wchan == (caddr_t)&selwait)
532 			tp->t_state |= TS_RCOLL;
533 		else
534 			tp->t_rsel = u.u_procp;
535 		break;
536 
537 	case FWRITE:
538 		if (tp->t_outq.c_cc <= TTLOWAT(tp))
539 			goto win;
540 		if (tp->t_wsel && tp->t_wsel->p_wchan == (caddr_t)&selwait)
541 			tp->t_state |= TS_WCOLL;
542 		else
543 			tp->t_wsel = u.u_procp;
544 		break;
545 	}
546 	splx(s);
547 	return (0);
548 win:
549 	splx(s);
550 	return (1);
551 }
552