xref: /original-bsd/sys/kern/tty.c (revision d25e1985)
1 /*	tty.c	3.20	10/01/80	*/
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/mx.h"
13 #include "../h/inode.h"
14 #include "../h/file.h"
15 #include "../h/reg.h"
16 #include "../h/conf.h"
17 #include "../h/buf.h"
18 #include "../h/dk.h"
19 
20 char	partab[];
21 
22 /*
23  * When running dz's using only SAE (silo alarm) on input
24  * it is necessary to call dzrint() at clock interrupt time.
25  * This is unsafe unless spl5()s in tty code are changed to
26  * spl6()s to block clock interrupts.  Note that the dh driver
27  * currently in use works the same way as the dz, even though
28  * we could try to more intelligently manage its silo.
29  * Thus don't take this out if you have no dz's unless you
30  * change clock.c and dhtimer().
31  */
32 #define	spl5	spl6
33 
34 /*
35  * Input mapping table-- if an entry is non-zero, when the
36  * corresponding character is typed preceded by "\" the escape
37  * sequence is replaced by the table value.  Mostly used for
38  * upper-case only terminals.
39  */
40 
41 char	maptab[] ={
42 	000,000,000,000,000,000,000,000,
43 	000,000,000,000,000,000,000,000,
44 	000,000,000,000,000,000,000,000,
45 	000,000,000,000,000,000,000,000,
46 	000,'|',000,000,000,000,000,'`',
47 	'{','}',000,000,000,000,000,000,
48 	000,000,000,000,000,000,000,000,
49 	000,000,000,000,000,000,000,000,
50 	000,000,000,000,000,000,000,000,
51 	000,000,000,000,000,000,000,000,
52 	000,000,000,000,000,000,000,000,
53 	000,000,000,000,000,000,'~',000,
54 	000,'A','B','C','D','E','F','G',
55 	'H','I','J','K','L','M','N','O',
56 	'P','Q','R','S','T','U','V','W',
57 	'X','Y','Z',000,000,000,000,000,
58 };
59 
60 short	tthiwat[16] =
61    { 100,100,100,100,100,100,100,200,200,400,400,400,650,650,650,650 };
62 short	ttlowat[16] =
63    {  30, 30, 30, 30, 30, 30, 30, 50, 50,120,120,120,125,125,125,125 };
64 
65 #define	OBUFSIZ	100
66 
67 /*
68  * set default control characters.
69  */
70 ttychars(tp)
71 register struct tty *tp;
72 {
73 
74 	tun.t_intrc = CINTR;
75 	tun.t_quitc = CQUIT;
76 	tun.t_startc = CSTART;
77 	tun.t_stopc = CSTOP;
78 	tun.t_eofc = CEOT;
79 	tun.t_brkc = CBRK;
80 	tp->t_erase = CERASE;
81 	tp->t_kill = CKILL;
82 /* begin local */
83 	tlun.t_suspc = CTRL(z);
84 	tlun.t_dsuspc = CTRL(y);
85 	tlun.t_rprntc = CTRL(r);
86 	tlun.t_flushc = CTRL(o);
87 	tlun.t_werasc = CTRL(w);
88 	tlun.t_lnextc = CTRL(v);
89 	tp->t_local = 0;
90 	tp->t_lstate = 0;
91 /* end local */
92 }
93 
94 /*
95  * Wait for output to drain, then flush input waiting.
96  */
97 wflushtty(tp)
98 register struct tty *tp;
99 {
100 
101 	(void) spl5();
102 	while (tp->t_outq.c_cc && tp->t_state&CARR_ON) {
103 		(*tp->t_oproc)(tp);
104 		tp->t_state |= ASLEEP;
105 		sleep((caddr_t)&tp->t_outq, TTOPRI);
106 	}
107 	flushtty(tp, FREAD|FWRITE);
108 	(void) spl0();
109 }
110 
111 /*
112  * flush all TTY queues
113  */
114 flushtty(tp, rw)
115 register struct tty *tp;
116 {
117 	register s;
118 
119 	if (tp->t_line == NETLDISC)
120 		return;
121 	s = spl6();
122 	if (rw & FREAD) {
123 		while (getc(&tp->t_canq) >= 0)
124 			;
125 		wakeup((caddr_t)&tp->t_rawq);
126 	}
127 	if (rw & FWRITE) {
128 		wakeup((caddr_t)&tp->t_outq);
129 		tp->t_state &= ~TTSTOP;
130 		(*cdevsw[major(tp->t_dev)].d_stop)(tp);
131 		while (getc(&tp->t_outq) >= 0)
132 			;
133 	}
134 	if (rw & FREAD) {
135 		while (getc(&tp->t_rawq) >= 0)
136 			;
137 		tp->t_delct = 0;
138 		tp->t_rocount = 0;		/* local */
139 		tp->t_rocol = 0;
140 		tp->t_lstate = 0;
141 	}
142 	splx(s);
143 }
144 
145 /*
146  * Send stop character on input overflow.
147  */
148 ttyblock(tp)
149 register struct tty *tp;
150 {
151 	register x;
152 	x = tp->t_rawq.c_cc + tp->t_canq.c_cc;
153 	if (tp->t_rawq.c_cc > TTYHOG) {
154 		flushtty(tp, FREAD|FWRITE);
155 		tp->t_state &= ~TBLOCK;
156 	}
157 	if (x >= TTYHOG/2) {
158 		if (putc(tun.t_stopc, &tp->t_outq)==0) {
159 			tp->t_state |= TBLOCK;
160 			tp->t_char++;
161 			ttstart(tp);
162 		}
163 	}
164 }
165 
166 /*
167  * Restart typewriter output following a delay
168  * timeout.
169  * The name of the routine is passed to the timeout
170  * subroutine and it is called during a clock interrupt.
171  */
172 ttrstrt(tp)
173 register struct tty *tp;
174 {
175 
176 	tp->t_state &= ~TIMEOUT;
177 	ttstart(tp);
178 }
179 
180 /*
181  * Start output on the typewriter. It is used from the top half
182  * after some characters have been put on the output queue,
183  * from the interrupt routine to transmit the next
184  * character, and after a timeout has finished.
185  */
186 ttstart(tp)
187 register struct tty *tp;
188 {
189 	register s;
190 
191 	s = spl5();
192 	if((tp->t_state&(TIMEOUT|TTSTOP|BUSY)) == 0)
193 		(*tp->t_oproc)(tp);
194 	splx(s);
195 }
196 
197 /*
198  * Common code for tty ioctls.
199  */
200 ttioctl(com, tp, addr, dev, flag)
201 register struct tty *tp;
202 caddr_t addr;
203 {
204 	unsigned t;
205 	struct sgttyb iocb;
206 	struct clist tq;
207 	extern int nldisp;
208 	register c;
209 	int temp;
210 
211 	/*
212 	 * This is especially so that isatty() will
213 	 * fail when carrier is gone.
214 	 */
215 	if ((tp->t_state&CARR_ON) == 0) {
216 		u.u_error = EBADF;
217 		return (1);
218 	}
219 
220 	/*
221 	 * If the ioctl involves modification,
222 	 * insist on being able to write the device,
223 	 * and hang if in the background.
224 	 */
225 	switch(com) {
226 
227 	case TIOCSETD:
228 	case TIOCSETP:
229 	case TIOCSETN:
230 	case TIOCFLUSH:
231 	case TIOCSETC:
232 	case TIOCSLTC:
233 	case TIOCSPGRP:
234 	case TIOCLBIS:
235 	case TIOCLBIC:
236 	case TIOCLSET:
237 	case TIOCSTI:
238 /* this is reasonable, but impractical...
239 		if ((flag & FWRITE) == 0) {
240 			u.u_error = EBADF;
241 			return (1);
242 		}
243  */
244 		while (tp->t_line == NTTYDISC &&
245 		   u.u_procp->p_pgrp != tp->t_pgrp && tp == u.u_ttyp &&
246 		   (u.u_procp->p_flag&SVFORK) == 0 &&
247 		   u.u_signal[SIGTTOU] != SIG_IGN &&
248 		   u.u_signal[SIGTTOU] != SIG_HOLD &&
249 		   (u.u_procp->p_flag&SDETACH)==0) {
250 			gsignal(u.u_procp->p_pgrp, SIGTTOU);
251 			sleep((caddr_t)&lbolt, TTOPRI);
252 		}
253 		break;
254 	}
255 
256 	/*
257 	 * Process the ioctl.
258 	 */
259 	switch(com) {
260 
261 	/*
262 	 * Get discipline number
263 	 */
264 	case TIOCGETD:
265 		t = tp->t_line;
266 		if (copyout((caddr_t)&t, addr, sizeof(t)))
267 			u.u_error = EFAULT;
268 		break;
269 
270 	/*
271 	 * Set line discipline
272 	 */
273 	case TIOCSETD:
274 		if (copyin(addr, (caddr_t)&t, sizeof(t))) {
275 			u.u_error = EFAULT;
276 			break;
277 		}
278 		if (t >= nldisp) {
279 			u.u_error = ENXIO;
280 			break;
281 		}
282 		(void) spl5();
283 		if (tp->t_line)
284 			(*linesw[tp->t_line].l_close)(tp);
285 		if (t)
286 			(*linesw[t].l_open)(dev, tp, addr);
287 		if (u.u_error==0)
288 			tp->t_line = t;
289 		(void) spl0();
290 		break;
291 
292 	/*
293 	 * Prevent more opens on channel
294 	 */
295 	case TIOCEXCL:
296 		tp->t_state |= XCLUDE;
297 		break;
298 
299 	case TIOCNXCL:
300 		tp->t_state &= ~XCLUDE;
301 		break;
302 
303 	/*
304 	 * Set new parameters
305 	 */
306 	case TIOCSETP:
307 	case TIOCSETN:
308 		if (copyin(addr, (caddr_t)&iocb, sizeof(iocb))) {
309 			u.u_error = EFAULT;
310 			return(1);
311 		}
312 		(void) spl5();
313 		if (tp->t_line == 0) {
314 			if (com == TIOCSETP)
315 				wflushtty(tp);
316 			while (canon(tp)>=0)
317 				;
318 #ifdef notdef
319 			wakeup((caddr_t)&tp->t_rawq);
320 #endif
321 		} else if (tp->t_line == NTTYDISC) {
322 			if (tp->t_flags&RAW || iocb.sg_flags&RAW ||
323 			    com == TIOCSETP)
324 				wflushtty(tp);
325 			else if ((tp->t_flags&CBREAK) != (iocb.sg_flags&CBREAK)) {
326 				if (iocb.sg_flags & CBREAK) {
327 					catq(&tp->t_rawq, &tp->t_canq);
328 					tq = tp->t_rawq;
329 					tp->t_rawq = tp->t_canq;
330 					tp->t_canq = tq;
331 				} else {
332 					tp->t_local |= LPENDIN;
333 					if (tp->t_canq.c_cc)
334 						panic("ioccom canq");
335 #ifdef notdef
336 					if (tp->t_chan)
337 						(void) sdata(tp->t_chan);
338 					else
339 #endif
340 						wakeup((caddr_t)&tp->t_rawq);
341 				}
342 			}
343 		}
344 		if ((tp->t_state&SPEEDS)==0) {
345 			tp->t_ispeed = iocb.sg_ispeed;
346 			tp->t_ospeed = iocb.sg_ospeed;
347 		}
348 		tp->t_erase = iocb.sg_erase;
349 		tp->t_kill = iocb.sg_kill;
350 		tp->t_flags = iocb.sg_flags;
351 		(void) spl0();
352 		break;
353 
354 	/*
355 	 * Send current parameters to user
356 	 */
357 	case TIOCGETP:
358 		iocb.sg_ispeed = tp->t_ispeed;
359 		iocb.sg_ospeed = tp->t_ospeed;
360 		iocb.sg_erase = tp->t_erase;
361 		iocb.sg_kill = tp->t_kill;
362 		iocb.sg_flags = tp->t_flags;
363 		if (copyout((caddr_t)&iocb, addr, sizeof(iocb)))
364 			u.u_error = EFAULT;
365 		break;
366 
367 	/*
368 	 * Hang up line on last close
369 	 */
370 	case TIOCHPCL:
371 		tp->t_state |= HUPCLS;
372 		break;
373 
374 	case TIOCFLUSH:
375 		flushtty(tp, FREAD|FWRITE);
376 		break;
377 
378 	/*
379 	 * Ioctl entries to line discipline
380 	 */
381 	case DIOCSETP:
382 	case DIOCGETP:
383 		if ((*linesw[tp->t_line].l_ioctl)(com, tp, addr))
384 			u.u_error = ENOTTY;
385 		break;
386 
387 	/*
388 	 * Set and fetch special characters
389 	 */
390 	case TIOCSETC:
391 		if (copyin(addr, (caddr_t)&tun, sizeof(struct tchars)))
392 			u.u_error = EFAULT;
393 		break;
394 
395 	case TIOCGETC:
396 		if (copyout((caddr_t)&tun, addr, sizeof(struct tchars)))
397 			u.u_error = EFAULT;
398 		break;
399 
400 /* local ioctls */
401 	/*
402 	 * Set/get local special characters.
403 	 */
404 	case TIOCSLTC:
405 		if (copyin(addr, (caddr_t)&tlun, sizeof (struct ltchars)))
406 			u.u_error = EFAULT;
407 		break;
408 
409 	case TIOCGLTC:
410 		if (copyout((caddr_t)&tlun, addr, sizeof (struct ltchars)))
411 			u.u_error = EFAULT;
412 		break;
413 
414 	/*
415 	 * Return number of characters immediately available.
416 	 */
417 	case FIONREAD: {
418 		off_t nread;
419 
420 		switch (tp->t_line) {
421 
422 		case NETLDISC:
423 			nread = tp->t_rec ? tp->t_inbuf : 0;
424 			break;
425 
426 		case 0:
427 			(void) spl5();
428 			while (canon(tp)>=0)
429 				;
430 			(void) spl0();
431 			/* fall into ... */
432 
433 		case NTTYDISC:
434 			nread = tp->t_canq.c_cc;
435 			if (tp->t_flags & (RAW|CBREAK))
436 				nread += tp->t_rawq.c_cc;
437 			break;
438 
439 		}
440 		if (copyout((caddr_t)&nread, addr, sizeof (off_t)))
441 			u.u_error = EFAULT;
442 		break;
443 		}
444 
445 	/*
446 	 * Should allow SPGRP and GPGRP only if tty open for reading.
447 	 */
448 	case TIOCSPGRP:
449 		if (copyin(addr, (caddr_t)&tp->t_pgrp, sizeof (tp->t_pgrp)))
450 			u.u_error = EFAULT;
451 		break;
452 
453 	case TIOCGPGRP:
454 		if (copyout((caddr_t)&tp->t_pgrp, addr, sizeof(tp->t_pgrp)))
455 			u.u_error = EFAULT;
456 		break;
457 
458 	/*
459 	 * Modify local mode word.
460 	 */
461 	case TIOCLBIS:
462 		if (copyin(addr, (caddr_t)&temp, sizeof (tp->t_local)))
463 			u.u_error = EFAULT;
464 		else
465 			tp->t_local |= temp;
466 		break;
467 
468 	case TIOCLBIC:
469 		if (copyin(addr, (caddr_t)&temp, sizeof (tp->t_local)))
470 			u.u_error = EFAULT;
471 		else
472 			tp->t_local &= ~temp;
473 		break;
474 
475 	case TIOCLSET:
476 		if (copyin(addr, (caddr_t)&temp, sizeof (tp->t_local)))
477 			u.u_error = EFAULT;
478 		else
479 			tp->t_local = temp;
480 		break;
481 
482 	case TIOCLGET:
483 		if (copyout((caddr_t)&tp->t_local, addr, sizeof(tp->t_local)))
484 			u.u_error = EFAULT;
485 		break;
486 
487 	/*
488 	 * Return number of characters in
489 	 * the output.
490 	 */
491 	case TIOCOUTQ:
492 		if (copyout((caddr_t)&tp->t_outq.c_cc, addr, sizeof(tp->t_outq.c_cc)))
493 			u.u_error = EFAULT;
494 		break;
495 
496 	/*
497 	 * Simulate typing of a character at the terminal.
498 	 */
499 	case TIOCSTI:
500 		c = fubyte(addr);
501 		if (u.u_uid && u.u_ttyp != tp || c < 0)
502 			u.u_error = EFAULT;
503 		else
504 			(*linesw[tp->t_line].l_rint)(c, tp);
505 		break;
506 /* end of locals */
507 
508 	default:
509 		return(0);
510 	}
511 	return(1);
512 }
513