1 /*-
2 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Portions of this software were developed under sponsorship from Snow
6 * B.V., the Netherlands.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD: releng/10.3/sys/kern/tty_ttydisc.c 242078 2012-10-25 09:05:21Z ed $");
32
33 #include <sys/param.h>
34 #include <sys/fcntl.h>
35 #include <sys/filio.h>
36 #include <sys/kernel.h>
37 #include <sys/signal.h>
38 #include <sys/sysctl.h>
39 #include <sys/systm.h>
40 #include <sys/tty.h>
41 #include <sys/ttycom.h>
42 #include <sys/ttydefaults.h>
43 #include <sys/uio.h>
44 #include <sys/vnode.h>
45
46 /*
47 * Standard TTYDISC `termios' line discipline.
48 */
49
50 /* Statistics. */
51 static unsigned long tty_nin = 0;
52 SYSCTL_ULONG(_kern, OID_AUTO, tty_nin, CTLFLAG_RD,
53 &tty_nin, 0, "Total amount of bytes received");
54 static unsigned long tty_nout = 0;
55 SYSCTL_ULONG(_kern, OID_AUTO, tty_nout, CTLFLAG_RD,
56 &tty_nout, 0, "Total amount of bytes transmitted");
57
58 /* termios comparison macro's. */
59 #define CMP_CC(v,c) (tp->t_termios.c_cc[v] != _POSIX_VDISABLE && \
60 tp->t_termios.c_cc[v] == (c))
61 #define CMP_FLAG(field,opt) (tp->t_termios.c_ ## field ## flag & (opt))
62
63 /* Characters that cannot be modified through c_cc. */
64 #define CTAB '\t'
65 #define CNL '\n'
66 #define CCR '\r'
67
68 /* Character is a control character. */
69 #define CTL_VALID(c) ((c) == 0x7f || (unsigned char)(c) < 0x20)
70 /* Control character should be processed on echo. */
71 #define CTL_ECHO(c,q) (!(q) && ((c) == CERASE2 || (c) == CTAB || \
72 (c) == CNL || (c) == CCR))
73 /* Control character should be printed using ^X notation. */
74 #define CTL_PRINT(c,q) ((c) == 0x7f || ((unsigned char)(c) < 0x20 && \
75 ((q) || ((c) != CTAB && (c) != CNL))))
76 /* Character is whitespace. */
77 #define CTL_WHITE(c) ((c) == ' ' || (c) == CTAB)
78 /* Character is alphanumeric. */
79 #define CTL_ALNUM(c) (((c) >= '' && (c) <= '9') || \
80 ((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
81
82 #define TTY_STACKBUF 256
83
84 void
85 ttydisc_open(struct tty *tp)
86 {
87 ttydisc_optimize(tp);
88 }
89
90 void
91 ttydisc_close(struct tty *tp)
92 {
93
94 /* Clean up our flags when leaving the discipline. */
95 tp->t_flags &= ~(TF_STOPPED|TF_HIWAT|TF_ZOMBIE);
96
97 /* POSIX states we should flush when close() is called. */
98 ttyinq_flush(&tp->t_inq);
99 ttyoutq_flush(&tp->t_outq);
100
101 if (!tty_gone(tp)) {
102 ttydevsw_inwakeup(tp);
103 ttydevsw_outwakeup(tp);
104 }
105
106 if (ttyhook_hashook(tp, close))
107 ttyhook_close(tp);
108 }
109
110 static int
111 ttydisc_read_canonical(struct tty *tp, struct uio *uio, int ioflag)
112 {
113 char breakc[4] = { CNL }; /* enough to hold \n, VEOF and VEOL. */
114 int error;
115 size_t clen, flen = 0, n = 1;
116 unsigned char lastc = _POSIX_VDISABLE;
117
118 #define BREAK_ADD(c) do { \
119 if (tp->t_termios.c_cc[c] != _POSIX_VDISABLE) \
120 breakc[n++] = tp->t_termios.c_cc[c]; \
121 } while (0)
122 /* Determine which characters we should trigger on. */
123 BREAK_ADD(VEOF);
124 BREAK_ADD(VEOL);
125 #undef BREAK_ADD
126 breakc[n] = '\0';
127
128 do {
129 error = tty_wait_background(tp, curthread, SIGTTIN);
130 if (error)
131 return (error);
132
133 /*
134 * Quite a tricky case: unlike the old TTY
135 * implementation, this implementation copies data back
136 * to userspace in large chunks. Unfortunately, we can't
137 * calculate the line length on beforehand if it crosses
138 * ttyinq_block boundaries, because multiple reads could
139 * then make this code read beyond the newline.
140 *
141 * This is why we limit the read to:
142 * - The size the user has requested
143 * - The blocksize (done in tty_inq.c)
144 * - The amount of bytes until the newline
145 *
146 * This causes the line length to be recalculated after
147 * each block has been copied to userspace. This will
148 * cause the TTY layer to return data in chunks using
149 * the blocksize (except the first and last blocks).
150 */
151 clen = ttyinq_findchar(&tp->t_inq, breakc, uio->uio_resid,
152 &lastc);
153
154 /* No more data. */
155 if (clen == 0) {
156 if (tp->t_flags & TF_ZOMBIE)
157 return (0);
158 else if (ioflag & IO_NDELAY)
159 return (EWOULDBLOCK);
160
161 error = tty_wait(tp, &tp->t_inwait);
162 if (error)
163 return (error);
164 continue;
165 }
166
167 /* Don't send the EOF char back to userspace. */
168 if (CMP_CC(VEOF, lastc))
169 flen = 1;
170
171 MPASS(flen <= clen);
172
173 /* Read and throw away the EOF character. */
174 error = ttyinq_read_uio(&tp->t_inq, tp, uio, clen, flen);
175 if (error)
176 return (error);
177
178 } while (uio->uio_resid > 0 && lastc == _POSIX_VDISABLE);
179
180 return (0);
181 }
182
183 static int
184 ttydisc_read_raw_no_timer(struct tty *tp, struct uio *uio, int ioflag)
185 {
186 size_t vmin = tp->t_termios.c_cc[VMIN];
187 ssize_t oresid = uio->uio_resid;
188 int error;
189
190 MPASS(tp->t_termios.c_cc[VTIME] == 0);
191
192 /*
193 * This routine implements the easy cases of read()s while in
194 * non-canonical mode, namely case B and D, where we don't have
195 * any timers at all.
196 */
197
198 for (;;) {
199 error = tty_wait_background(tp, curthread, SIGTTIN);
200 if (error)
201 return (error);
202
203 error = ttyinq_read_uio(&tp->t_inq, tp, uio,
204 uio->uio_resid, 0);
205 if (error)
206 return (error);
207 if (uio->uio_resid == 0 || (oresid - uio->uio_resid) >= vmin)
208 return (0);
209
210 /* We have to wait for more. */
211 if (tp->t_flags & TF_ZOMBIE)
212 return (0);
213 else if (ioflag & IO_NDELAY)
214 return (EWOULDBLOCK);
215
216 error = tty_wait(tp, &tp->t_inwait);
217 if (error)
218 return (error);
219 }
220 }
221
222 static int
223 ttydisc_read_raw_read_timer(struct tty *tp, struct uio *uio, int ioflag,
224 int oresid)
225 {
226 size_t vmin = MAX(tp->t_termios.c_cc[VMIN], 1);
227 unsigned int vtime = tp->t_termios.c_cc[VTIME];
228 struct timeval end, now, left;
229 int error, hz;
230
231 MPASS(tp->t_termios.c_cc[VTIME] != 0);
232
233 /* Determine when the read should be expired. */
234 end.tv_sec = vtime / 10;
235 end.tv_usec = (vtime % 10) * 100000;
236 getmicrotime(&now);
237 timevaladd(&end, &now);
238
239 for (;;) {
240 error = tty_wait_background(tp, curthread, SIGTTIN);
241 if (error)
242 return (error);
243
244 error = ttyinq_read_uio(&tp->t_inq, tp, uio,
245 uio->uio_resid, 0);
246 if (error)
247 return (error);
248 if (uio->uio_resid == 0 || (oresid - uio->uio_resid) >= vmin)
249 return (0);
250
251 /* Calculate how long we should wait. */
252 getmicrotime(&now);
253 if (timevalcmp(&now, &end, >))
254 return (0);
255 left = end;
256 timevalsub(&left, &now);
257 hz = tvtohz(&left);
258
259 /*
260 * We have to wait for more. If the timer expires, we
261 * should return a 0-byte read.
262 */
263 if (tp->t_flags & TF_ZOMBIE)
264 return (0);
265 else if (ioflag & IO_NDELAY)
266 return (EWOULDBLOCK);
267
268 error = tty_timedwait(tp, &tp->t_inwait, hz);
269 if (error)
270 return (error == EWOULDBLOCK ? 0 : error);
271 }
272
273 return (0);
274 }
275
276 static int
277 ttydisc_read_raw_interbyte_timer(struct tty *tp, struct uio *uio, int ioflag)
278 {
279 size_t vmin = tp->t_termios.c_cc[VMIN];
280 ssize_t oresid = uio->uio_resid;
281 int error;
282
283 MPASS(tp->t_termios.c_cc[VMIN] != 0);
284 MPASS(tp->t_termios.c_cc[VTIME] != 0);
285
286 /*
287 * When using the interbyte timer, the timer should be started
288 * after the first byte has been received. We just call into the
289 * generic read timer code after we've received the first byte.
290 */
291
292 for (;;) {
293 error = tty_wait_background(tp, curthread, SIGTTIN);
294 if (error)
295 return (error);
296
297 error = ttyinq_read_uio(&tp->t_inq, tp, uio,
298 uio->uio_resid, 0);
299 if (error)
300 return (error);
301 if (uio->uio_resid == 0 || (oresid - uio->uio_resid) >= vmin)
302 return (0);
303
304 /*
305 * Not enough data, but we did receive some, which means
306 * we'll now start using the interbyte timer.
307 */
308 if (oresid != uio->uio_resid)
309 break;
310
311 /* We have to wait for more. */
312 if (tp->t_flags & TF_ZOMBIE)
313 return (0);
314 else if (ioflag & IO_NDELAY)
315 return (EWOULDBLOCK);
316
317 error = tty_wait(tp, &tp->t_inwait);
318 if (error)
319 return (error);
320 }
321
322 return ttydisc_read_raw_read_timer(tp, uio, ioflag, oresid);
323 }
324
325 int
326 ttydisc_read(struct tty *tp, struct uio *uio, int ioflag)
327 {
328 int error;
329
330 tty_lock_assert(tp, MA_OWNED);
331
332 if (uio->uio_resid == 0)
333 return (0);
334
335 if (CMP_FLAG(l, ICANON))
336 error = ttydisc_read_canonical(tp, uio, ioflag);
337 else if (tp->t_termios.c_cc[VTIME] == 0)
338 error = ttydisc_read_raw_no_timer(tp, uio, ioflag);
339 else if (tp->t_termios.c_cc[VMIN] == 0)
340 error = ttydisc_read_raw_read_timer(tp, uio, ioflag,
341 uio->uio_resid);
342 else
343 error = ttydisc_read_raw_interbyte_timer(tp, uio, ioflag);
344
345 if (ttyinq_bytesleft(&tp->t_inq) >= tp->t_inlow ||
346 ttyinq_bytescanonicalized(&tp->t_inq) == 0) {
347 /* Unset the input watermark when we've got enough space. */
348 tty_hiwat_in_unblock(tp);
349 }
350
351 return (error);
352 }
353
354 static __inline unsigned int
355 ttydisc_findchar(const char *obstart, unsigned int oblen)
356 {
357 const char *c = obstart;
358
359 while (oblen--) {
360 if (CTL_VALID(*c))
361 break;
362 c++;
363 }
364
365 return (c - obstart);
366 }
367
368 static int
369 ttydisc_write_oproc(struct tty *tp, char c)
370 {
371 unsigned int scnt, error;
372
373 MPASS(CMP_FLAG(o, OPOST));
374 MPASS(CTL_VALID(c));
375
376 #define PRINT_NORMAL() ttyoutq_write_nofrag(&tp->t_outq, &c, 1)
377 switch (c) {
378 case CEOF:
379 /* End-of-text dropping. */
380 if (CMP_FLAG(o, ONOEOT))
381 return (0);
382 return PRINT_NORMAL();
383
384 case CERASE2:
385 /* Handle backspace to fix tab expansion. */
386 if (PRINT_NORMAL() != 0)
387 return (-1);
388 if (tp->t_column > 0)
389 tp->t_column--;
390 return (0);
391
392 case CTAB:
393 /* Tab expansion. */
394 scnt = 8 - (tp->t_column & 7);
395 if (CMP_FLAG(o, TAB3)) {
396 error = ttyoutq_write_nofrag(&tp->t_outq,
397 " ", scnt);
398 } else {
399 error = PRINT_NORMAL();
400 }
401 if (error)
402 return (-1);
403
404 tp->t_column += scnt;
405 MPASS((tp->t_column % 8) == 0);
406 return (0);
407
408 case CNL:
409 /* Newline conversion. */
410 if (CMP_FLAG(o, ONLCR)) {
411 /* Convert \n to \r\n. */
412 error = ttyoutq_write_nofrag(&tp->t_outq, "\r\n", 2);
413 } else {
414 error = PRINT_NORMAL();
415 }
416 if (error)
417 return (-1);
418
419 if (CMP_FLAG(o, ONLCR|ONLRET)) {
420 tp->t_column = tp->t_writepos = 0;
421 ttyinq_reprintpos_set(&tp->t_inq);
422 }
423 return (0);
424
425 case CCR:
426 /* Carriage return to newline conversion. */
427 if (CMP_FLAG(o, OCRNL))
428 c = CNL;
429 /* Omit carriage returns on column 0. */
430 if (CMP_FLAG(o, ONOCR) && tp->t_column == 0)
431 return (0);
432 if (PRINT_NORMAL() != 0)
433 return (-1);
434
435 tp->t_column = tp->t_writepos = 0;
436 ttyinq_reprintpos_set(&tp->t_inq);
437 return (0);
438 }
439
440 /*
441 * Invisible control character. Print it, but don't
442 * increase the column count.
443 */
444 return PRINT_NORMAL();
445 #undef PRINT_NORMAL
446 }
447
448 /*
449 * Just like the old TTY implementation, we need to copy data in chunks
450 * into a temporary buffer. One of the reasons why we need to do this,
451 * is because output processing (only TAB3 though) may allow the buffer
452 * to grow eight times.
453 */
454 int
455 ttydisc_write(struct tty *tp, struct uio *uio, int ioflag)
456 {
457 char ob[TTY_STACKBUF];
458 char *obstart;
459 int error = 0;
460 unsigned int oblen = 0;
461
462 tty_lock_assert(tp, MA_OWNED);
463
464 if (tp->t_flags & TF_ZOMBIE)
465 return (EIO);
466
467 /*
468 * We don't need to check whether the process is the foreground
469 * process group or if we have a carrier. This is already done
470 * in ttydev_write().
471 */
472
473 while (uio->uio_resid > 0) {
474 unsigned int nlen;
475
476 MPASS(oblen == 0);
477
478 /* Step 1: read data. */
479 obstart = ob;
480 nlen = MIN(uio->uio_resid, sizeof ob);
481 tty_unlock(tp);
482 error = uiomove(ob, nlen, uio);
483 tty_lock(tp);
484 if (error != 0)
485 break;
486 oblen = nlen;
487
488 if (tty_gone(tp)) {
489 error = ENXIO;
490 break;
491 }
492
493 MPASS(oblen > 0);
494
495 /* Step 2: process data. */
496 do {
497 unsigned int plen, wlen;
498
499 /* Search for special characters for post processing. */
500 if (CMP_FLAG(o, OPOST)) {
501 plen = ttydisc_findchar(obstart, oblen);
502 } else {
503 plen = oblen;
504 }
505
506 if (plen == 0) {
507 /*
508 * We're going to process a character
509 * that needs processing
510 */
511 if (ttydisc_write_oproc(tp, *obstart) == 0) {
512 obstart++;
513 oblen--;
514
515 tp->t_writepos = tp->t_column;
516 ttyinq_reprintpos_set(&tp->t_inq);
517 continue;
518 }
519 } else {
520 /* We're going to write regular data. */
521 wlen = ttyoutq_write(&tp->t_outq, obstart, plen);
522 obstart += wlen;
523 oblen -= wlen;
524 tp->t_column += wlen;
525
526 tp->t_writepos = tp->t_column;
527 ttyinq_reprintpos_set(&tp->t_inq);
528
529 if (wlen == plen)
530 continue;
531 }
532
533 /* Watermark reached. Try to sleep. */
534 tp->t_flags |= TF_HIWAT_OUT;
535
536 if (ioflag & IO_NDELAY) {
537 error = EWOULDBLOCK;
538 goto done;
539 }
540
541 /*
542 * The driver may write back the data
543 * synchronously. Be sure to check the high
544 * water mark before going to sleep.
545 */
546 ttydevsw_outwakeup(tp);
547 if ((tp->t_flags & TF_HIWAT_OUT) == 0)
548 continue;
549
550 error = tty_wait(tp, &tp->t_outwait);
551 if (error)
552 goto done;
553
554 if (tp->t_flags & TF_ZOMBIE) {
555 error = EIO;
556 goto done;
557 }
558 } while (oblen > 0);
559 }
560
561 done:
562 if (!tty_gone(tp))
563 ttydevsw_outwakeup(tp);
564
565 /*
566 * Add the amount of bytes that we didn't process back to the
567 * uio counters. We need to do this to make sure write() doesn't
568 * count the bytes we didn't store in the queue.
569 */
570 uio->uio_resid += oblen;
571 return (error);
572 }
573
574 void
575 ttydisc_optimize(struct tty *tp)
576 {
577 tty_lock_assert(tp, MA_OWNED);
578
579 if (ttyhook_hashook(tp, rint_bypass)) {
580 tp->t_flags |= TF_BYPASS;
581 } else if (ttyhook_hashook(tp, rint)) {
582 tp->t_flags &= ~TF_BYPASS;
583 } else if (!CMP_FLAG(i, ICRNL|IGNCR|IMAXBEL|INLCR|ISTRIP|IXON) &&
584 (!CMP_FLAG(i, BRKINT) || CMP_FLAG(i, IGNBRK)) &&
585 (!CMP_FLAG(i, PARMRK) ||
586 CMP_FLAG(i, IGNPAR|IGNBRK) == (IGNPAR|IGNBRK)) &&
587 !CMP_FLAG(l, ECHO|ICANON|IEXTEN|ISIG|PENDIN)) {
588 tp->t_flags |= TF_BYPASS;
589 } else {
590 tp->t_flags &= ~TF_BYPASS;
591 }
592 }
593
594 void
595 ttydisc_modem(struct tty *tp, int open)
596 {
597
598 tty_lock_assert(tp, MA_OWNED);
599
600 if (open)
601 cv_broadcast(&tp->t_dcdwait);
602
603 /*
604 * Ignore modem status lines when CLOCAL is turned on, but don't
605 * enter the zombie state when the TTY isn't opened, because
606 * that would cause the TTY to be in zombie state after being
607 * opened.
608 */
609 if (!tty_opened(tp) || CMP_FLAG(c, CLOCAL))
610 return;
611
612 if (open == 0) {
613 /*
614 * Lost carrier.
615 */
616 tp->t_flags |= TF_ZOMBIE;
617
618 tty_signal_sessleader(tp, SIGHUP);
619 tty_flush(tp, FREAD|FWRITE);
620 } else {
621 /*
622 * Carrier is back again.
623 */
624
625 /* XXX: what should we do here? */
626 }
627 }
628
629 static int
630 ttydisc_echo_force(struct tty *tp, char c, int quote)
631 {
632
633 if (CMP_FLAG(o, OPOST) && CTL_ECHO(c, quote)) {
634 /*
635 * Only perform postprocessing when OPOST is turned on
636 * and the character is an unquoted BS/TB/NL/CR.
637 */
638 return ttydisc_write_oproc(tp, c);
639 } else if (CMP_FLAG(l, ECHOCTL) && CTL_PRINT(c, quote)) {
640 /*
641 * Only use ^X notation when ECHOCTL is turned on and
642 * we've got an quoted control character.
643 *
644 * Print backspaces when echoing an end-of-file.
645 */
646 char ob[4] = "^?\b\b";
647
648 /* Print ^X notation. */
649 if (c != 0x7f)
650 ob[1] = c + 'A' - 1;
651
652 if (!quote && CMP_CC(VEOF, c)) {
653 return ttyoutq_write_nofrag(&tp->t_outq, ob, 4);
654 } else {
655 tp->t_column += 2;
656 return ttyoutq_write_nofrag(&tp->t_outq, ob, 2);
657 }
658 } else {
659 /* Can just be printed. */
660 tp->t_column++;
661 return ttyoutq_write_nofrag(&tp->t_outq, &c, 1);
662 }
663 }
664
665 static int
666 ttydisc_echo(struct tty *tp, char c, int quote)
667 {
668
669 /*
670 * Only echo characters when ECHO is turned on, or ECHONL when
671 * the character is an unquoted newline.
672 */
673 if (!CMP_FLAG(l, ECHO) &&
674 (!CMP_FLAG(l, ECHONL) || c != CNL || quote))
675 return (0);
676
677 return ttydisc_echo_force(tp, c, quote);
678 }
679
680 static void
681 ttydisc_reprint_char(void *d, char c, int quote)
682 {
683 struct tty *tp = d;
684
685 ttydisc_echo(tp, c, quote);
686 }
687
688 static void
689 ttydisc_reprint(struct tty *tp)
690 {
691 cc_t c;
692
693 /* Print ^R\n, followed by the line. */
694 c = tp->t_termios.c_cc[VREPRINT];
695 if (c != _POSIX_VDISABLE)
696 ttydisc_echo(tp, c, 0);
697 ttydisc_echo(tp, CNL, 0);
698 ttyinq_reprintpos_reset(&tp->t_inq);
699
700 ttyinq_line_iterate_from_linestart(&tp->t_inq, ttydisc_reprint_char, tp);
701 }
702
703 struct ttydisc_recalc_length {
704 struct tty *tp;
705 unsigned int curlen;
706 };
707
708 static void
709 ttydisc_recalc_charlength(void *d, char c, int quote)
710 {
711 struct ttydisc_recalc_length *data = d;
712 struct tty *tp = data->tp;
713
714 if (CTL_PRINT(c, quote)) {
715 if (CMP_FLAG(l, ECHOCTL))
716 data->curlen += 2;
717 } else if (c == CTAB) {
718 data->curlen += 8 - (data->curlen & 7);
719 } else {
720 data->curlen++;
721 }
722 }
723
724 static unsigned int
725 ttydisc_recalc_linelength(struct tty *tp)
726 {
727 struct ttydisc_recalc_length data = { tp, tp->t_writepos };
728
729 ttyinq_line_iterate_from_reprintpos(&tp->t_inq,
730 ttydisc_recalc_charlength, &data);
731 return (data.curlen);
732 }
733
734 static int
735 ttydisc_rubchar(struct tty *tp)
736 {
737 char c;
738 int quote;
739 unsigned int prevpos, tablen;
740
741 if (ttyinq_peekchar(&tp->t_inq, &c, "e) != 0)
742 return (-1);
743 ttyinq_unputchar(&tp->t_inq);
744
745 if (CMP_FLAG(l, ECHO)) {
746 /*
747 * Remove the character from the screen. This is even
748 * safe for characters that span multiple characters
749 * (tabs, quoted, etc).
750 */
751 if (tp->t_writepos >= tp->t_column) {
752 /* Retype the sentence. */
753 ttydisc_reprint(tp);
754 } else if (CMP_FLAG(l, ECHOE)) {
755 if (CTL_PRINT(c, quote)) {
756 /* Remove ^X formatted chars. */
757 if (CMP_FLAG(l, ECHOCTL)) {
758 tp->t_column -= 2;
759 ttyoutq_write_nofrag(&tp->t_outq,
760 "\b\b \b\b", 6);
761 }
762 } else if (c == ' ') {
763 /* Space character needs no rubbing. */
764 tp->t_column -= 1;
765 ttyoutq_write_nofrag(&tp->t_outq, "\b", 1);
766 } else if (c == CTAB) {
767 /*
768 * Making backspace work with tabs is
769 * quite hard. Recalculate the length of
770 * this character and remove it.
771 *
772 * Because terminal settings could be
773 * changed while the line is being
774 * inserted, the calculations don't have
775 * to be correct. Make sure we keep the
776 * tab length within proper bounds.
777 */
778 prevpos = ttydisc_recalc_linelength(tp);
779 if (prevpos >= tp->t_column)
780 tablen = 1;
781 else
782 tablen = tp->t_column - prevpos;
783 if (tablen > 8)
784 tablen = 8;
785
786 tp->t_column = prevpos;
787 ttyoutq_write_nofrag(&tp->t_outq,
788 "\b\b\b\b\b\b\b\b", tablen);
789 return (0);
790 } else {
791 /*
792 * Remove a regular character by
793 * punching a space over it.
794 */
795 tp->t_column -= 1;
796 ttyoutq_write_nofrag(&tp->t_outq, "\b \b", 3);
797 }
798 } else {
799 /* Don't print spaces. */
800 ttydisc_echo(tp, tp->t_termios.c_cc[VERASE], 0);
801 }
802 }
803
804 return (0);
805 }
806
807 static void
808 ttydisc_rubword(struct tty *tp)
809 {
810 char c;
811 int quote, alnum;
812
813 /* Strip whitespace first. */
814 for (;;) {
815 if (ttyinq_peekchar(&tp->t_inq, &c, "e) != 0)
816 return;
817 if (!CTL_WHITE(c))
818 break;
819 ttydisc_rubchar(tp);
820 }
821
822 /*
823 * Record whether the last character from the previous iteration
824 * was alphanumeric or not. We need this to implement ALTWERASE.
825 */
826 alnum = CTL_ALNUM(c);
827 for (;;) {
828 ttydisc_rubchar(tp);
829
830 if (ttyinq_peekchar(&tp->t_inq, &c, "e) != 0)
831 return;
832 if (CTL_WHITE(c))
833 return;
834 if (CMP_FLAG(l, ALTWERASE) && CTL_ALNUM(c) != alnum)
835 return;
836 }
837 }
838
839 int
840 ttydisc_rint(struct tty *tp, char c, int flags)
841 {
842 int signal, quote = 0;
843 char ob[3] = { 0xff, 0x00 };
844 size_t ol;
845
846 tty_lock_assert(tp, MA_OWNED);
847
848 atomic_add_long(&tty_nin, 1);
849
850 if (ttyhook_hashook(tp, rint))
851 return ttyhook_rint(tp, c, flags);
852
853 if (tp->t_flags & TF_BYPASS)
854 goto processed;
855
856 if (flags) {
857 if (flags & TRE_BREAK) {
858 if (CMP_FLAG(i, IGNBRK)) {
859 /* Ignore break characters. */
860 return (0);
861 } else if (CMP_FLAG(i, BRKINT)) {
862 /* Generate SIGINT on break. */
863 tty_flush(tp, FREAD|FWRITE);
864 tty_signal_pgrp(tp, SIGINT);
865 return (0);
866 } else {
867 /* Just print it. */
868 goto parmrk;
869 }
870 } else if (flags & TRE_FRAMING ||
871 (flags & TRE_PARITY && CMP_FLAG(i, INPCK))) {
872 if (CMP_FLAG(i, IGNPAR)) {
873 /* Ignore bad characters. */
874 return (0);
875 } else {
876 /* Just print it. */
877 goto parmrk;
878 }
879 }
880 }
881
882 /* Allow any character to perform a wakeup. */
883 if (CMP_FLAG(i, IXANY))
884 tp->t_flags &= ~TF_STOPPED;
885
886 /* Remove the top bit. */
887 if (CMP_FLAG(i, ISTRIP))
888 c &= ~0x80;
889
890 /* Skip input processing when we want to print it literally. */
891 if (tp->t_flags & TF_LITERAL) {
892 tp->t_flags &= ~TF_LITERAL;
893 quote = 1;
894 goto processed;
895 }
896
897 /* Special control characters that are implementation dependent. */
898 if (CMP_FLAG(l, IEXTEN)) {
899 /* Accept the next character as literal. */
900 if (CMP_CC(VLNEXT, c)) {
901 if (CMP_FLAG(l, ECHO)) {
902 if (CMP_FLAG(l, ECHOE))
903 ttyoutq_write_nofrag(&tp->t_outq, "^\b", 2);
904 else
905 ttydisc_echo(tp, c, 0);
906 }
907 tp->t_flags |= TF_LITERAL;
908 return (0);
909 }
910 }
911
912 /*
913 * Handle signal processing.
914 */
915 if (CMP_FLAG(l, ISIG)) {
916 if (CMP_FLAG(l, ICANON|IEXTEN) == (ICANON|IEXTEN)) {
917 if (CMP_CC(VSTATUS, c)) {
918 tty_signal_pgrp(tp, SIGINFO);
919 return (0);
920 }
921 }
922
923 /*
924 * When compared to the old implementation, this
925 * implementation also flushes the output queue. POSIX
926 * is really brief about this, but does makes us assume
927 * we have to do so.
928 */
929 signal = 0;
930 if (CMP_CC(VINTR, c)) {
931 signal = SIGINT;
932 } else if (CMP_CC(VQUIT, c)) {
933 signal = SIGQUIT;
934 } else if (CMP_CC(VSUSP, c)) {
935 signal = SIGTSTP;
936 }
937
938 if (signal != 0) {
939 /*
940 * Echo the character before signalling the
941 * processes.
942 */
943 if (!CMP_FLAG(l, NOFLSH))
944 tty_flush(tp, FREAD|FWRITE);
945 ttydisc_echo(tp, c, 0);
946 tty_signal_pgrp(tp, signal);
947 return (0);
948 }
949 }
950
951 /*
952 * Handle start/stop characters.
953 */
954 if (CMP_FLAG(i, IXON)) {
955 if (CMP_CC(VSTOP, c)) {
956 /* Stop it if we aren't stopped yet. */
957 if ((tp->t_flags & TF_STOPPED) == 0) {
958 tp->t_flags |= TF_STOPPED;
959 return (0);
960 }
961 /*
962 * Fallthrough:
963 * When VSTART == VSTOP, we should make this key
964 * toggle it.
965 */
966 if (!CMP_CC(VSTART, c))
967 return (0);
968 }
969 if (CMP_CC(VSTART, c)) {
970 tp->t_flags &= ~TF_STOPPED;
971 return (0);
972 }
973 }
974
975 /* Conversion of CR and NL. */
976 switch (c) {
977 case CCR:
978 if (CMP_FLAG(i, IGNCR))
979 return (0);
980 if (CMP_FLAG(i, ICRNL))
981 c = CNL;
982 break;
983 case CNL:
984 if (CMP_FLAG(i, INLCR))
985 c = CCR;
986 break;
987 }
988
989 /* Canonical line editing. */
990 if (CMP_FLAG(l, ICANON)) {
991 if (CMP_CC(VERASE, c) || CMP_CC(VERASE2, c)) {
992 ttydisc_rubchar(tp);
993 return (0);
994 } else if (CMP_CC(VKILL, c)) {
995 while (ttydisc_rubchar(tp) == 0);
996 return (0);
997 } else if (CMP_FLAG(l, IEXTEN)) {
998 if (CMP_CC(VWERASE, c)) {
999 ttydisc_rubword(tp);
1000 return (0);
1001 } else if (CMP_CC(VREPRINT, c)) {
1002 ttydisc_reprint(tp);
1003 return (0);
1004 }
1005 }
1006 }
1007
1008 processed:
1009 if (CMP_FLAG(i, PARMRK) && (unsigned char)c == 0xff) {
1010 /* Print 0xff 0xff. */
1011 ob[1] = 0xff;
1012 ol = 2;
1013 quote = 1;
1014 } else {
1015 ob[0] = c;
1016 ol = 1;
1017 }
1018
1019 goto print;
1020
1021 parmrk:
1022 if (CMP_FLAG(i, PARMRK)) {
1023 /* Prepend 0xff 0x00 0x.. */
1024 ob[2] = c;
1025 ol = 3;
1026 quote = 1;
1027 } else {
1028 ob[0] = c;
1029 ol = 1;
1030 }
1031
1032 print:
1033 /* See if we can store this on the input queue. */
1034 if (ttyinq_write_nofrag(&tp->t_inq, ob, ol, quote) != 0) {
1035 if (CMP_FLAG(i, IMAXBEL))
1036 ttyoutq_write_nofrag(&tp->t_outq, "\a", 1);
1037
1038 /*
1039 * Prevent a deadlock here. It may be possible that a
1040 * user has entered so much data, there is no data
1041 * available to read(), but the buffers are full anyway.
1042 *
1043 * Only enter the high watermark if the device driver
1044 * can actually transmit something.
1045 */
1046 if (ttyinq_bytescanonicalized(&tp->t_inq) == 0)
1047 return (0);
1048
1049 tty_hiwat_in_block(tp);
1050 return (-1);
1051 }
1052
1053 /*
1054 * In raw mode, we canonicalize after receiving a single
1055 * character. Otherwise, we canonicalize when we receive a
1056 * newline, VEOL or VEOF, but only when it isn't quoted.
1057 */
1058 if (!CMP_FLAG(l, ICANON) ||
1059 (!quote && (c == CNL || CMP_CC(VEOL, c) || CMP_CC(VEOF, c)))) {
1060 ttyinq_canonicalize(&tp->t_inq);
1061 }
1062
1063 ttydisc_echo(tp, c, quote);
1064
1065 return (0);
1066 }
1067
1068 size_t
1069 ttydisc_rint_simple(struct tty *tp, const void *buf, size_t len)
1070 {
1071 const char *cbuf;
1072
1073 if (ttydisc_can_bypass(tp))
1074 return (ttydisc_rint_bypass(tp, buf, len));
1075
1076 for (cbuf = buf; len-- > 0; cbuf++) {
1077 if (ttydisc_rint(tp, *cbuf, 0) != 0)
1078 break;
1079 }
1080
1081 return (cbuf - (const char *)buf);
1082 }
1083
1084 size_t
1085 ttydisc_rint_bypass(struct tty *tp, const void *buf, size_t len)
1086 {
1087 size_t ret;
1088
1089 tty_lock_assert(tp, MA_OWNED);
1090
1091 MPASS(tp->t_flags & TF_BYPASS);
1092
1093 atomic_add_long(&tty_nin, len);
1094
1095 if (ttyhook_hashook(tp, rint_bypass))
1096 return ttyhook_rint_bypass(tp, buf, len);
1097
1098 ret = ttyinq_write(&tp->t_inq, buf, len, 0);
1099 ttyinq_canonicalize(&tp->t_inq);
1100 if (ret < len)
1101 tty_hiwat_in_block(tp);
1102
1103 return (ret);
1104 }
1105
1106 void
1107 ttydisc_rint_done(struct tty *tp)
1108 {
1109
1110 tty_lock_assert(tp, MA_OWNED);
1111
1112 if (ttyhook_hashook(tp, rint_done))
1113 ttyhook_rint_done(tp);
1114
1115 /* Wake up readers. */
1116 tty_wakeup(tp, FREAD);
1117 /* Wake up driver for echo. */
1118 ttydevsw_outwakeup(tp);
1119 }
1120
1121 size_t
1122 ttydisc_rint_poll(struct tty *tp)
1123 {
1124 size_t l;
1125
1126 tty_lock_assert(tp, MA_OWNED);
1127
1128 if (ttyhook_hashook(tp, rint_poll))
1129 return ttyhook_rint_poll(tp);
1130
1131 /*
1132 * XXX: Still allow character input when there's no space in the
1133 * buffers, but we haven't entered the high watermark. This is
1134 * to allow backspace characters to be inserted when in
1135 * canonical mode.
1136 */
1137 l = ttyinq_bytesleft(&tp->t_inq);
1138 if (l == 0 && (tp->t_flags & TF_HIWAT_IN) == 0)
1139 return (1);
1140
1141 return (l);
1142 }
1143
1144 static void
1145 ttydisc_wakeup_watermark(struct tty *tp)
1146 {
1147 size_t c;
1148
1149 c = ttyoutq_bytesleft(&tp->t_outq);
1150 if (tp->t_flags & TF_HIWAT_OUT) {
1151 /* Only allow us to run when we're below the watermark. */
1152 if (c < tp->t_outlow)
1153 return;
1154
1155 /* Reset the watermark. */
1156 tp->t_flags &= ~TF_HIWAT_OUT;
1157 } else {
1158 /* Only run when we have data at all. */
1159 if (c == 0)
1160 return;
1161 }
1162 tty_wakeup(tp, FWRITE);
1163 }
1164
1165 size_t
1166 ttydisc_getc(struct tty *tp, void *buf, size_t len)
1167 {
1168
1169 tty_lock_assert(tp, MA_OWNED);
1170
1171 if (tp->t_flags & TF_STOPPED)
1172 return (0);
1173
1174 if (ttyhook_hashook(tp, getc_inject))
1175 return ttyhook_getc_inject(tp, buf, len);
1176
1177 len = ttyoutq_read(&tp->t_outq, buf, len);
1178
1179 if (ttyhook_hashook(tp, getc_capture))
1180 ttyhook_getc_capture(tp, buf, len);
1181
1182 ttydisc_wakeup_watermark(tp);
1183 atomic_add_long(&tty_nout, len);
1184
1185 return (len);
1186 }
1187
1188 int
1189 ttydisc_getc_uio(struct tty *tp, struct uio *uio)
1190 {
1191 int error = 0;
1192 ssize_t obytes = uio->uio_resid;
1193 size_t len;
1194 char buf[TTY_STACKBUF];
1195
1196 tty_lock_assert(tp, MA_OWNED);
1197
1198 if (tp->t_flags & TF_STOPPED)
1199 return (0);
1200
1201 /*
1202 * When a TTY hook is attached, we cannot perform unbuffered
1203 * copying to userspace. Just call ttydisc_getc() and
1204 * temporarily store data in a shadow buffer.
1205 */
1206 if (ttyhook_hashook(tp, getc_capture) ||
1207 ttyhook_hashook(tp, getc_inject)) {
1208 while (uio->uio_resid > 0) {
1209 /* Read to shadow buffer. */
1210 len = ttydisc_getc(tp, buf,
1211 MIN(uio->uio_resid, sizeof buf));
1212 if (len == 0)
1213 break;
1214
1215 /* Copy to userspace. */
1216 tty_unlock(tp);
1217 error = uiomove(buf, len, uio);
1218 tty_lock(tp);
1219
1220 if (error != 0)
1221 break;
1222 }
1223 } else {
1224 error = ttyoutq_read_uio(&tp->t_outq, tp, uio);
1225
1226 ttydisc_wakeup_watermark(tp);
1227 atomic_add_long(&tty_nout, obytes - uio->uio_resid);
1228 }
1229
1230 return (error);
1231 }
1232
1233 size_t
1234 ttydisc_getc_poll(struct tty *tp)
1235 {
1236
1237 tty_lock_assert(tp, MA_OWNED);
1238
1239 if (tp->t_flags & TF_STOPPED)
1240 return (0);
1241
1242 if (ttyhook_hashook(tp, getc_poll))
1243 return ttyhook_getc_poll(tp);
1244
1245 return ttyoutq_bytesused(&tp->t_outq);
1246 }
1247
1248 /*
1249 * XXX: not really related to the TTYDISC, but we'd better put
1250 * tty_putchar() here, because we need to perform proper output
1251 * processing.
1252 */
1253
1254 int
1255 tty_putchar(struct tty *tp, char c)
1256 {
1257 tty_lock_assert(tp, MA_OWNED);
1258
1259 if (tty_gone(tp))
1260 return (-1);
1261
1262 ttydisc_echo_force(tp, c, 0);
1263 tp->t_writepos = tp->t_column;
1264 ttyinq_reprintpos_set(&tp->t_inq);
1265
1266 ttydevsw_outwakeup(tp);
1267 return (0);
1268 }
Cache object: a42f6222aa525dd2d890836acd164efc
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