xref: /netbsd-src/sys/kern/tty_subr.c (revision 81b108b45f75f89f1e3ffad9fb6f074e771c0935)
1 /*	$NetBSD: tty_subr.c,v 1.13 1996/02/09 19:00:43 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1993, 1994 Theo de Raadt
5  * All rights reserved.
6  *
7  * Per Lindqvist <pgd@compuram.bbt.se> supplied an almost fully working
8  * set of true clist functions that this is very loosely based on.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by Theo de Raadt.
21  * 4. The name of the author may not be used to endorse or promote products
22  *    derived from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/buf.h>
39 #include <sys/ioctl.h>
40 #include <sys/tty.h>
41 #ifdef REAL_CLISTS
42 #include <sys/clist.h>
43 #endif
44 #include <sys/malloc.h>
45 
46 /*
47  * At compile time, choose:
48  * There are two ways the TTY_QUOTE bit can be stored. If QBITS is
49  * defined we allocate an array of bits -- 1/8th as much memory but
50  * setbit(), clrbit(), and isset() take more cpu. If QBITS is
51  * undefined, we just use an array of bytes.
52  *
53  * If TTY_QUOTE functionality isn't required by a line discipline,
54  * it can free c_cq and set it to NULL. This speeds things up,
55  * and also does not use any extra memory. This is useful for (say)
56  * a SLIP line discipline that wants a 32K ring buffer for data
57  * but doesn't need quoting.
58  */
59 #define QBITS
60 
61 #ifdef QBITS
62 #define QMEM(n)		((((n)-1)/NBBY)+1)
63 #else
64 #define QMEM(n)		(n)
65 #endif
66 
67 void	cinit __P((void));
68 int	ndqb __P((struct clist *, int));
69 int	putc __P((int, struct clist *));
70 #ifdef QBITS
71 void	clrbits __P((u_char *, int, int));
72 #endif
73 int	b_to_q __P((u_char *, int, struct clist *));
74 u_char *firstc __P((struct clist *, int *));
75 
76 /*
77  * Initialize clists.
78  */
79 void
80 cinit()
81 {
82 }
83 
84 /*
85  * Initialize a particular clist. Ok, they are really ring buffers,
86  * of the specified length, with/without quoting support.
87  */
88 int
89 clalloc(clp, size, quot)
90 	struct clist *clp;
91 	int size;
92 	int quot;
93 {
94 
95 	MALLOC(clp->c_cs, u_char *, size, M_TTYS, M_WAITOK);
96 	if (!clp->c_cs)
97 		return (-1);
98 	bzero(clp->c_cs, size);
99 
100 	if(quot) {
101 		MALLOC(clp->c_cq, u_char *, QMEM(size), M_TTYS, M_WAITOK);
102 		if (!clp->c_cq) {
103 			FREE(clp->c_cs, M_TTYS);
104 			return (-1);
105 		}
106 		bzero(clp->c_cs, QMEM(size));
107 	} else
108 		clp->c_cq = (u_char *)0;
109 
110 	clp->c_cf = clp->c_cl = (u_char *)0;
111 	clp->c_ce = clp->c_cs + size;
112 	clp->c_cn = size;
113 	clp->c_cc = 0;
114 	return (0);
115 }
116 
117 void
118 clfree(clp)
119 	struct clist *clp;
120 {
121 	if(clp->c_cs)
122 		FREE(clp->c_cs, M_TTYS);
123 	if(clp->c_cq)
124 		FREE(clp->c_cq, M_TTYS);
125 	clp->c_cs = clp->c_cq = (u_char *)0;
126 }
127 
128 
129 /*
130  * Get a character from a clist.
131  */
132 int
133 getc(clp)
134 	struct clist *clp;
135 {
136 	register int c = -1;
137 	int s;
138 
139 	s = spltty();
140 	if (clp->c_cc == 0)
141 		goto out;
142 
143 	c = *clp->c_cf & 0xff;
144 	if (clp->c_cq) {
145 #ifdef QBITS
146 		if (isset(clp->c_cq, clp->c_cf - clp->c_cs) )
147 			c |= TTY_QUOTE;
148 #else
149 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
150 			c |= TTY_QUOTE;
151 #endif
152 	}
153 	if (++clp->c_cf == clp->c_ce)
154 		clp->c_cf = clp->c_cs;
155 	if (--clp->c_cc == 0)
156 		clp->c_cf = clp->c_cl = (u_char *)0;
157 out:
158 	splx(s);
159 	return c;
160 }
161 
162 /*
163  * Copy clist to buffer.
164  * Return number of bytes moved.
165  */
166 int
167 q_to_b(clp, cp, count)
168 	struct clist *clp;
169 	u_char *cp;
170 	int count;
171 {
172 	register int cc;
173 	u_char *p = cp;
174 	int s;
175 
176 	s = spltty();
177 	/* optimize this while loop */
178 	while (count > 0 && clp->c_cc > 0) {
179 		cc = clp->c_cl - clp->c_cf;
180 		if (clp->c_cf >= clp->c_cl)
181 			cc = clp->c_ce - clp->c_cf;
182 		if (cc > count)
183 			cc = count;
184 		bcopy(clp->c_cf, p, cc);
185 		count -= cc;
186 		p += cc;
187 		clp->c_cc -= cc;
188 		clp->c_cf += cc;
189 		if (clp->c_cf == clp->c_ce)
190 			clp->c_cf = clp->c_cs;
191 	}
192 	if (clp->c_cc == 0)
193 		clp->c_cf = clp->c_cl = (u_char *)0;
194 	splx(s);
195 	return p - cp;
196 }
197 
198 /*
199  * Return count of contiguous characters in clist.
200  * Stop counting if flag&character is non-null.
201  */
202 int
203 ndqb(clp, flag)
204 	struct clist *clp;
205 	int flag;
206 {
207 	int count = 0;
208 	register int i;
209 	register int cc;
210 	int s;
211 
212 	s = spltty();
213 	if ((cc = clp->c_cc) == 0)
214 		goto out;
215 
216 	if (flag == 0) {
217 		count = clp->c_cl - clp->c_cf;
218 		if (count <= 0)
219 			count = clp->c_ce - clp->c_cf;
220 		goto out;
221 	}
222 
223 	i = clp->c_cf - clp->c_cs;
224 	if (flag & TTY_QUOTE) {
225 		while (cc-- > 0 && !(clp->c_cs[i++] & (flag & ~TTY_QUOTE) ||
226 		    isset(clp->c_cq, i))) {
227 			count++;
228 			if (i == clp->c_cn)
229 				break;
230 		}
231 	} else {
232 		while (cc-- > 0 && !(clp->c_cs[i++] & flag)) {
233 			count++;
234 			if (i == clp->c_cn)
235 				break;
236 		}
237 	}
238 out:
239 	splx(s);
240 	return count;
241 }
242 
243 /*
244  * Flush count bytes from clist.
245  */
246 void
247 ndflush(clp, count)
248 	struct clist *clp;
249 	int count;
250 {
251 	register int cc;
252 	int s;
253 
254 	s = spltty();
255 	if (count == clp->c_cc) {
256 		clp->c_cc = 0;
257 		clp->c_cf = clp->c_cl = (u_char *)0;
258 		goto out;
259 	}
260 	/* optimize this while loop */
261 	while (count > 0 && clp->c_cc > 0) {
262 		cc = clp->c_cl - clp->c_cf;
263 		if (clp->c_cf >= clp->c_cl)
264 			cc = clp->c_ce - clp->c_cf;
265 		if (cc > count)
266 			cc = count;
267 		count -= cc;
268 		clp->c_cc -= cc;
269 		clp->c_cf += cc;
270 		if (clp->c_cf == clp->c_ce)
271 			clp->c_cf = clp->c_cs;
272 	}
273 	if (clp->c_cc == 0)
274 		clp->c_cf = clp->c_cl = (u_char *)0;
275 out:
276 	splx(s);
277 }
278 
279 /*
280  * Put a character into the output queue.
281  */
282 int
283 putc(c, clp)
284 	int c;
285 	struct clist *clp;
286 {
287 	register int i;
288 	int s;
289 
290 	s = spltty();
291 	if (clp->c_cc == clp->c_cn)
292 		goto out;
293 
294 	if (clp->c_cc == 0) {
295 		if (!clp->c_cs) {
296 #if defined(DIAGNOSTIC) || 1
297 			printf("putc: required clalloc\n");
298 #endif
299 			if(clalloc(clp, 1024, 1)) {
300 out:
301 				splx(s);
302 				return -1;
303 			}
304 		}
305 		clp->c_cf = clp->c_cl = clp->c_cs;
306 	}
307 
308 	*clp->c_cl = c & 0xff;
309 	i = clp->c_cl - clp->c_cs;
310 	if (clp->c_cq) {
311 #ifdef QBITS
312 		if (c & TTY_QUOTE)
313 			setbit(clp->c_cq, i);
314 		else
315 			clrbit(clp->c_cq, i);
316 #else
317 		q = clp->c_cq + i;
318 		*q = (c & TTY_QUOTE) ? 1 : 0;
319 #endif
320 	}
321 	clp->c_cc++;
322 	clp->c_cl++;
323 	if (clp->c_cl == clp->c_ce)
324 		clp->c_cl = clp->c_cs;
325 	splx(s);
326 	return 0;
327 }
328 
329 #ifdef QBITS
330 /*
331  * optimized version of
332  *
333  * for (i = 0; i < len; i++)
334  *	clrbit(cp, off + len);
335  */
336 void
337 clrbits(cp, off, len)
338 	u_char *cp;
339 	int off;
340 	int len;
341 {
342 	int sby, sbi, eby, ebi;
343 	register int i;
344 	u_char mask;
345 
346 	if(len==1) {
347 		clrbit(cp, off);
348 		return;
349 	}
350 
351 	sby = off / NBBY;
352 	sbi = off % NBBY;
353 	eby = (off+len) / NBBY;
354 	ebi = (off+len) % NBBY;
355 	if (sby == eby) {
356 		mask = ((1 << (ebi - sbi)) - 1) << sbi;
357 		cp[sby] &= ~mask;
358 	} else {
359 		mask = (1<<sbi) - 1;
360 		cp[sby++] &= mask;
361 
362 		mask = (1<<ebi) - 1;
363 		cp[eby] &= ~mask;
364 
365 		for (i = sby; i < eby; i++)
366 			cp[i] = 0x00;
367 	}
368 }
369 #endif
370 
371 /*
372  * Copy buffer to clist.
373  * Return number of bytes not transfered.
374  */
375 int
376 b_to_q(cp, count, clp)
377 	u_char *cp;
378 	int count;
379 	struct clist *clp;
380 {
381 	register int cc;
382 	register u_char *p = cp;
383 	int s;
384 
385 	if (count <= 0)
386 		return 0;
387 
388 	s = spltty();
389 	if (clp->c_cc == clp->c_cn)
390 		goto out;
391 
392 	if (clp->c_cc == 0) {
393 		if (!clp->c_cs) {
394 #if defined(DIAGNOSTIC) || 1
395 			printf("b_to_q: required clalloc\n");
396 #endif
397 			if(clalloc(clp, 1024, 1))
398 				goto out;
399 		}
400 		clp->c_cf = clp->c_cl = clp->c_cs;
401 	}
402 
403 	/* optimize this while loop */
404 	while (count > 0 && clp->c_cc < clp->c_cn) {
405 		cc = clp->c_ce - clp->c_cl;
406 		if (clp->c_cf > clp->c_cl)
407 			cc = clp->c_cf - clp->c_cl;
408 		if (cc > count)
409 			cc = count;
410 		bcopy(p, clp->c_cl, cc);
411 		if (clp->c_cq) {
412 #ifdef QBITS
413 			clrbits(clp->c_cq, clp->c_cl - clp->c_cs, cc);
414 #else
415 			bzero(clp->c_cl - clp->c_cs + clp->c_cq, cc);
416 #endif
417 		}
418 		p += cc;
419 		count -= cc;
420 		clp->c_cc += cc;
421 		clp->c_cl += cc;
422 		if (clp->c_cl == clp->c_ce)
423 			clp->c_cl = clp->c_cs;
424 	}
425 out:
426 	splx(s);
427 	return count;
428 }
429 
430 static int cc;
431 
432 /*
433  * Given a non-NULL pointer into the clist return the pointer
434  * to the next character in the list or return NULL if no more chars.
435  *
436  * Callers must not allow getc's to happen between firstc's and getc's
437  * so that the pointer becomes invalid.  Note that interrupts are NOT
438  * masked.
439  */
440 u_char *
441 nextc(clp, cp, c)
442 	struct clist *clp;
443 	register u_char *cp;
444 	int *c;
445 {
446 
447 	if (clp->c_cf == cp) {
448 		/*
449 		 * First time initialization.
450 		 */
451 		cc = clp->c_cc;
452 	}
453 	if (cc == 0 || cp == NULL)
454 		return NULL;
455 	if (--cc == 0)
456 		return NULL;
457 	if (++cp == clp->c_ce)
458 		cp = clp->c_cs;
459 	*c = *cp & 0xff;
460 	if (clp->c_cq) {
461 #ifdef QBITS
462 		if (isset(clp->c_cq, cp - clp->c_cs))
463 			*c |= TTY_QUOTE;
464 #else
465 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
466 			*c |= TTY_QUOTE;
467 #endif
468 	}
469 	return cp;
470 }
471 
472 /*
473  * Given a non-NULL pointer into the clist return the pointer
474  * to the first character in the list or return NULL if no more chars.
475  *
476  * Callers must not allow getc's to happen between firstc's and getc's
477  * so that the pointer becomes invalid.  Note that interrupts are NOT
478  * masked.
479  *
480  * *c is set to the NEXT character
481  */
482 u_char *
483 firstc(clp, c)
484 	struct clist *clp;
485 	int *c;
486 {
487 	register u_char *cp;
488 
489 	cc = clp->c_cc;
490 	if (cc == 0)
491 		return NULL;
492 	cp = clp->c_cf;
493 	*c = *cp & 0xff;
494 	if(clp->c_cq) {
495 #ifdef QBITS
496 		if (isset(clp->c_cq, cp - clp->c_cs))
497 			*c |= TTY_QUOTE;
498 #else
499 		if (*(cp - clp->c_cs + clp->c_cq))
500 			*c |= TTY_QUOTE;
501 #endif
502 	}
503 	return clp->c_cf;
504 }
505 
506 /*
507  * Remove the last character in the clist and return it.
508  */
509 int
510 unputc(clp)
511 	struct clist *clp;
512 {
513 	unsigned int c = -1;
514 	int s;
515 
516 	s = spltty();
517 	if (clp->c_cc == 0)
518 		goto out;
519 
520 	if (clp->c_cl == clp->c_cs)
521 		clp->c_cl = clp->c_ce - 1;
522 	else
523 		--clp->c_cl;
524 	clp->c_cc--;
525 
526 	c = *clp->c_cl & 0xff;
527 	if (clp->c_cq) {
528 #ifdef QBITS
529 		if (isset(clp->c_cq, clp->c_cl - clp->c_cs))
530 			c |= TTY_QUOTE;
531 #else
532 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
533 			c |= TTY_QUOTE;
534 #endif
535 	}
536 	if (clp->c_cc == 0)
537 		clp->c_cf = clp->c_cl = (u_char *)0;
538 out:
539 	splx(s);
540 	return c;
541 }
542 
543 /*
544  * Put the chars in the from queue on the end of the to queue.
545  */
546 void
547 catq(from, to)
548 	struct clist *from, *to;
549 {
550 	int c;
551 
552 	while ((c = getc(from)) != -1)
553 		putc(c, to);
554 }
555