xref: /netbsd-src/sys/kern/tty_subr.c (revision 1f2744e6e4915c9da2a3f980279398c4cf7d5e6d)
1 /*	$NetBSD: tty_subr.c,v 1.11 1994/10/30 21:48:03 cgd 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 
68 /*
69  * Initialize clists.
70  */
71 void
72 cinit()
73 {
74 }
75 
76 /*
77  * Initialize a particular clist. Ok, they are really ring buffers,
78  * of the specified length, with/without quoting support.
79  */
80 int
81 clalloc(clp, size, quot)
82 	struct clist *clp;
83 	int size;
84 	int quot;
85 {
86 
87 	MALLOC(clp->c_cs, u_char *, size, M_TTYS, M_WAITOK);
88 	if (!clp->c_cs)
89 		return (-1);
90 	bzero(clp->c_cs, size);
91 
92 	if(quot) {
93 		MALLOC(clp->c_cq, u_char *, QMEM(size), M_TTYS, M_WAITOK);
94 		if (!clp->c_cq) {
95 			FREE(clp->c_cs, M_TTYS);
96 			return (-1);
97 		}
98 		bzero(clp->c_cs, QMEM(size));
99 	} else
100 		clp->c_cq = (u_char *)0;
101 
102 	clp->c_cf = clp->c_cl = (u_char *)0;
103 	clp->c_ce = clp->c_cs + size;
104 	clp->c_cn = size;
105 	clp->c_cc = 0;
106 	return (0);
107 }
108 
109 void
110 clfree(clp)
111 	struct clist *clp;
112 {
113 	if(clp->c_cs)
114 		FREE(clp->c_cs, M_TTYS);
115 	if(clp->c_cq)
116 		FREE(clp->c_cq, M_TTYS);
117 	clp->c_cs = clp->c_cq = (u_char *)0;
118 }
119 
120 
121 /*
122  * Get a character from a clist.
123  */
124 int
125 getc(clp)
126 	struct clist *clp;
127 {
128 	register int c = -1;
129 	int s;
130 
131 	s = spltty();
132 	if (clp->c_cc == 0)
133 		goto out;
134 
135 	c = *clp->c_cf & 0xff;
136 	if (clp->c_cq) {
137 #ifdef QBITS
138 		if (isset(clp->c_cq, clp->c_cf - clp->c_cs) )
139 			c |= TTY_QUOTE;
140 #else
141 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
142 			c |= TTY_QUOTE;
143 #endif
144 	}
145 	if (++clp->c_cf == clp->c_ce)
146 		clp->c_cf = clp->c_cs;
147 	if (--clp->c_cc == 0)
148 		clp->c_cf = clp->c_cl = (u_char *)0;
149 out:
150 	splx(s);
151 	return c;
152 }
153 
154 /*
155  * Copy clist to buffer.
156  * Return number of bytes moved.
157  */
158 int
159 q_to_b(clp, cp, count)
160 	struct clist *clp;
161 	u_char *cp;
162 	int count;
163 {
164 	register int cc;
165 	u_char *p = cp;
166 	int s;
167 
168 	s = spltty();
169 	/* optimize this while loop */
170 	while (count > 0 && clp->c_cc > 0) {
171 		cc = clp->c_cl - clp->c_cf;
172 		if (clp->c_cf >= clp->c_cl)
173 			cc = clp->c_ce - clp->c_cf;
174 		if (cc > count)
175 			cc = count;
176 		bcopy(clp->c_cf, p, cc);
177 		count -= cc;
178 		p += cc;
179 		clp->c_cc -= cc;
180 		clp->c_cf += cc;
181 		if (clp->c_cf == clp->c_ce)
182 			clp->c_cf = clp->c_cs;
183 	}
184 	if (clp->c_cc == 0)
185 		clp->c_cf = clp->c_cl = (u_char *)0;
186 	splx(s);
187 	return p - cp;
188 }
189 
190 /*
191  * Return count of contiguous characters in clist.
192  * Stop counting if flag&character is non-null.
193  */
194 ndqb(clp, flag)
195 	struct clist *clp;
196 	int flag;
197 {
198 	int count = 0;
199 	register int i;
200 	register int cc;
201 	int s;
202 
203 	s = spltty();
204 	if ((cc = clp->c_cc) == 0)
205 		goto out;
206 
207 	if (flag == 0) {
208 		count = clp->c_cl - clp->c_cf;
209 		if (count <= 0)
210 			count = clp->c_ce - clp->c_cf;
211 		goto out;
212 	}
213 
214 	i = clp->c_cf - clp->c_cs;
215 	if (flag & TTY_QUOTE) {
216 		while (cc-- > 0 && !(clp->c_cs[i++] & (flag & ~TTY_QUOTE) ||
217 		    isset(clp->c_cq, i))) {
218 			count++;
219 			if (i == clp->c_cn)
220 				break;
221 		}
222 	} else {
223 		while (cc-- > 0 && !(clp->c_cs[i++] & flag)) {
224 			count++;
225 			if (i == clp->c_cn)
226 				break;
227 		}
228 	}
229 out:
230 	splx(s);
231 	return count;
232 }
233 
234 /*
235  * Flush count bytes from clist.
236  */
237 void
238 ndflush(clp, count)
239 	struct clist *clp;
240 	int count;
241 {
242 	register int cc;
243 	int s;
244 
245 	s = spltty();
246 	if (count == clp->c_cc) {
247 		clp->c_cc = 0;
248 		clp->c_cf = clp->c_cl = (u_char *)0;
249 		goto out;
250 	}
251 	/* optimize this while loop */
252 	while (count > 0 && clp->c_cc > 0) {
253 		cc = clp->c_cl - clp->c_cf;
254 		if (clp->c_cf >= clp->c_cl)
255 			cc = clp->c_ce - clp->c_cf;
256 		if (cc > count)
257 			cc = count;
258 		count -= cc;
259 		clp->c_cc -= cc;
260 		clp->c_cf += cc;
261 		if (clp->c_cf == clp->c_ce)
262 			clp->c_cf = clp->c_cs;
263 	}
264 	if (clp->c_cc == 0)
265 		clp->c_cf = clp->c_cl = (u_char *)0;
266 out:
267 	splx(s);
268 }
269 
270 /*
271  * Put a character into the output queue.
272  */
273 int
274 putc(c, clp)
275 	int c;
276 	struct clist *clp;
277 {
278 	register u_char *q;
279 	register int i;
280 	int r = -1;
281 	int s;
282 
283 	s = spltty();
284 	if (clp->c_cc == clp->c_cn)
285 		goto out;
286 
287 	if (clp->c_cc == 0) {
288 		if (!clp->c_cs) {
289 #if defined(DIAGNOSTIC) || 1
290 			printf("putc: required clalloc\n");
291 #endif
292 			if(clalloc(clp, 1024, 1)) {
293 out:
294 				splx(s);
295 				return -1;
296 			}
297 		}
298 		clp->c_cf = clp->c_cl = clp->c_cs;
299 	}
300 
301 	*clp->c_cl = c & 0xff;
302 	i = clp->c_cl - clp->c_cs;
303 	if (clp->c_cq) {
304 #ifdef QBITS
305 		if (c & TTY_QUOTE)
306 			setbit(clp->c_cq, i);
307 		else
308 			clrbit(clp->c_cq, i);
309 #else
310 		q = clp->c_cq + i;
311 		*q = (c & TTY_QUOTE) ? 1 : 0;
312 #endif
313 	}
314 	clp->c_cc++;
315 	clp->c_cl++;
316 	if (clp->c_cl == clp->c_ce)
317 		clp->c_cl = clp->c_cs;
318 	splx(s);
319 	return 0;
320 }
321 
322 #ifdef QBITS
323 /*
324  * optimized version of
325  *
326  * for (i = 0; i < len; i++)
327  *	clrbit(cp, off + len);
328  */
329 void
330 clrbits(cp, off, len)
331 	u_char *cp;
332 	int off;
333 	int len;
334 {
335 	int sby, sbi, eby, ebi;
336 	register int i;
337 	u_char mask;
338 
339 	if(len==1) {
340 		clrbit(cp, off);
341 		return;
342 	}
343 
344 	sby = off / NBBY;
345 	sbi = off % NBBY;
346 	eby = (off+len) / NBBY;
347 	ebi = (off+len) % NBBY;
348 	if (sby == eby) {
349 		mask = ((1 << (ebi - sbi)) - 1) << sbi;
350 		cp[sby] &= ~mask;
351 	} else {
352 		mask = (1<<sbi) - 1;
353 		cp[sby++] &= mask;
354 
355 		mask = (1<<ebi) - 1;
356 		cp[eby] &= ~mask;
357 
358 		for (i = sby; i < eby; i++)
359 			cp[i] = 0x00;
360 	}
361 }
362 #endif
363 
364 /*
365  * Copy buffer to clist.
366  * Return number of bytes not transfered.
367  */
368 int
369 b_to_q(cp, count, clp)
370 	u_char *cp;
371 	int count;
372 	struct clist *clp;
373 {
374 	register int i, cc;
375 	register u_char *p = cp;
376 	int off, s;
377 
378 	if (count <= 0)
379 		return 0;
380 
381 	s = spltty();
382 	if (clp->c_cc == clp->c_cn)
383 		goto out;
384 
385 	if (clp->c_cc == 0) {
386 		if (!clp->c_cs) {
387 #if defined(DIAGNOSTIC) || 1
388 			printf("b_to_q: required clalloc\n");
389 #endif
390 			if(clalloc(clp, 1024, 1))
391 				goto out;
392 		}
393 		clp->c_cf = clp->c_cl = clp->c_cs;
394 	}
395 
396 	/* optimize this while loop */
397 	while (count > 0 && clp->c_cc < clp->c_cn) {
398 		cc = clp->c_ce - clp->c_cl;
399 		if (clp->c_cf > clp->c_cl)
400 			cc = clp->c_cf - clp->c_cl;
401 		if (cc > count)
402 			cc = count;
403 		bcopy(p, clp->c_cl, cc);
404 		if (clp->c_cq) {
405 #ifdef QBITS
406 			clrbits(clp->c_cq, clp->c_cl - clp->c_cs, cc);
407 #else
408 			bzero(clp->c_cl - clp->c_cs + clp->c_cq, cc);
409 #endif
410 		}
411 		p += cc;
412 		count -= cc;
413 		clp->c_cc += cc;
414 		clp->c_cl += cc;
415 		if (clp->c_cl == clp->c_ce)
416 			clp->c_cl = clp->c_cs;
417 	}
418 out:
419 	splx(s);
420 	return count;
421 }
422 
423 static int cc;
424 
425 /*
426  * Given a non-NULL pointer into the clist return the pointer
427  * to the next character in the list or return NULL if no more chars.
428  *
429  * Callers must not allow getc's to happen between firstc's and getc's
430  * so that the pointer becomes invalid.  Note that interrupts are NOT
431  * masked.
432  */
433 u_char *
434 nextc(clp, cp, c)
435 	struct clist *clp;
436 	register u_char *cp;
437 	int *c;
438 {
439 
440 	if (clp->c_cf == cp) {
441 		/*
442 		 * First time initialization.
443 		 */
444 		cc = clp->c_cc;
445 	}
446 	if (cc == 0 || cp == NULL)
447 		return NULL;
448 	if (--cc == 0)
449 		return NULL;
450 	if (++cp == clp->c_ce)
451 		cp = clp->c_cs;
452 	*c = *cp & 0xff;
453 	if (clp->c_cq) {
454 #ifdef QBITS
455 		if (isset(clp->c_cq, cp - clp->c_cs))
456 			*c |= TTY_QUOTE;
457 #else
458 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
459 			*c |= TTY_QUOTE;
460 #endif
461 	}
462 	return cp;
463 }
464 
465 /*
466  * Given a non-NULL pointer into the clist return the pointer
467  * to the first character in the list or return NULL if no more chars.
468  *
469  * Callers must not allow getc's to happen between firstc's and getc's
470  * so that the pointer becomes invalid.  Note that interrupts are NOT
471  * masked.
472  *
473  * *c is set to the NEXT character
474  */
475 u_char *
476 firstc(clp, c)
477 	struct clist *clp;
478 	int *c;
479 {
480 	int empty = 0;
481 	register u_char *cp;
482 	register int i;
483 
484 	cc = clp->c_cc;
485 	if (cc == 0)
486 		return NULL;
487 	cp = clp->c_cf;
488 	*c = *cp & 0xff;
489 	if(clp->c_cq) {
490 #ifdef QBITS
491 		if (isset(clp->c_cq, cp - clp->c_cs))
492 			*c |= TTY_QUOTE;
493 #else
494 		if (*(cp - clp->c_cs + clp->c_cq))
495 			*c |= TTY_QUOTE;
496 #endif
497 	}
498 	return clp->c_cf;
499 }
500 
501 /*
502  * Remove the last character in the clist and return it.
503  */
504 int
505 unputc(clp)
506 	struct clist *clp;
507 {
508 	unsigned int c = -1;
509 	int s;
510 
511 	s = spltty();
512 	if (clp->c_cc == 0)
513 		goto out;
514 
515 	if (clp->c_cl == clp->c_cs)
516 		clp->c_cl = clp->c_ce - 1;
517 	else
518 		--clp->c_cl;
519 	clp->c_cc--;
520 
521 	c = *clp->c_cl & 0xff;
522 	if (clp->c_cq) {
523 #ifdef QBITS
524 		if (isset(clp->c_cq, clp->c_cl - clp->c_cs))
525 			c |= TTY_QUOTE;
526 #else
527 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
528 			c |= TTY_QUOTE;
529 #endif
530 	}
531 	if (clp->c_cc == 0)
532 		clp->c_cf = clp->c_cl = (u_char *)0;
533 out:
534 	splx(s);
535 	return c;
536 }
537 
538 /*
539  * Put the chars in the from queue on the end of the to queue.
540  */
541 void
542 catq(from, to)
543 	struct clist *from, *to;
544 {
545 	int c;
546 
547 	while ((c = getc(from)) != -1)
548 		putc(c, to);
549 }
550