xref: /netbsd-src/sys/kern/tty_subr.c (revision ae1bfcddc410612bc8c58b807e1830becb69a24c)
1 /*
2  * Copyright (c) 1993 Theo de Raadt
3  * All rights reserved.
4  *
5  * Per Lindqvist <pgd@compuram.bbt.se> supplied an almost fully working
6  * set of true clist functions that this is very loosely based on.
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  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by Theo de Raadt.
19  * 4. The name of Theo de Raadt may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission.
21  *
22  *	$Id: tty_subr.c,v 1.6 1994/05/05 05:38:43 cgd Exp $
23  */
24 
25 #include <sys/param.h>
26 #include <sys/systm.h>
27 #include <sys/buf.h>
28 #include <sys/ioctl.h>
29 #include <sys/tty.h>
30 #include <sys/clist.h>
31 #include <sys/malloc.h>
32 
33 /*
34  * At compile time, choose:
35  * There are two ways the TTY_QUOTE bit can be stored. If QBITS is
36  * defined we allocate an array of bits -- 1/8th as much memory but
37  * setbit(), clrbit(), and isset() take more cpu. If QBITS is
38  * undefined, we just use an array of bytes.
39  *
40  * If TTY_QUOTE functionality isn't required by a line discipline,
41  * it can free c_cq and set it to NULL. This speeds things up,
42  * and also does not use any extra memory. This is useful for (say)
43  * a SLIP line discipline that wants a 32K ring buffer for data
44  * but doesn't need quoting.
45  */
46 #define QBITS
47 
48 #ifdef QBITS
49 #define QMEM(n)		((((n)-1)/NBBY)+1)
50 #else
51 #define QMEM(n)		(n)
52 #endif
53 
54 
55 /*
56  * Initialize clists.
57  */
58 void
59 cinit()
60 {
61 }
62 
63 /*
64  * Initialize a particular clist. Ok, they are really ring buffers,
65  * of the specified length, with/without quoting support.
66  */
67 int
68 clalloc(clp, size, quot)
69 	struct clist *clp;
70 	int size;
71 	int quot;
72 {
73 
74 	MALLOC(clp->c_cs, char *, size, M_TTYS, M_WAITOK);
75 	if (!clp->c_cs)
76 		return (-1);
77 	bzero(clp->c_cs, size);
78 
79 	if(quot) {
80 		MALLOC(clp->c_cq, char *, QMEM(size), M_TTYS, M_WAITOK);
81 		if (!clp->c_cq) {
82 			FREE(clp->c_cs, M_TTYS);
83 			return (-1);
84 		}
85 		bzero(clp->c_cs, QMEM(size));
86 	} else
87 		clp->c_cq = (char *)0;
88 
89 	clp->c_cf = clp->c_cl = (char *)0;
90 	clp->c_ce = clp->c_cs + size;
91 	clp->c_cn = size;
92 	clp->c_cc = 0;
93 	return (0);
94 }
95 
96 void
97 clfree(clp)
98 	struct clist *clp;
99 {
100 	if(clp->c_cs)
101 		FREE(clp->c_cs, M_TTYS);
102 	if(clp->c_cq)
103 		FREE(clp->c_cq, M_TTYS);
104 	clp->c_cs = clp->c_cq = (char *)0;
105 }
106 
107 
108 /*
109  * Get a character from a clist.
110  */
111 int
112 getc(clp)
113 	struct clist *clp;
114 {
115 	register int c = -1;
116 	int s;
117 
118 	s = spltty();
119 	if (clp->c_cc == 0)
120 		goto out;
121 
122 	c = *clp->c_cf & 0xff;
123 	if (clp->c_cq) {
124 #ifdef QBITS
125 		if (isset(clp->c_cq, clp->c_cf - clp->c_cs) )
126 			c |= TTY_QUOTE;
127 #else
128 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
129 			c |= TTY_QUOTE;
130 #endif
131 	}
132 	if (++clp->c_cf == clp->c_ce)
133 		clp->c_cf = clp->c_cs;
134 	if (--clp->c_cc == 0)
135 		clp->c_cf = clp->c_cl = (char *)0;
136 out:
137 	splx(s);
138 	return c;
139 }
140 
141 /*
142  * Copy clist to buffer.
143  * Return number of bytes moved.
144  */
145 int
146 q_to_b(clp, cp, count)
147 	struct clist *clp;
148 	char *cp;
149 	int count;
150 {
151 	register int cc;
152 	char *p = cp;
153 	int s;
154 
155 	s = spltty();
156 	/* optimize this while loop */
157 	while (count > 0 && clp->c_cc > 0) {
158 		cc = clp->c_cl - clp->c_cf;
159 		if (clp->c_cf >= clp->c_cl)
160 			cc = clp->c_ce - clp->c_cf;
161 		if (cc > count)
162 			cc = count;
163 		bcopy(clp->c_cf, p, cc);
164 		count -= cc;
165 		p += cc;
166 		clp->c_cc -= cc;
167 		clp->c_cf += cc;
168 		if (clp->c_cf == clp->c_ce)
169 			clp->c_cf = clp->c_cs;
170 	}
171 	if (clp->c_cc == 0)
172 		clp->c_cf = clp->c_cl = (char *)0;
173 	splx(s);
174 	return p - cp;
175 }
176 
177 /*
178  * Return count of contiguous characters in clist.
179  * Stop counting if flag&character is non-null.
180  */
181 ndqb(clp, flag)
182 	struct clist *clp;
183 	int flag;
184 {
185 	int count = 0;
186 	register int i;
187 	register int cc;
188 	int s;
189 
190 	s = spltty();
191 	if ((cc = clp->c_cc) == 0)
192 		goto out;
193 
194 	if (flag == 0) {
195 		count = clp->c_cl - clp->c_cf;
196 		if (count < 0)
197 			count = clp->c_ce - clp->c_cf;
198 		goto out;
199 	}
200 
201 	i = clp->c_cf - clp->c_cs;
202 	if(flag & TTY_QUOTE) {
203 		while (cc-- > 0 && (clp->c_cs[i++] & (flag & ~TTY_QUOTE)) &&
204 		    !isset(clp->c_cq, i)) {
205 			count++;
206 			if (i == clp->c_cn)
207 				break;
208 		}
209 	} else {
210 		while (cc-- > 0 && (clp->c_cs[i++] & flag)) {
211 			count++;
212 			if (i == clp->c_cn)
213 				break;
214 		}
215 	}
216 out:
217 	splx(s);
218 	return count;
219 }
220 
221 /*
222  * Flush count bytes from clist.
223  */
224 void
225 ndflush(clp, count)
226 	struct clist *clp;
227 	int count;
228 {
229 	register int cc;
230 	int s;
231 
232 	s = spltty();
233 	if (count == clp->c_cc) {
234 		clp->c_cc = 0;
235 		clp->c_cf = clp->c_cl = (char *)0;
236 		goto out;
237 	}
238 	/* optimize this while loop */
239 	while (count > 0 && clp->c_cc > 0) {
240 		cc = clp->c_cl - clp->c_cf;
241 		if (clp->c_cf >= clp->c_cl)
242 			cc = clp->c_ce - clp->c_cf;
243 		if (cc > count)
244 			cc = count;
245 		count -= cc;
246 		clp->c_cc -= cc;
247 		clp->c_cf += cc;
248 		if (clp->c_cf == clp->c_ce)
249 			clp->c_cf = clp->c_cs;
250 	}
251 	if (clp->c_cc == 0)
252 		clp->c_cf = clp->c_cl = (char *)0;
253 out:
254 	splx(s);
255 }
256 
257 /*
258  * Put a character into the output queue.
259  */
260 int
261 putc(c, clp)
262 	int c;
263 	struct clist *clp;
264 {
265 	register char *q;
266 	register int i;
267 	int r = -1;
268 	int s;
269 
270 	s = spltty();
271 	if (clp->c_cc == clp->c_cn)
272 		goto out;
273 
274 	if (clp->c_cc == 0) {
275 		if (!clp->c_cs) {
276 #if defined(DIAGNOSTIC) || 1
277 			printf("putc: required clalloc\n");
278 #endif
279 			if(clalloc(clp, 1024, 1)) {
280 out:
281 				splx(s);
282 				return -1;
283 			}
284 		}
285 		clp->c_cf = clp->c_cl = clp->c_cs;
286 	}
287 
288 	*clp->c_cl = c & 0xff;
289 	i = clp->c_cl - clp->c_cs;
290 	if (clp->c_cq) {
291 #ifdef QBITS
292 		if (c & TTY_QUOTE)
293 			setbit(clp->c_cq, i);
294 		else
295 			clrbit(clp->c_cq, i);
296 #else
297 		q = clp->c_cq + i;
298 		*q = (c & TTY_QUOTE) ? 1 : 0;
299 #endif
300 	}
301 	clp->c_cc++;
302 	clp->c_cl++;
303 	if (clp->c_cl == clp->c_ce)
304 		clp->c_cl = clp->c_cs;
305 	splx(s);
306 	return 0;
307 }
308 
309 #ifdef QBITS
310 /*
311  * optimized version of
312  *
313  * for (i = 0; i < len; i++)
314  *	clrbit(cp, off + len);
315  */
316 void
317 clrbits(cp, off, len)
318 	char *cp;
319 	int off;
320 	int len;
321 {
322 	int sby, sbi, eby, ebi;
323 	register int i;
324 	char mask;
325 
326 	if(len==1) {
327 		clrbit(cp, off);
328 		return;
329 	}
330 
331 	sby = off / NBBY;
332 	sbi = off % NBBY;
333 	eby = (off+len) / NBBY;
334 	ebi = (off+len) % NBBY;
335 	if (sby == eby) {
336 		mask = ((1 << (ebi - sbi)) - 1) << sbi;
337 		cp[sby] &= ~mask;
338 	} else {
339 		mask = (1<<sbi) - 1;
340 		cp[sby++] &= mask;
341 
342 		mask = (1<<ebi) - 1;
343 		cp[eby] &= ~mask;
344 
345 		for (i = sby; i < eby; i++)
346 			cp[i] = 0x00;
347 	}
348 }
349 #endif
350 
351 /*
352  * Copy buffer to clist.
353  * Return number of bytes not transfered.
354  */
355 int
356 b_to_q(cp, count, clp)
357 	char *cp;
358 	int count;
359 	struct clist *clp;
360 {
361 	register int i, cc;
362 	register char *p = cp;
363 	int off, s;
364 
365 	if (count <= 0)
366 		return 0;
367 
368 	s = spltty();
369 	if (clp->c_cc == clp->c_cn)
370 		goto out;
371 
372 	if (clp->c_cc == 0) {
373 		if (!clp->c_cs) {
374 #if defined(DIAGNOSTIC) || 1
375 			printf("b_to_q: required clalloc\n");
376 #endif
377 			if(clalloc(clp, 1024, 1))
378 				goto out;
379 		}
380 		clp->c_cf = clp->c_cl = clp->c_cs;
381 	}
382 
383 	/* optimize this while loop */
384 	while (count > 0 && clp->c_cc < clp->c_cn) {
385 		cc = clp->c_ce - clp->c_cl;
386 		if (clp->c_cf > clp->c_cl)
387 			cc = clp->c_cf - clp->c_cl;
388 		if (cc > count)
389 			cc = count;
390 		bcopy(p, clp->c_cl, cc);
391 		if (clp->c_cq) {
392 #ifdef QBITS
393 			clrbits(clp->c_cq, clp->c_cl - clp->c_cs, cc);
394 #else
395 			bzero(clp->c_cl - clp->c_cs + clp->c_cq, cc);
396 #endif
397 		}
398 		p += cc;
399 		count -= cc;
400 		clp->c_cc += cc;
401 		clp->c_cl += cc;
402 		if (clp->c_cl == clp->c_ce)
403 			clp->c_cl = clp->c_cs;
404 	}
405 out:
406 	splx(s);
407 	return count;
408 }
409 
410 static int cc;
411 
412 /*
413  * Given a non-NULL pointer into the clist return the pointer
414  * to the next character in the list or return NULL if no more chars.
415  *
416  * Callers must not allow getc's to happen between firstc's and getc's
417  * so that the pointer becomes invalid.  Note that interrupts are NOT
418  * masked.
419  */
420 char *
421 nextc(clp, cp, c)
422 	struct clist *clp;
423 	register char *cp;
424 	int *c;
425 {
426 
427 	if (clp->c_cf == cp) {
428 		/*
429 		 * First time initialization.
430 		 */
431 		cc = clp->c_cc;
432 	}
433 	if (cc == 0 || cp == NULL)
434 		return NULL;
435 	if (--cc == 0)
436 		return NULL;
437 	if (++cp == clp->c_ce)
438 		cp = clp->c_cs;
439 	*c = *cp & 0xff;
440 	if (clp->c_cq) {
441 #ifdef QBITS
442 		if (isset(clp->c_cq, cp - clp->c_cs))
443 			*c |= TTY_QUOTE;
444 #else
445 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
446 			*c |= TTY_QUOTE;
447 #endif
448 	}
449 	return cp;
450 }
451 
452 /*
453  * Given a non-NULL pointer into the clist return the pointer
454  * to the first character in the list or return NULL if no more chars.
455  *
456  * Callers must not allow getc's to happen between firstc's and getc's
457  * so that the pointer becomes invalid.  Note that interrupts are NOT
458  * masked.
459  *
460  * *c is set to the NEXT character
461  */
462 char *
463 firstc(clp, c)
464 	struct clist *clp;
465 	int *c;
466 {
467 	int empty = 0;
468 	register char *cp;
469 	register int i;
470 
471 	cc = clp->c_cc;
472 	if (cc == 0)
473 		return NULL;
474 	cp = clp->c_cf;
475 	*c = *cp & 0xff;
476 	if(clp->c_cq) {
477 #ifdef QBITS
478 		if (isset(clp->c_cq, cp - clp->c_cs))
479 			*c |= TTY_QUOTE;
480 #else
481 		if (*(cp - clp->c_cs + clp->c_cq))
482 			*c |= TTY_QUOTE;
483 #endif
484 	}
485 	return clp->c_cf;
486 }
487 
488 /*
489  * Remove the last character in the clist and return it.
490  */
491 int
492 unputc(clp)
493 	struct clist *clp;
494 {
495 	unsigned int c = -1;
496 	int s;
497 
498 	s = spltty();
499 	if (clp->c_cc == 0)
500 		goto out;
501 
502 	if (clp->c_cl == clp->c_cs)
503 		clp->c_cl = clp->c_ce - 1;
504 	else
505 		--clp->c_cl;
506 	clp->c_cc--;
507 
508 	c = *clp->c_cl & 0xff;
509 	if (clp->c_cq) {
510 #ifdef QBITS
511 		if (isset(clp->c_cq, clp->c_cl - clp->c_cs))
512 			c |= TTY_QUOTE;
513 #else
514 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
515 			c |= TTY_QUOTE;
516 #endif
517 	}
518 	if (clp->c_cc == 0)
519 		clp->c_cf = clp->c_cl = (char *)0;
520 out:
521 	splx(s);
522 	return c;
523 }
524 
525 /*
526  * Put the chars in the from queue on the end of the to queue.
527  */
528 void
529 catq(from, to)
530 	struct clist *from, *to;
531 {
532 	int c;
533 
534 	while ((c = getc(from)) != -1)
535 		putc(c, to);
536 }
537