xref: /netbsd-src/sys/kern/tty_subr.c (revision cda4f8f6ee55684e8d311b86c99ea59191e6b74f)
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 1.1 1993/07/12 11:35:18 mycroft Exp $
23  */
24 
25 #include "param.h"
26 #include "systm.h"
27 #include "buf.h"
28 #include "ioctl.h"
29 #include "tty.h"
30 #include "clist.h"
31 #include "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, u_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, u_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 = (u_char *)0;
88 
89 	clp->c_cf = clp->c_cl = (u_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 = (u_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 = (u_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 	u_char *cp;
149 	int count;
150 {
151 	register int cc;
152 	u_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 = (u_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 || flag == 0)
192 		goto out;
193 
194 	i = clp->c_cf - clp->c_cs;
195 	while (cc-- > 0 && (clp->c_cs[i++] & flag) == 0) {
196 		count++;
197 		if (i == clp->c_cn)
198 			break;
199 	}
200 out:
201 	splx(s);
202 	return count;
203 }
204 
205 /*
206  * Flush count bytes from clist.
207  */
208 void
209 ndflush(clp, count)
210 	struct clist *clp;
211 	int count;
212 {
213 	register int cc;
214 	int s;
215 
216 	s = spltty();
217 	if (count == clp->c_cc) {
218 		clp->c_cc = 0;
219 		clp->c_cf = clp->c_cl = (u_char *)0;
220 		goto out;
221 	}
222 	/* optimize this while loop */
223 	while (count > 0 && clp->c_cc > 0) {
224 		cc = clp->c_cl - clp->c_cf;
225 		if (clp->c_cf >= clp->c_cl)
226 			cc = clp->c_ce - clp->c_cf;
227 		if (cc > count)
228 			cc = count;
229 		count -= cc;
230 		clp->c_cc -= cc;
231 		clp->c_cf += cc;
232 		if (clp->c_cf == clp->c_ce)
233 			clp->c_cf = clp->c_cs;
234 	}
235 	if (clp->c_cc == 0)
236 		clp->c_cf = clp->c_cl = (u_char *)0;
237 out:
238 	splx(s);
239 }
240 
241 /*
242  * Put a character into the output queue.
243  */
244 int
245 putc(c, clp)
246 	int c;
247 	struct clist *clp;
248 {
249 	register u_char *q;
250 	register int i;
251 	int r = -1;
252 	int s;
253 
254 	s = spltty();
255 	if (clp->c_cc == clp->c_cn)
256 		goto out;
257 
258 	if (clp->c_cc == 0) {
259 		if (!clp->c_cs) {
260 #if defined(DIAGNOSTIC) || 1
261 			printf("b_to_q: required clalloc\n");
262 #endif
263 			if(clalloc(clp, 1024, 1)) {
264 out:
265 				splx(s);
266 				return -1;
267 			}
268 		}
269 		clp->c_cf = clp->c_cl = clp->c_cs;
270 	}
271 
272 	*clp->c_cl = c & 0xff;
273 	i = clp->c_cl - clp->c_cs;
274 	if (clp->c_cq) {
275 #ifdef QBITS
276 		if (c & TTY_QUOTE)
277 			setbit(clp->c_cq, i);
278 		else
279 			clrbit(clp->c_cq, i);
280 #else
281 		q = clp->c_cq + i;
282 		*q = (c & TTY_QUOTE) ? 1 : 0;
283 #endif
284 	}
285 	clp->c_cc++;
286 	clp->c_cl++;
287 	if (clp->c_cl == clp->c_ce)
288 		clp->c_cl = clp->c_cs;
289 	splx(s);
290 	return 0;
291 }
292 
293 #ifdef QBITS
294 /*
295  * optimized version of
296  *
297  * for (i = 0; i < len; i++)
298  *	clrbit(cp, off + len);
299  */
300 void
301 clrbits(cp, off, len)
302 	u_char *cp;
303 	int off;
304 	int len;
305 {
306 	int sby, sbi, eby, ebi;
307 	register int i;
308 	u_char mask;
309 
310 	if(len==1) {
311 		clrbit(cp, off);
312 		return;
313 	}
314 
315 	sby = off / NBBY;
316 	sbi = off % NBBY;
317 	eby = (off+len) / NBBY;
318 	ebi = (off+len) % NBBY;
319 	if (sby == eby) {
320 		mask = ((1 << (ebi - sbi)) - 1) << sbi;
321 		cp[sby] &= ~mask;
322 	} else {
323 		mask = (1<<sbi) - 1;
324 		cp[sby++] &= mask;
325 
326 		mask = (1<<ebi) - 1;
327 		cp[eby] &= ~mask;
328 
329 		for (i = sby; i < eby; i++)
330 			cp[i] = 0x00;
331 	}
332 }
333 #endif
334 
335 /*
336  * Copy buffer to clist.
337  * Return number of bytes not transfered.
338  */
339 int
340 b_to_q(cp, count, clp)
341 	u_char *cp;
342 	int count;
343 	struct clist *clp;
344 {
345 	register int i, cc;
346 	register u_char *p = cp;
347 	int off, s;
348 
349 	if (count <= 0)
350 		return 0;
351 
352 	s = spltty();
353 	if (clp->c_cc == clp->c_cn)
354 		goto out;
355 
356 	if (clp->c_cc == 0) {
357 		if (!clp->c_cs) {
358 #if defined(DIAGNOSTIC) || 1
359 			printf("b_to_q: required clalloc\n");
360 #endif
361 			if(clalloc(clp, 1024, 1))
362 				goto out;
363 		}
364 		clp->c_cf = clp->c_cl = clp->c_cs;
365 	}
366 
367 	/* optimize this while loop */
368 	while (count > 0 && clp->c_cc < clp->c_cn) {
369 		cc = clp->c_ce - clp->c_cl;
370 		if (clp->c_cf > clp->c_cl)
371 			cc = clp->c_cf - clp->c_cl;
372 		if (cc > count)
373 			cc = count;
374 		bcopy(p, clp->c_cl, cc);
375 		if (clp->c_cq) {
376 #ifdef QBITS
377 			clrbits(clp->c_cq, clp->c_cl - clp->c_cs, cc);
378 #else
379 			bzero(clp->c_cl - clp->c_cs + clp->c_cq, cc);
380 #endif
381 		}
382 		p += cc;
383 		count -= cc;
384 		clp->c_cc += cc;
385 		clp->c_cl += cc;
386 		if (clp->c_cl == clp->c_ce)
387 			clp->c_cl = clp->c_cs;
388 	}
389 out:
390 	splx(s);
391 	return count;
392 }
393 
394 static int cc;
395 
396 /*
397  * Given a non-NULL pointer into the clist return the pointer
398  * to the next character in the list or return NULL if no more chars.
399  *
400  * Callers must not allow getc's to happen between firstc's and getc's
401  * so that the pointer becomes invalid.  Note that interrupts are NOT
402  * masked.
403  */
404 u_char *
405 nextc(clp, cp, c)
406 	struct clist *clp;
407 	register u_char *cp;
408 	int *c;
409 {
410 
411 	if (clp->c_cf == cp) {
412 		/*
413 		 * First time initialization.
414 		 */
415 		cc = clp->c_cc;
416 	}
417 	if (cc == 0 || cp == NULL)
418 		return NULL;
419 	if (--cc == 0)
420 		return NULL;
421 	if (++cp == clp->c_ce)
422 		cp = clp->c_cs;
423 	*c = *cp & 0xff;
424 	if (clp->c_cq) {
425 #ifdef QBITS
426 		if (isset(clp->c_cq, cp - clp->c_cs))
427 			*c |= TTY_QUOTE;
428 #else
429 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
430 			*c |= TTY_QUOTE;
431 #endif
432 	}
433 	return cp;
434 }
435 
436 /*
437  * Given a non-NULL pointer into the clist return the pointer
438  * to the first character in the list or return NULL if no more chars.
439  *
440  * Callers must not allow getc's to happen between firstc's and getc's
441  * so that the pointer becomes invalid.  Note that interrupts are NOT
442  * masked.
443  *
444  * *c is set to the NEXT character
445  */
446 u_char *
447 firstc(clp, c)
448 	struct clist *clp;
449 	int *c;
450 {
451 	int empty = 0;
452 	register u_char *cp;
453 	register int i;
454 
455 	cc = clp->c_cc;
456 	if (cc == 0)
457 		return NULL;
458 	cp = clp->c_cf;
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 (*(cp - clp->c_cs + clp->c_cq))
466 			*c |= TTY_QUOTE;
467 #endif
468 	}
469 	return clp->c_cf;
470 }
471 
472 /*
473  * Remove the last character in the clist and return it.
474  */
475 int
476 unputc(clp)
477 	struct clist *clp;
478 {
479 	unsigned int c = -1;
480 	int s;
481 
482 	s = spltty();
483 	if (clp->c_cc == 0)
484 		goto out;
485 
486 	if (clp->c_cl == clp->c_cs)
487 		clp->c_cl = clp->c_ce - 1;
488 	else
489 		--clp->c_cl;
490 	clp->c_cc--;
491 
492 	c = *clp->c_cl & 0xff;
493 	if (clp->c_cq) {
494 #ifdef QBITS
495 		if (isset(clp->c_cq, clp->c_cl - clp->c_cs))
496 			c |= TTY_QUOTE;
497 #else
498 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
499 			c | TTY_QUOTE;
500 #endif
501 	}
502 	if (clp->c_cc == 0)
503 		clp->c_cf = clp->c_cl = (u_char *)0;
504 out:
505 	splx(s);
506 	return c;
507 }
508 
509 /*
510  * Put the chars in the from queue on the end of the to queue.
511  */
512 void
513 catq(from, to)
514 	struct clist *from, *to;
515 {
516 	int c;
517 
518 	while ((c = getc(from)) != -1)
519 		putc(c, to);
520 }
521