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tty_subr.c revision 1.13 
      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 (at) 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