Home | History | Annotate | Line # | Download | only in kern
tty_subr.c revision 1.33 
      1 /*	$NetBSD: tty_subr.c,v 1.33 2008/05/25 19:22:21 ad 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  *
     19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include <sys/cdefs.h>
     32 __KERNEL_RCSID(0, "$NetBSD: tty_subr.c,v 1.33 2008/05/25 19:22:21 ad Exp $");
     33 
     34 #include <sys/param.h>
     35 #include <sys/systm.h>
     36 #include <sys/buf.h>
     37 #include <sys/ioctl.h>
     38 #include <sys/tty.h>
     39 #include <sys/malloc.h>
     40 
     41 MALLOC_DEFINE(M_TTYS, "ttys", "allocated tty structures");
     42 
     43 /*
     44  * At compile time, choose:
     45  * There are two ways the TTY_QUOTE bit can be stored. If QBITS is
     46  * defined we allocate an array of bits -- 1/8th as much memory but
     47  * setbit(), clrbit(), and isset() take more CPU. If QBITS is
     48  * undefined, we just use an array of bytes.
     49  *
     50  * If TTY_QUOTE functionality isn't required by a line discipline,
     51  * it can free c_cq and set it to NULL. This speeds things up,
     52  * and also does not use any extra memory. This is useful for (say)
     53  * a SLIP line discipline that wants a 32K ring buffer for data
     54  * but doesn't need quoting.
     55  */
     56 #define QBITS
     57 
     58 #ifdef QBITS
     59 #define QMEM(n)		((((n)-1)/NBBY)+1)
     60 #else
     61 #define QMEM(n)		(n)
     62 #endif
     63 
     64 #ifdef QBITS
     65 static void	clrbits(u_char *, int, int);
     66 #endif
     67 
     68 /*
     69  * Initialize a particular clist. Ok, they are really ring buffers,
     70  * of the specified length, with/without quoting support.
     71  */
     72 int
     73 clalloc(struct clist *clp, int size, int quot)
     74 {
     75 
     76 	clp->c_cs = malloc(size, M_TTYS, M_WAITOK);
     77 	if (!clp->c_cs)
     78 		return (-1);
     79 	memset(clp->c_cs, 0, size);
     80 
     81 	if(quot) {
     82 		clp->c_cq = malloc(QMEM(size), M_TTYS, M_WAITOK);
     83 		if (!clp->c_cq) {
     84 			free(clp->c_cs, M_TTYS);
     85 			return (-1);
     86 		}
     87 		memset(clp->c_cq, 0, QMEM(size));
     88 	} else
     89 		clp->c_cq = (u_char *)0;
     90 
     91 	clp->c_cf = clp->c_cl = (u_char *)0;
     92 	clp->c_ce = clp->c_cs + size;
     93 	clp->c_cn = size;
     94 	clp->c_cc = 0;
     95 
     96 	return (0);
     97 }
     98 
     99 void
    100 clfree(struct clist *clp)
    101 {
    102 	if(clp->c_cs)
    103 		free(clp->c_cs, M_TTYS);
    104 	if(clp->c_cq)
    105 		free(clp->c_cq, M_TTYS);
    106 	clp->c_cs = clp->c_cq = (u_char *)0;
    107 }
    108 
    109 /*
    110  * Get a character from a clist.
    111  */
    112 int
    113 getc(struct clist *clp)
    114 {
    115 	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(struct clist *clp, u_char *cp, int count)
    147 {
    148 	int cc;
    149 	u_char *p = cp;
    150 	int s;
    151 
    152 	s = spltty();
    153 	/* optimize this while loop */
    154 	while (count > 0 && clp->c_cc > 0) {
    155 		cc = clp->c_cl - clp->c_cf;
    156 		if (clp->c_cf >= clp->c_cl)
    157 			cc = clp->c_ce - clp->c_cf;
    158 		if (cc > count)
    159 			cc = count;
    160 		memcpy(p, clp->c_cf, cc);
    161 		count -= cc;
    162 		p += cc;
    163 		clp->c_cc -= cc;
    164 		clp->c_cf += cc;
    165 		if (clp->c_cf == clp->c_ce)
    166 			clp->c_cf = clp->c_cs;
    167 	}
    168 	if (clp->c_cc == 0)
    169 		clp->c_cf = clp->c_cl = (u_char *)0;
    170 	splx(s);
    171 	return p - cp;
    172 }
    173 
    174 /*
    175  * Return count of contiguous characters in clist.
    176  * Stop counting if flag&character is non-null.
    177  */
    178 int
    179 ndqb(struct clist *clp, int flag)
    180 {
    181 	int count = 0;
    182 	int i;
    183 	int cc;
    184 	int s;
    185 
    186 	s = spltty();
    187 	if ((cc = clp->c_cc) == 0)
    188 		goto out;
    189 
    190 	if (flag == 0) {
    191 		count = clp->c_cl - clp->c_cf;
    192 		if (count <= 0)
    193 			count = clp->c_ce - clp->c_cf;
    194 		goto out;
    195 	}
    196 
    197 	i = clp->c_cf - clp->c_cs;
    198 	if (flag & TTY_QUOTE) {
    199 		while (cc-- > 0 && !(clp->c_cs[i++] & (flag & ~TTY_QUOTE) ||
    200 		    isset(clp->c_cq, i))) {
    201 			count++;
    202 			if (i == clp->c_cn)
    203 				break;
    204 		}
    205 	} else {
    206 		while (cc-- > 0 && !(clp->c_cs[i++] & flag)) {
    207 			count++;
    208 			if (i == clp->c_cn)
    209 				break;
    210 		}
    211 	}
    212 out:
    213 	splx(s);
    214 	return count;
    215 }
    216 
    217 /*
    218  * Flush count bytes from clist.
    219  */
    220 void
    221 ndflush(struct clist *clp, int count)
    222 {
    223 	int cc;
    224 	int s;
    225 
    226 	s = spltty();
    227 	if (count == clp->c_cc) {
    228 		clp->c_cc = 0;
    229 		clp->c_cf = clp->c_cl = (u_char *)0;
    230 		goto out;
    231 	}
    232 	/* optimize this while loop */
    233 	while (count > 0 && clp->c_cc > 0) {
    234 		cc = clp->c_cl - clp->c_cf;
    235 		if (clp->c_cf >= clp->c_cl)
    236 			cc = clp->c_ce - clp->c_cf;
    237 		if (cc > count)
    238 			cc = count;
    239 		count -= cc;
    240 		clp->c_cc -= cc;
    241 		clp->c_cf += cc;
    242 		if (clp->c_cf == clp->c_ce)
    243 			clp->c_cf = clp->c_cs;
    244 	}
    245 	if (clp->c_cc == 0)
    246 		clp->c_cf = clp->c_cl = (u_char *)0;
    247 out:
    248 	splx(s);
    249 }
    250 
    251 /*
    252  * Put a character into the output queue.
    253  */
    254 int
    255 putc(int c, struct clist *clp)
    256 {
    257 	int i;
    258 	int s;
    259 
    260 	s = spltty();
    261 	if (clp->c_cc == clp->c_cn)
    262 		goto out;
    263 
    264 	if (clp->c_cc == 0) {
    265 		if (!clp->c_cs) {
    266 #if defined(DIAGNOSTIC) || 1
    267 			printf("putc: required clalloc\n");
    268 #endif
    269 			if(clalloc(clp, 1024, 1)) {
    270 out:
    271 				splx(s);
    272 				return -1;
    273 			}
    274 		}
    275 		clp->c_cf = clp->c_cl = clp->c_cs;
    276 	}
    277 
    278 	*clp->c_cl = c & 0xff;
    279 	i = clp->c_cl - clp->c_cs;
    280 	if (clp->c_cq) {
    281 #ifdef QBITS
    282 		if (c & TTY_QUOTE)
    283 			setbit(clp->c_cq, i);
    284 		else
    285 			clrbit(clp->c_cq, i);
    286 #else
    287 		q = clp->c_cq + i;
    288 		*q = (c & TTY_QUOTE) ? 1 : 0;
    289 #endif
    290 	}
    291 	clp->c_cc++;
    292 	clp->c_cl++;
    293 	if (clp->c_cl == clp->c_ce)
    294 		clp->c_cl = clp->c_cs;
    295 	splx(s);
    296 	return 0;
    297 }
    298 
    299 #ifdef QBITS
    300 /*
    301  * optimized version of
    302  *
    303  * for (i = 0; i < len; i++)
    304  *	clrbit(cp, off + len);
    305  */
    306 static void
    307 clrbits(u_char *cp, int off, int len)
    308 {
    309 	int sby, sbi, eby, ebi;
    310 	int i;
    311 	u_char mask;
    312 
    313 	if(len==1) {
    314 		clrbit(cp, off);
    315 		return;
    316 	}
    317 
    318 	sby = off / NBBY;
    319 	sbi = off % NBBY;
    320 	eby = (off+len) / NBBY;
    321 	ebi = (off+len) % NBBY;
    322 	if (sby == eby) {
    323 		mask = ((1 << (ebi - sbi)) - 1) << sbi;
    324 		cp[sby] &= ~mask;
    325 	} else {
    326 		mask = (1<<sbi) - 1;
    327 		cp[sby++] &= mask;
    328 
    329 		mask = (1<<ebi) - 1;
    330 		cp[eby] &= ~mask;
    331 
    332 		for (i = sby; i < eby; i++)
    333 			cp[i] = 0x00;
    334 	}
    335 }
    336 #endif
    337 
    338 /*
    339  * Copy buffer to clist.
    340  * Return number of bytes not transfered.
    341  */
    342 int
    343 b_to_q(const u_char *cp, int count, struct clist *clp)
    344 {
    345 	int cc;
    346 	const u_char *p = cp;
    347 	int 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 		memcpy(clp->c_cl, p, cc);
    375 		if (clp->c_cq) {
    376 #ifdef QBITS
    377 			clrbits(clp->c_cq, clp->c_cl - clp->c_cs, cc);
    378 #else
    379 			memset(clp->c_cl - clp->c_cs + clp->c_cq, 0, 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(struct clist *clp, u_char *cp, int *c)
    406 {
    407 
    408 	if (clp->c_cf == cp) {
    409 		/*
    410 		 * First time initialization.
    411 		 */
    412 		cc = clp->c_cc;
    413 	}
    414 	if (cc == 0 || cp == NULL)
    415 		return NULL;
    416 	if (--cc == 0)
    417 		return NULL;
    418 	if (++cp == clp->c_ce)
    419 		cp = clp->c_cs;
    420 	*c = *cp & 0xff;
    421 	if (clp->c_cq) {
    422 #ifdef QBITS
    423 		if (isset(clp->c_cq, cp - clp->c_cs))
    424 			*c |= TTY_QUOTE;
    425 #else
    426 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
    427 			*c |= TTY_QUOTE;
    428 #endif
    429 	}
    430 	return cp;
    431 }
    432 
    433 /*
    434  * Given a non-NULL pointer into the clist return the pointer
    435  * to the first character in the list or return NULL if no more chars.
    436  *
    437  * Callers must not allow getc's to happen between firstc's and getc's
    438  * so that the pointer becomes invalid.  Note that interrupts are NOT
    439  * masked.
    440  *
    441  * *c is set to the NEXT character
    442  */
    443 u_char *
    444 firstc(struct clist *clp, int *c)
    445 {
    446 	u_char *cp;
    447 
    448 	cc = clp->c_cc;
    449 	if (cc == 0)
    450 		return NULL;
    451 	cp = clp->c_cf;
    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 (*(cp - clp->c_cs + clp->c_cq))
    459 			*c |= TTY_QUOTE;
    460 #endif
    461 	}
    462 	return clp->c_cf;
    463 }
    464 
    465 /*
    466  * Remove the last character in the clist and return it.
    467  */
    468 int
    469 unputc(struct clist *clp)
    470 {
    471 	unsigned int c = -1;
    472 	int s;
    473 
    474 	s = spltty();
    475 	if (clp->c_cc == 0)
    476 		goto out;
    477 
    478 	if (clp->c_cl == clp->c_cs)
    479 		clp->c_cl = clp->c_ce - 1;
    480 	else
    481 		--clp->c_cl;
    482 	clp->c_cc--;
    483 
    484 	c = *clp->c_cl & 0xff;
    485 	if (clp->c_cq) {
    486 #ifdef QBITS
    487 		if (isset(clp->c_cq, clp->c_cl - clp->c_cs))
    488 			c |= TTY_QUOTE;
    489 #else
    490 		if (*(clp->c_cf - clp->c_cs + clp->c_cq))
    491 			c |= TTY_QUOTE;
    492 #endif
    493 	}
    494 	if (clp->c_cc == 0)
    495 		clp->c_cf = clp->c_cl = (u_char *)0;
    496 out:
    497 	splx(s);
    498 	return c;
    499 }
    500 
    501 /*
    502  * Put the chars in the from queue on the end of the to queue.
    503  */
    504 void
    505 catq(struct clist *from, struct clist *to)
    506 {
    507 	int c;
    508 
    509 	while ((c = getc(from)) != -1)
    510 		putc(c, to);
    511 }
    512