| 1 | /* $NetBSD: tty_subr.c,v 1.40 2011/09/24 00:05:38 christos 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 | * |
| 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 1.40 2011/09/24 00:05:38 christos 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/kmem.h> |
| 40 | |
| 41 | /* |
| 42 | * At compile time, choose: |
| 43 | * There are two ways the TTY_QUOTE bit can be stored. If QBITS is |
| 44 | * defined we allocate an array of bits -- 1/8th as much memory but |
| 45 | * setbit(), clrbit(), and isset() take more CPU. If QBITS is |
| 46 | * undefined, we just use an array of bytes. |
| 47 | * |
| 48 | * If TTY_QUOTE functionality isn't required by a line discipline, |
| 49 | * it can free c_cq and set it to NULL. This speeds things up, |
| 50 | * and also does not use any extra memory. This is useful for (say) |
| 51 | * a SLIP line discipline that wants a 32K ring buffer for data |
| 52 | * but doesn't need quoting. |
| 53 | */ |
| 54 | #define QBITS |
| 55 | |
| 56 | #ifdef QBITS |
| 57 | #define QMEM(n) ((((n)-1)/NBBY)+1) |
| 58 | #else |
| 59 | #define QMEM(n) (n) |
| 60 | #endif |
| 61 | |
| 62 | #ifdef QBITS |
| 63 | static void clrbits(u_char *, unsigned int, unsigned int); |
| 64 | #endif |
| 65 | |
| 66 | /* |
| 67 | * Initialize a particular clist. Ok, they are really ring buffers, |
| 68 | * of the specified length, with/without quoting support. |
| 69 | */ |
| 70 | int |
| 71 | clalloc(struct clist *clp, int size, int quot) |
| 72 | { |
| 73 | |
| 74 | clp->c_cs = kmem_zalloc(size, KM_SLEEP); |
| 75 | if (!clp->c_cs) |
| 76 | return (-1); |
| 77 | |
| 78 | if (quot) { |
| 79 | clp->c_cq = kmem_zalloc(QMEM(size), KM_SLEEP); |
| 80 | if (!clp->c_cq) { |
| 81 | kmem_free(clp->c_cs, size); |
| 82 | return (-1); |
| 83 | } |
| 84 | } else |
| 85 | clp->c_cq = NULL; |
| 86 | |
| 87 | clp->c_cf = clp->c_cl = NULL; |
| 88 | clp->c_ce = clp->c_cs + size; |
| 89 | clp->c_cn = size; |
| 90 | clp->c_cc = 0; |
| 91 | |
| 92 | return (0); |
| 93 | } |
| 94 | |
| 95 | void |
| 96 | clfree(struct clist *clp) |
| 97 | { |
| 98 | if (clp->c_cs) |
| 99 | kmem_free(clp->c_cs, clp->c_cn); |
| 100 | if (clp->c_cq) |
| 101 | kmem_free(clp->c_cq, QMEM(clp->c_cn)); |
| 102 | clp->c_cs = clp->c_cq = NULL; |
| 103 | } |
| 104 | |
| 105 | /* |
| 106 | * Get a character from a clist. |
| 107 | */ |
| 108 | int |
| 109 | getc(struct clist *clp) |
| 110 | { |
| 111 | int c = -1; |
| 112 | int s; |
| 113 | |
| 114 | s = spltty(); |
| 115 | if (clp->c_cc == 0) |
| 116 | goto out; |
| 117 | |
| 118 | c = *clp->c_cf & 0xff; |
| 119 | if (clp->c_cq) { |
| 120 | #ifdef QBITS |
| 121 | if (isset(clp->c_cq, clp->c_cf - clp->c_cs) ) |
| 122 | c |= TTY_QUOTE; |
| 123 | #else |
| 124 | if (*(clp->c_cf - clp->c_cs + clp->c_cq)) |
| 125 | c |= TTY_QUOTE; |
| 126 | #endif |
| 127 | } |
| 128 | *clp->c_cf = 0; /* wipe out to avoid information disclosure */ |
| 129 | if (++clp->c_cf == clp->c_ce) |
| 130 | clp->c_cf = clp->c_cs; |
| 131 | if (--clp->c_cc == 0) |
| 132 | clp->c_cf = clp->c_cl = (u_char *)0; |
| 133 | out: |
| 134 | splx(s); |
| 135 | return c; |
| 136 | } |
| 137 | |
| 138 | /* |
| 139 | * Copy clist to buffer. |
| 140 | * Return number of bytes moved. |
| 141 | */ |
| 142 | int |
| 143 | q_to_b(struct clist *clp, u_char *cp, int count) |
| 144 | { |
| 145 | int cc; |
| 146 | u_char *p = cp; |
| 147 | int s; |
| 148 | |
| 149 | s = spltty(); |
| 150 | /* optimize this while loop */ |
| 151 | while (count > 0 && clp->c_cc > 0) { |
| 152 | cc = clp->c_cl - clp->c_cf; |
| 153 | if (clp->c_cf >= clp->c_cl) |
| 154 | cc = clp->c_ce - clp->c_cf; |
| 155 | if (cc > count) |
| 156 | cc = count; |
| 157 | memcpy(p, clp->c_cf, cc); |
| 158 | count -= cc; |
| 159 | p += cc; |
| 160 | clp->c_cc -= cc; |
| 161 | clp->c_cf += cc; |
| 162 | if (clp->c_cf == clp->c_ce) |
| 163 | clp->c_cf = clp->c_cs; |
| 164 | } |
| 165 | if (clp->c_cc == 0) |
| 166 | clp->c_cf = clp->c_cl = (u_char *)0; |
| 167 | splx(s); |
| 168 | return p - cp; |
| 169 | } |
| 170 | |
| 171 | /* |
| 172 | * Return count of contiguous characters in clist. |
| 173 | * Stop counting if flag&character is non-null. |
| 174 | */ |
| 175 | int |
| 176 | ndqb(struct clist *clp, int flag) |
| 177 | { |
| 178 | int count = 0; |
| 179 | int i; |
| 180 | int cc; |
| 181 | int s; |
| 182 | |
| 183 | s = spltty(); |
| 184 | if ((cc = clp->c_cc) == 0) |
| 185 | goto out; |
| 186 | |
| 187 | if (flag == 0) { |
| 188 | count = clp->c_cl - clp->c_cf; |
| 189 | if (count <= 0) |
| 190 | count = clp->c_ce - clp->c_cf; |
| 191 | goto out; |
| 192 | } |
| 193 | |
| 194 | i = clp->c_cf - clp->c_cs; |
| 195 | if (flag & TTY_QUOTE) { |
| 196 | while (cc-- > 0 && !(clp->c_cs[i++] & (flag & ~TTY_QUOTE) || |
| 197 | isset(clp->c_cq, i))) { |
| 198 | count++; |
| 199 | if (i == clp->c_cn) |
| 200 | break; |
| 201 | } |
| 202 | } else { |
| 203 | while (cc-- > 0 && !(clp->c_cs[i++] & flag)) { |
| 204 | count++; |
| 205 | if (i == clp->c_cn) |
| 206 | break; |
| 207 | } |
| 208 | } |
| 209 | out: |
| 210 | splx(s); |
| 211 | return count; |
| 212 | } |
| 213 | |
| 214 | /* |
| 215 | * Flush count bytes from clist. |
| 216 | */ |
| 217 | void |
| 218 | ndflush(struct clist *clp, int count) |
| 219 | { |
| 220 | int cc; |
| 221 | int s; |
| 222 | |
| 223 | s = spltty(); |
| 224 | if (count == clp->c_cc) { |
| 225 | clp->c_cc = 0; |
| 226 | clp->c_cf = clp->c_cl = (u_char *)0; |
| 227 | goto out; |
| 228 | } |
| 229 | /* optimize this while loop */ |
| 230 | while (count > 0 && clp->c_cc > 0) { |
| 231 | cc = clp->c_cl - clp->c_cf; |
| 232 | if (clp->c_cf >= clp->c_cl) |
| 233 | cc = clp->c_ce - clp->c_cf; |
| 234 | if (cc > count) |
| 235 | cc = count; |
| 236 | count -= cc; |
| 237 | clp->c_cc -= cc; |
| 238 | clp->c_cf += cc; |
| 239 | if (clp->c_cf == clp->c_ce) |
| 240 | clp->c_cf = clp->c_cs; |
| 241 | } |
| 242 | if (clp->c_cc == 0) |
| 243 | clp->c_cf = clp->c_cl = (u_char *)0; |
| 244 | out: |
| 245 | splx(s); |
| 246 | } |
| 247 | |
| 248 | /* |
| 249 | * Put a character into the output queue. |
| 250 | */ |
| 251 | int |
| 252 | putc(int c, struct clist *clp) |
| 253 | { |
| 254 | int i; |
| 255 | int s; |
| 256 | |
| 257 | s = spltty(); |
| 258 | if (clp->c_cc == clp->c_cn) |
| 259 | goto out; |
| 260 | |
| 261 | if (clp->c_cc == 0) { |
| 262 | if (!clp->c_cs) { |
| 263 | #if defined(DIAGNOSTIC) || 1 |
| 264 | printf("putc: required clalloc\n" ); |
| 265 | #endif |
| 266 | if (clalloc(clp, clp->c_cn, 1)) { |
| 267 | out: |
| 268 | splx(s); |
| 269 | return -1; |
| 270 | } |
| 271 | } |
| 272 | clp->c_cf = clp->c_cl = clp->c_cs; |
| 273 | } |
| 274 | |
| 275 | *clp->c_cl = c & 0xff; |
| 276 | i = clp->c_cl - clp->c_cs; |
| 277 | if (clp->c_cq) { |
| 278 | #ifdef QBITS |
| 279 | if (c & TTY_QUOTE) |
| 280 | setbit(clp->c_cq, i); |
| 281 | else |
| 282 | clrbit(clp->c_cq, i); |
| 283 | #else |
| 284 | q = clp->c_cq + i; |
| 285 | *q = (c & TTY_QUOTE) ? 1 : 0; |
| 286 | #endif |
| 287 | } |
| 288 | clp->c_cc++; |
| 289 | clp->c_cl++; |
| 290 | if (clp->c_cl == clp->c_ce) |
| 291 | clp->c_cl = clp->c_cs; |
| 292 | splx(s); |
| 293 | return 0; |
| 294 | } |
| 295 | |
| 296 | #ifdef QBITS |
| 297 | /* |
| 298 | * optimized version of |
| 299 | * |
| 300 | * for (i = 0; i < len; i++) |
| 301 | * clrbit(cp, off + len); |
| 302 | */ |
| 303 | static void |
| 304 | clrbits(u_char *cp, unsigned int off, unsigned int len) |
| 305 | { |
| 306 | unsigned int sbi, ebi; |
| 307 | u_char *scp, *ecp; |
| 308 | unsigned int end; |
| 309 | unsigned char mask; |
| 310 | |
| 311 | scp = cp + off / NBBY; |
| 312 | sbi = off % NBBY; |
| 313 | end = off + len + NBBY - 1; |
| 314 | ecp = cp + end / NBBY - 1; |
| 315 | ebi = end % NBBY + 1; |
| 316 | if (scp >= ecp) { |
| 317 | mask = ((1 << len) - 1) << sbi; |
| 318 | *scp &= ~mask; |
| 319 | } else { |
| 320 | mask = (1 << sbi) - 1; |
| 321 | *scp++ &= mask; |
| 322 | |
| 323 | mask = (1 << ebi) - 1; |
| 324 | *ecp &= ~mask; |
| 325 | |
| 326 | while (scp < ecp) |
| 327 | *scp++ = 0x00; |
| 328 | } |
| 329 | } |
| 330 | #endif |
| 331 | |
| 332 | /* |
| 333 | * Copy buffer to clist. |
| 334 | * Return number of bytes not transfered. |
| 335 | */ |
| 336 | int |
| 337 | b_to_q(const u_char *cp, int count, struct clist *clp) |
| 338 | { |
| 339 | int cc; |
| 340 | const u_char *p = cp; |
| 341 | int s; |
| 342 | |
| 343 | if (count <= 0) |
| 344 | return 0; |
| 345 | |
| 346 | s = spltty(); |
| 347 | if (clp->c_cc == clp->c_cn) |
| 348 | goto out; |
| 349 | |
| 350 | if (clp->c_cc == 0) { |
| 351 | if (!clp->c_cs) { |
| 352 | #if defined(DIAGNOSTIC) || 1 |
| 353 | printf("b_to_q: required clalloc\n" ); |
| 354 | #endif |
| 355 | if (clalloc(clp, clp->c_cn, 1)) |
| 356 | goto out; |
| 357 | } |
| 358 | clp->c_cf = clp->c_cl = clp->c_cs; |
| 359 | } |
| 360 | |
| 361 | /* optimize this while loop */ |
| 362 | while (count > 0 && clp->c_cc < clp->c_cn) { |
| 363 | cc = clp->c_ce - clp->c_cl; |
| 364 | if (clp->c_cf > clp->c_cl) |
| 365 | cc = clp->c_cf - clp->c_cl; |
| 366 | if (cc > count) |
| 367 | cc = count; |
| 368 | memcpy(clp->c_cl, p, cc); |
| 369 | if (clp->c_cq) { |
| 370 | #ifdef QBITS |
| 371 | clrbits(clp->c_cq, clp->c_cl - clp->c_cs, cc); |
| 372 | #else |
| 373 | memset(clp->c_cl - clp->c_cs + clp->c_cq, 0, cc); |
| 374 | #endif |
| 375 | } |
| 376 | p += cc; |
| 377 | count -= cc; |
| 378 | clp->c_cc += cc; |
| 379 | clp->c_cl += cc; |
| 380 | if (clp->c_cl == clp->c_ce) |
| 381 | clp->c_cl = clp->c_cs; |
| 382 | } |
| 383 | out: |
| 384 | splx(s); |
| 385 | return count; |
| 386 | } |
| 387 | |
| 388 | static int cc; |
| 389 | |
| 390 | /* |
| 391 | * Given a non-NULL pointer into the clist return the pointer |
| 392 | * to the next character in the list or return NULL if no more chars. |
| 393 | * |
| 394 | * Callers must not allow getc's to happen between firstc's and getc's |
| 395 | * so that the pointer becomes invalid. Note that interrupts are NOT |
| 396 | * masked. |
| 397 | */ |
| 398 | u_char * |
| 399 | nextc(struct clist *clp, u_char *cp, int *c) |
| 400 | { |
| 401 | |
| 402 | if (clp->c_cf == cp) { |
| 403 | /* |
| 404 | * First time initialization. |
| 405 | */ |
| 406 | cc = clp->c_cc; |
| 407 | } |
| 408 | if (cc == 0 || cp == NULL) |
| 409 | return NULL; |
| 410 | if (--cc == 0) |
| 411 | return NULL; |
| 412 | if (++cp == clp->c_ce) |
| 413 | cp = clp->c_cs; |
| 414 | *c = *cp & 0xff; |
| 415 | if (clp->c_cq) { |
| 416 | #ifdef QBITS |
| 417 | if (isset(clp->c_cq, cp - clp->c_cs)) |
| 418 | *c |= TTY_QUOTE; |
| 419 | #else |
| 420 | if (*(clp->c_cf - clp->c_cs + clp->c_cq)) |
| 421 | *c |= TTY_QUOTE; |
| 422 | #endif |
| 423 | } |
| 424 | return cp; |
| 425 | } |
| 426 | |
| 427 | /* |
| 428 | * Given a non-NULL pointer into the clist return the pointer |
| 429 | * to the first character in the list or return NULL if no more chars. |
| 430 | * |
| 431 | * Callers must not allow getc's to happen between firstc's and getc's |
| 432 | * so that the pointer becomes invalid. Note that interrupts are NOT |
| 433 | * masked. |
| 434 | * |
| 435 | * *c is set to the NEXT character |
| 436 | */ |
| 437 | u_char * |
| 438 | firstc(struct clist *clp, int *c) |
| 439 | { |
| 440 | u_char *cp; |
| 441 | |
| 442 | cc = clp->c_cc; |
| 443 | if (cc == 0) |
| 444 | return NULL; |
| 445 | cp = clp->c_cf; |
| 446 | *c = *cp & 0xff; |
| 447 | if (clp->c_cq) { |
| 448 | #ifdef QBITS |
| 449 | if (isset(clp->c_cq, cp - clp->c_cs)) |
| 450 | *c |= TTY_QUOTE; |
| 451 | #else |
| 452 | if (*(cp - clp->c_cs + clp->c_cq)) |
| 453 | *c |= TTY_QUOTE; |
| 454 | #endif |
| 455 | } |
| 456 | return clp->c_cf; |
| 457 | } |
| 458 | |
| 459 | /* |
| 460 | * Remove the last character in the clist and return it. |
| 461 | */ |
| 462 | int |
| 463 | unputc(struct clist *clp) |
| 464 | { |
| 465 | unsigned int c = -1; |
| 466 | int s; |
| 467 | |
| 468 | s = spltty(); |
| 469 | if (clp->c_cc == 0) |
| 470 | goto out; |
| 471 | |
| 472 | if (clp->c_cl == clp->c_cs) |
| 473 | clp->c_cl = clp->c_ce - 1; |
| 474 | else |
| 475 | --clp->c_cl; |
| 476 | clp->c_cc--; |
| 477 | |
| 478 | c = *clp->c_cl & 0xff; |
| 479 | if (clp->c_cq) { |
| 480 | #ifdef QBITS |
| 481 | if (isset(clp->c_cq, clp->c_cl - clp->c_cs)) |
| 482 | c |= TTY_QUOTE; |
| 483 | #else |
| 484 | if (*(clp->c_cf - clp->c_cs + clp->c_cq)) |
| 485 | c |= TTY_QUOTE; |
| 486 | #endif |
| 487 | } |
| 488 | if (clp->c_cc == 0) |
| 489 | clp->c_cf = clp->c_cl = (u_char *)0; |
| 490 | out: |
| 491 | splx(s); |
| 492 | return c; |
| 493 | } |
| 494 | |
| 495 | /* |
| 496 | * Put the chars in the from queue on the end of the to queue. |
| 497 | */ |
| 498 | void |
| 499 | catq(struct clist *from, struct clist *to) |
| 500 | { |
| 501 | int c; |
| 502 | |
| 503 | while ((c = getc(from)) != -1) |
| 504 | putc(c, to); |
| 505 | } |
| 506 | |