1 /*- 2 * Copyright (c) 2000 Poul-Henning Kamp and Dag-Erling Co�dan Sm�rgrav 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 34 #ifdef _KERNEL 35 #include <sys/ctype.h> 36 #include <sys/kernel.h> 37 #include <sys/malloc.h> 38 #include <sys/systm.h> 39 #include <sys/uio.h> 40 #include <machine/stdarg.h> 41 #else /* _KERNEL */ 42 #include <ctype.h> 43 #include <stdarg.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #endif /* _KERNEL */ 48 49 #include <sys/sbuf.h> 50 51 #ifdef _KERNEL 52 static MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers"); 53 #define SBMALLOC(size) malloc(size, M_SBUF, M_WAITOK) 54 #define SBFREE(buf) free(buf, M_SBUF) 55 #else /* _KERNEL */ 56 #define KASSERT(e, m) 57 #define SBMALLOC(size) malloc(size) 58 #define SBFREE(buf) free(buf) 59 #define min(x,y) MIN(x,y) 60 #endif /* _KERNEL */ 61 62 /* 63 * Predicates 64 */ 65 #define SBUF_ISDYNAMIC(s) ((s)->s_flags & SBUF_DYNAMIC) 66 #define SBUF_ISDYNSTRUCT(s) ((s)->s_flags & SBUF_DYNSTRUCT) 67 #define SBUF_ISFINISHED(s) ((s)->s_flags & SBUF_FINISHED) 68 #define SBUF_HASOVERFLOWED(s) ((s)->s_flags & SBUF_OVERFLOWED) 69 #define SBUF_HASROOM(s) ((s)->s_len < (s)->s_size - 1) 70 #define SBUF_FREESPACE(s) ((s)->s_size - (s)->s_len - 1) 71 #define SBUF_CANEXTEND(s) ((s)->s_flags & SBUF_AUTOEXTEND) 72 73 /* 74 * Set / clear flags 75 */ 76 #define SBUF_SETFLAG(s, f) do { (s)->s_flags |= (f); } while (0) 77 #define SBUF_CLEARFLAG(s, f) do { (s)->s_flags &= ~(f); } while (0) 78 79 #define SBUF_MINEXTENDSIZE 16 /* Should be power of 2. */ 80 #define SBUF_MAXEXTENDSIZE PAGE_SIZE 81 #define SBUF_MAXEXTENDINCR PAGE_SIZE 82 83 /* 84 * Debugging support 85 */ 86 #if defined(_KERNEL) && defined(INVARIANTS) 87 static void 88 _assert_sbuf_integrity(const char *fun, struct sbuf *s) 89 { 90 KASSERT(s != NULL, 91 ("%s called with a NULL sbuf pointer", fun)); 92 KASSERT(s->s_buf != NULL, 93 ("%s called with uninitialized or corrupt sbuf", fun)); 94 KASSERT(s->s_len < s->s_size, 95 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size)); 96 } 97 98 static void 99 _assert_sbuf_state(const char *fun, struct sbuf *s, int state) 100 { 101 KASSERT((s->s_flags & SBUF_FINISHED) == state, 102 ("%s called with %sfinished or corrupt sbuf", fun, 103 (state ? "un" : ""))); 104 } 105 #define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s)) 106 #define assert_sbuf_state(s, i) _assert_sbuf_state(__func__, (s), (i)) 107 #else /* _KERNEL && INVARIANTS */ 108 #define assert_sbuf_integrity(s) do { } while (0) 109 #define assert_sbuf_state(s, i) do { } while (0) 110 #endif /* _KERNEL && INVARIANTS */ 111 112 static int 113 sbuf_extendsize(int size) 114 { 115 int newsize; 116 117 newsize = SBUF_MINEXTENDSIZE; 118 while (newsize < size) { 119 if (newsize < (int)SBUF_MAXEXTENDSIZE) 120 newsize *= 2; 121 else 122 newsize += SBUF_MAXEXTENDINCR; 123 } 124 125 return (newsize); 126 } 127 128 129 /* 130 * Extend an sbuf. 131 */ 132 static int 133 sbuf_extend(struct sbuf *s, int addlen) 134 { 135 char *newbuf; 136 int newsize; 137 138 if (!SBUF_CANEXTEND(s)) 139 return (-1); 140 141 newsize = sbuf_extendsize(s->s_size + addlen); 142 newbuf = (char *)SBMALLOC(newsize); 143 if (newbuf == NULL) 144 return (-1); 145 bcopy(s->s_buf, newbuf, s->s_size); 146 if (SBUF_ISDYNAMIC(s)) 147 SBFREE(s->s_buf); 148 else 149 SBUF_SETFLAG(s, SBUF_DYNAMIC); 150 s->s_buf = newbuf; 151 s->s_size = newsize; 152 return (0); 153 } 154 155 /* 156 * Initialize an sbuf. 157 * If buf is non-NULL, it points to a static or already-allocated string 158 * big enough to hold at least length characters. 159 */ 160 struct sbuf * 161 sbuf_new(struct sbuf *s, char *buf, int length, int flags) 162 { 163 KASSERT(length >= 0, 164 ("attempt to create an sbuf of negative length (%d)", length)); 165 KASSERT((flags & ~SBUF_USRFLAGMSK) == 0, 166 ("%s called with invalid flags", __func__)); 167 168 flags &= SBUF_USRFLAGMSK; 169 if (s == NULL) { 170 s = (struct sbuf *)SBMALLOC(sizeof *s); 171 if (s == NULL) 172 return (NULL); 173 bzero(s, sizeof *s); 174 s->s_flags = flags; 175 SBUF_SETFLAG(s, SBUF_DYNSTRUCT); 176 } else { 177 bzero(s, sizeof *s); 178 s->s_flags = flags; 179 } 180 s->s_size = length; 181 if (buf) { 182 s->s_buf = buf; 183 return (s); 184 } 185 if (flags & SBUF_AUTOEXTEND) 186 s->s_size = sbuf_extendsize(s->s_size); 187 s->s_buf = (char *)SBMALLOC(s->s_size); 188 if (s->s_buf == NULL) { 189 if (SBUF_ISDYNSTRUCT(s)) 190 SBFREE(s); 191 return (NULL); 192 } 193 SBUF_SETFLAG(s, SBUF_DYNAMIC); 194 return (s); 195 } 196 197 #ifdef _KERNEL 198 /* 199 * Create an sbuf with uio data 200 */ 201 struct sbuf * 202 sbuf_uionew(struct sbuf *s, struct uio *uio, int *error) 203 { 204 KASSERT(uio != NULL, 205 ("%s called with NULL uio pointer", __func__)); 206 KASSERT(error != NULL, 207 ("%s called with NULL error pointer", __func__)); 208 209 s = sbuf_new(s, NULL, uio->uio_resid + 1, 0); 210 if (s == NULL) { 211 *error = ENOMEM; 212 return (NULL); 213 } 214 *error = uiomove(s->s_buf, uio->uio_resid, uio); 215 if (*error != 0) { 216 sbuf_delete(s); 217 return (NULL); 218 } 219 s->s_len = s->s_size - 1; 220 *error = 0; 221 return (s); 222 } 223 #endif 224 225 /* 226 * Clear an sbuf and reset its position. 227 */ 228 void 229 sbuf_clear(struct sbuf *s) 230 { 231 assert_sbuf_integrity(s); 232 /* don't care if it's finished or not */ 233 234 SBUF_CLEARFLAG(s, SBUF_FINISHED); 235 SBUF_CLEARFLAG(s, SBUF_OVERFLOWED); 236 s->s_len = 0; 237 } 238 239 /* 240 * Set the sbuf's end position to an arbitrary value. 241 * Effectively truncates the sbuf at the new position. 242 */ 243 int 244 sbuf_setpos(struct sbuf *s, int pos) 245 { 246 assert_sbuf_integrity(s); 247 assert_sbuf_state(s, 0); 248 249 KASSERT(pos >= 0, 250 ("attempt to seek to a negative position (%d)", pos)); 251 KASSERT(pos < s->s_size, 252 ("attempt to seek past end of sbuf (%d >= %d)", pos, s->s_size)); 253 254 if (pos < 0 || pos > s->s_len) 255 return (-1); 256 s->s_len = pos; 257 return (0); 258 } 259 260 /* 261 * Append a byte string to an sbuf. 262 */ 263 int 264 sbuf_bcat(struct sbuf *s, const void *buf, size_t len) 265 { 266 const char *str = buf; 267 268 assert_sbuf_integrity(s); 269 assert_sbuf_state(s, 0); 270 271 if (SBUF_HASOVERFLOWED(s)) 272 return (-1); 273 274 for (; len; len--) { 275 if (!SBUF_HASROOM(s) && sbuf_extend(s, len) < 0) 276 break; 277 s->s_buf[s->s_len++] = *str++; 278 } 279 if (len) { 280 SBUF_SETFLAG(s, SBUF_OVERFLOWED); 281 return (-1); 282 } 283 return (0); 284 } 285 286 #ifdef _KERNEL 287 /* 288 * Copy a byte string from userland into an sbuf. 289 */ 290 int 291 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len) 292 { 293 assert_sbuf_integrity(s); 294 assert_sbuf_state(s, 0); 295 296 if (SBUF_HASOVERFLOWED(s)) 297 return (-1); 298 299 if (len == 0) 300 return (0); 301 if (len > SBUF_FREESPACE(s)) { 302 sbuf_extend(s, len - SBUF_FREESPACE(s)); 303 len = min(len, SBUF_FREESPACE(s)); 304 } 305 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0) 306 return (-1); 307 s->s_len += len; 308 309 return (0); 310 } 311 #endif 312 313 /* 314 * Copy a byte string into an sbuf. 315 */ 316 int 317 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len) 318 { 319 assert_sbuf_integrity(s); 320 assert_sbuf_state(s, 0); 321 322 sbuf_clear(s); 323 return (sbuf_bcat(s, buf, len)); 324 } 325 326 /* 327 * Append a string to an sbuf. 328 */ 329 int 330 sbuf_cat(struct sbuf *s, const char *str) 331 { 332 assert_sbuf_integrity(s); 333 assert_sbuf_state(s, 0); 334 335 if (SBUF_HASOVERFLOWED(s)) 336 return (-1); 337 338 while (*str) { 339 if (!SBUF_HASROOM(s) && sbuf_extend(s, strlen(str)) < 0) 340 break; 341 s->s_buf[s->s_len++] = *str++; 342 } 343 if (*str) { 344 SBUF_SETFLAG(s, SBUF_OVERFLOWED); 345 return (-1); 346 } 347 return (0); 348 } 349 350 #ifdef _KERNEL 351 /* 352 * Append a string from userland to an sbuf. 353 */ 354 int 355 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len) 356 { 357 size_t done; 358 359 assert_sbuf_integrity(s); 360 assert_sbuf_state(s, 0); 361 362 if (SBUF_HASOVERFLOWED(s)) 363 return (-1); 364 365 if (len == 0) 366 len = SBUF_FREESPACE(s); /* XXX return 0? */ 367 if (len > SBUF_FREESPACE(s)) { 368 sbuf_extend(s, len); 369 len = min(len, SBUF_FREESPACE(s)); 370 } 371 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) { 372 case ENAMETOOLONG: 373 SBUF_SETFLAG(s, SBUF_OVERFLOWED); 374 /* fall through */ 375 case 0: 376 s->s_len += done - 1; 377 break; 378 default: 379 return (-1); /* XXX */ 380 } 381 382 return (done); 383 } 384 #endif 385 386 /* 387 * Copy a string into an sbuf. 388 */ 389 int 390 sbuf_cpy(struct sbuf *s, const char *str) 391 { 392 assert_sbuf_integrity(s); 393 assert_sbuf_state(s, 0); 394 395 sbuf_clear(s); 396 return (sbuf_cat(s, str)); 397 } 398 399 /* 400 * Format the given argument list and append the resulting string to an sbuf. 401 */ 402 int 403 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap) 404 { 405 va_list ap_copy; 406 int len; 407 408 assert_sbuf_integrity(s); 409 assert_sbuf_state(s, 0); 410 411 KASSERT(fmt != NULL, 412 ("%s called with a NULL format string", __func__)); 413 414 if (SBUF_HASOVERFLOWED(s)) 415 return (-1); 416 417 do { 418 va_copy(ap_copy, ap); 419 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1, 420 fmt, ap_copy); 421 va_end(ap_copy); 422 } while (len > SBUF_FREESPACE(s) && 423 sbuf_extend(s, len - SBUF_FREESPACE(s)) == 0); 424 425 /* 426 * s->s_len is the length of the string, without the terminating nul. 427 * When updating s->s_len, we must subtract 1 from the length that 428 * we passed into vsnprintf() because that length includes the 429 * terminating nul. 430 * 431 * vsnprintf() returns the amount that would have been copied, 432 * given sufficient space, hence the min() calculation below. 433 */ 434 s->s_len += min(len, SBUF_FREESPACE(s)); 435 if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s)) 436 SBUF_SETFLAG(s, SBUF_OVERFLOWED); 437 438 KASSERT(s->s_len < s->s_size, 439 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size)); 440 441 if (SBUF_HASOVERFLOWED(s)) 442 return (-1); 443 return (0); 444 } 445 446 /* 447 * Format the given arguments and append the resulting string to an sbuf. 448 */ 449 int 450 sbuf_printf(struct sbuf *s, const char *fmt, ...) 451 { 452 va_list ap; 453 int result; 454 455 va_start(ap, fmt); 456 result = sbuf_vprintf(s, fmt, ap); 457 va_end(ap); 458 return(result); 459 } 460 461 /* 462 * Append a character to an sbuf. 463 */ 464 int 465 sbuf_putc(struct sbuf *s, int c) 466 { 467 assert_sbuf_integrity(s); 468 assert_sbuf_state(s, 0); 469 470 if (SBUF_HASOVERFLOWED(s)) 471 return (-1); 472 473 if (!SBUF_HASROOM(s) && sbuf_extend(s, 1) < 0) { 474 SBUF_SETFLAG(s, SBUF_OVERFLOWED); 475 return (-1); 476 } 477 if (c != '\0') 478 s->s_buf[s->s_len++] = c; 479 return (0); 480 } 481 482 /* 483 * Trim whitespace characters from end of an sbuf. 484 */ 485 int 486 sbuf_trim(struct sbuf *s) 487 { 488 assert_sbuf_integrity(s); 489 assert_sbuf_state(s, 0); 490 491 if (SBUF_HASOVERFLOWED(s)) 492 return (-1); 493 494 while (s->s_len && isspace(s->s_buf[s->s_len-1])) 495 --s->s_len; 496 497 return (0); 498 } 499 500 /* 501 * Check if an sbuf overflowed 502 */ 503 int 504 sbuf_overflowed(struct sbuf *s) 505 { 506 return SBUF_HASOVERFLOWED(s); 507 } 508 509 /* 510 * Finish off an sbuf. 511 */ 512 void 513 sbuf_finish(struct sbuf *s) 514 { 515 assert_sbuf_integrity(s); 516 assert_sbuf_state(s, 0); 517 518 s->s_buf[s->s_len] = '\0'; 519 SBUF_CLEARFLAG(s, SBUF_OVERFLOWED); 520 SBUF_SETFLAG(s, SBUF_FINISHED); 521 } 522 523 /* 524 * Return a pointer to the sbuf data. 525 */ 526 char * 527 sbuf_data(struct sbuf *s) 528 { 529 assert_sbuf_integrity(s); 530 assert_sbuf_state(s, SBUF_FINISHED); 531 532 return s->s_buf; 533 } 534 535 /* 536 * Return the length of the sbuf data. 537 */ 538 int 539 sbuf_len(struct sbuf *s) 540 { 541 assert_sbuf_integrity(s); 542 /* don't care if it's finished or not */ 543 544 if (SBUF_HASOVERFLOWED(s)) 545 return (-1); 546 return s->s_len; 547 } 548 549 /* 550 * Clear an sbuf, free its buffer if necessary. 551 */ 552 void 553 sbuf_delete(struct sbuf *s) 554 { 555 int isdyn; 556 557 assert_sbuf_integrity(s); 558 /* don't care if it's finished or not */ 559 560 if (SBUF_ISDYNAMIC(s)) 561 SBFREE(s->s_buf); 562 isdyn = SBUF_ISDYNSTRUCT(s); 563 bzero(s, sizeof *s); 564 if (isdyn) 565 SBFREE(s); 566 } 567 568 /* 569 * Check if an sbuf has been finished. 570 */ 571 int 572 sbuf_done(struct sbuf *s) 573 { 574 575 return(SBUF_ISFINISHED(s)); 576 } 577