subr_sbuf.c revision 116182
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: head/sys/kern/subr_sbuf.c 116182 2003-06-11 00:56:59Z obrien $"); 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 52MALLOC_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) 87static 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 98static 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 112static int 113sbuf_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 */ 132static int 133sbuf_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 */ 160struct sbuf * 161sbuf_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 */ 201struct sbuf * 202sbuf_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 */ 228void 229sbuf_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 */ 243int 244sbuf_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 */ 263int 264sbuf_bcat(struct sbuf *s, const char *str, size_t len) 265{ 266 assert_sbuf_integrity(s); 267 assert_sbuf_state(s, 0); 268 269 if (SBUF_HASOVERFLOWED(s)) 270 return (-1); 271 272 for (; len; len--) { 273 if (!SBUF_HASROOM(s) && sbuf_extend(s, len) < 0) 274 break; 275 s->s_buf[s->s_len++] = *str++; 276 } 277 if (len) { 278 SBUF_SETFLAG(s, SBUF_OVERFLOWED); 279 return (-1); 280 } 281 return (0); 282} 283 284#ifdef _KERNEL 285/* 286 * Copy a byte string from userland into an sbuf. 287 */ 288int 289sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len) 290{ 291 assert_sbuf_integrity(s); 292 assert_sbuf_state(s, 0); 293 294 if (SBUF_HASOVERFLOWED(s)) 295 return (-1); 296 297 if (len == 0) 298 return (0); 299 if (len > SBUF_FREESPACE(s)) { 300 sbuf_extend(s, len - SBUF_FREESPACE(s)); 301 len = min(len, SBUF_FREESPACE(s)); 302 } 303 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0) 304 return (-1); 305 s->s_len += len; 306 307 return (0); 308} 309#endif 310 311/* 312 * Copy a byte string into an sbuf. 313 */ 314int 315sbuf_bcpy(struct sbuf *s, const char *str, size_t len) 316{ 317 assert_sbuf_integrity(s); 318 assert_sbuf_state(s, 0); 319 320 sbuf_clear(s); 321 return (sbuf_bcat(s, str, len)); 322} 323 324/* 325 * Append a string to an sbuf. 326 */ 327int 328sbuf_cat(struct sbuf *s, const char *str) 329{ 330 assert_sbuf_integrity(s); 331 assert_sbuf_state(s, 0); 332 333 if (SBUF_HASOVERFLOWED(s)) 334 return (-1); 335 336 while (*str) { 337 if (!SBUF_HASROOM(s) && sbuf_extend(s, strlen(str)) < 0) 338 break; 339 s->s_buf[s->s_len++] = *str++; 340 } 341 if (*str) { 342 SBUF_SETFLAG(s, SBUF_OVERFLOWED); 343 return (-1); 344 } 345 return (0); 346} 347 348#ifdef _KERNEL 349/* 350 * Append a string from userland to an sbuf. 351 */ 352int 353sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len) 354{ 355 size_t done; 356 357 assert_sbuf_integrity(s); 358 assert_sbuf_state(s, 0); 359 360 if (SBUF_HASOVERFLOWED(s)) 361 return (-1); 362 363 if (len == 0) 364 len = SBUF_FREESPACE(s); /* XXX return 0? */ 365 if (len > SBUF_FREESPACE(s)) { 366 sbuf_extend(s, len); 367 len = min(len, SBUF_FREESPACE(s)); 368 } 369 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) { 370 case ENAMETOOLONG: 371 SBUF_SETFLAG(s, SBUF_OVERFLOWED); 372 /* fall through */ 373 case 0: 374 s->s_len += done - 1; 375 break; 376 default: 377 return (-1); /* XXX */ 378 } 379 380 return (0); 381} 382#endif 383 384/* 385 * Copy a string into an sbuf. 386 */ 387int 388sbuf_cpy(struct sbuf *s, const char *str) 389{ 390 assert_sbuf_integrity(s); 391 assert_sbuf_state(s, 0); 392 393 sbuf_clear(s); 394 return (sbuf_cat(s, str)); 395} 396 397/* 398 * Format the given argument list and append the resulting string to an sbuf. 399 */ 400int 401sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap) 402{ 403 va_list ap_copy; 404 int len; 405 406 assert_sbuf_integrity(s); 407 assert_sbuf_state(s, 0); 408 409 KASSERT(fmt != NULL, 410 ("%s called with a NULL format string", __func__)); 411 412 if (SBUF_HASOVERFLOWED(s)) 413 return (-1); 414 415 do { 416 va_copy(ap_copy, ap); 417 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1, 418 fmt, ap_copy); 419 va_end(ap_copy); 420 } while (len > SBUF_FREESPACE(s) && 421 sbuf_extend(s, len - SBUF_FREESPACE(s)) == 0); 422 423 /* 424 * s->s_len is the length of the string, without the terminating nul. 425 * When updating s->s_len, we must subtract 1 from the length that 426 * we passed into vsnprintf() because that length includes the 427 * terminating nul. 428 * 429 * vsnprintf() returns the amount that would have been copied, 430 * given sufficient space, hence the min() calculation below. 431 */ 432 s->s_len += min(len, SBUF_FREESPACE(s)); 433 if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s)) 434 SBUF_SETFLAG(s, SBUF_OVERFLOWED); 435 436 KASSERT(s->s_len < s->s_size, 437 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size)); 438 439 if (SBUF_HASOVERFLOWED(s)) 440 return (-1); 441 return (0); 442} 443 444/* 445 * Format the given arguments and append the resulting string to an sbuf. 446 */ 447int 448sbuf_printf(struct sbuf *s, const char *fmt, ...) 449{ 450 va_list ap; 451 int result; 452 453 va_start(ap, fmt); 454 result = sbuf_vprintf(s, fmt, ap); 455 va_end(ap); 456 return(result); 457} 458 459/* 460 * Append a character to an sbuf. 461 */ 462int 463sbuf_putc(struct sbuf *s, int c) 464{ 465 assert_sbuf_integrity(s); 466 assert_sbuf_state(s, 0); 467 468 if (SBUF_HASOVERFLOWED(s)) 469 return (-1); 470 471 if (!SBUF_HASROOM(s) && sbuf_extend(s, 1) < 0) { 472 SBUF_SETFLAG(s, SBUF_OVERFLOWED); 473 return (-1); 474 } 475 if (c != '\0') 476 s->s_buf[s->s_len++] = c; 477 return (0); 478} 479 480/* 481 * Trim whitespace characters from end of an sbuf. 482 */ 483int 484sbuf_trim(struct sbuf *s) 485{ 486 assert_sbuf_integrity(s); 487 assert_sbuf_state(s, 0); 488 489 if (SBUF_HASOVERFLOWED(s)) 490 return (-1); 491 492 while (s->s_len && isspace(s->s_buf[s->s_len-1])) 493 --s->s_len; 494 495 return (0); 496} 497 498/* 499 * Check if an sbuf overflowed 500 */ 501int 502sbuf_overflowed(struct sbuf *s) 503{ 504 return SBUF_HASOVERFLOWED(s); 505} 506 507/* 508 * Finish off an sbuf. 509 */ 510void 511sbuf_finish(struct sbuf *s) 512{ 513 assert_sbuf_integrity(s); 514 assert_sbuf_state(s, 0); 515 516 s->s_buf[s->s_len] = '\0'; 517 SBUF_CLEARFLAG(s, SBUF_OVERFLOWED); 518 SBUF_SETFLAG(s, SBUF_FINISHED); 519} 520 521/* 522 * Return a pointer to the sbuf data. 523 */ 524char * 525sbuf_data(struct sbuf *s) 526{ 527 assert_sbuf_integrity(s); 528 assert_sbuf_state(s, SBUF_FINISHED); 529 530 return s->s_buf; 531} 532 533/* 534 * Return the length of the sbuf data. 535 */ 536int 537sbuf_len(struct sbuf *s) 538{ 539 assert_sbuf_integrity(s); 540 /* don't care if it's finished or not */ 541 542 if (SBUF_HASOVERFLOWED(s)) 543 return (-1); 544 return s->s_len; 545} 546 547/* 548 * Clear an sbuf, free its buffer if necessary. 549 */ 550void 551sbuf_delete(struct sbuf *s) 552{ 553 int isdyn; 554 555 assert_sbuf_integrity(s); 556 /* don't care if it's finished or not */ 557 558 if (SBUF_ISDYNAMIC(s)) 559 SBFREE(s->s_buf); 560 isdyn = SBUF_ISDYNSTRUCT(s); 561 bzero(s, sizeof *s); 562 if (isdyn) 563 SBFREE(s); 564} 565 566/* 567 * Check if an sbuf has been finished. 568 */ 569int 570sbuf_done(struct sbuf *s) 571{ 572 573 return(SBUF_ISFINISHED(s)); 574} 575