1 /*- 2 * Copyright (c) 2000-2008 Poul-Henning Kamp 3 * Copyright (c) 2000-2008 Dag-Erling Coïdan Smørgrav 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer 11 * in this position and unchanged. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * 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/errno.h> 37 #include <sys/kernel.h> 38 #include <sys/malloc.h> 39 #include <sys/systm.h> 40 #include <sys/uio.h> 41 #include <machine/stdarg.h> 42 #else /* _KERNEL */ 43 #include <ctype.h> 44 #include <errno.h> 45 #include <stdarg.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #endif /* _KERNEL */ 50 51 #include <sys/sbuf.h> 52 53 #ifdef _KERNEL 54 static MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers"); 55 #define SBMALLOC(size) malloc(size, M_SBUF, M_WAITOK|M_ZERO) 56 #define SBFREE(buf) free(buf, M_SBUF) 57 #else /* _KERNEL */ 58 #define KASSERT(e, m) 59 #define SBMALLOC(size) calloc(1, size) 60 #define SBFREE(buf) free(buf) 61 #endif /* _KERNEL */ 62 63 /* 64 * Predicates 65 */ 66 #define SBUF_ISDYNAMIC(s) ((s)->s_flags & SBUF_DYNAMIC) 67 #define SBUF_ISDYNSTRUCT(s) ((s)->s_flags & SBUF_DYNSTRUCT) 68 #define SBUF_ISFINISHED(s) ((s)->s_flags & SBUF_FINISHED) 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 #define SBUF_ISSECTION(s) ((s)->s_flags & SBUF_INSECTION) 73 74 /* 75 * Set / clear flags 76 */ 77 #define SBUF_SETFLAG(s, f) do { (s)->s_flags |= (f); } while (0) 78 #define SBUF_CLEARFLAG(s, f) do { (s)->s_flags &= ~(f); } while (0) 79 80 #define SBUF_MINEXTENDSIZE 16 /* Should be power of 2. */ 81 82 #ifdef PAGE_SIZE 83 #define SBUF_MAXEXTENDSIZE PAGE_SIZE 84 #define SBUF_MAXEXTENDINCR PAGE_SIZE 85 #else 86 #define SBUF_MAXEXTENDSIZE 4096 87 #define SBUF_MAXEXTENDINCR 4096 88 #endif 89 90 /* 91 * Debugging support 92 */ 93 #if defined(_KERNEL) && defined(INVARIANTS) 94 95 static void 96 _assert_sbuf_integrity(const char *fun, struct sbuf *s) 97 { 98 99 KASSERT(s != NULL, 100 ("%s called with a NULL sbuf pointer", fun)); 101 KASSERT(s->s_buf != NULL, 102 ("%s called with uninitialized or corrupt sbuf", fun)); 103 KASSERT(s->s_len < s->s_size, 104 ("wrote past end of sbuf (%jd >= %jd)", 105 (intmax_t)s->s_len, (intmax_t)s->s_size)); 106 } 107 108 static void 109 _assert_sbuf_state(const char *fun, struct sbuf *s, int state) 110 { 111 112 KASSERT((s->s_flags & SBUF_FINISHED) == state, 113 ("%s called with %sfinished or corrupt sbuf", fun, 114 (state ? "un" : ""))); 115 } 116 117 #define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s)) 118 #define assert_sbuf_state(s, i) _assert_sbuf_state(__func__, (s), (i)) 119 120 #else /* _KERNEL && INVARIANTS */ 121 122 #define assert_sbuf_integrity(s) do { } while (0) 123 #define assert_sbuf_state(s, i) do { } while (0) 124 125 #endif /* _KERNEL && INVARIANTS */ 126 127 #ifdef CTASSERT 128 CTASSERT(powerof2(SBUF_MAXEXTENDSIZE)); 129 CTASSERT(powerof2(SBUF_MAXEXTENDINCR)); 130 #endif 131 132 static int 133 sbuf_extendsize(int size) 134 { 135 int newsize; 136 137 if (size < (int)SBUF_MAXEXTENDSIZE) { 138 newsize = SBUF_MINEXTENDSIZE; 139 while (newsize < size) 140 newsize *= 2; 141 } else { 142 newsize = roundup2(size, SBUF_MAXEXTENDINCR); 143 } 144 KASSERT(newsize >= size, ("%s: %d < %d\n", __func__, newsize, size)); 145 return (newsize); 146 } 147 148 /* 149 * Extend an sbuf. 150 */ 151 static int 152 sbuf_extend(struct sbuf *s, int addlen) 153 { 154 char *newbuf; 155 int newsize; 156 157 if (!SBUF_CANEXTEND(s)) 158 return (-1); 159 newsize = sbuf_extendsize(s->s_size + addlen); 160 newbuf = SBMALLOC(newsize); 161 if (newbuf == NULL) 162 return (-1); 163 memcpy(newbuf, s->s_buf, s->s_size); 164 if (SBUF_ISDYNAMIC(s)) 165 SBFREE(s->s_buf); 166 else 167 SBUF_SETFLAG(s, SBUF_DYNAMIC); 168 s->s_buf = newbuf; 169 s->s_size = newsize; 170 return (0); 171 } 172 173 /* 174 * Initialize the internals of an sbuf. 175 * If buf is non-NULL, it points to a static or already-allocated string 176 * big enough to hold at least length characters. 177 */ 178 static struct sbuf * 179 sbuf_newbuf(struct sbuf *s, char *buf, int length, int flags) 180 { 181 182 memset(s, 0, sizeof(*s)); 183 s->s_flags = flags; 184 s->s_size = length; 185 s->s_buf = buf; 186 187 if ((s->s_flags & SBUF_AUTOEXTEND) == 0) { 188 KASSERT(s->s_size >= 0, 189 ("attempt to create a too small sbuf")); 190 } 191 192 if (s->s_buf != NULL) 193 return (s); 194 195 if ((flags & SBUF_AUTOEXTEND) != 0) 196 s->s_size = sbuf_extendsize(s->s_size); 197 198 s->s_buf = SBMALLOC(s->s_size); 199 if (s->s_buf == NULL) 200 return (NULL); 201 SBUF_SETFLAG(s, SBUF_DYNAMIC); 202 return (s); 203 } 204 205 /* 206 * Initialize an sbuf. 207 * If buf is non-NULL, it points to a static or already-allocated string 208 * big enough to hold at least length characters. 209 */ 210 struct sbuf * 211 sbuf_new(struct sbuf *s, char *buf, int length, int flags) 212 { 213 214 KASSERT(length >= 0, 215 ("attempt to create an sbuf of negative length (%d)", length)); 216 KASSERT((flags & ~SBUF_USRFLAGMSK) == 0, 217 ("%s called with invalid flags", __func__)); 218 219 flags &= SBUF_USRFLAGMSK; 220 if (s != NULL) 221 return (sbuf_newbuf(s, buf, length, flags)); 222 223 s = SBMALLOC(sizeof(*s)); 224 if (s == NULL) 225 return (NULL); 226 if (sbuf_newbuf(s, buf, length, flags) == NULL) { 227 SBFREE(s); 228 return (NULL); 229 } 230 SBUF_SETFLAG(s, SBUF_DYNSTRUCT); 231 return (s); 232 } 233 234 #ifdef _KERNEL 235 /* 236 * Create an sbuf with uio data 237 */ 238 struct sbuf * 239 sbuf_uionew(struct sbuf *s, struct uio *uio, int *error) 240 { 241 242 KASSERT(uio != NULL, 243 ("%s called with NULL uio pointer", __func__)); 244 KASSERT(error != NULL, 245 ("%s called with NULL error pointer", __func__)); 246 247 s = sbuf_new(s, NULL, uio->uio_resid + 1, 0); 248 if (s == NULL) { 249 *error = ENOMEM; 250 return (NULL); 251 } 252 *error = uiomove(s->s_buf, uio->uio_resid, uio); 253 if (*error != 0) { 254 sbuf_delete(s); 255 return (NULL); 256 } 257 s->s_len = s->s_size - 1; 258 if (SBUF_ISSECTION(s)) 259 s->s_sect_len = s->s_size - 1; 260 *error = 0; 261 return (s); 262 } 263 #endif 264 265 int 266 sbuf_get_flags(struct sbuf *s) 267 { 268 269 return (s->s_flags & SBUF_USRFLAGMSK); 270 } 271 272 void 273 sbuf_clear_flags(struct sbuf *s, int flags) 274 { 275 276 s->s_flags &= ~(flags & SBUF_USRFLAGMSK); 277 } 278 279 void 280 sbuf_set_flags(struct sbuf *s, int flags) 281 { 282 283 284 s->s_flags |= (flags & SBUF_USRFLAGMSK); 285 } 286 287 /* 288 * Clear an sbuf and reset its position. 289 */ 290 void 291 sbuf_clear(struct sbuf *s) 292 { 293 294 assert_sbuf_integrity(s); 295 /* don't care if it's finished or not */ 296 297 SBUF_CLEARFLAG(s, SBUF_FINISHED); 298 s->s_error = 0; 299 s->s_len = 0; 300 s->s_sect_len = 0; 301 } 302 303 /* 304 * Set the sbuf's end position to an arbitrary value. 305 * Effectively truncates the sbuf at the new position. 306 */ 307 int 308 sbuf_setpos(struct sbuf *s, ssize_t pos) 309 { 310 311 assert_sbuf_integrity(s); 312 assert_sbuf_state(s, 0); 313 314 KASSERT(pos >= 0, 315 ("attempt to seek to a negative position (%jd)", (intmax_t)pos)); 316 KASSERT(pos < s->s_size, 317 ("attempt to seek past end of sbuf (%jd >= %jd)", 318 (intmax_t)pos, (intmax_t)s->s_size)); 319 KASSERT(!SBUF_ISSECTION(s), 320 ("attempt to seek when in a section")); 321 322 if (pos < 0 || pos > s->s_len) 323 return (-1); 324 s->s_len = pos; 325 return (0); 326 } 327 328 /* 329 * Set up a drain function and argument on an sbuf to flush data to 330 * when the sbuf buffer overflows. 331 */ 332 void 333 sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx) 334 { 335 336 assert_sbuf_state(s, 0); 337 assert_sbuf_integrity(s); 338 KASSERT(func == s->s_drain_func || s->s_len == 0, 339 ("Cannot change drain to %p on non-empty sbuf %p", func, s)); 340 s->s_drain_func = func; 341 s->s_drain_arg = ctx; 342 } 343 344 /* 345 * Call the drain and process the return. 346 */ 347 static int 348 sbuf_drain(struct sbuf *s) 349 { 350 int len; 351 352 KASSERT(s->s_len > 0, ("Shouldn't drain empty sbuf %p", s)); 353 KASSERT(s->s_error == 0, ("Called %s with error on %p", __func__, s)); 354 len = s->s_drain_func(s->s_drain_arg, s->s_buf, s->s_len); 355 if (len < 0) { 356 s->s_error = -len; 357 return (s->s_error); 358 } 359 KASSERT(len > 0 && len <= s->s_len, 360 ("Bad drain amount %d for sbuf %p", len, s)); 361 s->s_len -= len; 362 /* 363 * Fast path for the expected case where all the data was 364 * drained. 365 */ 366 if (s->s_len == 0) 367 return (0); 368 /* 369 * Move the remaining characters to the beginning of the 370 * string. 371 */ 372 memmove(s->s_buf, s->s_buf + len, s->s_len); 373 return (0); 374 } 375 376 /* 377 * Append a byte to an sbuf. This is the core function for appending 378 * to an sbuf and is the main place that deals with extending the 379 * buffer and marking overflow. 380 */ 381 static void 382 sbuf_put_byte(struct sbuf *s, int c) 383 { 384 385 assert_sbuf_integrity(s); 386 assert_sbuf_state(s, 0); 387 388 if (s->s_error != 0) 389 return; 390 if (SBUF_FREESPACE(s) <= 0) { 391 /* 392 * If there is a drain, use it, otherwise extend the 393 * buffer. 394 */ 395 if (s->s_drain_func != NULL) 396 (void)sbuf_drain(s); 397 else if (sbuf_extend(s, 1) < 0) 398 s->s_error = ENOMEM; 399 if (s->s_error != 0) 400 return; 401 } 402 s->s_buf[s->s_len++] = c; 403 if (SBUF_ISSECTION(s)) 404 s->s_sect_len++; 405 } 406 407 /* 408 * Append a byte string to an sbuf. 409 */ 410 int 411 sbuf_bcat(struct sbuf *s, const void *buf, size_t len) 412 { 413 const char *str = buf; 414 const char *end = str + len; 415 416 assert_sbuf_integrity(s); 417 assert_sbuf_state(s, 0); 418 419 if (s->s_error != 0) 420 return (-1); 421 for (; str < end; str++) { 422 sbuf_put_byte(s, *str); 423 if (s->s_error != 0) 424 return (-1); 425 } 426 return (0); 427 } 428 429 #ifdef _KERNEL 430 /* 431 * Copy a byte string from userland into an sbuf. 432 */ 433 int 434 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len) 435 { 436 437 assert_sbuf_integrity(s); 438 assert_sbuf_state(s, 0); 439 KASSERT(s->s_drain_func == NULL, 440 ("Nonsensical copyin to sbuf %p with a drain", s)); 441 442 if (s->s_error != 0) 443 return (-1); 444 if (len == 0) 445 return (0); 446 if (len > SBUF_FREESPACE(s)) { 447 sbuf_extend(s, len - SBUF_FREESPACE(s)); 448 if (SBUF_FREESPACE(s) < len) 449 len = SBUF_FREESPACE(s); 450 } 451 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0) 452 return (-1); 453 s->s_len += len; 454 455 return (0); 456 } 457 #endif 458 459 /* 460 * Copy a byte string into an sbuf. 461 */ 462 int 463 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len) 464 { 465 466 assert_sbuf_integrity(s); 467 assert_sbuf_state(s, 0); 468 469 sbuf_clear(s); 470 return (sbuf_bcat(s, buf, len)); 471 } 472 473 /* 474 * Append a string to an sbuf. 475 */ 476 int 477 sbuf_cat(struct sbuf *s, const char *str) 478 { 479 480 assert_sbuf_integrity(s); 481 assert_sbuf_state(s, 0); 482 483 if (s->s_error != 0) 484 return (-1); 485 486 while (*str != '\0') { 487 sbuf_put_byte(s, *str++); 488 if (s->s_error != 0) 489 return (-1); 490 } 491 return (0); 492 } 493 494 #ifdef _KERNEL 495 /* 496 * Append a string from userland to an sbuf. 497 */ 498 int 499 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len) 500 { 501 size_t done; 502 503 assert_sbuf_integrity(s); 504 assert_sbuf_state(s, 0); 505 KASSERT(s->s_drain_func == NULL, 506 ("Nonsensical copyin to sbuf %p with a drain", s)); 507 508 if (s->s_error != 0) 509 return (-1); 510 511 if (len == 0) 512 len = SBUF_FREESPACE(s); /* XXX return 0? */ 513 if (len > SBUF_FREESPACE(s)) { 514 sbuf_extend(s, len); 515 if (SBUF_FREESPACE(s) < len) 516 len = SBUF_FREESPACE(s); 517 } 518 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) { 519 case ENAMETOOLONG: 520 s->s_error = ENOMEM; 521 /* fall through */ 522 case 0: 523 s->s_len += done - 1; 524 if (SBUF_ISSECTION(s)) 525 s->s_sect_len += done - 1; 526 break; 527 default: 528 return (-1); /* XXX */ 529 } 530 531 return (done); 532 } 533 #endif 534 535 /* 536 * Copy a string into an sbuf. 537 */ 538 int 539 sbuf_cpy(struct sbuf *s, const char *str) 540 { 541 542 assert_sbuf_integrity(s); 543 assert_sbuf_state(s, 0); 544 545 sbuf_clear(s); 546 return (sbuf_cat(s, str)); 547 } 548 549 /* 550 * Format the given argument list and append the resulting string to an sbuf. 551 */ 552 #ifdef _KERNEL 553 554 /* 555 * Append a non-NUL character to an sbuf. This prototype signature is 556 * suitable for use with kvprintf(9). 557 */ 558 static void 559 sbuf_putc_func(int c, void *arg) 560 { 561 562 if (c != '\0') 563 sbuf_put_byte(arg, c); 564 } 565 566 int 567 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap) 568 { 569 570 assert_sbuf_integrity(s); 571 assert_sbuf_state(s, 0); 572 573 KASSERT(fmt != NULL, 574 ("%s called with a NULL format string", __func__)); 575 576 (void)kvprintf(fmt, sbuf_putc_func, s, 10, ap); 577 if (s->s_error != 0) 578 return (-1); 579 return (0); 580 } 581 #else /* !_KERNEL */ 582 int 583 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap) 584 { 585 va_list ap_copy; 586 int error, len; 587 588 assert_sbuf_integrity(s); 589 assert_sbuf_state(s, 0); 590 591 KASSERT(fmt != NULL, 592 ("%s called with a NULL format string", __func__)); 593 594 if (s->s_error != 0) 595 return (-1); 596 597 /* 598 * For the moment, there is no way to get vsnprintf(3) to hand 599 * back a character at a time, to push everything into 600 * sbuf_putc_func() as was done for the kernel. 601 * 602 * In userspace, while drains are useful, there's generally 603 * not a problem attempting to malloc(3) on out of space. So 604 * expand a userland sbuf if there is not enough room for the 605 * data produced by sbuf_[v]printf(3). 606 */ 607 608 error = 0; 609 do { 610 va_copy(ap_copy, ap); 611 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1, 612 fmt, ap_copy); 613 va_end(ap_copy); 614 615 if (SBUF_FREESPACE(s) >= len) 616 break; 617 /* Cannot print with the current available space. */ 618 if (s->s_drain_func != NULL && s->s_len > 0) 619 error = sbuf_drain(s); 620 else 621 error = sbuf_extend(s, len - SBUF_FREESPACE(s)); 622 } while (error == 0); 623 624 /* 625 * s->s_len is the length of the string, without the terminating nul. 626 * When updating s->s_len, we must subtract 1 from the length that 627 * we passed into vsnprintf() because that length includes the 628 * terminating nul. 629 * 630 * vsnprintf() returns the amount that would have been copied, 631 * given sufficient space, so don't over-increment s_len. 632 */ 633 if (SBUF_FREESPACE(s) < len) 634 len = SBUF_FREESPACE(s); 635 s->s_len += len; 636 if (SBUF_ISSECTION(s)) 637 s->s_sect_len += len; 638 if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s)) 639 s->s_error = ENOMEM; 640 641 KASSERT(s->s_len < s->s_size, 642 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size)); 643 644 if (s->s_error != 0) 645 return (-1); 646 return (0); 647 } 648 #endif /* _KERNEL */ 649 650 /* 651 * Format the given arguments and append the resulting string to an sbuf. 652 */ 653 int 654 sbuf_printf(struct sbuf *s, const char *fmt, ...) 655 { 656 va_list ap; 657 int result; 658 659 va_start(ap, fmt); 660 result = sbuf_vprintf(s, fmt, ap); 661 va_end(ap); 662 return (result); 663 } 664 665 /* 666 * Append a character to an sbuf. 667 */ 668 int 669 sbuf_putc(struct sbuf *s, int c) 670 { 671 672 sbuf_put_byte(s, c); 673 if (s->s_error != 0) 674 return (-1); 675 return (0); 676 } 677 678 /* 679 * Trim whitespace characters from end of an sbuf. 680 */ 681 int 682 sbuf_trim(struct sbuf *s) 683 { 684 685 assert_sbuf_integrity(s); 686 assert_sbuf_state(s, 0); 687 KASSERT(s->s_drain_func == NULL, 688 ("%s makes no sense on sbuf %p with drain", __func__, s)); 689 690 if (s->s_error != 0) 691 return (-1); 692 693 while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1])) { 694 --s->s_len; 695 if (SBUF_ISSECTION(s)) 696 s->s_sect_len--; 697 } 698 699 return (0); 700 } 701 702 /* 703 * Check if an sbuf has an error. 704 */ 705 int 706 sbuf_error(const struct sbuf *s) 707 { 708 709 return (s->s_error); 710 } 711 712 /* 713 * Finish off an sbuf. 714 */ 715 int 716 sbuf_finish(struct sbuf *s) 717 { 718 719 assert_sbuf_integrity(s); 720 assert_sbuf_state(s, 0); 721 722 s->s_buf[s->s_len] = '\0'; 723 if (s->s_flags & SBUF_INCLUDENUL) 724 s->s_len++; 725 if (s->s_drain_func != NULL) { 726 while (s->s_len > 0 && s->s_error == 0) 727 s->s_error = sbuf_drain(s); 728 } 729 SBUF_SETFLAG(s, SBUF_FINISHED); 730 #ifdef _KERNEL 731 return (s->s_error); 732 #else 733 if (s->s_error != 0) { 734 errno = s->s_error; 735 return (-1); 736 } 737 return (0); 738 #endif 739 } 740 741 /* 742 * Return a pointer to the sbuf data. 743 */ 744 char * 745 sbuf_data(struct sbuf *s) 746 { 747 748 assert_sbuf_integrity(s); 749 assert_sbuf_state(s, SBUF_FINISHED); 750 KASSERT(s->s_drain_func == NULL, 751 ("%s makes no sense on sbuf %p with drain", __func__, s)); 752 753 return (s->s_buf); 754 } 755 756 /* 757 * Return the length of the sbuf data. 758 */ 759 ssize_t 760 sbuf_len(struct sbuf *s) 761 { 762 763 assert_sbuf_integrity(s); 764 /* don't care if it's finished or not */ 765 KASSERT(s->s_drain_func == NULL, 766 ("%s makes no sense on sbuf %p with drain", __func__, s)); 767 768 if (s->s_error != 0) 769 return (-1); 770 771 /* If finished, nulterm is already in len, else add one. */ 772 if ((s->s_flags & (SBUF_INCLUDENUL | SBUF_FINISHED)) == SBUF_INCLUDENUL) 773 return (s->s_len + 1); 774 return (s->s_len); 775 } 776 777 /* 778 * Clear an sbuf, free its buffer if necessary. 779 */ 780 void 781 sbuf_delete(struct sbuf *s) 782 { 783 int isdyn; 784 785 assert_sbuf_integrity(s); 786 /* don't care if it's finished or not */ 787 788 if (SBUF_ISDYNAMIC(s)) 789 SBFREE(s->s_buf); 790 isdyn = SBUF_ISDYNSTRUCT(s); 791 memset(s, 0, sizeof(*s)); 792 if (isdyn) 793 SBFREE(s); 794 } 795 796 /* 797 * Check if an sbuf has been finished. 798 */ 799 int 800 sbuf_done(const struct sbuf *s) 801 { 802 803 return (SBUF_ISFINISHED(s)); 804 } 805 806 /* 807 * Start a section. 808 */ 809 void 810 sbuf_start_section(struct sbuf *s, ssize_t *old_lenp) 811 { 812 813 assert_sbuf_integrity(s); 814 assert_sbuf_state(s, 0); 815 816 if (!SBUF_ISSECTION(s)) { 817 KASSERT(s->s_sect_len == 0, 818 ("s_sect_len != 0 when starting a section")); 819 if (old_lenp != NULL) 820 *old_lenp = -1; 821 SBUF_SETFLAG(s, SBUF_INSECTION); 822 } else { 823 KASSERT(old_lenp != NULL, 824 ("s_sect_len should be saved when starting a subsection")); 825 *old_lenp = s->s_sect_len; 826 s->s_sect_len = 0; 827 } 828 } 829 830 /* 831 * End the section padding to the specified length with the specified 832 * character. 833 */ 834 ssize_t 835 sbuf_end_section(struct sbuf *s, ssize_t old_len, size_t pad, int c) 836 { 837 ssize_t len; 838 839 assert_sbuf_integrity(s); 840 assert_sbuf_state(s, 0); 841 KASSERT(SBUF_ISSECTION(s), 842 ("attempt to end a section when not in a section")); 843 844 if (pad > 1) { 845 len = roundup(s->s_sect_len, pad) - s->s_sect_len; 846 for (; s->s_error == 0 && len > 0; len--) 847 sbuf_put_byte(s, c); 848 } 849 len = s->s_sect_len; 850 if (old_len == -1) { 851 s->s_sect_len = 0; 852 SBUF_CLEARFLAG(s, SBUF_INSECTION); 853 } else { 854 s->s_sect_len += old_len; 855 } 856 if (s->s_error != 0) 857 return (-1); 858 return (len); 859 } 860