FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_sbuf.c
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: releng/9.2/sys/kern/subr_sbuf.c 250308 2013-05-06 20:32:14Z trociny $");
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)
56 #define SBFREE(buf) free(buf, M_SBUF)
57 #else /* _KERNEL */
58 #define KASSERT(e, m)
59 #define SBMALLOC(size) malloc(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 /*
266 * Clear an sbuf and reset its position.
267 */
268 void
269 sbuf_clear(struct sbuf *s)
270 {
271
272 assert_sbuf_integrity(s);
273 /* don't care if it's finished or not */
274
275 SBUF_CLEARFLAG(s, SBUF_FINISHED);
276 s->s_error = 0;
277 s->s_len = 0;
278 s->s_sect_len = 0;
279 }
280
281 /*
282 * Set the sbuf's end position to an arbitrary value.
283 * Effectively truncates the sbuf at the new position.
284 */
285 int
286 sbuf_setpos(struct sbuf *s, ssize_t pos)
287 {
288
289 assert_sbuf_integrity(s);
290 assert_sbuf_state(s, 0);
291
292 KASSERT(pos >= 0,
293 ("attempt to seek to a negative position (%jd)", (intmax_t)pos));
294 KASSERT(pos < s->s_size,
295 ("attempt to seek past end of sbuf (%jd >= %jd)",
296 (intmax_t)pos, (intmax_t)s->s_size));
297 KASSERT(!SBUF_ISSECTION(s),
298 ("attempt to seek when in a section"));
299
300 if (pos < 0 || pos > s->s_len)
301 return (-1);
302 s->s_len = pos;
303 return (0);
304 }
305
306 /*
307 * Set up a drain function and argument on an sbuf to flush data to
308 * when the sbuf buffer overflows.
309 */
310 void
311 sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx)
312 {
313
314 assert_sbuf_state(s, 0);
315 assert_sbuf_integrity(s);
316 KASSERT(func == s->s_drain_func || s->s_len == 0,
317 ("Cannot change drain to %p on non-empty sbuf %p", func, s));
318 s->s_drain_func = func;
319 s->s_drain_arg = ctx;
320 }
321
322 /*
323 * Call the drain and process the return.
324 */
325 static int
326 sbuf_drain(struct sbuf *s)
327 {
328 int len;
329
330 KASSERT(s->s_len > 0, ("Shouldn't drain empty sbuf %p", s));
331 KASSERT(s->s_error == 0, ("Called %s with error on %p", __func__, s));
332 len = s->s_drain_func(s->s_drain_arg, s->s_buf, s->s_len);
333 if (len < 0) {
334 s->s_error = -len;
335 return (s->s_error);
336 }
337 KASSERT(len > 0 && len <= s->s_len,
338 ("Bad drain amount %d for sbuf %p", len, s));
339 s->s_len -= len;
340 /*
341 * Fast path for the expected case where all the data was
342 * drained.
343 */
344 if (s->s_len == 0)
345 return (0);
346 /*
347 * Move the remaining characters to the beginning of the
348 * string.
349 */
350 memmove(s->s_buf, s->s_buf + len, s->s_len);
351 return (0);
352 }
353
354 /*
355 * Append a byte to an sbuf. This is the core function for appending
356 * to an sbuf and is the main place that deals with extending the
357 * buffer and marking overflow.
358 */
359 static void
360 sbuf_put_byte(struct sbuf *s, int c)
361 {
362
363 assert_sbuf_integrity(s);
364 assert_sbuf_state(s, 0);
365
366 if (s->s_error != 0)
367 return;
368 if (SBUF_FREESPACE(s) <= 0) {
369 /*
370 * If there is a drain, use it, otherwise extend the
371 * buffer.
372 */
373 if (s->s_drain_func != NULL)
374 (void)sbuf_drain(s);
375 else if (sbuf_extend(s, 1) < 0)
376 s->s_error = ENOMEM;
377 if (s->s_error != 0)
378 return;
379 }
380 s->s_buf[s->s_len++] = c;
381 if (SBUF_ISSECTION(s))
382 s->s_sect_len++;
383 }
384
385 /*
386 * Append a byte string to an sbuf.
387 */
388 int
389 sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
390 {
391 const char *str = buf;
392 const char *end = str + len;
393
394 assert_sbuf_integrity(s);
395 assert_sbuf_state(s, 0);
396
397 if (s->s_error != 0)
398 return (-1);
399 for (; str < end; str++) {
400 sbuf_put_byte(s, *str);
401 if (s->s_error != 0)
402 return (-1);
403 }
404 return (0);
405 }
406
407 #ifdef _KERNEL
408 /*
409 * Copy a byte string from userland into an sbuf.
410 */
411 int
412 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
413 {
414
415 assert_sbuf_integrity(s);
416 assert_sbuf_state(s, 0);
417 KASSERT(s->s_drain_func == NULL,
418 ("Nonsensical copyin to sbuf %p with a drain", s));
419
420 if (s->s_error != 0)
421 return (-1);
422 if (len == 0)
423 return (0);
424 if (len > SBUF_FREESPACE(s)) {
425 sbuf_extend(s, len - SBUF_FREESPACE(s));
426 if (SBUF_FREESPACE(s) < len)
427 len = SBUF_FREESPACE(s);
428 }
429 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
430 return (-1);
431 s->s_len += len;
432
433 return (0);
434 }
435 #endif
436
437 /*
438 * Copy a byte string into an sbuf.
439 */
440 int
441 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len)
442 {
443
444 assert_sbuf_integrity(s);
445 assert_sbuf_state(s, 0);
446
447 sbuf_clear(s);
448 return (sbuf_bcat(s, buf, len));
449 }
450
451 /*
452 * Append a string to an sbuf.
453 */
454 int
455 sbuf_cat(struct sbuf *s, const char *str)
456 {
457
458 assert_sbuf_integrity(s);
459 assert_sbuf_state(s, 0);
460
461 if (s->s_error != 0)
462 return (-1);
463
464 while (*str != '\0') {
465 sbuf_put_byte(s, *str++);
466 if (s->s_error != 0)
467 return (-1);
468 }
469 return (0);
470 }
471
472 #ifdef _KERNEL
473 /*
474 * Append a string from userland to an sbuf.
475 */
476 int
477 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
478 {
479 size_t done;
480
481 assert_sbuf_integrity(s);
482 assert_sbuf_state(s, 0);
483 KASSERT(s->s_drain_func == NULL,
484 ("Nonsensical copyin to sbuf %p with a drain", s));
485
486 if (s->s_error != 0)
487 return (-1);
488
489 if (len == 0)
490 len = SBUF_FREESPACE(s); /* XXX return 0? */
491 if (len > SBUF_FREESPACE(s)) {
492 sbuf_extend(s, len);
493 if (SBUF_FREESPACE(s) < len)
494 len = SBUF_FREESPACE(s);
495 }
496 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
497 case ENAMETOOLONG:
498 s->s_error = ENOMEM;
499 /* fall through */
500 case 0:
501 s->s_len += done - 1;
502 if (SBUF_ISSECTION(s))
503 s->s_sect_len += done - 1;
504 break;
505 default:
506 return (-1); /* XXX */
507 }
508
509 return (done);
510 }
511 #endif
512
513 /*
514 * Copy a string into an sbuf.
515 */
516 int
517 sbuf_cpy(struct sbuf *s, const char *str)
518 {
519
520 assert_sbuf_integrity(s);
521 assert_sbuf_state(s, 0);
522
523 sbuf_clear(s);
524 return (sbuf_cat(s, str));
525 }
526
527 /*
528 * Format the given argument list and append the resulting string to an sbuf.
529 */
530 #ifdef _KERNEL
531
532 /*
533 * Append a non-NUL character to an sbuf. This prototype signature is
534 * suitable for use with kvprintf(9).
535 */
536 static void
537 sbuf_putc_func(int c, void *arg)
538 {
539
540 if (c != '\0')
541 sbuf_put_byte(arg, c);
542 }
543
544 int
545 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
546 {
547
548 assert_sbuf_integrity(s);
549 assert_sbuf_state(s, 0);
550
551 KASSERT(fmt != NULL,
552 ("%s called with a NULL format string", __func__));
553
554 (void)kvprintf(fmt, sbuf_putc_func, s, 10, ap);
555 if (s->s_error != 0)
556 return (-1);
557 return (0);
558 }
559 #else /* !_KERNEL */
560 int
561 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
562 {
563 va_list ap_copy;
564 int error, len;
565
566 assert_sbuf_integrity(s);
567 assert_sbuf_state(s, 0);
568
569 KASSERT(fmt != NULL,
570 ("%s called with a NULL format string", __func__));
571
572 if (s->s_error != 0)
573 return (-1);
574
575 /*
576 * For the moment, there is no way to get vsnprintf(3) to hand
577 * back a character at a time, to push everything into
578 * sbuf_putc_func() as was done for the kernel.
579 *
580 * In userspace, while drains are useful, there's generally
581 * not a problem attempting to malloc(3) on out of space. So
582 * expand a userland sbuf if there is not enough room for the
583 * data produced by sbuf_[v]printf(3).
584 */
585
586 error = 0;
587 do {
588 va_copy(ap_copy, ap);
589 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
590 fmt, ap_copy);
591 va_end(ap_copy);
592
593 if (SBUF_FREESPACE(s) >= len)
594 break;
595 /* Cannot print with the current available space. */
596 if (s->s_drain_func != NULL && s->s_len > 0)
597 error = sbuf_drain(s);
598 else
599 error = sbuf_extend(s, len - SBUF_FREESPACE(s));
600 } while (error == 0);
601
602 /*
603 * s->s_len is the length of the string, without the terminating nul.
604 * When updating s->s_len, we must subtract 1 from the length that
605 * we passed into vsnprintf() because that length includes the
606 * terminating nul.
607 *
608 * vsnprintf() returns the amount that would have been copied,
609 * given sufficient space, so don't over-increment s_len.
610 */
611 if (SBUF_FREESPACE(s) < len)
612 len = SBUF_FREESPACE(s);
613 s->s_len += len;
614 if (SBUF_ISSECTION(s))
615 s->s_sect_len += len;
616 if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
617 s->s_error = ENOMEM;
618
619 KASSERT(s->s_len < s->s_size,
620 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
621
622 if (s->s_error != 0)
623 return (-1);
624 return (0);
625 }
626 #endif /* _KERNEL */
627
628 /*
629 * Format the given arguments and append the resulting string to an sbuf.
630 */
631 int
632 sbuf_printf(struct sbuf *s, const char *fmt, ...)
633 {
634 va_list ap;
635 int result;
636
637 va_start(ap, fmt);
638 result = sbuf_vprintf(s, fmt, ap);
639 va_end(ap);
640 return (result);
641 }
642
643 /*
644 * Append a character to an sbuf.
645 */
646 int
647 sbuf_putc(struct sbuf *s, int c)
648 {
649
650 sbuf_put_byte(s, c);
651 if (s->s_error != 0)
652 return (-1);
653 return (0);
654 }
655
656 /*
657 * Trim whitespace characters from end of an sbuf.
658 */
659 int
660 sbuf_trim(struct sbuf *s)
661 {
662
663 assert_sbuf_integrity(s);
664 assert_sbuf_state(s, 0);
665 KASSERT(s->s_drain_func == NULL,
666 ("%s makes no sense on sbuf %p with drain", __func__, s));
667
668 if (s->s_error != 0)
669 return (-1);
670
671 while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1])) {
672 --s->s_len;
673 if (SBUF_ISSECTION(s))
674 s->s_sect_len--;
675 }
676
677 return (0);
678 }
679
680 /*
681 * Check if an sbuf has an error.
682 */
683 int
684 sbuf_error(const struct sbuf *s)
685 {
686
687 return (s->s_error);
688 }
689
690 /*
691 * Finish off an sbuf.
692 */
693 int
694 sbuf_finish(struct sbuf *s)
695 {
696
697 assert_sbuf_integrity(s);
698 assert_sbuf_state(s, 0);
699
700 if (s->s_drain_func != NULL) {
701 while (s->s_len > 0 && s->s_error == 0)
702 s->s_error = sbuf_drain(s);
703 }
704 s->s_buf[s->s_len] = '\0';
705 SBUF_SETFLAG(s, SBUF_FINISHED);
706 #ifdef _KERNEL
707 return (s->s_error);
708 #else
709 errno = s->s_error;
710 if (s->s_error)
711 return (-1);
712 return (0);
713 #endif
714 }
715
716 /*
717 * Return a pointer to the sbuf data.
718 */
719 char *
720 sbuf_data(struct sbuf *s)
721 {
722
723 assert_sbuf_integrity(s);
724 assert_sbuf_state(s, SBUF_FINISHED);
725 KASSERT(s->s_drain_func == NULL,
726 ("%s makes no sense on sbuf %p with drain", __func__, s));
727
728 return (s->s_buf);
729 }
730
731 /*
732 * Return the length of the sbuf data.
733 */
734 ssize_t
735 sbuf_len(struct sbuf *s)
736 {
737
738 assert_sbuf_integrity(s);
739 /* don't care if it's finished or not */
740 KASSERT(s->s_drain_func == NULL,
741 ("%s makes no sense on sbuf %p with drain", __func__, s));
742
743 if (s->s_error != 0)
744 return (-1);
745 return (s->s_len);
746 }
747
748 /*
749 * Clear an sbuf, free its buffer if necessary.
750 */
751 void
752 sbuf_delete(struct sbuf *s)
753 {
754 int isdyn;
755
756 assert_sbuf_integrity(s);
757 /* don't care if it's finished or not */
758
759 if (SBUF_ISDYNAMIC(s))
760 SBFREE(s->s_buf);
761 isdyn = SBUF_ISDYNSTRUCT(s);
762 memset(s, 0, sizeof(*s));
763 if (isdyn)
764 SBFREE(s);
765 }
766
767 /*
768 * Check if an sbuf has been finished.
769 */
770 int
771 sbuf_done(const struct sbuf *s)
772 {
773
774 return (SBUF_ISFINISHED(s));
775 }
776
777 /*
778 * Start a section.
779 */
780 void
781 sbuf_start_section(struct sbuf *s, ssize_t *old_lenp)
782 {
783
784 assert_sbuf_integrity(s);
785 assert_sbuf_state(s, 0);
786
787 if (!SBUF_ISSECTION(s)) {
788 KASSERT(s->s_sect_len == 0,
789 ("s_sect_len != 0 when starting a section"));
790 if (old_lenp != NULL)
791 *old_lenp = -1;
792 SBUF_SETFLAG(s, SBUF_INSECTION);
793 } else {
794 KASSERT(old_lenp != NULL,
795 ("s_sect_len should be saved when starting a subsection"));
796 *old_lenp = s->s_sect_len;
797 s->s_sect_len = 0;
798 }
799 }
800
801 /*
802 * End the section padding to the specified length with the specified
803 * character.
804 */
805 ssize_t
806 sbuf_end_section(struct sbuf *s, ssize_t old_len, size_t pad, int c)
807 {
808 ssize_t len;
809
810 assert_sbuf_integrity(s);
811 assert_sbuf_state(s, 0);
812 KASSERT(SBUF_ISSECTION(s),
813 ("attempt to end a section when not in a section"));
814
815 if (pad > 1) {
816 len = roundup(s->s_sect_len, pad) - s->s_sect_len;
817 for (; s->s_error == 0 && len > 0; len--)
818 sbuf_put_byte(s, c);
819 }
820 len = s->s_sect_len;
821 if (old_len == -1) {
822 s->s_sect_len = 0;
823 SBUF_CLEARFLAG(s, SBUF_INSECTION);
824 } else {
825 s->s_sect_len += old_len;
826 }
827 if (s->s_error != 0)
828 return (-1);
829 return (len);
830 }
Cache object: 5e1ab96356c2dc95fcf459573382dddd
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