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("$FreeBSD$");
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/limits.h>
39 #include <sys/malloc.h>
40 #include <sys/systm.h>
41 #include <sys/uio.h>
42 #include <machine/stdarg.h>
43 #else /* _KERNEL */
44 #include <ctype.h>
45 #include <errno.h>
46 #include <limits.h>
47 #include <stdarg.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #endif /* _KERNEL */
52
53 #include <sys/sbuf.h>
54
55 #ifdef _KERNEL
56 static MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers");
57 #define SBMALLOC(size) malloc(size, M_SBUF, M_WAITOK|M_ZERO)
58 #define SBFREE(buf) free(buf, M_SBUF)
59 #else /* _KERNEL */
60 #define KASSERT(e, m)
61 #define SBMALLOC(size) calloc(1, size)
62 #define SBFREE(buf) free(buf)
63 #endif /* _KERNEL */
64
65 /*
66 * Predicates
67 */
68 #define SBUF_ISDYNAMIC(s) ((s)->s_flags & SBUF_DYNAMIC)
69 #define SBUF_ISDYNSTRUCT(s) ((s)->s_flags & SBUF_DYNSTRUCT)
70 #define SBUF_ISFINISHED(s) ((s)->s_flags & SBUF_FINISHED)
71 #define SBUF_HASROOM(s) ((s)->s_len < (s)->s_size - 1)
72 #define SBUF_FREESPACE(s) ((s)->s_size - ((s)->s_len + 1))
73 #define SBUF_CANEXTEND(s) ((s)->s_flags & SBUF_AUTOEXTEND)
74 #define SBUF_ISSECTION(s) ((s)->s_flags & SBUF_INSECTION)
75 #define SBUF_NULINCLUDED(s) ((s)->s_flags & SBUF_INCLUDENUL)
76
77 /*
78 * Set / clear flags
79 */
80 #define SBUF_SETFLAG(s, f) do { (s)->s_flags |= (f); } while (0)
81 #define SBUF_CLEARFLAG(s, f) do { (s)->s_flags &= ~(f); } while (0)
82
83 #define SBUF_MINSIZE 2 /* Min is 1 byte + nulterm. */
84 #define SBUF_MINEXTENDSIZE 16 /* Should be power of 2. */
85
86 #ifdef PAGE_SIZE
87 #define SBUF_MAXEXTENDSIZE PAGE_SIZE
88 #define SBUF_MAXEXTENDINCR PAGE_SIZE
89 #else
90 #define SBUF_MAXEXTENDSIZE 4096
91 #define SBUF_MAXEXTENDINCR 4096
92 #endif
93
94 /*
95 * Debugging support
96 */
97 #if defined(_KERNEL) && defined(INVARIANTS)
98
99 static void
100 _assert_sbuf_integrity(const char *fun, struct sbuf *s)
101 {
102
103 KASSERT(s != NULL,
104 ("%s called with a NULL sbuf pointer", fun));
105 KASSERT(s->s_buf != NULL,
106 ("%s called with uninitialized or corrupt sbuf", fun));
107 if (SBUF_ISFINISHED(s) && SBUF_NULINCLUDED(s)) {
108 KASSERT(s->s_len <= s->s_size,
109 ("wrote past end of sbuf (%jd >= %jd)",
110 (intmax_t)s->s_len, (intmax_t)s->s_size));
111 } else {
112 KASSERT(s->s_len < s->s_size,
113 ("wrote past end of sbuf (%jd >= %jd)",
114 (intmax_t)s->s_len, (intmax_t)s->s_size));
115 }
116 }
117
118 static void
119 _assert_sbuf_state(const char *fun, struct sbuf *s, int state)
120 {
121
122 KASSERT((s->s_flags & SBUF_FINISHED) == state,
123 ("%s called with %sfinished or corrupt sbuf", fun,
124 (state ? "un" : "")));
125 }
126
127 #define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s))
128 #define assert_sbuf_state(s, i) _assert_sbuf_state(__func__, (s), (i))
129
130 #else /* _KERNEL && INVARIANTS */
131
132 #define assert_sbuf_integrity(s) do { } while (0)
133 #define assert_sbuf_state(s, i) do { } while (0)
134
135 #endif /* _KERNEL && INVARIANTS */
136
137 #ifdef CTASSERT
138 CTASSERT(powerof2(SBUF_MAXEXTENDSIZE));
139 CTASSERT(powerof2(SBUF_MAXEXTENDINCR));
140 #endif
141
142 static int
143 sbuf_extendsize(int size)
144 {
145 int newsize;
146
147 if (size < (int)SBUF_MAXEXTENDSIZE) {
148 newsize = SBUF_MINEXTENDSIZE;
149 while (newsize < size)
150 newsize *= 2;
151 } else {
152 newsize = roundup2(size, SBUF_MAXEXTENDINCR);
153 }
154 KASSERT(newsize >= size, ("%s: %d < %d\n", __func__, newsize, size));
155 return (newsize);
156 }
157
158 /*
159 * Extend an sbuf.
160 */
161 static int
162 sbuf_extend(struct sbuf *s, int addlen)
163 {
164 char *newbuf;
165 int newsize;
166
167 if (!SBUF_CANEXTEND(s))
168 return (-1);
169 newsize = sbuf_extendsize(s->s_size + addlen);
170 newbuf = SBMALLOC(newsize);
171 if (newbuf == NULL)
172 return (-1);
173 memcpy(newbuf, s->s_buf, s->s_size);
174 if (SBUF_ISDYNAMIC(s))
175 SBFREE(s->s_buf);
176 else
177 SBUF_SETFLAG(s, SBUF_DYNAMIC);
178 s->s_buf = newbuf;
179 s->s_size = newsize;
180 return (0);
181 }
182
183 /*
184 * Initialize the internals of an sbuf.
185 * If buf is non-NULL, it points to a static or already-allocated string
186 * big enough to hold at least length characters.
187 */
188 static struct sbuf *
189 sbuf_newbuf(struct sbuf *s, char *buf, int length, int flags)
190 {
191
192 memset(s, 0, sizeof(*s));
193 s->s_flags = flags;
194 s->s_size = length;
195 s->s_buf = buf;
196
197 if ((s->s_flags & SBUF_AUTOEXTEND) == 0) {
198 KASSERT(s->s_size >= SBUF_MINSIZE,
199 ("attempt to create an sbuf smaller than %d bytes",
200 SBUF_MINSIZE));
201 }
202
203 if (s->s_buf != NULL)
204 return (s);
205
206 if ((flags & SBUF_AUTOEXTEND) != 0)
207 s->s_size = sbuf_extendsize(s->s_size);
208
209 s->s_buf = SBMALLOC(s->s_size);
210 if (s->s_buf == NULL)
211 return (NULL);
212 SBUF_SETFLAG(s, SBUF_DYNAMIC);
213 return (s);
214 }
215
216 /*
217 * Initialize an sbuf.
218 * If buf is non-NULL, it points to a static or already-allocated string
219 * big enough to hold at least length characters.
220 */
221 struct sbuf *
222 sbuf_new(struct sbuf *s, char *buf, int length, int flags)
223 {
224
225 KASSERT(length >= 0,
226 ("attempt to create an sbuf of negative length (%d)", length));
227 KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
228 ("%s called with invalid flags", __func__));
229
230 flags &= SBUF_USRFLAGMSK;
231 if (s != NULL)
232 return (sbuf_newbuf(s, buf, length, flags));
233
234 s = SBMALLOC(sizeof(*s));
235 if (s == NULL)
236 return (NULL);
237 if (sbuf_newbuf(s, buf, length, flags) == NULL) {
238 SBFREE(s);
239 return (NULL);
240 }
241 SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
242 return (s);
243 }
244
245 #ifdef _KERNEL
246 /*
247 * Create an sbuf with uio data
248 */
249 struct sbuf *
250 sbuf_uionew(struct sbuf *s, struct uio *uio, int *error)
251 {
252
253 KASSERT(uio != NULL,
254 ("%s called with NULL uio pointer", __func__));
255 KASSERT(error != NULL,
256 ("%s called with NULL error pointer", __func__));
257
258 s = sbuf_new(s, NULL, uio->uio_resid + 1, 0);
259 if (s == NULL) {
260 *error = ENOMEM;
261 return (NULL);
262 }
263 *error = uiomove(s->s_buf, uio->uio_resid, uio);
264 if (*error != 0) {
265 sbuf_delete(s);
266 return (NULL);
267 }
268 s->s_len = s->s_size - 1;
269 if (SBUF_ISSECTION(s))
270 s->s_sect_len = s->s_size - 1;
271 *error = 0;
272 return (s);
273 }
274 #endif
275
276 int
277 sbuf_get_flags(struct sbuf *s)
278 {
279
280 return (s->s_flags & SBUF_USRFLAGMSK);
281 }
282
283 void
284 sbuf_clear_flags(struct sbuf *s, int flags)
285 {
286
287 s->s_flags &= ~(flags & SBUF_USRFLAGMSK);
288 }
289
290 void
291 sbuf_set_flags(struct sbuf *s, int flags)
292 {
293
294
295 s->s_flags |= (flags & SBUF_USRFLAGMSK);
296 }
297
298 /*
299 * Clear an sbuf and reset its position.
300 */
301 void
302 sbuf_clear(struct sbuf *s)
303 {
304
305 assert_sbuf_integrity(s);
306 /* don't care if it's finished or not */
307
308 SBUF_CLEARFLAG(s, SBUF_FINISHED);
309 s->s_error = 0;
310 s->s_len = 0;
311 s->s_sect_len = 0;
312 }
313
314 /*
315 * Set the sbuf's end position to an arbitrary value.
316 * Effectively truncates the sbuf at the new position.
317 */
318 int
319 sbuf_setpos(struct sbuf *s, ssize_t pos)
320 {
321
322 assert_sbuf_integrity(s);
323 assert_sbuf_state(s, 0);
324
325 KASSERT(pos >= 0,
326 ("attempt to seek to a negative position (%jd)", (intmax_t)pos));
327 KASSERT(pos < s->s_size,
328 ("attempt to seek past end of sbuf (%jd >= %jd)",
329 (intmax_t)pos, (intmax_t)s->s_size));
330 KASSERT(!SBUF_ISSECTION(s),
331 ("attempt to seek when in a section"));
332
333 if (pos < 0 || pos > s->s_len)
334 return (-1);
335 s->s_len = pos;
336 return (0);
337 }
338
339 /*
340 * Set up a drain function and argument on an sbuf to flush data to
341 * when the sbuf buffer overflows.
342 */
343 void
344 sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx)
345 {
346
347 assert_sbuf_state(s, 0);
348 assert_sbuf_integrity(s);
349 KASSERT(func == s->s_drain_func || s->s_len == 0,
350 ("Cannot change drain to %p on non-empty sbuf %p", func, s));
351 s->s_drain_func = func;
352 s->s_drain_arg = ctx;
353 }
354
355 /*
356 * Call the drain and process the return.
357 */
358 int
359 sbuf_drain(struct sbuf *s)
360 {
361 int len;
362
363 /*
364 * Immediately return when no work to do,
365 * or an error has already been accumulated.
366 */
367 if ((s->s_len == 0) || (s->s_error != 0))
368 return(s->s_error);
369
370 len = s->s_drain_func(s->s_drain_arg, s->s_buf, s->s_len);
371 if (len < 0) {
372 s->s_error = -len;
373 return (s->s_error);
374 }
375 KASSERT(len > 0 && len <= s->s_len,
376 ("Bad drain amount %d for sbuf %p", len, s));
377 s->s_len -= len;
378 /*
379 * Fast path for the expected case where all the data was
380 * drained.
381 */
382 if (s->s_len == 0)
383 return (0);
384 /*
385 * Move the remaining characters to the beginning of the
386 * string.
387 */
388 memmove(s->s_buf, s->s_buf + len, s->s_len);
389 return (0);
390 }
391
392 /*
393 * Append bytes to an sbuf. This is the core function for appending
394 * to an sbuf and is the main place that deals with extending the
395 * buffer and marking overflow.
396 */
397 static void
398 sbuf_put_bytes(struct sbuf *s, const char *buf, size_t len)
399 {
400 size_t n;
401
402 assert_sbuf_integrity(s);
403 assert_sbuf_state(s, 0);
404
405 if (s->s_error != 0)
406 return;
407 while (len > 0) {
408 if (SBUF_FREESPACE(s) <= 0) {
409 /*
410 * If there is a drain, use it, otherwise extend the
411 * buffer.
412 */
413 if (s->s_drain_func != NULL)
414 (void)sbuf_drain(s);
415 else if (sbuf_extend(s, len > INT_MAX ? INT_MAX : len)
416 < 0)
417 s->s_error = ENOMEM;
418 if (s->s_error != 0)
419 return;
420 }
421 n = SBUF_FREESPACE(s);
422 if (len < n)
423 n = len;
424 memcpy(&s->s_buf[s->s_len], buf, n);
425 s->s_len += n;
426 if (SBUF_ISSECTION(s))
427 s->s_sect_len += n;
428 len -= n;
429 buf += n;
430 }
431 }
432
433 static void
434 sbuf_put_byte(struct sbuf *s, char c)
435 {
436
437 sbuf_put_bytes(s, &c, 1);
438 }
439
440 /*
441 * Append a byte string to an sbuf.
442 */
443 int
444 sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
445 {
446
447 sbuf_put_bytes(s, buf, len);
448 if (s->s_error != 0)
449 return (-1);
450 return (0);
451 }
452
453 #ifdef _KERNEL
454 /*
455 * Copy a byte string from userland into an sbuf.
456 */
457 int
458 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
459 {
460
461 assert_sbuf_integrity(s);
462 assert_sbuf_state(s, 0);
463 KASSERT(s->s_drain_func == NULL,
464 ("Nonsensical copyin to sbuf %p with a drain", s));
465
466 if (s->s_error != 0)
467 return (-1);
468 if (len == 0)
469 return (0);
470 if (len > SBUF_FREESPACE(s)) {
471 sbuf_extend(s, len - SBUF_FREESPACE(s));
472 if (SBUF_FREESPACE(s) < len)
473 len = SBUF_FREESPACE(s);
474 }
475 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
476 return (-1);
477 s->s_len += len;
478
479 return (0);
480 }
481 #endif
482
483 /*
484 * Copy a byte string into an sbuf.
485 */
486 int
487 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len)
488 {
489
490 assert_sbuf_integrity(s);
491 assert_sbuf_state(s, 0);
492
493 sbuf_clear(s);
494 return (sbuf_bcat(s, buf, len));
495 }
496
497 /*
498 * Append a string to an sbuf.
499 */
500 int
501 sbuf_cat(struct sbuf *s, const char *str)
502 {
503 size_t n;
504
505 n = strlen(str);
506 sbuf_put_bytes(s, str, n);
507 if (s->s_error != 0)
508 return (-1);
509 return (0);
510 }
511
512 #ifdef _KERNEL
513 /*
514 * Append a string from userland to an sbuf.
515 */
516 int
517 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
518 {
519 size_t done;
520
521 assert_sbuf_integrity(s);
522 assert_sbuf_state(s, 0);
523 KASSERT(s->s_drain_func == NULL,
524 ("Nonsensical copyin to sbuf %p with a drain", s));
525
526 if (s->s_error != 0)
527 return (-1);
528
529 if (len == 0)
530 len = SBUF_FREESPACE(s); /* XXX return 0? */
531 if (len > SBUF_FREESPACE(s)) {
532 sbuf_extend(s, len);
533 if (SBUF_FREESPACE(s) < len)
534 len = SBUF_FREESPACE(s);
535 }
536 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
537 case ENAMETOOLONG:
538 s->s_error = ENOMEM;
539 /* fall through */
540 case 0:
541 s->s_len += done - 1;
542 if (SBUF_ISSECTION(s))
543 s->s_sect_len += done - 1;
544 break;
545 default:
546 return (-1); /* XXX */
547 }
548
549 return (done);
550 }
551 #endif
552
553 /*
554 * Copy a string into an sbuf.
555 */
556 int
557 sbuf_cpy(struct sbuf *s, const char *str)
558 {
559
560 assert_sbuf_integrity(s);
561 assert_sbuf_state(s, 0);
562
563 sbuf_clear(s);
564 return (sbuf_cat(s, str));
565 }
566
567 /*
568 * Format the given argument list and append the resulting string to an sbuf.
569 */
570 #ifdef _KERNEL
571
572 /*
573 * Append a non-NUL character to an sbuf. This prototype signature is
574 * suitable for use with kvprintf(9).
575 */
576 static void
577 sbuf_putc_func(int c, void *arg)
578 {
579
580 if (c != '\0')
581 sbuf_put_byte(arg, c);
582 }
583
584 int
585 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
586 {
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 (void)kvprintf(fmt, sbuf_putc_func, s, 10, ap);
595 if (s->s_error != 0)
596 return (-1);
597 return (0);
598 }
599 #else /* !_KERNEL */
600 int
601 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
602 {
603 va_list ap_copy;
604 int error, len;
605
606 assert_sbuf_integrity(s);
607 assert_sbuf_state(s, 0);
608
609 KASSERT(fmt != NULL,
610 ("%s called with a NULL format string", __func__));
611
612 if (s->s_error != 0)
613 return (-1);
614
615 /*
616 * For the moment, there is no way to get vsnprintf(3) to hand
617 * back a character at a time, to push everything into
618 * sbuf_putc_func() as was done for the kernel.
619 *
620 * In userspace, while drains are useful, there's generally
621 * not a problem attempting to malloc(3) on out of space. So
622 * expand a userland sbuf if there is not enough room for the
623 * data produced by sbuf_[v]printf(3).
624 */
625
626 error = 0;
627 do {
628 va_copy(ap_copy, ap);
629 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
630 fmt, ap_copy);
631 if (len < 0) {
632 s->s_error = errno;
633 return (-1);
634 }
635 va_end(ap_copy);
636
637 if (SBUF_FREESPACE(s) >= len)
638 break;
639 /* Cannot print with the current available space. */
640 if (s->s_drain_func != NULL && s->s_len > 0)
641 error = sbuf_drain(s);
642 else
643 error = sbuf_extend(s, len - SBUF_FREESPACE(s));
644 } while (error == 0);
645
646 /*
647 * s->s_len is the length of the string, without the terminating nul.
648 * When updating s->s_len, we must subtract 1 from the length that
649 * we passed into vsnprintf() because that length includes the
650 * terminating nul.
651 *
652 * vsnprintf() returns the amount that would have been copied,
653 * given sufficient space, so don't over-increment s_len.
654 */
655 if (SBUF_FREESPACE(s) < len)
656 len = SBUF_FREESPACE(s);
657 s->s_len += len;
658 if (SBUF_ISSECTION(s))
659 s->s_sect_len += len;
660 if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
661 s->s_error = ENOMEM;
662
663 KASSERT(s->s_len < s->s_size,
664 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
665
666 if (s->s_error != 0)
667 return (-1);
668 return (0);
669 }
670 #endif /* _KERNEL */
671
672 /*
673 * Format the given arguments and append the resulting string to an sbuf.
674 */
675 int
676 sbuf_printf(struct sbuf *s, const char *fmt, ...)
677 {
678 va_list ap;
679 int result;
680
681 va_start(ap, fmt);
682 result = sbuf_vprintf(s, fmt, ap);
683 va_end(ap);
684 return (result);
685 }
686
687 /*
688 * Append a character to an sbuf.
689 */
690 int
691 sbuf_putc(struct sbuf *s, int c)
692 {
693
694 sbuf_put_byte(s, c);
695 if (s->s_error != 0)
696 return (-1);
697 return (0);
698 }
699
700 /*
701 * Trim whitespace characters from end of an sbuf.
702 */
703 int
704 sbuf_trim(struct sbuf *s)
705 {
706
707 assert_sbuf_integrity(s);
708 assert_sbuf_state(s, 0);
709 KASSERT(s->s_drain_func == NULL,
710 ("%s makes no sense on sbuf %p with drain", __func__, s));
711
712 if (s->s_error != 0)
713 return (-1);
714
715 while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1])) {
716 --s->s_len;
717 if (SBUF_ISSECTION(s))
718 s->s_sect_len--;
719 }
720
721 return (0);
722 }
723
724 /*
725 * Check if an sbuf has an error.
726 */
727 int
728 sbuf_error(const struct sbuf *s)
729 {
730
731 return (s->s_error);
732 }
733
734 /*
735 * Finish off an sbuf.
736 */
737 int
738 sbuf_finish(struct sbuf *s)
739 {
740
741 assert_sbuf_integrity(s);
742 assert_sbuf_state(s, 0);
743
744 s->s_buf[s->s_len] = '\0';
745 if (SBUF_NULINCLUDED(s))
746 s->s_len++;
747 if (s->s_drain_func != NULL) {
748 while (s->s_len > 0 && s->s_error == 0)
749 s->s_error = sbuf_drain(s);
750 }
751 SBUF_SETFLAG(s, SBUF_FINISHED);
752 #ifdef _KERNEL
753 return (s->s_error);
754 #else
755 if (s->s_error != 0) {
756 errno = s->s_error;
757 return (-1);
758 }
759 return (0);
760 #endif
761 }
762
763 /*
764 * Return a pointer to the sbuf data.
765 */
766 char *
767 sbuf_data(struct sbuf *s)
768 {
769
770 assert_sbuf_integrity(s);
771 assert_sbuf_state(s, SBUF_FINISHED);
772 KASSERT(s->s_drain_func == NULL,
773 ("%s makes no sense on sbuf %p with drain", __func__, s));
774
775 return (s->s_buf);
776 }
777
778 /*
779 * Return the length of the sbuf data.
780 */
781 ssize_t
782 sbuf_len(struct sbuf *s)
783 {
784
785 assert_sbuf_integrity(s);
786 /* don't care if it's finished or not */
787 KASSERT(s->s_drain_func == NULL,
788 ("%s makes no sense on sbuf %p with drain", __func__, s));
789
790 if (s->s_error != 0)
791 return (-1);
792
793 /* If finished, nulterm is already in len, else add one. */
794 if (SBUF_NULINCLUDED(s) && !SBUF_ISFINISHED(s))
795 return (s->s_len + 1);
796 return (s->s_len);
797 }
798
799 /*
800 * Clear an sbuf, free its buffer if necessary.
801 */
802 void
803 sbuf_delete(struct sbuf *s)
804 {
805 int isdyn;
806
807 assert_sbuf_integrity(s);
808 /* don't care if it's finished or not */
809
810 if (SBUF_ISDYNAMIC(s))
811 SBFREE(s->s_buf);
812 isdyn = SBUF_ISDYNSTRUCT(s);
813 memset(s, 0, sizeof(*s));
814 if (isdyn)
815 SBFREE(s);
816 }
817
818 /*
819 * Check if an sbuf has been finished.
820 */
821 int
822 sbuf_done(const struct sbuf *s)
823 {
824
825 return (SBUF_ISFINISHED(s));
826 }
827
828 /*
829 * Start a section.
830 */
831 void
832 sbuf_start_section(struct sbuf *s, ssize_t *old_lenp)
833 {
834
835 assert_sbuf_integrity(s);
836 assert_sbuf_state(s, 0);
837
838 if (!SBUF_ISSECTION(s)) {
839 KASSERT(s->s_sect_len == 0,
840 ("s_sect_len != 0 when starting a section"));
841 if (old_lenp != NULL)
842 *old_lenp = -1;
843 SBUF_SETFLAG(s, SBUF_INSECTION);
844 } else {
845 KASSERT(old_lenp != NULL,
846 ("s_sect_len should be saved when starting a subsection"));
847 *old_lenp = s->s_sect_len;
848 s->s_sect_len = 0;
849 }
850 }
851
852 /*
853 * End the section padding to the specified length with the specified
854 * character.
855 */
856 ssize_t
857 sbuf_end_section(struct sbuf *s, ssize_t old_len, size_t pad, int c)
858 {
859 ssize_t len;
860
861 assert_sbuf_integrity(s);
862 assert_sbuf_state(s, 0);
863 KASSERT(SBUF_ISSECTION(s),
864 ("attempt to end a section when not in a section"));
865
866 if (pad > 1) {
867 len = roundup(s->s_sect_len, pad) - s->s_sect_len;
868 for (; s->s_error == 0 && len > 0; len--)
869 sbuf_put_byte(s, c);
870 }
871 len = s->s_sect_len;
872 if (old_len == -1) {
873 s->s_sect_len = 0;
874 SBUF_CLEARFLAG(s, SBUF_INSECTION);
875 } else {
876 s->s_sect_len += old_len;
877 }
878 if (s->s_error != 0)
879 return (-1);
880 return (len);
881 }
Cache object: 6eeca20fe07d7489501d66a1166b4047
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