2 * Copyright (c) 2000-2008 Poul-Henning Kamp
3 * Copyright (c) 2000-2008 Dag-Erling Coïdan Smørgrav
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
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
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
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>
41 #include <machine/stdarg.h>
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)
59 #define SBMALLOC(size) calloc(1, size)
60 #define SBFREE(buf) free(buf)
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)
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)
80 #define SBUF_MINEXTENDSIZE 16 /* Should be power of 2. */
83 #define SBUF_MAXEXTENDSIZE PAGE_SIZE
84 #define SBUF_MAXEXTENDINCR PAGE_SIZE
86 #define SBUF_MAXEXTENDSIZE 4096
87 #define SBUF_MAXEXTENDINCR 4096
93 #if defined(_KERNEL) && defined(INVARIANTS)
96 _assert_sbuf_integrity(const char *fun, struct sbuf *s)
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));
109 _assert_sbuf_state(const char *fun, struct sbuf *s, int state)
112 KASSERT((s->s_flags & SBUF_FINISHED) == state,
113 ("%s called with %sfinished or corrupt sbuf", fun,
114 (state ? "un" : "")));
117 #define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s))
118 #define assert_sbuf_state(s, i) _assert_sbuf_state(__func__, (s), (i))
120 #else /* _KERNEL && INVARIANTS */
122 #define assert_sbuf_integrity(s) do { } while (0)
123 #define assert_sbuf_state(s, i) do { } while (0)
125 #endif /* _KERNEL && INVARIANTS */
128 CTASSERT(powerof2(SBUF_MAXEXTENDSIZE));
129 CTASSERT(powerof2(SBUF_MAXEXTENDINCR));
133 sbuf_extendsize(int size)
137 if (size < (int)SBUF_MAXEXTENDSIZE) {
138 newsize = SBUF_MINEXTENDSIZE;
139 while (newsize < size)
142 newsize = roundup2(size, SBUF_MAXEXTENDINCR);
144 KASSERT(newsize >= size, ("%s: %d < %d\n", __func__, newsize, size));
152 sbuf_extend(struct sbuf *s, int addlen)
157 if (!SBUF_CANEXTEND(s))
159 newsize = sbuf_extendsize(s->s_size + addlen);
160 newbuf = SBMALLOC(newsize);
163 memcpy(newbuf, s->s_buf, s->s_size);
164 if (SBUF_ISDYNAMIC(s))
167 SBUF_SETFLAG(s, SBUF_DYNAMIC);
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.
179 sbuf_newbuf(struct sbuf *s, char *buf, int length, int flags)
182 memset(s, 0, sizeof(*s));
187 if ((s->s_flags & SBUF_AUTOEXTEND) == 0) {
188 KASSERT(s->s_size >= 0,
189 ("attempt to create a too small sbuf"));
192 if (s->s_buf != NULL)
195 if ((flags & SBUF_AUTOEXTEND) != 0)
196 s->s_size = sbuf_extendsize(s->s_size);
198 s->s_buf = SBMALLOC(s->s_size);
199 if (s->s_buf == NULL)
201 SBUF_SETFLAG(s, SBUF_DYNAMIC);
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.
211 sbuf_new(struct sbuf *s, char *buf, int length, int flags)
215 ("attempt to create an sbuf of negative length (%d)", length));
216 KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
217 ("%s called with invalid flags", __func__));
219 flags &= SBUF_USRFLAGMSK;
221 return (sbuf_newbuf(s, buf, length, flags));
223 s = SBMALLOC(sizeof(*s));
226 if (sbuf_newbuf(s, buf, length, flags) == NULL) {
230 SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
236 * Create an sbuf with uio data
239 sbuf_uionew(struct sbuf *s, struct uio *uio, int *error)
243 ("%s called with NULL uio pointer", __func__));
244 KASSERT(error != NULL,
245 ("%s called with NULL error pointer", __func__));
247 s = sbuf_new(s, NULL, uio->uio_resid + 1, 0);
252 *error = uiomove(s->s_buf, uio->uio_resid, uio);
257 s->s_len = s->s_size - 1;
258 if (SBUF_ISSECTION(s))
259 s->s_sect_len = s->s_size - 1;
266 sbuf_get_flags(struct sbuf *s)
269 return (s->s_flags & SBUF_USRFLAGMSK);
273 sbuf_clear_flags(struct sbuf *s, int flags)
276 s->s_flags &= ~(flags & SBUF_USRFLAGMSK);
280 sbuf_set_flags(struct sbuf *s, int flags)
284 s->s_flags |= (flags & SBUF_USRFLAGMSK);
288 * Clear an sbuf and reset its position.
291 sbuf_clear(struct sbuf *s)
294 assert_sbuf_integrity(s);
295 /* don't care if it's finished or not */
297 SBUF_CLEARFLAG(s, SBUF_FINISHED);
304 * Set the sbuf's end position to an arbitrary value.
305 * Effectively truncates the sbuf at the new position.
308 sbuf_setpos(struct sbuf *s, ssize_t pos)
311 assert_sbuf_integrity(s);
312 assert_sbuf_state(s, 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"));
322 if (pos < 0 || pos > s->s_len)
329 * Set up a drain function and argument on an sbuf to flush data to
330 * when the sbuf buffer overflows.
333 sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx)
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;
345 * Call the drain and process the return.
348 sbuf_drain(struct sbuf *s)
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);
359 KASSERT(len > 0 && len <= s->s_len,
360 ("Bad drain amount %d for sbuf %p", len, s));
363 * Fast path for the expected case where all the data was
369 * Move the remaining characters to the beginning of the
372 memmove(s->s_buf, s->s_buf + len, s->s_len);
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.
382 sbuf_put_byte(struct sbuf *s, int c)
385 assert_sbuf_integrity(s);
386 assert_sbuf_state(s, 0);
390 if (SBUF_FREESPACE(s) <= 0) {
392 * If there is a drain, use it, otherwise extend the
395 if (s->s_drain_func != NULL)
397 else if (sbuf_extend(s, 1) < 0)
402 s->s_buf[s->s_len++] = c;
403 if (SBUF_ISSECTION(s))
408 * Append a byte string to an sbuf.
411 sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
413 const char *str = buf;
414 const char *end = str + len;
416 assert_sbuf_integrity(s);
417 assert_sbuf_state(s, 0);
421 for (; str < end; str++) {
422 sbuf_put_byte(s, *str);
431 * Copy a byte string from userland into an sbuf.
434 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
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));
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);
451 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
460 * Copy a byte string into an sbuf.
463 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len)
466 assert_sbuf_integrity(s);
467 assert_sbuf_state(s, 0);
470 return (sbuf_bcat(s, buf, len));
474 * Append a string to an sbuf.
477 sbuf_cat(struct sbuf *s, const char *str)
480 assert_sbuf_integrity(s);
481 assert_sbuf_state(s, 0);
486 while (*str != '\0') {
487 sbuf_put_byte(s, *str++);
496 * Append a string from userland to an sbuf.
499 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
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));
512 len = SBUF_FREESPACE(s); /* XXX return 0? */
513 if (len > SBUF_FREESPACE(s)) {
515 if (SBUF_FREESPACE(s) < len)
516 len = SBUF_FREESPACE(s);
518 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
523 s->s_len += done - 1;
524 if (SBUF_ISSECTION(s))
525 s->s_sect_len += done - 1;
528 return (-1); /* XXX */
536 * Copy a string into an sbuf.
539 sbuf_cpy(struct sbuf *s, const char *str)
542 assert_sbuf_integrity(s);
543 assert_sbuf_state(s, 0);
546 return (sbuf_cat(s, str));
550 * Format the given argument list and append the resulting string to an sbuf.
555 * Append a non-NUL character to an sbuf. This prototype signature is
556 * suitable for use with kvprintf(9).
559 sbuf_putc_func(int c, void *arg)
563 sbuf_put_byte(arg, c);
567 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
570 assert_sbuf_integrity(s);
571 assert_sbuf_state(s, 0);
574 ("%s called with a NULL format string", __func__));
576 (void)kvprintf(fmt, sbuf_putc_func, s, 10, ap);
583 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
588 assert_sbuf_integrity(s);
589 assert_sbuf_state(s, 0);
592 ("%s called with a NULL format string", __func__));
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.
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).
610 va_copy(ap_copy, ap);
611 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
615 if (SBUF_FREESPACE(s) >= len)
617 /* Cannot print with the current available space. */
618 if (s->s_drain_func != NULL && s->s_len > 0)
619 error = sbuf_drain(s);
621 error = sbuf_extend(s, len - SBUF_FREESPACE(s));
622 } while (error == 0);
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
630 * vsnprintf() returns the amount that would have been copied,
631 * given sufficient space, so don't over-increment s_len.
633 if (SBUF_FREESPACE(s) < len)
634 len = SBUF_FREESPACE(s);
636 if (SBUF_ISSECTION(s))
637 s->s_sect_len += len;
638 if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
641 KASSERT(s->s_len < s->s_size,
642 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
651 * Format the given arguments and append the resulting string to an sbuf.
654 sbuf_printf(struct sbuf *s, const char *fmt, ...)
660 result = sbuf_vprintf(s, fmt, ap);
666 * Append a character to an sbuf.
669 sbuf_putc(struct sbuf *s, int c)
679 * Trim whitespace characters from end of an sbuf.
682 sbuf_trim(struct sbuf *s)
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));
693 while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1])) {
695 if (SBUF_ISSECTION(s))
703 * Check if an sbuf has an error.
706 sbuf_error(const struct sbuf *s)
713 * Finish off an sbuf.
716 sbuf_finish(struct sbuf *s)
719 assert_sbuf_integrity(s);
720 assert_sbuf_state(s, 0);
722 s->s_buf[s->s_len] = '\0';
723 if (s->s_flags & SBUF_INCLUDENUL)
725 if (s->s_drain_func != NULL) {
726 while (s->s_len > 0 && s->s_error == 0)
727 s->s_error = sbuf_drain(s);
729 SBUF_SETFLAG(s, SBUF_FINISHED);
733 if (s->s_error != 0) {
742 * Return a pointer to the sbuf data.
745 sbuf_data(struct sbuf *s)
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));
757 * Return the length of the sbuf data.
760 sbuf_len(struct sbuf *s)
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));
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);
778 * Clear an sbuf, free its buffer if necessary.
781 sbuf_delete(struct sbuf *s)
785 assert_sbuf_integrity(s);
786 /* don't care if it's finished or not */
788 if (SBUF_ISDYNAMIC(s))
790 isdyn = SBUF_ISDYNSTRUCT(s);
791 memset(s, 0, sizeof(*s));
797 * Check if an sbuf has been finished.
800 sbuf_done(const struct sbuf *s)
803 return (SBUF_ISFINISHED(s));
810 sbuf_start_section(struct sbuf *s, ssize_t *old_lenp)
813 assert_sbuf_integrity(s);
814 assert_sbuf_state(s, 0);
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)
821 SBUF_SETFLAG(s, SBUF_INSECTION);
823 KASSERT(old_lenp != NULL,
824 ("s_sect_len should be saved when starting a subsection"));
825 *old_lenp = s->s_sect_len;
831 * End the section padding to the specified length with the specified
835 sbuf_end_section(struct sbuf *s, ssize_t old_len, size_t pad, int c)
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"));
845 len = roundup(s->s_sect_len, pad) - s->s_sect_len;
846 for (; s->s_error == 0 && len > 0; len--)
852 SBUF_CLEARFLAG(s, SBUF_INSECTION);
854 s->s_sect_len += old_len;