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/limits.h>
39 #include <sys/malloc.h>
40 #include <sys/systm.h>
42 #include <machine/stdarg.h>
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)
61 #define SBMALLOC(size) calloc(1, size)
62 #define SBFREE(buf) free(buf)
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 #define SBUF_ISDRAINTOEOR(s) ((s)->s_flags & SBUF_DRAINTOEOR)
77 #define SBUF_DODRAINTOEOR(s) (SBUF_ISSECTION(s) && SBUF_ISDRAINTOEOR(s))
82 #define SBUF_SETFLAG(s, f) do { (s)->s_flags |= (f); } while (0)
83 #define SBUF_CLEARFLAG(s, f) do { (s)->s_flags &= ~(f); } while (0)
85 #define SBUF_MINSIZE 2 /* Min is 1 byte + nulterm. */
86 #define SBUF_MINEXTENDSIZE 16 /* Should be power of 2. */
89 #define SBUF_MAXEXTENDSIZE PAGE_SIZE
90 #define SBUF_MAXEXTENDINCR PAGE_SIZE
92 #define SBUF_MAXEXTENDSIZE 4096
93 #define SBUF_MAXEXTENDINCR 4096
99 #if defined(_KERNEL) && defined(INVARIANTS)
102 _assert_sbuf_integrity(const char *fun, struct sbuf *s)
106 ("%s called with a NULL sbuf pointer", fun));
107 KASSERT(s->s_buf != NULL,
108 ("%s called with uninitialized or corrupt sbuf", fun));
109 if (SBUF_ISFINISHED(s) && SBUF_NULINCLUDED(s)) {
110 KASSERT(s->s_len <= s->s_size,
111 ("wrote past end of sbuf (%jd >= %jd)",
112 (intmax_t)s->s_len, (intmax_t)s->s_size));
114 KASSERT(s->s_len < s->s_size,
115 ("wrote past end of sbuf (%jd >= %jd)",
116 (intmax_t)s->s_len, (intmax_t)s->s_size));
121 _assert_sbuf_state(const char *fun, struct sbuf *s, int state)
124 KASSERT((s->s_flags & SBUF_FINISHED) == state,
125 ("%s called with %sfinished or corrupt sbuf", fun,
126 (state ? "un" : "")));
129 #define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s))
130 #define assert_sbuf_state(s, i) _assert_sbuf_state(__func__, (s), (i))
132 #else /* _KERNEL && INVARIANTS */
134 #define assert_sbuf_integrity(s) do { } while (0)
135 #define assert_sbuf_state(s, i) do { } while (0)
137 #endif /* _KERNEL && INVARIANTS */
140 CTASSERT(powerof2(SBUF_MAXEXTENDSIZE));
141 CTASSERT(powerof2(SBUF_MAXEXTENDINCR));
145 sbuf_extendsize(int size)
149 if (size < (int)SBUF_MAXEXTENDSIZE) {
150 newsize = SBUF_MINEXTENDSIZE;
151 while (newsize < size)
154 newsize = roundup2(size, SBUF_MAXEXTENDINCR);
156 KASSERT(newsize >= size, ("%s: %d < %d\n", __func__, newsize, size));
164 sbuf_extend(struct sbuf *s, int addlen)
169 if (!SBUF_CANEXTEND(s))
171 newsize = sbuf_extendsize(s->s_size + addlen);
172 newbuf = SBMALLOC(newsize);
175 memcpy(newbuf, s->s_buf, s->s_size);
176 if (SBUF_ISDYNAMIC(s))
179 SBUF_SETFLAG(s, SBUF_DYNAMIC);
186 * Initialize the internals of an sbuf.
187 * If buf is non-NULL, it points to a static or already-allocated string
188 * big enough to hold at least length characters.
191 sbuf_newbuf(struct sbuf *s, char *buf, int length, int flags)
194 memset(s, 0, sizeof(*s));
199 if ((s->s_flags & SBUF_AUTOEXTEND) == 0) {
200 KASSERT(s->s_size >= SBUF_MINSIZE,
201 ("attempt to create an sbuf smaller than %d bytes",
205 if (s->s_buf != NULL)
208 if ((flags & SBUF_AUTOEXTEND) != 0)
209 s->s_size = sbuf_extendsize(s->s_size);
211 s->s_buf = SBMALLOC(s->s_size);
212 if (s->s_buf == NULL)
214 SBUF_SETFLAG(s, SBUF_DYNAMIC);
219 * Initialize an sbuf.
220 * If buf is non-NULL, it points to a static or already-allocated string
221 * big enough to hold at least length characters.
224 sbuf_new(struct sbuf *s, char *buf, int length, int flags)
228 ("attempt to create an sbuf of negative length (%d)", length));
229 KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
230 ("%s called with invalid flags", __func__));
232 flags &= SBUF_USRFLAGMSK;
234 return (sbuf_newbuf(s, buf, length, flags));
236 s = SBMALLOC(sizeof(*s));
239 if (sbuf_newbuf(s, buf, length, flags) == NULL) {
243 SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
249 * Create an sbuf with uio data
252 sbuf_uionew(struct sbuf *s, struct uio *uio, int *error)
256 ("%s called with NULL uio pointer", __func__));
257 KASSERT(error != NULL,
258 ("%s called with NULL error pointer", __func__));
260 s = sbuf_new(s, NULL, uio->uio_resid + 1, 0);
265 *error = uiomove(s->s_buf, uio->uio_resid, uio);
270 s->s_len = s->s_size - 1;
271 if (SBUF_ISSECTION(s))
272 s->s_sect_len = s->s_size - 1;
279 sbuf_get_flags(struct sbuf *s)
282 return (s->s_flags & SBUF_USRFLAGMSK);
286 sbuf_clear_flags(struct sbuf *s, int flags)
289 s->s_flags &= ~(flags & SBUF_USRFLAGMSK);
293 sbuf_set_flags(struct sbuf *s, int flags)
297 s->s_flags |= (flags & SBUF_USRFLAGMSK);
301 * Clear an sbuf and reset its position.
304 sbuf_clear(struct sbuf *s)
307 assert_sbuf_integrity(s);
308 /* don't care if it's finished or not */
310 SBUF_CLEARFLAG(s, SBUF_FINISHED);
318 * Set the sbuf's end position to an arbitrary value.
319 * Effectively truncates the sbuf at the new position.
322 sbuf_setpos(struct sbuf *s, ssize_t pos)
325 assert_sbuf_integrity(s);
326 assert_sbuf_state(s, 0);
329 ("attempt to seek to a negative position (%jd)", (intmax_t)pos));
330 KASSERT(pos < s->s_size,
331 ("attempt to seek past end of sbuf (%jd >= %jd)",
332 (intmax_t)pos, (intmax_t)s->s_size));
333 KASSERT(!SBUF_ISSECTION(s),
334 ("attempt to seek when in a section"));
336 if (pos < 0 || pos > s->s_len)
343 * Set up a drain function and argument on an sbuf to flush data to
344 * when the sbuf buffer overflows.
347 sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx)
350 assert_sbuf_state(s, 0);
351 assert_sbuf_integrity(s);
352 KASSERT(func == s->s_drain_func || s->s_len == 0,
353 ("Cannot change drain to %p on non-empty sbuf %p", func, s));
354 s->s_drain_func = func;
355 s->s_drain_arg = ctx;
359 * Call the drain and process the return.
362 sbuf_drain(struct sbuf *s)
366 KASSERT(s->s_len > 0, ("Shouldn't drain empty sbuf %p", s));
367 KASSERT(s->s_error == 0, ("Called %s with error on %p", __func__, s));
368 if (SBUF_DODRAINTOEOR(s) && s->s_rec_off == 0)
369 return (s->s_error = EDEADLK);
370 len = s->s_drain_func(s->s_drain_arg, s->s_buf,
371 SBUF_DODRAINTOEOR(s) ? s->s_rec_off : s->s_len);
373 s->s_error = len ? -len : EDEADLK;
376 KASSERT(len > 0 && len <= s->s_len,
377 ("Bad drain amount %d for sbuf %p", len, s));
381 * Fast path for the expected case where all the data was
387 * Move the remaining characters to the beginning of the
390 memmove(s->s_buf, s->s_buf + len, s->s_len);
395 * Append bytes to an sbuf. This is the core function for appending
396 * to an sbuf and is the main place that deals with extending the
397 * buffer and marking overflow.
400 sbuf_put_bytes(struct sbuf *s, const char *buf, size_t len)
404 assert_sbuf_integrity(s);
405 assert_sbuf_state(s, 0);
410 if (SBUF_FREESPACE(s) <= 0) {
412 * If there is a drain, use it, otherwise extend the
415 if (s->s_drain_func != NULL)
417 else if (sbuf_extend(s, len > INT_MAX ? INT_MAX : len)
423 n = SBUF_FREESPACE(s);
426 memcpy(&s->s_buf[s->s_len], buf, n);
428 if (SBUF_ISSECTION(s))
436 sbuf_put_byte(struct sbuf *s, char c)
439 sbuf_put_bytes(s, &c, 1);
443 * Append a byte string to an sbuf.
446 sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
449 sbuf_put_bytes(s, buf, len);
457 * Copy a byte string from userland into an sbuf.
460 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
463 assert_sbuf_integrity(s);
464 assert_sbuf_state(s, 0);
465 KASSERT(s->s_drain_func == NULL,
466 ("Nonsensical copyin to sbuf %p with a drain", s));
472 if (len > SBUF_FREESPACE(s)) {
473 sbuf_extend(s, len - SBUF_FREESPACE(s));
474 if (SBUF_FREESPACE(s) < len)
475 len = SBUF_FREESPACE(s);
477 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
486 * Copy a byte string into an sbuf.
489 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len)
492 assert_sbuf_integrity(s);
493 assert_sbuf_state(s, 0);
496 return (sbuf_bcat(s, buf, len));
500 * Append a string to an sbuf.
503 sbuf_cat(struct sbuf *s, const char *str)
508 sbuf_put_bytes(s, str, n);
516 * Append a string from userland to an sbuf.
519 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
523 assert_sbuf_integrity(s);
524 assert_sbuf_state(s, 0);
525 KASSERT(s->s_drain_func == NULL,
526 ("Nonsensical copyin to sbuf %p with a drain", s));
532 len = SBUF_FREESPACE(s); /* XXX return 0? */
533 if (len > SBUF_FREESPACE(s)) {
535 if (SBUF_FREESPACE(s) < len)
536 len = SBUF_FREESPACE(s);
538 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
543 s->s_len += done - 1;
544 if (SBUF_ISSECTION(s))
545 s->s_sect_len += done - 1;
548 return (-1); /* XXX */
556 * Copy a string into an sbuf.
559 sbuf_cpy(struct sbuf *s, const char *str)
562 assert_sbuf_integrity(s);
563 assert_sbuf_state(s, 0);
566 return (sbuf_cat(s, str));
570 * Format the given argument list and append the resulting string to an sbuf.
575 * Append a non-NUL character to an sbuf. This prototype signature is
576 * suitable for use with kvprintf(9).
579 sbuf_putc_func(int c, void *arg)
583 sbuf_put_byte(arg, c);
587 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
590 assert_sbuf_integrity(s);
591 assert_sbuf_state(s, 0);
594 ("%s called with a NULL format string", __func__));
596 (void)kvprintf(fmt, sbuf_putc_func, s, 10, ap);
603 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
608 assert_sbuf_integrity(s);
609 assert_sbuf_state(s, 0);
612 ("%s called with a NULL format string", __func__));
618 * For the moment, there is no way to get vsnprintf(3) to hand
619 * back a character at a time, to push everything into
620 * sbuf_putc_func() as was done for the kernel.
622 * In userspace, while drains are useful, there's generally
623 * not a problem attempting to malloc(3) on out of space. So
624 * expand a userland sbuf if there is not enough room for the
625 * data produced by sbuf_[v]printf(3).
630 va_copy(ap_copy, ap);
631 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
639 if (SBUF_FREESPACE(s) >= len)
641 /* Cannot print with the current available space. */
642 if (s->s_drain_func != NULL && s->s_len > 0)
643 error = sbuf_drain(s); /* sbuf_drain() sets s_error. */
644 else if (sbuf_extend(s, len - SBUF_FREESPACE(s)) != 0)
645 s->s_error = error = ENOMEM;
646 } while (error == 0);
649 * s->s_len is the length of the string, without the terminating nul.
650 * When updating s->s_len, we must subtract 1 from the length that
651 * we passed into vsnprintf() because that length includes the
654 * vsnprintf() returns the amount that would have been copied,
655 * given sufficient space, so don't over-increment s_len.
657 if (SBUF_FREESPACE(s) < len)
658 len = SBUF_FREESPACE(s);
660 if (SBUF_ISSECTION(s))
661 s->s_sect_len += len;
663 KASSERT(s->s_len < s->s_size,
664 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
673 * Format the given arguments and append the resulting string to an sbuf.
676 sbuf_printf(struct sbuf *s, const char *fmt, ...)
682 result = sbuf_vprintf(s, fmt, ap);
688 * Append a character to an sbuf.
691 sbuf_putc(struct sbuf *s, int c)
701 * Trim whitespace characters from end of an sbuf.
704 sbuf_trim(struct sbuf *s)
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));
715 while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1])) {
717 if (SBUF_ISSECTION(s))
725 * Check if an sbuf has an error.
728 sbuf_error(const struct sbuf *s)
735 * Finish off an sbuf.
738 sbuf_finish(struct sbuf *s)
741 assert_sbuf_integrity(s);
742 assert_sbuf_state(s, 0);
744 s->s_buf[s->s_len] = '\0';
745 if (SBUF_NULINCLUDED(s))
747 if (s->s_drain_func != NULL) {
748 while (s->s_len > 0 && s->s_error == 0)
749 s->s_error = sbuf_drain(s);
751 SBUF_SETFLAG(s, SBUF_FINISHED);
755 if (s->s_error != 0) {
764 * Return a pointer to the sbuf data.
767 sbuf_data(struct sbuf *s)
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));
779 * Return the length of the sbuf data.
782 sbuf_len(struct sbuf *s)
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));
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);
800 * Clear an sbuf, free its buffer if necessary.
803 sbuf_delete(struct sbuf *s)
807 assert_sbuf_integrity(s);
808 /* don't care if it's finished or not */
810 if (SBUF_ISDYNAMIC(s))
812 isdyn = SBUF_ISDYNSTRUCT(s);
813 memset(s, 0, sizeof(*s));
819 * Check if an sbuf has been finished.
822 sbuf_done(const struct sbuf *s)
825 return (SBUF_ISFINISHED(s));
832 sbuf_start_section(struct sbuf *s, ssize_t *old_lenp)
835 assert_sbuf_integrity(s);
836 assert_sbuf_state(s, 0);
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)
843 s->s_rec_off = s->s_len;
844 SBUF_SETFLAG(s, SBUF_INSECTION);
846 KASSERT(old_lenp != NULL,
847 ("s_sect_len should be saved when starting a subsection"));
848 *old_lenp = s->s_sect_len;
854 * End the section padding to the specified length with the specified
858 sbuf_end_section(struct sbuf *s, ssize_t old_len, size_t pad, int c)
862 assert_sbuf_integrity(s);
863 assert_sbuf_state(s, 0);
864 KASSERT(SBUF_ISSECTION(s),
865 ("attempt to end a section when not in a section"));
868 len = roundup(s->s_sect_len, pad) - s->s_sect_len;
869 for (; s->s_error == 0 && len > 0; len--)
874 s->s_rec_off = s->s_sect_len = 0;
875 SBUF_CLEARFLAG(s, SBUF_INSECTION);
877 s->s_sect_len += old_len;