2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2000-2008 Poul-Henning Kamp
5 * Copyright (c) 2000-2008 Dag-Erling Coïdan Smørgrav
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer
13 * in this position and unchanged.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
37 #include <sys/ctype.h>
38 #include <sys/errno.h>
39 #include <sys/kernel.h>
40 #include <sys/limits.h>
41 #include <sys/malloc.h>
42 #include <sys/systm.h>
44 #include <machine/stdarg.h>
58 static MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers");
59 #define SBMALLOC(size) malloc(size, M_SBUF, M_WAITOK|M_ZERO)
60 #define SBFREE(buf) free(buf, M_SBUF)
63 #define SBMALLOC(size) calloc(1, size)
64 #define SBFREE(buf) free(buf)
70 #define SBUF_ISDYNAMIC(s) ((s)->s_flags & SBUF_DYNAMIC)
71 #define SBUF_ISDYNSTRUCT(s) ((s)->s_flags & SBUF_DYNSTRUCT)
72 #define SBUF_ISFINISHED(s) ((s)->s_flags & SBUF_FINISHED)
73 #define SBUF_HASROOM(s) ((s)->s_len < (s)->s_size - 1)
74 #define SBUF_FREESPACE(s) ((s)->s_size - ((s)->s_len + 1))
75 #define SBUF_CANEXTEND(s) ((s)->s_flags & SBUF_AUTOEXTEND)
76 #define SBUF_ISSECTION(s) ((s)->s_flags & SBUF_INSECTION)
77 #define SBUF_NULINCLUDED(s) ((s)->s_flags & SBUF_INCLUDENUL)
78 #define SBUF_ISDRAINTOEOR(s) ((s)->s_flags & SBUF_DRAINTOEOR)
79 #define SBUF_DODRAINTOEOR(s) (SBUF_ISSECTION(s) && SBUF_ISDRAINTOEOR(s))
84 #define SBUF_SETFLAG(s, f) do { (s)->s_flags |= (f); } while (0)
85 #define SBUF_CLEARFLAG(s, f) do { (s)->s_flags &= ~(f); } while (0)
87 #define SBUF_MINSIZE 2 /* Min is 1 byte + nulterm. */
88 #define SBUF_MINEXTENDSIZE 16 /* Should be power of 2. */
91 #define SBUF_MAXEXTENDSIZE PAGE_SIZE
92 #define SBUF_MAXEXTENDINCR PAGE_SIZE
94 #define SBUF_MAXEXTENDSIZE 4096
95 #define SBUF_MAXEXTENDINCR 4096
101 #if defined(_KERNEL) && defined(INVARIANTS)
104 _assert_sbuf_integrity(const char *fun, struct sbuf *s)
108 ("%s called with a NULL sbuf pointer", fun));
109 KASSERT(s->s_buf != NULL,
110 ("%s called with uninitialized or corrupt sbuf", fun));
111 if (SBUF_ISFINISHED(s) && SBUF_NULINCLUDED(s)) {
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));
116 KASSERT(s->s_len < s->s_size,
117 ("wrote past end of sbuf (%jd >= %jd)",
118 (intmax_t)s->s_len, (intmax_t)s->s_size));
123 _assert_sbuf_state(const char *fun, struct sbuf *s, int state)
126 KASSERT((s->s_flags & SBUF_FINISHED) == state,
127 ("%s called with %sfinished or corrupt sbuf", fun,
128 (state ? "un" : "")));
131 #define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s))
132 #define assert_sbuf_state(s, i) _assert_sbuf_state(__func__, (s), (i))
134 #else /* _KERNEL && INVARIANTS */
136 #define assert_sbuf_integrity(s) do { } while (0)
137 #define assert_sbuf_state(s, i) do { } while (0)
139 #endif /* _KERNEL && INVARIANTS */
142 CTASSERT(powerof2(SBUF_MAXEXTENDSIZE));
143 CTASSERT(powerof2(SBUF_MAXEXTENDINCR));
147 sbuf_extendsize(int size)
151 if (size < (int)SBUF_MAXEXTENDSIZE) {
152 newsize = SBUF_MINEXTENDSIZE;
153 while (newsize < size)
156 newsize = roundup2(size, SBUF_MAXEXTENDINCR);
158 KASSERT(newsize >= size, ("%s: %d < %d\n", __func__, newsize, size));
166 sbuf_extend(struct sbuf *s, int addlen)
171 if (!SBUF_CANEXTEND(s))
173 newsize = sbuf_extendsize(s->s_size + addlen);
174 newbuf = SBMALLOC(newsize);
177 memcpy(newbuf, s->s_buf, s->s_size);
178 if (SBUF_ISDYNAMIC(s))
181 SBUF_SETFLAG(s, SBUF_DYNAMIC);
188 * Initialize the internals of an sbuf.
189 * If buf is non-NULL, it points to a static or already-allocated string
190 * big enough to hold at least length characters.
193 sbuf_newbuf(struct sbuf *s, char *buf, int length, int flags)
196 memset(s, 0, sizeof(*s));
201 if ((s->s_flags & SBUF_AUTOEXTEND) == 0) {
202 KASSERT(s->s_size >= SBUF_MINSIZE,
203 ("attempt to create an sbuf smaller than %d bytes",
207 if (s->s_buf != NULL)
210 if ((flags & SBUF_AUTOEXTEND) != 0)
211 s->s_size = sbuf_extendsize(s->s_size);
213 s->s_buf = SBMALLOC(s->s_size);
214 if (s->s_buf == NULL)
216 SBUF_SETFLAG(s, SBUF_DYNAMIC);
221 * Initialize an sbuf.
222 * If buf is non-NULL, it points to a static or already-allocated string
223 * big enough to hold at least length characters.
226 sbuf_new(struct sbuf *s, char *buf, int length, int flags)
230 ("attempt to create an sbuf of negative length (%d)", length));
231 KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
232 ("%s called with invalid flags", __func__));
234 flags &= SBUF_USRFLAGMSK;
236 return (sbuf_newbuf(s, buf, length, flags));
238 s = SBMALLOC(sizeof(*s));
241 if (sbuf_newbuf(s, buf, length, flags) == NULL) {
245 SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
251 * Create an sbuf with uio data
254 sbuf_uionew(struct sbuf *s, struct uio *uio, int *error)
258 ("%s called with NULL uio pointer", __func__));
259 KASSERT(error != NULL,
260 ("%s called with NULL error pointer", __func__));
262 s = sbuf_new(s, NULL, uio->uio_resid + 1, 0);
267 *error = uiomove(s->s_buf, uio->uio_resid, uio);
272 s->s_len = s->s_size - 1;
273 if (SBUF_ISSECTION(s))
274 s->s_sect_len = s->s_size - 1;
281 sbuf_get_flags(struct sbuf *s)
284 return (s->s_flags & SBUF_USRFLAGMSK);
288 sbuf_clear_flags(struct sbuf *s, int flags)
291 s->s_flags &= ~(flags & SBUF_USRFLAGMSK);
295 sbuf_set_flags(struct sbuf *s, int flags)
299 s->s_flags |= (flags & SBUF_USRFLAGMSK);
303 * Clear an sbuf and reset its position.
306 sbuf_clear(struct sbuf *s)
309 assert_sbuf_integrity(s);
310 /* don't care if it's finished or not */
312 SBUF_CLEARFLAG(s, SBUF_FINISHED);
320 * Set the sbuf's end position to an arbitrary value.
321 * Effectively truncates the sbuf at the new position.
324 sbuf_setpos(struct sbuf *s, ssize_t pos)
327 assert_sbuf_integrity(s);
328 assert_sbuf_state(s, 0);
331 ("attempt to seek to a negative position (%jd)", (intmax_t)pos));
332 KASSERT(pos < s->s_size,
333 ("attempt to seek past end of sbuf (%jd >= %jd)",
334 (intmax_t)pos, (intmax_t)s->s_size));
335 KASSERT(!SBUF_ISSECTION(s),
336 ("attempt to seek when in a section"));
338 if (pos < 0 || pos > s->s_len)
345 * Set up a drain function and argument on an sbuf to flush data to
346 * when the sbuf buffer overflows.
349 sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx)
352 assert_sbuf_state(s, 0);
353 assert_sbuf_integrity(s);
354 KASSERT(func == s->s_drain_func || s->s_len == 0,
355 ("Cannot change drain to %p on non-empty sbuf %p", func, s));
356 s->s_drain_func = func;
357 s->s_drain_arg = ctx;
361 * Call the drain and process the return.
364 sbuf_drain(struct sbuf *s)
368 KASSERT(s->s_len > 0, ("Shouldn't drain empty sbuf %p", s));
369 KASSERT(s->s_error == 0, ("Called %s with error on %p", __func__, s));
370 if (SBUF_DODRAINTOEOR(s) && s->s_rec_off == 0)
371 return (s->s_error = EDEADLK);
372 len = s->s_drain_func(s->s_drain_arg, s->s_buf,
373 SBUF_DODRAINTOEOR(s) ? s->s_rec_off : s->s_len);
375 s->s_error = len ? -len : EDEADLK;
378 KASSERT(len > 0 && len <= s->s_len,
379 ("Bad drain amount %d for sbuf %p", len, s));
383 * Fast path for the expected case where all the data was
389 * Move the remaining characters to the beginning of the
392 memmove(s->s_buf, s->s_buf + len, s->s_len);
397 * Append bytes to an sbuf. This is the core function for appending
398 * to an sbuf and is the main place that deals with extending the
399 * buffer and marking overflow.
402 sbuf_put_bytes(struct sbuf *s, const char *buf, size_t len)
406 assert_sbuf_integrity(s);
407 assert_sbuf_state(s, 0);
412 if (SBUF_FREESPACE(s) <= 0) {
414 * If there is a drain, use it, otherwise extend the
417 if (s->s_drain_func != NULL)
419 else if (sbuf_extend(s, len > INT_MAX ? INT_MAX : len)
425 n = SBUF_FREESPACE(s);
428 memcpy(&s->s_buf[s->s_len], buf, n);
430 if (SBUF_ISSECTION(s))
438 sbuf_put_byte(struct sbuf *s, char c)
441 sbuf_put_bytes(s, &c, 1);
445 * Append a byte string to an sbuf.
448 sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
451 sbuf_put_bytes(s, buf, len);
459 * Copy a byte string from userland into an sbuf.
462 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
465 assert_sbuf_integrity(s);
466 assert_sbuf_state(s, 0);
467 KASSERT(s->s_drain_func == NULL,
468 ("Nonsensical copyin to sbuf %p with a drain", s));
474 if (len > SBUF_FREESPACE(s)) {
475 sbuf_extend(s, len - SBUF_FREESPACE(s));
476 if (SBUF_FREESPACE(s) < len)
477 len = SBUF_FREESPACE(s);
479 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
488 * Copy a byte string into an sbuf.
491 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len)
494 assert_sbuf_integrity(s);
495 assert_sbuf_state(s, 0);
498 return (sbuf_bcat(s, buf, len));
502 * Append a string to an sbuf.
505 sbuf_cat(struct sbuf *s, const char *str)
510 sbuf_put_bytes(s, str, n);
518 * Append a string from userland to an sbuf.
521 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
525 assert_sbuf_integrity(s);
526 assert_sbuf_state(s, 0);
527 KASSERT(s->s_drain_func == NULL,
528 ("Nonsensical copyin to sbuf %p with a drain", s));
534 len = SBUF_FREESPACE(s); /* XXX return 0? */
535 if (len > SBUF_FREESPACE(s)) {
537 if (SBUF_FREESPACE(s) < len)
538 len = SBUF_FREESPACE(s);
540 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
545 s->s_len += done - 1;
546 if (SBUF_ISSECTION(s))
547 s->s_sect_len += done - 1;
550 return (-1); /* XXX */
558 * Copy a string into an sbuf.
561 sbuf_cpy(struct sbuf *s, const char *str)
564 assert_sbuf_integrity(s);
565 assert_sbuf_state(s, 0);
568 return (sbuf_cat(s, str));
572 * Format the given argument list and append the resulting string to an sbuf.
577 * Append a non-NUL character to an sbuf. This prototype signature is
578 * suitable for use with kvprintf(9).
581 sbuf_putc_func(int c, void *arg)
585 sbuf_put_byte(arg, c);
589 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
592 assert_sbuf_integrity(s);
593 assert_sbuf_state(s, 0);
596 ("%s called with a NULL format string", __func__));
598 (void)kvprintf(fmt, sbuf_putc_func, s, 10, ap);
605 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
610 assert_sbuf_integrity(s);
611 assert_sbuf_state(s, 0);
614 ("%s called with a NULL format string", __func__));
620 * For the moment, there is no way to get vsnprintf(3) to hand
621 * back a character at a time, to push everything into
622 * sbuf_putc_func() as was done for the kernel.
624 * In userspace, while drains are useful, there's generally
625 * not a problem attempting to malloc(3) on out of space. So
626 * expand a userland sbuf if there is not enough room for the
627 * data produced by sbuf_[v]printf(3).
632 va_copy(ap_copy, ap);
633 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
641 if (SBUF_FREESPACE(s) >= len)
643 /* Cannot print with the current available space. */
644 if (s->s_drain_func != NULL && s->s_len > 0)
645 error = sbuf_drain(s); /* sbuf_drain() sets s_error. */
646 else if (sbuf_extend(s, len - SBUF_FREESPACE(s)) != 0)
647 s->s_error = error = ENOMEM;
648 } while (error == 0);
651 * s->s_len is the length of the string, without the terminating nul.
652 * When updating s->s_len, we must subtract 1 from the length that
653 * we passed into vsnprintf() because that length includes the
656 * vsnprintf() returns the amount that would have been copied,
657 * given sufficient space, so don't over-increment s_len.
659 if (SBUF_FREESPACE(s) < len)
660 len = SBUF_FREESPACE(s);
662 if (SBUF_ISSECTION(s))
663 s->s_sect_len += len;
665 KASSERT(s->s_len < s->s_size,
666 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
675 * Format the given arguments and append the resulting string to an sbuf.
678 sbuf_printf(struct sbuf *s, const char *fmt, ...)
684 result = sbuf_vprintf(s, fmt, ap);
690 * Append a character to an sbuf.
693 sbuf_putc(struct sbuf *s, int c)
703 * Trim whitespace characters from end of an sbuf.
706 sbuf_trim(struct sbuf *s)
709 assert_sbuf_integrity(s);
710 assert_sbuf_state(s, 0);
711 KASSERT(s->s_drain_func == NULL,
712 ("%s makes no sense on sbuf %p with drain", __func__, s));
717 while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1])) {
719 if (SBUF_ISSECTION(s))
727 * Check if an sbuf has an error.
730 sbuf_error(const struct sbuf *s)
737 * Finish off an sbuf.
740 sbuf_finish(struct sbuf *s)
743 assert_sbuf_integrity(s);
744 assert_sbuf_state(s, 0);
746 s->s_buf[s->s_len] = '\0';
747 if (SBUF_NULINCLUDED(s))
749 if (s->s_drain_func != NULL) {
750 while (s->s_len > 0 && s->s_error == 0)
751 s->s_error = sbuf_drain(s);
753 SBUF_SETFLAG(s, SBUF_FINISHED);
757 if (s->s_error != 0) {
766 * Return a pointer to the sbuf data.
769 sbuf_data(struct sbuf *s)
772 assert_sbuf_integrity(s);
773 assert_sbuf_state(s, SBUF_FINISHED);
774 KASSERT(s->s_drain_func == NULL,
775 ("%s makes no sense on sbuf %p with drain", __func__, s));
781 * Return the length of the sbuf data.
784 sbuf_len(struct sbuf *s)
787 assert_sbuf_integrity(s);
788 /* don't care if it's finished or not */
789 KASSERT(s->s_drain_func == NULL,
790 ("%s makes no sense on sbuf %p with drain", __func__, s));
795 /* If finished, nulterm is already in len, else add one. */
796 if (SBUF_NULINCLUDED(s) && !SBUF_ISFINISHED(s))
797 return (s->s_len + 1);
802 * Clear an sbuf, free its buffer if necessary.
805 sbuf_delete(struct sbuf *s)
809 assert_sbuf_integrity(s);
810 /* don't care if it's finished or not */
812 if (SBUF_ISDYNAMIC(s))
814 isdyn = SBUF_ISDYNSTRUCT(s);
815 memset(s, 0, sizeof(*s));
821 * Check if an sbuf has been finished.
824 sbuf_done(const struct sbuf *s)
827 return (SBUF_ISFINISHED(s));
834 sbuf_start_section(struct sbuf *s, ssize_t *old_lenp)
837 assert_sbuf_integrity(s);
838 assert_sbuf_state(s, 0);
840 if (!SBUF_ISSECTION(s)) {
841 KASSERT(s->s_sect_len == 0,
842 ("s_sect_len != 0 when starting a section"));
843 if (old_lenp != NULL)
845 s->s_rec_off = s->s_len;
846 SBUF_SETFLAG(s, SBUF_INSECTION);
848 KASSERT(old_lenp != NULL,
849 ("s_sect_len should be saved when starting a subsection"));
850 *old_lenp = s->s_sect_len;
856 * End the section padding to the specified length with the specified
860 sbuf_end_section(struct sbuf *s, ssize_t old_len, size_t pad, int c)
864 assert_sbuf_integrity(s);
865 assert_sbuf_state(s, 0);
866 KASSERT(SBUF_ISSECTION(s),
867 ("attempt to end a section when not in a section"));
870 len = roundup(s->s_sect_len, pad) - s->s_sect_len;
871 for (; s->s_error == 0 && len > 0; len--)
876 s->s_rec_off = s->s_sect_len = 0;
877 SBUF_CLEARFLAG(s, SBUF_INSECTION);
879 s->s_sect_len += old_len;