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 * Drain into a counter. Counts amount of data without producing output.
346 * Useful for cases like sysctl, where user may first request only size.
347 * This allows to avoid pointless allocation/freeing of large buffers.
350 sbuf_count_drain(void *arg, const char *data __unused, int len)
354 sizep = (size_t *)arg;
360 * Set up a drain function and argument on an sbuf to flush data to
361 * when the sbuf buffer overflows.
364 sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx)
367 assert_sbuf_state(s, 0);
368 assert_sbuf_integrity(s);
369 KASSERT(func == s->s_drain_func || s->s_len == 0,
370 ("Cannot change drain to %p on non-empty sbuf %p", func, s));
371 s->s_drain_func = func;
372 s->s_drain_arg = ctx;
376 * Call the drain and process the return.
379 sbuf_drain(struct sbuf *s)
383 KASSERT(s->s_len > 0, ("Shouldn't drain empty sbuf %p", s));
384 KASSERT(s->s_error == 0, ("Called %s with error on %p", __func__, s));
385 if (SBUF_DODRAINTOEOR(s) && s->s_rec_off == 0)
386 return (s->s_error = EDEADLK);
387 len = s->s_drain_func(s->s_drain_arg, s->s_buf,
388 SBUF_DODRAINTOEOR(s) ? s->s_rec_off : s->s_len);
390 s->s_error = len ? -len : EDEADLK;
393 KASSERT(len > 0 && len <= s->s_len,
394 ("Bad drain amount %d for sbuf %p", len, s));
398 * Fast path for the expected case where all the data was
404 * Move the remaining characters to the beginning of the
407 memmove(s->s_buf, s->s_buf + len, s->s_len);
412 * Append bytes to an sbuf. This is the core function for appending
413 * to an sbuf and is the main place that deals with extending the
414 * buffer and marking overflow.
417 sbuf_put_bytes(struct sbuf *s, const char *buf, size_t len)
421 assert_sbuf_integrity(s);
422 assert_sbuf_state(s, 0);
427 if (SBUF_FREESPACE(s) <= 0) {
429 * If there is a drain, use it, otherwise extend the
432 if (s->s_drain_func != NULL)
434 else if (sbuf_extend(s, len > INT_MAX ? INT_MAX : len)
440 n = SBUF_FREESPACE(s);
443 memcpy(&s->s_buf[s->s_len], buf, n);
445 if (SBUF_ISSECTION(s))
453 sbuf_put_byte(struct sbuf *s, char c)
456 sbuf_put_bytes(s, &c, 1);
460 * Append a byte string to an sbuf.
463 sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
466 sbuf_put_bytes(s, buf, len);
474 * Copy a byte string from userland into an sbuf.
477 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
480 assert_sbuf_integrity(s);
481 assert_sbuf_state(s, 0);
482 KASSERT(s->s_drain_func == NULL,
483 ("Nonsensical copyin to sbuf %p with a drain", s));
489 if (len > SBUF_FREESPACE(s)) {
490 sbuf_extend(s, len - SBUF_FREESPACE(s));
491 if (SBUF_FREESPACE(s) < len)
492 len = SBUF_FREESPACE(s);
494 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
503 * Copy a byte string into an sbuf.
506 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len)
509 assert_sbuf_integrity(s);
510 assert_sbuf_state(s, 0);
513 return (sbuf_bcat(s, buf, len));
517 * Append a string to an sbuf.
520 sbuf_cat(struct sbuf *s, const char *str)
525 sbuf_put_bytes(s, str, n);
533 * Append a string from userland to an sbuf.
536 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
540 assert_sbuf_integrity(s);
541 assert_sbuf_state(s, 0);
542 KASSERT(s->s_drain_func == NULL,
543 ("Nonsensical copyin to sbuf %p with a drain", s));
549 len = SBUF_FREESPACE(s); /* XXX return 0? */
550 if (len > SBUF_FREESPACE(s)) {
552 if (SBUF_FREESPACE(s) < len)
553 len = SBUF_FREESPACE(s);
555 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
560 s->s_len += done - 1;
561 if (SBUF_ISSECTION(s))
562 s->s_sect_len += done - 1;
565 return (-1); /* XXX */
573 * Copy a string into an sbuf.
576 sbuf_cpy(struct sbuf *s, const char *str)
579 assert_sbuf_integrity(s);
580 assert_sbuf_state(s, 0);
583 return (sbuf_cat(s, str));
587 * Format the given argument list and append the resulting string to an sbuf.
592 * Append a non-NUL character to an sbuf. This prototype signature is
593 * suitable for use with kvprintf(9).
596 sbuf_putc_func(int c, void *arg)
600 sbuf_put_byte(arg, c);
604 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
607 assert_sbuf_integrity(s);
608 assert_sbuf_state(s, 0);
611 ("%s called with a NULL format string", __func__));
613 (void)kvprintf(fmt, sbuf_putc_func, s, 10, ap);
620 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
625 assert_sbuf_integrity(s);
626 assert_sbuf_state(s, 0);
629 ("%s called with a NULL format string", __func__));
635 * For the moment, there is no way to get vsnprintf(3) to hand
636 * back a character at a time, to push everything into
637 * sbuf_putc_func() as was done for the kernel.
639 * In userspace, while drains are useful, there's generally
640 * not a problem attempting to malloc(3) on out of space. So
641 * expand a userland sbuf if there is not enough room for the
642 * data produced by sbuf_[v]printf(3).
647 va_copy(ap_copy, ap);
648 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
656 if (SBUF_FREESPACE(s) >= len)
658 /* Cannot print with the current available space. */
659 if (s->s_drain_func != NULL && s->s_len > 0)
660 error = sbuf_drain(s); /* sbuf_drain() sets s_error. */
661 else if (sbuf_extend(s, len - SBUF_FREESPACE(s)) != 0)
662 s->s_error = error = ENOMEM;
663 } while (error == 0);
666 * s->s_len is the length of the string, without the terminating nul.
667 * When updating s->s_len, we must subtract 1 from the length that
668 * we passed into vsnprintf() because that length includes the
671 * vsnprintf() returns the amount that would have been copied,
672 * given sufficient space, so don't over-increment s_len.
674 if (SBUF_FREESPACE(s) < len)
675 len = SBUF_FREESPACE(s);
677 if (SBUF_ISSECTION(s))
678 s->s_sect_len += len;
680 KASSERT(s->s_len < s->s_size,
681 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
690 * Format the given arguments and append the resulting string to an sbuf.
693 sbuf_printf(struct sbuf *s, const char *fmt, ...)
699 result = sbuf_vprintf(s, fmt, ap);
705 * Append a character to an sbuf.
708 sbuf_putc(struct sbuf *s, int c)
718 * Trim whitespace characters from end of an sbuf.
721 sbuf_trim(struct sbuf *s)
724 assert_sbuf_integrity(s);
725 assert_sbuf_state(s, 0);
726 KASSERT(s->s_drain_func == NULL,
727 ("%s makes no sense on sbuf %p with drain", __func__, s));
732 while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1])) {
734 if (SBUF_ISSECTION(s))
742 * Check if an sbuf has an error.
745 sbuf_error(const struct sbuf *s)
752 * Finish off an sbuf.
755 sbuf_finish(struct sbuf *s)
758 assert_sbuf_integrity(s);
759 assert_sbuf_state(s, 0);
761 s->s_buf[s->s_len] = '\0';
762 if (SBUF_NULINCLUDED(s))
764 if (s->s_drain_func != NULL) {
765 while (s->s_len > 0 && s->s_error == 0)
766 s->s_error = sbuf_drain(s);
768 SBUF_SETFLAG(s, SBUF_FINISHED);
772 if (s->s_error != 0) {
781 * Return a pointer to the sbuf data.
784 sbuf_data(struct sbuf *s)
787 assert_sbuf_integrity(s);
788 assert_sbuf_state(s, SBUF_FINISHED);
789 KASSERT(s->s_drain_func == NULL,
790 ("%s makes no sense on sbuf %p with drain", __func__, s));
796 * Return the length of the sbuf data.
799 sbuf_len(struct sbuf *s)
802 assert_sbuf_integrity(s);
803 /* don't care if it's finished or not */
804 KASSERT(s->s_drain_func == NULL,
805 ("%s makes no sense on sbuf %p with drain", __func__, s));
810 /* If finished, nulterm is already in len, else add one. */
811 if (SBUF_NULINCLUDED(s) && !SBUF_ISFINISHED(s))
812 return (s->s_len + 1);
817 * Clear an sbuf, free its buffer if necessary.
820 sbuf_delete(struct sbuf *s)
824 assert_sbuf_integrity(s);
825 /* don't care if it's finished or not */
827 if (SBUF_ISDYNAMIC(s))
829 isdyn = SBUF_ISDYNSTRUCT(s);
830 memset(s, 0, sizeof(*s));
836 * Check if an sbuf has been finished.
839 sbuf_done(const struct sbuf *s)
842 return (SBUF_ISFINISHED(s));
849 sbuf_start_section(struct sbuf *s, ssize_t *old_lenp)
852 assert_sbuf_integrity(s);
853 assert_sbuf_state(s, 0);
855 if (!SBUF_ISSECTION(s)) {
856 KASSERT(s->s_sect_len == 0,
857 ("s_sect_len != 0 when starting a section"));
858 if (old_lenp != NULL)
860 s->s_rec_off = s->s_len;
861 SBUF_SETFLAG(s, SBUF_INSECTION);
863 KASSERT(old_lenp != NULL,
864 ("s_sect_len should be saved when starting a subsection"));
865 *old_lenp = s->s_sect_len;
871 * End the section padding to the specified length with the specified
875 sbuf_end_section(struct sbuf *s, ssize_t old_len, size_t pad, int c)
879 assert_sbuf_integrity(s);
880 assert_sbuf_state(s, 0);
881 KASSERT(SBUF_ISSECTION(s),
882 ("attempt to end a section when not in a section"));
885 len = roundup(s->s_sect_len, pad) - s->s_sect_len;
886 for (; s->s_error == 0 && len > 0; len--)
891 s->s_rec_off = s->s_sect_len = 0;
892 SBUF_CLEARFLAG(s, SBUF_INSECTION);
894 s->s_sect_len += old_len;