2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 2000-2008 Poul-Henning Kamp
5 * Copyright (c) 2000-2008 Dag-Erling 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/param.h>
34 #include <sys/ctype.h>
35 #include <sys/errno.h>
36 #include <sys/kernel.h>
37 #include <sys/limits.h>
38 #include <sys/malloc.h>
39 #include <sys/systm.h>
41 #include <machine/stdarg.h>
55 static MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers");
56 #define SBMALLOC(size, flags) malloc(size, M_SBUF, (flags) | M_ZERO)
57 #define SBFREE(buf) free(buf, M_SBUF)
60 #define SBMALLOC(size, flags) calloc(1, size)
61 #define SBFREE(buf) free(buf)
67 #define SBUF_ISDYNAMIC(s) ((s)->s_flags & SBUF_DYNAMIC)
68 #define SBUF_ISDYNSTRUCT(s) ((s)->s_flags & SBUF_DYNSTRUCT)
69 #define SBUF_ISFINISHED(s) ((s)->s_flags & SBUF_FINISHED)
70 #define SBUF_ISDRAINATEOL(s) ((s)->s_flags & SBUF_DRAINATEOL)
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))
78 #define SBUF_MALLOCFLAG(s) \
79 (((s)->s_flags & SBUF_NOWAIT) ? M_NOWAIT : M_WAITOK)
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, SBUF_MALLOCFLAG(s));
177 memcpy(newbuf, s->s_buf, s->s_size);
178 if (SBUF_ISDYNAMIC(s))
181 SBUF_SETFLAG(s, SBUF_DYNAMIC);
188 * Initialize 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_new(struct sbuf *s, char *buf, int length, int flags)
197 ("attempt to create an sbuf of negative length (%d)", length));
198 KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
199 ("%s called with invalid flags", __func__));
200 KASSERT((flags & SBUF_AUTOEXTEND) || length >= SBUF_MINSIZE,
201 ("sbuf buffer %d smaller than minimum %d bytes", length,
204 flags &= SBUF_USRFLAGMSK;
207 * Allocate 'DYNSTRUCT' sbuf from the heap, if NULL 's' was provided.
210 s = SBMALLOC(sizeof(*s),
211 (flags & SBUF_NOWAIT) ? M_NOWAIT : M_WAITOK);
214 SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
217 * DYNSTRUCT SBMALLOC sbufs are allocated with M_ZERO, but
218 * user-provided sbuf objects must be initialized.
220 memset(s, 0, sizeof(*s));
227 * Never-written sbufs do not need \n termination.
229 SBUF_SETFLAG(s, SBUF_DRAINATEOL);
232 * Allocate DYNAMIC, i.e., heap data buffer backing the sbuf, if no
233 * buffer was provided.
235 if (s->s_buf == NULL) {
236 if (SBUF_CANEXTEND(s))
237 s->s_size = sbuf_extendsize(s->s_size);
238 s->s_buf = SBMALLOC(s->s_size, SBUF_MALLOCFLAG(s));
239 if (s->s_buf == NULL)
241 SBUF_SETFLAG(s, SBUF_DYNAMIC);
245 if (s != NULL && s->s_buf == NULL) {
246 if (SBUF_ISDYNSTRUCT(s))
255 * Create an sbuf with uio data
258 sbuf_uionew(struct sbuf *s, struct uio *uio, int *error)
262 ("%s called with NULL uio pointer", __func__));
263 KASSERT(error != NULL,
264 ("%s called with NULL error pointer", __func__));
266 if (uio->uio_resid >= INT_MAX || uio->uio_resid < SBUF_MINSIZE - 1) {
270 s = sbuf_new(s, NULL, uio->uio_resid + 1, 0);
275 *error = uiomove(s->s_buf, uio->uio_resid, uio);
280 s->s_len = s->s_size - 1;
281 if (SBUF_ISSECTION(s))
282 s->s_sect_len = s->s_size - 1;
289 sbuf_get_flags(struct sbuf *s)
292 return (s->s_flags & SBUF_USRFLAGMSK);
296 sbuf_clear_flags(struct sbuf *s, int flags)
299 s->s_flags &= ~(flags & SBUF_USRFLAGMSK);
303 sbuf_set_flags(struct sbuf *s, int flags)
306 s->s_flags |= (flags & SBUF_USRFLAGMSK);
310 * Clear an sbuf and reset its position.
313 sbuf_clear(struct sbuf *s)
316 assert_sbuf_integrity(s);
317 /* don't care if it's finished or not */
318 KASSERT(s->s_drain_func == NULL,
319 ("%s makes no sense on sbuf %p with drain", __func__, s));
321 SBUF_CLEARFLAG(s, SBUF_FINISHED);
329 * Set the sbuf's end position to an arbitrary value.
330 * Effectively truncates the sbuf at the new position.
333 sbuf_setpos(struct sbuf *s, ssize_t pos)
336 assert_sbuf_integrity(s);
337 assert_sbuf_state(s, 0);
340 ("attempt to seek to a negative position (%jd)", (intmax_t)pos));
341 KASSERT(pos < s->s_size,
342 ("attempt to seek past end of sbuf (%jd >= %jd)",
343 (intmax_t)pos, (intmax_t)s->s_size));
344 KASSERT(!SBUF_ISSECTION(s),
345 ("attempt to seek when in a section"));
347 if (pos < 0 || pos > s->s_len)
354 * Drain into a counter. Counts amount of data without producing output.
355 * Useful for cases like sysctl, where user may first request only size.
356 * This allows to avoid pointless allocation/freeing of large buffers.
359 sbuf_count_drain(void *arg, const char *data __unused, int len)
363 sizep = (size_t *)arg;
369 * Set up a drain function and argument on an sbuf to flush data to
370 * when the sbuf buffer overflows.
373 sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx)
376 assert_sbuf_state(s, 0);
377 assert_sbuf_integrity(s);
378 KASSERT(func == s->s_drain_func || s->s_len == 0,
379 ("Cannot change drain to %p on non-empty sbuf %p", func, s));
380 s->s_drain_func = func;
381 s->s_drain_arg = ctx;
385 * Call the drain and process the return.
388 sbuf_drain(struct sbuf *s)
393 * Immediately return when no work to do,
394 * or an error has already been accumulated.
396 if ((s->s_len == 0) || (s->s_error != 0))
399 if (SBUF_DODRAINTOEOR(s) && s->s_rec_off == 0)
400 return (s->s_error = EDEADLK);
401 len = s->s_drain_func(s->s_drain_arg, s->s_buf,
402 SBUF_DODRAINTOEOR(s) ? s->s_rec_off : s->s_len);
404 s->s_error = len ? -len : EDEADLK;
407 KASSERT(len > 0 && len <= s->s_len,
408 ("Bad drain amount %d for sbuf %p", len, s));
412 * Fast path for the expected case where all the data was
417 * When the s_buf is entirely drained, we need to remember if
418 * the last character was a '\n' or not for
419 * sbuf_nl_terminate().
421 if (s->s_buf[len - 1] == '\n')
422 SBUF_SETFLAG(s, SBUF_DRAINATEOL);
424 SBUF_CLEARFLAG(s, SBUF_DRAINATEOL);
428 * Move the remaining characters to the beginning of the
431 memmove(s->s_buf, s->s_buf + len, s->s_len);
436 * Append bytes to an sbuf. This is the core function for appending
437 * to an sbuf and is the main place that deals with extending the
438 * buffer and marking overflow.
441 sbuf_put_bytes(struct sbuf *s, const char *buf, size_t len)
445 assert_sbuf_integrity(s);
446 assert_sbuf_state(s, 0);
451 if (SBUF_FREESPACE(s) <= 0) {
453 * If there is a drain, use it, otherwise extend the
456 if (s->s_drain_func != NULL)
458 else if (sbuf_extend(s, len > INT_MAX ? INT_MAX : len)
464 n = SBUF_FREESPACE(s);
467 memcpy(&s->s_buf[s->s_len], buf, n);
469 if (SBUF_ISSECTION(s))
477 sbuf_put_byte(struct sbuf *s, char c)
480 assert_sbuf_integrity(s);
481 assert_sbuf_state(s, 0);
483 if (__predict_false(s->s_error != 0))
485 if (__predict_false(SBUF_FREESPACE(s) <= 0)) {
487 * If there is a drain, use it, otherwise extend the
490 if (s->s_drain_func != NULL)
492 else if (sbuf_extend(s, 1) < 0)
497 s->s_buf[s->s_len++] = c;
498 if (SBUF_ISSECTION(s))
503 * Append a byte string to an sbuf.
506 sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
509 sbuf_put_bytes(s, buf, len);
517 * Copy a byte string from userland into an sbuf.
520 sbuf_bcopyin(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 if (len > SBUF_FREESPACE(s)) {
533 sbuf_extend(s, len - SBUF_FREESPACE(s));
534 if (SBUF_FREESPACE(s) < len)
535 len = SBUF_FREESPACE(s);
537 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
546 * Copy a byte string into an sbuf.
549 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len)
552 assert_sbuf_integrity(s);
553 assert_sbuf_state(s, 0);
556 return (sbuf_bcat(s, buf, len));
560 * Append a string to an sbuf.
563 sbuf_cat(struct sbuf *s, const char *str)
568 sbuf_put_bytes(s, str, n);
576 * Append a string from userland to an sbuf.
579 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
583 assert_sbuf_integrity(s);
584 assert_sbuf_state(s, 0);
585 KASSERT(s->s_drain_func == NULL,
586 ("Nonsensical copyin to sbuf %p with a drain", s));
592 len = SBUF_FREESPACE(s); /* XXX return 0? */
593 if (len > SBUF_FREESPACE(s)) {
595 if (SBUF_FREESPACE(s) < len)
596 len = SBUF_FREESPACE(s);
598 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
603 s->s_len += done - 1;
604 if (SBUF_ISSECTION(s))
605 s->s_sect_len += done - 1;
608 return (-1); /* XXX */
616 * Copy a string into an sbuf.
619 sbuf_cpy(struct sbuf *s, const char *str)
622 assert_sbuf_integrity(s);
623 assert_sbuf_state(s, 0);
626 return (sbuf_cat(s, str));
630 * Format the given argument list and append the resulting string to an sbuf.
635 * Append a non-NUL character to an sbuf. This prototype signature is
636 * suitable for use with kvprintf(9).
639 sbuf_putc_func(int c, void *arg)
642 if (__predict_true(c != '\0'))
643 sbuf_put_byte(arg, c);
647 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
650 assert_sbuf_integrity(s);
651 assert_sbuf_state(s, 0);
654 ("%s called with a NULL format string", __func__));
656 (void)kvprintf(fmt, sbuf_putc_func, s, 10, ap);
663 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
668 assert_sbuf_integrity(s);
669 assert_sbuf_state(s, 0);
672 ("%s called with a NULL format string", __func__));
678 * For the moment, there is no way to get vsnprintf(3) to hand
679 * back a character at a time, to push everything into
680 * sbuf_putc_func() as was done for the kernel.
682 * In userspace, while drains are useful, there's generally
683 * not a problem attempting to malloc(3) on out of space. So
684 * expand a userland sbuf if there is not enough room for the
685 * data produced by sbuf_[v]printf(3).
690 va_copy(ap_copy, ap);
691 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
699 if (SBUF_FREESPACE(s) >= len)
701 /* Cannot print with the current available space. */
702 if (s->s_drain_func != NULL && s->s_len > 0)
703 error = sbuf_drain(s); /* sbuf_drain() sets s_error. */
704 else if (sbuf_extend(s, len - SBUF_FREESPACE(s)) != 0)
705 s->s_error = error = ENOMEM;
706 } while (error == 0);
709 * s->s_len is the length of the string, without the terminating nul.
710 * When updating s->s_len, we must subtract 1 from the length that
711 * we passed into vsnprintf() because that length includes the
714 * vsnprintf() returns the amount that would have been copied,
715 * given sufficient space, so don't over-increment s_len.
717 if (SBUF_FREESPACE(s) < len)
718 len = SBUF_FREESPACE(s);
720 if (SBUF_ISSECTION(s))
721 s->s_sect_len += len;
723 KASSERT(s->s_len < s->s_size,
724 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
733 * Format the given arguments and append the resulting string to an sbuf.
736 sbuf_printf(struct sbuf *s, const char *fmt, ...)
742 result = sbuf_vprintf(s, fmt, ap);
748 * Append a character to an sbuf.
751 sbuf_putc(struct sbuf *s, int c)
761 * Append a trailing newline to a non-empty sbuf, if one is not already
762 * present. Handles sbufs with drain functions correctly.
765 sbuf_nl_terminate(struct sbuf *s)
768 assert_sbuf_integrity(s);
769 assert_sbuf_state(s, 0);
772 * If the s_buf isn't empty, the last byte is simply s_buf[s_len - 1].
774 * If the s_buf is empty because a drain function drained it, we
775 * remember if the last byte was a \n with the SBUF_DRAINATEOL flag in
778 * In either case, we only append a \n if the previous character was
782 if (!SBUF_ISDRAINATEOL(s))
783 sbuf_put_byte(s, '\n');
784 } else if (s->s_buf[s->s_len - 1] != '\n')
785 sbuf_put_byte(s, '\n');
793 * Trim whitespace characters from end of an sbuf.
796 sbuf_trim(struct sbuf *s)
799 assert_sbuf_integrity(s);
800 assert_sbuf_state(s, 0);
801 KASSERT(s->s_drain_func == NULL,
802 ("%s makes no sense on sbuf %p with drain", __func__, s));
807 while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1])) {
809 if (SBUF_ISSECTION(s))
817 * Check if an sbuf has an error.
820 sbuf_error(const struct sbuf *s)
827 * Finish off an sbuf.
830 sbuf_finish(struct sbuf *s)
833 assert_sbuf_integrity(s);
834 assert_sbuf_state(s, 0);
836 s->s_buf[s->s_len] = '\0';
837 if (SBUF_NULINCLUDED(s))
839 if (s->s_drain_func != NULL) {
840 while (s->s_len > 0 && s->s_error == 0)
841 s->s_error = sbuf_drain(s);
843 SBUF_SETFLAG(s, SBUF_FINISHED);
847 if (s->s_error != 0) {
856 * Return a pointer to the sbuf data.
859 sbuf_data(struct sbuf *s)
862 assert_sbuf_integrity(s);
863 assert_sbuf_state(s, SBUF_FINISHED);
864 KASSERT(s->s_drain_func == NULL,
865 ("%s makes no sense on sbuf %p with drain", __func__, s));
871 * Return the length of the sbuf data.
874 sbuf_len(struct sbuf *s)
877 assert_sbuf_integrity(s);
878 /* don't care if it's finished or not */
879 KASSERT(s->s_drain_func == NULL,
880 ("%s makes no sense on sbuf %p with drain", __func__, s));
885 /* If finished, nulterm is already in len, else add one. */
886 if (SBUF_NULINCLUDED(s) && !SBUF_ISFINISHED(s))
887 return (s->s_len + 1);
892 * Clear an sbuf, free its buffer if necessary.
895 sbuf_delete(struct sbuf *s)
899 assert_sbuf_integrity(s);
900 /* don't care if it's finished or not */
902 if (SBUF_ISDYNAMIC(s))
904 isdyn = SBUF_ISDYNSTRUCT(s);
905 memset(s, 0, sizeof(*s));
911 * Check if an sbuf has been finished.
914 sbuf_done(const struct sbuf *s)
917 return (SBUF_ISFINISHED(s));
924 sbuf_start_section(struct sbuf *s, ssize_t *old_lenp)
927 assert_sbuf_integrity(s);
928 assert_sbuf_state(s, 0);
930 if (!SBUF_ISSECTION(s)) {
931 KASSERT(s->s_sect_len == 0,
932 ("s_sect_len != 0 when starting a section"));
933 if (old_lenp != NULL)
935 s->s_rec_off = s->s_len;
936 SBUF_SETFLAG(s, SBUF_INSECTION);
938 KASSERT(old_lenp != NULL,
939 ("s_sect_len should be saved when starting a subsection"));
940 *old_lenp = s->s_sect_len;
946 * End the section padding to the specified length with the specified
950 sbuf_end_section(struct sbuf *s, ssize_t old_len, size_t pad, int c)
954 assert_sbuf_integrity(s);
955 assert_sbuf_state(s, 0);
956 KASSERT(SBUF_ISSECTION(s),
957 ("attempt to end a section when not in a section"));
960 len = roundup(s->s_sect_len, pad) - s->s_sect_len;
961 for (; s->s_error == 0 && len > 0; len--)
966 s->s_rec_off = s->s_sect_len = 0;
967 SBUF_CLEARFLAG(s, SBUF_INSECTION);
969 s->s_sect_len += old_len;