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)
56 #define SBFREE(buf) free(buf, M_SBUF)
59 #define SBMALLOC(size) malloc(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)
76 #define SBUF_SETFLAG(s, f) do { (s)->s_flags |= (f); } while (0)
77 #define SBUF_CLEARFLAG(s, f) do { (s)->s_flags &= ~(f); } while (0)
79 #define SBUF_MINEXTENDSIZE 16 /* Should be power of 2. */
82 #define SBUF_MAXEXTENDSIZE PAGE_SIZE
83 #define SBUF_MAXEXTENDINCR PAGE_SIZE
85 #define SBUF_MAXEXTENDSIZE 4096
86 #define SBUF_MAXEXTENDINCR 4096
92 #if defined(_KERNEL) && defined(INVARIANTS)
95 _assert_sbuf_integrity(const char *fun, struct sbuf *s)
99 ("%s called with a NULL sbuf pointer", fun));
100 KASSERT(s->s_buf != NULL,
101 ("%s called with uninitialized or corrupt sbuf", fun));
102 KASSERT(s->s_len < s->s_size,
103 ("wrote past end of sbuf (%jd >= %jd)",
104 (intmax_t)s->s_len, (intmax_t)s->s_size));
108 _assert_sbuf_state(const char *fun, struct sbuf *s, int state)
111 KASSERT((s->s_flags & SBUF_FINISHED) == state,
112 ("%s called with %sfinished or corrupt sbuf", fun,
113 (state ? "un" : "")));
116 #define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s))
117 #define assert_sbuf_state(s, i) _assert_sbuf_state(__func__, (s), (i))
119 #else /* _KERNEL && INVARIANTS */
121 #define assert_sbuf_integrity(s) do { } while (0)
122 #define assert_sbuf_state(s, i) do { } while (0)
124 #endif /* _KERNEL && INVARIANTS */
127 CTASSERT(powerof2(SBUF_MAXEXTENDSIZE));
128 CTASSERT(powerof2(SBUF_MAXEXTENDINCR));
132 sbuf_extendsize(int size)
136 if (size < (int)SBUF_MAXEXTENDSIZE) {
137 newsize = SBUF_MINEXTENDSIZE;
138 while (newsize < size)
141 newsize = roundup2(size, SBUF_MAXEXTENDINCR);
143 KASSERT(newsize >= size, ("%s: %d < %d\n", __func__, newsize, size));
151 sbuf_extend(struct sbuf *s, int addlen)
156 if (!SBUF_CANEXTEND(s))
158 newsize = sbuf_extendsize(s->s_size + addlen);
159 newbuf = SBMALLOC(newsize);
162 memcpy(newbuf, s->s_buf, s->s_size);
163 if (SBUF_ISDYNAMIC(s))
166 SBUF_SETFLAG(s, SBUF_DYNAMIC);
173 * Initialize the internals of an sbuf.
174 * If buf is non-NULL, it points to a static or already-allocated string
175 * big enough to hold at least length characters.
178 sbuf_newbuf(struct sbuf *s, char *buf, int length, int flags)
181 memset(s, 0, sizeof(*s));
186 if ((s->s_flags & SBUF_AUTOEXTEND) == 0) {
187 KASSERT(s->s_size >= 0,
188 ("attempt to create a too small sbuf"));
191 if (s->s_buf != NULL)
194 if ((flags & SBUF_AUTOEXTEND) != 0)
195 s->s_size = sbuf_extendsize(s->s_size);
197 s->s_buf = SBMALLOC(s->s_size);
198 if (s->s_buf == NULL)
200 SBUF_SETFLAG(s, SBUF_DYNAMIC);
205 * Initialize an sbuf.
206 * If buf is non-NULL, it points to a static or already-allocated string
207 * big enough to hold at least length characters.
210 sbuf_new(struct sbuf *s, char *buf, int length, int flags)
214 ("attempt to create an sbuf of negative length (%d)", length));
215 KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
216 ("%s called with invalid flags", __func__));
218 flags &= SBUF_USRFLAGMSK;
220 return (sbuf_newbuf(s, buf, length, flags));
222 s = SBMALLOC(sizeof(*s));
225 if (sbuf_newbuf(s, buf, length, flags) == NULL) {
229 SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
235 * Create an sbuf with uio data
238 sbuf_uionew(struct sbuf *s, struct uio *uio, int *error)
242 ("%s called with NULL uio pointer", __func__));
243 KASSERT(error != NULL,
244 ("%s called with NULL error pointer", __func__));
246 s = sbuf_new(s, NULL, uio->uio_resid + 1, 0);
251 *error = uiomove(s->s_buf, uio->uio_resid, uio);
256 s->s_len = s->s_size - 1;
263 * Clear an sbuf and reset its position.
266 sbuf_clear(struct sbuf *s)
269 assert_sbuf_integrity(s);
270 /* don't care if it's finished or not */
272 SBUF_CLEARFLAG(s, SBUF_FINISHED);
278 * Set the sbuf's end position to an arbitrary value.
279 * Effectively truncates the sbuf at the new position.
282 sbuf_setpos(struct sbuf *s, ssize_t pos)
285 assert_sbuf_integrity(s);
286 assert_sbuf_state(s, 0);
289 ("attempt to seek to a negative position (%jd)", (intmax_t)pos));
290 KASSERT(pos < s->s_size,
291 ("attempt to seek past end of sbuf (%jd >= %jd)",
292 (intmax_t)pos, (intmax_t)s->s_size));
294 if (pos < 0 || pos > s->s_len)
301 * Set up a drain function and argument on an sbuf to flush data to
302 * when the sbuf buffer overflows.
305 sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx)
308 assert_sbuf_state(s, 0);
309 assert_sbuf_integrity(s);
310 KASSERT(func == s->s_drain_func || s->s_len == 0,
311 ("Cannot change drain to %p on non-empty sbuf %p", func, s));
312 s->s_drain_func = func;
313 s->s_drain_arg = ctx;
317 * Call the drain and process the return.
320 sbuf_drain(struct sbuf *s)
324 KASSERT(s->s_len > 0, ("Shouldn't drain empty sbuf %p", s));
325 KASSERT(s->s_error == 0, ("Called %s with error on %p", __func__, s));
326 len = s->s_drain_func(s->s_drain_arg, s->s_buf, s->s_len);
331 KASSERT(len > 0 && len <= s->s_len,
332 ("Bad drain amount %d for sbuf %p", len, s));
335 * Fast path for the expected case where all the data was
341 * Move the remaining characters to the beginning of the
344 memmove(s->s_buf, s->s_buf + len, s->s_len);
349 * Append a byte to an sbuf. This is the core function for appending
350 * to an sbuf and is the main place that deals with extending the
351 * buffer and marking overflow.
354 sbuf_put_byte(struct sbuf *s, int c)
357 assert_sbuf_integrity(s);
358 assert_sbuf_state(s, 0);
362 if (SBUF_FREESPACE(s) <= 0) {
364 * If there is a drain, use it, otherwise extend the
367 if (s->s_drain_func != NULL)
369 else if (sbuf_extend(s, 1) < 0)
374 s->s_buf[s->s_len++] = c;
378 * Append a byte string to an sbuf.
381 sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
383 const char *str = buf;
384 const char *end = str + len;
386 assert_sbuf_integrity(s);
387 assert_sbuf_state(s, 0);
391 for (; str < end; str++) {
392 sbuf_put_byte(s, *str);
401 * Copy a byte string from userland into an sbuf.
404 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
407 assert_sbuf_integrity(s);
408 assert_sbuf_state(s, 0);
409 KASSERT(s->s_drain_func == NULL,
410 ("Nonsensical copyin to sbuf %p with a drain", s));
416 if (len > SBUF_FREESPACE(s)) {
417 sbuf_extend(s, len - SBUF_FREESPACE(s));
418 if (SBUF_FREESPACE(s) < len)
419 len = SBUF_FREESPACE(s);
421 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
430 * Copy a byte string into an sbuf.
433 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len)
436 assert_sbuf_integrity(s);
437 assert_sbuf_state(s, 0);
440 return (sbuf_bcat(s, buf, len));
444 * Append a string to an sbuf.
447 sbuf_cat(struct sbuf *s, const char *str)
450 assert_sbuf_integrity(s);
451 assert_sbuf_state(s, 0);
456 while (*str != '\0') {
457 sbuf_put_byte(s, *str++);
466 * Append a string from userland to an sbuf.
469 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
473 assert_sbuf_integrity(s);
474 assert_sbuf_state(s, 0);
475 KASSERT(s->s_drain_func == NULL,
476 ("Nonsensical copyin to sbuf %p with a drain", s));
482 len = SBUF_FREESPACE(s); /* XXX return 0? */
483 if (len > SBUF_FREESPACE(s)) {
485 if (SBUF_FREESPACE(s) < len)
486 len = SBUF_FREESPACE(s);
488 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
493 s->s_len += done - 1;
496 return (-1); /* XXX */
504 * Copy a string into an sbuf.
507 sbuf_cpy(struct sbuf *s, const char *str)
510 assert_sbuf_integrity(s);
511 assert_sbuf_state(s, 0);
514 return (sbuf_cat(s, str));
518 * Format the given argument list and append the resulting string to an sbuf.
523 * Append a non-NUL character to an sbuf. This prototype signature is
524 * suitable for use with kvprintf(9).
527 sbuf_putc_func(int c, void *arg)
531 sbuf_put_byte(arg, c);
535 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
538 assert_sbuf_integrity(s);
539 assert_sbuf_state(s, 0);
542 ("%s called with a NULL format string", __func__));
544 (void)kvprintf(fmt, sbuf_putc_func, s, 10, ap);
551 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
556 assert_sbuf_integrity(s);
557 assert_sbuf_state(s, 0);
560 ("%s called with a NULL format string", __func__));
566 * For the moment, there is no way to get vsnprintf(3) to hand
567 * back a character at a time, to push everything into
568 * sbuf_putc_func() as was done for the kernel.
570 * In userspace, while drains are useful, there's generally
571 * not a problem attempting to malloc(3) on out of space. So
572 * expand a userland sbuf if there is not enough room for the
573 * data produced by sbuf_[v]printf(3).
578 va_copy(ap_copy, ap);
579 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
583 if (SBUF_FREESPACE(s) >= len)
585 /* Cannot print with the current available space. */
586 if (s->s_drain_func != NULL && s->s_len > 0)
587 error = sbuf_drain(s);
589 error = sbuf_extend(s, len - SBUF_FREESPACE(s));
590 } while (error == 0);
593 * s->s_len is the length of the string, without the terminating nul.
594 * When updating s->s_len, we must subtract 1 from the length that
595 * we passed into vsnprintf() because that length includes the
598 * vsnprintf() returns the amount that would have been copied,
599 * given sufficient space, so don't over-increment s_len.
601 if (SBUF_FREESPACE(s) < len)
602 len = SBUF_FREESPACE(s);
604 if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
607 KASSERT(s->s_len < s->s_size,
608 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
617 * Format the given arguments and append the resulting string to an sbuf.
620 sbuf_printf(struct sbuf *s, const char *fmt, ...)
626 result = sbuf_vprintf(s, fmt, ap);
632 * Append a character to an sbuf.
635 sbuf_putc(struct sbuf *s, int c)
645 * Trim whitespace characters from end of an sbuf.
648 sbuf_trim(struct sbuf *s)
651 assert_sbuf_integrity(s);
652 assert_sbuf_state(s, 0);
653 KASSERT(s->s_drain_func == NULL,
654 ("%s makes no sense on sbuf %p with drain", __func__, s));
659 while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1]))
666 * Check if an sbuf has an error.
669 sbuf_error(const struct sbuf *s)
676 * Finish off an sbuf.
679 sbuf_finish(struct sbuf *s)
682 assert_sbuf_integrity(s);
683 assert_sbuf_state(s, 0);
685 if (s->s_drain_func != NULL) {
686 while (s->s_len > 0 && s->s_error == 0)
687 s->s_error = sbuf_drain(s);
689 s->s_buf[s->s_len] = '\0';
690 SBUF_SETFLAG(s, SBUF_FINISHED);
702 * Return a pointer to the sbuf data.
705 sbuf_data(struct sbuf *s)
708 assert_sbuf_integrity(s);
709 assert_sbuf_state(s, SBUF_FINISHED);
710 KASSERT(s->s_drain_func == NULL,
711 ("%s makes no sense on sbuf %p with drain", __func__, s));
717 * Return the length of the sbuf data.
720 sbuf_len(struct sbuf *s)
723 assert_sbuf_integrity(s);
724 /* don't care if it's finished or not */
725 KASSERT(s->s_drain_func == NULL,
726 ("%s makes no sense on sbuf %p with drain", __func__, s));
734 * Clear an sbuf, free its buffer if necessary.
737 sbuf_delete(struct sbuf *s)
741 assert_sbuf_integrity(s);
742 /* don't care if it's finished or not */
744 if (SBUF_ISDYNAMIC(s))
746 isdyn = SBUF_ISDYNSTRUCT(s);
747 memset(s, 0, sizeof(*s));
753 * Check if an sbuf has been finished.
756 sbuf_done(const struct sbuf *s)
759 return (SBUF_ISFINISHED(s));