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 sbuf_drain_func *s_func; /* drain function */
55 void *s_arg; /* user-supplied drain argument */
56 int s_error; /* current error code */
60 static MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers");
61 #define SBMALLOC(size) malloc(size, M_SBUF, M_WAITOK)
62 #define SBFREE(buf) free(buf, M_SBUF)
65 #define SBMALLOC(size) malloc(size)
66 #define SBFREE(buf) free(buf)
72 #define SBUF_ISDYNAMIC(s) ((s)->s_flags & SBUF_DYNAMIC)
73 #define SBUF_ISDYNSTRUCT(s) ((s)->s_flags & SBUF_DYNSTRUCT)
74 #define SBUF_ISFINISHED(s) ((s)->s_flags & SBUF_FINISHED)
75 #define SBUF_HASOVERFLOWED(s) ((s)->s_flags & SBUF_OVERFLOWED)
76 #define SBUF_HASROOM(s) ((s)->s_len < (s)->s_size - 1)
77 #define SBUF_FREESPACE(s) ((s)->s_size - (s)->s_len - 1)
78 #define SBUF_CANEXTEND(s) ((s)->s_flags & SBUF_AUTOEXTEND)
83 #define SBUF_SETFLAG(s, f) do { (s)->s_flags |= (f); } while (0)
84 #define SBUF_CLEARFLAG(s, f) do { (s)->s_flags &= ~(f); } while (0)
86 #define SBUF_MINEXTENDSIZE 16 /* Should be power of 2. */
87 #define SBUF_MAXEXTENDSIZE PAGE_SIZE
88 #define SBUF_MAXEXTENDINCR PAGE_SIZE
93 #if defined(_KERNEL) && defined(INVARIANTS)
96 _assert_sbuf_integrity(const char *fun, struct sbuf *s)
100 ("%s called with a NULL sbuf pointer", fun));
101 KASSERT(s->s_buf != NULL,
102 ("%s called with uninitialized or corrupt sbuf", fun));
103 KASSERT(s->s_len < s->s_size,
104 ("wrote past end of sbuf (%d >= %d)", s->s_len, 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));
152 sbuf_extend(struct sbuf *s, int addlen)
157 if (!SBUF_CANEXTEND(s))
159 newsize = sbuf_extendsize(s->s_size + addlen);
160 newbuf = SBMALLOC(newsize);
163 bcopy(s->s_buf, newbuf, s->s_size);
164 if (SBUF_ISDYNAMIC(s))
167 SBUF_SETFLAG(s, SBUF_DYNAMIC);
174 * Initialize an sbuf.
175 * If buf is non-NULL, it points to a static or already-allocated string
176 * big enough to hold at least length characters.
179 sbuf_new(struct sbuf *s, char *buf, int length, int flags)
183 ("attempt to create an sbuf of negative length (%d)", length));
184 KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
185 ("%s called with invalid flags", __func__));
187 flags &= SBUF_USRFLAGMSK;
189 s = SBMALLOC(sizeof(*s));
192 bzero(s, sizeof(*s));
194 SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
196 bzero(s, sizeof(*s));
204 if ((flags & SBUF_AUTOEXTEND) != 0)
205 s->s_size = sbuf_extendsize(s->s_size);
206 s->s_buf = SBMALLOC(s->s_size);
207 if (s->s_buf == NULL) {
208 if (SBUF_ISDYNSTRUCT(s))
212 SBUF_SETFLAG(s, SBUF_DYNAMIC);
218 * Create an sbuf with uio data
221 sbuf_uionew(struct sbuf *s, struct uio *uio, int *error)
225 ("%s called with NULL uio pointer", __func__));
226 KASSERT(error != NULL,
227 ("%s called with NULL error pointer", __func__));
229 s = sbuf_new(s, NULL, uio->uio_resid + 1, 0);
234 *error = uiomove(s->s_buf, uio->uio_resid, uio);
239 s->s_len = s->s_size - 1;
246 * Clear an sbuf and reset its position.
249 sbuf_clear(struct sbuf *s)
252 assert_sbuf_integrity(s);
253 /* don't care if it's finished or not */
255 SBUF_CLEARFLAG(s, SBUF_FINISHED);
256 SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
257 if (s->s_drain != NULL)
258 s->s_drain->s_error = 0;
263 * Set the sbuf's end position to an arbitrary value.
264 * Effectively truncates the sbuf at the new position.
267 sbuf_setpos(struct sbuf *s, int pos)
270 assert_sbuf_integrity(s);
271 assert_sbuf_state(s, 0);
274 ("attempt to seek to a negative position (%d)", pos));
275 KASSERT(pos < s->s_size,
276 ("attempt to seek past end of sbuf (%d >= %d)", pos, s->s_size));
278 if (pos < 0 || pos > s->s_len)
285 * Set up a drain function and argument on an sbuf to flush data to
286 * when the sbuf buffer overflows.
289 sbuf_set_drain(struct sbuf *s, sbuf_drain_func *func, void *ctx)
292 assert_sbuf_state(s, 0);
293 assert_sbuf_integrity(s);
294 KASSERT((s->s_drain != NULL && func == s->s_drain->s_func) ||
296 ("Cannot change drain to %p on non-empty sbuf %p", func, s));
302 if (s->s_drain == NULL) {
303 s->s_drain = SBMALLOC(sizeof(*s->s_drain));
304 if (s->s_drain == NULL)
307 s->s_drain->s_func = func;
308 s->s_drain->s_arg = ctx;
309 s->s_drain->s_error = 0;
313 * Call the drain and process the return.
316 sbuf_drain(struct sbuf *s)
320 KASSERT(s->s_len > 0, ("Shouldn't drain empty sbuf %p", s));
321 len = s->s_drain->s_func(s->s_drain->s_arg, s->s_buf, s->s_len);
323 s->s_drain->s_error = -len;
324 SBUF_SETFLAG(s, SBUF_OVERFLOWED);
325 return (s->s_drain->s_error);
327 KASSERT(len > 0 && len <= s->s_len,
328 ("Bad drain amount %d for sbuf %p", len, s));
331 * Fast path for the expected case where all the data was
337 * Move the remaining characters to the beginning of the
340 memmove(s->s_buf, s->s_buf + len, s->s_len);
345 * Append a byte to an sbuf. This is the core function for appending
346 * to an sbuf and is the main place that deals with extending the
347 * buffer and marking overflow.
350 sbuf_put_byte(int c, struct sbuf *s)
353 assert_sbuf_integrity(s);
354 assert_sbuf_state(s, 0);
356 if (SBUF_HASOVERFLOWED(s))
358 if (SBUF_FREESPACE(s) <= 0) {
360 * If there is a drain, use it, otherwise extend the
363 if (s->s_drain != NULL)
365 else if (sbuf_extend(s, 1) < 0)
366 SBUF_SETFLAG(s, SBUF_OVERFLOWED);
367 if (SBUF_HASOVERFLOWED(s))
370 s->s_buf[s->s_len++] = c;
374 * Append a non-NUL character to an sbuf. This prototype signature is
375 * suitable for use with kvprintf(9).
378 sbuf_putc_func(int c, void *arg)
382 sbuf_put_byte(c, arg);
386 * Append a byte string to an sbuf.
389 sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
391 const char *str = buf;
392 const char *end = str + len;
394 assert_sbuf_integrity(s);
395 assert_sbuf_state(s, 0);
397 if (SBUF_HASOVERFLOWED(s))
399 for (; str < end; str++) {
400 sbuf_put_byte(*str, s);
401 if (SBUF_HASOVERFLOWED(s))
409 * Copy a byte string from userland into an sbuf.
412 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
415 assert_sbuf_integrity(s);
416 assert_sbuf_state(s, 0);
417 KASSERT(s->s_drain == NULL,
418 ("Nonsensical copyin to sbuf %p with a drain", s));
420 if (SBUF_HASOVERFLOWED(s))
424 if (len > SBUF_FREESPACE(s)) {
425 sbuf_extend(s, len - SBUF_FREESPACE(s));
426 if (SBUF_FREESPACE(s) < len)
427 len = SBUF_FREESPACE(s);
429 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
438 * Copy a byte string into an sbuf.
441 sbuf_bcpy(struct sbuf *s, const void *buf, size_t len)
444 assert_sbuf_integrity(s);
445 assert_sbuf_state(s, 0);
448 return (sbuf_bcat(s, buf, len));
452 * Append a string to an sbuf.
455 sbuf_cat(struct sbuf *s, const char *str)
458 assert_sbuf_integrity(s);
459 assert_sbuf_state(s, 0);
461 if (SBUF_HASOVERFLOWED(s))
464 while (*str != '\0') {
465 sbuf_put_byte(*str++, s);
466 if (SBUF_HASOVERFLOWED(s))
474 * Append a string from userland to an sbuf.
477 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
481 assert_sbuf_integrity(s);
482 assert_sbuf_state(s, 0);
483 KASSERT(s->s_drain == NULL,
484 ("Nonsensical copyin to sbuf %p with a drain", s));
486 if (SBUF_HASOVERFLOWED(s))
490 len = SBUF_FREESPACE(s); /* XXX return 0? */
491 if (len > SBUF_FREESPACE(s)) {
493 if (SBUF_FREESPACE(s) < len)
494 len = SBUF_FREESPACE(s);
496 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
498 SBUF_SETFLAG(s, SBUF_OVERFLOWED);
501 s->s_len += done - 1;
504 return (-1); /* XXX */
512 * Copy a string into an sbuf.
515 sbuf_cpy(struct sbuf *s, const char *str)
518 assert_sbuf_integrity(s);
519 assert_sbuf_state(s, 0);
522 return (sbuf_cat(s, str));
526 * Format the given argument list and append the resulting string to an sbuf.
530 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
533 assert_sbuf_integrity(s);
534 assert_sbuf_state(s, 0);
537 ("%s called with a NULL format string", __func__));
539 (void)kvprintf(fmt, sbuf_putc_func, s, 10, ap);
540 if (SBUF_HASOVERFLOWED(s))
546 sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
551 assert_sbuf_integrity(s);
552 assert_sbuf_state(s, 0);
555 ("%s called with a NULL format string", __func__));
557 if (SBUF_HASOVERFLOWED(s))
561 * For the moment, there is no way to get vsnprintf(3) to hand
562 * back a character at a time, to push everything into
563 * sbuf_putc_func() as was done for the kernel.
565 * In userspace, while drains are useful, there's generally
566 * not a problem attempting to malloc(3) on out of space. So
567 * expand a userland sbuf if there is not enough room for the
568 * data produced by sbuf_[v]printf(3).
573 va_copy(ap_copy, ap);
574 len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
578 if (SBUF_FREESPACE(s) >= len)
580 /* Cannot print with the current available space. */
581 if (s->s_drain != NULL && s->s_len > 0)
582 error = sbuf_drain(s);
584 error = sbuf_extend(s, len - SBUF_FREESPACE(s));
585 } while (error == 0);
588 * s->s_len is the length of the string, without the terminating nul.
589 * When updating s->s_len, we must subtract 1 from the length that
590 * we passed into vsnprintf() because that length includes the
593 * vsnprintf() returns the amount that would have been copied,
594 * given sufficient space, so don't over-increment s_len.
596 if (SBUF_FREESPACE(s) < len)
597 len = SBUF_FREESPACE(s);
599 if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
600 SBUF_SETFLAG(s, SBUF_OVERFLOWED);
602 KASSERT(s->s_len < s->s_size,
603 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
605 if (SBUF_HASOVERFLOWED(s))
612 * Format the given arguments and append the resulting string to an sbuf.
615 sbuf_printf(struct sbuf *s, const char *fmt, ...)
621 result = sbuf_vprintf(s, fmt, ap);
627 * Append a character to an sbuf.
630 sbuf_putc(struct sbuf *s, int c)
633 sbuf_putc_func(c, s);
634 if (SBUF_HASOVERFLOWED(s))
640 * Trim whitespace characters from end of an sbuf.
643 sbuf_trim(struct sbuf *s)
646 assert_sbuf_integrity(s);
647 assert_sbuf_state(s, 0);
648 KASSERT(s->s_drain == NULL,
649 ("%s makes no sense on sbuf %p with drain", __func__, s));
651 if (SBUF_HASOVERFLOWED(s))
654 while (s->s_len > 0 && isspace(s->s_buf[s->s_len-1]))
661 * Check if an sbuf overflowed
664 sbuf_overflowed(struct sbuf *s)
667 return (SBUF_HASOVERFLOWED(s));
671 * Finish off an sbuf.
674 sbuf_finish(struct sbuf *s)
678 assert_sbuf_integrity(s);
679 assert_sbuf_state(s, 0);
681 if (s->s_drain != NULL) {
682 error = s->s_drain->s_error;
683 while (s->s_len > 0 && error == 0)
684 error = sbuf_drain(s);
685 } else if (SBUF_HASOVERFLOWED(s))
687 s->s_buf[s->s_len] = '\0';
688 SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
689 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 == 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 == NULL,
726 ("%s makes no sense on sbuf %p with drain", __func__, s));
728 if (SBUF_HASOVERFLOWED(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 if (s->s_drain != NULL)
748 isdyn = SBUF_ISDYNSTRUCT(s);
749 bzero(s, sizeof(*s));
755 * Check if an sbuf has been finished.
758 sbuf_done(struct sbuf *s)
761 return (SBUF_ISFINISHED(s));