2 * Copyright (c) 2000 Poul-Henning Kamp and Dag-Erling Coïdan Smørgrav
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 * $FreeBSD: src/sys/kern/subr_sbuf.c,v 1.11.2.2 2002/03/12 01:01:07 archie Exp $
29 * $DragonFly: src/sys/kern/subr_sbuf.c,v 1.9 2006/12/22 08:08:25 swildner Exp $
32 #include <sys/param.h>
35 #include <sys/ctype.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/systm.h>
40 #include <machine/stdarg.h>
52 MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers");
53 #define SBMALLOC(size) kmalloc(size, M_SBUF, M_WAITOK)
54 #define SBFREE(buf) kfree(buf, M_SBUF)
57 #define SBMALLOC(size) malloc(size)
58 #define SBFREE(buf) free(buf)
59 #define kvsnprintf vsnprintf
65 #define SBUF_ISDYNAMIC(s) ((s)->s_flags & SBUF_DYNAMIC)
66 #define SBUF_ISDYNSTRUCT(s) ((s)->s_flags & SBUF_DYNSTRUCT)
67 #define SBUF_ISFINISHED(s) ((s)->s_flags & SBUF_FINISHED)
68 #define SBUF_HASOVERFLOWED(s) ((s)->s_flags & SBUF_OVERFLOWED)
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. */
80 #define SBUF_MAXEXTENDSIZE PAGE_SIZE
81 #define SBUF_MAXEXTENDINCR PAGE_SIZE
86 #if defined(_KERNEL) && defined(INVARIANTS)
88 _assert_sbuf_integrity(const char *fun, struct sbuf *s)
91 ("%s called with a NULL sbuf pointer", fun));
92 KASSERT(s->s_buf != NULL,
93 ("%s called with uninitialized or corrupt sbuf", fun));
94 KASSERT(s->s_len < s->s_size,
95 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
99 _assert_sbuf_state(const char *fun, struct sbuf *s, int state)
101 KASSERT((s->s_flags & SBUF_FINISHED) == state,
102 ("%s called with %sfinished or corrupt sbuf", fun,
103 (state ? "un" : "")));
105 #define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s))
106 #define assert_sbuf_state(s, i) _assert_sbuf_state(__func__, (s), (i))
107 #else /* _KERNEL && INVARIANTS */
108 #define assert_sbuf_integrity(s) do { } while (0)
109 #define assert_sbuf_state(s, i) do { } while (0)
110 #endif /* _KERNEL && INVARIANTS */
113 sbuf_extendsize(int size)
117 newsize = SBUF_MINEXTENDSIZE;
118 while (newsize < size) {
119 if (newsize < SBUF_MAXEXTENDSIZE)
122 newsize += SBUF_MAXEXTENDINCR;
133 sbuf_extend(struct sbuf *s, int addlen)
138 if (!SBUF_CANEXTEND(s))
141 newsize = sbuf_extendsize(s->s_size + addlen);
142 newbuf = (char *)SBMALLOC(newsize);
145 bcopy(s->s_buf, newbuf, s->s_size);
146 if (SBUF_ISDYNAMIC(s))
149 SBUF_SETFLAG(s, SBUF_DYNAMIC);
156 * Initialize an sbuf.
157 * If buf is non-NULL, it points to a static or already-allocated string
158 * big enough to hold at least length characters.
161 sbuf_new(struct sbuf *s, char *buf, int length, int flags)
164 ("attempt to create an sbuf of negative length (%d)", length));
165 KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
166 ("%s called with invalid flags", __func__));
168 flags &= SBUF_USRFLAGMSK;
170 s = (struct sbuf *)SBMALLOC(sizeof *s);
175 SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
185 if (flags & SBUF_AUTOEXTEND)
186 s->s_size = sbuf_extendsize(s->s_size);
187 s->s_buf = (char *)SBMALLOC(s->s_size);
188 if (s->s_buf == NULL) {
189 if (SBUF_ISDYNSTRUCT(s))
193 SBUF_SETFLAG(s, SBUF_DYNAMIC);
199 * Create an sbuf with uio data
202 sbuf_uionew(struct sbuf *s, struct uio *uio, int *error)
205 ("%s called with NULL uio pointer", __func__));
206 KASSERT(error != NULL,
207 ("%s called with NULL error pointer", __func__));
209 s = sbuf_new(s, NULL, uio->uio_resid + 1, 0);
214 *error = uiomove(s->s_buf, uio->uio_resid, uio);
219 s->s_len = s->s_size - 1;
226 * Clear an sbuf and reset its position.
229 sbuf_clear(struct sbuf *s)
231 assert_sbuf_integrity(s);
232 /* don't care if it's finished or not */
234 SBUF_CLEARFLAG(s, SBUF_FINISHED);
235 SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
240 * Set the sbuf's end position to an arbitrary value.
241 * Effectively truncates the sbuf at the new position.
244 sbuf_setpos(struct sbuf *s, int pos)
246 assert_sbuf_integrity(s);
247 assert_sbuf_state(s, 0);
250 ("attempt to seek to a negative position (%d)", pos));
251 KASSERT(pos < s->s_size,
252 ("attempt to seek past end of sbuf (%d >= %d)", pos, s->s_size));
254 if (pos < 0 || pos > s->s_len)
261 * Append a byte string to an sbuf.
264 sbuf_bcat(struct sbuf *s, const char *str, size_t len)
266 assert_sbuf_integrity(s);
267 assert_sbuf_state(s, 0);
269 if (SBUF_HASOVERFLOWED(s))
273 if (!SBUF_HASROOM(s) && sbuf_extend(s, len) < 0)
275 s->s_buf[s->s_len++] = *str++;
278 SBUF_SETFLAG(s, SBUF_OVERFLOWED);
286 * Copy a byte string from userland into an sbuf.
289 sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
291 assert_sbuf_integrity(s);
292 assert_sbuf_state(s, 0);
294 if (SBUF_HASOVERFLOWED(s))
299 if (len > SBUF_FREESPACE(s)) {
300 sbuf_extend(s, len - SBUF_FREESPACE(s));
301 len = MIN(len, SBUF_FREESPACE(s));
303 if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
312 * Copy a byte string into an sbuf.
315 sbuf_bcpy(struct sbuf *s, const char *str, size_t len)
317 assert_sbuf_integrity(s);
318 assert_sbuf_state(s, 0);
321 return (sbuf_bcat(s, str, len));
325 * Append a string to an sbuf.
328 sbuf_cat(struct sbuf *s, const char *str)
330 assert_sbuf_integrity(s);
331 assert_sbuf_state(s, 0);
333 if (SBUF_HASOVERFLOWED(s))
337 if (!SBUF_HASROOM(s) && sbuf_extend(s, strlen(str)) < 0)
339 s->s_buf[s->s_len++] = *str++;
342 SBUF_SETFLAG(s, SBUF_OVERFLOWED);
350 * Append a string from userland to an sbuf.
353 sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
357 assert_sbuf_integrity(s);
358 assert_sbuf_state(s, 0);
360 if (SBUF_HASOVERFLOWED(s))
364 len = SBUF_FREESPACE(s); /* XXX return 0? */
365 if (len > SBUF_FREESPACE(s)) {
367 len = MIN(len, SBUF_FREESPACE(s));
369 switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
371 SBUF_SETFLAG(s, SBUF_OVERFLOWED);
374 s->s_len += done - 1;
377 return (-1); /* XXX */
385 * Copy a string into an sbuf.
388 sbuf_cpy(struct sbuf *s, const char *str)
390 assert_sbuf_integrity(s);
391 assert_sbuf_state(s, 0);
394 return (sbuf_cat(s, str));
398 * Format the given argument list and append the resulting string to an sbuf.
401 sbuf_vprintf(struct sbuf *s, const char *fmt, __va_list ap)
405 assert_sbuf_integrity(s);
406 assert_sbuf_state(s, 0);
409 ("%s called with a NULL format string", __func__));
411 if (SBUF_HASOVERFLOWED(s))
415 len = kvsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
417 } while (len > SBUF_FREESPACE(s) &&
418 sbuf_extend(s, len - SBUF_FREESPACE(s)) == 0);
421 * s->s_len is the length of the string, without the terminating nul.
422 * When updating s->s_len, we must subtract 1 from the length that
423 * we passed into kvsnprintf() because that length includes the
426 * kvsnprintf() returns the amount that would have been copied,
427 * given sufficient space, hence the min() calculation below.
429 s->s_len += MIN(len, SBUF_FREESPACE(s));
430 if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
431 SBUF_SETFLAG(s, SBUF_OVERFLOWED);
433 KASSERT(s->s_len < s->s_size,
434 ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
436 if (SBUF_HASOVERFLOWED(s))
442 * Format the given arguments and append the resulting string to an sbuf.
445 sbuf_printf(struct sbuf *s, const char *fmt, ...)
451 result = sbuf_vprintf(s, fmt, ap);
457 * Append a character to an sbuf.
460 sbuf_putc(struct sbuf *s, int c)
462 assert_sbuf_integrity(s);
463 assert_sbuf_state(s, 0);
465 if (SBUF_HASOVERFLOWED(s))
468 if (!SBUF_HASROOM(s) && sbuf_extend(s, 1) < 0) {
469 SBUF_SETFLAG(s, SBUF_OVERFLOWED);
473 s->s_buf[s->s_len++] = c;
478 * Trim whitespace characters from end of an sbuf.
481 sbuf_trim(struct sbuf *s)
483 assert_sbuf_integrity(s);
484 assert_sbuf_state(s, 0);
486 if (SBUF_HASOVERFLOWED(s))
489 while (s->s_len && isspace(s->s_buf[s->s_len-1]))
496 * Check if an sbuf overflowed
499 sbuf_overflowed(struct sbuf *s)
501 return SBUF_HASOVERFLOWED(s);
505 * Finish off an sbuf.
508 sbuf_finish(struct sbuf *s)
510 assert_sbuf_integrity(s);
511 assert_sbuf_state(s, 0);
513 s->s_buf[s->s_len] = '\0';
514 SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
515 SBUF_SETFLAG(s, SBUF_FINISHED);
519 * Return a pointer to the sbuf data.
522 sbuf_data(struct sbuf *s)
524 assert_sbuf_integrity(s);
525 assert_sbuf_state(s, SBUF_FINISHED);
531 * Return the length of the sbuf data.
534 sbuf_len(struct sbuf *s)
536 assert_sbuf_integrity(s);
537 /* don't care if it's finished or not */
539 if (SBUF_HASOVERFLOWED(s))
545 * Clear an sbuf, free its buffer if necessary.
548 sbuf_delete(struct sbuf *s)
552 assert_sbuf_integrity(s);
553 /* don't care if it's finished or not */
555 if (SBUF_ISDYNAMIC(s))
557 isdyn = SBUF_ISDYNSTRUCT(s);