[dragonfly.git] / sys / kern / subr_sbuf.c

/*-
 * Copyright (c) 2000 Poul-Henning Kamp and Dag-Erling Coïdan Smørgrav
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer
 *    in this position and unchanged.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *      $FreeBSD: src/sys/kern/subr_sbuf.c,v 1.11.2.2 2002/03/12 01:01:07 archie Exp $
 *      $DragonFly: src/sys/kern/subr_sbuf.c,v 1.9 2006/12/22 08:08:25 swildner Exp $
 */

#include <sys/param.h>

#ifdef _KERNEL
#include <sys/ctype.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <machine/stdarg.h>
#else /* _KERNEL */
#include <ctype.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#endif /* _KERNEL */

#include <sys/sbuf.h>

#ifdef _KERNEL
MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers");
#define SBMALLOC(size)		kmalloc(size, M_SBUF, M_WAITOK)
#define SBFREE(buf)		kfree(buf, M_SBUF)
#else /* _KERNEL */
#define KASSERT(e, m)
#define SBMALLOC(size)		malloc(size)
#define SBFREE(buf)		free(buf)
#define kvsnprintf		vsnprintf
#endif /* _KERNEL */

/*
 * Predicates
 */
#define SBUF_ISDYNAMIC(s)	((s)->s_flags & SBUF_DYNAMIC)
#define SBUF_ISDYNSTRUCT(s)	((s)->s_flags & SBUF_DYNSTRUCT)
#define SBUF_ISFINISHED(s)	((s)->s_flags & SBUF_FINISHED)
#define SBUF_HASOVERFLOWED(s)	((s)->s_flags & SBUF_OVERFLOWED)
#define SBUF_HASROOM(s)		((s)->s_len < (s)->s_size - 1)
#define SBUF_FREESPACE(s)	((s)->s_size - (s)->s_len - 1)
#define SBUF_CANEXTEND(s)	((s)->s_flags & SBUF_AUTOEXTEND)

/*
 * Set / clear flags
 */
#define SBUF_SETFLAG(s, f)	do { (s)->s_flags |= (f); } while (0)
#define SBUF_CLEARFLAG(s, f)	do { (s)->s_flags &= ~(f); } while (0)

#define SBUF_MINEXTENDSIZE	16		/* Should be power of 2. */
#define SBUF_MAXEXTENDSIZE	PAGE_SIZE
#define SBUF_MAXEXTENDINCR	PAGE_SIZE

/*
 * Debugging support
 */
#if defined(_KERNEL) && defined(INVARIANTS)
static void
_assert_sbuf_integrity(const char *fun, struct sbuf *s)
{
	KASSERT(s != NULL,
	    ("%s called with a NULL sbuf pointer", fun));
	KASSERT(s->s_buf != NULL,
	    ("%s called with uninitialized or corrupt sbuf", fun));
	KASSERT(s->s_len < s->s_size,
	    ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
}

static void
_assert_sbuf_state(const char *fun, struct sbuf *s, int state)
{
	KASSERT((s->s_flags & SBUF_FINISHED) == state,
	    ("%s called with %sfinished or corrupt sbuf", fun,
	    (state ? "un" : "")));
}
#define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s))
#define assert_sbuf_state(s, i)	 _assert_sbuf_state(__func__, (s), (i))
#else /* _KERNEL && INVARIANTS */
#define assert_sbuf_integrity(s) do { } while (0)
#define assert_sbuf_state(s, i)	 do { } while (0)
#endif /* _KERNEL && INVARIANTS */

static int
sbuf_extendsize(int size)
{
	int newsize;

	newsize = SBUF_MINEXTENDSIZE;
	while (newsize < size) {
		if (newsize < SBUF_MAXEXTENDSIZE)
			newsize *= 2;
		else
			newsize += SBUF_MAXEXTENDINCR;
	}

	return (newsize);
}


/*
 * Extend an sbuf.
 */
static int
sbuf_extend(struct sbuf *s, int addlen)
{
	char *newbuf;
	int newsize;

	if (!SBUF_CANEXTEND(s))
		return (-1);

	newsize = sbuf_extendsize(s->s_size + addlen);
	newbuf = (char *)SBMALLOC(newsize);
	if (newbuf == NULL)
		return (-1);
	bcopy(s->s_buf, newbuf, s->s_size);
	if (SBUF_ISDYNAMIC(s))
		SBFREE(s->s_buf);
	else
		SBUF_SETFLAG(s, SBUF_DYNAMIC);
	s->s_buf = newbuf;
	s->s_size = newsize;
	return (0);
}

/*
 * Initialize an sbuf.
 * If buf is non-NULL, it points to a static or already-allocated string
 * big enough to hold at least length characters.
 */
struct sbuf *
sbuf_new(struct sbuf *s, char *buf, int length, int flags)
{
	KASSERT(length >= 0,
	    ("attempt to create an sbuf of negative length (%d)", length));
	KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
	    ("%s called with invalid flags", __func__));

	flags &= SBUF_USRFLAGMSK;
	if (s == NULL) {
		s = (struct sbuf *)SBMALLOC(sizeof *s);
		if (s == NULL)
			return (NULL);
		bzero(s, sizeof *s);
		s->s_flags = flags;
		SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
	} else {
		bzero(s, sizeof *s);
		s->s_flags = flags;
	}
	s->s_size = length;
	if (buf) {
		s->s_buf = buf;
		return (s);
	}
	if (flags & SBUF_AUTOEXTEND)
		s->s_size = sbuf_extendsize(s->s_size);
	s->s_buf = (char *)SBMALLOC(s->s_size);
	if (s->s_buf == NULL) {
		if (SBUF_ISDYNSTRUCT(s))
			SBFREE(s);
		return (NULL);
	}
	SBUF_SETFLAG(s, SBUF_DYNAMIC);
	return (s);
}

#ifdef _KERNEL
/*
 * Create an sbuf with uio data
 */
struct sbuf *
sbuf_uionew(struct sbuf *s, struct uio *uio, int *error)
{
	KASSERT(uio != NULL,
	    ("%s called with NULL uio pointer", __func__));
	KASSERT(error != NULL,
	    ("%s called with NULL error pointer", __func__));

	s = sbuf_new(s, NULL, uio->uio_resid + 1, 0);
	if (s == NULL) {
		*error = ENOMEM;
		return (NULL);
	}
	*error = uiomove(s->s_buf, uio->uio_resid, uio);
	if (*error != 0) {
		sbuf_delete(s);
		return (NULL);
	}
	s->s_len = s->s_size - 1;
	*error = 0;
	return (s);
}
#endif

/*
 * Clear an sbuf and reset its position.
 */
void
sbuf_clear(struct sbuf *s)
{
	assert_sbuf_integrity(s);
	/* don't care if it's finished or not */

	SBUF_CLEARFLAG(s, SBUF_FINISHED);
	SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
	s->s_len = 0;
}

/*
 * Set the sbuf's end position to an arbitrary value.
 * Effectively truncates the sbuf at the new position.
 */
int
sbuf_setpos(struct sbuf *s, int pos)
{
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);
	
	KASSERT(pos >= 0,
	    ("attempt to seek to a negative position (%d)", pos));
	KASSERT(pos < s->s_size,
	    ("attempt to seek past end of sbuf (%d >= %d)", pos, s->s_size));
	       
	if (pos < 0 || pos > s->s_len)
		return (-1);
	s->s_len = pos;
	return (0);
}

/*
 * Append a byte string to an sbuf.
 */
int
sbuf_bcat(struct sbuf *s, const char *str, size_t len)
{
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);
	
	if (SBUF_HASOVERFLOWED(s))
		return (-1);
	
	for (; len; len--) {
		if (!SBUF_HASROOM(s) && sbuf_extend(s, len) < 0)
			break;
		s->s_buf[s->s_len++] = *str++;
	}
	if (len) {
		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
		return (-1);
	}
	return (0);
}

#ifdef _KERNEL
/*
 * Copy a byte string from userland into an sbuf.
 */
int
sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
{
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);

	if (SBUF_HASOVERFLOWED(s))
		return (-1);

	if (len == 0)
		return (0);
	if (len > SBUF_FREESPACE(s)) {
		sbuf_extend(s, len - SBUF_FREESPACE(s));
		len = MIN(len, SBUF_FREESPACE(s));
	}
	if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
		return (-1);
	s->s_len += len;
	
	return (0);
}
#endif

/*
 * Copy a byte string into an sbuf.
 */
int
sbuf_bcpy(struct sbuf *s, const char *str, size_t len)
{
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);
	
	sbuf_clear(s);
	return (sbuf_bcat(s, str, len));
}

/*
 * Append a string to an sbuf.
 */
int
sbuf_cat(struct sbuf *s, const char *str)
{
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);
	
	if (SBUF_HASOVERFLOWED(s))
		return (-1);
	
	while (*str) {
		if (!SBUF_HASROOM(s) && sbuf_extend(s, strlen(str)) < 0)
			break;
		s->s_buf[s->s_len++] = *str++;
	}
	if (*str) {
		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
		return (-1);
	}
	return (0);
}

#ifdef _KERNEL
/*
 * Append a string from userland to an sbuf.
 */
int
sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
{
	size_t done;
	
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);

	if (SBUF_HASOVERFLOWED(s))
		return (-1);

	if (len == 0)
		len = SBUF_FREESPACE(s);	/* XXX return 0? */
	if (len > SBUF_FREESPACE(s)) {
		sbuf_extend(s, len);
		len = MIN(len, SBUF_FREESPACE(s));
	}
	switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
	case ENAMETOOLONG:
		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
		/* fall through */
	case 0:
		s->s_len += done - 1;
		break;
	default:
		return (-1);	/* XXX */
	}
	
	return (0);
}
#endif

/*
 * Copy a string into an sbuf.
 */
int
sbuf_cpy(struct sbuf *s, const char *str)
{
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);
	
	sbuf_clear(s);
	return (sbuf_cat(s, str));
}

/*
 * Format the given argument list and append the resulting string to an sbuf.
 */
int
sbuf_vprintf(struct sbuf *s, const char *fmt, __va_list ap)
{
	int len;
	__va_list ap_copy;

	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);

	KASSERT(fmt != NULL,
	    ("%s called with a NULL format string", __func__));

	if (SBUF_HASOVERFLOWED(s))
		return (-1);

	do {
		__va_copy(ap_copy, ap);
		len = kvsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
				 fmt, ap_copy);
		__va_end(ap_copy);
	} while (len > SBUF_FREESPACE(s) &&
	    sbuf_extend(s, len - SBUF_FREESPACE(s)) == 0);

	/*
	 * s->s_len is the length of the string, without the terminating nul.
	 * When updating s->s_len, we must subtract 1 from the length that
	 * we passed into kvsnprintf() because that length includes the
	 * terminating nul.
	 *
	 * kvsnprintf() returns the amount that would have been copied,
	 * given sufficient space, hence the min() calculation below.
	 */
	s->s_len += MIN(len, SBUF_FREESPACE(s));
	if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
		SBUF_SETFLAG(s, SBUF_OVERFLOWED);

	KASSERT(s->s_len < s->s_size,
	    ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));

	if (SBUF_HASOVERFLOWED(s))
		return (-1);
	return (0);
}

/*
 * Format the given arguments and append the resulting string to an sbuf.
 */
int
sbuf_printf(struct sbuf *s, const char *fmt, ...)
{
	__va_list ap;
	int result;

	__va_start(ap, fmt);
	result = sbuf_vprintf(s, fmt, ap);
	__va_end(ap);
	return(result);
}

/*
 * Append a character to an sbuf.
 */
int
sbuf_putc(struct sbuf *s, int c)
{
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);
	
	if (SBUF_HASOVERFLOWED(s))
		return (-1);
	
	if (!SBUF_HASROOM(s) && sbuf_extend(s, 1) < 0) {
		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
		return (-1);
	}
	if (c != '\0')
	    s->s_buf[s->s_len++] = c;
	return (0);
}

/*
 * Trim whitespace characters from end of an sbuf.
 */
int
sbuf_trim(struct sbuf *s)
{
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);
	
	if (SBUF_HASOVERFLOWED(s))
		return (-1);
	
	while (s->s_len && isspace(s->s_buf[s->s_len-1]))
		--s->s_len;

	return (0);
}

/*
 * Check if an sbuf overflowed
 */
int
sbuf_overflowed(struct sbuf *s)
{
    return SBUF_HASOVERFLOWED(s);
}

/*
 * Finish off an sbuf.
 */
void
sbuf_finish(struct sbuf *s)
{
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, 0);
	
	s->s_buf[s->s_len] = '\0';
	SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
	SBUF_SETFLAG(s, SBUF_FINISHED);
}

/*
 * Return a pointer to the sbuf data.
 */
char *
sbuf_data(struct sbuf *s)
{
	assert_sbuf_integrity(s);
	assert_sbuf_state(s, SBUF_FINISHED);
	
	return s->s_buf;
}

/*
 * Return the length of the sbuf data.
 */
int
sbuf_len(struct sbuf *s)
{
	assert_sbuf_integrity(s);
	/* don't care if it's finished or not */
	
	if (SBUF_HASOVERFLOWED(s))
		return (-1);
	return s->s_len;
}

/*
 * Clear an sbuf, free its buffer if necessary.
 */
void
sbuf_delete(struct sbuf *s)
{
	int isdyn;

	assert_sbuf_integrity(s);
	/* don't care if it's finished or not */
	
	if (SBUF_ISDYNAMIC(s))
		SBFREE(s->s_buf);
	isdyn = SBUF_ISDYNSTRUCT(s);
	bzero(s, sizeof *s);
	if (isdyn)
		SBFREE(s);
}
Commit	Line	Data
984263bc MD	1	/*-
	2	* Copyright (c) 2000 Poul-Henning Kamp and Dag-Erling Coïdan Smørgrav
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	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.
	16	*
	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.
	27	*
	28	* $FreeBSD: src/sys/kern/subr_sbuf.c,v 1.11.2.2 2002/03/12 01:01:07 archie Exp $
219ffab2	29	* $DragonFly: src/sys/kern/subr_sbuf.c,v 1.9 2006/12/22 08:08:25 swildner Exp $
984263bc MD	30	*/
	31
	32	#include <sys/param.h>
	33
	34	#ifdef _KERNEL
	35	#include <sys/ctype.h>
	36	#include <sys/kernel.h>
	37	#include <sys/malloc.h>
	38	#include <sys/systm.h>
	39	#include <sys/uio.h>
	40	#include <machine/stdarg.h>
	41	#else /* _KERNEL */
	42	#include <ctype.h>
	43	#include <stdarg.h>
	44	#include <stdio.h>
	45	#include <stdlib.h>
	46	#include <string.h>
	47	#endif /* _KERNEL */
	48
	49	#include <sys/sbuf.h>
	50
	51	#ifdef _KERNEL
	52	MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers");
efda3bd0 MD	53	#define SBMALLOC(size) kmalloc(size, M_SBUF, M_WAITOK)
efda3bd0 MD	54	#define SBFREE(buf) kfree(buf, M_SBUF)
984263bc MD	55	#else /* _KERNEL */
	56	#define KASSERT(e, m)
	57	#define SBMALLOC(size) malloc(size)
	58	#define SBFREE(buf) free(buf)
219ffab2	59	#define kvsnprintf vsnprintf
984263bc MD	60	#endif /* _KERNEL */
	61
	62	/*
	63	* Predicates
	64	*/
	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)
	72
	73	/*
	74	* Set / clear flags
	75	*/
	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)
	78
	79	#define SBUF_MINEXTENDSIZE 16 /* Should be power of 2. */
	80	#define SBUF_MAXEXTENDSIZE PAGE_SIZE
	81	#define SBUF_MAXEXTENDINCR PAGE_SIZE
	82
	83	/*
	84	* Debugging support
	85	*/
	86	#if defined(_KERNEL) && defined(INVARIANTS)
	87	static void
22380de3	88	_assert_sbuf_integrity(const char fun, struct sbuf s)
984263bc MD	89	{
	90	KASSERT(s != NULL,
	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));
	96	}
	97
	98	static void
22380de3	99	_assert_sbuf_state(const char fun, struct sbuf s, int state)
984263bc MD	100	{
	101	KASSERT((s->s_flags & SBUF_FINISHED) == state,
	102	("%s called with %sfinished or corrupt sbuf", fun,
	103	(state ? "un" : "")));
	104	}
5e2195bf JS	105	#define assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s))
5e2195bf JS	106	#define assert_sbuf_state(s, i) _assert_sbuf_state(__func__, (s), (i))
984263bc MD	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 */
	111
	112	static int
	113	sbuf_extendsize(int size)
	114	{
	115	int newsize;
	116
	117	newsize = SBUF_MINEXTENDSIZE;
	118	while (newsize < size) {
	119	if (newsize < SBUF_MAXEXTENDSIZE)
	120	newsize *= 2;
	121	else
	122	newsize += SBUF_MAXEXTENDINCR;
	123	}
	124
	125	return (newsize);
	126	}
	127
	128
	129	/*
	130	* Extend an sbuf.
	131	*/
	132	static int
	133	sbuf_extend(struct sbuf *s, int addlen)
	134	{
	135	char *newbuf;
	136	int newsize;
	137
	138	if (!SBUF_CANEXTEND(s))
	139	return (-1);
	140
	141	newsize = sbuf_extendsize(s->s_size + addlen);
	142	newbuf = (char *)SBMALLOC(newsize);
	143	if (newbuf == NULL)
	144	return (-1);
	145	bcopy(s->s_buf, newbuf, s->s_size);
	146	if (SBUF_ISDYNAMIC(s))
	147	SBFREE(s->s_buf);
	148	else
	149	SBUF_SETFLAG(s, SBUF_DYNAMIC);
	150	s->s_buf = newbuf;
	151	s->s_size = newsize;
	152	return (0);
	153	}
	154
	155	/*
	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.
	159	*/
	160	struct sbuf *
	161	sbuf_new(struct sbuf s, char buf, int length, int flags)
	162	{
	163	KASSERT(length >= 0,
	164	("attempt to create an sbuf of negative length (%d)", length));
	165	KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
5e2195bf	166	("%s called with invalid flags", __func__));
984263bc MD	167
	168	flags &= SBUF_USRFLAGMSK;
	169	if (s == NULL) {
	170	s = (struct sbuf )SBMALLOC(sizeof s);
	171	if (s == NULL)
	172	return (NULL);
	173	bzero(s, sizeof *s);
	174	s->s_flags = flags;
	175	SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
	176	} else {
	177	bzero(s, sizeof *s);
	178	s->s_flags = flags;
	179	}
	180	s->s_size = length;
	181	if (buf) {
	182	s->s_buf = buf;
	183	return (s);
	184	}
	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))
	190	SBFREE(s);
	191	return (NULL);
	192	}
	193	SBUF_SETFLAG(s, SBUF_DYNAMIC);
	194	return (s);
	195	}
	196
	197	#ifdef _KERNEL
	198	/*
	199	* Create an sbuf with uio data
	200	*/
	201	struct sbuf *
	202	sbuf_uionew(struct sbuf s, struct uio uio, int *error)
	203	{
	204	KASSERT(uio != NULL,
5e2195bf	205	("%s called with NULL uio pointer", __func__));
984263bc	206	KASSERT(error != NULL,
5e2195bf	207	("%s called with NULL error pointer", __func__));
984263bc MD	208
	209	s = sbuf_new(s, NULL, uio->uio_resid + 1, 0);
	210	if (s == NULL) {
	211	*error = ENOMEM;
	212	return (NULL);
	213	}
	214	*error = uiomove(s->s_buf, uio->uio_resid, uio);
	215	if (*error != 0) {
	216	sbuf_delete(s);
	217	return (NULL);
	218	}
	219	s->s_len = s->s_size - 1;
	220	*error = 0;
	221	return (s);
	222	}
	223	#endif
	224
	225	/*
	226	* Clear an sbuf and reset its position.
	227	*/
	228	void
	229	sbuf_clear(struct sbuf *s)
	230	{
	231	assert_sbuf_integrity(s);
	232	/* don't care if it's finished or not */
	233
	234	SBUF_CLEARFLAG(s, SBUF_FINISHED);
	235	SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
	236	s->s_len = 0;
	237	}
	238
	239	/*
	240	* Set the sbuf's end position to an arbitrary value.
	241	* Effectively truncates the sbuf at the new position.
	242	*/
	243	int
	244	sbuf_setpos(struct sbuf *s, int pos)
	245	{
	246	assert_sbuf_integrity(s);
	247	assert_sbuf_state(s, 0);
	248
	249	KASSERT(pos >= 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));
	253
	254	if (pos < 0 \|\| pos > s->s_len)
	255	return (-1);
	256	s->s_len = pos;
	257	return (0);
	258	}
	259
	260	/*
	261	* Append a byte string to an sbuf.
	262	*/
	263	int
	264	sbuf_bcat(struct sbuf s, const char str, size_t len)
	265	{
	266	assert_sbuf_integrity(s);
	267	assert_sbuf_state(s, 0);
	268
	269	if (SBUF_HASOVERFLOWED(s))
	270	return (-1);
	271
272	for (; len; len--) {
273	if (!SBUF_HASROOM(s) && sbuf_extend(s, len) < 0)
274	break;
275	s->s_buf[s->s_len++] = *str++;
276	}
277	if (len) {
278	SBUF_SETFLAG(s, SBUF_OVERFLOWED);
279	return (-1);
280	}
281	return (0);
282	}
283
284	#ifdef _KERNEL
285	/*
286	* Copy a byte string from userland into an sbuf.
287	*/
288	int
289	sbuf_bcopyin(struct sbuf s, const void uaddr, size_t len)
290	{
291	assert_sbuf_integrity(s);
292	assert_sbuf_state(s, 0);
293
294	if (SBUF_HASOVERFLOWED(s))
295	return (-1);
296
297	if (len == 0)
298	return (0);
299	if (len > SBUF_FREESPACE(s)) {
300	sbuf_extend(s, len - SBUF_FREESPACE(s));
7686bcf5	301	len = MIN(len, SBUF_FREESPACE(s));
984263bc MD	302	}
	303	if (copyin(uaddr, s->s_buf + s->s_len, len) != 0)
	304	return (-1);
	305	s->s_len += len;
	306
	307	return (0);
	308	}
	309	#endif
	310
	311	/*
	312	* Copy a byte string into an sbuf.
	313	*/
	314	int
	315	sbuf_bcpy(struct sbuf s, const char str, size_t len)
	316	{
	317	assert_sbuf_integrity(s);
	318	assert_sbuf_state(s, 0);
	319
	320	sbuf_clear(s);
	321	return (sbuf_bcat(s, str, len));
	322	}
	323
	324	/*
	325	* Append a string to an sbuf.
	326	*/
	327	int
	328	sbuf_cat(struct sbuf s, const char str)
	329	{
	330	assert_sbuf_integrity(s);
	331	assert_sbuf_state(s, 0);
	332
	333	if (SBUF_HASOVERFLOWED(s))
	334	return (-1);
	335
	336	while (*str) {
	337	if (!SBUF_HASROOM(s) && sbuf_extend(s, strlen(str)) < 0)
	338	break;
	339	s->s_buf[s->s_len++] = *str++;
	340	}
	341	if (*str) {
	342	SBUF_SETFLAG(s, SBUF_OVERFLOWED);
	343	return (-1);
	344	}
	345	return (0);
	346	}
	347
	348	#ifdef _KERNEL
	349	/*
	350	* Append a string from userland to an sbuf.
	351	*/
	352	int
	353	sbuf_copyin(struct sbuf s, const void uaddr, size_t len)
	354	{
	355	size_t done;
	356
	357	assert_sbuf_integrity(s);
	358	assert_sbuf_state(s, 0);
	359
	360	if (SBUF_HASOVERFLOWED(s))
	361	return (-1);
	362
	363	if (len == 0)
	364	len = SBUF_FREESPACE(s); /* XXX return 0? */
	365	if (len > SBUF_FREESPACE(s)) {
366	sbuf_extend(s, len);
7686bcf5	367	len = MIN(len, SBUF_FREESPACE(s));
984263bc MD	368	}
	369	switch (copyinstr(uaddr, s->s_buf + s->s_len, len + 1, &done)) {
	370	case ENAMETOOLONG:
	371	SBUF_SETFLAG(s, SBUF_OVERFLOWED);
	372	/* fall through */
	373	case 0:
	374	s->s_len += done - 1;
	375	break;
	376	default:
	377	return (-1); /* XXX */
	378	}
	379
	380	return (0);
	381	}
	382	#endif
	383
	384	/*
	385	* Copy a string into an sbuf.
	386	*/
	387	int
	388	sbuf_cpy(struct sbuf s, const char str)
	389	{
	390	assert_sbuf_integrity(s);
	391	assert_sbuf_state(s, 0);
	392
	393	sbuf_clear(s);
	394	return (sbuf_cat(s, str));
	395	}
	396
	397	/*
	398	* Format the given argument list and append the resulting string to an sbuf.
	399	*/
	400	int
e2565a42	401	sbuf_vprintf(struct sbuf s, const char fmt, __va_list ap)
984263bc MD	402	{
984263bc MD	403	int len;
c56fb118	404	__va_list ap_copy;
95d4ea52	405
984263bc MD	406	assert_sbuf_integrity(s);
	407	assert_sbuf_state(s, 0);
	408
	409	KASSERT(fmt != NULL,
5e2195bf	410	("%s called with a NULL format string", __func__));
984263bc MD	411
	412	if (SBUF_HASOVERFLOWED(s))
	413	return (-1);
	414
	415	do {
c56fb118	416	__va_copy(ap_copy, ap);
379210cb	417	len = kvsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
c56fb118 MC	418	fmt, ap_copy);
c56fb118 MC	419	__va_end(ap_copy);
984263bc MD	420	} while (len > SBUF_FREESPACE(s) &&
	421	sbuf_extend(s, len - SBUF_FREESPACE(s)) == 0);
	422
	423	/*
	424	* s->s_len is the length of the string, without the terminating nul.
	425	* When updating s->s_len, we must subtract 1 from the length that
379210cb	426	* we passed into kvsnprintf() because that length includes the
984263bc MD	427	* terminating nul.
984263bc MD	428	*
379210cb	429	* kvsnprintf() returns the amount that would have been copied,
984263bc MD	430	* given sufficient space, hence the min() calculation below.
984263bc MD	431	*/
7686bcf5	432	s->s_len += MIN(len, SBUF_FREESPACE(s));
984263bc MD	433	if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
	434	SBUF_SETFLAG(s, SBUF_OVERFLOWED);
	435
	436	KASSERT(s->s_len < s->s_size,
	437	("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
	438
	439	if (SBUF_HASOVERFLOWED(s))
	440	return (-1);
	441	return (0);
	442	}
	443
	444	/*
	445	* Format the given arguments and append the resulting string to an sbuf.
	446	*/
	447	int
	448	sbuf_printf(struct sbuf s, const char fmt, ...)
	449	{
e2565a42	450	__va_list ap;
984263bc MD	451	int result;
984263bc MD	452
e2565a42	453	__va_start(ap, fmt);
984263bc	454	result = sbuf_vprintf(s, fmt, ap);
e2565a42	455	__va_end(ap);
984263bc MD	456	return(result);
	457	}
	458
	459	/*
	460	* Append a character to an sbuf.
	461	*/
	462	int
	463	sbuf_putc(struct sbuf *s, int c)
	464	{
	465	assert_sbuf_integrity(s);
	466	assert_sbuf_state(s, 0);
	467
	468	if (SBUF_HASOVERFLOWED(s))
	469	return (-1);
	470
	471	if (!SBUF_HASROOM(s) && sbuf_extend(s, 1) < 0) {
	472	SBUF_SETFLAG(s, SBUF_OVERFLOWED);
	473	return (-1);
	474	}
	475	if (c != '\0')
	476	s->s_buf[s->s_len++] = c;
	477	return (0);
	478	}
	479
	480	/*
	481	* Trim whitespace characters from end of an sbuf.
	482	*/
	483	int
	484	sbuf_trim(struct sbuf *s)
	485	{
	486	assert_sbuf_integrity(s);
	487	assert_sbuf_state(s, 0);
	488
	489	if (SBUF_HASOVERFLOWED(s))
	490	return (-1);
	491
	492	while (s->s_len && isspace(s->s_buf[s->s_len-1]))
	493	--s->s_len;
	494
	495	return (0);
	496	}
	497
	498	/*
	499	* Check if an sbuf overflowed
	500	*/
	501	int
	502	sbuf_overflowed(struct sbuf *s)
	503	{
	504	return SBUF_HASOVERFLOWED(s);
	505	}
	506
	507	/*
	508	* Finish off an sbuf.
	509	*/
	510	void
	511	sbuf_finish(struct sbuf *s)
	512	{
	513	assert_sbuf_integrity(s);
	514	assert_sbuf_state(s, 0);
	515
	516	s->s_buf[s->s_len] = '\0';
	517	SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
	518	SBUF_SETFLAG(s, SBUF_FINISHED);
	519	}
520
521	/*
522	* Return a pointer to the sbuf data.
523	*/
524	char *
525	sbuf_data(struct sbuf *s)
526	{
527	assert_sbuf_integrity(s);
528	assert_sbuf_state(s, SBUF_FINISHED);
529
530	return s->s_buf;
531	}
532
533	/*
534	* Return the length of the sbuf data.
535	*/
536	int
537	sbuf_len(struct sbuf *s)
538	{
539	assert_sbuf_integrity(s);
540	/* don't care if it's finished or not */
541
542	if (SBUF_HASOVERFLOWED(s))
543	return (-1);
544	return s->s_len;
545	}
546
547	/*
548	* Clear an sbuf, free its buffer if necessary.
549	*/
550	void
551	sbuf_delete(struct sbuf *s)
552	{
553	int isdyn;
554
555	assert_sbuf_integrity(s);
556	/* don't care if it's finished or not */
557
558	if (SBUF_ISDYNAMIC(s))
559	SBFREE(s->s_buf);
560	isdyn = SBUF_ISDYNSTRUCT(s);
561	bzero(s, sizeof *s);
562	if (isdyn)
563	SBFREE(s);
564	}