1 files changed, 560 insertions, 0 deletions
diff --git a/sys/kern/subr_sbuf.c b/sys/kern/subr_sbuf.c
new file mode 100644
index 0000000..6c910e6
--- /dev/null
+++ b/sys/kern/subr_sbuf.c
@@ -0,0 +1,560 @@
+/*-
+ * 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.
+ *
+ *      $FreeBSD$
+ */
+
+#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)		malloc(size, M_SBUF, M_WAITOK)
+#define	SBFREE(buf)		free(buf, M_SBUF)
+#else /* _KERNEL */
+#define	KASSERT(e, m)
+#define	SBMALLOC(size)		malloc(size)
+#define	SBFREE(buf)		free(buf)
+#define	min(x,y)		MIN(x,y)
+#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;
+
+	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 {
+		len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
+		    fmt, ap);
+	} 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 vsnprintf() because that length includes the
+	 * terminating nul.
+	 *
+	 * vsnprintf() 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);
+}