/*
* Finish off an sbuf.
*/
int
sbuf_finish(struct sbuf *s)
{
assert_sbuf_integrity(s);
assert_sbuf_state(s, 0);
s->s_buf[s->s_len] = '\0';
if (SBUF_NULINCLUDED(s))
s->s_len++;
if (s->s_drain_func != NULL) {
while (s->s_len > 0 && s->s_error == 0)
s->s_error = sbuf_drain(s);
}
SBUF_SETFLAG(s, SBUF_FINISHED);
#ifdef _KERNEL
return (s->s_error);
#else
if (s->s_error != 0) {
errno = s->s_error;
return (-1);
}
return (0);
#endif
}
/*
* Append a byte to an sbuf. This is the core function for appending
* to an sbuf and is the main place that deals with extending the
* buffer and marking overflow.
*/
static void
sbuf_put_byte(struct sbuf *s, int c)
{
assert_sbuf_integrity(s);
assert_sbuf_state(s, 0);
if (s->s_error != 0)
return;
if (SBUF_FREESPACE(s) <= 0) {
/*
* If there is a drain, use it, otherwise extend the
* buffer.
*/
if (s->s_drain_func != NULL)
(void)sbuf_drain(s);
else if (sbuf_extend(s, 1) < 0)
s->s_error = ENOMEM;
if (s->s_error != 0)
return;
}
s->s_buf[s->s_len++] = c;
if (SBUF_ISSECTION(s))
s->s_sect_len++;
}
/*
* Append bytes to an sbuf. This is the core function for appending
* to an sbuf and is the main place that deals with extending the
* buffer and marking overflow.
*/
static void
sbuf_put_bytes(struct sbuf *s, const char *buf, size_t len)
{
size_t n;
assert_sbuf_integrity(s);
assert_sbuf_state(s, 0);
if (s->s_error != 0)
return;
while (len > 0) {
if (SBUF_FREESPACE(s) <= 0) {
/*
* If there is a drain, use it, otherwise extend the
* buffer.
*/
if (s->s_drain_func != NULL)
(void)sbuf_drain(s);
else if (sbuf_extend(s, len > INT_MAX ? INT_MAX : len)
< 0)
s->s_error = ENOMEM;
if (s->s_error != 0)
return;
}
n = SBUF_FREESPACE(s);
if (len < n)
n = len;
memcpy(&s->s_buf[s->s_len], buf, n);
s->s_len += n;
if (SBUF_ISSECTION(s))
s->s_sect_len += n;
len -= n;
buf += n;
}
}
/*
* Append a non-NUL character to an sbuf. This prototype signature is
* suitable for use with kvcprintf(9).
*/
static void
sbuf_putc_func(int c, void *arg)
{
if (c != '\0')
sbuf_put_byte(arg, c);
}
int
sbuf_vprintf(struct sbuf *s, const char *fmt, __va_list ap)
{
assert_sbuf_integrity(s);
assert_sbuf_state(s, 0);
KASSERT(fmt != NULL,
("%s called with a NULL format string", __func__));
(void)kvcprintf(fmt, sbuf_putc_func, s, 10, ap);
if (s->s_error != 0)
return (-1);
return (0);
}
#else /* !_KERNEL */
int
sbuf_vprintf(struct sbuf *s, const char *fmt, __va_list ap)
{
__va_list ap_copy;
int error, len;
assert_sbuf_integrity(s);
assert_sbuf_state(s, 0);
KASSERT(fmt != NULL,
("%s called with a NULL format string", __func__));
if (s->s_error != 0)
return (-1);
/*
* For the moment, there is no way to get vsnprintf(3) to hand
* back a character at a time, to push everything into
* sbuf_putc_func() as was done for the kernel.
*
* In userspace, while drains are useful, there's generally
* not a problem attempting to malloc(3) on out of space. So
* expand a userland sbuf if there is not enough room for the
* data produced by sbuf_[v]printf(3).
*/
error = 0;
do {
va_copy(ap_copy, ap);
len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
fmt, ap_copy);
__va_end(ap_copy);
if (SBUF_FREESPACE(s) >= len)
break;
/* Cannot print with the current available space. */
if (s->s_drain_func != NULL && s->s_len > 0)
error = sbuf_drain(s);
else
error = sbuf_extend(s, len - SBUF_FREESPACE(s));
} while (error == 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, so don't over-increment s_len.
*/
if (SBUF_FREESPACE(s) < len)
len = SBUF_FREESPACE(s);
s->s_len += len;
if (SBUF_ISSECTION(s))
s->s_sect_len += len;
if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
s->s_error = ENOMEM;
KASSERT(s->s_len < s->s_size,
("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
if (s->s_error != 0)
return (-1);
return (0);
}
