asprintf.c revision 288766 
1/*-
2 * Copyright (c) 2013-2015 Sandvine Inc.  All rights reserved.
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 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/10/sys/libkern/asprintf.c 288766 2015-10-05 09:46:23Z mav $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/malloc.h>
33
34#include <machine/stdarg.h>
35
36int
37vasprintf(char **buf, struct malloc_type *mtp, const char *format, va_list va)
38{
39	int len, ret;
40	va_list tmp_va;
41	char dummy;
42
43	va_copy(tmp_va, va);
44	len = vsnprintf(&dummy, 0, format, tmp_va);
45	va_end(tmp_va);
46	if (len < 0) {
47		*buf = NULL;
48		return (len);
49	}
50
51	/* Account for null terminator. */
52	len += 1;
53	*buf = malloc(len, mtp, M_NOWAIT);
54	if (*buf == NULL)
55		return (-1);
56
57	ret = vsnprintf(*buf, len, format, va);
58	if (ret < 0) {
59		free(*buf, mtp);
60		*buf = NULL;
61	}
62
63	return (ret);
64}
65
66int
67asprintf(char **buf, struct malloc_type *mtp, const char *format, ...)
68{
69	int ret;
70	va_list va;
71
72	va_start(va, format);
73	ret = vasprintf(buf, mtp, format, va);
74	va_end(va);
75
76	return (ret);
77}
78