xref: /freebsd/sys/libkern/asprintf.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
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 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/malloc.h>
31 
32 #include <machine/stdarg.h>
33 
34 int
35 vasprintf(char **buf, struct malloc_type *mtp, const char *format, va_list va)
36 {
37 	int len, ret;
38 	va_list tmp_va;
39 	char dummy;
40 
41 	va_copy(tmp_va, va);
42 	len = vsnprintf(&dummy, 0, format, tmp_va);
43 	va_end(tmp_va);
44 	if (len < 0) {
45 		*buf = NULL;
46 		return (len);
47 	}
48 
49 	/* Account for null terminator. */
50 	len += 1;
51 	*buf = malloc(len, mtp, M_NOWAIT);
52 	if (*buf == NULL)
53 		return (-1);
54 
55 	ret = vsnprintf(*buf, len, format, va);
56 	if (ret < 0) {
57 		free(*buf, mtp);
58 		*buf = NULL;
59 	}
60 
61 	return (ret);
62 }
63 
64 int
65 asprintf(char **buf, struct malloc_type *mtp, const char *format, ...)
66 {
67 	int ret;
68 	va_list va;
69 
70 	va_start(va, format);
71 	ret = vasprintf(buf, mtp, format, va);
72 	va_end(va);
73 
74 	return (ret);
75 }
76