xref: /freebsd/sys/libkern/asprintf.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
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/param.h>
28 #include <sys/systm.h>
29 #include <sys/malloc.h>
30 
31 #include <machine/stdarg.h>
32 
33 int
34 vasprintf(char **buf, struct malloc_type *mtp, const char *format, va_list va)
35 {
36 	int len, ret;
37 	va_list tmp_va;
38 	char dummy;
39 
40 	va_copy(tmp_va, va);
41 	len = vsnprintf(&dummy, 0, format, tmp_va);
42 	va_end(tmp_va);
43 	if (len < 0) {
44 		*buf = NULL;
45 		return (len);
46 	}
47 
48 	/* Account for null terminator. */
49 	len += 1;
50 	*buf = malloc(len, mtp, M_NOWAIT);
51 	if (*buf == NULL)
52 		return (-1);
53 
54 	ret = vsnprintf(*buf, len, format, va);
55 	if (ret < 0) {
56 		free(*buf, mtp);
57 		*buf = NULL;
58 	}
59 
60 	return (ret);
61 }
62 
63 int
64 asprintf(char **buf, struct malloc_type *mtp, const char *format, ...)
65 {
66 	int ret;
67 	va_list va;
68 
69 	va_start(va, format);
70 	ret = vasprintf(buf, mtp, format, va);
71 	va_end(va);
72 
73 	return (ret);
74 }
75