xref: /freebsd/crypto/openssh/openbsd-compat/bsd-asprintf.c (revision cc16dea626cf2fc80cde667ac4798065108e596c)
1 /*
2  * Copyright (c) 2004 Darren Tucker.
3  *
4  * Based originally on asprintf.c from OpenBSD:
5  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include "includes.h"
21 
22 #ifndef HAVE_VASPRINTF
23 
24 #include <errno.h>
25 #include <stdarg.h>
26 #include <stdlib.h>
27 
28 #ifndef VA_COPY
29 # ifdef HAVE_VA_COPY
30 #  define VA_COPY(dest, src) va_copy(dest, src)
31 # else
32 #  ifdef HAVE___VA_COPY
33 #   define VA_COPY(dest, src) __va_copy(dest, src)
34 #  else
35 #   define VA_COPY(dest, src) (dest) = (src)
36 #  endif
37 # endif
38 #endif
39 
40 #define INIT_SZ	128
41 
42 int
43 vasprintf(char **str, const char *fmt, va_list ap)
44 {
45 	int ret = -1;
46 	va_list ap2;
47 	char *string, *newstr;
48 	size_t len;
49 
50 	VA_COPY(ap2, ap);
51 	if ((string = malloc(INIT_SZ)) == NULL)
52 		goto fail;
53 
54 	ret = vsnprintf(string, INIT_SZ, fmt, ap2);
55 	if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */
56 		*str = string;
57 	} else if (ret == INT_MAX || ret < 0) { /* Bad length */
58 		free(string);
59 		goto fail;
60 	} else {	/* bigger than initial, realloc allowing for nul */
61 		len = (size_t)ret + 1;
62 		if ((newstr = realloc(string, len)) == NULL) {
63 			free(string);
64 			goto fail;
65 		} else {
66 			va_end(ap2);
67 			VA_COPY(ap2, ap);
68 			ret = vsnprintf(newstr, len, fmt, ap2);
69 			if (ret >= 0 && (size_t)ret < len) {
70 				*str = newstr;
71 			} else { /* failed with realloc'ed string, give up */
72 				free(newstr);
73 				goto fail;
74 			}
75 		}
76 	}
77 	va_end(ap2);
78 	return (ret);
79 
80 fail:
81 	*str = NULL;
82 	errno = ENOMEM;
83 	va_end(ap2);
84 	return (-1);
85 }
86 #endif
87 
88 #ifndef HAVE_ASPRINTF
89 int asprintf(char **str, const char *fmt, ...)
90 {
91 	va_list ap;
92 	int ret;
93 
94 	*str = NULL;
95 	va_start(ap, fmt);
96 	ret = vasprintf(str, fmt, ap);
97 	va_end(ap);
98 
99 	return ret;
100 }
101 #endif
102