1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /* util/support/printf.c */
3 /*
4 * Copyright 2003, 2004, 2005, 2007, 2008 Massachusetts Institute of
5 * Technology. All Rights Reserved.
6 *
7 * Export of this software from the United States of America may
8 * require a specific license from the United States Government.
9 * It is the responsibility of any person or organization contemplating
10 * export to obtain such a license before exporting.
11 *
12 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
13 * distribute this software and its documentation for any purpose and
14 * without fee is hereby granted, provided that the above copyright
15 * notice appear in all copies and that both that copyright notice and
16 * this permission notice appear in supporting documentation, and that
17 * the name of M.I.T. not be used in advertising or publicity pertaining
18 * to distribution of the software without specific, written prior
19 * permission. Furthermore if you modify this software you must label
20 * your software as modified software and not distribute it in such a
21 * fashion that it might be confused with the original M.I.T. software.
22 * M.I.T. makes no representations about the suitability of
23 * this software for any purpose. It is provided "as is" without express
24 * or implied warranty.
25 */
26
27 /* Provide {,v}asprintf for platforms that don't have them. */
28
29 #include "k5-platform.h"
30
31 /* On error: BSD: Set *ret to NULL. GNU: *ret is undefined.
32
33 Since we want to be able to use the GNU version directly, we need
34 provide only the weaker guarantee in this version. */
35 int
krb5int_vasprintf(char ** ret,const char * format,va_list ap)36 krb5int_vasprintf(char **ret, const char *format, va_list ap)
37 {
38 va_list ap2;
39 char *str = NULL, *nstr;
40 size_t len = 80;
41 int len2;
42
43 while (1) {
44 if (len >= INT_MAX || len == 0)
45 goto fail;
46 nstr = realloc(str, len);
47 if (nstr == NULL)
48 goto fail;
49 str = nstr;
50 va_copy(ap2, ap);
51 len2 = vsnprintf(str, len, format, ap2);
52 va_end(ap2);
53 /* ISO C vsnprintf returns the needed length. Some old
54 vsnprintf implementations return -1 on truncation. */
55 if (len2 < 0) {
56 /* Don't know how much space we need, just that we didn't
57 supply enough; get a bigger buffer and try again. */
58 if (len <= SIZE_MAX/2)
59 len *= 2;
60 else if (len < SIZE_MAX)
61 len = SIZE_MAX;
62 else
63 goto fail;
64 } else if ((unsigned int) len2 >= SIZE_MAX) {
65 /* Need more space than we can request. */
66 goto fail;
67 } else if ((size_t) len2 >= len) {
68 /* Need more space, but we know how much. */
69 len = (size_t) len2 + 1;
70 } else {
71 /* Success! */
72 break;
73 }
74 }
75 /* We might've allocated more than we need, if we're still using
76 the initial guess, or we got here by doubling. */
77 if ((size_t) len2 < len - 1) {
78 nstr = realloc(str, (size_t) len2 + 1);
79 if (nstr)
80 str = nstr;
81 }
82 *ret = str;
83 return len2;
84
85 fail:
86 free(str);
87 return -1;
88 }
89
90 int
krb5int_asprintf(char ** ret,const char * format,...)91 krb5int_asprintf(char **ret, const char *format, ...)
92 {
93 va_list ap;
94 int n;
95
96 va_start(ap, format);
97 n = krb5int_vasprintf(ret, format, ap);
98 va_end(ap);
99 return n;
100 }
101