1 /* $OpenBSD: tempnam.c,v 1.19 2015/08/31 02:53:57 guenther Exp $ */
2 /*
3 * Copyright (c) 1988, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <errno.h>
32 #include <limits.h>
33 #include <paths.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38
39 __warn_references(tempnam,
40 "warning: tempnam() possibly used unsafely; consider using mkstemp()");
41
42 char *
tempnam(const char * dir,const char * pfx)43 tempnam(const char *dir, const char *pfx)
44 {
45 int sverrno, len;
46 char *f, *name;
47
48 if (!(name = malloc(PATH_MAX)))
49 return(NULL);
50
51 if (!pfx)
52 pfx = "tmp.";
53
54 if (issetugid() == 0 && (f = getenv("TMPDIR")) && *f != '\0') {
55 len = snprintf(name, PATH_MAX, "%s%s%sXXXXXXXXXX", f,
56 f[strlen(f) - 1] == '/' ? "" : "/", pfx);
57 if (len < 0 || len >= PATH_MAX) {
58 errno = ENAMETOOLONG;
59 goto fail;
60 }
61 if ((f = _mktemp(name)))
62 return(f);
63 }
64
65 if (dir != NULL) {
66 f = *dir ? (char *)dir : ".";
67 len = snprintf(name, PATH_MAX, "%s%s%sXXXXXXXXXX", f,
68 f[strlen(f) - 1] == '/' ? "" : "/", pfx);
69 if (len < 0 || len >= PATH_MAX) {
70 errno = ENAMETOOLONG;
71 goto fail;
72 }
73 if ((f = _mktemp(name)))
74 return(f);
75 }
76
77 f = P_tmpdir;
78 len = snprintf(name, PATH_MAX, "%s%sXXXXXXXXX", f, pfx);
79 if (len < 0 || len >= PATH_MAX) {
80 errno = ENAMETOOLONG;
81 goto fail;
82 }
83 if ((f = _mktemp(name)))
84 return(f);
85
86 f = _PATH_TMP;
87 len = snprintf(name, PATH_MAX, "%s%sXXXXXXXXX", f, pfx);
88 if (len < 0 || len >= PATH_MAX) {
89 errno = ENAMETOOLONG;
90 goto fail;
91 }
92 if ((f = _mktemp(name)))
93 return(f);
94
95 fail:
96 sverrno = errno;
97 free(name);
98 errno = sverrno;
99 return(NULL);
100 }
101