1 /* $OpenBSD: tempnam.c,v 1.17 2013/09/30 12:02:35 millert 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 extern char *_mktemp(char *);
43
44 char *
tempnam(const char * dir,const char * pfx)45 tempnam(const char *dir, const char *pfx)
46 {
47 int sverrno, len;
48 char *f, *name;
49
50 if (!(name = malloc(PATH_MAX)))
51 return(NULL);
52
53 if (!pfx)
54 pfx = "tmp.";
55
56 if (issetugid() == 0 && (f = getenv("TMPDIR")) && *f != '\0') {
57 len = snprintf(name, PATH_MAX, "%s%s%sXXXXXXXXXX", f,
58 f[strlen(f) - 1] == '/' ? "" : "/", pfx);
59 if (len < 0 || len >= PATH_MAX) {
60 errno = ENAMETOOLONG;
61 return(NULL);
62 }
63 if ((f = _mktemp(name)))
64 return(f);
65 }
66
67 if (dir != NULL) {
68 f = *dir ? (char *)dir : ".";
69 len = snprintf(name, PATH_MAX, "%s%s%sXXXXXXXXXX", f,
70 f[strlen(f) - 1] == '/' ? "" : "/", pfx);
71 if (len < 0 || len >= PATH_MAX) {
72 errno = ENAMETOOLONG;
73 return(NULL);
74 }
75 if ((f = _mktemp(name)))
76 return(f);
77 }
78
79 f = P_tmpdir;
80 len = snprintf(name, PATH_MAX, "%s%sXXXXXXXXX", f, pfx);
81 if (len < 0 || len >= PATH_MAX) {
82 errno = ENAMETOOLONG;
83 return(NULL);
84 }
85 if ((f = _mktemp(name)))
86 return(f);
87
88 f = _PATH_TMP;
89 len = snprintf(name, PATH_MAX, "%s%sXXXXXXXXX", f, pfx);
90 if (len < 0 || len >= PATH_MAX) {
91 errno = ENAMETOOLONG;
92 return(NULL);
93 }
94 if ((f = _mktemp(name)))
95 return(f);
96
97 sverrno = errno;
98 free(name);
99 errno = sverrno;
100 return(NULL);
101 }
102