xref: /illumos-gate/usr/src/lib/libc/port/gen/mkstemp.c (revision e4d060fb4c00d44cd578713eb9a921f594b733b8)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T
29  * All Rights Reserved
30  *
31  * Portions of this source code were derived from Berkeley
32  * 4.3 BSD under license from the regents of the University of
33  * California.
34  */
35 
36 #pragma ident	"%Z%%M%	%I%	%E% SMI"
37 
38 #include <sys/feature_tests.h>
39 
40 #if !defined(_LP64) && _FILE_OFFSET_BITS == 64
41 #define	mkstemp		mkstemp64
42 #define	mkstemps	mkstemps64
43 #define	libc_mkstemps	libc_mkstemps64		/* prefer unique statics */
44 #pragma weak _mkstemp64 = mkstemp64
45 #else
46 #pragma weak _mkstemp = mkstemp
47 #endif
48 
49 #include "lint.h"
50 #include <sys/fcntl.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <errno.h>
54 #include <alloca.h>
55 #include <sys/types.h>
56 #include <sys/stat.h>
57 #include <fcntl.h>
58 
59 extern char *libc_mktemps(char *, int);
60 
61 static int
62 libc_mkstemps(char *as, int slen)
63 {
64 	int	fd;
65 	int	len;
66 	char	*tstr, *str, *mkret;
67 
68 	if (as == NULL || *as == NULL)
69 		return (-1);
70 
71 	len = (int)strlen(as);
72 	tstr = alloca(len + 1);
73 	(void) strcpy(tstr, as);
74 
75 	if (slen < 0 || slen >= len)
76 		return (-1);
77 
78 	str = tstr + (len - 1 - slen);
79 
80 	/*
81 	 * The following for() loop is doing work.  mktemp() will generate
82 	 * a different name each time through the loop.  So if the first
83 	 * name is used then keep trying until you find a free filename.
84 	 */
85 
86 	for (;;) {
87 		if (*str == 'X') { /* If no trailing X's don't call mktemp. */
88 			mkret = libc_mktemps(as, slen);
89 			if (*mkret == '\0') {
90 				return (-1);
91 			}
92 		}
93 #if _FILE_OFFSET_BITS == 64
94 		if ((fd = open64(as, O_CREAT|O_EXCL|O_RDWR, 0600)) != -1) {
95 			return (fd);
96 		}
97 #else
98 		if ((fd = open(as, O_CREAT|O_EXCL|O_RDWR, 0600)) != -1) {
99 			return (fd);
100 		}
101 #endif  /* _FILE_OFFSET_BITS == 64 */
102 
103 		/*
104 		 * If the error condition is other than EEXIST or if the
105 		 * file exists and there are no X's in the string
106 		 * return -1.
107 		 */
108 
109 		if ((errno != EEXIST) || (*str != 'X')) {
110 			return (-1);
111 		}
112 		(void) strcpy(as, tstr);
113 	}
114 }
115 
116 int
117 mkstemp(char *as)
118 {
119 	return (libc_mkstemps(as, 0));
120 }
121 
122 int
123 mkstemps(char *as, int slen)
124 {
125 	return (libc_mkstemps(as, slen));
126 }
127