xref: /illumos-gate/usr/src/lib/libresolv2/common/bsd/mktemp.c (revision 9b9d39d2a32ff806d2431dbcc50968ef1e6d46b2)
1 /*
2  * Copyright (c) 1987, 1993
3  *    The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  * 	This product includes software developed by the University of
16  * 	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
36  *
37  * Permission to use, copy, modify, and distribute this software for any
38  * purpose with or without fee is hereby granted, provided that the above
39  * copyright notice and this permission notice appear in all copies, and that
40  * the name of Digital Equipment Corporation not be used in advertising or
41  * publicity pertaining to distribution of the document or software without
42  * specific, written prior permission.
43  *
44  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
45  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
46  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
47  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
48  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
49  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
50  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
51  * SOFTWARE.
52  */
53 
54 #include "port_before.h"
55 
56 #include <sys/types.h>
57 #include <sys/stat.h>
58 
59 #include <ctype.h>
60 #include <errno.h>
61 #include <fcntl.h>
62 #include <stdio.h>
63 
64 #include "port_after.h"
65 
66 #if (!defined(NEED_MKTEMP)) && (!defined(NEED_MKSTEMP))
67 int __mktemp_unneeded__;
68 #else
69 
70 static int gettemp(char *path, int *doopen);
71 
72 #ifdef NEED_MKSTEMP
73 mkstemp(char *path) {
74 	int fd;
75 
76 	return (gettemp(path, &fd) ? fd : -1);
77 }
78 #endif
79 
80 #ifdef NEED_MKTEMP
81 char *
82 mktemp(char *path) {
83 	return(gettemp(path, (int *)NULL) ? path : (char *)NULL);
84 }
85 #endif
86 
87 static int
88 gettemp(char *path, int *doopen) {
89 	char *start, *trv;
90 	struct stat sbuf;
91 	u_int pid;
92 
93 	pid = getpid();
94 	for (trv = path; *trv; ++trv);		/*%< extra X's get set to 0's */
95 	while (*--trv == 'X') {
96 		*trv = (pid % 10) + '0';
97 		pid /= 10;
98 	}
99 
100 	/*
101 	 * check the target directory; if you have six X's and it
102 	 * doesn't exist this runs for a *very* long time.
103 	 */
104 	for (start = trv + 1;; --trv) {
105 		if (trv <= path)
106 			break;
107 		if (*trv == '/') {
108 			*trv = '\0';
109 			if (stat(path, &sbuf))
110 				return(0);
111 			if (!S_ISDIR(sbuf.st_mode)) {
112 				errno = ENOTDIR;
113 				return(0);
114 			}
115 			*trv = '/';
116 			break;
117 		}
118 	}
119 
120 	for (;;) {
121 		if (doopen) {
122 			if ((*doopen =
123 			    open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
124 				return(1);
125 			if (errno != EEXIST)
126 				return(0);
127 		}
128 		else if (stat(path, &sbuf))
129 			return(errno == ENOENT ? 1 : 0);
130 
131 		/* tricky little algorithm for backward compatibility */
132 		for (trv = start;;) {
133 			if (!*trv)
134 				return(0);
135 			if (*trv == 'z')
136 				*trv++ = 'a';
137 			else {
138 				if (isdigit(*trv))
139 					*trv = 'a';
140 				else
141 					++*trv;
142 				break;
143 			}
144 		}
145 	}
146 	/*NOTREACHED*/
147 }
148 
149 #endif /*NEED_MKTEMP*/
150 
151 /*! \file */
152