xref: /PHP-7.2/ext/zip/lib/mkstemp.c (revision bd7fafb6)
1 /* Adapted from NetBSB libc by Dieter Baron */
2 
3 /*	NetBSD: gettemp.c,v 1.13 2003/12/05 00:57:36 uebayasi Exp 	*/
4 
5 /*
6  * Copyright (c) 1987, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. 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 #include <sys/types.h>
35 #include <sys/stat.h>
36 
37 #include <assert.h>
38 #include <ctype.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #ifdef _WIN32
42 #include <io.h>
43 #endif
44 #include <stdio.h>
45 #include <stdlib.h>
46 #ifndef _WIN32
47 #include <unistd.h>
48 #endif
49 
50 #ifndef O_BINARY
51 #define O_BINARY 0
52 #endif
53 
54 
55 int
_zip_mkstemp(char * path)56 _zip_mkstemp(char *path)
57 {
58 #ifdef _WIN32
59 	int ret;
60 	ret = _creat(_mktemp(path), _S_IREAD|_S_IWRITE);
61 	if (ret == -1) {
62 		return 0;
63 	} else {
64 		return ret;
65 	}
66 #else
67 	int fd;
68 	char *start, *trv;
69 	struct stat sbuf;
70 	pid_t pid;
71 
72 	/* To guarantee multiple calls generate unique names even if
73 	   the file is not created. 676 different possibilities with 7
74 	   or more X's, 26 with 6 or less. */
75 	static char xtra[2] = "aa";
76 	int xcnt = 0;
77 
78 	pid = getpid();
79 
80 	/* Move to end of path and count trailing X's. */
81 	for (trv = path; *trv; ++trv)
82 		if (*trv == 'X')
83 			xcnt++;
84 		else
85 			xcnt = 0;
86 
87 	/* Use at least one from xtra.  Use 2 if more than 6 X's. */
88 	if (*(trv - 1) == 'X')
89 		*--trv = xtra[0];
90 	if (xcnt > 6 && *(trv - 1) == 'X')
91 		*--trv = xtra[1];
92 
93 	/* Set remaining X's to pid digits with 0's to the left. */
94 	while (*--trv == 'X') {
95 		*trv = (pid % 10) + '0';
96 		pid /= 10;
97 	}
98 
99 	/* update xtra for next call. */
100 	if (xtra[0] != 'z')
101 		xtra[0]++;
102 	else {
103 		xtra[0] = 'a';
104 		if (xtra[1] != 'z')
105 			xtra[1]++;
106 		else
107 			xtra[1] = 'a';
108 	}
109 
110 	/*
111 	 * check the target directory; if you have six X's and it
112 	 * doesn't exist this runs for a *very* long time.
113 	 */
114 	for (start = trv + 1;; --trv) {
115 		if (trv <= path)
116 			break;
117 		if (*trv == '/') {
118 			*trv = '\0';
119 			if (stat(path, &sbuf))
120 				return (0);
121 			if (!S_ISDIR(sbuf.st_mode)) {
122 				errno = ENOTDIR;
123 				return (0);
124 			}
125 			*trv = '/';
126 			break;
127 		}
128 	}
129 
130 	for (;;) {
131 		if ((fd=open(path, O_CREAT|O_EXCL|O_RDWR|O_BINARY, 0600)) >= 0)
132 			return (fd);
133 		if (errno != EEXIST)
134 			return (0);
135 
136 		/* tricky little algorithm for backward compatibility */
137 		for (trv = start;;) {
138 			if (!*trv)
139 				return (0);
140 			if (*trv == 'z')
141 				*trv++ = 'a';
142 			else {
143 				if (isdigit((unsigned char)*trv))
144 					*trv = 'a';
145 				else
146 					++*trv;
147 				break;
148 			}
149 		}
150 	}
151 	/*NOTREACHED*/
152 #endif
153 }
154