1 /*-------------------------------------------------------------------------
2  *
3  * mkdtemp.c
4  *	  create a mode-0700 temporary directory
5  *
6  * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
7  *
8  *
9  * IDENTIFICATION
10  *	  src/port/mkdtemp.c
11  *
12  * This code was taken from NetBSD to provide an implementation for platforms
13  * that lack it.  (Among compatibly-licensed implementations, the OpenBSD
14  * version better resists denial-of-service attacks.  However, it has a
15  * cryptographic dependency.)  The NetBSD copyright terms follow.
16  *-------------------------------------------------------------------------
17  */
18 
19 #include "c.h"
20 
21 #define _DIAGASSERT(x) do {} while (0)
22 
23 
24 /*	$NetBSD: gettemp.c,v 1.17 2014/01/21 19:09:48 seanb Exp $	*/
25 
26 /*
27  * Copyright (c) 1987, 1993
28  *	The Regents of the University of California.  All rights reserved.
29  *
30  * Redistribution and use in source and binary forms, with or without
31  * modification, are permitted provided that the following conditions
32  * are met:
33  * 1. Redistributions of source code must retain the above copyright
34  *	  notice, this list of conditions and the following disclaimer.
35  * 2. Redistributions in binary form must reproduce the above copyright
36  *	  notice, this list of conditions and the following disclaimer in the
37  *	  documentation and/or other materials provided with the distribution.
38  * 3. Neither the name of the University nor the names of its contributors
39  *	  may be used to endorse or promote products derived from this software
40  *	  without specific prior written permission.
41  *
42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52  * SUCH DAMAGE.
53  */
54 
55 #if HAVE_NBTOOL_CONFIG_H
56 #include "nbtool_config.h"
57 #endif
58 
59 #if !HAVE_NBTOOL_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP
60 
61 #ifdef NOT_POSTGRESQL
62 #include <sys/cdefs.h>
63 #if defined(LIBC_SCCS) && !defined(lint)
64 #if 0
65 static char sccsid[] = "@(#)mktemp.c	8.1 (Berkeley) 6/4/93";
66 #else
67 __RCSID("$NetBSD: gettemp.c,v 1.17 2014/01/21 19:09:48 seanb Exp $");
68 #endif
69 #endif							/* LIBC_SCCS and not lint */
70 #endif
71 
72 #include <sys/types.h>
73 #include <sys/stat.h>
74 
75 #include <assert.h>
76 #include <ctype.h>
77 #include <errno.h>
78 #include <fcntl.h>
79 #include <stdio.h>
80 #include <stdlib.h>
81 #include <unistd.h>
82 
83 #ifdef NOT_POSTGRESQL
84 #if HAVE_NBTOOL_CONFIG_H
85 #define GETTEMP		__nbcompat_gettemp
86 #else
87 #include "reentrant.h"
88 #include "local.h"
89 #define GETTEMP		__gettemp
90 #endif
91 #endif
92 
93 static int
GETTEMP(char * path,int * doopen,int domkdir)94 GETTEMP(char *path, int *doopen, int domkdir)
95 {
96 	char	   *start,
97 			   *trv;
98 	struct stat sbuf;
99 	u_int		pid;
100 
101 	/*
102 	 * To guarantee multiple calls generate unique names even if the file is
103 	 * not created. 676 different possibilities with 7 or more X's, 26 with 6
104 	 * or less.
105 	 */
106 	static char xtra[2] = "aa";
107 	int			xcnt = 0;
108 
109 	_DIAGASSERT(path != NULL);
110 	/* doopen may be NULL */
111 
112 	pid = getpid();
113 
114 	/* Move to end of path and count trailing X's. */
115 	for (trv = path; *trv; ++trv)
116 		if (*trv == 'X')
117 			xcnt++;
118 		else
119 			xcnt = 0;
120 
121 	/* Use at least one from xtra.  Use 2 if more than 6 X's. */
122 	if (xcnt > 0)
123 	{
124 		*--trv = xtra[0];
125 		xcnt--;
126 	}
127 	if (xcnt > 5)
128 	{
129 		*--trv = xtra[1];
130 		xcnt--;
131 	}
132 
133 	/* Set remaining X's to pid digits with 0's to the left. */
134 	for (; xcnt > 0; xcnt--)
135 	{
136 		*--trv = (pid % 10) + '0';
137 		pid /= 10;
138 	}
139 
140 	/* update xtra for next call. */
141 	if (xtra[0] != 'z')
142 		xtra[0]++;
143 	else
144 	{
145 		xtra[0] = 'a';
146 		if (xtra[1] != 'z')
147 			xtra[1]++;
148 		else
149 			xtra[1] = 'a';
150 	}
151 
152 	/*
153 	 * check the target directory; if you have six X's and it doesn't exist
154 	 * this runs for a *very* long time.
155 	 */
156 	for (start = trv + 1;; --trv)
157 	{
158 		if (trv <= path)
159 			break;
160 		if (*trv == '/')
161 		{
162 			int			e;
163 
164 			*trv = '\0';
165 			e = stat(path, &sbuf);
166 			*trv = '/';
167 			if (e == -1)
168 				return doopen == NULL && !domkdir;
169 			if (!S_ISDIR(sbuf.st_mode))
170 			{
171 				errno = ENOTDIR;
172 				return doopen == NULL && !domkdir;
173 			}
174 			break;
175 		}
176 	}
177 
178 	for (;;)
179 	{
180 		if (doopen)
181 		{
182 			if ((*doopen =
183 				 open(path, O_CREAT | O_EXCL | O_RDWR, 0600)) >= 0)
184 				return 1;
185 			if (errno != EEXIST)
186 				return 0;
187 		}
188 		else if (domkdir)
189 		{
190 			if (mkdir(path, 0700) >= 0)
191 				return 1;
192 			if (errno != EEXIST)
193 				return 0;
194 		}
195 		else if (lstat(path, &sbuf))
196 			return errno == ENOENT ? 1 : 0;
197 
198 		/* tricky little algorithm for backward compatibility */
199 		for (trv = start;;)
200 		{
201 			if (!*trv)
202 				return 0;
203 			if (*trv == 'z')
204 				*trv++ = 'a';
205 			else
206 			{
207 				if (isdigit((unsigned char) *trv))
208 					*trv = 'a';
209 				else
210 					++*trv;
211 				break;
212 			}
213 		}
214 	}
215 	/* NOTREACHED */
216 }
217 
218 #endif							/* !HAVE_NBTOOL_CONFIG_H || !HAVE_MKSTEMP ||
219 								 * !HAVE_MKDTEMP */
220 
221 
222 /*	$NetBSD: mkdtemp.c,v 1.11 2012/03/15 18:22:30 christos Exp $	*/
223 
224 /*
225  * Copyright (c) 1987, 1993
226  *	The Regents of the University of California.  All rights reserved.
227  *
228  * Redistribution and use in source and binary forms, with or without
229  * modification, are permitted provided that the following conditions
230  * are met:
231  * 1. Redistributions of source code must retain the above copyright
232  *	  notice, this list of conditions and the following disclaimer.
233  * 2. Redistributions in binary form must reproduce the above copyright
234  *	  notice, this list of conditions and the following disclaimer in the
235  *	  documentation and/or other materials provided with the distribution.
236  * 3. Neither the name of the University nor the names of its contributors
237  *	  may be used to endorse or promote products derived from this software
238  *	  without specific prior written permission.
239  *
240  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
241  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
242  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
243  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
244  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
245  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
246  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
247  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
248  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
249  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
250  * SUCH DAMAGE.
251  */
252 
253 #if HAVE_NBTOOL_CONFIG_H
254 #include "nbtool_config.h"
255 #endif
256 
257 #if !HAVE_NBTOOL_CONFIG_H || !HAVE_MKDTEMP
258 
259 #ifdef NOT_POSTGRESQL
260 
261 #include <sys/cdefs.h>
262 #if defined(LIBC_SCCS) && !defined(lint)
263 #if 0
264 static char sccsid[] = "@(#)mktemp.c	8.1 (Berkeley) 6/4/93";
265 #else
266 __RCSID("$NetBSD: mkdtemp.c,v 1.11 2012/03/15 18:22:30 christos Exp $");
267 #endif
268 #endif							/* LIBC_SCCS and not lint */
269 
270 #if HAVE_NBTOOL_CONFIG_H
271 #define GETTEMP		__nbcompat_gettemp
272 #else
273 #include <assert.h>
274 #include <errno.h>
275 #include <stdio.h>
276 #include <stdlib.h>
277 #include <unistd.h>
278 #include "reentrant.h"
279 #include "local.h"
280 #define GETTEMP		__gettemp
281 #endif
282 
283 #endif
284 
285 char *
mkdtemp(char * path)286 mkdtemp(char *path)
287 {
288 	_DIAGASSERT(path != NULL);
289 
290 	return GETTEMP(path, NULL, 1) ? path : NULL;
291 }
292 
293 #endif							/* !HAVE_NBTOOL_CONFIG_H || !HAVE_MKDTEMP */
294