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mkdtemp.c
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1 /*-------------------------------------------------------------------------
2  *
3  * mkdtemp.c
4  * create a mode-0700 temporary directory
5  *
6  * Portions Copyright (c) 1996-2017, 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
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 *
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 */
#define _DIAGASSERT(x)
Definition: mkdtemp.c:21
#define mkdir(a, b)
Definition: win32.h:57
char * mkdtemp(char *path)
Definition: mkdtemp.c:286
static int GETTEMP(char *path, int *doopen, int domkdir)
Definition: mkdtemp.c:94
e
Definition: preproc-init.c:82
#define lstat(path, sb)
Definition: win32.h:262