1 /*
2  * This is adapted from FreeBSD's src/bin/mkdir/mkdir.c, which bears
3  * the following copyright notice:
4  *
5  * Copyright (c) 1983, 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *	  notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *	  notice, this list of conditions and the following disclaimer in the
15  *	  documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  *	  may be used to endorse or promote products derived from this software
18  *	  without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "c.h"
34 
35 #include <sys/stat.h>
36 
37 
38 /*
39  * pg_mkdir_p --- create a directory and, if necessary, parent directories
40  *
41  * This is equivalent to "mkdir -p" except we don't complain if the target
42  * directory already exists.
43  *
44  * We assume the path is in canonical form, i.e., uses / as the separator.
45  *
46  * omode is the file permissions bits for the target directory.  Note that any
47  * parent directories that have to be created get permissions according to the
48  * prevailing umask, but with u+wx forced on to ensure we can create there.
49  * (We declare omode as int, not mode_t, to minimize dependencies for port.h.)
50  *
51  * Returns 0 on success, -1 (with errno set) on failure.
52  *
53  * Note that on failure, the path arg has been modified to show the particular
54  * directory level we had problems with.
55  */
56 int
pg_mkdir_p(char * path,int omode)57 pg_mkdir_p(char *path, int omode)
58 {
59 	struct stat sb;
60 	mode_t		numask,
61 				oumask;
62 	int			last,
63 				retval;
64 	char	   *p;
65 
66 	retval = 0;
67 	p = path;
68 
69 #ifdef WIN32
70 	/* skip network and drive specifiers for win32 */
71 	if (strlen(p) >= 2)
72 	{
73 		if (p[0] == '/' && p[1] == '/')
74 		{
75 			/* network drive */
76 			p = strstr(p + 2, "/");
77 			if (p == NULL)
78 			{
79 				errno = EINVAL;
80 				return -1;
81 			}
82 		}
83 		else if (p[1] == ':' &&
84 				 ((p[0] >= 'a' && p[0] <= 'z') ||
85 				  (p[0] >= 'A' && p[0] <= 'Z')))
86 		{
87 			/* local drive */
88 			p += 2;
89 		}
90 	}
91 #endif
92 
93 	/*
94 	 * POSIX 1003.2: For each dir operand that does not name an existing
95 	 * directory, effects equivalent to those caused by the following command
96 	 * shall occur:
97 	 *
98 	 * mkdir -p -m $(umask -S),u+wx $(dirname dir) && mkdir [-m mode] dir
99 	 *
100 	 * We change the user's umask and then restore it, instead of doing
101 	 * chmod's.  Note we assume umask() can't change errno.
102 	 */
103 	oumask = umask(0);
104 	numask = oumask & ~(S_IWUSR | S_IXUSR);
105 	(void) umask(numask);
106 
107 	if (p[0] == '/')			/* Skip leading '/'. */
108 		++p;
109 	for (last = 0; !last; ++p)
110 	{
111 		if (p[0] == '\0')
112 			last = 1;
113 		else if (p[0] != '/')
114 			continue;
115 		*p = '\0';
116 		if (!last && p[1] == '\0')
117 			last = 1;
118 
119 		if (last)
120 			(void) umask(oumask);
121 
122 		/* check for pre-existing directory */
123 		if (stat(path, &sb) == 0)
124 		{
125 			if (!S_ISDIR(sb.st_mode))
126 			{
127 				if (last)
128 					errno = EEXIST;
129 				else
130 					errno = ENOTDIR;
131 				retval = -1;
132 				break;
133 			}
134 		}
135 		else if (mkdir(path, last ? omode : S_IRWXU | S_IRWXG | S_IRWXO) < 0)
136 		{
137 			retval = -1;
138 			break;
139 		}
140 		if (!last)
141 			*p = '/';
142 	}
143 
144 	/* ensure we restored umask */
145 	(void) umask(oumask);
146 
147 	return retval;
148 }
149