1 /* Copyright (C) 1999, 2001-2002, 2006 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
7 any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
17
18 /* Extracted from sysdeps/posix/tempname.c. */
19
20 #include <config.h>
21
22 /* Specification. */
23 #include "tmpdir.h"
24
25 #include <stdbool.h>
26 #include <stdlib.h>
27 #include <string.h>
28
29 #include <errno.h>
30 #ifndef __set_errno
31 # define __set_errno(Val) errno = (Val)
32 #endif
33
34 #include <stdio.h>
35 #ifndef P_tmpdir
36 # define P_tmpdir "/tmp"
37 #endif
38
39 #include <sys/stat.h>
40 #if !defined S_ISDIR && defined S_IFDIR
41 # define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
42 #endif
43 #if !S_IRUSR && S_IREAD
44 # define S_IRUSR S_IREAD
45 #endif
46 #if !S_IRUSR
47 # define S_IRUSR 00400
48 #endif
49 #if !S_IWUSR && S_IWRITE
50 # define S_IWUSR S_IWRITE
51 #endif
52 #if !S_IWUSR
53 # define S_IWUSR 00200
54 #endif
55 #if !S_IXUSR && S_IEXEC
56 # define S_IXUSR S_IEXEC
57 #endif
58 #if !S_IXUSR
59 # define S_IXUSR 00100
60 #endif
61
62 #if _LIBC
63 # define struct_stat64 struct stat64
64 #else
65 # define struct_stat64 struct stat
66 # define __xstat64(version, path, buf) stat (path, buf)
67 #endif
68
69 #if ! (HAVE___SECURE_GETENV || _LIBC)
70 # define __secure_getenv getenv
71 #endif
72
73 /* Pathname support.
74 ISSLASH(C) tests whether C is a directory separator character.
75 */
76 #if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__
77 /* Win32, Cygwin, OS/2, DOS */
78 # define ISSLASH(C) ((C) == '/' || (C) == '\\')
79 #else
80 /* Unix */
81 # define ISSLASH(C) ((C) == '/')
82 #endif
83
84
85 /* Return nonzero if DIR is an existent directory. */
86 static bool
direxists(const char * dir)87 direxists (const char *dir)
88 {
89 struct_stat64 buf;
90 return __xstat64 (_STAT_VER, dir, &buf) == 0 && S_ISDIR (buf.st_mode);
91 }
92
93 /* Path search algorithm, for tmpnam, tmpfile, etc. If DIR is
94 non-null and exists, uses it; otherwise uses the first of $TMPDIR,
95 P_tmpdir, /tmp that exists. Copies into TMPL a template suitable
96 for use with mk[s]temp. Will fail (-1) if DIR is non-null and
97 doesn't exist, none of the searched dirs exists, or there's not
98 enough space in TMPL. */
99 int
path_search(char * tmpl,size_t tmpl_len,const char * dir,const char * pfx,bool try_tmpdir)100 path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
101 bool try_tmpdir)
102 {
103 const char *d;
104 size_t dlen, plen;
105
106 if (!pfx || !pfx[0])
107 {
108 pfx = "file";
109 plen = 4;
110 }
111 else
112 {
113 plen = strlen (pfx);
114 if (plen > 5)
115 plen = 5;
116 }
117
118 if (try_tmpdir)
119 {
120 d = __secure_getenv ("TMPDIR");
121 if (d != NULL && direxists (d))
122 dir = d;
123 else if (dir != NULL && direxists (dir))
124 /* nothing */ ;
125 else
126 dir = NULL;
127 }
128 if (dir == NULL)
129 {
130 if (direxists (P_tmpdir))
131 dir = P_tmpdir;
132 else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
133 dir = "/tmp";
134 else
135 {
136 __set_errno (ENOENT);
137 return -1;
138 }
139 }
140
141 dlen = strlen (dir);
142 while (dlen >= 1 && ISSLASH (dir[dlen - 1]))
143 dlen--; /* remove trailing slashes */
144
145 /* check we have room for "${dir}/${pfx}XXXXXX\0" */
146 if (tmpl_len < dlen + 1 + plen + 6 + 1)
147 {
148 __set_errno (EINVAL);
149 return -1;
150 }
151
152 sprintf (tmpl, "%.*s/%.*sXXXXXX", (int) dlen, dir, (int) plen, pfx);
153 return 0;
154 }
155