1 /* Temporary file handling for tests.
2 Copyright (C) 1998-2022 Free Software Foundation, Inc.
3 Copyright The GNU Tools Authors.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20 /* This is required to get an mkstemp which can create large files on
21 some 32-bit platforms. */
22 #define _FILE_OFFSET_BITS 64
23
24 #include <support/check.h>
25 #include <support/temp_file.h>
26 #include <support/temp_file-internal.h>
27 #include <support/support.h>
28
29 #include <errno.h>
30 #include <paths.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <xunistd.h>
35
36 /* List of temporary files. */
37 static struct temp_name_list
38 {
39 struct temp_name_list *next;
40 char *name;
41 pid_t owner;
42 bool toolong;
43 } *temp_name_list;
44
45 /* Location of the temporary files. Set by the test skeleton via
46 support_set_test_dir. The string is not be freed. */
47 static const char *test_dir = _PATH_TMP;
48
49 /* Name of subdirectories in a too long temporary directory tree. */
50 static char toolong_subdir[NAME_MAX + 1];
51 static bool toolong_initialized;
52 static size_t toolong_path_max;
53
54 static void
add_temp_file_internal(const char * name,bool toolong)55 add_temp_file_internal (const char *name, bool toolong)
56 {
57 struct temp_name_list *newp
58 = (struct temp_name_list *) xcalloc (sizeof (*newp), 1);
59 char *newname = strdup (name);
60 if (newname != NULL)
61 {
62 newp->name = newname;
63 newp->next = temp_name_list;
64 newp->owner = getpid ();
65 newp->toolong = toolong;
66 temp_name_list = newp;
67 }
68 else
69 free (newp);
70 }
71
72 void
add_temp_file(const char * name)73 add_temp_file (const char *name)
74 {
75 add_temp_file_internal (name, false);
76 }
77
78 int
create_temp_file_in_dir(const char * base,const char * dir,char ** filename)79 create_temp_file_in_dir (const char *base, const char *dir, char **filename)
80 {
81 char *fname;
82 int fd;
83
84 fname = xasprintf ("%s/%sXXXXXX", dir, base);
85
86 fd = mkstemp (fname);
87 if (fd == -1)
88 {
89 printf ("cannot open temporary file '%s': %m\n", fname);
90 free (fname);
91 return -1;
92 }
93
94 add_temp_file (fname);
95 if (filename != NULL)
96 *filename = fname;
97 else
98 free (fname);
99
100 return fd;
101 }
102
103 int
create_temp_file(const char * base,char ** filename)104 create_temp_file (const char *base, char **filename)
105 {
106 return create_temp_file_in_dir (base, test_dir, filename);
107 }
108
109 static char *
create_temp_directory_internal(const char * base,bool toolong)110 create_temp_directory_internal (const char *base, bool toolong)
111 {
112 char *path = xasprintf ("%s/%sXXXXXX", test_dir, base);
113 if (mkdtemp (path) == NULL)
114 {
115 printf ("error: mkdtemp (\"%s\"): %m", path);
116 exit (1);
117 }
118 add_temp_file_internal (path, toolong);
119 return path;
120 }
121
122 char *
support_create_temp_directory(const char * base)123 support_create_temp_directory (const char *base)
124 {
125 return create_temp_directory_internal (base, false);
126 }
127
128 static void
ensure_toolong_initialized(void)129 ensure_toolong_initialized (void)
130 {
131 if (!toolong_initialized)
132 FAIL_EXIT1 ("uninitialized toolong directory tree\n");
133 }
134
135 static void
initialize_toolong(const char * base)136 initialize_toolong (const char *base)
137 {
138 long name_max = pathconf (base, _PC_NAME_MAX);
139 name_max = (name_max < 0 ? 64
140 : (name_max < sizeof (toolong_subdir) ? name_max
141 : sizeof (toolong_subdir) - 1));
142
143 long path_max = pathconf (base, _PC_PATH_MAX);
144 path_max = (path_max < 0 ? 1024
145 : path_max <= PTRDIFF_MAX ? path_max : PTRDIFF_MAX);
146
147 /* Sanity check to ensure that the test does not create temporary directories
148 in different filesystems because this API doesn't support it. */
149 if (toolong_initialized)
150 {
151 if (name_max != strlen (toolong_subdir))
152 FAIL_UNSUPPORTED ("name_max: Temporary directories in different"
153 " filesystems not supported yet\n");
154 if (path_max != toolong_path_max)
155 FAIL_UNSUPPORTED ("path_max: Temporary directories in different"
156 " filesystems not supported yet\n");
157 return;
158 }
159
160 toolong_path_max = path_max;
161
162 size_t len = name_max;
163 memset (toolong_subdir, 'X', len);
164 toolong_initialized = true;
165 }
166
167 char *
support_create_and_chdir_toolong_temp_directory(const char * basename)168 support_create_and_chdir_toolong_temp_directory (const char *basename)
169 {
170 char *base = create_temp_directory_internal (basename, true);
171 xchdir (base);
172
173 initialize_toolong (base);
174
175 size_t sz = strlen (toolong_subdir);
176
177 /* Create directories and descend into them so that the final path is larger
178 than PATH_MAX. */
179 for (size_t i = 0; i <= toolong_path_max / sz; i++)
180 {
181 int ret = mkdir (toolong_subdir, S_IRWXU);
182 if (ret != 0 && errno == ENAMETOOLONG)
183 FAIL_UNSUPPORTED ("Filesystem does not support creating too long "
184 "directory trees\n");
185 else if (ret != 0)
186 FAIL_EXIT1 ("Failed to create directory tree: %m\n");
187 xchdir (toolong_subdir);
188 }
189 return base;
190 }
191
192 void
support_chdir_toolong_temp_directory(const char * base)193 support_chdir_toolong_temp_directory (const char *base)
194 {
195 ensure_toolong_initialized ();
196
197 xchdir (base);
198
199 size_t sz = strlen (toolong_subdir);
200 for (size_t i = 0; i <= toolong_path_max / sz; i++)
201 xchdir (toolong_subdir);
202 }
203
204 /* Helper functions called by the test skeleton follow. */
205
206 static void
remove_toolong_subdirs(const char * base)207 remove_toolong_subdirs (const char *base)
208 {
209 ensure_toolong_initialized ();
210
211 if (chdir (base) != 0)
212 {
213 printf ("warning: toolong cleanup base failed: chdir (\"%s\"): %m\n",
214 base);
215 return;
216 }
217
218 /* Descend. */
219 int levels = 0;
220 size_t sz = strlen (toolong_subdir);
221 for (levels = 0; levels <= toolong_path_max / sz; levels++)
222 if (chdir (toolong_subdir) != 0)
223 {
224 printf ("warning: toolong cleanup failed: chdir (\"%s\"): %m\n",
225 toolong_subdir);
226 break;
227 }
228
229 /* Ascend and remove. */
230 while (--levels >= 0)
231 {
232 if (chdir ("..") != 0)
233 {
234 printf ("warning: toolong cleanup failed: chdir (\"..\"): %m\n");
235 return;
236 }
237 if (remove (toolong_subdir) != 0)
238 {
239 printf ("warning: could not remove subdirectory: %s: %m\n",
240 toolong_subdir);
241 return;
242 }
243 }
244 }
245
246 void
support_delete_temp_files(void)247 support_delete_temp_files (void)
248 {
249 pid_t pid = getpid ();
250 while (temp_name_list != NULL)
251 {
252 /* Only perform the removal if the path was registed in the same
253 process, as identified by the PID. (This assumes that the
254 parent process which registered the temporary file sticks
255 around, to prevent PID reuse.) */
256 if (temp_name_list->owner == pid)
257 {
258 if (temp_name_list->toolong)
259 remove_toolong_subdirs (temp_name_list->name);
260
261 if (remove (temp_name_list->name) != 0)
262 printf ("warning: could not remove temporary file: %s: %m\n",
263 temp_name_list->name);
264 }
265 free (temp_name_list->name);
266
267 struct temp_name_list *next = temp_name_list->next;
268 free (temp_name_list);
269 temp_name_list = next;
270 }
271 }
272
273 void
support_print_temp_files(FILE * f)274 support_print_temp_files (FILE *f)
275 {
276 if (temp_name_list != NULL)
277 {
278 struct temp_name_list *n;
279 fprintf (f, "temp_files=(\n");
280 for (n = temp_name_list; n != NULL; n = n->next)
281 fprintf (f, " '%s'\n", n->name);
282 fprintf (f, ")\n");
283 }
284 }
285
286 void
support_set_test_dir(const char * path)287 support_set_test_dir (const char *path)
288 {
289 test_dir = path;
290 }
291