xref: /minix/minix/tests/test43.c (revision 83133719)
1 /* Tests for MINIX3 realpath(3) - by Erik van der Kouwe */
2 #include <assert.h>
3 #include <dirent.h>
4 #include <errno.h>
5 #include <libgen.h>
6 #include <limits.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <sys/stat.h>
11 #include <unistd.h>
12 
13 int max_error = 3;
14 #include "common.h"
15 
16 
17 int subtest;
18 static const char *executable;
19 
20 
21 #define ERR (e(__LINE__))
22 
23 static char *remove_last_path_component(char *path)
24 {
25 	char *current, *last;
26 
27 	assert(path);
28 
29 	/* find last slash */
30 	last = NULL;
31 	for (current = path; *current; current++)
32 		if (*current == '/')
33 			last = current;
34 
35 	/* check path component */
36 	if (last)
37 	{
38 		if (strcmp(last + 1, ".") == 0) ERR;
39 		if (strcmp(last + 1, "..") == 0) ERR;
40 	}
41 
42 	/* if only root path slash, we are done */
43 	if (last <= path)
44 		return NULL;
45 
46 	/* chop off last path component */
47 	*last = 0;
48 	return path;
49 }
50 
51 static int check_path_components(const char *path)
52 {
53 	char buffer[PATH_MAX + 1], *bufferpos;
54 	struct stat statbuf;
55 
56 	assert(strlen(path) < sizeof(buffer));
57 
58 	bufferpos = buffer;
59 	while (*path)
60 	{
61 		/* copy next path segment */
62 		do
63 		{
64 			*(bufferpos++) = *(path++);
65 		} while (*path && *path != '/');
66 		*bufferpos = 0;
67 
68 		/*
69 		 * is this a valid path segment? if not, return errno.
70 		 * one exception: the last path component need not exist
71 		 * - unless it is actually a dangling symlink
72 		 */
73 		if (stat(buffer, &statbuf) < 0 &&
74 			(*path || errno != ENOENT ||
75 			lstat(buffer, &statbuf) == 0))
76 			return errno;
77 	}
78 
79 	return 0;
80 }
81 
82 static void check_realpath(const char *path, int expected_errno)
83 {
84 	char buffer[PATH_MAX + 1], *resolved_path;
85 	int expected_errno2;
86 	struct stat statbuf[2];
87 
88 	assert(path);
89 
90 	/* any errors in the path that realpath should report? */
91 	expected_errno2 = check_path_components(path);
92 
93 	/* run realpath */
94 	errno = 0;
95 	resolved_path = realpath(path, buffer);
96 
97 	/* do we get errors when expected? */
98 	if (expected_errno || expected_errno2)
99 	{
100 		if (resolved_path) ERR;
101 		if (errno != expected_errno && errno != expected_errno2) ERR;
102 		return;
103 	}
104 
105 	/* do we get success when expected? */
106 	if (!resolved_path)
107 	{
108 		ERR;
109 		return;
110 	}
111 	errno = 0;
112 
113 	/* do the paths point to the same file? (only check if exists) */
114 	if (stat(path,          &statbuf[0]) < 0)
115 	{
116 		if (errno != ENOENT) { ERR; return; }
117 	}
118 	else
119 	{
120 		if (stat(resolved_path, &statbuf[1]) < 0) { ERR; return; }
121 		if (statbuf[0].st_dev != statbuf[1].st_dev) ERR;
122 		if (statbuf[0].st_ino != statbuf[1].st_ino) ERR;
123 	}
124 
125 	/* is the path absolute? */
126 	if (resolved_path[0] != '/') ERR;
127 
128 	/* is each path element allowable? */
129 	while (remove_last_path_component(resolved_path))
130 	{
131 		/* not a symlink? */
132 		if (lstat(resolved_path, &statbuf[1]) < 0) { ERR; return; }
133 		if ((statbuf[1].st_mode & S_IFMT) != S_IFDIR) ERR;
134 	}
135 }
136 
137 static void check_realpath_step_by_step(const char *path, int expected_errno)
138 {
139 	char buffer[PATH_MAX + 1];
140 	const char *path_current;
141 
142 	assert(path);
143 	assert(strlen(path) < sizeof(buffer));
144 
145 	/* check the absolute path */
146 	check_realpath(path, expected_errno);
147 
148 	/* try with different CWDs */
149 	for (path_current = path; *path_current; path_current++)
150 		if (path_current[0] == '/' && path_current[1])
151 		{
152 			/* set CWD */
153 			memcpy(buffer, path, path_current - path + 1);
154 			buffer[path_current - path + 1] = 0;
155 			if (chdir(buffer) < 0) { ERR; continue; }
156 
157 			/* perform test */
158 			check_realpath(path_current + 1, expected_errno);
159 		}
160 }
161 
162 static char *pathncat(char *buffer, size_t size, const char *path1, const char *path2)
163 {
164 	size_t len1, len2, lenslash;
165 
166 	assert(buffer);
167 	assert(path1);
168 	assert(path2);
169 
170 	/* check whether it fits */
171 	len1 = strlen(path1);
172 	len2 = strlen(path2);
173 	lenslash = (len1 > 0 && path1[len1 - 1] == '/') ? 0 : 1;
174 	if (len1 >= size || /* check individual components to avoid overflow */
175 		len2 >= size ||
176 		len1 + len2 + lenslash >= size)
177 		return NULL;
178 
179 	/* perform the copy */
180 	memcpy(buffer, path1, len1);
181 	if (lenslash)
182 		buffer[len1] = '/';
183 
184 	memcpy(buffer + len1 + lenslash, path2, len2 + 1);
185 	return buffer;
186 }
187 
188 static void check_realpath_recurse(const char *path, int depth)
189 {
190 	DIR *dir;
191 	struct dirent *dirent;
192 	char pathsub[PATH_MAX + 1];
193 	struct stat st;
194 
195 	/* check with the path itself */
196 	check_realpath_step_by_step(path, 0);
197 
198 	/* don't go too deep */
199 	if (depth < 1)
200 		return;
201 
202 	/* don't bother with non-directories. Due to timeouts in drivers we
203 	 * might not get expected results and takes way too long */
204 	if (stat(path, &st) != 0) {
205 		/* dangling symlinks may cause legitimate failures here */
206 		if (lstat(path, &st) != 0) ERR;
207 		return;
208 	}
209 	if (!S_ISDIR(st.st_mode))
210 		return;
211 
212 	/* loop through subdirectories (including . and ..) */
213 	if (!(dir = opendir(path)))
214 	{
215 		/* Opening some special files might result in errors when the
216 		 * corresponding hardware is not present, or simply when access
217 		 * rights prohibit access (e.g., /dev/log).
218 		 */
219 		if (errno != ENOTDIR
220 		    && errno != ENXIO && errno != EIO && errno != EACCES) {
221 			ERR;
222 		}
223 		return;
224 	}
225 	while ((dirent = readdir(dir)) != NULL)
226 	{
227 		/* build path */
228 		if (!pathncat(pathsub, sizeof(pathsub), path, dirent->d_name))
229 		{
230 			ERR;
231 			continue;
232 		}
233 
234 		/* check path */
235 		check_realpath_recurse(pathsub, depth - 1);
236 	}
237 	if (closedir(dir) < 0) ERR;
238 }
239 
240 #define PATH_DEPTH 4
241 #define PATH_BASE "/."
242 #define L(x) PATH_BASE "/link_" #x ".tmp"
243 
244 static char basepath[PATH_MAX + 1];
245 
246 static char *addbasepath(char *buffer, const char *path)
247 {
248 	size_t basepathlen, pathlen;
249 
250 	/* assumption: both start with slash and neither end with it */
251 	assert(basepath[0] == '/');
252 	assert(basepath[strlen(basepath) - 1] != '/');
253 	assert(buffer);
254 	assert(path);
255 	assert(path[0] == '/');
256 
257 	/* check result length */
258 	basepathlen = strlen(basepath);
259 	pathlen = strlen(path);
260 	if (basepathlen + pathlen > PATH_MAX)
261 	{
262 		printf("path too long\n");
263 		exit(-1);
264 	}
265 
266 	/* concatenate base path and path */
267 	memcpy(buffer, basepath, basepathlen);
268 	memcpy(buffer + basepathlen, path, pathlen + 1);
269 	return buffer;
270 }
271 
272 static void test_dirname(const char *path, const char *exp)
273 {
274 	char buffer[PATH_MAX];
275 	int i, j;
276 	size_t pathlen = strlen(path);
277 	char *pathout;
278 
279 	assert(pathlen + 3 < PATH_MAX);
280 
281 	/* try with no, one or two trailing slashes */
282 	for (i = 0; i < 3; i++)
283 	{
284 		/* no trailing slashes for empty string */
285 		if (pathlen < 1 && i > 0)
286 			continue;
287 
288 		/* prepare buffer */
289 		strcpy(buffer, path);
290 		for (j = 0; j < i; j++)
291 			buffer[pathlen + j] = '/';
292 
293 		buffer[pathlen + i] = 0;
294 
295 		/* perform test */
296 		pathout = dirname(buffer);
297 		if (strcmp(pathout, exp) != 0)
298 			ERR;
299 	}
300 }
301 
302 int main(int argc, char **argv)
303 {
304 	char buffer1[PATH_MAX + 1], buffer2[PATH_MAX + 1];
305 	subtest = 1;
306 
307 	/* initialize */
308 	start(43);
309 	executable = argv[0];
310 	getcwd(basepath, sizeof(basepath));
311 
312 	/* prepare some symlinks to make it more difficult */
313 	if (symlink("/",      addbasepath(buffer1, L(1))) < 0) ERR;
314 	if (symlink(basepath, addbasepath(buffer1, L(2))) < 0) ERR;
315 
316 	/* perform some tests */
317 	check_realpath_recurse(basepath, PATH_DEPTH);
318 
319 	/* now try with recursive symlinks */
320 	if (symlink(addbasepath(buffer1, L(3)), addbasepath(buffer2, L(3))) < 0) ERR;
321 	if (symlink(addbasepath(buffer1, L(5)), addbasepath(buffer2, L(4))) < 0) ERR;
322 	if (symlink(addbasepath(buffer1, L(4)), addbasepath(buffer2, L(5))) < 0) ERR;
323 	check_realpath_step_by_step(addbasepath(buffer1, L(3)), ELOOP);
324 	check_realpath_step_by_step(addbasepath(buffer1, L(4)), ELOOP);
325 	check_realpath_step_by_step(addbasepath(buffer1, L(5)), ELOOP);
326 
327 	/* delete the symlinks */
328 	cleanup();
329 
330 	/* also test dirname */
331 	test_dirname("", ".");
332 	test_dirname(".", ".");
333 	test_dirname("..", ".");
334 	test_dirname("x", ".");
335 	test_dirname("xy", ".");
336 	test_dirname("x/y", "x");
337 	test_dirname("xy/z", "xy");
338 	test_dirname("x/yz", "x");
339 	test_dirname("ab/cd", "ab");
340 	test_dirname("x//y", "x");
341 	test_dirname("xy//z", "xy");
342 	test_dirname("x//yz", "x");
343 	test_dirname("ab//cd", "ab");
344 	test_dirname("/", "/");
345 	test_dirname("/x", "/");
346 	test_dirname("/xy", "/");
347 	test_dirname("/x/y", "/x");
348 	test_dirname("/xy/z", "/xy");
349 	test_dirname("/x/yz", "/x");
350 	test_dirname("/ab/cd", "/ab");
351 	test_dirname("/x//y", "/x");
352 	test_dirname("/xy//z", "/xy");
353 	test_dirname("/x//yz", "/x");
354 	test_dirname("/ab//cd", "/ab");
355 	test_dirname("/usr/src", "/usr");
356 	test_dirname("/usr/src/test", "/usr/src");
357 	test_dirname("usr/src", "usr");
358 	test_dirname("usr/src/test", "usr/src");
359 
360 	/* done */
361 	quit();
362 	return(-1);	/* impossible */
363 }
364