1/* Test for fchmodat function. */
2
3#include <dirent.h>
4#include <fcntl.h>
5#include <stdio.h>
6#include <stdlib.h>
7#include <string.h>
8#include <unistd.h>
9#include <sys/stat.h>
10
11
12static void prepare (void);
13#define PREPARE(argc, argv) prepare ()
14
15static int do_test (void);
16#define TEST_FUNCTION do_test ()
17
18#include "../test-skeleton.c"
19
20static int dir_fd;
21
22static void
23prepare (void)
24{
25 size_t test_dir_len = strlen (test_dir);
26 static const char dir_name[] = "/tst-fchmodat.XXXXXX";
27
28 size_t dirbuflen = test_dir_len + sizeof (dir_name);
29 char *dirbuf = malloc (size: dirbuflen);
30 if (dirbuf == NULL)
31 {
32 puts (s: "out of memory");
33 exit (1);
34 }
35
36 snprintf (s: dirbuf, maxlen: dirbuflen, format: "%s%s", test_dir, dir_name);
37 if (mkdtemp (template: dirbuf) == NULL)
38 {
39 puts (s: "cannot create temporary directory");
40 exit (1);
41 }
42
43 add_temp_file (name: dirbuf);
44
45 dir_fd = open (file: dirbuf, O_RDONLY | O_DIRECTORY);
46 if (dir_fd == -1)
47 {
48 puts (s: "cannot open directory");
49 exit (1);
50 }
51}
52
53
54static int
55do_test (void)
56{
57 /* fdopendir takes over the descriptor, make a copy. */
58 int dupfd = dup (fd: dir_fd);
59 if (dupfd == -1)
60 {
61 puts (s: "dup failed");
62 return 1;
63 }
64 if (lseek (fd: dupfd, offset: 0, SEEK_SET) != 0)
65 {
66 puts (s: "1st lseek failed");
67 return 1;
68 }
69
70 /* The directory should be empty save the . and .. files. */
71 DIR *dir = fdopendir (fd: dupfd);
72 if (dir == NULL)
73 {
74 puts (s: "fdopendir failed");
75 return 1;
76 }
77 struct dirent64 *d;
78 while ((d = readdir64 (dirp: dir)) != NULL)
79 if (strcmp (d->d_name, ".") != 0 && strcmp (d->d_name, "..") != 0)
80 {
81 printf (format: "temp directory contains file \"%s\"\n", d->d_name);
82 return 1;
83 }
84 closedir (dirp: dir);
85
86 umask (mask: 022);
87
88 /* Try to create a file. */
89 int fd = openat (fd: dir_fd, file: "some-file", O_CREAT|O_RDWR|O_EXCL, 0666);
90 if (fd == -1)
91 {
92 if (errno == ENOSYS)
93 {
94 puts (s: "*at functions not supported");
95 return 0;
96 }
97
98 puts (s: "file creation failed");
99 return 1;
100 }
101 write (fd, "hello", 5);
102 puts (s: "file created");
103
104 struct stat64 st1;
105 if (fstat64 (fd: fd, buf: &st1) != 0)
106 {
107 puts (s: "fstat64 failed");
108 return 1;
109 }
110
111 /* Before closing the file, try using this file descriptor to open
112 another file. This must fail. */
113 if (fchmodat (fd, "some-file", 0400, 0) != -1)
114 {
115 puts (s: "fchmodat using descriptor for normal file worked");
116 return 1;
117 }
118 if (errno != ENOTDIR)
119 {
120 puts (s: "\
121error for fchmodat using descriptor for normal file not ENOTDIR ");
122 return 1;
123 }
124
125 close (fd: fd);
126
127 if ((st1.st_mode & 0777) != 0644)
128 {
129 printf (format: "openat created mode %04o, not 0644\n", (st1.st_mode & 0777));
130 return 1;
131 }
132
133 if (fchmodat (dir_fd, "some-file", 0400, 0) != 0)
134 {
135 puts (s: "fchownat failed");
136 return 1;
137 }
138
139 struct stat64 st2;
140 if (fstatat64 (fd: dir_fd, file: "some-file", buf: &st2, flag: 0) != 0)
141 {
142 puts (s: "fstatat64 failed");
143 return 1;
144 }
145
146 if ((st2.st_mode & 0777) != 0400)
147 {
148 puts (s: "mode change failed");
149 return 1;
150 }
151
152 if (unlinkat (fd: dir_fd, name: "some-file", flag: 0) != 0)
153 {
154 puts (s: "unlinkat failed");
155 return 1;
156 }
157
158 /* Create a file descriptor which is closed again right away. */
159 int dir_fd2 = dup (fd: dir_fd);
160 if (dir_fd2 == -1)
161 {
162 puts (s: "dup failed");
163 return 1;
164 }
165 close (fd: dir_fd2);
166
167 if (fchmodat (dir_fd2, "some-file", 0400, 0) != -1)
168 {
169 puts (s: "fchmodat using closed descriptor worked");
170 return 1;
171 }
172 if (errno != EBADF)
173 {
174 puts (s: "error for fchmodat using closed descriptor not EBADF ");
175 return 1;
176 }
177
178 close (fd: dir_fd);
179
180 if (fchmodat (-1, "some-file", 0400, 0) != -1)
181 {
182 puts (s: "fchmodat using invalid descriptor worked");
183 return 1;
184 }
185 if (errno != EBADF)
186 {
187 puts (s: "error for fchmodat using invalid descriptor not EBADF ");
188 return 1;
189 }
190
191 return 0;
192}
193

source code of glibc/io/tst-fchmodat.c