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#include <support/xunistd.h>
12
13static void prepare (void);
14#define PREPARE(argc, argv) prepare ()
15
16static int do_test (void);
17#define TEST_FUNCTION do_test ()
18
19#include "../test-skeleton.c"
20
21static int dir_fd;
22
23static void
24prepare (void)
25{
26 size_t test_dir_len = strlen (test_dir);
27 static const char dir_name[] = "/tst-fchmodat.XXXXXX";
28
29 size_t dirbuflen = test_dir_len + sizeof (dir_name);
30 char *dirbuf = malloc (size: dirbuflen);
31 if (dirbuf == NULL)
32 {
33 puts (s: "out of memory");
34 exit (1);
35 }
36
37 snprintf (s: dirbuf, maxlen: dirbuflen, format: "%s%s", test_dir, dir_name);
38 if (mkdtemp (template: dirbuf) == NULL)
39 {
40 puts (s: "cannot create temporary directory");
41 exit (1);
42 }
43
44 add_temp_file (name: dirbuf);
45
46 dir_fd = open (file: dirbuf, O_RDONLY | O_DIRECTORY);
47 if (dir_fd == -1)
48 {
49 puts (s: "cannot open directory");
50 exit (1);
51 }
52}
53
54
55static int
56do_test (void)
57{
58 /* fdopendir takes over the descriptor, make a copy. */
59 int dupfd = dup (fd: dir_fd);
60 if (dupfd == -1)
61 {
62 puts (s: "dup failed");
63 return 1;
64 }
65 if (lseek (fd: dupfd, offset: 0, SEEK_SET) != 0)
66 {
67 puts (s: "1st lseek failed");
68 return 1;
69 }
70
71 /* The directory should be empty save the . and .. files. */
72 DIR *dir = fdopendir (fd: dupfd);
73 if (dir == NULL)
74 {
75 puts (s: "fdopendir failed");
76 return 1;
77 }
78 struct dirent64 *d;
79 while ((d = readdir64 (dirp: dir)) != NULL)
80 if (strcmp (d->d_name, ".") != 0 && strcmp (d->d_name, "..") != 0)
81 {
82 printf (format: "temp directory contains file \"%s\"\n", d->d_name);
83 return 1;
84 }
85 closedir (dirp: dir);
86
87 umask (mask: 022);
88
89 /* Try to create a file. */
90 int fd = openat (fd: dir_fd, file: "some-file", O_CREAT|O_RDWR|O_EXCL, 0666);
91 if (fd == -1)
92 {
93 if (errno == ENOSYS)
94 {
95 puts (s: "*at functions not supported");
96 return 0;
97 }
98
99 puts (s: "file creation failed");
100 return 1;
101 }
102 xwrite (fd, "hello", 5);
103 puts (s: "file created");
104
105 struct stat64 st1;
106 if (fstat64 (fd: fd, buf: &st1) != 0)
107 {
108 puts (s: "fstat64 failed");
109 return 1;
110 }
111
112 /* Before closing the file, try using this file descriptor to open
113 another file. This must fail. */
114 if (fchmodat (fd, "some-file", 0400, 0) != -1)
115 {
116 puts (s: "fchmodat using descriptor for normal file worked");
117 return 1;
118 }
119 if (errno != ENOTDIR)
120 {
121 puts (s: "\
122error for fchmodat using descriptor for normal file not ENOTDIR ");
123 return 1;
124 }
125
126 close (fd: fd);
127
128 if ((st1.st_mode & 0777) != 0644)
129 {
130 printf (format: "openat created mode %04o, not 0644\n", (st1.st_mode & 0777));
131 return 1;
132 }
133
134 if (fchmodat (dir_fd, "some-file", 0400, 0) != 0)
135 {
136 puts (s: "fchownat failed");
137 return 1;
138 }
139
140 struct stat64 st2;
141 if (fstatat64 (fd: dir_fd, file: "some-file", buf: &st2, flag: 0) != 0)
142 {
143 puts (s: "fstatat64 failed");
144 return 1;
145 }
146
147 if ((st2.st_mode & 0777) != 0400)
148 {
149 puts (s: "mode change failed");
150 return 1;
151 }
152
153 if (unlinkat (fd: dir_fd, name: "some-file", flag: 0) != 0)
154 {
155 puts (s: "unlinkat failed");
156 return 1;
157 }
158
159 /* Create a file descriptor which is closed again right away. */
160 int dir_fd2 = dup (fd: dir_fd);
161 if (dir_fd2 == -1)
162 {
163 puts (s: "dup failed");
164 return 1;
165 }
166 close (fd: dir_fd2);
167
168 if (fchmodat (dir_fd2, "some-file", 0400, 0) != -1)
169 {
170 puts (s: "fchmodat using closed descriptor worked");
171 return 1;
172 }
173 if (errno != EBADF)
174 {
175 puts (s: "error for fchmodat using closed descriptor not EBADF ");
176 return 1;
177 }
178
179 close (fd: dir_fd);
180
181 if (fchmodat (-1, "some-file", 0400, 0) != -1)
182 {
183 puts (s: "fchmodat using invalid descriptor worked");
184 return 1;
185 }
186 if (errno != EBADF)
187 {
188 puts (s: "error for fchmodat using invalid descriptor not EBADF ");
189 return 1;
190 }
191
192 return 0;
193}
194

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